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Sample records for fern cave lava

  1. Rock paintings in Fern Cave, Lava Beds National Monument, California: Not the 1054 A.D. (Crab Nebula) Supernova

    Energy Technology Data Exchange (ETDEWEB)

    Armitage, R.A.; Hyman, M.; Rowe, M. W. [Texas A and M Univ., College Station, TX (United States). Dept. of Chemistry; Southon, J. [Lawrence Livermore National Lab., CA (United States). Center for Accelerator Mass Spectrometry; Barat, C. [Lava Beds National Monument, Tule Lake, CA (United States)

    1997-12-31

    On July 4, 1054 A.D. a supernova brighter than Venus appeared in the sky, remaining visible for approximately 23 days and 650 nights. It was chronicled in five independent historic accounts, four in China and one in Japan. For at least 40 years investigators have attributed certain distinctive rock paintings and carvings in the western United States as recordings of the 1054 A.D. supernova. More than twenty such depictions (circle or star-like symbols and a crescent) have been located. Two panels of rock paintings in Lava Beds National Monument, California, one at Fern Cave and one at Symbol Bridge, were listed as recording the 1054 A.D. supernova. The only direct means of assessing the likelihood that a `supernova` representation records the 1054 A.D. event is to date the rock painting or carving. At Texas A and M University, was developed a plasma-chemical extraction technique that permits to analyze the {sup 14}C in rock paintings, whether the pigments used were charcoal or inorganic Fe- and Mn- oxides and hydroxides with organic binder/vehicles. This paper presents direct {sup 14}C age estimates on a rock painting suggested to represent the 1054 A.D. supernova. Charcoal pigment samples were collected from three figures in proximity at Fern Cave: a crescent pointing downward and two nearby circles, one above and one below the crescent. The AMS {sup 14}C analysis on each sample using this technique show that these images do not represent the 1054 A.D. supernova. Paper no. 59; Extended abstract. 1 tab.

  2. Mobile Acoustical Bat Monitoring Annual Summary Report CY 2014 and 2015 - Fern Cave National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These reports summarize bat calls collected along transects at Fern Cave NWR between 2014 and 2015. Calls were classified using Bat Call ID ([BCID] version 2.5a)...

  3. Mobile Acoustical Bat Monitoring Annual Summary Report CY 2012-2013 - Fern Cave National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes bat calls collected along transects at Fern Cave NWR in 2012 and 2013. Calls were classified using Bat Call ID ([BCID] version 2.5a) software...

  4. Mobile Acoustical Bat Monitoring Summary Report 2012 - Fern Cave National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes bat calls collected along transects at Fern Cave NWR in 2012. Calls were classified using EchoClass(v1.1) software, but classification of...

  5. Cave dwelling Onychophora from a Lava Tube in the Galapagos

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    Luis Espinasa

    2015-01-01

    Full Text Available A new population of velvet worms (Onychophora inhabiting a lava tube cave in the island of Santa Cruz, Galapagos, is reported here. The population size is large, suggesting that they may be troglophilic. Its members are darkly pigmented, with no obvious troglomorphic features. Their 16S rRNA sequence showed no differences when compared to an unidentified species of surface velvet worm from the same island, thus supporting cave and surface populations belong to the same species. Based on the 16S rRNA data, the Galapagos velvet worms derived from an Ecuadorian/Colombian clade, as would be expected of ease of dispersal from the nearest mainland to the Galapagos Islands.

  6. The genesis of a lava cave in the Deccan Volcanic Province (Maharashtra, India

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    Nikhil R. Pawar

    2016-01-01

    Full Text Available Lava tubes and channels forming lava distributaries have been recognized from different parts of western Deccan Volcanic Province (DVP. Openings of smaller dimension have been documented from the pāhoehoe flows around Pune, in the western DVP. A small lava cave is exposed in Ghoradeshwar hill, near Pune. Detailed field studies of the physical characteristics, structure and morphology of the flows hosting the lava tube has been carried out. This is the first detailed documentation of a lava cave from the DVP. The lava cave occurs in a compound pāhoehoe flow of Karla Formation, characterized by the presence of lobes, toes and small scale features like squeeze-ups. Field observations and measurements reveal that the dimensions of the cave are small, with low roof and a maximum width of 108 cm. The cave morphology along the 20 m passage varies from circular to semi-circular, with a twilight zone to the north. The gentle micro-topography at Ghoradeshwar controlled the advancement of pāhoehoe lobes and toes within the sheet lobe. The pre-flow gradients towards the north led to the progression of flow from the east, where the cave opening is presently seen. Dimensions and related morphology of the lava cave suggest that it can be best described as a small sub-crustal cave formed by draining of an inflated of pāhoehoe lava lobe. At Ghoradeshwar, besides the natural lava cave, Buddhist caves carved in pāhoehoe lava flows are also observed, indicating that early man took advantage of the existing openings in pāhoehoe flows and sculpted the caves to suit their requirements.

  7. Ferns.

    Science.gov (United States)

    Russell, Helen Ross

    1991-01-01

    Contains several study methods using ferns. Includes exercises on fern propagation, gametophytes and fern hybrids, fern collection, microscope use, asexual reproduction, and fern photography. Background information describes identification techniques and the alternation of generations phenomenon. (MCO)

  8. Wintering bats of the upper Snake River Plain: occurrence in lava-tube caves

    Energy Technology Data Exchange (ETDEWEB)

    Genter, D.L.

    1986-04-30

    Distribution and habitat selection of hibernating bats at the Idaho National Engineering Laboratory (INEL) and adjacent area are reported. Exploration of over 30 lava-tube caves revealed that two species, Myotis leibii and Plecotus townsendii, hibernate in the upper Snake River Plain. Five species, M. lucifugus, M. evotis, Eptesicus fuscus, Lasionycteris noctivagans, and Lasiurus cinereus are considered migratory. Myotis leibii and P. townsendii hibernate throughout much of the area, occasionally in mixed-species groups. Myotis leibii uses the dark and protected regions of the cave, usually wedged into tiny pockets and crevices near or at the highest portion of the ceiling. Individuals of P. townsendii may be found at any height or depth in the cave. Temperature appears to be primary limiting factor in habitat selection. Myotis leibii was found in significantly cooler air temperatures than P. townsendii. Neither species tolerated continuous temperatures below 1.5 C. Relative humidity does not seem to be a significant factor in the distribution or habitat selection of the two species in lava-tube caves. 18 references, 1 figure, 1 table.

  9. Assessing the origin of unusual organic formations in lava caves from Canary Islands (Spain)

    Science.gov (United States)

    Miller, Ana Z.; de la Rosa, Jose M.; Garcia-Sanchez, Angela M.; Pereira, Manuel F. C.; Jurado, Valme; Fernández, Octavio; Knicker, Heike; Saiz-Jimenez, Cesareo

    2016-04-01

    Lava tubes, like other caves, contain a variety of speleothems formed in the initial stage of a lava tube formation or due to leaching and subsequent precipitation of secondary minerals. Primary and secondary mineral formations in lava caves are mainly composed of silicate minerals, although secondary minerals common in limestone caves have been also reported in this type of caves. In addition, unusual colored deposits have been found on the walls and ceilings of lava tubes, some of them of unknown origin and composition. A brown to black-colored mud-like deposits was observed in "Llano de los Caños" Cave, La Palma Island, Canary Islands, Spain. These black deposits coat the wall and ceiling of the lava tube where sub-horizontal fractures occur. FESEM-EDS, X-ray micro-computed tomography and mineralogical analyses were conducted for morphological, 3D microstructural and compositional characterization of these unusual speleothem samples. These techniques revealed that they are mainly composed of amorphous materials, suggesting an organic carbon composition. Hence, analytical pyrolysis (Py-GC/MS), solid-state 13C Nuclear Magnetic Resonance (NMR) and stable isotope analysis were applied to assess the nature and origin of the black deposits. The combination of these analytical tools permits the identification of specific biomarkers (di- and triterpenoids) for tracing the potential sources of the organic compounds in the speleothems. For comparison purposes, samples from the topsoil and overlaying vegetation were also analyzed. Chromatograms resulting from the Py-GC/MS showed an abundance of polysaccharides, lipids and terpenoids typically derived from the vegetation of the area (Erica arborea). In addition, levoglucosan, polycyclic aromatic hydrocarbons and N-containing heterocyclic compounds were detected. They probably derived from the leaching of charred vegetation resulting from a wildfire occurred in the area in 2012. The lack of the typical pattern of odd

  10. Lava cave microbial communities within mats and secondary mineral deposits: implications for life detection on other planets.

    Science.gov (United States)

    Northup, D E; Melim, L A; Spilde, M N; Hathaway, J J M; Garcia, M G; Moya, M; Stone, F D; Boston, P J; Dapkevicius, M L N E; Riquelme, C

    2011-09-01

    Lava caves contain a wealth of yellow, white, pink, tan, and gold-colored microbial mats; but in addition to these clearly biological mats, there are many secondary mineral deposits that are nonbiological in appearance. Secondary mineral deposits examined include an amorphous copper-silicate deposit (Hawai'i) that is blue-green in color and contains reticulated and fuzzy filament morphologies. In the Azores, lava tubes contain iron-oxide formations, a soft ooze-like coating, and pink hexagons on basaltic glass, while gold-colored deposits are found in lava caves in New Mexico and Hawai'i. A combination of scanning electron microscopy (SEM) and molecular techniques was used to analyze these communities. Molecular analyses of the microbial mats and secondary mineral deposits revealed a community that contains 14 phyla of bacteria across three locations: the Azores, New Mexico, and Hawai'i. Similarities exist between bacterial phyla found in microbial mats and secondary minerals, but marked differences also occur, such as the lack of Actinobacteria in two-thirds of the secondary mineral deposits. The discovery that such deposits contain abundant life can help guide our detection of life on extraterrestrial bodies.

  11. Cultivation and complete genome sequencing of Gloeobacter kilaueensis sp. nov., from a lava cave in Kilauea Caldera, Hawai'i.

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    Jimmy H W Saw

    Full Text Available The ancestor of Gloeobacter violaceus PCC 7421(T is believed to have diverged from that of all known cyanobacteria before the evolution of thylakoid membranes and plant plastids. The long and largely independent evolutionary history of G. violaceus presents an organism retaining ancestral features of early oxygenic photoautotrophs, and in whom cyanobacteria evolution can be investigated. No other Gloeobacter species has been described since the genus was established in 1974 (Rippka et al., Arch Microbiol 100:435. Gloeobacter affiliated ribosomal gene sequences have been reported in environmental DNA libraries, but only the type strain's genome has been sequenced. However, we report here the cultivation of a new Gloeobacter species, G. kilaueensis JS1(T, from an epilithic biofilm in a lava cave in Kīlauea Caldera, Hawai'i. The strain's genome was sequenced from an enriched culture resembling a low-complexity metagenomic sample, using 9 kb paired-end 454 pyrosequences and 400 bp paired-end Illumina reads. The JS1(T and G. violaceus PCC 7421(T genomes have little gene synteny despite sharing 2842 orthologous genes; comparing the genomes shows they do not belong to the same species. Our results support establishing a new species to accommodate JS1(T, for which we propose the name Gloeobacter kilaueensis sp. nov. Strain JS1(T has been deposited in the American Type Culture Collection (BAA-2537, the Scottish Marine Institute's Culture Collection of Algae and Protozoa (CCAP 1431/1, and the Belgian Coordinated Collections of Microorganisms (ULC0316. The G. kilaueensis holotype has been deposited in the Algal Collection of the US National Herbarium (US# 217948. The JS1(T genome sequence has been deposited in GenBank under accession number CP003587. The G+C content of the genome is 60.54 mol%. The complete genome sequence of G. kilaueensis JS1(T may further understanding of cyanobacteria evolution, and the shift from anoxygenic to oxygenic photosynthesis.

  12. LAMPENFLORA OF NOVOAFONSKAYA CAVE

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    Mazina S. E.

    2015-11-01

    Full Text Available Novoafonskaya cave is located in Abkhazia. It is equipped for visits in 1975. The cave has permanently installed lighting. In caves with artificial lighting, a vegetation of cyanobacteria and algae, bryophytes and ferns can be found around lamps. The development of lampenflora is a typical problem for cave management. We have identified 69 species of phototrophs in Novoafonskaya cave: Magnoliophyta 2 species, Pteridophyta 6 species, Bryophyta 11 species, Cyanobacteria 34 species, Bacillariophyta 9 species, Ochrophyta 2 species, Chlorophyta 5 species. The article considers main habitat of lampenflora and gives their characteristics. We have also revealed predominance of cyanobacteria in the cave

  13. Cultivation and complete genome sequencing of Gloeobacter kilaueensis sp. nov., from a lava cave in Kīlauea Caldera, Hawai'i.

    Science.gov (United States)

    Saw, Jimmy H W; Schatz, Michael; Brown, Mark V; Kunkel, Dennis D; Foster, Jamie S; Shick, Harry; Christensen, Stephanie; Hou, Shaobin; Wan, Xuehua; Donachie, Stuart P

    2013-01-01

    The ancestor of Gloeobacter violaceus PCC 7421(T) is believed to have diverged from that of all known cyanobacteria before the evolution of thylakoid membranes and plant plastids. The long and largely independent evolutionary history of G. violaceus presents an organism retaining ancestral features of early oxygenic photoautotrophs, and in whom cyanobacteria evolution can be investigated. No other Gloeobacter species has been described since the genus was established in 1974 (Rippka et al., Arch Microbiol 100:435). Gloeobacter affiliated ribosomal gene sequences have been reported in environmental DNA libraries, but only the type strain's genome has been sequenced. However, we report here the cultivation of a new Gloeobacter species, G. kilaueensis JS1(T), from an epilithic biofilm in a lava cave in Kīlauea Caldera, Hawai'i. The strain's genome was sequenced from an enriched culture resembling a low-complexity metagenomic sample, using 9 kb paired-end 454 pyrosequences and 400 bp paired-end Illumina reads. The JS1(T) and G. violaceus PCC 7421(T) genomes have little gene synteny despite sharing 2842 orthologous genes; comparing the genomes shows they do not belong to the same species. Our results support establishing a new species to accommodate JS1(T), for which we propose the name Gloeobacter kilaueensis sp. nov. Strain JS1(T) has been deposited in the American Type Culture Collection (BAA-2537), the Scottish Marine Institute's Culture Collection of Algae and Protozoa (CCAP 1431/1), and the Belgian Coordinated Collections of Microorganisms (ULC0316). The G. kilaueensis holotype has been deposited in the Algal Collection of the US National Herbarium (US# 217948). The JS1(T) genome sequence has been deposited in GenBank under accession number CP003587. The G+C content of the genome is 60.54 mol%. The complete genome sequence of G. kilaueensis JS1(T) may further understanding of cyanobacteria evolution, and the shift from anoxygenic to oxygenic photosynthesis.

  14. Fern Habitats and Rare Ferns in Oklahoma

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    Bruce A. Smith

    2008-12-01

    Full Text Available This paper features some of the more common fern habitats in Oklahoma and provides information on four rare Oklahoma ferns from two fern families: Aspleniaceae and Pteridaceae. Surprisingly, ferns can be found in a variety of habitats across Oklahoma.

  15. Olivine-respiring bacteria isolated from the rock-ice interface in a lava-tube cave, a Mars analog environment.

    Science.gov (United States)

    Popa, Radu; Smith, Amy R; Popa, Rodica; Boone, Jane; Fisk, Martin

    2012-01-01

    The boundary between ice and basalt on Earth is an analogue for some near-surface environments of Mars. We investigated neutrophilic iron-oxidizing microorganisms from the basalt-ice interface in a lava tube from the Oregon Cascades with perennial ice. One of the isolates (Pseudomonas sp. HerB) can use ferrous iron Fe(II) from the igneous mineral olivine as an electron donor and O(2) as an electron acceptor. The optimum growth temperature is ∼12-14°C, but growth also occurs at 5°C. Bicarbonate is a facultative source of carbon. Growth of Pseudomonas sp. HerB as a chemolithotrophic iron oxidizer with olivine as the source of energy is favored in low O(2) conditions (e.g., 1.6% O(2)). Most likely, microbial oxidation of olivine near pH 7 requires low O(2) to offset the abiotic oxidation of iron. The metabolic capabilities of this bacterium would allow it to live in near-surface, icy, volcanic environments of Mars in the present or recent geological past and make this type of physiology a prime candidate in the search for life on Mars.

  16. Comparing flow-through and static ice cave models for Shoshone Ice Cave

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    Kaj E. Williams

    2015-05-01

    Full Text Available In this paper we suggest a new ice cave type: the “flow-through” ice cave. In a flow-through ice cave external winds blow into the cave and wet cave walls chill the incoming air to the wet-bulb temperature, thereby achieving extra cooling of the cave air. We have investigated an ice cave in Idaho, located in a lava tube that is reported to have airflow through porous wet end-walls and could therefore be a flow-through cave. We have instrumented the site and collected data for one year. In order to determine the actual ice cave type present at Shoshone, we have constructed numerical models for static and flow-through caves (dynamic is not relevant here. The models are driven with exterior measurements of air temperature, relative humidity and wind speed. The model output is interior air temperature and relative humidity. We then compare the output of both models to the measured interior air temperatures and relative humidity. While both the flow-through and static cave models are capable of preserving ice year-round (a net zero or positive ice mass balance, both models show very different cave air temperature and relative humidity output. We find the empirical data support a hybrid model of the static and flow-through models: permitting a static ice cave to have incoming air chilled to the wet-bulb temperature fits the data best for the Shoshone Ice Cave.

  17. Minerogenesis of volcanic caves of Kenya.

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    Rossi Antonio

    2003-01-01

    Full Text Available Kenya is one of the few countries in which karst cavities are scarce with respect to volcanic ones, which are widespread throughout the whole country. The great variability in lava composition allowed the evolution of very different cavities, some of which are amongst the largest lava tubes of the world. As normal for such a kind of cave, the hosted speleothems and cave minerals are scarce but important from the minerogenetic point of view. Anyway up to present no specific mineralogical research have been carried out therein. During the 8th International Symposium on Volcanospeleology, held in Nairobi in February 1998, some of the most important volcanic caves of Kenya have been visited and their speleothems and/or chemical deposits sampled: most of them were related to thick guano deposits once present inside these cavities. Speleothems mainly consisted of opal or gypsum, while the deposits related to guano often resulted in a mixture of sulphates and phosphates. The analyses confirmed the great variability in the minerogenetic mechanisms active inside the volcanic caves, which consequently allow the evolution of several different minerals even if the total amount of chemical deposit is scarce. Among the observed minerals kogarkoite, phillipsite and hydroxyapophyllite, must be cited because they are new cave minerals not only for the lava tubes of Kenya, but also for the world cave environment. The achieved results are compared with the available random data from previous literature in order to allow an updated overview on the secondary cave minerals of Kenya.

  18. Between two fern genomes.

    Science.gov (United States)

    Sessa, Emily B; Banks, Jo Ann; Barker, Michael S; Der, Joshua P; Duffy, Aaron M; Graham, Sean W; Hasebe, Mitsuyasu; Langdale, Jane; Li, Fay-Wei; Marchant, D Blaine; Pryer, Kathleen M; Rothfels, Carl J; Roux, Stanley J; Salmi, Mari L; Sigel, Erin M; Soltis, Douglas E; Soltis, Pamela S; Stevenson, Dennis W; Wolf, Paul G

    2014-01-01

    Ferns are the only major lineage of vascular plants not represented by a sequenced nuclear genome. This lack of genome sequence information significantly impedes our ability to understand and reconstruct genome evolution not only in ferns, but across all land plants. Azolla and Ceratopteris are ideal and complementary candidates to be the first ferns to have their nuclear genomes sequenced. They differ dramatically in genome size, life history, and habit, and thus represent the immense diversity of extant ferns. Together, this pair of genomes will facilitate myriad large-scale comparative analyses across ferns and all land plants. Here we review the unique biological characteristics of ferns and describe a number of outstanding questions in plant biology that will benefit from the addition of ferns to the set of taxa with sequenced nuclear genomes. We explain why the fern clade is pivotal for understanding genome evolution across land plants, and we provide a rationale for how knowledge of fern genomes will enable progress in research beyond the ferns themselves.

  19. Between Two Fern Genomes

    OpenAIRE

    Sessa, Emily B.; Banks, Jo; Michael S Barker; Der, Joshua P; Duffy, Aaron M; Graham, Sean W.; Hasebe, Mitsuyasu; Langdale, Jane; Li, Fay-Wei; Marchant, D; Kathleen M. Pryer; Rothfels, Carl J.; Roux, Stanley J.; Salmi, Mari L; Sigel, Erin M.

    2014-01-01

    Ferns are the only major lineage of vascular plants not represented by a sequenced nuclear genome. This lack of genome sequence information significantly impedes our ability to understand and reconstruct genome evolution not only in ferns, but across all land plants. Azolla and Ceratopteris are ideal and complementary candidates to be the first ferns to have their nuclear genomes sequenced. They differ dramatically in genome size, life history, and habit, and thus represent the immense divers...

  20. {sup 14}C AMS dating Yongcheon cave

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.H., E-mail: jefflee@snu.ac.kr [AMS Lab., NCIRF, Seoul National University, Seoul 151-742 (Korea, Republic of); Choe, K. [AMS Lab., NCIRF, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, J.C. [Dept. of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Choi, S.H.; Kang, J.; Song, S.; Song, Y.M. [AMS Lab., NCIRF, Seoul National University, Seoul 151-742 (Korea, Republic of); Jang, J.G. [Jeju National Museum, Jeju 690-782 (Korea, Republic of)

    2013-01-15

    The biggest island in South Korea is Jeju Island, which lies 80 km south of the mainland and has one shield volcano, Mt. Halla. The volcanic island and its lava tubes were added to the world heritage list by UNESCO in 2007. Among the many lava tubes on the island, a unique cave had been accidentally found in 2005 while some workers were replacing a telephone pole. Until the discovery, it had been completely isolated from the outside by naturally-built sand blocks. Yongcheon cave is a lime-decorated lava tube showing both the properties of a volcanic lava tube and a limestone cave. This cave, about 3 km in length, is acknowledged to be the best of this type in the world and includes a large clean-water lake, lava falls, and richly developed speleothems inside it. Even though there is archaeological evidence from well preserved pottery that ancient people entered this place, the preservation of artifacts was ensured by a geological change that made later entrance difficult. We have collected charcoal samples scattered around the cave and dated them using AMS. Ages were in the range of ca. 1570-1260 BP (A.D. 340-880) and this corresponds to the Ancient Three Kingdoms and the Unified Silla era in Korean history. The {sup 14}C AMS measurement results presented in this paper on wood charcoal provide precise dates which will be very useful not only to clarify the nature of human activities in this cave but also to provide reference dates when comparing other dating methods.

  1. Amy Lum Fern

    Science.gov (United States)

    Rossi, Joe

    2007-01-01

    This article presents an interview with Amy Lum Fern, Hawai'i Department of Education teacher from 1933 to 1972. Amy Lum Fern was born in Honolulu in 1909. She received her early education at Central Grammar School and later attended McKinley High School. After graduating from McKinley in 1928, she entered the University of Hawai'i, where she…

  2. Cryopreservation of fern spores

    Science.gov (United States)

    Spore banks for ferns are analogous to seed banks for angiosperms and provide a promising ex situ conservation tool because large quantities of germplasm with high genetic variation can be conserved in a small space with low economic and technical costs. Ferns produce two types of spores with very ...

  3. Conservation of fern spores

    Science.gov (United States)

    Ferns are a diverse and important group of plants, but diversity of species and populations are at risk from increasing social pressures, loss of habitat and climate change. Ex situ conservation is a useful strategy to limit decline in genetic diversity and requires technologies to preserve fern ger...

  4. Bracken fern poisoning

    Science.gov (United States)

    Bracken fern (Pteridium aquilinum) has worldwide distribution and in some areas dominated plant communities replacing desirable forages. Poisoning is identified as enzootic hematuria, bright blindness, and bracken staggers. This chapter reviews updates new information on the plant, the various poi...

  5. Candidate cave entrances on Mars

    Science.gov (United States)

    Cushing, Glen E.

    2012-01-01

    This paper presents newly discovered candidate cave entrances into Martian near-surface lava tubes, volcano-tectonic fracture systems, and pit craters and describes their characteristics and exploration possibilities. These candidates are all collapse features that occur either intermittently along laterally continuous trench-like depressions or in the floors of sheer-walled atypical pit craters. As viewed from orbit, locations of most candidates are visibly consistent with known terrestrial features such as tube-fed lava flows, volcano-tectonic fractures, and pit craters, each of which forms by mechanisms that can produce caves. Although we cannot determine subsurface extents of the Martian features discussed here, some may continue unimpeded for many kilometers if terrestrial examples are indeed analogous. The features presented here were identified in images acquired by the Mars Odyssey's Thermal Emission Imaging System visible-wavelength camera, and by the Mars Reconnaissance Orbiter's Context Camera. Select candidates have since been targeted by the High-Resolution Imaging Science Experiment. Martian caves are promising potential sites for future human habitation and astrobiology investigations; understanding their characteristics is critical for long-term mission planning and for developing the necessary exploration technologies.

  6. Cave Rings

    Science.gov (United States)

    2010-10-13

    hypothesis, that cave rings are formed in the same manner as coffee rings[3], that is, due to the enhanced deposition at the edges of sessile drops ...ring’ is the deposit formed when a sessile drop of a solution containing dissolved particles, such as coffee or salt, dries. This was investigated by...who expanded on Deegan et al.[3] to find an exact form for the evaporation flux over a sessile drop . It turns out that solving 179 for the flux is

  7. Flexible Envelope Request Notation (FERN)

    Science.gov (United States)

    Zoch, David R.; Lavallee, David; Weinstein, Stuart

    1991-01-01

    The following topics are presented in view graph form and include the following: scheduling application; the motivation for the Flexible Envelope Request Notation (FERN); characteristics of FERN; types of information needed in requests; where information is stored in requests; FERN structures; generic requests; resource availability for pooled resources; expressive notation; temporal constraints; time formats; changes to FERN; sample FERN requests; the temporal relationship between two steps; maximum activity length to limit step delays; alternative requests; the temporal relationship between two activities; and idle resource usage between steps.

  8. The omnipresent water fern

    NARCIS (Netherlands)

    Nierop, K.G.J.; Speelman, E.N.; de Leeuw, J.W.; Reichart, G.J.

    2011-01-01

    Several studies have reported the presence of large amounts of lignin in ubiquitously occurring species of the freshwater fern Azolla. Molecular analysis using flash pyrolysis and thermally assisted hydrolysis and methylation shows, however, that neither the leaves nor the roots of Azolla contain li

  9. The omnipresent water fern

    NARCIS (Netherlands)

    Nierop, K.G.J.; Speelman, E.N.; de Leeuw, J.W.; Reichart, G.J.

    2011-01-01

    Several studies have reported the presence of large amounts of lignin in ubiquitously occurring species of the freshwater fern Azolla. Molecular analysis using flash pyrolysis and thermally assisted hydrolysis and methylation shows, however, that neither the leaves nor the roots of Azolla contain

  10. Fern Cave National Wildlife Refuge Land Status Map

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This map was produced by the Division of Realty to depict landownership at Dungeness National Wildlife Refuge in Washington. It was generated from rectified aerial...

  11. Ferns and fern allies of District Shopian, Kashmir Valley, India

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    SHAKOOR A. MIR

    2015-04-01

    Full Text Available Abstract. Mir SA, Mishra AK, Pala SA, Reshi ZA, Sharma MP. Ferns and fern allies of District Shopian, Kashmir Valley, India Biodiversitas 16: 27-43. Shopian, recently created hilly district of Kashmir valley, Jammu and Kashmir is surrounded by the lofty mountains of Pir-Panjal range. More than half area of district is occupied by different forests, subalpine, alpine and mountainous zones. Great altitudinal variation, adequate rainfall, high forest cover, large number of streams, springs and topographic variations render the district worthy for supporting rich fern flora. Therefore, the current study was aimed to undertake in-depth systematic survey of different habitats of Shopian for the collection of diversity of pteridophytes. Specimens were collected during 2010, 2011 and 2012 growing seasons from June to November. A total 81 species of ferns and fern allies belonging 27 genera and 11 families were reported. The dominant families of the region are Dryopteridaceae (25 species followed by Woodsiaceae (16 species, Aspleniaceae (13 species and Pteridaceae (12 species. Similarly, the dominant genera collected from here are Dryopteris (14 species, Asplenium (13, Polystichum (11 species and Athyrium (6 species. A list of the fern and fern allies, along with update nomenclature, their selected Synonym, diagnostic features, distributional and ecological notes have been provided here.

  12. New species of Malaysian ferns

    NARCIS (Netherlands)

    Holttum, R.E.

    1962-01-01

    The present paper includes descriptions of several new species of ferns found among recent collections from various parts of Malaysia; also two new combinations of names of species which are of interest on account of their taxonomic history.

  13. SURVEY OF ORNAMENTAL FERNS, THEIR MORPHOLOGY AND ...

    African Journals Online (AJOL)

    ornamental ferns for environmental management and economic values. Ferns were collected from humid ... purposes, environmental protection, improvement and management in this region. ..... Journal of Current Research 2 (1):. 009-017.

  14. Synaptospory in the fern genus Pyrrosia (Polypodiaceae)

    NARCIS (Netherlands)

    Uffelen, van Gerda A.

    1985-01-01

    The correlation between sporoderm sculpture and life form of the sporophyte as postulated by Kramer (1977) is investigated for the fern genus Pyrrosia. This correlation is not found in Pyrrosia but may be present in other fern groups.

  15. Synaptospory in the fern genus Pyrrosia (Polypodiaceae)

    NARCIS (Netherlands)

    Uffelen, van Gerda A.

    1983-01-01

    The correlation between sporoderm sculpture and life form of the sporophyte as postulated by Kramer (1977) is investigated for the fern genus Pyrrosia. This correlation is not found in Pyrrosia but may be present in other fern groups.

  16. Technologies Enabling Exploration of Skylights, Lava Tubes and Caves Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Missions to date have orbited and roved, but sub-planetary worlds elude exploration. This investigation proposes to develop technology for venturing underground and...

  17. Conjunctival mucus ferning in hypovitaminosis A

    Directory of Open Access Journals (Sweden)

    Edward D

    1988-01-01

    Full Text Available The ocular ferning test was used to qualitatively assess mucus function in early stages of xerophthalmia. The results indicate that inspite of histological evidence of loss of goblet cells in the early stages, mucous function and production is sufficient to produce ferning. It is suggested that such derangements in mucous ferning may occur in more advanced stages of xerophthalmia.

  18. Hollow volcanic tumulus caves of Kilauea Caldera, Hawaii County, Hawaii

    Directory of Open Access Journals (Sweden)

    William R. Halliday

    1998-01-01

    Full Text Available In addition to lava tube caves with commonly noted features, sizable subcrustal spaces of several types exist on the floor of Kilauea Caldera. Most of these are formed by drainage of partially stabilized volcanic structures enlarged or formed by injection of very fluid lava beneath a plastic crust. Most conspicuous are hollow tumuli, possibly first described by Walker in 1991. Walker mapped and described the outer chamber of Tumulus E-I Cave. Further exploration has revealed that it has a hyperthermic inner room beneath an adjoining tumulus with no connection evident on the surface. Two lengthy, sinuous hollow tumuli also are present in this part of the caldera. These findings support Walkers conclusions that hollow tumuli provide valuable insights into tumulus-forming mechanisms, and provide information about the processes of emplacement of pahoehoe sheet flows.

  19. Dunhuang Mogao Caves

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    AS the 20th century approached, a Taoist discovered a cave on the desolate Gobi in Northwest China. Within this cave were hidden more than 40,000 pieces of Buddhist scripture, embroideries, paintings and books on various subjects, such as religion, history,

  20. Nerillidae (Annelida) from the Corona lava tube, Lanzarote, with description of Meganerilla cesari, n. sp

    DEFF Research Database (Denmark)

    Worsaae, Katrine; Martínez, A; Núñez, J

    2009-01-01

    Five species of Nerillidae are previously known from Atlantic cave systems. Another four species of Nerillidae are reported here from the Corona lava tube (Lanzarote, Canary Islands) presenting the first records of Mesonerilla and Meganerilla from anchialine environments. We here describe...... reported. Updated diagnoses are presented for Mesonerilla armoricana, reported here for the first time from the Canary Islands, and Leptonerilla diatomeophaga, the only nerillid previously known from the Corona lava tube. The Corona lava tube holds a large variety of benthic habitats, which may explain...

  1. Hawaii Volcanism: Lava Forms

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Over the last several million years the Hawaiian Islands have been built of successive lava flows. They are the most recent additions in a long line of volcanoes...

  2. Martian Lava Flows

    Science.gov (United States)

    2005-01-01

    19 October 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows lava flows at the southeast base of the giant volcano, Olympus Mons. The flat plain in the south-southeast (bottom/lower right) portion of the image is younger than and cuts off the ends of many of the lava flows that came from the northwest (upper left). Many of the lava flows in this image exhibit channels with levees bounding their margins. As each lava flow was advancing, its outer margins cooled and hardened, forming a channel or tube through which the molten rock continued to advance. Location near: 17.2oN, 129.0oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Winter

  3. Salt ingestion caves.

    Directory of Open Access Journals (Sweden)

    Lundquist Charles A.

    2006-01-01

    Full Text Available Large vertebrate herbivores, when they find a salt-bearing layer of rock, say in a cliff face, can produce sizable voids where, overgenerations, they have removed and consumed salty rock. The cavities formed by this natural animal process constitute a uniqueclass of caves that can be called salt ingestion caves. Several examples of such caves are described in various publications. Anexample in Mississippi U.S.A., Rock House Cave, was visited by the authors in 2000. It seems to have been formed by deer orbison. Perhaps the most spectacular example is Kitum Cave in Kenya. This cave has been excavated to a length over 100 metersby elephants. An ancient example is La Cueva del Milodon in Chile, which is reported to have been excavated by the now extinctmilodon, a giant ground sloth. Still other possible examples can be cited. This class of caves deserves a careful definition. First, thecavity in rock should meet the size and other conventions of the locally accepted definition of a cave. Of course this requirement differsin detail from country to country, particularly in the matter of size. The intent is to respect the local conventions. The characteristicthat human entry is possible is judged to be a crucial property of any recognized cave definition. Second, the cavity should besignificantly the result of vertebrate animal consumption of salt-bearing rock. The defining process is that rock removed to form thecave is carried away in the digestive track of an animal. While sodium salts are expected to be the norm, other salts for which thereis animal hunger are acceptable. Also some other speleogenesis process, such as solution, should not be excluded as long as it issecondary in formation of a cave in question.

  4. Anchialine fauna of the Corona lava tunnel (Lanzarote,Canary Islands): diversity, endemism and distribution

    DEFF Research Database (Denmark)

    Martínez, Alexandro; Palmero, A M; Brito, M C;

    2009-01-01

    A checklist of 77 taxa recorded from the anchialine sections of the Corona lava tube is provided, including information on habitats, faunal distribution within the cave, and main references. Of the nine major groups recorded, Crustacea shows the highest diversity with 31 species and the highest...

  5. New Species of Campodeidae (Diplura) from Mexican caves.

    Science.gov (United States)

    Sendra, Alberto; Palacios, Jose; Garcia, Arturo; Montejo, Maira

    2016-01-01

    Six new taxa of Campodeidae (Diplura) are described in the genera Litocampa, Juxtlacampa, Oncinocampa, and Tachycampa. We also redescribe the interesting species Juxtlacampa juxtlahucensis Wygodzinsky, 1944 from Juxtlahuaca cave in Guerrero, Mexico. All of these taxa are cave-dwelling species with more or less noticeable troglobiomorphic features They inhabit the subterranean ecosystem in six limestone massifs and one lava tube cave in the central states of Mexico. Four of these species are included in the "tachycampoide" group and one species in the "podocampoide" group (sensu Bareth & Conde). Nine species already known in Central and South America of the "tachycampoide" group, in such poorly-sampled regions compared with the eight species in the well-sampled Mediterranean region (Ibero-Sardinia and north Africa), suggest an American origin for this group.

  6. Carroll Cave: a Missouri legend

    Science.gov (United States)

    Carroll Cave is one of the premiere caves of Missouri and the Ozarks region. At over 20 miles of surveyed passage, it is the 2nd longest cave in the state and 33rd longest in the nation. It is also the largest known cave formed in the Ordovician aged (443-485 million years ago) Gasconade Dolomite o...

  7. Gas discharges in fumarolic ice caves of Erebus volcano, Antarctica

    Science.gov (United States)

    Fischer, T. P.; Curtis, A. G.; Kyle, P. R.; Sano, Y.

    2013-12-01

    Fumarolic ice caves and towers on Erebus are the surface expression of flank degassing on the world's southernmost active volcano. The caves are formed by warm gases and steam escaping from small vents on the lava flow floors that melts the overlying ice and snow. Extremophiles in the caves may be analogues for extraterrestrial environments. Over the past four Austral summers, mapping, gas and thermal monitoring conducted under the Erebus Caves Project has provided insights into the ice cave formation processes and the relationships between cave structures, magmatic processes, and weather. Gas samples were collected during the 2012 - 2013 field season in 4 ice caves (Warren, Harry's Dream, Sauna, Haggis Hole) as well as the thermal ground at Tramway Ridge. The vents at all of these sites are characterized by diffuse degassing through loose lava or cracks in the lava flow floor. Vent temperatures ranged from 5 to 17°C in most caves and at Tramway Ridge. In Sauna cave the temperature was 40°C. Gases were sampled by inserting a perforated 1 m long, 5 mm diameter stainless steel tube, into the vents or hot ground. Giggenbach bottles, copper tubes and lead glass bottles were connected in series. The gases were pumped at a slow rate (about 20 ml per minute) using a battery pump for 12-24 hours to flush the system. After flushing samples were collected for later analyses. All samples are dominated by atmospheric components, however, carbon dioxide (0.1 to 1.9%), methane (0.005 to 0.01%), hydrogen (0.002 to 0.07%), and helium (0.0009 to 0.002 %) are above air background. Nitrogen (average 74%) and oxygen (23.5%) are slightly below and above air values, respectively. Helium isotopes show minor input of mantle derived helium-3 with 3He4He ratios ranging from 1.03 to 1.18 RA (where RA is the ratio of air). This represents the first detection of hydrogen and helium in the caves. Methane could be produced by anaerobic respiration of subsurface microbes or hydrothermal

  8. Speleothem (Cave Deposit) Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past temperature, precipitation, and other aspects of climate derived from mineral deposits found in caves. Parameter keywords describe what was measured...

  9. The foaming of lavas

    Science.gov (United States)

    Okeefe, J. A.; Walton, W.

    1976-01-01

    Foaming is of great practical and theoretical significance for volcanic processes on the earth, the moon, and perhaps the meteorite parent bodies. The theory of foams agrees with steelmaking experience to indicate that their presence depends on the existence of solutes in the lavas which reduce the surface tension, and are not saturated. These solutes concentrate at the surface, and are called surfactants. The surfactant responsible for the formation of volcanic ash was not identified; it appears to be related to the oxygen partial pressure above the lava. This fact may explain why lunar and meteoritic melts are not observed to foam. Experimental studies are needed to clarify the process.

  10. Energy expenditure in caving.

    Science.gov (United States)

    Antoni, Giorgia; Marini, Elisabetta; Curreli, Nicoletta; Tuveri, Valerio; Comandini, Ornella; Cabras, Stefano; Gabba, Silvia; Madeddu, Clelia; Crisafulli, Antonio; Rinaldi, Andrea C

    2017-01-01

    The aim of this study was to determine the energy expenditure of a group of cavers of both genders and different ages and experience during a 10 hour subterranean exploration, using portable metabolimeters. The impact of caving activity on body composition and hydration were also assessed through bioelectrical impedance, and nutritional habits of cavers surveyed. During cave activity, measured total energy expenditure (TEE) was in the range 225-287 kcal/h for women-men (MET = 4.1), respectively; subjects had an energy intake from food in the range 1000-1200 kcal, thus inadequate to restore lost calories. Bayesian statistical analysis estimated the effect of predictive variables on TEE, revealing that experienced subjects had a 5% lower TEE than the less skilled ones and that women required a comparatively larger energy expenditure than men to perform the same task. BIVA (bioelectrical impedance vector analysis) showed that subjects were within the range of normal hydration before and after cave activity, but bioelectrical changes indicated a reduction of extracellular water in men, which might result in hypo-osmolal dehydration in the case of prolonged underground exercise. All these facts should be considered when planning cave explorations, preparing training programs for subjects practising caving, and optimizing a diet for cavers. Further, information gathered through this study could be of value to reduce accidents in caves related to increase in fatigue.

  11. Ecological anatomy of ferns fronds

    Directory of Open Access Journals (Sweden)

    Nina M. Derzhavina

    2014-04-01

    Full Text Available Structural types of frond anatomy are distinguished on the basis of investigation of 30 species of homosporous ferns and with regard for literature: hydromorphic, hygromorphic, mesomorphic, subxeromorphic, and subsucculent (cryptic succulent. Following frond traits are of highest adaptive value: their area and thickness, type of mesophyll, dry weight of an area unit – specific superficial density, cellular volume, and number of cells per unit of frond area.

  12. Note on apomixis in ferns

    Directory of Open Access Journals (Sweden)

    J. P. Tilquin

    2014-02-01

    Full Text Available In 1964, two new types of apogamy were described in ferns. The sporangia contain at the starting-point 16 spore mother cells and at the endingpoint 32 diplospores. On the one hand, the meiosis is replaced by a mitosis, on the other hand, the first meiotic division aborts and the restituition nucleus divides mitotically. The author's observations imply that the second process is a variant of the first one.

  13. Bubble-induced cave collapse.

    Directory of Open Access Journals (Sweden)

    Lakshika Girihagama

    Full Text Available Conventional wisdom among cave divers is that submerged caves in aquifers, such as in Florida or the Yucatan, are unstable due to their ever-growing size from limestone dissolution in water. Cave divers occasionally noted partial cave collapses occurring while they were in the cave, attributing this to their unintentional (and frowned upon physical contact with the cave walls or the aforementioned "natural" instability of the cave. Here, we suggest that these cave collapses do not necessarily result from cave instability or contacts with walls, but rather from divers bubbles rising to the ceiling and reducing the buoyancy acting on isolated ceiling rocks. Using familiar theories for the strength of flat and arched (un-cracked beams, we first show that the flat ceiling of a submerged limestone cave can have a horizontal expanse of 63 meters. This is much broader than that of most submerged Florida caves (~ 10 m. Similarly, we show that an arched cave roof can have a still larger expanse of 240 meters, again implying that Florida caves are structurally stable. Using familiar bubble dynamics, fluid dynamics of bubble-induced flows, and accustomed diving practices, we show that a group of 1-3 divers submerged below a loosely connected ceiling rock will quickly trigger it to fall causing a "collapse". We then present a set of qualitative laboratory experiments illustrating such a collapse in a circular laboratory cave (i.e., a cave with a circular cross section, with concave and convex ceilings. In these experiments, a metal ball represented the rock (attached to the cave ceiling with a magnet, and the bubbles were produced using a syringe located at the cave floor.

  14. Winter distribution and use of high elevation caves as foraging sites by the endangered Hawaiian hoary bat, Lasiurus cinereus semotus

    Science.gov (United States)

    Bonaccorso, Frank; Montoya-Aiona, Kristina; Pinzari, Corinna A.; Todd, Christopher M.

    2016-01-01

    We examine altitudinal movements involving unusual use of caves by Hawaiian hoary bats, Lasiurus cinereus semotus, during winter and spring in the Mauna Loa Forest Reserve (MLFR), Hawai‘i Island. Acoustic detection of hoary bat vocalizations, were recorded with regularity outside 13 lava tube cave entrances situated between 2,200 to 3,600 m asl from November 2012 to April 2013. Vocalizations were most numerous in November and December with the number of call events and echolocation pulses decreasing through the following months. Bat activity was positively correlated with air temperature and negatively correlated with wind speed. Visual searches found no evidence of hibernacula nor do Hawaiian hoary bats appear to shelter by day in these caves. Nevertheless, bats fly deep into caves as evidenced by numerous carcasses found in cave interiors. The occurrence of feeding buzzes around cave entrances and visual observations of bats flying in acrobatic fashion in cave interiors point to the use of these spaces as foraging sites. Peridroma moth species (Noctuidae), the only abundant nocturnal, flying insect sheltering in large numbers in rock rubble and on cave walls in the MLFR, apparently serve as the principal prey attracting hoary bats during winter to lava tube caves in the upper MLFR. Caves above 3,000 m on Mauna Loa harbor temperatures suitable for Pseudogymnoascus destructansfungi, the causative agent of White-nose Syndrome that is highly lethal to some species of North American cave-dwelling bats. We discuss the potential for White-nose Syndrome to establish and affect Hawaiian hoary bats.

  15. Lava Tube Collapse Pits

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] We will be looking at collapse pits for the next two weeks. Collapse pits on Mars are formed in several ways. In volcanic areas, channelized lava flows can form roofs which insulate the flowing lava. These features are termed lava tubes on Earth and are common features in basaltic flows. After the lava has drained, parts of the roof of the tube will collapse under its own weight. These collapse pits will only be as deep as the bottom of the original lava tube. Another type of collapse feature associated with volcanic areas arises when very large eruptions completely evacuate the magma chamber beneath the volcano. The weight of the volcano will cause the entire edifice to subside into the void space below it. Structural features including fractures and graben will form during the subsidence. Many times collapse pits will form within the graben. In addition to volcanic collapse pits, Mars has many collapse pits formed when volatiles (such as subsurface ice) are released from the surface layers. As the volatiles leave, the weight of the surrounding rock causes collapse pits to form. These collapse pits are found in the southern hemisphere of Mars. They are likely lava tube collapse pits related to flows from Hadriaca Patera. Image information: VIS instrument. Latitude -36.8, Longitude 89.6 East (270.4 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D

  16. Lava tubes and aquifer vulnerability in the upper Actopan River basin, Veracruz, México

    Science.gov (United States)

    Espinasa-Pereña, R.; Delgado Granados, H.

    2011-12-01

    Rapid infiltration leads to very dry conditions on the surface of some volcanic terrains, with large allogenic streams sometimes sinking underground upon reaching a lava flow. Aquifers in lava flows tend to be heterogeneous and discontinuous, generally unconfined and fissured, and have high transmissivity. Springs associated with basalts may be very large but are typically restricted to lava-flow margins. Concern has been expressed regarding the potential for lava-tube caves to facilitate groundwater contamination similar to that afflicting some karst aquifers (Kempe et al., 2003; Kiernan et al., 2002; Halliday 2003). The upper Actopan River basin is a series of narrow valleys excavated in Tertiary volcanic brechias. Several extensive Holocene basaltic tube-fed lava flows have partially filled these valleys. The youngest and longest flow originates at El Volcancillo, a 780 ybP monogenetic volcano. It is over 50 km long, and was fed through a major master tube, the remains of which form several lava-tube caves (Gassos and Espinasa-Pereña, 2008). Another tube-fed flow initiates at a vent at the bottom of Barranca Huichila and can be followed for 7 km to where it is covered by the Volcancillo flow. The Huichila River is captured by this system of lava tubes and can be followed through several underground sections. In dry weather the stream disappears at a sump in one of these caves, although during hurricanes it overflows the tube, floods the Tengonapa plain, and finally sinks through a series of skylights into the master tube of the Volcancillo flow. Near villages, the cave entrances are used as trash dumps, which are mobilized during floods. These include household garbage, organic materials associated with agriculture and even medical supplies. This is a relatively recent phenomenon, caused by population growth and the building of houses above the lava flows. The water resurges at El Descabezadero, gushing from fractures in the lava above the underlying brechias

  17. Further Experiments with Ferns in Culture: Regeneration.

    Science.gov (United States)

    Sheffield, Elizabeth; Attree, Stephen M.

    1983-01-01

    Ferns in culture provide versatile and easily manipulated material for a wide variety of experiments and observations. Information is provided that supplements earlier reports of the vast experimental potential of these cryptogams and outlines laboratory exercises which reveal the regenerative behavior of fern tissue. (JN)

  18. An Exploration into Fern Genome Space.

    Science.gov (United States)

    Wolf, Paul G; Sessa, Emily B; Marchant, Daniel Blaine; Li, Fay-Wei; Rothfels, Carl J; Sigel, Erin M; Gitzendanner, Matthew A; Visger, Clayton J; Banks, Jo Ann; Soltis, Douglas E; Soltis, Pamela S; Pryer, Kathleen M; Der, Joshua P

    2015-08-26

    Ferns are one of the few remaining major clades of land plants for which a complete genome sequence is lacking. Knowledge of genome space in ferns will enable broad-scale comparative analyses of land plant genes and genomes, provide insights into genome evolution across green plants, and shed light on genetic and genomic features that characterize ferns, such as their high chromosome numbers and large genome sizes. As part of an initial exploration into fern genome space, we used a whole genome shotgun sequencing approach to obtain low-density coverage (∼0.4X to 2X) for six fern species from the Polypodiales (Ceratopteris, Pteridium, Polypodium, Cystopteris), Cyatheales (Plagiogyria), and Gleicheniales (Dipteris). We explore these data to characterize the proportion of the nuclear genome represented by repetitive sequences (including DNA transposons, retrotransposons, ribosomal DNA, and simple repeats) and protein-coding genes, and to extract chloroplast and mitochondrial genome sequences. Such initial sweeps of fern genomes can provide information useful for selecting a promising candidate fern species for whole genome sequencing. We also describe variation of genomic traits across our sample and highlight some differences and similarities in repeat structure between ferns and seed plants.

  19. FERN Ethnomedicinal Plant Database: Exploring Fern Ethnomedicinal Plants Knowledge for Computational Drug Discovery.

    Science.gov (United States)

    Thakar, Sambhaji B; Ghorpade, Pradnya N; Kale, Manisha V; Sonawane, Kailas D

    2015-01-01

    Fern plants are known for their ethnomedicinal applications. Huge amount of fern medicinal plants information is scattered in the form of text. Hence, database development would be an appropriate endeavor to cope with the situation. So by looking at the importance of medicinally useful fern plants, we developed a web based database which contains information about several group of ferns, their medicinal uses, chemical constituents as well as protein/enzyme sequences isolated from different fern plants. Fern ethnomedicinal plant database is an all-embracing, content management web-based database system, used to retrieve collection of factual knowledge related to the ethnomedicinal fern species. Most of the protein/enzyme sequences have been extracted from NCBI Protein sequence database. The fern species, family name, identification, taxonomy ID from NCBI, geographical occurrence, trial for, plant parts used, ethnomedicinal importance, morphological characteristics, collected from various scientific literatures and journals available in the text form. NCBI's BLAST, InterPro, phylogeny, Clustal W web source has also been provided for the future comparative studies. So users can get information related to fern plants and their medicinal applications at one place. This Fern ethnomedicinal plant database includes information of 100 fern medicinal species. This web based database would be an advantageous to derive information specifically for computational drug discovery, botanists or botanical interested persons, pharmacologists, researchers, biochemists, plant biotechnologists, ayurvedic practitioners, doctors/pharmacists, traditional medicinal users, farmers, agricultural students and teachers from universities as well as colleges and finally fern plant lovers. This effort would be useful to provide essential knowledge for the users about the adventitious applications for drug discovery, applications, conservation of fern species around the world and finally to create

  20. Hydrodynamic aspect of caves

    Directory of Open Access Journals (Sweden)

    Franci Gabrovsek

    2008-01-01

    Full Text Available From a hydrological point of view, active caves are a series of connected conduits which drain water through an aquifer. Water tends to choose the easiest way through the system but different geological and morphological barriers act as flow restrictions. The number and characteristics of restrictions depends on the particular speleogenetic environment, which is a function of geological, geomorphological, climatological and hydrological settings. Such a variety and heterogeneity of underground systems has presented a challenge for human understanding for many centuries. Access to many underground passages, theoretical knowledge and recent methods (modeling, water pressure-resistant dataloggers, precise sensors etc. give us the opportunity to get better insight into the hydrodynamic aspect of caves. In our work we tried to approach underground hydrodynamics from both theoretical and practical points of view. We present some theoretical background of open surface and pressurized flow in underground rivers and present results of some possible scenarios. Moreover, two case studies from the Ljubljanica river basin are presented in more detail: the cave system between Planinsko polje and Ljubljansko barje, and the cave system between Bloško polje and Cerkniško polje. The approach and methodology in each case is somewhat different, as the aims were different at the beginning of exploration. However, they both deal with temporal and spatial hydrodynamics of underground waters. In the case of Bloško polje-Cerkniško polje system we also explain the feedback loop between hydrodynamics and Holocene speleogenesis.

  1. A new millipede, Austrotyla awishoshola n. sp., (Diplopoda, Chordeumatida, Conotylidae) from New Mexico, USA, and the importance of cave moss gardens as refugial habitats.

    Science.gov (United States)

    Wynne, J Judson; Shear, William A

    2016-02-25

    Austrotyla awishoshola n. sp. is described from the moss gardens of one lava tube cave in El Malpais National Monument, Cibola Co., New Mexico. Most chordeumatidans require mesic conditions, and these environments are limited to moss gardens in several cave entrances and beneath cave skylights in El Malpais. Presently, this species is known from the moss gardens of a single of cave in the monument. We suggest A. awishoshola may be a climatic relict, having become restricted to the cave environment following the end of the Pleistocene. We discuss the importance of cave moss gardens as refugial and relictual habitats. Recommendations are provided to aid in the conservation and management of A. awishoshola and these habitats.

  2. Sheet flow caves of Kilauea Caldera, Hawaii County, Hawaii

    Directory of Open Access Journals (Sweden)

    William R. Halliday

    1998-01-01

    Full Text Available Terminal lobes of sheet flows of pahoehoe lava sometimes form three-dimensional nests, initially separated by partitions consisting of accreted ‘skins” of each lobe. Melting breaks down these partitions, forming a uniform flow unit. In Kilauea Caldera we have found and mapped sizable drained cavities in low-slope sheet flows. Their general pattern includes three-dimensional nests, with partially melted septa evident in some examples. Christmas Cave is the most extensive found to date, with 632 meters surveyed on two levels. It is located at the lower end of an inflated sheet flow tongue which underwent local deflation as a result of drainage through the cave after its parameters were partially fixed. Small conduit remnants persist in its boundary ridges. The major part of the cave consists of wide, low nestled chambers. Meltdown of such partitions is one of the few emplacement mechanisms of thermal erosion which may not involve any mechanical element. Additional caves in this caldera are being identified and studied.

  3. Genome evolution of ferns: evidence for relative stasis of genome size across the fern phylogeny.

    Science.gov (United States)

    Clark, James; Hidalgo, Oriane; Pellicer, Jaume; Liu, Hongmei; Marquardt, Jeannine; Robert, Yannis; Christenhusz, Maarten; Zhang, Shouzhou; Gibby, Mary; Leitch, Ilia J; Schneider, Harald

    2016-05-01

    The genome evolution of ferns has been considered to be relatively static compared with angiosperms. In this study, we analyse genome size data and chromosome numbers in a phylogenetic framework to explore three hypotheses: the correlation of genome size and chromosome number, the origin of modern ferns from ancestors with high chromosome numbers, and the occurrence of several whole-genome duplications during the evolution of ferns. To achieve this, we generated new genome size data, increasing the percentage of fern species with genome sizes estimated to 2.8% of extant diversity, and ensuring a comprehensive phylogenetic coverage including at least three species from each fern order. Genome size was correlated with chromosome number across all ferns despite some substantial variation in both traits. We observed a trend towards conservation of the amount of DNA per chromosome, although Osmundaceae and Psilotaceae have substantially larger chromosomes. Reconstruction of the ancestral genome traits suggested that the earliest ferns were already characterized by possessing high chromosome numbers and that the earliest divergences in ferns were correlated with substantial karyological changes. Evidence for repeated whole-genome duplications was found across the phylogeny. Fern genomes tend to evolve slowly, albeit genome rearrangements occur in some clades. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  4. Tube coalescence in the Jingfudong lava tube and implications for lava flow hazard of Tengchong volcanism

    OpenAIRE

    Zhengquan Chen; Yongshun Liu; Haiquan Wei; Jiandong Xu; Wenfeng Guo

    2016-01-01

    Tube-fed structure occurs as a general phenomenon in Tengchong basic lavas, such as lava tubes, lava plugs and tube-related collapse depressions. We deduced the development of Laoguipo lava flows, which is the longest lava tube (Jingfudong lava tube) evolved in Tengchong volcanic area. Following the detailed documentation of the tube morphology of the Jingfudong lava tube, we propose that the Jingfudong lava tube was formed through vertical coalescence of at least three tubes. The coalescence...

  5. Fern and bryophyte endozoochory by slugs.

    Science.gov (United States)

    Boch, Steffen; Berlinger, Matthias; Fischer, Markus; Knop, Eva; Nentwig, Wolfgang; Türke, Manfred; Prati, Daniel

    2013-07-01

    Endozoochory plays a prominent role for the dispersal of seed plants, and dispersal vectors are well known. However, for taxa such as ferns and bryophytes, endozoochory has only been suggested anecdotally but never tested in controlled experiments. We fed fertile leaflets of three ferns and capsules of four bryophyte species to three slug species. We found that, overall, spores germinated from slug feces in 57.3% of all 89 fern and in 51.3% of all 117 bryophyte samples, showing that the spores survived gut passage of slugs. Moreover, the number of samples within which spores successfully germinated did not differ among plant species but varied strongly among slug species. This opens new ecological perspectives suggesting that fern and bryophyte endozoochory by gastropods is a so-far-overlooked mode of dispersal, which might increase local population sizes of these taxa by spore deposition on suitable substrates.

  6. Additions to the fern flora of Sulawesi

    NARCIS (Netherlands)

    Hovenkamp, P.H.; Joncheere, de G.J.

    1988-01-01

    A number of additions to the fern flora of Celebes are given here, including also the description of 15 new taxa in the Polypodiaceae, Cyatheaceae, Dennstaedtiaceae, Thelypteridaceae, Aspleniaceae, and Davalliaceae.

  7. Trends and concepts in fern classification

    Science.gov (United States)

    Christenhusz, Maarten J. M.; Chase, Mark W.

    2014-01-01

    Background and Aims Throughout the history of fern classification, familial and generic concepts have been highly labile. Many classifications and evolutionary schemes have been proposed during the last two centuries, reflecting different interpretations of the available evidence. Knowledge of fern structure and life histories has increased through time, providing more evidence on which to base ideas of possible relationships, and classification has changed accordingly. This paper reviews previous classifications of ferns and presents ideas on how to achieve a more stable consensus. Scope An historical overview is provided from the first to the most recent fern classifications, from which conclusions are drawn on past changes and future trends. The problematic concept of family in ferns is discussed, with a particular focus on how this has changed over time. The history of molecular studies and the most recent findings are also presented. Key Results Fern classification generally shows a trend from highly artificial, based on an interpretation of a few extrinsic characters, via natural classifications derived from a multitude of intrinsic characters, towards more evolutionary circumscriptions of groups that do not in general align well with the distribution of these previously used characters. It also shows a progression from a few broad family concepts to systems that recognized many more narrowly and highly controversially circumscribed families; currently, the number of families recognized is stabilizing somewhere between these extremes. Placement of many genera was uncertain until the arrival of molecular phylogenetics, which has rapidly been improving our understanding of fern relationships. As a collective category, the so-called ‘fern allies’ (e.g. Lycopodiales, Psilotaceae, Equisetaceae) were unsurprisingly found to be polyphyletic, and the term should be abandoned. Lycopodiaceae, Selaginellaceae and Isoëtaceae form a clade (the lycopods) that is

  8. Bony anomaly of Meckel's cave.

    Science.gov (United States)

    Tubbs, R Shane; Salter, E George; Oakes, W Jerry

    2006-01-01

    This study describes the seemingly rare occurrence of bone formation within the proximal superior aspect of Meckel's cave thus forming a bony foramen for the proximal trigeminal nerve to traverse. The anatomy of Meckel's cave is reviewed and the clinical potential for nerve compression from this bony anomaly discussed.

