Science.gov

Sample records for receptor m33 occurs

  1. The M33 G Protein-Coupled Receptor Encoded by Murine Cytomegalovirus Is Dispensable for Hematogenous Dissemination but Is Required for Growth within the Salivary Gland

    PubMed Central

    Bittencourt, Fabiola M.; Wu, Shu-En; Bridges, James P.

    2014-01-01

    ABSTRACT Human cytomegalovirus (HCMV) is a pathogen found worldwide and is a serious threat to immunocompromised individuals and developing fetuses. Due to the species specificity of cytomegaloviruses, murine cytomegalovirus (MCMV) has been used as a model for in vivo studies of HCMV pathogenesis. The MCMV genome, like the genomes of other beta- and gammaherpesviruses, encodes G protein-coupled receptors (GPCRs) that modulate host signaling pathways presumably to facilitate viral replication and dissemination. Among these viral receptors, the M33 GPCR carried by MCMV is an activator of CREB, NF-κB, and phospholipase C-β signaling pathways and has been implicated in aspects of pathogenesis in vivo, including persistence in the salivary glands of BALB/c mice. In this study, we used immunocompetent nonobese diabetic (NOD) and immunocompromised NOD-scid-gamma (NSG) mice to further investigate the salivary gland defect exhibited by M33 deficiency. Interestingly, we demonstrate that virus with an M33 deletion (ΔM33) can replicate in the salivary gland of immunocompromised animals, albeit with a 400-fold growth defect compared with the growth of wild-type virus. Moreover, we determined that M33 does not have a role in cell-associated hematogenous dissemination but is required for viral amplification once the virus reaches the salivary gland. We conclude that the reduced replicative capacity of the ΔM33 virus is due to a specific defect occurring within the localized environment of the salivary gland. Importantly, since the salivary gland represents a site essential for persistence and horizontal transmission, an understanding of the mechanisms of viral replication within this site could lead to the generation of novel therapeutics useful for the prevention of HCMV spread. IMPORTANCE Human cytomegalovirus infects the majority of the American people and can reside silently in infected individuals for the duration of their lives. Under a number of circumstances, the

  2. The M33 Chemokine Receptor Homolog of Murine Cytomegalovirus Exhibits a Differential Tissue-Specific Role during In Vivo Replication and Latency▿

    PubMed Central

    Cardin, Rhonda D.; Schaefer, Gregory C.; Allen, Janelle R.; Davis-Poynter, Nicholas J.; Farrell, Helen E.

    2009-01-01

    M33, encoded by murine cytomegalovirus (MCMV), is a member of the UL33 homolog G-protein-coupled receptor (GPCR) family and is conserved across all the betaherpesviruses. Infection of mice with recombinant viruses lacking M33 or containing specific signaling domain mutations in M33 results in significantly diminished MCMV infection of the salivary glands. To determine the role of M33 in viral dissemination and/or infection in other tissues, viral infection with wild-type K181 virus and an M33 mutant virus, ΔM33BT2, was characterized using two different routes of inoculation. Following both intraperitoneal (i.p.) and intranasal (i.n.) inoculation, M33 was attenuated for infection of the spleen and pancreas as early as 7 days after infection. Following i.p. inoculation, ΔM33BT2 exhibited a severe defect in latency as measured by a diminished capacity to reactivate from spleens and lungs in reactivation assays (P < 0.001). Subsequent PCR analysis revealed markedly reduced ΔM33BT2 viral DNA levels in the latently infected spleens, lungs, and bone marrow. Following i.n. inoculation, latent ΔM33BT2 viral DNA was significantly reduced in the spleen and, in agreement with results from i.p. inoculation, did not reactivate from the spleen (P < 0.001). Furthermore, in vivo complementation of ΔM33BT2 virus replication and/or dissemination to the salivary glands and pancreas was achieved by coinfection with wild-type virus. Overall, our data suggest a critical tissue-specific role for M33 during infection in the salivary glands, spleen, and pancreas but not the lungs. Our data suggest that M33 contributes to the efficient establishment or maintenance of long-term latent MCMV infection. PMID:19439478

  3. Dense gas in M 33 (HerM33es)

    NASA Astrophysics Data System (ADS)

    Buchbender, C.; Kramer, C.; Gonzalez-Garcia, M.; Israel, F. P.; García-Burillo, S.; van der Werf, P.; Braine, J.; Rosolowsky, E.; Mookerjea, B.; Aalto, S.; Boquien, M.; Gratier, P.; Henkel, C.; Quintana-Lacaci, G.; Verley, S.; van der Tak, F.

    2013-01-01

    Aims: We aim to better understand the emission of molecular tracers of the diffuse and dense gas in giant molecular clouds and the influence that metallicity, optical extinction, density, far-UV field, and star formation rate have on these tracers. Methods: Using the IRAM 30 m telescope, we detected HCN, HCO+, 12CO, and 13CO in six GMCs along the major axis of M 33 at a resolution of ~114 pc and out to a radial distance of 3.4 kpc. Optical, far-infrared, and submillimeter data from Herschel and other observatories complement these observations. To interpret the observed molecular line emission, we created two grids of models of photon-dominated regions, one for solar and one for M 33-type subsolar metallicity. Results: The observed HCO+/HCN line ratios range between 1.1 and 2.5. Similarly high ratios have been observed in the Large Magellanic Cloud. The HCN/CO ratio varies between 0.4% and 2.9% in the disk of M 33. The 12CO/13CO line ratio varies between 9 and 15 similar to variations found in the diffuse gas and the centers of GMCs of the Milky Way. Stacking of all spectra allowed HNC and C2H to be detected. The resulting HCO+/HNC and HCN/HNC ratios of ~8 and 6, respectively, lie at the high end of ratios observed in a large set of (ultra-)luminous infrared galaxies. HCN abundances are lower in the subsolar metallicity PDR models, while HCO+ abundances are enhanced. For HCN this effect is more pronounced at low optical extinctions. The observed HCO+/HCN and HCN/CO line ratios are naturally explained by subsolar PDR models of low optical extinctions between 4 and 10 mag and of moderate densities of n 3 × 103-3 × 104 cm-3, while the FUV field strength only has a small effect on the modeled line ratios. The line ratios are almost equally well reproduced by the solar-metallicity models, indicating that variations in metallicity only play a minor role in influencing these line ratios. Based on observations with the IRAM 30m telescope, Herschel, and other

  4. Chemical Evolution Model of M33

    NASA Astrophysics Data System (ADS)

    Robles-Valdez, F.; Carigi, L.

    2011-10-01

    We present a chemical evolution model (CEM) of M33 and we find that M33, which is smaller than both M31 and MW, shows a lower gas infall rate, SFR efficiency, and IMF M_{up}. Therefore the CEMs for large spiral galaxies (Carigi et al. 2005; Meneses-Goytia et al. 2011) can be scaled to a smaller galaxy.

  5. SQIID Imaging of the M 33 Core

    NASA Astrophysics Data System (ADS)

    Polomski, E.; Gehrz, R. D.; Humphreys, R.; Woodward, C. E.; Jones, T. J.; Lyke, J.; Eicher, K.; Willner, S.; Barmby, P.; Huchra, J.; Strom, S.

    2001-05-01

    We have initiated a program of high spatial resolution infrared mapping of M 33 as part of a study of the stellar populations of nearby spiral galaxies. M 33 is one of the two nearest spiral galaxies, and is oriented nearly face-on, providing a unique opportunity for a comprehensive survey of its population. Large scale surveys in the infrared can penetrate the interstellar obscuration in M 33 and give a more complete assessment of the various stellar components than optical observations. Near-IR colors can also distinguish between different evolutionary classes, such as pre-main sequence stars, red supergiants, Asymptotic Giant Branch stars, and main sequence objects. We present here the first results of this program; near-IR J, H, and K band maps of M 33, obtained with the SQIID imager at KPNO. We focus on the core, ~5x5', region of M 33, and show near-IR colors for the sources in this region, as well as the central engine. Our maps complement those from the 2MASS survey, but go 5 magnitudes deeper (K ~ 20) and achieve better spatial resolution (FWHM < 2" ). These maps will provide the foundation for upcoming SIRTF observations which will involve temporal studies of the same region in the mid and far-IR. The reduced data from our JHK survey will be placed in a publicly available database when the project is complete.

  6. Gas and Dust in M33

    NASA Astrophysics Data System (ADS)

    Braine, J.; Gratier, P.; Kramer, C.; Mookerjea, B.; Xilouris, M.; Calzetti, D.

    2011-12-01

    We present results from the Herschel and IRAM projects to map M33 in the dust continuum and main emission lines, particularly C[II] and CO. The temperature of the cool dust decreases with distance from the center of M33 from ~25K to ~13K. The CO emission generally follows the dust temperature and the overall dust emission. However, about 1/6 of the molecular clouds are not associated with massive stars, such that about 1/6th the lifetime of an entity identifiable as a molecular cloud is in a pre-star formation state. These clouds are less CO-bright than those with massive stars. The largest sample of molecular clouds currently available for an external galaxy shows that the cloud CO luminosity function, usually viewed as the cloud H2 mass, steepens with radius such that smaller clouds are more numerous in the outer parts. The observations of the C[II] line with Herschel indicate that the C[II] emission traces on-going star formation rather than the neutral gas. This identification will be tested via velocity-resolved Herschel/HIFI C[II] spectra in the near future.

  7. BLENDING OF CEPHEIDS IN M33

    SciTech Connect

    Chavez, Joy M.; Macri, Lucas M.; Pellerin, Anne

    2012-10-01

    A precise and accurate determination of the Hubble constant based on Cepheid variables requires proper characterization of many sources of systematic error. One of these is stellar blending, which biases the measured fluxes of Cepheids and the resulting distance estimates. We study the blending of 149 Cepheid variables in M33 by matching archival Hubble Space Telescope data with images obtained at the Wisconsin-Indiana-Yale-NOAO (WIYN) 3.5 m telescope, which differ by a factor of 10 in angular resolution. We find that 55% {+-} 4% of the Cepheids have no detectable nearby companions that could bias the WIYN V-band photometry, while the fraction of Cepheids affected below the 10% level is 73% {+-} 4%. The corresponding values for the I band are 60% {+-} 4% and 72% {+-} 4%, respectively. We find no statistically significant difference in blending statistics as a function of period or surface brightness. Additionally, we report all the detected companions within 2'' of the Cepheids (equivalent to 9 pc at the distance of M33) which may be used to derive empirical blending corrections for Cepheids at larger distances.

  8. THE CHANDRA ACIS SURVEY OF M33 (ChASeM33): THE FINAL SOURCE CATALOG

    SciTech Connect

    Tuellmann, R.; Gaetz, T. J.; Plucinsky, P. P.; Challis, P.; Edgar, R. J.; Kirshner, R. P.; Kuntz, K. D.; Blair, W. P.; Williams, B. F.; Pietsch, W.; Haberl, F.; Long, K. S.; Sasaki, M.; Winkler, P. F.; Pannuti, T. G.; Helfand, D. J.; Hughes, J. P.; Mazeh, T.; Shporer, A.

    2011-04-01

    This study presents the final source catalog of the Chandra ACIS Survey of M33 (ChASeM33). With a total exposure time of 1.4 Ms, ChASeM33 covers {approx}70% of the D{sub 25} isophote (R {approx} 4.0 kpc) of M33 and provides the deepest, most complete, and detailed look at a spiral galaxy in X-rays. The source catalog includes 662 sources, reaches a limiting unabsorbed luminosity of {approx}2.4x10{sup 34} erg s{sup -1} in the 0.35-8.0 keV energy band, and contains source positions, source net counts, fluxes and significances in several energy bands, and information on source variability. The analysis challenges posed by ChASeM33 and the techniques adopted to address these challenges are discussed. To constrain the nature of the detected X-ray source, hardness ratios were constructed and spectra were fit for 254 sources, follow-up MMT spectra of 116 sources were acquired, and cross-correlations with previous X-ray catalogs and other multi-wavelength data were generated. Based on this effort, 183 of the 662 ChASeM33 sources could be identified. Finally, the luminosity function (LF) for the detected point sources as well as the one for the X-ray binaries (XRBs) in M33 is presented. The LFs in the soft band (0.5-2.0 keV) and the hard band (2.0-8.0 keV) have a limiting luminosity at the 90% completeness limit of 4.0 x 10{sup 34} erg s{sup -1} and 1.6 x 10{sup 35} erg s{sup -1}(for D = 817 kpc), respectively, which is significantly lower than what was reported by previous XRB population studies in galaxies more distant than M33. The resulting distribution is consistent with a dominant population of high-mass XRBs as would be expected for M33.

  9. No supermassive black hole in M33?

    PubMed

    Merritt, D; Ferrarese, L; Joseph, C L

    2001-08-10

    We observed the nucleus of M33, the third-brightest galaxy in the Local Group, with the Space Telescope Imaging Spectrograph at a resolution at least a factor of 10 higher than previously obtained. Rather than the steep rise expected within the radius of gravitational influence of a supermassive black hole, the random stellar velocities showed a decrease within a parsec of the center of the galaxy. The implied upper limit on the mass of the central black hole is only 3000 solar masses, about three orders of magnitude lower than the dynamically inferred mass of any other supermassive black hole. Detecting black holes of only a few thousand solar masses is observationally challenging, but it is critical to establish how supermassive black holes relate to their host galaxies, and which mechanisms influence the formation and evolution of both.

  10. Unbound molecular complexes in M33

    NASA Technical Reports Server (NTRS)

    Wilson, Christine D.

    1990-01-01

    The HI content of the nearby spiral galaxy M33 (d approx. 0.8 Mpc) has been the subject of many detailed studies (most recently Deul and van der Hulst 1987), but similar data on the molecular gas component has been lacking. This galaxy is currently undergoing vigorous high-mass star formation, as evidenced by the many OB associations and HII regions, and so is expected to possess at least some molecular gas. Interferometric studies have detected molecular clouds similar to Galactic Giant Molecular Clouds (GMCs) (Boulanger et al. 1988; Wilson et al. 1988). Researchers have recently mapped the nuclear region of M33 in the CO J=1-0 line with a 12 m telescope (half power beam width 55 inches approx. 210 pc) out to a radius of 3.5 minutes in order to trace the detailed distribution of the molecular gas. The resulting map reveals six large complexes with diameters of 200 to 400 pc. Interferometer observations of these regions have resolved them into individual molecular clouds similar to Galactic GMCs (Wilson et al. 1988). The complexes shown are much larger than individual Galactic GMCs (Sanders, Scoville, and Solomon 1985), but are somewhat smaller on average than the large associations seen in the grand-design spiral galaxy M51 (Rand and Kulkarni 1989). If we extend the velocity-diameter relation observed for Galactic GMCs to these larger structures, the predicted velocity widths are a factor of 1.5 to 3 times greater than the observed full-width half-maximum velocities (13 to 29 km (s-1). The peak brightness temperatures are approx. 0.2 K, at least a factor of 10 lower than what is observed for Galactic GMCs. If these large structures are made up of objects similar to Galactic GMCs, the area filling factor of the small clouds is roughly 10 percent. These results suggest that these complexes are not very large GMCs, but rather are associations of many individual GMCs or GMCs embedded in a diffuse gas component.

  11. Naturally occurring and synthetic peptides acting on nicotinic acetylcholine receptors.

    PubMed

    Kasheverov, Igor E; Utkin, Yuri N; Tsetlin, Victor I

    2009-01-01

    Nicotinic acetylcholine receptors (nAChRs) are pentameric membrane-bound proteins belonging to the large family of ligand-gated ion channels. nAChRs possess various binding sites which interact with compounds of different chemical nature, including peptides. Historically first peptides found to act on nAChR were synthetic fragments of snake alpha-neurotoxins, competitive receptor antagonists. Later it was shown that fragments of glycoprotein from rabies virus, having homology to alpha-neurotoxins, and polypeptide neurotoxins waglerins from the venom of Wagler's pit viper Trimeresurus (Tropidolaemus) wagleri bind in a similar way, waglerins being efficient blockers of muscle-type nAChRs. Neuropeptide substance P appears to interact with the channel moiety of nAChR. beta-Amyloid, a peptide forming senile plaques in Alzheimer's disease, also can bind to nAChR, although the mode of binding is still unclear. However, the most well-studied peptides interacting with the ligand-binding sites of nAChRs are so-called alpha-conotoxins, peptide neurotoxins from marine snails of Conus genus. First alpha-conotoxins were discovered in the late 1970s, and now it is a rapidly growing family due to isolation of peptides from multiple Conus species, as well as to cloning, and chemical synthesis of new analogues. Because of their unique selectivity towards distinct nAChR subtypes, alpha-conotoxins became valuable tools in nAChR research. Recent X-ray structures of alpha-conotoxin complexes with acetylcholine-binding protein, a model of nAChR ligand-binding domains, revealed the details of the nAChR ligand-binding sites and provided the basis for design of novel ligands.

  12. The molecular gas mass of M 33

    NASA Astrophysics Data System (ADS)

    Gratier, P.; Braine, J.; Schuster, K.; Rosolowsky, E.; Boquien, M.; Calzetti, D.; Combes, F.; Kramer, C.; Henkel, C.; Herpin, F.; Israel, F.; Koribalski, B. S.; Mookerjea, B.; Tabatabaei, F. S.; Röllig, M.; van der Tak, F. F. S.; van der Werf, P.; Wiedner, M.

    2017-03-01

    Do some environments favor efficient conversion of molecular gas into stars? To answer this, we need to be able to estimate the H2 mass. Traditionally, this is done using CO observations and a few assumptions but the Herschel observations which cover the far-IR dust spectrum make it possible to estimate the molecular gas mass independently of CO and thus to investigate whether and how the CO traces H2. Previous attempts to derive gas masses from dust emission suffered from biases. Generally, dust surface densities, H i column densities, and CO intensities are used to derive a gas-to-dust ratio (GDR) and the local CO intensity to H2 column density ratio (XCO), sometimes allowing for an additional CO-dark gas component (Kdark). We tested earlier methods, revealing degeneracies among the parameters, and then used a sophisticated Bayesian formalism to derive the most likely values for each of the parameters mentioned above as a function of position in the nearby prototypical low metallicity (12 + log (O/H) 8.4) spiral galaxy M 33. The data are from the IRAM Large Program mapping in the CO(2-1) line along with high-resolution H i and Herschel dust continuum observations. Solving for GDR, XCO, and Kdark in macropixels 500 pc in size, each containing many individual measurements of the CO, H i, and dust emission, we find that (i) allowing for CO dark gas (Kdark) significantly improves fits; (ii) Kdark decreases with galactocentric distance; (iii) GDR is slightly higher than initially expected and increases with galactocentric distance; (iv) the total amount of dark gas closely follows the radially decreasing CO emission, as might be expected if the dark gas is H2 where CO is photodissociated. The total amount of H2, including dark gas, yields an average XCO of twice the galactic value of 2 × 1020 cm-2/ K km s-1, with about 55% of this traced directly through CO. The rather constant fraction of dark gas suggests that there is no large population of diffuse H2 clouds

  13. Dust properties in H II regions in M 33

    NASA Astrophysics Data System (ADS)

    Relaño, M.; Kennicutt, R.; Lisenfeld, U.; Verley, S.; Hermelo, I.; Boquien, M.; Albrecht, M.; Kramer, C.; Braine, J.; Pérez-Montero, E.; De Looze, I.; Xilouris, M.; Kovács, A.; Staguhn, J.

    2016-10-01

    regions can lead to fragmentation of BGs into smaller ones, while the more evolved shell and clear shell objects provide a more quiescent environment where reformation of dust BGs might occur. The gas-to-dust variations found in this analysis might imply that grain coagulation and/or gas-phase metal incorporation into the dust mass is occurring in the interior of the H ii regions in M 33. Full Tables A.1 and A.2 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/595/A43

  14. The M33 Synoptic Stellar Survey. II. Mira Variables

    NASA Astrophysics Data System (ADS)

    Yuan, Wenlong; He, Shiyuan; Macri, Lucas M.; Long, James; Huang, Jianhua Z.

    2017-04-01

    We present the discovery of 1847 Mira candidates in the Local Group galaxy M33 using a novel semi-parametric periodogram technique coupled with a random forest classifier. The algorithms were applied to ∼2.4 × 105 I-band light curves previously obtained by the M33 Synoptic Stellar Survey. We derive preliminary period–luminosity relations at optical, near-infrared, and mid-infrared wavelengths and compare them to the corresponding relations in the Large Magellanic Cloud.

  15. PROBING THE M33 HALO USING RR LYRAE STARS

    SciTech Connect

    Pritzl, Barton J.; Olszewski, Edward W.; Saha, Abhijit; Venn, Kim A.; Skillman, Evan D. E-mail: eolszewski@as.arizona.edu E-mail: kvenn@uvic.ca

    2011-12-15

    We present the discovery of RR Lyrae (RRL) variable stars in two fields of M33 to the southeast of its center using Gemini North observations. In the outermost field (45' to the southeast of the M33 center; projected distance of 10.8 kpc; deprojected distance of about 19 kpc; about 5 V-band disk scale lengths) we detected two RRLs, consisting of one RRab star and one RRc star. An additional variable was found in this field that is a possible Cepheid. The mean g'-band magnitude for the two RRL stars is 25.60 {+-} 0.04 mag. In the other field (25' to the southeast of the M33 center; projected distance of 5.6 kpc; deprojected distance of about 10 kpc; about 3 V-band disk scale lengths) we found 12 RRL stars, all of which are RRab stars. We also detected two candidate Cepheid variables in this field. The mean magnitude for the RRL stars in this field is 25.64 {+-} 0.14 mag. We found a distance modulus of ((m - M){sub 0}) = 24.69 {+-} 0.17 mag from the RRab stars in the field 25' from M33. The mean periods of the RRab stars in both fields (0.630 {+-} 0.002 days, 45' southeast; 0.628 {+-} 0.055 days, 25' southeast) are much longer than found for previously detected RRL stars in the inner regions of M33. This finding argues for a low metallicity for the RRab stars in the field 25' from M33 ([Fe/H] =-1.84 {+-} 0.30 dex). Given these properties, we conclude that the RRLs we have detected belong to the halo of M33 and thus that there is an old component in the outer regions of M33.

  16. Primary Macrophage Chemotaxis Induced by Cannabinoid Receptor 2 Agonists Occurs Independently of the CB2 Receptor

    PubMed Central

    Taylor, Lewis; Christou, Ivy; Kapellos, Theodore S.; Buchan, Alice; Brodermann, Maximillian H.; Gianella-Borradori, Matteo; Russell, Angela; Iqbal, Asif J.; Greaves, David R.

    2015-01-01

    Activation of CB2 has been demonstrated to induce directed immune cell migration. However, the ability of CB2 to act as a chemoattractant receptor in macrophages remains largely unexplored. Using a real-time chemotaxis assay and a panel of chemically diverse and widely used CB2 agonists, we set out to examine whether CB2 modulates primary murine macrophage chemotaxis. We report that of 12 agonists tested, only JWH133, HU308, L-759,656 and L-759,633 acted as macrophage chemoattractants. Surprisingly, neither pharmacological inhibition nor genetic ablation of CB2 had any effect on CB2 agonist-induced macrophage chemotaxis. As chemotaxis was pertussis toxin sensitive in both WT and CB2-/- macrophages, we concluded that a non-CB1/CB2, Gi/o-coupled GPCR must be responsible for CB2 agonist-induced macrophage migration. The obvious candidate receptors GPR18 and GPR55 could not mediate JWH133 or HU308-induced cytoskeletal rearrangement or JWH133-induced β-arrestin recruitment in cells transfected with either receptor, demonstrating that neither are the unidentified GPCR. Taken together our results conclusively demonstrate that CB2 is not a chemoattractant receptor for murine macrophages. Furthermore we show for the first time that JWH133, HU308, L-759,656 and L-759,633 have off-target effects of functional consequence in primary cells and we believe that our findings have wide ranging implications for the entire cannabinoid field. PMID:26033291

  17. Primary Macrophage Chemotaxis Induced by Cannabinoid Receptor 2 Agonists Occurs Independently of the CB2 Receptor.

    PubMed

    Taylor, Lewis; Christou, Ivy; Kapellos, Theodore S; Buchan, Alice; Brodermann, Maximillian H; Gianella-Borradori, Matteo; Russell, Angela; Iqbal, Asif J; Greaves, David R

    2015-06-02

    Activation of CB2 has been demonstrated to induce directed immune cell migration. However, the ability of CB2 to act as a chemoattractant receptor in macrophages remains largely unexplored. Using a real-time chemotaxis assay and a panel of chemically diverse and widely used CB2 agonists, we set out to examine whether CB2 modulates primary murine macrophage chemotaxis. We report that of 12 agonists tested, only JWH133, HU308, L-759,656 and L-759,633 acted as macrophage chemoattractants. Surprisingly, neither pharmacological inhibition nor genetic ablation of CB2 had any effect on CB2 agonist-induced macrophage chemotaxis. As chemotaxis was pertussis toxin sensitive in both WT and CB2(-/-) macrophages, we concluded that a non-CB1/CB2, Gi/o-coupled GPCR must be responsible for CB2 agonist-induced macrophage migration. The obvious candidate receptors GPR18 and GPR55 could not mediate JWH133 or HU308-induced cytoskeletal rearrangement or JWH133-induced β-arrestin recruitment in cells transfected with either receptor, demonstrating that neither are the unidentified GPCR. Taken together our results conclusively demonstrate that CB2 is not a chemoattractant receptor for murine macrophages. Furthermore we show for the first time that JWH133, HU308, L-759,656 and L-759,633 have off-target effects of functional consequence in primary cells and we believe that our findings have wide ranging implications for the entire cannabinoid field.

  18. The Structure of Halo Gas around M33

    NASA Astrophysics Data System (ADS)

    Keenan, Olivia C.; Davies, Jonathan I.; Taylor, Rhys; Minchin, Robert F.

    2017-03-01

    Understanding the distribution of gas in and around galaxies is vital for our interpretation of galaxy formation and evolution. As part of the Arecibo Galaxy Environment Survey (AGES) we have observed the neutral hydrogen (HI) gas in and around the nearby Local Group galaxy M33 to a greater depth than previous observations. As part of this project we investigated the absence of optically detected dwarf galaxies in its neighbourhood, which is contrary to predictions of galaxy formation models. We observed 22 discrete clouds, 11 of which were previously undetected and none of which have optically detected counterparts. We find one particularly interesting hydrogen cloud, which has many similar characteristics to hydrogen distributed in the disk of a galaxy. This cloud, if it is at the distance of M33, has a HI mass of around 107 M⊙ and a diameter of 18 kpc, making it larger in size than M33 itself.

  19. THE PHOTOMETRIC PROPERTIES OF A VAST STELLAR SUBSTRUCTURE IN THE OUTSKIRTS OF M33

    SciTech Connect

    McConnachie, Alan W.; Ferguson, Annette M. N.; Irwin, Michael J.; Dubinski, John; Widrow, Lawrence M.; Dotter, Aaron; Ibata, Rodrigo; Lewis, Geraint F.

    2010-11-10

    We have surveyed approximately 40 deg{sup 2} surrounding M33 with Canada-France-Hawaii Telescope MegaCam/MegaPrime in the g and i filters out to a maximum projected radius from this galaxy of 50 kpc, as part of the Pan-Andromeda Archaeological Survey (PAndAS). Our observations are deep enough to resolve the top {approx}4 mag of the red giant branch population in this galaxy. We have previously shown that the disk of M33 is surrounded by a large, irregular, low surface brightness substructure. Here, we quantify the stellar populations and structure of this feature using the PAndAS data. We show that the stellar populations of this feature are consistent with an old population with ([Fe/H]) {approx} -1.6 dex and an interquartile range in metallicity of {approx}0.5 dex. We construct a surface brightness map of M33 that traces this feature to {mu}{sub V} {approx_equal} 33 mag arcsec{sup -2}. At these low surface brightness levels, the structure extends to projected radii of {approx}40 kpc from the center of M33 in both the northwest and southeast quadrants of the galaxy. Overall, the structure has an 'S-shaped' appearance that broadly aligns with the orientation of the H I disk warp. We calculate a lower limit to the integrated luminosity of the structure of -12.7 {+-} 0.5 mag, comparable to a bright dwarf galaxy such as Fornax or Andromeda II and slightly less than 1% of the total luminosity of M33. Further, we show that there is tentative evidence for a distortion in the distribution of young stars near the edge of the H I disk that occurs at similar azimuth to the warp in H I. The data also hint at a low-level, extended stellar component at larger radius that may be an M33 halo component. We revisit studies of M33 and its stellar populations in light of these new results and discuss possible formation scenarios for the vast stellar structure. Our favored model is that of the tidal disruption of M33 in its orbit around M31.

  20. The Photometric Properties of a Vast Stellar Substructure in the Outskirts of M33

    NASA Astrophysics Data System (ADS)

    McConnachie, Alan W.; Ferguson, Annette M. N.; Irwin, Michael J.; Dubinski, John; Widrow, Lawrence M.; Dotter, Aaron; Ibata, Rodrigo; Lewis, Geraint F.

    2010-11-01

    We have surveyed approximately 40 deg2 surrounding M33 with Canada-France-Hawaii Telescope MegaCam/MegaPrime in the g and i filters out to a maximum projected radius from this galaxy of 50 kpc, as part of the Pan-Andromeda Archaeological Survey (PAndAS). Our observations are deep enough to resolve the top ~4 mag of the red giant branch population in this galaxy. We have previously shown that the disk of M33 is surrounded by a large, irregular, low surface brightness substructure. Here, we quantify the stellar populations and structure of this feature using the PAndAS data. We show that the stellar populations of this feature are consistent with an old population with lang[Fe/H]rang ~ -1.6 dex and an interquartile range in metallicity of ~0.5 dex. We construct a surface brightness map of M33 that traces this feature to μ V ~= 33 mag arcsec-2. At these low surface brightness levels, the structure extends to projected radii of ~40 kpc from the center of M33 in both the northwest and southeast quadrants of the galaxy. Overall, the structure has an "S-shaped" appearance that broadly aligns with the orientation of the H I disk warp. We calculate a lower limit to the integrated luminosity of the structure of -12.7 ± 0.5 mag, comparable to a bright dwarf galaxy such as Fornax or Andromeda II and slightly less than 1% of the total luminosity of M33. Further, we show that there is tentative evidence for a distortion in the distribution of young stars near the edge of the H I disk that occurs at similar azimuth to the warp in H I. The data also hint at a low-level, extended stellar component at larger radius that may be an M33 halo component. We revisit studies of M33 and its stellar populations in light of these new results and discuss possible formation scenarios for the vast stellar structure. Our favored model is that of the tidal disruption of M33 in its orbit around M31.

  1. Discovery of a Probable Nova in M33

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Vaduvescu, O.; Tudor, V.

    2014-08-01

    We report the discovery of a probable nova in M33 on co-added 960-s narrow-band H-alpha and 480-s R-band CCD images taken with the 2.5-m Isaac Newton Telescope (INT) + WFC at La Palma under ~1.1" seeing on 2014 July 29.206 and 29.222 UT, respectively.

  2. NEW UBVRI PHOTOMETRY OF 234 M33 STAR CLUSTERS

    SciTech Connect

    Ma Jun

    2013-04-15

    This is the second paper of our series. In this paper, we present UBVRI photometry for 234 star clusters in the field of M33. For most of these star clusters, there is photometry in only two bands in previous studies. The photometry of these star clusters is performed using archival images from the Local Group Galaxies Survey, which covers 0.8 deg{sup 2} along the major axis of M33. Detailed comparisons show that, in general, our photometry is consistent with previous measurements, and in particular that our photometry is in good agreement with that of Zloczewski and Kaluzny. Combined with star cluster photometry in previous studies, we present some results: none of the M33 youngest clusters ({approx}10{sup 7} yr) have masses approaching 10{sup 5} M{sub Sun }, and comparisons with models of simple stellar populations suggest a large range of ages for M33 star clusters and some as old as the Galactic globular clusters.

  3. Romano's Star in M33: LBV Candidate or LBV?

    NASA Astrophysics Data System (ADS)

    Kurtev, R.; Sholukhova, O.; Borissova, J.; Georgiev, L.

    2001-04-01

    We present the light curve of the Luminous Blue Variable candidate star GR 290 (Romano's star) in M33. The photographic photometry was made in photographic plates taken in B band of the M33 galaxy and cover an eight year period, 1982 -- 1990. Twenty five plates, separated in seven groups, have been used. CCD B magnitude of the star is also presented. The analysis of our data together with the Romano's magnitudes (1978) shows ``normal'' eruptions with amplitude of more than 1 mag and timescale of about 20 years and smaller oscillations with amplitude 0.5 mag and a period of about 320 days. This is a typical photometrical behavior for LBVs.

  4. Cepheids and Long Period Variables in M 33

    NASA Astrophysics Data System (ADS)

    Pellerin, Anne; Macri, Lucas M.; Bradshaw, Andrew K.; Stanek, Krzysztof Z.

    2009-09-01

    We are conducting a long-term photometric survey of the nearby galaxy M 33 to discover Cepheids, eclipsing binaries, and long-period variables. The dataset combines previously-obtained optical images from the DIRECT project with new observations acquired at the WIYN 3.5 m telescope. The entire data set spans over 7 years with excellent synoptic coverage which will enable the discovery and characterization of stars displaying variability over a wide range of timescales (days, weeks, months, years). In this preliminary work we show representative light curves of different variables we found so far in two fields, color-magnitude diagrams, and optical Cepheid Period-Luminosity relations for M 33. The ultimate goal of the project is to provide an absolute calibration of the Cepheid Period-Luminosity relation, and to study its metallicity dependence at optical wavelengths.

  5. The Red Supergiants of M33: Determining Physical Properties

    NASA Astrophysics Data System (ADS)

    Beck, Madeleine; Massey, Philip

    2017-01-01

    We investigate a sample of red supergiants in the nearby unbarred spiral galaxy M33 with the goals of (1) determining the physical properties of these stars, (2) understanding the effects of metallicity on massive star evolution, and (3) comparing results to current models proposed by the Geneva group. M33 provides an ideal environment in which to conduct this examination because of a gradient of metallicity within its disk as well as its proximity to the Milky Way, which allows us to observe a complete sample of red supergiants. We employ MARCS atmosphere models and fit spectral features of our stars to determine effective temperatures and spectral types, then we use this information in combination with photometry to calculate bolometric luminosities. After placing these objects on the H-R diagram, we notice some discrepancies with what the Geneva solar-metallicity evolutionary tracks (Ekstrom et al. 2012) predict, namely that the tracks may not extend to cool enough temperatures and high enough luminosities and masses to comply with what we see observationally. We propose this may be the result of a mismatch between M33’s metallicity and the solar-metallicity Geneva models; we hope to make comparisons in the future as these new evolutionary tracks become available. This work was supported by the NSF through grant numbers AST-1461200 and AST-1612874.

  6. A high-resolution mosaic of HI in M33

    NASA Astrophysics Data System (ADS)

    Thilker, D. A.; Braun, R.; Walterbos, R. A. M.

    2000-12-01

    We have completed a high-resolution VLA/WSRT survey of HI in M33. Our data comprise the most detailed HI observations ever obtained for a spiral galaxy other than the Milky Way and reveal many striking properties of the neutral atomic gas. Spatial resolution of 20 pc (assuming a distance of 840 kpc) permits identification of expanding bubbles smaller than those cataloged by Deul & den Hartog, in addition to HI counterparts of discrete dust clouds. Likewise, we find a complex morphological relationship between HI and HII components. Velocity sampling of 1.3 km/s was achieved, thereby permitting the study of line profile variations as a function of environment within M33. A possible dark companion to M33 has been discovered using our WSRT observations. Deep 100m-class, single dish observations or D-configuration VLA images are needed to follow-up this lead, and exclude the possibility of a Galactic HVC explanation. This poster summarizes our initial analysis of the new dataset.

  7. Arecibo Search for Radio Pulses from M33

    NASA Astrophysics Data System (ADS)

    Crawford, Fronefield; Cordes, James M.; Spitler, Laura

    2016-01-01

    All radio pulsars that have been discovered to date are located within the Milky Way and its globular clusters, or in the Magellanic Clouds. The increased sensitivity of the wide-bandwidth Puerto Rico Ultimate Pulsar Processing Instrument (PUPPI) installed at the Arecibo Observatory makes detection of pulsars beyond the Magellanic Clouds a promising possibility. We are using the PUPPI backend and the 327 MHz receiver at Arecibo to try to detect giant radio pulses from neutron stars in the nearby spiral galaxy M33. Pulsars in M33 could be used to probe the local intergalactic medium and would help us study neutron star formation and pulsar evolution in another spiral galaxy. Using the Crab pulsar as a guide, we estimate that giant pulses from every Crab-like pulsar beaming toward us from the M33 optical disk ought to be detectable in our search, with several pulses detected in each hour of integration time. In this presentation I describe this project and provide an update on the status of the search.

  8. GALEX catalogue of UV point sources in M33

    NASA Astrophysics Data System (ADS)

    Mudd, Dale; Stanek, K. Z.

    2015-07-01

    The hottest stars (>10 000 K), and by extension typically the most massive ones, are those that will be prevalent in the ultraviolet (UV) portion of the electromagnetic spectrum, and we expect to numerous B, O and WR (WR) stars to be bright in UV data. In this paper, we update the previous point source UV catalogue of M33, created using the Ultraviolet Imaging Telescope (UIT), using data from the Galaxy Evolution Explorer (GALEX). We utilize point spread function photometry to optimally photometer sources in the crowded regions of the galaxy, and benefit from GALEX's increased sensitivity compared to UIT. We match our detections with data from the Local Group Galaxies Survey to create a catalogue with photometry spanning from the far-UV through the optical for a final list of 24 738 sources. All of these sources have far-UV (FUV; 1516 Å), near-UV (NUV; 2267 Å) and V data, and a significant fraction also have U, B, R and I data as well. We also present an additional 3000 sources that have no matching optical counterpart. We compare all of our sources to a catalogue of known WR stars in M33 and find that we recover 114 of 206 stars with spatially-coincident UV point sources. Additionally, we highlight and investigate those sources with unique colours as well as a selection of other well-studied sources in M33.

  9. Structural Parameters for 10 Halo Globular Clusters in M33

    NASA Astrophysics Data System (ADS)

    Ma, Jun

    2015-05-01

    In this paper, we present the properties of 10 halo globular clusters (GCs) with luminosities L ≃ 5-7 × 105 L⊙ in the Local Group galaxy M33 using images from the Hubble Space Telescope WFPC2 in the F555W and F814W bands. We obtained the ellipticities, position angles, and surface brightness profiles for each GC. In general, the ellipticities of the M33 sample clusters are similar to those of the M31 clusters. The structural and dynamical parameters are derived by fitting the profiles to three different models combined with mass-to-light ratios (M/L values) from population-synthesis models. The structural parameters include core radii, concentration, half-light radii, and central surface brightness. The dynamical parameters include the integrated cluster mass, integrated binding energy, central surface mass density, and predicted line of sight velocity dispersion at the cluster center. The velocity dispersions of the four clusters predicted here agree well with the observed dispersions by Larsen et al. The results here showed that the majority of the sample halo GCs are better fitted by both the King model and the Wilson model than the Sérsic model. In general, the properties of the clusters in M33, M31, and the Milky Way fall in the same regions of parameter spaces. The tight correlations of cluster properties indicate a “fundamental plane” for clusters, which reflects some universal physical conditions and processes operating at the epoch of cluster formation.

  10. PHOTOMETRIC PROPERTIES OF THE M33 STAR CLUSTER SYSTEM

    SciTech Connect

    San Roman, Izaskun; Sarajedini, Ata; Aparicio, Antonio E-mail: ata@astro.ufl.ed

    2010-09-10

    We present a catalog of 2990 extended sources in a 1{sup 0} x 1{sup 0} area centered on M33 using the MegaCam camera on the 3.6 m Canada-France-Hawaii Telescope. The catalog includes 599 new candidate stellar clusters, 204 previously confirmed clusters, 1969 likely background galaxies, and 218 unknown extended objects. We present ugriz integrated magnitudes of the candidates and confirmed star clusters (SCs) as well as the full width at half maximum, ellipticity, and stellarity. Based on the properties of the confirmed SCs, we select a sub-sample of highly probable clusters composed of 246 objects. The integrated photometry of the complete cluster catalog reveals a wide range of colors of -0.4 < (g - r) < 1.5 and -1.0 < (r - i) < 1.0 with no obvious cluster subpopulations. Comparisons with models of simple stellar populations suggest a large range of ages some as old as {approx}10 Gyr. In addition, we find a sequence in the color-color diagrams that deviates from the expected direction of evolution. This feature could be associated with very young clusters (<10{sup 7} yr) possessing significant nebular emission. Analysis of the radial density distribution suggests that the cluster system of M33 has suffered from significant depletion possibly due to interactions with M31. We also detect a gap in the cluster distribution in the color-color diagram at (g - r) {approx_equal} 0.3 and (u - g) {approx_equal} 0.8. This gap could be interpreted as an evolutionary effect. This complete catalog provides promising targets for deep photometry and high-resolution spectroscopy to study the structure and star formation history of M33.

  11. STRUCTURAL PARAMETERS FOR 10 HALO GLOBULAR CLUSTERS IN M33

    SciTech Connect

    Ma, Jun

    2015-05-15

    In this paper, we present the properties of 10 halo globular clusters (GCs) with luminosities L ≃ 5–7 × 10{sup 5} L{sub ⊙} in the Local Group galaxy M33 using images from the Hubble Space Telescope WFPC2 in the F555W and F814W bands. We obtained the ellipticities, position angles, and surface brightness profiles for each GC. In general, the ellipticities of the M33 sample clusters are similar to those of the M31 clusters. The structural and dynamical parameters are derived by fitting the profiles to three different models combined with mass-to-light ratios (M/L values) from population-synthesis models. The structural parameters include core radii, concentration, half-light radii, and central surface brightness. The dynamical parameters include the integrated cluster mass, integrated binding energy, central surface mass density, and predicted line of sight velocity dispersion at the cluster center. The velocity dispersions of the four clusters predicted here agree well with the observed dispersions by Larsen et al. The results here showed that the majority of the sample halo GCs are better fitted by both the King model and the Wilson model than the Sérsic model. In general, the properties of the clusters in M33, M31, and the Milky Way fall in the same regions of parameter spaces. The tight correlations of cluster properties indicate a “fundamental plane” for clusters, which reflects some universal physical conditions and processes operating at the epoch of cluster formation.

  12. Nova M33N 2012-10a

    NASA Astrophysics Data System (ADS)

    Alothman, Nourah

    In this thesis I present a study and measurement of a Nova in M33 galaxy type N 2012-10a (which is type of binary star) using data that were collected by the ROTSE IIIb robotic telescope and another observatory. I study the fundamental properties of the light curve and determined the brightness and the velocity of this type of nova. I analyzed the spectra that were measured by the Hobby-Eberly Telescope (HET) at the McDonald Observatory. In addition, I compared this type of nova to other types of Novae.

  13. M33 @ Observatorio Astrofísico de Javalambre

    NASA Astrophysics Data System (ADS)

    Vázquez Ramió, H.; Ederoclite, A.; Lamadrid, J. L.; Blanco Siffert, B.; San Roman, I.; Cristóbal-Hornillos, D.; Varela, J.; Coelho, P.; Moles, M.; Cenarro, A. J.; Marín-Franch, A.; Díaz-Martín, C. M.; Iglesias Marzoa, R.; Tilve, V.; Rodríguez, S.; Maícas, N.; López San Juan, C.; Viironen, K.; Vilella Rojo, G.; Logroño García, R.; Abril Ibánez, J.

    2017-03-01

    M33, the Triangulum Galaxy, is a spiral galaxy in the Local Group. Given its brightness and its vicinity with Andromeda Galaxy (M31), it is one of the best studied objects of the Northern hemisphere. In this poster, we present observations carried out with the JAST/T80 at the Observatorio Astrofísico de Javalambre. The extraordinary field of view of this telescope allows us to study the stellar populations of the galaxy with a single observation. Moreover, repeated observations have provided us the possibility to follow a variety of variable stars, among them the nova ASASSN-15th.

  14. New deep minimum of Romano's Star in M33

    NASA Astrophysics Data System (ADS)

    Calabresi, Massimo; Rossi, Corinne; Gualandi, Roberto; Galeti, Silvia; Polcaro, Vito Francesco; Viotti, Roberto; Albanesi, Raniero; Anzellini, Fabio; Haver, Roberto; Caponetto, Paolo; Gorelli, Roberto

    2014-02-01

    After the luminosity minimum of 2007-2008 (V=18.6, Polcaro et al. 2011, AJ, 141, 18) and a moderate luminosity maximum at beginning 2011 (V=17.8), the Luminous Blue Variable GR290/Romano's Star in M33 has reached a new deep minimum with V=18.7 and R=18.4 in December 2013 which appears to be the deepest so far recorded in its known light history. Significant luminosity oscillations have been observed during the 2011-2013 declining phase.

  15. THE WIND OF VARIABLE C IN M33

    SciTech Connect

    Humphreys, Roberta M.; Davidson, Kris; Gordon, Michael S.; Weis, Kerstin; Burggraf, Birgitta; Bomans, D. J.; Martin, John C.

    2014-02-20

    We discuss the spectrum of Var C in M33 obtained just before the onset of its current brightening and its recent spectra during its present ''eruption'' or optically thick wind stage. These spectra illustrate the typical luminous blue variable (LBV) transition in apparent spectral type or temperature that characterizes the classical LBV or S Dor-type variability. LBVs are known to have slow, dense winds during their maximum phase. Interestingly, Var C had a slow wind even during its hot, quiescent stage in comparison with the normal hot supergiants with similar temperatures. Its outflow or wind speeds also show very little change between these two states.

  16. H-alpha Photometric Survey of M33

    NASA Astrophysics Data System (ADS)

    Blaha, Cindy; Massey, P.; Hodge, P.; Martin, R.; Gavilan, L.; Adhikari, A.

    2006-12-01

    We present the results of a photometric survey of optical emission line regions in M33. Using data from the Local Group Galaxy Survey (LGGS see Massey et al, 2006)), we created continuum-subtracted H-alpha, [OIII] and [SII] emission line images and used flux contours on the H-alpha images to define emission line regions. To date, we have obtained photometric measurements for over 2850 H -alpha emission regions, with a faint flux limit of 10 -15 ergs-sec-1-cm-2 in the outer regions of the galaxy. Our global H Ι region luminosity function displays a broad peak centered at a luminosity of 6 x 10 35 ergs-sec-1 and extends to fainter luminosities than previously published surveys. We used the H-alpha-defined emission regions to determine fluxes for the [OIII] and [SII] images and created RGB images combining the calibrated emission images from all three filters. These RGB emission line images are being used with our [OIII]/ H-alpha and [SII]/ H-alpha line ratios and published catalogs to develop visual diagnostic tools to identify H II regions, planetary nebulae and supernova remnants in M33. Additional results from the LGGS data are being presented elsewhere at this meeting; see Massey et al and McNeill et al.

  17. A Study of Structure in M33 Using Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Wittman, David Michael

    1997-08-01

    FASTTRAC (Fast Adaptive Secondary for Tip-Tilt Removal by Automatic Centroiding) is a tip-tilt secondary system which increases the angular resolution of images taken at Steward Observatory's 90' Bok and 61' Bigelow telescopes. K band imagery is gathered with the facility infrared camera and wavefront sensing is done with a small format charge-coupled device (CCD). I examine desirable characteristics of wavefront-sensing CCDs and evaluate the performance of the device used in FASTTRAC according to those criteria. The main drawback of the device is its low quantum efficiency due to frontside illumination. The read noise of the system is adequate, particularly for FASTTRAC which is generally assigned to bright time. The increased angular resolution provided by FASTTRAC is desirable for imaging crowded fields, such as those found in Local Group galaxies. Stellar photometry is a more powerful tool for studying the structure of these galaxies than is surface photometry, in which the light from all types of stars is mixed together. In particular, the distribution of old stars is representative of the underlying mass distribution, so these stars may be used to measure the overdensity in the arms of spiral galaxies. FASTTRAC was used to observe fields in M33, the nearest spiral which is not seen edge-on. These fields were observed in a range of seeing conditions and with guide stars of varying magnitudes and positions relative to the fields of interest. I analyze the performance of FASTTRAC in these varying conditions and offer some advice to future FASTTRAC observers. I also analyze the crowding in the M33 fields and conclude that, to K~16.5, it does not vary significantly with placement in or outside of a spiral arm. Therefore a coarsely-sampled, wide field survey of the populations of M33 will not be systematically biased by crowding. Therefore a survey covering 35' by 25' was conducted in I and K bands, covering all of M33 out to a deprojected radius of 16 prime. The

  18. Variation in the dust emissivity index across M 33 with Herschel and Spitzer (HerM 33es)

    NASA Astrophysics Data System (ADS)

    Tabatabaei, F. S.; Braine, J.; Xilouris, E. M.; Kramer, C.; Boquien, M.; Combes, F.; Henkel, C.; Relano, M.; Verley, S.; Gratier, P.; Israel, F.; Wiedner, M. C.; Röllig, M.; Schuster, K. F.; van der Werf, P.

    2014-01-01

    We study the wavelength dependence of the dust emission as a function of position and environment across the disk of M 33 using Spitzer and Herschel photometric data. M 33 is a Local Group spiral with slightly subsolar metallicity, which makes it an ideal stepping-stone to less regular and lower-metallicity objects such as dwarf galaxies and, probably, young-universe objects. Expressing the emissivity of the dust as a power law, the power-law exponent (β) was estimated from two independent approaches designed to properly treat the degeneracy between β and the dust temperature (T). Both β and T are higher in the inner than in the outer disk, contrary to reported β - T anti-correlations found in other sources. In the cold + warm dust model, the warm component and the ionized gas (Hα) have a very similar distribution across the galaxy, demonstrating that the model separates the components in an appropriate way. Both cold- and warm-dust column densities are high in star-forming regions and reach their maxima toward the giant star-forming complexes NGC 604 and NGC 595. β declines from close to 2 in the center to about 1.3 in the outer disk. β is positively correlated with star formation and with the molecular gas column, as traced by the Hα and CO emission. The lower dust-emissivity index in the outer parts of M 33 is most likely related to the reduced metallicity (different grain composition) and possibly to a different size distribution. It is not due to the decrease in stellar radiation field or temperature in a simple way because the far-infrared-bright regions in the outer disk also have a low β. Like most spirals, M 33 has a (decreasing) radial gradient in star formation and molecular-to-atomic gas ratio such that the regions bright in Hα or CO tend to trace the inner disk, which makes it difficult to distinguish between their effects on the dust. The assumption of a constant emissivity index β is obviously not appropriate.

  19. Functional Studies on Twenty Novel Naturally Occurring Melanocortin-4 Receptor Mutations

    PubMed Central

    Wang, Zhi-Qiang; Tao, Ya-Xiong

    2011-01-01

    The melanocortin-4 receptor (MC4R) is a G protein-coupled receptor critically involved in regulating energy balance. MC4R activation results in decreased food intake and increased energy expenditure. Genetic and pharmacological studies demonstrated that the MC4R regulation of energy balance is conserved from fish to mammals. In humans, more than 150 naturally occurring mutations in the MC4R gene have been identified. Functional study of mutant MC4Rs is an important component in proving the causal link between MC4R mutation and obesity as well as the basis of personalized medicine. In this article, we studied 20 MC4R mutations that were either not characterized or not fully characterized. We showed that 11 mutants had decreased or absent cell surface expression. D126Y was defective in ligand binding. Three mutants were constitutively active but had decreased cell surface expression. Eleven mutants had decreased basal signaling, with two mutants defective only in this parameter, suggesting that impaired basal signaling might also be a cause of obesity. Five mutants had normal functions. In summary, we provided detailed functional data for further studies on identifying therapeutic approaches for personalized medicine to treat patients harboring these mutations. PMID:21729752

  20. Inhibition of T cell receptor signaling by cholesterol sulfate, a naturally occurring derivative of membrane cholesterol

    PubMed Central

    Wang, Feng; Beck-García, Katharina; Zorzin, Carina; Schamel, Wolfgang W. A.; Davis, Mark M.

    2016-01-01

    Most adaptive immune responses require the activation of specific T cells through the T cell antigen receptor–CD3 complex (TCR). Here we show that cholesterol sulfate (CS), a naturally occurring analog of cholesterol, inhibits CD3 ITAM phosphorylation, a crucial first step in T cell activation. Biochemical studies show that CS disrupted TCR multimers, apparently by displacing cholesterol, known to bind TCRβ. Moreover, CS-deficient mice displayed a heightened sensitivity to a self-antigen, whereas increasing CS content by intrathymic injection inhibited thymic selection, indicating that this molecule is an intrinsic regulator of thymocyte development. These results reveal a regulatory role for CS in TCR signaling and thymic selection, highlighting the importance of the membrane microenvironment in modulating cell surface receptor activation. PMID:27213689

  1. Biased Signaling in Naturally Occurring Mutations in Human Melanocortin-3 Receptor Gene

    PubMed Central

    Yang, Fan; Huang, Hui; Tao, Ya-Xiong

    2015-01-01

    The melanocortin-3 receptor (MC3R) is primarily expressed in the hypothalamus and plays an important role in the regulation of energy homeostasis. Recently, some studies demonstrated that MC3R also signals through mitogen-activated protein kinases (MAPKs), especially extracellular signal-regulated kinases 1 and 2 (ERK1/2). ERK1/2 signaling is known to alter gene expression, potentially contributing to the prolonged action of melanocortins on energy homeostasis regulation. In the present study, we performed detailed functional studies on 8 novel naturally occurring MC3R mutations recently reported, and the effects of endogenous MC3R agonist, α-melanocyte stimulating hormone (MSH), on ERK1/2 signaling on all 22 naturally occurring MC3R mutations reported to date. We found that mutants D158Y and L299V were potential pathogenic causes to obesity. Four residues, F82, D158, L249 and L299, played critical roles in different aspects of MC3R function. α-MSH exhibited balanced activity in Gs-cAMP and ERK1/2 signaling pathways in 15 of the 22 mutant MC3Rs. The other 7 mutant MC3Rs were biased to either one of the signaling pathways. In summary, we provided novel data about the structure-function relationship of MC3R, identifying residues important for receptor function. We also demonstrated that some mutations exhibited biased signaling, preferentially activating one intracellular signaling pathway, adding a new layer of complexity to MC3R pharmacology. PMID:25798062

  2. A Deep XMM-Newton Legacy Survey of M33

    NASA Astrophysics Data System (ADS)

    Williams, Benjamin

    We propose for financial support that will allow us to reduce and analyze all XMM- Newton data relevant to an A09 deep XMM-Newton legacy survey of M33 covering the entire optical disk with a total of 700000 seconds of exposure time. These data will allow us to determine how the temperature and energetics of the hot interstellar medium (ISM) are affected by star formation, constrain the nature and dynamical masses of new pulsating and eclipsing X-ray binaries, and perform detailed statistical and spectral studies on the largest known extragalactic population of X-ray supernova remnants (SNRs). The support proposed here is crucial for the full analysis and publication of the entire data set. Measurements and model fitting of the spectra and timing of all of the discrete sources detected in our data will constrain the nature and dynamical masses of new pulsating and eclipsing X-ray binaries, as well as provide new insight into the origins of the X-ray SNRs. Spatially-resolved, spectral studies of the diffuse emission will allow us to determine how the temperature and energetics of the hot interstellar medium (ISM) are affected by star formation. Several members of our team have already performed similar analysis to those proposed using data from the deep Chandra ACIS-I survey of M33 (ChASeM33), and we intend to hire a postdoctoral research associate who has experience working with large XMM-Newton data sets. Therefore the techniques for making the measurements are well-understood; however, the deep Chandra ACIS-I survey of M33 does not provide sufficient soft response for detailed spectral measurements of the diffuse gas emission from dozens of individual star forming regions. To reliably determine the temperature structure of the interstellar gas of these regions, our simulations show that we need to go a factor of 10 deeper in the soft X-ray band than existing X-ray data, which will be achieved with our proposed observations. Furthermore, XMM-Newton studies of X

  3. Stellar structures in the outer regions of M 33

    NASA Astrophysics Data System (ADS)

    Grossi, M.; Hwang, N.; Corbelli, E.; Giovanardi, C.; Okamoto, S.; Arimoto, N.

    2011-09-01

    Aims: We present Subaru/Suprime-Cam deep V and I imaging of seven fields in the outer regions of M 33. Our aim is to search for stellar structures corresponding to extended Hi clouds found in a recent 21-cm survey of the galaxy. Three fields probe a large Hi complex to the southeastern (SE) side of the galaxy. An additional three fields cover the northwestern (NW) side of the galaxy along the Hi warp. A final target field was chosen further north, at a projected distance of approximately 25 kpc, to study part of the large stellar plume recently discovered around M 33. Methods: We analyse the stellar population at R > 10 kpc by means of V, I colour magnitude diagrams reaching the red clump. We constrain the age and metallicity of the different stellar populations, search for density enhancements that correspond to the Hi features, and investigate the radial surface distribution of the stars. Results: We find evolved stellar populations in all fields out to 120'(~30 kpc), while a diffuse population of young stars (~200 Myr) is detected out to a galactocentric radius of 15 kpc. The mean metallicity in the southern fields remains approximately constant at [M/H] = -0.7 beyond the edge of the optical disc, from 40'out to 80'. Along the northern fields probing the outer Hi disc, we also find a metallicity of [M/H] = -0.7 between 35'and 70'from the centre, which decreases to [M/H] = -1.0 at larger angular radii out to 120'. In the northernmost field, outside the disc extent, the stellar population of the large stellar plume possibly related to a M 33-M 31 interaction is on average more metal-poor ([M/H] = -1.3) and older (≳6 Gyr). Conclusions: An exponential disc with a large scale-length (~7 kpc) fits well the average distribution of stars detected in both the SE and NW regions from a galactocentric distance of 11 kpc out to 30 kpc. The stellar disc extends beyond the Hi disc. The stellar distribution at large radii is disturbed and, although there is no clear

  4. Parameters of the LBV Star V 532 in M33

    NASA Astrophysics Data System (ADS)

    Sarkisyan, A.; Sholukhova, O.; Fabrika, S.; Valeev, A.

    2017-06-01

    We present the results of spectroscopic study of the LBV (luminous blue variable) star V 532 in the galaxy M33 carried out with the SAO RAS telescope from 2009 to 2015. On the basis of these data and other photometric data, we produce spectral energy distributions (SED) of the star. From 1992 to 2015, its B-band stellar magnitude changed from 16.2 to 18.6. The spectrum also changed considerably. Assuming that bolometric luminosity of LBV stars is constant (this property is inherent for LBV stars), we used SEDs to determine the star temperature and radius in different states and the value of interstellar extinction. From 1992 to 2015, the star temperature changed from ≍15000 K to ≍40000 K, the radius changed from ≍150R⊙ to ≍20R⊙ respectively. The value AV is 0.6±0.1. The absolute bolometric stellar magnitude is -10.2±0.2.

  5. THE M 33 SYNOPTIC STELLAR SURVEY. I. CEPHEID VARIABLES

    SciTech Connect

    Pellerin, Anne; Macri, Lucas M. E-mail: lmacri@physics.tamu.edu

    2011-04-01

    We have conducted a ground-based BVI synoptic survey of the Local Group galaxy M 33 which covers most of its disk and spans a period of 7 years. The survey targets luminous, long-period variables such as Cepheids and Miras and combines images from the DIRECT project and follow-up observations at the WIYN 3.5 m telescope. This paper, the first in a series, presents the discovery and characterization of 564 Cepheid variables, which represent a factor of two increase over previous samples with calibrated point-spread function (PSF) photometry. We also describe the details of the observations and analysis of the survey data, including the use of archival Hubble Space Telescope images to characterize biases in our ground-based PSF photometry.

  6. Constraining annihilating dark matter by radio data of M33

    NASA Astrophysics Data System (ADS)

    Chan, Man Ho

    2017-08-01

    Recent studies of radio data put strong constraints on annihilation cross sections for dark matter. In this article, we provide the first analysis of using M33 radio data in constraining annihilating dark matter. The resulting constraints of annihilation cross sections for some channels are more stringent than that obtained from six years of Fermi Large Area Telescope (Fermi-LAT) gamma-ray observations of the Milky Way dwarf spheroidal satellite galaxies. In particular, the conservative lower limits of dark matter mass annihilating via e+e-, μ+μ- and τ+τ- channels are 190, 120 and 70 GeV, respectively, with the thermal relic annihilation cross section. These results are in significant tension with some of the recent quantitative analyses of the AMS-02 and Fermi-LAT data of the Milky Way center.

  7. THE YELLOW AND RED SUPERGIANTS OF M33

    SciTech Connect

    Drout, Maria R.; Massey, Philip; Meynet, Georges E-mail: phil.massey@lowell.edu

    2012-05-10

    Yellow and red supergiants are evolved massive stars whose numbers and locations on the Hertzsprung-Russell (H-R) diagram can provide a stringent test for models of massive star evolution. Previous studies have found large discrepancies between the relative number of yellow supergiants (YSGs) observed as a function of mass and those predicted by evolutionary models, while a disagreement between the predicted and observed locations of red supergiants (RSGs) on the H-R diagram was only recently resolved. Here, we extend these studies by examining the YSG and RSG populations of M33. Unfortunately, identifying these stars is difficult as this portion of the color-magnitude diagram is heavily contaminated by foreground dwarfs. We identify the RSGs through a combination of radial velocities and a two-color surface gravity discriminant, and after re-characterizing the rotation curve of M33 with our newly selected RSGs, we identify the YSGs through a combination of radial velocities and the strength of the O I {lambda}7774 triplet. We examine {approx}1300 spectra in total and identify 121 YSGs (a sample that is unbiased in luminosity above log (L/L{sub Sun }) {approx} 4.8) and 189 RSGs. After placing these objects on the H-R diagram, we find that the latest generation of Geneva evolutionary tracks shows excellent agreement with the observed locations of our RSGs and YSGs, the observed relative number of YSGs with mass, and the observed RSG upper mass limit. These models therefore represent a drastic improvement over previous generations.

  8. PACS and SPIRE photometer maps of M 33: First results of the HERschel M 33 Extended Survey (HERM33ES)

    NASA Astrophysics Data System (ADS)

    Kramer, C.; Buchbender, C.; Xilouris, E. M.; Boquien, M.; Braine, J.; Calzetti, D.; Lord, S.; Mookerjea, B.; Quintana-Lacaci, G.; Relaño, M.; Stacey, G.; Tabatabaei, F. S.; Verley, S.; Aalto, S.; Akras, S.; Albrecht, M.; Anderl, S.; Beck, R.; Bertoldi, F.; Combes, F.; Dumke, M.; Garcia-Burillo, S.; Gonzalez, M.; Gratier, P.; Güsten, R.; Henkel, C.; Israel, F. P.; Koribalski, B.; Lundgren, A.; Martin-Pintado, J.; Röllig, M.; Rosolowsky, E.; Schuster, K. F.; Sheth, K.; Sievers, A.; Stutzki, J.; Tilanus, R. P. J.; van der Tak, F.; van der Werf, P.; Wiedner, M. C.

    2010-07-01

    Context. Within the framework of the HERM33ES key program, we are studying the star forming interstellar medium in the nearby, metal-poor spiral galaxy M 33, exploiting the high resolution and sensitivity of Herschel. Aims: We use PACS and SPIRE maps at 100, 160, 250, 350, and 500 μm wavelength, to study the variation of the spectral energy distributions (SEDs) with galacto-centric distance. Methods: Detailed SED modeling is performed using azimuthally averaged fluxes in elliptical rings of 2 kpc width, out to 8 kpc galacto-centric distance. Simple isothermal and two-component grey body models, with fixed dust emissivity index, are fitted to the SEDs between 24 μm and 500 μm using also MIPS/Spitzer data, to derive first estimates of the dust physical conditions. Results: The far-infrared and submillimeter maps reveal the branched, knotted spiral structure of M 33. An underlying diffuse disk is seen in all SPIRE maps (250-500 μm). Two component fits to the SEDs agree better than isothermal models with the observed, total and radially averaged flux densities. The two component model, with β fixed at 1.5, best fits the global and the radial SEDs. The cold dust component clearly dominates; the relative mass of the warm component is less than 0.3% for all the fits. The temperature of the warm component is not well constrained and is found to be about 60 K ± 10 K. The temperature of the cold component drops significantly from ~24 K in the inner 2 kpc radius to 13 K beyond 6 kpc radial distance, for the best fitting model. The gas-to-dust ratio for β = 1.5, averaged over the galaxy, is higher than the solar value by a factor of 1.5 and is roughly in agreement with the subsolar metallicity of M 33. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  9. Naturally occurring marine brominated indoles are aryl hydrocarbon receptor ligands/agonists.

    PubMed

    DeGroot, Danica E; Franks, Diana G; Higa, Tatsuo; Tanaka, Junichi; Hahn, Mark E; Denison, Michael S

    2015-06-15

    The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that mediates the toxic and biological effects of structurally diverse chemicals, including the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). As part of a larger effort to identify the full spectrum of chemicals that can bind to and activate the AhR, we have examined the ability of several naturally occurring marine-derived brominated indoles and brominated (methylthio)indoles (collectively referred to as brominated indoles) to bind to the AhR and stimulate AhR-dependent gene expression. Incubation of mouse, rat, and guinea pig recombinant cell lines containing a stably transfected AhR-responsive luciferase reporter gene with eight brominated indoles revealed that all compounds stimulated luciferase reporter gene activity, although some species-specific differences were observed. All compounds induced significantly more luciferase activity when incubated with cells for 4 h as compared to 24 h, demonstrating that these compounds are transient activators of the AhR signaling pathway. Three of the brominated indoles induced CYP1A1 mRNA in human HepG2 cells in vitro and Cyp1a mRNA in zebrafish embryos in vivo. The identification of the brominated indoles as direct ligands and activators/agonists of the AhR was confirmed by their ability to compete with [(3)H]TCDD for binding to the AhR and to stimulate AhR transformation and DNA binding in vitro. Taken together, these results indicate that marine-derived brominated indoles are members of a new class of naturally occurring AhR agonists.

  10. Naturally-Occurring Marine Brominated Indoles are Aryl Hydrocarbon Receptor Ligands/Agonists

    PubMed Central

    DeGroot, Danica E.; Franks, Diana G.; Higa, Tatsuo; Tanaka, Junichi; Hahn, Mark E.; Denison, Michael S.

    2015-01-01

    The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that mediates the toxic and biological effects of structurally diverse chemicals, including the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). As part of a larger effort to identify the full spectrum of chemicals that can bind to and activate the AhR, we have examined the ability of several naturally-occurring marine-derived brominated indoles and brominated (methylthio)indoles (collectively referred to as “brominated indoles”) to bind to the AhR and stimulate AhR-dependent gene expression. Incubation of mouse, rat and guinea pig recombinant cell lines containing a stably transfected AhR-responsive luciferase reporter gene with eight brominated indoles revealed that all compounds stimulated luciferase reporter gene activity, although some species-specific differences were observed. All compounds induced significantly more luciferase activity when incubated with cells for 4 h as compared to 24 h, demonstrating that these compounds are transient activators of the AhR signaling pathway. Three of the brominated indoles induced CYP1A1 mRNA in human HepG2 cells in vitro and Cyp1a mRNA in zebrafish embryos in vivo. The identification of the brominated indoles as direct ligands and activators/agonists of the AhR was confirmed by their ability to compete with [3H]TCDD for binding to the AhR and to stimulate AhR transformation and DNA binding in vitro. Taken together, these marine-derived brominated indoles are members of a new class of naturally-occurring AhR agonists. PMID:26001051

  11. Naturally occurring PDGF receptor inhibitors with potential anti-atherosclerotic properties.

    PubMed

    Ricci, Chiara; Ferri, Nicola

    2015-07-01

    Platelet-derived growth factor (PDGF) represents one of the most prominent inducer of smooth muscle cell (SMC) migration and proliferation. Homo- and heterodimers of PDGF-A, PDGF-B, PDGF-C and PDGF-D subunits act by binding to homo- or heterodimers of the PDGF tyrosine kinase receptors, PDGFR-α and PDGFR-β. The essential role of PDGFR signaling on restenosis post-angioplasty or atherosclerosis has been demonstrated by using blocking antibodies to PDGF or the tyrosine kinase inhibitor imatinib. More specifically, molecular studies have defined the intracellular signaling pathways activated by PDGF, inducing the cell cycle progression and the migration of SMCs. Considering the relevant role of PDGF in atherogenesis, several studies have been performed to investigate the effect of naturally occurring compounds on both in vitro and in vivo experimental models of atherogenesis. The present review will briefly summarize the pathophysiological role of PDGF and the studies of natural inhibitors tested in in vivo experimental models of restenosis in response to vascular injury and/or atherosclerosis.

  12. THE NEUTRAL HYDROGEN BRIDGE BETWEEN M31 AND M33

    SciTech Connect

    Lockman, Felix J.; Free, Nicole L.; Shields, Joseph C.

    2012-08-15

    The Green Bank Telescope has been used to search for 21 cm H I emission over a large area between the galaxies M31 and M33 in an attempt to confirm at 9.'1 angular resolution the detection by Braun and Thilker of a very extensive neutral gas 'bridge' between the two systems at the level N{sub HI} Almost-Equal-To 10{sup 17} cm{sup -2}. We detect H I emission at several locations up to 120 kpc in projected distance from M31, at least half the distance to M33, with velocities similar to that of the galaxies, confirming the essence of the Braun and Thilker discovery. The H I does not appear to be associated with the extraplanar high-velocity clouds of either galaxy. In two places we measure N{sub HI} > 3 Multiplication-Sign 10{sup 18} cm{sup -2}, indicative of concentrations of H I with {approx}10{sup 5} M{sub Sun} on scales {approx}< 2 kpc, but over most of the field we have only 5{sigma} upper limits of N{sub HI} {<=} 1.4 Multiplication-Sign 10{sup 18} cm{sup -2}. In very deep measurements in two directions H I lines were detected at a few 10{sup 17} cm{sup -2}. The absence of emission at another location to a 5{sigma} limit N{sub HI} {<=} 1.5 Multiplication-Sign 10{sup 17} cm{sup -2} suggests that the H I bridge is either patchy or confined to within {approx}125 kpc of M31. The measurements also cover two of M31's dwarf galaxies, And II and And XV, but in neither case is there evidence for associated H I at the 5{sigma} level of 1.4 Multiplication-Sign 10{sup 4} M{sub Sun} for And II and 9.3 Multiplication-Sign 10{sup 3} M{sub Sun} for And XV.

  13. HI and Hα Mapping of M31 & M33

    NASA Astrophysics Data System (ADS)

    Kam, Z. S.; Carignan, C.; Chemin, L.; Hernandez, O.; de Denus-Baillargeon, M.; Djabo, Y.

    2011-12-01

    abstract-type="normal">RésuméWe performed a deep Hi and Hα mapping of M31 and M33 in order to get accurate kinematical data of those two galaxies and also to make a comparison between the Hi and Hα kinematics. The Hi data were obtained with the DRAO interferometer and the Hα data with the Fabry-Perot system of the Observatoire du mont Mégantic using an EMCCD as a detector. These data will give us the best possible datasets to derive accurate rotation curves and mass models for those two Local Group spirals and provide some new data for the Hii regions studies of these galaxies. While the Hi observations are of low resolution (~1 arcmin), the high resolution of the Hα data (~1 arcsec) should allow us to get much more details in the central regions, allowing at the same time a much better determination of the kinematical parameters. Hence, the inner part of the rotation curve, so inportant to constraint properly the mass models, will be determined more accurately.

  14. Properties of optically selected supernova remnant candidates in M33

    SciTech Connect

    Lee, Jong Hwan; Lee, Myung Gyoon E-mail: mglee@astro.snu.ac.kr

    2014-10-01

    Narrowband images covering strong emission lines are efficient for surveying supernova remnants (SNRs) in nearby galaxies. Using the narrowband images provided by the Local Group Galaxy Survey, we searched for SNRs in M33. Culling the objects with enhanced [S II]/Hα and round morphology in the continuum-subtracted Hα and [S II] images, we produced a list of 199 sources. Among them, 79 are previously unknown. Their progenitor and morphology types were classified. A majority of the sample (170 objects) are likely remnants of core-collapse supernovae (SNe), and 29 are remnants of Type Ia SNe. The cumulative size distribution of these objects is found to be similar to that of the M31 remnants derived in a similar way. We obtain a power-law slope, α = 2.38 ± 0.05. Thus, a majority of the sources are considered to be in the Sedov-Taylor phase, consistent with previous findings. The histogram of the emission-line ratio ([S II]/Hα) of the remnants has two concentrations at [S II]/Hα ∼ 0.55 and ∼0.8, as in M31. Interestingly, L {sub X} (and L {sub 20cm}) of the compact center-bright objects are correlated with their optical luminosity. The remnants with X-ray emission have brighter optical surface brightnesses and smaller diameters than those without X-ray emission.

  15. Three supernova shells around a young M33 star cluster

    NASA Astrophysics Data System (ADS)

    Camps-Fariña, A.; Beckman, J. E.; Font, J.; Borlaff, A.; Zaragoza-Cardiel, J.; Amram, P.

    2016-09-01

    Using a specialized technique sensitive to the presence of expanding ionized gas, we have detected a set of three concentric expanding shells in an H II region in the nearby spiral galaxy M33. After mapping the kinematics in Hα with Fabry-Perot spectroscopy, we used slit spectra to measure the intensities of the [S II] doublet at λλ671.9, 673.1 nm and the [N II] doublet at λλ645.8, 658.3 nm to corroborate the kinematics and apply diagnostic tests using line ratios. These showed that the expanding shells are shock dominated as would be the case if they had originated with supernova explosions. Estimating their kinetic energies, we find fairly low values, indicating a fairly advanced stage of evolution. We obtain density, mass and parent star mass estimates, which, along with the kinetic energies, are inconsistent with the simplest models of shock-interstellar medium interaction. We propose that the presence and properties of an inhomogeneous medium offer a scenario which can account for these observations, and discuss the implications. Comparing our results with data from the literature supports the combined presence of an H II region and supernova remnant material at the observed position.

  16. Integral field spectroscopy of H II regions in M33

    NASA Astrophysics Data System (ADS)

    López-Hernández, Jesús; Terlevich, Elena; Terlevich, Roberto; Rosa-González, Daniel; Díaz, Ángeles; García-Benito, Rubén; Vílchez, José; Hägele, Guillermo

    2013-03-01

    Integral field spectroscopy is presented for star-forming regions in M33. A central area of 300 × 500 pc2 and the external H II region IC 132, at a galactocentric distance ˜19 arcmin (4.69 kpc), were observed with the Potsdam Multi-Aperture Spectrophotometer instrument at the 3.5-m telescope of the Centro Astronómico Hispano-Alemán (CAHA, aka Calar Alto Observatory). The spectral coverage goes from 3600 Å to 1 μm to include from [O II] λ3727 Å to the near-infrared lines required for deriving sulphur electron temperature and abundance diagnostics. Local conditions within individual H II regions are presented in the form of emission-line fluxes and physical conditions for each spatial resolution element (spaxel) and for segments with similar Hα surface brightness. A clear dichotomy is observed when comparing the central to outer disc H II regions. While the external H II region has higher electron temperature plus larger Hβ equivalent width, size and excitation, the central region has higher extinction and metal content. The dichotomy extends to the Baldwin-Phillips-Terlevich (BPT) diagnostic diagrams that show two orthogonal broad distributions of points. By comparing with pseudo-3D photoionization models, we conclude that the bulk of observed differences are probably related to a different ionization parameter and metallicity. Wolf-Rayet (WR) features are detected in IC 132, and resolved into two concentrations whose integrated spectra were used to estimate the characteristic number of WR stars. No WR features were detected in the central H II regions despite their higher metallicity.

  17. Radial dependence of the dark matter distribution in M33

    NASA Astrophysics Data System (ADS)

    López Fune, E.; Salucci, P.; Corbelli, E.

    2017-06-01

    The stellar and gaseous mass distributions, as well as the extended rotation curve, in the nearby galaxy M33 are used to derive the radial distribution of dark matter density in the halo and to test cosmological models of galaxy formation and evolution. Two methods are examined to constrain the dark mass density profiles. The first method deals directly with fitting the rotation curve data in the range of galactocentric distances 0.24 ≤ r ≤ 22.72 kpc. Using the results of collisionless Λ cold dark matter numerical simulations, we confirm that the Navarro-Frenkel-White (NFW) dark matter profile provides a better fit to the rotation curve data than the cored Burkert profile (BRK) profile. The second method relies on the local equation of centrifugal equilibrium and on the rotation curve slope. In the aforementioned range of distances, we fit the observed velocity profile, using a function that has a rational dependence on the radius, and we derive the slope of the rotation curve. Then, we infer the effective matter densities. In the radial range 9.53 ≤ r ≤ 22.72 kpc, the uncertainties induced by the luminous matter (stars and gas) become negligible, because the dark matter density dominates, and we can determine locally the radial distribution of dark matter. With this second method, we tested the NFW and BRK dark matter profiles and we can confirm that both profiles are compatible with the data, even though in this case the cored BRK density profile provides a more reasonable value for the baryonic-to-dark matter ratio.

  18. The present status of four luminous variables in M 33

    NASA Astrophysics Data System (ADS)

    Viotti, R. F.; Rossi, C.; Polcaro, V. F.; Montagni, F.; Gualandi, R.; Norci, L.

    2006-10-01

    Context: . Understanding the origin of the instabilities of LBVs is important for shedding light on the late evolutionary stages of massive stars and on the chemical evolution of galaxies. Aims: . To investigate the physical nature of variable stars in the upper H-R diagram, we performed a spectrophotometric study of the Romano's star GR 290 and the Hubble-Sandage variables A, B, and C in the close galaxy M 33. Methods: . New spectroscopic and photometric data were employed in conjunction with already published data of these stars in order to derive spectral types, energy distribution and bolometric luminosities. Results: . The yellow hypergiant Var A is still at minimum, with a ~G-type spectrum and strong Hα emission (W_eq ≃ -35 Å). Var B is in a low luminosity hot state (V=17.5, B-V = -0.15) with very strong Hα emission (W_eq=-310 Å). Its absolute bolometric luminosity is 0.6× 106 L⊙. Var C, at V=16.4, is fainter than in the mid 1980s, but its spectrum shows the typical features of LBVs at maximum, a spectrum that is very rich in Fe ii emission lines. Its L_bol is about 0.7× 106 L⊙. The Romano's star GR 290 has a rich hot emission-line spectrum and is very bright with L_bol=3× 106 L⊙. During 2004 the star brightened by ~half magnitude in each of the BVR filters. Conclusions: . Our observations confirm that Var A probably is an intermediate type hypergiant star surrounded by an expanding envelope with a collisionally excited hydrogen emission, largely obscured by dusty disk and nebula. In recent years, Var B has undergone a blueward transition in the H-R diagram, probably at constant bolometric luminosity, while Var C is in a post-maximum phase with an η Car-type spectrum. GR 290 is notable for its spectrum and luminosity, and it is likely to develop ample spectral variations in the near future, similar to those observed in AG Car.

