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Sample records for bonariensis pisces atherinopsidae

  1. Glycoproteins histochemistry of the gills of Odontesthes bonariensis (Teleostei, Atherinopsidae).

    PubMed

    Díaz, A O; García, A M; Escalante, A H; Goldemberg, A L

    2010-11-01

    The histochemistry of glycoproteins (GP) in the mucous cells of the gills of the silverside Odontesthes bonariensis was identified with: (1) oxidizable vicinal diols; (2) sialic acid and some of their chain variants, carbon 7 ((7) C), carbon 8 ((8) C) or carbon 9 ((9) C); (3) sialic acid residues without O-acyl substitution and with O-acyl substitution at (7) C, (8) C or (9) C; (4) carboxyl groups and (5) sulphate groups. A battery of seven biotinylated lectins allowed GPs sugar residues to be distinguished. Mucous cells showed the presence of neutral, sulphated and sialylated GPs. Dolichos biflorus agglutinin (DBA) and Glycine max agglutinin (SBA) showed strong positive staining; Arachis hypogaea agglutinin (PNA), Ricinus communis agglutinin-I (RCA-I) and Triticum vulgaris agglutinin (WGA) showed moderate staining, while Ulex europaeus agglutinin-I (UEA-I) was completely negative.

  2. 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.

  3. Where does gonadal sex differentiation begin? Gradient of histological sex differentiation in the gonads of pejerrey, Odontesthes bonariensis (Pisces, Atherinidae).

    PubMed

    Strüssmann, Carlos Augusto; Ito, Lauro Satoru

    2005-08-01

    This study investigated the possibility that the histological process of gonadal sex differentiation in pejerrey (Odontesthes bonariensis), a fish with marked temperature-dependent sex determination (TSD), occurs through a predictable gradient of differentiation as opposed to simultaneous or random differentiation throughout the gonad. For this purpose, fish reared at 17 degrees, 24 degrees, and 29 degrees C from hatching were sampled weekly for 11 weeks, fixed, and prepared for histological observation of serial cross-sections of the gonads. The thermal manipulation and sampling procedure ensured the availability of males and females at various degrees of gonadal sex differentiation. The location of the differentiated area(s) was estimated in the right and left gonads of 17 females and 14 males selected among the available specimens so as to represent increasing degrees of differentiation. The analysis revealed that sex differentiation followed a gradient from the anterior to posterior areas of the gonads regardless of sex. Furthermore, plotting of the degree of sex differentiation in the right gonad as a function of the degree of differentiation of the left gonad clearly showed that sex differentiation only begins in the right gonad when 10-30% of the length of the left gonad has already differentiated. The mean rostral edge of the differentiated areas in females was 9% and 10.8% for the left and right gonads, respectively, while for males these values were 7.3% and 7.0%, respectively. Thus, it was established that ovarian and testicular differentiation in pejerrey follow both a cephalocaudal and a left-to-right gradient. Possible explanations for this gradient and its relevance for TSD in pejerrey, that is, as a mechanism to prevent discrepant differentiation of male and female features within the same gonad, are discussed.

  4. 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.

  5. 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.

  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. PISCES: An environment for parallel scientific computation

    NASA Technical Reports Server (NTRS)

    Pratt, T. W.

    1985-01-01

    The parallel implementation of scientific computing environment (PISCES) is a project to provide high-level programming environments for parallel MIMD computers. Pisces 1, the first of these environments, is a FORTRAN 77 based environment which runs under the UNIX operating system. The Pisces 1 user programs in Pisces FORTRAN, an extension of FORTRAN 77 for parallel processing. The major emphasis in the Pisces 1 design is in providing a carefully specified virtual machine that defines the run-time environment within which Pisces FORTRAN programs are executed. Each implementation then provides the same virtual machine, regardless of differences in the underlying architecture. The design is intended to be portable to a variety of architectures. Currently Pisces 1 is implemented on a network of Apollo workstations and on a DEC VAX uniprocessor via simulation of the task level parallelism. An implementation for the Flexible Computing Corp. FLEX/32 is under construction. An introduction to the Pisces 1 virtual computer and the FORTRAN 77 extensions is presented. An example of an algorithm for the iterative solution of a system of equations is given. The most notable features of the design are the provision for several granularities of parallelism in programs and the provision of a window mechanism for distributed access to large arrays of data.

  8. 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.

  9. Promiscuous speciation with gene flow in silverside fish genus Odontesthes (Atheriniformes, Atherinopsidae) from south western Atlantic Ocean basins.

    PubMed

    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.

  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. 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 ...

  12. 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.

  13. Implications of climate change for the reproductive capacity and survival of New World silversides (family Atherinopsidae).

    PubMed

    Strüssmann, C A; Conover, D O; Somoza, G M; Miranda, L A

    2010-11-01

    The New World silversides (family Atherinopsidae) are found in marine, estuarine and inland waters of North, Central and South America, where they are ecologically important as forage fishes and sometimes economically important for commercial and recreational fisheries. This report reviews the knowledge of the reproductive attributes of temperate and subtropical atherinopsids in relation to temperature and discusses the potential effects of climate change on their reproduction and adaptive responses. Their reproductive cycles are primarily entrained by photoperiod with high temperature acting as a limiting factor. They are generally multiple spawners which release successive batches of eggs in spring, but some species can spawn also in autumn and even summer when temperatures do not increase excessively. The decoupling of temperature patterns and photoperiod with further global warming and associated asymmetric thermal fluctuations could lead to spawning at times or temperatures that are unsuitable for larval development and growth. Many members of this family show temperature-dependent sex determination (TSD), where the phenotypic sex of an individual is determined partly or wholly by the temperature experienced during gonadal sex differentiation, and high-temperature induced germ cell degeneration and decreased fertility. The predicted short-term reproductive responses of atherinopsids to climate change therefore include acceleration, shortening or overall disruption of spawning activity, and also more subtle, but nonetheless equally population-threatening, dysfunctions such as highly skewed sex ratios and partial or total loss of fertility. In the case of species with TSD, asymmetric thermal fluctuations could also cause larvae to encounter temperatures lower than normal during early development and be feminized. Such dysfunctions have been documented already in natural populations but are confined so far to landlocked, inland water habitats, perhaps because

  14. 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...

  15. 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...

  16. 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.

  17. The shiny cowbird Molothrus bonariensis in the West Indian region--Biogeographical and ecological implications

    USGS Publications Warehouse

    Cruz, A.; Wiley, J.W.; Nakamura, T.K.; Post, W.; Woods, C.A.

    1989-01-01

    The shiny cowbird (Molthrus bonariensis), an avian brood parasite, is endemic to South America, Trinidad, and Tobago, but during the last 100 years the species has spread through the West Indies. Successful colonization by the shiny cowbird depends on the availablitiy of suitable habitats and host species. As forest fragmentation increases in the West Indies, new hosts, particularly forest species, will be parasitied. Forest fragmentation creates small patches of forests surrounded by open habitat and increases the portion of forest habitat available to cowbirds.

  18. 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.

  19. 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.

  20. 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

  1. PISCES: an integral field spectrograph technology demonstration for the WFIRST coronagraph

    NASA Astrophysics Data System (ADS)

    McElwain, Michael W.; Mandell, Avi M.; Gong, Qian; Llop-Sayson, Jorge; Brandt, Timothy; Chambers, Victor J.; Grammer, Bryan; Greeley, Bradford; Hilton, George; Perrin, Marshall D.; Stapelfeldt, Karl R.; Demers, Richard; Tang, Hong; Cady, Eric

    2016-07-01

    We present the design, integration, and test of the Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES) integral field spectrograph (IFS). The PISCES design meets the science requirements for the Wide-Field InfraRed Survey Telescope (WFIRST) Coronagraph Instrument (CGI). PISCES was integrated and tested in the integral field spectroscopy laboratory at NASA Goddard. In June 2016, PISCES was delivered to the Jet Propulsion Laboratory (JPL) where it was integrated with the Shaped Pupil Coronagraph (SPC) High Contrast Imaging Testbed (HCIT). The SPC/PISCES configuration will demonstrate high contrast integral field spectroscopy as part of the WFIRST CGI technology development program.

  2. Bothriurus bonariensis scorpion venom activates voltage-dependent sodium channels in insect and mammalian nervous systems.

    PubMed

    Dos Santos, Douglas Silva; Carvalho, Evelise Leis; de Lima, Jeferson Camargo; Breda, Ricardo Vaz; Oliveira, Raquel Soares; de Freitas, Thiago Carrazoni; Salamoni, Simone Denise; Domingues, Michelle Flores; Piovesan, Angela Regina; Boldo, Juliano Tomazzoni; de Assis, Dênis Reis; da Costa, Jaderson Costa; Dal Belo, Cháriston André; Pinto, Paulo Marcos

    2016-10-25

    Animal venoms have been widely recognized as a major source of biologically active molecules. Bothriurus bonariensis, popularly known as black scorpion, is the arthropod responsible for the highest number of accidents involving scorpion sting in Southern Brazil. Here we reported the first attempt to investigate the neurobiology of B. bonariensis venom (BBV) in the insect and mammalian nervous system. BBV (32 μg/g) induced a slow neuromuscular blockade in the in vivo cockroach nerve-muscle preparations (70 ± 4%, n = 6, p < 0.001), provoking repetitive twitches and significantly decreasing the frequency of spontaneous leg action potentials (SNCAPs) from 82 ± 3 min(-1) to 36 ± 1.3 min(-1) (n = 6, p < 0.05), without affecting the amplitude. When tested in primary cultures of rat hippocampal cells, BBV induced a massive increase of Ca(2+) influx (250 ± 1% peak increase, n = 3, p < 0.0001). The disturbance of calcium homeostasis induced by BBV on the mammalian central nervous system was not accompanied by cellular death and was prevented by the co-treatment of the hippocampal cells with tetrodotoxin, a selective sodium channel blocker. The results suggest that the biological activity of BBV is mostly related to a modulation of sodium channels function. Our biological activity survey suggests that BBV may have a promising insecticidal and therapeutic potential.

  3. 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.

  4. 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.

  5. Seasonal changes and endocrine regulation of pejerrey (Odontesthes bonariensis) oogenesis in the wild.

    PubMed

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

    2014-09-01

    The goal of this study was to evaluate the essential components controlling the brain-pituitary-gonad axis during pejerrey (Odontesthes bonariensis) oogenesis in the wild. Ovarian developmental stages from vitellogenesis up to ovulation were associated with increasing day length and water temperatures below 21°C (winter and beginning of spring). Gonadal regression was observed when water temperature exceeded this value or when photoperiod decreased. Most females were arrested at primary growth stage during summer (high temperature) or at cortical alveoli stage between autumn and beginning of winter (short photoperiod). Plasma E2 and transcript levels of fshr, cyp19a1b and cyp19a1a increased during vitellogenesis, while fshb remained high at all vitellogenic stages. A significant correlation between plasma sex steroids (T and E2) and cyp19a1b as well as lhcgr transcript levels was observed during vitellogenesis, suggesting a steroid positive feedback. Gnrh-I, Gth subunits and lhcgr transcript levels increased significantly during late vitellogenesis and final maturation. Present results suggest that pejerrey vitellogenesis is controlled by Fsh/Fshr, stimulating gonadal aromatase and estradiol synthesis. Moreover, the increase of testosterone and estradiol during final vitellogenesis could induce coordinately the functioning of the Gnrh/Lh system (perhaps through brain P450 aromatase stimulation and brain estradiol increase) and the gonadal Lhcgr synthesis to promote the final maturation of oocytes. All these stimulation mechanisms of gonadal development would be possible only under permissive environmental conditions.

  6. Thermal and endocrine regulation of gonadal apoptosis during sex differentiation in pejerrey Odontesthes bonariensis.

    PubMed

    Yamamoto, Y; Hattori, R S; Kitahara, A; Kimura, H; Yamashita, M; Strüssmann, C A

    2013-01-01

    The fate of the differentiating gonads in pejerrey Odontesthes bonariensis is determined by the environmental water temperature experienced by the larvae during the critical period of sex determination. We previously reported a link between apoptosis, temperature and sex differentiation in this species. To clarify this link, we subjected larvae to thermal and endocrine treatments between hatching and the onset of histological sex differentiation of the gonads and assessed the patterns of gonadal development and apoptosis by light microscopic histology and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) analysis, respectively. Apoptotic labeling was widespread among somatic cells of the anterior region of the right gonads of fish reared at the male-producing temperature (MPT) and part of the fish at the mixed sex-producing temperature prior to sex differentiation. In contrast, TUNEL-positive cells were rarely observed in gonads at the female-producing temperature (FPT). Administration of exogenous estrogen completely prevented MPT-induced masculinization, induced feminization and reduced gonadal apoptosis, whereas an aromatase inhibitor (fadrozole) induced TUNEL signals in the gonads of FPT-reared larvae. These results provide strong evidence that apoptosis in somatic cells in the right lobe of the gonads might play a key role in testicular differentiation in pejerrey and that estrogens are involved in the regulation of this process.

  7. 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

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

    PubMed

    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.

  9. VizieR Online Data Catalog: HST imaging of Pisces A and B (Tollerud+, 2016)

    NASA Astrophysics Data System (ADS)

    Tollerud, E. J.; Geha, M. C.; Grcevich, J.; Putman, M. E.; Weisz, D. R.; Dolphin, A. E.

    2016-11-01

    The observations of Pisces A and B were taken as part of HST program GO-13745 (Cycle 22, PI Tollerud, executed 2014 October 30-November 8). Pisces A and B were observed for a single orbit each with ACS/WFC, using the F606W and F814W filters. (2 data files).

  10. 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.

  11. Kisspeptin system in pejerrey fish (Odontesthes bonariensis). Characterization and gene expression pattern during early developmental stages.

    PubMed

    Tovar Bohórquez, M Oswaldo; Mechaly, Alejandro S; Hughes, Lily C; Campanella, Daniela; Ortí, Guillermo; Canosa, Luis F; Somoza, Gustavo M

    2017-02-01

    In vertebrates, kisspeptins and their receptors are known to be related to puberty onset and gonadal maturation, however, there are few studies concerning their role in early development. Here, we characterize the kisspeptin system in the pejerrey, Odontesthes bonariensis, a fish with strong temperature-dependent sex determination. We reconstructed the phylogenetic history of the two ligands (kiss1 and kiss 2) and two receptors (kissr2 and kissr3) in pejerrey in the context of recent classifications of bony fishes, determined their tissue distribution and documented the early expression pattern of these ligands and receptors. Phylogenetic analysis of these gene families clearly resolved the percomorph clade and grouped pejerrey with Beloniformes. Paralogous sets of genes putatively arising from the teleost-specific genome duplication event (3R) were not detected. Kisspeptins and their receptors showed a wide tissue distribution in adult pejerrey, including tissues not related to reproduction. In larvae reared at 24°C, the four kisspeptin elements were expressed in the head from week 1 to week 8 of life, with no differences in transcript levels. Larvae kept at a female-producing temperature (17°C) did not show statistically significant differences in the transcript levels of all analyzed genes during the sex determination/differentiation period; however, in those larvae raised at male producing temperature (29°C), kiss2 levels were increased at week 4 after hatching. These results showed that all members of the kisspeptin system are expressed at this early period, and the increase of kiss2 transcripts at week 4 could be interpreted as it would be related to the differentiation of the brain-pituitary axis in male development.

  12. 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.

  13. Biology of the introduced biocontrol agent Microctonus hyperodae (Hymenoptera: Braconidae) and its host Listronotus bonariensis (Coleoptera: Curculionidae) in northern New Zealand.

    PubMed

    Barker, Gary M

    2013-10-01

    The South American weevil Listronotus bonariensis (Kuschel) is an important pest of pastures in New Zealand. As a component of management strategies for this pest, the South American parasitoid Microctonus hyperodae Loan (Hymenoptera: Braconidae) was released in northern New Zealand during 1991 as a biological control agent. Over the subsequent 5-6 yr, the reproductive biology of M. hyperodae and its relationship to, and effects on, the reproductive phenology and fitness of L. bonariensis were studied at three sites. M. hyperodae was first recovered in the field in December 1991. Subsequently, the incidence of parasitism in L. bonariensis increased to seasonal maxima of 75-90%. There was variable synchrony between parasitoid generations and the two generations of its host, leading to marked seasonal variation in rates of parasitism and parasitoid abundance. Despite marked inter-year variation, abundance of host adult and egg populations declined in the presence of parasitoids. Parasitized host females had lower ovarian maturity scores, had lower egg loads, and exhibited less investment in wing muscle development than females that had escaped parasitism. There was almost complete elimination of egg maturation in parasitized females and these hosts contributed little to population recruitment. Rate of buildup and seasonal maxima in parasitism, frequency of superparasitism, adult abundances, and wing muscle development in adult L. bonariensis varied among the three sites in a manner that was only partially related to climate differences across the 1.83° gradient of latitude. Site effects were weak to absent in measures of reproductive condition in L. bonariensis females.

  14. 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

  15. 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.

  16. 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.

  17. Measurement of parallel ion energy distribution function in PISCES plasma

    SciTech Connect

    Tynan, G.R.; Goebel, D.M.; Conn, R.W.

    1987-08-01

    The PISCES facility is used to conduct controlled plasma-surface interaction experiments. Plasma parameters typical of those found in the edge plasmas of major fusion confinement experiments are produced. In this work, the energy distribution of the ion flux incident on a material surface is measured using a gridded energy analyzer in place of a material sample. The full width at half maximum energy distribution of the ion flux is found to vary from 10 eV to 30 eV both hydrogen and deuterium plasmas. Helium plasmas have a much lower FWHM energy spread than hydrogen and deuterium plasmas. The FWHM ion energy spread is found to be linearly related to the electron temperature. The most probable ion energy is found to be linearly related to the bias applied to the energy analyzer. Other plasma parameters have a weak influence upon the energy distribution of the ion flux. Two possible physical mechanisms for producing the observed results are introduced and suggestions for further work are made. The impact of the reported measurements on the materials experiments conducted in the PISCES facility are discussed and recommendations for future experiments are made. 11 refs., 13 figs.

  18. 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.

  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; Stapelfeldt, Karl; Hilton, George; Sayson, Jorge Llop; Perrin, Marshall; Demers, 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 (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.

  20. Evaluation of the Health Status of the Silverside (Odontesthes bonariensis) at a RAMSAR Site in South America.

    PubMed

    Ballesteros, M L; Hued, A C; Gonzalez, M; Miglioranza, K S B; Bistoni, M A

    2017-03-16

    The objective of this work was to evaluate the health status of an economic and ecologically important fish species from Mar Chiquita Lake, a RAMSAR site located in Cordoba, Argentina, relative to the levels of selected persistent organic pollutants (POPs) in lake water and fish tissues. Odontesthes bonariensis was used as a model species, and its health was estimated by means of histological indices in gills and liver. Sampling was performed according to rainy and dry seasons (i.e. dry, rainy and post-rainy). Gill and liver histopathology were evaluated by semi-quantitative indices and morphometric analysis. Although epithelial lifting in gills and lipid degeneration in liver were frequently registered, they are considered as reversible if environmental conditions improve. During rainy and post-rainy seasons fish presented significantly higher scores of liver and total indices. These higher index scores were correlated with increased levels of POPs in gill and liver tissue. Therefore, preventive measures are needed to mitigate the entry of these compounds into the lake.

  1. PISCES-v2: an ocean biogeochemical model for carbon and ecosystem studies

    NASA Astrophysics Data System (ADS)

    Aumont, O.; Ethé, C.; Tagliabue, A.; Bopp, L.; Gehlen, M.

    2015-08-01

    PISCES-v2 (Pelagic Interactions Scheme for Carbon and Ecosystem Studies volume 2) is a biogeochemical model which simulates the lower trophic levels of marine ecosystems (phytoplankton, microzooplankton and mesozooplankton) and the biogeochemical cycles of carbon and of the main nutrients (P, N, Fe, and Si). The model is intended to be used for both regional and global configurations at high or low spatial resolutions as well as for short-term (seasonal, interannual) and long-term (climate change, paleoceanography) analyses. There are 24 prognostic variables (tracers) including two phytoplankton compartments (diatoms and nanophytoplankton), two zooplankton size classes (microzooplankton and mesozooplankton) and a description of the carbonate chemistry. Formulations in PISCES-v2 are based on a mixed Monod-quota formalism. On the one hand, stoichiometry of C / N / P is fixed and growth rate of phytoplankton is limited by the external availability in N, P and Si. On the other hand, the iron and silicon quotas are variable and the growth rate of phytoplankton is limited by the internal availability in Fe. Various parameterizations can be activated in PISCES-v2, setting, for instance, the complexity of iron chemistry or the description of particulate organic materials. So far, PISCES-v2 has been coupled to the Nucleus for European Modelling of the Ocean (NEMO) and Regional Ocean Modeling System (ROMS) systems. A full description of PISCES-v2 and of its optional functionalities is provided here. The results of a quasi-steady-state simulation are presented and evaluated against diverse observational and satellite-derived data. Finally, some of the new functionalities of PISCES-v2 are tested in a series of sensitivity experiments.

  2. Histological process and dynamics of germ cell degeneration in pejerrey Odontesthes bonariensis larvae and juveniles during exposure to warm water.

    PubMed

    Ito, Lauro Satoru; Yamashita, Michiaki; Strüssmann, Carlos Augusto

    2003-06-01

    Elevated temperature causes degeneration and disappearance of the germ cells in the males of scrotal mammals. It was recently shown that heat-induced germ cell degeneration occurs also in fish but, unlike in mammals, it occurs not only in males but also in females. The purpose of this study was to clarify the histological process and dynamics of heat-induced germ cell disappearance in pejerrey Odontesthes bonariensis larvae and juveniles. Monosex and mixed-sex fish produced by thermal manipulation of sex (temperature-dependent sex determination) were subjected to 29 degrees C for periods between 1 and 12 weeks, and used to analyze, by histological methods, the changes in gonadal size and the number of normal and degenerating germ cells. Groups exposed to 29 degrees C for 8-12 weeks were subsequently transferred to 24 degrees C to verify if any gonadal damage would be permanent. Germ cell degeneration, histologically characterized by nuclear pyknosis or eosinophilia and cytoplasmic eosinophilia, was observed with increasing frequency at higher temperatures (29>24> 17 degrees C) and more in males than in females. Clear degenerative changes in the germinal epithelium usually began within one week of exposure to 29 degrees C and appeared clearer in females than in males. Complete loss of germ cells was observed only in individuals exposed for periods of 8-12 weeks to 29 degrees C but no treatment produced 100% sterile fish. Germ cells that remained in the gonads after exposure to 29 degrees C retained the capacity to rapidly recolonize germ cell-depleted areas, suggesting that the associated somatic cells in the gonads are little or not affected by this temperature.

  3. 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.

  4. PISCES field chemical emissions monitoring project: Site 21 emissions report

    SciTech Connect

    1995-12-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 21. Site 21 is a pilot-scale electrostatic precipitator and wet flue gas desulfurization (FGD) system. The flue gas for the pilot unit is provided by an adjacent power plant boiler which bums a medium-sulfur bituminous, coal. The primary objective in the Site 21 sampling and analytical program was to quantify the various components of variance in the measurement of trace chemical species. In addition to the replicate sample trains typically conducted at previous PISCES field measurements, duplicate analyses and duplicate (simultaneous) sample trains were also conducted. This enabled the variance due to sampling, analytical, and process conditions to be estimated. The objective of this report is to transmit the detailed data to the U.S. Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts - as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites. An assessment of data from all plants that have been tested is presented in the Electric Utility Trace Substances Synthesis Report.

  5. Fokker-Planck Modelling of PISCES Linear Divertor Simulator

    NASA Astrophysics Data System (ADS)

    Batishchev, O. V.; Krasheninnikov, S. I.; Schmitz, L.

    1996-11-01

    The gas target operating regime in the PISCES [1] linear divertor simulator is characterized by a relatively high plasma density, 2.5 × 10^19 m-3, and low temperature, 8 eV, in the middle section of an ≈ 1 m long plasma column. Near the target, the plasma temperature and density as measured by Langmuir probes drop to 2 eV and 3.5 × 10^18 m-3, respectively, as a result of electron energy loss due to dissociation, ionization, and radiation. Such a sharp gradient in the plasma parameters can enhance non-local effects. To study these, we performed kinetic simulations of the relaxation of the electron energy distribution function on the experimentally measured background plasma using the adaptive finite-volumes code ALLA [2]. We discuss the effects of the observed incompletely equilibrated electron distribution function on key plasma parameter measurements and plasma - neutral particle interactions. cm [1] L.Schmitz et al., Physics of Plasmas 2 (1995) 3081. cm [2] A.A.Batishcheva et al., Physics of Plasmas 3 (1996) 1634. cm ^*Under U.S. DoE Contracts No.DE-FG02-91-ER-54109 at MIT, DE-FG02-88-ER-53263 at Lodestar, and DE-FG03-95ER54301 at UCSD.

  6. 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

  7. Spectroscopic studies of carbon impurities in PISCES-A

    SciTech Connect

    Ra, Y.; Hirooka, Y.; Leung, W.K.; Conn, R.W. . Inst. of Plasma and Fusion Research); Pospieszczyk, A. . Inst. fuer Plasmaphysik)

    1989-08-01

    The graphite used for the limiter of the tokamak reactor produces carbon-containing molecular impurities as a result of the interactions with the edge plasma. The behavior of these molecular impurities has been studied using emission spectroscopy. The present study includes: finding molecular bands and atomic lines in the visible spectral range which can be used for the study of the molecular impurities, studying the breakup processes of the molecular impurities on their way from the source into the plasma, developing a spectroscopic diagnostic method for the absolute measurement of the molecular impurity flux resulting from graphite erosion. For these studies, carbon-containing molecules such as CH{sub 4}, C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, and CO{sub 2} were injected into the tokamak-boundary,like plasma generated by PISCES-A. The spectrograms of these gases were taken. Many useful bands and lines were determined from the spectrograms. The breakup processes of these gases were studied by observing the spatial profiles of the emission of the molecules and their radicals for different plasma conditions. For the absolute measurement of the eroded molecular impurity flux, the photon efficiency of the lines and bands were found by measuring the absolute number of the emitted photons and injected gas molecules. The chemical sputtering yield of graphite by hydrogen plasma was spectroscopically measured using the previously obtained photon efficiencies. It showed good agreement with results obtained by weight loss measurements. 16 refs., 7 figs., 1 tab.

  8. PISCES High Contrast Integral Field Spectrograph Simulations and Data Reduction Pipeline

    NASA Technical Reports Server (NTRS)

    Llop Sayson, Jorge Domingo; Memarsadeghi, Nargess; McElwain, Michael W.; Gong, Qian; Perrin, Marshall; Brandt, Timothy; Grammer, Bryan; Greeley, Bradford; Hilton, George; Marx, Catherine

    2015-01-01

    The PISCES (Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies) is a lenslet array based integral field spectrograph (IFS) designed to advance the technology readiness of the WFIRST (Wide Field Infrared Survey Telescope)-AFTA (Astrophysics Focused Telescope Assets) high contrast Coronagraph Instrument. We present the end to end optical simulator and plans for the data reduction pipeline (DRP). The optical simulator was created with a combination of the IDL (Interactive Data Language)-based PROPER (optical propagation) library and Zemax (a MatLab script), while the data reduction pipeline is a modified version of the Gemini Planet Imager's (GPI) IDL pipeline. The simulations of the propagation of light through the instrument are based on Fourier transform algorithms. The DRP enables transformation of the PISCES IFS data to calibrated spectral data cubes.

  9. PISCES field chemical emission measurement program: Recent emission results from oil-fired power plants

    SciTech Connect

    Chu, P.; McDannel, M.; Behrens, G.

    1995-09-01

    Title III of the 1990 Clean Air Act Amendments (CAAA) mandated that the U.S. Environmental Protection Agency (EPA) evaluate emissions and health risks associated with 189 hazardous air pollutants emitted from the stacks of electric utility steam generating stations. EPA is currently proceeding with the electric utility study and expects to summarize its findings in a report to Congress in 1995. In anticipation of the CAAA, the Electric Power Research Institute (EPRI) initiated the Power Plant Integrated Systems: Chemical Emission Studies (PISCES) research program. The PISCES program has sampled over a range of fuels, boiler configurations, flue gas desulfurization systems, and NO{sub x} control technologies. This paper highlights some of the recent results and issues from field sampling programs at utility oil-fired power plant sites.

  10. 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

  11. 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).

  12. Synonymous codon usage pattern in mitochondrial CYB gene in pisces, aves, and mammals.

    PubMed

    Uddin, Arif; Chakraborty, Supriyo

    2017-03-01

    Cytochrome b (CYB) protein plays an important role in complex III of the mitochondrial oxidative phosphorylation. Codon usage is the phenomenon of non-uniform usage of synonymous codons. In the present study, we report the pattern of codon usage in MT-CYB gene using various codon usage parameters. Nucleotide composition such as % of C and T was higher than A and G in pisces. In aves, % of A and C was higher than T and G but in mammals, A and T was higher than C and G. Heat map shows that AT-ending codons were mostly negative and GC-ending codons were mostly positive. From the heat map based on RSCU values, it is evident that codon usage prefers A/C at the third codon position and it was less towards T/G in its third codon position. The codons absent in pisces were AGT (except Toxotes chatareus), TGT, and CAG (except Elasma zonatum). The codons such as AGT (except Falco peregrinus), CGT (except Vidua chalybeata), and ACG (except Aythya americana) were absent in aves whereas, in mammals, the absent codons were namely CAG (except Canis familiaris) and ACG (except Rattus norvegicus). Codon usage bias was low in pisces, aves, and mammals. The frequency of leucine was the highest in the amino acid and cysteine was the lowest. Correlation analysis further suggests that mutation pressure is mainly responsible for codon usage pattern. Natural selection might also play a vital role in codon usage pattern but it was weaker than mutation pressure.

  13. 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

  14. 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.

  15. Initial HI results from the Arecibo Pisces-Perseus Supercluster Survey

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

    The Arecibo Pisces-Perseus Supercluster Survey is a targeted HI survey of galaxies that began its second observing season in October 2016. The survey is conducted by members of the Undergraduate ALFALFA Team (UAT) and extensively involves undergraduates in observations, data reduction, and analysis. It aims to complement the HI sources identified by the ALFALFA extragalactic HI line survey by probing deeper in HI mass (to lower masses) than the legacy survey itself. Measurements of the HI line velocity widths will be combined with uniform processing of images obtained in the SDSS and GALEX public databases to localize the sample within the baryonic Tully Fisher relation, allowing estimates of their redshift-independent distances and thus their peculiar velocities.The survey is designed to constrain Pisces-Perseus Supercluster infall models by producing 5-σ detections of infall velocities to a precision of about 500 km/s. By targeting galaxies based on SDSS and GALEX photometry, we have achieved detection rates of 68% of the galaxies in our sample. We will discuss the target selection process, HI velocities and mass estimates from the 2015 fall observing season, preliminary results from 2016 observations, and preliminary comparisons with inflow models predicted by numerical simulations.This work has been supported by NSF grants AST-1211005, AST-1637339, AST-1637262.

  16. 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.

  17. 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.

  18. Helminth parasites of Girardinichthys multiradiatus (Pisces: Goodeidae) in the upper Lerma River sub-basin, Mexico.

    PubMed

    Sánchez-Nava, Petra; Salgado-Maldonado, Guillermo; Soto-Galera, Eduardo; Cruz, Blanca Jaimes

    2004-08-01

    Thirteen helminth species were recorded during a helminthological examination of 754 Girardinichthys multiradiatus (Meek) (Pisces: Goodeidae) collected from 20 localities in the upper Lerma River sub-basin on the highland plateau of Mexico. The study constitutes a complete and extensive inventory of the helminth parasites of this freshwater fish species across its entire current geographic distribution. The collected species included one adult trematode, three metacercariae, one monogenean, one adult cestode, three metacestodes, three nematode larvae and one cystacanth. The records of the metacercariae of Tylodelphys sp. and Ochetosoma brevicaecum, the larvae of the nematodes Contracaecum sp. and Falcaustra sp. and the cystacanth of Polymorphus brevis are all new records for G. multiradiatus. The metacercariae of Tylodelphys sp. were the most widespread and prevalent species in the sample, being collected from 15 of the 20 sampling localities, with a prevalence of 3.2-72.2%. The data indicate the helminth parasite community of G. multiradiatus to be relatively poor when compared with the helminth communities of freshwater fish from other parts of Mexico. This community is subject to colonization by generalist helminth species, mostly transported by birds. A further component of this community consists of helminth species that have been introduced anthropogenically.

  19. HI data reduction for the Arecibo Pisces-Perseus Supercluster Survey

    NASA Astrophysics Data System (ADS)

    Davis, Cory; Johnson, Cory; Craig, David W.; Haynes, Martha P.; Jones, Michael G.; Koopmann, Rebecca A.; Hallenbeck, Gregory L.; Undergraduate ALFALFA Team

    2017-01-01

    The Undergraduate ALFALFA team is currently focusing on the analysis of the Pisces-Perseus Supercluster to test current supercluster formation models. The primary goal of our research is to reduce L-band HI data from the Arecibo telescope. To reduce the data we use IDL programs written by our collaborators to reduce the data and find potential sources whose mass can be estimated by the baryonic Tully-Fisher relation, which relates the luminosity to the rotational velocity profile of spiral galaxies. Thus far we have reduced data and estimated HI masses for several galaxies in the supercluster region.We will give examples of data reduction and preliminary results for both the fall 2015 and 2016 observing seasons. We will also describe the data reduction process and the process of learning the associated software, and the use of virtual observatory tools such as the SDSS databases, Aladin, TOPCAT and others.This research was supported by the NSF grant AST-1211005.

  20. 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.

  1. 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.

  2. [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).

  3. [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.

  4. 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.

  5. 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.

  6. DISCOVERY OF AN ULTRA-DIFFUSE GALAXY IN THE PISCES-PERSEUS SUPERCLUSTER

    SciTech Connect

    Martínez-Delgado, David; Grebel, Eva K.; Läsker, Ronald; Sharina, Margarita; Karachentsev, Igor D.; Toloba, Elisa; Romanowsky, Aaron J.; Fliri, Jürgen; Valls-Gabaud, David; Chonis, Taylor S.; Forbes, Duncan A.; Gallego-Laborda, J.; Teuwen, Karel; Gómez-Flechoso, M. A.; and others

    2016-04-15

    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 (μ{sub V} = 24.8 mag arcsec{sup −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 (R{sub e}(V) = 12″) and proximity (15′) to the well-known dwarf spheroidal galaxy And II. Its red color (V − I = 1.0), shallow Sérsic index (n{sub V} = 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 (V{sub h} = 5450 ± 40 km s{sup −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 R{sub e} ∼ 4.7 kpc and M{sub V} ∼ −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.

  7. Deuterium retention in tungsten after heavy ion damage and hydrogen isotope exchange in PISCES

    NASA Astrophysics Data System (ADS)

    Barton, J. L.; Wang, Y. Q.; Dittmar, T.; Doerner, R. P.; Tynan, G. R.

    2014-08-01

    The effect of H isotope exchange and radiation damage on the retention of D in W was examined in the PISCES linear plasma device. W samples were treated with D plasma at low sample temperatures (473 K), with a fluence of 1026 ions/m2 and ion energies of 150 eV. Each sample was then exposed to varying doses of H plasma with similar sample temperature and plasma conditions to fluences ranging from 0 to 1026 ions/m2, to examine the effectiveness of isotope exchange as a means of tritium removal. The D(3He, p)4He nuclear reaction was used to measure D concentration profiles up to a depth of 7.7 μm. Thermal desorption spectroscopy (TDS) was used to determine the D retained throughout the bulk of the sample. Isotope exchange allows for a unique study of atomic migration by separately examining the diffusion of implanted atoms from those bombarding the surface. D atoms are exchanged out of traps as a result of H plasma bombardment and diffuse until either falling into another trap or reaching the surface to recombine and escape. Radiation damage at levels of 0.01, 0.1, and 1 displacements per atom (dpa) was carried out before plasma exposure on some samples with 2 MeV Cu ions as a surrogate for damage caused by fusion neutrons. The Cu ion damage was compared to damage induced by 6 MeV W ions to see if there is an effect of Cu contamination on retention. We saw little difference in Cu versus W ion damage at low dpa, but at 1 dpa, where Cu content reached 65 appm, contamination seems to be significant. Retention measurements showed that ion damage has little effectiveness on isotope removal at these sample temperatures; however, there is evidence to suggest that the trapping mechanisms in W change as damage is increased.

  8. Studies of lithium deposition and D retention on tungsten samples exposed to Li-seeded plasmas in PISCES-A

    NASA Astrophysics Data System (ADS)

    Tabarés, F. L.; Alegre, D.; Baldwin, M.; Nishijima, D.; Simmonds, M.; Doerner, R.; Alves, E.; Mateus, R.

    2017-04-01

    The interaction between lithium-seeded deuterium plasmas and tungsten targets has been studied in the PISCES-A divertor plasma simulator. Tungsten samples, of ITER-grade, with a diameter of 25 and 2 mm thick, were held at temperatures ranging from 403 to 873 K and exposed to Li/D plasmas under different plasma conditions and fixed total fluences of 5 ×1025 m‑2, with typical particle flux values of (1–5) × 1022 m‑2 s‑1. The deuterium and lithium contents of the samples after irradiation were analyzed by thermal desorption spectroscopy and nuclear reaction analysis (NRA). No lithium deposition was found within the sensitivity range of NRA, except for the cold (403 K) sample on which a layer with Li atomic density below 2 × 1022 m‑2 was detected. Deuterium retention values in the range of 1018 m‑2 were measured, even for the Li deposition conditions.

  9. 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

  10. Stochastic parameterizations of biogeochemical uncertainties in a 1/4° NEMO/PISCES model for probabilistic comparisons with ocean color data

    NASA Astrophysics Data System (ADS)

    Garnier, F.; Brankart, J.-M.; Brasseur, P.; Cosme, E.

    2016-03-01

    In spite of recent advances, biogeochemical models are still unable to represent the full complexity of natural ecosystems. Their formulations are mainly based on empirical laws involving many parameters. Improving biogeochemical models therefore requires to properly characterize model uncertainties and their consequences. Subsequently, this paper investigates the potential of using random processes to simulate some uncertainties of the 1/4° coupled Physical-Biogeochemical NEMO/PISCES model of the North Atlantic ocean. Starting from a deterministic simulation performed with the original PISCES formulation, we propose a generic method based on AR(1) random processes to generate perturbations with temporal and spatial correlations. These perturbations are introduced into the model formulations to simulate 2 classes of uncertainties: the uncertainties on biogeochemical parameters and the uncertainties induced by unresolved scales in the presence of non-linear processes. Using these stochastic parameterizations, a probabilistic version of PISCES is designed and a 60-member ensemble simulation is performed. With respect to the simulation of chlorophyll, the relevance of the probabilistic configuration and the impacts of these stochastic parameterizations are assessed. In particular, it is shown that the ensemble simulation is in good agreement with the SeaWIFS ocean color data. Using these observations, the statistical consistency (reliability) of the ensemble is evaluated with rank histograms. Finally, the benefits expected from the probabilistic description of uncertainties (model error) are discussed in the context of future ocean color data assimilation.

  11. [Reproduction and growth of the fish Lutjanus guttatus (Pisces: Lutjanidae) in the Gulf of Nicoya, Costa Rica].

    PubMed

    Rojas, Rosa L Soto; Mejía-Arana, Fernando; Palacios, J A; Hiramatsu, Kazuhito

    2009-01-01

    Reproduction and growth of the fish Lutjanus guttatus (Pisces: Lutjanidae) in the Gulf of Nicoya, Costa Rica. The fish Lutjanus guttatus is important in the fisheries of Golfo de Nicoya, Costa Rica where they are captured with varied gear mainly by the artisanal fleet. We measured specimens from the commercial catch of 2002-2006. Gonadal state was determined macroscopically and age with otoliths The total length-total weight relationship was y = 0.0236x(2.8153) and total length-eviscerated weight y = 0.0216x(2.8129). Simplified relationships were y = 0.0173x3 and y = 0.0162x3. There is year-round reproduction with peaks in March (dry season) and September (rainy season). Male-female sexual ratio was 1:1. The age-length key for the gulf shows availability until the 6 years of age. The von Bertalanffy growth curve is L(t) = 65,9 (1-e(-0.13(t+2,66))).