  9. Meningiomas of Meckel's cave.

    Science.gov (United States)

    Delfini, R; Innocenzi, G; Ciappetta, P; Domenicucci, M; Cantore, G

    1992-12-01

    A series of 16 patients with meningiomas of Meckel's cave is reported. Trigeminal neuralgia, typical or atypical, was the initial symptom in 10 patients (62.5%). At admission, trigeminal signs and symptoms were present in 15 patients (93.7%); in 7 patients (43.7%), trigeminal dysfunction was combined with the impairment of other cranial nerves. On retrospective analysis, these patients fall into two clinical groups that differ also in prognosis. Group 1 comprises eight patients with trigeminal signs and symptoms only. These patients had small meningiomas strictly affecting Meckel's cave. Total removal of the tumor was achieved in seven of eight patients, without adjunctive postoperative neurological deficits. In this group, there were no tumor recurrences. Group 2 comprises the other eight patients in whom trigeminal dysfunction was combined with impairment of other cranial nerves. These patients had large tumors arising from Meckel's cave and secondarily invading the cavernous sinus (five patients) or extending into the posterior fossa (two patients) or largely growing into the middle fossa (one patient). Total removal was achieved in only one patient, and a worsening of the preoperative neurological status was observed in four patients; there were three cases of tumor progression. A subtemporal intradural approach (used in the past in every case) is still used for the small tumors of Group 1 with good results. Since 1985, for tumors involving the cavernous sinus, we have employed a frontotemporal craniotomy with extradural clinoidectomy and superior and lateral approach to the cavernous sinus. When the tumor extends toward the posterior fossa, we use a combined temporosuboccipital-transpetrosal approach.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. A Mutant Hunt Using the C-Fern (Ceratopteris Richardii)

    Science.gov (United States)

    Calie, Patrick J.

    2005-01-01

    A modification of the popular C-Fern system, the tropical fern Ceratopteris richardii is developed in which students plate out a genetically mixed set of fern spores and then select for specific mutants. This exercise can provide students with an experience in plant mutant selection and can be used as a platform to expose students to a diverse…

  11. Epiphytism in ferns: diversity and history.

    Science.gov (United States)

    Dubuisson, Jean-Yves; Schneider, Harald; Hennequin, Sabine

    2009-01-01

    As for other vascular plants, numerous adaptive strategies have been selected in epiphytic ferns in order to survive in a constraining and desiccating environment and thus to prevent dehydration and/or to access to water and nutrients. Here we present some of the specializations that allow ferns to survive in this particular habitat. Some of the most spectacular epiphytic specializations are observed in the Polypodiaceae family, involving humus-collectors which entrap humus in specialized organs, and ant-plant mutualism strategies. We then address the question of epiphytism in an evolutionary context. There is little fossil evidence of vascular epiphytes. Inferring the evolution of epiphytism in extant ferns shows that diversification of major living epiphytic groups mostly occurred in the Tertiary. Finally, we focus on the Hymenophyllaceae family which provides an original example of hygrophilous epiphytic strategy that is unique in vascular plants.

  12. Fern rhizomes as fodder in Norway

    OpenAIRE

    Alm, Torbjørn

    2016-01-01

    Background Although ferns are often known under collective names in Norway, e.g. blom, a substantial number of vernacular names for individual fern species are known, in particular for useful or poisonous taxa. In the past, the rhizomes (Norwegian: moldfôr) of selected species were collected for fodder. Only scattered records of such use are available from southern Norway, and the tradition’s core area is found in the two North Norwegian counties of Nordland and Troms, in accordance with the ...

  13. Random grid fern for visual tracking

    Science.gov (United States)

    Cheng, Fei; Liu, Kai; Zhang, Jin; Li, YunSong

    2014-05-01

    Visual tracking is one of the significant research directions in computer vision. Although standard random ferns tracking method obtains a good performance for the random spatial arrangement of binary tests, the effect of the locality of image on ferns description ability are ignored and prevent them to describe the object more accurately and robustly. This paper proposes a novel spatial arrangement of binary tests to divide the bounding box into grids in order to keep more details of the image for visual tracking. Experimental results show that this method can improve tracking accuracy effectively.

  14. [Lectins of Dryopteris Adans fern species].

    Science.gov (United States)

    Basheka, O V; Stetsenko, N M; Pogorila, N F

    1999-01-01

    Lectin activity of three ferns species (Dryopteris bushiana Fom., D. laeta (Kom.) C. Chr, D. pseudomas (Wollaston) Holub et Pouzar) has been studied. We used hemagglutination reaction albumin and globulin fractions of fronds and rhizomes extracts with rat erythrocytes. The frond extract of D. pseudomas have shown higher activity as compared with other extracts. The lectin activity of D. laeta leaves was absent. The rhizomes of all three fern species could be characterized as high activity. Based on lectin activity the species were placed as follows order: D. buschiana > D. pseudomas > D. laeta. The dependence with lectin activity and elements (Mn, Fe, Cu, Ni, Zn, Pb, Rb, Sr) content were not found.

  15. Spiders in caves

    Science.gov (United States)

    2017-01-01

    World experts of different disciplines, from molecular biology to macro-ecology, recognize the value of cave ecosystems as ideal ecological and evolutionary laboratories. Among other subterranean taxa, spiders stand out as intriguing model organisms for their ecological role of top predators, their unique adaptations to the hypogean medium and their sensitivity to anthropogenic disturbance. As the description of the first eyeless spider (Stalita taenaria), an array of papers on subterranean spider biology, ecology and evolution has been published, but a comprehensive review on these topics is still lacking. We provide a general overview of the spider families recorded in hypogean habitats worldwide, we review the different adaptations of hypogean spiders to subterranean life, and we summarize the information gathered so far about their origin, population structure, ecology and conservation status. Finally, we point out the limits of the knowledge we currently have regarding hypogean spiders, aiming to stimulate future research. PMID:28446696

  16. Two new fern chloroplasts and decelerated evolution linked to the long generation time in tree ferns.

    Science.gov (United States)

    Zhong, Bojian; Fong, Richard; Collins, Lesley J; McLenachan, Patricia A; Penny, David

    2014-04-30

    We report the chloroplast genomes of a tree fern (Dicksonia squarrosa) and a "fern ally" (Tmesipteris elongata), and show that the phylogeny of early land plants is basically as expected, and the estimates of divergence time are largely unaffected after removing the fastest evolving sites. The tree fern shows the major reduction in the rate of evolution, and there has been a major slowdown in the rate of mutation in both families of tree ferns. We suggest that this is related to a generation time effect; if there is a long time period between generations, then this is probably incompatible with a high mutation rate because otherwise nearly every propagule would probably have several lethal mutations. This effect will be especially strong in organisms that have large numbers of cell divisions between generations. This shows the necessity of going beyond phylogeny and integrating its study with other properties of organisms.

  17. Food uses of ferns in China: a review

    Directory of Open Access Journals (Sweden)

    Yujing Liu

    2012-11-01

    Full Text Available Edible ferns are some of the most important wild vegetables in China. This paper reviews their food uses. The history of eating ferns in China may go back as far as 3000 years. An ethnobotanical inventory of edible ferns was created, with 52 species (including 4 varieties, which were traditionally used. The potential species number of edible ferns was estimated as 144 species (including 4 varieties. The cuisines, products and chemical components of ferns were also summarized. The most commonly eaten fern, Pteridium aquilinum var. latiusculum, was discussed in terms of its toxicity, massive productivity and development strategies. Suggestions and recommendations were proposed for the future development of edible ferns in China.

  18. The evolution of chloroplast genes and genomes in ferns.

    Science.gov (United States)

    Wolf, Paul G; Der, Joshua P; Duffy, Aaron M; Davidson, Jacob B; Grusz, Amanda L; Pryer, Kathleen M

    2011-07-01

    Most of the publicly available data on chloroplast (plastid) genes and genomes come from seed plants, with relatively little information from their sister group, the ferns. Here we describe several broad evolutionary patterns and processes in fern plastid genomes (plastomes), and we include some new plastome sequence data. We review what we know about the evolutionary history of plastome structure across the fern phylogeny and we compare plastome organization and patterns of evolution in ferns to those in seed plants. A large clade of ferns is characterized by a plastome that has been reorganized with respect to the ancestral gene order (a similar order that is ancestral in seed plants). We review the sequence of inversions that gave rise to this organization. We also explore global nucleotide substitution patterns in ferns versus those found in seed plants across plastid genes, and we review the high levels of RNA editing observed in fern plastomes.

  19. A new genus of Lindsaeoid ferns

    NARCIS (Netherlands)

    Kramer, K.U.

    1957-01-01

    In revising the New World representatives of the genus Lindsaea, the author came across a fern specimen from Borneo preserved in the Rijksherbarium, Leiden, that did not seem to fit into any described genus. It had been described as Schizoloma stortii v. A. v. R., but in the author’s opinion the gen

  20. Photosynthesis limitations in three fern species.

    Science.gov (United States)

    Gago, Jorge; Coopman, Rafael E; Cabrera, Hernán Marino; Hermida, Carmen; Molins, Arántzazu; Conesa, Miquel À; Galmés, Jeroni; Ribas-Carbó, Miquel; Flexas, Jaume

    2013-12-01

    Maximum photosynthesis rates in ferns are generally lower than those of seed plants, but little is known about the limiting factors, which are crucial to understand the evolution of photosynthesis in land plants. To address this issue, a gas exchange/chlorophyll fluorescence analysis was performed in three fern species spanning high phylogenetic range within Polypodiopsida (Osmunda regalis, Blechnum gibbum and Nephrolepis exaltata) to determine their maximum net photosynthesis (AN ), stomatal (gs ) and mesophyll (gm ) conductances to CO2 , and the maximum velocity of carboxylation (Vc,max ). The in vitro Rubisco specificity factor (SC /O ) was also determined. All three species had values for SC /O similar to those typical of seed plants, but values of AN , gs , gm and Vc,max were within the lowest range of those observed in seed plants. In addition, gs was unresponsive to light and CO2 , as already described in other fern species. On the contrary, gm varied with changes CO2 . A quantitative photosynthesis limitation analysis suggested that early land plants (ferns) presented not only stomatal limitations-which were less adjustable to the environment-but also restricted gm and Vc,max , resulting in limited maximum photosynthesis rates.

  1. How Fern Creek Is Beating Goliath

    Science.gov (United States)

    Donovan, Margaret; Galatowitsch, Patrick; Hefferin, Keri; Highland, Shanita

    2013-01-01

    The "David" is Fern Creek Elementary, a small urban school in Orlando, Florida, that serves an overwhelmingly disadvantaged student population. The "Goliaths" are the mountains of problems that many inner-city students face--poverty, homelessness, mobility, instability, limited parent involvement, and violent neighborhood…

  2. Newberry Volcano's youngest lava flows

    Science.gov (United States)

    Robinson, Joel E.; Donnelly-Nolan, Julie M.; Jensen, Robert A.

    2015-01-01

    Most of Newberry Volcano's youngest lava flows are found within the Newberry National Volcanic Monument in central Oregon. Established November 5, 1990, the monument is managed by the U.S. Forest Service as part of the Deschutes National Forest. Since 2011, a series of aerial surveys over the monument collected elevation data using lidar (light detection and ranging) technology, which uses lasers to directly measure the ground surface. These data record previously unseen detail in the volcano’s numerous lava flows and vents. On average, a laser return was collected from the ground’s surface every 2.17 feet (ft) with ±1.3 inches vertical precision.

  3. LAVA Pressure Transducer Trade Study

    Science.gov (United States)

    Oltman, Samuel B.

    2016-01-01

    The Regolith and Environment Science and Oxygen and Lunar Volatile Extraction (RESOLVE) payload will transport the (LAVA) subsystem to hydrogen-rich locations on the moon supporting NASA's in-situ resource utilization (ISRU) programs. There, the LAVA subsystem will analyze volatiles that evolve from heated regolith samples in order to quantify how much water is present. To do this, the system needs resilient pressure transducers (PTs) to calculate the moles in the gas samples. The PT trade study includes a comparison of newly-procured models to a baseline unit with prior flight history in order to determine the PT model with the best survivability in flight-forward conditions.

  4. Exploring old caves

    Science.gov (United States)

    Luana Belli, Maria

    2015-04-01

    Quarries, caves and mines often contain fossils. During the '30s in Rome, the urban expansion needs for building materials such as gravel, sand and clay were extracted from quarries that surrounded the city. One of these quarries in particular, in the area of Saccopastore (Nomentana area 3 km from the University Sapienza Roma) returned an ancient human fossil skull belonging to a Neanderthal (most likely a female) who lived in Latium about 120,000 years ago. Detailed studies of this fossil were carried out by Sergio Sergi, the son of the founder of the Museum of Anthropology in Rome, Giuseppe Sergi. The museum was founded in 1884 and was later transferred to the University City (1934) where it is still located. Professor Maria Luana Belli, a science teacher in the Liceo Scientifico "G. Keplero" is a volunteer and collaborator with the Museum "G. Sergi", and she and her students retrace the places of the discovery on the trail of the Neanderthals, for understanding the evolution of the territory in a perspective of interdisciplinary teaching.

  5. Lava Flow at Kilauea, Hawaii

    Science.gov (United States)

    2007-01-01

    On July 21, 2007, the world's most active volcano, Kilauea on Hawaii's Big Island, produced a new fissure eruption from the Pu'u O'o vent, which fed an open lava channel and lava flows toward the east. Access to the Kahauale'a Natural Area Reserve was closed due to fire and gas hazards. The two Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) nighttime thermal infrared images were acquired on August 21 and August 30, 2007. The brightest areas are the hottest lava flows from the recent fissure eruption. The large lava field extending down to the ocean is part of the Kupaianaha field. The most recent activity there ceased on June 20, but the lava is still hot and appears bright on the images. Magenta areas are cold lava flows from eruptions that occurred between 1969 and 2006. Clouds are cold (black) and the ocean is a uniform warm temperature, and light gray in color. These images are being used by volcanologists at the U.S. Geological Survey Hawaii Volcano Observatory to help monitor the progress of the lava flows. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra spacecraft. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties

  6. GEOMORPHIC ANALYSIS OF MAWSMAI CAVE, MEGHALAYA, INDIA

    Directory of Open Access Journals (Sweden)

    Vibhash Chandra Jha

    2011-12-01

    Full Text Available ABSTRACT Caving is an art which can be best experienced in the mystic Mawsmai Cave of Meghalaya. This Cave is fast becoming a hot tourist’s destination offering great adventurous opportunity to the tourists. The cave is located in the East Khasi Hill region near Cherrapunjee and is made of limestone. The emotion of thrill heightens after entering the cave. The entrance has a narrow vertical opening and is well lit. Due to its location in the world’s largest rainfall region, dripping of water from the cave roofs occurs almost throughout the year. The formation of stalactites and stalagmites create wonderful phenomena specially found in this caves. The conspicuous pillars formed due to the joining of the roof and the floors are an awe-inspiring creativity of the creator of this world. Keywords: Cave, Limestone, Stalactite, Stalagmite, Pillar, Solution.

  7. The future of the CAVE

    Science.gov (United States)

    DeFanti, Thomas; Acevedo, Daniel; Ainsworth, Richard; Brown, Maxine; Cutchin, Steven; Dawe, Gregory; Doerr, Kai-Uwe; Johnson, Andrew; Knox, Chris; Kooima, Robert; Kuester, Falko; Leigh, Jason; Long, Lance; Otto, Peter; Petrovic, Vid; Ponto, Kevin; Prudhomme, Andrew; Rao, Ramesh; Renambot, Luc; Sandin, Daniel; Schulze, Jurgen; Smarr, Larry; Srinivasan, Madhu; Weber, Philip; Wickham, Gregory

    2011-03-01

    The CAVE, a walk-in virtual reality environment typically consisting of 4-6 3 m-by-3 m sides of a room made of rear-projected screens, was first conceived and built in 1991. In the nearly two decades since its conception, the supporting technology has improved so that current CAVEs are much brighter, at much higher resolution, and have dramatically improved graphics performance. However, rear-projection-based CAVEs typically must be housed in a 10 m-by-10 m-by-10 m room (allowing space behind the screen walls for the projectors), which limits their deployment to large spaces. The CAVE of the future will be made of tessellated panel displays, eliminating the projection distance, but the implementation of such displays is challenging. Early multi-tile, panel-based, virtual-reality displays have been designed, prototyped, and built for the King Abdullah University of Science and Technology (KAUST) in Saudi Arabia by researchers at the University of California, San Diego, and the University of Illinois at Chicago. New means of image generation and control are considered key contributions to the future viability of the CAVE as a virtual-reality device.

  8. The future of the CAVE

    KAUST Repository

    DeFanti, Thomas

    2011-01-01

    The CAVE, a walk-in virtual reality environment typically consisting of 4–6 3 m-by-3 m sides of a room made of rear-projected screens, was first conceived and built in 1991. In the nearly two decades since its conception, the supporting technology has improved so that current CAVEs are much brighter, at much higher resolution, and have dramatically improved graphics performance. However, rear-projection-based CAVEs typically must be housed in a 10 m-by-10 m-by-10 m room (allowing space behind the screen walls for the projectors), which limits their deployment to large spaces. The CAVE of the future will be made of tessellated panel displays, eliminating the projection distance, but the implementation of such displays is challenging. Early multi-tile, panel-based, virtual-reality displays have been designed, prototyped, and built for the King Abdullah University of Science and Technology (KAUST) in Saudi Arabia by researchers at the University of California, San Diego, and the University of Illinois at Chicago. New means of image generation and control are considered key contributions to the future viability of the CAVE as a virtual-reality device.

  9. The photosynthetic capacity in 35 ferns and fern allies: mesophyll CO2 diffusion as a key trait.

    Science.gov (United States)

    Tosens, Tiina; Nishida, Keisuke; Gago, Jorge; Coopman, Rafael Eduardo; Cabrera, Hernán Marino; Carriquí, Marc; Laanisto, Lauri; Morales, Loreto; Nadal, Miquel; Rojas, Roke; Talts, Eero; Tomas, Magdalena; Hanba, Yuko; Niinemets, Ülo; Flexas, Jaume

    2016-03-01

    Ferns and fern allies have low photosynthetic rates compared with seed plants. Their photosynthesis is thought to be limited principally by physical CO2 diffusion from the atmosphere to chloroplasts. The aim of this study was to understand the reasons for low photosynthesis in species of ferns and fern allies (Lycopodiopsida and Polypodiopsida). We performed a comprehensive assessment of the foliar gas-exchange and mesophyll structural traits involved in photosynthetic function for 35 species of ferns and fern allies. Additionally, the leaf economics spectrum (the interrelationships between photosynthetic capacity and leaf/frond traits such as leaf dry mass per unit area or nitrogen content) was tested. Low mesophyll conductance to CO2 was the main cause for low photosynthesis in ferns and fern allies, which, in turn, was associated with thick cell walls and reduced chloroplast distribution towards intercellular mesophyll air spaces. Generally, the leaf economics spectrum in ferns follows a trend similar to that in seed plants. Nevertheless, ferns and allies had less nitrogen per unit DW than seed plants (i.e. the same slope but a different intercept) and lower photosynthesis rates per leaf mass area and per unit of nitrogen.

  10. Summit firn caves, mount rainier, washington.

    Science.gov (United States)

    Kiver, E P; Mumma, M D

    1971-07-23

    Heat and steam from the crater fumaroles have melted over 5700 feet (1737 meters) of cave passage in the ice-filled east crater of Mount Rainier. The caves are in approximate balance with the present geothermal heat release. Future changes in the thermal activity of the summit cone will cause corresponding changes in cave passage dimensions, location, and ceiling and wall ablation features.

  11. Fern Gametophytes in Culture--A Simple System for Studying Plant Development and Reproduction.

    Science.gov (United States)

    Dyer, A. F.

    1983-01-01

    Discusses fern life cycle and basic techniques for culturing fern gametophytes in the classroom. Also discusses investigations into the reproductive biology of ferns and into the early development of gametophytes. (JN)

  12. The fern sporangium: a unique catapult.

    OpenAIRE

    Noblin, X.; Rojas, N. O.; Westbrook, J; Llorens, C.; Argentina, M.; Dumais, J.

    2012-01-01

    International audience; Various plants and fungi have evolved ingenious devices to disperse their spores. One such mechanism is the cavitation-triggered catapult of fern sporangia. The spherical sporangia enclosing the spores are equipped with a row of 12 to 13 specialized cells, the annulus. When dehydrating, these cells induce a dramatic change of curvature in the sporangium, which is released abruptly after the cavitation of the annulus cells. The entire ejection process is reminiscent of ...

  13. Thirteen new records of ferns from Brazil.

    Science.gov (United States)

    Almeida, Thais Elias; Salino, Alexandre

    2015-01-01

    Thirteen fern species are reported for the first time for Brazil. Among the new records, eight are from Acre state (Cyatheasubincisa, Cyclodiumtrianae, Elaphoglossumstenophyllum, Hypoderrisbrauniana, Pleopeltisstolzei, Thelypterisarcana, Thelypteriscomosa, Thelypterisvaldepilosa), two are from Pará state (Polypodiumflagellare, Tectariaheracleifolia), one from Minas Gerais state (Alsophilasalvinii), one from Ceará state (Campyloneurumcostatum) and one from Bahia state (Thelypterisrolandii). Part of the species shows a disjunct occurrence or illustrates floristic relations between Brazilian and Andean Mountains or Central American Mountains.

  14. Towards Resolving the Complete Fern Tree of Life

    OpenAIRE

    Samuli Lehtonen

    2011-01-01

    In the past two decades, molecular systematic studies have revolutionized our understanding of the evolutionary history of ferns. The availability of large molecular data sets together with efficient computer algorithms, now enables us to reconstruct evolutionary histories with previously unseen completeness. Here, the most comprehensive fern phylogeny to date, representing over one-fifth of the extant global fern diversity, is inferred based on four plastid genes. Parsimony and maximum-likel...

  15. The fern sporangium: an ultrafast natural catapult

    Science.gov (United States)

    Noblin, Xavier; Argentina, Mederic; Westbrook, Jared; Llorens, Coraline; Rojas, Nicolas; Dumais, Jacques

    2012-02-01

    Plants have developed fascinating mechanisms to create ultra fast movements that often reach the upper limit allowed by physical laws. Inspiration for new technologies is one of the reasons for the strong interest for these mechanisms, along with the deep interest of understanding complex, natural systems. The fern sporangium is a capsule that contains the spores, it is surrounded by a row of cells called the annulus which acts as a beam. Due to the water evaporation from its cells, the annulus bends strongly and induces elastic energy storage during an opening phase. The tension in the cells breaks when cavitation bubbles appear in the cells, leading to a fast release of the elastic energy. The fern sporangium then acts as a catapult which ejects rapidly its spores by closing back to the initial closed shape. We have analyzed the slow opening motion and the fast catapulting mechanism. We found that the catapult motion involves two time scales, showing a very original behavior. In man-made catapults, the recoil motion needs to be arrested by a cross bar so that the projectile is released from the arm. We show here that the fern sporangium replaces the essential cross bar by an elegant poroelastic damping, leading to a completely autonomous, efficient device.

  16. Chronology of guitarrero cave, peru.

    Science.gov (United States)

    Lynch, T F; Gillespie, R; Gowlett, J A; Hedges, R E

    1985-08-30

    Dating by accelerator mass spectrometry of wooden artifacts, cord, and charcoal samples from Guitarrero Cave, Peru, supports the antiquity of South America's earliest textiles and other perishable remains. The new dates are consistent with those obtained from disintegration counters and leave little doubt about the integrity of the lower Preceramic layers and their early cultivars. Re-evaluation of the mode of deposition suggests that most of the remains resulted from short-term use of the cave in the eighth millennium B.C., with a possible brief human visit as early as 12,560 years ago.

  17. Biochemical and evolutionary aspects of arthropod predation on ferns.

    Science.gov (United States)

    Balick, Michael J; Furth, David G; Cooper-Driver, Gillian

    1978-01-01

    The widely held assumption that very few arthropods feed on ferns was questioned following field observations of arthropod damage on ferns in the state of Veracruz, Mexico. The extent and type of damage was recorded and it was found that in a measured locality, ferns were no less attacked than the angiospermous flora. As chemistry and arthropod host relationships have been shown to be so closely intertwined, plants collected in the field were analysed for both condensed tannins and cyanogenic glycosides, compounds known to be effective deterrents in temperate climates. Although all ferns tested contained tannins these did not appear to inhibit predation. Cyanogenic glycosides were present in only 3% of the fern species analysed, and it is, therefore, unlikely that they play a significant role as defensive compounds in the ferns examined.A literature search revealed a large number of ferns cited as being arthropod hosts. Approximately 420 named species of arthropods have been recorded, the majority of which are from the orders Coleoptera, Hymenoptera, Lepidoptera, and Hemiptera. Both evolutionary primitive (sawflies) and advanced (moths) arthropods are reported to be present on ferns suggesting possible coevolution of arthropods and ferns both before and after the radiation of angiosperms.

  18. Primary succession of Hawaiian montane rain forest on a chronosequence of eight lava flows

    Energy Technology Data Exchange (ETDEWEB)

    Kitayama, K.; Mueller-Dombois, D. [Univ. of Hawaii at Manoa, Honolulu, HI, (United States) Dept. of Botany; Vitousek, P.M. [Stanford Univ., Stanford, CA (United States) Dept. of Biological Sciences

    1995-04-01

    The primary-successional sere of a Hawaiian montane rain forest was inferred from an age sequence of eight closely located `a`a flows (clinker type lava); 8, 50, 140, ca. 300, ca. 400, ca. 1400, ca. 3000 and ca.9000 yr, on a windward slope of Mauna Loa, Hawaii. All study sites (0.2 ha each) were at 1120-1250 m a.s.l. with 4000 mm mean annual rainfall. The 400-yr, 1400-yr, and 9000-yr flows had younger volcanic ash deposits, while the others were pure lava. Comparisons of tree size and foliar nutrients suggested that ash increased the availability of nitrogen, and subsequently standing biomass. An Unweighted Pair Group Cluster Analysis on the samples (flows) using quantitative vascular species composition revealed that clusters were correlated with age regardless of the substrate types (pure lava vs. ash), and an indirect ordination on the samples suggested that the sequence of sample scores along axis 1 was perfectly correlated with the age sequence. Although ash deposits increased biomass, they did not affect the sequence of the successional sere. Both pubescent and glabrous varieties of Metrosideros polymorpha (Myrtaceae) dominated upper canopy layers on all flows {>=} 50 yr and {<=} 1400 yr, but the pubescent variety was replaced by the glabrous on the flows {>=} 3000 yr. Lower layers were dominated initially by a mated fern, Dicranopteris linearis, up to 300 yr, and subsequently by tree ferns, Cibotium spp., to 9000 yr. The cover of Cibotium declined sightly after 3000 yr, while other native herb and shrub species increased. 43 refs, 7 figs, 4 tabs

  19. The origin of tubular lava stalactites and other related forms

    Directory of Open Access Journals (Sweden)

    Kevin Allred

    1998-01-01

    Full Text Available Tubular lava stalactites are often found in lava tubes. Field observations, sample analysis, and comparative studies indicate that these are segregations extruded during cooling from partially crystallized lava al about 1,070 - 1,000 °C. Retrograde boiling (gas pressure within the lava provides a mechanism to expel the interstitial liquid. In addition to tubular lava stalactites, a variety of other lava features can also result, such as lava helictites, lava coralloids, barnacle-like stretched lava, runners, runner channels, and some lava blisters and squeeze-ups.

  20. The cave fauna of California

    Science.gov (United States)

    William R. Elliott; James R. Reddell; D. Craig Rudolph; G.O. Graening; Thomas S. Briggs; Darrell Ubick; Rolf L. Aalbu; Jean Krejca; Steven J. Taylor

    2017-01-01

    Hidden biodiversity is revealed in this study of California's subterranean fauna, which contains distinctive elements that differentiate it from other North American regions. Since 1975, the rate of discovery of new species has accelerated with funded projects in most of the important cave areas of the state, including our own studies. Here we compile all...

  1. Distribution and dynamics of hayscented fern following stand harvest

    Science.gov (United States)

    Songlin Fei; Peter J. Gould; Melanie J. Kaeser; Kim C. Steiner

    2008-01-01

    The distribution and dynamics of hayscented fern were examined as part of a large-scale study of oak regeneration in Pennsylvania. The study included 69 stands covering 3,333 acres in two physiographic provinces. Hayscented fern was more widely distributed and occurred at higher densities in the Allegheny Plateau physiographic provinces versus the Ridge and Valley...

  2. Klukiopsis jurassica--A new Jurassic schizaeaceous fern from China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new Jurassic schizaeaceous fern Klukiopsis jurassica gen. et sp. nov. from Yima, Henan Province, China is described. The new fern is characterized by the abaxial sori arranged in two rows, apical and complete annulus and more than 800 smooth trilete spores in each sorus.

  3. Environmental conditions of Borra Cave, Visakhapattanam, India

    Directory of Open Access Journals (Sweden)

    Haraprasad Bairagya

    2014-05-01

    Full Text Available Caving is an art which can be best experienced in the mystic Borra of Eastern Ghats and ranked as the second largest cave of India just after Belum Caves situated in the same state Andhrapradesh, India. This Cave is fast becoming a hot tourist?s destination offering great adventurous opportunity to the tourists in the Eastern Ghats. The cave is located in the Ananthagiri hills of the Eastern Ghats region near Visakhapattanam and is made of limestone. The emotion of thrill heightens after entering the cave. The entrance has a narrow vertical opening and is well lit. Due to its location in the sub-equatorial region, dripping of water from the cave roofs occurs almost throughout the year. The formation of stalactites and stalagmites create wonderful phenomena specially found in this cave. The conspicuous pillars formed due to the joining of the roof and the floors are an awe-inspiring creativity of the creator of this world. Various viruses and bacteria are in the cave interior along with different other creatures. The Borra cave helps the Govt. of Andhra Pradesh, India, to earn huge economic benefits for the sake of tourism industry. DOI: http://dx.doi.org/10.3126/ije.v3i2.10526 International Journal of the Environment Vol.3(2 2014: 150-166

  4. Towards resolving the complete fern tree of life.

    Science.gov (United States)

    Lehtonen, Samuli

    2011-01-01

    In the past two decades, molecular systematic studies have revolutionized our understanding of the evolutionary history of ferns. The availability of large molecular data sets together with efficient computer algorithms, now enables us to reconstruct evolutionary histories with previously unseen completeness. Here, the most comprehensive fern phylogeny to date, representing over one-fifth of the extant global fern diversity, is inferred based on four plastid genes. Parsimony and maximum-likelihood analyses provided a mostly congruent results and in general supported the prevailing view on the higher-level fern systematics. At a deep phylogenetic level, the position of horsetails depended on the optimality criteria chosen, with horsetails positioned as the sister group either of Marattiopsida-Polypodiopsida clade or of the Polypodiopsida. The analyses demonstrate the power of using a 'supermatrix' approach to resolve large-scale phylogenies and reveal questionable taxonomies. These results provide a valuable background for future research on fern systematics, ecology, biogeography and other evolutionary studies.

  5. Thirteen new records of ferns from Brazil

    Directory of Open Access Journals (Sweden)

    Thais Almeida

    2015-02-01

    Full Text Available Thirteen fern species are reported for the first time for Brazil. Among the new records, eight are from Acre state (Cyathea subincisa, Cyclodium trianae, Elaphoglossum stenophyllum, Hypoderris brauniana, Pleopeltis stolzei, Thelypteris arcana, Thelypteris comosa, Thelypteris valdepilosa, two are from Pará state (Polypodium flagellare, Tectaria heracleifolia, one from Minas Gerais state (Alsophila salvinii, one from Ceará state (Campyloneurum costatum and one from Bahia state (Thelypteris rolandii. Part of the species shows a disjunct occurrence or illustrates floristic relations between Brazilian and Andean Mountains or Central American Mountains.

  6. Chloroplast genome evolution in early diverged leptosporangiate ferns.

    Science.gov (United States)

    Kim, Hyoung Tae; Chung, Myong Gi; Kim, Ki-Joong

    2014-05-01

    In this study, the chloroplast (cp) genome sequences from three early diverged leptosporangiate ferns were completed and analyzed in order to understand the evolution of the genome of the fern lineages. The complete cp genome sequence of Osmunda cinnamomea (Osmundales) was 142,812 base pairs (bp). The cp genome structure was similar to that of eusporangiate ferns. The gene/intron losses that frequently occurred in the cp genome of leptosporangiate ferns were not found in the cp genome of O. cinnamomea. In addition, putative RNA editing sites in the cp genome were rare in O. cinnamomea, even though the sites were frequently predicted to be present in leptosporangiate ferns. The complete cp genome sequence of Diplopterygium glaucum (Gleicheniales) was 151,007 bp and has a 9.7 kb inversion between the trnL-CAA and trnVGCA genes when compared to O. cinnamomea. Several repeated sequences were detected around the inversion break points. The complete cp genome sequence of Lygodium japonicum (Schizaeales) was 157,142 bp and a deletion of the rpoC1 intron was detected. This intron loss was shared by all of the studied species of the genus Lygodium. The GC contents and the effective numbers of codons (ENCs) in ferns varied significantly when compared to seed plants. The ENC values of the early diverged leptosporangiate ferns showed intermediate levels between eusporangiate and core leptosporangiate ferns. However, our phylogenetic tree based on all of the cp gene sequences clearly indicated that the cp genome similarity between O. cinnamomea (Osmundales) and eusporangiate ferns are symplesiomorphies, rather than synapomorphies. Therefore, our data is in agreement with the view that Osmundales is a distinct early diverged lineage in the leptosporangiate ferns.

  7. A Catskill Flora and Economic Botany, I: Pteridophyta. The Ferns and Fern Allies. Bulletin No. 438, New York State Museum.

    Science.gov (United States)

    Brooks, Karl L.

    The information contained within this guide about flora of the ferns and fern allies of the Catskill Mountains of New York State covers medical and food uses of the plants, as well as the more typical floristic data of keys, drawings, and plant descriptions. (CS)

  8. What factors control superficial lava dome explosivity?

    Science.gov (United States)

    Boudon, Georges; Balcone-Boissard, Hélène; Villemant, Benoît; Morgan, Daniel J.

    2015-09-01

    Dome-forming eruption is a frequent eruptive style and a major hazard on numerous volcanoes worldwide. Lava domes are built by slow extrusion of degassed, viscous magma and may be destroyed by gravitational collapse or explosion. The triggering of lava dome explosions is poorly understood: here we propose a new model of superficial lava-dome explosivity based upon a textural and geochemical study (vesicularity, microcrystallinity, cristobalite distribution, residual water contents, crystal transit times) of clasts produced by key eruptions. Superficial explosion of a growing lava dome may be promoted through porosity reduction caused by both vesicle flattening due to gas escape and syn-eruptive cristobalite precipitation. Both processes generate an impermeable and rigid carapace allowing overpressurisation of the inner parts of the lava dome by the rapid input of vesiculated magma batches. The relative thickness of the cristobalite-rich carapace is an inverse function of the external lava dome surface area. Explosive activity is thus more likely to occur at the onset of lava dome extrusion, in agreement with observations, as the likelihood of superficial lava dome explosions depends inversely on lava dome volume. This new result is of interest for the whole volcanological community and for risk management.

  9. Characterizing Lava Flows With LiDAR

    Science.gov (United States)

    Deligne, N. I.; Cashman, K. V.; Deardorff, N.; Dietterich, H. R.; House, P. K.; Soule, S.

    2009-12-01

    Digital elevation models (DEMs) have been used in volcanology in predictive modeling of lava flow paths, both for assessment of potential hazards and specific predictions of lava flow paths. Topographic analysis of a lava flow is potentially useful for mapping and quantifying flow surface morphologies, which in turn can be used to determine flow emplacement conditions, such as effusion rate, steadiness of flow, and interactions with pre-existing topography and surface water. However, this has been limited in application because of the coarse resolution of most DEMs. In recent years, use of Light Detection and Ranging (LiDAR) airborne laser altimetry, capable of producing high resolution (≤ 1 meter) DEMs, has become increasingly common in the geomorphic and mapping community. However, volcanologists have made little use of airborne LiDAR. Here we compare information obtained using field observations and standard (10 meter) DEMs against LiDAR high resolution DEMs to assess the usefulness, capabilities, and limitations of LiDAR as applicable to lava flows. We compare morphologic characteristics of five lava flows of different compositions, tectonic settings, flow extents, slopes, and eruption duration: (1) 1984 Mauna Loa lava flow, Hawaii; (2) December 1974 Kilauea lava flow, Hawaii; (3) c. 1600 ybp Collier Cone lava flow, central Oregon Cascades; (4) Holocene lava flows from the Sand Mountain volcanic chain, central Oregon Cascades; and (5) Pleistocene lava flows along the Owyhee River, eastern Oregon basin and range. These lava flows range in composition from basalt to andesite, and have eruption durations ranging from 6 hours (observed) to years (inferred). We measure channel width, levee and flow front heights, compression ridge amplitude, wavelength and tumuli dimensions, and surface roughness. For all but the smallest scale features, LiDAR is easily used to quantify these features, which often is impossible or technically challenging to do in the field, while

  10. Utility of Lava Tubes on Other Worlds

    Science.gov (United States)

    Walden, Bryce E.; Billings, T. L.; York, Cheryl Lynn; Gillett, S. L.; Herbert, M. V.

    1998-01-01

    On Mars, as on Earth, lava tubes are found in the extensive lava fields associated with shield volcanism. Lunar lava-tube traces are located near mare-highland boundaries, giving access to a variety of minerals and other resources, including steep slopes, prominent heights for local area communications and observation, large-surface areas in shade, and abundant basalt plains suitable for landing sites, mass-drivers, surface transportation, regolith harvesting, and other uses. Methods for detecting lava tubes include visual observations of collapse trenches and skylights, ground-penetrating radar, gravimetry, magnetometry, seismography, atmospheric effects, laser, lidar, infrared, and human or robotic exploration.

  11. Using CAVE technology for functional genomics studies.

    Science.gov (United States)

    Sensen, Christoph W

    2002-01-01

    We have established the first Java 3D-enabled CAVE (CAVE automated virtual environment). The Java application programming interface allows the complete separation of the program development from the program execution, opening new application domains for the CAVE technology. Programs can be developed on any Java-enabled computer platform, including Windows, Macintosh, and Linux workstations, and executed in the CAVE without modification. The introduction of Java, one of the major programming environments for bioinformatics, into the CAVE environment allows the rapid development applications for genome research, especially for the analysis of the spatial and temporal data that are being produced by functional genomics experiments. The CAVE technology will play a major role in the modeling of biological systems that is necessary to understand how these systems are organized and how they function.

  12. Effects of temperature and desiccation on ex situ conservation of nongreen fern spores

    Science.gov (United States)

    Conservation of the genetic diversity of ferns is limited by the paucity of ex situ spore banks. Conflicting reports of fern spore response to low temperature and moisture impedes establishment of fern spore banks. There is little information available to evaluate longevity of fern spores under dif...

  13. Volcanic caves of East Africa - an overview

    Directory of Open Access Journals (Sweden)

    Jim W. Simons

    1998-01-01

    Full Text Available Numerous Tertiary to recent volcanoes are located in East Africa. Thus, much of the region is made up volcanic rock, which hosts the largest and greatest variety of East Africas caves. Exploration of volcanic caves has preoccupied members of Cave Exploration Group of East Africa (CEGEA for the past 30 years. The various publications edited by CEGEA are in this respect a treasure troves of speleological information. In the present paper an overview on the most important volcanic caves and areas are shortly reported.

  14. Cave temperatures and global climatic change.

    Directory of Open Access Journals (Sweden)

    Badino Giovanni

    2004-12-01

    Full Text Available The physical processes that establish the cave temperature are briefly discussed, showing that cave temperature is generally strictly connected with the external climate. The Global Climatic changes can then influence also the underground climate. It is shown that the mountain thermal inertia causes a delay between the two climates and then a thermal unbalance between the cave and the atmosphere. As a consequence there is a net energy flux from the atmosphere to the mountain, larger than the geothermal one, which is deposited mainly in the epidermal parts of caves.

  15. Caves and Karsts of Northeast Africa.

    Directory of Open Access Journals (Sweden)

    Halliday William R.

    2003-01-01

    Full Text Available At least potentially karstifiable rocks cover much of the surface of Egypt and northern Libya. Study of caves and other karstic features of this region has been hampered by lack of roads, rapid disintegration of the surface of friable, poorly consolidated limestone, wind-blown sand and other factors. Interbedding with marly aquicludes hampers speleogenesis locally. Calcareous and evaporite karsts are present, however, and their waters are important albeit generally limited resources. Large quantities of fresh water are lost through submarine springs downslope from Libya’s Gebel al Akhdar range; the caves and karst of that range may be among the world’s greatest. A recent attempted compendium of caves and karsts of Egypt and Libya contains several important errors; the supposed 5+ km Ain Zayanah Cave does not exist and the Zayanah System includes several smaller caves. The Bir al Ghanam gypsum karst of northwest Libya, however, has caves up to 3.5 km long. In Egypt, the Mokattam, South Galala, Ma’aza, Siwa and Western Desert karsts and the “White Desert” chalk karst of Farafra Depression are especially important. Qattara and nearby depressions may be karstic rather than structural in origin. Unique Wadi Sannur Cave is the world’s largest gour and a potential World Heritage site. Little knownsandstone karsts or pseudokarsts in southwestern Egypt may contain analogues of features recently identified on Mars. The well-publicised Uweinat caves of northwestern Sudan are talus caves.

  16. Emplacing a Cooling-Limited Rhyolite Lava Flow: Similarities with Basaltic Lava Flows

    Directory of Open Access Journals (Sweden)

    Nathan Magnall

    2017-06-01

    Full Text Available Accurate forecasts of lava flow length rely on estimates of eruption and magma properties and, potentially more challengingly, on an understanding of the relative influence of characteristics such as the apparent viscosity, the yield strength of the flow core, or the strength of the lava's surface crust. For basaltic lavas, the relatively high frequency of eruptions has resulted in numerous opportunities to test emplacement models on such low silica lava flows. However, the flow of high silica lava is much less well understood due to the paucity of contemporary events and, if observations of flow length change are used to constrain straightforward models of lava advance, remaining uncertainties can limit the insight gained. Here, for the first time, we incorporate morphological observations from during and after flow field evolution to improve model constraints and reduce uncertainties. After demonstrating the approach on a basaltic lava flow (Mt. Etna 2001, we apply it to the 2011–2012 Cordón Caulle rhyolite lava flow, where unprecedented observations and syn-emplacement satellite imagery of an advancing silica-rich lava flow have indicated an important influence from the lava flow's crust on flow emplacement. Our results show that an initial phase of viscosity-controlled advance at Cordón Caulle was followed by later crustal control, accompanied by formation of flow surface folds and large-scale crustal fractures. Where the lava was unconstrained by topography, the cooled crust ultimately halted advance of the main flow and led to the formation of breakouts from the flow front and margins, influencing the footprint of the lava, its advance rate, and the duration of flow advance. Highly similar behavior occurred in the 2001 Etna basaltic lava flow. In our comparison of these two cases, we find close similarities between the processes controlling the advance of a crystal-poor rhyolite and a basaltic lava flow, suggesting common controlling

  17. Evolutionary Conservation of ABA Signaling for Stomatal Closure in Ferns.

    Science.gov (United States)

    Cai, Shengguan; Chen, Guang; Wang, Yuanyuan; Huang, Yuqing; Marchant, Blaine; Wang, Yizhou; Yang, Qian; Dai, Fei; Hills, Adrian; Franks, Peter J; Nevo, Eviatar; Soltis, Doug; Soltis, Pamela; Sessa, Emily; Wolf, Paul G; Xue, Dawei; Zhang, Guoping; Pogson, Barry J; Blatt, Mike R; Chen, Zhong-Hua

    2017-02-23

    ABA-driven stomatal regulation reportedly evolved after the divergence of ferns, during the early evolution of seed plants approximately 360 Mya. This hypothesis is based on the observation that the stomata of certain fern species are unresponsive to ABA, but exhibit passive hydraulic control. However, ABA-induced stomatal closure was detected in some mosses and lycophytes. Here, we observed that a number of ABA signaling and membrane transporter protein families diversified over the evolutionary history of land plants. The aquatic ferns Azolla filiculoides and Salvinia cucullata have representatives of 23 families of proteins orthologous to those of Arabidopsis thaliana and all other land plant species studied. Phylogenetic analysis of the key ABA signaling proteins indicates an evolutionarily conserved stomatal response to ABA. Moreover, comparative transcriptomic analysis has identified a suite of ABA responsive genes that differentially expressed in a terrestrial fern species, Polystichum proliferum. These genes encode proteins associated with ABA biosynthesis, transport, reception, transcription, signaling, and ion and sugar transport, which fit the general ABA signaling pathway constructed from Arabidopsis thaliana and Hordeum vulgare. The retention of these key ABA-responsive genes could have had a profound effect on the adaptation of ferns to dry conditions. Furthermore, stomatal assays have shown the primary evidence for ABA-induced closure of stomata in two terrestrial fern species P. proliferum and Nephrolepis exaltata. In summary, we report new molecular and physiological evidence for the presence of active stomatal control in ferns.

  18. First insights into fern matK phylogeny.

    Science.gov (United States)

    Kuo, Li-Yaung; Li, Fay-Wei; Chiou, Wen-Liang; Wang, Chun-Neng

    2011-06-01

    MatK, the only maturase gene in the land plant plastid genome, is a very popular phylogenetic marker that has been extensively applied in reconstructing angiosperm phylogeny. However, the use of matK in fern phylogeny is largely unknown, due to difficulties with amplification: ferns have lost the flanking trnK exons, typically the region used for designing stable priming sites. We developed primers that are either universal or lineage-specific that successfully amplify matK across all fern families. To evaluate whether matK is as powerful a phylogenetic marker in ferns as in angiosperms, we compared its sequence characteristics and phylogenetic performance to those of rbcL and atpA. Among these three genes, matK has the highest variability and substitution evenness, yet shows the least homoplasy. Most importantly, applying matK in fern phylogenetics better resolved relationships among families, especially within eupolypods I and II. Here we demonstrate the power of matK for fern phylogenetic reconstruction, as well as provide primers and extensive sequence data that will greatly facilitate future evolutionary studies of ferns.

  19. The evolution, morphology and development of fern leaves

    Directory of Open Access Journals (Sweden)

    Alejandra eVasco

    2013-09-01

    Full Text Available Leaves are lateral determinate structures formed in a predictable sequence (phyllotaxy on the flanks of an indeterminate shoot apical meristem. The origin and evolution of leaves in vascular plants has been widely debated. Being the main conspicuous organ of nearl all vascular plants and often easy to recognize as such, it seems surprising that leaves have had multiple origins. For decades, morphologists, anatomists, paleobotanists, and systematists have contributed data to this debate. More recently, molecular genetic studies have provided insight into leaf evolution and development mainly within angiosperms and, to a lesser extent, lycophytes. There has been recent interest in extending leaf evolutionary developmental studies to other species and lineages, particularly in lycophytes and ferns. Therefore, a review of fern leaf morphology, evolution and development is timely. Here we discuss the theories of leaf evolution in ferns, morphology and diversity of fern leaves, and experimental results of fern leaf development. We summarize what is known about the molecular genetics of fern leaf development and what future studies might tell us about the evolution of fern leaf development.

  20. Geologic field-trip guide to Medicine Lake Volcano, northern California, including Lava Beds National Monument

    Science.gov (United States)

    Donnelly-Nolan, Julie M.; Grove, Timothy L.

    2017-08-17

    Medicine Lake volcano is among the very best places in the United States to see and walk on a variety of well-exposed young lava flows that range in composition from basalt to rhyolite. This field-trip guide to the volcano and to Lava Beds National Monument, which occupies part of the north flank, directs visitors to a wide range of lava flow compositions and volcanic phenomena, many of them well exposed and Holocene in age. The writing of the guide was prompted by a field trip to the California Cascades Arc organized in conjunction with the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) quadrennial meeting in Portland, Oregon, in August of 2017. This report is one of a group of three guides describing the three major volcanic centers of the southern Cascades Volcanic Arc. The guides describing the Mount Shasta and Lassen Volcanic Center parts of the trip share an introduction, written as an overview to the IAVCEI field trip. However, this guide to Medicine Lake volcano has descriptions of many more stops than are included in the 2017 field trip. The 23 stops described here feature a range of compositions and volcanic phenomena. Many other stops are possible and some have been previously described, but these 23 have been selected to highlight the variety of volcanic phenomena at this rear-arc center, the range of compositions, and for the practical reason that they are readily accessible. Open ground cracks, various vent features, tuffs, lava-tube caves, evidence for glaciation, and lava flows that contain inclusions and show visible evidence of compositional zonation are described and visited along the route.

  1. Martian cave air-movement via Helmholtz resonance

    Science.gov (United States)

    Williams, Kaj; Titus, Timothy N.; Okubo, Chris; Cushing, Glen

    2017-01-01

    Infrasonic resonance has previously been measured in terrestrial caves by other researchers, where Helmholtz resonance has been suggested as the plausible mechanism resulting in periodic wind reversals within cave entrances. We extend this reasoning to possible Martian caves, where we examine the characteristics of four atypical pit craters (APCs) on Tharsis, suggested as candidate cave entrance locations. The results show that, for several possible cave air movement periods, we are able to infer the approximate cave volumes. The utility of inferring cave volumes for planetary cave exploration is discussed.

  2. Propagation style controls lava-snow interactions.

    Science.gov (United States)

    Edwards, B R; Belousov, A; Belousova, M

    2014-12-16

    Understanding interactions between volcanic eruptions and the cryosphere (a.k.a. glaciovolcanism) is important for climate reconstructions as well as for hazard mitigation at ice-clad volcanoes. Here we present unique field observations of interactions between snowpack and advancing basaltic lava flows during the 2012-13 eruption at Tolbachik volcano, Kamchatka, Russia. Our observations show that lava-snow heat transfer is slow, and that styles of lava propagation control snowpack responses. 'A'a and sheet lava flows advance in a rolling caterpillar-track motion on top of the rigid, snowpack substrate with minor lava-snow interaction. In contrast, pahoehoe lava propagates by inflation of lobes beneath/inside the snowpack, producing rigorous lava-snow interaction via meltwater percolation down into the incandescent lava causing production of voluminous steam, rapid surface cooling and thermal shock fragmentation. The textures produced by pahoehoe-snowpack interactions are distinctive and, where observed at other sites, can be used to infer syn-eruption seasonality and climatic conditions.

  3. Tephra on Lava Flows Promotes Vegetation Development: Case Studies From Recent Holocene Lava Flows

    Science.gov (United States)

    Deligne, N. I.; Cashman, K. V.

    2011-12-01

    Volcanic eruptions re-surface landscapes rapidly with lava flows, pyroclastic deposits, or a combination of both. Whereas explosive deposits are generally fine grained and share many characteristics with fertile soil, lava does not - it is massive, fractured, and sterile rock. As such, barren lava presents a formidable challenge for plant colonization. However, most lava-forming eruptions have an explosive component, albeit often in the early stages of activity prior to lava emplacement when the magma still has a considerable gas fraction. Tephra from the explosive stage of an eruption blankets local and downwind areas, and tephra thickness decreases exponentially with distance from the vent. We examine several sites of Holocene volcanism in the United States, Mexico, and Italy and find that in the absence of tephra or external sources of soil, vegetation establishment and growth on lava flows is exceptionally slow. Conversely, lava flows with late stage syn-eruptive explosive activity or lava flows in areas with subsequent repeat volcanism have considerable vegetation development. Although thick tephra blankets hinder plant establishment, it appears that tephra deposits on lava flows provide a growth medium and enhances water retention, promoting plant colonization and vegetation development. Our results caution against the common practice of mapping lava flows based on vegetation, and provide new insights on key factors in plant establishment and growth on lava flows.

  4. Chemical deposits in evaporite caves: an overview

    Directory of Open Access Journals (Sweden)

    Paolo Forti

    2017-06-01

    Full Text Available Chemical deposits inside evaporite (gypsum, anhydrite and halite caves are far less common than those developed within limestone or volcanic cavities. Moreover they exhibit a lower scarce mineralogical variability due to several reasons, the most important of which are: 1 calcium sulfate and sodium chloride are by far less reactive than calcium carbonate; 2 evaporite outcrops normally have a low mineralogical variability within the cave recharge areas. Therefore these karst environments were less investigated from this point of view in the past: no general paper exists on speleothems developing in halite and anhydrite caves until present, while the last printed one on gypsum (and anhydrite karst appeared around 20 years ago. Several mineralogical studies were carried out in the last decades in caves from different evaporite areas proving that some of them host peculiar minerogenetic mechanisms, which are, at the moment, exclusive for these areas, and sometimes also brought to light to rare or even new cave minerals. In the present paper, together with an overview on all the actually known minerogenetic mechanisms active within the evaporite caves, the related chemical deposits and speleothems are shortly described. Far from being exhaustive, the recent mineralogical research on evaporite caves puts in evidence their unexpected richness in peculiar hosted speleothems and rare cave deposits. Seven out of the fifty known evaporite cave minerals, and around 10 speleothem types/subtypes are exclusive to these environments. Taking into account that only a few evaporite areas have been, so far, studied, it is highly probable that in the near future many more new cave deposits will be discovered, thus increasing the mineralogical interest of these unique caves.

  5. Modeling and analysis of caves using voxelization

    Science.gov (United States)

    Szeifert, Gábor; Szabó, Tivadar; Székely, Balázs

    2014-05-01

    Although there are many ways to create three dimensional representations of caves using modern information technology methods, modeling of caves has been challenging for researchers for a long time. One of these promising new alternative modeling methods is using voxels. We are using geodetic measurements as an input for our voxelization project. These geodetic underground surveys recorded the azimuth, altitude and distance of corner points of cave systems relative to each other. The diameter of each cave section is estimated from separate databases originating from different surveys. We have developed a simple but efficient method (it covers more than 99.9 % of the volume of the input model on the average) to convert these vector-type datasets to voxels. We have also developed software components to make visualization of the voxel and vector models easier. Since each cornerpoint position is measured relative to another cornerpoints positions, propagation of uncertainties is an important issue in case of long caves with many separate sections. We are using Monte Carlo simulations to analyze the effect of the error of each geodetic instrument possibly involved in a survey. Cross-sections of the simulated three dimensional distributions show, that even tiny uncertainties of individual measurements can result in high variation of positions that could be reduced by distributing the closing errors if such data are available. Using the results of our simulations, we can estimate cave volume and the error of the calculated cave volume depending on the complexity of the cave. Acknowledgements: the authors are grateful to Ariadne Karst and Cave Exploring Association and State Department of Environmental and Nature Protection of the Hungarian Ministry of Rural Development, Department of National Parks and Landscape Protection, Section Landscape and Cave Protection and Ecotourism for providing the cave measurement data. BS contributed as an Alexander von Humboldt Research

  6. The fern sporangium: a unique catapult.

    Science.gov (United States)

    Noblin, X; Rojas, N O; Westbrook, J; Llorens, C; Argentina, M; Dumais, J

    2012-03-16

    Various plants and fungi have evolved ingenious devices to disperse their spores. One such mechanism is the cavitation-triggered catapult of fern sporangia. The spherical sporangia enclosing the spores are equipped with a row of 12 to 13 specialized cells, the annulus. When dehydrating, these cells induce a dramatic change of curvature in the sporangium, which is released abruptly after the cavitation of the annulus cells. The entire ejection process is reminiscent of human-made catapults with one notable exception: The sporangia lack the crossbar that arrests the catapult arm in its returning motion. We show that much of the sophistication and efficiency of the ejection mechanism lies in the two very different time scales associated with the annulus closure.

  7. Some new external flavonoids from American ferns

    Energy Technology Data Exchange (ETDEWEB)

    Wollenweber, E.

    1979-01-01

    American gymnogrammoid ferns have been analysed for the flavonoid aglycones present in frond exudates. They are predominantly methylated chalcones, dihydrochalcones, flavones, and flavonols, occurring mostly as farinose deposit (''ceraceous indument''). This is the first report of external flavonoids on Pterozonium species; a chalcone has been identified. On Cheilanthes kaulfussii and Cheilanthes viscida traces of flavonoid aglycones are observed, dissolved in lipophilic exudate material. On Pellaea longimucronata a flavonol is found even on leaves which appear glaucous. 2',4',6'-Trihydroxychalcone is found for the second time in the plant kingdom on Adiantum sulphureum. Galangin-3,7-dimethylether is found as a new natural flavonol on Cheilanthes kaulfussii. In addition, samples of Pityrogramma chrysoconia and Pit. triangularis var. maxonii have been investigated. The results indicate chemotaxonomic implication of flavonoid patterns.

  8. Gravity for Detecting Caves: Airborne and Terrestrial Simulations Based on a Comprehensive Karstic Cave Benchmark

    Science.gov (United States)

    Braitenberg, Carla; Sampietro, Daniele; Pivetta, Tommaso; Zuliani, David; Barbagallo, Alfio; Fabris, Paolo; Rossi, Lorenzo; Fabbri, Julius; Mansi, Ahmed Hamdi

    2016-04-01

    Underground caves bear a natural hazard due to their possible evolution into a sink hole. Mapping of all existing caves could be useful for general civil usages as natural deposits or tourism and sports. Natural caves exist globally and are typical in karst areas. We investigate the resolution power of modern gravity campaigns to systematically detect all void caves of a minimum size in a given area. Both aerogravity and terrestrial acquisitions are considered. Positioning of the gravity station is fastest with GNSS methods the performance of which is investigated. The estimates are based on a benchmark cave of which the geometry is known precisely through a laser-scan survey. The cave is the Grotta Gigante cave in NE Italy in the classic karst. The gravity acquisition is discussed, where heights have been acquired with dual-frequency geodetic GNSS receivers and Total Station. Height acquisitions with non-geodetic low-cost receivers are shown to be useful, although the error on the gravity field is larger. The cave produces a signal of -1.5 × 10-5 m/s2, with a clear elliptic geometry. We analyze feasibility of airborne gravity acquisitions for the purpose of systematically mapping void caves. It is found that observations from fixed wing aircraft cannot resolve the caves, but observations from slower and low-flying helicopters or drones do. In order to detect the presence of caves the size of the benchmark cave, systematic terrestrial acquisitions require a density of three stations on square 500 by 500 m2 tiles. The question has a large impact on civil and environmental purposes, since it will allow planning of urban development at a safe distance from subsurface caves. The survey shows that a systematic coverage of the karst would have the benefit to recover the position of all of the greater existing void caves.

  9. Millipedes (Diplopoda) from caves of Portugal

    DEFF Research Database (Denmark)

    P. S. Reboleira, Ana Sofia; Enghoff, Henrik

    2014-01-01

    in caves of the mainland and the island of Madeira has provided new data about the distribution and diversity of millipedes. A review of millipedes from caves of Portugal is presented, listing fourteen species belonging to eight families, among which six species are considered troglobionts...