  19. CHANDRA ACIS SURVEY OF M33 (ChASeM33): THE ENIGMATIC X-RAY EMISSION FROM IC131

    SciTech Connect

    Tuellmann, Ralph; Plucinsky, Paul P.; Gaetz, Terrance J.; Smith, Randall K.; Long, Knox S.; Pannuti, Thomas G.; Winkler, P. Frank; Williams, Ben; Kuntz, Kip D.; Blair, William P.; Pietsch, Wolfgang; Haberl, Frank

    2009-12-20

    We present the first X-ray analysis of the diffuse hot ionized gas and the point sources in IC131, after NGC604 the second most X-ray luminous giant H II region (GHR) in M33. The X-ray emission is detected only in the south eastern part of IC131 (named IC131-se) and is limited to an elliptical region of approx200 pc in extent. This region appears to be confined toward the west by a hemispherical shell of warm ionized gas and only fills about half that volume. Although the corresponding X-ray spectrum has 1215 counts, it cannot conclusively be told whether the extended X-ray emission is thermal, non-thermal, or a combination of both. A thermal plasma model of kT{sub e} = 4.3 keV or a single power law of GAMMA approx = 2.1 fit the spectrum equally well. If the spectrum is purely thermal (non-thermal), the total unabsorbed X-ray luminosity in the 0.35-8 keV energy band amounts to L{sub X} = 6.8(8.7) x 10{sup 35} erg s{sup -1}. Among other known H II regions IC131-se seems to be extreme regarding the combination of its large extent of the X-ray plasma, the lack of massive O stars, its unusually high electron temperature (if thermal), and the large fraction of L{sub X} emitted above 2 keV (approx40%-53%). A thermal plasma of approx4 keV poses serious challenges to theoretical models, as it is not clear how high electron temperatures can be produced in H II regions in view of mass-proportional and collisionless heating. If the gas is non-thermal or has non-thermal contributions, synchrotron emission would clearly dominate over inverse Compton emission. It is not clear if the same mechanisms which create non-thermal X-rays or accelerate cosmic rays in supernova remnants can be applied to much larger scales of 200 pc. In both cases the existing theoretical models for GHRs and superbubbles do not explain the hardness and extent of the X-ray emission in IC131-se. We also detect a variable source candidate in IC131. It seems that this object (CXO J013315.10+304453.0) is a

  20. Identification of a naturally occurring retinoid X receptor agonist from Brazilian green propolis.

    PubMed

    Nakashima, Ken-Ichi; Murakami, Tohru; Tanabe, Hiroki; Inoue, Makoto

    2014-10-01

    Brazilian green propolis (BGP), a resinous substance produced from Baccharis dracunculifolia by Africanized honey bees (Apis mellifera), is used as a folk medicine. Our present study explores the retinoid X receptor (RXR) agonistic activity of BGP and the identification of an RXR agonist in its extract. RXRα agonistic activity was evaluated using a luciferase reporter gene assay. Isolation of the RXRα agonist from the ethanolic extract of BGP was performed using successive silica gel and a reversed phase column chromatography. The interaction between the isolated RXRα agonist and RXRα protein was predicted by a receptor-ligand docking simulation. The nuclear receptor (NR) cofactor assay was used to estimate whether the isolated RXRα agonist bound to various NRs, including RXRs and peroxisome proliferator-activated receptors (PPARs). We further examined its effect on adipogenesis in 3T3-L1 fibroblasts. We identified drupanin as an RXRα agonist with an EC50 value of 4.8 ± 1.0 μM. Drupanin activated three RXR subtypes by a similar amount and activated PPARγ moderately. Additionally, drupanin induced adipogenesis and elevated aP2 mRNA levels in 3T3-L1 fibroblasts. Drupanin, a component of BGP, is a novel RXR agonist with slight PPARγ agonistic activity. This study revealed for the first time that BGP activates RXR and drupanin is an RXR agonist in its extract. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Characterization of a naturally occurring ecotropic receptor that does not facilitate entry of all ecotropic murine retroviruses.

    PubMed

    Eiden, M V; Farrell, K; Warsowe, J; Mahan, L C; Wilson, C A

    1993-07-01

    A fibroblast cell line (MDTF) derived from the feral mouse Mus dunni is resistant to infection by Moloney murine leukemia virus (Mo-MuLV), an ecotropic murine leukemia virus (E-MuLV) (M. R. Lander and S. K. Chattopadadhyay, J. Virol. 52:695-698, 1984). MDTF cells can be infected by other E-MuLVs such as Friend MuLV and Rauscher MuLV, which have been demonstrated to use the same receptor as Mo-MuLV in NIH 3T3 cells (A. Rein and A. Schultz, Virology 136:144-152, 1984). We have now shown that the block to Mo-MuLV infection of MDTF cells occurs at the level of the envelope-receptor interaction. We have cloned the ecotropic receptor cDNA from MDTF cells (dRec) and compared its sequence with that of the NIH 3T3 cell receptor (mRec). Although the deduced dRec and mRec proteins differ at only four amino acid residues, we demonstrate that these changes account for the resistance of MDTF cells to Mo-MuLV infection. Our findings suggest that retroviruses in the same receptor class can exhibit different host ranges due to single amino acid differences in their cellular receptor.

  2. Characterization of a naturally occurring ecotropic receptor that does not facilitate entry of all ecotropic murine retroviruses.

    PubMed Central

    Eiden, M V; Farrell, K; Warsowe, J; Mahan, L C; Wilson, C A

    1993-01-01

    A fibroblast cell line (MDTF) derived from the feral mouse Mus dunni is resistant to infection by Moloney murine leukemia virus (Mo-MuLV), an ecotropic murine leukemia virus (E-MuLV) (M. R. Lander and S. K. Chattopadadhyay, J. Virol. 52:695-698, 1984). MDTF cells can be infected by other E-MuLVs such as Friend MuLV and Rauscher MuLV, which have been demonstrated to use the same receptor as Mo-MuLV in NIH 3T3 cells (A. Rein and A. Schultz, Virology 136:144-152, 1984). We have now shown that the block to Mo-MuLV infection of MDTF cells occurs at the level of the envelope-receptor interaction. We have cloned the ecotropic receptor cDNA from MDTF cells (dRec) and compared its sequence with that of the NIH 3T3 cell receptor (mRec). Although the deduced dRec and mRec proteins differ at only four amino acid residues, we demonstrate that these changes account for the resistance of MDTF cells to Mo-MuLV infection. Our findings suggest that retroviruses in the same receptor class can exhibit different host ranges due to single amino acid differences in their cellular receptor. Images PMID:8510216

  3. Castration resistance in human prostate cancer is conferred by a frequently occurring androgen receptor splice variant

    PubMed Central

    Sun, Shihua; Sprenger, Cynthia C.T.; Vessella, Robert L.; Haugk, Kathleen; Soriano, Kathryn; Mostaghel, Elahe A.; Page, Stephanie T.; Coleman, Ilsa M.; Nguyen, Holly M.; Sun, Huiying; Nelson, Peter S.; Plymate, Stephen R.

    2010-01-01

    Progression of prostate cancer following castration is associated with increased androgen receptor (AR) expression and signaling despite AR blockade. Recent studies suggest that these activities are due to the generation of constitutively active AR splice variants, but the mechanisms by which these splice variants could mediate such effects are not fully understood. Here we have identified what we believe to be a novel human AR splice variant in which exons 5, 6, and 7 are deleted (ARv567es) and demonstrated that this variant can contribute to cancer progression in human prostate cancer xenograft models in mice following castration. We determined that, in human prostate cancer cell lines, ARv567es functioned as a constitutively active receptor, increased expression of full-length AR (ARfl), and enhanced the transcriptional activity of AR. In human xenografts, human prostate cancer cells transfected with ARv567es cDNA formed tumors that were resistant to castration. Furthermore, the ratio of ARv567es to ARfl expression within the xenografts positively correlated with resistance to castration. Importantly, we also detected ARv567es frequently in human prostate cancer metastases. In summary, these data indicate that constitutively active AR splice variants can contribute to the development of castration-resistant prostate cancers and may serve as biomarkers for patients who are likely to suffer from early recurrence and are candidates for therapies directly targeting the AR rather than ligand. PMID:20644256

  4. A naturally occurring insertion of a single amino acid rewires transcriptional regulation by glucocorticoid receptor isoforms.

    PubMed

    Thomas-Chollier, Morgane; Watson, Lisa C; Cooper, Samantha B; Pufall, Miles A; Liu, Jennifer S; Borzym, Katja; Vingron, Martin; Yamamoto, Keith R; Meijsing, Sebastiaan H

    2013-10-29

    In addition to guiding proteins to defined genomic loci, DNA can act as an allosteric ligand that influences protein structure and activity. Here we compared genome-wide binding, transcriptional regulation, and, using NMR, the conformation of two glucocorticoid receptor (GR) isoforms that differ by a single amino acid insertion in the lever arm, a domain that adopts DNA sequence-specific conformations. We show that these isoforms differentially regulate gene expression levels through two mechanisms: differential DNA binding and altered communication between GR domains. Our studies suggest a versatile role for DNA in both modulating GR activity and also in directing the use of GR isoforms. We propose that the lever arm is a "fulcrum" for bidirectional allosteric signaling, conferring conformational changes in the DNA reading head that influence DNA sequence selectivity, as well as conferring changes in the dimerization domain that connect functionally with remote regulatory surfaces, thereby influencing which genes are regulated and the magnitude of their regulation.

  5. Spitzer observations of M33 and the hot star, HII region connection

    NASA Astrophysics Data System (ADS)

    Rubin, Robert H.; Simpson, Janet P.; Colgan, Sean W. J.; Dufour, Reginald J.; Brunner, Gregory; McNabb, Ian A.; Pauldrach, Adalbert W. A.; Erickson, Edwin F.; Haas, Michael R.; Citron, Robert I.

    2008-06-01

    We have observed emission lines of [SIV] 10.51, H(7-6) 12.37, [NeII] 12.81, [NeIII] 15.56 and [SIII] 18.71 μm in a number of extragalactic HII regions with the Spitzer Space Telescope. A previous paper presented our data and analysis for the substantially face-on spiral galaxy M83. Here we report our results for the Local Group spiral galaxy M33. The nebulae selected cover a wide range of galactocentric radii (RG). The observations were made with the Infrared Spectrograph with the short wavelength, high-resolution module. The above set of five lines is observed cospatially, thus permitting a reliable comparison of the fluxes. From the measured fluxes, we determine the ionic abundance ratios including Ne++/Ne+, S3+/S++, and S++/Ne+ and find that there is a correlation of increasingly higher ionization with larger RG. By sampling the dominant ionization states of Ne (Ne+, Ne++) and S (S++, S3+) for HII regions, we can estimate the Ne/H, S/H and Ne/S ratios. We find from linear least-squares fits that there is a decrease in metallicity with increasing RG: dlog(Ne/H)/dRG = -0.058 +/- 0.014 and dlog(S/H)/dRG = -0.052 +/- 0.021 dex kpc-1. There is no apparent variation in the Ne/S ratio with RG. Unlike our previous similar study of M83, where we conjectured that this ratio was an upper limit, for M33 the derived ratios are likely a robust indication of Ne/S. This occurs because the HII regions have lower metallicity and higher ionization than those in M83. Both Ne and S are primary elements produced in α-chain reactions, following C and O burning in stars, making their yields depend very little on the stellar metallicity. Thus, it is expected that the Ne/S ratio remains relatively constant throughout a galaxy. The median (average) Ne/S ratio derived for HII regions in M33 is 16.3 (16.9), just slightly higher than the Orion Nebula value of 14.3. The same methodology is applied to Spitzer observations recently published for three massive HII regions: NGC 3603 (Milky Way

  6. Observations of M33 H II Regions: the Ne/S ratio, metallicity, and ionization variations

    NASA Astrophysics Data System (ADS)

    Rubin, R. H.; Simpson, J. P.; McNabb, I. A.; Brunner, G.; Colgan, S. W. J.; Dufour, R. J.; Pauldrach, A. W. A.; Browne, A. D.; Zhang, R.; Csongradi, E. J.

    2009-01-01

    We have observed emission lines of [S IV] 10.51, H(7--6) 12.37, [Ne II] 12.81, [Ne III] 15.56, and [S III] 18.71 μm in a number of extragalactic H II regions with the Spitzer Space Telescope. A previous paper presented our data and analysis for the substantially face-on spiral galaxy M83. Here we report our results for the local group spiral galaxy M33. The nebulae selected cover a wide range of galactocentric radii (R_G). The observations were made with the Infrared Spectrograph with the short wavelength, high resolution module. The above set of five lines is observed cospatially, thus permitting a reliable comparison of the fluxes. From the measured fluxes, we determine the ionic abundance ratios including Ne++/Ne^+, S3+/S++, and S++/Ne^+ and find that there is a correlation of increasingly higher ionization with larger R_G. By sampling the dominant ionization states of Ne (Ne^+, Ne++) and S (S++, S3+) for H II regions, we can estimate the Ne/H, S/H, and Ne/S ratios. We find that there is a decrease in metallicity with increasing R_G. There is no apparent variation in the Ne/S ratio with R_G. Unlike our previous similar study of M83, where we conjectured that this ratio was an upper limit, for M33 the derived ratios are likely a robust indication of Ne/S. This occurs because the H II regions have lower metallicity and higher ionization than those in M83. Both Ne and S are primary elements produced in α-chain reactions, following C and O burning in stars, making their yields depend very little on the stellar metallicity. Thus, it is expected that Ne/S remains relatively constant throughout a galaxy. The median (average) Ne/S ratio derived for H II regions in M33 is 16.3 (16.9), just slightly higher than the Orion Nebula value of 14.3. These values are in sharp contrast with the much lower ``canonical", but controversial, solar value of ˜5. A recent nucleosynthesis, galactic chemical evolution model predicts a Ne/S abundance of ˜9. Our observations may also be

  7. A 15.65-solar-mass black hole in an eclipsing binary in the nearby spiral galaxy M 33.

    PubMed

    Orosz, Jerome A; McClintock, Jeffrey E; Narayan, Ramesh; Bailyn, Charles D; Hartman, Joel D; Macri, Lucas; Liu, Jiefeng; Pietsch, Wolfgang; Remillard, Ronald A; Shporer, Avi; Mazeh, Tsevi

    2007-10-18

    Stellar-mass black holes are found in X-ray-emitting binary systems, where their mass can be determined from the dynamics of their companion stars. Models of stellar evolution have difficulty producing black holes in close binaries with masses more than ten times that of the Sun (>10; ref. 4), which is consistent with the fact that the most massive stellar black holes known so far all have masses within one standard deviation of 10. Here we report a mass of (15.65 +/- 1.45) for the black hole in the recently discovered system M 33 X-7, which is located in the nearby galaxy Messier 33 (M 33) and is the only known black hole that is in an eclipsing binary. To produce such a massive black hole, the progenitor star must have retained much of its outer envelope until after helium fusion in the core was completed. On the other hand, in order for the black hole to be in its present 3.45-day orbit about its (70.0 +/- 6.9) companion, there must have been a 'common envelope' phase of evolution in which a significant amount of mass was lost from the system. We find that the common envelope phase could not have occurred in M 33 X-7 unless the amount of mass lost from the progenitor during its evolution was an order of magnitude less than what is usually assumed in evolutionary models of massive stars.

  8. VizieR Online Data Catalog: M33 HII regions SED (Relano+, 2013)

    NASA Astrophysics Data System (ADS)

    Relano, M.; Verley, S.; Perez, I.; Kramer, C.; Calzetti, D.; Xilouris, E. M.; Boquien, M.; Abreu-Vicente, J.; Combes, F.; Israel, F.; Tabatabaei, F. S.; Braine, J.; Buchbender, C.; Gonzalez, M.; Gratier, P.; Lord, S.; Mookerjea, B.; Quintana-Lacaci, G.; van der Werf, P.

    2013-09-01

    To investigate the continuum UV emission of M 33, we used the data from GALEX, in particular the data distributed by de Paz et al. (2007, Cat. J/ApJS/173/185). To trace the ionised gas, we used the narrow-line Hα image of M 33 obtained by Greenawalt (1998, Ph.D. Thesis, New Mexico state University). Dust emission can be investigated through the mid-IR (MIR) and FIR data of M 33 obtained with the Spitzer Infrared Array Camera (IRAC) and Multiband Imaging Photometer (MIPS). (3 data files).

  9. Tethering naturally occurring peptide toxins for cell-autonomous modulation of ion channels and receptors in vivo.

    PubMed

    Ibañez-Tallon, Inés; Wen, Hua; Miwa, Julie M; Xing, Jie; Tekinay, Ayse B; Ono, Fumihito; Brehm, Paul; Heintz, Nathaniel

    2004-08-05

    The physiologies of cells depend on electrochemical signals carried by ion channels and receptors. Venomous animals produce an enormous variety of peptide toxins with high affinity for specific ion channels and receptors. The mammalian prototoxin lynx1 shares with alpha-bungarotoxin the ability to bind and modulate nicotinic receptors (nAChRs); however, lynx1 is tethered to the membrane via a GPI anchor. We show here that several classes of neurotoxins, including bungarotoxins and cobratoxins, retain their selective antagonistic properties when tethered to the membrane. Targeted elimination of nAChR function in zebrafish can be achieved with tethered alpha-bungarotoxin, silencing synaptic transmission without perturbing synapse formation. These studies harness the pharmacological properties of peptide toxins for use in genetic experiments. When combined with specific methods of cell and temporal expression, the extension of this approach to hundreds of naturally occurring peptide toxins opens a new landscape for cell-autonomous regulation of cellular physiology in vivo. Copyright 2004 Cell Press

  10. Naturally Occurring Eccentric Cleavage Products of Provitamin A β-Carotene Function as Antagonists of Retinoic Acid Receptors*

    PubMed Central

    Eroglu, Abdulkerim; Hruszkewycz, Damian P.; dela Sena, Carlo; Narayanasamy, Sureshbabu; Riedl, Ken M.; Kopec, Rachel E.; Schwartz, Steven J.; Curley, Robert W.; Harrison, Earl H.

    2012-01-01

    β-Carotene is the major dietary source of provitamin A. Central cleavage of β-carotene catalyzed by β-carotene oxygenase 1 yields two molecules of retinaldehyde. Subsequent oxidation produces all-trans-retinoic acid (ATRA), which functions as a ligand for a family of nuclear transcription factors, the retinoic acid receptors (RARs). Eccentric cleavage of β-carotene at non-central double bonds is catalyzed by other enzymes and can also occur non-enzymatically. The products of these reactions are β-apocarotenals and β-apocarotenones, whose biological functions in mammals are unknown. We used reporter gene assays to show that none of the β-apocarotenoids significantly activated RARs. Importantly, however, β-apo-14′-carotenal, β-apo-14′-carotenoic acid, and β-apo-13-carotenone antagonized ATRA-induced transactivation of RARs. Competitive radioligand binding assays demonstrated that these putative RAR antagonists compete directly with retinoic acid for high affinity binding to purified receptors. Molecular modeling studies confirmed that β-apo-13-carotenone can interact directly with the ligand binding site of the retinoid receptors. β-Apo-13-carotenone and the β-apo-14′-carotenoids inhibited ATRA-induced expression of retinoid responsive genes in Hep G2 cells. Finally, we developed an LC/MS method and found 3–5 nm β-apo-13-carotenone was present in human plasma. These findings suggest that β-apocarotenoids function as naturally occurring retinoid antagonists. The antagonism of retinoid signaling by these metabolites may have implications for the activities of dietary β-carotene as a provitamin A and as a modulator of risk for cardiovascular disease and cancer. PMID:22418437

  11. 'Entourage' effects of N-palmitoylethanolamide and N-oleoylethanolamide on vasorelaxation to anandamide occur through TRPV1 receptors.

    PubMed

    Ho, W-S V; Barrett, D A; Randall, M D

    2008-11-01

    The endocannabinoid N-arachidonoylethanolamide (anandamide) is co-synthesized with other N-acylethanolamides, namely N-palmitoylethanolamide (PEA) and N-oleoylethanolamide (OEA), which have been shown to potentiate anandamide responses (so-called 'entourage effects') in non-vascular tissues. It remains unclear whether such interactions occur in the circulation. In rat isolated small mesenteric arteries, the effects of PEA and OEA on relaxation to anandamide and tissue contents of the N-acylethanolamides were examined under myographic conditions. Anandamide-induced relaxation was potentiated by pretreatment with PEA (10 microM) or OEA (1 microM), or in combination. The potentiation by PEA and OEA was endothelium-independent and abolished by treatment with capsaicin (10 microM), which desensitizes the transient receptor potential vanilloid type 1 (TRPV1) receptor system, or by the TRPV1 receptor antagonist, N-(3-methoxyphenyl)-4-chlorocinnamide (SB366791) (2 microM). It was also observed at molar ratios of anandamide and PEA (or OEA) similar to those found in mesenteric arteries. PEA and inhibition of anandamide hydrolysis by 3'-carbamoyl-biphenyl-3-yl-cyclohexylcarbamate (URB597) (1 microM) additively potentiated anandamide responses. On the other hand, PEA and OEA also induced vasorelaxation per se (rank order of potency: anandamide>OEA>PEA), but relaxation to the three N-acylethanolamides displayed different sensitivity to treatment with capsaicin, SB366791 and URB597. For example, relaxations to anandamide and OEA, but not PEA, were attenuated by both capsaicin and SB366791. This study shows that PEA and OEA potentiate relaxant responses to anandamide through TRPV1 receptors in rat small mesenteric arteries. The congeners also induce vasorelaxation per se, suggesting a function for the N-acylethanolamides in vascular control.

  12. M33: A Close Neighbor Reveals its True Size and Splendor

    NASA Image and Video Library

    2009-04-03

    One of our closest galactic neighbors shows its awesome beauty in this new image from NASA Spitzer Space Telescope. M33, also known as the Triangulum Galaxy, is a member of what known as our Local Group of galaxies.

  13. M33: A Close Neighbor Reveals its True Size and Splendor 3-color composite

    NASA Image and Video Library

    2009-04-03

    One of our closest galactic neighbors shows its awesome beauty in this new image from NASA Spitzer Space Telescope. M33, also known as the Triangulum Galaxy, is a member of what known as our Local Group of galaxies.

  14. Finding beat Cepheids in M33 and their use in measuring the metallicity gradient

    NASA Astrophysics Data System (ADS)

    Short, Lawrence; Bersier, David

    2017-09-01

    The period ratio between the two different pulsation modes of beat Cepheids is directly affected by the metallicity of the star. Our aim is to find all of the beat Cepheids in M33 and determine their metallicities hence allowing us to derive the metallicity gradient. To achieve this we have M33 data from the INT and the CFHT variability survey conducted by Hartman et al. (2006, [1]).

  15. CHARACTERIZATION OF THE MOST LUMINOUS STAR IN M33: A SUPER SYMBIOTIC BINARY

    SciTech Connect

    Mikołajewska, Joanna; Iłkiewicz, Krystian; Caldwell, Nelson; Shara, Michael M.

    2015-01-30

    We present the first spectrum of the most luminous infrared star in M33, and use it to demonstrate that the object is almost certainly a binary composed of a massive O star and a dust-enshrouded red hypergiant. This is the most luminous symbiotic binary ever discovered. Its radial velocity is an excellent match to that of the hydrogen gas in the disk of M33, supporting our interpretation that it is a very young and massive binary star.

  16. VizieR Online Data Catalog: Deep XMM-Newton survey of M33 (Williams+, 2015)

    NASA Astrophysics Data System (ADS)

    Williams, B. F.; Wold, B.; Haberl, F.; Garofali, K.; Blair, W. P.; Gaetz, T. J.; Kuntz, K. D.; Long, K. S.; Pannuti, T. G.; Pietsch, W.; Plucinsky, P. P.; Winkler, P. F.

    2015-07-01

    To produce an M33 catalog, we have used data of several newly observed XMM-Newton fields in M33 and archival observations of an eighth field (PI: Pietsch; from 2010-01-07 to 2010-02-24). The observation dates for the seven new data fields ranged from 2010 July 09 to August 15 and from 2012 January 10 to January 12. (2 data files).

  17. AN UPDATED CATALOG OF M33 CLUSTERS AND CANDIDATES: UBVRI PHOTOMETRY AND SOME STATISTICAL RESULTS

    SciTech Connect

    Ma Jun

    2012-08-15

    We present UBVRI photometry for 392 star clusters and candidates in the field of M33, which are selected from the most recent star cluster catalog. In this catalog, the authors listed star clusters' parameters such as cluster positions, magnitudes, colors in the UBVRIJHK{sub s} filters, and so on. However, a large fraction of objects in this catalog do not have previously published photometry. Photometry is performed using archival images from the Local Group Galaxies Survey, which covers 0.8 deg{sup 2} along the major axis of M33. Detailed comparisons show that, in general, our photometry is consistent with previous measurements. Positions (right ascension and declination) for some clusters are corrected here. Combined with previous literature, ours constitute a large sample of M33 star clusters. Based on this cluster sample, we present some statistical results: none of the youngest M33 clusters ({approx}10{sup 7} yr) have masses approaching 10{sup 5} M{sub Sun} ; roughly half the star clusters are consistent with the 10{sup 4}-10{sup 5} M{sub Sun} mass models; the continuous distribution of star clusters along the model line indicates that M33 star clusters have been formed continuously from the epoch of the first star cluster formation until recent times; and there are {approx}50 star clusters which are overlapped with the Galactic globular clusters on the color-color diagram, and these clusters are old globular cluster candidates in M33.

  18. A naturally occurring GIP receptor variant undergoes enhanced agonist-induced desensitization, which impairs GIP control of adipose insulin sensitivity.

    PubMed

    Mohammad, Sameer; Patel, Rajesh T; Bruno, Joanne; Panhwar, Muhammad Siyab; Wen, Jennifer; McGraw, Timothy E

    2014-10-01

    Glucose-dependent insulinotropic polypeptide (GIP), an incretin hormone secreted from gastrointestinal K cells in response to food intake, has an important role in the control of whole-body metabolism. GIP signals through activation of the GIP receptor (GIPR), a G-protein-coupled receptor (GPCR). Dysregulation of this pathway has been implicated in the development of metabolic disease. Here we demonstrate that GIPR is constitutively trafficked between the plasma membrane and intracellular compartments of both GIP-stimulated and unstimulated adipocytes. GIP induces a downregulation of plasma membrane GIPR by slowing GIPR recycling without affecting internalization kinetics. This transient reduction in the expression of GIPR in the plasma membrane correlates with desensitization to the effects of GIP. A naturally occurring variant of GIPR (E354Q) associated with an increased incidence of insulin resistance, type 2 diabetes, and cardiovascular disease in humans responds to GIP stimulation with an exaggerated downregulation from the plasma membrane and a delayed recovery of GIP sensitivity following cessation of GIP stimulation. This perturbation in the desensitization-resensitization cycle of the GIPR variant, revealed in studies of cultured adipocytes, may contribute to the link of the E354Q variant to metabolic disease.

  19. T Cell Receptor-induced Activation and Apoptosis In Cycling Human T Cells Occur throughout the Cell Cycle

    PubMed Central

    Karas, Michael; Zaks, Tal Z.; JL, Liu; LeRoith, Derek

    1999-01-01

    Previous studies have found conflicting associations between susceptibility to activation-induced cell death and the cell cycle in T cells. However, most of the studies used potentially toxic pharmacological agents for cell cycle synchronization. A panel of human melanoma tumor-reactive T cell lines, a CD8+ HER-2/neu-reactive T cell clone, and the leukemic T cell line Jurkat were separated by centrifugal elutriation. Fractions enriched for the G0–G1, S, and G2–M phases of the cell cycle were assayed for T cell receptor-mediated activation as measured by intracellular Ca2+ flux, cytolytic recognition of tumor targets, and induction of Fas ligand mRNA. Susceptibility to apoptosis induced by recombinant Fas ligand and activation-induced cell death were also studied. None of the parameters studied was specific to a certain phase of the cell cycle, leading us to conclude that in nontransformed human T cells, both activation and apoptosis through T cell receptor activation can occur in all phases of the cell cycle. PMID:10588669

  20. The J-PLUS survey: understanding the formation and evolution of M 33

    NASA Astrophysics Data System (ADS)

    San Roman, I.; Marín-Franch, A.; Ederoclite, A.; Cenarro, A. J.; Vázquez-Ramió, H.; J-PLUS Team

    2015-05-01

    It is widely accepted that large disk galaxies derive from the merger and accretion of many smaller subsystems. However, it is less clear how low-mass spiral galaxies fit into this picture. The best way to answer this question is to study the nearest example of a dwarf spiral galaxy, M 33. We propose to perform a detailed photometric analysis of the resolved and unresolved stellar population of M 33 using data from the Javalambre Photometric Local Universe Survey (J-PLUS). Using a set of 12 broad-, intermediate- and narrow-band filters, J-PLUS will cover a wavelength range between 330-1000 nm, reaching magnitudes of r ˜ 22. We will take advantage of the IFU-like capabilities of the survey to determine the properties of the spatially resolved and unresolved components of the galaxy. In particular, we will perform a 2-D analysis of the underlying population as well as a detailed study of M 33 star cluster system. Spectral fitting diagnostics of the resolved and unresolved populations will allow us to determine ages, metallicities and masses of the galactic disk, spheroidal components and cluster system. We will analyze two regions covering a total area of 3.2 deg^{2}. One field will be centered on M 33 covering the disk and the outskirts. A second field will cover the line connecting M 33 with M 31 to map the stellar substructure surrounding M 33. This study will provide key insights into the star formation history of low-mass galaxies as well as place M 33 within the context of galaxy formation process.

  1. RR Lyrae variable stars in M31-M33 super-halo

    NASA Astrophysics Data System (ADS)

    Tanakul, Nahathai; Sarajedini, Ata

    2017-01-01

    RR Lyrae variable stars can serve as powerful probes of their host stellar populations. Information such as distance, metallicity, reddening, and age can be gleaned from their pulsation properties. Therefore, studying them in the nearest spiral galaxies M31 and M33 will yield important information about the early history of these galaxies. The main goals of this study are: 1) To investigate the Oosterhoff type of RR Lyrae stars in M31 and M33 and compare them with the Milky Way to better understand the formation of these galaxies. 2) To investigate the early formation history of these two galaxies through knowledge of their RR Lyrae stars. In order to achieve these goals, we have analyzed 10 fields in M31 and M33 (6 fields in M31 and 4 fields in M33) using archival imaging from the Hubble Space Telescope. Published data for M31, M33, and several M31 dwarf spheroidal galaxies are also used to study the global properties of RR Lyrae in these systems. The results are then compared with those in the Milky Way galaxy.

  2. RR Lyrae variables in M33: two new fields and an analysis of the galaxy's population

    NASA Astrophysics Data System (ADS)

    Tanakul, Nahathai; Yang, Soung-Chul; Sarajedini, Ata

    2017-06-01

    We present a re-analysis of M33 RR Lyrae variables in four different fields: two inner disc fields and two outer disc fields. These are located at 8.5, 8.7, 36 and 46 arcmin from the centre of M33, respectively. We identify 48 new RR Lyrae variable stars and refine the light-curve properties of 51 previously identified variables. From the light curves, we calculate reddenings and metallicities for each star. Using data in this paper and previously published material, we are able to construct a radial density profile for the RR Lyrae stars in M33. This profile, when plotted in log space, has a slope of ˜-2.0 ± 0.15 which agrees with the radial distribution of halo stars in the Milky Way and M31. This suggests that the majority of M33 RR Lyrae variables observed so far belong to the halo. We also examine the RR Lyrae specific frequency and absolute magnitude relation in M33 and find good agreement with previous studies.

  3. Imaging and spectroscopy of ionized shells in M33 and M31

    NASA Astrophysics Data System (ADS)

    Hunter, D. A.

    1994-11-01

    This paper extends an examination of the spectral signature of the interaction of massive stars with the surrounding interstellar medium to the nearby spiral galaxies M33 and M31. H-alpha images and low-dispersion spectra have been obtained for eight giant ionized shell structures in M33 and two in M31. These structures are believed to be the result of the encircled groups of stars blowing holes in the gas through winds and supernova explosions. The emission-line ratios are compared to those of giant and supergiant shells in the Large Magellanic Cloud (LMC). Generally, the shells in M33 and M31 follow the same trend lines outlined by the shells and H II regions in the LMC with the M31 shells being offset to higher metallicity. However, unlike shells in the LMC, the M33 shells have some emission-line ratios that are not particularly distinct from those of H II regions in the same galaxy. Nevertheless, like the shells in the LMC, the emission-line ratios imply that the emission from the shells in M33 and M31 is dominated by photoionization processes. Upper limits to (O I)/H-alpha are consistent with this in most cases.

  4. Monitoring pulsating giant stars in M33: star formation history and chemical enrichment

    NASA Astrophysics Data System (ADS)

    Javadi, A.; van Loon, J. Th

    2017-06-01

    We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope (UKIRT), of the Local Group spiral galaxy M33 (Triangulum). A new method has been developed by us to use pulsating giant stars to reconstruct the star formation history of galaxies over cosmological time as well as using them to map the dust production across their host galaxies. In first Instance the central square kiloparsec of M33 was monitored and long period variable stars (LPVs) were identified. We give evidence of two epochs of a star formation rate enhanced by a factor of a few. These stars are also important dust factories, we measure their dust production rates from a combination of our data with Spitzer Space Telescope mid-IR photometry. Then the monitoring survey was expanded to cover a much larger part of M33 including spiral arms. Here we present our methodology and describe results for the central square kiloparsec of M33 [1-4] and disc of M33 [5-8].

  5. THE M33 GLOBULAR CLUSTER SYSTEM WITH PAndAS DATA: THE LAST OUTER HALO CLUSTER?

    SciTech Connect

    Cockcroft, Robert; Harris, William E.; Ferguson, Annette M. N. E-mail: harris@physics.mcmaster.ca

    2011-04-01

    We use CFHT/MegaCam data to search for outer halo star clusters in M33 as part of the Pan-Andromeda Archaeological Survey. This work extends previous studies out to a projected radius of 50 kpc and covers over 40 deg{sup 2}. We find only one new unambiguous star cluster in addition to the five previously known in the M33 outer halo (10 kpc {<=} r {<=} 50 kpc). Although we identify 2440 cluster candidates of various degrees of confidence from our objective image search procedure, almost all of these are likely background contaminants, mostly faint unresolved galaxies. We measure the luminosity, color, and structural parameters of the new cluster in addition to the five previously known outer halo clusters. At a projected radius of 22 kpc, the new cluster is slightly smaller, fainter, and redder than all but one of the other outer halo clusters, and has g' {approx} 19.9, (g' - i') {approx} 0.6, concentration parameter c {approx} 1.0, a core radius r{sub c} {approx} 3.5 pc, and a half-light radius r{sub h} {approx} 5.5 pc. For M33 to have so few outer halo clusters compared to M31 suggests either tidal stripping of M33's outer halo clusters by M31, or a very different, much calmer accretion history of M33.

  6. The M33 Globular Cluster System with PAndAS Data: the Last Outer Halo Cluster?

    NASA Astrophysics Data System (ADS)

    Cockcroft, Robert; Harris, William E.; Ferguson, Annette M. N.; Huxor, Avon; Ibata, Rodrigo; Irwin, Mike J.; McConnachie, Alan W.; Woodley, Kristin A.; Chapman, Scott C.; Lewis, Geraint F.; Puzia, Thomas H.

    2011-04-01

    We use CFHT/MegaCam data to search for outer halo star clusters in M33 as part of the Pan-Andromeda Archaeological Survey. This work extends previous studies out to a projected radius of 50 kpc and covers over 40 deg2. We find only one new unambiguous star cluster in addition to the five previously known in the M33 outer halo (10 kpc <= r <= 50 kpc). Although we identify 2440 cluster candidates of various degrees of confidence from our objective image search procedure, almost all of these are likely background contaminants, mostly faint unresolved galaxies. We measure the luminosity, color, and structural parameters of the new cluster in addition to the five previously known outer halo clusters. At a projected radius of 22 kpc, the new cluster is slightly smaller, fainter, and redder than all but one of the other outer halo clusters, and has g' ≈ 19.9, (g' - i') ≈ 0.6, concentration parameter c ≈ 1.0, a core radius rc ≈ 3.5 pc, and a half-light radius rh ≈ 5.5 pc. For M33 to have so few outer halo clusters compared to M31 suggests either tidal stripping of M33's outer halo clusters by M31, or a very different, much calmer accretion history of M33.

  7. The X-ray Source Population of M33 as seen by XMM-Newton

    NASA Astrophysics Data System (ADS)

    Garofali, Kristen; Williams, Benjamin F.; Wold, Brian; Haberl, Frank; Blair, William P.; Gaetz, Terrance J.; Kuntz, K. D.; Long, Knox S.; Pannuti, Thomas; Pietsch, Wolfgang; Plucinsky, Paul P.; Winkler, P. Frank

    2015-01-01

    We present results from the deepest survey of M33 with XMM-Newton to date. The survey consists of 8 overlapping EPIC fields covering an area beyond the D25 isophote down to a limiting sensitivity of L(0.2-4.5 keV) > 4e+34 erg/s. This larger field of view coupled with the higher soft sensitivity of XMM-Newton provides an excellent complement to the Chandra ACIS Survey of M33 (ChASeM33). Comparison of our source catalog with the Chandra survey allows us to identify variable sources as well as previously undetected soft sources. Our coverage of the full M33 disk reveals many new sources including SNRs previously undetected in X-rays. The radial coverage extends far enough to provide high-quality background statistics, including a radial density distribution of bright sources which suggests that roughly 15% of sources with L > 3.6e+35 erg/s are likely to be associated with M33. The accurate background statistics allow us to perform a simultaneous fit of our background and observed luminosity functions, which yields a slope consistent with the presence of a significant population of HMXBs. The combined XMM-Newton and Chandra data will allow the most detailed study of the X-ray population of a late-type spiral possible with currently-available facilities. We will show preliminary work in studying new HMXB candidates using HST.

  8. Search for the γ-ray emission from M33 with the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Fu, L.; Xia, Z. Q.; Shen, Z. Q.

    2017-10-01

    We searched for the γ-ray signal from M33, one of the largest galaxies in the Local Group, using the Pass8 data from the Fermi Large Area Telescope (LAT). No statistically significant γ-ray emission has been detected in the direction of M33, and we report a new upper limit of the high-energy ( > 100 MeV) photon flux of 2.3 × 10- 9 ph cm- 2 s- 1, which is stricter than previous constraints and implies a cosmic ray density for M33 that is lower than that suggested previously. The current limit is still, however, in agreement with the correlation of star formation rate and γ-ray luminosity inferred from the Local group galaxies and a few nearby starburst galaxies.

  9. The X-ray Source Population of M33 as seen by XMM-Newton

    NASA Astrophysics Data System (ADS)

    Garofali, Kristen

    2014-08-01

    We present results from a deep XMM-Newton survey of M33 consisting of 8 pointings extending beyond the D25 isophote sensitive to L(0.2-4.5 keV) > 4e+34 erg/s. The large area coupled with the XMM soft response complement the deep Chandra Survey of M33. Cross-correlation of the surveys allows us to identify variable sources and previously undetected soft sources. Our coverage reveals many new sources including at least one previously unclassified SNR. The radial coverage provides high-quality background statistics, including a radial density distribution of sources that suggests roughly 15% (~60) of sources with inferred L > 3.6e+35 erg/s are in M33. Our background-corrected log(N)--log(S) reveals a relatively flat power law index (0.3-0.7) consistent with a substantial population of HMXBs.

  10. M33: A Close Neighbor Reveals its True Size and Splendor (3-color composite)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    One of our closest galactic neighbors shows its awesome beauty in this new image from NASA's Spitzer Space Telescope. M33, also known as the Triangulum Galaxy, is a member of what's known as our Local Group of galaxies. Along with our own Milky Way, this group travels together in the universe, as they are gravitationally bound. In fact, M33 is one of the few galaxies that is moving toward the Milky Way despite the fact that space itself is expanding, causing most galaxies in the universe to grow farther and farther apart.

    When viewed with Spitzer's infrared eyes, this elegant spiral galaxy sparkles with color and detail. Stars appear as glistening blue gems (several of which are actually foreground stars in our own galaxy), while dust rich in organic molecules glows green. The diffuse orange-red glowing areas indicate star-forming regions, while small red flecks outside the spiral disk of M33 are most likely distant background galaxies. But not only is this new image beautiful, it also shows M33 to be surprising large bigger than its visible-light appearance would suggest. With its ability to detect cold, dark dust, Spitzer can see emission from cooler material well beyond the visible range of M33's disk. Exactly how this cold material moved outward from the galaxy is still a mystery, but winds from giant stars or supernovas may be responsible.

    M33 is located about 2.9 million light-years away in the constellation Triangulum. This is a three-color composite image showing infrared observations from two of Spitzer instruments. Blue represents combined 3.6- and 4.5-micron light and green shows light of 8 microns, both captured by Spitzer's infrared array camera. Red is 24-micron light detected by Spitzer's multiband imaging photometer.

  11. M33: A Close Neighbor Reveals its True Size and Splendor (3-color composite)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    One of our closest galactic neighbors shows its awesome beauty in this new image from NASA's Spitzer Space Telescope. M33, also known as the Triangulum Galaxy, is a member of what's known as our Local Group of galaxies. Along with our own Milky Way, this group travels together in the universe, as they are gravitationally bound. In fact, M33 is one of the few galaxies that is moving toward the Milky Way despite the fact that space itself is expanding, causing most galaxies in the universe to grow farther and farther apart.

    When viewed with Spitzer's infrared eyes, this elegant spiral galaxy sparkles with color and detail. Stars appear as glistening blue gems (several of which are actually foreground stars in our own galaxy), while dust rich in organic molecules glows green. The diffuse orange-red glowing areas indicate star-forming regions, while small red flecks outside the spiral disk of M33 are most likely distant background galaxies. But not only is this new image beautiful, it also shows M33 to be surprising large bigger than its visible-light appearance would suggest. With its ability to detect cold, dark dust, Spitzer can see emission from cooler material well beyond the visible range of M33's disk. Exactly how this cold material moved outward from the galaxy is still a mystery, but winds from giant stars or supernovas may be responsible.

    M33 is located about 2.9 million light-years away in the constellation Triangulum. This is a three-color composite image showing infrared observations from two of Spitzer instruments. Blue represents combined 3.6- and 4.5-micron light and green shows light of 8 microns, both captured by Spitzer's infrared array camera. Red is 24-micron light detected by Spitzer's multiband imaging photometer.

  12. Gas and dust cooling along the major axis of M 33 (HerM33es). ISO/LWS [C ii] observations

    NASA Astrophysics Data System (ADS)

    Kramer, C.; Abreu-Vicente, J.; García-Burillo, S.; Relaño, M.; Aalto, S.; Boquien, M.; Braine, J.; Buchbender, C.; Gratier, P.; Israel, F. P.; Nikola, T.; Röllig, M.; Verley, S.; van der Werf, P.; Xilouris, E. M.

    2013-05-01

    Aims: We aim to better understand the heating of gas by observing the prominent gas cooling line [C ii] at 158 μm in the low-metallicity environment of the Local Group spiral galaxy M 33 on scales of 280 pc. In particular, we describe the variation of the photoelectric heating efficiency with the galactic environment. Methods: In this study, we present [C ii] observations along the major axis of M 33 using the Infrared Space Observatory in combination with Herschel continuum maps, IRAM 30 m CO 2-1, and VLA H i data to study the variation in velocity integrated intensities. The ratio of [C ii] emission over the far-infrared continuum is used as a proxy for the heating efficiency, and models of photon-dominated regions are used to study the local physical densities, far-ultraviolet radiation fields, and average column densities of the molecular clouds. Results: The heating efficiency stays constant at 0.8% in the inner 4.5 kpc radius of the galaxy, where it increases to reach values of ~3% in the outskirts at about a 6 kpc radial distance. The rise of efficiency is explained in the framework of PDR models by lowered volume densities and FUV fields for optical extinctions of only a few magnitudes at constant metallicity. For the significant fraction of H i emission stemming from PDRs and for typical pressures found in the Galactic cold neutral medium (CNM) traced by H i emission, the CNM contributes ~15% to the observed [C ii] emission in the inner 2 kpc radius of M 33. The CNM contribution remains largely undetermined in the south, while positions between radial distances of 2 and 7.3 kpc in the north of M 33 show a contribution of ~40% ± 20%. Herschel is an ESA space observatory with science instruments provided by European-led PrincipalInvestigator consortia and with important participation from NASA.Appendices are available in electronic form at http://www.aanda.org

  13. Flat-spectrum radio source C1 in M33 is a background radio galaxy

    SciTech Connect

    Reynolds, S.P.; Fix, J.D.

    1988-10-01

    A candidate Crab-like supernova remnant in M33 discovered in a high-resolution survey of compact radio sources (Reynolds and Fix, 1987) has been observed. VLA observations at 1465 and 4885 MHz show that it is simply the flat-spectrum core of a completely normal double-lobed radio galaxy. This eliminates the last candidate Crab-like object in M33 whose size and brightness do not at all resemble those of the Crab Nebula, and confirms the dearth of Crab-like supernova remnants reported earlier. 7 references.

  14. VizieR Online Data Catalog: The M33 synoptic stellar survey. I. (Pellerin+, 2011)

    NASA Astrophysics Data System (ADS)

    Pellerin, A.; Macri, L. M.

    2011-05-01

    The DIRECT project obtained BVI observations of M33 over ~200 nights between 1996 September and 1999 November. Most of the survey was carried out at the F.L. Whipple Observatory (FLWO) 1.2m telescope on Mount Hopkins, Arizona, with additional images obtained at the Michigan-Dartmouth-MIT 1.3m telescope on Kitt Peak, Arizona. The project observed 11 different fields, each 11.5'x11.5' in size, which covered most of the M33 disk (see Figure 1). We collected additional images at the WIYN 3.5m telescope between 2002 August and 2006 December. (5 data files).

  15. Tyrosine phosphorylation of the BRI1 receptor kinase occurs via a posttranslational modification and is activated by the juxtamembrane domain

    USDA-ARS?s Scientific Manuscript database

    In metazoans, receptor kinases control many essential processes related to growth and development and response to the environment. The receptor kinases in plants and animals are structurally similar but evolutionarily distinct from one another, and thus while most animal receptor kinases are tyrosin...

  16. Endocytosis and ligand dissociation and degradation mediated by the hepatic galactosyl receptor occur via two different pathways

    SciTech Connect

    Weigel, P.H.; Clarke, B.L.; Oka, J.A.

    1986-05-01

    Isolated rat hepatocytes express two distinct populations of surface Galactosyl receptor activity, measured by the binding of /sup 125/I-asialo-orosomucoid (ASOR), which they designate State 1 and State 2. Freshly isolated cells express only state 1 receptors. Cells equilibrated at 37/sup 0/C also express State 2 receptors, which represent 50-80% of the total surface activity. In the absence of ligand, State 2 receptor activity is reversibly decreased by metabolic energy poisons, low temperature and microtubule drugs, whereas State 1 receptor activity is unaffected. Endocytosis of /sup 125/I-ASOR by State 1 receptors is followed by a slow dissociation of /sup 125/I-ASOR from receptor but the immediate release of acid soluble degradation products. In contrast, State 2 receptors mediate endocytosis which involves a rapid dissociation step but a 20 min lag, prior to the release of degradation products. Both pathways follow first order kinetics and are functional under steady state conditions indicating coordinated receptor recycling. Degradation mediated by both pathways is inhibited by leupeptin and chloroquine. The State 1 and 2 pathways can be further differentiated by the greater sensitivity of the latter to microtubule drugs. These results suggest that there are either structurally different native receptors or that identical receptors are directed into two different functional pathways, for example by interaction with different types of coated pits.

  17. Discrete clouds of neutral gas between the galaxies M31 and M33.

    PubMed

    Wolfe, Spencer A; Pisano, D J; Lockman, Felix J; McGaugh, Stacy S; Shaya, Edward J

    2013-05-09

    Spiral galaxies must acquire gas to maintain their observed level of star formation beyond the next few billion years. A source of this material may be the gas that resides between galaxies, but our understanding of the state and distribution of this gas is incomplete. Radio observations of the Local Group of galaxies have revealed hydrogen gas extending from the disk of the galaxy M31 at least halfway to M33. This feature has been interpreted to be the neutral component of a condensing intergalactic filament, which would be able to fuel star formation in M31 and M33, but simulations suggest that such a feature could also result from an interaction between both galaxies within the past few billion years (ref. 5). Here we report radio observations showing that about 50 per cent of this gas is composed of clouds, with the rest distributed in an extended, diffuse component. The clouds have velocities comparable to those of M31 and M33, and have properties suggesting that they are unrelated to other Local Group objects. We conclude that the clouds are likely to be transient condensations of gas embedded in an intergalactic filament and are therefore a potential source of fuel for future star formation in M31 and M33.

  18. Aerodynamic Analysis of the M33 Projectile Using the CFX Code

    DTIC Science & Technology

    2011-12-01

    OF THE M33 PROJECTILE USING THE CFX CODE by Wong, Chee Heng December 2011 Thesis Advisor: Max F. Platzer Second Reader: Anthony...2011 Author: Wong Chee Heng Approved by: Maximilian F. Platzer Thesis Advisor Anthony Gannon Second Reader Knox T...It is my greatest delight to acknowledge the dedicated guidance and support rendered by my thesis advisor, Professor Maximilian F. Platzer . His

  19. M33: A Close Neighbor Reveals its True Size and Splendor

    NASA Technical Reports Server (NTRS)

    2009-01-01

    One of our closest galactic neighbors shows its awesome beauty in this new image from NASA's Spitzer Space Telescope. M33, also known as the Triangulum Galaxy, is a member of what's known as our Local Group of galaxies. Along with our own Milky Way, this group travels together in the universe, as they are gravitationally bound. In fact, M33 is one of the few galaxies that is moving toward the Milky Way despite the fact that space itself is expanding, causing most galaxies in the universe to grow farther and farther apart.

    When viewed with Spitzer's infrared eyes, this elegant spiral galaxy sparkles with color and detail. Stars appear as glistening blue gems (many of which are actually foreground stars in our own galaxy), while dust in the spiral disk of the galaxy glows pink and red. But not only is this new image beautiful, it also shows M33 to be surprising large bigger than its visible-light appearance would suggest. With its ability to detect cold, dark dust, Spitzer can see emission from cooler material well beyond the visible range of M33's disk. Exactly how this cold material moved outward from the galaxy is still a mystery, but winds from giant stars or supernovas may be responsible.

    M33 is located about 2.9 million light-years away in the constellation Triangulum. This composite image was taken by Spitzer's infrared array camera. The color blue indicates infrared light of 3.6 microns, green shows 4.5-micron light, and red 8.0 microns.

  20. M33: A Close Neighbor Reveals its True Size and Splendor

    NASA Technical Reports Server (NTRS)

    2009-01-01

    One of our closest galactic neighbors shows its awesome beauty in this new image from NASA's Spitzer Space Telescope. M33, also known as the Triangulum Galaxy, is a member of what's known as our Local Group of galaxies. Along with our own Milky Way, this group travels together in the universe, as they are gravitationally bound. In fact, M33 is one of the few galaxies that is moving toward the Milky Way despite the fact that space itself is expanding, causing most galaxies in the universe to grow farther and farther apart.

    When viewed with Spitzer's infrared eyes, this elegant spiral galaxy sparkles with color and detail. Stars appear as glistening blue gems (many of which are actually foreground stars in our own galaxy), while dust in the spiral disk of the galaxy glows pink and red. But not only is this new image beautiful, it also shows M33 to be surprising large bigger than its visible-light appearance would suggest. With its ability to detect cold, dark dust, Spitzer can see emission from cooler material well beyond the visible range of M33's disk. Exactly how this cold material moved outward from the galaxy is still a mystery, but winds from giant stars or supernovas may be responsible.

    M33 is located about 2.9 million light-years away in the constellation Triangulum. This composite image was taken by Spitzer's infrared array camera. The color blue indicates infrared light of 3.6 microns, green shows 4.5-micron light, and red 8.0 microns.

  1. The Herschel M 33 extended survey (HerM33es): PACS spectroscopy of the star-forming region BCLMP 302

    NASA Astrophysics Data System (ADS)

    Mookerjea, B.; Kramer, C.; Buchbender, C.; Boquien, M.; Verley, S.; Relaño, M.; Quintana-Lacaci, G.; Aalto, S.; Braine, J.; Calzetti, D.; Combes, F.; Garcia-Burillo, S.; Gratier, P.; Henkel, C.; Israel, F.; Lord, , S.; Nikola, T.; Röllig, M.; Stacey, G.; Tabatabaei, F. S.; van der Tak, F.; van der Werf, P.

    2011-08-01

    Context. The emission line of [C ii] at 158 μm is one of the strongest cooling lines of the interstellar medium (ISM) in galaxies. Aims: Distinguishing the relative contributions of the different ISM phases to [C ii] emission is a major objective of the HerM33es program, a Herschel key project to study the ISM in the nearby spiral galaxy M 33. Methods: Using PACS, we have mapped the emission of [C ii] 158 μm, [O i] 63 μm, and other FIR lines in a 2' × 2' region of the northern spiral arm of M 33, centered on the H ii region BCLMP 302. At the peak of Hα emission, we observed in addition a velocity-resolved [C ii] spectrum using HIFI. We use scatterplots to compare these data with PACS 160 μm continuum maps, and with maps of CO and H i data, at a common resolution of 12″ or 50 pc. Maps of Hα and 24 μm emission observed with Spitzer are used to estimate the SFR. We created maps of the [C ii] and [O i] 63 μm emission and detected [N ii] 122 μm and [N iii] 57 μm at individual positions. Results: The [C ii] line observed with HIFI is significantly broader than that of CO, and slightly blue-shifted. In addition, there is little spatial correlation between [C ii] observed with PACS and CO over the mapped region. There is even less spatial correlation between [C ii] and the atomic gas traced by H i. Detailed comparison of the observed intensities towards the H ii region with models of photo-ionization and photon-dominated regions, confirms that a significant fraction, 20-30%, of the observed [C ii] emission stems from the ionized gas and not from the molecular cloud. The gas heating efficiency, using the ratio of [C ii] to the TIR as a proxy, varies between 0.07 and 1.5%, with the largest variations found outside the H ii region. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  2. A detailed view of a molecular cloud in the far outer disk of M 33. Molecular cloud formation in M 33

    NASA Astrophysics Data System (ADS)

    Braine, J.; Gratier, P.; Contreras, Y.; Schuster, K. F.; Brouillet, N.

    2012-12-01

    The amount of H2 present in spiral galaxies remains uncertain, particularly in the dim outer regions and in low-metallicity environments. We present high-resolution CO(1-0) observations with the Plateau de Bure interferometer of the most distant molecular cloud in the local group galaxy M 33. The cloud is a single entity rather than a set of smaller clouds within the broad beam of the original single-dish observations. The interferometer and single-dish fluxes are very similar and the line widths are indistinguishable, despite the difference in beamsize. At a spatial resolution of 10 pc, beyond the optical radius of the M 33, the CO brightness temperature reaches 2.4 Kelvins. A virial mass estimate for the cloud yields a mass of 4.3 × 104 M⊙ and a ratio N(H2)/ICO(1-0) ≃ 3.5 × 1020 cm-2/(K km s-1). While no velocity gradient is seen where the emission is strong, the velocity is redshifted to the extreme SW and blue-shifted to the far NE. If the orientation of the cloud is along the plane of the disk (i.e. not perpendicular), then these velocities correspond to slow infall or accretion. The rather modest infall rate would be about 2 × 10-4 M⊙ yr-1. Based on observations carried out with the IRAM Plateau de Bure Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).Data cube in FITS files is only available 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/548/A52

  3. The formation and evolution of M33 as revealed by its star clusters

    NASA Astrophysics Data System (ADS)

    San Roman, Izaskun

    2012-03-01

    Numerical simulations based on the Lambda-Cold Dark Matter (Λ-CDM) model predict a scenario consistent with observational evidence in terms of the build-up of Milky Way-like halos. Under this scenario, large disk galaxies derive from the merger and accretion of many smaller subsystems. However, it is less clear how low-mass spiral galaxies fit into this picture. The best way to answer this question is to study the nearest example of a dwarf spiral galaxy, M33. We will use star clusters to understand the structure, kinematics and stellar populations of this galaxy. Star clusters provide a unique and powerful tool for studying the star formation histories of galaxies. In particular, the ages and metallicities of star clusters bear the imprint of the galaxy formation process. We have made use of the star clusters to uncover the formation and evolution of M33. In this dissertation, we have carried out a comprehensive study of the M33 star cluster system, including deep photometry as well as high signal-to-noise spectroscopy. In order to mitigate the significant incompleteness presents in previous catalogs, we have conducted ground-based and space-based photometric surveys of M33 star clusters. Using archival images, we have analyzed 12 fields using the Advanced Camera for Surveys Wide Field Channel onboard the Hubble Space Telescope (ACS/HST) along the major axis of the galaxy. We present integrated photometry and color-magnitude diagrams for 161 star clusters in M33, of which 115 were previously uncataloged. This survey extends the depth of the existing M33 cluster catalogs by ˜ 1 mag. We have expanded our search through a photometric survey in a 1° x 1° area centered on M33 using the MegaCam camera on the 3.6m Canada-France-Hawaii Telescope (CFHT). In this work we discuss the photometric properties of the sample, including color-color diagrams of 599 new candidate stellar clusters, and 204 confirmed clusters. Comparisons with models of simple stellar populations

  4. Naturally occurring amino acid substitutions at Arg1174 in the human insulin receptor result in differential effects on receptor biosynthesis and hybrid formation, leading to discordant clinical phenotypes.

    PubMed

    Rau, H; Kocova, M; O'Rahilly, S; Whitehead, J P

    2000-07-01

    Missense mutations in the tyrosine kinase domain of the human insulin receptor frequently result in a dominantly inherited form of insulin resistance. We noted a marked disparity in the clinical phenotypes of our study subjects with different missense mutations at the same residue (Arg1174) of the insulin receptor. Subjects with a tryptophan substitution (W) were only moderately hyperinsulinemic, whereas those with a glutamine substitution (Q) had severe clinical and biochemical insulin resistance. Studies were undertaken to explore the molecular mechanisms underlying these differences. Both W and Q mutant receptors bound insulin normally but were kinase inactive. The W mutation resulted in more rapid degradation of newly synthesized mutant receptor, which contrasted with the near-normal biosynthesis of the Q receptor. The propensity of the W receptor to form hybrids with the cotransfected wild-type (WT) receptor was also markedly impaired compared with the Q receptor, to an extent greater than could be explained by lower steady-state expression. Thus, the more clinically benign consequences of the heterozygous W mutant receptor are likely to relate to its impaired biosynthesis and/or reduced capacity to form hybrids with WT receptors. In addition to providing an explanation for the milder phenotype of 1174W versus 1174Q carriers, these studies provide further support for the notion that the dominant-negative effect of insulin receptor tyrosine kinase mutations involves the competition between inactive mutant homodimers and WT/mutant hybrids with active WT homodimers for both ligands and intracellular substrates.

  5. Microarcsecond proper motions of extragalactic water vapor masers in M33

    NASA Technical Reports Server (NTRS)

    Greenhill, L. J.; Moran, J. M.; Reid, M. J.; Menten, K. M.; Hirabayashi, H.

    1993-01-01

    A second-epoch spectral line VLBI synthesis map of the H2O maser associated with the H II region IC 133 in the galaxy M33 is presented. Thirty-two spatially distinct maser features were identified, and a second center of maser activity within the IC 133 complex, IC 133 West, which is displaced about 0.3 arcsec from IC 133 Main, was discovered. A comparison of the two available maps of IC 133 is used to estimate the right ascension components of proper motion over a period of 479 d for five maser features to accuracies of between 7 and 16 micro-as. The dispersions in transverse and radial velocities for the maser features are consistent with the accepted distance to M33 of 720 kpc, where the data admit a fractional uncertainty in distance of 50 percent.

  6. Multi-Epoch Photometry of Luminous Stars in M31 and M33

    NASA Astrophysics Data System (ADS)

    Martin, John C.; Humphreys, Roberta M.

    2017-06-01

    Typically, the characteristics of supernovae and supernovae impostor progenitors are pieced together post-hoc from disparate sources after the event. Regular monitoring of luminous stars in nearby galaxies provides a more detailed and uniform source of information about those stars leading up to a significant event.We present Johnson/Cousins BVRI photometry from the first four years (2012 - 2016) of a targeted ground-based monitoring campaign of luminous stars in M31 and M33 including: likely supernovae and supernovae impostor progenitors, luminous infrared sources, classical LBVs, and warm and cool hypergiants. We have constructed a pipeline capable of quickly mining our images for photometry of additional targets.The survey will continue to image most of M31 and M33 on an annual basis for the foreseeable future.

  7. Point and Condensed Hα Sources in the Interior of M33

    NASA Astrophysics Data System (ADS)

    Moody, J. Ward; Hintz, Eric G.; Roming, Peter; Joner, Michael D.; Bucklein, Brian

    2017-01-01

    A variety of interesting objects such as Wolf-Rayet stars, tight OB associations, planetary nebula, x-ray binaries, etc. can be discovered as point or condensed sources in Hα surveys. How these objects distribute through a galaxy sheds light on the galaxy star formation rate and history, mass distribution, and dynamics. The nearby galaxy M33 is an excellent place to study the distribution of Hα-bright point sources in a flocculant spiral galaxy. We have reprocessed an archived WIYN continuum-subtracted Hα image of the inner 6.5' of the nearby galaxy M33 and, employing both eye and machine searches, have tabulated sources with a flux greater than 1 x 10-15 erg cm-2sec-1. We have identified 152 unresolved point sources and 122 marginally resolved condensed sources, 38 of which have not been previously cataloged. We present a map of these sources and discuss their probable identifications.

  8. The molecular hydrogen content of NGC 604 and other M33 H II region complexes

    NASA Astrophysics Data System (ADS)

    Israel, F. P.; Hawarden, T. G.; Geballe, T. R.; Wade, R.

    1990-02-01

    Six bright H II regions in M33 have been searched for H2 line emission. Previously detected fluorescent H2 emission in the first-ranked M33 H II region, NGC 604, has been mapped, making it possible to estimate the mass of its molecular cloud (of order 3 x 10 to the 6th solar masses). This result implies a ratio I(CO)/N(H2) lower by an order of magnitude than that of galactic molecular clouds. The lack of shocked H2 in NGC 604 implies that the ionized stellar-wind bubbles seen in the nebula are not interacting strongly with the molecular material. The dynamics of NGC 604 appear to be dominated by gravitational interaction.

  9. Spectroscopy of luminous blue stars in M31 and M33

    SciTech Connect

    Humphreys, R.M.; Massey, P.; Freedman, W.L. Kitt Peak National Observatory, Tucson, AZ Mount Wilson and Las Campanas Observatories, Pasadena, CA )

    1990-01-01

    Spectra have been obtained for classification of 42 candidate supergiants and 12 probable OB stars in M31 and eight early-type stars in M33. Twenty-six of those in M31 and six in M33 are confirmed as apparent single members with spectral types ranging from O8 to F8. Their interstellar extinction and luminosities are derived from published photographic and CCD photometry for all of the confirmed members. The preliminary and still incomplete HR diagram obtained for M31 shows an apparent lack of the most massive stars, stars with initial masses greater than 60 solar masses. The effects of incompleteness and observational selection on the interpretation of this HR diagram are discussed. 42 refs.

  10. Microarcsecond proper motions of extragalactic water vapor masers in M33

    NASA Technical Reports Server (NTRS)

    Greenhill, L. J.; Moran, J. M.; Reid, M. J.; Menten, K. M.; Hirabayashi, H.

    1993-01-01

    A second-epoch spectral line VLBI synthesis map of the H2O maser associated with the H II region IC 133 in the galaxy M33 is presented. Thirty-two spatially distinct maser features were identified, and a second center of maser activity within the IC 133 complex, IC 133 West, which is displaced about 0.3 arcsec from IC 133 Main, was discovered. A comparison of the two available maps of IC 133 is used to estimate the right ascension components of proper motion over a period of 479 d for five maser features to accuracies of between 7 and 16 micro-as. The dispersions in transverse and radial velocities for the maser features are consistent with the accepted distance to M33 of 720 kpc, where the data admit a fractional uncertainty in distance of 50 percent.

  11. Multi-epoch BVRI Photometry of Luminous Stars in M31 and M33

    NASA Astrophysics Data System (ADS)

    Martin, John C.; Humphreys, Roberta M.; pre="(">Minnesota Luminous Stars In Nearby Galaxies,

    2017-09-01

    We present the first four years of BVRI photometry from an on-going survey to annually monitor the photometric behavior of evolved luminous stars in M31 and M33. Photometry was measured for 199 stars at multiple epochs, including 9 classic Luminous Blue Variables (LBVs), 22 LBV candidates, 10 post-RGB A/F type hypergiants, and 18 B[e] supergiants. At all epochs, the brightness is measured in the V-band and at least one other band to a precision of 0.04-0.10 mag down to a limiting magnitude of 19.0-19.5. Thirty three stars in our survey exhibit significant variability, including at least two classic LBVs caught in S Doradus-type outbursts. A hyperlinked version of the photometry catalog is at http://go.uis.edu/m31m33photcat.

  12. The Early Spectral Evolution of the Classical Nova ASASSN-15th in M33

    NASA Astrophysics Data System (ADS)

    Wagner, R. Mark; Neric, Marko; Darnley, Matt J.; Williams, Steven; Starrfield, Sumner; Woodward, Charles E.; Prieto, Jose Luis

    2016-06-01

    During the course of the All Sky Automated Survey for SuperNovae (ASAS-SN) a new transient source designated ASASSN-15th was identified on images of the nearby galaxy M33 obtained with the 14 cm Brutus telescope in Haleakala, Hawaii on 2015 Dec 1.4 UT at V ~ 16.5 mag. Given the location of the transient in M33 and its apparent V magnitude at discovery, the implied absolute visual magnitude was about -8.5 mag suggesting that the transient was a new classical nova outburst in M33. Optical spectroscopy obtained by us on 2015 Dec 2.3 showed broad emission lines of Balmer, Fe II, and Na I D with P Cygni-type line profiles superposed on a blue continuum. The spectrum was consistent with a Fe II-type classical nova in M33 discovered early in the outburst. Subsequent spectra obtained by us on 2015 Dec 10.9 UT showed significant evolution since our first spectrum in that the deep P Cygni-type line profiles seen earlier were now extremely shallow or had almost completely disappeared with the emission component growing in strength. Additional emission lines from O I, Si II, and possibly He I were also present. We obtained optical spectroscopy of ASASSN-15th on 17 epochs between 2015 Dec 1 and 2016 Feb 11 UT with the 2.4 m Hiltner telescope (+OSMOS) of the MDM Observatory, the 2 m fully robotic Liverpool Telescope (+SPRAT), and the 2 x 8.4 m Large Binocular Telescope (+MODS). We will present our spectroscopy and discuss the early evolution of ASASSN-15th in the context of Galactic Fe II-class novae.

  13. A NEW DISTANCE TO M33 USING BLUE SUPERGIANTS AND THE FGLR METHOD

    SciTech Connect

    U, Vivian; Urbaneja, Miguel A.; Kudritzki, Rolf-Peter; Jacobs, Bradley A.; Bresolin, Fabio; Przybilla, Norbert E-mail: urbaneja@ifa.hawaii.ed E-mail: bjacobs@ifa.hawaii.ed E-mail: przybilla@sternwarte.uni-erlangen.d

    2009-10-20

    The quantitative spectral analysis of medium resolution optical spectra of A and B supergiants obtained with DEIMOS and ESI at the Keck Telescopes is used to determine a distance modulus of 24.93 +- 0.11 mag (968 +- 50 kpc) for the Triangulum Galaxy M33. The analysis yields stellar effective temperatures, gravities, interstellar reddening, and extinction, the combination of which provides a distance estimate via the flux-weighted gravity-luminosity relationship (FGLR). This result is based on an FGLR calibration that is continually being polished. An average reddening of (E(B - V)) approx 0.08 mag is found, with a large variation ranging from 0.01 to 0.16 mag, however, demonstrating the importance of accurate individual reddening measurements for stellar distance indicators in galaxies with evident signatures of interstellar absorption. The large-distance modulus found is in good agreement with recent work on eclipsing binaries, planetary nebulae, long-period variables, RR Lyrae stars, and also with Hubble Space Telescope (HST) observations of Cepheids, if reasonable reddening assumptions are made for the Cepheids. Since distances based on the tip of the red giant branch (TRGB) method found in the literature give conflicting results, we have used HST Advanced Camera for Surveys V- and I-band images of outer regions of M33 to determine a TRGB distance of 24.84 +- 0.10 mag, in basic agreement with the FGLR result. We have also determined stellar metallicities and discussed the metallicity gradient in the disk of M33. We find metallicity of Z {sub sun} at the center and 0.3 Z {sub sun} in the outskirts at a distance of one isophotal radius. The average logarithmic metallicity gradient is -0.07 +- 0.01 dex kpc{sup -1}. However, there is a large scatter around this average value, very similar to what has been found for the H II regions in M33.

  14. STAR CLUSTERS IN M33: UPDATED UBVRI PHOTOMETRY, AGES, METALLICITIES, AND MASSES

    SciTech Connect

    Fan, Zhou; De Grijs, Richard E-mail: grijs@pku.edu.cn

    2014-04-01

    The photometric characterization of M33 star clusters is far from complete. In this paper, we present homogeneous UBVRI photometry of 708 star clusters and cluster candidates in M33 based on archival images from the Local Group Galaxies Survey, which covers 0.8 deg{sup 2} along the galaxy's major axis. Our photometry includes 387, 563, 616, 580, and 478 objects in the UBVRI bands, respectively, of which 276, 405, 430, 457, and 363 do not have previously published UBVRI photometry. Our photometry is consistent with previous measurements (where available) in all filters. We adopted Sloan Digital Sky Survey ugriz photometry for complementary purposes, as well as Two Micron All Sky Survey near-infrared JHK photometry where available. We fitted the spectral-energy distributions of 671 star clusters and candidates to derive their ages, metallicities, and masses based on the updated PARSEC simple stellar populations synthesis models. The results of our χ{sup 2} minimization routines show that only 205 of the 671 clusters (31%) are older than 2 Gyr, which represents a much smaller fraction of the cluster population than that in M31 (56%), suggesting that M33 is dominated by young star clusters (<1 Gyr). We investigate the mass distributions of the star clusters—both open and globular clusters—in M33, M31, the Milky Way, and the Large Magellanic Cloud. Their mean values are log (M {sub cl}/M {sub ☉}) = 4.25, 5.43, 2.72, and 4.18, respectively. The fraction of open to globular clusters is highest in the Milky Way and lowest in M31. Our comparisons of the cluster ages, masses, and metallicities show that our results are basically in agreement with previous studies (where objects in common are available); differences can be traced back to differences in the models adopted, the fitting methods used, and stochastic sampling effects.

  15. Constitutive activation of oncogenic PDGFRα-mutant proteins occurring in GIST patients induces receptor mislocalisation and alters PDGFRα signalling characteristics.

    PubMed

    Bahlawane, Christelle; Eulenfeld, René; Wiesinger, Monique Y; Wang, Jiali; Muller, Arnaud; Girod, Andreas; Nazarov, Petr V; Felsch, Kathrin; Vallar, Laurent; Sauter, Thomas; Satagopam, Venkata P; Haan, Serge

    2015-03-31

    Gastrointestinal stromal tumours (GIST) are mainly characterised by the presence of activating mutations in either of the two receptor tyrosine kinases c-KIT or platelet-derived growth factor receptor-α (PDGFRα). Most mechanistic studies dealing with GIST mutations have focused on c-KIT and far less is known about the signalling characteristics of the mutated PDGFRα proteins. Here, we study the signalling capacities and corresponding transcriptional responses of the different PDGFRα proteins under comparable genomic conditions. We demonstrate that the constitutive signalling via the oncogenic PDGFRα mutants favours a mislocalisation of the receptors and that this modifies the signalling characteristics of the mutated receptors. We show that signalling via the oncogenic PDGFRα mutants is not solely characterised by a constitutive activation of the conventional PDGFRα signalling pathways. In contrast to wild-type PDGFRα signal transduction, the activation of STAT factors (STAT1, STAT3 and STAT5) is an integral part of signalling mediated via mutated PDGF-receptors. Furthermore, this unconventional STAT activation by mutated PDGFRα is already initiated in the endoplasmic reticulum whereas the conventional signalling pathways rather require cell surface expression of the receptor. Finally, we demonstrate that the activation of STAT factors also translates into a biologic response as highlighted by the induction of STAT target genes. We show that the overall oncogenic response is the result of different signatures emanating from different cellular compartments. Furthermore, STAT mediated responses are an integral part of mutated PDGFRα signalling.

  16. Structure of the human histamine H3 receptor gene (HRH3) and identification of naturally occurring variations.

    PubMed

    Wiedemann, P; Bönisch, H; Oerters, F; Brüss, M

    2002-04-01

    Neurotransmitter release is modulated by presynaptic histamine H(3) receptors located on histaminergic, noradrenergic and other nonhistaminergic neurons of the central and peripheral nervous system. Here, we report the determination of the structure of the human histamine H(3) receptor gene (HRH3) and the identification of a missense mutation (Ala280Val) in a patient with Shy-Drager syndrome. The coding region of the gene consists of three exons interrupted by two introns of approximately 1 kb in size. Exon boundaries only partly correspond to transmembrane domain organization. The homozygous Ala280Val variation in the third intracellular loop of the histamine H(3) receptor of a patient with Shy-Drager syndrome may be related to the etiology of the illness due to altered norepinephrine release. Furthermore, knowledge of the gene structure allows the verification of alternative splicing of the receptor. The corresponding histamine H(3) receptor isoforms as reported for the guinea pig and rat histamine H(3) receptor in different brain regions are not found in the human brain.

  17. Naturally-Occurring Glucosinolates, Glucoraphanin and Glucoerucin, are Antagonists to Aryl Hydrocarbon Receptor as Their Chemopreventive Potency.

    PubMed

    Abdull Razis, Ahmad Faizal; Noor, Noramaliza Mohd

    2015-01-01

    As a cytosolic transcription factor, the aryl hydrocarbon (Ah) receptor is involved in several patho- physiological events leading to immunosuppression and cancer; hence antagonists of the Ah receptor may possess chemoprevention properties. It is known to modulate carcinogen-metabolising enzymes, for instance the CYP1 family of cytochromes P450 and quinone reductase, both important in the biotransformation of many chemical carcinogens via regulating phase I and phase II enzyme systems. Utilising chemically-activated luciferase expression (CALUX) assay it was revealed that intact glucosinolates, glucoraphanin and glucoerucin, isolated from Brassica oleracea L. var. acephala sabellica and Eruca sativa ripe seeds, respectively, are such antagonists. Both glucosinolates were poor ligands for the Ah receptor; however, they effectively antagonised activation of the receptor by the avid ligand benzo[a]pyrene. Indeed, intact glucosinolate glucoraphanin was a more potent antagonist to the receptor than glucoerucin. It can be concluded that both glucosinolates effectively act as antagonists for the Ah receptor, and this may contribute to their established chemoprevention potency.

  18. VizieR Online Data Catalog: M33 WR and Of-type Stars (Neugent+, 2014)

    NASA Astrophysics Data System (ADS)

    Neugent, K. F.; Massey, P.

    2017-03-01

    Our ability to undertake this project was in a large part due to the existence of the multi-object fiber-fed spectrograph Hectospec (Fabricant et al. 2005PASP..117.1411F) on the 6.5 m MMT. Its large field of view (1° in diameter) was well matched to our survey areas of M31 and M33. Hectospec's 300 fibers and their allowed close spacing (20'') let us observe a multitude of candidates using only four pointing configurations. We were assigned 2.5 nights of dark time in the Fall of 2012 through NOAO (2012B-0129). When designing the fiber configurations, we were able to assign 71% of our M31 WRs using two configurations and 77% of our M33 WRs using an additional two configurations, making a total of four configurations. We were able to observe five of the remaining M33 candidates as part of the present study, and recently obtained spectra of the sixth star as part of our follow-up study of the binaries we identify here. (1 data file).

  19. Radial Velocity and Metallicity Determinations for Remote Globular Clusters in M31 and M33

    NASA Astrophysics Data System (ADS)

    Ferguson, Annette; Barmby, Pauline; Cote, Pat; Harris, Bill; Huxor, Avon; Mackey, Dougal; Puzia, Thomas

    2009-08-01

    We propose to determine radial velocities and metallicities for a sample of ~ 20 remote globular clusters (GCs) which we have discovered in the outer halos of the Local Group galaxies M31 and M33. Most of these objects have been uncovered in the course of the PAndAs survey, an international collaboration which is using CFHT/MegaPrime to map more than 300 square degrees in the g and i bands around M31 and M33. The target clusters, all of which have been identified from high- quality imaging (typically ≲ 0.8'' seeing), lie at projected radii of up to 130 kpc from M31 and 30 kpc from M33 and thus lie significantly beyond all previously-known GCs in these systems. Rather intriguingly, many of the new discoveries exhibit either possible associations with halo tidal streams, or show unusual spatial anisotropies with respect to their host galaxy. Velocity and metallicity data for these objects will provide a detailed characterization of the ensemble properties of the outer halo GC populations, and, through the search for kinematic and metallicity correlations within groups of GCs, help determine what fraction of these objects can be attributed to either late or ongoing accretion events. Ultimately, these data will also provide a basis for improved dynamical mass estimates of both galaxies.

  20. VizieR Online Data Catalog: Sample SNRs for M31 and M33 (Jennings+, 2014)

    NASA Astrophysics Data System (ADS)

    Jennings, Z. G.; Williams, B. F.; Murphy, J. W.; Dalcanton, J. J.; Gilbert, K. M.; Dolphin, A. E.; Weisz, D. R.; Fouesneau, M.

