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Sample records for capillata medusae scyphozoa

  1. Induction of segmentation in polyps of Aurelia aurita (Scyphozoa, Cnidaria) into medusae and formation of mirror-image medusa anlagen.

    Science.gov (United States)

    Kroiher, M; Siefker, B; Berking, S

    2000-08-01

    Polyps of Aurelia aurita can transform into several medusae (jellyfish) in a process of sequential subdivision. During this transformation, two processes take place which are well known to play a key role in the formation of various higher metazoa: segmentation and metamorphosis. In order to compare these processes in bilaterians and cnidarians we studied the control and the kinetics of these processes in Aurelia aurita. Segmentation and metamorphosis visibly start at the polyp's head and proceed down the body column but do not reach the basal disc. The small piece of polyp which remains will develop into a new polyp. The commitment to the medusa stage moves down the body column and precedes the visible onset of segmentation by about one day. Segmentation and metamorphosis can start at the cut surface of transversely cut body columns, leading to a mirror-image pattern of sequentially developing medusae.

  2. Aurelia labiata medusae (Scyphozoa) in Roscoe Bay avoid tidal dispersion by vertical migration

    Science.gov (United States)

    Albert, David J.

    2007-05-01

    Aurelia labiata reside year around in Roscoe Bay on the west coast of Canada in spite of tides that exchange as much as 10% to 30% of the bay's water twice daily. Large numbers of medusae drift eastward over a gravel bar and out of the bay on ebb tides, only to return on flood tides. Drogues released into the tidal stream at the middle of an ebb tide drifted about 700 m out of the bay and into an adjacent large body of water. With the aid of a viewing box and lift net it was observed that after drifting out of the bay on an ebb tide, medusae remained within 300 m of the bay because they swam into still or counter current water below the turbulent ebb stream. When the tide turned to flood, medusae rose into the still water, became embedded in the nonturbulent flood stream, and drifted back into the bay. Vertical migration appears to enable the dense population of medusae to stay in a single location. This enhances reproductive success by keeping males and females in close proximity and increases survival by keeping the population in a favourable location.

  3. Sterile polystyrene culture dishes induce transformation of polyps into medusae in Aurelia aurita (Scyphozoa, Cnidaria).

    Science.gov (United States)

    Herrmann, Klaus; Siefker, Barbara; Berking, Stefan

    2003-01-01

    Polyps of Aurelia aurita produce medusae once a year. Under laboratory conditions this process, termed strobilation, can be induced by lowering the incubation temperature for about two weeks. Here we report a fast induction of strobilation by sterile polystyrene culture dishes. The effect is abolished when the culture dishes are washed twice with hot water prior to the experiment. We recommend that polystyrene cultureware should be pre-washed whenever there is an indication of unusual effects.

  4. Physiological and chemical analysis of neurotransmitter candidates at a fast excitatory synapse in the jellyfish Cyanea capillata (Cnidaria, Scyphozoa).

    Science.gov (United States)

    Anderson, Peter A V; Trapido-Rosenthal, H G

    2009-12-01

    Motor nerve net (MNN) neurons in the jellyfish Cyanea capillata communicate with one another by way of fast, bidirectional excitatory chemical synapses. As is the case with almost all identified chemical synapses in cnidarians, the identity of the neurotransmitter at these synapses is unclear. MNN neurons are large enough for stable intracellular recordings. This, together with the fact that they can be exposed, providing unlimited access to them and to their synapses, prompted a study of the action of a variety of neurotransmitter candidates, including those typically associated with fast synapses in higher animals. Only the amino acids taurine and beta-alanine produced physiological responses consistent with those of the normal EPSP in these cells. Moreover, chemical analysis revealed that both taurine and beta-alanine are present in the neurons and released by depolarization. These various findings strongly suggest that either or both of these amino acids, or a closely related compound is the neurotransmitter at the fast chemical synapses between MNN neurons.

  5. A novel proteinaceous cytotoxin from the northern Scyphozoa Cyanea capillata (L.) with structural homology to cubozoan haemolysins.

    Science.gov (United States)

    Lassen, Stephan; Helmholz, Heike; Ruhnau, Christiane; Prange, Andreas

    2011-04-01

    It is well known that jellyfish are producers of complex mixtures of proteinaceous toxins for prey capture and defence. Nevertheless, studies on boreal scyphozoans concerning venom composition and toxic effects are rare. Here the isolation of a novel cytotoxic protein from the fishing tentacle venom of Cyanea capillata (L. 1758) using bioactivity-guided, multidimensional liquid chromatography is described. The crude venom was purified utilising preparative size-exclusion, ion-exchange, and reversed-phase chromatography. The cytotoxicity of resulting chromatographic fractions has been proven by a dye-uptake assay with the human hepatocyte cell line HepG2. The final purification step yielded, among other fractions, a fraction containing a single protein (named CcTX-1) with a molecular weight of its main isoform of 31.17 kDa The purification process leads to an increased cytotoxic activity per protein equivalents and the finally isolated CcTX-1 caused a nearly total loss of cell viability at a protein concentration of 1.3 μg mL⁻¹ corresponding to 0.4 μg/10⁵ cells. De novo sequencing of CcTX-1 was conducted after enzymatic digestion and subsequent matrix-assisted laser desorption ionisation time-of-flight/time-of-flight mass spectrometry (MALDI-ToF/ToF MS/MS). The obtained sequence data provide an approximate 85% description of the amino acid sequence. This sequence information partially matched that of two known haemolytic proteins of two cubozoan species: CaTX-1 from Carybdea alata Reynaud, 1830 and CrTX-1 from Carybdea rastonii Haacke, 1886.

  6. Reappearance and seasonality of Phyllorhiza punctata von Lendenfeld (Cnidaria, Scyphozoa, Rhizostomeae medusae in southern Brazil Reaparecimento e sazonalidade da medusa Phyllorhiza punctata von Lendenfeld (Cnidaria, Scyphozoa, Rhizostomeae no sul do Brasil

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    Maria A. Haddad

    2006-09-01

    Full Text Available The scyphozoan Phyllorhiza punctata von Lendenfeld, 1884 (Mastigiidae, known only from Indo-Pacific waters prior to the 1950s, is today found far from its original distribution, probably due to human activities. First seen in 1955 in Brazilian waters, medusae were found in southern and southeastern coasts, disappearing (at least as a medusa in the early 1960's. Another population was found in the late 1990's, in the state of Bahia, and again in late 2001, many sightings were reported along the coasts of Paraná and Santa Catarina (25º20'S, 48º12'W to 27º26'S, 48º22'W. A large summer bloom, followed by decline and disappearance in winter and spring, occurs every year since then. The reasons for this recent mass occurrence are unknown. Despite few scattered records of the species in Brazil, it is probably widespread, occurring from the coast of Ceará (3º43'S, 38º28'W, in the northeast, to Santa Catarina, in the south.A cifomedusa Phyllorhiza punctata von Lendenfeld, 1884 (Mastigiidae, conhecida somente de águas do Indo-Pacífico até a década de 1950, é encontrada atualmente em diversos locais longe de sua distribuição original, provavelmente devido a atividades humanas. No Brasil, foi encontrada primeiramente em 1955 nas costas sul e sudeste, de onde desapareceu, ao menos no estágio de medusa, no início dos anos 1960. Uma outra população de medusas apareceu na década de 1990 no litoral do Estado da Bahia e, desde o final de 2001, reapareceram no litoral dos Estados do Paraná e Santa Catarina (25º20'S, 48º12'W a 27º26'S, 48º22'W, onde têm ocorrido em grande abundância durante os meses de verão. Durante o outono, segue um declínio da população, até seu desaparecimento no inverno. As razões desse recente aparecimento da espécie no Brasil são desconhecidas, entretanto, apesar dos poucos e esparsos registros, sua distribuição provavelmente ampliou-se por toda a costa, ocorrendo desde o Ceará (3 º43'S, 38º28'W, na

  7. A newly discovered oxidant defence system and its involvement in the development of Aurelia aurita (Scyphozoa, Cnidaria): reactive oxygen species and elemental iodine control medusa formation.

    Science.gov (United States)

    Berking, Stefan; Czech, Nicole; Gerharz, Melanie; Herrmann, Klaus; Hoffmann, Uwe; Raifer, Hartmann; Sekul, Guy; Siefker, Barbara; Sommerei, Andrea; Vedder, Fritz

    2005-01-01

    In Aurelia aurita, applied iodine induces medusa formation (strobilation). This process also occurs when the temperature is lowered. This was found to increase oxidative stress resulting in an increased production of iodine from iodide. One polyp produces several medusae (initially termed ephyrae) starting at the polyp's oral end. The spreading of strobilation down the body column is controlled by a feedback loop: ephyra anlagen decrease the tyrosine content in adjacent polyp tissue by producing melanin from tyrosine. Endogenous tyrosine is able to remove iodine by forming iodiferous tyrosine compounds. The reduced level of tyrosine causes the ephyra-polyp-border to move towards the basal end of the former polyp. We argue that an oxidant defence system may exist which makes use of iodide and tyrosine. Like other marine invertebrates, polyps of Aurelia contain iodide ions. Inevitably produced peroxides oxidise iodide into iodine. The danger to be harmed by iodine is strongly decreased by endogenous tyrosine which reacts with iodine to form iodiferous tyrosine compounds including thyroxin. Both substances together, iodide and tyrosine, form an efficient oxidant defence system which shields the tissue against damage by reactive oxygen species. In the course of evolution (from a species at the basis of the animal kingdom like Aurelia to a highly evolved species like man) the waste product thyroxin (indicating a high metabolic rate) has developed into a hormone which controls the metabolic rate.

  8. Offshore dispersion of ephyrae and medusae of Aurelia aurita s.l. (Cnidaria: Scyphozoa) from port enclosures: Physical and biological factors

    Science.gov (United States)

    Makabe, Ryosuke; Takeoka, Hidetaka; Uye, Shin-ichi

    2015-12-01

    Recurrent outbreaks of the common jellyfish Aurelia aurita s.l. have been increasingly significant, particularly in human perturbed coastal waters, where numerous artificial constructions increase suitable habitat for polyp populations. We examined the spatiotemporal dispersion process in 6 ports of ephyrae of A. aurita after release from strobilating polyps, to offshore waters of northern Harima Nada (eutrophic eastern Inland Sea of Japan) from January to May 2010. Almost exclusive occurrence of the ephyra stage in the ports demonstrated that their seeding polyps reside in the port enclosures, and liberated ephyrae are rapidly exported offshore by tidal water exchange. Post-ephyra stages occurred primarily outside the ports, and their age increased gradually offshore, ca. up to 9 km off the ports, and the pattern of age increase could be simulated by a simple diffusion model. However, there was an abrupt decline in A. aurita density beyond ca. 3 km off the shore, where jellyfish-eating Chrysaora pacifica medusae were prevalent. We conclude that physical forces are primarily responsible for offshore dispersion of A. aurita, and a biological factor, i.e. predation by C. pacifica, jointly affects the distribution pattern of A. aurita.

  9. Primer registro de la asociación del jurelillo negro Hemicaranx zelotes Gilbert (Pisces: Carangidae con la medusa bala de cañón Stomolophus meleagris Agassiz (Scyphozoa: Rhizostomatidae en Bahía de Kino, Golfo de California First record of association of the Blackfin Jack Hemicaranx zelotes Gilbert (Pisces: Carangidae with the cannonball jellyfish Stomolophus meleagris Agassiz (Scyphozoa: Rhizostomatidae in Kino Bay, Gulf of California

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    Juana López Martínez

    2008-08-01

    Full Text Available Se detectó la asociación de juveniles del jurelillo negro Hemicaranx zelotes (Gilbert 1898 con medusas de la especie Stomolophus meleagris (Agassiz 1860 en Bahía de Kino, Golfo de California, México. Los peces fueron observados acompañando a la medusa entre la subumbrela y los brazos orales, manifestándose una simbiosis, comportamiento usualmente utilizado por los peces juveniles para protegerse de sus depredadores e incrementar su tasa de sobrevivencia. Hasta la fecha no se había documentado ningún caso de asociación entre el jurelillo negro y la medusa bala de cañón, por lo que este es el primer registro de tal simbiosis.Juvenile Blacking Jack Hemicaranx zelotes (Gilbert 1898 associated with cannonball jellies Stomolophus meleagris (Agassiz 1860 in Kino Bay, Gulf of California, Mexico was observed. The fish accompany the jellies, swim between the umbrella and the oral arms, showing a symbiotic behavior that the fish use for protection from predators. This is the first record of a symbiotic association of Blacking Jack with can-nonball jellies.

  10. Development of the rhopalial nervous system in Aurelia sp.1 (Cnidaria, Scyphozoa).

    Science.gov (United States)

    Nakanishi, Nagayasu; Hartenstein, Volker; Jacobs, David K

    2009-06-01

    We examined the development of the nervous system in the rhopalium, a medusa-specific sensory structure, in Aurelia sp.1 (Cnidaria, Scyphozoa) using confocal microscopy. The rhopalial nervous system appears primarily ectodermal and contains neurons immunoreactive to antibodies against tyrosinated tubulin, taurine, GLWamide, and FMRFamide. The rhopalial nervous system develops in an ordered manner: the presumptive gravity-sensing organ, consisting of the lithocyst and the touch plate, differentiates first; the "marginal center," which controls swimming activity, second; and finally, the ocelli, the presumptive photoreceptors. At least seven bilaterally arranged neuronal clusters consisting of sensory and ganglion cells and their neuronal processes became evident in the rhopalium during metamorphosis to the medusa stage. Our analysis provides an anatomical framework for future gene expression and experimental studies of development and functions of scyphozoan rhopalia.

  11. Distribuição e validade taxonômica do gênero Chrysaora (Cnidaria; Scyphozoa) na América do Sul

    OpenAIRE

    Rosa, Fernanda Creres [UNESP

    2016-01-01

    Chrysaora é um dos gêneros mais ricos de espécies dentro da subclasse Discomedusae Haeckel, 1880. Na América do Sul existem duas espécies do gênero Chrysaora, Chrysaora lactea (Eschscholtz, 1829) e Chrysaora plocamia (Lesson 1830). A cifomedusa C. lactea é uma das mais comuns e amplamente distribuídas medusas de Scyphozoa na costa. A distribuição dessa espécie é contínua desde o Golfo do México até a costa norte da Argentina (Morandini e Marques 2010). Já a espécie C. plocamia apresenta...

  12. CT Demonstration of Caput Medusae

    Science.gov (United States)

    Weber, Edward C.; Vilensky, Joel A.

    2009-01-01

    Maximum intensity and volume rendered CT displays of caput medusae are provided to demonstrate both the anatomy and physiology of this portosystemic shunt associated with portal hypertension. (Contains 2 figures.)

  13. : Writing as medusa

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    Telma Scherer

    2016-12-01

    Full Text Available http://dx.doi.org/10.5007/2175-7917.2016v21n2p118 In this paper I’ll offer a personal reading of the short novel Água viva (medusa, or “living water”, in Portuguese from Clarice Lispector, through Helène Cixous statements about the creative process which she explains in her book Three steps in the ladder or writing. Cixous creates the image of a descendent ladder that has three steps: death, dreams and roots. Lispector does the same movement searching her “it”, and composes a radical practice with language that is also an investigation. In order to follow this path of the descendent ladder and analyze the “it” through comparative reading, I’ll bring some of Hilda Hilst’s poems, from her book Poemas malditos, gozozos e devotos and also Sylvia Plath’s, from Ariel, namely “Lady Lazarus”. Hilst constructs a game between obedience and subversion, faith and poetic creation, proposing a complexity of images from the idea of God, transfigured. Plath already brings to the reflection the cyclic recurrence, which is also a kind of all fear letting go. The readings of Hilst and Plath give light, in its own way, to the route undertaken in Cixous trail and enrich the search of the Lispector`s "it".

  14. Caput medusae in alcoholic liver disease

    African Journals Online (AJOL)

    include spider angiomas, palmar erythema, icterus, pruritus, gynecomastia, etc. ... The caput medusae was left alone as no specific treatment was deemed ... veins into the abdominal wall veins, which manifest as the caput medusae.[2] The ...

  15. Seasonal and vertical distribution of medusae in Aysén region, southern Chile Distribución estacional y vertical de medusas en la región de Aysén, sur de Chile

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    Viviana Bravo

    2011-07-01

    Full Text Available Medusae collected in winter and spring 2007 were analyzed in a longitudinal transect made between the Boca de Guafo and Elefantes Fjord, southern Chile. A total of 30 species were identified, Hydromedusae (29 and Scyphozoa (1, where Bougainvillia macloviana, Hybocodon chilensis, Hydractinia tenuis, Laodicea pulcra, L. undulada, Modeeria rotunda and Chrysaora plocamia represent new records for the area. A significant increase in the jellyfish abundance was higher in spring than in winter (fourteen times higher, with 68% of common species in both seasons. The specific diversity was slightly higher in winter (3.4 bits than spring (3.2 bits, the species richness instead was higher in spring than in winter, with a mean of 5 and 12 species, respectively. The vertical distribution showed the presence of surface (H. borealis, deep (A. apicata, C. peregrina and R. velatum and wide bathymetric distribution (B. muscoides and B. muscus species. Results from the area were compared with previous results (2002-2003 thus proving that most species identified are common in southern Chilean fjords and channels.Se analizaron las medusas colectadas en invierno y primavera de 2007, en una transecta longitudinal efectuada entre la boca del Guafo y fiordo Elefantes, sur de Chile. Se identificó un total de 30 especies, Hydromedusae (29 y Scyphozoa (1, de las cuales Bougainvillia macloviana, Hybocodon chilensis, Hydractinia tenuis, Laodicea pulcra, L. undulada, Modeeria rotunda y Chrysaora plocamia constituyen nuevos registros para esta área. Se determinó un fuerte incremento en la abundancia de medusas en primavera respecto a invierno y (14 veces mayor, con un 68% de especies comunes en ambas estaciones. La diversidad específica fue levemente mayor en invierno (3.4 bits que primavera (3.2 bits, en cambio la riqueza de especies fue mayor en primavera que en invierno, con una media de 5 y 12 especies, respectivamente. La distribución vertical mostró en ambas

  16. Enkele waarnemingen betreffende de ongeslachtelijke voortplanting van de Scyphozoa:

    NARCIS (Netherlands)

    van Erp, J.

    1958-01-01

    Polyp stages were reared from planulae by keeping adult jellyfish in aquaria. Polyps of the species Aurelia aurita, Cyanea capillata and Chrysaora hysoscella, were kept at different temperatures. Scyphistomae of Aurelia reproduce mainly by stolonization. An influence of temperat

  17. Enkele waarnemingen betreffende de ongeslachtelijke voortplanting van de Scyphozoa:

    NARCIS (Netherlands)

    van Erp, J.

    1958-01-01

    Polyp stages were reared from planulae by keeping adult jellyfish in aquaria. Polyps of the species Aurelia aurita, Cyanea capillata and Chrysaora hysoscella, were kept at different temperatures. Scyphistomae of Aurelia reproduce mainly by stolonization. An influence of

  18. Life Cycle Reversal in Aurelia sp.1 (Cnidaria, Scyphozoa).

    Science.gov (United States)

    He, Jinru; Zheng, Lianming; Zhang, Wenjing; Lin, Yuanshao

    2015-01-01

    The genus Aurelia is one of the major contributors to jellyfish blooms in coastal waters, possibly due in part to hydroclimatic and anthropogenic causes, as well as their highly adaptive reproductive traits. Despite the wide plasticity of cnidarian life cycles, especially those recognized in certain Hydroza species, the known modifications of Aurelia life history were mostly restricted to its polyp stage. In this study, we document the formation of polyps directly from the ectoderm of degenerating juvenile medusae, cell masses from medusa tissue fragments, and subumbrella of living medusae. This is the first evidence for back-transformation of sexually mature medusae into polyps in Aurelia sp.1. The resulting reconstruction of the schematic life cycle of Aurelia reveals the underestimated potential of life cycle reversal in scyphozoan medusae, with possible implications for biological and ecological studies.

  19. Life Cycle Reversal in Aurelia sp.1 (Cnidaria, Scyphozoa.

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    Jinru He

    Full Text Available The genus Aurelia is one of the major contributors to jellyfish blooms in coastal waters, possibly due in part to hydroclimatic and anthropogenic causes, as well as their highly adaptive reproductive traits. Despite the wide plasticity of cnidarian life cycles, especially those recognized in certain Hydroza species, the known modifications of Aurelia life history were mostly restricted to its polyp stage. In this study, we document the formation of polyps directly from the ectoderm of degenerating juvenile medusae, cell masses from medusa tissue fragments, and subumbrella of living medusae. This is the first evidence for back-transformation of sexually mature medusae into polyps in Aurelia sp.1. The resulting reconstruction of the schematic life cycle of Aurelia reveals the underestimated potential of life cycle reversal in scyphozoan medusae, with possible implications for biological and ecological studies.

  20. Dynamic Model for Life History of Scyphozoa.

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    Congbo Xie

    Full Text Available A two-state life history model governed by ODEs is formulated to elucidate the population dynamics of jellyfish and to illuminate the triggering mechanism of its blooms. The polyp-medusa model admits trichotomous global dynamic scenarios: extinction, polyps survival only, and both survival. The population dynamics sensitively depend on several biotic and abiotic limiting factors such as substrate, temperature, and predation. The combination of temperature increase, substrate expansion, and predator diminishment acts synergistically to create a habitat that is more favorable for jellyfishes. Reducing artificial marine constructions, aiding predator populations, and directly controlling the jellyfish population would help to manage the jellyfish blooms. The theoretical analyses and numerical experiments yield several insights into the nature underlying the model and shed some new light on the general control strategy for jellyfish.

  1. The Occurrence of Ophiocnemis marmorata (Echinodermata:Ophiuroidea) Associated with the Rhizostome Medusa Rhopilema hispidum (Cnidaria: Scyphozoa)

    Institute of Scientific and Technical Information of China (English)

    Govindan Kanagaraj; Pithchai Sampath Kumar; Andr(e) C. Morandini

    2008-01-01

    The association of scyphomedusae with invertebrates has been long known in the literature; especially with hyperiidsamphipods.The association of echinoderms with jellyfish is not common and rarely recorded.We reported the association of theophiuroid Ophiocnemis marmorata with the rhizostome scyphomedusa Rhopilema hispidum collected in Vellar estuary (on thesoutheast coast of India).O.marmorata is supposed to be a filter feeding ophiuroid,quite common in soft bottom of shallow waters.The brittle stars possibly seek for food supply,shelter and protection through the association.

  2. The Spherical Tokamak MEDUSA for Mexico

    Science.gov (United States)

    Ribeiro, C.; Salvador, M.; Gonzalez, J.; Munoz, O.; Tapia, A.; Arredondo, V.; Chavez, R.; Nieto, A.; Gonzalez, J.; Garza, A.; Estrada, I.; Jasso, E.; Acosta, C.; Briones, C.; Cavazos, G.; Martinez, J.; Morones, J.; Almaguer, J.; Fonck, R.

    2011-10-01

    The former spherical tokamak MEDUSA (Madison EDUcation Small Aspect.ratio tokamak, R Mexican Fusion Network. Strong liaison within national and international plasma physics communities is expected. New activities on plasma & engineering modeling are expected to be developed in parallel by using the existing facilities such as a multi-platform computer (Silicon Graphics Altix XE250, 128G RAM, 3.7TB HD, 2.7GHz, quad-core processor), ancillary graph system (NVIDIA Quadro FE 2000/1GB GDDR-5 PCI X16 128, 3.2GHz), and COMSOL Multiphysics-Solid Works programs.

  3. The Medusa Algorithm for Polynomial Matings

    DEFF Research Database (Denmark)

    Boyd, Suzanne Hruska; Henriksen, Christian

    2012-01-01

    The Medusa algorithm takes as input two postcritically finite quadratic polynomials and outputs the quadratic rational map which is the mating of the two polynomials (if it exists). Specifically, the output is a sequence of approximations for the parameters of the rational map, as well as an image...... of its Julia set. Whether these approximations converge is answered using Thurston's topological characterization of rational maps. This algorithm was designed by John Hamal Hubbard, and implemented in 1998 by Christian Henriksen and REU students David Farris and Kuon Ju Liu. In this paper we describe...... the algorithm and its implementation, discuss some output from the program (including many pictures) and related questions. Specifically, we include images and a discussion for some shared matings, Lattès examples, and tuning sequences of matings....

  4. A study of medusae from Andaman and Nicobar waters

    Digital Repository Service at National Institute of Oceanography (India)

    Santhakumari, V.

    The results obtained from 14 cruises undertaken by FORV Sagar Sampada during the period 1986-1990 from Andaman and Nicobar waters are detailed. 346 zooplankton collections were made during this period and medusae were found from 307 stations. A...

  5. Systematics and biogeography of the jellyfish Aurelia labiata (Cnidaria: Scyphozoa).

    Science.gov (United States)

    Gershwin, L A

    2001-08-01

    The hypothesis that the common eastern North Pacific Aurelia is A. aurita is falsified with morphological analysis. The name Aurelia labiata is resurrected, and the species is redescribed, to refer to medusae differing from A. aurita by a suite of characters related to a broad and elongated manubrium. Specifically, the oral arms are short, separated by and arising from the base of the fleshy manubrium, and the planulae are brooded upon the manubrium itself, rather than on the oral arms. Aurelia aurita possesses no corresponding enlarged structure. Furthermore, the number of radial canals is typically much greater in A. labiata, and thus the canals often appear more anastomosed than in A. aurita. Finally, most A. labiata medusae possess a 16-scalloped bell margin, whereas the margin is 8-scalloped in most A. aurita. Separation of the two forms has previously been noted on the basis of allozyme and isozyme analyses and on the histology of the neuromuscular system. Partial 18S rDNA sequencing corroborates these findings. Three distinct morphotypes of A. labiata, corresponding to separate marine bioprovinces, have been identified among 17 populations from San Diego, California, to Prince William Sound, Alaska. The long-undisputed species A. limbata may be simply a color morph of A. labiata, or a species within a yet-unelaborated A. labiata species complex. The first known introduction of Aurelia cf. aurita into southern California waters is documented. Although traditional jellyfish taxonomy tends to recognize many species as cosmopolitan or nearly so, these results indicate that coastal species, such as A. labiata, may experience rapid divergence among isolated populations, and that the taxonomy of such species should therefore be scrutinized with special care.

  6. Ulcerative umbrellar lesions in captive moon jelly (Aurelia aurita) medusae.

    Science.gov (United States)

    LaDouceur, E E B; Garner, M M; Wynne, J; Fish, S; Adams, L

    2013-05-01

    Over a period of 6 months, dozens of moon jelly (Aurelia aurita) medusae from a single-species exhibit at the California Science Center (CSC) developed exumbrellar ulcers. Ulcers were progressive, causing umbrellar creases that expanded radially to the bell rim and occasional adoral erosions that extended into gastrovascular cavities. Husbandry interventions, including addition of ultraviolet light sterilizers, repopulation with fresh cultures, and enclosure disinfection, did not arrest the recurrence of lesions. Biopsies or whole specimens representing 17 medusae (15 affected and 2 grossly unaffected) from CSC and 2 control medusae from Aquarium of the Pacific were submitted to a private diagnostic laboratory and processed for light and electron microscopy. Microscopic lesions were present in all CSC medusae and were not observed or negligible in control medusae. Lesions included ulceration, necrosis, and hyperplasia in all umbrellar layers, with most severe lesions in the exumbrella and amoebocyte infiltration in the underlying mesoglea. Special stains, electron microscopy, and fungal culture did not associate microorganisms with the lesions. Bacterial cultures from the CSC population consistently grew Shewanella and Vibrio spp, both of which were considered commensal. Trauma and environmental stress are proposed as possible causes for the ulcers.

  7. Relações de tamanho e peso das grandes medusas (Cnidaria do litoral do Paraná, Sul do Brasil Size-weight relationship among macromedusae (Cnidaria of Paraná coast Southern Brazil

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    Miodeli Nogueira Jr

    2006-12-01

    Full Text Available Relações de tamanho e peso são dados básicos importantes para facilitar estimativas de estoques, de monitoramentos contínuos e de larga escala das espécies, além de permitir a obtenção de valores de biomassa a partir da distribuição de tamanho. Apesar destes dados serem básicos e de reconhecida importância ecológica e sócio-econômica, estudos biométricos das grandes medusas do litoral brasileiro ainda inexistem. Apresenta-se, neste estudo, as relações de tamanho e peso das seis espécies de macromedusas mais comuns no litoral paranaense: Tamoya haplonema Müller, 1859 e Chiropsalmus quadrumanus (Müller, 1859 - Cubozoa; Olindias sambaquiensis Müller, 1861 - Hydrozoa; Chrysaora lactea Eschscholtz, 1829, Lychnorhiza lucerna Haeckel, 1880 e Phyllorhiza punctata von Lendenfeld, 1884 - Scyphozoa. Foram utilizadas equações do tipo Y = aXb onde, Y = peso úmido; X = diâmetro da umbrela (com exceção de T. haplonema, para a qual utilizou-se a medida de altura umbrelar; a e b são os parâmetros estimados para cada população. A maioria das espécies estudadas apresentou alometria negativa, uma vez que b era menor que 3 na maioria dos casos, variando entre 2,415 e 3,028.Size-weight relationships are important for population stock estimates, continuous and large-scale population monitoring, as well as permitting the estimation of population biomass from size-class distribution. While these data are basic and useful for ecological and economical analyses, such estimates for Brazilian jellyfish do not exist. Here we present size-weight relationships for the six most common species of large medusae in the coast of Paraná, southern Brazil: Tamoya haplonema Müller, 1859 and Chiropsalmus quadrumanus (Müller, 1859 - Cubozoa; Olindias sambaquiensis Müller, 1861 - Hydrozoa; Chrysaora lactea Eschscholtz, 1829, Lychnorhiza lucerna Haeckel, 1880 and Phyllorhiza punctata von Lendenfeld, 1884 - Scyphozoa. A regression of the form Y = a

  8. Cubozoa e Scyphozoa (Cnidaria: Medusozoa de águas costeiras do Brasil Cubozoa and Scyphozoa (Cnidaria: Medusozoa from Brazilian coastal waters

    Directory of Open Access Journals (Sweden)

    André C. Morandini

    2005-09-01

    Full Text Available As espécies de Cubozoa e Scyphozoa costeiras que ocorrem no Brasil são descritas, com base em espécimes de coleções de museus e exemplares recém-coletados. Chaves de identificação e um glossário também são apresentados. As espécies descritas são: Aurelia sp.; Cassiopea xamachana Bigelow, 1892; Chiropsalmus quadrumanus (Müller, 1859; Chrysaora lactea Eschscholtz, 1829; Drymonema dalmatinum Haeckel, 1880; Linuche unguiculata (Swartz, 1788; Lychnorhiza lucerna Haeckel, 1880; Nausithoe aurea Silveira & Morandini, 1997; Phyllorhiza punctata von Lendenfeld, 1884; Stomolophus meleagris Agassiz, 1862; Tamoya haplonema Müller, 1859 e Tripedalia cystophora Conant, 1897.Coastal species of Cubozoa and Scyphozoa occurring in Brazil are described, based on museum specimens and recently collected ones. Identification keys and a glossary are also presented. The listed species are: Aurelia sp.; Cassiopea xamachana Bigelow, 1892; Chiropsalmus quadrumanus (Müller, 1859; Chrysaora lactea Eschscholtz, 1829; Drymonema dalmatinum Haeckel, 1880; Linuche unguiculata (Swartz, 1788; Lychnorhiza lucerna Haeckel, 1880; Nausithoe aurea Silveira & Morandini, 1997; Phyllorhiza punctata von Lendenfeld, 1884; Stomolophus meleagris Agassiz, 1862; Tamoya haplonema Müller, 1859; and Tripedalia cystophora Conant, 1897.

  9. Influence of the thermocline on the vertical migration of medusae ...

    African Journals Online (AJOL)

    1991-01-22

    Jan 22, 1991 ... on the second than on the first day of sampling, chiefly in the 20-0 stratum. Differences in ... Certain researchers consider the search for prey to be the ... of medusae during a 48 h sampling period in various depth strata in the ...

  10. Dosimetry experiments at the MEDUSA Facility (Little Mountain).

    Energy Technology Data Exchange (ETDEWEB)

    Harper-Slaboszewicz, Victor Jozef; Shaneyfelt, Marty Ray; Sheridan, Timothy J.; Hartman, E. Frederick; Schwank, James Ralph

    2010-10-01

    A series of experiments on the MEDUSA linear accelerator radiation test facility were performed to evaluate the difference in dose measured using different methods. Significant differences in dosimeter-measured radiation dose were observed for the different dosimeter types for the same radiation environments, and the results are compared and discussed in this report.

  11. MEDUSA (Martian Environmental DUst Systematic Analyser)

    Science.gov (United States)

    Battaglia, R.; Colangeli, L.; della Corte, V.; Esposito, F.; Ferrini, G.; Mazzotta Epifani, E.; Palomba, E.; Palumbo, P.; Panizza, A.; Rotundi, A.

    2003-04-01

    ) onboard the Mars Global Surveyor. Seasonal variations in the column abundance are due to the combined effect of exchange of H_2O between atmosphere and water reservoirs (i.e. polar caps, regolith) and atmospheric transport. Despite the low absolute water content (0.03% by volume), relative humidity can exceed 100% leading to frosting phenomena, thanks to low Martian temperatures. The typical value of the pressure at surface, close to the triple point value of water phase diagram, makes the persistence of liquid water at the surface of Mars highly improbable. This means that the water is probably present exclusively in gaseous and solid states, at the surface level. Attempts to use space-born and earth-based observations to estimate quantitatively surface and near-surface sources and sinks of water vapour have had good but also partial success. Most important questions that appear from the present knowledge is how the water vapour atmospheric circulation occurs and how to explain the difference in the hemispheric and seasonal behaviour of the water vapour. Despite TES results showed that a percentage of hemispheric "asymmetry" of the seasonal vapour abundance was probably due to the presence of two dust storms during MAWD observations, an evident difference remains partially unexplained. In this context, it is extremely important to study the role of the different contributions to the production of atmospheric vapour from the main reservoirs and to the formation of water ice clouds most probably catalysed by the atmospheric dust. At present, no in situ measurement of water vapour content was performed yet. We discuss the possibility of using a new concept instrument for extraterrestrial planetary environments, based on the past experience acquired for dust monitoring in space and on Earth and new possible technologies for space applications. MEDUSA (Martian Environmental Dust Analyser) project is a multisensor and multistage instrument based on an optical detector of dust

  12. Variación estacional de grandes medusas (Scyphozoa en un sistema de lagunas costeras del sur del Golfo de México (1977/1978

    Directory of Open Access Journals (Sweden)

    Samuel Gomez-Aguirre

    1980-12-01

    Full Text Available Two species of large jelly-fish Aurelia aurita L. and Stomoiophus meleagris Ag, have been registered within a yearly cycle at the system of coastal lagoons "Carmen-Machoria-Redonda ", South of the Gulf of Mexico. A. aurita showed two well defined periods: autumn/winter with predominant young specimens (25 to 100 mm and spring/summer with a wide adult distribution (200 to 400 mm, beeing the juveniles restricted to the internal, regions of the system. S. meleagris gave evidence of adult populations all year round, the greatest population density occurred during the summer/autumn period with maximum sizes of 200 to 300 mm and during the winter/spring period, juveniles from 10 to 30 mm in December and 50 to 100 mm in April, giving a distribution pattern very similar to A. aurita.

  13. [Shape conservatism and shaping variability. The comparative analysis of Hydrozoa and Scyphozoa early development].

    Science.gov (United States)

    Kraus, Iu A

    2002-01-01

    The morphogenetic pathways based on the self-organization take an important part in the early development of White Sea Cnidarians--Dynamena pumila (Hydrozoa) and Aurelia aurita (Scyphozoa). Comparative analysis of their early development revealed two patterns of embryonic spatial structure reproduced in the morphogenesis of both species in spite of the differences of morphogenetic paths. These are toroidal and bilaterally symmetrical shapes. It is possible that these shapes correspond to the equilibrium states of developing system and their stable reproduction is a result of epigenetic rather than genetic program.

  14. Approaches to the ethology of hydroids and medusae (Cnidaria, Hydrozoa

    Directory of Open Access Journals (Sweden)

    M. P. Miglietta

    2000-12-01

    Full Text Available The behavioural patterns of 26 species of Antho- and Leptomedusae (with or without medusa stage were investigated by video recordings. The analysed activities were: answers to mechanical stimuli, prey capture and ingestion, digestion, egestion, and swimming. The quantity of behavioural patterns identified in the small number of hydrozoan diversity studied so far is sufficient to demonstrate that these supposedly simple animals have evolved a complex array of responses to both external and internal stimuli.

  15. A specific antimicrobial protein CAP-1 from Pseudomonas sp. isolated from the jellyfish Cyanea capillata.

    Science.gov (United States)

    Yin, Manman; Liu, Dan; Xu, Feng; Xiao, Liang; Wang, Qianqian; Wang, Beilei; Chang, Yinlong; Zheng, Jiemin; Tao, Xia; Liu, Guoyan; Zhang, Liming

    2016-01-01

    A bacterium strain, designated as CMF-2, was isolated from the jellyfish Cyanea capillata and its culture supernatant exhibited a significant antimicrobial activity. The strain CMF-2 was identified as Pseudomonas sp. based on the morphological, biochemical and physiological characteristics as well as 16S rRNA sequence analysis. In this study, an antimicrobial protein, named as CAP-1, was isolated from the culture of CMF-2 through ammonium sulfate precipitation and gel filtration chromatography. According to the result of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), a major band indicated that the antimicrobial protein had a molecular mass of about 15 kDa, and it was identified as a hypothetical protein by MALDI-TOF-MS analysis and Mascot searching. CAP-1 displayed a broad antimicrobial spectrum against the indicator bacteria and fungus, including Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Candida albicans, especially some marine-derived microorganisms such as Vibrio vulnificus, Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio cholera, and Vibrio anguillarum, but showed little impact on tumor cells and normal human cells. The protein CAP-1 remained a stable antimicrobial activity in a wide range of temperature (20-80°C) and pH (2-10) conditions. These results suggested that CAP-1 might have a specific antimicrobial function not due to cytotoxicity.

  16. Evaluation of Cyanea capillata Sting Management Protocols Using Ex Vivo and In Vitro Envenomation Models

    Directory of Open Access Journals (Sweden)

    Thomas K. Doyle

    2017-07-01

    Full Text Available Lion’s mane jellyfish (Cyanea capillata stings cause severe pain and can lead to dangerous systemic effects, including Irukandji-like syndrome. As is the case for most cnidarian stings, recommended medical protocols in response to such stings lack rigorous scientific support. In this study, we sought to evaluate potential first aid care protocols using previously described envenomation models that allow for direct measurements of venom activity. We found that seawater rinsing, the most commonly recommended method of tentacle removal for this species, induced significant increases in venom delivery, while rinsing with vinegar or Sting No More® Spray did not. Post-sting temperature treatments affected sting severity, with 40 min of hot-pack treatment reducing lysis of sheep’s blood (in agar plates, a direct representation of venom load, by over 90%. Ice pack treatment had no effect on sting severity. These results indicate that sting management protocols for Cyanea need to be revised immediately to discontinue rinsing with seawater and include the use of heat treatment.

  17. The Acute Toxicity and Hematological Characterization of the Effects of Tentacle-Only Extract from the Jellyfish Cyanea capillata

    Directory of Open Access Journals (Sweden)

    Liming Zhang

    2011-03-01

    Full Text Available To investigate the hematologic changes and the activities of jellyfish venoms other than hemolytic and cardiovascular toxicities, the acute toxicity of tentacle-only extract (TOE from the jellyfish Cyanea capillata was observed in mice, and hematological indexes were examined in rats. The median lethal dose (LD50 of TOE was 4.25 mg/kg, and the acute toxicity involved both heart- and nervous system-related symptoms. Arterial blood gas indexes, including pH, PCO2, HCO3−, HCO3std, TCO2, BEecf and BE (B, decreased significantly. PO2 showed a slight increase, while SO2c (% had no change at any time. Na+ and Ca2+ decreased, but K+ increased. Biochemical indexes, including LDH, CK, CK-MB, ALT, AST and sCr, significantly increased. Other biochemical indexes, including BUN and hemodiastase, remained normal. Lactic acid significantly increased, while glucose, Hct% and THbc showed slight temporary increases and then returned to normal. These results on the acute toxicity and hematological changes should improve our understanding of the in vivo pathophysiological effects of TOE from C. capillata and indicate that it may also have neurotoxicity, liver toxicity and muscular toxicity in addition to hemolytic and cardiovascular toxicities, but no kidney or pancreatic toxicity.

  18. Reversing the Life Cycle: Medusae Transforming into Polyps and Cell Transdifferentiation in Turritopsis nutricula (Cnidaria, Hydrozoa)

    National Research Council Canada - National Science Library

    Stefano Piraino; Ferdinando Boero; Brigitte Aeschbach; Volker Schmid

    1996-01-01

    .... All stages of the medusa Turritopsis nutricula, from newly liberated to fully mature individuals, can transform back into colonial hydroids, either directly or through a resting period, thus escaping...

  19. Adaptive behaviours of the jellyfish Aurelia labiata in Roscoe Bay on the west coast of Canada

    Science.gov (United States)

    Albert, David J.

    2008-04-01

    Four behaviours of mature Aurelia labiata medusae (Scyphozoa) were observed. Touching the manubrium with a soft, hollow, silicone rubber ball or a foam rubber ball caused medusae at a depth of 1 m to swim to the surface. Dense aggregations of medusae did not form within 5 m of rock walls. Medusae did not swim into water with salinity Aurelia labiata medusae.

  20. Mechanism of endothelial nitric oxide synthase phosphorylation and activation by tentacle extract from the jellyfish Cyanea capillata

    Directory of Open Access Journals (Sweden)

    Beilei Wang

    2017-04-01

    Full Text Available Our previous study demonstrated that tentacle extract (TE from the jellyfish Cyanea capillata (C. capillata could cause a weak relaxation response mediated by nitric oxide (NO using isolated aorta rings. However, the intracellular mechanisms of TE-induced vasodilation remain unclear. Thus, this study was conducted to examine the role of TE on Akt/eNOS/NO and Ca2+ signaling pathways in human umbilical vein endothelial cells (HUVECs. Our results showed that TE induced dose- and time-dependent increases of eNOS activity and NO production. And TE also induced Akt and eNOS phosphorylation in HUVECs. However, treatment with specific PI3-kinase inhibitor (Wortmannin significantly inhibited the increases in NO production and Akt/eNOS phosphorylation. In addition, TE also stimulated an increase in the intracellular Ca2+ concentration ([Ca2+]i, which was significantly attenuated by either IP3 receptor blocker (Heparin or PKC inhibitor (PKC 412. In contrast, extracellular Ca2+-free, L-type calcium channel blocker (Nifedipine, or PKA inhibitor (H89 had no influence on the [Ca2+]i elevation. Since calcium ions also play a critical role in stimulating eNOS activity, we next explored the role of Ca2+ in TE-induced Akt/eNOS activation. In consistent with the attenuation of [Ca2+]i elevation, we found that Akt/eNOS phosphorylation was also dramatically decreased by Heparin or PKC 412, but not affected by Nifedipine or H89. However, the phosphorylation level could also be decreased by the removal of extracellular calcium. Taken together, our findings indicated that TE-induced eNOS phosphorylation and activation were mainly through PI3K/Akt-dependent, PKC/IP3R-sensitive and Ca2+-dependent pathways.

  1. Monodisc strobilation in Japanese giant box jellyfish Morbakka virulenta (Kishinouye, 1910): a strong implication of phylogenetic similarity between Cubozoa and Scyphozoa.

    Science.gov (United States)

    Toshino, Sho; Miyake, Hiroshi; Ohtsuka, Susumu; Adachi, Aya; Kondo, Yusuke; Okada, Shoma; Hirabayashi, Takeshi; Hiratsuka, Tatsuya

    2015-01-01

    Both sexes of the Japanese giant box jellyfish Morbakka virulenta were collected from the Seto Inland Sea, western Japan in December 2011, in order to observe the developmental processes from polyps to medusae. The medusa production in M. virulenta is up to now a unique process in cubozoans in that it exhibits a form of monodisc strobilation where the polyp is regenerated before the medusa detaches. This mode of medusa production was previously thought to be exclusive to scyphozoans. The general shape of young medusae resembles that of other cubozoans such as Alatina moseri and Copula sivickisi, but is differentiated from these by the short capitate tentacles and the lack of gastric filaments in the stomach. The unique medusa production of M. virulenta highly implies a phylogenetic similarity between cubozoans and scyphozoans.

  2. Growth, development and temporal variation in the onset of six Chironex fleckeri medusae seasons: a contribution to understanding jellyfish ecology.

    Directory of Open Access Journals (Sweden)

    Matthew Gordon

    Full Text Available Despite the worldwide distribution, toxicity and commercial, industrial and medical impacts jellyfish present, many aspects of their ecology remain poorly understood. Quantified here are important ecological parameters of Chironex fleckeri medusae, contributing not only to the understanding of an understudied taxon, the cubozoa, but also to the broader understanding of jellyfish ecology. C. fleckeri medusae were collected across seven seasons (1999, 2000, 2003, 2005-07 and 2010, with growth rates, temporal variation in the medusae season onset and differences in population structure between estuarine and coastal habitats quantified. With a mean of 2 September ± 2 d (mean ± 95% confidence limits, the earliest date of metamorphosis was temporally constrained between seasons, varying by only 7 d (30 August to 5 September. Juvenile medusae appeared to be added over an extended period, suggesting polyp metamorphosis was an ongoing process once it commenced. At a maximum of 3 ± 0.2 mm d(-1 IPD, medusae growth to an asymptotic size of ~190 mm IPD was rapid, yet, with the oldest medusae estimated to be ~78 d in age, medusae did not appear to accumulate along the coastline. Furthermore, a greater proportion of juveniles were observed along the coastline, with estuarine populations typified by larger medusae. With key aspects of C. fleckeri's ecology now quantified, medusae season management protocols can be further developed.

  3. Growth, development and temporal variation in the onset of six Chironex fleckeri medusae seasons: a contribution to understanding jellyfish ecology.

    Science.gov (United States)

    Gordon, Matthew; Seymour, Jamie

    2012-01-01

    Despite the worldwide distribution, toxicity and commercial, industrial and medical impacts jellyfish present, many aspects of their ecology remain poorly understood. Quantified here are important ecological parameters of Chironex fleckeri medusae, contributing not only to the understanding of an understudied taxon, the cubozoa, but also to the broader understanding of jellyfish ecology. C. fleckeri medusae were collected across seven seasons (1999, 2000, 2003, 2005-07 and 2010), with growth rates, temporal variation in the medusae season onset and differences in population structure between estuarine and coastal habitats quantified. With a mean of 2 September ± 2 d (mean ± 95% confidence limits), the earliest date of metamorphosis was temporally constrained between seasons, varying by only 7 d (30 August to 5 September). Juvenile medusae appeared to be added over an extended period, suggesting polyp metamorphosis was an ongoing process once it commenced. At a maximum of 3 ± 0.2 mm d(-1) IPD, medusae growth to an asymptotic size of ~190 mm IPD was rapid, yet, with the oldest medusae estimated to be ~78 d in age, medusae did not appear to accumulate along the coastline. Furthermore, a greater proportion of juveniles were observed along the coastline, with estuarine populations typified by larger medusae. With key aspects of C. fleckeri's ecology now quantified, medusae season management protocols can be further developed.

  4. Induction of metamorphosis from the larval to the polyp stage is similar in Hydrozoa and a subgroup of Scyphozoa (Cnidaria, Semaeostomeae)

    Science.gov (United States)

    Siefker, Barbara; Kroiher, Michael; Berking, Stefan

    2000-12-01

    Larvae of cnidarians need an external cue for metamorphosis to start. The larvae of various hydrozoa, in particular of Hydractinia echinata, respond to Cs+, Li+, NH4 + and seawater in which the concentration of Mg2+ ions is reduced. They further respond to the phorbolester, tetradecanoyl-phorbol-13-acetate (TPA) and the diacylglycerol (DAG) diC8, which both are argued to stimulate a protein kinase C. The only well-studied scyphozoa, Cassiopea spp., respond differently, i.e. to TPA and diC8 only. We found that larvae of the scyphozoa Aurelia aurita, Chrysaora hysoscella and Cyanea lamarckii respond to all the compounds mentioned. Trigonelline ( N-methylnicotinic acid), a metamorphosis inhibitor found in Hydractinia larvae, is assumed to act by delivering a methyl group for transmethylation processes antagonising metamorphosis induction in Chrysaora hysoscella and Cyanea lamarckii. The three species tested are scyphozoa belonging to the subgroup of semaeostomeae, while Cassiopea spp. belong to the rhizostomeae. The results obtained may contribute to the discussion concerning the evolution of cnidarians and may help to clarify whether the way metamorphosis can be induced in rhizostomeae as a whole is different from that in hydrozoa and those scyphozoa belonging to the subgroup semaeostomeae.

  5. Aurelia labiata (Scyphozoa) jellyfish in Roscoe Bay: Their spatial distribution varies with population size and their behaviour changes with water depth

    Science.gov (United States)

    Albert, David J.

    2009-02-01

    During 2003 and 2004, there were large numbers of Aurelia labiata medusae in Roscoe Bay and they distributed themselves across the entire bay. A smaller population present during 2006 and 2007 typically formed an aggregation in the west half of the bay. Since currents would have been the same during these two time periods, the behaviour of medusae must have influenced their distribution. The way medusae spaced themselves in aggregations appeared to interact with tidal currents to produce the difference in medusae distribution during the two time periods. In a second series of observations, I found that medusae were not stranded on a Roscoe Bay beach by ebb tides. When the depth of the water column declined to about 1 m or less, medusae in an intertidal zone dove down and bumped into the bottom or swam into rocks or oysters. Their response to these collisions was to swim to the surface or within a few centimetres of the surface. Since the ebb stream was at the surface, being at the surface increased the probability that medusae drifted out of the intertidal zone. The influence of medusae behaviour on their distribution and on their avoidance of stranding is a further indication of the importance of adaptive behaviour in the ecology of Aurelia labiata medusae.

  6. JellyWeb: an interactive information system on Scyphozoa, Cubozoa and Staurozoa.

    Science.gov (United States)

    Martellos, Stefano; Ukosich, Luca; Avian, Massimo

    2016-01-01

    Identification of organisms is traditionally based on the use of "classic" identification keys, normally printed on paper. These keys have several drawbacks: they are mainly based on the systematics, requiring identification of orders, families and genera at first; they are written by experts for other experts, in a specific scientific jargon; they have a "frozen" structure (sequence of theses/antitheses); once published, they cannot be changed or updated without printing a new edition. Due to the use of computers, it is now possible to build new digital identification tools, which: 1) can be produced automatically, if the characters are stored in a database; 2) can be freed from the traditional systematics, giving priority to easy-to-observe characters, incl. those usually uncommon to the classical keys, such as ecology and distribution; 3) can be updated in real time once published on-line; 4) can be available on different media, and on mobile devices. An important feature of these new digital tools is their "collaborative" nature. They can be enriched by the contribution of several researchers, which can cooperate while maintaining rights and property of the resources and data they contribute to the system. JellyWeb, the information system on Scyphozoa, Cubozoa and Staurozoa has been developed in Trieste since 2010. The system was created with the aim of - potentially - becoming a starting point for a wide collaborative effort in developing a user-friendly worldwide digital identification system for jellyfishes.

  7. Early development, pattern, and reorganization of the planula nervous system in Aurelia (Cnidaria, Scyphozoa).

    Science.gov (United States)

    Nakanishi, Nagayasu; Yuan, David; Jacobs, David K; Hartenstein, Volker

    2008-10-01

    We examined the development of the nervous system in Aurelia (Cnidaria, Scyphozoa) from the early planula to the polyp stage using confocal and transmission electron microscopy. Fluorescently labeled anti-FMRFamide, antitaurine, and antityrosinated tubulin antibodies were used to visualize the nervous system. The first detectable FMRFamide-like immunoreactivity occurs in a narrow circumferential belt toward the anterior/aboral end of the ectoderm in the early planula. As the planula matures, the FMRFamide-immunoreactive cells send horizontal processes (i.e., neurites) basally along the longitudinal axis. Neurites extend both anteriorly/aborally and posteriorly/orally, but the preference is for anterior neurite extension, and neurites converge to form a plexus at the aboral/anterior end at the base of the ectoderm. In the mature planula, a subset of cells in the apical organ at the anterior/aboral pole begins to show FMRFamide-like and taurine-like immunoreactivity, suggesting a sensory function of the apical organ. During metamorphosis, FMRFamide-like immunoreactivity diminishes in the ectoderm but begins to occur in the degenerating primary endoderm, indicating that degenerating FMRFamide-immunoreactive neurons are taken up by the primary endoderm. FMRFamide-like expression reappears in the ectoderm of the oral disc and the tentacle anlagen of the growing polyp, indicating metamorphosis-associated restructuring of the nervous system. These observations are discussed in the context of metazoan nervous system evolution.

  8. Medusa as the story of Victorian feminine identity

    Directory of Open Access Journals (Sweden)

    Simona Catrinel Avarvarei

    2015-12-01

    Full Text Available This paper scans the meandering paths of a quest through the realms of womanly self and its articulateness in (robust constructs of individuality. We have departed from a paradigm of interpretation related to a mythological figure, dual in itself, namely the Medusa, perceived as either mask, or face which has always fascinated with her tragic beauty. It is within the semantics of the word fascinum charm, evil spirit but also virile member where the attributes of an age, the Victorian time, that was equally fascinating, as it was whirling and powerful, lie hidden. This paper focuses on artistic reflections of Victorian femininity in an effort to examine how it contributed to the ever-changing definition and search of female gender identities at times of hegemonic masculinities. Art and fiction articulate some of the more powerful challenges. If philosophy encapsulates phallogocentrism, as Derrida points out, fiction, he claims, is an invagination, namely a creation of differences where no term spells self-sufficiency. Thus, whereas philosophy may be seen as the very core of the canon, literature builds a bridge for women to challenge the vastness of terrains of male utterance.

  9. Complex molecular gas structure in the Medusa merger

    CERN Document Server

    Aalto, S

    2000-01-01

    High resolution OVRO aperture synthesis maps of the 12CO 1-0 emission in the `Medusa' galaxy merger (NGC4194) reveal the molecular emission being surprisingly extended. It is distributed on a total scale of 25$''$ (4.7 kpc) - despite the apparent advanced stage of the merger. The complex, striking CO morphology occupies mainly the center and the north-eastern part of the main optical body. The extended 12CO flux is tracing two prominent dust lanes: one which is crossing the central region at right angle and a second which curves to the north-east and then into the beginning of the northern tidal tail. The bulk of the 12CO emission (67%) can be found in a complex starburst region encompassing the central 2kpc. The molecular gas is distributed in five major emission regions of typical size 300pc. About 15% of the total 12CO flux is found in a bright region 1.5'' south of the radio continuum nucleus. We suggest that this region together with the kpc sized central starburst is being fueled by gas flows along the ...

  10. Casulo-ontem: breve análise de Medusa

    Directory of Open Access Journals (Sweden)

    Emaxsuel Roger Rodrigues

    2008-10-01

    Full Text Available http://dx.doi.org/10.5007/1984-784x.2008v8n12p66 Há quase uma década poderíamos encontrar o primeiro volume desse casulo do tempo2. Uma revista para compartilhar o espaço com outras e concorrer com elas em filosofias, escolhas, irreverências. Há quase uma década surgia no cenário nacional o resultado de um projeto de parceria entre três poetas (Ricardo Corona, Ademir Assunção, Rodrigo Garcia Lopes e uma artista plástica (Eliana Borges. Projeto esse de nome “Medusa Revista de poesia e arte”. Uma revista sobre poesia e arte nesses tempos de cultura de massa, nesses tempos de internet, nesses tempos em que tudo é possível de ser divulgado ao grande público e ser acessado por ele; nesses tempos em que ainda se refletem badalações críticas e poéticas ocorridas em décadas passadas.

  11. Casulo-ontem: breve análise de Medusa

    Directory of Open Access Journals (Sweden)

    Emaxsuel Roger Rodrigues

    2008-12-01

    Full Text Available Há quase uma década poderíamos encontrar o primeiro volume desse casulo do tempo2. Uma revista para compartilhar o espaço com outras e concorrer com elas em filosofias, escolhas, irreverências. Há quase uma década surgia no cenário nacional o resultado de um projeto de parceria entre três poetas (Ricardo Corona, Ademir Assunção, Rodrigo Garcia Lopes e uma artista plástica (Eliana Borges. Projeto esse de nome “Medusa Revista de poesia e arte”. Uma revista sobre poesia e arte nesses tempos de cultura de massa, nesses tempos de internet, nesses tempos em que tudo é possível de ser divulgado ao grande público e ser acessado por ele; nesses tempos em que ainda se refletem badalações críticas e poéticas ocorridas em décadas passadas.

  12. Can Aurelia (Cnidaria, Scyphozoa species be differentiated by comparing their scyphistomae and ephyrae?

    Directory of Open Access Journals (Sweden)

    Maria Gambill

    2014-12-01

    Full Text Available Debate exists regarding the number of species of the moon jellyfish (genus Aurelia, a common member of the planktonic community of the coastal shelf seas around the world. Three Aurelia congeners (A. aurita, A. labiata and A. limbata are currently considered to exist but recent genetic analyses suggested that this is an oversimplification. We analyzed the morphological characteristics of scyphistomae, morphological characteristics of ephyrae and differences in the time span of the strobilation process of Aurelia congeners from 17, 7 and 6 different source populations, respectively, of known species. Morphological characteristics of scyphistomae were similar among the 17 populations but those of ephyrae, such as the shape and form of lappets, were effective discriminators in the 6 cases examined. We recommend identifying species based on differences in 1 the morphological characteristics of scyphistomae and ephyrae (and not only medusae, 2 the genetics of individuals, and 3 the geographical occurrence of the population. This study adds to the growing body of knowledge on scyphozoan scyphistomae and ephyrae, stages of the metagenic life cycle of scyphozoans that have received relatively little study compared to medusae.

  13. Review on Medusa:a polymer-based sustained release technology for protein and peptide drugs.

    Science.gov (United States)

    Chan, Y-P; Meyrueix, R; Kravtzoff, R; Nicolas, F; Lundstrom, K

    2007-07-01

    The polymer-based Medusa system (Flamel Technologies) has been designed for slow release of therapeutic proteins and peptides. The Medusa II consists of a poly L-glutamate backbone grafted with hydrophobic alpha-tocopherol molecules, creating a colloidal suspension of nanoparticles (10 - 50 nm) in water. The sustained drug release is based on reversible drug interactions with hydrophobic nanodomains within the nanoparticles. In vivo, it is suggested that the therapeutic protein is displaced by endogenous proteins present in physiological fluids, leading to a slow drug release. The peak concentration is dramatically decreased and the protein release substantially extended. The Medusa technology has been applied to subcutaneous injection for several therapeutic proteins, such as IL-2 and IFN-alpha(2b), in animal models (rats, dogs, monkeys) and clinical trials in renal cancer (IL-2) and hepatitis C (IFN-alpha(2b)) patients.

  14. [Protein composition of mesoglea and mesogloeal cells of medusa Aurelia aurita].

    Science.gov (United States)

    Shaposhnikova, T G; Napara, T O; Podgornaia, O I

    2002-01-01

    Protein composition of mesoglea of the scyphomedusa Aurelia aurita was revealed in SDS-PAGE. Some major bands are visible in mesoglea of a mature medusa: 30, 45-47, 85 kDa, three bands between 100-200 kDa, and several bands with molecular weights > 300 kDa. Polyclonal antisera RA45/47 against protein 45 kDa were raised. RA45/47 react with 45-47 kDa protein in mesogleal sample and protein 120 kDa in mesogleal cells on immunoblot. Immunohistochemical analysis of A. aurita histological sections of young and mature medusae showed antigen localization in mesogleal cell granules and in the apical part of ectodermal cells. In mature medusae, the antigen was localized also in elastic fibers. We can conclude that in A. aurita mesogleal cells, along with ectodermal cells, take part in the formation of extracellular matrix of mesoglea.

  15. Medusa: a novel gene drive system for confined suppression of insect populations.

    Directory of Open Access Journals (Sweden)

    John M Marshall

    Full Text Available Gene drive systems provide novel opportunities for insect population suppression by driving genes that confer a fitness cost into pest or disease vector populations; however regulatory issues arise when genes are capable of spreading across international borders. Gene drive systems displaying threshold properties provide a solution since they can be confined to local populations and eliminated through dilution with wild-types. We propose a novel, threshold-dependent gene drive system, Medusa, capable of inducing a local and reversible population crash. Medusa consists of four components--two on the X chromosome, and two on the Y chromosome. A maternally-expressed, X-linked toxin and a zygotically-expressed, Y-linked antidote results in suppression of the female population and selection for the presence of the transgene-bearing Y because only male offspring of Medusa-bearing females are protected from the effects of the toxin. At the same time, the combination of a zygotically-expressed, Y-linked toxin and a zygotically-expressed, X-linked antidote selects for the transgene-bearing X in the presence of the transgene-bearing Y. Together these chromosomes create a balanced lethal system that spreads while selecting against females when present above a certain threshold frequency. Simple population dynamic models show that an all-male release of Medusa males, carried out over six generations, is expected to induce a population crash within 12 generations for modest release sizes on the order of the wild population size. Re-invasion of non-transgenic insects into a suppressed population can result in a population rebound; however this can be prevented through regular releases of modest numbers of Medusa males. Finally, we outline how Medusa could be engineered with currently available molecular tools.

  16. Cardiovascular effect is independent of hemolytic toxicity of tentacle-only extract from the jellyfish Cyanea capillata.

    Directory of Open Access Journals (Sweden)

    Xiao Liang

    Full Text Available Our previous studies have confirmed that the crude tentacle-only extract (cTOE from the jellyfish Cyanea capillata (Cyaneidae exhibits hemolytic and cardiovascular toxicities simultaneously. So, it is quite difficult to discern the underlying active component responsible for heart injury caused by cTOE. The inactivation of the hemolytic toxicity from cTOE accompanied with a removal of plenty of precipitates would facilitate the separation of cardiovascular component and the investigation of its cardiovascular injury mechanism. In our research, after the treatment of one-step alkaline denaturation followed by twice dialysis, the protein concentration of the treated tentacle-only extract (tTOE was about 1/3 of cTOE, and SDS-PAGE showed smaller numbers and lower density of protein bands in tTOE. The hemolytic toxicity of tTOE was completely lost while its cardiovascular toxicity was well retained. The observations of cardiac function, histopathology and ultrastructural pathology all support tTOE with significant cardiovascular toxicity. Blood gas indexes and electrolytes changed far less by tTOE than those by cTOE, though still with significant difference from normal. In summary, the cardiovascular toxicity of cTOE can exist independently of the hemolytic toxicity and tTOE can be employed as a better venom sample for further purification and mechanism research on the jellyfish cardiovascular toxic proteins.

  17. Expression of Wnt pathway genes in polyps and medusa-like structures of Ectopleura larynx (Cnidaria: Hydrozoa).

    Science.gov (United States)

    Nawrocki, Annalise M; Cartwright, Paulyn

    2013-01-01

    The canonical Wnt signaling pathway is conserved in its role in axial patterning throughout Metazoa. In some hydrozoans (Phylum Cnidaria), Wnt signaling is implicated in oral-aboral patterning of the different life cycle stages-the planula, polyp and medusa. Unlike most hydrozoans, members of Aplanulata lack a planula larva and the polyp instead develops directly from a brooded or encysted embryo. The Aplanulata species Ectopleura larynx broods such embryos within gonophores. These gonophores are truncated medusae that remain attached to the polyps from which they bud, and retain evolutionary remnants of medusa structures. In E. larynx, gonophores differ between males and females in their degree of medusa truncation, making them an ideal system for examining truncated medusa development. Using next-generation sequencing, we isolated genes from Wnt signaling pathways and examined their expression in E. larynx. Our data are consistent with the Wnt pathway being involved in axial patterning of the polyp and truncated medusa. Changes in the spatial expression of Wnt pathway genes are correlated with the development of different oral structures in male and female gonophores. The absence of expression of components of the Wnt pathway and presence of a Wnt pathway antagonist SFRP in the developing anterior end of the gonophore suggest that downregulation of the Wnt pathway could play a role in medusa reduction in E. larynx. © 2013 Wiley Periodicals, Inc.

  18. Global Transcriptome Analysis of the Tentacle of the Jellyfish Cyanea capillata Using Deep Sequencing and Expressed Sequence Tags: Insight into the Toxin- and Degenerative Disease-Related Transcripts.

    Directory of Open Access Journals (Sweden)

    Guoyan Liu

    Full Text Available Jellyfish contain diverse toxins and other bioactive components. However, large-scale identification of novel toxins and bioactive components from jellyfish has been hampered by the low efficiency of traditional isolation and purification methods.We performed de novo transcriptome sequencing of the tentacle tissue of the jellyfish Cyanea capillata. A total of 51,304,108 reads were obtained and assembled into 50,536 unigenes. Of these, 21,357 unigenes had homologues in public databases, but the remaining unigenes had no significant matches due to the limited sequence information available and species-specific novel sequences. Functional annotation of the unigenes also revealed general gene expression profile characteristics in the tentacle of C. capillata. A primary goal of this study was to identify putative toxin transcripts. As expected, we screened many transcripts encoding proteins similar to several well-known toxin families including phospholipases, metalloproteases, serine proteases and serine protease inhibitors. In addition, some transcripts also resembled molecules with potential toxic activities, including cnidarian CfTX-like toxins with hemolytic activity, plancitoxin-1, venom toxin-like peptide-6, histamine-releasing factor, neprilysin, dipeptidyl peptidase 4, vascular endothelial growth factor A, angiotensin-converting enzyme-like and endothelin-converting enzyme 1-like proteins. Most of these molecules have not been previously reported in jellyfish. Interestingly, we also characterized a number of transcripts with similarities to proteins relevant to several degenerative diseases, including Huntington's, Alzheimer's and Parkinson's diseases. This is the first description of degenerative disease-associated genes in jellyfish.We obtained a well-categorized and annotated transcriptome of C. capillata tentacle that will be an important and valuable resource for further understanding of jellyfish at the molecular level and information

  19. Studies on breeding shorebirds at Medusa Bay, Taimyr, in summer 2001

    NARCIS (Netherlands)

    Tulp, I.; Schekkerman, H.

    2001-01-01

    In the Summer of 2001 a combined Dutch-Russian expedition took place to the Willem Barentz field station at Medusa Bay near Dikson in north-western Taimyr. The expedition was organized by Alterra, the Working Group for International Waterbird and Wetland Research (WIWO) and the Agricultural Departme

  20. Studies on breeding shorebirds at Medusa Bay, Taimyr, in Summer 2000

    NARCIS (Netherlands)

    Tulp, I.; Schekkerman, H.; Klaassen, R.

    2000-01-01

    In the Summer of 2000 a combined Dutch-Russian expedition took place to the Willem Barentz field station at Medusa Bay near Dikson in north-western Taimyr. The expedition was organized by Alterra, the Working Group for International Waterbird and Wetland Research (WIWO) and the Dutch Agricultural De

  1. The MEDUSA electron and ion spectrometer and the PIA ultraviolet photometers on Astrid-2

    Directory of Open Access Journals (Sweden)

    O. Norberg

    Full Text Available The miniature electron and ion spectrometer MEDUSA on Astrid-2 consists of two "top-hat"-type spherical electrostatic analyzers, sharing a common top-hat. Fast energy sweeps (16 electron sweeps and 8 ion sweeps per second allow for very high temporal resolution measurements of a two-dimensional slice of the particle distribution function. The energy range covered, is in the case of electrons, 4 eV to 22 keV and, in the case of ions, 2 eV to 12 keV. MEDUSA is mounted with its aperture close to the spin plane of Astrid-2, which allows for good pitch-angle coverage when the local magnetic field is in the satellite spin plane. The PIA-1/2 spin-scanning ultraviolet photometers measure auroral emissions. Using the spacecraft spin and orbital motion, it is possible to create two-dimensional images from the data. Spin-scanning photometers, such as PIA, are low-cost, low mass alternatives to auroral imagers, but place constraints on the satellite attitude. Data from MEDUSA are used to study processes in the auroral region, in particular, electrodynamics of aurora and "black aurora". MEDUSA is also a technological development, paving the way for highly capable, miniaturized particle spectrometers.

    Key words. Ionosphere (instruments and techniques – Magnetospheric physics (auroral phenomena; instruments and techniques

  2. Estimation of the minimum food requirement using the respiration rate of medusa of Aurelia aurita in Sihwa Lake

    Science.gov (United States)

    Han, Chang-hoon; Chae, Jinho; Jin, Jonghyeok; Yoon, Wonduk

    2012-06-01

    We examined the respiration rate of Aurelia aurita medusae at 20 °C and 28 °C to evaluate minimum metabolic demands of medusae population in Sihwa Lake, Korea during summer. While weight specific respiration rates of medusae were constant and irrespective to the wet weight (8-220 g), they significantly varied in respect to temperatures ( p<0.001, 0.11±0.03 mg C g-1 of medusa d-1 at 20°C and 0.28±0.11 mg C g-1 of medusa d-1 at 28 °C in average, where Q 10 value was 2.62). The respiration rate of medusae was defined as a function of temperature ( T, °C) and body weight ( W, g) according to the equation, R=0.13×2.62( T-20)/10 W 0.93. Population minimum food requirement ( PMFR) was estimated from the respiration rate as 15.06 and 4.86 mg C m-3 d-1 in June and July, respectively. During this period, increase in bell diameter and wet weight was not significant ( p=1 in the both), suggesting that the estimated PMFR closely represented the actual food consumption in the field. From July to August, medusae grew significantly at 0.052 d-1, thus the amount of food ingested by medusae population in situ was likely to exceed the PMFR (1.27 mg C m-3 d-1) during the period. In conclusion, the medusae population of higher density during June and July had limited amount of food, while those of lower in July and August ingested enough food for growth.

  3. Patterns of Wnt signaling in the life cycle of Podocoryna carnea and its implications for medusae evolution in Hydrozoa (Cnidaria).

    Science.gov (United States)

    Sanders, Steven M; Cartwright, Paulyn

    2015-01-01

    Hydrozoans are known for their complex life cycles, alternating between benthic, asexually reproducing polyps and pelagic, sexually reproducing medusae. Although patterning in hydrozoan polyps has been well studied, little is known about the signaling mechanisms governing medusa development. In order to investigate the role of Wnt signaling in medusa development, we use RNA-Seq data collected from three discrete life cycle stages of Podocoryna carnea to assemble, annotate, and assess enrichment and differential expression (DE) of Wnt pathway elements in P. carnea's transcriptome. Enrichment analyses revealed a statistically significant enrichment of DE Wnt signaling transcripts in the transcriptome of P. carnea, of which, the vast majority of these were significantly up-regulated in developing and adult medusae stages. Whole mount in situ hybridization (ISH) reveals co-expression of the Wnt ligand, Wnt3, and a membrane bound Wnt receptor, frizzled3, at the distal and oral ends of the developmental axes of medusae and polyps in P. carnea. DE and ISH results presented here reveal expression of Wnt signaling components consistent with it playing a role in medusa development. Specifically, Wnt ligand expression in the oral region suggests that the Wnt pathway may play a role in medusa patterning, similar to that of polyps. Previous Wnt expression studies in hydrozoan taxa with reduced medusa have failed to detect co-expression of Wnt3 and a frizzled receptor at their truncated developmental axes, suggesting that down regulation of Wnt pathway elements may play a key role in the loss of the medusa life cycle stage in hydrozoan evolution. © 2015 Wiley Periodicals, Inc.

  4. Genetic diversity and pathogenicity of Metarhizium spp. associated with the white grub Phyllophaga capillata (Blanchard) (Coleoptera: Melolonthidae) in a soybean field.

    Science.gov (United States)

    Lopes, R B; Souza, D A; Oliveira, C M; Faria, M

    2013-08-01

    Phyllophaga capillata (Blanchard) was recently described as a soybean pest in Brazil. The occurrence of Metarhizium spp. associated with adults and their pathogenicity were investigated. Natural prevalence of Metarhizium anisopliae was 0.51% in adults collected by light trap. Most Metarhizium isolates were identified as Metarhizium robertsii, although M. anisopliae sensu stricto and a few unidentified isolates were also found. Bioassays with representative isolates selected from different genetic groups resulted in ≤5.6% confirmed mortality against larvae and adults, suggesting low potential of microbial control of this pest by use of indigenous Metarhizium isolates.

  5. Neritic Jellyfishes (Cnidaria: Cubozoa and Scyphozoa from the coast of Rio Grande do Norte state, northeast of Brazil

    Directory of Open Access Journals (Sweden)

    Matthews-Cascon, H.

    2009-01-01

    Full Text Available For the entire Brazilian coast, there are 22 published records of scyphozoans. On the other hand, only 35 species ofcubozoans were described worldwide, four of them reported for the Brazilian coast. However, little is known about thespecies of cubozoans and scyphozoans in the Northeastern states of Brazil. The aim of this study was to perform asurvey of the jellyfish (Cnidaria: Cubozoa and Scyphozoa on the coast of Rio Grande do Norte state, Northeast ofBrazil. Specimens were collected using trawl net on beaches in the counties of Natal (in 2003 and Tibaú (in 2004. Forthe Rio Grande do Norte coast there were few records of large jellyfish, and new records of the following cubozoan andscyphozoan species were verified: Chiropsalmus quadrumanus; Chrysaora lactea; Lychnorhiza lucerna andStomolophus meleagris. The studied species had their distributions expanded in the coast to the State of Rio Grande doNorte.

  6. Lychnorhiza lucerna Haeckel (Scyphozoa, Rhizostomeae and Libinia ferreirae Brito Capello (Decapoda, Majidae association in southern Brazil Associação entre Lychnorhiza lucerna Haeckel (Scyphozoa, Rhizostomeae e Libinia ferreirae Brito Capello (Decapoda, Majidae no sul do Brasil

    Directory of Open Access Journals (Sweden)

    Miodeli Nogueira Júnior

    2005-12-01

    Full Text Available Associations between jellyfish and other organisms are frequently reported. Neverhteless, few of those records include crabs inhabiting medusae. Lychnorhiza lucerna Haeckel, 1888 were sampled (n = 1988 on the coast of the State of Paraná (25º20'-25º55'S, 48º10'-48º35'W, southern Brazil, from December 1997 to December 2004. Eight percent (166 individuals of the medusae had one spider crab Libinia ferreirae Brito Capello, 1871 living within its subgenital porticus or on the oral arms. Megalopal stages of the same crab were also found on three jellyfish. All crabs associated with L. lucerna were young and smaller (Associações entre medusas e diversos outros organismos são freqüentemente relatadas. Entretanto sobre caranguejos que vivem em águas-vivas apenas alguns registros foram encontrados. Entre dezembro de 1997 e dezembro de 2004, foram coletados 1988 exemplares de Lychnorhiza lucerna Haeckel, 1888 na costa do Estado do Paraná (25º20'-25º55'S, 48º10'-48º35'W, Sul do Brasil. Oito por cento (166 indivíduos das medusas abrigavam um caranguejo aranha Libinia ferreirae Brito Capello, 1871 no interior de seu pórtico subgenital ou sobre seus braços orais. Megalopas da mesma espécie também foram encontradas em três exemplares de L. lucerna. Todos os caranguejos encontrados associados eram jovens e menores (< 3 cm do que os espécimes solitários capturados no fundo. Os resultados indicam que L. ferreirae coloniza a água-viva em sua fase pós-larval e a usa como um criadouro flutuante, antes de se estabelecer no fundo como um caranguejo adulto típico.

  7. First report of a thioredoxin homologue in jellyfish: molecular cloning, expression and antioxidant activity of CcTrx1 from Cyanea capillata.

    Directory of Open Access Journals (Sweden)

    Zengliang Ruan

    Full Text Available Thioredoxins (Trx proteins are a family of small, highly-conserved and ubiquitous proteins that play significant roles in the resistance of oxidative damage. In this study, a homologue of Trx was identified from the cDNA library of tentacle of the jellyfish Cyanea capillata and named CcTrx1. The full-length cDNA of CcTrx1 was 479 bp with a 312 bp open reading frame encoding 104 amino acids. Bioinformatics analysis revealed that the putative CcTrx1 protein harbored the evolutionarily-conserved Trx active site 31CGPC34 and shared a high similarity with Trx1 proteins from other organisms analyzed, indicating that CcTrx1 is a new member of Trx1 sub-family. CcTrx1 mRNA was found to be constitutively expressed in tentacle, umbrella, oral arm and gonad, indicating a general role of CcTrx1 protein in various physiological processes. The recombinant CcTrx1 (rCcTrx1 protein was expressed in Escherichia coli BL21 (DE3, and then purified by affinity chromatography. The rCcTrx1 protein was demonstrated to possess the expected redox activity in enzymatic analysis and protection against oxidative damage of supercoiled DNA. These results indicate that CcTrx1 may function as an important antioxidant in C. capillata. To our knowledge, this is the first Trx protein characterized from jellyfish species.

  8. First report of a thioredoxin homologue in jellyfish: molecular cloning, expression and antioxidant activity of CcTrx1 from Cyanea capillata.

    Science.gov (United States)

    Ruan, Zengliang; Liu, Guoyan; Guo, Yufeng; Zhou, Yonghong; Wang, Qianqian; Chang, Yinlong; Wang, Beilei; Zheng, Jiemin; Zhang, Liming

    2014-01-01

    Thioredoxins (Trx proteins) are a family of small, highly-conserved and ubiquitous proteins that play significant roles in the resistance of oxidative damage. In this study, a homologue of Trx was identified from the cDNA library of tentacle of the jellyfish Cyanea capillata and named CcTrx1. The full-length cDNA of CcTrx1 was 479 bp with a 312 bp open reading frame encoding 104 amino acids. Bioinformatics analysis revealed that the putative CcTrx1 protein harbored the evolutionarily-conserved Trx active site 31CGPC34 and shared a high similarity with Trx1 proteins from other organisms analyzed, indicating that CcTrx1 is a new member of Trx1 sub-family. CcTrx1 mRNA was found to be constitutively expressed in tentacle, umbrella, oral arm and gonad, indicating a general role of CcTrx1 protein in various physiological processes. The recombinant CcTrx1 (rCcTrx1) protein was expressed in Escherichia coli BL21 (DE3), and then purified by affinity chromatography. The rCcTrx1 protein was demonstrated to possess the expected redox activity in enzymatic analysis and protection against oxidative damage of supercoiled DNA. These results indicate that CcTrx1 may function as an important antioxidant in C. capillata. To our knowledge, this is the first Trx protein characterized from jellyfish species.

  9. Growth, Development and Temporal Variation in the Onset of Six Chironex fleckeri Medusae Seasons: A Contribution to Understanding Jellyfish Ecology

    OpenAIRE

    2012-01-01

    Despite the worldwide distribution, toxicity and commercial, industrial and medical impacts jellyfish present, many aspects of their ecology remain poorly understood. Quantified here are important ecological parameters of Chironex fleckeri medusae, contributing not only to the understanding of an understudied taxon, the cubozoa, but also to the broader understanding of jellyfish ecology. C. fleckeri medusae were collected across seven seasons (1999, 2000, 2003, 2005-07 and 2010), with growth ...