  10. Radiocarbon intercomparison program for Chauvet Cave

    NARCIS (Netherlands)

    Cuzange, Marie-Therese; Delque-Kolic, Emmanuelle; Goslar, Tomasz; Grootes, Pieter Meiert; Higham, Tom; Kaltnecker, Evelyne; Nadeau, Marie-Josee; Oberlin, Christine; Paterne, Martine; van der Plicht, Johannes; Ramsey, Christopher Bronk; Valladas, Helene; Clottes, Jean; Geneste, Jean-Michel

    2007-01-01

    We present the first results of an accelerator mass spectrometry (AMS) radiocarbon intercomparison program on 3 different charcoal samples collected in one of the hearths of the Megaceros gallery of Chauvet Cave (Ardeche, France). This cave, rich in parietal decoration, is important for the study of

  11. Cavernous hemangioma of Meckel's cave. Case report.

    Science.gov (United States)

    Fehlings, M G; Tucker, W S

    1988-04-01

    A case of a cavernous hemangioma located within Meckel's cave and involving the gasserian ganglion is described in a patient presenting with facial pain and a trigeminal nerve deficit. Although these lesions have been reported to occur in the middle fossa, this is believed to be the first case of such a vascular malformation arising solely from within Meckel's cave.

  12. [Anatomic variants of Meckel's cave on MRI].

    Science.gov (United States)

    Benoudiba, F; Hadj-Rabia, M; Iffenecker, C; Fuerxer, F; Bekkali, F; Francke, J P; Doyon, D

    1998-10-01

    Magnetic resonance imaging (MRI) gives an accurate analysis of Meckel's cave variability. Images were acquired in 50 patients with several sections for anatomical comparison. Using several sections, MRI is a suitable method for better analysis of the trigeminal cistern. The most frequent findings are symmetrical trigeminal cisterns. Expansion of Meckel's cave or its disappearance has pathological significance.

  13. Radiocarbon intercomparison program for Chauvet Cave

    NARCIS (Netherlands)

    Cuzange, Marie-Therese; Delque-Kolic, Emmanuelle; Goslar, Tomasz; Grootes, Pieter Meiert; Higham, Tom; Kaltnecker, Evelyne; Nadeau, Marie-Josee; Oberlin, Christine; Paterne, Martine; van der Plicht, Johannes; Ramsey, Christopher Bronk; Valladas, Helene; Clottes, Jean; Geneste, Jean-Michel

    2007-01-01

    We present the first results of an accelerator mass spectrometry (AMS) radiocarbon intercomparison program on 3 different charcoal samples collected in one of the hearths of the Megaceros gallery of Chauvet Cave (Ardeche, France). This cave, rich in parietal decoration, is important for the study of

  14. THE ANTIMICROBIAL ACTIVITY OF SOME EXTRACTS OF FERN GAMETOPHYTES

    Directory of Open Access Journals (Sweden)

    Ionica Deliu

    2013-12-01

    Full Text Available The nature freely offers us many resources for health and beauty. The ferns and their therapeutic properties are less exploit in Romania, except Lycopodium clavatum and Equisetum arvense. Some of the fern properties were demonstrated, like antioxidant, antimicrobial, antiviral, antihelmintic properties. Plants are reasonable alternative to synthetic drugs, avoid the side effect and high cost of synthetic drugs production. Also, the drug resistance bacteria can be controlled using plant derived remedies. In this study the antimicrobial effect of methanolic and ethanolic extracts from three fern species were tested. The extracts were gained from gametophytic stage of ferns obtained in vitro. The most obvious effect was observed for Asplenium trichomanes-ramosum extract. The total polyphenols and flavonoids content were established, too.

  15. Status Report, Phyllitis scolopendrium (L.) Newm. Var. Americana Fern

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Status report concerning theAmerican Hart's Tongue Fern in the US and Canada is reviwed concerning all known populations - including those presumed to be extirpated....

  16. Fern Biology in Mexico - (A Class Field Program)

    Science.gov (United States)

    Tryon, Rolla; And Others

    1973-01-01

    Organized field trips in the tropics proved to be an effective way to gather new information about ferns. The areas of study covered were: systematics and ecology, cytology and gametophyte structure, and morphogenesis and physiology. (PS)

  17. Using Water Clover to Demonstrate Sexual Reproduction in Ferns.

    Science.gov (United States)

    Settle, Wilbur J.

    1980-01-01

    Procedures are described for preparing spores from the fern, water clover, for an educational demonstration of germination and sexual reproduction. The demonstration is recommended for biology instructors who want to illustrate the alternation of phases in plants. (SA)

  18. THE ANTIMICROBIAL ACTIVITY OF SOME EXTRACTS OF FERN GAMETOPHYTES

    OpenAIRE

    Ionica Deliu; Carmen Bejan; Emilia Vişoiu; Liliana Cristina Soare

    2013-01-01

    The nature freely offers us many resources for health and beauty. The ferns and their therapeutic properties are less exploit in Romania, except Lycopodium clavatum and Equisetum arvense. Some of the fern properties were demonstrated, like antioxidant, antimicrobial, antiviral, antihelmintic properties. Plants are reasonable alternative to synthetic drugs, avoid the side effect and high cost of synthetic drugs production. Also, the drug resistance bacteria can be controlled using plant derive...

  19. Gene transfer from a parasitic flowering plant to a fern

    OpenAIRE

    Davis, Charles C.; Anderson, William R.; Wurdack, Kenneth J

    2005-01-01

    The rattlesnake fern (Botrychium virginianum (L.) Sw.) is obligately mycotrophic and widely distributed across the northern hemisphere. Three mitochondrial gene regions place this species with other ferns in Ophioglossaceae, while two regions place it as a member of the largely parasitic angiosperm order Santalales (sandalwoods and mistletoes). These discordant phylogenetic placements suggest that part of the genome in B. virginianum was acquired by horizontal gene transfer (HGT), perhaps fro...

  20. The evolution of chloroplast genome structure in ferns.

    Science.gov (United States)

    Wolf, Paul G; Roper, Jessie M; Duffy, Aaron M

    2010-09-01

    The plastid genome (plastome) is a rich source of phylogenetic and other comparative data in plants. Most land plants possess a plastome of similar structure. However, in a major group of plants, the ferns, a unique plastome structure has evolved. The gene order in ferns has been explained by a series of genomic inversions relative to the plastome organization of seed plants. Here, we examine for the first time the structure of the plastome across fern phylogeny. We used a PCR-based strategy to map and partially sequence plastomes. We found that a pair of partially overlapping inversions in the region of the inverted repeat occurred in the common ancestor of most ferns. However, the ancestral (seed plant) structure is still found in early diverging branches leading to the osmundoid and filmy fern lineages. We found that a second pair of overlapping inversions occurred on a branch leading to the core leptosporangiates. We also found that the unique placement of the gene matK in ferns (lacking a flanking intron) is not a result of a large-scale inversion, as previously thought. This is because the intron loss maps to an earlier point on the phylogeny than the nearby inversion. We speculate on why inversions may occur in pairs and what this may mean for the dynamics of plastome evolution.

  1. Denuded cave in Podbojev laz, Rakov Škocjan

    Directory of Open Access Journals (Sweden)

    Uroš Stepišnik

    2009-12-01

    Full Text Available This paper presents a denuded cave situated in the area of Podbojev laz, on the northwestern side of the Rakov Škocjan. Morphometric and morphogenetic properties of several sections of the denuded cave and its surroundings are described in detail. The denuded cave developed from an epiphreatic cave system which used to function as an outflow cave system from the Rak valley. Morphometrical analysis of the slopes show that the denuded cave was developedin stages. As the surrounding surface is not flattened, the cave roof must have been denuded gradually.

  2. Taylor instability in rhyolite lava flows

    Science.gov (United States)

    Baum, B. A.; Krantz, W. B.; Fink, J. H.; Dickinson, R. E.

    1989-01-01

    A refined Taylor instability model is developed to describe the surface morphology of rhyolite lava flows. The effect of the downslope flow of the lava on the structures resulting from the Taylor instability mechanism is considered. Squire's (1933) transformation is developed for this flow in order to extend the results to three-dimensional modes. This permits assessing why ridges thought to arise from the Taylor instability mechanism are preferentially oriented transverse to the direction of lava flow. Measured diapir and ridge spacings for the Little and Big Glass Mountain rhyolite flows in northern California are used in conjunction with the model in order to explore the implications of the Taylor instability for flow emplacement. The model suggests additional lava flow features that can be measured in order to test whether the Taylor instability mechanism has influenced the flows surface morphology.

  3. Development, management and economy of show caves.

    Directory of Open Access Journals (Sweden)

    Cigna Arrigo A.

    2000-01-01

    Full Text Available The problems concerning the development of show caves are here considered by taking into account different aspects of the problem. A procedure to carry out an Environmental Impact Assessment (EIA has been established in the last decade and it is now currently applied. Such an assessment starts with a pre-operational phase to obtain sufficient information on the undisturbed status of a cave to be developed into a show cave. Successively a programme for its development is established with the scope to optimise the intervention on the cave at the condition that its basic environmental parameters are not irreversibly modified. The last phase of the assessment is focussed to assure a feedback through a monitoring network in order to detect any unforeseen difference or anomaly between the project and the effective situation achieved after the cave development. Some data on some of the most important show caves in the world are reported and a tentative evaluation of the economy in connection with the show caves business is eventually made.

  4. Determination of eruption temperature of Io's lavas using lava tube skylights

    Science.gov (United States)

    Davies, Ashley Gerard; Keszthelyi, Laszlo P.; McEwen, Alfred S.

    2016-11-01

    Determining the eruption temperature of Io's dominant silicate lavas would constrain Io's present interior state and composition. We have examined how eruption temperature can be estimated at lava tube skylights through synthesis of thermal emission from the incandescent lava flowing within the lava tube. Lava tube skylights should be present along Io's long-lived lava flow fields, and are attractive targets because of their temporal stability and the narrow range of near-eruption temperatures revealed through them. We conclude that these skylights are suitable and desirable targets (perhaps the very best targets) for the purposes of constraining eruption temperature, with a 0.9:0.7-μm radiant flux ratio ≤6.3 being diagnostic of ultramafic lava temperatures. Because the target skylights may be small - perhaps only a few m or 10 s of m across - such observations will require a future Io-dedicated mission that will obtain high spatial resolution (lava fountains or roiling lava lakes, where accurate determination of surface temperature distribution requires simultaneous or near-simultaneous (< 0.1 s) observations at different wavelengths, skylight thermal emission data are superior for the purposes of temperature derivation, as emission is stable on much longer time scales (minutes, or longer), so long as viewing geometry does not greatly change during that time.

  5. The structural stability of lunar lava tubes

    Science.gov (United States)

    Blair, David M.; Chappaz, Loic; Sood, Rohan; Milbury, Colleen; Bobet, Antonio; Melosh, H. Jay; Howell, Kathleen C.; Freed, Andrew M.

    2017-01-01

    Mounting evidence from the SELENE, LRO, and GRAIL spacecraft suggests the presence of vacant lava tubes under the surface of the Moon. GRAIL evidence, in particular, suggests that some may be more than a kilometer in width. Such large sublunarean structures would be of great benefit to future human exploration of the Moon, providing shelter from the harsh environment at the surface-but could empty lava tubes of this size be stable under lunar conditions? And what is the largest size at which they could remain structurally sound? We address these questions by creating elasto-plastic finite element models of lava tubes using the Abaqus modeling software and examining where there is local material failure in the tube's roof. We assess the strength of the rock body using the Geological Strength Index method with values appropriate to the Moon, assign it a basaltic density derived from a modern re-analysis of lunar samples, and assume a 3:1 width-to-height ratio for the lava tube. Our results show that the stability of a lava tube depends on its width, its roof thickness, and whether the rock comprising the structure begins in a lithostatic or Poisson stress state. With a roof 2 m thick, lava tubes a kilometer or more in width can remain stable, supporting inferences from GRAIL observations. The theoretical maximum size of a lunar lava tube depends on a variety of factors, but given sufficient burial depth (500 m) and an initial lithostatic stress state, our results show that lava tubes up to 5 km wide may be able to remain structurally stable.

  6. Does the Cave Environment Reduce Functional Diversity?

    Science.gov (United States)

    Fernandes, Camile Sorbo; Batalha, Marco Antonio; Bichuette, Maria Elina

    2016-01-01

    Caves are not colonised by all taxa present in the surface species pool, due to absence of light and the tendency to food limitation when compared to surface communities. Under strong species sorting during colonisation and later by the restrictive environmental filter, traits that are not adaptive in subterranean habitats may be filtered out. We tested whether cave communities were assembled by the restrictive regime propitiated by permanent darkness or by competitive exclusion due to resource scarcity. When compared to surface communities, the restrictive subterranean regime would lead to lower functional diversity and phenotypic clustering inside the caves, and the opposite should be expected in the case of competitive exclusion. Using isopods (Oniscidea) as model taxa, we measured several niche descriptors of taxa from surface and cave habitats, used a multivariate measure of functional diversity, and compared their widths. We found phenotypic overdispersion and higher functional diversity in cave taxa when compared to surface taxa. On the one hand, the dry climate outside of caves hampered the survival of several taxa and their ecological strategies, not viable under severe desiccation risk, culminating in the clustering of functional traits. In contrast, this restriction does not occur inside of caves, where isopods find favourable conditions under lower predation pressures and more amenable environmental parameters that allow occupation and subsequent diversification. Our results showed that, at least for some taxa, caves may not be such a harsh environment as previously thought. The high functional diversity we found inside caves adds an additional reason for the conservation of these sensitive environments.

  7. ACCESS Mars: A Mission Architecture for an initial settlement on Mars; using caves as habitation

    Science.gov (United States)

    Perez-Poch, Antoni; Gallardo, Beatriz; Laufer, Ren; Zavaleta, Jhony; Davila, Alfonso; de Carufel, Guy; Antonakopoulos, Konstantinos; Husseini, A. Al; Alvarez Sánchez, L.; Antonakopoulos, K.; Apeldoorn, J.; Ashford, K., Jr.; Atabay, D.; Barrios, I.; Baydaroglu, Y.; Bennell, K. M.; Chen, J.; Chen, X.; Cormier, D.; Crowley, P.; de Carufel, G.; Deper, B.; Drube, L.; Duffy, P.; Edwards, P.; Gutiérrez Fernandez, E.; Haider, O.; Kumar, G.; Henselowsky, C.; Hirano, D.; Hirmer, T.; Hogan, B.; Albalat, A. Jaime; Jens, E.; Jivenescu, I.; Jojaghaian, A.; Kerrigan, M.; Kodachi, Y.; Langston, S.; Macintosh, R.; Miguélez, X.; Panek, N.; Pegg, C.; Peldszus, R.; Peng, X.; Perez-Poch, A.; Perron, A.; Qiu, J.; Renten, P.; Ricardo, J.; Saraceno, T.; Sauceda, F.; Shaghaghi Varzeghani, A.; Shimmin, R.; Solaz, R.; Solé, A.; Suresh, E. R.; Mar Vaquero Escribano, T.; Vargas Muñoz, M.; Vaujour, P. D.; Zeile, D. Veilette, Y. Winetraub, O.

    This paper summarizes a team project report produced during the Summer Space Program of the International Space University, held at Nasa-Ames Research Center (CA, USA) by 56 students from 15 countries. Chair of the team project was Rene Laufer. Facilitators were Alfonso Davila and Jhonny Zavaleta, and teacher associate supporting the team was Beatriz Gallardo. The human race has evolved, grown and expanded through the exploration of Earth. After initial steps on the Moon, our next challenge is to explore the solar system. Mars shows potential for both scientific discovery and future human settlement, and therefore represents a prime candidate for the next leap of human exploration. Such a bold endeavor will be a driver for an unprecedented worldwide cooperative effort and the catalyst for a new era of international, intercultural and interdisciplinary human relations. Scientific and technological progress will also accelerate as mankind is ushered into a new era of space exploration. Currently proposed Mars missions have identified a number of challenges such as high levels of radiation, harsh climate and limited launch windows. Recently discovered lava tubes on Mars present potential solutions to some of these issues, but raise a variety of intriguing new challenges. This paper reviews existing reference missions and identifies areas of further research essential for adapting mission architectures to utilize caves. Different mission scenarios are proposed and analyzed, with a number of different recommendations given. An analysis of the feasibility of using Martian lava tubes as habitation is given in another paper by the same authors at COSPAR 2010 F34 Technical Session. Literature suggests a low radiation environment within Martian caves, allowing for extended duration missions. The ACCESS Mars Team concludes that the use of lava tubes as human habitats will be more beneficial for human Mars exploration than currently proposed surface solutions.

  8. Mineral resources of the Devil's Garden Lava Bed, Squaw Ridge Lava Bed, and Four Craters Lava Bed Wilderness Study Areas, Lake County, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Keith, W.J.; King, H.D.; Gettings, M.E. (Geological Survey, Reston, VA (USA)); Johnson, F.L. (US Bureau of Mines (US))

    1988-01-01

    The Devel's Garden lava Bed, Squaw Ridge Lava Bed, and Four Craters Lava Bed Wilderness Study Areas include approximately 70,940 acres and are underlain entirely by Pleistocene or Holocene lava flows and associated sediments. There is no evidence of hydrothermal alteration in the study areas. No resources were identified in the study areas, but there is low potential for perlite resources in the southern part of the Devil's Garden Lava Bed and the northern half of the Squaw Ridge Lava Bed areas. All three study areas have low potential for geothermal resources and for oil and gas resources.

  9. Fungal outbreak in a show cave.

    Science.gov (United States)

    Jurado, V; Porca, E; Cuezva, S; Fernandez-Cortes, A; Sanchez-Moral, S; Saiz-Jimenez, C

    2010-08-01

    Castañar de Ibor Cave (Spain) was discovered in 1967 and declared a Natural Monument in 1997. In 2003 the cave was opened to public visits. Despite of extensive control, on 26 August 2008 the cave walls and sediments appeared colonized by long, white fungal mycelia. This event was the result of an accidental input of detritus on the afternoon of 24 August 2008. We report here a fungal outbreak initiated by Mucor circinelloides and Fusarium solani and the methods used to control it.

  10. Bilateral Meckel's cave amyloidoma: a case report.

    Science.gov (United States)

    Gültaşli, N; van den Hauwe, L; Bruneau, M; D'Haene, N; Delpierre, I; Balériaux, D

    2012-05-01

    Primary solitary amyloidoma of Meckel's cave is rare, and a bilateral location is even more rare. To the best of our knowledge, only 12 cases in the literature have described such a primary lesion, including one case of bilateral involvement of Meckel's cave. We report here on the case of a 57-year-old woman presenting with pseudotumor masses involving both Meckel's caves and responsible for trigeminal neuropathy. The final diagnosis of amyloidoma was made on the basis of histological examination of surgical biopsy specimens.

  11. Bacterial community survey of sediments at Naracoorte Caves, Australia

    Directory of Open Access Journals (Sweden)

    Ball Andrew S.

    2012-07-01

    Full Text Available Bacterial diversity in sediments at UNESCO World Heritage listed Naracoorte Caves was surveyed as part of an investigation carried out in a larger study on assessing microbial communities in caves. Cave selection was based on tourist accessibility; Stick Tomato and Alexandra Cave (> 15000 annual visits and Strawhaven Cave was used as control (no tourist access. Microbial analysis showed that Bacillus was the most commonly detected microbial genus by culture dependent and independent survey of tourist accessible and inaccessible areas of show (tourist accessible and control caves. Other detected sediment bacterial groups were assigned to the Firmicutes, Actinobacteria and Proteobacteria. The survey also showed differences in bacterial diversity in caves with human access compared to the control cave with the control cave having unique microbial sequences (Acinetobacter, Agromyces, Micrococcus and Streptomyces. The show caves had higher bacterial counts, different 16S rDNA based DGGE cluster patterns and principal component groupings compared to Strawhaven. Different factors such as human access, cave use and configurations could have been responsible for the differences observed in the bacterial community cluster patterns (tourist accessible and inaccessible areas of these caves. Cave sediments can therefore act as reservoirs of microorganisms. This might have some implications on cave conservation activities especially if these sediments harbor rock art degrading microorganisms in caves with rock art.

  12. An Investigation of Meromixis in Cave Pools, Lechuguilla Cave, New Mexico.

    OpenAIRE

    David B. Levy

    2008-01-01

    Chemical characteristics of permanent stratification in cave pools (meromixis) may provide insight into the geochemical origin and evolution of cave pool waters. The objective of this study was to test the hypothesis that some pools in Lechuguilla Cave may be subject to ectogenic meromixis, where permanent chemical stratification is induced by input of relatively saline or fresh water from an external source. However, because organic C concentrations in Lechuguilla waters are low (typically...

  13. Physical volcanology of a voluminous rhyolite lava flow: The Badlands lava, Owyhee Plateau, southwestern Idaho

    Science.gov (United States)

    Manley, Curtis R.

    1996-05-01

    This paper describes an extraordinarily well preserved example of a large, high-SiO 2 rhyolite unit that by its exposed physical features can be demonstrated to be an effusive lava flow, not a rheomorphic ignimbrite. The Badlands lava flow of southwestern Idaho shows a multi-lobate form, with flow lobes that advanced along several azimuths from a long fissure vent. The lava flowed around one of its tephra ridges and a bedrock topographic high, creating a kipuka in the middle of the flow; the other tephra ridge was shoved aside by the lava. The lava itself is everywhere flow foliated, with foliation horizontal at the base, steepening toward the top, and convex in the direction of flow advance. The foliation parallels the margins of the flow lobes and reveals the position and orientation of the vent. Many samples of the lava flow's dense upper vitrophyre show one or more fragmental textures that formed by the settling of pumiceous and glassy debris into open fractures and the debris' subsequent welding into a rock that in many respects resembles welded tuff. By this process, the lava flow mimics an ignimbrite at the scale of an outcrop or thin section. Identical textures in other units have been cited as indicative of ash-flow emplacement mechanisms. The Badlands eruption tapped a stratified magma chamber, in which a large volume of phenocryst-rich (30 vol.%) magma underlay a small volume of magma more evolved and nearly aphyric. The lava flow shows mingling relations between the two magmas, with minor volumes of the aphyric magma occurring as early, small lava lobes and as individual layers in the dominant phenocryst-rich lava. Effusion of the 15 km 3 of rhyolite lava may have continued for as short as 6 or as long as 16 years, with effusion rates comparable to those observed at the Mount St. Helens dome. The Badlands lava had a pre-eruptive volatile content of about 2.75 wt.% H 2O or less, and erupted at approximately 830 °C, much lower than the temperatures of

  14. Early development of fern gametophytes in microgravity

    Science.gov (United States)

    Roux, Stanley J.; Chatterjee, Ani; Hillier, Sheila; Cannon, Tom

    2003-01-01

    Dormant spores of the fern Ceratopteris richardii were flown on Shuttle mission STS-93 to evaluate the effects of micro-g on their development and on their pattern of gene expression. Prior to flight the spores were sterilized and sown into one of two environments: (1) Microscope slides in a video-microscopy module; and (2) Petri dishes. All spores were then stored in darkness until use. Spore germination was initiated on orbit after exposure to light. For the spores on microscope slides, cell level changes were recorded through the clear spore coat of the spores by video microscopy. After their exposure to light, spores in petri dishes were frozen in orbit at four different time points during which on earth gravity fixes the polarity of their development. Spores were then stored frozen in Biological Research in Canister units until recovery on earth. The RNAs from these cells and from 1-g control cells were extracted and analyzed on earth after flight to assay changes in gene expression. Video microscopy results revealed that the germinated spores developed normally in microgravity, although the polarity of their development, which is guided by gravity on earth, was random in space. Differential Display-PCR analyses of RNA extracted from space-flown cells showed that there was about a 5% change in the pattern of gene expression between cells developing in micro-g compared to those developing on earth. c2002 Published by Elsevier Science Ltd on behalf of COSPAR.

  15. Early development of fern gametophytes in microgravity

    Science.gov (United States)

    Roux, Stanley J.; Chatterjee, Ani; Hillier, Sheila; Cannon, Tom

    Dormant spores of the fern Ceratopteris richardii were flown on Shuttle mission STS-93 to evaluate the effects of /micro-g on their development and on their pattern of gene expression. Prior to flight the spores were sterilized and sown into one of two environments: (1) Microscope slides in a video-microscopy module; and (2) Petri dishes. All spores were then stored in darkness until use. Spore germination was initiated on orbit after exposure to light. For the spores on microscope slides, cell level changes were recorded through the clear spore coat of the spores by video microscopy. After their exposure to light, spores in petri dishes were frozen in orbit at four different time points during which on earth gravity fixes the polarity of their development. Spores were then stored frozen in Biological Research in Canister units until recovery on earth. The RNAs from these cells and from /1-g control cells were extracted and analyzed on earth after flight to assay changes in gene expression. Video microscopy results revealed that the germinated spores developed normally in microgravity, although the polarity of their development, which is guided by gravity on earth, was random in space. Differential Display-PCR analyses of RNA extracted from space-flown cells showed that there was about a 5% change in the pattern of gene expression between cells developing in /micro-g compared to those developing on earth.

  16. Reconstructed tree fern Alethopteris zeilleri (Carboniferous, Medullosales)

    Energy Technology Data Exchange (ETDEWEB)

    Zodrow, Erwin L. [Department of Earth Sciences, University College of Cape Breton, Sydney, Nova, Scotia (Canada B1P 6L2)

    2007-01-02

    From a smaller open-pit area in the roof shale of the basal Cantabrian coal seam in Sydney Coalfield, Cape Breton Island, Nova Scotia, Canada, large amounts of the pteridosperm foliage Alethopteris zeilleri (Ragot) were found. This foliage is associated with abundant, naked medullosalean axes and dichotomies of varying sizes, up to 0.80-m long, cauline structures 0.90 m and 1.3 m long, detached ovules assigned to Pachytesta incrassata Brongniart, rare male-pollen organs of the type Dolerotheca Halle, rooted tree ferns in life position, and one specimen each of a juvenile medullosalean frond and root mantle. The fossils are compression/impression-preserved, and the foliage yielded thickly cutinized cuticles with unoriented cells (57-103 by 27-57 {mu}m) in intercostal fields. Ultimate rachises, and abaxial surfaces (excluding costal fields) show a mixture of simple and complexly-branched trichomes, and two different structural bases. These, together with fractal dimensionality of curvatures of anticlinal walls in intercostal fields, have taxonomic potential for alethopterids. The finds suggest reconstructing A. zeilleri (Ragot) as a tree, 5-7 m high, that bore both P. incrassata Brongniart and Dolerotheca-type fructifications. Its habitat was low-land coastal plains in the Pennsylvanian coal swamps of ancestral Sydney Coalfield. (author)

  17. Flood lavas on Earth, Io and Mars

    Science.gov (United States)

    Keszthelyi, L.; Self, S.; Thordarson, T.

    2006-01-01

    Flood lavas are major geological features on all the major rocky planetary bodies. They provide important insight into the dynamics and chemistry of the interior of these bodies. On the Earth, they appear to be associated with major and mass extinction events. It is therefore not surprising that there has been significant research on flood lavas in recent years. Initial models suggested eruption durations of days and volumetric fluxes of order 107 m3 s-1 with flows moving as turbulent floods. However, our understanding of how lava flows can be emplaced under an insulating crust was revolutionized by the observations of actively inflating pahoehoe flows in Hawaii. These new ideas led to the hypothesis that flood lavas were emplaced over many years with eruption rates of the order of 104 m3 s-1. The field evidence indicates that flood lava flows in the Columbia River Basalts, Deccan Traps, Etendeka lavas, and the Kerguelen Plateau were emplaced as inflated pahoehoe sheet flows. This was reinforced by the observation of active lava flows of ??? 100 km length on Io being formed as tube-fed flow fed by moderate eruption rates (102-103 m3 s-1). More recently it has been found that some flood lavas are also emplaced in a more rapid manner. New high-resolution images from Mars revealed 'platy-ridged' flood lava flows, named after the large rafted plates and ridges formed by compression of the flow top. A search for appropriate terrestrial analogues found an excellent example in Iceland: the 1783-1784 Laki Flow Field. The brecciated Laki flow top consists of pieces of pahoehoe, not aa clinker, leading us to call this 'rubbly pahoehoe'. Similar flows have been found in the Columbia River Basalts and the Kerguelen Plateau. We hypothesize that these flows form with a thick, insulating, but mobile crust, which is disrupted when surges in the erupted flux are too large to maintain the normal pahoehoe mode of emplacement Flood lavas emplaced in this manner could have

  18. Involvement of allelopathy in the formation of monospecific colonies of ferns.

    Science.gov (United States)

    Kato-Noguchi, Hisashi

    2015-05-01

    Some fern species often dominate plant communities by forming large monospecific colonies. However, the potential mechanism for this domination of the ferns remains obscure. Many plants secrete a wide range of compounds into the rhizosphere and change the chemical and physical properties of the rhizosphere soil. Through the secretion of compounds, such as allelopathic substances, plants inhibit the germination and growth of neighboring plants to compete more effectively for the resources. Ferns contain a variety of secondary metabolites and some of those compounds are released from the ferns into the rhizosphere soil, either as exudates from living ferns or by decomposition of fern residues in sufficient quantities to affect the germination and growth of neighboring plants as allelopathic substances. Therefore, allelopathic chemical interaction of the ferns with neighboring plants may play an important role in the formation of the monospecific colonies of the ferns.

  19. PERISCOPE: PERIapsis Subsurface Cave OPtical Explorer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Lunar sub-surface exploration has been a topic of discussion since the Lunar Reconnaissance Orbiter identified openings (cave skylights) on the surface of the moon...

  20. High resolution CT of Meckel's cave.

    Science.gov (United States)

    Chui, M; Tucker, W; Hudson, A; Bayer, N

    1985-01-01

    High resolution CT of the parasellar region was carried out in 50 patients studied for suspected pituitary microadenoma, but who showed normal pituitary gland or microadenoma on CT. This control group of patients all showed an ellipsoid low-density area in the posterior parasellar region. Knowledge of the gross anatomy and correlation with metrizamide cisternography suggest that the low density region represents Meckel's cave, rather than just the trigeminal ganglion alone. Though there is considerable variation in the size of Meckel's cave in different patients as well as the two sides of the same patient, the rather constant ellipsoid configuration of the cave in normal subjects will aid in diagnosing small pathological lesions, thereby obviating more invasive cisternography via the transovale or lumbar route. Patients with "idiopathic" tic douloureux do not show a Meckel's cave significantly different from the control group.

  1. Adult peripheral neuroepithelioma in Meckel's cave.

    Science.gov (United States)

    Midroni, G; Dhanani, A N; Gray, T; Tucker, W S; Bilbao, J M

    1991-02-01

    A case of peripheral neuroepithelioma arising from the trigeminal nerve in Meckel's cave is presented. The discussion emphasizes the pathological criteria for the diagnosis of a peripheral neuroepithelioma and the current controversy about the classification of this and related tumors.

  2. Towards resolving the complete fern tree of life.

    Directory of Open Access Journals (Sweden)

    Samuli Lehtonen

    Full Text Available In the past two decades, molecular systematic studies have revolutionized our understanding of the evolutionary history of ferns. The availability of large molecular data sets together with efficient computer algorithms, now enables us to reconstruct evolutionary histories with previously unseen completeness. Here, the most comprehensive fern phylogeny to date, representing over one-fifth of the extant global fern diversity, is inferred based on four plastid genes. Parsimony and maximum-likelihood analyses provided a mostly congruent results and in general supported the prevailing view on the higher-level fern systematics. At a deep phylogenetic level, the position of horsetails depended on the optimality criteria chosen, with horsetails positioned as the sister group either of Marattiopsida-Polypodiopsida clade or of the Polypodiopsida. The analyses demonstrate the power of using a 'supermatrix' approach to resolve large-scale phylogenies and reveal questionable taxonomies. These results provide a valuable background for future research on fern systematics, ecology, biogeography and other evolutionary studies.

  3. Nicotinamide metabolism in ferns: formation of nicotinic acid glucoside.

    Science.gov (United States)

    Ashihara, Hiroshi; Yin, Yuling; Watanabe, Shin

    2011-03-01

    The metabolic fate of [carbonyl-(14)C]nicotinamide was investigated in 9 fern species, Psilotum nudum, Angiopteris evecta, Lygodium japonicum, Acrostichum aureum, Asplenium antiquum, Diplazium subsinuatum, Thelypteris acuminate, Blechnum orientale and Crytomium fortune. All fern species produce a large quantity of nicotinic acid glucoside from [(14)C]nicotinamide, but trigonelline formation is very low. Increases in the release of (14)CO(2) with incubation time was accompanied by decreases in [carboxyl-(14)C]nicotinic acid glucoside. There was slight stimulation of nicotinic acid glucoside formation by 250 mM NaCl in mature leaves of the mangrove fern, Acrostichum aureum, but it is unlikely that this compound acts as a compatible solute. Nicotinamide and nicotinic acid salvage for pyridine nucleotide synthesis was detected in all fern species, although this activity was always less than nicotinic acid glucoside synthesis. Predominant formation of nicotinic acid glucoside is characteristic of nicotinic acid metabolism in ferns. This reaction appears to act as a detoxication mechanism, removing excess nicotinic acid.

  4. Tree-mould caves in Slovakia.

    Directory of Open Access Journals (Sweden)

    Gaal Ludovit

    2003-01-01

    Full Text Available Four tube-shaped caves are described in this work, which origined in consequence of weathering the trees. Their length ranges from 5.8 to 17 m. All of them occur in neovolcanic rocks of Middle Slovakia, in epiclastic andesite conglomerates, breccias or in the tuffs. Some other caverns are close to the entrance of this caves, however they are inaccessible for a man. Thin rim of silicates (opal or chalcedony occurs in some of them.

  5. Hypogene caves of the central Appalachian Shenandoah Valley in Virginia

    Science.gov (United States)

    Doctor, Daniel H.; Orndorff, Wil

    2017-01-01

    Several caves in the Shenandoah Valley in Virginia show evidence for early hypogenic conduit development with later-enhanced solution under partly confined phreatic conditions guided by geologic structures. Many (but not all) of these caves have been subsequently invaded by surface waters as a result of erosion and exhumation. Those not so affected are relict phreatic caves, bearing no relation to modern drainage patterns. Field and petrographic evidence shows that carbonate rocks hosting certain relict phreatic caves were dolomitized and/or silicified by early hydrothermal fluid migration in zones that served to locally enhance rock porosity, thus providing preferential pathways for later solution by groundwater flow, and making the surrounding bedrock more resistant to surficial weathering to result in caves that reside within isolated hills on the land surface. Features suggesting that deep phreatic processes dominated the development of these relict caves include (1) cave passage morphologies indicative of ascending fluids, (2) cave plans of irregular pattern, reflecting early maze or anastomosing development, (3) a general lack of cave breakdown and cave streams or cave stream deposits, and (4) calcite wall and pool coatings within isolated caves intersecting the local water table, and within unroofed caves at topographic locations elevated well above the local base level. Episodes of deep karstification were likely separated by long periods of geologic time, encompassing multiple phases of sedimentary fill and excavation within caves, and reflect a complex history of deep fluid migration that set the stage for later shallow speleogenesis that continues today.

  6. Genomic sequencing of Pleistocene cave bears

    Energy Technology Data Exchange (ETDEWEB)

    Noonan, James P.; Hofreiter, Michael; Smith, Doug; Priest, JamesR.; Rohland, Nadin; Rabeder, Gernot; Krause, Johannes; Detter, J. Chris; Paabo, Svante; Rubin, Edward M.

    2005-04-01

    Despite the information content of genomic DNA, ancient DNA studies to date have largely been limited to amplification of mitochondrial DNA due to technical hurdles such as contamination and degradation of ancient DNAs. In this study, we describe two metagenomic libraries constructed using unamplified DNA extracted from the bones of two 40,000-year-old extinct cave bears. Analysis of {approx}1 Mb of sequence from each library showed that, despite significant microbial contamination, 5.8 percent and 1.1 percent of clones in the libraries contain cave bear inserts, yielding 26,861 bp of cave bear genome sequence. Alignment of this sequence to the dog genome, the closest sequenced genome to cave bear in terms of evolutionary distance, revealed roughly the expected ratio of cave bear exons, repeats and conserved noncoding sequences. Only 0.04 percent of all clones sequenced were derived from contamination with modern human DNA. Comparison of cave bear with orthologous sequences from several modern bear species revealed the evolutionary relationship of these lineages. Using the metagenomic approach described here, we have recovered substantial quantities of mammalian genomic sequence more than twice as old as any previously reported, establishing the feasibility of ancient DNA genomic sequencing programs.

  7. Airborne microorganisms in Lascaux Cave (France

    Directory of Open Access Journals (Sweden)

    Pedro M Martin-Sanchez

    2014-09-01

    Full Text Available Lascaux Cave in France contains valuable Palaeolithic paintings. The importance of the paintings, one of the finest examples of European rock art paintings, was recognized shortly after their discovery in 1940. In the 60’s of the past century the cave received a huge number of visitors and suffered a microbial crisis due to the impact of massive tourism and the previous adaptation works carried out to facilitate visits. In 1963, the cave was closed due to the damage produced by visitors’ breath, lighting and algal growth on the paintings. In 2001, an outbreak of the fungus Fusarium solani covered the walls and sediments. Later, black stains, produced by the growth of the fungus Ochroconis lascauxensis, appeared on the walls. In 2006, the extensive black stains constituted the third major microbial crisis. In an attempt to know the dispersion of microorganisms inside the cave, aerobiological and microclimate studies were carried out in two different seasons, when a climate system for preventing condensation of water vapor on the walls was active (September 2010 or inactive (February 2010. The data showed that in September the convection currents created by the climate system evacuated the airborne microorganisms whereas in February they remained in suspension which explained the high concentrations of bacteria and fungi found in the air. This double aerobiological and microclimate study inLascauxCave can help to understand the dispersion of microorganisms and to adopt measures for a correct cave management.

  8. FTIR and py-GC-MS spectra of true-fern and seed-fern sphenopterids (Sydney Coalfield, Nova Scotia, Canada, Pennsylvanian)

    Science.gov (United States)

    Zodrow, E.L.; Mastalerz, Maria

    2002-01-01

    Sphenopterid specimens from the Late Pennsylvanian of Sydney Coalfield, Canada, are investigated by FTIR and py-GC-MS techniques as part of an on-going research project into the biochemistry and chemotaxonomy of Pennsylvanian-age pteridophylls. Included in the investigation are samples of the true-fern species Oligocarpia brongniartii and Zeilleria delicatula that are preserved as naturally macerated cuticles (NMC), and the seed-fern Eusphenopteris neuropteroides that is also preserved as a compression/impression. FTIR spectra of NMC seed-fern E. neuropteroides, and fern sphenopterid O. brongniartii are very similar, except that the latter does not have aromatic bands in the 700-900 cm-1 out-of-plane region, py-GC-MS show more aromatic compounds for the seed fern than for the two true-fern sphenopterids. Another difference between seed-fern and true-fern sphenopterids is a lower ratio of CH2 to CH3 in chemically treated specimens (CTC) for the seed fern. These observations suggest slightly higher aromaticity for the seed ferns, perhaps related to some chemotaxonomic differences. Comparison of FTIR and py-GC-MS characteristics of sphenopterids and other plant groups shows that these two techniques have potential to identifying chemotaxonomic signals from Carboniferous pteridophylls in general, although more data are needed to confirm this. ?? 2002 Elsevier Science B.V. All rights reserved.

  9. Nornahraun lava morphology and mode of emplacement

    Science.gov (United States)

    Pedersen, Gro B. M.; Höskuldsson, Armann; Riishuus, Morten S.; Jónsdóttir, Ingibjörg; Gudmundsson, Magnús T.; Sigmundsson, Freysteinn; Óskarsson, Birgir V.; Drouin, Vincent; Gallagher, Catherine; Askew, Rob; Moreland, William M.; Dürig, Tobias; Dumont, Stephanie; Þórdarson, Þór

    2015-04-01

    The ongoing Nornahraun eruption is the largest effusive eruption in Iceland since the Laki eruption in 1783-84, with an estimated lava volume of ~1.15 km3 covering an area of ~83.4 km2 (as of 5 JAN 2015). The eruption provides an unprecedented opportunity to study i) lava morphologies and their emplacement styles, ii) the transition from from open to closed lava pathways and iii) lava pond formation. Tracking of the lava advancement and morphology has been performed by GPS and GoPro cameras installed in 4×4 vehicles as well as video footage. Complimentary observations have been provided from aircraft platforms and by satellite data. Of particular importance for lava morphology observations are 1-12 m/pixel airborne SAR images (x-band). The Nornahraun flow field comprises a continuum of morphologies from pāhoehoe to 'a'ā, which have varied tem-porally and spatially. At the onset of the eruption 31 AUG, lava flows advanced rapidly (400-800 m/hr) from the 1.5 km long fissure as large slabby pāhoehoe [1-3] sheet lobes, 100-500 m wide and 0.3-1 m thick at the flow fronts. By 1 SEPT, the flows began channeling towards the NE constrained by the older Holuhraun I lava field and the to-pography of flood plain itself. A central open channel developed, feeding a 1-2 km wide active 'a'ā frontal lobe that advanced 1-2 km/day. In addition to its own caterpillar motion, the frontal lobe advanced in a series of 30-50 m long breakouts, predominantly slabby and rubbly pāhoehoe [4,5]. These breakouts had initial velocities of 10-30 m/hr and reached their full length within tens of minutes and subsequently inflated over hours. With the continuous advancement of the 'a'ā flow front, the breakouts were incorporated into the 'a'ā flow fronts and seldom preserved. At the margins of the frontal lava lobe, the breakouts were more sporadic, but predominantly rubbly pāhoehoe and slabby pāhoehoe, as at the flow front. The lava flow advanced ENE into Jökulsá á Fjöllum on 7 SEPT

  10. Mafic-crystal distributions, viscosities, and lava structures of some Hawaiian lava flows

    Science.gov (United States)

    Rowland, Scott K.; Walker, George P. L.

    1988-09-01

    The distribution patterns of mafic phenocrysts in some Hawaiian basalt flows are consistent with simple in situ gravitational settling. We use the patterns to estimate the crystal settling velocity and hence viscosity of the lava, which in turn can be correlated with surface structures. Numerical modeling generates theoretical crystal concentration profiles through lava flow units of different thicknesses for differing settling velocities. By fitting these curves to field data, crystal-settling rates through the lavas can be estimated, from which the viscosities of the flows can be determined using Stokes' Law. Lavas in which the crystal settling velocity was relatively high (on the order of 5 × 10 -4 cm/sec) show great variations in phenocryst content, both from top to bottom of the same flow unit, and from one flow unit to another. Such lava is invariably pahoehoe, flow units of which are usually less than 1 m thick. Lavas in which the crystal-settling velocity was low show a small but measurable variation in phenocryst content. These lavas are part of a progression from a rough pahoehoe to toothpaste lava to a'a. Toothpaste lava is characterized by spiny texture as well as the ability to retain surface grooves during solidification, and flow units are usually thicker than 1 m. In the thickest of Hawaiian a'a flows, those of the distal type, no systematic crystal variations are observed, and high viscosity coupled with a finite yield strength prevented crystal settling. The amount of crystal settling in pahoehoe indicates that the viscosity ranged from 600 to 6000 Pa s. The limited amount of settling in toothpaste lava indicates a viscosity greater than this value, approaching 12,000 Pa s. We infer that distal-type a'a had a higher viscosity still and also possessed a yield strength.

  11. Gene transfer from a parasitic flowering plant to a fern.

    Science.gov (United States)

    Davis, Charles C; Anderson, William R; Wurdack, Kenneth J

    2005-11-07

    The rattlesnake fern (Botrychium virginianum (L.) Sw.) is obligately mycotrophic and widely distributed across the northern hemisphere. Three mitochondrial gene regions place this species with other ferns in Ophioglossaceae, while two regions place it as a member of the largely parasitic angiosperm order Santalales (sandalwoods and mistletoes). These discordant phylogenetic placements suggest that part of the genome in B. virginianum was acquired by horizontal gene transfer (HGT), perhaps from root-parasitic Loranthaceae. These transgenes are restricted to B. virginianum and occur across the range of the species. Molecular and life-history traits indicate that the transfer preceded the global expansion of B. virginianum, and that the latter may have happened very rapidly. This is the first report of HGT from an angiosperm to a fern, through either direct parasitism or the mediation of interconnecting fungal symbionts.

  12. Environmental Fate and Analysis of Ptaquiloside from the Bracken Fern

    DEFF Research Database (Denmark)

    Clauson-Kaas, Frederik

    The naturally occurring phytotoxin ptaquiloside (PTA) has long been known to be both acute toxic and carcinogenic. Contents of more than 1% ptaquiloside on dry weight has been detected in bracken (Pteridium spp.), a fern distributed across the globe in often dense populations. This work focused...... fronds (the leaves of ferns) in concentrations up to 169 µ/L during rainfall events. Rainfall further determined the concentration in a stream that drained a bracken-covered catchment, suggesting that this is a potent driver of ptaquiloside exposure in the environment. In both pure and natural waters, p...

  13. Basics of lava-lamp convection

    Science.gov (United States)

    Gyüre, Balázs; Jánosi, Imre M.

    2009-10-01

    Laboratory experiments are reported in an immiscible two-fluid system, where thermal convection is initiated by heating at the bottom and cooling at the top. The lava-lamp regime is characterized by a robust periodic exchange process where warm blobs rise from the bottom, attach to the top surface for a while, then cold blobs sink down again. Immiscibility allows to reach real steady (dynamical equilibrium) states which can be sustained for several days. Two modes of lava-lamp convection could be identified by recording and evaluating temperature time series at the bottom and at the top of the container: a “slow” mode is determined by an effective heat transport speed at a given temperature gradient, while a second mode of constant periodicity is viscosity limited. Contrasting of laboratory and geophysical observations yields the conclusion that the frequently suggested lava-lamp analogy fails for the accepted models of mantle convection.

  14. The Mammoth Cave system, Kentucky, USA; El sistema de la Mammoth Cave, Kentucky, EE.UU

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, A. N.

    2016-07-01

    Mammoth Cave is the main attraction of Mammoth Cave National Park. For several decades it has been the longest known cave in the world and currently contains 652 km in 2016 of surveyed passages. It is located in the heart of an extensive karst plateau, in which the stratal dip averages only one degree. The cave is part of a drainage basin of more than 200 km{sup 2}. The cave has been known to local inhabitants for several millennia and contains a rich trove of archaeological and historical artifacts. It contains many speleo biota including several rare and endangered species and has been designated a World Heritage Site and an International Biosphere Reserve (UNESCO). Its many passage levels and sediments contain a record of the fluvial history of most of south-eastern North America. (Author)

  15. Studies of fluid instabilities in flows of lava and debris

    Science.gov (United States)

    Fink, Jonathan H.

    1987-01-01

    At least two instabilities have been identified and utilized in lava flow studies: surface folding and gravity instability. Both lead to the development of regularly spaced structures on the surfaces of lava flows. The geometry of surface folds have been used to estimate the rheology of lava flows on other planets. One investigation's analysis assumed that lava flows have a temperature-dependent Newtonian rheology, and that the lava's viscosity decreased exponentially inward from the upper surface. The author reviews studies by other investigators on the analysis of surface folding, the analysis of Taylor instability in lava flows, and the effect of surface folding on debris flows.

  16. The Payun-Matru lava field: a source of analogues for Martian long lava flows

    Science.gov (United States)

    Giacomini, L.; Pasquarè, G.; Massironi, M.; Frigeri, A.; Bistacchi, A.; Frederico, C.

    2007-08-01

    The Payun Matru Volcanic complex is a Quaternary fissural structure belonging to the back-arc extensional area of the Andes in the Mendoza Province (Argentina). The eastern portion of the volcanic structure is covered by a basaltic field of pahoehoe lava flows advanced over more than 180 km from the fissural feeding vents that are aligned with a E-W fault system (Carbonilla fault). Thanks to their widespread extension, these flows represent some of the largest lava flows in the world and the Pampas Onduladas flow can be considered the longest sub-aerial individual lava flow on the Earth surface [1,2]. These gigantic flows propagated over the nearly flat surface of the Pampean foreland, moving on a 0.3 degree slope. The very low viscosity of the olivine basalt lavas, coupled with the inflation process and an extensive system of lava tubes are the most probable explanation for their considerable length. The inflation process likely develop under a steady flow rate sustained for a long time [3]. A thin viscoelastic crust, built up at an early stage, is later inflated by the underlying fluid core, which remains hot and fluid thanks to the thermal-shield effect of the crust. The crust is progressively thickened by accretion from below and spreading is due to the continuous creation of new inflated lobes, which develop at the front of the flow. Certain morphological features are considered to be "fingerprints" of inflation [4, 5, 6]; these include tumuli, lava rises, lava lobes and ridges. All these morphologies are present in the more widespread Payun Matru lava flows that, where they form extensive sheetflows, can reach a maximum thickness of more than 20 meters. After the emplacement of the major flows, a second eruptive cycle involved the Payun Matru volcanic structure. During this stage thick and channelized flows of andesitic and dacitic lavas, accompanied the formation of two trachitic and trachiandesitic strato-volcanoes (Payun Matru and Payun Liso) culminated

  17. Habitat Management Plan for Logan Cave National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Logan Cave NWR Habitat Management Plan provides a long-term vision and specific guidance on managing habitats for the resources of concern at Logan Cave NWR, to...

  18. Groundwater Quality Monitoring at Logan Cave National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Proposal is to establish long-term groundwater parameters associated with the outflow from Logan Cave and the implication to the aquatic resources in the cave.

  19. Stability analysis of subgrade cave roofs in karst region

    Institute of Scientific and Technical Information of China (English)

    蒋冲; 赵明华; 曹文贵

    2008-01-01

    According to the engineering features of subgrade cave roof in karst region, the clamped beam model of subgrade cave roof in karst region was set up. Based on the catastrophe theory, the cusp catastrophe model for bearing capacity of subgrade cave roof and safe thickness of subgrade cave roof in karst region was established. The necessary instability conditions of subgrade cave roof were deduced, and then the methods to determine safe thickness of cave roofs under piles and bearing capacity of subgrade cave roof were proposed. At the same time, a practical engineering project was applied to verifying this method, which has been proved successfu1ly. At last, the major factors that affect the stability on cave roof under pile in karst region were deeply discussed and some results in quality were acquired.

  20. Reproductive Seasonality in Nesticus (Araneae: Nesticidae) Cave Spiders

    OpenAIRE

    Carver, Linnea M.; Perlaky, Patricia; Cressler, Alan; Kirk S Zigler

    2016-01-01

    Spiders of the family Nesticidae are members of cave communities around the world with cave-obligate (troglobiotic) species known from North America, Europe, Asia and the Indo-Pacific. A radiation of Nesticus (Araneae: Nesticidae) in the southern Appalachians includes ten troglobiotic species. Many of these species are of conservation interest due to their small ranges, with four species being single-cave endemics. Despite conservation concerns and their important role as predators in cave co...

  1. Using bioenergetic models to estimate environmental conditions in anchialine caves

    OpenAIRE

    Klanjšček, Tin; Cukrov, Neven; Cukrov, Marijana; Geček, Sunčana; Legović, Tarzan

    2012-01-01

    Ways of deducing information on physicochemical characteristics of anchialine caves from measurements of sedentary biota are investigated. First, photographs of Ficopomatus enigmaticus from two different anchialine caves are used to draw qualitative conclusions on water circulation patterns and organic loads of the two caves. Next, the ability of bioenergetic models to quantify average conditions in anchialine caves from information on abundance, distribution, morphological characteristcs, an...

  2. Environmental Fate and Analysis of Ptaquiloside from the Bracken Fern

    DEFF Research Database (Denmark)

    Clauson-Kaas, Frederik

    fronds (the leaves of ferns) in concentrations up to 169 µ/L during rainfall events. Rainfall further determined the concentration in a stream that drained a bracken-covered catchment, suggesting that this is a potent driver of ptaquiloside exposure in the environment. In both pure and natural waters, p...

  3. Gene silencing in a polyploid homosporous fern: paleopolyploidy revisited.

    OpenAIRE

    Gastony, G J

    1991-01-01

    Because of their high chromosome numbers, homosporous vascular plants were considered paleopolyploids until recent enzyme electrophoretic studies rejected this hypothesis by showing that they express only diploid numbers of isozymes. In polyploid sporophytes of the homosporous fern pelleae rufa, however, progressive diminution of phosphoglucoisomerase activities encoded by one ancestral genome culminates in tetraploid plants exhibiting a completely diploidized electrophoretic phenotype for th...

  4. Ferns and lycophytes of Pernambuco State, Brazil: Metaxyaceae

    Directory of Open Access Journals (Sweden)

    Iva Carneiro Leão Barros

    2010-09-01

    Full Text Available The present paper elucidates part of the fern flora of Pernambuco State. Metaxyaceae is native to the state and is represented by a single species, Metaxya rostrata (Kunth C. Presl. Descriptions and illustrations, as well as geographical distribution and habitats, are presented.

  5. Why are there so few species of ferns?

    Science.gov (United States)

    Ranker, Tom A; Sundue, Michael A

    2015-07-01

    A recent study has documented a natural hybridization event between two fern lineages that last shared a common ancestor about 60 million years ago. This is one of the deepest hybridization events ever described and has important implications for plant speciation theory.

  6. Instructions for collecting tree ferns of the family Cyatheaceae

    NARCIS (Netherlands)

    Holttum, R.E.

    1957-01-01

    The next monographic study which will be undertaken for the series Pteridophyta of the Flora Malesiana will be devoted to the tree ferns of the Cyatheaceae. In connection with the large size of these plants and the desirability of having more and complete material at our disposal, the following note

  7. Comparative morphology of the gametophyte of some Thelypteroid ferns

    NARCIS (Netherlands)

    Sen, Tuhinsri

    1981-01-01

    A study of the development of the gametophytes of sixteen thelypteroid ferns reveals similarities and significant differences among them. Combinations of the diversified features of the prothalli appear to have a tremendous impact on identification and delimitation of the major taxa, and support the

  8. Checklist of the Ferns, Natural Falls State Park

    Directory of Open Access Journals (Sweden)

    Smith, Bruce A.

    2001-12-01

    Full Text Available Natural Falls State Park, formerly known as Dripping Springs is located in northeast Oklahoma. The park's natural beauty and flora have attracted visitors since 1907. In a 1988 visit to the Oklahoma State University Herbarium, I noticed that several herbarium sheets of ferns were collected from Dripping Springs. This was intriguing and made me want to visit the area. Due to my interest in floristics and taxonomy, Natural Falls State Park seemed the perfect place to create a checklist of ferns. Thus, the objective of this study was to create an inventory of the ferns of Dripping Springs using my collection and the collections and observations from earlier botanists. A systematic collection of the ferns of Dripping Springs was conducted on August 7, 1998, October 15, 1998, and October 20, 2001. Using standard taxonomic methods, each plant was identified to species and subsequently inventoried. In three days of collecting, 17species from 6 families and 12 genera were encountered. Since 1925 a total of 19 species from 6 families and 12 genera have been reported to occur.

  9. New observations and synthesis of paleogene heterosporous water ferns

    NARCIS (Netherlands)

    Collinson, M.E.; Smith, S.Y.; van Konijnenburg-van Cittert, J.H.A.; Batten, D.J.; Refidaff, C.; Barke, J.; Marone, F.

    Premise of research. Reproductive structures of modern genera of heterosporous water ferns (Marsileaceae and Salviniaceae) are widespread and abundant in plant mesofossil assemblages from the Paleogene. For Salviniaceae, whole fertile fossil plants give a good understanding of morphology. These

  10. The omnipresent water fern Azolla caroliniana does not contain lignin

    NARCIS (Netherlands)

    Nierop, K.G.J.; Speelman, E.N.; Leeuw, J.W. de; Reichart, G.-J.

    2011-01-01

    Several studies have reported the presence of large amounts of lignin in ubiquitously occurring species of the freshwater fern Azolla. Molecular analysis using flash pyrolysis and thermally assisted hydrolysis and methylation shows, however, that neither the leaves nor the roots of Azolla contain

  11. Cave Tourism: The Potential of Asar Cave as a Natural Tourism Asset at Lenggong Valley, Perak

    Directory of Open Access Journals (Sweden)

    Rindam Main

    2014-01-01

    Full Text Available The Lenggong Valley, from a standpoint of natural tourism research, presents strengths, weaknesses, opportunities and challenges that can be utilized to help increase the opportunities for the local community to increase their standard of living. Asar Cave comprises one of the caves that are found in Lenggong. A series of external studies have been done on Asar Cave in order to measure its potential for natural tourism in Lenggong. The objective of this study is to discuss caves as a natural resource that has great potential in the growth of the economy of the residents of the Lenggong Valley. Marketing caves as a source of nature tourism helps the government’s achievements in National Key Result Areas, apart from being a form of environmental control as well as helping to increase awareness about environmental education, specifically those associated with caves. The research results find that SWOT analysis presents huge potential for caves to become a source of nature tourism development in Lenggong. Great potential can also be seen from a standpoint of increasing the standard of living of its residents through their involvement in the tourism sector based on local natural assets.

  12. Toothpaste lava: Characteristics and origin of a lava structural type transitional between pahoehoe and aa

    Science.gov (United States)

    Rowland, Scott K.; Walker, George P. L.

    1987-08-01

    Toothpaste lava, an important basalt structural type which illustrates the transition from pahoehoe to aa, is particularly well displayed on the 1960 Kapoho lava of Kilauea Volcano. Its transitional features stem from a viscosity higher than that of pahoehoe and a rate of flow slower than that of aa. Viscosity can be quantified by the limited settling of olivine phenocrysts and rate of flow by field observations related to the low-angle slope on which the lava flowed. Much can be learned about the viscosity, rheologic condition, and flow velocity of lavas long after solidification by analyses of their structural characteristics, and it is possible to make at least a semiquantitative assessment of the numerical values of these parameters.

  13. Final Critical Habitat for Kauai cave wolf spider (Adelocosa anops) and the Kauai cave amphipod (Spelaeorchestia koloana).

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify, in general, the areas of final critical habitat for Kauai cave wolf spider (Adelocosa anops) and the Kauai cave amphipod (Spelaeorchestia...

  14. Final Critical Habitat for Kauai cave wolf spider (Adelocosa anops) and the Kauai cave amphipod (Spelaeorchestia koloana).

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify, in general, the areas of final critical habitat for Kauai cave wolf spider (Adelocosa anops) and the Kauai cave amphipod (Spelaeorchestia...

  15. 75 FR 4417 - Wind Cave National Park, Custer County, SD

    Science.gov (United States)

    2010-01-27

    ... Wind Cave National Park, Custer County, SD AGENCY: National Park Service. ACTION: Notice of... Statement, Wind Cave National Park, Custer County, South Dakota. SUMMARY: Pursuant to Section 102(2)(C) of... Environmental Impact Statement (Plan), Wind Cave National Park, Custer County, South Dakota. On December 3,...

  16. Emplacing a cooling-limited rhyolite lava flow: similarities with basaltic lava flows

    Science.gov (United States)

    Magnall, Nathan; James, Mike R.; Tuffen, Hugh; Vye-Brown, Charlotte

    2017-06-01

    Accurate forecasts of lava flow length rely on estimates of eruption and magma properties and, potentially more challengingly, an understanding of the relative influence of characteristics such as the apparent viscosity, the yield strength of the flow core, or the strength of the surface crust. Consequently, even the most straightforward models of lava advance involve sufficient parameters that constraints can be relatively easily fitted within the uncertainties involved, at the expense of gaining insight. Here, for the first time, we incorporate morphological observations from during and after flow field evolution to improve model constraints and reduce uncertainties. After demonstrating the approach on a basaltic lava flow (Mt. Etna, 2001), we apply it to the 2011-12 Cordón Caulle rhyolite flow, where unprecedented observations and syn-emplacement satellite imagery of an advancing silica-rich lava flow have indicated an important crustal influence on flow emplacement. Our results show that an initial phase of viscosity-controlled advance at Cordón Caulle was followed by later crustal control, accompanied by formation of flow surface folds and large-scale crustal fractures. Where the lava was unconstrained by topography, the cooled crust ultimately halted advance of the main flow and led to the formation of breakouts from the flow front and margins, influencing the footprint of the lava, its advance rate, and the duration of flow advance. Highly similar behaviour occurred in the 2001 Etna basaltic lava flow. The processes controlling the advance of crystal-poor rhyolite and basaltic lava flow therefore appear similar, indicating common controlling mechanisms that transcend profound rheological and compositional differences.