    2017-05-01

    First, we select SNRs from catalogs which overlap with HST fields in M31 and M33. We limited our search to fields observed with the ACS and WFPC-2 instruments, as the optical CMDs tend to be deeper and offer the best SFH constraints. For M31, we combine three SNR catalogs to select targets from: Braun & Walterbos (1993A&AS...98..327B); Magnier et al. (1995, J/A+AS/114/215); Williams et al. (1995BAAS...27..883W). All three catalogs make use of [S II]-to-Hα ratios to identify SNR. Our M33 SNR catalog comes from Long et al. (2010, J/ApJS/187/495), who selected SNRs using both [S II]-to-Hα ratios and X-ray observations. Long et al. (2010, J/ApJS/187/495) incorporated all previous SNR catalogs from the literature in their analysis. As mentioned in Section 1, all new M31 data analyzed in this work come from newly available PHAT data sets and therefore have uniform filters and exposure times, while the M33 data comes from various archival data sets coincident with SNR. (1 data file).

  1. Radio properties of M33 supernova remnants: results from a new deep JVLA Survey

    NASA Astrophysics Data System (ADS)

    Long, Knox S.; White, Richard L.; Becker, Robert H.; Helfand, David J.; Blair, William P.; Winkler, P. Frank

    2016-06-01

    We have carried out new 6 and 20 cm observations of M33 with the Jansky Very Large Array, primarily to study the properties of supernova remnants in the galaxy. Our scaled array observations have a limiting sensitivity of about 25 μJy (5σ) and a resolution of 5`` (FWHM), corresponding to a spatial resolution of 20 pc at the distance of M33. We detect about 85 of the SNRs contained in the list of 137 optically identified SNRs described by Long et al. (2010), and a few additional objects from the survey of Lee & Lee (2014). A substantial fraction of the optical SNRs not detected are in regions where emission from H II recombination makes identification of non-thermal emission from the SNR difficult. We also discuss a blind search for SNRs based on the radio emission alone. Of the SNRs we detect in this search at radio wavelengths, 53 have also been detected at X-ray wavelengths. Thus we are able make a direct comparison of the X-ray, optical, and radio properties of the SNRs in M33, the first time that has been possible to a significant extent in an external spiral galaxy.

  2. THE DEGENERACY OF M33 MASS MODELING AND ITS PHYSICAL IMPLICATIONS

    SciTech Connect

    Hague, P. R.; Wilkinson, M. I. E-mail: miw6@le.ac.uk

    2015-02-10

    The Local Group galaxy M33 exhibits a regular spiral structure and is close enough to permit high resolution analysis of its kinematics, making it an ideal candidate for rotation curve studies of its inner regions. Previous studies have claimed the galaxy has a dark matter halo with an Navarro-Frenk-White profile, based on statistical comparisons with a small number of other profiles. We apply a Bayesian method from our previous paper to place the dark matter density profile in the context of a continuous, and more general, parameter space. For a wide range of initial assumptions we find that models with inner log slope γ{sub in} < 0.9 are strongly excluded by the kinematics of the galaxy unless the mass-to-light ratio of the stellar components in the 3.6 μm band satisfies Y{sub 3.6} ≥ 2. Such a high Y{sub 3.6} is inconsistent with current modeling of the stellar population of M33. This suggests that M33 is a galaxy whose dark matter halo has not been significantly modified by feedback. We discuss possible explanations of this result, including ram pressure stripping during earlier interactions with M31.

  3. Spectroscopic study of formation, evolution and interaction of M31 and M33 with star clusters

    NASA Astrophysics Data System (ADS)

    Fan, Zhou; Yang, Yanbin

    2016-02-01

    The recent studies show that the formation and evolution process of the nearby galaxies are still unclear. By using the Canada France Hawaii Telescope (CFHT) 3.6m telescope, the PanDAS shows complicated substructures (dwarf satellite galaxies, halo globular clusters, extended clusters, star streams, etc.) in the halo of M31 to ~150 kpc from the center of galaxy and M31-M33 interaction has been studied. In our work, we would like to investigate formation, evolution and interaction of M31 and M33, which are the nearest two spiral galaxies in Local Group. The star cluster systems of the two galaxies are good tracers to study the dynamics of the substructures and the interaction. Since 2010, the Xinglong 2.16m, Lijiang 2.4m and MMT 6.5m telescopes have been used for our spectroscopic observations. The radial velocities and Lick absorption-line indices can thus be measured with the spectroscopy and then ages, metallicities and masses of the star clusters can be fitted with the simple stellar population models. These parameters could be used as the input physical parameters for numerical simulations of M31-M33 interaction.

  4. On the Neutral Hydrogen Filament Between M31 and M33

    NASA Astrophysics Data System (ADS)

    Lockman, Felix J.; Free, N.; Shields, J. C.

    2012-01-01

    In 2004, Braun & Thilker (B&T) reported the detection of extremely faint 21cm HI emission at the level log10(NH)=17.0 that formed a partial bridge about 200 kpc in extent between M31 and M33. This has been interpreted as the neutral component of a WHIM filament, or the remnant of a past encounter between the two galaxies. B&T used data from the Westerbork Synthesis Radio Telescope, operated as an array of single dishes, to obtain the necessary sensitivity, but at the expense of angular resolution ( 45'). Subsequently, Putman et al (2009) have questioned the existence of this filament, noting its absence from the immediate vicinity of M33 at the level log10(NH) 18 in data from Arecibo. We have reobserved much of the region between M31 and M33 using the Green Bank Telescope (GBT) at 9' resolution, with a 5-sigma sensitivity limit of log10(NHI) 18.0 and a few much deeper pointings. We detect HI lines consistent with the B&T results. In two locations the emission appears at log(NHI)>18.3, suggesting clumping in the otherwise diffuse gas. We estimate the mass of HI in the bridge, and show examples of the GBT's freedom from instrumental effects down to detection levels of log(NHI) 17.0. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under a cooperative agreement by Associated Universities, Inc.

  5. Millimeter and submillimeter excess emission in M 33 revealed by Planck and LABOCA

    NASA Astrophysics Data System (ADS)

    Hermelo, I.; Relaño, M.; Lisenfeld, U.; Verley, S.; Kramer, C.; Ruiz-Lara, T.; Boquien, M.; Xilouris, E. M.; Albrecht, M.

    2016-05-01

    Context. Previous studies have shown the existence of an excess of emission at submillimeter (submm) and millimeter (mm) wavelengths in the spectral energy distribution (SED) of many low-metallicity galaxies. The so-called "submm excess", whose origin remains unknown, challenges our understanding of the dust properties in low-metallicity environments. Aims: The goal of the present study is to model separately the emission from the star forming (SF) component and the emission from the diffuse interstellar medium (ISM) in the nearby spiral galaxy M 33 in order to determine whether both components can be well fitted using radiation transfer models or whether there is an excess of submm emission associated with one or both of them. Methods: We decomposed the observed SED of M 33 into its SF and diffuse components. Mid-infrared (MIR) and far-infrared (FIR) fluxes were extracted from Spitzer and Herschel data. At submm and mm wavelengths, we used ground-based observations from APEX to measure the emission from the SF component and data from the Planck space telescope to estimate the diffuse emission. Both components were separately fitted using radiation transfer models based on standard dust properties (i.e., emissivity index β = 2) and a realistic geometry. The large number of previous studies helped us to estimate the thermal radio emission and to constrain an important part of the input parameters of the models. Both modeled SEDs were combined to build the global SED of M 33. In addition, the radiation field necessary to power the dust emission in our modeling was compared with observations from GALEX, Sloan, and Spitzer. Results: Our modeling is able to reproduce the observations at MIR and FIR wavelengths, but we found a strong excess of emission at submm and mm wavelengths where the model expectations severely underestimate the LABOCA and Planck fluxes. We also found that the ultraviolet (UV) radiation escaping the galaxy is 70% higher than the model predictions

  6. Activation and desensitization of peripheral muscle and neuronal nicotinic acetylcholine receptors by selected, naturally-occurring pyridine alkaloids

    USDA-ARS?s Scientific Manuscript database

    Teratogenic alkaloids can cause developmental defects due to inhibition of fetal movement that results from desensitization of fetal muscletype nicotinic acetylcholine receptors (nAChRs). We investigated the ability of two known teratogens, the piperidinyl-pyridine anabasine and its 1,2-dehydropiper...

  7. The antipsychotic potential of l-stepholidine--a naturally occurring dopamine receptor D1 agonist and D2 antagonist.

    PubMed

    Natesan, Sridhar; Reckless, Greg E; Barlow, Karen B L; Odontiadis, John; Nobrega, José N; Baker, Glen B; George, Susan R; Mamo, David; Kapur, Shitij

    2008-08-01

    l-Stepholidine, a dopamine D(2) antagonist with D(1) agonist activity, should in theory control psychosis and treat cognitive symptoms by enhancing cortical dopamine transmission. Though several articles describe its impact on the dopamine system, it has not been systematically evaluated and compared to available antipsychotics. We examined its in vitro interaction with dopamine D(2) and D(1) receptors and compared its in vivo pharmacokinetic profile to haloperidol (typical) and clozapine (atypical) in animal models predictive of antipsychotic activity. In vitro, l-stepholidine showed significant activity on dopamine receptors, and in vivo, l-stepholidine demonstrated a dose-dependent striatal receptor occupancy (RO) at D(1) and D(2) receptors (D(1) 9-77%, 0.3-30 mg/kg; D(2) 44-94%, 1-30 mg/kg), though it showed a rather rapid decline of D(2) occupancy related to its quick elimination. In tests of antipsychotic efficacy, it was effective in reducing amphetamine- and phencyclidine-induced locomotion as well as conditioned avoidance response, whereas catalepsy and prolactin elevation, the main side effects, appeared only at high D(2)RO (>80%). This preferential therapeutic profile was supported by a preferential immediate early gene (Fos) induction in the nucleus accumbens over dorsolateral striatum. We confirmed its D(1) agonism in vitro, and then using D(2) receptor, knockout mice showed that l-stepholidine shows D(1) agonism in the therapeutic dose range. Thus, l-stepholidine shows efficacy like an "atypical" antipsychotic in traditional animal models predictive of antipsychotic activity and shows in vitro and in vivo D(1) agonism, and, if its rapid elimination does not limit its actions, it could provide a unique therapeutic approach to schizophrenia.

  8. The HII Regions and OB Stars of M33 and NCG 6822.

    NASA Astrophysics Data System (ADS)

    Patel, Kanan

    1995-01-01

    We have used Hα and photometric data for two morphologically distinct Local Group galaxies, the spiral M33 and dwarf irregular NGC 6822, to study the distribution of the luminous blue O and B (OB) stars and HII regions in the galaxies as well as to determine whether individual regions of the galaxies are separately and/or collectively in a state of ionization balance. In the case of M33, we have concentrated on the inner 1 kpc region of the galaxy. Using the H alpha data, three distinct ionized gas environments (bright, halo and field) defined by the surface brightness of the Hα emission have been identified. We find that ~50% of the OB stars are located in the field, so that 1/2 of the lifetime of OB stars must be spent outside recognizable HII regions. We show that a possible origin for the large field OB population is that they were born in and subsequently percolated out of the ~10 ^3 giant molecular clouds with masses _sp{~}>10 ^3Modot predicted to exist within the inner kpc of the galaxy. Using UBV photometry and stellar ionization models, we predict Hα fluxes in the bright, halo and field regions. Our findings suggest that star formation rates obtained from luminosities must underestimate the true star formation rate within the inner region of M33. In the case of NGC 6822, four distinct components of the Hα emission (bright, halo, diffuse and field) differentiated by their surface brightnesses have been identified. We find that only 1/4 of the OB stars are found in the combined bright halo regions, suggesting that OB stars spend roughly 3/4 of their lifetimes outside "classical" HII regions. Molecular cloud lifetimes after forming OB stars could be as low as ~1 -3 times 10^6 yrs or 1/4 the typical main sequence lifetimes of OB stars if stars escape from bright HII regions by destroying their parent clouds. Additionally, the field population of OB stars cannot have originated in and percolated out of existing HII regions. Comparing the observed H

  9. Decreased agonist, but not antagonist, binding to the naturally occurring Thr92Lys variant of the h5-HT7(a) receptor.

    PubMed

    Brüss, Michael; Kiel, Sibylle; Bönisch, Heinz; Kostanian, Arevat; Göthert, Manfred

    2005-08-01

    In the present study on transfected human embryonic kidney (HEK)293 cells, we aimed at establishing whether expression of the naturally occurring Thr92Lys variation of the Gs-coupled h5-HT7(a) receptor leads to changes of ligand binding properties, of agonist-evoked cAMP formation and/or of antagonist-mediated blockade of the latter. Binding of [3H]5-carboxamidotryptamine ([3H]5-CT) to membranes and stimulated [3H]cAMP accumulation in whole cells were determined. Saturation binding experiments in membranes of transiently transfected cells expressing either the wild-type or the variant receptor revealed a single binding site in both cases and no difference in Bmax between both receptor isoforms. In competition binding experiments in membranes of stably transfected cells, the Thr92Lys variant exhibited a 2.8-11 times lower binding affinity of the ligands 5-hydroxytryptamine (5-HT), 5-CT, 5-methoxy-3-(1,2,3,6-tetrahydropyridin-4yl)-1H-indole (RU24969), (+/-)-hydroxy-2-(di-n-propylamino)tetralin hydrobromide (8-OH-DPAT) and sumatriptan compared to the wild-type receptor. However, the variant did not differ from the wild-type with respect to the binding properties of the antagonists (R)-3-(2-(2-(4-methylpiperidin-1-yl)ethyl)-pyrrolodine-1-sulfonyl)phenol hydrochloride (SB-269970), risperidone, mesulergine and clozapine. In agreement with the decreased binding affinity of 5-HT, 5-CT, RU24969 and 8-OH-DPAT for the variant receptor, these agonists were less potent in stimulating [3H]cAMP accumulation in cells stably expressing the Thr92Lys h5-HT7(a) receptor. Sumatriptan did not stimulate cAMP accumulation in spite of its affinity for both receptor isoforms pointing to a putative weak antagonistic property of this drug at the h5-HT7 receptor. SB-269970 and clozapine were equipotent at both the variant and the wild-type receptor in producing a rightward shift of the 5-HT concentration-response curve for its stimulant effect on [3H]cAMP accumulation. In view of, e.g., the

  10. OBJECT X: THE BRIGHTEST MID-INFRARED POINT SOURCE IN M33

    SciTech Connect

    Khan, Rubab; Stanek, K. Z.; Kochanek, C. S.; Bonanos, A. Z. E-mail: kstanek@astronomy.ohio-state.edu E-mail: bonanos@astro.noa.gr

    2011-05-01

    We discuss the nature of the brightest mid-IR point source (which we dub Object X) in the nearby galaxy M33. Although multi-wavelength data on this object have existed in the literature for some time, it had not previously been recognized as the most luminous mid-IR object in M33 because it is entirely unremarkable in both optical and near-IR light. In the Local Group Galaxies Survey, Object X is a faint red source visible in VRI and H{alpha} but not U or B. It was easily seen at JHK{sub s} in the Two Micron All Sky Survey. It is the brightest point source in all four Spitzer IRAC bands and is also visible in the MIPS 24 {mu}m band. Its bolometric luminosity is {approx}5 x 10{sup 5} L{sub sun}. The source is optically variable on short timescales (tens of days) and is also slightly variable in the mid-IR, indicating that it is a star. Archival photographic plates (from 1949 and 1991) show no optical source, so the star has been obscured for at least half a century. Its properties are similar to those of the Galactic OH/IR star IRC+10420, which has a complex dusty circumstellar structure resulting from episodic low-velocity mass ejections. We propose that Object X is an M {approx}> 30 M{sub sun} evolved star obscured in its own dust ejected during episodic mass-loss events over at least {approx}half a century. It may emerge from its current ultra-short evolutionary phase as a hotter post-red-supergiant star analogous to M33 Var A. The existence and rarity of such objects can be an important probe of a very brief yet eventful stellar evolutionary phase.

  11. Clouds of neutral hydrogen between M31 and M33 and around the Milky Way

    NASA Astrophysics Data System (ADS)

    Wolfe, Spencer A.; Pisano, D. J.; Lockman, F. J.; McGaugh, S. S.; Shaya, E. J.

    2014-01-01

    Large spiral galaxies like our own Milky Way must acquire fresh gas to continue forming new stars. The gas that resides between galaxies may be a source of this material, but we know little about the gas’ structure or extent. I will present my thesis research, which attempts to answer these questions, based on our Green Bank Telescope (GBT) observations of the very faint M31-M33 neutral hydrogen (HI) stream that was first discovered a decade ago using the Westerbork Synthesis Radio Telescope. Our spectral line observations have over five times higher spatial resolution and roughly three times higher velocity resolution than the Westerbork data. These are the most sensitive observations of the 21 cm line conducted with the GBT. I will discuss our observing and reduction techniques used to reach the sensitivities needed to study the HI stream in detail. We find that the gas is actually composed of small clouds only a few kiloparsecs in diameter. The kinematics of the clouds also suggests that they are associated with M31 and M33 and not each galaxy’s respective High Velocity Cloud (HVC) population. Most, if not all, of the clouds do not appear to have stars associated with them. Thus, we believe that these clouds are part of a condensing intergalactic filament and may be a source of future star formation for M31 and M33. In addition, I will briefly present my research on the High Velocity and Intermediate Velocity Clouds around our Milky Way using the Galactic All-Sky Survey (GASS) at 21 cm that was conducted with the Parkes 64m radio telescope. I will discuss the basic properties of this gas and some interesting features seen in the survey.

  12. Evidence for temporal evolution in the M33 disc as traced by its star clusters

    NASA Astrophysics Data System (ADS)

    Beasley, Michael A.; San Roman, Izaskun; Gallart, Carme; Sarajedini, Ata; Aparicio, Antonio

    2015-08-01

    We present precision radial velocities and stellar population parameters for 77 star clusters in the Local Group galaxy M33. Our Gran Telescopio de Canarias and William Herschel Telescope observations sample both young, massive clusters and known/candidate globular clusters (GCs), spanning ages ˜106-1010 yr, and metallicities, [M/H] ˜ -1.7 to solar. The cluster system exhibits an age-metallicity relation; the youngest clusters are the most metal rich. When compared to H I data, clusters with [M/H] ˜ -1.0 and younger than ˜4 Gyr are clearly identified as a disc population. The clusters show evidence for strong time evolution in the disc radial metallicity gradient (d[M/H]dt/dR = 0.03 dex kpc-1 Gyr-1). The oldest clusters have stronger, more negative gradients than the youngest clusters in M33. The clusters also show a clear age-velocity dispersion relation. The line-of-sight velocity dispersions of the clusters increases with age similar to Milky Way open clusters and stars. The general shape of the relation is reproduced by disc heating simulations, and the similarity between the relations in M33 and the Milky Way suggests that heating by substructure and cooling of the interstellar medium both play a role in shaping this relation. We identify 12 `classical' GCs, six of which are newly identified GC candidates. The GCs are more metal rich than Milky Way halo clusters, and show weak rotation. The inner (R < 4.5 kpc) GCs exhibit a steep radial metallicity gradient (d[M/H]/dR = -0.29 ± 0.11 dex kpc-1) and an exponential-like surface density profile. We argue that these inner GCs are thick disc rather than halo objects.

  13. Planetary nebulae search in the outskirts of M33: looking for the farthest candidates

    NASA Astrophysics Data System (ADS)

    Galera Rosillo, Rebeca; Corradi, Romano L. M.; Mampaso Recio, Antonio

    2015-08-01

    The nearby disc galaxy M33 is one of the best laboratories for testing chemical evolution models in galaxies and for understanding disc formation mechanisms. In this galaxy, planetary nebulae (PNe) were previously extensively studied only within a galactocentric radius of 8 kpc.In the framework of a broad study of the population of PNe in Local Group disc galaxies, we present the results of a deep narrow-band imaging of the outer regions of M33, performed using the Wide Field Camera at the 2.5 m Isaac Newton Telescope (INT).The INT images were obtained in the narrow-band filters selecting the [OIII] 5007 Å and Hα 6563 Å lines, plus broad-band filters SDSS g and i. A photometric catalog of around 150000 sources covering a total area of 5 square degrees, and extending out to 2 deg (30 kpc at the adopted distance of 840 kpc) from the centre of the galaxy is presented.PNe candidates are selected in the [OIII]-g vs Hα-r colour-colour diagram as bright emitters in the narrowband filters. A number of candidates with similar colours to those of known PNe, and with an apparent [OIII] magnitude > 21 have been selected for future follow-up. Three of these have been already spectroscopically confirmed at the William Herschel Telescope (WHT).Our survey will improve the knowledge of the PNe population in the outskirts of M33, constraining the properties of its metal-poor halo and of the extended disc substructures that have been proposed to be related to a relatively recent interaction with M31.

  14. The star formation history in the far outer disc of M33

    NASA Astrophysics Data System (ADS)

    Barker, Michael K.; Ferguson, A. M. N.; Cole, A. A.; Ibata, R.; Irwin, M.; Lewis, G. F.; Smecker-Hane, T. A.; Tanvir, N. R.

    2011-01-01

    The outer regions of disc galaxies are becoming increasingly recognized as key testing sites for models of disc assembly and evolution. Important issues are the epoch at which the bulk of the stars in these regions formed and how discs grow radially over time. To address these issues, we use Hubble Space Telescope Advanced Camera for Surveys imaging to study the star formation history (SFH) of two fields at 9.1 and 11.6 kpc along M33's northern major axis. These fields lie at ˜ 4 and 5 V-band disc scalelengths and straddle the break in M33's surface brightness profile. The colour-magnitude diagrams (CMDs) reach the ancient main-sequence turn-off with a signal-to-noise ratio of ˜ 5. From detailed modelling of the CMDs, we find that the majority of stars in both fields combined formed at z < 1. The mean age in the inner field, S1, is ˜ 3 ± 1 Gyr and the mean metallicity is [M/H]˜- 0.5 ± 0.2 dex. The SFH of S1 unambiguously reveals how the inside-out growth previously measured for M33's inner disc out to ? extends out to the disc edge at ?. In comparison, the outer field, S2, is older (mean age ˜ 7 ± 2 Gyr), more metal-poor (mean [M/H]˜- 0.8 ± 0.3 dex), and contains ˜ 30 times less stellar mass. These results provide the most compelling evidence yet that M33's age gradient reverses at large radii near the disc break and that this reversal is accompanied by a break in stellar mass surface density. We discuss several possible interpretations of this behaviour including radial stellar mixing, warping of the gaseous disc, a change in star formation efficiency and a transition to another structural component. These results offer one of the most detailed views yet of the peripheral regions of any disc galaxy and provide a much needed observational constraint on the last major epoch of star formation in the outer disc.

  15. VizieR Online Data Catalog: VI photometry of M33 star clusters (Chandar+, 2001)

    NASA Astrophysics Data System (ADS)

    Chandar, R.; Bianchi, L.; Ford, H. C.

    2000-11-01

    File table2 contains coordinates and photometric properties of compact M33 clusters discovered in Hubble Space Telescope WFPC2 V and I band images. The columns contain: identification, RA (J2000), DEC (J2000), galactocentric distance (kpc), apparent V magnitude, radius used to measure color, Johnson-Cousins (V-I) color, cross identification of objects with Christian & Schommer (1988AJ.....95..704C) and Mochejska et al. (1998AcA....48..455M), previously published V magnitude if available, previously published (V-I) color if available, and estimated core radius. (1 data file).

  16. Modeling hydrogen-rich Wolf-Rayet stars in M33

    NASA Astrophysics Data System (ADS)

    Maryeva, Olga

    2013-05-01

    We present the results of a spectral variability study of two very luminous stars in the M33 galaxy - LBV V532 and late WN star(possibly, dormant LBV) FSZ35. We studied the spectral variability of V532, derived its atmosphere parameters and showed that the bolometric luminosity varied between the two states by a factor of ˜1.5. Using the non-LTE radiative transfer code CMFGEN, we determined the wind parameters for both objects. Since both stars are located at distances of about 100 pc from the nearest association, we supposed that they may be massive runaway stars with velocities of the order 100 kms.

  17. A Search for Miras in M33 Using Sparsely-Sampled Time Series Photometry

    NASA Astrophysics Data System (ADS)

    Yuan, Wenlong; Macri, Lucas M.; He, Shiyuan; Long, James; Huang, Jianhua

    2017-01-01

    The Mira Period-Luminosity relations (PLRs) at near- and mid-infrared wavelengths are promising distance indicators, with brighter absolute magnitudes than Cepheids, comparable PLR dispersions and ubiquitous presence in all galaxy types. We developed a semi-parametric Gaussian process periodogram method for sparsely-sampled Mira light curves and applied it to I-band observations of M33. We discovered more than 1800 Miras, which were subsequently classified using machine-learning techniques. We present an overview of the Gaussian process model, the Random Forest classifiers, and the resulting PLRs.

  18. Carbon and oxygen abundance gradients in NGC 300 and M33 from optical recombination lines

    NASA Astrophysics Data System (ADS)

    Toribio San Cipriano, L.; García-Rojas, J.; Esteban, C.; Bresolin, F.; Peimbert, M.

    2016-05-01

    We present deep spectrophotometry of several H II regions in the nearby low-mass spiral galaxies NGC 300 and M33. The data have been taken with Ultraviolet-Visual Echelle Spectrograph and Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy spectrographs attached to the 8-m Very Large Telescope and 10.4-m Gran Telescopio Canarias telescopes, respectively. We have derived precise values of the physical conditions for each object making use of several emission line-intensity ratios. In particular, we have obtained direct determinations of the electron temperature in all the observed objects. We detect pure recombination lines (RLs) of C II and O II in several of the H II regions, permitting to derive their C/H and C/O ratios. We have derived the radial abundance gradient of O for each galaxy making use of collisionally excited lines (CELs) and RLs, as well as the C and N gradients using RLs and CELs, respectively. We obtain the first determination of the C/H gradient of NGC 300 and improve its determination in the case of M33. In both galaxies, the C/H gradients are steeper than those of O/H, leading to negative C/O gradients. Comparing with similar results for other spiral galaxies, we find a strong correlation between the slope of the C/H gradient and MV. We find that some H II regions located close to the isophotal radius (R25) of NGC 300 and M33 show C/O ratios more similar to those typical of dwarf galaxies than those of H II regions in the discs of more massive spirals. This may be related to the absence of flattening of the gradients in the external parts of NGC 300 and M33. Finally, we find very similar N/H gradients in both galaxies and a fair correlation between the slope of the N/H gradient and MV comparing with similar data for a sample of spiral galaxies.

  19. The Massive Stellar Population in the Diffuse Ionized Gas of M33

    NASA Technical Reports Server (NTRS)

    Hoopes, Charles G.; Walterbos, Rene A. M.

    1995-01-01

    We compare Far-UV, H alpha, and optical broadband images of the nearby spiral galaxy M33, to investigate the massive stars associated with the diffuse ionized gas. The H-alpha/FUV ratio is higher in HII regions than in the DIG, possibly indicating that an older population ionizes the DIG. The broad-band colors support this conclusion. The HII region population is consistent with a young burst, while the DIG colors resemble an older population with constant star formation. Our results indicate that there may be enough massive field stars to ionize the DIG, without the need for photon leakage from HII regions.

  20. Receptor-Mediated Endocytosis of Two-Dimensional Nanomaterials Undergoes Flat Vesiculation and Occurs by Revolution and Self-Rotation.

    PubMed

    Mao, Jian; Chen, Pengyu; Liang, Junshi; Guo, Ruohai; Yan, Li-Tang

    2016-01-26

    Two-dimensional nanomaterials, such as graphene and transitional metal dichalcogenide nanosheets, are promising materials for the development of antimicrobial surfaces and the nanocarriers for intracellular therapy. Understanding cell interaction with these emerging materials is an urgently important issue to promoting their wide applications. Experimental studies suggest that two-dimensional nanomaterials enter cells mainly through receptor-mediated endocytosis. However, the detailed molecular mechanisms and kinetic pathways of such processes remain unknown. Here, we combine computer simulations and theoretical derivation of the energy within the system to show that the receptor-mediated transport of two-dimensional nanomaterials, such as graphene nanosheet across model lipid membrane, experiences a flat vesiculation event governed by the receptor density and membrane tension. The graphene nanosheet is found to undergo revolution relative to the membrane and, particularly, unique self-rotation around its normal during membrane wrapping. We derive explicit expressions for the formation of the flat vesiculation, which reveals that the flat vesiculation event can be fundamentally dominated by a dimensionless parameter and a defined relationship determined by complicated energy contributions. The mechanism offers an essential understanding on the cellular internalization and cytotoxicity of the emerging two-dimensional nanomaterials.

  1. THE M31 VELOCITY VECTOR. III. FUTURE MILKY WAY M31-M33 ORBITAL EVOLUTION, MERGING, AND FATE OF THE SUN

    SciTech Connect

    Van der Marel, Roeland P.; Sohn, Sangmo Tony; Anderson, Jay; Besla, Gurtina; Cox, T. J.

    2012-07-01

    We study the future orbital evolution and merging of the Milky Way (MW)-M31-M33 system, using a combination of collisionless N-body simulations and semi-analytic orbit integrations. Monte Carlo simulations are used to explore the consequences of varying all relevant initial phase-space and mass parameters within their observational uncertainties. The observed M31 transverse velocity from Papers I and II implies that the MW and M31 will merge t = 5.86{sup +1.61}{sub -0.72} Gyr from now. The first pericenter occurs at t = 3.87{sup +0.42}{sub -0.32} Gyr, at a pericenter distance of r = 31.0{sup +38.0}{sub -19.8} kpc. In 41% of Monte Carlo orbits, M31 makes a direct hit with the MW, defined here as a first-pericenter distance less than 25 kpc. For the M31-M33 system, the first-pericenter time and distance are t = 0.85{sup +0.18}{sub -0.13} Gyr and r = 80.8{sup +42.2}{sub -31.7} kpc. By the time M31 gets to its first pericenter with the MW, M33 is close to its second pericenter with M31. For the MW-M33 system, the first-pericenter time and distance are t = 3.70{sup +0.74}{sub -0.46} Gyr and r = 176.0{sup +239.0}{sub -136.9} kpc. The most likely outcome is for the MW and M31 to merge first, with M33 settling onto an orbit around them that may decay toward a merger later. However, there is a 9% probability that M33 makes a direct hit with the MW at its first pericenter, before M31 gets to or collides with the MW. Also, there is a 7% probability that M33 gets ejected from the Local Group, temporarily or permanently. The radial mass profile of the MW-M31 merger remnant is significantly more extended than the original profiles of either the MW or M31, and suggests that the merger remnant will resemble an elliptical galaxy. The Sun will most likely ({approx}85% probability) end up at a larger radius from the center of the MW-M31 merger remnant than its current distance from the MW center, possibly further than 50 kpc ({approx}10% probability). There is a {approx}20

  2. Disruption and reformation of the acetylcholine receptor clusters of cultured rat myotubes occur in two distinct stages.

    PubMed

    Pumplin, D W; Bloch, R J

    1987-01-01

    We have examined the redistribution of acetylcholine receptor (AChR) intramembrane particles (IMPs) when AChR clusters of cultured rat myotubes are experimentally disrupted and allowed to reform. In control myotubes, the AChR IMPs are evenly distributed within the AChR domains of cluster membrane. Shortly after addition of azide to disrupt clusters, IMPs become unevenly scattered, with some microaggregation. After longer treatment, IMPs are depleted from AChR domains with no further change in IMP distribution. Contact domains of clusters are relatively poor in IMPs both before and after cluster dispersal. Upon visualization with fluorescent alpha-bungarotoxin, some AChR in azide-treated samples appear as small, bright spots. These spots do not correspond to microaggregates seen in freeze-fracture replicas, and probably represent receptors that have been internalized. The internalization rate is insufficient to account completely for the loss of IMPs from clusters, however. During reformation of AChR clusters upon removal of azide, IMP concentration in receptor domains increases. At early stages of reformation, IMPs appear in small groups containing compact microaggregates. At later times, AChR domains enlarge and IMPs within them assume the evenly spaced distribution characteristic of control clusters. These observations suggest that the disruption of clusters is accompanied by mobilization of AChR from a fixed array, allowing AChR IMPs to diffuse away from the clusters, to form microaggregates, and to become internalized. Cluster reformation appears to be the reverse of this process. Our results are thus consistent with a two-step model for AChR clustering, in which the concentration of IMPs into a small membrane region precedes their rearrangement into evenly spaced sites.

  3. THE FRACTAL DIMENSION OF STAR-FORMING REGIONS AT DIFFERENT SPATIAL SCALES IN M33

    SciTech Connect

    Sanchez, Nestor; Alfaro, Emilio J.; Anez, Neyda; Odekon, Mary Crone

    2010-09-01

    We study the distribution of stars, H II regions, molecular gas, and individual giant molecular clouds in M33 over a wide range of spatial scales. The clustering strength of these components is systematically estimated through the fractal dimension. We find scale-free behavior at small spatial scales and a transition to a larger correlation dimension (consistent with a nearly uniform distribution) at larger scales. The transition region lies in the range {approx}500-1000 pc. This transition defines a characteristic size that separates the regime of small-scale turbulent motion from that of large-scale galactic dynamics. At small spatial scales, bright young stars and molecular gas are distributed with nearly the same three-dimensional fractal dimension (D {sub f,3D} {approx}< 1.9), whereas fainter stars and H II regions exhibit higher values, D {sub f,3D} {approx_equal} 2.2-2.5. Our results indicate that the interstellar medium in M33 is on average more fragmented and irregular than in the Milky Way.

  4. The Herschel view of HII regions in M 33 (HERM33ES)

    NASA Astrophysics Data System (ADS)

    Verley, S.; Relaño, M.; Kramer, C.; Xilouris, E. M.; Boquien, M.; Calzetti, D.; Combes, F.; Buchbender, C.; Braine, J.; Quintana-Lacaci, G.; Tabatabaei, F. S.; Lord, S.; Israel, F.; Stacey, G.; van der Werf, P.

    2010-12-01

    Within the framework of the HERM33ES Key Project (Kramer et al. 2010), using the high resolution and sensitivity of the Herschel photometric data, we study the compact emission in the Local Group spiral galaxy M 33. We present a catalogue of 159 compact emission sources in M 33 identified by SExtractor in the 250 μm SPIRE band which is the one that provides the best spatial resolution. We measure fluxes at 24 μm and Hα for those 159 extracted sources. We find a very strong Pearson correlation coefficient with the MIPS 24 μm emission (r24 = 0.94) and a rather strong correlation with the Hα emission, although with more scatter (rHα = 0.83). Due to the very strong link between the 250 μm compact emission and the 24 μm and Hα emissions, by recovering the star formation rate from standard recipes for H II regions, we are able to provide star formation rate calibrations based on the 250 μm compact emission alone. Finally, the morphological study of a set of three Hα shells shows that there is a displacement between far-ultraviolet and the SPIRE bands, while the Hα structure is in general much more coincident with the cool dust.

  5. Uv Observations of the Hubble-Sandage Variables in M31 and M33

    NASA Astrophysics Data System (ADS)

    Humphreys, Roberta

    1991-07-01

    The Hubble-Sandage variables in M31 and M33 are luminous blue variables (LBVs) -- very luminous, eruptively unstable stars in the same general class as S Dor, Eta Car, and P Cyg. UV observations of H-S variables will significantly enhance the limited information available to us concerning the evolution and structure of the most massive stars. ---- LBVs are important in several major astrophysical connections and are only beginning to be understood. Since the LBV stage of evolution is brief, only a few examples are available in our Galaxy and in the Magellanic Clouds, close enough for UV observations with IUE. Therefore our coverage of the wide parameter space embraced by LBVs has been so sparse that theoretical development has been hindered. ---- With the ST, we can significantly increase this coverage by adding the H-S variables in M31 and M33 to the set of "useful" LBVs. UV spectroscopy is needed to determine their temperatures, luminosities, and mass-loss rates. These parameters are required to clarify their relations to other LBVs and very massive stars in general, and to provide more information on evolutionary origin of LBVs, physical causes of the violent eruptions, and other problems.

  6. New quasar surveys with WIRO: UV variability of known quasars behind M33

    NASA Astrophysics Data System (ADS)

    Deam, Sophie; Bassett, Neil; Dixon, Don; Griffith, Emily; Harvey, William Bradford; Lee, Daniel; Lyke, Bradley; Haze Nunez, Evan; Parziale, Ryan; Witherspoon, Catherine; Myers, Adam D.; Findlay, Joseph; Kobulnicky, Henry A.; Dale, Daniel A.

    2017-01-01

    Bright quasars are of particular interest when detected through the extended gaseous regions of local galaxies. Spectroscopy of UV-bright quasars, in particular, can be used to map the properties of the gas surrounding foreground galaxies in absorption. As our atmosphere absorbs UV flux, UV-bright quasars behind galaxies have been a regular target of spectroscopic campaigns with HST. The utility of such quasars is usually predicated on their UV emission at a single epoch. But, some quasars vary significantly in the UV, so objects which have shown a recent increase in UV flux may also be good candidates for spectroscopic follow-up with HST. We have analyzed the changes in u-band measurements of known quasars within a recent observational survey of quasars behind M33. Imaging in the u-band of a region around M33 containing ~35 known quasars was conducted at the Wyoming Infrared Observatory (WIRO) in the summer of 2016. We report on the known quasars which show the most u-band variability between our WIRO campaign and earlier SDSS observations. By correlating u-band observations with GALEX NUV, we determine the likelihood that an increase in u-band flux is a good indicator of an increase in flux further in the UV. This work is supported by the National Science Foundation under REU grant AST 1560461.

  7. VizieR Online Data Catalog: M33 molecular clouds and young stellar clusters (Corbelli+, 2017)

    NASA Astrophysics Data System (ADS)

    Corbelli, E.; Braine, J.; Bandiera, R.; Brouillet, N.; Combes, F.; Druard, C.; Gratier, P.; Mata, J.; Schuster, K.; Xilouris, M.; Palla, F.

    2017-04-01

    Table 5 : Physical parameters for the 566 molecular clouds identified through the IRAM 30m CO J=2-1 survey of the star forming disk of M33. For each cloud the cloud type and the following properties are listed: celestial coordinates, galactocentric radius, cloud deconvolved effective radius and its uncertainty, CO(2-1) line velocity dispersion from CPROPS and its uncertainty, line velocity dispersion from a Gaussian fit, CO luminous mass and its uncertainty, and virial mass from a Gaussian fit. In the last column the identification number of the young stellar cluster candidates associated with the molecular cloud are listed. Notes: We identify up to four young stellar cluster candidates (YSCCs) associated with each molecular cloud and we list them according to the identification number of Sharma et al. (2011, Cat. J/A+A/545/A96) given also in Table 6. Table 6 : Physical parameters for the 630 young stellar cluster candidates identified via their mid-infrared emission in the star forming disk of M33. For each YSCC we list the type of source, the identified number of the molecular clouds associated with it (if any) and the corresponding cloud classes. In addition, for each YSCC we give the celestial coordinates, the bolometric, total infrared, FUV and Halpha luminosities, the estimated mass and age, the visual extinction, the galactocentric radius, the source size, and its flux at 24μm. (2 data files).

  8. New quasar survey with WIRO: Color-selection of quasar candidates behind M33

    NASA Astrophysics Data System (ADS)

    Harvey, William Bradford; Bassett, Neil; Deam, Sophie; Dixon, Don; Griffith, Emily; Lee, Daniel; Lyke, Bradley; Haze Nunez, Evan; Parziale, Ryan; Witherspoon, Catherine; Myers, Adam D.; Findlay, Joseph; Kobulnicky, Henry A.; Dale, Daniel A.

    2017-01-01

    We report new quasar candidates in the extended gaseous region of the Triangulum (M33) Galaxy as observed with WIRO (The Wyoming Infrared Observatory) in the ugri bands during the Summer of 2016. Our survey produced a sample of 14042 point sources to a limiting depth of g ≤ 21.7 in a region of ~16 square degrees, 34 of which are UVX-selected, known quasars with redshifts up to z < 2.2. Color-color plots were created using extinction-corrected magnitudes of ugri as well as NUV and W1 as taken from GALEX (Galaxy Evolution Explorer) and WISE (Wide-field Infrared Survey Explorer) respectively. Using a series of color cuts in NUV, u, g, r, i, and W1 bands, we recover high-quality quasar candidates. Based on optical colors alone we project ~30 new candidates per square degree. Spectroscopic follow-up of these candidates could yield new, bright quasars behind M33. This work is supported by the National Science Foundation under REU grant AST 1560461.

  9. A Spectroscopic Survey of Massive Stars in M31 and M33

    NASA Astrophysics Data System (ADS)

    Massey, Philip; Neugent, Kathryn F.; Smart, Brianna M.

    2016-09-01

    We describe our spectroscopic follow-up to the Local Group Galaxy Survey (LGGS) photometry of M31 and M33. We have obtained new spectroscopy of 1895 stars, allowing us to classify 1496 of them for the first time. Our study has identified many foreground stars, and established membership for hundreds of early- and mid-type supergiants. We have also found nine new candidate luminous blue variables and a previously unrecognized Wolf-Rayet star. We republish the LGGS M31 and M33 catalogs with improved coordinates, and including spectroscopy from the literature and our new results. The spectroscopy in this paper is responsible for the vast majority of the stellar classifications in these two nearby spiral neighbors. The most luminous (and hence massive) of the stars in our sample are early-type B supergiants, as expected; the more massive O stars are more rare and fainter visually, and thus mostly remain unobserved so far. The majority of the unevolved stars in our sample are in the 20-40 M ⊙ range. The spectroscopic observations reported here were obtained at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution. MMT telescope time was granted by NOAO, through the Telescope System Instrumentation Program (TSIP). TSIP is funded by the National Science Foundation. This paper uses data products produced by the OIR Telescope Data Center, supported by the Smithsonian Astrophysical Observatory.

  10. Sesamin: A Naturally Occurring Lignan Inhibits CYP3A4 by Antagonizing the Pregnane X Receptor Activation.

    PubMed

    Lim, Yun-Ping; Ma, Chia-Yun; Liu, Cheng-Ling; Lin, Yu-Hsien; Hu, Miao-Lin; Chen, Jih-Jung; Hung, Dong-Zong; Hsieh, Wen-Tsong; Huang, Jin-Ding

    2012-01-01

    Inconsistent expression and regulation of drug-metabolizing enzymes (DMEs) are common causes of adverse drug effects in some drugs with a narrow therapeutic index (TI). An important cytochrome, cytochrome P450 3A4 (CYP3A4), is predominantly regulated by a nuclear receptor, pregnane X receptor (PXR). Sesamin, a major lignan constituent in sesame seeds and oil, exhibits a variety of biological functions; however, the effect of sesamin on the modulation of CYP3A4 is not well understood. In this study, the effects of sesamin on the PXR-CYP3A4 pathway were characterized, as well as the underlying mechanisms of those effects. Sesamin potently attenuated CYP3A4 induction in a dose-dependent manner by blocking the activation of PXR. The PXR inducer-mediated inhibition of CYP3A4 was further evidenced by the ability of sesamin to attenuate the effects of several PXR ligands in the CYP3A4 reporter assay. Further mechanistic studies showed that sesamin inhibited PXR by interrupting the interacting with coregulators. These results may lead to the development of new therapeutic and dietary approaches to reduce the frequency of inducer-drug interaction. Sesamin was established as a novel inhibitor of PXR and may be useful for modulating DMEs expression and drug efficacies. Modification of CYP3A4 expression and activity by consumption of sesamin may have important implications for drug safety.

  11. The conjugated linoleic acid isomer trans-9,trans-11 is a dietary occurring agonist of liver X receptor {alpha}

    SciTech Connect

    Ecker, Josef; Liebisch, Gerhard; Patsch, Wolfgang; Schmitz, Gerd

    2009-10-30

    Conjugated linoleic acid (CLA) isomers are dietary fatty acids that modulate gene expression in many cell types. We have previously reported that specifically trans-9,trans-11 (t9,t11)-CLA induces expression of genes involved in lipid metabolism of human macrophages. To elucidate the molecular mechanism underlying this transcriptional activation, we asked whether t9,t11-CLA affects activity of liver X receptor (LXR) {alpha}, a major regulator of macrophage lipid metabolism. Here we show that t9,t11-CLA is a regulator of LXR{alpha}. We further demonstrate that the CLA isomer induces expression of direct LXR{alpha} target genes in human primary macrophages. Knockdown of LXR{alpha} with RNA interference in THP-1 cells inhibited t9,t11-CLA mediated activation of LXR{alpha} including its target genes. To evaluate the effective concentration range of t9,t11-CLA, human primary macrophages were treated with various doses of CLA and well known natural and synthetic LXR agonists and mRNA expression of ABCA1 and ABCG1 was analyzed. Incubation of human macrophages with 10 {mu}M t9,t11-CLA led to a significant modulation of ABCA1 and ABCG1 transcription and caused enhanced cholesterol efflux to high density lipoproteins and apolipoprotein AI. In summary, these data show that t9,t11-CLA is an agonist of LXR{alpha} in human macrophages and that its effects on macrophage lipid metabolism can be attributed to transcriptional regulations associated with this nuclear receptor.

  12. The down-regulation of the mitogenic fibrinogen receptor (MFR) in serum-containing medium does not occur in defined medium.

    PubMed

    Levesque, J P; Hatzfeld, A; Domart, I; Hatzfeld, J

    1990-02-01

    Normal human hemopoietic cells such as early bone marrow progenitors, or lymphoma-derived cell lines such as Raji or JM cells, possess a low-affinity receptor specific for fibrinogen. This receptor triggers a mitogenic effect. It differs from the glycoprotein IIb-IIIa which is involved in fibrinogen-induced platelet aggregation. We demonstrate here that this mitogenic fibrinogen receptor (MFR) can be internalized or reexpressed, depending on culture conditions. Internalization was temperature-dependent. At 37 degrees C in the presence of cycloheximide or actinomycin D, the half-life of cell surface MFRs was 2 h, independent of receptor occupancy. Binding of fibrinogen to the MFR resulted in a down-regulation which was fibrinogen dose-dependent. This occurred in serum-supplemented medium but not in defined medium supplemented with fatty acids. Reexpression of MFRs could be induced in 28 to 42 h by serum removal. The down-regulation of mitogenic receptors in plasma or serum could explain why normal cells do not proliferate in the peripheral blood.

  13. Detection of the Second Eclipsing High-Mass X-Ray Binary in M 33

    NASA Astrophysics Data System (ADS)

    Pietsch, Wolfgang; Haberl, Frank; Gaetz, Terrance J.; Hartman, Joel D.; Plucinsky, Paul P.; Tüllmann, Ralph; Williams, Benjamin F.; Shporer, Avi; Mazeh, Tsevi; Pannuti, Thomas G.

    2009-03-01

    Chandra data of the X-ray source [PMH2004] 47 were obtained in the ACIS Survey of M 33 (ChASeM33) in 2006. During one of the observations, the source varied from a high state to a low state and back, in two other observations it varied from a low state to respectively intermediate states. These transitions are interpreted as eclipse ingresses and egresses of a compact object in a high-mass X-ray binary (HMXB) system. The phase of mideclipse is given by HJD 245 3997.476 ± 0.006, the eclipse half angle is 30fdg6 ± 1fdg2. Adding XMM-Newton observations of [PMH2004] 47 in 2001 we determine the binary period to be 1.732479 ± 0.000027 days. This period is also consistent with ROSAT HRI observations of the source in 1994. No short-term periodicity compatible with a rotation period of the compact object is detected. There are indications for a long-term variability similar to that detected for Her X-1. During the high state the spectrum of the source is hard (power-law spectrum with photon index ~0.85) with an unabsorbed luminosity of 2 ×1037 erg s-1 (0.2-4.5 keV). We identify as an optical counterpart a V ~ 21.0 mag star with T eff>19000 K, log(g)>2.5. The Canada-France-Hawaii Telescope optical light curves for this star show an ellipsoidal variation with the same period as the X-ray light curve. The optical light curve together with the X-ray eclipse can be modeled by a compact object with a mass consistent with a neutron star or a black hole in an HMXB. However, the hard power-law X-ray spectrum favors a neutron star as the compact object in this second eclipsing X-ray binary in M 33. Assuming a neutron star with a canonical mass of 1.4 M sun and the best-fit companion temperature of 33,000 K, a system inclination i = 72° and a companion mass of 10.9 M sun are implied.

  14. From molecules to young stellar clusters: the star formation cycle across the disk of M 33

    NASA Astrophysics Data System (ADS)

    Corbelli, Edvige; Braine, Jonathan; Bandiera, Rino; Brouillet, Nathalie; Combes, Françoise; Druard, Clément; Gratier, Pierre; Mata, Jimmy; Schuster, Karl; Xilouris, Manolis; Palla, Francesco

    2017-05-01

    Aims: We study the association between giant molecular clouds (GMCs) and young stellar cluster candidates (YSCCs) to shed light on the time evolution of local star formation episodes in the nearby galaxy M 33. Methods: The CO (J = 2-1) IRAM all-disk survey was used to identify and classify 566 GMCs with masses between 2 × 104 and 2 × 106M⊙ across the whole star-forming disk of M 33. In the same area, there are 630 YSCCs that we identified using Spitzer-24 μm data. Some YSCCs are embedded star-forming sites, while the majority have GALEX-UV and Hα counterparts with estimated cluster masses and ages. Results: The GMC classes correspond to different cloud evolutionary stages: inactive clouds are 32% of the total and classified clouds with embedded and exposed star formation are 16% and 52% of the total, respectively. Across the regular southern spiral arm, inactive clouds are preferentially located in the inner part of the arm, possibly suggesting a triggering of star formation as the cloud crosses the arm. The spatial correlation between YSCCs and GMCs is extremely strong, with a typical separation of 17 pc. This is less than half the CO (2-1) beam size and illustrates the remarkable physical link between the two populations. GMCs and YSCCs follow the HI filaments, except in the outermost regions, where the survey finds fewer GMCs than YSCCs, which is most likely due to undetected clouds with low CO luminosity. The distribution of the non-embedded YSCC ages peaks around 5 Myr, with only a few being as old as 8-10 Myr. These age estimates together with the number of GMCs in the various evolutionary stages lead us to conclude that 14 Myr is the typical lifetime of a GMC in M 33 prior to cloud dispersal. The inactive and embedded phases are short, lasting about 4 and 2 Myr, respectively. This underlines that embedded YSCCs rapidly break out from the clouds and become partially visible in Hα or UV long before cloud dispersal. Full Tables 5 and 6 are only available

  15. On the nature of candidate luminous blue variables in M 33

    NASA Astrophysics Data System (ADS)

    Clark, J. S.; Castro, N.; Garcia, M.; Herrero, A.; Najarro, F.; Negueruela, I.; Ritchie, B. W.; Smith, K. T.

    2012-05-01

    Context. Luminous blue variables (LBVs) are a class of highly unstable stars that have been proposed to play a critical role in massive stellar evolution as well as being the progenitors of some of the most luminous supernovae known. However the physical processes underlying their characteristic instabilities are currently unknown. Aims: In order to provide observational constraints on this behaviour we have initiated a pilot study of the population of (candidate) LBVs in the Local Group galaxy M 33. Methods: To accomplish this we have obtained new spectra of 18 examples within M 33. These provide a baseline of ≥ 4 yr with respect to previous observations, which is well suited to identifying LBV outbursts. We also employed existing multi-epoch optical and mid-IR surveys of M 33 to further constrain the variability of the sample and search for the presence of dusty ejecta. Results: Combining the datasets reveals that spectroscopic and photometric variability appears common, although in the majority of cases further observations will be needed to distinguish between an origin for this behavour in short lived stochastic wind structure and low level photospheric pulsations or coherent long term LBV excursions. Of the known LBVs we report a hitherto unidentified excursion of M 33 Var C between 2001-5, while the transition of the WNLh star B517 to a cooler B supergiant phase between 1993-2010 implies an LBV classification. Proof-of-concept quantitative model atmosphere analysis is provided for Romano's star; the resultant stellar parameters being consistent with the finding that the LBV excursions of this star are accompanied by changes in bolometric luminosity. The combination of temperature and luminosity of two stars, the BHG [HS80] 110A and the cool hypergiant B324, appear to be in violation of the empirical Humphreys-Davidson limit. Mid-IR observations demonstrate that a number of candidates appear associated with hot circumstellar dust, although no objects as

  16. Past, present and future of the luminous variable Romano's Star in M33 .

    NASA Astrophysics Data System (ADS)

    Rossi, C.; Polcaro, V. F.; Maryeva, O.; Gualandi, R.; Nesci, R.; Chieffi, A.; Viotti, R. F.

    Analysing archival data and new spectroscopic and photometric observations we find that the luminous variable Romano's Star in the M33 galaxy (GR 290) has an historical light history somehow resembling that of classical Luminous Blue Variables (LBV), but is displaying a much hotter spectrum typical of late WN stars. From model analysis and comparison with evolutionary tracks for massive stars, we find that the star has evolved from 60 M_0 star and presently its place in the H-R diagram is close to that of WN8h stars. We argue that GR 290 has just left the LBV state and is moving towards the WN stars. A crucial aspect of this star is the significant increase of its absolute luminosity at the light maxima.

  17. Spectral Variability of the LBV star V532 in M33

    NASA Astrophysics Data System (ADS)

    Maryeva, O. V.

    2009-12-01

    We present the results of spectral monitoring of the LBV star V532 (Romano star) in the M33 galaxy. Spectroscopic data cover 15 years of observations (from 1992 to 2007) during which V532 evolved from 16 mag to 18.5 mag. Spectral data were compared with photometrical data in B band. We show that the object in maximum of brightness behaves as an emission line supergiant while in minimum V532 moves along the sequence of late WN stars. We identify about 100 spectral lines in 3700-7300 Å wavelength range. For today, our spectroscopy is the most comprehensive for this object. The velocity of the wind was derived using HeI triplet lines (360 ± 30 km s^{-1}). This value is consistent with the wind velocities of late WN. Physical parameters of the nebula around V532 are estimated.

  18. The LBV nature of Romano's star (GR 290) in M 33

    NASA Astrophysics Data System (ADS)

    Polcaro, V. F.; Gualandi, R.; Norci, L.; Rossi, C.; Viotti, R. F.

    2003-11-01

    We report the first spectroscopic study of the LBV candidate GR 290 in M 33 (``Romano's star'') taken in February 2003, showing, besides prominent hydrogen and He I emission lines, the 4630-60 Å blend and weak He II 4686 Å emission typical of Of stars. Our broad-band photometry shows that the star was observed during a phase of minimum optical luminosity, with B=17.91+/- 0.03, and a slightly positive colour index, which we tentatively attribute to an anomalous continuum energy distribution. We argue that GR 290 is indeed an LBV star presently in a high temperature phase, that should be followed - also in a short time - by ample spectroscopic and associated photometric variations. Based on observations collected at 1.52 m Cassini telescope of the Loiano Observing Station, Bologna Astronomical Observatory.

  19. An analysis of STIS HST UV spectra of M 33 early B supergiants

    NASA Astrophysics Data System (ADS)

    Urbaneja, M. A.; Herrero, A.; Kudritzki, R. P.; Bresolin, F.; Corral, L. J.; Puls, J.

    2002-05-01

    We present terminal velocities of M 33 B-supergiants, obtained from STIS HST spectra as part of our programme to investigate the Wind Momentum - Luminosity Relationship (WLR) in the Local Group. Terminal velocities are derived from their N V, C Iv, and Si Iv resonance lines in UV spectra. Comparing with IUE spectra of Galactic B-supergiants we found evidence of low metallicity in three of our objects. The terminal velocities are consistent with the corresponding values of Galactic stars, except for B-133. For this star we find a very large vinfty and a red Si Iv component deeper than the blue one, that might be an indication of binarity. The average ratio between terminal and turbulent wind velocities is 0.25, well above the value found for Galactic stars. Partly based on INES data from the IUE satellite.

  20. Velocity resolved [C ii] spectroscopy of the center and the BCLMP 302 region of M 33 (HerM 33es)

    NASA Astrophysics Data System (ADS)

    Mookerjea, B.; Israel, F.; Kramer, C.; Nikola, T.; Braine, J.; Ossenkopf, V.; Röllig, M.; Henkel, C.; van der Werf, P.; van der Tak, F.; Wiedner, M. C.

    2016-02-01

    Context. The forbidden fine structure transition of C+ at 158 μm is one of the major cooling lines of the interstellar medium (ISM). Aims: We aim to understand the contribution of the ionized, atomic, and molecular phases of the ISM to the [C ii] emission from clouds near the dynamical center and the BCLMP302 H ii region in the north of the nearby galaxy M 33 at a spatial resolution of 50 pc. Methods: We combine high-resolution [C ii] spectra taken with the HIFI spectrometer onboard the Herschel satellite with [C ii] Herschel-PACS maps and ground-based observations of CO(2-1) and H i. All data are at a common spatial resolution of 50 pc. Correlation coefficients between the integrated intensities of [C ii], CO(2-1) and H i are estimated from the velocity-integrated PACS data and from the HIFI data. We decomposed the [C ii] spectra in terms of contribution from molecular and atomic gas detected in CO(2-1) and H i, respectively. At a few positions, we estimated the contribution of ionized gas to [C ii] from the emission measure observed at radio wavelengths. Results: In both regions, the center and BCLMP302, the correlation seen in the [C ii], CO(2-1) and H i intensities from structures of all sizes is significantly higher than the highest correlation in intensity obtained when comparing only structures of the same size. The correlations between the intensities of tracers corresponding to the same velocity range as [C ii], differ from the correlation derived from PACS data. Typically, the [C ii] lines have widths intermediate between the narrower CO(2-1) and broader H i line profiles. A comparison of the spectra shows that the relative contribution of molecular and atomic gas traced by CO(2-1) and H i varies substantially between positions and depends mostly on the local physical conditions and geometry. At the positions of the H ii regions, the ionized gas contributes between 10-25% of the observed [C ii] intensity. We estimate that 11-60% and 5-34% of the [C ii

  1. On The Missing Dwarf Problem In Clusters And Around The Nearby Galaxy M33

    NASA Astrophysics Data System (ADS)

    Keenan, Olivia Charlotte

    2017-08-01

    This thesis explores possible solutions to the dwarf galaxy problem. This is a discrepancy between the number of dwarf galaxies we observe, and the number predicted from cosmological computer simulations. Simulations predict around ten times more dwarf galaxy satellites than are currently observed. I have investigated two possible solutions: dark galaxies and the low surface brightness universe. Dark galaxies are dark matter halos which contain gas, but few or no stars, hence are optically dark. As part of the Arecibo Galaxy Environment Survey I surveyed the neutral hydrogen gas around the nearby galaxy M33. I found 32 gas clouds, 11 of which are new detections. Amongst these there was one particularly interesting cloud. AGESM33-32 is ring shaped and larger than M33 itself, if at the same distance. It has a velocity width which is similar to the velocity dispersion of gas in a disk galaxy, as well as having a clear velocity gradient across it which may be due to rotation. The fact that it also currently has no observed associated stars means it is a dark galaxy candidate. Optically, dwarf galaxies may be out there, but too faint for us to detect. This means that with newer, deeper, images we may be able to unveil a large, low surface brightness, population of dwarf galaxies. However, the question remains as to how these can be distinguished from background galaxies. I have used Next Generation Virgo Survey (NGVS) data to carry out photometry on 852 Virgo galaxies in four bands. I also measured the photometric properties of galaxies on a background (non-cluster) NGVS frame. I discovered that a combination of colour, magnitude and surface brightness information could be used to identify cluster dwarf galaxies from background field galaxies. The most effective method is to use the surface brightness-magnitude relation.

  2. Activation and Desensitization of Peripheral Muscle and Neuronal Nicotinic Acetylcholine Receptors by Selected, Naturally-Occurring Pyridine Alkaloids

    PubMed Central

    Green, Benedict T.; Lee, Stephen T.; Welch, Kevin D.; Cook, Daniel; Kem, William R.

    2016-01-01

    Teratogenic alkaloids can cause developmental defects due to the inhibition of fetal movement that results from desensitization of fetal muscle-type nicotinic acetylcholine receptors (nAChRs). We investigated the ability of two known teratogens, the piperidinyl-pyridine anabasine and its 1,2-dehydropiperidinyl analog anabaseine, to activate and desensitize peripheral nAChRs expressed in TE-671 and SH-SY5Y cells. Activation-concentration response curves for each alkaloid were obtained in the same multi-well plate. To measure rapid desensitization, cells were first exposed to five potentially-desensitizing concentrations of each alkaloid in log10 molar increments from 10 nM to 100 µM and then to a fixed concentration of acetylcholine (ACh), which alone produces near-maximal activation. The fifty percent desensitization concentration (DC50) was calculated from the alkaloid concentration-ACh response curve. Agonist fast desensitization potency was predicted by the agonist potency measured in the initial response. Anabaseine was a more potent desensitizer than anabasine. Relative to anabaseine, nicotine was more potent to autonomic nAChRs, but less potent to the fetal neuromuscular nAChRs. Our experiments have demonstrated that anabaseine is more effective at desensitizing fetal muscle-type nAChRs than anabasine or nicotine and, thus, it is predicted to be more teratogenic. PMID:27384586

  3. In vivo stimulus-induced vasodilation occurs without IP3 receptor activation and may precede astrocytic calcium increase

    PubMed Central

    Nizar, Krystal; Uhlirova, Hana; Tian, Peifang; Saisan, Payam A.; Cheng, Qun; Reznichenko, Lidia; Weldy, Kimberly L.; Steed, Tyler C.; Sridhar, Vishnu B.; MacDonald, Christopher L.; Cui, Jianxia; Gratiy, Sergey L.; Sakadžić, Sava; Boas, David A.; Beka, Thomas I.; Einevoll, Gaute T.; Chen, Ju; Masliah, Eliezer; Dale, Anders M.; Silva, Gabriel A.; Devor, Anna

    2013-01-01

    Calcium-dependent release of vasoactive gliotransmitters is widely assumed to trigger vasodilation associated with rapid increases in neuronal activity. Inconsistent with this hypothesis, intact stimulus-induced vasodilation was observed in inositol 1,4,5-triphosphate (IP3) type-2 receptor (R2) knockout (KO) mice, in which the primary mechanism of astrocytic calcium increase – the release of calcium from intracellular stores following activation of an IP3-dependent pathway – is lacking. Further, our results in wild type (WT) mice indicate that in vivo onset of astrocytic calcium increase in response to sensory stimulus could be considerably delayed relative to the simultaneously measured onset of arteriolar dilation. Delayed calcium increases in WT mice were observed in both astrocytic cell bodies and perivascular endfeet. Thus, astrocytes may not play a role in the initiation of blood flow response, at least not via calcium-dependent mechanisms. Moreover, an increase in astrocytic intracellular calcium was not required for normal vasodilation in the IP3R2-KO animals. PMID:23658179

  4. Downregulation of IGF-1 receptor occurs after hepatic linage commitment during hepatocyte differentiation from human embryonic stem cells.

    PubMed

    Waraky, Ahmed; Aleem, Eiman; Larsson, Olle

    2016-09-30

    The insulin-like growth factor 1 receptor (IGF-1R) has been suggested to be involved in hepatocyte differentiation. Human hepatocyte cancer cells and stem cells are known to express IGF-1R whereas normal hepatocytes do not. In the present study we optimized a differentiation protocol and verified the different stages by established markers. The expression levels of IGF-1R and major downstream signaling proteins during differentiation from human embryonic stem cells (hESC) to mature hepatocytes were investigated. We could only demonstrate a minor decrease in IGF-1R expression during endodermal differentiation compared to hESC, but declined substantially (>50%) after hepatic lineage commitment during the hepatocyte specification and maturation stages. This downregulation was paralleled by an upregulation of ERK 1/2, AKT and insulin substrate-1. Neither inhibition nor activation of IGF-1R had any essential effect on endoderm differentiation of human embryonic stem cells. Therefore, our data suggest that IGF-1R downregulation may have a regulatory impact after initiation of hepatic lineage commitment. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Role of CCK-A receptor in the regulation of pancreatic bicarbonate secretion in conscious rats: a study in naturally occurring CCK-A receptor gene knockout rats.

    PubMed

    Miyasaka, K; Suzuki, S; Kanai, S; Masuda, M; Funakoshi, A

    1999-10-01

    Whether cholecystokinin (CCK) has a direct action on duct cells and the role of CCK-A receptor in bicarbonate secretion were examined by comparing the results obtained from OLETF (CCK-A receptor-deficient rats) and control (LETO) rats. Rats were prepared with cannulae for draining bile and pancreatic juice separately, with two duodenal cannulae and an external jugular vein cannula. The experiments were conducted without anesthesia. The responses of bicarbonate secretion to intravenous infusion of CCK, acetyl-beta-methylcholine (Ach), and 2-deoxy-D-glucose (2DG), and to intraduodenal infusion of HCl and a liquid meal were examined. To examine the synergistic effect between CCK and secretin, the effect of CCK during a background secretin infusion was examined in LETO rats. CCK did not stimulate bicarbonate secretion in either strain, nor in LETO rats with secretin infusion. When gastric acid secretion was prevented by administration of omeprazole, Ach did not increase bicarbonate secretion, but 2DG did in both strains. Intraduodenal infusion of HCI and a liquid meal significantly increased bicarbonate secretion in both strains; however, the responses were much less in OLETF than LETO rats. In conclusion, intravenous injection of CCK did not stimulate bicarbonate secretion, and the lack of CCK-A receptor decreased bicarbonate secretion in response to luminal stimulants.

  6. HST/COS Observations of Ionized Gas Accretion at the Disk–Halo Interface of M33

    NASA Astrophysics Data System (ADS)

    Zheng, Y.; Peek, J. E. G.; Werk, J. K.; Putman, M. E.

    2017-01-01

    We report the detection of accreting ionized gas at the disk–halo interface of the nearby galaxy M33. We analyze Hubble Space Telescope/Cosmic Origins Spectrograph absorption-line spectra of seven ultraviolet-bright stars evenly distributed across the disk of M33. We find Si iv absorption components consistently redshifted relative to the bulk M33's ISM absorption along all the sightlines. The Si iv detection indicates an enriched, disk-wide, ionized gas inflow toward the disk. This inflow is most likely multi-phase as the redshifted components can also be observed in ions with lower ionization states (e.g., S ii, P ii, Fe ii, Si ii). Kinematic modeling of the inflow is consistent with an accreting layer at the disk–halo interface of M33, which has an accretion velocity of {110}-20+15 {km} {{{s}}}-1 at a distance of {1.5}-1.0+1.0 kpc above the disk. The modeling indicates a total mass of ∼3.9 × 107 M⊙ for the accreting material at the disk–halo interface on the near side of the M33 disk, with an accretion rate of ∼2.9 M⊙ yr‑1. The high accretion rate and the level of metal enrichment suggest the inflow is likely to be the fallback of M33 gas from a galactic fountain and/or the gas pulled loosed during a close interaction between M31 and M33. Our study of M33 is the first to unambiguously reveal the existence of a disk-wide, ionized gas inflow beyond the Milky Way, providing a better understanding of gas accretion in the vicinity of a galaxy disk.

  7. Heredity and cardiometabolic risk: naturally occurring polymorphisms in the human neuropeptide Y2 receptor promoter disrupt multiple transcriptional response motifs

    PubMed Central

    Wei, Zhiyun; Zhang, Kuixing; Wen, Gen; Balasubramanian, Karthika; Shih, Peian B.; Rao, Fangwen; Friese, Ryan S.; Miramontes-Gonzalez, Jose P.; Schmid-Schoenbein, Geert W.; Kim, Hyung-Suk; Mahata, Sushil K.; O’Connor, Daniel T.

    2013-01-01

    Objectives The neuropeptide Y2 G-protein-coupled receptor (NPY2R) relays signals from PYY or neuropeptide Y toward satiety and control of body mass. Targeted ablation of the NPY2R locus in mice yields obesity, and studies of NPY2R promoter genetic variation in more than 10 000 human participants indicate its involvement in control of obesity and BMI. Here we searched for genetic variation across the human NPY2R locus and probed its functional effects, especially in the proximal promoter. Methods and results Twin pair studies indicated substantial heritability for multiple cardiometabolic traits, including BMI, SBP, DBP, and PYY, an endogenous agonist at NPY2R. Systematic polymorphism discovery by resequencing across NPY2R uncovered 21 genetic variants, 10 of which were common [minor allele frequency (MAF) >5%], creating one to two linkage disequilibrium blocks in multiple biogeographic ancestries. In vivo, NPY2R haplotypes were associated with both BMI (P =3.75E–04) and PYY (P =4.01E–06). Computational approaches revealed that proximal promoter variants G-1606A, C-599T, and A-224G disrupt predicted IRF1 (A>G), FOXI1 (T>C), and SNAI1 (A>G) response elements. In neuroendocrine cells transfected with NPY2R promoter/luciferase reporter plasmids, all three variants and their resulting haplotypes influenced transcription (G-1606A, P <2.97E–06; C-599T, P <1.17E–06; A-224G, P <2.04E–06), and transcription was differentially augmented or impaired by coexpression of either the cognate full-length transcription factors or their specific siRNAs at each site. Endogenous expression of transcripts for NPY2R, IRF1, and SNAI1 was documented in neuroendocrine cells, and the NPY2R mRNA was differentially expressed in two neuroendocrine tissues (adrenal gland, brainstem) of a rodent model of hypertension and the metabolic syndrome, the spontaneously hypertensive rat. Conclusion We conclude that common genetic variation in the proximal NPY2R promoter influences transcription

  8. VizieR Online Data Catalog: Multi-resolution images of M33 (Boquien+, 2015)

    NASA Astrophysics Data System (ADS)

    Boquien, M.; Calzetti, D.; Aalto, S.; Boselli, A.; Braine, J.; Buat, V.; Combes, F.; Israel, F.; Kramer, C.; Lord, S.; Relano, M.; Rosolowsky, E.; Stacey, G.; Tabatabaei, F.; van der Tak, F.; van der Werf, P.; Verley, S.; Xilouris, M.

    2015-02-01

    The FITS file contains maps of the flux in star formation tracing bands, maps of the SFR, maps of the attenuation in star formation tracing bands, and a map of the stellar mass of M33, each from a resolution of 8"/pixel to 512"/pixel. The FUV GALEX data from NGS were obtained directly from the GALEX website through GALEXVIEW. The observation was carried out on 25 November 2003 for a total exposure time of 3334s. Hα+[NII] observations were carried out in November 1995 on the Burrel Schmidt telescope at Kitt Peak National Observatory. The observations and the data processing are analysed in detail in Hoopes & Walterbos (2000ApJ...541..597H). The Spitzer IRAC 8um image sensitive to the emission of Polycyclic Aromatic Hydrocarbons (PAH) and the MIPS 24um image sensitive to the emission of Very Small Grains (VSG) were obtained from the NASA Extragalactic Database and have been analysed by Hinz et al. (2004ApJS..154..259H) and Verley et al. (2007A&A...476.1161V, Cat. J/A+A/476/1161). The PACS data at 70um and 100um, which are sensitive to the warm dust heated by massive stars, come from two different programmes. The 100um image was obtained in the context of the Herschel HerM33es open time key project (Kramer et al., 2010A&A...518L..67K, observation ID 1342189079 and 1342189080). The observation was carried out in parallel mode on 7 January 2010 for a duration of 6.3h. It consisted in 2 orthogonal scans at a speed of 20"/s, with a leg length of 7'. The 70um image was obtained as a follow-up open time cycle 2 programme (OT2mboquien4, observation ID 1342247408 and 1342247409). M33 was scanned on 25 June 2012 at a speed of 20"/s in 2 orthogonal directions over 50' with 5 repetitions of this scheme in order to match the depth of the 100um image. The total duration of the observation was 9.9h. The cube, cube.fits files, contains 16 extensions: * FUV * HALPHA * 8 * 24 * 70 * 100 * SFR_FUV * SFR_HALPHA * SFR_24 * SFR_70 * SFR_100 * SFRFUV24 * SFRHALPHA24 * A_FUV * A

  9. Luminous and Variable Stars in M31 and M33. V. The Upper HR Diagram

    NASA Astrophysics Data System (ADS)

    Humphreys, Roberta M.; Davidson, Kris; Hahn, David; Martin, John C.; Weis, Kerstin

    2017-07-01

    We present HR diagrams for the massive star populations in M31 and M33, including several different types of emission-line stars: the confirmed luminous blue variables (LBVs), candidate LBVs, B[e] supergiants, and the warm hypergiants. We estimate their apparent temperatures and luminosities for comparison with their respective massive star populations and evaluate the possible relationships of these different classes of evolved, massive stars, and their evolutionary state. Several of the LBV candidates lie near the LBV/S Dor instability strip that supports their classification. Most of the B[e] supergiants, however, are less luminous than the LBVs. Many are very dusty with the infrared flux contributing one-third or more to their total flux. They are also relatively isolated from other luminous OB stars. Overall, their spatial distribution suggests a more evolved state. Some may be post-RSGs (red supergiants) like the warm hypergiants, and there may be more than one path to becoming a B[e] star. There are sufficient differences in the spectra, luminosities, spatial distribution, and the presence or lack of dust between the LBVs and B[e] supergiants to conclude that one group does not evolve into the other.

  10. First images of water vapor masers in the galaxy M33

    NASA Technical Reports Server (NTRS)

    Greenhill, L. J.; Moran, J. M.; Reid, M. J.; Gwinn, C. R.; Menten, K. M.

    1990-01-01

    The first successful VLBI observations of 10 extragalactic H2O masers in the M33 galaxy are reported. A spectral-line VLBI synthesis map is constructed, the first of any extragalactic H2O maser sources. The map has the lowest noise of any K-band spectral line VLBI map yet produced. The maser emission extends over about 300 milliarcseconds and is divided into 14 distinct spatial components, the strongest of which has a correlated flux density of about 0.7 Jy. The relative positions of some of these components are determined accurately enough to provide first-epoch measurements for proper motion studies. The characteristics of the maser are similar to those of the most powerful maser in the Galaxy, W49N. A compact H II region is found close to the maser which is 1 pc in diameter and whose emission measure is about 6 x 10 to the 7th pc/cm exp 6. This region is the compact component of a more extended H II complex that extends over about 100 pc.

  11. A search for globular clusters in more remote areas around M31 and M33 II

    SciTech Connect

    Di Tullio Zinn, Graziella; Zinn, Robert

    2014-04-01

    Using the Sloan Digital Sky Survey (SDSS), ∼900 deg{sup 2} of the sky surrounding M31 and M33 have been searched for globular clusters (GCs) that through galaxy interaction have become unbound from their parent systems and M31 (hence, intergalactic globular clusters, IGCs). This search reached a maximum of ∼500 kpc in projected galactocentric distance (R {sub gc}) from M31. Visual examination of 283,871 SDSS cutout images and of 1143 fits images yielded 320 candidates. This sample was reduced to six GCs and one likely candidate by excluding galaxies on the basis of combinations of their optical, ultraviolet, and infrared colors from the SDSS, the Galaxy Evolution Explorer satellite, and the Wide-field Infrared Survey Explorer satellite, as well as their photometric redshifts from the SDSS. Since these seven objects have 14 kpc ≤ R {sub gc} ≤ 137 kpc, they are more likely to be GCs in the halo of M31 than IGCs. They are all 'classical' as opposed to 'extended' GCs, and they provide further evidence that the remote halo of M31 (R {sub gc} ≥ 50 kpc) contains more GCs of all types and, in particular, far more 'classical' ones than the remote halo of the Milky Way.

  12. Ultraviolet spectroscopy of the brightest supergiants in M31 and M33

    NASA Technical Reports Server (NTRS)

    Humphreys, R. M.; Blaha, C.; Dodorico, S.; Gull, T. R.; Benevenuti, P.

    1983-01-01

    Ultraviolet spectroscopy from the IUE, in combination with groundbased visual and infrared photometry, are to determine the energy distributions of the luminous blue variables, the Hubble-Sandage variables, in M31 and M33. The observed energy distributions, especially in the ultraviolet, show that these stars are suffering interstellar reddening. When corrected for interstellar extinction, the integrated energy distributions yield the total luminosities and black body temperatures of the stars. The resulting bolometric magnitudes and temperatures confirm that these peculiar stars are indeed very luminous, hot stars. They occupy the same regions of the sub B01 vs. log T sub e diagram as do eta Car, P Cyg and S Dor in our galaxy and the LMC. Many of the Hubble-Sandage variables have excess infrared radiation which is attributed to free-free emission from their extended atmospheres. Rough mass loss estimates from the infrared excess yield rates of 0.00001 M sub annual/yr. The ultraviolet spectra of the H-S variables are also compared with similar spectra of eta Car, P Cyg and S For.

  13. A VLA Search for Radio Signals from M31 and M33

    NASA Astrophysics Data System (ADS)

    Gray, Robert H.; Mooley, Kunal

    2017-03-01

    Observing nearby galaxies would facilitate the search for artificial radio signals by sampling several billions of stars simultaneously, but few efforts have been made to exploit this opportunity. An added attraction is that the Milky Way is the second largest member of the Local Group, so our galaxy might be a probable target for hypothetical broadcasters in nearby galaxies. We present the first relatively high spectral resolution (<1 kHz) 21 cm band search for intelligent radio signals of complete galaxies in the Local Group with the Jansky VLA, observing the galaxies M31 (Andromeda) and M33 (Triangulum)—the first and third largest members of the group, respectively—sampling more stars than any prior search of this kind. We used 122 Hz channels over a 1 MHz spectral window in the target galaxy velocity frame of reference, and 15 Hz channels over a 125 kHz window in our local standard of rest. No narrowband signals were detected above a signal-to-noise ratio of 7, suggesting the absence of continuous narrowband flux greater than approximately 0.24 and 1.33 Jy in the respective spectral windows illuminating our part of the Milky Way during our observations in 2014 December and 2015 January. This is also the first study in which the upgraded VLA has been used for SETI.

  14. The 2006 hot phase of Romano's star (GR 290) in M 33

    NASA Astrophysics Data System (ADS)

    Viotti, R. F.; Galleti, S.; Gualandi, R.; Montagni, F.; Polcaro, V. F.; Rossi, C.; Norci, L.

