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Sample records for bonariensis pisces atherinopsidae

  1. Genotoxic Effects Induced by Cd(+2), Cr(+6), Cu(+2) in the Gill and Liver of Odontesthes bonariensis (Piscies, Atherinopsidae).

    PubMed

    Gasulla, J; Picco, S J; Carriquiriborde, P; Dulout, F N; Ronco, A E; de Luca, J C

    2016-05-01

    Genotoxic effects of Cd(+2), Cr(+6), and Cu(+2) on the gill and liver of the Argentinean Silverside (Odontesthes bonariensis) were studied using the comet assay and in relation with the metal tissue accumulation. Fish were exposed to three waterborne concentrations of each metal for 2 and 16 days. Genotoxicity was assessed by the single cell gel electrophoresis (comet assay). After 2 days, significant increase of the genetic damage index (GDI) was only observed in the gill of fish exposed to Cr(+6) and Cu(+2), and the LOECs were 2160 nM and 921.1 nM, respectively. The gill LOEC for Cd(+2) by 16 days was 9.4 nM. In the liver, LOECs were obtained only for Cd(+2) and Cr(+6) and were 9.4 and 2160 nM, respectively. The three metals were able to induce genotoxic effects at environmentally relevant concentrations and the gill was the most sensitive organ. PMID:27003804

  2. Global metabolic response in the bile of pejerrey (Odontesthes bonariensis, Pisces) sublethally exposed to the pyrethroid cypermethrin.

    PubMed

    Carriquiriborde, Pedro; Marino, Damián J; Giachero, Gabriela; Castro, Eduardo A; Ronco, Alicia E

    2012-02-01

    The metabolic profile of Odontesthes bonariensis and its global response to the insecticide cypermethrin were studied using HPLC-MS-based metabolomics. Three experiments using either juveniles or adults of O. bonariensis were performed by exposing fish (6, 24, or 96 h) to sublethal concentrations of cypermethrin (5 or 10 μg/L). Metabolic profiling was performed on either whole bile or aqueous and organic extracts. Chromatography was performed using a C18 column and an ACN/H₂O mobile phase. Electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) interfaces were used in positive and negative modes. Full scan MS data were processed using the XCMS software, log-transformed, and analyzed using either regression analysis or principal component analysis (PCA). The highest amount of information (1163 peaks) was yielded by analyzing the whole bile with the ESI⁻ interface. Complementary information, useful for metabolite confirmation, was obtained from the aqueous and organic extracts and using the ESI⁺ and APCI interfaces. The bile metabolic profile of O. bonariensis was characterized by some abundant metabolite ions corresponding with taurine conjugated bile acids, which were useful as reference peaks. A characteristic global metabolic response to cypermethrin was identified in the bile of O. bonariensis. A ten-fold or higher variation in abundance was observed in the whole bile of exposed fish for a small group of peaks (32), and these peaks corresponded to an even smaller number of metabolites (nineteen). Both regression analysis and PCA were useful in identifying those peaks, better explaining differences between exposed and control groups, but slight differences were suggested by each of those methods. Using unsupervised PCA scores, we were able to distinguish organisms from each treatment on the basis of the metabolic changes induced by the cypermethrin, this variability being explained mainly by only one principal component (PC3, 17

  3. Surfing among species, populations and morphotypes: Inferring boundaries between two species of new world silversides (Atherinopsidae).

    PubMed

    González-Castro, Mariano; Rosso, Juan José; Mabragaña, Ezequiel; Díaz de Astarloa, Juan Martín

    2016-01-01

    Atherinopsidae are widespread freshwater and shallow marine fish with singular economic importance. Morphological, genetical and life cycles differences between marine and estuarine populations were already reported in this family, suggesting ongoing speciation. Also, coexistence and interbreeding between closely related species were documented. The aim of this study was to infer boundaries among: (A) Odontesthes bonariensis and O. argentinensis at species level, and intermediate morphs; (B) the population of O. argentinensis of Mar Chiquita Lagoon and its marine conspecifics. To achieve this, we integrated, meristic, Geometrics Morphometrics and DNA Barcode approaches. Four groups were discriminated and subsequently characterized according to their morphological traits, shape and meristic characters. No shared haplotypes between O. bonariensis and O. argentinensis were found. Significative-meristic and body shape differences between the Mar Chiquita and marine individuals of O. argentinensis were found, suggesting they behave as well differentiated populations, or even incipient ecological species. The fact that the Odontesthes morphotypes shared haplotypes with both, O. argentinensis and O. bonariensis, but also possess meristic and morphometric distinctive traits open new questions related to the origin of this morphogroup. PMID:26705969

  4. PISCES Program

    SciTech Connect

    Hirooka, Y.; Conn, R.W.

    1990-09-01

    This report discusses the following topics: PISCES-A facility; PISCES-B facility; PISCES-C facility; fast scanning probes; spectroscopic diagnostics; PISCES laboratory data acquisition system; SEM EDX facilities; vacuum outgassing facility; evaluation of bulk-boronized graphites; chemical sputtering of C-C composites; D-retention in redeposited carbon; TEXTOR-exposed graphite; oxygen plasma reactions with graphite; gaseous divertor simulation; experimental; proof of RF-limiter; H-mode transition by DC-biasing; edge-plasma physics experiments in the CCT-tokamak; and He-spectroscopy for edge-plasma diagnosis.

  5. Main features of the oxidative metabolism in gills and liver of Odontesthes nigricans Richardson (Pisces, Atherinopsidae).

    PubMed

    Lattuca, M E; Malanga, G; Aguilar Hurtado, C; Pérez, A F; Calvo, J; Puntarulo, S

    2009-12-01

    The aim of this work was to study comparatively the oxidative metabolism in gills and liver of a silverside, Odontesthes nigricans, in their natural environment, the Beagle Channel. Oxidative damage to lipids was evaluated by assessing TBARS and lipid radical content, in gills and liver. Gills showed a significantly higher degree of damage than liver. The content of alpha-tocopherol, beta-carotene and catalase activity showed significantly higher values in the liver than in the gills. The ascorbyl radical (A(*)) content showed no significant differences between gills and liver. The ascorbate (AH(-)) content was 12+/-2 and 159+/-28 nmol/mg FW in gills and liver, respectively. Oxidative metabolism at the hydrophilic level was assessed as the ratio A(*)/AH(-). The ratio A(*)/AH(-) was significantly different between organs, (6+/-2)10(-5) and (5+/-2)10(-6), for the gills and the liver, respectively. Both, lipid radical content/alpha-tocopherol content and lipid radical content/beta-carotene content ratios were significantly higher in gills as compared to the values recorded for the liver, suggesting an increased situation of oxidative stress condition in the lipid phase of the gills. Taken as a whole, the O. nigricans liver exhibited a better control of oxidative damage than the gills, allowing minimization of intracellular damage when exposed to environmental stressing conditions. PMID:19706336

  6. PISCES 2 users manual

    NASA Technical Reports Server (NTRS)

    Pratt, Terrence W.

    1987-01-01

    PISCES 2 is a programming environment and set of extensions to Fortran 77 for parallel programming. It is intended to provide a basis for writing programs for scientific and engineering applications on parallel computers in a way that is relatively independent of the particular details of the underlying computer architecture. This user's manual provides a complete description of the PISCES 2 system as it is currently implemented on the 20 processor Flexible FLEX/32 at NASA Langley Research Center.

  7. Two new glycosides from Conyza bonariensis.

    PubMed

    Zahoor, Aqib; Siddiqui, Imran Nafees; Khan, Afsar; Ahmad, Viqar Uddin; Ahmed, Amir; Hassan, Zahid; Khan, Saleha Suleman; Iqbal, Shazia

    2010-07-01

    Studies on Conyza bonariensis (L.) Cronq. led to the isolation of two new glycosides trivially named as erigeside E and F (1-2), along with two new source compounds; benzyl-beta-D-glucopyranoside (3) and 2-phenylethyl-beta-D-glucopyranoside (4). Compounds 1, 3, and 4 are aromatic glycosides, while compound 2 is an alkyl glycoside. Their structures were elucidated through mass spectrometric, and 1D- and 2D-NMR spectroscopic techniques, including 1H NMR, 13C NMR, HMQC, HSQC and HMBC. PMID:20734949

  8. Update on PISCES

    NASA Technical Reports Server (NTRS)

    Pearson, Don; Hamm, Dustin; Kubena, Brian; Weaver, Jonathan K.

    2010-01-01

    An updated version of the Platform Independent Software Components for the Exploration of Space (PISCES) software library is available. A previous version was reported in Library for Developing Spacecraft-Mission-Planning Software (MSC-22983), NASA Tech Briefs, Vol. 25, No. 7 (July 2001), page 52. To recapitulate: This software provides for Web-based, collaborative development of computer programs for planning trajectories and trajectory- related aspects of spacecraft-mission design. The library was built using state-of-the-art object-oriented concepts and software-development methodologies. The components of PISCES include Java-language application programs arranged in a hierarchy of classes that facilitates the reuse of the components. As its full name suggests, the PISCES library affords platform-independence: The Java language makes it possible to use the classes and application programs with a Java virtual machine, which is available in most Web-browser programs. Another advantage is expandability: Object orientation facilitates expansion of the library through creation of a new class. Improvements in the library since the previous version include development of orbital-maneuver- planning and rendezvous-launch-window application programs, enhancement of capabilities for propagation of orbits, and development of a desktop user interface.

  9. Glycosides and xanthine oxidase inhibitors from Conyza bonariensis.

    PubMed

    Kong, L D; Abliz, Z; Zhou, C X; Li, L J; Cheng, C H; Tan, R X

    2001-10-01

    Fractionation of the xanthine oxidase inhibitory methanol extract of Conyza bonariensis afforded three glycosides, in addition to nine known compounds including amyrin, beta-sitostero1 daucosterol, syringic acid 3-hydroxy-5-methoxybenzoic acid, eugenol 4-O-glucopyranoside, and luteolin, apigenin and takakin 8-O-glucuronide. The structures of the glycosides were established by a combination of spectroscopic methods (IR, MS, 1H and 13C NMR, DEPT, COSY, HMQC and HMBC) as 4-hydroxypyridin-3-carboxylic acid 4-O-glucopyranoside, 8-hydroxy-6,7-dihydrolinalool 8-O-glucopyranoside and bonaroside [viz. 1,3,4,12-tetrahydroxy-2-(9-hexadecenoylamino)octadecane 1-O-glucopyranoside]. The in vitro enzyme assay showed that syringic acid and takakin 8-O-glucuronide displayed weak inhibitory activity against xanthine oxidase with IC50 values of 500+/-41 microM and 170+/-12 microM, respectively. PMID:11576616

  10. Promiscuous Speciation with Gene Flow in Silverside Fish Genus Odontesthes (Atheriniformes, Atherinopsidae) from South Western Atlantic Ocean Basins

    PubMed Central

    García, Graciela; Ríos, Néstor; Gutiérrez, Verónica; Varela, Jorge Guerra; Bouza Fernández, Carmen; Pardo, Belén Gómez; Portela, Paulino Martínez

    2014-01-01

    The present paper integrates phylogenetic and population genetics analyses based on mitochondrial and nuclear molecular markers in silversides, genus Odontesthes, from a non-sampled area in the SW Atlantic Ocean to address species discrimination and to define Managements Units for sustainable conservation. All phylogenetic analyses based on the COI mitochondrial gene were consistent to support the monophyly of the genus Odontesthes and to include O. argentinensis, O. perugiae-humensis and some O. bonariensis haplotypes in a basal polytomy conforming a major derivative clade. Microsatellites data revealed somewhat higher genetic variability values in the O. argentinensis-perugia populations than in O. bonariensis and O. perugia-humensis taxa. Contrasting population genetics structuring emerged from mitochondrial and microsatellites analyses in these taxa. Whereas mitochondrial data supported two major groups (O. argentinensis-perugia-humensis vs. O. bonariensis-perugiae-humensis populations), microsatellite data detected three major genetic entities represented by O. bonariensis, O. perugiae-humensis and an admixture of populations belonging to O. argentinensis-perugiae respectively. Therefore, the star COI polytomy in the tree topology involving these taxa could be interpreted by several hypothetic scenarios such as the existence of shared ancestral polymorphisms, incomplete lineage sorting in a radiating speciation process and/or reticulation events. Present findings support that promiscuous and recent contact between incipient species sharing asymmetric gene flow exchanges, blurs taxa boundaries yielding complicated taxonomy and Management Units delimitation in silverside genus Odontesthes from SW Atlantic Ocean basins. PMID:25126842

  11. PISCES: Developing New Design, Materials and Technologies for Sustained

    NASA Technical Reports Server (NTRS)

    Marzwell, Neville I.; Larson, William E.; Duke, Mike; Schowengerdt, Frank

    2008-01-01

    PISCES, the Pacific International Space Center for Exploration Systems. This paper describes the PISCES development plans, particularly in the areas of In-Situ Resource Utilization, Robotics and Education and Outreach.

  12. Glyphosate-resistant hairy fleabane (Conyza bonariensis) Documented in the Central Valley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years poor control of hairy fleabane (Conyza bonariensis) with glyphosate has been reported by growers and pest consultants in some areas of the Central Valley. Since glyphosate-resistance in a related species horseweed (Conyza canadensis) was recently documented in similar locations, we ...

  13. Vulnerability of pejerrey Odontesthes bonariensis populations to climate change in pampean lakes of Argentina.

    PubMed

    Kopprio, G A; Freije, R H; Strüssmann, C A; Kattner, G; Hoffmeyer, M S; Popovich, C A; Lara, R J

    2010-11-01

    The vulnerability of the pejerrey Odontesthes bonariensis population in Lake Chasicó was assessed under different climate change conditions. During the sampling period, the water temperature was adequate for fish reproduction and to sustain an adequate sex ratio. Climate-driven higher temperatures, however, may severely distort population structure and cause drastic reduction or local extinction of stocks. Lake Chasicó can be classified as eutrophic with clear waters and cyanobacteria that regularly cause fish mortality were identified as Nodularia spumigena and Oscillatoria sp. Global warming may strengthen the effects of eutrophication (e.g. toxic blooms or anoxia). Since many Cyanophyta species tolerate higher temperatures better than other algae, toxic blooms could increase. Furthermore, cyanobacteria have low nutritional value and could decouple the low-diversity food web. Lake Chasicó has currently the salinity optimum (c. 20) for the development of the early life-history stages of O. bonariensis. Climate change, however, is likely to amplify the intensity of droughts or inundations. Floods can endanger O. bonariensis development due to its sub-optimal growth at low salinity and droughts could increase lake salinity and also temperature and nutrient concentration. In order to reduce some of the effects of climate change on the O. bonariensis population in Lake Chasicó, integrated basin management based on an eco-hydrological approach is proposed. PMID:21078095

  14. Constitutively Elevated Levels of Putrescine and Putrescine-Generating Enzymes Correlated with Oxidant Stress Resistance in Conyza bonariensis and Wheat.

    PubMed

    Ye, B.; Muller, H. H.; Zhang, J.; Gressel, J.

    1997-12-01

    Oxidant stress resistance in Conyza bonariensis and wheat (Triticum aestivum) has been correlated with high levels of antioxidant enzyme activities. Additionally, external oxidant stresses can increase a plant's levels of the enzymes of polyamine biosynthesis and polyamines, especially putrescine. We investigated the constitutive relationships between putrescine, putrescine-generating enzymes, and oxidant stress resistance in wheat and C. bonariensis. Putrescine was Constitutively elevated (2.5- to 5.7-fold) in 2-week-old-resistant wheat and C. bonariensis biotypes, which correlated with a 10- to 15-fold increase in paraquat oxidant resistance. Arginine and ornithine decarboxylase activities doubled, along with higher putrescine levels in resistant C. bonariensis. The variations in levels of putrescine and arginine and ornithine decarboxylase activities paralleled the constitutive variation of antioxidant enzymes, as well as oxidant resistance. Higher levels of both putrescine and antioxidant enzyme activities occurred during a peak of oxidant resistance at 10 weeks, when paraquat resistance in C. bonariensis plants is >50-fold greater than in the sensitive biotype. Application of 100 [mu]M putrescine can double oxidant-stress resistance in the resistant C. bonariensis. Putrescine may play an important role in contributing to the base level of oxidant resistance found at the nonpeak period. PMID:12223875

  15. Constitutively Elevated Levels of Putrescine and Putrescine-Generating Enzymes Correlated with Oxidant Stress Resistance in Conyza bonariensis and Wheat.

    PubMed Central

    Ye, B.; Muller, H. H.; Zhang, J.; Gressel, J.

    1997-01-01

    Oxidant stress resistance in Conyza bonariensis and wheat (Triticum aestivum) has been correlated with high levels of antioxidant enzyme activities. Additionally, external oxidant stresses can increase a plant's levels of the enzymes of polyamine biosynthesis and polyamines, especially putrescine. We investigated the constitutive relationships between putrescine, putrescine-generating enzymes, and oxidant stress resistance in wheat and C. bonariensis. Putrescine was Constitutively elevated (2.5- to 5.7-fold) in 2-week-old-resistant wheat and C. bonariensis biotypes, which correlated with a 10- to 15-fold increase in paraquat oxidant resistance. Arginine and ornithine decarboxylase activities doubled, along with higher putrescine levels in resistant C. bonariensis. The variations in levels of putrescine and arginine and ornithine decarboxylase activities paralleled the constitutive variation of antioxidant enzymes, as well as oxidant resistance. Higher levels of both putrescine and antioxidant enzyme activities occurred during a peak of oxidant resistance at 10 weeks, when paraquat resistance in C. bonariensis plants is >50-fold greater than in the sensitive biotype. Application of 100 [mu]M putrescine can double oxidant-stress resistance in the resistant C. bonariensis. Putrescine may play an important role in contributing to the base level of oxidant resistance found at the nonpeak period. PMID:12223875

  16. Pisces

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    (the Fishes; abbrev. Psc, gen. Piscium; area 889 sq. deg.) A northern zodiacal constellation which lies between Pegasus and Cetus, and culminates at midnight in late September. Its origin dates back to Babylonian times and it is said to represent Aphrodite, the goddess of love in Greek mythology, and her son Eros, who jumped into the Euphrates to escape from the multi-headed Typhon and were turned...

  17. Planetary In Situ Capillary Electrophoresis System (PISCES)

    NASA Astrophysics Data System (ADS)

    Willis, P. A.; Stockton, A. M.; Mora, M. F.; Cable, M. L.; Bramall, N. E.; Jensen, E. C.; Jiao, H.; Lynch, E.; Mathies, R. A.

    2012-10-01

    We propose to develop PISCES, a 3-kg, 2W, flight-capable microfluidic lab-on-a-chip capillary electrophoresis analyzer capable of ingesting solid, liquid, or gas samples and performing a suite of chemical analyses with parts per trillion sensitivity.

  18. Antioxidant and antibacterial activities of extracts from Conyza bonariensis growing in Yemen.

    PubMed

    Thabit, Riyadh Abdulmajid Saleh; Cheng, Xiang-Rong; Tang, Xue; Sun, Jin; Shi, Yong-Hui; Le, Guo-Wei

    2015-01-01

    This study aims to examine the antioxidant and antibacterial activities and phenolic contents of Conyza bonariensis growing in Yemen. The whole plants of C. bonariensis were ultrasonically extracted by ethanol. The antioxidant activity of the extract was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene bleaching (BCB). The effectiveness of the extract on the growth inhibition of some indicators of foodborne illness bacteria were investigated by agar well diffusion assay. The total phenols (TP), total flavonoids (TF), total tannins (TT), and total anthocyanins (TA) were determined by Folin-Ciocalteu method, aluminium chloride method, Folin and Ciocalteu method, and pH-differential method, respectively. The extract of C. bonariensis possessed TP 144.1 mg/g, TF 143 mg/g, TT 0.99mg/g, and TA 0.97mg 100g, with 94.57% inhibition of DPPH and 92.47% inhibition of BCB, and strong inhibitory effects against tested bacteria, which was approximate to those of peel extract of Punica granatum. PMID:25553691

  19. PisCES: Pis(cine) Community Estimation Software

    EPA Science Inventory

    PisCES predicts a fish community for any NHD-Plus stream reach in the conterminous United States. PisCES utilizes HUC-based distributional information for over 1,000 nature and non-native species obtained from NatureServe, the USGS, and Peterson Field Guide to Freshwater Fishes o...

  20. SPECTROSCOPIC CONFIRMATION OF THE PISCES OVERDENSITY

    SciTech Connect

    Kollmeier, Juna A.; Shectman, Stephen; Thompson, Ian B.; Preston, George W.; Simon, Joshua D.; Crane, Jeffrey D.; Gould, Andrew; Ivezic, Zeljko; Sesar, Branimir

    2009-11-10

    We present spectroscopic confirmation of the 'Pisces Overdensity', also known as 'Structure J', a photometric overdensity of RR Lyrae stars discovered by the Sloan Digital Sky Survey at an estimated photometric distance of approx85 kpc. We measure radial velocities for eight RR Lyrae stars within Pisces. We find that five of the eight stars have heliocentric radial velocities within a narrow range of -87 km s{sup -1} < v{sub r} < -67 km s{sup -1}, suggesting that the photometric overdensity is mainly due to a physically associated system, probably a dwarf galaxy or a disrupted galaxy. Two of the remaining three stars differ from one another by only 9 km s{sup -1}, but it would be premature to identify them as a second system.

  1. PISCES and ALT-II: Juelich PSI papers

    SciTech Connect

    Conn, R.W.; Hirooka, Y.; LaBombard, B.; Moyer, R.; Goebel, D.M.; Leung, W.K.; Nygren, R.E.; Corbett, W.J.; Lehmer, R.; Ra, Y.; Tynan, G.; Dippel, K.H.; Finken, K.H.; Hardkte, A.; Kohlhaas, W.; Wolf, G.; Vandenplas, P.; Messian, M.; Van Oost, G.; Weynants, R.; Franconi, E.; Miyahara, A.; Sagara, A.; Gauster, W.B.; Koski, J.A.; McGrath, R.T.; Watkins, J.G.; Malinowski, M.E.

    1988-08-01

    This publication comprises papers from the PISCES and ALT-II Programs at UCLA which were presented at the International Plasma Surface Interactions Meeting held in Juelich, FRG, on May 2-6, 1988. A list of publications from the PISCES and ALT-II contained in this report are: Deuterium pumping and erosion behavior of selected graphite materials under high flux plasma bombardment in PISCES; Erosion and redeposition behavior of selected NET-candidate materials under high-flux hydrogen, deuterium plasma bombardment in PISCES; Presheath profiles in simulated tokamak edge plasmas; Boundary asymmetries and plasma flow to the ALT-II toroidal belt pump limiter; ALT-II toroidal belt pump limiter performance in TEXTOR; and An in-situ spectroscopic erosion yield measurement with applications to sputtering and surface morphology alterations.

  2. Chemical composition of essential oils from leaves, stems, flower heads and roots of Conyza bonariensis L. from Tunisia.

    PubMed

    Mabrouk, S; Elaissi, A; Ben Jannet, H; Harzallah-Skhiri, F

    2011-01-01

    The essential oils isolated at the flowering stage in spring, summer and autumn of the aerial and underground parts of Conyza bonariensis L. growing in Tunisia were analysed by GC and GC/MS; 143 constituents were identified, and among them 20 were major. The oils of C. bonariensis gathered in spring were rich in matricaria ester (1.2-67.3%), (Z)-nerolidol (0.3-19.9%) and caryophyllene oxide (0.8-14.3%). In the summer samples, the oils of C. bonariensis were rich in matricaria ester (1.6-76.4%), caryophyllene oxide (1.6-22.6%) and (E)-β-farnesene (1.1-22.7%). The main constituents in the autumn samples were matricaria ester (trace to 63.5%), geranyl acetone (0.0-25.3%), trans-α-bergamotene (0.0-24.3%) and limonene (2.7-15.3%). The oils showed significant variation among the seasons. Remarkable differences were found between the constituent percentages of the different studied organs. The C. bonariensis sample from Tunisia was a matricaria ester chemotype and was quite different from the samples of other countries of origin. PMID:21240765

  3. Predation among armored arachnids: Bothriurus bonariensis (Scorpions, Bothriuridae) versus four species of harvestmen (Harvestmen, Gonyleptidae).

    PubMed

    Albín, Andrea; Toscano-Gadea, Carlos A

    2015-12-01

    Natural selection shapes prey-predator relationships and their behavioral adaptations, which seek to maximize capture success in the predator and avoidance in the prey. We tested the ability of adults of the scorpion Bothriurus bonariensis (Bothriuridae) to prey on synchronous and sympatric adults harvestmen of Acanthopachylus aculeatus, Discocyrtus prospicuus, Parampheres bimaculatus and Pachyloides thorellii (Gonyleptidae). In 72.5% of the cases B. bonariensis tried to prey on the harvestmen. The most successful captures occurred in the trials against A. aculeatus and D. prospicuus. In all the successful attacks the scorpions stung the prey between the chelicerae and consumed them, starting by the anterior portion of their bodies. The harvestmen used different defensive strategies such as fleeing before or after contact with the predator, exudating of chemical substances or staying still at the scorpion's touch. When scorpions contacted the chemical substances secreted by the harvestmen, they immediately rubbed the affected appendix against the substrate. However, exudating of chemical substances did not prevent, in any case, predation on the harvestmen. This is the first study showing the ability of scorpions to prey on different species of harvestmen, as well as the capture and defensive behaviors used by the predator and the prey. PMID:26470886

  4. HALO VELOCITY GROUPS IN THE PISCES OVERDENSITY

    SciTech Connect

    Sesar, Branimir; Ivezic, Zeljko; Vivas, A. Katherina; Duffau, Sonia E-mail: zi@u.washington.ed E-mail: sonia.duffau@gmail.co

    2010-07-01

    We report spectroscopic observations of five faint (V {approx} 20) RR Lyrae stars associated with the Pisces overdensity conducted with the Gemini South Telescope. At a heliocentric and galactocentric distance of {approx}80 kpc, this is the most distant substructure in the Galactic halo known to date. We combined our observations with literature data and confirmed that the substructure is composed of two different kinematic groups. The main group contains eight stars and has (V{sub gsr}) = 50 km s{sup -1}, while the second group contains four stars at a velocity of (V{sub gsr}) = -52 km s{sup -1}, where V{sub gsr} is the radial velocity in the galactocentric standard of rest. The metallicity distribution of RR Lyrae stars in the Pisces overdensity is centered on [Fe/H] = -1.5 dex and has a width of 0.3 dex. The new data allowed us to establish that both groups are spatially extended making it very unlikely that they are bound systems, and are more likely to be debris of a tidally disrupted galaxy or galaxies. Due to small sky coverage, it is still unclear whether these groups have the same or different progenitors.

  5. LiPISC: A Lightweight and Flexible Method for Privacy-Aware Intersection Set Computation

    PubMed Central

    Huang, Shiyong; Ren, Yi; Choo, Kim-Kwang Raymond

    2016-01-01

    Privacy-aware intersection set computation (PISC) can be modeled as secure multi-party computation. The basic idea is to compute the intersection of input sets without leaking privacy. Furthermore, PISC should be sufficiently flexible to recommend approximate intersection items. In this paper, we reveal two previously unpublished attacks against PISC, which can be used to reveal and link one input set to another input set, resulting in privacy leakage. We coin these as Set Linkage Attack and Set Reveal Attack. We then present a lightweight and flexible PISC scheme (LiPISC) and prove its security (including against Set Linkage Attack and Set Reveal Attack). PMID:27326763

  6. LiPISC: A Lightweight and Flexible Method for Privacy-Aware Intersection Set Computation.

    PubMed

    Ren, Wei; Huang, Shiyong; Ren, Yi; Choo, Kim-Kwang Raymond

    2016-01-01

    Privacy-aware intersection set computation (PISC) can be modeled as secure multi-party computation. The basic idea is to compute the intersection of input sets without leaking privacy. Furthermore, PISC should be sufficiently flexible to recommend approximate intersection items. In this paper, we reveal two previously unpublished attacks against PISC, which can be used to reveal and link one input set to another input set, resulting in privacy leakage. We coin these as Set Linkage Attack and Set Reveal Attack. We then present a lightweight and flexible PISC scheme (LiPISC) and prove its security (including against Set Linkage Attack and Set Reveal Attack). PMID:27326763

  7. The PISCES 2 parallel programming environment

    NASA Technical Reports Server (NTRS)

    Pratt, Terrence W.

    1987-01-01

    PISCES 2 is a programming environment for scientific and engineering computations on MIMD parallel computers. It is currently implemented on a flexible FLEX/32 at NASA Langley, a 20 processor machine with both shared and local memories. The environment provides an extended Fortran for applications programming, a configuration environment for setting up a run on the parallel machine, and a run-time environment for monitoring and controlling program execution. This paper describes the overall design of the system and its implementation on the FLEX/32. Emphasis is placed on several novel aspects of the design: the use of a carefully defined virtual machine, programmer control of the mapping of virtual machine to actual hardware, forces for medium-granularity parallelism, and windows for parallel distribution of data. Some preliminary measurements of storage use are included.

  8. Chemical composition and biological activity of Conyza bonariensis essential oil collected in Mérida, Venezuela.

    PubMed

    Araujo, Liliana; Moujir, Laila M; Rojas, Janne; Rojas, Luis; Carmona, Juan; Rondón, María

    2013-08-01

    The essential oil from aerial parts of Conyza bonariensis (L) Cronquist collected in Mérida was obtained by hydrodistillation and analysed by GC/MS. The major components were trans-beta-farnesene (37.8%), trans-ocimene (20.7%) and beta-sesquiphellandrene (9.8%). Cytotoxicity assay was also performed with the essential oil against HeLa (cervix carcinoma), A-459 (lung carcinoma) and MCF-7 (breast adenocarcinoma) human cell lines and against normal Vero cells (African green monkey kidney) with IC50 values ranging from 1.4 to 45.8 microg/mL. Additionally, the essential oil presented a significant bactericidal effect against Bacillus cereus, while a moderate activity was observed against Staphylococcus epidermidis and Candida albicans. PMID:24079198

  9. Subcellular energy balance of Odontesthes bonariensis exposed to a glyphosate-based herbicide.

    PubMed

    Menéndez-Helman, Renata J; Miranda, Leandro A; Dos Santos Afonso, Maria; Salibián, Alfredo

    2015-04-01

    Water pollution by agrochemicals is currently one of the most critical problems for the conservation of aquatic ecosystems. Glyphosate [N-(phosphonomethyl) glycine); PMG] is the main broad-spectrum post emergence herbicide used for the control of a wide range of pests in soybean crops. Adenylate energy charge (AEC) reflects the energy balance of the cells, a measure of the energy available from the adenylate pool: adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP). Background adenylates, phosphagens and the AEC index of two year old Odontesthes bonariensis were determined in some tissues by HPLC, and the impact on subcellular energy balance of sublethal glyphosate-based herbicide exposure was analyzed. The doses used were 0 (control tank), 1 or 10mg PMGL(-1), trials were carried out during 15 days. AEC values in brain, liver and muscle from control fish were 0.37 ± 0.02, 0.49 ± 0.05 and 0.56 ± 0.03, respectively (means ± SEM). While brain ATP concentrations were undetectable (hence low values of AEC), the muscle tissue showed the highest concentrations of the more energetic molecules: 0.18 μmole ATP g(-1) and 8 μmole phosphocreatine g(-1) (PCrg(-1)). In the brain, no significant changes were detected in exposed fish compared to controls. Instead, in both the liver and muscle of animals exposed to the highest concentration of the herbicide, significant changes in the AEC (reduction of 26% and 15%, p<0.05) with respect to the control group were determined. Chronic exposure (15 days) of Odontesthes bonariensis to 1 and 10mgL(-1) of formulated glyphosate did not affect brain AEC. However, the highest concentration of the herbicide produced a significant decrease in liver and muscle AEC manifesting adverse sublethal effects on the energy metabolism. These results suggest the usefulness of AEC as a biomarker of fish glyphosate exposure. PMID:25637751

  10. Growth hormone receptors in the atherinid Odontesthes bonariensis: characterization and expression profile after fasting-refeeding and growth hormone administration.

    PubMed

    Botta, P E; Simó, I; Sciara, A A; Arranz, S E

    2016-05-01

    In order to improve the understanding of pejerrey Odontesthes bonariensis, growth hormone (Gh)-insulin-like growth factor-1(Igf1) axis, O. bonariensis growth hormone receptor type 1 (ghr1) and type 2 (ghr2) mRNA sequences were obtained. Both transcripts were ubiquitously expressed except in kidney, encephalon and anterior intestine. Alternative transcripts of both receptors were found in muscle. Interestingly, two different ghr2 transcripts with alternative polyadenylation (APA) sites located in the long 3' untranslated region (UTR-APA) were also found in liver. Hepatic ghr1, ghr2 and insulin-like growth factor type 1 (igf1) transcript levels were examined under two different metabolic conditions. In the first experimental condition, fish were fasted for 2 weeks and then re-fed for another 2 weeks. Despite igf1 mRNA relative expression did not show significant differences under the experimental period of time examined, both ghr transcripts decreased their expression levels after the fasting period and returned to their control levels after re-feeding. In the second treatment, recombinant O. bonariensis growth hormone (r-pjGh) was orally administered once a week. After 4 weeks of treatment, liver igf1, ghr1 and ghr2 mRNA relative expression increased (13, 4·5 and 2·1 fold, P < 0·05) compared to control values. These results add novel information to the growth hormone-insulin-like growth factor system in teleosts. PMID:27097742

  11. Do freshwater fishes diversify faster than marine fishes? A test using state-dependent diversification analyses and molecular phylogenetics of new world silversides (atherinopsidae).

    PubMed

    Bloom, Devin D; Weir, Jason T; Piller, Kyle R; Lovejoy, Nathan R

    2013-07-01

    Freshwater habitats make up only ∼0.01% of available aquatic habitat and yet harbor 40% of all fish species, whereas marine habitats comprise >99% of available aquatic habitat and have only 60% of fish species. One possible explanation for this pattern is that diversification rates are higher in freshwater habitats than in marine habitats. We investigated diversification in marine and freshwater lineages in the New World silverside fish clade Menidiinae (Teleostei, Atherinopsidae). Using a time-calibrated phylogeny and a state-dependent speciation-extinction framework, we determined the frequency and timing of habitat transitions in Menidiinae and tested for differences in diversification parameters between marine and freshwater lineages. We found that Menidiinae is an ancestrally marine lineage that independently colonized freshwater habitats four times followed by three reversals to the marine environment. Our state-dependent diversification analyses showed that freshwater lineages have higher speciation and extinction rates than marine lineages. Net diversification rates were higher (but not significant) in freshwater than marine environments. The marine lineage-through time (LTT) plot shows constant accumulation, suggesting that ecological limits to clade growth have not slowed diversification in marine lineages. Freshwater lineages exhibited an upturn near the recent in their LTT plot, which is consistent with our estimates of high background extinction rates. All sequence data are currently being archived on Genbank and phylogenetic trees archived on Treebase. PMID:23815658

  12. Methods for design and evaluation of parallel computating systems (The PISCES project)

    NASA Technical Reports Server (NTRS)

    Pratt, Terrence W.; Wise, Robert; Haught, Mary JO

    1989-01-01

    The PISCES project started in 1984 under the sponsorship of the NASA Computational Structural Mechanics (CSM) program. A PISCES 1 programming environment and parallel FORTRAN were implemented in 1984 for the DEC VAX (using UNIX processes to simulate parallel processes). This system was used for experimentation with parallel programs for scientific applications and AI (dynamic scene analysis) applications. PISCES 1 was ported to a network of Apollo workstations by N. Fitzgerald.

  13. PISCES program plasma-surface interactions research: Summary of research, 1988--1989

    SciTech Connect

    Not Available

    1989-05-01

    This paper discusses the following about the Pisces program: Major objectives of the program; Staff in the PISCES program at UCLA; Highlights in the program; Collaborations with other institutions; PISCES-A facility; PISCES-B facility; Fast scanning Langmuir probe; Omegatron mass spectrometer; Spectroscopic diagnostics; Data acquisition system; Redeposition effect on carbon chemical erosion; Erosion of carbon tokamakium from TFTR; Effect of boron-doping on carbon chemical erosion; Radiation enhanced sublimation of carbon; Surface analysis of TEXTOR titles; Spectroscopic analysis of carbon impurities; Biased limiter and divertor; Biased divertor channel; Gaseous divertor experiments; Presheath profile measurements; Particle transport in CCT tokamak; and Biased divertor experiments in CCT.

  14. Is the Invasive Species Listronotus bonariensis (Kuschel) (Coleoptera: Curculionidae) (Argentine Stem Weevil) a Threat to New Zealand Natural Grassland Ecosystems?

    PubMed Central

    Barratt, Barbara I. P.; Barton, Diane M.; Philip, Bruce A.; Ferguson, Colin M.; Goldson, Stephen L.

    2016-01-01

    Listronotus bonariensis (Argentine stem weevil) is a stem-boring weevil that has become a major pasture pest in New Zealand, and cool climate turf grass in Australia. This species is also frequently found in native tussock grassland in New Zealand. Laboratory and field trials were established to determine the risk posed to both seedlings and established plants of three native grass species compared to what happens with a common host of this species, hybrid ryegrass (L. perenne X L. multiflorum). Adult weevil feeding damage scores were higher on Poa colensoi and Festuca novae-zelandiae than Chionochloa rigida. Oviposition was lower on P. colensoi than hybrid ryegrass, and no eggs were laid on F. novae-zelandiae. In field trials using the same four species established as spaced plants L. bonariensis laid more eggs per tiller in ryegrass in a low altitude pasture site than in ryegrass in a higher altitude site. No eggs were found on the three native grass species at the tussock sites, and only low numbers were found on other grasses at the low altitude pasture site. Despite this, numbers of adult weevils were extracted from the plants in the field trials. These may have comprised survivors of the original weevils added to the plants, together with new generation weevils that had emerged during the experiment. Irrespective, higher numbers were recovered from the tussock site plants than from those from the pasture site. It was concluded that L. bonariensis is likely to have little overall impact, but a greater impact on native grass seedling survival than on established plants. PMID:27507979

  15. PISCES: A "Stepping Stone" to International Space Exploration and Development

    NASA Technical Reports Server (NTRS)

    Howell, Joe T.; Henley, Mark W.; Schowengerdt, Frank

    2007-01-01

    The Pacific International Space Center for Exploration Systems (PISCES) was initiated by the Japan/US Science, Technology and Space Application Programs (JUSTSAP) to advance research and education in space exploration technology and systems working closely with the State of Hawaii. Hawaii has a heritage with space exploration including the training of Apollo astronauts and testing of lunar rover systems in some of the most realistic terrestrial sites available. The high altitude dry environment with greater solar insolation, and the dry lunar regolith-like volcanic ash and cratered terrain make Hawaiian sites ideal to support, international space exploration technology development, demonstration, education and training. This paper will summarize development and roles of PISCES in lunar surface analogs, simulations, technology demonstrations, research and training for space exploration technology and systems.

  16. Cephalic morphological variation in freshwater silversides Odontesthes hatcheri and Odontesthes bonariensis in Patagonia: introgression and ecological relationships.

    PubMed

    Crichigno, S; Conte-Grand, C; Battini, M; Cussac, V

    2013-09-01

    Based on geometric morphometrics and discriminant analysis, the percentage of silverside Odontesthes hatcheri and Odontesthes bonariensis individuals identified by a taxonomic key and misclassified by discriminant analysis was obtained and a negative correlation between the percentage of misclassified individuals of O. hatcheri and the distance to the nearest hatchery stocking silversides was found, suggesting a genetic introgression. Morphological analyses between species, between populations and within populations pointed to the same anatomical structures, suggesting a nested variation related to environmental cues such as availability of littoral shelter. The dependence between the cephalic morphology of O. hatcheri and body size would be in agreement with the trophic niche shifts of the species. Introgression adds a new threat to the already observed decline of populations of O. hatcheri and suggests that this species deserves particular consideration in terms of conservation guidelines. PMID:23991873

  17. The Shiny Cowbird, Molothrus bonariensis (Gmelin, 1789) (Aves: Icteridae), at 2,800 m asl in Quito, Ecuador

    PubMed Central

    Pinto, C. Miguel; Carrión, Juan Manuel; Jarrín-E, Rubén D.; Poveda, Cristian; de Vries, Tjitte

    2016-01-01

    Abstract Background The Shiny Cowbird, Molothrus bonariensis Gmelin, 1789, is a brood parasite of hundreds of small-bodied birds that is native to South American lowlands. Within the last 100 years this species has been expanding its range throughout the Caribbean, towards North America, but has rarely been seen above 2,000 m asl. New information Here, we present records of Shiny Cowbirds in Quito, a city located 2,800 m above sea level that harbors a bird community typical of the Andean valleys. We found two juvenile individuals parasitizing two different pairs of Rufous-collared Sparrow (Zonotrichia capensis Müller, 1776). This report constitutes an altitudinal range expansion of reproductive populations of ca. 500m, which may have beenprompted by anthropogenic disturbance. PMID:27226760

  18. Planetary Basalt Construction of a Launch/Landing Pad - PISCES Project Update

    NASA Astrophysics Data System (ADS)

    Kelso, R. M.

    2015-10-01

    Provide a briefing on the progress of a joint project between the PISCES and NASA to develop and demonstrate technologies associated with planetary robotic construction using basalt: called “Additive Construction with Mobile Emplacement” (ACME).

  19. Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES) for WFIRST/AFTA

    NASA Technical Reports Server (NTRS)

    Gong, Qian; McElwain, Michael; Greeley, Bradford; Grammer, Bryan; Marx, Catherine; Memarsadeghi, Nargess; Hilton, George; Perrin, Marshall; Sayson, Llop; Domingo, Jorge; Stapelfeldt, Karl

    2015-01-01

    Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES) is a prototype lenslet array based integral field spectrometer (IFS) designed for high contrast imaging of extrasolar planets. PISCES will be used to advance the technology readiness of the high contrast IFS baselined on the Wide-Field InfraRed Survey TelescopeAstrophysics Focused Telescope Assets (WFIRSTAFTA) coronagraph instrument. PISCES will be integrated into the high contrast imaging testbed (HCIT) at the Jet Propulsion Laboratory and will work with both the Hybrid Lyot Coronagraph (HLC) and the Shaped Pupil Coronagraph (SPC). We will present the PISCES optical design, including the similarities and differences of lenslet based IFSs to normal spectrometers, the trade-off between a refractive design and reflective design, as well as the compatibility to upgrade from the current 1k x 1k detector array to 4k x 4k detector array. The optical analysis, alignment plan, and mechanical design of the instrument will be discussed.

  20. Partial replacement of barley grain and soybean meal by fleabane (Conyza bonariensis) in diets of growing Awassi lambs.

    PubMed

    Abo Omar, J M; Omar, M

    2012-07-01

    Effects of partial substitution of barley grain and soybean meal with fleabane (FB) Conyza bonariensis on growth performances and body compositions of 24 male local Awassi lambs were studied. All lambs were male with an average BW of 20.3 kg (s.d. = 2.0 kg) at the beginning of the experiment. Animals were randomly divided into four groups of six lambs each. Lambs in each group received individually their cereal-soybean-based total mixed rations with levels of FB: 0, 50, 100 and 150 g/kg dry matter (DM) diet, which replaced similar values of barley and soybean meal. All rations were isonitrogenous and isocaloric. The fattening experiment lasted 9 weeks, after which all lambs were slaughtered. The composition of nutrients in the C. bonariensis were 89.6%, 15.0%, 28.0%, 30.0% and 10% for organic matter, CP, NDF, ADF and lignin, respectively. At the end of the experiment, lambs fed 100 and 150 g FB/kg DM diets gained more weight (P < 0.05) than those fed the control and 50 g FB/kg DM diets. The DM intake was lower in lambs fed the highest level of FB compared with intakes of lambs in other treatments. Diet content of FB had significant effect (P < 0.05) on weights of empty body, carcass, gut and external (hide, head and feet) among all animals. However, FB had no effects on lambs' thoracic organs (lungs and heart) and liver. Muscle, bone, omental and mesenteric fat, subcutaneous, intermuscular, pelvic and kidney fat weights (g/kg empty BW) were not affected by FB feeding. Carcass fat was decreased (P < 0.05) by the increase of FB. Total body fat was the same in all animals of the experiment. PMID:23031470

  1. Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES) for WFIRST/AFTA

    NASA Technical Reports Server (NTRS)

    Gong, Qian; Mcelwain, Michael; Greeley, Bradford; Grammer, Bryan; Marx, Catherine; Memarsadeghi, Nargess; Stapelfeldt, Karl; Hilton, George; Sayson, Jorge Llop; Perrin, Marshall; Demer, Richard; Tang, Hong; Kern, Brian; Ferdosi, Janan

    2015-01-01

    Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES) is a lenslet array based integral field spectrometer (IFS) designed for high contrast imaging of extrasolar planets. PISCES will be used to advance the technology readiness of the high contrast IFS baselined on the Wide-Field InfraRed Survey Telescope/Astrophysics Focused Telescope Assets (WFIRST/AFTA) coronagraph instrument. PISCES will be integrated into the high contrast imaging testbed (HCIT) at the Jet Propulsion Laboratory and will work with both the Hybrid Lyot Coronagraph (HLC) and the Shaped Pupil Coronagraph (SPC) cofigurations. We discuss why the lenslet array based IFS is selected for PISCES. We present the PISCES optical design, including the similarities and differences of lenslet based IFSs to normal spectrometers, the trade-off between a refractive design and reflective design, as well as the specific function of our pinhole mask on the back surface of the lenslet array to further suppress star light introduced speckles. The optical analysis, alignment plan, and mechanical design of the instrument will be discussed.

  2. Prototype imaging spectrograph for coronagraphic exoplanet studies (PISCES) for WFIRST/AFTA

    NASA Astrophysics Data System (ADS)

    Gong, Qian; McElwain, Michael; Greeley, Bradford; Grammer, Bryan; Marx, Catherine; Memarsadeghi, Nargess; Stapelfeldt, Karl; Hilton, George; Llop Sayson, Jorge; Perrin, Marshall; Demers, Richard; Tang, Hong; Kern, Brian; Ferdosi, Janan

    2015-09-01

    Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES) is a lenslet array based integral field spectrometer (IFS) designed for high contrast imaging of extrasolar planets. PISCES will be used to advance the technology readiness of the high contrast IFS baselined on the Wide-Field InfraRed Survey Telescope/Astrophysics Focused Telescope Assets (WFIRST-AFTA) coronagraph instrument. PISCES will be integrated into the high contrast imaging testbed (HCIT) at the Jet Propulsion Laboratory (JPL) and will work with both the Hybrid Lyot Coronagraph (HLC) and the Shaped Pupil Coronagraph (SPC) configurations. We discuss why the lenslet array based IFS was selected for PISCES. We present the PISCES optical design, including the similarities and differences of lenslet based IFSs to normal spectrometers, the trade-off between a refractive design and reflective design, as well as the specific function of our pinhole mask on the back surface of the lenslet array to reduce the diffraction from the edge of the lenslets. The optical analysis, alignment plan, and mechanical design of the instrument will be discussed.

  3. Increased Tolerance to Photoinhibitory Light in Paraquat-Resistant Conyza bonariensis Measured by Photoacoustic Spectroscopy and 14CO2-Fixation

    PubMed Central

    Jansen, Marcel A. K.; Shaaltiel, Yoseph; Kazzes, Dror; Canaani, Ora; Malkin, Shmuel; Gressel, Jonathan

    1989-01-01

    Tolerance to photoinhibition was compared between a paraquat-resistant and a sensitive biotype of Conyza bonariensis (L.). Cronq. Photoinhibitory damage was measured as a decrease in oxygen evolution or energy storage using photoacoustic spectroscopy, or as a decrease of 14CO2-fixation. Prior to exposure to high fluence rates, both biotypes had similar quantum yields of oxygen evolution and energy storage. After exposure to high intensity light, the resistant biotype continued to evolve oxygen and to store energy with a high quantum yield while both energy storage and oxygen evolution were severely reduced in the sensitive biotype. CO2-fixation was less rapidly inhibited in the resistant biotype compared to the sensitive one. The data show that the paraquat resistant biotype with its high constitutive levels of the chloroplast localized enzymes of the oxygen detoxification pathway, is also partially protected from photoinhibition. This supports the theory that an enhanced radical scavenging system can give temporary protection against photooxidative damage from a variety of sources. PMID:16667129

  4. Increased Tolerance to Photoinhibitory Light in Paraquat-Resistant Conyza bonariensis Measured by Photoacoustic Spectroscopy and CO(2)-Fixation.

    PubMed

    Jansen, M A; Shaaltiel, Y; Kazzes, D; Canaani, O; Malkin, S; Gressel, J

    1989-11-01

    Tolerance to photoinhibition was compared between a paraquat-resistant and a sensitive biotype of Conyza bonariensis (L.). Cronq. Photoinhibitory damage was measured as a decrease in oxygen evolution or energy storage using photoacoustic spectroscopy, or as a decrease of (14)CO(2)-fixation. Prior to exposure to high fluence rates, both biotypes had similar quantum yields of oxygen evolution and energy storage. After exposure to high intensity light, the resistant biotype continued to evolve oxygen and to store energy with a high quantum yield while both energy storage and oxygen evolution were severely reduced in the sensitive biotype. CO(2)-fixation was less rapidly inhibited in the resistant biotype compared to the sensitive one. The data show that the paraquat resistant biotype with its high constitutive levels of the chloroplast localized enzymes of the oxygen detoxification pathway, is also partially protected from photoinhibition. This supports the theory that an enhanced radical scavenging system can give temporary protection against photooxidative damage from a variety of sources. PMID:16667129

  5. Potential human health risks from metals and As via Odontesthes bonariensis consumption and ecological risk assessments in a eutrophic lake.

    PubMed

    Monferran, Magdalena V; Garnero, Paola Lorena; Wunderlin, Daniel A; Angeles Bistoni, María de Los

    2016-07-01

    The concentration of Al, Cr, Fe, Mn, Ni, Cu, Zn, Hg, Sr, Mo, Ag, Cd, Pb and As was analyzed in water, sediment, and muscle of Odontesthes bonariensis from the eutrophic San Roque Lake (Córdoba-Argentina). The monitoring campaign was performed during the wet, dry and intermediate season. The concentration of Cr, Fe, Pb, Zn, Al and Cd in water exceeded the limits considered as hazardous for aquatic life. The highest metal concentrations were observed in sediment, intermediate concentrations, in fish muscle, and the lowest in water, with the exception of Cr, Zn, As and Hg, which were the highest in fish muscle. Potential ecological risk analysis of heavy metal concentrations in sediment indicated that the San Roque Lake posed a low ecological risk in all sampling periods. The target hazard quotients (THQs) and carcinogenic risk (CR) for individual metals showed that As in muscle was particularly hazardous, posing a potential risk for fishermen and the general population during all sampling periods. Hg poses a potential risk for fishermen only in the intermediate season. It is important to highlight that none of these two elements exceeded the limits considered as hazardous for aquatic life in water and sediment. This result proves the importance of performing measurements of contaminants, in both abiotic and biotic compartments, to assess the quality of food resources. These results suggest that the consumption of this fish species from this reservoir is not completely safe for human health. PMID:27060257

  6. Photo-induced biosynthesis of silver nanoparticles using aqueous extract of Erigeron bonariensis and its catalytic activity against Acridine Orange.

    PubMed

    Kumar, Vijay; Singh, Devendra K; Mohan, Sweta; Hasan, Syed Hadi

    2016-02-01

    The green synthesis of silver nanoparticles (AgNPs) has reduced the pollution load in the environment to a greater extent by avoiding the use of hazardous chemicals. In the present work we have developed an ecofriendly and zero cost approach for the green synthesis of more stable and spherical AgNPs using aqueous extract of Erigeron bonariensis (AEE) which act as both reducing and stabilizing agent. The reaction of AEE and AgNO3 was carried out in direct sunlight for the instant biosynthesis of AgNPs within minutes. The biosynthesis was monitored by UV-vis spectroscopy which exhibited a sharp SPR band at 442 nm and 435 nm after 5 and 35 min of sunlight exposure. The optimum conditions for biosynthesis of AgNPs were found to be 2.5mM AgNO3 concentration, 1.5% (v/v) of AEE inoculum dose and 35 min of sunlight exposure. Presence of spherical AgNPs with average size 13 nm was confirmed by SEM and TEM analysis. The XRD and SAED analysis confirmed the crystalline nature of the AgNPs where the Bragg's diffraction pattern at (111), (200), (220) and (311) corresponded to face centered cubic crystal lattice of metallic silver. The average roughness of the synthesized AgNPs was 3.21 nm which was confirmed by AFM analysis. FTIR analysis was recorded between 4000 and 400 cm(-1) which confirmed the involvement of various functional groups in the synthesis of AgNPs. The AgNPs thus obtained showed catalytic activity towards degradation of Acridine Orange (AO) without involvement of any hazardous reducing agent. The concentration dependent catalytic activity of the synthesized AgNPs was also monitored using 1, 2 and 3 mL of silver colloids and was found that the degradation of AO followed pseudo first-order kinetics. PMID:26734999

  7. KINEMATIC DISCOVERY OF A STELLAR STREAM LOCATED IN PISCES

    SciTech Connect

    Martin, Charles; Carlin, Jeffrey L.; Newberg, Heidi Jo; Grillmair, Carl

    2013-03-10

    We report the kinematic discovery of the Pisces Stellar Stream (PSS), at Galactic longitude l Almost-Equal-To 135 Degree-Sign and -39 Degree-Sign < b < -36 Degree-Sign . We originally identified this halo substructure from velocities of red giant branch stars in the Sloan Digital Sky Survey (SDSS) Data Release 8, and confirmed its presence in turnoff stars from SDSS photometric data. The PSS is a narrow, kinematically cold tidal stream, with {sigma}{sub v,0} Almost-Equal-To 8 km s{sup -1}. Its metallicity is [Fe/H] Almost-Equal-To -2.2, with {approx}0.3 dex dispersion. The color-magnitude signature of the stream turnoff, combined with our measured metallicity, places the PSS at a distance of 35 {+-} 3 kpc. The PSS is the same as the previously announced ''Triangulum stream'' and part of the proposed ''stream a''. We rule out an association of the PSS with other previously known Milky Way substructures in the same region of the sky.

  8. An Overview of Recent PISCES Program PMI Results

    NASA Astrophysics Data System (ADS)

    Tynan, George; Doerner, Russell; Abe, Shota; Baldwin, Matthew; Barton, Joseph; Chen, Renkun; Gosselin, Jordan; Hollmann, Eric; Nishijima, Daisuke; Simmonds, Michael; Wang, Yong; Yu, Jonathan

    2015-11-01

    The PISCES Program is focused on fundamental PMI studies of Be and W-based solid plasma facing components under steady-state and transient conditions. We will show results from studies in W, Be and mixed W-Be material systems. Topics of investigation include formation of near-surface nanobubbles from He plasma ion implantation, growth of W-fuzz from these bubbles in steady-state and transient conditions, D retention in Be and W and development of a D-retention model for both H/D isotope exchange and displacement damage experiments. Initial studies of PMI in displacement damaged W are also presented, showing the effect of damage and exposure temperature on D retention, D diffusion, W thermal conductivity. Be-based results include morphology evolution under high plasma flux exposure, Be erosion mechanisms, and retention in Be-based materials. Future plans and connections to fusion energy system requirements will be discussed. This work supported by grant DE-FG02-07ER54912.

  9. Understanding pain and improving management of sickle cell disease: the PiSCES study.

    PubMed Central

    Smith, Wally R.; Bovbjerg, Viktor E.; Penberthy, Lynne T.; McClish, Donna K.; Levenson, James L.; Roberts, John D.; Gil, Karen; Roseff, Susan D.; Aisiku, Imoigele P.

    2005-01-01

    Until recent decades, sickle cell disease (SCD) was associated with recurrent, disabling pain, organ failure and death in childhood or early adulthood. SCD treatment advances have now decreased pain and prolonged survival, but episodic or chronic pain may still require substantial analgesic use and frequent hospitalization for pain episodes. This pain is poorly characterized and often poorly treated. Adult patients may face barriers to comprehensive SCD care, stigmatization of their care-seeking behavior by providers and lack of family support, forcing them into maladaptive coping strategies. The Pain in Sickle Cell Epidemiology Study (PiSCES) attempts to develop and validate a biopsychosocial model of SCD pain, pain response and healthcare utilization in a large, multisite adult cohort. PiSCES participants complete a baseline survey and six months of daily pain diaries in which they record levels of SCD-related pain and related disability and distress as well as responses to pain (e.g., medication use, hospital visits). PiSCES will advance methods of measuring pain and pain response in SCD by better describing home-managed as well as provider-managed pain. PiSCES will assess the relative contributions of biological (disease-related), psychosocial and environmental (readiness to utilize) factors to overall pain and pain response in SCD, suggesting targets for biobehavioral interventions over time. Importantly, PiSCES will also identify "triggers" of SCD pain episodes and healthcare utilization in the moment of pain, suggesting targets for timely care that mutes pain episodes. Images Figure 1 Figure 2 PMID:15712781

  10. Trophic ecomorphology of Siluriformes (Pisces, Osteichthyes) from a tropical stream.

    PubMed

    Pagotto, J P A; Goulart, E; Oliveira, E F; Yamamura, C B

    2011-05-01

    The present study analysed the relationship between morphology and trophic structure of Siluriformes (Pisces, Osteichthyes) from the Caracu Stream (22º 45' S and 53º 15' W), a tributary of the Paraná River (Brazil). Sampling was carried out at three sites using electrofishing, and two species of Loricariidae and four of Heptapteridae were obtained. A cluster analysis revealed the presence of three trophic guilds (detritivores, insectivores and omnivores). Principal components analysis demonstrated the segregation of two ecomorphotypes: at one extreme there were the detritivores (Loricariidae) with morphological structures that are fundamental in allowing them to fix themselves to substrates characterised by rushing torrents, thus permitting them to graze on the detritus and organic materials encrusted on the substrate; at the other extreme of the gradient there were the insectivores and omnivores (Heptapteridae), with morphological characteristics that promote superior performance in the exploitation of structurally complex habitats with low current velocity, colonised by insects and plants. Canonical discriminant analysis revealed an ecomorphological divergence between insectivores, which have morphological structures that permit them to capture prey in small spaces among rocks, and omnivores, which have a more compressed body and tend to explore food items deposited in marginal backwater zones. Mantel tests showed that trophic structure was significantly related to the body shape of a species, independently of the phylogenetic history, indicating that, in this case, there was an ecomorphotype for each trophic guild. Therefore, the present study demonstrated that the Siluriformes of the Caracu Stream were ecomorphologically structured and that morphology can be applied as an additional tool in predicting the trophic structure of this group. PMID:21755165

  11. Assessment of persistent organic pollutants accumulation and lipid peroxidation in two reproductive stages of wild silverside (Odontesthes bonariensis).

    PubMed

    Barni, María Florencia Silva; Gonzalez, Mariana; Miglioranza, Karina S B

    2014-01-01

    Persistent organic pollutants (POPs) in streamwater can sometimes exceed the guidelines values reported for biota and human protection in watersheds with intensive agriculture. Oxidative stress and cytotoxicity are some of the markers of exposure to POPs in fish. Accumulation of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) as well as lipid peroxidation (LPO) was assessed in wild silverside (Odontesthes bonariensis) from maturation and pre-spawning stages sampled in a typical soybean growing area. Pollutants were quantified by gas chromatography with electron capture detection and LPO by the method of thiobarbituric acid reactive substances. Concentrations of POPs were in the following order: OCPs>PCBs>PBDEs in all organs and stages. Liver, gills and gonads had the highest OCP concentrations in both sexes and stages with a predominance of endosulfan in all samples. Matured individuals, sampled after endosulfan application period, showed higher endosulfan concentrations than pre-spawning individuals. The predominance of endosulfan sulfate could be due to direct uptake from diet and water column, as well as to the metabolism of the parent compounds in fish. The prevalence of p,p'-DDE in liver would also reflect both the direct uptake and the metabolic transformation of p,p'-DDT to p,p'-DDE by fish. The highest levels of PBDEs and PCBs were found in gills and brain of both stages of growth. The pattern BDE-47>BDE-100 in all samples corresponds to pentaBDE exposure. In the case of PCBs, penta (#101 and 110) and hexa-CB congeners (#153 and 138) dominated in the maturation stages and tri (#18) and tetra-CB (#44 and 52) in pre-spawning stages, suggesting biotransformation or preferential accumulation of heavier congeners during gonadal development. Differences in LPO levels in ovaries were associated with growth dilution and reproductive stage. Differences in LPO levels in gills were related with pesticide

  12. Effects of estradiol and ethinylestradiol on sperm quality, fertilization, and embryo-larval survival of pejerrey fish (Odontesthes bonariensis).

    PubMed

    Gárriz, Ángela; Menéndez-Helman, Renata J; Miranda, Leandro A

    2015-10-01

    17β-Estradiol (E2) and synthetic 17α-Ethinylestradiol (EE2) are estrogenic compounds present in surface waters as a consequence of municipal sewage discharges. The aim of this study was to evaluate the effects of E2, EE2 and its mixtures on different reproductive parameters and embryo-larval survival in pejerrey fish (Odontesthes bonariensis). In order to analyze the effect of these compounds on sperm quality, fertilization%, embryo-larval survival (%), and the point of no return (PNR), different assays were performed using concentrations 175, 350, 700 and 1400 ng/L of E2; 22.5, 45, 90 and 180 ng/L of EE2 and mixtures M1 (175 E2+22.5 EE2, ng/L), M2 (350 E2+45 EE2, ng/L), M3 (700 E2+90 EE2, ng/L) and M4 (1400 E2+180 EE2 ng/L). No significant differences in motility parameters were observed between E2 and EE2 treatments and the control group. However, a significant decrease in motility% was recorded for all mixtures tested compared with the control samples. For fertilization%, only sperm activated with M4 showed a significant decrease compared with the control group. In the case of embryo survival, there was only a significant decrease in the highest concentration of EE2 compared with the control group. For the mixtures, M3 is the one that had the most adverse effect on embryo survival. In larval survival, there was a significant decrease in concentration 175 and 700 ng/L of E2 compared with the control group. In EE2 treatments, the ones with a significant reduction in larval survival were concentration 45 and 90 ng/L. And for the mixture treatments, M1, M3 and M4 had a significantly lower larval survival than the control group. In comparison to other treatments, M1 demonstrated a significant difference in PNR when compared with the control group. The results obtained demonstrated that the exposure to mixtures of E2 and EE2 affected fish sperm motility, fertilization% and, embryo and larval survival even at relevant environmental concentrations highlighting the

  13. The PISCES Project: How Teacher-Scientist Partners can Enhance Elementary Science Instruction

    NASA Astrophysics Data System (ADS)

    Reif, C.; Oechel, W.

    2003-12-01

    The PISCES Project (Partnerships Involving the Scientific Community in Elementary Schools www.sdsa.org/pisces) is an innovative program that brings high quality standards-based elementary science curriculum and hands-on laboratory materials into San Diego County's classrooms. The project is funded by the NSF Graduate Teaching Fellows in K-12 Education (GK-12) program. The project was designed and is administered through cooperation among faculty at San Diego State University and the Science Department of the San Diego County Office of Education. Undergraduate and graduate students enrolled in science programs in San Diego area universities including San Diego State University, California State University San Marcos, and University of California San Diego partner with elementary school teachers. Through this partnership, the scientist brings scientific expertise to the classroom while the teacher delivers the lesson using current pedagogic methods. This is accomplished during a 3 month partnership in which the scientist joins the teacher in the classroom a few days each week to complete professional kit-based curriculum such as that available from FOSS (Full Option Science System) and STC (Science and Technology for Children). The teachers remain in the program for two years during which they have continuous access to the kit-based curriculum as well as two to three partnership cycles. Teachers receive assistance outside of the classroom as well attending professional development institutes three times a year to establish and maintain effective science teaching methods. The San Diego Science Alliance and other community and industry supporters provide the additionalfunding necessary to provide this teacher professional development Currenty, PISCES is present in over 40 schools and is able to provide partnerships to over 100 classrooms each year. In addition to the work done in San Diego, the project has expanded to Barrow, Alaska with plans to expand to La Paz

  14. Spectroscopic Confirmation of the Dwarf Galaxies Hydra II and Pisces II and the Globular Cluster Laevens 1

    NASA Astrophysics Data System (ADS)

    Kirby, Evan N.; Simon, Joshua D.; Cohen, Judith G.

    2015-09-01

    We present Keck/DEIMOS spectroscopy of stars in the recently discovered Milky Way satellites Hydra II, Pisces II, and Laevens 1. We measured a velocity dispersion of {5.4}-2.4+3.6 km s-1 for Pisces II, but we did not resolve the velocity dispersions of Hydra II or Laevens 1. We marginally resolved the metallicity dispersions of Hydra II and Pisces II but not Laevens 1. Furthermore, Hydra II and Pisces II obey the luminosity-metallicity relation for Milky Way dwarf galaxies (< [{Fe}/{{H}}]> =-2.02+/- 0.08 and -2.45+/- 0.07, respectively), whereas Laevens 1 does not (< [{Fe}/{{H}}]> =-1.68+/- 0.05). The kinematic and chemical properties suggest that Hydra II and Pisces II are dwarf galaxies, and Laevens 1 is a globular cluster. We determined that two of the previously observed blue stars near the center of Laevens 1 are not members of the cluster. A third blue star has ambiguous membership. Hydra II has a radial velocity < {v}{helio}> =303.1+/- 1.4 km s-1, similar to the leading arm of the Magellanic stream. The mass-to-light ratio for Pisces II is {370}-240+310 {M}⊙ /{L}⊙ . It is not among the most dark matter-dominated dwarf galaxies, but it is still worthy of inclusion in the search for gamma-rays from dark matter self-annihilation. The data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

  15. Feeding habits of the bluemouth, Helicolenus dactylopterus dactylopterus (Delaroche, 1809) (Pisces: Sebastidae) in the Portuguese coast

    NASA Astrophysics Data System (ADS)

    Neves, Ana; Sequeira, Vera; Paiva, Rafaela Barros; Vieira, Ana Rita; Gordo, Leonel Serrano

    2012-06-01

    In order to investigate the feeding habits of Helicolenus dactylopterus dactylopterus along the continental Portuguese coast, a total of 619 individuals were sampled of which 60% contained food in their stomach and 35% had more than one prey item. Among the 81 prey items that were identified in the stomachs, benthic and benthopelagic prey prevail on this species diet. Acantephyra sp, Pasiphaea sp, mysidacea, and teleostei n.i. were the prey with the higher percent index of relative importance (%IRI) value. Three length groups (5-20 cm, 21-27 cm, and 28-48 cm) were defined through cluster analysis of the mean abundance of prey items. A permutational MANOVA detected significant differences in the diet and stomach fullness index for TLG, season, and maturation stage. Smaller fishes had a generalized diet, feeding mainly on mysidacea changing their diet above 20 cm TL, where a major consumption of natantia was found. The larger individuals, >28 cm TL, present a less generalized diet with pisces as dominant prey group. Seasonally, natantia and pisces were the principal prey groups during spring and winter, respectively, while mysidacea and other crustaceans were predominant during the rest of the year. Mysidacea were also the main prey group for immature individuals while natantia and pisces were the principal prey groups to the other maturity stages. The results of this study indicate that H. d. dactylopterus has a diverse diet focused on small crustaceans such as misyds and as specimens grow shrimps and fishes become more consumed, with larger specimens having a more specialized diet. The different nutritional needs during spawning season also seemed to influence the feeding habits of H. d. dactylopterus.

  16. Transient, oxidant-induced antioxidant transcript and enzyme levels correlate with greater oxidant-resistance in paraquat-resistant Conyza bonariensis.

    PubMed

    Ye, B; Gressel, J

    2000-06-01

    The elucidation of mechanisms plants use to overcome oxidative stress is facilitated where there is intra-specific genetic variability. The differential induction of higher levels of mRNAs, cytosol and chloroplast antioxidant enzyme activities, and proteins occurred after sub-lethal paraquat treatment of the oxidant-resistant biotype of Conyza bonariensis (L.) Cronq. By 6 h after sub-lethal paraquat treatment the activities of superoxide dismutase (EC 1.15.1.1), ascorbate peroxidase (EC 1.11.1.11), dehydroascorbate reductase (EC 1.8.5), monodehydroascorbate reductase (EC 1.6.5.4), and glutathione peroxidase (EC 1.11.19) had increased, peaking at 24 h and then slowly reverting back to the basal level. Similarly, the levels of mRNAs encoding these enzymes were enhanced by 12 h and peaked at 18-24 h after sub-lethal paraquat treatment. The time courses of the transient elevation of both transcript and antioxidant enzyme levels correlated with a further transient 2.5- to 3.0-fold increase of paraquat resistance, which occurred only in the constitutively resistant biotype. The individual enzymes seem to be part of a coordinately controlled oxidant tolerance in the resistant biotype, utilizing oxidant-induced, increasingly abundant transcript levels, upon which more antioxidant enzymes were synthesized. PMID:10923703

  17. Increased tolerance to photoinhibitory light in paraquat-resistant Conyza bonariensis measured by photoacoustic spectroscopy and sup 14 CO sub 2 -fixation

    SciTech Connect

    Jansen, M.A.K.; Shaaltiel, Y.; Kazzes, D.; Canaani, O.; Malkin, S.; Gressel, J. )

    1989-11-01

    Tolerance to photoinhibition was compared between a paraquat-resistant and a sensitive biotype of Conyza bonariensis (L.). Cronq. Photoinhibitory damage was measured as a decrease in oxygen evolution or energy storage using photoacoustic spectroscopy, or as a decrease of {sup 14}CO{sub 2}-fixation. Prior to exposure to high fluence rates, both biotypes had similar quantum yields of oxygen evolution and energy storage. After exposure to high intensity light, the resistant biotype continued to evolve oxygen and to store energy with a high quantum yield while both energy storage and oxygen evolution were severely reduced in the sensitive biotype. CO{sub 2}-fixation was less rapidly inhibited in the resistant biotype compared to the sensitive one. The data show that the paraquat resistant biotype with its high constitutive levels of the chloroplast localized enzymes of the oxygen detoxification pathway, is also partially protected from photoinhibition. This supports the theory that an enhanced radical scavenging system can give temporary protection against photooxidative damage from a variety of sources.

  18. Heavy metals and trace elements in muscle of silverside (Odontesthes bonariensis) and water from different environments (Argentina): aquatic pollution and consumption effect approach.

    PubMed

    Avigliano, Esteban; Schenone, Nahuel Francisco; Volpedo, Alejandra Vanina; Goessler, Walter; Fernández Cirelli, Alicia

    2015-02-15

    The concentrations of As, Ag, B, Ba, Bi, Ca, Cd, Co, Cr, Fe, Ga, Hg, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb, Sb, Se, Sn, Sr, Te, Ti, U, V and Zn were determined in water and silverside (Odontesthes bonariensis) muscle samples from four important commercial fishing sites (Argentina) by ICPMS. Trace element concentrations in water with well-documented human health effects were above the recommended maximum levels established by Argentinean and international guidelines for the aquatic biota protection in three sampling sites (e.g. As: 28.4-367 μg L(-1); Cd: 0.17-1.05 μg L(-1); Hg: 0.07-0.63 μg L(-1); Zn: 71.3-90.0 μg L(-1)). High concentrations of As, Hg and Pb (0.03-0.76; 0.03-0.42 and 0.04-0.19 mg kg(-1) wet weight, respectively) were found in silverside muscle. Fishing communities associated with contaminated environments are likely to have higher consumption rates and are thus more likely to be exposed to higher concentrations of the toxic elements (As, Hg and Pb). PMID:25460944

  19. H I observations of two new dwarf galaxies: Pisces A and B with the SKA Pathfinder KAT-7

    NASA Astrophysics Data System (ADS)

    Carignan, C.; Libert, Y.; Lucero, D. M.; Randriamampandry, T. H.; Jarrett, T. H.; Oosterloo, T. A.; Tollerud, E. J.

    2016-03-01

    Context. Pisces A and Pisces B are the only two galaxies found via optical imaging and spectroscopy out of 22 Hi clouds identified in the GALFAHI survey as dwarf galaxy candidates. Aims: We derive the Hi content and kinematics of Pisces A and B. Methods: Our aperture synthesis Hi observations used the seven-dish Karoo Array Telescope (KAT-7), which is a pathfinder instrument for MeerKAT, the South African precursor to the mid-frequency Square Kilometre Array (SKA-MID). Results: The low rotation velocities of ~5 km s-1 and ~10 km s-1 in Pisces A and B, respectively, and their Hi content show that they are really dwarf irregular galaxies (dIrr). Despite that small rotation component, it is more the random motions ~9-11 km s-1 that provide most of the gravitational support, especially in the outer parts. The study of their kinematics, especially the strong gradients of random motions, suggest that those two dwarf galaxies are not yet in equilibrium. Conclusions: These Hi- rich galaxies may be indicative of a large population of dwarfs at the limit of detectability. However, such gas-rich dwarf galaxies will most likely never be within the virial radius of MW-type galaxies and become subhalo candidates. Systems such as Pisces A and B are more likely to be found at a few Mpc s from MW-type galaxies. The final FITS cube is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/587/L3

  20. Target Selection for the Arecibo Pisces-Perseus Supercluster Survey (APPSS)

    NASA Astrophysics Data System (ADS)

    Craig, David W.; O'Donoghue, Aileen A.; Haynes, Martha P.; Rosenberg, Jessica L.; Venkatesan, Aparna; Hallenbeck, Gregory L.; Jones, Michael; Koopmann, Rebecca A.; Undergraduate ALFALFA Team

    2016-01-01

    The Arecibo Pisces-Perseus Supercluster Survey (APPSS) is a new large targeted HI survey now underway using Arecibo's L-band Wide receiver system. A major goal is to constrain models of the Pisces Perseus infall, producing 5-σ detections of infall motions ˜500 km s-1. We are targeting sources that are likely to be at the PPS distance, but that are just below the the HI mass detection threshold of the ALFALFA survey. We expect to identify ˜800 objects of mass ˜108—9 M⊙ which will alllow us to constrain the lower mass end of the HI mass function in this infall environment.We have pursued a multi-pronged approach to target selection for this survey. Sources from ALFALFA, SDSS, and the GALEX GCAT single source catalogs were matched and intercompared via multi-band color photometry, surface brightnesses, and appearance in SDSS images. Final target selection based on visual inspection of SDSS images was found to correlate well with a color-selection technique based on GALEX/NUV - SDSS/r. Along with the details of the source selection we will discuss the facilitation and implementation of this process via a multi-institution collaborative website, and early results from the APSS survey.This work has been supported by NSF grant AST-1211005.

  1. Characterization and expression profile of the ovarian cytochrome P-450 aromatase (cyp19A1) gene during thermolabile sex determination in Pejerrey, Odontesthes bonariensis

    USGS Publications Warehouse

    Karube, M.; Fernandino, J.I.; Strobl-Mazzulla, P.; Strussmann, C.A.; Yoshizaki, G.; Somoza, G.M.; Patino, R.

    2007-01-01

    Cytochrome P450 aromatase (cyp19) is an enzyme that catalyzes the conversion of androgens to estrogens and may play a role in temperature- dependent sex determination (TSD) of reptiles, amphibians, and fishes. In this study, the ovarian P450 aromatase form (cyp19A1) of pejerrey Odontesthes bonariensis, a teleost with marked TSD, was cloned and its expression profile evaluated during gonadal differentiation at feminizing (17??C, 100% females), mixed-sex producing (24 and 25??C, 73.3 and 26.7% females, respectively), and masculinizing (29??C, 0% females) temperatures. The deduced cyp19A1 amino acid sequence shared high identity (>77.8%) with that from other teleosts but had low identity (<61.8%) with brain forms (cyp19A2), including that of pejerrey itself. The tissue distribution analysis of cyp19A1 mRNA in adult fish revealed high expression in the ovary. Semi-quantitative reverse transcription polymerase chain reaction analysis of the bodies of larvae revealed that cyp19A1 expression increased before the appearance of the first histological signs of ovarian differentiation at the feminizing temperature but remained low at the masculinizing temperature. The expression levels at mixed-sex producing temperatures were bimodal rather than intermediate, showing low and high modal values similar to those at the feminizing and masculinizing temperatures, respectively. The population percentages of high and low expression levels at intermediate temperatures were proportional to the percentage of females and males, respectively, and high levels were first observed at about the time of sex differentiation of females. These results suggest that cyp19A1 is involved in the process of ovarian formation and possibly also in the TSD of pejerrey. ?? 2007 Wiley-Liss, Inc.

  2. PISCES Program: Plasma-materials interactions and edge-plasma physics research

    SciTech Connect

    Conn, R.W.; Hirooka, Y.

    1992-07-01

    This program investigates and characterizes the behavior of materials under plasma bombordment, in divertor regions. The PISCES facility is used to study divertor and plasma edge management concepts (in particular gas target divertors), as well as edge plasma turbulence and transport. The plasma source consists of a hot LaB[sub 6] cathode with an annular, water-cooled anode and attached drift tube. This cross sectional area of the plasma can be adjusted between 3 and 10 cm. A fast scanning diagnostic probe system was used for mapping plasma density profiles during biased limiter and divertor simulation experiments. Some experimental data are given on: (1) materials and surface physics, (2) edge plasma physics, and (3) a theoretical analysis of edge plasma modelling.

  3. The Arecibo Pisces-Perseus Survey: An Undergraduate ALFALFA Team Project

    NASA Astrophysics Data System (ADS)

    O'Donoghue, Aileen A.; Koopmann, Rebecca A.; Haynes, Martha P.; Jones, Michael; Craig, David; Hallenbeck, Gregory L.; Rosenberg, Jessica L.; Venkatesan, Aparna; Undergraduate ALFALFA Team

    2016-01-01

    The Milky Way's position in an outer filament of Lanieakea affords us a striking view of the Pisces-Perseus Supercluster (PPS) arcing roughly from 22h to 4h and 0° to +50° concentrated between cz = 4,000 km/s and cz = 8,000 km/s as a "wall" parallel to the plane of the sky. It is bounded by voids both between Laniakea and PPS and beyond PPS. Within this box, the 70% ALFALFA survey has detected 4,800 galaxies within cz = 8,000 km/s. Of these, 80% have masses greater than 108 M⊙. At the distance of the PPS, galaxies with MHI ≤ 108 M⊙ are below the ALFALFA detection limit. Thus to further explore this rich diversity of galaxy environments and the adjoining voids, the Undergraduate ALFALFA Team is in the process of using the L-band Wide receiver at Arecibo Observatory for the Arecibo Pisces-Perseus Supercluster Survey (APPSS). We will observe galaxies with 108 M⊙ ≤ MHI ≤ 109 M⊙ chosen from the SDSS DR12 and GALEX catalogs. We are limiting our observations to the PPS ridge in 21h 30m to 3h 15m and 23° to 35°. Since this region lacks SDSS spectroscopy, targets have been selected using photometric criteria derived from SDSS and GALEX observations for galaxies detected by ALFALFA. The results of these observations will allow us to constrain the HI mass function along the PPS ridge. Application of the Tully-Fisher relation will allow a robust measure of the infall velocities of galaxies into the filament. This work has been supported by NSF grant AST-1211005.

  4. An Extended View of the Pisces Overdensity from the SCUSS Survey

    NASA Astrophysics Data System (ADS)

    Nie, J. D.; Smith, M. C.; Belokurov, V.; Fan, X. H.; Fan, Z.; Irwin, M. J.; Jiang, Z. J.; Jing, Y. P.; Koposov, S. E.; Lesser, M.; Ma, J.; Shen, S. Y.; Wang, J. L.; Wu, Z. Y.; Zhang, T. M.; Zhou, X.; Zhou, Z. M.; Zou, H.

    2015-09-01

    The South Galactic Cap u-band Sky Survey (SCUSS) is a u-band photometric survey covering about 4000 square degrees of the South Galactic Cap, reaching depths of up to 23 mag. By extending around 1.5 mag deeper than the Sloan Digital Sky Survey (SDSS) single-epoch u data, SCUSS is able to probe a much larger volume of the outer halo, i.e., with SCUSS data blue horizontal branch (BHB) stars can trace the outer halo of the Milky Way as far as 100-150 kpc. Utilizing this advantage we combine the SCUSS u-band with the SDSS DR9 gri photometric bands to identify BHB stars and explore halo substructures. We confirm the existence of the Pisces overdensity, which is a structure in the outer halo (at around 80 kpc) that was discovered using RR Lyrae stars. For the first time we are able to determine its spatial extent, finding that it appears to be part of a stream with a clear distance gradient. The stream, which is ˜5° wide and stretches along ˜25°, consists of 20-30 BHBs with a total significance of around 6σ over the background. Assuming we have detected the entire stream and that the progenitor has fully disrupted, then the number of BHBs suggests that the original system was similar to a smaller classical or a larger ultra-faint dwarf galaxy. On the other hand, if the progenitor still exists, it can be hunted for by reconstructing its orbit from the distance gradient of the stream. This new picture of the Pisces overdensity sheds new light on the origin of this intriguing system.

  5. Silversides of the genus Labidesthes (Atheriniformes: Atherinopsidae).

    PubMed

    Werneke, David C; Armbruster, Jonathan W

    2015-01-01

    The two species of Labidesthes, L. sicculus and L. vanhyningi, are herein redescribed. Labidesthes sicculus is separated from L. vanhyningi by the presence of an anterolateral process of the post temporal that is longer than it is wide (versus wider than long), a ratio of thoracic length to abdominal length greater than two (versus less than two), and a midlateral stripe that is narrows in front of first dorsal fin (versus expanding in front of first dorsal fin). Labidesthes sicculus is found in Gulf of Mexico drainages from the Brazos River East to the Pascagoula River, Mississippi River (absent in middle and upper Missouri River), and Great Lakes-St. Lawrence River (absent in Lake Superior). Labidesthes vanhyningi is found in Gulf Mexico drainages from the Neches River East around peninsular Florida North on the Atlantic Coast to the Pee Dee River, in the Mississippi River it is confined to lowland areas of the Lower Mississippi River. PMID:26624384

  6. The Absolute Age of the Globular Cluster M15 Using Near-infrared Adaptive Optics Images from PISCES/LBT.

    NASA Astrophysics Data System (ADS)

    Monelli, M.; Testa, V.; Bono, G.; Ferraro, I.; Iannicola, G.; Fiorentino, G.; Arcidiacono, C.; Massari, D.; Boutsia, K.; Briguglio, R.; Busoni, L.; Carini, R.; Close, L.; Cresci, G.; Esposito, S.; Fini, L.; Fumana, M.; Guerra, J. C.; Hill, J.; Kulesa, C.; Mannucci, F.; McCarthy, D.; Pinna, E.; Puglisi, A.; Quiros-Pacheco, F.; Ragazzoni, R.; Riccardi, A.; Skemer, A.; Xompero, M.

    2015-10-01

    We present deep near-infrared J, {K}{{s}} photometry of the old, metal-poor Galactic globular cluster M15 obtained with images collected with the LUCI1 and PISCES cameras available at the Large Binocular Telescope (LBT). We show how the use of First Light Adaptive Optics (FLAO) system coupled with the PISCES camera allows us to improve the limiting magnitude by ˜2 mag in {K}{{s}}. By analyzing archival Hubble Space Telescope data, we demonstrate that the quality of the LBT/PISCES color-magnitude diagram is fully comparable with analogous space-based data. The smaller field of view is balanced by the shorter exposure time required to reach a similar photometric limit. We investigated the absolute age of M15 by means of two methods: (i) by determining the age from the position of the main-sequence turnoff (MSTO), and (ii) by the magnitude difference between the MSTO and the well-defined knee detected along the faint portion of the MS. We derive consistent values of the absolute age of M15, that is, 12.9 ± 2.6 Gyr and 13.3 ± 1.1 Gyr, respectively. Observations were carried out using the Large Binocular Telescope at Mount Graham, AZ. The LBT is 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.

  7. HST Imaging of the Local Volume Dwarf Galaxies Pisces A and B: Prototypes for Local Group Dwarfs

    NASA Astrophysics Data System (ADS)

    Tollerud, Erik J.; Geha, Marla C.; Grcevich, Jana; Putman, Mary E.; Weisz, Daniel R.; Dolphin, Andrew E.

    2016-08-01

    We present observations of the Pisces A and B galaxies with the Advanced Camera for Surveys on the Hubble Space Telescope. Photometry from these images clearly resolves a red giant branch (RGB) for both objects, demonstrating that they are nearby dwarf galaxies. We describe a Bayesian inferential approach to determining the distance to these galaxies using the magnitude of the tip of the RGB, and then apply this approach to these galaxies. This reveals the distance to these galaxies as {5.64}-0.15+0.13 {{Mpc}} and {8.89}-0.85+0.75 {{Mpc}} for Pisces A and B, respectively, placing both within the Local Volume but not the Local Group (LG). We estimate the star formation histories of these galaxies, which suggests that they have recently undergone an increase in their star formation rates. Together these yield luminosities for Pisces A and B of {M}V=-{11.57}-0.05+0.06 and ‑12.9 ± 0.2, respectively, and estimated stellar masses of {log}({M}* /{M}ȯ )={7.0}-1.7+0.4 and {7.5}-1.8+0.3. We further show that these galaxies are likely at the boundary between nearby voids and higher-density filamentary structure. This suggests that they are entering a higher-density region from voids, where they would have experienced delayed evolution, consistent with their recent increased star formation rates. If this is indeed the case, they are useful for study as proxies of the galaxies that later evolved into typical LG satellite galaxies.

  8. Materials erosion and redeposition studies at the PISCES-facility: net erosion under redeposition

    SciTech Connect

    Hirooka, Y.; Goebel, D.M.; Conn, R.W.; Leung, W.K.; Campbell, G.A.

    1986-05-01

    Simultaneous erosion and redeposition of copper and 304 stainless steel under controlled and continuous plasma (D,He,Ar) bombardment has been investigated in the PISCES-facility, which generates typical edge-plasma conditions of magnetic fusion devices. The plasma bombardment conditions are: incident ion flux in the range from 10/sup 17/ to 10/sup 18/ ions/sec/cm/sup 2/, ion bombarding energy of 100 eV, electron temperature in the range from 5 to 15 eV, plasma density in the range from 10/sup 11/ to 10/sup 13/ cm/sup -3/, target temperature in the range from 300 to 900K, and the total ion fluence in the range from 10/sup 20/ to 10/sup 22/ ions/cm/sup 2/. The net erosion yield under redeposition is found to be significantly smaller than the classical sputtering yield data. A first-order modeling is attempted to interpret the erosion and redeposition behavior of materials under plasma bombardment. It is pointed out both theoretically and experimentally that the mean free path for electron impact ionization of the sputtered material is the key parameter to control the overall mechanism of erosion and redeposition. Strongly modified surface morphologies of bombarded targets are observed and indicate a retrapping effect.