  17. Burned and buried by the Siberian traps: tree trunks in volcaniclastics and lavas

    Science.gov (United States)

    Polozov, Alexander G.; Planke, Sverre; Svensen, Henrik H.; Jerram, Dougal A.; Looy, Cindy

    2017-04-01

    Major Phanerozoic mass extinctions could be explained by intense volcanic activity related to the formation of Large Igneous Provinces (LIPs). The Siberian Traps LIP possibly caused the most severe mass extinction on the Earth, the end-Permian extinction. This event is documented by global data showing the extinction of floral and faunal species and by stable isotope excursions. Information about the direct impact of the Siberian Traps on the local flora and fauna is scarce. By our knowledge, no detailed description has been done on the faith of trees in Siberia. However, the story of Late Permian giant trees like Cordaites and wood ferns, could shed light on the impact of the onset of the LIP magmatism and the related mass extinction. For the first time we describe that Late Permian tree trunks were buried in volcaniclastic deposits and at the footwall contact of the oldest lava flows of the Siberian Traps, and despite that this phenomenon is known by local geologists it is not well described in the literature. Tree trunks in volcaniclastic deposits were compressed during consolidation of the volcaniclastic material originated from pyroclastic density currents from nearby volcanic centers. Tree petrification is presented by quartz with minor sulphides, zeolite, calcite and sulphates. Tree trunks at the footwall contact of the lava flows have a better preserved year rings structure and late permineralization presented by calcite with minor quartz and sulphides. Our results demonstrate that intensive magmatic activity related with LIP formation affects land vegetation at various grades. Lavas have had a local violent impact, but burned and buried tree trunks have a better preserved structure reflecting single dominated permineralization processes than the tree trunks buried by pyroclastics that have covered extensive areas and followed by trees compression and later multistage permineralization. In a global context, such type of volcanic activity has a variable

  18. The Cave Exploration Group of East Africa and volcanic caves in Kenya

    Directory of Open Access Journals (Sweden)

    Michael Declan Kennedy

    1998-01-01

    Full Text Available This paper looks at the history of the Cave Exploration Group of East Africa with special reference to the exploration of volcanic caves. It demonstrates that the group has concentrated on two main areas, the Chyulu HiIls and Mt. Suswa, although other areas have also been studied. The Cave Exploration Group of East Africa has had to cope with various problems. The most important of which are related to the socio-economic conditions of a developing country. These problems have not prevented the group from making a valuable contribution to vulcanospeleology.

  19. Possible lava tube system in a hummocky lava flow at Daund, western Deccan Volcanic Province, India

    Indian Academy of Sciences (India)

    Raymond A Duraiswami; Ninad R Bondre; Gauri Dole

    2004-12-01

    A hummocky flow characterised by the presence of toes, lobes, tumuli and possible lava tube system is exposed near Daund, western Deccan Volcanic Province, India. The lava tube system is exposed as several exhumed outcrops and is composed of complex branching and discontinuous segments. The roof of the lava tube has collapsed but original lava tube walls and fragments of the tube roof are seen at numerous places along the tube. At some places the tube walls exhibit a single layer of lava lining, whereas, at other places it shows an additional layer characterised by smooth surface and polygonal cracks. The presence of a branching and meandering lava tube system in the Daund flow, which represents the terminal parts of Thakurwadi Formation, shows that the hummocky flow developed at a low local volumetric flow rate. This tube system developed in the thinner parts of the flow sequence; and tumuli developed in areas where the tube clogged temporarily in the sluggish flow.

  20. Is it always dark in caves?

    Directory of Open Access Journals (Sweden)

    Badino Giovanni

    2000-01-01

    Full Text Available Underground natural sources of visible light are considered. The main light producer is Cerenkov radiation emitted in air, water and rock by cosmic ray muons, that depends, in a complex way, on shape of mountain and of caves. In general the illumination increases linearly with the cavity dimensions. Other light sources are from secondary processes generated by radioactive decays in rock from minerals luminescence. The natural light fluxes in caves are in general easy to detect but are not used from underground life.

  1. Meckel's cave meningiomas with subarachnoid hemorrhage.

    Science.gov (United States)

    Rosenberg, G A; Herz, D A; Leeds, N; Strully, K

    1975-06-01

    Two patients with Meckel's Cave meningiomas were initially hospitalized as a result of subarachnoid hemorrhage. Four-vessel angiography was necessary to exclude other causes of bleeding while demonstrating these lesions. Apoplectic presentation in both cases led to early diagnosis and successful surgical therapy. A review of the literature reveals subarachnoid hemorrhage to be a rarity in association with meningiomas. The two patients currently reported are believed to be the only examples on record of hemorrhagic meningiomas arising from the region of Meckel's Cave.

  2. Dating Petroglyphs from Fugoppe Cave, Japan

    Directory of Open Access Journals (Sweden)

    Masaru Ogawa

    2014-01-01

    Full Text Available For over 20 years, I have tried to establish a relative date for petroglyphs in Fugoppe Cave, Japan. Unsuspected amidst debris accumulating from about 1300 years ago, the petroglyphs were rediscovered accidentally in 1950. From an analysis of petroglyphs on fallen rocks scattered randomly on the site floor, I argue that the artworks date from ca.1900 years ago. The cave itself, formed by wave action, saw its main occupation by pottery-making people from 1700–1500 years ago; although the petroglyphs on the rock walls predated their occupation, it seems unlikely that the occupants attached any meaning to them.

  3. The importance of ants in cave ecology, with new records and behavioral observations of ants in Arizona caves

    Directory of Open Access Journals (Sweden)

    Robert B. Pape

    2016-09-01

    Full Text Available The importance of ants as elements in cave ecology has been mostly unrecognized. A global list of ant species recorded from caves, compiled from a review of existing literature, is presented. This paper also reviews what is currently known about ants occurring in Arizona (USA caves. The diversity and distribution represented in these records suggests ants are relatively common cave visitors (trogloxenes. A general utilization of caves by ants within both temperate and tropical latitudes may be inferred from this combined evidence. Observations of ant behavior in Arizona caves demonstrate a low level and sporadic, but persistent, use of these habitats and their contained resources by individual ant colonies. Documentation of Neivamyrmex sp. preying on cave-inhabiting arthropods is reported here for the first time. Observations of hypogeic army ants in caves suggests they may not penetrate to great vertical depth in search of prey, but can be persistent occupants in relatively shallow, horizontal sections of caves where they may prey on endemic cave animals. First cave records for ten ant species are reported from Arizona caves. These include two species of Neivamyrmex (N. nigrescens Cresson and Neivamyrmex sp.; Formicidae: Dorylinae, four myrmicines (Pheidole portalensis Wilson, Pheidole cf. porcula Wheeler, Solenopsis aurea Wheeler and Stenamma sp. Westwood, one dolichoderine (Forelius keiferi Wheeler and three formicines (Lasius arizonicus Wheeler, L. sitiens Wilson, and Camponotus sp. Mayr.

  4. A 4000-species dataset provides new insight into the evolution of ferns.

    Science.gov (United States)

    Testo, Weston; Sundue, Michael

    2016-12-01

    Ferns are the second-most diverse lineage of vascular plants on Earth, yet the best-sampled time-calibrated phylogeny of the group to date includes fewer than 5% of global diversity and was published seven years ago. We present a time-calibrated phylogeny that includes nearly half of extant fern diversity. Our results are evaluated in the context of previous studies and the fossil record, and we develop new hypotheses about the radiation of leptosporangiate ferns. We used sequence data from six chloroplast regions for nearly 4000 species of ferns to generate the most comprehensive phylogeny of the group ever published. We calibrate the phylogeny with twenty-six fossils and use an array of phylogenetic methods to resolve phylogenetic relationships, estimate divergence times, and infer speciation, extinction, and net diversification rates. We infer a mid-late Silurian origin for ferns (including horsetails) and an early Carboniferous origin for leptosporangiate ferns. Most derived fern families appeared in the Cretaceous and persisted for millions of years before rapidly diversifying in the Cenozoic. We find no evidence of differential rates of diversification among terrestrial and epiphytic species. Our findings challenge previous hypotheses on the evolutionary history of ferns and present a new paradigm for their Cenozoic radiation. We estimate earlier divergences for most fern lineages than were reported in previous studies and provide evidence of extended persistence of major fern lineages prior to rapid diversification in the last fifty million years.

  5. Ice-Confined Basaltic Lava Flows: Review and Discussion

    Science.gov (United States)

    Skilling, I.; Edwards, B. R.

    2012-12-01

    Basaltic lavas that are interpreted as having been emplaced in subglacial or ice-confined subaerial settings are known from several localities in Iceland, British Columbia and Antarctica. At least four different types of observations have been used to date to identify emplacement of basaltic lavas in an ice-rich environment: i) gross flow morphology, ii) surface structures, iii) evidence for ice-confined water during emplacement, and iv) lava fracture patterns. Five types of ice-confined lava are identified: sheets, lobes, mounds, linear ridges and sinuous ridges. While the appearance of lavas is controlled by the same factors as in the submarine environment, such as the geometry and configuration of vents and lava tubes, flow rheology and rates, and underlying topography, the presence of ice can lead to distinct features that are specific to the ice-confined setting. Other types have very similar or identical equivalents in submarine environment, albeit with some oversteepening/ice contact surfaces. Ice-confined lavas can form as (1) subaerial or subaqueous lavas emplaced against ice open to the air, (2) subaqueous lavas emplaced into pre-existing sub-ice drainage networks, and (3) subaqueous lavas emplaced into ponded water beneath ice. Their surface structures reflect the relationship between rates of lava flow emplacement at the site of ice-water-lava contact, ice melting and water drainage. Variations in local lava flow rates could be due to lava cooling, constriction, inflation, tube development, ice melting, ice collapse, lava collapse, changes in eruption rate etc. Episodes of higher lava flow rate would favour direct ice contact and plastic compression against the ice, generating oversteepened and/or overthickened chilled margins, cavities in the lava formed by melting of enveloped ice blocks (cryolith cavities) and structures such as flattened pillows and lava clasts embedded into the glassy margins. Melting back of the confining ice generates space to

  6. Occurrence and Distribution of Cave Dwelling Frogs of Peninsular India

    Directory of Open Access Journals (Sweden)

    Jayant Biswas

    2014-10-01

    Full Text Available The life in subterranean caves always needs a high degree of biological adaptability, due to its unusual ecosystem. The cave dwelling species usually get selected from preadapted biological traits for cave life. The cave dwelling tendencies in frog are very uncommon. Majority of reported cave frogs usually prefer cave for temporary shelter. In India, the biospeleological inventory is still in its primary stage. Till date no serious attempt has been taken to understand the cave dwelling habitat for any frog in India. Inspite of it, in India time to time various reports on natural histories of anurans reveal its cave dwelling tendencies. On the basis of personal observations and available literature in this report I have documented the occurrences and distributions of five cave dwelling frogs of India. Common biological traits from all the established cave frogs, which could be referred as preadapted for cave life, have been discussed. Further, the possible threats and IUCN status of each discussed species has been highlighted.

  7. Is radon emission in caves causing deletions in satellite DNA sequences of cave-dwelling crickets?

    Directory of Open Access Journals (Sweden)

    Giuliana Allegrucci

    Full Text Available The most stable isotope of radon, 222Rn, represents the major source of natural radioactivity in confined environments such as mines, caves and houses. In this study, we explored the possible radon-related effects on the genome of Dolichopoda cave crickets (Orthoptera, Rhaphidophoridae sampled in caves with different concentrations of radon. We analyzed specimens from ten populations belonging to two genetically closely related species, D. geniculata and D. laetitiae, and explored the possible association between the radioactivity dose and the level of genetic polymorphism in a specific family of satellite DNA (pDo500 satDNA. Radon concentration in the analyzed caves ranged from 221 to 26,000 Bq/m3. Specimens coming from caves with the highest radon concentration showed also the highest variability estimates in both species, and the increased sequence heterogeneity at pDo500 satDNA level can be explained as an effect of the mutation pressure induced by radon in cave. We discovered a specific category of nuclear DNA, the highly repetitive satellite DNA, where the effects of the exposure at high levels of radon-related ionizing radiation are detectable, suggesting that the satDNA sequences might be a valuable tool to disclose harmful effects also in other organisms exposed to high levels of radon concentration.

  8. Instrumenting caves to collect hydrologic and geochemical data: case study from James Cave, Virginia

    Science.gov (United States)

    Schreiber, Madeline E.; Schwartz, Benjamin F.; Orndorff, William; Doctor, Daniel H.; Eagle, Sarah D.; Gerst, Jonathan D.

    2015-01-01

    Karst aquifers are productive groundwater systems, supplying approximately 25 % of the world’s drinking water. Sustainable use of this critical water supply requires information about rates of recharge to karst aquifers. The overall goal of this project is to collect long-term, high-resolution hydrologic and geochemical datasets at James Cave, Virginia, to evaluate the quantity and quality of recharge to the karst system. To achieve this goal, the cave has been instrumented for continuous (10-min interval) measurement of the (1) temperature and rate of precipitation; (2) temperature, specific conductance, and rate of epikarst dripwater; (3) temperature of the cave air; and (4) temperature, conductivity, and discharge of the cave stream. Instrumentation has also been installed to collect both composite and grab samples of precipitation, soil water, the cave stream, and dripwater for geochemical analysis. This chapter provides detailed information about the instrumentation, data processing, and data management; shows examples of collected datasets; and discusses recommendations for other researchers interested in hydrologic and geochemical monitoring of cave systems. Results from the research, briefly described here and discussed in more detail in other publications, document a strong seasonality of the start of the recharge season, the extent of the recharge season, and the geochemistry of recharge.

  9. Voluminous submarine lava flows from Hawaiian volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, R.T.; Moore, J.G.; Lipman, P.W.; Belderson, R.H.

    1988-05-01

    The GLORIA long-range sonar imaging system has revealed fields of large lava flows in the Hawaiian Trough east and south of Hawaii in water as deep as 5.5 km. Flows in the most extensive field (110 km long) have erupted from the deep submarine segment of Kilauea's east rift zone. Other flows have been erupted from Loihi and Mauna Loa. This discovery confirms a suspicion, long held from subaerial studies, that voluminous submarine flows are erupted from Hawaiian volcanoes, and it supports an inference that summit calderas repeatedly collapse and fill at intervals of centuries to millenia owing to voluminous eruptions. These extensive flows differ greatly in form from pillow lavas found previously along shallower segments of the rift zones; therefore, revision of concepts of volcano stratigraphy and structure may be required.

  10. Data on the Limanu Cave mineralogy

    Directory of Open Access Journals (Sweden)

    Delia Dumitraş

    2008-01-01

    Full Text Available By means of diphractometric X-rays analyses on powders, we emphasize an association of minerals in the Limanu Cave from South Dobrogea, made up of hydroxylapatite, brushite, calcite, gypsum and dolomite as the main minerals and quartz and illite as secondary minerals.

  11. Meckel's cave tuberculoma with unusual infratemporal extension.

    Science.gov (United States)

    Kesavadas, Chandrasekharan; Somasundaram, S; Rao, Ravi M; Radhakrishnan, V V

    2007-07-01

    The authors describe a rare case of intracranial tuberculoma of the Meckel's cave and cavernous sinus with extension into the infratemporal fossa causing widening of the foramen ovale and adjacent bone destruction. The rarity of the lesion and the unusual extension of the lesion are presented with a brief review of literature.

  12. Xanthoma in Meckel's cave. A case report.

    Science.gov (United States)

    Kimura, H; Oka, K; Nakayama, Y; Tomonaga, M

    1991-04-01

    A case of xanthoma located within Meckel's cave and the semilunar ganglion is described in a patient with a trigeminal nerve deficit. This is the first case of xanthoma in such a location. The distinctive morphological appearance is illustrated and the possible histogenesis is discussed.

  13. The Crystals Cave in a test tube

    Science.gov (United States)

    Puig, C.; Romero, M. L.

    2012-04-01

    It's quite easy to understand formation of crystals in Nature by evaporation of the solutions that contain minerals, but many times we have realised that our pupils hardly understand that precipitation is a process mostly caused by changing parameters in a solution, like pH, temperature, etc. and not necessarily depending on evaporation. We propose a hands-on activity using the context of the Cave of the Crystals in Naica's mine, Mexico. The Crystals Cave is a wonderful place where giant crystals of selenite (gypsum) have grown feeding from a supersaturated anhydrite solution1. Miners discovered the cave filled with hot water, and drained it to explore the gallery. The cave is now a giant laboratory where scientists are looking for the keys to understand geological processes. Teaching sequence (for students 15 years old) is as follows: DISCOVERING A MARVELLOUS PLACE: We showed our pupils several images and a short video of the Cave of the Crystals and ask them about the process that may have caused the phenomenon. Whole-class discussion. PRESENTING A CHALLENGE TO OUR STUDENTS: "COULD WE CREATE A CRYSTALS CAVE IN A TEST TUBE?" EXPERIMENTING TO IMITATE NATURE: Students tried to grow crystals simulating the same conditions as those in Naica's mine. We have chosen KNO3, a salt more soluble than gypsum. We added 85 g of salt to 200 ml of water (solubility of KNO3 at 25°C is 36 g per 100 gr of water) and heated it until it is dissolved. Afterwards, we poured the solution into some test tubes and other recipients and let them cool at room temperature. And they got a beautiful crystals cave!! THINKING A LITTLE MORE: we asked pupils some questions to make them think about the process and to predict what would happen in different situations. For example: a) What would happen with crystals if we heated the tubes again? or b) What would happen if we took the remaining solution from the tubes and keep it in the fridge? PROVING A NEW HYPOTHESIS: Pupils collected the remaining

  14. Leaf evolution in early-diverging ferns: insights from a new fern-like plant from the Late Devonian of China.

    Science.gov (United States)

    Wang, De-Ming; Xu, Hong-He; Xue, Jin-Zhuang; Wang, Qi; Liu, Le

    2015-06-01

    With the exception of angiosperms, the main euphyllophyte lineages (i.e. ferns sensu lato, progymnosperms and gymnosperms) had evolved laminate leaves by the Late Devonian. The evolution of laminate leaves, however, remains unclear for early-diverging ferns, largely represented by fern-like plants. This study presents a novel fern-like taxon with pinnules, which provides new insights into the early evolution of laminate leaves in early-diverging ferns. Macrofossil specimens were collected from the Upper Devonian (Famennian) Wutong Formation of Anhui and Jiangsu Provinces, South China. A standard degagement technique was employed to uncover compressed plant portions within the rock matrix. A new fern-like taxon, SHOUGANGIA BELLA GEN ET SP NOV: , is described and represents an early-diverging fern with highly derived features. It has a partially creeping stem with adventitious roots only on one side, upright primary and secondary branches arranged in helices, tertiary branches borne alternately or (sub)oppositely, laminate and usually lobed leaves with divergent veins, and complex fertile organs terminating tertiary branches and possessing multiple divisions and numerous terminal sporangia. Shougangia bella provides unequivocal fossil evidence for laminate leaves in early-diverging ferns. It suggests that fern-like plants, along with other euphyllophyte lineages, had independently evolved megaphylls by the Late Devonian, possibly in response to a significant decline in atmospheric CO2 concentration. Among fern-like plants, planate ultimate appendages are homologous with laminate pinnules, and in the evolution of megaphylls, fertile organs tend to become complex. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Modeling steam pressure under martian lava flows

    Science.gov (United States)

    Dundas, Colin M.; Keszthelyi, Laszlo P.

    2013-01-01

    Rootless cones on Mars are a valuable indicator of past interactions between lava and water. However, the details of the lava–water interactions are not fully understood, limiting the ability to use these features to infer new information about past water on Mars. We have developed a model for the pressurization of a dry layer of porous regolith by melting and boiling ground ice in the shallow subsurface. This model builds on previous models of lava cooling and melting of subsurface ice. We find that for reasonable regolith properties and ice depths of decimeters, explosive pressures can be reached. However, the energy stored within such lags is insufficient to excavate thick flows unless they draw steam from a broader region than the local eruption site. These results indicate that lag pressurization can drive rootless cone formation under favorable circumstances, but in other instances molten fuel–coolant interactions are probably required. We use the model results to consider a range of scenarios for rootless cone formation in Athabasca Valles. Pressure buildup by melting and boiling ice under a desiccated lag is possible in some locations, consistent with the expected distribution of ice implanted from atmospheric water vapor. However, it is uncertain whether such ice has existed in the vicinity of Athabasca Valles in recent history. Plausible alternative sources include surface snow or an aqueous flood shortly before the emplacement of the lava flow.

  16. [Anatomy of six species of Dryopteris ferns (Dryopteridaceae) from Mexico].

    Science.gov (United States)

    Hernández, Victoria; Terrazas, Teresa; Angeles, Guillermo

    2006-12-01

    Rhizome and foliar anatomy of the Mexican Dryopteris Adans. species were studied and compared with other Dryopteridaceae and other fern families to identify anatomical features with diagnostic value. The anatomy of rhizome, stipe, and blade is similar in species of the Dryopteris patula complex. The cells with un-lignified, thickened wall, with cap or U-shape around the meristeles belong to the collenchyma, in contrast with other fern families. Dryopteris wallichiana (Spreng.) Hyl. is anatomically distinguished from the other studied species by having more layers of sclerenchyma and meristeles on the stipe, and by the lack of sclereid nests on the rhizome. Dryopteris rossii C. Chr. and D. maxonii Underw. & C. Chr. are characterized by the presence of crystals on the periphery of rhizome nests. D. maxonni and D. wallichiana lack blade glands.

  17. A Precious Fern Species Discovered in Jiulong, Sichuan

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Supported by the US National Science Foundation and the National Natural Science Foundation of China, a rare and endangered fern, Isoetes hypsophila, was discovered by a Sino-US research team headed by Prof. SUN Hang from the CAS Kunming Institute of Botany (KIB) and Dr. David E. Boufford from Harvard University in a recent trip to Jiulong, Sichuan, during its botanical survey in the Hengduan Mountains in south China. Scientists say the plant is found for the first time in the region.

  18. Variation of desiccation tolerance and longevity in fern spores.

    Science.gov (United States)

    Ballesteros, Daniel; Hill, Lisa M; Walters, Christina

    2017-04-01

    This work contributes to the understanding of plant cell responses to extreme water stress when it is applied at different intensity and duration. Fern spores are used to explore survival at relative humidity (RH)desiccation damage occurs in desiccation tolerant cells, and that it is expressed as a time-dependent response, otherwise known as aging. Copyright © 2017 Elsevier GmbH. All rights reserved.

  19. Morphology, Physiology, and Anatomy of Penny Fern (Drymoglossum phyloselloidesand Its Effect on Cocoa

    Directory of Open Access Journals (Sweden)

    Fitria Yuliasmara

    2013-08-01

    Full Text Available This study aims to determine the anatomy, physiology and morphology of penny fern (Drimoglosum phylloseloides and its effect on cocoa. Morphological observation of penny fern used microscope to observe the roots, stems, leaves and spores. Physiology of penny fern was observed based on number of stomata and stomatal conductance using stomata printing method, while the amount of chlorophyll based on spectrophotometric method and rate of transpiration used cobalt chloride paper. Penny fern anatomy on cross-sectional and longitudinal in roots, stems and leaves. Penny fern growth was observed based the length of tendrils once a week during rainy and dry season. While the effect of penny fern invasion was observed based on variable leaf area with gravimetric method, the cross-section of attacked cacao branch using microtom and microscope and chlorophyll content by chlorophyll meter. Results showed that penny fern is a epiphytic weed which was crassulaceae acid metabolism plants that have the ability to absorb carbon dioxide at night and carry out photosynthesis during the day with closed stomata. Penny ferns reproduce using spores. The growth rate of penny fern 2.18 cm/week during the dry season and while in rainy season 3.89 cm/week. Penny fern leaf contains 0.0212 mg/g chlorophyll. Penny fern stomata density was 18.33/mm 2 with a width of opening stomata at night 26.3 µm which caused a veryslow rate of transpiration of 0.69 mm 2 /seconds. The existence penny fern on cocoa decreased leaf area and chlorophyll content decreased crop productivity which was indicated by decreasing in number of flowers, number of small, medium fruit, and large pods. However it had no effect on the number of leaves on one side flush cocoa. Key words: Drimoglosum phylloseloides, weeds, decrease productivity, Theobroma cacao

  20. Asplenium bird’s nest ferns in rainforest canopies are climate-contingent refuges for frogs

    OpenAIRE

    Brett R Scheffers; Ben L. Phillips; Shoo, Luke P

    2014-01-01

    Epiphytes are important for canopy dwelling organisms because they provide a cool and moist microhabitat in the relatively hot and dry canopy. Here we examine whether epiphytic Asplenium ferns act as important habitats for arboreal frogs. We conducted extensive fern and habitat surveys for frogs in the Philippines, and complimented these surveys with roaming day and night canopy surveys to identify the full extent of habitat use across the vertical strata. We artificially dried ferns of vario...

  1. The physiological implications of primary xylem organization in two ferns.

    Science.gov (United States)

    Brodersen, Craig R; Roark, Lindsey C; Pittermann, Jarmila

    2012-11-01

    Xylem structure and function are well described in woody plants, but the implications of xylem organization in less-derived plants such as ferns are poorly understood. Here, two ferns with contrasting phenology and xylem organization were selected to investigate how xylem dysfunction affects hydraulic conductivity and stomatal conductance (g(s)). The drought-deciduous pioneer species, Pteridium aquilinum, exhibits fronds composed of 25 to 37 highly integrated vascular bundles with many connections, high g(s) and moderate cavitation resistance (P50 = -2.23 MPa). By contrast, the evergreen Woodwardia fimbriata exhibits sectored fronds with 3 to 5 vascular bundles and infrequent connections, low g(s) and high resistance to cavitation (P50 = -5.21 MPa). Xylem-specific conductivity was significantly higher in P. aqulinium in part due to its wide, efficient conduits that supply its rapidly transpiring pinnae. These trade-offs imply that the contrasting xylem organization of these ferns mirrors their divergent life history strategies. Greater hydraulic connectivity and g(s) promote rapid seasonal growth, but come with the risk of increased vulnerability to cavitation in P. aquilinum, while the conservative xylem organization of W. fimbriata leads to slower growth but greater drought tolerance and frond longevity.

  2. Limitation of distribution of two rare ferns in fragmented landscape

    Science.gov (United States)

    Tájek, Přemysl; Bucharová, Anna; Münzbergová, Zuzana

    2011-09-01

    Species distribution in the landscape is limited either by 1. diaspore production, dispersal and establishment abilities or 2. by availability of suitable habitats; 3. or by a combination of both factors. The relative importance of these factors is species-dependent and has mainly been studied for seed plants. We studied the importance of habitat and dispersal limitation for distribution of two rare fern species, Asplenium adulterinum and Asplenium cuneifolium, restricted to serpentine rocks, using analysis of their distribution on a regional scale (several kilometers). Within the model region, all 98 serpentine rocks were mapped. We used data on abiotic characteristics and on the presence of all vascular plant species on the rocks to predict which of the rocks were suitable for the two Asplenium species. Suitable habitats were positively defined mainly by the presence of appropriate microhabitats and the height of the highest rock, which represents the size of space with lowered concurrence. Other determinants of habitat suitability differed between species. Neither species occupied all suitable localities, indicating dispersal limitation. Locality isolation significantly affected one of the species but not the other. Overall, the results suggest that both fern species have suitable but unoccupied localities in the region and demonstrates that ferns, similar to seed plants, are limited by their dispersal ability in the landscape.

  3. Global phylogeny and biogeography of grammitid ferns (Polypodiaceae).

    Science.gov (United States)

    Sundue, Michael A; Parris, Barbara S; Ranker, Tom A; Smith, Alan R; Fujimoto, Erin L; Zamora-Crosby, Delia; Morden, Clifford W; Chiou, Wen-Liang; Chen, Cheng-Wei; Rouhan, Germinal; Hirai, Regina Y; Prado, Jefferson

    2014-12-01

    We examined the global historical biogeography of grammitid ferns (Polypodiaceae) within a phylogenetic context. We inferred phylogenetic relationships of 190 species representing 31 of the 33 currently recognized genera of grammitid ferns by analyzing DNA sequence variation of five plastid DNA regions. We estimated the ages of cladogenetic events on an inferred phylogeny using secondary fossil calibration points. Historical biogeographical patterns were inferred via ancestral area reconstruction. Our results supported four large-scale phylogenetic and biogeographic patterns: (1) a monophyletic grammitid clade that arose among Neotropical polypod ancestors about 31.4 Ma; (2) a paraphyletic assemblage of clades distributed in the Neotropics and the Afro-Malagasy region; (3) a large clade distributed throughout the Asia-Malesia-Pacific region that originated about 23.4 Ma; and, (4) an Australian or New Zealand origin of the circumaustral genus Notogrammitis. Most genera were supported as monophyletic except for Grammitis, Oreogrammitis, Radiogrammitis, and Zygophlebia. Grammitid ferns are a well-supported monophyletic group with two biogeographically distinct lineages: a primarily Neotropical grade exhibiting several independent successful colonizations to the Afro-Malagasy region and a primarily Paleotropical clade exhibiting multiple independent dispersals to remote Pacific islands and temperate, austral regions.

  4. Sorption equilibrium of mercury onto ground-up tree fern

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Y.-S. [Department of Chemical Engineering, I-Shou University, No. 1, Section 1, Hsueh-Cheng Road, Ta-Hsu Hsiang, Kaohsiung County 840, Taiwan (China)], E-mail: ysho@isu.edu.tw; Wang, C.-C. [Department of Chemical Engineering, I-Shou University, No. 1, Section 1, Hsueh-Cheng Road, Ta-Hsu Hsiang, Kaohsiung County 840, Taiwan (China)

    2008-08-15

    The sorption behavior of mercury at different temperatures onto ground-up tree fern was investigated. The experimental results were fitted to two two-parameter isotherms, the Freundlich and Langmuir isotherms, as well as to two three-parameter isotherms, the Redlich-Peterson and Sips isotherms to obtain the characteristic parameters of each model. A comparison of best-fitting was performed using the coefficient of determination and Chi-square test. Both the Langmuir and Redlich-Peterson isotherms were found to well represent the measured sorption data. According to the evaluation using the Langmuir equation, the saturated monolayer sorption capacity of mercury ions onto ground-up tree fern was 26.5 mg/g at 298 K. It was noted that an increase in temperature resulted in a higher mercury ion loading per unit weight of the tree fern. In addition, various thermodynamic parameters, such as {delta}G{sup o}, {delta}H{sup o}, and {delta}S{sup o}, were calculated and compared with the sorption of mercury by other sorbents.

  5. Ferns: the missing link in shoot evolution and development

    Directory of Open Access Journals (Sweden)

    Andrew Robert George Plackett

    2015-11-01

    Full Text Available Shoot development in land plants is a remarkably complex process that gives rise to an extreme diversity of forms. Our current understanding of shoot developmental mechanisms comes almost entirely from studies of angiosperms (flowering plants, the most recently diverged plant lineage. Shoot development in angiosperms is based around a layered multicellular apical meristem that produces lateral organs and/or secondary meristems from populations of founder cells at its periphery. In contrast, non-seed plant shoots develop from either single apical initials or from a small population of morphologically distinct apical cells. Although developmental and molecular information is becoming available for non-flowering plants, such as the model moss Physcomitrella patens, making valid comparisons between highly divergent lineages is extremely challenging. As sister group to the seed plants, the monilophytes (ferns and relatives represent an excellent phylogenetic midpoint of comparison for unlocking the evolution of shoot developmental mechanisms, and recent technical advances have finally made transgenic analysis possible in the emerging model fern Ceratopteris richardii. This review compares and contrasts our current understanding of shoot development in different land plant lineages with the aim of highlighting the potential role that the fern C. richardii could play in shedding light on the evolution of underlying genetic regulatory mechanisms.

  6. Structure-function constraints of tracheid-based xylem: a comparison of conifers and ferns.

    Science.gov (United States)

    Pittermann, Jarmila; Limm, Emily; Rico, Christopher; Christman, Mairgareth A

    2011-10-01

    The ferns comprise one of the most ancient tracheophytic plant lineages, and occupy habitats ranging from tundra to deserts and the equatorial tropics. Like their nearest relatives the conifers, modern ferns possess tracheid-based xylem but the structure-function relationships of fern xylem are poorly understood. Here, we sampled the fronds (megaphylls) of 16 species across the fern phylogeny, and examined the relationships among hydraulic transport, drought-induced cavitation resistance, the xylem anatomy of the stipe, and the gas-exchange response of the pinnae. For comparison, the results are presented alongside a similar suite of conifer data. Fern xylem is as resistant to cavitation as conifer xylem, but exhibits none of the hydraulic or structural trade-offs associated with resistance to cavitation. On a conduit diameter basis, fern xylem can exhibit greater hydraulic efficiency than conifer and angiosperm xylem. In ferns, wide and long tracheids compensate in part for the lack of secondary xylem and allow ferns to exhibit transport rates on a par with those of conifers. We suspect that it is the arrangement of the primary xylem, in addition to the intrinsic traits of the conduits themselves, that may help explain the broad range of cavitation resistance in ferns.

  7. Random ferns method implementation for the general-purpose machine learning

    CERN Document Server

    Kursa, Miron B

    2012-01-01

    In this paper I present an extended implementation of the Random ferns algorithm contained in the R package rFerns. It differs from the original by the ability of consuming categorical and numerical attributes instead of only binary ones. Also, instead of using simple attribute subspace ensemble it employs bagging and thus produce error approximation and variable importance measure modelled after Random forest algorithm. I also present benchmarks' results which show that although Random ferns' accuracy is mostly smaller than achieved by Random forest, its speed and good quality of importance measure it provides make rFerns a reasonable choice for a specific applications.

  8. Leaf photosynthetic rate of tropical ferns is evolutionarily linked to water transport capacity.

    Science.gov (United States)

    Zhang, Shi-Bao; Sun, Mei; Cao, Kun-Fang; Hu, Hong; Zhang, Jiao-Lin

    2014-01-01

    Ferns usually have relatively lower photosynthetic potential than angiosperms. However, it is unclear whether low photosynthetic potential of ferns is linked to leaf water supply. We hypothesized that there is an evolutionary association of leaf water transport capacity with photosynthesis and stomatal density in ferns. In the present study, a series of functional traits relating to leaf anatomy, hydraulics and physiology were assessed in 19 terrestrial and 11 epiphytic ferns in a common garden, and analyzed by a comparative phylogenetics method. Compared with epiphytic ferns, terrestrial ferns had higher vein density (Dvein), stomatal density (SD), stomatal conductance (gs), and photosynthetic capacity (Amax), but lower values for lower epidermal thickness (LET) and leaf thickness (LT). Across species, all traits varied significantly, but only stomatal length (SL) showed strong phylogenetic conservatism. Amax was positively correlated with Dvein and gs with and without phylogenetic corrections. SD correlated positively with Amax, Dvein and gs, with the correlation between SD and Dvein being significant after phylogenetic correction. Leaf water content showed significant correlations with LET, LT, and mesophyll thickness. Our results provide evidence that Amax of the studied ferns is linked to leaf water transport capacity, and there was an evolutionary association between water supply and demand in ferns. These findings add new insights into the evolutionary correlations among traits involving carbon and water economy in ferns.

  9. A >400 kyrs archive of sedimentation in Scladina cave (Belgium)

    Science.gov (United States)

    Vonhof, Hubert; Bonjean, Dominique; Pirson, Stéphane; van der Lubbe, Jeroen; Hellstrom, John; Scholz, Denis; Verheyden, Sophie

    2017-04-01

    Scladina Cave, near the Meuse River in Belgium, is well-known for its well preserved Neanderthal fossils and stone tools. Cave research started in the 1970's, when archeological findings near the entrance of the cave initiated a long-running excavation programme in the -at that time- almost completely sediment-infilled cave. Over the past decades, a wealth of mammal fossils, stone tools, and a mandible of a Neanderthal child were found, and the complex sedimentary context of the cave strata was reconstructed in high detail. Crucial to understanding the cave stratigraphy is the construction of an absolutely dated age model. Until recently, this age model was based on a number of OSL ages, pollen stratigraphy and a few U-series ages on flowstone and stalagmite calcite. These U-series ages, however, had much lower precision than can be obtained by modern MC-ICP-MS techniques. In this study, we present new and more precise U-series ages for the major flow stone levels in Scladina Cave (upper stratigraphical sequence), and two flowstone levels from Sous-Saint-Paul Cave (lower stratigraphical sequence). The oldest flow stone layer dates back to > 400 ka, and the youngest represents the Holocene. The age model shows that flow stone formation typically occurred during warm climate conditions. These findings help to improve the existing age model for Scladina Cave significantly, and place better constraints on the age of individual fossils, and fossil assemblages in the cave.

  10. Cryogenic cave carbonates from the Cold Wind Cave, Nízke Tatry Mountains, Slovakia: Extending the age range of cryogenic cave carbonate formation to the Saalian

    Directory of Open Access Journals (Sweden)

    Zak K.

    2009-07-01

    Full Text Available Cold Wind Cave, located at elevations ranging between 1,600 and 1,700 m a. s. l. in the main range of the Nízke Tatry Mountains(Slovakia, is linked in origin with the adjacent Dead Bats Cave. Together, these caves form a major cave system located within anarrow tectonic slice of Triassic sediments. Both caves have undergone complex multiphase development. A system of sub-horizontalcave levels characterized by large, tunnel-like corridors was formed during the Tertiary, when elevation differences surroundingthe cave were less pronounced than today. The central part of the Nízke Tatry Mountains, together with the cave systems, wasuplifted during the Neogene and Lower Pleistocene, which changed the drainage pattern of the area completely. The formation ofnumerous steep-sloped vadose channels and widespread cave roof frost shattering characterized cave development throughout theQuaternary.In the Cold Wind Cave, extensive accumulations of loose, morphologically variable crystal aggregates of secondary cave carbonateranging in size between less than 1 mm to about 35 mm was found on the surface of fallen limestone blocks. Based on the C andO stable isotope compositions of the carbonate (δ13C: 0.72 to 6.34 ‰, δ18O: –22.61 to –13.68 ‰ V-PDB and the negative relationbetween δ13C and δ18O, the carbonate crystal aggregates are interpreted as being cryogenic cave carbonate (CCC. Publishedmodels suggest the formation of CCC in slowly freezing water pools, probably on the surface of cave ice, most probably duringtransitions from stadials to interstadials. Though the formation of these carbonates is likely one of the youngest events in thesequence of formation of cave sediments of the studied caves, the 230Th/234U ages of three samples (79.7±2.3, 104.0±2.9, and180.0±6.3 ka are the oldest so far obtained for CCC in Central Europe. This is the first description of CCC formation in one caveduring two glacial periods (Saalian and Weichselian.

  11. Actinobacterial Diversity in Volcanic Caves and Associated Geomicrobiological Interactions.

    Science.gov (United States)

    Riquelme, Cristina; Marshall Hathaway, Jennifer J; Enes Dapkevicius, Maria de L N; Miller, Ana Z; Kooser, Ara; Northup, Diana E; Jurado, Valme; Fernandez, Octavio; Saiz-Jimenez, Cesareo; Cheeptham, Naowarat

    2015-01-01

    Volcanic caves are filled with colorful microbial mats on the walls and ceilings. These volcanic caves are found worldwide, and studies are finding vast bacteria diversity within these caves. One group of bacteria that can be abundant in volcanic caves, as well as other caves, is Actinobacteria. As Actinobacteria are valued for their ability to produce a variety of secondary metabolites, rare and novel Actinobacteria are being sought in underexplored environments. The abundance of novel Actinobacteria in volcanic caves makes this environment an excellent location to study these bacteria. Scanning electron microscopy (SEM) from several volcanic caves worldwide revealed diversity in the morphologies present. Spores, coccoid, and filamentous cells, many with hair-like or knobby extensions, were some of the microbial structures observed within the microbial mat samples. In addition, the SEM study pointed out that these features figure prominently in both constructive and destructive mineral processes. To further investigate this diversity, we conducted both Sanger sequencing and 454 pyrosequencing of the Actinobacteria in volcanic caves from four locations, two islands in the Azores, Portugal, and Hawai'i and New Mexico, USA. This comparison represents one of the largest sequencing efforts of Actinobacteria in volcanic caves to date. The diversity was shown to be dominated by Actinomycetales, but also included several newly described orders, such as Euzebyales, and Gaiellales. Sixty-two percent of the clones from the four locations shared less than 97% similarity to known sequences, and nearly 71% of the clones were singletons, supporting the commonly held belief that volcanic caves are an untapped resource for novel and rare Actinobacteria. The amplicon libraries depicted a wider view of the microbial diversity in Azorean volcanic caves revealing three additional orders, Rubrobacterales, Solirubrobacterales, and Coriobacteriales. Studies of microbial ecology in

  12. Additional Observations of Actively Forming Lava Tubes and Associated Structures, Hawaii

    Science.gov (United States)

    Greeley, Ronald

    1972-01-01

    Extensive changes occurred after the initial observations (Greeley, 1971) of lava tube and channel formation associated with the eruption of Mauna Ulu. Individual vents, which apparently acted somewhat independently, merged by collapse of intervening sections to form an elongate trench. Lava erupted from the summit vent flowed down the trench to the lower end and drained through lava tubes into Alae lava lake. Alae lava lake is in turn drained occasionally by other lava tubes and lava tube networks.

  13. Cave Entrance dependent Spore Dispersion of Filamentous Fungi Isolated from Various Sediments of Iron Ore Cave in Brazil: a colloquy on human threats while caving

    Directory of Open Access Journals (Sweden)

    Erika Linzi Silva Taylor

    2014-04-01

    Full Text Available Caves are stable environments with characteristics favoring the development of fungi. The fungal community present in a cave also includes pathogenic and opportunistic species out of which some are also served as energy sources in such energy stared ecosystems. Studies on microbial diversity and their role on such energy starved ecosystem are scarce. The present study was aimed to identify the cultivable filamentous fungi present in the various sediment of an iron ore cave and to recognize them as pathogenic and/or opportunistic species. Further the impact of cave entrance on the spore depositions on various distances dependent sediments were analyzed. The results suggest a diverse microbial community inhabiting the cave and an influence of cave entrance over spore deposition on various sediments. We counted a total of 4,549 filamentous fungi that included 34 species of 12 genera: Acremonium, Aspergillus, Cladosporium, Fusarium, Geotrichum, Paecilomyces, Purpureocillium, Penicillium, Torula, Trichoderma, Mucor and Rhizopus. A positive significant relation was observed between spore deposition and distance from cave entrance (p= 0.001. Areas of potential mycoses risks were recognized. This is the first study on microbiological community of an iron ore cave in the country.

  14. Gusev Rocks Solidified from Lava (3-D)

    Science.gov (United States)

    2006-01-01

    In recent weeks, as NASA's Mars Exploration Rover Spirit has driven through the basin south of 'Husband Hill,' it has been traversing mainly sand and dune deposits. This week, though, Spirit has been maneuvering along the edge of an arc-shaped feature called 'Lorre Ridge' and has encountered some spectacular examples of basaltic rocks with striking textures. This panoramic camera (Pancam) image shows a group of boulders informally named 'FuYi.' These basaltic rocks were formed by volcanic processes and may be a primary constituent of Lorre Ridge and other interesting landforms in the basin. Spirit first encountered basalts at its landing site two years ago, on a vast plain covered with solidified lava that appeared to have flowed across Gusev Crater. Later, basaltic rocks became rare as Spirit climbed Husband Hill. The basaltic rocks that Spirit is now seeing are interesting because they exhibit many small holes or vesicles, similar to some kinds of volcanic rocks on Earth. Vesicular rocks form when gas bubbles are trapped in lava flows and the rock solidifies around the bubbles. When the gas escapes, it leaves holes in the rock. The quantity of gas bubbles in rocks on Husband Hill varies considerably; some rocks have none and some, such as several here at FuYi, are downright frothy. The change in textures and the location of the basalts may be signs that Spirit is driving along the edge of a lava flow. This lava may be the same as the basalt blanketing the plains of Spirit's landing site, or it may be different. The large size and frothy nature of the boulders around Lorre Ridge might indicate that eruptions once took place at the edge of the lava flow, where the lava interacted with the rocks of the basin floor. Scientists hope to learn more as Spirit continues to investigate these rocks. As Earth approaches the Chinese New Year (The Year of the Dog), the Athena science team decided to use nicknames representing Chinese culture and geography to identify rocks and

  15. Gusev Rocks Solidified from Lava (False Color)

    Science.gov (United States)

    2006-01-01

    In recent weeks, as NASA's Mars Exploration Rover Spirit has driven through the basin south of 'Husband Hill,' it has been traversing mainly sand and dune deposits. This week, though, Spirit has been maneuvering along the edge of an arc-shaped feature called 'Lorre Ridge' and has encountered some spectacular examples of basaltic rocks with striking textures. This panoramic camera (Pancam) image shows a group of boulders informally named 'FuYi.' These basaltic rocks were formed by volcanic processes and may be a primary constituent of Lorre Ridge and other interesting landforms in the basin. Spirit first encountered basalts at its landing site two years ago, on a vast plain covered with solidified lava that appeared to have flowed across Gusev Crater. Later, basaltic rocks became rare as Spirit climbed Husband Hill. The basaltic rocks that Spirit is now seeing are interesting because they exhibit many small holes or vesicles, similar to some kinds of volcanic rocks on Earth. Vesicular rocks form when gas bubbles are trapped in lava flows and the rock solidifies around the bubbles. When the gas escapes, it leaves holes in the rock. The quantity of gas bubbles in rocks on Husband Hill varies considerably; some rocks have none and some, such as several here at FuYi, are downright frothy. The change in textures and the location of the basalts may be signs that Spirit is driving along the edge of a lava flow. This lava may be the same as the basalt blanketing the plains of Spirit's landing site, or it may be different. The large size and frothy nature of the boulders around Lorre Ridge might indicate that eruptions once took place at the edge of the lava flow, where the lava interacted with the rocks of the basin floor. Scientists hope to learn more as Spirit continues to investigate these rocks. As Earth approaches the Chinese New Year (The Year of the Dog), the Athena science team decided to use nicknames representing Chinese culture and geography to identify rocks and

  16. Dandak: a mammalian dominated cave ecosystem of India

    Directory of Open Access Journals (Sweden)

    Jayant Biswas

    2011-03-01

    Full Text Available Perpetual darkness, high humidity with almost constant geophysical factors are some of the abiotic factors which make the cave ecosystem unique. For any species a high degree of adaptation is always needed to thrive in such an ecosystem. Mammals in general have never adapted to cave life but they can play a major role in the cave ecosystem. Structurally, the Dandak cave has two distinct chambers that are completely different from each other in several geophysical factors. Thus both the cave chambers offer two distinct types of ecological niche. In the present study we found that both chambers of this cave were dominated by mammals all year round. Additionally, the group of mammals using the outer chamber completely differs from the group using the inner one. Possible geophysical factors responsible for such differences are discussed.

  17. Chips Off an Old Lava Flow

    Science.gov (United States)

    Taylor, G. J.

    2007-12-01

    Photogeologic and remote sensing studies of the Moon show that many light-colored, smooth areas in the highlands contain craters surrounded by dark piles of excavated debris. The dark deposits resemble the dark basalts that make up the lunar maria. They contain the same diagnostic minerals (especially high-calcium pyroxene) and chemical compositions (high iron oxide) as do mare basalts. The deposits formed when vast amounts of material ejected during the formation of giant impact basins covered pre-existing lava plains. Since the smooth plains are older than the youngest impact basin (about 3.8 billion years old), the lavas must have erupted before formation of the visible maria. In fact, they were visible maria for a while eons ago, but were buried by ejecta when the basins formed. We have samples of these ancient mare basalts. They reside in breccias collected from the lunar highlands. Age dating indicates that the chips have ages of 3.9 billion years and older. The oldest dated mare basalt in the Apollo collection is 4.23 billion years. Now Kentaro Terada (Hiroshima University, Japan), Mahesh Anand (Open University, UK), Anna Sokol and Addi Bischoff (Institute for Planetology, Muenster, Germany), and Yuji Sano (The University of Tokyo, Japan) have determined the age of pieces of an ancient lava flow in a lunar meteorite, Kalahari 009, found in Botswana in 1999. The team dated this very low-titanium mare basalt by using an ion microprobe to measure the isotopic composition of lead and uranium in phosphate minerals. They found that the basalt fragments in the rock have an age of about 4.35 (plus or minus 0.15) billion years. This overlaps with the ages of chemically-distinct igneous rocks from the highlands, indicating that diverse magmas were being produced early in the history of the Moon.

  18. Identifying hazards associated with lava deltas

    Science.gov (United States)

    Poland, Michael P.; Orr, Tim R.

    2014-01-01

    Lava deltas, formed where lava enters the ocean and builds a shelf of new land extending from the coastline, represent a significant local hazard, especially on populated ocean island volcanoes. Such structures are unstable and prone to collapse—events that are often accompanied by small explosions that can deposit boulders and cobbles hundreds of meters inland. Explosions that coincide with collapses of the East Lae ‘Apuki lava delta at Kīlauea Volcano, Hawai‘i, during 2005–2007 followed an evolutionary progression mirroring that of the delta itself. A collapse that occurred when the lava–ocean entry was active was associated with a blast of lithic blocks and dispersal of spatter and fine, glassy tephra. Shortly after delta growth ceased, a collapse exposed hot rock to cold ocean water, resulting in an explosion composed entirely of lithic blocks and lapilli. Further collapse of the delta after several months of inactivity, by which time it had cooled significantly, resulted in no recognizable explosion deposit. Seaward displacement and subsidence of the coastline immediately inland of the delta was measured by both satellite and ground-based sensors and occurred at rates of several centimeters per month even after the lava–ocean entry had ceased. The anomalous deformation ended only after complete collapse of the delta. Monitoring of ground deformation may therefore provide an indication of the potential for delta collapse, while the hazard associated with collapse can be inferred from the level of activity, or the time since the last activity, on the delta.

  19. Water properties in fern spores: sorption characteristics relating to water affinity, glassy states, and storage stability.

    Science.gov (United States)

    Ballesteros, Daniel; Walters, Christina

    2007-01-01

    Ex situ conservation of ferns may be accomplished by maintaining the viability of stored spores for many years. Storage conditions that maximize spore longevity can be inferred from an understanding of the behaviour of water within fern spores. Water sorption properties were measured in spores of five homosporeous species of ferns and compared with properties of pollen, seeds, and fern leaf tissue. Isotherms were constructed at 5, 25, and 45 degrees C and analysed using different physicochemical models in order to quantify chemical affinity and heat (enthalpy) of sorption of water in fern spores. Fern spores hydrate slowly but dry rapidly at ambient relative humidity. Low Brunauer-Emmet-Teller monolayer values, few water-binding sites according to the D'Arcy-Watt model, and limited solute-solvent compatibility according to the Flory-Huggins model suggest that fern spores have low affinity for water. Despite the low water affinity, fern spores demonstrate relatively high values of sorption enthalpy (DeltaH(sorp)). Parameters associated with binding sites and DeltaH(sorp) decrease with increasing temperature, suggesting temperature- and hydration-dependent changes in volume of spore macromolecules. Collectively, these data may relate to the degree to which cellular structures within fern spores are stabilized during drying and cooling. Water sorption properties within fern spores suggest that storage at subfreezing temperatures will give longevities comparable with those achieved with seeds. However, the window of optimum water contents for fern spores is very narrow and much lower than that measured in seeds, making precise manipulation of water content imperative for achieving maximum longevity.

  20. Sensing Structures Inspired by Blind Cave Fish

    Science.gov (United States)

    McConney, Michael E.; Chen, Nannan; Lu, David; Anderson, Kyle D.; Hu, Huan; Liu, Chang; Tsukruk, Vladimir V.

    2009-03-01

    Blind cave fish, with degenerated non-functioning eyes, have evolved to ``see'' their hydrodynamic environment by using the flow receptors of the lateral line system. The hair-cell receptors are encapsulated in a hydrogel-like material, called a cupula, which increases the sensitivity of the hair-cell receptors by coupling their motion to the surrounding flowing media. We characterized the viscoelastic properties and of blind cave fish cupulae by using colloidal-probe spectroscopy in fluid. A photo-patternable hydrogel with similar properties was developed to mimic the fish receptor coupling structure. Flow-based measurements indicated that the hydrogels enhance drag through increased surface area, but also inherent material properties. These bio-inspired structures endowed micro-fabricated flow sensors with sensitivities rivaling that of fish.

  1. Hotspot mitigation in the StarCAVE

    KAUST Repository

    Rhee, Jordan

    2010-01-27

    Rear-projected screens such as those in Digital Light Projection (DLP) televisions suffer from an image quality problem called hot spotting, where the image is brightest at a point dependent on the viewing angle. In rear-projected mulit-screen configurations such as the StarCAVE at Calit2, this causes discontinuities in brightness at the edges where screens meet, and thus in the 3D image perceived by the user. In the StarCAVE we know the viewer\\'s position in 3D space and we have programmable graphics hardware, so we can mitigate this effect by performing post-processing in the inverse of the pattern, yielding a homogenous image at the output. Our implementation improves brightness homogeneity by a factor of 4 while decreasing frame rate by only 1-3 fps.

  2. Laboratory Investigations of Lava Flow Heat Transfer

    Science.gov (United States)

    Fagents, S. A.; Rumpf, M. E.; Hamilton, C. W.

    2011-12-01

    To investigate the effectiveness with which lava can heat substrates of different types, we conducted a suite of experiments in which molten basalt was poured onto solid or particulate materials, and the downward propagation of the heat pulse was measured. The motivation for this work lies in seeking to understand how lava flows on the Moon would have heated the underlying regolith, and thus to determine the depths at which solar wind particles implanted in the regolith would have been protected from the heat of the overlying flow. Extraction and analysis of ancient solar wind samples would provide a wealth of information on the evolution and fate of the Sun. Our experimental device consists of a box constructed from 1"-thick calcium silicate sheeting with interior dimensions of 20 x 20 x 25 cm. The substrate material (a particulate lunar regolith simulant or solid basalt) occupies the lower 15 cm of the box, which is embedded with an array of 8 thermocouples. Up to 6 kg of crushed basalt collected from the 2010 Kilauea lava flows is heated to supraliquidus temperatures and poured directly onto the substrate. The evolution of the temperature profile within the lava flow and substrate is recorded as the basalt cools, and the surface temperature distribution is recorded using a Forward Looking Infrared Radiometer (FLIR) video camera. We have been using the experimental data sets to validate a numerical model of substrate heating. If the physics is appropriately formulated, the model will accurately predict both surface and internal temperature distribution as a function of time. A key issue has been incorporation of valid temperature-dependent thermophysical properties, because particulate materials are not well characterized at elevated temperatures. Regolith thermal conductivity in particular exerts a strong control over the depth of penetration of the thermal wave, so its accurate description is essential for a robust model. Comparison of experimental vs. modeled

  3. A progress report on the work toward propagation and reintroduction of the threatened plant American Hart's Tongue Fern (Phyllitis scolopendrium)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Report describes efforts to propogate the fern spores in the lab. Attempts to propagate the spores from the Am. Hart's Tongue Fern in the Lab is reviewed. Spores...

  4. Toxicity and Geochemistry of Missouri Cave Stream Sediments

    Science.gov (United States)

    Lawler, C. A.; Besser, J.; Wicks, C. M.

    2005-05-01

    Water and sediment quality are among the most important variables affecting the survival of stygobites. In Tumbling Creek Cave, Taney County Missouri the population of the endangered cave snail, Antrobia culveri, has declined significantly over the past decade. The cause of the population decline is unknown but could be related to the quality of streambed sediment in which the cave snail lives. The objective of this study was to determine the toxicity and concentrations of heavy metals in the sediment of Tumbling Creek Cave and five other caves in Missouri. These sediments were analyzed to assess possible point sources from within the recharge areas of the caves and to provide baseline geochemical data to which Tumbling Creek Cave sediments could be compared. Standard sediment toxicity tests and ICP-MS analysis for heavy metals were conducted. Survival and reproduction of the amphipod, Hyalella azteca, did not differ significantly between cave sediments and a control sediment. However the growth of amphipods differed significantly among sites and was significantly reduced in sediments from Tumbling Creek Cave relative to controls. Concentrations of several metals in sediments differed substantially among locations, with elevated levels of zinc and copper occurring in Tumbling Creek Cave. However, none of the measured metal concentrations exceeded sediment quality guidelines derived to predict probable effects on benthic organisms and correlations between sediment metal concentrations and toxicity endpoints were generally weak. While elevated metal levels may play a part in the cave snail's decline, other factors may be of equal or greater importance. Ongoing analyses of persistent organic contaminants and total organic carbon in cave sediments, along with continued water quality monitoring, may provide data that will allow us to better understand this complicated problem.

  5. Primary melanoma of Meckel's cave: case report.

    Science.gov (United States)

    Falavigna, Asdrubal; Borba, Luis A B; Ferraz, Fernando Antonio Patriani; Almeida, Giovana Camargo de; Krindges Júnior, José Valentim

    2004-06-01

    We present a case of trigeminal neuralgia with cranial normal magnetic resonance image (MRI) and computed tomography. The pain was not relieved by carbamazepine and microvascular decompression surgery was done. After two months the pain was similar to the condition before surgery. At this time, MRI showed an expansive lesion in Meckel's cave that was treated with radical resection by extra-dural approach. The pathologic examination revealed a primary melanoma. The follow-up after six months did not show abnormalities.

  6. Primary melanoma of Meckel's cave: case report

    OpenAIRE

    Falavigna,Asdrubal; Luis A. B. Borba; Ferraz, Fernando Antonio Patriani [UNIFESP; Almeida,Giovana Camargo de; Krindges Júnior,José Valentim

    2004-01-01

    We present a case of trigeminal neuralgia with cranial normal magnetic resonance image (MRI) and computed tomography. The pain was not relieved by carbamazepine and microvascular decompression surgery was done. After two months the pain was similar to the condition before surgery. At this time, MRI showed an expansive lesion in Meckel's cave that was treated with radical resection by extra-dural approach. The pathologic examination revealed a primary melanoma. The follow-up after six months d...

  7. Revisiting three minerals from Cioclovina Cave (Romania

    Directory of Open Access Journals (Sweden)

    Onac Bogdan P.

    2011-07-01

    Full Text Available Cioclovina Cave in Romania’s Southern Carpathians is a world-renowned cave site for its paleontological, anthropological, andmineralogical (type locality of ardealite finds. To date, over 25 mineral species have been documented, some unusual for a caveenvironment. This paper presents details on the occurrence of collinsite [Ca2(Mg,Fe2+(PO42·2H2O], atacamite [Cu22+Cl(OH3], andkröhnkite [Na2Cu2+(SO42·2H2O] based on single-crystal X-ray diffraction, electron microprobe, stable isotope analyses, and scanningelectron microscope imaging. This is the first reported occurrence of kröhnkite in a cave environment. Atacamite representsthe weathering product (in the presence of Lower-Cretaceous limestone-derived chlorine of copper minerals washed into the cavefrom nearby ore bodies. Atacamite and kröhnkite have similar sources for copper and chlorine, whereas sodium probably originatesfrom weathered Precambrian and Permian detrital rocks. Collinsite is believed to have precipitated from bat guano in a damp, nearneutralpH environment. The results show the following sequence of precipitation: ardealite-brushite-(gypsum-atacamite-kröhnkite.This suggests that the observed mineral paragenesis is controlled by the neutralization potential of the host-rock mineralogy and theconcentrations of Ca, Cl, Cu, and Na.