  12. Seasonality of parasitic copepods on bullseye puffer, Sphoeroides annulatus (Pisces: Tetraodontidae), from the northwestern coast of Mexico.

    PubMed

    Morales-Serna, Francisco Neptalí; Rubio-Godoy, Miguel; Gómez, Samuel

    2011-08-01

    Seasonal occurrence of parasitic copepods in wild bullseye puffer, Sphoeroides annulatus (Pisces: Tetraodontidae), was analyzed in conjunction with variation of biotic and abiotic factors. Eleven samples were taken between February 2007 and February 2008 in Santa María La Reforma lagoon (northwestern coast of México). In total, 337 fish was examined; 5 parasitic copepod species were observed, including Acantholochus zairae , Caligus serratus , Lepeophtheirus simplex , Pseudochondracanthus diceraus , and Parabrachiella sp. The most common species were L. simplex , P. diceraus, and C. serratus (overall prevalence, 59, 53, and 35%, respectively), which significantly varied in prevalence and mean intensity between sampling months. A seasonal pattern was only observed for L. simplex, with higher infection levels in the warmest month than in the coldest month. Statistical analyses indicated that the intensity of L. simplex was positively correlated with water temperature. There were no significant differences in prevalence and intensity of infection among female and male hosts. At the component community level, species richness ranged between 4 and 5 during most of the study period, and no seasonality was observed in the number of individuals, Shannon diversity index, evenness index, or the Berger-Parker dominance index. At the infracommunity level, 4 descriptors used (mean species richness, mean number of individuals, mean Brillouin's diversity index, and mean Berger-Parker index) varied significantly between sampling months, but no seasonality was observed, except for a slight increase in the number of individuals during the warmest month. A significant positive association was detected between number of individuals and water temperature and between host size and both species richness and number of individuals. This is the first account of the ecology of these 5 parasitic copepods. Although no significant association was detected between fish condition factor and the

  13. Extending ALFALFA in the Direction of the Pisces-Perseus Supercluster with the Arecibo L-Band Wide Receiver

    NASA Astrophysics Data System (ADS)

    O'Donoghue, Aileen A.; Haynes, Martha P.; Koopmann, Rebecca A.; Jones, Michael G.; Hallenbeck, Gregory L.; Giovanelli, Riccardo; Hoffman, Lyle; Craig, David W.; Undergraduate ALFALFA Team

    2017-01-01

    We have completed three “Harvesting ALFALFA” Arecibo observing programs in the direction of the Pisces-Perseus Supercluster (PPS) since ALFALFA observations were finished in 2012. The first was to perform follow-up observations on high signal-to-noise (S/N > 6.5) ALFALFA detections needing confirmation and low S/N sources lacking optical counterparts. A few more high S/N objects were observed in the second program along with targets visually selected from the Sloan Digital Sky Survey (SDSS). The third program included low S/N ALFALFA sources having optical counterparts with redshifts that were unknown or differed from the ALFALFA observations. It also included more galaxies selected from SDSS by eye and by Structured Query Language (SQL) searches with parameters intended to select galaxies at the distance of the PPS (~6,000 km/s). We used pointed basic Total-Power Position-Switched Observations in the 1340 - 1430 MHz ALFALFA frequency range. For sources of known redshift, we used the Wideband Arecibo Pulsar Processors (WAPP’s) , while for sources of unknown redshift we utilized a hybrid/dual bandwidth Doppler tracking mode using the Arecibo Interim 50-MHz Correlator with 9-level sampling.Results confirmed that a few high S/N ALFALFA sources are spurious as expected from the work of Saintonge (2007), low S/N ALFALA sources lacking an optical counterpart are all likely to be spurious, but low S/N sources with optical counterparts are generally reliable. Of the optically selected sources, about 80% were detected and tended to be near the distance of the PPS.This work has been supported by NSF grant AST-1211005.

  14. 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.

  15. Thermal conductivity reduction of tungsten plasma facing material due to helium plasma irradiation in PISCES using the improved 3-omega method

    NASA Astrophysics Data System (ADS)

    Cui, Shuang; Simmonds, Michael; Qin, Wenjing; Ren, Feng; Tynan, George R.; Doerner, Russell P.; Chen, Renkun

    2017-04-01

    The near-surface region of plasma facing material (PFM) plays an important role in thermal management of fusion reactors. In this work, we measured thermal conductivity of tungsten (W) surface layers damaged by He plasma in PISCES at UCSD. We studied the damage effect on both bulk, and thin film, W. We observed that the surface morphology of both bulk and thin film was altered after exposure to He plasma with the fluence of 1 × 1026 m-2 (bulk) and 2 × 1024 m-2 (thin film). Transmission electron microscopy (TEM) analysis reveals that the depth of the irradiation damaged layer was approximately 20 nm on the bulk W exposed to He plasma at 773 K for 2000 s. In order to measure the thermal conductivity of this exceedingly thin damaged layer in the bulk W, we adopted the well-established '3-omega' method and employed novel nanofabrication techniques to improve the measurement sensitivity. For the damaged W thin film sample, we measured the reduction in electrical conductivity and used the Wiedemann-Franz (W-F) law to extract the thermal conductivity. Results from both measurements show that thermal conductivity in the damaged layers was reduced by at least ∼80% compared to that of undamaged W. This large reduction in thermal conductivity can be attributed to the scattering of electrons, the dominant heat carriers in W, caused by defects introduced by He plasma irradiation.

  16. [Variability in the relative abundance, size structure and sex ratio of the dolphinfish Coryphaena hippurus (Pisces: Coryphaenidae) in the Gulf of Tehuantepec, México].

    PubMed

    Alejo-Plata, Carmen; Gómez, José Luis; Serrano-Guzmán, Saúl J

    2014-06-01

    Variability in the relative abundance, size structure and sex ratio of the dolphinfish Coryphaena hippurus (Pisces: Coryphaenidae) in the Gulf of Tehuantepec, México. The dolphinfish (Coryphaena hippurus), is an oceanic epipelagic fish found worldwide in tropical and subtropical waters, with a high dispersal capability via large-scale migrations. This fast-swimming top-level predator is abundant in the Gulf of Tehuantepec, where it is caught incidentally by artisanal fisheries, and represents a target species for both recreational and commercial fisheries in Mexico, Ecuador, Peru and Central America. Nowadays, local fishery information on this species is scarce, thus our objective was to analyze the size structure by sex and the catch-per-unit-effort (CPUE) tendency of dolphinfish caught in the Gulf of Tehuantepec, from 2000 to 2007. For this, fishery catches information was obtained from the artisanal fleet, at six landing sites in the Gulf, and the sex ratio, fork length (FL) and the catch per unit effort (CPUE) were estimated. From all sampling sites, a total of 3 494 females, and 3 877 males were obtained, and dolphinfish size as fork length (FL) ranged from 20.5 to 152cm. Fish size ranged from 25.5 to 148cm furcal length (FL) in males, and 20.5 to 129cm FL in females. The sex ratio (males:females) was 1:1, except in April-May (1:1.5, p < 0.05) and November (1:0.5, p < 0.05). The sex ratio at different size classes showed a significant bias towards females at smaller sizes (< 75cm FL), whereas the males were predominant in larger size classes (> 100cm FL). The size structure was bimodal, with a variation in the size average; the modes were defined as the small group (FL = 50-55cm) and the large size group (FL = 100-110cm). The CPUE showed seasonal changes: values were high for the November-December period, and values were lower for July-August. The seasonal and inter annual variation in the abundance of dolphinfish is probably related to a pre

  17. Liver transcriptome characterization of the endangered freshwater silverside Basilichthys microlepidotus (Teleostei: Atherinopsidae) using next generation sequencing.

    PubMed

    Vega-Retter, Caren; Véliz, David

    2014-10-25

    Twenty eight out of 44 Chilean freshwater fishes have been considered to fall within the vulnerable or threatened category. Thus, information about the biology, ecology and the effects of the anthropic activity on these species is fundamental to take appropriate conservation measures. In Chile the endemic silverside Basilichthys microlepidotus inhabits mainly rivers surrounded by cities; during the last 10years it was categorized as an endangered species, thus more basic information is needed in order to elaborate a plan of protection for this species. To this end, the transcriptome of B. microlepidotus was sequenced, assembled and characterized. A total of 7.8 million reads (1.05Gb) were obtained from the sequencing and 5.93 million reads (0.83Gb) were used for the de novo assembly, obtaining a total of 31,523 contigs. Of these, 13,724 contigs with expression in all the individuals used were retained for the functional annotation. 7938 sequences were successfully annotated; the biological processes class was the most highly represented, followed by molecular function and cellular component. These sequence data provide a useful new molecular resource for future studies on gene expression and the effects of the human activity on B. microlepidotus, which will facilitate obtaining more information about that, as well as the developing of appropriate conservation strategies for this species.

  18. 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.

  19. 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.

  20. Effects of global warming on fish reproductive endocrine axis, with special emphasis in pejerrey Odontesthes bonariensis.

    PubMed

    Miranda, Leandro Andrés; Chalde, Tomás; Elisio, Mariano; Strüssmann, Carlos Augusto

    2013-10-01

    The ongoing of global warming trend has led to an increase in temperature of several water bodies. Reproduction in fish, compared with other physiological processes, only occurs in a bounded temperature range; therefore, small changes in water temperature could significantly affect this process. This review provides evidence that fish reproduction may be directly affected by further global warming and that abnormal high water temperature impairs the expression of important genes throughout the brain-pituitary-gonad axis. In all fishes studied, gonads seem to be the organ more readily damaged by heat treatments through the inhibition of the gene expression and subsequent synthesis of different gonadal steroidogenic enzymes. In view of the feedback role of sex steroids upon the synthesis and release of GnRH and GtHs in fish, it is possible that the inhibition observed at brain and pituitary levels in treated fish is consequence of the sharp decrease in plasma steroids levels. Results of in vitro studies on the inhibition of pejerrey gonad aromatase expression by high temperature corroborate that ovary functions are directly disrupted by high temperature independently of the brain-pituitary axis. For the reproductive responses obtained in laboratory fish studies, it is plausible to predict changes in the timing and magnitude of reproductive activity or even the total failure of spawning season may occur in warm years, reducing annual reproductive output and affecting future populations.

  1. The life cycle and geographical distribution of the monorchiid Proctotrema bartolii (Digenea) in the clam Darina solenoides from the Patagonian coast, Argentina.

    PubMed

    Gilardoni, C; Carballo, M C; Cremonte, F

    2013-12-01

    The life cycle of Proctotrema bartolii Carballo, Laurenti & Cremonte 2011 (Digenea: Monorchiidae) at Fracasso Beach (the type locality) (42°25'S, 64°07'W), Península Valdés, Argentina, was investigated. This digenean uses the clam Darina solenoides (Mactridae) as both the first and second intermediate hosts in the natural environment. The metacercariae were located mainly at the tip of the incurrent siphon, with an infection prevalence of 100%. Experimental infections in other macroinvertebrates, such as the clam Tellina petitiana and the polychaete Glycera americana, were successful, but these and other invertebrates are not naturally infected. Silversides Odontesthes smitti and Odontesthes nigricans (Pisces: Atherinopsidae) and the mullet Eleginops maclovinus (Eleginopidae) act as the definitive hosts of both experimentally and naturally obtained adults. Fish acquire infection by eating either the siphon or the entire clam. Proctotrema bartolii seems to be endemic to the Magellan Region and is distributed where its intermediate clam host is present, from the San José Gulf in Península Valdés to the southern tip of South America.

  2. Next generation sequencing yields the complete mitochondrial genome of the Endangered Chilean silverside Basilichthys microlepidotus (Jenyns, 1841) (Teleostei, Atherinopsidae), validated with RNA-seq.

    PubMed

    Véliz, David; Vega-Retter, Caren; Quezada-Romegialli, Claudio

    2016-01-01

    The complete sequence of the mitochondrial genome for the Chilean silverside Basilichthys microlepidotus is reported for the first time. The entire mitochondrial genome was 16,544 bp in length (GenBank accession no. KM245937); gene composition and arrangement was conformed to that reported for most fishes and contained the typical structure of 2 rRNAs, 13 protein-coding genes, 22 tRNAs and a non-coding region. The assembled mitogenome was validated against sequences of COI and Control Region previously sequenced in our lab, functional genes from RNA-Seq data for the same species and the mitogenome of two other atherinopsid species available in Genbank.

  3. 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.

  4. 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...

  5. Organochlorine contaminants in different tissues from Platichthys flesus (Pisces, Pleuronectidea).

    PubMed

    Baptista, Joana; Pato, Pedro; Duarte, Armando C; Pardal, Miguel A

    2013-11-01

    Polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) are organic contaminants that tend to accumulate in fish. Estuaries are exposed to high anthropogenic activities, therefore tending to accumulate more contaminants than the adjacent coastal waters. Platichthys flesus, a fish with high economic value, was analysed for PCBs and HCB along its different age groups, in liver, gills, gonads and muscle. Younger fishes were caught in the estuary, whereas older fishes were caught in the adjacent coastal waters and acquired at Figueira da Foz Regional Office of Docapesca-Portos e Lotas, SA. Both contaminants concentrations follow the pattern: liver>gills>muscle. Hepatosomatic index had the lowest values in younger fishes and the highest values in older fishes. Condition factor values remain stable with age. Younger fishes had higher PCBs concentrations than the older fishes. In opposition HCB was only detected in fish from 3+ to 5+ and its concentration tended to increase with age. Overall P. flesus is considered safe for human intake.

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

    USGS Publications Warehouse

    Courtenay, Walter R.; 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.

  7. Alcohol abuse in sickle cell disease: the Pisces Project.

    PubMed

    Levenson, James L; McClish, Donna K; Dahman, Bassam A; Penberthy, Lynne T; Bovbjerg, Viktor E; Aisiku, Imoigele P; Roseff, Susan D; Smith, Wally R

    2007-01-01

    Alcohol abuse is common in patients with chronic painful medical disorders, but it has not been studied in sickle cell disease (SCD). In a prospective cohort study of SCD adults, 31.4% were identified as abusing alcohol. There were no significant differences between alcohol abusers and nonabusers on demographics, biological variables, depression, anxiety, measures of crisis and noncrisis pain, or opioid use, but abusers reported more pain relief from opioids than nonabusers did. Alcohol abusers had fewer unscheduled clinic visits, emergency room visits, hospital days, and any health care utilization for SCD, but this was only significant for emergency room visits. Quality of life was similar between both groups, except that alcohol abusers unexpectedly had better overall physical summary scores. Alcohol abusers were more likely to report coping by ignoring pain, diverting attention, and using particular self-statements.

  8. [Larval development of Hypsophrys nicaraguensis (Pisces: Cichlidae) under laboratory conditions].

    PubMed

    Molina Arias, Alex

    2011-12-01

    The cichlid Hypsophrys nicaraguensis is a popular fish known as butterfly, and despite its widespread use as pets, little is known about its reproductive biology. In order to contribute to this knowledge, the study describes the relevant larval development characteristics, from adult and larval cultures in captivity. Every 12h, samples of larvae were collected and observed under the microscope for larval stage development, and every 24h morphometric measurements were taken. Observations showed that at 120h, some larvae had swimming activity and the pectoral fins development was visible; at 144h, the dorsal fin appear and all larvae started food intake; at 168h, the formation of anal fins begins, small rudiments of pelvic fins emerge, the separation of caudal fin from anal and dorsal fins starts, and the yolk sac is reabsorbed almost completely; at 288h, the pelvic fins starts to form; at 432h, the rays and spines of dorsal and anal fins can be distinguished, both the anal and the dorsal fins have the same number of spines and rays as in adults. After 480h larvae have the first scales, ending the larval stages and starting the transformation to fingerlings. Larvae were successfully fed with commercial diet.

  9. PISCES field chemical emissions monitoring project: Site 112 emissions report

    SciTech Connect

    1995-12-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 112. Site 112 is a tangentially fired boiler firing residual oil. Site 112 employs electrostatic precipitators and a flue gas desulfurization system for particulate and SO{sub 2} control. Sampling at Site 112 was performed in July and August of 1992 for volatile organic compounds (VOCs) and mercury. The objective of this report is to transmit the detailed data to the U.S. Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts - as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites. An assessment of data from all plants that have been tested is presented in the Electric Utility Trace Substances Synthesis Report (EPRI TR-104614).

  10. Pisces field chemical emissions monitoring project: Site 117 emissions report

    SciTech Connect

    1995-12-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 117. Site 117 is a 1 MW selective catalytic reduction (SCR) pilot plant. The host boiler is an 850 MW boiler which burned a residual fuel oil. The objective of this report is to transmit the detailed data to the U.S. Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts - as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites. An assessment of data from all plants that have been tested is presented in the Electric Utility Trace Substances Synthesis Report.

  11. Effects of short periods of warm water fluctuations on reproductive endocrine axis of the pejerrey (Odontesthes bonariensis) spawning.

    PubMed

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

    2012-09-01

    The aim of this study was to assess fluctuations in daily water temperature in Chascomús Lagoon during one year, and to evaluate whether the highest temperature recorded during pejerrey spawning season can produce an endocrine disruption on brain-pituitary-gonads axis. Fish were subjected to daily temperature fluctuations: 17 °C to 19 °C (reproductive control), 19 °C to 25 °C, and 19 °C to 27 °C. After 8 days, ten fish per treatment were sacrificed and gene expression of gonadotropin-releasing hormone (GnRH-I, GnRH-II, GnRH-III), gonadotropin subunits-β (FSH-β, LH-β), glycoprotein hormone-α (GPH-α), gonadotropin receptors (FSH-R, LH-R), and gonadal aromatase (cyp19a1a) was analyzed. Also, plasma levels of sexual steroids and gonadal reproductive status were studied. Fish exposed to high temperature fluctuations quit spawning, presenting clear signs of gonadal regression. Fish recovered its spawning activity 11 weeks after heat treatment. At endocrine level, GnRH-I and FSH-β in both sexes, LH-β and GPH-α in males and FSH-R, LH-R and cyp19a1a in females decreased significantly in treated fish. Also, a strong reduction in plasma sex steroid levels was found for both sexes. This study demonstrated that pulses of warm water in natural environment during pejerrey spawning season can disrupt all levels of the reproductive axis, impairing reproduction.

  12. 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.

  13. 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).

  14. 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.

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

    PubMed

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

    2015-01-01

    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.

  16. 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.

  17. Early Osteological Development of Larvae and Juveniles in Red Spotted Grouper, Epinephelus akaara (Pisces: Serranidae)

    PubMed Central

    Park, Jong Youn; Han, Kyeong Ho; Cho, Jae Kwon; Myeong, Jeong In; Park, Jae Min

    2016-01-01

    We observed the osteological development of larval and juvenile red spotted grouper (Epinephelus akaara) in order to generate data for the assessment of skeletal deformities and to inform phylogenetic systematics research. Larvae and juveniles were obtained from a aquafarm in Muan-gun, Jeolla-namdo Province, Korea. The average water temperature at the time of breeding was 23.0°C and average water salinity was 33.0 psu. Freshly hatched fish larvae had not undergone any ossification, but ossification of the parasphenoid bone, which forms the base of the cranium, occurred as the juveniles reached an average body length (BL) of 2.49 mm. At the same time, ossification of the preopercle and opercle occurred in the operculum, and ossification of the maxilla, which forms the upper jaw, and the dentary bones, which form the lower jaw, began. In addition, ossification of the vertebra occurred by formation of 7 vertebral centra and the neural spine in the abdominal vertebra. When the juveniles reached an average (BL) of 5.22 mm, ossification of the nasal, lateral ethmoid, and alisphenoid bones occurred in the cranium; ossification of the endopterygoid and metapterygoid bones began in the palatine region; and ossification of the hypohyal and interhyal bones occurred in the hyoid arch. At an average (BL) of 20.9 mm, ossification of the basisphenoid bone in the cranium and the suborbital bone in the orbital region occurred. Ossification of the vertebra then occurred by the formation of long pairs of ribs from the third to the ninth abdominal vertebrae, completing osteological development. PMID:27660824

  18. 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.

  19. 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.

  20. 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.

  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. 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.

  3. Growth, feeding and reproduction of the catfish Eremophilus mutisii (Pisces: Trichomycteridae), from artificial reservoirs in Colombia.

    PubMed

    Pinilla, Gabriel; Abril, Maritza; González, Esperanza

    2006-06-01

    The catfish, Eremophilus mutisii, was cultured under different densities in artificial rainfall reservoirs at Caldas, Boyacá, Colombia. At capture, the average total length of the animals was 10 cm and the weight ranged between 9 and 10 g. These fish were in initial stages of sexual development. After a year in the reservoirs, they had increased in length and weight as follows (densities in parentheses): 5.22 cm and 27.23 g (0.5 individuals/m2); 1.98 cm and 8.79 g (1 individual/m2), and 2.45 cm and 0.82 g (2 individuals/m2). They were at the early stages of sexual maturity, and their condition factor fluctuated between 0.61 and 0.96. They preferably ingested insect larvae that were found in benthic and littoral communities of the reservoirs. The benthos was dominated by ephippia of Daphnia, lumbriculids, and chironomid larvae. The biomass of benthic organisms ranged between 0.1126 and 1.3847 g/m2. In the littoral community aquatic insects were the most important component, especially the hemipterans. The biomass of the littoral fauna ranged between 0.14 and 4.05 g/m2.

  4. Comparative life histories of fishes in the subgenus Limia (Pisces: Poeciliidae).

    PubMed

    Cohen, S N; Regus, J U; Reynoso, Y; Mastro, T; Reznick, D N

    2015-07-01

    This study presents life-history descriptions for 12 species in the subgenus Limia, which are endemic to the Greater Antilles. All species in this study lack evidence of superfoetation, producing a single brood of offspring before developing subsequent broods. Interbrood intervals (number of days between parturition events) are also consistent with intervals of species that lack superfoetation. Maternal provisioning, characterized by matrotrophy index, is <1.0 for all species of Limia. This is consistent with species that provide little or no maternal provisioning to developing embryos after ovum fertilization (lecithotrophic). Four species exhibit potentially bi-modal size distributions of mature males. Work on other poeciliids suggests that such bimodal distributions can be caused by genetic polymorphisms in some species. Principle component analyses revealed an axis of interspecific variation in life histories that separated species with small size at maturity and the production of many, small offspring from those with large size at maturity and that produce few, large offspring. This pattern of life-history diversity occurs in many other groups of organisms.

  5. Comparative life histories of fishes in the genus Phallichthys (Pisces: Poeciliidae).

    PubMed

    Regus, J U; Johnson, J B; Webb, S A; Reznick, D N

    2013-07-01

    This study presents a description of the life histories of all four species of the genus Phallichthys, found primarily in the Atlantic slope of Central America (ranging from northern Panama to Mexico), based on a combination of data collected from preserved and living specimens. All species produced a single litter of offspring before developing another brood (i.e. no superfoetation). In the laboratory, the mean time interval between successive litters ranged from 24 to 48 days, further suggesting that they lack superfoetation. Embryos lose from 15 to 65% of their dry mass during development, meaning all or the large majority of resources required for development are provided prior to fertilization (lecithotrophy). All mature male size distributions were platykurtotic and appeared either bimodal or multimodal. Multimodal and skewed size distributions have been associated with genetic polymorphisms for size at maturity in other species of Poeciliidae. As the sister clade to Phallichthys includes genera in which all species have superfoetation (Neoheterandria and Poeciliopsis), these results suggest that their common ancestor with Phallichthys also had superfoetation and that the trait has been lost.

  6. Arterioles in the swimming muscles of the leatherjacket Parika scaber (Pisces: Balistidae).

    PubMed

    Davison, W

    1987-06-01

    The leatherjacket (Parika scaber) is a balistiform fish which swims using its dorsal and anal median fins. The muscles controlling these fins are well vascularised, with control of blood flow effected by arterioles. These arterioles are long with a single layer of smooth muscle surrounding the endothelium, although the amount of contractile material is sparse, probably a consequence of the low blood pressure. The endothelial cells contain microfilaments, probably contractile, running along the length of the arteriole. The function of this material is unknown.

  7. [Culture of Poecilia reticulata (Pisces: Poecilidae) in tropical water bodies, Veracruz, México].

    PubMed

    Murillo, Patricia Devezé; Mendiola, Juan Lorenzo Reta; Sánchez Luna, Basilio

    2004-12-01

    Poecilia reticulata, also known as guppy, is the most popular fish in the aquarium environment. Guppys are viviparous fish with high tolerance to extreme temperatures. The development of the offspring takes between 25 and 30 days. We developed a technology for raising guppys, which outlines infrastructure and devices for reproduction, nursery, feeding, and commercialization, evaluating the financial and technical feasibility of this technology in a case study. The complete reproductive cycle occured in floating cages with 1 mm mesh and the method was tested in a tropical lagoon in Mexico. Water quality was monitored throughout the study period (temperature, dissolved oxygen and pH levels). A marketing survey was carried out at all existing aquarium shops in Veracruz City. Data collected depict quantities demanded and offered for each species by season, place of origin, and resistance to handling. The hydrobiological characteristics were: average temperature 31.4 degrees C, dissolved oxygen 4.5 mgl(-1), and pH level 6.8. With these values we built a production function, and used it to evaluate profitability. We estimate a benefit/cost ratio of 1.16, with a net annual income of US$257.67. The system may provide two permanent jobs.

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

    PubMed

    Bustamante, Carlos; 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.

  9. Near-infrared observations of galaxies in Pisces-Perseus. V. On the origin of bulges

    NASA Astrophysics Data System (ADS)

    Hunt, L. K.; Pierini, D.; Giovanardi, C.

    2004-02-01

    We investigate the scaling relations of bulge and disk structural parameters for a sample of 108 disk galaxies. Structural parameters of individual galaxies are obtained from two-dimensional bulge/disk decomposition of their H-band surface brightness distributions. Bulges are modelled with a generalized exponential (Sérsic) with variable integer shape index n. We find that bulge effective scalelengths reB and luminosity MB increase with increasing n, but disk properties are independent of bulge shape. As Hubble type T increases, bulges become less luminous and their mean effective surface brightness <μeB> gets fainter; disk <μeD> shows a similar, but much weaker, trend. When bulge parameters (<μeB>, reB, MB) are compared with disk ones (<μeD>, reD, MD), they are tightly correlated for n=1 bulges. The correlations gradually worsen with increasing n such that n=4 bulges appear virtually independent of their disks. The Kormendy relation, <μeB> vs. reB, is shown to depend on bulge shape n; the two parameters are tightly correlated in n=4 bulges (r=0.8), and increasingly less so as n decreases; disk <μeD> and reD are well correlated (r=0.7). Bulge-to-disk size ratios reB/reD are independent of Hubble type, but smaller for exponential bulges; the mean reB/reD for n=1 bulges is 4 times smaller than that for n=4, with a spread which is 9 times smaller. Strongly barred SB galaxies with exponential bulges are more luminous than their unbarred counterparts. Exponential bulges appear to be closely related to their underlying disks, while bulges with higher n values are less so; n=4 bulges and their disks apparently have no relation. We interpret our results as being most consistent with a secular evolutionary scenario, in which dissipative processes in the disk are responsible for building up the bulges in most spirals. Based on observations at the TIRGO, NOT, and VATT telescopes. TIRGO (Gornergrat, CH) is operated by IRA-CNR, Arcetri, Firenze. NOT (La Palma, Canary Islands) is operated by NOTSA, the Nordic Observatory Scientific Association. VATT (Mt. Graham, AZ) is operated by VORG, the Vatican Observatory Research Group. Full Table 1 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/414/905.

  10. A new species of Saurida (Pisces: Synodontidae) from the Mascarene Plateau, Western Indian Ocean.

    PubMed

    Russell, Barry C

    2015-04-16

    A new species of lizardfish, Saurida tweddlei n.sp., from the Mascarene Plateau, Western Indian Ocean, is described and figured. The new species is characterised by the following combination of characters: dorsal fin with 12-13 rays; pectorals with 14-15 rays; lateral-line scales 53-55; transverse scale rows above lateral line 4½, below lateral line 5½; pectoral fins moderately long (extending to or just beyond a line from origin of pelvic fins to origin of dorsal fin); 2 rows of teeth on outer palatines; 0-3 teeth on vomer; tongue with about 4-5 rows of teeth posteriorly; caudal peduncle compressed (depth greater than width); stomach and intestine pale whitish. A key to the species of Saurida of the Western Indian Ocean is provided.

  11. 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

  12. [Larval development of some Bregmaceros species (Pisces: Bregmacerotidae) from the southeast Gulf of Mexico].

    PubMed

    Blas-Cabrera, Jorge; Sánchez-Ramírez, Marina; Ocaña-Luna, Alberto

    2006-06-01

    We redescribe the larval development of Bregmaceros cantori based on 925 specimens ranging from 1.1 to 20.2 mm in standard length (SL), and describe the larvae of B. atlanticus (27 larvae, 1.7-7.5 mm), B. houdei (six, 1.5-1.9 mm) and B. macclellandi (three, 2.4, 3.4 and 5.4 mm). All specimens were collected in the southern Gulf of Mexico from November 27 through December 6, 1998. Larvae were identified to species, and descriptions were made based on pigmentation, and morphometric and meristic characteristics. We defined five development stages: preflexion, flexion, postflexion, transformation and juvenile. In the preflexion stage B. cantori displayed a greater growth in mouth size and head length relative to SL (positive allometry); there was negative allometry from the flexion to juvenile stage. B. cantori have the shortest body height and head length, thus being the thinnest; whereas B. macclellandi larvae are the most robust ones. From the four species reported from the southern Gulf of Mexico, B. atlanticus larvae are the most pigmented in both head and body, with an homogeneous pattern; B. macclellandi presents a different pigmentation pattern consisting in large melanophore groups with a body arrangement that changes from one stage to the next; additionally, from the preflexion stage it develops both the occipital radius and pelvic fins. B. houdei larvae measuring 1.5 to 1.9 mm have melanophores at the tip of the lower jaw and the head, as well as at the pectoral fin base. Larval development was more pronounced in this B. cantori and B. atlanticus than in specimens from higher latitudes.

  13. 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.

  14. Microstructure of pharyngeal tooth enameloid in the parrotfish Scarus rivulatus (Pisces: Scaridae).

    PubMed

    Carr, A; Kemp, A; Tibbetts, I; Truss, R; Drennan, J

    2006-01-01

    The microstructure of parrotfish pharyngeal teeth was examined using scanning electron microscopy to infer possible mechanical properties of the dentition with respect to their function. Parrotfish tooth enameloid is formed from fluorapatite crystals grouped into bundles. In the upper and lower pharyngeal jaw, the majority of the crystal bundles are orientated either perpendicularly or vertically to the enameloid surface. The only exception is in the trailing apical enameloid in which the majority of bundles are orientated perpendicularly or horizontally to the trailing surface. A distinct transition occurs through the middle of the apex between the leading and trailing enameloid in teeth of the lower pharyngeal jaw. This transition appears less distinct in the teeth of the upper pharyngeal jaw. Enameloid microstructure indicates that shear forces predominate at the apex of the teeth. In the remainder of the enameloid, the microstructure indicates that wear is predominant, and the shear forces are of less importance.

  15. Plate tectonics and biogeographical patterns of the Pseudophoxinus (Pisces: Cypriniformes) species complex of central Anatolia, Turkey.

    PubMed

    Hrbek, Tomas; Stölting, Kai N; Bardakci, Fevzi; Küçük, Fahrettin; Wildekamp, Rudolf H; Meyer, Axel

    2004-07-01

    We investigated the phylogenetic relationships of Pseudophoxinus (Cyprinidae: Leuciscinae) species from central Anatolia, Turkey to test the hypothesis of geographic speciation driven by early Pliocene orogenic events. We analyzed 1141 aligned base pairs of the complete cytochrome b mitochondrial gene. Phylogenetic relationships reconstructed by maximum likelihood, Bayesian likelihood, and maximum parsimony methods are identical, and generally well supported. Species and clades are restricted to geologically well-defined units, and are deeply divergent from each other. The basal diversification of central Anatolian Pseudophoxinus is estimated to have occurred approximately 15 million years ago. Our results are in agreement with a previous study of the Anatolian fish genus Aphanius that also shows a diversification pattern driven by the Pliocene orogenic events. The distribution of clades of Aphanius and Pseudophoxinus overlap, and areas of distribution comprise the same geological units. The geological history of Anatolia is likely to have had a major impact on the diversification history of many taxa occupying central Anatolia; many of these taxa are likely to be still unrecognized as distinct.

  16. 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.

  17. [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.

  18. 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...

  19. 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

  20. 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

  1. PISCES field chemical emissions monitoring project: Site 119 emissions report. Final report

    SciTech Connect

    1995-12-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 119. Site 119 is a residual oil-fired boiler, with an electrostatic precipitator for particulate control. Site 119 employs close-coupled overfire air and burner modifications for NO{sub x} control. The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts--as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites. An assessment of data from all plants that have been tested is presented in the Electric Utility Trace Substances Synthesis Report (EPRI TR-104614).

  2. PISCES field chemical emissions monitoring project: Site 12 emissions report. Final report

    SciTech Connect

    1995-10-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 12. Site 12 is a large, pulverized coal-fired power plant that burns a medium-sulfur bituminous coal. Site 12 employs electrostatic precipitators and a flue gas desulfurization system for particulate and S02 control. Testing at Site 12 was performed in the summer of 1990, with additional retests in August and December of 1992 for volatile organic compounds (VOCs) and mercury, respectively. Sampling and analytical problems during the initial test period necessitated the retests. The objective of this report is to transmit the detailed data to the U.S. Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts-as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites. An assessment of data from all plants that have been tested is presented in the Electric Utility Trace Substances Synthesis Report (EPRI TR-104614).

  3. PISCES field chemical emissions monitoring project: Site 19 emissions report. Final report

    SciTech Connect

    1995-12-01

    This report is one of a series sponsored by the Electric Power Research institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 19. Site 19 is a pulverized coal-fired boiler burning a medium-sulfur bituminous coal. Site 19 employs electrostatic precipitators for particulate control. The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts--as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites. An assessment of data from all plants that have been tested is presented in the Electric Utility Trace Substances Synthesis Report (EPRI TR-104614).

  4. PISCES field chemical emissions monitoring project: Site 102 emissions report. Final report

    SciTech Connect

    1995-12-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 102. Site 102 is a cyclone boiler burning a sub-bituminous coal. Site 102 employs an electrostatic precipitator for particulate control. The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts--as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites. An assessment of data from all plants that have been tested is presented in the Electric Utility Trace Substances Synthesis Report (EPRI TR-104614).

  5. PISCES field chemical emissions monitoring project: Site 118 emissions report. Final report

    SciTech Connect

    1995-12-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 118. Site 118 is a residual oil-fired boiler, with an electrostatic precipitator for particulate control. The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts--as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites. An assessment of data from all plants that have been tested is presented in the Electric Utility Trace Substances Synthesis Report (EPRI TR-104614).

  6. 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…

  7. The effects of temperature and busulfan (Myleran) on the yellowtail tetra Astyanax altiparanae (Pisces, Characiformes) spermatogenesis.

    PubMed

    de Siqueira-Silva, Diógenes Henrique; Silva, Amanda Pereira dos Santos; Ninhaus-Silveira, Alexandre; Veríssimo-Silveira, Rosicleire

    2015-10-01

    We aimed to standardize a protocol to suppress spermatogenesis in the characiform fish, Astyanax altiparanae, for future use as a host in germ cell transplant research, opening opportunities for a range of studies, such as spermatogenesis analyses and transgenesis because this species presents livestock characteristics to be used as a biological model. The effects of the chemotherapeutic busulfan (formulated as Myleran), which is used as medicine, therefore not as toxic to humans manipulation as analytical grade busulfan (Fluka) used in previous studies, were evaluated at physiological temperature of 28 °C, ideal for growth and reproduction of A altiparanae, and also at increased temperature 35 °C. The temperature groups were divided into three treatment groups: busulfan, DMSO only, and an untreated control. Macroscopic, histologic, stereological, and ultrastructure analysis showed that, at 28 °C, busulfan did not cause depletion of germ cells in A altiparanae. However, at 35 °C, sterilization was observed 3 weeks after the initial application. Similar results were obtained with maintenance of fish at 35 °C for a longer period with no accompanying Myleran treatment. This procedure allows reduction in stress and lower mortality resulting from manipulation during busulfan injection and is also suitable for mass treatment because large numbers of fish can be incubated in warm water.

  8. 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

  9. PISCES field chemical emissions monitoring project: Site 101 emissions report. Final report

    SciTech Connect

    1995-12-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 101. Site 101 is a pulverized coal-fired boiler burning a sub-bituminous coal. Site 101 employs a reverse-gas fabric filter for particulate control and a wet limestone flue gas desulfurization system for SO{sub 2} control. The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts-as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites.

  10. Tapeworms (Cestoda: Caryophyllidea), parasites of Clarias batrachus (Pisces: Siluriformes) in the Indomalayan region.

    PubMed

    Ash, Anirban; Scholz, Tomáš; Oros, Mikuláš; Kar, Pradip Kumar

    2011-06-01

    Revision of monozoic cestodes (Caryophyllidea) parasitic in commercially important walking catfish Clarias batrachus (L.) in tropical Asia (Indomalayan zoogeographical region) was carried out, based on the evaluation of newly collected material from India, Indonesia, and Thailand, as well as a study of type specimens. Instead of the 59 nominal taxa of 15 genera from 3 caryophyllidean families previously described, only 8 species of the Lytocestidae are considered to be valid: Bovienia indica (Niyogi, Gupta and Agarwal, 1982) n. comb.; Bovienia raipurensis (Satpute and Agarwal, 1980) Mackiewicz, 1994; Bovienia serialis (Bovien, 1926) Fuhrmann, 1931; Djombangia penetrans Bovien, 1926; Lucknowia microcephala (Bovien, 1926) n. comb.; Lytocestus indicus (Moghe, 1925) Woodland 1926; Pseudocaryophyllaeus ritai Gupta and Singh, 1983; and Pseudocaryophyllaeus tenuicollis (Bovien, 1926) n. comb. All valid species are redescribed and SEM photomicrographs of their scolices and photomicrographs of their eggs are provided for the first time. Crescentovitus Murhar, 1963, Heeradevina Srivastav and Khare, 2005, Pseudobatrachus Pathak and Srivastav, 2005, Pseudobilobulata Srivastav and Lohia, 2002, Pseudoclariasis Pathak, 2002, and Pseudoinverta Pathak, 2002 are invalidated and 50 nominal species are newly synonymized, including 4 species described from other fish hosts. Taxonomic status of the remaining caryophyllidean taxa reported from C. batrachus (at least 6 taxa) could not be clarified because of the unavailability of their original descriptions. A key to identification of caryophyllidean tapeworms parasitic in C. batrachus is provided. To avoid current inflation of descriptions of invalid taxa, researchers are strongly encouraged to work only with well-fixed material; damaged, decomposed, or strongly flattened specimens should not be used for taxonomic studies, and type specimens must always be deposited in internationally recognized collections.

  11. PISCES field chemical emissions monitoring project: Site 13 emissions report. Final report

    SciTech Connect

    1995-11-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 13. Site 13 consists of a boiler burning No. 6 fuel oil. No air pollution control equipment was available to control emissions from the boiler; however, a pilot-scale pulse-jet fabric filter treating a small fraction of the flue gas from this unit was also tested. The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts--as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites. An assessment of data from all plants that have been tested is presented in the Electric Utility Trace Substances Synthesis Report (EPRI TR-104614).

  12. PISCES Field Chemical Emissions Monitoring project: Site 15 emissions report. Final report

    SciTech Connect

    1995-11-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 15. Site 15 is a pulverized coal-fired boiler burning a medium-sulfur bituminous coal. Site 15 employs electrostatic precipitators for particulate control. The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts--as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites. An assessment of data from all plants that have been tested is presented in the Electric Utility Trace Substances Synthesis Report (EPRI TR-104614).