    2007-03-01

    Context: Understanding the nature of the instabilities of LBVs is important to understand the late evolutionary stages of very massive stars. Aims: We investigate the long term, S Dor-type variability of the luminous blue variable GR 290 (Romano's star) in M 33, and its 2006 minimum phase. Methods: New spectroscopic and photometric data taken in November and December 2006 were employed in conjunction with already published data on GR 290 to derive the physical structure of GR 290 in different phases and the time scale of the variability. Results: We find that by the end of 2006, GR 290 had reached the deepest visual minimum so far recorded. Its present spectrum resembles closely that of the Of/WN9 stars, and is the hottest so far recorded in this star (and in any LBV as well), while its visual brightness decreased by about 1.4 mag. Conclusions: . This first spectroscopic record of GR 290 during a minimum phase confirms that, similarly to AG Car and other LBVs, the star is subject to ample S Dor-type variations, being hotter at minimum, suggesting that the variations take place at constant bolometric luminosity. Based on observations collected with the 1.52 m Cassini telescope of the Bologna Astronomical Observatory.

  15. New Cepheid distances to nearby galaxies based on BVRI CCD photometry. II - The local group galaxy M33

    NASA Technical Reports Server (NTRS)

    Freedman, Wendy L.; Wilson, Christine D.; Madore, Barry F.

    1991-01-01

    A true distance modulus to the nearby spiral galaxy M33 has been determined based on CCD photometry obtained at BVRI wavelengths. M33 is presently one of five nearby galaxies used in the calibration of the IR Tully-Fisher relation, and thereby in the determination of the Hubble constant. Using period-luminosity relations at several wavelengths offers the advantage that the distance moduli derived can be corrected for the effects of interstellar extinction. These data indicate that there is internal reddening affecting the Cepheid photometry in M33 which must be accounted for if a true distance modulus is to be obtained for this galaxy. Adopting a true distance modulus to the LMC of 18.5 mag, the new CCD data yield a true distance to M33 of 24.64 + or - 0.09 mag, corresponding to a linear distance of 840 kpc. A mean value of the total color excess (foreground and internal) for the Cepheids in M33 is estimated to be E(B - V) = 0.10 + or - 0.09 mag, assuming a value for the total mean LMC Cepheid color excess of 0.10 mag.

  16. New Cepheid distances to nearby galaxies based on BVRI CCD photometry. II - The local group galaxy M33

    NASA Technical Reports Server (NTRS)

    Freedman, Wendy L.; Wilson, Christine D.; Madore, Barry F.

    1991-01-01

    A true distance modulus to the nearby spiral galaxy M33 has been determined based on CCD photometry obtained at BVRI wavelengths. M33 is presently one of five nearby galaxies used in the calibration of the IR Tully-Fisher relation, and thereby in the determination of the Hubble constant. Using period-luminosity relations at several wavelengths offers the advantage that the distance moduli derived can be corrected for the effects of interstellar extinction. These data indicate that there is internal reddening affecting the Cepheid photometry in M33 which must be accounted for if a true distance modulus is to be obtained for this galaxy. Adopting a true distance modulus to the LMC of 18.5 mag, the new CCD data yield a true distance to M33 of 24.64 + or - 0.09 mag, corresponding to a linear distance of 840 kpc. A mean value of the total color excess (foreground and internal) for the Cepheids in M33 is estimated to be E(B - V) = 0.10 + or - 0.09 mag, assuming a value for the total mean LMC Cepheid color excess of 0.10 mag.

  17. Internalization of Tissue Factor-Rich Microvesicles by Platelets Occurs Independently of GPIIb-IIIa, and Involves CD36 Receptor, Serotonin Transporter and Cytoskeletal Assembly.

    PubMed

    Lopez-Vilchez, Irene; Diaz-Ricart, Maribel; Galan, Ana M; Roque, Merce; Caballo, Carolina; Molina, Patricia; White, James G; Escolar, Gines

    2016-02-01

    Platelets are important in hemostasis, but also detect particles and pathogens in the circulation. Phagocytic and endocytic activities of platelets are widely recognized; however, receptors and mechanisms involved remain poorly understood. We previously demonstrated that platelets internalize and store phospholipid microvesicles enriched in human tissue factor (TF+MVs) and that platelet-associated TF enhances thrombus formation at sites of vascular damage. Here, we investigate the mechanisms implied in the interactions of TF+MVs with platelets and the effects of specific inhibitory strategies. Aggregometry and electron microscopy were used to assess platelet activation and TF+MVs uptake. Cytoskeletal assembly and activation of phosphoinositide 3-kinase (PI3K) and RhoA were analyzed by western blot and ELISA. Exposure of platelets to TF+MVs caused reversible platelet aggregation, actin polymerization and association of contractile proteins to the cytoskeleton being maximal at 1 min. The same kinetics were observed for activation of PI3K and translocation of RhoA to the cytoskeleton. Inhibitory strategies to block glycoprotein IIb-IIIa (GPIIb-IIIa), scavenger receptor CD36, serotonin transporter (SERT) and PI3K, fully prevented platelet aggregation by TF+MVs. Ultrastructural techniques revealed that uptake of TF+MVs was efficiently prevented by anti-CD36 and SERT inhibitor, but only moderately interfered by GPIIb-IIIa blockade. We conclude that internalization of TF+MVs by platelets occurs independently of receptors related to their main hemostatic function (GPIIb-IIIa), involves the scavenger receptor CD36, SERT and engages PI3-Kinase activation and cytoskeletal assembly. CD36 and SERT appear as potential therapeutic targets to interfere with the association of TF+MVs with platelets and possibly downregulate their prothrombotic phenotype.

  18. Star formation in M 33: the radial and local relations with the gas

    NASA Astrophysics Data System (ADS)

    Verley, S.; Corbelli, E.; Giovanardi, C.; Hunt, L. K.

    2010-02-01

    Aims: In the Local Group spiral galaxy M 33, we investigate the correlation between the star formation rate (SFR) surface density, Σ_SFR, and the gas density Σ_gas (molecular, atomic, and total). We also explore whether there are other physical quantities, such as the hydrostatic pressure and dust optical depth, which establish a good correlation with Σ_SFR. Methods: We use the Hα, far-ultraviolet (FUV), and bolometric emission maps to infer the SFR locally at different spatial scales, and in radial bins using azimuthally averaged values. Most of the local analysis is done using the highest spatial resolution allowed by gas surveys, 180 pc. The Kennicutt-Schmidt (KS) law, Σ_SFR ∝ Σ_gas^n is analyzed by three statistical methods. Results: At all spatial scales, with Hα emission as a SFR tracer, the KS indices n are always steeper than those derived with the FUV and bolometric emissions. We attribute this to the lack of Hα emission in low luminosity regions where most stars form in small clusters with an incomplete initial mass function at their high mass end. For azimuthally averaged values the depletion timescale for the molecular gas is constant, and the KS index is n_H_2=1.1 ±0.1. Locally, at a spatial resolution of 180 pc, the correlation between Σ_SFR and Σ_gas is generally poor, even though it is tighter with the molecular and total gas than with the atomic gas alone. Considering only positions where the CO J=1-0 line is above the 2-σ detection threshold and taking into account uncertainties in Σ_H_2 and Σ_SFR, we obtain a steeper KS index than obtained with radial averages: n_H_2=2.22 ±0.07 (for FUV and bolometric SFR tracers), flatter than that relative to the total gas (n_Htot=2.59 ±0.05). The gas depletion timescale is therefore larger in regions of lower Σ_SFR. Lower KS indices (n_H_2=1.46 ±0.34 and n_H_2=1.12) are found using different fitting techniques, which do not account for individual position uncertainties. At coarser spatial

  19. Monitoring luminous yellow massive stars in M 33: new yellow hypergiant candidates

    NASA Astrophysics Data System (ADS)

    Kourniotis, M.; Bonanos, A. Z.; Yuan, W.; Macri, L. M.; Garcia-Alvarez, D.; Lee, C.-H.

    2017-05-01

    Context. The evolution of massive stars surviving the red supergiant (RSG) stage remains unexplored due to the rarity of such objects. The yellow hypergiants (YHGs) appear to be the warm counterparts of post-RSG classes located near the Humphreys-Davidson upper luminosity limit, which are characterized by atmospheric instability and high mass-loss rates. Aims: We aim to increase the number of YHGs in M 33 and thus to contribute to a better understanding of the pre-supernova evolution of massive stars. Methods: Optical spectroscopy of five dust-enshrouded yellow supergiants (YSGs) selected from mid-IR criteria was obtained with the goal of detecting evidence of extensive atmospheres. We also analyzed BVIc photometry for 21 of the most luminous YSGs in M 33 spanning approximately nine years to identify changes in the spectral type that are expected based on the few well-studied YHGs. To explore the properties of circumstellar dust, we performed spectral energy distribution fitting of multi-band photometry of the 21 YSGs. We additionally conducted K-band spectroscopy of the YHG candidate B324 in search of processed ejected material. Results: We find three luminous YSGs in our sample, stars 2, 6 and 13, with log L/L⊙ ≳ 5.35 to be YHG candidates, as they are surrounded by hot dust and are enshrouded within extended, cold dusty envelopes. Our spectroscopy of star 2 shows emission of more than one Hα component, as well as emission of Ca ii and [N ii], implying an extended atmospheric structure. In addition, the long-term monitoring of the star reveals a dimming in the visual light curve of amplitude larger than 0.5 mag that caused an apparent drop in the temperature that exceeded 500 K. We suggest the observed variability to be analogous to that of the Galactic YHG ρ Cas. We further support the post-RSG classification of N125093 and B324 instead of being LBVs in outburst. Five less luminous YSGs are suggested as post-RSG candidates showing evidence of hot or

  20. Molecular and atomic gas in the Local Group galaxy M 33

    NASA Astrophysics Data System (ADS)

    Gratier, P.; Braine, J.; Rodriguez-Fernandez, N. J.; Schuster, K. F.; Kramer, C.; Xilouris, E. M.; Tabatabaei, F. S.; Henkel, C.; Corbelli, E.; Israel, F.; van der Werf, P. P.; Calzetti, D.; Garcia-Burillo, S.; Sievers, A.; Combes, F.; Wiklind, T.; Brouillet, N.; Herpin, F.; Bontemps, S.; Aalto, S.; Koribalski, B.; van der Tak, F.; Wiedner, M. C.; Röllig, M.; Mookerjea, B.

    2010-11-01

    We present high-resolution large-scale observations of the molecular and atomic gas in the Local Group galaxy M 33. The observations were carried out using the HEterodyne Receiver Array (HERA) at the 30 m IRAM telescope in the CO(2-1) line, achieving a resolution of 12” × 2.6 km s-1, enabling individual giant molecular clouds (GMCs) to be resolved. The observed region is 650 square arcminutes mainly along the major axis and out to a radius of 8.5 kpc, and covers entirely the 2' × 40' radial strip observed with the HIFI and PACS Spectrometers as part of the HERM33ES Herschel key program. The achieved sensitivity in main-beam temperature is 20-50 mK at 2.6 km s-1 velocity resolution. The CO(2-1) luminosity of the observed region is 1.7±0.1 × 107 K km s-1 pc2 and is estimated to be 2.8±0.3 × 107 K km s-1 pc2 for the entire galaxy, corresponding to H2 masses of 1.9 × 108 Msun and 3.3 × 108 Msun respectively (including He), calculated with N(H2)/ICO(1-0) twice the Galactic value due to the half-solar metallicity of M 33. The H i 21 cm VLA archive observations were reduced, and the mosaic was imaged and cleaned using the multi-scale task in the CASA software package, yielding a series of datacubes with resolutions ranging from 5” to 25”. The H i mass within a radius of 8.5 kpc is estimated to be 1.4 × 109 Msun. The azimuthally averaged CO surface brightness decreases exponentially with a scale length of 1.9±0.1 kpc whereas the atomic gas surface density is constant at ΣH I = 6±2 Msun pc-2 deprojected to face-on. For an N(H2)/ICO(1-0) conversion factor twice that of the Milky Way, the central kiloparsec H2 surface density is ΣH2 = 8.5±0.2 Msun pc-2. The star formation rate per unit molecular gas (SF efficiency, the rate of transformation of molecular gas into stars), as traced by the ratio of CO to Hα and FIR brightness, is constant with radius. The SFE, with a N(H2)/ICO(1-0) factor twice galactic, appears 2-4 times greater than for large spiral

  1. Characterization of endoglucanase from Paenibacillus sp. M33, a novel isolate from a freshwater swamp forest.

    PubMed

    Kanchanadumkerng, Pimpikar; Sakka, Makiko; Sakka, Kazuo; Wiwat, Chanpen

    2017-02-01

    The newly isolated Paenibacillus sp. M33 from freshwater swamp forest soil in Thailand demonstrated its potential as a cellulose degrader. One of its endoglucanase genes from Paenibacillus sp., celP, was cloned to study the molecular characteristics of its gene product. The celP gene was recognized firstly by degenerate primer designed from Paenibacillus endoglucanase gene, and subsequently identified flanking region by inverse PCR technique. The celP gene consists of an open reading frame of 1707 bp encoding for 569 amino acids including 33-amino acids signal sequence. CelP is a member of glycoside hydrolase family 5 appended with a family 46 carbohydrate-binding module. CelP from recombinant Escherichia coli was purified by affinity chromatography. SDS-PAGE analysis of purified CelP showed a protein band at about 60 kDa. The purified enzyme gave a specific CMCase activity of 0.03 μmol min(-1)  mg(-1) . It had higher activities on lichenan (0.19 μmol min(-1)  mg(-1) ) and barley β-glucan (0.14 μmol min(-1)  mg(-1) ). Maximum activity on lichenan was obtained at 50 °C, pH 5.0. CelP was stable over a pH range of 3.0-10.0 and retained 80% activity when incubated at 50 °C for 1 h. The properties of its CelP endoglucanase, especially substrate specificity, will make it useful in various biotechnological applications including biomass hydrolysis.

  2. ISO Mid-Infrared Observations of Giant HII Regions in M33

    NASA Technical Reports Server (NTRS)

    Skelton, B. P.; Waller, W. H.; Hodge, P. W.; Boulanger, F.; Cornett, R. H.; Fanelli, M. N.; Lequeux, J.; Stecher, T. P.; Viallefond, F.; Hui, Y.

    1999-01-01

    We present Infrared Space Observatory Camera (ISOCAM) Circular Variable Filter scans of three giant HII regions in M33. IC 133, NGC 595, and CC 93 span a wide range of metallicity, luminosity, nebular excitation, and infrared excess; three other emission regions (CC 43, CC 99, and a region to the northeast of the core of NGC 595) are luminous enough in the mid-infrared to be detected in the observed fields. ISOCAM CVF observations provide spatially resolved observations (5'') of 151 wavelengths between 5.1 and 16.5 microns with a spectral resolution R = 35 to 50. We observe atomic emission lines ([Ne II], [Ne III], and [S IV]), several "unidentified infrared bands" (UIBs; 6.2, 7.7, 8.6, 11.3, 12.0, and 12.7 microns), and in some cases a continuum which rises steeply at longer wavelengths. We conclude that the spectra of these three GHRs are well explained by combinations of ionized gas, PAHs, and very small grains in various proportions and with different spatial distributions. Comparisons between observed ratios of the various UIBs with model ratios indicate that the PAHs in all three of the GHRs are dehydrogenated and that the small PAHs have been destroyed in IC 133 but have survived in NGC 595 and CC 93. The [Ne III]/[Ne II] ratios observed in IC 133 and NGC 595 are consistent with their ages of 5 and 4.5 Myr, respectively; the deduced ionization parameter is higher in IC 133, consistent with its more compact region of emission.

  3. ISO Mid-Infrared Observations of Giant HII Regions in M33

    NASA Technical Reports Server (NTRS)

    Skelton, B. P.; Waller, W. H.; Hodge, P. W.; Boulanger, F.; Cornett, R. H.; Fanelli, M. N.; Lequeux, J.; Stecher, T. P.; Viallefond, F.; Hui, Y.

    1999-01-01

    We present Infrared Space Observatory Camera (ISOCAM) Circular Variable Filter scans of three giant HII regions in M33. IC 133, NGC 595, and CC 93 span a wide range of metallicity, luminosity, nebular excitation, and infrared excess; three other emission regions (CC 43, CC 99, and a region to the northeast of the core of NGC 595) are luminous enough in the mid-infrared to be detected in the observed fields. ISOCAM CVF observations provide spatially resolved observations (5'') of 151 wavelengths between 5.1 and 16.5 microns with a spectral resolution R = 35 to 50. We observe atomic emission lines ([Ne II], [Ne III], and [S IV]), several "unidentified infrared bands" (UIBs; 6.2, 7.7, 8.6, 11.3, 12.0, and 12.7 microns), and in some cases a continuum which rises steeply at longer wavelengths. We conclude that the spectra of these three GHRs are well explained by combinations of ionized gas, PAHs, and very small grains in various proportions and with different spatial distributions. Comparisons between observed ratios of the various UIBs with model ratios indicate that the PAHs in all three of the GHRs are dehydrogenated and that the small PAHs have been destroyed in IC 133 but have survived in NGC 595 and CC 93. The [Ne III]/[Ne II] ratios observed in IC 133 and NGC 595 are consistent with their ages of 5 and 4.5 Myr, respectively; the deduced ionization parameter is higher in IC 133, consistent with its more compact region of emission.

  4. THE STELLAR ARCHEOLOGY OF THE M33 DISK: RECENT STAR-FORMING HISTORY AND CONSTRAINTS ON THE TIMING OF AN INTERACTION WITH M31

    SciTech Connect

    Davidge, T. J.; Puzia, T. H. E-mail: tpuzia@gmail.com

    2011-09-10

    Images recorded with MegaCam are used to investigate the recent (t {<=} 0.25 Gyr) star-forming history (SFH) of the Local Group Sc galaxy M33. The data sample the entire star-forming disk, as well as areas immediately to the north and south of the galaxy. The properties of the stellar disk change near R{sub GC} = 8 kpc. Within this radius the luminosity function of main-sequence stars indicates that the star formation rate (SFR) has been constant with time during at least the past 250 Myr, while at larger radii the SFR has declined during this same time period. That the recent SFR in the inner disk has been constant suggests that M33 has evolved in isolation for at least the past {approx}0.5 Gyr, thereby providing a constraint on the timing of any recent interaction with M31. The color of the main-sequence ridgeline changes with radius, suggesting a gradient in extinction of size {Delta}A{sub V} /{Delta}R{sub GC} = -0.05 mag kpc{sup -1}. The fractional contribution that young stars make to the total mass of the stellar disk changes with radius, peaking near 8 kpc. Evidence is also presented of systematic spatial variations in the SFH of the disk, such that the SFR during the past 100 Myr in the southern half of the galaxy has been {approx}0.4 dex higher than in the northern half. Finally, structures with sizes spanning many kpc that contain blue objects-presumably main-sequence stars that formed during intermediate epochs-are identified near the disk boundary. It is argued that these are tidal features that were pulled from the main body of M33 and-in some cases-are the fossil remnants of star formation that occurred in an extended disk during intermediate epochs.

  5. THE CHANDRA ACIS SURVEY OF M33: X-RAY, OPTICAL, AND RADIO PROPERTIES OF THE SUPERNOVA REMNANTS

    SciTech Connect

    Long, Knox S.; Ghavamian, Parviz; Blair, William P.; Kuntz, Kip D.; Winkler, P. Frank; McNeil, Emily K.; Becker, Robert H.; Gaetz, Terrance J.; Kirshner, Robert P.; Plucinsky, Paul P.; Tuellmann, Ralph; Helfand, David J.; Saul, Destry; Hughes, John P.; Pannuti, Thomas G.; Williams, Benjamin E-mail: wpb@pha.jhu.edu

    2010-04-01

    M33 contains a large number of emission nebulae identified as supernova remnants (SNRs) based on the high [S II]:H{alpha} ratios characteristic of shocked gas. Using Chandra data from the ChASeM33 survey with a 0.35-2 keV sensitivity of {approx}2 x 10{sup 34} erg s{sup -1}, we have detected 82 of 137 SNR candidates, yielding confirmation of (or at least strongly support for) their SNR identifications. This provides the largest sample of remnants detected at optical and X-ray wavelengths in any galaxy, including the Milky Way. A spectral analysis of the seven X-ray brightest SNRs reveals that two, G98-31 and G98-35, have spectra that appear to indicate enrichment by ejecta from core-collapse supernova explosions. In general, the X-ray-detected SNRs have soft X-ray spectra compared to the vast majority of sources detected along the line of sight to M33. It is unlikely that there are any other undiscovered thermally dominated X-ray SNRs with luminosities in excess of {approx}4 x 10{sup 35} erg s{sup -1} in the portions of M33 covered by the ChASeM33 survey. We have used a combination of new and archival optical and radio observations to attempt to better understand why some objects are detected as X-ray sources and others are not. We have also developed a morphological classification scheme for the optically identified SNRs and discussed the efficacy of this scheme as a predictor of X-ray detectability. Finally, we have compared the SNRs found in M33 to those that have been observed in the Galaxy and the Magellanic Clouds. There are no close analogs of Cas A, Kepler's SNR, Tycho's SNR, or the Crab Nebula in the regions of M33 surveyed, but we have found an X-ray source with a power-law spectrum coincident with a small-diameter radio source that may be the first pulsar-wind nebula recognized in M33.

  6. The deletion of TonB-dependent receptor genes is part of the genome reduction process that occurs during adaptation of Pseudomonas aeruginosa to the cystic fibrosis lung.

    PubMed

    Dingemans, Jozef; Ye, Lumeng; Hildebrand, Falk; Tontodonati, Francesca; Craggs, Michael; Bilocq, Florence; De Vos, Daniel; Crabbé, Aurélie; Van Houdt, Rob; Malfroot, Anne; Cornelis, Pierre

    2014-06-01

    Chronic Pseudomonas aeruginosa infections are the main cause of morbidity among patients with cystic fibrosis (CF) due to persistent lung inflammation caused by interaction between this bacterium and the immune system. Longitudinal studies of clonally related isolates of a dominant CF clone have indicated that genome reduction frequently occurs during adaptation of P. aeruginosa in the CF lung. In this study, we have evaluated the P. aeruginosa population structure of patients attending the Universitair Ziekenhuis Brussel (UZ Brussel) CF reference center using a combination of genotyping methods. Although the UZ Brussel P. aeruginosa CF population is characterized by the absence of a dominant CF clone, some potential interpatient transmissions could be detected. Interestingly, one of these clones showed deletion of the alternative type I ferripyoverdine receptor gene fpvB. Furthermore, we found that several other TonB-dependent receptors are deleted as well. The genome of one potentially transmissible CF clone was sequenced, revealing large deleted regions including all type III secretion system genes and several virulence genes. Remarkably, a large number of deleted genes are shared between the P. aeruginosa CF clone described in this study and isolates belonging to the dominant Copenhagen CF DK2 clone, suggesting parallel evolution. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  7. Decrease in fibronectin occurs coincident with the increased expression of its integrin receptor alpha5beta1 in stress-deprived ligaments.

    PubMed Central

    AbiEzzi, S. S.; Foulk, R. A.; Harwood, F. L.; Akeson, W. H.; Amiel, D.

    1997-01-01

    Stress deprivation secondary to immobilization leads to atrophic changes in periarticular soft tissues. The changes in ligaments include a disorganization of collagen and cellular ultrastructure with varied biochemical alterations resulting in a functionally weaker tissue. This study tests the hypothesis that alterations in fibronectin (Fn) and the expression of its integrin receptor alpha5beta1 in ligament fibroblasts accompany the extracellular matrix remodeling which occurs in stress-deprived knee ligaments. The left knees of eighteen New Zealand white rabbits were surgically immobilized in acute flexion. Fibroblasts within three nine week and three twelve week stress-deprived anterior cruciate ligaments (ACLs) and medial collateral ligaments (MCLs) demonstrated markedly increased immunostaining for the beta1 and alpha5 integrin subunits, as compared to fibroblasts in the contralateral unoperated control ligaments. The effects of stress deprivation on the concentration of Fn was measured by competitive ELISA on the remaining twelve rabbits. Decreases in Fn of 54.0 percent and 63.7 percent occurred in the ACL after nine and twelve weeks of stress deprivation when compared to contralateral controls. The MCL had less of a decrease, losing 37.7 percent and 41.7 percent at nine and twelve weeks, respectively. These results suggest an important role for the Fn-specific integrin receptor alpha5beta1 in remodeling stress-deprived periarticular ligamentous tissue, and the importance of maintaining normal stresses on periarticular ligaments to prevent the degradation of extracellular matrix components such as Fn. Images Figure 1 Figure 2 Figure 3 PMID:9234981

  8. Common variable immunodeficiency revisited: normal generation of naturally occurring dendritic cells that respond to Toll-like receptors 7 and 9

    PubMed Central

    Taraldsrud, E; Fevang, B; Aukrust, P; Beiske, K H; Fløisand, Y; Frøland, S; Rollag, H; Olweus, J

    2014-01-01

    Patients with common variable immunodeficiency (CVID) have reduced numbers and frequencies of dendritic cells (DCs) in blood, and there is also evidence for defective activation through Toll-like receptors (TLRs). Collectively, these observations may point to a primary defect in the generation of functional DCs. Here, we measured frequencies of plasmacytoid DCs (pDCs) and myeloid DCs (mDCs) in peripheral blood of 26 CVID patients and 16 healthy controls. The results show that the patients have reduced absolute counts of both subsets. However, the decreased numbers in peripheral blood were not reflected in reduced frequencies of CD34+ pDC progenitors in the bone marrow. Moreover, studies at the single cell level showed that DCs from CVID patients and healthy controls produced similar amounts of interferon-α or interleukin-12 and expressed similar levels of activation markers in response to human cytomegalovirus and ligands for TLR-7 and TLR-9. The study represents the most thorough functional characterization to date, and the first to assess bone marrow progenitor output, of naturally occurring DCs in CVID. In conclusion, it seems unlikely that CVID is secondary to insufficient production of naturally occurring DCs or a defect in their signalling through TLR-7 or TLR-9. PMID:24237110

  9. Stimulation of α7 nicotinic acetylcholine receptor by nicotine increases suppressive capacity of naturally occurring CD4+CD25+ regulatory T cells in mice in vitro.

    PubMed

    Wang, Da-wei; Zhou, Rong-bin; Yao, Yong-ming; Zhu, Xiao-mei; Yin, Yi-mei; Zhao, Guang-ju; Dong, Ning; Sheng, Zhi-yong

    2010-12-01

    α7 Nicotinic acetylcholine receptor (α7 nAChR) has been found in several non-neuronal cells and is described as an important regulator of cellular function. Naturally occurring CD4(+)CD25(+) regulatory T cells (Tregs) are essential for the active suppression of autoimmunity. The present study investigated whether naturally occurring Tregs expressed α7 nAChR and investigated the functionary role of this receptor in controlling suppressive activity of these cells. We found that CD4(+)CD25(+) Tregs from naive C57BL/6J mice positively expressed α7 nAChR, and its activation by nicotine enhanced the suppressive capacity of Tregs. Nicotine stimulation up-regulated the expression of cytotoxic T-lymphocyte-associated antigen (CTLA)-4 and forkhead/winged helix transcription factor p3 (Foxp3) on Tregs but had no effect on the production of interleukin (IL)-10 and transforming growth factor-β1 by Tregs. In the supernatants of CD4(+)CD25(+) Tregs/CD4(+)CD25(-) T-cell cocultures, we observed a decrease in the concentration of IL-2 in nicotine-stimulated groups, but nicotine stimulation had no effect on the ratio of IL-4/interferon (IFN)-γ, which partially represented T-cell polarization. The above-mentioned effects of nicotine were reversed by a selective α7 nAChR antagonist, α-bungarotoxin. In addition, the ratio of IL-4/IFN-γ was increased by treatment with α-bungarotoxin. We conclude that nicotine might increase Treg-mediated immune suppression of lymphocytes via α7 nAChR. The effect is related to the up-regulation of CTLA-4 as well as Foxp3 expression and decreased IL-2 secretion in CD4(+)CD25(+) Tregs/CD4(+)CD25(-) T-cell coculture supernatants. α7 nAChR seems to be a critical regulator for immunosuppressive function of CD4(+)CD25(+) Tregs.

  10. Beta-adrenergic receptors support attention to extinction learning that occurs in the absence, but not the presence, of a context change

    PubMed Central

    André, Marion Agnès Emma; Wolf, Oliver T.; Manahan-Vaughan, Denise

    2015-01-01

    The noradrenergic (NA)-system is an important regulator of cognitive function. It contributes to extinction learning (EL), and in disorders where EL is impaired NA-dysfunction has been postulated. We explored whether NA acting on beta-adrenergic-receptors (β-AR), regulates EL that depends on context, but is not fear-associated. We assessed behavior in an “AAA” or “ABA” paradigm: rats were trained for 3 days in a T-maze (context-A) to learn that a reward is consistently found in the goal arm, despite low reward probability. This was followed on day 4 by EL (unrewarded), whereby in the ABA-paradigm, EL was reinforced by a context change (B), and in the AAA-paradigm, no context change occurred. On day 5, re-exposure to the A-context (unrewarded) occurred. Typically, in control “AAA” animals EL occurred on day 4 that progressed further on day 5. In control “ABA” animals, EL also occurred on day 4, followed by renewal of the previously learned (A) behavior on day 5, that was succeeded (on day 5) by extinction of this behavior, as the animals realised that no food reward would be given. Treatment with the β-AR-antagonist, propranolol, prior to EL on day 4, impaired EL in the AAA-paradigm. In the “ABA” paradigm, antagonist treatment on day 4, had no effect on extinction that was reinforced by a context change (B). Furthermore, β-AR-antagonism prior to renewal testing (on day 5) in the ABA-paradigm, resulted in normal renewal behavior, although subsequent extinction of responses during day 5 was prevented by the antagonist. Thus, under both treatment conditions, β-AR-antagonism prevented extinction of the behavior learned in the “A” context. β-AR-blockade during an overt context change did not prevent EL, whereas β-AR were required for EL in an unchanging context. These data suggest that β-AR may support EL by reinforcing attention towards relevant changes in the previously learned experience, and that this process supports extinction

  11. An atlas of H-alpha-emitting regions in M33: A systematic search for SS433 star candidates

    NASA Technical Reports Server (NTRS)

    Calzetti, Daniela; Kinney, Anne L.; Ford, Holland; Doggett, Jesse; Long, Knox S.

    1995-01-01

    We report finding charts and accurate positions for 432 compact H-alpha emitting regions in the Local Group galaxy M 33 (NGC 598), in an effort to isolate candidates for an SS433-like stellar system. The objects were extracted from narrow band images, centered in the rest-frame H-alpha (lambda 6563 A) and in the red continuum at 6100 A. The atlas is complete down to V approximately equal to 20 and includes 279 compact HII regions and 153 line emitting point-like sources. The point-like sources undoubtedly include a variety of objects: very small HII regions, early type stars with intense stellar winds, and Wolf-Rayet stars, but should also contain objects with the characteristics of SS433. This extensive survey of compact H-alpha regions in M 33 is a first step towards the identification of peculiar stellar systems like SS433 in external galaxies.

  12. Accurate Parameters for the Most Massive Stars in the Local Universe: the Brightest Eclipsing Binaries in M33

    NASA Astrophysics Data System (ADS)

    Prieto, José L.; Bonanos, Alceste; Stanek, Krzysztof

    2007-08-01

    Eclipsing binaries are the only systems that provide accurate fundamental parameters of distant stars. Currently, only a handful of accurate measurements of stars with masses between 40-80 Msun have been made. We propose to make accurate measurements of the masses, radii and luminosities of the most massive eclipsing binaries in M33. The results of this study will provide much needed constraints on theories that model the formation and evolution of massive stars and binary systems. Furthermore, it will provide vital statistics on the occurrence of massive binary twins, like the 80+80 solar masses WR 20a system and the 30+30 solar masses detached eclipsing binary in M33.

  13. A Deep XMM-Newton Survey of M33: Point-source Catalog, Source Detection, and Characterization of Overlapping Fields

    NASA Astrophysics Data System (ADS)

    Williams, Benjamin F.; Wold, Brian; Haberl, Frank; Garofali, Kristen; Blair, William P.; Gaetz, Terrance J.; Kuntz, K. D.; Long, Knox S.; Pannuti, Thomas G.; Pietsch, Wolfgang; Plucinsky, Paul P.; Winkler, P. Frank

    2015-05-01

    We have obtained a deep 8 field XMM-Newton mosaic of M33 covering the galaxy out to the D25 isophote and beyond to a limiting 0.2-4.5 keV unabsorbed flux of 5 × 10-16 erg cm-2 s-1 (L \\gt 4 × 1034 erg s-1 at the distance of M33). These data allow complete coverage of the galaxy with high sensitivity to soft sources such as diffuse hot gas and supernova remnants (SNRs). Here, we describe the methods we used to identify and characterize 1296 point sources in the 8 fields. We compare our resulting source catalog to the literature, note variable sources, construct hardness ratios, classify soft sources, analyze the source density profile, and measure the X-ray luminosity function (XLF). As a result of the large effective area of XMM-Newton below 1 keV, the survey contains many new soft X-ray sources. The radial source density profile and XLF for the sources suggest that only ˜15% of the 391 bright sources with L \\gt 3.6 × 1035 erg s-1 are likely to be associated with M33, and more than a third of these are known SNRs. The log(N)-log(S) distribution, when corrected for background contamination, is a relatively flat power law with a differential index of 1.5, which suggests that many of the other M33 sources may be high-mass X-ray binaries. Finally, we note the discovery of an interesting new transient X-ray source, which we are unable to classify.

  14. THE ABUNDANCE SCATTER IN M33 FROM H II REGIONS: IS THERE ANY EVIDENCE FOR AZIMUTHAL METALLICITY VARIATIONS?

    SciTech Connect

    Bresolin, Fabio

    2011-04-01

    Optical spectra of 25 H II regions in the inner 2 kpc of the M33 disk have been obtained with the Gemini Multi-Object Spectrograph at the Gemini North telescope. The oxygen abundance gradient measured from the detection of the [O III] {lambda}4363 auroral line displays a scatter of approximately 0.06 dex, a much smaller value than recently reported by Rosolowsky and Simon in this galaxy. The analysis of the abundances for a large sample of H II regions derived from the R{sub 23} strong-line indicator confirms that the scatter is small over the full disk of M33, consistent with the measuring uncertainties, and comparable to what is observed in other spiral galaxies. No evidence is therefore found for significant azimuthal variations in the present-day metallicity of the interstellar medium in this galaxy on spatial scales from {approx}100 pc to a few kpc. A considerable fraction of M33 H II regions with auroral line detections show spectral features revealing sources of hard ionizing radiation (such as He II emission and large [Ne III], [O III] line fluxes). Since R{sub 23} is shown to severely underestimate the oxygen abundances in such cases, care must be taken in chemical abundance studies of extragalactic H II regions based on this strong-line indicator.

  15. Extra-galactic Distances with Massive Stars: The Role of Stellar Variability in the Case of M33

    NASA Astrophysics Data System (ADS)

    Lee, Chien-Hsiu

    2017-08-01

    In modern cosmology, determining the Hubble constant (H0) using a distance ladder to percent level and comparing with the results from the Planck satellite can shed light on the nature of dark energy, physics of the neutrino, and curvature of the universe. Thanks to the endeavor of the SH0ES team, the uncertainty of the H0 has be dramatically reduced, from 10% to 2.4%, and with the promise of even reaching 1% in the near future. In this regard, it is fundamentally important to investigate the systematics. This is best done using other good independent distance indicators. One promising method is the flux-weighted gravity luminosity relation (FGLR) of the blue supergiants (BSGs). As BSGs are the brightest objects in galaxies, they can probe distances up to 10 Mpc with negligible blending effects. While the FGLR method delivered distance is in good agreement with other distance indicators, it has been shown that this method delivers greater distances in the cases of M33 and NGC 55. Here, we investigate whether the M33 distance estimate of FGLR suffers systematics from stellar variability. Using CFHT M33 monitoring data, we found that 9 out of 22 BSGs showed variability during the course of 500 days, although with amplitudes as small as 0.05 mag. This suggests that stellar variability plays a negligible role in the FGLR distance determination.

  16. A Naturally Occurring Mutation of the Opsin Gene (T4R) in Dogs Affects Glycosylation and Stability of the G Protein-coupled Receptor*

    PubMed Central

    Zhu, Li; Jang, Geeng-Fu; Jastrzebska, Beata; Filipek, Sławomir; Pearce-Kelling, Susan E.; Aguirre, Gustavo D.; Stenkamp, Ronald E.; Acland, Gregory M.; Palczewski, Krzysztof

    2005-01-01

    Rho (rhodopsin; opsin plus 11-cis-retinal) is a prototypical G protein-coupled receptor responsible for the capture of a photon in retinal photoreceptor cells. A large number of mutations in the opsin gene associated with autosomal dominant retinitis pigmentosa have been identified. The naturally occurring T4R opsin mutation in the English mastiff dog leads to a progressive retinal degeneration that closely resembles human retinitis pigmentosa caused by the T4K mutation in the opsin gene. Using genetic approaches and biochemical assays, we explored the properties of the T4R mutant protein. Employing immunoaffinity-purified Rho from affected RHOT4R/T4R dog retina, we found that the mutation abolished glycosylation at Asn2, whereas glycosylation at Asn15 was unaffected, and the mutant opsin localized normally to the rod outer segments. Moreover, we found that T4R Rho* lost its chromophore faster as measured by the decay of meta-rhodopsin II and that it was less resistant to heat denaturation. Detergent-solubilized T4R opsin regenerated poorly and interacted abnormally with the G protein transducin (Gt). Structurally, the mutation affected mainly the “plug” at the intradiscal (extracellular) side of Rho, which is possibly responsible for protecting the chromophore from the access of bulk water. The T4R mutation may represent a novel molecular mechanism of degeneration where the unliganded form of the mutant opsin exerts a detrimental effect by losing its structural integrity. PMID:15459196

  17. A naturally occurring mutation of the opsin gene (T4R) in dogs affects glycosylation and stability of the G protein-coupled receptor.

    PubMed

    Zhu, Li; Jang, Geeng-Fu; Jastrzebska, Beata; Filipek, Slawomir; Pearce-Kelling, Susan E; Aguirre, Gustavo D; Stenkamp, Ronald E; Acland, Gregory M; Palczewski, Krzysztof

    2004-12-17

    Rho (rhodopsin; opsin plus 11-cis-retinal) is a prototypical G protein-coupled receptor responsible for the capture of a photon in retinal photoreceptor cells. A large number of mutations in the opsin gene associated with autosomal dominant retinitis pigmentosa have been identified. The naturally occurring T4R opsin mutation in the English mastiff dog leads to a progressive retinal degeneration that closely resembles human retinitis pigmentosa caused by the T4K mutation in the opsin gene. Using genetic approaches and biochemical assays, we explored the properties of the T4R mutant protein. Employing immunoaffinity-purified Rho from affected RHO(T4R/T4R) dog retina, we found that the mutation abolished glycosylation at Asn(2), whereas glycosylation at Asn(15) was unaffected, and the mutant opsin localized normally to the rod outer segments. Moreover, we found that T4R Rho(*) lost its chromophore faster as measured by the decay of meta-rhodopsin II and that it was less resistant to heat denaturation. Detergent-solubilized T4R opsin regenerated poorly and interacted abnormally with the G protein transducin (G(t)). Structurally, the mutation affected mainly the "plug" at the intradiscal (extracellular) side of Rho, which is possibly responsible for protecting the chromophore from the access of bulk water. The T4R mutation may represent a novel molecular mechanism of degeneration where the unliganded form of the mutant opsin exerts a detrimental effect by losing its structural integrity.

  18. Antigenic Homology of the Inducible Ferric Citrate Receptor (FecA) of Coliform Bacteria Isolated from Herds with Naturally Occurring Bovine Intramammary Infections

    PubMed Central

    Lin, Jun; Hogan, Joseph S.; Smith, K. Larry

    1999-01-01

    Expression of ferric citrate receptor FecA by Escherichia coli and Klebsiella pneumoniae isolated from bovine mastitis was investigated. Transformant E. coli UT5600/pSV66, which produces large quantities of FecA in the presence of citrate, was constructed. The FecA of E. coli UT5600/pSV66 was purified by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis and used to prepare polyclonal antiserum in rabbits. All coliform isolates of E. coli (n = 18) and K. pneumoniae (n = 17) from naturally occurring bovine intramammary infections in five herds induced iron-regulated outer membrane proteins when grown in Trypticase soy broth containing 200 μM α-α′-dipyridyl and 1 mM citrate. Polyclonal antiserum against FecA was used in conjunction with an immunoblot technique to determine the degree of antigenic homology of FecA among isolates. In the presence of citrate, each isolate expressed FecA that reacted with the anti-FecA polyclonal antiserum. The molecular mass of FecA (∼80.5 kDa) was also highly conserved among isolates. Therefore, the ferric citrate iron transport may be induced in coliform bacteria and utilized to acquire iron in milk for survival and growth. The FecA is an attractive vaccine component for controlling coliform mastitis during the lactation period. PMID:10548594

  19. Immunohistochemical quantification of the cobalamin transport protein, cell surface receptor and Ki-67 in naturally occurring canine and feline malignant tumors and in adjacent normal tissues

    PubMed Central

    Sysel, Annette M.; Valli, Victor E.; Bauer, Joseph A.

    2015-01-01

    Cancer cells have an obligate need for cobalamin (vitamin B12) to enable DNA synthesis necessary for cellular replication. This study quantified the immunohistochemical expression of the cobalamin transport protein (transcobalamin II; TCII), cell surface receptor (transcobalamin II-R; TCII-R) and proliferation protein (Ki-67) in naturally occurring canine and feline malignant tumors, and compared these results to expression in corresponding adjacent normal tissues. All malignant tumor tissues stained positively for TCII, TCII-R and Ki-67 proteins; expression varied both within and between tumor types. Expression of TCII, TCII-R and Ki-67 was significantly higher in malignant tumor tissues than in corresponding adjacent normal tissues in both species. There was a strong correlation between TCII and TCII-R expression, and a modest correlation between TCII-R and Ki-67 expression in both species; a modest association between TCII and Ki-67 expression was present in canine tissues only. These results demonstrate a quantifiable, synchronous up-regulation of TCII and TCII-R expression by proliferating canine and feline malignant tumors. The potential to utilize these proteins as biomarkers to identify neoplastic tissues, streamline therapeutic options, evaluate response to anti-tumor therapy and monitor for recurrent disease has important implications in the advancement of cancer management for both human and companion animal patients. PMID:25633912

  20. The Outer Regions of the Nearby Sc Galaxies NGC 2403 and M33: Evidence for an Intermediate-Age Population at Large Radii

    NASA Astrophysics Data System (ADS)

    Davidge, T. J.

    2003-06-01

    Deep g'r'i'z' images obtained with the Gemini Multiobject Spectrograph (GMOS) on Gemini North are used to investigate the stellar content in the outer regions of the nearby Sc galaxies NGC 2403 and M33. The field observed in NGC 2403 covers galactocentric distances between 5 and 11 kpc perpendicular to the line of sight (RLOSGC) and 7 and 19 kpc along the plane of the disk (RdiskGC). The red giant branch (RGB) tip occurs at i'=23.6+/-0.1, and the Cepheid and RGB-tip distance scales for NGC 2403 are in good agreement. The number density of bright main-sequence stars in this field experiences a steep cutoff at RdiskGC~10 kpc, which is consistent with the expected truncation radius of the disk predicted from studies of edge-on spiral galaxies. While very young stars are restricted to RdiskGC<10 kpc, a population of bright asymptotic giant branch (AGB) stars is present throughout the entire GMOS field, indicating that star formation occurred outside of the present-day star-forming disk of NGC 2403 during intermediate epochs. The AGB stars are not in a tidal stream; in fact, the ratio of AGB stars above the RGB tip to those below the RGB tip does not change with radius, indicating that the bright AGB stars are uniformly mixed with the fainter stellar content throughout the field. The AGB luminosity function (LF) scales with r-band surface brightness over a wide range of radii throughout the main body of NGC 2403, indicating that the age distribution of stars in the outer regions of the present-day star-forming disk is not skewed to younger values than in the inner disk. Based on the color of stars on the upper portions of the RGB, it is concluded that metallicity changes across the field, with [Fe/H]=-0.8+/-0.1(random)+/-0.3(systematic) at RLOSGC=5 kpc, and [Fe/H]=-2.2+/-0.2(random)+/-0.8(systematic) at RLOSGC=11 kpc. The M33 field samples RLOSGC between 8 and 10 kpc and RdiskGC between 14 and 17 kpc. Bright AGB stars are detected in this field, and the ratio of bright

  1. The UK Infrared Telescope M 33 monitoring project - V. The star formation history across the galactic disc

    NASA Astrophysics Data System (ADS)

    Javadi, Atefeh; van Loon, Jacco Th.; Khosroshahi, Habib G.; Tabatabaei, Fatemeh; Hamedani Golshan, Roya; Rashidi, Maryam

    2017-01-01

    We have conducted a near-infrared monitoring campaign at the UK Infrared Telescope of the Local Group spiral galaxy M 33 (Triangulum). On the basis of their variability, we have identified stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. In this fifth paper of the series, we construct the birth mass function and hence derive the star formation history across the galactic disc of M 33. The star formation rate has varied between ˜0.010 ± 0.001 (˜0.012 ± 0.007) and 0.060±0.005 (0.052±0.009) M⊙ yr-1 kpc-2 statistically (systematically) in the central square kiloparsec of M 33, comparable with the values derived previously with another camera. The total star formation rate in M 33 within a galactocentric radius of 14 kpc has varied between ˜0.110 ± 0.005 (˜0.174 ± 0.060) and ˜0.560 ± 0.028 (˜0.503 ± 0.100) M⊙ yr-1 statistically (systematically). We find evidence of two epochs during which the star formation rate was enhanced by a factor of a few - one that started ˜6 Gyr ago and lasted ˜3 Gyr and produced ≥71 per cent of the total mass in stars, and one ˜250 Myr ago that lasted ˜200 Myr and formed ≤13 per cent of the mass in stars. Radial star formation history profiles suggest that the inner disc of M 33 was formed in an inside-out formation scenario. The outskirts of the disc are dominated by the old population, which may be the result of dynamical effects over many Gyr. We find correspondence to spiral structure for all stars, but enhanced only for stars younger than ˜100 Myr; this suggests that the spiral arms are transient features and not a part of a global density wave potential.

  2. VizieR Online Data Catalog: Revised LGGS UBVRI photometry of M31 and M33 stars (Massey+, 2016)

    NASA Astrophysics Data System (ADS)

    Massey, P.; Neugent, K. F.; Smart, B. M.

    2016-09-01

    The Local Group Galaxy Survey (LGGS) provides UBVRI plus interference-image photometry of luminous stars in the spiral galaxies M31 and M33, along with those found in seven dwarf systems currently forming massive stars (IC 10, NGC 6822, WLM, Sextans A and B, Pegasus, and Phoenix) with the intent of serving as a starting point for systematic exploration of the stellar content of our nearest neighbors beyond the Magellanic Clouds (MCs; Massey et al. 2006, Cat. J/AJ/131/2478; Massey ey al. 2007, Cat. J/AJ/134/2474; Massey et al. 2007, Cat. J/AJ/133/2393; Massey et al. 2011AJ....141...28M). All of the observations on which our new spectroscopy is based come from the 6.5m MMT telescope used with the 300 fiber positioner Hectospec. This instrument provides a 1° field-of-view, with a choice of two gratings: (1) a 270 line/mm blazed at 5000Å, which covers the entire visible region (3650-9200Å) at once with a resolution of ~5Å, and (2) a 600 line/mm grating blazed 6000Å, which covers 2300Å at one time at a resolution of ~2Å. The fibers have a diameter of 1.5''. The majority of the new observations reported here were obtained with the higher dispersion grating nominally centered at 4800Å but actually covering 3700-6000Å. Some additional new spectral types are those of the Wolf-Rayet stars (non-WRs) found by Neugent & Massey 2011 (Cat. J/ApJ/733/123) and Neugent et al. 2012 (Cat. J/ApJ/759/11); these data were obtained with the lower-dispersion grating, with details reported in that paper. The first year of observations were obtained during the Fall of 2009, with nominally three nights assigned (2009B-0149), but poor weather during the semester meant we obtained only four fields in M31 and one field in M33. Each observation consisted of 3*45 minute exposures. The second year (Fall 2010), two nights were nominally assigned (NOAO 2010B-0260), allowing us to observe three additional fields in M33, two with 3*45 minute exposures and one with 3*40 minute exposures. We

  3. Unmasking of CD22 Co-receptor on Germinal Center B-cells Occurs by Alternative Mechanisms in Mouse and Man.

    PubMed

    Macauley, Matthew S; Kawasaki, Norihito; Peng, Wenjie; Wang, Shui-Hua; He, Yuan; Arlian, Britni M; McBride, Ryan; Kannagi, Reiji; Khoo, Kay-Hooi; Paulson, James C

    2015-12-11

    CD22 is an inhibitory B-cell co-receptor whose function is modulated by sialic acid (Sia)-bearing glycan ligands. Glycan remodeling in the germinal center (GC) alters CD22 ligands, with as yet no ascribed biological consequence. Here, we show in both mice and humans that loss of high affinity ligands on GC B-cells unmasks the binding site of CD22 relative to naive and memory B-cells, promoting recognition of trans ligands. The conserved modulation of CD22 ligands on GC B-cells is striking because high affinity glycan ligands of CD22 are species-specific. In both species, the high affinity ligand is based on the sequence Siaα2-6Galβ1-4GlcNAc, which terminates N-glycans. The human ligand has N-acetylneuraminic acid (Neu5Ac) as the sialic acid, and the high affinity ligand on naive B-cells contains 6-O-sulfate on the GlcNAc. On human GC B-cells, this sulfate modification is lost, giving rise to lower affinity CD22 ligands. Ligands of CD22 on naive murine B-cells do not contain the 6-O-sulfate modification. Instead, the high affinity ligand for mouse CD22 has N-glycolylneuraminic acid (Neu5Gc) as the sialic acid, which is replaced on GC B-cells with Neu5Ac. Human naive and memory B-cells express sulfated glycans as high affinity CD22 ligands, which are lost on GC B-cells. In mice, Neu5Gc-containing glycans serve as high affinity CD22 ligands that are replaced by Neu5Ac-containing glycans on GC B-cells. Our results demonstrate that loss of high affinity CD22 ligands on GC B-cells occurs in both mice and humans through alternative mechanisms, unmasking CD22 relative to naive and memory B-cells.

  4. Analysis of mitogen-activated protein kinase activation by naturally occurring splice variants of TrkC, the receptor for neurotrophin-3.

    PubMed

    Gunn-Moore, F J; Williams, A G; Tavaré, J M

    1997-02-15

    TrkC is a receptor tyrosine kinase that binds neurotrophin-3 (NT-3) with high affinity. A number of naturally occurring splice variants of TrkC exist, including one (TrkC kil4) with a 14 amino acid insertion between subdomains VII and VIII of the tyrosine kinase domain. This kinase insert blocks the ability of NT-3 to stimulate neurite outgrowth in PC12 cells and proliferation in fibroblasts. The inserts also block the ability of TrkC to form a high-affinity complex with Shc and phospholipase C gamma (PLC gamma) and the activation of PtdIns 3-kinase, and attenuates the sustained activation of mitogen-activated protein kinase (MAPK). In the current study we set out to determine whether the attenuation of the activation of MAPK by the insert was the result of the inability of TrkC to activate the Shc-Ras pathway, PtdIns 3-kinase activation, PLC gamma activation, or a combination thereof. Experiments with the use of cell-permeant inhibitors argue against a major role for PLC gamma and PtdIns 3-kinase in the activation of MAPK by TrkC. The introduction of the 14 amino acid kinase insert appeared to slow the kinetics of NT-3-stimulated Shc phosphorylation and Shc-Grb2 association and reduce their magnitude; an effect which was associated with a delayed, and only transient, activation of MAPK. Taken together, our data suggest that the apparent defect in MAPK activation caused by the kinase insert may result predominantly from an inhibition of high-affinity Shc binding, although a role for PLC gamma and PtdIns 3-kinase cannot be completely excluded.

  5. Naturally occurring Toll-like receptor 11 (TLR11) and Toll-like receptor 12 (TLR12) polymorphisms are not associated with Toxoplasma gondii infection in wild wood mice.

    PubMed

    Morger, Jennifer; Bajnok, Jaroslav; Boyce, Kellyanne; Craig, Philip S; Rogan, Michael T; Lun, Zhao-Rong; Hide, Geoff; Tschirren, Barbara

    2014-08-01

    Toxoplasma gondii is a highly successful parasite with a worldwide prevalence. Small rodents are the main intermediate hosts, and there is growing evidence that T. gondii modifies their behaviour. Chronically infected rodents show impaired learning capacity, enhanced activity, and, most importantly, a reduction of the innate fear towards cat odour. This modification of host behaviour ensures a successful transmission of T. gondii from rodents to felids, the definitive hosts of the parasite. Given the negative fitness consequences of this behavioural manipulation, as well as an increased mortality during the acute phase of infection, we expect rodents to evolve potent resistance mechanisms that prevent or control infection. Indeed, studies in laboratory mice have identified candidate genes for T. gondii resistance. Of particular importance appear to be the innate immune receptors Toll-like receptor 11 (TLR11) and Toll-like receptor 12 (TLR12), which recognise T. gondii profilin and initiate immune responses against the parasite. Here we analyse the genetic diversity of TLR11 and TLR12 in a natural population of wood mice (Apodemus sylvaticus), and test for associations between TLR11 and TLR12 polymorphisms and T. gondii infection, as well as for epistatic interactions between TLR11 and TLR12 on infection status. We found that both TLR11 and TLR12 were polymorphic in wood mice, with four and nine amino acid haplotypes, respectively. However, we found no evidence that TLR11 or TLR12 genotypes or haplotypes were significantly associated with Toxoplasma infection. Despite the importance of TLR11 and TLR12 in T. gondii recognition and immune defence initiation, naturally occurring polymorphisms at TLR11 and TLR12 thus appear to play a minor role in mediating qualitative resistance to T. gondii in natural host populations of A. sylvaticus. This highlights the importance of assessing the role of candidate genes for parasite resistance identified in a laboratory setting in

  6. The supernova progenitor mass distributions of M31 and M33: further evidence for an upper mass limit

    SciTech Connect

    Jennings, Zachary G.; Weisz, Daniel R.; Williams, Benjamin F.; Dalcanton, Julianne J.; Gilbert, Karoline M.; Fouesneau, Morgan; Murphy, Jeremiah W.; Dolphin, Andrew E. E-mail: adolphin@raytheon.com

    2014-11-10

    Using Hubble Space Telescope photometry to measure star formation histories, we age-date the stellar populations surrounding supernova remnants (SNRs) in M31 and M33. We then apply stellar evolution models to the ages to infer the corresponding masses for their supernova progenitor stars. We analyze 33 M33 SNR progenitors and 29 M31 SNR progenitors in this work. We then combine these measurements with 53 previously published M31 SNR progenitor measurements to bring our total number of progenitor mass estimates to 115. To quantify the mass distributions, we fit power laws of the form dN/dM∝M {sup –α}. Our new larger sample of M31 progenitors follows a distribution with α=4.4{sub −0.4}{sup +0.4}, and the M33 sample follows a distribution with α=3.8{sub −0.5}{sup +0.4}. Thus both samples are consistent within the uncertainties, and the full sample across both galaxies gives α=4.2{sub −0.3}{sup +0.3}. Both the individual and full distributions display a paucity of massive stars when compared to a Salpeter initial mass function, which we would expect to observe if all massive stars exploded as SN that leave behind observable SNR. If we instead fix α = 2.35 and treat the maximum mass as a free parameter, we find M {sub max} ∼ 35-45 M {sub ☉}, indicative of a potential maximum cutoff mass for SN production. Our results suggest that either SNR surveys are biased against finding objects in the youngest (<10 Myr old) regions, or the highest mass stars do not produce SNe.

  7. VizieR Online Data Catalog: Variable stars in M31 & M33. III. YSGs & RSGs (Gordon+, 2016)

    NASA Astrophysics Data System (ADS)

    Gordon, M. S.; Humphreys, R. M.; Jones, T. J.

    2016-08-01

    Our targets were primarily selected from the published surveys of M31 and M33 for yellow and red supergiants (Drout+ 2009, J/ApJ/703/441; 2012, J/ApJ/750/97; Massey+ 2009, J/ApJ/703/420). Their red and yellow candidates were all chosen from the Local Group Galaxies Survey (LGGS; Massey+ 2007, J/AJ/133/2393). In addition to the 120 and 135 YSG candidates from the Drout/Massey catalogs of M31 and M33, respectively, we include 18 confirmed YSGs from Humphreys+ (2014, J/ApJ/790/48, Paper II), seven warm hypergiants from Paper I (Humphreys+, 2013ApJ...773...46H), 39 Hα emission stars with intermediate colors from the survey by Valeev+ (2010AstBu..65..140V), and seven Hα emission sources from an unpublished survey by K. Weis (see Paper II). With these catalogs, we assembled a final target list of 124 and 165 candidate YSGs (after cross-identification among the listed works) for spectroscopy from M31 and M33. See section 2.1 for further explanations. Our spectra of the yellow supergiant (YSG) candidates were obtained with the Hectospec Multi-Object Spectrograph on the MMT at Mount Hopkins over several observing sessions in 2013 Sep-Oct, 2014 Nov, and 2015 Sep (R~2000 for blue or ~3600 for red spectra). We did not obtain follow-up spectroscopy of the red supergiant (RSG) candidates; our discussion of them instead relies on published photometry and analysis of their SEDs for circumstellar dust (see Section 4). (8 data files).

  8. The Abundance Scatter in M33 from H II Regions: Is There Any Evidence for Azimuthal Metallicity Variations?

    NASA Astrophysics Data System (ADS)

    Bresolin, Fabio

    2011-04-01

    Optical spectra of 25 H II regions in the inner 2 kpc of the M33 disk have been obtained with the Gemini Multi-Object Spectrograph at the Gemini North telescope. The oxygen abundance gradient measured from the detection of the [O III] λ4363 auroral line displays a scatter of approximately 0.06 dex, a much smaller value than recently reported by Rosolowsky & Simon in this galaxy. The analysis of the abundances for a large sample of H II regions derived from the R 23 strong-line indicator confirms that the scatter is small over the full disk of M33, consistent with the measuring uncertainties, and comparable to what is observed in other spiral galaxies. No evidence is therefore found for significant azimuthal variations in the present-day metallicity of the interstellar medium in this galaxy on spatial scales from ~100 pc to a few kpc. A considerable fraction of M33 H II regions with auroral line detections show spectral features revealing sources of hard ionizing radiation (such as He II emission and large [Ne III], [O III] line fluxes). Since R 23 is shown to severely underestimate the oxygen abundances in such cases, care must be taken in chemical abundance studies of extragalactic H II regions based on this strong-line indicator. 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 Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  9. Observations of M31 and M33 with the Fermi Large Area Telescope: A Galactic Center Excess in Andromeda?

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Albert, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiaro, G.; Ciprini, S.; Costanza, F.; Cutini, S.; D’Ammando, F.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Lalla, N.; Di Mauro, M.; Di Venere, L.; Favuzzi, C.; Funk, S.; Fusco, P.; Gargano, F.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Green, D.; Grenier, I. A.; Guillemot, L.; Guiriec, S.; Hayashi, K.; Hou, X.; Jóhannesson, G.; Kamae, T.; Knödlseder, J.; Kong, A. K. H.; Kuss, M.; La Mura, G.; Larsson, S.; Latronico, L.; Li, J.; Longo, F.; Loparco, F.; Lubrano, P.; Maldera, S.; Malyshev, D.; Manfreda, A.; Martin, P.; Mazziotta, M. N.; Michelson, P. F.; Mirabal, N.; Mitthumsiri, W.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Negro, M.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Persic, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Principe, G.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, O.; Sánchez-Conde, M.; Sgrò, C.; Simone, D.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Tanaka, K.; Tibaldo, L.; Torres, D. F.; Troja, E.; Uchiyama, Y.; Wang, J. C.; Wood, K. S.; Wood, M.; Zaharijas, G.; Zhou, M.

    2017-02-01

    The Fermi Large Area Telescope (LAT) has opened the way for comparative studies of cosmic rays (CRs) and high-energy objects in the Milky Way (MW) and in other, external, star-forming galaxies. Using 2 yr of observations with the Fermi LAT, Local Group galaxy M31 was detected as a marginally extended gamma-ray source, while only an upper limit has been derived for the other nearby galaxy M33. We revisited the gamma-ray emission in the direction of M31 and M33 using more than 7 yr of LAT Pass 8 data in the energy range 0.1{--}100 {GeV}, presenting detailed morphological and spectral analyses. M33 remains undetected, and we computed an upper limit of 2.0× {10}-12 {erg} {{cm}}-2 {{{s}}}-1 on the 0.1{--}100 {GeV} energy flux (95% confidence level). This revised upper limit remains consistent with the observed correlation between gamma-ray luminosity and star formation rate tracers and implies an average CR density in M33 that is at most half of that of the MW. M31 is detected with a significance of nearly 10σ . Its spectrum is consistent with a power law with photon index {{Γ }}=2.4+/- {0.1}{stat+{syst}} and a 0.1{--}100 {GeV} energy flux of (5.6+/- {0.6}{stat+{syst}})× {10}-12 {erg} {{cm}}-2 {{{s}}}-1. M31 is detected to be extended with a 4σ significance. The spatial distribution of the emission is consistent with a uniform-brightness disk with a radius of 0.°4 and no offset from the center of the galaxy, but nonuniform intensity distributions cannot be excluded. The flux from M31 appears confined to the inner regions of the galaxy and does not fill the disk of the galaxy or extend far from it. The gamma-ray signal is not correlated with regions rich in gas or star formation activity, which suggests that the emission is not interstellar in origin, unless the energetic particles radiating in gamma rays do not originate in recent star formation. Alternative and nonexclusive interpretations are that the emission results from a population of millisecond pulsars

  10. VizieR Online Data Catalog: DIRECT lightcurves of 21 luminous YSGs in M33 (Kourniotis+, 2017)

    NASA Astrophysics Data System (ADS)

    Kourniotis, M.; Bonanos, A. Z.; Yuan, W.; Macri, L. M.; Garcia-Alvarez, D.; Lee, C.-H.

    2017-02-01

    File photom.dat contains the light curves of 21 luminous YSGs in M33 from Drout et al. (2012, Cat. J/ApJ/750/97). Observations were taken in the BVIc as part of the DIRECT project (Macri et al., 2001, Cat. J/AJ/121/861) and complemented with BVI observations taken between 2002 and 2006 from Pellerin & Macri (2011, Cat. J/ApJS/193/26). Only stars with a V-band J variability index higher than 0.75 are included. For each measurement we provide the LGGS designation, observing date, band filter, magnitude and uncertainty. (2 data files).

  11. Unmasking of CD22 Co-receptor on Germinal Center B-cells Occurs by Alternative Mechanisms in Mouse and Man*

    PubMed Central

    Macauley, Matthew S.; Kawasaki, Norihito; Peng, Wenjie; Wang, Shui-Hua; He, Yuan; Arlian, Britni M.; McBride, Ryan; Kannagi, Reiji; Khoo, Kay-Hooi; Paulson, James C.

    2015-01-01

    CD22 is an inhibitory B-cell co-receptor whose function is modulated by sialic acid (Sia)-bearing glycan ligands. Glycan remodeling in the germinal center (GC) alters CD22 ligands, with as yet no ascribed biological consequence. Here, we show in both mice and humans that loss of high affinity ligands on GC B-cells unmasks the binding site of CD22 relative to naive and memory B-cells, promoting recognition of trans ligands. The conserved modulation of CD22 ligands on GC B-cells is striking because high affinity glycan ligands of CD22 are species-specific. In both species, the high affinity ligand is based on the sequence Siaα2–6Galβ1–4GlcNAc, which terminates N-glycans. The human ligand has N-acetylneuraminic acid (Neu5Ac) as the sialic acid, and the high affinity ligand on naive B-cells contains 6-O-sulfate on the GlcNAc. On human GC B-cells, this sulfate modification is lost, giving rise to lower affinity CD22 ligands. Ligands of CD22 on naive murine B-cells do not contain the 6-O-sulfate modification. Instead, the high affinity ligand for mouse CD22 has N-glycolylneuraminic acid (Neu5Gc) as the sialic acid, which is replaced on GC B-cells with Neu5Ac. Human naive and memory B-cells express sulfated glycans as high affinity CD22 ligands, which are lost on GC B-cells. In mice, Neu5Gc-containing glycans serve as high affinity CD22 ligands that are replaced by Neu5Ac-containing glycans on GC B-cells. Our results demonstrate that loss of high affinity CD22 ligands on GC B-cells occurs in both mice and humans through alternative mechanisms, unmasking CD22 relative to naive and memory B-cells. PMID:26507663

  12. VizieR Online Data Catalog: Variable stars in M31 & M33. II. LBVs (Humphreys+, 2014)

    NASA Astrophysics Data System (ADS)

    Humphreys, R. M.; Weis, K.; Davidson, K.; Bomans, D. J.; Burggraf, B.

    2016-08-01

    In Paper I (Humphreys et al. 2013ApJ...773...46H), we discussed a small group of intermediate temperature supergiants, the warm hypergiants, and suggested that they were likely post-red supergiants. In this second paper, we review the spectral characteristics, spectral energy distributions (SEDs), circumstellar ejecta, and mass loss of the LBVs, candidate LBVs, emission line stars, and other luminous and variable stars in M31 and M33. The observations (described in paper I) were made in 2010 October with the Hectospec Multi-Object Spectrograph on the 6.5m MMT on Mount Hopkins. A few stars of special interest (5 in M31 and 8 in M33) were also observed with the MODS1 spectrograph on the Large Binocular Telescope (LBT) during commissioning in 2011 September, and in 2012 October and November, and 2013 January. All of the stars for which we have spectra are listed in Table 1 in order of right ascension. (2 data files).

  13. The close binary frequency of Wolf-Rayet stars as a function of metallicity in M31 and M33

    SciTech Connect

    Neugent, Kathryn F.; Massey, Philip E-mail: phil.massey@lowell.edu

    2014-07-01

    Massive star evolutionary models generally predict the correct ratio of WC-type and WN-type Wolf-Rayet stars at low metallicities, but underestimate the ratio at higher (solar and above) metallicities. One possible explanation for this failure is perhaps single-star models are not sufficient and Roche-lobe overflow in close binaries is necessary to produce the 'extra' WC stars at higher metallicities. However, this would require the frequency of close massive binaries to be metallicity dependent. Here we test this hypothesis by searching for close Wolf-Rayet binaries in the high metallicity environments of M31 and the center of M33 as well as in the lower metallicity environments of the middle and outer regions of M33. After identifying ∼100 Wolf-Rayet binaries based on radial velocity variations, we conclude that the close binary frequency of Wolf-Rayets is not metallicity dependent and thus other factors must be responsible for the overabundance of WC stars at high metallicities. However, our initial identifications and observations of these close binaries have already been put to good use as we are currently observing additional epochs for eventual orbit and mass determinations.

  14. VizieR Online Data Catalog: The M33 Synoptic Stellar Survey. II. Mira variables (Yuan+, 2017)

    NASA Astrophysics Data System (ADS)

    Yuan, W.; He, S.; Macri, L. M.; Long, J.; Huang, J. Z.

    2017-08-01

    We carried out a search for Mira variables in M33 using sparsely sampled I-band light curves. We based our search on the observations of M33 obtained by Macri et al. 2001 (Cat. J/AJ/121/861) and Pellerin et al. 2011 (Cat. J/ApJS/193/26). These surveys covered most of the disk of this galaxy with a combined baseline of nearly a decade (1996 September to 1999 November for Macri et al. 2001, Cat. J/AJ/121/861; 2002 August to 2006 August for Pellerin et al. 2011, Cat. J/ApJS/193/26) mainly using the Fred L. Whipple Observatory (FLWO) 1.2m and the WIYN observatory 3.5m telescopes with a variety of cameras (see the respective publications for details). While images were obtained in multiple bandpasses (BVI), our analysis is only based on the I-band time-series photometry because Mira candidates fall below the detection limit in the bluer bands. Our final sample consists of 1847 Mira candidates (see Table2). (1 data file).

  15. Growth, photosynthetic efficiency, and biochemical composition of Tetraselmis suecica F&M-M33 grown with LEDs of different colors.

    PubMed

    Abiusi, Fabian; Sampietro, Giacomo; Marturano, Giovanni; Biondi, Natascia; Rodolfi, Liliana; D'Ottavio, Massimo; Tredici, Mario R

    2014-05-01

    The effect of light quality on cell size and cell cycle, growth rate, productivity, photosynthetic efficiency and biomass composition of the marine prasinophyte Tetraselmis suecica F&M-M33 grown in 2-L flat panel photobioreactors illuminated with light emitting diodes (LEDs) of different colors was investigated. Biomass productivity and photosynthetic efficiency were comparable between white and red light, while under blue and green light productivity decreased to less than half and photosynthetic efficiency to about one third. Differences in cell size and number correlated with the cell cycle phase. Under red light cells were smaller and more motile. Chlorophyll content was strongly reduced with red and enhanced with blue light, while carotenoids and gross biomass composition were not affected by light quality. The eicosapentaenoic acid content increased under red light. Red light can substitute white light without affecting productivity of T. suecica F&M-M33, leading to smaller and more motile cells and increased eicosapentaenoic acid content. Red LEDs can thus be profitably used for the production of this microalga for aquaculture.

  16. PAndAS IN THE MIST: THE STELLAR AND GASEOUS MASS WITHIN THE HALOS OF M31 AND M33

    SciTech Connect

    Lewis, Geraint F.; Braun, Robert; McConnachie, Alan W.; Irwin, Michael J.; Chapman, Scott C.; Ibata, Rodrigo A.; Martin, Nicolas F.; Ferguson, Annette M. N.; Fardal, Mark; Dubinski, John; Widrow, Larry; Mackey, A. Dougal; Babul, Arif; Tanvir, Nial R.; Rich, Michael

    2013-01-20

    Large-scale surveys of the prominent members of the Local Group have provided compelling evidence for the hierarchical formation of massive galaxies, revealing a wealth of substructure that is thought to be the debris from ancient and ongoing accretion events. In this paper, we compare two extant surveys of the M31-M33 subgroup of galaxies: the Pan-Andromeda Archaeological Survey of the stellar structure, and a combination of observations of the H I gaseous content, detected at 21 cm. Our key finding is a marked lack of spatial correlation between these two components on all scales, with only a few potential overlaps between stars and gas. The paucity of spatial correlation significantly restricts the analysis of kinematic correlations, although there does appear to be H I kinematically associated with the Giant Stellar Stream where it passes the disk of M31. These results demonstrate that different processes must significantly influence the dynamical evolution of the stellar and H I components of substructures, such as ram pressure driving gas away from a purely gravitational path. Detailed modeling of the offset between the stellar and gaseous substructures will provide a determination of the properties of the gaseous halos of M31 and M33.

  17. PAndAS in the Mist: The Stellar and Gaseous Mass within the Halos of M31 and M33

    NASA Astrophysics Data System (ADS)

    Lewis, Geraint F.; Braun, Robert; McConnachie, Alan W.; Irwin, Michael J.; Ibata, Rodrigo A.; Chapman, Scott C.; Ferguson, Annette M. N.; Martin, Nicolas F.; Fardal, Mark; Dubinski, John; Widrow, Larry; Mackey, A. Dougal; Babul, Arif; Tanvir, Nial R.; Rich, Michael

    2013-01-01

    Large-scale surveys of the prominent members of the Local Group have provided compelling evidence for the hierarchical formation of massive galaxies, revealing a wealth of substructure that is thought to be the debris from ancient and ongoing accretion events. In this paper, we compare two extant surveys of the M31-M33 subgroup of galaxies: the Pan-Andromeda Archaeological Survey of the stellar structure, and a combination of observations of the H I gaseous content, detected at 21 cm. Our key finding is a marked lack of spatial correlation between these two components on all scales, with only a few potential overlaps between stars and gas. The paucity of spatial correlation significantly restricts the analysis of kinematic correlations, although there does appear to be H I kinematically associated with the Giant Stellar Stream where it passes the disk of M31. These results demonstrate that different processes must significantly influence the dynamical evolution of the stellar and H I components of substructures, such as ram pressure driving gas away from a purely gravitational path. Detailed modeling of the offset between the stellar and gaseous substructures will provide a determination of the properties of the gaseous halos of M31 and M33.

  18. Cognitive Impairment Induced by Delta9-tetrahydrocannabinol Occurs through Heteromers between Cannabinoid CB1 and Serotonin 5-HT2A Receptors

    PubMed Central

    Lanfumey, Laurence; Cordomí, Arnau; Pastor, Antoni; de La Torre, Rafael; Gasperini, Paola; Navarro, Gemma; Howell, Lesley A.; Pardo, Leonardo; Lluís, Carmen; Canela, Enric I.; McCormick, Peter J.; Maldonado, Rafael; Robledo, Patricia

    2015-01-01

    Activation of cannabinoid CB1 receptors (CB1R) by delta9-tetrahydrocannabinol (THC) produces a variety of negative effects with major consequences in cannabis users that constitute important drawbacks for the use of cannabinoids as therapeutic agents. For this reason, there is a tremendous medical interest in harnessing the beneficial effects of THC. Behavioral studies carried out in mice lacking 5-HT2A receptors (5-HT2AR) revealed a remarkable 5-HT2AR-dependent dissociation in the beneficial antinociceptive effects of THC and its detrimental amnesic properties. We found that specific effects of THC such as memory deficits, anxiolytic-like effects, and social interaction are under the control of 5-HT2AR, but its acute hypolocomotor, hypothermic, anxiogenic, and antinociceptive effects are not. In biochemical studies, we show that CB1R and 5-HT2AR form heteromers that are expressed and functionally active in specific brain regions involved in memory impairment. Remarkably, our functional data shows that costimulation of both receptors by agonists reduces cell signaling, antagonist binding to one receptor blocks signaling of the interacting receptor, and heteromer formation leads to a switch in G-protein coupling for 5-HT2AR from Gq to Gi proteins. Synthetic peptides with the sequence of transmembrane helices 5 and 6 of CB1R, fused to a cell-penetrating peptide, were able to disrupt receptor heteromerization in vivo, leading to a selective abrogation of memory impairments caused by exposure to THC. These data reveal a novel molecular mechanism for the functional interaction between CB1R and 5-HT2AR mediating cognitive impairment. CB1R-5-HT2AR heteromers are thus good targets to dissociate the cognitive deficits induced by THC from its beneficial antinociceptive properties. PMID:26158621

  19. Cognitive Impairment Induced by Delta9-tetrahydrocannabinol Occurs through Heteromers between Cannabinoid CB1 and Serotonin 5-HT2A Receptors.

    PubMed

    Viñals, Xavier; Moreno, Estefanía; Lanfumey, Laurence; Cordomí, Arnau; Pastor, Antoni; de La Torre, Rafael; Gasperini, Paola; Navarro, Gemma; Howell, Lesley A; Pardo, Leonardo; Lluís, Carmen; Canela, Enric I; McCormick, Peter J; Maldonado, Rafael; Robledo, Patricia

    2015-07-01

    Activation of cannabinoid CB1 receptors (CB1R) by delta9-tetrahydrocannabinol (THC) produces a variety of negative effects with major consequences in cannabis users that constitute important drawbacks for the use of cannabinoids as therapeutic agents. For this reason, there is a tremendous medical interest in harnessing the beneficial effects of THC. Behavioral studies carried out in mice lacking 5-HT2A receptors (5-HT2AR) revealed a remarkable 5-HT2AR-dependent dissociation in the beneficial antinociceptive effects of THC and its detrimental amnesic properties. We found that specific effects of THC such as memory deficits, anxiolytic-like effects, and social interaction are under the control of 5-HT2AR, but its acute hypolocomotor, hypothermic, anxiogenic, and antinociceptive effects are not. In biochemical studies, we show that CB1R and 5-HT2AR form heteromers that are expressed and functionally active in specific brain regions involved in memory impairment. Remarkably, our functional data shows that costimulation of both receptors by agonists reduces cell signaling, antagonist binding to one receptor blocks signaling of the interacting receptor, and heteromer formation leads to a switch in G-protein coupling for 5-HT2AR from Gq to Gi proteins. Synthetic peptides with the sequence of transmembrane helices 5 and 6 of CB1R, fused to a cell-penetrating peptide, were able to disrupt receptor heteromerization in vivo, leading to a selective abrogation of memory impairments caused by exposure to THC. These data reveal a novel molecular mechanism for the functional interaction between CB1R and 5-HT2AR mediating cognitive impairment. CB1R-5-HT2AR heteromers are thus good targets to dissociate the cognitive deficits induced by THC from its beneficial antinociceptive properties.

  20. The naturally occurring mutation Y197C does not affect the expression or signaling of the human histamine H3 receptor.

    PubMed

    Flores-Clemente, Cecilia; Escamilla-Sánchez, Juan; Arias, Juan-Manuel; Arias-Montaño, José-Antonio

    2017-02-22

    There is evidence for genetic polymorphism within the human histamine H3 receptor (hH3R), and a Tyr to Cys exchange at position 197 (Y197C), located in the amino terminus of the fifth transmembrane domain, has been reported. In this work we compared the expression and the pharmacological and signaling properties of wild-type (hH3RWT) and mutant (hH3RY197C) receptors transiently expressed in CHO-K1 cells. The hH3RY197C cDNA was created by overlap extension PCR amplification. Receptor expression and affinity were assessed by N-α-[methyl-(3)H]-histamine binding to cell membranes and intact cells. Receptor function was evaluated by stimulation of [(35)S]-GTPγS binding to cell membranes and by inhibition of forskolin-induced cAMP accumulation in intact cells. The hH3RWT and hH3RY197C were expressed at similar levels (761±68 and 663±66fmol/mg protein for membranes, and 13,434±1533 and 15,894±1884 receptors per cell, respectively). There were no significant differences in the affinities for H3R agonists or antagonists/inverse agonists between the hH3RWT and hH3RY197C, and the H3R agonist RAMH was similarly efficacious and potent to stimulate [(35)S]-GTPγS binding and to inhibit forskolin-induced cAMP accumulation. These results indicate that the Y197C mutation does not affect the expression, ligand affinity or signaling of the human H3 receptor.

  1. GPCR responses in vascular smooth muscle can occur predominantly through dual transactivation of kinase receptors and not classical Gαq protein signalling pathways.