  9. Mixed Material Plasma-Surface Interactions in ITER: Recent Results from the PISCES Group

    SciTech Connect

    Tynan, George R.; Baldwin, Matthew; Doerner, Russell; Hollmann, Eric; Nishijima, Daisuke; Umstadter, Karl; Yu, Jonathan

    2010-05-20

    This paper summarizes recent PISCES studies focused on the effects associated with mixed species plasmas that are similar in composition to what one might expect in ITER. Formation of nanometer scale whiskerlike features occurs in W surfaces exposed to pure He and mixed D/He plasmas and appears to be associated with the formation of He nanometer-scaled bubbles in the W surface. Studies of Be-W alloy formation in Be-seeded D plasmas suggest that this process may be important in ITER all metal wall operational scenarios. Studies also suggest that BeD formation via chemical sputtering of Be walls may be an important first wall erosion mechanism. D retention in ITER mixed materials has also been studied. The D release behavior from beryllium co-deposits does not appear to be a diffusion dominated process, but instead is consistent with thermal release from a number of variable trapping energy sites. As a result, the amount of tritium remaining in codeposits in ITER after baking will be determined by the maximum temperature achieved, rather than by the duration of the baking cycle.

  10. [Reproduction of the fish Gymnothorax equatorialis (Pisces: Muraenidae) in Jalisco and Colima, Mexico].

    PubMed

    Lucano-Ramírez, G; Ruiz-Ramírez, S; Rojo-Vázquez, J A; González-Sansón, G

    2008-03-01

    Reproduction of the fish Gymnothorax equatorialis (Pisces: Muraenidae) in Jalisco and Colima, Mexico. A total of 707 Gymnothorax equatorialis were collected monthly in the Jalisco and Colima coast, Mexico, from December 1995 to December 1998 and from August to November 1999, in order to determine their reproduction patterns. Females outnumbered and had longer bodies (mean length 54.7 cm) than males (52.1 cm). The minimum, maximum and mean values of total fecundity were respectively 9 660, 99 992 and 32 029 eggs. The total body length at which 50 percent of individuals have ripe gonads (L50) was 43.7 cm for females and 42.7 cm TL for males. Ovaries had two main types of oocytes: small inmature in cromatin nucleolus phase (85.1 microm) and large mature in secundary vitellogenesis phase (701.6 microm). High numbers of spermatozoa were observed in the seminal tubes of ripe testicles, which presented a lobular development. Based in gonad features and temporal changes in the gonad-somatic index, it is concluded that G. equatorialis has two relatively short reproduction periods (at the middle and at the end of the year). PMID:18624233

  11. [Size composition and reproductive cycle of Pseudupeneus grandisquamis (Pisces: Mullidae) in the Central Mexican Pacific].

    PubMed

    Lucano-Ramírez, G; Ruiz-Ramírez, S; Rojo-Vázquez, J A

    2006-03-01

    Size composition and reproductive cycle of Pseudupeneus grandisquamis (Pisces: Mullidae) in the Central Mexican Pacific. From June 1995 to December 1998 we used shrimp trawl nets to capture 492 Pseudupeneus grandisquamis in soft-bottom grounds off the central Mexican Pacific (Jalisco and Colima). The ength-weight ratio indicates allometric growth (p = 0.0035L(3.46) y r2 = 0.97). The total sex ratio was 1:1.15 (females: males). Mean total length was 153.8 mm (range 77-236 mm). A progression in length was found: the highest means were observed at the end of 1996 and during 1997. The mean length of females (162 mm) was longer than in males (150 mm). Four gonadic maturity stages were observed in both sexes; in females the most frequently stage was stage IV (mature gonads, 48.6%), while in males it was stage III (gonads in maturation, 45.0%). Seven microscopic oocyte development stages were identified. Oocyte development seems to be asynchronous. The mature testicle showed sperm inside the lobular lumen and in the duct. The highest values of the gonadosomatic index, as well as the largest percentages of individuals with mature gonads (at macroscopic and microscopic levels), were observed during winter and summer, suggesting that this species has two reproduction peaks by year. The length at which 50% of the individuals show gonads in maturation (L50) was 183 mm for the females and 181 mm for the males. PMID:18457188

  12. TWO LOCAL VOLUME DWARF GALAXIES DISCOVERED IN 21 cm EMISSION: PISCES A AND B

    SciTech Connect

    Tollerud, Erik J.; Geha, Marla C.; Grcevich, Jana; Putman, Mary E.; Stern, Daniel E-mail: marla.geha@yale.edu E-mail: mputman@astro.columbia.edu

    2015-01-01

    We report the discovery of two dwarf galaxies, Pisces A and B, from a blind 21 cm H I search. These were the only two galaxies found via optical imaging and spectroscopy of 22 H I clouds identified in the GALFA-H I survey as dwarf galaxy candidates. They have properties consistent with being in the Local Volume (<10 Mpc), and one has resolved stellar populations such that it may be on the outer edge of the Local Group (∼1 Mpc from M31). While the distance uncertainty makes interpretation ambiguous, these may be among the faintest star-forming galaxies known. Additionally, rough estimates comparing these galaxies to ΛCDM dark matter simulations suggest consistency in number density, implying that the dark matter halos likely to host these galaxies are primarily H I-rich. The galaxies may thus be indicative of a large population of dwarfs at the limit of detectability that are comparable to the faint satellites of the Local Group. Because they are outside the influence of a large dark matter halo to alter their evolution, these galaxies can provide critical anchors to dwarf galaxy formation models.

  13. An RR Lyrae family portrait: 33 stars observed in Pisces with K2-E2

    NASA Astrophysics Data System (ADS)

    Molnár, L.; Szabó, R.; Moskalik, P. A.; Nemec, J. M.; Guggenberger, E.; Smolec, R.; Poleski, R.; Plachy, E.; Kolenberg, K.; Kolláth, Z.

    2015-10-01

    A detailed analysis is presented of 33 RR Lyrae stars in Pisces observed with the Kepler space telescope over the 8.9-d long K2 Two-Wheel Concept Engineering Test. The sample includes not only fundamental-mode and first-overtone (RRab and RRc) stars but the first two double-mode (RRd) stars that Kepler detected and the only modulated first-overtone star ever observed from space so far. The precision of the extracted K2 light curves made it possible to detect low-amplitude additional modes in all subtypes. All RRd and non-modulated RRc stars show the additional mode at PX/P1 ˜ 0.61 that was detected in previous space-based photometric measurements. A periodicity longer than the fundamental mode was tentatively identified in one RRab star that might belong to a gravity mode. We determined the photometric [Fe/H] values for all fundamental-mode stars and provide the preliminary results of our efforts to fit the double-mode stars with non-linear hydrodynamic pulsation models. The results from this short test run indicate that the K2 mission will be, and has started to be, an ideal tool to expand our knowledge about RR Lyrae stars. As a by-product of the target search and analysis, we identified 165 bona fide double-mode RR Lyrae stars from the Catalina Sky Survey observations throughout the sky, 130 of which are new discoveries.

  14. Catoessa boscii (Crustacea, Isopoda, Cymothoidae) parasitic on Carangoides malabaricus (Pisces, Carangidae) from India. Taxonomy and host-parasite relationships.

    PubMed

    Trilles, Jean-Paul; Ravichandran, Samuthirapandian; Rameshkumar, Ganapathy

    2012-06-01

    Catoessa boscii (Bleeker, 1857) (Crustacea, Isopoda, Cymothoidae), is redescribed according to the type specimen observed by Schioedte and Meinert (1884) extant in the Rijksmuseum von Natuurlijke Historie, Leiden (RMNH) and from many additional specimens recently collected in India from Carangoides malabaricus (Pisces, Carangidae). This study allows an updating of the diagnosis of the genus Catoessa and of the species Catoessa boscii. Some parasite-host relationships were studied during the year. Prevalence and sex ratio of parasites varied according to the month, and the sex and size of hosts. PMID:22807055

  15. Structural studies of haemoglobin from pisces species shortfin mako shark (Isurus oxyrinchus) at 1.9 Å resolution.

    PubMed

    Ramesh, Pandian; Sundaresan, S S; Sathya Moorthy, Pon; Balasubramanian, M; Ponnuswamy, M N

    2013-11-01

    Haemoglobin (Hb) is a tetrameric iron-containing protein that carries oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. Pisces are the advanced aquatic vertebrates capable of surviving at wide depth ranges. The shortfin mako shark (SMS) is the pelagic, largest, fastest and most sophisticated species of the shark kingdom with well developed eyes. Mostly the pisces species are cold blooded in nature. Distinctly, the SMSs are warm-blooded animals with an advanced circulatory system. SMSs are capable of maintaining elevated muscle temperatures up to 33 K above the ambient water temperatures at a depth of 150-500 m. SMSs have a diverged air-breathing mechanism compared with other vertebrates. The haemoglobin molecule consists of four polypeptide chains, namely two α chains, each with 140 amino acids and two β chains each having 136 amino acids. The SMS Hb was found to crystallize in monoclinic space group P21 using the hanging-drop vapour-diffusion method at room temperature. The crystal packing parameters for the SMS Hb structure contain one whole biological molecule in the asymmetric unit with a solvent content of 47%. The SMS Hb quaternary structural features interface-interface interactions and heme binding sites are discussed with different state Hbs and the results reveal that SMS Hb adopts an unliganded deoxy T state conformation. PMID:24121325

  16. Discovery of an Ultra-diffuse Galaxy in the Pisces--Perseus Supercluster

    NASA Astrophysics Data System (ADS)

    Martínez-Delgado, David; Läsker, Ronald; Sharina, Margarita; Toloba, Elisa; Fliri, Jürgen; Beaton, Rachael; Valls-Gabaud, David; Karachentsev, Igor D.; Chonis, Taylor S.; Grebel, Eva K.; Forbes, Duncan A.; Romanowsky, Aaron J.; Gallego-Laborda, J.; Teuwen, Karel; Gómez-Flechoso, M. A.; Wang, Jie; Guhathakurta, Puragra; Kaisin, Serafim; Ho, Nhung

    2016-04-01

    We report the discovery of DGSAT I, an ultra-diffuse, quenched galaxy located 10.°4 in projection from the Andromeda galaxy (M31). This low-surface brightness galaxy (μV = 24.8 mag arcsec-2), found with a small amateur telescope, appears unresolved in sub-arcsecond archival Subaru/Suprime-Cam images, and hence has been missed by optical surveys relying on resolved star counts, in spite of its relatively large effective radius (Re(V) = 12″) and proximity (15‧) to the well-known dwarf spheroidal galaxy And II. Its red color (V - I = 1.0), shallow Sérsic index (nV = 0.68), and the absence of detectable Hα emission are typical properties of dwarf spheroidal galaxies and suggest that it is mainly composed of old stars. Initially interpreted as an interesting case of an isolated dwarf spheroidal galaxy in the local universe, our radial velocity measurement obtained with the BTA 6 m telescope (Vh = 5450 ± 40 km s-1) shows that this system is an M31-background galaxy associated with the filament of the Pisces-Perseus supercluster. At the distance of this cluster (˜78 Mpc), DGSAT I would have an Re ˜ 4.7 kpc and MV ˜ -16.3. Its properties resemble those of the ultra-diffuse galaxies (UDGs) recently discovered in the Coma cluster. DGSAT I is the first case of these rare UDGs found in this galaxy cluster. Unlike the UDGs associated with the Coma and Virgo clusters, DGSAT I is found in a much lower density environment, which provides a fresh constraint on the formation mechanisms for this intriguing class of galaxy.

  17. Hydrothermal Systems on Kermadec Arc Volcanoes Revealed by PISCES V Submersible Dives

    NASA Astrophysics Data System (ADS)

    Embley, R. W.; de Ronde, C. E.; Massoth, G. J.; Wright, I. C.; Butterfield, D. A.; Clark, M. R.; Chadwick, W. W.; Lupton, J. E.; Malahoff, A.; Rowden, A. A.; Stott, M.; Evans, L. J.; Greene, R. R.; Opatkiewicz, A.; Roe, K.

    2005-12-01

    An interdisciplinary team of scientists from New Zealand and the United States conducted seventeen dives with the PISCES V at eight Kermadec arc volcanoes (seven were the first exploration) in April and May of 2005. The dive sites were selected based on the results of water column and multibeam surveys conducted by the New Zealand research vessel Tangaroa between 1999 and 2004. Five of the sites (Monowai, Macauley, "W", Brothers and Healy) were in calderas or on young cones within calderas. Two sites were on the summits of stratovolcanoes (Rumble V and Clark) without calderas and one site was in a summit crater (Giggenbach). A planned dive site on Monowai Cone was cancelled due to safety concerns based on its history of recent volcanic activity from hydroacoustic monitoring, mass-wasting and surface observations of sulfur slicks and CO2 bubble columns made in the October 2004. Hydrothermal systems were found at all of the sites but they differed in the style of venting. Three factors appear to determine the character of venting on the Kermadec Arc volcanoes. First, depth exerts important boundary conditions on the style of venting because of its control of the boiling point of seawater. The sites range in depth from less than 100 m (Giggenbach) to 1800 m (Brothers caldera wall). At the shallowest depths, degassing and boiling were observed (Giggenbach Volcano at 180 m) commonly accompanied by the precipitation of elemental sulfur (340 m at the bottom of the summit crater at Macauley Cone). At greater depths such as the northwest wall of Brother's volcano, higher temperature vent fluids alter near-surface country rock and have precipitated massive sulfides on the seafloor. Second, some of the volcanoes (Monowai, Brothers and Macauley cones and Giggenbach crater) have likely had recent magmatic/eruptive activity which could result in the enhanced degassing. Finally, outcrop-scale fracturing that mimics larger-scale regional tectonic lineaments appears to focus the

  18. VizieR Online Data Catalog: 33 RR Lyrae observed in Pisces with K2-E2 (Molnar+, 2015)

    NASA Astrophysics Data System (ADS)

    Molnar, L.; Szabo, R.; Moskalik, P. A.; Nemec, J. M.; Guggenberger, E.; Smolec, R.; Poleski, R.; Plachy, E.; Kolenberg, K.; Kollath, Z.

    2016-03-01

    Kepler observed a stellar field around the vernal equinox point in Pisces (centre coordinates: RA=359°, DE=-2°) between 2014 February 04 and 13. The primary goal of this K2 Two-Wheel Concept Engineering Test (hereafter K2-E2) was to test the performance of the telescope in fine guidance mode. As well, the observations of nearly 2000 targets were made available for the scientific community. We identified 33 potential RR Lyrae stars in the K2-E2 sample and extracted their photometric data with the pyke software, developed for the Kepler mission by the Kepler Guest Observer Office (Still & Barclay, 2012, Astrophysics Source Code Library record ascl:1208.004). (6 data files).

  19. The PISC parametric study on the effect of cast austenitic steel macrostructure on the capability of ultrasonic examination

    SciTech Connect

    Maes, G.; Hansoul, B.; Dombret, P.

    1994-12-31

    Within the framework of Action 4 (Austenitic Steel Testing) of PISC 3, a parametric study was carried out on a set of centrifugically cast stainless steel samples, representative of the main coolant piping of pressurized water nuclear reactors. The samples are obtained from different manufacturers, and feature various grain structures and dimensions. Artificial and realistic flaws were used to assess the detection and sizing capability of ultrasonic examination techniques. The paper analyzes the data as a function of the metal structure and of the main parameters of the testing techniques, which include TRL contact probes and immersion focusing transducers. Guidelines are deduced as to the selection of inspection techniques, in relation with the metallurgical structure of each specimen. In addition, the influence of the presence of a weld across the wavepath is evaluated, as well as the similarity, between the responses obtained from crack-like machined reflectors and mechanical fatigue cracks.

  20. PISCES Program: Plasma-materials interactions and edge-plasma physics research. Progress report, 1991--1992

    SciTech Connect

    Conn, R.W.; Hirooka, Y.

    1992-07-01

    This program investigates and characterizes the behavior of materials under plasma bombordment, in divertor regions. The PISCES facility is used to study divertor and plasma edge management concepts (in particular gas target divertors), as well as edge plasma turbulence and transport. The plasma source consists of a hot LaB{sub 6} cathode with an annular, water-cooled anode and attached drift tube. This cross sectional area of the plasma can be adjusted between 3 and 10 cm. A fast scanning diagnostic probe system was used for mapping plasma density profiles during biased limiter and divertor simulation experiments. Some experimental data are given on: (1) materials and surface physics, (2) edge plasma physics, and (3) a theoretical analysis of edge plasma modelling.

  1. The WSRT ZoA Perseus-Pisces Filament wide-field HI imaging survey I. HI catalogue and atlas

    NASA Astrophysics Data System (ADS)

    Ramatsoku, M.; Verheijen, M. A. W.; Kraan-Korteweg, R. C.; Józsa, G. I. G.; Schröder, A. C.; Jarrett, T. H.; Elson, E. C.; van Driel, W.; de Blok, W. J. G.; Henning, P. A.

    2016-04-01

    We present results of a blind 21cm H I-line imaging survey of a galaxy overdensity located behind the Milky Way at ℓ, b ≈ 160°, 0.5°. The overdensity corresponds to a Zone-of-Avoidance crossing of the Perseus-Pisces Supercluster filament. Although it is known that this filament contains an X-ray galaxy cluster (3C 129) hosting two strong radio galaxies, little is known about galaxies associated with this potentially rich cluster because of the high Galactic dust extinction. We mapped a sky area of ˜9.6 sq.deg using the Westerbork Synthesis Radio Telescope in a hexagonal mosaic of 35 pointings observed for 12 hours each, in the radial velocity range cz = 2400 - 16600 km s-1. The survey has a sensitivity of 0.36 mJy/beam rms at a velocity resolution of 16.5 km s-1. We detected 211 galaxies, 62% of which have a near-infrared counterpart in the UKIDSS Galactic Plane Survey. We present a catalogue of the H I properties and an H I atlas containing total intensity maps, position-velocity diagrams, global H I profiles and UKIDSS counterpart images. For the resolved galaxies we also present H I velocity fields and radial H I surface density profiles. A brief analysis of the structures outlined by these galaxies finds that 87 of them lie at the distance of the Perseus-Pisces Supercluster (cz ˜ 4000 - 8000 km s-1) and seem to form part of the 3C 129 cluster. Further 72 detections trace an overdensity at a velocity of cz ≈ 10000 km s-1 and seem to coincide with a structure predicted from mass density reconstructions in the first 2MASS Redshift Survey.

  2. Impurity transport and retention in a gas target divertor: simulation experiments in PISCES-A and modeling results

    NASA Astrophysics Data System (ADS)

    Schmitz, L.; Blush, L.; Chevalier, G.; Lehmer, R.; Hirooka, Y.; Chia, P.; Tynan, G.; Conn, R. W.

    1992-12-01

    Impurity retention in the gaseous divertor regime is investigated in the PISCES-A facility at UCLA. We report measurements and 1 1/2D fluid modeling results of impurity transport for typical tokamak divertor plasma parameters (10 18≤ ne≤3×10 19m -3, kTe≤20 eV). The neutral hydrogen density close to the (simulated) divertor target is 10 20≤ n0≤3×10 21 m -3. Gaseous trace impurities (argon, neon) as well as low- Z and high- Z materials sputtering carbon, tungsten) are studied. It is observed that the impurity retention in a gaseous divertor is substantially improved as compared to conventional divertor operating regimes. The modeling results suggest that the retention of neutral and ionized impurities is mainly due to collisions with hydrogen (deuterium) neutrals and ions streaming towards the divertor target a a velocity of 0.25-0.5 cs. A low level of residual impurity transport, observed at high neutral density, is attributed to a plasma flow reversal close to the radial boundary. Sputtering of a tungsten sample by intrinsic impurities has been shown to decrease substantially for target electron temperatures kTe<5 eV.

  3. Structural studies of haemoglobin from pisces species shortfin mako shark (Isurus oxyrinchus) at 1.9 Å resolution

    PubMed Central

    Ramesh, Pandian; Sundaresan, S. S.; Sathya Moorthy, Pon.; Balasubramanian, M.; Ponnuswamy, M. N.

    2013-01-01

    Haemoglobin (Hb) is a tetrameric iron-containing protein that carries oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. Pisces are the advanced aquatic vertebrates capable of surviving at wide depth ranges. The shortfin mako shark (SMS) is the pelagic, largest, fastest and most sophisticated species of the shark kingdom with well developed eyes. Mostly the pisces species are cold blooded in nature. Distinctly, the SMSs are warm-blooded animals with an advanced circulatory system. SMSs are capable of maintaining elevated muscle temperatures up to 33 K above the ambient water temperatures at a depth of 150–500 m. SMSs have a diverged air-breathing mechanism compared with other vertebrates. The haemoglobin molecule consists of four polypeptide chains, namely two α chains, each with 140 amino acids and two β chains each having 136 amino acids. The SMS Hb was found to crystallize in monoclinic space group P21 using the hanging-drop vapour-diffusion method at room temperature. The crystal packing parameters for the SMS Hb structure contain one whole biological molecule in the asymmetric unit with a solvent content of 47%. The SMS Hb quaternary structural features interface–interface interactions and heme binding sites are discussed with different state Hbs and the results reveal that SMS Hb adopts an unliganded deoxy T state conformation. PMID:24121325

  4. Atmospheric deposition impacts on nutrients and biological budgets of the Mediterranean Sea, results from the high resolution coupled model NEMOMED12/PISCES

    NASA Astrophysics Data System (ADS)

    Richon, Camille; Dutay, Jean-Claude; Dulac, François; Desboeufs, Karine; Nabat, Pierre; Guieu, Cécile; Aumont, Olivier; Palmieri, Julien

    2016-04-01

    Atmospheric deposition is at present not included in regional oceanic biogeochemical models of the Mediterranean Sea, whereas, along with river inputs, it represents a significant source of nutrients at the basin scale, especially through intense desert dust events. Moreover, observations (e.g. DUNE campaign, Guieu et al. 2010) show that these events significantly modify the biogeochemistry of the oligotrophic Mediterranean Sea. We use a high resolution (1/12°) version of the 3D coupled model NEMOMED12/PISCES to investigate the effects of high resolution atmospheric dust deposition forcings on the biogeochemistry of the Mediterranean basin. The biogeochemical model PISCES represents the evolution of 24 prognostic tracers including five nutrients (nitrate, ammonium, phosphate, silicate and iron) and two phytoplankton and zooplanktons groups (Palmiéri, 2014). From decadal simulations (1982-2012) we evaluate the influence of natural dust and anthropogenic nitrogen deposition on the budget of nutrients in the basin and its impact on the biogeochemistry (primary production, plankton distributions...). Our results show that natural dust deposition accounts for 15% of global PO4 budget and that it influences primarily the southern part of the basin. Anthropogenic nitrogen accounts for 50% of bioavailable N supply for the northern part. Deposition events significantly affect biological production; primary productivity enhancement can be as high as 30% in the areas of high deposition, especially during the stratified period. Further developments of the model will include 0D and 1D modeling of bacteria in the frame of the PEACETIME project.

  5. Tidal Signatures in the Faintest Milky Way Satellites: The Detailed Properties of Leo V, Pisces II, and Canes Venatici II

    NASA Astrophysics Data System (ADS)

    Sand, David J.; Strader, Jay; Willman, Beth; Zaritsky, Dennis; McLeod, Brian; Caldwell, Nelson; Seth, Anil; Olszewski, Edward

    2012-09-01

    We present deep wide-field photometry of three recently discovered faint Milky Way (MW) satellites: Leo V, Pisces II, and Canes Venatici II. Our main goals are to study the structure and star formation history of these dwarfs; we also search for signs of tidal disturbance. The three satellites have similar half-light radii (~60-90 pc) but a wide range of ellipticities. Both Leo V and CVn II show hints of stream-like overdensities at large radii. An analysis of the satellite color-magnitude diagrams shows that all three objects are old (>10 Gyr) and metal-poor ([Fe/H] ~ -2), though neither the models nor the data have sufficient precision to assess when the satellites formed with respect to cosmic reionization. The lack of an observed younger stellar population (lsim 10 Gyr) possibly sets them apart from the other satellites at Galactocentric distances >~ 150 kpc. We present a new compilation of structural data for all MW satellite galaxies and use it to compare the properties of classical dwarfs to the ultra-faints. The ellipticity distribution of the two groups is consistent at the ~2σ level. However, the faintest satellites tend to be more aligned toward the Galactic Center, and those satellites with the highest ellipticity (gsim 0.4) have orientations (ΔθGC) in the range 20° <~ ΔθGC <~ 40°. This latter observation is in rough agreement with predictions from simulations of dwarf galaxies that have lost a significant fraction of their dark matter halos and are being tidally stripped. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile and the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

  6. TIDAL SIGNATURES IN THE FAINTEST MILKY WAY SATELLITES: THE DETAILED PROPERTIES OF LEO V, PISCES II, AND CANES VENATICI II

    SciTech Connect

    Sand, David J.; Strader, Jay; McLeod, Brian; Caldwell, Nelson; Willman, Beth; Zaritsky, Dennis; Olszewski, Edward; Seth, Anil

    2012-09-01

    We present deep wide-field photometry of three recently discovered faint Milky Way (MW) satellites: Leo V, Pisces II, and Canes Venatici II. Our main goals are to study the structure and star formation history of these dwarfs; we also search for signs of tidal disturbance. The three satellites have similar half-light radii ({approx}60-90 pc) but a wide range of ellipticities. Both Leo V and CVn II show hints of stream-like overdensities at large radii. An analysis of the satellite color-magnitude diagrams shows that all three objects are old (>10 Gyr) and metal-poor ([Fe/H] {approx} -2), though neither the models nor the data have sufficient precision to assess when the satellites formed with respect to cosmic reionization. The lack of an observed younger stellar population ({approx}< 10 Gyr) possibly sets them apart from the other satellites at Galactocentric distances {approx}> 150 kpc. We present a new compilation of structural data for all MW satellite galaxies and use it to compare the properties of classical dwarfs to the ultra-faints. The ellipticity distribution of the two groups is consistent at the {approx}2{sigma} level. However, the faintest satellites tend to be more aligned toward the Galactic Center, and those satellites with the highest ellipticity ({approx}> 0.4) have orientations ({Delta}{theta}{sub GC}) in the range 20 Degree-Sign {approx}< {Delta}{theta}{sub GC} {approx}< 40 Degree-Sign . This latter observation is in rough agreement with predictions from simulations of dwarf galaxies that have lost a significant fraction of their dark matter halos and are being tidally stripped.

  7. The WSRT ZoA Perseus-Pisces filament wide-field H I imaging survey - I. H I catalogue and atlas

    NASA Astrophysics Data System (ADS)

    Ramatsoku, M.; Verheijen, M. A. W.; Kraan-Korteweg, R. C.; Józsa, G. I. G.; Schröder, A. C.; Jarrett, T. H.; Elson, E. C.; van Driel, W.; de Blok, W. J. G.; Henning, P. A.

    2016-07-01

    We present results of a blind 21cm H I-line imaging survey of a galaxy overdensity located behind the Milky Way at ℓ, b ≈ 160°, 0.5°. The overdensity corresponds to a zone-of-avoidance crossing of the Perseus-Pisces Supercluster filament. Although it is known that this filament contains an X-ray galaxy cluster (3C 129) hosting two strong radio galaxies, little is known about galaxies associated with this potentially rich cluster because of the high Galactic dust extinction. We mapped a sky area of ˜9.6 deg2 using the Westerbork Synthesis Radio Telescope in a hexagonal mosaic of 35 pointings observed for 12 h each, in the radial velocity range cz = 2400-16 600 km s-1. The survey has a sensitivity of 0.36 mJy beam-1 rms at a velocity resolution of 16.5 km s-1. We detected 211 galaxies, 62 per cent of which have a near-infrared counterpart in the UKIDSS Galactic Plane Survey. We present a catalogue of the H I properties and an H I atlas containing total intensity maps, position-velocity diagrams, global H I profiles and UKIDSS counterpart images. For the resolved galaxies we also present H I velocity fields and radial H I surface density profiles. A brief analysis of the structures outlined by these galaxies finds that 87 of them lie at the distance of the Perseus-Pisces Supercluster (cz ˜ 4000-8000 km s-1) and seem to form part of the 3C 129 cluster. Further 72 detections trace an overdensity at a velocity of cz ≈ 10 000 km s-1 and seem to coincide with a structure predicted from mass density reconstructions in the first 2MASS Redshift Survey.

  8. Temperature influence on deuterium retention for Be-W mixed thin films prepared by Thermionic Vacuum Arc method exposed to PISCES B plasma

    NASA Astrophysics Data System (ADS)

    Jepu, I.; Doerner, R. P.; Baldwin, M. J.; Porosnicu, C.; Lungu, C. P.

    2015-08-01

    Beryllium-tungsten thin films with well controlled elemental composition were prepared using Thermionic Vacuum Arc (TVA) technique and subsequently exposed to steady state, high ion flux (5.5 - 9.8 × 1022 ions m-2 s-1) deuterium (D) plasma in the PISCES-B facility to consistent fluences of 2.3 × 1026 m-2. Six types of layers were studied, ranging from pure Be, composite Be-W, having the atomic ratios of 9:1; 7:3; 1:1; 3:7; to pure W with a total deposited layer thickness of 2 μm. The sample exposure temperatures, namely 300 K, 473 K, 573 K and 773 K, respectively, were measured in situ with a thermocouple placed on the back of the sample. Morphological and structural examinations were undertaken before and after plasma exposure. Results show an influence of temperature on the subsequent morphology of the surface. Thermal Desorption Spectrometry (TDS) spectra showed a change in the D release behavior for different Be-W ratio for a certain exposure temperature.

  9. Natural growth, otolith shape and diet analyses of Odontesthes nigricans Richardson (Atherinopsidae) from southern Patagonia

    NASA Astrophysics Data System (ADS)

    Lattuca, M. E.; Lozano, I. E.; Brown, D. R.; Renzi, M.; Luizon, C. A.

    2015-12-01

    Age and growth, otolith shape and diet of Odontesthes nigricans were analysed in order to provide an insight into the life history of the species and furthermore, to assess their possible use as a tool for discriminating silverside populations from the South Atlantic Ocean (Punta María) and Beagle Channel waters (Varela Bay). The age and growth analysis was performed by counting daily increments and annual marks in sagittae otoliths. Length-at-age data of individuals <65 mm standard length (SL) were fitted to the Laird-Gompertz model (SLt = 6.22 exp 2.45 [1-exp (-0.02t)]), which provided an excellent description of the pattern of daily growth for O. nigricans juveniles from Varela Bay. The spawning period was also assessed through back-calculation of hatching dates and it extended from November to February. The count of annual marks in larger individuals identified 7 year classes (0+ to 6+) in Varela Bay and 6 year classes (0+ to 5+) in Punta María. The von Bertalanffy growth model explained more than 95% of the growth patterns observed in O. nigricans from Varela Bay (SLt = 245.49 [1 - exp -0.24(t+0.46)]) and Punta María (SLt = 345.09 [1 - exp -0.15(t+0.31)]). Particularly, k and SL∞ varied significantly between sampling sites; reaching Punta María a larger SL∞ value with a lower k. Otolith shape variation was also explored using elliptical Fourier analysis and it showed significant differences between Varela Bay and Punta María populations. Furthermore, gut content analysis characterized O. nigricans as an invertebrate predator, being benthic organisms the most important components of its diet, which also showed significant site dependence. The use of all these analyses contributed to a holistic approach which maximized the likelihood of correctly identifying both O. nigricans populations in the southernmost limit of the species distribution.

  10. [Diet, selectivity and trophic overlap between the sizes of silverside Menidia humboldtiana (Atheriniformes: Atherinopsidae) in the reservoir Tiacaque, Mexico].

    PubMed

    Sánchez, Regina; Ochoa, Abigahil; Mendoza, Angélica

    2013-06-01

    D Menidia humboldtiana, a native species of Mexico, is a common inhabitant of local reservoirs. It represents a highly appreciated fish of economic importance in the central part of the country because of its delicate flavor. Trophic behavior of this species is important to understand the relationships with other fish species in reservoirs. With the aim to study this specific topic, the trophic spectrum, selectivity coefficient and overlap, were determined among different sizes of the Silverside M humboldtiana. For this, both zooplankton and fish samples were taken during four different seasons of 1995. Zooplankton samples were taken through a mesh (125 micron), and all organisms were identified to generic level. Fish were captured and grouped into standard length intervals per season, and the stomach contents were obtained and analyzed. Trophic interactions included the stomach contents analysis (Laevastu method), the coefficient of selection (Chesson) and the trophic overlap (Morisita index modified by Horn) between sizes. A total of 14 zooplankton genera were identified, of which Bosmina was the most abundant (29 625 ind./10 L) followed by Cyclops (9496 ind./10 L), during the spring. Small size fishes (1-4.9cm) consumed high percentages of Cyclops in the spring (61.24%) and winter (69.82%). Ceriodaphnia was consumed by fish sizes of 3-10.9cm (72.41%) and 13-14.9cm (95.5%) during the summer; while in autumn, small sizes (1-4.9cm) ingested Mastigodiaptomus and Ceriodaphnia; Daphnia and Bosmina were consumed by fishes of 5-8.9cm and the biggest sizes (9-14.9 cm) feed on Ceriodaphnia. M. humboldtiana makes a selective predation by the genera Ceriodaphnia, Daphnia, Mastigodiaptomus, Bosmina and Cyclops, depending on the size length interval. The trophic overlap was very marked among all sizes on spring, autumn and winter, unlike in summer fish of 1-2.9 and 11-12.9 cm did not show overlap with other length intervals. M humboldtiana is a zooplanktivore species, which performs a selective predation and a marked trophic overlap between the different fish sizes. PMID:23885589

  11. Early development of Brycon orthotaenia (Pisces: Characidae).

    PubMed

    Gomes, Rafael Zeferino; Sato, Yoshimi; Rizzo, Elizete; Bazzoli, Nilo

    2013-02-01

    Brycon orthotaenia is an important fish for commercial and sport fishing and may reach 7 kg in body weight; it is endangered in some regions of Brazil's São Francisco River Basin. Breeders were subjected to spawning induction to analyse the early development; oocytes and semen were obtained by manual extrusion and fertilization was carried out using the dry method. After fertilization, eggs were kept in incubators at 24°C. Egg samples were collected every 10 min until hatching in order to monitor embryonic development and were analysed and photographed. Larvae samples were collected daily until the seventh day to analyse the larvae development; larvae were fixed in Bouin's fluid and subjected to routine histological and histochemical techniques for glycoprotein and glyco-conjugated detection. Oocyte extrusion occurred 6 h after the second hormone dose at 26°C. The recently extruded oocytes were spherical, dark green and non-adhesive, with a diameter of 1479.67 ± 53.18 and 3094.60 ± 80.34 μm after hydration. The blastopore closure occurred within 7 h 30 min of fertilization and the fertilization rate was 50.0 ± 5.5 % at 24°C. Embryonic development was completed within 21 h 30 min of fertilization. Complete yolk sac resorption and mouth opening occurred on the third day after hatching, at which time an adhesive organ with mucosubstances was observed. On the third day, an olfactory chamber with cilia and intense cannibalism amongst the larvae was observed. The complete differentiation of the digestive system occurred on the fifth day and the nervous and sensorial systems differentiation occurred on the sixth to seventh days. PMID:21733293

  12. Seasonal changes and endocrine regulation of pejerrey (Odontesthes bonariensis) spermatogenesis in the wild.

    PubMed

    Elisio, Mariano; Chalde, Tomás; Miranda, Leandro A

    2015-09-15

    The endocrine mechanisms that regulate spermatogenesis and their interaction with environmental cues have been poorly studied compared with oogenesis in fish. The aim of this work was to study the spermatogenesis in pejerrey under the influence of photoperiod and water temperature fluctuation in the wild, evaluating the transcript levels of brain Gnrh variants and cyp19a1b, pituitary Gth subunits, gonadal Gth receptors, 11β-hsd, and 11-KT plasma levels. Males at spermiogenic stage were observed during spring and autumn, under a photoperiod above 11h of light and a water temperature below 23 °C. Most arrested males were observed in summer when water temperatures increased above 23 °C. Males at spermatogonial stage were mainly observed in autumn, while most males at spermatocytary stage were caught in winter. An increase of gnrh-I, cyp19a1b, fshb, gpha and 11β-hsd transcripts and 11-KT plasma levels was observed during spermatogonial and/or spermatocytary stage (early spermatogenesis). The spermiogenic stage was associated to the maximum gnrh-I gene expression level and a significant increase of Gth receptors transcripts, being this fact more evident for lhcgr. During this last gonadal stage, cyp19a1b transcript level remained high, while fshb mRNA and 11-KT plasma levels showed a significant decreased compared to that occurred at the spermatocytary stage. Also, gphα and 11β-hsd gene expression levels fell during spermiation up to similar values to those observed in arrested males. A significant correlation between 11-KT and gnrh-I, cyp19a1b, gphα, fshb, 11β-hsd transcripts, and the number of spermatocytes was observed during spermatogenesis. All these findings suggested that in pejerrey, the spermatocyte proliferation occurs mainly during winter under the stimulation of 11-KT induced by FSH through the stimulation of specific enzymes, including the 11β-hsd while spermiation occurs after photoperiod increase and with temperatures of the water below 23 °C, through the stimulation of gnrh-I, cyp19a1b and lhcgr. PMID:25623146

  13. Eggs ultrastructure and early development of Franciscodoras marmoratus (Pisces: Doradidae).

    PubMed

    Alberto Weber, A; Sato, Y; Enemir Santos, J; Rizzo, E; Bazzoli, N

    2012-06-01

    This study presents, for the first time, information on the eggs and early development of Franciscodoras marmoratus, fish of São Francisco river, Brazil. To analyse the egg ultrastructure and morphological events of embryogenesis, a total of 36 F. marmoratus specimens (18 males and 18 females) were captured and subjected to spawning induction. Gametes were collected by manual extrusion, and fertilization was conducted using the dry method. After fertilization, eggs were kept in incubators with water temperature of 24°C. The embryonic development was monitored using a stereomicroscope until hatching. There was a 67% positive response to hypophysation by the females and the fertilization rate was 73.8 ± 6.2%. The oocytes are discoid, yellow, adhesive and covered by a thick jelly coat. Under the electron scanning microscope, the oocytes presented a surface with pore canals and funnel-shaped micropyle with a smooth vestibule. Recently extruded oocytes had a mean diameter of 1.27 ± 0.4 mm and after hydration was 1.91 ± 0.05 mm. The jelly coat was 0.34 ± 0.03 mm thickness, and the perivitelline space was 0.19 ± 0.04 mm. Eight phases of the embryonic development were identified, and embryogenesis was completed at 47 h after fertilization, at 24°C water temperature. The recently hatched larvae had 2.76 ± 0.57 mm of total length. These results provide useful information for the successful breeding and reproductive strategies of fishes. PMID:22150468

  14. Snakeheads (Pisces, Channidae): A biological synopsis and risk assessment

    USGS Publications Warehouse

    Courtenay, Walter R., Jr.; Williams, James D.

    2004-01-01

    Snakeheads (family Channidae) are airbreathing freshwater fishes containing two genera, Channa with 26 species native to Asia, Malaysia, and Indonesia; and Parachanna with 3 species native to tropical Africa. Some snakeheads are small, reaching about 17 centimeters, but most are much larger, the largest reported to be 1.8 meters in length. All are considered thrust predators with most being piscivorous as adults. A few of the smaller snakeheads and colorful juveniles of some larger ones have been available to hobbyists through the aquarium fish trade. Several species are highly valued as food fishes within parts of their native ranges, especially in Asia where they are an important part of capture fisheries and aquaculture. Because of these uses by humans, introductions far beyond native ranges have occurred. One Asian snakehead has been established in Oahu, Hawaii, since before 1900. Another species was discovered established in southeastern Florida in 2000, and a third in a pond in Maryland in 2002. Others have been captured from natural waters of the United States without evidence of reproduction and likely represent released aquarium fishes. That snakeheads at or near sexual maturity were being sold alive in ethnic food markets raised fears that they could be introduced into novel waters. These concerns led to this study on the biology of snakeheads. A risk assessment is included that examines environmental and related aspects of snakehead introductions.

  15. Relative gut lengths of coral reef butterflyfishes (Pisces: Chaetodontidae)

    NASA Astrophysics Data System (ADS)

    Berumen, M. L.; Pratchett, M. S.; Goodman, B. A.

    2011-12-01

    Variation in gut length of closely related animals is known to generally be a good predictor of dietary habits. We examined gut length in 28 species of butterflyfishes (Chaetodontidae), which encompass a wide range of dietary types (planktivores, omnivores, and corallivores). We found general dietary patterns to be a good predictor of relative gut length, although we found high variation among groups and covariance with body size. The longest gut lengths are found in species that exclusively feed on the living tissue of corals, while the shortest gut length is found in a planktivorous species. Although we tried to control for phylogeny, corallivory has arisen multiple times in this family, confounding our analyses. The butterflyfishes, a speciose family with a wide range of dietary habits, may nonetheless provide an ideal system for future work studying gut physiology associated with specialization and foraging behaviors.

  16. MICROSATELLITE CHARACTERIZATION IN CENTRAL STONEROLLER CAMPOSTOMA ANOMALUM (PISCES: CYPRINIDAE)

    EPA Science Inventory

    The central stoneroller (Campostoma anomalum) is a small cyprinid fish that is native to streams and rivers of central and eastern North America. It can be found in a range of anthropo- genically modified habitats, ranging from nearly pristine to highly polluted waters (Zimmerma...

  17. Brain aromatase (Cyp19A2) and estrogen receptors, in larvae and adult pejerrey fish Odontesthes bonariensis: Neuroanatomical and functional relations

    USGS Publications Warehouse

    Strobl-Mazzulla, P. H.; Lethimonier, C.; Gueguen, M.M.; Karube, M.; Fernandino, J.I.; Yoshizaki, G.; Patino, R.; Strussmann, C.A.; Kah, O.; Somoza, G.M.

    2008-01-01

    Although estrogens exert many functions on vertebrate brains, there is little information on the relationship between brain aromatase and estrogen receptors. Here, we report the cloning and characterization of two estrogen receptors, ?? and ??, in pejerrey. Both receptors' mRNAs largely overlap and were predominantly expressed in the brain, pituitary, liver, and gonads. Also brain aromatase and estrogen receptors were up-regulated in the brain of estradiol-treated males. In situ hybridization was performed to study in more detail, the distribution of the two receptors in comparison with brain aromatase mRNA in the brain of adult pejerrey. The estrogen receptors' mRNAs exhibited distinct but partially overlapping patterns of expression in the preoptic area and the mediobasal hypothalamus, as well as in the pituitary gland. Moreover, the estrogen receptor ??, but not ??, were found to be expressed in cells lining the preoptic recess, similarly as observed for brain aromatase. Finally, it was shown that the onset expression of brain aromatase and both estrogen receptors in the head of larvae preceded the morphological differentiation of the gonads. Because pejerrey sex differentiation is strongly influenced by temperature, brain aromatase expression was measured during the temperature-sensitive window and was found to be significantly higher at male-promoting temperature. Taken together these results suggest close neuroanatomical and functional relationships between brain aromatase and estrogen receptors, probably involved in the sexual differentiation of the brain and raising interesting questions on the origin (central or peripheral) of the brain aromatase substrate. ?? 2008 Elsevier Inc.

  18. Molecular Phylogeny and Zoogeography of the Capoeta damascina Species Complex (Pisces: Teleostei: Cyprinidae)

    PubMed Central

    Alwan, Nisreen; Esmaeili, Hamid-Reza; Krupp, Friedhelm

    2016-01-01

    Capoeta damascina was earlier considered by many authors as one of the most common freshwater fish species found throughout the Levant, Mesopotamia, Turkey, and Iran. However, owing to a high variation in morphological characters among and within its various populations, 17 nominal species were described, several of which were regarded as valid by subsequent revising authors. Capoeta damascina proved to be a complex of closely related species, which had been poorly studied. The current study aims at defining C. damascina and the C. damascina species complex. It investigates phylogenetic relationships among the various members of the C. damascina complex, based on mitochondrial and nuclear DNA sequences. Phylogenetic relationships were projected against paleogeographical events to interpret the geographic distribution of the taxa under consideration in relation to the area’s geological history. Samples were obtained from throughout the geographic range and were subjected to genetic analyses, using two molecular markers targeting the mitochondrial cytochrome oxidase I (n = 103) and the two adjacent divergence regions (D1-D2) of the nuclear 28S rRNA genes (n = 65). Six closely related species were recognized within the C. damascina complex, constituting two main lineages: A western lineage represented by C. caelestis, C. damascina, and C. umbla and an eastern lineage represented by C. buhsei, C. coadi, and C. saadii. The results indicate that speciation of these taxa is rather a recent event. Dispersal occurred during the Pleistocene, resulting in present-day distribution patterns. A coherent picture of the phylogenetic relationships and evolutionary history of the C. damascina species complex is drawn, explaining the current patterns of distribution as a result of paleogeographic events and ecological adaptations. PMID:27309854

  19. Mitochondrial and Allozyme Genetics of Incipient Speciation in a Landlocked Population of Galaxias Truttaceus (Pisces: Galaxiidae)

    PubMed Central

    Ovenden, J. R.; White, RWG.

    1990-01-01

    Galaxias truttaceus is found in coastal rivers and streams in south-eastern Australia. It spawns at the head of estuaries in autumn and the larvae spend 3 months of winter at sea before returning to fresh water. In Tasmania there are landlocked populations of G. truttaceus in a cluster of geologically young lakes on the recently glaciated Central Plateau. These populations have no marine larval stage and spawn in the lakes in spring. Speciation due to land locking is thought to be a frequent occurrence within Galaxias. To investigate the nature of the speciation event which may be occurring within lake populations of G. truttaceus we studied the mitochondrial DNA (mtDNA) and allozyme diversity of both lake and stream populations. Using the presence or absence of restriction sites recognized by 13 six-base restriction endonucleases, we found 58 mtDNA haplotypes among 150 fish collected from 13 Tasmanian and one south-east Australian mainland stream populations. The most parsimonious network relating the haplotypes by site loss or gain was starlike in shape. We argue that this arrangement is best explained by selection upon slightly beneficial mutations within the mitochondrial genome. Gene diversity analysis under Wright's island model showed that the populations in each drainage were not genetically subdivided. Only two of these stream haplotypes were found among the 66 fish analyzed from four lake populations. Despite the extreme lack of mtDNA diversity in lake populations, the observed nuclear DNA heterozygosity of 40 lake fish (0.10355) was only slightly less than that of 82 stream fish (0.11635). In the short time (3000-7000 years) that the lake fish have been landlocked, random genetic drift in a finite, stable-sized population was probably not responsible for the lack of mtDNA diversity in the lake populations. We infer the lake populations have probably experienced at least one, severe, but transitory bottleneck possibly induced by natural selection for life-history characters essential for survival in the lacustrine habitat. If speciation is occurring in the landlocked populations of G. truttaceus, then it may be driven by genetic transilience. PMID:2155855

  20. Biology of eggs, embryos and larvae of Rhinelepis aspera (Spix & Agassiz, 1829) (Pisces: Siluriformes).

    PubMed

    da Rocha Perini, Violeta; Sato, Yoshimi; Rizzo, Elizete; Bazzoli, Nilo

    2010-05-01

    The black armoured catfish Rhinelepis aspera is an important commercial species found in the São Francisco River (Brazil) that has great potential for pisciculture. This paper presents, for the first time, information on the embryogenesis and larval development of this species. The breeder fish were subjected to spawning induction with crude carp pituitary extract. Eggs were kept in incubators at 24 degrees C and embryogenesis was observed with a stereomicroscope until hatching. Ovary fragments, samples of recently extruded oocytes and larvae were fixed in Bouin's solution and subjected to routine histology techniques. Recently extruded oocytes were also analyzed with a scanning electron microscope (SEM). Females (80%) had a positive response to hypophysation. Oocyte extrusion was performed at 8 h and 30 min after the second hormone injection and the fertilization rate achieved 72.4 +/- 8.8%. Recently extruded oocytes had a mean diameter of 1360.80 +/- 40.87 microm and presented a conspicuous jelly coat covering the zona pellucida. Histochemical reactions indicated the presence of neutral glycoproteins in the yolk globules and in the zona pellucida. These reactions also indicated the presence of neutral glycoproteins and carboxylated acid glycoconjugates in the follicular cells and the jelly coat. These compounds form mucosubstances that can be related to the adhesiveness of the eggs. Under the SEM the oocytes presented a micropyle disc and a thick jelly coat over their surface. The closure of the blastopore occurred 9 h and 40 min after fertilization and embryogenesis was completed at 45 h and 50 min after fertilization, when the embryos were incubated at 24 degrees C. The total absorption of the yolk sac occurred during the fifth day indicating the need for an exogenous food supply. These results provide essential information for the successful breeding and management of the promising R. aspera. PMID:19860989

  1. Oocyte adhesiveness and embryonic development of Astyanax bimaculatus (Linnaeus, 1758) (Pisces: Characidae).

    PubMed

    Weber, André Alberto; Arantes, Fábio Pereira; Sato, Yoshimi; Rizzo, Elizete; Bazzoli, Nilo

    2013-05-01

    This study shows for the first time the presence of a jelly coat on oocytes of neotropical Characiformes fish. This structure could be responsible for the adhesiveness of Astyanax bimaculatus oocytes, a species widely distributed in South America including in the São Francisco River basin in Brazil. Adult specimens of A. bimaculatus were submitted to artificial reproduction in order to analyse the egg morphology and embryonic development. The eggs were fertilised and kept in incubators with a water temperature of 24°C so that embryogenesis could be monitored. Ovulated and unfertilised oocytes were also collected and submitted to routine histological techniques. Astyanax bimaculatus oocytes were found to be spherical, yellowish, and covered by a thin jelly coat with a slightly adhesive surface. The mean oocyte diameter was 1.03 ± 0.03 mm, the perivitelline space was 0.21 ± 0.02 mm and the jelly coat's thickness was 0.04 ± 0.01 mm. Positive periodic acid-Schiff (PAS) stain and Alcian blue stain pH 2.5 indicated the presence of neutral glycoproteins, and carboxylated acid glycoconjugates on the jelly coat that formed mucosubstances that may be associated with egg adhesiveness. At a water temperature of 24°C, blastopore closure and hatching occurred at 5 h and 17 h after fertilisation, respectively. The results of this study provide essential information for phylogenetic studies and for a better understanding of the reproductive strategy of A. bimaculatus, currently included in the incertae sedis group of the Characidae family due to the lack of monophyly among the families of the group. PMID:22717095

  2. Helminth parasites of Chapalichthys encaustus (Pisces: Goodeidae), an endemic freshwater fish from Lake Chapala, Jalisco, Mexico.

    PubMed

    Martínez-Aquino, Andrés; Salgado-Maldonado, Guillermo; Aguilar-Aguilar, Rogelio; Cabañas-Carranza, Guillermina; Ortega-Olivares, Mirza P

    2004-08-01

    A total of 6 helminth species were recorded during helminthological examination of 50 Chapalichthys encaustus from Lake Chapala, Jalisco, Mexico. Helminth species identified included: Salsuginus sp. (an undescribed monogenea); Posthodiplostomum minimum (metacercariae); Cyclustera ralli (metacestode); Polymorphus brevis (cystacanth); Contracaecum sp. (nematode larvae); and Rhabdochona lichtenfelsi (adult nematode). Of these, 2 (Salsuginus sp. and R. lichtenfelsi) are specialist species. The observed species richness, individual parasite abundance, and diversity were low. Data suggest that host specificity is an important factor contributing to observed community composition and richness. Host feeding habits and helminth species availability seem to determine the characteristics of these helminth assemblages. PMID:15357094

  3. Instrument Construction and Initial Validation: Professional Identity Scale in Counseling (PISC)

    ERIC Educational Resources Information Center

    Woo, Hong Ryun

    2013-01-01

    The advantages of having a strong professional identity include ethical performances, promoted wellness, and increased awareness of roles and functions among individual counselors (Brott & Myers, 1999; Grimmit & Paisley, 2008; Ponton & Duba, 2009). Scholars in the counseling field have underscored the importance of unified professional…

  4. Chromosomal distribution of microsatellite repeats in Amazon cichlids genome (Pisces, Cichlidae)

    PubMed Central

    Schneider, Carlos Henrique; Gross, Maria Claudia; Terencio, Maria Leandra; de Tavares, Édika Sabrina Girão Mitozo; Martins, Cesar; Feldberg, Eliana

    2015-01-01

    Abstract Fish of the family Cichlidae are recognized as an excellent model for evolutionary studies because of their morphological and behavioral adaptations to a wide diversity of explored ecological niches. In addition, the family has a dynamic genome with variable structure, composition and karyotype organization. Microsatellites represent the most dynamic genomic component and a better understanding of their organization may help clarify the role of repetitive DNA elements in the mechanisms of chromosomal evolution. Thus, in this study, microsatellite sequences were mapped in the chromosomes of Cichla monoculus Agassiz, 1831, Pterophyllum scalare Schultze, 1823, and Symphysodon discus Heckel, 1840. Four microsatellites demonstrated positive results in the genome of Cichla monoculus and Symphysodon discus, and five demonstrated positive results in the genome of Pterophyllum scalare. In most cases, the microsatellite was dispersed in the chromosome with conspicuous markings in the centromeric or telomeric regions, which suggests that sequences contribute to chromosome structure and may have played a role in the evolution of this fish family. The comparative genome mapping data presented here provide novel information on the structure and organization of the repetitive DNA region of the cichlid genome and contribute to a better understanding of this fish family’s genome. PMID:26753076

  5. Molecular systematics and biogeography of the circumglobally distributed genus Seriola (Pisces: Carangidae).

    PubMed

    Swart, Belinda L; von der Heyden, Sophie; Bester-van der Merwe, Aletta; Roodt-Wilding, Rouvay

    2015-12-01

    The genus Seriola includes several important commercially exploited species and has a disjunct distribution globally; yet phylogenetic relationships within this genus have not been thoroughly investigated. This study reports the first comprehensive molecular phylogeny for this genus based on mitochondrial (Cytb) and nuclear gene (RAG1 and Rhod) DNA sequence data for all extant Seriola species (nine species, n=27). All species were found to be monophyletic based on Maximum parsimony, Maximum likelihood and Bayesian inference. The closure of the Tethys Sea (12-20 MYA) coincides with the divergence of a clade containing ((S. fasciata and S. peruana), S. carpenteri) from the rest of the Seriola species, while the formation of the Isthmus of Panama (±3 MYA) played an important role in the divergence of S. fasciata and S. peruana. Furthermore, factors such as climate and water temperature fluctuations during the Pliocene played important roles during the divergence of the remaining Seriola species. PMID:26279346

  6. Comparative protein profiles: potential molecular markers from spermatozoa of Acipenseriformes (Chondrostei, Pisces).

    PubMed

    Li, Ping; Hulak, Martin; Rodina, Marek; Sulc, Miroslav; Li, Zhi-Hua; Linhart, Otomar

    2010-12-01

    Sturgeon and paddlefish (Acipenseriformes), the source of roe consumed as caviar, are a unique and commercially valuable group of ancient fishes. In this study, comparative proteomics was used to analyze protein profiles of spermatozoa from five sturgeon species and one paddlefish: Siberian sturgeon (Acipenser baerii), sterlet (A. ruthenus), Russian sturgeon (A. gueldenstaedtii), starry sturgeon (A. stellatus), beluga (Huso huso), and Mississippi paddlefish (Polyodon spathula). Protein profiles of spermatozoa were determined by isoelectric focusing and two-dimensional electrophoresis (2-DE) high-resolution gels. The peptides, previously selected by 2-DE analysis as potentially species-specific, were obtained by "in-gel" tryptic digestion, followed by matrix-associated laser desorption/ionization time-of-flight/mass spectrometry (MALDI-TOF/MS). Among the 23 protein spots selected, 14 were identified as isoforms of enolase B present in all species, but with different isoelectric points or molecular mass. Exceptions were A. ruthenus and H. huso, species with a close phylogenetic relationship. Glycerol-3-phosphate dehydrogenase was detected exclusively in P. spathula. Phosphoglycerate kinase was detected only in A. ruthenus and H. huso, and 3 additional proteins (fructose bisphosphate aldolase A-2, glycogen phosphorylase type IV and glyceraldehyde-3-phosphate dehydrogenase) were found exclusively in A. gueldenstaedtii and H. huso. This study points to the application of proteomics for differential characterization and comparative studies of acipenseriform species at the molecular level. PMID:20869341

  7. Rapid radiation and cryptic speciation in mediterranean triplefin blennies (Pisces: Tripterygiidae) combining multiple genes.

    PubMed

    Carreras-Carbonell, Josep; Macpherson, Enrique; Pascual, Marta

    2005-12-01

    The genus Tripterygion is the unique genus of the family Tripterygiidae in the Mediterranean Sea and in the northeastern Atlantic coast. Three species and four subspecies had been described: Tripterygion tripteronotus and Tripterygion melanurus (T. m. melanurus and T. m. minor) are endemic of the Mediterranean, and T. delaisi (T. d. delaisi and T. d. xanthosoma) is found in both areas. We used five different genes (12S, 16S, tRNA-val, COI, and 18S) to elucidate their taxonomy status and their phylogenetic relationships. We employed different phylogenetic reconstructions that yielded different tree topologies. This discrepancy may be caused by the speciation process making difficult the reconstruction of a highly supported tree. All pair comparisons between these three species showed the same genetic divergence indicating that the speciation process could have been resolved by a rapid radiation event after the Messinian Salinity Crisis (5.2Mya) leading to a trichotomy. Our molecular data revealed two clearly supported clades within T. tripteronotus, whose divergence largely exceeded that found between other fish species, consequently these two groups should be considered two cryptic species diverging 2.75-3.32Mya along the Pliocene glaciations. On the contrary, none of the genes studied supported the existence of two subspecies of T. melanurus. Finally, the two subspecies of T. delaisi were validated and probably originated during the Quaternary climatic fluctuations (1.10-1.23Mya), however their distribution ranges should be redefined. PMID:15964768

  8. Oxidative stress enzyme and histopathological lesions in Colossoma macropomum (pisces, ariidae) for environmental impact assessment

    NASA Astrophysics Data System (ADS)

    Andrade, Ticianne de Sousa de Oliveira Mota; Sousa, Debora Batista Pinheiro; Dantas, Janaina Gomes; Castro, Jonatas da Silva; Neta, Raimunda Nonata Fortes Carvalho

    2015-12-01

    This study used oxidative stress enzyme (Glutathione S-Transferase and Catalase), histopathological lesions (Branchial lesions) and biometric data in the freshwater fish tambaqui, Colossoma macropomum, to assess environmental impacts in an Environmental Protection Area at São Luis, Brazil. Fish were sampled from two locations (A1 = contaminated area and A2 = reference site) within the protected area on four occasions. The activity of catalase (CAT) and glutathione S-transferase (GST) in C. macropomum was compared with biometric data and histopathological lesions. Results have shown that biometric data decreased significantly in fish (p<0.05) at the contaminated site. The activity of CAT was higher in fish specifically caught in A1. A significant difference was observed in the GST activity in the liver of C. macropomum when comparing fish from the contaminated site and those from the reference site (p<0.05).

  9. Chromosomal Variability Between Populations of Electrophorus electricus Gill, 1864 (Pisces: Gymnotiformes: Gymnotidae).

    PubMed

    Cardoso, Adauto Lima; Ready, Jonathan Stuart; Pieczarka, Julio Cesar; Milhomem, Susana Suely Rodrigues; de Figueiredo-Ready, Wilsea Maria Batista; Silva, Fernando Henrique Ramos; Nagamachi, Cleusa Yoshiko

    2015-12-01

    The electric eel, Electrophorus electricus, the only species of its genus, has a wide distribution in the Amazon and Orinoco drainages. There is little previous information regarding the population variation in E. electricus, with only basic karyotype data from two populations (Amazon and Araguaia Rivers). Karyotypic description and analysis of CO1 barcode sequences were performed for E. electricus from three localities (Caripetuba, Irituia, and Maicuru Rivers). All samples share the 2n=52 (42 m-sm [meta-submetacentric] +10 st-a [subtelo-acrocentric]) with previously studied material. However, the Maicuru River samples differ from the other populations, as they have B chromosomes. The distribution of noncentromeric constitutive heterochromatin between samples is relatively divergent. All samples analyzed present the Nucleolar Organizer Region (NOR) located in a single chromosome pair. In the samples from Caripetuba, NORs were colocalized with a heterochromatin block, whereas the NOR was flanked by heterochromatin in Maicuru River samples and pericentromeric heterochromatin adjacent NOR was found in Irituia River samples. Alignment of CO1 barcode sequences indicated no significant differentiation between the samples analyzed. Results suggest that karyotypic differences between samples from the Caripetuba, Irituia, and Amazon Rivers represent chromosome polymorphisms. However, differences between the samples from the Maicuru and Araguaia Rivers and the remaining populations could represent interpopulation differentiation, which has not had time to accrue divergence at the CO1 gene level. PMID:25695141

  10. Phylogenetic relationships among Spanish Barbus species (Pisces, Cyprinidae) shown by RAPD markers.

    PubMed

    Callejas, C; Ochando, M D

    2002-07-01

    Random amplified polymorphic DNA (RAPD) markers were used to estimate the population structure and phylogenetic relationships among the eight species of the genus Barbus that inhabit the Iberian Peninsula. Ten random oligodecamers were used to amplify DNA from 232 fish sampled from 15 populations. A total of 270 markers were detected that revealed low levels of genetic variability. The conclusions of cluster analysis indicate two main branches and three well-differentiated groups: north-eastern, Mediterranean and Atlantic. This clustering mainly reflects the evolutionary history of the genus, which is closely related to the paleogeography of the Iberian Peninsula. The contribution and application of these results to the conservation of the species, to their taxonomic status and to the process of colonization of the Iberian Peninsula by the genus Barbus are discussed. PMID:12080368

  11. [Micropterus salmoides (Pisces: Centrarchidae) reproduction in the Gustavo Diaz Ordaz reservoir, Sinaloa, México].

    PubMed

    Beltrán Alvarez, Rigoberto; Sánchez Palacios, Jesús; Ramírez Lozano, Juan Pedro; Ortega Salas, Adolfo-Armando

    2013-09-01

    Micropterus salmoides is an important fish species for sport fishing activities, condition that has promoted its introduction to different reservoirs in Mexico and worldwide. With the aim to improve its fisheries management, this research dealt with some reproductive aspects of this species in the Gustavo Diaz Ordaz reservoir, where it was studied from August 2008 through March 2011. To this end, we obtained 938 specimens, with gillnets of different sizes, to determine their total length (Lt, in cm), weight (Pt, in g), sex, gonadosomatic index, condition factor, fecundity and size at first maturity. Lt and Pt ranged from 15.9 to 63 cm (37.4 +/- 78.0) and 57 to 4431 g (731.7 +/- 619.0), respectively. The Pt-Lt relationship showed a positive allometric growth, with no significant difference between males and females (F = 0.9955, p = 0.3187). The male: female ratio obtained was 1:0.83. Mass spawning lasted from December to April. Size at first maturity was 33.7 cm and average fecundity was 32294 +/- 12878.7 oocytes/female. The gonadosomatic index was low from May through November, and increased between January and March. The condition factor was high before the spawning season and decreased after the reproductive period. We recommend a fishing ban from January to March, and to allow the capture size between 33 and 40 cm. PMID:24027925

  12. Homing behaviour and individual identification of the pipefish Nerophis lumbriciformis (Pisces; Syngnathidae): a true intertidal resident?

    NASA Astrophysics Data System (ADS)

    Monteiro, Nuno Miguel; Vieira, Maria da Natividade; Almada, Vitor

    2005-04-01

    Syngnathids have been the focus of growing interest due to their peculiar reproductive biology and vulnerability to environmental degradation and overcollecting. In this study, near the south limit of the species' geographic distribution, a description of the homing behaviour of the worm pipefish, Nerophis lumbriciformis, based on the unique facial pigmentation patterns, is presented. Even though the amount of facial pigmentation was substantially higher in larger adult females, suggesting that it can be part of the secondary sexual repertoire of this sex role reversed species, this technique allowed for the positive identification of adult individuals (males and females) during at least 19 months. Recaptures showed that this pipefish shows a strong homing behaviour, with individuals being regularly captured within less than 2 m of the original identification event. The absence of horizontal migrations to adjacent areas and the observation of adults in the subtidal, together with the overall low number of recaptures (even though some individuals were cyclically resighted) highlighted the fact that the intertidal is not N. lumbriciformis' permanent residence. This observation also demonstrates that the estimation of the population size, important for conservation purposes, based solely on intertidal data can be misleading because captured individuals are only a fraction of a larger, mainly subtidal, population.

  13. Morphological characteristics and distribution of Pleuronectidae (Pisces) eggs in the western margin of the East Sea

    NASA Astrophysics Data System (ADS)

    Lee, Soo Jeong; Kim, Jin-Koo

    2016-03-01

    Seven species of Pleuronectidae ( Platichthys stellatus, Kareius bicoloratus, Pseudopleuronectes herzensteini, Microstomus achne, Glyptocephalus stelleri, Hippoglossoides dubius, and Limanda punctatissima) were identified based on eggs collected from the western margin of the East Sea (east coast of Korea), using DNA barcoding. The eggs of P. herzensteini and G. stelleri were relatively widely distributed along the east coast of Korea, whereas those of P. stellatus and K. bicoloratus were narrowly distributed; in particular, the eggs of P. stellatus were restricted to areas near bays. The eggs, which share common morphological characteristics (such as a homogeneous yolk and smooth membrane) were divided into three groups according to egg size: group A (more than 1.60 mm in egg diameter, including genera Hippoglossoides and Microstomus), group B (1.00-1.60 mm, including genera Kareius, Glyptocephalus, and Platichthys), and group C (less than 1.00 mm, including genera Limanda and Pseudopleuronectes). This paper provides an overview of the morphological characteristics of the eggs of the family Pleuronectidae collected from the east coast of Korea. Our approach to the analysis of eggs, based on DNA barcoding, morphological characteristics, and geographic distributions, provides a rapid and accurate basis for identifying spawning areas and spawning periods, thus facilitating the assessment and management of fisheries stocks and resources.

  14. Bone development in the jaw of Nile tilapia Oreochromis niloticus (Pisces: Cichlidae).

    PubMed

    Fujimura, Koji; Okada, Norihiro

    2008-06-01

    East African cichlids have evolved feeding apparatus morphologies adapted to their diverse feeding behaviors. The evolution of the oral jaw morphologies is accomplished by the diversity of bone formation during development. To further understand this evolutionary process, we examined the skeletal elements of the jaw and their temporal and sequential emergence, categorized by developmental stages, using the Nile tilapia Oreochromis niloticus as a model cichlid. We found that chondrogenesis started in Stage 17. The deposition of osteoid for the dermal bones commenced in Stage 18. The uptake of calcium dramatically shifted from the surface of larvae to the gills in Stage 20. The bone mineralization of the skeleton began in Stage 25. These data provide important information regarding the sequential events of craniofacial development in East African cichlids and lay the groundwork for studying the molecular mechanisms underlying adaptation of jaw structure to feeding behavior. PMID:18430028

  15. Slingshot feeding of the goblin shark Mitsukurina owstoni (Pisces: Lamniformes: Mitsukurinidae)

    PubMed Central

    Nakaya, Kazuhiro; Tomita, Taketeru; Suda, Kenta; Sato, Keiichi; Ogimoto, Keisuke; Chappell, Anthony; Sato, Toshihiko; Takano, Katsuhiko; Yuki, Yoshio

    2016-01-01

    Five striking and prey capture events of two goblin sharks were videotaped at sea for the first time, showing their extraordinary biting process. The goblin sharks swung their lower jaw downward and backward to attain a huge gape and then rapidly protruded the jaws forward a considerable distance. The jaws were projected at a maximum velocity of 3.1 m/s to 8.6–9.4% of the total length of the shark, which is by far the fastest and greatest jaw protrusion among sharks. While the jaws were being retracted, the mouth opened and closed again, which was considered a novel feeding event for sharks. Phylogenetic evidence suggested that their feeding behavior has evolved as an adaptation to food-poor deep-sea environments, possibly as a trade-off for the loss of strong swimming ability. PMID:27282933

  16. Deep-water chaunacid and lophiid anglerfishes (Pisces: Lophiiformes) off the south-eastern United States

    USGS Publications Warehouse

    Caruso, John H.; Ross, S.W.; Sulak, K.J.; Sedberry, G.R.

    2007-01-01

    Recent research cruises to deep (80-910 m) reef habitats off the south-eastern U.S. and in the northern Gulf of Mexico have provided new information on the diagnostic characteristics, behaviours, colour patterns in life, bottom associations, distributions and maximum sizes of species of the anglerfish genera Chaunax, Lophiodes and Sladenia. Chaunax stigmaeus occurred much further south than previously known (Blake Plateau off South Carolina), and all C. stigmaeus observed were found associated with dense beds of dead coral (Lophelia pertusa) rubble or on broken hard bottom. In contrast, Chaunax suttkusi was found on soft bottoms. Chaunax stigmaeus and C. suttkusi appear to be sympatric over a major portion of their ranges. Because knowledge of pigmentation in live or freshly caught Chaunax is critical to distinguish some members of the genus, changes in the colouration of C. suttkusi were noted and documented photographically immediately after death and after fixation. The yellow spots found on some, but not all specimens, temporarily disappeared completely after death, but they reappeared after fixation, slowly disappearing thereafter along with other carotenoid pigments. Lophiodes beroe and Lophiodes monodi were collected for the first time off the Atlantic coast of the U.S., being previously known only from the Gulf of Mexico, Caribbean Sea and the northern coast of South America. For both species (L. beroe and L. monodi), the collections included the two largest known representatives of the species (400 and 325 mm standard length, respectively). Lophiodes beroe commonly occurred on L. pertusa rubble, and seemed to prefer this habitat. Occupying such a habitat that is deep and difficult to sample probably explains how this common species escaped detection. Only a single L. monodi was collected or observed, so this species appears to be uncommon in this geographic area or at least so on coral rubble habitat. Detailed aspects of the colour patterns of both species were noted. In particular, L. beroe displayed a characteristic pattern of white patches in life that were not apparent after death. The first photographic documentation of the colour pattern in life and of the pharyngeal pigmentation of Lophiodes reticulatus is provided. The third known specimen of Sladenia shaefersi, and the first to be taken in U.S. waters was collected from coral rubble near the base of a steep 200 m scarp on the Blake Plateau. ?? 2007 The Fisheries Society of the British Isles.

  17. Deep-water chaunacid and lophiid anglerfishes (Pisces: Lophiiformes) off the Southeastern United States

    USGS Publications Warehouse

    Caruso, John H.; Ross, S.W.; Sulak, Kenneth J.; Sedberry, George R.

    2007-01-01

    Recent research cruises to deep (80–910 m) reef habitats off the south-eastern U.S. and in the northern Gulf of Mexico have provided new information on the diagnostic characteristics, behaviours, colour patterns in life, bottom associations, distributions and maximum sizes of species of the anglerfish genera Chaunax, Lophiodes and Sladenia. Chaunax stigmaeus occurred much further south than previously known (Blake Plateau off South Carolina), and all C. stigmaeusobserved were found associated with dense beds of dead coral (Lophelia pertusa) rubble or on broken hard bottom. In contrast, Chaunax suttkusi was found on soft bottoms. Chaunax stigmaeusand C. suttkusi appear to be sympatric over a major portion of their ranges. Because knowledge of pigmentation in live or freshly caught Chaunax is critical to distinguish some members of the genus, changes in the colouration of C. suttkusi were noted and documented photographically immediately after death and after fixation. The yellow spots found on some, but not all specimens, temporarily disappeared completely after death, but they reappeared after fixation, slowly disappearing thereafter along with other carotenoid pigments. Lophiodes beroe andLophiodes monodi were collected for the first time off the Atlantic coast of the U.S., being previously known only from the Gulf of Mexico, Caribbean Sea and the northern coast of South America. For both species (L. beroe and L. monodi), the collections included the two largest known representatives of the species (400 and 325 mm standard length, respectively). Lophiodes beroecommonly occurred on L. pertusa rubble, and seemed to prefer this habitat. Occupying such a habitat that is deep and difficult to sample probably explains how this common species escaped detection. Only a single L. monodi was collected or observed, so this species appears to be uncommon in this geographic area or at least so on coral rubble habitat. Detailed aspects of the colour patterns of both species were noted. In particular, L. beroe displayed a characteristic pattern of white patches in life that were not apparent after death. The first photographic documentation of the colour pattern in life and of the pharyngeal pigmentation of Lophiodes reticulatus is provided. The third known specimen of Sladenia shaefersi, and the first to be taken in U.S. waters was collected from coral rubble near the base of a steep 200 m scarp on the Blake Plateau.

  18. REPRODUCTIVE ECOLOGY AND SPAWNING PERIODICITY OF THE ATLANTIC SILVERSIDE, 'MENIDIA MENIDIA' (PISCES: ATHERINIDAE)

    EPA Science Inventory

    The reproduction ecology and spawning periodicity of the Atlantic silverside, Menidia menidia, living in the North Edisto River estuary, South Carolina, was studied at two sites, Bears Bluff and the Point of Pines, during the spring and summer of 1976, 1977, and 1978. A specific ...

  19. Feeding of the megamouth shark (Pisces: Lamniformes: Megachasmidae) predicted by its hyoid arch: a biomechanical approach.

    PubMed

    Tomita, Taketeru; Sato, Keiichi; Suda, Kenta; Kawauchi, Junro; Nakaya, Kazuhiro

    2011-05-01

    Studies of the megamouth shark, one of three planktivorous sharks, can provide information about their evolutionary history. Megamouth shark feeding has never been observed in life animals, but two alternative hypotheses on biomechanics suggest either feeding, i.e., ram feeding or suction feeding. In this study, the second moment of area of the ceratohyal cartilages, which is an indicator of the flexural stiffness of the cartilages, is calculated for 21 species of ram- and suction-feeding sharks using computed tomography. The results indicate that suction-feeding sharks have ceratohyal cartilages with a larger second moment of area than ram-feeding sharks. The result also indicates that the ram-suction index, which is an indicator of relative contribution of ram and suction behavior, is also correlated with the second moment of area of the ceratohyal. Considering that large bending stresses are expected to be applied to the ceratohyal cartilage during suction, the larger second moment of area of the ceratohyal of suction-feeding sharks can be interpreted as an adaptation for suction feeding. Based on the small second moment of area of the ceratohyal cartilage of the megamouth shark, the feeding mode of the megamouth shark is considered to be ram feeding, similar to the planktivorous basking shark. From these results, an evolutionary scenario of feeding mechanics of three species of planktivorous sharks can be suggested. In this scenario, the planktivorous whale shark evolved ram feeding from a benthic suction-feeding ancestor. Ram feeding in the planktivorous megamouth shark and the basking shark evolved from ram feeding swimming-type ancestors and that both developed their unique filtering system to capture small-sized prey. PMID:21381075

  20. Social Inhibition of Maturation in Natural Populations of Xiphophorus variatus (Pisces: Poeciliidae).

    PubMed

    Borowsky, R

    1978-09-01

    According to analyses of field samples, social inhibition of maturation is at work in natural populations of the variable platyfish, Xiphophorus variatus. In the laboratory, adult males inhibit the maturation of juveniles; the inhibition is overcome as the juveniles increase in size. The proportion of maturing males in any field collection is related to the number of adult males present and the size of the juveniles. The more adults, the fewer maturing males are present; the larger the average juvenile, the greater the number of males maturing. The evolution of this system is best understood in terms of individual selection, but consequences of the system buffer the population against the effects of predation. PMID:17729573

  1. Communities of parasite metazoans in Piaractus brachypomus (Pisces, Serrasalmidae) in the lower Amazon River (Brazil).

    PubMed

    Oliveira, Marcos Sidney Brito; Tavares-Dias, Marcos

    2016-06-14

    The aim of this study was to investigate the component community of parasite metazoans of Piaractus brachypomus in the lower Amazon River, northern Brazil. From 34 necropsied fish, 27,384 metazoan parasites were collected, such as Anacanthorus spathulatus, Mymarothecium viatorum and Notozothecium janauachensis (Monogenoidea); Spectatus spectatus and Contracaecum sp (Nematoda); Clinostomum marginatum and Dadaytrema oxycephala (Digenea); and Argulus carteri and Ergasilus sp. (Crustacea). The dominant species was S. spectatus followed by monogenoidean species, and there was aggregated dispersion of parasites, except for D. oxycephala and Contracaecum sp., which presented random dispersion. Positive correlation among the abundance of the three monogenoideans species were found, thus indicating that there was no competition between the species of these parasites on the gills of hosts. The abundances of some parasite species showed positive correlations with the size of the hosts, but the condition factor of the fish was not affected by the parasitism levels. It showed that this host had a metazoan community characterized by high species richness of metazoans, low evenness and high diversity of parasites, with prevalence of endoparasites, including larval stages. This was the first record of C. marginatum, A. carteri, Ergasilus sp. and Contracaecum sp. for P. brachypomus. PMID:27304520

  2. Communities of parasite metazoans in Piaractus brachypomus (Pisces, Serrasalmidae) in the lower Amazon River (Brazil).

    PubMed

    Oliveira, Marcos Sidney Brito; Tavares-Dias, Marcos

    2016-06-14

    The aim of this study was to investigate the component community of parasite metazoans of Piaractus brachypomus in the lower Amazon River, northern Brazil. From 34 necropsied fish, 27,384 metazoan parasites were collected, such as Anacanthorus spathulatus, Mymarothecium viatorum and Notozothecium janauachensis (Monogenoidea); Spectatus spectatus and Contracaecum sp (Nematoda); Clinostomum marginatum and Dadaytrema oxycephala (Digenea); and Argulus carteri and Ergasilus sp. (Crustacea). The dominant species was S. spectatus followed by monogenoidean species, and there was aggregated dispersion of parasites, except for D. oxycephala and Contracaecum sp., which presented random dispersion. Positive correlation among the abundance of the three monogenoideans species were found, thus indicating that there was no competition between the species of these parasites on the gills of hosts. The abundances of some parasite species showed positive correlations with the size of the hosts, but the condition factor of the fish was not affected by the parasitism levels. It showed that this host had a metazoan community characterized by high species richness of metazoans, low evenness and high diversity of parasites, with prevalence of endoparasites, including larval stages. This was the first record of C. marginatum, A. carteri, Ergasilus sp. and Contracaecum sp. for P. brachypomus. PMID:27334815

  3. Initial development of Prochilodus hartii (Pisces: Prochilodontidae) submitted to induced reproduction.

    PubMed

    Abdo, Tiago Figueiredo; Perrotti, Paulo Brant; Meireles, Wesley Antunes; Bazzoli, Nilo

    2016-06-01

    The Prochilodontidae prepare for reproduction in captivity, but neither ovulation nor spawning occurs, thus requiring induced reproduction for breeding and restocking. This study analyzed for the first time the embryogenesis and larval ontogeny of P. hartii submitted to induced reproduction by hypophysation with crude common carp pituitary extract. The extrusion of oocytes and sperm was performed manually and fertilization was done using the dry method. After fertilization, the eggs were kept in incubators at 23°C. A stereomicroscope was used to measure egg diameter and to monitor embryo development. Samples of larvae were collected daily for 7 days for histological and biometric analyses. The recently extruded oocytes, non-hydrated, are spherical, grey, and non-adhesive with a diameter of 1480 ± 39 μm and after hydration, have a diameter of 2860 ± 120 μm. The positive response to hypophysation was 100% for females and 80% for males. Spawning occurred 7 h after the third hormonal dosage. The fertilization rate was 77% at 23°C. Blastopore closure occurred at 6 h 45 min and embryonic development was completed 36 h 10 min after fertilization. After 204 h post fertilization (hpf) the larvae reached a standard length of 6.56 ± 0.14 mm with the yolk sac completely resorbed. In P. hartii, the oral cavity opening occurred 132 hpf. The results of this study provide knowledge to better understand induced reproduction, breeding, and management of P. hartii, a species with a high potential for pisciculture, and which is commercially important in the Jequitinhonha River basin. PMID:26199056

  4. [Comparative cytotaxonomy of 3 species of Cichlasoma (Pisces: Cichlidae) native of Costa Rica].

    PubMed

    Salas, E; Boza, J

    1991-11-01

    The karyotype of three species of Cichlasoma: C. dovii, C. managuense and C. friedrichstali were studied. The number of diploid chromosomes is 2n = 48 in the first two species. Their karyotypes are composed of four pairs of meta-submetacentric chromosomes. The arms fundamental number (NF) is 56. C. friedrichstali has three pairs of meta-submetacentric chromosomes and 21 pairs of subtelocentric-telocentric chromosomes. This species presents two different diploid numbers, 2n = 48 and 2n = 47. PMID:1844157

  5. Molecular Phylogeny and Zoogeography of the Capoeta damascina Species Complex (Pisces: Teleostei: Cyprinidae).

    PubMed

    Alwan, Nisreen; Esmaeili, Hamid-Reza; Krupp, Friedhelm

    2016-01-01

    Capoeta damascina was earlier considered by many authors as one of the most common freshwater fish species found throughout the Levant, Mesopotamia, Turkey, and Iran. However, owing to a high variation in morphological characters among and within its various populations, 17 nominal species were described, several of which were regarded as valid by subsequent revising authors. Capoeta damascina proved to be a complex of closely related species, which had been poorly studied. The current study aims at defining C. damascina and the C. damascina species complex. It investigates phylogenetic relationships among the various members of the C. damascina complex, based on mitochondrial and nuclear DNA sequences. Phylogenetic relationships were projected against paleogeographical events to interpret the geographic distribution of the taxa under consideration in relation to the area's geological history. Samples were obtained from throughout the geographic range and were subjected to genetic analyses, using two molecular markers targeting the mitochondrial cytochrome oxidase I (n = 103) and the two adjacent divergence regions (D1-D2) of the nuclear 28S rRNA genes (n = 65). Six closely related species were recognized within the C. damascina complex, constituting two main lineages: A western lineage represented by C. caelestis, C. damascina, and C. umbla and an eastern lineage represented by C. buhsei, C. coadi, and C. saadii. The results indicate that speciation of these taxa is rather a recent event. Dispersal occurred during the Pleistocene, resulting in present-day distribution patterns. A coherent picture of the phylogenetic relationships and evolutionary history of the C. damascina species complex is drawn, explaining the current patterns of distribution as a result of paleogeographic events and ecological adaptations. PMID:27309854

  6. Dentex carpenteri, a new species of deepwater seabream from Western Australia (Pisces: Sparidae).

    PubMed

    Iwatsuki, Yukio; Newman, Stephen J; Russell, Barry C

    2015-01-01

    A new species of sparid fish, Dentex carpenteri, is described from nine type specimens collected off Ningaloo Reef near Exmouth, Western Australia. Four valid species of Dentex are currently known in the western Pacific, Dentex abei and D. hypselosomus in the Northern Hemisphere, and D. fourmanoiri and D. spariformis in the Southern Hemisphere. These four species comprise the "Dentex hypselosomus complex". Dentex carpenteri n. sp. is most similar to D. spariformis in overall body form, but differs from D. spariformis in having the posterior margin of the upper jaw not reaching or reaching slightly beyond a vertical at the anterior margin of eye; often with the greater part from the snout to the second infraorbital yellowish; deeper suborbital (9.7-10.9% SL); and a considerably deeper body (vs. posterior margin of upper jaw reaching clearly beyond anterior margin of eye; slight yellow region on snout; suborbital depth shallow (7.6-9.6% SL); and a less deep body in D. spariformis). The mitochondrial 16S ribosomal RNA genes (16S rRNA, 545 bp) of the above five species were analyzed using the Atlantic congener, Dentex macrophthalmus as an out-group, the results clearly indicating that D. carpenteri n. sp. is a valid and distinct species. A key to the "Dentex hypselosomus complex" is provided. The distributional information available for the five species from the western Pacific, including western Australia and the nearby eastern Indian Ocean, are discussed, with the species considered to be allopatric. PMID:26249058

  7. VizieR Online Data Catalog: HI datacubes if Pisces A and B (Carignan+, 2016)

    NASA Astrophysics Data System (ADS)

    Carignan, C.; Libert, Y.; Lucero, D. M.; Randriamampandry, T. H.; Jarrett, T. H.; Oosterloo, T. A.; Tollerud, E. J.

    2016-02-01

    The observations were obtained with the seven-dish KAT-7 array, located close to the South African SKA core site in the Northern Cape's Karoo desert region. The data were collected between 2014 November 27 and 2014 December 16. (2 data files).

  8. Description of larvae of the Feather Blenny, Hypsoblennius hentz (Pisces: Blenniidae), from New York Waters.

    PubMed

    Schmidt, Robert E; Moccio, Paul A

    2013-01-01

    Hypsoblennius hentz (Lesueur) larvae are described from specimens recently collected in the vicinity of New York Harbor and Raritan Bay. Previous descriptions (Hildebrand and Cable 1938) were erroneous and additionally we provide the first yolk-sac larval descriptions for Western Atlantic Hypsoblennius. H. hentz larvae are distinguished from the other Atlantic species by the size and distribution of preopercular spines. PMID:26213782

  9. Ultrastructural changes in female hepatocytes during ovarian maturation of Steindachnerina insculpta (Pisces: Curimatidae).