  8. Depth Perception in Cave and Panorama

    DEFF Research Database (Denmark)

    Mullins, Michael; Strojan, Tadeja Zupancic

    2004-01-01

    This study compares aspects of spatial perception in a physical environment and its virtual representations in a CAVE and Panorama, derived from recent research. To measure accuracy of spatial perception, participants in an experiment were asked to look at identical objects in the three environme......, learning and training in virtual environments; in architectural education; and participatory design processes, in which the dialogue between real and imagined space may take place in virtual . reality environments...... environments and then locate them and identify their shape on scaled drawings.  Results are presented together with statistical analysis. In a discussion of the results, the paper addresses the two hypothetical assertions ? that depth perception in physical reality and its virtual representations in CAVE......This study compares aspects of spatial perception in a physical environment and its virtual representations in a CAVE and Panorama, derived from recent research. To measure accuracy of spatial perception, participants in an experiment were asked to look at identical objects in the three...

  9. An Investigation of Meromixis in Cave Pools, Lechuguilla Cave, New Mexico.

    Directory of Open Access Journals (Sweden)

    David B. Levy

    2008-07-01

    Full Text Available Chemical characteristics of permanent stratification in cave pools (meromixis may provide insight into the geochemical origin and evolution of cave pool waters. The objective of this study was to test the hypothesis that some pools in Lechuguilla Cave may be subject to ectogenic meromixis, where permanent chemical stratification is induced by input of relatively saline or fresh water from an external source. However, because organic C concentrations in Lechuguilla waters are low (typically 0.9 m, and are probably the result of localized and transient atmospheric CO2(g concentrations. At LOBG, an EC increase of 93 µS cm-1 at the 0.9-m depth suggests meromictic conditions which are ectogenic, possibly due to surface inflow of fresh water as drips or seepage into a pre-existing layer of higher salinity.

  10. Bacteria and free-living amoeba in the Lascaux Cave.

    Science.gov (United States)

    Bastian, Fabiola; Alabouvette, Claude; Saiz-Jimenez, Cesareo

    2009-01-01

    The Lascaux Cave was discovered in 1940, and by 1960 it had received up to 1800 daily visitors. In 1963, the cave was closed and in 2001 it was invaded by a Fusarium solani species complex which was treated for four years with benzalkonium chloride. However, Lascaux Cave bacteria have only been poorly investigated. Here we show that the cave is now a reservoir of potential pathogenic bacteria and protozoa which can be found in outbreaks linked to air-conditioning systems and cooling towers in community hospitals and public buildings.

  11. Measuring radon concentrations and estimating dose in tourist caves.

    Science.gov (United States)

    Martín Sánchez, A; de la Torre Pérez, J; Ruano Sánchez, A B; Naranjo Correa, F L

    2015-11-01

    Caves and mines are considered to be places of especial risk of exposure to (222)Rn. This is particularly important for guides and workers, but also for visitors. In the Extremadura region (Spain), there are two cave systems in which there are workers carrying out their normal everyday tasks. In one, visits have been reduced to maintain the conditions of temperature and humidity. The other comprises several caves frequently visited by school groups. The caves were radiologically characterised in order to estimate the dose received by workers or possible hazards for visitors.

  12. Eruptive behavior of the Marum/Mbwelesu lava lake, Vanuatu and comparisons with lava lakes on Earth and Io

    Science.gov (United States)

    Radebaugh, Jani; Lopes, Rosaly M.; Howell, Robert R.; Lorenz, Ralph D.; Turtle, Elizabeth P.

    2016-08-01

    Observations from field remote sensing of the morphology, kinematics and temperature of the Marum/Mbwelesu lava lake in the Vanuatu archipelago in 2014 reveal a highly active, vigorously erupting lava lake. Active degassing and fountaining observed at the 50 m lava lake led to large areas of fully exposed lavas and rapid ( 5 m/s) movement of lava from the centers of upwelling outwards to the lake margins. These rapid lava speeds precluded the formation of thick crust; there was never more than 30% non-translucent crust. The lava lake was observed with several portable, handheld, low-cost, near-infrared imagers, all of which measured temperatures near 1000 °C and one as high as 1022 °C, consistent with basaltic temperatures. Fine-scale structure in the lava fountains and cooled crust was visible in the near infrared at 5 cm/pixel from 300 m above the lake surface. The temperature distribution across the lake surface is much broader than at more quiescent lava lakes, peaking 850 °C, and is attributed to the highly exposed nature of the rapidly circulating lake. This lava lake has many characteristics in common with other active lava lakes, such as Erta Ale in Ethiopia, being confined, persistent and high-temperature; however it was much more active than is typical for Erta Ale, which often has > 90% crust. Furthermore, it is a good analogue for the persistent, high-temperature lava lakes contained within volcanic depressions on Jupiter's moon Io, such as Pele, also believed from spacecraft and ground-based observations to exhibit similar behavior of gas emission, rapid overturn and fountaining.

  13. Some deep caves in Biokovo Mountain (Croatia)

    Science.gov (United States)

    Garasic, Mladen; Garasic, Davor

    2014-05-01

    The investigation of 3 caves explored more than 1000 meters in depth in the Dinaric karst area in Croatia, has been in progress for a considerable period of time. These are complex speleological features situated in the longest mountain range of the Dinaric karst, i.e. at the Northern Velebit mountain range. In fact, these caves have been studied for over two decades now. The first one is a cave system of Lukina jama (Luke's Cave) - Trojama cave, which has been investigated until the depth of 1421 meters (Jalžić, 2007; Šmida, 1993). Its total length is 3731 meters and a new expedition will soon continue to investigate this pit through speleodiving in siphons. The second greatest cave by depth is Slovačka jama (Slovak Cave), 1320 meters in depth, with cave chanals measuring 5677 meters in total length. The third greatest cave by depth is the Cave system of Velebita, reaching down to 1026 m in depth, with the chanal length of 3176 meters (Bakšić, 2006a; 2006b). However, another 3 speleological sites, which can rightly be added to those deeper than 1000 m, have recently been discovered. These are three caverns that were discovered during construction of the Sveti Ilija Tunnel that passes through Mt. Biokovo, in the Dinaric karst area. These caverns undoubtedly point to the link with the ground surface, while the rock overburden above the tunnel in the zone where the caverns were discovered ranges from 1250 and 1350 meters. Bats from the ground surface were found in the caverns and, according to measurements, they are situated in the depth from 200 and 300 meters below the tunnel level. This would mean that the depth of these newly found caves ranges from 1450 and 1650 m, when observed from the ground surface. There are several hundreds of known caves in Biokovo, and the deepest ones discovered so far are Jama Mokre noge (Wet Feet Cave) 831 m in depth, and Jama Amfora (Amphora Cave) 788 m in depth (Bockovac, 1999; Bakšić & all, 2002; Lacković & all, 2001

  14. Linkage of cave-ice changes to weather patterns inside and outside the cave Eisriesenwelt (Tennengebirge, Austria

    Directory of Open Access Journals (Sweden)

    W. Schöner

    2010-09-01

    Full Text Available The behaviour of perennial ice masses in karst caves in relation to the outside climate is still not well understood, though a significant potential of the cave-ice for paleo-climate reconstructions could be expected. This study investigates the relationship between weather patterns inside and outside the cave Eisriesenwelt (Austrian Alps and the ice-surface changes of the ice-covered part of the cave from extensive measurements. It is shown that under recent climate the cave ice mass balance is more sensitive to winter climate for the inner parts of the cave and sensitive to winter and summer climate for the entrance near parts of the cave. For recent climate conditions ice surface changes can be well described from cave atmosphere measurements, indicating a clear annual cycle with weak mass loss in winter due to sublimation, stable ice conditions in spring until summer (autumn for the remoter parts of the cave and significant melt in late summer to autumn (for the entrance near parts of the cave. Interestingly, surface ice melt plays a minor role for ablation at the inner parts of the cave. Based on our measurements and other observations it is rather likely that sublimation was the major source for ice loss in Eisriesenwelt since the begin of the 20th century. Build-up of the ice in spring (as expected from theory was not observed as a general feature of the ice dynamics. Generally, the ice body currently appears in a quite balanced state, though the influence of show-cave management on ice mass-balance could not be clearly quantified.

  15. Conservation of prehistoric caves and stability of their inner climate: lessons from Chauvet and other French caves.

    Science.gov (United States)

    Bourges, F; Genthon, P; Genty, D; Lorblanchet, M; Mauduit, E; D'Hulst, D

    2014-09-15

    In the last 150 years, some prehistoric painted caves suffered irreversible degradations due to misperception of conservation issues and subsequent mismanagement. These sites presented naturally an exceptional stability of their internal climate allowing conservation in situ of outstanding fragile remains, some for nearly 40,000 years. This is for a large part due to exchanges of air, CO2, heat and water with the karstic system in which these caves are included. We introduce the concept of underground confinement, based on the stability of the inner cave climate parameters, especially its temperature. Confined caves present the best conservative properties. It is emphasized that this confined state implies slow exchanges with the surrounding karst and that a stable cave cannot be viewed as a closed system. This is illustrated on four case studies of French caves of various confinement states evidenced by long term continuous monitoring and on strategies to improve their conservation properties. The Chauvet cave presents optimal conservation properties. It is wholly confined as shown by the stability of its internal parameters since its discovery in 1994. In Marsoulas cave, archeological works removed the entrance scree and let a strong opening situation of the decorated zone. Remediation is expected by adding a buffer structure at the entrance. In Pech Merle tourist cave, recurrent painting fading was related to natural seasonal drying of walls. Improvement of the cave closure system restored a confined state insuring optimal visibility of the paintings. In Gargas tourist cave, optimization of closures, lighting system and number of visitors, allowed it to gradually reach a semi-confined state that improved the conservation properties. Conclusions are drawn on the characterization of confinement state of caves and on the ways to improve their conservation properties by restoring their initial regulation mechanisms and to avoid threats to their stability.

  16. Lava tube shatter rings and their correlation with lava flux increases at Kīlauea Volcano, Hawai‘i

    Science.gov (United States)

    Orr, T.R.

    2011-01-01

    Shatter rings are circular to elliptical volcanic features, typically tens of meters in diameter, which form over active lava tubes. They are typified by an upraised rim of blocky rubble and a central depression. Prior to this study, shatter rings had not been observed forming, and, thus, were interpreted in many ways. This paper describes the process of formation for shatter rings observed at Kīlauea Volcano during November 2005–July 2006. During this period, tilt data, time-lapse images, and field observations showed that episodic tilt changes at the nearby Pu‘u ‘Ō‘ō cone, the shallow magmatic source reservoir, were directly related to fluctuations in the level of lava in the active lava tube, with periods of deflation at Pu‘u ‘Ō‘ō correlating with increases in the level of the lava stream surface. Increases in lava level are interpreted as increases in lava flux, and were coincident with lava breakouts from shatter rings constructed over the lava tube. The repetitive behavior of the lava flux changes, inferred from the nearly continuous tilt oscillations, suggests that shatter rings form from the repeated rise and fall of a portion of a lava tube roof. The locations of shatter rings along the active lava tube suggest that they form where there is an abrupt decrease in flow velocity through the tube, e.g., large increase in tube width, abrupt decrease in tube slope, and (or) sudden change in tube direction. To conserve volume, this necessitates an abrupt increase in lava stream depth and causes over-pressurization of the tube. More than a hundred shatter rings have been identified on volcanoes on Hawai‘i and Maui, and dozens have been reported from basaltic lava fields in Iceland, Australia, Italy, Samoa, and the mainland United States. A quick study of other basaltic lava fields worldwide, using freely available satellite imagery, suggests that they might be even more common than previously thought. If so, this confirms that episodic

  17. Lava tube shatter rings and their correlation with lava flux increases at Kīlauea Volcano, Hawai`i

    Science.gov (United States)

    Orr, Tim R.

    2011-04-01

    Shatter rings are circular to elliptical volcanic features, typically tens of meters in diameter, which form over active lava tubes. They are typified by an upraised rim of blocky rubble and a central depression. Prior to this study, shatter rings had not been observed forming, and, thus, were interpreted in many ways. This paper describes the process of formation for shatter rings observed at Kīlauea Volcano during November 2005-July 2006. During this period, tilt data, time-lapse images, and field observations showed that episodic tilt changes at the nearby Pu`u `Ō`ō cone, the shallow magmatic source reservoir, were directly related to fluctuations in the level of lava in the active lava tube, with periods of deflation at Pu`u `Ō`ō correlating with increases in the level of the lava stream surface. Increases in lava level are interpreted as increases in lava flux, and were coincident with lava breakouts from shatter rings constructed over the lava tube. The repetitive behavior of the lava flux changes, inferred from the nearly continuous tilt oscillations, suggests that shatter rings form from the repeated rise and fall of a portion of a lava tube roof. The locations of shatter rings along the active lava tube suggest that they form where there is an abrupt decrease in flow velocity through the tube, e.g., large increase in tube width, abrupt decrease in tube slope, and (or) sudden change in tube direction. To conserve volume, this necessitates an abrupt increase in lava stream depth and causes over-pressurization of the tube. More than a hundred shatter rings have been identified on volcanoes on Hawai`i and Maui, and dozens have been reported from basaltic lava fields in Iceland, Australia, Italy, Samoa, and the mainland United States. A quick study of other basaltic lava fields worldwide, using freely available satellite imagery, suggests that they might be even more common than previously thought. If so, this confirms that episodic fluctuation in lava

  18. Spatial Characteristics of Edible Wild Fern Harvesting in Mountainous Villages in Northeastern Japan Using GPS Tracks

    Directory of Open Access Journals (Sweden)

    Toshiya Matsuura

    2014-02-01

    Full Text Available Wild plants in forests provide valuable living resources for rural communities. The location where local people harvest various species is important to the wise use of forest ecosystem services. Using global positioning system (GPS tracking of harvesters’ activities as well as geographic information system (GIS and a generalized linear model (GLM, this study analyzed the spatial differences among harvesting sites of three popular edible ferns, i.e., ostrich fern (Matteuccia struthiopteris, bracken (Pteridium aquilinum, and royal fern (Osmunda japonica, in mountainous villages of Northeastern Japan. The explanatory variables used were vegetation classes, terrain features, and proximity to roadways. The GLM yielded clear differences in harvesting sites among species that were affected by both the species’ ecological characteristics and human behavior. Ostrich fern was harvested mainly in canopy openings along valley floors, whereas royal fern harvest sites were frequently located in snow avalanche scrublands. Bracken was mainly harvested in deforested areas or young conifer plantations. Whereas ostrich fern and bracken harvest sites were restricted by the accessibility from roadways, this was not the case for royal fern. Potential harvest sites of ferns were estimated with the highest value for bracken. Our results suggest that local harvesters seriously consider various natural and anthropogenic factors to maintain effective and sustainable harvesting.

  19. Asplenium bird’s nest ferns in rainforest canopies are climate-contingent refuges for frogs

    Directory of Open Access Journals (Sweden)

    Brett R. Scheffers

    2014-12-01

    Full Text Available Epiphytes are important for canopy dwelling organisms because they provide a cool and moist microhabitat in the relatively hot and dry canopy. Here we examine whether epiphytic Asplenium ferns act as important habitats for arboreal frogs. We conducted extensive fern and habitat surveys for frogs in the Philippines, and complimented these surveys with roaming day and night canopy surveys to identify the full extent of habitat use across the vertical strata. We artificially dried ferns of various sizes to identify relationships between water and temperature buffering. Ferns are the preferred diurnal microhabitat and breeding habitat for arboreal frogs. A strong positive relationship exists between fern size and frog usage and abundance. Our drying experiments show that large ferns buffer maximum temperatures and reduce variability in temperatures, and buffering is directly linked to their hydration. Frogs are likely using large ferns for their moist, cool, environments for breeding and daytime retreat, which supports the buffered microhabitat hypothesis—these plants promote species coexistence through habitat creation and amelioration of physical stress. However, drying experiments suggest that this buffering is contingent on regular rainfall. Altered rainfall regimes could lead to the unexpected loss of the functional capacity of these important fern habitats.

  20. Ancestral stomatal control results in a canalization of fern and lycophyte adaptation to drought.

    Science.gov (United States)

    McAdam, Scott A M; Brodribb, Timothy J

    2013-04-01

    Little is known about how a predominantly passive hydraulic stomatal control in ferns and lycophytes might impact water use under stress. Ferns and lycophytes occupy a diverse array of habitats, from deserts to rainforest canopies, raising the question of whether stomatal behaviour is the same under all ecological strategies and imposes ecological or functional constraints on ferns and lycophytes. We examined the stomatal response of a diverse sample of fern and lycophyte species to both soil and atmospheric water stress, assessing the foliar level of the hormone abscisic acid (ABA) over drought and recovery and the critical leaf water potential (Ψl) at which photosynthesis in droughted leaves failed to recover. The stomata of all ferns and lycophytes showed very predictable responses to soil and atmospheric water deficit via Ψl, while stomatal closure was poorly correlated with changes in ABA. We found that all ferns closed stomata at very low levels of water stress and their survival afterwards was limited only by their capacitance and desiccation tolerance. Ferns and lycophytes have constrained stomatal responses to soil and atmospheric water deficit as a consequence of a predominantly passive stomatal regulation. This results in a monotypic strategy in ferns and lycophytes under water stress.

  1. Field Guide to Northeastern Ferns. New York State Museum Bulletin Number 444.

    Science.gov (United States)

    Ogden, Eugene C.

    This guide was developed for use by individuals with little or no botanical training who wish to identify native ferns of New York, New England, New Jersey, and Pennsylvania. A random access key, developed by the author, provides multiple pathways for identification of 60 species in 29 genera of ferns. (CS)

  2. The mucilage secreting hairs on the young fronds of some Leptosporangiate Ferns

    NARCIS (Netherlands)

    Hennipman, E.

    1968-01-01

    During a collecting trip to Thailand, as a member of the Thai-Dutch botanical expedition 1965/1966, I was struck by the excessive amount of mucilage sometimes present on the circinnate fronds of several leptosporangiate ferns. This was especially evident in representatives of the monotypic fern fami

  3. Klukiopsis jurassica——A new Jurassic schizaeaceous fern from China

    Institute of Scientific and Technical Information of China (English)

    邓胜徽[1; 王仕俊[2

    2000-01-01

    A new Jurassic schizaeaceous fern Klukiopsis jurassica gen. et sp. nov. from Yima, Henan Province, China is described. The new fern is characterized by the abaxial sori arranged in two rows, apical and complete annulus and more than 800 smooth trilete spores in each sorus.

  4. 75 FR 23151 - Noxious Weeds; Old World Climbing Fern and Maidenhair Creeper

    Science.gov (United States)

    2010-05-03

    ... Inspection Service 7 CFR Parts 360 and 361 Noxious Weeds; Old World Climbing Fern and Maidenhair Creeper... noxious weed regulations by adding Old World climbing fern (Lygodium microphyllum (Cavanilles) R. Brown) and maidenhair creeper (Lygodium flexuosum (Linnaeus) Swartz) to the list of terrestrial noxious weeds...

  5. The effect of nitrogen additions on bracken fern and its insect herbivores at sites with high and low atmospheric pollution

    Science.gov (United States)

    M.E. Jones; M.E. Fenn; T.D. Paine

    2011-01-01

    The impact of atmospheric pollution, including nitrogen deposition, on bracken fern herbivores has never been studied. Bracken fern is globally distributed and has a high potential to accumulate nitrogen in plant tissue. We examined the response of bracken fern and its herbivores to N fertilization at a high and low pollution site in forests downwind of Los Angeles,...

  6. What factors control the superficial lava dome explosivity?

    Science.gov (United States)

    Boudon, Georges; Balcone-Boissard, Hélène; Villemant, Benoit; Morgan, Daniel J.

    2015-04-01

    Dome-forming eruption is a frequent eruptive style; lava domes result from intermittent, slow extrusion of viscous lava. Most dome-forming eruptions produce highly microcrystallized and highly- to almost totally-degassed magmas which have a low explosive potential. During lava dome growth, recurrent collapses of unstable parts are the main destructive process of the lava dome, generating concentrated pyroclastic density currents (C-PDC) channelized in valleys. These C-PDC have a high, but localized, damage potential that largely depends on the collapsed volume. Sometimes, a dilute ash cloud surge develops at the top of the concentrated flow with an increased destructive effect because it may overflow ridges and affect larger areas. In some cases, large lava dome collapses can induce a depressurization of the magma within the conduit, leading to vulcanian explosions. By contrast, violent, laterally directed, explosions may occur at the base of a growing lava dome: this activity generates dilute and turbulent, highly-destructive, pyroclastic density currents (D-PDC), with a high velocity and propagation poorly dependent on the topography. Numerous studies on lava dome behaviors exist, but the triggering of lava dome explosions is poorly understood. Here, seven dome-forming eruptions are investigated: in the Lesser Antilles arc: Montagne Pelée, Martinique (1902-1905, 1929-1932 and 650 y. BP eruptions), Soufrière Hills, Montserrat; in Guatemala, Santiaguito (1929 eruption); in La Chaîne des Puys, France (Puy de Dome and Puy Chopine eruptions). We propose a new model of superficial lava-dome explosivity based upon a textural and geochemical study (vesicularity, microcrystallinity, cristobalite distribution, residual water contents, crystal transit times) of clasts produced by these key eruptions. Superficial explosion of a growing lava dome may be promoted through porosity reduction caused by both vesicle flattening due to gas escape and syn-eruptive cristobalite

  7. A flexible open-source toolkit for lava flow simulations

    Science.gov (United States)

    Mossoux, Sophie; Feltz, Adelin; Poppe, Sam; Canters, Frank; Kervyn, Matthieu

    2014-05-01

    Lava flow hazard modeling is a useful tool for scientists and stakeholders confronted with imminent or long term hazard from basaltic volcanoes. It can improve their understanding of the spatial distribution of volcanic hazard, influence their land use decisions and improve the city evacuation during a volcanic crisis. Although a range of empirical, stochastic and physically-based lava flow models exists, these models are rarely available or require a large amount of physical constraints. We present a GIS toolkit which models lava flow propagation from one or multiple eruptive vents, defined interactively on a Digital Elevation Model (DEM). It combines existing probabilistic (VORIS) and deterministic (FLOWGO) models in order to improve the simulation of lava flow spatial spread and terminal length. Not only is this toolkit open-source, running in Python, which allows users to adapt the code to their needs, but it also allows users to combine the models included in different ways. The lava flow paths are determined based on the probabilistic steepest slope (VORIS model - Felpeto et al., 2001) which can be constrained in order to favour concentrated or dispersed flow fields. Moreover, the toolkit allows including a corrective factor in order for the lava to overcome small topographical obstacles or pits. The lava flow terminal length can be constrained using a fixed length value, a Gaussian probability density function or can be calculated based on the thermo-rheological properties of the open-channel lava flow (FLOWGO model - Harris and Rowland, 2001). These slope-constrained properties allow estimating the velocity of the flow and its heat losses. The lava flow stops when its velocity is zero or the lava temperature reaches the solidus. Recent lava flows of Karthala volcano (Comoros islands) are here used to demonstrate the quality of lava flow simulations with the toolkit, using a quantitative assessment of the match of the simulation with the real lava flows. The

  8. Biomineralization and biosignatures of coralloid-type speleothems from lava tubes of Galapagos Islands: evidences on the fossil record of prokaryotes

    Science.gov (United States)

    Miller, Ana Z.; Garcia-Sanchez, Angela M.; Pereira, Manuel F. C.; Gazquez, Fernando; Calaforra, José M.; Forti, Paolo; Toulkeridis, Theofilos; Martínez-Frías, Jesús; Saiz-Jimenez, Cesareo

    2016-04-01

    Lava tubes have traditionally been considered of little interest from a mineralogical point of view. Recently, this type of volcanic caves has received particular attention because lava tubes have been described on Mars. Speleothems, or secondary mineral deposits in lava tubes are mainly composed of siliceous minerals. Coralloid-type speleothems are found either on basaltic cave walls or on the surface of other speleothems. Several authors attribute a microbially mediated origin to their formation. This type of speleothems was recorded within Royal Palm Cave of Santa Cruz Island in Galapagos Archipelago (Ecuador), a lava tube 600 m long, 5 to 15 m height and 2 to 10 m width. The Galapagos Islands are an archipelago of 19 volcanic islands located some 1500 km west of Ecuador, in the Pacific Ocean. These islands host one of the most biodiverse settings on Earth, studied by Charles Darwin. Beige and greyish small coralloids were collected in Royal Palm Cave and analysed by field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDS), X-ray micro-computed tomography (micro-CT) and mineralogical analyses for morphological, 3D microstructural and compositional characterization, as well as for assessing microbe-mineral interactions and biogenicity. In addition, 16S rRNA gene analyses were performed to identify microbial communities associated with the coralloid-type speleothems. The coralloids showed internal compositional zonation along the growth direction of the speleothems, according to micro-CT data. Internal layering was clearly discernable by the differences in opacity of the distinct mineralogical phases to X-rays, being dominated by alteration products of siliceous composition, whereas more opaque phases, usually Ca-rich minerals, were dominant in the outermost part of the speleothems. X-ray diffraction and infrared spectroscopy reinforced that the first stage of deposition is mainly composed of opal A and clay minerals

  9. In Vitro Conservation of Some Threatened and Economically Important Ferns Belonging to the Indian Subcontinent

    Directory of Open Access Journals (Sweden)

    Shastri P. Shukla

    2014-01-01

    Full Text Available This study was undertaken to identify methods of mass multiplication for five ornamental, economically important ferns (Nephrolepis biserrata (Sw. Schott., N. cordifolia cv. ‘‘duffii’’ (L. Presl., N. exaltata cv. bostoniensis (L. Schott., Pteris vittata L., and Cyclosorus dentatus Link., and three threatened ferns, namely, Cyathea spinulosa Wall. ex. Hook, Pityrogramma calomelanos (L. Link., and Microsorum punctatum (L. Schott., through in vitro techniques. Collections were made from different biodiversity zones of India including Northeast Himalayas, Kumaon Himalayas, and Western Ghat and successfully introduced and grown in a fern-house. Aseptic cultures were raised at the morphogenic level of callus, axillary shoot, multiple shoot, and rooted plants. An optimized medium is described for each fern species. Plantlets were also produced from spore culture of Cyathea spinulosa and successfully hardened under fern house conditions.

  10. Crowdfunding the Azolla fern genome project: a grassroots approach.

    Science.gov (United States)

    Li, Fay-Wei; Pryer, Kathleen M

    2014-01-01

    Much of science progresses within the tight boundaries of what is often seen as a "black box". Though familiar to funding agencies, researchers and the academic journals they publish in, it is an entity that outsiders rarely get to peek into. Crowdfunding is a novel means that allows the public to participate in, as well as to support and witness advancements in science. Here we describe our recent crowdfunding efforts to sequence the Azolla genome, a little fern with massive green potential. Crowdfunding is a worthy platform not only for obtaining seed money for exploratory research, but also for engaging directly with the general public as a rewarding form of outreach.

  11. A Gompertz regression model for fern spores germination

    Directory of Open Access Journals (Sweden)

    Gabriel y Galán, Jose María

    2015-06-01

    Full Text Available Germination is one of the most important biological processes for both seed and spore plants, also for fungi. At present, mathematical models of germination have been developed in fungi, bryophytes and several plant species. However, ferns are the only group whose germination has never been modelled. In this work we develop a regression model of the germination of fern spores. We have found that for Blechnum serrulatum, Blechnum yungense, Cheilanthes pilosa, Niphidium macbridei and Polypodium feuillei species the Gompertz growth model describe satisfactorily cumulative germination. An important result is that regression parameters are independent of fern species and the model is not affected by intraspecific variation. Our results show that the Gompertz curve represents a general germination model for all the non-green spore leptosporangiate ferns, including in the paper a discussion about the physiological and ecological meaning of the model.La germinación es uno de los procesos biológicos más relevantes tanto para las plantas con esporas, como para las plantas con semillas y los hongos. Hasta el momento, se han desarrollado modelos de germinación para hongos, briofitos y diversas especies de espermatófitos. Los helechos son el único grupo de plantas cuya germinación nunca ha sido modelizada. En este trabajo se desarrolla un modelo de regresión para explicar la germinación de las esporas de helechos. Observamos que para las especies Blechnum serrulatum, Blechnum yungense, Cheilanthes pilosa, Niphidium macbridei y Polypodium feuillei el modelo de crecimiento de Gompertz describe satisfactoriamente la germinación acumulativa. Un importante resultado es que los parámetros de la regresión son independientes de la especie y que el modelo no está afectado por variación intraespecífica. Por lo tanto, los resultados del trabajo muestran que la curva de Gompertz puede representar un modelo general para todos los helechos leptosporangiados

  12. Effect of synthetic detergents on germination of fern spores

    Energy Technology Data Exchange (ETDEWEB)

    Devi, Y.; Devi, S.

    1986-12-01

    Synthetic detergents constitute one of the most important water pollutants by contaminating the lakes and rivers through domestic and industrial use. Considerable information is now available for the adverse effects of detergents an aquatic fauna including fish, algae, and higher aquatic plants. Marked inhibition of germination in orchids and brinjals and of seedlings growth in raddish suggest that rapidly growing systems could be sensitive to detergent polluted water. The present study of the effect of linear alkyl benzene sulphonate on germination of the spores of a fern, Diplazium esculentum aims at the understanding of the effects of water pollution on pteridophytes and the development of spore germination assay for phytoxicity evaluation.

  13. Monitoring of Radon in Tourist Part of Skocjan Caves

    Science.gov (United States)

    Debevec Gerjevic, Vanja; Jovanovic, Peter

    2010-05-01

    Due to their exceptional significance for cultural and natural heritage, the Škocjan Caves were entered on UNESCO's list of natural and cultural world heritage sites in 1986. Park Škocjan Caves is located in South Eastern part of Slovenia. It was established with aim of conserving and protecting exceptional geomorphological, geological and hydrological outstanding features, rare and endangered plant and animal species, paleontological and archaeological sites, ethnological and architectural characteristics and cultural landscape and for the purpose of ensuring opportunities for suitable development, by the National Assembly of the Republic of Slovenia in 1996. Park Škocjan Caves established monitoring that includes caves microclimate parameters: humidity, CO2, wind flow and radon concentration and daughter products. The approach in managing the working place with natural background radiation is complex. Monitoring of Radon has been functioning for more than ten years now. Presentation will show the yearly dynamic observed in the different parts of the caves, related to radon daughter products and other microclimatic data, beside the most convenient measuring technique. Implementing the Slovene legislation in the field of radiation protection, we are obligated to perform special measurements in the caves and also having our guides and workers in the caves regularly examined according to established procedure. The medical exams are performed at Institution of Occupational Safety, Ljubljana in order to monitor the influence of Radon to the workers in the cave. The equivalent dose for each employed person is also established on regular basis and it is part of medical survey of workers in the caves. The survey will be described along with education of the staff working in the caves in the field of radiation protection. An overview of Slovene legislation with practical example on implementation will be demonstrated in the case of Škocjan Caves where the managing

  14. Ultrasonic synthesis of fern-like ZnO nanoleaves and their enhanced photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Qing Lan [School of Mathematics and Physics, Changzhou University, Jiangsu 213164 (China); School of Electronics and Information, Nantong University, Jiangsu 226019 (China); Xiong, Rui [School of Physics and Technology, Wuhan University, Hubei 430072 (China); Zhai, Bao-gai [School of Mathematics and Physics, Changzhou University, Jiangsu 213164 (China); Huang, Yuan Ming, E-mail: dongshanisland@126.com [School of Mathematics and Physics, Changzhou University, Jiangsu 213164 (China)

    2015-01-01

    Graphical abstract: - Highlights: • Fern-like ZnO nanoleaves were synthesized by ultrasonicating Zn microcrystals in water. • A fern-like ZnO nanoleaf is a self-assembly of ZnO nanoplates along one ZnO nanorod. • Fern-like ZnO nanoleaves exhibit enhanced photocatalytic activity than ZnO nanocrystals. • The branched hierarchical structures are responsible for the enhanced photocatalytic activity. - Abstract: Two-dimensional fern-like ZnO nanoleaves were synthesized by ultrasonicating zinc microcrystals in water. The morphology, crystal structure, optical property and photocatalytic activity of the fern-like ZnO nanoleaves were characterized with scanning electron microscopy, X-ray diffraction, transmission electron microscopy, photoluminescence spectroscopy and ultraviolet–visible spectroscopy, respectively. It is found that one fern-like ZnO nanoleaf is composed of one ZnO nanorod as the central trunk and a number of ZnO nanoplates as the side branches in opposite pairs along the central ZnO nanorod. The central ZnO nanorod in the fern-like nanoleaves is about 1 μm long while the side-branching ZnO nanoplates are about 100 nm long and 20 nm wide. Further analysis has revealed that ZnO nanocrystals are the building blocks of the central ZnO nanorod and the side-branching ZnO nanoplates. Under identical conditions, fern-like ZnO nanoleaves exhibit higher photocatalytic activity in photodegrading methyl orange in aqueous solution than spherical ZnO nanocrystals. The first-order photocatalytic rate constant of the fern-like ZnO nanoleaves is about four times as large as that of the ZnO nanoparticles. The branched architecture of the hierarchical nanoleaves is suggested be responsible for the enhanced photocatalytic activity of the fern-like ZnO nanoleaves.

  15. Field Detection of Chemical Assimilation in A Basaltic Lava Flow

    Science.gov (United States)

    Young, K. E.; Bleacher, J. E.; Needham, D. H.; Evans, C. A.; Whelley, P. L.; Scheidt, S. P.; Williams, D. A.; Rogers, A. D.; Glotch, T.

    2017-01-01

    Lava channels are features seen throughout the inner Solar System, including on Earth, the Moon, and Mars. Flow emplacement is therefore a crucial process in the shaping of planetary surfaces. Many studies, including some completed by members of this team at the December 1974 lava flow, have investigated the dynamics of lava flow emplacement, both on Earth and on the Moon and how pre-flow terrain can impact final channel morphology, but far fewer have focused on how the compositional characteristics of the substrate over which a flow was em-placed influenced its final flow morphology. Within the length of one flow, it is common for flows to change in morphology, a quality linked to rheology (a function of multiple factors including viscosi-ty, temperature, composition, etc.). The relationship between rheology and temperature has been well-studied but less is known about the relationship between an older flow's chemistry and how the interaction between this flow and the new flow might affect lava rheology and therefore emplacement dynamics. Lava erosion. Through visual observations of active terrestrial flows, mechanical erosion by flowing lava has been well-documented. Lava erosion by which flow composition is altered as the active lava melts and assimilates the pre-flow terrain over which it moves is also hypothesized to affect channel formation. However, there is only one previous field study that geochemically documents the process in recent basaltic flow systems.

  16. Lava Inundation Zone Maps for Mauna Loa, Island of Hawaiʻi, Hawaii

    Science.gov (United States)

    Trusdell, Frank A.; Zoeller, Michael H.

    2017-10-12

    Lava flows from Mauna Loa volcano, on the Island of Hawaiʻi, constitute a significant hazard to people and property. This report addresses those lava flow hazards, mapping 18 potential lava inundation zones on the island.

  17. Carbon dioxide budgets in cave air and carbon in speleothems; insights from a shallow cave in Ireland

    Science.gov (United States)

    McDermott, Frank; Phillips, Dominika

    2017-04-01

    The conventional view that hydrological inputs (e.g. drip-water degassing) comprise the dominant source of cave air CO2 has been challenged by recent studies that emphasise the importance of direct advection of gaseous CO2from above and beneath cave voids (e.g. 'soil air' and 'ground air'). A better understanding of CO2 gas budgets in caves is important, not only for the correct interpretation of δ13C values and 14C activity data in speleothems, but also for an understanding of the wider role of karst in the global carbon cycle as a source or sink of atmospheric CO2. This study presents new results from a combined air-temperature and CO2 monitoring programme at a small multi-chamber cave in SE Ireland (Ballynamintra cave, Co. Waterford), building on an earlier study at this cave (Baldini et al., 2006). Episodic, low-amplitude but temporally coherent diurnal-scale cave air temperature fluctuations detected almost simultaneously by a series of temperature loggers within the cave were used to detect air mass advection. The sequence and pattern of temperature fluctuations at different locations within the cave enabled the identification of discrete air-inflow and air-outflow events. These diurnal-scale events occur episodically throughout the year in the winter/ spring and summer/autumn temperature ventilation regimes of the cave. Importantly, changes in cave air pCO2 values recorded by an infra-red logger located in the inner chamber a few metres from the back of the cave occur contemporaneously with the air-mass displacement events, and are consistent with direct advection of CO2-rich soil air via fractures in the subjacent cave roof and walls. In the winter regime, episodic diurnal-scale air outflow events draw CO2-rich air over the logger, resulting in short-lived pulses of air, typically containing c. 0.7% CO2 (by volume), several times the ambient cave air CO2 values at this site. Similar events occur during the summer/autumn thermal regime, but these reach

  18. Regional Similarity of Leveed Lava Flows on the Mars Plains

    Science.gov (United States)

    Baloga, Steve M.; Glaze, Lori, S.

    2008-01-01

    The dynamics of lava flow movement are controlled by the fluid interior. Crust, solids, and nondeformable material can only retard the advance or spreading of a lava flow. Figure 1 shows a typical large, channelized lava flow found on the Mars plains. It has been suggested in [I] that such large leveed flows on the Mars plains were emplaced by a balance between the formation and shedding of crust as the flow advances. For the prototypical flow north of Pavonis Mons (Fig. I), such a balance leads to a flow morphology that approximately self-replicates at all locations along the flow path [2,3]. Moreover, most quantitative characteristics of emplacement (e.g., viscosity, volumetric flow rate) of the prototype flow at Pavonis Mons resembled those of large channelized lava flows on Earth. The exception was the relatively long, sustained supply of lava, on the order of a year as opposed to hours or days for terrestrial analogs.

  19. World Register of marine Cave Species (WoRCS: a new Thematic Species Database for marine and anchialine cave biodiversity

    Directory of Open Access Journals (Sweden)

    Vasilis Gerovasileiou

    2016-09-01

    Full Text Available Scientific exploration of marine cave environments and anchialine ecosystems over recent decades has led to outstanding discoveries of novel taxa, increasing our knowledge of biodiversity. However, biological research on underwater caves has taken place only in a few areas of the world and relevant information remains fragmented in isolated publications and databases. This fragmentation makes assessing the conservation status of marine cave species especially problematic, and this issue should be addressed urgently given the stresses resulting from planned and rampant development in the coastal zone worldwide. The goal of the World Register of marine Cave Species (WoRCS initiative is to create a comprehensive taxonomic and ecological database of known species from marine caves and anchialine systems worldwide and to present this as a Thematic Species Database (TSD of the World Register of marine Species (WoRMS. WoRCS will incorporate ecological data (e.g., type of environment, salinity regimes, and cave zone as well as geographical information on the distribution of species in cave and anchialine environments. Biodiversity data will be progressively assembled from individual database sources at regional, national or local levels, as well as from literature sources (estimate: >20,000 existing records of cave-dwelling species scattered in several databases. Information will be organized in the WoRCS database following a standard glossary based on existing terminology. Cave-related information will be managed by the WoRCS thematic editors with all data dynamically linked to WoRMS and its team of taxonomic editors. In order to mobilize data into global biogeographic databases, a Gazetteer of the Marine and Anchialine Caves of the World will be established. The presence records of species could be eventually georeferenced for submission to the Ocean Biogeographic Information System (OBIS and constitute an important dataset for biogeographical and

  20. 36 CFR 7.36 - Mammoth Cave National Park.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Mammoth Cave National Park. 7.36 Section 7.36 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.36 Mammoth Cave National Park. (a)...

  1. Aspergillosis of the Petrous Apex and Meckel's Cave

    OpenAIRE

    Ederies, Ash; Chen, Joseph; Aviv, Richard I.; Pirouzmand, Farhad; Bilbao, Juan M.; Thompson, Andrew L.; Symons, Sean P.

    2010-01-01

    Cranial cerebral aspergillosis is a rare entity in immunocompetent patients. Invasive disease involving the petrous apex and Meckel's cave has rarely been described. We present a case of localized invasive petrous apical and Meckel's cave disease in an immunocompetent patient who presented with hemicranial neuralgic pain.

  2. Meckel's cave epidermoid with trigeminal neuralgia: CT findings.

    Science.gov (United States)

    Kapila, A; Steinbaum, S; Chakeres, D W

    1984-12-01

    An epidermoid tumor of Meckel's cave was found in a middle-aged woman with trigeminal neuralgia. On CT the lesion had negative attenuation numbers of fat and extended from an expanded Meckel's cave through the porous trigeminus into the ambient and cerebellopontine angle cisterns. Surgical excision provided relief of the patient's trigeminal neuralgia.

  3. Aspergillosis of the Petrous Apex and Meckel's Cave.

    Science.gov (United States)

    Ederies, Ash; Chen, Joseph; Aviv, Richard I; Pirouzmand, Farhad; Bilbao, Juan M; Thompson, Andrew L; Symons, Sean P

    2010-05-01

    Cranial cerebral aspergillosis is a rare entity in immunocompetent patients. Invasive disease involving the petrous apex and Meckel's cave has rarely been described. We present a case of localized invasive petrous apical and Meckel's cave disease in an immunocompetent patient who presented with hemicranial neuralgic pain.

  4. Intratentorial lipomas with Meckel's cave and cerebellopontine angle extension.

    Science.gov (United States)

    Ruocco, M J; Robles, H A; Rao, K C; Armonda, R A; Ondra, S L

    1995-08-01

    An unusual case of bilateral intratentorial lipomas with extension into Meckel's caves and the cerebellopontine angle is described. Surgical and histopathologic correlation demonstrate that the lipoma encased the trigeminal nerve in Meckel's caves. The origin of the lipoma from the anteromedial margins of the tentorium is discussed and correlated with a recently proposed theory for the development of intracranial lipomas.

  5. Bioaccumulation of eight heavy metals in cave animals from Dashui ...

    African Journals Online (AJOL)

    ajl2

    Eight heavy metals content in the dominant animal groups, soil and water in Malang and Dashui caves ... Dashui cave is situated in the urban zone of Guiyang City, Guizhou, and Guizhou Aluminum ... cient of a metal in animal suggests higher absorption capacity of ... Pb, As, Cd and Hg, respectively, while the ranking of.

  6. 36 CFR 7.68 - Russell Cave National Monument.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Russell Cave National Monument. 7.68 Section 7.68 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.68 Russell Cave National Monument. (a...

  7. Geologic history of the Black Hills caves, South Dakota

    Science.gov (United States)

    Palmer, Arthur N.; Palmer, Margaret; Paces, James B.

    2016-01-01

    Cave development in the Madison aquifer of the Black Hills has taken place in several stages. Mississippian carbonates first underwent eogenetic (early diagenetic) reactions with interbedded sulfates to form breccias and solution voids. Later subaerial exposure allowed oxygenated meteoric water to replace sulfates with calcite and to form karst and small caves. All were later buried by ~2 km of Pennsylvanian–Cretaceous strata.

  8. Geochemical Stratigraphy of Southern Parana' Lava Piles

    Science.gov (United States)

    Marzoli, A.; De Min, A.; Marques, L. S.; Nardy, A.; Chiaradia, M.

    2015-12-01

    Basaltic lava flows of the Paranà Large Igneous Province exhibit significant regional and stratigraphic geochemical variations. While the most notable difference concerns the dominance of low-Ti (TiO2 Esmeralda low-Ti basalts (these latter being present both towards the base and the top of the sequence) in Paranà State, while in Santa Caterina State Gramado flows are interlayered with Urubici-type high-Ti basalts. The interlayering of distinct basaltic magma type requires near-synchronous eruption of chemically strongly different magma types generated from clearly heterogeneous mantle sources and erupted through separated magma plumbing systems, without apparent interaction (mixing) among the distinct basalts. In conclusion, the relative timing of low- and high-Ti magma types seems to be much more complicated than previously thought, as for example Esmeralda or Pitanga basalts, previously considered as quite late and postdating Gramado basalts, are indeed synchronous with them.

  9. The Longevity of Lava Dome Eruptions

    CERN Document Server

    Wolpert, Robert L; Calder, Eliza S

    2015-01-01

    Understanding the duration of past, on-going and future volcanic eruptions is an important scientific goal and a key societal need. We present a new methodology for forecasting the duration of on-going and future lava dome eruptions based on a database (DomeHaz) recently compiled by the authors. The database includes duration and composition for 177 such eruptions, with "eruption" defined as the period encompassing individual episodes of dome growth along with associated quiescent periods during which extrusion pauses but unrest continues. In a key finding we show that probability distributions for dome eruption durations are both heavy-tailed and composition-dependent. We construct Objective Bayes statistical models featuring heavy-tailed Generalized Pareto distributions with composition-specific parameters to make forecasts about the durations of new and on-going eruptions that depend on both eruption duration-to-date and composition. Our Bayesian predictive distributions reflect both uncertainty about mode...

  10. Moonshot Laboratories' Lava Relief Google Mapping Project

    Science.gov (United States)

    Brennan, B.; Tomita, M.

    2016-12-01

    The Moonshot Laboratories were conceived at the University Laboratory School (ULS) on Oahu, Hawaii as way to develop creative problem solvers able to resourcefully apply 21st century technologies to respond to the problems and needs of their communities. One example of this was involved students from ULS using modern mapping and imaging technologies to assist peers who had been displaced from their own school in Pahoe on the Big Island of Hawaii. During 2015, lava flows from the eruption of Kilauea Volcano were slowly encroaching into the district of Puna in 2015. The lava flow was cutting the main town of Pahoa in half, leaving no safe routes of passage into or out of the town. One elementary school in the path of the flow was closed entirely and a new one was erected north of the flow for students living on that side. Pahoa High School students and teachers living to the north were been forced to leave their school and transfer to Kea'au High School. These students were separated from friends, family and the community they grew up in and were being thrust into a foreign environment that until then had been their local rival. Using Google Mapping technologies, Moonshot Laboratories students created a dynamic map to introduce the incoming Pahoa students to their new school in Kea'au. Elements included a stylized My Maps basemap, YouTube video descriptions of the building, videos recorded by Google Glass showing first person experiences, and immersive images of classrooms were created using 360 cameras. During the first day of orientation at Kea'au for the 200 Pahoa students, each of them were given a tablet to view the map as they toured and got to know their new campus. The methods and technologies, and more importantly innovative thinking, used to create this map have enormous potential for how to educate all students about the world around us, and the issues facing it. http://www.moonshotincubator.com/

  11. Evolution of leaf form in marsileaceous ferns: evidence for heterochrony.

    Science.gov (United States)

    Pryer, Kathleen M; Hearn, David J

    2009-02-01

    Using an explicit phylogenetic framework, ontogenetic patterns of leaf form are compared among the three genera of marsileaceous ferns (Marsilea, Regnellidium, and Pilularia) with the outgroup Asplenium to address the hypothesis that heterochrony played a role in their evolution. We performed a Fourier analysis on a developmental sequence of leaves from individuals of these genera. Principal components analysis of the harmonic coefficients was used to characterize the ontogenetic trajectories of leaf form in a smaller dimensional space. Results of this study suggest that the "evolutionary juvenilization" observed in these leaf sequences is best described using a mixed model of heterochrony (accelerated growth rate and early termination at a simplified leaf form). The later stages of the ancestral, more complex, ontogenetic pattern were lost in Marsileaceae, giving rise to the simplified adult leaves of Marsilea, Regnellidium, and Pilularia. Life-history traits such as ephemeral and uncertain habitats, high reproductive rates, and accelerated maturation, which are typical for marsileaceous ferns, suggest that they may be "r strategists." The evidence for heterochrony presented here illustrates that it has resulted in profound ecological and morphological consequences for the entire life history of Marsileaceae.

  12. Development of the gametophyte of the fern Schizaea pusilla

    Science.gov (United States)

    Kiss, J. Z.; Swatzell, L. J.

    1996-01-01

    Schizaea pusilla is a pteridophyte with several unique developmental characteristics. In contrast to most other fern species, S. pusilla gametophytes remain filamentous throughout their development, and the gametophytes are associated with an endophytic fungus which appears to be mycorrhizal. In terms of tropistic responses, apical filament cells of young gametophytes are negatively phototropic compared with germ filaments of other ferns which exhibit positive phototropism. Cryofixation (propane jet freezing and high-pressure freezing) in conjunction with freeze substitution electron microscopy was used to study young gametophytes. The results demonstrate that apical filament cells have a distinctive structural polarity and that rhizoids also can be successfully frozen by these methods. The cytoskeleton and endomembrane system were particularly well preserved in cryofixed cells. In addition, Schizaea gametophytes were used as a test system to evaluate potential artifacts of propane jet freezing and high pressure freezing. There was little apparent difference in ultrastructure between cells cryofixed by either freezing method. These gametophytes will be useful in determining the effectiveness of cryofixation techniques and as a model system in tip growth studies.

  13. Detection of chlorophylls in spores of seven ferns.

    Science.gov (United States)

    Tseng, Mei-Hwei; Lin, Kuei-Huei; Huang, Yi-Jia; Chang, Ya-Lan; Huang, Sheng-Cih; Kuo, Li-Yaung; Huang, Yao-Moan

    2017-03-01

    Fern spores were traditionally classified into chlorophyllous (green) and nonchlorophyllous (nongreen) types based on the color visible to the naked eye. Recently, a third type, "cryptochlorophyllous spores", is recognized, and these spores are nongreen under white light but contain chlorophylls. Epifluorescence microscopy was previously used to detect chlorophylls in cryptochlorophyllous spores. In addition to epifluorescence microscopy, current study performed some other approaches, including spore-squash epifluorescence, absorption spectra, laser-induced fluorescence emission spectra, thin layer chromatography (TLC), and ultra-high performance liquid chromatography with ultraviolet and mass spectrometric detection (UHPLC-UV-MS) in order to detect chlorophylls of spores of seven ferns (Sphaeropteris lepifera, Ceratopteris thalictroides, Leptochilus wrightii, Leptochilus pothifolius, Lepidomicrosorum buergerianum, Osmunda banksiifolia, and Platycerium grande). Destructive methods, such as TLC and UHPLC-UV-MS, successfully detected chlorophylls inside the spores when their signals of red fluorescence under epifluorescence microscope were masked by spore wall. Although UHPLC-UV-MS analysis was the most sensitive and reliable for determining the chlorophylls of spores, spore-squash epifluorescence is not only reliable but also cost- and time-effective one among our study methods. In addition, we first confirmed that Lepidomicrosorium buergerianum, Leptochilus pothifolius, Leptochilus wrightii, and Platycerium grande, produce cryptochlorophyllous spores.

  14. A free-access online key to identify Amazonian ferns

    Directory of Open Access Journals (Sweden)

    Gabriela Zuquim

    2017-03-01

    Full Text Available There is urgent need for more data on species distributions in order to improve conservation planning. A crucial but challenging aspect of producing high-quality data is the correct identification of organisms. Traditional printed floras and dichotomous keys are difficult to use for someone not familiar with the technical jargon. In poorly known areas, such as Amazonia, they also become quickly outdated as new species are described or ranges extended. Recently, online tools have allowed developing dynamic, interactive, and accessible keys that make species identification possible for a broader public. In order to facilitate identifying plants collected in field inventories, we developed an internet-based free-access tool to identify Amazonian fern species. We focused on ferns, because they are easy to collect and their edaphic affinities are relatively well known, so they can be used as an indicator group for habitat mapping. Our key includes 302 terrestrial and aquatic entities mainly from lowland Amazonian forests. It is a free-access key, so the user can freely choose which morphological features to use and in which order to assess them. All taxa are richly illustrated, so specimens can be identified by a combination of character choices, visual comparison, and written descriptions. The identification tool was developed in Lucid 3.5 software and it is available at http://keyserver.lucidcentral.org:8080/sandbox/keys.jsp.

  15. Invariant Hough Random Ferns for Object Detection and Tracking

    Directory of Open Access Journals (Sweden)

    Yimin Lin

    2014-01-01

    Full Text Available This paper introduces an invariant Hough random ferns (IHRF incorporating rotation and scale invariance into the local feature description, random ferns classifier training, and Hough voting stages. It is especially suited for object detection under changes in object appearance and scale, partial occlusions, and pose variations. The efficacy of this approach is validated through experiments on a large set of challenging benchmark datasets, and the results demonstrate that the proposed method outperforms state-of-the-art conventional methods such as bounding-box-based and part-based methods. Additionally, we also propose an efficient clustering scheme based on the local patches’ appearance and their geometric relations that can provide pixel-accurate, top-down segmentations from IHRF back-projections. This refined segmentation can be used to improve the quality of online object tracking because it avoids the drifting problem. Thus, an online tracking framework based on IHRF, which is trained and updated in each frame to distinguish and segment the object from the background, is established. Finally, the experimental results on both object segmentation and long-term object tracking show that this method yields accurate and robust tracking performance in a variety of complex scenarios, especially in cases of severe occlusions and nonrigid deformations.

  16. Petrographic and geochemical study on cave pearls from Kanaan Cave (Lebanon

    Directory of Open Access Journals (Sweden)

    Nader Fadi H.

    2007-01-01

    Full Text Available The Kanaan cave is situated at the coastal zone, north of Beirut City (capital of Lebanon. The cave is located within the upper part of the Jurassic Kesrouane Formation (Liassic to Oxfordian which consists mainly of micritic limestone. Twenty seven cave pearls were subjected to petrographic (conventional and scanning electron microscopy and geochemical analyses (major/trace elements and stable isotopes. The cave pearls were found in an agitated splash-pool with low mud content. They are believed to have formed through chemical precipitation of calcite in water over-saturated with calcium. The nucleus and micritic laminae show δ18OV-PDB values of about -5.0‰ and δ13C V-PDB values of -11.8‰, while the surrounding calcite spar laminae resulted in δ18OV-PDB ranging between -5.3 and -5.2‰, and δ13C V-PDB between -12.3 and -12.1‰. A genesis/diagenesis model for these speleothems is proposed involving recrystallization which has selectively affected the inner layers of the cave pearls. This is chiefly invoked by sparry calcite crystals ‘invading’ the inner micrite cortical laminae and the nuclei (cross-cutting the pre-existing mud-envelopes, and the slight depletion in δ18O values from inner to outer cortical layers. The calculated δ18OV-SMOW of the water (-4.2‰ matches with data on meteoric water signature for the central eastern Mediterranean region.

  17. Terrestrial cave invertebrates of the Vrachanska Planina Mountains

    Directory of Open Access Journals (Sweden)

    PETAR BERON

    2016-05-01

    Full Text Available The modern biospeleological research in Bulgaria started in 1921 in the Ledenika Cave. From 65 caves of “Vrachanski Balkan” Nature Park and its surroundings have been recorded a total of 218 species of terrestrial invertebrates, including 32 species of troglobionts, most of them endemic to Vrachanska Planina Mts. (including the caves near Lakatnik: Isopoda Oniscoidea – 4, Chilopoda – 1, Diplopoda – 5, Opiliones – 2, Pseudoscorpiones – 3, Araneae – 3, Collembola – 2, Diplura – 2, Coleoptera, Carabidae – 7, Coleoptera, Leiodidae – 3. Troglobites are known from 51 caves, the richest being the caves near Lakatnik (Temnata dupka - 10, Zidanka - 7, Razhishkata dupka - 5, Svinskata dupka - 6, Kozarskata peshtera - 5, near Vratsa (Ledenika - 11, Barkite 8 - 5, Belyar - 6, Toshova dupka near Glavatsi - 6 and others.

  18. Adenocarcinoma of Meckel's cave: case report.

    Science.gov (United States)

    Tacconi, L; Arulampalam, T; Johnston, F; Symon, L

    1995-12-01

    A rare localization of adenocarcinoma in Meckel's cave is reported in a 58-year-old woman, who had a 5-month history of pain and altered sensation in the second division of the left trigeminal nerve. Removal of the lesion was achieved by a subtemporal route. Histology showed this to be an adenocarcinoma. The patient underwent investigations for a primary tumor; the investigations were all negative, and the patient was subsequently treated with a course of radiotherapy. At 4-month follow-up, there was no evidence of recurrence, and she remains symptomatically well. The various mechanisms of secondary localization are discussed.

  19. Similarities in basalt and rhyolite lava flow emplacement processes

    Science.gov (United States)

    Magnall, Nathan; James, Mike; Tuffen, Hugh; Vye-Brown, Charlotte

    2016-04-01

    Here we use field observations of rhyolite and basalt lava flows to show similarities in flow processes that span compositionally diverse lava flows. The eruption, and subsequent emplacement, of rhyolite lava flows is currently poorly understood due to the infrequency with which rhyolite eruptions occur. In contrast, the emplacement of basaltic lava flows are much better understood due to very frequent eruptions at locations such as Mt Etna and Hawaii. The 2011-2012 eruption of Cordón Caulle in Chile enabled the first scientific observations of the emplacement of an extensive rhyolite lava flow. The 30 to 100 m thick flow infilled a topographic depression with a negligible slope angle (0 - 7°). The flow split into two main channels; the southern flow advanced 4 km while the northern flow advanced 3 km before stalling. Once the flow stalled the channels inflated and secondary flows or breakouts formed from the flow front and margins. This cooling rather than volume-limited flow behaviour is common in basaltic lava flows but had never been observed in rhyolite lava flows. We draw on fieldwork conducted at Cordón Caulle and at Mt Etna to compare the emplacement of rhyolite and basaltic flows. The fieldwork identified emplacement features that are present in both lavas, such as inflation, breakouts from the flow font and margins, and squeeze-ups on the flow surfaces. In the case of Cordón Caulle, upon extrusion of a breakout it inflates due to a combination of continued lava supply and vesicle growth. This growth leads to fracturing and breakup of the breakout surface, and in some cases a large central fracture tens of metres deep forms. In contrast, breakouts from basaltic lava flows have a greater range of morphologies depending on the properties of the material in the flows core. In the case of Mt Etna, a range of breakout morphologies are observed including: toothpaste breakouts, flows topped with bladed lava as well as breakouts of pahoehoe or a'a lava. This

  20. Urang Cave Karst Environmental Development, as Tourism Object

    Directory of Open Access Journals (Sweden)

    Srijono Srijono

    2013-12-01

    Full Text Available Karst environment become an alternative tourist destination as well as to boost local revenues. In karst environments in Grobogan District, Central Java Province, formed Urang Cave, with an interesting endokarst phenomenon. This study aims to do zoning district Urang Cave as tourist sites. The research method is using contour maps as a base map of Urang Cave karst environment geomorphological mapping. Geomorphological data processing is using ArcView GIS 3.3 program. Land use map refers to RBI, scale 1:25.000. Geomorphological analysis refers to the Ministry of Energy and Mineral Resources No. 1456.K/20/MEM/2000, and petrography. Each development zone is analyzed its geophysical environmental element, then set scoring and value summation. For comprehensive environmental element analysis, chemical analysis of rocks, and water-soil chemistry. In reference to Minister of Energy Mineral Resource decrees No. 1456/K/20/MEM/2000, Urang Cave zoning defined into 3 (three zone, as follow: the Protected Zone, Cultivation Zone 1, and Cultivation Zone 2. Protected Zone, consists of Urang Cave tunnel/hallway with a unique spheleothem in it. This zone as a cave tracking site tourism, potential to produce karst water as a decent drinking water while maintaining hardness. Cultivation Zone 1 is spreading about 200 m in distance from outer appearance of spring around the cave hallway. In this zone mining of cave sediments may be done in the inactive form caves, without changing the state of the existing major exokarst morphology. Cultivation Zone 2, an outer zone, located farthest from the tunnel/hallway Urang Cave. Utilization of this zone as a limestone mining quarry, although only on a small scale.