    PubMed

    Little, Peter J

    2013-05-30

    GPCR signalling is well known to proceed through several linear pathways involving activation of G proteins and their downstream signalling pathways such as activation of phospholipase C. In addition, GPCRs signal via transactivation of Protein Tyrosine Kinase receptors such as that for Epidermal Growth Factor (EGF) and Platelet-Derived Growth Factor (PDGF) where GPCR agonists mediate increase levels of phosphorylated Erk (pErk) the immediate downstream product of the activation of EGF receptor. It has recently been shown that this paradigm can be extended to include the GPCR transactivation of a Protein Serine/Threonine Kinase receptor, specifically the Transforming Growth Factor β Type I receptor (also known as Alk V) (TβRI) in which case GPCR activation leads to the formation of carboxy terminal polyphosphorylated Smad2 (phosphoSmad2) being the immediate downstream product of the activation of TβRI. Growth factor and hormone regulation of proteoglycan synthesis in vascular smooth muscle cells represent one component of an in vitro model of atherosclerosis because modified proteoglycans show enhanced binding to lipoproteins as the initiating step in atherosclerosis. In the example of proteoglycan synthesis stimulated by GPCR agonists such as thrombin and endothelin-1, the transactivation pathways for the EGF receptor and TβRI are both active and together account for essentially all of the response to the GPCRs. In contrast, signalling downstream of GPCRs such as increased inositol 1,4,5 trisphosphate (IP3) and intracellular calcium do not have any effect on GPCR stimulated proteoglycan synthesis. These data lead to the conclusion that dual transactivation pathways for protein tyrosine and serine/threonine kinase receptors may play a far greater role in GPCR signalling than currently recognised.

  2. Fermi Large Area Telescope observations of Local Group galaxies: detection of M 31 and search for M 33

    DOE PAGES

    Abdo, A. A.

    2010-11-01

    Context. Cosmic rays (CRs) can be studied through the galaxy-wide gamma-ray emission that they generate when propagating in the interstellar medium. The comparison of the diffuse signals from different systems may inform us about the key parameters in CR acceleration and transport. Aims. We aim to determine and compare the properties of the cosmic-ray-induced gamma-ray emission of several Local Group galaxies. Methods. We use 2 years of nearly continuous sky-survey observations obtained with the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope to search for gamma-ray emission from M 31 and M 33. We compare the results with thosemore » for the Large Magellanic Cloud, the Small Magellanic Cloud, the Milky Way, and the starburst galaxies M 82 and NGC 253. Results. We detect a gamma-ray signal at 5σ significance in the energy range 200 MeV–20 GeV that is consistent with originating from M 31. The integral photon flux above 100 MeV amounts to (9.1 ± 1.9stat ± 1.0sys) × 10-9 ph cm-2 s-1. We find no evidence for emission from M 33 and derive an upper limit on the photon flux >100 MeV of 5.1 × 10-9 ph cm-2 s-1 (2σ). Comparing these results to the properties of other Local Group galaxies, we find indications of a correlation between star formation rate and gamma-ray luminosity that also holds for the starburst galaxies. Conclusions. The gamma-ray luminosity of M 31 is about half that of the Milky Way, which implies that the ratio between the average CR densities in M 31 and the Milky Way amounts to ξ = 0.35 ± 0.25. The observed correlation between gamma-ray luminosity and star formation rate suggests that the flux of M 33 is not far below the current upper limit from the LAT observations.« less

  3. Fermi Large Area Telescope observations of Local Group galaxies: detection of M 31 and search for M 33

    NASA Astrophysics Data System (ADS)

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Cannon, A.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Dermer, C. D.; de Angelis, A.; de Palma, F.; Digel, S. W.; Silva, E. Do Couto E.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Favuzzi, C.; Fegan, S. J.; Fortin, P.; Frailis, M.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Harding, A. K.; Hayashi, K.; Hayashida, M.; Hays, E.; Healey, S. E.; Jean, P.; Jóhannesson, G.; Johnson, A. S.; Johnson, R. P.; Johnson, T. J.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kerr, M.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lee, S.-H.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Martin, P.; Mazziotta, M. N.; Mehault, J.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Parent, D.; Pepe, M.; Persic, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Ritz, S.; Romani, R. W.; Sadrozinski, H. F.-W.; Saz Parkinson, P. M.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Smith, P. D.; Spandre, G.; Spinelli, P.; Strickman, M. S.; Strigari, L.; Strong, A. W.; Suson, D. J.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vianello, G.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Ziegler, M.

    2010-11-01

    Context. Cosmic rays (CRs) can be studied through the galaxy-wide gamma-ray emission that they generate when propagating in the interstellar medium. The comparison of the diffuse signals from different systems may inform us about the key parameters in CR acceleration and transport. Aims: We aim to determine and compare the properties of the cosmic-ray-induced gamma-ray emission of several Local Group galaxies. Methods: We use 2 years of nearly continuous sky-survey observations obtained with the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope to search for gamma-ray emission from M 31 and M 33. We compare the results with those for the Large Magellanic Cloud, the Small Magellanic Cloud, the Milky Way, and the starburst galaxies M 82 and NGC 253. Results: We detect a gamma-ray signal at 5σ significance in the energy range 200 MeV-20 GeV that is consistent with originating from M 31. The integral photon flux above 100 MeV amounts to (9.1 ± 1.9stat ± 1.0sys) × 10-9 ph cm-2 s-1. We find no evidence for emission from M 33 and derive an upper limit on the photon flux >100 MeV of 5.1 × 10-9 ph cm-2 s-1 (2σ). Comparing these results to the properties of other Local Group galaxies, we find indications of a correlation between star formation rate and gamma-ray luminosity that also holds for the starburst galaxies. Conclusions: The gamma-ray luminosity of M 31 is about half that of the Milky Way, which implies that the ratio between the average CR densities in M 31 and the Milky Way amounts to ξ = 0.35 ± 0.25. The observed correlation between gamma-ray luminosity and star formation rate suggests that the flux of M 33 is not far below the current upper limit from the LAT observations. Appendix A is only available in electronic form at http://www.aanda.org

  4. Antibody uptake into neurons occurs primarily via clathrin-dependent Fcγ receptor endocytosis and is a prerequisite for acute tau protein clearance.

    PubMed

    Congdon, Erin E; Gu, Jiaping; Sait, Hameetha B R; Sigurdsson, Einar M

    2013-12-06

    Tau immunotherapy is effective in transgenic mice, but the mechanisms of Tau clearance are not well known. To this end, Tau antibody uptake was analyzed in brain slice cultures and primary neurons. Internalization was rapid (<1 h), saturable, and substantial compared with control mouse IgG. Furthermore, temperature reduction to 4 °C, an excess of unlabeled mouse IgG, or an excess of Tau antibodies reduced uptake in slices by 63, 41, and 62%, respectively (p = 0.002, 0.04, and 0.005). Uptake strongly correlated with total and insoluble Tau levels (r(2) = 0.77 and 0.87 and p = 0.002 and 0.0002), suggesting that Tau aggregates influence antibody internalization and/or retention within neurons. Inhibiting phagocytosis did not reduce uptake in slices or neuronal cultures, indicating limited microglial involvement. In contrast, clathrin-specific inhibitors reduced uptake in neurons (≤ 78%, p < 0.0001) and slices (≤ 35%, p = 0.03), demonstrating receptor-mediated endocytosis as the primary uptake pathway. Fluid phase endocytosis accounted for the remainder of antibody uptake in primary neurons, based on co-staining with internalized dextran. The receptor-mediated uptake is to a large extent via low affinity FcγII/III receptors and can be blocked in slices (43%, p = 0.04) and neurons (53%, p = 0.008) with an antibody against these receptors. Importantly, antibody internalization appears to be necessary for Tau reduction in primary neurons. Overall, these findings clarify that Tau antibody uptake is primarily receptor-mediated, that these antibodies are mainly found in neurons with Tau aggregates, and that their intracellular interaction leads to clearance of Tau pathology, all of which have major implications for therapeutic development of this approach.

  5. Observations of M31 and M33 with the Fermi Large Area Telescope: A Galactic Center Excess in Andromeda?

    DOE PAGES

    Ackermann, M.; Ajello, M.; Albert, A.; ...

    2017-02-23

    We report the Fermi Large Area Telescope (LAT) has opened the way for comparative studies of cosmic rays (CRs) and high-energy objects in the Milky Way (MW) and in other, external, star-forming galaxies. Using 2 yr of observations with the Fermi LAT, Local Group galaxy M31 was detected as a marginally extended gamma-ray source, while only an upper limit has been derived for the other nearby galaxy M33. We revisited the gamma-ray emission in the direction of M31 and M33 using more than 7 yr of LAT Pass 8 data in the energy rangemore » $$0.1\\mbox{--}100\\,\\mathrm{GeV}$$, presenting detailed morphological and spectral analyses. M33 remains undetected, and we computed an upper limit of $$2.0\\times {10}^{-12}\\,\\mathrm{erg}\\,{\\mathrm{cm}}^{-2}\\,{{\\rm{s}}}^{-1}\\,$$ on the $$0.1\\mbox{--}100\\,\\mathrm{GeV}$$ energy flux (95% confidence level). This revised upper limit remains consistent with the observed correlation between gamma-ray luminosity and star formation rate tracers and implies an average CR density in M33 that is at most half of that of the MW. M31 is detected with a significance of nearly $$10\\sigma $$. Its spectrum is consistent with a power law with photon index $${\\rm{\\Gamma }}=2.4\\pm {0.1}_{\\mathrm{stat}+\\mathrm{syst}}$$ and a $$0.1\\mbox{--}100\\,\\mathrm{GeV}$$ energy flux of $$(5.6\\pm {0.6}_{\\mathrm{stat}+\\mathrm{syst}})\\times {10}^{-12}\\,\\mathrm{erg}\\,{\\mathrm{cm}}^{-2}\\,{{\\rm{s}}}^{-1}$$. M31 is detected to be extended with a $$4\\sigma $$ significance. The spatial distribution of the emission is consistent with a uniform-brightness disk with a radius of 0fdg4 and no offset from the center of the galaxy, but nonuniform intensity distributions cannot be excluded. The flux from M31 appears confined to the inner regions of the galaxy and does not fill the disk of the galaxy or extend far from it. The gamma-ray signal is not correlated with regions rich in gas or star formation activity, which suggests that the emission is not

  6. Spectral study of the late nitrogen-sequence Wolf-Rayet star FSZ35 in M33

    NASA Astrophysics Data System (ADS)

    Maryeva, O.; Abolmasov, P.

    2012-04-01

    We study and analyse the low-resolution spectra of the unusual late nitrogen-sequence Wolf-Rayet (WN) star FSZ35 in M33. We classify the object as a hydrogen-rich WN8 star. Using the radiative transfer code CMFGEN, we determine the physical parameters of this object and we compare these to the parameters of other WN8 stars, including the luminous blue variable V532 (also known as Romano's star) during the minimum of its brightness. Unlike V532, the object is fairly stable, both spectrally and photometrically, which can be attributed to its more advanced evolutionary stage or lower luminosity. FSZ35 is shown to possess a compact nebula that produces a faint but detectable [O III] emission.

  7. Formation of the black-hole binary M33 X-7 through mass exchange in a tight massive system.

    PubMed

    Valsecchi, Francesca; Glebbeek, Evert; Farr, Will M; Fragos, Tassos; Willems, Bart; Orosz, Jerome A; Liu, Jifeng; Kalogera, Vassiliki

    2010-11-04

    The X-ray source M33 X-7 in the nearby galaxy Messier 33 is among the most massive X-ray binary stellar systems known, hosting a rapidly spinning, 15.65M(⊙) black hole orbiting an underluminous, 70M(⊙) main-sequence companion in a slightly eccentric 3.45-day orbit (M(⊙), solar mass). Although post-main-sequence mass transfer explains the masses and tight orbit, it leaves unexplained the observed X-ray luminosity, the star's underluminosity, the black hole's spin and the orbital eccentricity. A common envelope phase, or rotational mixing, could explain the orbit, but the former would lead to a merger and the latter to an overluminous companion. A merger would also ensue if mass transfer to the black hole were invoked for its spin-up. Here we report simulations of evolutionary tracks which reveal that if M33 X-7 started as a primary body of 85M(⊙)-99M(⊙) and a secondary body of 28M(⊙)-32M(⊙), in a 2.8-3.1-d orbit, its observed properties can be consistently explained. In this model, the main-sequence primary transfers part of its envelope to the secondary and loses the rest in a wind; it ends its life as a ∼16M(⊙) helium star with an iron-nickel core that collapses to a black hole (with or without an accompanying supernova). The release of binding energy, and possibly collapse asymmetries, 'kick' the nascent black hole into an eccentric orbit. Wind accretion explains the X-ray luminosity, and the black-hole spin can be natal.

  8. Histamine H3 receptor agonist- and antagonist-evoked vacuous chewing movements in 6-OHDA-lesioned rats occurs in an absence of change in microdialysate dopamine levels.

    PubMed

    Nowak, Przemysław; Dabrowska, Joanna; Bortel, Aleksandra; Biedka, Izabela; Szczerbak, Grazyna; Słomian, Grzegorz; Kostrzewa, Richard M; Brus, Ryszard

    2006-12-15

    In rats lesioned neonatally with 6-hydroxydopamine (6-OHDA), repeated treatment with SKF 38393 (1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol), a dopamine D(1)/D(5) receptor agonist, produces robust stereotyped and locomotor activities. The gradual induction of dopamine D(1) receptor supersensitivity is known as a priming phenomenon, and this process is thought to underlie not only the appearance of vacuous chewing movements in humans with tardive dyskinesia, but also the onset of motor dyskinesias in L-dihydroxyphenylalanine (L-DOPA)-treated Parkinson's disease patients. The object of the present study was to determine the possible influence of the histaminergic system on dopamine D(1) agonist-induced activities. We found that neither imetit (5.0 mg/kg i.p.), a histamine H(3) receptor agonist, nor thioperamide (5.0 mg/kg i.p.), a histamine H(3) receptor antagonist/inverse agonist, altered the numbers of vacuous chewing movements in non-primed-lesioned rats. However, in dopamine D(1) agonist-primed rats, thioperamide alone produced a vacuous chewing movements response (i.e., P < 0.05 vs SKF 38393, 1.0 mg/kg i.p.), but did not modify the SKF 38393 effect. Notably, both imetit and thioperamide-induced catalepsy in both non-primed and primed 6-OHDA-lesioned rats, comparable in magnitude to the effect of the dopamine D(1)/D(5) receptor antagonist SCH 23390 (7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine; 0.5 mg/kg i.p.). Furthermore, in primed animals both imetit and thioperamide intensified SCH 23390-evoked catalepsy. In vivo microdialysis established that neither imetit nor thioperamide altered extraneuronal levels of dopamine and its metabolites in the striatum of 6-OHDA-lesioned rats. On the basis of the present study, we believe that histaminergic systems may augment dyskinesias induced by dopamine receptor agonists, independent of direct actions on dopaminergic neurons.

  9. Potentiation and inhibition of Ca2+ release-activated Ca2+ channels by 2-aminoethyldiphenyl borate (2-APB) occurs independently of IP3 receptors

    PubMed Central

    Prakriya, Murali; Lewis, Richard S

    2001-01-01

    The effects of the IP3-receptor antagonist 2-aminoethyldiphenyl borate (2-APB) on the Ca2+ release-activated Ca2+ current (ICRAC) in Jurkat human T cells, DT40 chicken B cells and rat basophilic leukaemia (RBL) cells were examined.2-APB elicited both stimulatory and inhibitory effects on Ca2+ influx through CRAC channels. At concentrations of 1–5 μm, 2-APB enhanced Ca2+ entry in intact cells and increased ICRAC amplitude by up to fivefold. At levels ≥ 10 μm, 2-APB caused a transient enhancement of ICRAC followed by inhibition.2-APB altered the kinetics of fast Ca2+-dependent inactivation of ICRAC. At concentrations of 1–5 μm, 2-APB increased the rate of fast inactivation. In contrast, 2-APB at higher concentrations (≥ 10 μm) reduced or completely blocked inactivation.2-APB inhibited Ca2+ efflux from mitochondria.2-APB inhibited ICRAC more potently when applied extracellularly than intracellularly. Furthermore, increased protonation of 2-APB at low pH did not affect potentiation or inhibition. Thus, 2-APB may have an extracellular site of action.Neither ICRAC activation by passive store depletion nor the effects of 2-APB were altered by intracellular dialysis with 500 μg ml−1 heparin.ICRAC is present in wild-type as well as mutant DT40 B cells lacking all three IP3 receptor isoforms. 2-APB also potentiates and inhibits ICRAC in both cell types, indicating that 2-APB exerts its effects independently of IP3 receptors.Our results show that CRAC channel activation does not require physical interaction with IP3 receptors as proposed in the conformational coupling model. Potentiation of ICRAC by 2-APB may be a useful diagnostic feature for positive identification of putative CRAC channel genes, and provides a novel tool for exploring the physiological functions of store-operated channels. PMID:11579153

  10. Effects of the xenoestrogen bisphenol A in diencephalic regions of the teleost fish Coris julis occur preferentially via distinct somatostatin receptor subtypes.

    PubMed

    Alo', Raffaella; Facciolo, Rosa Maria; Madeo, Maria; Giusi, Giuseppina; Carelli, Antonio; Canonaco, Marcello

    2005-04-15

    The xenoestrogen bisphenol A, a contaminant used in the manufacturing of polymers for many consumer products, has been shown to mimic estrogenic actions. This xenoestrogen regulates secretion and expression of pituitary lactotrophs plus morphological and structural features of estrogen target tissues in rodents. Recently, ecological hazards produced by bisphenol A have drawn interests towards the effects of this environmental chemical on neurobiological functions of aquatic vertebrates of which little is known. In this study, the effects of bisphenol A on the distribution of the biologically more active somatostatin receptor subtypes in diencephalic regions of the teleost fish Coris julis were assessed using nonpeptide agonists (L-779, 976 and L-817, 818) that are highly selective for subtype(2) and subtype(5), respectively. Bisphenol A proved to be responsible for highly significant increased binding levels of subtype(2) in hypothalamic areas, while markedly decreased levels of subtype(5) were found in these diencephalic areas, as well as in the medial preglomerular nucleus. The extensive distribution of somatostatin receptor subtype(2) and subtype(5) in the teleost diencephalic areas suggests that, like in mammals, this receptor system may not only be involved in enhanced hypophysiotropic neurohormonal functions but might also promote neuroplasticity events.

  11. The Metabotropic Glutamate Receptor, mGlu5, Is Required for Extinction Learning That Occurs in the Absence of a Context Change

    PubMed Central

    André, Marion Agnes Emma; Güntürkün, Onur; Manahan-Vaughan, Denise

    2015-01-01

    The metabotropic glutamate (mGlu) receptors and, in particular, mGlu5 are crucially involved in multiple forms of synaptic plasticity that are believed to underlie explicit memory. MGlu5 is also required for information transfer through neuronal oscillations and for spatial memory. Furthermore, mGlu5 is involved in extinction of implicit forms of learning. This places this receptor in a unique position with regard to information encoding. Here, we explored the role of this receptor in context-dependent extinction learning under constant, or changed, contextual conditions. Animals were trained over 3 days to take a left turn under 25% reward probability in a T-maze with a distinct floor pattern (Context A). On Day 4, they experienced either a floor pattern change (Context B) or the same floor pattern (Context A) in the absence of reward. After acquisition of the task, the animals were returned to the maze once more on Day 5 (Context A, no reward). Treatment with the mGlu5 antagonist, 2-methyl-6-(phenylethynyl) pyridine, before maze exposure on Day 4 completely inhibited extinction learning in the AAA paradigm but had no effect in the ABA paradigm. A subsequent return to the original context (A, on Day 5) revealed successful extinction in the AAA paradigm, but impairment of extinction in the ABA paradigm. These data support that although extinction learning in a new context is unaffected by mGlu5 antagonism, extinction of the consolidated context is impaired. This suggests that mGlu5 is intrinsically involved in enabling learning that once-relevant information is no longer valid. © 2014 The Authors. Hippocampus Published by Wiley Periodicals, Inc. PMID:25160592

  12. The metabotropic glutamate receptor, mGlu5, is required for extinction learning that occurs in the absence of a context change.

    PubMed

    André, Marion Agnes Emma; Güntürkün, Onur; Manahan-Vaughan, Denise

    2015-02-01

    The metabotropic glutamate (mGlu) receptors and, in particular, mGlu5 are crucially involved in multiple forms of synaptic plasticity that are believed to underlie explicit memory. MGlu5 is also required for information transfer through neuronal oscillations and for spatial memory. Furthermore, mGlu5 is involved in extinction of implicit forms of learning. This places this receptor in a unique position with regard to information encoding. Here, we explored the role of this receptor in context-dependent extinction learning under constant, or changed, contextual conditions. Animals were trained over 3 days to take a left turn under 25% reward probability in a T-maze with a distinct floor pattern (Context A). On Day 4, they experienced either a floor pattern change (Context B) or the same floor pattern (Context A) in the absence of reward. After acquisition of the task, the animals were returned to the maze once more on Day 5 (Context A, no reward). Treatment with the mGlu5 antagonist, 2-methyl-6-(phenylethynyl) pyridine, before maze exposure on Day 4 completely inhibited extinction learning in the AAA paradigm but had no effect in the ABA paradigm. A subsequent return to the original context (A, on Day 5) revealed successful extinction in the AAA paradigm, but impairment of extinction in the ABA paradigm. These data support that although extinction learning in a new context is unaffected by mGlu5 antagonism, extinction of the consolidated context is impaired. This suggests that mGlu5 is intrinsically involved in enabling learning that once-relevant information is no longer valid.

  13. Orbits of massive satellite galaxies - I. A close look at the Large Magellanic Cloud and a new orbital history for M33

    NASA Astrophysics Data System (ADS)

    Patel, Ekta; Besla, Gurtina; Sohn, Sangmo Tony

    2017-02-01

    The Milky Way (MW) and M31 both harbour massive satellite galaxies, the Large Magellanic Cloud (LMC) and M33, which may comprise up to 10 per cent of their host's total mass. Massive satellites can change the orbital barycentre of the host-satellite system by tens of kiloparsec and are cosmologically expected to harbour dwarf satellite galaxies of their own. Assessing the impact of these effects crucially depends on the orbital histories of the LMC and M33. Here, we revisit the dynamics of the MW-LMC system and present the first detailed analysis of the M31-M33 system utilizing high-precision proper motions and statistics from the dark-matter-only Illustris cosmological simulation. With the latest Hubble Space Telescope proper motion measurements of M31, we reliably constrain M33's interaction history with its host. In particular, like the LMC, M33 is either on its first passage (tinf < 2 Gyr ago) or if M31 is massive (≥2 × 1012 M⊙), it is on a long-period orbit of about 6 Gyr. Cosmological analogues of the LMC and M33 identified in Illustris support this picture and provide further insight about their host masses. We conclude that, cosmologically, massive satellites such as the LMC and M33 are likely completing their first orbits about their hosts. We also find that the orbital energies of such analogues prefer an MW halo mass ˜1.5 × 1012 M⊙ and an M31 halo mass ≥1.5 × 1012 M⊙. Despite conventional wisdom, we conclude it is highly improbable that M33 made a close (<100 kpc) approach to M31 recently (tperi < 3 Gyr ago). Such orbits are rare (<1 per cent) within the 4σ error space allowed by observations. This conclusion cannot be explained by perturbative effects through four-body encounters amongst the MW, M31, M33, and the LMC. This surprising result implies that we must search for a new explanation for M33's strongly warped gas and stellar discs.

  14. The heating of mid-infrared dust in the nearby galaxy M33: A testbed for tracing galaxy evolution

    SciTech Connect

    Calapa, Marie D.; Calzetti, Daniela; Draine, Bruce T. E-mail: calzetti@astro.umass.edu; and others

    2014-04-01

    Infrared emission is an invaluable tool for quantifying star formation in galaxies. Because the 8 μm polycyclic aromatic hydrocarbon (PAH) emission has been found to correlate with other well-known star formation tracers, it has widely been used as a star formation rate (SFR) tracer. There are, however, studies that challenge the accuracy and reliability of the 8 μm emission as a SFR tracer. Our study, part of the Herschel (Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA) M33 Extended Survey (HERM33ES) open time key program, aims at addressing this issue by analyzing the infrared emission from the nearby spiral galaxy M33 at the high spatial scale of ∼75 pc. Combining data from the Herschel Space Observatory and the Spitzer Space Telescope, we find that the 8 μm emission is better correlated with the 250 μm emission, which traces cold interstellar gas, than with the 24 μm emission. Furthermore, the L(8)/L(250) ratio is more tightly correlated with the 3.6 μm emission, a tracer of evolved stellar populations and stellar mass, than with a combination of Hα and 24 μm emission, a tracer of SFR. The L(8)/L(24) ratio is highly depressed in 24 μm luminous regions, which correlate with known H II regions. We also compare our results with the dust emission models by Draine and Li. We confirm that the depression of 8 μm PAH emission near star-forming regions is higher than what is predicted by models; this is possibly an effect of increased stellar radiation from young stars destroying the dust grains responsible for the 8 μm emission as already suggested by other authors. We find that the majority of the 8 μm emission is fully consistent with heating by the diffuse interstellar medium, similar to what recently determined for the dust emission in M31 by Draine et al. We also find that the fraction of 8 μm emission associated with the diffuse

  15. Direct Toll-like receptor-mediated stimulation of hematopoietic stem and progenitor cells occurs in vivo and promotes differentiation toward macrophages.

    PubMed

    Megías, Javier; Yáñez, Alberto; Moriano, Silvia; O'Connor, José-Enrique; Gozalbo, Daniel; Gil, María-Luisa

    2012-07-01

    As Toll-like receptors (TLRs) are expressed by hematopoietic stem and progenitor cells (HSPCs), they may play a role in hematopoiesis in response to pathogens during infection. We show here that TLR2, TLR4, and TLR9 agonists (tripalmitoyl-S-glyceryl-L-Cys-Ser-(Lys)4 [Pam3CSK4], lipopolysaccharide [LPS], and CpG oligodeoxynucleotide [ODN]) induce the in vitro differentiation of purified murine lineage negative cells (Lin(-) ) as well as HSPCs (identified as Lin(-) c-Kit(+) Sca-1(+) IL-7Rα(-) [LKS] cells) toward macrophages (Mph), through a myeloid differentiation factor 88 (MyD88)-dependent pathway. In order to investigate the possible direct interaction of soluble microorganism-associated molecular patterns and TLRs on HSPCs in vivo, we designed a new experimental approach: purified Lin(-) and LKS cells from bone marrow of B6Ly5.1 mice (CD45.1 alloantigen) were transplanted into TLR2(-/-) , TLR4(-/-) , or MyD88(-/-) mice (CD45.2 alloantigen), which were then injected with soluble TLR ligands (Pam3CSK4, LPS, or ODN, respectively). As recipient mouse cells do not recognize the TLR ligands injected, interference by soluble mediators secreted by recipient cells is negligible. Transplanted cells were detected in the spleen and bone marrow of recipient mice, and in response to soluble TLR ligands, cells differentiated preferentially to Mph. These results show, for the first time, that HSPCs may be directly stimulated by TLR agonists in vivo, and that the engagement of these receptors induces differentiation toward Mph. Therefore, HSPCs may sense pathogen or pathogen-derived products directly during infection, inducing a rapid generation of cells of the innate immune system.

  16. β cell membrane remodelling and procoagulant events occur in inflammation-driven insulin impairment: a GLP-1 receptor dependent and independent control.

    PubMed

    Gleizes, Céline; Kreutter, Guillaume; Abbas, Malak; Kassem, Mohamad; Constantinescu, Andrei Alexandru; Boisramé-Helms, Julie; Yver, Blandine; Toti, Florence; Kessler, Laurence

    2016-02-01

    Inflammation and hyperglycaemia are associated with a prothrombotic state. Cell-derived microparticles (MPs) are the conveyors of active procoagulant tissue factor (TF) and circulate at high concentration in diabetic patients. Liraglutide, a glucagon-like peptide (GLP)-1 analogue, is known to promote insulin secretion and β-cell preservation. In this in vitro study, we examined the link between insulin impairment, procoagulant activity and plasma membrane remodelling, under inflammatory conditions. Rin-m5f β-cell function, TF activity mediated by MPs and their modulation by 1 μM liraglutide were examined in a cell cross-talk model. Methyl-β-cyclodextrine (MCD), a cholesterol depletor, was used to evaluate the involvement of raft on TF activity, MP shedding and insulin secretion as well as Soluble N-éthylmaleimide-sensitive-factor Attachment protein Receptor (SNARE)-dependent exocytosis. Cytokines induced a two-fold increase in TF activity at MP surface that was counteracted by liraglutide. Microparticles prompted TF activity on the target cells and a two-fold decrease in insulin secretion via protein kinase A (PKA) and p38 signalling, that was also abolished by liraglutide. Large lipid raft clusters were formed in response to cytokines and liraglutide or MCD-treated cells showed similar patterns. Cells pre-treated by saturating concentration of the GLP-1r antagonist exendin (9-39), showed a partial abolishment of the liraglutide-driven insulin secretion and liraglutide-decreased TF activity. Measurement of caspase 3 cleavage and MP shedding confirmed the contribution of GLP-1r-dependent and -independent pathways. Our results confirm an integrative β-cell response to GLP-1 that targets receptor-mediated signalling and membrane remodelling pointing at the coupling of insulin secretion and inflammation-driven procoagulant events. © 2015 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  18. THE ARAUCARIA PROJECT. A DISTANCE DETERMINATION TO THE LOCAL GROUP SPIRAL M33 FROM NEAR-INFRARED PHOTOMETRY OF CEPHEID VARIABLES

    SciTech Connect

    Gieren, Wolfgang; Pietrzynski, Grzegorz; Graczyk, Dariusz E-mail: pietrzyn@hubble.cfm.udec.cl; and others

    2013-08-10

    Motivated by an amazing range of reported distances to the nearby Local Group spiral galaxy M33, we have obtained deep near-infrared photometry for 26 long-period Cepheids in this galaxy with the ESO Very Large Telescope. From the data, we constructed period-luminosity relations in the J and K bands which together with previous optical VI photometry for the Cepheids by Macri et al. were used to determine the true distance modulus of M33, and the mean reddening affecting the Cepheid sample with the multiwavelength fit method developed in the Araucaria Project. We find a true distance modulus of 24.62 for M33, with a total uncertainty of {+-}0.07 mag which is dominated by the uncertainty on the photometric zero points in our photometry. The reddening is determined as E(B - V) = 0.19 {+-} 0.02, in agreement with the value used by the Hubble Space Telescope Key Project of Freedman et al. but in some discrepancy with other recent determinations based on blue supergiant spectroscopy and an O-type eclipsing binary which yielded lower reddening values. Our derived M33 distance modulus is extremely insensitive to the adopted reddening law. We show that the possible effects of metallicity and crowding on our present distance determination are both at the 1%-2% level and therefore minor contributors to the total uncertainty of our distance result for M33.

  19. A naturally occurring mutation in the human androgen receptor of a subject with complete androgen insensitivity confers binding and transactivation by estradiol.

    PubMed

    Bonagura, Thomas W; Deng, Min; Brown, Terry R

    2007-01-15

    The clinical phenotype of complete androgen insensitivity (CAIS) was associated with a mutation in the human androgen receptor (hAR) gene encoding the amino acid substitution, M745I, in the hAR protein. Transcriptional activation of hAR(M745I) by the synthetic androgen, methyltrienolone (R1881), was reduced compared to wild-type (wt) hAR. The transcriptional co-activator, androgen receptor associated protein 70 (ARA70), failed to enhance transactivation of hAR(M745I) at lower concentrations of R1881 (0.01-0.1 nM), whereas the p160 co-activators, SRC-1 and TIF2, stimulated activity. Transcriptional activity of hAR(M745I) was stimulated by 1 or 10 nM R1881 and activity was further enhanced by co-expression of ARA70 similar to that of the hAR(wt). Transcriptional activity of hAR(wt) was minimally stimulated by estradiol (E2) without or with co-expression of ARA70, whereas 10 or 100 nM E2 increased transactivation by hAR(M745I) of the androgen-responsive MMTV-luciferase reporter gene by 10-fold and activity was further enhanced by ARA70. Increasing concentrations of E2 competed more effectively for binding of R1881 to hAR(M745I) than to hAR(wt), indicative of the preferential binding of E2 to the mutant hAR. Partial tryptic digestion of hAR wt and M745I revealed that activation of the mutant protein was reduced in the presence of R1881. By contrast, tryptic digestion showed that the mutant hAR was activated by the binding of E2. In conclusion, the clinical phenotype of CAIS resulted from a hAR gene mutation encoding hAR(M745I) with reduced binding and transactivation by androgens, but the novel properties of enhanced affinity for and increased transactivation by estradiol.

  20. Reversible kallmann syndrome, delayed puberty, and isolated anosmia occurring in a single family with a mutation in the fibroblast growth factor receptor 1 gene.

    PubMed

    Pitteloud, Nelly; Acierno, James S; Meysing, Astrid U; Dwyer, Andrew A; Hayes, Frances J; Crowley, William F

    2005-03-01

    Kallmann syndrome (KS) is a clinically and genetically heterogeneous disorder. Recently, loss-of-function mutations in the fibroblast growth factor receptor 1 (FGFR1) gene have been shown to cause autosomal dominant KS. To date, the detailed reproductive phenotype of KS associated with mutations in the FGFR1 has yet to be described. We report a kindred comprising a male proband with KS and spontaneous reversibility, whose mother had delayed puberty and whose maternal grandfather isolated anosmia. The proband presented at age 18 yr with KS and was subsequently treated with testosterone (T) therapy. Upon discontinuation of T therapy, he recovered from his hypogonadotropic hypogonadism, as evidenced by a normal LH secretion pattern, sustained normal serum T levels, and active spermatogenesis. The three members of this single family harbor the same FGFR1 mutation (Arg(622)X) in the tyrosine kinase domain. This report demonstrates 1) the first genetic cause of the rare variant of reversible KS, 2) the reversal of hypogonadotropic hypogonadism in a proband carrying an FGFR1 mutation suggests a role of FGFR1 beyond embryonic GnRH neuron migration, and 3) a loss of function mutation in the FGFR1 gene causing delayed puberty.

  1. The Contribution of Field OB Stars to the Ionization of the Diffuse Ionized Gas in M33

    NASA Astrophysics Data System (ADS)

    Hoopes, Charles G.; Walterbos, René A. M.

    2000-10-01

    We present a study of the ionizing stars associated with the diffuse ionized gas (DIG) and H II regions in the nearby spiral galaxy M33. We compare our Schmidt Hα image to the far-ultraviolet (FUV, 1520 Å) image from the Ultraviolet Imaging Telescope (UIT). The Hα/FUV ratio is higher in H II regions than in the DIG, suggesting an older population of ionizing stars in the DIG. Assuming ionization equilibrium, we convert the Hα flux to the number of Lyman continuum photons NLyc. When compared to models of evolving stellar populations, the NLyc/FUV ratio in H II regions is consistent with a young burst, while the DIG ratio resembles an older burst population, or a steady state population built up by constant star formation, which is probably a more accurate description of the stellar population in the field. The UIT data is complemented with archival FUV and optical images of a small portion of the disk of M33 obtained with WFPC2 on board the Hubble Space Telescope (HST). These images overlap low- and mid-luminosity H II regions as well as DIG, so we can investigate the stellar population in these environments. Using the HST FUV and optical photometry, we assign spectral types to the stars observed in DIG and H II regions. The photometry indicates that ionizing stars are present in the DIG. We compare the predicted ionizing flux with the amount required to produce the observed Hα emission, and we find that field OB stars in the HST images can account for 40%+/-12% of the ionization of the DIG, while the stars in H II regions can provide 107%+/-26% of the Hα luminosity of the H II regions. Due to the limited coverage of the HST data, we cannot determine if stars outside the HST fields ionize some of the DIG located in the HST fields, nor can we determine if photons from stars inside the HST fields leak out of the area covered by the HST fields. We do not find any correlation between leakage of ionizing photons and Hα luminosity for the H II regions in our HST

  2. Evolved Massive Stars in the Local Group. I. Identification of Red Supergiants in NGC 6822, M31, and M33

    NASA Astrophysics Data System (ADS)

    Massey, Philip

    1998-07-01

    Knowledge of the red supergiant (RSG) population of nearby galaxies allows us to probe massive star evolution as a function of metallicity; however, contamination by foreground Galactic dwarfs dominates surveys for red stars in Local Group galaxies beyond the Magellanic Clouds. Model atmospheres predict that low-gravity supergiants will have B-V values that are redder by several tenths of a magnitude than foreground dwarfs at a given V-R color, a result that is largely independent of reddening. We conduct a BVR survey of several fields in the Local Group galaxies NGC 6822, M33, and M31 as well as neighboring control fields and identify RSG candidates from CCD photometry. The survey is complete to V = 20.5, corresponding to MV = -4.5 or an Mbol of -6.3 for the reddest stars. Follow-up spectroscopy at the Ca II triplet of 130 stars is used to demonstrate that our photometric criterion for identifying RSGs is highly successful (96% for stars brighter than V = 19.5; 82% for V = 19.5-20.5). Classification spectra are also obtained for a number of stars in order to calibrate color with spectral type empirically. We find that there is a marked progression in the average (B-V)0 and (V-R)0 colors of RSGs in these three galaxies, with the higher metallicity systems having a later average spectral type, which is consistent with previous findings by Elias, Frogel, & Humphreys for the Milky Way and Magellanic Clouds. More significantly, we find that there is a clear progression with metallicity in the relative number of the highest luminosity RSGs, a trend that is apparent both in absolute visual magnitude and in bolometric luminosity. Thus any use of RSGs as distance indicators requires correction for the metallicity of the parent galaxy. Our findings are in accord with the predictions of the ``Conti scenario'' in which higher metallicities result in higher mass-loss rates, resulting in a star of a given luminosity spending an increasing fraction of its He-burning lifetime as

  3. A survey of the Local Group of galaxies for symbiotic binary stars - I. First detection of symbiotic stars in M33

    NASA Astrophysics Data System (ADS)

    Mikołajewska, Joanna; Shara, Michael M.; Caldwell, Nelson; Iłkiewicz, Krystian; Zurek, David

    2017-02-01

    We present and discuss initial selection criteria and first results in M33 from a systematic search for extragalactic symbiotic stars. We show that the presence of diffuse ionized gas (DIG) emission can significantly contaminate the spectra of symbiotic star candidates. This important effect forces upon us a more stringent working definition of an extragalactic symbiotic star. We report the first detections and spectroscopic characterization of 12 symbiotic binaries in M33. We found that four of our systems contain carbon-rich giants. In another two of them, the giant seems to be a Zr-enhanced MS star, while the remaining six objects host M-type giants. The high number ratio of C to M giants in these binaries is consistent with the low metallicity of M33. The spatial and radial velocity distributions of these new symbiotic binaries are consistent with a wide range of progenitor star ages.

  4. Bryostatin-1, a naturally occurring antineoplastic agent, acts as a Toll-like receptor 4 (TLR-4) ligand and induces unique cytokines and chemokines in dendritic cells.

    PubMed

    Ariza, Maria Eugenia; Ramakrishnan, Rupal; Singh, Narendra P; Chauhan, Ashok; Nagarkatti, Prakash S; Nagarkatti, Mitzi

    2011-01-07

    Bryostatin-1 (Bryo-1), a natural macrocyclic lactone, is clinically used as an anti-cancer agent. In this study, we demonstrate for the first time that Bryo-1 acts as a Toll-like receptor 4 (TLR4) ligand. Interestingly, activation of bone marrow-derived dendritic cells (in vitro with Bryo-1) led to a TLR4-dependent biphasic activation of nuclear factor-κB (NF-κB) and the unique induction of cytokines (IL-5, IL-6, and IL-10) and chemokines, including RANTES (regulated on activation normal T cell expressed and secreted) and macrophage inflammatory protein 1α (MIP1-α). In addition, EMSA demonstrated that Bryo-1-mediated induction of RANTES was regulated by NF-κB and the interferon regulatory factors (IRF)-1, IRF-3, and IRF-7 to the RANTES independently of myeloid differentiation primary response gene-88 (MyD88). Bryo-1 was able to induce the transcriptional activation of IRF-3 through the TLR4/MD2-dependent pathway. In vivo administration of Bryo-1 triggered a TLR-4-dependent T helper cell 2 (Th2) cytokine response and expanded a subset of myeloid dendritic cells that expressed a CD11c(high)CD8α(-) CD11b(+)CD4(+) phenotype. This study demonstrates that Bryo-1 can act as a TLR4 ligand and activate innate immunity. Moreover, the ability of Bryo-1 to trigger RANTES and MIP1-α suggests that Bryo-1 could potentially be used to prevent HIV-1 infection. Finally, induction of a Th2 response by Bryo-1 may help treat inflammatory diseases mediated by Th1 cells. Together, our studies have a major impact on the clinical use of Bryo-1 as an anti-cancer and immunopotentiating agent.

  5. Lutein transport by Caco-2 TC-7 cells occurs partly by a facilitated process involving the scavenger receptor class B type I (SR-BI).

    PubMed

    Reboul, Emmanuelle; Abou, Lydia; Mikail, Céline; Ghiringhelli, Odette; André, Marc; Portugal, Henri; Jourdheuil-Rahmani, Dominique; Amiot, Marie-Josèphe; Lairon, Denis; Borel, Patrick

    2005-04-15

    The carotenoid lutein is thought to play a role in the human eye and to protect against age-related macular degeneration. Lutein transport in the human intestine has not been characterized. We examined lutein transport processes using Caco-2 TC-7 monolayers as a model for human intestinal epithelium. Purified lutein was mixed with phospholipids, lysophospholipids, cholesterol, mono-olein, oleic acid and taurocholate to obtain lutein-rich mixed micelles that mimicked those found under physiological conditions. The micelles were added to the apical side of Caco-2 TC-7 cell monolayers for 30 min or 3 h at 37 degrees C. Absorbed lutein, i.e. the sum of lutein recovered in the scraped cells and in the basolateral chamber, was quantified by HPLC. Transport rate was measured (i) as a function of time (from 15 to 60 min), (ii) as a function of micellar lutein concentration (from 1.5 to 15 microM), (iii) at 4 degrees C, (iv) in the basolateral to apical direction, (v) after trypsin pretreatment, (vi) in the presence of beta-carotene and/or lycopene, (vii) in the presence of increasing concentrations of antibody against SR-BI (scavenger receptor class B type 1) and (viii) in the presence of increasing concentrations of a chemical inhibitor of the selective transfer of lipids mediated by SR-BI, i.e. BLT1 (blocks lipid transport 1). The rate of transport of lutein as a function of time and as a function of concentration was saturable. It was significantly lower at 4 degrees C than at 37 degrees C (approx. 50%), in the basal to apical direction than in the opposite direction (approx. 85%), and after trypsin pretreatment (up to 45%). Co-incubation with beta-carotene, but not lycopene, decreased the lutein absorption rate (approx. 20%) significantly. Anti-SR-BI antibody and BLT1 significantly impaired the absorption rate (approx. 30% and 57% respectively). Overall, these results indicate that lutein absorption is, at least partly, protein-mediated and that some lutein is taken up

  6. Lutein transport by Caco-2 TC-7 cells occurs partly by a facilitated process involving the scavenger receptor class B type I (SR-BI)

    PubMed Central

    2004-01-01

    The carotenoid lutein is thought to play a role in the human eye and to protect against age-related macular degeneration. Lutein transport in the human intestine has not been characterized. We examined lutein transport processes using Caco-2 TC-7 monolayers as a model for human intestinal epithelium. Purified lutein was mixed with phospholipids, lysophospholipids, cholesterol, mono-olein, oleic acid and taurocholate to obtain lutein-rich mixed micelles that mimicked those found under physiological conditions. The micelles were added to the apical side of Caco-2 TC-7 cell monolayers for 30 min or 3 h at 37 °C. Absorbed lutein, i.e. the sum of lutein recovered in the scraped cells and in the basolateral chamber, was quantified by HPLC. Transport rate was measured (i) as a function of time (from 15 to 60 min), (ii) as a function of micellar lutein concentration (from 1.5 to 15 μM), (iii) at 4 °C, (iv) in the basolateral to apical direction, (v) after trypsin pretreatment, (vi) in the presence of β-carotene and/or lycopene, (vii) in the presence of increasing concentrations of antibody against SR-BI (scavenger receptor class B type 1) and (viii) in the presence of increasing concentrations of a chemical inhibitor of the selective transfer of lipids mediated by SR-BI, i.e. BLT1 (blocks lipid transport 1). The rate of transport of lutein as a function of time and as a function of concentration was saturable. It was significantly lower at 4 °C than at 37 °C (approx. 50%), in the basal to apical direction than in the opposite direction (approx. 85%), and after trypsin pretreatment (up to 45%). Co-incubation with β-carotene, but not lycopene, decreased the lutein absorption rate (approx. 20%) significantly. Anti-SR-BI antibody and BLT1 significantly impaired the absorption rate (approx. 30% and 57% respectively). Overall, these results indicate that lutein absorption is, at least partly, protein-mediated and that some lutein is taken up through SR

  7. Luminous and Variable Stars in M31 and M33. I. The Warm Hypergiants and Post-red Supergiant Evolution

    NASA Astrophysics Data System (ADS)

    Humphreys, Roberta M.; Davidson, Kris; Grammer, Skyler; Kneeland, Nathan; Martin, John C.; Weis, Kerstin; Burggraf, Birgitta

    2013-08-01

    The progenitors of Type IIP supernovae (SNe) have an apparent upper limit to their initial masses of about 20 M ⊙, suggesting that the most massive red supergiants evolve to warmer temperatures before their terminal explosion. But very few post-red supergiants are known. We have identified a small group of luminous stars in M31 and M33 that are candidates for post-red supergiant evolution. These stars have A-F-type supergiant absorption line spectra and strong hydrogen emission. Their spectra are also distinguished by the Ca II triplet and [Ca II] doublet in emission formed in a low-density circumstellar environment. They all have significant near- and mid-infrared excess radiation due to free-free emission and thermal emission from dust. We estimate the amount of mass they have shed and discuss their wind parameters and mass loss rates, which range from a few × 10-6 to 10-4 M ⊙ yr-1. On an H-R diagram, these stars will overlap the region of the luminous blue variables (LBVs) at maximum light; however, the warm hypergiants are not LBVs. Their non-spherical winds are not optically thick, and they have not exhibited any significant variability. We suggest, however, that the warm hypergiants may be the progenitors of the "less luminous" LBVs such as R71 and even SN1987A. Based on observations with the Multiple Mirror Telescope, a joint facility of the Smithsonian Institution and the University of Arizona and on observations obtained with the Large Binocular Telescope (LBT), an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are: The University of Arizona on behalf of the Arizona University system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota

  8. Var C: Long-term photometric and spectral variability of a luminous blue variable in M 33

    NASA Astrophysics Data System (ADS)

    Burggraf, B.; Weis, K.; Bomans, D. J.; Henze, M.; Meusinger, H.; Sholukhova, O.; Zharova, A.; Pellerin, A.; Becker, A.

    2015-09-01

    Aims: So far the highly unstable phase of luminous blue variables (LBVs) has not been understood well. It is still uncertain why and which massive stars enter this phase. Investigating the variabilities by looking for a possible regular or even (semi-)periodic behaviour could give a hint at the underlying mechanism for these variations and might answer the question of where these variabilities originate. Finding out more about the LBV phase also means understanding massive stars better in general, which have (e.g. by enriching the ISM with heavy elements, providing ionising radiation and kinetic energy) a strong and significant influence on the ISM, hence also on their host galaxy. Methods: Photometric and spectroscopic data were taken for the LBV Var C in M 33 to investigate its recent status. In addition, scanned historic plates, archival data, and data from the literature were gathered to trace Var C's behaviour in the past. Its long-term variability and periodicity was investigated. Results: Our investigation of the variability indicates possible (semi-)periodic behaviour with a period of 42.3 years for Var C. That Var C's light curve covers a time span of more than 100 years means that more than two full periods of the cycle are visible. The critical historic maximum around 1905 is less strong but discernible even with the currently rare historic data. The semi-periodic and secular structure of the light curve is similar to the one of LMC R71. Both light curves hint at a new aspect in the evolution of LBVs. Based on observations collected at the Thüringer Landessternwarte (TLS) Tautenburg.Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC).Tables 2-4, and 6 are available in electronic form at http://www.aanda.org

  9. OPTICAL SPECTROPHOTOMETRIC MONITORING OF THE EXTREME LUMINOUS BLUE VARIABLE STAR GR 290 (ROMANO's STAR) IN M 33

    SciTech Connect

    Polcaro, V. F.; Viotti, R. F.; Rossi, C.; Galleti, S.; Gualandi, R.; Norci, L.

    2011-01-15

    We study the long-term, S Dor-type variability and the present hot phase of the luminous blue variable (LBV) star GR 290 (Romano's Star) in M 33 in order to investigate possible links between the LBV and the late, nitrogen sequence Wolf-Rayet Stars (WNL) stages of very massive stars. We use intermediate-resolution spectra, obtained with the William Herschel Telescope (WHT) in 2008 December, when GR 290 was at minimum (V = {approx}18.6), as well as new low-resolution spectra and BVRI photometry obtained with the Loiano and Cima Ekar telescopes during 2007-2010. We identify more than 80 emission lines in the 3100-10000 A range covered by the WHT spectra, belonging to different species: the hydrogen Balmer and Paschen series, neutral and ionized helium, C III, N II-III, S IV, Si III-IV, and many forbidden lines of [N II], [O III], [S III], [A III], [Ne III], and [Fe III]. Many lines, especially the He I triplets, show a P Cygni profile with an a-e radial velocity difference of -300 to -500 km s{sup -1}. The shape of the 4630-4713 A emission blend and of other emission lines resembles that of WN9 stars; the blend deconvolution shows that the He II 4686 A has a strong broad component with FWHM {approx_equal} 1700 km s{sup -1}. During 2003-2010 the star underwent large spectral variations, best seen in the 4630-4686 A emission feature. Using the late-WN spectral types of Crowther and Smith, GR 290 apparently varied between the WN11 and WN8-9 spectral types; the hotter the star was the fainter its visual magnitude was. This spectrum-visual luminosity anticorrelation of GR 290 is reminiscent of the behavior of the best-studied LBVs, such as S Dor and AG Car. During the 2008 minimum, we found a significant decrease in bolometric luminosity, which could be attributed to absorption by newly formed circumstellar matter. We suggest that the broad 4686 A line and the optical continuum formed in a central Wolf-Rayet region, while the narrow emission line spectrum originated in an

  10. Eclipsing Binaries in the Local Group: III - Unprecedented Accuracy in Distance Determination to M33 and Calibration of the Cosmic Distance Scale

    NASA Astrophysics Data System (ADS)

    Guinan, Edward

    2009-07-01

    The Great Spiral Galaxy in Triangulum {M33} is a crucial calibrator for the Cosmic Distance Scale, and thus for determining the age and evolution of the Universe. M33 is viewed face-on, has a simple geometry, large and diverse stellar populations, and morphologies similar to our Galaxy and other more distant galaxies used for distance determinations. Yet currently the M33 distance {d 830 +/- 120 kpc} still has measurement dispersions of 10-15%. Moreover, the distance to M33 derived from Cepheids, RR Lyrae stars, H2O masers, RGB stars, and EBs is currently discrepant by 15% {Bonanos et al. 2006}. In our work on the LMC and M31 distances we have demonstrated that double-line eclipsing binaries serve as excellent "standard candles." Distances derived from eclipsing binaries are basically geometric and essentially free from many assumptions and uncertainties that plague other less direct methods, such as metallicity differences and calibration zeropoints. The absolute radii of the component stars of eclipsing binaries can be determined to better than a few percent from the time-tested analyses of their light and radial velocity curves. With accurate determinations of radii, temperatures, and ISM absorption it is possible to determine reliable distances. In Cycle 15 we extended our program of using eclipsing binaries as standard candles to M33 using ACS/SBS and WFPC/2 spectrophotometry of a well suited 19th mag O7+O7 eclipsing binary system. Although insightful, ACS/SBC data alone do not provide sufficient accuracy for the unambigous determination of individual temperatures, [Fe/H], and ISM extinction, which are central to distance determination. We propose a 4 orbit follow-up spectrophotometry with the newly installed HST/COS G140L and the repaired HST/STIS G230L and G430L to obtain the single missing key element of this program. These quantities, when combined with the results from existing light and radial velocity curves for the target {cf. Bonanos et al. 2006

  11. The Araucaria Project. A Distance Determination to the Local Group Spiral M33 from Near-infrared Photometry of Cepheid Variables

    NASA Astrophysics Data System (ADS)

    Gieren, Wolfgang; Górski, Marek; Pietrzyński, Grzegorz; Konorski, Piotr; Suchomska, Ksenia; Graczyk, Dariusz; Pilecki, Bogumil; Bresolin, Fabio; Kudritzki, Rolf-Peter; Storm, Jesper; Karczmarek, Paulina; Gallenne, Alexandre; Calderón, Paula; Geisler, Doug

    2013-08-01

    Motivated by an amazing range of reported distances to the nearby Local Group spiral galaxy M33, we have obtained deep near-infrared photometry for 26 long-period Cepheids in this galaxy with the ESO Very Large Telescope. From the data, we constructed period-luminosity relations in the J and K bands which together with previous optical VI photometry for the Cepheids by Macri et al. were used to determine the true distance modulus of M33, and the mean reddening affecting the Cepheid sample with the multiwavelength fit method developed in the Araucaria Project. We find a true distance modulus of 24.62 for M33, with a total uncertainty of ±0.07 mag which is dominated by the uncertainty on the photometric zero points in our photometry. The reddening is determined as E(B - V) = 0.19 ± 0.02, in agreement with the value used by the Hubble Space Telescope Key Project of Freedman et al. but in some discrepancy with other recent determinations based on blue supergiant spectroscopy and an O-type eclipsing binary which yielded lower reddening values. Our derived M33 distance modulus is extremely insensitive to the adopted reddening law. We show that the possible effects of metallicity and crowding on our present distance determination are both at the 1%-2% level and therefore minor contributors to the total uncertainty of our distance result for M33. Based on observations obtained with the ESO VLT for program 382.D-0469(A).

  12. Optical Spectrophotometric Monitoring of the Extreme Luminous Blue Variable Star GR 290 (Romano's Star) in M 33

    NASA Astrophysics Data System (ADS)

    Polcaro, V. F.; Rossi, C.; Viotti, R. F.; Galleti, S.; Gualandi, R.; Norci, L.

    2011-01-01

    We study the long-term, S Dor-type variability and the present hot phase of the luminous blue variable (LBV) star GR 290 (Romano's Star) in M 33 in order to investigate possible links between the LBV and the late, nitrogen sequence Wolf-Rayet Stars (WNL) stages of very massive stars. We use intermediate-resolution spectra, obtained with the William Herschel Telescope (WHT) in 2008 December, when GR 290 was at minimum (V = ~18.6), as well as new low-resolution spectra and BVRI photometry obtained with the Loiano and Cima Ekar telescopes during 2007-2010. We identify more than 80 emission lines in the 3100-10000 Å range covered by the WHT spectra, belonging to different species: the hydrogen Balmer and Paschen series, neutral and ionized helium, C III, N II-III, S IV, Si III-IV, and many forbidden lines of [N II], [O III], [S III], [A III], [Ne III], and [Fe III]. Many lines, especially the He I triplets, show a P Cygni profile with an a-e radial velocity difference of -300 to -500 km s-1. The shape of the 4630-4713 Å emission blend and of other emission lines resembles that of WN9 stars; the blend deconvolution shows that the He II 4686 Å has a strong broad component with FWHM ~= 1700 km s-1. During 2003-2010 the star underwent large spectral variations, best seen in the 4630-4686 Å emission feature. Using the late-WN spectral types of Crowther & Smith, GR 290 apparently varied between the WN11 and WN8-9 spectral types; the hotter the star was the fainter its visual magnitude was. This spectrum-visual luminosity anticorrelation of GR 290 is reminiscent of the behavior of the best-studied LBVs, such as S Dor and AG Car. During the 2008 minimum, we found a significant decrease in bolometric luminosity, which could be attributed to absorption by newly formed circumstellar matter. We suggest that the broad 4686 Å line and the optical continuum formed in a central Wolf-Rayet region, while the narrow emission line spectrum originated in an extended, slowly expanding

  13. Swift/UVOT Measurements of the UV Dust Extinction Curve and the Recent Star Formation History of the SMC and M33

    NASA Astrophysics Data System (ADS)

    Hagen, Lea M. Z.; Siegel, Michael; Hoversten, Erik A.; Gronwall, Caryl; Immler, Stefan; Vargas, Angelica

    2017-01-01

    The Swift Ultraviolet/Optical Telescope (UVOT) is uniquely suited to study star formation and dust extinction in nearby galaxies. I will discuss results from the Small Magellanic Cloud (SMC) and M33, for which we have unprecedented observations in three near-UV bands from 1700-3000Å at 2.5" resolution. We combine our UV imaging with archival optical and infrared data to model the spectral energy distributions of individual regions of each galaxy, simultaneously fitting for the dust extinction curve properties, total dust, stellar mass, and age. We have created the first-ever maps of the UV dust extinction curve, which show previously-unconfirmed spatial variation: both the slope and 2175Å bump vary considerably over the face of both the SMC and M33. I will discuss the implications of these results on studies of star formation and galaxy evolution at both low and high redshift.

  14. Multi-scale radio-infrared correlations in M 31 and M 33: The role of magnetic fields and star formation

    NASA Astrophysics Data System (ADS)

    Tabatabaei, F. S.; Berkhuijsen, E. M.; Frick, P.; Beck, R.; Schinnerer, E.

    2013-09-01

    Interstellar magnetic fields and the propagation of cosmic ray electrons have an important impact on the radio-infrared (IR) correlation in galaxies. This becomes evident when studying different spatial scales within galaxies. We investigate the correlation between the IR and free-free/synchrotron radio continuum emission at 20 cm from the two local group galaxies M 31 and M 33 on spatial scales between 0.4 and 10 kpc. The multi-scale radio-IR correlations have been carried out using a wavelet analysis. The free-free and IR emission are correlated on all scales, but on some scales the synchrotron emission is only marginally correlated with the IR emission. The synchrotron-IR correlation is stronger in M 33 than in M 31 on small scales (<1 kpc), but it is weaker than in M 31 on larger scales. Taking the smallest scale on which the synchrotron-IR correlation exists as the propagation length of cosmic ray electrons, we show that the difference on small scales can be explained by the smaller propagation length in M 33 than in M 31. On large scales, the difference is due to the thick disk/halo in M 33, which is absent in M 31. A comparison of our data with data on NGC 6946, the LMC and M 51 suggests that the propagation length is determined by the ratio of ordered-to-turbulent magnetic field strength, which is consistent with diffusion of CR electrons in the ISM. As the diffusion length of CR electrons influences the radio-IR correlation, this dependence is a direct observational evidence of the importance of magnetic fields for the radio-IR correlation within galaxies. The star-formation rate per surface area only indirectly influences the diffusion length as it increases the strength of the turbulent magnetic field.

  15. Luminous and variable stars in M31 and M33. II. Luminous blue variables, candidate LBVs, Fe II emission line stars, and other supergiants

    SciTech Connect

    Humphreys, Roberta M.; Davidson, Kris; Weis, Kerstin; Bomans, D. J.; Burggraf, Birgitta E-mail: kweis@astro.rub.de

    2014-07-20

    An increasing number of non-terminal eruptions are being found in the numerous surveys for optical transients. Very little is known about these giant eruptions, their progenitors and their evolutionary state. A greatly improved census of the likely progenitor class, including the most luminous evolved stars, the luminous blue variables (LBVs), and the warm and cool hypergiants is now needed for a complete picture of the final pre-supernova stages of very massive stars. We have begun a survey of the evolved and unstable luminous star populations in several nearby resolved galaxies. In this second paper on M31 and M33, we review the spectral characteristics, spectral energy distributions, circumstellar ejecta, and evidence for mass loss for 82 luminous and variable stars. We show that many of these stars have warm circumstellar dust including several of the Fe II emission line stars, but conclude that the confirmed LBVs in M31 and M33 do not. The confirmed LBVs have relatively low wind speeds even in their hot, quiescent or visual minimum state compared to the B-type supergiants and Of/WN stars which they spectroscopically resemble. The nature of the Fe II emission line stars and their relation to the LBV state remains uncertain, but some have properties in common with the warm hypergiants and the sgB[e] stars. Several individual stars are discussed in detail. We identify three possible candidate LBVs and three additional post-red supergiant candidates. We suggest that M33-013406.63 (UIT301,B416) is not an LBV/S Dor variable, but is a very luminous late O-type supergiant and one of the most luminous stars or pair of stars in M33.

  16. Naturally occurring chemical carcinogens

    USDA-ARS?s Scientific Manuscript database

    Natural products are chemicals found in nature which have unique pharmacological effects. Humans are exposed to many of these bioactive naturally occurring chemicals via the air breathed, the water drunk and the food eaten. Exposure also occurs in clinical settings. Naturally occurring chemicals ...

  17. The identification of extreme asymptotic giant branch stars and red supergiants in M33 with 24 μm variability

    SciTech Connect

    Montiel, Edward J.; Clayton, Geoffrey C.; Johnson, Christopher B.; Srinivasan, Sundar; Engelbracht, Charles W.

    2015-02-01

    We present the first detection of 24 μm variability in 24 sources in the Local Group galaxy M33. These results are based on 4 epochs of Multiband Imaging Photometer for Spitzer observations, which are irregularly spaced over ∼750 days. We find that these sources are constrained exclusively to the Holmberg radius of the galaxy, which increases their chances of being members of M33. We have constructed spectral energy distributions (SEDs) ranging from the optical to the submillimeter to investigate the nature of these objects. We find that 23 of our objects are most likely heavily self-obscured, evolved stars, while the remaining source is the Giant H ii region, NGC 604. We believe that the observed variability is the intrinsic variability of the central star reprocessed through their circumstellar dust shells. Radiative transfer modeling was carried out to determine their likely chemical composition, luminosity, and dust production rate (DPR). As a sample, our modeling has determined an average luminosity of (3.8±0.9)×10{sup 4} L{sub ⊙} and a total DPR of (2.3±0.1)×10{sup −5} M{sub ⊙} yr{sup −1}. Most of the sources, given the high DPRs and short wavelength obscuration, are likely extreme asymptotic giant branch (XAGB) stars. Five of the sources are found to have luminosities above the classical AGB limit (M{sub bol} <−7.1 mag, L > 54,000 L{sub ⊙}), which classifies them as probable red supergiants (RSGs). Almost all of the sources are classified as oxygen-rich. As also seen in the LMC, a significant fraction of the dust in M33 is produced by a handful of XAGB and RSG stars.

  18. Fermi Large Area Telescope observations of Local Group galaxies: detection of M 31 and search for M 33

    SciTech Connect

    Abdo, A. A.

    2010-11-01

    Context. Cosmic rays (CRs) can be studied through the galaxy-wide gamma-ray emission that they generate when propagating in the interstellar medium. The comparison of the diffuse signals from different systems may inform us about the key parameters in CR acceleration and transport. Aims. We aim to determine and compare the properties of the cosmic-ray-induced gamma-ray emission of several Local Group galaxies. Methods. We use 2 years of nearly continuous sky-survey observations obtained with the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope to search for gamma-ray emission from M 31 and M 33. We compare the results with those for the Large Magellanic Cloud, the Small Magellanic Cloud, the Milky Way, and the starburst galaxies M 82 and NGC 253. Results. We detect a gamma-ray signal at 5σ significance in the energy range 200 MeV–20 GeV that is consistent with originating from M 31. The integral photon flux above 100 MeV amounts to (9.1 ± 1.9stat ± 1.0sys) × 10-9 ph cm-2 s-1. We find no evidence for emission from M 33 and derive an upper limit on the photon flux >100 MeV of 5.1 × 10-9 ph cm-2 s-1 (2σ). Comparing these results to the properties of other Local Group galaxies, we find indications of a correlation between star formation rate and gamma-ray luminosity that also holds for the starburst galaxies. Conclusions. The gamma-ray luminosity of M 31 is about half that of the Milky Way, which implies that the ratio between the average CR densities in M 31 and the Milky Way amounts to ξ = 0.35 ± 0.25. The observed correlation between gamma-ray luminosity and star formation rate suggests that the flux of M 33 is not far below the current upper limit from the LAT observations.

  19. The Strange Case of Hubble's V19 in M33: Monitoring the Remarkable Changes and Possible Real-Time Evolution of a Classical Cepheid

    NASA Astrophysics Data System (ADS)

    Engle, Scott G.; Guinan, E.; Macri, L.; Pellerin, A.

    2011-01-01

    In the influential work "A Spiral Nebula as a Stellar System: Messier 33” (Hubble 1926) Edwin Hubble determined the distance to M33 by using 35 Cepheids he discovered. One of those Cepheids was designated V19. Observations revealed V19 to have a 54.7-day period and B-band (converted from photographic magnitudes) light amplitude of 1.1-mag. Its mean B-magnitude was 19.59+/-0.23. Its properties were consistent with the Period-Luminosity Law for M33 derived by Hubble at that time. Follow up observations in 1996-1997 as part of the DIRECT Program (Macri et al. 2001), however, revealed large and surprising changes in the properties of V19. Its mean B-magnitude had risen to 19.05+/-0.05 and its amplitude had fallen to < 0.1-mag. The DIRECT study thoroughly checked for possible misclassifications of the variable or contamination by nearby objects, and found none. For all intents and purposes, V19 was no longer a Classical Cepheid, or at least varying below the detectable levels of the photometry. The only other well-documented instance of Cepheid pulsations declining over time is in the case of Polaris - whose V-band amplitude fell from just over 0.1-mag to below 0.03-mag over the course of a century (Engle et al 2004). Also, a study of Polaris’ visual magnitudes over the past two millennia has shown a possible increase in brightness of 1-mag over the past 1000 years. The changes present in V19 are obviously on a much more dramatic scale. We report on our continuing efforts to monitor the behavior and properties of Hubble's V19 in M33. Photometry has been carried out with the WIYN 3.5-m telescope and the 1.3-m RCT (Robotically Controlled Telescope) at KPNO. It is our hope that these observations will help solve the mystery of V19 and its unprecedented evolutionary behavior. We gratefully acknowledge NASA/HST grant and NSF/RUI grant AST1009903.

  20. Vasoactive Intestinal Polypeptide (VIP)-Expressing Neurons in the Suprachiasmatic Nucleus Provide Sparse GABAergic Outputs to Local Neurons with Circadian Regulation Occurring Distal to the Opening of Postsynaptic GABAA Ionotropic Receptors

    PubMed Central

    Fan, Junmei; Zeng, Hongkui; Olson, David P.; Huber, Kimberly M.

    2015-01-01

    GABAergic synaptic transmission plays an important role in resetting and synchronizing circadian rhythms in the suprachiasmatic nucleus (SCN). Although the circadian modulation of intrinsic membrane currents and biochemical signaling have been examined in the SCN, the modulation of specific synaptic pathways within the SCN is unexplored. In addition, little is known about the functional properties of these pathways, including which ones involve GABAA receptors (GABAA-Rs). In brain slices obtained from mice, we examined synaptic responses originating from the SCN neurons expressing vasoactive intestinal peptide (VIP+ neurons). Focusing on the local projection within the ventromedial SCN, we found that VIP+ afferents provided input onto 49% of neurons with a preference for VIP-negative (VIP−) neurons. Responses were mediated by GABAA-Rs. The projection was sparsely connected and preferentially targeted a subset of SCN neurons unrelated to postsynaptic VIP expression. For most aspects of VIP+ network output, there was no circadian regulation. Excitability and spontaneous firing of the presynaptic VIP+ neurons were unchanged between day and night, and their network connectivity and synaptic function up through the evoked synaptic conductance were also unchanged. On the other hand, VIP+ input onto VIP− neurons became less inhibitory at night suggesting a postsynaptic alteration in the coupling of GABAA-R conductances to action potential firing. These data suggest that components of the VIP network and its synaptic output up through GABAA-R opening are invariant during the circadian cycle, but the effect on action potential firing is modulated by postsynaptic processes occurring after GABAA-R channel opening. PMID:25653351

  1. Luminous and Variable Stars in M31 and M33. III. The Yellow and Red Supergiants and Post-red Supergiant Evolution

    NASA Astrophysics Data System (ADS)

    Gordon, Michael S.; Humphreys, Roberta M.; Jones, Terry J.

    2016-07-01

    Recent supernova (SN) and transient surveys have revealed an increasing number of non-terminal stellar eruptions. Though the progenitor class of these eruptions includes the most luminous stars, little is known of the pre-SN mechanics of massive stars in their most evolved state, thus motivating a census of possible progenitors. From surveys of evolved and unstable luminous star populations in nearby galaxies, we select a sample of yellow and red supergiant (RSG) candidates in M31 and M33 for review of their spectral characteristics and spectral energy distributions (SEDs). Since the position of intermediate- and late-type supergiants on the color-magnitude diagram can be heavily contaminated by foreground dwarfs, we employ spectral classification and multi-band photometry from optical and near-infrared surveys to confirm membership. Based on spectroscopic evidence for mass loss and the presence of circumstellar (CS) dust in their SEDs, we find that 30%-40% of the yellow supergiants are likely in a post-RSG state. Comparison with evolutionary tracks shows that these mass-losing, post-RSGs have initial masses between 20 and 40 M ⊙. More than half of the observed RSGs in M31 and M33 are producing dusty CS ejecta. We also identify two new warm hypergiants in M31, J004621.05+421308.06 and J004051.59+403303.00, both of which are likely in a post-RSG state. Based on observations obtained with the Large Binocular Telescope (LBT), an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are: The University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota, and University of Virginia.

  2. Two rare variations, D478N and D478E, that occur at the same amino acid residue in nicotinic acetylcholine receptor (nAChR) α2 subunit influence nAChR function.

    PubMed

    Dash, Bhagirathi; Li, Ming D

    2014-10-01

    There occur two rare variations, Asp(D)478Asn(N) and Asp(D)478Glu(E), in the putative cytoplasmic amphipathic α-helices of human nicotinic acetylcholine receptor (nAChR) α2 subunit as a result of mutation in the 1st (G → A: rs141072985) and 3rd (C → A: rs56344740) nucleotide of its 478th triplet codon (GAC). We assessed the effects of these two variations on the function of α2β2- and α2β4-nAChRs as they could alter the electronegativity and/or the structure of the cytoplasmic 'portals' (framed by subunit amphipathic α-helices) necessary for obligate ion permeation from extracellular space to cytoplasm. We injected decreasing ratio of subunit cRNAs (α:β; 10:1, 1:1 and 1:10) into Xenopus oocytes to express putative low-sensitivity (LS; 10:1), intermediate-sensitivity (IS; 1:1) and high sensitivity (HS; 1:10) isoforms of wild type and variant α2β2- and α2β4-nAChRs. Two-electrode voltage clamp analyses indicate that the agonist (ACh or nicotine) induced peak current responses (Imax) of α2β2-nAChR isoforms and those of α2β4-nAChR isoforms are increased (1.3-4.7-fold) as a result of D478E variation. The α2 subunit D478N variation only increases the Imax of IS (∼2-fold) or HS (1.4-2.1-fold) α2β2-nAChRs. Concentration-response curves constructed indicate no effect on agonist sensitivities of LS and HS isoforms of α2β2- or α2β4-nAChRs as a result of either variation in α2 subunit. Between the two variant nAChRs, α2(D478E)*-nAChR isoforms generally yield higher Imax than those of respective α2(D478N)*-nAChR isoforms. These effects could be attributed to alteration in cytoplasmic 'portals' and/or ion permeation through it owing to change in amino acid electronegativity (D → N) and side chain length (D → E) in nAChR α2 subunit.

  3. "Naturally occurring asbestos

    NASA Astrophysics Data System (ADS)

    Cagnard, F.; Lahondère, D.; Blein, O.; Lahfid, A.; Wille, G.

    2012-04-01

    The term asbestos refers to six silicate minerals from amphibole and serpentine groups. By definition, it consists in bundles of thin and flexible long fibers, with high-tensile strength, and chemical and heat resistance. In contrast to asbestos found within commercial products and mining, the specific term ''naturally occurring asbestos'' (NOA) refers to asbestiform minerals occurring within rocks or soils that can be released by human activities or weathering processes. The fact that the exposure to asbestos is related to lung pathologies is now widely demonstrated (e.g. asbestosis, mesothelioma and lung cancer). However, if health risks associated with exposure to NOA exist, they are not yet well documented. The crystallization of natural asbestos occurs in specific Mg-rich lithologies associated with peculiar structural and metamorphic conditions. By recognizing and combining such specific geologic criteria, the presence or the absence of asbestos in bedrock terrains can be reasonably predicted and maps of NOA hazard can be drawn. We present here new results of geological mapping and petrological study concerning the evaluation of the NOA hazard in the Alps and Corsica, in France. The three folds approach consists in (1) a determination of lithologies with potential NOA from a bibliographic compilation and extraction of target zones from a geological geodatabase (2) a geological mapping of the target zones followed by a petrological characterization of sampled asbestiform minerals in the laboratory (optical microscopy, TEM, SEM, and Raman spectroscopy technics), and (3) the drawing of the final map of NOA hazard, at regional-scale. Occurrence criteria can be retained as follows: 1. NOA are abundant in the internal zones of the Alps and Corsica, especially within ophiolitic complexes. Natural asbestos are mostly concentrated within ultramafic rocks but can also occur within basic lithologies such as Mg-metagabbros, metabasalts and meta-pillow-lavas, 2. Asbestos

  4. RCT photometry of the Hubble Classical Cepheid V19 in M33: Evidence for the Cessation of Pulsations - A Case of Stellar Evolution in Real Time

    NASA Astrophysics Data System (ADS)

    Engle, Scott G.; Guinan, Edward F.; Macri, Lucas; Pellerin, Ann

    2011-03-01

    We report on our continuing efforts to monitor the photometric behavior of Hubble's Variable Star V19 in the Triangulum Spiral Galaxy M33. B,V photometry has been carried out of this unusual 18th mag (previous) Cepheid with the 1.3-m RCT (Robotically Controlled Telescope) at KPNO. With time-series photometry, with a dedicated robotic telescope, we can hope to solve the mystery of V19 and its unprecedented evolutionary behavior. In the influential work "A Spiral Nebula as a Stellar System: Messier 33" (Hubble 1926) Edwin Hubble determined the distance to M33 by using 35 Cepheids he discovered. One of those Cepheids was designated V19. At that time observations revealed V19 to have a 54.7-day period and B-band (converted from photographic magnitudes) light amplitude of 1.1-mag. Its mean B-magnitude was 19.6 /-0.2. V19 properties were consistent with the Period-Luminosity Law for M33 derived by Hubble at that time. Follow-up observations in 1996-1997 as part of the DIRECT Program (Macri et al. 2001), however, revealed large and surprising changes in the properties of V19. Its mean B-magnitude had risen to 19.05 /-0.05 and its amplitude had decreased to less than 0.1-mag. The DIRECT study thoroughly checked for possible misclassifications of the variable or contamination by nearby objects, and found none. For all intents and purposes, V19 is no longer a Classical Cepheid, or at least varying below the detectable levels of the photometry. The only other well-documented instance of Cepheid pulsations declining over time is in the case of Polaris - whose V-band amplitude decreased from just over 0.1-mag to below 0.03-mag over the course of a century (Engle et al 2004). Also, a study of the visual magnitudes of Polaris over the past two millennia has shown a possible increase in brightness of 1-mag over the past 1000 years. The changes observed for V19 are obviously on a much more dramatic scale. We discuss the properties of this unusual (former) Cepheid and discuss

  5. CONSTRAINTS ON THE COMPACT OBJECT MASS IN THE ECLIPSING HIGH-MASS X-RAY BINARY XMMU J013236.7+303228 IN M 33

    SciTech Connect

    Bhalerao, Varun B.; Harrison, Fiona A.; Van Kerkwijk, Marten H.

    2012-09-20

    We present optical spectroscopic measurements of the eclipsing high-mass X-ray binary (HMXB) XMMU J013236.7+303228 in M 33. Based on spectra taken at multiple epochs of the 1.73 day binary orbital period we determine physical as well as orbital parameters for the donor star. We find the donor to be a B1.5IV subgiant with effective temperature T = 22, 000-23, 000 K. From the luminosity, temperature, and known distance to M 33 we derive a radius of R 8.9 {+-} 0.5 R{sub Sun }. From the radial-velocity measurements, we determine a velocity semi-amplitude of K{sub opt} = 63 {+-} 12 km s{sup -1}. Using the physical properties of the B star determined from the optical spectrum, we estimate the star's mass to be M{sub opt} = 11 {+-} 1 M{sub Sun }. Based on the X-ray spectrum, the compact companion is likely a neutron star, although no pulsations have yet been detected. Using the spectroscopically derived B star mass we find the neutron star companion mass to be M{sub X} = 2.0 {+-} 0.4 M{sub Sun }, consistent with the neutron star mass in the HMXB Vela X-1, but heavier than the canonical value of 1.4 M{sub Sun} found for many millisecond pulsars. We attempt to use as an additional constraint that the B star radius inferred from temperature, flux, and distance should equate to the Roche radius, since the system accretes by Roche lobe overflow. This leads to substantially larger masses, but by trying to apply the technique to known systems, we find that the masses are consistently overestimated. Attempting to account for that in our uncertainties, we derive M{sub X} = 2.2{sup +0.8}{sub -0.6} M{sub Sun} and M{sub opt} = 13 {+-} 4 M{sub Sun }. We conclude that precise constraints require detailed modeling of the shape of the Roche surface.

  6. Naturally occurring insecticides.

    PubMed Central

    Soloway, S B

    1976-01-01

    Naturally occurring insecticides are abundant and varied in their effects, though but a few are articles of commerce. Even for these, pyrethrum, nicotine, rotenone, hellebore, ryania, and sabadilla, there is a paucity of information on mammalian toxicology and environmental effects. In general, these materials are characterized favorably by low acute toxicity and ready dissipation in nature. Unfavorable aspects of natural insecticides are the contained mixture of active and inactive components and the low active ingredient content on a crop yield basis pointing to a high unit cost. Natural insecticides can serve additionally as leads to unnatural mimics, of which the commercially successful synthetic pyrethroids are prime examples. The chemical nature, relationship of insecticidal activity to chemical structure, occurrence, production, and utilization, registered uses, metabolism, and insect and mammalian toxicity are reviewed. PMID:789058

  7. Naturally Occurring Food Toxins

    PubMed Central

    Dolan, Laurie C.; Matulka, Ray A.; Burdock, George A.