  10. Comparative Design Studies for the BESSY FEL Program using the MEDUSA and GENESIS Simulation Codes

    CERN Document Server

    Freund, H

    2005-01-01

    The BESSY FEL is based on a seeded cascade of High Gain Harmonic Generation (HGHG) sections followed by an amplifier to produce coherent and stable short wavelength output. Here, we report on comparative design studies carried out using the MEDUSA [1], and GENESIS [2] simulation codes. These two codes have each been used to successfully predict a variety of FEL designs and have agreed well with a number of important experiments. In addition, they were included in a comparative study of FEL simulation [3] that reported substantial agreement between the codes for the specific configurations studied. However, these codes are based on different assumptions. GENESIS treats the particle dynamics using a wiggler-averaged orbit approximation, the transverse electromagnetic field is treated using a field solver, and harmonics are not included. MEDUSA does not use the wiggler-averaged orbit approximation to treat particle dynamics, the transverse fields are treated using a Gaussian modal superposition, and harmonics ar...

  11. Geologic Mapping of the Medusae Fossae Formation on Mars and the Northern Lowland Plains of Venus

    Science.gov (United States)

    Zimbelman, J. R.

    2009-01-01

    This report summarizes the status of mapping projects supported by NASA grant NNX07AP42G, through the Planetary Geology and Geophysics (PGG) program. The PGG grant is focused on 1:2M-scale mapping of portions of the Medusae Fossae Formation (MFF) on Mars. Also described below is the current status of two Venus geo-logic maps, generated under an earlier PGG mapping grant.

  12. Geologic Mapping of the Medusae Fossae Formation, Mars, and the Northern Lowland Plains, Venus

    Science.gov (United States)

    Zimbelman, J. R.

    2010-01-01

    This report summarizes the status of mapping projects supported by NASA grant NNX07AP42G, through the Planetary Geology and Geophysics (PGG) program. The PGG grant is focused on 1:2M-scale mapping of portions of the Medusae Fossae Formation (MFF) on Mars. Also described below is the current status of two Venus geologic maps, generated under an earlier PGG mapping grant.

  13. Biodiversity and spatial distribution of medusae in the Magellan Region (Southern Patagonian Zone

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    Sergio Palma

    2014-11-01

    Full Text Available Epipelagic medusae collected in the Magellan Region (Southern Patagonian Zone during spring 2009 were analyzed. A total of 27 species of medusae were identified (25 hydromedusae and 2 scyphomedusae. Twelve medusae species were recorded for the first time in the Magellan region. Six dominant species were found: Clytia simplex (19.8%, Rhopalonema funerarium (16.2%, Aurelia sp. (15.9%, Bougainvillia muscoides (15.5%, Proboscidactyla stellata (8.9%, and Obelia spp. (6.0%. The horizontal distribution of all these species, except Obelia spp., showed the highest abundances to the south of 54°S, particularly in the Almirantazgo and Agostini fjords and in the Beagle Channel. Most of the dominant species were collected in shallow strata (0-50 m, with less saline waters (<30, except for R. funerarium, which was mainly collected above depths deeper than 25 m in more saline waters (30-33. These results confirm the success of several species in the colonization of the inland waters of the Southern Patagonian Zone.

  14. The nerve ring in cnidarians: its presence and structure in hydrozoan medusae.

    Science.gov (United States)

    Koizumi, Osamu; Hamada, Shun; Minobe, Sumiko; Hamaguchi-Hamada, Kayoko; Kurumata-Shigeto, Mami; Nakamura, Masaru; Namikawa, Hiroshi

    2015-04-01

    In our previous studies of the Hydra nerve ring, we proposed the following hypothesis: "The nerve ring in the hypostome of Hydra is a central nervous system (CNS)-like neuronal structure." Related to this hypothesis, we have started to survey the nerve ring immunocytochemically using antibodies against neuropeptides throughout the whole phylum of cnidarians. In the present study, we describe nerve rings in hydrozoan medusae. We examined the medusae of five hydrozoan species belonging to three orders: Eirene sp. (order Leptomedusae), Craspedacusta sowerbyi (order Limnomedusae), Sarsia tubulosa, Turritopsis nutricula, and Cladonema radiatum (order Anthomedusae). We observed a well-developed nerve ring in all species. The nerve ring runs circumferentially around the margin of the bell. In all cases, the nerve ring was visualized by plural antibodies, suggesting that it contains different neural subpopulations. In C. radiatum, antibodies against four different neuropeptides labeled the nerve ring. We established clear (without undesirable cross-reactions) double-staining procedures with two rabbit primary antibodies. Using the double-staining method, three neural subsets visualized by three antibodies revealed completely separate neural populations. The results show that the nerve ring is a common feature in hydrozoan medusae and has a complex heterogeneous structure composed of different neural subsets. Copyright © 2014 Elsevier GmbH. All rights reserved.

  15. Nematocyst discharge in Pelagia noctiluca (Cnidaria, Scyphozoa) oral arms can be affected by lidocaine, ethanol, ammonia and acetic acid.

    Science.gov (United States)

    Morabito, Rossana; Marino, Angela; Dossena, Silvia; La Spada, Giuseppa

    2014-06-01

    Nematocyst discharge and concomitant delivery of toxins is triggered to perform both defence and predation strategies in Cnidarians, and may lead to serious local and systemic reactions in humans. Pelagia noctiluca (Cnidaria, Scyphozoa) is a jellyfish particularly abundant in the Strait of Messina (Italy). After accidental contact with this jellyfish, not discharged nematocysts or even fragments of tentacles or oral arms may tightly adhere to the human skin and, following discharge, severely increase pain and the other adverse consequences of the sting. The aim of the present study is to verify if the local anesthetic lidocaine and other compounds, like alcohols, acetic acid and ammonia, known to provide pain relief after jellyfish stings, may also affect in situ discharge of nematocysts. Discharge was induced by a combined physico-chemical stimulation of oral arms by chemosensitizers (such as N-acetylated sugars, aminoacids, proteins and nucleotides), in the presence or absence of 1% lidocaine, 70% ethanol, 5% acetic acid or 20% ammonia, followed by mechanical stimulation by a non-vibrating test probe. The above mentioned compounds failed to induce discharge per se, and dramatically impaired the chemosensitizer-induced discharge response. We therefore suggest that prompt local treatment of the stung epidermis with lidocaine, acetic acid, ethanol and ammonia may provide substantial pain relief and help in reducing possible harmful local and systemic adverse reaction following accidental contact with P. noctiluca specimens.

  16. Heavy Metals Affect Nematocysts Discharge Response and Biological Activity of Crude Venom in the Jellyfish Pelagia noctiluca (Cnidaria, Scyphozoa

    Directory of Open Access Journals (Sweden)

    Rossana Morabito

    2014-07-01

    Full Text Available Background: Pollution of marine ecosystems and, specifically, heavy metals contamination may compromise the physiology of marine animals with events occurring on a cellular and molecular level. The present study focuses on the effect of short-term exposure to heavy metals like Zinc, Cadmium, Cobalt and Lanthanum (2-10 mM on the homeostasis of Pelagia noctiluca (Cnidaria, Scyphozoa, a jellyfish abundant in the Mediterranean sea. This species possesses stinging organoids, termed nematocysts, whose discharge and concomitant delivery of venom underlie the survival of all Cnidaria. Methods: Nematocysts discharge response, elicited by combined chemico-physical stimulation, was verified on excised oral arms exposed to heavy metals for 20 min. In addition, the hemolytic activity of toxins, contained in the crude venom extracted from nematocysts isolated from oral arms, was tested on human erythrocytes, in the presence of heavy metals or their mixture. Results: Treatment with heavy metals significantly inhibited both nematocysts discharge response and hemolytic activity of crude venom, in a dose-dependent manner, not involving oxidative events, that was irreversible in the case of Lanthanum. Conclusion: Our findings show that the homeostasis of Pelagia noctiluca, in terms of nematocysts discharge capability and effectiveness of venom toxins, is dramatically and rapidly compromised by heavy metals and confirm that this jellyfish is eligible as a model for ecotoxicological investigations.

  17. Vertical distribution of Aurelia labiata (Scyphozoa) jellyfish in Roscoe Bay is similar during flood and ebb tides

    Science.gov (United States)

    Albert, David J.

    2010-10-01

    The vertical distribution of the jellyfish, Aurelia labiata, was assessed during flood and ebb tides in April, May, June, and August 2009 in Roscoe Bay (British Columbia, Canada). Assessments were made at locations along the entire length of the bay. The average tide change was 3.7 m. The vertical position of medusae (in 2 m intervals) did not differ significantly during ebb ( N = 17) and flood tides ( N = 18) in 6 and 8 m water columns. These results indicate that A. labiata do not use tidally synchronized vertical migration to maintain their location or presence in Roscoe Bay.

  18. The medusae of some species of Hebella Allman, 1888, and Anthohebella gen. nov. (Cnidaria, Hydrozoa, Lafoeidae), with a world synopsis of species*

    NARCIS (Netherlands)

    Boero, F.; Bouillon, J.; Kubota, S.

    1997-01-01

    The newly liberated, immature medusae of H. scandens, Hebella furax, H. muscensis, and the liberable eumedusoid of H. dyssymetra are described. The taxonomy of the medusa-producing Hebellinae is revised in the light of life cycle features. Due to inconsistencies between skeletal and medusan features

  19. Ionized gas kinematics at high resolution. IV. Star formation and a rotating core in the Medusa (NGC 4194)

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Sara C. [School of Physics and Astronomy, Tel Aviv University, Ramat Aviv 69978 (Israel); Lacy, John [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Turner, Jean [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1547 (United States); Greathouse, Thomas [Southwest Research Institute, San Antonio, TX 78228-0510 (United States); Neff, Susan, E-mail: becksarac@gmail.com [NASA-Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2014-05-20

    NGC 4194 is a post-merger starburst known as The Medusa for its striking tidal features. We present here a detailed study of the structure and kinematics of ionized gas in the central 0.65 kpc of the Medusa. The data include radio continuum maps with resolution up to 0.''18 (35 pc) and a 12.8 μm [Ne II] data cube with spectral resolution ∼4 km s{sup –1}: the first high-resolution, extinction-free observations of this remarkable object. The ionized gas has the kinematic signature of a core in solid-body rotation. The starburst has formed a complex of bright compact H II regions, probably excited by deeply embedded super star clusters, but none of these sources is a convincing candidate for a Galactic nucleus. The nuclei of the merger partners that created the Medusa have not yet been identified.

  20. Ionized Gas Kinematics at High Resolution. IV. Star Formation and a Rotating Core in the Medusa (NGC 4194)

    Science.gov (United States)

    Beck, Sara C.; Lacy, John; Neff, Susan Gale; Turner, Jean; Greathouse, Thomas; Neff, Susan

    2014-01-01

    NGC 4194 is a post-merger starburst known as The Medusa for its striking tidal features.We present here a detailed study of the structure and kinematics of ionized gas in the central 0.65 kpc of the Medusa. The data include radio continuum maps with resolution up to 0".18 (35 pc) and a 12.8 micron [Ne II] data cube with spectral resolution approx. 4 km/s: the first high-resolution, extinction-free observations of this remarkable object. The ionized gas has the kinematic signature of a core in solid-body rotation. The starburst has formed a complex of bright compact H II regions, probably excited by deeply embedded super star clusters, but none of these sources is a convincing candidate for a Galactic nucleus. The nuclei of the merger partners that created the Medusa have not yet been identified.

  1. Picadura de medusa Olindias sambaquiensis: Análisis de 49 casos

    Directory of Open Access Journals (Sweden)

    Juan H Mosovich

    2012-10-01

    Full Text Available La picadura de la medusa o agua viva Olindia sambaquiensis es de ocurrencia frecuente en las playas de la costa de la provincia de Buenos Aires. Se notifican entre quinientas y mil picaduras de medusas por temporada en la localidad balnearia de Monte Hermoso, al sur de la provincia de Buenos Aires. El daño cutáneo que provoca por su elevada acción urticante plantea un serio inconveniente para el desarrollo del turismo. Durante el mes de enero de 1998, en la localidad de Monte Hermoso se reunieron un total de 49 casos que fueron examinados dentro de la hora posterior a la picadura. Veintiocho eran de sexo masculino (57.1%. La edad promedio fue de 16 ± 4.1 (rango 5-80. El 54% presentó lesiones eritemato-edematosas de configuración lineal, el 28% presentó lesiones predominantemente eritematosas y el 18% presentó placas eritemato-edematosas. En el 73% de los casos las lesiones se localizaron en miembros inferiores. Hemos redefinido la lesión cutánea producida por la medusa O. sambaquiensis, su evolución, sus dimensiones y localizaciones más frecuentes. Además, se ha tipificado y cuantificado el dolor que produce, y otros signos y síntomas que acompañan a la picadura en la hora posterior, a las primeras 24 horas y a los 30 días. Describimos las conductas terapéuticas utilizadas en nuestra costa, evaluamos la efectividad de algunas de ellas en el control del dolor y finalmente proponemos un esquema terapéutico para dicha picadura.

  2. Causal analysis of the diversity of medusae in East China Sea

    Institute of Scientific and Technical Information of China (English)

    Zhaoli XU; Mao LIN; Qian GAO

    2008-01-01

    Based on the maritime data collected from 23°30'-33°00' N and 118°30'-128°00' E of the East China Sea (ECS) in four seasons during 1997-2000,the dynamics of medusae diversity and their causes were ana-lyzed.A total of 103 medusae species were identified,and these species mainly distributed in the southern and north-ern offshore areas of the ECS.Species diversity index (H') of medusae was higher in the south than those in the north,higher in summer and winter than in spring and autumn,and higher in offshore than in the nearshore areas.The species number was closely correlated with H' value,whereas the abundance of species had no significant rela-tionship with the diversity index.The lower H' value of the nearshore in spring and autumn resulted from the aggrega-tion of Muggiaea atlantica in the south nearshore and Diphyes chamissonis in the north nearshore.In addition,water temperature,followed by salinity,is the main envir-onmental factor influencing the distribution of species diversity.The H' value was related to the water temperature at the 10 m layer in winter and spring,and it was associated with the surface water temperature in summer and with the 10 m-salinity-layer in autumn.In spring and summer,the isoline distribution of H' value reflected the direction of the Taiwan Warm Current and the variation of the water masses in the ECS.In winter,the isoline of the H' value indicated the incursion of Kuroshio current.In conclusion,the H' isoline is an good indicator for water masses in ECS.

  3. FMRFamide immunoreactivity in the nervous system of the medusa Polyorchis penicillatus

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, C J; Spencer, A N

    1984-01-01

    Three different antisera to the molluscan neuropeptide Phe-Met-Arg-Phe-amide (FMRFamide) and two different antisera to the fragment RFamide were used to stain sections or whole mounts of the hydrozoan medusa Polyorchis penicillatus. All antisera stained the same neuronal structures. Strong immuno...... with several antisera to oxytocin/vasopressin and bombesin/gastrin-releasing peptide. The morphology and location of most FMRFamide-immunoreactive neurons in Polyorchis coincides with two identified neuronal systems, which have been recently discovered from neurophysiological studies....

  4. Trophic Cascading of Medusae on the Relationships between Copepods and Diatoms in a Subtropical Coastal Ecosystem

    Directory of Open Access Journals (Sweden)

    Jia-Lu Chung

    2009-01-01

    Full Text Available To investigate the spatial and temporal variation of phytoplankton and copepods, eight seasonal cruises (January 2005 ~ Oc to ber 2006 were conducted in a subtropical coast site that encom passed 19 sampling stations. The results in dicated that the temperature (18.4 - 29.7°C varied more than 10°C seasonally, while nutrient concentrations (ni trate: 0.4 - 6.3 mM, phosphate: 0.1 - 0.8 mM, and silicate 2.1 - 12.1 mM were in versely corre lated with temperature. Diatoms (2792 - 1602437 cells m-3 constituted > 90% of the phytoplankton as semblages and dinoflagellates (226 - 10029 cells m-3 represented only ~10% of the algaebiomass. Copepod abun dance (8 - 1031 ind. m-3 varied positively with that of diatom and tempeature. Therelative abundance of Temora spp. (1 - 712 ind. m-3 varied from 69% in summer; that of Paracalanus spp. (0.1 - 176 ind. m-3 were > 25% in spring and au tumn and Calanus spp. (0.5 - 24 ind. m-3 dom i nated in win ter and spring, but ac counted for only ~10% of the to tal copepods. Both di a tom den sity and copepod abun dance were positively correlated with temperature, indicating these two plank tongroups were left bot tom-up control. The copepod abun dance positively co-aried with diatoms in 2005, but not in 2006. Fur ther sea son-to-sea son analysis showed that the diatomvs. copepodratios changed positively only when the medusa abun dance changed greatly (> 40-fold between consecutive sea sons. During periods when the medusa abundance varied less than 10-fold between seasons, there is no relationship between the ratios and the medusa abun dance. This study suggests that the stability of the medusa abundance from season to season could be important in regulating the ecological linkage between diatoms and their predators ¡V copepods.

  5. Medusa structure of the gene regulatory network: dominance of transcription factors in cancer subtype classification.

    Science.gov (United States)

    Guo, Yuchun; Feng, Ying; Trivedi, Niraj S; Huang, Sui

    2011-05-01

    Gene expression profiles consisting of ten thousands of transcripts are used for clustering of tissue, such as tumors, into subtypes, often without considering the underlying reason that the distinct patterns of expression arise because of constraints in the realization of gene expression profiles imposed by the gene regulatory network. The topology of this network has been suggested to consist of a regulatory core of genes represented most prominently by transcription factors (TFs) and microRNAs, that influence the expression of other genes, and of a periphery of 'enslaved' effector genes that are regulated but not regulating. This 'medusa' architecture implies that the core genes are much stronger determinants of the realized gene expression profiles. To test this hypothesis, we examined the clustering of gene expression profiles into known tumor types to quantitatively demonstrate that TFs, and even more pronounced, microRNAs, are much stronger discriminators of tumor type specific gene expression patterns than a same number of randomly selected or metabolic genes. These findings lend support to the hypothesis of a medusa architecture and of the canalizing nature of regulation by microRNAs. They also reveal the degree of freedom for the expression of peripheral genes that are less stringently associated with a tissue type specific global gene expression profile.

  6. First evidence of inbreeding, relatedness and chaotic genetic patchiness in the holoplanktonic jellyfish Pelagia noctiluca (Scyphozoa, Cnidaria).

    Science.gov (United States)

    Aglieri, Giorgio; Papetti, Chiara; Zane, Lorenzo; Milisenda, Giacomo; Boero, Ferdinando; Piraino, Stefano

    2014-01-01

    Genetic drift and non-random mating seldom influence species with large breeding populations and high dispersal potential, characterized by unstructured gene pool and panmixia at a scale lower than the minimum dispersal range of individuals. In the present study, a set of nine microsatellite markers was developed and used to investigate the spatio-temporal genetic patterns of the holoplanktonic jellyfish Pelagia noctiluca (Scyphozoa) in the Southern Tyrrhenian Sea. Homozygote excess was detected at eight loci, and individuals exhibited intra-population relatedness higher than expected by chance in at least three samples. This result was supported by the presence of siblings in at least 5 out 8 samples, 4 of which contained full-sib in addition to half-sib dyads. Having tested and ruled out alternative explanations as null alleles, our results suggest the influence of reproductive and behavioural features in shaping the genetic structure of P. noctiluca, as outcomes of population genetics analyses pointed out. Indeed, the genetic differentiation among populations was globally small but highlighted: a) a spatial genetic patchiness uncorrelated with distance between sampling locations, and b) a significant genetic heterogeneity between samples collected in the same locations in different years. Therefore, despite its extreme dispersal potential, P. noctiluca does not maintain a single homogenous population, but rather these jellyfish appear to have intra-bloom localized recruitment and/or individual cohesiveness, whereby siblings more likely swarm together as a single group and remain close after spawning events. These findings provide the first evidence of family structures and consequent genetic patchiness in a species with highly dispersive potential throughout its whole life cycle, contributing to understanding the patterns of dispersal and connectivity in marine environments.

  7. Towards a Transactional View of Rhetorical and Feminist Theory: Rereading Helen Cixous's "The Laugh of the Medusa."

    Science.gov (United States)

    Biesecker, Barbara A.

    1992-01-01

    Argues that by rereading Helene Cixous's "The Laugh of Medusa" as a rhetoric--that is, an essay which posits what can and must be done by women if they are to intervene effectively in the public sphere through written or oral discourse--both rhetorical and feminist theory and criticism are enriched. (SR)

  8. Phylogenetic analysis with multiple markers indicates repeated loss of the adult medusa stage in Campanulariidae (Hydrozoa, Cnidaria).

    Science.gov (United States)

    Govindarajan, Annette F; Boero, Ferdinando; Halanych, Kenneth M

    2006-03-01

    The Campanulariidae is a group of leptomedusan hydroids (Hydrozoa, Cnidaria) that exhibit a diverse array of life cycles ranging from species with a free medusa stage to those with a reduced or absent medusa stage. Perhaps the best-known member of the taxon is Obelia which is often used as a textbook model of hydrozoan life history. However, Obelia medusae have several unique features leading to a hypothesis that Obelia arose, in a saltational fashion, from an ancestor that lacked a medusa, possibly representing an example of a rare evolutionary reversal. To address the evolution of adult sexual stages in Campanulariidae, a molecular phylogenetic approach was employed using two nuclear (18S rDNA and calmodulin) and two mitochondrial (16S rDNA and cytochrome c oxidase subunit I) genes. Prior to the main analysis, we conducted a preliminary analysis of leptomedusan taxa which suggests that Campanulariidae as presently considered needs to be redefined. Campanulariid analyses are consistent with morphological understanding in that three major clades are recovered. However, several recognized genera are not monophyletic calling into question some "diagnostic" features. Furthermore, ancestral states were reconstructed using parsimony, and a sensitivity analysis was conducted to investigate possible evolutionary transitions in life-history stages. The results indicate that life-cycle transitions have occurred multiple times, and that Obelia might be derived from an ancestor with Clytia-like features.

  9. Towards a Transactional View of Rhetorical and Feminist Theory: Rereading Helen Cixous's "The Laugh of the Medusa."

    Science.gov (United States)

    Biesecker, Barbara A.

    1992-01-01

    Argues that by rereading Helene Cixous's "The Laugh of Medusa" as a rhetoric--that is, an essay which posits what can and must be done by women if they are to intervene effectively in the public sphere through written or oral discourse--both rhetorical and feminist theory and criticism are enriched. (SR)

  10. Relationships Between the Medusae Fossae Formation (MFF), Fluvial Channels, and the Dichotomy Boundary Southeast of Nicholson Crater, Mars

    Science.gov (United States)

    Bradley, B. A.; Sakimoto, S. E. H.

    2001-01-01

    We use Mars Global Surveyor's Mars Orbiter Laser Altimeter (MOLA) and Mars Orbiter Camera (MOC) data to investigate the Medusae Fossae Formation (MFF) and its relationship to fluvial channels southeast of Nicholson Crater. In this area the MFF shows small-scale layering and is draped over Labou Vallis. Additional information is contained in the original extended abstract.

  11. The hydroid and medusa of Sarsia bella sp. nov. (Hydrozoa, Anthoathecatae, Corynidae, with a correction of the life cycle of Polyorchis penicillatus (Eschscholtz

    Directory of Open Access Journals (Sweden)

    Anita Brinckmann-Voss

    2000-12-01

    Full Text Available A new hydrozoan, Sarsia bella sp. nov. is described in both its hydroid and medusa stage from north of Puget Sound, Washington in the San Juan Islands, USA and off the southernmost tip of Vancouver Island, Canada. The medusa is distinguished from other Sarsia species by 16 exumbrellar nematocyst patches and in being more transparent or glass like when living than any other known species of the genus. The exumbrellar nematocyst patches become indistinct in mature specimens and in those crowded in culture, with single nematocysts increasingly spaced out. The hydroid, both field-collected and raised in culture from its medusa, forms small, upright stolonal colonies not more than 1.5 mm high. The hydranths bear an oral whorl of four to five capitate tentacles, and immediately below a second whorl of slightly shorter capitate tentacles. In thriving colonies there is occasionally a whorl of small filiform tentacles on the lower part of the hydranth. Medusa buds develop in the middle of hydranth below the capitate tentacles and above the reduced filiform tentacles, if present. Young medusae are liberated with the typical 16 exumbrellar nematocyst patches. The hydroid of this species was originally mistaken for the hydroid of Polyorchis penicillatus. Brinckmann-Voss (1977 reported a small corynid hydroid living on the margin of rock scallop shells. Medusae liberated from this hydroid were at that time believed to be those of Polyorchis penicillatus (Eschscholtz present in the plankton. Immature medusae of these two species appear strikingly similar, especially with regard to their exumbrellar nematocyst patches, four tentacles and abaxial ocelli. Since then however, this connection has been proven wrong, because an identical hydroid was raised from the medusae of the new species Sarsia bella. Second generation medusae raised in the laboratory were carefully compared with medusae liberated from field collected hydroids (thought to have been Polyorchis

  12. First report of a peroxiredoxin homologue in jellyfish: molecular cloning, expression and functional characterization of CcPrx4 from Cyanea capillata.

    Science.gov (United States)

    Ruan, Zengliang; Liu, Guoyan; Wang, Beilei; Zhou, Yonghong; Lu, Jia; Wang, Qianqian; Zhao, Jie; Zhang, Liming

    2014-01-09

    We first identified and characterized a novel peroxiredoxin (Prx), designated as CcPrx4, from the cDNA library of the tentacle of the jellyfish Cyanea capillata. The full-length cDNA sequence of CcPrx4 consisted of 884 nucleotides with an open reading frame encoding a mature protein of 247 amino acids. It showed a significant homology to peroxiredoxin 4 (Prx4) with the highly conserved F-motif (93FTFVCPTEI101), hydrophobic region (217VCPAGW222), 140GGLG143 and 239YF240, indicating that it should be a new member of the Prx4 family. The deduced CcPrx4 protein had a calculated molecular mass of 27.2 kDa and an estimated isoelectric point of 6.3. Quantitative real-time PCR analysis showed that CcPrx4 mRNA could be detected in all the jellyfish tissues analyzed. CcPrx4 protein was cloned into the expression vector, pET-24a, and expressed in Escherichia coli Rosetta (DE3) pLysS. Recombinant CcPrx4 protein was purified by HisTrap High Performance chelating column chromatography and analyzed for its biological function. The results showed that the purified recombinant CcPrx4 protein manifested the ability to reduce hydrogen peroxide and protect supercoiled DNA from oxidative damage, suggesting that CcPrx4 protein may play an important role in protecting jellyfish from oxidative damage.

  13. Mitochondrial dysfunction contributes to the cytotoxicity induced by tentacle extract from the jellyfish Cyanea capillata in rat renal tubular epithelial NRK-52E cells.

    Science.gov (United States)

    Wang, Tao; He, Qian; Xiao, Liang; Wang, Qianqian; Zhang, Bo; Wang, Beilei; Liu, Guoyan; Zheng, Jiemin; Yu, Bentong; Zhang, Liming

    2013-11-01

    Our previous studies have shown that tentacle extract (TE) from the jellyfish Cyanea capillata could induce a delayed jellyfish envenomation syndrome with severe multiple organ dysfunctions, among which renal injury with tubular necrosis seemed to be most serious. So, in this study, we aimed to explore the toxic effect of TE on rat renal tubular epithelial NRK-52E cells. Based on the previous findings that TE could cause oxidative damage in erythrocytes, the effects of TE on cell oxidative stress conditions, including ROS production and lipid peroxidation, and mitochondrial dysfunction associated with cell death were investigated in NRK-52E cells. The results showed that TE caused cell morphological change and decreased cell viability through induction of apoptosis and necrosis in NRK-52E cells. Meanwhile, ROS overproduction and mitochondrial membrane potential decrease were found before the cell death occurred. It was concluded that TE could induce cytotoxicity, especially apoptosis and necrosis, in NRK-52E cells, and mitochondrial dysfunction and ROS overproduction might play important roles in the process of cell injury and death.

  14. First Report of a Peroxiredoxin Homologue in Jellyfish: Molecular Cloning, Expression and Functional Characterization of CcPrx4 from Cyanea capillata

    Directory of Open Access Journals (Sweden)

    Zengliang Ruan

    2014-01-01

    Full Text Available We first identified and characterized a novel peroxiredoxin (Prx, designated as CcPrx4, from the cDNA library of the tentacle of the jellyfish Cyanea capillata. The full-length cDNA sequence of CcPrx4 consisted of 884 nucleotides with an open reading frame encoding a mature protein of 247 amino acids. It showed a significant homology to peroxiredoxin 4 (Prx4 with the highly conserved F-motif (93FTFVCPTEI101, hydrophobic region (217VCPAGW222, 140GGLG143 and 239YF240, indicating that it should be a new member of the Prx4 family. The deduced CcPrx4 protein had a calculated molecular mass of 27.2 kDa and an estimated isoelectric point of 6.3. Quantitative real-time PCR analysis showed that CcPrx4 mRNA could be detected in all the jellyfish tissues analyzed. CcPrx4 protein was cloned into the expression vector, pET-24a, and expressed in Escherichia coli Rosetta (DE3 pLysS. Recombinant CcPrx4 protein was purified by HisTrap High Performance chelating column chromatography and analyzed for its biological function. The results showed that the purified recombinant CcPrx4 protein manifested the ability to reduce hydrogen peroxide and protect supercoiled DNA from oxidative damage, suggesting that CcPrx4 protein may play an important role in protecting jellyfish from oxidative damage.

  15. Picadura de medusa Olindias sambaquiensis: Análisis de 49 casos

    Directory of Open Access Journals (Sweden)

    Juan H Mosovich

    2012-10-01

    Full Text Available La picadura de la medusa o agua viva Olindia sambaquiensis es de ocurrencia frecuente en las playas de la costa de la provincia de Buenos Aires. Se notifican entre quinientas y mil picaduras de medusas por temporada en la localidad balnearia de Monte Hermoso, al sur de la provincia de Buenos Aires. El daño cutáneo que provoca por su elevada acción urticante plantea un serio inconveniente para el desarrollo del turismo. Durante el mes de enero de 1998, en la localidad de Monte Hermoso se reunieron un total de 49 casos que fueron examinados dentro de la hora posterior a la picadura. Veintiocho eran de sexo masculino (57.1%. La edad promedio fue de 16 ± 4.1 (rango 5-80. El 54% presentó lesiones eritemato-edematosas de configuración lineal, el 28% presentó lesiones predominantemente eritematosas y el 18% presentó placas eritemato-edematosas. En el 73% de los casos las lesiones se localizaron en miembros inferiores. Hemos redefinido la lesión cutánea producida por la medusa O. sambaquiensis, su evolución, sus dimensiones y localizaciones más frecuentes. Además, se ha tipificado y cuantificado el dolor que produce, y otros signos y síntomas que acompañan a la picadura en la hora posterior, a las primeras 24 horas y a los 30 días. Describimos las conductas terapéuticas utilizadas en nuestra costa, evaluamos la efectividad de algunas de ellas en el control del dolor y finalmente proponemos un esquema terapéutico para dicha picadura.Olindias sambaquiensis jellyfish sting occurs frequently in Buenos Aires province coast beaches. Among five hundred and one thousand stings by jellyfish are reported each season at Monte Hermoso, a beach village in the South of Buenos Aires province. The skin damage provoked because of its highly irritant effect poses a serious issue related to tourism development. A total number of 49 cases that were examined during the first hour after the sting were enrolled in Monte Hermoso during January 1998. Twenty

  16. Fine structure, histochemistry, and morphogenesis during excystment of the podocysts of the giant jellyfish Nemopilema nomurai (Scyphozoa, Rhizostomeae).

    Science.gov (United States)

    Ikeda, Hideki; Ohtsu, Kohzoh; Uye, Shin-Ichi

    2011-12-01

    Production of podocysts is the exclusive form of asexual reproduction by polyps of the giant jellyfish Nemopilema nomurai, which has been recurrently blooming in the East Asian seas in the last decade. Podocycts consist of a dome-shaped chitinous capsule with laminated structure that encapsulates a mass of cyst cells filled with granules containing nutrient reserves such as proteins, carbohydrates, and lipids. Mitochondria, rough endoplasmic reticulum, and Golgi complexes are scarce in the cytoplasm of these cells, and the staining reaction for RNA is weak, indicating very low metabolic activity. Podocysts are capable of dormancy for at least 5 years without significant change of internal structure or nutrient reserves. Integrated information about spontaneous and artificially induced metamorphosis suggests that the following processes occur during excystment: (1) nematocyst formation in the internal cell mass, (2) stratification of the cell mass into endoderm and ectoderm, (3) extrusion of the cell mass through a gradual opening of the capsule, (4) formation of primordial polyp mouth and tentacles, and (5) metamorphosis to a polyp. We morphologically confirmed that N. nomurai podocysts have the capacity for long-term dormancy, an ability that should contribute to the periodic nature of the massive blooms of medusae of this species.

  17. Fecundidad de la medusa Stomolophus meleagris (Rhizostomeae: Stomolophidae en el Golfo de California

    Directory of Open Access Journals (Sweden)

    Liliana Carvalho Saucedo

    2012-12-01

    Full Text Available La medusa Stomolophus meleagris es considerada un recurso pesquero de alto valor comercial. Debido a la relevancia de conocer aspectos de importancia biológica actualmente desconocidos, el presente trabajo analiza la fecundidad con base en la estimación del número de ovocitos vitelogénicos en la gónada; su relación con la longitud, diámetro y peso húmedo; y la relación del índice gonadosomático (IGS con su diámetro y longitud. De enero a mayo 2006 se recolectaron 30 ejemplares mensuales que fueron medidos y pesados, de los cuales se analizaron 60 hembras maduras para calcular el volumen de sus gónadas. Se extrajeron las gónadas, se tiñeron con hematoxilina-eosina y se seleccionaron las hembras con madurez gonadal. Mediante la digitalización de imágenes se estimó el número de ovocitos vitelogénicos y previtelogénicos. Se emplearon datos de captura en Las Guásimas para el análisis de reclutamiento poblacional, estimado con FISAT II. La fecundidad se incrementó con la longitud, el diámetro y el peso húmedo total. La menor fecundidad se observó en febrero y la mayor en mayo (11 873 071 y 37 528 197 millones de ovocitos vitelogénico por gónada, respectivamente. El IGS se incrementó con la longitud y diámetro de los ejemplares, con su máximo en mayo de 3.7%. Se observó una producción continua de ovocitos previtelogénicos en todo el periodo de recolecta. El máximo reclutamiento se observó en julio y noviembre (37.50% y 28.01% respectivamente. La alta fecundidad encontrada en S. meleagris sugiere un alto potencial reproductivo para la población y sustenta la posibilidad de la consolidación de una importante pesquería de esta medusa.

  18. Origin of the Medusae Fossae Formation, Mars: Insights from a synoptic approach

    Science.gov (United States)

    Mandt, Kathleen E.; de Silva, Shanaka L.; Zimbelman, James R.; Crown, David A.

    2008-12-01

    The geologic origin of the Medusae Fossae Formation (MFF) has remained a mystery despite three decades of research. To better constrain its formation, an in-depth analysis of observations made in the literature was combined with a new survey of over 700 Mars Orbiter Camera narrow-angle images of the MFF to identify morphologic characteristics and material properties that define this formation as a whole. While previous work has identified clear agreement on some characteristics, our analysis identifies yardangs, collapse features, and layering as pervasive features of the MFF. Whereas collapse features and layering may implicate several different physical and chemical processes, yardangs provide vital information on material properties that inform about mechanical properties of the MFF lithology. Aspect ratios of megayardangs range from 3:1 to 50:1, and slope analyses reveal heights of up to 200 m with cliffs that are almost vertical. Other yardangs show lower aspect ratios and topographic profiles. These characteristics coupled to the presence of serrated margins, suggest that MFF lithology must be of weakly to heavily indurated material that lends itself to jointing. The characteristics and properties of the MFF are inconsistent with those of terrestrial pyroclastic fall deposits or loess, but are in common with large terrestrial ignimbrites, a hypothesis that explains all key observations with a single mechanism. Yardang fields developed in regionally extensive ignimbrite sheets in the central Andes display morphologic characteristics that correlate with degree of induration of the host lithology and suggest an origin by pyroclastic flow for the MFF.

  19. Clearance rates of ephyrae and small medusae of the common jellyfish Aurelia aurita offered different types of prey

    Science.gov (United States)

    Riisgård, Hans Ulrik; Madsen, Caroline V.

    2011-01-01

    Prey selection and knowledge of the amounts of water processed by the early stages of the common jellyfish Aurelia aurita may at certain times of the year be crucial for understanding the plankton dynamics in marine ecosystems with mass occurrences of this jellyfish. In the present study we used two different methods ("clearance method" and "ingestion-rate method") to estimate the amount of water cleared per unit of time of different types and sizes of prey organisms offered to A. aurita ephyrae and small medusae. The mean clearance rates of medusae, estimated with Artemia sp. nauplii as prey by both methods, agreed well, namely 3.8 ± 1.4 l h - 1 by the clearance method and 3.2 ± 1.1 l h - 1 by the ingestion-rate method. Both methods showed that copepods (nauplii and adults) and mussel veligers are captured with considerably lower efficiency, 22 to 37% and 14 to 30%, respectively, than Artemia salina nauplii. By contrast, the water processing rates of ephyrae measured by the clearance method with A. salina nauplii as prey were 3 to 5 times lower than those measured by the ingestion-rate method. This indicates that the prerequisite of full mixing for using the clearance method may not have been fulfilled in the ephyrae experiments. The study demonstrates that the predation impact of the young stages of A. aurita is strongly dependent on its developmental stage (ephyra versus medusa), and the types and sizes of prey organisms. The estimated prey-digestion time of 1.3 h in a steady-state feeding experiment with constant prey concentration supports the reliability of the ingestion-rate method, which eliminates the negative "container effects" of the clearance method, and it seems to be useful in future jellyfish studies, especially on small species/younger stages in which both type and number of prey can be easily and precisely assessed.

  20. [Medusae (Cnidaria: Hydrozoa) from a coastal upwelling zone, Culebra Bay, Pacific, Costa Rica].

    Science.gov (United States)

    Rodríguez-Sáenz, Karina; Vargas-Zamora, José A; Segura-Puertas, Lourdes

    2012-12-01

    The hydromedusae have an important role in marine trophic webs due to their predatory feeding habits. This is the first study of this group of gelatinous marine zooplankton in a coastal upwelling area of Central America. The composition and abundance variability of hydromedusae were studied during six months in 1999 at four stations in Culebra Bay, Gulf of Papagayo, Pacific coast of Costa Rica (10 degrees 37' N-85 degrees 40' W). A total of 53 species were identified, of which 26 are new records for Costa Rica, 21 are new records for Central America, and eight are new records for the Eastern Tropical Pacific. The more abundant species (more than 30% of the total abundance) were Liriope tetraphylla, Solmundella bitentaculata and Aglaura hemistoma. Six species occurred throughout the sampling period, 10 were present only during the dry season (December-April), and 17 were so during the rainy season (May-November). Significant differences of medusan abundances were found between seasons (dry vs. rainy). Maximum abundance (2.1 +/- 4.3ind./m3) was recorded when upwelled deeper water influenced the Bay, as indicated by local higher oxygen concentrations and lower water temperatures. The relatively high species richness of medusae found in Culebra Bay is probably related to factors like the pristine condition of the Bay, the arrival of oceanic species transported by the Equatorial Counter Current (ECC), the eastward shoaling of the Costa Rica Dome, and local currents. Illustrations of the 15 more important species are included to facilitate their identification and foster future work in the region.

  1. A new species of Pseudomacrochiron Reddiah, 1969 (Crustacea: Copepoda: Macrochironidae) associated with scyphistomae of the moon jellyfish Aurelia sp. (Cnidaria: Scyphozoa) off Japan.

    Science.gov (United States)

    Tang, Danny; Yasuda, Akira; Yamada, Satoshi; Nagasawa, Kazuya

    2012-02-01

    A new species of the Macrochironidae Humes & Boxshall, 1996 (Copepoda: Cyclopoida), Pseudomacrochiron aureliae n. sp., is described based on adult specimens extracted from the gastrovacular cavity of the scyphistomae of Aurelia sp. (Cnidaria: Scyphozoa) collected in the Seto Inland Sea and Ise Bay off the coast of Japan. The new species differs from its congeners by having the following combination of characters: a caudal ramus with a length to width ratio of 3.1; an accessory flagellum on caudal setae II, III and VI; three apical setae on the maxillule; only setae I and II on the maxillary basis; two short spines on the female maxilliped claw (endopod); an armature of III, I, 4 on the terminal exopodal segment of leg 3; an armature of I, II, 2 on the terminal endopodal segment of leg 3; an armature of II, I, 4 on the terminal exopodal segment of leg 4; and a short free exopodal segment of leg 5 (length to width ratio of 1.4) armed with a long seta and short spine. P. aureliae n. sp. is the first member of the genus reported from off Japan and from the scyphistomae of its scyphozoan host.

  2. Mitochondrial genome of the moon jelly Aurelia aurita (Cnidaria, Scyphozoa): A linear DNA molecule encoding a putative DNA-dependent DNA polymerase.

    Science.gov (United States)

    Shao, Zhiyong; Graf, Shannon; Chaga, Oleg Y; Lavrov, Dennis V

    2006-10-15

    The 16,937-nuceotide sequence of the linear mitochondrial DNA (mt-DNA) molecule of the moon jelly Aurelia aurita (Cnidaria, Scyphozoa) - the first mtDNA sequence from the class Scypozoa and the first sequence of a linear mtDNA from Metazoa - has been determined. This sequence contains genes for 13 energy pathway proteins, small and large subunit rRNAs, and methionine and tryptophan tRNAs. In addition, two open reading frames of 324 and 969 base pairs in length have been found. The deduced amino-acid sequence of one of them, ORF969, displays extensive sequence similarity with the polymerase [but not the exonuclease] domain of family B DNA polymerases, and this ORF has been tentatively identified as dnab. This is the first report of dnab in animal mtDNA. The genes in A. aurita mtDNA are arranged in two clusters with opposite transcriptional polarities; transcription proceeding toward the ends of the molecule. The determined sequences at the ends of the molecule are nearly identical but inverted and lack any obvious potential secondary structures or telomere-like repeat elements. The acquisition of mitochondrial genomic data for the second class of Cnidaria allows us to reconstruct characteristic features of mitochondrial evolution in this animal phylum.

  3. Impact assessment of non-indigenous jellyfish species on the estuarine community dynamic: A model of medusa phase

    Science.gov (United States)

    Muha, Teja Petra; Teodósio, Maria Alexandra; Ben-Hamadou, Radhouan

    2017-03-01

    Non-indigenous jellyfish species (NIJS) Blackforida virginica have recently been introduced to the Guadiana Estuary. A modelling approach was used for the assessment of the species-specific impact on the native community, during the medusa phase. The novel interactions between NIJS and the native community are assessed through biomass variation including hydrodynamic and climatic variables. Sensitivity analysis shows that both native species, as well as NIJS highly depend on the water discharge regime, nutrient contribution and the amount of detritus production. Abiotic factors such as the Northern Atlantic Oscillation, water discharge, nutrient load and detritus production are the most influential factors for the dynamics of the estuarine ecosystem demonstrated by the model. Low water discharge and low nutrient retention rate appear to be the most favourable conditions for B. virginica. The species is a non-selective predator able to integrate into the system effectively and has caused a decrease in the biomass of other organisms in the estuarine ecosystem throughout the summer after dam removal. The B. virginica significant impact can be evaluated only when the jellyfish detritus food pathway is involved. The B. virginica predatory impact potential, as well as food preference, appears to be the most influential factors for the overall biomass variation. On the contrary, winter freshwater pulses reduce the survival rate of jellyfish polyps which results in a decrease of medusa during summer. The model presents a strong ecohydrology movement where the fluctuation of organism biomass strongly depends on the hydrological conditions including the amount of nutrient load.

  4. La mirada desmitificadora de la Gorgona de Prohaska. "Medusa" de Ricardo Menéndez Salmón

    OpenAIRE

    Calvo Revilla, Ana

    2016-01-01

    Analizamos la reescritura del mito de Medusa, el monstruo de mirada letal que transformaba en piedra a quien le miraba a los ojos, que emprende Ricardo Menéndez Salmón en esta novela homónima, que aúna la lucidez el ensayo y la belleza del poeta (Seix Barral, 2012). Desentrañamos la reescritura del mito clásico a través de la representación iconográfica de la maldad, el horror y la sevicia que vertebran el siglo XX y emprendemos la reflexión filosófica sobre la atrocidad que despierta el mons...

  5. MEDUSA-2.0: an intermediate complexity biogeochemical model of the marine carbon cycle for climate change and ocean acidification studies

    Science.gov (United States)

    Yool, A.; Popova, E. E.; Anderson, T. R.

    2013-10-01

    MEDUSA-1.0 (Model of Ecosystem Dynamics, nutrient Utilisation, Sequestration and Acidification) was developed as an "intermediate complexity" plankton ecosystem model to study the biogeochemical response, and especially that of the so-called "biological pump", to anthropogenically driven change in the World Ocean (Yool et al., 2011). The base currency in this model was nitrogen from which fluxes of organic carbon, including export to the deep ocean, were calculated by invoking fixed C:N ratios in phytoplankton, zooplankton and detritus. However, due to anthropogenic activity, the atmospheric concentration of carbon dioxide (CO2) has significantly increased above its natural, inter-glacial background. As such, simulating and predicting the carbon cycle in the ocean in its entirety, including ventilation of CO2 with the atmosphere and the resulting impact of ocean acidification on marine ecosystems, requires that both organic and inorganic carbon be afforded a more complete representation in the model specification. Here, we introduce MEDUSA-2.0, an expanded successor model which includes additional state variables for dissolved inorganic carbon, alkalinity, dissolved oxygen and detritus carbon (permitting variable C:N in exported organic matter), as well as a simple benthic formulation and extended parameterizations of phytoplankton growth, calcification and detritus remineralisation. A full description of MEDUSA-2.0, including its additional functionality, is provided and a multi-decadal spin-up simulation (1860-2005) is performed. The biogeochemical performance of the model is evaluated using a diverse range of observational data, and MEDUSA-2.0 is assessed relative to comparable models using output from the Coupled Model Intercomparison Project (CMIP5).

  6. MEDUSA-2.0: an intermediate complexity biogeochemical model of the marine carbon cycle for climate change and ocean acidification studies

    Directory of Open Access Journals (Sweden)

    A. Yool

    2013-10-01

    Full Text Available MEDUSA-1.0 (Model of Ecosystem Dynamics, nutrient Utilisation, Sequestration and Acidification was developed as an "intermediate complexity" plankton ecosystem model to study the biogeochemical response, and especially that of the so-called "biological pump", to anthropogenically driven change in the World Ocean (Yool et al., 2011. The base currency in this model was nitrogen from which fluxes of organic carbon, including export to the deep ocean, were calculated by invoking fixed C:N ratios in phytoplankton, zooplankton and detritus. However, due to anthropogenic activity, the atmospheric concentration of carbon dioxide (CO2 has significantly increased above its natural, inter-glacial background. As such, simulating and predicting the carbon cycle in the ocean in its entirety, including ventilation of CO2 with the atmosphere and the resulting impact of ocean acidification on marine ecosystems, requires that both organic and inorganic carbon be afforded a more complete representation in the model specification. Here, we introduce MEDUSA-2.0, an expanded successor model which includes additional state variables for dissolved inorganic carbon, alkalinity, dissolved oxygen and detritus carbon (permitting variable C:N in exported organic matter, as well as a simple benthic formulation and extended parameterizations of phytoplankton growth, calcification and detritus remineralisation. A full description of MEDUSA-2.0, including its additional functionality, is provided and a multi-decadal spin-up simulation (1860–2005 is performed. The biogeochemical performance of the model is evaluated using a diverse range of observational data, and MEDUSA-2.0 is assessed relative to comparable models using output from the Coupled Model Intercomparison Project (CMIP5.

  7. MEDUSA-2.0: an intermediate complexity biogeochemical model of the marine carbon cycle for climate change and ocean acidification studies

    Directory of Open Access Journals (Sweden)

    A. Yool

    2013-02-01

    Full Text Available MEDUSA-1.0 (Model of Ecosystem Dynamics, nutrient Utilisation, Sequestration and Acidification was developed as an "intermediate complexity" plankton ecosystem model to study the biogeochemical response, and especially that of the so-called "biological pump", to anthropogenically-driven change in the World Ocean (Yool et al., 2011. The base currency in this model was nitrogen from which fluxes of organic carbon, including export to the deep ocean, were calculated by invoking fixed C:N ratios in phytoplankton, zooplankton and detritus. Since the beginning of the industrial era, the atmospheric concentration of carbon dioxide (CO2 has significantly increased above its natural, inter-glacial background concentration. Simulating and predicting the carbon cycle in the ocean in its entirety, including ventilation of CO2 with the atmosphere and the resulting impact of ocean acidification on marine ecosystems, therefore requires that both organic and inorganic carbon be afforded a full representation in the model specification. Here, we introduce MEDUSA-2.0, an expanded successor model which includes additional state variables for dissolved inorganic carbon, alkalinity, dissolved oxygen and detritus carbon (permitting variable C:N in exported organic matter, as well as a simple benthic formulation and extended parameterisations of phytoplankton growth, calcification and detritus remineralisation. A full description of MEDUSA-2.0, including its additional functionality, is provided and a multi-decadal hindcast simulation described (1860–2005, to evaluate the biogeochemical performance of the model.

  8. Polygonal ridge networks on Mars: Diversity of morphologies and the special case of the Eastern Medusae Fossae Formation

    Science.gov (United States)

    Kerber, Laura; Dickson, James L.; Head, James W.; Grosfils, Eric B.

    2017-01-01

    Polygonal ridge networks, also known as boxwork or reticulate ridges, are found in numerous locations and geological contexts across Mars. Distinguishing the morphologies and geological context of the ridge networks sheds light on their potential as astrobiological and mineral resource sites of interest. The most widespread type of ridge morphology is characteristic of the Nili Fossae and Nilosyrtis region and consists of thin, criss-crossing ridges with a variety of heights, widths, and intersection angles. They are found in ancient Noachian terrains at a variety of altitudes (between -2500 and 2200 m) and geographic locations and are likely to be chemically altered fracture planes or mineral veins. They occur in the same general areas as valley networks and ancient lake basins, but they are not more numerous where these water-related features are concentrated, and can appear in places where th morphologies are absent. Similarly, some of the ridge networks are located near hydrated mineral detections, but there is not a one-to-one correlation. Smaller, light-toned ridges of variable widths have been found in Gale Crater and other rover sites and are interpreted to be smaller versions of the Nili-like ridges, mostly formed by the mineralization of fractures. This type of ridge is likely to be found in many other places on Mars as more high-resolution data become available. Sinus Meridiani contains many flat-topped ridges arranged into quasi-circular patterns. The ridges are eroding from a clay-rich unit, and could be formed by a similar process as the Nili-type ridges, but at a much larger scale and controlled by fractures made through a different process. Hellas Basin is host to a fourth type of ridge morphology consisting of large, thick, light-toned ridges forming regular polygons at several superimposed scales. While still enigmatic, these are most likely to be the result of sediment-filled fractures. The Eastern Medusae Fossae Formation contains large swaths

  9. Interannual variability, growth, reproduction and feeding of Pelagia noctiluca (Cnidaria: Scyphozoa) in the Straits of Messina (Central Mediterranean Sea): Linkages with temperature and diet

    Science.gov (United States)

    Rosa, S.; Pansera, M.; Granata, A.; Guglielmo, L.

    2013-02-01

    To identify some of the possible environmental factors stimulating the increasingly frequent outbreaks of the scyphomedusa Pelagia noctiluca in the Straits of Messina, we investigated its abundance, growth, reproduction and feeding over a 4-year period, from 2007 to 2011, at two coastal sites. Using either field investigations and manipulative experiments we show that, among the various factors considered, shifts in water temperature (influencing medusae metabolism, growth and reproduction rates) and the size structure of the zooplankton community (their natural preys) can promote the proliferation of P. noctiluca. In particular, we show that increased temperature let jellyfishes to grow more rapidly and reach exceptional sizes. We also report a peculiar opportunistic behavior of P. noctiluca, which makes this species a potentially strong competitor in the pelagic trophic web of the Straits ecosystem. We therefore propose that more frequent P. noctiluca outbreaks stimulated by increasing sea surface temperature and shifts in their prey availability and composition would become, in the near future, a major cause of ecosystem shift.

  10. Jellyfish as prey: frequency of predation and selective foraging of Boops boops (Vertebrata, Actinopterygii on the mauve stinger Pelagia noctiluca (Cnidaria, Scyphozoa.

    Directory of Open Access Journals (Sweden)

    Giacomo Milisenda

    Full Text Available In recent years, jellyfish blooms have attracted considerable scientific interest for their potential impacts on human activities and ecosystem functioning, with much attention paid to jellyfish as predators and to gelatinous biomass as a carbon sink. Other than qualitative data and observations, few studies have quantified direct predation of fish on jellyfish to clarify whether they may represent a seasonally abundant food source. Here we estimate predation frequency by the commercially valuable Mediterranean bogue, Boops boops on the mauve stinger jellyfish, Pelagia noctiluca, in the Strait of Messina (NE Sicily. A total of 1054 jellyfish were sampled throughout one year to quantify predation by B. boops from bite marks on partially eaten jellyfish and energy density of the jellyfish. Predation by B. boops in summer was almost twice that in winter, and they selectively fed according to medusa gender and body part. Calorimetric analysis and biochemical composition showed that female jellyfish gonads had significantly higher energy content than male gonads due to more lipids and that gonads had six-fold higher energy content than the somatic tissues due to higher lipid and protein concentrations. Energetically, jellyfish gonads represent a highly rewarding food source, largely available to B. boops throughout spring and summer. During the remainder of the year, when gonads were not very evident, fish predation switched towards less-selective foraging on the somatic gelatinous biomass. P. noctiluca, the most abundant jellyfish species in the Mediterranean Sea and a key planktonic predator, may represent not only a nuisance for human leisure activities and a source of mortality for fish eggs and larvae, but also an important resource for fish species of commercial value, such as B. boops.

  11. Jellyfish as Prey: Frequency of Predation and Selective Foraging of Boops boops (Vertebrata, Actinopterygii) on the Mauve Stinger Pelagia noctiluca (Cnidaria, Scyphozoa)

    Science.gov (United States)

    Fuentes, Veronica L.; Boero, Ferdinando; Guglielmo, Letterio; Purcell, Jennifer E.; Piraino, Stefano

    2014-01-01

    In recent years, jellyfish blooms have attracted considerable scientific interest for their potential impacts on human activities and ecosystem functioning, with much attention paid to jellyfish as predators and to gelatinous biomass as a carbon sink. Other than qualitative data and observations, few studies have quantified direct predation of fish on jellyfish to clarify whether they may represent a seasonally abundant food source. Here we estimate predation frequency by the commercially valuable Mediterranean bogue, Boops boops on the mauve stinger jellyfish, Pelagia noctiluca, in the Strait of Messina (NE Sicily). A total of 1054 jellyfish were sampled throughout one year to quantify predation by B. boops from bite marks on partially eaten jellyfish and energy density of the jellyfish. Predation by B. boops in summer was almost twice that in winter, and they selectively fed according to medusa gender and body part. Calorimetric analysis and biochemical composition showed that female jellyfish gonads had significantly higher energy content than male gonads due to more lipids and that gonads had six-fold higher energy content than the somatic tissues due to higher lipid and protein concentrations. Energetically, jellyfish gonads represent a highly rewarding food source, largely available to B. boops throughout spring and summer. During the remainder of the year, when gonads were not very evident, fish predation switched towards less-selective foraging on the somatic gelatinous biomass. P. noctiluca, the most abundant jellyfish species in the Mediterranean Sea and a key planktonic predator, may represent not only a nuisance for human leisure activities and a source of mortality for fish eggs and larvae, but also an important resource for fish species of commercial value, such as B. boops. PMID:24727977

  12. Jellyfish as prey: frequency of predation and selective foraging of Boops boops (Vertebrata, Actinopterygii) on the mauve stinger Pelagia noctiluca (Cnidaria, Scyphozoa).

    Science.gov (United States)

    Milisenda, Giacomo; Rosa, Sara; Fuentes, Veronica L; Boero, Ferdinando; Guglielmo, Letterio; Purcell, Jennifer E; Piraino, Stefano

    2014-01-01

    In recent years, jellyfish blooms have attracted considerable scientific interest for their potential impacts on human activities and ecosystem functioning, with much attention paid to jellyfish as predators and to gelatinous biomass as a carbon sink. Other than qualitative data and observations, few studies have quantified direct predation of fish on jellyfish to clarify whether they may represent a seasonally abundant food source. Here we estimate predation frequency by the commercially valuable Mediterranean bogue, Boops boops on the mauve stinger jellyfish, Pelagia noctiluca, in the Strait of Messina (NE Sicily). A total of 1054 jellyfish were sampled throughout one year to quantify predation by B. boops from bite marks on partially eaten jellyfish and energy density of the jellyfish. Predation by B. boops in summer was almost twice that in winter, and they selectively fed according to medusa gender and body part. Calorimetric analysis and biochemical composition showed that female jellyfish gonads had significantly higher energy content than male gonads due to more lipids and that gonads had six-fold higher energy content than the somatic tissues due to higher lipid and protein concentrations. Energetically, jellyfish gonads represent a highly rewarding food source, largely available to B. boops throughout spring and summer. During the remainder of the year, when gonads were not very evident, fish predation switched towards less-selective foraging on the somatic gelatinous biomass. P. noctiluca, the most abundant jellyfish species in the Mediterranean Sea and a key planktonic predator, may represent not only a nuisance for human leisure activities and a source of mortality for fish eggs and larvae, but also an important resource for fish species of commercial value, such as B. boops.

  13. Seasonal occurrence of Opechona pyriforme metacercariae (Digenea: Lepocreadiidae) in Eirene tenuis medusae (Hydrozoa: Leptothecata) from a hypersaline lagoon in western Gulf of Mexico.

    Science.gov (United States)

    Martell-Hernández, Luis Felipe; Ocaña-Luna, Alberto; Sánchez-Ramírez, Marina

    2011-02-01

    Seasonal occurrence of Opechona pyriforme metacercariae in the Eirene tenuis population from Laguna Madre, Mexico was analyzed in zooplankton samples collected in October 1997 and January, May, and July 1998. Eirene tenuis medusae were present in May, July, and October, although parasites were found only in October and July samples. Host population density was positively correlated with both surface water temperature and salinity. Total sample prevalence was 3.74%, mean abundance of the parasite was 0.06, and intensity of infection ranged between 1 and 59 metacercariae/host. Prevalence differed significantly among seasons, while intensity of infection did not. Parasite distribution was found to be highly aggregated. Although O. pyriforme infected hydromedusae of all sizes, prevalence was higher in sizes above 2.11 mm umbrella diameter. Additionally, a tendency towards increasing intensity of infection values with increasing umbrella diameter of medusae was observed. This is the first record of E. tenuis as a second intermediate host of O. pyriforme, as well as the first record of this helminth in the Gulf of Mexico.

  14. First record of the invasive medusa Blackfordia virginica (Hydrozoa: Leptomedusae in the Río de la Plata estuary, Argentina-Uruguay Primer registro de la medusa invasora Blackfordia virginica (Hydrozoa: Leptomedusae en el estuario del Río de la Plata, Argentina-Uruguay

    Directory of Open Access Journals (Sweden)

    GABRIEL GENZANO

    2006-06-01

    Full Text Available Blackfordia virginica is a well-known invasive medusa inhabiting estuarine areas. It was recently detected in northern Argentina, constituting the first record of invasive hydromedusa for the Argentine Sea. In this work more than 1,500 plankton samples in the southwestern Atlantic Ocean (34-55º S from 1983 to 2000 were analyzed. More than 5,000 specimens per sample of B. virginica were found in Río de la Plata estuary for the first time in February 2000. This river is one of the large waterways of South America with an intense nautical traffic and several exotic species has been recorded here, mainly due to trans-oceanic shipping traffic. It is important to point out that we found medusae of both sexes (therefore this species could be introduced in either the medusa or the polyp stages or both, different size classes (including very small juveniles and maturation stages, and in such high numbers that would suggest local reproduction. For this reason the recent finding of this hydromedusa could represent the starting point of an successful introductionBlackfordia virginica es una medusa invasora reconocida por habitar áreas estuariales. Recientemente fue descubierta en el norte de Argentina, constituyendo el primer registro de una hidromedusa invasora para el mar argentino. En este trabajo se analizaron más de 1.500 muestras de plancton en el Océano Atlántico sudoccidental (34-55º S desde 1983 hasta el año 2000. Más de 5.000 especímenes por muestra fueron encontrados por primera vez en el estuario del Río de la Plata durante febrero del año 2000. Este río es una de las mayores vías de agua de América del Sur, posee un intenso tráfico náutico y varias especies exóticas se han registrado allí, principalmente debido al tráfico marítimo transoceánico. Es importante señalar que se encontraron medusas de ambos sexos (por lo tanto esta especie podría haber sido introducida en su estadio medusa, pólipo o ambos, con diferentes

  15. Medusas (Cnidaria: Hydrozoa de una zona de afloramiento costero, Bahía Culebra, Pacífico, Costa Rica Medusae (Cnidaria: Hydrozoa from a coastal upwelling zone, Culebra Bay, Pacific, Costa Rica

    Directory of Open Access Journals (Sweden)

    Karina Rodríguez-Sáenz

    2012-12-01

    Culebra Bay, Gulf of Papagayo, Pacific coast of Costa Rica (10º37’ N-85º40’ W. A total of 53 species were identified, of which 26 are new records for Costa Rica, 21 are new records for Central America, and eight are new records for the Eastern Tropical Pacific. The more abundant species (more than 30% of the total abundance were Liriope tetraphylla, Solmundella bitentaculata and Aglaura hemistoma. Six species occurred throughout the sampling period, 10 were present only during the dry season (December-April, and 17 were so during the rainy season (May-November. Significant differences of medusan abundances were found between seasons (dry vs. rainy. Maximum abundance (2.1±4.3ind./m³ was recorded when upwelled deeper water influenced the Bay, as indicated by local higher oxygen concentrations and lower water temperatures. The relatively high species richness of medusae found in Culebra Bay is probably related to factors like the pristine condition of the Bay, the arrival of oceanic species transported by the Equatorial Counter Current (ECC, the eastward shoaling of the Costa Rica Dome, and local currents. Illustrations of the 15 more important species are included to facilitate their identification and foster future work in the region.

  16. Emulation of the MBM-MEDUSA model: exploring the sea level and the basin-to-shelf transfer influence on the system dynamics

    Science.gov (United States)

    Ermakov, Ilya; Crucifix, Michel; Munhoven, Guy

    2013-04-01

    Complex climate models require high computational burden. However, computational limitations may be avoided by using emulators. In this work we present several approaches for dynamical emulation (also called metamodelling) of the Multi-Box Model (MBM) coupled to the Model of Early Diagenesis in the Upper Sediment A (MEDUSA) that simulates the carbon cycle of the ocean and atmosphere [1]. We consider two experiments performed on the MBM-MEDUSA that explore the Basin-to-Shelf Transfer (BST) dynamics. In both experiments the sea level is varied according to a paleo sea level reconstruction. Such experiments are interesting because the BST is an important cause of the CO2 variation and the dynamics is potentially nonlinear. The output that we are interested in is the variation of the carbon dioxide partial pressure in the atmosphere over the Pleistocene. The first experiment considers that the BST is fixed constant during the simulation. In the second experiment the BST is interactively adjusted according to the sea level, since the sea level is the primary control of the growth and decay of coral reefs and other shelf carbon reservoirs. The main aim of the present contribution is to create a metamodel of the MBM-MEDUSA using the Dynamic Emulation Modelling methodology [2] and compare the results obtained using linear and non-linear methods. The first step in the emulation methodology used in this work is to identify the structure of the metamodel. In order to select an optimal approach for emulation we compare the results of identification obtained by the simple linear and more complex nonlinear models. In order to identify the metamodel in the first experiment the simple linear regression and the least-squares method is sufficient to obtain a 99,9% fit between the temporal outputs of the model and the metamodel. For the second experiment the MBM's output is highly nonlinear. In this case we apply nonlinear models, such as, NARX, Hammerstein model, and an 'ad

  17. Commencement Bay Study. Volume IV. Invertebrates.

    Science.gov (United States)

    1981-12-31

    BAY Taxa Epibenthic Pump Infaunal Core Hydrozoa Hydroida (polyp) + Scyphozoa Scyphozoan medusae + Nemertea + Nematoda + + Turbellaria Polycladida...Occurrence Nemertea 2 0.8 Polychaeta unid. 14 5.9 Armandia brevis 3 1.2 Caitella capitata 6 2.5 Cirratulidae 1 0.4 Eteone longa 1 0.4 Platynereis

  18. Medusivorous fishes, a review

    OpenAIRE

    Ates, R.M.L.

    1988-01-01

    A preliminary review is presented of fish species having consumed pelagic Cnidaria (Scyphozoa and Hydrozoa) as well as Ctenophora. Quantitative data are scarce. Knowledge of morphological and physiological adaptations of fishes foraging on gelatinous plankton is almost non-existent. Many fish species consume medusae and some reasons to suspect that there are even more that do so, are discussed.

  19. 2种方法制备硫酸化小刺猴头菌多糖%Two Methods to Prepare Sulfated Polysaccharides from Hericium caput-medusae

    Institute of Scientific and Technical Information of China (English)

    王新宇; 迟祥; 石亮; 沈思捷; 王雪; 宋慧

    2013-01-01

    采用氯磺酸-吡啶法和浓硫酸法制备硫酸化小刺猴头菌多糖,傅立叶变换红外光谱鉴定硫酸化多糖。结果表明:修饰后的多糖在1259.17 cm -1和807.73 cm -1或1226.44 cm -1处出现硫酸酯键吸收峰,表明硫酸基团已经与多糖结合成酯。采用氯化钡-明胶法测定硫酸根含量,制备取代度为0.94或0.82的硫酸化多糖。%Sulfated Hericium caput-medusae polysaccharides were prepared through wolfrom and sulfuric acid methods and the obtained polysaccharides were characterized by Fourier-transform infrared spectra. The results showed the polysaccharide emerged absorption peak corresponded to sulfate ester at 1 259.17 cm -1and 807.73 cm -1 or 1 226.44 cm -1after modification,indicating the group of sulphuric acid had conjugated ester with polysaccharide.The content of sulphate was determined through barium-chloride gelatin procedures.Sulfated polysaccharides with substitution degrees of 0.94 and 0.82 were prepared.

  20. Summer composition and distribution of the jellyfish (Cnidaria: Medusozoa in the shelf area off the central Mexican Pacific Composición y distribución de las medusas (Cnidaria: Medusozoa en la plataforma continental central del Pacifico mexicano

    Directory of Open Access Journals (Sweden)

    Lourdes Segura-Puertas

    2010-04-01

    Full Text Available The composition, distribution, and abundance of the jellyfish community of a shelf area of the Mexican tropical Pacific were surveyed during August 1988. Zooplankton samples were collected along transects on the outer and inner sectors of the continental shelf to determine the structure of the jellyfish community and its variation in this area during the rainy season. A total of 23 species were recorded, with Aglaura hemistoma, Solmundella bitentaculata, Liriope tetraphylla, Pelagia noctiluca, and Rhopalonema velatum being the most abundant. The total abundance of medusae and of the most abundant species was statistically independent of depth and distance to the coast. Hence, the total jellyfish abundance of the most abundant species, and Shannon's Diversity index had a uniform distribution in both the inner and the outer shelf; furthermore, neritic-oceanic forms and oceanic species occurred indistinctly over the entire continental shelf. On the outer shelf A. hemistoma and S. bitentaculata were most abundant; the former species, together with L. tetraphylla, weakly characterized the inner shelf jellyfish community. The narrowness of the shelf, the wide distribution of the most abundant forms, and the possible effect of local advective processes from the oceanic zone masked a definite gradient across the shelf. Three species have not been recorded previously in the Mexican Pacific: Amphinema dinema (Péron and Lesueur, 1810, Sarsia coccometra Bigelow, 1909, and Clytia mccradyi (Brooks, 1888. The finding of A. dinema is the first in the Eastern Pacific.Se estudió la composición, distribución y abundancia de la comunidad de medusas de la plataforma continental en el Pacífico mexicano durante agosto 1988. Las muestras de zooplancton provienen de transectos en las zonas externa e interna de la plataforma para determinar la estructura de la comunidad de medusas y su variación durante la época de lluvias. Se identificaron 23 especies; las m

  1. Fecundidad de la medusa Stomolophus meleagris (Rhizostomeae: Stomolophidae en el Golfo de California Stomolophus meleagris fecundity (Rhizostomeae: Stomolophidae in the Gulf of California

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    Liliana Carvalho Saucedo

    2012-12-01

    Full Text Available La medusa Stomolophus meleagris es considerada un recurso pesquero de alto valor comercial. Debido a la relevancia de conocer aspectos de importancia biológica actualmente desconocidos, el presente trabajo analiza la fecundidad con base en la estimación del número de ovocitos vitelogénicos en la gónada; su relación con la longitud, diámetro y peso húmedo; y la relación del índice gonadosomático (IGS con su diámetro y longitud. De enero a mayo 2006 se recolectaron 30 ejemplares mensuales que fueron medidos y pesados, de los cuales se analizaron 60 hembras maduras para calcular el volumen de sus gónadas. Se extrajeron las gónadas, se tiñeron con hematoxilina-eosina y se seleccionaron las hembras con madurez gonadal. Mediante la digitalización de imágenes se estimó el número de ovocitos vitelogénicos y previtelogénicos. Se emplearon datos de captura en Las Guásimas para el análisis de reclutamiento poblacional, estimado con FISAT II. La fecundidad se incrementó con la longitud, el diámetro y el peso húmedo total. La menor fecundidad se observó en febrero y la mayor en mayo (11 873 071 y 37 528 197 millones de ovocitos vitelogénico por gónada, respectivamente. El IGS se incrementó con la longitud y diámetro de los ejemplares, con su máximo en mayo de 3.7%. Se observó una producción continua de ovocitos previtelogénicos en todo el periodo de recolecta. El máximo reclutamiento se observó en julio y noviembre (37.50% y 28.01% respectivamente. La alta fecundidad encontrada en S. meleagris sugiere un alto potencial reproductivo para la población y sustenta la posibilidad de la consolidación de una importante pesquería de esta medusa.The cannonball jellyfish Stomolophus meleagris is regarded as a fishery resource with high commercial value, but with scarce biological information. With the aim to generate preliminary information on reproductive aspects, the present study analyzes its fecundity, based on the estimated

  2. 泰国近海习见有毒立方水母和钵水母的遗传分析%Genetic analysis of common venomous Cubozoa and Scyphozoa in Thailand waters

    Institute of Scientific and Technical Information of China (English)

    刘瑞娟; 肖洁; 张学雷; Charatsee Aungtonya

    2016-01-01

    The genetic diversity of common venomous Cubozoa and Scyphozoa jellyfish in the coastal waters of Thai-land was investigated using the nuclear 18S and mitochondrial 16S rDNA genes.It was also compared about the ca-pability of these two molecular markers to discriminate those common jellyfish species.There were 9 genetically distinctive species among the 32 samples collected from Thai waters,including 4 Cubozoa species,4 Scyphozoans and 1 hydrozoan.However,it needs further information on the morphology and life cycle to determine the true taxonomic status of most species in this research.The K2P (Kimura 2-parameter)genetic distance was evaluated within and among the species based on the sequences of these two genes.The results showed much higher genetic divergence based on 16S gene (0-0.050 and 0.204-0.474 for intra-and inter-species genetic distances,respec-tively)compared with those using 18S gene (0-0.002 and 0.008-0.066 for intra-and inter-species genetic dis-tances,respectively).At the same time,the A and T nucleotide composition of 16S gene was obviously higher than 18S gene.And significant variation of nucleotide composition was detected between two jellyfish classes using 16S gene,but not 18S gene.These results further indicated the relatively higher mutation rate of 16S gene,which could be applied for the genetic diversity studies among jellyfish species with close genetic relationship and the in-tra-species genetic population studies.%本研究利用线粒体16S rDNA 和核基因18S rDNA 片段,对泰国沿海常见的有毒水母进行遗传分析,并比较了2个基因片段作为通用分子标记,在研究水母类多个纲的遗传多样性中的应用。研究发现,泰国近海的有毒水母存在较高的遗传多样性,所获得的32个样品可以分为9个种,包括4种钵水母、4种立方水母和1种水螅水母。然而,完全确定各种的分类地位,还需要更多的形态、生活史等方面信息。两个基因片

  3. 水母雪莲细胞培养物调血脂作用的研究%Effects of cell cultures of saussurea medusa in regulating blood lipid of hyperlipidemic rats

    Institute of Scientific and Technical Information of China (English)

    杨波; 李天德; 胡显文; 王劲松; 高丽华; 陈惠鹏

    2004-01-01

    背景:鉴于野生水母雪莲濒临灭绝,军事医学科学院建立了一种人工培养水母雪莲的方法.目的:探讨水母雪莲细胞培养物对高脂大鼠的调血脂作用.设计:完全随机设计,对照实验研究.单位:由解放军总医院心内科和军事医学科学院生物工程研究所合作.材料:实验于2003-03/06在解放军总医院医学实验动物中心完成.实验动物由解放军总医院实验动物中心提供.雄性SD大鼠64只,体质量200~220 g,随机分为4组,每组16只:正常对照组、高脂模型组、高剂量组和低剂量组.干预:正常对照组仅喂基础饲料,高脂模型组喂高脂饲料,高剂量组喂高脂饲料的同时饲以水母雪莲细胞培养物500 mg/Kg,低剂量组喂高脂饲料的同时饲以水母雪莲细胞培养物50 mg/Kg.给药1次/d,3周后采血,测定血脂水平及肝肾功能.主要观察指标:各组间血脂水平差异及肝肾功能变化.结果:高剂量组胆固醇、三酰甘油、低密度脂蛋白水平低于高脂模型组[(2.66±0.51)mmol/L,(3.23±0.57)mmol/L,P=0.030;(1.59±0.77)mmol/L,(2.48±0.83)mmol/L,P=0.023;(1.68±0.31)mmol/L,(2.07±0.43)mmol/L,P=0.032].高剂量组高密度脂蛋白水平高于高脂模型组[(0.98±0.29)mmol/L,(0.66±0.37)mmol/L,P=0.045].各组间肝肾功能差异无显著性意义(P>0.05).结论:水母雪莲细胞培养物对高脂大鼠具有调血脂的作用.%BACKGROUND: Wild saussurea medusa is at the edge of extinction. For this reason, the Academy of Military Medical Sciences has established a method to culture high-yield S. medusa cell lines.OBJECTIVE: To investigate the effects of the cell lines of saussurea medusa(CLSM) on regulating blood lipid in rats with hyperlipidemia.DESIGN: A completely randomized controlled experimental study.SETTING: This study was done by the Department of Cardiology in the General Hospital of Chinese PLA and the Institute of Biotechnology in Academy of Military Medical Sciences.PARTICIPANTS: The

  4. Mechanistic site-based emulation of a global ocean biogeochemical model (MEDUSA 1.0 for parametric analysis and calibration: an application of the Marine Model Optimization Testbed (MarMOT 1.1

    Directory of Open Access Journals (Sweden)

    J. C. P. Hemmings

    2015-03-01

    Full Text Available Biogeochemical ocean circulation models used to investigate the role of plankton ecosystems in global change rely on adjustable parameters to capture the dominant biogeochemical dynamics of a complex biological system. In principle, optimal parameter values can be estimated by fitting models to observational data, including satellite ocean colour products such as chlorophyll that achieve good spatial and temporal coverage of the surface ocean. However, comprehensive parametric analyses require large ensemble experiments that are computationally infeasible with global 3-D simulations. Site-based simulations provide an efficient alternative but can only be used to make reliable inferences about global model performance if robust quantitative descriptions of their relationships with the corresponding 3-D simulations can be established. The feasibility of establishing such a relationship is investigated for an intermediate complexity biogeochemistry model (MEDUSA coupled with a widely used global ocean model (NEMO. A site-based mechanistic emulator is constructed for surface chlorophyll output from this target model as a function of model parameters. The emulator comprises an array of 1-D simulators and a statistical quantification of the uncertainty in their predictions. The unknown parameter-dependent biogeochemical environment, in terms of initial tracer concentrations and lateral flux information required by the simulators, is a significant source of uncertainty. It is approximated by a mean environment derived from a small ensemble of 3-D simulations representing variability of the target model behaviour over the parameter space of interest. The performance of two alternative uncertainty quantification schemes is examined: a direct method based on comparisons between simulator output and a sample of known target model "truths" and an indirect method that is only partially reliant on knowledge of the target model output. In general, chlorophyll

  5. Entre la Venadita y la Medusa

    Directory of Open Access Journals (Sweden)

    Valcárcel, Amelia

    2008-06-01

    Full Text Available Feminism has made in the last decades relevant advances towards equity between men and women in western societies. However, both mysogyny and gynophobia are still at work, giving as a result a «deflation of expectations» among women who enter the worlds of politics, information, corporations, economic power, knowledge, religion or art, and find a glass ceiling in full operation. The paper focuses on women artists, examines the anger expressed in feminist art as an answer to exclusion, and argues for feminist strategies of analysis and correction of inequalities.

    El feminismo ha conseguido en los últimos años importantes avances hacia la igualdad entre hombres y mujeres en las sociedades occidentales. Y, sin embargo, tanto la misoginia como la ginofobia siguen vigentes, provocando una «deflación de expectativas » entre las mujeres que se incorporan a los mundos de la política, la información, las organizaciones empresariales, el poder económico, el saber, la religión o la creatividad, y se topan con el techo de cristal a pleno funcionamiento. El artículo se centra en las mujeres creadoras para examinar la cólera expresada en el arte feminista como respuesta a la exclusión y defender estrategias feministas de análisis y corrección de desigualdades.

  6. Beyond Medusa: recovering history on stage

    NARCIS (Netherlands)

    Röttger, K.

    2010-01-01

    The theatre work of the Austrian Elfriede Jelinek is known for its critique of mythology. In her recent "work in progress", which closely follows media reports about the Iraq war and the tortures in Abu Ghraib, Jelinek concentrates on the mythologizing effects of a "wartainment" that a supposedly al

  7. Medusa: Nuclear explosive propulsion for interplanetary travel

    Science.gov (United States)

    Solem, Johndale C.