    PubMed

    Ribeiro, V M A; Bazzoli, N; Maria, T A; Santos, G B

    2006-11-01

    During gonadal maturation the females of Steindachnerina insculpta, a teleost of the Furnas reservoir, Minas Gerais, Brazil, show low hepatosomatic and high gonadossomatic indexes, suggesting possible transference of hepatic substances to the ovaries. In comparison to the resting phase, in the maturation/ mature one the hepatocytes show greater development of both smooth and rough endoplasmic reticula, increased electron density in the mitochondria, and glycogen scattered throughout the cytoplasm. In both resting and maturation/mature phases, the hepatic parenchyma contains melanomacrophagic centers that consist of degenerating cellular debris and are surrounded by capsules formed by cells, resembling fibroblasts, joined by desmosomes. No physiological relation of these centers with ovarian maturation was found. PMID:17299931

  10. Cytogenetic analyses of two Curimatidae species (Pisces; Characiformes) from the Paranapanema and Tietê Rivers.

    PubMed

    De Rosa, L V S; Foresti, F; Martins, C; Oliveira, C; Sobrinho, P E; Wasko, A P

    2007-05-01

    Cytogenetic analyses were performed in two Curimatidae species (Steindachnerina insculpta and Cyphocharax modesta) from the Paranapanema and Tietê Rivers (São Paulo State, Brazil), showing a karyotype composed of 54 meta-submetacentric chromosomes in both species. Silver- and chromomycyn-staining and fluorescent in situ hybridization (FISH) using a 18S rDNA probe indicated that the nucleolar organizer regions (NORs) of both species are localized in the terminal region of the long arm of two metacentric chromosomes. Although a single NOR system was evidenced in both analyzed species, S. insculpta and C. modesta presented the nucleolar organizer regions in distinct chromosome pairs, indicating that these cistrons can be considered cytogenetic markers. Variation on the amount and distribution of the constitutive heterochromatin (C-bands) could also be detected between the two species - while S. insculpta presented few heterochromatic blocks, intensely stained C-bands were evidenced in C. modesta specially in the terminal region of the long arm of the NOR-bearing chromosomes. Although most Curimatidae species have been characterized by homogeneous karyotypes, isolated populations could be established under different environmental conditions leading to karyotype micro-structure variations specially related to the NORs localization and C-banding distribution. The obtained data were useful for the cytogenetic characterization and differentiation of S. insculpta and C. modesta and could be used in evolutionary inferences in the Curimatidae group. PMID:17876445

  11. Alkaline comet assay for genotoxic effect detection in neotropical fish Prochilodus lineatus (Pisces, Curimatidae).

    PubMed

    Simoniello, M F; Gigena, F; Poletta, G; Loteste, A; Kleinsorge, E; Campana, M; Scagnetti, J; Parma, M J

    2009-08-01

    Toxicants on fish may induce genetic alterations that can be used as genotoxic markers. We evaluated DNA damage using alkaline comet assay applied on erythrocytes after in vivo exposure of Prochilodus lineatus to different concentrations of Cypermethrin (0.300, 0.150, 0.075 and 0.000 microg/L) as a probable chemical mutagen. The results revealed a significantly higher level of DNA damage at all concentrations of Cypermethrin tested compared to control and background level (p < 0.05). We have standardized the technique for one of the most common native fish species that will be useful for biomonitoring genotoxicity in polluted waters of the region. PMID:19466374

  12. Comparative cytogenetic studies of Curimatidae (Pisces, Characiformes) from the middle Paraná River (Argentina).

    PubMed

    Brassesco, M S; Pastori, M C; Roncati, H A; Fenocchio, A S

    2004-01-01

    Almost all species of the Curimatidae family have a stable karyotype, with a diploid number of 54 metacentric (M) and submetacentric (SM) chromosomes, and one sole nucleolus organizer pair. This family has considerable specific diversity in Argentinean fluvial basins; however, no cytogenetic data are available. Eight species from the Paraná River (Argentina): Cyphocharax voga, C. spilotus, C. platanus, Steindachnerina brevipinna, S. conspersa, Curimatella dorsalis, Psectrogaster curviventris, and Potamorhina squamoralevis were analyzed cytogenetically. Chromosome preparations were obtained from direct samples and through cell culture, and they were processed for conventional, C- and nucleolar organizer region-banding. Six of the species exhibited the standard family karyotype, with 2n = 54 M-SM and fundamental number of chromosomes (FN) = 108, as well as variations in the chromosome formula, and in heterochromatic and nucleolar organizer regions. Though nucleolar organizer regions were located on only one chromosome pair, they varied in both carrier chromosomes and pairs involved. On the other hand, C. platanus showed a complement of 2n = 58 M-SM and subtelocentric with FN = 116, and P. squamoralevis presented 2n = 102, with some M-SM and a large number of acrocentric chromosomes. Even though the karyotype macrostructure appears to be conserved, the speciation process within the family has been accompanied by micro-structural rearrangements, as evidenced by pattern diversity in the heterochromatin and nucleolar organizer regions. Some changes in chromosome macrostructure have also occurred in this group, primarily in C. platanus and P. squamoralevis, in which there have been centric dissociations and inversions. PMID:15266401

  13. Application of the comet assay in erythrocytes of Oreochromis niloticus (Pisces): A methodological comparison

    PubMed Central

    2009-01-01

    The present study applied the comet assay to erythrocytes of Oreochromis niloticus with the aim of improving protocols to detect DNA damage in these cells, by using two distinct pHs (pH = 12.1 and pH > 13) and evaluating whether there is a correspondence between silver and ethidium bromide staining. Comets were visually examined and, the frequency of cells with and without damage was obtained, as well as the distribution of classes and scores. By using the Kruskal-Wallis test, our results revealed that pH 12.1 is more effective, although both pHs can be used. Our findings also suggest that silver staining can substitute ethidium bromide, an expensive and highly toxic stain that requires specific equipment for examination. PMID:21637662

  14. Complete mitochondrial genome of the sixblotch hind Cephalopholis sexmaculata (Pisces: Perciformes).

    PubMed

    Hsiao, Sheng-Tai; Chen, Kao-Sung; Tseng, Chen-Te; Wu, Chi-Lun

    2016-01-01

    The complete mitogenome of the sixblotch hind, Cephalopholis sexmaculata was presented in this study. This mitochondrial genome consists of 16,589 bp, with 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and a noncoding control region (CR), and its gene arrangement is identical to most vertebrates. The overall base composition of the heavy strand is A, 29.35%; G, 16.08%; C, 28.56%; and T, 26.01%. The COI gene started with GTG codon and the ATP6 gene started with CTG codon. The complete mitogenomic data may provide informative for further phylogenetic approach of species of Cephalopholis and related genera belong to the Epinephelidae groupers. PMID:24938086

  15. [Citogenetic characterization of the tropical freshwater fish Parachromis managuensis (Pisces: Cichlidae)].

    PubMed

    Arias-Rodríguez, Lenin; Páramo-Delgadillo, Salomón; Durán-González, Alicia de la Luz

    2006-03-01

    To describe the cytogenetics of the jaguar cichlid fish Parachromis managuensis, we collected eight males and 13 females in Villahermosa, Tabasco, México. The specimens were processed with standard cytogenetic techniques (slightly modified), and high quality fields of chromosomes in mitosis and meiosis were obtained; 14 of these fields were analyzed by meristics and statistics methods. The specimens presented a diploid modal number of 2n = 48 chromosomes, which is similar to the number reported for others Central American cichlids; five pairs were submetacentric-metacentrics (biarmed) and 19 were subtelocentric-telocentric (uni-armed), giving a fundamental number (NF) of 58. The haploid number was confirmed by counting meiotic fields in metaphase I. There was not evidence of heteromorphism: sexual chromosomes were not identifiable. PMID:18457172

  16. Wallaceochromis gen. nov, a new chromidotilapiine cichlid genus (Pisces: Perciformes) from West Africa.

    PubMed

    Lamboj, Anton; Trummer, Franziska; Metscher, Brian D

    2016-01-01

    A new genus, Wallaceochromis, is described for the chromidotilapiine cichlids of the Pelvicachromis humilis group. It differs from Pelvicachromis sensu stricto in the number and arrangement of tubular infraorbitals, a straighter and sloping dorsal head profile with a low supraoccipital crest, higher abdominal vertebral counts (14-15 vs. 13-14), and in displaying a pattern of vertical bars on the body in several behavioral situations. PMID:27470842

  17. Spawning Behavior, Egg Development, Larvae and Juvenile Morphology of Hyphessobrycon eques (Pisces: Characidae) Characidae Fishes.

    PubMed

    Park, Jae-Min; Kim, Na-Ri; Han, Kyeong-Ho; Han, Ji-Hyeong; Son, Maeng-Hyun; Cho, Jae-Kwon

    2014-12-01

    Hyphessobrycon eques is a famous fish for ornamental fish market and aquarium. They are inhabit in regions of Amazon and Paraguay River basin. Serpae fishs were investigated 2-3 males are chased to female, and then males attempted to simulate the females abdomen. After fertilization, eggs were kept in incubators at 28°C. The fertilized eggs had adhesive and demesal characteristics and had a mean diameter of 0.92 ± 0.01 mm. Larvae hatched at 16 hrs post fertilization. The hatched larvae averaged 2.90 ± 0.16 mm in total length (LT ). Complete yolk sac resorption and mouth opening occurred on the third day post hatching. At 45 days post hatching, the larvae were 12.5 ± 1.60 mm LT and had reached the juvenile stage. PMID:25949194

  18. A trophic ecology of two grenadier species (Macrouridae, Pisces) in deep waters of the Southwest Atlantic

    NASA Astrophysics Data System (ADS)

    Laptikhovsky, V. V.

    2005-08-01

    The feeding habits of slope-dwelling macrourid fishes from the southern Southwest Atlantic is unknown. In this study the feeding ecology of the two most abundant species, Macrourus carinatus and M. holotrachys, was investigated. Both these grenadiers fed on a variety of prey, including gelatinous plankton, crustaceans, mesopelagic and benthic fish and cephalopods, echinoderms, as well as fishery discards. M. carinatus forage mostly in depths shallower than 900 m and its feeding spectrum and hunting strategy display important seasonal variability. It consumes more pelagic fish, squid and crustaceans than M. holotrachys, which probably indicates occasional feeding in the water column and higher availability of pelagic prey. M. holotrachys forages mostly in depths deeper than 1100 m and is a specialised bottom feeder. Macrourids are able to switch their feeding strategy from browsing on abundant food sources in summer and autumn (a narrow niche breadth and high number of prey per stomach) to hunting occasional prey in winter and spring (a wide niche breadth, low number of prey per stomach). Both species are of similar size and hard to distinguish morphologically, but in deep water M. holotrachys males are smaller than, and females larger than, those of M. carinatus. A probable reason for such energy re-distribution within a population in M. holotrachys is to achieve a higher reproductive output in a food-poor and harsh deep-sea environment.

  19. Slingshot feeding of the goblin shark Mitsukurina owstoni (Pisces: Lamniformes: Mitsukurinidae).

    PubMed

    Nakaya, Kazuhiro; Tomita, Taketeru; Suda, Kenta; Sato, Keiichi; Ogimoto, Keisuke; Chappell, Anthony; Sato, Toshihiko; Takano, Katsuhiko; Yuki, Yoshio

    2016-01-01

    Five striking and prey capture events of two goblin sharks were videotaped at sea for the first time, showing their extraordinary biting process. The goblin sharks swung their lower jaw downward and backward to attain a huge gape and then rapidly protruded the jaws forward a considerable distance. The jaws were projected at a maximum velocity of 3.1 m/s to 8.6-9.4% of the total length of the shark, which is by far the fastest and greatest jaw protrusion among sharks. While the jaws were being retracted, the mouth opened and closed again, which was considered a novel feeding event for sharks. Phylogenetic evidence suggested that their feeding behavior has evolved as an adaptation to food-poor deep-sea environments, possibly as a trade-off for the loss of strong swimming ability. PMID:27282933

  20. Nematode larvae infecting Priacanthus arenatus Cuvier, 1829 (Pisces: Teleostei) in Brazil.

    PubMed

    Kuraiem, Bianca P; Knoff, Marcelo; Felizardo, Nilza N; Gomes, Delir C; Clemente, Sérgio C São

    2016-05-31

    From July to December, 2013, thirty Priacanthus arenatus specimens commercialized in the cities of Niterói and Rio de Janeiro, State of Rio de Janeiro, were acquired. The fish were necropsied and filleted to investigate the presence of nematode larvae. Twenty fish (66.7%) out of the total were parasitized by nematode larvae. A total of 2024 larvae were collected; among them, 30 third-instar larvae of Anisakis sp. showed prevalence (P) = 20%, mean abundance (MA) = 1, and the mean intensity (MI) = 5, and infection sites (IS) = caecum, stomach, liver, and mesentery; and 1,994 third-instar larvae (1,757 encysted and 237 free) of Hysterothylacium deardorffoverstreetorum with P = 66.7%, MA = 66.5, and MI = 99.7, and IS = spleen, caecum, stomach, liver, mesentery, and abdominal muscle. This is the first study to report H. deardorffoverstreetorum and Anisakis sp. larvae parasitizing P. arenatus. PMID:27254444

  1. Biochemistry, physiology, and ecology of bioluminescence in Porichthys notatus (Pisces: batrachoididae)

    SciTech Connect

    Thompson, E.M.

    1987-01-01

    The minute quantities of Vargula luciferin required to establish long-lasting bioluminescence capability in Puget Sound Porichthys has raised questions concerning the mechanism of luminescence induction. To address these question, a small, known quantity of Vargula luciferin was fed to nonluminescent Puget Sound Porichthys and after monitoring the subsequent light output over a two-year period, it was determined that more light was emitted than could be accounted for by the ingested luciferin. Thus, Porichthys is able to turn over luciferin either by recycling or de novo synthesis. To distinguish between these possibilities, /sup 14/C-labeled luciferin was synthesized and fed to nonluminescent Porichthys. Luciferin recovered from the photophores showed no change in specific activity, demonstrating that incorporation of undiluted Vargula luciferin is sufficient to establish bioluminescence capability in the fish, which is then sustained by recycling of luciferin. Porichthys possesses a specialized mechanism for taking up luciferin from the gut-but shows no apparent specific adaptation for transport of luciferin in the blood. Binding of luciferin to erythrocytes and plasma components greatly retarded the rate of luciferin autoxidation, but appeared to be a nonspecific property of fish blood.

  2. Biogeographic patterns in the cartilaginous fauna (Pisces: Elasmobranchii and Holocephali) in the southeast Pacific Ocean

    PubMed Central

    Vargas-Caro, Carolina; Bennett, Michael B.

    2014-01-01

    The abundance and species richness of the cartilaginous fish community of the continental shelf and slope off central Chile is described, based on fishery-independent trawl tows made in 2006 and 2007. A total of 194,705 specimens comprising 20 species (9 sharks, 10 skates, 1 chimaera) were caught at depths of 100–500 m along a 1,000 km transect between 29.5°S and 39°S. Sample site locations were grouped to represent eight geographical zones within this latitudinal range. Species richness fluctuated from 1 to 6 species per zone. There was no significant latitudinal trend for sharks, but skates showed an increased species richness with latitude. Standardised catch per unit effort (CPUE) increased with increasing depth for sharks, but not for skates, but the observed trend for increasing CPUE with latitude was not significant for either sharks or skates. A change in community composition occurred along the depth gradient with the skates, Psammobatis rudis, Zearaja chilensis and Dipturus trachyderma dominating communities between 100 and 300 m, but small-sized, deep-water dogfishes, such as Centroscyllium spp. dominated the catch between 300 and 500 m. Cluster and ordination analysis identified one widespread assemblage, grouping 58% of sites, and three shallow-water assemblages. Assemblages with low diversity (coldspots) coincided with highly productive fishing grounds for demersal crustaceans and bony fishes. The community distribution suggested that the differences between assemblages may be due to compensatory changes in mesopredator species abundance, as a consequence of continuous and unselective species removal. Distribution patterns and the quantitative assessment of sharks, skates and chimaeras presented here complement extant biogeographic knowledge and further the understanding of deep-water ecosystem dynamics in relation to fishing activity in the south-east Pacific Ocean. PMID:24918036

  3. Spawning seasons of Rasbora tawarensis (Pisces: Cyprinidae) in Lake Laut Tawar, Aceh Province, Indonesia

    PubMed Central

    2010-01-01

    Background Rasbora tawarensis is an endemic freshwater fish in Lake Laut Tawar, Aceh Province, Indonesia. Unfortunately, its status is regarded as critical endangered with populations decreasing in recent years. To date no information on the spawning activities of the fish are available. Therefore, this study provides a contribution to the knowledge on reproductive biology of R. tawarensis especially on spawning seasons as well as basic information for conservation of the species. Methods Monthly sampling was conducted from April 2008 to March 2009 by using selective gillnets. The gonadosomatic index, size composition and sex ratio were assessed. The gonadal development was evaluated based on macroscopic and microscopic examinations of the gonads. Results The gonadosomatic index (GSI) varied between 6.65 to 18.16 in female and 4.94 to 8.56 for male. GSI of the female R. tawarensis was higher in March, September and December indicating the onset of reproductive seasons, the GSI and oocyte size being directly correlated with gonadal development stages. Although, a greater proportion of mature male than female was detected during the study, the sex ratio showed that the overall number of female was higher than male. The ovaries had multiple oocyte size classes at every stage of gonadal development, thus R. tawarensis can be classified as a group synchronous spawner or a fractional multiple spawner. Conclusion The spawning seasons of R. tawarensis were three times a year and September being the peak of the reproductive season and the female was the predominant sex. This species is classified as a group synchronous spawner. PMID:20482777

  4. Blood cell lineage in the sea lamprey, Petromyzon marinus (Pisces: Petromyzontidae)

    USGS Publications Warehouse

    Piavis, George W.; Hiatt, James L.

    1971-01-01

    Blood cell types of the sea lamprey, Petromyzon marinus, are described and identified and the lineage of mature circulating cells in peripheral blood is traced to blast cells in the hematopoietic fat body. The fat body appears to be the phylogenetic precursor of bone marrow in higher forms, since blood cells originate and begin maturation in this tissue. Experimental animals were injected first with a hematopoietic stimulant and then (at an experimentally determined time) with pertussis vaccine to release proliferated blood cells into peripheral blood. Peripheral blood for smears was collected by cardiac exsanguination; hematopoietic tissue was extirpated for imprints; and leucocyte preparations were made by a special technique. Blood cells of the sea lamprey are apparently products of at least four distinct blast cells, each of which has a 'one end' maturation process. Results of this investigation support the polyphyletic theory of blood cell formation.

  5. Identification of Bacterial Specialists in Hosts belonging to Aves, Mammalia, and Pisces

    EPA Science Inventory

    Only a portion of bacteria found in animal guts are able to establish specific associations within animal hosts. Taxa that have formed these specialized relationships may have played a prominent role in host evolution and may also contribute significantly to current host physiolo...

  6. INFLUENCE OF ENVIRONMENTAL TEMPERATURE ON SEX-RATIOS IN THE TIDEWATER SILVERSIDE, 'MENIDIA PENINSULAE' (PISCES: ATHERINIDAE)

    EPA Science Inventory

    The sex-ratios of Menidia peninsulae from Santa Rosa Island, Florida were studied during a 13 month survey. Weekly samples revealed significant deviations from the expected sex-ratio of 1:1. During May-October, young-of-the-year (YOY) females comprised 70 to 94% of the individual...

  7. REPRODUCTIVE ECOLOGY OF THE TIDEWATER SILVERSIDE, 'MENIDIA PENINSULAE' (PISCES: ATHERINIDAE) FROM SANTA ROSA ISLAND, FLORIDA

    EPA Science Inventory

    The reproductive ecology of the tidewater silverside, Menidia peninsulae, was studied during February 1982 through February 1983 along the shoreline of Santa Rosa Island, Florida. Adult Menidia were observed at low tide spawning on a red alga, Ceramium byssoideum, which was growi...

  8. Methods for design and evaluation of integrated hardware-software systems for concurrent computation

    NASA Technical Reports Server (NTRS)

    Pratt, T. W.

    1985-01-01

    Research activities and publications are briefly summarized. The major tasks reviewed are: (1) VAX implementation of the PISCES parallel programming environment; (2) Apollo workstation network implementation of the PISCES environment; (3) FLEX implementation of the PISCES environment; (4) sparse matrix iterative solver in PSICES Fortran; (5) image processing application of PISCES; and (6) a formal model of concurrent computation being developed.

  9. [Trophic and reproductive ecology of Trichomycterus calietes and Astrtoblepus cyclopus (pisces: Siluriformes) in Quindio River, Upper Cauca, Colombia].

    PubMed

    Román-Valencia, C

    2001-06-01

    The trophic and reproductive ecology of catfish (Trichomycterus caliense and Astroblepus cyclopus) was studied in the Quindio River upper Basin, Alto Cauca, Colombia. The pH was neutral, water oxygen content high (8.4 ppm) and temperature in the habitats was 18.63 degrees C; both species are nonmigratory and sympatric with four other fish species. The ovaries mature primarily between May and September in T. caliense; between December and May in A. cyclopus. The mean size at maturity is 8.3 cm (standard length) in T. caliense and 6.0 cm (standard length) in A. cyclopus; the sex ratio is 1:1 in T. caliense (X2 = 3.4, P > or = 0.05) and in A. cyclopus (X2 = 1.44, P > or = 0.1); the fecundity is low (191 and 113 oocytes respectively) and the eggs are small (1.5 and 2.39 mm respectively). The fishes are insectivorous and specialize in Coleoptera, Diptera and Trichoptera; Spearman Rank Correlation Coefficients (rs = 0.464) indicated that there are differences (T = 2.5148, P < 0.01) between their diets; both taxa did not agree with the expected trophic habits for sympatric species that are morphologically similar and related in the same trophic level. PMID:11935917

  10. Egg Development and Early Life History of Korean Endemic Species Korean Spotted Sleeper, Odontobutis interrupta (Pisces: Odontobutidae).

    PubMed

    Park, Jae-Min; Han, Kyeong-Ho; Kim, Na-Ri; Yoo, Dong-Jae; Yun, Seong-Min; Han, Ji-Hyeong

    2014-12-01

    The egg development and early life history of Korean spotted sleeper, Odontobutis interrupta which is Korean endemic species from Sora-choen was investigated. The Korean spotted sleeper were caught at Sora-myeon, Yeosu-si, Jeollanamdo, from Korea at May in 2014. The fertilized eggs were 4.23 ± 0.05 mm in long diameter and had oil globules. Hatching time of the embryo began about 442 hr 14 min after fertilization under water temperature of 19.5°C. The newly hatched larvae were 4.27 ± 0.35 mm in total length and their anus were not yet opened. 3 days after hatching postlarvae was measured 6.20 ± 0.11 mm in total length. 10 days after hatching postlarvae was measured 6.69 ± 0.14 mm in total length. PMID:25949196

  11. Morphological characteristics of otoliths for Dussumieria acuta and Dussumieria elopsoides (Pisces: Clupeidae) from the Northern Oman Sea.

    PubMed

    Homayuni, Hanie; Marjani, Mohsen; Mousavi-Sabet, Hamed

    2013-06-01

    Otolith shape were investigated to identify two species of genus Dussumieria inhabiting the northern Oman Sea, south of Iran. The main aim of the investigation was to analyze otolith shape differences between these species. The sagittal otoliths of the rainbow sardine Dussumieria acuta Valenciennes, 1847, and the slender rainbow sardine Dussumieria elopsoides Bleeker, 1849, belonging to different length groups were described. The results showed two groups of special characteristics of the sagittal otoliths in D. acuta, and D. elopsoides. The first group is the characteristics that are useful to separate these species from other clupeid species, however these characteristics are closely related to one another in these species of Dussumieria genus. The second group comprises characteristics that vary due to genetically guided mechanisms and biological factors, but that may be useful to define species and are species-specific. PMID:23721471

  12. Galaxitaenia toloi n. gen., n. sp. (Eucestoda: Pseudophyllidea) from Galaxias platei (Pisces: Osmeriformes, Galaxiidae), in the Patagonian region of Argentina.

    PubMed

    Gil de Pertierra, Alicia A; Semenas, Liliana G

    2005-08-01

    Galaxitaenia n. gen. (Eucestoda: Pseudophyllidea) is proposed to accommodate Galaxitaenia toloi n. gen., n. sp. from Galaxias platei, a freshwater fish inhabiting Andean lakes in Argentine Patagonia. Galaxitaenia belongs to the Triaenophoridae because it possesses a marginal genital pore, a ventral uterine pore, and a follicular vitelline gland. The new genus can be distinguished from other triaenophorids by the following combination of characters: a scolex with a prominent rectangular apical disc without hooks, grooves, or indentations; neck present; segments wider than long to quadrangular; testes in 2 lateral fields, often connected anteriorly; cirrus unarmed; an ovary situated posteriorly; a vagina posterior to the cirrus sac; vitelline follicles medullary, in 2 ventral fields forming 2 wings interrupted medially; a uterus saccate to branched; and eggs without operculum. The types, distribution, and density of microtriches were analyzed on the surface of the tegument of scolex, neck, and immature segments. The presence of tumuli were observed on the apical disc of the scolex. Galaxitaenia toloi n. sp. is the first triaenophorid species recorded in a South American freshwater fish and the fourth helminth parasitizing the intestine of G. platei. PMID:17089762

  13. Parasitic community of Fransciscodoras marmoratus (Reinhardt, 1874) (Pisces: Siluriformes, Doradidae) from the upper São Francisco River, Brazil.

    PubMed

    Santos, M D; Brasil-Sato, M C

    2006-08-01

    One hundred and thirteen specimens of Franciscodoras marmoratus (Reinhardt, 1874) were collected in the upper São Francisco River (18 degrees 12' 32" S, 45 degrees 15' 41" W, state of Minas Gerais) between September, 1999 and January, 2004 to investigate their parasite fauna. From this total, 45 (39.8%) were afflicted by at least one parasite species. The parasitic richness consisted of six species represented by Hirudinea (n = 20), Monogenoidea (n = 25), Eucestoda (n = 55), Nematoda (n = 1, n = 2) and Acanthocephala (n = 41) found in the dry and wet periods making a total of 144 specimens. Proteocephalus renaudi Chambrier & Vaucher, 1994 was the only species with prevalence higher than 10% and a typical aggregate distribution pattern. The prevalence, intensity and abundance of P. renaudi were not influenced by the total length or sex of the hosts or by the collection periods. The relative condition factor indicated that the health of the P. renaudi hosts was not significantly affected in relation to fish not infected by parasites. The fish stocked in tanks before necropsy were opportunistically infested by Lernaea cyprinacea Yashuv, 1959. The various parasites found indicate that F. marmoratus is omnivorous and a potential definitive host. The parasite species, except for Acanthocephala, have expanded their known geographic distribution to the São Francisco River Basin. The parasite community was considered isolationist because of the low endoparasite diversity, infrapopulations with low intensity, lack of evidence of parasite interactions and sparse signs of parasite aggression against their hosts. PMID:17119841

  14. Egg Development of the Ussurian Bullhead Fish, Leiocassis ussuriensis (Pisces: Bagridae) and Morphological Development of Its Larvae and Juveniles

    PubMed Central

    Park, Jae-Min; Yim, Hu-Sun; Lee, Yong-Sik; Kim, Heung-Yun; Han, Kyeong-Ho

    2015-01-01

    This study was examined the ovogenesis of Ussurian bullhead, Leiocassis ussuriensis and the morphological development of its larvae and juveniles and to use the results as basic information for the preservation of species and resource enhancement. For artificial egg collection, human chorionic gonadotropin (HCG) was injected at a rate of 10 IU per gram of fish weight. During breeding period, water temperature maintained at 24.5~26.5°C (mean 25.0±0.05°C). The process of ovogenesis reached the two-cell stage in 50 minutes after fertilization. In 73 hours of fertilization the movement of the embryoid body became active state and the larvae began to hatch from the tail through the oolemma. Length of prelarvae were 6.33~6.50 mm long (mean 6.40±0.06 mm) just after hatching having yolk with their mouth not opened. After thirty eight days of hatching, juveniles were 30.6∼32.5 mm long (mean 31.5±0.65 mm). The color was dark yellowish brown throughout the entire body, and the number of caudal fin rays developed to thirty six perfectly. PMID:26973970

  15. Helminth parasites of the oceanic horse mackerel Trachurus picturatus Bowdich 1825 (Pisces: Carangidae) from Madeira Island, Atlantic Ocean, Portugal.

    PubMed

    Costa, G; Melo-Moreira, E; Pinheiro de Carvalho, M A A

    2012-09-01

    The helminth parasite fauna of the oceanic horse mackerel Trachurus picturatus Bowdich 1825, caught off the Madeira Islands was composed of six different taxa. Prevalence and abundance of larval Anisakis sp. (Nematoda: Anisakidae) and Nybelinia lingualis (Trypanorhyncha: Tentaculariidae), the most common parasite taxa, were 24.3%, 0.9 and 37.9%, 0.7, respectively. Bolbosoma vasculosum (Acanthocephala: Polymorphidae) and the monogeneans Heteraxinoides atlanticus (Monogenea: Heteraxinidae) and Pseudaxine trachuri (Monogenea: Gastrocotylidae) were comparatively rare. The depauperate helminth fauna of the oceanic horse mackerel at Madeira compared to other geographical regions of the north-eastern Atlantic, namely the Azores banks and the West African coast, may be attributed to the paucity of nutrients off oceanic islands and to a low density of the fish population. PMID:21875447

  16. Growth of the Pacific jack Caranx caninus (Pisces: Carangidae) from the coast of Colima, México.

    PubMed

    Barr, Elaine Espino; Cabello, Manuel Gallardo; Solis, Esther Guadalupe Cabral; Boa, Arturo Garcia; Gómez, Marcos Puente

    2008-03-01

    The Pacific jack Caranx caninus is a common species fished by artisanal fishermen off the coast of Colima, México. During 2002, monthly samples of morphometric data and otoliths were taken to determine age and growth. Seven age groups were identified. The highest growth, 14.4 cm, takes place during the first year of life. During the second year, C caninus grows 11.76 cm; the third year 9.61 cm; the fourth 7.85 cm; the fifth 6.41 cm and sixth year 5.24 cm. The constants of von Bertalanffy's growth equation were: L(infinity) = 83.26 cm, W(infinity) = 18.138 g, K = 0.202, t(0) = -0.283 and A(0.95) = 15 years. Growth curves of other species of the same genus were calculated in order to compare them with the one obtained in the present work. The gonadosomatic index presented higher values during November and May. The periods of more intensive feeding are from August to February. PMID:18624235

  17. Epinephelus geoffroyi (Klunzinger, 1870) (Pisces: Serranidae), a valid species of grouper endemic to the Red Sea and Gulf of Aden.

    PubMed

    Randall, John E; Bogorodsky, Sergey V; Krupp, Friedhelm; Rose, Jean Michel; Fricke, Ronald

    2013-01-01

    The grouper Epinephelus geoffioyi (Klunzinger), type locality Red Sea, previously regarded as a synonym of E. chlorostigma (Valenciennes) is recognized as a valid species. It is differentiated from E. chlorostigma by having 25-29 (modally 27) gill rakers vs. 23-26 (modally 24), a more angular anal fin, the dark spots on the abdomen more widely separated, and lacking a clear white margin posteriorly on the caudal fin. The missing holotype of E. geoffroyi was found at the Staatliches Museum für Naturkunde Stuttgart (SMNS 233, 191 mm). Epinephelits chlorostigma is wide-ranging from the Gulf of Aden and east coast of Africa to Samoa; it is reported from the depth range of 32-280 m. Epinephelus geoffroyi is presently known only from the Red Sea and Gulf of Aden at depths of 3-32 m. Illustrations are provided for three other species of groupers with numerous small dark spots, E. areolatus (Forsskål), E. gabriellae Randall & Heemstra, and E. polylepis Randall & Heemstra, that are, or might be, sympatric with E. geoffroyi. PMID:26287104

  18. Integrative taxonomy of Anisakidae and Raphidascarididae (Nematoda) in Paralichthys patagonicus and Xystreurys rasile (Pisces: Teleostei) from Brazil.

    PubMed

    Fonseca, Michelle Cristie Gonçalves da; Knoff, Marcelo; Felizardo, Nilza Nunes; Di Azevedo, Maria Isabel N; Torres, Eduardo José Lopes; Gomes, Delir Corrêa; Iñiguez, Alena Mayo; São Clemente, Sérgio Carmona de

    2016-10-17

    Thirty-six Paralichthys patagonicus and 30 Xystreurys rasile were collected in the state of Rio de Janeiro, Brazil to investigate the presence of anisakid and raphidascaridid nematodes. Anisakis typica, Terranova sp., Contracaecum sp., Hysterothylacium deardorffoverstreetorum, and Raphidascaris sp. were identified using integrative taxonomy of morphological and genetic data. Morphological and morphometric analysis was conducted using bright field microscopy with scanning electron microscopy for topographic characterization of the cuticular surface. Phylogenetic analysis, using ITS and cox2 molecular targets, clearly demonstrated the species identification of A. typica and H. deardorffoverstreetorum and the high diversity of H. deardorffoverstreetorum. This is the first report of A. typica, H. deardorffoverstreetorum, and Raphidascaris sp. parasitizing P. patagonicus and X. rasile. PMID:27491056

  19. Morphological biomarkers in Prochilodus lineatus (pisces, prochilodontidae) for environmental impact assessment in the region of the Baixada Maranhense, Brazil

    NASA Astrophysics Data System (ADS)

    Dantas, Janaína Gomes; Andrade, Ticianne de Sousa de Oliveira Mota; Sodré, Camilla Fernanda Lima; Castro, Jonatas da Silva; Carvalho-Neta, Raimunda Nonata Fortes; Junior, Audálio Rebelo Torres

    2015-12-01

    This study aimed to identify the types of histopathological lesions found in gills of Prochilodus lineatus of the Environmental Protection Area of the Baixada Maranhense region (Brazil). Fish were collected in Mearim river. Sampling took place in October, November and December 2014. We have purchased 30 samples of fish from local fishermen. In the laboratory fish gills were removed, and then fixed in 10% formalin solution and kept into alcohol 70% to the usual histological processing. The tissue was performed by light microscopy and findings were photomicrographed in light microscope - ZEIS. The following lesions were identified: epithelial displacement, the marginal channel shift a start vascular congestion, hyperplasia and merging multiple slides; epithelial disruption, edema, vascular congestion, total fusion of lamellae and disorganization of secondary lamellae. These changes express a response of the body to some xenobiontes. Morphological changes in the gills may represent adaptive strategies for conservation of some biological functions when animals are facing changes in the water quality.

  20. Micronucleus frequency and hematologic index in Colossoma macropomum (Pisces, Ariidae) for environmental impact assessment at a protected area in Brazil

    NASA Astrophysics Data System (ADS)

    Sousa, Debora Batista Pinheiro; Neta, Raimunda Nonata Fortes Carvalho

    2014-10-01

    This study used micronucleus assays and erythrocyte indices in the freshwater fish tambaqui, Colossoma macropomum, to assess environmental impacts in the Environmental Protection Area at Maracanã, São Luis, Brazil. Fish were sampled from two locations within the protected area, Serena Lagoon and Ambude River, on four occasions. Biometric data (length and weight) and an aliquot of blood were collected from each fish for analysis. Erythrocyte indices including: mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration were calculated, and blood samples were examined for micronuclei and nuclear morphological changes. Micronuclei were found in fish from both locations, although the frequency was higher in fish from Ambude River. Nuclear morphological changes were identified only in fish collected from Ambude River. Several nuclear morphological changes were found in erythrocytes stained with Giemsa, including: micronuclei and binucleate nuclei. On average, erythrocyte indices were lower in fish collected from Ambude River than in those from Serena Lagoon. Our results indicate that micronuclei and erythrocyte indices can be used in C. macropomum as indicators of environmental health.

  1. Redescription and genetic characterization of Cucullanus dodsworthi (Nematoda: Cucullanidae) from the checkered puffer Sphoeroides testudineus (Pisces: Tetraodontiformes).

    PubMed

    Mejía-Madrid, Hugo H; Aguirre-Macedo, María Leopoldina

    2011-08-01

    Cucullanus dodsworthi Barreto, 1922 was originally described from the checkered puffer fish, Sphoeroides testudineus (Linnaeus), from Brazilian waters. New material of this nematode species was recovered from the same type host species from Mexican waters off the Yucatán Peninsula. This material was compared with Brazilian specimens. Although Mexican material closely resembles the original description of C. dodsworthi in general appearance, previously undescribed characters, as observed by light and scanning electron microscopy, are described for the first time in this species from both Brazilian and Mexican specimens. These characters include lateral body alae or conspicuous lateral fields that begin in the cervical region and end anterior to first pair of adcloacal papillae in males and at the anus level in females, cephalic and caudal alae absent; presence of pseudobuccal capsule with simple buccal frame well sclerotized with dorsal arrow structures, lateral structures, and lateral reniform structures; deirids, excretory pore, and postdeirids; slight anal protuberance in both sexes, unpaired precloacal papilla in males, phasmids near pair 10 in males and near tail tip in females; female with protruding vulvar lips and smooth eggs. In the absence of better descriptions of this genus, it can be concluded that C. dodsworthi is the only species of marine Cucullanus from the Americas that possesses lateral body alae. Molecular characterization of C. dodsworthi with SSU (18S) and ITS2 rDNA genes is included. A preliminary genetic comparison between SSU rDNA of C. dodsworthi , Truttaedacnitis truttae (Fabricius, 1794), and Dichelyne mexicanus Caspeta-Mandujano, Moravec and Salgado-Maldonado, 1999 places C. dodsworthi as a putative sister taxon to T. truttae . The finding of C. dodsworthi in Mexican marine waters also represents a new geographical record. PMID:21506838

  2. Molecular phylogeny of the families Pleuronectidae and Poecilopsettidae (PISCES, Pleuronectiformes) from Korea, with a Proposal for a new classification

    NASA Astrophysics Data System (ADS)

    Ji, Hwan-Sung; Kim, Jin-Koo; Kim, Byung-Jik

    2016-03-01

    A new classification of the Korean pleuronectids was proposed based on a molecular phylogeny using specimens collected from Korea (including some Japanese specimens) between 2008 and 2013. A molecular phylogeny based on partial sequences of the two mitochondrial DNA regions (COI and 16S rRNA) supported the reciprocal monophyly of the three genera, Cleisthenes, Pleuronectes and Pseudopleuronectes. We also found that the genus Poecilopsetta is clearly distinct from Pleuronectidae at the family level. Therefore, the previous classification of the Korean pleuronectids should be changed as follows; two families (Pleuronectidae and Poecilopsettidae), 18 genera, and 26 species. Further research is required to resolve the taxonomic uncertainty of the five species in the genus Limanda, which clustered into two clades in our analysis.

  3. Pressure and pain In Systemic sclerosis/Scleroderma - an evaluation of a simple intervention (PISCES): randomised controlled trial protocol

    PubMed Central

    2012-01-01

    Background Foot problems associated with Systemic Sclerosis (SSc)/Scleroderma have been reported to be both common and disabling. There are only limited data describing specifically, the mechanical changes occurring in the foot in SSc. A pilot project conducted in preparation for this trial confirmed the previous reports of foot related impairment and reduced foot function in people with SSc and demonstrated a link to mechanical etiologies. To-date there have been no formal studies of interventions directed at the foot problems experienced by people with Systemic Sclerosis. The primary aim of this trial is to evaluate whether foot pain and foot-related health status in people with Systemic Sclerosis can be improved through the provision of a simple pressure-relieving insole. Methods The proposed trial is a pragmatic, multicenter, randomised controlled clinical trial following a completed pilot study. In four participating centres, 140 consenting patients with SSc and plantar foot pain will be randomised to receive either a commercially available pressure relieving and thermally insulating insole, or a sham insole with no cushioning or thermal properties. The primary end point is a reduction in pain measured using the Foot Function Index Pain subscale, 12 weeks after the start of intervention. Participants will complete the primary outcome measure (Foot Function Index pain sub-scale) prior to randomisation and at 12 weeks post randomisation. Secondary outcomes include participant reported pain and disability as derived from the Manchester Foot Pain and Disability Questionnaire and plantar pressures with and without the insoles in situ. Discussion This trial protocol proposes a rigorous and potentially significant evaluation of a simple and readily provided therapeutic approach which, if effective, could be of a great benefit for this group of patients. Trial registration number ISRCTN: ISRCTN02824122 PMID:22309847

  4. Seasonal patterns in metazoan parasite community of the "Fat Sleeper" Dormitator latifrons (Pisces: Eleotridae) from Tres Palos Lagoon, Guerrero, Mexico.

    PubMed

    Violante-González, Juan; Rojas-Herrera, Agustín; Aguirre-Macedo, Ma Leopoldina

    2008-09-01

    Dormitator is among the most important fish genera in the Mexican Pacific coastal lagoon systems. In Tres Palos Lagoon, the Fat Sleeper Dormitator latifrons is one of the most significant species based on catch volume, although it is only consumed locally. Very little information exists on this species' parasitofauna. Composition and temporal variation in the metazoan parasite community structure of Dormitator latifrons from Tres Palos Lagoon (99 degrees 47' W, 16 degrees 48' N), Guerrero, Mexico, were determined using seasonal samples taken between April 2000 and June 2002. Ten parasite species (55 817 individuals) were recovered from 219 examined hosts. These species included eight helminths (Ascocotyle (Phagicola) longa, Echinochasmus leopoldinae, Clinostomum complanatum, Pseudoacanthostomum panamense, Saccocoelioides lamothei, Parvitaenia cochlearii, Contracaecum sp. and Neoechinorhynchus golvani) and two crustaceans (Argulus sp. and Ergasilus sp.). Five of the helminth species exhibited seasonal variation in their infection dynamics associated with environmental changes during the dry and rainy seasons. The variations in the infection dynamics generated changes in the community structure over time. PMID:19419054

  5. Reproduction, growth and vertical distribution of the meso- and bathypelagic fish Cyclothone atraria (Pisces: Gonostomatidae) in Sagami Bay, Central Japan

    NASA Astrophysics Data System (ADS)

    Miya, Masaki; Nemoto, Takahisa

    1987-09-01

    The life history and vertical distribution of the meso- and bathypelagic fish Cyclothone atraria (family Gonostomatidae) are described on the basis of about 9800 specimens taken during a series of 20 cruises from December 1982 to November 1985 at a station near the center of Sagami Bay, Central Japan. C. atraria does not undertake overall diel vertical migrations, being concentrated in the lower mesopelagic and bathypelagic zones below 400 m, with peak abundance at about 600 m both day and night. Spawning occurs mainly during the summer and early autumn. C. atraria releases about 500-3000 eggs at once and may spawn several times during its life span. Duration of the egg and larval stages is estimated to be about 6-7 months. C. atraria is protandrous, attaining male maturation in 3 years at about 25 mm standard length (SL) and attaining female maturation in 5-6 years at about 40 mm SL. Length-frequency analysis demonstrated that modal progressions could be followed until about 55 mm SL; however, no length mode that increases with time was observed at 30-35 mm SL, which corresponds to the size of sex reversal. Such modal indistinctness results from rapid growth of individual fishes set free from male breeding activity during protracted spawning season.

  6. Development of the islets, exocrine pancreas, and related ducts in the Nile tilapia, Oreochromis niloticus (Pisces: Cichlidae).

    PubMed

    Morrison, Carol M; Pohajdak, Bill; Tam, Janet; Wright, James R

    2004-09-01

    Pancreatic development and the relationship of the islets with the pancreatic, hepatic, and bile ducts were studied in the Nile tilapia, Oreochromis niloticus, from hatching to the onset of maturity at 7 months. The number of islets formed during development was counted, using either serial sections or dithizone staining of isolated islets. There was a general increase in islet number with both age and size. Tilapia housed in individual tanks grew more quickly and had more islets than siblings of the same age left in crowded conditions. The pancreas is a compact organ in early development, and at 1 day posthatch (dph) a single principal islet, positive for all hormones tested (insulin, SST-14, SST-28, glucagon, and PYY), is partially surrounded by exocrine pancreas. However, the exocrine pancreas becomes more disseminated in older fish, following blood vessels along the mesenteries and entering the liver to form a hepatopancreas. The epithelium of the pancreatic duct system from the intercalated ducts to the main duct entering the duodenum was positive for glucagon and SST-14 in 8 and 16 dph tilapia. Individual insulin-immunopositive cells were found in one specimen. At this early stage in development, therefore, the pancreatic duct epithelial cells appear to be pluripotent and may give rise to the small islets found near the pancreatic ducts in 16-37 dph tilapia. Glucagon, SST-14, and some PPY-positive enteroendocrine cells were present in the intestine of the 8 dph larva and in the first part of the intestine of the 16 dph juvenile. Glucagon and SST-14-positive inclusions were found in the apical cytoplasm of the mid-gut epithelium of the 16 dph tilapia. These hormones may have been absorbed from the gut lumen, since they are produced in both the pancreatic ducts and the enteroendocrine cells. At least three hepatic ducts join the cystic duct to form the bile duct, which runs alongside the pancreatic duct to the duodenum. PMID:15281064

  7. Development of the embryo, larva and early juvenile of Nile tilapia Oreochromis niloticus (Pisces: Cichlidae). Developmental staging system.

    PubMed

    Fujimura, Koji; Okada, Norihiro

    2007-05-01

    We described the developmental stages for the embryonic, larval and early juvenile periods of Nile tilapia Oreochromis niloticus to elucidate sequential events of craniofacial development. Craniofacial development of cichlids, especially differentiation and morphogenesis of the pharyngeal skeleton, progresses until about 30 days postfertilization (dpf). Because there is no comprehensive report describing the sequential processes of craniofacial development up to 30 dpf, we newly defined 32 stages using a numbered staging system. For embryonic development, we defined 18 stages (stages 1-18), which were grouped into seven periods named the zygote, cleavage, blastula, gastrula, segmentation, pharyngula and hatching periods. For larval development, we defined seven stages (stages 19-25), which were grouped into two periods, early larval and late larval. For juvenile development until 30 dpf, we defined seven stages (stages 26-32) in the early juvenile period. This developmental staging system for Nile tilapia O. niloticus will benefit researchers investigating skeletogenesis throughout tilapia ontogeny and will also facilitate comparative evolutionary developmental biology studies of haplochromine cichlids, which comprise the species flocks of Lakes Malawi and Victoria. PMID:17501907

  8. Gamma ionization of Phagicola longa (Trematoda:Heterophyidae) in Mugilidae (pisces) in São Paulo, Brazil

    NASA Astrophysics Data System (ADS)

    Antunes, S. A.; Wiendl, F. M.; Almeida Dias, E. R.; Arthur, V.; Daniotti, C.

    1993-07-01

    The mullet (Mugilidae) is a fish caught in large quantities in brackish and marine waters of the southern Brazilian coast, which in consequence of its raw consumption as "sashimi", a typical Japanese dish, has led to ten cases of human infection by Phagicola longa in São Paulo, Brazil. The mullet acts as a second intermediate host for the parasite, as in human heterophysiasis in the Near and Far East. In order to control these infections under commercial storage conditions and in raw consumption, the radiolysis of P. longa was studied in three mullet species-the silver mullet ( Mugil curema), the grey mullet ( M. platanus) and the "paratipema" ( Mugil sp.) - subjected to ionization ranging from 1.0 to 10.0 kGy (2.21 kGy/h). It was observed that 1.0 and 2.0 kGy caused a motility decrease in silver mullet parasites from 100% to 15% and 17%, and that doses of 4.0 and 10.0 kGy caused metacercaria inviability. The parasite motility decreased in the grey mullet treated with doses of 2.0, 2.5, 3.0 and 3.5 kGy, from 56% to 31%, 9%, 18% and 5%, respectively, 4.0 kGy tending to be the control dose for P. longa. This dose also controls other metacercaria found in the "parati-pema", without changing the odor, color or appearance of the treated mullet.

  9. Brood discrimination, maturation, and population structure of the hairtail, Trichiurus Haumela (Pisces, Trichiuridae) in northern East China Sea

    NASA Astrophysics Data System (ADS)

    Luo, Bingzheng; Lu, Jiwu; Huang, Songfang

    1984-12-01

    Based upon analysis of the seasonal fluctuation of GSI (gonado-somatic index), the spawning period of the hairtail extends from April to October. The maximum time difference between the early and the late brood individuals is about half a year. It is possible to distinguish the early brood and the late brood on the basis of the diameter of the first ring, setting 1.32 mm as a border line. Therefore, the identification of the first ring was solved in dispute. The maturation stages can be identified on the basis of the macroscopical and microscopical characteristics of the ovary; i.e., immature (II-A, B), maturing (III-C, D, E, IV-F), mature (IV-G, V-H, VI-I) and recovering (VII-J). Maturation is completed in the course of one year from different brood seasons. The smallest size at first maturity in female was about 170 180 mm in length and 80 100 grams in weight. There were two discrete groups in autumn which shown the same population unit in which those individuals may separate temporarily into different groups of biological activities in certain period of their life. Fishing of hairtail has been greatly intensified, the population structure has been subject to a series of change. But the hairtail has relatively strong adaptability, so that its population can maintain a reasonable size despite the heavy fishing.

  10. Genetic diversity and population structure of bocachico Prochilodus magdalenae (Pisces, Prochilodontidae) in the Magdalena River basin and its tributaries, Colombia.

    PubMed

    Berdugo, Gilberto Orozco; Narváez Barandica, Juan C

    2014-03-01

    Prochilodus magdalenae is an endemic freshwater fish that occurs in the Magdalena, Sinú and Atrato hydrographic basins. It has an important economic role and is a food resource for the artisanal fishing communities. Its socioeconomic importance contrasts with the current status of its fisheries, where stocks are being depleted. Considering its importance and lack of information on its genetic structure, we used seven microsatellite markers to assess the genetic structure of wild populations of P. magdalenae. The genetic diversity was assessed and the population genetic structure was estimated through Fst, analysis of molecular variance and Bayesian analysis. A total of 290 alleles were found in all loci throughout all population. The high polymorphism contrasts with the levels of observed heterozygosity (Ho = 0.276), which are the lowest values recorded for the family. We found three populations of bocachico coexisting throughout the studied system, contradicting the hypothesis that freshwater migratory fish form panmictic populations. These results on the genetic structure of P. magdalenae constitute tools for a better understanding of the behavior and biology of this species, contributing to fish management and conservation programs. PMID:24688289

  11. Egg Development and Early Life History of Korean Endemic Species Korean Spotted Sleeper, Odontobutis interrupta (Pisces: Odontobutidae)

    PubMed Central

    Park, Jae-Min; Han, Kyeong-Ho; Kim, Na-ri; Yoo, Dong-Jae; Yun, Seong-Min; Han, Ji-Hyeong

    2014-01-01

    The egg development and early life history of Korean spotted sleeper, Odontobutis interrupta which is Korean endemic species from Sora-choen was investigated. The Korean spotted sleeper were caught at Sora-myeon, Yeosu-si, Jeollanamdo, from Korea at May in 2014. The fertilized eggs were 4.23 ± 0.05 mm in long diameter and had oil globules. Hatching time of the embryo began about 442 hr 14 min after fertilization under water temperature of 19.5°C. The newly hatched larvae were 4.27 ± 0.35 mm in total length and their anus were not yet opened. 3 days after hatching postlarvae was measured 6.20 ± 0.11 mm in total length. 10 days after hatching postlarvae was measured 6.69 ± 0.14 mm in total length. PMID:25949196

  12. Pseudocapillaria yucatanensis sp. n. (Nematoda: Capillariidae) from the bagre Rhamdia guatemalensis (Pisces) from cenotes in Yucatan, Mexico.

    PubMed

    Moravec, F; Scholz, T; Vivas Rodríguez, C

    1995-01-01

    A new nematode species, Pseudocapillaria yucatanensis sp. n., is described from the intestine of the freshwater pimelodid catfish Rhamdia guatemalensis (Günther) from cenotes (= sinkholes) in Yucatan, Mexico. It differs from other three related species parasitizing freshwater fishes mainly in possessing the spicule with a simple rim of its proximal end and a non-expanded distal end, in the length of the spicule (0.218-0.295 mm), and the size (0.050-0.060 x 0.025-0.030 mm), shape and structure of eggs, and also in the host types and geographical distribution. Pseudocapillaria yucatanensis is the first known autochtonous species of Pseudocapillaria parasitizing freshwater fishes in Mexico. PMID:9599428

  13. Redescription of Cheilinus quinquecinctus Rüppell, 1835 (Pisces: Perciformes, Labridae), a valid endemic Red Sea wrasse.

    PubMed

    Bogorodsky, Sergey V; Alpermann, Tilman J; Mal, Ahmad O

    2016-01-01

    The labrid fish Cheilinus quinquecinctus Rüppell, originally described from the Red Sea, has long been regarded as a junior synonym of C. fasciatus (Bloch). Herein, both nominal species are redescribed, based on examination of the types and additional material from the Red Sea (for C. quinquecinctus) and the Indo-West Pacific (for C. fasciatus). Rüppell's description of Cheilinus quinquecinctus was originally based on three syntypes, and the most representative adult specimen is designated as the lectotype. We show that Cheilinus quinquecinctus is restricted to the Red Sea and the Gulf of Aden, and it differs from the similar C. fasciatus in having modally fewer gill rakers on the first gill arch, a total of 13-16 (mean 13.9, usually 13 or 14 ) (vs. 13-16, mean 14.7, usually 14 or 15), in developing a ragged posterior margin of the caudal fin with age (versus only upper and lower caudal-fin lobes developing with age), and in its color pattern. The phylogenetic analysis of the COI barcoding region accords with the species status of C. quinquecinctus with the placement of the two sister species in two divergent and reciprocally monophyletic evolutionary lineages. A full description of C. quinquecinctus and diagnosis of C. fasciatus is provided here for comparison. In addition, the data include a table of the results of the meristic and morphological examination of type and additional specimens of both species from throughout their distribution ranges as well as a table of gill-raker counts of all examined specimens. Underwater color photographs are provided for comparison of juveniles, females and males of both species. PMID:27615897

  14. Embryonic and Morphological Development of Larvae and Juvenile of the Buenos Aires Tetra, Hyphessobrycon anisitsi (Pisces Characidae) Characidae Fishes

    PubMed Central

    Park, Jae-Min; Han, Kyeong-Ho; Han, Ran

    2015-01-01

    We have launched an investigation for Embryonic Development, Larvae and Juvenile Morphology, of Buenos aires tetra in order to build basic data of Characidae and fish seeding production. We brought 50 couples of Characidae from Bizidduck aquarium in Yeosu-si, Jeollanamdo, from Korea on March of 2015. We put them in the tetragonal glass aquarium (50×50×30 cm). Breeding water temperature was 27.5~28.5°C (mean 28.0±0.05°C) and being maintained. The shape of fertilized egg was round shape, and it was adhesive demersal egg. The egg size was 0.63~0.91 mm (mean 0.74±0.07 mm, n=20). After getting fertilized egg, the developmental stage was gastrula stage, and embryo covered almost two-thirds of Yolk. Incubation was happened after 16 hours 13 minutes from gastrula stage, and the tail of juvenile came out first with tearing egg capsule. Immediately after the incubation, prelarvae had 3.78~3.88 mm length (mean 3.84±0.04 mm, n=5), and it had no mouth and anus yet. 34 days after hatching from the incubation, juvenile had 8.63~13.1 mm (mean 10.9±1.66 mm), and it had similar silver-colored body shape with its mother. PMID:25949207

  15. [Reproduction of the spiny puffer, Diodon holocanthus (Pisces: Diodontidae) in the continental shelf of Mexican Central Pacific].

    PubMed

    Lucano-Ramírez, Gabriela; Peña-Pérez, Edith; Ruiz-Ramírez, Salvador; Rojo-Vázquez, Jorge; González-Sansón, Gaspar

    2011-03-01

    Diodon holocanthus is an important economic and ecological species of the demersal fish community, caught as bycatch from local shrimp fishery. The reproductive biology of this long-spine porcupinefish has not yet been described, and reproductive season, the sex ratio, length distribution, length at first gonad maturity, and the gonad macro and microscopic features are described. A total of 400 organisms, ranging from 5.0 to 40.3 cm (average 18.4 cm) total length, were caught from the continental shelf of the Central Mexican Pacific, from December 1995 and December 1998. Sex ratio was 1:0.86 females to males (n = 253). The length at which 50% of the individuals showed maturing gonads was 19.7 cm for females and 20.1 cm for males. Length of the smallest organism with ripe gonads was 12.2 cm for females and 13 cm for males. Four gonadal maturation stages were found in both sexes, and five oocyte development phases were identified. The oocyte development pattern is of asynchronous type, which means the species can reproduce several times a year. Testicle development is lobular type, as in most teleost fishes. Monthly mean values of the gonad-somatic index suggest the reproduction activity peaks in June, and September-December. PMID:21516647

  16. A reappraisal of the evolution of Asian snakehead fishes (Pisces, Channidae) using molecular data from multiple genes and fossil calibration.

    PubMed

    Adamson, Eleanor A S; Hurwood, David A; Mather, Peter B

    2010-08-01

    Freshwater snakehead fishes (Channidae) provide an interesting target for phylogenetic analysis for the following reasons, their unusual biology, potential for cryptic diversity and availability of a good fossil record. Here, a multi-locus molecular phylogeny was constructed and calibrated using two fossil dates to estimate divergence times within the family. Sampling aimed to explore interspecific divergence of Channa species across Southeast Asia and intra-specific variation where species possessed natural geographical ranges that were extensive. Results contradict divergence times estimated previously independently from single locus mitochondrial data or the fossil record and suggest that after divergence from African taxa 40-50 Ma, evolution of Asian snakeheads has been heavily influenced by multiple broad scale dispersal events across India and Southeast Asia. A similar pattern of divergence within multiple clades suggests that west-east dispersal was limited for many taxa during the Miocene. Deep intra-specific divergence was inferred for C. striata, indicating that long historical periods of isolation ( approximately 8Ma) have not resulted in the evolution of reproductive isolation within this species. Results support suggestions that C. marulia like fishes in northern Cambodia may constitute an undescribed species, and that Indian C. diplogramma warrants taxonomic recognition as being distinct from Southeast Asian C. micropeltes, with the two taxa last sharing a common ancestor in the mid- to late-Miocene. PMID:20359539

  17. SPAWNING PERIODICITY OF THE INLAND SILVERSIDE MENIDIA BERYLLINA (PISCES: ATHERINIDAE) IN THE LABORATORY: RELATIONSHIP TO LUNAR CYCLES

    EPA Science Inventory

    The reproductive periodicity of the inland silverside, Menidia beryllina, was determined in laboratory experiments with two independent populations of fish. hese populations were maintained in a non-tidal environment for 85 days and the daily number of eggs produced was enumerate...

  18. Feeding ecology of the Stomiiformes (Pisces) of the northern Mid-Atlantic Ridge. 1. The Sternoptychidae and Phosichthyidae

    NASA Astrophysics Data System (ADS)

    Carmo, Vanda; Sutton, Tracey; Menezes, Gui; Falkenhaug, Tone; Bergstad, Odd Aksel

    2015-01-01

    Comprehensive trophic studies in the vast mid-oceanic regions are rare compared to coastal and fisheries-oriented investigations. Field sampling conducted by the multidisciplinary, international Census of Marine Life project MAR-ECO, namely the 2004 G.O. Sars cruise, has generated one of the largest open ocean deep-pelagic sample collections ever obtained. With the overall goal of understanding carbon flow processes within and through the deep-pelagic nekton associated with the northern Mid-Atlantic Ridge system (N MAR), quantitative trophic analyses were conducted in order to identify the major intraspecific patterns in diet of characteristic members of the midwater fish community. Diets of five abundant species of zooplanktivorous fishes were examined in detail in terms of prey taxonomy and variability in space, ontogeny and diel cycle. Two major patterns of feeding were identified. Pattern 1 included three species preying primarily on copepods, Argyropelecus hemigymnus, Maurolicus muelleri and Vinciguerria attenuata, the former two of which revealed spatial differences in diet with latitude, mostly likely related to latitudinal prey distributions and densities. Maurolicus demonstrated ecological differences in diet that mirrored phenotypic variation North and South of the Subpolar Front, an 'oceanic species concept' question that warrants further research. Pattern 2 included two species feeding primarily on amphipods, Argyropelecus aculeatus and Sternoptyx diaphana, both of which showed ontogenetic variability in feeding primarily related to specific amphipod taxon sizes, rather than prey switching to other major prey taxa. This is the first study that highlights the importance of amphipods in the diets of these species. All fish species showed selectivity in prey choice, possibly related to competition with the other major nekton components along the N MAR, namely the Myctophidae and other zooplanktivorous Stomiiformes. Daily ration fell within the expected values for midwater fishes (1-4% of body weight) with the exception of S. diaphana, suggesting that this species is unique among the zooplanktivores - either its ration is three times higher than the other species, or it eats one-third as often (i.e., every 3 days). Given the high percent stomach fullness observed throughout the diel cycle, we believe the former to be the case, which is the first estimate of its kind for a midwater fish. In order to facilitate further quantitative research on mesopelagic carbon cycling, detailed prey length/weight regressions are presented here.

  19. Micronucleus frequency and hematologic index in Colossoma macropomum (Pisces, Ariidae) for environmental impact assessment at a protected area in Brazil

    SciTech Connect

    Sousa, Debora Batista Pinheiro; Neta, Raimunda Nonata Fortes Carvalho

    2014-10-06

    This study used micronucleus assays and erythrocyte indices in the freshwater fish tambaqui, Colossoma macropomum, to assess environmental impacts in the Environmental Protection Area at Maracanã, São Luis, Brazil. Fish were sampled from two locations within the protected area, Serena Lagoon and Ambude River, on four occasions. Biometric data (length and weight) and an aliquot of blood were collected from each fish for analysis. Erythrocyte indices including: mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration were calculated, and blood samples were examined for micronuclei and nuclear morphological changes. Micronuclei were found in fish from both locations, although the frequency was higher in fish from Ambude River. Nuclear morphological changes were identified only in fish collected from Ambude River. Several nuclear morphological changes were found in erythrocytes stained with Giemsa, including: micronuclei and binucleate nuclei. On average, erythrocyte indices were lower in fish collected from Ambude River than in those from Serena Lagoon. Our results indicate that micronuclei and erythrocyte indices can be used in C. macropomum as indicators of environmental health.

  20. Ultrastructural study of spermiogenesis and the spermatozoon of Microcotyle pancerii (Monogenea: Polyopisthocotylea: Microcotylidae), parasite of meagre Argyrosomus regius (Pisces: Teleostei).

    PubMed

    Quilichini, Yann; Foata, Joséphine; Marchand, Bernard

    2009-04-01

    The present work deals with the ultrastructure of spermiogenesis and the spermatozoon of Microcotyle pancerii, a gill parasite of meagre Argyrosomus regius collected in Corsican fish farms. Spermiogenesis was rather similar to that observed in other polyopisthocotylean Monogenea. The intercentriolar body was different from that described in digeneans. The nuclear condensation occurred in 2 successive stages. First, during the nuclear migration in the median cytoplasmic process, the nucleus developed a honeycomb-like appearance. Then, after the flagellar fusion, a discontinuous twisting of the chromatin appeared along the nucleus, with this process ending in total nuclear condensation. The structure of the spermatozoon is characterized by 2 axonemes (9 + "1" pattern), a single and continuous field of cortical microtubules, a mitochondrion, and a nucleus. Our findings were compared with various ultrastructural features in order to highlight variability within the group. PMID:18817455

  1. The significance of meristic variation in Benthosema glaciale (Pisces, Myctophoidei) and of the species distribution off northwest Africa

    NASA Astrophysics Data System (ADS)

    Badcock, Julian

    1981-12-01

    A comparison of meristics (vertebrae, AO photophores, and gill rakers) between populations of the lanternfish Benthosema glaciale from the eastern North Atlantic north of the Gulf of Cadiz, the Canary Current Upwelling Region, and the Mediterranean reaffirms the distinctions made by TåNING (1918, Report on the Danish Oceanographical Expeditions 1908-1910 to the Mediterranean and adjacent seas, 2, 1-154) between Northern Atlantic and Mediterranean forms and furthermore shows that the Upwelling and Mediterranean populations are indistinguishable on the basis of these characters. Although the current systems through the Straits of Gibraltar are such that the potential for contact between the Northern Atlantic and Mediterranean populations exists, no clinal relationship of meristics between them was found in the area of Mediterranean Outflow. This, and observed changes in interspecific relationships held by the Northern population and also the different relationships held by the Northern and Mediterranean populations point strongly to their genetic separation. Consideration of other species showing distribution patterns analagous to those of B. glaciale populations suggests that whilst gene flow between the Mediterranean and Canary Current Upwelling regions must be strongly maintained, that between the Mediterranean and Northern Atlantic is much weaker. Moreover, the evidence suggests that a subpolar-temperate and temperate mesopelagic fish fauna may exist in a pseudoceanic capacity, extending southwards of the Gulf of Cadiz along the northwest African slpe area in the "Mauritanean Upwelling Region". Within the northern sector of this region these species have their centres of abundance over the slope rather than off it, whereas species of other basic distribution patterns (northern and tropical) have their centres further offshore, at least in late winter and early spring. The onslope fauna breeds and thrives around upwelling conditions, whereas the situation regarding northern species of the offslope fauna may be analagous to that on the western seaboard, where tropical species can be maintained in abundance in temperate climes by the Florida Current-Gulf Stream system. It is suggested that the hydrographic and circulatory characters off northwest Africa would maintain the core abundances of these two faunas as separate entities.

  2. Recovery of plasmatic cholinesterase activity in a neotropical fish Prochilodus lineatus (Pisces, Curimatidae) exposed to organophosphorous pesticides.

    PubMed

    Loteste, Alicia; Cazenave, Jimena; Parma de Croux, M Julieta

    2002-07-01

    The objective was to determine the plasmatic enzyme cholinesterase recovery, after being inhibited by an organophosphorous in juveniles of Prochilodus lineatus. Fish were exposed 12 h to a sublethal concentration of 1 mg/l of monocrotophos, and immediately placing in clean water during 12, 24, 48 and 96 h to detoxification. After this period, blood was extracted and plasma were used for the quantification of cholinesterase. The results showed a enzymatic inhibition of 91.9%, 55.1%, 50.4% and 33.4% with 12, 24, 48 and 96 h of recovery, respectively. The enzymatic activity spreads to be normalized with the course of hours and the degree of inhibition obtained initially was very high and sustained in the first 48 h. PMID:12597563

  3. Gill parasites of Prochilodus lineatus (Valenciennes, 1836) (Pisces; Curimatidae; Prochilodontinae) in the Middle Paraná System (Argentina).

    PubMed

    Chemes, Silvina Beatriz; Gervasoni, Silvia Hebe

    2013-01-01

    We studied gill parasites of Prochilodus lineatus in the San Javier River, which is connected to the Middle Paraná System (Santa Fe, Argentina). In 25 specimens, the parasite prevalence in branchial organs was 92% and the average intensity was 8.3 parasites/infested fish. The parasite community showed no dominance of any taxon, but the family Dactylogyridae represented 60% of the community. We found a significant association between Tereancistrum curimba and Dactylogyridae specimens. The prevalence of the parasites T. toksonum and T. curimba was higher than what has been recorded in the floodplain of the Upper Paraná River, Brazil, demonstrating that the geographic distribution of parasites belonging to Tereancistrum genus is thus expandeing. PMID:24473894

  4. Feeding ecology of Liza ramada (Risso, 1810) (Pisces, Mugilidae) in a south-western estuary of Portugal

    NASA Astrophysics Data System (ADS)

    Almeida, P. R.

    2003-05-01

    The feeding activity of the Liza ramada population inhabiting the Mira estuary (Portugal) is reduced during the winter and summer months. At the beginning of the spawning migration (i.e. November) an increase in the amount of food ingested was noticed. In the upper estuary, the feeding behaviour is independent of the tidal cycle, although there is some evidence of a daily rhythm in the food consumption rate, with a reduction during the night. No significant correlation was found between the quantity of particulate organic matter and the concentration of microalgae present in the stomach contents, and it seems that the bulk of the organic matter ingested by the thin-lipped grey mullets comes from a different origin than planktonic or benthic microalgae. The L. ramada population showed a positive selection for sediment particles between 55 and 250 μm in diameter. In general, the diet composition of this species showed a low diversity of food items. A total of 52 food items were identified in the stomach contents, the Bacillariophyceae being the dominant group. The genera Melosira and Ciclotella were the most common and abundant food items, although the genera Navicula, Nitzschia and Surirella were also classified as preferential food items. It was found that the volume of ploughed sediment that resulted from the feeding activity of the thin-lipped grey mullets, and the correspondent disturbed area increased exponentially with the length of the fish.

  5. Heavy Metals and Histopathological Alterations in Salminus franciscanus (Lima & Britski, 2007) (Pisces: Characiformes) in the Paraopeba River, Minas Gerais, Brazil.

    PubMed

    Savassi, Lourenço Almeida; Arantes, Fabio Pereira; Gomes, Marcos Vinicius Teles; Bazzoli, Nilo

    2016-04-01

    Cu, Pb, Cd, Zn, Cr, Hg, and Fe in the liver, spleen and muscle, of the fish Salminus franciscanus, from two sections of Paraopeba River, highly affected by anthropogenic influences, was detected in levels above those recommended for human consumption. Positive correlations between fish size and levels of metals were detected for Cd, Pb, Hg, and Zn. In the livers, areas with lipid accumulation and pigmented macrophages were also observed, as was fibrosis of the spleen in the parenchymal area through the presence of pigmented macrophages. The diameter of vitellogenic follicles was less and the frequency of atresia was higher in fish from section A. Thus, our study showed that beyond the risk to the population that eats S. franciscanus from the Paraopeba River, we should also consider the risk to the conservation of this species, since histopathological changes were detected in target organs and in some reproductive parameters. PMID:26781631

  6. Food and feeding relationships of three sympatric slickhead species (Pisces: Alepocephalidae) from northeastern Chatham Rise, New Zealand

    NASA Astrophysics Data System (ADS)

    Jones, M. R. L.; Breen, B. B.

    2013-09-01

    The food and feeding relationships of mid-slope slickheads in New Zealand waters are little known compared with those from the northern hemisphere. This study examines the feeding relationships of three common slickhead species from approximately 1000 m on Chatham Rise, New Zealand: Alepocephalus antipodianus (Parrot, 1948), A. australis (Barnard, 1923), and Xenodermichthys copei (Gill, 1884). The Alepocephalus species were predominantly benthopelagic feeders with a small benthic component to their diets. Alepocephalus australis fed on pelagic tunicates, notably Pyrosoma atlanticum Péron, 1804. Alepocephalus antipodianus fed on fish and pelagic tunicates, and also crustaceans. Xenodermichthys copei fed primarily on crustaceans. Considerable material was recovered from the intestines of all three species, and much of it was identifiable and only partially digested, including the remains of pelagic tunicates. There was little dietary overlap between the stomach contents of the three slickhead species indicating a degree of niche partitioning. Intestinal contents differed from stomach contents in weight, but not in number of items for all three species. The composition of stomach and intestinal contents differed for A. australis, but not for A. antipodianus or X. copei, which suggests that intestinal contents could be potentially useful in lieu of stomach content. There was a high level of overlap between the intestinal contents of A. antipodianus and A. australis, suggesting a possible closer dietary relationship between these two species than that indicated by stomach contents alone. Despite limitations in sample size and spatial and temporal coverage, the results from this study indicate that the three slickhead species could play an important role in the structuring of the demersal community at mid-slope depths on northeastern Chatham Rise.

  7. Distribution and biology of five grenadier fish (Pisces: Macrouridae) from the upper and middle slope of the northwestern Mediterranean

    NASA Astrophysics Data System (ADS)

    Massutí, Enric; Morales-Nin, Beatriz; Stefanescu, Constantí

    1995-03-01

    Specimens of five Macrouridae species ( Trachyrhynchus trachyrhynchus, Nezumia aequalis, Hymenocephalus italicus, Coelorhynehus coelorhynchus and Coelorhynchus labiatus) were obtained from 76 bottom trawls in the Catalan Sea at depths between 147 and 1290 m. Abundance, biomass and length distribution by depth varied depending on the species. For T. trachyrhynchus, maximum abundance and biomass were found between 900 and 1000 m. In H. italicus, abundance and biomass decreased below 500-600 m, whereas abundance and biomass showed a bimodal trend for N. aequalis. In these species, the mean length of the specimens increased with depth. The sex-ratio was 50% for intermediate sizes while larger fish were predominantly females. Reproduction patterns were different for each species. Ripe females of N. aequalis and H. italicus were found all year round, while C. coelorhynchus and C. labiatus ripe females were found in spring-summer and autumn winter, respectively. No ripe females of T. trachyrhynchus were found. Size at attainment of 50% maturity for N. aequalis and H. italicus was 4.5 and 2.7 cm pre-anal length (PAL), respectively. The PAL-otolith length (OL) and OL- otolith weight (OW) relationships showed a negative allometry, except for C. labiatus whose OL-OW relationship was isometric. Seasonal growth was detected in the otoliths of all five species; fast growth rings were laid down in summer. All the species reach ages of at least 9 years, and growth rates were relatively high and greater for females.

  8. Morphological aspects of Clinostomidae metacercariae (Trematoda: Digenea) in Hoplerytrinus unitaeniatus and Hoplias malabaricus (Pisces: Erythrinidae) of the Neotropical region, Brazil.

    PubMed

    Benigno, Raimundo N M; Knoff, Marcelo; Matos, Edilson R; Gomes, Delir C; Pinto, Roberto M; Clemente, Sérgio C São

    2014-05-14

    Species of fish of Marajó Island, State of Pará, Brazil, were examined to identify the trematodes parasitizing 102 Hoplerytrinus unitaeniatus (gold wolf fish) and 104 Hoplias malabaricus (thraira). Metacercariae of two species of trematodes, 170 specimens of Clinostomatopsis sorbens and 10 Ithyoclinostomum dimorphum were found and identified. The parasitary indices of C. sorbens from H. unitaeniatus and H. malabaricus, were 43.14% and 30.77% for prevalence, 2.52 and 1.84 for mean intensity, 1.09 and 0.57 for mean abundance and 1 to 9 and 1 to 7 for range of infection, respectively, on both fish the site of infection was the mesentery. The parasitary indices of I. dimorphum from H. unitaeniatus were 2.94% for prevalence, 2.66 for mean intensity, 0.08 for mean abundance, 1 to 4 for range of infection, and the sites of infection were the mesentery and the muscle. Metacercariae of I. dimorphum were collected in muscles of a specimen of H. malabaricus, with 0.96% of prevalence, intensity of infection of 2 parasites and 0.02 of abundance. New morphological data of external and internal structures are presented. This is the first record of metacercariae of C. sorbens and I. dimorphum in Amazonian fish. PMID:24838543

  9. Species composition and distribution of the Antarctic plunderfishes (Pisces, Artedidraconidae) from the Ross Sea off Victoria Land

    NASA Astrophysics Data System (ADS)

    La Mesa, Mario; Cattaneo-Vietti, Riccardo; Vacchi, Marino

    2006-04-01

    Among the notothenioid fish, the Antarctic plunderfishes (family Artedidraconidae) are a poorly known component of the bottom fauna of the continental shelf despite their relative importance. The family is composed of 25 small- to medium-sized endemic species and four genera, Artedidraco, Dolloidraco, Histiodraco and Pogonophryne, which are the most benthic and sedentary of the notothenioid fish. In the framework of "Victoria Land Transect Project", several samples of plunderfishes were collected by means of an Agassiz trawl. Sampling activities were carried out between 100 and 500 m depth in five sites over nearly 4° latitude off Victoria Land. Overall, trawling yielded 80 specimens of plunderfish, including all species of Artedidraco reported from the Ross Sea, i.e. Artedidraco glareobarbatus, A. loennbergi, A. orianae, A. shackletoni and A. skottsbergi, and the monotypic genus Histiodraco. The use of multivariate statistical analyses on catch data indicated sampling site as the main factor affecting species composition. Histiodraco velifer and A. skottsbergi were caught almost exclusively in the southernmost sites, characterizing the artedidraconid fauna of Cape Russell. A. orianae was sampled only in the northernmost sites, such as Cape Adare and Hallett Peninsula. A. loennbergi appeared to be a ubiquitous species, whereas A. glareobarbatus was caught only at the Hallett Peninsula. Plunderfishes showed a particular distribution pattern in relation to depth as well. A. glareobarbatus was the shallowest species, being sampled within 100 m. A. orianae and A. shackletoni showed a similar distribution, being caught mostly at 100-200 m, whereas A. skottsbergi was mainly sampled at 200-300 m. H. velifer was caught in a wide depth range, but mostly in deeper waters (400 m). A. loennbergi was eurybathic, showing a wider depth distribution than other species. Univariate measures of diversity indicated Cape Adare as the poorer site in terms of species richness and diversity. Number of species, diversity and equitability were quite similar off Hallett Peninsula and Cape Russell, indicating the absence of a latitudinal trend. Generally, all univariate indices decreased from shallow (100 m) to deep waters (500 m).

  10. Can the name Mugil cephalus (Pisces: Mugilidae) be used for the species occurring in the north western Atlantic?

    PubMed

    Pacheco-Almanzar, Eloísa; Simons, James; Espinosa-Pérez, Héctor; Chiappa-Carrara, Xavier; Ibáñez, Ana L

    2016-01-01

    Menezes et al. (2010) show that Mugil cephalus Linnaeus, 1758 is different from Mugil liza Valenciennes 1836, the latter being the mullet found along the Atlantic coast of South America. They also suggest that individuals identified as M. cephalus from the northwest Atlantic could represent a population of M. liza in this region, since they doubt the presence of M. cephalus in waters colder than the ones of the West Indies. In order to clarify the presence of M. cephalus in the northwest Atlantic, this study compares meristic and morphometric measurements of M. cephalus and M. liza from the Gulf of Mexico with those obtained by Menezes et al. (2010) for M. liza from South America and for M. cephalus in the Mediterranean Sea. Results show that there are differences in both morphometric and meristic data between the two species. The morphometric measure that differentiates these species is the distance from the snout to the dorsal fin, which is positioned backwards in M. liza compared with M. cephalus. The body width is consistently greater in M. cephalus than M. liza. The meristic character that discriminates between both species is the number of scales in the longitudinal series that, in M. cephalus, ranges from 38 to 43 while in M. liza between 32 to 39. The information presented in this work confirms the presence of M. cephalus in the Gulf of Mexico and the sympatric presence of M. liza is established, even if its abundance is quite low. PMID:27394872

  11. Effect of temperature on microstructures and retention properties in tungsten exposed to D + He + Be mixture plasmas in PISCES

    NASA Astrophysics Data System (ADS)

    Iijima, N.; Miyamoto, M.; Nishijima, D.; Baldwin, M. J.; Doerner, R. P.; Ueda, Y.; Sagara, A.; Höschen, T.

    2015-08-01

    The influence of temperature on microstructures and D retention properties in tungsten exposed to D + He + Be mixture plasmas is investigated. For the low temperature exposure case at 573 K, the Be seeding to D + He mixture plasmas results in the suppression of high density He nano-bubbles, which are distinctive internal defects observed in He irradiated/exposed metals. In contrast, fine and high-density He bubbles appear for W exposed to D + He + Be mixture plasmas at higher temperatures of >773 K. TDS measurements also show that the influence of Be seeding to D + He mixture plasmas, which counteracts the significant reduction in D retention, becomes weak with increasing temperature. From XPS analyses, it is considered that Be2W is formed by interdiffusion and solid-state-reaction at the high temperature exposure case, and the influence of the metallic Be on surface properties gradually disappears with increasing temperature.

  12. Comparative age and growth of common snook Centropomus undecimalis (Pisces: Centropomidae) from coastal and riverine areas in Southern Mexico.

    PubMed

    Perera-Garcia, Martha A; Mendoza-Carranza, Manuel; Contreras-Sánchez, Wilfrido; Ferrara, Allyse; Huerta-Ortiz, Maricela; Hernández-Gómez, Raúl E

    2013-06-01

    Common snook Centropomus unidecimalis is an important commercial and fishery species in Southern Mexico, however the high exploitation rates have resulted in a strong reduction of its abundances. Since, the information about its population structure is scarce, the objective of the present research was to determine and compare the age structure in four important fishery sites. For this, age and growth of common snook were determined from specimens collected monthly, from July 2006 to March 2008, from two coastal (Barra Bosque and Barra San Pedro) and two riverine (San Pedro and Tres Brazos) commercial fishery sites in Tabasco, Mexico. Age was determined using sectioned saggitae otoliths and data analyzed by von Bertalanffy and Levenberg-Marquardt among others. Estimated ages ranged from 2 to 17 years. Monthly patterns of marginal increment formation and the percentage of otoliths with opaque rings on the outer edge demonstrated that a single annulus was formed each year. The von Bertalanffy parameters were calculated for males and females using linear adjustment and the non-linear method of Levenberg-Marquardt. The von Bertalanffy growth equations were FLt = 109.21(1-e-0.2(t+0.57)) for Barra Bosque, FLt = 94.56(1-e-027(t+0.485)) for Barra San Pedro, FLt = 97.15(1-e 0.17(t + 1.32)) for San Pedro and FLt = 83.77(1-e-026(t + 0.49)) for Tres Brazos. According to (Hotelling's T2, p < 0.05) test growth was significantly greater for females than for males. Based on the Chen test, von Bertalanffy growth curves were different among the study sites (RSS, p < 0.05). Based on the observed differences in growth parameters among sampling sites (coastal and riverine environments) future research need to be conducted on migration and population genetics, in order to delineate the stock structure of this population and support management programs. PMID:23885591

  13. Morphological biomarkers in Prochilodus lineatus (pisces, prochilodontidae) for environmental impact assessment in the region of the Baixada Maranhense, Brazil

    SciTech Connect

    Dantas, Janaína Gomes; Andrade, Ticianne de Sousa de Oliveira Mota; Castro, Jonatas da Silva; Sodré, Camilla Fernanda Lima; Carvalho-Neta, Raimunda Nonata Fortes; Junior, Audálio Rebelo Torres

    2015-12-31

    This study aimed to identify the types of histopathological lesions found in gills of Prochilodus lineatus of the Environmental Protection Area of the Baixada Maranhense region (Brazil). Fish were collected in Mearim river. Sampling took place in October, November and December 2014. We have purchased 30 samples of fish from local fishermen. In the laboratory fish gills were removed, and then fixed in 10% formalin solution and kept into alcohol 70% to the usual histological processing. The tissue was performed by light microscopy and findings were photomicrographed in light microscope - ZEIS. The following lesions were identified: epithelial displacement, the marginal channel shift a start vascular congestion, hyperplasia and merging multiple slides; epithelial disruption, edema, vascular congestion, total fusion of lamellae and disorganization of secondary lamellae. These changes express a response of the body to some xenobiontes. Morphological changes in the gills may represent adaptive strategies for conservation of some biological functions when animals are facing changes in the water quality.

  14. Phylogeny of the eelpout genus Lycodes (Pisces, Zoarcidae) as inferred from mitochondrial cytochrome b and 12S rDNA.

    PubMed

    Møller, Peter R; Gravlund, Peter

    2003-03-01

    The bottom-dwelling and species-rich eelpout genus Lycodes Reinhardt has a great potential for the study of Arctic marine speciation. Subdivision of the genus has been based on single or few morphological characters (e.g., lateral line configuration) with contradicting results and phylogenetic approaches have not been attended. Here we present the first phylogenetic analysis of the genus employing DNA sequences of the mitochondrial genes cytochrome b and 12S rDNA (714 bp). The analysis with the two genes combined resulted in two equally parsimonious trees. In both cladograms most of the previously suggested subgroups are para- or polyphyletic, except for the so-called short-tailed Lycodes spp., with a short tail, a single mediolateral lateral line configuration and a shallow or filled otolith sulcus. The group of long-tailed Lycodes spp., with ventral or ventro-medio-lateral types of lateral line configuration and a deep otolith sulcus, appears to be paraphyletic, since Pacific and Atlantic species in this group are not each other's closest relatives. Thus, the short-tailed species are placed in a derived clade, indicating a secondary shortening of the tail, and a "slope to shore" type of evolution. This is not in accordance with earlier assumptions of the more elongate, deeper living species being the more derived. The basal position of long-tailed Pacific species supports earlier theories of Pacific origin of the genus/family. Small genetic differences between Arctic/Atlantic species indicate a rather recent radiation in these areas after the opening of the Bering Strait 3.0-3.5 million years ago. PMID:12644398

  15. A new species of Near-shore Marine Goby (Pisces: Gobiidae: Nesogobius) from Kangaroo Island, Australia.

    PubMed

    Hammer, Michael P; Hoese, Douglass F; Bertozzi, Terry

    2015-01-01

    Nesogobius is one of two goby genera with all species wholly restricted to temperate Australian waters. Described here is a new member of the genus discovered during near-shore marine and estuarine fish sampling along the central southern Australian coastline. The tiger sandgoby Nesogobius tigrinus sp. nov. is distinguished from other congeners by a combination of colouration including four prominent vertical black bars on males; morphological characters involving body scales (large), head scales (naked), body depth (slender) and gill opening (wide); meristic counts including a lack of second dorsal and anal fin spines; and mitochondrial DNA sequence divergence. The species appears to be a narrow range endemic, restricted to specific sub-tidal habitat in the unique sheltered embayments of northeast Kangaroo Island. This study forms part of ongoing investigations to more fully describe the biodiversity and conservation requirements of the regional ichthyofauna. PMID:26701487

  16. Population ecology of the tonguefish Symphurus thermophilus (Pisces; Pleuronectiformes; Cynoglossidae) at sulphur-rich hydrothermal vents on volcanoes of the northern Mariana Arc

    NASA Astrophysics Data System (ADS)

    Tunnicliffe, Verena; Tyler, Jennifer; Dower, John F.

    2013-08-01

    Flatfish are a major component of the hydrothermal vent community on three seamounts of the northern Mariana Volcanic Arc in the northwest Pacific. Nikko, Kasuga-2 and Daikoku seamounts host vent fields between 375 and 480 m depth where high temperature vents release molten sulphur. The small cynoglossid tonguefish, Symphurus thermophilus Munroe and Hashimoto, is ubiquitous in all vent habitats observed on these seamounts: among extensive fields of tubeworms and mussels and on solid sulphur surfaces on Nikko; on sulphur-rich sediments and barnacle-covered boulders on Kasuga-2; and on recent sulphur flows and on broad areas of loose and semi-consolidated sediments on Daikoku. We recorded repeated forays by individuals onto flows of molten sulphur as these surfaces cooled. Based on observations using ROVs, the mean density is 90 fish/m2 with maximum counts over 200 fish/m2 on Daikoku sediments. Compared to collected tonguefish from Daikoku and Kasuga-2, those from Nikko have significantly greater lengths and, on average, six times the mass. Otolith data indicate upper ages of 13 years with Nikko tonguefish growing significantly faster. Diets of tonguefish on the three seamounts reflect the different habitats and prey availability; in Daikoku specimens, small crustaceans and polychaetes are most common while on Nikko, gut contents are predominantly larger shrimp. We made the unusual observation of stunned midwater fish falling to the seafloor near the vents where S. thermophilus immediately attacked them. This tonguefish has a wide diet range and foraging behaviour that likely influence the differing growth rates and sizes of fish inhabiting the different vent sites. Limited genetic data suggest that larval exchange probably occurs among sites where the common habitat factor is high levels of elemental sulphur forming hard and partly unconsolidated substrata. Here, in the northern range of the Mariana Trench Marine National Monument, S. thermophilus, despite having an unusually broad habitat association, may be restricted in its overall range to this region of isolated volcanoes with active hydrothermalism.

  17. Ultrastructural study of vitellogenesis and oogenesis of Metadena depressa (Stossich, 1883) Linton, 1910 (Digenea, Cryptogonimidae), intestinal parasite of Dentex dentex (Pisces, Teleostei).

    PubMed

    Greani, Samuel; Quilichini, Yann; Foata, Joséphine; Swiderski, Zdzisław; Marchand, Bernard

    2012-01-01

    The ultrastructural organization of the female reproductive system of Metadena depressa, digenean intestinal parasite of Sparidae (Dentex dentex), was investigated by electron microscopy. The vitellogenesis is divided into four stages: stage I, vitellocytes have a cytoplasm mainly filled with ribosomes and few mitochondria; stage II, beginning of the synthetic activity; stage III, active shell globule clusters synthesis; stage IV, mature vitellocytes are filled with shell globule clusters and generally contain several large lipid droplets. Glycogen granules are grouped at the periphery of the cell. The three stages of the oogenesis process take place in the ovary: stage I, oogonia are undifferentiated small cells located at the periphery of the organ; stage II, primary oocytes possess a higher nucleo-cytoplasmic ratio and a nucleus with a nucleolus and synaptonemal complexes indicating the zygotene-pachytene stage of the first meiotic division; stage III, mature oocytes are located in the proximal region of the organ and possess a cytoplasmic chromatoid body and cortical granules in a monolayer close to the periphery of the cell. PMID:23199633

  18. Balancing genetic uniqueness and genetic variation in determining conservation and translocation strategies: a comprehensive case study of threatened dwarf galaxias, Galaxiella pusilla (Mack) (Pisces: Galaxiidae).