    2010-01-01

    Although many foods contain toxins as a naturally-occurring constituent or, are formed as the result of handling or processing, the incidence of adverse reactions to food is relatively low. The low incidence of adverse effects is the result of some pragmatic solutions by the US Food and Drug Administration (FDA) and other regulatory agencies through the creative use of specifications, action levels, tolerances, warning labels and prohibitions. Manufacturers have also played a role by setting limits on certain substances and developing mitigation procedures for process-induced toxins. Regardless of measures taken by regulators and food producers to protect consumers from natural food toxins, consumption of small levels of these materials is unavoidable. Although the risk for toxicity due to consumption of food toxins is fairly low, there is always the possibility of toxicity due to contamination, overconsumption, allergy or an unpredictable idiosyncratic response. The purpose of this review is to provide a toxicological and regulatory overview of some of the toxins present in some commonly consumed foods, and where possible, discuss the steps that have been taken to reduce consumer exposure, many of which are possible because of the unique process of food regulation in the United States. PMID:22069686

  8. Naturally occurring food toxins.

    PubMed

    Dolan, Laurie C; Matulka, Ray A; Burdock, George A

    2010-09-01

    Although many foods contain toxins as a naturally-occurring constituent or, are formed as the result of handling or processing, the incidence of adverse reactions to food is relatively low. The low incidence of adverse effects is the result of some pragmatic solutions by the US Food and Drug Administration (FDA) and other regulatory agencies through the creative use of specifications, action levels, tolerances, warning labels and prohibitions. Manufacturers have also played a role by setting limits on certain substances and developing mitigation procedures for process-induced toxins. Regardless of measures taken by regulators and food producers to protect consumers from natural food toxins, consumption of small levels of these materials is unavoidable. Although the risk for toxicity due to consumption of food toxins is fairly low, there is always the possibility of toxicity due to contamination, overconsumption, allergy or an unpredictable idiosyncratic response. The purpose of this review is to provide a toxicological and regulatory overview of some of the toxins present in some commonly consumed foods, and where possible, discuss the steps that have been taken to reduce consumer exposure, many of which are possible because of the unique process of food regulation in the United States.

  9. They seldom occur alone.

    PubMed

    Crous, Pedro W; Groenewald, Johannes Z

    2016-11-01

    Species of Coleophoma have been reported as plant pathogenic, saprobic or endophytic on a wide host range. The genus is characterised by having pycnidial conidiomata, phialidic conidiogenous cells intermingled among paraphyses, and cylindrical conidia. Coleophoma has had a confusing taxonomic history with numerous synonyms, and its phylogeny has remained unresolved. The aim of the present study was to use a polyphasic approach incorporating morphology, ecology, and molecular data of the partial large subunit of nrDNA (LSU), the internal transcribed spacer region with intervening 5.8S nrDNA (ITS), partial β-tubulin (tub2), and translation elongation factor 1-alpha (tef1) gene sequences to resolve its taxonomy and phylogeny. Based on these results the genus was found to be polyphyletic, with taxa tentatively identified as Coleophoma clustering in Dothideomycetes and Leotiomycetes. Species corresponding to the concept of Coleophoma s.str. (Dermateaceae, Helotiales, Leotiomycetes) were found to form a distinct clade, with five new species. Furthermore, Coleophoma was found to be linked to the newly established sexual genus, Parafabraea, which is reduced to synonymy. Isolates occurring on Ilex aquifolium in the Netherlands also clustered in Dermateaceae, representing a novel genus, Davidhawksworthia. In the Dothideomycetes, several taxa clustered in Dothiora (Dothideaceae, Dothideales), which is shown to have Dothichiza and Hormonema-like asexual morphs, with four new species. Furthermore, Pseudocamaropycnis is introduced as a new genus (Mytilinidiaceae, Mytilinidiales), along with Briansuttonomyces (Didymellaceae, Pleosporales) and Dimorphosporicola (Pleosporaceae, Pleosporales). Copyright © 2016 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  10. APERTURE SYNTHESIS OBSERVATIONS OF CO, HCN, AND 89 GHz CONTINUUM EMISSION TOWARD NGC 604 IN M33: SEQUENTIAL STAR FORMATION INDUCED BY A SUPERGIANT H II REGION

    SciTech Connect

    Miura, Rie; Okumura, Sachiko K.; Kurono, Yasutaka; Nakanishi, Kouichiro; Tosaki, Tomoka; Tamura, Yoichi; Kuno, Nario; Kawabe, Ryohei; Sakamoto, Seiichi; Hasegawa, Takashi

    2010-12-01

    We present the results from new Nobeyama Millimeter Array observations of CO(1-0), HCN(1-0), and 89 GHz continuum emission toward NGC 604, known as the supergiant H II region in the nearby galaxy M33. Our high spatial resolution images (4.''2 x 2.''6, corresponding to 17 pc x 11 pc physical size) of CO emission allowed us to uncover 10 individual molecular clouds that have masses of (0.8-7.4) x10{sup 5} M{sub sun} and sizes of 5-29 pc, comparable to those of typical Galactic giant molecular clouds. Moreover, we detected for the first time HCN emission in the two most massive clouds and 89 GHz continuum emission at the rims of the 'H{alpha} shells'. The HCN and 89 GHz continuum emission are offset from the CO peak and are distributed in the direction of the central cluster. Three out of ten CO clouds are well correlated with the H{alpha} shells both in spatial and velocity domains, implying an interaction between molecular gas and the expanding H II region. The CO clouds show varieties in star formation efficiencies (SFEs), which are estimated from the 89 GHz emission and combination of H{alpha} and Spitzer 24 {mu}m data. Furthermore, we found that the SFEs decrease with increasing projected distance measured from the heart of the central OB star cluster in NGC 604, suggesting radial changes in the evolutionary stages of the molecular clouds in the course of stellar cluster formation. Our results provide further support to the picture of sequential star formation in NGC 604 initially proposed by Tosaki et al. with the higher spatially resolved molecular clouds, in which an isotropic expansion of the H II region pushes gases outward, which accumulates to form dense molecular clouds, and then induces massive star formations.

  11. Deep Canada-France-Hawaii Telescope photometric survey of the entire M33 galaxy - I. Catalogue of 36000 variable point sources

    NASA Astrophysics Data System (ADS)

    Hartman, J. D.; Bersier, D.; Stanek, K. Z.; Beaulieu, J.-P.; Kaluzny, J.; Marquette, J.-B.; Stetson, P. B.; Schwarzenberg-Czerny, A.

    2006-09-01

    We have conducted a variability survey of the Local Group galaxy M33, using g',r', and i' observations from 27 nights spanning 17 months, made with the MegaPrime/MegaCam instrument on the 3.6-m Canada-France-Hawaii Telescope (CFHT). We identify more than 36000 variable sources with g', r', i' <~ 24, out of approximately two million point sources in a 1-deg2 field of view. This increases the number of known variables in this galaxy by more than a factor of 20. In this paper, we provide a brief description of the data and a general overview of the variable star population which includes more than 1300 candidate variable blue and red supergiant stars, more than 2000 Cepheids, and more than 19000 long-period variable asymptotic giant branch and red giant branch stars. Based on observations obtained with the MegaPrime/MegaCam, a joint project of Canada-France-Hawaii Telescope (CFHT) and CEA/DAPNIA, at the CFHT which is operated by the National Research Council (NRC) of Canada, the Institut National des Science de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. E-mail: jhartman@cfa.harvard.edu (JDH); dfb@astro.livjm.ac.uk (DB); kstanek@astronomy.ohio-state.edu (KZS); beaulieu@iap.fr (J-PB); jka@camk.edu.pl (JK); marquette@iap.fr (J-BM); Peter.Stetson@nrc.ca (PBS); alex@camk.edu.pl (AS-C)

  12. Commonly occurring plant flavonoids have estrogenic activity.

    PubMed

    Miksicek, R J

    1993-07-01

    A remarkable diversity of naturally occurring and synthetic compounds have been shown to mimic the biological effects of 17 beta-estradiol by virtue of their ability to bind to and activate the nuclear estrogen receptor. This report extends the family of nonsteroidal estrogens to include several multiply hydroxylated chalcones, flavanones, and flavones. The hormone-like activity of these natural plant products is indicated by their ability to stimulate an estrogen receptor-dependent transcriptional response and to promote growth of estrogen-dependent MCF7 cells in culture. The transcriptional response can be inhibited by the steroidal estrogen antagonist ICI-164,384 and is specific for the estrogen receptor. Evidence is presented to show that selected hydroxylated flavonoids interact directly with the estrogen receptor, based on their ability to compete for the binding of 17 beta-[3H]estradiol to the receptor in cell-free extracts. These compounds are less active, on a molar basis, than 17 beta-estradiol or the synthetic dihydroxystilbene estrogens, but they have potencies comparable to those of other known phytoestrogens. Together, these findings broaden our understanding of the structure-activity relationships for nonsteroidal estrogens and present a series of new chemical prototypes for the future development of potentially useful agonists and antagonists for this nuclear receptor. The wide distribution of weakly estrogenic flavonoid pigments in food crops and medicinal plants raises additional questions about the possible health risks and benefits of these compounds, meriting closer examination of their presence in the human diet.

  13. Serotonin 5-HT3 Receptor-Mediated Vomiting Occurs via the Activation of Ca2+/CaMKII-Dependent ERK1/2 Signaling in the Least Shrew (Cryptotis parva)

    PubMed Central

    Zhong, Weixia; Hutchinson, Tarun E.; Chebolu, Seetha; Darmani, Nissar A.

    2014-01-01

    Stimulation of 5-HT3 receptors (5-HT3Rs) by 2-methylserotonin (2-Me-5-HT), a selective 5-HT3 receptor agonist, can induce vomiting. However, downstream signaling pathways for the induced emesis remain unknown. The 5-HT3R channel has high permeability to extracellular calcium (Ca2+) and upon stimulation allows increased Ca2+ influx. We examined the contribution of Ca2+/calmodulin-dependent protein kinase IIα (Ca2+/CaMKIIα), interaction of 5-HT3R with calmodulin, and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling to 2-Me-5-HT-induced emesis in the least shrew. Using fluo-4 AM dye, we found that 2-Me-5-HT augments intracellular Ca2+ levels in brainstem slices and that the selective 5-HT3R antagonist palonosetron, can abolish the induced Ca2+ signaling. Pre-treatment of shrews with either: i) amlodipine, an antagonist of L-type Ca2+ channels present on the cell membrane; ii) dantrolene, an inhibitor of ryanodine receptors (RyRs) Ca2+-release channels located on the endoplasmic reticulum (ER); iii) a combination of their less-effective doses; or iv) inhibitors of CaMKII (KN93) and ERK1/2 (PD98059); dose-dependently suppressed emesis caused by 2-Me-5-HT. Administration of 2-Me-5-HT also significantly: i) enhanced the interaction of 5-HT3R with calmodulin in the brainstem as revealed by immunoprecipitation, as well as their colocalization in the area postrema (brainstem) and small intestine by immunohistochemistry; and ii) activated CaMKIIα in brainstem and in isolated enterochromaffin cells of the small intestine as shown by Western blot and immunocytochemistry. These effects were suppressed by palonosetron. 2-Me-5-HT also activated ERK1/2 in brainstem, which was abrogated by palonosetron, KN93, PD98059, amlodipine, dantrolene, or a combination of amlodipine plus dantrolene. However, blockade of ER inositol-1, 4, 5-triphosphate receptors by 2-APB, had no significant effect on the discussed behavioral and biochemical parameters. This study demonstrates

  14. Serotonin 5-HT3 receptor-mediated vomiting occurs via the activation of Ca2+/CaMKII-dependent ERK1/2 signaling in the least shrew (Cryptotis parva).

    PubMed

    Zhong, Weixia; Hutchinson, Tarun E; Chebolu, Seetha; Darmani, Nissar A

    2014-01-01

    Stimulation of 5-HT3 receptors (5-HT3Rs) by 2-methylserotonin (2-Me-5-HT), a selective 5-HT3 receptor agonist, can induce vomiting. However, downstream signaling pathways for the induced emesis remain unknown. The 5-HT3R channel has high permeability to extracellular calcium (Ca(2+)) and upon stimulation allows increased Ca(2+) influx. We examined the contribution of Ca(2+)/calmodulin-dependent protein kinase IIα (Ca(2+)/CaMKIIα), interaction of 5-HT3R with calmodulin, and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling to 2-Me-5-HT-induced emesis in the least shrew. Using fluo-4 AM dye, we found that 2-Me-5-HT augments intracellular Ca(2+) levels in brainstem slices and that the selective 5-HT3R antagonist palonosetron, can abolish the induced Ca(2+) signaling. Pre-treatment of shrews with either: i) amlodipine, an antagonist of L-type Ca(2+) channels present on the cell membrane; ii) dantrolene, an inhibitor of ryanodine receptors (RyRs) Ca2+-release channels located on the endoplasmic reticulum (ER); iii) a combination of their less-effective doses; or iv) inhibitors of CaMKII (KN93) and ERK1/2 (PD98059); dose-dependently suppressed emesis caused by 2-Me-5-HT. Administration of 2-Me-5-HT also significantly: i) enhanced the interaction of 5-HT3R with calmodulin in the brainstem as revealed by immunoprecipitation, as well as their colocalization in the area postrema (brainstem) and small intestine by immunohistochemistry; and ii) activated CaMKIIα in brainstem and in isolated enterochromaffin cells of the small intestine as shown by Western blot and immunocytochemistry. These effects were suppressed by palonosetron. 2-Me-5-HT also activated ERK1/2 in brainstem, which was abrogated by palonosetron, KN93, PD98059, amlodipine, dantrolene, or a combination of amlodipine plus dantrolene. However, blockade of ER inositol-1, 4, 5-triphosphate receptors by 2-APB, had no significant effect on the discussed behavioral and biochemical parameters. This study

  15. Myasis occuring in a neonate

    PubMed Central

    Obasa, Temitope O.; Sowunmi, Funmilola Olusola

    2012-01-01

    Myasis is the infestation of skin by larvae or maggots of a variety of flies. It is a condition that occurs more commonly in adults who are living and/or have visited tropical countries. It rarely occurs in neonates, and even when seen, only few larvae are extracted. This case report describes myasis occurring in an 11-day-old female who had 47 larvae in her skin. PMID:23355934

  16. Nipah virus entry can occur by macropinocytosis

    SciTech Connect

    Pernet, Olivier; Pohl, Christine; Ainouze, Michelle; Kweder, Hasan; Buckland, Robin

    2009-12-20

    Nipah virus (NiV) is a zoonotic biosafety level 4 paramyxovirus that emerged recently in Asia with high mortality in man. NiV is a member, with Hendra virus (HeV), of the Henipavirus genus in the Paramyxoviridae family. Although NiV entry, like that of other paramyxoviruses, is believed to occur via pH-independent fusion with the host cell's plasma membrane we present evidence that entry can occur by an endocytic pathway. The NiV receptor ephrinB2 has receptor kinase activity and we find that ephrinB2's cytoplasmic domain is required for entry but is dispensable for post-entry viral spread. The mutation of a single tyrosine residue (Y304F) in ephrinB2's cytoplasmic tail abrogates NiV entry. Moreover, our results show that NiV entry is inhibited by constructions and drugs specific for the endocytic pathway of macropinocytosis. Our findings could potentially permit the rapid development of novel low-cost antiviral treatments not only for NiV but also HeV.

  17. Repetition Blindness Occurs in Nonwords

    ERIC Educational Resources Information Center

    Harris, Catherine L.; Morris, Alison L.

    2004-01-01

    Theorists have predicted that repetition blindness (RB) should be absent for nonwords because they do not activate preexisting mental types. The authors hypothesized that RB would be observed for nonwords because RB can occur at a sublexical level. Four experiments showed that RB is observed for word-nonword pairs (noon noof), orthographically…

  18. Mucinous carcinoma occurring in the male breast.

    PubMed

    Ishida, Mitsuaki; Umeda, Tomoko; Kawai, Yuki; Mori, Tsuyoshi; Kubota, Yoshihiro; Abe, Hajime; Iwai, Muneo; Yoshida, Keiko; Kagotani, Akiko; Tani, Tohru; Okabe, Hidetoshi

    2014-02-01

    Male breast carcinoma is an uncommon neoplasm, accounting for 0.6% of all breast carcinomas. Invasive ductal carcinoma of no special type is the most common type of male breast carcinoma, and mucinous carcinoma occurring in the male breast is extremely rare. In the present study, we report a case of mucinous carcinoma of the male breast and discuss the clinicopathological features of this type of tumor. A 63-year-old Japanese male presented with a gradually enlarged nodule in the right breast. The resected breast specimen revealed pure mucinous carcinoma and immunohistochemical analyses demonstrated that tumor cells were positive for estrogen receptor (ER), but negative for progesterone receptor (PgR). In addition, HER2 expression was not amplified. Pure mucinous carcinoma is generally associated with a low incidence of lymph node or distant metastases, and excellent disease-free survival in females. However, certain cases of this type of tumor with axillary lymph node metastasis in the male breast have been reported. In addition, the immunoprofiles of mucinous carcinoma in males are fundamentally the same as those in females. More than 90% of cases show positive immunoreactivity for ER and/or PgR, and HER2 expression is not amplified. However, it has been reported that breast cancer in males is more frequently positive for ER than in females, and has less HER2 overexpression. The high rate of hormone receptor-positive breast cancer in males is considered to be due to similar conditions as those in breast cancer in postmenopausal women. The pathogenesis of male breast carcinoma, including mucinous carcinoma, remains unclear; therefore, additional clinicopathological studies are required.

  19. Naturally Occurring Radioactive Materials (NORM)

    SciTech Connect

    Gray, P.

    1997-02-01

    This paper discusses the broad problems presented by Naturally Occuring Radioactive Materials (NORM). Technologically Enhanced naturally occuring radioactive material includes any radionuclides whose physical, chemical, radiological properties or radionuclide concentration have been altered from their natural state. With regard to NORM in particular, radioactive contamination is radioactive material in an undesired location. This is a concern in a range of industries: petroleum; uranium mining; phosphorus and phosphates; fertilizers; fossil fuels; forestry products; water treatment; metal mining and processing; geothermal energy. The author discusses in more detail the problem in the petroleum industry, including the isotopes of concern, the hazards they present, the contamination which they cause, ways to dispose of contaminated materials, and regulatory issues. He points out there are three key programs to reduce legal exposure and problems due to these contaminants: waste minimization; NORM assesment (surveys); NORM compliance (training).

  20. Polyion complex libraries possessing naturally occurring differentiation for pattern-based protein discrimination.

    PubMed

    Tomita, Shunsuke; Yoshimoto, Keitaro

    2013-11-14

    Polyion complexes with naturally occurring differentiation of enzymes serve to create receptor libraries with high differentiability and lower synthetic demands for pattern-based protein discrimination.

  1. Detecting change as it occurs

    NASA Technical Reports Server (NTRS)

    Radok, Uwe; Brown, Timothy J.

    1992-01-01

    Traditionally climate changes have been detected from long series of observations and long after they have happened. Our 'inverse sequential' procedure, for detecting change as soon as it occurs, describes the existing or most recent data by their frequency distribution. Its parameter(s) are estimated both from the existing set of observations and from the same set augmented by 1,2,....j new observations. Individual-value probability products ('likelihoods') are used to form ratios which yield two probabilities for erroneously accepting the existing parameter(s) as valid for the augmented data set, and vice versa. A genuine parameter change is signaled when these probabilities (or a more stable compound probability) show a progressive decrease. New parameter values can then be estimated from the new observations alone using standard statistical techniques. The inverse sequential procedure will be illustrated for global annual mean temperatures (assumed normally distributed), and for annual numbers of North Atlantic hurricanes (assumed to represent Poisson distributions). The procedure was developed, but not yet tested, for linear or exponential trends, and for chi-squared means or degrees of freedom, a special measure of autocorrelation.

  2. When Yawning Occurs in Elephants

    PubMed Central

    Rossman, Zoë T.; Hart, Benjamin L.; Greco, Brian J.; Young, Debbie; Padfield, Clare; Weidner, Lisa; Gates, Jennifer; Hart, Lynette A.

    2017-01-01

    Yawning is a widely recognized behavior in mammalian species. One would expect that elephants yawn, although to our knowledge, no one has reported observations of yawning in any species of elephant. After confirming a behavioral pattern matching the criteria of yawning in two Asian elephants (Elephas maximus) in a zoological setting, this study was pursued with nine captive African elephants (Loxodonta africana) at a private reserve in the Western Cape, South Africa, the Knysna Elephant Park. Observations were made in June–September and in December. In the daytime, handlers managed seven of the elephants for guided interactions with visitors. At night, all elephants were maintained in a large enclosure with six having limited outdoor access. With infrared illumination, the elephants were continuously recorded by video cameras. During the nights, the elephants typically had 1–3 recumbent sleeping/resting bouts, each lasting 1–2 h. Yawning was a regular occurrence upon arousal from a recumbency, especially in the final recumbency of the night. Yawning was significantly more frequent in some elephants. Yawning was rare during the daytime and during periods of standing around in the enclosure at night. In six occurrences of likely contagious yawning, one elephant yawned upon seeing another elephant yawning upon arousal from a final recumbency; we recorded the sex and age category of the participants. The generality of yawning in both African and Asian elephants in other environments was documented in video recordings from 39 zoological facilities. In summary, the study provides evidence that yawning does occur in both African and Asian elephants, and in African elephants, yawning was particularly associated with arousal from nighttime recumbencies. PMID:28293560

  3. When Yawning Occurs in Elephants.

    PubMed

    Rossman, Zoë T; Hart, Benjamin L; Greco, Brian J; Young, Debbie; Padfield, Clare; Weidner, Lisa; Gates, Jennifer; Hart, Lynette A

    2017-01-01

    Yawning is a widely recognized behavior in mammalian species. One would expect that elephants yawn, although to our knowledge, no one has reported observations of yawning in any species of elephant. After confirming a behavioral pattern matching the criteria of yawning in two Asian elephants (Elephas maximus) in a zoological setting, this study was pursued with nine captive African elephants (Loxodonta africana) at a private reserve in the Western Cape, South Africa, the Knysna Elephant Park. Observations were made in June-September and in December. In the daytime, handlers managed seven of the elephants for guided interactions with visitors. At night, all elephants were maintained in a large enclosure with six having limited outdoor access. With infrared illumination, the elephants were continuously recorded by video cameras. During the nights, the elephants typically had 1-3 recumbent sleeping/resting bouts, each lasting 1-2 h. Yawning was a regular occurrence upon arousal from a recumbency, especially in the final recumbency of the night. Yawning was significantly more frequent in some elephants. Yawning was rare during the daytime and during periods of standing around in the enclosure at night. In six occurrences of likely contagious yawning, one elephant yawned upon seeing another elephant yawning upon arousal from a final recumbency; we recorded the sex and age category of the participants. The generality of yawning in both African and Asian elephants in other environments was documented in video recordings from 39 zoological facilities. In summary, the study provides evidence that yawning does occur in both African and Asian elephants, and in African elephants, yawning was particularly associated with arousal from nighttime recumbencies.

  4. Partial Functional Complementation between Human and Mouse Cytomegalovirus Chemokine Receptor Homologues▿

    PubMed Central

    Farrell, Helen E.; Abraham, Alexander M.; Cardin, Rhonda D.; Sparre-Ulrich, Alexander H.; Rosenkilde, Mette M.; Spiess, Katja; Jensen, Tine H.; Kledal, Thomas N.; Davis-Poynter, Nicholas

    2011-01-01

    The human cytomegalovirus (CMV) proteins US28 and UL33 are homologous to chemokine receptors (CKRs). Knockout of the mouse CMV M33 protein (UL33 homologue) results in substantial attenuation of salivary gland infection/replication and reduced efficiency of reactivation from tissue explants. M33-mediated G protein-coupled signaling is critical for the salivary gland phenotype. In this report, we demonstrate that US28 and (to a lesser degree) UL33 restore reactivation from tissue explants and partially restore replication in salivary glands (compared to a signaling-deficient M33 mutant). These studies provide a novel small animal model for evaluation of therapies targeting the human CMV CKRs. PMID:21490099

  5. Elevation of Alanine Aminotransferase Activity Occurs after Activation of the Cell-Death Signaling Initiated by Pattern-Recognition Receptors ‎but before Activation of Cytolytic Effectors in NK or CD8+ T Cells in the Liver During Acute HCV Infection

    PubMed Central

    Choi, Youkyung H.; Jin, Nancy; Kelly, Fiona; Sakthivel, SenthilKumar K.; Yu, Tianwei

    2016-01-01

    Pattern-recognition receptors (PRRs) promote host defenses against HCV infection by binding to their corresponding adapter molecules leading to the initiation of innate immune responses including cell death. We investigated the expression of PRR genes, biomarkers of liver cell-death, and T cell and NK cell activation/inhibition-related genes in liver and serum obtained from three experimentally infected chimpanzees with acute HCV infection, and analyzed the correlation between gene expression levels and clinical profiles. Our results showed that expression of hepatic RIG-I, TLR3, TLR7, 2OAS1, and CXCL10 mRNAs was upregulated as early as 7 days post-inoculation and peaked 12 to 83 days post-inoculation. All of the three HCV infected chimpanzees exhibited significant elevations of serum alanine aminotransferase (ALT) activity between 70 and 95 days after inoculation. Elevated levels of serum cytokeratin 18 (CK-18) and caspases 3 and 7 activity coincided closely with the rise of ALT activity, and were preceded by significant increases in levels of caspase 3 and caspase 7 mRNAs in the liver. Particularly we found that significant positive auto-correlations were observed between RIG-I, TLR3, CXCL10, 2OAS1, and PD-L1 mRNA and ALT activity at 3 to 12 days before the peak of ALT activity. However, we observed substantial negative auto-correlations between T cell and NK cell activation/inhibition-related genes and ALT activity at 5 to 32 days after the peak of ALT activity. Our results indicated cell death signaling is preceded by early induction of RIG-I, TLR3, 2OAS1, and CXCL10 mRNAs which leads to elevation of ALT activity and this signaling pathway occurs before the activation of NK and T cells during acute HCV infection. Our study suggests that PRRs and type I IFN response may play a critical role in development of liver cell injury related to viral clearance during acute HCV infection. PMID:27788241

  6. Luminous and Variable Stars in M31 and M33. IV. Luminous Blue Variables, Candidate LBVs, B[e] Supergiants, and the Warm Hypergiants: How to Tell Them Apart

    NASA Astrophysics Data System (ADS)

    Humphreys, Roberta M.; Gordon, Michael S.; Martin, John C.; Weis, Kerstin; Hahn, David

    2017-02-01

    In this series of papers we have presented the results of a spectroscopic survey of luminous stars in the nearby spirals M31 and M33. Here, we present spectroscopy of 132 additional stars. Most have emission-line spectra, including luminous blue variables (LBVs) and candidate LBVs, Fe ii emission line stars, the B[e] supergiants, and the warm hypergiants. Many of these objects are spectroscopically similar and are often confused with each other. We examine their similarities and differences and propose the following guidelines that can be used to help distinguish these stars in future work. (1) The B[e] supergiants have emission lines of [O i] and [Fe ii] in their spectra. Most of the spectroscopically confirmed sgB[e] stars also have warm circumstellar dust in their spectral energy distributions (SEDs). (2) Confirmed LBVs do not have the [O i] emission lines in their spectra. Some LBVs have [Fe ii] emission lines, but not all. Their SEDs show free–free emission in the near-infrared but no evidence for warm dust. Their most important and defining characteristic is the S Dor-type variability. (3) The warm hypergiants spectroscopically resemble the LBVs in their dense wind state and the B[e] supergiants. However, they are very dusty. Some have [Fe ii] and [O i] emission in their spectra like the sgB[e] stars, but are distinguished by their A- and F-type absorption-line spectra. In contrast, the B[e] supergiant spectra have strong continua and few if any apparent absorption lines. Candidate LBVs should share the spectral characteristics of the confirmed LBVs with low outflow velocities and the lack of warm circumstellar dust. Based on observations with the Multiple Mirror Telescope, a joint facility of the Smithsonian Institution and the University of Arizona and on observations obtained with the Large Binocular Telescope (LBT), an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are The University of

  7. Breast carcinomas occurring in young women (< 35 years) are different.

    PubMed

    Walker, R A; Lees, E; Webb, M B; Dearing, S J

    1996-12-01

    One hundred and sixty-three breast carcinomas occurring in women aged between 26 and 44 years were examined for pathological features, oestrogen and progesterone receptor status, proliferation as determined by Ki-67 labelling and the presence of c-erbB-2 and p53 protein, and were compared with a control group of carcinomas from women in the 50-67 years age group. Carcinomas occurring in women aged under 35 years had a significantly high incidence of being poorly differentiated and of having high proliferation rates. This group also had a significantly high incidence of p53 protein staining. Carcinomas in the under 30 years age group had a lower incidence of oestrogen and progesterone receptor positivity. No differences were found in c-erbB-2-positive staining between the groups. Infiltrating lobular carcinomas were only identified in women aged 40 years and over. There was a higher incidence of a family history in the 35-44 years age group (18%) than in the under 35 years age group (11%). Breast carcinomas occurring in women aged under 35 years are more aggressive. An important finding is the high incidence of p53 positivity, which may indicate genetic instability.

  8. Estrogenic activity of naturally occurring anthocyanidins.

    PubMed

    Schmitt, E; Stopper, H

    2001-01-01

    Anthocyanins, which are natural plant pigments from the flavonoid family, represent substantial constituents of the human diet. Because some other bioflavonoids are known to have estrogenic activity, the aim of this study was to determine the estrogenic activity of the anthocyanine aglycones. Binding affinity to the estrogen receptor-alpha was 10,000- to 20,000-fold lower than that of the endogenous estrogen estradiol. In the estrogen receptor-positive cell line MCF-7, the anthocyanidins induced expression of a reporter gene. The tested anthocyanidins showed estrogen-inducible cell proliferation in two cell lines (MCF-7 and BG-1), but not in the receptor-negative human breast cancer cell line MDA-MB-231. The phytoestrogen-induced cell proliferation could be blocked by addition of the receptor antagonist 4-hydroxytamoxifen. Combination treatments with the endogenous estrogen estradiol resulted in a reduction of estradiol-induced cell proliferation. Overall, the tested anthocyanidins exert estrogenic activity, which might play a role in altering the development of hormone-dependent adverse effects.

  9. Naturally Occurring Radon and 120(h) transfers

    EPA Pesticide Factsheets

    This page contains a discussion regarding how the presence of naturally occurring radon on closing military bases affects the United States' ability to transfer parcels under §120(h) (3) and §120(h) (4).

  10. TENORM (Technologically Enhanced Naturally Occurring Radioactive Materials)

    MedlinePlus

    ... The major industrial sectors which generate TENORM are: Mining. Energy production. Water treatment. Consumer products . Learn more ... Technologically Enhanced Naturally Occurring Radioactive Materials From Uranium Mining, Volume 1: Mining and Reclamation Background, and Volume ...

  11. Allergies and Asthma: They Often Occur Together

    MedlinePlus

    ... occur together. The same substances that trigger your hay fever symptoms, such as pollen, dust mites and pet ... a major risk factor for allergic asthma. Having hay fever or other allergies yourself also increases your risk ...

  12. Molten Metal Explosions are Still Occurring

    DTIC Science & Technology

    2009-02-01

    recycling plant. Another recent 665 Light Metals 2009 Edited by: Geoff Bearne TMS (The Minerals, Metals & Materials Society), 2009 catastrophic...occurred recently in a recycling plant casting small ingots over a water tank. An explosion occurred that extensively damaged the machine and...have been held in Europe as a joint activity with the European Aluminium Association (EAA) and the International Aluminium Institute (IAI). These

  13. Trichotillomania and Co-occurring Anxiety

    PubMed Central

    Grant, Jon E.; Redden, Sarah A.; Leppink, Eric W.; Chamberlain, Samuel R.

    2017-01-01

    Background Trichotillomania appears to be a fairly common disorder, with high rates of co-occurring anxiety disorders. Many individuals with trichotillomania also report that pulling worsens during periods of increased anxiety. Even with these clinical links to anxiety, little research has explored whether trichotillomania with co-occurring anxiety is a meaningful subtype. Methods 165 adults with trichotillomania were examined on a variety of clinical measures including symptom severity, functioning, and comorbidity. Participants also underwent cognitive testing assessing motor inhibition and cognitive flexibility. Clinical features and cognitive functioning were compared between those with current co-occurring anxiety disorders (i.e. social anxiety, generalized anxiety disorder, panic disorder, and anxiety disorder NOS) (n=38) and those with no anxiety disorder (n=127). Results Participants with trichotillomania and co-occurring anxiety reported significantly worse hair pulling symptoms, were more likely to have co-occurring depression, and were more likely to have a first-degree relative with obsessive compulsive disorder. Those with anxiety disorders also exhibited significantly worse motor inhibitory performance on a task of motor inhibition (stop-signal task). Conclusions This study suggests that anxiety disorders affect the clinical presentation of hair pulling behavior. Further research is needed to validate our findings and to consider whether treatments should be specially tailored differently for adults with trichotillomania who have co-occurring anxiety disorders, or more pronounced cognitive impairment. PMID:27668531

  14. Interactions between effectors linked to serotonin receptors.

    PubMed

    Berg, K A; Maayani, S; Clarke, W P

    1998-12-15

    In general, there are two types of interactions between effector signaling pathways. "Homologous" interactions are those that occur within a receptor system to alter its own responsiveness, for example the loss of responsiveness (desensitization) that can occur upon agonist occupancy of a receptor. "Heterologous" interactions are those that occur between different receptor systems where the responsiveness of one receptor system is regulated (positively or negatively) by activation of another receptor system (i.e., "cross-talk"). Many, if not all receptors, couple to multiple cellular effector pathways and alterations in the responsiveness of a receptor system can be effector pathway-dependent which underscores the importance of studying each effector coupled to a receptor. Regulation of receptor system responsiveness, and consequently the efficacy of drugs, is a highly dynamic process. Perhaps by exploiting these interactions, new targets for pharmacotherapy may be uncovered which will provide for increased efficacy and specificity of drug action.

  15. Young Children's Reports of when Learning Occurred

    ERIC Educational Resources Information Center

    Tang, Connie M.; Bartsch, Karen; Nunez, Narina

    2007-01-01

    This study investigated young children's reports of when learning occurred. A total of 96 4-, 5-, and 6-year-olds were recruited from suburban preschools and elementary schools. The children learned an animal fact and a body movement. A week later, children learned another animal fact and another body movement and then answered questions about…

  16. Necrobiotic xanthogranuloma occurring in an eyelid scar.

    PubMed

    Rayner, S A; Duncombe, A S; Keefe, M; Theaker, J; Manners, R M

    2008-01-01

    We present a case report of necrobiotic xanthogranuloma (NXG) in a 76-year-old Caucasian lady occurring as a nodule in a blepharoplasty scar. NXG is a rare histiocytic disease with progressive orbital and systemic features. Management options of excision biopsy or chemotherapy are discussed.

  17. Young Children's Reports of when Learning Occurred

    ERIC Educational Resources Information Center

    Tang, Connie M.; Bartsch, Karen; Nunez, Narina

    2007-01-01

    This study investigated young children's reports of when learning occurred. A total of 96 4-, 5-, and 6-year-olds were recruited from suburban preschools and elementary schools. The children learned an animal fact and a body movement. A week later, children learned another animal fact and another body movement and then answered questions about…

  18. Phonetic Recalibration Only Occurs in Speech Mode

    ERIC Educational Resources Information Center

    Vroomen, Jean; Baart, Martijn

    2009-01-01

    Upon hearing an ambiguous speech sound dubbed onto lipread speech, listeners adjust their phonetic categories in accordance with the lipread information (recalibration) that tells what the phoneme should be. Here we used sine wave speech (SWS) to show that this tuning effect occurs if the SWS sounds are perceived as speech, but not if the sounds…

  19. Preferential flow occurs in unsaturated conditions

    USGS Publications Warehouse

    Nimmo, John R.

    2012-01-01

    Because it commonly generates high-speed, high-volume flow with minimal exposure to solid earth materials, preferential flow in the unsaturated zone is a dominant influence in many problems of infiltration, recharge, contaminant transport, and ecohydrology. By definition, preferential flow occurs in a portion of a medium – that is, a preferred part, whether a pathway, pore, or macroscopic subvolume. There are many possible classification schemes, but usual consideration of preferential flow includes macropore or fracture flow, funneled flow determined by macroscale heterogeneities, and fingered flow determined by hydraulic instability rather than intrinsic heterogeneity. That preferential flow is spatially concentrated associates it with other characteristics that are typical, although not defining: it tends to be unusually fast, to transport high fluxes, and to occur with hydraulic disequilibrium within the medium. It also has a tendency to occur in association with large conduits and high water content, although these are less universal than is commonly assumed. Predictive unsaturated-zone flow models in common use employ several different criteria for when and where preferential flow occurs, almost always requiring a nearly saturated medium. A threshold to be exceeded may be specified in terms of the following (i) water content; (ii) matric potential, typically a value high enough to cause capillary filling in a macropore of minimum size; (iii) infiltration capacity or other indication of incipient surface ponding; or (iv) other conditions related to total filling of certain pores. Yet preferential flow does occur without meeting these criteria. My purpose in this commentary is to point out important exceptions and implications of ignoring them. Some of these pertain mainly to macropore flow, others to fingered or funneled flow, and others to combined or undifferentiated flow modes.

  20. Could a megaquake occur in the Himalayas?

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2011-12-01

    GPS measurements of crustal deformation are showing that a magnitude 9 earthquake could occur in the Himalayas. Roger Bilham of the University of Colorado at Boulder reported at the AGU Fall Meeting that the region, known to be seismically active, could produce a much larger earthquake than previously thought. Bilham and colleagues used GPS to monitor rates of crustal deformation in the Himalayas. They found that the potential rupture zone is larger than scientists had believed—the region where strain is building is twice as wide as expected. Previous estimates, which were based on the historical earthquake record, suggested that the largest earthquake that would occur in the region would have a magnitude in the low 8s. Such an earthquake could be devastating—the Kashmir valley region alone is home to 6 million people.

  1. Naturally Occuring Fish Poisons from Plants

    NASA Astrophysics Data System (ADS)

    Cannon, Jonathan G.; Burton, Robert A.; Wood, Steven G.; Owen, Noel L.

    2004-10-01

    Since prehistoric times, cultures throughout the world have used piscicidal (fish poisoning) plants for fishing. In recent times, scientists have identified many of the plant compounds responsible for killing the fish and have found that these compounds possess other important biological properties, such as insecticidal and anti-cancer activities. This article reviews some of the chemical research that has been performed on naturally occurring fish poisons, including plant sources, methods of use, toxicity, and mechanisms of action of piscicides.

  2. spin pumping occurred under nonlinear spin precession

    NASA Astrophysics Data System (ADS)

    Zhou, Hengan; Fan, Xiaolong; Ma, Li; Zhou, Shiming; Xue, Desheng

    Spin pumping occurs when a pure-spin current is injected into a normal metal thin layer by an adjacent ferromagnetic metal layer undergoing ferromagnetic resonance, which can be understood as the inverse effect of spin torque, and gives access to the physics of magnetization dynamics and damping. An interesting question is that whether spin pumping occurring under nonlinear spin dynamics would differ from linear case. It is known that nonlinear spin dynamics differ distinctly from linear response, a variety of amplitude dependent nonlinear effect would present. It has been found that for spin precession angle above a few degrees, nonlinear damping term would present and dominated the dynamic energy/spin-moment dissipation. Since spin pumping are closely related to the damping process, it is interesting to ask whether the nonlinear damping term could be involved in spin pumping process. We studied the spin pumping effect occurring under nonlinear spin precession. A device which is a Pt/YIG microstrip coupled with coplanar waveguide was used. High power excitation resulted in spin precession entering in a nonlinear regime. Foldover resonance lineshape and nonlinear damping have been observed. Based on those nonlinear effects, we determined the values of the precession cone angles, and the maximum cone angle can reach a values as high as 21.5 degrees. We found that even in nonlinear regime, spin pumping is still linear, which means the nonlinear damping and foldover would not affect spin pumping process.

  3. Naturally occurring antimicrobials for minimally processed foods.

    PubMed

    Davidson, P Michael; Critzer, Faith J; Taylor, T Matthew

    2013-01-01

    Natural antimicrobials are gaining increased interest from researchers and food manufacturers alike seeking to discover label-friendly alternatives to the widely implemented synthetic compounds. Naturally occurring antimicrobials can be applied directly to food to protect food quality, extend food shelf life by inhibiting or inactivating spoilage microorganisms, and improve food safety by inhibiting or inactivating food-borne pathogens. There are a great number of natural antimicrobials derived from animal, plant, and microbial sources. This manuscript reviews their efficacy against spoilage and pathogenic organisms, their methods of evaluation, and their application in various foods as well as the development of novel delivery systems and incorporation with other hurdles.

  4. Muscle damage occurring in wheelchair sports people.

    PubMed

    Ide, M; Ogata, H; Kobayashi, M; Wada, F

    1997-04-01

    Seven college-age healthy men exercised on a wheelchair treadmill to evaluate muscle damage that may occur from wheelchair propulsion. An experimental model in which a participant performs up-hill running in a wheelchair was prepared. Plasma creatinekinase (CK), myoglobin (Mb) and lactatedehydrogenase (LDH) were measured as parameters. Blood samples were taken pre-, immediately after-, 24 h after- and 72 h after the exercise. All of these parameters significantly increased after the exercise, but their time-courses were apparently varied. It is concluded that wheelchair propulsion causes muscle damage in certain situations such as up-hill running.

  5. Jerky Periods: Myoclonus Occurring Solely During Menses

    PubMed Central

    Buijink, Arthur W. G.; Gelauff, Jeannette M.; van der Salm, Sandra M. A.; Tijssen, Marina A. J.; van Rootselaar, Anne-Fleur

    2013-01-01

    Background In this case report, we describe an unusual case of a patient with myoclonus only occurring during menses. Case Report A 41-year-old female, known to have neurological sequelae after a car accident 1 year earlier, presented with myoclonic movements of the right arm and hand only during menses. Brain magnetic resonance imaging is compatible with head trauma. Electromyography shows brief irregular bursts with a duration of about 20 ms. Discussion This appears to be the first description of myoclonus appearing only during menses. We suggest a cortical origin for myoclonus. PMID:23724361

  6. Naturally occurring products in cancer therapy

    PubMed Central

    Rajesh, E.; Sankari, Leena S.; Malathi, L.; Krupaa, Jayasri R.

    2015-01-01

    Natural products have been used for the treatment of various diseases and are becoming an important research area for drug discovery. These products, especially phytochemicals have been extensively studies and have exhibited anti-carcinogenic activities by interfering with the initiation, development and progression of cancer through the modulation of various mechanisms including cellular proliferation, differentiation, apoptosis, angiogenesis, and metastasis. This concept is gaining attention because it is a cost-effective alternative to cancer treatment. In this article, we have discussed some of the naturally occurring products used in cancer treatment. PMID:26015704

  7. Attention turns to naturally occurring methane seepage

    NASA Astrophysics Data System (ADS)

    Kvenvolden, Keith A.; Lorenson, Thomas D.; Reeburgh, William S.

    Methane is the most abundant organic compound in the Earth's atmosphere. As a powerful greenhouse gas, it has implications for global climate change. Sources of methane to the atmosphere are varied. Depending on the source, methane can contain either modern or ancient carbon. Methane exiting from swamps and wetlands contains modern carbon, whereas methane leaking from petroleum reservoirs contains ancient carbon. The total annual source of methane to the atmosphere has been constrained to about 540 teragrams (Tg) per year “Cicerone and Oremland, 1988”. Notably absent from any identified sources is the contribution of geologically sourced methane from naturally occurring seepage.

  8. Do Unexpected Panic Attacks Occur Spontaneously?

    PubMed Central

    Meuret, Alicia E.; Rosenfield, David; Wilhelm, Frank H.; Zhou, Enlu; Conrad, Ansgar; Ritz, Thomas; Roth, Walton T.

    2012-01-01

    Background Spontaneous or unexpected panic attacks, per definition, occur out-of-the blue, in absence of cues or triggers. Accordingly, physiological arousal or instability should occur at the onset of or during the attack, but not preceding it. To test this hypothesisweexaminedif points of significant autonomic changes preceded the onset of spontaneous panic attacks. Methods Forty-three panic disorder patients underwent repeated 24-hour ambulatory monitoring. Thirteen naturally panic attacks were recorded during 1,960 hours of monitoring. Minute-by-minute epochs beginning 60 minutes before, and continuing to 10 minutes after, the onset of individual attacks were examined for respiration, heart rate, and skin conductance level. Measures were controlled for physical activity and vocalization, and compared to time matched control periods within the same person. Results Significant patterns of instability across a numberof autonomic and respiratory variables were detected as early as 47 minutes before panic onset. The final minutes prior to onset were dominated by respiratory changes, with significant decreases in tidal volume followed by abrupt PCO2 increases. Panic attack onset was characterized by heart rate and tidal volume increases and a drop in PCO2. Symptom report was consistent with these changes. Skin conductance levels were generally elevated in the hour before and duringthe attacks. Changes in the matched control periods were largely absent. Conclusions Significant autonomic irregularities preceded the onset of attacks that were reported as abrupt and unexpected. The findings invite reconsideration of the current diagnostic distinction betweenuncuedand cued panic attacks. PMID:21783179

  9. Persulfate activation by naturally occurring trace minerals.

    PubMed

    Teel, Amy L; Ahmad, Mushtaque; Watts, Richard J

    2011-11-30

    The potential for 13 naturally occurring minerals to mediate the decomposition of persulfate and generate a range of reactive oxygen species was investigated to provide fundamental information on activation mechanisms when persulfate is used for in situ chemical oxidation (ISCO). Only four of the minerals (cobaltite, ilmenite, pyrite, and siderite) promoted the decomposition of persulfate more rapidly than persulfate-deionized water control systems. The other nine minerals decomposed persulfate at the same rate or more slowly than the control systems. Mineral-mediated persulfate activation was conducted with the addition of one of three probe compounds to detect the generation of reactive oxygen species: anisole (sulfate+hydroxyl radical), nitrobenzene (hydroxyl radical), and hexachloroethane (reductants and nucleophiles). The reduced mineral pyrite promoted rapid generation of sulfate+hydroxyl radical. However, the remainder of the minerals provided minimal potential for the generation of reactive oxygen species. The results of this research demonstrate that the majority of naturally occurring trace minerals do not activate persulfate to generate reactive oxygen species, and other mechanisms of activation are necessary to promote contaminant destruction in the subsurface during persulfate ISCO.

  10. Dopamine Receptors and Neurodegeneration

    PubMed Central

    Rangel-Barajas, Claudia; Coronel, Israel; Florán, Benjamín

    2015-01-01

    Dopamine (DA) is one of the major neurotransmitters and participates in a number of functions such as motor coordination, emotions, memory, reward mechanism, neuroendocrine regulation etc. DA exerts its effects through five DA receptors that are subdivided in 2 families: D1-like DA receptors (D1 and D5) and the D2-like (D2, D3 and D4). All DA receptors are widely expressed in the central nervous system (CNS) and play an important role in not only in physiological conditions but also pathological scenarios. Abnormalities in the DAergic system and its receptors in the basal ganglia structures are the basis Parkinson’s disease (PD), however DA also participates in other neurodegenerative disorders such as Huntington disease (HD) and multiple sclerosis (MS). Under pathological conditions reorganization of DAergic system has been observed and most of the times, those changes occur as a mechanism of compensation, but in some cases contributes to worsening the alterations. Here we review the changes that occur on DA transmission and DA receptors (DARs) at both levels expression and signals transduction pathways as a result of neurotoxicity, inflammation and in neurodegenerative processes. The better understanding of the role of DA receptors in neuropathological conditions is crucial for development of novel therapeutic approaches to treat alterations related to neurodegenerative diseases. PMID:26425390

  11. Tetrahydroberberine, a pharmacologically active naturally occurring alkaloid.

    PubMed

    Pingali, Subramanya; Donahue, James P; Payton-Stewart, Florastina

    2015-04-01

    Tetrahydroberberine (systematic name: 9,10-dimethoxy-5,8,13,13a-tetrahydro-6H-benzo[g][1,3]benzodioxolo[5,6-a]quinolizine), C20H21NO4, a widely distributed naturally occurring alkaloid, has been crystallized as a racemic mixture about an inversion center. A bent conformation of the molecule is observed, with an angle of 24.72 (5)° between the arene rings at the two ends of the reduced quinolizinium core. The intermolecular hydrogen bonds that play an apparent role in crystal packing are 1,3-benzodioxole -CH2···OCH3 and -OCH3···OCH3 interactions between neighboring molecules.

  12. Does dietary learning occur outside awareness?

    PubMed

    Brunstrom, Jeffrey M

    2004-09-01

    Several forms of dietary learning have been identified in humans. These include flavor-flavor learning, flavor-postingestive learning (including flavor-caffeine learning), and learned satiety. Generally, learning is thought to occur in the absence of contingency (CS-US) or demand awareness. However, a review of the literature suggests that this conclusion may be premature because measures of awareness lack the rigor that is found in studies of other kinds of human learning. If associations do configure outside awareness then this should be regarded as a rare instance of automatic learning. Conversely, if awareness is important, then successful learning may be governed by an individual's beliefs and predilection to attend to stimulus relationships. For researchers of dietary learning this could be critical because it might explain why learning paradigms have a reputation for being unreliable. Since most food preferences are learned, asking questions about awareness can also tell us something fundamental about everyday dietary control.

  13. Do unexpected panic attacks occur spontaneously?

    PubMed

    Meuret, Alicia E; Rosenfield, David; Wilhelm, Frank H; Zhou, Enlu; Conrad, Ansgar; Ritz, Thomas; Roth, Walton T

    2011-11-15

    Spontaneous or unexpected panic attacks, per definition, occur "out of the blue," in the absence of cues or triggers. Accordingly, physiological arousal or instability should occur at the onset of, or during, the attack, but not preceding it. To test this hypothesis, we examined if points of significant autonomic changes preceded the onset of spontaneous panic attacks. Forty-three panic disorder patients underwent repeated 24-hour ambulatory monitoring. Thirteen natural panic attacks were recorded during 1960 hours of monitoring. Minute-by-minute epochs beginning 60 minutes before and continuing to 10 minutes after the onset of individual attacks were examined for respiration, heart rate, and skin conductance level. Measures were controlled for physical activity and vocalization and compared with time matched control periods within the same person. Significant patterns of instability across a number of autonomic and respiratory variables were detected as early as 47 minutes before panic onset. The final minutes before onset were dominated by respiratory changes, with significant decreases in tidal volume followed by abrupt carbon dioxide partial pressure increases. Panic attack onset was characterized by heart rate and tidal volume increases and a drop in carbon dioxide partial pressure. Symptom report was consistent with these changes. Skin conductance levels were generally elevated in the hour before, and during, the attacks. Changes in the matched control periods were largely absent. Significant autonomic irregularities preceded the onset of attacks that were reported as abrupt and unexpected. The findings invite reconsideration of the current diagnostic distinction between uncued and cued panic attacks. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  14. Hibernation in a primate: does sleep occur?

    PubMed Central

    Dausmann, Kathrin H.; Faherty, Sheena L.; Klopfer, Peter; Krystal, Andrew D.; Schopler, Robert; Yoder, Anne D.

    2016-01-01

    During hibernation, critical physiological processes are downregulated and thermogenically induced arousals are presumably needed periodically to fulfil those physiological demands. Among the processes incompatible with a hypome tabolic state is sleep. However, one hibernating primate, the dwarf lemur Cheirogaleus medius, experiences rapid eye movement (REM)-like states during hibernation, whenever passively reaching temperatures above 30°C, as occurs when it hibernates in poorly insulated tree hollows under tropical conditions. Here, we report electroencephalographic (EEG) recordings, temperature data and metabolic rates from two related species (C. crossleyi and C. sibreei), inhabiting high-altitude rainforests and hibernating underground, conditions that mirror, to some extent, those experienced by temperate hibernators. We compared the physiology of hibernation and spontaneous arousals in these animals to C. medius, as well as the much more distantly related non-primate hibernators, such as Arctic, golden-mantled and European ground squirrels. We observed a number of commonalities with non-primate temperate hibernators including: (i) monotonous ultra-low voltage EEG during torpor bouts in these relatively cold-weather hibernators, (ii) the absence of sleep during torpor bouts, (iii) the occurrence of spontaneous arousals out of torpor, during which sleep regularly occurred, (iv) relatively high early EEG non-REM during the arousal, and (v) a gradual transition to the torpid EEG state from non-REM sleep. Unlike C. medius, our study species did not display sleep-like states during torpor bouts, but instead exclusively exhibited them during arousals. During these short euthermic periods, non-REM as well as REM sleep-like stages were observed. Differences observed between these two species and their close relative, C. medius, for which data have been published, presumably reflect differences in hibernaculum temperature. PMID:27853604

  15. Introduction to naturally occurring radioactive material

    SciTech Connect

    Egidi, P.

    1997-08-01

    Naturally occurring radioactive material (NORM) is everywhere; we are exposed to it every day. It is found in our bodies, the food we eat, the places where we live and work, and in products we use. We are also bathed in a sea of natural radiation coming from the sun and deep space. Living systems have adapted to these levels of radiation and radioactivity. But some industrial practices involving natural resources concentrate these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Other activities, such as flying at high altitudes, expose us to elevated levels of NORM. This session will concentrate on diffuse sources of technologically-enhanced (TE) NORM, which are generally large-volume, low-activity waste streams produced by industries such as mineral mining, ore benefication, production of phosphate Fertilizers, water treatment and purification, and oil and gas production. The majority of radionuclides in TENORM are found in the uranium and thorium decay chains. Radium and its subsequent decay products (radon) are the principal radionuclides used in characterizing the redistribution of TENORM in the environment by human activity. We will briefly review other radionuclides occurring in nature (potassium and rubidium) that contribute primarily to background doses. TENORM is found in many waste streams; for example, scrap metal, sludges, slags, fluids, and is being discovered in industries traditionally not thought of as affected by radionuclide contamination. Not only the forms and volumes, but the levels of radioactivity in TENORM vary. Current discussions about the validity of the linear no dose threshold theory are central to the TENORM issue. TENORM is not regulated by the Atomic Energy Act or other Federal regulations. Control and regulation of TENORM is not consistent from industry to industry nor from state to state. Proposed regulations are moving from concentration-based standards to dose

  16. Medicinal significance of naturally occurring cyclotetrapeptides.

    PubMed

    Abdalla, Muna Ali

    2016-10-01

    Bioactive natural products are serendipitous drug candidates, which stimulate synthetic approaches for improving and supporting drug discovery and development. Therefore, the search for bioactive metabolites from different natural sources continues to play an important role in fashioning new medicinal agents. Several cyclic peptides were produced by organisms, such as β-defensins, gramicidin S, and tyrocidine A, and exhibited a wide range of bioactivities, such as antiviral activity against HIV-1, influenza A viruses, or antibacterial activity. Cyclic tetrapeptides are a class of natural products that were found to have a broad range of biological activities, promising pharmacokinetic properties, as well as interesting conformational dynamics and ability of slow inter-conversion to several different structures. Cyclooligopeptides, particularly medium ring-sized peptides, were obtained from marine microorganisms and exhibited a wide range of pharmacological properties, including antimicrobial and anti-dinoflagellate activities, cytotoxicity, and inhibitory activity against enzyme sortase B. Most of the naturally occurring cyclotetrapeptides are obtained from fungi. Some natural cyclic tetrapeptides were found to inhibit histone deacetylase (HDAC), which regulate the expression of genes. These compounds are very useful as cancer therapeutics. Various analogues of the natural cyclotetrapeptides were successfully synthesized to find novel lead compounds for pharmacological and biotechnological applications. Therefore, in this review, previously reported novel natural cyclotetrapeptides are briefly discussed, along with their important biological activities as drug candidates, together with their promising therapeutic properties. Moreover, their future perspective in drug discovery as potential therapeutic agents will be determined.

  17. Epigenetic Mechanisms in Commonly Occurring Cancers

    PubMed Central

    2012-01-01

    Cancer is a collection of very complex diseases that share many traits while differing in many ways as well. This makes a universal cure difficult to attain, and it highlights the importance of understanding each type of cancer at a molecular level. Although many strides have been made in identifying the genetic causes for some cancers, we now understand that simple changes in the primary DNA sequence cannot explain the many steps that are necessary to turn a normal cell into a rouge cancer cell. In recent years, some research has shifted to focusing on detailing epigenetic contributions to the development and progression of cancer. These changes occur apart from primary genomic sequences and include DNA methylation, histone modifications, and miRNA expression. Since these epigenetic modifications are reversible, drugs targeting epigenetic changes are becoming more common in clinical settings. Daily discoveries elucidating these complex epigenetic processes are leading to advances in the field of cancer research. These advances, however, come at a rapid and often overwhelming pace. This review specifically summarizes the main epigenetic mechanisms currently documented in solid tumors common in the United States and Europe. PMID:22519822

  18. Does Shear Thickening Occur in Semisolid Metals?

    NASA Astrophysics Data System (ADS)

    Atkinson, Helen V.; Favier, Veronique

    2016-04-01

    In the various forms of semisolid processing such as thixoforming and thixoforging, the entry into the die occurs in a fraction of a second so it is the transient rheological behavior which governs the initial stages of flow. In experiments in the literature, this rheological behavior is probed through applying rapid transitions in shear rate under isothermal conditions. There is contradictory evidence as to whether the behavior during these transitions is shear thinning or shear thickening, although it is clear that once in the die the material is thinning. Here the data in the literature are reanalyzed to obtain a rationalization of the contradictions which has not previously been available. It is argued that if a suspension is initially in a disagglomerated state ( i.e., one which is initially sheared), the instantaneous behavior with a jump-up in shear rate is shear thickening (even if the long-term steady-state behavior is shear thinning) provided the fraction solid is greater than about 0.36 and the final shear rate at the end of the jump is greater than about 100 s-1. If the jump-up in shear rate is made from rest then yield masks the shear thickening.

  19. Naturally occurring contamination in the Mancos Shale.

    PubMed

    Morrison, Stan J; Goodknight, Craig S; Tigar, Aaron D; Bush, Richard P; Gil, April

    2012-02-07

    Some uranium mill tailings disposal cells were constructed on dark-gray shale of the Upper Cretaceous Mancos Shale. Shale of this formation contains contaminants similar to those in mill tailings. To establish the contributions derived from the Mancos, we sampled 51 locations in Colorado, New Mexico, and Utah. Many of the groundwater samples were saline with nitrate, selenium, and uranium concentrations commonly exceeding 250, 000, 1000, and 200 μg/L, respectively. Higher concentrations were limited to groundwater associated with shale beds, but were not correlated with geographic area, stratigraphic position, or source of water. The elevated concentrations suggest that naturally occurring contamination should be considered when evaluating groundwater cleanup levels. At several locations, seep water was yellow or red, caused in part by dissolved organic carbon concentrations up to 280 mg/L. Most seeps had (234)U to (238)U activity ratios greater than 2, indicating preferential leaching of (234)U. Seeps were slightly enriched in (18)O relative to the meteoric water line, indicating limited evaporation. Conceptually, major ion chemical reactions are dominated by calcite dissolution following proton release from pyrite oxidation and subsequent exchange by calcium for sodium residing on clay mineral exchange sites. Contaminants are likely released from organic matter and mineral surfaces during weathering.

  20. Differential dormancy of co-occurring copepods

    NASA Astrophysics Data System (ADS)

    Ohman, Mark D.; Drits, Aleksandr V.; Elizabeth Clarke, M.; Plourde, Stéphane

    1998-08-01

    Four species of planktonic calanoid copepods that co-occur in the California Current System ( Eucalanus californicus Johnson, Rhincalanus nasutus Giesbrecht, Calanus pacificus californicus Brodsky, and Metridia pacifica Brodsky) were investigated for evidence of seasonal dormancy in the San Diego Trough. Indices used to differentiate actively growing from dormant animals included developmental stage structure and vertical distribution; activity of aerobic metabolic enzymes (Citrate Synthase and the Electron Transfer System complex); investment in depot lipids (wax esters and triacylglycerols); in situ grazing activity from gut fluorescence; and egg production rates in simulated in situ conditions. None of the 4 species exhibited a canonical calanoid pattern of winter dormancy - i.e., synchronous developmental arrest as copepodid stage V, descent into deep waters, reduced metabolism, and lack of winter reproduction. Instead, Calanus pacificus californicus has a biphasic life history in this region, with an actively reproducing segment of the population in surface waters overlying a deep dormant segment in winter. Eucalanus californicus is dormant as both adult females and copepodid V's, although winter females respond relatively rapidly to elevated food and temperature conditions; they begin feeding and producing eggs within 2-3 days. Rhincalanus nasutus appears to enter dormancy as adult females, although the evidence is equivocal. Metridia pacifica shows no evidence of dormancy, with sustained active feeding, diel vertical migration behavior, and elevated activity of metabolic enzymes in December as well as in June. The four species also differ markedly in water content, classes of storage lipids, and specific activity of Citrate Synthase. These results suggest that copepod dormancy traits and structural composition reflect diverse adaptations to regional environmental conditions rather than a uniform, canonical series of traits that remain invariant among taxa

  1. Sundew adhesive: a naturally occurring hydrogel

    PubMed Central

    Huang, Yujian; Wang, Yongzhong; Sun, Leming; Agrawal, Richa; Zhang, Mingjun

    2015-01-01

    Bioadhesives have drawn increasing interest in recent years, owing to their eco-friendly, biocompatible and biodegradable nature. As a typical bioadhesive, sticky exudate observed on the stalked glands of sundew plants aids in the capture of insects and this viscoelastic adhesive has triggered extensive interests in revealing the implied adhesion mechanisms. Despite the significant progress that has been made, the structural traits of the sundew adhesive, especially the morphological characteristics in nanoscale, which may give rise to the viscous and elastic properties of this mucilage, remain unclear. Here, we show that the sundew adhesive is a naturally occurring hydrogel, consisting of nano-network architectures assembled with polysaccharides. The assembly process of the polysaccharides in this hydrogel is proposed to be driven by electrostatic interactions mediated with divalent cations. Negatively charged nanoparticles, with an average diameter of 231.9 ± 14.8 nm, are also obtained from this hydrogel and these nanoparticles are presumed to exert vital roles in the assembly of the nano-networks. Further characterization via atomic force microscopy indicates that the stretching deformation of the sundew adhesive is associated with the flexibility of its fibrous architectures. It is also observed that the adhesion strength of the sundew adhesive is susceptible to low temperatures. Both elasticity and adhesion strength of the sundew adhesive reduce in response to lowering the ambient temperature. The feasibility of applying sundew adhesive for tissue engineering is subsequently explored in this study. Results show that the fibrous scaffolds obtained from sundew adhesive are capable of increasing the adhesion of multiple types of cells, including fibroblast cells and smooth muscle cells, a property that results from the enhanced adsorption of serum proteins. In addition, in light of the weak cytotoxic activity exhibited by these scaffolds towards a variety of

  2. Information Needs While A Disaster Is Occurring

    NASA Astrophysics Data System (ADS)

    Perry, S. C.

    2010-12-01

    that rainfall intensity at their homes might be less than the intensity up in the mountains where the debris flows would start. Nor did they know that debris flows travel too quickly to be outrun. These and many other examples indicate need for social and natural scientists to increase awareness of what to expect when the disaster strikes. This information must be solidly understood before the event occurs - while a disaster is unfolding there are no teachable moments. Case studies indicate that even those who come into a disaster well educated about the phenomenon can struggle to apply what they know when the real situation is at hand. In addition, psychological studies confirm diminished ability to comprehend information at times of stress.

  3. Adenosine receptor neurobiology: overview.

    PubMed

    Chen, Jiang-Fan; Lee, Chien-fei; Chern, Yijuang

    2014-01-01

    Adenosine is a naturally occurring nucleoside that is distributed ubiquitously throughout the body as a metabolic intermediary. In the brain, adenosine functions as an important upstream neuromodulator of a broad spectrum of neurotransmitters, receptors, and signaling pathways. By acting through four G-protein-coupled receptors, adenosine contributes critically to homeostasis and neuromodulatory control of a variety of normal and abnormal brain functions, ranging from synaptic plasticity, to cognition, to sleep, to motor activity to neuroinflammation, and cell death. This review begun with an overview of the gene and genome structure and the expression pattern of adenosine receptors (ARs). We feature several new developments over the past decade in our understanding of AR functions in the brain, with special focus on the identification and characterization of canonical and noncanonical signaling pathways of ARs. We provide an update on functional insights from complementary genetic-knockout and pharmacological studies on the AR control of various brain functions. We also highlight several novel and recent developments of AR neurobiology, including (i) recent breakthrough in high resolution of three-dimension structure of adenosine A2A receptors (A2ARs) in several functional status, (ii) receptor-receptor heterodimerization, (iii) AR function in glial cells, and (iv) the druggability of AR. We concluded the review with the contention that these new developments extend and strengthen the support for A1 and A2ARs in brain as therapeutic targets for neurologic and psychiatric diseases. © 2014 Elsevier Inc. All rights reserved.

  4. Kinematics and mass modelling of M33: Hα observations

    NASA Astrophysics Data System (ADS)

    Kam, Z. S.; Carignan, C.; Chemin, L.; Amram, P.; Epinat, B.

    2015-06-01

    As part of a long-term project to revisit the kinematics and dynamics of the large disc galaxies of the Local Group, we present the first deep, wide-field (˜42 arcmin × 56 arcmin) 3D-spectroscopic survey of the ionized gas disc of Messier 33. Fabry-Perot interferometry has been used to map its Hα distribution and kinematics at unprecedented angular resolution (≲3 arcsec) and resolving power (˜12 600), with the 1.6 m telescope at the Observatoire du Mont Mégantic. The ionized gas distribution follows a complex, large-scale spiral structure, unsurprisingly coincident with the already-known spiral structures of the neutral and molecular gas discs. The kinematical analysis of the velocity field shows that the rotation centre of the Hα disc is distant from the photometric centre by ˜168 pc (sky-projected distance) and that the kinematical major-axis position angle and disc inclination are in excellent agreement with photometric values. The Hα rotation curve agrees very well with the H I rotation curves for 0 < R < 6.5 kpc, but the Hα velocities are 10-20 km s-1 higher for R > 6.5 kpc. The reason for this discrepancy is not well understood. The velocity dispersion profile is relatively flat around 16 km s-1, which is at the low end of velocity dispersions of nearby star-forming galactic discs. A strong relation is also found between the Hα velocity dispersion and the Hα intensity. Mass models were obtained using the Hα rotation curve but, as expected, the dark matter halo's parameters are not very well constrained since the optical rotation curve only extends out to 8 kpc.

  5. Memory impairment due to fipronil pesticide exposure occurs at the GABAA receptor level, in rats.

    PubMed

    Godinho, Antonio Francisco; de Oliveira Souza, Ana Carolina; Carvalho, Caio Cristóvão; Horta, Daniel França; De Fraia, Daniel; Anselmo, Fabio; Chaguri, João Leandro; Faria, Caique Aparecido

    2016-10-15

    Fipronil (F) a pesticide considered of second generation cause various toxic effects in target and non-target organisms including humans in which provoke neurotoxicity, having the antagonism of gamma-amino butyric acid (GABA) as their main mechanism for toxic action. GABAergic system has been involved in processes related to the memory formation and consolidation. The present work studied the importance of GABA to the mechanisms involved in the very early development of fipronil-induced memory impairment in rats. Memory behavior was assessed using new object recognition task (ORT) and eight radial arm maze task (8-RAM) to study effects on cognitive and spatial memory. Locomotor behavior was assessed using open field task (OF). The dose of fipronil utilized was studied through a pilot experiment. The GABA antagonist picrotoxin (P) was used to enhance fipronil effects on GABAergic system. Fipronil or picrotoxin decrease memory studied in ORT and 8-RAM tasks. Additionally, F and P co-exposure enhanced effects on memory compared to controls, F, and P, suggesting strongly a GABAergic effect. Weight gain modulation and fipronil in blood were utilized as animal's intoxication indicators. In conclusion, here we report that second-generation pesticides, such as fipronil, can have toxic interactions with the CNS of mammals and lead to memory impairment by modulating the GABAergic system. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Antiphospholipid reactivity against cardiolipin metabolites occurring during endothelial cell apoptosis

    PubMed Central

    Alessandri, Cristiano; Sorice, Maurizio; Bombardieri, Michele; Conigliaro, Paola; Longo, Agostina; Garofalo, Tina; Manganelli, Valeria; Conti, Fabrizio; Esposti, Mauro Degli; Valesini, Guido

    2006-01-01

    We have recently shown that cardiolipin (CL) and its metabolites move from mitochondria to other cellular membranes during death receptor-mediated apoptosis. In this study, we investigate the immunoreactivity to CL derivatives occurring during endothelial apoptosis in patients with antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE). We compared the serum immunoreactivity to CL with that of its derivatives monolysocardiolipin (MCL), dilysocardiolipin (DCL), and hydrocardiolipin (HCL) by means of both enzyme-linked immunosorbent assay and thin-layer chromatography (TLC) immunostaining. In addition, we investigated the composition of phospholipid extracts from the plasma membrane of apoptotic endothelial cells and the binding of patients' sera to the surface of the same cells by using high-performance TLC and immunofluorescence analysis. The average reactivity to MCL was comparable with that of CL and significantly higher than that for DCL and HCL in patients studied, both in the presence or in the absence of beta2-glycoprotein I. Of relevance for the pathogenic role of these autoantibodies, immunoglobulin G from patients' sera showed an increased focal reactivity with the plasma membrane of endothelial cells undergoing apoptosis. Interestingly, the phospholipid analysis of these light membrane fractions showed an accumulation of both CL and MCL. Our results demonstrated that a critical number of acyl chains in CL derivatives is important for the binding of antiphospholipid antibodies and that MCL is an antigenic target with immunoreactivity comparable with CL in APS and SLE. Our finding also suggests a link between apoptotic perturbation of CL metabolism and the production of these antibodies. PMID:17150088

  7. Iron deficiency occurs frequently in children with cystic fibrosis.

    PubMed

    Uijterschout, Lieke; Nuijsink, Marianne; Hendriks, Daniëlle; Vos, Rimke; Brus, Frank

    2014-05-01

    In adult CF patients iron deficiency (ID) is common and primarily functional due to chronic inflammation. No recent data are available on the cause of ID and iron deficiency anemia (IDA) in children with CF. Over the last decades onset of inflammation and pulmonary disease in children with CF is delayed by improved nutritional status. We questioned whether ID occurs in the same extent among children with CF as in adult CF patients. We therefore conducted a study to investigate the iron status of children with CF and to determine whether ID and IDA are associated with dietary iron intake, lung disease severity and Pseudomonas aeruginosa (PA) infection. Clinical charts of 53 children with CF aged 0-16 were reviewed. Follow-up varied from 1 to 14 years with 343 annual observations in total. Thirty-two children (60.4%) were iron deficient in at least 1 year and ID was present in 84 of 343 observations (24.5%). In 2011 ID was present in 9 children (17.0%). Ten children (18.9%) were anemic in at least 1 year and anemia was present in 13 of 328 observations (4.0%). IDA was present in at least 1 year in 6 children (11.3%). Ferritin (Fer) was positively associated with age. Higher Fer values found in older children represent an increased state of inflammation, rather than an improved iron status, and might increase the relative contribution of functional ID. This study shows that ID is common in relatively healthy, well-nourished children with CF. The mechanism of ID in children with CF is currently unknown. A prospective study using both soluble transferrin receptor and Fer as indicators for ID will provide more insight in the incidence and causes of ID in children with CF.

  8. Seasonal immunoregulation in a naturally-occurring vertebrate.

    PubMed

    Brown, Martha; Hablützel, Pascal; Friberg, Ida M; Thomason, Anna G; Stewart, Alexander; Pachebat, Justin A; Jackson, Joseph A

    2016-05-18

    Fishes show seasonal patterns of immunity, but such phenomena are imperfectly understood in vertebrates generally, even in humans and mice. As these seasonal patterns may link to infectious disease risk and individual condition, the nature of their control has real practical implications. Here we characterize seasonal dynamics in the expression of conserved vertebrate immunity genes in a naturally-occurring piscine model, the three-spined stickleback. We made genome-wide measurements (RNAseq) of whole-fish mRNA pools (n = 36) at the end of summer and winter in contrasting habitats (riverine and lacustrine) and focussed on common trends to filter habitat-specific from overarching temporal responses. We corroborated this analysis with targeted year-round whole-fish gene expression (Q-PCR) studies in a different year (n = 478). We also considered seasonal tissue-specific expression (6 tissues) (n = 15) at a third contrasting (euryhaline) locality by Q-PCR, further validating the generality of the patterns seen in whole fish analyses. Extremes of season were the dominant predictor of immune expression (compared to sex, ontogeny or habitat). Signatures of adaptive immunity were elevated in late summer. In contrast, late winter was accompanied by signatures of innate immunity (including IL-1 signalling and non-classical complement activity) and modulated toll-like receptor signalling. Negative regulators of T-cell activity were prominent amongst winter-biased genes, suggesting that adaptive immunity is actively down-regulated during winter rather than passively tracking ambient temperature. Network analyses identified a small set of immune genes that might lie close to a regulatory axis. These genes acted as hubs linking summer-biased adaptive pathways, winter-biased innate pathways and other organismal processes, including growth, metabolic dynamics and responses to stress and temperature. Seasonal change was most pronounced in the gill, which contains a

  9. A comparison of substorms occurring during magnetic storms with those occurring during quiet times

    NASA Astrophysics Data System (ADS)

    McPherron, R. L.; Hsu, T.-S.

    2002-09-01

    It has been suggested that there may be a fundamental difference between substorms that occur during magnetic storms and those that occur at other times. [1996] presented evidence that there is no obvious change in lobe field in "quiet time" substorms but that "storm time" substorms exhibit the classic pattern of storage and release of lobe field energy. This result led them to speculate that the former are caused by current sheet disruption, while the latter are caused by reconnection of lobe flux. In this paper we examine their hypothesis with a much larger data set using definitions of the two types of substorms similar to theirs, as well as additional more restrictive definitions of these classes of events. Our results show that the only differences between the various classes are the absolute value of the lobe field and the size of the changes. When the data are normalized to unit field amplitude, we find that the percent change during storm time and non-storm time substorms is nearly the same. The above conclusions are demonstrated with superposed epoch analysis of lobe field (Bt and Bz) for four classes of substorms: active times (Dst < -50 nT, mostly recovery phase), main phase substorms, non-storm times (Dst > -25 nT), and quiet time substorms (no evidence of storm in Dst). Epoch zero for the analysis was taken as the main substorm onset (Pi2 onset closest to sharp break in AL index). Our results suggest that there is no qualitative distinction between the various classes of substorms, and so they are all likely to be caused by the same mechanism.

  10. Human presynaptic receptors.

    PubMed

    Schlicker, Eberhard; Feuerstein, Thomas

    2017-04-01

    Presynaptic receptors are sites at which transmitters, locally formed mediators or hormones inhibit or facilitate the release of a given transmitter from its axon terminals. The interest in the identification of presynaptic receptors has faded in recent years and it may therefore be justified to give an overview of their occurrence in the autonomic and central nervous system; this review will focus on presynaptic receptors in human tissues. Autoreceptors are presynaptic receptors at which a given transmitter restrains its further release, though in some instances may also increase its release. Inhibitory autoreceptors represent a typical example of a negative feedback; they are tonically activated by the respective endogenous transmitter and/or are constitutively active. Autoreceptors also play a role under pathophysiological conditions, e.g. by limiting the massive noradrenaline release occurring during congestive heart failure. They can be used for therapeutic purposes; e.g., the α2-adrenoceptor antagonist mirtazapine is used as an antidepressant and the inverse histamine H3 receptor agonist pitolisant has been marketed as a new drug for the treatment of narcolepsy in 2016. Heteroreceptors are presynaptic receptors at which transmitters from adjacent neurons, locally formed mediators (e.g. endocannabinoids) or hormones (e.g. adrenaline) can inhibit or facilitate transmitter release; they may be subject to an endogenous tone. The constipating effect of the sympathetic nervous system or of the antihypertensive drug clonidine is related to the activation of inhibitory α2-adrenoceptors on postganglionic parasympathetic neurons. Part of the stimulating effect of adrenaline on the sympathetic nervous system during stress is related to its facilitatory effect on noradrenaline release via β2-adrenoceptors.

  11. Direct imaging of lateral movements of AMPA receptors inside synapses

    PubMed Central

    Tardin, Catherine; Cognet, Laurent; Bats, Cécile; Lounis, Brahim; Choquet, Daniel

    2003-01-01

    Trafficking of AMPA receptors in and out of synapses is crucial for synaptic plasticity. Previous studies have focused on the role of endo/exocytosis processes or that of lateral diffusion of extra-synaptic receptors. We have now directly imaged AMPAR movements inside and outside synapses of live neurons using single- molecule fluorescence microscopy. Inside individual synapses, we found immobile and mobile receptors, which display restricted diffusion. Extra-synaptic receptors display free diffusion. Receptors could also exchange between these membrane compartments through lateral diffusion. Glutamate application increased both receptor mobility inside synapses and the fraction of mobile receptors present in a juxtasynaptic region. Block of inhibitory transmission to favor excitatory synaptic activity induced a transient increase in the fraction of mobile receptors and a decrease in the proportion of juxtasynaptic receptors. Altogether, our data show that rapid exchange of receptors between a synaptic and extra-synaptic localization occurs through regulation of receptor diffusion inside synapses. PMID:12970178

  12. Estrogen receptors in breast carcinoma.

    PubMed

    Huaman, A

    1979-11-01

    On the basis of estrogen receptor assays, breast carcinomas are presently classified as estrogen-dependent tumors, which respond to endocrine therapy, and autonomous tumors, for which endocrine therapy is useless. This paper presents a short review of the biochemical principles of estrogen dependence, the procedures used to determine estrogen receptors, and the clinical applications of the findings of these assay procedures. Biobhemically, the estroogen dependence of normal breast cells is explained as a biochemical reaction occurring between the circulating estradiol and the breast cell, which occurs in 3 steps: 1) circulating estradiol penetrates the cellular membrane by passive diffusion, followed by 2) combining of estradiol with the estrogen-binding protein (estrophilin) and formation of an estrogen receptor complex which undergoes activation and translocation into the nucleus, to result in 3) the activated steroid receptor which combines with the nuclear charomatin and stimulates ribonucleic acid synthesis for the formation of estradiol binding proteins or estradiol receptors. The cytosol method of Wittliff et al. is described in brief and entails radioactive competitive analysis; the other available laboratory procedure is immunofluorescence of tumor sections. Quantification of estrogen receptor content can be used clinically to decide on ablative endocrine therapy, to determine the effectiveness of anti-estrogen administration, to determine the primary site of metastatic carcinoma, and as a screenng device.