  1. World Register of marine Cave Species (WoRCS): a new Thematic Species Database for marine and anchialine cave biodiversity

    NARCIS (Netherlands)

    Gerovasileiou, Vasilis; Martínez, Alejandro; Álvarez, Fernando; Boxshall, Geoff; Humphreys, William F.; Jaume, Damià; Becking, L.E.; Muricy, Guilherme; Hengstum, van Peter J.; Dekeyzer, Stefanie; Decock, Wim; Vanhoorne, Bart; Vandepitte, Leen; Bailly, Nicolas; Iliffe, Thomas M.

    2016-01-01

    Scientific exploration of marine cave environments and anchialine ecosystems over recent decades has led to outstanding discoveries of novel taxa, increasing our knowledge of biodiversity. However, biological research on underwater caves has taken place only in a few areas of the world and relevant

  2. Ecological and evolutionary consequences of desiccation tolerance in tropical fern gametophytes.

    Science.gov (United States)

    Watkins, James E; Mack, Michelle C; Sinclair, Thomas R; Mulkey, Stephen S

    2007-01-01

    Ferns have radiated into the same diverse environments as spermatophytes, and have done so with an independent gametophyte that is not protected by the parent plant. The degree and extent of desiccation tolerance (DT) in the gametophytes of tropical fern species was assessed to understand mechanisms that have allowed ferns to radiate into a diversity of habitats. Species from several functional groups were subjected to a series of desiccation events, including varying degrees of intensity and multiple desiccation cycles. Measurements of chlorophyll fluorescence were used to assess recovery ability and compared with species ecology and gametophyte morphology. It is shown that vegetative DT (rare in vascular plants) is widely exhibited in fern gametophytes and the degree of tolerance is linked to species habitat preference. It is proposed that gametophyte morphology influences water-holding capacity, a novel mechanism that may help to explain how ferns have radiated into drought-prone habitats. Fern gametophytes have often been portrayed as extreme mesophytes with little tolerance for desiccation. The discovery of DT in gametophytes holds potential for improving our understanding of both the controls on fern species distribution and their evolution. It also advances a new system with which to study the evolution of DT in vascular plants.

  3. Ultrasonic synthesis of fern-like ZnO nanoleaves and their enhanced photocatalytic activity

    Science.gov (United States)

    Ma, Qing Lan; Xiong, Rui; Zhai, Bao-gai; Huang, Yuan Ming

    2015-01-01

    Two-dimensional fern-like ZnO nanoleaves were synthesized by ultrasonicating zinc microcrystals in water. The morphology, crystal structure, optical property and photocatalytic activity of the fern-like ZnO nanoleaves were characterized with scanning electron microscopy, X-ray diffraction, transmission electron microscopy, photoluminescence spectroscopy and ultraviolet-visible spectroscopy, respectively. It is found that one fern-like ZnO nanoleaf is composed of one ZnO nanorod as the central trunk and a number of ZnO nanoplates as the side branches in opposite pairs along the central ZnO nanorod. The central ZnO nanorod in the fern-like nanoleaves is about 1 μm long while the side-branching ZnO nanoplates are about 100 nm long and 20 nm wide. Further analysis has revealed that ZnO nanocrystals are the building blocks of the central ZnO nanorod and the side-branching ZnO nanoplates. Under identical conditions, fern-like ZnO nanoleaves exhibit higher photocatalytic activity in photodegrading methyl orange in aqueous solution than spherical ZnO nanocrystals. The first-order photocatalytic rate constant of the fern-like ZnO nanoleaves is about four times as large as that of the ZnO nanoparticles. The branched architecture of the hierarchical nanoleaves is suggested be responsible for the enhanced photocatalytic activity of the fern-like ZnO nanoleaves.

  4. Physiological mechanisms drive differing foliar calcium content in ferns and angiosperms.

    Science.gov (United States)

    Funk, Jennifer L; Amatangelo, Kathryn L

    2013-09-01

    Recent evidence points to ferns containing significantly lower contents of foliar calcium and other cations than angiosperms. This is especially true of more ancient 'non-polypod' fern lineages, which predate the diversification of angiosperms. Calcium is an important plant nutrient, the lack of which can potentially slow plant growth and litter decomposition, and alter soil invertebrate communities. The physiological mechanisms limiting foliar calcium (Ca) content in ferns are unknown. While there is a lot we do not know about Ca uptake and transport in plants, three physiological processes are likely to be important. We measured transpiration rate, cation exchange capacity, and leaching loss to determine which process most strongly regulates foliar Ca content in a range of fern and co-occurring understory angiosperm species from a montane Hawaiian rainforest. We found higher instantaneous and lifetime (corrected for leaf lifespan) transpiration rates in angiosperms relative to ferns. Ferns preferentially incorporated Ca into leaves relative to strontium, which suggests that root or stem cation exchange capacity differs between ferns and angiosperms, potentially affecting calcium transport in plants. There were no differences in foliar Ca leaching loss between groups. Among the physiological mechanisms measured, foliar Ca was most strongly correlated with leaf-level transpiration rate and leaf lifespan. This suggests that inter-specific differences in a leaf's lifetime transpiration may play a significant role in determining plant nutrition.

  5. Horizontal transfer of an adaptive chimeric photoreceptor from bryophytes to ferns.

    Science.gov (United States)

    Li, Fay-Wei; Villarreal, Juan Carlos; Kelly, Steven; Rothfels, Carl J; Melkonian, Michael; Frangedakis, Eftychios; Ruhsam, Markus; Sigel, Erin M; Der, Joshua P; Pittermann, Jarmila; Burge, Dylan O; Pokorny, Lisa; Larsson, Anders; Chen, Tao; Weststrand, Stina; Thomas, Philip; Carpenter, Eric; Zhang, Yong; Tian, Zhijian; Chen, Li; Yan, Zhixiang; Zhu, Ying; Sun, Xiao; Wang, Jun; Stevenson, Dennis W; Crandall-Stotler, Barbara J; Shaw, A Jonathan; Deyholos, Michael K; Soltis, Douglas E; Graham, Sean W; Windham, Michael D; Langdale, Jane A; Wong, Gane Ka-Shu; Mathews, Sarah; Pryer, Kathleen M

    2014-05-06

    Ferns are well known for their shade-dwelling habits. Their ability to thrive under low-light conditions has been linked to the evolution of a novel chimeric photoreceptor--neochrome--that fuses red-sensing phytochrome and blue-sensing phototropin modules into a single gene, thereby optimizing phototropic responses. Despite being implicated in facilitating the diversification of modern ferns, the origin of neochrome has remained a mystery. We present evidence for neochrome in hornworts (a bryophyte lineage) and demonstrate that ferns acquired neochrome from hornworts via horizontal gene transfer (HGT). Fern neochromes are nested within hornwort neochromes in our large-scale phylogenetic reconstructions of phototropin and phytochrome gene families. Divergence date estimates further support the HGT hypothesis, with fern and hornwort neochromes diverging 179 Mya, long after the split between the two plant lineages (at least 400 Mya). By analyzing the draft genome of the hornwort Anthoceros punctatus, we also discovered a previously unidentified phototropin gene that likely represents the ancestral lineage of the neochrome phototropin module. Thus, a neochrome originating in hornworts was transferred horizontally to ferns, where it may have played a significant role in the diversification of modern ferns.

  6. Reliability analysis of the velocity matching of coal cutting and caving in fully mechanized top-coal caving face

    Institute of Scientific and Technical Information of China (English)

    罗善明; 缪协兴

    2002-01-01

    The matching relationship between coal cutting and caving in fully mechanized top-coal caving face is analyzed in detail from the angle of reliability. The coupling equation of reliability is established correspondingly, and the mathematical equation of the coefficient of velocity matching of coal cutting and caving is obtained, which meets a certain reliability demand for making the working procedure of coal caving not influence coal cutting of coal-cutter. The results show that the relationship between the coefficient of the velocity matching and the reliability of coal cutting and caving system is linear on the whole when R<0.9. It is pointed out that different numerical value should be selected for different coal face according to different demand for reliability.

  7. Tree fern trunks facilitate seedling regeneration in a productive lowland temperate rain forest.

    Science.gov (United States)

    Gaxiola, Aurora; Burrows, Larry E; Coomes, David A

    2008-03-01

    Seedling regeneration on forest floors is often impaired by competition with established plants. In some lowland temperate rain forests, tree fern trunks provide safe sites on which tree species establish, and grow large enough to take root in the ground and persist. Here we explore the competitive and facilitative effects of two tree fern species, Cyathea smithii and Dicksonia squarrosa, on the epiphytic regeneration of tree species in nutrient-rich alluvial forests in New Zealand. The difficulties that seedlings have in establishing on vertical tree fern trunks were indicated by the following observations. First, seedling abundance was greatest on the oldest sections of tree fern trunks, near the base, suggesting that trunks gradually recruited more and more seedlings over time, but many sections of trunk were devoid of seedlings, indicating the difficulty of establishment on a vertical surface. Second, most seedlings were from small-seeded species, presumably because smaller seeds can easily lodge on tree fern trunks. Deer browsing damage was observed on 73% of epiphytic seedlings growing within 2 m of the ground, whereas few seedlings above that height were browsed. This suggests that tree ferns provide refugia from introduced deer, and may slow the decline in population size of deer-preferred species. We reasoned that tree ferns would compete with epiphytic seedlings for light, because below the tree fern canopy photosynthetically active radiation (PAR) was about 1% of above-canopy PAR. Frond removal almost tripled %PAR on the forest floor, leading to a significant increase in the height growth rate (HGR) of seedlings planted on the forest floor, but having no effects on the HGRs of epiphytic seedlings. Our study shows evidence of direct facilitative interactions by tree ferns during seedling establishment in plant communities associated with nutrient-rich soils.

  8. Radon as a natural tracer for underwater cave exploration.

    Science.gov (United States)

    Csondor, Katalin; Erőss, Anita; Horváth, Ákos; Szieberth, Dénes

    2017-07-01

    The Molnár János cave is one of the largest hypogenic caves of the Buda Thermal Karst (Budapest, Hungary) and mainly characterized by water-filled passages. The major outflow point of the waters of the cave system is the Boltív spring, which feeds the artificial Malom Lake. Previous radon measurements in the cave system and in the spring established the highest radon concentration (71 BqL(-1)) in the springwater. According to previous studies, the origin of radon was identified as iron-hydroxide containing biofilms, which form where there is mixing of cold and thermal waters, and these biofilms efficiently adsorb radium from the thermal water component. Since mixing of waters is responsible for the formation of the cave as well, these iron-hydroxide containing biofilms and the consequent high radon concentrations mark the active cave forming zones. Based on previous radon measurements, it is supposed that the active mixing and cave forming zone has to be close to the spring, since the highest radon concentration was measured there. Therefore radon mapping was carried out with the help of divers in order to get a spatial distribution of radon in the cave passages closest to the spring. Based on our measurements, the highest radon activity concentration (84 BqL(-1)) was found in the springwater. Based on the distribution of radon activity concentrations, direct connection was established between the spring and the István-room of the cave, which was verified by an artificial tracer. However, the distribution of radon in the cave passages shows lower concentrations (18-46 BqL(-1)) compared to the spring, therefore an additional deep inflow from hitherto unknown cave passages is assumed, from which waters with high radon content arrive to the spring. These passages are assumed to be in the active cave formation zone. This study proved that radon activity concentration distribution is a useful tool in underwater cave exploration. Copyright © 2016 Elsevier Ltd. All

  9. THE DIVERSITY OF EPIPHYTIC FERN ON THE OIL PALM TREE (Elaeis guineensis Jacq. IN PEKANBARU, RIAU

    Directory of Open Access Journals (Sweden)

    Nery Sofiyanti

    2015-02-01

    Full Text Available Oil palm (Elaeis guineensis is one  main commodity in Riau Province. Morphologically, the trunk of oil palm  has suitable environment for the growth of epiphytic fern, due to its broaden base of petiole that may accumulate organic and anorganic debrish. The objective of this study was to investigate the diversity of epiphytic fern on the oil palm tree. A total of 125 oil palm trees from seven  study sites in Pekanbaru, Riau were observed. The number of epiphytic ferns identified in this study was 16 species belongs to six families.

  10. Heat transfer measurements of the 1983 kilauea lava flow.

    Science.gov (United States)

    Hardee, H C

    1983-10-07

    Convective heat flow measurements of a basaltic lava flow were made during the 1983 eruption of Kilauea volcano in Hawaii. Eight field measurements of induced natural convection were made, giving heat flux values that ranged from 1.78 to 8.09 kilowatts per square meter at lava temperatures of 1088 and 1128 degrees Celsius, respectively. These field measurements of convective heat flux at subliquidus temperatures agree with previous laboratory measurements in furnace-melted samples of molten lava, and are useful for predicting heat transfer in magma bodies and for estimating heat extraction rates for magma energy.

  11. Comparative analysis between Payen and Daedalia Planum lava fields

    Science.gov (United States)

    Giacomini, Lorenza; Massironi, Matteo; Pasquarè, Giorgio; Carli, Cristian; Martellato, Elena; Frigeri, Alessandro; Cremonese, Gabriele; Bistacchi, Andrea; Federico, Costanzo

    The Payen volcanic complex is a large Quaternary fissural structure belonging to the back-arc extensional area of the Andes in the Mendoza Province (Argentina). From the eastern portion of this volcanic structure huge pahoehoe lava flows were emitted, extending more than 180 km from the feeding vents. These huge flows propagated over the nearly flat surface of the Pampean foreland (ca 0.3° slope). The very low viscosity of the olivine basalt lavas, coupled with the inflation process are the most probable explanation for their considerable length. In an inflation process a thin viscoelastic crust, produced at an early stage, is later inflated by the underlying fluid core, which remains hot and fluid thanks to the thermal-shield effect of the crust. The inflation shows some typical morphological fingerprints like tumuli, lava lobes, lava rises and lava ridges. In order to compare the morphology of the Argentinean Payen flows with lava flows on Mars, MOLA, THEMIS, MOC, MRO/HIRISE, and MEX/OMEGA data have been analysed, providing a multi-scale characterisation of Martian flows. Mars Global Surveyor/MOLA data were used to investigate the topographic environment over which flows propagated on Mars in order to detect very low angle slopes where possibly inflation processes could have developed. Then Mars Odyssey/THEMIS and Mars Global Surveyor's MOC data were used to detect Martian lava flows with inflation "fingerprints", whereas OMEGA data were used to obtain some inferences about their composition. Finally the MRO/HIRISE images recently acquired, can provide further details and constraints on surface morphologies and lava fronts. All these data were used to analyze Daedalia Planum lava field, at about 300 km southwest of Arsia Mons, and clear morphological similarities with the longest flows of the Payen lava fields were found. These striking morphological analogies suggest that inflation process is quite common also for the Daedalia field. This is also supported by

  12. Under the volcano: phylogeography and evolution of the cave-dwelling Palmorchestia hypogaea (Amphipoda, Crustacea at La Palma (Canary Islands

    Directory of Open Access Journals (Sweden)

    Oromí Pedro

    2008-01-01

    Full Text Available Abstract Background The amphipod crustacean Palmorchestia hypogaea occurs only in La Palma (Canary Islands and is one of the few terrestrial amphipods in the world that have adapted to a strictly troglobitic life in volcanic cave habitats. A surface-dwelling closely related species (Palmorchestia epigaea lives in the humid laurel forest on the same island. Previous studies have suggested that an ancestral littoral Orchestia species colonized the humid forests of La Palma and that subsequent drought episodes in the Canaries reduced the distribution of P. epigaea favouring the colonization of lava tubes through an adaptive shift. This was followed by dispersal via the hypogean crevicular system. Results P. hypogaea and P. epigaea did not form reciprocally monophyletic mitochondrial DNA clades. They showed geographically highly structured and genetically divergent populations with current gene flow limited to geographically close surface locations. Coalescence times using Bayesian estimations assuming a non-correlated relaxed clock with a normal prior distribution of the age of La Palma, together with the lack of association of habitat type with ancestral and recent haplotypes, suggest that their adaptation to cave life is relatively ancient. Conclusion The data gathered here provide evidence for multiple invasions of the volcanic cave systems that have acted as refuges. A re-evaluation of the taxonomic status of the extant species of Palmorchestia is needed, as the division of the two species by habitat and ecology is unnatural. The information obtained here, and that from previous studies on hypogean fauna, shows the importance of factors such as the uncoupling of morphological and genetic evolution, the role of climatic change and regressive evolution as key processes in leading to subterranean biodiversity.

  13. Stability Assessment of Natural Caves Using Empirical Approaches and Rock Mass Classifications

    Science.gov (United States)

    Jordá-Bordehore, L.

    2017-08-01

    The stability of underground voids such as caves can be assessed, in an initial approximation, by geomechanical classifications such as the Barton Q index. From a geomechanical viewpoint, the stability of 137 large span natural caves was analyzed herein. The caves were graphically represented based on existing tunnel and underground graphs, according to width and rock quality index Q. Many natural caves analyzed by a tunnel-type engineering approach could result as apparently unstable when represented in empirical existing graphics and would require reinforcements incompatible with speleothems and large chamber heights. A new graph and equation are proposed herein for the maximum span, for the exclusive case of caves, resulting in a reliable representation of large stable natural caves. The main contribution is a new stability chart for natural caves, consisting of two zones: a zone where stable caves are represented and a zone where unstable caves and collapsed caves are located.

  14. Numerical and Experimental Approaches Toward Understanding Lava Flow Heat Transfer

    Science.gov (United States)

    Rumpf, M.; Fagents, S. A.; Hamilton, C.; Crawford, I. A.

    2013-12-01

    We have performed numerical modeling and experimental studies to quantify the heat transfer from a lava flow into an underlying particulate substrate. This project was initially motivated by a desire to understand the transfer of heat from a lava flow into the lunar regolith. Ancient regolith deposits that have been protected by a lava flow may contain ancient solar wind, solar flare, and galactic cosmic ray products that can give insight into the history of our solar system, provided the records were not heated and destroyed by the overlying lava flow. In addition, lava-substrate interaction is an important aspect of lava fluid dynamics that requires consideration in lava emplacement models Our numerical model determines the depth to which the heat pulse will penetrate beneath a lava flow into the underlying substrate. Rigorous treatment of the temperature dependence of lava and substrate thermal conductivity and specific heat capacity, density, and latent heat release are imperative to an accurate model. Experiments were conducted to verify the numerical model. Experimental containers with interior dimensions of 20 x 20 x 25 cm were constructed from 1 inch thick calcium silicate sheeting. For initial experiments, boxes were packed with lunar regolith simulant (GSC-1) to a depth of 15 cm with thermocouples embedded at regular intervals. Basalt collected at Kilauea Volcano, HI, was melted in a gas forge and poured directly onto the simulant. Initial lava temperatures ranged from ~1200 to 1300 °C. The system was allowed to cool while internal temperatures were monitored by a thermocouple array and external temperatures were monitored by a Forward Looking Infrared (FLIR) video camera. Numerical simulations of the experiments elucidate the details of lava latent heat release and constrain the temperature-dependence of the thermal conductivity of the particulate substrate. The temperature-dependence of thermal conductivity of particulate material is not well known

  15. Vision-mediated interaction with the Nottingham caves

    Science.gov (United States)

    Ghali, Ahmed; Bayomi, Sahar; Green, Jonathan; Pridmore, Tony; Benford, Steve

    2003-05-01

    The English city of Nottingham is widely known for its rich history and compelling folklore. A key attraction is the extensive system of caves to be found beneath Nottingham Castle. Regular guided tours are made of the Nottingham caves, during which castle staff tell stories and explain historical events to small groups of visitors while pointing out relevant cave locations and features. The work reported here is part of a project aimed at enhancing the experience of cave visitors, and providing flexible storytelling tools to their guides, by developing machine vision systems capable of identifying specific actions of guides and/or visitors and triggering audio and/or video presentations as a result. Attention is currently focused on triggering audio material by directing the beam of a standard domestic flashlight towards features of interest on the cave wall. Cameras attached to the walls or roof provide image sequences within which torch light and cave features are detected and their relative positions estimated. When a target feature is illuminated the corresponding audio response is generated. We describe the architecture of the system, its implementation within the caves and the results of initial evaluations carried out with castle guides and members of the public.

  16. Strategies for Creating Prescribed Hydraulic Fractures in Cave Mining

    Science.gov (United States)

    He, Q.; Suorineni, F. T.; Oh, J.

    2017-04-01

    The cave mining method was traditionally applied to massive low-grade, weak orebodies at shallow depths (less than 500 m) that favour cave propagation under gravity. Currently, this method is being applied to stronger orebodies and is taking place at depths of up to 2000 m below the surface. To ensure continuous cave propagation, preconditioning of the orebody is essential in this latter caving environment to improve rock mass caveability and to decrease fragmentation sizes. Hydraulic fracturing was initiated in the oil industry and is now being used in the cave mining industry as a preconditioning method and for stalled caves reactivation. A limitation of conventional hydraulic fracturing in the cave mining industry is that the hydraulic fracture orientation is uncontrollable and is dictated by the minimum in situ stress orientation. The preconditioning effectiveness of orientation-uncontrollable hydraulic fractures is limited in some geotechnical conditions, and the concept of creating orientation-controllable hydraulic fractures, here termed prescribed hydraulic fractures, is proposed to fill this gap. In this paper, the feasibility of the proposed approaches to creating prescribed hydraulic fractures is presented based on previous studies and numerical modelling. The numerical modelling code reliability in simulating the hydraulic fracture propagation and reorientation process was validated by comparing with laboratory results in the reported literature. In addition, the sensitivity of the prescribed hydraulic fracturing to the in situ stress condition and rock mass properties is examined.

  17. Radon in the Creswell Crags Permian limestone caves

    Energy Technology Data Exchange (ETDEWEB)

    Gillmore, G.K. E-mail: g.k.gillmore@bradford.ac.uk; Phillips, P.S.; Denman, A.R.; Gilbertson, D.D

    2002-07-01

    An investigation of radon levels in the caves of Creswell Crags, Derbyshire, an important Site of Special Scientific Interest (SSSI) shows that the Lower Magnesian Limestone (Permian) caves have moderate to raised radon gas levels (27-7800 Bq m{sup -3}) which generally increase with increasing distance into the caves from the entrance regions. This feature is partly explained in terms of cave ventilation and topography. While these levels are generally below the Action Level in the workplace (400 Bq m{sup -3} in the UK), they are above the Action Level for domestic properties (200 Bq m{sup -3}). Creswell Crags has approximately 40,000 visitors per year and therefore a quantification of effective dose is important for both visitors and guides to the Robin Hood show cave. Due to short exposure times the dose received by visitors is low (0.0016 mSv/visit) and regulations concerning exposure are not contravened. Similarly, the dose received by guides is fairly low (0.4 mSv/annum) due in part to current working practice. However, the risk to researchers entering the more inaccessible areas of the cave system is higher (0.06 mSv/visit). This survey also investigated the effect of seasonal variations on recorded radon concentration. From this work summer to winter ratios of between 1.1 and 9.51 were determined for different locations within the largest cave system.

  18. Radon in the creswell crags Permian limestone caves.

    Science.gov (United States)

    Gillmore, G K; Phillips, P S; Denman, A R; Gilbertson, D D

    2002-01-01

    An investigation of radon levels in the caves of Creswell Crags, Derbyshire, an important Site of Special Scientific Interest (SSSI) shows that the Lower Magnesian Limestone (Permian) caves have moderate to raised radon gas levels (27-7800 Bq m(-3)) which generally increase with increasing distance into the caves from the entrance regions. This feature is partly explained in terms of cave ventilation and topography. While these levels are generally below the Action Level in the workplace (400 Bq m(-3) in the UK), they are above the Action Level for domestic properties (200 Bq m(-3)). Creswell Crags has approximately 40,000 visitors per year and therefore a quantification of effective dose is important for both visitors and guides to the Robin Hood show cave. Due to short exposure times the dose received by visitors is low (0.0016 mSv/visit) and regulations concerning exposure are not contravened. Similarly, the dose received by guides is fairly low (0.4 mSv/annum) due in part to current working practice. However, the risk to researchers entering the more inaccessible areas of the cave system is higher (0.06 mSv/visit). This survey also investigated the effect of seasonal variations on recorded radon concentration. From this work summer to winter ratios of between 1.1 and 9.51 were determined for different locations within the largest cave system.

  19. Species Diversity and Food-web Complexity in the Caves of Malaysia

    OpenAIRE

    Liz Price

    2014-01-01

    Besides microbes a wide variety of cave animals inhabit various caves of Malaysia, ranging from tiny invertebrates through to small mammals, reptiles, amphibians and bats. Evidence even supports the visitation of elephants to some caves. In the present report the food web complexity and the species diversity that exist in Malaysian caves is described on the basis of direct sightings. Furthermore, the major threats to the present status of such caves are also discussed.

  20. Species Diversity and Food-web Complexity in the Caves of Malaysia

    Directory of Open Access Journals (Sweden)

    Liz Price

    2014-10-01

    Full Text Available Besides microbes a wide variety of cave animals inhabit various caves of Malaysia, ranging from tiny invertebrates through to small mammals, reptiles, amphibians and bats. Evidence even supports the visitation of elephants to some caves. In the present report the food web complexity and the species diversity that exist in Malaysian caves is described on the basis of direct sightings. Furthermore, the major threats to the present status of such caves are also discussed.

  1. Water-clover ferns, Marsilea, in the Southeastern United States

    Science.gov (United States)

    Jacono, Colette C.; Johnson, David M.

    2006-01-01

    A surge in the collection of exotic Marsilea, M. mutica, M. minuta and M. hirsuta in the southeastern United States has prompted the need for updated identification aids. This study provides an annotated key to all water-clover ferns occurring in the region. It describes and illustrates recently documented exotic species and a previously misidentified western introduction. It details the rediscovery of M. ancylopoda, presumed extinct, and confirms its identification as the western species M. oligospora. Finally it clarifies the status and distribution of two additional western North American species introduced to the southeast, M. vestita and M. macropoda.

  2. 美国紧急修补Fern Ridge坝

    Institute of Scientific and Technical Information of China (English)

    郑国良; 范友军

    2005-01-01

    俄勒冈州正在从美国联邦政府寻求4200万美元的紧急资金以修补Fem Ridge坝。2004年12月,美国陆军工程师团(USACE)将大坝的库水位降低了13.5m。降低库水位是由于发现有越来越多的泥沙从大坝的渗流集水沟流出。一个由USACE召集的独立调查委员会得出结论说,因管涌和/或内部侵蚀的原因,63a坝龄的Fern Ridge坝正处于溃坝的活跃状态,水库水位高程应当限制在110m以下,

  3. Macedonio Fernández: la forma de la experiencia

    Directory of Open Access Journals (Sweden)

    Mónica Bueno

    2015-10-01

    Full Text Available Podemos supor que, Macedonio Fernández, escritor da vanguardia argentina, constrói uma noção de experiência que descreve de uma maneira singular a relação vida/literatura. Museo de la Novela de la Eterna, sua novela “boa” (assim ele a chamava, não só narra a tensão entre o real e o ficcional senão que é um procedimento básico de construção do não-real, do que ainda não é, no sentido blochiano, e o conhecimento da experiência de Macedonio parece funcionar nessa perspectiva utópica.

  4. Application of Random Ferns for non-planar object detection

    Science.gov (United States)

    Mastov, Alexey; Konovalenko, Ivan; Grigoryev, Anton

    2015-12-01

    The real time object detection task is considered as a part of a project devoted to development of autonomous ground robot. This problem has been successfully solved with Random Ferns algorithm, which belongs to keypoint-based method and uses fast machine learning algorithms for keypoint matching step. As objects in the real world are not always planar, in this article we describe experiments of applying this algorithm for non-planar objects. Also we introduce a method for fast detection of a special class of non-planar objects | those which can be decomposed into planar parts (e.g. faces of a box). This decomposition needs one detector for each side, which may significantly affect speed of detection. Proposed approach copes with it by omitting repeated steps for each detector and organizing special queue of detectors. It makes the algorithm three times faster than naive one.

  5. The fern cavitation catapult: mechanism and design principles.

    Science.gov (United States)

    Llorens, C; Argentina, M; Rojas, N; Westbrook, J; Dumais, J; Noblin, X

    2016-01-01

    Leptosporangiate ferns have evolved an ingenious cavitation catapult to disperse their spores. The mechanism relies almost entirely on the annulus, a row of 12-25 cells, which successively: (i) stores energy by evaporation of the cells' content, (ii) triggers the catapult by internal cavitation, and (iii) controls the time scales of energy release to ensure efficient spore ejection. The confluence of these three biomechanical functions within the confines of a single structure suggests a level of sophistication that goes beyond most man-made devices where specific structures or parts rarely serve more than one function. Here, we study in detail the three phases of spore ejection in the sporangia of the fern Polypodium aureum. For each of these phases, we have written the governing equations and measured the key parameters. For the opening of the sporangium, we show that the structural design of the annulus is particularly well suited to inducing bending deformations in response to osmotic volume changes. Moreover, the measured parameters for the osmoelastic design lead to a near-optimal speed of spore ejection (approx. 10 m s(-1)). Our analysis of the trigger mechanism by cavitation points to a critical cavitation pressure of approximately -100 ± 14 bar, a value that matches the most negative pressures recorded in the xylem of plants. Finally, using high-speed imaging, we elucidated the physics leading to the sharp separation of time scales (30 versus 5000 µs) in the closing dynamics. Our results highlight the importance of the precise tuning of the parameters without which the function of the leptosporangium as a catapult would be severely compromised.

  6. Phylogeny and historical biogeography of the lastreopsid ferns (Dryopteridaceae).

    Science.gov (United States)

    Labiak, Paulo H; Sundue, Michael; Rouhan, Germinal; Hanks, Judith G; Mickel, John T; Moran, Robbin C

    2014-07-01

    • Premise of the study: As currently circumscribed, Lastreopsis has about 45 species and occurs in Australia, southern Asia, Africa, Madagascar, and the neotropics. Previous molecular phylogenetic studies suggested that Lastreopsis is paraphyletic. Our study focuses on resolving relationships among the lastreopsid ferns (Lastreopsis, Megalastrum, and Rumohra), the evolution of morphological characters, and an understanding of the temporal and spatial patterns that have led to the current diversity and geographical distribution of its extant species.• Methods: Phylogenetic relationships were recovered under Bayesian, maximum likelihood, and maximum parsimony methods, using a data set of four plastid markers. Divergence time estimates were made using BEAST, and the biogeographic hypotheses were tested under the DEC model and the RASP/S-DIVA methods.• Key results: Lastreopsis was recovered as paraphyletic, and at least one of its clades should be recognized as a distinct genus, Parapolystichum. Coveniella poecilophlebia and Oenotrichia tripinnata were nested within Lastreopsis s.s., Megalastrum and Rumohra as sister to the Lastreopsis s.s., and the Lastreopsis amplissima clades. The initial diversification of the lastreopsids took place at about 56.55 Ma, from a neotropical ancestor.• Conclusions: Taxonomic recognition of Parapolystichum is warranted to preserve the monophyly of Lastreopsis. Diversification among the main clades of the lastreopsid ferns was influenced by climatic and geological changes in the southern hemisphere. The biogeographic history of the group is intimately related to the trans-Antarctic corridor between Australia and South America, with evidence for multiple lineage interchanges between Australia and South America during the Oligocene and the Eocene epochs.

  7. Rockbolting in gateroads of top coal caving longwall faces

    Energy Technology Data Exchange (ETDEWEB)

    Xiu, Z. [SCT Ltd. (China); Jiang, J. [Yanzhou Coal Mining Co. Ltd. (China)

    2004-07-01

    This paper presents technology development of rockbolting in gateroads of top coal caving longwall faces in Yanzhou. The development work has been concentrated on understanding behaviour of gateroads of top coal caving longwalls; introducing a monitoring based feedback design approach; upgrading rockbolting consumables and equipment; optimisation of rockbolting practice; development of effective supplemental reinforcement technique; and last but not the least, establishment of necessary legal framework such as consumables standards and practice guidelines. The paper then highlights aspects of future development work with rockbolting in gateroads of top coal caving longwall faces, such as integrated cutting/bolting cycle for higher drivage rate.

  8. Do cave features affect underground habitat exploitation by non-troglobite species?

    Science.gov (United States)

    Lunghi, Enrico; Manenti, Raoul; Ficetola, Gentile Francesco

    2014-02-01

    Many biospeleological studies focus on organisms that are exclusive inhabitants of the subterranean realm, but organisms that are not obligate cave-dwellers are frequent in caves, and may account for a substantial portion of biomass. Moreover, several taxa that are usually epigeous are regularly found inside caves, but for most of them it is unknown whether they accidentally enter them, or whether they actively select caves for specific environmental features. In this study we analysed the community of non-strict cave-dwelling organisms (amphibians, gastropods, spiders and orthopterans) in 33 caves from Central Italy, to assess how environmental factors determine community structure. Cave features strongly affected the distribution of the taxa considered. The combined effect of cave morphology and microclimate explained nearly 50% of the variation of community structure. Most of community variation occurred along a gradient from deep, dark and humid caves, to dry caves with wider entrances and extended photic areas. Most of species were associated with humid, deep and dark caves. Most of the non-troglobiont amphibians and invertebrates did not occur randomly in caves, but were associated to caves with specific environmental features. Analysing relationships between cave-dwelling species and environmental variables can allow a more ecological and objective classification of cave-dwelling organisms.

  9. Calcite Farming at Hollow Ridge Cave: Calibrating Net Rainfall and Cave Microclimate to Dripwater and Calcite Chemical Variability

    Science.gov (United States)

    Tremaine, D. M.; Kilgore, B. P.; Froelich, P. N.

    2012-04-01

    Stable isotope (δ18O and δ13C) and trace element records in cave speleothems are often interpreted as climate changes in rainfall amount or source, cave air temperature, overlying vegetation and atmospheric pCO2. However, these records are difficult to verify without in situ calibration of changes in cave microclimate (e.g., net rainfall, interior ventilation changes) to contemporaneous variations in dripwater and speleothem chemistry. In this study at Hollow Ridge Cave (HRC) in Marianna, Florida (USA), cave dripwater, bedrock, and modern calcite (farmed in situ) were collected in conjunction with continuous cave air pCO2, temperature, barometric pressure, relative humidity, radon-222 activity, airflow velocity and direction, rainfall amount, and drip rate data [1]. We analyzed rain and dripwater δD and δ18O, dripwater Ca2+, pH, δ13C and TCO2, cave air pCO2 and δ13C, and farmed calcite δ18O and δ13C to examine the relationships among rainwater isotopic composition, cave air ventilation, cave air temperature, calcite growth rate and seasonal timing, and calcite isotopic composition. Farmed calcite δ13C decreases linearly with distance from the front entrance to the interior of the cave during all seasons, with a maximum entrance-to-interior gradient of Δδ13C = -7‰ . A whole-cave "Hendy test" at distributed contemporaneous farming sites reveals that ventilation induces a +1.9 ± 0.96‰ δ13C offset between calcite precipitated in a ventilation flow path and out of flow paths. Farmed calcite δ18O exhibits a +0.82 ± 0.24‰ offset from values predicted by both theoretical calcite-water calculations and by laboratory-grown calcite [2]. Unlike calcite δ13C, oxygen isotopes show no ventilation effects and are a function only of temperature. Combining our data with other speleothem studies, we find a new empirical relationship for cave-specific water-calcite oxygen isotope fractionation across a range of temperatures and cave environments: 1000 ln α = 16

  10. The microwave palaeointensity technique and its application to lava

    CERN Document Server

    Hill, M J

    2000-01-01

    application is required at each power step thus removing the need for accurate reproducibility of absorbed microwave power and also reducing experimental time. This method as well as a previous method developed for use with ceramic samples are described and discussed. The microwave palaeointensity technique has been used successfully in three palaeomagnetic studies (that include rock magnetic and directional analyses). These are a study of historic lava from Mt. Etna, Sicily, a detailed through the flow study of the 1960 Kilauea lava flow, Hawaii and a study of Tertiary Australian lava. Palaeointensity results are compared to observatory records and / or results of previous studies using conventional techniques. The research undertaken, described in this thesis, demonstrates that the microwave palaeointensity technique is a viable technique for use with lava. This enables greater confidence that any palaeointensity results obtained are not affected by sample alteration during experimentation. The suitability ...

  11. Spatial organization and connectivity of caves

    Science.gov (United States)

    Jouves, Johan; Viseur, Sophie; Guglielmi, Yves; Camus, Hubert

    2015-04-01

    The main particularity of karst systems is their hierarchical organization as three-dimensional network of conduits behaving as drain. They are recognized as having a major influence on fluid flow at reservoir scale. However, a karstic network is generally hardly continuously observable and their great intrinsic heterogeneity makes their characterization very complex. This media can be only observed by speleological investigation, conditioned to human possibilities. As a result, only few parts can be observed and therefore it is required to model the non-observable parts for reservoir characterizations. To provide realistic 3D models, non-observable karstic features will be generated using parameters extracted from observed ones. Morphometric analysis of the three-dimensional karstic network provides quantitative measures that can (i) give information on speleogenesis processes, (ii) be used to compare different karst systems, (iii) be correlated with hydrogeological behavior and (iii) control the simulation of realistic karst networks. Recent work done on the subject characterize the karstic network as a whole, without genetic a-priori. However, most of observable caves appears to have a polygenic history due to modifications in boundary conditions and some different karst features can be observed in a same cavity. To study the geometrical organization of caves, we propose to analyze 3D speleological topographies for which speleogenetic context is known. This way, it is possible to characterize karst features according to speleogenetic processes. Several morphometric descriptors have been calculated on three-dimensional topographies provided by speleological works. Some parameters describe the existence of preferential direction of karstification and preferential flow paths, other parameters describe the complexity, geometry and connectivity of the three-dimensional karstic networks. Through the study of fifteen different caves, 150km of 3D data have been analyzed

  12. Management plan for the Aleutian shield fern on Adak Island, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The endangered Aleutian shield fern, Polystichum aleuticum is known from only two locations, Atka and Adak islands in the Aleutian Islands, Alaska (Lipkin 1985),...

  13. New combinations of the fern genus Tectaria (Tectariaceae) for the Flora of China.

    OpenAIRE

    Christenhusz, Maarten

    2010-01-01

    For studies on the fern family Tectariaceae for the Flora of China, four species previously treated as Ctenitopsis need new combinations in Tectaria. The new combinations are proposed here and information on their types is provided.

  14. Using a Microscale Approach to Rapidly Separate and Characterize Three Photosynthetic Pigment Species from Fern

    Science.gov (United States)

    Ayudhya, Theppawut Israsena Na; Posey, Frederick T.; Tyus, Jessica C.; Dingra, Nin N.

    2015-01-01

    A rapid separation of three photosynthetic pigments (chlorophyll "a" and "b" and xanthophyll) from fern ("Polystichum acrostichoides") is described using microscale solvent extraction and traditional thin layer chromatography that minimizes use of harmful chemicals and lengthy procedures. The experiment introduces…

  15. Stable detection of expanded target by the use of boosting random ferns

    Science.gov (United States)

    Deng, Li; Wang, Chunhong; Rao, Changhui

    2012-10-01

    This paper studies the problem of keypoints recognition of extended target which lacks of texture information, and introduces an approach of stable detection of these targets called boosting random ferns (BRF). As common descriptors in this circumstance do not work as well as usual cases, matching of keypoints is hence turned into classification task so as to make use of the trainable characteristic of classifier. The kernel of BRF is consisted of random ferns as the classifier and AdaBoost (Adaptive Boosting) as the frame so that accuracy of random ferns classifier can be boosted to a relatively high level. Experiments compare BRF with widely used SURF descriptor and single random ferns classifier. The result shows that BRF obtains higher recognition rate of keypoints. Besides, for image sequence, BRF provides stronger stability than SURF in target detection, which proves the efficiency of BRF aiming to extended target which lacks of texture information.

  16. Primary oxidation variation and distribution of uranium and thorium in a lava flow.

    Science.gov (United States)

    Watkins, N D; Holmes, C W; Haggerty, S E

    1967-02-03

    An Icelandic basalt lava flow has a systematic oxidation variation, formed during the initial cooling, with a resultant maximum oxidation just below the center of the lava. The ratio of thorium to uranium shows a clear dependence on this primary oxidation variation. Between-lava comparisons of thorium and uranium may be critically dependent on the position of the samples in each lava.

  17. Deposition of calcium carbonate in karst caves: role of bacteria in Stiffe's cave.

    Directory of Open Access Journals (Sweden)

    Ercole Claudia

    2001-01-01

    Full Text Available Bacteria make a significant contribution to the accumulation of carbonate in several natural habitats where large amounts of carbonates are deposited. However, the role played by microbial communities in speleothem formation (stalactites, stalagmites etc. in caves is still unclear. In bacteria carbonate is formed by autotrophic pathways, which deplete CO2 from the environment, and by heterotrophic pathways, leading to active or passive precipitation. We isolated cultivable heterotrophic microbial strains, able to induce CaCO3 precipitation in vitro, from samples taken from speleothems in the galleries of Stiffe’s cave, L’Aquila, Italy. We found a large number of bacteria in the calcite formations (1 x 104 to 5 x 109 cells g-1. Microscopic examination, in laboratory conditions at different temperatures, showed that most of the isolates were able to form calcium carbonate microcrystals. The most crystalline precipitates were observed at 32°C. No precipitation was detected in un-inoculated controls media or in media that had been inoculated with autoclaved bacterial cells. X-ray diffraction (XRD analysis showed that most of the carbonate crystals produced were calcite. Bacillus strains were the most common calcifying isolates collected from Stiffe’s Cave. Analysis of carbonate-solubilization capability revealed that the non-calcifying bacteria were carbonate solubilizers.

  18. Numerical simulation of lava flow using a GPU SPH model

    OpenAIRE

    Eugenio Rustico; Annamaria Vicari; Giuseppe Bilotta; Alexis Hérault; Ciro Del Negro

    2011-01-01

    A smoothed particle hydrodynamics (SPH) method for lava-flow modeling was implemented on a graphical processing unit (GPU) using the compute unified device architecture (CUDA) developed by NVIDIA. This resulted in speed-ups of up to two orders of magnitude. The three-dimensional model can simulate lava flow on a real topography with free-surface, non- Newtonian fluids, and with phase change. The entire SPH code has three main components, neighbor list construction, force computation, an...

  19. TWO ALKYLATED FLAVONOID ISOLATED FROM THE STEM OF THE FERN Chingia sakayensis (Zeiller Holtt

    Directory of Open Access Journals (Sweden)

    Suyatno Suyatno

    2010-06-01

    Full Text Available Two known alkylated flavonoid namely matteucinol dan matteucinol-7-O-b-D-glucoside was isolated for the first time from the fern Chingia sakayensis (Zeiller Holtt's stem. Their structures were elucidated on the basis of spectroscopic evidence and by comparation with those reported data in literature.   Keywords: Fern, Chingia sakayensis, stem, alkylated flavonoid, matteucinol, matteucinol-7-O-b-D-glucoside

  20. Transcriptome-mining for single-copy nuclear markers in ferns.

    Directory of Open Access Journals (Sweden)

    Carl J Rothfels

    Full Text Available BACKGROUND: Molecular phylogenetic investigations have revolutionized our understanding of the evolutionary history of ferns-the second-most species-rich major group of vascular plants, and the sister clade to seed plants. The general absence of genomic resources available for this important group of plants, however, has resulted in the strong dependence of these studies on plastid data; nuclear or mitochondrial data have been rarely used. In this study, we utilize transcriptome data to design primers for nuclear markers for use in studies of fern evolutionary biology, and demonstrate the utility of these markers across the largest order of ferns, the Polypodiales. PRINCIPAL FINDINGS: We present 20 novel single-copy nuclear regions, across 10 distinct protein-coding genes: ApPEFP_C, cryptochrome 2, cryptochrome 4, DET1, gapCpSh, IBR3, pgiC, SQD1, TPLATE, and transducin. These loci, individually and in combination, show strong resolving power across the Polypodiales phylogeny, and are readily amplified and sequenced from our genomic DNA test set (from 15 diploid Polypodiales species. For each region, we also present transcriptome alignments of the focal locus and related paralogs-curated broadly across ferns-that will allow researchers to develop their own primer sets for fern taxa outside of the Polypodiales. Analyses of sequence data generated from our genomic DNA test set reveal strong effects of partitioning schemes on support levels and, to a much lesser extent, on topology. A model partitioned by codon position is strongly favored, and analyses of the combined data yield a Polypodiales phylogeny that is well-supported and consistent with earlier studies of this group. CONCLUSIONS: The 20 single-copy regions presented here more than triple the single-copy nuclear regions available for use in ferns. They provide a much-needed opportunity to assess plastid-derived hypotheses of relationships within the ferns, and increase our capacity to

  1. The microsoroid ferns: Inferring the relationships of a highly diverse lineage of Paleotropical epiphytic ferns (Polypodiaceae, Polypodiopsida).

    Science.gov (United States)

    Kreier, Hans-Peter; Zhang, Xian-Chun; Muth, Heiko; Schneider, Harald

    2008-09-01

    The relationships of the microsoroid ferns were studied using a DNA sequence-based phylogenetic approach. Nucleotide sequences for up to four chloroplast genome regions were assembled for 107 samples from 87 species. Microsoroids s.l. include six lineages of which two are species rich. The results indicate that several genera are not monophyletic (e.g. Microsorum), several controversial genera are confirmed to be monophyletic (e.g. Leptochilus), and some genera new to science should be recognized (M. membranaceum clade). Unique insights were gained into the biogeographic history of this highly diverse epiphytic vascular plant lineage that is widespread in continental Asia to Australasia. Evidence was found for splits into lineages diversifying in parallel in continental Asia and Malesia. No evidence was recovered for an African radiation because all African microsoroid species either also are found in Asia or have sister species in continental Asia. In contrast, evidence for independent radiations were discovered for the Australasian region.

  2. Stochastic modeling of a lava-flow aquifer system

    Science.gov (United States)

    Cronkite-Ratcliff, Collin; Phelps, Geoffrey A.

    2014-01-01

    This report describes preliminary three-dimensional geostatistical modeling of a lava-flow aquifer system using a multiple-point geostatistical model. The purpose of this study is to provide a proof-of-concept for this modeling approach. An example of the method is demonstrated using a subset of borehole geologic data and aquifer test data from a portion of the Calico Hills Formation, a lava-flow aquifer system that partially underlies Pahute Mesa, Nevada. Groundwater movement in this aquifer system is assumed to be controlled by the spatial distribution of two geologic units—rhyolite lava flows and zeolitized tuffs. The configuration of subsurface lava flows and tuffs is largely unknown because of limited data. The spatial configuration of the lava flows and tuffs is modeled by using a multiple-point geostatistical simulation algorithm that generates a large number of alternative realizations, each honoring the available geologic data and drawn from a geologic conceptual model of the lava-flow aquifer system as represented by a training image. In order to demonstrate how results from the geostatistical model could be analyzed in terms of available hydrologic data, a numerical simulation of part of an aquifer test was applied to the realizations of the geostatistical model.

  3. Studies of vesicle distribution patterns in Hawaiian lavas

    Science.gov (United States)

    Walker, George P. L.

    1987-01-01

    Basaltic lava flows are generally vesicular, and the broader facts relating to vesicle distribution have long been established; few studies have yet been made with a view to determining how and when vesicles form in the cooling history of the lava, explaining vesicle shape and size distribution, and gaining enough understanding to employ vesicles as a geological tool. Various avenues of approach exist by which one may seek to gain a better understanding of these ubiquitous structures and make a start towards developing a general theory, and three such avenues have recently been explored. One avenue involves the study of pipe vesicles; these are a well known feature of lava flows and are narrow pipes which occur near the base of many pahoehoe flow units. Another avenue of approach is that presented by the distinctive spongy pahoehoe facies of lava that is common in distal locations on Hawaiian volcanoes. A third avenue of approach is that of the study of gas blisters in lava. Gas blisters are voids, which can be as much as tens of meters wide, where the lava split along a vesicle-rich layer and the roof up-arched by gas pressure. These three avenues are briefly discussed.

  4. Cave crawling in zebra finch skulls

    DEFF Research Database (Denmark)

    Larsen, Ole Næsbye; Salomon, Rasmus; Jensen, Kenneth Kragh

    are acoustically coupled through an air-filled interaural canal (IAC) often illustrated and modelled as a simple tube, which allows sound to propagate through the skull from one ear to the other and considerably enhance the cues for directional hearing. Theoretically, different combinations of frequency dependent......Cave crawling in zebra finch skulls: what is the functional interaural canal? Ole Næsbye Larsen, Rasmus Salomon, Kenneth Kragh Jensen, and Jakob Christensen-Dalsgaard Department of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark The middle ears of birds...... is IAC trabeculated and irregularly shaped but it also communicates with a set of highly complex, air-filled canals in the skull extending to the base of the beak. We tested the possible influence of these communicating cavities by measuring eardrum directionality and interaural transmission before...

  5. Stable transformation of ferns using spores as targets: Pteris vittata and Ceratopteris thalictroides.

    Science.gov (United States)

    Muthukumar, Balasubramaniam; Joyce, Blake L; Elless, Mark P; Stewart, C Neal

    2013-10-01

    Ferns (Pteridophyta) are very important members of the plant kingdom that lag behind other taxa with regards to our understanding of their genetics, genomics, and molecular biology. We report here, to our knowledge, the first instance of stable transformation of fern with recovery of transgenic sporophytes. Spores of the arsenic hyperaccumulating fern Pteris vittata and tetraploid 'C-fern Express' (Ceratopteris thalictroides) were stably transformed by Agrobacterium tumefaciens with constructs containing the P. vittata actin promoter driving a GUSPlus reporter gene. Reporter gene expression assays were performed on multiple tissues and growth stages of gametophytes and sporophytes. Southern-blot analysis confirmed stable transgene integration in recovered sporophytes and also confirmed that no plasmid from A. tumefaciens was present in the sporophyte tissues. We recovered seven independent transformants of P. vittata and four independent C. thalictroides transgenics. Inheritance analyses using β-glucuronidase (GUS) histochemical staining revealed that the GUS transgene was stably expressed in second generation C. thalictroides sporophytic tissues. In an independent experiment, the gusA gene that was driven by the 2× Cauliflower mosaic virus 35S promoter was bombarded into P. vittata spores using biolistics, in which putatively stable transgenic gametophytes were recovered. Transformation procedures required no tissue culture or selectable marker genes. However, we did attempt to use hygromycin selection, which was ineffective for recovering transgenic ferns. This simple stable transformation method should help facilitate functional genomics studies in ferns.

  6. On the widespread capacity for, and functional significance of, extreme inbreeding in ferns.

    Science.gov (United States)

    Sessa, Emily B; Testo, Weston L; Watkins, James E

    2016-08-01

    Homosporous vascular plants utilize three different mating systems, one of which, gametophytic selfing, is an extreme form of inbreeding only possible in homosporous groups. This mating system results in complete homozygosity in all progeny and has important evolutionary and ecological implications. Ferns are the largest group of homosporous land plants, and the significance of extreme inbreeding for fern evolution has been a subject of debate for decades. We cultured gametophytes in the laboratory and quantified the relative frequencies of sporophyte production from isolated and paired gametophytes, and examined associations between breeding systems and several ecological and evolutionary traits. The majority of fern species studied show a capacity for gametophytic selfing, producing sporophytes from both isolated and paired gametophytes. While we did not follow sporophytes to maturity to investigate potential detrimental effects of homozygosity at later developmental stages, our results suggest that gametophytic selfing may have greater significance for fern evolution and diversification than has previously been realized. We present evidence from the largest study of mating behavior in ferns to date that the capacity for extreme inbreeding is prevalent in this lineage, and we discuss its implications and relevance and make recommendations for future studies of fern mating systems.

  7. Mycorrhizae increase arsenic uptake by the hyperaccumulator Chinese brake fern (Pteris vittata L.).

    Science.gov (United States)

    Al Agely, Abid; Sylvia, David M; Ma, Lena Q

    2005-01-01

    Chinese brake fern (Pteris vittata L.) is a hyperaccumulator of arsenic (As) that grows naturally on soils in the southern United States. It is reasonable to expect that mycorrhizal symbiosis may be involved in As uptake by this fern. This is because arbuscular mycorrhizal (AM) fungi have a well-documented role in increasing plant phosphorus (P) uptake, P and As have similar chemical properties, and ferns are known to be colonized by AM fungi. We conducted a factorial greenhouse experiment with three levels of As (0, 50, and 100 mg kg(-1)) and P (0, 25, and 50 mg kg(-1)) and with and without Chinese brake fern colonized by a community of AM fungi from an As-contaminated site. We found that the AM fungi not only tolerated As amendment, but their presence increased frond dry mass at the highest As application rate. Furthermore, the AM fungi increased As uptake across a range of P levels, while P uptake was generally increased only when there was no As amendment. These data indicate that AM fungi have an important role in arsenic accumulation by Chinese brake fern. Therefore, to effectively phytoremediate As-contaminated soils, the mycorrhizal status of ferns needs to be taken into account.

  8. Lava-substrate heat transfer: Laboratory experiments and thermodynamic modeling

    Science.gov (United States)

    Rumpf, M.; Fagents, S. A.; Hamilton, C. W.; Wright, R.; Crawford, I.

    2012-12-01

    We have performed laboratory experiments and numerical modeling to investigate the heat transfer from a lava flow into various substrate materials, focusing on the effects of the differing thermophysical properties of substrate materials. Initial motivation for this project developed from the desire to understand the loss of solar wind volatiles embedded in lunar regolith deposits that were subsequently covered by a lava flow. The Moon lacks a significant atmosphere and magnetosphere, leaving the surface regolith exposed to bombardment by solar flare and solar wind particles, and by the cosmogenic products of galactic cosmic rays. Preservation of particle-rich regolith deposits may have occurred by the emplacement of an active lava flow on top of the regolith layer, provided the embedded particles survive heating by the lava. During future expeditions to the lunar surface, ancient regolith deposits could be sampled through surface drilling to extract the extra-lunar particles, revealing a history of the solar activity and galactic events not available on the Earth. This project also has important implications for terrestrial lava flows, particularly in the prediction of lava flow hazards. Lava erupted on Earth may be emplaced on various substrates, including solid lava rock, volcanic tephra, sands, soils, etc. The composition, grain size, consolidation, moisture content, etc. of these materials will vary greatly and have different effects on the cooling of the flow. Accounting for specific properties of the substrate could be an important improvement in lava flow models We have performed laboratory experiments in collaboration with the Department of Art and Art History at the University of Hawaii at Manoa in which ~5-6 kg of basalt, collected at Kilauea Volcano, Hawaii, is melted to ~1200 °C. The lava is poured into a device constructed of calcium silicate sheeting that has been filled with a solid or particulate substrate material and embedded with thermocouples

  9. Logan Cave National Wildlife Refuge: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Logan Cave NWR for the next 15 years. This plan outlines the Refuge vision and purpose...

  10. Logan Cave National Wildlife Refuge [Land Status Map

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This map was produced by the Division of Realty to depict landownership at Logan Cave National Wildlife Refuge. It was generated from rectified aerial photography,...

  11. Luminescence dating at Rose cottage cave: a progress report

    CSIR Research Space (South Africa)

    Woodborne, S

    1997-10-01

    Full Text Available Deal with infrared-stimulated luminescence and thermoluminescence dates from Rose Cottage Cave in South Africa. Discrepancy between luminescence and radiocarbon dates; Concentration of radioactive elements in sediments before and after leaching...

  12. Groundwater Quality Monitoring at Logan Cave National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of the current project was to continue establishing a long term groundwater quality monitoring program at Logan Cave that would allow groundwater threats...

  13. Center for Advanced Energy Studies: Computer Assisted Virtual Environment (CAVE)

    Data.gov (United States)

    Federal Laboratory Consortium — The laboratory contains a four-walled 3D computer assisted virtual environment - or CAVE TM — that allows scientists and engineers to literally walk into their data...

  14. Optically stimulated luminescence dating at Rose Cottage Cave

    CSIR Research Space (South Africa)

    Pienaar, M

    2008-01-01

    Full Text Available Six Optically stimulated luminescence (OSL) dates are compared with stratigraphically associated C-14 dates from Rose Cottage Cave. The OSL dates overlap the accepted C-14 chronology except for one sample that overestimates the expected age...

  15. Contaminant concentrations in water and sediments from Shelta Cave

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Shelta Cave is a cavern system which lies under the northwestern portion of the City of Huntsville, Alabama. The National Speleological Society owns property which...

  16. Velcro Tubes 2004 Timpanogos Cave National Monument, Utah

    Data.gov (United States)

    National Park Service, Department of the Interior — Velcro Tubes section of the detailed map of Timpanogos Cave created by Brandon Kowallis 2004 using Adobe Illustrator 10. The map was created from Rod Horrock's...

  17. Ancient photosynthetic eukaryote biofilms in an Atacama Desert coastal cave

    Science.gov (United States)

    Azua-Bustos, A.; Gonzalez-Silva, C.; Mancilla, R.A.; Salas, L.; Palma, R.E.; Wynne, J.J.; McKay, C.P.; Vicuna, R.

    2009-01-01

    Caves offer a stable and protected environment from harsh and changing outside prevailing conditions. Hence, they represent an interesting habitat for studying life in extreme environments. Here, we report the presence of a member of the ancient eukaryote red algae Cyanidium group in a coastal cave of the hyperarid Atacama Desert. This microorganism was found to form a seemingly monospecific biofilm growing under extremely low photon flux levels. Our work suggests that this species, Cyanidium sp. Atacama, is a new member of a recently proposed novel monophyletic lineage of mesophilic "cave" Cyanidium sp., distinct from the remaining three other lineages which are all thermo-acidophilic. The cave described in this work may represent an evolutionary island for life in the midst of the Atacama Desert. ?? Springer Science + Business Media, LLC 2009.

  18. Unexplored diversity and conservation potential of neotropical hot caves.

    Science.gov (United States)

    Ladle, Richard J; Firmino, João V L; Malhado, Ana C M; Rodríguez-Durán, Armando

    2012-12-01

    The term hot cave is used to describe some subterranean chambers in the Neotropics that are characterized by constantly high ambient temperatures generated by the body heat of high densities of certain bat species. Many of these species have limited geographic ranges, and some occur only in the hot-cave environment. In addition to the bats, the stable microclimate and abundant bat guano provides refuge and food for a high diversity of invertebrates. Hot caves have so far been described in the Caribbean and in a few isolated locations from Mexico to Brazil, although there is some evidence that similar caves may be present throughout the tropics. The existing literature suggests these poorly known ecosystems, with their unique combination of geomorphology and bat-generated microclimate, are particularly sensitive to disturbance and face multiple threats from urbanization, agricultural development, mining, and tourism.

  19. The biogeochemistry of anchialine caves: Progress and possibilities

    Science.gov (United States)

    Pohlman, John W.

    2011-01-01

    Recent investigations of anchialine caves and sinkholes have identified complex food webs dependent on detrital and, in some cases, chemosynthetically produced organic matter. Chemosynthetic microbes in anchialine systems obtain energy from reduced compounds produced during organic matter degradation (e.g., sulfide, ammonium, and methane), similar to what occurs in deep ocean cold seeps and mud volcanoes, but distinct from dominant processes operating at hydrothermal vents and sulfurous mineral caves where the primary energy source is mantle derived. This review includes case studies from both anchialine and non-anchialine habitats, where evidence for in situ chemosynthetic production of organic matter and its subsequent transfer to higher trophic level metazoans is documented. The energy sources and pathways identified are synthesized to develop conceptual models for elemental cycles and energy cascades that occur within oligotrophic and eutrophic anchialine caves. Strategies and techniques for testing the hypothesis of chemosynthesis as an active process in anchialine caves are also suggested.