    PubMed

    Coleman, R A; Weeks, A R; Hoffmann, A A

    2013-04-01

    Genetic markers are widely used to define and manage populations of threatened species based on the notion that populations with unique lineages of mtDNA and well-differentiated nuclear marker frequencies should be treated separately. However, a danger of this approach is that genetic uniqueness might be emphasized at the cost of genetic diversity, which is essential for adaptation and is potentially boosted by mixing geographically separate populations. Here, we re-explore the issue of defining management units, focussing on a detailed study of Galaxiella pusilla, a small freshwater fish of national conservation significance in Australia. Using a combination of microsatellite and mitochondrial markers, 51 populations across the species range were surveyed for genetic structure and diversity. We found an inverse relationship between genetic differentiation and genetic diversity, highlighting a long-term risk of deliberate isolation of G. pusilla populations based on protection of unique lineages. Instead, we adopt a method for identifying genetic management units that takes into consideration both uniqueness and genetic variation. This produced a management framework to guide future translocation and re-introduction efforts for G. pusilla, which contrasted to the framework based on a more traditional approach that may overlook important genetic variation in populations. PMID:23432132

  19. Ailinella mirabilis gen. n., sp. n. (eucestoda: pseudophyllidea) from Galaxias maculatus (Pisces: Galaxiidae) in the Andean-Patagonian region of Argentina.

    PubMed

    de Pertierra, Alicia A Gil; Semenas, Liliana G

    2006-12-01

    Ailinella gen. n. (Pseudophyllidea: Triaenophoridae) is proposed to accommodate Ailinella mirabilis sp. n. from Galaxias maculatus (Jenyns, 1842), a freshwater fish inhabiting the Andean lakes in Argentinean Patagonia. Ailinella belongs to the Triaenophoridae because it has a marginal genital pore, a follicular vitelline gland, and a ventral uterine pore. The new genus can be distinguished from other triaenophorids by the following combination of characters: a small body size, a low number of proglottides, which are longer than wide, a truncated pyramidal to globular scolex, a rectangular apical disc, presence of the neck, lack of internal longitudinal musculature separating the cortex from the medulla, testes distributed in one central field surrounding the ovary laterally and posteriorly, the vagina predominantly anterior to the cirrus sac, vitelline follicles circum-medullary, the genital pores post-equatorial, a saccate uterus, and operculate eggs. Blade-like spiniform microtriches were present on all tegument surfaces, and tumuli on all surfaces of the scolex and the anterior surface of the neck. Microtriches were characterized according to their size and density, and tumuli according to their size, inter-tumulus distance and density. Ailinella mirabilis is the first cestode described from G. maculatus and the second triaenophorid species recorded from a South American freshwater fish. PMID:17256203

  20. Gametogenesis and reproduction of the matrinxã Brycon orthotaenia (Günther, 1864) (Pisces: Characidae) in the São Francisco river, Minas Gerais, Brazil.

    PubMed

    Gonçalves, T L; Bazzoli, N; Brito, M F G

    2006-05-01

    The gametogenesis and reproduction of the matrinxã, Brycon orthotaenia in the São Francisco river, Pirapora Region, Minas Gerais, were studied from December, 1998 to November, 1999. The matrinxã B. orthotaenia is an endemic species in the São Francisco river basin in Brazil and important for commercial fishing. The size of the 1st gonadal maturation, indicated by the total length of the smallest spent males and spawned female, was 32.0 and 40.5 cm respectively. Reproduction occurred from October to January, when high frequencies of females and males at an advanced ripening/mature stage and spawned females were found. The short spawning period and histological characteristics of spawned ovaries containing only oocytes in stages of initial development, along with post-ovulatory and atresic follicles, indicated that Brycon orthotaenia presents total spawning. PMID:16862307

  1. Induction of micronuclei and nuclear abnormalities by cyclophosphamide and colchicine in Xenotoca melanosoma (Pisces, Goodeidae) from Lake La Alberca in Michoacan, Mexico.

    PubMed

    Zavala-Aguirre, Jose Luis; Torres-Bugarin, Olivia; Buelna-Osben, Hector Rene; Flores-Kehn, Lola Paulina; Ramos-Ibarra, Maria Luisa; Zuniga-Gonzalez, Guillermo; Ogura, Tetsuya

    2010-01-01

    This study is a follow-up of previous research in which we described the frequency of spontaneous micronucleated erythrocytes (MNE) in the Goodeid Xenotocoa melanosoma collected from Lake La Alberca, located in the state of Michoacan, Mexico. In the present work, we measured micronuclei (MN) and nuclear abnormalities (NA) in erythrocytes of peripheral blood. Bioassays taken at 24 or 96 hours in either the cyclophosfamide (CP) or colchicine (COL) showed a significant increase in MN and BC (P values ranging from 0.0499 to 0.0036) compared with information from wild organisms collected over 3 years. Concentrationdependent and time-dependent responses support the proposal of using endemic Xenotoca melanosoma as a bioindicator of genotoxicity and cytotoxicity with a high transcendence for the health of the entire ecosystem and evaluation of the Lerma-Chapala watershed. PMID:20390845

  2. Sudden weaning of angel fish pterophyllum scalare (Lichtenstein) (Pisces; Cichlidae) larvae from brine shrimp (Artemia sp) nauplii to formulated larval feed.

    PubMed

    Herath, Sandamali Sakunthala; Atapaththu, Kerthi Sri Senarathna

    2013-12-01

    This study investigated the effects of sudden weaning of angel fish larvae (Pteraphylum scalari) from Artemia nauplii to commercial larval feed. Four days post hatch (DPH) larvae were reared in four different weaning protocols (TR1-TR4) with triplicates in a complete randomize design. Larvae in TR1 and TR4 were exclusively fed Artemia nauplii and dry feed respectively. In TR2 and TR3, larvae were initially fed Artemia nauplii and suddenly wean to formulated feed on 14 DPH and 7 DPH respectively. The experiment was lasted for 28 days. At the end of the experiment, final mean weight (FW), total length (FL), height (FH), Daily Weight Gain (DWG), Specific Growth Rate (SGR), survival and stress index were compared. Significantly highest (P < 0.05) FW, DWG and SGR were observed in TR1 and TR2 while former values of TR3 were not significantly different from TR1. Highest FL observed in TR1 and TR2 while FL of TR2 was statistically similar to that of TR3. The poorest growth was observed in larvae solely fed formulated feed. Survival and the stress index were independent from weaning methods. Although sudden weaning is possible on 7 DPH, larvae showed comparatively higher growth when switch off to formulate feed on 14 DPH. PMID:23626927

  3. The description of Gyrodactylus corleonis sp. n. and G. neretum sp. n. (Platyhelminthes: Monogenea) with comments on other gyrodactylids parasitising pipefish (Pisces: Syngnathidae).

    PubMed

    Paladini, Giuseppe; Cable, Joanne; Fioravanti, Maria Letizia; Faria, Patricia J; Shinn, Andrew P

    2010-03-01

    The current work describes two new species of Gyrodactylus von Nordmann, 1832 collected from pipefish Syngnathus scovelli (Evermann et Kendall) and Syngnathus typhle L. during two separate gyrodactylosis episodes on fish held in a public aquarium located in northern Italy. The gyrodactylids collected from the skin, fins and gills of pipefish were subjected to a morphological analysis of the attachment hooks and the morphometric data were compared to the four species of Gyrodactylus previously described from syngnathid hosts, namely G. eyipayipi Vaughan, Christison, Hansen et Shinn, 2010, G. pisculentui Williams, Kritsky, Dunnigan, Lash et Klein, 2008, G. shorti Holliman, 1963 and G. syngnathi Appleby, 1996. Principal components analysis (PCA) of the morphological data indicated six clusters; two discrete groups among the specimens taken from the pipefisli held in the Italian aquarium and four further groups representing G. eyipayipi, G. pisculentus, G. shorti and G. syngnathi. Molecular sequences of the ribosomal internal transcribed spacers (ITS1 and ITS2) and the 5.8S gene for the new species considered here were then compared with those available for other species in GenBank. The comparison did not reveal any identical match, supporting the morphological analysis that Gyrodactylus corleonis sp. n. from S. typhle and Gyrodactylus neretum sp. n. from S. scovelli represent distinct species. Both G. corleonis and G. neretum possess robust hamuli, marginal hook blades that curve smoothly from their sickle base to a point beyond the toe and, ventral bars with a broad median portion and a reduced membrane. Gyrodactylus corleonis, however, can be distinguished on the basis of its heart-shaped ventral bar; G. neretum has a 1:2 hamulus point:shaft ratio and a rectangular-shaped ventral bar. A redescription of the haptoral hard parts of the four species previously recorded on pipefish is also presented. PMID:20449996

  4. THE GRAY NEEDLE: LARGE GRAINS IN THE HD 15115 DEBRIS DISK FROM LBT /PISCES/Ks AND LBTI /LMIRcam/L' ADAPTIVE OPTICS IMAGING

    SciTech Connect

    Rodigas, Timothy J.; Hinz, Philip M.; Vaitheeswaran, Vidhya; Skemer, Andrew J.; Su, Kate Y. L.; Bailey, Vanessa; Schneider, Glenn; Close, Laird; Apai, Daniel; Leisenring, Jarron; Skrutskie, Michael; Mannucci, Filippo; Esposito, Simone; Arcidiacono, Carmelo; Pinna, Enrico; Argomedo, Javier; Agapito, Guido; Bono, Giuseppe; Briguglio, Runa; Boutsia, Kostantina; and others

    2012-06-10

    We present diffraction-limited Ks band and L' adaptive optics images of the edge-on debris disk around the nearby F2 star HD 15115, obtained with a single 8.4 m primary mirror at the Large Binocular Telescope. At the Ks band, the disk is detected at signal-to-noise per resolution element (SNRE) {approx} 3-8 from {approx}1 to 2.''5 (45-113 AU) on the western side and from {approx}1.''2 to 2.''1 (63-90 AU) on the east. At L' the disk is detected at SNRE {approx} 2.5 from {approx}1 to 1.''45 (45-90 AU) on both sides, implying more symmetric disk structure at 3.8 {mu}m. At both wavelengths the disk has a bow-like shape and is offset from the star to the north by a few AU. A surface brightness asymmetry exists between the two sides of the disk at the Ks band, but not at L'. The surface brightness at the Ks band declines inside 1'' ({approx}45 AU), which may be indicative of a gap in the disk near 1''. The Ks - L' disk color, after removal of the stellar color, is mostly gray for both sides of the disk. This suggests that scattered light is coming from large dust grains, with 3-10 {mu}m sized grains on the east side and 1-10 {mu}m dust grains on the west. This may suggest that the west side is composed of smaller dust grains than the east side, which would support the interpretation that the disk is being dynamically affected by interactions with the local interstellar medium.

  5. Long-term monitoring on the occurrence of a myxosporean parasite Kudoa camarguensis (Myxosporean) on the common goby (Teleostei, pisces) Pomatoschistus microps.

    PubMed

    Pampoulie, C; Marques, A; Rosecchi, E; Bouchereau, J L; Crivelli, A J

    2001-05-01

    The evolution of a host-parasite system composed of Pomatoschistus microps-Kudoa camarguensis was investigated in the Vaccarès lagoon (Rhĵne river Delta, France) from 1993 to 1997. During this long-term monitoring, centennial flooding of the Rhĵne river occurred, leading to an inrush of about 110 million m3 of freshwater in the Vaccarès lagoon. The salinity drastically dropped from 14 to 5 g l(-1) in 1 wk. We observed that the annual prevalence and abundance of the myxosporean parasite decreased from 12.18 in 1993 to 3.7% in 1997 and from 1.10 in 1993 to 0.27 in 1997, respectively. Here, we discuss the possible reasons for the rapid decline of this host-parasite system following the flood. PMID:11411646

  6. Ultrastructure of the spermatozoon of the digenean Tergestia acanthocephala (Stossich, 1887) (Gymnophalloidea: Fellodistomidae): An intestinal parasite of Belone belone gracilis (Pisces: Teleostei).

    PubMed

    Kacem, H; Ndiaye, P I; Neifar, L; Torres, J; Miquel, J

    2015-06-01

    The ultrastructural organization of the spermatozoon of the digenean Tergestia acanthocephala (Gymnophalloidea: Fellodistomidae) is described. Live digeneans were collected from Belone belone gracilis (Teleostei: Belonidae), caught off the Gulf of Gabès in Chebba (Tunisia). The mature spermatozoon of T. acanthocephala exhibits the general pattern described in numerous digeneans, characterized by the presence of two axonemes of the different length of the 9+'1' pattern of the Trepaxonemata, a nucleus, two mitochondria, two bundles of parallel cortical microtubules, external ornamentation, spine-like bodies and granules of glycogen. Moreover, the morphology of the posterior spermatozoon extremity in T. acanthocephala corresponds to the fasciolidean type of Quilichini et al. (2010a). PMID:25796547

  7. Life history, population dynamics and production of eastern mosquitofish, Gambusia holbrooki (Pisces, Poeciliidae), in rice fields of the lower Mondego River Valley, western Portugal

    NASA Astrophysics Data System (ADS)

    Cabral, João Alexandre; Marques, João Carlos

    1999-11-01

    The introduced population of Gambusia holbrooki from the rice fields of the lower Mondego River Valley, Portugal, was studied for 15 months, relating their life cycle and population dynamics with its production, in order to assess the role of the species in the energy flow and secondary production in this type of agro-ecosystem. Two main annual cohorts (1995 and 1996 cohorts) were identified. The females outnumbered males and the average female/male-ratio was 4. The inspection of ovary developmental stages of this viviparous fish, revealed that the most important reproductive period was between April and August. The first recruits were recorded in June and were present thereafter until October. Males from the parental cohort died before August, whereas parental females could survive until October. Mean adjusted fecundity (number of embryos divided by female standard length) peaked in July 1996 (0.95) and in June 1997 (1.05). Females reached greater sizes, had a higher growth rate and lived longer than males. Annual production was estimated at 3.101 g.m -2.year -1 (ash-free dry weight, AFDW), the average biomass at 2.896 g.m -2 (AFDW), and the P/B ratio was 1.071. A conjugation of life history, population dynamics, production and ecological traits (e.g. fast growth, reduced longevity, viviparity, high productivity, an intermediate position in food chain, and no special habitat requirements for reproduction) clearly show that the populations of G. holbrooki, introduced into rice fields all over the world, may play an important role in the structure and functioning of the biological communities of these important agro-ecosystems.

  8. An invasive lineage of sculpins, Cottus sp. (Pisces, Teleostei) in the Rhine with new habitat adaptations has originated from hybridization between old phylogeographic groups

    PubMed Central

    Nolte, Arne W; Freyhof, Jörg; Stemshorn, Kathryn C; Tautz, Diethard

    2005-01-01

    Fish abundance surveys in the Rhine system have shown in the past two decades that there is a rapid upriver invasion of a freshwater sculpin of the genus Cottus. These fish are found in habitats that are atypical for the known species Cottus gobio, which is confined to small cold streams within the Rhine drainage. Phylogeographic analysis based on mitochondrial haplotypes and diagnostic single nucleotide polymorphisms indicates that the invasive sculpins are hybrids between two old lineages from the River Scheldt drainage and the River Rhine drainage, although it is morphologically more similar to the Scheldt sculpins. Most importantly, however, the invasive population possesses a unique ecological potential that does not occur in either of the source populations from the Rhine or the Scheldt, which allows the colonization of new habitats that have previously been free of sculpins. Microsatellite analysis shows that the new lineage is genetically intermediate between the old lineages and that it forms a distinct genetic group across its whole expansion range. We conclude that hybridization between long separated groups has lead to the fast emergence of a new, adaptationally distinct sculpin lineage. PMID:16243698

  9. The migration patterns of the European flounder Platichthys flesus (Linnaeus, 1758) (Pleuronectidae, Pisces) at the southern limit of its distribution range: Ecological implications and fishery management

    NASA Astrophysics Data System (ADS)

    Morais, Pedro; Dias, Ester; Babaluk, John; Antunes, Carlos

    2011-02-01

    This study aims to determine the diversity of migration patterns of the European flounder ( Platichthys flesus (Linnaeus, 1758)) present in the Minho estuary and in the adjacent coastal area (NW-Iberian Peninsula). Assessing the diversity of flounder migration patterns at the southern limit of its distribution allows the determination of characteristics of the species' ecology and provides useful information for fishery managers, since it is a regionally important estuarine fishery. An unexpected result of our study was that flounder appears to spawn in both estuarine and coastal areas and not just in coastal areas as was previously widely accepted. Our interpretation of otolith strontium distribution patterns from flounder specimens collected in the freshwater tidal area of the Minho estuary and in the lower estuary suggested that the flounders hatched in the estuary, while only 6.7% of those captured in the coastal area hatched in the coastal area. Ultimately, studies aimed at collecting larval stages and adult flounders must be made to confirm that flounders spawn in the estuary and to define new and better scientifically supported fishing policies, or simply to confirm the existing ones regarding temporal and spatial closures for each gear used in the Minho estuary.

  10. Measured Copper Toxicity to Cnesterodon decemmaculatus (Pisces: Poeciliidae) and Predicted by Biotic Ligand Model in Pilcomayo River Water: A Step for a Cross-Fish-Species Extrapolation

    PubMed Central

    Casares, María Victoria; de Cabo, Laura I.; Seoane, Rafael S.; Natale, Oscar E.; Castro Ríos, Milagros; Weigandt, Cristian; de Iorio, Alicia F.

    2012-01-01

    In order to determine copper toxicity (LC50) to a local species (Cnesterodon decemmaculatus) in the South American Pilcomayo River water and evaluate a cross-fish-species extrapolation of Biotic Ligand Model, a 96 h acute copper toxicity test was performed. The dissolved copper concentrations tested were 0.05, 0.19, 0.39, 0.61, 0.73, 1.01, and 1.42 mg Cu L−1. The 96 h Cu LC50 calculated was 0.655 mg L−1 (0.823 − 0.488). 96-h Cu LC50 predicted by BLM for Pimephales promelas was 0.722 mg L−1. Analysis of the inter-seasonal variation of the main water quality parameters indicates that a higher protective effect of calcium, magnesium, sodium, sulphate, and chloride is expected during the dry season. The very high load of total suspended solids in this river might be a key factor in determining copper distribution between solid and solution phases. A cross-fish-species extrapolation of copper BLM is valid within the water quality parameters and experimental conditions of this toxicity test. PMID:22523491

  11. Ultrastructural study of spermiogenesis and the spermatozoon of Acanthocephaloides incrassatus (Molin, 1858) (Acanthocephala, Paleacanthocephala, Arhythmacanthidae) from Anguilla anguilla (Pisces, Teleostei) in Urbino ponds (Corsica Island).

    PubMed

    Foata, J; Quilichini, Y; Dal Pos, N; Greani, S; Marchand, B

    2012-07-01

    This study deals with first ultrastructure features of Acanthocephaloides incrassatus (Paleacanthocephala, Arhythmacanthidae), a parasite of the fish Anguilla anguilla, reported for the first time in a Mediterranean pond. The spermiogenesis of A. incrassatus shows original specificities which have never been pointed out to this day in ultrastructural studies on spermiogenesis: the centriolar derivative is divided into two parts of different densities: an electron-dense, and the other, electron-lucent; a ring form has been observed on each side of the axoneme; a centriole with one central element. After the elaboration of a flagellum of 9+2 pattern, the centriole migrates in a nuclear groove. Rapidly, the centriole disappears. Then, the flagellum migration occurs by a series of processes and gives rise to a spermatozoon. The spermatozoon of A. incrassatus presents its own specificities: it exhibits an evolution of the centriolar derivative characterized by only nine peripheral elements deprived of a central element in the anterior part, then nine peripheral and one central element, and finally, nine peripheral elements with two central elements. An assumption is emitted on a probable correspondence of the evolution of the derivative centriolar during the spermiogenesis and the evolution that occurs in the spermatozoon. Protein granules also show different sizes and forms, full or emptied of their contents compared with data on other Acanthocephala. PMID:22307764

  12. A genetic map of Cottus gobio (Pisces, Teleostei) based on microsatellites can be linked to the physical map of Tetraodon nigroviridis.

    PubMed

    Stemshorn, K C; Nolte, A W; Tautz, D

    2005-11-01

    To initiate QTL studies in the nonmodel fish Cottus gobio we constructed a genetic map based on 171 microsatellite markers. The mapping panel consisted of F1 intercrosses between two divergent Cottus lineages from the River Rhine System. Basic local alignment search tool (BLAST) searches with the flanking sequences of the microsatellite markers yielded a significant (e < 10(-5)) hit with the Tetraodon nigroviridis genomic sequence for 45% of the Cottus loci. Remarkably, most of these hits were due to short highly conserved noncoding stretches. These have an average length of 40 bp and are on average 92% conserved. Comparison of the map locations between the two genomes revealed extensive conserved synteny, suggesting that the Tetraodon genomic sequence will serve as an excellent genomic reference for at least the Acanthopterygii, which include evolutionarily interesting fish groups such as guppies (Poecilia), cichlids (Tilapia) or Xiphophorus (Platy). The apparent high density of short conserved noncoding stretches in these fish genomes will highly facilitate the identification of genes that have been identified in QTL mapping strategies of evolutionary relevant traits. PMID:16313473

  13. Optimization of a Cytochrome-P450-Monooxygenase-1A-Mediated EROD Assay in the Cape Hake Species Merluccius capensis and Merluccius paradoxus (Pisces)

    PubMed Central

    De Almeida, Louise; Froneman, William; Pletschke, Brett

    2011-01-01

    Cytochrome P450 monooxygenase 1A (CYP1A) is induced by several planar toxic compounds, for example, polychlorinated biphenyls (PCBs) and the induction of this protein is often measured in terms of CYP1A-mediated 7-ethoxyresorufin-O-deethylase (EROD) activity. This study was aimed at developing this assay in the Cape hake species Merluccius capensis and Merluccius paradoxus (considered one stock). Microsomal fractions were obtained from frozen fish liver samples by differential centrifugation. Fluorimetric and spectrophotometric analysis of the EROD assay resulted in the spectrophotometric (at 572 nm) detection method being selected, as this method resulted in a lower degree of variability and demonstrated higher reproducibility. The activity in the EROD assay was enhanced in the presence of NADPH, and the addition of dicumarol (phase II enzyme inhibitor) to the reaction mixtures prevented the underestimation of this assay by the inhibition of DT-diaphorase. In summary, an EROD assay was established for use in Cape hake species. PMID:22145075

  14. Distribution, population biology, and trophic ecology of the deepwater demersal fish Halosauropsis macrochir (Pisces: Halosauridae) on the mid-Atlantic Ridge.

    PubMed

    Bergstad, Odd Aksel; Clark, Laura; Hansen, Hege Øverbø; Cousins, Nicola

    2012-01-01

    Halosauropsis macrochir ranked amongst the most abundant and widespread demersal fishes on the mid-Atlantic Ridge of the North Atlantic (Iceland-Azores) with greatest abundance at 1700-3500 m. All sizes, ranging from 10-76 cm total length, occurred in the area without any apparent spatial pattern or depth trend. Using otolith sections displaying growth increments assumed to represent annuli, the age range recorded was 2-36 years, but most individuals were <20 years. Length and weight at age data were used to fit growth models. No differences between sexes in length and weight at age were observed. The majority of samples had a surplus of males. Diet analysis showed that H. macrochir feeds on Crustacea, Teleostei, Polychaeta, and Cephalopoda, but few prey could be identified to lower taxonomical levels. The mid-Atlantic Ridge constitutes a major portion of the North Atlantic living space of the abyssal halosaur where it completes its full life cycle, primarily as an actively foraging euryophagous micronekton/epibenthos and infauna feeder, becoming a partial piscivore with increasing size. PMID:22384030

  15. Statistical analysis of anionic detergent-induced changes in the goblet mucous cells of opercular epidermis and gill epithelium of Rita rita (Ham.) (Bagridae: Pisces).

    PubMed

    Roy, D

    1988-06-01

    Rita rita exposed to 96-hr LC50 (6.9 mg/liter) of an anionic detergent, dodecylbenzene sodium sulfonate, show significant changes in the number and size of goblet mucous cells in the opercular epidermis as well as in the lining epithelium of the gill arch and the gill filament at different time intervals of treatment. A shift in the staining nature of these cells from acidic glycoprotein to neutral glycoprotein, acidic glycosaminoglycans in the opercular epidermis and acidic glycoprotein to neutral glycoprotein and then again to acidic glycoprotein + acidic glycosaminoglycans in the gill filament epithelium reflects a change in the physiological status of fish. PMID:3168874

  16. Swimming abilities of wild-caught, late-stage larvae of Diplodus capensis and Sarpa salpa (Pisces: Sparidae) from temperate South Africa

    NASA Astrophysics Data System (ADS)

    Pattrick, Paula; Strydom, Nadine A.

    2009-12-01

    Understanding the movement of marine fish larvae in coastal habitats requires an assessment of active swimming abilities. The critical speed ( U-crit) and endurance swimming of late-stage larvae of Diplodus capensis and Sarpa salpa (Family Sparidae), common inshore recreational linefish species, were measured in a laboratory swimming chamber. Postflexion and settlement-stage larvae were collected from the wild in a small bay on the warm temperate coast of South Africa. Larvae were allowed to acclimate in captivity and were tested soon after capture. For the endurance tests a speed of 18 cm s -1 was selected, as this approximated the mean current speed observed in the coastal environment of the area. The mean U-crit value (maximum swimming speed) for D. capensis (19 cm s -1) was similar to that of S. salpa (18 cm s -1), and similarly mean endurance (km swum) for S. salpa (8 km) was similar to that of D. capensis (6 km). The increase in critical speed and endurance swimming abilities with standard length was best described by a linear relationship. At lengths between 12 and 15 mm BL, D. capensis was the better swimmer, whereas S. salpa was the better swimmer between 15 and 16 mm BL. Of all the larvae that swam at critical speed, 90% were in an inertial environment. These swimming speeds exceed the modal current velocities observed in the shallow nearshore of the study region where these larvae occur abundantly. These swimming abilities provide larvae with the potential to influence their dispersal trajectories and ultimately influence their distribution in their nearshore nursery areas.

  17. A new perspective on phylogeny and evolution of tetraodontiform fishes (Pisces: Acanthopterygii) based on whole mitochondrial genome sequences: Basal ecological diversification?

    PubMed Central

    2008-01-01

    Background The order Tetraodontiformes consists of approximately 429 species of fishes in nine families. Members of the order exhibit striking morphological diversity and radiated into various habitats such as freshwater, brackish and coastal waters, open seas, and deep waters along continental shelves and slopes. Despite extensive studies based on both morphology and molecules, there has been no clear resolution except for monophyly of each family and sister-group relationships of Diodontidae + Tetraodontidae and Balistidae + Monacanthidae. To address phylogenetic questions of tetraodontiform fishes, we used whole mitochondrial genome (mitogenome) sequences from 27 selected species (data for 11 species were newly determined during this study) that fully represent all families and subfamilies of Tetraodontiformes (except for Hollardinae of the Triacanthodidae). Partitioned maximum likelihood (ML) and Bayesian analyses were performed on two data sets comprising concatenated nucleotide sequences from 13 protein-coding genes (all positions included; third codon positions converted into purine [R] and pyrimidine [Y]), 22 transfer RNA and two ribosomal RNA genes (total positions = 15,084). Results The resultant tree topologies from the two data sets were congruent, with many internal branches showing high support values. The mitogenomic data strongly supported monophyly of all families and subfamilies (except the Tetraodontinae) and sister-group relationships of Balistidae + Monacanthidae and Tetraodontidae + Diodontidae, confirming the results of previous studies. However, we also found two unexpected basal splits into Tetraodontoidei (Triacanthidae + Balistidae + Monacanthidae + Tetraodontidae + Diodontidae + Molidae) and Triacanthodoidei (Ostraciidae + Triodontidae + Triacanthodidae). Conclusion This basal split into the two clades has never been reported and challenges previously proposed hypotheses based on both morphology and nuclear gene sequences. It is likely that the basal split had involved ecological diversification, because most members of Tetraodontoidei exclusively occur in shallow waters (freshwater, brackish and coastal waters, and open seas), while those of Triacanthodoidei occur mainly in relatively deep waters along continental shelves and slopes except for more derived ostraciids. This suggests that the basal split between the two clades led to subsequent radiation into the two different habitats. PMID:18638411

  18. [Size and age structure of the striped marlin Tetrapturus audax (Pisces: Xiphidae), at Cabo San Lucas, Baja California sur, México].

    PubMed

    Barrera, Felipe Neri Melo; Uraga, Roberto Felix

    2004-12-01

    The striped marlin (Tetrapturus audax) is found in temperate and tropical waters of the Pacific and Indian Ocean. It is particularly abundant in the southern tip of the Baja California peninsula. Specimens brought to Cabo San Lucas port (22 degrees 53' N y 109 degrees 54' W) by the sport fishery fleet that operates withing a radius of 54 km from 1988 to 1993 were sexes, measured and weighed. A total 1030 individuals were sampled. Dorsal fin spines (389) were collected for age estimation. The spines were sectioned and hyaline-opaque bands counted. The relation of length to spine radius was similar for males and females. The fourth dorsal spine reflected the growth of the fish. The rhythm of growth mark formation is yearly and related to the sea surface temperature. Ten age groups were found and the seventh group was the most abundant, followed by groups "6" and "8". The age structure of the striped marlin was stable in the study period. The observed sizes were 160-280 cm jaw length with 90% of the organisms measuring between 190 and 225 cm. The small individuals recruit to the fishery from June to December. PMID:17354410

  19. A Sensitive CO(1-0) Survey in Pegasus-Pisces; Reducing the Dark Gas Inventory the Old-Fashioned Way

    NASA Astrophysics Data System (ADS)

    Magnani, Loris A.; Donate, Emmanuel

    2016-06-01

    The idea that substantial molecular gas is present in the ISM but is not detectable by the CO(1-0) emission line at 115 GHz has become fairly prevalent in the last decade. This component has come to be known as “dark gas” in the sense that it is hard to trace using the standard spectral line tracers. It is usually identified by gamma-ray or infrared emission, or via the C+ spectral line at 158 microns. However, in determining the dark gas component and comparing it to the molecular gas traced by the CO(1-0) line, existing CO surveys of varying sensitivity are employed. Even the most sensitive CO surveys typically employed in this fashion have at best 1-sigma rms values of about 0.1 K in antenna temperature. We surveyed a small region in the vicinity of the high-latitude molecular cloud MBM 55 in the CO(1-0) line using the Arizona Radio Observatory 12-meter telescope. The 1-sigma rms of our survey (0.02 – 0.03 K) was significantly better than that of typical CO surveys. We detected more CO emission than previous work had found and increased the known H2 in the region by nearly 80%, thereby reducing significantly the contribution from dark gas.

  20. Distribution, Population Biology, and Trophic Ecology of the Deepwater Demersal Fish Halosauropsis macrochir (Pisces: Halosauridae) on the Mid-Atlantic Ridge

    PubMed Central

    Bergstad, Odd Aksel; Clark, Laura; Hansen, Hege Øverbø; Cousins, Nicola

    2012-01-01

    Halosauropsis macrochir ranked amongst the most abundant and widespread demersal fishes on the mid-Atlantic Ridge of the North Atlantic (Iceland-Azores) with greatest abundance at 1700–3500 m. All sizes, ranging from 10–76 cm total length, occurred in the area without any apparent spatial pattern or depth trend. Using otolith sections displaying growth increments assumed to represent annuli, the age range recorded was 2–36 years, but most individuals were <20 years. Length and weight at age data were used to fit growth models. No differences between sexes in length and weight at age were observed. The majority of samples had a surplus of males. Diet analysis showed that H. macrochir feeds on Crustacea, Teleostei, Polychaeta, and Cephalopoda, but few prey could be identified to lower taxonomical levels. The mid-Atlantic Ridge constitutes a major portion of the North Atlantic living space of the abyssal halosaur where it completes its full life cycle, primarily as an actively foraging euryophagous micronekton/epibenthos and infauna feeder, becoming a partial piscivore with increasing size. PMID:22384030

  1. A cytochemical study of the "chloride cells" in the skin of a fresh-water teleost (Channa striata (Bl.) Channidae, Pisces).

    PubMed

    Banerjee, T K; Mittal, A K

    1975-01-01

    The chloride cells in the skin of Channa striata have been described. The cytoplasm of these cells is filled with acidophilic, osmiophilic and sudanophilic granules. The sudanophila is due to phospholipids. These cells give positive reaction for chloride ions and exhibit the presence of neutral mucopolysaccharides. The cytoplasm of these cells is packed with numerous mitochondria and exhibit high succinic dehydrogenase activity which may provide the energy needed for the active transportation of ions. Alkaline phosphatase activity could not be demonstrated in these cells. The presence of chloride cells in comparatively large numbers in the regions where the epidermis is thin is correlated as an adaptation for the increased efficiency of these cells for the transportation of ions so as to maintain the osmotic concentration of its body fluid which is higher than that of the surrounding medium. PMID:127502

  2. Anuretes grandis sp. n., a caligid copepod (Siphonostomatoida) parasitic on Diagramma pictum (Pisces) in Taiwan, with discussion of Anuretes Heller, 1865.

    PubMed

    Ho, J; Lin, C L

    2000-01-01

    A new species of caligid copepod (Siphonostomatoida), Anuretes grandis sp. n., parasitic on the painted sweetlips [Diagramma pictum (Thunberg)] in Taiwan is described. The new species is distinguished from its congeners by having: (1) free margin of cephalothorax not covering fourth pediger, (2) large genital complex longer than 2/3 of the cephalic shield, (3) no maxillary whip, (4) leg 3 with 9 setae on the terminal segment of exopod and 8 plumose setae on the terminal segment of endopod, and (5) armature of I,III on leg 4 exopod. Genus Anuretes Heller, 1865 is reviewed and redefined. Based on the new diagnosis three species (A. chelatus Prabha et Pillai, A. fedderni Price and A. parvulus Wilson) were transferred to Pseudanuretes, and two species (A. furcatus Capart and A. renalis Heegaard) were transferred to Lepeophtheirus. In addition, the following three species of caligids were transferred to Anuretes: Lepeophtheirus fallolunulus Lewis, Heniochophilus indicus Pillai, and Lepeophtheirus rotundigenitalis Prabha et Pillai. The latter is renamed Anuretes occultus nom. n. due to the homonym encountered through this transfer. "Anuretes plectorhynchi Yamaguti" reported by Prabha and Pillai (1986) is renamed Anuretes similis sp. n. and Anuretes yamagutii Prabha et Pillai is relegated to the synonym of Anuretes anomalus Pillai. A key to the 18 species of Anuretes is provided. PMID:11104151

  3. Trophic ecology of the deep-sea fish Malacosteus niger (Pisces: Stomiidae): An enigmatic feeding ecology to facilitate a unique visual system?

    NASA Astrophysics Data System (ADS)

    Sutton, Tracey T.

    2005-11-01

    The deep-sea fish Malacosteus niger belongs to a family of fishes, the dragonfishes (Order: Stomiiformes, Family: Stomiidae), that are among the top predators of the open ocean mesopelagic zone. Malacosteus typifies the morphological adaptation of this group for the taking of relatively large prey. These adaptations include huge fangs, an enormous gape, and the loss of gill rakers. Despite these adaptations, examination of specimens of this species from different ocean basins shows that zooplanktivory is a common feeding mode of the species, an extreme departure from its trophic lineage. Large calanoid copepods made up 69-83% of prey numbers and 9-47% of prey biomass in specimens from the North Atlantic, the Gulf of Mexico, and throughout the Pacific. As M. niger feeding observations have never been reported, the rationale for this enigmatic feeding ecology must be inferred from other aspects of its ecology. As presently known, M. niger is unique among all vertebrates in the possession of both a long-wave bioluminescence system and a bacteriochlorophyll-derived retinal photosensitizer that allows long-wave visual sensitivity. A two-part theory is presented to explain why M. niger radically diverges from its clade and preys on food it does not appear morphologically suited to eat: (1) the combination of long-wave bioluminescence and vision systems suggests that M. niger may search small volumes for food, and thus may sustain itself energetically by snacking on small parcels of food (copepods) in between rare encounters with large prey, and (2) M. niger may gain the raw material for its long-wave visual sensitivity, and thus its feeding mode, from the consumption of copepods.

  4. Stratigraphic context and paleoenvironmental significance of minor taxa (Pisces, Reptilia, Aves, Rodentia) from the late Early Pleistocene paleoanthropological site of Buia (Eritrea).

    PubMed

    Rook, L; Ghinassi, M; Carnevale, G; Delfino, M; Pavia, M; Bondioli, L; Candilio, F; Coppa, A; Martínez-Navarro, B; Medin, T; Papini, M; Zanolli, C; Libsekal, Y

    2013-01-01

    The Buia Homo site, also known as Wadi Aalad, is an East African paleoanthropological site near the village of Buia that, due to its very rich yield from the late Early Pleistocene, has been intensively investigated since 1994. In this paper, which reports on the finds of the 2010-2011 excavations, we include new fossil evidence on previously identified taxa (i.e., reptiles), as well as the very first description of the small mammal, fish and bird remains discovered. In particular, this study documents the discovery of the first African fossil of the genus Burhinus (Aves, Charadriiformes) and of the first rodent from the site. This latter is identified as a thryonomyid rodent (cane rat), a relatively common taxon in African paleoanthropological faunal assemblages. On the whole, the new occurrences documented within the Buia vertebrate assemblage confirm the occurrence of taxa characterized by strong water dependence. The paleoenvironmental characteristics of the fauna are confirmed as fully compatible with the evidence obtained through sedimentology and facies analysis, documenting the sedimentary evolution of fluvio-deltaic and lacustrine systems. PMID:23159190

  5. Big Fish, Little Fish: Two New Ultra-faint Satellites of the Milky Way

    NASA Astrophysics Data System (ADS)

    Belokurov, V.; Walker, M. G.; Evans, N. W.; Gilmore, G.; Irwin, M. J.; Just, D.; Koposov, S.; Mateo, M.; Olszewski, E.; Watkins, L.; Wyrzykowski, L.

    2010-03-01

    We report the discovery of two new Milky Way satellites in the neighboring constellations of Pisces and Pegasus identified in data from the Sloan Digital Sky Survey. Pisces II, an ultra-faint dwarf galaxy lies at the distance of ~180 kpc, some 15° away from the recently detected Pisces I. Segue 3, an ultra-faint star cluster lies at the distance of 16 kpc. We use deep follow-up imaging obtained with the 4-m Mayall Telescope at Kitt Peak National Observatory to derive their structural parameters. Pisces II has a half-light radius of ~60 pc, while Segue 3 is 20 times smaller at only 3 pc.

  6. Origin and dynamic lineage characteristics of the developing Drosophila midgut stem cells.

    PubMed

    Takashima, Shigeo; Aghajanian, Patrick; Younossi-Hartenstein, Amelia; Hartenstein, Volker

    2016-08-15

    Proliferating intestinal stem cells (ISCs) generate all cell types of the Drosophila midgut, including enterocytes, endocrine cells, and gland cells (e.g., copper cells), throughout the lifetime of the animal. Among the signaling mechanisms controlling the balance between ISC self-renewal and the production of different cell types, Notch (N) plays a pivotal role. In this paper we investigated the emergence of ISCs during metamorphosis and the role of N in this process. Precursors of the Drosophila adult intestinal stem cells (pISCs) can be first detected within the pupal midgut during the first hours after onset of metamorphosis as motile mesenchymal cells. pISCs perform 2-3 rounds of parasynchronous divisions. The first mitosis yields only an increase in pISC number. During the following rounds of mitosis, dividing pISCs give rise to more pISCs, as well as the endocrine cells that populate the midgut of the eclosing fly. Enterocytes do not appear among the pISC progeny until around the time of eclosion. The "proendocrine" gene prospero (pros), expressed from mid-pupal stages onward in pISCs, is responsible to advance the endocrine fate in these cells; following removal of pros, pISCs continue to proliferate, but endocrine cells do not form. Conversely, the onset of N activity that occurs around the stage when pros comes on restricts pros expression among pISCs. Loss of N abrogates proliferation and switches on an endocrine fate among all pISCs. Our results suggest that a switch depending on the activity of N and pros acts at the level of the pISC to decide between continued proliferation and endocrine differentiation. PMID:27321560

  7. Methods for design and evaluation of integrated hardware/software systems for concurrent computation

    NASA Technical Reports Server (NTRS)

    Pratt, Terrence W.

    1987-01-01

    Two testbed programming environments to support the evaluation of a large range of parallel architectures have been implemented under the program Parallel Implementation of Scientific Computing Environments (PISCES). The PISCES 1 environment was applied to two areas of aerospace interest: a sparse matrix iterative equation solver and a dynamic scene analysis system. Currently, the NICE/SPAR testbed system for structural analysis is being modified for parallel operation under PISCES 2; the PISCES 1 applications are also being adapted for PISCES 2. A new formal model of concurrent computation has been developed, based on the mathematical system known as H graph semantics together with a timed Petri net model of the parallel aspects of a system.

  8. Post-operative intra-spinal subdural collections after pediatric posterior fossa tumor resection: Incidence, imaging and clinical features

    PubMed Central

    Harreld, Julie H; Mohammed, Noryati; Goldsberry, Grant; Li, Xingyu; Li, Yimei; Boop, Frederick; Patay, Zoltan

    2015-01-01

    Purpose Post-operative intra-spinal subdural collections (PISC) in children after posterior fossa tumor resection may temporarily hinder metastasis detection by MRI or CSF analysis, potentially impacting therapy. We investigated incidence, imaging and clinical features, predisposing factors and time course of PISC after posterior fossa tumor resection. Materials and Methods Retrospective IRB-approved review of post-operative spine MRIs in 243 children (5.5±4.6 years) from our clinical database post-resection of posterior fossa tumors from October 1994-August 2010 yielded 37 (6.0±4.8 years old) PISC+ subjects. Extent and signal properties of PISC were recorded for post-operative (37/37), pre-operative (15/37) and follow-up spine MRIs (35/37). Risk factors were compared to age-matched internal controls (n=37, 5.9±4.5 years). Associations of histology, hydrocephalus and cerebellar tonsillar herniation and post-operative intracranial subdural collections with PISC were assessed by Fisher’s exact test or Chi-square test. Association between pre-operative tumor volume and PISC was assessed by Wilcoxon rank sum test. Results The overall incidence of PISC was 37/243 (15.2%), greatest ≤7 days post-operatively (36%). 97% of PISC were seen 0–41 days post-operatively (12.9±11.0 days). PISC were T2 hyper-intense, iso-intense to CSF on T1WI, homogeneously enhanced and resolved on follow-up MRI (35/35). None were symptomatic. PISC were associated with intracranial subdural collections (p=0.0011) and pre-operative tonsillar herniation (p=0.0228). Conclusion PISC are infrequent, clinically silent and resolve spontaneously, and have a distinctive appearance. Pre-operative tonsillar herniation appears to be a predisposing factor. In this series, repeat MRI by 4 weeks documented improvement or resolution of PISC in 88%. PMID:25614472

  9. A novel offset cancellation based on parasitic-insensitive switched-capacitor sensing circuit for the out-of-plane single-Gimbaled decoupled CMOS-MEMS gyroscope.

    PubMed

    Chang, Ming-Hui; Huang, Han-Pang

    2013-01-01

    This paper presents a novel parasitic-insensitive switched-capacitor (PISC) sensing circuit design in order to obtain high sensitivity and ultra linearity and reduce the parasitic effect for the out-of-plane single-gimbaled decoupled CMOS-MEMS gyroscope (SGDG). According to the simulation results, the proposed PISC circuit has better sensitivity and high linearity in a wide dynamic range. Experimental results also show a better performance. In addition, the PISC circuit can use signal processing to cancel the offset and noise. Thus, this circuit is very suitable for gyroscope measurement. PMID:23493122

  10. A Novel Offset Cancellation Based on Parasitic-Insensitive Switched-Capacitor Sensing Circuit for the Out-of-Plane Single-Gimbaled Decoupled CMOS-MEMS Gyroscope

    PubMed Central

    Chang, Ming-Hui; Huang, Han-Pang

    2013-01-01

    This paper presents a novel parasitic-insensitive switched-capacitor (PISC) sensing circuit design in order to obtain high sensitivity and ultra linearity and reduce the parasitic effect for the out-of-plane single-gimbaled decoupled CMOS-MEMS gyroscope (SGDG). According to the simulation results, the proposed PISC circuit has better sensitivity and high linearity in a wide dynamic range. Experimental results also show a better performance. In addition, the PISC circuit can use signal processing to cancel the offset and noise. Thus, this circuit is very suitable for gyroscope measurement. PMID:23493122

  11. Interspecific Utility of Microsatellites in Fish: A Case Study of (CT)(n) and (GT)(n) Markers in the Shanny Lipophrys pholis (Pisces: Blenniidae) and Their Use in Other Blennioidei.

    PubMed

    Guillemaud; Almada; Serrão Santos R; Cancela

    2000-05-01

    We report the development of new microsatellite markers that can be used for population analyses in the shanny Lipophrys pholis. The procedure involved the construction of a microsatellite-enriched genomic bank. Five (GT)(n) and (CT)(n) microsatellites have been characterized, four of which are polymorphic. The analysis of one population allowed us to verify their usefulness as markers in population studies. Moreover, interspecific amplifications have been performed using primers defined in other species to amplify Lipophrys pholis, or using the primers defined in Lipophrys pholis to amplify other species. We use these results to discuss the hypothesis that microsatellites are highly conserved in fish. PMID:10852803

  12. Chromosomal mapping of H3 histone and 5S rRNA genes in eight species of Astyanax (Pisces, Characiformes) with different diploid numbers: syntenic conservation of repetitive genes.

    PubMed

    Piscor, Diovani; Parise-Maltempi, Patricia Pasquali

    2016-03-01

    The genus Astyanax is widely distributed from the southern United States to northern Patagonia, Argentina. While cytogenetic studies have been performed for this genus, little is known about the histone gene families. The aim of this study was to examine the chromosomal relationships among the different species of Astyanax. The chromosomal locations of the 5S rRNA and H3 histone genes were determined in A. abramis, A. asuncionensis, A. altiparanae, A. bockmanni, A. eigenmanniorum, A. mexicanus (all 2n = 50), A. fasciatus (2n = 46), and A. schubarti (2n = 36). All eight species exhibited H3 histone clusters on two chromosome pairs. In six species (A. abramis, A. asuncionensis, A. altiparanae, A. bockmanni, A. eigenmanniorum, and A. fasciatus), syntenic clusters of H3 histone and 5S rDNA were observed on metacentric (m) or submetacentric (sm) chromosomes. In seven species, clusters of 5S rDNA sequences were located on one or two chromosome pairs. In A. mexicanus, 5S rDNA clusters were located on four chromosome pairs. This study demonstrates that H3 histone clusters are conserved on two chromosome pairs in the genus Astyanax, and specific chromosomal features may contribute to the genomic organization of the H3 histone and 5S rRNA genes. PMID:26835745

  13. Validity of a blue stripe snapper, Lutjanus octolineatus (Cuvier 1828) and a related species, L. bengalensis (Bloch 1790) with a new species (Pisces; Lutjanidae) from the Arabian Sea.

    PubMed

    Iwatsuki, Yukio; Al-Mamry, Juma M; Heemstra, Phillip C

    2016-01-01

    Lutjanus octolineatus (Cuvier 1828), previously considered a junior synonym of Lutjanus bengalensis (Bloch 1790), is shown to be a valid species and lectotypes are designated. Both species are redescribed. The two species have overlapping distributions in the Indian Ocean, but are clearly separable by different dorsal-fin spine counts, blue-striped pattern on the body and the presence or absence of a subocular extension of cheek scales. Lutjanus octovittata (Valenciennes 1830), formerly assigned to synonymy of L. bengalensis, is considered a junior synonym of L. octolineatus based on examination of the holotype. Lutjanus sapphirolineatus n. sp., a species formerly misidentified as L. bengalensis, is described based on 10 specimens from Oman and Somalia. The new species differs from the three species above by a combination of different characters. Analysis of the mitochondrial cytochrome c oxidase subunit 1 (CO1, 603 bp) genetic marker, also strongly supports the validity of each species of the blue-striped snapper complex as distinct. PMID:27394598

  14. Lamellodiscus aff. euzeti Diamanka, Boudaya, Toguebaye & Pariselle, 2011 (Monogenea: Diplectanidae) from the gills of Cheimerius nufar (Valenciennes) (Pisces: Sparidae) collected in the Arabian Sea, with comments on the distribution, specificity and historical biogeography of Lamellodiscus spp.

    PubMed

    Machkewskyi, Volodymyr K; Dmitrieva, Evgenija V; Gibson, David I; Al-Jufaili, Sara

    2014-11-01

    Specimens of Lamellodiscus Johnston & Tiegs, 1922 (Monogenea: Diplectanidae) were collected from the gills of Cheimerius nufar (Valenciennes) (Sparidae) in the Arabian Sea. All of these parasites belonged to one and the same species, which is morphologically very close to L. euzeti Diamanka, Boudaya, Toguebaye & Pariselle, 2011. A different host, distant locality and small morphological differences compared with the original description of L. euzeti acted as a stimulus for a detailed redescription. The specimens from the Arabian Sea differ slightly in the details of the male copulatory organ (MCO) from the type-specimens of L. euzeti, which were re-examined, and from the respective drawings in its original description. Such differences include a longer inner process of the large element of the accessory piece associated with the proximal part of the copulatory tube, a longer point on the small element of the accessory piece associated with the distal part of the copulatory tube, and the presence of a smooth or slightly folded inner margin of this element rather than structures resembling spines which occur in the type-specimens of L. euzeti. Therefore, the present specimens infecting C. nufar in the Indo-Pacific may represent a different, but morphologically very similar species to the Atlantic form L. euzeti; consequently, they are recognised here as Lamellodiscus aff. euzeti. This form belongs to the 'ignoratus s. str.' subgroup of the genus. The composition of this subgroup is redefined to comprise 17 species, including L. corallinus Paperna, 1965 but excluding L. acanthopagri Roubal, 1981, and the morphology of the MCO of representatives of this group is clarified. A link between the diversity of Lamellodiscus species and the ancestral origin of present-day sparid species in the Tethys Sea is suggested. It is shown that Lamellodiscus spp. exhibit rather high levels of specificity to their hosts, since half of them parasitise only a single host species and c.90% infect closely related host species. Comparison of the levels of host-specificity of the species of this genus with other narrowly specific genera of the Dactylogyridea revealed that their estimations are comparable. The possibility of intra-host speciation within Lamellodiscus is discussed. It is shown that a co-evolutionary model is more discernible if it includes data on the occurrence of morphologically similar species from different regions and host taxa. PMID:25301511

  15. BIG FISH, LITTLE FISH: TWO NEW ULTRA-FAINT SATELLITES OF THE MILKY WAY

    SciTech Connect

    Belokurov, V.; Walker, M. G.; Evans, N. W.; Gilmore, G.; Irwin, M. J.; Koposov, S.; Watkins, L.; Wyrzykowski, L.; Just, D.; Olszewski, E.; Mateo, M. E-mail: walker@ast.cam.ac.uk

    2010-03-20

    We report the discovery of two new Milky Way satellites in the neighboring constellations of Pisces and Pegasus identified in data from the Sloan Digital Sky Survey. Pisces II, an ultra-faint dwarf galaxy lies at the distance of {approx}180 kpc, some 15 deg. away from the recently detected Pisces I. Segue 3, an ultra-faint star cluster lies at the distance of 16 kpc. We use deep follow-up imaging obtained with the 4-m Mayall Telescope at Kitt Peak National Observatory to derive their structural parameters. Pisces II has a half-light radius of {approx}60 pc, while Segue 3 is 20 times smaller at only 3 pc.

  16. MoonRIDERS: NASA and Hawaii's Lunar Surface Flight Experiment for Late 2016

    NASA Astrophysics Data System (ADS)

    Kelso, R. M.

    2015-10-01

    This briefing will update the MoonRIDERS lunar surface flight experiment project between NASA-KSC, PISCES, and two Hawaii high schools investigating critical lunar dust-removal technologies. Launch planned in early 2017 on GLXP mission.

  17. First Point of Aries

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    An alternative term for vernal equinox. At one time (some 2000 years ago) the vernal equinox lay in the constellation of Aries but, due to precession, this is no longer the case and the vernal equinox has moved into Pisces....

  18. Automated mapping of persistent ice and snow cover across the western U.S. with Landsat

    NASA Astrophysics Data System (ADS)

    Selkowitz, David J.; Forster, Richard R.

    2016-07-01

    We implemented an automated approach for mapping persistent ice and snow cover (PISC) across the conterminous western U.S. using all available Landsat TM and ETM+ scenes acquired during the late summer/early fall period between 2010 and 2014. Two separate validation approaches indicate this dataset provides a more accurate representation of glacial ice and perennial snow cover for the region than either the U.S. glacier database derived from US Geological Survey (USGS) Digital Raster Graphics (DRG) maps (based on aerial photography primarily from the 1960s-1980s) or the National Land Cover Database 2011 perennial ice and snow cover class. Our 2010-2014 Landsat-derived dataset indicates 28% less glacier and perennial snow cover than the USGS DRG dataset. There are larger differences between the datasets in some regions, such as the Rocky Mountains of Northwest Wyoming and Southwest Montana, where the Landsat dataset indicates 54% less PISC area. Analysis of Landsat scenes from 1987-1988 and 2008-2010 for three regions using a more conventional, semi-automated approach indicates substantial decreases in glaciers and perennial snow cover that correlate with differences between PISC mapped by the USGS DRG dataset and the automated Landsat-derived dataset. This suggests that most of the differences in PISC between the USGS DRG and the Landsat-derived dataset can be attributed to decreases in PISC, as opposed to differences between mapping techniques. While the dataset produced by the automated Landsat mapping approach is not designed to serve as a conventional glacier inventory that provides glacier outlines and attribute information, it allows for an updated estimate of PISC for the conterminous U.S. as well as for smaller regions. Additionally, the new dataset highlights areas where decreases in PISC have been most significant over the past 25-50 years.

  19. Semiconductor device modeling on a workstation

    SciTech Connect

    Diegert, C.

    1985-09-01

    We choose to move from large mainframe computers to workstations to gain the interactive graphics we need to prepare and to analyze semiconductor device modeling problems. Given this much on a workstation, it is convenient to attempt to solve the entire problem there. We find that a top-of-the-line Apollo 660 workstation, with bit-slice processor, pipelined arithmetic processor, and 4 megabytes of real memory, is surprisingly effective in finding solutions when running the Pisces II device modeling code. In our experiment we find where the workstation bogs down when running these problems. We both analyze the Pisces CPU time log and we sample the executing program to accumulate a histogram of execution time as distributed over the source code. Results suggest how Pisces could be adapted to solve somewhat larger problems entirely on the workstation. Evolution of a trusted derivative of Pisces, to be used on supercomputers without interactivity, is suggested to complement our success with Pisces on workstations. 4 refs.

  20. Resistance to the herbicide paraquat and increased tolerance to photoinhibition are not correlated in several weed species.

    PubMed

    Preston, C; Holtum, J A; Powles, S B

    1991-05-01

    Photoinhibition was examined in paraquat-resistant and paraquat-susceptible biotypes of Hordeum glaucum Steud., Hordeum leporinum Link., Arctotheca calendula (L.) Levyns., and Conyza bonariensis (L.) Cronq. Plants were photoinhibited at low temperature, and the extent of photoinhibition determined by O(2) evolution and 77 K fluorescence. No difference in the degree of photoinhibition was detected between paraquat-resistant and paraquat-susceptible biotypes for any of the species examined. C. bonariensis plants were also photoinhibited by treatment without CO(2) at either 21% (volume/volume) O(2) or 4% (volume/volume) O(2), and again no difference was observed between the paraquat-resistant and paraquat-susceptible biotypes in reduction of the ratio of variable fluorescence to maximal fluorescence. This is in contrast to a recent report (MAK Jansen, Y Shaaltiel, D Kazzes, O Canaani, S Malkin, J Gressel, [1989] Plant Physiol 91: 1174-1178 in which it was claimed that a paraquat-resistant biotype of C. bonariensis was more tolerant of photoinhibition than a paraquat-susceptible biotype. We conclude that paraquat-resistant biotypes of these plant species are not more tolerant of photoinhibition when compared with the paraquat-susceptible biotypes. PMID:16668172

  1. The effect of several adjuvants on glufosinate effectiveness in Conyza species.

    PubMed

    Fernandez-Cerejido, M C; Bastida, F; Menendez, J

    2009-01-01

    The effect of several adjuvants on the effectiveness of glufosinate and the role of adherence and contact angle modifications due to the presence of these adjuvants in the spraying solution on the increase in efficacy observed on the broadleaved weeds Conyza albida and Conyza bonariensis has been determined under laboratory controlled conditions. The adjuvants used on the experiment were a mixture of methyl oleate and palmitate (MO/MP), a dodecylbenzene ammonium sulphonate (DBAS), a paraffinic oil (PO), an alkylglycol ester (AGE), and a lecithin + propionic acid + non ionic surfactant based product (LI-700). Dose-response experiments showed that C. albida displayed higher susceptibility to glufosinate than C. bonariensis, no matter the adjuvant tested. However, none of the mixtures increased the herbicide effectiveness on C. atlbida, with LI 700 and PO showing an antagonistic effect on the herbicide efficacy. On C. bonariensis, MO/MP and DBAS showed significant better results than non-amended glufosinate controls, with LI 700 showing again an antagonistic effect. Both adherence and contact angle studies were inconclusive, since adjuvants with best adherence and contact angle values were not the most effective ones. Therefore, other unknown parameters putatively modified by adjuvants such as herbicide penetration should be questioned. PMID:20222614

  2. Resistance to the Herbicide Paraquat and Increased Tolerance to Photoinhibition Are Not Correlated in Several Weed Species 1

    PubMed Central

    Preston, Christopher; Holtum, Joseph A. M.; Powles, Stephen B.

    1991-01-01

    Photoinhibition was examined in paraquat-resistant and paraquat-susceptible biotypes of Hordeum glaucum Steud., Hordeum leporinum Link., Arctotheca calendula (L.) Levyns., and Conyza bonariensis (L.) Cronq. Plants were photoinhibited at low temperature, and the extent of photoinhibition determined by O2 evolution and 77 K fluorescence. No difference in the degree of photoinhibition was detected between paraquat-resistant and paraquat-susceptible biotypes for any of the species examined. C. bonariensis plants were also photoinhibited by treatment without CO2 at either 21% (volume/volume) O2 or 4% (volume/volume) O2, and again no difference was observed between the paraquat-resistant and paraquat-susceptible biotypes in reduction of the ratio of variable fluorescence to maximal fluorescence. This is in contrast to a recent report (MAK Jansen, Y Shaaltiel, D Kazzes, O Canaani, S Malkin, J Gressel, [1989] Plant Physiol 91: 1174-1178 in which it was claimed that a paraquat-resistant biotype of C. bonariensis was more tolerant of photoinhibition than a paraquat-susceptible biotype. We conclude that paraquat-resistant biotypes of these plant species are not more tolerant of photoinhibition when compared with the paraquat-susceptible biotypes. PMID:16668172

  3. Trophic interactions between native and introduced fish species in a littoral fish community.

    PubMed

    Monroy, M; Maceda-Veiga, A; Caiola, N; De Sostoa, A

    2014-11-01

    The trophic interactions between 15 native and two introduced fish species, silverside Odontesthes bonariensis and rainbow trout Oncorhynchus mykiss, collected in a major fishery area at Lake Titicaca were explored by integrating traditional ecological knowledge and stable-isotope analyses (SIA). SIA suggested the existence of six trophic groups in this fish community based on δ(13)C and δ(15)N signatures. This was supported by ecological evidence illustrating marked spatial segregation between groups, but a similar trophic level for most of the native groups. Based on Bayesian ellipse analyses, niche overlap appeared to occur between small O. bonariensis (<90 mm) and benthopelagic native species (31.6%), and between the native pelagic killifish Orestias ispi and large O. bonariensis (39%) or O. mykiss (19.7%). In addition, Bayesian mixing models suggested that O. ispi and epipelagic species are likely to be the main prey items for the two introduced fish species. This study reveals a trophic link between native and introduced fish species, and demonstrates the utility of combining both SIA and traditional ecological knowledge to understand trophic relationships between fish species with similar feeding habits. PMID:25263642

  4. A Prototype Integral Field Spectrograph for High Contrast Visible-Light Imaging Spectroscopy of Jovian and Terrestrial Worlds

    NASA Astrophysics Data System (ADS)

    Perrin, M.

    2014-04-01

    We present the design and status of PISCES, a visible light (0.4-1 micron) integral field spectrograph (IFS) being developed for NASA's High Contrast Imaging Testbed at the Jet Propulsion Laboratory. PISCES, the Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies, is a lenslet-based IFS with diffraction limited spatial sampling and a spectral resolution of ~70. It will be a laboratory prototype for future space instruments intended for exoplanet characterization via high contrast imaging, for instance imaging of Jovian and Neptunian class planets with the AFTA Coronagraph and eventually terrestrial planets with a future TPF/ATLAST/NWO type mission. PISCES will demonstrate visible light imaging spectroscopy at the challenging contrast levels required for direct detection and characterization of habitable exoplanets, and is compatible with both coronagraph and starshade mission concepts.

  5. Expanding the Planetary Analog Test Sites in Hawaii - Planetary Basalt Manipulation

    NASA Astrophysics Data System (ADS)

    Kelso, R.

    2013-12-01

    The Pacific International Space Center for Exploration Systems (PISCES) is one of the very few planetary surface research test sites in the country that is totally funded by the state legislature. In recent expansions, PISCES is broadening its work in planetary test sites to include much more R&D work in the planetary surface systems, and the manipulation of basalt materials. This is to include laser 3D printing of basalt, 'lunar-concrete' construction in state projects for Hawaii, renewable energy, and adding lava tubes/skylights to their mix of high-quality planetary analog test sites. PISCES Executive Director, Rob Kelso, will be providing program updates on the interest of the Hawaii State Legislature in planetary surface systems, new applied research initiatives in planetary basalts and interests in planetary construction.

  6. A campaign to end animal testing: introducing the PETA International Science Consortium Ltd.

    PubMed

    Stoddart, Gilly; Brown, Jeffrey

    2014-12-01

    The successful development and validation of non-animal techniques, or the analysis of existing data to satisfy regulatory requirements, provide no guarantee that this information will be used in place of animal experiments. In order to advocate for the replacement of animal-based testing requirements, the PETA International Science Consortium Ltd (PISC) liaises with industry, regulatory and research agencies to establish and promote clear paths to validation and regulatory use of non-animal techniques. PISC and its members use an approach that identifies, promotes and verifies the implementation of good scientific practices in place of testing on animals. Examples of how PISC and its members have applied this approach to minimise the use of animals for the Registration, Evaluation, Authorisation and Restriction of Chemicals regulation in the EU and testing of cosmetics on animals in India, are described. PMID:25635647

  7. A language comparison for scientific computing on MIMD architectures

    NASA Technical Reports Server (NTRS)

    Jones, Mark T.; Patrick, Merrell L.; Voigt, Robert G.

    1989-01-01

    Choleski's method for solving banded symmetric, positive definite systems is implemented on a multiprocessor computer using three FORTRAN based parallel programming languages, the Force, PISCES and Concurrent FORTRAN. The capabilities of the language for expressing parallelism and their user friendliness are discussed, including readability of the code, debugging assistance offered, and expressiveness of the languages. The performance of the different implementations is compared. It is argued that PISCES, using the Force for medium-grained parallelism, is the appropriate choice for programming Choleski's method on the multiprocessor computer, Flex/32.

  8. Measuring helium bubble diameter distributions in tungsten with grazing incidence small angle x-ray scattering (GISAXS)

    NASA Astrophysics Data System (ADS)

    Thompson, M.; Kluth, P.; Doerner, R. P.; Kirby, N.; Riley, D.; Corr, C. S.

    2016-02-01

    Grazing incidence small angle x-ray scattering was performed on tungsten samples exposed to helium plasma in the MAGPIE and Pisces-A linear plasma devices to measure the size distributions of resulting helium nano-bubbles. Nano-bubbles were fitted assuming spheroidal particles and an exponential diameter distribution. These particles had mean diameters between 0.36 and 0.62 nm. Pisces-A exposed samples showed more complex patterns, which may suggest the formation of faceted nano-bubbles or nano-scale surface structures.

  9. Learning Directory 1970-71. A Comprehensive Guide to Instructional Materials in All Media. Volume I, Users Guide, Source Index, Instructional Materials Index A-Boun; Volume II, Bourq-Dros; Volume III, Drou-Gree; Volume IV, Greg-Mari; Volume V, Mark-Pisc; Volume VI, Pise-Smel; Volume VII, Smer-Z, 0-9.

    ERIC Educational Resources Information Center

    Westinghouse Learning Corp., New York, NY.

    Over 200,000 distinct items of instructional material are indexed in this seven volume annual directory. They are presented in 600,000 entries under more than 225,000 different topics. Information in the directory is divided into two sections: the instructional materials index and the source index. The instructional materials index is organized…

  10. Comprehensive phylogenetic analysis of all species of swordtails and platies (Pisces: Genus Xiphophorus) uncovers a hybrid origin of a swordtail fish, Xiphophorus monticolus, and demonstrates that the sexually selected sword originated in the ancestral lineage of the genus, but was lost again secondarily

    PubMed Central

    2013-01-01

    Background Males in some species of the genus Xiphophorus, small freshwater fishes from Meso-America, have an extended caudal fin, or sword – hence their common name “swordtails”. Longer swords are preferred by females from both sworded and – surprisingly also, non-sworded (platyfish) species that belong to the same genus. Swordtails have been studied widely as models in research on sexual selection. Specifically, the pre-existing bias hypothesis was interpreted to best explain the observed bias of females in presumed ancestral lineages of swordless species that show a preference for assumed derived males with swords over their conspecific swordless males. However, many of the phylogenetic relationships within this genus still remained unresolved. Here we construct a comprehensive molecular phylogeny of all 26 known Xiphophorus species, including the four recently described species (X. kallmani, X. mayae, X. mixei and X. monticolus). We use two mitochondrial and six new nuclear markers in an effort to increase the understanding of the evolutionary relationships among the species in this genus. Based on the phylogeny, the evolutionary history and character state evolution of the sword was reconstructed and found to have originated in the common ancestral lineage of the genus Xiphophorus and that it was lost again secondarily. Results We estimated the evolutionary relationships among all known species of the genus Xiphophorus based on the largest set of DNA markers so far. The phylogeny indicates that one of the newly described swordtail species, Xiphophorus monticolus, is likely to have arisen through hybridization since it is placed with the southern platyfish in the mitochondrial phylogeny, but with the southern swordtails in the nuclear phylogeny. Such discordance between these two types of markers is a strong indication for a hybrid origin. Additionally, by using a maximum likelihood approach the possession of the sexually selected sword trait is shown to be the most likely ancestral state for the genus Xiphophorus. Further, we provide a well supported estimation of the phylogenetic relationships between the previously unresolved northern swordtail groups. Conclusions This comprehensive molecular phylogeny of the entire genus Xiphophorus provides evidence that a second swordtail species, X. monticolus, arose through hybridization. Previously, we demonstrated that X. clemenciae, another southern swordtail species, arose via hybridization. These findings highlight the potential key role of hybridization in the evolution of this genus and suggest the need for further investigations into how hybridization contributes to speciation more generally. PMID:23360326

  11. The era of Aries and Kriophoros statues

    NASA Astrophysics Data System (ADS)

    Theodossiou, E.; Mantarakis, P.; Dimitrijević, M. S.

    We discuss the possibility that the great number of ancient Greek statues of Kriophoros (= `ram-bearer') before 1 BC may have been the result of religious influence stemming from the knowledge that the constellation of Aries marked the point of vernal equinox rather than Pisces.

  12. Multiplex matrix network analysis of protein complexes in the human TCR signalosome.

    PubMed

    Smith, Stephen E P; Neier, Steven C; Reed, Brendan K; Davis, Tessa R; Sinnwell, Jason P; Eckel-Passow, Jeanette E; Sciallis, Gabriel F; Wieland, Carilyn N; Torgerson, Rochelle R; Gil, Diana; Neuhauser, Claudia; Schrum, Adam G

    2016-01-01

    Multiprotein complexes transduce cellular signals through extensive interaction networks, but the ability to analyze these networks in cells from small clinical biopsies is limited. To address this, we applied an adaptable multiplex matrix system to physiologically relevant signaling protein complexes isolated from a cell line or from human patient samples. Focusing on the proximal T cell receptor (TCR) signalosome, we assessed 210 pairs of PiSCES (proteins in shared complexes detected by exposed surface epitopes). Upon stimulation of Jurkat cells with superantigen-loaded antigen-presenting cells, this system produced high-dimensional data that enabled visualization of network activity. A comprehensive analysis platform generated PiSCES biosignatures by applying unsupervised hierarchical clustering, principal component analysis, an adaptive nonparametric with empirical cutoff analysis, and weighted correlation network analysis. We generated PiSCES biosignatures from 4-mm skin punch biopsies from control patients or patients with the autoimmune skin disease alopecia areata. This analysis distinguished disease patients from the controls, detected enhanced basal TCR signaling in the autoimmune patients, and identified a potential signaling network signature that may be indicative of disease. Thus, generation of PiSCES biosignatures represents an approach that can provide information about the activity of protein signaling networks in samples including low-abundance primary cells from clinical biopsies. PMID:27485017

  13. [Zooplankton of the Costa Rica Dome: taxonomy and biogeography].

    PubMed

    Vicencio Aguilar, M E; Fernández Alamo, M A

    1996-08-01

    A list of the species and taxa of some pelagic animals from a tropical upwelling region, based on collections made off the coast of Costa Rica is presented. The list includes a total of 224 species, 53 genera and 11 subspecific forms in Cnidaria, Annelida, Mollusca, Artropoda (Crustacea), Chaetognatha and Pisces. PMID:9246370

  14. Development of the Drosophila entero-endocrine lineage and its specification by the Notch signaling pathway.

    PubMed

    Takashima, Shigeo; Adams, Katrina L; Ortiz, Paola A; Ying, Chong T; Moridzadeh, Rameen; Younossi-Hartenstein, Amelia; Hartenstein, Volker

    2011-05-15

    In this paper we have investigated the developmental-genetic steps that shape the entero-endocrine system of Drosophila melanogaster from the embryo to the adult. The process starts in the endoderm of the early embryo where precursors of endocrine cells and enterocytes of the larval midgut, as well as progenitors of the adult midgut, are specified by a Notch signaling-dependent mechanism. In a second step that occurs during the late larval period, enterocytes and endocrine cells of a transient pupal midgut are selected from within the clusters of adult midgut progenitors. As in the embryo, activation of the Notch pathway triggers enterocyte differentiation and inhibits cells from further proliferation or choosing the endocrine fate. The third step of entero-endocrine cell development takes place at a mid-pupal stage. Before this time point, the epithelial layer destined to become the adult midgut is devoid of endocrine cells. However, precursors of the intestinal midgut stem cells (pISCs) are already present. After an initial phase of symmetric divisions which causes an increase in their own population size, pISCs start to spin off cells that become postmitotic and express the endocrine fate marker, Prospero. Activation of Notch in pISCs forces these cells into an enterocyte fate. Loss of Notch function causes an increase in the proliferatory activity of pISCs, as well as a higher ratio of Prospero-positive cells. PMID:21382366

  15. Development of the Drosophila entero-endocrine lineage and its specification by the Notch signaling pathway

    PubMed Central

    Takashima, Shigeo; Adams, Katrina L.; Ortiz, Paola A.; Ying, Chong T.; Moridzadeh, Rameen; Younossi-Hartenstein, Amelia; Hartenstein, Volker

    2013-01-01

    In this paper we have investigated the developmental-genetic steps that shape the entero-endocrine system of Drosophila melanogaster from the embryo to the adult. The process starts in the endoderm of the early embryo where precursors of endocrine cells and enterocytes of the larval midgut, as well as progenitors of the adult midgut, are specified by a Notch signaling-dependent mechanism. In a second step that occurs during the late larval period, enterocytes and endocrine cells of a transient pupal midgut are selected from within the clusters of adult midgut progenitors. As in the embryo, activation of the Notch pathway triggers enterocyte differentiation, and inhibits cells from further proliferation or choosing the endocrine fate. The third step of entero-endocrine cell development takes place at a mid-pupal stage. Before this time point, the epithelial layer destined to become the adult midgut is devoid of endocrine cells. However, precursors of the intestinal midgut stem cells (pISCs) are already present. After an initial phase of symmetric divisions which causes an increase in their own population size, pISCs start to spin off cells that become postmitotic and express the endocrine fate marker, Prospero. Activation of Notch in pISCs forces these cells into an enterocyte fate. Loss of Notch function causes an increase in the proliferatory activity of pISCs, as well as a higher ratio of Prospero-positive cells. PMID:21382366

  16. Investigation of single-event upset (SEU) in an advanced bipolar process

    NASA Technical Reports Server (NTRS)

    Zoutendyk, John A.; Secrest, Elaine C.; Berndt, Dale F.

    1988-01-01

    An extensive analytical and experimental study SEU in an advanced silicon bipolar process was made. The modeling used process and device parameters to model the SEU charge, collection, and circuit response derived from a special version of PISCES in cylindrical coordinates and SPICE, respectively. Data are reported for test cells of various sizes.

  17. The interaction of heavy metals and nutrients present in soil and native plants with arbuscular mycorrhizae on the riverside in the Matanza-Riachuelo River Basin (Argentina).

    PubMed

    Mendoza, Rodolfo E; García, Ileana V; de Cabo, Laura; Weigandt, Cristian F; Fabrizio de Iorio, Alicia

    2015-02-01

    This study assessed the contamination by heavy metals (Cr, Cu, Pb, Zn), and nutrients (N, P) in soils and native plants, and the effect of the concentration of those elements with the density of arbuscular-mycorrhizal (AM) spores in soil and colonization in roots from the riverside of the Matanza-Riachuelo River Basin (MRRB). The concentration of metals and nutrients in soils and plants (Eleocharis montana, Cyperus eragrostis, Hydrocotyle bonariensis) increased from the upper sites (8 km from headwaters) to the lower sites (6 km from the mouth of the Riachuelo River) of the basin. AM-colonization on the roots of H. bonariensis and spore density in soil decreased as the concentrations of metals in soil and plant tissues increased from the upper to lower sites of the basin within a consistent gradient of contamination associated with land use, soil disturbance, population, and chemicals discharged into the streams and rivers along the MRRB. The general trends for all metals in plant tissue were to have highest concentrations in roots, then in rhizomes and lowest in aerial biomass. The translocation (TF) and bioconcentration (BCF) factors decreased in plants which grow from the upper sites to the lower sites of the basin. The plants tolerated a wide range in type and quantity of contamination along the basin by concentrating more metals and nutrients in roots than in aboveground tissue. The AM spore density in soil and colonization in roots of H. bonariensis decreased with the increase of the degree of contamination (Dc) in soil. PMID:25461058

  18. Persistent organic pollutants (POPs) in fish with different feeding habits inhabiting a shallow lake ecosystem.

    PubMed

    Barni, María F Silva; Ondarza, Paola M; Gonzalez, Mariana; Da Cuña, Rodrigo; Meijide, Fernando; Grosman, Fabián; Sanzano, Pablo; Lo Nostro, Fabiana L; Miglioranza, Karina S B

    2016-04-15

    The occurrence of persistent organic pollutants (POPs) in the environment can affect organisms inhabiting aquatic systems, in particular shallow lakes that are vulnerable to environmental stressors. This study aimed to assess POPs accumulation and changes at histological and physiological levels in tissues of three fish species with different trophic habits. Gills, brain, muscle, liver and gonads of Odontesthes bonariensis, Oligosarcus jenynsii and Cyphocharax voga were collected from the shallow lake La Peregrina, located in an agricultural area from Argentina. In addition, contaminant levels in surface water (SW), suspended particulate matter (SPM) and bottom sediments (BS) were assessed. Histological lesions were evaluated in fish tissues and levels of vitellogenin (VTG) were assessed in plasma of male fish in order to correlate these alterations with the presence of POPs in the environment. Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were determined by GC-ECD. Biotic and abiotic samples showed the same POPs distribution pattern: OCPs>PCBs>PBDEs. Although tissue distribution of OCPs was species-specific, muscle showed the lowest levels in all species. The most abundant contaminants were endosulfans, suggesting their widespread use in the area. O. bonariensis showed the highest endosulfans levels in liver (184.2-219ngg(-1)wet w), which was associated with the high SPM levels considering this species is a filter feeder. The occurrence of PCBs and PBDEs shows the ubiquity of these pollutants in the area. Histological lesions in gills and liver of O. bonariensis and O. jenynsii, might be related with the high levels of endosulfans in these organs. The detection of VTG in males warns about a possible exposure to estrogenic compounds in the environment. In conclusion, the simultaneous exposure of fish to multiple environmental pollutants leads to different alterations, so measures should be taken in

  19. Multi-locus fossil-calibrated phylogeny of Atheriniformes (Teleostei, Ovalentaria).

    PubMed

    Campanella, Daniela; Hughes, Lily C; Unmack, Peter J; Bloom, Devin D; Piller, Kyle R; Ortí, Guillermo

    2015-05-01

    Phylogenetic relationships among families within the order Atheriniformes have been difficult to resolve on the basis of morphological evidence. Molecular studies so far have been fragmentary and based on a small number taxa and loci. In this study, we provide a new phylogenetic hypothesis based on sequence data collected for eight molecular markers for a representative sample of 103 atheriniform species, covering 2/3 of the genera in this order. The phylogeny is calibrated with six carefully chosen fossil taxa to provide an explicit timeframe for the diversification of this group. Our results support the subdivision of Atheriniformes into two suborders (Atherinopsoidei and Atherinoidei), the nesting of Notocheirinae within Atherinopsidae, and the monophyly of tribe Menidiini, among others. We propose taxonomic changes for Atherinopsoidei, but a few weakly supported nodes in our phylogeny suggests that further study is necessary to support a revised taxonomy of Atherinoidei. The time-calibrated phylogeny was used to infer ancestral habitat reconstructions to explain the current distribution of marine and freshwater taxa. Based on these results, the current distribution of Atheriniformes is likely due to widespread marine dispersal along the margins of continents, infrequent trans-oceanic dispersal, and repeated invasion of freshwater habitats. This conclusion is supported by post-Gondwanan divergence times among families within the order, and a high probability of a marine ancestral habitat. PMID:25769409

  20. Differential susceptibility to glyphosate among the Conyza weed species in Spain.

    PubMed

    González-Torralva, Fidel; Cruz-Hipolito, Hugo; Bastida, Fernando; Mülleder, Norbert; Smeda, Reid J; De Prado, Rafael

    2010-04-14

    Greenhouse and laboratory experiments were conducted to investigate differences in glyphosate susceptibility among three species of the genus Conyza introduced as weeds in Spain: tall fleabane (Conyza sumatrensis), hairy fleabane (Conyza bonariensis), and horseweed (Conyza canadensis). Plant material was obtained from seeds collected in weed populations growing in olive groves and citrus orchards in southern Spain, with no previous history of glyphosate application. Dose-response curves displayed ED(50) values of 2.9, 15.7, and 34.9 g ai ha(-1), respectively, for C. sumatrensis, C. bonariensis, and C. canadensis plants at the rosette stage (6-8 leaves). Significant differences were found among the three species in the glyphosate retention on leaves as well as the leaf contact angle. The species order according to glyphosate retention was C. sumatrensis > C. bonariensis > C. canadensis, while the mean contact angles of glyphosate droplets were 59.2, 65.5, and 72.9 degrees , respectively. There were no significant differences among species in the absorption of [(14)C]glyphosate (ranged from 37.4% for C. canadensis to 52.4% for C. sumatrensis), but the order among species was the same as glyphosate retention. The amount of radioactivity translocated from treated leaves was lower in C. canadensis as compared to the other two species (C. sumatrensis > C. bonariensis > C. canadensis). Combined, all of the studied parameters identified differential susceptibility to glyphosate among the Conyza species. Each species accumulated shikimate in leaf tissues following application of glyphosate at 200 g ai ha(-1). However, C. canadensis exhibited lower shikimate levels than the other two species at 168 h after herbicide application. For hairy fleabane, a greenhouse study explored its susceptibility to glyphosate at three developmental stages: rosette, bolting (stem height, 10-15 cm), and flowering. The ED(50) was lower at the rosette stage (15.7 g ai ha(-1)) as compared to

  1. Freshwater Plants Synthesize Sulfated Polysaccharides: Heterogalactans from Water Hyacinth (Eicchornia crassipes)

    PubMed Central

    Dantas-Santos, Nednaldo; Gomes, Dayanne Lopes; Costa, Leandro Silva; Cordeiro, Sara Lima; Costa, Mariana Santos Santana Pereira; Trindade, Edvaldo Silva; Franco, Célia Regina Chavichiolo; Scortecci, Kátia Castanho; Leite, Edda Lisboa; Rocha, Hugo Alexandre Oliveira

    2012-01-01

    Sulfated polysaccharides (SP) are found mainly in seaweeds and animals. To date, they have only been found in six plants and all inhabit saline environments. Furthermore, there are no reports of SP in freshwater or terrestrial plants. As such, this study investigated the presence of SP in freshwaters Eichhornia crassipes, Egeria densa, Egeria naja, Cabomba caroliniana, Hydrocotyle bonariensis and Nymphaea ampla. Chemical analysis identified sulfate in N. ampla, H. bonariensis and, more specifically, E. crassipes. In addition, chemical analysis, FT-IR spectroscopy, histological analysis, scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDXA), as well as agarose gel electrophoresis detected SP in all parts of E. crassipes, primarily in the root (epidermis and vascular bundle). Galactose, glucose and arabinose are the main monosaccharides found in the sulfated polysaccharides from E. crassipes. In activated partial thromboplastin time (APTT) test, to evaluate the intrinsic coagulation pathway, SP from the root and rhizome prolonged the coagulation time to double the baseline value, with 0.1 mg/mL and 0.15 mg/mL, respectively. However, SP from the leaf and petiole showed no anticoagulant activity. Eichornia SP demonstrated promising anticoagulant potential and have been selected for further studies on bioguided fractionation; isolation and characterization of pure polysaccharides from this species. Additionally in vivo experiments are needed and are already underway. PMID:22312297

  2. Effect of ELMs on deuterium-loaded-tungsten plasma facing components

    NASA Astrophysics Data System (ADS)

    Umstadter, K. R.; Rudakov, D. L.; Wampler, W.; Watkins, J. G.; Wong, C. P. C.

    2011-08-01

    Prior heat pulse testing of plasma facing components (PFCs) has been completed in vacuum environments without the presence of background plasma. Edge localized modes (ELMs) will not be this kind of isolated event and one should know the effect of a plasma background during these transients. Heat-pulse experiments have been conducted in the PISCES-A device utilizing laser heating in a divertor-like plasma background. Initial results indicate that the erosion of PFCs is enhanced as compared to heat pulse or plasma only tests. To determine if the enhanced erosion effect is a phenomena only witnessed in the laboratory PISCES device, tungsten and graphite samples were exposed to plasmas in the lower divertor of the DIII-D tokamak using the Divertor Material Evaluation System (DiMES). Mass loss analysis indicates that materials that contain significant deuterium prior to experiencing a transient heating event will erode faster than those that have no or little retained deuterium.

  3. Star of Bethlehem

    NASA Astrophysics Data System (ADS)

    Hughes, D.; Murdin, P.

    2001-07-01

    The biblical Star of Bethlehem, which heralded the birth of Jesus Christ, is only mentioned in the Gospel of St Matthew 2. The astrologically significant 7 bc triple conjunction of Jupiter and Saturn in the constellation of Pisces is the most likely candidate, although a comet/nova in 5 bc and a comet in 4 bc cannot be ruled out. There is also the possibility that the star was simply fictitious....

  4. Aries

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    (the Ram; abbrev. Ari, gen. Arietis; area 441 sq. deg.) A northern zodiacal constellation that lies between Taurus and Pisces, and culminates at midnight in late October. It represents the ram in Greek mythology whose golden fleece was the quest of Jason and the Argonauts. Its brightest stars were cataloged by Ptolemy (c. AD 100-175) in the Almagest. In Ptolemy's day the Sun was in Aries at the v...

  5. Impurity Transport in a Simulated Gas Target Divertor

    NASA Astrophysics Data System (ADS)

    Blush, L. M.; Luckhardt, S.; Seraydarian, R.; Whyte, D.; Conn, R. W.; Schmitz, L.

    1997-11-01

    Previous simulated gas target divertor experiments in the PISCES-A linear plasma device (n <= 3 × 10^19 m-3, kTe <= 20 eV) indicated enhanced impurity retention near the target in comparison to a high recycling divertor regime. A 1 1\\over2-D fluid modeling code suggested that impurities are impeded from transporting away from the target by friction with the neutral and ionized hydrogen. In recent experiments with a PISCES-A ``slot-type'' divertor configuration, we have implemented a spectroscopic detection system to measure the axial density profiles of several impurity charge states. Moreover, we envision adding two extended cylindrical baffles spanning a pumped vacuum section to achieve strong differential pumping. This arrangement will isolate the plasma source from the gas target region and allow us to seed the background hydrogen plasma with higher impurities concentrations and investigate a regime dominated by impurity radiation. In preliminary design experiments, PISCES-A was successfully operated with an electrically isolated, copper baffle (d=5 cm, l=33.5 cm) mounted to reduce the vacuum conductance between the source and target regions. This work supported by US-DoE contract DE-FG03-95ER-54301.

  6. Improving the parameters of a global ocean biogeochemical model via variational assimilation of in situ data at five time series stations

    NASA Astrophysics Data System (ADS)

    Kane, A.; Moulin, C.; Thiria, S.; Bopp, L.; Berrada, M.; Tagliabue, A.; CréPon, M.; Aumont, O.; Badran, F.

    2011-06-01

    The global ocean biogeochemical models that are used in order to assess the ocean role in the global carbon cycle and estimate the impact of the climate change on marine ecosystems are getting more and more sophisticated. They now often account for several phytoplankton functional types that play particular roles in marine food webs and the ocean carbon cycle. These phytoplankton functional types have specific physiological characteristics, which are usually poorly known and therefore add uncertainties to model results. Indeed, this evolution in model complexity is not accompanied by a similar increase in the number and diversity of in situ data sets necessary for model calibration and evaluation. Thus, it is of primary importance to develop new methods to improve model performance using existing biogeochemical data sets, despite their current limitations. In this paper, we have optimized 45 physiological parameters of the PISCES global model, using a variational optimal control method. In order to bypass a global 3-D ocean variational assimilation, which would require enormous computation and memory storage, we have simplified the estimation procedure by assimilating monthly climatological in situ observations at five contrasted oceanographic stations of the JGOFS program in a 1-D version of the PISCES model. We began by estimating the weight matrix in the cost function by using heuristic considerations. Then we used this matrix to estimate the 45 parameters of the 1-D version of the PISCES model by assimilating the different monthly profiles (observed profiles at the five stations) in the same variational procedure on a time window of 1 year. This set of optimized parameters was then used in the standard 3-D global PISCES version to perform a 500 year global simulation. The results of both the standard and the optimized versions of the model were compared to satellite-derived chlorophyll-a images, which are an independent and global data set, showing that our

  7. Mission Accomplished: Deep Submergence Science Routinely Supported Using Multiple Vehicles Throughout the Hawaii Undersea Research Laboratory's 2005 South Pacific Expedition

    NASA Astrophysics Data System (ADS)

    Kerby, T.; Smith, J. R.; Shackelford, R.; Wiltshire, J. C.; Malahoff, A.