    1993-01-01

    Because of the deleterious effects of galactic cosmic radiation, solar flares, zero gravity and psychological stress, there is strong motivation to develop high-specific-impulse and high-thrust spacecraft for rapid transport of astronauts between planets. A novel spacecraft design is presented using a large lightweight sail (spinnaker) driven by pressure pulses from a series of nuclear explosions. The spacecraft appears to be a singularly competent and economical vehicle for high-speed interplanetary travel. The mass of the spinnaker is theoretically independent of the size of its canopy or the length of its tethers. Consequently, the canopy can be made very large to minimize radiation damage from the nuclear explosions and the tethers can be made very long to mitigate radiation hazard to the crew. The pressure from the nuclear explosion imparts a large impulsive acceleration to the lightweight spinnaker, which must be translated to a small smooth acceleration of the space capsule either by using the elasticity of the tethers or a servo winch in the space capsule, or a combination of the two. If elasticity alone is used, the maximum acceleration suffered by the space capsule is inversely propotional to the tether length. The use of very long tethers allows the spacecraft to achieve high velocities without using an exceedingly large number of bombs, a feature unavailable to previous forms of nuclear-explosive propulsion. Should the political questions connected with an unconventional use of nuclear explosives be favorably resolved, the proposal will be a good candidate for propulsion in the Mars mission.

  8. Entre la Venadita y la Medusa

    OpenAIRE

    Valcárcel, Amelia

    2008-01-01

    Feminism has made in the last decades relevant advances towards equity between men and women in western societies. However, both mysogyny and gynophobia are still at work, giving as a result a «deflation of expectations» among women who enter the worlds of politics, information, corporations, economic power, knowledge, religion or art, and find a glass ceiling in full operation. The paper focuses on women artists, examines the anger expressed in feminist art as an answer to exclusion, and arg...

  9. 响应面法优化小刺猴头菌寡糖的纯化工艺研究%On the Optimization of Purification Technique of Oligosaccharide of H. caput- medusae (Bull. Fr. ) Pers. using Response Surface Method

    Institute of Scientific and Technical Information of China (English)

    孙文怡; 刘金阳; 刘瑜; 宋慧

    2011-01-01

    采用盐析法对小刺猴头菌寡糖进行纯化,在pH值、硫酸铵饱和度和溶液浓度3个单因素试验的基础上,根据中心组合(Box—Benhnken)试验设计原理,以粗多糖中的蛋白去除率为指标响应值作响应面和等高线,分析各个因素的显著性和交互作用,得出利用硫酸铵盐析法去除寡糖中杂蛋白的工艺条件为:pH值为5.91,硫酸铵饱和度为57%,溶液浓度为4%。%The experiment was conducted using salting - out method to purify the oligosaccharide of H. caput - medusae ( Bull. Fr. ) Pers.. The pH, the saturation of ammonium sulfate and the solution concentration were investigated using single - factor experiment. Then the purification conditions of oligosaccharide of H. caput - medusae ( Bull. Fr. ) Pers. on the rationale of BoxBenhnken design of Response Surface Methodology experiment were optimized, and the response surface and contour were drawn out with the removal rate of protein in crude oligosaceharide content as criteria. Through the analysis of the distinctiveness and interactions between various factors, we can conclude that the conditions for eliminating proteins from oligosaccaride by saltingout method are that pH value is 5.91, the saturation of ammonium sulfate is 57%, and the solution concentration is 4 %.

  10. Biología reproductiva de la medusa bola de cañón Stomolophus meleagris en la laguna Las Guásimas, Sonora, México Reproductive biology of the Cannonball Jellyfish Stomolophus meleagris in Las Guasimas Lagoon, Sonora, Mexico

    Directory of Open Access Journals (Sweden)

    Liliana Carvalho-Saucedo

    2011-04-01

    Full Text Available Este trabajo describe aspectos de la biología reproductiva de la fase medusa de Stomolophus meleagris. Durante el periodo de enero a mayo de 2006, se recolectaron 34 ejemplares cada mes, en la laguna Las Guásimas, Sonora. Los ejemplares fueron pesados y medidos. Sus gónadas fueron retiradas y procesadas siguiendo la técnica de tinción estándar con hematoxilina eosina. El desarrollo gonádico de machos y hembras se caracterizó por ser continuo y tener cuatro fases. La proporción sexual fue 1:1 y no se detectaron diferencias significativas entre machos y hembras en cuanto a su longitud y peso. La actividad reproductiva se presentó entre febrero y mayo, mientras que la maduración máxima en ambos sexos ocurrió en abril y mayo. La maduración gonadal y la reproducción se relacionaron con el aumento progresivo de la temperatura y clorofila a.This paper describes basic aspects of the reproductive biology of the medusa phase of Stomolophus meleagris. From January to May 2006, 34 individuals were collected every month, in Las Guásimas Lagoon, Sonora, México. Specimens were weighed and measured; their gonads were removed and processed following the standard histological hematoxylineosin staining technique. The gonad development of both males and females was continuous and had four phases. Sex ratio was 1:1 and no significant differences were detected between males and females in length or weight. .Reproductive activity was present from February to May, whereas the maximum maturation in both sexes occurred in April to May. Gonadic maturation and reproduction were related to the gradual increase of temperature and chlorophyll a.

  11. Jellyfish (Chrysaora lactea, Cnidaria, Semaeostomeae aggregations in southern Brazil and consequences of stings in humans

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    Antonio C Marques

    2014-11-01

    Full Text Available The frequency of jellyfish blooms is generating a world-wide discussion about medusae population explosions, mainly those associated with stings. We report over 20,000 envenomations caused by Chrysaora lactea (Scyphozoa in the State of Paraná (southern Brazil during the austral summer of 2011 -2012. Envenomations were considered mild, but almost 600 cases were treated in emergency services, with either toxic and allergic reactions, some with systemic manifestations. We proposed non-exclusive hypotheses to explain this large number of cases.

  12. Complete mitochondrial genome of the jellyfish, Chrysaora quinquecirrha (Cnidaria, Scyphozoa).

    Science.gov (United States)

    Hwang, Dae-Sik; Park, Eunji; Won, Yong-Jin; Lee, Woo-Jin; Shin, Kyoungsoon; Lee, Jae-Seong

    2014-02-01

    We sequenced 16,775 bp of the linear mitochondrial DNA of the jellyfish Chrysaora quinquecirrha and characterized them. C. quinquecirrha has 13 protein-coding genes (PCGs), 16S rRNA and 12S rRNA with 3 tRNAs (tRNA-Leu, tRNA-Ser(TGA), tRNA-Met) as shown in Aurelia sp. nov. Both have another two PCGs such as helicase and orf363 with telomeres at both ends. The PCGs of C. quinquecirrha shows anti-G bias on 2nd and 3rd positions of PCGs as well as anti-C bias on 1st and 3rd positions of PCGs.

  13. [Reason to split the genus Aurelia. Mesoglein from two populations differ].

    Science.gov (United States)

    Kotova, A V; Podgornaia, O I; Adonin, L S

    2015-01-01

    The medusa, Aurelia aurita (Scyphozoa, Cnidaria), is considered to be a cosmopolitan species with a worldwide distribution in most seas from the poles to the tropics. Cnidarian is thought to possess two tissue layers: endoderm (gastroderm) and ectoderm, which are separated by huge mesoglea in medusa. The basic morphology of medusa is similar in different populations. Previously we have determined a new protein "mesoglein" as one of the main components of mesoglea. Deduced amino acid sequence of mesoglein contains Zona Pellucida (ZP) domain. In this paper, we have comparied of mesoglein and its gene in medusa from three habitats (White Sea (WsA), Black Sea (BsA), Japonic Sea (JsA)). The set of the mesoglea protein bands after SDS-PAGE is similar in all samples. Nevertheless, JsA mesogleins' M(r) is 53-55 kDa, while WsA and BsA mesogleins have M(r) of 47 kDa. Antibodies raised against WsA mesoglein recognize only mesogleins with M(r) of 47 kDa, but not 53-55 kDa, both on immunoblot and immunocytochemistry. Mesogleal cells and elastic fibrils are stained intensively in the mesoglea both from WsA and BsA but not from JsA. The possibility of gene divergency was checked by PCR with primers specific for WsA mesoglein gene. PCR products of expected length obtained on polyA-cDNA template from mesogleal cells of WsA and BsA medusa but not on cDNA of JsA medusa. Our results evidence that there are two different species in genus Aurelia: Aurelia aurita inhabits White and Black Seas while Aurelia sp. inhabits Japonic Sea. This is consistent with findings of other recept molecular biological studies.

  14. Jellyfish life histories: role of polyps in forming and maintaining scyphomedusa populations.

    Science.gov (United States)

    Lucas, Cathy H; Graham, William M; Widmer, Chad

    2012-01-01

    Large population fluctuations of jellyfish occur over a variety of temporal scales, from weekly to seasonal, inter-annual and even decadal, with some regions of the world reported to be experiencing persistent seasonal bloom events. Recent jellyfish research has focussed on understanding the causes and consequences of these population changes, with the vast majority of studies considering the effect of changing environmental variables only on the pelagic medusa. But many of the bloom-forming species are members of the Scyphozoa with complex metagenic life cycles consisting of a sexually reproducing pelagic medusa and asexually reproducing benthic polyp. Recruitment success during the juvenile (planula, polyp and ephyrae) stages of the life cycle can have a major effect on the abundance of the adult (medusa) population, but until very recently, little was known about the ecology of the polyp or scyphistoma phase of the scyphozoan life cycle. The aim of this review is to synthesise the current state of knowledge of polyp ecology by examining (1) the recruitment and metamorphosis of planulae larvae into polyps, (2) survival and longevity of polyps, (3) expansion of polyp populations via asexual propagation and (4) strobilation and recruitment of ephyrae (juvenile medusae). Where possible, comparisons are made with the life histories of other bentho-pelagic marine invertebrates so that further inferences can be made. Differences between tropical and temperate species are highlighted and related to climate change, and populations of the same species (in particular Aurelia aurita) inhabiting different habitats within its geographic range are compared. The roles that polyps play in ensuring the long-term survival of jellyfish populations as well as in the formation of bloom populations are considered, and recommendations for future research are presented.

  15. Digenean metacercaria (Trematoda, Digenea, Lepocreadiidae parasitizing "coelenterates" (Cnidaria, Scyphozoa and Ctenophora from Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    André Carrara Morandini

    2005-06-01

    Full Text Available Metacercaria specimens of the genus Opechona (Trematoda: Digenea: Lepocreadiidae are described parasitizing "coelenterates" (scyphomedusae and ctenophores from Southeastern Brazil (São Paulo state. The worms are compared to other Opechona species occurring on the Brazilian coast, but no association has been made because only adult forms of these species have been described. Suppositions as to the possible transference of the parasites are made.Exemplares de metacercárias do gênero Opechona (Trematoda: Digenea: Lepocreadiidae são descritos parasitando "celenterados" (cifomedusas e ctenóforos no sudeste do Brasil (estado de São Paulo. Os vermes foram comparados a outras espécies de Opechona ocorrentes no litoral brasileiro, porém nenhuma associação foi realizada devido às demais espécies terem sido descritas a partir de exemplares adultos. São apresentadas suposições sobre as possíveis formas de transferência dos parasitas.

  16. [On some features of embryonic development and metamorphosis of Aurelia aurita (Cindaria, Scyphozoa)].

    Science.gov (United States)

    Maĭorova, T D; Kosevich, I A; Melekhova, O P

    2012-01-01

    Aurelia aurita is a cosmopolite species of scyphomedusae. Its major structural patterns and life cycle are well investigated. This work provides a detailed study on development and structure of the planula in A. aurita until it completes its metamorphosis. Lifetime observations and histological study performed during the settlement and metamorphosis of the planulae demonstrated that the inner manibrium linen of primary polyp (gastroderm) develops from the ectoderm of the planula posterior end. The spatial and temporal dynamics of serotonergic cells from the early embryonic stages until the formation of the primary polyp were studied for the first time. In addition, the distribution oftyrosinated tubulin and neuropeptide RFamide at different stages ofA. aurita development were studied.

  17. Life Cycle Reversal in Aurelia sp.1 (Cnidaria, Scyphozoa): e0145314

    National Research Council Canada - National Science Library

    Jinru He; Lianming Zheng; Wenjing Zhang; Yuanshao Lin

    2015-01-01

      The genus Aurelia is one of the major contributors to jellyfish blooms in coastal waters, possibly due in part to hydroclimatic and anthropogenic causes, as well as their highly adaptive reproductive traits...

  18. Bacterially induced stolon settlement in the scyphopolyp of Aurelia aurita (Cnidaria, Scyphozoa)

    Science.gov (United States)

    Schmahl, G.

    1985-03-01

    Unsettled stoloniferous scyphopolyps of Aurelia aurita Lamarck were offered different substrates for settlement under defined conditions. On addition of different biogenic and abiotic substrates, a pure strain of bacteria, a species of Micrococcaceae, was observed to trigger the settlement of the stolon. The settlement reaction only takes place following direct contact with the bacteria; sterile filtrated culture medium of the same bacterial strain was not able to induce settlement. The bacteria were found to be effective on stolon settlement during the logarithmic growth phase, but not during the stationary phase.

  19. Complete mitochondrial genome of the moon jellyfish, Aurelia sp. nov. (Cnidaria, Scyphozoa).

    Science.gov (United States)

    Hwang, Dae-Sik; Park, Eunji; Won, Yong-Jin; Lee, Jae-Seong

    2014-02-01

    We sequenced 16,971 bp of the linear mitochondrial DNA of the moon jellyfish Aurelia sp. nov. and characterized it by comparing with Aurelia aurita. They had 13 protein-coding genes (PCGs), 16S rRNA and 12S rRNA with three tRNAs (tRNA-Leu, tRNA-Ser(TGA), tRNA-Met). Both have another two PCGs, orf969 and orf324 with telomeres at both ends. After comparison of Aurelia sp. nov. with Aurelia aurita, we found low-protein similarity of orf969 (59%) and orf324 (75%), respectively, while the other 13 PCGs showed 80% to 98% protein similarities.

  20. On natural metamorphosis inducers of the cnidarians Hydractinia echinata (Hydrozoa) and Aurelia aurita (Scyphozoa)

    Science.gov (United States)

    Kroiher, M.; Berking, S.

    1999-11-01

    Hydractinia echinata and Aurelia aurita produce motile larvae which undergo metamorphosis to sessile polyps when induced by external cues. The polyps are found at restricted sites, A. aurita predominantly on rocks close to the shore, H. echinata on shells inhabited by hermit crabs. It has been argued that the differential distribution of the polyps in their natural environment largely reflects the distribution of the natural metamorphosis-inducing cues. In the case of H. echinata, bacteria of the genus Alteromonas were argued to meet these conditions. We found that almost all substrates collected in the littoral to induce metamorphosis in H. echinata, and several bacterial strains isolated from the sea, including the common E. coli, induce metamorphosis efficiently. In A. aurita metamorphosis may be induced by the water-air interface, whereby metamorphosis precedes (final) settlement.

  1. Tentacle Transcriptome and Venom Proteome of the Pacific Sea Nettle, Chrysaora fuscescens (Cnidaria: Scyphozoa).

    Science.gov (United States)

    Ponce, Dalia; Brinkman, Diane L; Potriquet, Jeremy; Mulvenna, Jason

    2016-04-05

    Jellyfish venoms are rich sources of toxins designed to capture prey or deter predators, but they can also elicit harmful effects in humans. In this study, an integrated transcriptomic and proteomic approach was used to identify putative toxins and their potential role in the venom of the scyphozoan jellyfish Chrysaora fuscescens. A de novo tentacle transcriptome, containing more than 23,000 contigs, was constructed and used in proteomic analysis of C. fuscescens venom to identify potential toxins. From a total of 163 proteins identified in the venom proteome, 27 were classified as putative toxins and grouped into six protein families: proteinases, venom allergens, C-type lectins, pore-forming toxins, glycoside hydrolases and enzyme inhibitors. Other putative toxins identified in the transcriptome, but not the proteome, included additional proteinases as well as lipases and deoxyribonucleases. Sequence analysis also revealed the presence of ShKT domains in two putative venom proteins from the proteome and an additional 15 from the transcriptome, suggesting potential ion channel blockade or modulatory activities. Comparison of these potential toxins to those from other cnidarians provided insight into their possible roles in C. fuscescens venom and an overview of the diversity of potential toxin families in cnidarian venoms.

  2. Tentacle Transcriptome and Venom Proteome of the Pacific Sea Nettle, Chrysaora fuscescens (Cnidaria: Scyphozoa

    Directory of Open Access Journals (Sweden)

    Dalia Ponce

    2016-04-01

    Full Text Available Jellyfish venoms are rich sources of toxins designed to capture prey or deter predators, but they can also elicit harmful effects in humans. In this study, an integrated transcriptomic and proteomic approach was used to identify putative toxins and their potential role in the venom of the scyphozoan jellyfish Chrysaora fuscescens. A de novo tentacle transcriptome, containing more than 23,000 contigs, was constructed and used in proteomic analysis of C. fuscescens venom to identify potential toxins. From a total of 163 proteins identified in the venom proteome, 27 were classified as putative toxins and grouped into six protein families: proteinases, venom allergens, C-type lectins, pore-forming toxins, glycoside hydrolases and enzyme inhibitors. Other putative toxins identified in the transcriptome, but not the proteome, included additional proteinases as well as lipases and deoxyribonucleases. Sequence analysis also revealed the presence of ShKT domains in two putative venom proteins from the proteome and an additional 15 from the transcriptome, suggesting potential ion channel blockade or modulatory activities. Comparison of these potential toxins to those from other cnidarians provided insight into their possible roles in C. fuscescens venom and an overview of the diversity of potential toxin families in cnidarian venoms.

  3. The Bright Side of Gelatinous Blooms: Nutraceutical Value and Antioxidant Properties of Three Mediterranean Jellyfish (Scyphozoa).

    Science.gov (United States)

    Leone, Antonella; Lecci, Raffaella Marina; Durante, Miriana; Meli, Federica; Piraino, Stefano

    2015-07-29

    Jellyfish are recorded with increasing frequency and magnitude in many coastal areas and several species display biological features comparable to the most popular Asiatic edible jellyfish. The biochemical and antioxidant properties of wild gelatinous biomasses, in terms of nutritional and nutraceutical values, are still largely unexplored. In this paper, three of the most abundant and commonly recorded jellyfish species (Aurelia sp.1, Cotylorhiza tuberculata and Rhizostoma pulmo) in the Mediterranean Sea were subject to investigation. A sequential enzymatic hydrolysis of jellyfish proteins was set up by pepsin and collagenase treatments of jellyfish samples after aqueous or hydroalcoholic protein extraction. The content and composition of proteins, amino acids, phenolics, and fatty acids of the three species were recorded and compared. Protein content (mainly represented by collagen) up to 40% of jellyfish dry weight were found in two of the three jellyfish species (C. tuberculata and R. pulmo), whereas the presence of ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) was significantly higher in the zooxanthellate jellyfish C. tuberculata only. Remarkable antioxidant ability was also recorded from both proteinaceous and non proteinaceous extracts and the hydrolyzed protein fractions in all the three species. The abundance of collagen, peptides and other bioactive molecules make these Mediterranean gelatinous biomasses a largely untapped source of natural compounds of nutraceutical, cosmeceutical and pharmacological interest.

  4. Pelagia benovici sp. nov. (Cnidaria, Scyphozoa): a new jellyfish in the Mediterranean Sea.

    Science.gov (United States)

    Piraino, Stefano; Aglieri, Giorgio; Martell, Luis; Mazzoldi, Carlotta; Melli, Valentina; Milisenda, Giacomo; Scorrano, Simonetta; Boero, Ferdinando

    2014-05-07

    A bloom of an unknown semaestome jellyfish species was recorded in the North Adriatic Sea from September 2013 to early 2014. Morphological analysis of several specimens showed distinct differences from other known semaestome species in the Mediterranean Sea and unquestionably identified them as belonging to a new pelagiid species within genus Pelagia. The new species is morphologically distinct from P. noctiluca, currently the only recognized valid species in the genus, and from other doubtful Pelagia species recorded from other areas of the world. Molecular analyses of mitochondrial cytochrome c oxidase subunit I (COI) and nuclear 28S ribosomal DNA genes corroborate its specific distinction from P. noctiluca and other pelagiid taxa, supporting the monophyly of Pelagiidae. Thus, we describe Pelagia benovici sp. nov. Piraino, Aglieri, Scorrano & Boero.

  5. Cytotoxicity and hemolytic activity of jellyfish Nemopilema nomurai (Scyphozoa: Rhizostomeae) venom.

    Science.gov (United States)

    Kang, Changkeun; Munawir, Al; Cha, Mijin; Sohn, Eun-Tae; Lee, Hyunkyoung; Kim, Jong-Shu; Yoon, Won Duk; Lim, Donghyun; Kim, Euikyung

    2009-07-01

    The recent bloom of a giant jellyfish Nemopilema nomurai has caused a danger to sea bathers and fishery damages in the waters of China, Korea, and Japan. The present study investigated the cytotoxic and hemolytic activities of crude venom extract of N. nomurai using a number of in vitro assays. The jellyfish venom showed a much higher cytotoxic activity in H9C2 heart myoblast than in C2C12 skeletal myoblast (LC(50)=2 microg/mL vs. 12 microg/mL, respectively), suggesting its possible in vivo selective toxicity on cardiac tissue. This result is consistent with our previous finding that cardiovascular function is a target of the venom. In order to determine the stability of N. nomurai venom, its cytotoxicity was examined under the various temperature and pH conditions. The activity was relatively well retained at low environmental temperature (or=60 degrees C). In pH stability test, the venom has abruptly lost its activity at low pH environment (pH

  6. The Bright Side of Gelatinous Blooms: Nutraceutical Value and Antioxidant Properties of Three Mediterranean Jellyfish (Scyphozoa

    Directory of Open Access Journals (Sweden)

    Antonella Leone

    2015-07-01

    Full Text Available Jellyfish are recorded with increasing frequency and magnitude in many coastal areas and several species display biological features comparable to the most popular Asiatic edible jellyfish. The biochemical and antioxidant properties of wild gelatinous biomasses, in terms of nutritional and nutraceutical values, are still largely unexplored. In this paper, three of the most abundant and commonly recorded jellyfish species (Aurelia sp.1, Cotylorhiza tuberculata and Rhizostoma pulmo in the Mediterranean Sea were subject to investigation. A sequential enzymatic hydrolysis of jellyfish proteins was set up by pepsin and collagenase treatments of jellyfish samples after aqueous or hydroalcoholic protein extraction. The content and composition of proteins, amino acids, phenolics, and fatty acids of the three species were recorded and compared. Protein content (mainly represented by collagen up to 40% of jellyfish dry weight were found in two of the three jellyfish species (C. tuberculata and R. pulmo, whereas the presence of ω-3 and ω-6 polyunsaturated fatty acids (PUFAs was significantly higher in the zooxanthellate jellyfish C. tuberculata only. Remarkable antioxidant ability was also recorded from both proteinaceous and non proteinaceous extracts and the hydrolyzed protein fractions in all the three species. The abundance of collagen, peptides and other bioactive molecules make these Mediterranean gelatinous biomasses a largely untapped source of natural compounds of nutraceutical, cosmeceutical and pharmacological interest.

  7. Characterization and neutralization of Nemopilema nomurai (Scyphozoa: Rhizostomeae) jellyfish venom using polyclonal antibody.

    Science.gov (United States)

    Kang, Changkeun; Han, Dae-Yong; Park, Kwang-Il; Pyo, Min-Jung; Heo, Yunwi; Lee, Hyunkyoung; Kim, Gon Sup; Kim, Euikyung

    2014-08-01

    Jellyfish stings have often caused serious health concerns for sea bathers especially in tropical waters. In the coastal areas of Korea, China and Japan, the blooming and stinging accidents of poisonous jellyfish species have recently increased, including Nemopilema nomurai. We have generated a polyclonal antibody against N. nomurai jellyfish venom (NnV) by the immunization of white rabbits with NnV antigen. In the present study, the antibody has been characterized for its neutralizing effect against NnV. At first, the presence of NnV polyclonal antibody has been confirmed from the immunized rabbit serum by Enzyme linked immunosorbent assay (ELISA). Then, the neutralizing activities of the polyclonal antibody have been investigated using cell-based toxicity test, hemolysis assay, and mice lethality test. When the polyclonal antibody was preincubated with NnV, it shows a high effectiveness in neutralizing the NnV toxicities in a concentration-dependent manner. Moreover, we explored proteomic analyses using 2-D SDS-PAGE and MALDI-TOF mass spectrometry to illustrate the molecular identities of the jellyfish venom. From this, 18 different protein families have been identified as jellyfish venom-derived proteins; the main findings of which are matrix metalloproteinase-14, astacin-like metalloprotease toxin 3 precursor. It is expected that the present results would have contributed to our understandings of the envenomation by N. nomurai, their treatment and some valuable knowledge on the pathological processes of the jellyfish stinging.

  8. Pelagia noctiluca (Scyphozoa Crude Venom Injection Elicits Oxidative Stress and Inflammatory Response in Rats

    Directory of Open Access Journals (Sweden)

    Giuseppe Bruschetta

    2014-04-01

    Full Text Available Cnidarian toxins represent a rich source of biologically active compounds. Since they may act via oxidative stress events, the aim of the present study was to verify whether crude venom, extracted from the jellyfish Pelagia noctiluca, elicits inflammation and oxidative stress processes, known to be mediated by Reactive Oxygen Species (ROS production, in rats. In a first set of experiments, the animals were injected with crude venom (at three different doses 6, 30 and 60 µg/kg, suspended in saline solution, i.v. to test the mortality and possible blood pressure changes. In a second set of experiments, to confirm that Pelagia noctiluca crude venom enhances ROS formation and may contribute to the pathophysiology of inflammation, crude venom-injected animals (30 µg/kg were also treated with tempol, a powerful antioxidant (100 mg/kg i.p., 30 and 60 min after crude venom. Administration of tempol after crude venom challenge, caused a significant reduction of each parameter related to inflammation. The potential effect of Pelagia noctiluca crude venom in the systemic inflammation process has been here demonstrated, adding novel information about its biological activity.

  9. Ecosystem relevance of variable jellyfish biomass in the Irish Sea between years, regions and water types

    Science.gov (United States)

    Bastian, Thomas; Lilley, Martin K. S.; Beggs, Steven E.; Hays, Graeme C.; Doyle, Thomas K.

    2014-08-01

    Monitoring the abundance and distribution of taxa is essential to assess their contribution to ecosystem processes. For marine taxa that are difficult to study or have long been perceived of little ecological importance, quantitative information is often lacking. This is the case for jellyfish (medusae and other gelatinous plankton). In the present work, 4 years of scyphomedusae by-catch data from the 2007-2010 Irish Sea juvenile gadoid fish survey were analysed with three main objectives: (1) to provide quantitative and spatially-explicit species-specific biomass data, for a region known to have an increasing trend in jellyfish abundance; (2) to investigate whether year-to-year changes in catch-biomass are due to changes in the numbers or in the size of medusa (assessed as the mean mass per individual), and (3) to determine whether inter-annual variation patterns are consistent between species and water masses. Scyphomedusae were present in 97% of samples (N = 306). Their overall annual median catch-biomass ranged from 0.19 to 0.92 g m-3 (or 8.6 to 42.4 g m-2). Aurelia aurita and Cyanea spp. (Cyanea lamarckii and Cyanea capillata) made up 77.7% and 21.5% of the total catch-biomass respectively, but species contributions varied greatly between sub-regions and years. No consistent pattern was detected between the distribution and inter-annual variations of the two genera, and contrasting inter-annual patterns emerged when considering abundance either as biomass or as density. Significantly, A. aurita medusae were heavier in stratified than in mixed waters, which we hypothesize may be linked to differences in timing and yield of primary and secondary productions between water masses. These results show the vulnerability of time-series from bycatch datasets to phenological changes and highlight the importance of taking species- and population-specific distribution patterns into account when integrating jellyfish into ecosystem models.

  10. Environmental control of asexual reproduction and somatic growth of Aurelia spp. (Cnidaria, Scyphozoa) polyps from the Adriatic Sea.

    Science.gov (United States)

    Hubot, Nathan; Lucas, Cathy H; Piraino, Stefano

    2017-01-01

    Polyps of two moon jellyfish species, Aurelia coerulea and A. relicta, from two Adriatic Sea coastal habitats were incubated under multiple combinations of temperature (14, 21°C), salinity (24, 37 ppt) and food regime (9.3, 18.6, 27.9 μg C ind-1 week-1) to comparatively assess how these factors may influence major asexual reproduction processes in the two species. Both species exhibited a shared pattern of budding mode (Directly Budded Polyps: DBP; Stolonal Budded Polyps: SBP), with DBP favoured under low food supply (9.3 μg C ind -1 week-1) and low temperature (14°C), and SBP dominant under high temperature (21°C). However, A. coerulea showed an overall higher productivity than A. relicta, in terms of budding and podocyst production rates. Further, A. coerulea exhibited a wide physiological plasticity across different temperatures and salinities as typical adaptation to ecological features of transitional coastal habitats. This may support the hypothesis that the invasion of A. coerulea across coastal habitats worldwide has been driven by shellfish aquaculture, with scyphistoma polyps and resting stages commonly found on bivalve shells. On the contrary, A. relicta appears to be strongly stenovalent, with cold, marine environmental optimal preferences (salinity 37 ppt, T ranging 14-19°C), corroborating the hypothesis of endemicity within the highly peculiar habitat of the Mljet lake. By exposing A. relicta polyps to slightly higher temperature (21°C), a previously unknown developmental mode was observed, by the sessile polyp regressing into a dispersive, temporarily unattached and tentacle-less, non-feeding stage. This may allow A. relicta polyps to escape climatic anomalies associated to warming of surface layers and deepening of isotherms, by moving into deeper, colder layers. Overall, investigations on species-specific eco-physiological and ontogenetic potentials of polyp stages may contribute to clarify the biogeographic distribution of jellyfish and the phylogenetic relationships among evolutionary related sister clades.

  11. Induction of stolon settlement in the scyphopolyps of Aurelia aurita (Cnidaria, Scyphozoa, Semaeostomeae) by glycolipids of marine bacteria

    Science.gov (United States)

    Schmahl, G.

    1985-06-01

    The settlement of pedal stolons of scyphopolyps of Aurelia aurita Lamarck could be induced by addition of a species of bacteria from the family Micrococcaceae. After treatment of the bacteria with several organic solvents a crude lipid extract free of bacteria could be obtained which was shown to be effective in inducing stolon settlement. Crude lipids extracted from the late logarithmic growth phase had an optimal effect on stolon attachment, in contrast to previously published experiments showing that all logarithmic phases of bacteria had the same level of effectiveness. After separation of the crude lipid extracts by thin layer chromatography and subsequent bioassay of the reeluated substances, acylgalactosidyldiglyceride and monogalactosidyldiglyceride were identified as the effective substances. Monogalactosidyldiglyceride was only found in bacteria from the medium logarithmic growth phase, whereas the former was found at all stages. The effectiveness of acylgalactosidyldiglyceride was independent of the growth phase of the extracted bacteria.

  12. Crude venom from nematocysts of Pelagia noctiluca (Cnidaria: Scyphozoa) elicits a sodium conductance in the plasma membrane of mammalian cells

    Science.gov (United States)

    Morabito, Rossana; Costa, Roberta; Rizzo, Valentina; Remigante, Alessia; Nofziger, Charity; La Spada, Giuseppa; Marino, Angela; Paulmichl, Markus; Dossena, Silvia

    2017-01-01

    Cnidarians may negatively impact human activities and public health but concomitantly their venom represents a rich source of bioactive substances. Pelagia noctiluca is the most venomous and abundant jellyfish of the Mediterranean Sea and possesses a venom with hemolytic and cytolytic activity for which the mechanism is largely unknown. Here we show that exposure of mammalian cells to crude venom from the nematocysts of P. noctiluca profoundly alters the ion conductance of the plasma membrane, therefore affecting homeostatic functions such as the regulation and maintenance of cellular volume. Venom-treated cells exhibited a large, inwardly rectifying current mainly due to permeation of Na+ and Cl‑, sensitive to amiloride and completely abrogated following harsh thermal treatment of crude venom extract. Curiously, the plasma membrane conductance of Ca2+ and K+ was not affected. Current-inducing activity was also observed following delivery of venom to the cytosolic side of the plasma membrane, consistent with a pore-forming mechanism. Venom-induced NaCl influx followed by water and consequent cell swelling most likely underlie the hemolytic and cytolytic activity of P. noctiluca venom. The present study underscores unique properties of P. noctiluca venom and provides essential information for a possible use of its active compounds and treatment of envenomation.

  13. [Lipid variation in oocytes of the jellyfish Stomolophus meleagris (Scyphozoa: Rhizostomeae) from Las Guasimas Lagoon, Mexico, during gonadal development].

    Science.gov (United States)

    Carvalho-Saucedo, Liliana; García-Domínguez, Federico; Rodríguez-Jaramillo, Carmen; López-Martínez, Juana

    2010-03-01

    The jellyfish Stomolophus meleagris has potential for commercial exploitation but there is little information on their reproductive biology. This paper seeks to evaluate some biochemical and demographic characteristics of the species. Samples were taken monthly during 2005 and 2006. Jellyfish collected in 2005 were used to describe the characteristics and quantity of oocyte triglycerides and phospholipids with the Sudan black technique, and to ascertain the degree of gonadal development and sex ratio by the hematoxylin-eosin technique. The 2006 jellyfish were used to determine the size at first maturity and protein and total lipids contents. Four stages of development in both sexes were determined, with a continuous gamete development. The highest percentage of mature organisms was recorded in April. The proportion of sexes was 0.7:1.3. We found higher concentrations of triglycerides than phospholipids in the cytoplasm. There was a positive correlation between triglycerides and the diameter of the oocyte. The size at first maturity for both sexes was 105 mm. The highest protein and lipids contents were obtained in April and March respectively.

  14. Patterns of trace element bioaccumulation in jellyfish Rhizostoma pulmo (Cnidaria, Scyphozoa) in a Mediterranean coastal lagoon from SE Spain.

    Science.gov (United States)

    Muñoz-Vera, Ana; Peñas Castejón, Jose Matías; García, Gregorio

    2016-09-15

    The effects of an abandoned mining area, exploited for centuries in the mining district of Cartagena-La Union, result in a continuous supply of heavy metals into the Mar Menor coastal lagoon after rain episodes. As a consequence, concentration of trace elements in water column and sediments of this ecosystem is usually higher than in other areas. For monitoring ecosystem health, this study assessed the ability of Rhizostoma pulmo to bioaccumulate trace elements. A total of 57 individuals were sampled at eight different sampling stations during the summer of 2012. Although the concentrations of different analyzed elements (Al, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Sn, and Pb) were moderate, bioconcentration levels in relation to seawater metal concentration were extremely high. In any case, the use or disposal of these organisms should consider their metal content, because of their potential environmental and health implications.

  15. Para além de Medusa: retomar a história no palco

    NARCIS (Netherlands)

    Röttger, K.

    2011-01-01

    O trabalho em teatro da austríaca Elfridine Jelinek é conhecido por sua crítica da mitologia. No seu recente 'work in progress', que segue de perto os relatos da mídia sobre a Guerra do Iraque e as torturas em Abu Ghraib, Jelinek concentra-se no efeito mitologizante do 'wartainment' que uma populaçã

  16. Sex, polyps, and medusae: Determination and maintenance of sex in cnidarians.

    Science.gov (United States)

    Siebert, Stefan; Juliano, Celina E

    2017-02-01

    Mechanisms of sex determination vary greatly among animals. Here we survey what is known in Cnidaria, the clade that forms the sister group to Bilateria and shows a broad array of sexual strategies and sexual plasticity. This observed diversity makes Cnidaria a well-suited taxon for the study of the evolution of sex determination, as closely related species can have different mechanisms, which allows for comparative studies. In this review, we survey the extensive descriptive data on sexual systems (e.g., gonochorism and hermaphroditism) and the plasticity of sex in various cnidarian taxa. Within Cnidaria, hydrozoans (e.g., Hydra, Hydractinia, and Clytia) are the best understood in regard to mechanistic determination and maintenance of sex, largely due to the discovery of the interstitial stem cells, which give rise to the germ cells. We also present a hypothesis for the evolution of the various sexual systems that are observed in Hydra. Finally, given the rapid advances in genome sequencing and editing, several exciting possible future directions for increasing our understanding of sex determination mechanisms in cnidarians are discussed. Mol. Reprod. Dev. 84: 105-119, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Para além de Medusa: retomar a história no palco

    NARCIS (Netherlands)

    Röttger, K.

    2011-01-01

    O trabalho em teatro da austríaca Elfridine Jelinek é conhecido por sua crítica da mitologia. No seu recente 'work in progress', que segue de perto os relatos da mídia sobre a Guerra do Iraque e as torturas em Abu Ghraib, Jelinek concentra-se no efeito mitologizante do 'wartainment' que uma

  18. Genetic variation in native and introduced populations of Taeniatherum caput-medusae (Poaceae)

    Science.gov (United States)

    Genetic analysis of both native and introduced populations of invasive species can be used to examine population origins and spread. Accurate delineation of an invasive species’ source populations can contribute to the search for specific and effective biological control agents. Medusahead, Taenia...

  19. MEDUSA - An overset grid flow solver for network-based parallel computer systems

    Science.gov (United States)

    Smith, Merritt H.; Pallis, Jani M.

    1993-01-01

    Continuing improvement in processing speed has made it feasible to solve the Reynolds-Averaged Navier-Stokes equations for simple three-dimensional flows on advanced workstations. Combining multiple workstations into a network-based heterogeneous parallel computer allows the application of programming principles learned on MIMD (Multiple Instruction Multiple Data) distributed memory parallel computers to the solution of larger problems. An overset-grid flow solution code has been developed which uses a cluster of workstations as a network-based parallel computer. Inter-process communication is provided by the Parallel Virtual Machine (PVM) software. Solution speed equivalent to one-third of a Cray-YMP processor has been achieved from a cluster of nine commonly used engineering workstation processors. Load imbalance and communication overhead are the principal impediments to parallel efficiency in this application.

  20. Biomimetic and Live Medusae Reveal the Mechanistic Advantages of a Flexible Bell Margin

    Science.gov (United States)

    2012-11-07

    2008) Medusan morphospace: phylogenetic constraints, biomechanical solutions, and ecological consequences. Invertebrate Biology 127: 265–290. 4...Fitzgerald T, Preidikman S, Balaras E, Balachandran B (2009) Influence of flexibility on the aerodynamic performance of a hovering wing. Journal of...Experimental Biology 212: 95–105. 15. Le TQ, Ko JH, Byun D, Park SH, Park HC (2010) Effect of Chord Flexure on Aerodynamic Performance of a Flapping Wing

  1. Medusas, bestiarios y teatralidades en el mundo contemporáneo

    Directory of Open Access Journals (Sweden)

    Alejandro Castillejo Cuellar

    2007-06-01

    Full Text Available Una lectura diferente de las concepciones sobre el hombre es aquella que llamaremos «pendular»: el concepto de «hombre» nos plantea una polaridad en cuanto a su forma de aprehenderlo, especialmente en una cultura que ha dado origen a la ciencia como forma primordial de acercarse al universo. ¿Es la totalidad, tal y como rezan los axiomas euclidianos, la suma de las partes? ¿Podrían nuestros «hábitos de pensamiento» permitir un universo en donde los fragmentos de la totalidad «sumaran más» que la totalidad misma? ¿Cuál es la relación, en resumen, entre la totalidad y sus fragmentos constituyentes? En este texto se explora la idea de mundocontemporáneo como una eclosión de alteridades. Se medita en la manera en cómo este proceso podría tener un efecto en la forma cómo el ser humano habita el espacio.

  2. From Cinderella to Medusa:Duality and Antithesis in Sylvia Plath’s Poetic Persona

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    在西方文坛上,女性诗人往往要面对"女性"与"诗人"的双重身份之间的冲突,这种冲突在普拉斯(Sylvia Plath)的诗歌里留下了十分明显的印迹。本文从分析普拉斯少年时期的诗歌入手,展示她的诗歌中人物性格上的双重性,并分析这种双重性如何在诗人后期诗歌中得到进一步的表现,同时揭示了普拉斯诗歌源于双重性的另一个重要特征:诗歌中所展现的矛盾冲突总是处于一种悬而未决的胶着状态。这种状态体现的是诗人在其短暂的一生中,追求生活与艺术完美统一的心路历程。

  3. [The plate in the zone of oocyte and germinal epithelium contact in scyphomedusa Aurelia aurita binds antibodies to ZP-domain-containing protein mesoglein].

    Science.gov (United States)

    Adonin, L S; Podgornaia, O I; Matveev, I V; Shaposhnikova, T G

    2009-01-01

    Cnidaria are lower multicellular animals with the body consisting of two epithelial layers. An extracellular substance--mesoglea--is situated between epidermal and gastrodermal layers of these animals. Mesoglein is one of the major mesogleal proteins of adult medusa of Scyphozoan jellyfish Aurelia aurita. Search for the known domains in mesoglein amino acid sequence reveals prominent zona pellucida (ZP) domain (which was found at first in the mammal oocyte zona pellucida proteins), so the protein belongs to ZP family of extracellular matrix proteins and it is an early metazoan member of ZP-domain-containing protein family. However, nothing is known about oogenesis related ZP-domain proteins in the lower multicellular animals. Oogenesis in Scyphozoa is described poorly. In this work morphological features of the zone in contact area between the oocyte and the germinal epithelium were investigated in semi-fine sections: To make it more convenient we identified seven stages according to the oocyte size and the structure found in this area was named the plate. It was shown that the components of the plate bound specifically the antibodies against mesoglein. So it seems the plate material contains ZP-domain proteins. Electrophoresis and immunoblot results give evidence that the proteins immunologically related to mesoglein have a higher molecular mass. It might be due to either the posttranslational modifications of the precursors or that they represent other proteins of ZP-domain family in Cnidaria.

  4. Where are the polyps? Molecular identification, distribution and population differentiation of Aurelia aurita jellyfish polyps in the southern North Sea area.

    Science.gov (United States)

    van Walraven, Lodewijk; Driessen, Floor; van Bleijswijk, Judith; Bol, Anneke; Luttikhuizen, Pieternella C; Coolen, Joop W P; Bos, Oscar G; Gittenberger, Adriaan; Schrieken, Niels; Langenberg, Victor T; van der Veer, Henk W

    For many species of metagenic jellyfish the location of the benthic polyps is unknown. To gain insight in the distribution, species composition and population structure of scyphozoan jellyfish polyps in the southern North Sea area, polyp samples were collected from natural and artificial substrates (settling plates, marina floats and wrecks) at ten inshore locations in the Netherlands, seven offshore locations in the North Sea and in the Gullmar Fjord in Sweden. Polyps were identified to species level by sequencing both a fragment of 18S rDNA and a fragment of mitochondrial COI, and comparing these sequences to reference sequences available in GenBank and to newly obtained sequences from medusae collected in the area. All polyps sequenced did belong to Aurelia aurita. For this species, molecular diversity in mitochondrial COI was high, with 50 haplotypes among 183 polyps. Population differentiation was detected between the Dogger Bank and other-more coastal-locations, indicating extremely low connectivity. No significant differences were found between coastal samples. The location of polyps of Cyanea capillata, Cyanea lamarckii, Chrysaora hysoscella and Rhizostoma octopus in the study area remains unresolved.

  5. Beat Medusa: The model angelic woman in the first romance novel of Carmen de Icaza. Femininity and traditionalism

    Directory of Open Access Journals (Sweden)

    Miguel Soler Gallo

    2015-12-01

    Full Text Available This paper presents an analysis of the traditional ideal of women in the first romance novel of Carmen de Icaza, a preeminent author in postwar Spanish literature. In the novel, two female models, an angel, representing the protagonist and the idea of traditional femininity, and the monster, who plays the antagonist and reflects the diametrically opposing view of morality to that imposed by the patriarchal society. In this novel Icaza spreads her conservative ideology to the female readers, mostly consumers of this kind of literature in the period after the Spanish Civil War, and emphasizes the values that should prevail in society.

  6. Medusas (Cnidaria: Hydrozoa de una zona de afloramiento costero, Bahía Culebra, Pacífico, Costa Rica

    Directory of Open Access Journals (Sweden)

    Karina Rodríguez-Sáenz

    2012-12-01

    Full Text Available Las hidromedusas tienen un papel importante en redes tróficas marinas debido a sus hábitos alimenticios depredadores. Este es el primer estudio de este grupo del zooplancton gelatinoso en un area de afloramiento costero en América Central. Durante seis meses de 1999, se estudió la abundancia de hidromedusas en cuatro estaciones en Bahía Culebra, Golfo de Papagayo, costa Pacífica de Costa Rica (10º 37’N-85º40’W. Se identificó un total de 53 especies de las que 26 son registros nuevos para Costa Rica, 21 son registros nuevos para América Central y 8 son nuevos registros para el Pacífico Oriental Tropical. Las especies más abundantes durante el estudio (con más de 30% de la abundancia total fueron Liriope tetraphylla, Solmundella bitentaculata y Aglaura hemistoma. Seis especies se presentaron en todos los muestreos, 10 especies se presentaron únicamente durante la época seca y 17 se presentaron únicamente durante la época lluviosa. Se mostraron diferencias significativas entre las épocas lluviosa y seca. La máxima abundancia promedio de hidromedusas (2.1±4.3 ind./m³ fue encontrada durante las fechas que se espera el afloramiento costero, indicado por alta concentración de oxígeno y baja temperatura. La rica composición de especies encontrada en Bahía Culebra puede ser el resultado de varios factores, incluyendo la condición prístina de la bahía, el transporte de especies por la Contra Corriente Nor-Ecuatorial (NECC y los aportes de origen terrestre. Se incluyen ilustraciones de las 15 especies más importantes para facilitar su identificación y promover estudios futuros en la región.

  7. Medusae from the sea around Laccadive group of islands (7 degrees-18 degrees N/69 degrees-76 degrees E)

    Digital Repository Service at National Institute of Oceanography (India)

    Santhakumari, V.

    Forty-four specie of hydromedusae belonging to 20 families were obtained from the samples collected during the period 1985-1987. Studies on abundance, diurnal variation and distribution are investigated. High densities were observed from samples...

  8. 白色霞水母生活史的实验室观察%Laboratory observations on the life cycle of Cyanea nozakii (Semeostomida, Scyphozoa)

    Institute of Scientific and Technical Information of China (English)

    董婧; 刘春洋; 王燕青; 王彬

    2006-01-01

    本文首次描述了白色霞水母从受精卵至碟状体的生活史.(1)包括受精卵、卵裂、囊胚以及浮浪幼虫等在内的胚胎发育各期均在开放的水体中,在20.8-21.4℃浮浪幼虫于受精后14 h出现;(2)浮浪幼虫在定置前形成一种凸面的圆形浮浪幼体囊,除了浮浪体囊外,螅状体还可产生足囊和通过产生匍匐茎形成囊胞进而发育成新的螅状体;(3)尽管偶而产生2个碟状体但仍为典型的单碟型横裂;(4)新释放的碟状幼体绝大多数为8个缘叶,8个感觉棍和8对钝圆的缘瓣,但畸形个体最多12个,最少6个缘叶;(5)雌雄个体间的交互作用对产卵和受精是非常重要的因子[动物学报52(2):389-395,2006].%The life cycle of the scyphozoan Cyanea nozakii Kishinouye was described from the fertilized-egg to the ephyra stage for the first time. (1) Embryogenesis from fertilized egg, cleavage of the zygote to blastula proceeded in the open sea water and planulae formed after 14 hours at 20.8 - 21.4℃. (2) Planulae formed plano-convex cysts(planulocysts)on attachment prior to forming scyphistomae. In addition to planulocysts, scyphistomae of Cyanea nozakii could produce podocysts and tendrils, which could also be involved in formation of new cysts and development of new scyphistomae. (3)Strobilation was typically monodiscous although strobilae liberated two ephyrae occasionally. (4) Newly liberated ephyrae had 8 marginal lobes, 8 rhopalia and 8 pairs of blunt-shaped lappets, aberrant specimens had maximum of 12 and minimum of 6 marginal lobes. (5) The interaction between mature individuals was important for spawning and fertilization [Acta Zoologica Sinica 52 (2): 389 - 395, 2006].

  9. Comparative study of the toxic effects of Chrysaora quinquecirrha (Cnidaria: Scyphozoa) and Chironex fleckeri (Cnidaria: Cubozoa) venoms using cell-based assays.

    Science.gov (United States)

    Ponce, Dalia; Brinkman, Diane L; Luna-Ramírez, Karen; Wright, Christine E; Dorantes-Aranda, Juan José

    2015-11-01

    The venoms of jellyfish cause toxic effects in diverse biological systems that can trigger local and systemic reactions. In this study, the cytotoxic and cytolytic effects of Chrysaora quinquecirrha and Chironex fleckeri venoms were assessed and compared using three in vitro assays. Venoms from both species were cytotoxic to fish gill cells and rat cardiomyocytes, and cytolytic in sheep erythrocytes. Both venoms decreased cell viability in a concentration-dependent manner; however, the greatest difference in venom potencies was observed in the fish gill cell line, wherein C. fleckeri was 12.2- (P = 0.0005) and 35.7-fold (P fleckeri and other cubozoan jellyfish species. In this study, proteins homologous to CfTX-1 and CfTX-2 toxins from C. fleckeri and CqTX-A toxin from Chironex yamaguchii were identified in C. quinquecirrha venom using tandem mass spectrometry. The presence and relative abundance of these proteins may explain the differences in venom potency between cubozoan and scyphozoan jellyfish and may reflect their importance in the action of venoms.

  10. Further observations on the strobilation of the coronate scyphozoan Linuche unguiculata (thimble jellyfish Observaciones adicionales sobre la estrobilación del escifozoario coronate Linuche unguiculata (medusa dedal

    Directory of Open Access Journals (Sweden)

    Lourdes Segura-Puertas

    2008-08-01

    Full Text Available In nature, strobilation of Linuche unguiculata is triggered by an increase in water temperature. However, the results showed that under laboratory conditions, it can be induced when scyphistomae are submitted to a sudden drop of 5 °C.En condiciones naturales, la estrobilación de Linuche unguiculata es desencadenada por un incremento en la temperatura del agua. Sin embargo, los resultados mostraron que en condiciones de laboratorio, este proceso puede ser inducido al someter a los escifistomas a un descenso brusco de la temperatura de 5 °C.

  11. A matter of tolerance: Distribution potential of scyphozoan polyps in a changing environment

    DEFF Research Database (Denmark)

    Goldstein, Josephine; Augustin, Christina B.; Bleich, Steffen

    2017-01-01

    Jellyfish blooms are unpredictable, unsustainable events, frequently affecting aquatic ecosystems severely. Of particular interest are the consequences of environmental change for jellyfish populations, especially in semi-enclosed habitats. Regional and seasonal changes in water chemistry...... psu caused irreversible degeneration of A. aurita and C. capillata polyps, respectively. Observed physiological limits suggest distribution of polyp populations of A. aurita in central and of C. capillata western parts of the Baltic Sea, while future climate changes may particularly restrict...

  12. 和歌山県田辺湾におけるベニクラゲ(ヒドロ虫綱, 花クラゲ目)のクラゲ世代の季節消長

    OpenAIRE

    河村, 真理子; 久保田, 信

    2005-01-01

    Turritopsis nutricula McCrady, transforming from mature medusa to polyp, habits all over waters around Japan, and the medusa from southern Japan is morphologically differed from the northern one. The survey of T. nutricula medusa was carried out at seven stations around Tanabe Bay, Wakayama Prefecture, southern Japan, every two weeks during August 2001-September 2002 with plankton net (56 cm diameter, 0.334 mm mesh). The medusa of T. nutricula appeared from 27 August to 22 October in 2001 and...

  13. Evolution of life cycle, colony morphology, and host specificity in the family Hydractiniidae (Hydrozoa, Cnidaria).

    Science.gov (United States)

    Miglietta, Maria Pia; Cunningham, Clifford W

    2012-12-01

    Biased transitions are common throughout the tree of life. The class hydrozoa is no exception, having lost the feeding medusa stage at least 70 times. The family hydractiniidae includes one lineage with pelagic medusae (Podocoryna) and several without (e.g., Hydractinia). The benthic colony stage also varies widely in host specificity and in colony form. The five-gene phylogeny presented here requires multiple transitions between character states for medusae, host specificity, and colony phenotype. Significant phylogenetic correlations exist between medusoid form, colony morphology, and host specificity. Species with nonfeeding medusae are usually specialized on a single host type, and reticulate colonies are correlated with nonmotile hosts. The history of feeding medusae is less certain. Podocoryna is nested within five lineages lacking medusae. This requires either repeated losses of medusae, or the remarkable re-evolution of a feeding medusa after at least 150 million years. Traditional ancestral reconstruction favors medusa regain, but a likelihood framework testing biased transitions cannot distinguish between multiple losses versus regain. A hypothesis of multiple losses of feeding medusae requires transient selection pressure favoring such a loss. Populations of species with feeding medusae are always locally rare and lack of feeding medusae does not result in restricted species distribution around the world. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  14. "Medusa's Eye": Comments on Jean-Paul Sartre's Philosophical Thinking in No Exit%“梅杜萨之眼”——从《禁闭》看萨特的哲学视界

    Institute of Scientific and Technical Information of China (English)

    余志平

    2001-01-01

    萨特名剧《禁闭》通过对地狱的戏剧性虚拟与对他人的戏剧性改写,在不断展开的戏剧过程之中表达了《存在与虚无》讨论人与人关系的基本观点和概念,从而使“他人就是地狱”这一主题蕴涵具有着高度的哲理性,显示出存在主义文学的基本特点。

  15. 雪莲对力竭性游泳小鼠肝肾保护作用的研究%The Experimental Study on the Liver and Kidney Protection of Saussurea Medusa Maxim in Exhaustive Swiming Mice

    Institute of Scientific and Technical Information of China (English)

    王沛; 郭魁亮; 张亚超; 张智慧; 孙晓丽; 王憬; 赵亚朴; 刘天鹏

    2004-01-01

    目的探讨雪莲对力竭性游泳小鼠肝、肾的保护作用.方法将雄性BALB/C小鼠随机分成4组:安静对照组、安静雪莲组、运动对照组和运动雪莲组.分别用蒸馏水和50%雪莲煎剂连续灌胃10 d,每日清晨1次.两个运动组进行一次性力竭性游泳(约4 h),所有小鼠采集血清测丙氨酸转氨酶(ALT)、门冬氨酸转氨酶(AST)、血氨(Ammo)、尿酸(UA)、肌酐(Cr)和尿素氮(BUN).结果运动对照组小鼠血清诸项生化指标明显升高,与安静对照组比较差异显著(P<0.01);运动雪莲组也有升高,与安静对照组比较差异显著(P<0.01),但与运动对照组比较下降明显,也存在显著差异(P<0.01).结论雪莲对力竭性游泳过程中造成的小鼠肝、肾损伤有一定的保护作用.

  16. Neuropeptides in cnidarians

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, Cornelis J.P.; Williamson, Michael; Hansen, Georg Nørgaard

    2002-01-01

    Cnidarians are the lowest animal group having a nervous system. In the primitive nervous systems of cnidarians, peptides play important roles as neurotransmitters or neurohormones. So far, we have isolated and sequenced about 35 neuropeptides from different cnidarian classes (Hydrozoa, Scyphozoa,...

  17. A study on the Gut contents of six Leathery Turtles Dermochelys Coriacea (Linnaeus) (Reptilia: Testudines: Dermochelyidae) from British waters and from the Netherlands

    NARCIS (Netherlands)

    Hartog, den J.C.; Nierop, van M.M.

    1984-01-01

    Microscopical investigations of the gut contents of six individuals of Dermochelys coriacea from southern England and the North Sea revealed the presence in all of these of numerous nematocysts, mainly scyphozoan. Only six species of Scyphozoa occur in British shallow waters and in the North Sea,

  18. Medusivorous fishes, a review

    NARCIS (Netherlands)

    Ates, R.M.L.

    1988-01-01

    A preliminary review is presented of fish species having consumed pelagic Cnidaria (Scyphozoa and Hydrozoa) as well as Ctenophora. Quantitative data are scarce. Knowledge of morphological and physiological adaptations of fishes foraging on gelatinous plankton is almost non-existent. Many fish specie

  19. A study on the Gut contents of six Leathery Turtles Dermochelys Coriacea (Linnaeus) (Reptilia: Testudines: Dermochelyidae) from British waters and from the Netherlands

    NARCIS (Netherlands)

    Hartog, den J.C.; Nierop, van M.M.

    1984-01-01

    Microscopical investigations of the gut contents of six individuals of Dermochelys coriacea from southern England and the North Sea revealed the presence in all of these of numerous nematocysts, mainly scyphozoan. Only six species of Scyphozoa occur in British shallow waters and in the North Sea, vi

  20. Planktonic coelenterates collected in the North Atlantic Ocean

    NARCIS (Netherlands)

    Soest, van R.W.M.

    1973-01-01

    This short faunistic note contains a report on the species of Scyphozoa, Hydromedusae, Siphonophora and Ctenophora that were collected by OWS “Cirrus” and “Cumulus”, R.V. “Tridens” and HMS “Snellius” in the North Atlantic Ocean between 22° N and 66° N. In all, 61 species have been captured. New reco

  1. Medusivorous fishes, a review

    NARCIS (Netherlands)

    Ates, R.M.L.

    1988-01-01

    A preliminary review is presented of fish species having consumed pelagic Cnidaria (Scyphozoa and Hydrozoa) as well as Ctenophora. Quantitative data are scarce. Knowledge of morphological and physiological adaptations of fishes foraging on gelatinous plankton is almost non-existent. Many fish

  2. A study on the Gut contents of six Leathery Turtles Dermochelys Coriacea (Linnaeus) (Reptilia: Testudines: Dermochelyidae) from British waters and from the Netherlands

    NARCIS (Netherlands)

    Hartog, den J.C.; Nierop, van M.M.

    1984-01-01

    Microscopical investigations of the gut contents of six individuals of Dermochelys coriacea from southern England and the North Sea revealed the presence in all of these of numerous nematocysts, mainly scyphozoan. Only six species of Scyphozoa occur in British shallow waters and in the North Sea, vi

  3. Multiple photoreceptor systems control the swim pacemaker activity in box jellyfish

    DEFF Research Database (Denmark)

    Garm, Anders Lydik; Mori, S.

    2009-01-01

    Like all other cnidarian medusae, box jellyfish propel themselves through the water by contracting their bell-shaped body in discrete swim pulses. These pulses are controlled by a swim pacemaker system situated in their sensory structures, the rhopalia. Each medusa has four rhopalia each with a s......Like all other cnidarian medusae, box jellyfish propel themselves through the water by contracting their bell-shaped body in discrete swim pulses. These pulses are controlled by a swim pacemaker system situated in their sensory structures, the rhopalia. Each medusa has four rhopalia each...

  4. 鹿児島湾に出現した多数のベニクラゲ(刺胞動物門, ヒドロ虫網, 花クラゲ目)とその若返りについて

    OpenAIRE

    築地新, 光子; 久保田, 信

    2003-01-01

    On Nov. 5, 2002 more than 200 medusae of Turritopsis nutricula (Hydrozoa, Anthomedusae, Clavidae) were collected in Kagoshima Bay. Most of them were well-grown or possibly mature, and they differ in some respects from conspecihc medusae from Kagoshima Bay described by Bigelow (1913) and also from T. nutricula in northern Japan. A description is given based on 10 larger specimens. One medusa could be parasitized by up to 100 or more trematodes. One out of 10 immature medusae with fewer than 30...

  5. Mitochondrial genome of the freshwater jellyfish Craspedacusta sowerbyi and phylogenetics of Medusozoa.

    Science.gov (United States)

    Zou, Hong; Zhang, Jin; Li, Wenxiang; Wu, Shangong; Wang, Guitang

    2012-01-01

    The 17,922 base pairs (bp) nucleotide sequence of the linear mitochondrial DNA (mtDNA) molecule of the freshwater jellyfish Craspedacusta sowerbyi (Hydrozoa, Trachylina, Limnomedusae) has been determined. This sequence exhibits surprisingly low A+T content (57.1%), containing genes for 13 energy pathway proteins, a small and a large subunit rRNAs, and methionine and tryptophan tRNAs. Mitochondrial ancestral medusozoan gene order (AMGO) was found in the C. sowerbyi, as those found in Cubaia aphrodite (Hydrozoa, Trachylina, Limnomedusae), discomedusan Scyphozoa and Staurozoa. The genes of C. sowerbyi mtDNA are arranged in two clusters with opposite transcriptional polarities, whereby transcription proceeds toward the ends of the DNA molecule. Identical inverted terminal repeats (ITRs) flank the ends of the mitochondrial DNA molecule, a characteristic typical of medusozoans. In addition, two open reading frames (ORFs) of 354 and 1611 bp in length were found downstream of the large subunit rRNA gene, similar to the two ORFs of ORF314 and polB discovered in the linear mtDNA of C. aphrodite, discomedusan Scyphozoa and Staurozoa. Phylogenetic analyses of C. sowerbyi and other cnidarians were carried out based on both nucleotide and inferred amino acid sequences of the 13 mitochondrial energy pathway genes. Our working hypothesis supports the monophyletic Medusozoa being a sister group to Octocorallia (Cnidaria, Anthozoa). Within Medusozoa, the phylogenetic analysis suggests that Staurozoa may be the earliest diverging class and the sister group of all other medusozoans. Cubozoa and coronate Scyphozoa form a clade that is the sister group of Hydrozoa plus discomedusan Scyphozoa. Hydrozoa is the sister group of discomedusan Scyphozoa. Semaeostomeae is a paraphyletic clade with Rhizostomeae, while Limnomedusae (Trachylina) is the sister group of hydroidolinans and may be the earliest diverging lineage among Hydrozoa.

  6. Mitochondrial genome of the freshwater jellyfish Craspedacusta sowerbyi and phylogenetics of Medusozoa.

    Directory of Open Access Journals (Sweden)

    Hong Zou

    Full Text Available The 17,922 base pairs (bp nucleotide sequence of the linear mitochondrial DNA (mtDNA molecule of the freshwater jellyfish Craspedacusta sowerbyi (Hydrozoa, Trachylina, Limnomedusae has been determined. This sequence exhibits surprisingly low A+T content (57.1%, containing genes for 13 energy pathway proteins, a small and a large subunit rRNAs, and methionine and tryptophan tRNAs. Mitochondrial ancestral medusozoan gene order (AMGO was found in the C. sowerbyi, as those found in Cubaia aphrodite (Hydrozoa, Trachylina, Limnomedusae, discomedusan Scyphozoa and Staurozoa. The genes of C. sowerbyi mtDNA are arranged in two clusters with opposite transcriptional polarities, whereby transcription proceeds toward the ends of the DNA molecule. Identical inverted terminal repeats (ITRs flank the ends of the mitochondrial DNA molecule, a characteristic typical of medusozoans. In addition, two open reading frames (ORFs of 354 and 1611 bp in length were found downstream of the large subunit rRNA gene, similar to the two ORFs of ORF314 and polB discovered in the linear mtDNA of C. aphrodite, discomedusan Scyphozoa and Staurozoa. Phylogenetic analyses of C. sowerbyi and other cnidarians were carried out based on both nucleotide and inferred amino acid sequences of the 13 mitochondrial energy pathway genes. Our working hypothesis supports the monophyletic Medusozoa being a sister group to Octocorallia (Cnidaria, Anthozoa. Within Medusozoa, the phylogenetic analysis suggests that Staurozoa may be the earliest diverging class and the sister group of all other medusozoans. Cubozoa and coronate Scyphozoa form a clade that is the sister group of Hydrozoa plus discomedusan Scyphozoa. Hydrozoa is the sister group of discomedusan Scyphozoa. Semaeostomeae is a paraphyletic clade with Rhizostomeae, while Limnomedusae (Trachylina is the sister group of hydroidolinans and may be the earliest diverging lineage among Hydrozoa.

  7. Nemopsis mianzani n. sp. (Hydrozoa, Bougainvilliidae), a new hydromedusa from central Chile.

    Science.gov (United States)

    Oliveira, Otto M P; Feliú, Guillermo; Palma, Sergio

    2015-07-24

    The genus Nemopsis, a bougainvillid hydrozoan with a dominant medusa phase, currently includes three species (Nemopsis bachei, N. dofleini and N. hexacanalis), all characterized by the presence of a pair of club-shaped tentacles in the median portion of the marginal bulbs. In this paper, we describe a fourth species, based on the medusa collected off Dichato, central Chilean coast.

  8. Is global ocean sprawl a cause of jellyfish blooms?

    OpenAIRE

    Duarte, Carlos M.; Pitt, Kylie A.; Lucas, C.H.; Purcell, Jennifer E.; Uye, Shin-Ichi; Robinson, Kelly L.; Brotz, Lucas; Decker, MaryBeth; Kelly R Sutherland; Malej, Alenka; Madin, Laurence P.; Mianzan, Hermes; Gili, Josep-Maria; Fuentes, Veronica; Atienza, D.

    2013-01-01

    Jellyfish (Cnidaria, Scyphozoa) blooms appear to be increasing in both intensity and frequency in many coastal areas worldwide, due to multiple hypothesized anthropogenic stressors. Here, we propose that the proliferation of artificial structures – associated with (1) the exponential growth in shipping, aquaculture, and other coastal industries, and (2) coastal protection (collectively, “ocean sprawl”) – provides habitat for jellyfish polyps and may be an important driver of the global increa...

  9. Morphological and ultrastructural analysis of Turritopsis nutricula during life cycle reversal.

    Science.gov (United States)

    Carla', E C; Pagliara, P; Piraino, S; Boero, F; Dini, L

    2003-06-01

    The hydrozoa life cycle is characterized, in normal conditions, by the alternation of a post-larval benthic polyp and an adult pelagic medusa; however, some species of Hydrozoa react to environmental stress by reverting their life cycle: i.e. an adult medusa goes back to the juvenile stage of polyp. This very uncommon life cycle could be considered as some sort of inverted metamorphosis. A morphological study of different stages during the reverted life cycle of Turritopsis nutricula led to the characterization of four different stages: healthy medusa, unhealthy medusa, four-leaf clover and cyst. The ultrastructural study of the cellular modifications (during the life cycle reversion of T. nutricula) showed the presence of both degenerative and apoptotic processes. Degeneration was prevalent during the unhealthy medusa and four-leaf clover stages, while the apoptotic rate was higher during the healthy medusa and cyst stages. The significant presence of degenerative and apoptotic processes could be related to the occurrence of a sort of metamorphosis when an adult medusa transforms itself into a polyp.

  10. Optimization of Purification Technique Conditions of Fruiting Body Polysaccharide of H. caput-medusae (Bull. Fr. ) Pets. using Salting-out Method%盐析法纯化猴头菌多糖工艺条件的研究

    Institute of Scientific and Technical Information of China (English)

    孙文怡; 战阳; 郝锡联; 宋慧

    2011-01-01

    The experiment was conducted by using response surface methodology to optimize purification of fruiting body polysaccharide. The main testing elements and levels are chosen based on experiment of single factor. Response surface methodology of three factors and three levels was adopted on the rationale of Box-benhnken design of experiment. The influencing factors for every technological condition were also obtained through regression analysis. Also the response surface and contour were drawn out with the removal rate of protein in crude polysaccharide content as criteria. Through the analysis of the distinctiveness and interactions between various factors, the results showed that the condition for eliminating proteins from polysaccharide by salting-out method is: pH 5.01, Saturation of ammonium sulfate 41%, concentration 4 %.%利用响应面法对猴头菌子实体的纯化工艺进行优化.在单因素试验基础上选取主要的试验因素与水平,根据中心组合(Box-Benhnken)试验设计原理采用三因素三水平的响应面分析法,依据回归分析确定各工艺条件的影响因素,以粗多糖中的蛋白去除率为指标响应值作响应面和等高线.在分析各个因素的显著性和交互作用后,得出利用硫酸铵法去除多糖中杂蛋白的条件为:pH值为5.01,硫酸铵饱和度为41%,溶液浓度为4%.

  11. 'Medusa head ataxia': the expanding spectrum of Purkinje cell antibodies in autoimmune cerebellar ataxia. Part 3: Anti-Yo/CDR2, anti-Nb/AP3B2, PCA-2, anti-Tr/DNER, other antibodies, diagnostic pitfalls, summary and outlook

    National Research Council Canada - National Science Library

    Jarius, S; Wildemann, B

    2015-01-01

    Serological testing for anti-neural autoantibodies is important in patients presenting with idiopathic cerebellar ataxia, since these autoantibodies may indicate cancer, determine treatment and predict prognosis...

  12. Goplers relative trofiske niveau bestemt ved δ15N

    DEFF Research Database (Denmark)

    Christensen, Jens Tang; Sode, Sidsel; Krawack, Marie-Louise

    , hvor den indbyrdes afstand mellem to arter er bestemt på samme tid og i samme vandmasse. I laboratorieforsøg har Aurelia vist lave værdier for trofisk berigelse (forskel på fødens og Aurelias 15N) på 0,74 ‰ for Artemia, 0,99 ‰ for Brachionus og 0,58 ‰ for skrubbelarver. Dette bør undersøges i flere...... forsøg, men giver dog et sammenligningsgrundlag for prøver taget i havet. I seks hav-prøvetagninger lå Cyanea capillata 0,21-2,28 ‰ over Aurelia i 15N, mens Aurelia i en syvende prøvetagning lå 0,86 ‰ over Cyanea (forskel dog ikke signifikant). I tre prøvetagninger lå Mnemiopsis leidyi 0,01-1,61 ‰ over...... Aurelia i 15N mens Mnemiopsis lå 0,29 ‰ over Cyanea capillata i én sammenligning, mens den lå 1,72 ‰ over Cyanea lamarcki i en anden prøvetagning. I tre prøvetagninger lå Pleurobrachia pileus 1,74-4,18 ‰ over Aurelia i 15N og 1,06-2,51 ‰ over Cyanea capillata. Generelt synes ribbegoplerne at ligge på et...

  13. Jellyfish stings

    Science.gov (United States)

    ... The World of Medusa and Her Sisters. 2016. Springer. Wilcox CL, Yanagihara AA. Heated debates: Hot-water ... medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- ...

  14. Occurrence of swarms of Sagitta enflata (Chaetognatha) and Pleurobrachia globosa (Ctenophora) in the coastal waters of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    Swarms of Chaetognatha @iSagitta enflata@@ Grassi and Ctenophore @iPleurobrachia globosa@@. Moser were studied in coastal waters of Goa. These two forms together constituted 90 to 94% of total biomass. Medusae and Siphonophora were the other main...

  15. Molecular characterization of aspartylglucosaminidase, a lysosomal hydrolase upregulated during strobilation in the moon jellyfish, Aurelia aurita.

    Science.gov (United States)

    Tsujita, Natsumi; Kuwahara, Hiroyuki; Koyama, Hiroki; Yanaka, Noriyuki; Arakawa, Kenji; Kuniyoshi, Hisato

    2017-05-01

    The life cycle of the moon jellyfish, Aurelia aurita, alternates between a benthic asexual polyp stage and a planktonic sexual medusa (jellyfish) stage. Transition from polyp to medusa is called strobilation. To investigate the molecular mechanisms of strobilation, we screened for genes that are upregulated during strobilation using the differential display method and we identified aspartylglucosaminidase (AGA), which encodes a lysosomal hydrolase. Similar to AGAs from other species, Aurelia AGA possessed an N-terminal signal peptide and potential N-glycosylation sites. The genomic region of Aurelia AGA was approximately 9.8 kb in length and contained 12 exons and 11 introns. Quantitative RT-PCR analysis revealed that AGA expression increased during strobilation, and was then decreased in medusae. To inhibit AGA function, we administered the lysosomal acidification inhibitors, chloroquine or bafilomycin A1, to animals during strobilation. Both inhibitors disturbed medusa morphogenesis at the oral end, suggesting involvement of lysosomal hydrolases in strobilation.

  16. The polyps of Oceania armata identified by DNA barcoding (Cnidaria, Hydrozoa).

    Science.gov (United States)

    Schuchert, Peter

    2016-10-18

    The polyps of the widely distributed medusa Oceania armata have never been found in nature and only the primary polyp is known from breeding experiments. The fully developed colony is so far unknown. This report shows that DNA sequence data of the medusa stage of O. armata permits to identify several hydroid colonies from different geographic origins as the most likely polyp stage of this medusa. These hydroids had previously been misidentified as Turritopsis species, a closely related genus which also produces medusae resembling Oceania armata. It is concluded that most Turritopsis hydroids are not reliably identifiable to species level using morphological traits only. However, DNA barcodes, particularly 16S sequences, are an excellent tool to identify the species, although we still lack information on a few nominal species and the identities of some sequence-delimited clades need to be corroborated by the addition of topotype samples.

  17. A new record of the freshwater jellyfish Craspedacusta sowerbii Lankester, 1880 (Hydrozoa) in Southeastern Anatolia (Turkey)

    Science.gov (United States)

    Bekleyen, Aysel; Varol, Memet; Gokot, Bulent

    2011-03-01

    We report the first record of the invasive freshwater jellyfish Craspedacusta sowerbii Lankester in Kralkizi Dam Lake, Southeastern Anatolia, Turkey. The medusa was found only in August, 2008 when average surface water temperatures were 26.9°C.

  18. A new record of the freshwater jellyfish Craspedacusta sowerbii Lankester, 1880 (Hydrozoa) in Southeastern Anatolia (Turkey)

    Institute of Scientific and Technical Information of China (English)

    Aysel BEKLEYEN; Memet VAROL; Bulent GOKOT

    2011-01-01

    We report the first record of the invasive freshwater jellyfish Craspedacusta sowerbii Lankester in Kralkizi Dam Lake, Southeastern Anatolia, Turkey. The medusa was found only in August, 2008 when average surface water temperatures were 26.9℃.

  19. Clearance rates of jellyfish and their potential predation impact on zooplankton and fish larvae in a neritic ecosystem (Limfjorden, Denmark)

    DEFF Research Database (Denmark)

    Hansson, L. J.; Moeslund, O.; Kiørboe, Thomas

    2005-01-01

    comparatively low. These data were used to assess the impact of jellyfish predation upon zooplankton and fish larvae in Limfjorden, Denmark. Repeated sampling of zooplankton, fish larvae and medusae was undertaken during the first half of 2003. Nine taxa of hydromedusae and 4 taxa of scyphomedusae were...... identified. Abundance estimates were combined with estimated clearance rates of individual medusae to calculate potential jellyfish-induced mortality on prey in Limfjorden. Copepoda was used as a model prey group to estimate the collective predation impact by all medusae. Medusa species with unknown...... clearance potential were given assumed clearance rate values, but the collective predation potential by these species was evaluated to be small. Hydromedusae dominated numerically and had their highest potential clearance impact in spring, but overall jellyfish clearance potential on copepods was low during...

  20. Optimal hash arrangement of tentacles in jellyfish

    Science.gov (United States)

    Okabe, Takuya; Yoshimura, Jin

    2016-06-01

    At first glance, the trailing tentacles of a jellyfish appear to be randomly arranged. However, close examination of medusae has revealed that the arrangement and developmental order of the tentacles obey a mathematical rule. Here, we show that medusa jellyfish adopt the best strategy to achieve the most uniform distribution of a variable number of tentacles. The observed order of tentacles is a real-world example of an optimal hashing algorithm known as Fibonacci hashing in computer science.

  1. 退化しないクラゲ口柄基部より走根を伸張しポリプに若返ったベニクラゲ(ヒドロ虫綱, 花クラゲ目)の成熟雄

    OpenAIRE

    久保田, 信

    2005-01-01

    A mature male medusa (small morphotype) of Turritopsis nutricula McCrady collected on 18 August 2005 from Tanabe Bay, Wakayama Prefecture, Japan, transformed to the young polyp stage after partial degeneration of the medusa body, by extension of stolons from the base of the undegenerated manubrium, which retains the ability to engulf and digest food (Anemia nauplii). Such a reversion, retaining part of the old body (the manubrium) attached to the new body (the polyp colony), is the first such...

  2. Proterodiplostome Parasites (Digenea, Proterodiplostomidae of the Caiman, Caiman crocodilus yacare (Reptilia, Crocodylia in the Pantanal mato-Grossense, Brazil, with the description of two new species

    Directory of Open Access Journals (Sweden)

    João B. Catto

    1994-12-01

    Full Text Available Two new species are described from the caiman. Caiman crocodilus yacare. Proterodiplostomum breve n. sp. differs from all other species in the genus by the following chacacteristics: (1 the paraprostate gland is shorter and club-shaped; (2 the genital cone is, in average, eight times longer than that of P. medusae; (3 the genital atrium is larger and without pseudosuckers; (4 the oral sucker and pharynx are longer; and (5 there are larger numbers of papillae surrounding the tribocytic organ (40 against 20 in P. longum, 16 in p. tumidilum, 8 in P. ophidum, and 16-18 in P. medusae. Proterodiplostomum globulare n. sp. differs from all the other species in the fenus by the following characteristics: (1 from P. tumidilum, P. lomgum, P. medusae, and P. breve n. sp. for the absense of pseudosuckers or muscular bunches in the inferior wall of the genital atrium; (2 the shape of the paraprostate gland, which is globular and not cylindrical as in P. longum, P. tumidilum, P. medusae, and P. ophidum; (3 the size of the tribocytic organ 201-407 long, 183-495 wide, while is 138-270 long, 102-292 wide in P. medusae, and 138-270 long, 255 wide in P. ophidum; (4 the number of papillae in the tribocytic organ (18-20 in P. globulare and 16-18 in P. medusae, and 8 in P. ophidum. Specimens belonging to six other species of proterodiplostomes are recorded for the first time infecting the caiman, C. c. yacare in the Pantanal Mato-grossense, Brazil, namely: Proterodiplostomum medusae, P. tumidilum, Cystodiplostomum hollyi, Prolecithodiplostomum constrictum, Paradiplostomum abbreviatum, and Herpetodiplostomum caimancola.

  3. Jumping across biomedical contexts using compressive data fusion

    Science.gov (United States)

    Zitnik, Marinka; Zupan, Blaz

    2016-01-01

    Motivation: The rapid growth of diverse biological data allows us to consider interactions between a variety of objects, such as genes, chemicals, molecular signatures, diseases, pathways and environmental exposures. Often, any pair of objects—such as a gene and a disease—can be related in different ways, for example, directly via gene–disease associations or indirectly via functional annotations, chemicals and pathways. Different ways of relating these objects carry different semantic meanings. However, traditional methods disregard these semantics and thus cannot fully exploit their value in data modeling. Results: We present Medusa, an approach to detect size-k modules of objects that, taken together, appear most significant to another set of objects. Medusa operates on large-scale collections of heterogeneous datasets and explicitly distinguishes between diverse data semantics. It advances research along two dimensions: it builds on collective matrix factorization to derive different semantics, and it formulates the growing of the modules as a submodular optimization program. Medusa is flexible in choosing or combining semantic meanings and provides theoretical guarantees about detection quality. In a systematic study on 310 complex diseases, we show the effectiveness of Medusa in associating genes with diseases and detecting disease modules. We demonstrate that in predicting gene–disease associations Medusa compares favorably to methods that ignore diverse semantic meanings. We find that the utility of different semantics depends on disease categories and that, overall, Medusa recovers disease modules more accurately when combining different semantics. Availability and implementation: Source code is at http://github.com/marinkaz/medusa Contact: marinka@cs.stanford.edu, blaz.zupan@fri.uni-lj.si PMID:27307649

  4. Low power proximity electronics for dust analysers based on light scattering

    Science.gov (United States)

    Molfese, C.; Esposito, F.; Cortecchia, F.; Cozzolino, F.