  20. Contamination of basaltic lava by seawater: Evidence found in a lava pillar from Axial Seamount, Juan de Fuca Ridge

    Science.gov (United States)

    Schiffman, Peter; Zierenberg, Robert; Chadwick, William W.; Clague, David A.; Lowenstern, Jacob

    2010-04-01

    A lava pillar formed during the 1998 eruption at Axial Seamount exhibits compositional and textural evidence for contamination by seawater under magmatic conditions. Glass immediately adjacent to anastomosing microfractures within 1 cm of the inner pillar wall is oxidized and significantly enriched in Na and Cl and depleted in Fe and K with respect to that in glassy selvages from the unaffected outer pillar wall. The affected glass contains up to 1 wt % Cl and is enriched by ˜2 wt % Na2O relative to unaffected glass, consistent with a nearly 1:1 (molar) incorporation of NaCl. Glass bordering the Cl-enriched glass in the inner pillar wall is depleted in Na but enriched in K. The presence of tiny (<10 μm) grains of Cu-Fe sulfides and Fe sulfides as well as elemental Ni, Ag, and Au in the Na-depleted, K-enriched glass of the inner pillar wall implies significant reduction of this glass, presumably by hydrogen generated during seawater contamination and oxidation of lava adjacent to microfractures. We interpret the compositional anomalies we see in the glass of the interior pillar wall as caused by rapid incorporation of seawater into the still-molten lava during pillar growth, probably on the time scale of seconds to minutes. Only one of seven examined lava pillars shows this effect, and we interpret that seawater has to be trapped in contact with molten lava (inside the lava pillar, in this case) to produce the effects we see. Thus, under the right conditions, seawater contamination of lavas during submarine eruptions is one means by which the oceanic crust can sequester Cl during its global flux cycle. However, since very few recent lava flows have been examined in similar detail, the global significance of this process in effecting Earth's Cl budget remains uncertain.

  1. Some new cave diving exploration results from Croatian karst area

    Science.gov (United States)

    Garasic, Davor; Garasic, Mladen

    2017-04-01

    In the recent years, several international cave diving expeditions took place in the Dinaric karst of Croatia. The objectives were conducting a new research of previously known karstic springs and also exploring new ones. The deepest karst cave in Croatia filled with water is Crveno jezero (lake) near Imotski town, with water depth of 281 meters and total cave depth of 528 meters. Volume of water in this cave is about 16 millions m3. Diving expeditions were held in 1997 and 1998.The deepest karst spring in the Dinaric karst of Croatia is Vrelo of Una River (with max discharge about 100 m3/s), where divers measured depth of -248 meters. Explorations were made in 2007 and 2016. Sinac spring in Pla\\vsko Polje has been dived to the depth of -203 meters. Cave diving was done in 1984, 1999, 2003, 2007 - 2016. Furthermore, very popular springs of the river Kupa (-155 m) in Gorski Kotar (explored since1995 till 2015), river Gacka (-105 in depth, 1150m in length) in Lika, explored from 1992 to 2016, river Cetina (-110 m in depth, 1300 m in length), cave diving explored from 2000 to 2016 in the Dalmatinska Zagora, Rumin Veliki spring (- 150 m in depth) in the Sinjska Krajina (explored and dived in 2006 and 2010), than rivers Krnjeza and Krupa in Ravni kotari with diving depths of over 100 meters (in 2004 and 2005) and so on. Along the Adriatic coast in Croatia there are many deep and long submarine springs (vrulje), ie. caves under seawater springs. called - vruljas for example Vrulja Zecica with over 900 meters ine length and Vrulja Modrič with completely flooded cave channels that extend over 2300 meters in length. Cave diving was conducted from 2010 to 2016. Vrulja Dubci is also worth mentioning (dived and explored in 2000), 161 meters deep and so on. Tectonic activity plays a dominant role in the creation and function of these caves. Geological, hydrogeological and lithostratigraphic conditions are also very important in speleogenesis of these caves in Croatian karst

  2. Some Caves in tunnels in Dinaric karst of Croatia

    Science.gov (United States)

    Garasic, Mladen; Garasic, Davor

    2016-04-01

    In the last 50 years during the construction of almost all the tunnels in the Croatian Dinaric Karst thousands of caves have been encountered that represented the major problems during the construction works. Geological features (fissures, folding, faults, etc.) are described in this contribution, together with the hydrogeological conditions (rapid changes in groundwater levels). Special engineering geological exploration and survey of each cave, together with the stabilization of the tunnel ceiling, and groundwater protection actions according to basic engineering geological parameters are also presented. In karst tunneling in Croatia over 150 caves longer than 500 m have been investigated. Several caves are over 300 m deep (St. Ilija tunnel in Biokovo Mt), and 10 are longer than 1000 m (St.Rok tunnel, HE Senj and HE Velebit tunnels in Velebit Mt, Ucka tunnel in Ucka Mt, Mala kapela tunnel in Kapela Mt, caverns in HE Plat tunnel etc). Different solutions were chosen to cross the caves depending on the size and purpose of the tunnels (road, rail, pedestrian tunnel, or hydrotechnical tunnels). This is presentations of interesting examples of ceiling stabilization in big cave chambers, construction of bridges inside tunnels, deviations of tunnels, filling caves, grouting, etc. A complex type of karstification has been found in the cavern at the contact between the Palaeozoic clastic impervious formations and the Mesozoic complex of dolomitic limestones in the Vrata Tunnel and at the contact with flysch in the Učka Tunnel. However, karstification advancing in all directions at a similar rate is quite rare. The need to have the roadway and/or tunnel above water from a spring is the biggest possible engineering-geological, hydrogeological and civil engineering challenge. Significant examples are those above the Jadro spring (Mravinci tunnel) in flysch materials or above the Zvir spring in Rijeka (Katarina tunnel), and in fractured Mesozoic carbonates. Today in Croatian

  3. Review of Hydraulic Fracturing for Preconditioning in Cave Mining

    Science.gov (United States)

    He, Q.; Suorineni, F. T.; Oh, J.

    2016-12-01

    Hydraulic fracturing has been used in cave mining for preconditioning the orebody following its successful application in the oil and gas industries. In this paper, the state of the art of hydraulic fracturing as a preconditioning method in cave mining is presented. Procedures are provided on how to implement prescribed hydraulic fracturing by which effective preconditioning can be realized in any in situ stress condition. Preconditioning is effective in cave mining when an additional fracture set is introduced into the rock mass. Previous studies on cave mining hydraulic fracturing focused on field applications, hydraulic fracture growth measurement and the interaction between hydraulic fractures and natural fractures. The review in this paper reveals that the orientation of the current cave mining hydraulic fractures is dictated by and is perpendicular to the minimum in situ stress orientation. In some geotechnical conditions, these orientation-uncontrollable hydraulic fractures have limited preconditioning efficiency because they do not necessarily result in reduced fragmentation sizes and a blocky orebody through the introduction of an additional fracture set. This implies that if the minimum in situ stress orientation is vertical and favors the creation of horizontal hydraulic fractures, in a rock mass that is already dominated by horizontal joints, no additional fracture set is added to that rock mass to increase its blockiness to enable it cave. Therefore, two approaches that have the potential to create orientation-controllable hydraulic fractures in cave mining with the potential to introduce additional fracture set as desired are proposed to fill this gap. These approaches take advantage of directional hydraulic fracturing and the stress shadow effect, which can re-orientate the hydraulic fracture propagation trajectory against its theoretical predicted direction. Proppants are suggested to be introduced into the cave mining industry to enhance the

  4. Impact of environmental factors on the spectral characteristics of lava surfaces:field spectrometry of basaltic lava flows on Tenerife, Canary Islands, Spain

    OpenAIRE

    Long Li; Carmen Solana; Frank Canters; Jonathan C.-W. Chan; Matthieu Kervyn

    2015-01-01

    We report on spectral reflectance measurements of basaltic lava flows on Tenerife Island, Spain. Lava flow surfaces of different ages, surface roughness and elevations were systematically measured using a field spectroradiometer operating in the range of 350–2500 nm. Surface roughness, oxidation and lichen coverage were documented at each measured site. Spectral properties vary with age and morphology of lava. Pre-historical lavas with no biological coverage show a prominent increase in spect...

  5. Mineralogy of Iza Cave (Rodnei Mountains, N. Romania

    Directory of Open Access Journals (Sweden)

    Tamas Tudor

    2011-07-01

    Full Text Available The secondary minerals from Iza Cave result from the interactions of karst water and/or cave atmosphere with a variety of sedimentaryand metamorphic rocks. The cave passages expose at various extents Eocene limestones and conglomerates, Oligocene blackshales, Upper Precambrian micaschists, marble and dolomitic marble and associated ore deposits. Twelve secondary mineralsidentified in the cave (carbonates, sulfates, phosphates, oxides and hydroxides, and silicates are presented in this study. Calcite,aragonite, gypsum, brushite and hydroxylapatite are the components of common speleothems in the limestone, dolomite andconglomerate areas of the cave. Ankerite crusts are related to areas with pyrite mineralization within the metamorphic carbonaterocks. Goethite, jarosite, hematite and gypsum form various speleothems in the sectors within micaschists and conglomerates. Largeweathering deposits occurring in passage areas developed within micaschists consist of illite, kaolinite, jarosite, goethite, gypsumand alunite. The extent of the weathering deposits occurring on non-karst rocks in the underground environment makes this cave aparticularly interesting site for studies of water-rock interactions.

  6. The Influence of Topographic Obstacles on Basaltic Lava Flow Morphologies

    Science.gov (United States)

    von Meerscheidt, H. C.; Brand, B. D.; deWet, A. P.; Bleacher, J. E.; Hamilton, C. W.; Samuels, R.

    2014-12-01

    Smooth pāhoehoe and jagged ´áā represent two end-members of a textural spectrum that reflects the emplacement characteristics of basaltic lava flows. However, many additional textures (e.g., rubbly and slabby pāhoehoe) reflect a range of different process due to lava flow dynamics or interaction with topography. Unfortunately the influence of topography on the distribution of textures in basaltic lava flows is not well-understood. The 18 ± 1.0 ka Twin Craters lava flow in the Zuni-Bandera field (New Mexico, USA) provides an excellent site to study the morphological changes of a lava flow that encountered topographic obstacles. The flow field is 0.2-3.8 km wide with a prominent central tube system that intersects and wraps around a 1000 m long ridge, oriented perpendicular to flow. Upstream of the ridge, the flow has low-relief inflation features extending out and around the ridge. This area includes mildly to heavily disrupted pāhoehoe with interdispersed agglutinated masses, irregularly shaped rubble and lava balls. Breakouts of ´áā and collapse features are also common. These observations suggest crustal disruption due to flow-thickening upstream from the ridge and the movement of lava out and around the obstacle. While the ridge influenced the path of the tube, which wraps around the southern end of the ridge, the series of collapse features and breakouts of ´áā along the tube system are more likely a result of changes in flux throughout the tube system because these features are found both upstream and downstream of the obstacle. This work demonstrates that topography can significantly influence the formation history and surface disruption of a flow field, and in some cases the influence of topography can be separated from the influences of changes in flux along a tube system.

  7. New distribution record for the Indiana cave crayfish, Orconectes inermis inermis cope, from the Patoka River drainage

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Two specimens of the Indiana cave crayfish, Orconectes (Orconectes) inermis inermis Cope, were collected from a cave referred to as Audrey’s Cave on May 21, 2001...

  8. Morphometry and distribution of isolated caves as a guide for phreatic and confined paleohydrological conditions

    Science.gov (United States)

    Frumkin, Amos; Fischhendler, Itay

    2005-04-01

    Isolated caves are a special cave type common in most karst terrains, formed by prolonged slow water flow where aggressivity is locally boosted. The morphometry and distribution of isolated caves are used here to reconstruct the paleohydrology of a karstic mountain range. Within a homogenous karstic rock sequence, two main types of isolated caves are distinguished, and each is associated with a special hydrogeologic setting: maze caves form by rising water in the confined zone of the aquifer, under the Mt. Scopus Group (Israel) confinement, while chamber caves are formed in phreatic conditions, apparently by lateral flow mixing with a vadose input from above.

  9. Geologic controls on cave development in Burnsville Cove, Bath and Highland Counties, Virginia

    Science.gov (United States)

    Swezey, Christopher; Haynes, John T.; Lucas, Philip C.; Lambert, Richard A.

    2017-01-01

    Burnsville Cove in Bath and Highland Counties (Virginia, USA) is a karst region in the Valley and Ridge Province of the Appalachian Mountains. The region contains many caves in Silurian to Devonian limestone, and is well suited for examining geologic controls on cave location and cave passage morphology. In Burnsville Cove, many caves are located preferentially near the axes of synclines and anticlines. For example, Butler Cave is an elongate cave where the trunk channel follows the axis of Sinking Creek syncline and most of the side passages follow joints at right angles to the syncline axis. In contrast, the Water Sinks Subway Cave, Owl Cave, and Helictite Cave have abundant maze patterns, and are located near the axis of Chestnut Ridge anticline. The maze patterns may be related to fact that the anticline axis is the site of the greatest amount of flexure, leading to more joints and (or) greater enlargement of joints. Many of the larger caves of Burnsville Cove (e.g., Breathing Cave, Butler Cave–Sinking Creek Cave System, lower parts of the Water Sinks Cave System) are developed in the Silurian Tonoloway Limestone, the stratigraphic unit with the greatest surface exposure in the area. Other caves are developed in the Silurian to Devonian Keyser Limestone of the Helderberg Group (e.g., Owl Cave, upper parts of the Water Sinks Cave System) and in the Devonian Shriver Chert and (or) Licking Creek Limestone of the Helderberg Group (e.g., Helictite Cave). Within the Tonoloway Limestone, the larger caves are developed in the lower member of the Tonoloway Limestone immediately below a bed of silica-cemented sandstone. In contrast, the larger caves in the Keyser Limestone are located preferentially in limestone beds containing stromatoporoid reefs, and some of the larger caves in the Licking Creek Limestone are located in beds of cherty limestone below the Devonian Oriskany Sandstone. Geologic controls on cave passage morphology include joints, bedding planes, and

  10. Study of radiocarbon dynamics of Baradla Cave, Hungary

    Science.gov (United States)

    Molnár, Mihály; Dezsö, Zoltán; Futo, Istvan; Siklósy, Zoltan; Jull, A. J. Timothy; Koltai, Gabriella

    2016-04-01

    Carbon isotope composition of speleothems and their parent drip water reflects the isotope composition of the atmospheric CO2, the soil and the host rock and can sometimes be influenced even by the cave atmosphere. Owing to the fact that 14C in the bedrock has long decayed, the bedrock derived carbon content of the seepage water can be considered as inactive or "dead carbon". The initial dead carbon proportion (dcp) of a stalagmite or tufa layer, caused by the incorporation of the inactive carbon, can be calculated with the help of the C-14 level differences between the contemporary atmosphere and the formed stone carbonate. The revolutionary technological advances of 14C (AMS) have brought the possibility of analysing 14C dynamics of karst systems due to the small amount of demanded material. The Baradla-Domica Cave is the largest cave of Gömör-Torna Karst, a karst area situated in the northeast of Hungary, and located on the Slovakian-Hungarian borderland. The approximately 26 km long cave is a typical example of multi-level speleogenesis. As a case study we have investigated several recent (age < 50 years) and older (age about 10-11 kyrs) stalagmites and recent drip water, some freshwater tufa samples and the recent cave air carbon-dioxide of the Baradla-cave to study the carbon dynamics and dead carbon level there. According four modern stalagmites (formed 1991-2004) the current dcp is very small in Baradla Cave (3-7%). Stalagmites deposited in Holocene (U/Th dated) were also characterized by very small dead carbon contents (1-11% dcp). Outside the cave a dpc about 20-25% was found in a freshwater tufa sample. This relatively low dead carbon content might be either explained by the thinness of the limestone bedrock above (56-80 m) or the relatively fast infiltration conditions, or their combined effect. Cave air is enriched in CO2 (2-5 times higher than in natural air, not homogenous) but the source of this surplus CO2 is not the limestone according its

  11. Brezstropa jama v Podbojevem lazu, Rakov Škocjan = Denuded cave in Podbojev laz, Rakov Škocjan

    Directory of Open Access Journals (Sweden)

    Maja Abramović

    2009-01-01

    Full Text Available This paper presents a denuded cave situated in the area of Podbojev laz, on the northwesternside of the Rakov Škocjan. Morphometric and morphogenetic properties of several sectionsof the denuded cave and its surroundings are described in detail. The denuded cave developedfrom an epiphreatic cave system which used to function as an outflow cave system from theRak valley. Morphometrical analysis of the slopes show that the denuded cave was developedin stages. As

  12. Terrestrial Invertebrate Arsenic Accumulation Associated With an Arsenic Hyperaccumulating Fern, Pteris vittata (Polypodiales: Pteridaceae).

    Science.gov (United States)

    Jaffe, B D; Ketterer, M E; Hofstetter, R W

    2016-10-01

    Arsenic (As) can play an important role in the contamination of soils, waters, and air. The toxicity of As to most organisms is well established, but little is known about the interactions between environmental As and terrestrial invertebrates and the fate of As through trophic levels. Pteris vittata L. (Polypodiales: Pteridaceae), a fern that hyperaccumulates arsenic, serves as a potential mechanism to facilitate interactions between environmental arsenic and other biota. We compared invertebrate arsenic concentrations (hereafter as [As]) and bioaccumulation factors associated with soil and fern [As] to elucidate relationships between invertebrate and environmental As exposure. We collected invertebrates in pitfall traps from field sites associated with P. vittata, and identified them to order for whole body arsenic analysis and subsequently family for classification into functional feeding groups. We found that overall [As] in invertebrates increased with soil [As], but not with fern [As]. The absence of a relationship between fern [As] and invertebrate [As] may indicate invertebrates are avoiding the fern. Individual taxonomic groups significantly differed in whole body [As], and individual taxa also varied in their relationship between whole body [As] relative to soil and fern [As]. Overall invertebrate abundance decreased as invertebrate [As] load increased but varied across taxa. One particular herbivore, Callopistria floridensis (Florida fern caterpillar), associated with relatively low environmental As exposure contained over 4,000 mg kg(-1) As. Our results show that As bioaccumulates into higher trophic levels and invertebrate body [As] covary with exposure to naturally occurring environmental [As] associated with P. vittata. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Phylogenetic Relationships of the Fern Cyrtomium falcatum (Dryopteridaceae) from Dokdo Island Based on Chloroplast Genome Sequencing.

    Science.gov (United States)

    Raman, Gurusamy; Choi, Kyoung Su; Park, SeonJoo

    2016-12-02

    Cyrtomium falcatum is a popular ornamental fern cultivated worldwide. Native to the Korean Peninsula, Japan, and Dokdo Island in the Sea of Japan, it is the only fern present on Dokdo Island. We isolated and characterized the chloroplast (cp) genome of C. falcatum, and compared it with those of closely related species. The genes trnV-GAC and trnV-GAU were found to be present within the cp genome of C. falcatum, whereas trnP-GGG and rpl21 were lacking. Moreover, cp genomes of Cyrtomium devexiscapulae and Adiantum capillus-veneris lack trnP-GGG and rpl21, suggesting these are not conserved among angiosperm cp genomes. The deletion of trnR-UCG, trnR-CCG, and trnSeC in the cp genomes of C. falcatum and other eupolypod ferns indicates these genes are restricted to tree ferns, non-core leptosporangiates, and basal ferns. The C. falcatum cp genome also encoded ndhF and rps7, with GUG start codons that were only conserved in polypod ferns, and it shares two significant inversions with other ferns, including a minor inversion of the trnD-GUC region and an approximate 3 kb inversion of the trnG-trnT region. Phylogenetic analyses showed that Equisetum was found to be a sister clade to Psilotales-Ophioglossales with a 100% bootstrap (BS) value. The sister relationship between Pteridaceae and eupolypods was also strongly supported by a 100% BS, but Bayesian molecular clock analyses suggested that C. falcatum diversified in the mid-Paleogene period (45.15 ± 4.93 million years ago) and might have moved from Eurasia to Dokdo Island.

  14. The Influence of Slope Breaks on Lava Flow Surface Disruption

    Science.gov (United States)

    Glaze, Lori S.; Baloga, Stephen M.; Fagents, Sarah A.; Wright, Robert

    2014-01-01

    Changes in the underlying slope of a lava flow impart a significant fraction of rotational energy beyond the slope break. The eddies, circulation and vortices caused by this rotational energy can disrupt the flow surface, having a significant impact on heat loss and thus the distance the flow can travel. A basic mechanics model is used to compute the rotational energy caused by a slope change. The gain in rotational energy is deposited into an eddy of radius R whose energy is dissipated as it travels downstream. A model of eddy friction with the ambient lava is used to compute the time-rate of energy dissipation. The key parameter of the dissipation rate is shown to be rho R(sup 2/)mu, where ? is the lava density and mu is the viscosity, which can vary by orders of magnitude for different flows. The potential spatial disruption of the lava flow surface is investigated by introducing steady-state models for the main flow beyond the steepening slope break. One model applies to slow-moving flows with both gravity and pressure as the driving forces. The other model applies to fast-moving, low-viscosity, turbulent flows. These models provide the flow velocity that establishes the downstream transport distance of disrupting eddies before they dissipate. The potential influence of slope breaks is discussed in connection with field studies of lava flows from the 1801 Hualalai and 1823 Keaiwa Kilauea, Hawaii, and 2004 Etna eruptions.

  15. Cure from the cave: volcanic cave actinomycetes and their potential in drug discovery

    Directory of Open Access Journals (Sweden)

    Cheeptham N.

    2013-01-01

    Full Text Available Volcanic caves have been little studied for their potential as sources of novel microbial species and bioactive compounds with new scaffolds. We present the f irst study of volcanic cave microbiology from Canada and suggest that this habitat has great potential for the isolation of novel bioactive substances. Sample locat ions were plot ted on a contour map that was compiled in ArcView 3.2. Over 400 bacterial isolates were obtained from the Helmcken Falls cave in Wells Gray Provincial Park, British Columbia. From our preliminary screen, of 400 isolates tested, 1% showed activity against extended spectrum ß-lactamase E. coli, 1.75% against Escherichia coli, 2.25% against Acinetobacter baumannii, and 26.50% against Klebsiella pneumoniae. In addition, 10.25% showed activity against Micrococcus luteus, 2% against methicillin resistant Staphylococcus aureus, 9.25% against Mycobacterium smegmatis, 6.25% Pseudomonas aeruginosa and 7.5% against Candida albicans. Chemical and physical characteristics of three rock wall samples were studied using scanning electron microscopy and f lame atomic absorption spectrometry. Calcium (Ca, iron (Fe, and aluminum (Al were the most abundant components while magnesium (Mg, sodium (Na, arsenic (As, lead (Pb, chromium (Cr, and barium (Ba were second most abundant with cadmium (Cd and potassium (K were the least abundant in our samples. Scanning electron microscopy (SEM showed the presence of microscopic life forms in all three rock wall samples. 16S rRNA gene sequencing of 82 isolates revealed that 65 (79.3% of the strains belong to the Streptomyces genus and 5 (6.1% were members of Bacillus, Pseudomonas, Nocardia and Erwinia genera. Interestingly, twelve (14.6% of the 16S rRNA sequences showed similarity to unidentif ied ribosomal RNA sequences in the library databases, the sequences of these isolates need to be further investigated using the EzTaxon-e database (http://eztaxon-e. ezbiocloud.net/ to determine whether

  16. Morphology and evolution of sulphuric acid caves in South Italy

    Science.gov (United States)

    D'Angeli, Ilenia M.; De Waele, Jo; Galdenzi, Sandro; Madonia, Giuliana; Parise, Mario; Vattano, Marco

    2016-04-01

    Sulphuric acid speleogenesis (SAS) related to the upwelling of acid water enriched in H2S and CO2 represents an unusual way of cave development. Since meteoric infiltration waters are not necessarily involved in speleogenesis, caves can form without the typical associated karst expressions (i.e. dolines) at the surface. The main mechanism of sulphuric acid dissolution is the oxidation of H2S (Jones et al., 2015) which can be amplified by bacterial mediation (Engel et al., 2004). In these conditions, carbonate dissolution associated with gypsum replacement, is generally believed to be faster than the normal epigenic one (De Waele et al., 2016). In Italy several SAS caves have been identified, but only few systems have been studied in detail: Frasassi and Acquasanta Terme (Marche)(Galdenzi et al., 2010), Monte Cucco (Umbria) (Galdenzi & Menichetti, 1995), and Montecchio (Tuscany) (Piccini et al., 2015). Other preliminary studies have been carried out in Calabria (Galdenzi, 2007) and Sicily (De Waele et al., 2016). Several less studied SAS cave systems located in South Italy, and in particular in Apulia (Santa Cesarea Terme), Sicily (Acqua Fitusa, Acqua Mintina) and Calabria (Mt. Sellaro and Cassano allo Ionio) have been selected in the framework of a PhD thesis on SAS caves and their speleogenesis. Using both limestone tablet weight loss (Galdenzi et al., 2012) and micro erosion meter (MEM) (Furlani et al., 2010) methods the dissolution rate above and under water in the caves will be quantified. Geomorphological observations, landscape analysis using GIS tools, and the analysis of gypsum and other secondary minerals (alunite and jarosite) (stable isotopes and dating) will help to reconstruct the speleogenetic stages of cave formation. Preliminary microbiological analysis will determine the microbial diversity and ecology in the biofilms. References Engel S.A., Stern L.A., Bennett P.C., 2004 - Microbial contributions to cave formation: New insight into sulfuric acid

  17. Carbon dioxide seasonality in dynamically ventilated caves: the role of advective fluxes

    Science.gov (United States)

    Lang, Marek; Faimon, Jiří; Godissart, Jean; Ek, Camille

    2017-08-01

    The seasonality in cave CO2 levels was studied based on (1) a new data set from the dynamically ventilated Comblain-au-Pont Cave (Dinant Karst Basin, Belgium), (2) archive data from Moravian Karst caves, and (3) published data from caves worldwide. A simplified dynamic model was proposed for testing the effect of all conceivable CO2 fluxes on cave CO2 levels. Considering generally accepted fluxes, i.e., the direct diffusive flux from soils/epikarst, the indirect flux derived from dripwater degassing, and the input/output fluxes linked to cave ventilation, gives the cave CO2 level maxima of 1.9 × 10-2 mol m-3 (i.e., ˜ 440 ppmv), which only slightly exceed external values. This indicates that an additional input CO2 flux is necessary for reaching usual cave CO2 level maxima. The modeling indicates that the additional flux could be a convective advective CO2 flux from soil/epikarst driven by airflow (cave ventilation) and enhanced soil/epikarstic CO2 concentrations. Such flux reaching up to 170 mol s-1 is capable of providing the cave CO2 level maxima up to 3 × 10-2 mol m-3 (70,000 ppmv). This value corresponds to the maxima known from caves worldwide. Based on cave geometry, three types of dynamic caves were distinguished: (1) the caves with the advective CO2 flux from soil/epikarst at downward airflow ventilation mode, (2) the caves with the advective soil/epikarstic flux at upward airflow ventilation mode, and (3) the caves without any soil/epikarstic advective flux. In addition to CO2 seasonality, the model explains both the short-term and seasonal variations in δ13C in cave air CO2.

  18. Numerical simulation of formation and preservation of Ningwu ice cave, Shanxi, China

    Science.gov (United States)

    Yang, S.; Shi, Y.

    2015-10-01

    Ice caves exist in locations where annual average air temperature is higher than 0 °C. An example is Ningwu ice cave, Shanxi Province, the largest ice cave in China. In order to quantitatively investigate the mechanism of formation and preservation of the ice cave, we use the finite-element method to simulate the heat transfer process at this ice cave. There are two major control factors. First, there is the seasonal asymmetric heat transfer. Heat is transferred into the ice cave from outside very inefficiently by conduction in spring, summer and fall. In winter, thermal convection occurs that transfers heat very efficiently out of the ice cave, thus cooling it down. Secondly, ice-water phase change provides a heat barrier for heat transfer into the cave in summer. The calculation also helps to evaluate effects of global warming, tourists, colored lights, climatic conditions, etc. for sustainable development of the ice cave as a tourism resource. In some other ice caves in China, managers have installed airtight doors at these ice caves' entrances with the intention of "protecting" these caves, but this in fact prevents cooling in winter and these cave ices will entirely melt within tens of years.

  19. Survival and growth of epiphytic ferns depend on resource sharing

    Directory of Open Access Journals (Sweden)

    Hua-Zheng eLu

    2016-03-01

    Full Text Available Locally available resources can be shared within clonal plant systems through physiological integration, thus enhancing their survival and growth. Most epiphytes exhibit clonal growth habit, but few studies have tested effects of physiological integration (resource sharing on survival and growth of epiphytes and whether such effects vary with species. We conducted two experiments, one on individuals (single ramets and another on groups (several ramets within a plot, with severed and intact rhizome treatments (without and with physiological integration on two dominant epiphytic ferns (Polypodiodes subamoena and Lepisorus scolopendrium in a subtropical montane moist forest in Southwest China. Rhizome severing (preventing integration significantly reduced ramet survival in the individual experiment and number of surviving ramets in the group experiment, and it also decreased biomass of both species in both experiments. However, the magnitude of such integration effects did not vary significantly between the two species. We conclude that resource sharing may be a general strategy for clonal epiphytes to adapt to forest canopies where resources are limited and heterogeneously distributed in space and time.

  20. Herschel und die Zukunft der Fern-Infrarot-Astronomie

    Science.gov (United States)

    Linz, Hendrik

    2015-06-01

    Schon lange ist die beobachtende Astronomie den engen Grenzen des optisch Sichbaren entwachsen und hat fast alle Bereiche des elektromagnetischen Spektrums für sich dienstbar gemacht. Im sogenannten nahen und mittleren Infrarot (Wellenlängen zwischen 1-30 μm) sowie im Millimeter- und Radio-Regime (Wellenlängen zwischen 1 mm und 10 m) ist die Erdatmosphäre relativ gut durchlässig für elektromagnetische Signale oder hat zumindest eine Vielzahl von spektral begrenzten Transmissionsfenstern, die astronomische Beobachtungen zumindest von höheren Bergen aus möglich machen. Allerdings ist das sogenannte Ferne Infrarot (FIR, 30-300 μm Wellenlänge) von der Erde aus fast völlig unzugänglich für astronomische Beobachtungen. Selbst für die besten Beobachtungsplätze der Erde bleibt die atmosphärische Transmission durch die immense Wasserdampf- Absorption auf ein absolutes Minimum beschränkt. Jedoch erlaubt uns das FIR Zugang zu Informationen, die sehr nützlich sind für die astrophysikalische Forschung und komplementär zu anderen Wellenlängen-Bereichen.

  1. On the infinite fern of Galois representations of unitary type

    CERN Document Server

    Chenevier, Gaetan

    2009-01-01

    Let E be a CM number field, F its maximal totally real subfield, c the generator of Gal(E/F), p an odd prime totally split in E, and S a finite set of places of E containing the places above p. Let r : G_{E,S} --> GL_3(F_p^bar) be a modular, absolutely irreducible, Galois representation of type U(3), i.e. such that r^* = r^c, and let X(r) be the rigid analytic generic fiber of its universal G_{E,S}-deformation of type U(3). We show that each irreducible component of the Zariski-closure of the modular points in X(r) has dimension at least 6[F:Q]. We study an analogue of the infinite fern of Gouvea-Mazur in this context and deal with the Hilbert modular case as well. As important steps, we prove that any first order deformation of a generic enough crystalline representation of Gal(Q_p^bar/Q_p) (of any dimension) is a linear combination of trianguline deformations, and that unitary eigenvarieties (of any rank) are etale over the weight space at the non-critical classical points. As another application, we obtain...

  2. Essential Oil Constituents and Antioxidant Activity of Asplenium Ferns.

    Science.gov (United States)

    Hammami, Saoussen; Snène, Ali; El Mokni, Ridha; Faidi, Khaled; Falconieri, Danilo; Dhaouadi, Hatem; Piras, Alessandra; Mighri, Zine; Porcedda, Silvia

    2016-09-01

    Two fern species Asplenium adiantum-nigrum L. and Asplenium trichomanes L. collected from the Kroumiria region (Northwest of Tunisia) were individually submitted to hydrodistillation in a Clevenger type apparatus. Volatile organic compounds were identified by GC-MS and GC-FID. Thus, 35 compounds were identified in A. adiantum-nigrum essential oil accounting for 77.5% of the whole constituents dominated by palmitic acid (34.5%); however, only 29 volatiles were identified in A. trichomanes showing a high amount of phytol, an odorous diterpene alcohol, representing 14.4% of the total oil contents. The total phenolic content and the antioxidant effects of crude extracts from both pteridophytes were determined using Folin-Ciocalteu and 2,2'-diphenyl-1-picrylhydrazyl free radical-scavenging assays, respectively. A. adiantum-nigrum ethyl acetate extract is shown to be lower in total phenolic contents (49.3 mg gallic acid equivalent/g) than similar extract from A. trichomanes (55.4 mg GAE/g).

  3. Survival and Growth of Epiphytic Ferns Depend on Resource Sharing.

    Science.gov (United States)

    Lu, Hua-Zheng; Song, Liang; Liu, Wen-Yao; Xu, Xing-Liang; Hu, Yue-Hua; Shi, Xian-Meng; Li, Su; Ma, Wen-Zhang; Chang, Yan-Fen; Fan, Ze-Xin; Lu, Shu-Gang; Wu, Yi; Yu, Fei-Hai

    2016-01-01

    Locally available resources can be shared within clonal plant systems through physiological integration, thus enhancing their survival and growth. Most epiphytes exhibit clonal growth habit, but few studies have tested effects of physiological integration (resource sharing) on survival and growth of epiphytes and whether such effects vary with species. We conducted two experiments, one on individuals (single ramets) and another on groups (several ramets within a plot), with severed and intact rhizome treatments (without and with physiological integration) on two dominant epiphytic ferns (Polypodiodes subamoena and Lepisorus scolopendrium) in a subtropical montane moist forest in Southwest China. Rhizome severing (preventing integration) significantly reduced ramet survival in the individual experiment and number of surviving ramets in the group experiment, and it also decreased biomass of both species in both experiments. However, the magnitude of such integration effects did not vary significantly between the two species. We conclude that resource sharing may be a general strategy for clonal epiphytes to adapt to forest canopies where resources are limited and heterogeneously distributed in space and time.

  4. Effects of nickel on the fern Regnellidium diphyllum Lindm. (Marsileaceae

    Directory of Open Access Journals (Sweden)

    MA. Kieling-Rubio

    Full Text Available The heterosporous fern Regnellidium diphyllum occurs in southern Brazil and some adjoining localities in Uruguay and Argentina. Currently it is on the list of threatened species in the state of Rio Grande do Sul. Anthropic alterations such as the conversion of wetlands into agricultural areas or water and soil contamination by pollutants may compromise the establishment and survival of this species. Nickel (Ni is an essential nutrient for plants but increasing levels of this metal due to pollution can cause deleterious effects especially in aquatic macrophytes. Megaspore germination tests were performed using Meyer's solution, at concentrations of 0 (control, 0.05, 0.5, 1, 5, 10, 20, 30, 50 and 100 mg L-1 of Ni. The initial development of apomictic sporophytes was studied using solutions containing 0 (control to 4.8 mg L-1 of Ni. A significant negative relation was observed between the different Ni concentrations and the megaspore germination/sporophyte formation rates. Primary roots, primary leaves and secondary leaves were significantly shorter at 3.2 and 4.8 mg L-1 of Ni, when compared with the treatment without this metal. At 4.8 mg L-1, leaves also presented chlorosis and necrosis. The introduction of pollutants with Ni in the natural habitat of Regnellidium diphyllum may inhibit the establishment of plants in the initial stage of development, a problem to be considered in relation to the conservation of this species.

  5. Arsenic in the rhizosphere soil solution of ferns.

    Science.gov (United States)

    Wei, Chaoyang; Zheng, Huan; Yu, Jiangping

    2012-12-01

    The aim of this study was to explore the evidence of arsenic hyperaccumulation in plant rhizosphere solutions. Six common fern plants were selected and grown in three types of substrate: arsenic (As) -tailings, As-spiked soil, and soil-As-tailing composites. A rhizobox was designed with an in-situ collection of soil solutions to analyze changes in the As concentration and valence as well as the pH, dissolved organic carbon (DOC) and total nitrogen (TN). Arsenite composed less than 20% of the total As, and As depletion was consistent with N depletion in the rhizosphere solutions of the various treatments. The As concentrations in the rhizosphere and non-rhizosphere solutions in the presence of plants were lower than in the respective controls without plants, except for in the As-spiked soils. The DOC concentrations were invariably higher in the rhizosphere versus non-rhizosphere solutions from the various plants; however, no significant increase in the DOC content was observed in Pteris vittata, in which only a slight decrease in pH appeared in the rhizosphere compared to non-rhizosphere solutions. The results showed that As reduction by plant roots was limited, acidification-induced solubilization was not the mechanism for As hyperaccumulation.

  6. Flow Classification and Cave Discharge Characteristics in Unsaturated Karst Formation

    Science.gov (United States)

    Mariethoz, G.; Mahmud, K.; Baker, A.; Treble, P. C.

    2015-12-01

    In this study we utilize the spatial array of automated cave drip monitoring in two large chambers of the Golgotha Cave, SW Australia, developed in Quaternary aeolianite (dune limestone), with the aim of understanding infiltration water movement via the relationships between infiltration, stalactite morphology and groundwater recharge. Mahmud et al. (2015) used the Terrestrial LiDAR measurements to analyze stalactite morphology and to characterize possible flow locations in this cave. Here we identify the stalactites feeding the drip loggers and classify each as matrix (soda straw or icicle), fracture or combined-flow. These morphology-based classifications are compared with flow characteristics from the drip logger time series and the discharge from each stalactite is calculated. The total estimated discharge from each area is compared with infiltration estimates to better understand flow from the surface to the cave ceilings of the studied areas. The drip discharge data agrees with the morphology-based flow classification in terms of flow and geometrical characteristics of cave ceiling stalactites. No significant relationships were observed between the drip logger discharge, skewness and coefficient of variation with overburden thickness, due to the possibility of potential vadose-zone storage volume and increasing complexity of the karst architecture. However, these properties can be used to characterize different flow categories. A correlation matrix demonstrates that similar flow categories are positively correlated, implying significant influence of spatial distribution. The infiltration water comes from a larger surface area, suggesting that infiltration is being focused to the studied ceiling areas of each chamber. Most of the ceiling in the cave site is dry, suggesting the possibility of capillary effects with water moving around the cave rather than passing through it. Reference:Mahmud et al. (2015), Terrestrial Lidar Survey and Morphological Analysis to

  7. Speleothems in gypsum caves and their paleoclimatological significance

    Science.gov (United States)

    Calaforra, J. M.; Forti, P.; Fernandez-Cortes, A.

    2008-01-01

    This article highlights the relationship between speleothems growing inside gypsum caves and the particular climate that existed during their development. Speleothems in gypsum caves normally consist of calcium carbonate (calcite) or calcium sulphate (gypsum) and the abundance of such deposits greatly differs from zone to zone. Observations carried out over the last 20 years in gypsum caves subjected to very different climates (Italy, Spain, New Mexico, northern Russia, Cuba, Argentina) highlight wide variation in their cave deposits. In arid or semi-arid climates, the speleothems are mainly composed of gypsum, whilst in temperate, humid or tropical regions, carbonate formations are largely predominant. In polar zones no speleothems develop. These mineralogical details could be useful paleoclimatic indicators of climate change. The interpretation proposed is based on the fact that in gypsum karst the kind of speleothems deposited is determined by competition between the two principal mechanisms that cause precipitation of calcite and gypsum. These mechanisms are completely different: calcite speleothem evolution is mainly controlled by CO2 diffusion, while gypsum deposits develop mostly due to evaporation. Therefore, the prevalence of one kind of speleothem over the other, and the relationship between the solution precipitation processes of calcite and gypsum, may provide evidence of a specific paleoclimate. Additionally, other non-common deposits in gypsum caves like moonmilk, cave rafts and dolomite speleothems can be used as markers for the prevalence of long, dry periods in humid areas, seasonal changes in climate, or rainfall trends in some gypsum areas. Moreover, the dating of gypsum speleothems could contribute paleoclimatic data relating to dry periods when calcite speleothems are not deposited. In contrast, the dating of calcite speleothems in gypsum caves could identify former wet periods in arid zones.

  8. Ancient human footprints in Ciur-Izbuc Cave, Romania.

    Science.gov (United States)

    Webb, David; Robu, Marius; Moldovan, Oana; Constantin, Silviu; Tomus, Bogdan; Neag, Ionel

    2014-09-01

    In 1965, Ciur-Izbuc Cave in the Carpathian Mountains of Romania was discovered to contain about 400 ancient human footprints. At that time, researchers interpreted the footprints to be those of a man, woman and child who entered the cave by an opening which is now blocked but which was usable in antiquity. The age of the prints (≈10-15 ka BP) was based partly on their association with cave bear (Ursus spelaeus) footprints and bones, and the belief that cave bears became extinct near the end of the last ice age. Since their discovery, the human and bear evidence and the cave itself have attracted spelunkers and other tourists, with the result that the ancient footprints are in danger of destruction by modern humans. In an effort to conserve the footprints and information about them and to reanalyze them with modern techiques, Ciur-Izbuc Cave was restudied in summer of 2012. Modern results are based on fewer than 25% of the originally described human footprints, the rest having been destroyed. It is impossible to confirm some of the original conclusions. The footprints do not cluster about three different sizes, and the number of individuals is estimated to be six or seven. Two cases of bears apparently overprinting humans help establish antiquity, and C-14 dates suggest a much greater age than originally thought. Unfortunately, insufficient footprints remain to measure movement variables such as stride length. However, detailed three-dimensional mapping of the footprints does allow a more precise description of human movements within the cave.

  9. Paleo-watertable definition using cave ferromanganese stromatolites and associated cave-wall notches (Sierra de Arnero, Spain)

    Science.gov (United States)

    Rossi, Carlos; Villalaín, Juan J.; Lozano, Rafael P.; Hellstrom, John

    2016-05-01

    The steeply-dipping-dolostone-hosted caves of the Sierra de Arnero (N Spain) contain low-gradient relict canyons with up to ten mapped levels of ferromanganese stromatolites and associated wall notches over a vertical range of 85 m, the highest occurring ~ 460 m above base level. Despite a plausible speleogenetic contribution by pyrite oxidation, and the irregular cave-wall mesomorphologies suggestive of hypogenic speleogenesis, the Arnero relict caves are dominantly epigenic, as indicated by the conduit pattern and the abundant allogenic sediments. Allogenic input declined over time due to a piracy-related decrease in the drainage area of allogenic streams, explaining the large size of the relict Arnero caves relative to the limited present-day outcrop area of the karstified carbonates. Allogenic-sediment input also explains the observed change from watertable canyons to phreatic conduits in the paleo-downstream direction. Stromatolites and notches arguably formed in cave-stream passages at the watertable. The best-defined paleo-watertables show an overall slope of 1.7°, consistent with the present-day relief of the watertable, with higher-slope segments caused by barriers related to sulfide mineralization. The formation of watertable stromatolites favored wall notching by the combined effect of enhanced acidity by Mn-Fe oxidation and shielding of cave floors against erosion. Abrasive bedload further contributed to notch formation by promoting lateral mechanical erosion and protecting passage floors. The irregular wallrock erosional forms of Arnero caves are related partly to paragenesis and partly to the porous nature of the host dolostones, which favored irregular dissolution near passage walls, generating friable halos. Subsequent mechanical erosion contributed to generate spongework patterns. The dolostone porosity also contributes to explain the paradox that virtually all Arnero caves are developed in dolostone despite being less soluble than adjacent

  10. High-resolution Digital Mapping of Historical Lava Flows as a Test-bed for Lava Flow Models

    Science.gov (United States)

    Pyle, D. M.; Parks, M.; Nomikou, P.; Mather, T. A.; Simou, E.; Kalnins, L. M.; Paulatto, M.; Watts, A. B.

    2013-12-01

    Quantitative analysis of high-resolution lava flow morphology can improve our understanding of past effusive eruptions by providing insight into eruptive processes and the rheological properties of erupted magmas. We report the results of an ongoing investigation into the young dacite lava flows of the Kameni islands, Santorini volcano, Greece, which were emplaced during both subaerial and shallow submarine eruptions over the past 3000 years. Historical eruptions of the Kameni islands since 1866 have been very carefully documented in contemporaneous scientific reports. Eruptions since 1573 appear to be time-predictable, with a close relationship between eruption length, the size of extruded lava domes, and the time elapsed since the previous eruption. A new NERC - Airborne Survey and Research Facility LiDAR survey of the Kameni islands was completed in May 2012, using a Leica ALS50 Airborne Laser Scanner mounted on a Dornier 228 aircraft. The topographic surface was mapped at an average point density of 2.1 points per square metre, and covers the entire extent of the youngest subaerial lava flow fields on Santorini. A 2-m DEM derived from the 2012 LiDAR dataset was merged with a 5-m resolution bathymetric grid, based on multibeam surveys carried out by the Hellenic Centre for Marine Research, during cruises in 2001 and 2006, using a SEABEAM 2120 hull-mounted swath system. The resultant grid provides the first high resolution map of both subaerial and submarine historic lava flows emplaced in the centre of the Santorini caldera, and includes several previously unidentified submarine flows and cones. Attribute maps were used to delineate and identify discrete lava flows both onshore and offshore; and morphometric profiles were used to compute accurate volumetric estimates for each of the historic flows, and to determine bulk rheological properties of the lavas, assuming a Bingham rheology. This ongoing work will improve our analysis of the relationship between

  11. Fern-associated arbuscular mycorrhizal fungi are represented by multiple Glomus spp.: do environmental factors influence partner identity?

    Science.gov (United States)

    West, Brittany; Brandt, Jessica; Holstien, Kay; Hill, April; Hill, Malcolm

    2009-06-01

    Symbioses involving arbuscular mycorrhizal fungi (AMF) are among the most important ecological associations for many plant species. The diversity of AMF associated with ferns, however, remains poorly studied. Using recently designed Glomus-specific primers, we surveyed the AMF community associated with ferns from deciduous, broad-leaved second-growth forest habitats at the eastern edge of the piedmont region of central Virginia, USA. Results indicate that this molecular approach may be a useful tool for detecting AMF in ferns compared to traditional techniques based on morphology. Over 30 potential fungal ribotypes were identified from eight fern species using denaturing gradient gel electrophoresis. Fungal ribotypes were found to differ widely in terms of (1) the number of fern partners with which they interact and (2) their relative frequency within each fern. Sequence analysis of fungal isolates from three species of fern indicated that the primers were generally highly specific for Glomus species but some non-target DNA was also amplified. Cloned polymerase chain reaction (PCR) products from Polystichum acrostichoides and Osmunda regalis revealed several phylogenetically distinct Glomus species. A single Glomus species was identified in the cloned PCR products from Botrychium virginianum. These findings challenge the hypothesis that the extent or degree of fern-fungal symbiosis is somehow tied to root complexity. Environmental factors appear to influence the suite of AMF that form partnerships with ferns. Some species of fern from similar habitats associated with dissimilar fungal partners (e.g., P. acrostichoides and Athyrium filix-femina var. asplenioides), whereas others harbored uniform fungal communities (e.g., Asplenium platyneuron). The significance of these data in terms of ecological and evolutionary dynamics of the AMF-fern symbiosis is discussed.

  12. Influence of cooling on lava-flow dynamics

    Science.gov (United States)

    Stasiuk, Mark V.; Jaupart, Claude; Stephen, R.; Sparks, J.

    1993-04-01

    Experiments have been carried out to determine the effects of cooling on the flow of fluids with strongly temperature dependent viscosity. Radial viscous-gravity currents of warm glucose syrup were erupted at constant rate into a flat tank filled with a cold aqueous solution. Cold, viscous fluid accumulates at the leading edge, altering the flow shape and thickness and slowing the spreading. The flows attain constant internal temperature distributions and bulk viscosities. The value of the bulk viscosity depends on the Péclet number, which reflects the advective and diffusive heat transport properties of the flow, the flow skin viscosity, which reflects cooling, and the eruption viscosity. Our results explain why most lava flows have bulk viscosities much higher than the lava eruption viscosity. The results can be applied to understanding dynamic lava features such as flow-front thickening, front avalanches, and welded basal breccias.

  13. Chasing lava: a geologist's adventures at the Hawaiian Volcano Observatory

    Science.gov (United States)

    Duffield, Wendell A.

    2003-01-01

    A lively account of the three years (1969-1972) spent by geologist Wendell Duffield working at the Hawaiian Volcano Observatory at Kilauea, one of the world's more active volcanoes. Abundantly illustrated in b&w and color, with line drawings and maps, as well. Volcanologists and general readers alike will enjoy author Wendell Duffield's report from Kilauea--home of Pele, the goddess of fire and volcanoes. Duffield's narrative encompasses everything from the scientific (his discovery that the movements of cooled lava on a lava lake mimic the movements of the earth's crust, providing an accessible model for understanding plate tectonics) to the humorous (his dog's discovery of a snake on the supposedly snake-free island) to the life-threatening (a colleague's plunge into molten lava). This charming account of living and working at Kilauea, one of the world's most active volcanoes, is sure to be a delight.

  14. Insights into the dynamics of the Nyiragongo lava lake level

    Science.gov (United States)

    Smets, Benoît; d'Oreye, Nicolas; Geirsson, Halldor; Kervyn, Matthieu; Kervyn, François

    2016-04-01

    Nyiragongo volcano, in North Kivu, Democratic Republic of Congo, is among the most active volcanoes in Africa and on Earth. Since the first European observations in the late 19th Century, its eruptive activity mostly concentrated into its main crater, with the presence of a persistent lava lake from at least 1928 to 1977 and since 2002. The size, shape and elevation of this lava lake have evolved through time, modifying the topography of the main crater. In January 1977 and 2002, the uppermost magmatic system of Nyiragongo, including the lava lake, was drained during flank eruptions. These flank events caused major disasters, mostly due to the exceptionally fast-moving lava flows and the presence of a dense population living at foot of this volcano. Despite a large scientific interest and societal concern, the study of the eruptive activity of Nyiragongo remains limited by climate and vegetation conditions that, most of the time, limit use of satellite remote sensing techniques, and recurrent armed conflicts in the Kivu region, which sometimes prevent field access to the main crater. Here we focus on the dynamics of the Nyiragongo lava lake level and its relationship with the volcanic plumbing system by describing the historical and recent lava lake activity and presenting new quantitative observations using close-range photogrammetry, a Stereographic Time-Lapse Camera (STLC) system and high-resolution satellite SAR and InSAR remote sensing. Results highlight that, contrary to the interpretation found in some recent publications, the lava lake drainages appear to be the consequence and not the cause of the 1977 and 2002 flank eruptions. Two types of short-term lava lake level variations are observed. The first one corresponds to cyclic metre-scale variations attributed to gas piston activity. The STLC data recorded in September 2011 show hour-scale gas piston cycles reaching up to 3.8 m, which are interpreted to be related to gas accumulation and release in the

  15. Bubbled lava from the floor of the Sea of Okhotsk

    Science.gov (United States)

    Baturin, G. N.; Dubinchuk, V. T.; Rashidov, V. A.

    2014-05-01

    A sample of bubbled lava raised from a submarine volcano in the Sea of Okhotsk was analyzed by means of electron microscopy and the ICP-MS technique. The outside of the sample is flecked with rounded micro- and macrocavities, and the inner part is characterized by a liquation structure. Along with this, the unstructured mass of the rock contains globular particles of nearly the same diameters as the cavities. The lava is close to andesites and volcanic ashes of Kamchatka Peninsula in the macro- and microelemental composition but different in the somewhat increased content of barium, strontium, lithium, niobium, tungsten, uranium, and thorium. It is suggested that the cavities were formed during the eruption of the submarine volcano owing to contact of the boiling gas-saturated lava with seawater accompanied by the ejection of ash, which was spread by marine currents over long distances.

  16. ESR dating at Mezmaiskaya Cave, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, A.R. [Department of Chemistry, Williams College, Williamstown, MA, 01267 (United States)]. E-mail: anne.r.skinner@williams.edu; Blackwell, B.A.B. [Department of Chemistry, Williams College, Williamstown, MA, 01267 (United States); Martin, Sara [Department of Chemistry, Williams College, Williamstown, MA, 01267 (United States); Ortega, A. [RFK Science Research Institute, Flushing, NY, 11366 (United States); Blickstein, J.I.B. [RFK Science Research Institute, Flushing, NY, 11366 (United States); Golovanova, L.V. [Laboratory of Prehistory, St. Petersburg (Russian Federation); Doronichev, V.B. [Laboratory of Prehistory, St. Petersburg (Russian Federation)

    2005-02-01

    Mezmaiskaya Cave has yielded more than 10,000 artifacts, thousands of very well preserved faunal remains, and hominin remains, found in seven Middle Paleolithic (Mousterian) and three Upper Paleolithic levels. A complete Neanderthal infant skeleton was preserved in anatomical juxtaposition lying on a large limestone block, overlain by the earliest Mousterian layer, Layer 3. Twenty-four skull fragments from a 1-2 year-old Neanderthal infant, showing post-mortem deformation, occurred in a pit originating in the Mousterian Layer 2 and penetrating into underlying layers 2A and 2B(1). Bone from Layer 2A was dated by AMS {sup 14}C at 35.8-36.3{+-}0.5 kyr BP. Direct dating of Neanderthal bone from Layer 3 gave an age of 29 kyr, but that is now considered to be due to contamination by modern carbon. Fourteen large mammal teeth from Layers 2 through 3 have been dated by standard electron spin resonance (ESR). Low U concentrations in both the enamel and dentine ensure that ESR ages do not depend significantly on the U uptake model, but do depend strongly on the sedimentary dose rates. Assuming a sedimentary water concentration equal to 20 wt%, ESR ages for the Mousterian layers range from 36.2 to 73.0{+-}5.0 ka.

  17. Building 887: An Aladdin's Cave for Physicists

    CERN Multimedia

    2001-01-01

    Building 887 on the Prévessin site is home to numerous experiments bringing together physicists and engineers from around the world. Its diversity makes the huge building a replica of CERN in miniature. The Installation unit of the SL EA group in front of the support structure for the ATLAS muon chambers. From left to right, seated: Pierre Gimenez, Yves Bonnet, Yves Naveau, Alain Pinget, Christian Becquet, Camille Adenot; standing: Philippe Guillot, Thierry Reynes, Monserrat Zurita-Perez, Claude Ferrari et Denis Gacon. The big wheel to be used for the ATLAS muon chambers (see below) is much the most spectacular installation currently occupying Building 887. But it is far from being the only attraction. Push open the heavy doors of this immense hall and it is a bit like entering a physicists' Aladdin's cave. The building, 55 metres wide and 300 metres long, is a treasure trove of engineering and technology, a CERN in miniature, housing dozens of collaborations from all over the world. With its 150...

  18. Toothpaste lava from the Barren Island volcano (Andaman Sea)

    Science.gov (United States)

    Sheth, Hetu C.; Ray, Jyotiranjan S.; Kumar, Alok; Bhutani, Rajneesh; Awasthi, Neeraj

    2011-04-01

    Toothpaste lava is a basaltic lava flow type transitional between pahoehoe and aa and has been described from Paricutin, Kilauea and Etna volcanoes. Here we describe a spectacular example of toothpaste lava, forming part of a recent (possibly 1994-95) aa flow on the active volcano of Barren Island (Andaman Sea). This flow of subalkalic basalt shows abundant squeeze-ups of viscous toothpasate lava near its entry into the sea. The squeeze-ups are sheets and slabs, up to several meters across and tens of centimeters thick, extruded from boccas. They are often prominently curved, have striated upper surfaces with close-spaced, en echelon linear ridges and grooves, broad wave-like undulations perpendicular to the striations, and sometimes, clefts. Textural, geochemical, and Sr-Nd isotopic data on the squeeze-ups and the exposed aa flow core indicate very crystal-rich, viscous, and isotopically very homogeneous lava. We envisage that a greatly reduced speed of this viscous flow at the coastline, possibly aided by a shallowing of the basal slope, led to lateral spreading of the flow, which caused tension in its upper parts. This, with continued (albeit dwindling) lava supply at the back, led to widespread tearing of the flow surface and extrusion of the squeeze-ups. The larger slabs, while extruding in a plastic condition, curved under their own weight, whereas their surfaces experienced brittle deformation, forming the en echelon grooves. The extruded, detached, and rotated sheets and slabs were carried forward for some distance atop the very slowly advancing aa core, before the flow solidified.

  19. Restoring Native Forest Understory: The Influence of Ferns and Light in a Hawaiian Experiment

    Directory of Open Access Journals (Sweden)

    Robert Shallenberger

    2013-03-01

    Full Text Available Ecological restoration is an increasingly important component of sustainable land management. We explore potential facilitative relationships for enhancing the cost-effectiveness of restoring native forest understory, focusing on two factors: (1 overstory shade and (2 possible facilitation by a fern (Dryopteris wallichiana, one of few native colonists of pasture in our montane Hawaiˈi study system. We planted 720 understory tree seedlings and over 4000 seeds of six species under six planting treatments: a full factorial combination of low, medium and high light, situating plantings in either the presence or absence of a mature fern. After three years, 75% of outplanted seedlings survived. Seedling survivorship was significantly higher in the presence of a fern (79% vs. 71% without a fern and in medium and low light conditions (81% vs. 64% in high light. Relative height was highest at low to medium light levels. After 2.2 years, 2.8% of the planted seeds germinated. We observed no significant differences in seed germination relative to light level or fern presence. Analyzing several approaches, we found nursery germination of seeds followed by outplanting ca. 20% less costly than direct seeding in the field. This study opens new questions about facilitation mechanisms that have the potential to increase the extent and effectiveness of restoration efforts.

  20. Edge effects on fern community in an Atlantic Forest remnant of Rio Formoso, PE, Brazil.

    Science.gov (United States)

    Silva, I A A; Pereira, A F N; Barros, I C L

    2011-05-01

    We have investigated how edge effects influence the fern community of Jaguarão Forest (08º 35' 49" S and 35º 15' 39" W), located in the district of Rio Formoso, Pernambuco, Brazil. A comparative analysis was made of the interior and edge of the fragment of forest, regarding the richness, abundance and diversity of ferns in the two areas. Six plots of 10 × 20 m were chosen, three in each area. A total of 381 ferns were recorded, which were distributed among 25 species, 17 genera and 12 families. The two areas (edge and interior) were found to differ, with distinct relative air humidities and temperatures (p = 0.00254 and p = 0.00019, respectively). The interior showed higher diversity (t = 7.251 and p = 0.018) and richness (t = 6.379 and p = 0.023) than the edge area, but the same abundance (t = 1.728; p = 0.226) as the edge. Regarding the composition of the flora, it was clear that the interior is a habitat completely distinct from the edge with regard to the fern community, given that only one species, Adiantum petiolatum Desv., was common to both environments. It was concluded that the edge effect causes a decrease in richness and abundance of the fern species found in Jaguarão Forest, where the more sensitive species are being replaced by species that are tolerant to the disturbance caused by the creation of an edge.