    2005-12-01

    The Hawaii Undersea Research Laboratory (HURL) recently completed an internationally partnered 5-month, 14,500 nautical mile multiple leg expedition to the South Pacific that included 21 study sites in the waters of American Samoa, New Zealand, Tonga, and the U.S. Line Islands to commemorate its 25th anniversary of supporting deep submergence science in the Pacific Ocean. During this voyage, HURL successfully operated its two human occupied vehicles ( Pisces IV and Pisces V) each capable of diving to 2000 m from their support ship, the R/V Ka'imikai-o-Kanaloa ( KoK). In addition, a remotely operated vehicle ( RCV-150) with a nearly 1000-m depth limit was utilized alternately with the Pisces HOV's. The size and organized placement of these vehicles on the compact but efficiently run KoK (70-m length, 2000-tons displacement, 14 crew) allowed for deployment of a CTD rosette system and recovery of instrument package moorings during the same cruise leg. The Pisces submersibles are 20-ft long, 13-ton, 3-person vehicles with 7-10 hours duration, up to 350-lb payload capacities, and three forward looking viewports. The small size of the Pisces' relative to much larger deeper diving HOV's increases their agility, thus allowing maneuvering into more difficult sampling site terrain. The smaller package also facilitates rapid launch (8 min avg, stdev=1) and recovery (12 min avg, stdev=2) in heavier seas (up to sea state 5), as routinely experienced in the South Pacific during the austral winter. In addition to the enhanced safety aspect of having two compatible submersibles aboard, scientific efficiency has benefited by allowing the rotation of vehicles on extended deployments prior to battery servicing, thus maintaining an overall dive time average of 7.1 hr (stdev=1.52) for an average dive depth of 891 m (stdev=431) in 2005. Having the two fully operational submersibles also provides a contingency for equipment malfunction while on site that saved 7 dive days in 2005 alone

  8. Three new species and one new record of Campylaimus (Diplopeltidae, Nematoda) from Argentine coasts (Buenos Aires and Santa Cruz, Argentina).

    PubMed

    Villares, Gabriela; Martelli, Antonela; Russo, Virginia Lo; Pastor, Catalina

    2013-01-01

    Two new Campylaimus species from Arroyo Pareja, Buenos Aires province and one new species and one new record of Campylaimus from Puerto San Julián, Chubut province are described. The three species are characterized by the shape of the copulatory apparatus of the male and the presence of precloacal papillae. Campylaimus bonariensis sp. nov. has slender and arcuate spicules, with well-developed cephalization at the proximal end, tubular gubernaculum and three precloacal papillae; Campylaimus arcuatus sp. nov. has curved spicules, with well-developed cephalization at the proximal end, gubernaculum with dorso-caudally directed apophysis and five precloacal papillae; Campylaimus patagonicus sp. nov. has slender and arcuate spicules without proximal cephalization, gubernaculum with dorso-caudally directed apophysis and two precloacal papillae. An emended diagnosis of the genus Campylaimus and an identification key to species based on male characters are given. PMID:24698903

  9. Evaluation of anti-inflammatory activity of essential oils from two Asteraceae species.

    PubMed

    Souza, M C; Siani, A C; Ramos, M F S; Menezes-de-Lima, O Júnior; Henriques, M G M O

    2003-08-01

    The essential oils from two Asteraceae species, Porophyllum ruderale (PR) and Conyza bonariensis (CB) were screened for anti-inflammatory activity in the mouse model of pleurisy induced by zymosan (500 microg/cavity) and lipopolysaccharide (LPS) (250 ng/cavity). The main monoterpene constituents of each oil, beta-myrcene (in PR) and limonene (in CB), were tested in the LPS-induced pleurisy model and assayed also for immunoregulatory activity by measurement of the inhibition of NO and production of the cytokines, gamma-interferon and IL-4. The oils, when administered orally, were able to inhibit the LPS-induced inflammation including cell migration; with a similar effect being observed for pure limonene. Pure beta-myrcene and limonene were also effective in inhibiting production of nitric oxide at doses below the cytotoxicity of these monoterpenes. A significant inhibition of gamma-interferon and IL-4 production by limonene and beta-myrcene was also observed. PMID:12967039

  10. A new model for the global biogeochemical cycle of carbonyl sulfide - Part 1: Assessment of direct marine emissions with an oceanic general circulation and biogeochemistry model

    NASA Astrophysics Data System (ADS)

    Launois, T.; Belviso, S.; Bopp, L.; Fichot, C. G.; Peylin, P.

    2015-03-01

    The global budget of tropospheric carbonyl sulfide (OCS) is believed to be at equilibrium because background air concentrations have remained roughly stable over at least the last decade. Since the uptake of OCS by leaves (associated with photosynthesis) and soils have been revised significantly upwards recently, an equilibrated budget can only be obtained with a compensatory source of OCS. It has been assumed that the missing source of OCS comes from the low-latitude ocean, following the incident solar flux. The present work uses parameterizations of major production and removal processes of organic compounds in the NEMO-PISCES (Nucleus for European Modelling of the Ocean, Pelagic Interaction Scheme for Carbon and Ecosystem Studies) ocean general circulation and biogeochemistry model to assess the marine source of OCS. In addition, the OCS photo-production rates computed with the NEMO-PISCES model~were evaluated independently using the UV absorption coefficient of chromophoric dissolved organic matter (derived from satellite ocean color data) and apparent quantum yields available in the literature. Our simulations show global direct marine emissions of OCS in the range of 573-3997 GgS yr-1, depending mostly on the quantification of the absorption rate of chromophoric dissolved organic matter. The high estimates of that range are unlikely, as they correspond to a formulation that most likely overestimate photo-production process. Low and medium (813 GgS yr-1) estimates derived from the NEMO-PISCES model are however consistent spatially and temporally~with the suggested missing source of Berry et al. (2013), allowing us thus to close the global budget of OCS given the recent estimates of leaf and soil OCS uptake.

  11. A new model for the global biogeochemical cycle of carbonyl sulfide - Part 1: Assessment of direct marine emissions with an oceanic general circulation and biogeochemistry model

    NASA Astrophysics Data System (ADS)

    Launois, T.; Belviso, S.; Bopp, L.; Fichot, C. G.; Peylin, P.

    2014-08-01

    The global budget of tropospheric carbonyl sulfide (OCS) is believed to be at equilibrium because background air concentrations have remained roughly stable over at least the last decade. Since the uptakes of OCS by leaves (associated to photosynthesis) and soils have been revised significantly upwards recently, an equilibrated budget can only be obtained with a compensatory source of OCS. It has been assumed that the missing source of OCS comes from the low latitude ocean, following the incident solar flux. The present work uses parameterizations of major production and removal processes of organic compounds in the NEMO-PISCES Ocean General Circulation and Biogeochemistry Model to assess the marine source of OCS. In addition, the OCS photo-production rates computed with the NEMO-PISCES model were evaluated independently using UV absorption coefficient of chromophoric dissolved organic matter (derived from satellite ocean color) and apparent quantum yields available in the literature. Our simulations show global direct marine emissions of COS in the range of 573-3997 Gg S yr-1, depending mostly on the quantification of the absorption rate of chromophoric dissolved organic matter. The high estimates on that range are unlikely, as they correspond to a formulation that most likely overestimate photo-production process. Low and medium (813 Gg S yr-1) estimates derived from the NEMO-PISCES model are however consistent spatially and temporally with the suggested missing source of Berry et al. (2013), allowing thus to close the global budget of OCS given the recent estimates of leaf and soil OCS uptakes.

  12. Sediment quality and polychlorinated biphenyls in the Lower Neponset River, Massachusetts, and implications for urban river restoration

    USGS Publications Warehouse

    Breault, Robert F.; Cooke, Matthew G.; Merrill, Michael

    2004-01-01

    Efforts to restore fish passage, habitat, and recreational use of the Neponset River, a tributary to Boston Harbor, Massachusetts, have raised concerns about the sediment, water, and biota quality of the river. Consequently, the U.S. Geological Survey, in cooperation with the Massachusetts Executive Office of Environmental Affairs Department of Fish and Game Riverways Program and the U.S. Environmental Protection Agency, studied sediment and water quality, with a specific focus on polychlorinated biphenyls, in the Neponset River. Sediment samples were collected throughout the Neponset River and tested for elements and organic compounds including polyaromatic hydrocarbons, organochlorine pesticides, and polychlorinated biphenyls. Although enriched compared to background concentrations, sediment quality in the Neponset River was generally better than that of other urban rivers in the United States, except with respect to one constituent, polychlorinated biphenyls. Concentrations of lead, some polyaromatic hydrocarbons, and polychlorinated biphenyls in the sediment may be toxic to aquatic organisms and may pose a risk to human health. The sediment quality also fails to meet the minimum requirements set by the Commonwealth of Massachusetts for lined landfill disposal. The locations of the source(s) of polychlorinated biphenyls to the Neponset River were determined by means of congener analysis from PISCES passive water-column samplers. The PISCES data indicate a sharp increase in polychlorinated biphenyl concentrations and a substantial shift in congener pattern downstream of one PISCES sampling location near Fairmont Avenue, Boston, Massachusetts. This result indicates that the area upstream of this sampling location may be the location of a historical source of polychlorinated biphenyls to the Neponset River. The present (2003) source to the water column may likely be PCB contaminated sediment.

  13. Technical performance of percutaneous leads for spinal cord stimulation: a modeling study.

    PubMed

    Manola, Ljubomir; Holsheimer, Jan; Veltink, Peter

    2005-04-01

    Objective  To compare the technical performance of different percutaneous lead types for spinal cord stimulation. Methods  Using the ut-scs software (University of Twente's spinal cord stimulation), lead models having similar characteristics such as the 3487A PISCES-Quad (PQ), 3887 PISCES-Quad Compact (PC), 3888 PISCES-Quad Plus (PP) (Medtronic Inc., Minneapolis, MN), and the AB SC2108 (AB) (Advanced Bionics Corp., Valencia, CA) were simulated in monopolar and tripolar (guarded cathode) combinations on a single lead, placed just outside the dorsal dura mater and both centered on the spinal cord midline, and at 1 mm lateral. The influence of displacing a lead dorsally in the epidural fat was examined as well. Finally, dual leads both aligned and offset were modeled. Several parameters were calculated to allow a quantitative comparison of the performances. Results  When programmed as a guarded cathode, the AB lead recruits nerve fibers in an ~25% larger dorsal column area than the PQ. However, the AB has an ~160% higher energy consumption. The performance of the PC is between the AB and PQ, whereas the PP is suitable only for dorsal root stimulation. Displacing a single lead off midline or dorsally decreases its ability to recruit fibers in the dorsal columns. Similarly, dual lead combinations are less capable when compared to single lead centered on the spinal cord midline just outside the dura mater. Conclusions  Complex pain syndromes are treated best with lead having a small contact spacing, being programmed as a tripole (guarded cathode) and centered on the spinal cord midline just outside the dura mater. This is because dorsal column fiber recruitment is more extensive than with any other combinations, including dual leads. Improved recruitment of dorsal column fibers is accompanied by increased energy consumption. PMID:22151437

  14. Proteome scale characterization of human S-acylated proteins in lipid raft-enriched and non-raft membranes.

    PubMed

    Yang, Wei; Di Vizio, Dolores; Kirchner, Marc; Steen, Hanno; Freeman, Michael R

    2010-01-01

    Protein S-acylation (palmitoylation), a reversible post-translational modification, is critically involved in regulating protein subcellular localization, activity, stability, and multimeric complex assembly. However, proteome scale characterization of S-acylation has lagged far behind that of phosphorylation, and global analysis of the localization of S-acylated proteins within different membrane domains has not been reported. Here we describe a novel proteomics approach, designated palmitoyl protein identification and site characterization (PalmPISC), for proteome scale enrichment and characterization of S-acylated proteins extracted from lipid raft-enriched and non-raft membranes. In combination with label-free spectral counting quantitation, PalmPISC led to the identification of 67 known and 331 novel candidate S-acylated proteins as well as the localization of 25 known and 143 novel candidate S-acylation sites. Palmitoyl acyltransferases DHHC5, DHHC6, and DHHC8 appear to be S-acylated on three cysteine residues within a novel CCX(7-13)C(S/T) motif downstream of a conserved Asp-His-His-Cys cysteine-rich domain, which may be a potential mechanism for regulating acyltransferase specificity and/or activity. S-Acylation may tether cytoplasmic acyl-protein thioesterase-1 to membranes, thus facilitating its interaction with and deacylation of membrane-associated S-acylated proteins. Our findings also suggest that certain ribosomal proteins may be targeted to lipid rafts via S-acylation, possibly to facilitate regulation of ribosomal protein activity and/or dynamic synthesis of lipid raft proteins in situ. In addition, bioinformatics analysis suggested that S-acylated proteins are highly enriched within core complexes of caveolae and tetraspanin-enriched microdomains, both cholesterol-rich membrane structures. The PalmPISC approach and the large scale human S-acylated protein data set are expected to provide powerful tools to facilitate our understanding of the

  15. The Independent Technical Analysis Process Final Report 2006-2007.

    SciTech Connect

    Duberstein, Corey; Ham, Kenneth; Dauble, Dennis; Johnson, Gary

    2007-03-01

    The Bonneville Power Administration (BPA) contracted with the Pacific Northwest National Laboratory (PNNL) to provide technical analytical support for system-wide fish passage information (BPA Project No. 2006-010-00). The goal of this project was to produce rigorous technical analysis products using independent analysts and anonymous peer reviewers. This project provided an independent technical source for non-routine fish passage analyses while allowing routine support functions to be performed by other well-qualified entities. The Independent Technical Analysis Process (ITAP) was created to provide non-routine analysis for fish and wildlife agencies and tribes in particular and the public in general on matters related to juvenile and adult salmon and steelhead passage through the mainstem hydrosystem. The process was designed to maintain the independence of analysts and reviewers from parties requesting analyses, to avoid potential bias in technical products. The objectives identified for this project were to administer a rigorous, transparent process to deliver unbiased technical assistance necessary to coordinate recommendations for storage reservoir and river operations that avoid potential conflicts between anadromous and resident fish. Seven work elements, designated by numbered categories in the Pisces project tracking system, were created to define and accomplish project goals as follows: (1) 118 Coordination - Coordinate technical analysis and review process: (a) Retain expertise for analyst/reviewer roles. (b) Draft research directives. (c) Send directive to the analyst. (d) Coordinate two independent reviews of the draft report. (e) Ensure reviewer comments are addressed within the final report. (2) 162 Analyze/Interpret Data - Implement the independent aspects of the project. (3) 122 Provide Technical Review - Implement the review process for the analysts. (4) 132 Produce Annual Report - FY06 annual progress report with Pisces Disseminate (5) 161

  16. Simulating Fertilization of the Ocean as a Carbon Sequestration Strategy: Effectiveness and Unintended Consequences

    SciTech Connect

    Caldeira, K

    2002-03-20

    The primary objectives of this project are to assess, and improve our understanding of: (1) The effectiveness of various strategies to intentionally store carbon in the ocean through fertilization of the surface ocean with iron and/or macronutrients; and (2) Unanticipated environmental consequences of these ocean fertilization strategies. We propose to use what may be the best global ocean biogeochemical model in the world (PISCES) and apply it to perform the most realistic global-scale simulations of various iron fertilization scenarios. Versions of PISCES are currently used by MPI in Germany and IPSL in France. The model represents diatoms, coccolithophorids, and two classes of zooplankton. This model considers Fey N, P, O{sub 2}, Si, alkalinity, and carbon; for some of these it considers dissolved inorganic and organic, as well as particulate, forms. We would install the PISCES model with a minimum of modification into the LLNL ocean model, and perform an initial suite of simulations of both iron fertilization experiments (e.g., SOFeX) and proposed iron fertilization strategies. Based on the simulated experiments, we will analyze model deficiencies with respect to the observations and use this analysis to improve future versions of the model. The source code for and results from this set of models will be freely distributed, and thus should help groups performing related work elsewhere. This project the most-realistic ocean fertilization simulations yet performed in a global model, with an assessment of and improvement in the reliability of those predictions using results from iron fertilization experiments such as SOFeX. These results will help provide context and guidance for biological observations within the ocean carbon sequestration research program.

  17. Rock wall fauna in a deep Newfoundland fiord

    NASA Astrophysics Data System (ADS)

    Haedrich, Richard L.; Gagnon, Jean-Marc

    1991-08-01

    Research dives with PISCES IV in the Bay D'Espoir fiord system of southern Newfoundland revealed a rich and abundant fauna inhabiting the rock walls in the warm deep (790 m) central basin. The giant file clam Acesta excavata, otherwise unknown in the western North Atlantic, was in many places a dominant species. Species otherwise known from continental slope depths quite removed from the fiord included the anemone Actinauge sp., sponges, alcyonarians, the fish Phycis chesteri and Nezumia bairdii and the gooseneck barnacle Arcoscalpellum mitchellotianum. The food source for this abundant fauna is unknown. Nearby cold water basins are impoverished with respect to the fauna.

  18. Research in computer science

    NASA Technical Reports Server (NTRS)

    Ortega, J. M.

    1984-01-01

    Several short summaries of the work performed during this reporting period are presented. Topics discussed in this document include: (1) resilient seeded errors via simple techniques; (2) knowledge representation for engineering design; (3) analysis of faults in a multiversion software experiment; (4) implementation of parallel programming environment; (5) symbolic execution of concurrent programs; (6) two computer graphics systems for visualization of pressure distribution and convective density particles; (7) design of a source code management system; (8) vectorizing incomplete conjugate gradient on the Cyber 203/205; (9) extensions of domain testing theory and; (10) performance analyzer for the pisces system.

  19. The Church of San Miniato al Monte, Florence: Astronomical and Astrological Connections

    NASA Astrophysics Data System (ADS)

    Shrimplin, V.

    2011-06-01

    The church of San Miniato al Monte is examined in the context of interest in astrology and astronomy in early Renaissance Florence. Vitruvius emphasised the need for architects to "be acquainted with astronomy and the theory of the heavens" in his famous Ten Books of Architecture and, at San Miniato, astronomical and astrological features are combined in order to link humanity with the celestial or spiritual realm. The particular significance of Pisces and Taurus is explored in relation to Christian symbolism, raising questions about the role of astronomy and astrology in art and architecture.

  20. Sea floor gouges and pits in deep fjords, Baffin Island: Possible mammalian feeding traces

    NASA Astrophysics Data System (ADS)

    Hein, F. J.; Syvitski, J. P. M.

    1989-06-01

    Pisces submersible dives within Baffin Island fjords have revealed the common occurrence of pits on the sea floor, at water depths between 40 and 326 m. The size of these pits are in the decimeter to meter range. Through indirect evidence (by comparison of morphologic features to pits or gouges of known origin) they are believed to be feeding traces of narwhal, beluga, or bowhead whales. If so, they are the deepest mammalian feeding traces yet reported. Bioerosion by large foraging mammals may be a more common sea floor process than previously thought.

  1. Calculation of rf fields in axisymmetric cavities

    SciTech Connect

    Iwashita, Y.

    1985-01-01

    A new code, PISCES, has been developed for calculating a complete set of rf electromagnetic modes in an axisymmetric cavity. The finite-element method is used with up to third-order shape functions. Although two components are enough to express these modes, three components are used as unknown variables to take advantage of the symmetry of the element matrix. The unknowns are taken to be either the electric field components or the magnetic field components. The zero-divergence condition will be satisfied by the shape function within each element.

  2. Response of the GPHS/RTG system to potential launch accident environments

    NASA Astrophysics Data System (ADS)

    Mukunda, Meera

    1998-01-01

    The Cassini spacecraft is designed to carry out an orbital tour of the Saturnian system and an investigation of the planet, its satellites, atmosphere, and its ring system. The space vehicle is powered by three Radioisotope Thermoelectric Generators (RTGs) which are mounted normal to the thrust axis of the vehicle. The nuclear heat source for each RTG consists of a stacked column of eighteen General Purpose Heat Source (GPHS) modules. Each module primarily consists of an aeroshell, two Graphite Impact Shells (GIS), and four Fueled Clads (FC). Each FC consists of a fuel pellet of plutonium-238 in the form of the oxide PuO2 encased in an iridium shell which serves to contain the fuel. An extensive program of experimental tests and analyses was conducted in support of previous missions (Galileo and Ulysses) which served to calibrate and validate the PISCES 2D-ELK continuum mechanics code. This paper describes the response of the GPHS-RTG system to a large number of potential launch accident environments employing the MSC/PISCES Euler Lagrange shell coupled hydrocode as an analytical tool. The results of these calculations quantified the integrity of the iridium clad fuel containment system and provided a data base for a determination of the overall risk for the Cassini mission by others.

  3. Codon usage trend in mitochondrial CYB gene.

    PubMed

    Uddin, Arif; Chakraborty, Supriyo

    2016-07-15

    Here we reported the pattern of codon usage and the factors which influenced the codon usage pattern in mitochondrial cytochrome B (MT-CYB) gene among pisces, aves and mammals. The F1 axis of correspondence analysis showed highly significant positive correlation with nucleobases A3, C and C3 and significant negative correlation with T and T3 while F2 of correspondence analysis showed significant positive correlation with C and C3 and significant negative correlation with A and A3. From the neutrality plot, it was evident that the GC12 was influenced by mutation pressure and natural selection with a ratio of 0.10/0.90=0.11 in pisces, 0.024/0.976=0.0245 in aves and in mammals 0.215/0.785=0.273, which indicated that the role of natural selection was more than mutation pressure on structuring the bases at the first and second codon positions. Natural selection played the major role; but compositional constraint and mutation pressure also played a significant role in codon usage pattern. Analysis of codon usage pattern has contributed to the better understanding of the mechanism of distribution of codons and the evolution of MT-CYB gene. PMID:27063508

  4. Simulating the growth and distribution of planktic foraminifer using an ecophysiological multi-species model

    NASA Astrophysics Data System (ADS)

    Lombard, F.; Labeyrie, L.; Michel, E.; Bopp, L.; Cortijo, E.; Retailleau, S.; Howa, H.; Jorissen, F.

    2011-01-01

    We present an eco-physiological model reproducing the growth of eight foraminifer species (Neogloboquadrina pachyderma, Neogloboquadrina incompta, Neogloboquadrina dutertrei, Globigerina bulloides, Globigerinoides ruber, Globigerinoides sacculifer, Globigerinella siphonifera and Orbulina universa). By using the main physiological rates of foraminifers (nutrition, respiration, symbiotic photosynthesis), this model estimates their growth as a function of temperature, light availability, and food concentration. Model parameters are directly derived or calibrated from experimental observations and only the influence of food concentration (estimated via chl-a concentration) was calibrated against field observations. Growth rates estimated from the model show positive correlation with observed abundance from plankton net data suggesting close coupling between individual and assemblage growth rates. This observation was used to directly estimate potential abundance from the model-derived growth. Using satellite data, the model simulate the dominant foraminifer with a 70.5% efficiency when compared to a data set of 576 field observations worldwide. Using outputs of a biogeochemical model of the global ocean (PISCES) instead of satellite images as forcing variables gives also good results, but with lower efficiency (58.9%). The model also correctly reproduces the relative worldwide abundance and the diversity of the eight species when compared to core tops observations both using satellite and PISCES data. This model allows prediction of the season and water depth at which each species has its highest growth potential. This offers promising perspectives for both an improved quantification of paleoceanographic reconstructions and for a better understanding of the foraminiferal role in the marine carbon cycle.

  5. Modelling planktic foraminifer growth and distribution using an ecophysiological multi-species approach

    NASA Astrophysics Data System (ADS)

    Lombard, F.; Labeyrie, L.; Michel, E.; Bopp, L.; Cortijo, E.; Retailleau, S.; Howa, H.; Jorissen, F.

    2011-04-01

    We present an eco-physiological model reproducing the growth of eight foraminifer species (Neogloboquadrina pachyderma, Neogloboquadrina incompta, Neogloboquadrina dutertrei, Globigerina bulloides, Globigerinoides ruber, Globigerinoides sacculifer, Globigerinella siphonifera and Orbulina universa). By using the main physiological rates of foraminifers (nutrition, respiration, symbiotic photosynthesis), this model estimates their growth as a function of temperature, light availability, and food concentration. Model parameters are directly derived or calibrated from experimental observations and only the influence of food concentration (estimated via Chlorophyll-a concentration) was calibrated against field observations. Growth rates estimated from the model show positive correlation with observed abundance from plankton net data suggesting close coupling between individual growth and population abundance. This observation was used to directly estimate potential abundance from the model-derived growth. Using satellite data, the model simulate the dominant foraminifer species with a 70.5% efficiency when compared to a data set of 576 field observations worldwide. Using outputs of a biogeochemical model of the global ocean (PISCES) instead of satellite images as forcing variables gives also good results, but with lower efficiency (58.9%). Compared to core tops observations, the model also correctly reproduces the relative worldwide abundance and the diversity of the eight species when using either satellite data either PISCES results. This model allows prediction of the season and water depth at which each species has its maximum abundance potential. This offers promising perspectives for both an improved quantification of paleoceanographic reconstructions and for a better understanding of the foraminiferal role in the marine carbon cycle.

  6. Investigation of He–W interactions using DiMES on DIII-D

    DOE PAGESBeta

    Doerner, R. P.; Rudakov, D. L.; Chrobak, C. P.; Briesemeister, A. R.; Corr, C.; De Temmerman, G.; Kluth, P.; Lasnier, C. J.; McLean, A. G.; Pace, D. C.; et al

    2016-01-22

    Here, tungsten button samples were exposed to He ELMing H-mode plasma in DIII-D using 2.3 MW of electron cyclotron heating power. Prior to the exposures, the W buttons were exposed to either He, or D, plasma in PISCES-A for 2000 s at surface temperatures of 225–850 °C to create a variety of surfaces (surface blisters, subsurface nano-bubbles, fuzz). Erosion was spectroscopically measured from each DiMES sample, with the exception of the fuzzy W samples which showed almost undetectable WI emission. Post-exposure grazing incidence small angle x-ray scattering surface analysis showed the formation of 1.5 nm diameter He bubbles in themore » surface of W buttons after only a single DIII-D (3 s, ~150 ELMs) discharge, similar to the bubble layer resulting from the 2000 s. exposure in PISCES-A. No surface roughening, or damage, was detected on the samples after approximately 600 ELMs with energy density between 0.04–0.1 MJ m–2.« less

  7. Closing the carbon cycle in the EC EARTH earth system model

    NASA Astrophysics Data System (ADS)

    Gröger, Matthias; Döscher, Ralf; Meier, Markus; Svensson, Gunilla

    2015-04-01

    A closed carbon cycle, i.e. the exchange of carbon fluxes between the terrestrial and marine carbon reservoirs (living biomass, soil carbon, sediments etc) via the atmosphere is essential for state of the art earth system models and it will become more and more important in the framework of the Coupled Model Intercomparison Project (CMIP). It is also a prerequisite for simulating the atmospheric pCO2 in a fully prognostic mode and thus, for the realistic simulation of the important feedback of the carbon cycle to the predicted future climate change. The main challenges of this work are two fold: It requires close cooperation between physical oceanographers, meteorologists and biogeochemists. Moreover, especially the marine carbon cycle has very long internal time scales which demand for long spinup phases. The work presented here is the result of the joined efforts of the Meteorological Institute University of Stockholm, the Rossby Center for Climatic Research and the oceanographic department of the Swedish Meteorological and Hydrological Institute (SMHI), and the University of Lund. We here introduce our basic strategy for the implementation of the marine biogeochemistry model PISCES into EC Earth and first results for the marine carbon cycle model PISCES are presented.

  8. Beryllium deposition on International Thermonuclear Experimental Reactor first mirrors: Layer morphology and influence on mirror reflectivity

    NASA Astrophysics Data System (ADS)

    De Temmerman, G.; Baldwin, M. J.; Doerner, R. P.; Nishijima, D.; Seraydarian, R.; Schmid, K.; Kost, F.; Linsmeier, Ch.; Marot, L.

    2007-10-01

    Metallic mirrors will be essential components of the optical diagnostic systems in the International Thermonuclear Experimental Reactor (ITER). Reliability of these systems may be affected by mirror reflectivity changes induced by erosion and/or deposition of impurities (carbon, beryllium). The present study aims to assess the effect of beryllium (Be) deposition on the reflectivity of metallic mirrors and to collect data on the optical quality of these layers in terms of morphology, roughness, etc. Mirrors from molybdenum and copper were exposed in the PISCES-B linear plasma device to collect eroded material from graphite and beryllium targets exposed to beryllium-seeded deuterium plasma. After exposure, relative reflectivity of the mirrors was measured and different surface analysis techniques were used to investigate the properties of the deposited layers. Be layers formed in PISCES-B exhibit high levels of porosity which makes the reflectivity of the Be layers much lower than the reflectivity of pure Be. It is found that if Be deposition occurs on ITER first mirrors, the reflectivity of the coated mirrors will strongly depend on the layer morphology, which in turn depends on the deposition conditions.

  9. Shillapoo Wildlife Area, Annual Report 2004-2005.

    SciTech Connect

    Calkins, Brian

    2004-10-01

    This report summarizes accomplishments, challenges and successes on WDFW's Shillapoo Wildlife Area funded under Bonneville Power Administration's (BPA) Wildlife Mitigation Program (BPA project No.2003-012-00) during the Fiscal Year 05 contract period October 1, 2004-September 30, 2005. The information presented here is intended to supplement that contained in BPA's PISCES contract development and reporting system. The organization below is by broad categories of work but references are made to individual work elements in the PISCES Statement of Work as appropriate. The greatest success realized during this contract period was completion of the water system that will provide water to wetland basins within the Vancouver Lake Unit and three independent basins on adjoining Clark County owned lands. The water system paid for by Clark Public Utilities was designed and built under the direction of Ducks Unlimited. Having a reliable water supply for these areas has allowed us for the first time to begin making significant progress toward our wetland vegetation management goals on this unit. A reduction in the density of reed canary grass has already been noted and increased levels of native plant occurrence have been observed. Our most notable setback was an increase in the infestation of purple loosestrife within a portion of the Shillapoo Lakebed including parts of the North and South Units. A great deal of effort and time was spent on addressing the problem including hand cutting and spraying individual plants.

  10. Coeur d'Alene Tribe Fisheries Program : Implementation of Fisheries Enhancement Opportunities on the Coeur d'Alene Reservation : 2006 Annual Report.

    SciTech Connect

    Vitale, Angelo J.; Hallock, Stephanie A.; Firehammer, Jon A.

    2008-12-12

    This annual report summarizes previously unreported data collected to fulfill the contractual obligations for BPA project No.1990-044-00, 'Coeur d'Alene Subbasin Fisheries Habitat Enhancement', during the 2006 calendar year. Even though the contract performance period for this project crosses fiscal and calendar years, the timing of data collection and analysis, as well as implementation of restoration projects, lends itself to this reporting schedule. The 2006 performance period marked the first year that BPA implemented its Process Improvement Initiative with the Pisces system serving as the vehicle for developing statements of work and tracking project performance. This document attempts to provide some consistency between the project objectives, around which past reports have been structured, and the new work element format adopted for use in Pisces. The report is formatted into three primary sections that respectively provide results and discussion of: (1) monitoring and evaluation of biological and physical habitat indicators; (2) implementation of restoration and enhancement projects; and (3) education and outreach work performed during 2006. The relevant work elements and/or milestones found in the statement of work are listed under these section headings and described in the body of the report.

  11. Investigation of He-W interactions using DiMES on DIII-D

    NASA Astrophysics Data System (ADS)

    Doerner, R. P.; Rudakov, D. L.; Chrobak, C. P.; Briesemeister, A. R.; Corr, C.; De Temmerman, G.; Kluth, P.; Lasnier, C. J.; McLean, A. G.; Pace, D. C.; Pitts, R. A.; Schmitz, O.; Thompson, M.; Winters, V.

    2016-02-01

    Tungsten button samples were exposed to He ELMing H-mode plasma in DIII-D using 2.3 MW of electron cyclotron heating power. Prior to the exposures, the W buttons were exposed to either He, or D, plasma in PISCES-A for 2000 s at surface temperatures of 225-850 °C to create a variety of surfaces (surface blisters, subsurface nano-bubbles, fuzz). Erosion was spectroscopically measured from each DiMES sample, with the exception of the fuzzy W samples which showed almost undetectable WI emission. Post-exposure grazing incidence small angle x-ray scattering surface analysis showed the formation of 1.5 nm diameter He bubbles in the surface of W buttons after only a single DIII-D (3 s, ˜150 ELMs) discharge, similar to the bubble layer resulting from the 2000 s. exposure in PISCES-A. No surface roughening, or damage, was detected on the samples after approximately 600 ELMs with energy density between 0.04-0.1 MJ m-2.

  12. The Arrowhead Mini-supercluster of Galaxies

    NASA Astrophysics Data System (ADS)

    Pomarède, Daniel; Tully, R. Brent; Hoffman, Yehuda; Courtois, Hélène M.

    2015-10-01

    Superclusters of galaxies can be defined kinematically from local evaluations of the velocity shear tensor. The location where the smallest eigenvalue of the shear is positive and maximal defines the center of a basin of attraction. Velocity and density fields are reconstructed with Wiener Filter techniques. Local velocities due to the density field in a restricted region can be separated from external tidal flows, permitting the identification of boundaries separating inward flows toward a basin of attraction and outward flows. This methodology was used to define the Laniakea Supercluster that includes the Milky Way. Large adjacent structures include Perseus-Pisces, Coma, Hercules, and Shapley but current kinematic data are insufficient to capture their full domains. However, there is a small region trapped between Laniakea, Perseus-Pisces, and Coma that is close enough to be reliably characterized and that satisfies the kinematic definition of a supercluster. Because of its shape, it is given the name the Arrowhead Supercluster. This entity does not contain any major clusters. A characteristic dimension is ˜25 Mpc and the contained mass is only ˜ {10}15 {M}⊙ .

  13. Apparent Acquired Resistance by a Weevil to Its Parasitoid Is Influenced by Host Plant.

    PubMed

    Goldson, Stephen L; Tomasetto, Federico

    2016-01-01

    Field parasitism rates of the Argentine stem weevil Listronotus bonariensis (Kuschel; Coleoptera: Curculionidae) by Microctonus hyperodae Loan (Hymenoptera: Braconidae) are known to vary according to different host Lolium species that also differ in ploidy. To further investigate this, a laboratory study was conducted to examine parasitism rates on tetraploid Italian Lolium multiflorum, diploid Lolium perenne and diploid hybrid L. perenne ×L. multiflorum; none of which were infected by Epichloë endophyte. At the same time, the opportunity was taken to compare the results of this study with observations made during extensive laboratory-based research and parasitoid-rearing in the 1990s using the same host plant species. This made it possible to determine whether there has been any change in weevil susceptibility to the parasitoid over a 20 year period when in the presence of the tetraploid Italian, diploid perennial and hybrid host grasses that were commonly in use in the 1990's. The incidence of parasitism in cages, in the presence of these three grasses mirrored what has recently been observed in the field. When caged, weevil parasitism rates in the presence of a tetraploid Italian ryegrass host were significantly higher (75%) than rates that occurred in the presence of either the diploid perennial (46%) or the diploid hybrid (52%) grass, which were not significantly different from each other. This is very different to laboratory parasitism rates in the 1990s when in the presence of both of the latter grasses high rates of parasitism (c. 75%) were recorded. These high rates are typical of those still found in weevils in the presence of both field and caged tetraploid Italian grasses. In contrast, the abrupt decline in weevil parasitism rates points to the possibility of evolved resistance by the weevil to the parasitoid in the diploid and hybrid grasses, but not so in the tetraploid. The orientation of plants in the laboratory cages had no significant effect on

  14. Apparent Acquired Resistance by a Weevil to Its Parasitoid Is Influenced by Host Plant

    PubMed Central

    Goldson, Stephen L.; Tomasetto, Federico

    2016-01-01

    Field parasitism rates of the Argentine stem weevil Listronotus bonariensis (Kuschel; Coleoptera: Curculionidae) by Microctonus hyperodae Loan (Hymenoptera: Braconidae) are known to vary according to different host Lolium species that also differ in ploidy. To further investigate this, a laboratory study was conducted to examine parasitism rates on tetraploid Italian Lolium multiflorum, diploid Lolium perenne and diploid hybrid L. perenne ×L. multiflorum; none of which were infected by Epichloë endophyte. At the same time, the opportunity was taken to compare the results of this study with observations made during extensive laboratory-based research and parasitoid-rearing in the 1990s using the same host plant species. This made it possible to determine whether there has been any change in weevil susceptibility to the parasitoid over a 20 year period when in the presence of the tetraploid Italian, diploid perennial and hybrid host grasses that were commonly in use in the 1990’s. The incidence of parasitism in cages, in the presence of these three grasses mirrored what has recently been observed in the field. When caged, weevil parasitism rates in the presence of a tetraploid Italian ryegrass host were significantly higher (75%) than rates that occurred in the presence of either the diploid perennial (46%) or the diploid hybrid (52%) grass, which were not significantly different from each other. This is very different to laboratory parasitism rates in the 1990s when in the presence of both of the latter grasses high rates of parasitism (c. 75%) were recorded. These high rates are typical of those still found in weevils in the presence of both field and caged tetraploid Italian grasses. In contrast, the abrupt decline in weevil parasitism rates points to the possibility of evolved resistance by the weevil to the parasitoid in the diploid and hybrid grasses, but not so in the tetraploid. The orientation of plants in the laboratory cages had no significant effect

  15. Locating and Evaluating Sea-Disposed Munitions--Examples from the Hawaii Undersea Military Munitions Assessment (HUMMA) Project

    NASA Astrophysics Data System (ADS)

    Edwards, M.; Wilkens, R. H.; Kelley, C.; de Carlo, E. H.; MacDonald, K.; Garcia, S.; Vanwoerkom, M.; Payne, Z.; Dupra, V.; Rosete, M.; Cox, M.; Fineran, S.; King, J. C.; Carton, G.

    2009-12-01

    The Army, under its Environmental Quality Technology (EQT) Program funded the HUMMA Project to assess the location of, and potential risk to human health posed by, sea disposed munitions (discarded military munitions (DMM)) at a study site south of Pearl Harbor, Hawai‘i known as HI-05. These conventional and chemical munitions are believed to have been exposed to undersea biochemical and mechanical erosion since the late 1940’s. To locate <2-meter long DMM at depths of 300-600 meters, we used a series of nested surveys beginning with an IMI-120 sidescan sonar survey of HI-05. From backscatter data gridded into 0.5-2m cells, we identified trails of highly reflective targets as candidate study sites. We initially surveyed these sites using a towed video camera. Subsequently, during a 12-day program aboard the R/V Kaimikai-o-Kanaloa, we surveyed selected targets using PISCES submersibles and an RCV-150 remotely operated vehicle operated by the Hawaii Undersea Research Lab. Every trail of reflective targets identified in the IMI-120 data was subsequently shown to contain DMM of various types. In combination with completing optical surveys to augment the IMI-120 acoustic data, the PISCES submersibles collected 96 sediment and 24 water samples within 1 and 2 meters of high-interest DMM as well as comparative background sites. The Edgewood Chemical and Biological Center supported dive operations to ensure crew personnel were not exposed to chemical agents (CA) and processed samples on board to determine if CA was present. The processed samples were then packaged and shipped to various shore-based laboratories to determine the presence of energetics and metals. Upon completion of the diving program, various species of locally consumed snapper and shrimp were collected near several of the sediment and water sample sites for analogous laboratory analyses. Our approach proved to be highly successful, identifying in a 5-day long IMI-120 survey the location of dozens of

  16. The Hawaii Undersea Research Laboratory's 25th Anniversary Expedition to the South Pacific

    NASA Astrophysics Data System (ADS)

    Smith, J. R.; Wiltshire, J. C.; Malahoff, A.

    2005-12-01

    The Hawaii Undersea Research Laboratory (HURL) was established by NOAA at the University of Hawaii 25 years ago as part of its National Undersea Research Program. HURL's mission is to study deep water marine processes in the Pacific Ocean through a competitive proposal and review process. The dual Pisces IV and Pisces V 2000-meter manned submersibles, an RCV-150 1000-meter ROV, and multibeam equipped support ship R/V Ka'imikai-o-Kanaloa ( KoK) were largely acquired from the petroleum industry then adapted and upgraded to carry out cutting edge scientific expeditions. These studies range from active submarine volcanoes, delicate precious coral gardens, endangered marine mammal and fisheries management, to engineering surveys and deployment of observatory systems. HURL successfully completed a major 5-month expedition to the South Pacific during March-August 2005, working in the waters of New Zealand, Tonga, American Samoa, and the U.S. Line Islands covering a distance of nearly 14,500 nautical miles. This mission was significant in both the scientific merit and scope of operations, consisting of 8 different cruise legs at 21 study sites, with 12 chief and co-chief scientists, 58 total science team participants, and completing 61 out of 56 scheduled Pisces science dives, 17 ROV dives, 5 multibeam survey areas, 6 CTD rosette deployments, and 7 instrument mooring recoveries. The $3.5 million expedition was funded by an international partnership with New Zealand agencies (GNS & NIWA) and the University of Kiel in Germany along with the NOAA Office of Exploration and National Undersea Research Program. While most of the individual cruise legs focused on active submarine volcanoes of the Tonga-Kermadec Islands Arc and the Samoan hot spot chain with their hydrothermal systems and associated biological communities, others concentrated on marine protected areas including those of American Samoa and the remote atolls of the Line Islands of the Central Pacific. These studies

  17. Formulated Beta-Cyfluthrin Shows Wide Divergence in Toxicity among Bird Species

    PubMed Central

    Addy-Orduna, Laura M.; Zaccagnini, María-Elena; Canavelli, Sonia B.; Mineau, Pierre

    2011-01-01

    It is generally assumed that the toxicity of pyrethroid insecticides to birds is negligible, though few species have been tested. The oral acute toxicity of formulated beta-cyfluthrin was determined for canaries (Serinus sp.), shiny cowbirds (Molothrus bonariensis), and eared doves (Zenaida auriculata). Single doses were administered to adults by gavage. Approximate lethal doses 50 (LD50) and their confidence intervals were determined by approximate D-optimal design. Canaries were found to be substantially more sensitive to formulated beta-cyfluthrin (LD50 = (170 ± 41) mg/kg) than the other two species tested (LD50 = (2234 ± 544) mg/kg and LD50 = (2271 ± 433) mg/kg, resp.). The LD50 obtained for canaries was also considerably lower than typical toxicity values available in the literature for pyrethroids. This study emphasizes the need for testing a broader range of species with potentially toxic insecticides, using modern up and down test designs with minimal numbers of birds. PMID:21584255

  18. Brood parasite eggs enhance egg survivorship in a multiply parasitized host

    PubMed Central

    Gloag, Ros; Fiorini, Vanina D.; Reboreda, Juan C.; Kacelnik, Alex

    2012-01-01

    Despite the costs to avian parents of rearing brood parasitic offspring, many species do not reject foreign eggs from their nests. We show that where multiple parasitism occurs, rejection itself can be costly, by increasing the risk of host egg loss during subsequent parasite attacks. Chalk-browed mockingbirds (Mimus saturninus) are heavily parasitized by shiny cowbirds (Molothrus bonariensis), which also puncture eggs in host nests. Mockingbirds struggle to prevent cowbirds puncturing and laying, but seldom remove cowbird eggs once laid. We filmed cowbird visits to nests with manipulated clutch compositions and found that mockingbird eggs were more likely to escape puncture the more cowbird eggs accompanied them in the clutch. A Monte Carlo simulation of this ‘dilution effect’, comparing virtual hosts that systematically either reject or accept parasite eggs, shows that acceptors enjoy higher egg survivorship than rejecters in host populations where multiple parasitism occurs. For mockingbirds or other hosts in which host nestlings fare well in parasitized broods, this benefit might be sufficient to offset the fitness cost of rearing parasite chicks, making egg acceptance evolutionarily stable. Thus, counterintuitively, high intensities of parasitism might decrease or even reverse selection pressure for host defence via egg rejection. PMID:22158956

  19. Sex differences in retention after a visual or a spatial discrimination learning task in brood parasitic shiny cowbirds.

    PubMed

    Astié, Andrea A; Scardamaglia, Romina C; Muzio, Rubén N; Reboreda, Juan C

    2015-10-01

    Females of avian brood parasites, like the shiny cowbird (Molothrus bonariensis), locate host nests and on subsequent days return to parasitize them. This ecological pressure for remembering the precise location of multiple host nests may have selected for superior spatial memory abilities. We tested the hypothesis that shiny cowbirds show sex differences in spatial memory abilities associated with sex differences in host nest searching behavior and relative hippocampus volume. We evaluated sex differences during acquisition, reversal and retention after extinction in a visual and a spatial discrimination learning task. Contrary to our prediction, females did not outperform males in the spatial task in either the acquisition or the reversal phases. Similarly, there were no sex differences in either phase in the visual task. During extinction, in both tasks the retention of females was significantly higher than expected by chance up to 50 days after the last rewarded session (∼85-90% of the trials with correct responses), but the performance of males at that time did not differ than that expected by chance. This last result shows a long-term memory capacity of female shiny cowbirds, which were able to remember information learned using either spatial or visual cues after a long retention interval. PMID:26248015

  20. Host switching in cowbird brood parasites: how often does it occur?

    PubMed

    Domínguez, M; de la Colina, M A; Di Giacomo, A G; Reboreda, J C; Mahler, B

    2015-06-01

    Avian obligate brood parasites lay their eggs in nests of host species, which provide all parental care. Brood parasites may be host specialists, if they use one or a few host species, or host generalists, if they parasitize many hosts. Within the latter, strains of host-specific females might coexist. Although females preferentially parasitize one host, they may occasionally successfully parasitize the nest of another species. These host switching events allow the colonization of new hosts and the expansion of brood parasites into new areas. In this study, we analyse host switching in two parasitic cowbirds, the specialist screaming cowbird (Molothrus rufoaxillaris) and the generalist shiny cowbird (M. bonariensis), and compare the frequency of host switches between these species with different parasitism strategies. Contrary to expected, host switches did not occur more frequently in the generalist than in the specialist brood parasite. We also found that migration between hosts was asymmetrical in most cases and host switches towards one host were more recurrent than backwards, thus differing among hosts within the same species. This might depend on a combination of factors including the rate at which females lay eggs in nests of alternative hosts, fledging success of the chicks in this new host and their subsequent success in parasitizing it. PMID:25903962

  1. A novel subgroup 16SrVII-D phytoplasma identified in association with Erigeron witches' broom.

    PubMed

    Flôres, Daniela; Amaral Mello, Ana Paula de Oliveira; Pereira, Thays Benites Camargo; Rezende, Jorge Alberto Marques; Bedendo, Ivan Paulo

    2015-08-01

    Erigeron sp. plants showing symptoms of witches' broom and stunting were found near orchards of passion fruit in São Paulo state, Brazil. These symptoms were indicative of infection by phytoplasmas. Thus, the aim of this study was to detect and identify possible phytoplasmas associated with diseased plants. Total DNA was extracted from symptomatic and asymptomatic plants and used in nested PCR conducted with the primer pairs P1/Tint and R16F2n/16R2. Amplification of genomic fragments of 1.2 kb from the 16S rRNA gene confirmed the presence of phytoplasma in all symptomatic samples. The sequence identity scores between the 16S rRNA gene of the phytoplasma strain identified in the current study and those of previously reported 'Candidatus Phytoplasma fraxini'-related strains ranged from 98% to 99% indicating the phytoplasma to be a strain affiliated with 'Candidatus Phytoplasma fraxini'. The results from a phylogenetic analysis and virtual RFLP analysis of the 16S rRNA gene sequence with 17 restriction enzymes revealed that the phytoplasma strain belongs to the ash yellows phytoplasma group (16SrVII); the similarity coefficient of RFLP patterns further suggested that the phytoplasma represents a novel subgroup, designated 16SrVII-D. The representative of this new subgroup was named EboWB phytoplasma (Erigeron bonariensis Witches' Broom). PMID:25911533

  2. Host selection by the shiny cowbird

    USGS Publications Warehouse

    Wiley, J.W.

    1988-01-01

    Factors important in Shiny Cowbird (Molothrus bonariensis) host selection were examined within the mangrove community in Puerto Rico. Cowbirds did not parasitize birds in proportion to their abundance. The cowbird breeding season coincided with those of its major hosts, which were 'high-quality' foster species (i.e., species that fledge .gtoreq. 55% of cowbirds hatched: Yellow Warbler, Dendroica petechia; Yellow-shouldered Blackbird, Agelaius xanthomus; Black-whiskered Vireo, Vireo altiloquus; Black-cowled Oriole, Icterus dominicensis; Peurto Rican Flycatcher, Myiarchus antillarum; Troupial, Icterus icterus), and did not extend into other periods even though nests of 'low-quality: species (i.e., species that fledge < 55% of cowbird chicks that hatched: Bronze Mannikin, Lonchura cucullata; Greater Antillean Grackle, Quiscalus niger; Gray Kingbird, Tyrannus dominicensis; Northern Mockingbird, Mimus polyglottos; Red-legged Thrush, Turdus plumbeus) were available. Shiny Cowbird food habits and egg size were similar to those of their hosts, suggesting that cowbirds choose hosts partly on the basis of this combination. Cowbirds located host nests primarily by cryptically watching activities of birds in likely habitats. Other nest locating strategies were active searching of suitable habitat and 'flushing' of hosts by the cowbird's noisy approach. Cowbirds closely monitored nest status with frequent visits that peaked on the host's first day of egg laying. Hosts using covered nests (e.g., cavities, domed nests) were as vulnerable to cowbird parasitism as those building open nests.

  3. Review of potential environmental impacts of transgenic glyphosate-resistant soybean in Brazil.

    PubMed

    Cerdeira, Antonio L; Gazziero, Dionsio L P; Duke, Stephen O; Matallo, Marcus B; Spadotto, Claudio A

    2007-01-01

    Transgenic glyphosate-resistant soybeans (GRS) have been commercialized and grown extensively in the Western Hemisphere, including Brazil. Worldwide, several studies have shown that previous and potential effects of glyphosate on contamination of soil, water, and air are minimal, compared to those caused by the herbicides that they replace when GRS are adopted. In the USA and Argentina, the advent of glyphosate-resistant soybeans resulted in a significant shift to reduced- and no-tillage practices, thereby significantly reducing environmental degradation by agriculture. Similar shifts in tillage practiced with GRS might be expected in Brazil. Transgenes encoding glyphosate resistance in soybeans are highly unlikely to be a risk to wild plant species in Brazil. Soybean is almost completely self-pollinated and is a non-native species in Brazil, without wild relatives, making introgression of transgenes from GRS virtually impossible. Probably the highest agricultural risk in adopting GRS in Brazil is related to weed resistance. Weed species in GRS fields have shifted in Brazil to those that can more successfully withstand glyphosate or to those that avoid the time of its application. These include Chamaesyce hirta (erva-de-Santa-Luzia), Commelina benghalensis (trapoeraba), Spermacoce latifolia (erva-quente), Richardia brasiliensis (poaia-branca), and Ipomoea spp. (corda-de-viola). Four weed species, Conyza bonariensis, Conyza Canadensis (buva), Lolium multiflorum (azevem), and Euphorbia heterophylla (amendoim bravo), have evolved resistance to glyphosate in GRS in Brazil and have great potential to become problems. PMID:17562462

  4. Kinetic Analysis of Resistance to Paraquat in Conyza: Evidence that Paraquat Transiently Inhibits Leaf Chloroplast Reactions in Resistant Plants.

    PubMed

    Shaaltiel, Y; Gressel, J

    1987-12-01

    Paraquat resistance has been claimed to be due to a sequestration of the herbicide before it reaches chloroplasts. This is based on the sensitivity of photosystem I in isolated thylakoids to paraquat, and autoradiographic analyses showing label from paraquat near veins 4 hours after treatment of a resistant biotype. Conversely, the enzymes of the superoxide detoxification pathway were found to be at constitutively elevated levels in intact class A chloroplasts of the resistant biotype of Conyza bonariensis (L.) Cronq. Evidence is presented here that physiologically active levels of paraquat rapidly inhibit chloroplast function in both the resistant and sensitive biotype, before the first sequestration was visualized. This inhibition is transient (completed in 2 hours) in the resistant biotype and irreversible in the sensitive type. Intact class A chloroplasts of the resistant biotype with or without paraquat are less susceptible to photoinduced membrane damage than the sensitive biotype without paraquat, as measured by ethane evolution. These data support a hypothesis that the ability to prevent superoxide damage keeps the resistant biotype viable while paraquat or its metabolites are being sequestered. PMID:16665821

  5. Glyphosate-resistant weeds of South American cropping systems: an overview.

    PubMed

    Vila-Aiub, Martin M; Vidal, Ribas A; Balbi, Maria C; Gundel, Pedro E; Trucco, Frederico; Ghersa, Claudio M

    2008-04-01

    Herbicide resistance is an evolutionary event resulting from intense herbicide selection over genetically diverse weed populations. In South America, orchard, cereal and legume cropping systems show a strong dependence on glyphosate to control weeds. The goal of this report is to review the current knowledge on cases of evolved glyphosate-resistant weeds in South American agriculture. The first reports of glyphosate resistance include populations of highly diverse taxa (Lolium multiflorum Lam., Conyza bonariensis L., C. canadensis L.). In all instances, resistance evolution followed intense glyphosate use in fruit fields of Chile and Brazil. In fruit orchards from Colombia, Parthenium hysterophorus L. has shown the ability to withstand high glyphosate rates. The recent appearance of glyphosate-resistant Sorghum halepense L. and Euphorbia heterophylla L. in glyphosate-resistant soybean fields of Argentina and Brazil, respectively, is of major concern. The evolution of glyphosate resistance has clearly taken place in those agroecosystems where glyphosate exerts a strong and continuous selection pressure on weeds. The massive adoption of no-till practices together with the utilization of glyphosate-resistant soybean crops are factors encouraging increase in glyphosate use. This phenomenon has been more evident in Argentina and Brazil. The exclusive reliance on glyphosate as the main tool for weed management results in agroecosystems biologically more prone to glyphosate resistance evolution. PMID:18161884

  6. Kinetic Analysis of Resistance to Paraquat in Conyza1

    PubMed Central

    Shaaltiel, Yoseph; Gressel, Jonathan

    1987-01-01

    Paraquat resistance has been claimed to be due to a sequestration of the herbicide before it reaches chloroplasts. This is based on the sensitivity of photosystem I in isolated thylakoids to paraquat, and autoradiographic analyses showing label from paraquat near veins 4 hours after treatment of a resistant biotype. Conversely, the enzymes of the superoxide detoxification pathway were found to be at constitutively elevated levels in intact class A chloroplasts of the resistant biotype of Conyza bonariensis (L.) Cronq. Evidence is presented here that physiologically active levels of paraquat rapidly inhibit chloroplast function in both the resistant and sensitive biotype, before the first sequestration was visualized. This inhibition is transient (completed in 2 hours) in the resistant biotype and irreversible in the sensitive type. Intact class A chloroplasts of the resistant biotype with or without paraquat are less susceptible to photoinduced membrane damage than the sensitive biotype without paraquat, as measured by ethane evolution. These data support a hypothesis that the ability to prevent superoxide damage keeps the resistant biotype viable while paraquat or its metabolites are being sequestered. PMID:16665821

  7. Effects of experimental egg composition on rejection by Village Weavers (Ploceus cucullatus)

    USGS Publications Warehouse

    Prather, J.W.; Cruz, A.; Weaver, P.F.; Wiley, J.W.

    2007-01-01

    We experimentally parasitized nests of the Village Weaver (Ploceus cucullatus) in Hispaniola using real and artificial eggs made from wood and modeling clay. Artificial eggs were similar in size and shape to real weaver eggs and were coated with acrylic paint and glazed. Real eggs were actual weaver eggs taken from Village Weaver nests. Experimental parasitic eggs (1) mimicked natural weaver eggs, (2) differed in color only, (3) differed in spotting only, or (4) mimicked Shiny Cowbird (Molothrus bonariensis) egg color and spotting pattern. Parasitized nests were checked after 2-6 days. Real eggs were ejected from weaver nests with increasing frequency as they became less similar to the eggs in the nest with cowbirds eggs having the highest rejection (81%). However, for artificial egg types there were no significant within-composition differences in patterns of rejection. Clay eggs were usually ejected from the nests, whereas nests containing wood eggs often ended empty, or with only the artificial egg remaining in the nest. These patterns may reflect the differential ability of weavers to recognize and remove foreign eggs of different compositions from their nests. Researchers undertaking egg-rejection experiments should use real eggs either in addition or in place of artificial eggs to assess the cost of rejection and the coevolutionary relationships between parasite and host.

  8. [Presence, abundance and reproductive strategies of ferns in disturbed areas of Sierra Nevada, México].

    PubMed

    Rodríguez Romero, Ma Lucía; Zavala Hurtado, José Alejandro; Pacheco, Leticia

    2011-03-01

    Diverse reproductive strategies shown by ferns and lycophytes allow them to colonize a variety of habitats, particularly after the incidence of natural or anthropogenic disturbances. This study assessed the presence, abundance and reproductive strategies of ferns growing in soils of temperate forests with different levels of disturbance at the Sierra Nevada mountain range in the State of Mexico. Vegetation, soil and environmental variables were recorded in 200 m2 permanent plots located in four forest stands. One-Way ANOVA and Canonical Correspondence Analysis resulted in the recognition of three landscape types defined by the degree of environmental alteration: low, moderate and severe. Also, from five soil samples collected in each stand, germination of ferns and lycophytes was induced. A positive relationship was found between the alteration degree and Cheilanthes abundance. Under a low landscape alteration regime, species richness is restricted to Cheilanthes bonariensis, C. marginata and Pellaea ternifolia subsp. ternifolia. The soil is a reservoir of spores of Cheilanthes and Pellaea ternifolia subsp. ternifolia because their spores can remain viable for different time intervals. Apogamy is the usual reproductive strategy of Cheilanthes species in disturbed ecosystems, although these species also show sexual reproduction in natural ecosystems with adequate water availability. Apogamy may be related to a shorter generation time in comparison with a low disturbed ecosystem. On the other hand, Pellaea ternifolia subsp. ternifolia only has sexual reproduction. Apogamy might be related to a faster generation in comparison with a low disturbed ecosystem. PMID:21516659

  9. Heightened exposure to parasites favors the evolution of immunity in brood parasitic cowbirds

    USGS Publications Warehouse

    Hahn, Caldwell; Reisen, William K.

    2011-01-01

    Immunologists and evolutionary biologists are interested in how the immune system evolves to fit an ecological niche. We studied the relationship between exposure to parasites and strength of immunity by investigating the response of two species of New World cowbirds (genus Molothrus, Icteridae), obligate brood parasites with contrasting life history strategies, to experimental arboviral infection. The South American shiny cowbird (M. bonariensis) is an extreme host-generalist that lays its eggs in the nests of >225 different avian species. The Central American bronzed cowbird (M. aeneus) is a relative host-specialist that lays its eggs preferentially in the nests of approximately 12 orioles in a single sister genus. West Nile virus provided a strong challenge and delineated immune differences between these species. The extreme host-generalist shiny cowbird, like the North American host-generalist, the brown-headed cowbird, showed significantly lower viremia to three arboviruses than related icterid species that were not brood parasites. The bronzed cowbird showed intermediate viremia. These findings support the interpretation that repeated exposure to a high diversity of parasites favors the evolution of enhanced immunity in brood parasitic cowbirds and makes them useful models for future studies of innate immunity.

  10. Multimatrix measurement of persistent organic pollutants in Mar Chiquita, a continental saline shallow lake.

    PubMed

    Ballesteros, M L; Miglioranza, K S B; Gonzalez, M; Fillmann, G; Wunderlin, D A; Bistoni, M A

    2014-08-15

    RAMSAR sites are determined by specific characteristics of the environment in terms of ecological productivity as well services for human development, but they are also one of the most threatened ecosystems. Thus, the objective of this work was to evaluate the dynamic of Persistent Organic Pollutants (POPs) in different biotic and abiotic matrixes of the RAMSAR site (wetlands with international importance), Mar Chiquita Lake. Sampling was performed according to land use (agricultural, urban, and industrial) at two stations: Laguna del Plata and Campo Mare. POPs were analyzed in superficial water (Sw), suspended particulate material (SPM), bottom sediment (Bs) and fish tissues (Odontesthes bonariensis). Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were analyzed by GC-ECD. HCHs, Endosulfans, DDTs, PCBs and PBDEs were found in all matrixes at both stations. The high persistence and transport processes are responsible for the occurrence of HCHs, DDTs and PCBs in Bs, SPM and fish tissues, even many years after their prohibition. PBDEs showed lower levels according to the scarcity of punctual sources in the area. Endosulfan showed variable amounts in agreement with application periods since this pesticide was used until a few years ago in this area. Finally, PCB levels overpassed the acceptable daily intake for human consumption being a risk for human health Thus, the present report confirms the occurrence of POPs in Mar Chiquita lake, alerting on the contribution of agricultural and urban pollutants in a RAMSAR site. Current results also raise concerns on biomagnification processes through the food web. PMID:24840282

  11. Egg rejection behavior in a population exposed to parasitism: Village Weavers on Hispaniola

    USGS Publications Warehouse

    Cruz, A.; Prather, J.W.; Wiley, J.W.; Weaver, P.F.

    2008-01-01

    In contrast to African Village Weavers (Ploceus cucullatus) that are parasitized by Diederik Cuckoos (Chrysococcyx caprius), introduced weavers on Hispaniola existed without parasitism for at least 2 centuries until the arrival of the Shiny Cowbird (Molothrus bonariensis) in the 1970s. Cruz and Wiley (1989) found that Hispaniolan weavers had a lower rejection rate of foreign eggs than African populations. Subsequently, Robert and Sorci (1999) and Lahti (2005, 2006) found that acceptance of dissimilar eggs is not characteristic of the species throughout its Hispaniolan range. In 1999-2002, we studied egg rejection in Hispaniolan weavers on a broad regional scale. Rejection increased as experimental eggs became increasingly different from the host eggs. Rejection rates for mimetic eggs, different color eggs, different-spotting eggs, and cowbird eggs was 23.2%, 33.3%, 61.5%, and 85.3%, respectively, with higher rejection of cowbird eggs in areas where cowbirds were observed. Although rejection is likely to have a genetic component, the differences could be due to phenotypic plasticity. Plasticity in egg rejection may be expected, given the potential cost of rejection and the spatiotemporal distribution of cowbirds. Thus, egg rejection has not necessarily decreased in Hispaniolan weavers, but it may act in a plastic manner, increasing where cowbirds are present. ?? The Author 2008. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved.

  12. Shiny cowbird parasitism in two avian communities in Puerto Rico

    USGS Publications Warehouse

    Wiley, J.W.

    1985-01-01

    The shiny cowbird (M. bonariensis), a brood parasite, has recently expanded its range from South America to Puerto Rico via the Lesser Antilles. This species is a host generalist and, on reaching Puerto Rico, encounteed avian species with no history of social parasitism. In mangrove habitat study areas, 42% of the resident non-raptorial land bird species were parasitized. Some species were heavily parasitized; e.g., yellow warbler (Dendroica petechia), 76% of nests parasitized black-whiskered vireo (Vireo altiloquus), 82%, Puerto Rican flycatcher (Myiarchus antillarum), 85%, yellow-shouldered blackbird (Agelaius xanthomus), 95%, troupial (Icterus icterus), 100%, black-cowled oriole (I. dominicensis), 100%. Others suffered low rates of parasitism (2-17% of nests examined); e.g., gray kingbird (Tyrannus dominicensis), red-legged thrush (Turdus plumbeus), bronze mannikin (Lonchura cucullata), northern mockingbird (Mimus polyglottos), greater antillean grackle (Quiscalus niger). Cowbird parasitism affected hosts by depressing nest success an average of 41% below non-parasitized nests and reducing host productivity. Parasitized host nests hatched 12% fewer eggs an fledged 67% fewer of their own chicks than non-parasitized pairs.

  13. Conservation of the yellow-shouldered blackbird, Agelaius xanthomus, an endangered West Indian species

    USGS Publications Warehouse

    Wiley, J.W.; Post, W.; Cruz, A.

    1991-01-01

    The yellow-shouldered blackbird Agelaius xanthomus, endemic to Puerto Rico and Mona Island, is endangered, mainly because of brood parasitism by the shiny cowbird Molothrus bonariensis, which reached Puerto Rico at least 30 years ago. The yellow-shouldered blackbird populations have since declined, about 770?1200 remaining (470?900 on Mona Island) by 1982?1986 compared to a population of about 2400 in 1975. Nearly all nests of blackbirds in most of its habitats are parasitized by cowbirds. This significantly reduces nesting success, but blackbirds have evolved no defenses against brood parasitism. Removal of cowbirds from the yellow-shouldered blackbird nesting grounds, modeled after similar programmes for the brown-headed cowbird Molothrus ater on Kirtland's warbler Dendroica kirtlandii nesting areas, significantly increased blackbird production. Blackbirds readily accept nest boxes, and breeding populations can be established in otherwise unusable sites and can be concentrated in mangrove habitats, were they are more easily protected by cowbird removal. Furthermore, yellow-shouldered blackbird pairs using cavities, including nest boxes, fledged more young per nest than pairs using open nests.

  14. New distributional data on aquatic and semiaquatic bugs (Hemiptera: Heteroptera: Gerromorpha & Nepomorpha) from South America

    PubMed Central

    Cordeiro, Isabelle R S

    2015-01-01

    Abstract Background Water bugs in general play an important role in freshwater ecosystems, and knowledge about them is essential for the study of water biology and the proper management of aquatic habitats. The Neotropical fauna is relatively well known, but the existence of large under-collected areas makes taxonomic and faunistic studies concerning the aquatic and semiaquatic bugs from tropical America urgent. New information Distributional information is presented for thirty-eight species of Gerromorpha and five Nepomorpha, including first records from the Brazilian states of Bahia (Mesovelia amoena), Ceará (Limnogonus profugus and Rhagovelia whitei), Espírito Santo (R. lucida), Goiás (Halobatopsis platensis and R. zela), Mato Grosso (Rheumatobates bonariensis), Pará (Nerthra terrestris), Paraná (H. spiniventris, Hydrometra fruhstorferi and R. janeira), Piauí (Microvelia ayacuchana, M. pulchella, Neogerris lubricus and Platyvelia brachialis), Rio de Janeiro (Martarega bentoi) and São Paulo (Rheumatobates minutus flavidus); and the Peruvian region of Madre de Dios (Rhagovelia fontanalis). PMID:25892925

  15. Deep-depletion breakdown of Johnsen-Rahbek type electrostatic chuck operation for semiconductor processes

    NASA Astrophysics Data System (ADS)

    Qin, Shu; McTeer, Allen

    2008-11-01

    Johnsen-Rahbek type (JR type) electrostatic chuck (ESC) was found to be more sensitive to wafer conditions than classic ESC, including backside dielectric quality and thickness, wafer type, and doping level. Wafer type and doping level may significantly affect the reliability of ESC operations, depending on ESC configurations and operation conditions. Deep-depletion breakdown phenomenon of a JR type ESC operation, which is equivalent to a metal-insulator-semiconductor capacitor, was simulated by PISCES-IIB device simulator, and it was found to be a mechanism of the reliability and pop-off issues of JR type ESC operations. In this paper, the potential solutions are proposed to solve these issues.

  16. Charge collected by diffusion from an ion track under mixed boundary conditions

    NASA Technical Reports Server (NTRS)

    Edmonds, Larry D.

    1991-01-01

    Charge-carrier diffusion from an ion track in a silicon substrate at least a few hundred microns thick is analyzed. The substrate upper surface is treated as reflective except for a small section, intended to represent a reverse-biased junction, which is treated as a sink. Total charge collected by the sink is calculated by assuming transport to be governed by an ambipolar diffusion equation with temporally constant and spatially uniform carrier lifetime and diffusion coefficient. Present results apply to a normally incident track but could easily be generalized to arbitrary track direction. The collected charge is found to depend on track length and on the electrostatic capacitance, rather than the area, of the sink. Theoretical predictions are compared to the results of a numerical simulation called the Poisson and Continuity Equation Solver (PISCES) for three cases and are found to agree within a factor of two in the worst case.

  17. A Fitting Routine to Obtain Temperature and Relative Spectral Emissivity from Mixed Material (C, W, Be) Surfaces in PSI Experiments

    NASA Astrophysics Data System (ADS)

    Seraydarian, Ray; Hanna, Jeremy; Doerner, Russ; Baldwin, Matt

    2007-11-01

    A nonlinear least-squares fitting code has been written to fit a black body profile multiplied by a polynomial spectral emissivity to the data from an IR spectroscopy diagnostic on the PISCES-B machine. The result is the absolute surface temperature and the coefficients of the polynomial emissivity. Emissivity measurements are important for thermal balance calculations of first wall materials in ITER, especially under conditions for which mixed materials can be created (e.g., combinations of C, W and Be) for which no other emissivity data are available. A straightforward data-to-theory-function fit is made possible by an intensity calibration using a commercially available illumination source. The raw spectrum has sufficient detail (512 pixels) to see and eliminate atomic line emission and absorption features from the spectrum before fitting. Fitting code details and preliminary experimental data analysis will be presented and discussed.

  18. The structure of the nearby universe traced by theIRAS galaxies

    NASA Technical Reports Server (NTRS)

    Yahil, Amos

    1993-01-01

    One of the most important discoveries of the Infrared Astronomical Satellite (IRAS) has been the detection of about 20,000 galaxies with 60 microns fluxes above 0.5 Jy. From the observational point of view, the IRAS galaxies are ideal tracers of density, since they are homogeneously detected over most of the sky, and their fluxes are unaffected by galactic extinction. The nearby universe was mapped by the IRAS galaxies to a distance of approximately 200 h(exp -1) Mpc for the absolute value of b less than 5 deg. The ability to map down to such low galactic latitudes has proven to be particularly imporant, since some of the most important nearby large-scale structures, such as the Great Attractor, the Perseus-Pisces region, and the Shapley concentration, all lie there. Two major results of the U.S. IRAS redshift survey are discussed.

  19. Operation of the adaptive optics system at the Large Binocular Telescope Observatory

    NASA Astrophysics Data System (ADS)

    Miller, Douglas L.; Guerra, Juan Carlos; Boutsia, Konstantina; Fini, Luca; Argomedo, Javier; Biddick, Chris; Agapito, Guido; Arcidiacono, Carmelo; Briguglio, Runa; Brusa, Guido; Busoni, Lorenzo; Esposito, Simone; Hill, John; Kulesa, Craig; McCarthy, Don; Pinna, Enrico; Puglisi, Alfio T.; Quiros-Pacheco, Fernando; Riccardi, Armando; Xompero, Marco

    2012-07-01

    The Adaptive Optics System at the Large Binocular Telescope Observatory consists of two Adaptive Secondary (ASM) mirrors and two Pyramid Wavefront sensors. The first ASM/Pyramid pair has been commissioned and is being used for science operation using the NIR camera PISCES on the right side of the binocular telescope. The left side ASM/Pyramid system is currently being commissioned, with completion scheduled for the Fall of 2012. We will discuss the operation of the first Adaptive Optics System at the LBT Observatory including interactions of the AO system with the telescope and its TCS, observational modes, user interfaces, observational scripting language, time requirement for closed loop and offsets and observing efficiency.

  20. [Embrionary-larval development of the tropical fish Hemirhamphus brasiliensis (Beloniformes: Hemirhamphidae) from eggs collected in the wild].

    PubMed

    Rosas, Jesús; Mata, Ernesto; Velásquez, Aidé; Cabrera, Tomas

    2008-09-01

    The embryo formation and larval development of Hemirhamphus brasiliensis Linnaeus, 1758 (Pisces: Hemirhamphidae) is described from morula stage eggs collected on Sargassum sp. Thalii in the field (10 degrees 50'55.2" N y 64 degrees 09'467" W). The eggs were spherical, 1 923.54 +/- 72.35 microm diameter with several corionic filaments, and are striated. During the first 48 h the embryo developed cephalic vesicle, miomers, and a heart located on the external body surface, beating strongly and circulating colorless blood which became pigmented red later. Before hatching, the larva developed kidney, gut tract, liver and biliar vesicle, pectoral fins, four pairs of gill arches and the mouth. The larva hatched at 114 h, the body was torpedo-shaped, yellow-green, with several dendriform melanophores; the pelvic fin was observed 72 h post hatching. At 240 hours the metamorphoses was completed. When the larvae hatched they could ingest Artemia metanauplii. PMID:19419056

  1. Redescriptions of Polysteganus coeruleopunctatus (Klunzinger 1870) and P. lineopunctatus (Boulenger 1903), with two new species from Western Indian Ocean.

    PubMed

    Iwatsuki, Yukio; Heemstra, Phillip C

    2015-01-01

    Five valid species in the genus Polysteganus (Pisces; Sparidae) from the Western Indian Ocean are currently known: P. baissaci Smith 1978, P. coeruleopunctatus (Klunzinger 1870), P. mascarenensis Iwatsuki & Heemstra, 2011, P. praeorbitalis (Günther 1859), and P. undulosus (Regan 1908). Although P. lineopunctatus (Boulenger 1903) has long been synonymized under P. coeruleopunctatus, both species are redescribed as valid. Two new species of Polysteganus were discovered in the course of this review. Polysteganus flavodorsalis n. sp. is described on the basis of six type specimens (143-265 mm SL) from Nazareth Bank, Mascarene Plateau, Indian Ocean, and P. cerasinus n. sp. is described based on the holotype (134 mm SL) from Saya de Malha Bank. Provisional distribution patterns of the eight valid species of Polysteganus in the Western Indian Ocean are discussed. A key to the species of Polysteganus is provided. PMID:26701557

  2. Working session 2: Tubing inspection

    SciTech Connect

    Guerra, J.; Tapping, R.L.

    1997-02-01

    This session was attended by delegates from 10 countries, and four papers were presented. A wide range of issues was tabled for discussion. Realizing that there was limited time available for more detailed discussion, three topics were chosen for the more detailed discussion: circumferential cracking, performance demonstration (to focus on POD and sizing), and limits of methods. Two other subsessions were organized: one dealt with some challenges related to the robustness of current inspection methods, especially with respect to leaving cracked tubes in service, and the other with developing a chart of current NDE technology with recommendations for future development. These three areas are summarized in turn, along with conclusions and/or recommendations. During the discussions there were four presentations. There were two (Canada, Japan) on eddy current probe developments, both of which addressed multiarray probes that would detect a range of flaws, one (Spain) on circumferential crack detection, and one (JRC, Petten) on the recent PISC III results.

  3. Complete mitochondrial genome of the largest living fish: whale shark Rhincodon typus (Orectolobiformes: Rhincodontidae).

    PubMed

    Chen, Xiao; Ai, Weiming; Pan, Lianghao; Shi, Xiaofang

    2016-01-01

    The whale shark Rhincodon typus (Pisces: Chondrichthyes, Orectolobiformes, Rhincodontidae) is the largest living fish on Earth. In this study, we presented its complete mitogenome. It is 16,928 bp in length, contains 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and one control region with the typical gene order and transcriptional direction in the vertebrates. Overall base composition of the R. typus mitogenome is 33.5% A, 24.3% C, 12.8% G and 29.5% T. Two start codon (GTG and ATG) and two stop codon patterns (TAG and TAA/T) were found in protein-coding genes. The tRNA-Ser2 could not be folded into the typical cloverleaf secondary structure because of the replacement of its dihydrouridine arm by a simple loop. A termination associated sequences (TAS) and three conserved sequence blocks (CSB1-3) were identified in the control region. PMID:24660935

  4. IRAS galaxies versus POTENT mass - Density fields, biasing, and Omega

    NASA Technical Reports Server (NTRS)

    Dekel, Avishai; Bertschinger, Edmund; Yahil, Amos; Strauss, Michael A.; Davis, Marc; Huchra, John P.

    1993-01-01

    A comparison of the galaxy density field extracted from a complete redshift survey of IRAS galaxies brighter than 1.936 Jy with the mass-density field reconstructed by the POTENT procedure from the observed peculiar velocities of 493 objects is presented. A strong correlation is found between the galaxy and mass-density fields; both feature the Great Attractor, part of the Perseus-Pisces supercluster, and the large void between them. Monte Carlo noise simulations show that the data are consistent with the hypotheses that the smoothed fluctuations of galaxy and mass densities at each point are proportional to each other with the 'biasing' factor of IRAS galaxies, b(I), and that the peculiar velocity field is related to the mass-density field as expected according to the gravitational instability theory. Under these hypotheses, the two density fields can be related by specifying b(I) and the cosmological density parameter, Omega.

  5. Systematic investigation of the formation behavior of helium bubbles in tungsten

    NASA Astrophysics Data System (ADS)

    Miyamoto, M.; Mikami, S.; Nagashima, H.; Iijima, N.; Nishijima, D.; Doerner, R. P.; Yoshida, N.; Watanabe, H.; Ueda, Y.; Sagara, A.

    2015-08-01

    The formation of He bubbles in tungsten under exposure to a He plasma was systematically investigated using low energy (∼50 eV) He+ ions with a wide fluence range (∼1023 to 1026 m-2) in the linear divertor plasma simulator PISCES-A at several temperatures (523-973 K). TEM observations after thinning exposed W samples with FIB revealed that the layer thickness (>30 nm) of He bubbles largely exceeds the ion implantation range of a few nm. The size of He bubbles was found to increase with an increase in the sample temperature: it was around 10 nm at 973 K, while only small He bubbles of 1-2 nm were observed at <773 K. In addition, to obtain information on the initial formation behavior, in-situ TEM observations during He ion irradiation were also performed.

  6. The Undergraduate ALFALFA Team: Collaborative Research Projects

    NASA Astrophysics Data System (ADS)

    Cannon, John M.; Koopmann, Rebecca A.; Haynes, Martha P.; Undergraduate ALFALFA Team, ALFALFA Team

    2016-01-01

    The NSF-sponsored Undergraduate ALFALFA (Arecibo Legacy Fast ALFA) Team (UAT) has allowed faculty and students from a wide range of public and private colleges and especially those with small astronomy programs to learn how science is accomplished in a large collaboration while contributing to the scientific goals of a legacy radio astronomy survey. The UAT has achieved this through close collaboration with ALFALFA PIs to identify research areas accessible to undergraduates. In this talk we will summarize the main research efforts of the UAT, including multiwavelength followup observations of ALFALFA sources, the UAT Collaborative Groups Project, the Survey of HI in Extremely Low-mass Dwarfs (SHIELD), and the Arecibo Pisces-Perseus Supercluster Survey. This work has been supported by NSF grants AST-0724918/0902211, AST-075267/0903394, AST-0725380, and AST-1211005.

  7. Predicting the velocity and azimuth of fragments generated by the range destruction or random failure of rocket casings and tankage

    NASA Technical Reports Server (NTRS)

    Eck, Marshall; Mukunda, Meera

    1988-01-01

    A calculational method is described which provides a powerful tool for predicting solid rocket motor (SRM) casing and liquid rocket tankage fragmentation response. The approach properly partitions the available impulse to each major system-mass component. It uses the Pisces code developed by Physics International to couple the forces generated by an Eulerian-modeled gas flow field to a Lagrangian-modeled fuel and casing system. The details of the predictive analytical modeling process and the development of normalized relations for momentum partition as a function of SRM burn time and initial geometry are discussed. Methods for applying similar modeling techniques to liquid-tankage-overpressure failures are also discussed. Good agreement between predictions and observations are obtained for five specific events.

  8. A fast spatial scanning combination emissive and mach probe for edge plasma diagnosis

    SciTech Connect

    Lehmer, R.D.; LaBombard, B.; Conn, R.W.

    1989-04-01

    A fast spatially scanning emissive and mach probe has been developed for the measurement of plasma profiles in the PISCES facility at UCLA. A pneumatic cylinder is used to drive a multiple tip probe along a 15cm stroke in less than 400msec, giving single shot profiles while limiting power deposition to the probe. A differentially pumped sliding O-ring seal allows the probe to be moved between shots to infer two and three dimensional profiles. The probe system has been used to investigate the plasma potential, density, and parallel mach number profiles of the presheath induced by a wall surface and scrape-off-layer profile modifications in biased limiter simulation experiments. Details of the hardware, data acquisition electronics, and tests of probe reliability are discussed. 30 refs., 24 figs.

  9. Si mass and the entropy distribution of the AWM7 cluster out to r500

    NASA Astrophysics Data System (ADS)

    Matsushita, Kyoko

    2013-10-01

    The AWM 7 cluster is a nearby bright cluster (z=0.017; kT=3.7 keV), which forms a part of the Perseus- Pisces filament. We propose to map the AWM 7 cluster to cover 0.3-1 r500 with 8 pointings with a 200 ks total exposure. One objective is to derive Si abundance out to r500. With Suzaku data out to the virial radius, we will be able to constrain the ratio of the Si mass in the ICM and total stellar luminosity of galaxies out to the virial radius. Another objective is to derive two-dimensional maps of temperature and entropy, and with the Suzaku data out to the virial radius, and to study history of accretion along the filament and gas heating.

  10. ROSAT observations of the galaxy group AWM 7.

    NASA Astrophysics Data System (ADS)

    Neumann, D. M.; Boehringer, H.

    1995-09-01

    We present results of ROSAT/PSPC and HRI observations of the AWM 7 group of galaxies, which is a poor galaxy cluster and forms part of the Perseus-Pisces filament. The X-ray emission originates from intracluster gas at temperatures of 1.7 to 4.5keV. The cluster obviously is elliptical with a position angle perpendicular to the position angle of the dominant elliptical galaxy NGC 1129, which is offset from the cluster X-ray centre by 30kpc. The analysis of the PSPC imaging and spectral data yield a gravitational mass of 2-5x10^14^Msun_within a radius of 1.2Mpc and a cooling flow with a mass deposition rate of up to 60-66Msun_/yr.

  11. Spectroscopic characterization and imaging of laser- and unipolar arc-induced plasmas

    SciTech Connect

    Aussems, Damien U. B.; Nishijima, Daisuke; Brandt, Christian; Doerner, Russell P.; Cardozo, Niek J. Lopes

    2014-08-14

    Tungsten plasmas induced by unipolar arcs were investigated using optical emission spectroscopy and imaging, and compared with laser-induced tungsten plasmas. The unipolar arcs were initiated in the linear-plasma simulator PISCES-A at UCSD under fusion relevant conditions. The electron temperature and density of the unipolar arc plasmas were in the range 0.5–0.7 eV and 0.7–2.0 × 10{sup 20 }m{sup −3}, respectively, and increased with increasing negative bias voltage, but did not correlate with the surface temperature. In comparison, the electron temperature and density of the laser-induced plasmas were in the range 0.6–1.4 eV and 7 × 10{sup 19}–1 × 10{sup 22 }m{sup −3}, respectively.

  12. The Extended Halo of Centaurus A: Uncovering Satellites, Streams, and Substructures

    NASA Astrophysics Data System (ADS)

    Crnojević, D.; Sand, D. J.; Spekkens, K.; Caldwell, N.; Guhathakurta, P.; McLeod, B.; Seth, A.; Simon, J. D.; Strader, J.; Toloba, E.

    2016-05-01

    We present the widest-field resolved stellar map to date of the closest (D˜ 3.8 Mpc) massive elliptical galaxy NGC 5128 (Centaurus A; Cen A), extending out to a projected galactocentric radius of ˜150 kpc. The data set is part of our ongoing Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS) utilizing the Magellan/Megacam imager. We resolve a population of old red giant branch (RGB) stars down to ˜1.5 mag below the tip of the RGB, reaching surface brightness limits as low as {μ }V,0˜ 32 mag arcsec‑2. The resulting spatial stellar density map highlights a plethora of previously unknown streams, shells, and satellites, including the first tidally disrupting dwarf around Cen A (CenA-MM-Dw3), which underline its active accretion history. We report 13 previously unknown dwarf satellite candidates, of which 9 are confirmed to be at the distance of Cen A (the remaining 4 are not resolved into stars), with magnitudes in the range {M}V=-7.2 to ‑13.0, central surface brightness values of {μ }V,0=25.4{--}26.9 mag arcsec‑2, and half-light radii of {r}h=0.22{--}2.92 {{kpc}}. These values are in line with Local Group dwarfs but also lie at the faint/diffuse end of their distribution; interestingly, CenA-MM-Dw3 has similar properties to the recently discovered ultradiffuse galaxies in Virgo and Coma. Most of the new dwarfs are fainter than the previously known Cen A satellites. The newly discovered dwarfs and halo substructures are discussed in light of their stellar populations, and they are compared to those discovered by the PAndAS survey of M31. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

  13. Shillapoo Wildlife Area, Annual Report 2006-2007.

    SciTech Connect

    Calkins, Brian

    2006-10-01

    This report summarizes accomplishments, challenges and successes on WDFW's Shillapoo Wildlife Area funded under Bonneville Power Administration's (BPA) Wildlife Mitigation Program (BPA project No.2003-012-00) during the Fiscal Year 07 contract period October 1, 2006-September 30, 2007. The information presented here is intended to supplement that contained in BPA's PISCES contract development and reporting system. The organization below is by broad categories of work but references are made to individual work elements in the PISCES Statement of Work as appropriate. The greatest success realized during this contract period was significant positive changes in the vegetative community in several wetland basins throughout the wildlife area. This major goal is being achieved in part by new equipment and operation capability funded under the BPA contract, state capital and migratory bird stamp funds, and the past or ongoing investment of other partners including Ducks Unlimited, The Natural Resources Conservation Service (NRCS), Clark Public Utilities and others. We continue to be challenged by requirements under the archaeological and historic preservation act necessary to protect many sensitive sites known to occur within the wildlife area. The problems encountered to date have been largely administrative in nature and those experienced this year were unforeseen and probably unavoidable. Early in the contract period, WDFW and BPA had agreed to have a BPA staff archaeologist perform the survey and reporting work. Unexpectedly, just prior to the expected start date for the surveys, the employee resigned leaving BPA's staff short handed and necessitated contracting the work with an archaeological consultant. This delay caused us to forego work on several projects that are now deferred until the next contract period. The most notable projects impacted by this unfortunate circumstance are those involving the construction or repair of fences.

  14. A Tidally Disrupting Dwarf Galaxy in the Halo of NGC 253

    NASA Astrophysics Data System (ADS)

    Toloba, Elisa; Sand, David J.; Spekkens, Kristine; Crnojević, Denija; Simon, Joshua D.; Guhathakurta, Puragra; Strader, Jay; Caldwell, Nelson; McLeod, Brian; Seth, Anil C.