    2012-04-01

    The present paper focuses on the development of an optimized version of the Proximity Electronics (PE) for dust analysers based on static light scattering. This kind of instruments, aimed to the systematic measurement of the size of dust grains in Martian atmosphere, was developed by the Cosmic Physics and Planetology Group at the INAF Astronomical Observatory of Capodimonte (OAC) and University Parthenope (LFC group), in Naples, Italy. One of these instruments, the MEDUSA Experiment, was selected for the Humboldt Payload of the ExoMars mission, the first mission to Mars of the ESA Aurora Programme. Thereafter, this mission was revised because of increasing costs and lack of funds and the MEDUSA experiment has been completely re-engineered to meet more demanding constraints of mass and power consumption. The dust analyser under development is named MicroMED, as it is a lighter and more compact version of MEDUSA. MicroMED is provided with an Optical System (OS) based on the same concept of the one present in MEDUSA, but with a low power PE and low power laser source. This paper reports the features and the tests results of three versions of low power PE developed for MicroMED, and also compares two basic approaches, one based on a linear amplifier, derived from the solution implemented in two different MEDUSA breadboards (B/Bs), and the other one based on a logarithmic amplifier, with better performance in terms of compactness and low power consumption.

  5. Population succession and feeding of scyphomedusae, Aurelia aurita, in a eutrophic tropical lagoon in Taiwan

    Science.gov (United States)

    Lo, W. T.; Chen, I. L.

    2008-01-01

    Seasonal dynamics and feeding of scyphomedusae, Aurelia aurita, were investigated monthly from 1999 to 2002 in relation to environmental conditions in Tapong Bay, a eutrophic tropical lagoon in southwestern Taiwan. Medusae appeared throughout the year but exhibited seasonal dynamics that were correlated with hydrographic features in the bay. Most ephyrae of A. aurita occurred mainly in the lower flushed and eutrophic inner bay, and during the cold, dry season between November and February. They grew to young medusae with a maximum abundance in spring (March-May), but their numbers abruptly decreased during the warm and rainy summer season in June-September. The remaining medusae then grew rapidly to a maximal size of 29 cm. Mature females spawned in the following autumn when precipitation decreased but zooplankton food was still abundant. These mature individuals decreased in size after spawning and in winter. Gut content analysis revealed that A. aurita fed mainly on copepods and copepod nauplii and less on bivalve larvae and fish eggs. Prey selectivity indices indicated that larger medusae selected positively for copepods while small size medusae preferred copepod nauplii. The overall feeding effect of A. aurita on the standing stock of zooplankton was significant (27%) in the bay. Our results suggest that tidal flow and dense oyster culture pens were the two most important factors influencing the spatial distribution pattern of A. aurita in the bay, while precipitation affected the population abundance seasonally; decreasing water temperature coincided with the mass release of ephyra in late autumn and winter.

  6. DNA barcodes unite two problematic taxa: the meiobenthic Boreohydra simplex is a life-cycle stage of Plotocnide borealis (Hydrozoa: Aplanulata).

    Science.gov (United States)

    Pyataeva, Sofia V; Hopcroft, Russell R; Lindsay, Dhugal J; Collins, Allen G

    2016-08-10

    Genetic barcodes of arctic medusae and meiobenthic cnidarians have uncovered a fortuitous connection between the medusa Plotocnide borealis Wagner, 1885 and the minute, mud-dwelling polyp Boreohydra simplex Westblad, 1937. Little to no sequence differences exist among independently collected samples identified as Boreohydra simplex and Plotocnide borealis, showing that the two different forms represent a single species that is henceforth known by the older name Plotocnide borealis Wagner, 1885. The polyp form has been observed to produce bulges previously hypothesized to be gonophores, and the results here are consistent with that view. Interestingly, the polyp has also been reported to produce egg cells in the epiderm, a surprising phenomenon that we document here for only the second time. Thus, P. borealis produces eggs in two different life stages, polyp and medusa. This is the first documented case of a metagenetic medusozoan species being able to produce gametes in both the medusa and polyp stage. It remains unclear what environmental/ecological conditions modulate the production of eggs and/or medusa buds in the polyp stage. Similarly, sperm production, fertilization and development are unknown, warranting further studies.

  7. Protective effects of batimastat against hemorrhagic injuries in delayed jellyfish envenomation syndrome models.

    Science.gov (United States)

    Wang, Beilei; Liu, Dan; Liu, Guoyan; Zhang, Xin; Wang, Qianqian; Zheng, Jiemin; Zhou, Yonghong; He, Qian; Zhang, Liming

    2015-12-15

    Previously, we established delayed jellyfish envenomation syndrome (DJES) models and proposed that the hemorrhagic toxins in jellyfish tentacle extracts (TE) play a significant role in the liver and kidney injuries of the experimental model. Further, we also demonstrated that metalloproteinases are the central toxic components of the jellyfish Cyanea capillata (C. capillata), which may be responsible for the hemorrhagic effects. Thus, metalloproteinase inhibitors appear to be a promising therapeutic alternative for the treatment of hemorrhagic injuries in DJES. In this study, we examined the metalloproteinase activity of TE from the jellyfish C. capillata using zymography analyses. Our results confirmed that TE possessed a metalloproteinase activity, which was also sensitive to heat. Then, we tested the effect of metalloproteinase inhibitor batimastat (BB-94) on TE-induced hemorrhagic injuries in DJES models. Firstly, using SR-based X-ray microangiography, we found that BB-94 significantly improved TE-induced hepatic and renal microvasculature alterations in DJES mouse model. Secondly, under synchrotron radiation micro-computed tomography (SR-μCT), we also confirmed that BB-94 reduced TE-induced hepatic and renal microvasculature changes in DJES rat model. In addition, being consistent with the imaging results, histopathological and terminal deoxynucleotidyl transferase-mediated UTP end labeling (TUNEL)-like staining observations also clearly corroborated this hypothesis, as BB-94 was highly effective in neutralizing TE-induced extensive hemorrhage and necrosis in DJES rat model. Although it may require further clinical studies in the near future, the current study opens up the possibilities for the use of the metalloproteinase inhibitor, BB-94, in the treatment of multiple organ hemorrhagic injuries in DJES.

  8. Community Characters and Sand Trapping Capability of Three Common Species of Psammophyte in Yanchi County, Ningxia%宁夏盐池县3种常见沙生植物群落特征及阻沙能力

    Institute of Scientific and Technical Information of China (English)

    贾丽娜; 吴斌; 丁国栋; 张宇清; 王翔宇

    2009-01-01

    植物形态对其阻沙能力大小具有重要意义.通过对盐池县3种常见沙生植物猫头刺(Oxytropis aciphylla Ledeb)、米蒿(Artemisia dalai-lamae Krasch)和针茅(Stipa capillata Linn)的野外调查,分析了3种3沙生植物群落的主要形态参数与沙舌长度和拦沙面积的相关关系及与其阻沙能力的拟合关系.结果表明:3种沙生植物群落主要形态参数分别与沙舌长度和拦沙面积呈显著相关,猫头刺、米蒿和针茅的高度与拦沙面积相关系数分别为0.759、0.793、0.988,而冠幅宽度和长度与拦沙面积相关系数均达到0.9以上;猫头刺和针茅的拦沙面积和沙舌长度都随着冠幅面积和植株高度的增加呈线性增加,而米蒿则呈幂指数增加,且猫头刺的阻沙能力大于针茅和米蒿.%The correlations between main morphological parameters of psammophyte communities and sand tongue length, sedi-ment retention area were analyzed through a field investigation of three common shrubs in Yanchi County, Ningxia. And then the fitting relationship between the main morphological parameters and the sand trapping capability was discussed. Result showed that the main morphological parameters of psammophyte communities were significantly correlated with sand tongue length and sediment retention area. The correlation coefficients of height and sediment retention area for Oxytropis aciphylla Ledeb, Artemisia dalai-lamae Krasch and Stipa capillata Linn were 0.759, 0.793, 0.988, respectively, and the correlation coefficients of crown width, crown length and sediment retention area were all more than 0.9. The sediment re-tention area and sand tongue length for 0. aciphylla and S. capillata increased linearly with crown area and plant height, and those for A. dalai-lamae increased exponentially. The sand trapping capability of 0. aciphylla is better than that of S. capillata and A. dalai-lamae.

  9. Character evolution in Hydrozoa (phylum Cnidaria).

    Science.gov (United States)

    Cartwright, Paulyn; Nawrocki, Annalise M

    2010-09-01

    The diversity of hydrozoan life cycles, as manifested in the wide range of polyp, colony, and medusa morphologies, has been appreciated for centuries. Unraveling the complex history of characters involved in this diversity is critical for understanding the processes driving hydrozoan evolution. In this study, we use a phylogenetic approach to investigate the evolution of morphological characters in Hydrozoa. A molecular phylogeny is reconstructed using ribosomal DNA sequence data. Several characters involving polyp, colony, and medusa morphology are coded in the terminal taxa. These characters are mapped onto the phylogeny and then the ancestral character states are reconstructed. This study confirms the complex evolutionary history of hydrozoan morphological characters. Many of the characters involving polyp, colony, and medusa morphology appear as synapomorphies for major hydrozoan clades, yet homoplasy is commonplace. © The Author 2010. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved.

  10. The elusive life cycle of scyphozoan jellyfish - metagenesis revisited

    Science.gov (United States)

    Ceh, Janja; Gonzalez, Jorge; Pacheco, Aldo S.; Riascos, José M.

    2015-07-01

    Massive proliferations of scyphozoan jellyfish considerably affect human industries and irreversibly change food webs. Efforts to understand the role of jellyfish in marine ecosystems are based on a life cycle model described 200 years ago. According to this paradigm the pelagic medusae is considered seasonal and alternates with the benthic polyp stage from which it derives. However, we provide evidence that a) the occurrence of several species of medusae is not restricted to a season in the year, they overwinter, b) polyp- and medusa generations are neither temporally nor spatially separated, and c) “metagenesis” which is defined as the alternation between sexual and asexual generations does not always occur. Hence we recommend additions to the current model and argue that the scyphozoan life cycle should be considered multi-modal, rather than metagenetic. The implications of these findings for jellyfish proliferations, including possible consequences and associated environmental drivers, are discussed.

  11. The elusive life cycle of scyphozoan jellyfish--metagenesis revisited.

    Science.gov (United States)

    Ceh, Janja; Gonzalez, Jorge; Pacheco, Aldo S; Riascos, José M

    2015-07-08

    Massive proliferations of scyphozoan jellyfish considerably affect human industries and irreversibly change food webs. Efforts to understand the role of jellyfish in marine ecosystems are based on a life cycle model described 200 years ago. According to this paradigm the pelagic medusae is considered seasonal and alternates with the benthic polyp stage from which it derives. However, we provide evidence that a) the occurrence of several species of medusae is not restricted to a season in the year, they overwinter, b) polyp- and medusa generations are neither temporally nor spatially separated, and c) "metagenesis" which is defined as the alternation between sexual and asexual generations does not always occur. Hence we recommend additions to the current model and argue that the scyphozoan life cycle should be considered multi-modal, rather than metagenetic. The implications of these findings for jellyfish proliferations, including possible consequences and associated environmental drivers, are discussed.

  12. Molecular phylogenetics of Thecata (Hydrozoa, Cnidaria) reveals long-term maintenance of life history traits despite high frequency of recent character changes.

    Science.gov (United States)

    Leclère, Lucas; Schuchert, Peter; Cruaud, Corinne; Couloux, Arnaud; Manuel, Michael

    2009-10-01

    Two fundamental life cycle types are recognized among hydrozoan cnidarians, the benthic (generally colonial) polyp stage either producing pelagic sexual medusae or directly releasing gametes elaborated from an attached gonophore. The existence of intermediate forms, with polyps producing simple medusoids, has been classically considered compelling evidence in favor of phyletic gradualism. In order to gain insights about the evolution of hydrozoan life history traits, we inferred phylogenetic relationships of 142 species of Thecata (= Leptothecata, Leptomedusae), the most species-rich hydrozoan group, using 3 different ribosomal RNA markers (16S, 18S, and 28S). In conflict with morphology-derived classifications, most thecate species fell in 2 well-supported clades named here Statocysta and Macrocolonia. We inferred many independent medusa losses among Statocysta. Several instances of secondary regain of medusoids (but not of full medusa) from medusa-less ancestors were supported among Macrocolonia. Furthermore, life cycle character changes were significantly correlated with changes affecting colony shape. For both traits, changes did not reflect graded and progressive loss or gain of complexity. They were concentrated in recent branches, with intermediate character states being relatively short lived at a large evolutionary scale. This punctuational pattern supports the existence of 2 alternative stable evolutionary strategies: simple stolonal colonies with medusae (the ancestral strategy, seen in most Statocysta species) versus large complex colonies with fixed gonophores (the derived strategy, seen in most Macrocolonia species). Hypotheses of species selection are proposed to explain the apparent long-term stability of these life history traits despite a high frequency of character change. Notably, maintenance of the medusa across geological time in Statocysta might be due to higher extinction rates for species that have lost this dispersive stage.

  13. Multiple factors affect pest and pathogen damage on 31 Populus clones in South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Coyle, David R.; Coleman, Mark D. [USDA Forest Service, Southern Research Station, P.O. Box 700, New Ellenton, SC 29809 (United States); Durant, Jaclin A.; Newman, Lee A. [Arnold School of Public Health, Department of Environmental Health Sciences, University of South Carolina, 800 Sumter St., Columbia, SC 29208 (United States)

    2006-08-15

    Populus species and hybrids have many practical applications, but there is a paucity of data regarding selections that perform well in the southeastern US. We compared pest susceptibility of 31 Populus clones over 3 years in South Carolina, USA. Cuttings were planted in spring 2001 on two study sites. Clones planted in the bottomland site received granular fertilizer yearly and irrigation the first two years only, while those on the sandy, upland site received irrigation and fertilization throughout each growing season. Foliar damage by the cottonwood leaf beetle (Chrysomela scripta), cottonwood leafcurl mite (Tetra lobulifera), and poplar leaf rust (Melampsora medusae) was visually monitored several times each growing season. Damage ratings differed significantly among clones, and clonal rankings changed from year to year. Irrigation increased C. scripta and M. medusae damage, but had no effect on T. lobulifera damage. Certain clones received greater pest damage at a particular study site. Temporal damage patterns were evident among individual clones and on each site. At the upland site, OP367 and 7300502 were highly resistant to all three pests; I45/51 was highly resistant to C. scripta and M. medusae; NM6 and 15-29 were highly resistant to M. medusae; and 7302801 was highly resistant to T. lobulifera and M. medusae. At the bottomland site, NM6, Eridano, I45/51, and 7302801 were highly resistant to all three pests; clone 7300502 was highly resistant to M. medusae only. Based on this preliminary 3-year study of pest damage levels, we would recommend clones NM6, Eridano, I45/51, OP367, 15-29, 7302801, 7300502, and Kentucky 8 for use in this region. (author)

  14. Muscle and nerve net organization in stalked jellyfish (Medusozoa: Staurozoa).

    Science.gov (United States)

    Westlake, Hannah E; Page, Louise R

    2017-01-01

    Staurozoan cnidarians display an unusual combination of polyp and medusa characteristics and their morphology may be informative about the evolutionary origin of medusae. We studied neuromuscular morphology of two staurozoans, Haliclystus 'sanjuanensis' and Manania handi, using whole mount immunohistochemistry with antibodies against FMRFamide and α-tubulin to label neurons and phalloidin to label muscles. All muscles appeared to lack striations. Longitudinal interradial muscles are probable homologues of stalk muscles in scyphopolyps, but in adult staurozoans they are elaborated to inwardly flex marginal lobes of the calyx during prey capture; these muscles are pennate in M. handi. Manubrial perradial muscles, like the manubrium itself, are an innovation shared with pelagic medusae and manubrial interradial muscles are shared with scyphozoan ephyra. Marginal muscles of M. handi displayed occasional synchronous contraction reminiscent of a medusa swim pulse, but contractions were not repetitive. The nerve net in both species showed regional variation in density and orientation of neurons. Some areas labeled predominantly by α-tubulin antibodies (exumbrellar epidermis), other areas labeled exclusively by FMRFamide antibodies (dense plexus of neurites surrounding the base of secondary tentacles, neuronal concentration at the base of transformed primary tentacles; gastrodermal nerve net), but most areas showed a mix of neurons labeled by these two antibodies and frequent co-labeling of neurons. Transformed primary tentacles had a concentration of FMRFamide-immunoreactive neurons at their base that was associated with a pigment spot in M. handi; this is consistent with their homology with rhopalia of medusae, which are also derived from primary tentacles. The muscular system of these staurozoans embodies characteristics of both scyphopolyps and pelagic medusae. However, their nerve net is more polyp-like, although marginal concentrations of the net associated with

  15. Population Dynamics of Jellyfish Aurelia aurita (s.l. in Sihwa Lake

    Directory of Open Access Journals (Sweden)

    Hyun-pyo Hong

    2013-09-01

    Full Text Available We investigated the population dynamics of Aurelia aurita in Sihwa Lake from April to October in 2009. Salinity ranged from 5.9 to 30.7 psu at the surface. Abundance of mesozooplankton ranged from 3 to 111,874 indiv. m−3. Ephyrae occurred from April to May with the peak in abundance occurring on 17 April. Maximum density of ephyrae was observed near the power transmission towers that are known to be habitats of polyps. Mortality of ephyrae was lower than in other areas because of the abundant prey concentration and the absence of predators. Young medusae occurred from April to July with the peak in abundance occurring on 8 May. Adult medusae occurred from May to July with the peak in abundance on 25 June and they disappeared before the rainy season. Planula occurred only in May and June with the peak in abundance on 25 June. Growth rates of Aurelia aurita ranged from −0.06 to 0.34 d−1, and decreased rapidly after May. The period in which adult medusa occurred was restricted, compared with those in other area in Korea (e.g., Masan Bay and Japan (e.g., Tokyo Bay. In the period of this study, the available food was limited in June and salinity decreased to ca. 20 psu in May because of the beginning of the wet season. We assumed that the exceptionally short period of occurrence of the medusa may be a response of adults to changes in temperature, salinity or food limitation which leads to the precocious maturation of young medusa and the release of planula and that the brief occurrence of medusa was caused by an abrupt decrease in activity after the release of planula.

  16. El mito de Perseo en los mosaicos hispanorromanos : particularidades hispanas

    OpenAIRE

    Guadalupe López Monteagudo

    1998-01-01

    Análisis iconográfico de las distintas fases del mito de Perseo en ios mosaicos romanos, siguiendo las fuentes literarias - Dánae recibiendo la lluvia de oro, llegada de Dánae con el niño Perseo a las costas de Seripfios, Perseo dando muerte a la medusa volviendo la cabeza al escudo de Atfienea, llegada del tiéroe volando ai lugar donde se fiallaba expuesta Andrómeda, Perseo vencedor de la medusa y del kethos, Perseo contemplando a Andrómeda encadenada a la roca, el gorgoneion en el centro de...

  17. A new record of Craspedacusta sowerbii, Lankester 1880 (Cnidaria, Limnomedusae in Northern Italy

    Directory of Open Access Journals (Sweden)

    Alessandro MARIENI

    2010-02-01

    Full Text Available A new record of the freshwater jellyfish Craspedacusta sowerbii in Northern Italy is reported. The medusae bloom occurred in a small oligo-mesotrophic artificial lake during July, 2009. At the time of sampling, the medusae were all immature, reached low density and showed feeding preference towards the Daphnia complex of species, the most abundant zooplanktonic species in the lake. Negative feeding selectivity towards small Rotifera was demonstrated. The occasional occurrence of a C. sowerbii bloom in this lake suggests the distribution range of this species may be largely underestimated, and its potential impact on the zooplankton community remains unknown.

  18. Shaping the Department’s S&T Strategy

    Science.gov (United States)

    2011-06-21

    for public release; distribution is unlimited. Sea Tracker JCTD Nat’l Tech Nuclear Forensics JCTD MEDUSA JCTD July 12 Imperatives 1. Accelerate...21/2011 Page-11 Distribution Statement A: Approved for public release; distribution is unlimited. DoD S&T Funding By Budget Activity - President’s

  19. Seeding medusahead-invaded rangeland following mechanical disturbance on the channeled scablands of eastern Washington

    Science.gov (United States)

    Vegetation on the Channeled Scablands of eastern Washington has been altered to a medusahead-lupine dominated landscape. Medusahead (Taeniatherum caput-medusae [L.] Nevski) is seldom utilized by livestock, decreases carrying capacity, and can lead to the consumption of poisonous plants. Velvet lupin...

  20. Automated multidimensional image analysis reveals a role for Abl in embryonic wound repair.

    Science.gov (United States)

    Zulueta-Coarasa, Teresa; Tamada, Masako; Lee, Eun J; Fernandez-Gonzalez, Rodrigo

    2014-07-01

    The embryonic epidermis displays a remarkable ability to repair wounds rapidly. Embryonic wound repair is driven by the evolutionary conserved redistribution of cytoskeletal and junctional proteins around the wound. Drosophila has emerged as a model to screen for factors implicated in wound closure. However, genetic screens have been limited by the use of manual analysis methods. We introduce MEDUSA, a novel image-analysis tool for the automated quantification of multicellular and molecular dynamics from time-lapse confocal microscopy data. We validate MEDUSA by quantifying wound closure in Drosophila embryos, and we show that the results of our automated analysis are comparable to analysis by manual delineation and tracking of the wounds, while significantly reducing the processing time. We demonstrate that MEDUSA can also be applied to the investigation of cellular behaviors in three and four dimensions. Using MEDUSA, we find that the conserved nonreceptor tyrosine kinase Abelson (Abl) contributes to rapid embryonic wound closure. We demonstrate that Abl plays a role in the organization of filamentous actin and the redistribution of the junctional protein β-catenin at the wound margin during embryonic wound repair. Finally, we discuss different models for the role of Abl in the regulation of actin architecture and adhesion dynamics at the wound margin.

  1. Thermal and Osmotic Tolerance of 'Irukandji' Polyps: Cubozoa; Carukia barnesi.

    Directory of Open Access Journals (Sweden)

    Robert Courtney

    Full Text Available This research explores the thermal and osmotic tolerance of the polyp stage of the Irukandji jellyfish Carukia barnesi, which provides new insights into potential polyp habitat suitability. The research also targets temperature, salinity, feeding frequency, and combinations thereof, as cues for synchronous medusae production. Primary findings revealed 100% survivorship in osmotic treatments between 19 and 46‰, with the highest proliferation at 26‰. As salinity levels of 26‰ do not occur within the waters of the Great Barrier Reef or Coral Sea, we conclude that the polyp stage of C. barnesi is probably found in estuarine environments, where these lower salinity conditions commonly occur, in comparison to the medusa stage, which is oceanic. Population stability was achieved at temperatures between 18 and 31°C, with an optimum temperature of 22.9°C. We surmise that C. barnesi polyps may be restricted to warmer estuarine areas where water temperatures do not drop below 18°C. Asexual reproduction was also positively correlated with feeding frequency. Temperature, salinity, feeding frequency, and combinations thereof did not induce medusae production, suggesting that this species may use a different cue, possibly photoperiod, to initiate medusae production.

  2. Ecology, genetics, and biological control of invasive annual grasses in the Great Basin

    Science.gov (United States)

    Several annual grass species native to Eurasia, including cheatgrass (Bromus tectorum), red brome (B. rubens), and medusahead (Taeniatherum caput-medusae) have become invasive in the western USA. These invasive species degrade rangelands by compromising forage, outcompeting native flora, and exacerb...

  3. An inter-comparison of sediment classification methods based on multi-beam echo-sounder backscatter and sediment natural radioactivity data.

    Science.gov (United States)

    Snellen, Mirjam; Eleftherakis, Dimitrios; Amiri-Simkooei, Alireza; Koomans, Ronald L; Simons, Dick G

    2013-08-01

    This contribution presents sediment classification results derived from different sources of data collected at the Dordtse Kil river, the Netherlands. The first source is a multi-beam echo-sounder (MBES). The second source is measurements taken with a gamma-ray scintillation detector, i.e., the Multi-Element Detection System for Underwater Sediment Activity (Medusa), towed over the sediments and measuring sediment natural radioactivity. Two analysis methods are employed for sediment classification based on the MBES data. The first is a Bayesian estimation method that uses the average backscatter data per beam and, therefore, is independent of the quality of the MBES calibration. The second is a model-based method that matches the measured backscatter curves to theoretical curves, predicted by a physics-based model. Medusa provides estimates for the concentrations of potassium, uranium, thorium, and cesium, known to be indicative for sediment properties, viz. mean grain size, silt content, and the presence of organic matter. In addition, a hydrophone attached to the Medusa system provides information regarding the sediment roughness. This paper presents an inter-comparison between the sediment classification results using the above-mentioned methods. It is shown that although originating from completely different sources, the MBES and Medusa provide similar information, revealing the same sediment distribution.

  4. Dicty_cDB: Contig-U13541-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 4e-73 AY466445_1( AY466445 |pid:none) Macrobrachium rosenbergii heat sho... 237 5e-73 AB206478_1( AB206478 ...1( AY836799 |pid:none) Saussurea medusa heat shock protei... 231 8e-73 DQ660140_1( DQ660140 |pid:none) Macrobrachium

  5. Sex determination and differentiation in Aurelia sp.1: the absence of temperature dependence

    Science.gov (United States)

    Liu, Chunsheng; Gu, Zhifeng; Xing, Mengxin; Sun, Yun; Chen, Siqing; Chen, Zhaoting

    2017-03-01

    Cnidarians, being regarded as `basal' metazoan animals, are considered to have relatively high plasticity in terms of sex reversal. In this study we used an experimental approach to demonstrate sexual differentiation and plasticity in benthic polyps and pelagic medusae of Aurelia sp.1 maintained at different temperatures. Results indicated that in Aurelia sp.1, sex differentiation has been determined at the polyp stage and that all medusae originating from a given polyp are, phenotypically, of the same sex. In addition, the sex of polyps budding from the same clone (either male or female) at different temperatures appears to be the same as that of the parent. The sex of medusae that had originated from a known-sex polyp was observed to remain the same as that of the parent, irrespective of differences in strobilation or rearing temperatures. These results indicate that the mechanism of sex determination of Aurelia sp.1. is not influenced by prevailing temperature regimes. A comparison of variability in terms of sexual plasticity of Aurelia sp.1 with that of Hydrozoa and Anthozoa suggests that species characterized by a free-swimming medusa life stage have a high dispersal potential, which probably results in a lower rate of sex reversal.

  6. Concentration and toxicity of some metals in zooplankton from nearshore waters of Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Gajbhiye, S.N.; Nair, V.R.; Narvekar, P.V.; Desai, B.N.

    in zooplankton collected from all stations. Bioassay tests were carried out for evaluating the acute toxicity of Cu and Ni on selected groups of zooplankton. Cu was more toxic than Ni. Among the different organisms tested Sagitta, Lucifer, Ctenophores and Medusae...

  7. Margelopsis gibbesii (McCrady, 1859) (Cnidaria, Hydrozoa): taxonomic review, and conservation of usage by designation of a lectotype.

    Science.gov (United States)

    Calder, Dale R; Johnson, William S

    2015-12-02

    The binomen Nemopsis gibbesii McCrady, 1859, originally applied to a species of hydromedusa and its supposed hydroid from South Carolina, USA, has been known for more than a century to encompass two species. The medusa stage is conspecific with that of Nemopsis bachei L. Agassiz, 1849, while the hydroid stage is referable to the genus Margelopsis Hartlaub, 1897. Both that hydroid, and the medusa stage now subjectively linked to it, are commonly assigned to M. gibbesii. With no type having ever been designated for McCrady's species, a lectotype is designated to stabilize nomenclature of the species and serve as the standard for application of the name. In the absence of type specimens, an illustration of the hydroid of N. gibbesii by McCrady is chosen as lectotype, thereby conserving the name Margelopsis gibbesii in its accustomed usage. Hydroids and medusae of the species are re-described from new material, the cnidome of both stages is characterized, and a taxonomic review is given. The hydroid stage is reported for the first time since its original description in the mid-19th century. Medusae of M. gibbesii are also seen infrequently, having been reported only six times earlier.

  8. Thermal and Osmotic Tolerance of ‘Irukandji’ Polyps: Cubozoa; Carukia barnesi

    Science.gov (United States)

    Courtney, Robert; Browning, Sally; Northfield, Tobin; Seymour, Jamie

    2016-01-01

    This research explores the thermal and osmotic tolerance of the polyp stage of the Irukandji jellyfish Carukia barnesi, which provides new insights into potential polyp habitat suitability. The research also targets temperature, salinity, feeding frequency, and combinations thereof, as cues for synchronous medusae production. Primary findings revealed 100% survivorship in osmotic treatments between 19 and 46‰, with the highest proliferation at 26‰. As salinity levels of 26‰ do not occur within the waters of the Great Barrier Reef or Coral Sea, we conclude that the polyp stage of C. barnesi is probably found in estuarine environments, where these lower salinity conditions commonly occur, in comparison to the medusa stage, which is oceanic. Population stability was achieved at temperatures between 18 and 31°C, with an optimum temperature of 22.9°C. We surmise that C. barnesi polyps may be restricted to warmer estuarine areas where water temperatures do not drop below 18°C. Asexual reproduction was also positively correlated with feeding frequency. Temperature, salinity, feeding frequency, and combinations thereof did not induce medusae production, suggesting that this species may use a different cue, possibly photoperiod, to initiate medusae production. PMID:27441693

  9. Life in tidepools: distribution and abundance of two crawling hydromedusae, Staurocladia oahuensis and S. bilateralis, on a rocky intertidal shore in Kominato, central Japan

    Directory of Open Access Journals (Sweden)

    Yayoi M. Hirano

    2000-12-01

    Full Text Available Two crawling medusae, Staurocladia oahuensis (Edmondson, 1930 and S. bilateralis (Edmondson, 1930 were found to be abundant in intertidal rock pools in Kominato from late summer until early winter. The two species were found to rarely share the same individual alga, and sometimes showed exclusive occupancy of pools at higher intertidal levels. The abundance of the two species of medusae fluctuated widely over time with both species showing similar population structures during their period of occurrence. The asexual reproduction of the medusae was considered to be a cause of the distributional pattern and the fluctuation in abundance. An experiment was conducted to evaluate the rate of asexual reproduction under different conditions. At 12°C neither species performed asexual reproduction, while at 17°C and higher temperatures both species reproduced asexually at a high rate. The number of each population was found to nearly double in about a week. The coexistence of the two species of medusae in tidepools is discussed in relation to the habitat characteristics. S. oahuensis and S. bilateralis were not known previously from Japan; this constitutes a new record of both species from Japanese waters. We also found both species in several other warm water locations in Japan.

  10. Thomson Scattering Process in Laser-Produced Plasmas

    Institute of Scientific and Technical Information of China (English)

    YU Quan-Zhi; JIANG Xiao-Hua; LI Wen-Hong; LIU Shen-Ye; ZHENG Zhi-Jian; ZHANG Jie; LI Yu-Tong; ZHENG Jun; YAN Fei; LU Xin; WANG Zhe-Bin; ZHENG Jian; YU Chang-Xuan

    2005-01-01

    @@ We present the evolutions of the electron temperature and plasma expansion velocity with Thomson scattering experiment. The observed time-resolved ion-acoustic image is reproduced by a numerical code which couples the Thomson scattering theory with the output parameters of the one-dimensional hydrocode MEDUSA.

  11. Multi-dimensional free-electron laser simulation codes: a comparison study

    CERN Document Server

    Biedron, S G; Dejus, Roger J; Faatz, B; Freund, H P; Milton, S V; Nuhn, H D; Reiche, S

    2000-01-01

    A self-amplified spontaneous emission (SASE) free-electron laser (FEL) is under construction at the Advanced Photon Source (APS). Five FEL simulation codes were used in the design phase: GENESIS, GINGER, MEDUSA, RON, and TDA3D. Initial comparisons between each of these independent formulations show good agreement for the parameters of the APS SASE FEL.

  12. Life history and population dynamics of Moerisia sp., a non-native hydrozoan, in the upper San Francisco Estuary (U.S.A.)

    Science.gov (United States)

    Wintzer, Alpa P.; Meek, Mariah H.; Moyle, Peter B.

    2011-07-01

    Some populations of gelatinous zooplankton appear to be increasing and causing ecological disruptions during large bloom events. The goal of this study was to investigate the life history and population dynamics of the small, invasive Moerisia sp. and its potential ecological impacts in the upper San Francisco Estuary, California. Medusae and polyps were collected from 8 and 2 sites, respectively, during 2007 and 2008. Polyps emerged from a resting stage during June. Asexual reproduction of medusae buds was positively correlated with temperature and negatively related to salinity. The production of polyp buds was positively correlated with dissolved oxygen and water transparency levels. Sexual reproduction, defined by the presence of eggs, was related to the size of medusae. Cessation of reproduction of both polyps and medusae occurred in October, when temperatures dropped below 17 °C. This life history is similar to other hydrozoans and allows Moerisia sp. to reach large numbers seasonally in the San Francisco Estuary, possibly contributing to the recent declines of pelagic fish and zooplankton.

  13. Simulation of the fundamental and nonlinear harmonic output from an FEL amplifier with a soft x-ray seed laser

    Energy Technology Data Exchange (ETDEWEB)

    Biedron, S. G.; Freund, H. P.; Li, Y.; Milton, S. V.

    2000-07-05

    A single-pass, high-gain free-electron laser (FEL) x-ray amplifier was simulated using the 3D, polychromatic simulation code MEDUSA. The seed for the system is a table-top, soft x-ray laser. The simulated fundamental and nonlinear harmonic x-ray output wavelengths are discussed.

  14. A method for in situ estimation of prey selectivity and predation rate in large plankton, exemplified with the jellyfish Aurelia aurita (L.)

    DEFF Research Database (Denmark)

    Hansson, L.J.

    2006-01-01

    among individual jellyfish and among the various oral arms and gastric pouches within individuals. Clearance rates varied strongly with prey type. The medusae selected large crustacean prey (cladocerans and copepods/copepodites) over echinoderm larvae and copepod nauplii. Prey distribution within...

  15. Weed-suppressive bacteria to reduce annual grass weeds

    Science.gov (United States)

    Cheatgrass (Bromus tectorum L.), medusahead (Taeniatherum caput-medusae [L.] Nevski) and jointed goatgrass (Aegilops cylindrica L.) are exotic, annual grasses that negatively affect cereal production in cropland; reduce protein-rich forage for cattle; choke out native plants in the shrub-steppe habi...

  16. Ostroumovia inkermanica in the Netherlands

    NARCIS (Netherlands)

    Saraber, J.G.A.M.

    1962-01-01

    During an examination of the Hydromedusae from the Netherlands and adjacent waters present in the collections of the Rijksmuseum van Natuurlijke Historie at Leiden, the Zoological Museum at Amsterdam, and the Zoological Station at Den Helder, some specimens of a medusa were found that proved to belo

  17. Gclust Server: 201739 [Gclust Server

    Lifescience Database Archive (English)

    Full Text Available 201739 NCR_NCU07617 Cluster Sequences - 692 hypothetical protein similar to develop...mental regulator medusa (translation) (693 aa); no annotation 1 1.00e-99 0.0 0.0 0.0 0.0 0.0 12.5 Show 201739 Cluster ID 2017

  18. Army Logistician. Volume 39, Issue 6, November-December 2007

    Science.gov (United States)

    2007-12-01

    Storage and Distribution Center —Second Lieutenant Carlos E. Comas 42 Joint Asset Visibility: Why So Hard? Commercial Sector Information...possesses the ability to project and forecast needs at the tactical level. This attribute became evident during Operation Medusa, the North...Considerations Studying lessons learned, planning, and coordinat- ing serve as crucial tools for forecasting unit require- ments. When forecasting

  19. Pattern- and contrast-dependent visual response in the box jellyfish Tripedalia cystophora

    DEFF Research Database (Denmark)

    Garm, Anders; Hedal, Ida; Islin, Majken

    2013-01-01

    Cubomedusae possess a total of 24 eyes, some of which are structurally similar to vertebrate eyes. Accordingly, the medusae also display a range of light-guided behaviours including obstacle avoidance, diurnal activity patterns and navigation. Navigation is supported by spatial resolution and ima...

  20. Teaching Art with Art: Grotesque Visions.

    Science.gov (United States)

    Hubbard, Guy

    2001-01-01

    Discusses a type of visual art called grotesque art and includes four different examples of grotesque art: (1) the painting "Head of Medusa" by Peter Paul Rubens; (2) Rangda, the widow witch from Bali (Indonesia); (3) totem poles; and (4) grotesque sculptures from the Cathedral of Notre Dame (Paris, France). (CMK)

  1. Embryonic development and metamorphosis of the scyphozoan Aurelia.

    Science.gov (United States)

    Yuan, David; Nakanishi, Nagayasu; Jacobs, David K; Hartenstein, Volker

    2008-10-01

    We investigated the development of Aurelia (Cnidaria, Scyphozoa) during embryogenesis and metamorphosis into a polyp, using antibody markers combined with confocal and transmission electron microscopy. Early embryos form actively proliferating coeloblastulae. Invagination is observed during gastrulation. In the planula, (1) the ectoderm is pseudostratified with densely packed nuclei arranged in a superficial and a deep stratum, (2) the aboral pole consists of elongated ectodermal cells with basally located nuclei forming an apical organ, which is previously only known from anthozoan planulae, (3) endodermal cells are large and highly vacuolated, and (4) FMRFamide-immunoreactive nerve cells are found exclusively in the ectoderm of the aboral region. During metamorphosis into a polyp, cells in the planula endoderm, but not in the ectoderm, become strongly caspase 3 immunoreactive, suggesting that the planula endoderm, in part or in its entirety, undergoes apoptosis during metamorphosis. The polyp endoderm seems to be derived from the planula ectoderm in Aurelia, implicating the occurrence of "secondary" gastrulation during early metamorphosis.

  2. Metabolism measurements of Aurelia aurita planulae larvae, and calculation of maximal survival period of the free swimming stage

    Science.gov (United States)

    Schneider, G.; Weisse, T.

    1985-03-01

    Respiration, ammonia and phosphate excretion experiments were performed with planula larvae of Aurelia aurita (Scyphozoa) from Kiel Fjord, Baltic Sea, in summer 1983. The mean respiration measured was 3.22 nl O2 ind-1 h-1 (at ˜ 20 °C). Excretion experiments revealed average values of 11.41 pM NH4-N ind-1, and 0.92 pM PO4-P ind-1h-1, respectively. The atomic C:N:P ratio of excretion products was 133:10:1. The O:N ratio of 25:1 and O:P ratio of 313:1 point to a lipid-carbohydrate-oriented catabolism of the Aurelia larvae. On the basis of experimental results and of biomass determinations, the maximal survival period of the non-feeding free swimming planula stage was calculated. Typically, the value lies in the range of some days to one week.

  3. 海月水母培育初报

    Institute of Scientific and Technical Information of China (English)

    陈介康

    1986-01-01

    海月水母(Aurelia aurita)是广泛分布于世界各海区的一种大型水母,成体伞径一般为100—200毫米。国内外生物学教科书中,几乎均以海月水母作为腔肠动物门(Coelenterata)、钵水母纲(Scyphozoa)的代表。它是生物学教学和科研的良好实验材料,也可作为水簇馆的观赏动物。国内尚未见有对海月水母培育的报道。有关大专院校和科研单位一般都无这种水母的无性世代标本。

  4. Catostylus tagi: partial rDNA sequencing and characterisation of nematocyte structures using two improvements in jellyfish sample preparation.

    Science.gov (United States)

    Parracho, Tiago; Morais, Zilda

    2015-01-01

    More than 200 Scyphozoa species have been described, but few have been properly studied regarding their chemical and genetic characteristics. Catostylus tagi, an edible Scyphozoa and the sole European Catostylidae, occurs in summer at Tagus and Sado estuaries. Neither a systematic comparison between the two Catostylus communities nor a chemical approach on their nematocytes had been carried out yet. In order to achieve these purposes, optimisation of DNA extraction and of histochemical staining procedures were developed. Catostylus specimens from Tagus and Sado estuaries were compared by ribosomal 18S, 28S, and ITS1 partial sequencing. The morphochemistry of nematocytes was studied by optical and electronic microscopy. Macroscopic and molecular results indicated that both communities belong to the same species, C. tagi. The hematoxylin and eosin staining allowed the visualisation of nematocyst genesis and indicated a basic character for the macromolecules on the shaft of euryteles and on the tubule of isorhizae and birhopaloids. By Masson's trichrome procedure, the basic properties of the tubules were confirmed and a collagenous profile for the toxins was suggested. Results of the alcian blue staining showed that the outer membrane of nematocyte may consist of macromolecules with acidic polysaccharides, consistent with NOWA and nematogalectin glycoproteins detected in Hydra, but also with poly-gamma-glutamate complex, chitin-like polysaccharides and hyaluronic acids. Through the von Kossa assays, calcium was detected; its position suggested interactions with polysaccharides of the membrane, with proteins of the contractile system or with both. The optimisation of sample preparation for DNA extraction may facilitate further studies on little known jellyfish species. The improvement of the smear procedure simplified the use of stained reactions in zooplankton. Moreover, it was shown that good slide images might be acquired manually. The development of specific

  5. New data on the stem and leaf anatomy of two conifers from the Lower Cretaceous of the Araripe Basin, northeastern Brazil, and their taxonomic and paleoecological implications

    Science.gov (United States)

    Batista, Maria Edenilce Peixoto; Silva, Delmira da Costa; Sales, Marcos A. F.; Sá, Artur A.; Saraiva, Antônio A. F.; Loiola, Maria Iracema Bezerra

    2017-01-01

    Pseudofrenelopsis and Brachyphyllum are two conifers that were part of the Lower Cretaceous (Aptian) taphoflora of the Crato Formation, Araripe Basin, northeastern Brazil. The former genus includes, so far, P. capillata and indeterminate species, whilst the latter is mainly represented by B. obesum, the most common plant megafossil recovered from that stratigraphic unit. Here, the stem and leaf anatomy of Pseudofrenelopsis sp. and B. obesum specimens is revisited, including the first report of some epidermal and vascular traits for both taxa from the Crato Formation. Along with its paleoecological significance, the new data suggest the presence of more than one Pseudofrenelopsis species in the Aptian taphoflora of the Araripe Basin and further support the taxonomic placement of B. obesum within Araucariaceae. PMID:28257466

  6. CLASTS OF UPPERMOST ALBIAN (VRACONIAN LIMESTONE IN THE EOCENE CUCCURU 'E FLORES CONGLOMERATE OF THE M. ALBO MASSIF (EASTERN SARDINIA

    Directory of Open Access Journals (Sweden)

    IGINIO DIENI

    2012-03-01

    Full Text Available Rare clasts of richly fossiliferous uppermost Albian (Vraconian auctt. glauconitic and phosphatic, ammonite-bearing limestone have been found in the Eocene Cuccuru ’e Flores Conglomerate in the area of M. Albo massif (eastern Sardinia. The limestone is wholly comparable in facies and fossil assemblage to the classical outcrop known in the Orosei area. The fossil content includes also brachiopods and abundant planktonic foraminifers of the Thalmanninella (formerly Rotalipora appenninica Zone. In the palaeontological part the brachiopods Orbirhynchia parkinsoni and Capillithyris capillata are described and discussed. Vraconian highly condensed deposits, characterized by basal erosional gaps of variable importance, have particular relevance, being known to be widely distributed in the northern Tethyan margin with common characteristics, such as authigenic glauconite, phosphatic nodules and a rich outer-shelf fauna. 

  7. The value of small habitat islands for the conservation of genetic variability in a steppe grass species

    Science.gov (United States)

    Wódkiewicz, Maciej; Dembicz, Iwona; Moysiyenko, Ivan I.

    2016-10-01

    The habitat loss and fragmentation due to agricultural land-conversion affected the steppe throughout its range. In Ukraine, 95% of steppe was destroyed in the last two centuries. Remaining populations are confined to few refuges, like nature reserves, loess ravines, and kurgans (small burial mounds), the latter being often subject to destruction by archeological excavations. Stipa capillata L. is a typical grass species of Eurasian steppes and extrazonal dry grasslands, that was previously used as a model species in studies on steppe ecology. The aim of our research was to assess genetic diversity of S. capillata populations within different types of steppe refuges (loess ravines, biosphere reserve, kurgan) and to evaluate the value of the latter group for the preservation of genetic diversity in the study species. We assessed genetic diversity of 266 individuals from 15 populations (nine from kurgans, three from loess ravines and three from Askania-Nova Biosphere Reserve) with eight Universal Rice Primers (URPs). Studied populations showed high intra-population variability (I: 0.262-0.419, PPB: 52.08-82.64%). Populations from kurgans showed higher genetic differentiation (ΦST = 0.247) than those from loess ravines (ΦST = 0.120) and the biosphere reserve (ΦST = 0.142). Although the diversity metrics were to a small extent lower for populations from kurgans than from larger refugia we conclude that all studied populations of the species still preserve high genetic variability and are valuable for protection. To what extent this pattern holds true under continuous fragmentation in the future must be carefully monitored.

  8. Not all jellyfish are equal: isotopic evidence for inter- and intraspecific variation in jellyfish trophic ecology

    Directory of Open Access Journals (Sweden)

    Nicholas E.C. Fleming

    2015-07-01

    Full Text Available Jellyfish are highly topical within studies of pelagic food-webs and there is a growing realisation that their role is more complex than once thought. Efforts being made to include jellyfish within fisheries and ecosystem models are an important step forward, but our present understanding of their underlying trophic ecology can lead to their oversimplification in these models. Gelatinous zooplankton represent a polyphyletic assemblage spanning >2,000 species that inhabit coastal seas to the deep-ocean and employ a wide variety of foraging strategies. Despite this diversity, many contemporary modelling approaches include jellyfish as a single functional group feeding at one or two trophic levels at most. Recent reviews have drawn attention to this issue and highlighted the need for improved communication between biologists and theoreticians if this problem is to be overcome. We used stable isotopes to investigate the trophic ecology of three co-occurring scyphozoan jellyfish species (Aurelia aurita, Cyanea lamarckii and C. capillata within a temperate, coastal food-web in the NE Atlantic. Using information on individual size, time of year and δ13C and δ15N stable isotope values, we examined: (1 whether all jellyfish could be considered as a single functional group, or showed distinct inter-specific differences in trophic ecology; (2 Were size-based shifts in trophic position, found previously in A. aurita, a common trait across species?; (3 When considered collectively, did the trophic position of three sympatric species remain constant over time? Differences in δ15N (trophic position were evident between all three species, with size-based and temporal shifts in δ15N apparent in A. aurita and C. capillata. The isotopic niche width for all species combined increased throughout the season, reflecting temporal shifts in trophic position and seasonal succession in these gelatinous species. Taken together, these findings support previous

  9. Endobiotic bacteria and their pathogenic potential in cnidarian tentacles

    Science.gov (United States)

    Schuett, Christian; Doepke, Hilke

    2010-09-01

    Endobiotic bacteria colonize the tentacles of cnidaria. This paper provides first insight into the bacterial spectrum and its potential of pathogenic activities inside four cnidarian species. Sample material originating from Scottish waters comprises the jellyfish species Cyanea capillata and C. lamarckii, hydrozoa Tubularia indivisa and sea anemone Sagartia elegans. Mixed cultures of endobiotic bacteria, pure cultures selected on basis of haemolysis, but also lyophilized samples were prepared from tentacles and used for DGGE-profiling with subsequent phylogenetic analysis of 16S rDNA fragments. Bacteria were detected in each of the cnidarian species tested. Twenty-one bacterial species including four groups of closely related organisms were found in culture material. The species within these groups could not be differentiated from each other (one group of Pseudoalteromonas spp., two groups of Shewanella spp., one group of Vibrio spp.). Each of the hosts exhibits a specific endobacterial spectrum. Solely Cyanea lamarckii harboured Moritella viscosa. Only in Cyanea capillata, members of the Shewanella group #2 and the species Pseudoalteromonas arctica, Shewanella violacea, Sulfitobacter pontiacus and Arcobacter butzleri were detected. Hydrozoa Tubularia indivisa provided an amazingly wide spectrum of nine bacterial species. Exclusively, in the sea anemone Sagartia elegans, the bacterial species P. aliena was found. Overall eleven bacterial species detected were described recently as novel species. Four 16S rDNA fragments generated from lyophilized material displayed extremely low relationship to their next neighbours. These organisms are regarded as members of the endobiotic “terra incognita”. Since the origin of cnidarian toxins is unclear, the possible pathogenic activity of endobiotic bacteria has to be taken into account. Literature data show that their next neighbours display an interesting diversity of haemolytic, septicaemic and necrotic actions including

  10. UN ANÁLISIS DE LAS ACTIVIDADES DIDÁCTICAS CON TIC EN AULAS DE EDUCACIÓN SECUNDARIA

    Directory of Open Access Journals (Sweden)

    M. Area

    2011-01-01

    Full Text Available Este artículo se basa en un estudio de casos desarrollado en dos centros de Educación Secundaria de Tenerife integrados en el Proyecto Medusa del Gobierno de Canarias http://www.gobiernodecanarias.org/ educacion/medusa. Se presentan aquí los resultados obtenidos de las observaciones de diversas clases cuyo objetivo central fue identificar qué tipo de actividades didácticas se han desarrollado con las TIC, en qué medida estas actividades están favoreciendo la adquisición de competencias informacionales y digitales en el alumnado, y cómo se han organizado y desarrollado las mismas en el contexto del aula.

  11. El plancton del Atlántico suroeste: dinamica y ecología

    Directory of Open Access Journals (Sweden)

    Angeles Alvariño

    1980-12-01

    Full Text Available Plankton was collected in Nov.-Dec. 1972, during the Cato-6 Expedition (R/VMelville. Distribution of Siphonophores and Medusae and ecological implications pointed out by these organisms are discussea. 25 species of Siphonophorae were obtained corresponding to tropical, temperate, and Antarctic Subantarctic categories. 5 species of Medusae appeared , showing the peculiar erratic distribution typical of these organisms. Faunistic data are presented in tables and maps. Effects of Brazil, Falkland Currents and upwelling, centers appear well defined by the distribution of the siphonophores. Cosmopolitan siphonophores, typical of temperate and warm waters inhabited a band (zone of Rio Grande rise between the southernmost and northernmost progressions of Brazil and Falkland Currents. These populations are carried toward South-american coasts by the anticyclonic circulation of the Central South Atlantic, forming a convergence; and a divergence towards the north is responsible for development of upwelling systems

  12. Abundance, growth and food demand of the scyphomedusa Aurelia aurita in the western Wadden Sea

    Science.gov (United States)

    van der Veer, H. W.; Oorthuysen, W.

    Medusae of Aurelia aurita are found in the western Wadden Sea from the beginning of May till August with maximum numbers of 250 to 500 individuals per 10 3 m 3 during May-June. The existence of a continuous ebb surplus suggests an origin from polyps living in the inner parts of the estuary and a transport or migration of the released medusae towards the North Sea. Growth is fast; a bell size of 20 cm diameter is reached within 3 to 4 months. The species is important as a predator from May to July, reaching maximum carbon biomass values of 12 to 18 g C·10 3 m -3. Predation by A. aurita may affect the recruitment of one of its food sources, viz. fish larvae.

  13. Podocoryna loyola, n. sp. (Hydrozoa, Hydractiniidae): a probably introduced species on artificial substrate from southern Brazil.

    Science.gov (United States)

    Haddad, Maria Angélica; Bettim, Ariane Lima; Miglietta, Maria Pia

    2014-05-20

    Podocoryna loyola, a new hydractiniid species, has been found on artificial substrates in Baía de Paranaguá, southern coast of Brazil, since April 2007. Its main morphological characteristics are: (1) polymorphic colonies with reticular stolons or encrusting hydrorhiza not covered by periderm and smooth chitinous spines; (2) newly-released medusae with eight tentacles and small interradial gonads; (3) mature medusae with eight tentacles and unbranched oral lips; gastric peduncle absent. Molecular data show that P. loyola is distinct from all other examined species of Podocoryna, and from P. hayamaensis Hirohito (1988), its sister species from Japan. As the polyps having been noted only quite recently, and in having been found only on man-made objects in port areas and estuaries, the species is most likely exotic to the region.

  14. First record of Craspedacusta sowerbii Lankester, 1880 (Hydrozoa, Limnomedusae) in a natural freshwater lagoon of Uruguay, with notes on polyp stage in captivity.

    Science.gov (United States)

    Siquier, M G Failla; Alanis, W S Serra; Debat, C Martinez

    2017-05-04

    The freshwater cnidarian Craspedacusta sowerbii Lankester 1880, has invaded lakes and ponds as well as artificial water bodies throughout the world. The first record in Uruguay corresponding to the jellyfish was made in 1961 in two artificial fountains, with no mention of the polyp form. Although local reports of other related polyp species have been made, information on the benthic form of C. sowerbii is lacking. Here we report the finding of live frustules, solitary individuals, medusae and colonies from a natural lagoon in August 2010, allowing us to observe the morphology and behavior of the polyp stage in captivity. In addition, molecular identification and remarks on the potencial path of introduction are presented. This is the first record in Uruguay of both polyp and medusa stages of C. sowerbii in a natural water body, Del Medio Lagoon (Dpto. de Florida), Uruguay.

  15. Freshwater jellyfish Craspedacusta sowerbyi Lankester, 1880 (Hydrozoa, Olindiidae: 50 years' observations in Serbia

    Directory of Open Access Journals (Sweden)

    Jakovčev-Todorović Dunja

    2010-01-01

    Full Text Available Detailed and relevant limnological investigations of Serbian waters were initiated in 1958 and have continued to the present. During the period 1971-2008 we monitored biological elements as a part of working studies/projects, including the distribution of the freshwater jellyfish Craspedacusta sowerbyi Lankester, 1880. We observed over 500 sampling sites in running and standing waters. Specimens of this hydro-medusa were found in five of them. Throughout the period of investigation, only the medusae stages were observed. Our purpose in this paper was to provide data of the records and distribution of this limnomedusa during the period 1958-2008 in inland waters of Serbia. These observations should contribute to knowledge on the limnofauna not only of the Balkan Peninsula but Europe as a whole.

  16. Deciphering the Galaxy Guppy phenotype

    Directory of Open Access Journals (Sweden)

    Philip Shaddock

    2011-01-01

    Full Text Available Animal breeding hobbyists have been useful to science because they identify and isolate colorcoat mutations that geneticists can in turn use in their studies of the development and differentiation ofcolor cells. This paper discusses a very interesting color mutant, the Japanese Galaxy, tracing its creationfrom back to a self-educated genetics hobbyist, Hoskiki Tsutsui. The paper discusses a constituent genepreviously studied by Dr. Violet Phang, the snakeskin gene (the linked body and fin genes Ssb and Sst.And it discusses a gene previously unknown to science, the Schimmelpfennig Platinum gene (Sc.Through crossing experiments, the author determines that the combination of these two genes producesan intermediate phenotype, the Medusa. Incorporating the Grass (Gr, another gene unknown to sciencegene into the Medusa through a crossover produces the Galaxy phenotype. Microscope studies of thesnakeskin pattern in Galaxies and snakeskins reveals some parallels with similar studies made of theZebrafish Danio.

  17. Propulsion in cubomedusae: mechanisms and utility.

    Science.gov (United States)

    Colin, Sean P; Costello, John H; Katija, Kakani; Seymour, Jamie; Kiefer, Kristen

    2013-01-01

    Evolutionary constraints which limit the forces produced during bell contractions of medusae affect the overall medusan morphospace such that jet propulsion is limited to only small medusae. Cubomedusae, which often possess large prolate bells and are thought to swim via jet propulsion, appear to violate the theoretical constraints which determine the medusan morphospace. To examine propulsion by cubomedusae, we quantified size related changes in wake dynamics, bell shape, swimming and turning kinematics of two species of cubomedusae, Chironex fleckeri and Chiropsella bronzie. During growth, these cubomedusae transitioned from using jet propulsion at smaller sizes to a rowing-jetting hybrid mode of propulsion at larger sizes. Simple modifications in the flexibility and kinematics of their velarium appeared to be sufficient to alter their propulsive mode. Turning occurs during both bell contraction and expansion and is achieved by generating asymmetric vortex structures during both stages of the swimming cycle. Swimming characteristics were considered in conjunction with the unique foraging strategy used by cubomedusae.

  18. Warburg, Shakespeare e la prima impresa

    Directory of Open Access Journals (Sweden)

    Alice Barale

    2012-12-01

    Full Text Available With his fight against the sea monster Medusa, Perseus embodies for Warburg the “world-directed energy”. Warburg's “energetic  aesthetics” could be interpreted then as nothing but another version of the hypertrophic, despotic subject Ferraris has often written about. We will show it that is not the case by considering the relationship that Warburg draws between Perseus and Hamlet.

  19. Venous infraction of developmental venous anomaly: A case report with perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Youn; Kim, Hye Jeong; Hyun, Su Jeong; Kim, Hee Yeong; Kim, Han Myun; Hwang, Ji Young; Hong, Hye Suk; Woo, Ji Young; Yang, Ik [Dept. of Radiology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul (Korea, Republic of); Kim, Eun Soo [Dept. of Radiology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang (Korea, Republic of)

    2017-06-15

    Developmental venous anomaly (DVA) is a common congenital venous malformation characterized by dilated medullary veins in caput medusa configuration and a draining vein. Despite the high incidence of DVAs, they are benign anatomic variations and rarely cause symptoms. Here, we report computed tomography and magnetic resonance imaging findings with perfusion images of acute infarction from underlying DVA in a 63-year-old female patient who presented with acute onset of neurologic symptoms and recovered without any neurologic deficit.

  20. Transcriptome profiling of the dynamic life cycle of the scypohozoan jellyfish Aurelia aurita.

    Science.gov (United States)

    Brekhman, Vera; Malik, Assaf; Haas, Brian; Sher, Noa; Lotan, Tamar

    2015-02-14

    The moon jellyfish Aurelia aurita is a widespread scyphozoan species that forms large seasonal blooms. Here we provide the first comprehensive view of the entire complex life of the Aurelia Red Sea strain by employing transcriptomic profiling of each stage from planula to mature medusa. A de novo transcriptome was assembled from Illumina RNA-Seq data generated from six stages throughout the Aurelia life cycle. Transcript expression profiling yielded clusters of annotated transcripts with functions related to each specific life-cycle stage. Free-swimming planulae were found highly enriched for functions related to cilia and microtubules, and the drastic morphogenetic process undergone by the planula while establishing the future body of the polyp may be mediated by specifically expressed Wnt ligands. Specific transcripts related to sensory functions were found in the strobila and the ephyra, whereas extracellular matrix functions were enriched in the medusa due to high expression of transcripts such as collagen, fibrillin and laminin, presumably involved in mesoglea development. The CL390-like gene, suggested to act as a strobilation hormone, was also highly expressed in the advanced strobila of the Red Sea species, and in the medusa stage we identified betaine-homocysteine methyltransferase, an enzyme that may play an important part in maintaining equilibrium of the medusa's bell. Finally, we identified the transcription factors participating in the Aurelia life-cycle and found that 70% of these 487 identified transcription factors were expressed in a developmental-stage-specific manner. This study provides the first scyphozoan transcriptome covering the entire developmental trajectory of the life cycle of Aurelia. It highlights the importance of numerous stage-specific transcription factors in driving morphological and functional changes throughout this complex metamorphosis, and is expected to be a valuable resource to the community.

  1. The Cheshire Jet: Harnessing Metamaterials to Achieve an Optical Stealth Capability

    Science.gov (United States)

    2010-07-01

    mythology , and popular culture worldwide. Interestingly enough, it is usually villains and our enemies that we imbue with this ability. Perhaps no...history. Is this scenario mere science fiction, or is it reality wait- ing to happen? Humans have always dreamed of the power of invisibility. In Greek ... mythology , the hero Perseus used an enchanted helmet to disappear, allowing him to ap- proach unnoticed and slay the Gorgon Medusa.1 Invisibility

  2. Spatial and Temporal Variability of Zooplankton Thin Layers: The Effects of Composition and Orientation on Acoustic Detection of Layers

    Science.gov (United States)

    2010-09-30

    influencing the frequency dependent backscatter from the organisms. In particular, the orientations of the plankton relative to the acoustic source...zooplankton. We saw many images that contained multiple copepods and delicate gelatinous taxa such as larvaceans and medusae (Figures 7 and 8). Images of...WHOI) and “Finescale planktonic vertical structure: horizontal extent and the controlling physical processes” (N00014-04-10277), awarded to Tim

  3. Biomass of scyphozoan jellyfish, and its spatial association with 0-group fish in the Barents Sea.

    Science.gov (United States)

    Eriksen, Elena; Prozorkevich, Dmitry; Trofimov, Aleksandr; Howell, Daniel

    2012-01-01

    An 0-group fish survey is conducted annually in the Barents Sea in order to estimate fish population abundance. Data on jellyfish by-catch have been recorded since 1980, although this dataset has never been analysed. In recent years, however, the ecological importance of jellyfish medusae has become widely recognized. In this paper the biomass of jellyfish (medusae) in 0-60 m depths is calculated for the period 1980-2010. During this period the climate changed from cold to warm, and changes in zooplankton and fish distribution and abundance were observed. This paper discusses the less well known ecosystem component; jellyfish medusae within the Phylum Cnidaria, and their spatial and temporal variation. The long term average was ca. 9×10⁸ kg, with some years showing biomasses in excess of 5×10⁹ kg. The biomasses were low during 1980s, increased during 1990s, and were highest in early 2000s with a subsequent decline. The bulk of the jellyfish were observed in the central parts of the Barents Sea, which is a core area for most 0-group fishes. Jellyfish were associated with haddock in the western area, with haddock and herring in the central and coastal area, and with capelin in the northern area of the Barents Sea. The jellyfish were present in the temperature interval 1°Cjellyfish occurring between 4.0-7.0°C. It seems that the ongoing warming trend may be favourable for Barents Sea jellyfish medusae; however their biomass has showed a recent moderate decline during years with record high temperatures in the Barents Sea. Jellyfish are undoubtedly an important component of the Barents Sea ecosystem, and the data presented here represent the best summary of jellyfish biomass and distribution yet published for the region.

  4. What's in a jellyfish? Proximate and elemental composition and biometric relationships for use in biogeochemical studies

    OpenAIRE

    Lucas, C.H.; Pitt, K. A.; Purcell, J.E.; Lebrato, Mario; R. H. Condon

    2011-01-01

    Many marine organisms have gelatinous bodies, but the trait is most common in the medusae (phylum Cnidaria), ctenophores (phylum Ctenophora), and the pelagic tunicates (phylum Chordata, class Thaliacea). Although there are taxonomic and trophic differences between the thaliaceans and the other two closely related phyla, the collective term "jellyfish" has been used within the framework of this article. Because of the apparent increase in bloom events, jellyfish are receiving greater attention...

  5. Life cycle reversion of Laodicea undulata (Hydrozoa, Leptomedusae) from Japan

    OpenAIRE

    久保田, 信

    2006-01-01

    A mature medusa of Laodicea undulata collected at Okinawa Island, Japan, displayed life cycle reversion, i. e. direct transformation to the polyp stage. The morphology of the reverted polyp is briefly described. This species appears to be the second potentially immortal animal in the Metazoa, after another hydromedusa Turritopsis nutricula, although the present polyp colony, comprising a maximum of 4 zooids despite a wide extension of stolons, degenerated after 5 months without producing a ne...

  6. Seasonality in polyps of a tropical cubozoan: A latina nr mordens.

    Directory of Open Access Journals (Sweden)

    Robert Courtney

    Full Text Available A latina nr mordens have been located in large predictable spawning aggregations near Osprey Reef in the Coral Sea eight to ten days after a full moon; however, polyps have never been located in-situ. The polyp stage contributes to the abundance of medusae through asexual reproduction and metamorphosis, and may influence the periodicity of medusae by metamorphosis of the polyp. To elucidate the relationship between medusae periodicity and polyp ecology, polyps were exposed to thermal and osmotic treatments in order to determine the theoretical environmental limits to their distribution. Maximum fecundity occurred in thermal treatments of 21 to 25ºC and the theoretical minimum thermal requirement for population stability was approximately 17ºC. Polyps were also exposed to five feeding regimes and fecundity was found to be positively correlated with feeding frequency. Thermal and osmotic variations did not induce metamorphosis in this species, however, reduced food did. The implications of asexual reproduction and cues for metamorphosis in relation to population dynamics of this species are discussed.

  7. An endogenous green fluorescent protein-photoprotein pair in Clytia hemisphaerica eggs shows co-targeting to mitochondria and efficient bioluminescence energy transfer.

    Science.gov (United States)

    Fourrage, Cécile; Swann, Karl; Gonzalez Garcia, Jose Raul; Campbell, Anthony K; Houliston, Evelyn

    2014-04-09

    Green fluorescent proteins (GFPs) and calcium-activated photoproteins of the aequorin/clytin family, now widely used as research tools, were originally isolated from the hydrozoan jellyfish Aequora victoria. It is known that bioluminescence resonance energy transfer (BRET) is possible between these proteins to generate flashes of green light, but the native function and significance of this phenomenon is unclear. Using the hydrozoan Clytia hemisphaerica, we characterized differential expression of three clytin and four GFP genes in distinct tissues at larva, medusa and polyp stages, corresponding to the major in vivo sites of bioluminescence (medusa tentacles and eggs) and fluorescence (these sites plus medusa manubrium, gonad and larval ectoderms). Potential physiological functions at these sites include UV protection of stem cells for fluorescence alone, and prey attraction and camouflaging counter-illumination for bioluminescence. Remarkably, the clytin2 and GFP2 proteins, co-expressed in eggs, show particularly efficient BRET and co-localize to mitochondria, owing to parallel acquisition by the two genes of mitochondrial targeting sequences during hydrozoan evolution. Overall, our results indicate that endogenous GFPs and photoproteins can play diverse roles even within one species and provide a striking and novel example of protein coevolution, which could have facilitated efficient or brighter BRET flashes through mitochondrial compartmentalization.

  8. Aurelia aurita-Cnidarian with a prominent medusiod stage.

    Science.gov (United States)

    Matveev, Ivan V; Adonin, Leonid S; Shaposhnikova, Tatiana G; Podgornaya, Olga I

    2012-01-15

    Aurelia aurita has a complex life cycle that consists of several stages including alternating generations of medusa and polyps, huge sexual, and tiny asexual stages. Cnidarian is thought to possess two tissue layers: endoderm (gastroderm) and ectoderm, which are separated by mesoglea in medusa. The determination of the composition of the A. aurita jellyfish mesoglea was performed. New protein "mesoglein" was determined as one of the main components of mesoglea. Mesoglein is synthesized by mesogleal cells (Mc), which are populated A. aurita mesoglea as a high molecular mass precursor. Mc are involved in the formation of noncollagenous "elastic" fibers. Deduced amino acid sequence of mesoglein contains Zona Pellucida (ZP) domain and Delta/Serrate/Lag-2 domain. According to reverse transcription PCR, mesoglein is expressed in the mature medusa exclusively in the Mc. The sperm binding to the ZP is particularly important for successful fertilization. Antibodies against mesoglein stain the plate in the place of contact of germinal epithelium and oocyte. The structure found was named the "contact plate." The contact plate could be the precursor of the ZP. All our data suggest that Mc and, probably, the whole mesoglea originate from the epidermis (ectoderm). Computer search for mesoglein relatives reveals Nematostella and Trichoplax proteins as predicted ORFs, indicating that ZP proteins are quite ancient purchase in the evolution. © 2011 Wiley Periodicals, Inc.

  9. Aurelia labiata jellyfish in Roscoe Bay on the West Coast of Canada: Seasonal changes in adult bell diameter and mingling of juvenile and adult populations

    Science.gov (United States)

    Albert, David J.; Walsh, Michael L.

    2014-01-01

    The bell diameter of adult Aurelia labiata in Roscoe Bay increased from spring (April) to early summer (May/June) and decreased over the rest of the year (2009/2010). The increase in bell diameter in the spring would have been supported by the increase in zooplankton that occurs in the northeast Pacific at this time. Over the summer, bell diameter may have decreased because the food available/medusa would have been decreased by the arrival of a large number of juveniles and may have decreased further over the fall and winter when zooplankton levels are known to be low. Adults and juveniles were intermingled during 2010, 2011, and 2012. Correlations between the number of adults and number of juveniles obtained in individual net lifts across the entire bay and in different parts of the bay were all positive and most were statistically significant. In 2012, salinity in the entire water column of the west side of the bay dropped below 20 ppt in July and most medusae migrated to higher salinity in the east side of the bay, a distance of about 0.5 km. The mingling of adults and juveniles supports other evidence that adult Aurelia sp. medusae do not prey upon juveniles. The ability to withstand months with insufficient food and to inhibit preying on juveniles would contribute greatly to the survival of Aurelia sp. jellyfish.

  10. Towards a phylogenetic classification of Leptothecata (Cnidaria, Hydrozoa).

    Science.gov (United States)

    Maronna, Maximiliano M; Miranda, Thaís P; Peña Cantero, Álvaro L; Barbeitos, Marcos S; Marques, Antonio C

    2016-01-29

    Leptothecata are hydrozoans whose hydranths are covered by perisarc and gonophores and whose medusae bear gonads on their radial canals. They develop complex polypoid colonies and exhibit considerable morphological variation among species with respect to growth, defensive structures and mode of development. For instance, several lineages within this order have lost the medusa stage. Depending on the author, traditional taxonomy in hydrozoans may be either polyp- or medusa-oriented. Therefore, the absence of the latter stage in some lineages may lead to very different classification schemes. Molecular data have proved useful in elucidating this taxonomic challenge. We analyzed a super matrix of new and published rRNA gene sequences (16S, 18S and 28S), employing newly proposed methods to measure branch support and improve phylogenetic signal. Our analysis recovered new clades not recognized by traditional taxonomy and corroborated some recently proposed taxa. We offer a thorough taxonomic revision of the Leptothecata, erecting new orders, suborders, infraorders and families. We also discuss the origination and diversification dynamics of the group from a macroevolutionary perspective.

  11. Pore Water Pumping by Upside-Down Jellyfish

    Science.gov (United States)

    Gaddam, Manikantam; Santhanakrishnan, Arvind

    2016-11-01

    Patchy aggregations of Cassiopea medusae, commonly called upside-down jellyfish, are found in sheltered marine environments with low-speed ambient flows. These medusae exhibit a sessile, non-swimming lifestyle, and are oriented such that their bells are attached to the substrate and oral arms point towards sunlight. Pulsations of their bells are used to generate currents for suspension feeding. Their pulsations have also been proposed to generate forces that can release sediment locked nutrients into the surrounding water. The goal of this study is to examine pore water pumping by Cassiopea individuals in laboratory aquaria, as a model for understanding pore water pumping in unsteady flows. Planar laser-induced fluorescence (PLIF) measurements were conducted to visualize the release of pore water via bell motion, using fluorescent dye introduced underneath the substrate. 2D particle image velocimetry (PIV) measurements were conducted on the same individuals to correlate PLIF-based concentration profiles with the jets generated by pulsing of medusae. The effects of varying bell diameter on pore water release and pumping currents will be discussed.

  12. Time-Dependent Simulation of Free-Electron Laser Amplifiers and Oscillators

    CERN Document Server

    Freund, H

    2005-01-01

    Time-dependent FEL simulations use a variety of techniques. Most simulations use a slowly varying envelope approximation (SVEA). One such technique assumes that the envelope varies only in z combined with a field representation as an ensemble of discrete harmonics, which is equivalent to a time-dependent simulation [1] but is computationally prohibitive. A second technique uses an SVEA in both in z and t [2]. The particles and fields are advanced in z using the same process as in steady-state simulations and then the time derivative describing slippage is applied. This is used in wiggler-averaged codes such as GINGER [3] and GENESIS [4]. We describe the inclusion of this technique in the non-wiggler-averaged code MEDUSA [5], which is applied to amplifiers and oscillators. MEDUSA differs from GINGER and GENESIS also in the way the field is treated. GINGER and GENESIS use a field solver and must explicitly propagate the field outside the wiggler oscillators. This is computationally intensive. MEDUSA uses a Gaus...

  13. How Well Can We Detect Lineage-Specific Diversification-Rate Shifts? A Simulation Study of Sequential AIC Methods.

    Science.gov (United States)

    May, Michael R; Moore, Brian R

    2016-11-01

    Evolutionary biologists have long been fascinated by the extreme differences in species numbers across branches of the Tree of Life. This has motivated the development of statistical methods for detecting shifts in the rate of lineage diversification across the branches of phylogenic trees. One of the most frequently used methods, MEDUSA, explores a set of diversification-rate models, where each model assigns branches of the phylogeny to a set of diversification-rate categories. Each model is first fit to the data, and the Akaike information criterion (AIC) is then used to identify the optimal diversification model. Surprisingly, the statistical behavior of this popular method is uncharacterized, which is a concern in light of: (1) the poor performance of the AIC as a means of choosing among models in other phylogenetic contexts; (2) the ad hoc algorithm used to visit diversification models, and; (3) errors that we reveal in the likelihood function used to fit diversification models to the phylogenetic data. Here, we perform an extensive simulation study demonstrating that MEDUSA (1) has a high false-discovery rate (on average, spurious diversification-rate shifts are identified [Formula: see text] of the time), and (2) provides biased estimates of diversification-rate parameters. Understanding the statistical behavior of MEDUSA is critical both to empirical researchers-in order to clarify whether these methods can make reliable inferences from empirical datasets-and to theoretical biologists-in order to clarify the specific problems that need to be solved in order to develop more reliable approaches for detecting shifts in the rate of lineage diversification. [Akaike information criterion; extinction; lineage-specific diversification rates; phylogenetic model selection; speciation.]. © The Author(s) 2016. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.

  14. Influence of top-down control in the plankton food web on vertical carbon flux: a mesocosm study in the Chesapeake Bay

    Science.gov (United States)

    Stone, J.; Steinberg, D. K.

    2016-02-01

    The effects of predation on carbon export in planktonic food webs are poorly known, but likely play a key role in the biological pump. Gelatinous zooplankton (GZ) dominate the zooplankton community in the Chesapeake Bay during summer months, exerting considerable top-down control on the planktonic food web. The medusa Chrysaora quinquecirrha preys upon the ctenophore Mnemiopsis leidyi, which in turn is a major predator of the omnivorous copepod Acartia tonsa. This trophic cascade is known to significantly affect copepod abundance in Chesapeake Bay, but the resulting changes to particulate organic carbon (POC) flux are unknown. We hypothesized that additions or exclusions of GZ predators would result in changes in both total POC flux and the composition of exported particles (e.g., phytoplankton aggregates, fecal pellets). We conducted mesocosm experiments in the York River tributary of Chesapeake Bay during summer and fall, 2015 to quantify the cascading effects of GZ blooms on POC flux. The mesocosms contained a natural assemblage of phytoplankton and microzooplankton, and A. tonsa copepods, and received one of four treatments of GZ: 1) a control with no GZ added, 2) addition of ctenophores, 3) addition of medusae, and 4) addition of both ctenophores and medusae. POC flux from each mesocosm was measured over multiple 2-day experimental runs and grazing rates of GZ on each other and on copepods were calculated. There were no significant differences in total POC flux between treatments, but the composition of both the final zooplankton assemblage and exported organic matter differed between treatments. As a result of grazing on copepods by ctenophores, treatments which included GZ had lower final copepod abundances and a corresponding decrease in flux of copepod fecal pellets. We discuss how this change in composition of exported material as a result of cascading trophic interactions may affect the efficiency of the biological pump and benthic processes.

  15. Genomic analysis of stress response against arsenic in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Surasri N Sahu

    Full Text Available Arsenic, a known human carcinogen, is widely distributed around the world and found in particularly high concentrations in certain regions including Southwestern US, Eastern Europe, India, China, Taiwan and Mexico. Chronic arsenic poisoning affects millions of people worldwide and is associated with increased risk of many diseases including arthrosclerosis, diabetes and cancer. In this study, we explored genome level global responses to high and low levels of arsenic exposure in Caenorhabditis elegans using Affymetrix expression microarrays. This experimental design allows us to do microarray analysis of dose-response relationships of global gene expression patterns. High dose (0.03% exposure caused stronger global gene expression changes in comparison with low dose (0.003% exposure, suggesting a positive dose-response correlation. Biological processes such as oxidative stress, and iron metabolism, which were previously reported to be involved in arsenic toxicity studies using cultured cells, experimental animals, and humans, were found to be affected in C. elegans. We performed genome-wide gene expression comparisons between our microarray data and publicly available C. elegans microarray datasets of cadmium, and sediment exposure samples of German rivers Rhine and Elbe. Bioinformatics analysis of arsenic-responsive regulatory networks were done using FastMEDUSA program. FastMEDUSA analysis identified cancer-related genes, particularly genes associated with leukemia, such as dnj-11, which encodes a protein orthologous to the mammalian ZRF1/MIDA1/MPP11/DNAJC2 family of ribosome-associated molecular chaperones. We analyzed the protective functions of several of the identified genes using RNAi. Our study indicates that C. elegans could be a substitute model to study the mechanism of metal toxicity using high-throughput expression data and bioinformatics tools such as FastMEDUSA.

  16. Seasonal variation of macromedusae (Cnidaria at North Bay, Florianópolis, southern Brazil

    Directory of Open Access Journals (Sweden)

    Miodeli Nogueira Júnior

    2010-06-01

    Full Text Available Seasonal variation of large medusae abundance and biomass was studied in the North Bay, Santa Catarina, southern Brazil (27°30'S, 48° 32'W, from February to December 2005. Collecting was conducted seasonally with the help of fishing bottom trawl in 30-minute sections (12 in summer, 18 in each of the remaining seasons in six stations, totaling 66 samples. Eight species were found: the hydrozoans Aequorea sp., Olindias sambaquiensis Müller, 1861, and Rhacostoma atlantica L. Agassiz, 1850; the cubozoans Chiropsalmus quadrumanus (Müller, 1859 and Tamoya haplonema Müller, 1859, and the scyphozoans Aurelia sp., Chrysaora lactea Eschscholtz, 1829 and Lychnorhiza lucerna Haeckel, 1880. Capture rates were low, up to 38 indiv. ha-1, and only ~47% of the samples were positive for jellyfish, comprising 206 individuals. Medusae abundance and species richness clearly changed from one season to another, but did not vary between the sites. Higher species richness (7 out of 8 and greater abundances were recorded during the fall (~60% and 72% of all medusae individuals and biomass respectively. Specific frequency of capture varied from 1.5 to 29% and C. lactea was the only species found in more than 25% of the samples. The three most common species dominated in different periods of the year: C. lactea during fall (78% of individuals and 60% of biomass, R. atlantica during winter (90% of individuals and 17% of biomass, and O. sambaquiensis in spring (78% of individuals and 40% of biomass. Only two individuals were caught during summer, one C. lactea and one R. atlantica. The results offer a general picture of the distribution of the macromedusae in the North Bay, but a continuous monitoring is desirable for a more detailed knowledge on the jellyfish dynamics in the Brazilian coastal waters.