  13. PISCES Field Chemical Emissions Monitoring Project: Volume 1: Sites 103-105 emissions report

    SciTech Connect

    1995-12-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at seven electric utility plants in California-Sites 103 through 109. The sites tested consist of utility boilers sampled during both oil and natural gas-fired operation. None of the units were equipped with particulate control devices. The objective of this report is to transmit the detailed data to the U.S. Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts-as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites. An assessment of data from all plants that have been tested is presented in the Electric Utility Trace Substances Synthesis Report (EPRI TR-104614).

  14. PISCES Field Chemical Emissions Monitoring Project: Site 18 emissions report. Final report

    SciTech Connect

    1995-11-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 18. Site 18 is a pulverized coal-fired boiler burning a medium-sulfur bituminous coal. Site 18 employs electrostatic precipitators for particulate control. During the sampling project, a pilot pulse-jet fabric filter treated a small fraction of the flue gas downstream of the ESP. Measurements were also conducted around the pilot fabric filter. The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts -- as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites. An assessment of data from all plants that have been tested is presented in the Electric Utility Trace Substances Synthesis Report (EPRI TR-104614).

  15. PISCES field chemical emissions monitoring project: Site 11 emissions report. Final report

    SciTech Connect

    1995-12-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 11. Site 11 is a large, pulverized coal-fired power plant that burns a low-sulfur sub-bituminous coal. Site 11 employs electrostatic precipitators and a flue gas desulfurization system for particulate and SO{sub 2} control. Testing at Site 11 was performed in the summer of 1990, with additional retests in August 1992 and April 1993 for volatile organic compounds (VOCs) and mercury, respectively. Sampling and analytical problems during the initial test period necessitated the retests. The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts--as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites. An assessment of data from all plants that have been tested is presented in the Electric Utility Trace Substances Synthesis Report (EPRI TR-104614).

  16. PISCES field chemical emissions monitoring project: Site 14 emissions report. Final report

    SciTech Connect

    1995-11-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 14. Site 14 is a pilot-scale dry flue gas desulfurization (FGD) system consisting of a spray dryer and fabric filter. The flue gas for the pilot unit is provided by an adjacent power plant boiler which bums a medium-sulfur bituminous coal. The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency m evaluating utility trace chemical emissions as well as the associated health risk impacts-as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites.

  17. PISCES field chemical emissions monitoring project: Site 116 emissions report. Final report

    SciTech Connect

    1995-12-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 116. Site 116 consists of a pulverized coal-fired boiler burning a bituminous coal, with an electrostatic precipitator for particulate control. Site 116 also included s a Babcock & Wilcox`s DOE Clean Coal Technology Program`s 5{minus}MWe SO{sub x}{minus}NO{sub x}-Rox Box {trademark} (SNRB{trademark}) Field Demonstration. The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts-as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites.

  18. PISCES field chemical emissions monitoring project: Site 22 emissions report. Final report

    SciTech Connect

    1995-12-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 22. Site 22 is a large, pulverized coal-fired boiler burning a low-sulfur sub-bituminous coal. Site 22 employs electrostatic precipitators for particulate control. The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts-as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites.

  19. PISCES field chemical emissions monitoring project: Site 16 emissions report. Final report

    SciTech Connect

    1995-11-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 16. Site 16 is a pulverized coal-fired boiler burning a medium-sulfur bituminous coal. Site 16 employs electrostatic precipitators for particulate control. Measurements were conducted under two modifications: overfire air and a combination of overfire air with low-NO{sub x} burners. The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts -- as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites.

  20. PISCES Field Chemical Emissions Monitoring project: Site 10 emissions report. Final report

    SciTech Connect

    1995-11-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions at Site 10. Site 10 is a fluidized bed combustor that burns a low-sulfur sub-bituminous coal. Site l0 is a fluidized bed combustor that burns a low-sulfur sub-bituminous coal. Site 10 employs a fabric filter for particulate control. Limestone is fed into the fluidized bed for SO{sub 2} control. Testing at Site 10 was performed in the summer of 1990, with addition retests conducted for volatile organic compounds (VOCs). The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts--as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites. An assessment of data from all plants that have been tested is presented in the Electric Utility Trace Substances Synthesis Report (EPRI TR-104614).

  1. PISCES field chemical emissions monitoring project: Site 20 emissions report. Final report

    SciTech Connect

    1995-12-01

    This report is one of a series sponsored by the Electric Power Research Institute in the area of trace substance emissions from fossil-fuel power Plants. This report presents the results of a sampling and analytical study to characterize trace substances emissions at Site 20. Site 20 is a pulverized coal-fired boiler burning a medium-sulfur bituminous coal. Site 20 is a large, pulverized coal-fired power plant that bums a lignite coal. Site 20 employs electrostatic precipitators and a flue gas desulfurization system for particulate and SO{sub 2} control. The objective of this report is to transmit the detailed data to the US Environmental Protection Agency (EPA) to assist the Agency in evaluating utility trace chemical emissions as well as the associated health risk impacts-as mandated in Title III of the 1990 Clean Air Act Amendments. This report does not attempt to compare the results with other sites.

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

    PubMed

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

    2015-05-13

    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.

  3. 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

  4. 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

  5. Characterization of MboI satellites in Cirrhina mrigala and Clarias batrachus (Pisces).

    PubMed

    Padhi, B K; Ghosh, S K; Mandal, R K

    1998-02-01

    We have cloned and characterized two highly reiterated, tandemly repeated, and A+T rich MboI DNA fragments, one in Cirrhina mrigala (Cyprinidae), with a monomer size of 266 bp, and one in Clarias batrachus (Clariidae), with a monomer size of 227 bp. The MboI fragment in C. mrigala is species-specific and absent in other carps, such as Catla catla and Labeo rohita. The MboI fragment in C. batrachus was also present in two other catfishes tested, namely Clarias gariepinus and Heteropneustes fossilis. In C, mrigala x C. catla and C. mrigala x L. rohita hybrids, the C. mrigala specific MboI fragment is inherited uniparentally. In the reciprocal hybrids of C. batrachus x H. fossilis, the satellite ladder contains the bands of both parental species. The MboI satellite of carp may be useful in genetic introgression analysis and that of catfish in distinguishing between gynogenetic progeny and true hybrids.

  6. Effect of body size and temperature on respiration of Galaxias maculatus (Pisces: Galaxiidae)

    USGS Publications Warehouse

    Milano, D.; Vigliano, P.H.; Beauchamp, David A.

    2016-01-01

    Body mass and temperature are primary determinants of metabolic rate in ectothermic animals. Oxygen consumption of post-larval Galaxias maculatus was measured in respirometry trials under different temperatures (5–21°C) and varying body masses (0.1–>1.5 g) spanning a relevant range of thermal conditions and sizes. Specific respiration rates (R in g O2 g−1 d−1) declined as a power function of body mass and increased exponentially with temperature and was expressed as: R = 0.0007 * W −0.31 * e 0.13 * T. The ability of this model to predict specific respiration rate was evaluated by comparing observed values with those predicted by the model. Our findings suggest that the respiration rate of G. maculatus is the result of multiple interactive processes (intrinsic and extrinsic factors) that modulate each other in ‘meta-mechanistic’ ways; this would help to explain the species’ ability to undergo the complex ontogenetic habitat shifts observed in the lakes of the Andean Patagonic range.

  7. [The System of the Suborder Zoarcoidei (Pisces, Perciformes) as Inferred from Molecular Genetic Data].

    PubMed

    Radchenko, O A

    2015-11-01

    Based on an analysis of sequence variation in mitochondrial and nuclear markers, the levels of divergence, relationships, and system of the suborder Zoarcoidei was defined. It was demonstrated that DNA lineages of the families Bathymasteridae and Cebidichthyidae were positioned at the bottom ofthe suborder phylogenetic tree. The family Zoarcidae is a monophyletic group, the youngest in the evolutionary terms. Zoarcidae, Anarhichadidae, Neozorcidae, and Eulophiidae form a group of related families. The family Stichaeidae is heterogeneous and has a polyphyletic origin; within this family, the subfamilies Chirolophinae, Alectgiinae, Xiphisterinae, and Stichaeinae are sister taxa. The subfamilies Opisthocentrinae and Lumpeninae are isolated from Stichaedae; Opisthocentrinae is closely associated with the families Pholidae and Ptilichthyidae, and Lumpeninae is closely associated with Zaproridae and Cryptacanthodidae. It is suggested that the rank of subfamilies Opisthocentrinae and Lumpeninae should be raised.

  8. Complete mitochondrial genome of the pink clownfish Amphiprion perideraion (Pisces: Perciformes, Pomacentridae).

    PubMed

    Hu, Xueyi; Li, Jianlong; Liu, Min

    2016-01-01

    In this study the complete mitochondrial (mt) genome of the pink clownfish Amphiprion perideraion was obtained by using eight consensus primer pairs with a long PCR technique. The circular mtDNA molecule was 16,579 bp in size and the overall nucleotide composition of the H-strand was 29.37% A, 25.50% T, 15.68% G and 29.45% C, with an A + T bias. The complete mitogenome contained 13 protein-coding genes, 2 rRNAs, 22 tRNAs and a control region, and the gene order was typical of vertebrate mitogenomes. The complete mitochondrial genome of A. perideraion is a representative of the subgenus Phalerebus for mitogenomes database of anemonefishes, which can be used to unveil taxonomic problems and phylogenetic relationships in Amphiprioninae.

  9. Epinephelus moara: a valid species of the family Epinephelidae (Pisces: Perciformes).

    PubMed

    Liu, M; Li, J-L; Ding, S-X; Liu, Z-Q

    2013-05-01

    This study documents the major external and internal morphological differences between Epinephelus bruneus and Epinephelus moara, and analyses the complete mitogenomes of both species. The partial cytochrome oxidase subunit I (coI) sequence divergence between E. bruneus and E. moara is significantly higher than specimens within the same species (P < 0·05). Analyses of gene flow (Nm = 0·02) and genetic differentiation (ϕst = 0·92995, P > 0·05) reveal reproductive isolation between E. bruneus and E. moara. These results support the hypothesis that E. moara is a valid species. Further molecular comparisons between E. bruneus and E. moara obtained in this study and a specimen identified in GenBank as E. bruneus from South Korea reveal that the latter is identical to E. moara rather than to E. bruneus.

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

    PubMed

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

    2016-07-26

    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.

  11. Reproduction and embryogenesis of the mandi-amarelo catfish, Pimelodus maculatus (Pisces, Pimelodidae), in captivity.

    PubMed

    Arantes, F P; Borçato, F L; Sato, Y; Rizzo, E; Bazzoli, N

    2013-02-01

    To study reproduction and embryogenesis, Pimelodus maculatus specimens were kept in captivity and captured bimonthly during 1 year. Gonads samples (211 specimens) were collected and submitted to routine histological techniques. Pimelodus maculatus prepared to reproduce when water temperature was high, and even reached advanced maturation but did not spawn in captivity. Spent fish gonads were not documented, and atretic follicles were frequent (60%) in late maturation females. When then submitted to hypophysation, 70% of the females responded positively to hormonal treatment. Oocyte extrusion occurred 8 h after a second hormonal injection at 26°C. The fertilisation rate was 65.1 ± 9.2% at 24°C. Recently spawned oocytes of P. maculatus were spherical, non-adhesive, yellow in colour, with an average diameter of 1113.92 ± 37.02 μm and covered by a thick gelatinous layer. Blastopore closure occurred 7 h and 30 min after fertilisation. Embryonic development was completed within 18 h after fertilisation. The results of this work provide important knowledge for the handling and cultivation of not only P. maculatus, but other species of potential value for fish culture.

  12. 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.

  13. Description of a new species of Microstoma (Pisces, Microstomatidae) from the southwestern Pacific Ocean.

    PubMed

    Gon, Ofer; Stewart, Andrew L

    2014-11-12

    A new species of the microstomatid genus Microstoma is described from specimens collected in the SW Pacific Ocean off New Zealand and Australia. Microstoma australis n. sp. differs from M. microsotma of the Mediterranean and Atlantic Ocean in having a higher number of gill rakers and vertebrae. Both species are compared with available data for NE Pacific specimens.

  14. Evaluation of genotoxicity and effects on reproduction of nonylphenol in Oreochromis niloticus (Pisces: Cichlidae).

    PubMed

    Rivero, Carla L G; Barbosa, Antônio C; Ferreira, Maria Fernanda N; Dorea, José G; Grisolia, Cesar K

    2008-11-01

    Nonylphenol ethoxylate (NPE) is widely used as a component of detergents, paints, pesticides, and many other products. In the aquatic environment NPE breakdown to 4-nonylphenol (NP), which is more stable and persistent. NP is estrogenic in fish, avian, and mammals and is described as an environmental pollutant with endocrine disruptor characteristics. The genotoxicity of NP was evaluated through micronuclei assay and single cell gel electrophoresis (Comet assay) in peripheral erythrocytes of Oreochromis niloticus exposed in vivo. The study on reproductive development was also carried out in male and female gonads of O. niloticus. Lethal concentration (LC 50%) of 0.032 ml l(-1) was previously determined. We ran assays with O. niloticus exposed to concentrations of 1.0, 10.0, and 16.0 microl l(-1) of NP diluted in water. Our results showed that NP was not genotoxic. However, 3-day exposure to NP in concentrations of 1.0, 10.0, and 16.0 microl l(-1) of water increased the frequency of reproductive stages in males and females. The histology of the reproductive tract of the treated fish was significantly altered in females treated with 16.0 microl l(-1) of water when compared to controls. Analogous estrogenic effects were observed, such as accelerated maturation of oocytes and spermatogenesis. These results showed that the O. niloticus reproductive system is sensitive to NP estrogenicity.

  15. In situ assessment of two catfish species (pisces, Ariidae) to evaluate pollution in a harbor

    NASA Astrophysics Data System (ADS)

    Neta, Raimunda Nonata Fortes Carvalho; Junior, Audalio Rebelo Torres; Sousa, Débora Batista Pinheiro; de Sousa de Oliveira Mota Andrade, Ticianne; Torres, Hetty Salvino; da Silva Castro, Jonatas; da Silva de Almeida, Zafira; Santos, Débora Martins Silva; Tchaicka, Lígia

    2016-12-01

    A histopathological and biometric database for the catfish Sciades herzbergii and Bagre bagre from São Luís Island (Harbor area) and Caranguejos Island (reference area) in Brazil is presented. Branchial and hepatic lesions were classified into three reaction patterns: 1) circulatory or inflammatory disturbances; 2) regressive changes; 3) progressive changes. The total length (Lt), standard length (Ls), furcal length (Lf), total weight (Wt), and gonad weight (Wg) of each fish were recorded. As expected, most populations of catfish considered in this study are highly heterogeneous, with lengths and weights deviating from the reference sample. No histopathological lesions were observed in Sciades herzbergii examined at the reference site (Caranguejos Island). In contrast, 90% of the catfish S. herzbergii from sites located in the Harbor Area (São Luís Island) had one or more types of branchial and hepatic lesions. As opposed to what was observed in S. herzbergii, more than 86.33% of Bagre bagre individuals showed histopathological alterations in both areas. The utility of histopathological lesions and biometric data as sensitive indicators of the health of wild catfish populations has been demonstrated. Sciades herzbergii proved to be a better species for biomonitoring because it was able to differentiate one impacted site (Port Area/ São Luís Island) from a region relatively free of contaminants (Reference Area/ Caranguejos Island).

  16. A mitochondrial DNA based phylogeny of weakfish species of the Cynoscion group (Pisces: Sciaenidae).

    PubMed

    Vergara-Chen, Carlos; Aguirre, Windsor E; González-Wangüemert, Mercedes; Bermingham, Eldredge

    2009-11-01

    We infer the phylogeny of fishes in the New World Cynoscion group (Cynoscion, Isopisthus, Macrodon, Atractoscion, Plagioscion) using 1603bp of DNA sequence data from three mitochondrial genes. With the exception of Plagioscion, whose position was ambiguous, the Cynoscion group is monophyletic. However, several genera examined are not monophyletic. Atlantic and Pacific species of Cynoscion are interspersed in the tree and geminate species pairs are identified. Intergeneric relationships in the group are clarified. Our analysis is the first comprehensive phylogeny for the Cynoscion group based on molecular data and provides a baseline for future comparative studies of this important group.

  17. Early Osteological Development of Larvae and Juveniles in Red Spotted Grouper, Epinephelus akaara (Pisces: Serranidae).

    PubMed

    Park, Jong Youn; Han, Kyeong Ho; Cho, Jae Kwon; Myeong, Jeong In; Park, Jae Min

    2016-06-01

    We observed the osteological development of larval and juvenile red spotted grouper (Epinephelus akaara) in order to generate data for the assessment of skeletal deformities and to inform phylogenetic systematics research. Larvae and juveniles were obtained from a aquafarm in Muan-gun, Jeolla-namdo Province, Korea. The average water temperature at the time of breeding was 23.0°C and average water salinity was 33.0 psu. Freshly hatched fish larvae had not undergone any ossification, but ossification of the parasphenoid bone, which forms the base of the cranium, occurred as the juveniles reached an average body length (BL) of 2.49 mm. At the same time, ossification of the preopercle and opercle occurred in the operculum, and ossification of the maxilla, which forms the upper jaw, and the dentary bones, which form the lower jaw, began. In addition, ossification of the vertebra occurred by formation of 7 vertebral centra and the neural spine in the abdominal vertebra. When the juveniles reached an average (BL) of 5.22 mm, ossification of the nasal, lateral ethmoid, and alisphenoid bones occurred in the cranium; ossification of the endopterygoid and metapterygoid bones began in the palatine region; and ossification of the hypohyal and interhyal bones occurred in the hyoid arch. At an average (BL) of 20.9 mm, ossification of the basisphenoid bone in the cranium and the suborbital bone in the orbital region occurred. Ossification of the vertebra then occurred by the formation of long pairs of ribs from the third to the ninth abdominal vertebrae, completing osteological development.

  18. Simulation of a Shot from the Otomelara 76/62 with Pisces-2delk Gain Burning (Simulatie van een schot van de Otomelara 76/62 met pisces-2delk Gain Burning).

    DTIC Science & Technology

    1992-09-01

    In dit geval is daar de covolume vergelijking (ook wel bekend als Noble-Abet vergelijk~ing) voor gebruikt. Deze subroutine hoeft niet gedeclareerd te...maximale theoretische druk 232.6 MPa force 915.2 Id/kg molaire massa kruitgassen 23.2 g/rnol covolume kruitgassen 1.065 cm3/g gamma (cd,/c) 1.258 soortelijke...gehouden worden met bet covolume van de kruitgassen, de onstekcing (beide bekend) en warmteverliezen naar de born. Van dit laatste kan een redelijke

  19. Effects of a Supraseasonal Drought on the Ecological Attributes of Plagioscion squamosissimus (Heckel, 1840) (Pisces, Sciaenidae) in a Brazilian Reservoir

    PubMed Central

    Souza, Antonia E. F.; Oliveira, Jônnata F.; Fernandes, Rodrigo; Costa, Rodrigo S.

    2017-01-01

    The aim of this study was to evaluate the effect of a supraseasonal drought on the ecological attributes of Plagioscion squamosissimus. The fish were caught quarterly from February 2010 to November 2014 using gill nets in the reservoir of Santa Cruz, Rio Grande do Norte, Brazil. The abundance of the species was evaluated with the catch per unit effort (CPUE) metric and then correlated with the accumulated rainfall and water volume of the reservoir. The diet of the fish was evaluated using the feeding index (IAi). The proportional similarity index (PSi) was used to evaluate the variation in the niches of the fish. The body condition was inferred through the relative condition factor, and its variation was assessed with ANOVA. A reduction in the abundance of the species that were positively correlated with the reservoir water volume was observed. The diet of the fish comprised shrimp, gastropods, fish, insects, shrimp larvae, and vegetable matter, with shrimp being the major component. PSi showed the occurrence of individual specialization during November 2013 and November 2014. The relative condition factor was not correlated with a reduction in the water volume of the reservoir. The supraseasonal drought did not affect the relative condition factor, diet, and the trophic niche, but it did affect the species abundance. PMID:28326431

  20. Pirimicarb-based formulation-induced genotoxicity and cytotoxicity in the freshwater fish Cnesterodon decemmaculatus (Jenyns, 1842) (Pisces, Poeciliidae).

    PubMed

    Vera-Candioti, Josefina; Soloneski, Sonia; Larramendy, Marcelo L

    2015-11-01

    We analyzed the aspects of lethality, genotoxicity, and cytotoxicity in the ten spotted live-bearer exposed under laboratory conditions to the pirimicarb-based formulation Patton Flow® (50% active ingredient (a.i.)). Acute effects were evaluated using different end points for lethality, genotoxicity, and cytotoxicity. Median lethal concentration (LC50) estimation was employed as a bioassay for lethality, whereas micronucleus (MN) induction and alterations in erythrocyte/erythroblast frequency were used as end points for genotoxicity and cytotoxicity, respectively. Results demonstrated an LC5096h value of 88 mg/L. Patton Flow® increased the MN frequency in fish erythrocytes after 48 h of exposure at a concentration of 66 mg/L, whereas a concentration range of 22-66 mg/L was able to exert the same genotoxic effect at 96 h of treatment. Furthermore, cytotoxicity was also observed by alterations in erythrocyte/erythroblast frequencies within the concentration range of 22-66 mg/L, regardless of the exposure time. Our current observations provide evidence that Patton Flow® (50% a.i.) should be considered a clear lethal, cytotoxic, and genotoxic agent on Cnesterodon decemmaculatus. Thus, repeated applications of this carbamic insecticide can enter the aquatic environment and exert deleterious effects on aquatic organisms other than the evaluated species C. decemmaculatus.

  1. Two new species of parasitic nematodes from the dogtooth tuna Gymnosarda unicolor (Pisces) off the Maldive Islands.

    PubMed

    Moravec, Frantisek; Lorber, Julia; Konecný, Robert

    2007-02-01

    Two new nematode species, Philometra gymnosardae n. sp. (Philometridae) and Heptochona maldivensis n. sp. (Rhabdochonidae), are described from the dogtooth tuna Gymnosarda unicolor (Rüppell) (Scombridae, Perciformes) from the Indian Ocean off the Maldive Islands (Republic of Maldives). The former species is characterized mainly by unequal, conspicuously long (859 and 435 microm) spicules; the structure of the caudal end in the male (found in the host's stomach); by markedly large, oval cephalic papillae (n = 8) of the outer circle; the presence of a small, anterior bulb on the very long esophagus; and 2 large caudal projections in the gravid female (parasitic in the host's body cavity). This is the first-known species of Philometra whose gravid females are present in the body cavity of tuna fishes. Heptochona maldivensis resembles H. stromatei but differs mainly in the position of deirids, shape of the muscular esophagus, character of postanal papillae, length of the left spicule (648 microm), much larger body measurements, location in the host (stomach), and the host type. Rhabdochona parastromatei Bilqees, 1971, is synonymized with H. stromatei, whereas Heptochona sindica Akram and Pie de Imprenta, 1988, and H. rivdica Akram, 1988, are invalid names. Heptochona varmai is transferred to another genus as Rhabdochona varmai (Gupta and Masoodi, 1990) n. comb. Rhabdochona varmai, Heptochona schmidtii Arya, 1991, and Rhabdochona marina Lakshmi and Sudha, 1999, are considered species inquirendae.

  2. Campechetrema herrerai n. gen., n. sp. (Trematoda: Cryptogonimidae) from the intestine of Petenia splendida (Pisces: Cichlidae) from Campeche, Mexico.

    PubMed

    Lamothe-Argumedo, R; Salgado-Maldonado, G; Pineda-López, R

    1997-02-01

    Campechetrema herrerai n. gen, n. sp. is described from the cichlid fish Petenia splendida from EI Vapor lagoon, an oligohaline lagoon, Campeche, México. It is distinguished from other genera of Cryptogoniminae by the presence of a single gonotyl, a preequatorial acetabulum, few vitelline follicles, and lack of pars prostatica and prepharynx.

  3. [Distribution, abundance and population parameters of Diapterus rhombeus (Pisces: Gerreidae) in Laguna de Términos, Campeche, Mexico].

    PubMed

    Ayala-Pérez, L A; Gómez-Montes, B A; Miranda, J R

    2001-06-01

    Diapterus rhombeus dominates the nektonic community of Terminos Lagoon and is associated to zones with submerged vegetation, temperatures between 27 and 33 degrees C and salinity between 25 and 36.5 UPS. A total of 3,024 individuals were collected with a trawl net in 23 sites between September 1997 and September 1998. The length-weight model parameters are a = 0.0098; b = 3.155 with a 96% correlation. The growth parameters are L infinity = 20.4 cm, k = 0.74 and t(o) = -4.207 and the total mortality coefficient is 3.526. Fish length is 2.5-18.0 cm with a mode of 7.5 cm. Recruitment is continuous with a peak from May to August. The species uses several habitats of the lagoon mainly for feeding and growth, reproduction probably occurs in the adjacent continental shelf. Movements between continental shelf and the estuarine system represent a continuous energy flow.

  4. 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

    2016-05-09

    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.

  5. A new species of highland loach, Schistura sirindhornae, from the upper Chao Phraya River basin, Thailand (Pisces: Ostariophysi: Nemacheilidae).

    PubMed

    Suvarnaraksha, Apinun

    2015-05-22

    Schistura sirindhornae, a new species of nemacheilid, is described from the Nan River basin in northern Thailand. It is distinguished from all other species of Schistura in having overlapping scales on the entire body similar to scales of balitorids, transparent scales on the belly and thorax, a lateral-line canal that is similar to that of most cyprinids and balitorids in being present across the entire lateral-line surface of the scale instead of being represented only by a pore. It also has a unique color pattern of irregular brown bars on the back and side of the faint yellow-orange body, a bright triangular orange mark on the occiput, an orange crown-shaped mark between the eyes, an uninterrupted black mark along the base of the dorsal fin, a crescent-shaped bar on the base of the caudal fin, and bright iridescent orange areas on the upper and lower extremities of the caudal-fin base. Schistura sirindhornae is known only from the upper Nan River drainage, Nan Province, Thailand.

  6. 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.

  7. 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.

  8. [First report in Panama on Nerocila californica Schioedte and Meinert 1881 (Isopoda: Cymothoidea) in Sciaenops ocellatus (L) (Pisces: Sciaenidae)].

    PubMed

    Garcés, H A

    1993-01-01

    One juvenile specimen of the isopod Nerocila californica (acuminata form) was found on the skin of a cage-raised red drum, Sciaenops ocellatus, in Aguadulce, Cocle Province. This finding is the first report of the occurrence of Nerocila californica as ectoparasitic of fishes on the Pacific side of the Republic of Panama.

  9. Evidence for historical introgression along a contact zone between two species of char (Pisces: Salmonidae) in northwestern North America.

    PubMed

    Redenbach, Z; Taylor, Eric B

    2002-05-01

    Phylogeographic analyses can yield valuable insights into the geographic and historical contexts of contact and hybridization between taxa. Two species of char (Salmonidae), Dolly Varden (Salvelinus malma) and bull trout (S. confluentus) have largely parapatric distributions in watersheds of northwestern North America. They are, however, sympatric in several localities and hybridization and some introgression occurs across a broad area of contact. We conducted a comparative phylogenetic analysis of Dolly Varden and bull trout to gain a historical perspective of hybridization between these species and to test for footprints of historical introgression. We resolved two major Dolly Varden mitochondrial DNA (mtDNA) clades (with 1.4-2.2% sequence divergence between haplotypes) that had different geographical distributions. Clade N is distributed across most of the range of Dolly Varden, from southern British Columbia through to the Kuril Islands in Asia. Clade S had a much more limited distribution, from Washington state, at the southern limit of the Dolly Varden range, to the middle of Vancouver Island. The distribution and inferred ages of the mtDNA clades suggested that Dolly Varden survived the Wisconsinan glaciation in a previously unsuspected refuge south of the ice sheet, and that Dolly Varden and bull trout were probably in continuous contact over most of the last 100,000 years. When bull trout were included in the phylogenetic analysis, however, the mtDNA of neither species was monophyletic: Clade S Dolly Varden clustered within the bull trout mtDNA clade. This pattern was discordant with two nuclear phylogenies produced (growth hormone 2 and rRNA internal transcribed sequence 1), in which Dolly Varden and bull trout were reciprocally monophyletic. This discordance between mtDNA- and nDNA-based phylogenies indicates that historical introgression of bull trout mtDNA into Dolly Varden occurred. Percent sequence divergence within these introgressed Dolly Varden (clade S) was 0.2-0.6%, implying that the introgression occurred prior to the most recent glaciation. Our analysis and other evidence of contact between divergent lineages in northwestern North America strongly suggests that the area may be the site of previously unsuspected suture zones of aquatic biotas.

  10. [Oropharyngeal morphology and food habits of Micropogonias furnieri (Pisces: Sciaenidae) in the North coast of Estado Sucre, Venezuela].

    PubMed

    Ruiz, L J; Prieto, A; Lemus, M

    2001-01-01

    Morphology of the mandibular and pharyngeal region, and the feeding habits of Micropogonias furnieri were examined in 256 male and female specimens, between 28.7 and 54.3 cm total length, collected around Morro Puerto Santo, in northeast Sucre State, Venezuela (10 degrees 45'00" N-63 degrees 8'0" W), from May 1989 to April 1990. Micropogonias furnieri has a small ventral mouth; protrusible premaxillary and dentary; first branchial arches with 21 to 27 gill rakers, generally 24 to 25; and 7 to 11 pyloric caecae. The index of vacuity was low, with mean value of 7.00%. The mean intestinal index was 0.72, indicative of carnivorous species. Analysis of frequency of occurrence, indicates preference for crustaceans (45.70%), mainly crabs (34.90%), followed by polychaetes (28.00%), fishes (11.41%) and occasionally mollusks and echinoderms (4.0 and 3.9%, respectively). The diet of this species did not vary with sex.

  11. Range expansion of the Mayan cichlid, cichlasoma urophthalmus (pisces, cichlidae), above 28°N in Florida

    USGS Publications Warehouse

    Paperno, R.; Ruiz-Carus, R.; Krebs, J.M.; McIvor, C.C.

    2008-01-01

    Introduced exotic species are a well-recognized problem in Florida's subtropical ecosystems. The presence of the exotic Mayan cichlid (Cichlasoma urophthalmus) was first confirmed in Florida in 1983, when numerous individuals were found in the northeastern Florida Bay. Since then, this species has continued to expand its range northward. The capture, beginning in October 2004 to present, of large numbers of Mayan cichlids from central Florida's east- and west-coast mangrove systems north of 28°N latitude is documented here. Mayan cichlids in a wide range of sizes (estimated ages 0-7 years) at both east- and west-coast sites were collected. In addition, macroscopic examination of gonads showed the presence of developing eggs. The occurrence of multiple age-classes, maturing individuals, cichlid nests, and juveniles, plus repeated collections over a four-year period, indicates that the Mayan cichlid is successfully reproducing and surviving the average winter temperatures in some estuarine waters in central Florida.

  12. The influence of colony size and coral health on the occupation of coral-associated gobies (Pisces: Gobiidae)

    NASA Astrophysics Data System (ADS)

    Schiemer, L.; Niedermüller, S.; Herler, J.

    2009-03-01

    Fishes of the genus Gobiodon are habitat specialists by their association with Acropora corals. Little is known about the parameters that define host coral quality for these fishes, in particular their breeding pairs. Data were collected in the northern Red Sea using 10 × 1-m belt transects in different reefs and zones. Gobiid density was highly correlated with coral density over all sites and zones, and the more specialized goby species preferred coral species that are less vulnerable to environmental stress. Moreover, the occupation rate of corals by goby breeding pairs significantly increased with colony size and decreased with partial mortality of colonies. Logistic regression showed that both coral size (being most important) and partial mortality are key factors influencing the occupation by breeding pairs. This study provides the first evidence that breeding pairs of coral-associated gobiids have more advanced habitat requirements than con-specifics in other social states. As coral reefs are threatened worldwide and habitat loss and degradation increase, this information will help predict the potential effects on those reef fishes obligatorily associated with live corals.

  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. 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.

  15. Notes on Galápagos grenadiers (Pisces, Gadiformes, Macrouridae), with the description of a new species of Coryphaenoides.

    PubMed

    Iwamoto, T; McCosker, J E

    2001-07-01

    Two unusual specimens of the grenadier genus Coryphaenoides were collected by the deep-submersible vehicle Johnson Sea-Link off the Galápagos. Unlike any other member of the genus, the snout in these specimens was rounded, non-protruding, naked anteriorly and ventrally, with no tubercular scales marking the terminal and lateral angles. They are herein described as Coryphaenoides gypsochilus. Additional specimens of grenadiers were procured by the Johnson Sea-Link, including the second and third specimens of Nezumia ventralis and the first record of Caelorinchus canus from these waters. Three species and one subspecies of Galápagos grenadiers are endemic.

  16. 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.

  17. Ultrastructural study of the spermatozoon of Pronoprymna ventricosa (Digenea, Baccigerinae), parasite of the twaite shad Alosa fallax Lacepede (Pisces, Teleostei).

    PubMed

    Quilichini, Yann; Foata, Josephine; Marchand, Bernard

    2007-09-01

    In this paper, we describe the ultrastructural organisation of the spermatozoon of a Digenea Baccigerinae Pronoprymna ventricosa. This spermatozoon possesses the elements found in the others digeneans: two axonemes with 9 + "1" pattern, a mitochondrion, a nucleus, cortical microtubules and external ornamentations. However, this spermatozoon presents two particularities. The first is the presence of a single field of cortical microtubules disposed in the ventral side (mitochondrion side) of the spermatozoon. In the other digeneans, two fields of cortical microtubules are observed between the two axonemes. The second is the presence of external ornamentations not associated with cortical microtubules. These two points have, to our knowledge, never been described in another digenean. Moreover, a separation in two groups of the digenean spermatozoa is proposed in relation to the localisation of the external ornamentations. We propose to distinguish a first group exhibiting these elements in the proximal part of the spermatozoon and a second one with external ornamentations in a second part of the gamete.

  18. 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.

  19. Surface ultrastructure of the gills of the mullets Mugil curema, M. liza and M. platanus (Mugilidae, Pisces).

    PubMed

    Eiras-Stofella, D R; Charvet-Almeida, P; Fanta, E; Vianna, A C

    2001-02-01

    Mugil curema, M. liza, and M. platanus were collected from the southeastern and southern coast of Brazil. The second gill arches were analyzed by scanning electron microscopy and histology. The highest density of chloride and mucus-secreting cells was observed in the gill filaments of M. liza and M. platanus. Spines are scarce and were found only in the pharyngeal region of M. curema. The dorsal angle of curvature of the simple projections is most reduced in the rakers of M. liza and M. platanus. The raker borderline on the internal side of the arches of M. curema has grooves that do not occur in the other two species. On the external side of the branchial arches, the borders of the rakers of M. liza and M. platanus are smooth. The shape of the rakers is characteristic for each species: in M. curema, it resembles the letter "D"; in M. liza, it is trapezoidal, and in M. platanus, it is triangular. Thus there is a morphologic similarity between M. liza and M. platanus, and both differ from M. curema. All three species show elongated and extremely elaborated rakers that are placed next to each other and turned toward the opercular cavity. There are few taste buds and only several mucus-secreting cells along the whole pharyngeal region. These characteristics suggest that these species do not select food chemically but obtain it mechanically with the rakers and aggregate it with mucus.

  20. 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.

  1. Abundance variation of Porichthys margaritatus (Pisces: Batrachoididae) throughout thermic and bathymetric gradients in the central Mexican pacific.

    PubMed

    Godínez-Domínguez, E; Aguilar-Palomino, B; González-Sansón, G

    2001-06-01

    Three cruises, one in each of the main stream patterns in the area, were made on the central Mexican Pacific continental slope (May-June 1995, November 1995, and March 1996). Seven trawl sampling sites were defined per cruise, and in each site four bathymetric levels were sampled (20, 40, 60, and 80 m). During the warmest seasons, the highest abundance of Porichthys margaritatus was at 60 m. When the temperature of the bottom water was lower, in March 1996, the highest abundance of P. margaritatus moved towards 40 m. The depths with greatest abundance fluctuated between 18 and 21 degrees C, indicating a narrow temperature preference range. A Gaussian model was used to explain the relation between abundance and temperature.

  2. Effects of benzo(a)pyrene on the early development of California grunion, Leuresthes tenuis (pisces, atherinidae)

    SciTech Connect

    Winkler, D.L.; Duncan, K.L.; Hose, J.E.; Puffer, H.W.

    1983-07-01

    Benzo(a)pyrene (BaP), which is carcinogenic and mutagenic in mammals, exists worldwide in the marine environment. Sources of this polycyclic aromatic hydrcarbon include oil spills, industrial effluents, and atmospheric fallout. This study is the first to examine the effects of BaP on the embryonic development of a teleost, the California grunion. Gametes were stripped from spawning adults and eggs were artificially fertilized. The fertilized eggs were then incubated for up to 14 days with initial concentrations of BaP ranging from 0 to 869 ppb. Steady-state tissue levels of BaP ranged from 0.46 to 19.92 ppm, which represented bioaccumulation factors of 146-437 times the steady-state BaP concentrations in seawater. When compared with controls, embryos exposed to initial BaP levels of 24 ppb or greater showed decreased hatchings, reduced notochord lengths, and increased morphological abnormalities. These results suggest that exposure of grunion embryos to BaP in contaminated areas may lead to their decreased survival.

  3. Aggressive behaviour of an epigean population of Astyanax mexicanus (Characidae, Pisces) and some observations of three subterranean populations.

    PubMed

    Burchards, H; Dölle, A; Parzefall, J

    1985-08-01

    The different populations have been tested for aggressive behaviour in groups of four to eight animals of both sexes in tanks ranging from 251 to 9501. In darkness less aggressive behaviour has been observed with the help of an infrared video-camera in the epigean fish and the eyed Micos cave fish. The strongest degree of reduction in aggressive behaviour is shown by the totally blind populations. The aggressiveness increases in the epigean fish as soon as space and food supply diminish.

  4. Host and environmental risk factors associated with Cryptosporidium scophthalmi (Apicomplexa) infection in cultured turbot, Psetta maxima (L.) (Pisces, Teleostei).

    PubMed

    Alvarez-Pellitero, Pilar; Perez, Andrés; Quiroga, M Isabel; Redondo, M José; Vázquez, Sonia; Riaza, Ana; Palenzuela, Oswaldo; Sitjà-Bobadilla, Ariadna; Nieto, José M

    2009-11-12

    An epidemiological cohort study of Cryptosporidium scophthalmi in cultured turbot Psetta maxima L. of Northwestern Spain was conducted along a four-year period. Four different ongrowing cohorts were monitored monthly from introduction into the ongrowing tanks (10-50 g) until reaching market size (400-1400 g). The association of host and environmental factors with five categories of parasite abundance was assessed using a multivariable regression framework. Epidemiological factors assessed here were water temperature, weight, length, month of collection, season, age, origin, condition factor, water filtration, and status to the myxozoan Enteromyxum scophthalmi infection. E. scophthalmi was included into the analysis because it targets the same organ than C. scophthalmi and it was prevalent in the studied population. The multivariable analysis demonstrated the statistically significant association between several factors and parasite abundance. C. scophthalmi abundance was associated (P<0.05) with age, condition factor, season, and status to E. scophthalmi infection. Young animals, with poor condition factor, during spring or summer, and not infected with the myxozoan were most likely to be highly infected by C. scophthalmi. Inclusion of these four variables significantly (P<0.05) improved the model, compared to the model that did not include any of these epidemiological factors. Increasing levels of C. scophthalmi abundance were associated (P<0.01) with higher severity of C. scophthalmi-compatible lesions. The frequency of distribution of C. scophthalmi abundance was clearly right-skewed and fitted a negative binomial distribution, whereas the intensity of infection fitted a Poisson distribution. The quantification of the variance-to-mean ratio stratified by age demonstrated overdispersion for 8-16 months old fish, although this bivariate association is likely affected by several other factors, as suggested by the results of the multivariable analysis. The negative relation between C. scophthalmi abundance and status to E. scophthalmi infection suggests differences in the transmission, onset, and course of both infections. The coarse filtration used in some cohorts did not significantly affect the levels of infection. C. scophthalmi was probably introduced into the ongrowing tanks mainly with carrier fish, though the involvement of infective oocysts from the water supply cannot be disregarded. Infection prevalence and mean intensity decreased with fish age and a seasonal distribution was found. Results presented here will help to understand the epidemiology of C. scophthalmi in turbot, to estimate the expected levels of infection associated with presence or absence of epidemiological factors, and to quantify the impact that the disease may have on susceptible turbot populations. The multivariable model used here is more powerful than the visual inspection of graphics for exploring associations in cooperative processes and can be easily extended to the assessment of epidemiological associations in other population and parasitic diseases.