    2016-01-01

    We report the discovery of Scl-MM-Dw2, a new dwarf galaxy at a projected separation of ∼50 kpc from NGC 253, as part of the Panoramic Imaging Survey of Centaurus and Sculptor project (PISCeS). We measure a tip of the red giant branch (RGB) distance of 3.12 ± 0.30 Mpc, suggesting that Scl-MM-Dw2 is likely a satellite of NGC 253. We qualitatively compare the distribution of RGB stars in the color–magnitude diagram with theoretical isochrones and find that it is consistent with an old, ∼12 Gyr, and metal-poor, -2.3 \\lt [Fe/H] \\lt -1.1, stellar population. We also detect a small number of asymptotic giant branch stars consistent with a metal-poor 2–3 Gyr population in the center of the dwarf. Our non-detection of HI in a deep Green Bank Telescope spectrum implies a gas fraction {M}{HI}/{L}V\\lt 0.02 {M}ȯ /{L}ȯ . The stellar and gaseous properties of Scl-MM-Dw2 suggest that it is a dwarf spheroidal galaxy. Scl-MM-Dw2 has a luminosity of {M}V=-12.1+/- 0.5 mag and a half-light radius of rh =2.94+/- 0.46 {{kpc}}, which makes it moderately larger than dwarf galaxies in the Local Group of the same luminosity. However, Scl-MM-Dw2 is very elongated (ε =0.66+/- 0.06), and it has an extremely low surface brightness ({μ }0,V=27.7+/- 0.6 mag arcsec‑2). Its elongation and diffuseness make it an outlier in the ellipticity–luminosity and surface brightness–luminosity scaling relations. These properties suggest that this dwarf is being tidally disrupted by NGC 253.

  15. Inhibition of erythrocytes δ-aminolevulinic acid dehydratase (ALAD) activity in fish from waters affected by lead smelters

    USGS Publications Warehouse

    Schmitt, Christopher J.; Caldwell, Colleen A.; Olsen, Bill; Serdar, Dave; Coffey, Mike

    2002-01-01

    We assessed the effects on fish of lead (Pb) released to streamsby smelters located in Trail, BC (Canada), E. Helena, MT, Herculaneum, MO, and Glover, MO. Fish were collected by electrofishing from sites located downstream of smelters and from reference sites. Blood from each fish was analyzed for δ-aminolevulinic acid dehydratase (ALAD) activity and hemoglobin (Hb), and samples of blood, liver, or carcass were analyzed for Pb, zinc (Zn), or both. Fish collected downstreamof all four smelters sites had elevated Pb concentrations, decreased ALAD activity, or both relative to their respectivereference sites. At E. Helena, fish from the downstream site also had lower Hb concentrations than fish from upstream. Differences among taxa were also apparent. Consistent with previous studies, ALAD activity in catostomids (Pisces: Catostomidae-northern hog sucker,Hypentelium nigricans;river carpsucker, Carpiodes carpio; largescale sucker, Catostomus macrocheilus; and mountain sucker, C. platyrhynchus) seemed more sensitive to Pb-induced ALADinhibition than the salmonids (Pisces: Salmonidae-rainbow trout,Oncorhynchus mykiss; brook trout,Salvelinus fontinalis) or common carp (Cyprinus carpio). Some of these differences may have resulted from differential accumulation of Zn, which was not measured at all sites. We detected noALAD activity in channel catfish (Ictaluruspunctatus) from either site on the Mississippi River at Herculaneum, MO. Our findings confirmed that Pb is releasedto aquatic ecosystems by smelters and accumulated by fish, andwe documented potentially adverse effects of Pb in fish. We recommend that Zn be measured along with Pb when ALAD activityis used as a biomarker and the collection of at least 10 fish ofa species at each site to facilitate statistical analysis.

  16. Development and Application of a Streamflow Disaggregation Tool in Natural Waterways

    NASA Astrophysics Data System (ADS)

    Acharya, A.; Ryu, J.

    2013-12-01

    A simple streamflow disaggregation method/tool has been developed to disaggregate streamflow from monthly to daily time steps. This disaggregation method is simple, site specific, data driven, flexible and adaptive at any regions and by any organizations that are looking for less intensive and less time consuming method of streamflow disaggregation from monthly to daily scale. The application of this methodology has been demonstrated through its application at both regulated and unregulated rivers located in Idaho. The flow indexes, which are developed with respect to historical data at the Source Station (SS), are applied to monthly streamflow at target station (TSS) while performing disaggregation. The selection of SS is based on minimum error criteria which is calculated for each 3-month seasonal flow volume for each year. An additional cubic spline interpolation is applied for unregulated cases to smoothen sudden high/low flows during month to month transition. The performance of this method to synthesize daily streamflow while preserving historical daily streamflow at both regulated and unregulated cases is evaluated based on different metrics such as statistical parameters, total runoff volume, peak runoff e.t.c.. The availability of finer scale (daily or shorter) hydrologic data can be utilized by water engineers in water resources management including reservoir operation, water quality and ecological modeling. This tool has been incorporated into the "PISCES" software program developed by the Bureau of Reclamation Pacific NorthWest Region (at http://www.usbr.gov/pn/hydromet/pisces) and this tool can also be directly assessed through http://water.cals.uidaho.edu/products/UIDisagg/ .

  17. DISCOVERY OF A NEW FAINT DWARF GALAXY ASSOCIATED WITH NGC 253

    SciTech Connect

    Sand, D. J.; Crnojević, D.; Strader, J.; Toloba, E.; Guhathakurta, P.; Caldwell, N.; McLeod, B.; Seth, A. C.

    2014-09-20

    We report the discovery of a new faint dwarf galaxy, which we dub Scl-MM-Dw1, at a projected distance of ∼65 kpc from the spiral galaxy NGC 253. The discovery results from the Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS), a program with the Magellan/Megacam imager to study faint substructure in resolved stellar light around massive galaxies outside of the Local Group. We measure a tip of the red giant branch distance to Scl-MM-Dw1 of D = 3.9 ± 0.5 Mpc, consistent with that of NGC 253, making their association likely. The new dwarf's stellar population is complex, with an old, metal-poor red giant branch (≳10 Gyr, [Fe/H] ∼ –2), and an asymptotic giant branch with an age of ∼500 Myr. Scl-MM-Dw1 has a half-light radius of r{sub h} = 340 ± 50 pc and an absolute magnitude of M{sub V}  = –10.3 ± 0.6 mag, comparable to the Milky Way's satellites at the same luminosity. Once complete, our imaging survey of NGC 253 and other nearby massive galaxies will provide a census of faint substructure in halos beyond the Local Group, both to put our own environment into context and to confront models of hierarchical structure formation.

  18. The Extended Halo of Centaurus A: Uncovering Satellites, Streams, and Substructures

    NASA Astrophysics Data System (ADS)

    Crnojević, D.; Sand, D. J.; Spekkens, K.; Caldwell, N.; Guhathakurta, P.; McLeod, B.; Seth, A.; Simon, J. D.; Strader, J.; Toloba, E.

    2016-05-01

    We present the widest-field resolved stellar map to date of the closest (D∼ 3.8 Mpc) massive elliptical galaxy NGC 5128 (Centaurus A; Cen A), extending out to a projected galactocentric radius of ∼150 kpc. The data set is part of our ongoing Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS) utilizing the Magellan/Megacam imager. We resolve a population of old red giant branch (RGB) stars down to ∼1.5 mag below the tip of the RGB, reaching surface brightness limits as low as {μ }V,0∼ 32 mag arcsec‑2. The resulting spatial stellar density map highlights a plethora of previously unknown streams, shells, and satellites, including the first tidally disrupting dwarf around Cen A (CenA-MM-Dw3), which underline its active accretion history. We report 13 previously unknown dwarf satellite candidates, of which 9 are confirmed to be at the distance of Cen A (the remaining 4 are not resolved into stars), with magnitudes in the range {M}V=-7.2 to ‑13.0, central surface brightness values of {μ }V,0=25.4{--}26.9 mag arcsec‑2, and half-light radii of {r}h=0.22{--}2.92 {{kpc}}. These values are in line with Local Group dwarfs but also lie at the faint/diffuse end of their distribution; interestingly, CenA-MM-Dw3 has similar properties to the recently discovered ultradiffuse galaxies in Virgo and Coma. Most of the new dwarfs are fainter than the previously known Cen A satellites. The newly discovered dwarfs and halo substructures are discussed in light of their stellar populations, and they are compared to those discovered by the PAndAS survey of M31. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

  19. Quality assurance and control issues for HF radar wave and current measurements

    NASA Astrophysics Data System (ADS)

    Wyatt, Lucy

    2015-04-01

    HF radars are now widely used to provide surface current measurements over wide areas of the coastal ocean for scientific and operational applications. In general data quality is acceptable for these applications but there remain issues that impact on the quantity and quality of the data. These include problems with calibration and interference which impact on both phased array (e.g. WERA, Pisces) and direction-finding (e.g. SeaSonde) radars. These same issues and others (e.g. signal-to-noise, in-cell current variability, antenna sidelobes) also impact on the quality and quantity of wave data that can be obtained. These issues will be discussed in this paper, illustrated with examples from deployments of WERA, Pisces and SeaSonde radars in the UK, Europe, USA and Australia. These issues involve both quality assurance (making sure the radars perform to spec and the software is fully operational) and in quality control (identifying problems with the data due to radar hardware or software performance issues and flagging these in the provided data streams). Recommendations for the former, and current practice (of the author and within the Australian Coastal Ocean Radar Network, ACORN*) for the latter, will be discussed. The quality control processes for wave measurement are not yet as well developed as those for currents and data from some deployments can be rather noisy. Some new methods, currently under development by SeaView Sensing Ltd and being tested with ACORN data, will be described and results presented. *ACORN is a facility of the Australian Integrated Marine Observing System, IMOS. IMOS is a national collaborative research infrastructure, supported by Australian Government. It is led by University of Tasmania in partnership with the Australian marine and climate science community.

  20. A Tidally Disrupting Dwarf Galaxy in the Halo of NGC 253

    NASA Astrophysics Data System (ADS)

    Toloba, Elisa; Sand, David J.; Spekkens, Kristine; Crnojević, Denija; Simon, Joshua D.; Guhathakurta, Puragra; Strader, Jay; Caldwell, Nelson; McLeod, Brian; Seth, Anil C.

    2016-01-01

    We report the discovery of Scl-MM-Dw2, a new dwarf galaxy at a projected separation of ˜50 kpc from NGC 253, as part of the Panoramic Imaging Survey of Centaurus and Sculptor project (PISCeS). We measure a tip of the red giant branch (RGB) distance of 3.12 ± 0.30 Mpc, suggesting that Scl-MM-Dw2 is likely a satellite of NGC 253. We qualitatively compare the distribution of RGB stars in the color-magnitude diagram with theoretical isochrones and find that it is consistent with an old, ˜12 Gyr, and metal-poor, -2.3 < [Fe/H] < -1.1, stellar population. We also detect a small number of asymptotic giant branch stars consistent with a metal-poor 2-3 Gyr population in the center of the dwarf. Our non-detection of HI in a deep Green Bank Telescope spectrum implies a gas fraction {M}{HI}/{L}V< 0.02 {M}⊙ /{L}⊙ . The stellar and gaseous properties of Scl-MM-Dw2 suggest that it is a dwarf spheroidal galaxy. Scl-MM-Dw2 has a luminosity of {M}V=-12.1+/- 0.5 mag and a half-light radius of rh =2.94+/- 0.46 {{kpc}}, which makes it moderately larger than dwarf galaxies in the Local Group of the same luminosity. However, Scl-MM-Dw2 is very elongated (ɛ =0.66+/- 0.06), and it has an extremely low surface brightness ({μ }0,V=27.7+/- 0.6 mag arcsec-2). Its elongation and diffuseness make it an outlier in the ellipticity-luminosity and surface brightness-luminosity scaling relations. These properties suggest that this dwarf is being tidally disrupted by NGC 253.

  1. Review of the genus Endoreticulatus (Microsporidia, Encephalitozoonidae) with description of a new species isolated from the grasshopper Poecilimon thoracicus (Orthoptera: Tettigoniidae) and transfer of Microsporidium itiiti Malone to the genus.

    PubMed

    Pilarska, Daniela K; Radek, Renate; Huang, Wei-Fong; Takov, Danail I; Linde, Andreas; Solter, Leellen F

    2015-01-01

    The historic genus Pleistophora (Plistophora) is a highly polyphyletic clade with invertebrate Microsporidia reassigned to several new genera since the 1980s. Two genera, Endoreticulatus and Cystosporogenes, clearly separate into distinct but closely related clades based on small subunit ribosomal RNA analysis but are included in different families that are each polyphyletic. A microsporidium with morphology resembling the Endoreticulatus/Cystosporogenes clade was isolated from the grasshopper Poecilimon thoracicus from a site in Northwest Bulgaria. It produced intense infections in the digestive tract of the host but no behavioral changes were noted in infected individuals. Prevalence of the microsporidium increased over the active feeding season yearly. Mature spores were oval and measured 2.58±0.21 μm×1.34±0.24 μm, with 16 to approximately 32 spores in a parasitophorous vacuole. The spores were uninucleate and polar filament coils numbered 8-9 situated in a single row. The spore polaroplast consisted of an anterior lamellar section and a posterior vesicular section, and the posterior vacuole was reduced. Analyses of a 1221 bp partial SSU-rRNA sequence indicated that the isolate is more closely related to the Endoreticulatus clade than to Cystosporogenes, but shows earlier phylogenetic separation from species infecting Lepidoptera and represents a new species, Endoreticulatus poecilimonae. To compare sequences of Endoreticulatus spp. from Lepidoptera to those infecting other insect orders, an isolate, Microsporidium itiitiMalone (1985), described from the Argentine stem weevil, Listronotus bonariensis, was sequenced. Like the grasshopper isolate, the weevil isolate is closely related but basal to the lepidopteran Endoreticulatus clade. The original description combined with the new sequence data confirms species status and permits transfer of the isolate from Microsporidium, a genus erected for microsporidian species of uncertain taxonomic status, to

  2. Molecular tracking of individual host use in the Shiny Cowbird - a generalist brood parasite.

    PubMed

    de la Colina, Ma Alicia; Hauber, Mark E; Strausberger, Bill M; Reboreda, Juan Carlos; Mahler, Bettina

    2016-07-01

    Generalist parasites exploit multiple host species at the population level, but the individual parasite's strategy may be either itself a generalist or a specialist pattern of host species use. Here, we studied the relationship between host availability and host use in the individual parasitism patterns of the Shiny Cowbird Molothrus bonariensis, a generalist avian obligate brood parasite that parasitizes an extreme range of hosts. Using five microsatellite markers and an 1120-bp fragment of the mtDNA control region, we reconstructed full-sibling groups from 359 cowbird eggs and chicks found in nests of the two most frequent hosts in our study area, the Chalk-browed Mockingbird Mimus saturninus and the House Wren Troglodytes aedon. We were able to infer the laying behavior of 17 different females a posteriori and found that they were mostly faithful to a particular laying area and host species along the entire reproductive season and did not avoid using previously parasitized nests (multiple parasitism) even when other nests were available for parasitism. Moreover, we found females using the same host nest more than once (repeated parasitism), which had not been previously reported for this species. We also found few females parasitizing more than one host species. The use of an alternative host was not related to the main hosts' nest availability. Overall, female shiny cowbirds use a spatially structured and host species specific approach for parasitism, but they do so nonexclusively, resulting in both detectable levels of multiple parasitism and generalism at the level of individual parasites. PMID:27547305

  3. Developmental Variability of Photooxidative Stress Tolerance in Paraquat-Resistant Conyza.

    PubMed

    Amsellem, Z.; Jansen, MAK.; Driesenaar, ARJ.; Gressel, J.

    1993-12-01

    Paraquat-resistant hairy fleabane (Conyza bonariensis L. Cronq.) has been extensively studied, with some contention. A single, dominant gene pleiotropically controls levels of oxidant-detoxifying enzymes and tolerance to many photooxidants, to photoinhibition, and possibly to other stresses. The weed forms a rosette on humid short days and flowers in dry long days and, thus, needs plasticity to photooxidant stresses. In a series of four experiments over 20 months, the resistant and susceptible biotypes were cultured in constant 10-h low-light short days at 25[deg]C. Resistance was measured as recovery from paraquat. The concentration required to achieve 50% inhibition of the resistant biotype was about 30 times that of the susceptible one just after germination, increased to >300 times that of the susceptibles at 10 weeks of growth, and then decreased to 20-fold, remaining constant except for a brief increase while bolting. Resistance increased when plants were induced to flower by long days. The levels of plastid superoxide dismutase and of glutathione reductase were generally highest in resistant plants compared to those of the susceptibles at the times of highest paraquat resistance, but they were imperceptibly different from the susceptible type at the times of lower paraquat resistance. Photoinhibition tolerance measured as quantum yield of oxygen evolution at ambient temperatures was highest when the relative amounts of enzymes were highest in the resistant biotype. Resistance to photoinhibition was not detected by chlorophyll a fluorescence. Enzyme levels, photoinhibition tolerance, and paraquat resistance all increased during flowering in both biotypes. Imperceptibly small increases in enzyme levels would be needed for 20-fold resistance, based on the moderate enzyme increases correlated with 300-fold resistance. Thus, it is feasible that either these enzymes play a role in the first line of defense against photooxidants, or another, yet unknown mechanism

  4. Developmental Variability of Photooxidative Stress Tolerance in Paraquat-Resistant Conyza.

    PubMed Central

    Amsellem, Z.; Jansen, MAK.; Driesenaar, ARJ.; Gressel, J.

    1993-01-01

    Paraquat-resistant hairy fleabane (Conyza bonariensis L. Cronq.) has been extensively studied, with some contention. A single, dominant gene pleiotropically controls levels of oxidant-detoxifying enzymes and tolerance to many photooxidants, to photoinhibition, and possibly to other stresses. The weed forms a rosette on humid short days and flowers in dry long days and, thus, needs plasticity to photooxidant stresses. In a series of four experiments over 20 months, the resistant and susceptible biotypes were cultured in constant 10-h low-light short days at 25[deg]C. Resistance was measured as recovery from paraquat. The concentration required to achieve 50% inhibition of the resistant biotype was about 30 times that of the susceptible one just after germination, increased to >300 times that of the susceptibles at 10 weeks of growth, and then decreased to 20-fold, remaining constant except for a brief increase while bolting. Resistance increased when plants were induced to flower by long days. The levels of plastid superoxide dismutase and of glutathione reductase were generally highest in resistant plants compared to those of the susceptibles at the times of highest paraquat resistance, but they were imperceptibly different from the susceptible type at the times of lower paraquat resistance. Photoinhibition tolerance measured as quantum yield of oxygen evolution at ambient temperatures was highest when the relative amounts of enzymes were highest in the resistant biotype. Resistance to photoinhibition was not detected by chlorophyll a fluorescence. Enzyme levels, photoinhibition tolerance, and paraquat resistance all increased during flowering in both biotypes. Imperceptibly small increases in enzyme levels would be needed for 20-fold resistance, based on the moderate enzyme increases correlated with 300-fold resistance. Thus, it is feasible that either these enzymes play a role in the first line of defense against photooxidants, or another, yet unknown mechanism

  5. Paraquat Resistance in Conyza1

    PubMed Central

    Fuerst, E. Patrick; Nakatani, Herbert Y.; Dodge, Alan D.; Penner, Donald; Arntzen, Charles J.

    1985-01-01

    A biotype of Conyza bonariensis (L.) Cronq. (identical to Conyza linefolia in other publications) originating in Egypt is resistant to the herbicide 1,1′-dimethyl-4,4′-bipyridinium ion (paraquat). Penetration of the cuticle by [14C]paraquat was greater in the resistant biotype than the susceptible (wild) biotype; therefore, resistance was not due to differences in uptake. The resistant and susceptible biotypes were indistinguishable by measuring in vitro photosystem I partial reactions using paraquat, 6,7-dihydrodipyrido [1,2-α:2′,1′-c] pyrazinediium ion (diquat), or 7,8-dihydro-6H-dipyrido [1,2-α:2′,1′-c] [1,4] diazepinediium ion (triquat) as electron acceptors. Therefore, alteration at the electron acceptor level of photosystem I is not the basis for resistance. Chlorophyll fluorescence measured in vivo was quenched in the susceptible biotype by leaf treatment with the bipyridinium herbicides. Resistance to quenching of in vivo chlorophyll fluorescence was observed in the resistant biotype, indicating that the herbicide was excluded from the chloroplasts. Movement of [14C] paraquat was restricted in the resistant biotype when excised leaves were supplied [14C]paraquat through the petiole. We propose that the mechanism of resistance to paraquat is exclusion of paraquat from its site of action in the chloroplast by a rapid sequestration mechanism. No differential binding of paraquat to cell walls isolated from susceptible and resistant biotypes could be detected. The exact site and mechanism of paraquat binding to sequester the herbicide remains to be determined. Images Fig. 6 PMID:16664176

  6. Agricultural impacts of glyphosate-resistant soybean cultivation in South America.

    PubMed

    Cerdeira, Antonio L; Gazziero, Dionsio L P; Duke, Stephen O; Matallo, Marcus B

    2011-06-01

    In the 2009/2010 growing season, Brazil was the second largest world soybean producer, followed by Argentina. Glyphosate-resistant soybeans (GRS) are being cultivated in most of the soybean area in South America. Overall, the GRS system is beneficial to the environment when compared to conventional soybean. GRS resulted in a significant shift toward no-tillage practices in Brazil and Argentina, but weed resistance may reduce this trend. Probably the highest agricultural risk in adopting GRS in Brazil and South America is related to weed resistance due to use of glyphosate. Weed species in GRS fields have shifted in Brazil to those that can more successfully withstand glyphosate or to those that avoid the time of its application. Five weed species, in order of importance, Conyza bonariensis (L.) Cronquist, Conyza canadensis (L.) Cronquist, Lolium multiflorum Lam., Digitaria insularis (L.) Mez ex Ekman, and Euphorbia heterophylla L., have evolved resistance to glyphosate in GRS in Brazil. Conyza spp. are the most difficult to control. A glyphosate-resistant biotype of Sorghum halepense L. has evolved in GRS in Argentina and one of D. insularis in Paraguay. The following actions are proposed to minimize weed resistance problem: (a) rotation of GRS with conventional soybeans in order to rotate herbicide modes of action; (b) avoidance of lower than recommended glyphosate rates; (c) keeping soil covered with a crop or legume at intercrop intervals; (d) keeping machinery free of weed seeds; and (d) use of a preplant nonselective herbicide plus residuals to eliminate early weed interference with the crop and to minimize escapes from later applications of glyphosate due to natural resistance of older weeds and/or incomplete glyphosate coverage. PMID:20839871

  7. Physiological, morphological and biochemical studies of glyphosate tolerance in Mexican Cologania (Cologania broussonetii (Balb.) DC.).

    PubMed

    Alcántara de la Cruz, Ricardo; Barro, Francisco; Domínguez-Valenzuela, José Alfredo; De Prado, Rafael

    2016-01-01

    In recent years, glyphosate-tolerant legumes have been used as cover crops for weed management in tropical areas of Mexico. Mexican cologania (Cologania broussonetii (Balb.) DC.) is an innate glyphosate-tolerant legume with a potential as a cover crop in temperate areas of the country. In this work, glyphosate tolerance was characterized in two Mexican cologania (a treated (T) and an untreated (UT)) populations as being representatives of the species, compared in turn to a glyphosate-susceptible hairy fleabane (S) (Conyza bonariensis (L.) Cronq.) population. Experiments revealed that T and UT Mexican cologania populations had a higher tolerance index (TI), and a lower shikimic acid accumulation and foliar retention than the hairy fleabane S population. Absorption and translocation, leaf morphology and metabolism studies were only carried out in the Mexican cologania T population and the hairy fleabane S population. The latter absorbed 37% more (14)C-glyphosate compared to the Mexican cologania T at 96 h after treatment (HAT). Mexican cologania T translocated less herbicide from the treated leaf to the remainder of the plant than hairy fleabane S. The Mexican cologania T presented a greater epicuticular wax coverage percentage than the hairy fleabane S. This morphological characteristic contributed to the low glyphosate absorption observed in the Mexican cologania. In addition, the Mexican cologania T metabolized glyphosate mainly into AMPA, formaldehyde and sarcosine. These results indicate that the high glyphosate tolerance observed in Mexican cologania is mainly due to the poor penetration and translocation of glyphosate into the active site, and the high glyphosate degradation into non-toxic substances. PMID:26646239

  8. Weedy hosts and prevalence of potential leafhopper vectors (Hemiptera: Cicadellidae) of a phytoplasma (16SrIX group) associated with Huanglongbing symptoms in citrus groves.

    PubMed

    Marques, R N; Teixeira, D C; Yamamoto, P T; Lopes, J R S

    2012-04-01

    Huanglongbing (HLB) is a severe citrus (Citrus spp.) disease associated with the bacteria genus Candidatus Liberibacter, detected in Brazil in 2004. Another bacterium was found in association with HLB symptoms and characterized as a phytoplasma belonging to the 16SrIX group. The objectives of this study were to identify potential leafhopper vectors of the HLB-associated phytoplasma and their host plants. Leafhoppers were sampled every other week for 12 mo with sticky yellow cards placed at two heights (0.3 and 1.5 m) in the citrus tree canopy and by using a sweep net in the ground vegetation of two sweet orange, Citrus sinensis (L.) Osbeck, groves infected by the HLB-phytoplasma in São Paulo state. Faunistic analyses indicated one Agalliinae (Agallia albidula Uhler) and three Deltocephalinae [Balclutha hebe (Kirkaldy), Planicephalus flavicosta (Stål), and Scaphytopius (Convelinus) marginelineatus (Stål)] species, as the most abundant and frequent leafhoppers (Hemiptera: Cicadellidae). Visual observations indicated an association of leafhopper species with some weeds and the influence of weed species composition on leafhopper abundance in low-lying vegetation. S. marginelineatus and P. flavicosta were more frequent on Sida rhombifolia L. and Althernantera tenella Colla, respectively, whereas A. albidula was observed more often on Conyza bonariensis (L.) Cronq. and B. hebe only occurred on grasses. DNA samples of field-collected S. marginelineatus were positive by polymerase chain reaction and sequencing tests for the presence of the HLB-phytoplasma group, indicating it as a potential vector. The association of leafhoppers with their hosts may be used in deciding which management strategies to adopt against weeds and diseases in citrus orchards. PMID:22606800

  9. Paraquat resistance in conyza.

    PubMed

    Fuerst, E P; Nakatani, H Y; Dodge, A D; Penner, D; Arntzen, C J

    1985-04-01

    A biotype of Conyza bonariensis (L.) Cronq. (identical to Conyza linefolia in other publications) originating in Egypt is resistant to the herbicide 1,1'-dimethyl-4,4'-bipyridinium ion (paraquat). Penetration of the cuticle by [(14)C]paraquat was greater in the resistant biotype than the susceptible (wild) biotype; therefore, resistance was not due to differences in uptake. The resistant and susceptible biotypes were indistinguishable by measuring in vitro photosystem I partial reactions using paraquat, 6,7-dihydrodipyrido [1,2-alpha:2',1'-c] pyrazinediium ion (diquat), or 7,8-dihydro-6H-dipyrido [1,2-alpha:2',1'-c] [1,4] diazepinediium ion (triquat) as electron acceptors. Therefore, alteration at the electron acceptor level of photosystem I is not the basis for resistance. Chlorophyll fluorescence measured in vivo was quenched in the susceptible biotype by leaf treatment with the bipyridinium herbicides. Resistance to quenching of in vivo chlorophyll fluorescence was observed in the resistant biotype, indicating that the herbicide was excluded from the chloroplasts. Movement of [(14)C] paraquat was restricted in the resistant biotype when excised leaves were supplied [(14)C]paraquat through the petiole. We propose that the mechanism of resistance to paraquat is exclusion of paraquat from its site of action in the chloroplast by a rapid sequestration mechanism. No differential binding of paraquat to cell walls isolated from susceptible and resistant biotypes could be detected. The exact site and mechanism of paraquat binding to sequester the herbicide remains to be determined. PMID:16664176

  10. Thirty-seventh supplement to the American Ornithologists' Union checklist of North American birds

    USGS Publications Warehouse

    Monroe, Burt L.; Banks, Richard C.; Fitzpatrick, John W.; Howell, Thomas R.; Johnson, Ned K.; Ouellet, Henri; Remsen, J.V.; Storer, Robert W.

    1989-01-01

    This third supplement subsequent to the 6th edition (1983) of the A.O.U. "Check-list of North American Birds" consists of changes adopted by the Committee on Classification and Nomenclature as of 1 March 1989. The changes fall into nine categories: (1) six species are added to the main list (Pterodroma longirostris, Larus crassirostris, Streptopelia decaocto, Cocccyzus julieni, Chrysolampis mosquitus, Emberiza aureola) because of new distributional information; (2) five species (Ara cubensis, Chlorostilbon bracei, Empidonax occidentalis, Polioptila californica, Pipilo crissalis) are added to the main list because of the splitting of species already on the list; (3) one name (Anthus rubescens) is changed because of the splitting of a species from outside the Checklist area; (4) two names (Morus bassanus, Nyctanassa violacea) is removed from the main list to Appendix B because of re-evaluation of Northern Hemisphere records; (6) three species (Pterodrama rostrata, P. alba, P. solandri) are moved from Appendix A to Appendix B, and one (P. defilippiana) is added to Appendix B because of questionable sight records; (7)A.O.U. numbers are added to three species (Ciccaba virgata, Myiopagis viridicata, Molothrus bonariensis) on the basis on new distributional records or supporting data; (8) several corrections in spelling or citations are made; and (9) English names are changed for twelve species to accommodate worldwide usage of these names. No new distributional information is included except as indicated above (i.e. minor changes of distribution are not noted). These actions bring the number of species recognized as occurring in North America (main list) to 1,945.

  11. Ecology of avian brood parasitism at an early interfacing of host and parasite populations

    USGS Publications Warehouse

    Wiley, J.W.

    1982-01-01

    The shiny cowbird (Molothrus bonariensis), a brood parasite, has recently spread into the Greater Antilles from South America via the Lesser Antilles. This species is a host generalist and upon reaching Puerto Rico exploited avian communities with no history of social parasitism. Forty-two percent of the resident non-raptorial land bird species were parasitized in mangrove habitat study areas. Cowbird parasitism affected hosts by (1) depressing nest success an average of 41 percent below non-parasitized nests, and (2) reducing host productivity. Parasitized hosts produced 12 percent fewer eggs and fledged 67 percent fewer of their own chicks than non-parasitized pairs. Growth rates of chicks of some host species were lower in parasitized nests compared with non-parasitized nests while growth of others was not affected by brood parasitism. Cowbird chick growth varied directly with host size; i.e., cowbird chicks grew faster and attained greater fledging weight and body size in nests of larger hosts. Factors important in shiny cowbird host selection were examined within the mangrove study community. Cowbirds did not parasitize avian species in proportion to their abundance. The cowbird breeding season coincided with that of its major hosts, which were high quality foster species, and did not extend into other periods even though nests of poor quality species were available. Food habits and egg size of cowbirds were similar to those of their hosts, suggesting that cowbirds choose hosts partly on the basis of this alignment. Cowbirds locate nests by cryptically watching activities of birds in likely habitat. Despite the recency of the cowbird's arrival in Puerto Rico, some nesting species have effective anti-parasite strategies, including alien egg rejection and nest guarding. Behavior effective in avoiding parasitism is similar to that used by certain birds in evading nest predators. It is suggested that anti-predator behavior is preadaptive to countering cowbird

  12. VizieR Online Data Catalog: Mark III Catalog of Galaxy Peculiar Velocities (Willick+ 1997)

    NASA Astrophysics Data System (ADS)

    Willick, J. A.; Courteau, S.; Faber, S. M.; Burstein, D.; Dekel, A.; Kolatt, T.

    1996-08-01

    The Mark III Catalog of Galaxy Peculiar Velocities comprises five different types of data files. 1. Basic Observational and Catalog Data 2. Individual Galaxy TF and Dn-sigma Distances 3. Grouped Spiral Galaxy TF Distances 4. Elliptical Galaxy Distances as in the Mark II 5. Comparison of Spiral Galaxy Distances 1. The Basic Data files are: a. Aaronson et al. Field, (359 galaxies; a82): a82file1.dat, a82file2.dat, a82file3.dat b. Mathewson et al. 1992 (1355 galaxies; mat): matfile1.dat, matfile2.dat, matfile3.dat c. Willick 1991, Perseus-Pisces sample (383 galaxies; w91pp): d. Willick 1991, Cluster galaxy sample (156 galaxies; w91cl): The basic data for all 539 objects in the w91 sample are given in the following files: w91file1.dat, w91file2.dat, w91file3.dat Some galaxies are duplicates; see below for details. e. Courteau-Faber 1993 (326 galaxies; cf): cffile1.dat, cffile2.dat, cffile3.dat f. Han-Mould et al. 1992+, Cluster galaxy sample (433 galaxies; hmcl): The basic data for all 433 galaxies the the hm sample are given in the following files: hmfile1.dat, hmfile3.dat, hmfile2.dat Some galaxies are duplicates; see below for details. 2. The Individual Spiral Galaxy Distances Files are: (See notes for detailed descriptions of how the w91pp, w91cl, hmcl and cf distance files correspond to the galaxies in the w91file*, hmfile*, and cffile* Basic Data files.) a. Aaronson et al. Field, (359 galaxies; a82): a82_s b. Mathewson et al. 1992 (1355 galaxies; mat): mat_s c. Willick 1991, Perseus-Pisces sample (326 galaxies; w91pp): w91pp_s.dat d. Willick 1991, Cluster galaxy sample (156 galaxies; w91cl): w91cl_s.dat e. Courteau-Faber 1993 (321 galaxies; cf): cf_s.dat f. Han-Mould et al. 1992+, all cluster galaxies (427 galaxies; hmcl): hmcl_s.dat 3. The Grouped Spiral Galaxy Distance Files are: (Note: Group numbers in the wcf group (merged w91pp and cf) data file correspond to those in the w91pp and cf individual galaxy files. The hmw group file (merged w91cl and hmcl, 10

  13. SiC devices: Physics and numerical simulation

    NASA Astrophysics Data System (ADS)

    Ruff, Martin; Mitlehner, Heinz; Helbig, Reinhard

    1994-06-01

    The important material parameters for 6H silicon carbide (6H-SiC) are extracted from the literature and implemented into the 2-D device simulation programs PISCES and BREAKDOWN and into the 1-D program OSSI Simulations of 6H-SiC p-n junctions show the possibility to operate corresponding devices at temperatures up to 1000 K thanks to their low reverse current densities. Comparison of a 6H-SiC 1200 V p-n(-)-n(+) diode with a corresponding silicon (Si) diode shows the higher switching performance of the 6H-SiC diode, while the forward power loss is somewhat higher than in Si due to the higher built-in voltage of the 6H-SiC p-n junction. This disadvantage can be avoided by a 6H-SiC Schottky diode. The on-resistances of Si, 3C-SiC, and 6H-SiC vertical power MOSFET's are compared by analytical calculations. At room temperature, such SiC MOSFET's can operate up to blocking capabilities of 5000 V with an on-resistance below 0.1 (Omega) sq cm, while Si MOSFET's are limited to below 500 V. This is checked by calculating the characteristics of a 6H-SiC 1200 V MOSFET with PISCES. In the voltage region below 200 V, Si is superior due to its higher mobility and lower threshold voltage. Electric fields in the order of 4 x 10(exp 6) V/cm occur in the gate oxide of the mentioned 6H-SiC MOSFET as well as in a field plate oxide used to passivate its planar junction. To investigate the high frequency performance of SiC devices, a heterobipolartransistor with a 6H-SiC emitter is considered. Base and collector are assumed to be out of 3C-SiC. Frequencies up to 10 GHz with a very high output power are obtained on the basis of analytical considerations.

  14. The influence of the merger history of dwarf galaxies in a reionized universe

    NASA Astrophysics Data System (ADS)

    Verbeke, Robbert; Vandenbroucke, Bert; De Rijcke, Sven; Koleva, Mina

    2015-08-01

    In the ΛCDM model, cosmic structure forms in a hierarchical fashion. According to this paradigm, even low-mass dwarf galaxies grow via smooth accretion and mergers. Given the low masses of dwarf galaxies and their even smaller progenitors, the UV background is expected to have a significant influence on their gas content and, consequently, their star formation histories. Generally, cosmological simulations predict that most dwarf systems with circular velocities below ~30 km/s should not be able to form significant amounts of stars or contain gas and be, in effect, "dark" galaxies (Sawala et al. 2013, 2014; Hopkins et al. 2014; Shen et al. 2014). This is in contradiction with the recent discovery of low-mass yet gas-rich dwarf galaxies, such as Leo P (Skillman et al. 2013), Pisces A (Tollerud et al. 2014), and SECCO 1 (Bellazzini et al. 2015). Moreover, Tollerud et al. (2014) point out that most isolated dark-matter halos down to circular velocities of ~15 km/s contain neutral gas, in contradiction with the predictions of current simulations.Based on a suite of simulations of the formation and evolution of dwarf galaxies we show that, by reducing the first peak of star formation by including Pop-III stars in the simulations, the resulting dwarf galaxies have severely suppressed SFRs and can hold on to their gas reservoirs. Moreover, we show that the majority of the zero-metallicity stars are ejected during mergers, resulting in an extended, low-metallicity stellar halo. This results in a marked difference between a galaxy's "total" star-formation history and the one read from the stars in the center of the galaxy at z=0. This mechanism leads to the formation of realistic low-mass, gas-rich dwarfs with a broad range of SFHs and which adhere to the observed scaling relations, such as the baryonic Tully-Fisher relation.In short, the simulations presented here are for the first time able to reproduce the observed properties of low-mass, gas-rich dwarfs such as DDO 210

  15. DISCOVERY OF A CLOSE PAIR OF FAINT DWARF GALAXIES IN THE HALO OF CENTAURUS A

    SciTech Connect

    Crnojević, D.; Sand, D. J.; Caldwell, N.; McLeod, B.; Guhathakurta, P.; Toloba, E.; Simon, J. D.; Strader, J.

    2014-11-10

    As part of the Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS), we report the discovery of a pair of faint dwarf galaxies (CenA-MM-Dw1 and CenA-MM-Dw2) at a projected distance of ∼90 kpc from the nearby elliptical galaxy NGC 5128 (CenA). We measure a tip of the red giant branch distance to each dwarf, finding D = 3.63 ± 0.41 Mpc for CenA-MM-Dw1 and D = 3.60 ± 0.41 Mpc for CenA-MM-Dw2, both of which are consistent with the distance to NGC 5128. A qualitative analysis of the color-magnitude diagrams indicates stellar populations consisting of an old, metal-poor red giant branch (≳12 Gyr, [Fe/H] ∼ –1.7 to –1.9). In addition, CenA-MM-Dw1 seems to host an intermediate-age population as indicated by its candidate asymptotic giant branch stars. The derived luminosities (M{sub V} = –10.9 ± 0.3 for CenA-MM-Dw1 and –8.4 ± 0.6 for CenA-MM-Dw2) and half-light radii (r{sub h} = 1.4 ± 0.04 kpc for CenA-MM-Dw1 and 0.36 ± 0.08 kpc for CenA-MM-Dw2) are consistent with those of Local Group dwarfs. CenA-MM-Dw1's low central surface brightness (μ {sub V,} {sub 0} = 27.3 ± 0.1 mag arcsec{sup –2}) places it among the faintest and most extended M31 satellites. Most intriguingly, CenA-MM-Dw1 and CenA-MM-Dw2 have a projected separation of only 3 arcmin (∼3 kpc): we are possibly observing the first, faint satellite of a satellite in an external group of galaxies.

  16. Shillapoo Wildlife Area, Annual Report 2007-2008.

    SciTech Connect

    Calkins, Brian

    2007-10-01

    This report summarizes accomplishments, challenges and successes on WDFW's Shillapoo Wildlife Area funded under Bonneville Power Administration's (BPA) Wildlife Mitigation Program (BPA project No.2003-012-00) during the Fiscal Year 08 contract period October 1, 2007-September 30, 2008. The information presented here is intended to supplement that contained in BPA's PISCES contract development and reporting system. The organization below is by broad categories of work but references are made to individual work elements in the PISCES Statement of Work as appropriate. Significant progress was realized in almost all major work types. Of particular note was progress made in tree plantings and pasture rehabilitation efforts. This year's tree planting effort included five sites detailed below and in terms of the number of plants was certainly the largest effort on the wildlife area to date in one season. The planting itself took a significant amount of time, which was anticipated. However, installation of mats and tubes took much longer than expected which impacted planned fence projects in particular. Survival of the plantings appears to be good. Improvement to the quality of waterfowl pasture habitats is evident on a number of sites due to replanting and weed control efforts. Continuing long-term weed control efforts will be key in improving this particular type of habitat. A prolonged cold, wet spring and a number of equipment breakdowns presented stumbling blocks that impacted schedules and ultimately progress on planned activities. The unusual spring weather delayed fieldwork on pasture planting projects as well as weed control and slowed the process of maintaining trees and shrubs. This time lag also caused the continued deferral of some of our fencing projects. The large brush hog mower had the driveline break twice and the smaller tractor had an engine failure that caused it to be down for over a month. We have modified our budget plan for next year to include a

  17. Large-Scale Structures in the Zone of Avoidance: The Galactic Anticenter Region

    NASA Technical Reports Server (NTRS)

    Lu, Nanyao Y.; Freudling, Wolfram

    1995-01-01

    We have selected a sample of 876 galaxy candidates from the IRAS Point Source Catalog in the region of 2(exp h) < alpha < 10(exp h) and 0 deg < delta < 36 deg, which crosses the Galactic anticenter part of the Zone of Avoidance (ZOA) and includes most of the highly obscured Orion-Taurus complex region. We have identified galaxies among the candidate sources by attempting to detect the 21 cm H I line of those sources which were not known to be galaxies at the beginning of the survey. In this manner, we constructed a galaxy sample which is largely free from Galactic reddening. Of the 272 observed candidates, 89 were detected in the H I line up to a heliocentric velocity of v(sub h) approximately 16,000 km/s. The resulting galaxy sample of 717 galaxies is fairly complete (within about 10%) and uniform (within about 4%) in the part of the survey area 10 deg away from the Galactic plane and for velocities up to at least 9000 km/s. This provides, for the first time, a largely unbiased view on the large-scale structures in much of the survey area. Our main results are the following: (1) Several large voids are identified. In particular, a void between alpha approximately equals 3(sup h) and 4(sup h), up to v(sub h) approximately 6000 km/s, separates the Pisces-Perseus supercluster at alpha < 3(sup h) from structures at alpha > 4(sup h); and a "nearby void" occupies most of our survey area and reaches out to a redshift of nearly 3000 km/s. (2) We found no nearby galaxy concentration that could significantly contribute to the "Local Velocity Anomoly" (LVA), but a general excess of galaxies around v(sub h) approximately 5000 km/s in the survey area. (3) The contrast between the "Great Wall" at v(sub h) approximately 8500 km/s and the void in front of it appears to gradually diffuse out after it enters the Zone of Avoidance from the northern Galactic hemisphere. (4) Our data combined with other galaxy surveys in or near the Galactic anticenter part of the ZOA suggest that the

  18. Levels of synthesis of primate-specific nuclear proteins differ between growth-arrested and proliferating cells

    SciTech Connect

    Celis, J.E.; Madsen, P.; Nielsen, S.; Ratz, G.P.; Lauridsen, J.B.; Celis, A.

    1987-02-01

    A monoclonal antibody that reacts specifically with the proliferation-sensitive nuclear proteins, isoelectric focusing (IEF) 8Z31 (molecular weight (MW), 76,000 charge variants, HeLa protein catalogue number) has been characterized. As determined by indirect immunofluorescence, the antibody stains the nucleolus and nucleoplasm of interphase-cultured cells of primate origin, but does not react with cells of other species. Proteins having similar MWs and isoelectric points as the human or monkey (primates) proteins were not observed in cultured cells of the following species: aves, bat, dog, dolphin, goat, hamster, mink, mouse, pisces, potoroo, rabbit and rat. Quantitative two-dimensional (2D) gel electrophoretic analysis of (/sup 35/S)methionine-labelled proteins synthesized by normal (quiescent, proliferating) and SV40-transformed human MRC-5 fibroblasts revealed significant differences in the levels of synthesis of both IEF 8Z30 and 8Z31. In quiescent cells the main labelled product corresponded to IEF 8Z31 (ratio IEF 8Z31/8Z30, 2.3), while in the transformed cells the major product was IEF 8Z30 (ratio, 0.62). Normal proliferating fibroblasts exhibited similar levels of both proteins (ratio, 1.21). Combined levels of synthesis of both proteins were 1.50 and 1.20 times as high in the transformed cells as in the quiescent and proliferating cells, respectively. Modulation of the levels of synthesis of these proteins may play a role in cell proliferation.

  19. Copper, zinc and cadmium in benthic organisms from the Java Sea and estuarine and coastal areas around East Java

    NASA Astrophysics Data System (ADS)

    Everaarts, J. M.; Boon, J. P.; Kastoro, W.; Fischer, C. V.; Razak, H.; Sumanta, I.

    A study was made of the concentrations of copper, zinc and cadmium in benthic organisms, representing the phyla Mollusca, Arthropoda, Echinodermata and Pisces, from the riverine and estuarine areas of the rivers Brantas and Solo (East Java) and the adjacent coastal area. Moreover, an assessment was made of the contamination of the benthic biota with these elements in the Java Sea and Bali Sea. Benthic organisms show a species-specific uptake pattern for each element. Compared to the same type of animals from estuaries and coastal areas in temperate regions of western Europe, the concentrations of cadmium are considerably higher, while copper and zinc concentrations are somewhat lower. There is no general trend in concentration levels of the metals in specimens from rivers, estuaries, coastal zone and open sea. In some groups of organisms ( e.g. shrimp, starfish) the concentrations of copper and zinc are highest in specimens from rivers and estuaries. In contrast, cadmium concentration levels in e.g. crab, shrimp and squid are lowest in riverine and estuarine areas. Significant differences in metal concentrations in these organisms were found between the dry monsoon period (July, August) and the beginning of the wet monsoon (November, December). No relationship existed between the metal concentration of the organisms and the silt fraction of the sediment (grain size < 63 μm) or the bulk sediment.

  20. The Sponge Zygomycale parishii(Bowerbank) and its Endobiotic Fauna

    NASA Astrophysics Data System (ADS)

    Duarte, Luiz; Nalesso, Rosebel

    1996-02-01

    The endobiotic fauna of the sponge Zygomycale parishii(Bowerbank) was studied for 2·5 years at two sites, Ubatuba and São Sebastião, on the northern coast of the State of São Paulo, Brazil. Ninety-two macrofaunal species (over 1 mm long) were identified among which Cnidaria, Turbellaria, Nemertinea, Sipuncula, Polychaeta, Mollusca, Crustacea, Pycnogonida, Echinodermata, Ascidiacea and Pisces were represented. The results obtained on the number of species (species richness), the abundances of different species and faunal composition were related to the physico-biotic characteristics of the study sites. The influence of sample volume and other methodological artifacts on sample characteristics were also examined. The ophiuroid Ophiactis savignyi(Müller & Troschell) was the dominant endobiotic species, comprising 64% of all individuals collected. The São Sebastião endobiotic fauna was more diversified than the Ubatuba endobiotic fauna, possibly due to higher larval recruitment, and to the closeness of Z. parishiito the sea-floor providing a greater possibility for inhabitants of this microhabitat to find and to live inside the sponge.

  1. Across the southern Andes on fin: glacial refugia, drainage reversals and a secondary contact zone revealed by the phylogeographical signal of Galaxias platei in Patagonia.

    PubMed

    Zemlak, Tyler S; Habit, Evelyn M; Walde, Sandra J; Battini, Miguel A; Adams, Emily D M; Ruzzante, Daniel E

    2008-12-01

    We employed DNA sequence variation at two mitochondrial (control region, COI) regions from 212 individuals of Galaxias platei (Pisces, Galaxiidae) collected throughout Patagonia (25 lakes/rivers) to examine how Andean orogeny and the climatic cycles throughout the Quaternary affected the genetic diversity and phylogeography of this species. Phylogenetic analyses revealed four deep genealogical lineages which likely represent the initial division of G. platei into eastern and western lineages by Andean uplift, followed by further subdivision of each lineage into separate glacial refugia by repeated Pleistocene glacial cycles. West of the Andes, refugia were likely restricted to the northern region of Patagonia with small relicts in the south, whereas eastern refugia appear to have been much larger and widespread, consisting of separate northern and southern regions that collectively spanned most of Argentinean Patagonia. The retreat of glacial ice following the last glacial maximum allowed re-colonization of central Chile from nonlocal refugia from the north and east, representing a region of secondary contact between all four glacial lineages. Northwestern glacial relicts likely followed pro-glacial lakes into central Chilean Patagonia, whereas catastrophic changes in drainage direction (Atlantic --> Pacific) for several eastern palaeolakes were the likely avenues for invasions from the east. These mechanisms, combined with evidence for recent, rapid and widespread population growth could explain the extensive contemporary distribution of G. platei throughout Patagonia. PMID:19017262

  2. Phylogeography in Galaxias maculatus (Jenyns, 1848) along Two Biogeographical Provinces in the Chilean Coast.

    PubMed

    González-Wevar, Claudio A; Salinas, Pilar; Hüne, Mathias; Segovia, Nicolás I; Vargas-Chacoff, Luis; Astorga, Marcela; Cañete, Juan I; Poulin, Elie

    2015-01-01

    Major geologic and climatic changes during the Quaternary exerted a major role in shaping past and contemporary distribution of genetic diversity and structure of aquatic organisms in southern South America. In fact, the northern glacial limit along the Pacific coast, an area of major environmental changes in terms of topography, currents, and water salinity, represents a major biogeographic transition for marine and freshwater species. We used mitochondrial DNA sequences (D-loop) to investigate the consequences of Quaternary glacial cycles over the pattern of genetic diversity and structure of G. maculatus (Pisces: Galaxiidae) along two biogeographical provinces in the Chilean coast. Extreme levels of genetic diversity and strong phylogeographic structure characterize the species suggesting a low amount of influence of the last glacial cycle over its demography. However, we recognized contrasting patterns of genetic diversity and structure between main biogeographical areas here analyzed. Along the Intermediate Area (38°-41° S) each estuarine population constitutes a different unit. In contrast, Magellanic populations (43°-53° S) exhibited low levels of genetic differentiation. Contrasting patterns of genetic diversity and structure recorded in the species between the analyzed biogeographic areas are consistent with the marked differences in abiotic factors (i.e., different coastal configurations, Quaternary glacial histories, and oceanographic regimes) and to inherent characteristics of the species (i.e., salt-tolerance, physiology, and reproductive behavior). PMID:26161896

  3. Star-Hopping

    NASA Astrophysics Data System (ADS)

    Garfinkle, Robert A.

    1997-07-01

    Introduction; Preface; Acknowledgements; 1. How to use this book and what you are going to see; 2. How the sky works, determining your field of view, observing tips and how to navigate in the night sky; 3. January - Taurus and Orion: the bull and hunter; 4. February - Canis Minor, Canis Major, and Puppis: dog days in February and Jason's Argo; 5. March - Cancer, Leo, and Corvus: a crab, the king of the beasts, and a crow; 6. April - Ursa Major: a dipper round tripper; 7. May - Coma Berenices and Virgo: the sparkling hair of Berenice and the wheat maiden and her bushel of galaxies; 8. June - Libra and Lupus: the balance scales and the wolf; 9. July - Scorpius, Sagittarius, and Scutum: the scorpion, archer, and shield of John Sobieski; 10. August - Draco: following the trail of the dragon; 11. September - Cygnus, Lyra, Vulpecula, and Sagitta: the swan, lyre, fox, and arrow; 12. October - Andromeda and Perseus: the chained lady and her rescuer; 13. November - Cepheus and Cassiopeia: the king and queen of Joppa; 14. December - Pisces, Triangulum, and Aries: of fishes, a triangle, and a ram; 15. Messier Marathon, a sundown to sunup hop across the skies; Appendix A: Classification tables; Appendix B: The constellations; Appendix C: The Greek alphabet; Appendix D: Decimalization of the day; Glossary; Bibliography; Index.

  4. Laniakea, our Home Supercluster of Galaxies

    NASA Astrophysics Data System (ADS)

    Pomarede, Daniel; Courtois, Helene M.; Hoffman, Yehuda; Tully, R. Brent

    2015-08-01

    We report the recent discovery of Laniakea, the supercluster of galaxies that contains the Milky Way. The three-dimensional extent of the supercluster is reconstructed and visualized using the concept of gravitational basin of attraction within which flows of matter are found to converge onto a unique attractor. This has been achieved by exploiting the Cosmicflows-2 Catalog of line-of-sight peculiar velocities of galaxies, that provides data on a scale large enough to circumscribe our supercluster and separate it from the partially reconstructed neighbor superclusters. The intergalactic three-dimensional velocity field, where the Hubble expansion and the long range flows are removed, is reconstructed by the Wiener Filter technique, in the framework of the standard cosmological model, using a Bayesian approach. We characterize the structure and present maps of its cosmography, including 3D visualizations of the frontier surface, configurations of cosmic flows both inside and outside the frontier, contents in known clusters of galaxies, filaments and voids, connections with the local cosmic web, interfaces with the neighboring superclusters Perseus-Pisces, Shapley, Coma, and the newly discovered Arrowhead mini-supercluster of galaxies.

  5. Interaction of high flux deuterium/nitrogen plasmas with beryllium

    NASA Astrophysics Data System (ADS)

    Dittmar, T.; Baldwin, M. J.; Doerner, R. P.; Nishijima, D.; Oberkofler, M.; Schwarz-Selinger, T.; Tabarés, F.

    2011-12-01

    Before nitrogen can be used as a radiator for edge plasma temperature control in experiments with beryllium as the wall material, the compatibility of nitrogen-containing plasma with beryllium has to be tested. Therefore beryllium samples were exposed to a variety of mixed N2/D2 plasmas in PISCES-B and codeposits from the sputtered material were collected. It was found that introducing N2 to a D2 plasma reduces Be erosion significantly but recovery to the pre-N2 levels is possible in pure D2 plasma. Berylliated vessel walls can be a reservoir for N2 and chemical processes probably play a significant role during nitriding and N2 removal. Nitrided target samples remain conductive and do not lead to additional arcing, but codeposits are insulating. Thermal desorption measurements of nitrided and un-nitrided target samples are comparable, while codeposits show a slightly reduced D retention. However, D release for both target and codeposits is shifted ≈100 K to higher temperatures, above 510 K.

  6. How the First Stars Shaped the Faintest Gas-dominated Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Verbeke, R.; Vandenbroucke, B.; De Rijcke, S.

    2015-12-01

    Low-mass dwarf galaxies are very sensitive test-beds for theories of cosmic structure formation since their weak gravitational fields allow the effects of the relevant physical processes to clearly stand out. Up to now, no unified account has existed of the sometimes seemingly conflicting properties of the faintest isolated dwarfs in and around the Local Group, such as Leo T and the recently discovered Leo P and Pisces A systems. Using new numerical simulations, we show that this serious challenge to our understanding of galaxy formation can be effectively resolved by taking into account the regulating influence of the ultraviolet radiation of the first population of stars on a dwarf's star formation rate while otherwise staying within the standard cosmological paradigm for structure formation. These simulations produce faint, gas-dominated, star-forming dwarf galaxies that lie on the baryonic Tully-Fisher relation and that successfully reproduce a broad range of chemical, kinematical, and structural observables of real late-type dwarf galaxies. Furthermore, we stress the importance of obtaining properties of simulated galaxies in a manner as close as possible to the typically employed observational techniques.

  7. Natural variability of marine ecosystems inferred from a coupled climate to ecosystem simulation

    NASA Astrophysics Data System (ADS)

    Le Mézo, Priscilla; Lefort, Stelly; Séférian, Roland; Aumont, Olivier; Maury, Olivier; Murtugudde, Raghu; Bopp, Laurent

    2016-01-01

    This modeling study analyzes the simulated natural variability of pelagic ecosystems in the North Atlantic and North Pacific. Our model system includes a global Earth System Model (IPSL-CM5A-LR), the biogeochemical model PISCES and the ecosystem model APECOSM that simulates upper trophic level organisms using a size-based approach and three interactive pelagic communities (epipelagic, migratory and mesopelagic). Analyzing an idealized (e.g., no anthropogenic forcing) 300-yr long pre-industrial simulation, we find that low and high frequency variability is dominant for the large and small organisms, respectively. Our model shows that the size-range exhibiting the largest variability at a given frequency, defined as the resonant range, also depends on the community. At a given frequency, the resonant range of the epipelagic community includes larger organisms than that of the migratory community and similarly, the latter includes larger organisms than the resonant range of the mesopelagic community. This study shows that the simulated temporal variability of marine pelagic organisms' abundance is not only influenced by natural climate fluctuations but also by the structure of the pelagic community. As a consequence, the size- and community-dependent response of marine ecosystems to climate variability could impact the sustainability of fisheries in a warming world.

  8. Sputtering properties of tungsten 'fuzzy' surfaces

    NASA Astrophysics Data System (ADS)

    Nishijima, D.; Baldwin, M. J.; Doerner, R. P.; Yu, J. H.

    2011-08-01

    Sputtering yields of He-induced W 'fuzzy' surfaces bombarded by Ar have been measured in the linear divertor plasma simulator PISCES-B. It is found that the sputtering yield of a fuzzy surface, Yfuzzy, decreases with increasing fuzzy layer thickness, L, and saturates at ˜10% of that of a smooth surface, Ysmooth, at L > 1 μm. The reduction in the sputtering yield is suspected to be due mainly to the porous structure of fuzz, since the ratio, Yfuzzy/Ysmooth follows (1 - pfuzz), where pfuzz is the fuzz porosity. Further, Yfuzzy/Ysmooth is observed to increase with incident ion energy, Ei. This may be explained by an energy dependent change in the angular distribution of sputtered W atoms, since at lower Ei, the angular distribution is observed to become more butterfly-shaped. That is, a larger fraction of sputtered W atoms can line-of-sight deposit/stick onto neighboring fuzz nanostructures for lower Ei butterfly distributions, resulting in lower ratio of Yfuzzy/Ysmooth.

  9. Predicting the Presence of Large Fish through Benthic Geomorphic Features

    NASA Astrophysics Data System (ADS)

    Knuth, F.; Sautter, L.; Levine, N. S.; Kracker, L.

    2013-12-01

    Marine Protected Areas are critical in sustaining the resilience of fish populations to commercial fishing operations. Using acoustic data to survey these areas promises efficiency, accuracy, and minimal environmental impact. In July, 2013, the NOAA Ship Pisces collected bathymetric, backscatter and water column data for 10 proposed MPA sites along the U.S. Southeast Atlantic continental shelf. A total of 205 km2 of seafloor were mapped between Mayport, FL and Wilmington, NC, using the SIMRAD ME70 and EK60 echosounder systems. These data were processed in Caris HIPS, QPS FMGT, MATLAB and ArcGIS. The backscatter and bathymetry reveal various benthic geomorphic features, including flat sand, rippled sand, and rugose hard bottom. Water column data directly above highly rugose hardbottom contains the greatest counts for large fish populations. Using spatial statistics, such as a geographically weighted regression model, we aim to identify features of the benthic profile, including rugosity, curvature and slope, that can predict the presence of large fish. The success of this approach will greatly expedite fishery surveys, minimize operational cost and aid in making timely management decisions.

  10. Phylogeography in Galaxias maculatus (Jenyns, 1848) along Two Biogeographical Provinces in the Chilean Coast

    PubMed Central

    González-Wevar, Claudio A.; Salinas, Pilar; Hüne, Mathias; Segovia, Nicolás I.; Vargas-Chacoff, Luis; Astorga, Marcela; Cañete, Juan I.; Poulin, Elie

    2015-01-01

    Major geologic and climatic changes during the Quaternary exerted a major role in shaping past and contemporary distribution of genetic diversity and structure of aquatic organisms in southern South America. In fact, the northern glacial limit along the Pacific coast, an area of major environmental changes in terms of topography, currents, and water salinity, represents a major biogeographic transition for marine and freshwater species. We used mitochondrial DNA sequences (D-loop) to investigate the consequences of Quaternary glacial cycles over the pattern of genetic diversity and structure of G. maculatus (Pisces: Galaxiidae) along two biogeographical provinces in the Chilean coast. Extreme levels of genetic diversity and strong phylogeographic structure characterize the species suggesting a low amount of influence of the last glacial cycle over its demography. However, we recognized contrasting patterns of genetic diversity and structure between main biogeographical areas here analyzed. Along the Intermediate Area (38°–41° S) each estuarine population constitutes a different unit. In contrast, Magellanic populations (43°–53° S) exhibited low levels of genetic differentiation. Contrasting patterns of genetic diversity and structure recorded in the species between the analyzed biogeographic areas are consistent with the marked differences in abiotic factors (i.e., different coastal configurations, Quaternary glacial histories, and oceanographic regimes) and to inherent characteristics of the species (i.e., salt-tolerance, physiology, and reproductive behavior). PMID:26161896

  11. The effect of transient temporal pulse shape on surface temperature and tungsten damage

    NASA Astrophysics Data System (ADS)

    Yu, J. H.; De Temmerman, G.; Doerner, R. P.; Pitts, R. A.; van den Berg, M. A.

    2015-09-01

    The plasma-facing components (PFCs) in future fusion devices such as ITER will receive intense transient heat fluxes from plasma instabilities, such as edge localized modes (ELMs) and disruptions, which will limit material lifetime. The energy density and transient pulse duration are typically used to characterize the PFC damage threshold. However, these parameters are not sufficient to define a damage threshold, because different transient pulse shapes with the same energy density and same pulse duration produce different peak surface temperatures (and thus stresses, which ultimately determine material damage). The surface temperature and damage of tungsten (the material to be used for the ITER divertor target armor) in the form of surface roughening and melting are investigated using various temporal pulse shapes from an Nd:YAG laser in the PISCES-B facility. The heat flux factor is examined and shown to be an inadequate parameter to characterize the temperature rise except for square temporal pulse shapes. For ELM-like heat pulses, the long tail in the temporal shape results in a lower peak surface temperature and less damage compared to a symmetric triangle pulse with equal energy density.

  12. conSSert: Consensus SVM Model for Accurate Prediction of Ordered Secondary Structure.

    PubMed

    Kieslich, Chris A; Smadbeck, James; Khoury, George A; Floudas, Christodoulos A

    2016-03-28

    Accurate prediction of protein secondary structure remains a crucial step in most approaches to the protein-folding problem, yet the prediction of ordered secondary structure, specifically beta-strands, remains a challenge. We developed a consensus secondary structure prediction method, conSSert, which is based on support vector machines (SVM) and provides exceptional accuracy for the prediction of beta-strands with QE accuracy of over 0.82 and a Q2-EH of 0.86. conSSert uses as input probabilities for the three types of secondary structure (helix, strand, and coil) that are predicted by four top performing methods: PSSpred, PSIPRED, SPINE-X, and RAPTOR. conSSert was trained/tested using 4261 protein chains from PDBSelect25, and 8632 chains from PISCES. Further validation was performed using targets from CASP9, CASP10, and CASP11. Our data suggest that poor performance in strand prediction is likely a result of training bias and not solely due to the nonlocal nature of beta-sheet contacts. conSSert is freely available for noncommercial use as a webservice: http://ares.tamu.edu/conSSert/ . PMID:26928531

  13. Elliptic grid generation with orthogonality and spacing control on an arbitrary number of boundaries

    NASA Technical Reports Server (NTRS)

    White, J. A.

    1990-01-01

    A procedure for the generation of two and quasi-three-dimensional grids with control of orthogonality and spacing with respect to any and/or all boundaries of the domain is described. The elliptic grid generation equations of Thompson are solved implicitly. Control of the grid behavior is achieved through the introduction of forcing functions terms in the manner of Steger and Sorenson or in a modification of the method of Hilgenstock. The forcing function terms are constructed on the boundaries and propagated into the domain using transfinite Lagrangian bivariate interpolation. An anisotropic transfinite stencil is introduced and is shown to produce excellent grid behavior particularly in the vicinity of corner singularities. Emphasis is placed on the generation of viscous grids and the method is shown to be suited for use in the generation of grids for internal as well as external flow geometries. A FORTRAN program named PISCES has been written to implement the algorithm. Examples of grids for internal and external flows are given that highlight the characteristics and behavior of the algorithm.

  14. Development of assimilative biogeochemical ocean models for operational and research applications

    NASA Astrophysics Data System (ADS)

    Brasseur, Pierre

    The Green-Mercator project (2007-2009, http://mercator-vert.ipsl.jussieu.fr/) aims at implementing the marine biogeochemical model PISCES at global scale into the MERCATOR operational monitoring and forecasting system. Besides the development of the model system itself, this project relies on two major research activities to improve biogeochemical simulations: (1) the refinement of process resolution to investigate the impact of the transition between eddy permitting to eddy resolving on biogeochemical simulations at global scale, and (2) the assimilation of physical and biogeochemical data (such as ocean color) into the model. The project also includes research activities to demonstrate the potential of an operational biogeochemical model for regional downscaling and extension towards marine resources. In this talk, we will focus on developments achieved in the framework of the E.U. MERSEA project (2004-2008) to assimilate satellite and in situ data into coupled models. Experiments using the SEEK filter in a North Atlantic prototype at 1/4° resolution illustrate the feasability of the approach. The results show that traditional methods such as the Kalman filter may lead to physical inconsistencies originating from the gaussian nature of the KF analysis scheme. A new scheme based on truncated gaussian pdfs is therefore developed (TGF) to integrate inequality constraints during the assimilation process. This new scheme represents a major step toward the assimilation of a variety of satellite data, such as sea-ice thickness and ocean colour data, into coupled models.

  15. The Arrowhead Not-So-Supercluster of Galaxies

    NASA Astrophysics Data System (ADS)

    Pomarede, Daniel; Courtois, Helene M.; Hoffman, Yehuda; Tully, R. Brent

    2015-08-01

    Superclusters of galaxies are identified using the concept of three-dimensional basins of attraction enclosing regions of convergence of cosmic flows. The Cosmicflows-2 Catalog of line-of-sight peculiar velocities of galaxies, used as input of a Wiener Filter reconstruction of the 3D velocity flow, is providing new insights on the structure of the Local Universe, in particular in the relationships between our Home Supercluster Laniakea and it neighbor superclusters. Of particular interest is the contact region where the three giant gravitational basins of Laniakea, Perseus-Pisces and Coma share common frontiers along which cosmic flows are shearing apart. By focusing the reconstruction on this particular point, we have identified the existence of a previously unknown basin of attraction of limited volume and size, with characteristic dimension 25 Mpc. This mini-supercluster has a limited content in terms of total number of catalogued galaxies and does not contain any major cluster. The analysis of the flows reveal that this structure is caught in a Tug-of-war situation with its three giant neighbors. The resulting structure displays a topology in the shape of a Stone Age Arrowhead, with three facets oriented toward the basins of attraction of the neighbor superclusters, three edges terminating the frontier lines separating these superclusters, and its two apice pinpointing the centers of nearby voids. We name this structure the Arrowhead Supercluster. We provide three-dimensional maps and visualizations highlighting the cosmography of the Arrowhead and the connection with its environment.

  16. NASA Tech Briefs, June 2010

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Topics covered include: Situational Awareness from a Low-Cost Camera System; Data Acquisition System for Multi-Frequency Radar Flight Operations Preparation; Mercury Toolset for Spatiotemporal Metadata; Social Tagging of Mission Data; Integrating Radar Image Data with Google Maps; Demonstration of a Submillimeter-Wave HEMT Oscillator Module at 330 GHz; Flexible Peripheral Component Interconnect Input/Output Card; Interface Supports Lightweight Subsystem Routing for Flight Applications; MMIC Amplifiers and Wafer Probes for 350 to 500 GHz; Public Risk Assessment Program; Particle Swarm Optimization Toolbox; Telescience Support Center Data System Software; Update on PISCES; Ground and Space Radar Volume Matching and Comparison Software; Web-Based Interface for Command and Control of Network Sensors; Orbit Determination Toolbox; Distributed Observer Network; Computer-Automated Evolution of Spacecraft X-Band Antennas; Practical Loop-Shaping Design of Feedback Control Systems; Fully Printed High-Frequency Phased-Array Antenna on Flexible Substrate; Formula for the Removal and Remediation of Polychlorinated Biphenyls in Painted Structures; Integrated Solar Concentrator and Shielded Radiator; Water Membrane Evaporator; Modeling of Failure for Analysis of Triaxial Braided Carbon Fiber Composites; Catalyst for Carbon Monoxide Oxidation; Titanium Hydroxide - a Volatile Species at High Temperature; Selective Functionalization of Carbon Nanotubes: Part II; Steerable Hopping Six-Legged Robot; Launchable and Retrievable Tetherobot; Hybrid Heat Exchangers; Orbital Winch for High-Strength, Space-Survivable Tethers; Parameterized Linear Longitudinal Airship Model; and Physics of Life: A Model for Non-Newtonian Properties of Living Systems.

  17. Tracing the tidal streams of the Sagittarius dSph, and halo Milky Way features, with carbon-rich long-period variables

    NASA Astrophysics Data System (ADS)

    Huxor, A. P.; Grebel, E. K.

    2015-11-01

    We assemble 121 spectroscopically confirmed halo carbon stars, drawn from the literature, exhibiting measurable variability in the Catalina Surveys. We present their periods and amplitudes, which are used to estimate distances from period-luminosity relationships. The location of the carbon stars - and their velocities when available - allow us to trace the streams of the Sagittarius (Sgr) dwarf spheroidal galaxy. These are compared to a canonical numerical simulation of the accretion of Sgr. We find that the data match this model well for heliocentric distances of 15-50 kpc, except for a virtual lack of carbon stars in the trailing arm just north of the Galactic plane, and there is only tentative evidence of the leading arm south of the plane. The majority of the sample can be attributed to the Sgr accretion. We also find groups of carbon stars which are not part of Sgr; most of which are associated with known halo substructures. A few have no obvious attribution and may indicate new substructure. We find evidence that there may be a structure behind the Sgr leading stream apocentre, at ˜100 kpc, and a more distant extension to the Pisces Overdensity also at ˜100 kpc. We study a further 75 carbon stars for which no good period data could be obtained, and for which NIR magnitudes and colours are used to estimate distances. These data add support for the features found at distances beyond 100 kpc.

  18. Optic chiasm in the species of order Clupeiformes, family Clupeidae: Optic chiasm of Spratelloides gracilis shows an opposite laterality to that of Etrumeus teres

    PubMed Central

    Mogi, Kazue; Misawa, Kazuya; Utsunomiya, Kentaro; Kawada, Yuta; Yamazaki, Toshihisa; Takeuchi, Shigeo; Toyoizumi, Ryuji

    2009-01-01

    In most teleost fishes, the optic nerves decussate completely as they project to the mesencephalic region. Examination of the decussation pattern of 25 species from 11 different orders in Pisces revealed that each species shows a specific chiasmic type. In 11 species out of the 25, laterality of the chiasmic pattern was not determined; in half of the individuals examined, the left optic nerve ran dorsally to the right optic nerve, while in the other half, the right optic nerve was dorsal. In eight other species the optic nerves from both eyes branched into several bundles at the chiasmic point, and intercalated to form a complicated decussation pattern. In the present study we report our findings that Spratelloides gracilis, of the order Clupeiformes, family Clupeidae, shows a particular laterality of decussation: the left optic nerve ran dorsally to the right (n = 200/202). In contrast, Etrumeus teres, of the same order and family, had a strong preference of the opposite (complementary) chiasmic pattern to that of S. gracilis (n = 59/59), revealing that these two species display opposite left–right optic chiasm patterning. As far as we investigated, other species of Clupeiformes have not shown left–right preference in the decussation pattern. We conclude that the opposite laterality of the optic chiasms of these two closely related species, S. gracilis and E. teres, enables investigation of species-specific laterality in fishes of symmetric shapes. PMID:19229672

  19. Cost-Effectiveness of Pazopanib Versus Sunitinib for Renal Cancer in the United States.

    PubMed

    Benedict, Agnes; Ramaswamy, Krishnan; Sandin, Rickard

    2015-09-01

    We write to comment on a recently published study by Delea et al. in the January 2015 issue of JMCP that evaluated the cost-effectiveness (CE) of sunitinib (SU) versus pazopanib (PAZ) as first-line treatment for metastatic renal cell carcinoma (mRCC) from a U.S. third-party payer perspective.1 This analysis was based on COMPARZ and PISCES, clinical trials that compared SU and PAZ2,3 and led the authors to conclude that PAZ is cost-effective (in fact, dominant, according to the base-case results) compared with SU. Such assessment of economic value is clearly important for deciding between therapies to ensure fair access; therefore, we welcome a comparative evaluation of SU and PAZ. However, we believe that some of the key assumptions and inputs used in the model by Delea et al. render their results and conclusions invalid.  Best practice requires that results from a health economic model should reflect the most likely outcomes based on sound methodology and robust evidence for its inputs, as recommended by the International Society of Pharmacoeconomics and Outcomes Research (ISPOR).4 Here, we focus on 2 key areas (utilities and survival modeling) where, in our view, the analysis by Delea et al. falls short of this standard, and a third area (treatment costs) where the basis for the data derived is unclear. PMID:26308230

  20. Exposures of tungsten nanostructures to divertor plasmas in DIII-D

    DOE PAGESBeta

    Rudakov, D. L.; Wong, C. P. C.; Doerner, R. P.; Wright, G. M.; Abrams, T.; Baldwin, M. J.; Boedo, J. A.; Briesemeister, A. R.; Chrobak, C. P.; Guo, H. Y.; et al

    2016-01-22

    Tungsten nanostructures (W-fuzz) prepared in the PISCES-A linear device have been found to survive direct exposure to divertor plasmas in DIII-D. W-fuzz was exposed in the lower divertor of DIII-D using the divertor material evaluation system. Two samples were exposed in lower single null (LSN) deuterium H-mode plasmas. The first sample was exposed in three discharges terminated by vertical displacement event disruptions, and the second in two discharges near the lowered X-point. More recently, three samples were exposed near the lower outer strike point in predominantly helium H-mode LSN plasmas. In all cases, the W-fuzz survived plasma exposure with littlemore » obvious damage except in the areas where unipolar arcing occurred. In conclusion, arcing is effective in W-fuzz removal, and it appears that surfaces covered with W-fuzz can be more prone to arcing than smooth W surfaces.« less

  1. IRAS galaxies at low galactic and high supergalactic latitudes

    SciTech Connect

    Dow, M.W.; Lu, N.Y.; Houck, J.R.; Salpeter, E.E.; Lewis, B.M.

    1988-01-01

    Based on IR colors, 371 IRAS point sources with absolute value of b = 2-16 deg (b = galactic latitude) were selected for study at H I 21 cm as potential galaxies: 25 percent (93) of these sources are galaxies with redshifts less than 8000 km/s based on H I spectra. Most of the detected galaxies are at redshifts between 2000 and 7500 km/s. Fifty-five of these lie in an area about 40 deg away from the junction of the Pisces-Perseus and Lynx-Ursa Major superclusters, and show a distribution of systemic velocities very similar to these superclusters. There is an enhanced density of galaxies near 6000 km/s with galactic longitude l about 40 deg and b about 0 deg. The two regions surveyed, centered at l about 192 deg and l about 54 deg, lie outside the plane of the Local Supercluster and do not show any preference for galaxies with low velocity widths. 16 references.

  2. IRAS galaxies at low galactic and high supergalactic latitudes

    NASA Technical Reports Server (NTRS)

    Dow, M. W.; Lu, N. Y.; Houck, J. R.; Salpeter, E. E.; Lewis, B. M.

    1988-01-01

    Based on IR colors, 371 IRAS point sources with absolute value of b = 2-16 deg (b = galactic latitude) were selected for study at H I 21 cm as potential galaxies: 25 percent (93) of these sources are galaxies with redshifts less than 8000 km/s based on H I spectra. Most of the detected galaxies are at redshifts between 2000 and 7500 km/s. Fifty-five of these lie in an area about 40 deg away from the junction of the Pisces-Perseus and Lynx-Ursa Major superclusters, and show a distribution of systemic velocities very similar to these superclusters. There is an enhanced density of galaxies near 6000 km/s with galactic longitude l about 40 deg and b about 0 deg. The two regions surveyed, centered at l about 192 deg and l about 54 deg, lie outside the plane of the Local Supercluster and do not show any preference for galaxies with low velocity widths.

  3. INTERNATIONAL COLLABORATION ON CO2 SEQUESTRATION

    SciTech Connect

    Howard J. Herzog; E. Eric Adams

    2004-03-01

    After the permit to conduct a field experiment in Norway was revoked on August 22, 2002, we started executing our contingency plan to conduct a cruise at the Loihi Seamount in Hawaii in December 2002. After a few intense months of preparation, the cruise took place on December 3-13, 2002. In total, eight dives were made with the Pisces V submarine. The primary goal of the experiment was to assess the effect of CO{sub 2} on marine organisms. Studies were done using scavenger traps, as well as collecting water samples and surveying the natural CO{sub 2} plume at the Loihi Seamount. This report documents the experiment in more detail as summarized by the various participants. The data was still being analyzed at the end of this reporting period, so no results are reported here. Both papers and a video on the experiment are being prepared. Some related modeling work is presented in an Appendix in the form of a paper submitted to the Journal of Marine Environmental Engineering. The main goal of our work during this reporting period (August 23, 2002-August 23, 2003) was to conduct an experimental cruise at the Loihi Seamount in the Hawaiian Islands. The work included preparation for the cruise, conducting the survey cruise, and analyzing the results. The cruise took place from December 3-13, 2002.

  4. Formation of helium induced nanostructure ‘fuzz’ on various tungsten grades

    NASA Astrophysics Data System (ADS)

    Baldwin, M. J.; Doerner, R. P.

    2010-09-01

    The response of a variety of W material grades to nanostructure 'fuzz' formation is explored. W targets are exposed to He or D 2-0.2He plasmas in PISCES-B at 900-1320 K to below sputter threshold He + ions of energy 25-60 eV for up to 2.2 × 10 4 s. SEM and XPS reveal nanoscopic reorganization of the W surface to a layer of 'fuzz' of porosity ˜90% as determined by a 'fuzz' removal/weight loss method. The variability of 'fuzz' growth is examined at 1120 K for 1 h durations: SR, SC and doped W grades - La 2O 3 (1% wt.), Re (5% and 10% wt.), and TiC (1.5% wt.) developed 2-3 μm thick 'fuzz' layers, while a VPS grade developed a layer 4 μm thick. An RC grade revealed additional 'fuzz' at deep (>100 μm) grain boundaries. However, heat treatment up to 1900 K produced reintegration of 'fuzz' with the bulk and He release at ˜1000 K and ˜1400-1800 K due to depopulation from vacancy complexes.

  5. Air toxics provisions of the Clean Air Act: Potential impacts on energy

    SciTech Connect

    Hootman, H.A.; Vernet, J.E.

    1991-11-01

    This report provides an overview of the provisions of the Clean Air Act and its Amendments of 1990 that identify hazardous air pollutant (HAP) emissions and addresses their regulation by the US Environmental Protection Agency (EPA). It defines the major energy sector sources of these HAPs that would be affected by the regulations. Attention is focused on regulations that would cover coke oven emissions; chromium emission from industrial cooling towers and the electroplating process; HAP emissions from tank vessels, asbestos-related activities, organic solvent use, and ethylene oxide sterilization; and emissions of air toxics from municipal waste combustors. The possible implications of Title III regulations for the coal, natural gas, petroleum, uranium, and electric utility industries are examined. The report discusses five major databases of HAP emissions: (1) TRI (EPA`s Toxic Release Inventory); (2) PISCES (Power Plant Integrated Systems: Chemical Emissions Studies developed by the Electric Power Research Institute); (3) 1985 Emissions Inventory on volatile organic compounds (used for the National Acid Precipitation Assessment Program); (4) Particulate Matter Species Manual (EPA); and (5) Toxics Emission Inventory (National Aeronautics and Space Administration). It also offers information on emission control technologies for municipal waste combustors.

  6. Air toxics provisions of the Clean Air Act: Potential impacts on energy

    SciTech Connect

    Hootman, H.A.; Vernet, J.E.

    1991-11-01

    This report provides an overview of the provisions of the Clean Air Act and its Amendments of 1990 that identify hazardous air pollutant (HAP) emissions and addresses their regulation by the US Environmental Protection Agency (EPA). It defines the major energy sector sources of these HAPs that would be affected by the regulations. Attention is focused on regulations that would cover coke oven emissions; chromium emission from industrial cooling towers and the electroplating process; HAP emissions from tank vessels, asbestos-related activities, organic solvent use, and ethylene oxide sterilization; and emissions of air toxics from municipal waste combustors. The possible implications of Title III regulations for the coal, natural gas, petroleum, uranium, and electric utility industries are examined. The report discusses five major databases of HAP emissions: (1) TRI (EPA's Toxic Release Inventory); (2) PISCES (Power Plant Integrated Systems: Chemical Emissions Studies developed by the Electric Power Research Institute); (3) 1985 Emissions Inventory on volatile organic compounds (used for the National Acid Precipitation Assessment Program); (4) Particulate Matter Species Manual (EPA); and (5) Toxics Emission Inventory (National Aeronautics and Space Administration). It also offers information on emission control technologies for municipal waste combustors.

  7. Simulating Ocean Fertilization: Effectiveness and Unintended Consequences

    SciTech Connect

    Caldeira, K

    2002-11-03

    The primary objectives of this project are to assess, and improve our understanding of: (1) The effectiveness of various proposals to intentionally store carbon in the ocean through fertilization of the surface ocean with iron and/or macronutrients; and (2) Biologically relevant consequences of long-term and extensive ocean fertilization. The PISCES ocean biogeochemistry model, developed at the MPI in Hamburg, Germany, and IPSL in Saclay, France will be used in this study. This model considers Fe, N, P, O{sub 2}, Si, alkalinity, and carbon, in organic and inorganic, dissolved and particulate forms. The model represents diatoms, coccolithophorids, nitrogen fixers, and two classes of zooplankton. This model will be incorporated into the LLNL ocean GCM, which is already being applied to other problems in ocean carbon sequestration. After coupling the ocean biogeochemistry and circulation models, the reliability of this model will be evaluated by comparison to observations. These include observations of natural ecological and biogeochemical variation and observations of small-scale iron fertilization experiments (e.g. SOFeX, IRONEx). This strategy will produce a tested model with predictive capability that we will use to address the following important questions: What is the long-term effectiveness of ocean carbon sequestration via different ocean fertilization strategies? What are the long-term environmental consequences of prolonged or widespread ocean fertilization? What processes need to be included in the models, to better reproduce effects observed in iron fertilization experiments? What should the next experiment measure to better aid the models?

  8. Pleistocene sediments of Lake Baikal: Lithology and stratigraphic correlation

    NASA Astrophysics Data System (ADS)

    Akulov, N. I.; Mashchuk, I. M.; Akulova, V. V.

    2015-01-01

    The Cenozoic sediments of Lake Baikal penetrated by boreholes and investigated by the manned submersible Pisces, as well as coeval deposits cropping out in beach scarps, recovered by mine workings, and drilled in the coastal zone were the object of this investigation. The main attention was paid to Pleistocene bottom sediments penetrated by Borehole BDP-99-2. The investigations included the detailed analysis of the lithology (grain-size composition, immersion mineralogy of light and heavy fractions, X-ray structural analysis of clayey fraction) and palynological assemblages to specify facies features of Cenozoic sediments, correlate all their known stratigraphic units constituting the sedimentary section of the lake with their analogs in the onshore part of the Baikal rift zone, and compile the composite Cenozoic section. The following features of these sediments are noted: (1) as a whole, Pleistocene sediments are characterized by the hydromica-smectite composition of their clayey fraction with an insignificant share of kaoline; (2) the heavy fraction is dominated by the terrigenous epidote-amphibole association poorly resistant to weathering; (3) Pleistocene sediments of the lake contain siderite, vivianite, pyrite, and goethite concretions and micrometeorites, in addition to well-known ferromanganese nodules; (4) the presence of relict palynomorphs in Pleistocene sediments of Baikal is determined by their erosion from Miocene and Pliocene cavernous clays cropping out on underwater slopes of the Posol'skaya Bank and subsequent reburial along with Pleistocene palynological assemblages.

  9. Reef growth and volcanism on the submarine southwest rift zone of Mauna Loa, Hawaii

    USGS Publications Warehouse

    Moore, J.G.; Normark, W.R.; Szabo, B. J.

    1990-01-01

    A marine sampling program, utilizing the PISCES-5 submersible operated by the Hawaii Undersea Research Laboratory (NOAA), has confirmed the presence of a major submerged coral reef offshore from Ka Lae (South Point), Hawaii. The top of the reef is now 150-160 m below sea level. Radiocarbon and Useries dating indicates that it drowned about 13.9 ka by the combined effects of island subsidence (2.5 mm/year) and the rapid rise of sea level at the end of the last glaciation so that the relative submergence rate of more than 10 mm/year exceeded the upward growth rate of the reef. The submerged reef caps the offshore part of the southwest rift-zone ridge of Mauna Loa, which has apparently undergone little volcanic activity offshore since 170 ka, and possibly since 270 ka. This fact suggests that rift zone activity is becoming increasingly restricted toward the upper part of the volcano, a condition possibly heralding the end of the shield-building stage. ?? 1990 Springer-Verlag.

  10. Pattern and scale of geographic variation in environmental sex determination in the Atlantic silverside, Menidia menidia.

    PubMed

    Duffy, Tara A; Hice, Lyndie A; Conover, David O

    2015-08-01

    The Atlantic silverside, Menidia menidia (Pisces: Atherinidae), exhibits an exceptionally high level of clinal variation in sex determination across its geographic range. Previous work suggested linear changes in the level of temperature-dependent sex determination (TSD) with increasing latitude. Based on comparisons at 31 sites encompassing the entire species' range, we find that the change in level of TSD with latitude is instead highly nonlinear. The level of TSD is uniformly high in the south (Florida to New Jersey), then declines rapidly into the northern Gulf of Maine where genotypic sex determination (GSD) predominates and then rebounds to moderate levels of TSD in the northern-most populations of the Gulf of St. Lawrence. Major latitudinal breakpoints occur in central New Jersey (40(o)N) and the northern Gulf of Maine (44(o)N). No populations display pure TSD or GSD. Length of the growing season is the likely agent of selection driving variation in TSD with a threshold at 210 days. Because gene flow among populations is high, such distinct patterns of geographic variation in TSD/GSD are likely maintained by contemporary selection thereby demonstrating the adaptive fine tuning of sex determining mechanisms. PMID:26177746

  11. In silico analyses of COMT, an important signaling cascade of dopaminergic neurotransmission pathway, for drug development of Parkinson's disease.