  17. Feeding behaviour of the hydromedusa Aequorea vitrina

    Directory of Open Access Journals (Sweden)

    Hans Ulrik RiisgÅrd

    2007-06-01

    Full Text Available The prey-capture mechanism of the hydromedusa Aequorea vitrina was studied by means of laboratory video-microscope observations. In stagnant water A. vitrina remains stationary with its very long (about 4x bell diameter marginal tentacles motionless hanging down in the water, ready for ambush capture of prey organisms that collide with the tentacles. A. vitrina was found to be efficient at capturing brine shrimps (Artemia salina, less efficient at capturing rotifers (Brachionus plicatilis, and very inefficient at capturing copepods (Acartia tonsa. The initial hauling up of an extended marginal tentacle with an adhering prey is fast (>10 mm s-1. Both the bell margin and the mouth move towards each other so that the captured prey can be transferred from the tentacle to the elongated mouth-lips to be further transported into the mouth and stomach. It takes about 20 s from when an Artemia prey organism encounters a tentacle until it is transferred to the mouth-lips. The subsequent digestion in the stomach takes about 30 min. When A. vitrina encounters a jellyfish-prey (a small medusa of Aurelia aurita, it starts to swim in order to adhere the relatively big prey to its mouth-lips. Then A. vitrina opens its mouth wide to swallow the captured medusa, a process which takes about 15 to 20 min. The subsequent digestion takes 2 to 3 h. Field observations of undisturbed A. vitrina made by snorkelling in the Limfjord (Denmark revealed that the feeding behaviour was similar to that observed in the laboratory in stagnant water. It is concluded that A. vitrina is an ambush-predator, and not a cruising-predatory medusa as previously suggested.

  18. Insight into the molecular and functional diversity of cnidarian neuropeptides.

    Science.gov (United States)

    Takahashi, Toshio; Takeda, Noriyo

    2015-01-23

    Cnidarians are the most primitive animals to possess a nervous system. This phylum is composed of the classes Scyphozoa (jellyfish), Cubozoa (box jellyfish), and Hydrozoa (e.g., Hydra, Hydractinia), which make up the subphylum Medusozoa, as well as the class Anthozoa (sea anemones and corals). Neuropeptides have an early evolutionary origin and are already abundant in cnidarians. For example, from the cnidarian Hydra, a key model system for studying the peptides involved in developmental and physiological processes, we identified a wide variety of novel neuropeptides from Hydra magnipapillata (the Hydra Peptide Project). Most of these peptides act directly on muscle cells and induce contraction and relaxation. Some peptides are involved in cell differentiation and morphogenesis. In this review, we describe FMRFamide-like peptides (FLPs), GLWamide-family peptides, and the neuropeptide Hym-355; FPQSFLPRGamide. Several hundred FLPs have been isolated from invertebrate animals such as cnidarians. GLWamide-family peptides function as signaling molecules in muscle contraction, metamorphosis, and settlement in cnidarians. Hym-355; FPQSFLPRGamide enhances neuronal differentiation in Hydra. Recently, GLWamide-family peptides and Hym-355; FPQSFLPRGamide were shown to trigger oocyte maturation and subsequent spawning in the hydrozoan jellyfish Cytaeis uchidae. These findings suggest the importance of these neuropeptides in both developmental and physiological processes.

  19. What's on the mind of a jellyfish? A review of behavioural observations on Aurelia sp. jellyfish.

    Science.gov (United States)

    Albert, David J

    2011-01-01

    Aurelia sp. (scyphozoa; Moon Jellies) are one of the most common and widely distributed species of jellyfish. Their behaviours include swimming up in response to somatosensory stimulation, swimming down in response to low salinity, diving in response to turbulence, avoiding rock walls, forming aggregations, and horizontal directional swimming. These are not simple reflexes. They are species typical behaviours involving sequences of movements that are adjusted in response to the requirements of the situation and that require sensory feedback during their execution. They require the existence of specialized sensory receptors. The central nervous system of Aurelia sp. coordinates motor responses with sensory feedback, maintains a response long after the eliciting stimulus has disappeared, changes behaviour in response to sensory input from specialized receptors or from patterns of sensory input, organizes somatosensory input in a way that allows stimulus input from many parts of the body to elicit a similar response, and coordinates responding when stimuli are tending to elicit more than one response. While entirely different from that of most animals, the nervous system of Aurelia sp. includes a brain that creates numerous adaptive behaviours that are critical to the survival of these phylogenetically ancient species. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. Mesogleal cells of the jellyfish Aurelia aurita are involved in the formation of mesogleal fibres.

    Science.gov (United States)

    Shaposhnikova, Tatiana; Matveev, Ivan; Napara, Tatiana; Podgornaya, Olga

    2005-11-01

    The extracellular matrix of the jellyfish Aurelia aurita (Scyphozoa, Cnidaria), known as the mesoglea, is populated by numerous mesogleal cells (Mc). We determined the pattern of the Mc and the mesoglea, raised polyclonal antibodies (RA47) against the major mesogleal protein pA47 (47 kDa) and checked their specificity. In the mesoglea, RA47 stains pA47 itself. In immunoblots of Mc, RA47 stains bands of 120 kDa and 80 kDa; weaker staining is observed at pA47. The same staining pattern is seen on blots of jellyfish epidermal cells and of whole Hydra (Hydrozoa) or isolated mesoglea of Hydra. Our data indicate that pA47 is synthesized by Mc and epidermal cells as high molecular precursors. Using immunostaining techniques, we showed Mc to be involved in the formation of mesogleal non-collagenous (called "elastic" in classic morphological studies) fibres. The biochemical and morphological data suggest that Mc originate from the epidermis.

  1. Sea Water Acidification Affects Osmotic Swelling, Regulatory Volume Decrease and Discharge in Nematocytes of the Jellyfish Pelagia noctiluca

    Directory of Open Access Journals (Sweden)

    Rossana Morabito

    2013-12-01

    Full Text Available Background: Increased acidification/PCO2 of sea water is a threat to the environment and affects the homeostasis of marine animals. In this study, the effect of sea water pH changes on the osmotic phase (OP, regulatory volume decrease (RVD and discharge of the jellyfish Pelagia noctiluca (Cnidaria, Scyphozoa nematocytes, collected from the Strait of Messina (Italy, was assessed. Methods: Isolated nematocytes, suspended in artificial sea water (ASW with pH 7.65, 6.5 and 4.5, were exposed to hyposmotic ASW of the same pH values and their osmotic response and RVD measured optically in a special flow through chamber. Nematocyte discharge was analyzed in situ in ASW at all three pH values. Results: At normal pH (7.65, nematocytes subjected to hyposmotic shock first expanded osmotically and then regulated their cell volume within 15 min. Exposure to hyposmotic ASW pH 6.5 and 4.5 compromised the OP and reduced or totally abrogated the ensuing RVD, respectively. Acidic pH also significantly reduced the nematocyte discharge response. Conclusion: Data indicate that the homeostasis and function of Cnidarians may be altered by environmental changes such as sea water acidification, thereby validating their use as novel bioindicators for the quality of the marine environment.

  2. Interactions of cnidarian toxins with the immune system.

    Science.gov (United States)

    Suput, Dusan

    2011-10-01

    Cnidarians comprise four classes of toxic marine animals: Anthozoa, Cubozoa, Scyphozoa and Hydrozoa. They are the largest and probably the oldest phylum of toxic marine animals. Any contact with a cnidarian, especially the box jellyfish (Chironex fleckeri), can be fatal, but most cnidarians do not possess sufficiently strong venomous apparatus to penetrate the human skin, whereas others rarely come into contact with human beings. Only a small, almost negligible percentage of the vast wealth of cnidarian toxins has been studied in detail. Many polypeptide cnidarian toxins are immunogenic, and cross-reactivity between several jellyfish venoms has been reported. Cnidarians also possess components of innate immunity, and some of those components have been preserved in evolution. On the other hand, cnidarian toxins have already been used for the design of immunotoxins to treat cancer, whereas other cnidarian toxins can modulate the immune system in mammals, including man. This review will focus on a short overview of cnidarian toxins, on the innate immunity of cnidarians, and on the mode of action of cnidarian toxins which can modulate the immune system in mammals. Emphasis is palced on those toxins which block voltage activated potassium channels in the cells of the immune system.

  3. Scyphomedusae of the Mediterranean: state of the art and future perspectives.

    Science.gov (United States)

    D'Ambra, Isabella; Malej, Alenka

    2015-01-01

    Scyphomedusae (Phylum Cnidaria, Class Scyphozoa) are perceived as a nuisance due to their sudden outbreaks that negatively affect human activities (particularly tourism and fisheries) mainly because of their stings. A brief review of the history of scyphozoan blooms in the Mediterranean and updated information available after 2010 point to an increase in scyphozoan outbreaks. Whilst the negative effects on public health, aquaculture, coastal industrial activities and fisheries operations are undeniable, the effects on the ecosystem are not well defined. We focus on the trophic interactions between scyphomedusae and fish, highlighting that the negative effects of scyphomedusae on fish stocks exerted through direct predation on early life stages of fish and competition for plankton are at present speculative. In favor of a positive effect of scyphomedusae on fish populations, the reports of predation upon scyphozoans are increasing, which suggests that predators may benefit from the availability of scyphozoans by shifting their diet toward jelly prey. Additionally, scyphomedusae may provide nursery habitats to early life stages of ecologically and economically important forage fishes and other organisms which shelter underneath their bells. Together with these ecosystem services, compounds extracted from scyphozoan tissues and venoms are having a variety of biomedical applications and are likely to contribute to treat a growing number of diseases, including cancer. Our analysis highlights that a re-evaluation of the balance between "positive" and "negative" effects of scyphomedusae on the ecosystem and human activities is needed and provides indications on potential directions for future studies.

  4. [Problems caused by poisonous tropical marine animals].

    Science.gov (United States)

    Lääveri, Tinja; Räisänen-Sokolowski, Anne; Jama, Timo

    2014-01-01

    A Finnish physician encounters problems caused by tropical marine animals either during her/his own travelling or while treating travelers who have returned home. Certain species of medusae and cone shells as well as the stings by some fish species are life-threateningly poisonous. A person stung or bitten by any of the most dangerous species must immediately be admitted to the hospital. Foreign material remaining in tissues after stings by echinoderms and spiky fish may cause problems months after the actual injury. The injuries become easily infected, and antimicrobial drug therapy must thus cover gram-negative rod-shaped bacteria as well.

  5. Properties of the Medussae Fossae Formation and its relation to the volcanic history of Mars

    Science.gov (United States)

    Ivanov, Anton B.; Cantini, Federico

    2016-10-01

    Medussae Fossae (MFF) is a well known formation, stretching west of Tharsis volanoes. It is characterized as a relatively young Amazonian units (Amm, Amu), due to widespread signs of erosion. Earth based imaging radar observations at 3.5 cm [1] and 12 cm [2] have discovered a dark radar feature (Stealth), which roughly correlates with the MFF outline.Recent investigations [3], suggested that the unit emplacement is in fact during Hesperian period, but it is composed of material that can be easily eroded. It is not clear when the erosion happened and if it is a continuing process. Hypotheses on MFF formation range from volcanic material emplacement (ash flow tuffs or pyroclastic materials) to an ice-rich dusty mantle, deposited during high obliquity.In this work, we will present the latest observations of the East Medussae Fossae formation by the long wavelength MARSIS radar, continuing the work reported in [4], as well as complementing data surveyed by SHARAD data in [5]. The MARSIS radar has detected strong subsurface interfaces in the areas of Gordi and Eumenides Dorsae at depths up to 1.5km. We will present our analysis of the data, inferring the dielectric properties of the material to constrain properties of the material constituting the Medusae Fossae formation. We will also demonstrate an efficient user interface to work with MARSIS data inside a Geographical Information System (GIS).The research leading to these results has received funding from the European Unions Seventh Framework Programme (FP7/2007-2013) under iMars grant agreement 607379.[1] D. Muhleman, et al., "Radar images of mars," Science, vol. 253, no. 5027, 1991.[2] J. K. Harmon, et al., "Arecibo radar imagery of Mars: The major volcanic provinces," Icarus, vol. 220, aug 2012.[3] L. Kerber, et al., "The dispersal of pyroclasts from Apollinaris Patera, Mars: Implications for the origin of the Medusae Fossae Formation," Icarus, vol. 216, nov 2011.[4] T. R. Watters, et al., "Radar Sounding of the

  6. Midwater Bioluminescence Assessment in the West Alboran Gyre (Mediterranean Sea)

    Science.gov (United States)

    1991-09-01

    Mediterranean (see Mills and Goy, m 1988, for review), moving up into the upper 100 m during the night. Our night dive observations tented to support that...413 484.7 91.4I 57)491 Nepheloctena white- tent -ade 2939-CGS Creno 511 491.2 86.3 P42)491 Ocyropsis macalata BWI-4 Creno 356 492.2 86.3 F39)491...umbrellar margin. Solmissus (the single most abundant medusa) is also transparent and brightly luminescent from the lateral umbrellar margin,the velum

  7. Increasing marketability and profitability of product line thru PATRAN and NASTRAN

    Science.gov (United States)

    Hyatt, Art

    1989-01-01

    Starting with the design objective the operational cycle life of the Swaging Tool was increased. To accomplish this increase in cycle life without increasing the size or weight of the tool would be engineering achievement. However, not only was the operational cycle life increased between 2 to 10 times but simultaneously the size and weight of the Swage Tool was decreased by about 50 percent. This accomplishment now becomes an outstanding engineering achievement. This achievement was only possible because of the computerized Patran, Nastran and Medusa programs.

  8. Measurements of prompt radiation induced conductivity in Teflon (PTFE).

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, E. Frederick; Zarick, Thomas Andrew; Sheridan, Timothy J.; Preston, E. [ITT Exelis Mission Systems, Colorado Springs, CO

    2013-05-01

    We performed measurements of the prompt radiation induced conductivity (RIC) in thin samples of Teflon (PTFE) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil (76.2 microns) samples were irradiated with a 0.5 %CE%BCs pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E11 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Details of the experimental apparatus and analysis are reported in this report on prompt RIC in Teflon.

  9. Measurements of prompt radiation induced conductivity of Kapton.

    Energy Technology Data Exchange (ETDEWEB)

    Preston, Eric F. (ITT Corporation, Colorado Springs, CO); Zarick, Thomas Andrew; Sheridan, Timothy J.; Hartman, E. Frederick; Stringer, Thomas Arthur (ITT Corporation, Colorado Springs, CO)

    2010-10-01

    We performed measurements of the prompt radiation induced conductivity in thin samples of Kapton (polyimide) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil samples were irradiated with a 0.5 {mu}s pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E10 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Analysis rendered prompt conductivity coefficients between 6E-17 and 2E-16 mhos/m per rad/s, depending on the dose rate and the pulse width.

  10. Variaciones morfológicas en Blackfordia virginica (Hydroidomedusae: Blackfordiidae) en lagunas costeras de Chiapas, México

    OpenAIRE

    Carlos Álvarez Silva; Samuel Gómez Aguirre; Ma. Guadalupe Miranda Arce

    2003-01-01

    Blackfordia virginica es una hidromedusa importante en el zooplancton de lagunas costeras de México. Con el objeto de contribuir a su estudio se analizaron las variaciones morfológicas de esta especie en el sistema de lagunas costeras de Chiapas, México. Se estudiaron 503 ejemplares, sus tallas variaron de 6.1 a 9.9 mm de diámetro umbrelar; el número de tentáculos marginales varió de 86 a 125. Se reconocieron los sexos, 67.7% hembras y 30.2% machos. Solamente 31 medusas (26 hembras y cinco ma...

  11. Diagrama de estabilidad termodinámico del sistema de flotación cobre/agua/amilxantato

    OpenAIRE

    Beatriz Ramírez-Serrano; Alexis Otero-Calvis; Alfredo Coello-Velazquez

    2015-01-01

    El propósito del trabajo fue obtener el diagrama de estabilidad termodinámico que caracteriza al sistema de flotación cobre/agua/amilxantato, como parte del fundamento teórico necesario para el análisis del proceso de flotación de iones cobre con el reactivo colector de flotación amilxantato de potasio. A partir del sistema de reacciones químicas fundamentales y con ayuda del sofware Medusa se obtuvo el diagrama Eh-pH en el cual se definen las zonas de estabilidad de las diferentes especies q...

  12. MITIGATE - Deliverable D2.2 - Evidence-driven maritime supply chain risk assessment approach

    OpenAIRE

    Polemi, Nineta; Papastergiou, Spyridon; Karantzias, Athanassios; Georgiakodis, Fotios; Patsakis, Constantinos; Ntrigkogias, Christos; Schauer, Stefan; Latzenhofer, Martin; König, Sandra; Göllner, Johannes; Buhl, Reiner; FIEDLER, Ralf; Bosse, Claudia; Mouratidis, Haris; Pavlidis, Michalis

    2016-01-01

    Deliverable 2.2 reports the outcomes of tasks T2.3 “Specifications of Mathematical Instruments, Risk and Assurance Models” and T2.4 “Evidence-Driven Maritime Supply Chain Risk Assessment (g-MSRA) Specifications” of work package WP2. The document identifies three methodologies and frameworks; viz. Secure Tropos, AECID and MEDUSA, that are deemed relevant to the project and provided input in the formulation of the MITIGATE methodology or can be exploited in the implementation phase of the MITIG...

  13. Sexing or Specularizing the Doppelgänger: A Recourse to Poe's ‘Ligeia'

    DEFF Research Database (Denmark)

    Sencindiver, Susan Yi

    2010-01-01

    The fictional doppelgänger resists narrow categorization and definition, yet exhibits a peculiar feature: it is claimed to be the exclusive property of the male gender. As a sole male phenomenon, the doppelgänger would seem to fortify the essentialist scheme of a gendered identity. However, as th...... integral to the formation of subjectivity. To substantiate this framework, Edgar Allan Poe's "Ligeia" will be read as a paradigmatic example, in which its title character emerges as a terrifying Medusa-like doppelgänger....

  14. Perseus as Alter Ego of Ferdinand I

    OpenAIRE

    Bažant, J. (Jan)

    2016-01-01

    The paper analyses three relief sculptures that decorate spandrels of the northern façade of the Prague Belvedere, which was built by Ferdinand I in 1538–c.1550. Their uniqueness consists in that it is the first series inspired by the myth of Perseus in Renaissance architectural sculpture. We find here, from left to right: Perseus freeing Andromeda, Perseus turning Atlas into the rock by showing him the head of Medusa, and Pegasus creating a source of poetical inspiration. At the right follow...

  15. A espécie exótica Blackfordia virginica no estuário do Mira:

    OpenAIRE

    Marques, Filipa da Costa, 1989-

    2013-01-01

    Tese de mestrado. Biologia (Ecologia Marinha). Universidade de Lisboa, Faculdade de Ciências, 2013 Blackfordia virginica é um cnidário nativo do sudeste da Europa ou da costa atlântica da América do Norte, introduzido em diversos sistemas estuarinos em todo o mundo, tendo sido registada pela primeira vez no estuário do rio Mira em 1984. O presente estudo teve como principais objectivos (i) determinar a variação espacial e temporal da abundância e estrutura dimensional da medusa de B. virgi...

  16. El mito de Perseo en los mosaicos hispanorromanos : particularidades hispanas

    Directory of Open Access Journals (Sweden)

    Guadalupe López Monteagudo

    1998-01-01

    Full Text Available Análisis iconográfico de las distintas fases del mito de Perseo en ios mosaicos romanos, siguiendo las fuentes literarias - Dánae recibiendo la lluvia de oro, llegada de Dánae con el niño Perseo a las costas de Seripfios, Perseo dando muerte a la medusa volviendo la cabeza al escudo de Atfienea, llegada del tiéroe volando ai lugar donde se fiallaba expuesta Andrómeda, Perseo vencedor de la medusa y del kethos, Perseo contemplando a Andrómeda encadenada a la roca, el gorgoneion en el centro de un escudo de triángulos curvilíneos o de escamas en alusión a la égida o ai escudo de Atlienea - y las creaciones artísticas típicamente romanas - Perseo liberando a Andrómeda y Perseo y Andrómeda contemplando la cabeza de la medusa en el agua - con especial atención al tratamiento iconográfico y alegórico de los ejemplares hispanos.Iconograpfíical analysis of the Perseus' mytfi related on the román mosaics, througfi the literary sources - Danae and the goiden rain, Danae and Perseus arriving at Seriphos' coast, Perseus cutting de Medusa's head and turning back his head toward Athenea's shield, Perseus' arrival fiying on the site where Andrómeda is exposed against the rock, the hero hoiding the gorgoneion in the raised hand over kethos, the mude contemplation of the giri's beauty, Gorgon's head at centre of shield of lozenges or imbhcation pattern - and the original figured representations created by román art - Perseus helps Andrómeda step down from the cliff where she was chained and the two lovers seatted on a rock with the gorgoneion held overhead to reflect in the water - with a special emphasis in the iconographical variations and symbolic significance of the spanish patterns.

  17. [Conversations with the Sphinx. Images of Greek myth in Freud's collection].

    Science.gov (United States)

    Burke, Janine

    2006-01-01

    In Freud's art collection, the myth of Oedipus, a central tenet of psychoanalysis, is represented by several Greek statues and vases, as well as a reproduction of Ingres' painting. Originally a protective male Egyptian deity, in Greek myth, the Sphinx was female and associated with death. In addition, Freud had sculptures of Medusa the Gorgon, a terrifying winged female, and of provocative Baubo, both also figuring in his writings. By describing these works of art and some of their mythological ramifications, the author suggests that they represented aspects of feminity not really covered by Freud's theories.

  18. National Oceanographic Fleet Operating Schedules for 1983.

    Science.gov (United States)

    1983-01-01

    COLWELL ... NSF PEP: 27APR 83MIAMI, FL STUDIES OF MARINE BACTERIA PUERTOARR: 10 MAY l3 MIAMI, FL TRENCH. PUERTO RICO PORT CALL 13 AREA INDEX: NA9... MANZANILLO , MX AREA INDEX: NP9 NP13 OCEANOGRAPHIC RESEARCH FOXREA SCRIPPS DIP: Q FEB 8l3 MANZANILLO NX PASCUA LEG 2. SEABEAM TO DEINE S ARR: FEB EASTER...of Puerto Rico CRAWFORD 125 Caribbean Sea M.L. Hernandez- Dept. of Marine Sciences MEDUSA 56 Avi Mayaguez, Puerto Rico 00708 (809)832-4040, Ext. 3439

  19. Box jellyfish use terrestrial visual cues for navigation

    DEFF Research Database (Denmark)

    Garm, Anders; Oskarsson, Magnus; Nilsson, Dan-Eric

    2011-01-01

    Box jellyfish have an impressive set of 24 eyes of four different types, including eyes structurally similar to those of vertebrates and cephalopods [1, 2]. However, the known visual responses are restricted to simple phototaxis, shadow responses, and object avoidance responses [3-8], and it has...... been a puzzle why they need such a complex set of eyes. Here we report that medusae of the box jellyfish Tripedalia cystophora are capable of visually guided navigation in mangrove swamps using terrestrial structures seen through the water surface. They detect the mangrove canopy by an eye type...

  20. Swim pacemakers in box jellyfish are modulated by the visual input

    DEFF Research Database (Denmark)

    Garm, Anders Lydik; Bielecki, Jan

    2008-01-01

    A major part of the cubozoan central nervous system is situated in the eye-bearing rhopalia. One of the neuronal output channels from the rhopalia carries a swim pacemaker signal, which has a one-to-one relation with the swim contractions of the bell shaped body. Given the advanced visual system ...... become more homogeneously distributed. A rise in intensity, on the other hand, produces a steep decline in the frequency and makes the ISIs highly variable. These electrophysiological data are correlated with behavioral observations from the natural habitat of the medusae....

  1. Conservation state of populations of rare plant species in highly transformed meadow steppes of Southern Opillya

    Directory of Open Access Journals (Sweden)

    I. I. Dmytrash-Vatseba

    2016-09-01

    Full Text Available Degradation of natural habitats causes rapid extinction of rare plant populations. The diversity of rare plant species in the meadow steppes of Southern Opillya (Western Ukraine depends strongly on patch area, pasture digression of vegetation and a variety of eco-coenotical conditions. The main threats for the rare components of the meadow steppe flora are reduction of habitat and overgrazing. Spatial connections between sites are unable to support a constant rare plant population. The analysis of the composition of rare plant meadow-steppe species indicated that habitats with similar rare species composition usually have similar parameters of area, stages of pasture digression and eco-coenotical conditions. Spatial connectivity of patches does not ensure species similarity of rare components of the flora. Rare plant species were grouped according to their preferences for habitat , area and condition. In small patches subject to any stage of pasture digression grow populations of Adonis vernalis L., Pulsatilla patens (L. Mill., P. grandis Wender., Stipa capillata L., S. рennata L., Chamaecytisus blockianus (Pawł. Klásková etc. On the contrary, populations of other species (Carlina onopordifolia Besser. ex Szafer., Kuecz. et Pawł., Adenophora liliifolia (L. Ledeb. ex A. DC., Crambe tataria Sebeók, Euphorbia volhynica Besser ex Racib., Stipa tirsa Stev. etc. prefer large habitats, not changed by pasture digression. Prevention of reduction of rare species diversity requires preservation (also extension of patch area and regulation of grazing intensity.

  2. Postembryonic development of the parasitic amphipod Hyperia galba

    Science.gov (United States)

    Dittrich, Birgit

    1987-06-01

    Hyperia galba Montagu is associated with gelatinous zooplankton as are many species of the Hyperiidea. The hosts preferred in the European seas are the large scyphomedusae Aurelia aurita, Chrysaora hysoscella, Rhizostoma pulmo, Cyanea capillata and Cyanea lamarckii, which harbour the first developmental stages. The anamorphic development produces young that are incapable of swimming at the time of hatching. They are characterized by an embryonic abdomen without extremities and external segmentation; the eyes are not completely developed and the mouth is primitive lacking bristles, molar and incisor. The postembryonic development, described in detail, is subdivided into two phases: the pantochelis phase and the protopleon phase; the former comprises only one stage; the latter can be subdivided into four stages. In the course of postnatal development the larval organs are reduced and characters typical of the adult are gradually differentiated. H. galba plays an important role as obligatory endoparasite of scyphomedusae at least during the first stages of development; without a host this amphipod cannot survive, neither benthically nor in the plankton. The transition from life in the female's marsupium to endoparasitism in the jellyfish generally occurs during stage of the postembryonic development which is the first stage of the protopleon phase. The specific adaptations of its reproductive biology to a parasitic mode of life such as moult inhibition under starvation, development of larval organs and the behavioural patterns of the females as well as the young are described. Further, the influence of external factors such as temperature and food supply on the course of development is examined.

  3. Steppe-Like Grass Land Vegetation in the Hills around the Lakes of Vegoritida and Petron, North-Central Greece

    Directory of Open Access Journals (Sweden)

    Pirini Chrisoula B.

    2014-06-01

    Full Text Available V članku opisujemo floristično sestavo in sinekologijo stepi podobnih suhih travišč, ki se pojavljajo v Natura 2000 območju v severni centralni Grčiji okoli dveh kraških jezer Vegoritida in Petron. Vzorčili smo 245 vegetacijskih popisov in jih analizirali s klastrsko in ordinacijsko analizo. Rastišče smo interpretirali s pasivnimi pojasnjevalnimi spremenljivkami, kamor smo vključili okoljske spremenljivke in indikatorske vrednosti. Na raziskovanem območju smo ločili štiri rastlinske združbe: Artemisia campestris-Dasypyrum villosum, Chrysopogon gryllus-Bothriochloa ischaemum, Satureja montana-Artemisia alba in Stipa capillata-Koeleria macrantha. Vse združbe smo uvrstili v razred Festuco-Brometea in red Astragalo-Potentilletalia. Lastnosti tal (reakcija tal in mezo klimatski dejavniki (spreminjanje temperature vzdolž topografskih gradientov so glavni dejavniki, ki vplivajo na floristične razlike med štirimi rastlinskimi združbami.

  4. Studying large jellyfish swimming hydrodynamics using a biomimetic robot named Cyro 2

    Science.gov (United States)

    Stewart, Colin; Krummel, Gregory; Villanueva, Alex; Marut, Kenneth; Priya, Shashank

    2015-11-01

    Some species of jellyfish can grow to great sizes, such as the lion's mane jellyfish (Cyanea capillata), which can span 2 m in diameter with tentacles 30 m long, roughly the same length as a blue whale. This is an impressive feat for an animal that begins its mobile life three orders of magnitude smaller. Such growth can require a large energy budget, suggesting that Cyanea may be a uniquely efficient swimmer, successful predator, or both. Either accolade would stem from a high level of hydrodynamic mastery as oblate jellyfish like Cyanea rely on the flow currents generated by bell pulsation for both propulsive thrust and prey encounter. However, further investigation has been hindered by the lack of reported quantitative flow measurements, perhaps due to the logistic challenges inherent to studying large specimen in vivo. Here, we used a 50 cm diameter biomimetic Cyanea robot named Cyro 2 as a proxy to study the hydrodynamics of large jellyfish. The effect of different trailing structure morphologies (e.g. oral arms and tentacles), swimming gaits, and kinematics on flow patterns were measured using PIV. Baseline swimming performance using biomimetic settings (but no trailing structures) was characterized by a cycle average velocity of 6.58 cm s-1, thrust of 1.9 N, and power input of 5.7 W, yielding a vehicle efficiency of 2.2% and a cost of transport of 15.4 J kg-1 m-1.

  5. Detection of microvasculature alterations by synchrotron radiation in murine with delayed jellyfish envenomation syndrome.

    Science.gov (United States)

    Wang, Beilei; Zhang, Bo; Huo, Hua; Wang, Tao; Wang, Qianqian; Wu, Yuanlin; Xiao, Liang; Ren, Yuqi; Zhang, Liming

    2014-04-01

    Using the tentacle extract (TE) from the jellyfish Cyanea capillata, we have previously established a delayed jellyfish envenomation syndrome (DJES) model, which is meaningful for clinical interventions against jellyfish stings. However, the mechanism of DJES still remains unclear. Thus, this study aimed to explore its potential mechanism by detecting TE-induced microvasculature alterations in vivo and ex vivo. Using a third-generation synchrotron radiation facility, we, for the first time, directly observed the blood vessel alterations induced by jellyfish venom in vivo and ex vivo. Firstly, microvasculature imaging of whole-body mouse in vivo indicated that the small blood vessel branches in the liver and kidney in the TE-treated group, seemed much thinner than those in the control group. Secondly, 3D imaging of kidney ex vivo showed that the kidneys in the TE-treated group had incomplete vascular trees where distal vessel branches were partly missing and disorderly disturbed. Finally, histopathological analysis found that obvious morphological changes, especially hemorrhagic effects, were also present in the TE-treated kidney. Thus, TE-induced microvasculature changes might be one of the important mechanisms of multiple organ dysfunctions in DJES. In addition, the methods we employed here will probably facilitate further studies on developing effective intervention strategies against DJES.

  6. Green Fluorescence of Cytaeis Hydroids Living in Association with Nassarius Gastropods in the Red Sea

    KAUST Repository

    Prudkovsky, Andrey A.

    2016-02-03

    Green Fluorescent Proteins (GFPs) have been reported from a wide diversity of medusae, but only a few observations of green fluorescence have been reported for hydroid colonies. In this study, we report on fluorescence displayed by hydroid polyps of the genus Cytaeis Eschscholtz, 1829 (Hydrozoa: Anthoathecata: Filifera) found at night time in the southern Red Sea (Saudi Arabia) living on shells of the gastropod Nassarius margaritifer (Dunker, 1847) (Neogastropoda: Buccinoidea: Nassariidae). We examined the fluorescence of these polyps and compare with previously reported data. Intensive green fluorescence with a spectral peak at 518 nm was detected in the hypostome of the Cytaeis polyps, unlike in previous reports that reported fluorescence either in the basal parts of polyps or in other locations on hydroid colonies. These results suggest that fluorescence may be widespread not only in medusae, but also in polyps, and also suggests that the patterns of fluorescence localization can vary in closely related species. The fluorescence of polyps may be potentially useful for field identification of cryptic species and study of geographical distributions of such hydroids and their hosts.

  7. Diversity dynamics in Nymphalidae butterflies: effect of phylogenetic uncertainty on diversification rate shift estimates.

    Science.gov (United States)

    Peña, Carlos; Espeland, Marianne

    2015-01-01

    The species rich butterfly family Nymphalidae has been used to study evolutionary interactions between plants and insects. Theories of insect-hostplant dynamics predict accelerated diversification due to key innovations. In evolutionary biology, analysis of maximum credibility trees in the software MEDUSA (modelling evolutionary diversity using stepwise AIC) is a popular method for estimation of shifts in diversification rates. We investigated whether phylogenetic uncertainty can produce different results by extending the method across a random sample of trees from the posterior distribution of a Bayesian run. Using the MultiMEDUSA approach, we found that phylogenetic uncertainty greatly affects diversification rate estimates. Different trees produced diversification rates ranging from high values to almost zero for the same clade, and both significant rate increase and decrease in some clades. Only four out of 18 significant shifts found on the maximum clade credibility tree were consistent across most of the sampled trees. Among these, we found accelerated diversification for Ithomiini butterflies. We used the binary speciation and extinction model (BiSSE) and found that a hostplant shift to Solanaceae is correlated with increased net diversification rates in Ithomiini, congruent with the diffuse cospeciation hypothesis. Our results show that taking phylogenetic uncertainty into account when estimating net diversification rate shifts is of great importance, as very different results can be obtained when using the maximum clade credibility tree and other trees from the posterior distribution.

  8. Ecological aspects and potential impacts of the non-native hydromedusa Blackfordia virginica in a temperate estuary

    Science.gov (United States)

    Marques, Filipa; Angélico, Maria Manuel; Costa, José Lino; Teodósio, Maria Alexandra; Presado, Patrícia; Fernandes, António; Chainho, Paula; Domingos, Isabel

    2017-10-01

    The hydrozoan Blackfordia virginica has been reported over a wide geographical area, although it is mainly restricted to scattered records within estuarine areas of temperate and tropical regions. The aim of this study was to understand the spatial and temporal variability of an established population of this non-indigenous species on a temperate estuarine ecosystem, and its impacts over the plankton community. Sampling was conducted from 2011 to 2013 in the Mira estuary (Portugal) and higher densities were observed during the summer of 2013, with a maximum of 1689.3 medusae.m-3. Spatially, higher abundances of medusae were associated with sites of higher abundance of oyster shells and higher percentage of hard substrate in the river bed. Smaller jellyfish were sampled in the vicinity of these hard substrate locations, suggesting these might be habitats for polyp fixation. A higher potential predation impact on the copepod population along the estuary was estimated for the summer of 2013, with a median half life of 6.1 days.

  9. Environmental factors influencing the spatio-temporal distribution of Carybdea marsupialis (Lineo, 1978, Cubozoa) in South-Western Mediterranean coasts.

    Science.gov (United States)

    Canepa, Antonio; Fuentes, Verónica; Bosch-Belmar, Mar; Acevedo, Melissa; Toledo-Guedes, Kilian; Ortiz, Antonio; Durá, Elia; Bordehore, César; Gili, Josep-Maria

    2017-01-01

    Jellyfish blooms cause important ecological and socio-economic problems. Among jellyfish, cubozoans are infamous for their painful, sometimes deadly, stings and are a major public concern in tropical to subtropical areas; however, there is little information about the possible causes of their outbreaks. After a bloom of the cubomedusa Carybdea marsupialis (Carybdeidae) along the coast of Denia (SW Mediterranean, Spain) in 2008 with negative consequences for local tourism, the necessity to understand the ecological restrictions on medusae abundance was evident. Here we use different models (GAM and zero-inflated models) to understand the environmental and human related factors influencing the abundance and distribution of C. marsupialis along the coast of Denia. Selected variables differed among medusae size classes, showing different environmental restriction associated to the developmental stages of the species. Variables implicated with dispersion (e.g. wind and current) affected mostly small and medium size classes. Sea surface temperature, salinity and proxies of primary production (chl a, phosphates, nitrates) were related to the abundances of small and large size classes, highlighting the roles of springtime salinity changes and increased primary production that may promote and maintain high densities of this species. The increased primary (and secondary) production due to anthropogenic impact is implicated as the factor enabling high numbers of C. marsupialis to thrive. Recommendations for monitoring blooms of this species along the study area and applicable to Mediterranean Sea include focus effort in coastal waters where productivity have been enriched by anthropogenic activities.

  10. Green Fluorescence of Cytaeis Hydroids Living in Association with Nassarius Gastropods in the Red Sea.

    Science.gov (United States)

    Prudkovsky, Andrey A; Ivanenko, Viatcheslav N; Nikitin, Mikhail A; Lukyanov, Konstantin A; Belousova, Anna; Reimer, James D; Berumen, Michael L

    2016-01-01

    Green Fluorescent Proteins (GFPs) have been reported from a wide diversity of medusae, but only a few observations of green fluorescence have been reported for hydroid colonies. In this study, we report on fluorescence displayed by hydroid polyps of the genus Cytaeis Eschscholtz, 1829 (Hydrozoa: Anthoathecata: Filifera) found at night time in the southern Red Sea (Saudi Arabia) living on shells of the gastropod Nassarius margaritifer (Dunker, 1847) (Neogastropoda: Buccinoidea: Nassariidae). We examined the fluorescence of these polyps and compare with previously reported data. Intensive green fluorescence with a spectral peak at 518 nm was detected in the hypostome of the Cytaeis polyps, unlike in previous reports that reported fluorescence either in the basal parts of polyps or in other locations on hydroid colonies. These results suggest that fluorescence may be widespread not only in medusae, but also in polyps, and also suggests that the patterns of fluorescence localization can vary in closely related species. The fluorescence of polyps may be potentially useful for field identification of cryptic species and study of geographical distributions of such hydroids and their hosts.

  11. Green Fluorescence of Cytaeis Hydroids Living in Association with Nassarius Gastropods in the Red Sea.

    Directory of Open Access Journals (Sweden)

    Andrey A Prudkovsky

    Full Text Available Green Fluorescent Proteins (GFPs have been reported from a wide diversity of medusae, but only a few observations of green fluorescence have been reported for hydroid colonies. In this study, we report on fluorescence displayed by hydroid polyps of the genus Cytaeis Eschscholtz, 1829 (Hydrozoa: Anthoathecata: Filifera found at night time in the southern Red Sea (Saudi Arabia living on shells of the gastropod Nassarius margaritifer (Dunker, 1847 (Neogastropoda: Buccinoidea: Nassariidae. We examined the fluorescence of these polyps and compare with previously reported data. Intensive green fluorescence with a spectral peak at 518 nm was detected in the hypostome of the Cytaeis polyps, unlike in previous reports that reported fluorescence either in the basal parts of polyps or in other locations on hydroid colonies. These results suggest that fluorescence may be widespread not only in medusae, but also in polyps, and also suggests that the patterns of fluorescence localization can vary in closely related species. The fluorescence of polyps may be potentially useful for field identification of cryptic species and study of geographical distributions of such hydroids and their hosts.

  12. Evidence of Cnidarians sensitivity to sound after exposure to low frequency noise underwater sources

    Science.gov (United States)

    Solé, Marta; Lenoir, Marc; Fontuño, José Manuel; Durfort, Mercè; van der Schaar, Mike; André, Michel

    2016-12-01

    Jellyfishes represent a group of species that play an important role in oceans, particularly as a food source for different taxa and as a predator of fish larvae and planktonic prey. The massive introduction of artificial sound sources in the oceans has become a concern to science and society. While we are only beginning to understand that non-hearing specialists like cephalopods can be affected by anthropogenic noises and regulation is underway to measure European water noise levels, we still don’t know yet if the impact of sound may be extended to other lower level taxa of the food web. Here we exposed two species of Mediterranean Scyphozoan medusa, Cotylorhiza tuberculata and Rhizostoma pulmo to a sweep of low frequency sounds. Scanning electron microscopy (SEM) revealed injuries in the statocyst sensory epithelium of both species after exposure to sound, that are consistent with the manifestation of a massive acoustic trauma observed in other species. The presence of acoustic trauma in marine species that are not hearing specialists, like medusa, shows the magnitude of the problem of noise pollution and the complexity of the task to determine threshold values that would help building up regulation to prevent permanent damage of the ecosystems.

  13. Diversity Dynamics in Nymphalidae Butterflies: Effect of Phylogenetic Uncertainty on Diversification Rate Shift Estimates

    Science.gov (United States)

    Peña, Carlos; Espeland, Marianne

    2015-01-01

    The species rich butterfly family Nymphalidae has been used to study evolutionary interactions between plants and insects. Theories of insect-hostplant dynamics predict accelerated diversification due to key innovations. In evolutionary biology, analysis of maximum credibility trees in the software MEDUSA (modelling evolutionary diversity using stepwise AIC) is a popular method for estimation of shifts in diversification rates. We investigated whether phylogenetic uncertainty can produce different results by extending the method across a random sample of trees from the posterior distribution of a Bayesian run. Using the MultiMEDUSA approach, we found that phylogenetic uncertainty greatly affects diversification rate estimates. Different trees produced diversification rates ranging from high values to almost zero for the same clade, and both significant rate increase and decrease in some clades. Only four out of 18 significant shifts found on the maximum clade credibility tree were consistent across most of the sampled trees. Among these, we found accelerated diversification for Ithomiini butterflies. We used the binary speciation and extinction model (BiSSE) and found that a hostplant shift to Solanaceae is correlated with increased net diversification rates in Ithomiini, congruent with the diffuse cospeciation hypothesis. Our results show that taking phylogenetic uncertainty into account when estimating net diversification rate shifts is of great importance, as very different results can be obtained when using the maximum clade credibility tree and other trees from the posterior distribution. PMID:25830910

  14. Chemische Zusammensetzung und Biomasseparameter der Ohrenqualle Aurelia aurita

    Science.gov (United States)

    Schneider, Gerald

    1988-06-01

    During summer 1982 and 1983, measurements on the chemical composition and biomass parameters of Aurelia aurita from Kiel Fjord, Western Baltic, were made. The relationships between size vs. wet weight and wet weight vs. carbon content were determined. Dry weight accounted for less than 2% of wet weight in both years. Carbon, nitrogen and phosphorus content of whole medusae were 51 52, 14 and 1.4 mg/g dry weight (dw) respectively. The C:N ratio (by weight) was about 3.7 and the C:N:P-ratio (by atoms) was determined to be 94:22:1. Proteins and carbohydrates made up 59 and 29 mg/g dw. Lipids were estimated to be 19 mg/g dw. Using these data, it was possible to calculate the caloric content of the medusae to be about 0.55 cal/mg dw. In summer 1982, the organic content of different tissues (gonad, oral arm, umbrella) in unfertilized and fertilized females was studied. In unfertilized females, the gonads exhibited the highest values, the umbrella had the lowest values and the values of oral arm tissue were intermediate. However, in fertilized females the oral arm tissue was enriched, whereas the gonads were impoverished; both types of tissues exhibited very similar values. This pattern can be explained by the transfer of fertilized eggs from the gonads into the brood pouches of the oral arms.

  15. The physiological and molecular response of Aurelia sp.1 under hypoxia.

    Science.gov (United States)

    Wang, Guoshan; Zhen, Yu; Yu, Zhigang; Shi, Yan; Zhao, Qing; Wang, Jianyan; Mi, Tiezhu

    2017-05-08

    Few studies have been published on the mechanisms of hypoxia response and tolerance in jellyfish, especially with respect to the regulatory mechanism at the molecular level. In this study, Aurelia sp.1, which is frequently found in Chinese coastal waters, was cultivated in a hypoxic system to determine the molecular mechanisms underlying its hypoxic response by studying the physiological activity, gene expression and metabolite contents in the prolyl hydroxylase domain (PHD)-hypoxia inducible factor (HIF) oxygen-sensing system. Physiological activity; the expression of PHD, HIF, ALDO (fructose-bisphosphate aldolase), PDK (pyruvate dehydrogenase kinase), and LDH (lactate dehydrogenase) genes; and the lactic acid content in medusae were significantly affected by hypoxia. The up-regulation of ALDO, PDK and LDH, which was directly or indirectly induced by HIF, mediated the transition from aerobic respiration to anaerobic glycolysis in the medusae. In polyps, there was a slight increase in the expression of HIF, PHD and ALDO, no obvious change in that of PDK and a slight decrease in that of LDH throughout the experiment; however, these changes were insufficient to induce the shift. This study provides a scientific basis for elucidating the regulatory mechanism underlying the PHD-HIF oxygen-sensing system in Aurelia sp.1.

  16. Respiratory response to temperature of three populations of Aurelia aurita polyps in northern Europe.

    Science.gov (United States)

    Höhn, Danja P; Lucas, Cathy H; Thatje, Sven

    2017-01-01

    The benthic life stage (polyp or scyphistoma) of the bloom-forming jellyfish, Aurelia aurita (Linnaeus, 1759), also known as the moon jellyfish, contributes to the seasonal occurrence and abundance of medusa blooms via asexual reproduction. A. aurita is widely distributed in coastal areas in northern Europe, and one of the most studied jellyfish species. While the physiology of the visible medusa is largely understood, understanding of the physiology of the perennial benthic life-stage is scarce. To measure the physiological tolerance of A. aurita, the scyphistoma's temperature sensitivity across its distributional range was investigated. Respiration rates of polyps from three northern European locations exposed to 11 temperatures between 2 and 22°C were measured. There was a significant difference in respiration rate among the three polyp populations, which may reflect on differences in their thermal tolerance window. A critical temperature was reached at 14°C with the metabolic rate decreasing below and above that temperature. This pattern was less pronounced in the Norwegian population but polyps were able to survive, at least temporarily, those temperatures exceeding their natural range. While polyps collected from northern Norway, with a narrow environmental thermal window, displayed a low baseline metabolism with a Q10 value of 1.2, polyps from southern England and Scotland had Q10 values of 1.6 and 2.5, respectively. Differences in polyps' respiration rates across their distributional range suggest that populations have evolved adaptations to local environmental thermal conditions.

  17. El ciclo vital de Zanclea giancarloi Boero, Bouillon Gravili, 2000 (Cnidaria, Hydrozoa, Zancleidae en la costa vasca (SE Golfo de Vizcaya, Atlántico NE.

    Directory of Open Access Journals (Sweden)

    ALTUNA, A.

    2013-01-01

    Full Text Available Se ha obtenido en la costa vasca (Golfo de Vizcaya, España, Atlántico nororiental el hidrozoo Zanclea giancarloi Boero, Bouillon Gravili, 2000, que era conocido únicamente de unas pocas citas en el Mediterráneo francés e italiano. El pólipo se ha cultivado en laboratorio hasta la obtención de medusas masculinas adultas, que se describen por vez primera. La medusa presenta una vida muy corta. Se libera del pólipo, madura en 8-10 días en los que apenas aumenta de tamaño, y muere. En los pólipos, y a diferencia del material tipo, sólo se han observado euriteles macrobásicos con espinas en 1/5 de la longitud del tubo descargado, y el hipostoma muestra un patrón estrellado de color blanco. La especie ha sido hallada en 2006 en una estación habitual de muestreo por el autor desde 1982, discutiéndose una posible relación entre su presencia y el calentamiento excepcional del agua marina en los años 2003–2006.

  18. Podocoryna martinicana, a new species of athecate hydroid (Cnidaria: Hydrozoa: Hydractiniidae) from the Caribbean.

    Science.gov (United States)

    Galea, Horia R; Ferry, Romain

    2013-01-01

    A new species of hydroid, Podocoryna martinicana sp. nov., is described from the Lesser Antilles. It lives symbiotically with Iridopagurus caribbensis (A. Milne-Edwards & Bouvier, 1893) (Decapoda: Paguridae) inhabiting various gastropod shells. Its colonies are highly organized and develop exclusively around the aperture of the host shell. A few large, columnar gastrozooids provided with numerous tentacles arise from a perisarc-covered stolonal mat on the inner lip of the shell, and appear to form a gate when the hermit is withdrawn, while numerous, small, highly prolific gonozooids dress a line on the edge of the outer lip. Slender, very contractile tentaculozooids occur variably among the colonies. The dispersive stage, a free-swimming medusa with four well-developed marginal tentacles and no ocelli, is solely described based on young, sexually immature specimens. The species is further characterized by the peculiar bright white tinge of the core of both hydroid and medusa tentacles. Rich illustrations, data on the nematocyst complement, as well as comparisons with related congeners are provided.

  19. Reproductive biology and variation of nuclear ribosomal ITS and ETS sequences in the Calligonum mongolicum complex (Polygonaceae).

    Science.gov (United States)

    Shi, Wei; Wen, Jun; Zhao, Yanfeng; Johnson, Gabriel; Pan, Borong

    2017-01-01

    To explore the biosystematics of the Calligonum mongolicum complex (Polygonaceae), the flowering phenological period, breeding and pollination characters and seed set of the complex (Calligonum Mongolicum Turze, Calligonum chinense A. Los., Calligonum gobicum A. Los., Calligonum pumilum A. Los. and Calligonum zaidamense A. Los.) were documented in the Turpan Eremophyte Botanical Garden, China. The sequences of the nuclear ribosomal ITS and ETS region were employed to differentiate the Calligonum mongolicum complex and other species in sect. Medusae. The results showed species of the Calligonum mongolicum complex occupied overlapping flowering periods and had consistent pollination agents. Their breeding systems are all self-compatible, tend to be out-crossing and they interbreed amongst each other (out-crossing index, OCI = 4).The crosses within and amongst species had high seed sets (44 - 65%). Phylogenetic analyses of Calligonum sect. Medusae and the network analysis of nrDNA (ITS and ETS) in the complex suggest interbreeding amongst "species" within the complex and provide evidence for taxonomically merging the five species in the complex. The detected hybridisation, occurring within the complex, suggests the need to improve traditional methods of ex situ plant conservation in botanical gardens for maintaining genetic diversity of Calligonum within and amongst species from different geographic areas.

  20. Early Cambrian wave-formed shoreline deposits: the Hardeberga Formation, Bornholm, Denmark

    Science.gov (United States)

    Clemmensen, Lars B.; Glad, Aslaug C.; Pedersen, Gunver K.

    2017-09-01

    During the early Cambrian, the Danish island Bornholm was situated on the northern edge of the continent Baltica with palaeolatitudes of about 35°S. An early Cambrian (Terreneuvian) transgression inundated large areas of Baltica including Bornholm creating shallow marine and coastline environments. During this period, wave-formed shoreline sediments (the Vik Member, Hardeberga Formation) were deposited on Bornholm and are presently exposed at Strøby quarry. The sediments consist of fine- and medium-grained quartz-cemented arenites in association with a few silt-rich mudstones. The presence of well-preserved subaqueous dunes and wave ripples indicates deposition in a wave-dominated upper shoreface (littoral zone) environment, and the presence of interference ripples indicates that the littoral zone environment experienced water level fluctuations due to tides and/or changing meteorological conditions. Discoidal structures (medusoids) are present in the quarry, but due to the relative poor preservation of their fine-scale structures it is difficult to determine if the discoids represent true medusae imprints or inorganic structures. The preservation of the shallow-water bedforms as well as the possible medusae imprints is related to either the formation of thin mud layers, formed during a period of calm water when winds blew offshore for a longer period, or to the growth of bacterial mats. The orientation of the wave-formed bedforms indicates a local palaeoshoreline trending NE-SW and facing a large ocean to the north.

  1. Field and Laboratory Observations on Predation and Prey Selectivity of the Scyphomedusa Chrysaora cf.caliparea in Southeast Indian Waters

    Institute of Scientific and Technical Information of China (English)

    Govindan Kanagaraj; Pazhaniyappan Ezhilarasan; Pitchai Sampathkumar; André C. Morandini; Velayudhan pillai Sivakumar

    2011-01-01

    Chrysaora cf. caliparea, one of the most abundant medusae species in India, seems to be an important predator in the coastal waters of Bay of Bengal. The ability of Chrysaora cf. caliparea to feed at maximum rate in high prey concentrations implies that this jellyfish can efficiently exploit dense prey patches, at least for a short period. This study presents preliminary information regarding digestion and feeding rate upon copepods in a warm water environment. The ingestion rate of the average-sized medusae Chrysaora cf. caliparea is well balanced in nature, which in turn implies that this jellyfish is tuned for optimal utilization of available prey resources. Comparison with earlier research indicates that prey escape speed is one important factor governing which prey will be captured. A full understanding of predation mechanics awaits further investigation of both predator and prey behavior. However, because of the scarcity of long-term quantitative population data most insights have to be made indirectly. Nevertheless, low abundance of Chrysaora cf. caliparea in the water column during summer (May 2007) and the overall annual abundance seem not to considerably affect the zooplankton population, especially copepods. The present work contributes to the knowledge of prey-predator relationship of the forgotten fauna in Indian waters, which is especially crucial for understanding the process of ecological recovery of coastal water environment.

  2. Propulsion in cubomedusae: mechanisms and utility.

    Directory of Open Access Journals (Sweden)

    Sean P Colin

    Full Text Available Evolutionary constraints which limit the forces produced during bell contractions of medusae affect the overall medusan morphospace such that jet propulsion is limited to only small medusae. Cubomedusae, which often possess large prolate bells and are thought to swim via jet propulsion, appear to violate the theoretical constraints which determine the medusan morphospace. To examine propulsion by cubomedusae, we quantified size related changes in wake dynamics, bell shape, swimming and turning kinematics of two species of cubomedusae, Chironex fleckeri and Chiropsella bronzie. During growth, these cubomedusae transitioned from using jet propulsion at smaller sizes to a rowing-jetting hybrid mode of propulsion at larger sizes. Simple modifications in the flexibility and kinematics of their velarium appeared to be sufficient to alter their propulsive mode. Turning occurs during both bell contraction and expansion and is achieved by generating asymmetric vortex structures during both stages of the swimming cycle. Swimming characteristics were considered in conjunction with the unique foraging strategy used by cubomedusae.

  3. Comprehensive analysis of the origin of giant jellyfish near Qinhuangdao in summer

    Science.gov (United States)

    Wu, Lingjuan; Wu, Xiaofen; Bai, Tao

    2016-09-01

    A massive bloom of the giant jellyfish Nemopilema nomurai occurred in waters off Qinhuangdao, a port city in Hebei Province, in July 2013. However, jellyfish larvae were not found in this location during the previous winter and spring. To determine the possible origin of the giant jellyfish medusa in the Bohai Sea, we developed a backward particle-tracking model and a series of numerical simulations were conducted by using the hydrodynamic, three-dimensional Regional Ocean Modeling System (ROMS) results. The simulated results showed that passive particles, representing jellyfish medusae, released in surface waters at diff erent dates during the summer had consistent trajectories. Particles released at the sea surface on August 1 and 15 could be traced back to the center of the Bohai Sea and to waters between Feiyan Shoal and the new Huanghe (Yellow) River estuary. Particles released on July 1 and 15 could also be traced back to the center of the Bohai Sea and to waters between Feiyan Shoal and only to Zhuangxi tide station. However, none of the particles released in the middle and bottom water layers could be traced back to those areas. Based on the results of the numerical simulations, the distribution characteristics of seafloor sediments, and observational data for giant jellyfish in the region, we suggest that waters between Feiyan Shoal and the new Huanghe River estuary are the likely origin of giant jellyfish observed near Qinhuangdao in summer.

  4. Early Cambrian wave-formed shoreline deposits: the Hardeberga Formation, Bornholm, Denmark

    Science.gov (United States)

    Clemmensen, Lars B.; Glad, Aslaug C.; Pedersen, Gunver K.

    2016-09-01

    During the early Cambrian, the Danish island Bornholm was situated on the northern edge of the continent Baltica with palaeolatitudes of about 35°S. An early Cambrian (Terreneuvian) transgression inundated large areas of Baltica including Bornholm creating shallow marine and coastline environments. During this period, wave-formed shoreline sediments (the Vik Member, Hardeberga Formation) were deposited on Bornholm and are presently exposed at Strøby quarry. The sediments consist of fine- and medium-grained quartz-cemented arenites in association with a few silt-rich mudstones. The presence of well-preserved subaqueous dunes and wave ripples indicates deposition in a wave-dominated upper shoreface (littoral zone) environment, and the presence of interference ripples indicates that the littoral zone environment experienced water level fluctuations due to tides and/or changing meteorological conditions. Discoidal structures (medusoids) are present in the quarry, but due to the relative poor preservation of their fine-scale structures it is difficult to determine if the discoids represent true medusae imprints or inorganic structures. The preservation of the shallow-water bedforms as well as the possible medusae imprints is related to either the formation of thin mud layers, formed during a period of calm water when winds blew offshore for a longer period, or to the growth of bacterial mats. The orientation of the wave-formed bedforms indicates a local palaeoshoreline trending NE-SW and facing a large ocean to the north.

  5. Reproductive biology and variation of nuclear ribosomal ITS and ETS sequences in the Calligonum mongolicum complex (Polygonaceae

    Directory of Open Access Journals (Sweden)

    Wei Shi

    2017-01-01

    Full Text Available To explore the biosystematics of the Calligonum mongolicum complex (Polygonaceae, the flowering phenological period, breeding and pollination characters and seed set of the complex (C. Mongolicum Turze, C. chinense A. Los., C. gobicum A. Los., C. pumilum A. Los. and C. zaidamense A. Los. were documented in the Turpan Eremophyte Botanical Garden, China. The sequences of the nuclear ribosomal ITS and ETS region were employed to differentiate the C. mongolicum complex and other species in sect. Medusae. The results showed species of the C. mongolicum complex occupied overlapping flowering periods and had consistent pollination agents. Their breeding systems are all self-compatible, tend to be out-crossing and they interbreed amongst each other (out-crossing index, OCI = 4.The crosses within and amongst species had high seed sets (44 - 65%. Phylogenetic analyses of Calligonum sect. Medusae and the network analysis of nrDNA (ITS and ETS in the complex suggest interbreeding amongst “species” within the complex and provide evidence for taxonomically merging the five species in the complex. The detected hybridisation, occurring within the complex, suggests the need to improve traditional methods of ex situ plant conservation in botanical gardens for maintaining genetic diversity of Calligonum within and amongst species from different geographic areas.

  6. Diversity dynamics in Nymphalidae butterflies: effect of phylogenetic uncertainty on diversification rate shift estimates.

    Directory of Open Access Journals (Sweden)

    Carlos Peña

    Full Text Available The species rich butterfly family Nymphalidae has been used to study evolutionary interactions between plants and insects. Theories of insect-hostplant dynamics predict accelerated diversification due to key innovations. In evolutionary biology, analysis of maximum credibility trees in the software MEDUSA (modelling evolutionary diversity using stepwise AIC is a popular method for estimation of shifts in diversification rates. We investigated whether phylogenetic uncertainty can produce different results by extending the method across a random sample of trees from the posterior distribution of a Bayesian run. Using the MultiMEDUSA approach, we found that phylogenetic uncertainty greatly affects diversification rate estimates. Different trees produced diversification rates ranging from high values to almost zero for the same clade, and both significant rate increase and decrease in some clades. Only four out of 18 significant shifts found on the maximum clade credibility tree were consistent across most of the sampled trees. Among these, we found accelerated diversification for Ithomiini butterflies. We used the binary speciation and extinction model (BiSSE and found that a hostplant shift to Solanaceae is correlated with increased net diversification rates in Ithomiini, congruent with the diffuse cospeciation hypothesis. Our results show that taking phylogenetic uncertainty into account when estimating net diversification rate shifts is of great importance, as very different results can be obtained when using the maximum clade credibility tree and other trees from the posterior distribution.

  7. Radon soil-gas concentration and exhalation from mine tailings dams in South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Ongori, J.; Lindsay, R. [University of the Western Cape, Department of Physics, Private Bag X17, Bellville 7535 (South Africa); Newman, R. [Stellenbosch University, Department of Physics, Private Bag X1 Matieland 7602 (South Africa); Maleka, P. [iThemba LABS, Department of Nuclear Physics, P. O. Box 722, Somerset West 7129 (South Africa)

    2014-07-01

    , temperature, moisture and atmospheric pressure influence radon exhalation. At Kloof mine dump radon exhalation was mapped using a novel technique by means of a MEDUSA (Multi-Element Detector for Underwater Sediment Activity) gamma-ray detection system. The MEDUSA detector uses a CsI(Na) crystal and was mounted on the front of a 4x4 vehicle, 0.6 m off the ground. With this setup the MEDUSA detector measures the average activity concentration in the top 30 cm when accessible parts are traversed. The spectra acquired by the MEDUSA system were analysed and the activity concentrations for {sup 238}U, {sup 40}K and {sup 232}Th, were extracted using the Full Spectrum Analysis approach. Radon exhalation from a particular location in the mine dump was obtained by comparing the ratios of the activity concentrations of the {sup 214}Bi obtained in the field using the MEDUSA gamma-ray detector system to the activity concentrations of the {sup 214}Bi obtained in the laboratory using the HPGe gamma-ray detector system. In this case it is assumed that the {sup 40}K and {sup 232}Th series activity concentrations are not or hardly affected by radon exhalation. The application of this new technique gave an average normalised radon flux of 0.12±0.02 Bq.m{sup -2}.s{sup -1} for the mine dump. Document available in abstract form only. (authors)

  8. Genetic diversity of populations and clones of Rhopilema esculentum in China based on AFLP analysis

    Institute of Scientific and Technical Information of China (English)

    QIAO Hongjin; LIU Xiangquan; ZHANG Xijia; JIANG Haibin; WANG Jiying; ZHANG Limin

    2013-01-01

    Amplified fragment length polymorphisms (AFLP) markers were developed to assess the genetic variation of populations and clones of Rhopilema esculentum Kishinouye (Scyphozoa,Rhizostomatidae).One hundred and seventy-nine loci from 56 individuals of two hatchery populations and two wild populations were genotyped with five primer combinations.The polymorphic ratio,Shannon's diversity index and average heterozygosity were 70.3%,0.346 and 0.228 for the white hatchery population,74.3%,0.313,and 0.201 for the red hatchery population,79.3%,0.349,and 0.224 for the Jiangsu wild population,and 74.9%,0.328 and 0.210 for the Penglai wild population,respectively.Thus,all populations had a relatively high level of genetic diversity.A specific band was identified that could separate the white from the red hatchery population.There was 84.85% genetic differentiation within populations.Individual cluster analysis using unweighted pair-group method with arithmetic mean (UPGMA) suggested that hatchery populations and wild populations could be divided.For the hatchery populations,the white and red populations clustered separately; however,for the wild populations,Penglai and Jiangsu populations clustered together.The genetic diversity at the clone level was also determined.Our data suggest that there are relatively high genetic diversities within populations but low genetic differentiation between populations,which may be related to the long-term use of germplasm resources from Jiangsu Province for artificial seeding and releasing.These findings will benefit the artificial seeding and conservation of the germplasm resources.

  9. Evolution of linear mitochondrial genomes in medusozoan cnidarians.

    Science.gov (United States)

    Kayal, Ehsan; Bentlage, Bastian; Collins, Allen G; Kayal, Mohsen; Pirro, Stacy; Lavrov, Dennis V

    2012-01-01

    In nearly all animals, mitochondrial DNA (mtDNA) consists of a single circular molecule that encodes several subunits of the protein complexes involved in oxidative phosphorylation as well as part of the machinery for their expression. By contrast, mtDNA in species belonging to Medusozoa (one of the two major lineages in the phylum Cnidaria) comprises one to several linear molecules. Many questions remain on the ubiquity of linear mtDNA in medusozoans and the mechanisms responsible for its evolution, replication, and transcription. To address some of these questions, we determined the sequences of nearly complete linear mtDNA from 24 species representing all four medusozoan classes: Cubozoa, Hydrozoa, Scyphozoa, and Staurozoa. All newly determined medusozoan mitochondrial genomes harbor the 17 genes typical for cnidarians and map as linear molecules with a high degree of gene order conservation relative to the anthozoans. In addition, two open reading frames (ORFs), polB and ORF314, are identified in cubozoan, schyphozoan, staurozoan, and trachyline hydrozoan mtDNA. polB belongs to the B-type DNA polymerase gene family, while the product of ORF314 may act as a terminal protein that binds telomeres. We posit that these two ORFs are remnants of a linear plasmid that invaded the mitochondrial genomes of the last common ancestor of Medusozoa and are responsible for its linearity. Hydroidolinan hydrozoans have lost the two ORFs and instead have duplicated cox1 at each end of their mitochondrial chromosome(s). Fragmentation of mtDNA occurred independently in Cubozoa and Hydridae (Hydrozoa, Hydroidolina). Our broad sampling allows us to reconstruct the evolutionary history of linear mtDNA in medusozoans.

  10. Inbreeding and genetic diversity analysis in a hatchery release population and clones of Rhopilema esculentum based on microsatellite markers

    Science.gov (United States)

    Tian, Tao; Chen, Zaizhong; Wang, Mosang; Hu, Yulong; Wang, Weiji

    2017-05-01

    Ten microsatellite markers were used to analyze the levels of genetic diversity and inbreeding in a hatchery release population of Rhopilema esculentum Kishinouye (Scyphozoa: Rhizostomatidae). A total of 85 alleles were detected in 600 individuals. Within-population levels of observed ( H o) and expected ( H e) heterozygosity ranged from 0.152 to 0.839 (mean=0.464) and from 0.235 to 0.821 (mean=0.618), respectively. The polymorphism information content (PIC) of each marker ranged from 0.207 to 0.795 with an average of 0.580, indicating that the hatchery population maintained a high level of genetic diversity. Inbreeding levels were estimated in the hatchery population and the inbreeding coefficient was 0.203. This result revealed that a certain level of inbreeding occurred within the population. Meanwhile, we also determined genetic diversity at the clone level. Several polyps from the same scyphistomae were genotyped at the ten microsatellite loci and there was virtually no difference in their genotypes. Furthermore, we calculated the probabilities of exclusion. When both parents were known, the average exclusion probability of ten loci was 99.99%. Our data suggest that the ten microsatellite markers can not only be used to analyze the identity of individuals but they can also be applied to parentage identification. Our research provides a theoretical basis and technical support for genetic diversity detection and reasonable selection of R. esculentum hatchery populations. These findings support the use of releasing studies and conservation of R. esculentum germplasm resources.

  11. Inbreeding and genetic diversity analysis in a hatchery release population and clones of Rhopilema esculentum based on microsatellite markers

    Science.gov (United States)

    Tian, Tao; Chen, Zaizhong; Wang, Mosang; Hu, Yulong; Wang, Weiji

    2016-07-01

    Ten microsatellite markers were used to analyze the levels of genetic diversity and inbreeding in a hatchery release population of Rhopilema esculentum Kishinouye (Scyphozoa: Rhizostomatidae). A total of 85 alleles were detected in 600 individuals. Within-population levels of observed (H o) and expected (H e) heterozygosity ranged from 0.152 to 0.839 (mean=0.464) and from 0.235 to 0.821 (mean=0.618), respectively. The polymorphism information content (PIC) of each marker ranged from 0.207 to 0.795 with an average of 0.580, indicating that the hatchery population maintained a high level of genetic diversity. Inbreeding levels were estimated in the hatchery population and the inbreeding coefficient was 0.203. This result revealed that a certain level of inbreeding occurred within the population. Meanwhile, we also determined genetic diversity at the clone level. Several polyps from the same scyphistomae were genotyped at the ten microsatellite loci and there was virtually no difference in their genotypes. Furthermore, we calculated the probabilities of exclusion. When both parents were known, the average exclusion probability of ten loci was 99.99%. Our data suggest that the ten microsatellite markers can not only be used to analyze the identity of individuals but they can also be applied to parentage identification. Our research provides a theoretical basis and technical support for genetic diversity detection and reasonable selection of R. esculentum hatchery populations. These findings support the use of releasing studies and conservation of R. esculentum germplasm resources.

  12. protective effect of tetracycline against dermal toxicity induced by Jellyfish venom.

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    Changkeun Kang

    Full Text Available BACKGROUND: Previously, we have reported that most, if not all, of the Scyphozoan jellyfish venoms contain multiple components of metalloproteinases, which apparently linked to the venom toxicity. Further, it is also well known that there is a positive correlation between the inflammatory reaction of dermal tissues and their tissue metalloproteinase activity. Based on these, the use of metalloproteinase inhibitors appears to be a promising therapeutic alternative for the treatment of jellyfish envenomation. METHODOLOGY AND PRINCIPAL FINDINGS: Tetracycline (a metalloproteinase inhibitor has been examined for its activity to reduce or prevent the dermal toxicity induced by Nemopilema nomurai (Scyphozoa: Rhizostomeae jellyfish venom (NnV using in vitro and in vivo models. HaCaT (human keratinocyte and NIH3T3 (mouse fibroblast incubated with NnV showed decreases in cell viability, which is associated with the inductions of metalloproteinase-2 and -9. This result suggests that the use of metalloproteinase inhibitors, such as tetracycline, may prevent the jellyfish venom-mediated local tissue damage. In vivo experiments showed that comparing with NnV-alone treatment, tetracycline pre-mixed NnV demonstrated a significantly reduced progression of dermal toxicity upon the inoculation onto rabbit skin. CONCLUSIONS/SIGNIFICANCE: It is believed that there has been no previous report on the therapeutic agent of synthetic chemical origin for the treatment of jellyfish venom-induced dermonecrosis based on understanding its mechanism of action except the use of antivenom treatment. Furthermore, the current study, for the first time, has proposed a novel mechanism-based therapeutic intervention for skin damages caused by jellyfish stings.

  13. Preliminary assessment of the jellyfish bycatch captured off southern and southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Rafael Schroeder

    2014-05-01

    Full Text Available Macromedusoid forms of Hydrozoa, Scyphozoa and Cubozoa captured by different fishing gears active in south and southeast of Brazil were recorded on board by scientific observers. After each fishing operation, catch composition was quantified and precise information about the position of the catch was taken between 2008 and 2011. Macromedusae records have been systemized in order to analyze the spatial-temporal distribution, the areas of concentration of the identified species and their relationship with other components of the bycatch. Catch composition analyzed in 986 fishing tows, demonstrated that the participation of these organisms ranged from 6-16%, and the hydromedusae Rhacostoma atlanticum L. Agassiz, 1851 and Olindias sambaquiensis Müller, 1861 were the most abundant and widely distributed species. R. atlanticum was recorded between 20 and 140 m deep while O. sambaquiensis presented registers in shallower waters between 10 and 70 m. No other identified species has been recorded in depths greater than 60 m. Areas of high concentration included the north-central coast of Santa Catarina and Paraná, the northern part of São Paulo and the north-central portion of Rio Grande do Sul State. Although the participation of the macromedusae has been relatively low, in areas of elevated concentration, the relative importance was high, making its participation almost exclusive among other zoological groups. Those registers of abundance and the respective areas of high concentration of macromedusae, which were associated to high primary production sites, may serve as a theoretical reference of the abundance of these organisms for future studies that aim to evaluate possible changes in jellyfish populations.

  14. Navodon septentrionalis Predation of Four Species of Giant Jellyfish%绿鳍马面鲀(Navodon septentrionalis)对4种大型水母的捕食行为

    Institute of Scientific and Technical Information of China (English)

    刘春胜; 庄志猛; 陈四清; 刘长琳; 赵鹏; 陈昭廷

    2014-01-01

    以绿鳍马面鲀为研究对象,通过室内受控实验,比较研究了其对我国沿海4种常见大型水母(海蜇、沙海蜇、海月水母和白色霞水母)的捕食差异。结果显示,体重为(215±20) g的绿鳍马面鲀对海月水母的捕食能力最强,日均最大摄食量为(150.7±18.6) g/fish,其次是海蜇和白色霞水母,日均摄食量分别为(129.7±11.6)和(120.0±19.3) g/fish,对沙海蜇的摄食量最少,为(92.5±11.3) g/fish;绿鳍马面鲀对海月水母与海蜇摄食量主要受投喂量影响,与规格无关,当投喂量小于其最大捕食量时,绿鳍马面鲀可捕食其周围所有水母,当投喂量超过其最大摄食量并继续增加时,绿鳍马面鲀摄食量保持不变,但残余水母的触手和伞部边缘均被啃食,继而导致水母摄食能力丧失,难以继续生存;在适口饵料冰鲜玉筋鱼充足的情况下,绿鳍马面鲀对水母具有明显的摄食偏向性,与仅投喂水母实验组相比,其对海月水母和海蜇的日均摄食量仅降低了20.2%和16.9%。研究结果表明,绿鳍马面鲀对上述4种水母皆能捕食。%The predatory behavior of filefish Navodon septentrionalis to Aurelia aurita was observed before. Here we hypothesized that there were also predator-prey relationships between filefish and other jellyfish species. We explored the predatory behaviors of filefish to four species of giant jellyfish, including Rhopilema esculentum, Nemopilema nomurai, A. aurita and Cyanea nozakii, under laboratory conditions. We also studied the prey selection of filefish among jellyfish species of R. esculentum and A. aurita, and sand lance. Filefish weighted (215±20) g actively preyed on all four jellyfish species, and its daily medusae consumption of A. aurita, R. esculentum, C. nozakii, and N. nomurai was 150.7±18.6, 129.7±11.6, 120.0±19.3, and 92.5±11.3 g/fish respectively. It was the medusae biomass, not the bell diameter that

  15. A NATIONAL SURVEY TO IDENTIFY HOW DISPLACEMENT VALUE INFORMATION IS USED AND PRESENTED TO CLINICAL STAFF IN NHS HOSPITALS.

    Science.gov (United States)

    Christiansen, Nanna; Kehk, Zinab; Keeling, Susan; Dean, Bryony

    2016-09-01

    The use of displacement values (DVs) when preparing intravenous (IV) medication for children enables accurate doses to be given1 and is assumed to be common paediatric practice. This survey aimed to assess views of UK paediatric pharmacists on DVs in practice to explore:▸ How prevalent is DV use in the paediatric hospital setting▸ Which type of IV administration guidelines were being used▸ Which form of DV presentation is perceived to be most practical▸ Which method of calculation is preferred A national cross-sectional survey study was undertaken. The questionnaire comprised of 13 closed and open questions as well as samples of how DVs are currently displayed on the Medusa Injectable Medicines Guide2. After piloting the questionnaire the survey was sent to 365 paediatric pharmacists across 120 UK hospitals utilising Qualtrics Survey Software. Fifty-five completed questionnaires covering 52 (43%) United Kingdom (UK) hospital trusts were received. Of 55 respondents, 52 (95%) reported the clinical significance of DVs in paediatric care. This was reflected in the fact that all local guides provided information on DVs. The majority (32;59%) used locally produced guides, while 15 (27%) of respondents used Medusa as a resource. All respondents commented on methods of presentation and calculation of DV information. Of four methods presented, the method involving presentation of reconstitution information in a brand-specific table was ranked as most practical (46;84% respondents). This method was viewed as being clear and concise. Respondents also expressed the importance of having this tabulated method visually embedded in the monograph to allow easy access to information on the wards. This concurs with suggested information presentation to aid error reduction in the literature.3 National standardisation of DV information was viewed as 'very useful' or 'preferred' by 52 (95%) of respondents; reasons for this preference were risk reduction due to errors or

  16. Determining the radon exhalation rate from a gold mine tailings dump by measuring the gamma radiation.

    Science.gov (United States)

    Ongori, Joash N; Lindsay, Robert; Newman, Richard T; Maleka, Peane P

    2015-02-01

    The mining activities taking place in Gauteng province, South Africa have caused millions of tons of rocks to be taken from underground to be milled and processed to extract gold. The uranium bearing tailings are placed in an estimated 250 dumps covering a total area of about 7000 ha. These tailings dumps contain considerable amounts of radium and have therefore been identified as large sources of radon. The size of these dumps make traditional radon exhalation measurements time consuming and it is difficult to get representative measurements for the whole dump. In this work radon exhalation measurements from the non-operational Kloof mine dump have been performed by measuring the gamma radiation from the dump fairly accurately over an area of more than 1 km(2). Radon exhalation from the mine dump have been inferred from this by laboratory-based and in-situ gamma measurements. Thirty four soil samples were collected at depths of 30 cm and 50 cm. The weighted average activity concentrations in the soil samples were 308 ± 7 Bq kg(-1), 255 ± 5 Bq kg(-1) and 18 ± 1 Bq kg(-1) for (238)U, (40)K and (232)Th, respectively. The MEDUSA (Multi-Element Detector for Underwater Sediment Activity) γ-ray detection system was used for field measurements. The radium concentrations were then used with soil parameters to obtain the radon flux using different approaches such as the IAEA (International Atomic Energy Agency) formula. Another technique the MEDUSA Laboratory Technique (MELT) was developed to map radon exhalation based on (1) recognising that radon exhalation does not affect (40)K and (232)Th activity concentrations and (2) that the ratio of the activity concentration of the field (MEDUSA) to the laboratory (HPGe) for (238)U and (40)K or (238)U and (232)Th will give a measure of the radon exhalation at a particular location in the dump. The average, normalised radon flux was found to be 0.12 ± 0.02 Bq m(-2) s(-1) for the mine dump.

  17. Semantic Assembly and Annotation of Draft RNAseq Transcripts without a Reference Genome.

    Science.gov (United States)

    Ptitsyn, Andrey; Temanni, Ramzi; Bouchard, Christelle; Anderson, Peter A V

    2015-01-01

    Transcriptomes are one of the first sources of high-throughput genomic data that have benefitted from the introduction of Next-Gen Sequencing. As sequencing technology becomes more accessible, transcriptome sequencing is applicable to multiple organisms for which genome sequences are unavailable. Currently all methods for de novo assembly are based on the concept of matching the nucleotide context overlapping between short fragments-reads. However, even short reads may still contain biologically relevant information which can be used as hints in guiding the assembly process. We propose a computational workflow for the reconstruction and functional annotation of expressed gene transcripts that does not require a reference genome sequence and can be tolerant to low coverage, high error rates and other issues that often lead to poor results of de novo assembly in studies of non-model organisms. We start with either raw sequences or the output of a context-based de novo transcriptome assembly. Instead of mapping reads to a reference genome or creating a completely unsupervised clustering of reads, we assemble the unknown transcriptome using nearest homologs from a public database as seeds. We consider even distant relations, indirectly linking protein-coding fragments to entire gene families in multiple distantly related genomes. The intended application of the proposed method is an additional step of semantic (based on relations between protein-coding fragments) scaffolding following traditional (i.e. based on sequence overlap) de novo assembly. The method we developed was effective in analysis of the jellyfish Cyanea capillata transcriptome and may be applicable in other studies of gene expression in species lacking a high quality reference genome sequence. Our algorithms are implemented in C and designed for parallel computation using a high-performance computer. The software is available free of charge via an open source license.

  18. Molecular phylogenetic investigations of the Viviparidae (Gastropoda: Caenogastropoda) in the lakes of the Rift Valley area of Africa.