  5. 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.

  6. Extreme clonal uniformity of Phoxinus eos/neogaeus gynogens (pisces: Cyprinidae) among variable habitats in northern Minnesota beaver ponds.

    PubMed Central

    Elder, J F; Schlosser, I J

    1995-01-01

    Genetic surveys of parthenogenetic vertebrate populations have demonstrated a common pattern of relatively high degrees of clonal variation and the coexistence of numerous clones. In striking contrast, the Phoxinus eos/Phoxinus neogaeus/hybrid gynogen complex of cyprinid fishes exhibits no clonal variation within a northern Minnesota drainage characterized by successional beaver ponds. Gynogens were sampled from three habitats in each of four different pond types in a single drainage in Voyageurs National Park, Minnesota. The abundance of gynogens relative to sexual dace varied with pond type, being least common in deep upland ponds and most common in shallow, collapsed, lowland ponds (13.4% and 48.6%, respectively). Simple-sequence multilocus DNA fingerprinting of 464 individual gynogens detected one, and only one, clone. DNA fingerprints, generated sequentially by using three oligonucleotide probes, (CAC)5, (GACA)4, and the Jeffreys' 33.15 probe, all revealed the same unprecedented lack of variation. The extreme lack of clonal diversity in these gynogens across a range of habitat types does not fit the general pattern of high clonal diversity found within populations of other vertebrate parthenogens. Images Fig. 1 Fig. 2 PMID:7761438

  7. 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.

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

    PubMed Central

    Berdugo, Gilberto Orozco; Narváez Barandica, Juan C.

    2014-01-01

    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

  9. Seasonal and ontogenetic changes modulate oxygen consumption and antioxidant defenses in the cutlassfish Trichiurus lepturus (Pisces, Trichiuridae).

    PubMed

    Filho, Danilo Wilhelm; Fraga, César G; Boveris, Alberto

    2017-03-24

    Several oxidative stress markers and liver oxygen consumption were measured in different tissues of the marine fish Trichiurus lepturus in late summer and late winter, as well as in juveniles and adult females. Oxygen consumption in liver, superoxide dismutase (SOD) and catalase (CAT) activity in liver, red cells, lens and roe, vitamin E, ubiquinol10, β-carotene in liver, red cells, and roe, as well as contents of reduced glutathione (GSH) and lipoperoxidation (TBARS) in red cells were evaluated. Regarding ontogeny, compared to adult fish, juveniles showed significant higher SOD activity in liver and lens, as well as higher liver contents of vitamin E. In contrast, adult females showed higher contents of vitamin E in roe, ubiquinol10 in liver and roe, and higher GSH levels in red cells, while the other markers remained unchanged. Regarding seasonal changes, no differences were detected in adult females for liver CAT and ubiquinol10, CAT in roe, vitamin E in roe and in red cells, liver and red cell ubiquinol10, and in GSH in red cells. However, and coinciding with the spawning period of late summer, liver oxygen consumption, SOD and CAT activity and ubiquinol10 contents in roe and SOD activity in red cells, and red cell TBARS contents were higher compared to late winter. These temporal antioxidant adjustments of Trichiurus lepturus seem to be parallel to the higher oxygen consumption typical of juvenile forms and also to the intense spawning and foraging activities of adult females in late summer.

  10. 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.

  11. 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.

  12. Ultrastructural study of vitellogenesis and oogenesis of Crepidostomum metoecus (Digenea, Allocreadiidae), intestinal parasite of Salmo trutta (Pisces, Teleostei)

    PubMed Central

    Greani, Samuel; Quilichini, Yann; Marchand, Bernard

    2016-01-01

    We describe the vitellogenesis and oogenesis of Crepidostomum metoecus from Salmo trutta collected in Corsica. This is the first study conducted in the Allocreadiidae family. The maturation of C. metoecus vitellocytes comprises four different stages depending on organelle content. The follicular vitellarium is surrounded by a basal lamina. Vitellocytes are randomly distributed into the vitellarium, although fully mature vitellocytes are found in the center of the follicle. During maturation, the nucleo-cytoplasmic ratio decreases, whereas synthetic activity increases. Fully mature vitellocytes are filled with β-glycogen particles and shell globule clusters. Compared to other trematodes studied, C. metoecus possesses a large amount of nutritive reserves for the developing embryo and high quantities of material for the developing shell. Oocyte maturation takes place in four stages: oogonia, primary oocytes, developing oocytes, and mature oocytes. Developing oocytes enter the zygotene-pachytene stage of the first meiotic division recognizable by the presence of synaptonemal complexes in the nucleoplasm. The low protein composition of mature oocytes associated with the large nutrient content of vitellocytes of C. metoecus enables us to consider that oocytes do not take part of the nutrition of the future embryo of the miracidium. A cytochemical test (Thiéry method) allowed us to detect the presence of polysaccharides and glycogen during maturation of these two cell types. PMID:27845028

  13. Sperm ultrastructure of the digenean Aphallus tubarium (Rudolphi, 1819) Poche, 1926 (Platyhelminthes, Cryptogonimidae) intestinal parasite of Dentex dentex (Pisces, Teleostei).

    PubMed

    Foata, J; Quilichini, Y; Greani, S; Marchand, B

    2012-02-01

    The ultrastructural organization of the spermatozoon of a cryptogonimid digenean, Aphallus tubarium, a parasite of Dentex dentex, is described. The spermatozoon possesses the elements found in other digeneans: two axonemes with 9+"1" pattern, a mitochondrion, a nucleus, cortical microtubules, external ornamentation and spine-like bodies. However, the mitochondrion appears as a cord with a bulge; this characteristic has never been described in other studied cryptogonimid and in other digeneans except in one lepocreadiid, Holorchis micracanthum. Likewise, the presence of a thin cytoplasm termination in the anterior part of the spermatozoon has never been pointed out in the cryptogonimids.

  14. [Feeding habits of Lutjanus guttatus (Pisces: Lutjanidae) at Los Cóbanos and Puerto La Libertad, El Salvador].

    PubMed

    Rodrigo Rojas, José; Maravilla, Erick; Chicas, Francisco

    2004-03-01

    Abstract: A total of 175 spotted snapper Lutjanus guttatus were collected monthly in the Los Cobanos and Puerto La Libertad, El Salvador, from January to December 2000 to determine its feeding habits. The fishes studied ranged 9.8 - 58.0 cm in total length. Were collected using push-net and hook and line. This snapper is a bentonic opportunistic carnivorous predator. The total biomass of the stomach contents was 260.5 g. Crustaceans (Squillidae, Portunidae, Dynomenidae. Penaeidae, Sicyoniidae, Callianassidae), were the most abundant group: they accounted for 50.4% of the total biomass. Numerically, Portunus asper was the most abundant prey. Ontogenic differences were observed in the diet. In juveniles (16 cm TL). at any time of the year, the most frequent and abundant components were crustaceans and in adults were crustaceans, fishes and mollusks. The relative importance of different components of the diet was assessed with two indexes that combine. in different ways. percentage frequency of occurrence, percentage number and percentage weight of prey categories. The commercial use this resource and the absence of management strategies are discussed.

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

    PubMed

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

    2015-03-01

    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.

  16. 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.

  17. 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.

  18. [Embryonic and Larval Development of the Asian Seabass Lates calcarifer (Pisces: Perciformes: Latidae) under Thermostatically Controlled Conditions].

    PubMed

    Shadrin, A M; Pavlov, D S

    2015-01-01

    Material for this study was obtained from the hatchery with brood stock of Lates calcarifer that originated from a natural population living in inshore waters off Central Vietnam. Commercial interest in L. calcarifer as an object of mariculture and wildstock fishery has resulted in several publications on its early life history; nevertheless, comprehensive description of early development of L. calcarifer based on controlled incubation of embryos and larvae has remained absent. In the present paper embryonic and larval development to the stage of anlage of pelvic fins is described in detail and illustrated with original drawings of live material on the basis of thermostatically controlled incubation of embryos at 27°C and larvae at 26.8°C (26.5-28.0°C). The first cleavage furrow appeared at the age of 33.5 min. The duration of synchronous cleavage cycle was 16 min. About 80% of all embryos hatched at the age of 18 h. The length of newly hatched larva during the first hour after emergence from the egg shell was 1.63 ± 0.016 mm (1.50-1.75 mm). Chronology of development of the organs, early circulatory system, and pigmentation pattern is given. The dynamics of change in the trunk and caudal body segment number in larva from hatching to the moment of anlage of pelvic fins is shown. The total number of body segments reached the maximum value of 26-27 soon after hatching and then decreased to 20-21 segments. Newly received data are discussed in a comparative context of development of some other teleosts.

  19. Feeding habits of the deep-sea fish, Scopelogadus beanii (Pisces: Melamphaide), in the western North Atlantic

    NASA Astrophysics Data System (ADS)

    Gartner, John V.; Musick, John A.

    1989-10-01

    Stomach contents were examined from 106 specimens (37-113 mm SL) of the melamphaid Scopelogadus beanii collected from the slope waters of the western North Atlantic Ocean by bottom and midwater trawls. Seventy-five stomachs (70.8%) contained food. Gelatinous zooplankton (mainly salps) and associated obligate and facultative symbiotic hyperiid amphipods of the genera Vibilia, Parathemisto, and Phronima were the predominant food items in the stomachs of S. beanii, although calanoid copepods (especially Paraeuchaeta norvegica) were of similar importance in individuals from offshore midwater trawls. Other pelagic prey items included halocyprid ostracods, euphausiids and fishes. Representatives from three benthic groups (gammaridean amphipods, polychaetes and pelecypods) were recovered from stomachs of specimens from bottom trawls. The only significant pattern observed in diel feeding periodicity was a decrease in the percentage of stomachs containing food between 1201 and 1800 h as compared to the percentage of stomachs containing food between 1201 and 2400 h. This observation might be an artifact, however, because no differences in degree of prey digestion were observed. Limited seasonal data from bottom-trawled collections indicate that consumption of amphipods was highest in spring, whereas that of gelatinous plankton was highest in summer and autumn. There were no apparent ontogenetic shifts in diet composition. Differences in prey importance between bottom and pelagic trawl-captured individuals may be due to vertical ranges and abundance of prey taxa and the presence of S. beanii near the bottom in continental slope waters.

  20. [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.

  1. A management plan for the sport fishery of Parachromis dovii (Pisces: Cichlidae) in Hule lake, Costa Rica.

    PubMed

    Tabash, F A; Guadamuz, E

    2000-01-01

    A first attempt to regulate the fishing activity while preserving the species and its habitats is presented for Hule lake. We intensively sampled the "guapote" between March 1996 and April 1997 using monofilament gill nets and a floating line, collecting 421 individuals. P. dovii biomass was relatively low; this species had a long life cycle (8-10 years) and the growth oscillation was low (C = 0.3). Maximum life expectation was estimated at 12 years and the point of minimum growth coincided with the spawning that takes place between November and December. After spawning, P. dovii take around seven months to reach recruitment size (54.6 mm). The length for sexual maturity was 134 mm Lt, which indicates that this species is viable for reproduction soon after leaving the protection zones around the lagoon. "Guapote" sport fishing in the Hule lake is in equilibrium, the renewal rate is 80%. An increment in the actual fishery effort is not recommended, since it could seriously affect the natural renewal capacity of the stock.

  2. Lipids in the skin of a cat-fish Heteropneustes fossilis (Bloch) (Heteropneustidae, Pisces). A histochemical investigation.

    PubMed

    Mittal, A K; Rai, A K; Banerjee, T K; Agarwal, S K

    1976-08-25

    Localization and characterization of different lipids in the cellular constituents of the skin of Heteropneustes fossilis has been made using several histochemical techniques. High contents of cholesterol, its esters and phospholipids have been correlated with the metabolically active state of the basal cells undergoing cell proliferation and differentiation. The polygonal cells in the outermost layer of the epidermis, though rich in phospholipid contain small amounts of cholesterol and its esters. This has been correlated with the metabolically less active state of theses cells. Neutral lipids and phospholipids in the polygonal cells of the outermost layer may contribute to the contents of surface slime and act as an efficient barrier for the penetration of water through the skin. The deposits of neutral lipids in the subcutis may provide energy during the period of fasting, act as a barrier for water diffusion through the skin and serve as shock absorbing pads protecting the fish from mechanical injury.

  3. A new species of Pseudocrepidobothrium (Cestoda: Proteocephalidea) from Pseudoplatystoma reticulatum (Pisces: Siluriformes) in the Paraná River basin (Argentina).

    PubMed

    Arredondo, Nathalia J; De Pertierra, Alicia A Gil; De Chambrier, Alain

    2014-10-01

    This study describes the proteocephalidean tapeworm Pseudocrepidobothrium chanaorum sp. n. (Proteocephalidae: Proteocephalinae), which was found in the intestine of Pseudoplatystoma reticulatum (Eigenmann et Eigenmann) from the Colastiné River, a tributary of the Paraná River. The new species differs from the two other species of the genus, P. eirasi (Rego et de Chambrier, 1995) and P. ludovici Ruedi et de Chambrier, 2012, parasites of Phractocephalus hemioliopterus (Bloch et Schneider) from the Amazon River in Brazil, in having fewer proglottides (4-8 without ventral appendages vs 7-12 with ventral appendages and 20-36 without ventral appendages, respectively), a smaller scolex (350-450 μm wide vs 495-990 μm and 515-1020 μm wide, respectively), in the total number of testes (21-25 vs 21-51 and 37-79, respectively), a cirrus-sac usually directed anteriorly if the vagina is posterior to the cirrus-sac vs transversely situated in the known species. The study of the tegumental surface of Pseudocrepidobothrium spp. revealed the presence of four types of microtriches: papilliform, acicular and capilliform filitriches, and gladiate spinitriches. The three species have a similar microthrix pattern, with minor differences on the immature proglottis surface. Pseudocrepidobothrium chanaorum sp. n. is the ninth proteocephalid reported from P. reticulatum.

  4. 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.

  5. 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.

  6. Unique patterns of pelvic fin evolution: a case study of balistoid fishes (Pisces: Tetraodontiformes) based on whole mitochondrial genome sequences.

    PubMed

    Yamanoue, Yusuke; Miya, Masaki; Matsuura, Keiichi; Sakai, Harumi; Katoh, Masaya; Nishida, Mutsumi

    2009-01-01

    Balistoid fishes have a unique and reduced pelvic fin structure, which does not exhibit paired structures. The pelvic complex exhibits reductive trends, but its rudimentary structure was retained among balistoids, and its unidirectional and parsimonious reduction in more derived lineages has been hypothesized based on morphology. We investigated the evolution of pelvic complex reduction in balistoids using whole mitochondrial genome (mitogenome) data from 33 species (27 newly determined during the study) that represent the entire morphological diversity of balistoids. Partitioned maximum likelihood and Bayesian analyses were conducted with two datasets that comprised concatenated nucleotide sequences from 13 protein-coding genes (all positions included; third codon positions converted into purine [R] and pyrimidine [Y] [RY-coding]) plus 22 transfer RNA and two ribosomal RNA genes. The resultant trees were well resolved and largely congruent, with most internal branches having high support values. The mitogenomic datasets strongly supported monophylies of both balistids and monacanthids, but rejected previous hypotheses on the intra-relationships in each family. The present tree topology revealed that highly reduced pelvic complexes had multiple origins, and optimization of the traits on the resultant tree strongly suggested the non-unidirectional and independent reduction of pelvic complexes in balistoids. The evolution of balistoid pelvic structure is very different among fishes that exhibit its reductive trends, and this uniqueness in pelvic evolution may be a link to their reproductive behaviors.

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

    PubMed

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

    2015-12-01

    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.

  8. 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.

  9. Age, reproduction and fecundity of the spined loach Cobitis taenia L. (Pisces, Cobitidae) from Lake Klawój (Poland).

    PubMed

    Juchno, Dorota; Boroń, Alicja

    2006-07-01

    This is the first study concerning the features of the reproduction process of the karyologically identified spined loach C. taenia (2n=48). The histology of 71 ovaries, and gonadosomatic index (GSI) of karyologically identified spined loach Cobitis taenia L. from Lake Klawój (Northern Poland) were examined. The absolute and relative fecundity of 25 females was estimated by gravimetric method. The age of fish was determined according to the annual increments of otholits. The spawning of C. taenia from Lake Klawój took place from May to July, at a water temperature exceeding 18.5 degrees C. The GSI values at the beginning of the reproduction period ranged from 7 to 19%. The average absolute fecundity of females was 2078 eggs, with the number ranging from 869 to 3371 eggs. High individual variability in the gonad histology and the GSI values during the reproductive period was observed. Such variability could be the result of beginning the reproduction process in the fish at various times and, probably, due to the various numbers of batches laid and various numbers of eggs per batch.

  10. Old fish in a young lake: stone loach (Pisces: Barbatula barbatula) populations in Lake Constance are genetically isolated by distance.

    PubMed

    Barluenga, Marta; Meyer, Axel

    2005-04-01

    The genetic structure of 10 populations (453 individuals) of stone loach (Barbatula barbatula L.), a small bottom-dwelling cyprinid fish, in the littoral zone of Lake Constance, central Europe, was investigated by analysing the mitochondrial control region sequences and five microsatellite loci. An unexpectedly high degree of genetic diversity (up to 0.36%) and old estimated age of these populations (> 150 000 years) based on mitochondrial DNA (mtDNA) was found. These findings contrast with the relatively young age of the lake, which could be colonized by fish only after the last ice age around 15 000 bp. Stone loach appears to be an old species in a young lake. Both types of molecular markers showed population genetic structure pronounced in mtDNA (overall F(ST) = 0.15) but moderate in microsatellites (F(ST) = 0.03). As predicted by its life history, philopatry, and limited capacity for dispersal, stone loach populations of Lake Constance show a clear pattern of isolation by distance. Geographic distances along the shores are the best explanation for the observed geographical distribution of genetic differentiation (r = 0.88), indicating that open water represents a barrier for the dispersal of the stone loach. The colonization of Lake Constance might have occurred initially at one location and then populations spread throughout the lake in a stepwise manner following the shoreline, and subsequently remained largely genetically isolated as suggested by the large observed differences among them.

  11. 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.

  12. 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.

  13. [Reproduction and feeding habits of Mustelus dorsalis (Pisces: Triakidae) in the Gulf of Nicoya, Costa Rica: elements for a sustainable management].

    PubMed

    Rojas M, José Rodrigo

    2006-09-01

    A total of 311 sharptooth smooth-hound Mustelus dorsalis were collected in the Gulf of Nicoya, Costa Rica from March 1999 to May 2000 to determine reproduction and feeding habits. The fishes were collected using hook and line. 250 females and 61 males were identified. The females are bigger (550-660 mm) and heavier (400-1,000 g) than males (500-585 mm and 200-300 g, respectively). All samples collected were mature and the minimum length to first maturity observed is 500 and 541 mm for females and males, respectively. From September to March individuals were mature, while samples caught during April and August were immature. A total of 1,259 embryos were analyzed. Number of embryos per liter ranged from two to six, the total length is from 130 to 205 mm and the weight from 6 to 35 g. This shark is a polyphagous opportunistic carnivore that preys on crustaceans (Squilla hancocki, S. parva, Litopenaeus sp.), fishes (Anchoa sp., Caranx sp., Lutjanus sp., Engraulis sp.) and mollusks (Loligo sp. and Octopus sp.). Main prey item was S. hancocki. The presence of mature sharks of both sexes along the year and the consumption of food items associated to shallow coastal rocky waters suggest that this sector of Nicoya Gulf is a nursery ground and an essential habitat. Based on these results the establishment of an integral management plan is proposed.

  14. Intersex and liver alterations induced by long-term sublethal exposure to 17α-ethinylestradiol in adult male Cnesterodon decemmaculatus (Pisces: Poeciliidae).

    PubMed

    Young, Brian Jonathan; López, Gabriela Carina; Cristos, Diego Sebastián; Crespo, Diana Cristina; Somoza, Gustavo Manuel; Carriquiriborde, Pedro

    2016-07-06

    The aim of the present study was to assess the responses of the gonopodium morphology and the gonadal and liver histology of adult male Cnesterodon decemmaculatus to sublethal long-term exposure concentrations of 17α-ethinylestradiol (EE2). Two experiments were conducted exposing the fish to waterborne concentrations of EE2 ranging from 20 ng/L to 200 ng/L for 8 wk, 12 wk, and 16 wk. Intersex gonads were observed after 8 wk and 16 wk in fish exposed to 200 ng EE2/L and 100 ng EE2/L, respectively. Oocytes' development from testis germ cells and replacement of the efferent duct periodic acid-Schiff-positive secretion surrounding spermatozeugmata by parenchymal tissue and duct structure alterations were the major observed changes in the gonads. In contrast, no response was observed in the gonopodium morphology. Liver histology was also altered, showing increasing steatosis, single-cell necrosis to generalized necrosis, and disruption of acinar organization from 100 ng EE2/L to 200 ng EE2/L. In summary, the present results showed that although EE2 was not able to alter the morphology of a developed gonopodium, it was capable of inducing development of testicular oocytes in adult male C. decemmaculatus at environmentally relevant concentrations. Thus, externally normal but intersex C. decemmaculatus males would be expected in the wastewater-receiving streams that the species inhabits. According to the literature, the present study would be the first indicating estrogen-induced intersex in adult male poeciliid. Environ Toxicol Chem 2016;9999:1-8. © 2016 SETAC.

  15. [Feeding habits and trophic ecology of the fish Lutjanus griseus (Pisces: Lutjanidae) associated with submerged vegetation in Laguna de Términos, Campeche, Mexico].

    PubMed

    Guevara, Emma; Alvarez, Hernán; Mascaró, Maite; Rosas, Carlos; Sánchez, Alberto

    2007-01-01

    In Campeche, Mexico, the Laguna de Términos has Thalassia testudinum beds inhabited by the grey snapper, Lutjanus griseus (Linnaeus 1758). Along one year, we collected 994 individuals and 672 had food in their stomachs; we recorded number, weight, and frequency oftrophic groups, and the index of relative importance. Dominant food components were Farfantepenaeus duorarum and Palemonetes octaviae, Eucinostomus gula (Cuvier 1830) and Libinia dubia. Salinity and temperature were related to the number of individuals collected and with greater fish consumption by large L. griseus. The trophic niche breadth index was calculated for six size-classes of fish. The smallest and the largest fish had the lowest index values, whereas medium-size snappers had higher values. This snapper has a preference for habitats with submerged vegetation. The percentage of fish with food in their stomachs was higher during dark hours, providing evidence of the nocturnal habits of this fish.

  16. 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

    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.

  17. Evaluation of environmental quality of two estuaries in Ilha do Maranhão, Brazil, using histological and genotoxic biomarkers in Centropomus undecimalis (Pisces, Centropomidae).

    PubMed

    Cantanhêde, Sildiane Martins; da Silva Castro, Geane; Pereira, Natália Jovita; de Pinho Campos, Jonas Silva; da Silva, Juliana; Tchaicka, Lígia; Neta, Raimunda Nonata Fortes Carvalho; de Souza Torres, José Ribamar; Santos, Débora Martins Silva

    2016-10-01

    Estuaries are subjected to continual environmental impacts from activities in the catchment areas. This research assessed the quality of two estuarine habitats located in Ilha do Maranhão, Brazil, through histological and genotoxic biomarkers in Centropomus undecimalis, comparing the data obtained to metal, physical, and chemical concentrations of water samples. The gill histological alterations were analyzed by the histological alteration index and genotoxic lesions in erythrocytes were detected by the Micronucleus Test. The analysis of metals revealed that all water samples contained at least two elements with concentrations higher than that allowed by the current Brazilian law. For gill histological analysis, snook of both areas assessed exhibited moderate lesions, indicating that the local fish are affected by environmental stress. Micronucleus analysis of snook showed that the Bacanga river basin is the most affected. In addition to assessing the health of commercial fish populations, the information about the biomarkers used for the species can serve to contribute to the preparation and/or application of health assessment models and implementation of environmental recovery policies for coastal aquatic environments.

  18. 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.

  19. 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.

  20. Distribution, morphology, and biochemical genetics of Coryphaenoides armatus and C. yaquinae (Pisces:Macrouridae) in the central and eastern North Pacific

    NASA Astrophysics Data System (ADS)

    Wilson, Raymond R.; Waples, Robin S.

    1983-11-01

    A morphological and electrophoretic analysis of Coryphaenoides armatus (Hector) and C. yaquinae Iwamoto and Stein was made because their morphological similarity has led to their confusion by previous workers and generated uncertainty about their specific distinctness. The results show that C. armatus and C. yaquinae are closely related but distinct species and are distinguihable by differences in the number and arrangement of premaxillary and mandibular rows of teeth, and by fixed differences in electromorphs at five presumptive gene loci: Mdh-1, Mdh-2, Sod, Gdh, and Gpi-A. The respective distribution in the central and eastern North Pacific are also distinct. C. armatus ranges mostly along the continental rise and slope of western North America between about 2000 and 4300 m, whereas C. yaquinae ranges mostly in the North Pacific basin to at least 5825 m and co-occurs with C. armatus between about 3400 and 4300 m on the continental rise. The distributions are explained by suggesting that C. yaquinae is adapted for life beneath the North Pacific central gyre by virtue of a reduced metabolic rate relative to C. armatus.

  1. Molecular characterization of Hysterothylacium fabri (Nematoda: Anisakidae) from Zeus faber (Pisces: Zeidae) caught off the Mediterranean coasts of Turkey based on nuclear ribosomal and mitochondrial DNA sequences.

    PubMed

    Pekmezci, Gokmen Zafer; Yardimci, Banu; Onuk, Ertan Emek; Umur, Sinasi

    2014-02-01

    In the present study, Hysterothylacium fabri was found in the coasts of the Mediterranean Sea, Turkey and characterized by sequencing of nuclear (internal transcribed spacer, ITS) and mitochondrial (cytochrome c oxidase subunit 2, cox2) markers. Pairwise comparison between the entire ITS fragment including ITS-1, 5.8S, ITS-2 sequences of the H. fabri isolates from the Mediterranean Sea (Turkey, KC852206) and other H. fabri isolates from the South China Sea (JQ520158), the South Korea waters (JX974558) showed differences ranged from 0.1 and 1.1%. With the present study, H. fabri from the Mediterranean Sea was characterized for the first time by sequencing of the cox2 gene.

  2. A comparison of ages estimated by the polarized light method with ages estimated by vertebrae in females of Coryphaenoides acrolepis (Pisces: Macrouridae)

    NASA Astrophysics Data System (ADS)

    Wilson, Raymond R.

    1982-11-01

    Rings of scales seen by the use of polarized light are compared to those of vertebral centra of the Pacific grenadier Coryphaenoides acrolepis (Bean). Although the number of rings in the two structures from the same individual show significant statistical agreement, strict numerical agreement occurred in only 22 out of 100 comparisons. Ageing by either technique produced comparable logistic growth curves.

  3. Three new species of Hatschekia Poche, 1902 (Copepoda: Siphonostomatoida: Hatschekiidae) parasitic on Abalistes filamentosus (Pisces: Tetraodontiformes: Balistidae) from off Okinawa, Japan.

    PubMed

    Uyeno, Daisuke; Nagasawa, Kazuya

    2009-11-01

    Three new species of the copepod genus Hatschekia Poche, 1902, H. lima n. sp., H. cylindrus n. sp. and H. sunaoi n. sp., are described from the gill filaments of a triggerfish, Abalistes filamentosus Matsuura & Yoshino, caught off the Ryukyu Islands, Okinawa, Japan. These new species share an unusual morphological character, i.e. four stout posterior spines on the intercoxal sclerites of legs 1 and 2. H. lima n. sp. differs from its congeners in having a robust inner lobe on the maxillule and leg 3 with a swollen basal lobe. H. cylindrus n. sp. is distinguishable from its congeners by having a cephalothorax fused to the trunk and a double-semicircular chitinous frame. H. sunaoi n. sp. is characterised by leg 3 with a swollen basal lobe and an oval cephalothorax.

  4. 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

  5. A new species of the blind cave gudgeon Milyeringa (Pisces: Gobioidei, Eleotridae) from Barrow Island, Western Australia, with a redescription of M. veritas Whitley.

    PubMed

    Larson, Helen K; Foster, Ralph; Humphreys, William F; Stevens, Mark I

    2013-02-19

    A new species of the eyeless eleotrid genus Milyeringa is described from wells sunk on Barrow Island, Western Australia. Milyeringa justitia n. sp. is the third species of the genus to be named. Morphological data and cytochrome c oxidase subunit I (COI) DNA sequence data from a wide sample of localities at which the genus occurs was used to evaluate relationships and species limits. Milyeringa veritas is redescribed, and M. brooksi is synonymised with M. veritas. The unique form and ecology of these fishes, plus the threats to their survival, warrants immediate and continuing attention in management.

  6. 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.

  7. Oligomeric protein complexes of apolipoproteins stabilize the internal fluid environment of organism in redfins of the Tribolodon genus [Pisces; Cypriniformes, Cyprinidae].

    PubMed

    Andreeva, Alla M; Serebryakova, Marina V; Lamash, Nina E

    2017-03-01

    One of the most important functions of plasma proteins in vertebrates is their participation in osmotic homeostasis in the organism. Modern concepts about plasma proteins and their capillary filtration are based on a model of large monomeric proteins that are able to penetrate the interstitial space. At the same time, it was revealed that a considerable amount of oligomeric complexes are present in the low-molecular-weight (LM) protein fraction in the extracellular fluids of fishes. The functions of these complexes are unknown. In the present study, we investigated the LM-fraction proteins in the plasma and interstitial fluid (IF) of redfins of the genus Tribolodon. This fish alternatively spends parts of its life cycle in saline and fresh waters. We identified the protein Wap65, serpins and apolipoproteins in this fraction. By combining the methods of 2D-E under native and denaturing conditions with MALDI, we demonstrated that only apolipoproteins formed complexes. We showed that serum apolipoproteins (АроА-I, Аро-14) were present in the form of homooligomeric complexes that were dissociated with the release of monomeric forms of proteins in the course of capillary filtration to IF. Dissociation of homooligomers is not directly correlated with the change in salinity but is correlated with seasonal dynamics. We found that there was a significant decrease in the total protein concentration in IF relative to plasma. Therefore, we suggested that dissociation of homooligomeric complexes from various apolipoproteins supports the isoosmoticity of extracellular fluids relative to capillary wall stabilization through a fluid medium in fish.

  8. Influence of water temperature on induced reproduction by hypophysation, sex steroids concentrations and final oocyte maturation of the "curimatã-pacu" Prochilodus argenteus (Pisces: Prochilodontidae).

    PubMed

    Arantes, Fábio P; Santos, Hélio B; Rizzo, Elizete; Sato, Yoshimi; Bazzoli, Nilo

    2011-07-01

    Most fishes with commercial importance from the São Francisco basin are migratory and do not complete the reproductive cycle in lentic environments, such as hydroelectric plant reservoirs, hence natural stocks are declining and there is an urgent need to reduce the pressure of fishing on those wild populations. Therefore, studies on reproductive biology and its relationship with endocrine and environmental factors are key to improving the cultivation techniques of Brazilian fish species. This study examined the influence of water temperature on sex steroid concentrations (testosterone, 17β-estradiol and 17α-hydroxyprogesterone), spawning efficiency, fecundity, fertilisation rate, larval abnormality rates and involvement of the cytoskeleton during the final oocyte maturation of Prochilodus argenteus under experimental conditions. The results of our study showed that in captivity, sex steroid plasma concentrations and spawning performance of P. argenteus were clearly different for fish kept in water with different temperature regimes. In lower water temperature (23°C), it was observed that: 33% of females did not ovulate, fecundity was lower and vitellogenic oocytes after the spawning induction procedure exhibited a smaller diameter. Moreover, concentrations of 17β-estradiol and 17α-hydroxyprogesterone were lower and there was a delay in the final oocyte maturation and, consequently, ovulation and spawning. Our experiments showed direct influence of water temperature in the process of induced spawning of P. argenteus. Changes in water temperature also suggest the tubulin involvement in the nuclear dislocation process and the possible action of actin filaments in the release of polar bodies during final oocyte maturation of P. argenteus.

  9. Embryonic and larval development of jundiá (Rhamdia quelen, Quoy and Gaimard, 1824, Pisces, TeleosteI), a South American catfish.

    PubMed

    Pereira, C R; Barcellos, L J G; Kreutz, L C; Quevedo, R M; Ritter, F; Silva, L B

    2006-11-01

    The jundiá (Rhamdia quelen, Quoy and Gaimard) is an endemic South American fish species. Because this species supports cold winters and grows faster during warm months, it has begun to be viewed as an ideal species for fish production in southern South America. In the present study, jundiá oocytes used were obtained by extrusion from females after hormone injection. Soon after hydration, the eggs were transferred to 50 L conic glass incubators, with constant and controlled water influx. Samples of fertilized eggs were transferred to Petri dishes and, examined under a stereoscopic microscope, were spherical, demersal, and non-adhesive with defined perivitelline space and resistant chorion. Cleavage stages occurred during the first 3.5 h. After hatching, larvae were transferred to 200 L glass fiber incubators. First signs of embryo movement were observed 21 h after fertilization; larval eclosion occurred 30.5 h after fertilization. Present findings may provide a basis for studies aimed at determining the complete ontogeny of jundiá and may be useful in eco-toxicological studies.

  10. 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.

  11. 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

  12. Light and scanning electron microscopy of Henneguya arapaima n. sp. (Myxozoa: Myxobolidae) and histology of infected sites in pirarucu (Arapaima gigas: Pisces: Arapaimidae) from the Araguaia River, Brazil.

    PubMed

    Feijó, M M; Arana, S; Ceccarelli, P S; Adriano, E A

    2008-10-20

    In this report, we describe Henneguya arapaima n. sp., a parasite of the gill arch and gall bladder of Arapaima gigas (pirarucu) collected in the Araguaia River, in the municipality of Nova Crixás, Goiás State, central Brazil. The plasmodia were white, round or ellipsoidal and measured 200-600 microm. Parasite development was asynchronous and the mature spores were fusiform and had smooth wall. The spores measurements were (range, with means+/-S.D. in parentheses): total length-48.4-53.1 microm (51.6+/-3.4 microm), body length-13.5-15.2 microm (14.2+/-0.8 microm), body width-5.1-6.1 microm (5.7+/-0.5 microm), body thickness-4.7-5.3 microm (4.9+/-0.2 microm) and caudal process length-38.0-41.2 microm (38.3+/-2.9 microm). The polar capsules were elongated and of unequal size, with lengths of 6.3-6.8 microm (6.5+/-0.2) and 6.2-6.6 microm (6.3+/-0.1) for the longest and shortest axes, respectively. Capsule width was 1.4-1.6 microm (1.5+/-0.1). Histological analysis showed that the plasmodia occurred in the tunica adventitia of the gall bladder and were delimited by a thin capsule of connective tissue. In the gill arch, the plasmodia were also surrounded by connective tissue similar to the endomesium of striated skeletal muscle cells. Sixty-five juvenile specimens of A. gigas weighing 1.0-25.0 kg were examined, 17 (26.1%) of which were infected. Of these, 14 (82.3%) had cysts in the gall bladder, two (11.7%) had cysts in the gill arch and only one (5.9%) had cysts in both organs. When the fish were grouped by weight, the prevalence of infection in fish weighing up to 10.0 kg (20.7%) was significantly lower than in fish weighing 10.1-25.0 kg (50%) (G=3.93; d.f.=1; p<0.05).

  13. 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.

  14. Ultrastructural study of spermiogenesis and the spermatozoon of Cavisoma magnum (Southwell, 1927) (Acanthocephala, Palaeacanthocephala, Cavisomidae), from Siganus lineatus (Pisces, Teleostei, Siganidae) (Valenciennes, 1835) in New Caledonia.

    PubMed

    Foata, J; Quilichini, Y; Justine, J-L; Bray, R A; Marchand, B

    2012-02-01

    This paper presents an ultrastructural study of Cavisoma magnum (Acanthocephala, Cavisomatidae) with a Transmission Electron Microscopy tool. This parasite of the fish Siganus lineatus is here reported for the first time from off New Caledonia, South Pacific. It is the first study describing the ultrastructure, spermiogenesis and spermatozoon of a species of the family Cavisomatidae. The young spermatid of C. magnum possesses a centriole constituted of doublets without a central element. After the elaboration of a flagellum of 9+2 pattern, the centriole migrates in a nuclear groove. Then the flagellum migration occurs and gives rise to a spermatozoon. The distribution and the size of the protein granules are reported and the posterior extremity appears like a chromatin lamina wave. Comparative ultrastructural data are presented on sperm and spermiogenesis of the Acanthocephala and Rotifers examined to date and the phylogenetic implications are discussed.

  15. 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.

  16. 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).

  17. Solearhynchus kostylewi (Meyer, 1932) comb. nov. (acanthocephala: Echinorhynchidae), a rare parasite of Solea solea (pisces: soleidae) in the Gemlik Bay, Sea of Marmara.

    PubMed

    Kvach, Y; Oğuz, M C

    2010-03-01

    Paracanthocephaloides kostylewi (Meyer, 1932), a rare parasite of the common sole Solea solea, previously placed in the Arhythmacanthidae, is transfered to the genus Solearhynchus de Buron & Maillard, 1985 of the family Echinorhynchidae as Solearhynchus kostylewi (Meyer, 1932) new comb., because its proboscis is armed by a single type of hooks, the posterior hook in each row is pinlike and with feebly developed root. The species is redescribed on the basis of newly collected material from the Gemlik Bay, Sea of Marmara. A key to the species of Solearhynchus is provided.

  18. Density of Trematocranus placodon (Pisces: Cichlidae): a predictor of density of the schistosome intermediate host, Bulinus nyassanus (Gastropoda: Planorbidae), in Lake Malaŵi.

    PubMed

    Madsen, Henry; Stauffer, Jay R

    2011-06-01

    From the mid-1980s, we recorded a significant increase in urinary schistosomiasis infection rate and transmission among inhabitants of lakeshore communities in the southern part of Lake Malaŵi, particularly on Nankumba peninsula in Mangochi District. We suggested that the increase was due to over-fishing, which reduced the density of snail-eating fishes, thereby allowing schistosome intermediate host snails to increase to higher densities. In this article, we collected data to test this hypothesis. The density of both Bulinus nyassanus, the intermediate host of Schistosoma haematobium, and Melanoides spp. was negatively related to density of Trematocranus placodon, the most common of the snail-eating fishes in the shallow water of Lake Malaŵi. Both these snails are consumed by T. placodon. Transmission of S. haematobium through B. nyassanus only occurs in the southern part of the lake and only at villages where high density of the intermediate host is found relatively close to the shore. Thus, we believe that implementation of an effective fish ban up to 100-m offshore along these specific shorelines in front of villages would allow populations of T. placodon to increase in density and this would lead to reduced density of B. nyassanus and possibly schistosome transmission. To reduce dependence on natural fish populations in the lake and still maintain a source of high quality food, culture of indigenous fishes may be a viable alternative.