    PubMed

    Chakraborty, Chiranjib; Pal, Soumen; Doss, C George Priya; Wen, Zhi-Hong; Lin, Chan-Shing

    2012-06-01

    Catechol-O-methyltransferase (COMT) has a vital role for degradation of dopamine, a neurotransmitter, and this dopamine performs an important function in our mental and physical health. The scarcity of dopamine may lead to Parkinson's disease, and inhibition of COMT can stop dopamine metabolism. Here, we have carried out genomics and proteomics analyses of COMT in order to facilitate new inhibitors of COMT. For genomics analyses, we performed codon composition investigation of COMT gene which shows A+T content which is 53.3 %. For proteomics analyses, conservation patterns and residues (highly conserved amino acids GLU64, LEU65, GLY66, CYS69, GLY70, ALA77, GLU90, THR99, SER119, ASP136, LEU140, ASP141, THR164, ASN170, VAL171, and ILE172), binding grooves, binding pockets, binding and conformation with substrate, evaluation of amino acid composition (15 % leucine rich), high scoring hydrophobic segments, high scoring transmembrane segments, tandem and periodic repeats, and disulfide bonds (three numbers), sequence logos (maximum stack height of 3 b and minimum stack height of <0.5 b) have been investigated for COMT protein. Furthermore, using COMT sequences of different species (class Mammalia, class Amphibia, and class Pisces), a phylogenetic tree has been constructed to examine the evolutionary relationship among different species. PMID:22622642

  12. Extending ALFALFA: Reducing L-Band Wide Observations of Optically Selected Galaxies

    NASA Astrophysics Data System (ADS)

    Smith, Evan; O'Donoghue, Aileen A.; Haynes, Martha P.; Koopmann, Rebecca A.; Undergraduate ALFALFA Team

    2016-01-01

    Observations of galaxies in the Virgo Cluster were completed at the Arecibo Observatory in the spring and summer of 2015. 161 targets were observed, selected by photometry criteria such as magnitude and shape from the Sloan Digital Sky Survey. The targets, some too dim to be detected by Arecibo's ALFA drift scanner, were observed with the L-Band Wide detector. Once reductions in an IDL environment were done, these data were matched to the targets from the Sloan Digital Sky Survey and the GALEX/MAST catalog. 115 of the 161 targets observed had positive detections, a 71% success rate. Comparing the galaxies that were detected against the galaxies that were not detected (by the L-Band Wide receiver) will allow us to refine our method of using photometric data to select HI-rich galaxies in the 2000 km/s to 9000 km/s range to refine our selection for the Arecibo Pisces-Perseus Supercluster Survey (APPSS), which uses the same method of target selection.

  13. Cleaning HI Spectra Contaminated by GPS RFI

    NASA Astrophysics Data System (ADS)

    Sylvia, Kamin; Hallenbeck, Gregory L.; Undergraduate ALFALFA Team

    2016-01-01

    The NUDET systems aboard GPS satellites utilize radio waves to communicate information regarding surface nuclear events. The system tests appear in spectra as RFI (radio frequency interference) at 1381MHz, which contaminates observations of extragalactic HI (atomic hydrogen) signals at 50-150 Mpc. Test durations last roughly 20-120 seconds and can occur upwards of 30 times during a single night of observing. The disruption essentially renders the corresponding HI spectra useless.We present a method that automatically removes RFI in HI spectra caused by these tests. By capitalizing on the GPS system's short test durations and predictable frequency appearance we are able to devise a method of identifying times containing compromised data records. By reevaluating the remaining data, we are able to recover clean spectra while sacrificing little in terms of sensitivity to extragalactic signals. This method has been tested on 500+ spectra taken by the Undergraduate ALFALFA Team (UAT), in which it successfully identified and removed all sources of GPS RFI. It will also be used to eliminate RFI in the upcoming Arecibo Pisces-Perseus Supercluster Survey (APPSS).This work has been supported by NSF grant AST-1211005.

  14. Interannual variations in the hatching pattern, larval growth and otolith size of a sand-dwelling fish from central Chile

    NASA Astrophysics Data System (ADS)

    Rodríguez-Valentino, Camilo; Landaeta, Mauricio F.; Castillo-Hidalgo, Gissella; Bustos, Claudia A.; Plaza, Guido; Ojeda, F. Patricio

    2015-09-01

    The interannual variation (2010-2013) of larval abundance, growth and hatching patterns of the Chilean sand stargazer Sindoscopus australis (Pisces: Dactyloscopidae) was investigated through otolith microstructure analysis from samples collected nearshore (<500 m from shore) during austral late winter-early spring off El Quisco bay, central Chile. In the studied period, the abundance of larval stages in the plankton samples varied from 2.2 to 259.3 ind. 1000 m-3; larval abundance was similar between 2010 and 2011, and between 2012 and 2013, but increased significantly from 2011 to 2012. The estimated growth rates increased twice, from 0.09 to 0.21 mm day-1, between 2011 and 2013. Additionally, otolith size (radius, perimeter and area), related to body length of larvae, significantly decreased from 2010 to 2012, but increases significantly in 2013. Although the mean values of microincrement widths of sagitta otoliths were similar between 2010 and 2011 (around 0.6-0.7 μm), the interindividual variability increases in 2011 and 2013, suggesting large environmental variability experienced by larvae during these years. Finally, the hatching pattern of S. australis changed significantly from semi-lunar to lunar cycle after 2012.

  15. [Differences in the infestation rate of young cyprinid fishes (Cypriniformes) by metacercaria of Posthodiplostomum Cuticola (Digenea, Diplostomatidae) in river and lake systems of the Lake Chany basin (Western Siberia)].

    PubMed

    Iadrenkina, E N

    2014-01-01

    A total of 12 fish species were studied for the invasion of P. cuticola (Nordmann, 1832) metacercariae in the Chany Lake estuaries, river and lake systems during different periods of water level. All infected individuals were represented by juveniles of the family Cyprinidae, except for adults of the dace Leuciscus leuciscus. (L.). Under an average water level (2010) the highest rate of fish invasion was revealed in the estuary zone, where the prevalence of infection (PI) constituted 37.5%, 13.4%, and 5.9% for the gudgeon Gobio gobio, the roach Rutilus rutilus (L.), and the dace L. leuciscus (L.), respectively. An infested carp Cyprinus carpio L. (Heckel) (PI - 13.5%) was recorded in the lower Kargat River, and the goldfish Carassius auratus (L.) (PI - 3.2%), in the lake system. Mean intensity of infection (MI) constituted 1.3, 1.4, 2.5, 2.6, and 1.0 in gudgeon, roach, dace, carp, and bream (Abramis brama L.), respectively. During dry season (2011) with high water salinity only two fish species were infected with P. cuticola metacercariae, the goldfish (PI - 7.9%) and the roach (PI - 1.5%). No correlation between PI and fish density was revealed. It is assumed that the high degree of water salinity is a limiting factor regulating the efficiency of cercariae transition from the first intermediate host (Planorbis planorbis (L.)) to the second one (Pisces, Cyprinidae). PMID:25693328

  16. [On the application of Bergmann's rule to ectothermic organisms: the state of the art].

    PubMed

    2013-01-01

    Bergmann's rule (BR) is a classical eco-geographic rule that relates body size of homoiothermal animals with environmental temperature (or latitude). Contemporary data indicate that latitudinal clines in body size, predicted by BR, also exist in ectothermic organisms and in some groups appear to be fairly common. Despite plenty of data from literature, it is still impossible to estimate the frequency of Bergmann's clines occurrence in ectotherms as thoroughly as it is done for homoiotherms. Within large taxa of ectotherms (Arthropoda, Mollusca, Pisces), Bergmann's clines occur alongside with anti-Bergmann's and U-shaped ones. Since classic explanation of BR, which is based on thermoregulation principles, is not applicable to most ectotherms, quite a few hypotheses have been proposed that appeal to other foundations in search of such an explanation. One part of them suggests a direct modifying influence of temperature, though most authors look for adaptive sense in increase of ectotherms size at high latitudes and/or low temperatures. It appears that a single universal explanation of all the cases of Bergmann's variability in ectotherms can not be formulated. Observed clines, as it seems, arise as a result of synergetic interactions between several factors that are covaried with latitude (or altitude above sea level). It is not always possible to estimate the exact contribution of each one of them. PMID:25508096

  17. [On the application of Bergmann's rule to ectothermic organisms: the state of the art].

    PubMed

    Vinarskiĭ, M V

    2013-01-01

    Bergmann's rule (BR) is a classical eco-geographic rule that relates body size of homoiothermal animals with environmental temperature (or latitude). Contemporary data indicate that latitudinal clines in body size, predicted by BR, also exist in ectothermic organisms and in some groups appear to be fairly common. Despite plenty of data from literature, it is still impossible to estimate the frequency of Bergmann's clines occurrence in ectotherms as thoroughly as it is done for homoiotherms. Within large taxa of ectotherms (Arthropoda, Mollusca, Pisces), Bergmann's clines occur alongside with anti-Bergmann's and U-shaped ones. Since classic explanation of BR, which is based on thermoregulation principles, is not applicable to most ectotherms, quite a few hypotheses have been proposed that appeal to other foundations in search of such an explanation. One part of them suggests a direct modifying influence of temperature, though most authors look for adaptive sense in increase of ectotherms size at high latitudes and/or low temperatures. It appears that a single universal explanation of all the cases of Bergmann's variability in ectotherms can not be formulated. Observed clines, as it seems, arise as a result of synergetic interactions between several factors that are covaried with latitude (or altitude above sea level). It is not always possible to estimate the exact contribution of each one of them. PMID:25438565

  18. Facilitation of the Estuary/Ocean Subgroup for Research, Monitoring and Evaluation - FY07 Annual Report.

    SciTech Connect

    Johnson, Gary E.; Diefenderfer, Heida L.

    2007-10-10

    This annual report is a deliverable for fiscal year 2007 (FY07) for Project 2002-077-00, Facilitation of the Estuary/Ocean Subgroup (EOS). The EOS is part of the research, monitoring, and evaluation (RME) effort of the Action Agencies (Bonneville Power Administration, U.S. Army Corps of Engineers, U.S. Bureau of Reclamation) developed in response to responsibilities arising from the Endangered Species Act as a result of operation of the Federal Columbia River Power System (FCRPS). The goal of the EOS project is to facilitate activities of the estuary/ocean RME subgroup as it coordinates design and implementation of federal RME in the lower Columbia River and estuary. In FY07, EOS project accomplishments included (1) subgroup meetings; (2) participation in the estuary work group of the Pacific Northwest Aquatic Monitoring Partnership; (3) project management via the project tracking system, PISCES; (4) quarterly project status reports; and (5) a major revision to the Estuary RME Plan (new version September 2007) based on comments by EOS members and invited reviewers.

  19. Facilitation of the Estuary/Ocean Subgroup for Research, Monitoring, and Evaluation, FY07 Annual Report

    SciTech Connect

    Johnson, Gary E.; Diefenderfer, Heida L.

    2007-10-10

    This annual report is a deliverable for fiscal year 2007 (FY07) for Project 2002-077-00, Facilitation of the Estuary/Ocean Subgroup (EOS). The EOS is part of the research, monitoring, and evaluation (RME) effort the Action Agencies (Bonneville Power Administration, U.S. Army Corps of Engineers, U.S. Bureau of Reclamation) developed in response to responsibilities arising from the Endangered Species Act as a result of operation of the Federal Columbia River Power System (FCRPS). The goal of the EOS project is to facilitate activities of the estuary/ocean RME subgroup as it coordinates design and implementation of federal RME in the lower Columbia River and estuary. In FY07, EOS project accomplishments included 1) subgroup meetings; 2) participation in the estuary work group of the Pacific Northwest Aquatic Monitoring Partnership; 3) project management via the project tracking system, PISCES; 4) quarterly project status reports; and 5) a major revision to the Estuary RME Plan (new version September 2007) based on comments by EOS members and invited reviewers.

  20. Facilitation of the Estuary/Ocean Subgroup for Federal Research, Monitoring and Evaluation FY08 Annual Report.

    SciTech Connect

    Johnson, GE; Diefenderfer, HL

    2008-09-29

    The Estuary/Ocean Subgroup (EOS) is part of the research, monitoring, and evaluation (RME) effort that the Action Agencies (Bonneville Power Administration (BPA), U.S. Army Corps of Engineers, U.S. Bureau of Reclamation) developed in response to obligations arising from the Endangered Species Act as applied to operation of the Federal Columbia River Power System (FCRPS). The goal of the EOS project is to facilitate activities of the estuary/ocean RME subgroup as it coordinates design and implementation of federal RME in the lower Columbia River and estuary. In fiscal year 2008 (FY08), EOS project accomplishments included (1) subgroup meetings; (2) participation in the estuary work group of the Pacific Northwest Aquatic Monitoring Partnership; (3) project management via BPA's project tracking system, Pisces; (4) quarterly project status reports; and (5) a major revision to the Estuary RME document and its subsequent regional release (new version January 2008). Many of the estuary RME recommendations in this document were incorporated into the Biological Opinion on FCRPS operations (May 2008). In summary, the FY08 EOS project resulted in expanded, substantive coordination with other regional RME forums, a new version of the federal Estuary RME program document, and implementation coordination. This annual report is a FY08 deliverable for the project titled Facilitation of the Estuary/Ocean Subgroup.

  1. Facilitation of the Estuary/Ocean Subgroup for Federal Research, Monitoring, and Evaluation, FY08 Annual Report

    SciTech Connect

    Johnson, Gary E.; Diefenderfer, Heida L.

    2008-09-29

    The Estuary/Ocean Subgroup (EOS) is part of the research, monitoring, and evaluation (RME) effort that the Action Agencies (Bonneville Power Administration, U.S. Army Corps of Engineers, U.S. Bureau of Reclamation) developed in response to obligations arising from the Endangered Species Act as applied to operation of the Federal Columbia River Power System (FCRPS). The goal of the EOS project is to facilitate activities of the estuary/ocean RME subgroup as it coordinates design and implementation of federal RME in the lower Columbia River and estuary. In fiscal year 2008 (FY08), EOS project accomplishments included 1) subgroup meetings; 2) participation in the estuary work group of the Pacific Northwest Aquatic Monitoring Partnership; 3) project management via the project tracking system, Pisces; 4) quarterly project status reports; and 5) a major revision to the Estuary RME document and its subsequent regional release (new version January 2008). Many of the estuary RME recommendations in this document were incorporated into the Biological Opinion on hydrosystem operations (May 2008). In summary, the FY08 EOS project resulted in expanded, substantive coordination with other regional RME forums, a new version of the federal Estuary RME program document, and implementation coordination. This annual report is a FY08 deliverable for the project titled Facilitation of the Estuary/Ocean Subgroup.

  2. Desorption of deuterium from beryllium codeposits using flash heating

    NASA Astrophysics Data System (ADS)

    Yu, J. H.; Baldwin, M. J.; Doerner, R. P.; Pitts, R. A.; Smirnov, R. D.; Xu, H. W.

    2013-07-01

    As a result of safety concerns, limits will be placed on the allowable tritium inventory retained inside the ITER vacuum vessel. The primary motivation for the present work is to test the proposed method of removing tritium from main chamber codeposits using radiative heat flashing from controlled ITER plasma shutdowns. Detritiation of Be codeposits is studied in the PISCES-B facility using flash-heating by a 10 ms laser with up to 2 MJ/m2 of absorbed energy density. Three types of codeposits are flash-heated with layer thickness ranging from 0.1 to 1.2 μm. Less than 25% of the D in the Be layer escapes at ITER-relevant flash energy densities and with peak surface temperature up to ˜900 °C. Repetitive flashing with peak surface temperature of 400-500 °C results in an increased population of higher energy trap sites, implying that transient heating which causes appropriate surface temperature excursion redistributes D among codeposit trap sites.

  3. Facilitation of the Estuary/Ocean Subgroup for Research, Monitoring, and Evaluation, FY06 Annual Report

    SciTech Connect

    Johnson, Gary E.

    2006-10-03

    This annual report is a deliverable for fiscal year 2006 (FY06) for Project 2002-077-00, Facilitation of the Estuary/Ocean Subgroup (EOS). The EOS is part of the research, monitoring, and evaluation (RME) effort the Action Agencies (Bonneville Power Administration, U.S. Army Corps of Engineers, U.S. Bureau of Reclamation) developed in response to the 2000 and 2004 Biological Opinions on operation of the Federal Columbia River Power System. The goal of the EOS project is to facilitate activities of the estuary/ocean RME subgroup as it coordinates implementation of the Estuary RME Plan. In FY06, EOS project accomplishments included: 1) subgroup meetings; 2) participation in the estuary work group of the Pacific Northwest Aquatic Monitoring Partnership; 3) project management via the project tracking system, PISCES; 4) quarterly project status reports; and 5) a major revision to the Estuary RME Plan (new version May 2006) based on comments by EOS members, the Independent Scientific Review Panel, and other reviewers. In the context of uncertainty about the direction of the federal RME due to litigation on the FCRPS Biological Opinion, FY06 activities for the EOS project resulted in expanded substantive coordination with other regional RME forums, project tracking infrastructure, and a new version of the Estuary RME Plan.

  4. Integration of Biogeochemistry and Marine Ecosystem Model in Mercator-Ocean Systems

    NASA Astrophysics Data System (ADS)

    El Moussaoui, Abdelali; Dombrowsky, Eric; Moulin, Cyril; Bopp, Laurent; Aumont, Olivier

    2010-05-01

    Accounting for ocean biogeochemistry and marine ecosystem dynamic is of strong interest in the context of Earth System modelling to better represent the marine component to the global atmospheric cycle of greenhouse gazes that influence climate as CO2. Furthermore, treating the ocean as a whole is also the way to address large anthropogenic impacts on marine systems as climate change, nutrients loading, acidification, and eventually overfishing and habitat destructuring. To forecast how interactions between marine biogeochemical cycles and ecosystems respond to and force global change, several efforts have been promoted on biogeochemical integration into operational Mercator Ocean systems. The aim of this work is to implement a marine biogeochemical and ecosystem component at global scale into the MERCATOR operational system, using first PSY3 analysis at 1/4° then PSY4 at 1/12°. Previous works have conducted successfully the integration of a multi-nutrient and multi-plankton biogeochemical model (PISCES, N5P2Z2D2 type) into MERCATOR system. This allowed the use of MERCATOR operational analyses to drive near real time forecast of marine primary production. Results will be shown and advances on biogeochemical model integration within Mercator Systems will be discussed.

  5. A Hero’s Dark Horse: Discovery of an Ultra-faint Milky Way Satellite in Pegasus

    NASA Astrophysics Data System (ADS)

    Kim, Dongwon; Jerjen, Helmut; Mackey, Dougal; Da Costa, Gary S.; Milone, Antonino P.

    2015-05-01

    We report the discovery of an ultra-faint Milky Way satellite galaxy in the constellation of Pegasus. The concentration of stars was detected by applying our overdensity detection algorithm to the SDSS-DR 10 and confirmed with deeper photometry from the Dark Energy Camera at the 4 m Blanco telescope. Fitting model isochrones indicates that this object, Pegasus III, features an old and metal-poor stellar population ([Fe/H] ˜ -2.1) at a heliocentric distance of 205 ± 20 kpc. The new stellar system has an estimated half-light radius of {{r}h}=78-24+30 pc and a total luminosity of {{M}V}˜ -4.1+/- 0.5 that places it into the domain of dwarf galaxies on the size-luminosity plane. Pegasus III is spatially close to the MW satellite Pisces II. It is possible that the two might be physically associated, similar to the Leo IV and Leo V pair. Pegasus III is also well aligned with the Vast Polar Structure, which suggests a possible physical association.

  6. Extremely short lifespan in the annual fish Nothobranchius furzeri.

    PubMed Central

    Valdesalici, Stefano; Cellerino, Alessandro

    2003-01-01

    Evolutionary theories of senescence postulate that lifespan is determined by the age-dependent decrease in the effects of natural selection. Factors that influence survival and reproduction at early life stages have a larger impact on fitness than factors that influence later life stages. According to these views, selection for rapid sexual maturation and a steep age-dependent decrease in fitness drive the evolution of short lifespans. Here, we report on the survival trajectory of Nothobranchius furzeri (Pisces: Ciprinodontidae): a member of a group of annual species found in temporary bodies of water whose life expectancy in the wild is limited to a few months. We find that maximum survival of N. furzeri in the laboratory is less than 12 weeks. The temporal trajectory of survival shows an age-dependent increase in the mortality rate that is typical of organisms with defined lifespans. The lifespan of N. furzeri is exceptionally short for a vertebrate: owing to its small size and the possibility of propagation in captivity, N. furzeri could be used as a convenient model for ageing research. PMID:14667379

  7. Celestial Objects for Common Telescopes

    NASA Astrophysics Data System (ADS)

    Webb, Thomas William

    2010-06-01

    Introduction; Part I. The Instrument and the Observer: 1. The telescope; 2. The mode of observation; Part II. The Solar System: 1. The Sun; 2. Mercury; 3. Venus; 4. The Moon; 5. Index to the map of the moon; 6. Mars; 7. Jupiter; 8. Saturn; 9. Uranus and Neptune; 10. Comets; Part III. The Starry Heavens: 1. Double stars, clusters, and nebulae; 2. Andromeda; 3. Anser; 4. Antinous; 5. Aquarius; 6. Aquila; 7. Argo Navis; 8. Aries; 9. Auriga; 10. Boötes; 11. Camelopardus; 12. Cancer; 13. Canes Venatici; 14. Canis Major; 15. Canis Minor; 16. Capricornus; 17. Cassiopea; 18. Cepheus; 19. Cetus; 20. Clypeus Sobieskii; 21. Coma Berenices; 22. Corona Borealis; 23. Corvus; 24. Crater; 25. Cygnus; 26. Delphinus; 27. Draco; 28. Equuleus; 29. Eridanus; 30. Gemini; 31. Hercules; 32. Hydra; 33. Lacerta; 34. Leo; 35. Leo Minor; 36. Lepus; 37. Libra; 38. Lynx; 39. Lyra; 40. Monoceros; 41. Ophiuchus; 42. Orion; 43. Pegasus; 44. Perseus; 45. Pisces; 46. Sagitta; 47. Sagittarius; 48. Scorpio; Scutum, see Clypeus, Sobieskii; 49. Serpens; 50. Sextans; 51. Taurus; 52. Taurus Poniatowskii; 53. Triangulum; 54. Ursa Major; 55. Ursa Minor; 56. Virgo; 57. Vulpecula.

  8. Vernal Point and Anthropocene

    NASA Astrophysics Data System (ADS)

    Chavez-Campos, Teodosio; Chavez S, Nadia; Chavez-Sumarriva, Israel

    2014-05-01

    proposed as a prime meridian that was based on: (1) the new prime meridian (72º W == 0º) was parallel to the Andes and its projection the meridian (108° E == 180º) intersects the Tibetan plate (Asia). (2) On earth these two areas present the greatest thickness of the crust with an average depth of 70 kilometers. The aim was to synchronize the earth sciences phenomena (e.g. geology, geophysics, etc.). During the Holocene the vernal point retrograde 12,000 years and enters into the Aquarius constellation on March 20, 1940. That date was proposed as the beginning of the Anthropocene because on that date proposed the vernal point passes from the Pisces constellation to Aquarius constellation, besides that event around the date proposed, the Second World War begun. This event was a global change in the earth. The base of the Anthropocene was defined by the passage of the vernal point from the Pisces Constellation to the Aquarius constellation.

  9. The Hawai'i Undersea Research Laboratory: Applying Innovative Deep-sea Technologies Toward Research, Service, and Stewardship in Marine Protected Areas of the Pacific Region

    NASA Astrophysics Data System (ADS)

    Smith, J. R.

    2012-12-01

    The Hawai'i Undersea Research Laboratory (HURL) is the only U.S. deep submergence facility in the Pacific Rim tasked with supporting undersea research necessary to fulfill the mission, goals, and objectives of the National Oceanic and Atmospheric Administration (NOAA), along with other national interests of importance. Over 30 years of submersible operations have resulted in nearly 1900 dives representing 9300 hours underwater, and a benthic ecology database derived from in-house video record logging of over 125,000 entries based on 1100 unique deep-sea animal identifications in the Hawaiian Archipelago. As a Regional Center within the Office of Ocean Exploration and Research (OER), HURL conducts undersea research in offshore and nearshore waters of the main and Northwestern Hawaiian Islands and waters of the central, southern, and western Pacific. HURL facilities primarily support marine research projects that require data acquisition at depths greater than wet diving methods. These consist of the research vessel Ka'imikai-o-Kanaloa (KOK), human occupied submersibles Pisces IV and Pisces V (2000 m), a new remotely operated vehicle (6000 m), and a multibeam bathymetric sonar system (11,000 m). In addition, HURL has also supported AAUS compliant wet diving since 2003, including technical mixed gas/rebreather work. While ecosystem studies of island, atoll, and seamount flanks are the largest component of the HURL science program, many other thematic research areas have been targeted including extreme and unique environments, new resources from the sea, episodic events to long term changes, and the development of innovative technologies. Several examples of HURL's contributions to marine protected areas (MPAs) include: (a) A long term presence in the pristine ecosystems of the Papahānaumokuākea Marine National Monument in the Northwestern Hawaiian Islands. Researchers from National Marine Fisheries have used HURL assets to study endangered Hawaiian Monk Seal habitat

  10. Discoveries From the Cross-Disciplinary, Multi-Institutional South Seas Expedition from Hawaii to New Zealand and Back

    NASA Astrophysics Data System (ADS)

    Malahoff, A.; Wiltshire, J. C.; Smith, J. R.

    2005-12-01

    The Hawaii Undersea Research Laboratory organised an international research team to explore the chemistry, geology, biology, hydrothermal venting processes, mineral deposition, and biodiversity of seamounts extending south from Hawaii to New Zealand, including the submarine volcanoes of the Tonga-Kermadec Island Arc. Research team members came from a Consortium comprising of principal investigators from the NOAA Pacific Marine Environment Lab and VENTS program, the Inst of Geological and Nuclear Sciences and the National Inst of Water and Atmospheric Research both of New Zealand, the Univ of Kiel in Germany, the Univ of Mississippi, Univ of Hawaii, the NOAA Marine Fisheries Service, Scripps Institution of Oceanography, Univ of Oregon, Oregon State Univ, Stanford Univ, and the U.S. Fish and Wildlife Service. Funding came from the member organizations of the Consortium and the NOAA Office of Ocean Exploration and National Undersea Research Program. The expedition left Hawaii on 18 March 2005 and returned on 05 August, aboard the R/V Ka`imikai-o-Kanaloa with the submersibles Pisces IV and Pisces V and the ROV RCV-150. Sixty-one science dives were executed during the eight legs of the expedition. Twelve active volcanoes in the Samoa to New Zealand legs, one in the Samoan hot spot chain and the flanks of five islands and atolls on the legs between Samoa and Hawaii were investigated. Hundreds of specimens of new and unusual marine life, corals and other benthic organisms, extremophile micro- and macro-organisms, water samples for chemical analysis, polymetallic sulfides and rock samples were collected during the expedition. Unusual processes were observed at the Kermadec submarine volcanoes, including the oozing of liquid sulphur onto the seafloor and profuse carbon dioxide venting into seawater. Extensive submarine hydrothermal venting, black smoker activity and extraordinary chimney formations were studied in the caldera of Brothers Volcano. In addition, extensive

  11. Tempest in Vailulu'u Crater

    NASA Astrophysics Data System (ADS)

    Hart, S. R.; Staudigel, H.; Koppers, A.; Young, C.; Baker, E.

    2005-12-01

    The summit crater of the Samoan submarine volcano, Vailulu'u, has been actively erupting since 2001. Based on water chemistry, CTD and temperature logger data from 2000 and 2001, we formulated a model for the hydrothermal system in the crater involving a tidally-modulated "breathing" (Staudigel et al., 2004). During low stands of internal waves (exterior to the crater), the crater exhales warm buoyant hydrothermal water that forms a "halo" around the crater rich in Mn, 3He, and particulates. During "high tides", cold dense external water is inhaled into the crater through the three breaches, and cascades to the crater floor. In April 2005, we used the HURL PISCES V submersible to deploy various temperature and particulate loggers and current meters in and around the crater; these were retrieved by Pisces V in July 2005. In addition, continuous CTD profiling was carried out over 12 hour tidal cycles at one location inside, and one outside, the crater. The accumulated data set fully reinforces our "breathing" model. An ADCP, deployed for 93 days in the NW breach at 752m, showed dominant easterly inflow currents and westerly outflow currents, with maximum velocities of approximately 25 cm/s. The flows were coherent for distances up to 50-60m above the ADCP; the mean inflow velocity and azimuth (20-40 m interval above the ADCP) was 7 cm/s due east; the mean outflow velocity and azimuth was 5 cm/s at 260 degrees. Mean inflows were consistently colder than outflows (5.00 C vs 5.20 C); the maximum observed range in temperature was 1.1 C, correlated with peak flow velocities. The coldest inflows would require very large regional internal wave amplitudes, up to 50-100 meters. A 2-D acoustic current meter was deployed on top of the west crater rim summit (582m) for 90 days, and in the S breach (697m) for 4 days. The summit flows are presumed to represent the regional scale currents; these were largely from the SW quadrant, with typical velocities of 8-15 cm/s, and peaks to

  12. Monitor and Evaluate the Genetic Characteristics of Supplemented Salmon and Steelhead, 2006-2007 Progress Report.

    SciTech Connect

    Berntson, Ewann; Waples, Robin S.; Moran, Paul

    2008-11-20

    been an on-going element of this study, beginning with WDFW's forays into DNA markers in the late 1990s and continuing and becoming more formalized with the initiation of the newer genetics laboratories (CRITFC, USFWS, and IDFG). This report is intended to document success in achieving collection and genotyping goals. Data analyses, presentation, and publication are keeping pace with data collection; however, detailed results are not presented at this time. A complete and comprehensive analysis and description of results will be provided in published manuscripts and in the 2009 annual report (the culmination of the current 3-year rolling review cycle). In the first section of this report, we present accomplishments related to individual projects within this genetic monitoring program. Subsequent to the standard reporting categories, we provide a Specific Obligations section that lists accomplishments exactly as the deliverables are presented in the Pisces Statement of Work. This approach results in a small amount of redundancy, but we try to minimize obvious cases. The goal is to provide our accomplishments in a format that is easily compared to the Work-Element-driven format of Pisces, yet also provide a narrative that shows continuity with the individual studies that make up this research program.

  13. THE ORIGIN OF THE VIRGO STELLAR SUBSTRUCTURE

    SciTech Connect

    Carlin, Jeffrey L.; Yam, William; Willett, Benjamin A.; Newberg, Heidi J.; Casetti-Dinescu, Dana I.; Girard, Terrence M.; Majewski, Steven R.

    2012-07-10

    We present three-dimensional space velocities of stars selected to be consistent with membership in the Virgo stellar substructure. Candidates were selected from SA 103, a single 40' Multiplication-Sign 40' field from our proper-motion (PM) survey in Kapteyn's Selected Areas (SAs), based on the PMs, Sloan Digital Sky Survey (SDSS) photometry, and follow-up spectroscopy of 215 stars. The signature of the Virgo substructure is clear in the SDSS color-magnitude diagram (CMD) centered on SA 103, and 16 stars are identified that have high Galactocentric-frame radial velocities (V{sub GSR} > 50 km s{sup -1}) and lie near the CMD locus of Virgo. The implied distance to the Virgo substructure from the candidates is 14 {+-} 3 kpc. We derive mean kinematics from these 16 stars, finding a radial velocity V{sub GSR} = 153 {+-} 22 km s{sup -1} and proper motions ({mu}{sub {alpha}}cos {delta}, {mu}{sub {delta}}) = (- 5.24, -0.91) {+-} (0.43, 0.46) mas yr{sup -1}. From the mean kinematics of these members, we determine that the Virgo progenitor was on an eccentric (e {approx} 0.8) orbit that recently passed near the Galactic center (pericentric distance R{sub p} {approx} 6 kpc). This destructive orbit is consistent with the idea that the substructure(s) in Virgo originated in the tidal disruption of a Milky Way satellite. N-body simulations suggest that the entire cloud-like Virgo substructure (encompassing the 'Virgo Overdensity' and the 'Virgo Stellar Stream') is likely the tidal debris remnant from a recently disrupted massive ({approx}10{sup 9} M{sub Sun }) dwarf galaxy. The model also suggests that some other known stellar overdensities in the Milky Way halo (e.g., the Pisces Overdensity and debris near NGC 2419 and SEGUE 1) are explained by the disruption of the Virgo progenitor.

  14. Mechanisms behind primary production distribution during the last glacial-interglacial cycle

    NASA Astrophysics Data System (ADS)

    Le Mézo, Priscilla; Kageyama, Masa; Bopp, Laurent; Beaufort, Luc

    2015-04-01

    Reconstructions of past climates are possible through the analysis of organisms contained in marine and terrestrial sediments. Most of the paleorecords depend on biological processes, e.g. production of shells for coccolithophorids in the ocean, and these processes are sensitive to climate fluctuations from seasonal to orbital timescales. Consequently, depending on where and when the organisms that record climate conditions lived in the past, different factors may have influenced their abundance, their functioning, and thus it may bias interpretations of paleodata. In this context, it is necessary to evaluate the response of paleorecorders to climate variability at different timescales. In order to do so, we are using the coupled Earth System Model IPSLCM5A, which has a biogeochemical component PISCES that simulates primary production. We use 9 climate simulations of the IPSL-CM5A model, from -80kyr BP climate conditions to a preindustrial state. Thanks to different forcing conditions of these simulations we are able to disentangle the effects of precession changes from those of obliquity, sea level or gases concentrations. The objectives are to characterize the mechanisms behind the observed changes in primary production between the different time periods. The results of this modeling study will also be compared to reconstructed productions in the Indian, West and East Tropical Pacific Oceans obtained from core sediments with the method described in Beaufort et al. 1997. The early results on seasonal cycles show that, in the Indian Ocean, precession is not the main driver of changes in primary production. Indeed, we observe a grouping between simulations having the same sea level, which suggests that changes in primary production are more sensitive to parameters that define glacial-interglacial conditions such as ice sheets which affect oceanic circulation.

  15. Contrasting Genetic Structure and Diversity of Galaxias maculatus (Jenyns, 1848) Along the Chilean Coast: Stock Identification for Fishery Management.

    PubMed

    González-Wevar, Claudio; Salinas, Pilar; Hüne, Mathias; Segovia, Nicolás; Vargas-Chacoff, Luis; Oda, Esteban; Poulin, Elie

    2015-01-01

    Galaxias maculatus (Pisces: Galaxiidae) commonly known as "puye" has a disjunct distribution along the Southern Hemisphere including landlocked and migratory populations at latitudes over 30°S in South America, Australia, Tasmania, and New Zealand. Chilean artisanal fishery of G. maculatus has become less important as a resource due to multiple factors including overexploitation, pollution, introduction of predators, and competitors. At the same time, the current conservation status of the species in Chile is still uncertain. Here, we used mtDNA control region sequences (925bp) to investigate main patterns of genetic diversity and structure in populations from 2 biogeographic areas along the Chilean coast. Extremely high levels of genetic diversity characterize the species, suggesting a low amount of influence of the last glacial cycle over its demography compared with other studies in freshwater and marine South American fishes. However, we recognized contrasting genetic patterns between the Intermediate Area (between 30°S and 42°S) and the Magellanic Province (between 42°S and 56°S). On the one hand, over a narrow geographical range (<200 km) each Intermediate Area estuarine population constitutes a different genetic unit. On the other hand, the Magellanic populations of the species exhibited low levels of differentiation in an area extending for more than 500 km. Such differences may be a consequence of different coastal configurations, oceanographic regimes, and Quaternary glacial histories. Finally, our results support the existence of different stock units for G. maculatus and this information should be integrated in future management strategies and aquaculture programs for this species. PMID:26245779

  16. Genes meet geology: fish phylogeographic pattern reflects ancient, rather than modern, drainage connections.

    PubMed

    Waters, J M; Craw, D; Youngson, J H; Wallis, G P

    2001-09-01

    We used DNA analysis of the freshwater Galaxias vulgaris complex (Pisces: Galaxiidae) to test a geological hypothesis of drainage evolution in South Island, New Zealand. Geological evidence suggests that the presently north-flowing Nevis River branch of the Clutha/Kawarau River system (Otago) once flowed south into the Nokomai branch of the Mataura system (Southland). The flow reversal is thought to have resulted from fault and fold activity associated with post-Miocene uplift. Mitochondrial DNA sequence data (control region and cytochrome b genes; 76 individuals; maximum divergence 7.1%) corroborate this geomorphological hypothesis: The Nevis River retains a freshwater fish species (Galaxias gollumoides; five sites; 10 haplotypes) that is otherwise restricted to Southland (nine sites; 15 haplotypes). There is no indication that the Nevis River lineage of G. gollumoides lives elsewhere in the Clutha/ Kawarau system (> 30 sites). Likewise, two widespread Clutha lineages (G. 'sp D'; G. anomalus-G. pullus) are apparently absent from the Nevis (> 30 sites). In particular, G. 'sp D' lives throughout much of the Clutha (12 sites, 23 haplotypes), including a tributary of the Kawarau, but is absent from the Nevis itself. Conventional molecular clock calibrations (based on a minimum Nevis-Mataura haplotype divergence of 3.0%) indicate that the Nevis flow reversal may have occurred in the early-mid Pleistocene, which is roughly consistent with geological data. The broad phylogeographic structure evident in the Clutha system is consistent with the sedentary nature of nonmigratory galaxiids. Our study reinforces the value of combining biological and geological data for the formulation and testing of historical hypotheses. PMID:11681739

  17. Panoramic Views of Cluster Evolution Since z = 3

    NASA Astrophysics Data System (ADS)

    Kodama, Tadayuki; Tanaka, M.; Tanaka, Ichi; Kajisawa, M.

    2007-05-01

    We have been conducting PISCES project (Panoramic Imaging and Spectroscopy of Cluster Evolution with Subaru) with making use of the wide-field imaging capability of Subaru. Our motivations are first to map out large scale structure and local environment of galaxies therein, and then to investigate the variation in galaxy properties as a function of environment and mass. We have completed multi-colour imaging of 8 distant clusters between 0.42) by wide-field near-infrared imaging of proto-clusters around radio loud galaxies, some of which are known to show a large number of Lya/Ha emitters at the same redshift of the radio galaxies. We have seen clear excess of near-infrared selected galaxies (including DRG) around many of the radio galaxies, suggesting that these are indeed likely to be proto-clusters with not only young emitters but also evolved populations. Spatial distribution of such NIR selected galaxies is filamentary and track similar structures traced by the emitters, but showing little individual overlap. The above two wide-field studies of dense environments and their surroundings will tell us galaxy evolution during the course of cluster assembly over more than 80 per cent of the age of the Universe.

  18. Galaxy Evolution Viewed as Functions of Environment and Mass

    NASA Astrophysics Data System (ADS)

    Kodama, Tadayuki; Tanaka, Masayuki; Tanaka, Ichi; Kajisawa, Masaru

    We present two large surveys of distant clusters currently being carried out with Subaru, making use of its great capability of wide-field study both in the optical and in the near-infrared. The optical surveys, called PISCES, have mapped out large scale structures in and around 8 distant clusters at 0.4 < z <1.3, composed of multiple filaments and clumps extended over 15-30 Mpc scale. From the photometric and spectroscopic properties of galaxies over a wide range in environment, we find that the truncation of galaxies is seen in the outskirts of clusters rather than in the cluster cores.We also see a clear environmental dependence of the down-sizing (progressively later quenching of star formation in smaller galaxies). The near-infrared surveys are being conducted with a new wide-field instrument targeting proto-clusters around high-zradio-loud galaxies up to z ~4. Most of these field are known to show a large number of Lyαand/or Hαemitters at the same redshifts of the radio galaxies. We see a clear excess of near-infrared selected galaxies (JHK s -selected galaxies as well as DRG) in these fields, and they are indeed proto-clusters with not only young emitters but also evolved populations. Spatial distribution of such NIR selected galaxies is filamentary and track similar structures traced by the emitters. There is an hint that the bright-end of the red sequence first appeared between z= 3 and 2.

  19. Coastal-ocean uptake of anthropogenic carbon

    NASA Astrophysics Data System (ADS)

    Bourgeois, Timothée; Orr, James C.; Resplandy, Laure; Terhaar, Jens; Ethé, Christian; Gehlen, Marion; Bopp, Laurent

    2016-07-01

    Anthropogenic changes in atmosphere-ocean and atmosphere-land CO2 fluxes have been quantified extensively, but few studies have addressed the connection between land and ocean. In this transition zone, the coastal ocean, spatial and temporal data coverage is inadequate to assess its global budget. Thus we use a global ocean biogeochemical model to assess the coastal ocean's global inventory of anthropogenic CO2 and its spatial variability. We used an intermediate resolution, eddying version of the NEMO-PISCES model (ORCA05), varying from 20 to 50 km horizontally, i.e. coarse enough to allow multiple century-scale simulations but finer than coarse-resolution models (˜ 200 km) to better resolve coastal bathymetry and complex coastal currents. Here we define the coastal zone as the continental shelf area, excluding the proximal zone. Evaluation of the simulated air-sea fluxes of total CO2 for 45 coastal regions gave a correlation coefficient R of 0.8 when compared to observation-based estimates. Simulated global uptake of anthropogenic carbon results averaged 2.3 Pg C yr-1 during the years 1993-2012, consistent with previous estimates. Yet only 0.1 Pg C yr-1 of that is absorbed by the global coastal ocean. That represents 4.5 % of the anthropogenic carbon uptake of the global ocean, less than the 7.5 % proportion of coastal-to-global-ocean surface areas. Coastal uptake is weakened due to a bottleneck in offshore transport, which is inadequate to reduce the mean anthropogenic carbon concentration of coastal waters to the mean level found in the open-ocean mixed layer.

  20. Properties of an H I-selected galaxy sample

    NASA Technical Reports Server (NTRS)

    Szomoru, Arpad; Guhathakurta, Puragra; Van Gorkom, Jacqueline H.; Knapen, Johan H.; Weinberg, David H.; Fruchter, Andrew S.

    1994-01-01

    We analyze the properties of a sample of galaxies identified in a 21cm, H I-line survey of selected areas in the Perseus-Pisces supercluster and its foreground void. Twelve fields were observed in the supercluster, five of them (target fields) centered on optically bright galaxies, and the other seven (blank fields) selected to contain no bright galaxies within 45 min. of their centers. We detected nine previously uncatalogued, gas-rich galaxies, six of them in the target fields. We also detected H I from seven previously catalogued galaxies in these fields. Observations in the void covered the same volume as the 12 supercluster fields at the same H I-mass sensitivity, but no objects were detected. Combining out H I data with optical broadband and H alpha imaging, we conclude that the properties of H I-selected galaxies do not differ substantially from those of late-type galaxies found in optical surveys. In particular, the galaxies in our sample do not appear to be unusually faint for their H I mass, or for their circular velocity. We find tentative evidence for a connection between optical surface brightness and degree of isolation, in the sense that low surface brightness galaxies tend to be more isolated. The previously catalogued, optically bright galaxies in our survey volume dominate the total H I mass density and cross section; the uncatalogued galaxies contribute only approximately 19 percent of the mass and approximately 12 percent of the cross section. Thus, existing estimates of the density and cross section of neutral hydrogen, most of which are based on optically selected galaxy samples, are probably accurate. Such estimates can be used to compare the nearby universe to the high-redshift universe probed by quasar absorption lines.

  1. C/sup 13/-depleted authigenic carbonate buildups from hydrocarbon seeps, Louisiana Continental Slope

    SciTech Connect

    Roberts, H.H.; Sassen, R.; Aharon, P.; Carney, R.

    1989-03-01

    Geohazard and geochemical survey data consisting of high-resolution profiles, side-scale sonographs, drop cores, dredge samples, and borings have substantiated the consistent association between carbonate buildups and hydrocarbon seeps on the Louisiana continental slope. Analyses indicate a range of carbonate mineralogies including aragonite, Mg-calcite, and dolomite that are extremely depleted in the C/sup 13/ isotope (/approximately/dC/sup 13/ values to /minus/48/per thousand/ PDB). Microbial oxidation of methane (biogenic and thermogenic) and crude oil creates a source of pore water CO/sub 2/ containing isotopically light carbon, which triggers carbonate precipitation. Geophysical and geochemical evidence suggests that both surface and subsurface lithification is taking place. Recent observations and samples collected using a Pisces class research submersible confirm the abundance of C/sup 13/-depleted sedimentary carbonates and massive authigenic buildups associated with the tops and flanks of shallow salt diapirs and gas hydrate hills. Although chemosynthetic communities (including tube worms and bivalves) with isotopically light carbon in tissues have been described from gas seeps, bacterial mats sampled from several seep areas using a submersible have /delta/C/sup 13/ values of /minus/28 to /minus/ /per thousand/ PDB, suggesting a crude oil contribution to microbial biomass. Lithoherms 15 m in vertical dimension are not unusual on dome crests. These features dominate mesoscale sea-floor topography on the slope and have important short-term impacts on platform locations as well as pipeline routing. They are of long-term importance as sites for low sea level reefs. Moreover, these observations provide new insight into the earliest stages of salt-dome cap-rock evolution.

  2. The Origin of the Virgo Stellar Substructure

    NASA Astrophysics Data System (ADS)

    Carlin, Jeffrey L.; Yam, William; Casetti-Dinescu, Dana I.; Willett, Benjamin A.; Newberg, Heidi J.; Majewski, Steven R.; Girard, Terrence M.

    2012-07-01

    We present three-dimensional space velocities of stars selected to be consistent with membership in the Virgo stellar substructure. Candidates were selected from SA 103, a single 40' × 40' field from our proper-motion (PM) survey in Kapteyn's Selected Areas (SAs), based on the PMs, Sloan Digital Sky Survey (SDSS) photometry, and follow-up spectroscopy of 215 stars. The signature of the Virgo substructure is clear in the SDSS color-magnitude diagram (CMD) centered on SA 103, and 16 stars are identified that have high Galactocentric-frame radial velocities (V GSR > 50 km s-1) and lie near the CMD locus of Virgo. The implied distance to the Virgo substructure from the candidates is 14 ± 3 kpc. We derive mean kinematics from these 16 stars, finding a radial velocity V GSR = 153 ± 22 km s-1 and proper motions (μαcos δ, μδ) = (- 5.24, -0.91) ± (0.43, 0.46) mas yr-1. From the mean kinematics of these members, we determine that the Virgo progenitor was on an eccentric (e ~ 0.8) orbit that recently passed near the Galactic center (pericentric distance Rp ~ 6 kpc). This destructive orbit is consistent with the idea that the substructure(s) in Virgo originated in the tidal disruption of a Milky Way satellite. N-body simulations suggest that the entire cloud-like Virgo substructure (encompassing the "Virgo Overdensity" and the "Virgo Stellar Stream") is likely the tidal debris remnant from a recently disrupted massive (~109 M ⊙) dwarf galaxy. The model also suggests that some other known stellar overdensities in the Milky Way halo (e.g., the Pisces Overdensity and debris near NGC 2419 and SEGUE 1) are explained by the disruption of the Virgo progenitor.

  3. The ISRU Field Tests 2010 and 2012 at Mauna Kea, Hawaii: Results from the Miniaturised Mossbauer Spectrometers Mimos II and Mimos IIA

    NASA Technical Reports Server (NTRS)

    Klingelhoefer, G.; Morris, R. V.; Blumers, M; Bernhardt, B.; Graff, T.

    2014-01-01

    The 2010 and 2012 In-Situ Resource Utilization Analogue Test (ISRU) [1] on the Mauna Kea volcano in Hawai'i was coordinated by the Northern Centre for Advanced Technology (NORCAT) in collaboration with the Canadian Space Agency (CSA), the German Aerospace Center (DLR), and the National Aeronautics and Space Administration (NASA), through the PISCES program. Several instruments were tested as reference candidates for future analogue testing at the new field test site at the Mauna Kea volcano in Hawai'i. The fine-grained, volcanic nature of the material is a suitable lunar and martian analogue, and can be used to test excavation, site preparation, and resource utilization techniques. The 2010 location Pu'u Hiwahine, a cinder cone located below the summit of Mauna Kea (19deg45'39.29" N, 155deg28'14.56" W) at an elevation of 2800 m, provides a large number of slopes, rock avalanches, etc. to perform mobility tests, site preparation or resource prospecting. Besides hardware testing of technologies and systems related to resource identification, also in situ science measurements played a significant role in integration of ISRU and science instruments. For the advanced Mössbauer instrument MIMOS IIA, the new detector technologies and electronic components increase sensitivity and performance significantly. In combination with the high energy resolution of the SDD it is possible to perform Xray fluorescence analysis simultaneously to Mössbauer spectroscopy. In addition to the Fe-mineralogy, information on the sample's elemental composition will be gathered. The 2010 and 2012 field campaigns demonstrated that in-situ Mössbauer spectroscopy is an effective tool for both science and feedstock exploration and process monitoring. Engineering tests showed that a compact nickel metal hydride battery provided sufficient power for over 12 hr of continuous operation for the MIMOS instruments.

  4. Missing baryons traced by the galaxy luminosity density in large-scale WHIM filaments

    NASA Astrophysics Data System (ADS)

    Nevalainen, J.; Tempel, E.; Liivamägi, L. J.; Branchini, E.; Roncarelli, M.; Giocoli, C.; Heinämäki, P.; Saar, E.; Tamm, A.; Finoguenov, A.; Nurmi, P.; Bonamente, M.

    2015-11-01

    We propose a new approach to the problem of the missing baryons. Building on the common assumption that the missing baryons are in the form of the warm hot intergalactic medium (WHIM), we also assume here that the galaxy luminosity density can be used as a tracer of the WHIM. This last assumption is supported by our discovery of a significant correlation between the WHIM density and the galaxy luminosity density in recent hydrodynamical simulations. We also found that the percentage of the gas mass in the WHIM phase is substantially higher (by a factor of ~1.6) within large-scale galactic filaments, i.e. ~70%, compared to the average in the full simulation volume of ~0.1 Gpc3. The relation between the WHIM overdensity and the galaxy luminosity overdensity within the galactic filaments is consistent with a linear one: δwhim = 0.7 ± 0.1 × δLD0.9±0.2. We then applied our procedure to the line of sight towards the blazar H2356-309 and found evidence of WHIM that corresponds to the Sculptor Wall (SW) (z ~ 0.03 and log NH = 19.9+ 0.1-0.3) and Pisces-Cetus (PC) superclusters (z ~ 0.06 and log NH = 19.7+ 0.2-0.3), in agreement with the redshifts and column densities of the X-ray absorbers identified recently. This agreement indicates that the galaxy luminosity density and galactic filaments are reliable signposts for the WHIM and that our method is robust for estimating WHIM density. The signal that we detected cannot originate in the halos of nearby galaxies because they cannot account for the high WHIM column densities that our method and X-ray analysis consistently find in the SW and PC superclusters. Appendix A is available in electronic form at http://www.aanda.org

  5. The origin of Phoxinus eos-neogaeus unisexual hybrids.

    PubMed

    Angers, Bernard; Schlosser, Isaac J

    2007-11-01

    Phoxinus eos-neogaeus unisexual hybrids (Cyprinidae, Pisces) are among the few vertebrate taxa known to reproduce clonally by gynogenesis. These taxa have a broad distribution in North America, mostly located in regions previously covered by the last Pleistocene ice sheet. To assess whether asexual hybrids dispersed from glacial refuges at the end of the Pleistocene or they originated from current hybridization events, genetic diversity of mitochondrial DNA (mtDNA) sequences and microsatellite loci was determined in populations from 16 different sites in the Mississippi-Missouri River (Nebraska and Montana), Rainy River-Hudson Bay (Minnesota), and St Lawrence River (Quebec) drainages. The maternal species (P. neogaeus) occurred in Minnesota and Nebraska but was absent from Montana sites and was restricted to only two of 11 lakes sampled in Quebec, although hybrids were present at all sites. The genetic survey revealed a total of 49 clones, originating from 14 hybridization events. Several of the lineages were characterized by mtDNA haplotypes not detected in the maternal ancestor. Lineages as well as clones frequently displayed a large geographical distribution at a regional scale. Dating of hybridization events suggested a relatively recent origin (<50,000 years ago) from the Mississippi glacial refuge, even in regions not covered by the last Pleistocene glacier. Altogether, these results indicate P. eos-neogaeus hybrids are not the result of current hybridization events, but display a pattern predicted by postglacial dispersal. Our findings have considerable implications for the nature of selection processes affecting the diversity of these asexual taxa and their coexistence with sexual ancestors. PMID:17892466

  6. FIRST LIGHT LBT AO IMAGES OF HR 8799 bcde AT 1.6 AND 3.3 {mu}m: NEW DISCREPANCIES BETWEEN YOUNG PLANETS AND OLD BROWN DWARFS

    SciTech Connect

    Skemer, Andrew J.; Hinz, Philip M.; Rodigas, Timothy J.; Close, Laird; McCarthy, Don; Kulesa, Craig; Apai, Daniel; Bailey, Vanessa; Esposito, Simone; Arcidiacono, Carmelo; Mannucci, Filippo; Agapito, Guido; Argomedo, Javier; Briguglio, Runa; Burrows, Adam; Leisenring, Jarron; Skrutskie, Michael; Desidera, Silvano; Mesa, Dino; Boutsia, Konstantina; and others

    2012-07-01

    As the only directly imaged multiple planet system, HR 8799 provides a unique opportunity to study the physical properties of several planets in parallel. In this paper, we image all four of the HR 8799 planets at H band and 3.3 {mu}m with the new Large Binocular Telescope adaptive optics system, PISCES, and LBTI/LMIRCam. Our images offer an unprecedented view of the system, allowing us to obtain H and 3.3 {mu}m photometry of the innermost planet (for the first time) and put strong upper limits on the presence of a hypothetical fifth companion. We find that all four planets are unexpectedly bright at 3.3 {mu}m compared to the equilibrium chemistry models used for field brown dwarfs, which predict that planets should be faint at 3.3 {mu}m due to CH{sub 4} opacity. We attempt to model the planets with thick-cloudy, non-equilibrium chemistry atmospheres but find that removing CH{sub 4} to fit the 3.3 {mu}m photometry increases the predicted L' (3.8 {mu}m) flux enough that it is inconsistent with observations. In an effort to fit the spectral energy distribution of the HR 8799 planets, we construct mixtures of cloudy atmospheres, which are intended to represent planets covered by clouds of varying opacity. In this scenario, regions with low opacity look hot and bright, while regions with high opacity look faint, similar to the patchy cloud structures on Jupiter and L/T transition brown dwarfs. Our mixed-cloud models reproduce all of the available data, but self-consistent models are still necessary to demonstrate their viability.

  7. Uranium-series dating and growth characteristics of the deep-sea scleractinian coral: Enallopsammia rostrata from the Equatorial Pacific

    NASA Astrophysics Data System (ADS)

    Houlbrèque, Fanny; McCulloch, Malcolm; Roark, Brendan; Guilderson, Tom; Meibom, Anders; Kimball, Justine; Mortimer, Graham; Cuif, Jean-Pierre; Dunbar, Robert

    2010-04-01

    The deep-sea coral, Enallopsammia rostrata, a member of the Dendrophylliidae family, is a major structure-forming species that creates massive dendroid colonies, up to 1 m wide and 0.5 m tall. Living colonies of E. rostrata have been collected using the PISCES submersibles from three locations from 480 to 788 m water depth in the Line Islands (˜160°W) in the Equatorial Pacific. We have applied to these colonies a high sensitivity, low blank technique to determine U-series ages in small quantities (70 ± 15 mg) of modern and near modern calcareous skeletons using MC-ICP-MS (Multi-collector Inductively Coupled Plasma Mass Spectrometer). The application of this method to living slow-growing colonies from a range of sites as well as the observations of axial growth patterns in thin sections of their skeletons offer the first expanded and well constrained data on longevity, growth pattern and mean growth rates in E. rostrata. Absolute dated specimens indicate life spans of colonies ranging from 209 ± 8 yrs to 605 ± 7 yrs with radial growth rates from 0.012 to 0.072 mm yr -1 and vertical extension rates from 0.6 to 1.9 mm yr -1. The linear growth rates reported here are lower than those reported for other deep-sea scleractinian corals ( Lophelia pertusa and Madrepora oculata). The U-series dating indicates that the growth ring patterns of E. rostrata are not consistent with annual periodicity emphasizing the importance of absolute radiometric dating methods to constrain growth rates. Slow accretion and extreme longevity make this species and its habitat especially vulnerable to disturbances and impacts from human activities. This dating method combined with observation of growth patterns opens up new perspectives in the field of deep-sea corals since it can provide quantitative estimates of growth rates and longevity of deep-sea corals in general.

  8. Evaluation of an operational ocean model configuration at 1/12° spatial resolution for the Indonesian seas - Part 2: Biogeochemistry

    NASA Astrophysics Data System (ADS)

    Gutknecht, E.; Reffray, G.; Gehlen, M.; Triyulianti, I.; Berlianty, D.; Gaspar, P.

    2015-08-01

    In the framework of the INDESO (Infrastructure evelopment of Space Oceanography) project, an operational ocean forecasting system was developed to monitor the state of the Indonesian seas in terms of circulation, biogeochemistry and fisheries. This forecasting system combines a suite of numerical models connecting physical and biogeochemical variables to population dynamics of large marine predators (tunas). The physical/biogeochemical coupled component (INDO12BIO configuration) covers a large region extending from the western Pacific Ocean to the Eastern Indian Ocean at 1/12° resolution. The OPA/NEMO physical ocean model and the PISCES biogeochemical model are coupled in "on-line" mode without degradation in space and time. The operational global ocean forecasting system (1/4°) operated by Mercator Ocean provides the physical forcing while climatological open boundary conditions are prescribed for the biogeochemistry. This paper describes the skill assessment of the INDO12BIO configuration. Model skill is assessed by evaluating a reference hindcast simulation covering the last 8 years (2007-2014). Model results are compared to satellite, climatological and in situ observations. Diagnostics are performed on chlorophyll a, primary production, mesozooplankton, nutrients and oxygen. Model results reproduce the main characteristics of biogeochemical tracer distributions in space and time. The seasonal cycle of chlorophyll a is in phase with satellite observations. The northern and southern parts of the archipelago present a distinct seasonal cycle, with higher chlorophyll biomass in the southern (northern) part during SE (NW) monsoon. Nutrient and oxygen concentrations are correctly reproduced in terms of horizontal and vertical distributions. The biogeochemical content of water masses entering in the archipelago as well as the water mass transformation across the archipelago conserves realistic vertical distribution in Banda Sea and at the exit of the archipelago.

  9. THE ARECIBO LEGACY FAST ALFA SURVEY. V. THE H I SOURCE CATALOG OF THE ANTI-VIRGO REGION AT {delta} = +27{sup 0}

    SciTech Connect

    Saintonge, Amelie; Giovanelli, Riccardo; Haynes, Martha P.; Kent, Brian R.; Martin, Ann M.; Stierwalt, Sabrina E-mail: bkentastro@cornell.edu E-mail: sabrina@astro.cornell.edu E-mail: haynes@astro.cornell.edu

    2008-02-15

    We present a second catalog of H I sources detected in the Arecibo Legacy Fast ALFA Survey. We report 488 detections over 135 deg{sup 2}, within the region of the sky having 22 h < {alpha} < 03 h and +26{sup 0} < {delta} < +28{sup 0}. We present here the detections that have either (a) S/N>6.5, where the reliability of the catalog is better than 95% or (b) 5.0 < S/N < 6.5 and a previously measured redshift that corroborates our detection. Of the 488 objects presented here, 49 are high-velocity clouds or clumps thereof with negative heliocentric recession velocities. These clouds are mostly very compact and isolated, while some of them are associated with large features such as Wright's Cloud or the northern extension of the Magellanic Stream. The remaining 439 candidate detections are identified as extragalactic objects and have all been matched with optical counterparts. Five of the six galaxies detected with M{sub Hi}<10{sup 7.5} M{sub sun} are satellites of either the NGC672/IC1727 nearby galaxy pair or their neighboring dwarf irregular galaxy NGC784. The data of this catalog release include a slice through the Pisces-Perseus foreground void, a large nearby underdensity of galaxies. We report no detections within the void, where our catalog is complete for systems with H i masses of 10{sup 8} M{sub sun}. Gas-rich, optically-dark galaxies do not seem to constitute an important void population, and therefore do not suffice for producing a viable solution to the void phenomenon.

  10. Carbon balance of China constrained by CONTRAIL aircraft CO2 measurements

    NASA Astrophysics Data System (ADS)

    Jiang, F.; Wang, H. M.; Chen, J. M.; Machida, T.; Zhou, L. X.; Ju, W. M.; Matsueda, H.; Sawa, Y.

    2014-09-01

    Terrestrial carbon dioxide (CO2) flux estimates in China using atmospheric inversion method are beset with considerable uncertainties because very few atmospheric CO2 concentration measurements are available. In order to improve these estimates, nested atmospheric CO2 inversion during 2002-2008 is performed in this study using passenger aircraft-based CO2 measurements over Eurasia from the Comprehensive Observation Network for Trace gases by Airliner (CONTRAIL) project. The inversion system includes 43 regions with a focus on China, and is based on the Bayesian synthesis approach and the TM5 transport model. The terrestrial ecosystem carbon flux modeled by the Boreal Ecosystems Productivity Simulator (BEPS) model and the ocean exchange simulated by the OPA-PISCES-T model are considered as the prior fluxes. The impacts of CONTRAIL CO2 data on inverted China terrestrial carbon fluxes are quantified, the improvement of the inverted fluxes after adding CONTRAIL CO2 data are rationed against climate factors and evaluated by comparing the simulated atmospheric CO2 concentrations with three independent surface CO2 measurements in China. Results show that with the addition of CONTRAIL CO2 data, the inverted carbon sink in China increases while those in South and Southeast Asia decrease. Meanwhile, the posterior uncertainties over these regions are all reduced (2-12%). CONTRAIL CO2 data also have a large effect on the inter-annual variation of carbon sinks in China, leading to a better correlation between the carbon sink and the annual mean climate factors. Evaluations against the CO2 measurements at three sites in China also show that the CONTRAIL CO2 measurements may have improved the inversion results.

  11. Carbon balance of China constrained by CONTRAIL aircraft CO2 measurements

    NASA Astrophysics Data System (ADS)

    Jiang, F.; Wang, H. M.; Chen, J. M.; Machida, T.; Zhou, L. X.; Ju, W. M.; Matsueda, H.; Sawa, Y.

    2014-03-01

    Terrestrial CO2 flux estimates in China using atmospheric inversion method are beset with considerable uncertainties because very few atmospheric CO2 concentration measurements are available. In order to improve these estimates, nested atmospheric CO2 inversion during 2002-2008 is performed in this study using passenger aircraft-based CO2 measurements over Eurasia from the Comprehensive Observation Network for Trace gases by Airliner (CONTRAIL) project. The inversion system includes 43 regions with a focus on China, and is based on the Bayesian synthesis approach and the TM5 transport model. The terrestrial ecosystem carbon flux modeled by the BEPS model and the ocean exchange simulated by the OPA-PISCES-T model are considered as the prior fluxes. The impacts of CONTRAIL CO2 data on inverted China terrestrial carbon fluxes are quantified, the improvement of the inverted fluxes after adding CONTRAIL CO2 data are rationed against climate factors and evaluated by comparing the simulated atmospheric CO2 concentrations with three independent surface CO2 measurements in China. Results show that with the addition of CONTRAIL CO2 data, the inverted carbon sink in China increases while those in South and Southeast Asia decrease. Meanwhile, the posterior uncertainties over these regions are all reduced. CONTRAIL CO2 data also have a large effect on the inter-annual variation of carbon sinks in China, leading to a better correlation between the carbon sink and the annual mean climate factors. Evaluations against the CO2 measurements at three sites in China also show that the CONTRAIL CO2 measurements have improved the inversion results.

  12. Evaluate the Restoration Potential of Snake River Fall Chinook Salmon Spawning Habitat, Status Report 2006.

    SciTech Connect

    Hanrahan, T.P.

    2009-01-08

    The Bonneville Power Administration (BPA) Project 2003-038-00, Evaluate the restoration potential of Snake River fall Chinook salmon spawning habitat, began in FY04 (15 December 2003) and continues into FY06. This status report is intended to summarize accomplishments during FY04 and FY05. Accomplishments are summarized by Work Elements, as detailed in the Statement of Work (see BPA's project management database PISCES). This project evaluates the restoration potential of mainstem habitats for fall Chinook salmon. The studies address two research questions: 'Are there sections not currently used by spawning fall Chinook salmon within the impounded lower Snake River that possess the physical characteristics for potentially suitable fall Chinook spawning habitat?' and 'Can hydrosystem operations affecting these sections be adjusted such that the sections closely resemble the physical characteristics of current fall Chinook salmon spawning areas in similar physical settings?' Efforts are focused at two study sites: (1) the Ice Harbor Dam tailrace downstream to the Columbia River confluence, and (2) the Lower Granite Dam tailrace. Our previous studies indicated that these two areas have the highest potential for restoring Snake River fall Chinook salmon spawning habitat. The study sites will be evaluated under existing structural configurations at the dams (i.e., without partial removal of a dam structure), and alternative operational scenarios (e.g., varying forebay/tailwater elevations). The areas studied represent tailwater habitat (i.e., riverine segments extending from a dam downstream to the backwater influence from the next dam downstream). We are using a reference site, indicative of current fall Chinook salmon spawning areas in tailwater habitat, against which to compare the physical characteristics of each study site. The reference site for tailwater habitats is the section extending downstream from the Wanapum Dam tailrace on the Columbia River. Escapement

  13. IBIRYS: a Regional High Resolution Reanalysis (physical and biogeochemical) over the European North East Shelf

    NASA Astrophysics Data System (ADS)

    Levier, Bruno; Benkiran, Mounir; Reffray, Guillaume; García Sottilo, Marcos

    2014-05-01

    Mercator-Ocean has developed a regional forecasting system at 1/12° resolution over the North East Atlantic (IBI: Iberia, Biscay and Irish), taking advantage of the recent developments in NEMO. A reanalysis, called IBIRYS, was performed with the IBI system on the 2002-2012 period. The physical model was coupled on-line with the biogeochemical component of NEMO based on the PISCES model. The model was forced by ERA-interim products (every 3 hours) including the atmospheric pressure. In addition to atmospheric forcing, the model included astronomical tidal forcing. This regional forecasting system used boundary conditions from the Mercator-Ocean global reanalysis (GLORYS: GLobal Ocean ReanalYses and Simulations).The assimilation component SAM2 (Mercator Ocean assimilation system), was based on a reduced-order Kalman filter (the SEEK or Singular Extended Evolutive Kalman filter). An IAU method (Incremental Analysis Updates) was used to apply the increments in the system. The error statistics were represented in a sub-space spanned by a small number of dominant 3D error directions. A 3D-Var scheme corrected for the slowly evolving large-scale biases in temperature and salinity. The data assimilation system allowed to constrain the model in a multivariate way with Sea Surface Temperature (AVHRR + Multi-satellite High resolution), together with all available satellite Sea Level Anomalies, and with in situ observations from the CORA-03 data base, including ARGO floats temperature and salinity measurements. In this presentation, the results obtained with IBIRYS are compared to GLORYS results. The consistency of the IBIRYS and GLORYS results at large scales is demonstrated. The capacity of IBIRYS to provide useful information at high frequencies in the North East Atlantic is shown. The biogeochemical results of IBIRYS are evaluated.

  14. Plume-Vent Fluid Connections along the Tonga-Kermadec arc

    NASA Astrophysics Data System (ADS)

    Massoth, G. J.; Arculus, R. J.; Baker, E. T.; Butterfield, D. A.; Chadwick, W. W.; Christenson, B. W.; de Ronde, C. E.; Embley, R. W.; Evans, L. J.; Faure, K.; Graham, I. J.; Greene, R. R.; Ishibashi, J.; Lebon, G. T.; Lupton, J. E.; Resing, J. A.; Roe, K. K.; Schmidt, M.; Stoffers, P.; Walker, S. L.; Worthington, T. J.; Wright, I. C.; Yamanaka, T.

    2005-12-01

    The full extent of the 2530 km-long Tonga-Kermadec intra-oceanic arc was systematically surveyed for hydrothermal plume emissions during 5 expeditions between 1999 and 2005: NZAPLUME I, II and III covered the Kermadec arc using the New Zealand RV TANGAROA and the TELVE and NoToVE cruises surveyed the Tonga arc aboard the Australian RV SOUTHERN SURVEYOR after preliminary swath mapping by the German RV SONNE. At least 71 volcanic centers comprise the arc front, with about 75% of these first mapped or newly discovered during the expeditions. Hydrothermal plumes were detected as light scattering and chemical anomalies over more than half (36) of the volcanoes surveyed. Forty submersible dives were made on one-third (12) of the hydrothermally active volcanoes during the past year: 4 inaugural dives by the Japanese submersible SHINKAI 6500 on Brothers volcano, and 36 dives using the NOAA/HURL submersibles PISCES IV and V on Brothers and an additional 11 volcanoes spread along the arc front. At least 25 venting sites were observed, and most were sampled for gaseous and liquid hydrothermal fluid emanations. We will summarize the pre-dive plume detection results with emphasis on the variability in the magnitude and character of the chemical signals over the active sites and compare/test predictions of the nature of seafloor sources at dive sites with what was actually observed. While most chemical determinations for the seafloor samples are pending, analyses conducted shipboard confirm that simple extension of plume results to the seafloor can be misleading and in contrast to the MOR experience.

  15. Filling in the 2MASX Redshift Zone of Avoidance

    NASA Astrophysics Data System (ADS)

    Kraan-Korteweg, Renee; Staveley-Smith, Lister; Jarrett, Thomas; Schroeder, Anja; Henning, Trish; van Driel, Wim; Said, Khaled

    2014-04-01

    Despite nearly 20 years of concerted effort, the dynamics of the local Universe remain poorly understood. This in part is due to the lack of data in the Zone of Avoidance (ZOA). The current most homogeneous "all-sky'' redshift survey is the 2MASX Redshift Survey (2MRS). However, 2MASX galaxies in the ZOA were excluded from the Redshift follow-up Survey. To fill in the 2MASX redshift gap and map the hidden large-scale structures we started a systematic HI redshift follow-up programme of the brightest 2MASX galaxies, i.e. complement the 2MRS and the 2MASX Tully-Fisher survey (2MTF). A thousand galaxies without previous redshift measurement and Dec > -38 deg have been observed with the Nancay Radio Telescope (NRT). For the remaining southern ZOA we started using the Parkes Radio Telescope. 121 hours of observing time were allocated in the previous semesters (2012OCTS and 2013OCTS/P831). The TAC rating for our previous semester 2013OCT/P831 was 4.1 and they suggest to resubmit for the remainder of the remaining time in 2014APR, with the expectation those observations will be scheduled at the beginning of April. To complete the survey, a further 94 hours with the Parkes MultiBeam System are needed. With the here proposed observations, the ZoA will have systematic coverage from the northern to southern end, providing a unique TF data set to map the important flow fields that cross the ZOA, including the Great Attractor (GA), Perseus-Pisces(PP), Puppis, and the Local Void (LV).

  16. Iron Oxidizing and Reducing Bacteria as Contributors to Basaltic Glass Colonization and Subsequent Weathering in Active Hydrothermal Vent Systems on Loihi and Vailulu'u Seamounts

    NASA Astrophysics Data System (ADS)

    Bailey, B.; Templeton, A.; Haucke, L.; Staudigel, H.; Tebo, B. M.

    2005-12-01

    The extreme oligotrophic nature of the oceanic crust was once believed to be an inhospitable environment to support microbial life. However, numerous studies in the past two decades have revealed diverse chemolithotrophic microbial communities inhabiting the deep biosphere within the oceanic crust. Vailulu'u Seamount in American Samoa and Loihi Seamount in Hawai'i provide access to the deep biosphere environments through the study of the interaction of hydrothermal vent water, basaltic substrates and microbial communities. Both seamounts have been found to exhibit similar iron-encrusted microbial mats surrounding both high and low temperature hydrothermal vent orifices. We are targeting iron as the main electron donor/acceptor in these environments due to the relative abundance and availability in basalts. Through the use of the HURL Pisces submersibles, we exposed amended basaltic glasses of several different compositions to a host of different environments on both seamounts in order to study the colonization and biofilm characteristics of the microbial communities. A large culturing effort reveals multiple iron oxidizing and reducing bacteria as members of the microbial community responsible for the colonization and subsequent dissolution and alteration of basaltic glass. We employ an annular reactor to expose the same suite of chemically altered basaltic glasses to a sample of iron microbial mats taken from Vailulu'u to provide a laboratory complement the environmental exposure experiments. Here cell counts reveal a 90% enhanced colonization and growth on the basalt glass versus the surrounding epoxy and borosilicate glass. The ability of microbes to leach nutrients (such as iron) out of the host substrate has far reaching astrobiological implications for nutrient sources available to sustain life in a Mars or Europa biosphere.

  17. The response of abyssal organisms to low pH conditions during a series of CO2-release experiments simulating deep-sea carbon sequestration

    NASA Astrophysics Data System (ADS)

    Barry, J. P.; Buck, K. R.; Lovera, C.; Brewer, P. G.; Seibel, B. A.; Drazen, J. C.; Tamburri, M. N.; Whaling, P. J.; Kuhnz, L.; Pane, E. F.

    2013-08-01

    The effects of low-pH, high-pCO2 conditions on deep-sea organisms were examined during four deep-sea CO2 release experiments simulating deep-ocean C sequestration by the direct injection of CO2 into the deep sea. We examined the survival of common deep-sea, benthic organisms (microbes; macrofauna, dominated by Polychaeta, Nematoda, Crustacea, Mollusca; megafauna, Echinodermata, Mollusca, Pisces) exposed to low-pH waters emanating as a dissolution plume from pools of liquid carbon dioxide released on the seabed during four abyssal CO2-release experiments. Microbial abundance in deep-sea sediments was unchanged in one experiment, but increased under environmental hypercapnia during another, where the microbial assemblage may have benefited indirectly from the negative impact of low-pH conditions on other taxa. Lower abyssal metazoans exhibited low survival rates near CO2 pools. No urchins or holothurians survived during 30-42 days of exposure to episodic, but severe environmental hypercapnia during one experiment (E1; pH reduced by as much as ca. 1.4 units). These large pH reductions also caused 75% mortality for the deep-sea amphipod, Haploops lodo, near CO2 pools. Survival under smaller pH reductions (ΔpH<0.4 units) in other experiments (E2, E3, E5) was higher for all taxa, including echinoderms. Gastropods, cephalopods, and fish were more tolerant than most other taxa. The gastropod Retimohnia sp. and octopus Benthoctopus sp. survived exposure to pH reductions that episodically reached -0.3 pH units. Ninety percent of abyssal zoarcids (Pachycara bulbiceps) survived exposure to pH changes reaching ca. -0.3 pH units during 30-42 day-long experiments.

  18. The electrostatic profile of consecutive Cβ atoms applied to protein structure quality assessment

    PubMed Central

    Chakraborty, Sandeep; Venkatramani, Ravindra; Rao, Basuthkar J.; Asgeirsson, Bjarni; Dandekar, Abhaya M.

    2014-01-01

    The structure of a protein provides insight into its physiological interactions with other components of the cellular soup. Methods that predict putative structures from sequences typically yield multiple, closely-ranked possibilities. A critical component in the process is the model quality assessing program (MQAP), which selects the best candidate from this pool of structures. Here, we present a novel MQAP based on the physical properties of sidechain atoms. We propose a method for assessing the quality of protein structures based on the electrostatic potential difference (EPD) of Cβ atoms in consecutive residues. We demonstrate that the EPDs of Cβ atoms on consecutive residues provide unique signatures of the amino acid types. The EPD of Cβ atoms are learnt from a set of 1000 non-homologous protein structures with a resolution cuto of 1.6 Å obtained from the PISCES database. Based on the Boltzmann hypothesis that lower energy conformations are proportionately sampled more, and on Annsen's thermodynamic hypothesis that the native structure of a protein is the minimum free energy state, we hypothesize that the deviation of observed EPD values from the mean values obtained in the learning phase is minimized in the native structure. We achieved an average specificity of 0.91, 0.94 and 0.93 on hg_structal, 4state_reduced and ig_structal decoy sets, respectively, taken from the Decoys `R' Us database. The source code and manual is made available at https://github.com/sanchak/mqap and permanently available on 10.5281/zenodo.7134. PMID:25506420

  19. AO Capabilities at the MMT for the User

    NASA Astrophysics Data System (ADS)

    Lloyd-Hart, Michael M.

    2009-05-01

    The MMT operates a facility natural guide star (NGS) AO system. Diffraction limited imaging and medium and high resolution spectroscopy in the near IR are offered over the full isoplanatic field with the ARIES instrument.The system also offers imaging with unique sensitivity in the thermal IR from 3 to 10 microns thanks to its use of an adaptive secondary mirror. L and M band imaging is offered with Clio which has a 12x15 arcsec field of view with Nyquist sampling if the diffraction limt. Recent M band images from Clio show the planetary system around HR8799. In addition, 10 - 25 micron imaging is offered with the MIRAC camera, which may also be operated as a Bracewell nulling interferometer. In this mode, two large subapertures are defined within the pupil. Light from the two is combined so as to cancel the light from an unresolved star through destructive interference, while the environs are imaged in constructive interference. In this way, dust disks and planetary systems may be imaged with greatly improved contrast. The MMT also operates the first astronomical adaptive optics system to employ multiple laser guide stars (LGS). Its initial operational mode, ground-layer adaptive optics (GLAO), provides uniform stellar wavefront correction within the 2 arcmin diameter laser beacon constellation, routinely reducing the stellar image widths to < 0.3 arcsec in the J - K bands. An imaging camera,PISCES, is available for these bands with 2 arcmin field of view sampled at 0.1 arcsec/pixel. In addition, L and M band imaging will be available with Clio in the fall of 2009, opening up near all-sky coverage with near-diffraction limited image quality and emissivity of just 7%.

  20. NATURAL CO2 FLOW FROM THE LOIHI VENT: IMPACT ON MICROBIAL PRODUCTION AND FATE OF THE CO2

    SciTech Connect

    Richard B. Coffin; Thomas J. Boyd; David L. Knies; Kenneth S. Grabowski; John W. Pohlman; Clark S. Mitchell

    2004-02-27

    The program for International Collaboration on CO{sub 2} Ocean Sequestration was initiated December 1997. Preliminary steps involved surveying a suite of biogeochemical parameters off the coast of Kona on the Big Island of Hawaii. The preliminary survey was conducted twice, in 1999 and 2000, to obtain a thorough data set including measurements of pH, current profiles, CO{sub 2} concentrations, microbial activities, and water and sediment chemistries. These data were collected in order to interpret a planned CO{sub 2} injection experiment. After these preliminary surveys were completed, local environment regulation forced moving the project to the coast north east of Bergen, Norway. The preliminary survey along the Norwegian Coast was conducted during 2002. However, Norwegian government revoked a permit, approved by the Norwegian State Pollution Control Authority, for policy reasons regarding the CO{sub 2} injection experiment. As a result the research team decided to monitor the natural CO{sub 2} flow off the southern coast of the Big Island. From December 3rd-13th 2002 scientists from four countries representing the Technical Committee of the International Carbon Dioxide Sequestration Experiment examined the hydrothermal venting at Loihi Seamount (Hawaiian Islands, USA). Work focused on tracing the venting gases, the impacts of the vent fluids on marine organisms, and CO{sub 2} influence on biogeochemical cycles. The cruise on the R/V Ka'imikai-O-Kanaloa (KOK) included 8 dives by the PISCES V submarine, 6 at Loihi and 2 at a nearby site in the lee of the Big Island. Data for this final report is from the last 2 dives on Loihi.

  1. Carbon dioxide and helium in hydrothermal fluids from Loihi Seamount, Hawaii, USA: Temporal variability and implications for the release of mantle volatiles

    SciTech Connect

    Sedwick, P.N.; McMurtry, G.M. ); Hilton, D.R. ); Goff, F. )

    1994-02-01

    Dissolved CO[sub 2], [delta][sup 13]C, He, and [sup 3]He/[sup 4]He were determined in warm (<30[degrees]C) hydrothermal fluids from Pele's Vents on the summit of Lihi Seamount, Hawaii, collected during DSRV Pisces V dives in August and September 1992. Total dissolved CO[sub 2] and He are highly enriched over ambient seawater, with maximum measured concentrations of 190 mmol/kg C[sub T] and 0.193 [mu]mol/kg He, and correlate linearly with dissolved Si concentration and sample temperature. Carbon dioxide [delta][sup 13]C values range from [minus]5.5 to 1.7% (PDB) and corrected [sup 3]He/[sup 4]He ratios from 21.7 to 27.0 R[sub a], indicating a primary magmatic source for both gases. The high concentrations of these volatiles in the vent waters relative to reported bulk concentrations in Lihi basalts suggest that both gases are most likely introduced into the fluids by direct degassing from a magma body, rather than hydrothermal extraction from the summit laves. Comparison of the [sup 3]He/[sup 4]He ratios of the vent waters with reported values for Loihi basalts suggests that the mantle-derived volatiles in the fluids are variably contaminated by radiogenic He, probably due to assimilation of basement rock by the source magma. Such a mechanism could also be responsible for the range of [sup 3]He/[sup 4]He ratios observed in lavas from Loihi. The data demonstrate remarkable temporal variation in the volatile content of the vent fluids. The authors suggest that these temporal changes reflect progressive degassing from a magmatic intrusion with significant fractionation of CO[sub 2] and He, a process which may also account for the range in C/He ratios of Lihi lavas.

  2. Revisiting caryophyllidean type of spermiogenesis in the Eucestoda based on spermatozoon differentiation and ultrastructure of Caryophyllaeus laticeps (Pallas, 1781).

    PubMed

    Bruňanská, Magdaléna; Kostič, Borislav

    2012-01-01

    Spermiogenesis of the monozoic cestode Caryophyllaeus laticeps (Pallas, 1781) (Caryophyllidea: Caryophyllaeidae), a parasite of Abramis brama (Pisces: Cyprinidae), has been investigated by means of transmission electron microscopy and cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for glycogen. The process of spermatozoon formation corresponds in the basic pattern to that of Khawia armeniaca as described by Bruňanská and Poddubnaya (Parasitol Res 99:449-454, 2006). The dense material at the early stages of spermiogenesis, an intercentriolar body, the formation of a free flagellum and flagellar bud, the penetration of the nucleus into the spermatid body when the fusion of the free flagellum with the median cytoplasmic process has started, and a complete proximodistal fusion have been determined. In contrast to previous data on the caryophyllidean type spermiogenesis, the latter more recent observations show the presence and the rotation of a free flagellum and a flagellar bud. This pattern indicates clearly a derived stage of spermiogenesis in the Caryophyllidea, when the second shorter flagellum is greatly reduced comparing with that in the Spathebothriidea, Diphyllobothriidea, or Bothriocephalidea, thus forming a flagellar bud. The flagellar bud occurs in all stages of spermiogenesis and represents an evolved character in the Caryophyllidea. The mature spermatozoon of C. laticeps consists of one axoneme of the 9 + "1" trepaxonematan structure, parallel cortical microtubules, and a nucleus. Cell components are situated in a moderately electrondense cytoplasm, containing glycogen in the principal regions (II, III, and IV) of the spermatozoon. A crested body is absent. Similarities and differences between spermatozoa of caryophyllideans as well as other Eucestoda are discussed. PMID:21607690

  3. Maximising the size of non-redundant protein datasets using graph theory.

    PubMed

    Bull, Simon C; Muldoon, Mark R; Doig, Andrew J

    2013-01-01

    Analysis of protein data sets often requires prior removal of redundancy, so that data is not biased by containing similar proteins. This is usually achieved by pairwise comparison of sequences, followed by purging so that no two pairs have similarities above a chosen threshold. From a starting set, such as the PDB or a genome, one should remove as few sequences as possible, to give the largest possible non-redundant set for subsequent analysis. Protein redundancy can be represented as a graph, with proteins as nodes connected by undirected edges, if they have a pairwise similarity above the chosen threshold. The problem is then equivalent to finding the maximum independent set (MIS), where as few nodes are removed as possible to remove all edges. We tested seven MIS algorithms, three of which are new. We applied the methods to the PDB, subsets of the PDB, various genomes and the BHOLSIB benchmark datasets. For PDB subsets of up to 1000 proteins, we could compare to the exact MIS, found by the Cliquer algorithm. The best algorithm was the new method, Leaf. This works by adding clique members that have no edges to nodes outside the clique to the MIS, starting with the smallest cliques. For PDB subsets of up to 1000 members, it usually finds the MIS and is fast enough to apply to data sets of tens of thousands of proteins. Leaf gives sets that are around 10% larger than the commonly used PISCES algorithm, that are of identical quality. We therefore suggest that Leaf should be the method of choice for generating non-redundant protein data sets, though it is ineffective on dense graphs, such as the BHOLSIB benchmarks. The Leaf algorithm is available at: https://github.com/SimonCB765/Leaf, and sets from genomes and the PDB are available at: http://www.bioinf.manchester.ac.uk/leaf/. PMID:23393584

  4. Molecular and Morphological Evidence Demonstrating Two Species of Helicometrina Linton 1910 (Digenea: Opecoelidae) in Northern Chile.

    PubMed

    Oliva, Marcelo E; Valdivia, Isabel M; Chavez, Rosa A; Molina, Horacio; Cárdenas, Leyla

    2015-12-01

    The opecoelid Helicometrina nimia Linton, 1910 has been reported from numerous marine fishes along the Pacific and Atlantic coasts of the Americas. Along the Chilean coast, H. nimia is found in fishes belonging to at least 9 families. This surprisingly low host specificity of H. nimia raises question about the correct identification of specimens assigned to this species. Here we evaluate whether H. nimia specimens isolated from sympatric fish species in northern Chile but with different diets and found in different habitats (water column and demersal) are the same species. Our results demonstrate that specimens from the shallow benthic fish Labrisomus philippii (Steindachner) do not correspond to H. nimia but instead belong to a new species of Helicometrina. This species is described and distinguished from H. nimia using morphological descriptions and 2 molecular markers (the cytochrome c oxidase subunit 1 gene and the V4 region of the SSU rRNA gene). The new species Helicometrina labrisomi (Digenea: Opecoelidae), is found in the intestine of L. philippii (Steindachner, 1866) (Pisces: Labrisomidae), a shallow benthic fish that inhabits the northern coast of Chile. We also studied the related Helicometrina nimia Linton, 1910 from the benthopelagic fishes Paralabrax humeralis (Valenciennes, 1828) and Acanthistius pictus (Tschudi, 1846) (Serranidae). The new species differs from H. nimia by a combination of characters that include ovary shape, number of uterine loops, and position of the genital pore. Our results indicate that morphological characteristics, such as body size, extent of the vitellarium, shape of the testes, and cirrus sac size and extent, traditionally used in the taxonomy of Helicometrina are highly variable. In contrast, meristic and morphological characteristics, such as a lobed ovary, the number of uterine loops, dimensions of the pharynx, and the opening of the genital pore, are highly constant. PMID:26221995

  5. Temporary Restoration of Bull Trout Passage at Albeni Falls Dam, 2008 Progress Report.

    SciTech Connect

    Bellgraph, Brian J.