    Science.gov (United States)

    Sengupta, Mita E; Kristensen, Thomas K; Madsen, Henry; Jørgensen, Aslak

    2009-09-01

    The freshwater gastropod family Viviparidae is nearly cosmopolitan, but absent from South America. On the African continent, two genera are recognized; the widespread Bellamya and the monotypic Neothauma, which is confined to Lake Tanganyika. Most of the African Bellamya species are confined to the major lakes of the Rift Valley area in Africa, i.e. Lake Albert, Lake Malawi, Lake Mweru, and Lake Victoria. The phylogenetic analyses of mitochondrial (COI and 16S) and nuclear (H3, 18S and 28S) DNA inferred three major lake-clades; i.e. Lake Victoria/Kyoga/Albert, Lake Malawi and Lake Mweru/Bangweulu. The endemic B. rubicunda from Lake Albert and B. unicolor from Lake Kyoga were inferred to be part of the Lake Victoria clade. Bellamya capillata as identified by shell characters was polyphyletic in gene trees. The monophyletic Bellamya species radiation in Lake Malawi was most nearly related to the Lake Victoria/Kyoga/Albert-clade. Taxa from the Zambian lakes, Mweru and Bangweulu, were inferred together and placed ancestral to the other lakes. Neothauma tanganyicense was inferred as the sister-group to the Zambian Bellamya. Within the lake-clades the endemic radiations show very low genetic diversities (0-4.1% in COI), suggesting much faster morphological divergence than molecular divergence. Alternatively, Bellamya in Africa constitutes only a few species with several sub-species or eco-phenotypic morphs. The African viviparids were inferred to be the sister-group to a clade comprising Asian species, and the relatively low genetic diversity between the clades (12.6-15.5% in COI) makes a recent Miocene dispersal event from Asia to Africa much more likely than an ancient Gondwana vicarience distribution.

  19. Effect of sub-lethal exposure to ultraviolet radiation on the escape performance of Atlantic cod larvae (Gadus morhua.

    Directory of Open Access Journals (Sweden)

    Yuichi Fukunishi

    Full Text Available The amount of ultraviolet (UV radiation reaching the earth's surface has increased due to depletion of the ozone layer. Several studies have reported that UV radiation reduces survival of fish larvae. However, indirect and sub-lethal impacts of UV radiation on fish behavior have been given little consideration. We observed the escape performance of larval cod (24 dph, SL: 7.6±0.2 mm; 29 dph, SL: 8.2±0.3 mm that had been exposed to sub-lethal levels of UV radiation vs. unexposed controls. Two predators were used (in separate experiments: two-spotted goby (Gobiusculus flavescens; a suction predator and lion's mane jellyfish (Cyanea capillata; a "passive" ambush predator. Ten cod larvae were observed in the presence of a predator for 20 minutes using a digital video camera. Trials were replicated 4 times for goby and 5 times for jellyfish. Escape rate (total number of escapes/total number of attacks ×100, escape distance and the number of larvae remaining at the end of the experiment were measured. In the experiment with gobies, in the UV-treated larvae, both escape rate and escape distance (36%, 38±7.5 mm respectively were significantly lower than those of control larvae (75%, 69±4.7 mm respectively. There was a significant difference in survival as well (UV: 35%,63%. No apparent escape response was observed, and survival rate was not significantly different, between treatments (UV: 66%,74% in the experiment with jellyfish. We conclude that the effect and impact of exposure to sub-lethal levels of UV radiation on the escape performance of cod larvae depends on the type of predator. Our results also suggest that prediction of UV impacts on fish larvae based only on direct effects are underestimations.

  20. El mundo del libro: septiembre de 1964

    Directory of Open Access Journals (Sweden)

    Agustín Rodríguez Garavito

    1964-09-01

    Full Text Available El documento presenta las reseñas de los siguientes títulos: Los pasos en la sombra -Por Helcías Martán Góngora -Poesía- Ediciones Medusa. Colombia. Diccionario Biográfico de Artistas delNuevo Reino de Granada - Edición: Instituto Colombiano de Cultura Hispánica. Bogotá. Artículos y Ensayos -Por José Joaquín Vargas Valdés -Introducción y Selección de Aníbal Vargas Barón -Universidad de Oregón. U.S.A. De lo celeste y tenebroso -Gabriel Uliosa -Poemas- Editorial Iqueima. San Andrés y Providencia -James J. Parsons. -Talleres Gráficos del Banco de la República -Bogotá-Colombia

  1. VizieR Online Data Catalog: NGC 2808 AGB and RGB stars Na abundance (Wang+, 2016)

    Science.gov (United States)

    Wang, Y.; Primas, F.; Charbonnel, C.; van der Swaelmen, M.; Bono, G.; Chantereau, W.; Zhao, G.

    2016-05-01

    The high-resolution spectra of our sample of AGB and RGB stars in the Galactic globular cluster NGC 2808 were obtained with the high-resolution multi-object spectrograph FLAMES, mounted on ESO/VLT-UT2. A combined mode was used where the brightest five objects was observed with UVES-fibre and the remaining targets with GIRAFFE/Medusa. The basic information of our sample stars are listed in Table 2, including the evolutionary phase, instrument used for observation, coordinates, photometry and barycentric radial velocity. Our Fe abundances were derived from the equivalent widths of Fe lines, while the Na abundances were determined with spectra synthesis. Both FeI and Na abundances have been corrected for the non-LTE effect. In Table 4 we show the derived stellar parameters of our sample stars, and the Na abundances are shown in Table 6. (3 data files).

  2. Diagrama de estabilidad termodinámico del sistema de flotación cobre/agua/amilxantato

    Directory of Open Access Journals (Sweden)

    Beatriz Ramírez-Serrano

    2015-05-01

    Full Text Available El propósito del trabajo fue obtener el diagrama de estabilidad termodinámico que caracteriza al sistema de flotación cobre/agua/amilxantato, como parte del fundamento teórico necesario para el análisis del proceso de flotación de iones cobre con el reactivo colector de flotación amilxantato de potasio. A partir del sistema de reacciones químicas fundamentales y con ayuda del sofware Medusa se obtuvo el diagrama Eh-pH en el cual se definen las zonas de estabilidad de las diferentes especies químicas y se establece que en el rango de pH de 4 a 13 coexisten las especies xantogenadas de cobre(I y (II cuya relación disminuye con el incremento del pH.

  3. Master regulators, regulatory networks, and pathways of glioblastoma subtypes.

    Science.gov (United States)

    Bozdag, Serdar; Li, Aiguo; Baysan, Mehmet; Fine, Howard A

    2014-01-01

    Glioblastoma multiforme (GBM) is the most common malignant brain tumor. GBM samples are classified into subtypes based on their transcriptomic and epigenetic profiles. Despite numerous studies to better characterize GBM biology, a comprehensive study to identify GBM subtype- specific master regulators, gene regulatory networks, and pathways is missing. Here, we used FastMEDUSA to compute master regulators and gene regulatory networks for each GBM subtype. We also ran Gene Set Enrichment Analysis and Ingenuity Pathway Analysis on GBM expression dataset from The Cancer Genome Atlas Project to compute GBM- and GBM subtype-specific pathways. Our analysis was able to recover some of the known master regulators and pathways in GBM as well as some putative novel regulators and pathways, which will aide in our understanding of the unique biology of GBM subtypes.

  4. Visual observations of the vertical distribution of plankton throughout the water column above Broken Spur vent field, Mid-Atlantic Ridge

    Science.gov (United States)

    Vereshchaka, A. L.; Vinogradov, G. M.

    1999-09-01

    Visual observations were made in September 1997 during the 39 cruise of R/V "Akademik Mstislav Keldysh" with 2 deep-sea manned submersibles "Mir" aboard. During 4 dives the following plankton countings were made: 3 vertical throughout the water column during the day, 2 vertical in the upper 1000 m at night, and 1 oblique in the plume area during the day. Biomass profiles are represented for each dive for all abundant animal groups: copepods, euphausiids+decapods+mysids, chaetognaths, medusae, ctenophores, siphonophores, cyclothones, myctophides, radiolarians, and the total zooplankton. Plankton distribution shows 2 aggregations, one within the main pycnocline and the other near the plume; Gelatinous animals and radiolarians dominate in both aggregations by biomass and make a significant contribution to the plankton biomass throughout the water column. Oblique counting indicates the presence of aggregations of animals near the upper and lower borders of the plume and biomass depletion within the plume core.

  5. Vertical Array in Space for Horizontal Air-Showers

    CERN Document Server

    Fargion, D

    2009-01-01

    We consider the guaranteed physics of horizontal (hadron) air-showers, HAS, developing at high (tens km) altitudes. Their morphology and information traces are different from vertical ones. Hundreds of km long HAS are often split by geomagnetic fields in a long (fan-like) showering with a twin spiral tail. The horizontal fan-like airshowers are really tangent and horizontal only at North and South poles. At different latitude these showering plane are turned and inclined by geomagnetic fields. In particular at magnetic equator such tangent horizontal East-West airshowers are bent and developed into a vertical fan air-shower, easily detectable by a vertical array detector (hanging elements by gravity). Such "medusa" arrays maybe composed by inflated floating balloons chains. The light gas float and it acts as an calorimeter for the particles, while it partially sustains the detector weight. Vertically hanging chains as well as rubber doughnut balloons (whose interior may record Cherenkov lights) reveal bundles...

  6. [Research advances in the effects of environmental factors on the growth and development of Aurelia spp].

    Science.gov (United States)

    Wang, Jian-Yan; Yu, Zhi-Gang; Zhen, Yu; Mi, Tie-Zhu; Yao, Qing-Zhen; Wang, Guo-Shan

    2012-11-01

    Aurelia spp. is a cosmopolitan coastal species, and also, one dominant species of large jellyfish in the coastal waters of China. In recent years, Aurelia spp. bloom events occur frequently in the world, causing severe damage to marine ecosystems, coastal economy, and society development. Aurelia spp. has a complicated life history comprising a benthic asexually-reproducing polyp generation and a sexually-reproducing medusa generation, and various vegetative reproduction (budding, strobilation, and podocyst production) and sexual reproduction. Surrounding physical and biological factors affect each growth stage of Aurelia spp., especially the juvenile stage of planktonic-benthic life cycle, which has major effect on the population dynamics of Aurelia spp. This paper reviewed the research advances in the effects of environmental factors on Aurelia spp. at its different growth and development stages, and discussed some problems worthy of further study, aimed to provide useful reference for the research of the key factors controlling the jellyfish blooms in coastal waters of China.

  7. Nationalsozialismus und Holocaust in der spanischen Gegenwartsliteratur: Fiktionalisierte ‚images malgré tout‘ bei Ricardo Menéndez Salmón

    Directory of Open Access Journals (Sweden)

    Marco Thomas Bosshard

    2015-12-01

    Full Text Available Der vorliegende Artikel untersucht die literarischen Repräsentationen von nationalsozialistischen Kriegsverbrechen in den Romanen La ofensa und Medusa des spanischen Schriftstellers Ricardo Menéndez Salmón. Ausgehend von einer Kontextualisierung der Romane im Gesamtschaffen des Autors werden intertextuelle Bezüge nicht nur zu anderen literarischen Texten, sondern auch zur Theorie herausgearbeitet. Gegenüber dem im Zusammenhang mit Holocaust-Darstellungen oft postulierten ‚Bilderverbot‘ realisiert Menéndez Salmón in Anlehnung an Didi-Huberman fiktionalisierte images malgré tout im Medium der Sprache, deren Funktion über die Darstellung von Nazi-Verbrechen hinausgeht und eine metamediale Reflexion über den Zusammenhang von Bild, Sprache und Schrecken anstößt.

  8. Measurements of prompt radiation induced conductivity of alumina and sapphire

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, E. Frederick [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zarick, Thomas Andrew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sheridan, Timothy J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Preston, Eric F. [ITT Coporation, Colorado Springs, CO (United States)

    2011-04-01

    We performed measurements of the prompt radiation induced conductivity in thin samples of Alumina and Sapphire at the Little Mountain Medusa LINAC facility in Ogden, UT. Five mil thick samples were irradiated with pulses of 20 MeV electrons, yielding dose rates of 1E7 to 1E9 rad/s. We applied variable potentials up to 1 kV across the samples and measured the prompt conduction current. Analysis rendered prompt conductivity coefficients between 1E10 and 1E9 mho/m/(rad/s), depending on the dose rate and the pulse width for Alumina and 1E7 to 6E7 mho/m/(rad/s) for Sapphire.

  9. Prompt radiation-induced conductivity in polyurethane foam and glass microballoons

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, E. Frederick; Zarick, Thomas Andrew; Sheridan, Timothy J.; Preston, Eric F.

    2014-06-01

    We performed measurements and analyses of the prompt radiation-induced conductivity (RIC) in thin samples of polyurethane foam and glass microballoon foam at the Little Mountain Medusa LINAC facility in Ogden, UT. The RIC coefficient was non-linear with dose rate for polyurethane foam; however, typical values at 1E11 rad(si)/s dose rate was measured as 0.8E-11 mho/m/rad/s for 5 lb./cu ft. foam and 0.3E-11 mho/m/rad/s for 10 lb./cu ft. density polyurethane foam. For encapsulated glass microballoons (GMB) the RIC coefficient was approximately 1E-15 mho/m/rad/s and was not a strong function of dose rate.

  10. VizieR Online Data Catalog: He abundances in M30 and NGC 6397 (Mucciarelli+, 2014)

    Science.gov (United States)

    Mucciarelli, A.; Lovisi, L.; Lanzoni, B.; Ferraro, F. R.

    2017-06-01

    In this work we analyzed a set of high-resolution spectra acquired with the multi-object spectrograph FLAMES in the MEDUSA/GIRAFFE mode at the Very Large Telescope of the European Southern Observatory (ESO). The spectra are part of a data set secured within a project aimed at studying the general properties of blue straggler stars (Ferraro et al. 2006ApJ...647L..53F, 2009Natur.462.1028F, 2012Natur.492..393F; Lovisi et al. 2012, J/ApJ/754/91; 2013, J/ApJ/772/148). The employed GIRAFFE grating is HR5A (4340-4587 Å, with a spectral resolution of ~18000), suitable to sample the He I line at 4471.5 Å. Spectra have been reduced with the standard ESO FLAMES pipeline. Six exposures of 45 minutes each have been secured in each cluster. (1 data file).

  11. 青海省海北州菊科风毛菊属植物种类的开发利用%Development and Utilization of Plant Species in Saussurea of Asteraceae in Haibei State of Qinghai Province

    Institute of Scientific and Technical Information of China (English)

    霍建青

    2012-01-01

    There were tow kinds of Saussurea plants of Asteraceae with higher medicinal values in Haibei State of Qinghai Province.They were Saussurea medusa Maxim.and Saussurea hypsipeta Diels,which were both snow lotuses.The species morphological characteristics,biological characteristics,identification method and development foreground of Saussurea plants were introduced.%青海省海北州境内具有较高药用价值的菊科风毛菊属植物有2种,即水母雪兔子和黑毛雪兔子,这2种雪兔子统称为雪莲。介绍了风毛菊属植物的分种形态特征、生物学特性、鉴别方法及发展前景。

  12. Photosynthetic planulae and planktonic hydroids: contrasting strategies of propagule survival

    Directory of Open Access Journals (Sweden)

    Patrizia Pagliara

    2000-12-01

    Full Text Available Settlement delays can be important to prevent propagule waste when proper settling substrates are not immediately available. Under laboratory conditions, the planulae of Clytia viridicans underwent two alternative developmental patterns. Some settled on the bottom, forming a hydranth-gonotheca complex that produced up to four medusae and later either degenerated or gave rise to a hydroid colony. Other planulae settled right below the air-water interface, forming floating colonies that eventually fell to the bottom and settled. Halecium nanum released planulae with a rich population of symbiotic zooxanthellae that survived into a rearing jar for three months. After a long period of apparent quiescence (possibly fuelled by photosynthetic activities of zooxanthellae the planulae produced new colonies. Both photosynthetic planulae and settlement at the interface air-water allow a delay in the passage from a planktonic to a fully functional benthic life.

  13. A novel Aurelia aurita protein mesoglein contains DSL and ZP domains.

    Science.gov (United States)

    Matveev, I V; Shaposhnikova, T G; Podgornaya, O I

    2007-09-01

    Body of the scyphoid jellyfish Aurelia aurita consists of 2 epithelia -- epidermis and gastroderm. The layers are separated by a thick layer of extracellular matrix -- mesoglea. A. aurita has a lot of cells in the mesoglea unlike many other Cnidarians. The major protein of the mesoglea with apparent molecular mass of 47 kDa was detected by SDS-PAGE. A partial mRNA of the protein 1421 bp long was cloned and sequenced. The search for homologous nucleotide and protein sequences shows that the mRNA sequence is novel. Deduced amino acid sequence of 416 aa contains zona pellucida (ZP) domain and Delta/Serrate/Lag-2 (DSL) domain. The protein was named mesoglein. According to reverse transcription PCR analysis it is expressed in the mature medusa exclusively in the mesogleal cells. Mesoglein belongs to the lowest phyla among ZP domain-containing proteins. The protein is supposed to be a structural element of the mesoglea extracellular matrix.

  14. Regulation of polyp-to-jellyfish transition in Aurelia aurita.

    Science.gov (United States)

    Fuchs, Björn; Wang, Wei; Graspeuntner, Simon; Li, Yizhu; Insua, Santiago; Herbst, Eva-Maria; Dirksen, Philipp; Böhm, Anna-Marei; Hemmrich, Georg; Sommer, Felix; Domazet-Lošo, Tomislav; Klostermeier, Ulrich C; Anton-Erxleben, Friederike; Rosenstiel, Philip; Bosch, Thomas C G; Khalturin, Konstantin

    2014-02-03

    The life cycle of scyphozoan cnidarians alternates between sessile asexual polyps and pelagic medusa. Transition from one life form to another is triggered by environmental signals, but the molecular cascades involved in the drastic morphological and physiological changes remain unknown. We show in the moon jelly Aurelia aurita that the molecular machinery controlling transition of the sessile polyp into a free-swimming jellyfish consists of two parts. One is conserved and relies on retinoic acid signaling. The second, novel part is based on secreted proteins that are strongly upregulated prior to metamorphosis in response to the seasonal temperature changes. One of these proteins functions as a temperature-sensitive "timer" and encodes the precursor of the strobilation hormone of Aurelia. Our findings uncover the molecule framework controlling the polyp-to-jellyfish transition in a basal metazoan and provide insights into the evolution of complex life cycles in the animal kingdom. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Rhopalium development in Aurelia aurita ephyrae

    Science.gov (United States)

    Spangenberg, D. B.

    1991-01-01

    Rhopalia of developing ephyrae were examined using the SEM and TEM at 24 h intervals following strobilation induction. Kinocilia are shorter in the ephyra stage than in polyps. A few ephyra-type kinocilia are found in rhopalia as early as 24 h after induction, before a distinct rhopalium is seen. By 72 h, the shorter kinocilia predominate and are almost as numerous as in ephyrae (120 h). Many of the kinocilia are associated with mechanoreceptor cells (MR) found in the rhopalia. These MR cells are compared to those reported for medusae. Although newly released ephyrae lack a touch plate, the MR cells in their rhopalia along with the statocyst and neuromuscular system apparently enable these organisms to detect and respond to gravity.

  16. Effects of Weightlessness of Aurelia Ephyra Differentiation and Statolith Synthesis

    Science.gov (United States)

    Spangenberg, D. B.

    1985-01-01

    Aurelia polyps are especially suited for space flight experiments because they are very small (2 to 4 mm), form ephyrae with gravity sensing structures in 6 to 7 days, and can be reared easily and inexpensively in the laboratory. During iodine-induced metamorphosis ephyrae develop in sequential order from the oral to the aboral end of the polyps. Eight sites of gravity receptors (rhopalia) form per ephyra. These structures have sacs of statoliths at their distal end, which are composed of calcium sulfate dihydrate. Only one statolith forms per cell (statocyte) and the cells collect at the distal end of the rhopalia forming statocysts. Rhopalia with statocysts are necessary for the righting reflex of swimming medusae. Using the Aurelia Metamorphosis Test System (Spangenberg, 1984) for the past eight months, the effects of clinostat rotation in the horizontal and verticall planes on the development of ephyrae and the synthesis of their statoliths were investigated.

  17. Turritopsis fascicularis Fraser, 1943 (Cnidaria: Hydrozoa): redescription and discussion of its phylogenetic position within the genus.

    Science.gov (United States)

    Miglietta, Maria Pia

    2016-03-31

    Turritopsis fascicularis Fraser, 1943 was first described off Alligator Reef, Florida, USA, at a depth of 216 m. Presumably a deep-sea species, its validity has often been questioned due to the scarcity of available records. In this paper, T. fascicularis is re-described from some mature colonies from the upper slope of the Gulf of Mexico. Furthermore, new pictures of the colony, polyps, and medusa buds, are provided. A ~600bp sequence of the large ribosomal subunit of the mitochondrial RNA (lsu-rRNA, 16S), also known as the Hydrozoan barcoding molecule, is used for the first time to confirm the validity of T. fascicularis as a species, and analyze its phylogenetic position within the genus Turritopsis.

  18. Density regulation in Sarsia tubulosa (Hydrozoa)

    Science.gov (United States)

    Leonard, J. L.

    1980-03-01

    The majority of wild-caught Sarsia tubulosa M. Sars medusae are less dense than the surrounding water. The bell of S. tubulosa is the buoyant structure; the tentacles and manubrium sink if cut off from the bell. S. tubulosa individuals placed in dilute seawater sink initially but recover positive or neutral buoyancy and normal activity within a couple of hours. In all cases observed animals were able to achieve positive buoyancy in seawater of 20.25 ‰ S and some individuals were able to adjust to lower salinities. In most cases where positive buoyancy was not attained within two hours the animal did not achieve positive buoyancy within twelve hours and died within that period. While the mechanism of regulation is not known, ionic pumping, possibly involving the extrusion of sulphate ion, has been suggested to be responsible for the buoyancy of mesoglea in other jellyfishes.

  19. Feeding Currents Generated by Upside Down Jellyfish

    CERN Document Server

    Rodriguez, Terry; Gyoerkoe, Megan; Miller, Laura

    2010-01-01

    We present fluid dynamics videos of the pulsing dynamics and the resulting fluid flow generated by the upside down jellyfish, Cassiopea spp. Medusae of this genus are unusual in that they typically rest upside down on the ocean floor and pulse their bells to generate feeding currents, only swimming when significantly disturbed. The pulsing kinematics and fluid flow around these upside down jellyfish is investigated using a combination of videography, flow visualization, and numerical simulation. Significant mixing occurs around and directly above the oral arms and secondary mouths. Numerical simulations using the immersed boundary method with a porous layer representing the oral arms agree with the experimental results. The simulations also suggest that the presence of porous oral arms induce net horizontal flow towards the bell. Coherent vortex rings are not seen in the wake above the jellyfish, but starting and stopping vortices are observed before breaking up as they pass through the elaborate oral arms (i...

  20. La ficción entre trauma real e imaginario: “Shelter” de José Emilio Pacheco

    Directory of Open Access Journals (Sweden)

    Margherita Cannavacciuolo

    2013-07-01

    Full Text Available The study analyzes the short story “Shelter” (1964 by José Emilio Pacheco (México D.F., 1939, published in the volume La sangre de Medusa y otros cuentos marginales (1991. The apocalypse marks the narrative construction of a traumatic imaginary related with dichotomy between real and imaginary trauma. The protagonist’s fear of a Third World War produces a suspension of reality’s principle and the projection of his interiority, leading to a fracture into the story between the level of imagination and the real experience. The texts reflects the configuration of a discourse where trauma plays as the significant in the organization of subjectivity and fiction.

  1. Feasibility of an XUV FEL Oscillator Driven by a SCRF Linear Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A. H.; Freund, H. P.; Reinsch, M.

    2014-01-01

    The Advanced Superconducting Test Accelerator (ASTA) facility is currently under construction at Fermi National Accelerator Laboratory. Using a1-ms-long macropulse composed of up to 3000 micropulses, and with beam energies projected from 45 to 800 MeV, the possibility for an extreme ultraviolet (XUV) free-electron laser oscillator (FELO) with the higher energy is evaluated. We have used both GINGER with an oscillator module and the MEDUSA/OPC code to assess FELO saturation prospects at 120 nm, 40 nm, and 13.4 nm. The results support saturation at all of these wavelengths which are also shorter than the demonstrated shortest wavelength record of 176 nm from a storage-ring-based FELO. This indicates linac-driven FELOs can be extended into this XUV wavelength regime previously only reached with single-pass FEL configurations.

  2. 辽东湾北部近海大型水母数量分布和温度盐度特征%THE QUANTITY DISTRIBUTION OF GIANT JELLYFISH AND ITS RELATIONSHIP TO SEAWATER TEMPERATURE AND SALINITY IN INSHORE WATERS OF THE NORTHERN LIAODONG BAY REGION

    Institute of Scientific and Technical Information of China (English)

    王彬; 董婧; 王文波; 李玉龙; 李轶平; 刘修泽; 付杰

    2012-01-01

    The distribution of giant jellyfish and the ecological type were analyzed on the basis of the sampling data obtained during the surveys in inshore waters within 10m isobath of the northern Liaodong Bay, Bohai Sea from late May to late July from 2009 to 2011. There were four main species of giant jellyfish, Rhopilema esculentum, Nemopilema no- mural, Cyanea nozakii and Aurelia sp.1. The larval medusae of R. esculentum was mainly found within 5m isobath in coastal estuaries of the northern Liaodong Bay, and adult medusae was mainly found in both sides of the waters near 5m isobath. The adult had a slightly tendency to go to deep waters or low jellyfish catch density waters with the individual increasing. The relatively high temperature and low salinity area of coastal estuaries was an optimum environment for the growth of R. esculentum. There were a large amount of larval medusae of N. nomurai in inshore waters of northern Liaodong Bay in June, and the amount ofN. nomurai decreased a lot with the individual increasing in the area in July. Au- relia sp.1 mainly inhabitated in the southern Liaodong Bay, and was found a few in inshore waters of the northern Liaodong Bay in 2010 and 2011. C. nozakii inhabitated in high salinity area, and was few found in Liaodong Bay in recent years. Among giant jelly- fishes in Liaodong Bay, N. nomurai grew more quickly. The occurrence time of the larval medusa ofR. esculentum and N. nomurai in Liaodong Bay was later than in the Yellow Sea and East China Sea.%通过2009--2011年5月下旬-7月下旬辽东湾北部近海10m等深线内的大型水母调查数据.分析了辽东湾北部近海近三年中大型水母资源状况,并探讨了辽东湾大型水母的生态类型。结果显示:辽东湾北部近海大型水母种类主要有海蜇(Rhopilema esculentum)、沙蜇(Nemopilema nomurai)、白色霞水母(Cyaneanozakii)、海月水母(Aureliasp.1),海蜇和沙蜇是优势种。海蜇幼水

  3. THE MUTUAL PREDATORY RELATIONSHIP OF JELLYFISHES IN DIFFERENT LIFE STAGES BETWEEN A URELIA sp.1 AND RHOPILEMA ESCULENTA%生活史不同阶段的海月水母(Aurelia sp.1)与海蜇(Rhopilema esculenta)的相互捕食关系

    Institute of Scientific and Technical Information of China (English)

    李宗飞; 刘春胜; 庄志猛; 邹安革; 陈四清; 燕敬平; 刘长琳

    2012-01-01

    A laboratory experiment was conducted to investigate the predator-prey relationship at different life stages between Aurelia sp. 1 and Rhopilema esculenta. The results showed that Scyphistomae of Aurelia sp. 1, with l mm oral disk diameter, could prey on ephyrae and medusa ofR. esculenta whose oral disk was no more than 8mm in diameter; and in the ephyrae larval stage, Aurelia sp. 1 was able to prey on R. esculenta's; Aurelia sp. 1 medusa with 100mm bell diameter could still feed upon both ephyrae larval and early medusa (bell diameter ≤ 30mm) ofR. esculenta. However, the early medusa ofR. esculenta whose umbrella diameter was no less than 10mm could absolutely prey on Aurelia sp. 1 ephyrae larval. Au- relia sp.1 had stronger ability to prey on R. esculenta. These results revealed the relationship between the outbreak of Au- relia sp. 1 and the decrease ofR. esculenta resource. It was helpful to improve the effect of releasing R. esculenta.%采用交叉实验和水母体培养的方法,研究了不同生活史阶段的海月水母及海蜇之间的相互捕食关系。海月水母螅状体(口柄直径约为1mm)能够捕食海蜇碟状体及伞径≤8mm的海蜇幼体;海月水母的碟状体只能够捕食海蛰碟状体;伞径100mm的海月水母体能够捕食海蜇碟状体及伞径≤30mm的海蛰幼体。在海蜇对海月水母的捕食实验中发现,伞径≥10mm的海蜇幼体对海月水母的碟状体有捕食行为。通过对两种水母相互捕食关系的研究,笔者认为海月水母捕食海蜇的能力明显强于海蜇捕食海月水母的能力。这或许有助于解释近年来海月水母不断暴发而海蜇资源日渐减少的现象,有助于改进海蜇人工增殖放流措施,提高放流效果。

  4. Searching for IMBHs in Galactic globular clusters through radial velocities of individual stars

    Science.gov (United States)

    Lanzoni, Barbara

    2016-02-01

    I present an overview of our ongoing project aimed at building a new generation of velocity dispersion profiles ad rotation curves for a representative sample of Galactic globular clusters, from the the radial velocity of hundreds of individual stars distributed at different distances from the cluster center. The innermost portion of the profiles will be used to constrain the possible presence of intermediate-mass black holes. The adopted methodology consists of combining spectroscopic observations acquired with three different instruments at the ESO-VLT: the adaptive-optics assisted, integral field unit (IFU) spectrograph SINFONI for the innermost and highly crowded cluster cores, the multi-IFU spectrograph KMOS for the intermediate regions, and the multi-fiber instrument FLAMES/GIRAFFE-MEDUSA for the outskirts. The case of NGC 6388, representing the pilot project that motivated the entire program, is described in some details.

  5. Comae Berenicids and related activities

    Science.gov (United States)

    Koseki, Masahiro

    2011-12-01

    The Comae Berenicids have been considered as a winter shower but lower meteor activities continue the whole year round in this region. It might be called the meteors of Coma Sororum Medusae (CSM) instead of Comae Berenicids (COM). The CSM radiant passes the zenith twice in lower latitudes of the northern hemisphere and CSM activities vary with the altitude of the radiant. December Leonis Minorids (DLM) and September varepsilon-Perseids (SPE) are distinct from the CSM background meteors, but July Pegasids (JPE), delta-Aurigids (DAU) and nu-Aurigids (NAU) are buried in this complex. The conglomeration of DLM, COM and JCO (January Comae Berenicids) has caused confusion in meteor observations as to whether they are three distinct sources or should be considered as one. A simple model of meteor stream structure shows the clear profile of their activities. Although their radiant drifts are overlapping, they might have different parent objects.

  6. Venom and cnidome ontogeny of the cubomedusae Chironex fleckeri.

    Science.gov (United States)

    McClounan, S; Seymour, J

    2012-12-15

    This is the first study to explore venom and cnidome variation of individual cubomedusae, Chironex fleckeri, of different ages and from different regional locations in relation to feeding ecology. As medusae matured the proportion of mastigophores (those nematocysts containing the lethal venom component) in the cnidome increased, along with proportion of the vertebrate toxic fraction, in the venom profile. This switch in cnidome and venom occurred at the seven to ten tentacle stage. Whole venom was found to be toxic specifically to vertebrate cardiac cells, as opposed to vertebrate skeletal cells, and dose dependent, along with the vertebrate toxic fraction. The venom and cnidome ontogeny, along with venom toxicity, is correlated with C. fleckeri's known feeding ecology. Large and mature C. fleckeri feed predominantly on vertebrates, and have a greater proportion of mastigophores in their cnidome along with more vertebrate toxic fraction in their venom, compared to when they are young and small feeding on invertebrates.

  7. [Tourism, imported parasitic diseases, and their prevention].

    Science.gov (United States)

    Tumol'skaia, N I; Zavoĭkin, V D; Mazmanian, M V; Plakhotnaia, G A; Kurbatova, I V; Zelia, O P; Gutova, V P

    2012-01-01

    The paper gives the results of observations of 1558 patients before and after tourist travels to tropical countries and 368 individuals visiting the north areas of the Russian Federation. Different conditions (malaria, amebiasis, leishmaniasis, intestinal and tissue helminthiasis, insect bites, venomous fish pricks, medusa burn, tick bites, etc.) were found in 402 persons. Prophylactic immunization included vaccination against hepatitis A and B viruses, meningitis, typhus, yellow fever, tick-borne encephalitis in more than 2500 patients (not including influenza vaccination in the epidemic season). The performed observations reinforce the statement that imported pathology is urgent to Russia and suggest that it is necessary to develop this section of medicine and to set up a network of health care facilities with a necessary therapeutic and diagnostic base to render skilled care to tourists. It is essential to improve medical staff training in travel medicine.

  8. First record and five new species of Xylographellini (Coleoptera: Ciidae) from China, with online DNA barcode library of the family.

    Science.gov (United States)

    Lopes-Andrade, Cristiano; Grebennikov, Vasily V

    2015-08-25

    We report the first record of the beetle tribe Xylographellini (Ciidae) from the continental Palaearctic Region, represented by five new species discovered in Yunnan and Sichuan provinces, China: Scolytocis danae sp. nov., Syncosmetus euryale sp. nov., Sync. medusa sp. nov., Sync. perseus sp. nov. and Sync. stheno sp. nov. Illustrations and identification keys are provided for these new species, and in order to facilitate further research of Ciidae we present an open-access DNA barcode library (dx.doi.org/10.5883/DS-SYNCOSM) containing 114 records (of 44 species in 14 genera), 15 of which belong to the newly described species. A phylogenetic analysis based on the barcode fragment of the cytochrome oxidase I gene did not recover much tree structure within Ciidae, however both Xylographus Mellié and Syncosmetus Sharp were recovered as clades, with a single Scolytocis Blair being the sister to the latter.

  9. Analyzers Measure Greenhouse Gases, Airborne Pollutants

    Science.gov (United States)

    2012-01-01

    to fuel cellular functions. "We think this chemical process did not exist when life first formed on Earth," he says, "because it is based on oxygen being available, and there was little oxygen available on the early Earth." It is possible that there are anaerobic regions beneath the sea floor in which life forms like those early non-Krebs Cycle microbes may yet exist. To detect and potentially collect samples of life emerging from hydrothermal vents, Flynn and his colleagues created Medusa, a multi-sensor instrument designed for long-term observation of diked vents on the ocean floor. When the vents erupt, Medusa assesses indicators of life within the expelled water. If the results are positive, the observatory collects samples and detaches from the ocean floor, making the long journey to the surface for retrieval by scientists. One of the indicators Medusa measures is the ratio of carbon isotopes in the water, namely carbon-12 and carbon-13. Living organisms preferentially take up carbon-12, Flynn says, so examining the ratio of these isotopes can help to determine the source of carbon in an environment as either biological or non-biological. "On Mars, there is evidence of localized methane in the atmosphere, and that methane could come from biological sources or from geochemical ones," Flynn says. "Determining the background planetary carbon isotope ratios and then evaluating the specific carbon ratios in this methane would help to determine how it was formed." A long-duration observatory similar to Medusa could one day provide essential evidence for or against the presence of life on the Red Planet or beneath the ice-crusted oceans of Europa.

  10. Fish Has Expression Too

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>Ocean is always a theme for documentary films on nature.The Silent World made by French Jacques Eves Kosto in 1956 is the first documentary film of ocean that has a full view of ecological scenes on seabed.Entertainment Weekly comments that"There are many excellent ocean themed documentary films in the world,but if you want to know the difference between the Ocean and those films,then it’ll be technology."During the process of making Ocean,Jacques Perrin and Jacques Cluzaud have invented and improved lots of equipments, applying the latest electrographic technology to capture the unprecedented texture of marine organism-fragile softness of medusa,mattress-like belly of blue whale etc.

  11. Glaciambulata neumayeri gen. et sp. nov., a new Antarctic trachymedusa (Cnidaria: Hydrozoa, with a revision of the family Ptychogastriidae

    Directory of Open Access Journals (Sweden)

    Horia R. Galea

    2016-12-01

    Full Text Available A new genus and species of sympagic trachymedusa, Glaciambulata neumayeri gen. et sp. nov., are described based on material from Antarctica. Its generic features are compared to those of its relatives, Ptychogastria Allman, 1878 and Tesserogastria Beyer, 1959, and a review of the family Ptychogastriidae Mayer, 1910, based on literature data, is provided. From this, it results that the poorly-known Pectis antarctica Haeckel, 1879, formerly assigned to Ptychogastria by a number of authors, displays all characters of the contemporary rhopalonematid genus Voragonema Naumov, 1971. It is additionally demonstrated that V. laciniata Bouillon et al., 2001 is coterminous with P. antarctica, a finding that clarifies, 137 years later, the morphology and the taxonomic status of Haeckel’s medusa. In accordance with the Principle of Priority, Pectis is recognized as the valid name of the genus, and Voragonema is assigned to its synonymy. Similarly so, the specific name introduced by Haeckel has priority over laciniata.

  12. Does the association of young fishes with jellyfishes protect from predation?A report on a failure case due to damage to the jellyfish

    Directory of Open Access Journals (Sweden)

    Roberta Martini Bonaldo

    Full Text Available The fish-jellyfish association is regarded as a temporary symbiosis believed to protect the fishes from predators. Here we report on juvenile scads (Trachurus lathami associated with the jellyfish Chrysaora lactea, opportunistically preyed on by the grouper Mycteroperca acutirostris while the medusa was being damaged. The predation instances occurred when a couple of the filefish Stephanolepis hispidus approached the jellyfish to nibble on its umbrella. The feeding of the filefish caused a momentary disturbance of the defensive association, perceived and capitalised on by the watchful grouper, an opportunistic and versatile hunter. Before and after the disturbance, the protection offered to the young fish by the jellyfish showed to be effective, which strengthens the hypothesis of defensive function of this association.

  13. Gene Expression Data from the Moon Jelly, Aurelia, Provide Insights into the Evolution of the Combinatorial Code Controlling Animal Sense Organ Development.

    Directory of Open Access Journals (Sweden)

    Nagayasu Nakanishi

    Full Text Available In Bilateria, Pax6, Six, Eya and Dach families of transcription factors underlie the development and evolution of morphologically and phyletically distinct eyes, including the compound eyes in Drosophila and the camera-type eyes in vertebrates, indicating that bilaterian eyes evolved under the strong influence of ancestral developmental gene regulation. However the conservation in eye developmental genetics deeper in the Eumetazoa, and the origin of the conserved gene regulatory apparatus controlling eye development remain unclear due to limited comparative developmental data from Cnidaria. Here we show in the eye-bearing scyphozoan cnidarian Aurelia that the ectodermal photosensory domain of the developing medusa sensory structure known as the rhopalium expresses sine oculis (so/six1/2 and eyes absent/eya, but not optix/six3/6 or pax (A&B. In addition, the so and eya co-expression domain encompasses the region of active cell proliferation, neurogenesis, and mechanoreceptor development in rhopalia. Consistent with the role of so and eya in rhopalial development, developmental transcriptome data across Aurelia life cycle stages show upregulation of so and eya, but not optix or pax (A&B, during medusa formation. Moreover, pax6 and dach are absent in the Aurelia genome, and thus are not required for eye development in Aurelia. Our data are consistent with so and eya, but not optix, pax or dach, having conserved functions in sensory structure specification across Eumetazoa. The lability of developmental components including Pax genes relative to so-eya is consistent with a model of sense organ development and evolution that involved the lineage specific modification of a combinatorial code that specifies animal sense organs.

  14. Variaciones morfológicas en Blackfordia virginica (Hydroidomedusae: Blackfordiidae en lagunas costeras de Chiapas, México

    Directory of Open Access Journals (Sweden)

    Carlos Álvarez Silva

    2003-06-01

    Full Text Available Blackfordia virginica es una hidromedusa importante en el zooplancton de lagunas costeras de México. Con el objeto de contribuir a su estudio se analizaron las variaciones morfológicas de esta especie en el sistema de lagunas costeras de Chiapas, México. Se estudiaron 503 ejemplares, sus tallas variaron de 6.1 a 9.9 mm de diámetro umbrelar; el número de tentáculos marginales varió de 86 a 125. Se reconocieron los sexos, 67.7% hembras y 30.2% machos. Solamente 31 medusas (26 hembras y cinco machos presentaron variaciones morfológicas, éstas fueron de 10 tipos distintos y afectaron principalmente el número y forma de conductos radiales y las gónadas. El tamaño de las medusas y el número de tentáculos reflejaron una correlación de 0.74.Blackfordia virginica is an important hydromedusae in the zooplankton of coastal lagoons at Mexico. In order to contribute to their study, morphological variations of these species were analyzed in the system of coastal lagoons of Chiapas, Mexico. A total of 503 jellyfish were studied their sizes varied from 6.1 to 9.9 mm of umbrelar diameter. The number of marginal tentacles varied from 86 to 125. A 67.7% females and 30.2% males were recognized. Only 31 jellyfish (26 females and five males presented morphological variations of ten different types and affected the number and form of the handles, radial channels and gonads. The size of the jellyfish and the number of tentacles reflected a correlation of 0.74.

  15. Gene Expression Data from the Moon Jelly, Aurelia, Provide Insights into the Evolution of the Combinatorial Code Controlling Animal Sense Organ Development.

    Science.gov (United States)

    Nakanishi, Nagayasu; Camara, Anthony C; Yuan, David C; Gold, David A; Jacobs, David K

    2015-01-01

    In Bilateria, Pax6, Six, Eya and Dach families of transcription factors underlie the development and evolution of morphologically and phyletically distinct eyes, including the compound eyes in Drosophila and the camera-type eyes in vertebrates, indicating that bilaterian eyes evolved under the strong influence of ancestral developmental gene regulation. However the conservation in eye developmental genetics deeper in the Eumetazoa, and the origin of the conserved gene regulatory apparatus controlling eye development remain unclear due to limited comparative developmental data from Cnidaria. Here we show in the eye-bearing scyphozoan cnidarian Aurelia that the ectodermal photosensory domain of the developing medusa sensory structure known as the rhopalium expresses sine oculis (so)/six1/2 and eyes absent/eya, but not optix/six3/6 or pax (A&B). In addition, the so and eya co-expression domain encompasses the region of active cell proliferation, neurogenesis, and mechanoreceptor development in rhopalia. Consistent with the role of so and eya in rhopalial development, developmental transcriptome data across Aurelia life cycle stages show upregulation of so and eya, but not optix or pax (A&B), during medusa formation. Moreover, pax6 and dach are absent in the Aurelia genome, and thus are not required for eye development in Aurelia. Our data are consistent with so and eya, but not optix, pax or dach, having conserved functions in sensory structure specification across Eumetazoa. The lability of developmental components including Pax genes relative to so-eya is consistent with a model of sense organ development and evolution that involved the lineage specific modification of a combinatorial code that specifies animal sense organs.

  16. An experimental study of Aurelia aurita feeding behaviour: Inference of the potential predation impact on a temperate estuarine nursery area

    Science.gov (United States)

    Pereira, Rita; Teodósio, Maria Alexandra; Garrido, Susana

    2014-06-01

    Temperate estuaries are nursery areas for economically important fisheries resources. The common jellyfish Aurelia aurita is a resident species in many of these areas, where it can reach high abundances. This work aimed to determine the potential for predation of A. aurita on zooplanktonic organisms and early life stages of fishes, measuring feeding rates at concentrations that mimic those occurring for zooplankton, fish eggs and larvae in an estuarine nursery area. A set of experiments was aimed at determining the feeding selectivity of jellyfish when offered a mixture of fish eggs and larvae and wild plankton. Clearance rates varied markedly with prey availability and concentrations. When given mixtures of different prey types, jellyfish preferentially elected some taxa (copepods and fish eggs). Data obtained in the laboratory experiments were used to infer the potential impact of jellyfish predation upon zooplankton and ichthyoplankton in the Guadiana estuary (Southern Iberia). Repeated sampling of zooplankton, fish eggs and medusae was undertaken during the summer season of 2011. Abundance determinations were combined with experimentally estimated clearance rates of individual medusa to infer the potential jellyfish-induced mortality on prey in the area. In June and early August jellyfish-induced mortality rates were very high, and half-life times (t1/2) were consequently short for the zooplankton and ichthyoplankton. Although the potentially overestimation of our feeding rates typical of confined laboratory experiments, the results show high ingestion and clearance rates at high temperatures, typical from summer condition, and results also suggest that either by predation on early life stages of fish, or by competition for food resources, jellyfish may have a significant impact on estuarine communities and its nursery function.

  17. Arte, mito e historia en dos obras de Ricardo Menéndez Salmón

    Directory of Open Access Journals (Sweden)

    Giovanna Fiordaliso

    2015-07-01

    Full Text Available Abstract – The object of this study are two works written by Ricardo Menéndez Salmon (1971- , La luz es más antigua que el amor (2010 and Medusa (2012. These texts are very interesting because, as postmodern works, they result as a mixture of different genres (essay, novel, biography and because they are built with a combination of fiction and history, through the red line of the reflection on Art. Through the experience of several artists, imagined or real, Ricardo Menéndez Salmon proposes a reflection on History and Myth, on the role of literature and art, establishing a significant relationship between the present and the past, memory and oblivion, language and images. Resumen – Objeto de este estudio son dos obras del escritor Ricardo Menéndez Salmón (1971- , La luz es más antigua que el amor (2010 y Medusa (2012. Estos textos son muy interesantes porque se fundan en una mezcla de varios géneros (ensayo, novela, biografía y se caracterizan por una manera original de combinar ficción e historia, reflexionando sobre el papel del Arte. A través de la experiencia de varios artistas, unos imaginados, otros reales, Ricardo Menéndez Salmón nos propone una reflexión sobre la Historia, el Mito, el papel de la literatura y el arte, el establecimiento de una relación significativa entre el presente y el pasado, la memoria y el olvido, el lenguaje y las imágenes.

  18. Resources for methylome analysis suitable for gene knockout studies of potential epigenome modifiers

    Directory of Open Access Journals (Sweden)

    Wilson Gareth A

    2012-07-01

    Full Text Available Abstract Background Methylated DNA immunoprecipitation (MeDIP is a popular enrichment based method and can be combined with sequencing (termed MeDIP-seq to interrogate the methylation status of cytosines across entire genomes. However, quality control and analysis of MeDIP-seq data have remained to be a challenge. Results We report genome-wide DNA methylation profiles of wild type (wt and mutant mouse cells, comprising 3 biological replicates of Thymine DNA glycosylase (Tdg knockout (KO embryonic stem cells (ESCs, in vitro differentiated neural precursor cells (NPCs and embryonic fibroblasts (MEFs. The resulting 18 methylomes were analysed with MeDUSA (Methylated DNA Utility for Sequence Analysis, a novel MeDIP-seq computational analysis pipeline for the identification of differentially methylated regions (DMRs. The observed increase of hypermethylation in MEF promoter-associated CpG islands supports a previously proposed role for Tdg in the protection of regulatory regions from epigenetic silencing. Further analysis of genes and regions associated with the DMRs by gene ontology, pathway, and ChIP analyses revealed further insights into Tdg function, including an association of TDG with low-methylated distal regulatory regions. Conclusions We demonstrate that MeDUSA is able to detect both large-scale changes between cells from different stages of differentiation and also small but significant changes between the methylomes of cells that only differ in the KO of a single gene. These changes were validated utilising publicly available datasets and confirm TDG's function in the protection of regulatory regions from epigenetic silencing.

  19. Facing the Heat: Thermoregulation and Behaviour of Lowland Species of a Cold-Dwelling Butterfly Genus, Erebia.

    Science.gov (United States)

    Kleckova, Irena; Klecka, Jan

    2016-01-01

    Understanding the potential of animals to immediately respond to changing temperatures is imperative for predicting the effects of climate change on biodiversity. Ectothermic animals, such as insects, use behavioural thermoregulation to keep their body temperature within suitable limits. It may be particularly important at warm margins of species occurrence, where populations are sensitive to increasing air temperatures. In the field, we studied thermal requirements and behavioural thermoregulation in low-altitude populations of the Satyrinae butterflies Erebia aethiops, E. euryale and E. medusa. We compared the relationship of individual body temperature with air and microhabitat temperatures for the low-altitude Erebia species to our data on seven mountain species, including a high-altitude population of E. euryale, studied in the Alps. We found that the grassland butterfly E. medusa was well adapted to the warm lowland climate and it was active under the highest air temperatures and kept the highest body temperature of all species. Contrarily, the woodland species, E. aethiops and a low-altitude population of E. euryale, kept lower body temperatures and did not search for warm microclimates as much as other species. Furthermore, temperature-dependence of daily activities also differed between the three low-altitude and the mountain species. Lastly, the different responses to ambient temperature between the low- and high-altitude populations of E. euryale suggest possible local adaptations to different climates. We highlight the importance of habitat heterogeneity for long-term species survival, because it is expected to buffer climate change consequences by providing a variety of microclimates, which can be actively explored by adults. Alpine species can take advantage of warm microclimates, while low-altitude grassland species may retreat to colder microhabitats to escape heat, if needed. However, we conclude that lowland populations of woodland species may be

  20. Flow structure and transport characteristics of feeding and exchange currents generated by upside-down Cassiopea jellyfish.

    Science.gov (United States)

    Santhanakrishnan, Arvind; Dollinger, Makani; Hamlet, Christina L; Colin, Sean P; Miller, Laura A

    2012-07-15

    Quantifying the flows generated by the pulsations of jellyfish bells is crucial for understanding the mechanics and efficiency of their swimming and feeding. Recent experimental and theoretical work has focused on the dynamics of vortices in the wakes of swimming jellyfish with relatively simple oral arms and tentacles. The significance of bell pulsations for generating feeding currents through elaborate oral arms and the consequences for particle capture are not as well understood. To isolate the generation of feeding currents from swimming, the pulsing kinematics and fluid flow around the benthic jellyfish Cassiopea spp. were investigated using a combination of videography, digital particle image velocimetry and direct numerical simulation. During the rapid contraction phase of the bell, fluid is pulled into a starting vortex ring that translates through the oral arms with peak velocities that can be of the order of 10 cm s(-1). Strong shear flows are also generated across the top of the oral arms throughout the entire pulse cycle. A coherent train of vortex rings is not observed, unlike in the case of swimming oblate medusae such as Aurelia aurita. The phase-averaged flow generated by bell pulsations is similar to a vertical jet, with induced flow velocities averaged over the cycle of the order of 1-10 mm s(-1). This introduces a strong near-horizontal entrainment of the fluid along the substrate and towards the oral arms. Continual flow along the substrate towards the jellyfish is reproduced by numerical simulations that model the oral arms as a porous Brinkman layer of finite thickness. This two-dimensional numerical model does not, however, capture the far-field flow above the medusa, suggesting that either the three-dimensionality or the complex structure of the oral arms helps to direct flow towards the central axis and up and away from the animal.

  1. Facing the Heat: Thermoregulation and Behaviour of Lowland Species of a Cold-Dwelling Butterfly Genus, Erebia

    Science.gov (United States)

    Kleckova, Irena; Klecka, Jan

    2016-01-01

    Understanding the potential of animals to immediately respond to changing temperatures is imperative for predicting the effects of climate change on biodiversity. Ectothermic animals, such as insects, use behavioural thermoregulation to keep their body temperature within suitable limits. It may be particularly important at warm margins of species occurrence, where populations are sensitive to increasing air temperatures. In the field, we studied thermal requirements and behavioural thermoregulation in low-altitude populations of the Satyrinae butterflies Erebia aethiops, E. euryale and E. medusa. We compared the relationship of individual body temperature with air and microhabitat temperatures for the low-altitude Erebia species to our data on seven mountain species, including a high-altitude population of E. euryale, studied in the Alps. We found that the grassland butterfly E. medusa was well adapted to the warm lowland climate and it was active under the highest air temperatures and kept the highest body temperature of all species. Contrarily, the woodland species, E. aethiops and a low-altitude population of E. euryale, kept lower body temperatures and did not search for warm microclimates as much as other species. Furthermore, temperature-dependence of daily activities also differed between the three low-altitude and the mountain species. Lastly, the different responses to ambient temperature between the low- and high-altitude populations of E. euryale suggest possible local adaptations to different climates. We highlight the importance of habitat heterogeneity for long-term species survival, because it is expected to buffer climate change consequences by providing a variety of microclimates, which can be actively explored by adults. Alpine species can take advantage of warm microclimates, while low-altitude grassland species may retreat to colder microhabitats to escape heat, if needed. However, we conclude that lowland populations of woodland species may be

  2. Facing the Heat: Thermoregulation and Behaviour of Lowland Species of a Cold-Dwelling Butterfly Genus, Erebia.

    Directory of Open Access Journals (Sweden)

    Irena Kleckova

    Full Text Available Understanding the potential of animals to immediately respond to changing temperatures is imperative for predicting the effects of climate change on biodiversity. Ectothermic animals, such as insects, use behavioural thermoregulation to keep their body temperature within suitable limits. It may be particularly important at warm margins of species occurrence, where populations are sensitive to increasing air temperatures. In the field, we studied thermal requirements and behavioural thermoregulation in low-altitude populations of the Satyrinae butterflies Erebia aethiops, E. euryale and E. medusa. We compared the relationship of individual body temperature with air and microhabitat temperatures for the low-altitude Erebia species to our data on seven mountain species, including a high-altitude population of E. euryale, studied in the Alps. We found that the grassland butterfly E. medusa was well adapted to the warm lowland climate and it was active under the highest air temperatures and kept the highest body temperature of all species. Contrarily, the woodland species, E. aethiops and a low-altitude population of E. euryale, kept lower body temperatures and did not search for warm microclimates as much as other species. Furthermore, temperature-dependence of daily activities also differed between the three low-altitude and the mountain species. Lastly, the different responses to ambient temperature between the low- and high-altitude populations of E. euryale suggest possible local adaptations to different climates. We highlight the importance of habitat heterogeneity for long-term species survival, because it is expected to buffer climate change consequences by providing a variety of microclimates, which can be actively explored by adults. Alpine species can take advantage of warm microclimates, while low-altitude grassland species may retreat to colder microhabitats to escape heat, if needed. However, we conclude that lowland populations of

  3. Are Hox genes ancestrally involved in axial patterning? Evidence from the hydrozoan Clytia hemisphaerica (Cnidaria.

    Directory of Open Access Journals (Sweden)

    Roxane Chiori

    Full Text Available BACKGROUND: The early evolution and diversification of Hox-related genes in eumetazoans has been the subject of conflicting hypotheses concerning the evolutionary conservation of their role in axial patterning and the pre-bilaterian origin of the Hox and ParaHox clusters. The diversification of Hox/ParaHox genes clearly predates the origin of bilaterians. However, the existence of a "Hox code" predating the cnidarian-bilaterian ancestor and supporting the deep homology of axes is more controversial. This assumption was mainly based on the interpretation of Hox expression data from the sea anemone, but growing evidence from other cnidarian taxa puts into question this hypothesis. METHODOLOGY/PRINCIPAL FINDINGS: Hox, ParaHox and Hox-related genes have been investigated here by phylogenetic analysis and in situ hybridisation in Clytia hemisphaerica, an hydrozoan species with medusa and polyp stages alternating in the life cycle. Our phylogenetic analyses do not support an origin of ParaHox and Hox genes by duplication of an ancestral ProtoHox cluster, and reveal a diversification of the cnidarian HOX9-14 genes into three groups called A, B, C. Among the 7 examined genes, only those belonging to the HOX9-14 and the CDX groups exhibit a restricted expression along the oral-aboral axis during development and in the planula larva, while the others are expressed in very specialised areas at the medusa stage. CONCLUSIONS/SIGNIFICANCE: Cross species comparison reveals a strong variability of gene expression along the oral-aboral axis and during the life cycle among cnidarian lineages. The most parsimonious interpretation is that the Hox code, collinearity and conservative role along the antero-posterior axis are bilaterian innovations.

  4. Use of an Inverse Method for Time Series to Estimate the Dynamics of and Management Strategies for the Box Jellyfish Carybdea marsupialis.

    Directory of Open Access Journals (Sweden)

    Cesar Bordehore

    Full Text Available Frequently, population ecology of marine organisms uses a descriptive approach in which their sizes and densities are plotted over time. This approach has limited usefulness for design strategies in management or modelling different scenarios. Population projection matrix models are among the most widely used tools in ecology. Unfortunately, for the majority of pelagic marine organisms, it is difficult to mark individuals and follow them over time to determine their vital rates and built a population projection matrix model. Nevertheless, it is possible to get time-series data to calculate size structure and densities of each size, in order to determine the matrix parameters. This approach is known as a "demographic inverse problem" and it is based on quadratic programming methods, but it has rarely been used on aquatic organisms. We used unpublished field data of a population of cubomedusae Carybdea marsupialis to construct a population projection matrix model and compare two different management strategies to lower population to values before year 2008 when there was no significant interaction with bathers. Those strategies were by direct removal of medusae and by reducing prey. Our results showed that removal of jellyfish from all size classes was more effective than removing only juveniles or adults. When reducing prey, the highest efficiency to lower the C. marsupialis population occurred when prey depletion affected prey of all medusae sizes. Our model fit well with the field data and may serve to design an efficient management strategy or build hypothetical scenarios such as removal of individuals or reducing prey. TThis This sdfsdshis method is applicable to other marine or terrestrial species, for which density and population structure over time are available.

  5. Gelatinous zooplankton in the Belgian part of the North Sea and the adjacent Schelde estuary: Spatio-temporal distribution patterns and population dynamics

    Science.gov (United States)

    Vansteenbrugge, Lies; Van Regenmortel, Tina; De Troch, Marleen; Vincx, Magda; Hostens, Kris

    2015-03-01

    Many ocean ecosystems are thought to be heading towards a dominance of gelatinous organisms. However, gelatinous zooplankton has been largely understudied and the absence of quantitative long-term data for the studied area impedes drawing conclusions on potential increasing densities. This study gives a comprehensive overview of the spatio-temporal distribution patterns of gelatinous zooplankton in terms of diversity and density in the Belgian part of the North Sea and the adjacent Schelde estuary, based on monthly and seasonal samples between March 2011 and February 2012. Three Scyphozoa, three Ctenophora and 27 Hydrozoa taxa were identified, including three non-indigenous species: Mnemiopsis leidyi, Nemopsis bachei and Lovenella assimilis. In general, one gelatinous zooplankton assemblage was found across locations and seasons. Average gelatinous zooplankton densities reached up to 18 ind·m-3 near the coast, gradually declining towards the open sea. In the brackish Schelde estuary, average densities remained below 3 ind·m-3. Highest gelatinous zooplankton densities were recorded in summer and autumn. Overall, hydromedusae were the most important group both in terms of diversity and density. The ctenophore Pleurobrachia pileus and the hydromedusa Clytia sp. were present in every season and at every location. Gelatinous zooplankton densities never outnumbered the non-gelatinous zooplankton densities recorded from the WP3 samples. The spatial and temporal distribution patterns seemed to be mainly driven by temperature (season) and salinity (location). Other environmental parameters including (larger) non-gelatinous zooplankton densities (as an important food source) were not retained in the most parsimonious DistLM model.In terms of population dynamics, Beroe sp. seemed to follow the three reproductive cycles of its prey P. pileus and the presence of M. leidyi, which were abundant in a broad size spectrum in summer and autumn. In general, gelatinous zooplankton

  6. 我国海域常见有毒水母的分类检索%Taxonomy Key of the Venomous Jellyfishes in China Sea

    Institute of Scientific and Technical Information of China (English)

    刘萍; 张学雷; 宋洪军; 庞敏

    2013-01-01

    综合现有资料编制了我国海域常见的19种有毒水母种类的分类检索表.我国常见有毒水母分属于3纲8目14科17属,包括水螅水母类3种、管水母类2种、立方水母类2种、钵水母类12种,其中钵水母纲旗口水母目和根口水母目种类较多(各5种),其它目每目含1~2科且每科仅1属1种.对我国现有的水母分类体系中部分与国际通用体系不统一之处进行了厘正,如:火水母拉丁文种名应由Tamoya alata Uchida,1929厘正为Tamoya gargantua Haeckel,1880,建议将灯罩水母[Linuche draco (Haeckel,1880)]命名厘正为爪罩水母[Linuche unguiculata (Schwartz,1788)]等.%A taxonomy key for 19 species of common venomous jellyfishes in China sea was constructed based on the morphologic characteristics of different classes,orders,families,genera and species.There were 3 hydromedusa,2 siphonophore,2 cubomedusae and 12 scyphomedusae.More species belonged to the orders Semaeostomeae (5 species) and Rhizostomeae (5 species) of class Scyphozoa,and fewer (1 or 2 species) per the other orders.Some inconsistency of jellyfish taxonomy being used in China was detected and clarified,e.g.the abandoned name of Tamoya alata (Uchida,1829) should be replaced with Tamoya gargantua (Haeckel,1880),and the name of Linuchedraco (Haeckel,1880) was suggested to be replaced with the currently accepted name Linuche unguiculata (Schwartz,1788) following WoRMS (World Register of Marine Species).

  7. 伊犁河谷围封草地群落组成及植物多样性的变化%Changes of community composition and plant diversity of enclosing grassland in Yili Valley

    Institute of Scientific and Technical Information of China (English)

    李军保; 刘东林; 吐尔逊娜依·热依木江; 朱进忠

    2013-01-01

    以伊犁河谷昭苏马场春秋牧场不同围封年限草地为对象,对围封条件下退化草地自然恢复过程中草地植被特征及物种多样性的变化进行了初步分析.结果表明,随着围封年限的延长和立地条件的改善,草地植物群落由未围封的异株百里香(Thymus marschalianus)+草原苔草(Carex liparocarpos)逐步向适应当地气候条件的针茅(Stipa capillata)+草原苔草(Carex liparocarpos)方向演进.随围封年限的延长,草地植物的群落高度、生物量围封5年时达到最大,之后降低;而群落盖度和优良牧草比例继续增加,围封6年时达到最大;丰富度指数围封6年时达到最大,与其它样地之间差异显著(P<0.05);多样性指数和均匀度指数都是在围封1年时达到最大;优势度指数围封6年时达到最大;不同围封年限草地之间的相似性指数都在0.65以上;围封6年与围封5年草地的相似性指数最大,说明草地恢复到一定阶段后群落趋于稳定,未围封草地受放牧干扰,物种变化波动较大,与围封草地群落的相似性指数较小.

  8. Jellyfish support high energy intake of leatherback sea turtles (Dermochelys coriacea: video evidence from animal-borne cameras.

    Directory of Open Access Journals (Sweden)

    Susan G Heaslip

    Full Text Available The endangered leatherback turtle is a large, highly migratory marine predator that inexplicably relies upon a diet of low-energy gelatinous zooplankton. The location of these prey may be predictable at large oceanographic scales, given that leatherback turtles perform long distance migrations (1000s of km from nesting beaches to high latitude foraging grounds. However, little is known about the profitability of this migration and foraging strategy. We used GPS location data and video from animal-borne cameras to examine how prey characteristics (i.e., prey size, prey type, prey encounter rate correlate with the daytime foraging behavior of leatherbacks (n = 19 in shelf waters off Cape Breton Island, NS, Canada, during August and September. Video was recorded continuously, averaged 1:53 h per turtle (range 0:08-3:38 h, and documented a total of 601 prey captures. Lion's mane jellyfish (Cyanea capillata was the dominant prey (83-100%, but moon jellyfish (Aurelia aurita were also consumed. Turtles approached and attacked most jellyfish within the camera's field of view and appeared to consume prey completely. There was no significant relationship between encounter rate and dive duration (p = 0.74, linear mixed-effects models. Handling time increased with prey size regardless of prey species (p = 0.0001. Estimates of energy intake averaged 66,018 kJ • d(-1 but were as high as 167,797 kJ • d(-1 corresponding to turtles consuming an average of 330 kg wet mass • d(-1 (up to 840 kg • d(-1 or approximately 261 (up to 664 jellyfish • d(-1. Assuming our turtles averaged 455 kg body mass, they consumed an average of 73% of their body mass • d(-1 equating to an average energy intake of 3-7 times their daily metabolic requirements, depending on estimates used. This study provides evidence that feeding tactics used by leatherbacks in Atlantic Canadian waters are highly profitable and our results are consistent with estimates of mass gain prior to

  9. Martin Chalfie y la proteína verde fluorescente Martin Chalfie y la proteína verde fluorescente

    Directory of Open Access Journals (Sweden)

    Zacarías Pereira Vega

    2012-12-01

    Full Text Available The history of the green fluorescent protein (GFP starts with Osamu Shimomura at the beginning of the 1960s, with his discovery from the extracts of the Aequorea victoria jellyfish. However, it is not until the beginning of the 1990s, that the neurobiologist Martin Chalfie, applying genetic engineering tech- niques, achieved for the first time the heterology expression of the GFP in prokaryotes (E. coli and eukaryotes (Caernohabditis elegans, from a clone of the jellyfish’s gen that codifies the GFP prepared by Douglas Prasher. Besides fluorescing in green, the results from this work also demonstrated that it does not require any other cofactor or enzyme of the jellyfish for its expression or for the own forming of a fluorophore. At the same time, Chalfie proposed that the GFP could be used for the marking of cells on living ani- mals or the tag of proteins. Based upon these results, many scientists started working on research related to the GFP; actually this protein is used on different fields such as biotechnol- ogy, development biology, environmental chemistry and medicine. In the case of the latter, it has helped to elucidate the cellular mechanisms from which diseases are made of. Science owes Roger Tsien, amongst other contributions, the creation of differ- ent mutations of the GFP.La historia de la proteína verde fluorescente (GFP se inicia con Osamu Shimomura a principios de la década de 1960, con su descubrimiento de esta proteína a partir de extractos de la medusa Aequorea victoria. Sin embargo, es a principios de la década de 1990 que el neurobiólogo Martin Chalfie, aplicando técnicas de ingeniería genética, logra por primera vez la expresión heteróloga de la GFP en procariotas (Escherichia coli y eucariotas (Caernohabditis elegans, a partir de un clon del gen de la medusa que codifica a la GFP, preparado por Douglas Prasher. Además de fluorescer en verde, los resultados de este trabajo también demostraron que no se

  10. 海月水母(Aurelia sp.1)对中肋骨条藻(Skeletonema costatum)和东海原甲藻(Prorocentrum donghaiense)摄食的研究%THE GRAZING OF AURELIA sp.1 ON SKELETONEMA COSTATUM AND PROROCENTR UM DONGHAIENSE

    Institute of Scientific and Technical Information of China (English)

    郑珊; 孙晓霞; 孙松

    2012-01-01

    The effects of different microalgal species and cell densities on the feedings of polyps, ephyrae and medusae of.4urelia sp. 1 under controlled laboratory conditions were investigated. Two species of microalgae, Skeletonema costatum and Prorocentrum donghaiense, were used. Different microalgal species and cell densities had significant effects on the feedings of polyps, ephyrae and medusae. With the increasing of microalgal cell desities, the ingestion rates (IR) of polyps and ephyrae increased while the clearance rates (CR) decreased. The maximum IR of polyps on S. costatum and P. dong- haiense were 4623 and 4118 cells/(ind-h), respectively, while the maximum IR of ephyrae on S. costatum and P. dong- haiense were 174671 and 47218 cells/(ind-h), respectively. At similar microalgal cell densities, the IR of ephyrae on S. costatum were higher than those on P. donghaiense, and the IR of ephyrae were higher than those of polyps. The adaption of microalgae made IR of polyps increased about ten times. Medusae did not feed on S. costatum and P. donghaiense.%采用饵料浓度差减法,在实验条件下研究了不同细胞密度的中肋骨条藻和东海原甲藻对海月水母水螅体、碟状体和水母体摄食活动的影响。结果表明,不同种类和密度的微藻细胞密度对水螅体、碟状体和水母体的摄食有显著影响。在实验的藻细胞密度范围内,随藻细胞密度的增加,水螅体和碟状体对中肋骨条藻和东海原甲藻的摄食率一直升高。水螅体对中肋骨条藻和东海原甲藻的最大摄食率均发生在藻细胞密度最高处,分别为4623cells/(ind·h1和4118cells/(ind·h1。碟状体对中肋骨条藻和东海原甲藻的最大摄食率也是发生在藻细胞密度最高处,分别为174671cells/(ind_h)和47218cells/(ind.h)。清滤率随着藻细胞密度增加而降低。在相似细胞密度下,碟状体对中肋骨条藻的摄食率高于东海

  11. Irukandji jellyfish polyps exhibit tolerance to interacting climate change stressors.

    Science.gov (United States)

    Klein, Shannon G; Pitt, Kylie A; Rathjen, Kristen A; Seymour, Jamie E

    2014-01-01

    Increasing ocean temperatures and strengthening boundary currents have caused the poleward migration of many marine species. Cubozoan jellyfish known to cause Irukandji syndrome have historically been confined to tropical waters but may be expanding into subtropical regions. Here, we examine the interactive effects of warming and acidification on the population dynamics of polyps of an Irukandji jellyfish, Alatina nr mordens, and the formation of statoliths in newly metamorphosed medusae, to determine if this jellyfish could tolerate future conditions predicted for southeast Queensland (SEQ), Australia. Two experiments, examining the orthogonal factors of temperature and pH, were undertaken. Experiment 1 mimicked the current, ca. 2050 and ca. 2100 summer temperature and pH conditions predicted for SEQ using A1F1 scenarios (temperature: 25, 27, 29 °C; pH: 7.9, 7.8, 7.6) and Experiment 2 mimicked current and future winter conditions (18 and 22 °C, pH 7.9, 7.8, 7.6). All polyps in Experiment 1 survived and budded. Fewer polyps budded in the lower pH treatments; however, patterns varied slightly among temperature treatments. Statoliths at pH 7.6 were 24% narrower than those at pH 7.8 and 7.9. Most polyps survived the winter conditions mimicked by Experiment 2 but only polyps in the 22 °C, pH 7.9 treatment increased significantly. The current absence of A. nr mordens medusae in SEQ, despite the polyps' ability to tolerate the current temperature and pH conditions, suggests that ecological, rather than abiotic factors currently limit their distribution. Observations that budding was lower under low pH treatments suggest that rates of asexual reproduction will likely be much slower in the future. We consider that A. nr mordens polyps are likely to tolerate future conditions but are unlikely to thrive in the long term. However, if polyps can overcome potential ecological boundaries and acidification proceeds slowly A. nr mordens could expand polewards in the short

  12. Australian HFC, PFC and SF6 emissions: atmospheric verification

    Science.gov (United States)

    Fraser, P.; Dunse, B.; Krummel, P. B.; Steele, P.; Manning, A. J.

    2011-12-01

    The synthetic greenhouse gases (GHGs: hydrofluorocarbons - HFCs, perfluorocarbons - PFCs, and sulfur hexafluoride - SF6), emitted largely by the refrigeration, aluminium and electricity distribution industries respectively, are currently responsible for less than 2% of Australia's net long-lived GHG emissions (DCCEE, 2011). Nevertheless, they have attracted the attention of policymakers because (1) if their growth in concentrations and emissions continues unabated, particularly HFCs - currently growing at 10% per year - then they could be responsible globally (and in Australia) for more than 10% of the radiative forcing due to long-lived GHGs by 2050 (Velders et al., 2009); and (2) they provide the opportunity for a very cost-effective GHG mitigation strategy, because emissions can be reduced significantly through better engineering to minimize emissions, through a ban on dispersive uses (as solvents for example) and through the use of low GWP (Global Warming Potential) alternatives (for example hydrofluoroethers - HFEs). CSIRO, through its involvement in the AGAGE global program of monitoring non-carbon dioxide GHGs (Prinn et al., 2000), has been making high precision in situ measurements (12 per day) of HFCs, PFCs and SF6 at Cape Grim, Tasmania, since 2004, using a gas chromatograph-mass spectrometer detector (GC-MSD) fitted with a custom-built cryo-focussing unit (Medusa: Miller et al., 2008). The resultant data have been used to derive Australian emissions by inverse modelling (NAME, TAPM) and interspecies correlation (ISC). The overall agreement between so-called bottom-up estimates of Australian emissions, as reported to the UNFCCC (United Nations Framework Convention on Climate Change), and top-down estimates from atmospheric observations, using NAME, TAPM and ISC, is encouraging. Australian UNFCCC reported emissions (DCCEE, 2011) generally agree to within of 10% of emissions calculated from Cape Grim data, scaled on a population basis, with some notable

  13. MRI对脑静脉畸形的诊断价值%Diagnostic value of MRI in cerebral venous malformation

    Institute of Scientific and Technical Information of China (English)

    牛磊; 朱蒙蒙; 王明皓; 崔文; 刘圆圆; 朱斌

    2011-01-01

    目的:探讨MRI对脑静脉畸形(CVM)的诊断价值.方法:收集本院18例脑静脉畸形病例,均行磁共振T1WI、T2WI、FLAIR、SWI、DWI、MRA及T1 Wl增强扫描的资料.结果:CVM位于幕下5例,幕上13例,18例均呈典型的“海蛇头”征.MRI显示髓静脉呈长T1长T2信号,引流静脉呈短T1稍长T2信号或长T1长T2信号.FLAIR上髓静脉为稍高信号,引流静脉为低信号或稍高信号.SWI及DWI上髓静脉和引流静脉均为低信号.增强呈“海蛇头”样改变,即多条髓静脉呈辐射状汇入粗大的引流静脉.结论:MRI能明确诊断脑静脉畸形.T1WI增强扫描及SWI均较敏感.SWI对CVM的诊断价值明显优于常规MRI序列.%Objective:To investigate the diagnostic value of MRI in cerebral venous malformations (CVM). Methods: 18 patients of CVM were collected, and all of them underwent T1 WI, T2WI. FLAIR. SWI. DWI. MRA. And T,W1 enhancement scans. Results:CVMs were located in infra in five cases, and supra tentorium in thirteen eleven patients. Eighteen presented the typical " caput medusae" appearance. As for MRI plain scans.the medullary veins showed hypointensity in T1 WI and hyperintensity in T2WI, while, the drainage veins featured hyperintensity in T1 WI and hyperintensity in T2 WI. FLAIR sequences manifested less medullary veins with hyperintensity and drainage veins with hypointensity or hyperintensity. Both the medullary and the drainage veins appeared hypointensity in DWI and SWI. After enhancement, numerous radiating medullary veins gathered together into one or two larger drainage veins and flowed into superficial or deeper veins. Demonstrating the so-called "Caput Medusae" appearance. Conclusion: MRI is the first choice for suspected CVM patients thus providing more diagnostic information. T1 WI enhancement and SWI are sensitive to manifesting CVMs. SWI diagnosis of CVM is significantly superior to conventional MRI sequences.

  14. MR磁敏感加权成像在脑发育性静脉异常诊断中的应用%Value of susceptibility-weighted MR imaging for diagnosing developmental venous anomaly

    Institute of Scientific and Technical Information of China (English)

    梁长松; 陈忠; 叶文钦; 陈泽文; 李伟峰

    2013-01-01

      目的评价MR磁敏感加权成像(SWI)在脑发育性静脉异常(DVA)的应用价值。方法回顾性分析30例经磁共振诊断为脑静脉异常的患者MR表现,行常规MR扫描、增强扫描及SWI,10例加做MRA扫描。结果平扫5例DVA引流静脉呈条状稍长T1、稍长T2信号,3例呈长T1、短T2流空信号,22例显示不清,10例MRA显示引流静脉呈条状血管影,30例DVA增强扫描显示引流静脉及髓静脉强化,呈高信号“海蛇头”征,SWI也同时显示引流静脉及髓静脉,呈特征性“海蛇头”状低信号。结论常规MR序列显示DVA引流静脉不佳,增强扫描及SWI可同时显示引流静脉与髓静脉,SWI显示更佳,可作为诊断DVA的常规序列。%  Objective To evaluate susceptibility-weighted imaging for diagnosing developmental venous anomaly(DVA). Methods The conventional MRI(30),SWI(30)and MRV(10)of 30 patients with diagnosis of DVA on MRI were retrospectively analyzed.Results On unenhanced MRI draining veins were clearly demonstrated as hypointensity on T1WI and T2WI in 3 cases, hypointensity on T1WI and hyperintensity on T2WI in 5 cases. In 22 patients the draining veins were not seen.MRV showed the draining veins in all 10 patients. On contrast-enhanced MRI,medullary and draining veins were enhanced with the characteristic hyperintense caput medusa appearance. Hypointense caput medusa pattern was visible on SWI.Conclusions The draining veins of DVA were not well shown on conventional MRI but clearly demonstrated on contrast-enhanced MRI and SWI. More medullary veins are visible on SWI,which is valuable for diagnosing DVA.

  15. Polygonal Ridge Networks on Mars

    Science.gov (United States)

    Kerber, Laura; Dickson, James; Grosfils, Eric; Head, James W.