  19. Genetic and Morphological Variation of the Forkbeard, Phycis phycis (Pisces, Phycidae): Evidence of Panmixia and Recent Population Expansion along Its Distribution Area

    PubMed Central

    Rodrigues, Ana Sofia B.; Sequeira, Vera; Neves, Ana; Paiva, Rafaela Barros

    2016-01-01

    The knowledge of population structure of a species is essential to effectively assess and manage fisheries. In the present study, genetics, by mitochondrial DNA cytochrome b sequence analysis, and body geometric morphometrics were used to evaluate the existence of distinct populations of the forkbeard (Phycis phycis), an important commercial species in several European countries, especially Portugal and Spain. For geometric morphometric analysis, specimens were collected in the Northeast Atlantic Ocean—Azores, Madeira and mainland Portugal, and for genetic analysis, these samples were complemented with samples collected in the Mediterranean Sea—Spain, Italy and Croatia, in order to cover the entire distribution area of the species. Body shape of the forkbeard from the Northeast Atlantic was found to be highly variable. This variation was probably associated with different environmental factors between the study areas. Despite morphological variation, a low genetic differentiation between samples from different areas was found, most likely due to gene flow that occurred in the past or with the demographic history of the species. Moreover, the presence of unique haplotypes in the Northeast Atlantic and in the Mediterranean suggests that recent gene flow between populations from these areas should be limited. Altogether, a high haplotype diversity, a low nucleotide diversity, a “star-like” network and the results of the mismatch distribution, indicate a possible signature of recent population expansions, which probably started during the end of the Last Glacial Maximum and led to the colonization of the Northeast Atlantic and the Mediterranean. PMID:27941988

  20. Infracommunity structure of parasites of Hemigymnus melapterus (Pisces: Labridae) from Lizard Island, Australia: the importance of habitat and parasite body size.

    PubMed

    Muñoz, Gabriela; Cribb, Thomas H

    2005-02-01

    This study describes the community of all metazoan parasites from 14 individuals of thicklip wrasse, Hemigymnus melapterus, from Lizard Island, Australia. All fish were parasitized, and 4,649 parasite individuals were found. Twenty-six parasite species were identified although only 6 species were abundant and prevalent: gnathiid isopods, the copepod Hatschekia hemigymni, the digenean Callohelmis pichelinae, and 3 morphotypes of tetraphyllidean cestode larvae. We analyzed whether the body size and microhabitat of the parasites and size of the host affected understanding of the structure of the parasite community. We related the abundance, biovolume, and density of parasites with the host body size and analyzed the abundances and volumetric densities of some parasite species within microhabitats. Although the 2 most abundant species comprised 75% of all parasite individuals, 4 species, each in similar proportion, comprised 85% of the total biovolume. Although larger host individuals had higher richness, abundance, and biovolume of parasites than smaller individuals, overall parasite volumetric density actually decreased with the host body size. Moreover, parasites exhibited abundances and densities significantly different among microhabitats; some parasite species depended on the area available, whereas others selected a specific microhabitat. Parasite and habitat size exhibited interesting relationships that should be considered more frequently. Considerations of these parameters improve understanding of parasite community structure and how the parasites use their habitats.

  1. Metazoan parasite infracommunities of Mycteroperca bonaci (Poey, 1960) (Pisces: Epinephelidae) in reef and coastal environments off the coast of Yucatán, México.

    PubMed

    Espínola-Novelo, Juan F; González-Salas, Carlos; Guillén-Hernández, Sergio; MacKenzie, Ken

    2015-09-01

    The black grouper Mycteroperca bonaci is a commercially important fish off the coast of Yucatan, Mexico. To investigate possible differences between parasite communities in two different environments, 60 fish were collected from two areas during 2010 and 2011 and examined for parasites. The fish were classified into two age groups, in each of which the parameters of parasitic infection - prevalence, abundance and intensity - were determined. Parasite faunas were further described at the infracommunity level. Using both univariate (PERMANOVA) and multivariate statistical methods, the values of richness, abundance, diversity and Brillouin evenness as well as the Index values of Bray-Curtis and Jaccard for similarity were calculated and compared. The results of these tests and of CAP discriminant analyses at the two sites showed the existence of two distinct parasite communities. The parasite taxa mainly responsible for the differences were the digeneans Dollfustrema sp., Prosorhynchus spp., Lepidapedoides epinepheli and Hamacreadium mutabile, and the nematode Philometra salgadoi. The potential for some of these parasites to be used as biological tags for stock identification of M. bonaci is discussed.

  2. 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.

  3. Three new species of Hatschekia Poche, 1902 (Copepoda: Siphonostomatoida: Hatschekiidae) parasitic on boxfishes (Pisces: Tetraodontiformes: Aracanidae and Ostraciidae) in Japanese waters.

    PubMed

    Uyeno, Daisuke; Nagasawa, Kazuya

    2010-02-01

    Three new species of Hatschekia Poche, 1902 are described from the gill filaments of three species of boxfishes captured off southern Japan: H. pseudostracii n. sp. on Kentrocapros aculeatus (Houttuyn) (Aracanidae); H. bibullae n. sp. on Lactoria diaphana (Bloch & Schneider) (Ostraciidae); and H. kuroshioensis n. sp. on Tetrosomus concatenates (Bloch) (Ostraciidae). Of the 93 currently valid species in the genus, these new species differ from the 87 species which lack four stout processes on the posterior margin of the intercoxal sclerites of legs 1 and 2. Those processes are present on the remaining six species and the three new species. Of these nine species, H. pseudostracii n. sp. is distinguished by having a T-shaped chitinous frame on the cephalothorax, the leg 1 exopod twice as long as the endopod and a small parabasal papilla. H. bibullae n. sp. can be differentiated by a combination of morphological features as follows: a well-developed, thumb-shaped parabasal papilla, the leg 1 exopod twice as long as the endopod and a trunk lacking posterior lobes. H. kuroshioensis n. sp. can be recognised by bearing a T-shaped chitinous frame on the cephalothorax, the leg 1 exopod is three times as long as the endopod and the trunk lacks posterior lobes.

  4. A new species of parasitic copepod of the genus Hatschekia Poche, 1902 (Siphonostomatoida: Hatschekiidae) from filefishes (Pisces: Tetraodontiformes: Monacanthidae) from off Okinawa, Japan.

    PubMed

    Uyeno, Daisuke; Nagasawa, Kazuya

    2010-05-01

    Hatschekia khahajya n. sp. is described from the gill filaments of two monacanthid fishes, Cantherhines dumerilii (Hollard) and Amanses scopes (Cuvier), caught off Okinawa, Japan. The new species can be distinguished from its congeners by the possession of the following combination of characters: cephalothorax length/trunk length ratio greater than 0.40; cephalothorax with a pair of lateral bars on the chitinous ring and a posterior pair of surface ridges; trunk with a bifurcate chitinous frame extending over its anterior third and with well-developed posterior lobes that extend beyond the abdomen; and four processes plus two spinular rows on the distal margin of the intercoxal sclerite of legs 1 and 2.

  5. Climate change and oceanic barriers: genetic differentiation in Pomatomus saltatrix (Pisces: Pomatomidae) in the North Atlantic Ocean and the Mediterranean Sea.

    PubMed

    Pardiñas, A F; Campo, D; Pola, I G; Miralles, L; Juanes, F; Garcia-Vazquez, E

    2010-11-01

    Nucleotide variation of partial cytochrome b sequences was analysed in the bluefish Pomatomus saltatrix to investigate the population-structuring roles of climate change and oceanic barriers. Western and eastern North Atlantic Ocean populations appeared to be totally isolated, with the latter connected to the Mediterranean Sea within which further structuring occurred.

  6. Changes in Glutathione S-Transferase Activity and Parental Care Patterns in a Catfish (Pisces, Ariidae) as a Biomarker of Anthropogenic Impact in a Brazilian Harbor.

    PubMed

    Fortes Carvalho Neta, Raimunda Nonata; Barbosa, Gleyciane Lobato; Torres, Hetty Salvino; Pinheiro Sousa, Débora Batista; Castro, Jonatas da Silva; Santos, Débora Martins Silva; Tchaicka, Lígia; Almeida, Zafira da Silva de; Teixeira, Erivania Gomes; Torres, Audalio Rebelo

    2017-01-01

    Catfish have been used as a model system for studying biochemical mechanisms of biotransformation. The main goal of this study was to identify alterations in hepatic glutathione S-transferase (GST) activity and changes in the parental care pattern of a mouth-brooding catfish, Sciades herzbergii, as a biomarker of anthropogenic impact in a port area on the northeastern coast of Brazil. The fish were sampled from a natural reserve (A1 = reference site) and from an industrialized port area (A2 = impacted site). Two analyses were carried out: hepatic GST activity and mouth-brooding behavior of males. Catfish collected from the A1 site displayed all stages of gonadal maturation, and some of the adult males were mouth brooding 12-30 embryos. Not all gonadal maturation stages of the catfish were represented at the A2 site, and no mouth-brooding males were observed. GST activity in the liver of S. herzbergii was significantly higher in fish from the impacted site compared with fish from the reference site. Values for the enzymatic activity increased progressively in fish sampled from the reserve area as they became more reproductively mature (immature ≤ maturing ≤ mature ≤ spent). However, the greatest values for GST activity (2.84 ± 0.31 μmol min(-1) mg protein(-1)) among fish sampled from the impacted area were found in (immature) juveniles. These data suggest that changes in hepatic GST activity and mouth-brooding behavior of S. herzbergii can be used as biomarkers of anthropogenic impact.

  7. 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.

  8. [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.

  9. Effects of nickel chloride and oxygen depletion on behaviour and vitality of zebrafish (Danio rerio, Hamilton, 1822) (Pisces, Cypriniformes) embryos and larvae.

    PubMed

    Kienle, Cornelia; Köhler, H-R; Filser, Juliane; Gerhardt, Almut

    2008-04-01

    We examined acute (2 h exposure of 5-day-old larvae) and subchronic (exposure from fertilization up to an age of 11 days) effects of NiCl(2).6H2O on embryos and larvae of zebrafish (Danio rerio), both alone and in combination with oxygen depletion. The following endpoints were recorded: acute exposure: locomotory activity and survival; subchronic exposure: hatching rate, deformations, locomotory activity (at 5, 8 and 11 days) and mortality. In acute exposures nickel chloride (7.5-15 mg Ni/L) caused decreasing locomotory activity. Oxygen depletion (or=10 mg Ni/L resulted in delayed hatching at an age of 96 h, in decreased locomotory activity at an age of 5 days, and increased mortality at an age of 11 days (LC20=9.5 mg Ni/L). The observed LOEC for locomotory activity (7.5 mg Ni/L) is in the range of environmentally relevant concentrations. Since locomotory activity was already affected by acute exposure, this parameter is recommended to supplement commonly recorded endpoints of toxicity.

  10. 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.

  11. 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

    2013-03-14

    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.

  12. 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.

  13. Discovery and Development of Therapeutic Drugs against Lethal Human RNA- Viruses: A Multidisciplinary Assault

    DTIC Science & Technology

    1990-02-20

    Coelenterata PT 1.90 Pre 11/14/89 B721743 M-3314 Australia.78 Coelenterata PT 2.18 Pre 11/14/89 B721749 6584 M-3328 Australia.78 Chordata /Tunicata PT 1.67 Pre...PT 13.99 Pre 10/31/89 B721880 6589 M-3160 Palau.79 Chordata /Pisces PT 1.02 Pre 10/31/89 B721892 6590 M-3163 Palau.79 Chordara/Pisces YF 10.52 Pre 01...02/90 B721899 6591 M-3163 Palau.79 Chordaca/Pisces PT 5.84 Pre 01/02/90 of 6591 M-3165 Palau.79 Chordata /Pisces PT 5.56 Pre 01/02/90 B721905 6592 M

  14. 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.

  15. Chewing lice of the genus Myrsidea waterston (Phthiraptera: Menoponidae) from the emberizidae and thraupidae (Passeriformes) in Mato Grosso do Sul, Brazil.

    PubMed

    Sychra, Oldrich; Literak, Ivan; Capek, Miroslav

    2009-01-01

    This paper presents the first record of three chewing lice species of the genus Myrsidea collected from one emberizid and two thraupid hosts in Mato Grosso do Sul, Brazil. Morphological characters of M. seminuda are added for the last redescription of this species and a new key to males of 'bonariensis species group' is presented.

  16. Relocation of the 146th Tactical Airlift Wing of the California Air National Guard. Volume 2. Appendices

    DTIC Science & Technology

    1985-08-01

    Mulefat Cirsium vul=e Bull thistle Conyza bonariensis Flax-leaved fleabane3 Picris e-hioides Bristly ox tongue BORAGINACEAE - BORAGE FAMILY...Boraginaccae - Borage Family Amsinkia tessellata Interior Fiddleneck U ~Pectocarya penicillataI Winged Pectocarya Brassicaceae - Mustard Family

  17. 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.

  18. 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

    2016-04-07

    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.

  19. The influence of history and contemporary stream hydrology on the evolution of genetic diversity within species: an examination of microsatellite DNA variation in bull trout, Salvelinus confluentus (Pisces: Salmonidae).

    PubMed

    Costello, A B; Down, T E; Pollard, S M; Pacas, C J; Taylor, E B

    2003-02-01

    An understanding of the relative roles of historical and contemporary factors in structuring genetic variation is a fundamental, but understudied aspect of geographic variation. We examined geographic variation in microsatellite DNA allele frequencies in bull trout (Salvelinus confluentus, Salmonidae) to test hypotheses concerning the relative roles of postglacial dispersal (historical) and current landscape features (contemporary) in structuring genetic variability and population differentiation. Bull trout exhibit relatively low intrapopulation microsatellite variation (average of 1.9 alleles per locus, average He = 0.24), but high levels of interpopulation divergence (F(ST) = 0.39). We found evidence of historical influences on microsatellite variation in the form of a decrease in the number of alleles and heterozygosities in populations on the periphery of the range relative to populations closer to putative glacial refugia. In addition, one region of British Columbia that was colonized later during deglaciation and by more indirect watershed connections showed less developed and more variable patterns of isolation by distance than a similar region colonized earlier and more directly from refugia. Current spatial and drainage interconnectedness among sites and the presence of migration barriers (falls and cascades) within individual streams were found to be important contemporary factors influencing historical patterns of genetic variability and interpopulation divergence. Our work illustrates the limited utility of equilibrium models to delineate population structure and patterns of genetic diversity in recently founded populations or those inhabiting highly heterogeneous environments, and it highlights the need for approaches incorporating a landscape context for population divergence. Substantial microsatellite DNA divergence among bull trout populations may also signal divergence in traits important to population persistence in specific environments.

  20. Heterobothrium lineatus (Monogenea: Diclidophoridae) infecting the gills of the Nile puffer Tetraodon lineatus (Pisces: Tetraodontidae) from the River Nile, Egypt with a new localit record: a light and scanning electron microscopic study.

    PubMed

    Morsy, Kareem S; Khalil, Mona Fathi; Gamil, Irene Sameh; Elebiarie, Ahmed Salem; Ibrahim, Rokia Mahmoud

    2013-12-01

    Heterobothrium lineatus (Monogenea: Diclidophoridae) is described from the gills of Tetraodon lineatus collected from the River Nile at Helwan governorate, Egypt as a new locality record. The morphology and morphometric characterization of the recovered worms were described by means of light and scanning electron microscopy. Twenty two out 35 with a percentage of 62.9% of the examined fish were infected with Heterobothrium sp. (the intensity of infection was about ten worms per fish in general). Most of the infected fish had very pale gills and showed symptoms of anemia. Morphologically, the adult worms were elongated with anterior pointed and posterior broad ends, it measured 1.15-1.76 (1.52 +/- 0.02) mm in length x 0.28-0.39 (0.29 +/- 0.02) mm in width. Two buccal organs situated anteriorly around mouth opening were shown by light and scanning electron microscopy. Haptor subdivided into four pairs of clamps without isthmus separating it from body. The recovered worm differed from the previously species in the same genus by small dimensions of the measurements and presence of a copulatory organ armed with 7-11 genital hooks. Also, it is distinguished from H. tetrodonis and H. okamotoi by absence of a distinct isthmus, and resembled H. lamothei from gills of Sphoeroides testodineus in Mexico and H. lineatus from T. lineatus in Egypt in general appearance and presence of rectangular haptor with the fourth pair of clamps smaller than the previous ones.

  1. Real-time polymerase chain reaction, in situ hybridization and immunohistochemical localization of insulin-like growth factor-I and myostatin during development of Dicentrarchus labrax (Pisces: Osteichthyes).

    PubMed

    Patruno, Marco; Sivieri, Susanna; Poltronieri, Carlo; Sacchetto, Roberta; Maccatrozzo, Lisa; Martinello, Tiziana; Funkenstein, Bruria; Radaelli, Giuseppe

    2008-03-01

    The distribution of insulin-like growth factor-I (IGF-I) and myostatin (MSTN) was investigated in sea bass (Dicentrarchus labrax) by real-time polymerase chain reaction (PCR), in situ hybridization (ISH) and immunohistochemistry. Real-time PCR indicated that IGF-I mRNA increased from the second day post-hatching and that this trend became significant from day 4. ISH confirmed a strong IGF-I mRNA expression from the first week post-hatching, with the most abundant expression being detected in the liver of larvae and adults. Real-time PCR also showed that the level of MSTN mRNA increased significantly from day 25. The expression of MSTN mRNA was higher in muscle and almost absent in other anatomical regions in both larvae and adults. Interestingly, the lateral muscle showed a quantitative differential expression of IGF-I and MSTN mRNAs in red and white muscle, depending on the developmental stage examined. IGF-I immunoreactivity was detected in developing intestine at hatching and in skeletal muscle, skin and yolk sac. MSTN immunostaining was evident in several tissues and organs in both larvae and adults. Both IGF-I and MSTN proteins were detected in the liver from day 4 post-hatching and, subsequently, in the kidney and heart muscle from day 10. Our results suggest, on the basis of a combined methodological approach, that IGF-I and MSTN are involved in the regulation of somatic growth in the sea bass.

  2. 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.

  3. The influence of food competition and host specificity on the transmission of Triaenophorus crassus (Cestoda) and Cystidicola farionis (Nematoda) to Coregonus lavaretus and Coregonus albula (Pisces:Coregonidae) in Finland.

    PubMed

    Pulkkinen, K; Valtonen, E T; Niemi, A; Poikola, K

    1999-11-01

    As a superior competitor for planktonic food, vendace (Coregonus albula), when abundant, is expected to displace whitefish (Coregonus lavaretus) from feeding on plankton and to force it to rely more on benthic food. The predicted result would be a reduced abundance of the copepod-transmitted cestode Triaenophorus crassus in whitefish, but an increase in the abundance of the nematode Cystidicola farionis transmitted via benthic amphipods. We studied the occurrence of both parasites in whitefish during 1991-1996 in three interconnected areas at Lake Saimaa, Finland, where the densities of the vendace stocks varied due to natural fluctuation in year-class strengths. In accordance with our hypothesis, some indication of the effect of the density of the vendace population on abundance of C. farionis infection in whitefish was found, but not in the case of T. crassus. Only 0.2% of vendace were infected with T. crassus, while up to 100% of the whitefish in the yearly samples harboured the parasite. In further experiments we clarified which copepod species in Lake Saimaa act as first intermediate hosts of T. crassus, and verified from stomach samples the exposure of both whitefish and vendace to those species. Experimental infections indicated that the infectivity of T. crassus is lower for vendace than for whitefish. We suggest that the reason why vendace stock density does not affect T. crassus infection in whitefish is that T. crassus is transmitted in littoral areas during a short period in spring. At that time of the year copepods are abundant and available to both whitefish and vendace, but since the parasite is less infective to vendace. they do not become infected. At other times of the year, dense vendace stocks may force whitefish to shift to benthic food, which includes amphipods transmitting C. farionis. During vendace stock decline, whitefish may, however, continue to feed on plankton and avoid exposure to C. farionis.

  4. Migration of the curimbatá Prochilodus lineatus (Valenciennes, 1836) (Pisces, Prochilodontidae) at the waterfall "Cachoeira de Emas" of the Mogi-Guaçu river--São Paulo, Brazil.

    PubMed

    Capeleti, A R; Petrere, M

    2006-05-01

    In this paper, we counted the ascending curimbatás at the fish ladder at the Cachoeira de Emas from October, 1992 to September, 1993 in one whole day (24 h period) per month at different observation points in the dam for 5 min every hour. Most of the fish (80%) were counted not in the fish ladder itself, but in two adjacent spillways at its left, perhaps due to the comparatively increased flow as they are narrower than the ladder. The bulk of the migration occurred in September/October. We inspected the degree of injury of the fish in order to examine the hypothesis that larger fish are less injured, however no conclusion was reached. The degree of injury varied between different points and in different months of the year.

  5. Local host adaptation and use of a novel host in the seed beetle Megacerus eulophus.

    PubMed

    Stotz, Gisela C; Suárez, Lorena H; Gonzáles, Wilfredo L; Gianoli, Ernesto

    2013-01-01

    Spatial variation in host plant availability may lead to specialization in host use and local host adaptation in herbivorous insects, which may involve a cost in performance on other hosts. We studied two geographically separated populations of the seed beetle Megacerus eulophus (Coleoptera: Bruchidae) in central Chile: a population from the host Convolvulus chilensis (in Aucó) and a population from C. bonariensis (in Algarrobo). In Aucó C. chilensis is the only host plant, while in Algarrobo both C. bonariensis and C. chilensis are available. We tested local adaptation to these native host plants and its influence on the use of another, exotic host plant. We hypothesized that local adaptation would be verified, particularly for the one-host population (Aucó), and that the Aucó population would be less able to use an alternative, high-quality host. We found evidence of local adaptation in the population from C. chilensis. Thus, when reared on C. chilensis, adults from the C. chilensis population were larger and lived longer than individuals from the C. bonariensis population, while bruchids from the two populations had the same body size and longevity when reared on C. bonariensis. Overall, bruchids from the C. chilensis population showed greater performance traits than those from the C. bonariensis population. There were no differences between the bruchid populations in their ability to use the alternative, exotic host Calystegia sepium, as shown by body size and longevity patterns. Results suggest that differences in local adaptation might be explained by differential host availability in the study populations.

  6. Local Host Adaptation and Use of a Novel Host in the Seed Beetle Megacerus eulophus

    PubMed Central

    Stotz, Gisela C.; Suárez, Lorena H.; Gonzáles, Wilfredo L.; Gianoli, Ernesto

    2013-01-01

    Spatial variation in host plant availability may lead to specialization in host use and local host adaptation in herbivorous insects, which may involve a cost in performance on other hosts. We studied two geographically separated populations of the seed beetle Megacerus eulophus (Coleoptera: Bruchidae) in central Chile: a population from the host Convolvulus chilensis (in Aucó) and a population from C. bonariensis (in Algarrobo). In Aucó C. chilensis is the only host plant, while in Algarrobo both C. bonariensis and C. chilensis are available. We tested local adaptation to these native host plants and its influence on the use of another, exotic host plant. We hypothesized that local adaptation would be verified, particularly for the one-host population (Aucó), and that the Aucó population would be less able to use an alternative, high-quality host. We found evidence of local adaptation in the population from C. chilensis. Thus, when reared on C. chilensis, adults from the C. chilensis population were larger and lived longer than individuals from the C. bonariensis population, while bruchids from the two populations had the same body size and longevity when reared on C. bonariensis. Overall, bruchids from the C. chilensis population showed greater performance traits than those from the C. bonariensis population. There were no differences between the bruchid populations in their ability to use the alternative, exotic host Calystegia sepium, as shown by body size and longevity patterns. Results suggest that differences in local adaptation might be explained by differential host availability in the study populations. PMID:23326528

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

    USGS Publications Warehouse

    Selkowitz, David J.; Forster, Richard R.

    2016-01-01

    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.

  8. 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.

  9. A New Species of Paracoccus Ezzat and McConnell (Hemiptera: Pseudococcidae) from Southern Brazil.

    PubMed

    Pacheco da Silva, V C; Kaydan, M B; Germain, J-F; Botton, M

    2016-12-01

    The worldwide mealybug genus Paracoccus Ezzat & McConnell (Hemiptera: Coccomorpha: Pseudococcidae) has eight described Neotropical species, including two species known from Brazil. In this article, we describe a third species from Brazil: Paracoccus galzerae Pacheco da Silva & Kaydan sp. n., based on the morphology of adult females collected on the roots of Conyza bonariensis (Asteraceae) in vineyards in Bento Gonçalves City, Rio Grande do Sul. A revised identification key including the new species is provided for the Neotropical region.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Computer modeling of complete IC fabrication process

    NASA Astrophysics Data System (ADS)

    Dutton, Robert W.

    1987-05-01

    The development of fundamental algorithms for process and device modeling as well as novel integration of the tools for advanced Integrated Circuit (IC) technology design is discussed. The development of the first complete 2D process simulator, SUPREM 4, is reported. The algorithms are discussed as well as application to local-oxidation and extrinsic diffusion conditions which occur in CMOS AND BiCMOS technologies. The evolution of 1D (SEDAN) and 2D (PISCES) device analysis is discussed. The application of SEDAN to a variety of non-silicon technologies (GaAs and HgCdTe) are considered. A new multi-window analysis capability for PISCES which exploits Monte Carlo analysis of hot carriers has been demonstrated and used to characterize a variety of silicon MOSFET and GaAs MESFET effects. A parallel computer implementation of PISCES has been achieved using a Hypercube architecture. The PISCES program has been used for a range of important device studies including: latchup, analog switch analysis, MOSFET capacitance studies and bipolar transient device for ECL gates. The program is broadly applicable to RAM and BiCMOS technology analysis and design. In the analog switch technology area this research effort has produced a variety of important modeling and advances.

  15. 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.

  16. [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.

  17. 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

  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. Biology and management of two important Conyza weeds: a global review.

    PubMed

    Bajwa, Ali Ahsan; Sadia, Sehrish; Ali, Hafiz Haider; Jabran, Khawar; Peerzada, Arslan Masood; Chauhan, Bhagirath Singh

    2016-12-01

    Weed management is one of the prime concerns for sustainable crop production. Conyza bonariensis and Conyza canadensis are two of the most problematic, noxious, invasive and widespread weeds in modern-day agriculture. The biology, ecology and interference of C. bonariensis and C. canadensis have been reviewed here to highlight pragmatic management options. Both these species share a unique set of biological features, which enables them to invade and adapt a wide range of environmental conditions. Distinct reproductive biology and an efficient seed dispersal mechanism help these species to spread rapidly. Ability to interfere strongly and to host crop pests makes these two species worst weeds of cropping systems. These weed species cause 28-68 % yield loss in important field crops such as soybean and cotton every year. These weeds are more prevalent in no-till systems and, thus, becoming a major issue in conservation agriculture. Cultural practices such as crop rotations, seed rate manipulation, mulching, inter-row tillage and narrow row spacing may provide an effective control of these species. However, such methods are not feasible and applicable under all types of conditions. Different herbicides also provide a varying degree of control depending on crop, agronomic practices, herbicide dose, application time and season. However, both these species have evolved resistance against multiple herbicides, including glyphosate and paraquat. The use of alternative herbicides and integrated management strategies may provide better control of herbicide-resistant C. bonariensis and C. canadensis. Management plans based on the eco-biological interactions of these species may prove sustainable in the future.

  20. 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.

  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. Freshwater plants synthesize sulfated polysaccharides: heterogalactans from Water Hyacinth (Eicchornia crassipes).

    PubMed

    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.

  3. Synthesis of 'cineole cassette' monoterpenes in Nicotiana section Alatae: gene isolation, expression, functional characterization and phylogenetic analysis.

    PubMed

    Fähnrich, Anke; Brosemann, Anne; Teske, Laura; Neumann, Madeleine; Piechulla, Birgit

    2012-08-01

    The scent bouquets of flowers of Nicotiana species, particularly those of section Alatae, are rich in monoterpenes, including 1,8-cineole, limonene, β-myrcene, α- and β-pinene, sabinene, and α-terpineol. New terpene synthase genes were isolated from flowers of Nicotiana bonariensis, N. forgetiana, N. longiflora, and N. mutabilis. The recombinant enzymes synthesize simultaneously the characteristic 'cineole cassette' monoterpenes with 1,8-cineole as the dominant volatile product. Interestingly, amino acid sequence comparison and phylogenetic tree construction clustered the newly isolated cineole synthases (CIN) of section Alatae together with the catalytically similar CIN of N. suaveolens of section Suaveolentes, thus suggesting a common ancestor. These CIN genes of N. bonariensis, N. forgetiana, N. longiflora, and N. mutabilis are distinct from the terpineol synthases (TERs) of the taxonomically related N. alata and N. langsdorfii (both Alatae), thus indicating gene diversification of monoterpene synthases in section Alatae. Furthermore, the presence of CINs in species of the American section Alatae supports the hypothesis that one parent of the Australian section Suaveolentes was a member of the present section Alatae. Amino acid sequences of the Nicotiana CINs and TERs were compared to identify relevant amino acids of the cyclization reaction from α-terpineol to 1,8-cineole.

  4. Case Studies of Software Development Tools for Parallel Architectures

    DTIC Science & Technology

    1993-06-01

    RL-TR-93-114 Final Technical Report AD-A269 193I M N11 Nal I U l iE rr ll Hllll CASE STUDIES OF SOFTWARE DEVELOPMENT TOOLS FOR PARALLEL ARCHITECTURES...65 Om ega/ PegaSys ..................................................................................... 66 PARET...Pisces Rn BALSA II TANGO PARET VMMP Omega/ PegaSys PSG POKER ISSOS Unity -4- PADWB Schedule Tool Degn Graph= Alg I/gr- Sol Pormbil- Ptform Pan/don Debug

  5. 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....

  6. 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...

  7. Science Update on the Hawaii Undersea Research Lab's Deep Submergence Operations in 2006 and Beyond

    NASA Astrophysics Data System (ADS)

    Smith, J. R.; Wiltshire, J. C.; Orange, R. S.

    2006-12-01

    The Hawaii Undersea Research Laboratory (HURL), the NOAA Undersea Research Program (NURP) Center for Hawaii and the Western Pacific, is one of six regional NURP Centers specializing in providing scientists with the tools and expertise they need to investigate the undersea environment, including HOVs, ROVs, and other cutting edge technologies. Established at the University of Hawaii 26 years ago, 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 HOV, an RCV-150 900-meter ROV, and multibeam equipped support ship R/V Ka`imikai-o-Kanaloa (KoK) have been continuously upgraded and adapted to carry out cutting edge scientific expeditions. Following a successful far ranging five month program to the South Pacific in 2005, a complete overhaul for Pisces IV was carried out in the first half of 2006 with science dives in the main Hawaiian Islands taking place from August to December. Sixty Pisces dives are being performed for over 25 principal investigators and senior scientists in 10 projects. These projects include studies of deep-water benthic algae, the ecology of submarine canyons, paleo-sea level study, explosive volcanism on Loihi Seamount, drowned reefs off the northeastern coast of the Big Island of Hawaii, followed by several dive series with multiple biological, reef, and fisheries PIs working off Oahu, Molokai, Maui, and Lanai on bottomfish, artificial reef, precious coral, and invasive species assessments. Complete overhaul of Pisces V will be done in 2007, after which a fall program in the newly designated Northwestern Hawaiian Islands Marine National Monument is expected. Following that, preparations will begin in earnest for the FY 2008 expedition to the North Pacific. This expedition is anticipated to be six months in length and involve over 80 HOV dives. It will cover the Northwestern Hawaiian Islands, Emperor Seamounts, and the coasts of

  8. 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

  9. Fish with thermolabile sex determination (TSD) as models to study brain sex differentiation.

    PubMed

    Blázquez, Mercedes; Somoza, Gustavo M

    2010-05-01

    As fish are ectothermic animals, water temperature can affect their basic biological processes such as larval development, growth and reproduction. Similar to reptiles, the incubation temperature during early phases of development is capable to modify sex ratios in a large number of fish species. This phenomenon, known as thermolabile sex determination (TSD) was first reported in Menidia menidia, a species belonging to the family Atherinopsidae. Since then, an increasing number of fish have also been found to exhibit TSD. Traditionally, likewise in reptiles, several TSD patterns have been described in fish, however it has been recently postulated that only one, females at low temperatures and males at high temperatures, may represent the "real" or "true" TSD. Many studies regarding the influence of temperature on the final sex ratios have been focused on the expression and activity of gonadal aromatase, the enzyme involved in the conversion of androgens into estrogens and encoded by the cyp19a1a gene. In this regard, teleost fish, may be due to a whole genome duplication event, produce another aromatase enzyme, commonly named brain aromatase, encoded by the cyp19a1b gene. Contrary to what has been described in other vertebrates, fish exhibit very high levels of aromatase activity in the brain and therefore they synthesize high amounts of neuroestrogens. However, its biological significance is still not understood. In addition, the mechanism whereby temperature can induce the development of a testis or an ovary still remains elusive. In this context the present review is aimed to discuss several theories about the possible role of brain aromatase using fish as models. The relevance of brain aromatase and therefore of neuroestrogens as the possible cue for gonadal differentiation is raised. In addition, the possible role of brain aromatase as the way to keep the high levels of neurogenesis in fish is also considered. Several key examples of how teleosts and aromatase

  10. Discrimination of three Pegaga (Centella) varieties and determination of growth-lighting effects on metabolites content based on the chemometry of 1H nuclear magnetic resonance spectroscopy.

    PubMed

    H, Maulidiani; Khatib, Alfi; Shaari, Khozirah; Abas, Faridah; Shitan, Mahendran; Kneer, Ralf; Neto, Victor; Lajis, Nordin H

    2012-01-11

    The metabolites of three species of Apiaceae, also known as Pegaga, were analyzed utilizing (1)H NMR spectroscopy and multivariate data analysis. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) resolved the species, Centella asiatica, Hydrocotyle bonariensis, and Hydrocotyle sibthorpioides, into three clusters. The saponins, asiaticoside and madecassoside, along with chlorogenic acids were the metabolites that contributed most to the separation. Furthermore, the effects of growth-lighting condition to metabolite contents were also investigated. The extracts of C. asiatica grown in full-day light exposure exhibited a stronger radical scavenging activity and contained more triterpenes (asiaticoside and madecassoside), flavonoids, and chlorogenic acids as compared to plants grown in 50% shade. This study established the potential of using a combination of (1)H NMR spectroscopy and multivariate data analyses in differentiating three closely related species and the effects of growth lighting, based on their metabolite contents and identification of the markers contributing to their differences.

  11. [Pteridophytes that indicate environmental alteration in the temperate forest of San Jerónimo Amanalco, Texcoco, Mexico].

    PubMed

    Lucía Rodríguez, Romero; Pacheco, Leticia; Zavala Hurtado, José Alejandro

    2008-06-01

    Pteridophytes that indicate environmental alteration in the San Jer6nimo Amanalco temperate forest, Texcoco, Mexico. The patterns of distribution of 26 pteridophyte species were studied as possible indicators of environmental alteration in the temperate forest of San Jer6nimo Amanalco, Texcoco, State of Mexico. The presence and abundance of the pteridoflora was studied in relation to edaphic, topographic and vegetation variables in 100 sampling locations within an area of 494 hectares. The relationship between these variables was studied using Canonical Correspondence Analysis. Five landscapes were recognized in the study zone according to the degree of deterioration: severe erosion, erosion, mountain with moderate reversible deterioration, mountain with no evident deterioration, and canyon with no evident deterioration. Cheilanthes bonariensis and Pellaea ternifolia are indicators of environmental degradation. The taxa that only grow in landscapes without apparent alteration are Adiantum andicola, Adiantum poiretii, Argyrochosma incana, Asplenium blepharophorum, Dryopteris pseudo filix-mas, Equisetum hyemale and Pteris cretica.

  12. A survey of resistance to Tomato bushy stunt virus in the genus Nicotiana reveals that the hypersensitive response is triggered by one of three different viral proteins.

    PubMed

    Angel, Carlos A; Schoelz, James E

    2013-02-01

    In this study, we screened 22 Nicotiana spp. for resistance to the tombusviruses Tomato bushy stunt virus (TBSV), Cucumber necrosis virus, and Cymbidium ringspot virus. Eighteen species were resistant, and resistance was manifested in at least two different categories. In all, 13 species responded with a hypersensitive response (HR)-type resistance, whereas another five were resistant but either had no visible response or responded with chlorotic lesions rather than necrotic lesions. Three different TBSV proteins were found to trigger HR in Nicotiana spp. in an agroinfiltration assay. The most common avirulence (avr) determinant was the TBSV coat protein P41, a protein that had not been previously recognized as an avr determinant. A mutational analysis confirmed that the coat protein rather than the viral RNA sequence was responsible for triggering HR, and it triggered HR in six species in the Alatae section. The TBSV P22 movement protein triggered HR in two species in section Undulatae (Nicotiana glutinosa and N. edwardsonii) and one species in section Alatae (N. forgetiana). The TBSV P19 RNA silencing suppressor protein triggered HR in sections Sylvestres (N. sylvestris), Nicotiana (N. tabacum), and Alatae (N. bonariensis). In general, Nicotiana spp. were capable of recognizing only one tombusvirus avirulence determinant, with the exceptions of N. bonariensis and N. forgetiana, which were each able to recognize P41, as well as P19 and P22, respectively. Agroinfiltration failed to detect the TBSV avr determinants responsible for triggering HR in N. arentsii, N. undulata, and N. rustica. This study illustrates the breadth and variety of resistance responses to tombusviruses that exists in the Nicotiana genus.

  13. 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.

  14. 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.

  15. 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.

  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. The activation of the rat insulin gene II by BETA2 and PDX-1 in rat insulinoma cells is repressed by Pax6.

    PubMed

    Wolf, Gabriele; Hessabi, Behnam; Karkour, Anke; Henrion, Ulrike; Dahlhaus, Meike; Ostmann, Annett; Giese, Bernd; Fraunholz, Martin; Grabarczyk, Piotr; Jack, Robert; Walther, Reinhard

    2010-12-01

    The transcriptional transactivator Pax6 binds the pancreatic islet cell-specific enhancer sequence (PISCES) of the rat insulin I gene. However the human, mouse, and rat insulin gene II promoters do not contain a PISCES element. To analyze the role of Pax6 in those PISCES-less promoters, we investigated its influence on rat insulin gene II expression and included in our studies the main activators: pancreatic and duodenal homeobox protein-1 (PDX-1) and BETA2/E47. Luciferase assays, Northern blots, and RIA were used to study effects of Pax6 overexpression, gel shift and chromatin precipitation assays to study its binding to the DNA, and yeast two-hybrid assays and glutathione S transferase capture assays to investigate its interactions with PDX-1 and BETA2. Finally, glucose-dependent intracellular transport of Pax6 was demonstrated by fluorescence microscopy. Overexpression of Pax6 prevents activation of the rat insulin II gene by BETA2 and PDX-1 and hence suppresses insulin synthesis and secretion. In vitro, Pax6 binds to the A-boxes, thereby blocking binding of PDX-1, and at the same time, its paired domain interacts with BETA2. Fluorescence microscopy demonstrated that the nuclear-cytoplasmic localization of Pax6 and PDX-1 are oppositely regulated by glucose. From the results, it is suggested that at low concentrations of glucose, Pax6 is localized in the nucleus and prevents the activation of the insulin gene by occupying the PDX-1 binding site and by interacting with BETA2.

  18. 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

  19. MoonRIDERS: NASA and Hawaiis Innovative Lunar Surface Flight Experiment for Landing in Late 2017

    NASA Technical Reports Server (NTRS)

    Kelso, R. M.; Romo, R.; Mackey, P. J.; Phillips, J. R., III; Cox, R. E.; Hogue, M. D.; Calle, C. I.

    2016-01-01

    Recently, NASA Kennedy Space Center, Hawaii's state aerospace agency PISCES, and two Hawaii high schools Iolani and Kealakehe have come together in a unique collaboration called MoonRIDERS. This strategic partnership will allow Hawaii students to participate directly in sending a science experiment to the surface of the moon. The MoonRIDERS project started in the spring of 2014, with each institution responsible for its own project costs and activities. PISCES, given its legislative direction in advancing planetary surface systems, saw this collaboration as an important opportunity to inspire a young generation and encourage STEM (Science, Technology, Engineering, and Mathematics) learning. Under the guidance of PISCES and NASA, the students will be involved hands-on from start to finish in the engineering, testing, and validation of a space technology called the Electrodynamic Dust Shield (EDS). Dust is a critical issue for space exploration, as evidenced by the Apollo lunar missions and Mars rovers and landers. Dust creates a number of problems for humans and hardware, including inhalation, mechanical interference, wear and tear on spacesuits, inhibition of heat transfer on radiators, and reduced efficiency of solar panels. To address this, the EDS is designed to work on a variety of materials, and functions by generatingelectrodynamic fields to clear away the dust. The Google Lunar XPRIZE (GLXP), a space competition "designed to inspire pioneers to do robotic space transport on a budget," serves as a likely method for the MoonRIDERS to get their project to the moon. The EDS would potentially be flown as a hosted payload on a competitor's lander (still to be chosen). This briefing will provide an overview of the technology, the unique partnership, progress update and testing leading to this flight opportunity.