  13. Opioid Receptors.

    PubMed

    Stein, Christoph

    2016-01-01

    Opioids are the oldest and most potent drugs for the treatment of severe pain. Their clinical application is undisputed in acute (e.g., postoperative) and cancer pain, but their long-term use in chronic pain has met increasing scrutiny. This article reviews mechanisms underlying opioid analgesia and other opioid actions. It discusses the structure, function, and plasticity of opioid receptors; the central and peripheral sites of analgesic actions and side effects; endogenous and exogenous opioid receptor ligands; and conventional and novel opioid compounds. Challenging clinical situations, such as the tension between chronic pain and addiction, are also illustrated.

  14. The measurement of serum transferrin receptor.

    PubMed

    Cook, J D

    1999-10-01

    The concentration of the soluble fragment of transferrin receptor in serum is an important new hematological parameter. Clinical and laboratory studies have shown that this serum form of the receptor reflects the total body mass of cellular transferrin receptor, 80% of which is contained in the erythroid marrow. The two disorders that result in an elevation in the serum transferrin receptor are anemias associated with enhanced erythropoiesis and tissue iron deficiency. The concentration of soluble transferrin receptor provides a useful quantitative measure of the erythroid marrow mass and thereby assists clinically in categorizing the type of anemia. The most important clinical use of the serum transferrin receptor is in determining the cause of iron deficient erythropoiesis (that is, identifying iron deficiency anemia whether it occurs alone or in the presence of the anemia of chronic disease). Present evidence supports the routine use of the serum transferrin receptor in the clinical evaluation of anemic patients.

  15. Oxytocin receptors and parturition. I. Control of oxytocin receptor concentration in the rat myometrium at term.

    PubMed

    Alexandrova, M; Soloff, M S

    1980-03-01

    Rat myometrium exhibited a marked rise in the concentration of oxytocin (OT) receptors during parturition. The elevation began several hours before labor, was maximal during labor, and declined several hours later. In the perinatal period, the change in OT receptor concentration was proportional to the ratio of plasma estradiol to progesterone levels. Several hours before the increase in OT receptor concentration, there was a proportional increase in estrogen receptor concentration in both the cytosol and nuclear fractions of the myometrium. In view of the known action of estrogens in increasing the concentration of OT receptors in rat uterus, we propose that the following sequence of events occurs in the initiation of labor in the rat. The decline in serum progesterone permits estradiol to stimulate the synthesis of estrogen receptors in the myometrium. This increased concentration of estrogen receptors and their occupancy by estradiol stimulates the appearance of more OT receptors, which then trigger labor by interacting with circulating OT.

  16. A Naturally-Occurring Transcript Variant of MARCO Reveals the SRCR Domain is Critical for Function

    PubMed Central

    Novakowski, Kyle E.; Huynh, Angela; Han, SeongJun; Dorrington, Michael G.; Yin, Charles; Tu, Zhongyuan; Pelka, Peter; Whyte, Peter; Guarné, Alba; Sakamoto, Kaori; Bowdish, Dawn M.E.

    2016-01-01

    Macrophage receptor with collagenous structure (MARCO) is a Class A Scavenger Receptor (cA-SR) that recognizes and phagocytoses of a wide variety of pathogens. Most cA-SRs that contain a C-terminal Scavenger Receptor Cysteine Rich (SRCR) domain use the proximal collagenous domain to bind ligands. In contrast, for the role of the SRCR domain of MARCO in phagocytosis, adhesion and pro-inflammatory signalling is less clear. The discovery of a naturally-occurring transcript variant lacking the SRCR domain, MARCOII, provided the opportunity to study the role of the SRCR domain of MARCO. We tested whether the SRCR domain is required for ligand binding, promoting downstream signalling, and enhancing cellular adhesion. Unlike cells expressing full-length MARCO, ligand binding was abolished in MARCOII-expressing cells. Furthermore, co-expression of MARCO and MARCOII impaired phagocytic function, indicating that MARCOII acts as a dominant negative variant. Unlike MARCO, expression of MARCOII did not enhance Toll-Like Receptor 2 (TLR2)-mediated pro-inflammatory signalling in response to bacterial stimulation. MARCO-expressing cells were more adherent and exhibited a dendritic-like phenotype, while MARCOII-expressing cells were less adherent and did not exhibit changes in morphology. These data suggest the SRCR domain of MARCO is the key domain in modulating ligand binding, enhancing downstream pro-inflammatory signalling, and MARCO-mediated cellular adhesion. PMID:26888252

  17. Causes and Outcomes of Pediatric Injuries Occurring at School.

    ERIC Educational Resources Information Center

    Di Scala, Carla; Gallagher, Susan Scavo; Schneps, Sue E.

    1997-01-01

    Used the National Pediatric Trauma Registry, which collects data on child injuries requiring hospitalization, to examine causes and outcomes of injuries occurring at school. Analysis of 1,558 cases indicated that most injuries were unintentional and occurred among students age 10-14 years. Nearly half occurred in recreational areas. Falls and…

  18. Causes and Outcomes of Pediatric Injuries Occurring at School.

    ERIC Educational Resources Information Center

    Di Scala, Carla; Gallagher, Susan Scavo; Schneps, Sue E.

    1997-01-01

    Used the National Pediatric Trauma Registry, which collects data on child injuries requiring hospitalization, to examine causes and outcomes of injuries occurring at school. Analysis of 1,558 cases indicated that most injuries were unintentional and occurred among students age 10-14 years. Nearly half occurred in recreational areas. Falls and…

  19. Cytokine receptors and hematopoietic differentiation.

    PubMed

    Robb, L

    2007-10-15

    Colony-stimulating factors and other cytokines signal via their cognate receptors to regulate hematopoiesis. In many developmental systems, inductive signalling determines cell fate and, by analogy with this, it has been postulated that cytokines, signalling via their cognate receptors, may play an instructive role in lineage specification in hematopoiesis. An alternative to this instructive hypothesis is the stochastic or permissive hypothesis. The latter proposes that commitment to a particular hematopoietic lineage is an event that occurs independently of extrinsic signals. It predicts that the role of cytokines is to provide nonspecific survival and proliferation signals. In this review, we look at the role of cytokine receptor signalling in hematopoiesis and consider the evidence for both hypotheses. Data from experiments that genetically manipulate receptor gene expression in vitro or in vivo are reviewed. Experiments in which cytokine receptors were installed in multipotential cells showed that, in some cases, stimulation with the cognate ligand could lead to alterations in lineage output. The creation of genetically manipulated mouse strains demonstrated that cytokine receptors are required for expansion and survival of single lineages but did not reveal a role in lineage commitment. We conclude that hematopoietic differentiation involves mainly stochastic events, but that cytokine receptors also have some instructive role.

  20. Structural determinants of sigma receptor affinity

    SciTech Connect

    Largent, B.L.; Wikstroem, H.G.; Gundlach, A.L.; Snyder, S.H.

    1987-12-01

    The structural determinants of sigma receptor affinity have been evaluated by examining a wide range of compounds related to opioids, neuroleptics, and phenylpiperidine dopaminergic structures for affinity at sigma receptor-binding sites labeled with (+)-(/sup 3/H)3-PPP. Among opioid compounds, requirements for sigma receptor affinity differ strikingly from the determinants of affinity for conventional opiate receptors. Sigma sites display reverse stereoselectivity to classical opiate receptors. Multi-ringed opiate-related compounds such as morphine and naloxone have negligible affinity for sigma sites, with the highest sigma receptor affinity apparent for benzomorphans which lack the C ring of opioids. Highest affinity among opioids and other compounds occurs with more lipophilic N-substituents. This feature is particularly striking among the 3-PPP derivatives as well as the opioids. The butyrophenone haloperidol is the most potent drug at sigma receptors we have detected. Among the series of butyrophenones, receptor affinity is primarily associated with the 4-phenylpiperidine moiety. Conformational calculations for various compounds indicate a fairly wide range of tolerance for distances between the aromatic ring and the amine nitrogen, which may account for the potency at sigma receptors of structures of considerable diversity. Among the wide range of structures that bind to sigma receptor-binding sites, the common pharmacophore associated with high receptor affinity is a phenylpiperidine with a lipophilic N-substituent.

  1. Signal transduction activated by cannabinoid receptors.

    PubMed

    Díaz-Laviada, Inés; Ruiz-Llorente, Lidia

    2005-07-01

    Since the discovery that cannabinoids exert biological actions through binding to specific receptors, signal mechanisms triggered by these receptors have been focus of extensive study. This review summarizes the current knowledge of the signalling events produced by cannabinoids from membrane receptors to downstream regulators. Two types of cannabinoid receptors have been identified to date: CB(1) and CB(2) both belonging to the heptahelichoidal receptor family but with different tissue distribution and signalling mechanisms. Coupling to inhibitory guanine nucleotide-binding protein and thus inhibition of adenylyl cyclase has been observed in both receptors but other signal transduction pathways that are regulated or not by these G proteins are differently activated upon ligand-receptor binding including ion channels, sphingomyelin hydrolysis, ceramide generation, phospholipases activation and downstream targets as MAP kinase cascade, PI3K, FAK or NOS regulation. Cannabinoids may also act independently of CB(1)or CB(2) receptors. The existence of new unidentified putative cannabinoid receptors has been claimed by many investigators. Endocannabinoids activate vanilloid TRPV1 receptors that may mediate some of the cannabinoid effects. Other actions of cannabinoids can occur through non-receptor-mediated mechanisms.

  2. Dopamine receptor oligomerization visualized in living cells.

    PubMed

    O'Dowd, Brian F; Ji, Xiaodong; Alijaniaram, Mohammad; Rajaram, Ryan D; Kong, Michael M C; Rashid, Asim; Nguyen, Tuan; George, Susan R

    2005-11-04

    G protein-coupled receptors occur as dimers within arrays of oligomers. We visualized ensembles of dopamine receptor oligomers in living cells and evaluated the contributions of receptor conformation to the dynamics of oligomer association and dissociation, using a strategy of trafficking a receptor to another cellular compartment. We incorporated a nuclear localization sequence into the D1 dopamine receptor, which translocated from the cell surface to the nucleus. Receptor inverse agonists blocked this translocation, retaining the modified receptor, D1-nuclear localization signal (NLS), at the cell surface. D1 co-translocated with D1-NLS to the nucleus, indicating formation of homooligomers. (+)-Butaclamol retained both receptors at the cell surface, and removal of the drug allowed translocation of both receptors to the nucleus. Agonist-nonbinding D1(S198A/S199A)-NLS, containing two substituted serine residues in transmembrane 5 also oligomerized with D1, and both were retained on the cell surface by (+)-butaclamol. Drug removal disrupted these oligomerized receptors so that D1 remained at the cell surface while D1(S198A/S199A)-NLS trafficked to the nucleus. Thus, receptor conformational differences permitted oligomer disruption and showed that ligand-binding pocket occupancy by the inverse agonist induced a conformational change. We demonstrated robust heterooligomerization between the D2 dopamine receptor and the D1 receptor. The heterooligomers could not be disrupted by inverse agonists targeting either one of the receptor constituents. However, D2 did not heterooligomerize with the structurally modified D1(S198A/S199A), indicating an impaired interface for their interaction. Thus, we describe a novel method showing that a homogeneous receptor conformation maintains the structural integrity of oligomers, whereas conformational heterogeneity disrupts it.

  3. Roundabout receptors.

    PubMed

    Ypsilanti, Athéna R; Chedotal, Alain

    2014-01-01

    Roundabout receptors (Robo) and their Slit ligands were discovered in the 1990s and found to be key players in axon guidance. Slit was initially described s an extracellular matrix protein that was expressed by midline glia in Drosophila. A few years later, it was shown that, in vertebrates and invertebrates, Slits acted as chemorepellents for axons crossing the midline. Robo proteins were originally discovered in Drosophila in a mutant screen for genes involved in the regulation of midline crossing. This ligand-receptor pair has since been implicated in a variety of other neuronal and non-neuronal processes ranging from cell migration to angiogenesis, tumourigenesis and even organogenesis of tissues such as kidneys, lungs and breasts.

  4. Angular cheilitis occurring during orthodontic treatment: a case series.

    PubMed

    Cross, David L; Short, Laura J

    2008-12-01

    Clinical experience has shown that angular cheilitis can occur during orthodontic treatment and may persist into retention, but the incidence of the condition is unknown. The purpose of this paper is to increase the awareness among clinicians of angular cheilitis occurring during orthodontic treatment. It also proposes a treatment regime which may be used.

  5. 32 CFR 716.6 - Death occurring after active service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 5 2011-07-01 2011-07-01 false Death occurring after active service. 716.6 Section 716.6 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL DEATH GRATUITY Provisions Applicable to the Navy and the Marine Corps § 716.6 Death occurring after active...

  6. 32 CFR 716.6 - Death occurring after active service.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 5 2014-07-01 2014-07-01 false Death occurring after active service. 716.6 Section 716.6 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL DEATH GRATUITY Provisions Applicable to the Navy and the Marine Corps § 716.6 Death occurring after active...

  7. 32 CFR 716.6 - Death occurring after active service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Death occurring after active service. 716.6 Section 716.6 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL DEATH GRATUITY Provisions Applicable to the Navy and the Marine Corps § 716.6 Death occurring after active...

  8. 32 CFR 716.6 - Death occurring after active service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 5 2012-07-01 2012-07-01 false Death occurring after active service. 716.6 Section 716.6 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL DEATH GRATUITY Provisions Applicable to the Navy and the Marine Corps § 716.6 Death occurring after active...

  9. 32 CFR 716.6 - Death occurring after active service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 5 2013-07-01 2013-07-01 false Death occurring after active service. 716.6 Section 716.6 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL DEATH GRATUITY Provisions Applicable to the Navy and the Marine Corps § 716.6 Death occurring after active...

  10. Co-occurring disorders in children who stutter.

    PubMed

    Blood, Gordon W; Ridenour, Victor J; Qualls, Constance Dean; Hammer, Carol Scheffner

    2003-01-01

    This study used a mail survey to determine the (a) percentage of children who stutter with co-occurring non-speech disorders, speech disorders, and language disorders, and (b) frequency, length of sessions, and type of treatment services provided for children who stutter with co-occurring disorders. Respondents from a nationwide sample included 1184 speech-language pathologists (SLPs). Of the 2628 children who stuttered, 62.8% had other co-occurring speech disorders, language disorders, or non-speech-language disorders. Articulation disorders (33.5%) and phonology disorders (12.7%) were the most frequently reported co-occurring speech disorders. Only 34.3% of the children who stuttered had co-occurring non-speech-language disorders. Of those children with co-occurring non-speech-language disorders, learning disabilities (15.2%), literacy disorders (8.2%), and attention deficit disorders (ADD) (5.9%) were the most frequently reported. Chi-square analyses revealed that males were more likely to exhibit co-occurring speech disorders than females, especially articulation and phonology. Co-occurring non-speech-language disorders were also significantly higher in males than females. Treatment decisions by SLPs are also discussed. As a result of this activity, the participant should: (1) have a better understanding of the co-occurring speech disorders, language disorders, and non-speech disorders in children who stutter; (2) identify the speech disorders, language disorders, and non-speech disorders with the highest frequency of occurrence in children who stutter; and (3) be aware of the subgroups of children with co-occurring disorders and their potential impact on assessment and treatment.

  11. Differential neuropsychopharmacological influences of naturally occurring tropane alkaloids anisodamine versus scopolamine.

    PubMed

    Zhang, Wei-Wei; Song, Ming-Ke; Cui, Yong-Yao; Wang, Hao; Zhu, Liang; Niu, Yin-Yao; Yang, Li-Min; Lu, Yang; Chen, Hong-Zhuan

    2008-10-10

    Two naturally occurring tropane alkaloids, anisodamine and scopolamine, structurally dissimilar in one OH group, are well established as muscarinic acetylcholine receptor (mAChR) antagonists in clinic and basic research. However, experimental evidence for central effects of anisodamine is limited and conflicting compared with that of scopolamine. In the present study, Morris water maze test, long-term potentiation (LTP) recording and receptor radioligand binding assays were used to explore the disparity in neuropsychopharmacological influences of anisodamine versus scopolamine and possible mechanisms. Anisodamine, at 10-40-fold higher doses than those of scopolamine, did not produce any spatial cognitive deficits as scopolamine, but tended to improve cognition at the repeated high doses. LTP in vivo was then adopted to predict BBB permeability of the muscarinic antagonists following systemic drug administration. Contrary to scopolamine, anisodamine did not influence the formation of LTP in the CA(1) region of rat hippocampus at 40-fold higher dose than that of scopolamine. Additionally, receptor radioligand binding assays (RRLBA) revealed that the binding affinity of anisodamine to mice brain mAChR was much lower than that of scopolamine. The findings suggested that anisodamine did not impair cognition nor depress LTP primarily due to its poor BBB permeability. This work enlarged knowledge of structure-activity relationship among tropane alkaloids, meanwhile providing evidence for more reasonable drug prescription in clinic.

  12. Rubemamine and Rubescenamine, Two Naturally Occurring N-Cinnamoyl Phenethylamines with Umami-Taste-Modulating Properties.

    PubMed

    Backes, Michael; Obst, Katja; Bojahr, Juliane; Thorhauer, Anika; Roudnitzky, Natacha; Paetz, Susanne; Reichelt, Katharina V; Krammer, Gerhard E; Meyerhof, Wolfgang; Ley, Jakob P

    2015-10-07

    Sensory screening of a series of naturally occurring N-cinnamoyl derivatives of substituted phenethylamines revealed that rubemamine (9, from Chenopodium album) and rubescenamine (10, from Zanthoxylum rubsecens) elicit strong intrinsic umami taste in water at 50 and 10 ppm, respectively. Sensory tests in glutamate- and nucleotide-containing bases showed that the compounds influence the whole flavor profile of savory formulations. Both rubemamine (9) and rubescenamine (10) at 10-100 ppm dose-dependently positively modulated the umami taste of MSG (0.17-0.22%) up to threefold. Among the investigated amides, only rubemamine (9) and rubescenamine (10) are able to directly activate the TAS1R1-TAS1R3 umami taste receptor. Moreover, both compounds also synergistically modulated the activation of TAS1R1-TAS1R3 by MSG. Most remarkably, rubemamine (9) was able to further positively modulate the IMP-enhanced TAS1R1-TAS1R3 response to MSG ∼ 1.8-fold. Finally, armatamide (11), zanthosinamide (13), and dioxamine (14), which lack intrinsic umami taste in vivo and direct receptor response in vitro, also positively modulated receptor activation by MSG about twofold and the IMP-enhanced MSG-induced TAS1R1-TAS1R3 responses approximately by 50%. In sensory experiments, dioxamine (14) at 25 ppm in combination with 0.17% MSG exhibited a sensory equivalent to 0.37% MSG.

  13. Alcohol Dependence, Co-occurring Conditions and Attributable Burden

    PubMed Central

    Odlaug, B.L.; Gual, A.; DeCourcy, J.; Perry, R.; Pike, J.; Heron, L.; Rehm, J.

    2016-01-01

    Aims Alcohol dependence is associated with high rates of co-occurring disorders which impact health-related quality of life (HRQoL) and add to the cost-of-illness. This study investigated the burden of alcohol dependence and associated co-occurring conditions on health and productivity. Methods A cross-sectional survey was conducted in eight European countries. Physicians (Psychiatrists and General Practitioners) completed patient record forms, which included assessment of co-occurring conditions, and patients completed matching self-completion forms. Drinking risk level (DRL) was calculated and the relationship between DRL, co-occurring conditions, work productivity, hospitalisations and rehabilitation stays was explored. Results Data were collected for 2979 alcohol-dependent patients (mean age 48.8 ± 13.6 years; 70% male). In total, 77% of patients suffered from moderate-to-severe co-occurring psychiatric and/or somatic conditions. High DRL was significantly associated with depression, greater work productivity losses, increased hospitalisations and rehabilitation stays. Co-occurring conditions were significantly associated with poorer HRQoL and decreased work productivity, with a statistical trend towards an increased frequency of rehabilitation stays. Conclusions Alcohol-dependent patients manifest high rates of co-occurring psychiatric and somatic conditions, which are associated with impaired work productivity and HRQoL. The continued burden of illness observed in these already-diagnosed patients suggests an unmet need in both primary and secondary care. PMID:26246514

  14. Prevention of spinal cord injuries that occur in swimming pools.

    PubMed

    DeVivo, M J; Sekar, P

    1997-08-01

    The purpose of this study was to determine the usual circumstances surrounding spinal cord injuries that occur in swimming pools so that appropriate primary prevention programs targeted at high risk persons, activities, and environments could be developed and initiated. A sample of 341 persons enrolled in the National Spinal Cord Injury Statistical Center database since 1973 whose injury was the result of a swimming pool mishap was identified. Medical records were reviewed retrospectively and a survey questionnaire was administered by telephone to 196 persons (57.5%) who were located and agreed to participate. Average age at time of injury was 24 years, 86% of injured persons were men, 95% were white, 70% were never married, 32% had less than a high school education, and only 7% were college graduates. Almost all injuries (87%) occurred in private/residential pools. Most injuries (57%) occurred when diving into less than 4 feet of water, while an additional 38% occurred at water depths between 4 and 8 feet. Depth indicators were not present in 75% of cases. There were no warning signs posted in 87% of cases. There was no lifeguard on duty in 94% of cases. There was self-reported alcohol involvement in 49% of cases, but drugs were involved in only 2% of cases. Almost half of all injuries (46%) occurred during parties. In 44% of cases, the injury occurred during the person's first visit to that particular pool. Ordinary dives accounted for 70% of cases, followed by unusual dives (17%), unintentional pushes (6%), and other circumstances (7%). Almost all injuries (88%) occurred between 1 pm and 1 am with the most frequent time of day being 6 pm, and 82% occurred during June, July or August. Over half (51%) of all injuries occurred on Saturday or Sunday. These results provide important clues to the development of a successful primary prevention program.

  15. Drosophila TRPA1 channel is required to avoid the naturally occurring insect repellent citronellal

    PubMed Central

    Kwon, Young; Kim, Sang Hoon; Ronderos, David S.; Lee, Youngseok; Akitake, Bradley; Woodward, Owen M.; Guggino, William B.; Smith, Dean P.; Montell, Craig

    2010-01-01

    Summary Plants produce naturally occurring insect repellents, such as citronellal, which is the main component of citronellal oil and is among the most widely-used-naturally-occurring insect repellents. However, the molecular pathways through which insects sense botanical repellents are unknown. Here, we showed that Drosophila used two pathways for direct avoidance of citronellal. The olfactory co-receptor, Or83b, which is required for the response to the synthetic repellent DEET, contributed to citronellal repulsion, and was essential for citronellal-evoked action potentials. Mutations affecting the Ca2+-permeable cation channel, TRPA1 resulted in a comparable defect in avoiding citronellal vapor. The TRPA1-dependent aversion to citronellal relied on a G protein/phospholipase C (PLC) signaling cascade, rather than direct detection of citronellal by TRPA1. Loss of TRPA1, Gq or PLC caused an increase in the frequency of citronellal-evoked action potentials in olfactory receptor neurons. Absence of the Ca2+-activated K+ channel, Slowpoke, resulted in a similar impairment in citronellal avoidance, and an increase in the frequency of action potentials. These results suggest that TRPA1 is required for activation of a BK channel to modulate citronellal-evoked action potentials, and for aversion to citronellal. In contrast to Drosophila TRPA1, Anopheles gambiae TRPA1 was directly and potently activated by citronellal, thereby raising the possibility that mosquito TRPA1 may be a target for developing improved repellents to reduce insect-borne diseases such as malaria. PMID:20797863

  16. 33 CFR 330.3 - Activities occurring before certain dates.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... (section 404) (b) Structures or work completed before December 18, 1968, or in waterbodies over which the DE had not asserted jurisdiction at the time the activity occurred, provided in both instances, there...

  17. 33 CFR 330.3 - Activities occurring before certain dates.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... (section 404) (b) Structures or work completed before December 18, 1968, or in waterbodies over which the DE had not asserted jurisdiction at the time the activity occurred, provided in both instances, there...

  18. Comparative Toxicology of Libby Amphibole and Naturally Occurring Asbestos

    EPA Science Inventory

    Summary sentence: Comparative toxicology of Libby amphibole (LA) and site-specific naturally occurring asbestos (NOA) provides new insights on physical properties influencing health effects and mechanisms of asbestos-induced inflammation, fibrosis, and tumorigenesis.Introduction/...

  19. Comparative Toxicology of Libby Amphibole and Naturally Occurring Asbestos

    EPA Science Inventory

    Summary sentence: Comparative toxicology of Libby amphibole (LA) and site-specific naturally occurring asbestos (NOA) provides new insights on physical properties influencing health effects and mechanisms of asbestos-induced inflammation, fibrosis, and tumorigenesis.Introduction/...

  20. Parkinson's Disease and Melanoma May Occur Together, Study Finds

    MedlinePlus

    ... gov/news/fullstory_167078.html Parkinson's Disease and Melanoma May Occur Together, Study Finds Doctors should counsel ... are about four times more likely to develop melanoma skin cancer, and conversely, people with melanoma have ...

  1. Chemotactic peptide receptor modulation in polymorphonuclear leukocytes

    PubMed Central

    1980-01-01

    The binding of the chemotactic peptide N- formylnorleucylleucylphenylalanine (FNLLP) to its receptor on rabbit polymorphonuclear leukocytes (PMNs) modulates the number of available peptide receptors. Incubation with FNLLP decreases subsequent binding capacity, a phenomenon that has been termed receptor down regulation. Down regulation of the chemotactic peptide receptor is concentration dependent in both the rate and extent of receptor loss. The dose response parallels that of FNLLP binding to the recptor. The time- course is rapid; even at concentrations of FNLLP as low as 3 x 10(-9) M, the new equilibrium concentration of receptors is reached within 15 min. Down regulation is temperature dependent, but does occur even at 4 degrees C. Concomitant with down regulation, some of the peptide becomes irreversibly cell associated. At 4 degrees C, there is a small accumulation of nondissociable peptide that rapidly reaches a plateau. At higher temperatures, accumulation of nondissociable peptide continues after the rceptor number has reached equilibrium, and the amount accumulated can exceed the initial number of receptors by as much as 300%. The dose response of peptide uptake at 37 degrees C reflects that of binding, suggesting that it is receptor mediated. This uptake may occur via a pinocytosis mechanism. Although PMNs have not been considered to be pinocytic, the addition of FNLLP causes a fourfold stimulation of the rate of pinocytosis as measured by the uptake of [3H]sucrose. PMID:7391138

  2. Intracellular insulin-receptor dissociation and segregation in a rat fibroblast cell line transfected with a human insulin receptor gene

    SciTech Connect

    Levy, J.R.; Olefsky, J.M.

    1988-05-05

    The cellular processing of insulin and insulin receptors was studied using a rat fibroblast cell line that had been transfected with a normal human insulin receptor gene, expressing approximately 500 times the normal number of native fibroblasts insulin receptors. These cells bind and internalize insulin normally. Biochemically assays based on the selective precipitation by polyethylene glycol of intact insulin-receptor complexes but not of free intracellular insulin were developed to study the time course of intracellular insulin-receptor dissociation. Fibroblasts were incubated with radiolabeled insulin at 4/sup 0/C, and internalization of insulin-receptor complexes was initiated by warming the cells to 37/sup 0/C. Within 2 min, 90% of the internalized radioactivity was composed of intact insulin-receptor complexes. The dissociation of insulin from internalized insulin-receptor complexes was markedly inhibited by monensin and chloroquine. Furthermore, chloroquine markedly increased the number of cross-linkable intracellular insulin-receptor complexes, as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis autoradiography. These findings suggest that acidification of intracellular vesicles is responsible for insulin-receptor dissociation. Physical segregation of dissociated intracellular insulin from its receptor was monitored. The results are consistent with the view that segregation of insulin and receptor occurs 5-10 min after initiation of dissociation. These studies demonstrate the intracellular itinerary of insulin-receptor complexes, including internalization, dissociation of insulin from the internalized receptor within an acidified compartment, segregation of insulin from the receptor, and subsequent ligand degradation.

  3. The acetylcholine receptor as a cellular receptor for rabies virus.

    PubMed

    Lentz, T L; Burrage, T G; Smith, A L; Tignor, G H

    1983-01-01

    Characterization of specific host cell receptors for enveloped viruses is a difficult problem because many enveloped viruses bind to a variety of substrates which are not obviously related to tissue tropisms in the intact host. Viruses with a limited cellular tropism in infected animals present useful models for studying the mechanisms by which virus attachment regulates the disease process. Rabies virus is a rhabdovirus which exhibits a marked neuronotropism in infected animals. Limited data suggest that spread occurs by transsynaptic transfer of virus. The results of recent experiments at Yale suggest that viral antigen is localized very soon after injection at neuromuscular junctions, the motor nerve endings on muscle tissue. On cultured muscle cells, similar co-localization with the acetylcholine receptor is seen both before and after virus multiplication. Pretreatment of these cells with some ligands of the acetylcholine receptor results in reduced viral infection. These findings suggest that a neurotransmitter receptor or a closely associated molecule may serve as a specific host cell receptor for rabies virus and thus may be responsible for the tissue tropism exhibited by this virus. In addition to clarifying aspects of rabies virus pathogenesis, these studies have broad implications regarding the mechanism by which other viruses or viral immunizations might mediate autoimmune diseases such as myasthenia gravis.

  4. Gβ promotes pheromone receptor polarization and yeast chemotropism by inhibiting receptor phosphorylation

    PubMed Central

    Ismael, Amber; Tian, Wei; Waszczak, Nicholas; Wang, Xin; Cao, Youfang; Suchkov, Dmitry; Bar, Eli; Metodiev, Metodi V.; Liang, Jie; Arkowitz, Robert; Stone, David E.

    2016-01-01

    Gradient-directed cell migration (chemotaxis) and growth (chemotropism) are universal processes, which are essential to the development and life cycles of all species. Cells use surface receptors to sense the shallow chemical gradients that elicit chemotaxis and chemotropism. Slight asymmetries in receptor activation are amplified by downstream signaling systems, which ultimately induce dynamic reorganization of the cytoskeleton. During the mating response of budding yeast, a model chemotropic system, the pheromone receptor on the plasma membrane polarizes to the side of the cell closest to the stimulus. Although receptor polarization occurs before and independently of actin-cable dependent vesicle delivery (directed secretion), it requires receptor internalization. Phosphorylation of pheromone receptors by yeast casein kinase 1 or 2 (Yck1/2) stimulates their internalization. We showed that the pheromone-responsive Gβγ dimer promotes the polarization of the pheromone receptor by interacting with Yck1/2 and locally inhibiting receptor phosphorylation. We also found that receptor phosphorylation is essential for chemotropism, independent of its role in inducing receptor internalization. A mathematical model supports the idea that the interaction between Gβγ and Yck1/2 results in differential phosphorylation and internalization of the pheromone receptor and accounts for its polarization before the initiation of directed secretion. PMID:27072657

  5. Gβ promotes pheromone receptor polarization and yeast chemotropism by inhibiting receptor phosphorylation.

    PubMed

    Ismael, Amber; Tian, Wei; Waszczak, Nicholas; Wang, Xin; Cao, Youfang; Suchkov, Dmitry; Bar, Eli; Metodiev, Metodi V; Liang, Jie; Arkowitz, Robert A; Stone, David E

    2016-04-12

    Gradient-directed cell migration (chemotaxis) and growth (chemotropism) are processes that are essential to the development and life cycles of all species. Cells use surface receptors to sense the shallow chemical gradients that elicit chemotaxis and chemotropism. Slight asymmetries in receptor activation are amplified by downstream signaling systems, which ultimately induce dynamic reorganization of the cytoskeleton. During the mating response of budding yeast, a model chemotropic system, the pheromone receptors on the plasma membrane polarize to the side of the cell closest to the stimulus. Although receptor polarization occurs before and independently of actin cable-dependent delivery of vesicles to the plasma membrane (directed secretion), it requires receptor internalization. Phosphorylation of pheromone receptors by yeast casein kinase 1 or 2 (Yck1/2) stimulates their internalization. We showed that the pheromone-responsive Gβγ dimer promotes the polarization of the pheromone receptor by interacting with Yck1/2 and locally inhibiting receptor phosphorylation. We also found that receptor phosphorylation is essential for chemotropism, independently of its role in inducing receptor internalization. A mathematical model supports the idea that the interaction between Gβγ and Yck1/2 results in differential phosphorylation and internalization of the pheromone receptor and accounts for its polarization before the initiation of directed secretion.

  6. CGRP and its receptors.

    PubMed

    Hay, Debbie L; Walker, Christopher S

    2017-02-24

    The calcitonin gene-related peptide (CGRP) neuropeptide system is an important but still evolving target for migraine. A fundamental consideration for all of the current drugs in clinical trials and for ongoing development in this area is the identity, expression pattern, and function of CGRP receptors because this knowledge informs safety and efficacy considerations. In recent years, only the calcitonin receptor-like receptor/receptor activity-modifying protein 1 (RAMP1) complex, known as the CGRP receptor, has generally been considered relevant. However, CGRP is capable of activating multiple receptors and could have more than one endogenous receptor. The recent identification of the CGRP-responsive calcitonin receptor/RAMP1 complex (AMY1 receptor - amylin subtype 1 receptor) in the trigeminovascular system warrants a deeper consideration of the molecular identity of CGRP receptor(s) involved in the pathophysiology, and thus potential treatment of migraine. This perspective considers some of the issues and implications.

  7. The LDL receptor.

    PubMed

    Goldstein, Joseph L; Brown, Michael S

    2009-04-01

    In this article, the history of the LDL receptor is recounted by its codiscoverers. Their early work on the LDL receptor explained a genetic cause of heart attacks and led to new ways of thinking about cholesterol metabolism. The LDL receptor discovery also introduced three general concepts to cell biology: receptor-mediated endocytosis, receptor recycling, and feedback regulation of receptors. The latter concept provides the mechanism by which statins selectively lower plasma LDL, reducing heart attacks and prolonging life.

  8. On co-design of filter and fault estimator against randomly occurring nonlinearities and randomly occurring deception attacks

    NASA Astrophysics Data System (ADS)

    Hu, Jun; Liu, Steven; Ji, Donghai; Li, Shanqiang

    2016-07-01

    In this paper, the co-design problem of filter and fault estimator is studied for a class of time-varying non-linear stochastic systems subject to randomly occurring nonlinearities and randomly occurring deception attacks. Two mutually independent random variables obeying the Bernoulli distribution are employed to characterize the phenomena of the randomly occurring nonlinearities and randomly occurring deception attacks, respectively. By using the augmentation approach, the co-design problem of the robust filter and fault estimator is converted into the recursive filter design problem. A new compensation scheme is proposed such that, for both randomly occurring nonlinearities and randomly occurring deception attacks, an upper bound of the filtering error covariance is obtained and such an upper bound is minimized by properly designing the filter gain at each sampling instant. Moreover, the explicit form of the filter gain is given based on the solution to two Riccati-like difference equations. It is shown that the proposed co-design algorithm is of a recursive form that is suitable for online computation. Finally, a simulation example is given to illustrate the usefulness of the developed filtering approach.

  9. Arsenic poisoning in dairy cattle from naturally occurring arsenic pyrites.

    PubMed

    Hopkirk, R G

    1987-10-01

    An outbreak of arsenic poisoning occurred in which most of a 200 cow dairy herd were affected and six died. The source of the arsenic was naturally occurring arsenic pyrites from the Waiotapu Stream, near Rotorua. Arsenic levels in the nearby soil were as high as 6618 ppm. There was little evidence to suggest that treatment affected the course of the disease. Haematology was of little use in diagnosis, post-mortem signs were not always consistent and persistence of the element in the liver appeared short. Control of further outbreaks have been based on practical measures to minimise the intake of contaminated soil and free laying water by the stock.

  10. Factors affecting the depth of burns occurring in medical institutions.

    PubMed

    Cho, Young Soon; Choi, Young Hwan; Yoon, Cheonjae; You, Je Sung

    2015-05-01

    Most cases of burns occurring in medical institutions are associated with activities involving heat. It is very difficult to detect these burns. To date, there are few reports on burns occurring in medical institutions. The purpose of this paper was to analyze the etiology of burns occurring in medical institutions and to elucidate the factors affecting burn depth. We conducted a retrospective analysis of the medical records of patients who visited our center from April 2008 to February 2013. This study enrolled all patients with burns occurring in the medical institution during or related to treatment. We excluded burn patients whose burns were not related to treatment (for example, we excluded patients with scalding burns that occurred in the hospital cafeteria and pediatric patients with hot water burns from the water purifier). However, patients with burns that occurred in the recovery room after general anesthesia were included. A total of 115 patients were enrolled in this study. The average patient age was 41.5 years, with more women than men (M:F=31:84). There were 29 cases (25.3%) of superficial burns (first-degree and superficial second-degree) and 86 cases (74.7%) of deep burns (deep second-degree and third-degree). Hot packs were the most common cause of burns (27 cases, 23.5%), followed by laser therapy, heating pads, and grounding pads, accounting for 15 cases each. There were 89 cases (77.4%) of contact burns and 26 cases (22.6%) of non-contact burns. The most common site of burns was the lower extremities (41 cases, 35.7%). The burn site and contact burns were both factors affecting burn depth. The rate of deep burns was higher in patients with contact burns than in those with non-contact burns (odds ratio 4.26) and was associated with lower body burns (odds ratio 2.85). In burns occurring in medical institutions, there is a high probability of a deep burn if it is a contact burn or occurs in the lower body. Therefore, safety guidelines are needed

  11. Addressing Naturally Occurring Asbestos in the Mining Industry

    NASA Astrophysics Data System (ADS)

    Bieber, D. W.

    2012-12-01

    Mining companies deal with naturally occurring asbestos (NOA) issues on their sites in two ways, avoidance and management. Avoidance simply means that to the extent practical, new mines are located in areas where NOA is unlikely to occur. Where mines are located in areas where NOA may be present, mines implement management procedures to identify and control potential sources of NOA. Management practices may include procedures set forth in regulations such as California's Air Toxicity Control Measure that deals with surface mining, voluntary procedures, or a combination of both. The mining industry generally recognizes that addressing NOA issues is a cost of doing business.;

  12. Naturally occurring and forced azimuthal modes in a turbulent jet

    NASA Technical Reports Server (NTRS)

    Raman, Ganesh; Rice, Edward J.; Reshotko, Eli

    1991-01-01

    Naturally occurring instability modes in an axisymmetric jet are studied utilizing the modal frequency spectrum method. In the early evolution of the jet the axisymmetric mode was predominant, with the azimuthal modes growing quickly but dominating only after the end of the potential core. The growth of the azimuthal modes is seen nearer to the nozzle exit for the jet in the laminar boundary layer case than for the turbulent. Based on the results from these naturally occurring jet instability mode tests, target modes for efficient excitation were determined and two cases of excitation were examined.

  13. Effects of naturally occurring coumarins on hepatic drug-metabolizing enzymes inmice

    SciTech Connect

    Kleiner, Heather E. Xia, Xiaojun; Sonoda, Junichiro; Zhang, Jun; Pontius, Elizabeth; Abey, Jane; Evans, Ronald M.; Moore, David D.; DiGiovanni, John

    2008-10-15

    Cytochromes P450 (P450s) and glutathione S-transferases (GSTs) constitute two important enzyme families involved in carcinogen metabolism. Generally, P450s play activation or detoxifying roles while GSTs act primarily as detoxifying enzymes. We previously demonstrated that oral administration of the linear furanocoumarins, isopimpinellin and imperatorin, modulated P450 and GST activities in various tissues of mice. The purpose of the present study was to compare a broader range of naturally occurring coumarins (simple coumarins, and furanocoumarins of the linear and angular type) for their abilities to modulate hepatic drug-metabolizing enzymes when administered orally to mice. We now report that all of the different coumarins tested (coumarin, limettin, auraptene, angelicin, bergamottin, imperatorin and isopimpinellin) induced hepatic GST activities, whereas the linear furanocoumarins possessed the greatest abilities to induce hepatic P450 activities, in particular P450 2B and 3A. In both cases, this corresponded to an increase in protein expression of the enzymes. Induction of P4502B10, 3A11, and 2C9 by xenobiotics often is a result of activation of the pregnane X receptor (PXR) and/or constitutive androstane receptor (CAR). Using a pregnane X receptor reporter system, our results demonstrated that isopimpinellin activated both PXR and its human ortholog SXR by recruiting coactivator SRC-1 in transfected cells. In CAR transfection assays, isopimpinellin counteracted the inhibitory effect of androstanol on full-length mCAR, a Gal4-mCAR ligand-binding domain fusion, and restored coactivator binding. Orally administered isopimpinellin induced hepatic mRNA expression of Cyp2b10, Cyp3a11, and GSTa in CAR(+/+) wild-type mice. In contrast, the induction of Cyp2b10 mRNA by isopimpinellin was attenuated in the CAR(-/-) mice, suggesting that isopimpinellin induces Cyp2b10 via the CAR receptor. Overall, the current data indicate that naturally occurring coumarins have

  14. Tyrosine phosphorylation of glutamate receptors by non-receptor tyrosine kinases: roles in depression-like behavior

    PubMed Central

    Mao, Li-Min; Wang, John Q.

    2016-01-01

    Several key members of the non-receptor tyrosine kinase (nRTK) family are abundantly present within excitatory synapses in the mammalian brain. These neuron-enriched nRTKs interact with glutamate receptors and phosphorylate the receptors at tyrosine sites. The N-methyl-D-aspartate receptor is a direct substrate of nRTKs and has been extensively investigated in its phosphorylation responses to nRTKs. The α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor is the other glutamate receptor subtype that is subject to nRTK-mediated tyrosine phosphorylation. Recently, group I metabotropic glutamate receptors (mGluR1/5) were found to be sensitive to nRTKs. Robust tyrosine phosphorylation may occur in C-terminal tails of mGluR5. Tyrosine phosphorylation of glutamate receptors is either constitutive or induced activity-dependently by changing cellular and/or synaptic input. Through inducing tyrosine phosphorylation, nRTKs regulate trafficking, subcellular distribution, and function of modified receptors. Available data show that nRTK-glutamate receptor interactions and tyrosine phosphorylation of the receptors undergo drastic adaptations in mood disorders such as major depressive disorder. The remodeling of the nRTK-glutamate receptor interplay contributes to the long-lasting pathophysiology and symptomology of depression. This review summarizes the recent progress in tyrosine phosphorylation of glutamate receptors and analyzes the role of nRTKs in regulating glutamate receptors and depression-like behavior. PMID:26942227

  15. On properties of certain classical operators occurring in Fourier analysis

    NASA Astrophysics Data System (ADS)

    Zhizhiashvili, L. V.; Tkebuchava, G. E.

    2004-10-01

    Properties of conjugate functions, Hilbert transforms, and certain maximal operators occurring in Fourier analysis in weighted Lebesgue spaces are established. For functions of several variables in Orlicz spaces the divergence in measure of the Cesáro and the Abel means of the conjugate trigonometric series, and the question of the existence of conjugate functions are investigated.

  16. On properties of certain classical operators occurring in Fourier analysis

    SciTech Connect

    Zhizhiashvili, L V; Tkebuchava, G E

    2004-10-31

    Properties of conjugate functions, Hilbert transforms, and certain maximal operators occurring in Fourier analysis in weighted Lebesgue spaces are established. For functions of several variables in Orlicz spaces the divergence in measure of the Cesaro and the Abel means of the conjugate trigonometric series, and the question of the existence of conjugate functions are investigated.

  17. Neutropenia occurring after starting gabapentin for neuropathic pain.

    PubMed

    Derbyshire, E; Martin, D

    2004-12-01

    We report a case of neutropenia occurring in a patient receiving gabapentin for neuropathic pain. Five weeks after treatment started, the patient was admitted to hospital with neutropenic sepsis. Gabapentin is widely used, and neutropenia is a rare adverse effect. This case highlights a serious and potential life-threatening complication.

  18. Syntheses of naturally occurring terphenyls and related compounds.

    PubMed

    Sawayama, Yusuke; Tsujimoto, Takashi; Sugino, Kumi; Nishikawa, Toshio; Isobe, Minoru; Kawagishi, Hirokazu

    2006-12-01

    Naturally occurring terphenyls and related compounds such as terferol and its corresponding quinone and phlebiarubrone were synthesized from 2,5-diphenyl-1,4-benzoquinone. According to the proposed biosynthetic pathway, chemical conversion of phlebiarubrone to ustalic acid, a toxic compound isolated from the poisonous mushroom, Tricholoma ustale, was examined to find a low-yield conversion to the ustalic acid dimethyl ester.

  19. URBAN STORMWATER TRACING WITH THE NATURALLY OCCURRING DEUTERIUM ISOTOPE

    EPA Science Inventory

    Measurements of the naturally-occurring deuterium isotope assist the tracing of water components during wet-weather flows in an urban watershed. A transect of installations in the vadose and saturated zones was completed in the vicinity of a small stream and storm sewer. High-r...

  20. Naturally occurring fatty acids: Source, chemistry, and uses

    USDA-ARS?s Scientific Manuscript database

    Natural occurring fatty acids are a large and complex class of compounds found in plants and animals. Fatty acids are abundant and of interest because of their renewability, biodegradability, biocompatibility, low cost, and fascinating chemistry. Of the many fatty acids, only 20-25 of them are widel...

  1. Temporal Sequencing of Brain Activations During Naturally Occurring Thermoregulatory Events

    PubMed Central

    Diwadkar, Vaibhav A.; Murphy, Eric R.; Freedman, Robert R.

    2014-01-01

    Thermoregulatory events are associated with activity in the constituents of the spinothalamic tract. Whereas studies have assessed activity within constituents of this pathway, in vivo functional magnetic resonance imaging (fMRI) studies have not determined if neuronal activity in the constituents of the tract is temporally ordered. Ordered activity would be expected in naturally occurring thermal events, such as menopausal hot flashes (HFs), which occur in physiological sequence. The origins of HFs may lie in brainstem structures where neuronal activity may occur earlier than in interoceptive centers, such as the insula and the prefrontal cortex. To study such time ordering, we conducted blood oxygen level-dependent-based fMRI in a group of postmenopausal women to measure neuronal activity in the brainstem, insula, and prefrontal cortex around the onset of an HF (detected using synchronously acquired skin conductance responses). Rise in brainstem activity occurred before the detectable onset of an HF. Activity in the insular and prefrontal trailed that in the brainstem, appearing following the onset of the HF. Additional activations associated with HF's were observed in the anterior cingulate cortex and the basal ganglia. Pre-HF brainstem responses may reflect the functional origins of internal thermoregulatory events. By comparison insular, prefrontal and striatal activity may be associated with the phenomenological correlates of HFs. PMID:23787950

  2. On Translating French Occurring in English into Spanish.

    ERIC Educational Resources Information Center

    Sebastian, Robert N.

    1989-01-01

    Explores problems encountered during attempts to translate French expressions occurring in English (such as concierge) into Spanish, particularly when the English interpretation of the expression is different from the standard French usage. Spanish translations are provided for about 200 French terms and expressions commonly used in English. (61…

  3. Changes occurring to minimally disturbed soil and to plant covers

    USDA-ARS?s Scientific Manuscript database

    During the transition to organic production certain materials and practices, as described under US law, can not be used. During the transition period growers may, or may not, disturb the soil. There is little known about changes that occur if the soil is minimally disturbed during the transition t...

  4. Integrative Priming Occurs Rapidly and Uncontrollably during Lexical Processing

    ERIC Educational Resources Information Center

    Estes, Zachary; Jones, Lara L.

    2009-01-01

    Lexical priming, whereby a prime word facilitates recognition of a related target word (e.g., "nurse" [right arrrow] "doctor"), is typically attributed to association strength, semantic similarity, or compound familiarity. Here, the authors demonstrate a novel type of lexical priming that occurs among unassociated, dissimilar,…

  5. RUN OUTS OCCUR WHEN IRON HAS UNSEATED MOLDING SAND AND ...

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

    RUN OUTS OCCUR WHEN IRON HAS UNSEATED MOLDING SAND AND RUN OUT OF THE MOLD UNDER POURING JACKETS AND SPILLS ONTO THE MOLDING PLATFORM. WORKERS GENERALLY WAIT SEVERAL MINUTES FOR THE IRON TO SOLIDIFY AND, WHILE IT IS STILL RED-HOT, REMOVE IT FROM THE PLATFORM AND SCRAP THE MOLD. - Southern Ductile Casting Company, Centerville Foundry, 101 Airport Road, Centreville, Bibb County, AL

  6. RUN OUTS OCCUR WHEN IRON HAS UNSEATED MOLDING SAND AND ...

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

    RUN OUTS OCCUR WHEN IRON HAS UNSEATED MOLDING SAND AND RUN OUT OF THE MOLD UNDER POURING JACKETS AND SPILLS ONTO THE MOLDING PLATFORM. WORKERS GENERALLY WAIT SEVERAL MINUTES FOR THE IRON TO SOLIDIFY AND, WHILE IT IS STILL RED-HOT, REMOVE IT FROM THE PLATFORM AND SCRAP THE MOLD. - Southern Ductile Casting Company, Centerville Foundry, 101 Airport Road, Centreville, Bibb County, AL

  7. Factors Related to Learning Occurring in an Adult Education Program.

    ERIC Educational Resources Information Center

    Okoro, Daniel; Miller, Larry E.

    A study examined the factors related to learning occurring in an adult education program. A purposeful sample of Ohio counties and 151 participants in a specific 1993-1993 adult education program who self-selected to participate in the study was used. A descriptive ex post facto study design was used. Pretests-posttests were administered to…

  8. Binding of rabies virus to purified Torpedo acetylcholine receptor.

    PubMed

    Lentz, T L; Benson, R J; Klimowicz, D; Wilson, P T; Hawrot, E

    1986-12-01

    The binding of 125I- and 35S-labeled rabies virus (CVS strain) to affinity-purified acetylcholine receptor from Torpedo electric organ was demonstrated. The binding of rabies virus to the acetylcholine receptor increased with increasing receptor concentration, was dependent on the pH of the incubation medium, and was saturable with increasing virus concentration. Binding of radioactively labeled virus was effectively competed by unlabeled homologous virus particles. Binding of 35S-labeled rabies virus to the AChR was inhibited up to 50% by alpha-bungarotoxin and up to 30% by (+)-tubocurarine but was not affected by atropine. These results demonstrate direct binding of rabies virus to a well-defined neurotransmitter receptor, namely the acetylcholine receptor and indicate that at least a portion of the virus interaction occurs near the acetylcholine binding site on the receptor. These findings support the hypothesis that the acetylcholine receptor may serve as a rabies virus receptor in vivo.

  9. Secretin receptor oligomers form intracellularly during maturation through receptor core domains.

    PubMed

    Lisenbee, Cayle S; Miller, Laurence J

    2006-07-11

    Oligomerization of numerous G protein-coupled receptors has been documented, including the prototypic family B secretin receptor. The clinical significance of oligomerization of this receptor became clear with the recent observation that a misspliced form present in pancreatic cancer could associate with the wild-type receptor and act as a dominant negative inhibitor of its normal growth inhibitory function. Our goal was to explore the molecular mechanism of this interaction using bioluminescence (BRET) and fluorescence (FRET) resonance energy transfer and fluorescence microscopy with a variety of receptor constructs tagged with luciferase or cyan or yellow fluorescent proteins. BRET signals comparable to those obtained from cells coexpressing differentially tagged wild-type receptors were observed for similarly tagged secretin receptors in which all or part of the amino-terminal domain was deleted. As expected, neither of these constructs bound secretin, and only the partially truncated construct sorted to the plasma membrane. Receptors lacking the majority of the carboxyl-terminal domain, including that important for phosphorylation-mediated desensitization, also produced BRET signals above background. These findings suggested that the receptor's membrane-spanning core is responsible for secretin receptor oligomerization. Interestingly, alanine substitutions for a -GxxxG- helix interaction motif in transmembrane segment 7 created nonfunctional receptors that were capable of forming oligomers. Furthermore, treatment of receptor-expressing cells with brefeldin A did not eliminate the BRET signals, and morphologic FRET experiments confirmed the expected subcellular localizations of receptor oligomers. We conclude that secretin receptor oligomerization occurs through -GxxxG- motif-independent interactions of transmembrane segments during the maturation of nascent molecules.

  10. The characteristics of gas hydrates occurring in natural environment

    NASA Astrophysics Data System (ADS)

    Lu, H.; Moudrakovski, I.; Udachin, K.; Enright, G.; Ratcliffe, C.; Ripmeester, J.

    2009-12-01

    In the past few years, extensive analyses have been carried out for characterizing the natural gas hydrate samples from Cascadia, offshore Vancouver Island; Mallik, Mackenzie Delta; Mount Elbert, Alaska North Slope; Nankai Trough, offshore Japan; Japan Sea and offshore India. With the results obtained, it is possible to give a general picture of the characteristics of gas hydrates occurring in natural environment. Gas hydrate can occur in sediments of various types, from sands to clay, although it is preferentially enriched in sediments of certain types, for example coarse sands and fine volcanic ash. Most of the gas hydrates in sediments are invisible, occurring in the pores of the sediments, while some hydrates are visible, appearing as massive, nodular, planar, vein-like forms and occurring around the seafloor, in the fractures related to fault systems, or any other large spaces available in sediments. Although methane is the main component of most of the natural gas hydrates, C2 to C7 hydrocarbons have been recognized in hydrates, sometimes even in significant amounts. Shallow marine gas hydrates have been found generally to contain minor amounts of hydrogen sulfide. Gas hydrate samples with complex gas compositions have been found to have heterogeneous distributions in composition, which might reflect changes in the composition of the available gas in the surrounding environment. Depending on the gas compositions, the structure type of a natural gas hydrate can be structure I, II or H. For structure I methane hydrate, the large cages are almost fully occupied by methane molecules, while the small cages are only partly occupied. Methane hydrates occurring in different environments have been identified with almost the same crystallographic parameters.

  11. Mineralogical Characteristics of Carbonate Rock-Hosted Naturally Occurring Asbestos

    NASA Astrophysics Data System (ADS)

    Shin, E.; Roh, Y.

    2012-12-01

    Naturally Occurring Asbestos (NOA) occurs in rocks and soils as a result of natural weathering and human activities. The parent rocks of asbestos have been associated with ultramafic and mafic rocks, and carbonate rock. The previous studies on naturally occurring asbestos were mainly limited to ultramafic and mafic rock-hosted asbestos and studies on carbonate rock-hosted asbestos are relatively rare in South Korea. Therefore, this study was aimed to characterize mineralogy of carbonate rock-hosted NOA at Muju and Jangsu, Jeonbuk province and Seosan and Asan, Chungnam province. The rock types at the four sites are consisting mainly of Precambrian metasedimentary rock. XRD and PLM analyses showed fibrous minerals in the sites were tremolite and actinolite of acicular and columnar forms. SEM-EDS analyses showed that asbestiform tremolite and actinolite had various ratios of length and diameters over 12:1, and needle and columnar forms. A columnar forms of tremolite and actinolite were showed small acicular at the edge of the particle. Its main chemical compositions are mainly Si, O, Mg, Ca, which were identical to tremolite. Actinolite contains Fe in addition to Si, O, Mg, Ca. EPMA analyses of asbestos occurred at Muju indicated that chemical composition are 55% SiO2, 23.2% MgO, 13.1 % CaO, and 0.61 % FeO and the chemical formula calculated as (K0.01Na0.01)Ca2.01(Mg4.94Fe0.05) (Al0.004Si7.98)O22(OH)2, which is close to ideal tremolite. In addition to tremolite, actinolite was also occurred at Seosan, Chungnam. XRD analyses showed that antigorite was existed at Muju, but PLM and SEM analyses showed the antigorite was platy structure, not asbestiform. These results indicate that asbestiform tremolite and actinolite with acicular forms contains in carbonate rocks at Muju and Jangsu, Jeonbuk and Seosan and Asan, Chungnam province South Korea.

  12. Complex high affinity interactions occur between MHCI and superantigens

    NASA Technical Reports Server (NTRS)

    Chapes, S. K.; Herpich, A. R.; Spooner, B. S. (Principal Investigator)

    1998-01-01

    Staphylococcal enterotoxins A and C1 (SEA or SEC1) bound to major histocompatibility-I (MHCI) molecules with high affinity (binding constants ranging from 1.1 microM to 79 nM). SEA and SEC1 directly bound MHCI molecules that had been captured by monoclonal antibodies specific for H-2Kk, H-2Dk, or both. In addition, MHCI-specific antibodies inhibited the binding of SEC1 to LM929 cells and SEA competitively inhibited SEC1 binding; indicating that the superantigens bound to MHCI on the cell surface. The affinity and number of superantigen binding sites differed depending on whether MHCI was expressed in the membrane of LM929 cells or whether it was captured. These data support the hypothesis that MHCI molecules can serve as superantigen receptors.

  13. Membrane insertion of anthrax protective antigen and cytoplasmic delivery of lethal factor occur at different stages of the endocytic pathway.

    PubMed

    Abrami, Laurence; Lindsay, Margaret; Parton, Robert G; Leppla, Stephen H; van der Goot, F Gisou

    2004-08-30

    The protective antigen (PA) of anthrax toxin binds to a cell surface receptor, undergoes heptamerization, and binds the enzymatic subunits, the lethal factor (LF) and the edema factor (EF). The resulting complex is then endocytosed. Via mechanisms that depend on the vacuolar ATPase and require membrane insertion of PA, LF and EF are ultimately delivered to the cytoplasm where their targets reside. Here, we show that membrane insertion of PA already occurs in early endosomes, possibly only in the multivesicular regions, but that subsequent delivery of LF to the cytoplasm occurs preferentially later in the endocytic pathway and relies on the dynamics of internal vesicles of multivesicular late endosomes.

  14. Characterisation of a household norovirus outbreak occurred in Valencia (Spain).

    PubMed

    Carmona-Vicente, Noelia; Fernández-Jiménez, Manuel; Vila-Vicent, Susana; Rodríguez-Díaz, Jesús; Buesa, Javier

    2016-03-12

    Human noroviruses (NoVs) are the main cause of non-bacterial gastroenteritis worldwide. Several studies have linked human susceptibility to NoVs with the expression of histo-blood group antigens (HBGAs). In January 2012, a NoV gastroenteritis outbreak affected a household in Valencia, Spain, and the personal susceptibility to NoV was investigated. To reach this aim 8 members of the affected household were recruited for this study and their secretor status, ABO and Lewis antigens were determined. NoV-specific saliva IgA and serum IgG antibody titers were analyzed. Their capacity to block viral binding to saliva receptors was analyzed, using virus-like particles (VLPs) of the NoV GII.4 genotype, 2006b variant, and saliva from a secretor O blood type donor. The most relevant finding was that an asymptomatic non-secretor individual shed NoVs in his stools. Interestingly, anti-NoV IgA antibody titers in saliva from secretor and non-secretor individuals showed no differences. On the contrary, high titers of NoV-specific IgG antibody were found in both convalescent sera and in sera collected 1 year post-infection, but only from secretor individuals. NoV GII.4-2006b VLP binding to receptors present in the saliva was efficiently blocked only by sera from secretor positive individuals. Despite the small number of individuals involved in this outbreak, this study reinforces the idea that susceptibility to human NoV is both dependent on the HBGA profile of the individuals as well as on the viral genotype and variant. We also show that the immunity to NoV lasts for at least 1 year after infection, demonstrating that symptomatic infections strongly stimulate immune responses.

  15. Erythropoietin's inhibiting impact on hepcidin expression occurs indirectly.

    PubMed

    Gammella, Elena; Diaz, Victor; Recalcati, Stefania; Buratti, Paolo; Samaja, Michele; Dey, Soumyadeep; Noguchi, Constance Tom; Gassmann, Max; Cairo, Gaetano

    2015-02-15

    Under conditions of accelerated erythropoiesis, elevated erythropoietin (Epo) levels are associated with inhibition of hepcidin synthesis, a response that ultimately increases iron availability to meet the enhanced iron needs of erythropoietic cells. In the search for erythroid regulators of hepcidin, many candidates have been proposed, including Epo itself. We aimed to test whether direct interaction between Epo and the liver is required to regulate hepcidin. We found that prolonged administration of high doses of Epo in mice leads to great inhibition of liver hepcidin mRNA levels, and concomitant induction of the hepcidin inhibitor erythroferrone (ERFE). Epo treatment also resulted in liver iron mobilization, mediated by increased ferroportin activity and accompanied by reduced ferritin levels and increased TfR1 expression. The same inhibitory effect was observed in mice that do not express the homodimeric Epo receptor (EpoR) in liver cells because EpoR expression is restricted to erythroid cells. Similarly, liver signaling pathways involved in hepcidin regulation were not influenced by the presence or absence of hepatic EpoR. Moreover, Epo analogs, possibly interacting with the postulated heterodimeric β common EpoR, did not affect hepcidin expression. These findings were supported by the lack of inhibition on hepcidin found in hepatoma cells exposed to various concentrations of Epo for different periods of times. Our results demonstrate that hepcidin suppression does not require the direct binding of Epo to its liver receptors and rather suggest that the role of Epo is to stimulate the synthesis of the erythroid regulator ERFE in erythroblasts, which ultimately downregulates hepcidin.

  16. Breast cancer surface receptors predict risk for developing brain metastasis and subsequent prognosis

    PubMed Central

    Grewal, Jai; Kesari, Santosh

    2008-01-01

    Determining the status of breast cancer surface receptors (estrogen receptor, progesterone receptor, HER2/neu) has become routine in the care of patients with this disease and has proven to be helpful in guiding treatment. For this reason, breast cancer has become a model for molecularly guided therapy in solid tumors. Emerging data support that these receptors are associated with risk for developing brain metastases. Additionally, once brain metastases have occurred these receptors may also correlate with prognosis. PMID:18373884

  17. Naturally occurring tumours in the basal metazoan Hydra.

    PubMed

    Domazet-Lošo, Tomislav; Klimovich, Alexander; Anokhin, Boris; Anton-Erxleben, Friederike; Hamm, Mailin J; Lange, Christina; Bosch, Thomas C G

    2014-06-24

    The molecular nature of tumours is well studied in vertebrates, although their evolutionary origin remains unknown. In particular, there is no evidence for naturally occurring tumours in pre-bilaterian animals, such as sponges and cnidarians. This is somewhat surprising given that recent computational studies have predicted that most metazoans might be prone to develop tumours. Here we provide first evidence for naturally occurring tumours in two species of Hydra. Histological, cellular and molecular data reveal that these tumours are transplantable and might originate by differentiation arrest of female gametes. Growth of tumour cells is independent from the cellular environment. Tumour-bearing polyps have significantly reduced fitness. In addition, Hydra tumours show a greatly altered transcriptome that mimics expression shifts in vertebrate cancers. Therefore, this study shows that spontaneous tumours have deep evolutionary roots and that early branching animals may be informative in revealing the fundamental mechanisms of tumorigenesis.

  18. The Natural Occurring Compounds Targeting Endoplasmic Reticulum Stress

    PubMed Central

    Liu, Hai; Yang, Jianqiong; Li, Linfu; Shi, Weimei

    2016-01-01

    ER stress has been implicated in pathophysiological development of many diseases. Persistent overwhelming stimuli trigger ER stress to initiate apoptosis, autophagy, and cell death. IRE1-JNK and eIF2α-CHOP signaling pathways are the two important players of ER stress, which is also modulated by ROS production, calcium disturbance, and inflammatory factors. ER stress has been developed as a novel strategy for diseases management. Recently, a vast of research focuses on the natural occurring compounds targeting ER stress, which results in medical benefits to human diseases. These small reported molecules mainly include polyphenols, alkaloids, and saponins. Many of them have been developed for use in clinical applications. To better understand the pharmacological mechanism of these molecules in ER stress in diseases, efforts have been made to discover and deliver medical merits. In this paper, we will summarize the natural occurring compounds targeting ER stress. PMID:27563337

  19. Issues related to regulatory control of naturally occurring radioactive materials

    SciTech Connect

    Chen, S.Y.

    1997-04-01

    Nearly 80% of human radiation exposure is from naturally occurring radioactive materials (NORM). While exposure from man-made sources of radiation has been well regulated, no consistent regulatory controls exist for NORM. Because elevated radiation levels have resulted from NORM enhancement activities such as occur in the petroleum, fertilizer, mining, and processing industries, some form of regulatory control is in order. In the US, regulation of NORM by federal agencies such as the Nuclear Regulatory Commission or the Environmental Protection Agency is not anticipated in the near future because there are no authorizing federal statutes. Important issues for addressing the control of NORM include source characterization and generation, radiation protection concerns, waste management and disposition, and the regulatory framework.

  20. [Pathologic characteristics of malignant neoplasms occurring in the elderly].

    PubMed

    Arai, Tomio; Matsuda, Yoko; Aida, Junko; Takubo, Kaiyo

    2015-08-01

    Malignant neoplasm preferentially occurs in the elderly. Common cancers in the elderly are gastric, colorectal, lung and prostate cancers in men whereas colorectal, lung, gastric and pancreatic cancers in women. There are several characteristic features such as tumor location, histology, biological behavior and pathway of carcinogenesis in malignant neoplasms occurring in the elderly. Multiple cancers increase with aging. Although it is generally believed that carcinoma in the elderly shows well differentiation, slow growth, low incidence of metastasis and favorable prognosis, the tumor does not always show such features. Regarding biological behavior of malignant tumor in the elderly, age-related alterations of the host such as stromal weakness and decreased immune response against cancer cell invasion should be considered as well as characteristics of tumor cell itself. Thus, we need a specific strategy for treatment for malignant neoplasms in the elderly.

  1. Serpentine ore microtextures occurring in the magnola magnesium process

    NASA Astrophysics Data System (ADS)

    Chen, T. T.; Dutrizac, J. E.; White, Carl

    2000-04-01

    Serpentine ore was leached at 95°C and 100°C in 7.0 M HCl media to study the reactions occurring in Noranda’s Magnola magnesium process. Magnesium leaches rapidly from the serpentine Mg3Si2O5(OH)4, and the silicon remains in-situ as an amorphous silica pseudomorph after the original serpentine particles. Negligible silica dissolution occurs, and silica gelation was never observed. The reaction interface extends over 300 400 µm; as a consequence, fine grinding does not significantly accelerate the rate of magnesium dissolution. Associated inclusions of brucite Mg(OH)2, awaruite Ni8Fe3, and magnetite Fe3O4 dissolve rapidly; whereas, chromite FeCr2O4 and a chromium-rich spinel (Cr,Fe,Al,Mg)3O4 remain largely unaffected.

  2. Naturally Occurring Animal Models with Outer Retina Phenotypes

    PubMed Central

    Baehr, Wolfgang; Frederick, Jeanne M.

    2009-01-01

    Naturally occurring and laboratory generated animal models serve as powerful tools with which to investigate the etiology of human retinal degenerations, especially retinitis pigmentosa (RP), Leber congenital amaurosis (LCA), cone dystrophies (CD) and macular degeneration (MD). Much progress has been made in elucidating gene defects underlying disease, in understanding mechanisms leading to disease, and in designing molecules for translational research and gene-based therapy to interfere with the progression of disease. Key to this progress has been study of naturally occurring murine and canine retinal degeneration mutants. This article will review the history, phenotypes and gene defects of select animal models with outer retina (photoreceptor and retinal pigment epithelium) degeneration phenotypes. PMID:19375447

  3. Snapthrough occurring in the postbuckling of thin films

    NASA Astrophysics Data System (ADS)

    Parry, G.; Colin, J.; Coupeau, C.; Foucher, F.; Cimetière, A.; Grilhé, J.

    2005-02-01

    The postbuckling transition from an initially straight-sided wrinkle to a distribution of bubbles has been investigated by means of finite element simulations in the case of a thin film relying on a rigid substrate. The calculations show that a snapthrough occurs when the buckling wavelength exceeds a critical value. Experimental atomic force microscopy observations of this transition have been reported and found to be in good agreement with the calculations.

  4. Co-occurring depression and pain in multiple sclerosis.

    PubMed

    Alschuler, Kevin N; Ehde, Dawn M; Jensen, Mark P

    2013-11-01

    Depression and pain are highly prevalent among individuals with multiple sclerosis, and they often co-occur. The purpose of this article is to summarize the literature and theory related to the comorbidity of pain and depression and describe how their presence can impact individuals with multiple sclerosis. Additionally, the article discusses how existing treatments of pain and depression could be adapted to address shared mechanisms and overcome barriers to treatment utilization.

  5. Sensory-motor transformations for speech occur bilaterally.

    PubMed

    Cogan, Gregory B; Thesen, Thomas; Carlson, Chad; Doyle, Werner; Devinsky, Orrin; Pesaran, Bijan

    2014-03-06

    Historically, the study of speech processing has emphasized a strong link between auditory perceptual input and motor production output. A kind of 'parity' is essential, as both perception- and production-based representations must form a unified interface to facilitate access to higher-order language processes such as syntax and semantics, believed to be computed in the dominant, typically left hemisphere. Although various theories have been proposed to unite perception and production, the underlying neural mechanisms are unclear. Early models of speech and language processing proposed that perceptual processing occurred in the left posterior superior temporal gyrus (Wernicke's area) and motor production processes occurred in the left inferior frontal gyrus (Broca's area). Sensory activity was proposed to link to production activity through connecting fibre tracts, forming the left lateralized speech sensory-motor system. Although recent evidence indicates that speech perception occurs bilaterally, prevailing models maintain that the speech sensory-motor system is left lateralized and facilitates the transformation from sensory-based auditory representations to motor-based production representations. However, evidence for the lateralized computation of sensory-motor speech transformations is indirect and primarily comes from stroke patients that have speech repetition deficits (conduction aphasia) and studies using covert speech and haemodynamic functional imaging. Whether the speech sensory-motor system is lateralized, like higher-order language processes, or bilateral, like speech perception, is controversial. Here we use direct neural recordings in subjects performing sensory-motor tasks involving overt speech production to show that sensory-motor transformations occur bilaterally. We demonstrate that electrodes over bilateral inferior frontal, inferior parietal, superior temporal, premotor and somatosensory cortices exhibit robust sensory-motor neural

  6. [A solitary ganglioneuroma occurring in the sigmoid colon].

    PubMed

    Rabjerg, Maj; Kolodziejczyk, Adam

    2012-09-24

    We report a case of a rare solitary ganglioneuroma occurring in the sigmoid colon of a 70-year-old woman. She experienced sudden onset of abdominal pain and loss of old blood from the gastrointestinal tract. A colonoscopy disclosed a pedunculate polyp in the sigmoid colon 20 cm from the anus, and a histopathologic examination revealed a polypoid mucosa with abundant ganglionic cells and nerve fibres.

  7. Myelodysplastic Syndrome Occurring in a Patient with Gorlin Syndrome.

    PubMed

    Mull, Jamie L; Madden, Lisa M; Bayliss, Susan J

    2016-07-01

    We report a case of myelodysplastic syndrome (MDS) occurring in an African American boy with Gorlin syndrome with a novel PTCH1 mutation. Before developing MDS, the patient had been treated with chemotherapy and radiation for a medulloblastoma. He received a bone marrow transplant for the MDS and eventually died of treatment complications. Secondary hematologic malignancies are a known complication of certain chemotherapeutics, although whether a patient with Gorlin syndrome has a greater propensity for the development of such malignancies is unclear.

  8. Ticks of Medical Importance Occurring in the Western Hemisphere

    DTIC Science & Technology

    1987-10-01

    disease agents such as protozoa, viruses , bacteria, rickettsiae and toxins. Ticks may also cause Irritation and discomfnrt directly as a result of their...the virus . BabEsiosis Human babesiosis is a malaria-like disease of varying severity which becomes clinically apparent I to 4 weeks after exposure. The...Panama, Colombia , Venezuela, and Ecuador (8). Distribution: This species (Figs. 7, 8) occurs in Panama (10), Paraguay, Colombia (3), Venezuela ,11

  9. When can inverted water tables occur beneath streams?

    PubMed

    Xie, Yueqing; Cook, Peter G; Brunner, Philip; Irvine, Dylan J; Simmons, Craig T

    2014-01-01

    Decline in regional water tables (RWT) can cause losing streams to disconnect from underlying aquifers. When this occurs, an inverted water table (IWT) will develop beneath the stream, and an unsaturated zone will be present between the IWT and the RWT. The IWT marks the base of the saturated zone beneath the stream. Although a few prior studies have suggested the likelihood of an IWT without a clogging layer, most of them have assumed that a low-permeability streambed is required to reduce infiltration from surface water to groundwater, and that the IWT only occurs at the bottom of the low-permeability layer. In this study, we use numerical simulations to show that the development of an IWT beneath an unclogged stream is theoretically possible under steady-state conditions. For a stream width of 1 m above a homogeneous and isotropic sand aquifer with a 47 m deep RWT (measured in an observation point 20 m away from the center of the stream), an IWT will occur provided that the stream depth is less than a critical value of 4.1 m. This critical stream depth is the maximum water depth in the stream to maintain the occurrence of an IWT. The critical stream depth decreases with stream width. For a stream width of 6 m, the critical stream depth is only 1 mm. Thus while theoretically possible, an IWT is unlikely to occur at steady state without a clogging layer, unless a stream is very narrow or shallow and the RWT is very deep.

  10. Cocaine disrupts histamine H3 receptor modulation of dopamine D1 receptor signaling: σ1-D1-H3 receptor complexes as key targets for reducing cocaine's effects.

    PubMed

    Moreno, Estefanía; Moreno-Delgado, David; Navarro, Gemma; Hoffmann, Hanne M; Fuentes, Silvia; Rosell-Vilar, Santi; Gasperini, Paola; Rodríguez-Ruiz, Mar; Medrano, Mireia; Mallol, Josefa; Cortés, Antoni; Casadó, Vicent; Lluís, Carme; Ferré, Sergi; Ortiz, Jordi; Canela, Enric; McCormick, Peter J

    2014-03-05

    The general effects of cocaine are not well understood at the molecular level. What is known is that the dopamine D1 receptor plays an important role. Here we show that a key mechanism may be cocaine's blockade of the histamine H3 receptor-mediated inhibition of D1 receptor function. This blockade requires the σ1 receptor and occurs upon cocaine binding to σ1-D1-H3 receptor complexes. The cocaine-mediated disruption leaves an uninhibited D1 receptor that activates Gs, freely recruits β-arrestin, increases p-ERK 1/2 levels, and induces cell death when over activated. Using in vitro assays with transfected cells and in ex vivo experiments using both rats acutely treated or self-administered with cocaine along with mice depleted of σ1 receptor, we show that blockade of σ1 receptor by an antagonist restores the protective H3 receptor-mediated brake on D1 receptor signaling and prevents the cell death from elevated D1 receptor signaling. These findings suggest that a combination therapy of σ1R antagonists with H3 receptor agonists could serve to reduce some effects of cocaine.

  11. Evolution of virulence when transmission occurs before disease.

    PubMed

    Osnas, Erik E; Dobson, Andrew P

    2010-08-23

    Most models of virulence evolution assume that transmission and virulence are constant during an infection. In many viral (HIV and influenza), bacterial (TB) and prion (BSE and CWD) systems, disease-induced mortality occurs long after the host becomes infectious. Therefore, we constructed a model with two infected classes that differ in transmission rate and virulence in order to understand how the evolutionarily stable strategy (ESS) depends on the relative difference in transmission and virulence between classes, on the transition rate between classes and on the recovery rate from the second class. We find that ESS virulence decreases when expressed early in the infection or when transmission occurs late in an infection. When virulence occurred relatively equally in each class and there was disease recovery, ESS virulence increased with increased transition rate. In contrast, ESS virulence first increased and then decreased with transition rate when there was little virulence early in the infection and a rapid recovery rate. This model predicts that ESS virulence is highly dependent on the timing of transmission and pathology after infection; thus, pathogen evolution may either increase or decrease virulence after emergence in a new host.

  12. A novel trauma model: naturally occurring canine trauma.

    PubMed

    Hall, Kelly E; Sharp, Claire R; Adams, Cynthia R; Beilman, Gregory

    2014-01-01

    In human trauma patients, most deaths result from hemorrhage and brain injury, whereas late deaths, although rare, are the result of multiple organ failure and sepsis. A variety of experimental animal models have been developed to investigate the pathophysiology of traumatic injury and evaluate novel interventions. Similar to other experimental models, these trauma models cannot recapitulate conditions of naturally occurring trauma, and therefore therapeutic interventions based on these models are often ineffective. Pet dogs with naturally occurring traumatic injury represent a promising translational model for human trauma that could be used to assess novel therapies. The purpose of this article was to review the naturally occurring canine trauma literature to highlight the similarities between canine and human trauma. The American College of Veterinary Emergency and Critical Care Veterinary Committee on Trauma has initiated the establishment of a national network of veterinary trauma centers to enhance uniform delivery of care to canine trauma patients. In addition, the Spontaneous Trauma in Animals Team, a multidisciplinary, multicenter group of researchers has created a clinical research infrastructure for carrying out large-scale clinical trials in canine trauma patients. Moving forward, these national resources can be utilized to facilitate multicenter prospective studies of canine trauma to evaluate therapies and interventions that have shown promise in experimental animal models, thus closing the critical gap in the translation of knowledge from experimental models to humans and increasing the likelihood of success in phases 1 and 2 human clinical trials.

  13. Pharmacotherapy of Co-Occurring Schizophrenia and Substance Use Disorders

    PubMed Central

    Akerman, Sarah C.; Brunette, Mary F.; Noordsy, Douglas L.