    2016-10-01

    Polygonal ridge networks, also known as boxwork or reticulate ridges, are found in numerous locations and geological contexts across Mars. While networks formed from mineralized fractures hint at hot, possibly life-sustaining circulating ground waters, networks formed by impact-driven clasting diking, magmatic dikes, gas escape, or lava flows do not have the same astrobiological implications. Distinguishing the morphologies and geological context of the ridge networks sheds light on their potential as astrobiological and mineral resource sites of interest. The most widespread type of ridge morphology is characteristic of the Nili Fossae and Nilosyrtis region and consists of thin, criss-crossing ridges with a variety of heights, widths, and intersection angles. They are found in ancient Noachian terrains at a variety of altitudes and geographic locations and may be a mixture of clastic dikes, brecciated dikes, and mineral veins. They occur in the same general areas as valley networks and ancient lake basins, but they are not more numerous where these features are concentrated, and can appear in places where they morphologies are absent. Similarly, some of the ridge networks are associated with hydrated mineral detections, but some occur in locations without detections. Smaller, light-toned ridges of variable widths have been found in Gale Crater and other rover sites and are interpreted to be smaller version of the Nili-like ridges, in this case formed by the mineralization of fractures. This type of ridge is likely to be found in many other places on Mars as more high-resolution data becomes available. Hellas Basin is host to a third type of ridge morphology consisting of large, thick, light-toned ridges forming regular polygons at several superimposed scales. While still enigmatic, these are most likely to be the result of sediment-filled fractures. The Eastern Medusae Fossae Formation contains large swaths of a fourth, previously undocumented, ridge network type

  16. New SI-traceable reference gas mixtures for fluorinated gases at atmospheric concentration

    Science.gov (United States)

    Guillevic, Myriam; Wyss, Simon A.; Pascale, Céline; Vollmer, Martin K.; Niederhauser, Bernhard; Reimann, Stefan

    2016-04-01

    In order to better support the monitoring of greenhouse gases in the atmosphere, we develop a method to produce reference gas mixtures for fluorinated gases (F-gases, i.e. gases containing fluorine atoms) in a SI-traceable way, meaning that the amount of substance fraction in mole per mole is traceable to SI-units. These research activities are conducted in the framework of the HIGHGAS and AtmoChem-ECV projects. First, single-component mixtures in synthetic air at ~85 nmol/mol (ppb) are generated for HFC-125 (pentafluoroethane, a widely used HFC) and HFC-1234yf (2,3,3,3-tetrafluoropropene, a car air conditioner fluid of growing importance). These mixtures are first dynamically produced by permeation: a permeator containing the pure substance loses mass linearly over time under a constant gas flow, in the permeation chamber of a magnetic suspension balance, which is regularly calibrated. This primary mixture is then pressurised into Silconert2000-coated stainless steel cylinders by cryo-filling. In a second step these mixtures are dynamically diluted using 2 subsequent dilution steps piloted by mass flow controllers (MFC) and pressure controllers. The assigned mixture concentration is calculated mostly based on the permeator mass loss, on the carrier gas purity and on the MFCs flows. An uncertainty budget is presented, resulting in an expanded uncertainty of 2% for the HFC-125 reference mixture and of 2.5% for the HFC-1234yf mixture (95% confidence interval). The final gas, with near-atmospheric concentration (17.11 pmol/mol for HFC-125, 2.14 pmol/mol for HFC-1234yf) is then measured with Medusa-GC/MS technology against standards calibrated on existing reference scales. The assigned values of the dynamic standards are in excellent agreement with measurements vs the existing reference scales, SIO-14 from the Scripps Institution of Oceanography for HFC-125 and Empa-2013 for HFC-1234yf. Moreover, the Medusa-GC/MS measurements show the excellent purity of the SI

  17. New SI-traceable reference gas mixtures for sulfur hexafluoride (SF6) at the pmol/mol level using static and dynamic preparation methods and comparison to existing scales

    Science.gov (United States)

    Wyss, Simon A.; Guillevic, Myriam; Vicar, Martin; Nieuwenkamp, Gerard; Vollmer, Martin K.; Pascale, Céline; Reimann, Stefan; Niederhauser, Bernhard; Emmenegger, Lukas

    2017-04-01

    We developed two SI-traceable methods, using both static and dynamic preparation steps, to produce reference gas mixtures for sulfur hexafluoride (SF6) in gas cylinders at pmol/mol level. This research activity is conducted under the framework of the European EMRP HIGHGAS project, in support of the high quality measurements of this important greenhouse gas in the earth's atmosphere. In the method used by the Czech Metrology Institute (CMI) a parent mixture of SF6 in synthetic air was produced in an aluminium cylinder at VSL as a first step. This mixture was produced gravimetrically according to ISO 6142 at an amount fraction of 1 μmol/mol. In the second step this primary standard was further diluted to near-ambient amount fraction, with the use of a three-step dilution system and directly pressurised into aluminium cylinders to a pressure of 10 bars. The second method used by the Federal Institute of Metrology (METAS) has already been applied to other fluorinated gases such as HFC-125 and HFC-1234yf. In this method a highly concentrated mixture is produced by spiking a purified synthetic air (matrix gas) with SF6 from a permeation device. The mass loss of SF6 in the permeation device is observed by a magnetic suspension balance. In a second step this mixture is diluted with matrix gas to the desired concentrations. All flows are controlled with mass flow controllers. The diluted gas was transferred into Silconert2000-coated stainless steel cylinders by cryo-filling. The final gas mixtures at near-ambient amount fraction were measured on a Medusa gas chromatography-mass spectrometry system (Medusa-GC/MS) against working standards calibrated on existing scales of the Scripps Institution of Oceanography (SIO) and compared to other scales [1]. The agreement of the assigned values by the CMI and METAS, with the measured values referenced on the SIO scale was excellent. This results show that with this methods we are able to produce accurate SI-traceable gas mixtures at

  18. The use of tropical bromeliads (Tillandsia spp. for monitoring atmospheric pollution in the town of Florence, Italy

    Directory of Open Access Journals (Sweden)

    Luigi Brighigna

    2002-06-01

    Full Text Available The results of an experiment with two species of epiphytic angiosperms (Tillandsia caput-medusae and T. bulbosa for monitoring polycyclic aromatic hydrocarbons (PAHs in the air of Florence, Italy, are presented. PAHs are compounds known to be dangerous because of their carcinogenic potential, and among cormophytes, tillands (monocotyledons equipped with peculiar, specialised, epidermal trichomes are considered promising for air pollution biomonitoring. PAHs data were obtained using GC/MS analysis of plant extracts. Analytical data indicated an increasing trend in time of PAHs bioaccumulation. This result was compared with instrumentally recorded parameters such as meteorological (rain and environmental ones (PM10, indicating that trichome-operated physical capture of aerial particles was prominent in PAHs bioaccumulation on tillands. SEM (scanning electron microscope observations confirmed the role of the trichomes. This work indicates that tillands are particularly useful, low-cost, biomonitoring organisms inside their area of distribution (all Latin American countries and southern USA where these plants are easily available, but also wherever the climate allows them to surviveSe presentan los resultados de un experimento con dos especies de angiospermas epífitas (Tillandsia caput-medusae y T. bulbosa para monitorear hidrocarbonos aromáticos policíclicos (PAHs en el aire de Florencia, Italia. Los PAHs son compuestos que se sabe son peligrosos por su potencial carcinogénico, y, entre las cormófitas, las tilandsias (monocotiledóneas equipadas con tricomas epidérmicos, especializados y peculiares son consideradas promisorias para el biomonitoreo de la contaminación del aire. Se obtuvieron datos de PAHs usando el análisis de GC/MS de extractos de plantas. Los datos analíticos indicaron una tendencia creciente de la bioacumulación de PAH’s en el tiempo. Este resultado se comparó con los parámetros registrados instrumentalmente como

  19. Climate change and ocean acidification impacts on lower trophic levels and the export of organic carbon to the deep ocean

    Directory of Open Access Journals (Sweden)

    A. Yool

    2013-09-01

    Full Text Available Most future projections forecast significant and ongoing climate change during the 21st century, but with the severity of impacts dependent on efforts to restrain or reorganise human activity to limit carbon dioxide (CO2 emissions. A major sink for atmospheric CO2, and a key source of biological resources, the World Ocean is widely anticipated to undergo profound physical and – via ocean acidification – chemical changes as direct and indirect results of these emissions. Given strong biophysical coupling, the marine biota is also expected to experience strong changes in response to this anthropogenic forcing. Here we examine the large-scale response of ocean biogeochemistry to climate and acidification impacts during the 21st century for Representative Concentration Pathways (RCPs 2.6 and 8.5 using an intermediate complexity global ecosystem model, MEDUSA-2.0. The primary impact of future change lies in stratification-led declines in the availability of key nutrients in surface waters, which in turn leads to a global decrease (1990s vs. 2090s in ocean productivity (−6.3%. This impact has knock-on consequences for the abundance of the low trophic level biogeochemical actors modelled by MEDUSA-2.0 (−5.8%, and these would be expected to similarly impact higher trophic level elements such as fisheries. Related impacts are found in the flux of organic material to seafloor communities (−40.7% at 1000 m, and in the volume of ocean suboxic zones (+12.5%. A sensitivity analysis removing an acidification feedback on calcification finds that change in this process significantly impacts benthic communities, suggesting that a~better understanding of the OA-sensitivity of calcifying organisms, and their role in ballasting sinking organic carbon, may significantly improve forecasting of these ecosystems. For all processes, there is geographical variability in change – for instance, productivity declines −21% in the Atlantic and increases +59% in

  20. Spectroscopic evaluation of the environmental impact on black crusted modern mortars in urban-industrial areas.

    Science.gov (United States)

    Prieto-Taboada, N; Maguregui, M; Martinez-Arkarazo, I; Olazabal, M A; Arana, G; Madariaga, J M

    2011-03-01

    A multianalytical characterisation of black crusted modern construction materials from buildings located in the Bilbao Metropolitan area (North Spain) was carried out. According to the mineral composition determined by Raman spectroscopy, calcite and hematite were the major compounds found while aragonite, limonite, rutile, quartz and some aluminosilicates such as obsidian or amazonite (KAlSi(3)O(8)) were also present in minor percentages. As deterioration products, gypsum and anhydrite were widely found not only in the surface but also in the inner part of strongly deteriorated samples. Coquimbite (Fe(2)(SO(4))(3)·9H(2)O) was identified as well in the most protected facade where high amounts of Fe, having probably an anthropogenic origin, were measured by micro X-ray fluorescence (μ-XRF). Zn was found to be in high amounts while Cu, Pb, Ti, Mn, Sr and K were identified as minor elements. Considering the non-expected concentrations found for some anthropogenic elements, a sequential extraction was carried out in order to determine their chemical form by means of ion chromatography and inductively coupled plasma mass spectrometry. The orientation of the facades, which had a different influence from rain washing and industrial and traffic impact, was shown to affect the accumulation of different compounds in the black crust. Finally, the MEDUSA software was used to simulate the reactions among the original compounds, deposited pollutants and the atmospheric acid gases in order to explain the presence of the decaying species found.

  1. Percutaneous paraumbilical embolization as an unconventional and successful treatment for bleeding jejunal varices

    Institute of Scientific and Technical Information of China (English)

    Lee-Guan Lim; Yin-Mei Lee; Lenny Tan; Stephen Chang; Seng-Gee Lim

    2009-01-01

    A 48-year-old Indian male with alcoholic liver cirrhosis was admitted after being found unresponsive. He was hypotensive and had hematochezia. Esophagogastroduodenoscopy (EGD) showed small esophageal varices and a clean-based duodenal ulcer. He continued to have hematochezia and anemia despite blood transfusions. Colonoscopy was normal. Repeat EGD did not reveal any source of recent bleed. Twelve days after admission, his hematochezia ceased. He refused further investigation and was discharged two days later. He presented one week after discharge with hematochezia. EGD showed non-bleeding Grade 1 esophageal varices and a clean-based duodenal ulcer. Colonoscopy was normal. Abdominal computed tomography (CT) showed liver cirrhosis with mild ascites, paraumbilical varices, and splenomegaly. He had multiple episodes of hematochezia, requiring repeated blood transfusions. Capsule endoscopy ident i f ied the bleeding s i te in the jejunum. Concurrently, CT angiography showed paraumbilical varices inseparable from a loop of small bowel, which had herniated through an umbilical hernia. The lumen of this loop of small bowel opacified in the delayed phase, which suggested variceal bleeding into the small bowel. Portal vein thrombosis was present. As he had severe coagulopathy and extensive paraumbilical varices, surgery was of high risk. He was not suitable for transjugular intrahepatic porto-systemic shunt as he had portal vein thrombosis. Percutaneous paraumbilical embolization via caput medusa was performed on day 9 of hospitalization. Following the embolization, the hematochezia stopped. However, he defaulted subsequent follow-up.

  2. Iconografie “antiche” nella collezione di calchi di intagli e cammei di Antonio Berini ai Civici Musei di Storia ed Arte di Trieste

    Directory of Open Access Journals (Sweden)

    Gabriella Tassinari

    2009-05-01

    Full Text Available Antonio Berini (Rome 1770-Milan 1861, famous gem-engraver, before 1804 decided to move from Rome to Milan, the capital of the Kingdom of Italy, where he lived, estemeed and praised; he was employed by the court and prestigious art patrons to engrave intaglios and cameos.A big collection of 114 plaster casts of intaglios and cameos made by Berini, without explanations, is now in the Civici Musei of Storia and Arte in Trieste, part of the bequest of Filippo Zamboni, cosmopolitan man of letters. These casts are a Berini’s very interesting “instrument of work”: in fact there are multiple casts and casts of works of other gem-engravers. Zamboni knew Berini very well; he writes that the artist was able to imitate ancient intaglios and cameos so perfectly that his engravings were mistakenly thought ancient. The subjects analysed in this article are common and often engraved by the artists of the second half of Eighteenth Century - first half of Nineteenth Century: the famous intaglio known as the Strozzi Medusa (reproduced by almost all engravers, Atena/Minerva/Roma’s head, Esculapio’s bust, Paride’s bust, gems depicting Famous Men, as Mecenate, Dante, Petrarca, Leonardo da Vinci, Michelangelo, Raffaello, Shakespeare, Alessandro Tassoni.

  3. Being the monster: women's narratives of body and self after treatment for breast cancer.

    Science.gov (United States)

    Rosenblatt, L

    2006-06-01

    Serious illness and its treatment frequently changes a woman's sense of herself and her body. Narrative medicine posits that individuals permitted to tell their stories regain control over the plotline of the illness, reclaim the central role as protagonist, and thus diminish the sense of helplessness, marginalisation, and isolation that are inevitable aspects of serious disease. The women presented here speak about losses that occur during treatment for advanced cancer. These losses include: loss of the former body; loss of one or both breasts; loss of hair; loss of fertility, and changes in weight, energy, and sexuality. This paper will not review the medical literature on the psychological aspects of change in appearance secondary to disease and/or treatment. As a way of broadening our understanding of what women attempt to communicate to their care providers about who they are and who they are becoming through the experience of illness, this paper will present brief excerpts from the interviews of four women talking about issues of identity and bodily change, using concepts of feminine identity developed by the French psychoanalytic theorist Hélène Cixous in her essay, The laugh of the Medusa.

  4. Iirimaale : [luuletused] / Percy Bysshe Shelley ; tlk. Minni Nurme, Ants, Oras

    Index Scriptorium Estoniae

    Shelley, Percy Bysshe

    2006-01-01

    Sisu: Iirimaale ; Armastuse roos ; Harrietile ; Muutlikkus ; Vangist vabanenud sõbrale ; Minevik ; Byronile ; Kaduvik ; Laul : "Maa magas, külm kui surm..." ; Hümn vaimsele ilule ; Laul : "Too aeg on läind, mu armsam, läind..." ; Ozymandias ; Sonett ; India serenaad ; Leonardo da Vinci Medusa Firenze kunstikogus ; Armu filosoofia ; Ood läänetuulele ; Mary Shelleyle ; Laul briti meestele ; Uus rahvushümn ; Inglismaa 1819. a. ; Ära madu ärata ; Head ööd! ; Pilv ; Apolloni hümn ; Paani hümn ; Lõoke ; Vabadus ; Suvi ja talv ; Maailmarändurid ; Küsimus ; Aeg, mis hajus ; Ööle ; -le : "Üht sõna on labastand suud..." ; -le : "Kui kirg kord mööduks, aga jääks..." ; Õhtu Ponte al Marel, Pisas ; Mälestus ; Muusika ; Aeg ; Põgenejad ; Ma olla kuningas ei tahaks ; "Homne päev, kus oled praegu..." ; "Laps rahus kord on emaihus..." ; Üksik lind ; "Kui lamp pihuks langend..." ; Epitaaf ; Kutse Janeþile ; Tähed vilkusid valgust ; Leinalaul ; Pühendus. Eluloolisi andmeid autori kohta lk. 389

  5. A novel modelling framework to prioritize estimation of non-point source pollution parameters for quantifying pollutant origin and discharge in urban catchments.

    Science.gov (United States)

    Fraga, I; Charters, F J; O'Sullivan, A D; Cochrane, T A

    2016-02-01

    Stormwater runoff in urban catchments contains heavy metals (zinc, copper, lead) and suspended solids (TSS) which can substantially degrade urban waterways. To identify these pollutant sources and quantify their loads the MEDUSA (Modelled Estimates of Discharges for Urban Stormwater Assessments) modelling framework was developed. The model quantifies pollutant build-up and wash-off from individual impervious roof, road and car park surfaces for individual rain events, incorporating differences in pollutant dynamics between surface types and rainfall characteristics. This requires delineating all impervious surfaces and their material types, the drainage network, rainfall characteristics and coefficients for the pollutant dynamics equations. An example application of the model to a small urban catchment demonstrates how the model can be used to identify the magnitude of pollutant loads, their spatial origin and the response of the catchment to changes in specific rainfall characteristics. A sensitivity analysis then identifies the key parameters influencing each pollutant load within the stormwater given the catchment characteristics, which allows development of a targeted calibration process that will enhance the certainty of the model outputs, while minimizing the data collection required for effective calibration. A detailed explanation of the modelling framework and pre-calibration sensitivity analysis is presented.

  6. Are diversification rates and chromosome evolution in the temperate grasses (Pooideae) associated with major environmental changes in the Oligocene-Miocene?

    Science.gov (United States)

    Pimentel, Manuel; Escudero, Marcial; Sahuquillo, Elvira; Minaya, Miguel Ángel; Catalán, Pilar

    2017-01-01

    The Pooideae are a highly diverse C3 grass subfamily that includes some of the most economically important crops, nested within the highly speciose core-pooid clade. Here, we build and explore the phylogeny of the Pooideae within a temporal framework, assessing its patterns of diversification and its chromosomal evolutionary changes in the light of past environmental transformations. We sequenced five plastid DNA loci, two coding (ndhF, matk) and three non-coding (trnH-psbA, trnT-L and trnL-F), in 163 Poaceae taxa, including representatives for all subfamilies of the grasses and all but four ingroup Pooideae tribes. Parsimony and Bayesian phylogenetic analyses were conducted and divergence times were inferred in BEAST using a relaxed molecular clock. Diversification rates were assessed using the MEDUSA approach, and chromosome evolution was analyzed using the chromEvol software. Diversification of the Pooideae started in the Late-Eocene and was especially intense during the Oligocene-Miocene. The background diversification rate increased significantly at the time of the origin of the Poodae + Triticodae clade. This shift in diversification occurred in a context of falling temperatures that potentially increased ecological opportunities for grasses adapted to open areas around the world. The base haploid chromosome number n = 7 has remained stable throughout the phylogenetic history of the core pooids and we found no link between chromosome transitions and major diversification events in the Pooideae.

  7. Nested radiations and the pulse of angiosperm diversification: increased diversification rates often follow whole genome duplications.

    Science.gov (United States)

    Tank, David C; Eastman, Jonathan M; Pennell, Matthew W; Soltis, Pamela S; Soltis, Douglas E; Hinchliff, Cody E; Brown, Joseph W; Sessa, Emily B; Harmon, Luke J

    2015-07-01

    Our growing understanding of the plant tree of life provides a novel opportunity to uncover the major drivers of angiosperm diversity. Using a time-calibrated phylogeny, we characterized hot and cold spots of lineage diversification across the angiosperm tree of life by modeling evolutionary diversification using stepwise AIC (MEDUSA). We also tested the whole-genome duplication (WGD) radiation lag-time model, which postulates that increases in diversification tend to lag behind established WGD events. Diversification rates have been incredibly heterogeneous throughout the evolutionary history of angiosperms and reveal a pattern of 'nested radiations' - increases in net diversification nested within other radiations. This pattern in turn generates a negative relationship between clade age and diversity across both families and orders. We suggest that stochastically changing diversification rates across the phylogeny explain these patterns. Finally, we demonstrate significant statistical support for the WGD radiation lag-time model. Across angiosperms, nested shifts in diversification led to an overall increasing rate of net diversification and declining relative extinction rates through time. These diversification shifts are only rarely perfectly associated with WGD events, but commonly follow them after a lag period. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  8. Comparative internal anatomy of Staurozoa (Cnidaria), with functional and evolutionary inferences

    Science.gov (United States)

    Collins, Allen G.; Hirano, Yayoi M.; Mills, Claudia E.

    2016-01-01

    Comparative efforts to understand the body plan evolution of stalked jellyfishes are scarce. Most characters, and particularly internal anatomy, have neither been explored for the class Staurozoa, nor broadly applied in its taxonomy and classification. Recently, a molecular phylogenetic hypothesis was derived for Staurozoa, allowing for the first broad histological comparative study of staurozoan taxa. This study uses comparative histology to describe the body plans of nine staurozoan species, inferring functional and evolutionary aspects of internal morphology based on the current phylogeny of Staurozoa. We document rarely-studied structures, such as ostia between radial pockets, intertentacular lobules, gametoducts, pad-like adhesive structures, and white spots of nematocysts (the last four newly proposed putative synapomorphies for Staurozoa). Two different regions of nematogenesis are documented. This work falsifies the view that the peduncle region of stauromedusae only retains polypoid characters; metamorphosis from stauropolyp to stauromedusa occurs both at the apical region (calyx) and basal region (peduncle). Intertentacular lobules, observed previously in only a small number of species, are shown to be widespread. Similarly, gametoducts were documented in all analyzed genera, both in males and females, thereby elucidating gamete release. Finally, ostia connecting adjacent gastric radial pockets appear to be universal for Staurozoa. Detailed histological studies of medusozoan polyps and medusae are necessary to further understand the relationships between staurozoan features and those of other medusozoan cnidarians.

  9. Mesozooplankton biomass and abundance in Cyprus coastal waters and comparison with the Aegean Sea (eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    C. C.S. HANNIDES

    2015-07-01

    Full Text Available Here we conduct the first comprehensive assessment of mesozooplankton abundance, biomass, and taxa composition in Cyprus coastal waters (Levantine Sea.  Mesozooplankton abundance and biomass sampled at several locations around the island ranged from 153 – 498 individuals m-3 and 0.7 – 5.2 mg dry weight m-3, respectively, with significantly larger biomass observed in winter-early spring (March than in summer (September.  The community was dominated by calanoid and cyclopoid copepods throughout the year (80% of total numbers, with higher abundances of predatory taxa (chaetognaths and medusae in winter and cladocerans in summer.  Overall, we find that coastal mesozooplankton communities around Cyprus appear to be more similar to communities in offshore waters or those around the island of Rhodes than to communities along the mainland Levantine coast.  We further highlight regional differences in the eastern Mediterranean by comparing our data with mesozooplankton in the western Aegean (Saronikos Gulf and northeastern Aegean Sea (NEA.  Distinct spatial differences were observed, for example anthropogenic influences in the Saronikos Gulf and the outflow of Modified Black Sea Water in the NEA drove generally greater biomass and abundance in these regions.  Overall, our comparison supports the concept of a latitudinal gradient in oligotrophy in the eastern Mediterranean, with ultra-oligotrophic conditions found in the Levantine Sea.

  10. Measurements of Prompt Radiation-Induced Conductivity of Pyralux®

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, E. Frederick [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Radiation Effects Experimentation Dept.; Zarick, Thomas Andrew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Radiation Effects Experimentation Dept.; McLain, Michael Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Radiation Effects Experimentation Dept.; Sheridan, Timothy J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Radiation Effects Experimentation Dept.; Preston, Eric F. [ITT Exelis, Colorado Springs, CO (United States); Stringer, Thomas Arthur [ITT Exelis, Colorado Springs, CO (United States)

    2014-01-01

    In this report, measurements of the prompt radiation-induced conductivity (RIC) in 3 mil samples of Pyralux® are presented as a function of dose rate, pulse width, and applied bias. The experiments were conducted with the Medusa linear accelerator (LINAC) located at the Little Mountain Test Facility (LMTF) near Ogden, UT. The nominal electron energy for the LINAC is 20 MeV. Prompt conduction current data were obtained for dose rates ranging from ~2 x 109 rad(Si)/s to ~1.1 x 1011 rad(Si)/s and for nominal pulse widths of 50 ns and 500 ns. At a given dose rate, the applied bias across the samples was stepped between -1500 V and 1500 V. Calculated values of the prompt RIC varied between 1.39x10-8 Ω-1 · m-1 and 2.67x10-7 Ω-1 · m-1 and the prompt RIC coefficient varied between 1.25x10-18 Ω-1 · m-1/rad/s and 1.93x10-17 Ω-1 · m-1/rad/s.

  11. Invertebrados Fósiles del Paleozoico de Sonora, México

    Directory of Open Access Journals (Sweden)

    Francisco Javier Cuen Romero

    2016-12-01

    Full Text Available A través de los fósiles es posible conocer la vida en el pasado geológico. La vida se originó en el mar hace 3700 Ma, siendo formas muy sencillas atribuibles a algas e invertebrados como las medusas; las primeras formas complejas se originaron a inicios del Paleozoico hace 541 Ma. El Paleozoico se divide en seis periodos: Cámbrico, Ordovícico, Silúrico, Devónico, Carbonífero y Pérmico; los cuales se caracterizan por una gran biodiversidad y abundancia de invertebrados. En Sonora se conocen diversas localidades con fósiles marinos del Paleozoico, destacando la presencia de poríferos, celenterados, braquiópodos, briozoarios, moluscos, artrópodos y equinodermos. El Paleozoico termina hace 252 Ma con la mayor extinción conocida en la historia de la biosfera, culminando con el 95% de las especies marinas.

  12. An annotated list of Urediniomycetes (rust fungi from South Africa 1: Melampsoraceae and Pucciniaceae, excluding Puccinia and Uromyces

    Directory of Open Access Journals (Sweden)

    M. van Reenen

    1995-12-01

    Full Text Available Up-to-date information is given on the identity, occurrence, nomenclature, host ranges, geographical distribution and literature references of the Urediniomycetes in South Africa. Species of the family Melampsoraceae and all species of the family Pucciniaceae other than those in the genera Puccinia Pers. and  Uromyces (Link Unger are listed. New species records since 1945 include the following:  Melampsora allii-populirui Kleb..  Melampsora coleosporioides Dietel.  Melampsora laricipopulina Kleb.. Melampsora medusae Thiim., Frommea obtusa-duchesneae (Arthur Arthur. Hemileia gardeniae-thunbergiae Maubl. & Roger.  Phakopsora gossypii (Arthur Hirats. F. Uromycladium tepperianum (Sacc. McAlpine and  Tranzschelia discolor (Fuckel Tranzschel & M.A. Litv. Although many species of rusts have already been recorded, these are thought to represent only a small percentage of the rust population in southern Africa. Furthermore, only a small portion of rust specimens at present housed at PREM have so far been studied. Continued research on this economically important group of fungi is therefore essential.

  13. New Mediterranean Marine biodiversity records (June 2013

    Directory of Open Access Journals (Sweden)

    I. SIOKOU

    2013-04-01

    Full Text Available This paper concerns records of species that have extended their distribution in the Mediterranean Sea. The finding of the rare brackish angiosperm Althenia filiformis in the island of Cyprus is interesting since its insertion in the Red Data Book of the Flora of Cyprus is suggested. The following species enriched the flora or fauna lists of the relevant countries: the red alga Sebdenia dichotoma (Greece, the hydrachnid mite Pontarachna adriatica (Slovenia, and the thalassinid Gebiacantha talismani (Turkey. Several alien species were recorded in new Mediterranean localities. The record of the burrowing goby Trypauchen vagina in the North Levantine Sea (Turkish coast, suggests the start of spreading of this Lessepsian immigrant in the Mediterranean Sea. The findings of the following species indicate the extension of their occurrence in the Mediterranean Sea: the foraminifer Amphistegina lobifera (island of Zakynthos, Greece, the medusa Cassiopea andromeda (Syria, the copepod Centropages furcatus (Aegean Sea, the decapod shrimp Melicertus hathor (island of Kastellorizo, Greece, the crab Menoethius monoceros (Gulf of Tunis, the barnacles Balanus trigonus, Megabalanus tintinnabulum, Megabalanus coccopoma and the bivalves Chama asperella, Cucurbitula cymbium (Saronikos Gulf, Greece.

  14. Artificial substrates preference for proliferation and immigration in Aurelia aurita (s. l.) polyps

    Science.gov (United States)

    Feng, Song; Lin, Jianing; Sun, Song; Zhang, Fang

    2017-01-01

    The increasing amounts of artificial marine substrates, in many parts of the world have been proposed as a potential driver of Aurelia spp. blooms, on account of providing extra habitats for the settlement and the proliferation of the benthic stage (polyps). Previous experiments have mainly focused on the substrate choices of Aurelia spp. planulae. However, substrate preferences for the proliferation and immigration of polyps have not been reported. We monitored the propagation and immigration of Aurelia aurita (s. l.) polyps on two natural and nine artificial substrates at constant temperature (20±0.5°C) and salinity (30±0.5) in beakers and a glass aquarium in the laboratory, respectively. The results showed that, among artificial substrates, the highest number for polyp proliferation and immigration was found on nets, rigid polyvinyl chloride plates (RPVC), and wood. The lowest density of polyps was present on iron plates. Among natural substrates, the asexual reproduction rate of polyps on Patinopecten yessoensis (Jay, 1857) shells was significantly higher than Azumapecten farreri (Jones & Preston, 1904). On the account of the distinction in the roughness, chemical properties and biofilms of these material surfaces, bare artificial or natural substrates discriminatively affect the proliferation and the immigration of Aurelia spp. polyps at laboratory. These observations suggest that, even in the natural environment, different materials and texture may influence the composition and the abundance of the fouling communities and the assemblages of polyps and, indirectly, have effects on the amounts of released medusae.

  15. To See or to Hear? Odysseus and the Sirens. Two Doors of our Perceptions and Various Implications

    Directory of Open Access Journals (Sweden)

    Igor Škamperle

    2015-04-01

    Full Text Available This paper deals with two fundamental forms of human sensory perception: the gaze and hearing. Each has been the subject of reflection, as each offers the possibility of various implications. Visual perception and the gaze create a sense of the world, though both myth and religion have been critical of visual imitating of reality and have denied the gaze a perceptual role. Did Odysseus, on his sea journey, see the alluring and dangerous Sirens, or did he in fact only hear them? This paper seeks to demonstrate some fundamental dilemmas offered by Homer's myth of the Sirens and its many modified versions. A critical assessment of the gaze and its magical powers is also offered in the myth of Perseus and the Gorgon Medusa, whose gaze enchants the viewer, as if he were petrified. It was precisely this that Odysseus feared when he descended into the underworld. But if access to the truth of consciousness and the world of lies is easier and more suitably put into practice through words and hearing, why are the Sirens dangerous and why must they lose in their competition with the Muses? What do they enchant with the gaze?

  16. New Mediterranean Marine biodiversity records (June 2013

    Directory of Open Access Journals (Sweden)

    I. SIOKOU

    2013-04-01

    Full Text Available This paper concerns records of species that have extended their distribution in the Mediterranean Sea. The finding of the rare brackish angiosperm Althenia filiformis in the island of Cyprus is interesting since its insertion in the Red Data Book of the Flora of Cyprus is suggested. The following species enriched the flora or fauna lists of the relevant countries: the red alga Sebdenia dichotoma (Greece, the hydrachnid mite Pontarachna adriatica (Slovenia, and the thalassinid Gebiacantha talismani (Turkey. Several alien species were recorded in new Mediterranean localities. The record of the burrowing goby Trypauchen vagina in the North Levantine Sea (Turkish coast, suggests the start of spreading of this Lessepsian immigrant in the Mediterranean Sea. The findings of the following species indicate the extension of their occurrence in the Mediterranean Sea: the foraminifer Amphistegina lobifera (island of Zakynthos, Greece, the medusa Cassiopea andromeda (Syria, the copepod Centropages furcatus (Aegean Sea, the decapod shrimp Melicertus hathor (island of Kastellorizo, Greece, the crab Menoethius monoceros (Gulf of Tunis, the barnacles Balanus trigonus, Megabalanus tintinnabulum, Megabalanus coccopoma and the bivalves Chama asperella, Cucurbitula cymbium (Saronikos Gulf, Greece.

  17. Measurements of Prompt Radiation-Induced Conductivity of Pyralux®

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, E. Frederick [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Radiation Effects Experimentation Dept.; Zarick, Thomas Andrew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Radiation Effects Experimentation Dept.; McLain, Michael Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Radiation Effects Experimentation Dept.; Sheridan, Timothy J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Radiation Effects Experimentation Dept.; Preston, Eric F. [ITT Exelis, Colorado Springs, CO (United States); Stringer, Thomas Arthur [ITT Exelis, Colorado Springs, CO (United States)

    2014-01-01

    In this report, measurements of the prompt radiation-induced conductivity (RIC) in 3 mil samples of Pyralux® are presented as a function of dose rate, pulse width, and applied bias. The experiments were conducted with the Medusa linear accelerator (LINAC) located at the Little Mountain Test Facility (LMTF) near Ogden, UT. The nominal electron energy for the LINAC is 20 MeV. Prompt conduction current data were obtained for dose rates ranging from ~2 x 109 rad(Si)/s to ~1.1 x 1011 rad(Si)/s and for nominal pulse widths of 50 ns and 500 ns. At a given dose rate, the applied bias across the samples was stepped between -1500 V and 1500 V. Calculated values of the prompt RIC varied between 1.39x10-8 Ω-1 · m-1 and 2.67x10-7 Ω-1 · m-1 and the prompt RIC coefficient varied between 1.25x10-18 Ω-1 · m-1/(rad/s) and 1.93x10-17 Ω-1 · m-1/(rad/s).

  18. Deletion of the Ustilago maydis ortholog of the Aspergillus sporulation regulator medA affects mating and virulence through pheromone response.

    Science.gov (United States)

    Chacko, Nadia; Gold, Scott

    2012-06-01

    Mating of compatible haploid cells of Ustilago maydis is essential for infection and disease development in the host. For mating and subsequent filamentous growth and pathogenicity, the transcription factor, prf1 is necessary. Prf1 is in turn regulated by the cAMP and MAPK pathways and other regulators like rop1 and hap1. Here we describe the identification of another putative Prf1 regulator, med1, the ortholog of the Aspergillus nidulans medusa (medA) transcription factor and show that it is required for mating and full virulence in U. maydis. med1 deletion mutants show both pre- and post-mating defects and are unresponsive to external pheromone. The expression of prf1 is down-regulated in Δmed1 compared to the wild type, suggesting that med1 is upstream of prf1. Additionally, indicative of a role in secondary metabolism regulation, deletion of the med1 gene de-represses the production of glycolipids in U. maydis.

  19. Molecular characterisation, evolution and expression of hypoxia-inducible factor in Aurelia sp.1.

    Science.gov (United States)

    Wang, Guoshan; Yu, Zhigang; Zhen, Yu; Mi, Tiezhu; Shi, Yan; Wang, Jianyan; Wang, Minxiao; Sun, Song

    2014-01-01

    The maintenance of physiological oxygen homeostasis is mediated by hypoxia-inducible factor (HIF), a key transcriptional factor of the PHD-HIF system in all metazoans. However, the molecular evolutionary origin of this central physiological regulatory system is not well characterized. As the earliest eumetazoans, Cnidarians can be served as an interesting model for exploring the HIF system from an evolutionary perspective. We identified the complete cDNA sequence of HIF-1α (ASHIF) from the Aurelia sp.1, and the predicted HIF-1α protein (pASHIF) was comprised of 674 amino acids originating from 2,025 bp nucleotides. A Pairwise comparison revealed that pASHIF not only possessed conserved basic helix-loop-helix (bHLH) and Per-Arnt-Sim (PAS) domains but also contained the oxygen dependent degradation (ODD) and the C-terminal transactivation domains (C-TAD), the key domains for hypoxia regulation. As indicated by sequence analysis, the ASHIF gene contains 8 exons interrupted by 7 introns. Western blot analysis indicated that pASHIF that existed in the polyps and medusa of Aurelia. sp.1 was more stable for a hypoxic response than normoxia.

  20. Aurelia aurita (Cnidaria) oocytes' contact plate structure and development.

    Science.gov (United States)

    Adonin, Leonid S; Shaposhnikova, Tatyana G; Podgornaya, Olga

    2012-01-01

    One of the A. aurita medusa main mesoglea polypeptides, mesoglein, has been described previously. Mesoglein belongs to ZP-domain protein family and therefore we focused on A.aurita oogenesis. Antibodies against mesoglein (AB RA47) stain the plate in the place where germinal epithelium contacts oocyte on the paraffin sections. According to its position, we named the structure found the "contact plate". Our main instrument was AB against mesoglein. ZP-domain occupies about half of the whole amino acid sequence of the mesoglein. Immunoblot after SDS-PAGE and AU-PAGE reveals two charged and high M(r) bands among the female gonad germinal epithelium polypeptides. One of the gonads' polypeptides M(r) corresponds to that of mesogleal cells, the other ones' M(r) is higher. The morphological description of contact plate formation is the subject of the current work. Two types of AB RA47 positive granules were observed during progressive oogenesis stages. Granules form the contact plate in mature oocyte. Contact plate of A.aurita oocyte marks its animal pole and resembles Zona Pellucida by the following features: (1) it attracts spermatozoids; (2) the material of the contact plate is synthesized by oocyte and stored in granules; (3) these granules and the contact plate itself contain ZP domain protein(s); (4) contact plate is an extracellular structure made up of fiber bundles similar to those of conventional Zona Pellucida.

  1. Structural and Developmental Disparity in the Tentacles of the Moon Jellyfish Aurelia sp.1.

    Science.gov (United States)

    Gold, David A; Nakanishi, Nagayasu; Hensley, Nicholai M; Cozzolino, Kira; Tabatabaee, Mariam; Martin, Michelle; Hartenstein, Volker; Jacobs, David K

    2015-01-01

    Tentacles armed with stinging cells (cnidocytes) are a defining trait of the cnidarians, a phylum that includes sea anemones, corals, jellyfish, and hydras. While cnidarian tentacles are generally characterized as structures evolved for feeding and defense, significant variation exists between the tentacles of different species, and within the same species across different life stages and/or body regions. Such diversity suggests cryptic distinctions exist in tentacle function. In this paper, we use confocal and transmission electron microscopy to contrast the structure and development of tentacles in the moon jellyfish, Aurelia species 1. We show that polyp oral tentacles and medusa marginal tentacles display markedly different cellular and muscular architecture, as well as distinct patterns of cellular proliferation during growth. Many structural differences between these tentacle types may reflect biomechanical solutions to different feeding strategies, although further work would be required for a precise mechanistic understanding. However, differences in cell proliferation dynamics suggests that the two tentacle forms lack a conserved mechanism of development, challenging the textbook-notion that cnidarian tentacles can be homologized into a conserved bauplan.

  2. Functional morphology and fluid interactions during early development of the scyphomedusa Aurelia aurita.

    Science.gov (United States)

    Feitl, K E; Millett, A F; Colin, S P; Dabiri, J O; Costello, J H

    2009-12-01

    Scyphomedusae undergo a predictable ontogenetic transition from a conserved, universal larval form to a diverse array of adult morphologies. This transition entails a change in bell morphology from a highly discontinuous ephyral form, with deep clefts separating eight discrete lappets, to a continuous solid umbrella-like adult form. We used a combination of kinematic, modeling, and flow visualization techniques to examine the function of the medusan bell throughout the developmental changes of the scyphomedusa Aurelia aurita. We found that flow around swimming ephyrae and their lappets was relatively viscous (1 < Re < 10) and, as a result, ephyral lappets were surrounded by thick, overlapping boundary layers that occluded flow through the gaps between lappets. As medusae grew, their fluid environment became increasingly influenced by inertial forces (10 < Re < 10,000) and, simultaneously, clefts between the lappets were replaced by organic tissue. Hence, although the bell undergoes a structural transition from discontinuous (lappets with gaps) to continuous (solid bell) surfaces during development, all developmental stages maintain functionally continuous paddling surfaces. This developmental pattern enables ephyrae to efficiently allocate tissue to bell diameter increase via lappet growth, while minimizing tissue allocation to inter-lappet spaces that maintain paddle function due to boundary layer overlap.

  3. Significance of different microalgal species for growth of moon jellyfish ephyrae, Aurelia sp.1

    Science.gov (United States)

    Zheng, Shan; Sun, Xiaoxia; Wang, Yantao; Sun, Song

    2015-10-01

    The scyphozoan Aurelia aurita (Linnaeus) sp. l., is a cosmopolitan species-complex which blooms seasonally in a variety of coastal and shelf sea environments around the world. The effects of different microalgal species on the growth of newly-released Aurelia sp.1 ephyrae were studied under laboratory conditions. We fed ephyrae with four different microalgal species (diatom, autotrophic dinoflagellate, heterotrophic dinoflagellate, and chlorophyta) plus Artemia nauplii for 12-24 d at 18°C. Results showed that the growth rate diverged significantly for Artemia nauplii compared to other food types. In addition, there was no significant variation between the growth rates for Skeletonema costatum and Prorocentrum donghaiense, and no significant variation was found in the growth rates for N. scintillans and P. subcordiformis. Artemia nauplii could support the energy requirement for the newly-released ephyrae to develop to meduase, and the ephyrae with Artemia nauplii showed a significant average growth rate of 25.85% d-1. Newly-released ephyrae could grow slightly with some species of microalgae in the earliest development stage. Chain diatom Skeletonema costatum and autotrophic dinoflagellate Prorocentrum donghaiense, could not support the growth of the ephyrae, while heterotrophic dinoflagellate Noctiluca scintillans and chlorophyta Platymonas subcordiformis could support the growth of the ephyrae. However, none of the ephyrae fed with the tested phytoplankton could mature to medusae.

  4. Cross-standard user description in mobile, medical oriented virtual collaborative environments

    Science.gov (United States)

    Ganji, Rama Rao; Mitrea, Mihai; Joveski, Bojan; Chammem, Afef

    2015-03-01

    By combining four different open standards belonging to the ISO/IEC JTC1/SC29 WG11 (a.k.a. MPEG) and W3C, this paper advances an architecture for mobile, medical oriented virtual collaborative environments. The various users are represented according to MPEG-UD (MPEG User Description) while the security issues are dealt with by deploying the WebID principles. On the server side, irrespective of their elementary types (text, image, video, 3D, …), the medical data are aggregated into hierarchical, interactive multimedia scenes which are alternatively represented into MPEG-4 BiFS or HTML5 standards. This way, each type of content can be optimally encoded according to its particular constraints (semantic, medical practice, network conditions, etc.). The mobile device should ensure only the displaying of the content (inside an MPEG player or an HTML5 browser) and the capturing of the user interaction. The overall architecture is implemented and tested under the framework of the MEDUSA European project, in partnership with medical institutions. The testbed considers a server emulated by a PC and heterogeneous user devices (tablets, smartphones, laptops) running under iOS, Android and Windows operating systems. The connection between the users and the server is alternatively ensured by WiFi and 3G/4G networks.

  5. The mitochondrial genome of Hydra oligactis (Cnidaria, Hydrozoa) sheds new light on animal mtDNA evolution and cnidarian phylogeny.

    Science.gov (United States)

    Kayal, Ehsan; Lavrov, Dennis V

    2008-02-29

    The 16,314-nuceotide sequence of the linear mitochondrial DNA (mtDNA) molecule of Hydra oligactis (Cnidaria, Hydrozoa)--the first from the class Hydrozoa--has been determined. This sequence contains genes for 13 energy pathway proteins, small and large subunit rRNAs, and methionine and tryptophan tRNAs, as is typical for cnidarians. All genes have the same transcriptional orientation and their arrangement in the genome is similar to that of the jellyfish Aurelia aurita. In addition, a partial copy of cox1 is present at one end of the molecule in a transcriptional orientation opposite to the rest of the genes, forming a part of inverted terminal repeat characteristic of linear mtDNA and linear mitochondrial plasmids. The sequence close to at least one end of the molecule contains several homonucleotide runs as well as small inverted repeats that are able to form strong secondary structures and may be involved in mtDNA maintenance and expression. Phylogenetic analysis of mitochondrial genes of H. oligactis and other cnidarians supports the Medusozoa hypothesis but also suggests that Anthozoa may be paraphyletic, with octocorallians more closely related to the Medusozoa than to the Hexacorallia. The latter inference implies that Anthozoa is paraphyletic and that the polyp (rather than a medusa) is the ancestral body type in Cnidaria.

  6. Complex neural architecture in the diploblastic larva of Clava multicornis (Hydrozoa, Cnidaria).

    Science.gov (United States)

    Piraino, Stefano; Zega, Giuliana; Di Benedetto, Cristiano; Leone, Antonella; Dell'Anna, Alessandro; Pennati, Roberta; Carnevali, Daniela Candia; Schmid, Volker; Reichert, Heinrich

    2011-07-01

    The organization of the cnidarian nervous system has been widely documented in polyps and medusae, but little is known about the nervous system of planula larvae, which give rise to adult forms after settling and metamorphosis. We describe histological and cytological features of the nervous system in planulae of the hydrozoan Clava multicornis. These planulae do not swim freely in the water column but rather crawl on the substrate by means of directional, coordinated ciliary movement coupled to lateral muscular bending movements associated with positive phototaxis. Histological analysis shows pronounced anteroposterior regionalization of the planula's nervous system, with different neural cell types highly concentrated at the anterior pole. Transmission electron microscopy of planulae shows the nervous system to be unusually complex, with a large, orderly array of sensory cells at the anterior pole. In the anterior half of the planula, the basiectodermal plexus of neurites forms an extensive orthogonal network, whereas more posteriorly neurites extend longitudinally along the body axis. Additional levels of nervous system complexity are uncovered by neuropeptide-specific immunocytochemistry, which reveals distinct neural subsets having specific molecular phenotypes. Together these observations imply that the nervous system of the planula of Clava multicornis manifests a remarkable level of histological, cytological, and functional organization, the features of which may be reminiscent of those present in early bilaterian animals. Copyright © 2011 Wiley-Liss, Inc.

  7. The non-Siphonophoran Hydrozoa (Cnidaria) of Salento, Italy with notes on their life-cycles: an illustrated guide.

    Science.gov (United States)

    Gravili, Cinzia; De Vito, Doris; Di Camillo, Cristina Gioia; Martell, Luis; Piraino, Stefano; Boero, Ferdinando

    2015-01-15

    The majority of Hydrozoa is represented by not readily noticeable, small species. In recent decades, however, taxonomic knowledge of the group has increased worldwide, with a significant number of investigations focused on the Mediterranean Sea. Over more than two decades, 115 species of hydrozoans were recorded from coastal waters along nearly 300 km of the Salento Peninsula (Apulia, Italy). For each species, records from different collections were merged into single sheets of a general database. For each species, the following information is reported: description, cnidome, biology, occurrence in Salento, worldwide distribution, and bibliography. Descriptions refer to the benthic hydroid stage and, when present, also to the planktonic medusa stage. The 115 species of Hydrozoa, recorded along the Salento coastline, represent 25% of the Mediterranean Hydrozoa fauna (totaling 461 species), and nearly 3% of 3,702 world's known species covered in a recent monograph. Four species are non-indigenous, three of them with invasive behavior (Clytia hummelincki, Clytia linearis, and Eudendrium carneum), and one species now very common (Eudendrium merulum) in Salento. The complete life cycle of Clytia paulensis (Vanhöffen, 1910) is described for the first time.

  8. Trends in the diversity, distribution and life history strategy of Arctic Hydrozoa (Cnidaria).

    Science.gov (United States)

    Ronowicz, Marta; Kukliński, Piotr; Mapstone, Gillian M

    2015-01-01

    This is the first attempt to compile a comprehensive and updated species list for Hydrozoa in the Arctic, encompassing both hydroid and medusa stages and including Siphonophorae. We address the hypothesis that the presence of a pelagic stage (holo- or meroplanktonic) was not necessary to successfully recolonize the Arctic by Hydrozoa after the Last Glacial Maximum. Presence-absence data of Hydrozoa in the Arctic were prepared on the basis of historical and present-day literature. The Arctic was divided into ecoregions. Species were grouped into distributional categories according to their worldwide occurrences. Each species was classified according to life history strategy. The similarity of species composition among regions was calculated with the Bray-Curtis index. Average and variation in taxonomic distinctness were used to measure diversity at the taxonomic level. A total of 268 species were recorded. Arctic-boreal species were the most common and dominated each studied region. Nineteen percent of species were restricted to the Arctic. There was a predominance of benthic species over holo- and meroplanktonic species. Arctic, Arctic-Boreal and Boreal species were mostly benthic, while widely distributed species more frequently possessed a pelagic stage. Our results support hypothesis that the presence of a pelagic stage (holo- or meroplanktonic) was not necessary to successfully recolonize the Arctic. The predominance of benthic Hydrozoa suggests that the Arctic could have been colonised after the Last Glacial Maximum by hydroids rafting on floating substrata or recolonising from glacial refugia.

  9. Trends in the diversity, distribution and life history strategy of Arctic Hydrozoa (Cnidaria.

    Directory of Open Access Journals (Sweden)

    Marta Ronowicz

    Full Text Available This is the first attempt to compile a comprehensive and updated species list for Hydrozoa in the Arctic, encompassing both hydroid and medusa stages and including Siphonophorae. We address the hypothesis that the presence of a pelagic stage (holo- or meroplanktonic was not necessary to successfully recolonize the Arctic by Hydrozoa after the Last Glacial Maximum. Presence-absence data of Hydrozoa in the Arctic were prepared on the basis of historical and present-day literature. The Arctic was divided into ecoregions. Species were grouped into distributional categories according to their worldwide occurrences. Each species was classified according to life history strategy. The similarity of species composition among regions was calculated with the Bray-Curtis index. Average and variation in taxonomic distinctness were used to measure diversity at the taxonomic level. A total of 268 species were recorded. Arctic-boreal species were the most common and dominated each studied region. Nineteen percent of species were restricted to the Arctic. There was a predominance of benthic species over holo- and meroplanktonic species. Arctic, Arctic-Boreal and Boreal species were mostly benthic, while widely distributed species more frequently possessed a pelagic stage. Our results support hypothesis that the presence of a pelagic stage (holo- or meroplanktonic was not necessary to successfully recolonize the Arctic. The predominance of benthic Hydrozoa suggests that the Arctic could have been colonised after the Last Glacial Maximum by hydroids rafting on floating substrata or recolonising from glacial refugia.

  10. Deep-sea epibiotic hydroids from the abyssal plain adjacent to the Kuril-Kamchatka Trench with description of Garveia belyaevi sp. nov. (Hydrozoa, Bougainvilliidae)

    Science.gov (United States)

    Stepanjants, Sofia D.; Chernyshev, Alexey V.

    2015-01-01

    Examination of material collected by the German-Russian KuramBio Deep-Sea Expedition to the abyssal plain adjacent to the Kuril-Kamchatka Trench revealed about 17 hydroid species, including two species presumably new to science. Before the KuramBio Expedition only fragments of the unidentified hydroids and Cryptolaria sp. were collected in the Kuril-Kamchatka Trench from depths exceeding 3000 m. Descriptions of three species of epibiotic hydroids (including one new species, Garveia belyaevi sp. nov.) are presented herein. A colony of G. belyaevi sp. nov. (the third deep-sea and deepest species of the wide distributed genus Garveia) was attached to the spines of unidentified irregular sea urchins from depths 5217 to 5229 m. Нalitholus (?) sp. (Hydrozoa, Anthoathecata) colonized the skin of spoon worms (Echiura) but could not be identified to species level because the mature medusa stage was absent in the material. An unidentified juvenile polyp (Pandeidae) was found on the bryozoan Tricitella minini attached to spines of irregular sea urchins Echinosigra amphora. Colonial sedentary organisms inhabiting abyssal plains with soft bottoms may colonize invertebrates which are seldom used as substrates for epibiota in shallow waters. Epibiosis among abyssal colonial invertebrates, though extremely poorly studied, appears to be rather frequent.

  11. Assemblages of hydroids (Cnidaria) from three seamounts near Bermuda in the western North Atlantic

    Science.gov (United States)

    Calder, Dale R.

    2000-06-01

    Three seamounts flanking the oceanic island of Bermuda were sampled for hydroids. Collecting was undertaken by submersible (SDL-1) and by dredge at depths between 48 and 107 m on the summits of Argus and Challenger banks. A shallower collection (rhodoliths, limestone reefs, and areas of calcareous sand. Hydroids were ubiquitous, but quite sparse, on firm substrata. None was collected on sandy bottoms. Of 45 species identified from the two oceanic banks, over half (25) were found on both. On Bowditch Seamount, samples were obtained at depths between 1285 and 1381 m by dredge and grab. Of four species found, only one ( Filellum serratum) occurred in shallower collections from Argus and Challenger banks. Most species (43 of 48) from the three seamounts have been reported elsewhere in the Western Atlantic Tropical region, and many (38 of 48) are known from Bermuda. No endemics were discovered, and no relicts or exotics were recognized. Gonophores in >70% of the species are fixed sporosacs instead of free medusae. This conforms with a hypothesis that invertebrates of oceanic islands and seamounts tend to have short-lived pelagic larval stages, ensuring the greatest retention and conservation of propagules.

  12. Delineating native and invasive plant functional groups in shrub-steppe vegetation using bidirectional reflectance

    Science.gov (United States)

    Naupari, Javier A.; Vierling, Lee A.; Eitel, Jan U. H.

    2013-01-01

    Delineating invasive and native plant types using remote sensing is important for managing rangelands. Remote characterization of rangeland vegetation often utilizes only the nadir view, which can be complicated by background soil reflectance. We therefore collected bidirectional radiometric measurements on a shrub-steppe vegetated landscape throughout the mid- to late-growing season to: (1) quantify the BRFs of four rangeland vegetation functional groups (native shrub, native grasses, invasive annual grasses, and forbs), and (2) examine ways in which bidirectional reflectance values may help delineate native and invasive vegetation types. We found that the invasive grass medusahead rye (Taeniatherum caput-medusae [L.] Nevski) could be discriminated from other vegetation types at nadir and across four forward-viewing zenith angles because this species exhibited structural changes when leaf orientation changed from erectophile to planophile during and after the filling of seedheads. We also confirmed that native shrubs exhibited the highest anisotropy in all wavebands, as the relatively complex structure of the shrub canopy and concomitant shadowing greatly affected values of normalized difference vegetation index across all view angles. In order to delineate rangeland vegetation types at coarser scales, further study is needed to quantify the spectral angular signatures of these plant groups using satellite-based images.

  13. Molecular phylogeny of Atractus (Serpentes, Dipsadidae), with emphasis on Ecuadorian species and the description of three new taxa

    Science.gov (United States)

    Arteaga, Alejandro; Mebert, Konrad; Valencia, Jorge H.; Cisneros-Heredia, Diego F.; Peñafiel, Nicolás; Reyes-Puig, Carolina; Vieira-Fernandes, José L.; Guayasamin, Juan M.

    2017-01-01

    Abstract We present a molecular phylogeny of snake genus Atractus, with an improved taxon sampling that includes 30 of the 140 species currently recognized. The phylogenetic tree supports the existence of at least three new species in the Pacific lowlands and adjacent Andean slopes of the Ecuadorian Andes, which we describe here. A unique combination of molecular, meristic and color pattern characters support the validity of the new species. With the newly acquired data, we propose and define the Atractus iridescens species group, as well as redefine the Atractus roulei species group. The species Atractus iridescens is reported for the first time in Ecuador, whereas Atractus bocourti and Atractus medusa are removed from the herpetofauna of this country. We provide the first photographic vouchers of live specimens for Atractus multicinctus, Atractus paucidens and Atractus touzeti, along with photographs of 19 other Ecuadorian Atractus species. The current status of Atractus occidentalis and Atractus paucidens is maintained based on the discovery of new material referable to these species. With these changes, the species number reported in Ecuador increases to 27, a number that is likely to increase as material not examined in this work becomes available and included in systematic studies. PMID:28769604

  14. TECHNIQUES DE MYSTIFICATION DU SACRÉ DANS LA LITTÉRATURE MYTHOLOGISANTE DE LA GRÈCE ANTIQUE

    Directory of Open Access Journals (Sweden)

    Dr. Maria-Luiza Oancea (Dumitru

    2008-10-01

    Full Text Available This paper entails the sacred mytification motif, a subject hardly debated, but extremely challenging, that we can identify in several myths and episodes of the ancient Greek mythology literature (Thanatos-Sisyphus myth, Sirens-Odysseus or Sirens-Orpheus myth, Polifem-Odysseus myth, Gorgo Medusa-Perseus myth, etc.. Our essay starts from the general thesis that a direct confrontation with the Sacred is essentially impossible, making the Sacred almost always manipulated (cf. R. Caillois, R. Girard, M. Eliade. It is also the reason why, in our opinion, the Greek Sacred is defined mostly as hagios ("forbidden for people to touch it " than hieros ("inspired by divine grace". This mystification or manipulation of the Sacred manifests in the examples mentioned above as linking (paralysis or avoidance, as incantation or spell, as drinking, as replacement or blindness, but often, it involves an intermediate recognized as a sacrificed animal, in a defence element (such as shield, mirror, eye, wall, rampart, or the appearance of armor-(divine gift or armor-disguise. We believe that the tendency of handling sacred is in fact due to the natural human impulse of socializing with this unknown, scary, monstrous Sacred in the etymological sense.

  15. A biomimetic robotic jellyfish (Robojelly) actuated by shape memory alloy composite actuators.

    Science.gov (United States)

    Villanueva, Alex; Smith, Colin; Priya, Shashank

    2011-09-01

    An analysis is conducted on the design, fabrication and performance of an underwater vehicle mimicking the propulsion mechanism and physical appearance of a medusa (jellyfish). The robotic jellyfish called Robojelly mimics the morphology and kinematics of the Aurelia aurita species. Robojelly actuates using bio-inspired shape memory alloy composite actuators. A systematic fabrication technique was developed to replicate the essential structural features of A. aurita. Robojelly's body was fabricated from RTV silicone having a total mass of 242 g and bell diameter of 164 mm. Robojelly was able to generate enough thrust in static water conditions to propel itself and achieve a proficiency of 0.19 s(-1) while the A. aurita achieves a proficiency of around 0.25 s(-1). A thrust analysis based on empirical measurements for a natural jellyfish was used to compare the performance of the different robotic configurations. The configuration with best performance was a Robojelly with segmented bell and a passive flap structure. Robojelly was found to consume an average power on the order of 17 W with the actuators not having fully reached a thermal steady state.

  16. Genomic analysis of immune response against Vibrio cholerae hemolysin in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Surasri N Sahu

    Full Text Available Vibrio cholerae cytolysin (VCC is among the accessory V. cholerae virulence factors that may contribute to disease pathogenesis in humans. VCC, encoded by hlyA gene, belongs to the most common class of bacterial toxins, known as pore-forming toxins (PFTs. V. cholerae infects and kills Caenorhabditis elegans via cholerae toxin independent manner. VCC is required for the lethality, growth retardation and intestinal cell vacuolation during the infection. However, little is known about the host gene expression responses against VCC. To address this question we performed a microarray study in C. elegans exposed to V. cholerae strains with intact and deleted hlyA genes.Many of the VCC regulated genes identified, including C-type lectins, Prion-like (glutamine [Q]/asparagine [N]-rich-domain containing genes, genes regulated by insulin/IGF-1-mediated signaling (IIS pathway, were previously reported as mediators of innate immune response against other bacteria in C. elegans. Protective function of the subset of the genes up-regulated by VCC was confirmed using RNAi. By means of a machine learning algorithm called FastMEDUSA, we identified several putative VCC induced immune regulatory transcriptional factors and transcription factor binding motifs. Our results suggest that VCC is a major virulence factor, which induces a wide variety of immune response- related genes during V. cholerae infection in C. elegans.

  17. UV-visible spectroscopic and electrochemical study of the complex formation between Fe(II) and 5-amino-1,10-phenantroline (5-Aphen) in aqueous solution.

    Science.gov (United States)

    Lozano-Camargo, María Luisa; Rojas-Hernández, Alberto; Gómez-Hernández, Martín; Pacheco-Hernández, Ma de Lourdes; Galicia, Laura; Ramírez-Silva, María Teresa

    2007-06-15

    The system Fe(II)-5-Aphen-H(2)O was studied. The spectroscopic and electrochemical results show that only one stable complex between Fe(II) and 5-Aphen forms, having a 1:3 stoichiometric ratio. The spectrophotometry study allowed determination of the formation constant of the complex (logbeta(3)=23.42+/-0.06). Also, the stability of the complex was evaluated as a function of pH; it was found that it decomposed at low pH values depending on the concentration and a pseudo-first order kinetics constant associated with k'=0.011min(-1). The results are in agreement with the electrochemical behaviour observed in the system, which indicated that at pH 1.33 the destruction of the complex [Fe(5-Aphen)3](2+) took place as a function of time; however, when the experiments were carried out at pH 6.19 the complex was stable. The thermodynamic data obtained through the use of MEDUSA allowed construction of predominance zone diagrams of the system Fe(II)-5-Aphen-H(2)O under the experimental conditions used. The thermodynamic results represented in the PZD describe the experimental behaviour reported in this work.

  18. Application of ray theory to propagation of low frequency noise from wind turbines

    Science.gov (United States)

    Hawkins, James A.

    1987-01-01

    Ray theory is used to explain data from two experiments (1985 and 1985) on the propagation of low frequency sound generated by the WTS-4 wind turbine. Emphasis is on downwind data, but some upwind measurements taken during the 1985 experiment are also considered. General ray theory for a moving medium is reviewed and ray equations obtained. Restrictions are introduced simplifying the equations and permitting the use of a ray theory program MEDUSA, the computed propagation loss curve of which is compared to the measurements. Good qualitative agreement is obtained with 1984 downwind data. The results indicate that the downwind sound field is that of a near-ground sound channel. Although more scatter is seen in the 1985 data, agreement between theory and data is also good. In particular, the position and magnitude of the jump in the sound levels associated with the beginning of the sound channel is correctly predicted. The theoretical explanation of the upwind data is less successful. Ray theory calculations indicate the formation of a shadow zone that, in fact, does not occur. While no sharp shadow zone is apparent in the data, the general expectation (based on ray theory) that sound levels should be much reduced upwind is confirmed by the data.

  19. An imaging and spectroscopic study of the planetary nebulae in NGC 5128 (Centaurus A): Planetary nebulae catalogues

    CERN Document Server

    Walsh, J R; Walton, N A

    2015-01-01

    Imaging and spectroscopic observations of planetary nebulae (PNe) in the nearest large elliptical galaxy NGC 5128 (Centaurus A), were obtained to find more PNe and measure their radial velocities. NTT imaging was obtained in 15 fields in NGC 5128 over an area of about 1 square degree with EMMI using [O III] and off-band filters. Newly detected sources, combined with literature PNe, were used as input for VLT FLAMES multi-fibre spectroscopy in MEDUSA mode. Spectra of the 4600-5100A region were analysed and velocities measured based on emission lines of [O III]4959,5007A and often H-beta. The chief results are catalogues of 1118 PN candidates and 1267 spectroscopically confirmed PNe in NGC 5128. The catalogue of PN candidates contains 1060 PNe discovered with EMMI imaging and 58 from literature surveys. The spectroscopic PN catalogue has FLAMES radial velocity and emission line measurements for 1135 PNe, of which 486 are new. Another 132 PN radial velocities are available from the literature. For 629 PNe observ...

  20. Noncovalent PEGylation via Lectin-Glycopolymer Interactions.

    Science.gov (United States)

    Antonik, Paweł M; Eissa, Ahmed M; Round, Adam R; Cameron, Neil R; Crowley, Peter B

    2016-08-08

    PEGylation, the covalent modification of proteins with polyethylene glycol, is an abundantly used technique to improve the pharmacokinetics of therapeutic proteins. The drawback with this methodology is that the covalently attached PEG can impede the biological activity (e.g., reduced receptor-binding capacity). Protein therapeutics with "disposable" PEG modifiers have potential advantages over the current technology. Here, we show that a protein-polymer "Medusa complex" is formed by the combination of a hexavalent lectin with a glycopolymer. Using NMR spectroscopy, small-angle X-ray scattering (SAXS), size exclusion chromatography, and native gel electrophoresis it was demonstrated that the fucose-binding lectin RSL and a fucose-capped polyethylene glycol (Fuc-PEG) form a multimeric assembly. All of the experimental methods provided evidence of noncovalent PEGylation with a concomitant increase in molecular mass and hydrodynamic radius. The affinity of the protein-polymer complex was determined by ITC and competition experiments to be in the micromolar range, suggesting that such systems have potential biomedical applications.

  1. A new, unique signature of the true cusp

    Directory of Open Access Journals (Sweden)

    W. R. Keith

    Full Text Available The "cusp proper" is generally understood to be the region enclosed by the outermost magnetospheric field lines as they map to low altitudes. It is therefore a weak-field region with continuous contact with magnetosheath plasma. Data from the recent Astrid-2 Swedish microsatellite are presented which show a new, unique signature (dubbed the "true cusp" during cusp crossings that can now be shown to be consistently present and with which one can redefine the physical meaning and topology of the cusp. Similar crossings made by the DE-2, UARS and DMSP-F10 satellites also show this same, unique signature although in most cases the spatial resolution was much less than that of the Astrid-2 MEDUSA spectrometer. The presence of concurrent features of the same scale size as the plasma in the energetic particle, field and wave power data shows that this is a real structural feature and not a coincidental structure among plasma instruments. The persistence of this feature may lend new insight into the dynamics of the cusp and magnetospheric particle entry.

    Key words. Magnetospheric physics (magnetopause, cusp, arid boundary layers; magnetospheric configuration and dynamics

  2. Molecular phylogeny of Atractus (Serpentes, Dipsadidae), with emphasis on Ecuadorian species and the description of three new taxa.

    Science.gov (United States)

    Arteaga, Alejandro; Mebert, Konrad; Valencia, Jorge H; Cisneros-Heredia, Diego F; Peñafiel, Nicolás; Reyes-Puig, Carolina; Vieira-Fernandes, José L; Guayasamin, Juan M

    2017-01-01

    We present a molecular phylogeny of snake genus Atractus, with an improved taxon sampling that includes 30 of the 140 species currently recognized. The phylogenetic tree supports the existence of at least three new species in the Pacific lowlands and adjacent Andean slopes of the Ecuadorian Andes, which we describe here. A unique combination of molecular, meristic and color pattern characters support the validity of the new species. With the newly acquired data, we propose and define the Atractus iridescens species group, as well as redefine the Atractus roulei species group. The species Atractus iridescens is reported for the first time in Ecuador, whereas Atractus bocourti and Atractus medusa are removed from the herpetofauna of this country. We provide the first photographic vouchers of live specimens for Atractus multicinctus, Atractus paucidens and Atractus touzeti, along with photographs of 19 other Ecuadorian Atractus species. The current status of Atractus occidentalis and Atractus paucidens is maintained based on the discovery of new material referable to these species. With these changes, the species number reported in Ecuador increases to 27, a number that is likely to increase as material not examined in this work becomes available and included in systematic studies.

  3. Jellyfish: Special Tools for Biological Research on Earth and in Space

    Science.gov (United States)

    Spangenberg, Dorothy B.

    1991-01-01

    The most intriguing nature of the jellyfish polyps is their ability to metamorphose, giving rise to tiny immature medusae called ephyrae which have a different form or shape from the polyps. The Aurelia Metamorphosis Test System was used to determine the subtle effects of hydrocarbons found in oil spills and the effects of X-irradiation on developing ephyrae. Currently, this test system is used to determine the effects of the gravity-less environment of outer space on the development and behavior of ephyrae. For this purpose, the effects of clinostat rotation on development of the ephyrae and their gravity receptor are being studied. The behavior of the ephyrae during 0 gravity achieved for short intervals of 30 seconds in parabolic flight is examined. The developing ephyrae and the mature ephyrae are exposed to gravity-less environment of outer space via a six or seven day shuttle experiment. If gravity receptors do form in outer space, they will be studied in detail using various types of microscopes, including the electron microscope, to determin whether they developed normally in space as compared with control on Earth.

  4. Extract from the zooxanthellate jellyfish Cotylorhiza tuberculata modulates gap junction intercellular communication in human cell cultures.

    Science.gov (United States)

    Leone, Antonella; Lecci, Raffaella Marina; Durante, Miriana; Piraino, Stefano

    2013-05-22

    On a global scale, jellyfish populations in coastal marine ecosystems exhibit increasing trends of abundance. High-density outbreaks may directly or indirectly affect human economical and recreational activities, as well as public health. As the interest in biology of marine jellyfish grows, a number of jellyfish metabolites with healthy potential, such as anticancer or antioxidant activities, is increasingly reported. In this study, the Mediterranean "fried egg jellyfish" Cotylorhiza tuberculata (Macri, 1778) has been targeted in the search forputative valuable bioactive compounds. A medusa extract was obtained, fractionated, characterized by HPLC, GC-MS and SDS-PAGE and assayed for its biological activity on breast cancer cells (MCF-7) and human epidermal keratinocytes (HEKa). The composition of the jellyfish extract included photosynthetic pigments, valuable ω-3 and ω-6 fatty acids, and polypeptides derived either from jellyfish tissues and their algal symbionts. Extract fractions showed antioxidant activity and the ability to affect cell viability and intercellular communication mediated by gap junctions (GJIC) differentially in MCF-7 and HEKa cells. A significantly higher cytotoxicity and GJIC enhancement in MCF-7 compared to HEKa cells was recorded. A putative action mechanism for the anticancer bioactivity through the modulation of GJIC has been hypothesized and its nutraceutical and pharmaceutical potential was discussed.

  5. De Novo Assembly of the Transcriptome of Turritopsis, a Jellyfish that Repeatedly Rejuvenates.

    Science.gov (United States)

    Hasegawa, Yoshinori; Watanabe, Takashi; Takazawa, Masaki; Ohara, Osamu; Kubota, Shin

    2016-08-01

    In most animals, aging is an irreversible process; however the species Turritopsis sp. has been observed to undergo a rejuvenation process as many as 14 times. In the present study, we used multiplexed RNA libraries to obtain the transcriptome from four developmental stages (St) of Turritopsis sp., including (I) immature medusa, (II) dumpling, (III) dumpling with a short stolon, and (IV) polyp, which had recently rejuvenated. A total of 4.02 billion paired-end reads were assembled de novo, yielding 90,327 contigs. Our analyses revealed that significant blast hits were recovered for 74% of the assembled contigs, and 19% were successfully annotated with gene ontology (GO) terms. A BLAST search demonstrated that 32% of the contigs were most similar to Hydra vulgarissequences. Raw reads from each sample were mapped against the contigs to find St-specific genes. This represents the first comprehensive set of de novo transcriptome data for this species, which may provide clues toward a better understanding of cyclical rejuvenation in multicellular animals.

  6. Variation in lethality and effects of two Australian chirodropid jellyfish venoms in fish.

    Science.gov (United States)

    Kintner, Anna H; Seymour, Jamie E; Edwards, Susan L

    2005-11-01

    The North Queensland chirodropid box jellyfish Chironex fleckeri and Chiropsalmus sp. share similar nematocyst composition and the same prey of Acetes australis shrimps in their early medusa stages; however, as C. fleckeri individuals reach larger size, the animals add fish to their diet and their complement of nematocyst types changes, allowing larger doses of venom to be delivered to prey. This study demonstrated that the venoms of the two species differ as well: despite similar effects previously documented in crustacean prey models, the two had widely different cardiac and lethal effects in fish, with C. fleckeri being substantially more potent in its ability to cause death. Comparisons between the venom delivery abilities of the two species showed that the change in nematocysts of C. fleckeri cannot alone account for its ontogenetic shift to prey fish; instead, its prey ecology clearly necessitates it having venom capable of acting efficiently to cause death in fish. Although this venom is almost certainly produced at greater metabolic cost to the animal than the less-lethal venom of Chiropsalmus sp., owing to its greater molecular protein complexity, it confers the advantage of increased caloric intake from fish prey, facilitating larger size and potentially greater reproductive output of C. fleckeri over Chiropsalmus sp.

  7. Preliminary observations on the response of Chironex fleckeri (Cnidaria: Cubozoa: Chirodropida) to different colors of light.

    Science.gov (United States)

    Gershwin, Lisa-Ann; Dawes, Peter

    2008-08-01

    Cubozoans are well known for their attraction to light and light-colored objects. Two highly venomous types are a public safety concern in Australian waters and elsewhere: Chironex fleckeri, long considered the world's deadliest animal and colloquially called the box jellyfish; and the irukandjis, a group of at least 10 species that cause various degrees of debilitating illness. We were asked by the tourism industry whether there might be a color of light that box jellyfish and irukandjis are not attracted to, such that nighttime diving activities might pose less risk of being stung. Our preliminary trials with Chironex fleckeri indicated a marked positive response to lights of white, red, yellow, green, orange, and blue. All colors elicited a strong and directed attraction to light; however, medusae slowed down their pulsation rate, streamed out their tentacles, and performed a series of figure-eight patterns back and forth through the lighted area when exposed to blue light, which we interpreted as feeding behavior. This compares curiously with a report subsequent to our testing, in which the small, mangrove-inhabiting cubomedusa Tripedalia cystophora and the beach-dwelling Chiropsella bronzie demonstrate a peak sensitivity to blue-green light in the region of 500 nm, and that the former is behaviorally attracted to blue and green light, but ignores red. This leaves open the possibility that Irukandji species, which are more closely related to Tripedalia than to Chironex, may be blind to red.

  8. Modelling Chromospheric Line Profiles in NGC2808: Evidence of Mass Loss from RGB Stars

    CERN Document Server

    Mauas, P J D; Pasquini, L

    2006-01-01

    In this study we test the possibility that the asymmetry in the profiles of the H-alpha and Ca II K lines in red giant stars is due to the presence of an active chromosphere rather than to mass loss. To this end, we compare line profiles computed using relevant model chromospheres to profiles of the H-alpha and Ca II K lines observed in five red giant stars of the globular cluster NGC 2808. The spectra were taken with FLAMES during Science Verification, using the UVES mode at high resolution (R=43,000) for the H-alpha line, and GIRAFFE in MEDUSA mode (R=20,000) for the Ca II K line. We find that the observed profiles are better described if a negative (outward) velocity field is included in the model chromospheres. This leads to mass loss rates of a few 10**(-9) solar masses per year, very close to the requirements of the stellar evolution theory.

  9. The studies about the photosynthetic response of the four desert plants%四种荒漠植物的光合响应

    Institute of Scientific and Technical Information of China (English)

    邓雄; AndreaFoezki; 等

    2003-01-01

    Populus euphratica Oliv.、Alhagi sparsifolia B.Keller et Shap.、Tamarix ramosissima Lbd. and Calligonum caput-medusae Schrenk., are all constructive plants in Taklamaka Desert. Responses of photosynthetic parameters of the four desert plants to changes light intensity and CO2 concentration were studied, the results are as follows:①Among the four plants, A. sparsifolia has the highest photorespiration rate (Rp) and CO2 compensation point(Γ), and it has the lowest maximal net assimilation rate(Am) and water use efficiency (WUE) in irradiance responses. On the contrary, as a C4 plant, C.caput-medusa has a lower Rp and Γ,and a significantly higher An, light compensation point(LCP) and light saturation point(LSP) than those of the other plants(P≤0.05), it also had the highest WUE owed much to its very low transpiration rate(E).②According to their LCP and respiration in dark(Rd), we arranged them from sunny to less: C.caput-medusa, A. sparsifolia,T. ramosissima, P. euphratica. And our results also favored the view that relative shade-tolerant plants have higher An in weak light environment than those sun ones.③Further studies are expected to be done on if T. ramosissima has a narrow temperature niche or less stomata sensitivity to irradiance than the other plants. ④Having present a striking contrast between the previously reported results and ours, we suggest P.populus could be inducible for some C4-like characteristics in some special environments, growth stages or under some special treatments.%研究了胡杨(Populus euphratica Oliv)、疏叶骆驼刺(Alhagi sparsifolia B.Keller et Shap)、多枝柽柳(Tamarix ramosissima Lbd)和头状沙拐枣(Calligonum caput-medusae Schrenk)等四种塔克拉玛干荒漠植物的光合响应曲线,结果表明:①四种植物中,疏叶骆驼刺光呼吸(Rp)和CO2补偿点(Γ)最高,净光合速率(An)以及水分利用效率(WUE)最低;而C4植物头状沙拐枣无论Rp还是Γ都最低,它的An、光补偿点(LCP)

  10. Remote sensing to monitor monotypic weed patches in semi-arid grasslands

    Science.gov (United States)

    Planck, Laura

    Remote sensing technology has great potential for mapping weed distributions. Fine-scale weed distribution maps can provide means to evaluate the success of weed control methods, to guide selection of future control methods, and to examine factors that influence the creation and persistence of monotypic weed patches. Here I examined the effectiveness of different classification approaches in detecting dense monotypic patches of the late-phenology weeds Taeniatherum caput-medusae (medusahead) and Aegilops triuncialis (barbed goatgrass), among cool-season forage grasses (Bromus spp. and Avena spp.) across multiple years in semi-arid rangelands in northern California (USA). I found that color infrared photographs acquired at two key phenological periods produced more accurate classifications than those based on one image alone, and that inclusion of training sites did not improve the overall accuracy of a classification. I also examined the association of remnant litter with transitions in species dominance in medusahead, goatgrass or forage patches. Persistence of goatgrass-dominated patches was correlated with the amount of remnant litter present, but surprisingly that of medusahead was not, suggesting a potential need for different strategies in control of these two noxious species. Overall, this study shows that remote sensing can be used to create weed distribution maps of phenologically distinct species, and help us further understand community response to invasion and evaluate the effectiveness of management treatments.

  11. THE POTENTIAL OF γ-RAY SPECTROSCOPY FOR SOIL PROXIMAL SURVEY IN CLAYEY SOILS

    Directory of Open Access Journals (Sweden)

    Simone Priori

    2014-01-01

    Full Text Available Gamma-ray spectroscopy surveys the intensity and distribution of γ-rays emitted from radionuclides of soils and bedrocks. The most important radionuclides of soils and rocks are: 40K, 232Th, 238U and 137Cs, the latter due to Chernobyl burst or radioactive pollution. Distribution and quantity of these radionuclides into the soil is strictly linked to parent material mineralogy and soil cation exchange capacity. The aim of this work is to show the makings of γ-ray spectroscopy proximal survey within experimental fields with clayey soils in western Sicily.The γ-ray spectrometer used for the fieldwork was “The Mole”, made by “The Soil Company”, “Medusa system” and the University of Groningen, from The Netherlands. During the survey of eight experimental fields, 55 soil samples were collected for laboratory analysis of particle size distribution, calcium carbonate, organic carbon and total nitrogen content. The results of the work showed the statistical correlations between soil features and γ-ray data. 

  12. Fixational eye movements in the earliest stage of metazoan evolution.

    Directory of Open Access Journals (Sweden)

    Jan Bielecki

    Full Text Available All known photoreceptor cells adapt to constant light stimuli, fading the retinal image when exposed to an immobile visual scene. Counter strategies are therefore necessary to prevent blindness, and in mammals this is accomplished by fixational eye movements. Cubomedusae occupy a key position for understanding the evolution of complex visual systems and their eyes are assumedly subject to the same adaptive problems as the vertebrate eye, but lack motor control of their visual system. The morphology of the visual system of cubomedusae ensures a constant orientation of the eyes and a clear division of the visual field, but thereby also a constant retinal image when exposed to stationary visual scenes. Here we show that bell contractions used for swimming in the medusae refresh the retinal image in the upper lens eye of Tripedalia cystophora. This strongly suggests that strategies comparable to fixational eye movements have evolved at the earliest metazoan stage to compensate for the intrinsic property of the photoreceptors. Since the timing and amplitude of the rhopalial movements concur with the spatial and temporal resolution of the eye it circumvents the need for post processing in the central nervous system to remove image blur.

  13. VACTERL (vertebral anomalies, anal atresia or imperforate anus, cardiac anomalies, tracheoesophageal fistula, renal and limb defect spectrum presenting with portal hypertension: a case report

    Directory of Open Access Journals (Sweden)

    Losa Ignatius

    2010-05-01

    Full Text Available Abstract Introduction We report for the first time a unique case of VACTERL (vertebral anomalies, anal atresia or imperforate anus, cardiac anomalies, tracheoesophageal fistula, renal and limb defect spectrum associated with portal hypertension. The occurrence of both VACTERL spectrum and extrahepatic portal hypertension in a patient has not been reported in the literature. We examined whether or not there was any association between extrahepatic portal hypertension and VACTERL spectrum. Case Presentation A two-and-half-year-old Caucasian girl with VACTERL spectrum presented with hematemesis and abdominal distension. She had caput medusae, ascites, splenomegaly, gastric and esophageal varices. Her liver function tests were within normal limits. Magnetic resonance imaging of the liver with contrast showed a thready portal vein with collateral vessels involving both right and left portal veins without intrahepatic duct dilation. Conclusion A thready portal vein, with features of extrahepatic portal hypertension, is a rare non- VACTERL-type defect in patients with VACTERL spectrum. Understandably, clinicians should give low priority to looking for portal hypertension in VACTERL spectrum patients presenting with gastrointestinal bleeding. However before routinely looking for a thready portal vein and/or extrahepatic portal hypertension in asymptomatic VACTERL spectrum patients, we need further evidence to support this rare association.