  20. [Structure of fish serum albumins].

    PubMed

    Andreeva, A M

    2010-01-01

    Data are presented about the presence of serum albumins in fishes of different classes and orders inhabiting different ecological conditions, about structure of typical albumins and albumin-like proteins, and about the degree of homology of these proteins to mammalian albumins. There is shown a wide spectrum of structural diversity of albumins in Pisces due to their participation in osmotic, plastic, and transport functions under conditions of environment and of the organism internal media. Detection of similar motifs in the piscine and mammalian albumin genes allows uniting these genes into one superfamily and considering vertebrate albumins the homologous proteins.

  1. 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.

  2. Neuroprotective effects of prior exposure to enriched environment on cerebral ischemia/reperfusion injury in rats: the possible molecular mechanism.

    PubMed

    Yu, Kewei; Wu, Yi; Hu, Yongshan; Zhang, Qi; Xie, Hongyu; Liu, Gang; Chen, Yao; Guo, Zhenzhen; Jia, Jie

    2013-11-13

    Increasing evidence shows that exposure to an enriched environment (EE) after cerebral ischemia/reperfusion injury is neuroprotective in animal models. Recent studies have demonstrated that animals housed in an enriched environment condition after an experimental stroke obtained a better functional outcome than those housed in a standard condition. However, little is known about the underlying mechanisms of neuroprotective effects of enriched environment exposure prior to injury. The current study examined the neuroprotective effects of prior enriched environment exposure after transient middle cerebral artery occlusion (MCAO) in rats. Male Sprague Dawley (SD) rats, weighing 55-65g at the beginning of the experiment, were randomly assigned to a pre-ischemic enriched environment (PIEE) or pre-ischemic standard condition (PISC) group for 1 month. They were weighed on days1, 7, 18, and 28, and their locomotor activity was tracked during the period between 9:00am and 3:00pm daily. After 1 month, ischemia was induced by occluding the middle cerebral artery for 90min, followed by reperfusion. After approximately 24h of the operation, functional outcomes were assessed using the beam-walking test and a neurological evaluation scale in all rats. We measured the expression of extracellular signal regulated protein kinases1/2 (ERK1/2) by western blotting and gene expression levels of neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthasen (iNOS) by Real-Time PCR in the cortical area affected by ischemia. Finally, we measured the level of malondialdehyde (MDA) content, which is a biomarker of oxidative stress. The results showed that rats in the PIEE group had lighter weight than those in the PISC group. The functional outcomes of rats in the PIEE group were better than those in the PISC group, and substances associated with inflammation, such as MDA, nNOS, iNOS, and phospho-ERK1/2, were lower in the PIEE group compared with the PISC group. These results

  3. 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.

  4. Penetration of tungsten-alloy rods into composite ceramic targets: Experiments and 2-D simulations

    NASA Astrophysics Data System (ADS)

    Rosenberg, Z.; Dekel, E.; Hohler, V.; Stilp, A. J.; Weber, K.

    1998-07-01

    A series of terminal ballistics experiments, with scaled tungsten-alloy penetrators, was performed on composite targets consisting of ceramic tiles glued to thick steel backing plates. Tiles of silicon-carbide, aluminum nitride, titanium-dibroide and boron-carbide were 20-80 mm thick, and impact velocity was 1.7 km/s. 2-D numerical simulations, using the PISCES code, were performed in order to simulate these shots. It is shown that a simplified version of the Johnson-Holmquist failure model can account for the penetration depths of the rods but is not enough to capture the effect of lateral release waves on these penetrations.

  5. 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.

  6. Larval Fish of Selected Aquatic Habitats on the Lower Mississippi River.

    DTIC Science & Technology

    1983-02-01

    high stages, with an 18.7-m difference in vater level. The aver- age water velocity within the main channel is from 0.9 to 1.9 a/sec with a maximum...flowmeter readings . In the case of the habitat comparisons, stations representing the locations (e.g., main channel or Carolina Revetment) were pooled...34Larval Suckers (Pisces- Catostomidae ) from the Lower Mississippi River," Association of Southeastern Biologists Bulletin, Vol 25, No. 2, p 56. ! ! 1979a

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

    SciTech Connect

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

    2007-10-15

    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.

  8. Liquid Lithium Limiter Effects on Tokamak Plasmas and Plasma-Liquid Surface Interactions

    SciTech Connect

    R. Kaita; R. Majeski; R. Doerner; G. Antar; M. Baldwin; R. Conn; P. Efthimion; M. Finkenthal; D. Hoffman; B. Jones; S. Krashenninikov; H. Kugel; S. Luckhardt; R. Maingi; J. Menard; T. Munsat; D. Stutman; G. Taylor; J. Timberlake; V. Soukhanovskii; D. Whyte; R. Woolley; L. Zakharov

    2002-10-15

    We present results from the first experiments with a large area liquid lithium limiter in a magnetic fusion device, and its effect on improving plasma performance by reducing particle recycling. Using large area liquid metal surfaces in any major fusion device is unlikely before a test on a smaller scale. This has motivated its demonstration in the CDX-U spherical torus with a unique, fully toroidal lithium limiter. The highest current discharges were obtained with a liquid lithium limiter. There was a reduction in recycling, as indicated by a significant decrease in the deuterium-alpha emission and oxygen radiation. How these results might extrapolate to reactors is suggested in recycling/retention experiments with liquid lithium surfaces under high-flux deuterium and helium plasma bombardment in PISCES-B. Data on deuterium atoms retained in liquid lithium indicate retention of all incident ions until full volumetric conversion to lithium deuteride. The PISCES-B results also show a material loss mechanism that lowers the maximum operating temperature compared to that for the liquid surface equilibrium vapor pressure. This may restrict the lithium temperature in reactors.

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

    DOE PAGES

    Doerner, R. P.; Rudakov, D. L.; Chrobak, C. P.; ...

    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

  10. The Origin of the Common Yearly Counting in the Julian and Gregorian Calendar with Special Attention to the Ancient Astronomy and World View

    NASA Astrophysics Data System (ADS)

    Rothwangl, Sepp

    Because of a new consideration and recently revealed new facts and documents it is maintained that Dionysius Exiguus fixed the common Christian yearly count with the aim to mark the begin and end of the age of Pisces. By incorporating of three factors, he precalculated the conjunction of all naked eye planets including Sun and Moon of May 2000. He figured it out with the help of so called eternal planet boards and a ``plotting year calculation'' (Zieljahrberechnung). Then he determined the year 1 A. D. exactly 1999 years before it, due the medieval assumed constant of precession, (66 2/3 years each degree), that was base of calculation of later Arabian and Persian astronomers. Thus he linked the ``Platonic Year'' with the ``Greatest Year''. He did this in order to fulfil the Christian belief of the return of the Lord during a planetary position which is equivalent to the Greek Symposium or the start of the Kali Yuga, calculated by the Indian astronomer Aryabhata. For both calculations actually the alignment of all planets of year 531 CE was the base. In his late antique religious and astronomical world view Dionysius determined the yearly counting such a way, that the year 2000 (2nd millennium) of his count should mark the end of the age of Pisces (ICHTHYS) and the religiously prophesied Christian end time.

  11. 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.

  12. 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.

  13. 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.

  14. 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}⊙ .

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

    SciTech Connect

    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.

    2016-01-22

    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 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.

  16. Fuzzy tungsten in a magnetron sputtering device

    NASA Astrophysics Data System (ADS)

    Petty, T. J.; Khan, A.; Heil, T.; Bradley, J. W.

    2016-11-01

    Helium ion induced tungsten nanostructure (tungsten fuzz) has been studied in a magnetron sputtering device. Three parameters were varied, the fluence from 3.4 × 1023-3.0 × 1024 m-2, the He ion energy from 25 to 70 eV, and the surface temperature from 900 to 1200 K. For each sample, SEM images were captured, and measurements of the fuzz layer thickness, surface roughness, reflectivity, and average structure widths are provided. A cross-over point from pre-fuzz to fully formed fuzz is found at 2.4 ± 0.4 × 1024 m-2, and a temperature of 1080 ± 60 K. No significant change was observed in the energy sweep. The fuzz is compared to low fluence fuzz created in the PISCES-A linear plasma device. Magnetron fuzz is less uniform than fuzz created by PISCES-A and with generally larger structure widths. The thicknesses of the magnetron samples follow the original Φ1/2 relation as opposed to the incubation fluence fit.

  17. A High-Fidelity Solar System Model and High-Contrast Integral Field Spectrograph Prototype for Exoplanet Observations

    NASA Astrophysics Data System (ADS)

    Wilkins, A. N.; McElwain, M. W.; Roberge, A.; Nesvold, E.; Stark, C. C.; Kuchner, M. J.; Robinson, T.; Meadows, V. S.; Straughn, A. N.; Turnbull, M. C.; Gong, Q.; Woodgate, B.; Brandt, T.; Staplefelt, K.; Heap, S.; Hilton, G.

    2014-03-01

    and spectral capabilities. To that end, we have begun fabrication of the Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES), a lenslet-based integral field spectrograph (IFS) that will have a resolution of R~70, a wavelength span of 0.65 µm to 0.9 µm, and used as a prototype IFS for mission concepts such as the AFTA-Coronagraph, the Probe Science and Technology (STDT) teams, and ATLAST. Upon completion in 2015, PISCES will be integrated into the High-Contrast Imaging Testbed (HCIT) at NASA JPL, where it will undergo simulations with the Haystacks models and also be available to the community for testing. We present the design of PISCES, its current status, and preliminary simulations specific to the PISCES parameters of how exoplanetary systems formulated with Haystacks would look to PISCES and what those results mean for detectability of exoEarths and potential biomarkers.

  18. 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

  19. 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

  20. 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

  1. Batrachochytrium dendrobatidis in Confiscated Telmatobius in Lima, Peru.

    PubMed

    Zevallos, Samanta; Elías, Roberto K; Berenguel, Raúl A; Weaver, Thomas J; Reading, Richard P

    2016-10-01

    The Peruvian Andes are the home of 27 species of frogs of the genus Telmatobius, many of which are critically endangered. Illegal trade of adult frogs for purported medical properties likely represents the major threat facing these species. This activity, besides reducing their populations, may contribute to the dissemination of the fungus Batrachochytrium dendrobatidis (Bd), which causes chytridiomycosis, a disease posing a threat to many populations of amphibians. We screened frogs confiscated by the Administration of Forestry and Wildlife in Lima, Peru, for Bd. We used real-time PCR to diagnose Bd at the Laboratory of Wildlife, Faculty of Veterinary Medicine and Zootecnics, Universidad Peruana Cayetano Heredia, in Lima and Pisces Molecular Laboratory in Boulder, Colorado, US. Of 62 samples collected during this study, 60% (37) were PCR positive for Bd, confirming that illegal trade of amphibians can pose a risk for disseminating Bd.

  2. How the first stars shaped the faintest gas-dominated dwarf galaxies

    NASA Astrophysics Data System (ADS)

    Verbeke, Robbert; Vandenbroucke, Bert; de Rijcke, Sven

    2016-08-01

    Cosmological simulations predict that dark matter halos with circular velocities lower than 30 km/s should have lost most of their neutral gas by heating of the ultra-violet background. This is in stark contrast with gas-rich galaxies such as e.g. Leo T, Leo P and Pisces A, which all have circular velocities of ~15 km/s (Ryan-Weber et al. 2008, Bernstein-Cooper et al. 2014, Tollerud et al. 2015). We show that when we include feedback from the first stars into our models, simulated dwarfs have very different properties at redshift 0 than when this form of feedback is not included. Including this Population-III feedback leads to galaxies that lie on the baryonic Tully-Fisher relation over the entire mass range of star forming dwarf galaxies, as well as reproducing a broad range of other observational properties.

  3. Morphological and molecular identification of the fish-borne metacercaria of Ascocotyle (Phagicola) longa Ransom, 1920 in Mugil liza from Argentina.

    PubMed

    Martorelli, S R; Lino, A; Marcotegui, P; Montes, M M; Alda, P; Panei, C J

    2012-12-21

    This is the first report of Ascocotyle (Phagicola) longa Ransom, 1920 (Digenea: Heterophyidae) in Argentina confirmed by morphological and molecular studies. The metacercaria was found encysted in myotomal musculature, heart and mesentery of the mullet Mugil liza (Pisces: Mugilidae) from Samborombon bay. We provide a morphological description of the metacercaria which we identified using species-specific primers for A. (Phagicola) longa and nucleotid sequence. This worldwide parasite has been reported as one of the causative agents of heterophyiosis, an emerging fish-borne disease of humans, contracted by the consumption of raw mullet. The discovery of A. (Phagicola) longa in Argentina represents a warning of the potentially great impact of this parasite on public health.

  4. Phylogenetic analysis of Mediterranean Mugilids by allozymes and 16S mt-rRNA genes investigation: are the Mediterranean species of Liza monophyletic?

    PubMed

    Rossi, Anna Rita; Ungaro, Andrea; De Innocentiis, Sabina; Crosetti, Donatella; Sola, Luciana

    2004-10-01

    The family Mugilidae (Pisces, Mugiliformes) includes species which are present in all tropical and temperate regions. Six species, Chelon labrosus, Mugil cephalus, Liza aurata, L. ramada, L. saliens, Oedalechilus labeo, are commonly found in the Mediterranean. These species have been widely studied through morphological, biochemical, and molecular markers. However, their phylogenetic relationships, and therefore the assumed monophyly of Liza species, still remain unclear: To further investigate this topic, gene-enzyme systems and sequences of the partial 16S rRNA mitochondrial gene were analyzed in Italian samples of all six Mediterranean species. The phylogenetic reconstructions indicated M. cephalus as being the most divergent species and the existence of a main cluster including all the Mediterranean species of Liza and C. labrosus. The parametric bootstrap approach adopted to test alternative phylogenetic hypotheses indicated that the Mediterranean species of Liza do not form a monophyletic group exclusive of Chelon.

  5. 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

    2015-12-21

    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.

  6. Erosion of beryllium under high-flux plasma impact

    NASA Astrophysics Data System (ADS)

    Doerner, R. P.; Björkas, C.; Nishijima, D.; Schwarz-Selinger, T.

    2013-07-01

    Be sputtering yields, measured by weight loss, in PISCES-B are a factor of 5-10 less than that predicted by binary collision approximations. Measurements show the BeO surface is removed early in the plasma bombardment. Modeling of molecular ions (D2+ and D3+) species and redeposition cannot explain the difference. Surface morphology that evolves during the exposure reduces the sputtering yield by a factor of 2-3. Plasma fuel atoms retained in the surface decrease the sputtering yield compared to calculations of a pure Be surface. These effects may explain the measured erosion rates in the absence of Be impurities within the plasma. By introducing Be impurity ions into the plasma, it is possible to simulate a controllable amount of redeposition. The weight loss from eroding Be targets, with Be seeding, is unchanged until the concentration of Be ions in the plasma greatly exceeds the sputtering yield in the non-beryllium seeded exposure.

  7. 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.

  8. 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.

  9. Word Frequency Analysis MOS: 41C Skill Levels 1 & 2.

    DTIC Science & Technology

    1981-05-01

    PLU"$ IPL ;APOINT I PIIETER 1 POOP PVSITIJ, PUSITIONEO I POST . I POTENTIOMETER 4,~, PISC1SIUN Pi pR?10 11 PRISM I PI’(;JE( T*,f PPllPFR iPIJPLICA...CHIAPTER - -.- - --.--- A ACH. 11 ELRr’, 11 GUNFNROS It ITE it PRISM IL SUPP.1PT It THAT it THfItI 10 ACCESS 1) OUT Inl CIACLC .- if) FOLLCMING to- 10...IITRUPTER I INT’l ; LlAll I LEVEL ING 2 LIFT 2 L IGHT% Z LlfJ 5 % 7 1’AJJR 2 tit - SFR IES 2 MULTIMETEP .1 -lJ ;l A11 03/A 10 4 1 - 2 M!Il .2 wiIl - 2

  10. Optimal, real-time control--colliders

    SciTech Connect

    Spencer, J.E.

    1991-05-01

    With reasonable definitions, optimal control is possible for both classical and quantal systems with new approaches called PISC(Parallel) and NISC(Neural) from analogy with RISC (Reduced Instruction Set Computing). If control equals interaction, observation and comparison to some figure of merit with interaction via external fields, then optimization comes from varying these fields to give design or operating goals. Structural stability can then give us tolerance and design constraints. But simulations use simplified models, are not in real-time and assume fixed or stationary conditions, so optimal control goes far beyond convergence rates of algorithms. It is inseparable from design and this has many implications for colliders. 12 refs., 3 figs.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Data on sediment quality and concentrations of polychlorinated biphenyls from the Lower Neponset River, Massachusetts, 2002-03

    USGS Publications Warehouse

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

    2004-01-01

    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 in the lower Neponset River, which is a tributary to Boston Harbor. Grab and core samples of sediment were tested for elements and organic compounds including polyaromatic hydrocarbons, organochlorine pesticides, and polychlorinated biphenyls. Physical properties of sediment samples, including grain size, were also measured. Selected sediment-core samples were tested for reactive sulfides and metals by means of the toxicity characteristic leaching procedure, which are sediment-disposal-related tests. Water quality, with respect to polychlorinated biphenyl contamination, was determined by testing samples collected by PISCES passive-water-column samplers for polychlorinated biphenyl congeners. Total concentrations of polychlorinated biphenyls were calculated by congener and by Aroclor.

  16. Exposures of tungsten nanostructures to divertor plasmas in DIII-D

    SciTech Connect

    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.; Hollmann, E. M.; McLean, A. G.; Fenstermacher, M. E.; Lasnier, C. J.; Leonard, A. W.; Moyer, R. A.; Pace, D. C.; Thomas, D. M.; Watkins, J. G.

    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 little 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.

  17. Host–parasite coevolution beyond the nestling stage? Mimicry of host fledglings by the specialist screaming cowbird

    PubMed Central

    De Mársico, María C.; Gantchoff, Mariela G.; Reboreda, Juan C.

    2012-01-01

    Egg mimicry by obligate avian brood parasites and host rejection of non-mimetic eggs are well-known textbook examples of host–parasite coevolution. By contrast, reciprocal adaptations and counteradaptations beyond the egg stage in brood parasites and their hosts have received less attention. The screaming cowbird (Molothrus rufoaxillaris) is a specialist obligate brood parasite whose fledglings look identical to those of its primary host, the baywing (Agelaioides badius). Such a resemblance has been proposed as an adaptation in response to host discrimination against odd-looking young, but evidence supporting this idea is scarce. Here, we examined this hypothesis by comparing the survival rates of young screaming cowbirds and non-mimetic shiny cowbirds (Molothrus bonariensis) cross-fostered to baywing nests and quantifying the similarity in plumage colour and begging calls between host and cowbird fledglings. Shiny cowbirds suffered higher post-fledging mortality rates (83%) than screaming cowbirds (0%) owing to host rejection. Visual modelling revealed that screaming cowbirds, but not shiny cowbirds, were indistinguishable from host young in plumage colour. Similarly, screaming cowbirds matched baywings' begging calls more closely than shiny cowbirds. Our results strongly support the occurrence of host fledgling mimicry in screaming cowbirds and suggest a role of visual and vocal cues in fledgling discrimination by baywings. PMID:22648157

  18. Do shiny cowbird females adjust egg pecking behavior according to the level of competition their chicks face in host nests?

    PubMed

    Tuero, Diego T; Fiorini, Vanina D; Reboreda, Juan C

    2012-02-01

    Interspecific brood parasites, like the shiny cowbird (Molothrus bonariensis), lay eggs in nests of other species. Shiny cowbird females peck and puncture eggs when they parasitize host nests. This behavior increases the survival of cowbird chicks when they have to compete for food with larger nestmates. However, cowbird chicks may benefit from smaller nestmates as they increase food provisioning by parents and the cowbird chicks secure most extra provisioning. We investigated whether egg-pecking behavior by female shiny cowbirds might be adjusted to the competition that their chicks face in host nests. We found that more host eggs are destroyed per cowbird egg laid in a larger-bodied host (chalk-browed mockingbird, Mimus saturninus, 70-75 g) than a smaller-bodied host (house wrens, Troglodytes aedon, 12-13 g). We also tested egg-pecking preferences in choice experiments with female cowbirds in captivity and found cowbirds presented with eggs in artificial nests pecked first and more frequently, and punctured more frequently the larger egg when this was a host egg, but not when this was a cowbird egg. Our results are partially consistent with the hypothesis that shiny cowbird females adaptively adjust their egg pecking behavior according to the competition that their chicks face in host nests.

  19. 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.

  20. Frugivory and seed dispersal of Solanum granuloso-leprosum Dunal (Solanaceae) by birds in deciduous seasonal forest.

    PubMed

    Jacomassa, F A F

    2016-01-01

    The goal of this study was to identify which bird species consume Solanum granuloso-leprosum fruits and disperse its seeds. 60 hours of focal observations were carried out between April and May 2006 on the edge of a deciduous forest fragment in the Uruguay River region, Rio Grande do Sul state, Brazil. Ten species were observed in total removing 443 fruits. Saltator similis removed 61.8% of the fruits, followed by Tangara sayaca (17.1%), Pipraeidea bonariensis (11.7%), and T. preciosa (6.8%), while the remaining six species accounted for only 2.5% of the fruits removed. Most fruit removal occurred early in the day or mid-afternoon. The most common feeding behaviors were picking (60.7%), followed by stalling (23%) and hovering (16%). Birds flew more than 10 m from the fruit plant in 62% of the removal events. All bird species observed here may be considered potential dispersers of S. granuloso-leprosum, as they moved the seeds away from the mother plant where strong competition and predation are likely to occur. Results also suggest that S. granuloso-leprosum may be useful in ecological restoration programs.

  1. Crossover of the Hypothalamic Pituitary–Adrenal/Interrenal, –Thyroid, and –Gonadal Axes in Testicular Development

    PubMed Central

    Castañeda Cortés, Diana C.; Langlois, Valerie S.; Fernandino, Juan I.

    2014-01-01

    Besides the well-known function of thyroid hormones (THs) for regulating metabolism, it has recently been discovered that THs are also involved in testicular development in mammalian and non-mammalian species. THs, in combination with follicle stimulating hormone, lead to androgen synthesis in Danio rerio, which results in the onset of spermatogenesis in the testis, potentially relating the hypothalamic–pituitary–thyroid (HPT) gland to the hypothalamic–pituitary–gonadal (HPG) axes. Furthermore, studies in non-mammalian species have suggested that by stimulating the thyroid-stimulating hormone (TSH), THs can be induced by corticotropin-releasing hormone. This suggests that the hypothalamic–pituitary–adrenal/interrenal gland (HPA) axis might influence the HPT axis. Additionally, it was shown that hormones pertaining to both HPT and HPA could also influence the HPG endocrine axis. For example, high levels of androgens were observed in the testis in Odonthestes bonariensis during a period of stress-induced sex-determination, which suggests that stress hormones influence the gonadal fate toward masculinization. Thus, this review highlights the hormonal interactions observed between the HPT, HPA, and HPG axes using a comparative approach in order to better understand how these endocrine systems could interact with each other to influence the development of testes. PMID:25221542

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Egg puncture allows shiny cowbirds to assess host egg development and suitability for parasitism

    PubMed Central

    Massoni, V.; Reboreda, J. C.

    1999-01-01

    Parasitic cowbirds and cuckoos generally reduce the clutch size of the hosts they parasitize by removing or destroying some of their eggs. Shiny cowbirds (Molothrus bonariensis) puncture their hosts' eggs both when parasitizing the nests and also when they do not parasitize them. We propose that, by puncturing the host's eggs, shiny cowbirds gain an informational benefit. They assess the degree of development of the host's embryos and so avoid laying in nests that would not provide enough incubation time for the parasitic eggs to hatch. Two predictions follow: (i) punctures should occur in advance or immediately before parasitic events, and (ii) the occurrence of parasitism should depend on the degree of development of the host's embryos when punctures occurred, i.e. on the stage of incubation. Both predictions are supported by our data of shiny cowbirds parasitizing yellow-winged blackbirds (Agelaius thilius). Egg punctures are not used to reset the host's nesting attempt when shiny cowbirds do not parasitize the nests. We discuss the potential mechanisms implicated in egg development assessment and propose a critical experiment to test this hypothesis.

  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.

  9. 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).

  10. A novel method of rejection of brood parasitic eggs reduces parasitism intensity in a cowbird host

    PubMed Central

    De Mársico, María C.; Gloag, Ros; Ursino, Cynthia A.; Reboreda, Juan C.

    2013-01-01

    The hosts of brood parasitic birds are under strong selection pressure to recognize and remove foreign eggs from their nests, but parasite eggs may be too large to be grasped whole and too strong to be readily pierced by the host's bill. Such operating constraints on egg removal are proposed to force some hosts to accept parasite eggs, as the costs of deserting parasitized clutches can outweigh the cost of rearing parasites. By fitting microcameras inside nests, we reveal that the Neotropical baywing (Agelaioides badius), a host of the screaming cowbird (Molothrus rufoaxillaris) and shiny cowbird (Molothrus bonariensis), instead circumvents such constraints by kicking parasite eggs out of the nest. To our knowledge, this is the first report of a passerine bird using its feet to remove objects from the nest. Kick-ejection was an all-or-nothing response. Baywings kick-ejected parasite eggs laid before their own first egg and, if heavily parasitized, they ejected entire clutches and began again in the same nest. Few baywings were able to rid their nests of every parasite egg, but their novel ejection method allowed them to reduce the median parasitism intensity by 75 per cent (from four to one cowbird eggs per nest), providing an effective anti-parasite defence. PMID:23485877

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. The seasonal cycle as a mode to diagnose biases in modelled CO2 fluxes in the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Mongwe, N. Precious; Chang, Nicolette; Monteiro, Pedro M. S.

    2016-10-01

    The Southern Ocean forms a key component of the global carbon budget, taking up about 1.0 Pg C yr-1 of anthropogenic CO2 emitted annually (∼10.7 ± 0.5 Pg C yr-1 for 2012). However, despite its importance, it still remains undersampled with respect to surface ocean carbon flux variability, resulting in weak constraints for ocean carbon and carbon - climate models. As a result, atmospheric inversion and coupled physics-biogeochemical ocean models still play a central role in constraining the air-sea CO2 fluxes in the Southern Ocean. A recent synthesis study (Lenton et al., 2013a), however, showed that although ocean biogeochemical models (OBGMs) agree on the mean annual flux of CO2 in the Southern Ocean, they disagree on both amplitude and phasing of the seasonal cycle and compare poorly to observations. In this study, we develop and present a methodological framework to diagnose the controls on the seasonal variability of sea-air CO2 fluxes in model outputs relative to observations. We test this framework by comparing the NEMO-PISCES ocean model ORCA2-LIM2-PISCES to the Takahashi 2009 (T09) CO2 dataset. Here we demonstrate that the seasonal cycle anomaly for CO2 fluxes in ORCA2LP is linked to an underestimation of winter convective CO2 entrainment as well as the impact of biological CO2 uptake during the spring-summer season, relative to T09 observations. This resulted in sea surface temperature (SST) becoming the dominant driver of seasonal scale of the partial pressure of CO2 (pCO2) variability and hence of the differences in the seasonality of CO2 sea-air flux between the model and observations.

  16. 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.

  17. Simulation to Seismic Fluid Substitution Modeling at the Illinois Basin - Decatur Project

    NASA Astrophysics Data System (ADS)

    Will, R. A.

    2015-12-01

    The Illinois Basin - Decatur Project (IBDP) is one of the most advanced US Department of Energy-funded carbon dioxide (CO2) sequestration projects. The goal of injecting 1 million tonnes of CO2 over a three year period was reached in November 2014 and the project is now in the post injection site closure (PISC) phase. A number of seismic methods are being utilized in the IBDP PISC plume monitoring program. These include time lapse three-dimensional (3D) vertical seismic profile (VSP) surveys, time-lapse surface seismic surveys, and passive seismic monitoring. While each seismic monitoring method has inherent spatial resolution and imaging footprint characteristics, all fundamentally rely on variation of reservoir elastic properties in response to injection induced changes in saturation and pressure conditions. These variations in elastic properties, and the resulting time-lapse seismic response, are often subtle and non-unique with respect to saturation and pressure effects. Elastic properties of saturated porous media may be estimated using rock physics theory and fluid substitution methods; however, the complexity of typical reservoir rock and fluid systems under injection conditions, and the subtlety of the resulting changes in elastic properties, dictate the need for representative estimates of the reservoir geologic framework, reservoir rock physics, and the anticipated plume geometry. At IBDP a "simulation-to-seismic" workflow has been used to develop accurate estimates of 3D time-lapse elastic property and seismic signal responses for CO2 plumes generated using a calibrated compositional flow simulation model. The anticipated time-lapse response for the IBDP surface and VSP time-lapse surveys have been estimated using ranges of rock physics parameters derived from geophysical logs. These investigations highlight the importance of geologic controls on plume geometry in monitoring program design as well as during model-based interpretation of time

  18. VizieR Online Data Catalog: A search for ultra-compact HVC counterparts (Sand+, 2015)

    NASA Astrophysics Data System (ADS)

    Sand, D. J.; Crnojevic, D.; Bennet, P.; Willman, B.; Hargis, J.; Strader, J.; Olszewski, E.; Tollerud, E. J.; Simon, J. D.; Caldwell, N.; Guhathakurta, P.; James, B. L.; Koposov, S.; McLeod, B.; Morrell, N.; Peacock, M.; Salinas, R.; Seth, A. C.; Stark, D. P.; Toloba, E.

    2015-10-01

    We have searched all available optical and ultraviolet imaging archives for counterparts to the ultra-compact high-velocity clouds (UCHVCs; see section 2.1 and table 1). In addition to our archival search for counterparts to the UCHVCs, we have also acquired some supplementary imaging of select systems with the Magellan/Megacam in 2013 Jun 11 and 2014 Apr 26-27 and the APO/SPICAM in 2014 Nov 17 (see section 2.2). We have obtained spectroscopic observations for all six of the strong dwarf galaxy candidates identified in our search. ALFALFA-Dw1 (HVC274.68+74.70-123) was observed with the Inamori- Magellan Areal Camera and Spectrograph (IMACS) on the Magellan Baade telescope on 2014 June 17 (UT). GALFA-Dw1 (GALFA source 003.7+10.8+236), also known as Pisces A was observed on 2014 June 29 (UT) using the Goodman High-Throughput Spectrograph on the SOAR 4.1m telescope. GALFA-Dw2 (GALFA source 019.8+11.1+617), also known as Pisces B, was observed on 2014 October 21 (UT) with the Blue Channel Spectrograph on the MMT. GALFA-Dw3 (GALFA source 044.7+13.6+528) and GALFA-Dw4 (GALFA source 086.4+10.8+611) were observed with the 3.5m Astrophysical Research Consortium Telescope at APO on 2014 November 18 (UT) using the Dual Imaging Spectrograph (DIS). The faint, blue optical source coincident with GALFA 162.1+12.5+434 (see Figure 2) was observed on 2014 December 24 (UT) with the Blue Channel Spectrograph on the MMT. (2 data files).

  19. Spatial and body-size dependent response of marine pelagic communities to projected global climate change.

    PubMed

    Lefort, Stelly; Aumont, Olivier; Bopp, Laurent; Arsouze, Thomas; Gehlen, Marion; Maury, Olivier

    2015-01-01

    Temperature, oxygen, and food availability directly affect marine life. Climate models project a global warming of the ocean's surface (~+3 °C), a de-oxygenation of the ocean's interior (~-3%) and a decrease in total marine net primary production (~-8%) under the 'business as usual' climate change scenario (RCP8.5). We estimated the effects of these changes on biological communities using a coupled biogeochemical (PISCES)--ecosystems (APECOSM) model forced by the physical outputs of the last generation of the IPSL-CM Earth System Model. The APECOSM model is a size-structured bio-energetic model that simulates the 3D dynamical distributions of three interactive pelagic communities (epipelagic, mesopelagic, and migratory) under the effects of multiple environmental factors. The PISCES-APECOSM model ran from 1850 to 2100 under historical forcing followed by RCP8.5. Our RCP8.5 simulation highlights significant changes in the spatial distribution, biomass, and maximum body-size of the simulated pelagic communities. Biomass and maximum body-size increase at high latitude over the course of the century, reflecting the capacity of marine organisms to respond to new suitable environment. At low- and midlatitude, biomass and maximum body-size strongly decrease. In those regions, large organisms cannot maintain their high metabolic needs because of limited and declining food availability. This resource reduction enhances the competition and modifies the biomass distribution among and within the three communities: the proportion of small organisms increases in the three communities and the migrant community that initially comprised a higher proportion of small organisms is favored. The greater resilience of small body-size organisms resides in their capacity to fulfill their metabolic needs under reduced energy supply and is further favored by the release of predation pressure due to the decline of large organisms. These results suggest that small body-size organisms might be

  20. Controlled Expression and Functional Analysis of Iron-Sulfur Cluster Biosynthetic Components within Azotobacter vinelandii▿

    PubMed Central

    Johnson, Deborah C.; Unciuleac, Mihaela-Carmen; Dean, Dennis R.

    2006-01-01

    A system for the controlled expression of genes in Azotobacter vinelandii by using genomic fusions to the sucrose catabolic regulon was developed. This system was used for the functional analysis of the A. vinelandii isc genes, whose products are involved in the maturation of [Fe-S] proteins. For this analysis, the scrX gene, contained within the sucrose catabolic regulon, was replaced by the contiguous A. vinelandii iscS, iscU, iscA, hscB, hscA, fdx, and iscX genes, resulting in duplicate genomic copies of these genes: one whose expression is directed by the normal isc regulatory elements (Pisc) and the other whose expression is directed by the scrX promoter (PscrX). Functional analysis of [Fe-S] protein maturation components was achieved by placing a mutation within a particular Pisc-controlled gene with subsequent repression of the corresponding PscrX-controlled component by growth on glucose as the carbon source. This experimental strategy was used to show that IscS, IscU, HscBA, and Fdx are essential in A. vinelandii and that their depletion results in a deficiency in the maturation of aconitase, an enzyme that requires a [4Fe-4S] cluster for its catalytic activity. Depletion of IscA results in a null growth phenotype only when cells are cultured under conditions of elevated oxygen, marking the first null phenotype associated with the loss of a bacterial IscA-type protein. Furthermore, the null growth phenotype of cells depleted of HscBA could be partially reversed by culturing cells under conditions of low oxygen. Conserved amino acid residues within IscS, IscU, and IscA that are essential for their respective functions and/or whose replacement results in a partial or complete dominant-negative growth phenotype were also identified using this system. PMID:16936042

  1. 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.

  2. 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.

  3. 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.

  4. Mapping Milky Way Halo Structure with Blue Horizontal Branch Stars

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

    The use of blue horizontal brach (BHB) and red giant branch stars as tracers of stellar debris streams is a common practice and has been useful in the confirmation of kinematic properties of previously identified streams. This work explores less common ways of untangling the velocity signatures of streams traveling radially to our line of sight, and to peer toward the higher density region of the Galactic Center using data from the Sloan Digital Sky Survey (SDSS). Using spectra of BHB stars, we are able to kinematically distinguish moving groups in the Milky Way halo. The results of this thesis advance our knowledge of the following stellar halo substructures: the Pisces Stellar Stream, the Hercules-Aquila Cloud, the Hercules Halo Stream, and the Hermus Stream. A study of red giant stars led to the kinematic discovery of the Pisces Stellar Stream. Red giant stars were also examined to determine that the previously identified velocity signature that was suggested for the Hercules-Aquila Cloud was due to disk star contamination and errors in preliminary SDSS velocities. The Hercules Halo Stream is a previously unidentified structure that could be related to the Hercules-Aquila Cloud, and was discovered as a velocity excess of SDSS BHB stars. We identify a group of 10 stars with similar velocities that are spatially coincident with the Hermus Stream. An orbit is fit to the Hermus Stream that rules out a connection with the Phoenix Stream.This work was supported by NSF grants AST 09-37523, 14-09421, 16-15688, the NASA/NY Space Grant fellowship, and contributions made by The Marvin Clan, Babette Josephs, Manit Limlamai, and the 2015 Crowd Funding Campaign to Support Milky Way Research.

  5. Cytotoxic effects of Argentinean plant extracts on tumour and normal cell lines.

    PubMed

    Mamone, L; Di Venosa, G; Valla, J J; Rodriguez, L; Gándara, L; Batlle, A; Heinrich, M; Juarranz, A; Sanz-Rodriguez, F; Casas, A

    2011-05-30

    In the search for possible new anti-cancer agents, we investigated the effects of 75 aqueous and methanol extracts from 41 Argentinean plant species. The effect in cell growth was evaluated in the LM2 mammary adenocarcinoma cells. In a second stage, the highly active selected extracts were assayed in 3 other tumour cell lines: melanoma B16, bladder MB49 and lung A549; and 3 normal cell lines: mammary Hb4a and keratinocytes PAM212 and HaCat. Eight methanol extracts were found to be highly cytotoxic: Collaea argentina leaf, Iochroma australe leaf, Ipomoea bonariensis flower, Jacaranda mimosifolia flower, Solanum amygdalifolium flower, Solanum chacoense leaf, Solanum sisymbriifolium flower and Solanum verbascifolium flower. However, extract inhibition on cell growth was highly dependent on cell type. In general, except for the highly resistant cell lines, the inhibitory concentrations 50% were in the range of 10-150 μg/ml The eight extracts highly inhibited cell growth in a concentration-dependent manner, and in general the methanol extracts were always more active than the aqueous. Murine cells appear to be more sensitive than human cells to the cytotoxic action of the plant extracts. The human melanoma B16 line was the most resistant to four of the extracts. In terms of selectivity, S. verbascifolium was the species which showed most selectivity for tumour cells. Overall, this is one of the first studies focusing on southern South American native plants and their biological effects. Since some species of 5 genera analyzed have been reported to possess different degrees of alkaloid content, we examined microtubule structures after extract treatments. The eight extracts induced destabilization, condensation and aggregation of microtubules in LM2 cells, although no depolarization, typical of Vinca alkaloids damage was observed. In a near future, antitumour activity of purified fractions of the extracts administered at non-toxic doses will be assayed in transplantable

  6. The cortisol and androgen pathways cross talk in high temperature-induced masculinization: the 11β-hydroxysteroid dehydrogenase as a key enzyme.

    PubMed

    Fernandino, Juan Ignacio; Hattori, Ricardo Shohei; Kishii, Ai; Strüssmann, Carlos Augusto; Somoza, Gustavo Manuel

    2012-12-01

    In many ectotherm species the gonadal fate is modulated by temperature early in life [temperature-dependent sex determination (TSD)] but the transducer mechanism between temperature and gonadal differentiation is still elusive. We have recently shown that cortisol, the glucocorticoid stress-related hormone in vertebrates, is involved in the TSD process of pejerrey, Odontesthes bonariensis. Particularly, all larvae exposed to a male-producing temperature (MPT, 29 C) after hatching showed increased whole-body cortisol and 11-ketotestosterone (11-KT; the main bioactive androgen in fish) levels and developed as males. Moreover, cortisol administration at an intermediate, mixed sex-producing temperature (MixPT, 24 C) caused increases in 11-KT and in the frequency of males, suggesting a relation between this glucocorticoid and androgens during the masculinization process. In order to clarify the link between stress and masculinization, the expression of hydroxysteroid dehydrogenase (hsd)11b2, glucocorticoid receptors gr1 and gr2, and androgen receptors ar1 and ar2 was analyzed by quantitative real time PCR and in situ hybridization in larvae reared at MPT, MixPT, and female-producing temperature (FPT, 17 C) during the sex determination period. We also analyzed the effects of cortisol treatment in larvae reared at MixPT and in adult testicular explants incubated in vitro. MPT and cortisol treatment produced significant increases in hsd11b2 mRNA expression. Also, gonadal explants incubated in the presence of cortisol showed increases of 11-KT levels in the medium. Taken together these results suggest that cortisol promotes 11-KT production during high temperature-induced masculinization by modulation of hsd11b2 expression and thus drives the morphogenesis of the testes.