    2016-01-01

    Substance use disorders, common in patients with schizophrenia, can lead to poor outcomes. Here we review the literature on the use of antipsychotics in patients with co-occurring schizophrenia and substance use disorder as well as evidence for the use of adjunctive pharmacological treatments targeting substance use in these patients. We also discuss a neurobiological formulation suggesting that the cooccurrence of these disorders may be related to a dysfunction in the dopamine mediated brain reward circuitry. Typical antipsychotics do not appear to decrease substance use in this population. Randomized, controlled trials provide some support for use of the atypical antipsychotic clozapine for co-occurring cannabis use disorder, naltrexone and disulfiram for alcohol use disorder, and also nicotine replacement therapy, sustained-release bupropion and varenicline for tobacco use disorder. Nonetheless, data regarding treatment in patients with these co-occurring disorders are still limited, and many studies reported to date have been either underpowered or did not include a control condition. Further research is needed to evaluate optimal pharmacotherapeutic strategies for this population. PMID:27226947

  14. Naturally Occurring Anthraquinones: Chemistry and Therapeutic Potential in Autoimmune Diabetes

    PubMed Central

    Wu, Yueh-Chen

    2015-01-01

    Anthraquinones are a class of aromatic compounds with a 9,10-dioxoanthracene core. So far, 79 naturally occurring anthraquinones have been identified which include emodin, physcion, cascarin, catenarin, and rhein. A large body of literature has demonstrated that the naturally occurring anthraquinones possess a broad spectrum of bioactivities, such as cathartic, anticancer, anti-inflammatory, antimicrobial, diuretic, vasorelaxing, and phytoestrogen activities, suggesting their possible clinical application in many diseases. Despite the advances that have been made in understanding the chemistry and biology of the anthraquinones in recent years, research into their mechanisms of action and therapeutic potential in autoimmune disorders is still at an early stage. In this paper, we briefly introduce the etiology of autoimmune diabetes, an autoimmune disorder that affects as many as 10 million worldwide, and the role of chemotaxis in autoimmune diabetes. We then outline the chemical structure and biological properties of the naturally occurring anthraquinones and their derivatives with an emphasis on recent findings about their immune regulation. We discuss the structure and activity relationship, mode of action, and therapeutic potential of the anthraquinones in autoimmune diabetes, including a new strategy for the use of the anthraquinones in autoimmune diabetes. PMID:25866536

  15. Skin picking disorder with co-occurring body dysmorphic disorder.

    PubMed

    Grant, Jon E; Redden, Sarah A; Leppink, Eric W; Odlaug, Brian L

    2015-09-01

    There is clinical overlap between skin picking disorder (SPD) and body dysmorphic disorder (BDD), but little research has examined clinical and cognitive correlates of the two disorders when they co-occur. Of 55 participants with SPD recruited for a neurocognitive study and two pharmacological studies, 16 (29.1%) had co-occurring BDD. SPD participants with and without BDD were compared to each other and to 40 healthy volunteers on measures of symptom severity, social functioning, and cognitive assessments using the Stop-signal task (assessing response impulsivity) and the Intra-dimensional/Extra-dimensional Set Shift task (assessing cognitive flexibility). Individuals with SPD and BDD exhibited significantly worse picking, significantly worse overall psychosocial functioning, and significantly greater dysfunction on aspects of cognitive flexibility. These results indicate that when SPD co-occurs with BDD unique clinical and cognitive aspects of SPD may be more pronounced. Future work should explore possible subgroups in SPD and whether these predict different treatment outcomes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Prediction of human voluntary movement before it occurs

    PubMed Central

    Bai, Ou; Rathi, Varun; Lin, Peter; Huang, Dandan; Battapady, Harsha; Fei, Ding-Yu; Schneider, Logan; Houdayer, Elise; Chen, Xuedong; Hallett, Mark

    2017-01-01

    Objective Human voluntary movement is associated with two changes in electroencephalography (EEG) that can be observed as early as 1.5 s prior to movement: slow DC potentials and frequency power shifts in the alpha and beta bands. Our goal was to determine whether and when we can reliably predict human natural movement BEFORE it occurs from EEG signals ONLINE IN REAL-TIME. Methods We developed a computational algorithm to support online prediction. Seven healthy volunteers participated in this study and performed wrist extensions at their own pace. Results The average online prediction time was 0.62 ± 0.25 s before actual movement monitored by EMG signals. There were also predictions that occurred without subsequent actual movements, where subjects often reported that they were thinking about making a movement. Conclusion Human voluntary movement can be predicted before movement occurs. Significance The successful prediction of human movement intention will provide further insight into how the brain prepares for movement, as well as the potential for direct cortical control of a device which may be faster than normal physical control. PMID:20675187

  17. Clinical experience of esophageal perforation occurring with endoscopic submucosal dissection.

    PubMed

    Sato, H; Inoue, H; Ikeda, H; Grace R Santi, E; Yoshida, A; Onimaru, M; Kudo, S

    2014-01-01

    Esophageal perforation occurring during or after endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) is a rare, but serious complication. However, reports of its characteristics, including endoscopic imaging and management, have not been fully detailed. To analyze and report the clinical presentation and management of esophageal perforations occurred during or after EMR/ESD. Four hundred seventy-two esophageal neoplasms in 368 patients were treated (171 EMR; ESD 306) at Northern Yokohama Hospital from 2003 to 2012. Esophageal perforation occurred in a total of seven (1.9%) patients, all of whom were male and had undergone ESD. The etiology of perforation was: three (42.9%) intraoperative; three (42.9%) balloon dilatation for stricture prevention; one (14.2%) due to food bolus impaction. All cases were managed non-operatively based on the comprehensive assessment of clinical severity, extent of the injury, and the time interval from perforation to treatment onset. Conservative management included (i) bed rest and continuous monitoring to determine the need for operative intervention; (ii) fasting and intravenous fluid infusion/ tube feeding; and (iii) intravenous antibiotics. All defects closed spontaneously, save one case where closure was achieved by endoscopic clipping. Surgery was not required. Conservative management for esophageal perforation during advanced endoscopic resection is may be possible when there is no delay in diagnosis or treatment. Decision-making should be governed purely by multidisciplinary discussion.

  18. SNPs occur in regions with less genomic sequence conservation.

    PubMed

    Castle, John C

    2011-01-01

    Rates of SNPs (single nucleotide polymorphisms) and cross-species genomic sequence conservation reflect intra- and inter-species variation, respectively. Here, I report SNP rates and genomic sequence conservation adjacent to mRNA processing regions and show that, as expected, more SNPs occur in less conserved regions and that functional regions have fewer SNPs. Results are confirmed using both mouse and human data. Regions include protein start codons, 3' splice sites, 5' splice sites, protein stop codons, predicted miRNA binding sites, and polyadenylation sites. Throughout, SNP rates are lower and conservation is higher at regulatory sites. Within coding regions, SNP rates are highest and conservation is lowest at codon position three and the fewest SNPs are found at codon position two, reflecting codon degeneracy for amino acid encoding. Exon splice sites show high conservation and very low SNP rates, reflecting both splicing signals and protein coding. Relaxed constraint on the codon third position is dramatically seen when separating exonic SNP rates based on intron phase. At polyadenylation sites, a peak of conservation and low SNP rate occurs from 30 to 17 nt preceding the site. This region is highly enriched for the sequence AAUAAA, reflecting the location of the conserved polyA signal. miRNA 3' UTR target sites are predicted incorporating interspecies genomic sequence conservation; SNP rates are low in these sites, again showing fewer SNPs in conserved regions. Together, these results confirm that SNPs, reflecting recent genetic variation, occur more frequently in regions with less evolutionarily conservation.

  19. Tardive dyskinesia occurring in a young woman after withdrawal of an atypical antipsychotic drug

    PubMed Central

    Alblowi, Mohammed A.; Alosaimi, Fahad D.

    2015-01-01

    Tardive dyskinesia (TD) is one of the most serious and disturbing side-effects of dopamine receptor antagonists. It affects 20-50% of patients on long-term antipsychotic therapy. The pathophysiology of TD remains poorly understood, and treatment is often challenging. Here, we present a 32-year-old woman presenting with a 9-month history of TD occurring after risperidone withdrawal, and characterized almost exclusively by tongue protrusion. After being seen by different specialties and undergoing multiple investigations, she was eventually correctly diagnosed with TD by a specialist team and successfully treated with amantadine. Vigilance and awareness of this condition and its risk factors are required to make the correct diagnosis, especially in cases with unusual presentations caused by atypical antipsychotics, and treatment can be challenging. PMID:26492119

  20. Oxytocin neuron activation prevents hypertension that occurs with chronic intermittent hypoxia/hypercapnia in rats.

    PubMed

    Jameson, Heather; Bateman, Ryan; Byrne, Peter; Dyavanapalli, Jhansi; Wang, Xin; Jain, Vivek; Mendelowitz, David

    2016-06-01

    Hypertension is a common outcome associated with obstructive sleep apnea (OSA), a prevalent yet poorly treated cardiovascular disease. Recent studies showed oxytocin (OXT), released from hypothalamic paraventricular nucleus (PVN) neurons, activates cardiac vagal neurons in the dorsal motor nucleus of the vagus (DMNX) and may blunt cardiovascular responses to stress. This study tests whether the release of OXT from PVN fibers in the DMNX is diminished with chronic intermittent hypoxia-hypercapnia (CIH/H) exposure, an animal model of OSA, and whether activation of PVN OXT neurons restores OXT release in the DMNX and prevents the hypertension resulting from CIH/H. To assess OXT release from PVN fibers, Chinese hamster ovarian (CHO) cells were engineered to be highly sensitive to OXT by stable expression of the human recombinant OXT receptor and the calcium indicator R-GECO1. PVN fibers in the DMNX were selectively photoactivated in vitro by expression of channelrhodopsin. The release of OXT onto CHO cells in the DMNX was blunted in rats exposed to 21 days of CIH/H. Chronic activation of PVN OXT neurons in vivo, using designer receptors exclusively activated by designer drugs, restored the release of OXT onto CHO cells in the DMNX. Chronic PVN OXT neuron activation in vivo also prevented the hypertension that occurred in conscious unrestrained telemetry-equipped sham rats exposed to 3 wk of CIH/H. These results demonstrate that chronic activation of OXT neurons restores the release of OXT from PVN fibers in the DMNX and prevents the hypertension that occurs with 3 wk of CIH/H exposure. Copyright © 2016 the American Physiological Society.

  1. Receptor palmitoylation and ubiquitination regulate anthrax toxin endocytosis

    PubMed Central

    Abrami, Laurence; Leppla, Stephen H.; van der Goot, F. Gisou

    2006-01-01

    The anthrax toxin is composed of three independent polypeptide chains. Successful intoxication only occurs when heptamerization of the receptor-binding polypeptide, the protective antigen (PA), allows binding of the two enzymatic subunits before endocytosis. We show that this tailored behavior is caused by two counteracting posttranslational modifications in the cytoplasmic tail of PA receptors. The receptor is palmitoylated, and this unexpectedly prevents its association with lipid rafts and, thus, its premature ubiquitination. This second modification, which is mediated by the E3 ubiquitin ligase Cbl, only occurs in rafts and is required for rapid endocytosis of the receptor. As a consequence, cells expressing palmitoylation-defective mutant receptors are less sensitive to anthrax toxin because of a lower number of surface receptors as well as premature internalization of PA without a requirement for heptamerization. PMID:16401723

  2. Receptor palmitoylation and ubiquitination regulate anthrax toxin endocytosis.

    PubMed

    Abrami, Laurence; Leppla, Stephen H; van der Goot, F Gisou

    2006-01-16

    The anthrax toxin is composed of three independent polypeptide chains. Successful intoxication only occurs when heptamerization of the receptor-binding polypeptide, the protective antigen (PA), allows binding of the two enzymatic subunits before endocytosis. We show that this tailored behavior is caused by two counteracting posttranslational modifications in the cytoplasmic tail of PA receptors. The receptor is palmitoylated, and this unexpectedly prevents its association with lipid rafts and, thus, its premature ubiquitination. This second modification, which is mediated by the E3 ubiquitin ligase Cbl, only occurs in rafts and is required for rapid endocytosis of the receptor. As a consequence, cells expressing palmitoylation-defective mutant receptors are less sensitive to anthrax toxin because of a lower number of surface receptors as well as premature internalization of PA without a requirement for heptamerization.

  3. Transient asymptomatic pulmonary opacities occurring during osimertinib treatment

    PubMed Central

    Noonan, Sinead A.; Sachs, Peter B.; Camidge, D. Ross

    2017-01-01

    Introduction Osimertinib is an Epidermal Growth Factor Receptor (EGFR) Inhibitor licensed for the treatment of EGFR mutant, T790M positive, non-small cell lung cancer (NSCLC). Previously unreported, common, transient asymptomatic pulmonary opacities (TAPOs) were noted at the University of Colorado in patients during osimertinib therapy. Methods CT imaging and clinical notes of NSCLC patients treated at the University of Colorado with osimertinib were retrospectively reviewed. Results Seven of twenty patients (35%), developed TAPOs while on osimertinib. The radiological patterns seen included ground-glass opacities with/without nodular consolidation. The median time to first lesion development was 8.7 weeks (range: 1.6 – 43 weeks) and 6 weeks (range: 1 – 11 weeks) to resolution during continued osimertinib. Conclusions TAPOs may be a previously unrecognized, benign feature associated with osimertinib therapy, which may be mistaken for isolated pulmonary progression or the beginning of more severe pneumonitis. If new onset pulmonary lesions, especially those associated with ground-glass appearances, are asymptomatic, localized and there is no evidence of disease progression elsewhere it may be reasonable to continue treatment with osimertinib and monitor these lesions for resolution. PMID:27618759

  4. Naturally occurring disseminated group B streptococcus infections in postnatal rats.

    PubMed

    Shuster, Katherine A; Hish, Gerald A; Selles, Lindsi A; Chowdhury, Mahboob A; Wiggins, Roger C; Dysko, Robert C; Bergin, Ingrid L

    2013-02-01

    Group B Streptococcus (Streptococcus agalactiae, GBS) is a gram-positive commensal and occasional opportunistic pathogen of the human vaginal, respiratory, and intestinal tracts that can cause sepsis, pneumonia, or meningitis in human neonates, infants, and immunosuppressed persons. We report here on a spontaneous outbreak of postnatal GBS-associated disease in rats. Ten of 26 (38.5%) 21- to 24-d-old rat pups died or were euthanized due to a moribund state in a colony of rats transgenic for the human diphtheria toxin receptor on a Munich-Wistar-Frömter genetic background. Four pups had intralesional coccoid bacteria in various organs without accompanying inflammation. GBS was isolated from the liver of 2 of these pups and from skin abscesses in 3 littermates. A connection with the transgene could not be established. A treatment protocol was evaluated in the remaining breeding female rats. GBS is a potentially clinically significant spontaneous infection in various populations of research rats, with some features that resemble late-onset postnatal GBS infection in human infants.

  5. Hemostatic abnormalities in dogs with naturally occurring heatstroke.

    PubMed

    Bruchim, Yaron; Kelmer, Efrat; Cohen, Adar; Codner, Carolina; Segev, Gilad; Aroch, Itamar

    2017-05-01

    To investigate hemostatic analyte abnormalities and their association with mortality in dogs with naturally occurring heatstroke. Prospective observational study. University teaching hospital. Thirty client-owned dogs with naturally occurring heatstroke. None. Citrated and EDTA blood samples were collected at presentation and at 4, 12, 24, 36, and 48 hours postpresentation (PP). Hemostatic tests performed included platelet count, prothrombin and activated partial thromboplastin times (PT and aPTT, respectively), antithrombin activity (ATA), total protein C activity (tPCA), fibrinogen, and D-dimer concentrations. The overall survival rate was 60% (18/30 dogs). Older age, higher heart rate and rectal temperature at presentation, and time from onset of clinical signs to presentation were significantly associated with mortality. Hemostatic analytes at presentation were not associated with mortality. Prolonged PT and aPTT at 12-24 hours PP, lower tPCA at 12 hours PP, and hypofibrinogenemia at 24 hours PP were significantly (P < 0.05) associated with mortality. Increased D-dimer concentration and low ATA were common at all time points, but were not associated with mortality. The frequency of disseminated intravascular coagulation (DIC) increased in nonsurvivors throughout hospitalization, but the development of DIC was not associated with mortality. The number of abnormal coagulation disturbances during the first 24 hours was significantly higher in nonsurvivors (P = 0.04). Hemostatic derangements are common in dogs with naturally occurring heatstroke. Alterations in PT, aPTT, tPCA, and fibrinogen concentrations appear to be associated with the outcome at 12-24 hours PP, exemplifying the need for serial measurement of multiple laboratory hemostatic tests during hospitalization, even when within reference interval on presentation. The development of DIC, as defined in this cohort, was not associated with mortality; however, nonsurvivors had significantly more coagulation

  6. Leaching Properties of Naturally Occurring Heavy Metals from Soils

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Hoshino, M.; Yoshikawa, M.; Hara, J.; Sugita, H.

    2014-12-01

    The major threats to human health from heavy metals are associated with exposure to arsenic, lead, cadmium, chromium, mercury, as well as some other elements. The effects of such heavy metals on human health have been extensively studied and reviewed by international organizations such as WHO. Due to their toxicity, heavy metal contaminations have been regulated by national environmental standards in many countries, and/or laws such as the Soil Contamination Countermeasures Act in Japan. Leaching of naturally occurring heavy metals from the soils, especially those around abandoned metal mines into surrounding water systems, either groundwater or surface water systems, is one of the major pathways of exposure. Therefore, understanding the leaching properties of toxic heavy metals from naturally polluted soils is of fundamentally importance for effectively managing abandoned metal mines, excavated rocks discharged from infrastructure constructions such as tunneling, and/or selecting a pertinent countermeasure against pollution when it is necessary. In this study, soil samples taken from the surroundings of abandoned metal mines in different regions in Japan were collected and analyzed. The samples contained multiple heavy metals such as lead, arsenic and chromium. Standard leaching test and sequential leaching test considering different forms of contaminants, such as trivalent and pentavalent arsenics, and trivalent and hexavalent chromiums, together with standard test for evaluating total concentration, X-ray Fluorescence Analysis (XRF), X-ray diffraction analysis (XRD) and Cation Exchange Capacity (CEC) tests were performed. In addition, sequential leaching tests were performed to evaluate long-term leaching properties of lead from representative samples. This presentation introduces the details of the above experimental study, discusses the relationships among leaching properties and chemical and mineral compositions, indicates the difficulties associated with

  7. SNPs Occur in Regions with Less Genomic Sequence Conservation

    PubMed Central

    Castle, John C.

    2011-01-01

    Rates of SNPs (single nucleotide polymorphisms) and cross-species genomic sequence conservation reflect intra- and inter-species variation, respectively. Here, I report SNP rates and genomic sequence conservation adjacent to mRNA processing regions and show that, as expected, more SNPs occur in less conserved regions and that functional regions have fewer SNPs. Results are confirmed using both mouse and human data. Regions include protein start codons, 3′ splice sites, 5′ splice sites, protein stop codons, predicted miRNA binding sites, and polyadenylation sites. Throughout, SNP rates are lower and conservation is higher at regulatory sites. Within coding regions, SNP rates are highest and conservation is lowest at codon position three and the fewest SNPs are found at codon position two, reflecting codon degeneracy for amino acid encoding. Exon splice sites show high conservation and very low SNP rates, reflecting both splicing signals and protein coding. Relaxed constraint on the codon third position is dramatically seen when separating exonic SNP rates based on intron phase. At polyadenylation sites, a peak of conservation and low SNP rate occurs from 30 to 17 nt preceding the site. This region is highly enriched for the sequence AAUAAA, reflecting the location of the conserved polyA signal. miRNA 3′ UTR target sites are predicted incorporating interspecies genomic sequence conservation; SNP rates are low in these sites, again showing fewer SNPs in conserved regions. Together, these results confirm that SNPs, reflecting recent genetic variation, occur more frequently in regions with less evolutionarily conservation. PMID:21674007

  8. Most Retroviral Recombinations Occur during Minus-Strand DNA Synthesis

    PubMed Central

    Zhang, Jiayou; Tang, Ling-Yun; Li, Ting; Ma, Yan; Sapp, Christy M.

    2000-01-01

    Retroviral RNA molecules are plus, or sense in polarity, equivalent to mRNA. During reverse transcription, the first strand of the DNA molecule synthesized is minus-strand DNA. After the minus strand is polymerized, the plus-strand DNA is synthesized using the minus-strand DNA as the template. In this study, a helper cell line that contains two proviruses with two different mutated gfp genes was constructed. Recombination between the two frameshift mutant genes resulted in a functional gfp. If recombination occurs during minus-strand DNA synthesis, the plus-strand DNA will also contain the functional sequence. After the cell divides, all of its offspring will be green. However, if recombination occurs during plus-strand DNA synthesis, then only the plus-strand DNA will contain the wild-type gfp sequence and the minus-strand DNA will still carry the frameshift mutation. The double-stranded DNA containing this mismatch was subsequently integrated into the host chromosomal DNA of D17 cells, which were unable to repair the majority of mismatches within the retroviral double-strand DNA. After the cell divided, one daughter cell contained the wild-type gfp sequence and the other daughter cell contained the frameshift mutation in the gfp sequence. Under fluorescence microscopy, half the cells in the offspring were green and the other half of the cells were colorless or clear. Thus, we demonstrated that more than 98%, if not all, retroviral recombinations occurred during minus-strand DNA synthesis. PMID:10666262

  9. Designing occupancy studies when false-positive detections occur

    USGS Publications Warehouse

    Clement, Matthew

    2016-01-01

    1.Recently, estimators have been developed to estimate occupancy probabilities when false-positive detections occur during presence-absence surveys. Some of these estimators combine different types of survey data to improve estimates of occupancy. With these estimators, there is a tradeoff between the number of sample units surveyed, and the number and type of surveys at each sample unit. Guidance on efficient design of studies when false positives occur is unavailable. 2.For a range of scenarios, I identified survey designs that minimized the mean square error of the estimate of occupancy. I considered an approach that uses one survey method and two observation states and an approach that uses two survey methods. For each approach, I used numerical methods to identify optimal survey designs when model assumptions were met and parameter values were correctly anticipated, when parameter values were not correctly anticipated, and when the assumption of no unmodelled detection heterogeneity was violated. 3.Under the approach with two observation states, false positive detections increased the number of recommended surveys, relative to standard occupancy models. If parameter values could not be anticipated, pessimism about detection probabilities avoided poor designs. Detection heterogeneity could require more or fewer repeat surveys, depending on parameter values. If model assumptions were met, the approach with two survey methods was inefficient. However, with poor anticipation of parameter values, with detection heterogeneity, or with removal sampling schemes, combining two survey methods could improve estimates of occupancy. 4.Ignoring false positives can yield biased parameter estimates, yet false positives greatly complicate the design of occupancy studies. Specific guidance for major types of false-positive occupancy models, and for two assumption violations common in field data, can conserve survey resources. This guidance can be used to design efficient

  10. Transmission of Naturally Occurring Lymphoma in Macaque Monkeys

    NASA Astrophysics Data System (ADS)

    Hunt, Ronald D.; Blake, Beverly J.; Chalifoux, Laura V.; Sehgal, Prabhat K.; King, Norval W.; Letvin, Norman L.

    1983-08-01

    Spontaneously occurring rhesus monkey lymphomas were transmitted into healthy rhesus monkeys by using tumor cell suspensions. The naturally arising tumors included an immunoblastic sarcoma and an undifferentiated lymphoma. Recipient animals developed undifferentiated lymphomas, poorly differentiated lymphomas, or parenchymal lymphoproliferative abnormalities suggestive of early lesions of lymphoma. Some of these animals developed such opportunistic infections as cytomegalovirus hepatitis and cryptosporidiosis. They also showed evidence of an abnormal circulating peripheral blood mononuclear cell. These findings, all characteristic of the acquired immune deficiency syndrome (AIDS) of macaques, suggest a link between these transmissible lymphomas and AIDS in macaque monkeys.

  11. Pseudo-Kaposi sarcoma (acroangiodermatitis): occurring after bullous erysipelas.

    PubMed

    Kutlubay, Zekayi; Yardimci, Gürkan; Engin, Burhan; Demirkesen, Cuyan; Aydin, Övgü; Khatib, Rashid; Tuzun, Yalçın

    2015-05-18

    Pseudo-Kaposi sarcoma is a benign reactive vascular proliferative disorder, which can be seen at any age. It occurs when the chronic venous pressure changes result in vascular proliferation in the upper and mid dermis. This disease is divided into two subtypes: the most frequent subtype is the Mali type and seen in early ages. The Mali type is seen in chronic venous insufficiency and in those patients with arteriovenous shunts. The rare subtype is the Stewart-Bluefarb type. This disease must be distinguished from Kaposi sarcoma because of their clinical resemblance. Herein, we present a patient with pseudo-Kaposi sarcoma, which developed after bullous erysipelas.

  12. Photoprotective substance occurs primarily in outer layers of fish skin

    USGS Publications Warehouse

    Fabacher, D.L.; Little, E.E.

    1998-01-01

    Methanol extracts of dorsal skin layers, eyes, gills, and livers from ultraviolet-B (UVB) radiation-sensitive and UVB-tolerant species of freshwater fish were examined for a substance that appears to be photoprotective. Significantly larger amounts of this substance were found in extracts of outer dorsal skin layers from both UVB-sensitive and UVB-tolerant fish when compared with extracts of inner dorsal skin layers. This substance occurred in minor amounts or was not detected in eye, gill, and liver extracts. The apparent primary function of this substance in fish is to protect the cells in outer dorsal skin layers from harmful levels of UVB radiation.

  13. Naturally occurring crystalline phases: analogues for radioactive waste forms

    SciTech Connect

    Haaker, R.F.; Ewing, R.C.

    1981-01-01

    Naturally occurring mineral analogues to crystalline phases that are constituents of crystalline radioactive waste forms provide a basis for comparison by which the long-term stability of these phases may be estimated. The crystal structures and the crystal chemistry of the following natural analogues are presented: baddeleyite, hematite, nepheline; pollucite, scheelite;sodalite, spinel, apatite, monazite, uraninite, hollandite-priderite, perovskite, and zirconolite. For each phase in geochemistry, occurrence, alteration and radiation effects are described. A selected bibliography for each phase is included.

  14. Naturally occurring anti-tissue antibodies in rat sera

    PubMed Central

    Weir, D. M.; Pinckard, R. N.; Elson, C. J.; Suckling, Deirdre E.

    1966-01-01

    Seventy per cent of normal rat sera have been shown to contain heat labile serum component(s) active against various rat organ homogenates as demonstrated by haemolytic complement fixation and passive haemagglutination tests. The main antigenic activity in rat liver has been found in the mitochondrial fractions. It was also demonstrated by the indirect fluorescent antibody technique that both guinea-pig complement and high molecular weight rat globulins were fixed to rat organ sections. Chemotactic activity has also been observed with rat serum and rat liver mitochondria and it is suggested that these naturally occurring antibodies may be implicated in the removal of tissue breakdown products. PMID:5338951

  15. Transmission of naturally occurring lymphoma in macaque monkeys.

    PubMed Central

    Hunt, R D; Blake, B J; Chalifoux, L V; Sehgal, P K; King, N W; Letvin, N L

    1983-01-01

    Spontaneously occurring rhesus monkey lymphomas were transmitted into healthy rhesus monkeys by using tumor cell suspensions. The naturally arising tumors included an immunoblastic sarcoma and an undifferentiated lymphoma. Recipient animals developed undifferentiated lymphomas, poorly differentiated lymphomas, or parenchymal lymphoproliferative abnormalities suggestive of early lesions of lymphoma. Some of these animals developed such opportunistic infections as cytomegalovirus hepatitis and cryptosporidiosis. They also showed evidence of an abnormal circulating peripheral blood mononuclear cell. These findings, all characteristic of the acquired immune deficiency syndrome (AIDS) of macaques, suggest a link between these transmissible lymphomas and AIDS in macaque monkeys. Images PMID:6576377

  16. Iliac arterial-enteric fistulas occurring after pelvic irradiation

    SciTech Connect

    Vetto, J.T.; Culp, S.C.; Smythe, T.B.; Chang, A.E.; Sindelar, W.F.; Sugarbaker, P.H.; Heit, H.A.; Giordano, J.M.; Kozloff, L.

    1987-05-01

    Fistulas from the iliac artery to the bowel constitute a condition that is often lethal. Excluding fistulas related to vascular grafts, a review of previously reported cases shows that they are most often due to atherosclerotic iliac aneurysms. Three unusual cases of this condition that occurred after high-dose pelvic irradiation for treatment of cancer are presented; in no case was recurrent tumor evident. These cases suggest that high-dose pelvic irradiation can predispose to the formation of iliac arterial-enteric fistulas, particularly if sepsis or inflammation develops. The definitive surgical management of these fistulas entails bowel resection, arterial ligation, and extra-anatomic bypass.

  17. An Update on Antitumor Activity of Naturally Occurring Chalcones

    PubMed Central

    Zhang, En-Hui; Wang, Ru-Feng; Guo, Shu-Zhen; Liu, Bin

    2013-01-01

    Chalcones, which have characteristic 1,3-diaryl-2-propen-1-one skeleton, are mainly produced in roots, rhizomes, heartwood, leaves, and seeds of genera Angelica, Sophora, Glycyrrhiza, Humulus, Scutellaria, Parartocarpus, Ficus, Dorstenia, Morus, Artocarpus, and so forth. They have become of interest in the research and development of natural antitumor agents over the past decades due to their broad range of mechanisms including anti-initiation, induction of apoptosis, antiproliferation, antimetastasis, antiangiogenesis, and so forth. This review summarizes the studies on the antitumor activity of naturally occurring chalcones and their underlying mechanisms in detail during the past decades. PMID:23690855

  18. Synthetic muscle promoters: activities exceeding naturally occurring regulatory sequences

    NASA Technical Reports Server (NTRS)

    Li, X.; Eastman, E. M.; Schwartz, R. J.; Draghia-Akli, R.

    1999-01-01

    Relatively low levels of expression from naturally occurring promoters have limited the use of muscle as a gene therapy target. Myogenic restricted gene promoters display complex organization usually involving combinations of several myogenic regulatory elements. By random assembly of E-box, MEF-2, TEF-1, and SRE sites into synthetic promoter recombinant libraries, and screening of hundreds of individual clones for transcriptional activity in vitro and in vivo, several artificial promoters were isolated whose transcriptional potencies greatly exceed those of natural myogenic and viral gene promoters.

  19. Synthetic muscle promoters: activities exceeding naturally occurring regulatory sequences

    NASA Technical Reports Server (NTRS)

    Li, X.; Eastman, E. M.; Schwartz, R. J.; Draghia-Akli, R.

    1999-01-01

    Relatively low levels of expression from naturally occurring promoters have limited the use of muscle as a gene therapy target. Myogenic restricted gene promoters display complex organization usually involving combinations of several myogenic regulatory elements. By random assembly of E-box, MEF-2, TEF-1, and SRE sites into synthetic promoter recombinant libraries, and screening of hundreds of individual clones for transcriptional activity in vitro and in vivo, several artificial promoters were isolated whose transcriptional potencies greatly exceed those of natural myogenic and viral gene promoters.

  20. On incompressibility of a matrix in naturally occurring composites

    NASA Astrophysics Data System (ADS)

    Gorbatikh, Larissa; Pingle, Pawan

    2007-12-01

    The work illustrates that a soft matrix, which has the Poisson ratio close to 0.5 and is reinforced with a rigid-line inclusion, possesses an interesting behavior at the inclusion/matrix interface. It experiences a hydrostatic stress state and behaves as an incompressible fluid under longitudinal and transverse loads. The stress singularities are eliminated ahead of the inclusion tips, and when interface defects are formed, their effect on the composite compliance is minimal. These observations have far reaching applications when one is interested in mechanisms of multifunctional property improvement of composites (such as toughness and stiffness) learned from naturally occurring composites.

  1. Thermoradiation inactivation of naturally occurring organisms in soil

    NASA Technical Reports Server (NTRS)

    Reynolds, M. C.; Lindell, K. F.; David, T. J.

    1973-01-01

    Samples of soil collected from Kennedy Space Center near spacecraft assembly facilities were found to contain microorganisms very resistant to conventional sterilization techniques. The inactivation behavior of the naturally occurring spores in soil was investigated using dry heat and ionizing radiation, first separately, then in combination. Dry heat inactivation rates of spores were determined for 105 and 125 C. Radiation inactivation rates were determined for dose rates of 660 and 76 krad/hr at 25 C. Simultaneous combinations of heat and radiation were then investigated at 105, 110, 115, 120, and 125 C. Combined treatment was found to be highly synergistic requiring greatly reduced radiation doses to accomplish sterilization.

  2. Majority of Americans Believe Global Warming Is Occurring, Survey Shows

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2013-04-01

    Seventy-eight percent of the American public believe that global warming has been occurring, according to a 2012 survey presented by Jon Krosnick, senior fellow with the Stanford Woods Institute for the Environment, at a 28 March briefing on Capitol Hill on the trajectory of public perceptions about global warming and government involvement in the issue. While the percentage has varied from 75% to 85% since 1997, the survey results "contradict any claims that Americans have turned away from this issue in large numbers," said Krosnick, who is also the Frederic O. Glover Professor in Humanities and Social Sciences at Stanford University, Calif. "They still believe that warming has been happening."

  3. Most deaths related to abortion occur in the developing world.

    PubMed

    Ciment, J

    1999-06-05

    A new publication of the World Health Organization, "Abortion in the Developing World," reports that 40% of the 50 million abortions performed each year are unsafe, and 90% of these medically perilous procedures occur in developing countries. Although the 30 million abortions performed annually in developing countries represent 60% of the global total, they account for 95% of abortion-related deaths. Abortion was illegal in 94% of the developing countries included in the WHO study. Unexpectedly, the proportion of women who were using contraception when they experienced an unintended pregnancy was similar in countries with strong family planning programs and those with weak or nonexistent programs.

  4. Laminin receptors for neurite formation

    SciTech Connect

    Kleinman, H.K.; Ogle, R.C.; Cannon, F.B.; Little, C.D.; Sweeney, T.M.; Luckenbill-Edds, L.

    1988-02-01

    Laminin, a basement membrane glycoprotein promotes both cell attachment and neurite outgrowth. Separate domains on laminin elicit these responses, suggesting that distinct receptors occur on the surface of cells. NG108-15 neuroblastoma-glioma cells rapidly extend long processes in the presence of laminin. The authors report here that /sup 125/I-labeled laminin specifically binds to these cells and to three membrane proteins of 67, 110, and 180 kDa. These proteins were isolated by affinity chromatography on laminin-Sepharose. The 67-kDa protein reacted with antibody to the previously characterized receptor for cell attachment to laminin. Antibodies to the 110-kDa and 180-kDa bands demonstrated that the 110-kDa protein was found in a variety of epithelial cell lines and in brain, whereas the 180-kDa protein was neural specific. Antibodies prepared against the 110-kDa and 180-kDa proteins inhibited neurite outgrowth induced by the neurite-promoting domain of laminin, whereas antibodies to the 67-kDa laminin receptor had no effect on neurite outgrowth. They conclude that neuronal cells have multiple cell-surface laminin receptors and that the 110-kDa and 180-kDa proteins are involved in neurite formation.

  5. Cutaneous Tuberculosis Occurring After a Skin Cut in a Child.

    PubMed

    Akkoc, Gulsen; Kepenekli Kadayifci, Eda; Karaaslan, Ayse; Atici, Serkan; Yakut, Nurhayat; Ocal Demir, Sevilya; Akbas, Gamze; Zeliha Cinel, Leyla; Soysal, Ahmet; Bakir, Mustafa

    2016-08-01

    Tuberculosis is a common problem in Turkey, and cutaneous tuberculosis is a rare form of extrapulmonary tuberculosis. Herein, the authors describe a case of cutaneous tuberculosis (lupus vulgaris) occurring after contact with a sheep. A 15-year-old boy was admitted to Marmara University School of Medicine Pendik Training and Research Hospital (Istanbul, Turkey) with delayed wound healing on the left index finger and left axillary lymphadenopathy. His medical history was unremarkable except for a wound incurred when he slaughtered a sheep 3 months before. One month after this injury, the patient developed enlargement of the left axillary lymph node on the side of the wounded extremity, and the wound turned a dark black color. The biopsy specimens obtained from the wounded skin and lymph nodes showed granulomatous reaction, but acid-fast bacilli (AFB) could not be shown with Ehrlich-Ziehl Neelsen staining. The patient tested positive in an interferon-gamma release assay. Computerized tomography scans of the thorax were normal, and early morning gastric lavage specimen was negative for AFB. The wound and axillary lymphadenopathy disappeared after institution of anti-tuberculosis therapy. Tuberculosis infection must be considered in chronic skin lesions with granulomatous reaction occurring in countries with high prevalence of tuberculosis.

  6. Regulation of naturally occurring radioactive materials in Australia.

    PubMed

    Jeffries, Cameron; Akber, Riaz; Johnston, Andrew; Cassels, Brad

    2011-07-01

    In order to promote uniformity between jurisdictions, the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) has developed the National Directory for Radiation Protection, which is a regulatory framework that all Australian governments have agreed to adopt. There is a large and diverse range of industries involved in mining or mineral processing, and the production of fossil fuels in Australia. Enhanced levels of naturally occurring radionuclides can be associated with mineral extraction and processing, other industries (e.g. metal recycling) and some products (e.g. plasterboard). ARPANSA, in conjunction with industry and State regulators, has undertaken a review and assessment of naturally occurring radioactive material (NORM) management in Australian industries. This review has resulted in guidance on the management of NORM that will be included in the National Directory for Radiation Protection. The first NORM safety guide provides the framework for NORM management and addresses specific NORM issues in oil and gas production, bauxite, aluminium and phosphate industries. Over time further guidance material for other NORM-related industries will be developed. This presentation will provide an overview of the regulatory approach to managing NORM industries in Australia.

  7. Co-occurring psychotic and addictive disorders: neurobiology and diagnosis.

    PubMed

    Ross, Stephen; Peselow, Eric

    2012-01-01

    Psychosis and substance abuse are intimately related. Psychotic spectrum illnesses commonly co-occur with substance use disorders (SUDs), and many substances of abuse can cause or exacerbate psychotic symptoms along a temporal spectrum from acute to chronic presentations. Despite the common co-occurrence between psychotic spectrum illnesses and SUDs, they are often under-recognized and undertreated, leading to poor treatment outcomes. Accurate detection and diagnosis of individuals with psychotic illness co-occurring with addictive disorders is key to properly treat such disorders. This article will review the nature of the relationship between psychosis and substance abuse by examining prevalence rates of each disorder alone and their rates of co-occurrence, the neurobiological basis for substance abuse comorbidity in schizophrenia spectrum disorders, key and salient aspects related to accurate diagnosis along a continuum from acute to subacute to chronic conditions, and pitfalls associated with diagnostic dilemmas. A case example will be used to highlight key points related to diagnostic challenges.

  8. Antitumor effects of naturally occurring oligomeric resveratrol derivatives.

    PubMed

    Qiao, Haishi; Chen, Xiaoqing; Xu, Lanfang; Wang, Jingjing; Zhao, Guoyan; Hou, Yayi; Ge, Hui Ming; Tan, Ren-Xiang; Li, Erguang

    2013-11-01

    This study was designed to evaluate and characterize the molecular basis of antitumor activity of naturally occurring resveratrol (RES; 3,5,4'-trihydroxy-trans-stilbene) derivatives. The compounds were isolated from plants in previous studies and characterized spectroscopically. The antitumor activities of 31 RES derivatives, including dimers, trimers, and tetramers of RES, were evaluated using cell-based assays and validated on a murine model. Several trimeric and a tetrameric stilbenoids induced tumor cell apoptosis or growth arrest of several tumor cell lines with IC50 values (2.8-19.7 μM), significantly lower than that of RES (IC50>70 μM). Using pauciflorol B (PauB) as an example, we showed that the compound induced apoptosis p53 dependently, inducing p53 accumulation and p53-modulated gene expression in cells with wild-type p53, but not in those with nonfunctional p53. Reexpression of p53 in p53-null cells rescued cell death response. In parallel, the MAPK/p38 was activated and critical for PauB-induced killing. Interestingly, activation of p38 in p53 deficient cells was sufficient to drive cells into senescence via the p16-pRb pathway. Finally, PauB dose-dependently inhibited tumor growth on nude mice. Naturally occurring trimeric and tetrameric stilbenoids are potent antitumor agents. Those compounds exert antitumor effect through p53-dependent induction of apoptosis or senescence.

  9. Daily intakes of naturally occurring radioisotopes in typical Korean foods.

    PubMed

    Choi, Min-Seok; Lin, Xiu-Jing; Lee, Sun Ah; Kim, Wan; Kang, Hee-Dong; Doh, Sih-Hong; Kim, Do-Sung; Lee, Dong-Myung

    2008-08-01

    The concentrations of naturally occurring radioisotopes ((232)Th, (228)Th, (230)Th, (228)Ra, (226)Ra, and (40)K) in typical Korean foods were evaluated. The daily intakes of these radioisotopes were calculated by comparing concentrations in typical Korean foods and the daily consumption rates of these foods. Daily intakes were as follows: (232)Th, 0.00-0.23; (228)Th, 0.00-2.04; (230)Th, 0.00-0.26; (228)Ra, 0.02-2.73; (226)Ra, 0.01-4.37 mBq/day; and (40)K, 0.01-5.71 Bq/day. The total daily intake of the naturally occurring radioisotopes measured in this study from food was 39.46 Bq/day. The total annual internal dose resulting from ingestion of radioisotopes in food was 109.83 muSv/y, and the radioisotope with the highest daily intake was (40)K. These values were same level compiled in other countries.

  10. Southeastern Australia's Submarine Landslides : a Model for Their Occurence

    NASA Astrophysics Data System (ADS)

    Hubble, T.; Clarke, S. L.; Yu, P.; Airey, D.; Keene, J.

    2012-12-01

    Recent work has identified an extensive region of the eastern Australian Continental Margin offshore Northern NSW and Southern Queensland which has experienced intense submarine erosion dominated by large-scale, submarine-landsliding that has removed enormous amounts of Neogene to recent sediment from the upper and middle continental slope. Preliminary findings demonstrate that i) some upper slope slides are geologically very young (< 20 kA), ii) the most recent slides occurred in relatively shallow depths and were volumetrically large enough (~3 cu km) to have been capable of generating damaging tsunami if shed as single masses and iii) the mid-slope slides are comprised of compacted Neogene sediments; iv) some of the mid-slope slide scars are huge (several 10's of cu km); and v) some of the mid-slope slide masses probably remained largely intact during sliding, potentially generated megatsunami, and are suspected to located on the abyssal Tasman Sea plain adjacent to the margin. A conceptual model that accounts for the apparent onset of sliding approximately 15 million years ago and the continuing deconstruction of the margin has been developed. This model posits that erosion of material from the middle and lower slope by deep, cold-water, ocean currents originating in Antartica occurred contemporaneously with an increase in the frequency and intensity of earthquakes due to increasing tectonic interaction between Australia and Asia. These two processes acted together to initiate and then sustain the submarine landsliding.

  11. Interactome disassembly during apoptosis occurs independent of caspase cleavage.

    PubMed

    Scott, Nichollas E; Rogers, Lindsay D; Prudova, Anna; Brown, Nat F; Fortelny, Nikolaus; Overall, Christopher M; Foster, Leonard J

    2017-01-12

    Protein-protein interaction networks (interactomes) define the functionality of all biological systems. In apoptosis, proteolysis by caspases is thought to initiate disassembly of protein complexes and cell death. Here we used a quantitative proteomics approach, protein correlation profiling (PCP), to explore changes in cytoplasmic and mitochondrial interactomes in response to apoptosis initiation as a function of caspase activity. We measured the response to initiation of Fas-mediated apoptosis in 17,991 interactions among 2,779 proteins, comprising the largest dynamic interactome to date. The majority of interactions were unaffected early in apoptosis, but multiple complexes containing known caspase targets were disassembled. Nonetheless, proteome-wide analysis of proteolytic processing by terminal amine isotopic labeling of substrates (TAILS) revealed little correlation between proteolytic and interactome changes. Our findings show that, in apoptosis, significant interactome alterations occur before and independently of caspase activity. Thus, apoptosis initiation includes a tight program of interactome rearrangement, leading to disassembly of relatively few, select complexes. These early interactome alterations occur independently of cleavage of these protein by caspases.

  12. A naturally-occurring 'cold earth' spot in Northern China.

    PubMed

    Niu, Fujun; Cheng, Guodong; Niu, Yonghong; Zhang, Mingyi; Luo, Jing; Lin, Zhanju

    2016-09-29

    Permafrost is determined to a large extent by the Earth's surface temperature, therefore it distributes mainly in high altitude and latitude regions. However, stable, warm (about -1 °C) permafrost occurs within a scree slope in northern China that is more than 600 km south of the southernmost limit of latitudinal permafrost on the Eurasian Continent. It is at an elevation of only 900 m above sea level (ASL). The area has a mean annual air temperature (MAAT) of 6 to 8 °C. Thermal processes of the scree slope, investigated through field monitoring and numerical simulation, showed that the permafrost is caused by winter air convection within the porous rock deposits and is stable as air convection does not occur in summer time. The deposit is covered by a 30-cm-thick peaty soil layer dated (carbon C-14) to between 1,000 to 1,600 years ago. The layer also contributes to the permafrost's existence due to the peat's thermal conductivity offset when frozen and thawed. The existence of permafrost under such warm climatic conditions confirms the effectiveness of using crushed rock layer as basement or slope cover to protect the warm permafrost subgrade of the recently-constructed Qinghai-Tibet Railway (QTR), even under the predicted climate warming conditions.

  13. Economic losses occurring due to brucellosis in Indian livestock populations.

    PubMed

    Singh, B B; Dhand, N K; Gill, J P S

    2015-05-01

    Brucellosis is a serious public health issue in India. Estimation of economic losses occurring due to brucellosis is required to help formulate prevention and control strategies, but has not been done in India. We estimated economic losses due to brucellosis by sourcing prevalence data from epidemiological surveys conducted in India. Data for livestock populations were obtained from official records. Probability distributions were used for many of the input parameters to account for uncertainty and variability. The analysis revealed that brucellosis in livestock is responsible for a median loss of US $ 3.4 billion (5th-95th percentile 2.8-4.2 billion). The disease in cattle and buffalo accounted for 95.6% of the total losses occurring due to brucellosis in livestock populations. The disease is responsible for a loss of US $ 6.8 per cattle, US$18.2 per buffalo, US $ 0.7 per sheep, US $ 0.5 per goat and US $ 0.6 per pig. These losses are additional to the economic and social consequences of the disease in humans. The results suggest that the disease causes significant economic losses in the country and should be controlled on a priority basis.

  14. Effects of later-occurring nonlinguistic sounds on speech categorization.

    PubMed

    Wade, Travis; Holt, Lori L

    2005-09-01

    Nonspeech stimuli influence phonetic categorization, but effects observed so far have been limited to precursors' influence on perception of following speech. However, both preceding and following speech affect phonetic categorization. This asymmetry raises questions about whether general auditory processes play a role in context-dependent speech perception. This study tested whether the asymmetry stems from methodological issues or genuine mechanistic limitations. To determine whether and how backward effects of nonspeech context on speech may occur, one experiment examined perception of CVC words with [ga]-[da] series onsets followed by one of two possible embedded tones and one of two possible final consonants. When the tone was separated from the target onset by 100 ms, contrastive effects of tone frequency similar to those of previous studies were observed; however, when the tone was moved closer to the target segment assimilative effects were observed. In another experiment, contrastive effects of a following tone were observed in both CVC words and CV nonwords, although the size of the effects depended on syllable structure. Results are discussed with respect to contrastive mechanisms not speech-specific but operating at a relatively high level, taking into account spectrotemporal patterns occurring over extended periods before and after target events.

  15. On the Mechanical Friction Losses Occurring in Automotive Differential Gearboxes

    PubMed Central

    Antoni, Grégory

    2014-01-01

    In the automobile industry, the mechanical losses resulting from friction are largely responsible for various kinds of surface damage, such as the scuffing occurring in some mechanical assemblies. These scuffing processes seem to be due to a local loss of lubrication between certain mechanical elements of the same assembly, leading to a sharp increase in the friction, which can lead to a surface and volume damage in some of them, and even can cause, in the worst case, the whole destruction of the mechanical system if it has continued to operate. Predicting and checking the occurrence of this kind of undesirable phenomena, especially in some principal systems of the vehicle, represents nowadays, a crucial challenge in terms of automobile reliability and safety. This study focuses on the mechanical friction losses liable to occur in differential automobile gearboxes, which can lead in the long term to the scuffing of these mechanical systems. The friction losses involved were modeled, using a simple analytical approach, which is presented and discussed. PMID:24719579

  16. Macaques Exhibit a Naturally-Occurring Depression Similar to Humans

    PubMed Central

    Xu, Fan; Wu, Qingyuan; Xie, Liang; Gong, Wei; Zhang, Jianguo; Zheng, Peng; Zhou, Qinmin; Ji, Yongjia; Wang, Tao; Li, Xin; Fang, Liang; Li, Qi; Yang, Deyu; Li, Juan; Melgiri, Narayan D.; Shively, Carol; Xie, Peng

    2015-01-01

    Rodent models have dominated preclinical investigations into the mechanisms of depression. However, these models-which rely on subjecting individual rodents to physical stressors - do not realistically resemble the etiopathological development of depression, which occurs naturally in a social context. A non-human primate model that better reflects the social ethological aspects of depression would be more advantageous to investigating pathophysiological mechanisms and developing antidepressant therapeutics. Here, we describe and model a naturally-occurring depressive state in a non-human primate species, the cynomolgus monkey (Macaca fascicularis), in a realistic social ethological context and associate the depressed behavioral phenotype with significant serum metabolic perturbations. One to two subjects per stable social colony (17–22 subjects) manifested a depressive phenotype that may be attributed to psychosocial stress. In accordance with rodent and human studies, the serum metabolic phenotype of depressed and healthy subjects significantly differed, supporting the model's face validity. However, application of the fast-acting antidepressant ketamine failed to demonstrate predictive validity. This study proposes a non-human primate depression model in a realistic social ethological context that can better approximate the psychosocial stressors underlying depression. PMID:25783476

  17. Severe droughts have occurred in the northeastern United States

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2011-12-01

    People do not usually consider the northeastern United States to be a drought-prone region, but new evidence shows that mega-droughts have occurred there in the past. Dorothy Peteet of Columbia University and NASA's Goddard Institute for Space Studies reported at the AGU Fall Meeting in San Francisco, Calif., on her analysis of sediment cores in marshes in New York State. Different chemicals flow into a marsh from freshwater upriver and from saltwater from the ocean; higher concentrations of bromine and calcium, which are more common in saltwater, indicate a drier period. The data indicate that at least three mega-droughts occurred in the past 6000 years, the longest during what scientists term as the “Medieval warm period,” which lasted from about 850 C.E. to 1350 C.E. “People don't think of this area as threatened by droughts because we've been in a wet period,” Peteet said.

  18. Insights into secondary reactions occurring during atmospheric ablation of micrometeoroids

    NASA Astrophysics Data System (ADS)

    Court, Richard W.; Tan, Jonathan

    2016-06-01

    Ablation of micrometeoroids during atmospheric entry yields volatile gases such as water, carbon dioxide, and sulfur dioxide, capable of altering atmospheric chemistry and hence the climate and habitability of the planetary surface. While laboratory experiments have revealed the yields of these gases during laboratory simulations of ablation, the reactions responsible for the generation of these gases have remained unclear, with a typical assumption being that species simply undergo thermal decomposition without engaging in more complex chemistry. Here, pyrolysis-Fourier transform infrared spectroscopy reveals that mixtures of meteorite-relevant materials undergo secondary reactions during simulated ablation, with organic matter capable of taking part in carbothermic reduction of iron oxides and sulfates, resulting in yields of volatile gases that differ from those predicted by simple thermal decomposition. Sulfates are most susceptible to carbothermic reduction, producing greater yields of sulfur dioxide and carbon dioxide at lower temperatures than would be expected from simple thermal decomposition, even when mixed with meteoritically relevant abundances of low-reactivity Type IV kerogen. Iron oxides were less susceptible, with elevated yields of water, carbon dioxide, and carbon monoxide only occurring when mixed with high abundances of more reactive Type III kerogen. We use these insights to reinterpret previous ablation simulation experiments and to predict the reactions capable of occurring during ablation of carbonaceous micrometeoroids in atmospheres of different compositions.

  19. Ingestion analgesia occurs when a bad taste turns good.

    PubMed

    Foo, Hayley; Mason, Peggy

    2011-12-01

    During ingestion of water, chocolate, sucrose, and saccharin, pain-related behaviors are suppressed. This ingestion analgesic effect is reversed when the hedonic valence of a food is switched from "good" to "bad" as occurs during conditioned taste aversion. Here, we tested the converse hedonic shift to determine if ingestion analgesia occurs when 0.3 M NaCl is made palatable by inducing a sodium appetite. In Experiment 1, sham- and sodium-depleted rats were tested for paw withdrawal and lick latencies to brief noxious heat during quiet wake and intraoral NaCl ingestion. Only sodium-depleted rats showed a suppression of heat-evoked reactions during NaCl ingestion. In Experiment 2, we tested whether this analgesic effect is mediated by the brainstem nucleus raphe magnus (NRM). Inactivation of NRM with muscimol blocked ingestion analgesia during NaCl ingestion by sodium-depleted rats. This attenuation was not due to a hyperalgesic effect of NRM inactivation. Muscimol microinjections into a nearby region, the nucleus raphe obscurus (NRO), were ineffective. The present findings demonstrate that the internal milieu of an animal can modify ingestion analgesia, and that the analgesia during NaCl ingestion by sodium hungry rats is mediated by NRM. PsycINFO Database Record (c) 2011 APA, all rights reserved.

  20. On the mechanical friction losses occurring in automotive differential gearboxes.

    PubMed

    Antoni, Grégory

    2014-01-01

    In the automobile industry, the mechanical losses resulting from friction are largely responsible for various kinds of surface damage, such as the scuffing occurring in some mechanical assemblies. These scuffing processes seem to be due to a local loss of lubrication between certain mechanical elements of the same assembly, leading to a sharp increase in the friction, which can lead to a surface and volume damage in some of them, and even can cause, in the worst case, the whole destruction of the mechanical system if it has continued to operate. Predicting and checking the occurrence of this kind of undesirable phenomena, especially in some principal systems of the vehicle, represents nowadays, a crucial challenge in terms of automobile reliability and safety. This study focuses on the mechanical friction losses liable to occur in differential automobile gearboxes, which can lead in the long term to the scuffing of these mechanical systems. The friction losses involved were modeled, using a simple analytical approach, which is presented and discussed.

  1. Multifaceted ability of naturally occurring polyphenols against metastatic cancer.

    PubMed

    Zhou, Qingyu; Bennett, Lunawati L; Zhou, Shufeng

    2016-04-01

    Although cancer metastases are known to be the main cause of cancer-related deaths, truly effective antimetastatic therapeutics remain scarce in clinical practice. Naturally occurring polyphenols are the most abundant antioxidants in human diets. Many of them possess chemopreventive and chemotherapeutic properties against various types of cancer. Recent advances in understanding the molecular pathways that mediate cancer development and progression have led to an increase of interest in preclinical investigations on the mechanisms underlying anticancer activity of polyphenols. In particular, an increasing number of preclinical studies using cultured cells and animal models have demonstrated the inhibitory effects of polyphenols on tumour cell invasion and metastasis, thereby highlighting the potential of polyphenols against metastatic cancer. This review specifically addresses growing evidence of the capability of polyphenols to impair the invasion and migration of tumour cells through a diverse set of mechanisms, including downregulation of expression of matrix metalloproteinases, modulation of regulators of epithelial-mesenchymal transition, interference with Met signalling, inhibition of nuclear factor-kappa B mediated transcription, and so on. Given that metastasis occurs through a multistep process in which each step is regulated by a complex network of signalling pathways, the multi-function and multi-target characteristics of polyphenols render those promising candidates for effective adjuvant therapy against metastatic cancer.

  2. Testosterone release and social context: when it occurs and why.

    PubMed

    Gleason, Erin D; Fuxjager, Matthew J; Oyegbile, Temitayo O; Marler, Catherine A

    2009-10-01

    The functions of rapid increases in testosterone seem paradoxical because they can occur in response to different social contexts, such as male-male aggressive encounters and male-female sexual encounters. This suggests that context may impact the functional consequences of changes in testosterone, whether transient or long term. Many studies, including those with California mice (Peromyscus californicus), have addressed these issues using manipulations and species comparisons, but many areas remain to be investigated. We report a study here that suggests transient increases in testosterone after social competition influence future competitive behavior, but social experience alone may also be critical in determining future behavior. In other rodents, a comparable testosterone surge occurs in response to sexual stimulation, but the function is not entirely understood. In addition to competitive and sexual behavior, testosterone impacts other systems instrumental to social behaviors, including paternal behavior and degree of monogamy. Thus, mechanisms regulated by testosterone, such as the vasopressin and aromatase systems, may also be influenced by rapid surges of testosterone in aggressive or sexual contexts. We discuss how the functions of testosterone may overlap in some contexts.

  3. Timing of postoperative respiratory emergencies: when do they really occur?

    PubMed

    Weingarten, Toby N; Warner, Lindsay L; Sprung, Juraj

    2017-02-01

    Opioid-induced postoperative respiratory depression has garnered attention and calls for vigilance. However, a higher level of monitoring equates to increased use of hospital resources and is impractical to apply for all postoperative patients. Understanding the temporal pattern of postoperative respiratory emergency occurrences would allow for improved triage of monitoring resources for high-risk patients. Our objective is to describe the temporal pattern of risk of postoperative opioid-induced respiratory failure. The literature suggests that postoperative opioid-induced respiratory depression is more frequent and severe than previously believed. In response, national patient advocacy groups have proposed improved postoperative monitoring of high-risk patients, especially those with sleep-disordered breathing. Published series of patients who have had adverse respiratory events suggest that the first 24 postsurgical hours comprise the period of highest risk, with most events occurring within the first 12 h. Further, study findings have suggested that adverse respiratory events often occur shortly after administration of opioid analgesics. Emerging evidence indicates that the first postsurgical day carries the highest risk of adverse respiratory events, and this risk is often associated with opioid administration. Resources for increased monitoring should be directed to these high-risk times.

  4. Aggregatibacter actinomycetemcomitans leukotoxin cytotoxicity occurs through bilayer destabilization

    PubMed Central

    Brown, Angela C.; Boesze-Battaglia, Kathleen; Du, Yurong; Stefano, Frank P.; Kieba, Irene R.; Epand, Raquel F.; Kakalis, Lazaros; Yeagle, Philip L.; Epand, Richard M.; Lally, Edward T.

    2012-01-01

    Summary The Gram-negative bacterium, Aggregatibacter actinomycetemcomitans, is a common inhabitant of the human upper aerodigestive tract. The organism produces an RTX (Repeats in ToXin) toxin (LtxA) that kills human white blood cells. LtxA is believed to be a membrane-damaging toxin, but details of the cell surface interaction for this and several other RTX toxins have yet to be elucidated. Initial morphological studies suggested that LtxA was bending the target cell membrane. Because the ability of a membrane to bend is a function of its lipid composition, we assessed the proficiency of LtxA to release of a fluorescent dye from a panel of liposomes composed of various lipids. Liposomes composed of lipids that form nonlamellar phases were susceptible to LtxA-induced damage while liposomes composed of lipids that do not form non-bilayer structures were not. Differential scanning calorimetry demonstrated that the toxin decreased the temperature at which the lipid transitions from a bilayer to a nonlamellar phase, while 31P nuclear magnetic resonance studies showed that the LtxA-induced transition from a bilayer to an inverted hexagonal phase occurs through the formation of an isotropic intermediate phase. These results indicate that LtxA cytotoxicity occurs through a process of membrane destabilization. PMID:22309134

  5. Serum concentration of sialic acids in naturally occurring ovine babesiosis.

    PubMed

    Esmaeilnejad, Bijan; Tavassoli, Mousa; Asri-Rezaei, Siamak; Dalir-Naghadeh, Bahram; Abtahi Froushani, Seyyed Meysam; Arjmand, Jafar; Golabi, Mostafa

    2014-10-01

    This study is designated to assess the effect of the severity of Babesia ovis infection on sialic acid concentration in blood sera in naturally infected sheep. Infected animals (diseased group) comprised 38 Iranian fat-tailed sheep, about 1-3 years old, naturally infected with B. ovis, divided into four subgroups with respect to parasitemia rates (low 0.1-0.3 %, moderate 0.4-0.9 %, high 1-2.5 %, and very high >2.5 %). The parasitological diagnosis was confirmed using PCR analysis. As a control group, ten clinically healthy sheep reared under the same management and environmental conditions were also sampled. Hematological parameters and the concentrations of total sialic acid (TSA), lipid-bound sialic acid (LBSA), and protein-bound sialic acid (PBSA) were measured in both groups. Compared to controls, sialic acid concentrations showed significant increase (p < 0.05) in infected sheep. Parasitemia rate was positively correlated with sialic acid concentrations. This study demonstrated that B. ovis infection induced marked and persistent elevations of serum sialic acid concentrations. It seems that increase of serum sialic acid concentrations during parasitemia alter receptor-ligand interactions, which are known to play important role in immune response. Furthermore, sialic acid would indirectly inhibit the action of leukocytes and consequently promote the evasion of the immune response and persistence of the parasite in the host. This factor could influence the parasite-host cell adhesion, but further detailed biochemical investigations are needed to precisely explain the exact role of sialic acid in invasion process of the parasite to the host cells.

  6. Exploring naturally occurring ivy nanoparticles as an alternative biomaterial.

    PubMed

    Huang, Yujian; Wang, Yi-Jun; Wang, Yongzhong; Yi, Sijia; Fan, Zhen; Sun, Leming; Lin, Derrick; Anreddy, Nagaraju; Zhu, Hua; Schmidt, Michael; Chen, Zhe-Sheng; Zhang, Mingjun

    2015-10-01

    Arabinoglactan protein (AGP)-rich nanoparticles obtained from the sticky exudates of Hedera helix (English ivy), have shown promising potential to be used in nanomedicine owing to their excellent aqueous solubility, low intrinsic viscosity, biocompatibility, and biodegradability. In this study, the feasibilities of utilizing ivy nanoparticles (INPs) as nano-carriers for delivering chemotherapeutic drugs in cancer therapy and as nano-fillers to develop novel scaffolds for tissue engineering in regenerative medicine are evaluated. Via electrostatic and hydrophobic interactions, pH-responsive nanoconjugates are formed between the INPs and the doxorubicin (DOX) with an entrapment ratio of 77.9±3.9%. While the INPs show minimal cytotoxicity, the formed INP-DOX conjugates exhibit substantially stronger cytotoxic activity than free DOX against multiple cancer cell lines, suggesting a synergistic effect is established upon conjugation. The anti-cancer effects of the INP-DOX conjugates are further evaluated via in vivo xenograft assays by subcutaneously implanting DOX resistant cell line, SW620/Ad-300, into nude mice. The tumor volumes in mice treated with the INP-DOX conjugates are significantly less than those of the mice treated with free DOX. In addition, the INPs are further exploited as nano-fillers to develop fibrous scaffolds with collagen, via mimicking the porous matrix where the INPs are embedded under natural condition. Enhanced adhesion of smooth muscle cells (SMCs) and accelerated proliferation of mouse aortic SMCs are observed in this newly constructed scaffold. Overall, the results obtained from the present study suggest great potential of the INPs to be used as biocompatible nanomaterials in nanomedicine. The AGP-rich INP renders a glycoprotein architecture that is amenable for modification according to the functional designs, capable of being developed as versatile nanomaterials for extensive biomedical applications. Naturally occurring organic

  7. Definition of target antigens for naturally occurring CD4(+) CD25(+) regulatory T cells.

    PubMed

    Nishikawa, Hiroyoshi; Kato, Takuma; Tawara, Isao; Saito, Kanako; Ikeda, Hiroaki; Kuribayashi, Kagemasa; Allen, Paul M; Schreiber, Robert D; Sakaguchi, Shimon; Old, Lloyd J; Shiku, Hiroshi

    2005-03-07

    The antigenic targets recognized by naturally occurring CD4(+) CD25(+) regulatory T cells (T reg cells) have been elusive. We have serologically defined a series of broadly expressed self-antigens derived from chemically induced mouse sarcomas by serological identification of antigens by recombinant expression cloning (SEREX). CD4(+) CD25(+) T cells from mice immunized with SEREX-defined self-antigens had strong suppressive activity on peptide-specific proliferation of CD4(+) CD25(-) T cells and CD8(+) T cells. The suppressive effect was observed without in vitro T cell stimulation. Foxp3 expression in these CD4(+) CD25(+) T cells from immunized mice was 5-10 times greater than CD4(+) CD25(+) T cells derived from naive mice. The suppressive effect required cellular contact and was blocked by anti-glucocorticoid-induced tumor necrosis factor receptor family-related gene antibody. In vitro suppressive activity essentially disappeared 8 wk after the last immunization. However, it was regained by in vitro restimulation with cognate self-antigen protein but not with control protein. We propose that SEREX-defined self-antigens such as those used in this study represent self-antigens that elicit naturally occurring CD4(+) CD25(+) T reg cells.

  8. A Conversion of Oral Cannabidiol to Delta9-Tetrahydrocannabinol Seems Not to Occur in Humans

    PubMed Central

    Nahler, Gerhard; Grotenhermen, Franjo; Zuardi, Antonio Waldo; Crippa, José A.S.

    2017-01-01

    Abstract Cannabidiol (CBD), a major cannabinoid of hemp, does not bind to CB1 receptors and is therefore devoid of psychotomimetic properties. Under acidic conditions, CBD can be transformed to delta9-tetrahydrocannabinol (THC) and other cannabinoids. It has been argued that this may occur also after oral administration in humans. However, the experimental conversion of CBD to THC and delta8-THC in simulated gastric fluid (SGF) is a highly artificial approach that deviates significantly from physiological conditions in the stomach; therefore, SGF does not allow an extrapolation to in vivo conditions. Unsurprisingly, the conversion of oral CBD to THC and its metabolites has not been observed to occur in vivo, even after high doses of oral CBD. In addition, the typical spectrum of side effects of THC, or of the very similar synthetic cannabinoid nabilone, as listed in the official Summary of Product Characteristics (e.g., dizziness, euphoria/high, thinking abnormal/concentration difficulties, nausea, tachycardia) has not been observed after treatment with CBD in double-blind, randomized, controlled clinical trials. In conclusion, the conversion of CBD to THC in SGF seems to be an in vitro artifact. PMID:28861507

  9. A Conversion of Oral Cannabidiol to Delta9-Tetrahydrocannabinol Seems Not to Occur in Humans.

    PubMed

    Nahler, Gerhard; Grotenhermen, Franjo; Zuardi, Antonio Waldo; Crippa, José A S

    2017-01-01

    Cannabidiol (CBD), a major cannabinoid of hemp, does not bind to CB1 receptors and is therefore devoid of psychotomimetic properties. Under acidic conditions, CBD can be transformed to delta9-tetrahydrocannabinol (THC) and other cannabinoids. It has been argued that this may occur also after oral administration in humans. However, the experimental conversion of CBD to THC and delta8-THC in simulated gastric fluid (SGF) is a highly artificial approach that deviates significantly from physiological conditions in the stomach; therefore, SGF does not allow an extrapolation to in vivo conditions. Unsurprisingly, the conversion of oral CBD to THC and its metabolites has not been observed to occur in vivo, even after high doses of oral CBD. In addition, the typical spectrum of side effects of THC, or of the very similar synthetic cannabinoid nabilone, as listed in the official Summary of Product Characteristics (e.g., dizziness, euphoria/high, thinking abnormal/concentration difficulties, nausea, tachycardia) has not been observed after treatment with CBD in double-blind, randomized, controlled clinical trials. In conclusion, the conversion of CBD to THC in SGF seems to be an in vitro artifact.

  10. Evolutionary diversification of the trypanosome haptoglobin-haemoglobin receptor from an ancestral haemoglobin receptor

    PubMed Central

    Lane-Serff, Harriet; MacGregor, Paula; Peacock, Lori; Macleod, Olivia JS; Kay, Christopher; Gibson, Wendy; Higgins, Matthew K; Carrington, Mark

    2016-01-01

    The haptoglobin-haemoglobin receptor of the African trypanosome species, Trypanosoma brucei, is expressed when the parasite is in the bloodstream of the mammalian host, allowing it to acquire haem through the uptake of haptoglobin-haemoglobin complexes. Here we show that in Trypanosoma congolense this receptor is instead expressed in the epimastigote developmental stage that occurs in the tsetse fly, where it acts as a haemoglobin receptor. We also present the structure of the T. congolense receptor in complex with haemoglobin. This allows us to propose an evolutionary history for this receptor, charting the structural and cellular changes that took place as it adapted from a role in the insect to a new role in the mammalian host. DOI: http://dx.doi.org/10.7554/eLife.13044.001 PMID:27083048

  11. Feedback, receptor clustering, and receptor restriction to single cells yield large Turing spaces for ligand-receptor-based Turing models

    NASA Astrophysics Data System (ADS)

    Kurics, Tamás; Menshykau, Denis; Iber, Dagmar

    2014-08-01

    Turing mechanisms can yield a large variety of patterns from noisy, homogenous initial conditions and have been proposed as patterning mechanism for many developmental processes. However, the molecular components that give rise to Turing patterns have remained elusive, and the small size of the parameter space that permits Turing patterns to emerge makes it difficult to explain how Turing patterns could evolve. We have recently shown that Turing patterns can be obtained with a single ligand if the ligand-receptor interaction is taken into account. Here we show that the general properties of ligand-receptor systems result in very large Turing spaces. Thus, the restriction of receptors to single cells, negative feedbacks, regulatory interactions among different ligand-receptor systems, and the clustering of receptors on the cell surface all greatly enlarge the Turing space. We further show that the feedbacks that occur in the FGF10-SHH network that controls lung branching morphogenesis are sufficient to result in large Turing spaces. We conclude that the cellular restriction of receptors provides a mechanism to sufficiently increase the size of the Turing space to make the evolution of Turing patterns likely. Additional feedbacks may then have further enlarged the Turing space. Given their robustness and flexibility, we propose that receptor-ligand-based Turing mechanisms present a general mechanism for patterning in biology.

  12. A search for presynaptic inhibitory histamine receptors in guinea-pig tissues: Further H3 receptors but no evidence for H4 receptors.

    PubMed

    Petri, Doris; Schlicker, Eberhard

    2016-07-01

    The histamine H4 receptor is coupled to Gi/o proteins and expressed on inflammatory cells and lymphoid tissues; it was suggested that this receptor also occurs in the brain or on peripheral neurones. Since many Gi/o protein-coupled receptors, including the H3 receptor, serve as presynaptic inhibitory receptors, we studied whether the sympathetic neurones supplying four peripheral tissues and the cholinergic neurones in the hippocampus from the guinea-pig are equipped with release-modulating H4 and H3 receptors. For this purpose, we preincubated tissue pieces from the aorta, atrium, renal cortex and vas deferens with (3)H-noradrenaline and hippocampal slices with (3)H-choline and determined the electrically evoked tritium overflow. The stimulation-evoked overflow in the five superfused tissues was inhibited by the muscarinic receptor agonist oxotremorine, which served as a positive control, but not affected by the H4 receptor agonist 4-methylhistamine. The H3 receptor agonist R-α-methylhistamine inhibited noradrenaline release in the peripheral tissues without affecting acetylcholine release in the hippocampal slices. Thioperamide shifted the concentration-response curve of histamine in the aorta and the renal cortex to the right, yielding apparent pA2 values of 8.0 and 8.1, respectively, which are close to its affinity at other H3 receptors but higher by one log unit than its pKi at the H4 receptor of the guinea-pig. In conclusion, histamine H4 receptors could not be identified in five experimental models of the guinea-pig that are suited for the detection of presynaptic inhibitory receptors whereas H3 receptors could be shown in the peripheral tissues but not in the hippocampus. This article is part of the Special Issue entitled 'Histamine Receptors'.

  13. Is anyone regulating naturally occurring radioactive material? A state survey

    SciTech Connect

    Gross, E.M.; Barisas, S.G.

    1993-08-01

    As far as we know, naturally occurring radioactive material (NORM) has surrounded humankind since the beginning of time. However, recent data demonstrating that certain activities concentrate NORM have increased concern regarding its proper handling and disposal and precipitated the development of new NORM-related regulations. The regulation of NORM affects the management of government facilities as well as a broad range of industrial processes. Recognizing that NORM regulation at the federal level is extremely limited, Argonne National Laboratory (ANL) conducted a 50-state survey to determine the extent to which states have assumed the responsibility for regulating NORM as well as the NORM standards that are currently being applied at the state level. Though the survey indicates that NORM regulation comprises a broad spectrum of controls from full licensing requirements to virtually no regulation at afl, a trend is emerging toward recognition of the need for increased regulation of potential NORM hazards, particularly in the absence of federal standards.

  14. Resolutions of Problems that Occurred in SPEAR3 Magnet Production

    SciTech Connect

    Li, Nanyang

    2005-05-27

    Some problems occurred during the SPEAR3 magnet production at IHEP, China. It was very hard to find resolution from existing knowledge of those problems. It was possible that similar problems might have happen in building accelerator magnet in other institutes before, but they were not addressed in public papers. These problems were discussed and solved by engineers from both SLAC and IHEP after conducting certain experiments. Traditionally, the magnet design and measurement data have been always well documented and addressed in papers, but the production experiences have not been recorded adequately. It is the goal of this paper to record the problems and their resolutions during SPEAR3 magnet production at IHEP China, which will certainly benefit future magnet projects.

  15. Babesia Species Occurring in Austrian Ixodes ricinus Ticks▿

    PubMed Central

    Blaschitz, Marion; Narodoslavsky-Gföller, Melanie; Kanzler, Michaela; Stanek, Gerold; Walochnik, Julia

    2008-01-01

    Babesiosis is a tick-transmitted disease of veterinary and medical importance. The first Austrian case of human babesiosis was recently recorded. In the current study, ticks at all life cycle stages (instars), including 853 Ixodes ricinus and 11 Haemaphysalis concinna ticks, from sampling sites throughout Austria were examined for the presence of Babesia spp. by using 18S rRNA gene PCR and sequencing, and the overall mean infection rate was 51.04%. The infection rates for sampling sites were highly variable, ranging from 0% to almost 100%. Different instars and different sexes were infected almost equally. Babesia isolates occurring in Austrian ticks were identified as Babesia divergens, Babesia divergens-like, and Babesia sp. strain DD by sequencing a fragment of the heat shock protein 70 gene and internal transcribed spacer regions 1 and 2. To our knowledge, this is the first investigation of Babesia spp. in Austrian ticks. PMID:18539787

  16. Lupus vulgaris occurring in a locus minoris resistentiae.

    PubMed

    Long, Richard; Beatch, Anita; Lee, Mao-Cheng; Cheung-Lee, Melody; Wasel, Norman

    2009-01-01

    The pathogenesis of lupus vulgaris, a form of cutaneous tuberculosis, is not always clear, especially in patients who do not have coexistent extracutaneous tuberculosis and in patients with single lesions. To report a case of lupus vulgaris in a locus minoris resistentiae (a site of reduced resistance) and to use a unique set of clinical circumstances and laboratory tests to reconstruct the pathogenesis of the lesion and the response to treatment. Lupus vulgaris can occur in a locus minoris resistentiae; local trauma and possibly other factors, such as increased temperature, topical corticosteroids, and the virulence of the infecting strain, may facilitate the growth of Mycobacterium tuberculosis present at a locus minoris resistentiae as a result of a silent bacillemia.

  17. Antibacterial mesh: a novel technique involving naturally occurring cellular proteins.

    PubMed

    Yurko, Yuliya; McDeavitt, Kathleen; Kumar, Rohan Satish; Martin, Terri; Prabhu, Ajita; Lincourt, Amy E; Vertegel, Alexey; Heniford, B Todd

    2012-03-01

    Naturally occurring antimicrobial peptides are possibly the "next frontier" in infection prevention. Binding them to mesh could reduce the rate of mesh infections. This study identifies an antimicrobial agent capable of significant antibacterial activity when bound to mesh. Lysozyme, human beta defensin (HBD-3), human cathelicidin (LL-37), and lysostaphin were adsorbed to polypropylene mesh at various concentrations. Treated meshes were placed in a suspension of 1 × 10(6) Staphylococcus aureus. Antibacterial action was monitored by turbidimetric assay, fluorescent imaging, and a colony counting method. A very high rate of lysis of S aureus cells was observed in the lysostaphin-treated group as measured by optical density; none survived as seen on colony count assays. Optical density for mesh coated with lysozyme, HBD-3, and LL-37 did not differ from untreated controls, with 100% survival rates by colony counts. Lysostaphin had superior antibacterial activity following adsorption to mesh.

  18. Profiles in patient safety: when an error occurs.

    PubMed

    Hobgood, Cherri; Hevia, Armando; Hinchey, Paul

    2004-07-01

    Medical error is now clearly established as one of the most significant problems facing the American health care system. Anecdotal evidence, studies of human cognition, and analysis of high-reliability organizations all predict that despite excellent training, human error is unavoidable. When an error occurs and is recognized, providers have a duty to disclose the error. Yet disclosure of error to patients, families, and hospital colleagues is a difficult and/or threatening process for most physicians. A more thorough understanding of the ethical and social contract between physicians and their patients as well as the professional milieu surrounding an error may improve the likelihood of its disclosure. Key among these is the identification of institutional factors that support disclosure and recognize error as an unavoidable part of the practice of medicine. Using a case-based format, this article focuses on the communication of error with patients, families, and colleagues and grounds error disclosure in the cultural milieu of medial ethics.

  19. Crocoite: An unusual mode of occurence for lead in coal

    USGS Publications Warehouse

    Li, Z.; Moore, T.A.; Weaver, S.D.; Finkelman, R.B.

    2001-01-01

    What is believed to be a very unusual mode of occurrence for lead in coal has been identified as crocoite (PbCrO4). As part of a larger study on trace elements and mineralogy in the Cretaceous Main Seam in New Zealand, crocoite was found in raw coal samples within the lower part of the coal seam. X-ray diffraction (XRD) and bulk chemical data from a SEM equipped with an energy dispersive X-ray analyser (EDXA) have confirmed the identity of this mineral. This is apparently the first time that crocoite has been reported in coal. Crocoite usually occurs only in the oxidised zone of lead mineral deposits. The occurrence of this mineral in the Main Seam coal implies that the deposit was exposed to an oxidising environment at some stage, most likely after coalification. Published by Elsevier Science B.V.

  20. Second-Degree Atrioventricular Block Occurring After Tooth Extraction.

    PubMed

    Kamatani, Takaaki; Akizuki, Ayako; Kondo, Seiji; Shirota, Tatsuo

    2016-01-01

    Although cardiac arrhythmias are occasionally associated with dental extractions and dental a