  14. Iirimaale : [luuletused] / Percy Bysshe Shelley ; tlk. Minni Nurme, Ants, Oras

    Index Scriptorium Estoniae

    Shelley, Percy Bysshe

    2006-01-01

    Sisu: Iirimaale ; Armastuse roos ; Harrietile ; Muutlikkus ; Vangist vabanenud sõbrale ; Minevik ; Byronile ; Kaduvik ; Laul : "Maa magas, külm kui surm..." ; Hümn vaimsele ilule ; Laul : "Too aeg on läind, mu armsam, läind..." ; Ozymandias ; Sonett ; India serenaad ; Leonardo da Vinci Medusa Firenze kunstikogus ; Armu filosoofia ; Ood läänetuulele ; Mary Shelleyle ; Laul briti meestele ; Uus rahvushümn ; Inglismaa 1819. a. ; Ära madu ärata ; Head ööd! ; Pilv ; Apolloni hümn ; Paani hümn ; Lõoke ; Vabadus ; Suvi ja talv ; Maailmarändurid ; Küsimus ; Aeg, mis hajus ; Ööle ; -le : "Üht sõna on labastand suud..." ; -le : "Kui kirg kord mööduks, aga jääks..." ; Õhtu Ponte al Marel, Pisas ; Mälestus ; Muusika ; Aeg ; Põgenejad ; Ma olla kuningas ei tahaks ; "Homne päev, kus oled praegu..." ; "Laps rahus kord on emaihus..." ; Üksik lind ; "Kui lamp pihuks langend..." ; Epitaaf ; Kutse Janeþile ; Tähed vilkusid valgust ; Leinalaul ; Pühendus. Eluloolisi andmeid autori kohta lk. 389

  15. Hunting in bioluminescent light: Vision in the nocturnal box jellyfish Copula sivickisi

    Directory of Open Access Journals (Sweden)

    Anders eGarm

    2016-03-01

    Full Text Available Cubomedusae all have a similar set of six eyes on each of their four rhopalia. Still, there is a great variation in activity patterns with some species being strictly day active while others are strictly night active. Here we have examined the visual ecology of the medusa of the night active Copula sivickisi from Okinawa using optics, morphology, electrophysiology, and behavioural experiments. We found the lenses of both the upper and the lower lens eyes to be image forming but under-focused, resulting in low spatial resolution in the order of 10 – 15 degrees. The photoreceptor physiology is similar in the two lens eyes and they have a single opsin peaking around 460 nm and low temporal resolution with a flicker fusion frequency (fff of 2.5 Hz indicating adaptions to vision in low light intensities. Further, the outer segments have fluid filled swellings, which may concentrate the light in the photoreceptor membrane by total internal reflections, and thus enhance the signal to noise ratio in the eyes. Finally our behavioural experiments confirmed that the animals use vision when hunting. When they are active at night they seek out high prey-concentration by visual attraction to areas with abundant bioluminescent flashes triggered by their prey.

  16. Long-term fluctuations in circalunar Beach aggregations of the box jellyfish Alatina moseri in Hawaii, with links to environmental variability.

    Directory of Open Access Journals (Sweden)

    Luciano M Chiaverano

    Full Text Available The box jellyfish Alatina moseri forms monthly aggregations at Waikiki Beach 8-12 days after each full moon, posing a recurrent hazard to swimmers due to painful stings. We present an analysis of long-term (14 years: Jan 1998- Dec 2011 changes in box jellyfish abundance at Waikiki Beach. We tested the relationship of beach counts to climate and biogeochemical variables over time in the North Pacific Sub-tropical Gyre (NPSG. Generalized Additive Models (GAM, Change-Point Analysis (CPA, and General Regression Models (GRM were used to characterize patterns in box jellyfish arrival at Waikiki Beach 8-12 days following 173 consecutive full moons. Variation in box jellyfish abundance lacked seasonality, but exhibited dramatic differences among months and among years, and followed an oscillating pattern with significant periods of increase (1998-2001; 2006-2011 and decrease (2001-2006. Of three climatic and 12 biogeochemical variables examined, box jellyfish showed a strong, positive relationship with primary production, >2 mm zooplankton biomass, and the North Pacific Gyre Oscillation (NPGO index. It is clear that that the moon cycle plays a key role in synchronizing timing of the arrival of Alatina moseri medusae to shore. We propose that bottom-up processes, likely initiated by inter-annual regional climatic fluctuations influence primary production, secondary production, and ultimately regulate food availability, and are therefore important in controlling the inter-annual changes in box jellyfish abundance observed at Waikiki Beach.

  17. Statolith Morphometrics Can Discriminate among Taxa of Cubozoan Jellyfishes.

    Directory of Open Access Journals (Sweden)

    Christopher J Mooney

    Full Text Available Identification of potentially harmful cubomedusae is difficult due to their gelatinous nature. The only hard structure of medusae, the statolith, has the potential to provide robust measurements for morphometric analysis. Traditional morphometric length to width ratios (L: W and modern morphometric Elliptical Fourier Analysis (EFA were applied to proximal, oral and lateral statolith faces of 12 cubozoan species. EFA outperformed L: W as L: W did not account for the curvature of the statolith. Best discrimination was achieved with Canonical Discriminant Analysis (CDA when analysing proximal + oral + lateral statolith faces in combination. Normalised Elliptical Fourier (NEF coefficients classified 98% of samples to their correct species and 94% to family group. Statolith shape agreed with currently accepted cubozoan taxonomy. This has potential to assist in identifying levels of risk and stock structure of populations in areas where box jellyfish envenomations are a concern as the severity of envenomation is family dependent. We have only studied 12 (27% of the 45 currently accepted cubomedusae, but analyses demonstrated that statolith shape is an effective taxonomic discriminator within the Class.

  18. A biomimetic robotic jellyfish (Robojelly) actuated by shape memory alloy composite actuators

    Energy Technology Data Exchange (ETDEWEB)

    Villanueva, Alex; Smith, Colin; Priya, Shashank, E-mail: spriya@vt.edu [Center for Intelligent Material Systems and Structures (CIMSS), Virginia Tech, Blacksburg, VA 24061 (United States)

    2011-09-15

    An analysis is conducted on the design, fabrication and performance of an underwater vehicle mimicking the propulsion mechanism and physical appearance of a medusa (jellyfish). The robotic jellyfish called Robojelly mimics the morphology and kinematics of the Aurelia aurita species. Robojelly actuates using bio-inspired shape memory alloy composite actuators. A systematic fabrication technique was developed to replicate the essential structural features of A. aurita. Robojelly's body was fabricated from RTV silicone having a total mass of 242 g and bell diameter of 164 mm. Robojelly was able to generate enough thrust in static water conditions to propel itself and achieve a proficiency of 0.19 s{sup -1} while the A. aurita achieves a proficiency of around 0.25 s{sup -1}. A thrust analysis based on empirical measurements for a natural jellyfish was used to compare the performance of the different robotic configurations. The configuration with best performance was a Robojelly with segmented bell and a passive flap structure. Robojelly was found to consume an average power on the order of 17 W with the actuators not having fully reached a thermal steady state.

  19. [Sir Arthur Conan Doyle, Sherlock Holmes and infectious diseases].

    Science.gov (United States)

    Ledermann D, Walter

    2010-10-01

    Besides a pleasant author of best sellers, Sir Arthur Conan Doyle was a medical doctor, writing excellent short stories about the exercise of his profession in England. However, even he mentions The British Medical Journal and The Lancet in the Sherlock Holmes's stories, when in the plot introduces infectious diseases, Conan Doyle ignores important discoveries in the field of tetanus. Anyway, the appearing of infectious diseases in the adventures of the detective are rare: one mention of tetanus, another of leprosy and- the most analyzed in medical literature a case of murder by inoculation of bacteria, probably the agent of melioidosis. Also he makes his hero discovers the toxic actions of a medusa and a transplant of solid organ. Little for a physician and less for an author who also wrote science fiction: it seems that the history of the great medical discoveries at the end of nineteenth century and beginning of the twentieth has passed by his side.., and he just couldn't see it.

  20. POPULATION DYNAMICS OF THREE SCYPHOZOAN JELLYFISH SPECIES DURING SUMMER OF 2011 IN JIAOZHOU BAY%2011年夏季胶州湾三种大型水母的种群动态研究

    Institute of Scientific and Technical Information of China (English)

    王世伟; 张光涛; 孙松; 王彦涛; 赵增霞

    2012-01-01

    2011年8月1日-9月30日,对胶州湾三种大型水母沙海蛰(Nemopilemanomurai)、白色霞水母fCyaneanozakii)、海月水母似ureliaaurita)的种群数量变动及空间分布情况开展了目测调查,同步获得了气象、水温、盐度、叶绿素a、浮游动物丰度、种类组成等数据,调查频率为每周2次。调查期间,海月水母表现出逐渐降低的趋势,沙海蛰与白色霞水母种群均于8月11日达到数量高峰,8月底及9月中旬之后依次衰落,至9月底,三种水母基本消失。三种水母的种群平均丰度变化范围分别为:沙海蛰0—230.8ind/km0;霞水母0—150.2ind/km2;海月水母0—123.4ind/km2。从分布区域来看,海月水母主要位于近岸区,沙海蜇主要分布于湾口和中部深水区,而白色霞水母则在高峰期和次高峰期分别集中于深水区和近岸区。结合往年资料,作者认为,海月水母种群能够在胶州湾内进行自我补充并完成其生活史,而胶州湾沙海蛰与霞水母的种群补充则可能主要依赖于湾外种群。另外,目测方法的准确性可能受到气象条件的影响。%During August 1 to September 30, 2011, the population abundances and distributions of three scyphozoa jellyfish species Nemopelima nomurai, Cyanea nozakii and Aurelia aurita were examined by visual observation twice per week, along with the investigation of the metrological conditions, water temperatures, salinities, chlorophyll a concentra- tions and the zooplankton abundances. All the three jellyfish species showed great variations on both population abundance and distribution. The mean abundances of N. nomurai, C. nozakii, and A. aurita were 0--230.8ind/km2, 0--150.2ind/km2 and 0--123.4ind/km2, respectively. We also discussed the possible reasons of the three jellyfish species population dy- namics and the limitations of visual observation method in estimation of the scyphozoan jellyfish

  1. Revision of sternaspis otto, 1821 (polychaeta, sternaspidae).

    Science.gov (United States)

    Sendall, Kelly; Salazar-Vallejo, Sergio I

    2013-01-01

    , 1944 from abyssal depths around Indonesia, Sternaspis scutata (Ranzani, 1817) from the Mediterranean Sea, Sternaspis spinosa Sluiter, 1882 from Indonesia, and Sternaspis thorsoni sp. n. from the Iranian Gulf. Two genera are newly proposed to incorporate the remaining species: Caulleryaspis and Petersenaspis. Caulleryaspis gen. n. is defined by the presence of falcate introvert hooks, seven abdominal segments, and soft shields with sediment particles firmly adhered on them; it includes two species: Caulleryaspis gudmundssoni sp. n. from Iceland and Caulleryaspis laevis (Caullery, 1944) comb. n. from Indonesia. Petersenaspis gen. n. is defined by the presence of spatulate introvert hooks, eight abdominal segments, and stiff shields with poorly defined ribs but no concentric line; it includes Petersenaspis capillata (Nonato, 1966) from Brazil and Petersenaspis palpallatoci sp. n. from the Philippines. Neotypes are proposed for eight species: Sternaspis thalassemoides, Sternaspis affinis, Sternaspis africana, Sternaspis costata, Sternaspis fossor, Sternaspis maior, Sternaspis scutata and Sternaspis spinosa, to stabilize these species-group names, and a lectotype is designated for Sternaspis laevis which is transferred to Caulleryaspis gen. n. The geographic range of most species appears to be much smaller than previously indicated, and for some species additional material in good condition is needed to clarify their distributions. Keys to genera and to all species are also included.

  2. Revision of Sternaspis Otto, 1821 (Polychaeta, Sternaspidae

    Directory of Open Access Journals (Sweden)

    Kelly Sendall

    2013-04-01

    . spinosa Sluiter, 1882 from Indonesia, and S. thorsoni sp. n. from the Iranian Gulf. Two genera are newly proposed to incorporate the remaining species: Caulleryaspis and Petersenaspis. Caulleryaspis gen. n. is defined by the presence of falcate introvert hooks, seven abdominal segments, and soft shields with sediment particles firmly adhered on them; it includes two species: C. gudmundssoni sp. n. from Iceland and C. laevis (Caullery, 1944 comb. n. from Indonesia. Petersenaspis gen. n. is defined by the presence of spatulate introvert hooks, eight abdominal segments, and stiff shields with poorly defined ribs but no concentric line; it includes P. capillata (Nonato, 1966 from Brazil and P. palpallatoci sp. n. from the Philippines. Neotypes are proposed for eight species: S. thalassemoides, S. affinis, S. africana, S. costata, S. fossor, S. maior, S. scutata and S. spinosa, to stabilize these species-group names, and a lectotype is designated for S. laevis which is transferred to Caulleryaspis gen. n. The geographic range of most species appears to be much smaller than previously indicated, and for some species additional material in good condition is needed to clarify their distributions. Keys to genera and to all species are also included.

  3. АНАТОМИЧЕСКОЕ СТРОЕНИЕ ЛИСТОВОЙ ПЛАСТИНКИ СИБИРСКИХ КОВЫЛЕЙ (POACEAE, STIPA

    Directory of Open Access Journals (Sweden)

    P. D. Gudkova

    2015-04-01

    Full Text Available В статье представлены результаты исследования анатомического строения листовой пластинки 15 видов сибирских ковылей: S. capillata, S. grandis, S. krylovii, S. baicalensis, S. praecapillata, S. consanguinea, S. orientalis, S. lessingiana, S. kirghisorum, S. dasyphylla, S. pennata, S. pulcherrima, S. zalesskii, S. glareosa, S. klemenzii. У исследованных видов были выявлены следующие диагностические признаки: относительная высота и степень выраженности ребер, их форма, количество и тип жилок, степень развития и расположение склеренхимы, количество и тип трихом на адаксиальной поверхности листьев. Несмотря на однородность этих признаков у многих видов в пределах секции, на секционном уровне они проявляют отличительные морфологические закономерности и имеют высокую таксономическую значимость.

  4. Revision of Sternaspis Otto, 1821 (Polychaeta, Sternaspidae)

    Science.gov (United States)

    Sendall, Kelly; Salazar-Vallejo, Sergio I.

    2013-01-01

    Caullery, 1944 from abyssal depths around Indonesia, Sternaspis scutata (Ranzani, 1817) from the Mediterranean Sea, Sternaspis spinosa Sluiter, 1882 from Indonesia, and Sternaspis thorsoni sp. n. from the Iranian Gulf. Two genera are newly proposed to incorporate the remaining species: Caulleryaspis and Petersenaspis. Caulleryaspis gen. n. is defined by the presence of falcate introvert hooks, seven abdominal segments, and soft shields with sediment particles firmly adhered on them; it includes two species: Caulleryaspis gudmundssoni sp. n. from Iceland and Caulleryaspis laevis (Caullery, 1944) comb. n. from Indonesia. Petersenaspis gen. n. is defined by the presence of spatulate introvert hooks, eight abdominal segments, and stiff shields with poorly defined ribs but no concentric line; it includes Petersenaspis capillata (Nonato, 1966) from Brazil and Petersenaspis palpallatoci sp. n. from the Philippines. Neotypes are proposed for eight species: Sternaspis thalassemoides, Sternaspis affinis, Sternaspis africana, Sternaspis costata, Sternaspis fossor, Sternaspis maior, Sternaspis scutata and Sternaspis spinosa, to stabilize these species-group names, and a lectotype is designated for Sternaspis laevis which is transferred to Caulleryaspis gen. n. The geographic range of most species appears to be much smaller than previously indicated, and for some species additional material in good condition is needed to clarify their distributions. Keys to genera and to all species are also included. PMID:23794844

  5. Abstracts of the Annual Meeting of Planetary Geologic Mappers, Tucson, AZ 2007

    Science.gov (United States)

    Gregg, Tracy K.P.; Tanaka, Kenneth L.; Saunders, R. Stephen; Bleamaster, Leslie F.

    2007-01-01

    presented some new element maps, which may be useful for geologic mapping. Dave Williams of Arizona State University reported on the progress of his global Io map and James Dohm (University of Arizona) discussed results of terrestrial remote mapping studies. Thursday afternoon, the mappers were given a tour of the High Resolution Imaging Science Experiment (HiRISE) operations facility and were given some basic information about how the images are obtained, processed, and publicly released. With official GEMS transition completed at lunch on Thursday, incoming GEMS chair Leslie Bleamaster took the reigns of Friday's meeting. Science presentations began with Ken Tanaka discussing 1:20M-scale global and 1:2M-scale polar mapping of Mars. Jim Zimbelman (Smithsonian Institution) described his 1:1M Medusae Fossae map (MC-8 SE), which is nearing completion, and new mapping (MC-16 NW and MC-23 NW) to further evaluate the Medusae Fossae. Brent Garry, also of the Smithsonian Institution, presented work on Ascraeus Mons. Peter Mouginis-Mark (University of Hawai`i) reported progress on his 1:200K and larger maps of Tooting crater and of the Olympus Mons summit caldera. Laszlo Keszthelyi (USGS) presented mapping of Athabasca Valles, with much of the credit going to Windy Jaeger. Jim Skinner (USGS) introduced a new mapping project including nine MTM quadrangles in the Utopia Planitia region. Tracy Gregg finished off the day's science presentations with discussion of Hesperia Planum. After discussion was complete, the group once again traveled to the University of Arizona - this time for a tour of the Mars Phoenix operations center. Principal Investigator Peter Smith beamed as he led mappers through the multi-million dollar facility. A main topic of discussion throughout the entire meeting was that of nomenclature, specifically how to classify the individual depressions at the tops of volcanoes. Paterae, as has been used for Mars, Venus, and Io, was suggested, but i

  6. Metodologias de preparação de amostras de ferrugem para estudos morfológicos de urediniósporos por meio de microscopia eletrônica de varredura Methodologies processed of some rusts fungi by scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    Louise Larissa May-De Mio

    2006-09-01

    Full Text Available Amostras de urediniósporos de ferrugens das espécies Melampsora epitea Thum., Melampsora medusae Thuem., Hemileia vastatrix Berk., Uromyces appendiculatum Pers., Puccinia sorghi Schwein., Tranzschelia discolor Fuckel e Phakopsora euvitis Ono, coletadas dos hospedeiros, chorão (Salix sp., álamo (Populus deltoides Bartr. Ex. Marsh, cafeeiro (Coffea arabica L., feijoeiro (Phaseolus vulgaris L., milho (Zea mays L., pessegueiro (Prunus persicae L. e videira (Vitis vinifera L. respectivamente, foram processadas de 3 formas: a método convencional (fixação em glutaraldeído e tetróxido de ósmio, desidratação em acetona e secagem ao ponto crítico; b método do vapor de ósmio e metalização com ouro; c metalização direta de amostras (utilizado para esporos soltos. A técnica de fratura de amostra congelada em nitrogênio líquido também foi testada para o estudo do interior de pústulas da ferrugem da videira (P. euvitis. As amostras foram visualizadas em microscópio eletrônico de varredura no NAP/MEPA da ESALQ/USP. Procedeu-se à mensuração dos esporos e as imagens obtidas foram capturadas pelo software LeoUserInterface e processadas utilizando-se o programa de computador "Corel Draw". Em todos os métodos analisados obteve-se uma boa preservação da estrutura possibilitando imagens de alta qualidade. No entanto, para esporos livres (mantidos em cápsula de gelatina o método da metalização direta foi mais prático e rápido. Para observação das pústulas em tecido vegetal os dois métodos de processamento de amostras avaliados proporcionaram resultados satisfatórios. A técnica de fratura em nitrogênio líquido também permitiu perfeita visualização do interior das pústulas da ferrugem da videira.Samples from Urediniospores of some rust fungi such as Melampsora epitea, Melampsora medusae, Hemileia vastatrix, Uromyces appendiculatum, Puccinia sorghi, Tranzschelia discolor and Phakopsora euvitis respectively from Salix sp

  7. The effects of inspiratory muscle strengthening on MIP and quality of life of elderly nursing home patients. (Los efectos del beneficio de la fuerza del músculo inspiratorio en la PIM y la calidad de la vida de los pacientes mayores de la clínica de reposo.

    Directory of Open Access Journals (Sweden)

    Silvia Correa Bacelar

    2008-01-01

    Full Text Available AbstractThe objective of this study was to compare the effects of inspiratory muscle strengthening on maximal inspiratory pressure (MIP and on quality of life among elderly nursing home patients. The study population was divided in two groups: experimental group- EG (n=21, 76.48 2.12 years and control group- CG (n=13, 75.69 2.26 years. The World Health Organization Quality of Life Group (WHOQOL-100 questionnaire was used to evaluate the quality of life of the subjects. A Manovacuometer (analogical, with an operational interval of –150 to +150 cmH2O; Critical Med/USA-2002 was used to evaluate MIP. The study protocol consisted of a gradual increase in workload (50%-100%; the sessions lasted 20 minutes and were composed of 7 series of strengthening (2 minutes each with a 1-minute interval between the series, 3 times a week for 10 weeks. Variance analysis of multivariate repeated measurements demonstrated significant differences only for MIP between CG (32,69±17,03 cmH2O versus 23,08±10,71 cmH2O and EG (31,67±11,11 cmH2O versus 55,24±23,26 cmH2O, and the latter was higher than the former (p= 0,00000. Therefore, we concluded that inspiratory muscle strengthening led to an increase in MIP that did not improve quality of life. However, further studies should be done in this population to validate a quality of life questionnaire specific for the elderly.ResumenEl objetivo de este estudio era comparar los efectos del músculo inspiratorio que consolidaban en la presión inspiratoria máxima (PIM y en la calidad de la vida entre pacientes mayores de la clínica de reposo. Dividieron a la población del estudio en dos grupos: grupo experimental EG. (n=21,76.48 2.12 años y grupo de control CG (n=13, 75.69 2.26 años. La calidad de la Organización Mundial de la Salud del cuestionario del grupo de la vida(WHOQOL-100 fue utilizada para evaluar la calidad de la vida de los temas. Un Manovacuometer (analógico, con un intervalo operacional - de 150 a

  8. Un acercamiento al cuento infantil desde la perspectiva de género. Estereotipos en el cuento infantil

    Directory of Open Access Journals (Sweden)

    Nuria Méndez Garita

    2004-12-01

    Full Text Available

    Resumen. ¿Cuáles son los papeles que desempeñan cada una de las mujeres que son parte de la sociedad? ¿Cómo exige un hombre que se comporte una mujer? ¿Habrán cambiado los estereotipos femeninos y masculinos que muy claramente nos presentan los cuentos? ¿Seguimos propiciando como personas los estereotipos? ¿Se está dando la inversión tanto en los cuentos como en nuestras vidas?

    A partir de mito griego de la Medusa, se introduce el tema del género y la literatura, sobre todo en aquella que se reconoce como literatura infantil. Desde la perspectiva de género, se pueden tratar diferentes tópicos, en este caso, el artículo se centra en los estereotipos y confrontan los que se derivan de la mujer ángel y la mujer demonio.

    A lo largo de la historia, la elaboración del mundo simbólico, del significado y del sentido han estado en las mentes de los varones, los que han configurado una representación del mundo a su imagen y semejanza. Son ellos el prototipo, patrón y medida de lo existente.

    En los cuentos infantiles podemos ver claramente los estereotipos impuestos por la cultura patriarcal; pero también, cómo algunos de ellos son capaces de subvertir el orden establecido. Lo más importante es que la lectura de cuentos infantiles y de la literatura en general, sirve para movernos y conmovernos como lectores; para que nos marque, porque nos interpela.

     

    Abstract. What is the role of each woman in society ? What are a man`s demands in regards to a woman`s behavior? Have the feminine and masculine stereotypes clearly presented to us in stories changed? Are we still, as humans, favoring stereotypes? Is inversión still taking place in both, stories and real life? The Greek myth about Medusa introduces the topic of gender and literature, especially in children's literature

  9. 胶州湾海月水母(Aurelia sp.1)丰度周年变化及对浮游动物群落的影响%ANNUAL OCCURRENCE OF MOON JELLYFISH A URELIA sp.1 IN THE JIAOZHOU BAY AND ITS IMPACTS ON ZOOPLANKTON COMMUNITY

    Institute of Scientific and Technical Information of China (English)

    万艾勇; 张光涛

    2012-01-01

    2009年2—12月间在胶州湾大沽河口邻近海域的逐月现场调查中,利用垂直拖网研究了海月水母碟状体和水母体的时空分布情况以及对其它浮游动物类群的影响,并探讨了海月水母的生态适应性。结果表明:海月水母的碟状体4月份开始在胶州湾出现,并且丰度逐渐增加,到6月份达到最高峰。海月水母的水母体集中在7月份大量出现。碟状体和水母体高峰期的月平均丰度分别为2.9和1.3ind/m2。碟状体开始出现时的水温平均为11.5℃,数量高峰期的水温为20.6℃,而水母体高峰期的水温为25.2℃。该海域的浮游动物总丰度(不含夜光虫)在5—7月份有个高峰期,其中5月份最高值为486.9ind/m2。7月份海月水母高峰期,浮游动物的丰度没有明显下降,两者丰度的地理变化之间也没有显著的相关性。但是通过对2006--2010年间的浮游动物各类群丰度对比,2009年海月水母暴发时夜光虫和桡足类春季丰度高值显著低于其它年份。%During February--December, 2009, monthly investigations were carried out in north-western part of the Jiaozhou Bay. Abundances of the moon jellyfish Aurelia aurita and other zooplankton groups were investigated with ver- tical net towing. Ecological adaption and impacts on other zooplankton groups of moon jellyfish were analysed, and com- pared with synchronous zooplankton and environmental data. Ephyra ofA. aurita was observed from April to June, when its abundance increased from 0.1 to 2.9ind/m3. Medusa ofA. aurita was captured only in July with an average abundance of 1.3ind/m3. The average water temperatures were 11.5 ~C at occurrence of ephyra and 20.6 and 25.2~C during abundance peak of ephyra and medusae, respectively. Total zooplankton abundance (without A. aurita and Noctiluca seintillans) was high from May to July, with the highest of 486.9ind/m3 being observed in May. In July, no

  10. Towards a global network of gamma-ray detector calibration facilities

    Science.gov (United States)

    Tijs, Marco; Koomans, Ronald; Limburg, Han

    2016-09-01

    Gamma-ray logging tools are applied worldwide. At various locations, calibration facilities are used to calibrate these gamma-ray logging systems. Several attempts have been made to cross-correlate well known calibration pits, but this cross-correlation does not include calibration facilities in Europe or private company calibration facilities. Our aim is to set-up a framework that gives the possibility to interlink all calibration facilities worldwide by using `tools of opportunity' - tools that have been calibrated in different calibration facilities, whether this usage was on a coordinated basis or by coincidence. To compare the measurement of different tools, it is important to understand the behaviour of the tools in the different calibration pits. Borehole properties, such as diameter, fluid, casing and probe diameter strongly influence the outcome of gamma-ray borehole logging. Logs need to be properly calibrated and compensated for these borehole properties in order to obtain in-situ grades or to do cross-hole correlation. Some tool providers provide tool-specific correction curves for this purpose. Others rely on reference measurements against sources of known radionuclide concentration and geometry. In this article, we present an attempt to set-up a framework for transferring `local' calibrations to be applied `globally'. This framework includes corrections for any geometry and detector size to give absolute concentrations of radionuclides from borehole measurements. This model is used to compare measurements in the calibration pits of Grand Junction, located in the USA; Adelaide (previously known as AMDEL), located in Adelaide Australia; and Stonehenge, located at Medusa Explorations BV in the Netherlands.

  11. X-ray scattering from dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    McSherry, D.J

    2000-09-01

    Dense plasmas were studied by probing them with kilovolt x-rays and measuring those scattered at various angles. The Laser-Produced x-ray source emitted Ti He alpha 4.75 keV x-rays. Two different plasma types were explored. The first was created by laser driven shocks on either side of a sample foil consisting of 2 micron Al layer, sandwiched between two 1 micron CH layers. We have observed a peak in the x-ray scattering cross section, indicating diffraction from the plasma. However, the experimentally inferred plasma density, broadly speaking, did not always agree with the hydrodynamic simulation MEDX (A modified version of MEDUSA). The second plasma type that we studied was created by soft x-ray heating on either side of a sample foil, this time consisting of 1 micron layer of Al, sandwiched between two 0.2 micron CH layers. Two foil targets, each consisting of a 0.1 micron thick Au foil mounted on 1 micron of CH, where placed 4 mm from the sample foil. The soft x-rays where produced by laser irradiating these two foil targets. We found that, 0.5 ns after the peak of the laser heating pulses, the measured cross sections more closely matched those simulated using the Thomas Fermi model than the Inferno model. Later in time, at 2 ns, the plasma is approaching a weakly coupled state. This is the first time x-ray scattering cross sections have been measured from dense plasmas generated by radiatively heating both sides of the sample. Moreover, these are absolute values typically within a factor of two of expectation for early x-ray probe times. (author)

  12. X-ray scattering from dense plasmas

    Science.gov (United States)

    McSherry, Declan Joseph

    Dense plasmas were studied by probing them with kilovolt x-rays and measuring those scattered at various angles. The laser produced x-ray source emitted Ti He alpha 4.75 keV x-rays. Two different plasma types were explored. The first was created by laser driven shocks on either side of a sample foil consisting of 2 micron thickness of Al, sandwiched between two 1 micron CH layers. We have observed a peak in the x-ray scattering cross section, indicating diffraction from the plasma. However, the experimentally inferred plasma density, did not always agree broadly with the hydrodynamic simulation MEDX (A modified version of MEDUSA). The second plasma type that we studied was created by soft x-ray heating on either side of a sample foil, this time consisting of 1 micron thickness of Al, sandwiched between two 0.2 micron CH layers. Two foil targets, each consisting of a 0.1 micron thick Au foil mounted on 1 micron of CH, were placed 4 mm from the sample foil. The soft x-rays were produced by laser irradiating these two foil targets. We found that, 0.5 ns after the peak of the laser heating pulses, that the measured cross sections more closely matched those simulated using the Thomas Fermi model than the Inferno model. Later in time, at 2 ns, the plasma is approaching a weakly coupled state. This is the first time x-ray scattering cross sections have been measured from dense plasmas generated by radiatively heating both sides of the sample. Moreover, these are absolute values typically within a factor of two of expectation for early x-ray probe times.

  13. A Minor Modification of Leading Edge Discriminator Circuitry with a Delay Line for Baseline Restoration of Scintillation Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Izumi, N

    2003-05-27

    Multi-channel neutron time-of-flight detector arrays LaNSA, T-ion, Medusa, and Mandala, have been used for neutron spectroscopy in inertial confinement fusion experiments. These multi-channel neutron detector arrays consist of many identical scintillation detectors (842 {approx} 1024 channel), data acquisition electronics (discriminators, time-to digital converters, and controller). Each detector element is operated in neutron counting mode. Time-of-flight of individual detected neutrons are recorded by time to digital converters. The energy of each detected neutrons is determined from its time-of-flight. The accurate time measurement ({Delta}t {approx} 0.5 ns) and straightforward statistical features of the data obtained with these systems provides good integrity and reliability. The elements detector used in these systems are organic scintillators coupled with photo multiplier tubes. A scintillation detector operated in particle-counting mode requires finite recovery time after each detection event. The recovery time is determined by the time responses of scintillators, photo multiplier tubes, and the dead times of following discriminators and time-to digital converters. The harsh gamma ray background environment of fast ignitor experiments requires detectors that have fast recovery times. In high intensity laser experiments (I > 10{sup 19} W/cm{sup 2}), strong gamma ray bursts are produced by relativistic laser plasma interactions. Prior to the neutron signal, these strong gamma ray bursts hit the detectors and interfere with the detection of following neutron signals. In these situations, the recovery time of the system after preceding gamma ray bursts is determined mainly by the base line shift of the PMT signal (due to slower decay components of scintillators ''after glow''). Discriminators cannot detect following signal pulses until the proceeding burst decays below its threshold voltage. The base line shift caused by the after glow

  14. Local versus Generalized Phenotypes in Two Sympatric Aurelia Species: Understanding Jellyfish Ecology Using Genetics and Morphometrics.

    Science.gov (United States)

    Chiaverano, Luciano M; Bayha, Keith W; Graham, William M

    2016-01-01

    For individuals living in environmentally heterogeneous environments, a key component for adaptation and persistence is the extent of phenotypic differentiation in response to local environmental conditions. In order to determine the extent of environmentally induced morphological variation in a natural population distributed along environmental gradients, it is necessary to account for potential genetic differences contributing to morphological differentiation. In this study, we set out to quantify geographic morphological variation in the moon jellyfish Aurelia exposed at the extremes of a latitudinal environmental gradient in the Gulf of Mexico (GoM). We used morphological data based on 28 characters, and genetic data taken from mitochondrial cytochrome oxidase I (COI) and nuclear internal transcribed spacer 1 (ITS-1). Molecular analyses revealed the presence of two genetically distinct species of Aurelia co-occurring in the GoM: Aurelia sp. 9 and Aurelia c.f. sp. 2, named for its divergence from (for COI) and similarity to (for ITS-1) Aurelia sp. 2 (Brazil). Neither species exhibited significant population genetic structure between the Northern and the Southeastern Gulf of Mexico; however, they differed greatly in the degree of geographic morphological variation. The morphology of Aurelia sp. 9 exhibited ecophenotypic plasticity and varied significantly between locations, while morphology of Aurelia c.f. sp. 2 was geographically invariant (i.e., canalized). The plastic, generalist medusae of Aurelia sp. 9 are likely able to produce environmentally-induced, "optimal" phenotypes that confer high relative fitness in different environments. In contrast, the non-plastic generalist individuals of Aurelia c.f. sp. 2 likely produce environmentally-independent phenotypes that provide the highest fitness across environments. These findings suggest the two Aurelia lineages co-occurring in the GoM were likely exposed to different past environmental conditions (i

  15. Local versus Generalized Phenotypes in Two Sympatric Aurelia Species: Understanding Jellyfish Ecology Using Genetics and Morphometrics.

    Directory of Open Access Journals (Sweden)

    Luciano M Chiaverano

    Full Text Available For individuals living in environmentally heterogeneous environments, a key component for adaptation and persistence is the extent of phenotypic differentiation in response to local environmental conditions. In order to determine the extent of environmentally induced morphological variation in a natural population distributed along environmental gradients, it is necessary to account for potential genetic differences contributing to morphological differentiation. In this study, we set out to quantify geographic morphological variation in the moon jellyfish Aurelia exposed at the extremes of a latitudinal environmental gradient in the Gulf of Mexico (GoM. We used morphological data based on 28 characters, and genetic data taken from mitochondrial cytochrome oxidase I (COI and nuclear internal transcribed spacer 1 (ITS-1. Molecular analyses revealed the presence of two genetically distinct species of Aurelia co-occurring in the GoM: Aurelia sp. 9 and Aurelia c.f. sp. 2, named for its divergence from (for COI and similarity to (for ITS-1 Aurelia sp. 2 (Brazil. Neither species exhibited significant population genetic structure between the Northern and the Southeastern Gulf of Mexico; however, they differed greatly in the degree of geographic morphological variation. The morphology of Aurelia sp. 9 exhibited ecophenotypic plasticity and varied significantly between locations, while morphology of Aurelia c.f. sp. 2 was geographically invariant (i.e., canalized. The plastic, generalist medusae of Aurelia sp. 9 are likely able to produce environmentally-induced, "optimal" phenotypes that confer high relative fitness in different environments. In contrast, the non-plastic generalist individuals of Aurelia c.f. sp. 2 likely produce environmentally-independent phenotypes that provide the highest fitness across environments. These findings suggest the two Aurelia lineages co-occurring in the GoM were likely exposed to different past environmental conditions

  16. Taxonomic composition, abundance and biomass of mesozooplankton in the Zhelin Bay-an estuary with intensive aquaculture

    Institute of Scientific and Technical Information of China (English)

    DONG Qiaoxiang; LIN Xiaoping; HE Xin; KELSO W E; HUANG Changjiang

    2006-01-01

    The Zhelin Bay is an estuary that supports intensive aquaculture in South China. Aside from traditional nutrient inputs derived from waste water and agriculture, the increased intensification of aquaculture has accelerated eutrophication during the past decade, jeopardizing aquacultural production. Annual variations of mesozooplankton in the Zhelin Bay were described, providing baseline data for long-term ecological studies. The taxonomic composition, abundance and biomass of mesozooplankton were studied monthly from July 2001 to July 2002 at 19 stations. Collections yielded 73 taxa, including 60 species of copepods, three species of cladocerans, as well as tunicates, chaetognaths, polychaetes, medusae, ostracods, rotatori, amphipods, planktonic mollusks, pelagic larvae, and planktonic shrimps. The Zhelin Bay was dominated by small mesozooplankton, with 76% of the species smaller than 1.4 mm, and 97% of the individuals smaller than 1.0 mm. Dominant species (Paracalanus crassirostris, Oithona brevicornis,and Penilia avirostris) accounting for 60% of the total abundance were less than 0.6 mm in body length. Species diversity, biomass, and total abundance of mesozooplankton were greater in the samples collected outside the bay than inside the bay. Samples from the outer and eastern boundaries of the bay had greater biomass, diversity, and abundance than those from the inner and western boundaries. Total abundance and biomass had a unimodal annual pattern and were the greatest in August 2001 when water temperature was maximum, and the least in February 2002 when water temperature was minimum. Canonical correspondence analysis (CCA) revealed that temperature, turbidity, nutrients and salinity were the main determinants of spatial and temporal distributions of mesozooplankton in the Zhelin Bay, and six distinct zones were identified across the 19 sampling stations.

  17. Comparative study of Hippo pathway genes in cellular conveyor belts of a ctenophore and a cnidarian

    Directory of Open Access Journals (Sweden)

    Alicia Coste

    2016-02-01

    Full Text Available Abstract Background The Hippo pathway regulates growth rate and organ size in fly and mouse, notably through control of cell proliferation. Molecular interactions at the heart of this pathway are known to have originated in the unicellular ancestry of metazoans. They notably involve a cascade of phosphorylations triggered by the kinase Hippo, with subsequent nuclear to cytoplasmic shift of Yorkie localisation, preventing its binding to the transcription factor Scalloped, thereby silencing proliferation genes. There are few comparative expression data of Hippo pathway genes in non-model animal species and notably none in non-bilaterian phyla. Results All core Hippo pathway genes could be retrieved from the ctenophore Pleurobrachia pileus and the hydrozoan cnidarian Clytia hemisphaerica, with the important exception of Yorkie in ctenophore. Expression study of the Hippo, Salvador and Scalloped genes in tentacle “cellular conveyor belts” of these two organisms revealed striking differences. In P. pileus, their transcripts were detected in areas where undifferentiated progenitors intensely proliferate and where expression of cyclins B and D was also seen. In C. hemisphaerica, these three genes and Yorkie are expressed not only in the proliferating but also in the differentiation zone of the tentacle bulb and in mature tentacle cells. However, using an antibody designed against the C. hemiphaerica Yorkie protein, we show in two distinct cell lineages of the medusa that Yorkie localisation is predominantly nuclear in areas of active cell proliferation and mainly cytoplasmic elsewhere. Conclusions This is the first evidence of nucleocytoplasmic Yorkie shift in association with the arrest of cell proliferation in a cnidarian, strongly evoking the cell division-promoting role of this protein and its inhibition by the activated Hippo pathway in bilaterian models. Our results furthermore highlight important differences in terms of deployment and

  18. Development of a real-time PCR assay (SYBR Green I) for rapid identification and quantification of scyphomedusae Aurelia sp.1 planulae

    Science.gov (United States)

    Wang, Jianyan; Zhen, Yu; Mi, Tiezhu; Yu, Zhigang; Wang, Guoshan

    2015-07-01

    The complicated life cycle of Aurelia spp., comprising benthic asexually-reproducing polyps and sexually-reproducing medusae, makes it hard for researchers to identify and track them, especially for early stage individuals, such as planulae. To solve this problem, we developed a real-time PCR assay (SYBR Green I) to identify planulae in both cultured and natural seawater samples. Species-specific primers targeting Aurelia sp.1 mitochondrial 16S rDNA (mt 16S rDNA) regions were designed. Using a calibration curve constructed with plasmids containing the Aurelia sp.1 mt 16S rDNA fragment and a standard curve for planulae, the absolute number of mt 16S rDNA copies per planula was determined and from that the total number of planulae per sample was estimated. For the field samples, a 100-fold dilution of the sample DNA combined with a final concentration of 0.2 μg/μL BSA in the PCR reaction mixture was used to remove real-time PCR inhibitors. Samples collected in Jiaozhou Bay from July to September 2012 were subsequently analyzed using this assay. Peak Aurelia sp.1 planula abundance occurred in July 2012 at stations near Hongdao Island and Qingdao offshore; abundances were very low in August and September. The real-time PCR assay (SYBR Green I) developed here negates the need for traditional microscopic identification, which is laborious and time-consuming, and can detect and quantify jellyfish planulae in field plankton samples rapidly and specifically.

  19. Ernst Haeckel's ontogenetic recapitulation: irritation and incentive from 1866 to our time.

    Science.gov (United States)

    Sander, Klaus

    2002-11-01

    Ernst Haeckel (1834-1919) must count among the most widely known biologists of his time. His monographs on radiolarian skeletons, sponges and medusae immediately became standard works, owing partly to lavish illustrations that later on culminated in his "Art Forms in Nature", which markedly influenced the "art nouveau" of the early 20th century. Haeckel's main impact, however, came from his numerous popular books that were crucial in transferring Darwin's ideas to continental Europe. Haeckel's main addition was his claim that ontogeny recapitulates phylogeny. It was partly founded on pre-Darwinian observations by J.F. Meckel and K.E. v. Baer who noticed that vertebrate embryos of different species resemble each other more strongly during early ontogenesis than later on. Wishing to illustrate this clearly, Haeckel clandestinely generalized some figures showing early embryos of animals and Man. This "fraud" provided ammunition for his many adversaries, most of whom felt provoked by his antireligious campaigns. The resulting controversies continued well into the 20th century but then subsided. Quite recently, however, they have flared up again, perhaps in connection with progress in molecular embryology that revealed an amazing evolutionary conservation of genes and their cooperation in signal transduction chains. The scientific publications that triggered this flare, and a selection of "Letters to the Editor" in both international science magazines and the German popular press, serve here to show that Haeckel's idea of recapitulation, while having proven its heuristic value, is still causing considerable irritation. This results from the widespread intuition that the marvels of ontogenesis and other biological phenomena must reflect some "intelligent design" rather than Darwinian evolution.

  20. High Abundance of the Epibenthic Trachymedusa Ptychogastria polaris Allman, 1878 (Hydrozoa, Trachylina) in Subpolar Fjords along the West Antarctic Peninsula

    Science.gov (United States)

    Smith, Craig R.; Lindsay, Dhugal J.; Bentlage, Bastian; Youngbluth, Marsh J.

    2017-01-01

    Medusae can be conspicuous and abundant members of seafloor communities in deep-sea benthic boundary layers. The epibenthic trachymedusa, Ptychogastria polaris Allman, 1878 (Hydrozoa: Trachylina: Ptychogastriidae) occurs in the cold, high latitude systems of both the northern and southern hemispheres, with a circumpolar distribution in Arctic and sub-Arctic areas, and disjunct reports of a few individuals from Antarctica. In January-February 2010, during benthic megafaunal photosurveys in three subpolar fjords along the West Antarctic Peninsula (Andvord, Flandres and Barilari Bays), P. polaris was recorded in Antarctic Peninsula waters. The trachymedusa, identified from megacore-collected specimens, was a common component of the epifauna in the sediment floored basins at 436–725 m depths in Andvord and Flandres Bays, reaching densities up to 13 m-2, with mean densities in individual basins ranging from 0.06 to 4.19 m-2. These densities are 2 to 400-fold higher than previously reported for P. polaris in either the Arctic or Antarctic. This trachymedusa had an aggregated distribution, occurring frequently in Andvord Bay, but was often solitary in Flandres Bay, with a distribution not significantly different from random. Epibenthic individuals were similar in size, typically measuring 15–25 mm in bell diameter. A morphologically similar trachymedusa, presumably the same species, was also observed in the water column near the bottom in all three fjords. This benthopelagic form attained abundances of up to 7 m-2 of seafloor; however, most P. polaris (~ 80%), were observed on soft sediments. Our findings indicate that fjords provide a prime habitat for the development of dense populations of P. polaris, potentially resulting from high and varied food inputs to the fjord floors. Because P. polaris resides in the water column and at the seafloor, large P. polaris populations may contribute significantly to pelagic-benthic coupling in the WAP fjord ecosystems. PMID

  1. Modeling the response of top-down control exerted by gelatinous carnivores on the Black Sea pelagic food web

    Science.gov (United States)

    Oguz, Temel; Ducklow, Hugh W.; Purcell, Jennifer E.; Malanotte-Rizzoli, Paola

    2001-03-01

    Recent changes in structure and functioning of the interior Black Sea ecosystem are studied by a series of simulations using a one-dimensional, vertically resolved, coupled physical-biochemical model. The simulations are intended to provide a better understanding of how the pelagic food web structure responds to increasing grazing pressure by gelatinous carnivores (medusae Aurelia aurita and ctenophore Mnemiopsis leidyi) during the past 2 decades. The model is first shown to represent typical eutrophic ecosystem conditions of the late 1970s and early 1980s. This simulation reproduces reasonably well the observed planktonic food web structure at a particular location of the Black Sea for which a year-long data set is available from 1978. Additional simulations are performed to explore the role of the Mnemiopsis-dominated ecosystem in the late 1980s. They are also validated by extended observations from specific years. The results indicate that the population outbreaks of the gelatinous species, either Aurelia or Mnemiopsis, reduce mesozooplankton grazing and lead to increased phytoplankton blooms as observed throughout the 1980s and 1990s in the Black Sea. The peaks of phytoplankton, mesozooplankton, Noctiluca, and gelatinous predator biomass distributions march sequentially as a result of prey-predator interactions. The late winter diatom bloom and a subsequent increase in mesozooplankton stocks are robust features common to all simulations. The autotrophs and heterotrophs, however, have different responses during the rest of the year, depending on the nature of grazing pressure exerted by the gelatinous predators. In the presence of Mnemiopsis, phytoplankton have additional distinct and pronounced bloom episodes during the spring and summer seasons. These events appear with a 2 month time shift in the ecosystem prior to introduction of Mnemiopsis.

  2. Dynamics of the bathyal Benthic Boundary Layer in the northwestern Mediterranean: depth and temporal variations in macrofaunal megafaunal communities and their possible connections within deep-sea trophic webs

    Science.gov (United States)

    Cartes, Joan E.

    1998-01-01

    The distribution patterns of benthopelagic fauna and the macrofauna-megafauna trophic relationships in the Benthic Boundary Layer (BBL) were studied. The study is based on data collected during 6 sampling cruises off the Catalan coast (western Mediterranean) during 1991-1995 at depths ranging from 389-1355 m. Crustaceans were the dominant benthopelagic macrofauna in the BBL level closest to the sea bed (~0-1.5 m above bottom) on the Catalan Sea slope. Copepods and peracarid crustaceans (mysids, amphipods, isopods, and cumaceans) were dominant, whereas euphausiids and natantian decapods, some taxa of gelatinous plankton (siphonophores, medusae, and chaetognaths), and benthopelagic fishes were also well represented groups. Seasonal changes in megafaunal decapod crustaceans abundance seem to be linked to changes in the density and the biological cycle of BBL macrofauna, which constitute an important part of the available food exploited by megafauna. Both the advective and the vertical flow of organic matter in the north-western Mediterranean should simultaneously influence peaks of available food (BBL macrofauna) for bathyal-megafaunal decapods. Recruitment of macrofaunal (suprabenthos and infauna) species at the level of canyons and neighbouring slope zones mainly occurred between late autumn-late winter and would probably be mainly induced by an advective component. However, the macrofaunal sizes consumed by megafaunal decapods are found more abundantly represented in spring and summer populations. In parallel, the vertical fluxes seem to determine maxima in the abundance of planktonic organisms (especially copepods) which also occur in late spring-summer. Size, natatory capability, and energetic value are important factors in the selection of food-resources by megafaunal decapods, which would have a greater availability of food in late spring-summer. This would explain both the seasonal maxima of decapod abundance in summer, and maxima in the catches of some

  3. Questioning the role of phenology shifts and trophic mismatching in a planktonic food web

    Science.gov (United States)

    Atkinson, Angus; Harmer, Rachel A.; Widdicombe, Claire E.; McEvoy, Andrea J.; Smyth, Tim J.; Cummings, Denise G.; Somerfield, Paul J.; Maud, Jacqueline L.; McConville, Kristian

    2015-09-01

    In a warming climate, differential shifts in the seasonal timing of predators and prey have been suggested to lead to trophic "mismatches" that decouple primary, secondary and tertiary production. We tested this hypothesis using a 25-year time-series of weekly sampling at the Plymouth L4 site, comparing 57 plankton taxa spanning 4 trophic levels. During warm years, there was a weak tendency for earlier timings of spring taxa and later timings of autumn taxa. While this is in line with many previous findings, numerous exceptions existed and only a few taxa (e.g. Gyrodinium spp., Pseudocalanus elongatus, and Acartia clausi) showed consistent, strong evidence for temperature-related timing shifts, revealed by all 4 of the timing indices that we used. Also, the calculated offsets in timing (i.e. "mismatches") between predator and prey were no greater in extreme warm or cold years than during more average years. Further, the magnitude of these offsets had no effect on the "success" of the predator, in terms of their annual mean abundance or egg production rates. Instead numerous other factors override, including: inter-annual variability in food quantity, high food baseline levels, turnover rates and prolonged seasonal availability, allowing extended periods of production. Furthermore many taxa, notably meroplankton, increased well before the spring bloom. While theoretically a chronic mismatch, this likely reflects trade-offs for example in predation avoidance. Various gelatinous taxa (Phaeocystis, Noctiluca, ctenophores, appendicularians, medusae) may have reduced these predation constraints, with variable, explosive population outbursts likely responding to improved conditions. The match-mismatch hypothesis may apply for highly seasonal, pulsed systems or specialist feeders, but we suggest that the concept is being over-extended to other marine systems where multiple factors compensate.

  4. A Parallel Processing Algorithm for Remote Sensing Classification

    Science.gov (United States)

    Gualtieri, J. Anthony

    2005-01-01

    A current thread in parallel computation is the use of cluster computers created by networking a few to thousands of commodity general-purpose workstation-level commuters using the Linux operating system. For example on the Medusa cluster at NASA/GSFC, this provides for super computing performance, 130 G(sub flops) (Linpack Benchmark) at moderate cost, $370K. However, to be useful for scientific computing in the area of Earth science, issues of ease of programming, access to existing scientific libraries, and portability of existing code need to be considered. In this paper, I address these issues in the context of tools for rendering earth science remote sensing data into useful products. In particular, I focus on a problem that can be decomposed into a set of independent tasks, which on a serial computer would be performed sequentially, but with a cluster computer can be performed in parallel, giving an obvious speedup. To make the ideas concrete, I consider the problem of classifying hyperspectral imagery where some ground truth is available to train the classifier. In particular I will use the Support Vector Machine (SVM) approach as applied to hyperspectral imagery. The approach will be to introduce notions about parallel computation and then to restrict the development to the SVM problem. Pseudocode (an outline of the computation) will be described and then details specific to the implementation will be given. Then timing results will be reported to show what speedups are possible using parallel computation. The paper will close with a discussion of the results.

  5. Temperature and functional traits influence differences in nitrogen uptake capacity between native and invasive grasses.

    Science.gov (United States)

    Leffler, A Joshua; James, Jeremy J; Monaco, Thomas A

    2013-01-01

    Performance differences between native and exotic invasive plants are often considered static, but invasive grasses may achieve growth advantages in western North America shrublands and steppe under only optimal growing conditions. We examine differences in N uptake and several morphological variables that influence uptake at temperatures between 5 and 25 °C. We contrast two native perennial grasses in western North America: Elymus elymoides and Pseudoroegneria spicata; two invasive annual grasses: Bromus tectorum and Taeniatherum caput-medusae; and one highly selected non-native perennial grass: Agropyron cristatum. The influence of temperature on N uptake is poorly characterized, yet these invasive annual grasses are known to germinate in warm soils in the autumn, and both experience cool soils during the short growing season following snowmelt in the spring. To further explore the influence of temperature on the correlation between morphological variables and N uptake, our data are applied to a previously published path model and one proposed here. Differences in N uptake between native and invasive grasses were small at the lowest temperature, but were large at the highest temperature. At lower temperatures, uptake of N by annuals and perennials was correlated with leaf N and mass. At higher temperatures, uptake by annuals was correlated only with these leaf traits, but uptake by perennials was correlated with these leaf traits as well as root N and mass. Consequently, our results imply that annual grasses face fewer morphological constraints on N uptake than perennial grasses, and annual grasses may gain further advantage in warmer temperature conditions or during more frequent warm periods.

  6. Variability in martian sinuous ridge form: Case study of Aeolis Serpens in the Aeolis Dorsa, Mars, and insight from the Mirackina paleoriver, South Australia

    Science.gov (United States)

    Williams, Rebecca M. E.; Irwin, Rossman P.; Burr, Devon M.; Harrison, Tanya; McClelland, Phillip

    2013-07-01

    In the largest known population of sinuous ridges on Mars, Aeolis Serpens stands out as the longest (˜500 km) feature in Aeolis Dorsa. The formation of this landform, whether from fluvial or glacio-fluvial processes, has been debated in the literature. Here we examine higher-resolution data and use a terrestrial analog (the Mirackina paleoriver, South Australia) to show that both the morphology and contextual evidence for Aeolis Serpens are consistent with development of an inverted fluvial landform from differential erosion of variably cemented deposits. The results of this study demonstrate that the induration mechanism can affect preservation of key characteristics of the paleoriver morphology. For groundwater cemented inverted fluvial landforms, like the Mirackina example, isolated remnants of the paleoriver are preserved because of the temporal and spatial variability of cementation sites. Upon landscape inversion, the result is a landform comprised of aligned mesas and ridges with an undulating longitudinal profile. Recognizing how different induration mechanisms affect preservation of fluvial sediments in denuded regions is relevant to the interpretation of sinuous ridges at other locations on Mars. In particular, double ridge transverse shape may be an instrumental aspect in identifying potential inverted fluvial landforms. There are significant limitations on determining former channel parameters for inverted fluvial landforms that form as a result of variable cementation. Radius of curvature can be accurately determined and an upper-bound constraint for former channel wavelength and width can be made, but it is not possible to reconstruct the paleoslope. Thus, the number of applicable paleohydrologic models is restricted and only first order estimates of flow magnitude can be made. Paleodischarge estimates range between 102 and 103 m3/s for both Aeolis Serpens and the Mirackina paleoriver. Located near the base of the Medusae Fossae Formation (MFF

  7. Efeito do treino dos músculos inspiratórios sobre a pressão inspiratória máxima e a autonomia funcional de idosos asilados

    Directory of Open Access Journals (Sweden)

    Samária Cader

    2007-03-01

    Full Text Available O presente estudo tem como objetivo avaliar o efeito do fortalecimento muscular inspiratório sobre a pressão inspiratória máxima (Pimáx e a autonomia funcional de idosos asilados. A amostra foi constituída de 34 gerontes, divididos em grupo experimental - GE (n=21, 76,48±2,12 anos e grupo controle – GC (n=13, 75,69±2,26 anos. Para avaliação da autonomia funcional, foi utilizado o protocolo de avaliação funcional do GDLAM. A Pimáx foi aferida em aparelho próprio denominado Manovacuômetro (Analógico com intervalo operacional de -150 a +150 cmH2O; Critical Med/USA-2002. O protocolo de intervenção consistiu em carga de trabalho instalada gradualmente (50%-100%; sessões com duração de 20 minutos, com 7 séries de fortalecimento (2 minutos cada e intervalo de 1 minuto entre as séries, durante 10 semanas, 3 vezes na semana. A análise de variância de medidas repetidas multivariada encontrou diferenças significativas entre as variáveis Pimáx, autonomia funcional (IG, caminhar 10m (C10m, levantar da posição sentada (LPS, vestir e tirar a camisa (VTC, levantar da posição decúbito ventral (LPDV e levantar e caminhar por locais da casa (LCLC apresentadas pelos GC e GE, sendo este último superior ao primeiro (p=0,00000. Desta forma, pudesse concluir que o fortalecimento isolado da musculatura inspiratória causou aumento da Pimáx e da autonomia funcional dos idosos asilados analisados.

  8. The ontogenetic scaling of hydrodynamics and swimming performance in jellyfish (Aurelia aurita).

    Science.gov (United States)

    McHenry, Matthew J; Jed, Jason

    2003-11-01

    It is not well understood how ontogenetic changes in the motion and morphology of aquatic animals influence the performance of swimming. The goals of the present study were to understand how changes in size, shape and behavior affect the hydrodynamics of jet propulsion in the jellyfish Aurelia aurita and to explore how such changes affect the ontogenetic scaling of swimming speed and cost of transport. We measured the kinematics of jellyfish swimming from video recordings and simulated the hydrodynamics of swimming with two computational models that calculated thrust generation by paddle and jet mechanisms. Our results suggest that thrust is generated primarily by jetting and that there is negligible thrust generation by paddling. We examined how fluid forces scaled with body mass using the jet model. Despite an ontogenetic increase in the range of motion by the bell diameter and a decrease in the height-to-diameter ratio, we found that thrust and acceleration reaction scaled with body mass as predicted by kinematic similarity. However, jellyfish decreased their pulse frequency with growth, and speed consequently scaled at a lower exponential rate than predicted by kinematic similarity. Model simulations suggest that the allometric growth in Aurelia results in swimming that is slower, but more energetically economical, than isometric growth with a prolate bell shape. The decrease in pulse frequency over ontogeny allows large Aurelia medusae to avoid a high cost of transport but generates slower swimming than if they maintained a high pulse frequency. Our findings suggest that ontogenetic change in the height-to-diameter ratio and pulse frequency of Aurelia results in swimming that is relatively moderate in speed but is energetically economical.

  9. A comparison of the toxinological characteristics of two Cassiopea and Aurelia species.

    Science.gov (United States)

    Radwan, F F; Burnett, J W; Bloom, D A; Coliano, T; Eldefrawi, M E; Erderly, H; Aurelian, L; Torres, M; Heimer-de la Cotera, E P

    2001-01-01

    A comparison of the toxinological properties of nematocyst venoms from Old and New World Cassiopea and Aurelia species was undertaken. The cnidom of venomous Cassiopea andromeda (Ca) and Aurelia (Aa(RS)) from the Red Sea was identical to that of nonvenomous Bahamian Cassiopea xamancha (Cx) and Chesapeake Bay Aurelia aurita (Aa(CB)), respectively. A clean nematocyst preparation of Ca and both Aurelias could be obtained but algal particles could not be separated completely from the Cx nematocysts. Further purification of all four nematocyst preparations showed significant differences in the action of their protein. Only the Cassiopea had coexisting dermonecrotic and vasopermeability producing properties and Ca's hemolytic activity was associated with mouse lethality. The protein, hemolysin and phospholipase gel filtration eluant curves of Ca venom were similar. Venomous Aa(RS) actively stung lips and contained more potent mouse lethal, demonecrotic, vasopermeability plus hemolytic factors than Aa(CB). Cross reactivity of convalescent human serum obtained from patients stung by Ca and venomous Cx collected in Central America occurred. This was also observed between sera of bathers stung by Aa(RS) and stinging Aurelia which appeared in Florida during the recent El Niño year. IgG was stimulated by several nematocyst proteins since many venom subfractions tested positive at high titers against convalescent sera. T-cell proliferation of mice primed with either Aurelia venom was positive against the homologous preparation with cross reactivity to the heterologous venom. Crude venoms of both Red Sea jellyfish metabolically stimulated cultured human hepatocytes more than their New World counterparts. This data shows that considerable similarities and differences exist in the venoms of these Old and New World Cassiopea and Aurelia medusae with the Eastern species being more potent.

  10. Composition of Bacterial Communities Associated with Aurelia aurita Changes with Compartment, Life Stage, and Population.

    Science.gov (United States)

    Weiland-Bräuer, Nancy; Neulinger, Sven C; Pinnow, Nicole; Künzel, Sven; Baines, John F; Schmitz, Ruth A

    2015-09-01

    The scyphozoan Aurelia aurita is recognized as a key player in marine ecosystems and a driver of ecosystem change. It is thus intensely studied to address ecological questions, although its associations with microorganisms remain so far undescribed. In the present study, the microbiota associated with A. aurita was visualized with fluorescence in situ hybridization (FISH) analysis, and community structure was analyzed with respect to different life stages, compartments, and populations of A. aurita by 16S rRNA gene amplicon sequencing. We demonstrate that the composition of the A. aurita microbiota is generally highly distinct from the composition of communities present in ambient water. Comparison of microbial communities from different developmental stages reveals evidence for life stage-specific community patterns. Significant restructuring of the microbiota during strobilation from benthic polyp to planktonic life stages is present, arguing for a restructuring during the course of metamorphosis. Furthermore, the microbiota present in different compartments of the adult medusa (exumbrella mucus and gastric cavity) display significant differences, indicating body part-specific colonization. A novel Mycoplasma strain was identified in both compartment-specific microbiota and is most likely present inside the epithelium as indicated by FISH analysis of polyps, indicating potential endosymbiosis. Finally, comparison of polyps of different populations kept under the same controlled laboratory conditions in the same ambient water showed population-specific community patterns, most likely due the genetic background of the host. In conclusion, the presented data indicate that the associated microbiota of A. aurita may play important functional roles, e.g., during the life cycle. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. High Abundance of the Epibenthic Trachymedusa Ptychogastria polaris Allman, 1878 (Hydrozoa, Trachylina) in Subpolar Fjords along the West Antarctic Peninsula.

    Science.gov (United States)

    Grange, Laura J; Smith, Craig R; Lindsay, Dhugal J; Bentlage, Bastian; Youngbluth, Marsh J

    2017-01-01

    Medusae can be conspicuous and abundant members of seafloor communities in deep-sea benthic boundary layers. The epibenthic trachymedusa, Ptychogastria polaris Allman, 1878 (Hydrozoa: Trachylina: Ptychogastriidae) occurs in the cold, high latitude systems of both the northern and southern hemispheres, with a circumpolar distribution in Arctic and sub-Arctic areas, and disjunct reports of a few individuals from Antarctica. In January-February 2010, during benthic megafaunal photosurveys in three subpolar fjords along the West Antarctic Peninsula (Andvord, Flandres and Barilari Bays), P. polaris was recorded in Antarctic Peninsula waters. The trachymedusa, identified from megacore-collected specimens, was a common component of the epifauna in the sediment floored basins at 436-725 m depths in Andvord and Flandres Bays, reaching densities up to 13 m-2, with mean densities in individual basins ranging from 0.06 to 4.19 m-2. These densities are 2 to 400-fold higher than previously reported for P. polaris in either the Arctic or Antarctic. This trachymedusa had an aggregated distribution, occurring frequently in Andvord Bay, but was often solitary in Flandres Bay, with a distribution not significantly different from random. Epibenthic individuals were similar in size, typically measuring 15-25 mm in bell diameter. A morphologically similar trachymedusa, presumably the same species, was also observed in the water column near the bottom in all three fjords. This benthopelagic form attained abundances of up to 7 m-2 of seafloor; however, most P. polaris (~ 80%), were observed on soft sediments. Our findings indicate that fjords provide a prime habitat for the development of dense populations of P. polaris, potentially resulting from high and varied food inputs to the fjord floors. Because P. polaris resides in the water column and at the seafloor, large P. polaris populations may contribute significantly to pelagic-benthic coupling in the WAP fjord ecosystems.

  12. Phylogenetic relationships of Proboscoida Broch, 1910 (Cnidaria, Hydrozoa): Are traditional morphological diagnostic characters relevant for the delimitation of lineages at the species, genus, and family levels?

    Science.gov (United States)

    Cunha, Amanda F; Collins, Allen G; Marques, Antonio C

    2017-01-01

    Overlapping variation of morphological characters can lead to misinterpretation in taxonomic diagnoses and the delimitation of different lineages. This is the case for hydrozoans that have traditionally been united in the family Campanulariidae, a group known for its wide morphological variation and complicated taxonomic history. In a recently proposed phylogenetic classification of leptothecate hydrozoans, this family was restricted to a more narrow sense while a larger clade containing most species traditionally classified in Campanulariidae, along with members of Bonneviellidae, was established as the suborder Proboscoida. We used molecular data to infer the phylogenetic relationships among campanulariids and assess the traditional classification of the family, as well as the new classification scheme for the group. The congruity and relevance of diagnostic characters were also evaluated. While mostly consistent with the new phylogenetic classification of Proboscoida, our increased taxon sampling resulted in some conflicts at the family level, specially regarding the monophyly of Clytiidae and Obeliidae. Considering the traditional classification, only Obeliidae is close to its original scope (as subfamily Obeliinae). At the genus level, Campanularia and Clytia are not monophyletic. Species with Obelia-like medusae do not form a monophyletic group, nor do species with fixed gonophores, indicating that these characters do not readily diagnose different genera. Finally, the species Orthopyxis integra, Clytia gracilis, and Obelia dichotoma are not monophyletic, suggesting that most of their current diagnostic characters are not informative for their delimitation. Several diagnostic characters in this group need to be reassessed, with emphasis on their variation, in order to have a consistent taxonomic and phylogenetic framework for the classification of campanulariid hydrozoans. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Counter-Memory, Heterochronia, and “History Painting” (After Géricault: Dierk Schmidt’s SIEV-X—On a Case of Intensified Refugee Politics

    Directory of Open Access Journals (Sweden)

    Veronica Tello

    2014-06-01

    Full Text Available This essay examines the disruption of linear time in experimental forms of “history painting” as represented by Dierk Schmidt’s SIEV-X—On a Case of Intensified Refugee Politics (2001-2005. It analyses how the aesthetics of heterochronoia—multiple temporalities—play a crucial role in the development of a new understanding of the politics of “history painting.” As Schmidt’s work reveals, a radical conception of history exists outside the “singular moment,” and in dialogue with heterogenous visual cultures (news media, art history, advertising. In attempting to understand the import of Schmidt’s work, this essay considers his methodologies for creating a heterochronous mode of history painting, particularly his anachronistic engagement with the work of Theodore Géricault and the iconic history painting, The Raft of the Medusa. Unlike previous critical responses to Schmidt’s work, this paper argues that (after Géricault the artist’s use of investigative “journalistic” methodologies for SIEV-X—On a Case of Intensified Refugee Politics do not generate an aesthetics of exposé but rather an aesthetics of “fictionalization.” This aesthetic is defined by the recalibration of documentary and speculative data as a means to reconceive the landscape of the perceptual. The findings of this research demonstrate that the use of disparate fragments—or data—to visualize otherwise diminishing historical events underpins contemporary history painting’s capacity for advancing a distinct economy of affect that circumvents the limitations of the news media and its “monopoly on reality.”

  14. Multiple continental radiations and correlates of diversification in Lupinus (Leguminosae): testing for key innovation with incomplete taxon sampling.

    Science.gov (United States)

    Drummond, Christopher S; Eastwood, Ruth J; Miotto, Silvia T S; Hughes, Colin E

    2012-05-01

    Replicate radiations provide powerful comparative systems to address questions about the interplay between opportunity and innovation in driving episodes of diversification and the factors limiting their subsequent progression. However, such systems have been rarely documented at intercontinental scales. Here, we evaluate the hypothesis of multiple radiations in the genus Lupinus (Leguminosae), which exhibits some of the highest known rates of net diversification in plants. Given that incomplete taxon sampling, background extinction, and lineage-specific variation in diversification rates can confound macroevolutionary inferences regarding the timing and mechanisms of cladogenesis, we used Bayesian relaxed clock phylogenetic analyses as well as MEDUSA and BiSSE birth-death likelihood models of diversification, to evaluate the evolutionary patterns of lineage accumulation in Lupinus. We identified 3 significant shifts to increased rates of net diversification (r) relative to background levels in the genus (r = 0.18-0.48 lineages/myr). The primary shift occurred approximately 4.6 Ma (r = 0.48-1.76) in the montane regions of western North America, followed by a secondary shift approximately 2.7 Ma (r = 0.89-3.33) associated with range expansion and diversification of allopatrically distributed sister clades in the Mexican highlands and Andes. We also recovered evidence for a third independent shift approximately 6.5 Ma at the base of a lower elevation eastern South American grassland and campo rupestre clade (r = 0.36-1.33). Bayesian ancestral state reconstructions and BiSSE likelihood analyses of correlated diversification indicated that increased rates of speciation are strongly associated with the derived evolution of perennial life history and invasion of montane ecosystems. Although we currently lack hard evidence for "replicate adaptive radiations" in the sense of convergent morphological and ecological trajectories among species in different clades, these

  15. Fluorescent proteins function as a prey attractant: experimental evidence from the hydromedusa Olindias formosus and other marine organisms

    Directory of Open Access Journals (Sweden)

    Steven H. D. Haddock

    2015-09-01

    Full Text Available Although proteins in the green fluorescent protein family (GFPs have been discovered in a wide array of taxa, their ecological functions in these organisms remain unclear. Many hypothesized roles are related to modifying bioluminescence spectra or modulating the light regime for algal symbionts, but these do not explain the presence of GFPs in animals that are non-luminous and non-symbiotic. Other hypothesized functions are unrelated to the visual signals themselves, including stress responses and antioxidant roles, but these cannot explain the localization of fluorescence in particular structures on the animals. Here we tested the hypothesis that fluorescence might serve to attract prey. In laboratory experiments, the predator was the hydromedusa Olindias formosus (previously known as O. formosa, which has fluorescent and pigmented patches on the tips of its tentacles. The prey, juvenile rockfishes in the genus Sebastes, were significantly more attracted (P<1×10−5 to the medusa's tentacles under lighting conditions where fluorescence was excited and tentacle tips were visible above the background. The fish did not respond significantly when treatments did not include fluorescent structures or took place under yellow or white lights, which did not generate fluorescence visible above the ambient light. Furthermore, underwater observations of the behavior of fishes when presented with a brightly illuminated point showed a strong attraction to this visual stimulus. In situ observations also provided evidence for fluorescent lures as supernormal stimuli in several other marine animals, including the siphonophore Rhizophysa eysenhardti. Our results support the idea that fluorescent structures can serve as prey attractants, thus providing a potential function for GFPs and other fluorescent proteins in a diverse range of organisms.

  16. LLE 1994 annual report, October 1993--September 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-01-01

    This is the 1994 annual report for the University of Rochester, Laboratory for Laser Energetics. The report is presented as a series of research type reports. The titles emphasize the breadth of work carried out. They are: stability analysis of unsteady ablation fronts; characterization of laser-produced plasma density profiles using grid image refractometry; transport and sound waves in plasmas with light and heavy ions; three-halves-harmonic radiation from long-scale-length plasmas revisited; OMEGA upgrade status report; target imaging and backlighting diagnosis; effect of electron collisions on ion-acoustic waves and heat flow; particle-in-cell code simulations of the interaction of gaussian ultrashort laser pulses with targets of varying initial scale lengths; characterization of thick cryogenic fuel layers: compensation for the lens effect using convergent beam interferometry; compact, multijoule-output, Nd:Glass, large-aperture ring amplifier; atomic force microscopy observation of water-induced morphological changes in Y{sub 2}O{sub 3} monolayer coatings; observation of longitudinal acceleration of electrons born in a high-intensity laser focus; spatial intensity nonuniformities of an OMEGA beam due to nonlinear beam propagation; calculated X-ray backlighting images of mixed imploded targets; evaluation of cosmic rays for use in the monitoring of the MEDUSA scintillator-photomultiplier diagnostic array; highly efficient second-harmonic generation of ultra-intense Nd:Glass laser pulses multiple cutoff wave numbers of the ablative Rayleigh-Taylor instability; ultrafast, all-silicon light modulator; angular dependence of the stimulated Brillouin scattering in homogeneous plasma; femtosecond excited-state dynamics of a conjugated ladder polymer.

  17. Conservation and reintroduction of native orchids of Singapore – the next phase

    Directory of Open Access Journals (Sweden)

    Tim W. Yam

    2012-02-01

    Full Text Available Some 226 species of native orchids have been recorded in Singapore. However, of these 178 are considered to be extinct, and only five are common. The orchid conservation programme aims to monitor existing species, explore ways to conserve their germplasm, and increase their number for subsequent re-introduction into appropriate habitats, including roadside trees, parks and nature areas. From 1999 to 2008, we carried out experiments and have successfully propagated and re-introduced 5 species of native orchids, namely Grammatophyllum speciosum Blume, Bulbophyllum vaginatum Rchb.f., Bulbophyllum membranaceum Teijsm. and Binn., Cymbidium finlaysonianum Lindl. and Cymbidium bicolor Lindl. spp. pubescens (Lindl. Du Puy and Cribb. More than 80% of the plants are growing well and all that have survived have flowered. From 2009 to 2012, we expanded our reintroduction efforts by planting fifteen species: Bulbophyllum blumei (Lindl. J.J.Sm., Bulbophyllum medusae (Lindl. Rchb.f., Bulbophyllum membranaceum Teijsm. and Binn., Bulbophyllum purpurascens (T. and B. J.J.Sm., Bulbophyllum vaginatum Rchb.f., Coelogyne mayeriana Rchb.f., Coelogyne rochussenii De Vr., Cymbidium finlaysonianum Lindl., Dendrobium aloifolium (Blume Rchb.f., Dendrobium leonis (Lindl. Rchb.f., Grammatophyllum speciosum Blume, Phalaenopsis cornu cervi (Breda Bl. and Rchb.f., Cymbidium bicolor Lindl. spp. pubescens (Lindl. Du Puy and Cribb, Thrixspermum amplexicaule Rchb.f., and Vanilla griffithii Rchb.f. is scheduled to be planted. One of our goals is that the reintroduced species would act as catalysts for the restoration of at least part of the original ecosystem. For example, pollinators may be attracted to sites where orchids have been re-introduced. Subsequently, orchid seeds that are produced from naturally pollinated flowers may be blown to the safe sites where appropriate mycorrhizal fungi are present; thus making germination and subsequent establishment of natural populations in

  18. Emergence of protein fold families through rational design.

    Directory of Open Access Journals (Sweden)

    Feng Ding

    2006-07-01

    Full Text Available Diverse proteins with similar structures are grouped into families of homologs and analogs, if their sequence similarity is higher or lower, respectively, than 20%-30%. It was suggested that protein homologs and analogs originate from a common ancestor and diverge in their distinct evolutionary time scales, emerging as a consequence of the physical properties of the protein sequence space. Although a number of studies have determined key signatures of protein family organization, the sequence-structure factors that differentiate the two evolution-related protein families remain unknown. Here, we stipulate that subtle structural changes, which appear due to accumulating mutations in the homologous families, lead to distinct packing of the protein core and, thus, novel compositions of core residues. The latter process leads to the formation of distinct families of homologs. We propose that such differentiation results in the formation of analogous families. To test our postulate, we developed a molecular modeling and design toolkit, Medusa, to computationally design protein sequences that correspond to the same fold family. We find that analogous proteins emerge when a backbone structure deviates only 1-2 angstroms root-mean-square deviation from the original structure. For close homologs, core residues are highly conserved. However, when the overall sequence similarity drops to approximately 25%-30%, the composition of core residues starts to diverge, thereby forming novel families of protein homologs. This direct observation of the formation of protein homologs within a specific fold family supports our hypothesis. The conservation of amino acids in designed sequences recapitulates that of the naturally occurring sequences, thereby validating our computational design methodology.

  19. Control of primary production in the Arctic by nutrients and light: insights from a high resolution ocean general circulation model

    Directory of Open Access Journals (Sweden)

    E. E. Popova

    2010-07-01

    Full Text Available Until recently, the Arctic Basin was generally considered to be a low productivity area and was afforded little attention in global- or even basin-scale ecosystem modelling studies. Due to anthropogenic climate change however, the sea ice cover of the Arctic Ocean is undergoing an unexpectedly fast retreat, exposing increasingly large areas of the basin to sunlight. As indicated by existing Arctic phenomena such as ice-edge blooms, this decline in sea-ice is liable to encourage pronounced growth of phytoplankton in summer and poses pressing questions concerning the future of Arctic ecosystems. It thus provides a strong impetus to modelling of this region.

    The Arctic Ocean is an area where plankton productivity is heavily influenced by physical factors. As these factors are strongly responding to climate change, we analyse here the results from simulations of the 1/4° resolution global ocean NEMO (Nucleus for European Modelling of the Ocean model coupled with the MEDUSA (Model for Ecosystem Dynamics, carbon Utilisation, Sequestration and Acidification biogeochemical model, with a particular focus on the Arctic Basin. Simulated productivity is consistent with the limited observations for the Arctic, with significant production occurring both under the sea-ice and at the thermocline, locations that are difficult to sample in the field.

    Results also indicate that a substantial fraction of the variability in Arctic primary production can be explained by two key physical factors: (i the maximum penetration of winter mixing, which determines the amount of nutrients available for summer primary production, and (ii short-wave radiation at the ocean surface, which controls the magnitude of phytoplankton blooms. A strong empirical correlation was found in the model output between primary production these two factors, highlighting the importance of physical processes in the Arctic Ocean.

  20. Is sleep's 'supreme mystery' unraveling? An evolutionary analysis of sleep encounters no mystery; nor does life's earliest sleep, recently discovered in jellyfish.

    Science.gov (United States)

    Kavanau, J Lee

    2006-01-01

    Biotelemetry has revealed daily 15-h behavioral sleep periods in a cubomedusan jellyfish, Chironex fleckeri. Its sleep is expected to be phylogenetically most primitive, since jellyfish possess only two germ layers. They belong to the phylum Cnidaria, the 'simplest' multicellular organisms with an organized nervous system. Cubomedusae have a complex visual system with 24 eyes of four different types, each type specialized for a different task. Input to these eyes during visually guided fast-swimming predation requires enormous amounts of neural processing, possibly nearly saturating the capacity of their comparatively simple nervous system. These heavy neural demands may account for the need for fifteen hours of sleep. C. fleckeri is the only animal known for which sleep may be either present or absent, dependent on lifestyle. Limited knowledge of behavior of some other cubomedusae suggests that they also possess this faculty. The finding of sleep in C. fleckeri supports current proposals of sleep's origin and basic function. Evolutionary analyses link sleep to a conflict produced by excessive processing demands on multifunctional neural circuitry for detailed focal vision by complex lensed eyes. The conflict arises between the enormous demands of complex visual analysis and needs for split-second control of actions, on the one hand, and non-urgent processing of memories of ongoing and stored events, on the other. Conflict is resolved by deferring the non-urgent processing to periods of sleep. Without sleep, selection would favor the evolution of circuitry 'dedicated' to single or but few tasks, with corresponding lesser efficiency. Had complex lensed eyes of medusae originated as a consequence of selection for increased mating success of males pursuing females, it could have occurred before the evolution of fast-swimming bilateral (three-germ-layered) prey. But if it was a consequence of selection for increased prey-hunting success, the origin of such eyes