  7. Mercury concentrations of fish, river water, and sediment in the Río Ramis-Lake Titicaca watershed, Peru.

    PubMed

    Gammons, Christopher H; Slotton, Darell G; Gerbrandt, Butch; Weight, Willis; Young, Courtney A; McNearny, Richard L; Cámac, Eugenio; Calderón, Ruben; Tapia, Henri

    2006-09-15

    This study reports the first set of data on the concentration of mercury in muscle tissue of several varieties of fish from Lake Titicaca, including the pejerrey (Basilichthyes bonariensis), the carachi (Orestias), and 2 types of indigenous catfish (Trichomycterus). Approximately 27% of the pejerrey and 75% of the carachi exceeded the US EPA fish tissue-based water quality criterion level of 0.30 microg g(-1). Mercury levels of pejerrey increased with fish size, although this relationship was less apparent for the smaller carachi. The pejerrey and carachi are important food fish for local residents. A synoptic sampling of the Río Ramis--the largest tributary to Lake Titicaca--was conducted in an attempt to determine if mercury releases from artisanal gold mining could be an important source of Hg contamination to Lake Titicaca. Although highly elevated concentrations of Hg and other heavy metals were documented in headwater streams near the mining centers of La Rinconada and Cecilia, the quantity of Hg entering Lake Titicaca that could be attributed to mining in the Ramis watershed was below the quantifiable limit in our July 2002 study. This does not diminish the localized threat to mercury exposure for the artisanal gold miners themselves, as well as their families. Further studies of mercury dynamics in Lake Titicaca are recommended, as well as in the rivers draining into the lake. It is probable that most of the downgradient transport of Hg and other trace metals from the headwater mining centers occurs as suspended sediment during seasonal periods of high-flow.

  8. Agricultural impacts of glyphosate-resistant soybean cultivation in South America.

    PubMed

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

    2011-06-08

    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.

  9. 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.

  10. Pollination in Nicotiana alata stimulates synthesis and transfer to the stigmatic surface of NaStEP, a vacuolar Kunitz proteinase inhibitor homologue

    PubMed Central

    Busot, Grethel Yanet; McClure, Bruce; Ibarra-Sánchez, Claudia Patricia; Jiménez-Durán, Karina; Vázquez-Santana, Sonia; Cruz-García, Felipe

    2008-01-01

    After landing on a wet stigma, pollen grains hydrate and germination generally occurs. However, there is no certainty of the pollen tube growth through the style to reach the ovary. The pistil is a gatekeeper that evolved in many species to recognize and reject the self-pollen, avoiding endogamy and encouraging cross-pollination. However, recognition is a complex process, and specific factors are needed. Here the isolation and characterization of a stigma-specific protein from N. alata, NaStEP (N. alata Stigma Expressed Protein), that is homologous to Kunitz-type proteinase inhibitors, are reported. Activity gel assays showed that NaStEP is not a functional serine proteinase inhibitor. Immunohistochemical and protein blot analyses revealed that NaStEP is detectable in stigmas of self-incompatible (SI) species N. alata, N. forgetiana, and N. bonariensis, but not in self-compatible (SC) species N. tabacum, N. plumbaginifolia, N. benthamiana, N. longiflora, and N. glauca. NaStEP contains the vacuolar targeting sequence NPIVL, and immunocytochemistry experiments showed vacuolar localization in unpollinated stigmas. After self-pollination or pollination with pollen from the SC species N. tabacum or N. plumbaginifolia, NaStEP was also found in the stigmatic exudate. The synthesis and presence in the stigmatic exudate of this protein was strongly induced in N. alata following incompatible pollination with N. tabacum pollen. The transfer of NaStEP to the stigmatic exudate was accompanied by perforation of the stigmatic cell wall, which appeared to release the vacuolar contents to the apoplastic space. The increase in NaStEP synthesis after pollination and its presence in the stigmatic exudates suggest that this protein may play a role in the early pollen–stigma interactions that regulate pollen tube growth in Nicotiana. PMID:18689443

  11. Intensified agriculture favors evolved resistance to biological control.

    PubMed

    Tomasetto, Federico; Tylianakis, Jason M; Reale, Marco; Wratten, Steve; Goldson, Stephen L

    2017-03-13

    Increased regulation of chemical pesticides and rapid evolution of pesticide resistance have increased calls for sustainable pest management. Biological control offers sustainable pest suppression, partly because evolution of resistance to predators and parasitoids is prevented by several factors (e.g., spatial or temporal refuges from attacks, reciprocal evolution by control agents, and contrasting selection pressures from other enemy species). However, evolution of resistance may become more probable as agricultural intensification reduces the availability of refuges and diversity of enemy species, or if control agents have genetic barriers to evolution. Here we use 21 y of field data from 196 sites across New Zealand to show that parasitism of a key pasture pest (Listronotus bonariensis; Argentine stem weevil) by an introduced parasitoid (Microctonus hyperodae) was initially nationally successful but then declined by 44% (leading to pasture damage of c. 160 million New Zealand dollars per annum). This decline was not attributable to parasitoid numbers released, elevation, or local climatic variables at sample locations. Rather, in all locations the decline began 7 y (14 host generations) following parasitoid introduction, despite releases being staggered across locations in different years. Finally, we demonstrate experimentally that declining parasitism rates occurred in ryegrass Lolium perenne, which is grown nationwide in high-intensity was significantly less than in adjacent plots of a less-common pasture grass (Lolium multiflorum), indicating that resistance to parasitism is host plant-dependent. We conclude that low plant and enemy biodiversity in intensive large-scale agriculture may facilitate the evolution of host resistance by pests and threaten the long-term viability of biological control.

  12. 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.

  13. 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

  14. 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.

  15. An automated approach for mapping persistent ice and snow cover over high latitude regions

    USGS Publications Warehouse

    Selkowitz, David J.; Forster, Richard R.

    2016-01-01

    We developed an automated approach for mapping persistent ice and snow cover (glaciers and perennial snowfields) from Landsat TM and ETM+ data across a variety of topography, glacier types, and climatic conditions at high latitudes (above ~65°N). Our approach exploits all available Landsat scenes acquired during the late summer (1 August–15 September) over a multi-year period and employs an automated cloud masking algorithm optimized for snow and ice covered mountainous environments. Pixels from individual Landsat scenes were classified as snow/ice covered or snow/ice free based on the Normalized Difference Snow Index (NDSI), and pixels consistently identified as snow/ice covered over a five-year period were classified as persistent ice and snow cover. The same NDSI and ratio of snow/ice-covered days to total days thresholds applied consistently across eight study regions resulted in persistent ice and snow cover maps that agreed closely in most areas with glacier area mapped for the Randolph Glacier Inventory (RGI), with a mean accuracy (agreement with the RGI) of 0.96, a mean precision (user’s accuracy of the snow/ice cover class) of 0.92, a mean recall (producer’s accuracy of the snow/ice cover class) of 0.86, and a mean F-score (a measure that considers both precision and recall) of 0.88. We also compared results from our approach to glacier area mapped from high spatial resolution imagery at four study regions and found similar results. Accuracy was lowest in regions with substantial areas of debris-covered glacier ice, suggesting that manual editing would still be required in these regions to achieve reasonable results. The similarity of our results to those from the RGI as well as glacier area mapped from high spatial resolution imagery suggests it should be possible to apply this approach across large regions to produce updated 30-m resolution maps of persistent ice and snow cover. In the short term, automated PISC maps can be used to rapidly

  16. First imaging results from Apertif, a phased-array feed for WSRT

    NASA Astrophysics Data System (ADS)

    Adams, Elizabeth A.; Adebahr, Björn; de Blok, Willem J. G.; Hess, Kelley M.; Hut, Boudewijn; Lucero, Danielle M.; Maccagni, Filippo; Morganti, Raffaella; Oosterloo, Tom; Staveley-Smith, Lister; van der Hulst, Thijs; Verheijen, Marc; Verstappen, Joris

    2017-01-01

    Apertif is a phased-array feed for the Westerbork Synthesis Radio Telescope (WSRT), increasing the field of view of the telescope by a factor of twenty-five. In 2017, three legacy surveys will commence: a shallow imaging survey, a medium-deep imaging survey, and a pulsars and fast transients survey. The medium-deep imaging survey will include coverage of the northern Herschel Atlas field, the CVn region, HetDex, and the Perseus-Pisces supercluster. The shallow imaging survey increases overlap with HetDex, has expanded coverage of the Perseus-Pisces supercluster, and includes part of the Zone of Avoidance. Both imaging surveys are coordinating with MaNGA and will have WEAVE follow-up. The imaging surveys will be done in full polarization over the frequency range 1130-1430 MHz, which corresponds to redshifts of z=0-0.256 for neutral hydrogen (HI). The spectral resolution is 12.2 kHz, or an HI velocity resolution of 2.6 km/s at z=0 and 3.2 km/s at z=0.256. The full resolution images will have a beam size of 15"x15"/sin(declination), and tapered data products (i.e., 30" resolution images) will also be available. The shallow survey will cover ~3500 square degrees with a four-sigma HI imaging sensitivity of 2.5x10^20 atoms cm^-2 (20 km/s linewidth) at the highest resolution and a continuum sensitivity of 15 uJy/beam (11 uJy/beam for polarization data). The current plan calls for the medium deep survey to cover 450 square degrees and provide an HI imaging sensitivity of 1.0x10^20 atoms cm^-2 at the highest resolution and a continuum sensitivity of 6 uJy/beam, close to the confusion limit (4 uJy/beam for polarization data, not confusion limited). Up-to-date information on Apertif and the planned surveys can be found at: http://www.apertif.nl.Commissioning of the Apertif instrument is currently underway. Here we present first results from the image commissioning, including the detection of HI absorption plus continuum and HI imaging. These results highlight the data quality

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. A sequential approach to calibrate ecosystem models with multiple time series data

    NASA Astrophysics Data System (ADS)

    Oliveros-Ramos, Ricardo; Verley, Philippe; Echevin, Vincent; Shin, Yunne-Jai

    2017-02-01

    When models are aimed to support decision-making, their credibility is essential to consider. Model fitting to observed data is one major criterion to assess such credibility. However, due to the complexity of ecosystem models making their calibration more challenging, the scientific community has given more attention to the exploration of model behavior than to a rigorous comparison to observations. This work highlights some issues related to the comparison of complex ecosystem models to data and proposes a methodology for a sequential multi-phases calibration (or parameter estimation) of ecosystem models. We first propose two criteria to classify the parameters of a model: the model dependency and the time variability of the parameters. Then, these criteria and the availability of approximate initial estimates are used as decision rules to determine which parameters need to be estimated, and their precedence order in the sequential calibration process. The end-to-end (E2E) ecosystem model ROMS-PISCES-OSMOSE applied to the Northern Humboldt Current Ecosystem is used as an illustrative case study. The model is calibrated using an evolutionary algorithm and a likelihood approach to fit time series data of landings, abundance indices and catch at length distributions from 1992 to 2008. Testing different calibration schemes regarding the number of phases, the precedence of the parameters' estimation, and the consideration of time varying parameters, the results show that the multiple-phase calibration conducted under our criteria allowed to improve the model fit.

  6. Global update: UK.

    PubMed

    Culme-Seymour, Emily J

    2012-11-01

    2012 has been an exciting year in the UK with substantial development on every front - research, clinical, industry and government. In particular, the focus has now moved to encompass far more post-research activities, with the continued enrolment of patients onto two pioneering Phase I clinical trials: ReNeuron's ReN001 stem cell therapy for stroke (PISCES) in Southern General Hospital, Greater Glasgow and Advanced Cell Technology's retinal pigment epithelial cells derived from human embryonic stem cells for Stargardts macular dystrophy and dry age-related macular degeneration at Moorfields Eye Hospital, London. The funding landscape for the sector has evolved from previous years to more fully embrace development and translation, including the provision of £180 million available for biomedical research via the Biomedical Catalyst Fund (joint Technology Strategy Board and Medical Research Council [MRC] funding) and a further £25 million through the UK Research Council's UK Regenerative Medicine Platform initiative, as well as ongoing developments with the Cell Therapy Catapult, which all act to further encourage a pan-UK collaborative environment. Overall, the UK cell therapy community continues to thrive and impact heavily upon the worldwide sector, with an established research base, a solid approach to translation and a small but growing commercial sector that is going from strength to strength.

  7. Penetrating the "zone of avoidance:. IV. an optical survey for hidden galaxies in the region 130d <= L <= 180d, -5d <= B <= +5d.

    NASA Astrophysics Data System (ADS)

    Saurer, W.; Seeberger, R.; Weinberger, R.

    1997-12-01

    As the fourth part in a series of papers on galaxies in the "zone of avoidance" (ZOA) of the Milky Way we present a compilation of 1067 galaxies discovered during a systematic search on Palomar Observatory Sky Survey I (POSS I) red-sensitive prints. The region searched comprises 500 square degrees, at 130d <= l <= 180d, -5d <= b <= +5d. In addition to galactic and equatorial coordinates, we list maximum and minimum optical diameters derived from both the red- and blue-sensitive prints and made cross checks with the IRAS PSC catalogue. An asymmetric distribution of the galaxies with respect to the galactic equator is found and is compared to the locations of optically visible dust clouds and/or the distribution of IR-emitting dust material. There is a pronounced bridge of galaxies across the galactic plane at l ~160d which will be discussed according to recent results on the extension of the Pisces-Perseus supercluster. Table 1 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

  8. VizieR Online Data Catalog: Galaxies in the "zone of avoidance". IV. (Saurer+, 1997)

    NASA Astrophysics Data System (ADS)

    Saurer, W.; Seeberger, R.; Weinberger, R.

    1997-04-01

    As the fourth part in a series of papers on galaxies in the "zone of avoidance" (ZOA) of the Milky Way we present a compilation of 1067 galaxies discovered during a systematic search on Palomar Observatory Sky Survey I (POSSI) red-sensitive prints. The region searched comprises 500 square degrees, at 130°<=l<=180°, -5°<=b<=+5°. In addition to galactic and equatorial coordinates, we list maximum and minimum optical diameters derived from both the red- and blue-sensitive prints and made cross checks with the IRAS PSC catalogue. An asymmetric distribution of the galaxies with respect to the galactic equator is found and is compared to the locations of optically visible dust clouds and/or the distribution of IR-emitting dust material. There is a pronounced bridge of galaxies across the galactic plane at l=~160° which will be discussed according to recent results on the extension of the Pisces-Perseus supercluster. (1 data file).

  9. 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.

  10. 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.

  11. Universality of intermittent convective transport in the scrape-off layer of magnetically confined devices

    NASA Astrophysics Data System (ADS)

    Antar, Ghassan Y.; Counsell, Glenn; Yu, Yang; Labombard, Brian; Devynck, Pascal

    2003-02-01

    The nature of intermittency, long observed in magnetic fusion devices, was revisited lately [G. Antar et al., Phys. Rev. Lett. 87, 065001 (2001)]. It was shown that intermittency is caused by large-scale events with high radial velocity reaching about 1/10th of the sound speed. These type of structures were named "avaloids." In the present article, the universality of convective turbulence in magnetically confined plasmas is investigated. Turbulence properties in the scrape-off layer of four different magnetic fusion devices are compared. Namely, the Tore Supra tokamak [Tore Supra Team, Nuclear Fusion, 40, 1047 (2000)] with circular cross-section limiter-bounded plasma, the Alcator C-Mod tokamak [B. LaBombard et al., Phys. Plasmas 8, 2107 (2001)] which is a divertor device, the Mega-Ampere Spherical Tokamak (MAST) [A. Sykes et al., Phys. Plasmas 8, 2101 (2001)] with vacuum chamber walls far from the plasma last closed flux surface and the PISCES linear plasma device [D. Geobel et al., Rev. Sci. Istrum. 56, 1717 (1985)]. The statistical properties of the turbulent signals in the four devices are found to be identical allowing us to conclude that intermittent convective transport by avaloids is universal in the sense that it occurs and has the same properties in many confinement devices with different configurations.

  12. 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?

  13. 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.

  14. Interdigitated back contact silicon solar cell analysis and design recommendations for space use

    NASA Astrophysics Data System (ADS)

    Marvin, Dean C.; Froedge, Sharon L.

    1989-09-01

    The Interdigitated Back Contact (IBC) solar cell is a relatively new design which has shown unprecedentedly high efficiencies. Silicon Interdigitated Back Contact cells have been fabricated that show greater than 25 percent efficiency at 100 suns Air Mass 1.5. This is far superior to conventional silicon concentrator cells which are approximately 18 percent efficient. The purpose of this report is to describe briefly the differences between this technology and conventional cells, demonstrate a near optimum design achieved by two-dimensional numerical simulation, and assess the utility of these cells for space application. The end of life (EOL) performance of this cell design in the radiation environment of space is a critical issue since the high efficiency of the design is predicated on the use of very high quality, long-diffusion length silicon. The radiation-induced degradation of this material is expected to lead to severe efficiency losses. The optimization of cell design to minimize these losses was carried out using a modified version of the two-dimensional PISCES semiconductor simulator. The final designs presented here show that the performance of IBC cells in space can significantly exceed that of conventional cells.

  15. 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.

  16. 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.

  17. Assessing the sensitivity of modeled air-sea CO2 exchange to the remineralization depth of particulate organic and inorganic carbon

    NASA Astrophysics Data System (ADS)

    Schneider, Birgit; Bopp, Laurent; Gehlen, Marion

    2008-09-01

    To assess the sensitivity of surface ocean pCO2 and air-sea CO2 fluxes to changes in the remineralization depth of particulate organic and inorganic carbon (POC, PIC), a biogeochemical ocean circulation model (PISCES) was run with different parameterizations for vertical particle fluxes. On the basis of fluxes of POC and PIC, productivity, export, and the distributions of nitrogen (NO3), dissolved inorganic carbon (DIC), and alkalinity, a number of indices defined to estimate the efficiency of carbon transport away from the atmosphere are applied. With differing success for the respective indices the results show that the more efficient the vertical transport of organic carbon toward depth, the lower the surface ocean pCO2, the higher the air-sea CO2 flux, and the stronger the increase in the oceanic inventory of DIC. Along with POC flux it is important to consider variations in PIC flux, as the net effect of particle flux reorganizations on surface ocean pCO2 is a combination of changes in DIC and alkalinity. The results demonstrate that changes in the mechanistic formulation of vertical particle fluxes have direct and indirect effects on surface ocean pCO2 and may thus interact with the atmospheric CO2 reservoir.

  18. 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

  19. 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.

  20. Exposures of tungsten nanostructures to divertor plasmas in DIII-D

    DOE PAGES

    Rudakov, D. L.; Wong, C. P. C.; Doerner, R. P.; ...

    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. Induction of micronuclei and nuclear lesions in Channa punctatus following exposure to carbosulfan, glyphosate and atrazine.

    PubMed

    Nwani, Christopher Didigwu; Nagpure, Naresh Sahebrao; Kumar, Ravindra; Kushwaha, Basdeo; Kumar, Pavan; Lakra, Wazir Singh

    2014-10-01

    The genotoxic effects of commonly used agricultural pesticides viz., carbosulfan, glyphosate, and atrazine, were evaluated in Channa punctatus (Pisces, Perciformes) using micronucleus (MN) test and induction of nuclear lesions (NL). The 96 h LC50 value were estimated by probit analysis as 0.27, 32.0 and 42.0 mg L(-1), respectively, for carbosulfan, glyphosate, and atrazine using semi-static bioassays. Based on these values, three sublethal test concentrations of carbosulfan (0.07, 0.13, 0.20 mg L(-1)), glyphosate (8.1, 16.3, 24.4 mg L(-1)) and atrazine (10.6, 21.2, 31.8 mg L(-1)) corresponding to ¼, ½ and ¾ of the LC50 of the pesticides respectively, were selected for exposure for 96 h. Peripheral blood samplings were taken at intervals of 24 h for assessment of MN and NL frequencies. Considerably higher genotoxic damage was induced by carbosulfan as compared to glyphosate and atrazine. There were significant effects (p < 0.01) of concentrations in all the treated groups. The induction of MN and NL was highest at 96 h pesticide exposure at all test concentrations. The nuclear abnormalities recorded in this study, such as blebbed-, lobed-, notched- and bi-nuclei, other than micronuclei, are indicators of genotoxic damage.

  2. [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.

  3. Performance of boron/carbon first wall materials under fusion relevant conditions

    NASA Astrophysics Data System (ADS)

    Linke, J.; Bolt, H.; Doerner, R.; Grübmeier, H.; Hirooka, Y.; Hoven, H.; Mingam, C.; Schulze, H.; Seki, M.; Wallura, E.; Weber, T.; Winter, J.

    1990-12-01

    The conditioning of the plasma facing wall in thermonuclear confinement experiments has been performed very successfully by the application of amorphous boron containing hydrogenated carbon films. Boronization leads to tokamak discharges with significantly reduced oxygen and carbon contaminations. For high heat flux components (especially in future quasi-stationary confinement experiments) new boron/carbon materials have to be developed: monolithic tiles of boronated graphites which can be brazed to watercooled substrates or thick B 4C-coatings on graphite or high-Z coolant tubes. A variety of bulk materials (boronated graphites with boron contents in the range from 3 to 30%, so-called coat mix material on the basis of B 4C) and coatings (amorphous B/C films, thick B 4C layers applied by LPPS or CVD methods) were characterized systematically. In addition the behaviour of these materials was investigated under thermal loads; erosion and disruption simulation experiments were performed in electron and ion beam high heat flux test facilities. Physical and chemical sputtering of the coat-mix-material was studied in the PISCES-B facility in dependence on the hydrogen ions fluence.

  4. Ionizing radiation effects on silicon test structures

    SciTech Connect

    Kraner, H.W.; Beuttenmuller, R.; Chen, W.; Kierstead, J.A.; Li, Z.; Zhang, Y.; Dou, L.; Fretwurst, E.; Lindstroem, G.

    1993-12-01

    The effects of {sup 60}Co gamma irradiation on MOSCAPS and special junction diode detectors have been studied. The capacitors were used to ellicit the charge accumulation and anneal in two types of thermally grown oxides representative of those used in routine detector processing. Ion implanted, oxide passivated junction detectors having 0.25 and 1 cm{sup 2} areas and perimeter to area ratios of 1 (a square), 2 and 5 were designed and constructed to amplify the ionizing effects expected to largely affect junction edges through changes in fixed oxide charges. Detectors were exposed to over 4 Mrad and showed clear increases in leakage current in proportion to the junction edge length. Annealing schedules were determined to provide a continuous response to incremental irradiations and subsequent room temperature anneals of leakage current. Besides an increase in gate threshold, little effect on the C(V) response was found. PISCES simulation of the edge fields using different fixed oxide charge revealed regions of very high lateral fields near the junction edges for fixed charges in the 2 {times} 10{sup 12}/cm{sup 2} range expected from the capacitor studies which could be responsible for the observed leakage currents.

  5. Sizes of voids as a test for dark matter models

    NASA Astrophysics Data System (ADS)

    Ghigna, Sebastiano; Borgani, Stefano; Bonometto, Silvio A.; Guzzo, Luigi; Klypin, Anatoly; Primack, Joel R.; Giovanelli, Riccardo; Haynes, Martha P.

    1994-12-01

    We use the void probability function (VPF) to study the distribution of galaxies in a volume-limited sub-sample of the Perseus-Pisces survey. We compare observational results with theoretical predictions based on high-resolution N-body simulations for two realizations of the cold + hot dark matter (CHDM) model and for unbiased (b = 1) and biased (b = 1.5) cold dark matter (CDM) models in a 50/h Mpc box. We identify galaxies as peaks of the evolved density field. Overmerged structures are fragmented into individual galaxies so as to reproduce both the correct luminosity function (after assuming M/L values for the resulting galaxy groups) and the two-point correlation function. We also try to reproduce the observational biases of the observational data as best we can. Our main result is that on intermediate 2-8/h Mpc scales the VPF for the standard CHDM model with Omega cold/Omega hot/Omega bar = 0.6/0.3/0.1 exceeds the observational VPF with a high confidence level. CDM models produce smaller VPF, whose shape is independent of the biasing parameter. We verify the robustness of this result against changing the observer position in the simulations and the threshold for galaxy identification.

  6. 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.

  7. Stimulation of intrachromosomal homologous recombination in human cells by electroporation with site-specific endonucleases.

    PubMed Central

    Brenneman, M; Gimble, F S; Wilson, J H

    1996-01-01

    In somatic mammalian cells, homologous recombination is a rare event. To study the effects of chromosomal breaks on frequency of homologous recombination, site-specific endonucleases were introduced into human cells by electroporation. Cell lines with a partial duplication within the HPRT (hypoxanthine phosphoribosyltransferase) gene were created through gene targeting. Homologous intrachromosomal recombination between the repeated regions of the gene can reconstruct a functioning, wild-type gene. Treatment of these cells with the restriction endonuclease Xba I, which has a recognition site within the repeated region of HPRT homology, increased the frequency or homologous recombination bv more than 10-fold. Recombination frequency was similarly increased by treatment with the rare-cutting yeast endonuclease PI-Sce I when a cleavage site was placed within the repeated region of HPRT. In contrast, four restriction enzymes that cut at positions either outside of the repeated regions or between them produced no change in recombination frequency. The results suggest that homologous recombination between intrachromosomal repeats can be specifically initiated by a double-strand break occurring within regions of homology, consistent with the predictions of a model. PMID:8622983

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  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. A preliminary report of phylogenetic diversity of bacterial strains isolated from marine creatures.

    PubMed

    Kurahashi, Midori; Yokota, Akira

    2002-10-01

    Bacterial diversity among marine creatures, especially molluscs, as a source for searching out novel lineages of bacteria, was studied. Marine creatures were collected at the coasts of the Kanto area in Japan. A total of 116 strains of bacteria were isolated from the intestines of 19 species of marine creatures includings molluscs, pisces and protochordata. Partial sequencing of 16S rDNA revealed that most of the isolates belonged to the gamma subclass of the Proteobacteria and Cytophaga-Flavobacterium-Bacteroides group. The BLAST searches revealed that the complete 16S rDNA sequence of 17 strains out of 116 isolates showed less than 94% similarity with 16S rDNA sequences deposited in the database. Four strains out of the 17 isolates belonged to the Rhodobacter group, 8 strains to the Alteromonas group, and the remaining 5 strains to the Cytophaga-Flavobacterium-Bacteroides group. Phylogenetic positions of 6 strains belonging to the Alteromonas group, which were isolated from different marine creatures, were close to each other, and represented a novel 16S rDNA lineage within the gamma subclass of Proteobacteria. Therefore, it may be inferred that these 6 strains belong to a new genus of Proteobacteria. Phylogenetic positions of the other strains are also independent from neighboring taxa, and they were suggested to respectively form a novel lineage. From these results, it is clear that the biodiversity of bacteria in marine creatures is much wider than was previously thought, and unknown microbiological resources are buried in these organisms.

  15. HOW THE FIRST STARS SHAPED THE FAINTEST GAS-DOMINATED DWARF GALAXIES

    SciTech Connect

    Verbeke, R.; Vandenbroucke, B.; Rijcke, S. De

    2015-12-20

    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.

  16. Evaluation of the genotoxic and cytotoxic effects of glyphosate-based herbicides in the ten spotted live-bearer fish Cnesterodon decemmaculatus (Jenyns, 1842).

    PubMed

    Vera-Candioti, Josefina; Soloneski, Sonia; Larramendy, Marcelo L

    2013-03-01

    Mortality, genotoxicity, and cytotoxicity of the 48% glyphosate-based formulations Panzer and Credit(®) were evaluated on Cnesterodon decemmaculatus (Jenyns, 1842) (Pisces, Poeciliidae) under laboratory conditions. Induction of micronuclei (MN) and alterations in the erythrocytes:erythroblasts ratio were employed as end points for genotoxicity and cytotoxicity, respectively. For Panzer(®), mean values of 16.70 and 15.68 mg/L were determined for LC(50) at 24 and 96 h, respectively, and these concentrations reached mean values of 98.50 and 91.73 mg/L for Credit(®). LC(50) values decreased as a negative linear function of Panzer(®) exposure time within the 0-96 h period, but not for Credit(®). LC(50) values indicated that the fish were more sensitive to Panzer(®) than to Credit(®). Both 3.9 and 7.8 mg/L of Panzer(®) increased MN frequency at 48 and 96 h of treatment. When fish were exposed to Credit(®), an increased frequency of MN over control values was found after 96 h for all concentrations assayed, but not after 48 h. No cellular cytotoxicity was found after Panzer(®) and Credit(®) treatment, regardless of both the concentration and the sampling time. Furthermore, our results demonstrated that Panzer(®) and Credit(®) should be considered as glyphosate-based commercial formulations with genotoxic but not cytotoxic effect properties.

  17. 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.

  18. Mitochondrial phylogeny and phylogeography of East African squeaker catfishes (Siluriformes: Synodontis)

    PubMed Central

    Koblmüller, Stephan; Sturmbauer, Christian; Verheyen, Erik; Meyer, Axel; Salzburger, Walter

    2006-01-01

    Background Squeaker catfishes (Pisces, Mochokidae, Synodontis) are widely distributed throughout Africa and inhabit a biogeographic range similar to that of the exceptionally diverse cichlid fishes, including the three East African Great Lakes and their surrounding rivers. Since squeaker catfishes also prefer the same types of habitats as many of the cichlid species, we hypothesized that the East African Synodontis species provide an excellent model group for comparative evolutionary and phylogeographic analyses. Results Our analyses reveal the existence of six major lineages of Synodontis in East Africa that diversified about 20 MYA from a Central and/or West African ancestor. The six lineages show a clear geographic patterning. Two lineages are endemic to Lake Tanganyika (plus one non-endemic representative), and these are the only two Synodontis lineages that diversified further into a small array of species. One of these species is the cuckoo catfish (S. multipunctatus), a unique brood parasite of mouthbrooding haplochromine cichlids, which seems to have evolved in parallel with the radiation of its cichlid host lineage, the Tropheini. We also detect an accelerated rate of molecular evolution in S. multipunctatus, which might be the consequence of co-evolutionary dynamics. Conclusion We conclude that the ancestral lineage of today's East African squeaker catfish fauna has colonized the area before the Great Lakes have formed. This ancestor diversified rapidly into at least six lineages that inhabit lakes and rivers in East Africa. Lake Tanganyika is the only lake harboring a small species flock of squeaker catfishes. PMID:16784525

  19. Holocene evolution of summer winds and marine productivity in the tropical Indian Ocean in response to insolation forcing: data-model comparison

    NASA Astrophysics Data System (ADS)

    Bassinot, F. C.; Marzin, C.; Braconnot, P.; Marti, O.; Mathien-Blard, E.; Lombard, F.; Bopp, L.

    2011-07-01

    The relative abundance of Globigerinoides bulloides was used to infer Holocene paleo-productivity changes on the Oman margin and at the southern tip of India. Today, the primary productivity at both sites reaches its maximum during the summer season, when monsoon winds result in local Eckman pumping, which brings more nutrients to the surface. On a millennium time-scale, however, the % G. bulloides records indicate an opposite evolution of paleo-productivity at these sites through the Holocene. The Oman Margin productivity was maximal at ~9 ka (boreal summer insolation maximum) and has decreased since then, suggesting a direct response to insolation forcing. On the contrary, the productivity at the southern tip of India was minimum at ~9 ka, and strengthened towards the present. Paleo-reconstructions of wind patterns, marine productivity and foraminifera assemblages were obtained using the IPSL-CM4 climate model coupled to the PISCES marine biogeochemical model and the FORAMCLIM ecophysiological model. These reconstructions are fully coherent with the marine core data. They confirm that the evolution of particulate export production and foraminifera assemblages at our two sites were directly linked with the strength of the upwelling. Model simulations at 9 ka and 6 ka BP show that the relative evolution between the two sites since the early Holocene can be explained by the weakening but also the southward shift of monsoon winds over the Arabian Sea during boreal summer.

  20. 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.

  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. Measuring the neutral hydrogen mass of galaxy cluster A262

    NASA Astrophysics Data System (ADS)

    Hassan, Mohd Shaiful Rizal; Abidin, Zamri Zainal; Ibrahim, Zainol Abidin; Ibrahim, Ungku Ferwani Salwa Ungku; Hashim, Norsiah

    2013-05-01

    The total neutral hydrogen mass of galaxy cluster, MHI is measured using spectra taken by a 7 meter single dish radio telescope at Jodrell Bank Observatory. This have been done by using a concept introduced by R. A. Bettye which is make use of small single radio telescope for findings MHI as a whole. MHI is calculated by using simple relationship involving parameter distance of the object from the observer, D and radiated flux of continuum radio source, Sν. A262 is chosen as our test subject since it is compatible with the capability of our instrument. It is a spiral rich galaxy cluster and a fragment of Pisces in the Perseus supercluster, located approximately at 62 - 77 Mpc. It is a part of Local Group Supercluster that is centered at giant elliptical galaxy, NGC 708, and it is also called `cluster dominant' because of its strongly X-ray source concentrated. A262 is chosen as our candidate in this study because of its relatively low redshift, z = 0.0156, observed in 21 cm emission as their tracer. We calculate MHI of A262 according to some analysis from previous studies. Preliminary detection of A262 showed some degree of success.

  4. Fishing for gaps in science: a bibliographic analysis of Brazilian freshwater ichthyology from 1986 to 2005.

    PubMed

    Azevedo, P G; Mesquita, F O; Young, R J

    2010-06-01

    To investigate Brazilian freshwater ichthyology, from 1986 to 2005, a bibliometric analysis was conducted using abstracts downloaded from The Web of Science database searching for the keywords 'fish', 'pisces', 'teleostei' and the address field having the word 'Brazil'. The results of this study showed that Brazilian freshwater ichthyology publications have been increasing during the study period. This process is a consequence of a series of investments that the Brazilian Government has made. Furthermore, data analyses identified scientific areas where there was a lack of scientific knowledge (e.g. studies of species threatened with extinction and certain hydrologic basins). Research institutions from the north-east and northern region of Brazil had the lowest participation in scientific productivity, which was a reflection of their regions poorer economic situation. This study showed that scientific productivity in Brazilian ichthyology was a direct reflection of state investment in research. Furthermore, data in this study follow expected statistical probabilities, for example, fishes from the most diverse families were the most studied. Thus, the study shows that great progress has been made by Brazilian ichthyologists in the last 20 years; however, due to the mega diversity of fishes in Brazil, much remains to be done if many species are to become known to science and to be saved from extinction. This it seems will depend on continued and further investment by Brazilian Government funding agencies, as Brazilian ichthyologists have demonstrated their capacity to generate high quality information about their study species.

  5. VizieR Online Data Catalog: SFR IRAS 05137+3919 star and jet multiplicity (Cesaroni+, 2015)

    NASA Astrophysics Data System (ADS)

    Cesaroni, R.; Massi, F.; Arcidiacono, C.; Beltran, M. T.; Persi, P.; Tapia, M.; Molinari, S.; Testi, L.; Busoni, L.; Riccardi, A.; Boutsia, K.; Bisogni, S.; McCarthy, D.; Kulesa, C.

    2015-11-01

    Near-IR images were taken in the night of December 12, 2009 with LUCI at the Large Binocular Telescope (Mount Graham, Arizona), through the standard broad-band filters H (λc=1.653um) and Ks (λc=2.163um), and the narrow-band filters FeII (λc=1.646um, including the [FeII] 1.64-um line) and H2 (λc=2.122um, including the H2v=1-0 S(1) line at 2.12um). Data were also collected on October 9 and 12, 2013, using the PISCES Near Infrared Camera installed at the focal plane of the First Light Adaptive Optics system of the Large Binocular Telescope. Ground-based diffraction-limited mid-infrared images at 8.9, 9.9, 12.7, and 18.7um of IRAS 05137+3919 were taken on the night of November 9, 2006 with the mid-infrared camera CID mounted on the 2.1m telescope of the Observatorio Astronomico Nacional at San Pedro Martir, Baja California, Mexico. (5 data files).

  6. 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.

  7. 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.

  8. [Variations of the infracommuity during the ontogeny of Chromis cyanea (Perciformes: Pomcentride) in the North coast of Havana, Cuba].

    PubMed

    Fernández Osorio, Ramón Alexis; Corrada Wong, Raúl Igor; Armenteros, Maickel

    2015-09-01

    The infracommunty or parasites or unromis cyanea (Pisces: Pomacentridae) was studied along the ontogenetic development in the North coast of Havana, Cuba. The objectives were: a- to prove that the core species appears before the strange and stochastic species and they are responsible for the structure in the infracommunity, b- to determine if there is a relationship among the ecological describers of the parasitic infracommunity with the total length. A total of 278 specimens of C. cyanea were captured during the dry season (April) of 2010. The body size range was from 1.5 to 11.5 cm including juvenile and adults. We collected 2 861 parasite specimens belonging to 20 taxa: Crustacea (5), Nematoda (5), Trematoda (4), Cestoda (2), Monogenea (2), Turbellaria (1) and Ciliophora (1). The taxa Tetraphyllidea and Anilocra chromis constituted the core of the parasitic infracommunity. The sequence of appearance and persistence of these taxa during the ontogenetic development, supported the hypothesis of the core species. The changes in the infracommunity, from 6 cm body size, could be the result of an accumulative effect combined with changes of the diet that caused the ingestion of new parasite infective stages. We concluded that the ontogenetic development of C. cyanea constitutes an important variable in the formation of the parasitic infracommunity.

  9. 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.

  10. 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.

  11. Be I and Be II spectroscopy in divertor plasma relevant conditions

    NASA Astrophysics Data System (ADS)

    Nishijima, D.; Doerner, R. P.; Seraydarian, R. P.

    2013-07-01

    Intensity ratios of various Be I and Be II lines measured in Be-seeded D and He plasmas in the PISCES-B linear divertor plasma simulator are compared with the corresponding ratios of the photon emissivity coefficient, PEC, calculated by ADAS. Agreement of measured intensity ratios with calculated PEC ratios is satisfactory within a factor of ˜2 for both Be I and Be II. It is proposed that a Be I line ratio of 234.8 nm/265.0 nm and a Be II line ratio of 467.3 nm/313.1 nm can be used to estimate the electron temperature, while a 265.0 nm/332.1 nm Be I line ratio is sensitive to the electron density. Further, S/XB values of a Be I line at 457.3 nm were experimentally determined from a ratio of the sputtered Be flux to the emission intensity. Measured values are systematically lower than calculated ADAS values, which may be explained by the increased sputtering yield of redeposited Be atoms.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. [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).

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. Chlorpyrifos-based insecticides induced genotoxic and cytotoxic effects in the ten spotted live-bearer fish, Cnesterodon decemmaculatus (Jenyns, 1842).

    PubMed

    Vera-Candioti, Josefina; Soloneski, Sonia; Larramendy, Marcelo L

    2014-12-01

    Mortality, genotoxicity, and cytotoxicity of the 48% chlorpyrifos (CPF)-based formulations Lorsban* 48E(®) and CPF Zamba(®) were evaluated on Cnesterodon decemmaculatus (Jenyns, 1842) (Pisces, Poeciliidae) under laboratory conditions. Induction of micronucleus (MN) and alterations in the erythrocyte/erythroblast frequencies were employed as end points for genotoxicity and cytotoxicity, respectively. For Lorsban* 48E(®) , mean values of 0.13 and 0.03 mg/L were determined for LC50 at 24 and 96 h, respectively, and these concentrations reached mean values of 0.40 and 0.21 mg/L for CPF Zamba(®) . Mortality values increased as a positive linear function of the CPF Zamba(®) concentrations, but not for Lorsban* 48E(®) concentrations. There was no significant relationship between mortality and exposure time within the 0-96 h period for both formulations. LC50 values indicated that the fish were seven fold more sensitive to Lorsban* 48E(®) than to CPF Zamba(®) . Lorsban* 48E(®) within the concentration range of 0.008-0.025 mg/L increased MN frequency at both 48 and 96 h of treatment. Similar results were also observed when fish were exposed to 0.052-0.155 mg/L of CPF Zamba(®) , regardless of the exposure time. Cellular cytotoxicity was found after Lorsban* 48E(®) and CPF Zamba(®) treatments for all concentrations and time exposures, estimated by a decrease in the frequency of mature erythrocytes and a concomitant enhanced frequency of erythroblasts in circulating blood. Furthermore, our results demonstrated that Lorsban* 48E(®) and CPF Zamba(®) should be considered as CPF-based commercial formulations with marked genotoxic and cytotoxic properties.