    2009-03-31

    The goal of this project is to provide temporary upstream passage of bull trout around Albeni Falls Dam on the Pend Oreille River, Idaho. Our specific objectives are to capture fish downstream of Albeni Falls Dam, tag them with combination acoustic and radio transmitters, release them upstream of Albeni Falls Dam, and determine if genetic information on tagged fish can be used to accurately establish where fish are located during the spawning season. In 2007, radio receiving stations were installed at several locations throughout the Pend Oreille River watershed to detect movements of adult bull trout; however, no bull trout were tagged during that year. In 2008, four bull trout were captured downstream of Albeni Falls Dam, implanted with transmitters, and released upstream of the dam at Priest River, Idaho. The most-likely natal tributaries of bull trout assigned using genetic analyses were Grouse Creek (N = 2); a tributary of the Pack River, Lightning Creek (N = 1); and Rattle Creek (N = 1), a tributary of Lightning Creek. All four bull trout migrated upstream from the release site in Priest River, Idaho, were detected at monitoring stations near Dover, Idaho, and were presumed to reside in Lake Pend Oreille from spring until fall 2008. The transmitter of one bull trout with a genetic assignment to Grouse Creek was found in Grouse Creek in October 2008; however, the fish was not found. The bull trout assigned to Rattle Creek was detected in the Clark Fork River downstream from Cabinet Gorge Dam (approximately 13 km from the mouth of Lightning Creek) in September but was not detected entering Lightning Creek. The remaining two bull trout were not detected in 2008 after detection at the Dover receiving stations. This report details the progress by work element in the 2008 statement of work, including data analyses of fish movements, and expands on the information reported in the quarterly Pisces status reports.

  6. Development and evaluation of CNRM Earth system model - CNRM-ESM1

    NASA Astrophysics Data System (ADS)

    Séférian, Roland; Delire, Christine; Decharme, Bertrand; Voldoire, Aurore; Salas y Melia, David; Chevallier, Matthieu; Saint-Martin, David; Aumont, Olivier; Calvet, Jean-Christophe; Carrer, Dominique; Douville, Hervé; Franchistéguy, Laurent; Joetzjer, Emilie; Sénési, Séphane

    2016-04-01

    We document the first version of the Centre National de Recherches Météorologiques Earth system model (CNRM-ESM1). This model is based on the physical core of the CNRM climate model version 5 (CNRM-CM5) model and employs the Interactions between Soil, Biosphere and Atmosphere (ISBA) and the Pelagic Interaction Scheme for Carbon and Ecosystem Studies (PISCES) as terrestrial and oceanic components of the global carbon cycle. We describe a preindustrial and 20th century climate simulation following the CMIP5 protocol. We detail how the various carbon reservoirs were initialized and analyze the behavior of the carbon cycle and its prominent physical drivers. Over the 1986-2005 period, CNRM-ESM1 reproduces satisfactorily several aspects of the modern carbon cycle. On land, the model captures the carbon cycling through vegetation and soil, resulting in a net terrestrial carbon sink of 2.2 Pg C year-1. In the ocean, the large-scale distribution of hydrodynamical and biogeochemical tracers agrees with a modern climatology from the World Ocean Atlas. The combination of biological and physical processes induces a net CO2 uptake of 1.7 Pg C year-1 that falls within the range of recent estimates. Our analysis shows that the atmospheric climate of CNRM-ESM1 compares well with that of CNRM-CM5. Biases in precipitation and shortwave radiation over the tropics generate errors in gross primary productivity and ecosystem respiration. Compared to CNRM-CM5, the revised ocean-sea ice coupling has modified the sea-ice cover and ocean ventilation, unrealistically strengthening the flow of North Atlantic deep water (26.1 ± 2 Sv). It results in an accumulation of anthropogenic carbon in the deep ocean.

  7. The PAndAS field of streams: Stellar structures in the milky way halo toward Andromeda and Triangulum

    SciTech Connect

    Martin, Nicolas F.; Ibata, Rodrigo A.; Rich, R. Michael; Collins, Michelle L. M.; Fardal, Mark A.; Irwin, Michael J.; Lewis, Geraint F.; Bate, Nicholas F.; Conn, Anthony R.; McConnachie, Alan W.; Babul, Arif; Navarro, Julio F.; Chapman, Scott C.; Crnojević, Denija; Ferguson, Annette M. N.; Peñarrubia, Jorge; Mackey, A. Dougal; Tanvir, Nial T.; Valls-Gabaud, David

    2014-05-20

    We reveal the highly structured nature of the Milky Way (MW) stellar halo within the footprint of the Pan-Andromeda Archaeological Survey (PAndAS) photometric survey from blue main sequence (MS) and MS turn-off stars. We map no fewer than five stellar structures within a heliocentric range of ∼5-30 kpc. Some of these are known (the Monoceros Ring, the Pisces/Triangulum globular cluster stream), but we also uncover three well-defined stellar structures that could be, at least partly, responsible for the so-called Triangulum/Andromeda and Triangulum/Andromeda 2 features. In particular, we trace a new faint stellar stream located at a heliocentric distance of ∼17 kpc. With a surface brightness of Σ {sub V} ∼ 32-32.5 mag arcsec{sup –2}, it follows an orbit that is almost parallel to the Galactic plane north of M31 and has so far eluded surveys of the MW halo as these tend to steer away from regions dominated by the Galactic disk. Investigating our follow-up spectroscopic observations of PAndAS, we serendipitously uncover a radial velocity signature from stars that have colors and magnitudes compatible with the stream. From the velocity of eight likely member stars, we show that this stellar structure is dynamically cold, with an unresolved velocity dispersion that is lower than 7.1 km s{sup –1} at the 90% confidence level. Along with the width of the stream (300-650 pc), its dynamics point to a dwarf-galaxy-accretion origin. The numerous stellar structures we can map in the MW stellar halo between 5 and 30 kpc and their varying morphology is a testament to the complex nature of the stellar halo at these intermediate distances.

  8. Radiocarbon Based Ages and Growth Rates: Hawaiian Deep Sea Corals

    SciTech Connect

    Roark, E B; Guilderson, T P; Dunbar, R B; Ingram, B L

    2006-01-13

    The radial growth rates and ages of three different groups of Hawaiian deep-sea 'corals' were determined using radiocarbon measurements. Specimens of Corallium secundum, Gerardia sp., and Leiopathes glaberrima, were collected from 450 {+-} 40 m at the Makapuu deep-sea coral bed using a submersible (PISCES V). Specimens of Antipathes dichotoma were collected at 50 m off Lahaina, Maui. The primary source of carbon to the calcitic C. secundum skeleton is in situ dissolved inorganic carbon (DIC). Using bomb {sup 14}C time markers we calculate radial growth rates of {approx} 170 {micro}m y{sup -1} and ages of 68-75 years on specimens as tall as 28 cm of C. secundum. Gerardia sp., A. dichotoma, and L. glaberrima have proteinaceous skeletons and labile particulate organic carbon (POC) is their primary source of architectural carbon. Using {sup 14}C we calculate a radial growth rate of 15 {micro}m y{sup -1} and an age of 807 {+-} 30 years for a live collected Gerardia sp., showing that these organisms are extremely long lived. Inner and outer {sup 14}C measurements on four sub-fossil Gerardia spp. samples produce similar growth rate estimates (range 14-45 {micro}m y{sup -1}) and ages (range 450-2742 years) as observed for the live collected sample. Similarly, with a growth rate of < 10 {micro}m y{sup -1} and an age of {approx}2377 years, L. glaberrima at the Makapuu coral bed, is also extremely long lived. In contrast, the shallow-collected A. dichotoma samples yield growth rates ranging from 130 to 1,140 {micro}m y{sup -1}. These results show that Hawaiian deep-sea corals grow more slowly and are older than previously thought.

  9. Formation of a Phyllosilicate-, K-feldspar-, and Sulfate-Bearing Hematite Ridge on Mauna Kea Volcano, Hawaii, Under Hydrothermal, Acid-Sulfate Conditions: Process and Mineralogical Analog for the Hematite Ridge on Mt. Sharp, Gale Crater, Mars.

    NASA Astrophysics Data System (ADS)

    Ming, D. W.; Morris, R. V.; Adams, M. E.; Catalano, J. G.; Graff, T. G.; Arvidson, R. E.; Guinness, E. A.; Hamilton, J. C.; Mertzman, S. A.; Fraeman, A.

    2015-12-01

    The Mars Science Laboratory rover Curiosity is currently moving upslope on Mt. Sharp in Gale Crater toward a hematite-bearing ridge. This hematite exposure was originally detected in CRISM spectra and subsequently mapped as part of a ~200 m wide, 6.5 km long ridge extending roughly parallel to the base of Mt. Sharp. CRISM spectra in the region suggest that hematite, smectite, and hydrated sulfates occur as secondary phases in lower layers of Mt. Sharp, separated by an unconformity from overlying anhydrous strata. A potential process and mineralogical analog is a hematite-bearing and weathering-resistant stratum (ridge) is exposed on the Puu Poliahu cinder cone on Mauna Kea (MK) volcano, Hawaii. The MK ridge is the product of hydrothermal alteration of basaltic precursors under acid-sulfate conditions. We are acquiring chemical and mineralogical (VNIR, Mid-IR, and backscatter Moessbauer spectroscopy, and transmission XRD) data on the MK ridge area that correspond to rover and orbiting spacecraft measurements at Gale Crater and elsewhere. The hematite-bearing stratum does not have detectable sulfate minerals by XRD, and hematite is variably present as up to mm-sized black crystals which, together with associated trioctahedral smectite and K-feldspar (from XRD), imply hydrothermal conditions. Adjacent to the MK hematite-bearing stratum are sulfates (jarosite and alunite) that are evidence for aqueous alteration under acid-sulfate conditions, and more soluble sulfates are absent but such phases would not persist if formed because of annual precipitation. Dioctahedral smectite is associated with red hematite and alunite-rich samples. The black and red hematite zones have the highest and lowest MgO/Al2O3 and K2O/Na2O ratios, respectively. Hematite, smectite, jarosite, and K-feldspar have been detected by Curiosity XRD downslope from the Mt. Sharp hematite ridge. MK field work and samples were obtained with PISCES partnership and OMKM, MKMB, BLNR, and KKMC permissions.

  10. Response Of Ocean Carbon Export To Different Model Algorithms

    NASA Astrophysics Data System (ADS)

    Caglar Yumruktepe, Veli; Salihoglu, Baris; Kideys, Ahmet E.

    2013-04-01

    Effects of climate change on the biological carbon pump (BCP) and vice-versa, and the influence of change in ecosystem structure on the dynamics of BCP are vital topics to understand the role of oceans in the global carbon cycle and sequestration of greenhouse gases. Construction of a complete carbon budget, requires better understanding of air-sea exchanges and the processes controlling the vertical and horizontal transport of carbon in the ocean, particularly the biological carbon pump. Improved parameterization of carbon sequestration within ecosystem models is vital to better understand and predict changes in the global carbon cycle. However, due to the complexity of processes controlling particle aggregation, sinking and decomposition, existing ecosystem models necessarily parameterize carbon sequestration using simple algorithms. For this reason, the primary aim of this study is to provide new parameterizations of the downward flux of organic carbon, suitable for inclusion in numerical models. The study area was chosen to be the North Atlantic Basin (NA) and the surrounding shelf seas. In the scope of this study, first, the skill of existing models in representing particle fluxes were compared theoretically. The unique algorithms used in three state-of-the art ecosystem models ERSEM, PISCES and MEDUSA have been compared and tested against observational data collected at the PAP mooring site. For testing purposes, algorithms were inserted into a common 1D pelagic ecosystem model. Following comparison of existing algorithms, new experimental results obtained from targeted mesocosm experiments and open ocean observations, will be utilized to develop improved formulations. New algorithms will be compared to existing model formulations using a standard validation data set complied within the framework of BASIN. In order to assess algorithm response under differing hydrographic environments, each set of algorithms will be tested within a 1D framework at three sites

  11. Evaluation of an operational ocean configuration at 1/12° on the Indonesian seas: Physical/Biogeochemical coupling

    NASA Astrophysics Data System (ADS)

    Gutknecht, Elodie; Reffray, Guillaume; Gehlen, Marion

    2015-04-01

    In the framework of the INDESO (Infrastructure Development of Space Oceanography) project, an operational ocean forecasting center has been developed to monitor the state of the Indonesian seas in terms of circulation, biogeochemistry and fisheries. The forecasting system combines a suite of numerical models connecting physical and biogeochemical parameters to population dynamics of large marine predators. Developed by Mercator Ocean and CLS, the physical/biogeochemical coupled component (INDO12BIO configuration) covers a large region extending from the western Pacific Ocean to the Eastern Indian Ocean at 1/12° resolution. The OPA/NEMO physical ocean model and the PISCES biogeochemical model are coupled in mode "on-line" without degradation in space and time. The operational global ocean forecasting system (1/4°) operated by Mercator Ocean provides the physical forcing while climatological open boundary conditions are prescribed for the biogeochemistry. This poster describes the performances of the INDO12BIO configuration. They are assessed by the evaluation of a reference hindcast simulation covering the last 8 years (2007-2014). Confrontations to satellite, in-situ and climatological observations are commented. Diagnostics are performed on chlorophyll-a, primary production, nutrients and oxygen. The model catches the main characteristics of the biogeochemical tracers in space and time. The seasonal cycle of chlorophyll-a and primary production is in phase with satellite-based products. The northern and southern parts of the archipelago present a distinct seasonal cycle, with higher chlorophyll biomass and production rates in the southern (northern) part during SE (NW) monsoon. Nutrient and oxygen concentrations are correctly reproduced in terms of horizontal and vertical distributions. The biogeochemical content of water masses entering in the archipelago as well as the water mass transformation across the archipelago conserves realistic vertical distribution

  12. Dietary habits of invasive Ponto-Caspian gobies in the Croatian part of the Danube River basin and their potential impact on benthic fish communities.

    PubMed

    Piria, Marina; Jakšić, Goran; Jakovlić, Ivan; Treer, Tomislav

    2016-01-01

    Invasive Ponto-Caspian (P-C(1)) gobies have recently caused dramatic changes in fish assemblage structures throughout the Danube basin. While their presence in the Croatian part of the basin has been noted and distribution studied, their dietary habits and impacts on native fish communities have, until now, been unknown. In 2011, 17 locations in the Sava River Basin were sampled for fish and 15 for benthic invertebrates. Fish population monitoring data, available for nine seasons (2003-2006 and 2010-2014) and 12 locations, were used to analyse the impacts of P-C gobies on benthic fish abundance. Gut content analysis indicates that the monkey goby Neogobius fluviatilis diet is very diverse, but dominated by Trichoptera, Chironomidae, Bivalvia and Odonata. The diet overlaps considerably with the round goby Neogobius melanostomus diet, although Gastropoda are dominant in the latter's diet. Small fish and Gammarus sp. dominate the bighead goby Ponticola kessleri diet. Comparison of gut content with the prey available in the environment indicates that monkey and round gobies exhibit preference for Trichoptera, Megaloptera and Coleoptera, and bighead goby for Trichoptera, Gammarus sp. and Pisces. P-C gobies in the Sava River are spreading upstream, towards the reaches with lower fish diversity. Analyses indicate potentially positive impacts of P-C gobies' presence on some fish populations: round and bighead goby on Balkan golden loach Sabanejewia balcanica and monkey goby on common carp Cyprinus carpio, crucian carp Carassius carassius, burbot Lota lota and Balkan loach Cobitis elongata. However, there are also indications that bighead and round goby could adversely impact the native chub Squalius cephalus and zingel Zingel zingel populations, respectively. As P-C gobies are still in the expansionary period of invasion and the ecosystem still adapting to new circumstances, continued monitoring of fish population dynamics in the Sava basin is needed to determine the

  13. Installation of a Plasmatron at the Belgian Nuclear Research Centre and its Use for Plasma-Wall Interaction Studies

    NASA Astrophysics Data System (ADS)

    Uytdenhouwen, I.; Schuurmans, J.; Decréton, M.; Massaut, V.; Van Oost, G.

    2008-04-01

    In JET and ITER, the first wall will be covered by beryllium and a full or partial W divertor will be common. In DEMO, only high-Z, low erosion material such as tungsten will be present as a plasma facing material. In present day tokamaks, the very high fluence/low temperature plasma cannot be obtained. Important key issues to be resolved according to plasma wall interaction studies are the tritium retention, dust production, resilience to large steady-state fluences, transient loads, surface erosion, material redeposition and neutron damage. Some linear plasma simulators come close to the very high fluences expected in ITER and DEMO such as PSI -2; PISCES-B; NAGDIS-II and pilot-PSI. In future the larger device MAGNUM-PSI will have even higher fluences and lower temperatures for large scale components. The plasmatron facility VISION I to be installed in Mol, will have the capability to investigate mixed materials (with beryllium/tritium contaminations) and in the long term neutron activated samples. The ETHEL plasmatron VISION I from JRC-Ispra was transferred to SCK•CEN (Mol, Belgium) recently. The equipment is meant to study plasma-wall interaction, in particular the interaction with hydrogen isotopes. The facility is capable to produce relatively cold self-sustained volumetric plasmas with a high plasma flux density at the target of about 1020-1021 ions/m2 .s. The plasmatron has a volume of 18 litres, a target diameter of ˜25 cm and modular ion energies in the range of 20-500 eV.

  14. Toxic and genotoxic effects of the 2,4-dichlorophenoxyacetic acid (2,4-D)-based herbicide on the Neotropical fish Cnesterodon decemmaculatus.

    PubMed

    Ruiz de Arcaute, C; Soloneski, S; Larramendy, M L

    2016-06-01

    Acute toxicity and genotoxicity of the 54.8% 2,4-D-based commercial herbicide DMA® were assayed on Cnesterodon decemmaculatus (Pisces, Poeciliidae). Whereas lethal effect was used as the end point for mortality, frequency of micronuclei (MNs), other nuclear abnormalities and primary DNA damage evaluated by the single cell gel electrophoresis (SCGE) assay were employed as end points for genotoxicity. Mortality studies demonstrated an LC50 96h value of 1008mg/L (range, 929-1070) of 2,4-D. Behavioral changes, e.g., gathering at the bottom of the aquarium, slowness in motion, slow reaction and abnormal swimming were observed. Exposure to 2,4-D within the 252-756mg/L range increased the frequency of MNs in fish exposed for both 48 and 96h. Whereas blebbed nuclei were induced in treatments lasting for 48 and 96h, notched nuclei were only induced in fish exposed for 96h. Regardless of both concentration and exposure time, 2,4-D did not induce lobed nuclei and binucleated erythrocytes. In addition, we found that exposure to 2,4-D within the 252-756mg/L range increased the genetic damage index in treatments lasting for either 48 and 96h. The results represent the first experimental evidence of the lethal and several sublethal effects, including behavioral alterations and two genotoxic properties namely the induction of MNs and primary DNA strand breaks, exerted by 2,4-D on an endemic organism as C. decemmaculatus. PMID:26950899

  15. Mining pollution and the diet of the purple-striped Gudgeon Mogurnda Mogurnda Richardson (Eleotridae) in the Finniss River, Northern Territory, Australia

    SciTech Connect

    Jeffree, R.A.; Williams, N.J.

    1980-01-01

    During the dry season of 1974, collections of the purple-striped Gudgeon Mogurnda Mogurnda were taken from the Finniss River of the Northern Territory; during the wet season, this river receives acidic and metallic pollutants from the formerly mined area of Rum Jungle. The fish consumed a great variety of foods, with high abundances of dytiscidae, chironomidae, ceratopogonidae, trichoptera, odonata, copepoda, decapoda, and pisces. For no food was there a significant regression against habitat descriptors in both of the zones; this emphasizes that pollution effects are more complex than simply depressing or raising the abundances of the dietary species. Five foods were more abundant in the diets of the polluted zone, and three in those of the unpolluted zone. The dietary abundances of two foods, both crustacean, increased in the polluted zone, compared to the unpolluted zone, through the dry season. Two categories of foods: (1) those obtaining oxygen directly from the atmosphere or via a film or bubble of air; and (2) the converse set (aquatic respirers), were contrasted for their usefulness in distinguishing between the zones, by both hierarchical agglomerative and discriminant function analyses. One collection from the polluted zone was reclassified as unpolluted on the basis of its grouping behaviour. The relevance for pollution studies of dietary analysis of euryphagous fish, rather than sampling aquatic fauna directly, is discussed in terms of food substitution, switching, strategies for abundance and recovery by the fauna, and possible effects of the pollutants on the fish as an intervening collector. Downstream patterns of abundance of the invertebrate fauna in this study are broadly similar to those of other studies in which such chemically diverse metals as Pb, Zn, and Cu are the pollutants, but there are differences for some faunal components.

  16. Some taxonomic and nomenclatural changes in American Mantodea (Insecta, Dictyoptera)--Part I.

    PubMed

    Agudelo, Antonio A; Rivera, Julio

    2015-01-01

    Multiple nomenclatural problems persist in mantodean taxonomy. This constitutes an important challenge for praying mantis systematics, its forthcoming development and future consolidation. In this first contribution, we attempt solving a number of issues involving mostly Neotropical praying mantis species described by Brazilian entomologists Paulo S. Terra, Cândido F. de Mello-Leitão, Salvador de Toledo Piza Junior and Lauro J. Jantsch. We provide evidence to justify the following nomenclatural changes. In Acanthopidae, Acontiothespis travassosi Jantsch, 1986 is a new synonym of Raptrix perspicua (F. 1787). Changes in Thespidae are: Emboicy Terra, 1982 is a new synonym of Chloromiopteryx Giglio-Tos, 1915, E. mirim Terra, 1982 is transferred to Chloromiopteryx as C. mirim (Terra, 1982) (new combination); Musoniola plurilobata Mello-Leitão, 1937 is transferred to Chloromiopteryx as C. plurilobata (Mello-Leitão, 1937) (new combination); Metathespis modesta Piza, 1968 is removed from synonymy with Chloromiopteryx thalassina (Burmeister, 1838) and considered valid as C. modesta (Piza, 1968) (new combination and status revalidated); Metathespis precaria Piza, 1968 is removed from synonymy with Chloromiopteryx thalassina (Burmeister, 1838) and considered a new synonym of Miobantia rustica (Fabricius, 1781); Eumiopteryx magna Jantsch, 1991 is transferred to Anamiopteryx as A. magna (Jantsch, 1991) (new combination). For Mantidae/Amelinae, Tithrone corseuli Jantsch, 1986 and T. clauseni Jantsch, 1995 are new synonyms of Litaneutria minor (Scudder, 1872); in Mantidae/Photininae Coptopteryx gigliotosi Piza, 1960 (non Werner, 1925), its replacement name Coptopteryx ermannoi Jantsch & Corseuil, 1988 and Paraphotina precaria Piza, 1966 (the latter currently placed within Coptopteryx) are all new synonyms of Coptopteryx argentina (Burmeister, 1838), whereas Brachypteromantis bonariensis Piza 1960 (currently placed among Coptopteryx) is a new synonym of Coptopteryx gayi

  17. Occupational seafood allergy: a review

    PubMed Central

    Jeebhay, M; Robins, T; Lehrer, S; Lopata, A

    2001-01-01

    BACKGROUND—Recent years have seen increased levels of production and consumption of seafood, leading to more frequent reporting of allergic reactions in occupational and domestic settings. This review focuses on occupational allergy in the fishing and seafood processing industry.
REVIEW—Workers involved in either manual or automated processing of crabs, prawns, mussels, fish, and fishmeal production are commonly exposed to various constituents of seafood. Aerosolisation of seafood and cooking fluid during processing are potential occupational situations that could result in sensitisation through inhalation. There is great variability of aerosol exposure within and among various jobs with reported allergen concentrations ranging from 0.001 to 5.061(µg/m3). Occupational dermal exposure occurs as a result of unprotected handling of seafood and its byproducts. Occupational allergies have been reported in workers exposed to arthropods (crustaceans), molluscs, pisces (bony fish) and other agents derived from seafood. The prevalence of occupational asthma ranges from 7% to 36%, and for occupational protein contact dermatitis, from 3% to 11%. These health outcomes are mainly due to high molecular weight proteins in seafood causing an IgE mediated response. Cross reactivity between various species within a major seafood grouping also occurs. Limited evidence from dose-response relations indicate that development of symptoms is related to duration or intensity of exposure. The evidence for atopy as a risk factor for occupational sensitisation and asthma is supportive, whereas evidence for cigarette smoking is limited. Disruption of the intact skin barrier seems to be an important added risk factor for occupational protein contact dermatitis.
CONCLUSION—The range of allergic disease associated with occupational exposure to crab is well characterised, whereas for other seafood agents the evidence is somewhat limited. There is a need for further epidemiological

  18. The biology of habitat dominance; can microbes behave as weeds?

    PubMed Central

    Cray, Jonathan A; Bell, Andrew N W; Bhaganna, Prashanth; Mswaka, Allen Y; Timson, David J; Hallsworth, John E

    2013-01-01

    . Some microbes, such as Escherichia coli, Mycobacterium smegmatis and Pseudoxylaria spp., exhibit characteristics of both weed and non-weed species. We propose that the concept of nonweeds represents a ‘dustbin’ group that includes species such as Synodropsis spp., Polypaecilum pisce, Metschnikowia orientalis, Salmonella spp., and Caulobacter crescentus. We show that microbial weeds are conceptually distinct from plant weeds, microbial copiotrophs, r-strategists, and other ecophysiological groups of microorganism. Microbial weed species are unlikely to emerge from stationary-phase or other types of closed communities; it is open habitats that select for weed phenotypes. Specific characteristics that are common to diverse types of open habitat are identified, and implications of weed biology and open-habitat ecology are discussed in the context of further studies needed in the fields of environmental and applied microbiology. PMID:23336673

  19. Macrobiotic Communities of Vailulu'u Seamount, Samoan Archipelago

    NASA Astrophysics Data System (ADS)

    Young, C. M.; Lee, R. W.; Pile, A. J.; Hudson, I. R.; Brooke, S. D.; Ted, P.; Staudigel, H.; Hart, S.; Bailey, B. E.; Haucke, L.; Koppers, A.; Konter, J.; Templeton, A.; Tebo, B.

    2005-12-01

    Vailulu'u, the active seamount on the hotspot at the Eastern end of the Samoan volcanic chain, was the focus of two research cruises in April and June 2005 using the Pisces V submersible. Warm-water vents on the summit of a newly formed volcanic cone in the crater supported a low-diversity community dominated by thick microbial mats and the synaphobranchid eel Dysommina rugosa. Isotope and gut analyses indicated that the eels feed not on the mats but on planktonic crustaceans imported to the system from the overlying water column. The microbial mat exhibited isotopic signatures consistent with local chemosynthesis, but not methane-based chemosynthesis; A<

  20. Scientific Studies in Support of Shutting In the Macondo Well (Deepwater Horizon) Blowout, Gulf of Mexico (Invited)

    NASA Astrophysics Data System (ADS)

    Hickman, S.; Mooney, W. D.; Hsieh, P. A.; Enomoto, C.; Nelson, P. H.; McNutt, M.

    2010-12-01

    Scientists, engineers and managers from BP, other private companies, universities, government research labs and a broad spectrum of federal agencies have formed a unique cooperative working relationship in responding to the Macondo oil well (Deepwater Horizon) blowout. Among the many activities performed during this effort, U.S. Geological Survey personnel evaluated the potential geologic hazard of shutting in the Macondo well at the sea floor, and collectively decided, with others, the conditions under which it could be safely undertaken. These hazards included the possible loss of wellbore integrity under the anticipated high shut-in pressures, potentially leading to new pathways for hydrocarbon release to the Gulf of Mexico through upward hydraulic fracture propagation and/or soft sediment erosion initiating at possible leak points in the cemented casing. This hazard evaluation required analysis of 2D and 3D seismic surveys, seafloor bathymetry, pressure transient tests, geophysical well logs, in-situ stress (“leak-off”) tests and drilling data (e.g., mud logs) to assess the geological, hydrological and geomechanical conditions at and around the Macondo well. After the well was successfully capped and shut in by BP on July 15, a variety of monitoring practices were put into place to guard against further leaks into the Gulf. These monitoring activities included acquisition of wellhead pressure data, marine multi-channel seismic profiles, sea-floor and sea-surface sonar surveys (the latter using the NOAA RV/Pisces), and wellhead visual/acoustic monitoring. Scientists and engineers from BP, outside consultants, government agencies and the university community then worked together to continuously evaluate these data to ensure that the well remained safely shut in until reservoir pressures were suppressed (“killed”) with heavy drilling mud and the well was sealed with cement. This effort to shut in and then permanently seal the blown-out Macondo well has

  1. New thelodont findings from the Lower Devonian Andrée Land Group, Spitsbergen

    NASA Astrophysics Data System (ADS)

    Blom, H.; Žigaitė, Ž.

    2012-04-01

    . "Mokslas", Vilnius. 334 pp. [in Russian]. Ørvig, T. 1957. Notes on some Palaeozoic lower vertebrates from Spitsbergen and North America. Norsk geol. Tidsskr., 37: 285-353. Talimaa, V. 2000. Significance of thelodonts (Agnatha) in correlation of the Upper Ordovician to Lower Devonian of the northern part of Eurasia. Courier Forschungsinstitut Senckenberg, 223: 69-80. Vieth, J. 1980. Thelodontier-, Acanthodier-, und Elasmobranchier-Schuppen aus dem Unter-Devon der kanadischen Arktis (Agnatha, Pisces). Göttinger Arb. Geol. Paläontol., 23:1-69.

  2. Grays River Watershed Restoration Status Report 2007, May 1, 2007 - October 30, 2008.

    SciTech Connect

    Hanrahan, Tim

    2008-10-20

    The Bonneville Power Administration (BPA) Project 2003-013-00, 'Grays River Watershed Restoration', began in FY04 and continues into FY09. This status report is intended to summarize accomplishments during the period 1 May 2007 through 30 October 2008. Accomplishments are summarized by Work Elements, as detailed in the Statement of Work (see BPA's project management database PISCES). The Pacific Northwest National Laboratory (PNNL) is collaborating with the Columbia River Estuary Task Force (CREST) on implementation of the Grays River Restoration Project. The Grays River is vitally important to the recovery of Lower Columbia River (LCR) chum salmon because it currently has the most viable population remaining in the LCR region. The Grays River watershed is also important to the recovery of salmon and steelhead in the LCR ecosystem. Today, numbers of naturally spawning salmon and steelhead have declined to levels far below historical numbers because of habitat limiting factors that include but are not limited to the lack of habitat connectivity, diversity, channel stability, riparian function and altered stream flow conditions. The objective of this project is to restore habitat-forming processes to enhance salmon and steelhead populations in the Grays River, following recommendations developed during the FY04-06 BPA-sponsored Grays River Watershed Assessment (BPA Project No. 2003-013-00). Specifically, this project will be the first step in restoring channel structure and function that will increase instream habitat diversity, channel stability, and riparian integrity in the critical response reach upstream and adjacent to critical salmon spawning areas of the Grays River. The major component of this strategy is the planning, design, installation, and monitoring of engineered logjams (ELJ) that will rejuvenate historic channel and floodplain processes. Additional restoration measures include reforesting the riparian corridor to enhance future large woody debris

  3. New R/V Falkor Multibeam Data from the Papahānaumokuākea Marine National Monument in the Northwestern Hawaiian Islands

    NASA Astrophysics Data System (ADS)

    Smith, J. R., Jr.; Kelley, C.; Boston, B.; Dechnik, B.; Habel, S.; Harrison, L.; Leonard, J.; Lichowski, F.; Luers, D.; Miller, J. E.; Orange, R.; Patterson, M. A.; Shiro, B.; Taylor, J.; Togia, H.; Tree, J. P.; Tucker, J.; Wagner, D.; Webster, J.; Wright, N.

    2014-12-01

    From March to June 2014, the Schmidt Ocean Institute, along with National Marine Sanctuaries and the National Science Foundation, supported 72 days of mapping surveys on two cruises using R/V Falkor in the Papahānaumokuākea Marine National Monument (PMNM) located within the Northwestern Hawaiian Islands (NWHI). PMNM is one of the largest marine protected areas in the world. Approximately 127,000 km2, 35% of the PMNM, were surveyed using dual multibeam systems from less than 30 to >5000 meters water depth, and thus covering the habitat depth ranges for shallow living corals, mesophotic corals, drowned reefs, to deep-sea corals and sponge communities. A total of 18 seamounts, guyots, banks, or atoll flanks (e.g., Midway and Kure) were mapped in the upper northwestern section of the monument, including the generically named Bank 9 Seamount, which appears to be a composite of a younger Hawaiian seamount and an older Cretaceous guyot. The middle segment of the PMNM consists mostly of large volcanic rift zone ridges and broad carbonate platforms. The rift zones located there are comparable in shape and size with those off Maui and the Island of Hawai'i in the main islands. Likewise, the magnitude of the largest carbonate platform of Gardner Pinnacles suggests its original high island may have met or exceeded the enormity of the Island of Hawai'i. Furthermore, the new mapping data have revealed the detail of numerous landslides and their deposits all along the chain, including an unusual rift zone flank failure creating a knife-edge ridge off Pioneer Bank. Dives with the Pisces V submersible were previously carried out on this feature, where extensive filter feeding biological communities were discovered. Not to be overlooked, the sidescan backscatter component of the multibeam data proved essential for identifying subtle reef features, numerous carbonate terraces, and debris channels that appear to transport sediment down the edifice flanks to the deep seafloor

  4. High resistivity silicon radiation detectors

    NASA Astrophysics Data System (ADS)

    Segal, Julie Diane

    . Using this technique, we built an 8mm diameter drift detector with full volume sensitivity. Two- and three-dimension transient simulations were used to study charge cloud evolution during the drift period. A problem was discovered which is common to PISCES based simulators: when a drift field is present, diffusion spread of the charge cloud is erroneously enhanced in the direction of and proportional to the drift field.

  5. Plasma-surface interaction issues of an all-metal ITER

    NASA Astrophysics Data System (ADS)

    Brooks, J.N.; Allain, J.P.; Doerner, R.P.; Hassanein, A.; Nygren, R.; Rognlien, T.D.; Whyte, D.G.

    2009-03-01

    We assess key plasma-surface interaction issues of an all-metal plasma facing component (PFC) system for ITER, in particular a tungsten divertor, and a beryllium or tungsten first wall. Such a system eliminates problems with carbon divertor erosion and T/C codeposition, and for an all-tungsten system would better extrapolate to post-ITER devices. The issues studied are sputtering, transport and formation of mixed surface layers, tritium codeposition, plasma contamination, edge-localized mode (ELM) response and He-on-W irradiation effects. Code package OMEGA computes PFC sputtering erosion/redeposition in an ITER full power D-T plasma with convective edge transport. The HEIGHTS package analyses plasma transient response. PISCES and other data are used with code results to assess PFC performance. Predicted outer-wall sputter erosion rates are acceptable for Be (0.3 nm s-1) or bare (stainless steel/Fe) wall (0.05 nm s-1) for the low duty factor ITER, and are very low (0.002 nm s-1) for W. T/Be codeposition in redeposited wall material could be significant (~2 gT/400 s-ITER pulse). Core plasma contamination from wall sputtering appears acceptable for Be (~2%) and negligible for W (or Fe). A W divertor has negligible sputter erosion, plasma contamination and T/W codeposition. Be can grow at/near the strike point region of a W divertor, but for the predicted maximum surface temperature of ~800 °C, deleterious Be/W alloy formation as well as major He/W surface degradation will probably be avoided. ELMs are a serious challenge to the divertor, but this is true for all materials. We identify acceptable ELM parameters for W. We conclude that an all-metal PFC system is likely a much better choice for ITER D-T operation than a system using C. We discuss critical R&D needs, testing requirements, and suggest employing a 350-400 °C baking capability for T/Be reduction and using a deposited tungsten first wall test section.

  6. Distributed Bspline Electrothermal Models of SCR Devices for Power Applications and Bulk CMOS Latch-Up Characterizations.

    NASA Astrophysics Data System (ADS)

    Hung, Chih-Ju.

    and thermal models. Because our BSpline electrothermal model is scalable, a large area thyristor is represented by several scaled electrothermal models arranging in a two-dimensional distributed manner. The representation of a large area thyristor with the two-dimensional distributed electrothermal model is described in detail. With the MISIM input deck based on two-dimensional distributed electrothermal model, the inherent electrothermal spreading effect during the turn-on process of a large area thyristor is simulated by MISIM. The excellent agreements between the MISIM and PISCES simulated DC, AC, and electrothermal characteristics are shown.

  7. The biology of habitat dominance; can microbes behave as weeds?

    PubMed

    Cray, Jonathan A; Bell, Andrew N W; Bhaganna, Prashanth; Mswaka, Allen Y; Timson, David J; Hallsworth, John E

    2013-09-01

    , such as Escherichia coli, Mycobacterium smegmatis and Pseudoxylaria spp., exhibit characteristics of both weed and non-weed species. We propose that the concept of nonweeds represents a 'dustbin' group that includes species such as Synodropsis spp., Polypaecilum pisce, Metschnikowia orientalis, Salmonella spp., and Caulobacter crescentus. We show that microbial weeds are conceptually distinct from plant weeds, microbial copiotrophs, r-strategists, and other ecophysiological groups of microorganism. Microbial weed species are unlikely to emerge from stationary-phase or other types of closed communities; it is open habitats that select for weed phenotypes. Specific characteristics that are common to diverse types of open habitat are identified, and implications of weed biology and open-habitat ecology are discussed in the context of further studies needed in the fields of environmental and applied microbiology. PMID:23336673

  8. Behavior of graphite under heat load and in contact with a hydrogen plasma

    NASA Astrophysics Data System (ADS)

    Bohdansky, J.; Croessmann, C. D.; Linke, J.; McDonald, J. M.; Morse, D. H.; Pontau, A. E.; Watson, R. D.; Whitley, J. B.; Goebel, D. M.; Hirooka, Y.; Leung, K.; Conn, R. W.; Roth, J.; Ottenberger, W.; Kotzlowski, H. E.

    1987-05-01

    Graphite is extensively used in large tokamaks today. In these machines the material is exposed to vacuum, to intense heat loads, and to the edge plasma. The use of graphite in such machines, therefore, depends on the outgassing behavior, the heat shock resistance, and thermochemical properties in a hydrogen plasma. Investigations of these properties made at different laboratories are described here. Experiments conducted at Sandia National Laboratories (SNL), Livermore, and the Max-Planck-Institut für Plasmaphysik (IPP) in Garching showed that the outgassing behavior of fine-grain reactor-grade graphite and carbon fiber composites depends on the pretreatment (manufacturing and/or storage). However, after proper outgassing the samples tested behave similarly in the case of fine-grain graphite, but the outgassing remains high for the carbon fiber composites. Heat shock tests have been made with the Electron Beam Test System (EBTS) at SNL, Albuquerque. Directly cooled graphite samples (FE 159 graphite brazed onto Mo tubes) showed no failure at a heat load of 700 W/cm 2, 20 s; or 10 kW, 1 s. Thermal erosion due to sublimination and particle emission from the graphite surface was observed. This effect is related to the surface temperature and becomes significant at temperatures above 2500°K. Fourteen different types of graphite were tested; the main differences among these samples were the different surface temperatures obtained under the same heating conditions. Cracking due to heat shocks was observed in some of the samples, but none of the carbon fiber composites failed. Thermochemical properties have been tested in the PISCES plasma generator at UCLA for ion energies of around 100 eV. The formation of C-H compounds was observed spectroscopically at sample temperatures of around 600°C. However, this chemical reaction did not lead to erosion as observed in beam experiments but to a drastic change of the surface structure due to redeposition. Carbon-hydrogen lines

  9. Evaluation of an operational ocean model configuration at 1/12° spatial resolution for the Indonesian seas (NEMO2.3/INDO12) - Part 2: Biogeochemistry

    NASA Astrophysics Data System (ADS)

    Gutknecht, Elodie; Reffray, Guillaume; Gehlen, Marion; Triyulianti, Iis; Berlianty, Dessy; Gaspar, Philippe

    2016-04-01

    In the framework of the INDESO (Infrastructure Development of Space Oceanography) project, an operational ocean forecasting system was developed to monitor the state of the Indonesian seas in terms of circulation, biogeochemistry and fisheries. This forecasting system combines a suite of numerical models connecting physical and biogeochemical variables to population dynamics of large marine predators (tunas). The physical-biogeochemical coupled component (the INDO12BIO configuration) covers a large region extending from the western Pacific Ocean to the eastern Indian Ocean at 1/12° horizontal resolution. The NEMO-OPA (Nucleus for European Model of the Ocean) physical ocean model and the PISCES (Pelagic Interactions Scheme for Carbon and Ecosystem Studies) biogeochemical model are running simultaneously ("online" coupling), at the same resolution. The operational global ocean forecasting system (1/4°) operated by Mercator Océan provides the physical forcing, while climatological open boundary conditions are prescribed for the biogeochemistry. This paper describes the skill assessment of the INDO12BIO configuration. Model skill is assessed by evaluating a reference hindcast simulation covering the last 8 years (2007-2014). Model results are compared to satellite, climatological and in situ observations. Diagnostics are performed on nutrients, oxygen, chlorophyll a, net primary production and mesozooplankton. The model reproduces large-scale distributions of nutrients, oxygen, chlorophyll a, net primary production and mesozooplankton biomasses. Modelled vertical distributions of nutrients and oxygen are comparable to in situ data sets although gradients are slightly smoothed. The model simulates realistic biogeochemical characteristics of North Pacific tropical waters entering in the archipelago. Hydrodynamic transformation of water masses across the Indonesian archipelago allows for conserving nitrate and oxygen vertical distribution close to observations, in the

  10. Projections of oceanic N2O emissions in the 21st century using the IPSL Earth system model

    NASA Astrophysics Data System (ADS)

    Martinez-Rey, J.; Bopp, L.; Gehlen, M.; Tagliabue, A.; Gruber, N.

    2015-07-01

    The ocean is a substantial source of nitrous oxide (N2O) to the atmosphere, but little is known about how this flux might change in the future. Here, we investigate the potential evolution of marine N2O emissions in the 21st century in response to anthropogenic climate change using the global ocean biogeochemical model NEMO-PISCES. Assuming nitrification as the dominant N2O formation pathway, we implemented two different parameterizations of N2O production which differ primarily under low-oxygen (O2) conditions. When forced with output from a climate model simulation run under the business-as-usual high-CO2 concentration scenario (RCP8.5), our simulations suggest a decrease of 4 to 12 % in N2O emissions from 2005 to 2100, i.e., a reduction from 4.03/3.71 to 3.54/3.56 TgN yr-1 depending on the parameterization. The emissions decrease strongly in the western basins of the Pacific and Atlantic oceans, while they tend to increase above the oxygen minimum zones (OMZs), i.e., in the eastern tropical Pacific and in the northern Indian Ocean. The reduction in N2O emissions is caused on the one hand by weakened nitrification as a consequence of reduced primary and export production, and on the other hand by stronger vertical stratification, which reduces the transport of N2O from the ocean interior to the ocean surface. The higher emissions over the OMZ are linked to an expansion of these zones under global warming, which leads to increased N2O production, associated primarily with denitrification. While there are many uncertainties in the relative contribution and changes in the N2O production pathways, the increasing storage seems unequivocal and determines largely the decrease in N2O emissions in the future. From the perspective of a global climate system, the averaged feedback strength associated with the projected decrease in oceanic N2O emissions amounts to around -0.009 W m-2 K-1, which is comparable to the potential increase from terrestrial N2O sources. However

  11. Oceanic N2O emissions in the 21st century

    NASA Astrophysics Data System (ADS)

    Martinez-Rey, J.; Bopp, L.; Gehlen, M.; Tagliabue, A.; Gruber, N.

    2014-12-01

    The ocean is a substantial source of nitrous oxide (N2O) to the atmosphere, but little is known on how this flux might change in the future. Here, we investigate the potential evolution of marine N2O emissions in the 21st century in response to anthropogenic climate change using the global ocean biogeochemical model NEMO-PISCES. We implemented two different parameterizations of N2O production, which differ primarily at low oxygen (O2) conditions. When forced with output from a climate model simulation run under the business-as-usual high CO2 concentration scenario (RCP8.5), our simulations suggest a decrease of 4 to 12% in N2O emissions from 2005 to 2100, i.e., a reduction from 4.03/3.71 to 3.54/3.56 Tg N yr-1 depending on the parameterization. The emissions decrease strongly in the western basins of the Pacific and Atlantic oceans, while they tend to increase above the Oxygen Minimum Zones (OMZs), i.e., in the Eastern Tropical Pacific and in the northern Indian Ocean. The reduction in N2O emissions is caused on the one hand by weakened nitrification as a consequence of reduced primary and export production, and on the other hand by stronger vertical stratification, which reduces the transport of N2O from the ocean interior to the ocean surface. The higher emissions over the OMZ are linked to an expansion of these zones under global warming, which leads to increased N2O production associated primarily with denitrification. From the perspective of a global climate system, the averaged feedback strength associated with the projected decrease in oceanic N2O emissions amounts to around -0.009 W m-2 K-1, which is comparable to the potential increase from terrestrial N2O sources. However, the assesment for a compensation between the terrestrial and marine feedbacks calls for an improved representation of N2O production terms in fully coupled next generation of Earth System Models.

  12. High-flux plasma exposure of ultra-fine grain tungsten

    DOE PAGESBeta

    Kolasinski, R. D.; Buchenauer, D. A.; Doerner, R. P.; Fang, Z. Z.; Ren, C.; Oya, Y.; Michibayashi, K.; Friddle, R. W.; Mills, B. E.

    2016-05-12

    Here we examine the response of an ultra-fine grained (UFG) tungsten material to high-flux deuterium plasma exposure. UFG tungsten has received considerable interest as a possible plasma-facing material in magnetic confinement fusion devices, in large part because of its improved resistance to neutron damage. However, optimization of the material in this manner may lead to trade-offs in other properties. Moreover, we address two aspects of the problem in this work: (a) how high-flux plasmas modify the structure of the exposed surface, and (b) how hydrogen isotopes become trapped within the material. The specific UFG tungsten considered here contains 100 nm-widthmore » Ti dispersoids (1 wt%) that limit the growth of the W grains to a median size of 960 nm. Metal impurities (Fe, Cr) as well as O were identified within the dispersoids; these species were absent from the W matrix. To simulate relevant particle bombardment conditions, we exposed specimens of the W-Ti material to low energy (100 eV), high-flux (> 1022 m-2 s-1) deuterium plasmas in the PISCES-A facility at the University of California, San Diego. To explore different temperature-dependent trapping mechanisms, we considered a range of exposure temperatures between 200 °C and 500 °C. For comparison, we also exposed reference specimens of conventional powder metallurgy warm-rolled and ITER-grade tungsten at 300 °C. Post-mortem focused ion beam profiling and atomic force microscopy of the UFG tungsten revealed no evidence of near-surface bubbles containing high pressure D2 gas, a common surface degradation mechanism associated with plasma exposure. Thermal desorption spectrometry indicated moderately higher trapping of D in the material compared with the reference specimens, though still within the spread of values for different tungsten grades found in the literature database. Finally, for the criteria considered here, these results do not indicate any significant obstacles to the potential use of UFG

  13. Development of the gigantocerebellum of the weakly electric fish Pollimyrus.

    PubMed

    Haugedé-Carré, F; Szabo, T; Kirschbaum, F

    1979-01-01

    The morphogenesis of the "hypertrophied" mormyrid cerebellum was investigated in Pollimyrus (Pisces). Two adults and 36 larvae and young fish raised in captivity were used. Two Gnathonemus petersii adults were taken for comparison. The ontogenetic development of the various cerebellar structures was analysed in inverse chronological order with the aid of serial sagittal and frontal brain sections. Special attention was given to the trilobed corpus cerebelli (C1, C2, C3), the lobi transitorii et caudales, the valvula, the crista cerebelli, the eminentia granularis and the lobus lineae lateralis. 1. The cerebellar structures are of bilateral origin; they develop from the cerebellar and acoustico-lateral "anlage" of the rhombencephalon behind the rhombomesencephalic fissure, either through budding or individualisation and appear between the 4th and 11th day after spawning. The midline fusion of the symmetrical structures is accomplished somewhat later, between the 8th and 23rd days. 2. The cerebellar structures acquire their definitive spatial organisation within 38 days, except for the valvula whose development takes much longer. Recognisable from the 11th day, the valvula upon which ridges are visible from the beginning continues to grow after the 38th day beyond the mesencephalic ventricle, finally overlying the telencephalon frontally and the different rhombencephalic structures caudally. This development, which includes a large antero-lateral folding of the valvula, takes 240 days. 3. Cytological differentiation is just as complex as the general development of the cerebellar structures. Cortical stratification first begins on the 8th to the 11th day in the corpus cerebelli and in the valvula from day 21 to 23 onwards. This differentiation is characterised throughout almost the entire cerebellum by a downward migration of the superficial undifferentiated cells which then constitute the granular layer. In the valvula, the majority of the undifferentiated cells

  14. The distribution, dominance patterns and ecological niches of plankton functional types in Dynamic Green Ocean Models and satellite estimates

    NASA Astrophysics Data System (ADS)

    Vogt, M.; Hashioka, T.; Payne, M. R.; Buitenhuis, E. T.; Le Quéré, C.; Alvain, S.; Aita, M. N.; Bopp, L.; Doney, S. C.; Hirata, T.; Lima, I.; Sailley, S.; Yamanaka, Y.

    2013-11-01

    We compare the spatial and temporal representation of phytoplankton functional types (pPFTs) in four different Dynamic Green Ocean Models (DGOMs; CCSM-BEC, NEMURO, PISCES and PlankTOM5) to derived phytoplankton distributions from two independent satellite estimates, with a particular focus on diatom distributions. Global annual mean surface biomass estimates for diatoms vary between 0.23 mmol C m-3 and 0.77 mmol C m-3 in the models, and are comparable to a satellite-derived estimate (0.41 mmol C m-3). All models consistently simulate a higher zonal mean diatom biomass contribution in the high latitudes than in the low latitudes, but the relative diatom contribution varies substantially between models with largest differences in the high latitudes (20% to 100% of total biomass). We investigate phytoplankton distribution in terms of annual and monthly mean dominance patterns, i.e. the distribution of locations where a given PFT contributes more than 50% to total biomass. In all models, diatoms tend to dominate large areas of the high latitudes of both hemispheres, and the area of the surface ocean dominated by diatoms is significantly higher in the models than in the satellite estimates. We estimate the realized ecological niches filled by the dominant pPFT at each location as a function of annual mean surface nitrate concentration (NO3), sea surface temperature (SST), and mixed layer depth. A general additive model (GAM) is used to map the probability of dominance of all pPFTs in niche and geographic space. Models tend to simulate diatom dominance over a wider temperature and nutrient range, whereas satellites confine diatom dominance to a narrower niche of low-intermediate annual mean temperatures (annual mean SST < 10 °C), but allow for niches in different ranges of surface NO3 concentrations. For annual mean diatom dominance, the statistically modelled probability of dominance explains the majority of the variance in the data (65.2-66.6%). For the satellite

  15. GRAVITATIONAL LENS CAPTURES IMAGE OF PRIMEVAL GALAXY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Hubble Space Telescope image shows several blue, loop-shaped objects that actually are multiple images of the same galaxy. They have been duplicated by the gravitational lens of the cluster of yellow, elliptical and spiral galaxies - called 0024+1654 - near the photograph's center. The gravitational lens is produced by the cluster's tremendous gravitational field that bends light to magnify, brighten and distort the image of a more distant object. How distorted the image becomes and how many copies are made depends on the alignment between the foreground cluster and the more distant galaxy, which is behind the cluster. In this photograph, light from the distant galaxy bends as it passes through the cluster, dividing the galaxy into five separate images. One image is near the center of the photograph; the others are at 6, 7, 8, and 2 o'clock. The light also has distorted the galaxy's image from a normal spiral shape into a more arc-shaped object. Astronomers are certain the blue-shaped objects are copies of the same galaxy because the shapes are similar. The cluster is 5 billion light-years away in the constellation Pisces, and the blue-shaped galaxy is about 2 times farther away. Though the gravitational light-bending process is not new, Hubble's high resolution image reveals structures within the blue-shaped galaxy that astronomers have never seen before. Some of the structures are as small as 300 light-years across. The bits of white imbedded in the blue galaxy represent young stars; the dark core inside the ring is dust, the material used to make stars. This information, together with the blue color and unusual 'lumpy' appearance, suggests a young, star-making galaxy. The picture was taken October 14, 1994 with the Wide Field Planetary Camera-2. Separate exposures in blue and red wavelengths were taken to construct this color picture. CREDIT: W.N. Colley and E. Turner (Princeton University), J.A. Tyson (Bell Labs, Lucent Technologies) and NASA Image files

  16. Bicuspid evolution of the arterial and venous atrioventricular valves.

    PubMed

    Victor, S; Nayak, V M; Raveen, R; Gladstone, M

    1995-01-01

    Atrioventricular valves were studied in pisces (shark), amphibians (frog), reptiles (turtle, snake and crocodile) and aves (duck, chicken and quail). Dog shark, Tiger shark and Hammerhead shark have a contractile common atrioventricular orifice with anterior and posterior bridging leaflets. Angel shark resembles the frog in having a contractile oval common atrioventricular orifice guarded by two lateral (right and left) and two central bridging (anterior and posterior) leaflets. In turtles and snakes the interatrial septation is complete. The common oval atrioventricular orifice is divided into two D-shaped orifices by the lower edge of the interatrial septum. Each orifice is guarded by a flap valve hanging down from the interatrial septum with rudimentary chordae tendinae, functionally corresponding to the septal leaflet of the human venous atrioventricular valve (VAVV) and the aortic leaflet of the human arterial atrioventricular valve (AAVV). There is no curved mural leaflet on either side related to curved contractile segments of the annuli. In crocodiles, the interventricular septation is complete. The VAVV is bicuspid with a prominent septal and diminutive mural component with no chordopapillary support. The AAVV is bicuspid with direct attachment of the fused commissural lines between the two leaflets to the ventricular musculature. In the aves, with four chambered hearts the VAVV has a curved mussular mural leaflet with a primitive muscular chorda and no septal leaflet. The AAVV resembles closely the human mitral valve. This study lends support to the view that VAVV and AAVV in man are similar in design and function with a D-shaped annulus and a skirt of leaflet tissue divisible into two functional units. The relatively straight part of the annuli suspend the straight leaflets; septal leafleft of the VAVV and aortic leaflet of the AAV. The curved annular components suspend the curved mural leaflets in both valves. Since this segment is contractile, the

  17. Enabling Technologies for Characterizing Exoplanet Systems with Exo-C

    NASA Astrophysics Data System (ADS)

    Cahoy, Kerri Lynn; Belikov, Ruslan; Stapelfeldt, Karl R.; Chakrabarti, Supriya; Trauger, John T.; Serabyn, Eugene; McElwain, Michael W.; Pong, Christopher M.; Brugarolas, Paul

    2015-01-01

    The Exoplanet Science and Technology Definition Team's Internal Coronagraph mission design, called 'Exo-C', utilizes several technologies that have advanced over the past decade with support from the Exoplanet Exploration Program. Following the flow of photons through the telescope, the science measurement is enabled by (i) a precision pointing system to keep the target exoplanet system precisely positioned on the detector during the integration time, (ii) high-performance coronagraphs to block the parent star's light so that the planet's reflected light can be detected, (iii) a wavefront control system to compensate for any wavefront errors such as those due to thermal or mechanical deformations in the optical path, especially errors with high spatial frequencies that could cause contrast-reducing speckles, and (iv) an integral field spectrograph (IFS) that provides moderate resolution spectra of the target exoplanets, permitting their characterization and comparison with models and other data sets. Technologies such as the wavefront control system and coronagraphs will also benefit from other funded efforts in progress, such as the Wide Field Infrared Survey Telescope Astrophysics Focused Telescope Assets (WFIRST-AFTA) program. Similarly, the Exo-C IFS will benefit from the Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES) demonstration. We present specific examples for each of these technologies showing that the state of the art has advanced to levels that will meet the overall scientific, cost, and schedule requirements of the Exo-C mission. These capabilities have matured with testbed and/or ground-telescope demonstrations and have reached a technological readiness level (TRL) that supports their inclusion in the baseline design for potential flight at the end of this decade. While additional work remains to build and test flight-like components (that concurrently meet science as well as size, weight, power, and environmental

  18. In Situ Resource Utilization (ISRU) on the Moon: Moessbauer Spectroscopy as a Process Monitor for Oxygen Production. Results from a Field Test on Mauna Kea Volcano, Hawaii

    NASA Technical Reports Server (NTRS)

    Morris, R.V.; Schroder, C.; Graff, T.G.; Sanders, G.B.; Lee, K.A.; Simon, T.M.; Larson, W.E.; Quinn, J.W.; Clark, L.D.; Caruso, J.J.

    2009-01-01

    Essential consumables like oxygen must to be produced from materials on the lunar surface to enable a sustained, long-term presence of humans on the Moon. The Outpost Precursor for ISRU and Modular Architecture (OPTIMA) field test on Mauna Kea, Hawaii, facilitated by the Pacific International Space Center for Exploration Systems (PISCES) of the University of Hawaii at Hilo, was designed to test the implementation of three hardware concepts to extract oxygen from the lunar regolith: Precursor ISRU Lunar Oxygen Testbed (PILOT) developed by Lockheed Martin in Littleton, CO; Regolith & Environmental Science and Oxygen & Lunar Volatiles Extraction (RESOLVE) developed at the NASA Kennedy Space Center in Cape Canaveral, FL; and ROxygen developed at the NASA Johnson Space Center in Houston, TX. The three concepts differ in design, but all rely on the same general principle: hydrogen reduction of metal cations (primarily Fe2+) bonded to oxygen to metal (e.g., Fe0) with the production of water. The hydrogen source is residual hydrogen in the fuel tanks of lunar landers. Electrolysis of the water produces oxygen and hydrogen (which is recycled). We used the miniaturized M ssbauer spectrometer MIMOS II to quantify the yield of this process on the basis of the quantity of Fe0 produced. Iron M ssbauer spectroscopy identifies iron-bearing phases, determines iron oxidation states, and quantifies the distribution of iron between mineral phases and oxidation states. The oxygen yield can be calculated by quantitative measurements of the distribution of Fe among oxidation states in the regolith before and after hydrogen reduction. A M ssbauer spectrometer can also be used as a prospecting tool to select the optimum feedstock for the oxygen production plants (e.g., high total Fe content and easily reduced phases). As a demonstration, a MIMOS II backscatter spectrometer (SPESI, Germany) was mounted on the Cratos rover (NASA Glenn Research Center in Cleveland, OH), which is one of

  19. Preliminary forecasts of Pacific bigeye tuna population trends under the A2 IPCC scenario

    NASA Astrophysics Data System (ADS)

    Lehodey, P.; Senina, I.; Sibert, J.; Bopp, L.; Calmettes, B.; Hampton, J.; Murtugudde, R.

    2010-07-01

    An improved version of the spatial ecosystem and population dynamics model SEAPODYM was used to investigate the potential impacts of global warming on tuna populations. The model included an enhanced definition of habitat indices, movements, and accessibility of tuna predators to different vertically migrant and non-migrant micronekton functional groups. The simulations covered the Pacific basin (model domain) at a 2° × 2° geographic resolution. The structure of the model allows an evaluation from multiple data sources, and parameterization can be optimized by adjoint techniques and maximum likelihood using fishing data. A first such optimized parameterization was obtained for bigeye tuna ( Thunnus obesus) in the Pacific Ocean using historical catch data for the last 50 years and a hindcast from a coupled physical-biogeochemical model driven by the NCEP atmospheric reanalysis. The parameterization provided very plausible biological parameter values and a good fit to fishing data from the different fisheries, both within and outside the time period used for optimization. We then employed this model to forecast the future of bigeye tuna populations in the Pacific Ocean. The simulation was driven by the physical-biogeochemical fields predicted from a global marine biogeochemistry - climate simulation. This global simulation was performed with the IPSL climate model version 4 (IPSL-CM4) coupled to the oceanic biogeochemical model PISCES and forced by atmospheric CO 2, from historical records over 1860-2000, and under the SRES A2 IPCC scenario for the 21st century (i.e. atmospheric CO 2 concentration reaching 850 ppm in the year 2100). Potential future changes in distribution and abundance under the IPCC scenario are presented but without taking into account any fishing effort. The simulation showed an improvement in bigeye tuna spawning habitat both in subtropical latitudes and in the eastern tropical Pacific (ETP) where the surface temperature becomes optimal for

  20. Discovery of Prehistoric Skies

    NASA Astrophysics Data System (ADS)

    Gurshtein, A. A.

    1995-12-01

    It was Charles Francois Dupui, of France, who two centuries ago in his twelve-volume "Origine de tous les cults" (1795) worked out a proposition that all the different religious customs, stories, and dogmas will be found upon examination to have a cradle as one or another aspect of the natural, mainly, astronomical phenomena. It is absolutely correct but he and his spirited followers failed to develop a basic scientific quantitative argument focused on astronomy - chronological distribution of events. It is the first time that a combination of the up-to-date knowledge in archaic symbology and the professional astronomical data for precession and other regular astronomical events constitutes conditions for an absolutely new approach. An astronomical reconstruction of the evolution of the Zodiacal constellations was made, based on the Indo-european and Sumero-Akkadian religio-cultural data, including artifacts such as cult statuettes, cuneiform tablets, cylinder seals and boundary stones. It was argued that the development of 12 houses of the Zodiac in 3 groups of 4 over some six millennia was dictated by the changes made by precession in the positions of the vernal and autumnal equinoxes and the summer and winter solstices. The first quartet of the Zodiacal constellations (Gemini, Virgo, Sagittarius, Pisces) was recognized by the first agriculturists from the Fertile Crescent to learn the four most important Sun positions and to predict the ongoing seasons; it was done as far back as 5,600 B.C. (with a formal error of this determination about +/- 150 years). The second one (Taurus, Leo, Scorpio, Aquarius) was introduced in 2,700 +/- 250 years B.C. by Egyptians with their own animal symbolism that was the etymological root for the term the Zodiac (a circle of animals). This event was followed with the acquaintance of the new calendar and erection of the great pyramids as an eternal sanctuary for their mental triumph. In the first half of 14 century B.C. the Egyptian

  1. Near Real Time Prospecting for Lunar Volatiles: Demonstrating RESOLVE Science in the Field

    NASA Technical Reports Server (NTRS)

    Elphic, Richard; Colaprete, Anthony; Heldmann, Jennifer; Mattes, Gregory W.; Ennico, Kimberly; Sanders, Gerald; Quinn, Jacqueline; Tegnerud, Erin Leigh; Marinova, Margarita; Larson, William E.; Picard, Martin; Morse, Stephanie

    2012-01-01

    The Regolith and Environment Science and Oxygen & Lunar Volatile Extraction (RESOLVE) project aims to demonstrate the utility of "in situ resource utilization". In situ resource utilization (ISRU) is a way to rebalance the economics of spaceflight by reducing or eliminating materials that must be brought up from Earth and placed on the surface of the Moon for human use. RESOLVE is developing a rover-borne payload that (1) can locate near subsurface volatiles, (2) excavate and analyze samples of the volatile-bearing regolith, and (3) demonstrate the form, extractability and usefulness of the materials. Such investigations are important not only for ISRU but are also critically important for understanding the scientific nature of these intriguing lunar polar volatile deposits. Temperature models and orbital data suggest near surface volatile concentrations may exist at briefly lit lunar polar locations outside persistently shadowed regions. A lunar rover could be remotely operated at some of these locations for the 4-7 days of expected sunlight at relatively low cost. In July 2012 the RESOLVE project conducted a full-scale field demonstration. In particular, the ability to perform the real-time measurement analysis necessary to search for volatiles and the ability to combine the various measurement techniques to meet the mission measurement and science goals. With help from the Pacific International Space Center for Exploration Systems (PISCES), a lunar rover prototype (provided by the Canadian Space Agency) was equipped with prospecting instruments (neutron spectrometer and near-infrared spectrometer), subsurface access and sampling tools, including both an auger and coring drill (provided by CSA) and subsurface sample analysis instrumentation, including a sample oven system, the Oxygen and Volatile Extraction Node (OVEN), and Gas Chromatograph / Mass Spectrometer system, the Lunar Advanced Volatile Analysis (LAVA) system. Given the relatively short time period this

  2. Tully-Fisher Distances and Motions in the Northern Sky

    NASA Astrophysics Data System (ADS)

    Courteau, Stephane

    1992-10-01

    This dissertation consists of a study of large-scale velocity deviations in a uniformly expanding universe. At the onset of this work, galaxy motions in the northern hemisphere, contrary to the impressive sky coverage in the south, were still very poorly mapped. To improve on this situation, we identified a well-defined sample of 380 northern Sb-Sc UGC spirals with a magnitude cutoff of m_B=15.5. Distances are estimated using the Tully-Fisher relation but with rotation velocities measured from long-slit spectra in lieu of 21 cm delta-V's. Surface-brightness profiles and total magnitudes are extracted for 820 r-band images, and (H-alpha +[N II]) rotation curves, fluxes, and rotation profiles are measured from 450 red spectra. The galaxy magnitudes are accurate internally to +-0.022 mag and the delta-V's agree internally to +- 12 km s^-1. A tight linear correlation of optical versus radio velocity widths with a scatter of 24 km s^-1 is also derived. The redshift distribution peaks at 5400 km s^-1, with a tail extending out to 15,000 km s^-1. We find evidence for large-scale motions near the concentration of Perseus-Pisces (PP), but identify a vast region of unperturbed, quiet Hubble flow (QHF) perpendicular to PP. The peculiar velocity (PV) data are corrected for uniform-density Malmquist bias when they are analyzed in estimated distance space; an empirical correction for selection effects mainly due to magnitude cutoff is derived from the QHF region and applied to the PV's in redshift space. Both analyses are consistent in showing the PP supercluster as streaming in bulk towards the Local Group at 392 +- 79 km s^-1 (with respect to the microwave background rest frame). The cause for such motion remains undetermined, but it is most certainly not due to one single object. Gravitational collapse within PP is detected, but the statistical error is large. While we have not calculated a formal bulk motion for the whole volume of space bounded by the Great Attractor and PP

  3. Bridging the PSI Knowledge Gap: A Multi-Scale Approach

    SciTech Connect

    Wirth, Brian D

    2015-01-08

    -coupled extrapolation to a multi-scale, coupled approach. The PSI Plasma Center consisted of three equal co-centers; one located at the MIT Plasma Science and Fusion Center, one at UC San Diego Center for Energy Research and one at the UC Berkeley Department of Nuclear Engineering, which moved to the University of Tennessee, Knoxville (UTK) with Professor Brian Wirth in July 2010. The Center had three co-directors: Prof. Dennis Whyte led the MIT co-center, the UCSD co-center was led by Dr. Russell Doerner, and Prof. Brian Wirth led the UCB/UTK center. The directors have extensive experience in PSI and material research, and have been internationally recognized in the magnetic fusion, materials and plasma research fields. The co-centers feature keystone PSI experimental and modeling facilities dedicated to PSI science: the DIONISOS/CLASS facility at MIT, the PISCES facility at UCSD, and the state-of-the-art numerical modeling capabilities at UCB/UTK. A collaborative partner in the center is Sandia National Laboratory at Livermore (SNL/CA), which has extensive capabilities with low energy ion beams and surface diagnostics, as well as supporting plasma facilities, including the Tritium Plasma Experiment, all of which significantly augment the Center. Interpretive, continuum material models are available through SNL/CA, UCSD and MIT. The participating institutions of MIT, UCSD, UCB/UTK, SNL/CA and LLNL brought a formidable array of experimental tools and personnel abilities into the PSI Plasma Center. Our work has focused on modeling activities associated with plasma surface interactions that are involved in effects of He and H plasma bombardment on tungsten surfaces. This involved performing computational material modeling of the surface evolution during plasma bombardment using molecular dynamics modeling. The principal outcomes of the research efforts within the combined experimental – modeling PSI center are to provide a knowledgebase of the mechanisms of surface degradation, and the

  4. Tracer populations in the Local Group

    NASA Astrophysics Data System (ADS)

    Watkins, Laura L.

    2011-04-01

    So often in astronomy, an object is not considered for its individual merits, but for what we may learn from its properties regarding some larger population. The existence of dark matter is a prime example of this; we cannot see it directly but we can infer its presence by noting its effects on the stars orbiting within its potential. This thesis describes how various sets of tracer populations can be used to probe the properties of a variety of galaxies in the Local Group. I begin by describing the extraction of a variable catalogue from the Sloan Digital Sky Survey Stripe 82 dataset and then use the catalogue to select a high-quality set of RR Lyrae stars. Analysing the distribution of the RR Lyraes reveals three significant substructures in the Milky Way halo: the Hercules-Aquila Cloud and the Sagittarius Stream, which were already known to exist, and the Pisces Overdensity, which was previously undetected. It is a faint, extended structure found at ~80 kpc and is of unknown origin. Altogether, I find that nearly 80% of the RR Lyraes are associated with substructures, consistent with the theory that galaxy halos are predominantly, or even entirely, made up from disrupted satellites. I also investigate the density distribution of RR Lyraes in the halo, finding that it is best fit by a broken-power-law model, in good agreement with previous work. I go on to develop a set of tracer mass estimators that build on previous work which make use of actual (and not projected) distance and proper motion data, reflecting the amount and quality of data now available to us. I show that proper motion data is, in theory, very useful and can greatly increase the accuracy of the mass estimates; in practice, however, current analysis is hampered by the large errors inherent in the proper motion data. The results are also subject to mass-anisotropy degeneracy, which current data is not yet able to break. Nevertheless, I am able to estimate the mass of the Milky Way to be M = 2.7±0

  5. Acidification of the Mediterranean Sea during the 21st century

    NASA Astrophysics Data System (ADS)

    Le Vu, Briac; Palmieri, Julien; Orr, James C.; Dutay, Jean Claude; Sevault, Florence

    2014-05-01

    We modeled the carbon cycle in the Mediterranean Sea to study how its changes due to climate change and rising levels of atmospheric CO2 may differ from those typical of the global ocean. More specifically, we coupled offline an ocean biogeochemical model (PISCES) to a regional eddy-permitting model of the Mediterranean Sea (NEMO-MED8, 1/8° nominal horizonal resolution) using forcing from coupled regional climate model simulations of which the ocean circulation component was identical. Here we describe the simulated changes in pH and the associated carbonate system during the 21st century. Separate simulations were made with climate forcing for a hindcast (1965-2008) and for the future (2000-2100). For the former, climate and CO2 forcings were based on observations; for the latter, both climate and CO2 were driven by the IPCC SRES-A2 scenario. Our hindcast simulation over the period 1965-2008 allowed us to evaluate the model and assess recent variability of the carbonate system. In our future simulation, we used separate tracers to distinguish (1) the change due to climate change and the increase in atmospheric CO2 (from 370 to 800 ppm) and (2) the change due only to climate change (holding atmospheric CO2 to the year-2000 level of 370 ppm). By difference, we isolated the geochemical effect (anthropogenic CO2 perturbation). The hindcast simulation demonstrates that the model captures the amplitude and phase of the annual cycle of temperature, pCO2 and pH, in agreement with data from the DYFAMED station. That seasonal variability of surface pCO2 is everywhere driven by variations in temperature. These results lends support that the model is able to quantify the acidification of the Mediterranean Sea during the industrial period and for the future. However, they do not constrain the model's simulated effects of future climate change on ocean circulation and ocean biology, both of which in turn influence the carbon cycle. Similar to estimates for the global ocean

  6. This Letter is a Non-Technical Annual Report of Activities on Project 2007-275-00, Impact of American Shad for the Period February 1, 2008 through January 31, 2009.

    SciTech Connect

    Parsley, Michael J.

    2009-01-30

    This letter is a non-technical annual report of activities on Project 2007-275-00, Impact of American Shad for the period February 1, 2008 through January 31, 2009. A non-technical report is appropriate at this time since data collection is ongoing and results are preliminary. This report is intended to highlight accomplishments during this performance period. Progress on administrative work elements in the statement of work has been captured in the periodic status reports provided through Pisces. During this performance period the USGS accomplished the following tasks: (1) Co-chaired a symposium on American shad in the Columbia Basin at the annual meeting of the Western Division, American Fisheries Society. The USGS gave four presentations from work done during this project. Abstracts of the presentations were attached to the 2007 progress report. (2) Continued parameterization of a bioenergetics model for juvenile American shad. We performed a literature review to determine the applicability of the existing adult salmon bioenergetics parameters to juvenile fall Chinook salmon in support of our modeling investigation of diet overlap between juvenile American shad and fall Chinook salmon. We formulated testable hypotheses to investigate using bioenergetics models and conceptually developed model simulations. Held an in-house workshop to obtain feedback on the physiological parameters we selected for the American shad bioenergetics model and to solicit feedback on our modeling approach to address research questions. (3) Received a Section 10 ESA sampling permit based on the application submitted in the 2007 contract period. With the ESA permit in hand, we obtained scientific collection permits from the states of Washington and Oregon that allowed us to use a variety of fisheries sampling techniques to capture juvenile and adult American shad. (4) Conducted field sampling to meet project objectives. Gillnetting efforts to capture adult American shad near Astoria were

  7. Rediscovery and Exploration of Magic Mountain, Explorer Ridge, NE Pacific

    NASA Astrophysics Data System (ADS)

    Embley, R. W.

    2002-12-01

    A two-part exploration program at Explorer Ridge, the northernmost spreading segment of the NE Pacific spreading centers, was conducted in two phases during June to August of 2002. A robust hydrothermal system (Magic Mountain) was found in this area in the early 1980s by the Canadian PISCES IV submersible, but its dimensions and geologic relationships were not well determined due to limited dives and poor navigation. The first part of the 2002 exploration program utilized an EM300 multibeam sonar on T. G. Thompson, the autonomous vehicle ABE, and a CTD/rosette system to map the seafloor and conduct hydrothermal plume surveys. While ABE conducted detailed surveys in the area where the most intense hydrothermal plume was found on the initial CTD survey, the T. G. Thompson conducted additional multibeam surveys, CTD casts and CTD tow-yos on the other second order segments up to 60 km away. This increased the efficiency of the expedition by at least 30%. After 12 days on site, a multibeam map was completed of the entire segment, the spatial distribution and character of the hydrothermal plumes were mapped out and a section of seafloor measuring 2 x 5.5 km was mapped in detail with ABE. The ABE used two sonar systems, a previously proven Imagenex pencil beam sonar, and, for the first time, a multibeam sonar (SM2000). In addition to the high-resolution bathymetry (1 m grid-cell size resolution for the SM2000), ABE collected temperature, optical backscatter, eH redox potential, and magnetic field data. Using the CTD and ABE data, a major hydrothermal system was easily located on the seafloor during the second part of the exploration program using the ROPOS remotely operated vehicle. The Magic Mountain hydrothermal system is located almost entirely on the eastern constructional shoulder of the ridge eastward of the rim of the eastern boundary fault of the axial valley. This is in contrast to most other hydrothermal systems on intermediate rate spreading ridges, which are

  8. Exploring Drowned Reefs on Gardner Pinnacles

    NASA Astrophysics Data System (ADS)

    Clague, D. A.; Paduan, J. B.; Braga, J. C.; Humphrey, C.; Hinestrosa, G.; Fullagar, P. D.

    2012-12-01

    Gardner Pinnacles (GP), located in the Northwest Hawaiian Islands within Papahānaumokuākea Marine National Monument, is one of the largest volcanic structures in the entire Hawaiian-Emperor chain. In Oct. 2011, the R/V Ka'imikai-o-Kanaloa mapped and the Pisces IV submersible explored the GP during 7 dives, mainly on drowned reef terraces. New multibeam bathymetric data from the cruise, combined with pre-existing multibeam data mostly collected during transits across the structure, show at least 4 separate volcanoes partially surrounded by several Miocene to Pleistocene drowned coral reefs with extensive lagoons, with the largest volcano surmounted by an active carbonate platform. Large landslides modify the flanks, and the eastern flank is incised by submarine canyons. Seven submersible dives explored and sampled mainly the drowned reef structures. The largest reef complex is on the NW flank above the main break-in-slope, and is a barrier reef surrounding extensive lagoon deposits with complex channel structures. Similar wide lagoons with deep channels parallel to the outer reef terraces are present elsewhere on GP, but unusual elsewhere in the Hawaiian Islands. Seven corals, coralline algae, and echinoid spines from dive P4-266 on that NW edge of GP from 1268-1637 m depth yield a tight age cluster based on Sr-isotopes calibrated to seawater that range from 15.51 to 15.98 Ma, and average 15.76 Ma. Five ages of echinoid spines, mollusk shells, and large foraminfers from dive P4-255 on the SW edge of GP from 1538-1558 m depth range from 14.88 to 15.10 Ma, and average 14.98 Ma. Three ages of corals and coralline algae from dive P4-253 on the SE edge of GP at 1955 m depth range from 12.35 and 12.7 Ma, and average 12.57 Ma. The ages of these reefs indicate when volcanic activity waned and reef deposits could accumulate without constant burial by lava flows; the nearly 3.2 Ma range in reef ages from the flanks of GP suggest that volcanic activity at GP spanned a

  9. Near Real-Time Prospecting for Lunar Volatiles: Demonstrating RESOLVE Science in the Field

    NASA Astrophysics Data System (ADS)

    Elphic, R. C.; Colaprete, A.; Heldmann, J. L.; Mattes, G.; Ennico, K.; Sanders, G. B.; Quinn, J.; Fritzler, E.; Marinova, M.; Roush, T. L.; Stoker, C.; Larson, W.; Picard, M.; McMurray, R.; Morse, S.

    2012-12-01

    The Regolith and Environment Science and Oxygen & Lunar Volatile Extraction (RESOLVE) project aims to demonstrate the utility of "in situ resource utilization". In situ resource utilization (ISRU) is a way to rebalance the economics of spaceflight by reducing or eliminating materials that must be brought up from Earth and placed on the surface of the Moon for human use. RESOLVE is developing a rover-borne payload that (1) can locate near subsurface volatiles, (2) excavate and analyze samples of the volatile-bearing regolith, and (3) demonstrate the form, extractability and usefulness of the materials. Such investigations are important not only for ISRU but are also critically important for understanding the scientific nature of these intriguing lunar polar volatile deposits. Temperature models and orbital data suggest near surface volatile concentrations may exist at briefly lit lunar polar locations outside persistently shadowed regions. A lunar rover could be remotely operated at some of these locations for the 4-7 days of expected sunlight at relatively low cost. In July 2012 the RESOLVE project conducted a full-scale field demonstration. In particular, the ability to perform the real-time measurement analysis necessary to search for volatiles and the ability to combine the various measurement techniques to meet the mission measurement and science goals. With help from the Pacific International Space Center for Exploration Systems (PISCES), a lunar rover prototype (provided by the Canadian Space Agency) was equipped with prospecting instruments (neutron spectrometer and near-infrared spectrometer), subsurface access and sampling tools, including both an auger and coring drill (provided by CSA) and subsurface sample analysis instrumentation, including a sample oven system, the Oxygen and Volatile Extraction Node (OVEN), and Gas Chromatograph / Mass Spectrometer system, the Lunar Advanced Volatile Analysis (LAVA) system. Given the relatively short time period this

  10. Oceanic N2O emissions in the 21st century

    NASA Astrophysics Data System (ADS)

    Martinez-Rey, Jorge; Bopp, Laurent; Gehlen, Marion; Tagliabue, Alessandro

    2013-04-01

    Climate change will cause multiple perturbations in ocean biogeochemistry during the next century. Changes in temperature, carbonate chemistry, salinity and dissolved oxygen concentration will drive changes which remain highly uncertain, especially in the oceanic nitrogen cycle. Of particular interest regarding feedbacks to the Earth System are the oceanic emissions of nitrous oxide. N2O is a powerful greenhouse gas with a residence time of more than 100 years in the atmosphere. Moreover, N2O has been identified as the leading ozone depletion emission since 2010. Oceanic N2O, with an annual contribution of 3.6 Tg N and hence 30% of the total natural sources, is produced by bacterial processes called nitrification and denitrification. These processes are enhanced in regions of high productivity, with denitrification occurring where oxygen concentrations are low, typically below 60 μmol/L. Different parameterizations for N2O production have been proposed over the past decade and considered by current ocean biogeochemical models. However, significant uncertainties remain in particular with respect to the future evolution of N2O production under climate change. We implemented several published parameterizations of N2O production into the biogeochemical model PISCES and estimated the change in N2O production, inventory and N2O sea-to-air flux between 2005 and 2100, under the high emission scenario RCP8.5. This approach is complemented by an offline analysis of 8 model output datasets which contributed to the Coupled Model Intercomparison Project (CMIP5). Projections of N2O flux from the ocean to the atmosphere yield a 5% decrease on average in 2100. North- and southwest basins in the Pacific and Atlantic oceans show the largest reduction in N2O emissions, while the flux tends to increase in regions where the Oxygen Minimum Zones (OMZs) are located, i.e., Eastern Tropical Pacific and Bay of Bengal. The projected expansion of the OMZs, from 6.5 to 8.5 106 km3in our

  11. Predicting the velocity and azimuth of fragments generated by the range destruction or random failure of rocket casings and tankage

    NASA Astrophysics Data System (ADS)

    Eck, M.; Mukunda, M.

    The proliferation of space vehicle launch sites and the projected utilization of these facilities portends an increase in the number of on-pad, ascent, and on-orbit solid-rocket motor (SRM) casings and liquid-rocket tanks which will randomly fail or will fail from range destruct actions. Beyond the obvious safety implications, these failures may have serious resource implications for mission system and facility planners. SRM-casing failures and liquid-rocket tankage failures result in the generation of large, high velocity fragments which may be serious threats to the safety of launch support personnel if proper bunkers and exclusion areas are not provided. In addition, these fragments may be indirect threats to the general public's safety if they encounter hazardous spacecraft payloads which have not been designed to withstand shrapnel of this caliber. They may also become threats to other spacecraft if, by failing on-orbit, they add to the ever increasing space-junk collision cross-section. Most prior attempts to assess the velocity of fragments from failed SRM casings have simply assigned the available chamber impulse to available casing and fuel mass and solved the resulting momentum balance for velocity. This method may predict a fragment velocity which is high or low by a factor of two depending on the ratio of fuel to casing mass extant at the time of failure. Recognizing the limitations of existing methods, the authors devised an analytical approach which properly partitions the available impulse to each major system-mass component. This approach uses the Physics International developed PISCES code to couple the forces generated by an Eulerian modeled gas flow field to a Lagrangian modeled fuel and casing system. The details of a predictive analytical modeling process as well as the development of normalized relations for momentum partition as a function of SRM burn time and initial geometry are discussed in this paper. Methods for applying similar modeling

  12. Not all Laminaria digitata are the same! Phenotypic plasticity and the selection of appropriate surrogate macroalgae for ecohydraulic experimentation

    NASA Astrophysics Data System (ADS)

    Thomas, Robert E.; McLelland, Stuart J.; Henry, Pierre-Yves T.; Paul, Maike; Eiff, Olivier; Evertsen, Antti-Jussi O.; Aberle, Jochen; Teacă, Adrian

    2015-04-01

    Whilst early physical modelling and theoretical studies of the interactions between vegetation and flowing water employed rigid structures such as wooden dowels, recent studies have progressed to flexible surrogate plants. However, even appropriately-scaled flexible surrogates fail to capture the variability in thallus morphology, flexibility and strength, both within and between individuals, and frontal or planform area over space and time. Furthermore, although there have been a number of field studies, measurements of hydraulic variables have generally been limited to time-averaged at-a-point measurements that aim to approximate the depth-mean velocity. This is problematic because in spatially heterogeneous flows, point measurements are dependent upon the sampling location. Herein, we describe research carried out by the participants in the PISCES work package of the HYDRALAB IV project that sought to address these limitations and assess the level of complexity needed to adequately reproduce the hydrodynamics of the natural system in physical models. We selected an 11 m long × 6 m wide region of a tidal inlet, the Hopavågen Bay, Sør-Trøndelag, Norway, that contained 19 Laminaria digitata thalli and 101 other macroalgae thalli. Two L. digitata specimens ~0.50 m apart were selected for detailed study and a 2 m long × 8 m wide frame was oriented around them by enforcing zero cross-stream discharge at its upstream edge. We then quantified: 1. the mean and turbulent flow field of the undisturbed condition (Case A); 2. the positions, geometrical and biomechanical properties of the macroalgae; and 3. the mean and turbulent flow field after the macroalgae were completely removed (Case B). Later, Case A was replicated in the same location (±0.025 m) before the 19 L. digitata thalli were replaced with 19 "optimized" surrogates (Case C). These three cases were then repeated in the Total Environment Simulator at the University of Hull, UK. Live macroalgae thalli could

  13. A mechanistic description of the global COS cycle consistent with atmospheric measurements and its potential to evaluate gross primary production of vegetation models

    NASA Astrophysics Data System (ADS)

    Launois, Thomas; Peylin, Philippe; Belviso, Sauveur; Bopp, Laurent; Ogée, Jérôme; Wingate, Lisa; Cuntz, Matthias

    2016-04-01

    Accurate estimates of the gross carbon fluxes - photosynthesis and respiration - are essential to predict the ecosystem carbon fluxes and stocks and their evolution in a changing climate. The gross primary productivity (GPP) in the current dynamic global vegetation models (DGVMs), however, shows large differences in terms of mean values, phase and amplitude. As large scale measurements of the GPP are not possible, their estimates are usually based on indirect tracers. Carbonyl sulfide (COS) has been proposed as a tracer of GPP since COS and CO2 are dominantly taken up by plants via the same enzyme during photosynthesis. Thus leaf uptakes of COS and CO2 are often found to be proportional, with a coefficient of proportionality (LRU) that is species-dependant according to laboratory measurements. However contrarily to CO2, atmospheric records of COS over the last decades show a strong seasonal cycle but with no significant trend, which implies roughly equilibrated sources and sinks of COS at the global scale. Most recent estimates of COS uptake by plants using this LRU concept led to larger sinks over land than initially estimated. In order to maintain a closed atmospheric budget, a compensatory COS source had to be found, with the ocean being suggested as the most likely candidate. In this work, we propose a new mechanistically-based parameterization of the major sources and sinks of COS, allowing to close the global atmospheric budget. For the ocean, we used the ocean general circulation and biogeochemistry model NEMO-PISCES to assess the marine source of COS. Using the simulated organic compounds at the surface, we derived a direct source of COS through the COS photo-production as well as an indirect source through the emissions of sulfur compounds (DMS). The resulting simulated global fluxes correspond to a net source of COS of around 800 GgS yr‑1, spatially and temporally consistent with the suggested missing source. For the land, we considered most anoxic

  14. The Umatilla Basin Natural Production Monitoring and Evaluation Project, 2008 Annual Progress Report.

    SciTech Connect

    Contor, Craig R.; Harris, Robin; King, Marty

    2009-06-10

    salmon (O. kisutch), and enhance summer steelhead (O. mykiss). The need for restoration began with agricultural development in the early 1900's that extirpated salmon and reduced steelhead runs (Bureau of Reclamation, BOR 1988). The most notable development was the construction and operation of Three Mile Falls Dam (TMD) and other irrigation projects which dewatered the Umatilla River during salmon migrations. CTUIR and ODFW developed the Umatilla Hatchery Master Plan to restore fisheries to the basin. The plan was completed in 1990 and included the following objectives which were updated in 1999: (1) Establish hatchery and natural runs of Chinook and coho salmon. (2) Enhance existing summer steelhead populations through a hatchery program. (3) Provide sustainable tribal and non-tribal harvest of salmon and steelhead. (4) Maintain the genetic characteristics of salmonids in the Umatilla River Basin. (5) Increase annual returns to Three Mile Falls Dam to 31,500 adult salmon and steelhead. In the past the M&E project conducted long-term monitoring activities as well as two and three-year projects that address special needs for adaptive management. Examples of these projects include adult passage evaluations, habitat assessment surveys (Contor et al. 1995, Conto