  4. Evaluation of the genotoxicity of a herbicide formulation containing 3,6-dichloro-2-metoxybenzoic acid (dicamba) in circulating blood cells of the tropical fish Cnesterodon decemmaculatus.

    PubMed

    Ruiz de Arcaute, C; Soloneski, S; Larramendy, M L

    2014-10-01

    Acute toxicity and genotoxicity of the dicamba-based commercial herbicide formulation Banvel(®) were evaluated on Cnesterodon decemmaculatus (Pisces, Poeciliidae) exposed under laboratory conditions. A lethal effect was used as the end point for mortality, whereas frequency of micronuclei (MNs) and DNA single-strand breaks evaluated by the single cell gel electrophoresis assay were employed as end points for genotoxicity. Mortality studies revealed an LC50 96 h value of 1639 mg/L (range, 1471-1808) of dicamba. Furthermore, behavioral changes, e.g., gathering at the bottom of the aquarium, slowness in motion, abnormal swimming, and slow reaction, were observed. Whereas increased frequency of MNs was observed when 1229 mg/L dicamba was assayed for 48 h, no induction of MNs was observed in fish exposed to the herbicide for 96 h, regardless of the concentration of dicamba. Furthermore, other nuclear abnormalities, i.e., binucleated cells and lobed and notched nuclei, were induced in fish exposed for 48 h but not 96 h. Increase in the genetic damage index was observed in those treatments (lasting for both 48 and 96 h) within the 410-1229 mg/L dicamba concentration-range. This study represents the first evidence of acute lethal and sublethal effects exerted by dicamba on a piscine species native to Argentina. The results could indicate that dicamba-based formulation Banvel(®) is the less toxic emerging pollutant reported so far for C. decemmaculatus. Finally, our findings highlight the properties of this herbicide that jeopardize nontarget living species exposed to this agrochemical.

  5. 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 96 h value of 1008 mg/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 252-756 mg/L range increased the frequency of MNs in fish exposed for both 48 and 96 h. Whereas blebbed nuclei were induced in treatments lasting for 48 and 96 h, notched nuclei were only induced in fish exposed for 96 h. 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 252-756 mg/L range increased the genetic damage index in treatments lasting for either 48 and 96 h. 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.

  6. Sensitivity of the marine carbonate cycle to atmospheric CO2

    NASA Astrophysics Data System (ADS)

    Gangstø, R.; Joos, F.; Gehlen, M.

    2010-09-01

    Ocean acidification might reduce the ability of calcifying plankton to produce and maintain their shells of calcite, or of aragonite, the more soluble form of CaCO3. In addition to possibly large biological impacts, reduced CaCO3 production corresponds to a negative feedback on atmospheric CO2. In order to explore the sensitivity of the ocean carbon cycle to increasing concentrations of atmospheric CO2, we use the new biogeochemical Bern3D/PISCES model. The model reproduces the large scale distributions of biogeochemical tracers. With a range of sensitivity studies, we explore the effect of (i) using different parameterizations of CaCO3 production fitted to available laboratory and field experiments, of (ii) letting calcite and aragonite be produced by auto- and heterotrophic plankton groups, and of (iii) using carbon emissions from the range of the most recent IPCC Representative Concentration Pathways (RCP). Under a high-emission scenario, the CaCO3 production of all the model versions decreases from ~1 Pg C yr-1 to between 0.36 and 0.82 Pg C yr-1 by the year 2100. By the year 2500, the ratio of open water CaCO3 dissolution to production stabilizes at a value that is 30-50% higher than at pre-industrial times when carbon emissions are set to zero after 2100. Despite the wide range of parameterizations, model versions and scenarios included in our study, the changes in CaCO3 production and dissolution resulting from ocean acidification provide only a small feedback on atmospheric CO2 of 1-11 ppm by the year 2100.

  7. 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

  8. 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.

  9. 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

  10. A revision of the haploporinae nicoll, 1914 (digenea: haploporidae) from mullets (mugilidae): Saccocoelium Looss, 1902.

    PubMed

    Blasco-Costa, Isabel; Montero, Francisco E; Gibson, David I; Balbuena, Juan Antonio; Raga, Juan Antonio; Kostadinova, Aneta

    2009-03-01

    Saccocoelium Looss, 1902 is revised and a key to its recognised species is presented. S. obesum Looss, 1902 (type-species) and S. tensum Looss, 1902 are redescribed based on material from Liza spp. (Pisces: Mugilidae) in Spanish Mediterranean and, in the case of the former, Bulgarian Black Sea waters. Two new species, S. cephali n. sp. and S. currani n. sp., are described from Mugil cephalus L. in Spanish Mediterranean waters. S. gohari Ramadan, Saoud, Ashour & Mansour, 1989b is recognised and commented upon. Lecithobotrys helmymohamedi Ramadan, Saoud, Ashour & Mansour, 1989a, S. portsaidensis El-Shahawi, El-Gindy, Imam & Al-Bassel, 1992, S. saoudi El-Shahawi, El-Gindy, Imam & Al-Bassel, 1992, Neosaccocoelium aegyptiacus El-Shahawi, El-Gindy, Imam & Al-Bassel, 1992 are considered to be synonyms of S. tensum and Neosaccocoelium El-Shahawi, El-Gindy, Imam & Al-Bassel, 1992 a synonym of Saccocoelium. S. obesum, S. tensum and the two new species are compared morphometrically and distinguished by univariate and multivariate analyses. Lecithobotrys mugilis Rekharani & Madhavi, 1985 is transferred to Unisaccus Martin, 1973 as U. mugilis (Rekharani & Madhavi, 1985) n. comb., and Lecithobotrys sprenti Martin, 1973 [= Saccocoelium sprenti (Martin, 1973) Overstreet & Curran, 2005] is transferred to Unisaccus as U. sprenti (Martin, 1973) n. comb. S. megasacculum Liu, Wang, Peng, Yu & Yang, 2004 is transferred to Elliptobursa Wu, Lu & Zhu, 1996 as E. megasacculum (Liu, Wang, Peng, Yu & Yang, 2004) n. comb. S. tripathi Dutta, 1995 (syn. Saccocoelium tripathi Datta & Manna, 1998) is considered to be a species inquirenda.

  11. 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.

  12. Sensitivity of air-sea CO2-exchange and calcite saturation depth to the remineralization depth of marine particulate organic and inorganic carbon

    NASA Astrophysics Data System (ADS)

    Schneider, B.; Bopp, L.; Gehlen, M.

    2009-04-01

    The present study addresses the question of what would happen to air-sea CO2 exchange and the depth of the calcite saturation horizon (CSH) if the remineralization depth of particulate organic and inorganic carbon (POC, PIC) was changing. Therefore, a biogeochemical ocean circulation model (PISCES) was run with four different parameterizations for vertical particle fluxes, starting from the same initial conditions. Particle fluxes undergo strong changes induced by a combination of the respective mechanistic formulation of the vertical particle flux and the resulting ecosystem response. Reorganizations in dissolved properties are caused by (i) changed fluxes of POC and PIC; (ii) advection; (iii) air-sea CO2 exchange (DIC). The results show that the more (less) efficient the vertical transport of POC (PIC) from the surface toward depth, the lower the surface ocean pCO2, the higher the air-sea CO2 flux, and the stronger the increase in the oceanic inventory of DIC, and vice versa. Consequently, in one experiment the ocean is turning into a CO2 source to the atmosphere, in two cases it becomes a weak sink and in one simulation it turns into a strong sink. Surprisingly, results for changes in the CSH are more similar among the simulations at larger scale with a general deepening in the North Pacific and a shoaling elsewhere. In most areas the readjustment of the CSH is controlled by DIC and alkalinity acting both towards the simulated CSH shifts, however, in some cases DIC (alkalinity) is overcompensating for an effect that would occur due to changes in alkalinity (DIC), alone. In detail, the differences found between the experiments can be well explained by the respective particle flux responses. The current study shows that reorganizations in the vertical flux of particulate matter in the ocean may have immediate and longer-term effects on the marine carbon cycle which could potentially feedback on the climate system.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. A non-parametric model for the cosmic velocity field

    NASA Astrophysics Data System (ADS)

    Branchini, E.; Teodoro, L.; Frenk, C. S.; Schmoldt, I.; Efstathiou, G.; White, S. D. M.; Saunders, W.; Sutherland, W.; Rowan-Robinson, M.; Keeble, O.; Tadros, H.; Maddox, S.; Oliver, S.

    1999-09-01

    We present a self-consistent non-parametric model of the local cosmic velocity field derived from the distribution of IRAS galaxies in the PSCz redshift survey. The survey has been analysed using two independent methods, both based on the assumptions of gravitational instability and linear biasing. The two methods, which give very similar results, have been tested and calibrated on mock PSCz catalogues constructed from cosmological N-body simulations. The denser sampling provided by the PSCz survey compared with previous IRAS galaxy surveys allows an improved reconstruction of the density and velocity fields out to large distances. The most striking feature of the model velocity field is a coherent large-scale streaming motion along the baseline connecting Perseus-Pisces, the Local Supercluster, the Great Attractor and the Shapley Concentration. We find no evidence for back-infall on to the Great Attractor. Instead, material behind and around the Great Attractor is inferred to be streaming towards the Shapley Concentration, aided by the compressional push of two large nearby underdensities. The PSCz model velocities compare well with those predicted from the 1.2-Jy redshift survey of IRAS galaxies and, perhaps surprisingly, with those predicted from the distribution of Abell/ACO clusters, out to 140h^-1Mpc. Comparison of the real-space density fields (or, alternatively, the peculiar velocity fields) inferred from the PSCz and cluster catalogues gives a relative (linear) bias parameter between clusters and IRAS galaxies of b_c=4.4+/-0.6. Finally, we implement a likelihood analysis that uses all the available information on peculiar velocities in our local Universe to estimate beta_Omega 0 0.6 b_0.6 -0.15 +0.22 (1sigma), where b is the bias parameter for IRAS galaxies.

  18. Photometric and spectroscopic study of the ultra-faint Milky Way satellite Pegasus III

    NASA Astrophysics Data System (ADS)

    Kim, Dongwon; Jerjen, Helmut; Geha, Marla C.; Chiti, Anirudh; Milone, Antonino; Da Costa, Gary S.; Mackey, Dougal; Frebel, Anna; Conn, Blair

    2017-01-01

    Pegasus III (Peg III) is one of the few known ultra-faint dwarf (UFD) satellite galaxies in the outer halo (R >150 kpc) of the Milky Way (MW). We present results from a recent study of Peg III using Magellan/IMACS and Keck/DEIMOS. Our newly-measured structural parameters confirm that Peg III is large (rh = 53±14pc), elongated (∈ = 0.38+0.22-0.38 ), and faint (MV=-3.4±0.4 mag) — indicative of its nature as a dwarf rather than a globular cluster. In the color-magnitude diagram, Peg III is well described by an old (>12Gyr) and metal-poor ([Fe/H]<-2.0 dex) stellar population at a heliocentric distance of 215±12 kpc. Using spectroscopic measurements of individual stars, we identify seven kinematic members of Peg III. The Ca II triplet lines of the brightest members verify that Peg III indeed contains stars with metallicity as low as [Fe/H]=-2.55±0.15 dex. The systemic velocity and velocity dispersion of Peg III are -222.9±2.6 km/s and 5.4+3.0-2.5 km/s, respectively. The inferred dynamical mass within the half-light radius of 1.4+3.0-1.1×106M⊙, and the mass-to-light ratio of M/LV = 1470+5660-1240M⊙/L⊙ provide further evidence that Peg III is a bona fide UFD. Peg III and another distant UFD Pisces II lie relatively close to each other (△dspatial=43±19 kpc) and share similar systemic radial velocities (△vGSR=12.3±3.7 km/s), which suggests that they may share a common origin.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. Acanthocephalus amini n. sp. (Acanthocephala: Echinorhynchidae) from the freshwater fish Cichlasoma urophthalmus (Günther) (Cichlidae) in Mexico.

    PubMed

    Salgado-Maldonado, Guillermo; Novelo-Turcotte, María Teresa

    2009-07-01

    Acanthocephalus amini n. sp. (Palaeacanthocephala: Echinorhynchidae) is described from the intestine of Cichlasoma urophthalmus (Günther) (Pisces: Cichlidae) collected in the Río Champotón, a river in Campeche State, Mexico. It is the fourth species of Acanthocephalus Koelreuther, 1771 described from North American freshwater fishes, although two other species are known from South America. The new species is distinguished from other members of Acanthocephalus by features of its trunk, which is small, clavate, slightly expanded medially and bluntly pointed posteriorly. It is further distinguished by having a cylindrical proboscis armed with 13-14 longitudinal rows of 11-12 stout hooks; the apical and medial proboscis hooks are almost uniform in size and shape, decreasing in size towards the base; the posteriormost hooks are smaller, straighter and more slender than the anterior and middle hooks; and the lateral rows of hooks are more widely spaced, forming a conspicuous longitudinal area devoid of hooks. Furthermore, the lemnisci are saccate and shorter than the proboscis receptacle; and the neck is very short with a thick collar of trunk tegument, which encircles the base of proboscis. In males, the testes are in the middle third of trunk, diagonal, spherical and small relative to the body size, and there are six clavate cement glands. In females, the uterus forms a conspicuous, elongate, cylindrical egg reservoir. The new species is most similar to A. alabamensis Amin & Williams, 1983, but can be distinguished by its swollen, clavate trunk, the largest proboscis hooks being present apically and medially, smaller testes, a shorter male reproductive system relative to body size and females with a prominent uterus. They have different hosts and geographical distribution. The new species can be differentiated from Brasacanthus sphoeroides Thatcher, 2001, a similar species in a monotypic echinorhynchid genus, because the latter is larger, has smaller proboscis hooks

  5. Neoechinorhynchus (Neoechinorhynchus) chimalapasensis n. sp. (Acanthocephala: Neoechinorhynchidae) from the freshwater fish Awaous banana (Valenciennes) (Gobiidae) in Mexico.

    PubMed

    Salgado-Maldonado, Guillermo; Caspeta-Mandujano, Juan Manuel; Martínez-Ramírez, Emilio

    2010-03-01

    Neoechinorhynchus (Neoechinorhynchus) chimalapasensis n. sp. (Eoacanthocephala: Neoechinorhynchidae) is described from the intestine of Awaous banana (Valenciennes) (Pisces: Gobiidae) collected in the Río Negro, a tributary in the upper Río Coatzacoalcos basin, Santa María Chimalapa, Oaxaca State, Mexico. It is the third species of Neoechinorhynchus Stiles & Hassall, 1905 described from Mexican freshwater fishes, although 36 other species are known from freshwater fishes in the Americas. Like four other species of Neoechinorhynchus from freshwater fishes in North America and Mexico, N. (N.) limi Muzzall & Buckner, 1982, (N.) rutili (Müller, 1780) Stiles & Hassall, 1905, N. (N.) salmonis Ching, 1984 and N. (N.) roseus Salgado-Maldonado, 1978, males and females of the new species are less than 20 mm in length, lack conspicuous sexual dimorphism in size, have a small proboscis of about 0.1 mm in length with the largest hooks being the anteriormost, about 30-90 microm in length and of equal size, and have subequal lemnisci, larger than the proboscis receptacle but still relatively short and, in males, generally restricted to a position considerably anterior to the testes. The new species is closest to N. (N.) roseus, but it is distinguished from it by having: (1) a slightly larger cylindrical proboscis with almost parallel sides versus a globular proboscis with a rounded tip which is shorter and somewhat wider in N. (N.) roseus; (2) smaller but robust anterior proboscis hooks that do not reach the equatorial level or extend beyond the hooks of the middle circle as in N. (N.) roseus; and (3) the female gonopore situated ventrally subterminal, as opposed to being a significant distance anteriorly to the posterior extremity in N. (N.) roseus.

  6. Holocene evolution of summer winds and marine productivity in the tropical Indian Ocean in response to insolation forcing: data-model comparison

    NASA Astrophysics Data System (ADS)

    Bassinot, F. C.; Marzin, C.; Braconnot, P.; Marti, O.; Mathien-Blard, E.; Lombard, F.; Bopp, L.

    2011-02-01

    The relative abundance of Globigerinoides bulloides was used to infer Holocene paleo-productivity changes at ODP Site 723 (19°03' N, 57°37' E; Oman Margin) and core MD77-191 (07°30' N, 76°43' E; Southern tip of India). Today, the primary productivity at both sites peaks during the summer season, when monsoon winds result in local Eckman pumping, which brings more nutrients to the surface. On a millennium time-scale, however, the % G.~bulloides records indicate an opposite evolution of paleo-productivity at these sites through the Holocene. The Oman Margin productivity was maximal at ~9 ka (boreal summer insolation maximum) and decreased since then, suggesting a direct response to insolation forcing. On the opposite, the productivity at the southern tip of India was minimum at ~9 ka, and strengthened towards the present. Paleo-reconstructions of wind patterns, marine productivity and foraminifera assemblages were obtained using the IPSL-CM4 climate model coupled to the PISCES marine biogeochemical model and the FORAMCLIM ecophysiological model. These reconstructions are fully coherent with the marine core data. They confirm that the evolution of particulate export production and foraminifera assemblages at our two sites have been directly linked with the strength of the upwelling. Model simulations at 9 ka and 6 ka BP show that the relative evolution between the two sites since the early Holocene can be explained by the weakening but also the southward shift of monsoon winds over the Arabian sea during boreal summer.

  7. Evidence for the Stepwise Stress Model: Gambusia holbrooki and Daphnia magna under acid mine drainage and acidified reference water stress.

    PubMed

    Gerhardt, Almut; Janssens de Bisthoven, Luc; Soares, Amadeu M V

    2005-06-01

    The Stepwise Stress Model (SSM) states that a cascade of regulative behavioral responses with different intrinsic sensitivities and threshold values offers increased behavioral plasticity and thus a wider range of tolerance for environmental changes or pollutant exposures. We tested the SSM with a widely introduced fish Gambusia holbrooki (Girard) (Pisces, Poeciliidae) and the standard laboratory test species Daphnia magna Straus (Crustacea, Daphniidae). The stress was simulated by short-term exposure to acid mine drainage (AMD) and to acidified reference water (ACID). Recording of behavioral responses with the multispecies freshwater biomonitor (MFB) generated continuous time-dependent dose-response data that were modeled in three-dimensional (3D) surface plots. Both the pH-dependent mortalities and the strong linear correlations between pH and aqueous metals confirmed the toxicity of the AMD and ACID gradients, respectively, for fish and Daphnia, the latter being more sensitive. AMD stress at pH < or = 5.5 amplified circadian rhythmicity in both species, while ACID stress did so only in G. holbrooki. A behavioral stepwise stress response was found in both species: D. magna decreased locomotion and ventilation (first step) (AMD, ACID), followed by increased ventilation (second step) (AMD). G. holbrooki decreased locomotion (first step) (AMD, ACID) and increased ventilation at intermediate pH levels (second step) (AMD). Both species, although from different taxonomic groups and feeding habits, followed the SSM, which might be expanded to a general concept for describing the behavioral responses of aquatic organims to pollution. Stepwise stress responses might be applied in online biomonitors to provide more sensitive and graduated alarm settings, hence optimizing the "early warning" detection of pollution waves.

  8. 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.

  9. 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.

  10. Sublethal toxicity of esbiothrin relationship with total antioxidant status and in vivo genotoxicity assessment in fish (Cyprinus carpio L., 1758) using the micronucleus test and comet assay.

    PubMed

    Selvi, Mahmut; Cavaş, Tolga; Cağlan Karasu Benli, A; Koçak Memmi, Burcu; Cinkılıç, Nilüfer; Dinçel, Aylin Sepici; Vatan, Ozgür; Yılmaz, Dilek; Sarıkaya, Rabia; Zorlu, Tolga; Erkoç, Figen

    2013-11-01

    Esbiothrin, synthetic pyrethroid with quick activity against insects, is widely used against household pests and in public health. Despite widespread use, data on ecotoxicity and genotoxic effects are extremely scarce. The aim of the present study is to evaluate the genotoxic potential of esbiothrin on a model fish species Cyprinus carpio L., 1758 (Pisces: Cyprinidae, koi) using the micronucleus test and comet assay in peripheral blood erythrocytes. Effects of two sublethal exposure concentrations on plasma total antioxidant status (TAS mmol/L), and Hct values were examined. On the basis of the 96 h LC50 data from U.S. EPA ecotox database (32 μg/L) two sublethal exposure concentrations (5 and 10 μg/L) were used together with ethyl methanesulfonate (EMS) (5 mg/L) as positive control. Five fish were used for each dose/duration group (24, 48, and 72 h) under controlled laboratory conditions. The fish showed behavioral changes at the higher dose. Plasma TAS (mmol/L) levels decreased in 24 h; an increase was observed slightly for 48 and obviously for 72 h in both exposure doses. Similarly, hematocrit (Hct) values differed between exposure duration but no significant differences in mean values were found between groups of the same exposure time. The general trend was a rise after 48 h, which decreased afterwards. Our results revealed significant increases in the frequencies of micronuclei and levels of DNA strand breaks and thus demonstrated the genotoxic potential of this pesticide on fish, a nontarget organism of the aquatic ecosystem. To our knowledge this is the first study to report observable genotoxic effects of esbiothrin on fish.

  11. The NSF Undergraduate ALFALFA Team: Partnering with Arecibo Observatory to Offer Undergraduate and Faculty Extragalactic Radio Astronomy Research Opportunities

    NASA Astrophysics Data System (ADS)

    Ribaudo, Joseph; Koopmann, Rebecca A.; Haynes, Martha P.; Balonek, Thomas J.; Cannon, John M.; Coble, Kimberly A.; Craig, David W.; Denn, Grant R.; Durbala, Adriana; Finn, Rose; Hallenbeck, Gregory L.; Hoffman, G. Lyle; Lebron, Mayra E.; Miller, Brendan P.; Crone-Odekon, Mary; O'Donoghue, Aileen A.; Olowin, Ronald Paul; Pantoja, Carmen; Pisano, Daniel J.; Rosenberg, Jessica L.; Troischt, Parker; Venkatesan, Aparna; Wilcots, Eric M.; ALFALFA Team

    2017-01-01

    The NSF-sponsored Undergraduate ALFALFA (Arecibo Legacy Fast ALFA) Team (UAT) is a consortium of 20 institutions across the US and Puerto Rico, founded to promote undergraduate research and faculty development within the extragalactic ALFALFA HI blind survey project and follow-up programs. The objective of the UAT is to provide opportunities for its members to develop expertise in the technical aspects of observational radio spectroscopy, its associated data analysis, and the motivating science. Partnering with Arecibo Observatory, the UAT has worked with more than 280 undergraduates and 26 faculty to date, offering 8 workshops onsite at Arecibo (148 undergraduates), observing runs at Arecibo (69 undergraduates), remote observing runs on campus, undergraduate research projects based on Arecibo science (120 academic year and 185 summer projects), and presentation of results at national meetings such as the AAS (at AAS229: Ball et al., Collova et al., Davis et al., Miazzo et al., Ruvolo et al, Singer et al., Cannon et al., Craig et al., Koopmann et al., O'Donoghue et al.). 40% of the students and 45% of the faculty participants have been women and members of underrepresented groups. More than 90% of student alumni are attending graduate school and/or pursuing a career in STEM. 42% of those pursuing graduate degrees in Physics or Astronomy are women.In this presentation, we summarize the UAT program and the current research efforts of UAT members based on Arecibo science, 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 (APPSS). This work has been supported by NSF grants AST-0724918/0902211, AST-075267/0903394, AST-0725380, AST-121105, and AST-1637339.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  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. Sensitivity of pelagic calcification to ocean acidification

    NASA Astrophysics Data System (ADS)

    Gangstø, R.; Joos, F.; Gehlen, M.

    2011-02-01

    Ocean acidification might reduce the ability of calcifying plankton to produce and maintain their shells of calcite, or of aragonite, the more soluble form of CaCO3. In addition to possibly large biological impacts, reduced CaCO3 production corresponds to a negative feedback on atmospheric CO2. In order to explore the sensitivity of the ocean carbon cycle to increasing concentrations of atmospheric CO2, we use the new biogeochemical Bern3D/PISCES model. The model reproduces the large scale distributions of biogeochemical tracers. With a range of sensitivity studies, we explore the effect of (i) using different parameterizations of CaCO3 production fitted to available laboratory and field experiments, of (ii) letting calcite and aragonite be produced by auto- and heterotrophic plankton groups, and of (iii) using carbon emissions from the range of the most recent IPCC Representative Concentration Pathways (RCP). Under a high-emission scenario, the CaCO3 production of all the model versions decreases from ~1 Pg C yr-1 to between 0.36 and 0.82 Pg C yr-1 by the year 2100. The changes in CaCO3 production and dissolution resulting from ocean acidification provide only a small feedback on atmospheric CO2 of -1 to -11 ppm by the year 2100, despite the wide range of parameterizations, model versions and scenarios included in our study. A potential upper limit of the CO2-calcification/dissolution feedback of -30 ppm by the year 2100 is computed by setting calcification to zero after 2000 in a high 21st century emission scenario. The similarity of feedback estimates yielded by the model version with calcite produced by nanophytoplankton and the one with calcite, respectively aragonite produced by mesozooplankton suggests that expending biogeochemical models to calcifying zooplankton might not be needed to simulate biogeochemical impacts on the marine carbonate cycle. The changes in saturation state confirm previous studies indicating that future anthropogenic CO2 emissions may

  20. 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

  1. 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

  2. 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.

  3. Mid-Holocene and last glacial maximum climate simulations with the IPSL model: part II: model-data comparisons

    NASA Astrophysics Data System (ADS)

    Kageyama, Masa; Braconnot, Pascale; Bopp, Laurent; Mariotti, Véronique; Roy, Tilla; Woillez, Marie-Noëlle; Caubel, Arnaud; Foujols, Marie-Alice; Guilyardi, Eric; Khodri, Myriam; Lloyd, James; Lombard, Fabien; Marti, Olivier

    2013-05-01

    The climates of the mid-Holocene (MH, 6,000 years ago) and the Last Glacial Maximum (LGM, 21,000 years ago) have been extensively documented and as such, have become targets for the evaluation of climate models for climate contexts very different from the present. In Part 1 of the present work, we have studied the MH and LGM simulations performed with the last two versions of the IPSL model: IPSL_CM4, run for the PMIP2/CMIP3 (Coupled Model Intercomparion Project) projects and IPSL_CM5A, run for the most recent PMIP3/CMIP5 projets. We have shown that not only are these models different in their simulations of the PI climate, but also in their simulations of the climatic anomalies for the MH and LGM. In the Part 2 of this paper, we first examine whether palaeo-data can help discriminate between the model performances. This is indeed the case for the African monsoon for the MH or for North America south of the Laurentide ice sheet, the South Atlantic or the southern Indian ocean for the LGM. For the LGM, off-line vegetation modelling appears to offer good opportunities to distinguish climate model results because glacial vegetation proves to be very sensitive to even small differences in LGM climate. For other cases such as the LGM North Atlantic or the LGM equatorial Pacific, the large uncertainty on the SST reconstructions, prevents model discrimination. We have examined the use of other proxy-data for model evaluation, which has become possible with the inclusion of the biogeochemistry morel PISCES in the IPSL_CM5A model. We show a broad agreement of the LGM-PI export production changes with reconstructions. These changes are related to the mixed layer depth in most regions and to sea-ice variations in the high latitudes. We have also modelled foraminifer abundances with the FORAMCLIM model and shown that the changes in foraminifer abundance in the equatorial Pacific are mainly forced by changes in SSTs, hence confirming the SST-foraminifer abundance relationship

  4. 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

  5. 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

  6. Insights into the ecological effects of deep ocean CO2 enrichment: The impacts of natural CO2 venting at Loihi seamount on deep sea scavengers

    NASA Astrophysics Data System (ADS)

    Vetter, Eric W.; Smith, Craig R.

    2005-09-01

    Hydrothermal vents on Loihi seamount near Hawaii emit 5000-100,000 t/yr of CO2 at water depths of 1200-1300 m, yielding CO2 concentrations as high as 418 mol/m3. Because CO2 is the dominant toxic component of these vent fluids, Loihi provides an extraordinary setting in which to explore the effects of sustained CO2 enrichment on deep sea organisms and ecological processes. We used the Pisces IV submersible to manipulate baited traps and bait parcels in Loihi's plume to explore the effects of elevated CO2 on the feeding and behavior of typical deep sea scavengers. Necrophagous lysianassid amphipods (Eurythenes cf. obesus) and synaphobranchid eels were unusually abundant in the vicinity of Loihi's vents, suggesting that the CO2-rich plumes rising above Loihi may enhance the flux of carrion to the deep sea floor. Amphipods exposed to diluted vent waters with a mean pH of 6.3 (minimum 5.7) and temperature of 5.0°C became very active within seconds and then became narcotized over timescales of 2-15 min. Following 60 min of plume exposure, all amphipods revived within 30 min of removal from the plume and remained active until warmed to 10°C during submersible ascent into ocean surface waters. Open bait parcels placed in similar CO2 plumes were avoided by amphipods and fish, suggesting that they could detect either the elevated CO2 concentrations or other environmental parameters (e.g., temperature). Our results suggest that at least some scavenging deep sea amphipods may be able to escape relatively concentrated CO2 plumes (i.e., they do not become narcotized for several minutes) and that they may revive following 1 hour exposure to an oscillating CO2 plume (e.g., one meandering in a tidal current). In addition, our results suggest that scavenging amphipods and synaphobranchid eels may be able to detect and avoid intoxicating levels of CO2 resulting from deep ocean injection of CO2 and that specialized components of the deep sea fauna (e.g., some hydrothermal vent

  7. 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

  8. The G protein-coupled receptors in the pufferfish Takifugu rubripes

    PubMed Central

    2011-01-01

    Background Guanine protein-coupled receptors (GPCRs) constitute a eukaryotic transmembrane protein family and function as “molecular switches” in the second messenger cascades and are found in all organisms between yeast and humans. They form the single, biggest drug-target family due to their versatility of action and their role in several physiological functions, being active players in detecting the presence of light, a variety of smells and tastes, amino acids, nucleotides, lipids, chemicals etc. in the environment of the cell. Comparative genomic studies on model organisms provide information on target receptors in humans and their function. The Japanese teleost Fugu has been identified as one of the smallest vertebrate genomes and a compact model to study the human genome, owing to the great similarity in its gene repertoire with that of human and other vertebrates. Thus the characterization of the GPCRs of Fugu would provide insights to the evolution of the vertebrate genome. Results We classified the GPCRs in the Fugu genome and our analysis of its 316 membrane-bound receptors, available on the public databases as well as from literature, detected 298 GPCRs that were grouped into five main families according to the GRAFS classification system (namely, Glutamate, Rhodopsin, Adhesion, Frizzled and Secretin). We also identified 18 other GPCRs that could not be grouped under the GRAFS family and hence were classified as ‘Other 7TM’ receptors. On comparison of the GPCR information from the Fugu genome with those in the human and chicken genomes, we detected 96.83% (306/316) and 96.51% (305/316) orthology in GPCRs among the Fugu-human genomes and Fugu-chicken genomes, respectively. Conclusions This study reveals the position of pisces in vertebrate evolution from the GPCR perspective. Fugu can act as a reference model for the human genome for other protein families as well, going by the high orthology observed for GPCRs between Fugu and human. The

  9. 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

  10. 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.

  11. First Submersible Dives on Brothers Volcano, Kermadec Arc, Offshore New Zealand

    NASA Astrophysics Data System (ADS)

    de Ronde, C. E.; Massoth, G. J.; Ishibashi, J.; Embley, R. W.; Lupton, J. E.; Butterfield, D. A.; Yamanaka, T.; Evans, L. J.; Takai, K.

    2005-12-01

    Previous NZAPLUME and other cruises between 1999 and 2004 established that at least three major hydrothermal sites occur at Brothers; the NW caldera and cone sites are actively venting while the SE caldera site is extinct. In October 2004, the submersible Shinkai 6500 did 4 dives on Brothers as part of the SWEEP Vents expedition, the first dives anywhere along the 2,500 Kermadec-Tonga arc. Between April and May, 2005, an additional 5 dives were made at Brothers using the HURL submersible Pisces V as part of a New Zealand and NOAA co-sponsored expedition. In total, 6 dives have been done at the NW caldera site and 3 at the cone site. The NW caldera site is host to a significant sulfide deposit. It mainly crops out along a zone of discrete, narrow, fault bounded ledges between ~1600 and 1680 m, over strike lengths up to ~500 m. Locally, bands of active and extinct black smoker chimneys up to 7 m tall occur in this zone and strike orthogonal to the caldera walls, indicative of cross structures. Abundant sulfide talus and subcropping massive sulfides also occur at this site. The submersible dives recorded extensive alteration of the caldera walls and sampled individual chimneys, Fe-oxide crusts, and altered rocks. The cone site is hosted by ash and talus and is dominated near its summit by extensive deposition of elemental S and Fe-oxide crusts. No sulfides have been recovered from this site. Preliminary vent fluids results are from samples collected by the Shinkai 6500. They show two very different hydrothermal fluids. Those from the NW caldera site have temperatures up to 302°C, pH down to 2.8, low Mg and SO4 values, Cl between 510 and 760 mM, elevated Si and increasing Fe and Mn values with increasing Cl concentrations, consistent with a Cl-enriched endmember. By contrast, vent fluids from the cone site are gas-rich (up to 220 mM total gas), have temperatures <70°C, pH down to 1.9, Mg values near seawater concentrations and higher, Cl <550 mM and low levels of Si

  12. High-flux plasma exposure of ultra-fine grain tungsten

    SciTech Connect

    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-width 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

  13. 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

  14. Portrait of a Dark Horse: a Photometric and Spectroscopic Study of the Ultra-faint Milky Way Satellite Pegasus III

    NASA Astrophysics Data System (ADS)

    Kim, Dongwon; Jerjen, Helmut; Geha, Marla; Chiti, Anirudh; Milone, Antonino P.; Da Costa, Gary; Mackey, Dougal; Frebel, Anna; Conn, Blair

    2016-12-01

    Pegasus III (Peg III) is one of the few known ultra-faint stellar systems in the outer halo of the Milky Way. We present the results from a follow-up campaign with Magellan/IMACS and Keck/DEIMOS. Deep stellar photometry down to {r}0≈ 25 mag at 50% completeness level has allowed accurate measurements of its photometric and structural properties. The color-magnitude diagram of Peg III confirms that the stellar system is well described by an old (≳12 Gyr) and metal-poor ([Fe/H] ≲ -2.0 dex) stellar population at a heliocentric distance of 215 ± 12 kpc. The revised half-light radius {r}h=53+/- 14 pc, ellipticity ɛ ={0.38}-0.38+0.22, and total luminosity {M}V=-3.4+/- 0.4 are in good agreement with the values quoted in our previous paper. We further report on the spectroscopic identification of seven, possibly eight, member stars of Peg III. The Ca ii triplet lines of the brightest member stars indicate that Peg III contains stars with metallicity as low as [Fe/H] = -2.55 ± 0.15 dex. Peg III has a systemic velocity of -222.9 ± 2.6 km s-1 and a velocity dispersion of {5.4}-2.5+3.0 km s-1. The inferred dynamical mass within the half-light radius is {1.4}-1.1+3.0× {10}6{M}⊙ and the mass-to-light ratio M/{L}V={1470}-1240+5660 {M}⊙ /{L}⊙ , providing further evidence that Peg III is a dwarf galaxy satellite. We find that Peg III and another distant dwarf satellite Pisces II lie relatively close to each other ({{Δ }}{d}{spatial}=43+/- 19 kpc) and share similar radial velocities in the Galactic standard-of-rest frame ({{Δ }}{v}{GSR}=12.3+/- 3.7 km s-1). This suggests that they may share a common origin. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

  15. Delaunay Tessellation Field Estimator analysis of the PSCz local Universe: density field and cosmic flow

    NASA Astrophysics Data System (ADS)

    Romano-Díaz, Emilio; van de Weygaert, Rien

    2007-11-01

    We apply the Delaunay Tessellation Field Estimator (DTFE) to reconstruct and analyse the matter distribution and cosmic velocity flows in the local Universe on the basis of the PSCz galaxy survey. The prime objective of this study is the production of optimal resolution 3D maps of the volume-weighted velocity and density fields throughout the nearby universe, the basis for a detailed study of the structure and dynamics of the cosmic web at each level probed by underlying galaxy sample. Fully volume-covering 3D maps of the density and (volume-weighted) velocity fields in the cosmic vicinity, out to a distance of 150h-1Mpc, are presented. Based on the Voronoi and Delaunay tessellation defined by the spatial galaxy sample, DTFE involves the estimate of density values on the basis of the volume of the related Delaunay tetrahedra and the subsequent use of the Delaunay tessellation as natural multidimensional (linear) interpolation grid for the corresponding density and velocity fields throughout the sample volume. The linearized model of the spatial galaxy distribution and the corresponding peculiar velocities of the PSCz galaxy sample, produced by Branchini et al., forms the input sample for the DTFE study. The DTFE maps reproduce the high-density supercluster regions in optimal detail, both their internal structure as well as their elongated or flattened shape. The corresponding velocity flows trace the bulk and shear flows marking the region extending from the Pisces-Perseus supercluster, via the Local Superclusters, towards the Hydra-Centaurus and the Shapley concentration. The most outstanding and unique feature of the DTFE maps is the sharply defined radial outflow regions in and around underdense voids, marking the dynamical importance of voids in the local Universe. The maximum expansion rate of voids defines a sharp cut-off in the DTFE velocity divergence probability distribution function. We found that on the basis of this cut-off DTFE manages to consistently

  16. Boron isotopes in Fiji corals and precise ocean acidification reconstruction

    NASA Astrophysics Data System (ADS)

    Douville, E.; Juillet-Leclerc, A.; Cabioch, G.; Louvat, P.; Gaillardet, J.; Gehlen, M.; Bopp, L.; Paterne, M.

    2009-12-01

    Within the framework of EPOCA (European Project on OCean Acidification ) and the French INSU project PHARE, we are adapting the boron isotope technique to ancient corals with the scope to reconstruct “past” ocean pH changes. In this study, we applied the technique to surface seawater pH reconstructions based on tropical 20th century corals from Fiji. Models estimated a pH drop close to 0.07 pH units in the South Western Equatorial Pacific since the onset of the industrial era (Sabine et al., 2004). To reconstruct such a change in pH, the isotopic composition of boron (δ11B) in coral material has to be determined with a precision better than ±0.2‰. This analytical criteria was meet on a Multi-Collector ICPMS Neptune. We selected a Porites coral for the reconstruction of the time dependent evolution of pH. Our results show a progressive decrease of seawater pH between 1900 and 2000 of 0.08 +/- 0.02 pH units. This decrease in pH agrees with projections of surface ocean pH for the Fiji area obtained with the biogeochemical ocean circulation model NEMO-PISCES. Our results further reveal that seawater pH changes in the Fiji area are strongly affected by regional processes such as the South Pacific Convergence Zone (SPCZ) tightly linked the Pacific Decadal Oscillation (PDO). This last observation highlights the potential of the δ11B-pH technique for studying past changes of ocean dynamics. Hönisch, B., Hemming, N. G., Grottoli, A. G., Amat, A., Hanson, G. N. & Bijma, J. (2004). Assessing scleractinian corals as recoders for paleo-pH: Empirical calibration and vital effects. Geochimica et Cosmochimica Acta, 68(18), 3675-3685. Sabine, C. L., Feely, R. A., Gruber, N., Key, R. M., Lee, K., Bullister, J. L., Wanninkhof, R., Wong, C. S., Wallace, D. W. R., Tilbrook, B., Millero, F. J., Peng, T. H., Kozyr, A., Ono, T. & Rios, A. F. (2004). The Oceanic Sink for Anthropogenic CO2. Science, 305, 367-371.

  17. 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.

  18. 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<

  19. High-flux plasma exposure of ultra-fine grain tungsten

    DOE PAGES

    Kolasinski, R. D.; Buchenauer, D. A.; Doerner, R. P.; ...

    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

  20. 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