  1. Chemical constituents analysis and antidiabetic activity validation of four fern species from Taiwan.

    Science.gov (United States)

    Chen, Chen-Yu; Chiu, Fu-Yu; Lin, Yenshou; Huang, Wei-Jan; Hsieh, Po-Shiuan; Hsu, Feng-Lin

    2015-01-22

    Pterosins are abundant in ferns, and pterosin A was considered a novel activator of adenosine monophosphate-activated protein kinase, which is crucial for regulating blood glucose homeostasis. However, the distribution of pterosins in different species of ferns from various places in Taiwan is currently unclear. To address this question, the distribution of pterosins, glucose-uptake efficiency, and protective effects of pterosin A on β-cells were examined. Our results showed that three novel compounds, 13-chloro-spelosin 3-O-β-d-glucopyranoside (1), (3R)-Pterosin D 3-O-β-d-(3'-p-coumaroyl)-glucopyranoside (2), and (2R,3R)-Pterosin L 3-O-β-d-(3'-p-coumaroyl)-glucopyranoside (3), were isolated for the first time from four fern species (Ceratopteris thalictroides, Hypolepis punctata, Nephrolepis multiflora, and Pteridium revolutum) along with 27 known compounds. We also examined the distribution of these pterosin compounds in the mentioned fern species (except N. multiflora). Although all pterosin analogs exhibited the same effects in glucose uptake assays, pterosin A prevented cell death and reduced reactive oxygen species (ROS) production. This paper is the first report to provide new insights into the distribution of pterosins in ferns from Taiwan. The potential anti-diabetic activity of these novel phytocompounds warrants further functional studies.

  2. Ferns and lycopods--a potential treasury of anticancer agents but also a carcinogenic hazard.

    Science.gov (United States)

    Tomšík, Pavel

    2014-06-01

    Many species of seedless vascular plants-ferns and lycopods-have been used as food and folk medicine since ancient times. Some of them have become the focus of intensive research concerning their anticancer properties. Studies on the anticancer effect of crude extracts are being increasingly replaced by bioactivity-guided fractionation, as well as detailed assessment of the mechanism of action. Numerous compounds-especially flavonoids such as amentoflavone and protoapigenone, and also simpler phenolic compounds, steroids, alkaloids and terpenoids-were isolated and found to be cytotoxic, particularly pro-apoptotic, or to induce cell cycle arrest in cancer cell lines in vitro. In in vivo experiments, some fern-derived compounds inhibited tumour growth with little toxicity. On the other hand, many ferns-not only the well-known Bracken (Pteridium)-may pose a significant hazard to human health due to the fact that they contain carcinogenic sesquiterpenoids and their analogues. The objective of this review is to summarise the recent state of research on the anticancer properties of ferns and lycopods, with a focus on their characteristic bioactive constituents. The carcinogenic hazard posed by ferns is also mentioned.

  3. Knowledge-Based Estimation of Edible Fern Harvesting Sites in Mountainous Communities of Northeastern Japan

    Directory of Open Access Journals (Sweden)

    Toshiya Matsuura

    2013-12-01

    Full Text Available Once local expert knowledge regarding the harvesting of various non-timber forest products (NTFPs is lost, it is difficult to recover. We investigated whether the knowledge of expert forest harvesters can be used to determine the habitat distribution and harvesting sites of three popular edible wild ferns, i.e., ostrich fern (Matteuccia struthiopteris, bracken (Pteridium aquilinum, and royal fern (Osmunda japonica, in mountainous communities of western Fukushima, Japan. Using multi-criteria evaluation (MCE based on the analytic hierarchy process (AHP and geographic information system (GIS, we found that harvesters were easily able to recognize differences in the spatial characteristics of the habitat distribution of fern species due to both natural and anthropogenic factors. These factors were described by various GIS layers, such as vegetation and terrain features (e.g., gradient, aspect, and slope position derived from a 20-m digital elevation model (DEM. Harvesting sites were limited by their distance from a roadway, which differed among species. By comparison with the GPS records of actual harvesting sites, we estimated the potential harvesting sites of each fern species with reasonable accuracy, particularly for bracken. Our results show that the knowledge of expert forest harvesters can be quantified using MCE and GIS, which is useful for determining the spatial characteristics of NTFP harvesting and ensuring sustainable management practices.

  4. Soral Crypsis: Protective Mimicry of a Coccid on an Indian Fern

    Institute of Scientific and Technical Information of China (English)

    Biplab Patra; Subir Bera; R. James Hickey

    2008-01-01

    Herbivory with crypsis is not well documented in ferns. The present record of cryptic coloration of coccid Saissetia filicum Boisduval (Homoptera: Coccidae) to the sori of a fern species Asplenium nidus L. (Aspleniaceae) is unique. Predatory beetles (Jauravia sp., Coleoptera: Coccinellidae) that feed on the coccids, are suggested to be selective pressure for the development of the present homopteran soral crypsis. A higher rate of effective predation is noticed in the vegetative leaves than the fertile leaves. Aggressive ants were found harvesting honeydew secretions from the coccids and defending the trophobionts as well as the host fern from their natural enemies. In addition, a possible three-way mutualistic relationship among the coccids, its host fern and the tending ant is suggested. Differential numbers of coccids on vegetative and fertile leaves is correlated with their phenol content and degree of predation by beetles. Such coloration mimicry by the coccids may enable them to obtain the necessary blend of sorus of the host fern needed to evade beetle detection and attack.

  5. Impact of Environmental Factors on the Spectral Characteristics of Lava Surfaces: Field Spectrometry of Basaltic Lava Flows on Tenerife, Canary Islands, Spain

    Directory of Open Access Journals (Sweden)

    Long Li

    2015-12-01

    Full Text Available We report on spectral reflectance measurements of basaltic lava flows on Tenerife Island, Spain. Lava flow surfaces of different ages, surface roughness and elevations were systematically measured using a field spectroradiometer operating in the range of 350–2500 nm. Surface roughness, oxidation and lichen coverage were documented at each measured site. Spectral properties vary with age and morphology of lava. Pre-historical lavas with no biological coverage show a prominent increase in spectral reflectance in the 400–760 nm range and a decrease in the 2140–2210 nm range. Pāhoehoe surfaces have higher reflectance values than ʻaʻā ones and attain a maximum reflectance at wavelengths < 760 nm. Lichen-covered lavas are characterized by multiple lichen-related absorption and reflection features. We demonstrate that oxidation and lichen growth are two major factors controlling spectra of Tenerife lava surfaces and, therefore, propose an oxidation index and a lichen index to quantify surface alterations of lava flows: (1 the oxidation index is based on the increase of the slope of the spectral profile from blue to red as the field-observed oxidation level strengthens; and (2 the lichen index is based on the spectral reflectance in the 1660–1725 nm range, which proves to be highly correlated with lichen coverage documented in the field. The two spectral indices are applied to Landsat ETM+ and Hyperion imagery of the study area for mapping oxidation and lichen coverage on lava surfaces, respectively. Hyperion is shown to be capable of discriminating different volcanic surfaces, i.e., tephra vs. lava and oxidized lava vs. lichen-covered lava. Our study highlights the value of field spectroscopic measurements to aid interpretation of lava flow characterization using satellite images and of the effects of environmental factors on lava surface evolution over time, and, therefore, has the potential to contribute to the mapping as well as dating

  6. Tamarugite from Diana Cave (SW Romania) -first true karst occurrence

    Science.gov (United States)

    Pušcaš, C. M.; Onac, B. P.; Effenberger, H. S.; Povarǎ, I.

    2012-04-01

    Diana Cave is located within the town limits of Baile Herculane (SW Romania) and develops as a 14 m long, westward oriented, unique passage guided by the Diana fault [1]. At the far end of the cave, the thermo-mineral Diana Spring wells forth. In the early 1970s a mine gallery that intersected the cave was created to drain the water into a pumping station and the original cave passage was somewhat altered and reinforced with concrete. Today the concrete and the silty limestone cave walls are heavily corroded by H2SO4 outgassing from the hot water (ca. 50°C) and display abundant gypsum crusts, soggy aggregates of native S, and a variety of more exotic sulfates. Among them, a mineral that has been previously identified in caves only in connection to volcanic activity, either as thermal springs or fumaroles [2]: tamarugite [NaAl(SO4)26H2O]. It was [3] that first mentioned the occurrence of this Na and Al sulfate in Diana Cave, our research aiming to give a detailed description of this mineral, its paragenesis, and mechanisms of precipitation. Recently, tamarugite has also been identified in a sulfuric acid cave from Greece [4]. Along with powder X-ray diffractions coupled with Rietveld refinement, scanning electron microscope, and electron probe micro-analysis, δ18O and δ34S compositions of the sulfate mineral as well as precipitates from the water were analyzed to identify and better constrain the genesis of this rare sulfate. Regrettably, the crystal size of our specimens is inappropriate for identification by means of single crystal X-ray diffraction. Physical and chemical parameters of Diana Spring were as well measured on several occasions. Geochemical analysis suggests that the minute, white tamarugite flakes precipitated in Diana Cave as a result of the interactions between the thermo-mineral water or water vapor and the original limestone bedrock and concrete that blankets the mine gallery. [1] Povara, I., Diaconu, G., Goran, C. (1972). Observations pr

  7. Morphometric study of pillow-size spectrum among pillow lavas

    Science.gov (United States)

    Walker, George P. L.

    1992-08-01

    Measurements of H and V (dimensions in the horizontal and vertical directions of pillows exposed in vertical cross-section) were made on 19 pillow lavas from the Azores, Cyprus, Iceland, New Zealand, Tasmania, the western USA and Wales. The median values of H and V plot on a straight line that defines a spectrum of pillow sizes, having linear dimensions five times greater at one end than at the other, basaltic toward the small-size end and andesitic toward the large-size end. The pillow median size is interpreted to reflect a control exercised by lava viscosity. Pillows erupted on a steep flow-foot slope in lava deltas can, however, have a significantly smaller size than pillows in tabular pillowed flows (inferred to have been erupted on a small depositonal slope), indicating that the slope angle also exercised a control. Pipe vesicles, generally abundant in the tabular pillowed flows and absent from the flow-foot pillows, have potential as a paleoslope indicator. Pillows toward the small-size end of the spectrum are smooth-surfaced and grew mainly by stretching of their skin, whereas disruption of the skin and spreading were important toward the large-size end. Disruption involved increasing skin thicknesses with increasing pillow size, and pillows toward the large-size end are more analogous with toothpaste lava than with pahoehoe and are inferred from their thick multiple selvages to have taken hours to grow. Pseudo-pillow structure is also locally developed. An example of endogenous pillow-lava growth, that formed intrusive pillows between ‘normal’ pillows, is described from Sicily. Isolated pillow-like bodies in certain andesitic breccias described from Iceland were previously interpreted to be pillows but have anomalously small sizes for their compositions; it is now proposed that they may lack an essential attribute of pillows, namely, the development of bulbous forms by the inflation of a chilled skin, and are hence not true pillows. Para-pillow lava is

  8. Conveying Lava Flow Hazards Through Interactive Computer Models

    Science.gov (United States)

    Thomas, D.; Edwards, H. K.; Harnish, E. P.

    2007-12-01

    As part of an Information Sciences senior class project, a software package of an interactive version of the FLOWGO model was developed for the Island of Hawaii. The software is intended for use in an ongoing public outreach and hazards awareness program that educates the public about lava flow hazards on the island. The design parameters for the model allow an unsophisticated user to initiate a lava flow anywhere on the island and allow it to flow down-slope to the shoreline while displaying a timer to show the rate of advance of the flow. The user is also able to modify a range of input parameters including eruption rate, the temperature of the lava at the vent, and crystal fraction present in the lava at the source. The flow trajectories are computed using a 30 m digital elevation model for the island and the rate of advance of the flow is estimated using the average slope angle and the computed viscosity of the lava as it cools in either a channel (high heat loss) or lava tube (low heat loss). Even though the FLOWGO model is not intended to, and cannot, accurately predict the rate of advance of a tube- fed or channel-fed flow, the relative rates of flow advance for steep or flat-lying terrain convey critically important hazard information to the public: communities located on the steeply sloping western flanks of Mauna Loa may have no more than a few hours to evacuate in the face of a threatened flow from Mauna Loa's southwest rift whereas communities on the more gently sloping eastern flanks of Mauna Loa and Kilauea may have weeks to months to prepare for evacuation. Further, the model also can show the effects of loss of critical infrastructure with consequent impacts on access into and out of communities, loss of electrical supply, and communications as a result of lava flow implacement. The interactive model has been well received in an outreach setting and typically generates greater involvement by the participants than has been the case with static maps

  9. Contrasting P-T paths of shield and rejuvenated volcanism at Robinson Crusoe Island, Juan Fernández Ridge, SE Pacific

    Science.gov (United States)

    Reyes, Javier; Lara, Luis E.; Morata, Diego

    2017-07-01

    A remarkable expression of intraplate volcanism is the occurrence of evolutionary stages with important variations of magmatic processes and products. Plumbing systems and storage conditions seem to be different for shield and rejuvenated volcanism, two classical stages notably preserved in Robinson Crusoe Island, Juan Fernández Ridge in the SE Pacific Ocean. We here present first order geochemical features for rocks from both shield and rejuvenated stages and through geothermobarometry and textural analysis we unravel their contrasting ascent and storage history. The shield stage ( 3.8 Ma) is represented by a 900 m thick sequence of basalt, picrobasalt and picrite lava flows forming subsets according their chemistry and mineralogy: 'differentiated', 'near-primitive' and 'olivine-rich' lavas. Pressure estimates for in equilibrium assemblages are < 3.2 kbar, and temperature ranges around 1321 °C for the 'near-primitive' and 1156-1181 °C for the 'differentiated' groups. Volcanic rocks from the rejuvenated stage ( 0.9 Ma) fill the eroded morphology of the shield pile with basanite and picrite lava flows with two compositional varieties: the primitive 'high-Mg' group that crystallized clinopyroxene at pressures < 3.7 kbar and olivine at temperatures in the range 1316-1354 °C; and the 'low-Mg' group that carries notably zoned crystals formed at a wide range of pressures (0-10.8 kbar) and temperatures (1256-1295 °C). This allows us to infer contrasting patterns of ascent and storage during these archetypical stages in Robinson Crusoe Island, which also controlled volcanic processes on surface and finally shaped the island. We propose the existence of shallow magmatic reservoirs in the shield stage, where the ascending magmas would have been stored and differentiated. On the other hand, rejuvenated magmas experimented rapid ascent with polybaric crystallization and sometimes short-time storage in low-volume reservoirs. Similar conditions have been proposed in other

  10. Arsenic bioavailability in the soil amended with leaves of arsenic hyperaccumulator, Chinese brake fern (Pteris vittata L.)

    NARCIS (Netherlands)

    Du, X.; Cui, Y.S.; Weng, L.P.; Cao, Q.; Yang Zhu, Yang

    2008-01-01

    An incubation experiment was carried out to better understand the fate of As during the decomposition of As-rich Chinese brake fern (Pteris vittata L.) leaves and to assess As bioavailability in soil. Dried fern leaves with an As concentration of 1,150 +/- 14 microg/g were amended with unpolluted so

  11. Plastome sequences of Lygodium japonicum and Marsilea crenata reveal the genome organization transformation from basal ferns to core leptosporangiates.

    Science.gov (United States)

    Gao, Lei; Wang, Bo; Wang, Zhi-Wei; Zhou, Yuan; Su, Ying-Juan; Wang, Ting

    2013-01-01

    Previous studies have shown that core leptosporangiates, the most species-rich group of extant ferns (monilophytes), have a distinct plastid genome (plastome) organization pattern from basal fern lineages. However, the details of genome structure transformation from ancestral ferns to core leptosporangiates remain unclear because of limited plastome data available. Here, we have determined the complete chloroplast genome sequences of Lygodium japonicum (Lygodiaceae), a member of schizaeoid ferns (Schizaeales), and Marsilea crenata (Marsileaceae), a representative of heterosporous ferns (Salviniales). The two species represent the sister and the basal lineages of core leptosporangiates, respectively, for which the plastome sequences are currently unavailable. Comparative genomic analysis of all sequenced fern plastomes reveals that the gene order of L. japonicum plastome occupies an intermediate position between that of basal ferns and core leptosporangiates. The two exons of the fern ndhB gene have a unique pattern of intragenic copy number variances. Specifically, the substitution rate heterogeneity between the two exons is congruent with their copy number changes, confirming the constraint role that inverted repeats may play on the substitution rate of chloroplast gene sequences.

  12. 76 FR 45649 - Notice of Final Federal Agency Actions on I-5: Fern Valley Interchange Project: Jackson County, OR

    Science.gov (United States)

    2011-07-29

    ... Federal Highway Administration Notice of Final Federal Agency Actions on I-5: Fern Valley Interchange... the meaning of 23 U.S.C. 139(l)(1). The actions relate to a proposed highway project, I-5: Fern Valley... Administration, 530 Center Street, NE., Suite 420, Salem, Oregon 97301, Telephone: (503) 316-2559. The I-5:...

  13. Arsenic bioavailability in the soil amended with leaves of arsenic hyperaccumulator, Chinese brake fern (Pteris vittata L.)

    NARCIS (Netherlands)

    Du, X.; Cui, Y.S.; Weng, L.P.; Cao, Q.; Yang Zhu, Yang

    2008-01-01

    An incubation experiment was carried out to better understand the fate of As during the decomposition of As-rich Chinese brake fern (Pteris vittata L.) leaves and to assess As bioavailability in soil. Dried fern leaves with an As concentration of 1,150 +/- 14 microg/g were amended with unpolluted

  14. Use of rbcL and trnL-F as a two-locus DNA barcode for identification of NW-European ferns: an ecological perspective

    NARCIS (Netherlands)

    Groot, de G.A.; During, H.J.; Maas, J.W.; Schneider, H.; Erkens, R.H.J.

    2011-01-01

    Although consensus has now been reached on a general two-locus DNA barcode for land plants, the selected combination of markers (rbcL + matK) is not applicable for ferns at the moment. Yet especially for ferns, DNA barcoding is potentially of great value since fern gametophytes—while playing an esse

  15. Structural and hydrological controls on the development of a river cave in marble (Tapagem Cave - SE Brazil

    Directory of Open Access Journals (Sweden)

    William Sallun Filho

    2015-01-01

    Full Text Available Tapagem Cave (or Devil’s Cave is a river cave developed in the dolomite marble karst of the Serra do André Lopes (State of São Paulo, southeastern Brazil. Although this region is a plateau with significant variation in elevation and a humid subtropical climate, the cave is an anomalous feature in the André Lopes karst because there are few other caves. The marble, which is in a synclinal structure with subjacent phyllites, is a karst aquifer perched above the regional base level (Ribeira River and has little allogenic recharge. The cave developed on a secondary anticline on the northwest flank of the marble synform forming a blind valley, the Tapagem River sink, that is an underground tributary of Ostras River. Development of the cave is due to the entrenchment of the Ostras through-valley and the large allogenic catchment area of the sink. In plan view, the morphology of the cave can be divided into three different sectors. The first sector, known as the Tourist Sector, has extensive collapse rooms, fossil passages and a variety of speleothems of notable dimensions. The second and most extensive sector is the river passage, which is a sinuous gallery controlled by marble banding with NE-SW cleavage and NW-SE fractures. In cross-section, the passages are vadose canyons up to 70 m in height, controlled by the marble banding. Four NW-SE diabase dykes in this passage do not affect its direction in plan view. The third sector is an extensive network of passages and collapse rooms, which are interlaced in plan view and on different levels, forming a maze pattern. Initially, the Tapagem and Ostras Rivers developed on a gentle surface and flowed into the Ribeira River. With the entrenchment of the Ostras through-valley, the Tapagem River partially infiltrated via a paleosink into the upper passage of the “Erectus Room," remaining a half-blind valley. Following a series of collapses and obstructions, the River next infiltrated via the current

  16. Identifying Source Mixing and Examining Water Chemistry Variations: The Carroll Cave - Toronto Springs System

    Science.gov (United States)

    Located in the Missouri Ozarks, Carroll Cave is a dendritic stream cave system, formed in Ordivician Gasconade dolomite. In 2002, a new survey effort was launched under the auspices of the Carroll Cave Conservancy to provide a comprehensive map of the system. Since that time, 29.89 km of estimated p...

  17. Distribution of meiofaunal abundances in a marine cave complex with secondary openings and freshwater filtrations

    DEFF Research Database (Denmark)

    Riera, Rodrigo; Monterroso, Óscar; Núñez, Jorge

    2017-01-01

    ). Meiofaunal communities (0.062–0.5-mm body size) have been largely neglected in ecological studies about communities inhabiting sea caves. In the present study, we analysed meiofaunal communities from Los Cerebros cave, a shallow marine cave (3–8 m in depth, 80 m long), with secondary openings in the inner...

  18. A Framework for Aligning Instructional Design Strategies with Affordances of CAVE Immersive Virtual Reality Systems

    Science.gov (United States)

    Ritz, Leah T.; Buss, Alan R.

    2016-01-01

    Increasing availability of immersive virtual reality (IVR) systems, such as the Cave Automatic Virtual Environment (CAVE) and head-mounted displays, for use in education contexts is providing new opportunities and challenges for instructional designers. By highlighting the affordances of IVR specific to the CAVE, the authors emphasize the…

  19. Evidence for radiations of cheilanthoid ferns in the Greater Cape Floristic Region

    DEFF Research Database (Denmark)

    Eiserhardt, Wolf L.; Rohwer, Jens G.; Russell, Stephen J.;

    2011-01-01

    adapted cheilanthoid ferns. To test this hypothesis with special emphasis on the alternative hypothesis of frequent colonization, the phylogenetic relations, divergence times, and ancestral areas of the cheilanthoid ferns of the GCFR and adjacent regions are investigated. The dataset includes 22...... cheilanthoid fern species occurring in the GCFR. With two exceptions, all GCFR-endemics are part of two clades that diversified in the Afro-Madagascan region. The GCFR-endemics are further concentrated in three high-endemism subclades that did not originate simultaneously, but within the timeframe...... of angiosperm Cape Clades diversification. According to ancestral area reconstructions the ancestors of the two larger Afro-Madagascan clades were likely GCFR-endemic, and a substantial part of the diversification history of these clades took place in the GCFR. The high diversity of cheilanthoids in the GCFR...

  20. Volatile organic compounds in the strongly fragrant fern genus Melpomene (Polypodiaceae).

    Science.gov (United States)

    Kessler, M; Connor, E; Lehnert, M

    2015-03-01

    Volatile organic compounds (VOCs) are common among plants, both as attractants for pollinators and as defence against herbivores. While much studied among flowering plants, the prevalence and function of VOCs among ferns is little known. Using headspace sorption and gas chromatography, we analysed the VOCs of dried specimens of six species of grammitid fern (Polypodiaceae), including two species of the genus Melpomene, which is characterised by a distinctive sweet smell. We identified 38 VOCs, including 22 not previously recorded among ferns. The two species of Melpomene had distinct VOC cocktails, including 12 substances not found in the other four studied genera, mainly involving fatty acid derivatives (FADs) and aromatics. We propose that these VOCs have, at least in part, a function in herbivore defence, but note that the VOC bouquet of Melpomene is distinct from that typically found in angiosperms.

  1. Identifying potential habitat for the endangered Aleutian shield fern using topographical characteristics

    Science.gov (United States)

    Duarte, Adam; Wolcott, Daniel M.; Chow, T. Edwin

    2012-01-01

    The Aleutian shield fern Polystichum aleuticum is endemic to the Aleutian archipelago of Alaska and is listed as endangered pursuant to the U.S. Endangered Species Act. Despite numerous efforts to discover new populations of this species, only four known populations are documented to date, and information is needed to prioritize locations for future surveys. Therefore, we incorporated topographical habitat characteristics (elevation, slope, aspect, distance from coastline, and anthropogenic footprint) found at known Aleutian shield fern locations into a Geographical Information System (GIS) model to create a habitat suitability map for the entirety of the Andreaonof Islands. A total of 18 islands contained 489.26 km2 of highly suitable and moderately suitable habitat when weighting each factor equally. This study reports a habitat suitability map for the endangered Aleutian shield fern using topographical characteristics, which can be used to assist current and future recovery efforts for the species.

  2. Effect of linear alkyl benzene sulfonate on germination of spores of the aquatic fern Ceratopteris thalictroides

    Energy Technology Data Exchange (ETDEWEB)

    Singh, J.; Devi, S. (National Botanical Research Institute, Lucknow (India))

    1989-07-01

    Validity of fern spore germination bioassays for the effects of environmental pollution was established by many researchers. Some workers studied the phytotoxicity of linear alkyl benzene sulfonate (LAS) on the spores of Diplazium esculentum and observed that LAS levels above 0.001% are toxic to fern spores. Water pollution due to synthetic detergents has been increasing continuously during the last few years due to their extensive use in domestic life, agriculture and industry. These detergents are among the most common pollutants responsible for water pollution. In view of this fact, the phytotoxicity of LAS on germination of an aquatic fern Ceratopteris thalictroides spores was studied. However, in these studies, only germination pattern was taken as index and no observations were made on the developmental stages.

  3. Fossil invertebrates records in cave sediments and paleoenvironmental assessments: a study of four cave sites from Romanian Carpathians

    Directory of Open Access Journals (Sweden)

    O. T. Moldovan

    2015-06-01

    Full Text Available Fossil invertebrates from cave sediments have been recently described as a potential new proxy for paleoenvironment and used in cross-correlations with alternate proxy records from cave deposits. Here we present the results of a fossil invertebrates study in four caves from two climatically different regions of the Romanian Carpathians, to complement paleoenvironmental data previously reported. Oribatid mites and ostracods are the most common invertebrates in the studied cave sediments. Some of the identified taxa are new for science, and most of them are indicative for either warm/cold stages or dry/wetter oscillations. In two caves the fossil invertebrates records indicate rapid climate oscillations during times known for a relatively stable climate. By corroborating the fossil invertebrates' record with the information given by magnetic properties and sediment structures, complementary data on past vegetation, temperatures, and hydraulic regimes could be gathered. This paper analyses the potential of fossil invertebrate records as a paleoenvironmental proxy, potential problems and pitfalls.

  4. An Early Cretaceous root-climbing epiphyte (Lindsaeaceae) and its significance for calibrating the diversification of polypodiaceous ferns.

    Science.gov (United States)

    Schneider, H; Kenrick, P

    2001-05-01

    The discovery of fossilised roots of a lindsaeoid fern within the trunk of the extinct tree fern Tempskya provides new fossil evidence for Lindsaeaceae in the Mesozic, as well as the first direct evidence of an ecological association between Tempskya and root-climbing epiphytes. Data were collected from permineralised Tempskya trunks from the Aspen Shale (Early Cretaceous, Albian), Wyoming (USA). The roots of the lindsaeoid fossil are clearly distinguishable from those of Tempskya and other living ferns based on a suite of distinctive anatomical features, which are described in detail. The foliage is unknown. The new fossil is interpreted as a root climber, and comparisons are made with similar living species in Lindsaea subgenus Odontoloma (Lindsaeaceae). The documentation of Lindsaeaceae in the Early Cretaceous adds to a small but growing body of data on the diversification of polypodiaceous ferns during this important period. These recent discoveries point to a much earlier (Early Cretaceous) crown group radiation of polypodiaceous ferns than previously suspected.

  5. Aggregate Resources Study, Cave and Steptoe Valleys, Nevada.

    Science.gov (United States)

    1981-09-25

    Quartzite Creek Range 8 CV-AS Bgan Range Do Dolomite 9 CV-A9 Cave Valley Ls Limestone 10 Cv-Xf0- Egan Range Qtz Quartzite 11 CV-All Egan Range LS...Limestone 12 CV-A12 Cave Valley Aaf a Sandy Gravel G-GM 13 CV-A13 Bgan Range Vii Quartz Latite 14 CV-A14 Cave Valley Ls Limestone 7r 7 FIELD OBSERVATIONS...SO-A2 Bgan Range Vu Dacitic Ash-flow Tuff 25 SO-A3 Steptoe Aalf Sandy Gravel GP-GM Valley 26 SO-A4 Steptoe Aafs Sandy Gravel GE-GM Valley 27 S0-A5

  6. Microbial Communities and Associated Mineral Fabrics in Altamira Cave, Spain

    Directory of Open Access Journals (Sweden)

    Cuezva Soledad

    2009-01-01

    Full Text Available Evidences of microbial colonizations were observed in Altamira Cave, Spain. These consisted of distinct small coloured colonies, bothon walls and ceiling, mainly located in the area near the cave entrance, which progressed until reaching the Polychromes Hall. Thecolonizations were characterized by a high morphological and microstructural variability and related to biomineralization processes.Two main types of CaCO3 deposits were related to the colonies: rosette- or nest-like aggregates of rhombohedral calcite crystals, andspheroid to hemispheroid CaCO3 elements. Colonies distribution seems to be controlled by microenvironmental conditions inside thecavity. The areas of the cave showing higher temperature, relative humidity, and CO2 concentration fluctuations presented a minorbiomineralization capability.

  7. Chromatic perception of non-invasive lighting of cave paintings

    Science.gov (United States)

    Zoido, Jesús; Vazquez, Daniel; Álvarez, Antonio; Bernabeu, Eusebio; García, Ángel; Herraez, Juán A.; del Egido, Marian

    2009-08-01

    This work is intended to deal with the problems which arise when illuminanting Paleolithic cave paintings. We have carried out the spectral and colorimetric characterization of some paintings located in the Murcielagos (bats) cave (Zuheros, Córdoba, Spain). From this characterization, the chromatic changes produced under different lighting conditions are analysed. The damage function is also computed for the different illuminants used. From the results obtained, it is proposed an illuminant whose spectral distribution diminishes the damage by minimizing the absorption of radiation and optimises the color perception of the paintings in this cave. The procedure followed in this study can be applied to optimise the lighting systems used when illuminating any other art work

  8. FERN – a Java framework for stochastic simulation and evaluation of reaction networks

    Directory of Open Access Journals (Sweden)

    Zimmer Ralf

    2008-08-01

    Full Text Available Abstract Background Stochastic simulation can be used to illustrate the development of biological systems over time and the stochastic nature of these processes. Currently available programs for stochastic simulation, however, are limited in that they either a do not provide the most efficient simulation algorithms and are difficult to extend, b cannot be easily integrated into other applications or c do not allow to monitor and intervene during the simulation process in an easy and intuitive way. Thus, in order to use stochastic simulation in innovative high-level modeling and analysis approaches more flexible tools are necessary. Results In this article, we present FERN (Framework for Evaluation of Reaction Networks, a Java framework for the efficient simulation of chemical reaction networks. FERN is subdivided into three layers for network representation, simulation and visualization of the simulation results each of which can be easily extended. It provides efficient and accurate state-of-the-art stochastic simulation algorithms for well-mixed chemical systems and a powerful observer system, which makes it possible to track and control the simulation progress on every level. To illustrate how FERN can be easily integrated into other systems biology applications, plugins to Cytoscape and CellDesigner are included. These plugins make it possible to run simulations and to observe the simulation progress in a reaction network in real-time from within the Cytoscape or CellDesigner environment. Conclusion FERN addresses shortcomings of currently available stochastic simulation programs in several ways. First, it provides a broad range of efficient and accurate algorithms both for exact and approximate stochastic simulation and a simple interface for extending to new algorithms. FERN's implementations are considerably faster than the C implementations of gillespie2 or the Java implementations of ISBJava. Second, it can be used in a straightforward

  9. Medical illustration: from caves to cyberspace.

    Science.gov (United States)

    Tsafrir, J; Ohry, A

    2001-06-01

    The human body has been depicted in ancient cave-paintings, in primitively sculpted figures, and through all the ages in various forms of artistic expression. The earliest medical texts were descriptive but not illustrated. Later, as it became clear that knowledge of the human body and all its systems was essential to the practice of healing, texts were accompanied by illustrations which became an integral part of the teaching process. The illustrators included artists, whose interest was primarily artistic, but who were sometimes employed by surgeons or physicians to illustrate their texts. Occasionally, the physicians or scientists accompanied their texts with their own illustrations, and in the last century, medical illustration, in its infinite variety of techniques, has been developed as a profession in its own right. As knowledge was extended, permitted by social and cultural change, as well as by technological advances, the types of illustrations have ranged from gross anatomy through dissections showing the various organ systems, histological preparations, and radiological images, right up to the computerized digital imagery that is available today, which allows both static and dynamic two- and three-dimensional representations to be transmitted electronically across the world in a matter of seconds. The techniques used to represent medical knowledge pictorially have been as varied as the illustrators themselves, involving drawing, engraving, printing, photography, cinematography and digital processing. Each new technique has built on previous experience to broaden medical knowledge and make it accessible to an ever-widening audience. This vast accumulation of pictorial material has posed considerable problems of storage, cataloguing, retrieval, display and dissemination of the information, as well as questions of ethics, validity, manipulation and reliability. This paper traces these developments, illustrating them with representative examples drawn from

  10. Subglacial lava propagation, ice melting and heat transfer during emplacement of an intermediate lava flow in the 2010 Eyjafjallajökull eruption

    Science.gov (United States)

    Oddsson, Björn; Gudmundsson, Magnús T.; Edwards, Benjamin R.; Thordarson, Thorvaldur; Magnússon, Eyjólfur; Sigurðsson, Gunnar

    2016-07-01

    During the 2010 Eyjafjallajökull eruption in South Iceland, a 3.2-km-long benmoreite lava flow was emplaced subglacially during a 17-day effusive-explosive phase from April 18 to May 4. The lava flowed to the north out of the ice-filled summit caldera down the outlet glacier Gígjökull. The flow has a vertical drop of about 700 m, an area of ca. 0.55 km2, the total lava volume is ca. 2.5·107 m3 and it is estimated to have melted 10-13·107 m3 of ice. During the first 8 days, the lava advanced slowly (caldera where the ice was 60-100 m thick. This subglacial lava flow was emplaced along meltwater tunnels under ice for the entire 3.2 km of the flow field length and constitutes 90 % of the total lava volume. The remaining 10 % belong to subaerial lava that was emplaced on top of the subglacial lava flow in an ice-free environment at the end of effusive activity, forming a 2.7 km long a'a lava field. About 45 % of the thermal energy of the subglacial lava was used for ice melting; 4 % was lost with hot water; about 1 % was released to the atmosphere as steam. Heat was mostly released by forced convection of fast-flowing meltwater with heat fluxes of 125-310 kWm-2.

  11. Late Holocene lava flow morphotypes of the northern Harrat Rahat, Kingdom of Saudi Arabia: implications for the description of continental lava fields

    Science.gov (United States)

    Murcia, H. F.; Nemeth, K.; Moufti, R.; Lindsay, J. M.; El-Masry, N.; Cronin, S. J.; Qaddah, A.; Smith, I. E.

    2013-12-01

    Lava morphotype refers to the surface morphology of a lava flow after solidification. In Saudi Arabia, young and well-preserved mafic lava fields (Harrats) display a wide range of these morphotypes. This study examines those exhibited by four of the post-4500 yrs. BP lava fields in the northern Harrat Rahat (morphotypes, and proposes a preliminary correlation with whole-rock chemical composition. The Harrat Rahat lava fields include one or more lobes that may extend over 20 km from the source, with thicknesses varying between 1-2 m up to 12 m. Each lava flow episode covered areas between ~32 and ~61 km2, with individual volumes estimated between ~0.085 and ~0.29 km3. The whole-rock chemical compositions of these lavas lie between 44.3 to 48.4% SiO2, 9.01-4.28% MgO and 3.13-6.19% NaO+K2O. Seven different morphotypes with several lava structures are documented: Shelly, Slabby, Rubbly-pahoehoe, Platy, Cauliflower, Rubbly-a'a, and Blocky. These may be related to the shear strain and/or apparent viscosity of the lava flows formed from typical pahoehoe (pure or Hawaiian-pahoehoe, or sheet-pahoehoe). The well-preserved lava fields in Harrat Rahat allow the development of a more expanded classification scheme than has been traditionally applied. In addition to the whole-rock composition, these morphotypes may be indicators of other properties such as vesicularity, crystallization, effusion mechanism, as well as significant along-flow variations in topography and lava thickness and temperature that modify the rheology. The linearity of transitions between morphotypes observed in the lava fields suggest that real time forecasting of the evolution of lava flows might be possible.

  12. Thermophysical properties of the Lipari lavas (Southern Tyrrhenian Sea

    Directory of Open Access Journals (Sweden)

    D. Russo

    1997-06-01

    Full Text Available Results of thermophysical investigations into the lavas of the island of Lipari (Southern Tyrrhenian Sea are presented. Samples selected for laboratory measurements belong to four main magmatic cycles, which produced basaltic-andesitic, andesitic and rhyolitic lavas. The wet-bulk density and the thermal conductivity measured on 69 specimens range from 1900 to 2760 kg m-3 and from 1.02 to 2.88 W m-1 K-1, respectively. Porosity is never negligible and its influence on density is maximum in rhyolites of the third cycle. The thermal conductivity is also influenced by the amount of glass. Rhyolitic obsidians show values lower than other rhyolites, although the latter rocks have a larger average porosity. The radioactive heat production determined on 36 specimens varies with the rock type, depending on the amount of U, Th and K. In basic lavas of the first cycle its value is 0.95°± 0.30 mW m-3, while in rhyolites of the fourth cycle it attains 6.68°±0.61 mW m-3. A comparison between results of g-ray spectrometry and X-ray fluorescence points out that the assumption of equilibrium in the decay series of the isotopic elements seems fulfilled. The information obtained is useful not only for the interpretation of geophysical surveys but also for the understanding of the geochemical characteristics of lavas.

  13. Not only in the temperate zone: independent gametophytes of two vittarioid ferns (Pteridaceae, Polypodiales) in East Asian subtropics.

    Science.gov (United States)

    Kuo, Li-Yaung; Chen, Cheng-Wei; Shinohara, Wataru; Ebihara, Atsushi; Kudoh, Hiroshi; Sato, Hirotoshi; Huang, Yao-Moan; Chiou, Wen-Liang

    2017-03-01

    Independent gametophyte ferns are unique among vascular plants because they are sporophyteless and reproduce asexually to maintain their populations in the gametophyte generation. Such ferns had been primarily discovered in temperate zone, and usually hypothesized with (sub)tropical origins and subsequent extinction of sporophyte due to climate change during glaciations. Presumably, independent fern gametophytes are unlikely to be distributed in tropics and subtropics because of relatively stable climates which are less affected by glaciations. Nonetheless, the current study presents cases of two independent gametophyte fern species in subtropic East Asia. In this study, we applied plastid DNA sequences (trnL-L-F and matK + ndhF + chlL datasets) and comprehensive sampling (~80%) of congeneric species for molecular identification and divergence time estimation of these independent fern gametophytes. The two independent gametophyte ferns were found belonging to genus Haplopteris (vittarioids, Pteridaceae) and no genetic identical sporophyte species in East Asia. For one species, divergence times between its populations imply recent oversea dispersal(s) by spores occurred during Pleistocene. By examining their ex situ and in situ fertility, prezygotic sterility was found in these two Haplopteris, in which gametangia were not or very seldom observed, and this prezygotic sterility might attribute to their lacks of functional sporophytes. Our field observation and survey on their habitats suggest microhabitat conditions might attribute to this prezygotic sterility. These findings point to consideration of whether recent climate change during the Pleistocene glaciation resulted in ecophysiological maladaptation of non-temperate independent gametophyte ferns. In addition, we provided a new definition to classify fern gametophyte independences at the population level. We expect that continued investigations into tropical and subtropical fern gametophyte floras will

  14. Preliminary investigations on fossil diversity variation of Mesozoic Marattialean ferns in China

    Institute of Scientific and Technical Information of China (English)

    Zikun JIANG; Yongdong WANG; and Ning TIAN

    2008-01-01

    The Marattiales is one of the oldest lineages of vascular plants with extensive fossil records dated back to the Carboniferous. Understanding the fossil diversity variation and distribution pattern is helpful for exploring the evolutionary history of this fern group. In this work, the preliminary analysis of diversity change and distribution of the Mesozoic Marattialean fossil records in China are reported covering the Triassic and Jurassic periods based on available published data. In addition, a brief discussion is made regarding to the potential causes for these variation and distribution of this fern group.

  15. Determination of heavy metals in soil and different parts of Diplazium esculentum (medicinal fern)

    Science.gov (United States)

    Jasim, Hind S.; Idris, Mushrifah; Abdullah, Aminah; Kadhum, A. A. H.

    2014-09-01

    Diplazium esculentum is a widely used medicinal fern in Malaysia and other regions worldwide. Heavy metals in plants should be determined because prolonged human intake of toxic trace elements, even at low doses, results in organ malfunction and causes chronic toxicity. Hence, substantial information should be obtained from plants that grow on soils containing high concentrations of heavy metals. This study aimed to determine the physicochemical characteristics of soil and heavy metal concentrations (Pb, Cr, Mn, Cu, and Zn) in different parts of D. esculentum and soil, which were collected from the fern garden of Universiti Kebangsaan Malaysia. Results showed that heavy metals were highly accumulated in D. esculentum roots.

  16. CLINICAL APPLICATION AND EVALUATION OF SALIVA FERNING TEST IN SJGREN S SYNDROME

    Institute of Scientific and Technical Information of China (English)

    丁玲; 唐燕

    2000-01-01

    ffeStnn6 Objectif L' dtude admit pour but d' aPPrdcier to wileur du test de foug4rimtion (Ferning Test ) adns ie diagnostic de xdrostwnie chez ies malaies atteints du Syndrew de Sjbgren (ss). methaes ho dchantillons dewtnd de alivefraiche out did Obtenus chez 78 malades avec ie diagnostic de SS etabli scion ies critsres de ~munautd Eurowinne et chez 80tdmoins dins. ie dchantillons out ate ~mind sons microscope ordinaire. In cristallimtion etait classifide en 4 type scion iePhenondne de fougdrimtion (ferning...

  17. A new species of fern of the genus Pteris (Filicales: Pteridaceae) endemic to Costa Rica.

    OpenAIRE

    Rojas Alvarado, Alexander Fco.; Palacios Ríos, Mónica

    2014-01-01

    Abstract: A new species of fern of the genus Pteris (Filicales: Pteridaceae) endemic to Costa Rica. The new fern species Pteris herrerae A. Rojas & M. Palacios, endemic to Costa Rica, is described. It differs from P. decurrens C. Presl in basal segments reduced to 1/5-1/2 of the next segment (vs. 2/3-3/4), basal pinnae not bifurcated (vs. bifurcated), pinnae apex mucronate (vs. acuminate) and segment apex undulate (vs. dentate). It differs from Pteris consanguinea in the elliptic pinnae (vs. ...

  18. DOWNFLOW code and LIDAR technology for lava flow analysis and hazard assessment at Mount Etna

    OpenAIRE

    Alessandro Fornaciai; Simone Tarquini; Massimiliano Favalli

    2011-01-01

    The use of a lava-flow simulation (DOWNFLOW) probabilistic code and airborne light detection and ranging (LIDAR) technology are combined to analyze the emplacement of compound lava flow fields at Mount Etna (Sicily, Italy). The goal was to assess the hazard posed by lava flows. The LIDAR-derived time series acquired during the 2006 Mount Etna eruption records the changing topography of an active lava-flow field. These short-time-interval, high-resolution topographic surveys provide a detailed...

  19. Rare cause of trigeminal neuralgia: Meckel's cave meningocele.

    Science.gov (United States)

    Alobaid, Abdullah; Schaeffer, Todd; Virojanapa, Justin; Dehdashti, Amir R

    2015-07-01

    The most common etiology of classic trigeminal neuralgia is vascular compression. However, other causes must be excluded. It is very unlikely that a meningocele presents with symptomatic trigeminal neuralgia. We present a rare case of a patient presenting with left trigeminal neuralgia. Thin-slice CT and MRI showed a transclival Meckel's cave meningocele. The patient underwent endoscopic repair of the meningocele, which resulted in complete resolution of her symptoms. Meckel's cave meningocele or encephalocele should be considered among the differential diagnoses of trigeminal neuralgia. Meningocele repair should be suggested as the first treatment option in this rare situation.

  20. Luminescence of Speleothems in Italian Gypsum Caves: Preliminary Report

    CERN Document Server

    Shopov, Yavor Y; Forti, Paolo

    2009-01-01

    The luminescence of 3 speleothem samples from the Acquafredda karst system and 1 from the Novella Cave (Gessi Bolognesi Natural Park, Italy) has been recorded using excitation by impulse Xe- lamp. All these carbonate speleothems are believed to be formed only from active CO2 from the air, because the bedrock of the cave consist of gypsum and does not contain carbonates. The obtained photos of luminescence record the climate changes during the speleothem growth. U/Th and 14C dating proved that studied speleothems started to grow since about 5,000 years ago. The detailed analyses of the luminescence records is still in progress.

  1. Spanish Civil War caves of Asturias in archaeology and memory

    OpenAIRE

    Fernández Fernández, J.; Moshenska, G.

    2016-01-01

    As the Spanish Civil War drew to a close, retreating Republican troops in the northern region of Asturias took refuge in caves in the mountains from the brutal victor’s justice of the Francoist forces. In this paper we examine three of these caves in the context of the Civil War experiences of the rural municipality of Santo Adriano, based on a combination of archaeological recording and oral history interviews. The paper focuses on the role of the La Ponte-Ecomuseum, a grassroots heritage or...

  2. Seasonal temperature variations controlling cave ventilation processes in Cueva Larga, Puerto Rico

    Directory of Open Access Journals (Sweden)

    Rolf Vieten

    2016-09-01

    Full Text Available Two years of cave monitoring investigate ventilation processes in Cueva Larga, a tropical cave in Puerto Rico. The cave is 1,440 m long with a large main passage (about 120,000 m3. Cave air pCO2 in the main passage varies seasonally, between 600 ppm in winter and 1,800 ppm in summer. The seasonal variability in cave pCO2 permits the estimation of a cave air exchange time of 36 ± 5 days and a winter ventilation rate of 3,300 ± 1,000 m3/day for the main cave passage. Calculations of virtual temperature and differences between cave and surface temperature indicate that the seasonal temperature cycle is the main driver of the alternation between a well-ventilated winter mode and a near-stagnant summer mode. The winter mode is characterized by a positive buoyancy contrast at night leading to maximal cave ventilation, while cave ventilation is at a minimum during summer. Between winter and summer, a transitional mode of partial cave ventilation is observed. On shorter time scales (diurnal to weekly, cave pCO2 is also influenced by atmospheric pressure but this variation is one order of magnitude lower than the seasonal pCO2 change. The cave morphology of Cueva Larga including its large volume, tubular shape and the obstructed cave entrance geometry are important boundary conditions for the observed ventilation patterns. Our findings emphasize that cave systems with varying morphology have to be studied individually in order to correctly describe ventilation processes.

  3. The first troglobitic Pseudonannolene from Brazilian iron ore caves (Spirostreptida: Pseudonannolenidae).

    Science.gov (United States)

    Iniesta, Luiz Felipe Moretti; Ferreira, Rodrigo Lopes

    2013-01-01

    Pseudonannolene spelaea n. sp. is the first strictly cave-dwelling species described for the family Pseudonannolenidae. It is found in iron ore caves in the Brazilian Amazon. The family Pseudonannolenidae is exclusively Neotropical and frequently found in caves of Brazil, from which 20 species are known. The new species is compared with its congeners and with related cave-dwelling species. The family Pseudonannolenidae is discussed, and comments are presented on the conservation status of the caves where the species is found, which potentially may be the target of anthropogenic impacts resulting from iron ore extraction.

  4. Application of electrical resistivity imaging on Divaška jama cave

    Directory of Open Access Journals (Sweden)

    Andrej Mihevc

    2011-12-01

    Full Text Available Electrical resistivity imaging (ERI is a widely used tool in geophysical survey of various subsurface structures. To establish its applicability for karst subsurface, ERI was conducted in Divača karst above caves of Trhlovca and Divaška jama and in its continuation as denuded cave on slopes of Radvanj collapse doline. Empty cave passages were not detected with ERI as electrical resistivity difference between voids and highly resistive carbonate bedrock is too small. On the other hand, denuded caves and cave sections, filled with loamy material, can be clearly distinguished.

  5. Dolomite in caves: Recent dolomite formation in oxic, non-sulfate environments. Castañar Cave, Spain

    OpenAIRE

    Alonso-Zarza, Ana María; Martín Pérez, Andrea

    2008-01-01

    Dolomite is a common mineral in the rock record but rare in recent superficial environments. Where it does occur, it is related to anoxic, sulfate-rich environments and microbial activity. The occurrence of some dolomite deposits in caves, however, indicates that dolomite formation is also possible in oxic, non-sulfate settings. Dolomite is forming at 17 °C and in oxic-vadose conditions on the host rocks and aragonite speleothems of the Castañar Cave, Cáceres, Spain. It appears as...

  6. A second species of Euscorpiops Vachon from caves in Vietnam (Scorpiones, Euscorpiidae, Scorpiopinae). Cave Euscorpiops scorpion from Vietnam.

    Science.gov (United States)

    Lourenço, Wilson R; Pham, Dinh-Sac

    2014-09-01

    Euscorpiops dakrong sp. n., belonging to the family Euscorpiidae Laurie, is described on the basis of one male and one female collected in the Dakrong Nature Reserve cave system, Dakrong District, Quang Tri Province, Vietnam. The new species presents most features exhibited by scorpions of the genus Euscorpiops, but it is characterized by a slender body and elongated pedipalps. This new scorpion taxon represents the second species of Scorpiopinae discovered in a cave system and may be yet another endemic element in the fauna of Vietnam. Some taxonomic propositions on the generic position of Scorpiops oligotrichus Fage, 1933 are also suggested.

  7. In situ thermal characterization of cooling/crystallizing lavas during rheology measurements and implications for lava flow emplacement

    Science.gov (United States)

    Kolzenburg, S.; Giordano, D.; Cimarelli, C.; Dingwell, D. B.

    2016-12-01

    Transport properties of natural silicate melts at super-liquidus temperatures are reasonably well understood. However, migration and transport of silicate melts in the Earth's crust and at its surface generally occur at sub-liquidus temperatures and in settings where the melts undergo crystallization under various cooling and/or decompression conditions. In such dynamic situations the occurrence of processes such as the release of latent heat during phase changes, viscous heating, thermal advection and -inertia, and changing heat capacity, all represent potential influences on the state, and thereby on the physico-chemical behavior of the system. To date, rheological data at sub-liquidus temperatures are scarce and cooling-rate dependent, disequilibrium rheological data are virtually absent. In fact, no in situ thermal characterization of liquid or multiphase mixtures during rheological experiments, under either static or dynamic thermal conditions has been presented to date. Here we describe a new experimental setup for in situ thermal characterization of cooling/crystallizing lavas during viscosity measurement at temperatures up to 1600 °C. We use this device to recover in situ, real-time, observations of the combined rheological and thermal evolution of natural, re-melted lava samples during the transient disequilibrium conditions characteristic of lava flows and shallow crustal magma migration and storage systems in nature. We present the calibration procedure and the method employed to recover the thermal evolution of an experimental sample during flow in varying shear regimes, assess the experimental uncertainty and show the ability of the apparatus to measure the release of latent heat of crystallization during transient rheological experiments. We further report the results from a first experimental study on the rheological and thermal evolution of a basaltic lava undergoing continuous cooling at a series of different cooling rates and discuss the

  8. Spotted hyena and steppe lion predation behaviours on cave bears of Europe - ?Late Quaternary cave bear extinction as result of predator stress

    Science.gov (United States)

    Diedrich, Cajus G.

    2010-05-01

    Cave bears hibernated in caves all over Eurasia (e.g. Rabeder et al., 2000) including alpine regions using mainly larger caves for this purpose. Late Quaternary spotted hyenas Crocuta crocuta spelaea instead occupied mainly areas close to the cave entrances as their dens (Diedrich and Žák 2006, Diedrich 2010). The largest predator, the steppe lion Panthera leo spelaea was only a sporadic cave dweller (Diedrich 2007b, 2009b). His presence and its remains from caves all over Europe can be recently explained best as result of imported carcasses after killing by their largest antagonists, the Late Quaternary spotted hyenas. In some cases the kill might have happened in the hyena den cave itself during the theft of prey remains by lions (Diedrich 2009a). Another reason of their remains in caves of Europe is the hunting onto the herbivorous cave bears, especially during hibernation times, when megafauna prey was less available in the open environments (Diedrich 2009c). These lion remains from caves of Europe, nearly all of which were from adult animals, provide evidence of active predation by lions onto cave bears even in medium high alpine regions (Diedrich 2009b, in review). Lion skeletons in European cave bear dens were therefore often found amongst originally articulated cave bear skeletons or scattered cave bear remains and even close to their hibernation nests (Diedrich et al. 2009c, in review). Not only lions fed on cave bears documented mainly by the large quantities of chewed, punctured and crushed cave bear long-bones; even damaged skulls reveal that hyenas scavenged primarily on cave bear carcasses which were mainly responsible for the destruction of their carcasses and bones (Diedrich 2005, 2009d). Predation and scavenging on cave bears by the two largest Late Quaternary predators C. c. spelaea and P. l. spelaea explains well the large quantity of fragmented cave bear bones over all European caves in low to medium high mountainous elevations, whereas in

  9. FURTHER NOTES ON THE FERN-GENUS HETEROGONIUM PRESL

    Directory of Open Access Journals (Sweden)

    R. E. HOLTTUM

    2015-11-01

    Full Text Available In the "Sarawak Museum Journal," volume V (1949, pages 156-166,I gave a revised account of the genus Heterogonium Presl, based on specimens in the Singapore herbarium. Dr M. A. Donk wrote subsequently pointing out that specimens at Bogor (Buitenzorg add materially to the information contained in that paper. The present paper gives the result of a study of the Bogor specimens. I am glad to express my gratitude to Dr Donk for calling my attention to species which I had overlooked when searching literature on Malaysian ferns for indications of affinity to Heterogonium. The Bogor material includes the type specimens of Acrostichum teysmannianum Bak., Phegopteris schizoloma v. A. v. R. Dryopteris sagenoides forma contracta v. A. v. R., Polybotrya nieuwenhuisii Racib. and Polybotrya nieuwenhuisii var. brooksii v. A. v. R., also many sheets of H. giganteum, and material of H. sagenoides from a wider geographic range than I had previously seen. Summarizing the results of the present paper, I have united H.nieuwenhuisii and H. stenosemioides of my former paper, and have also united H. saxicola with H. giganteum. Further, I now recognize a second exindusiate species allied to H. sagenoides; but the variation in pubescence among exindusiate specimens, as within the species H. sagenoides proper, is very considerable, and I find it very difficult to draw specific limits. It is likely that there are local races, but much more field work in many localities is necessary before one can speak with certainty about this or define their status taxonomically. One interesting fact is that no exindusiate specimens of this alliance have been found in the Malay Peninsula, whereas Peninsular collections of indusiate H. sagenoides aremore abundant than from any other area. It is especially the variation in pubescence among specimens of H. sagenoides, and the lack of clear-cut varieties or subspecies within the Malay Peninsula, that deters me from distinguishing more

  10. Assessment of the dose from radon and its decay products in the Bozkov dolomite cave.

    Science.gov (United States)

    Rovenská, K; Thinová, L; Zdímal, V

    2008-01-01

    The dose from radon and its progeny remains a frequently discussed problem. ICRP 65 provides a commonly used methodology to calculate the dose from radon. Our work focuses on a cave environment and on assessing the doses in public open caves. The differences in conditions (aerosol size distribution, humidity, radon and its progeny ratio, etc.) are described by the so-called cave factor j. The cave factor is used to correct the dose for workers which is calculated using the ICRP 65 recommendation. In this work, the authors have brought together measured data of aerosol size distribution, unattached and attached fraction activity, and have calculated the so-called cave factor for the Bozkov dolomite cave environment. The dose conversion factors based on measured data and used for evaluating the cave factor were calculated by LUDEP software, which implements HRTM ICRP66.

  11. Main karst and caves of Switzerland; El karst y las cuevas mas importantes de Suiza

    Energy Technology Data Exchange (ETDEWEB)

    Jeannin, P. Y.

    2016-07-01

    This paper presents an overview of the main karst areas and cave systems in Switzerland. The first part encloses descriptions of the main geological units that hold karst and caves in the country and summarizes a brief history of research and protection of the cave environments. The second part presents three regions enclosing large cave systems. Two regions in the Alps enclose some of the largest limestone caves in Europe: Siebenhengste (Siebenhengste cave system with ∼160 km and Barenschacht with 70 km) and Bodmeren-Silberen (Holloch cave system with 200 km and Silberen System with 39 km). These systems are also among the deepest with depths ranging between 880 and 1340 m. The third example is from the Jura Mountains (northern Switzerland). (Author)

  12. Recognition of microclimate zones through radon mapping, Lechuguilla Cave, Carlsbad Caverns National Park, New Mexico

    Science.gov (United States)

    Cunningham, K.I.; LaRock, E.J.

    1991-01-01

    Radon concentrations range from temperature and barometric pressure, similar to other Type 2 caves. Most of the cave is developed in three geographic branches beneath the entrance passages; these areas maintain Rn levels independent of surface effects, an indication that Rn levels in deep, complex caves or mines cannot be simply estimated by outside atmospheric parameters. These deeper, more isolated areas are subject to convective ventilation driven by temperature differences along the 477-m vertical extent of the cave. Radon concentrations are used to delineate six microclimate zones (air circulation cells) throughout the cave in conjunction with observed airflow data. Suspected surface connections contribute fresh air to remote cave areas demonstrated by anomalous Rn lows surrounded by higher values, the presence of mammalian skeletal remains, CO2 concentrations and temperatures lower than the cave mean, and associated surficial karst features.

  13. The occurrence of coliform bacteria in the cave waters of Slovak Karst, Slovakia.

    Science.gov (United States)

    Seman, Milan; Gaálová, Barbora; Cíchová, Marianna; Prokšová, Miloslava; Haviarová, Dagmar; Fľaková, Renáta

    2015-05-01

    The diversity and abundance of coliform bacteria (taxonomically enterobacterias), an important quality water indicator, were determined for four representative caves in Slovak Karst: Domica Cave, Gombasecká Cave, Milada Cave and Krásnohorská Cave. Three hundred and fifty-two enterobacterial isolates were successfully identified by biochemical testing (commercial ENTEROtest 24) and selected isolates confirmed by molecular techniques (PCR, 16S rDNA sequence analysis). A total of 39 enterobacterial species were isolated from cave waters, with predominance of Escherichia coli, Serratia spp. and Enterobacter spp. PCR amplification of lacZ gene is not specific enough to provide a reliable detection of coliform bacteria isolated from the environment. Sequence analysis of 16S rDNA confirmed that all of the selected isolates belong to the family Enterobacteriaceae. In general, physical and chemical parameters of cave waters in Slovak Karst corresponded to national drinking water quality standards.

  14. Preliminary results of excavations at Lincoln Cave, Sterkfontein, South Africa

    CSIR Research Space (South Africa)

    Reynolds, SC

    2003-05-01

    Full Text Available Recent excavations of undisturbed deposits within the Lincoln Cave, Sterkfontein, have conclusively demonstrated that at least one of the deposits is mid-late Pleistocene in age. The artefacts recovered from this excavation are in a datable context...

  15. Full Immersive Virtual Environment Cave[TM] in Chemistry Education

    Science.gov (United States)

    Limniou, M.; Roberts, D.; Papadopoulos, N.

    2008-01-01

    By comparing two-dimensional (2D) chemical animations designed for computer's desktop with three-dimensional (3D) chemical animations designed for the full immersive virtual reality environment CAVE[TM] we studied how virtual reality environments could raise student's interest and motivation for learning. By using the 3ds max[TM], we can visualize…

  16. Incidence of chromosomal aberrations and micronuclei in cave tour guides.

    Science.gov (United States)

    Bilban, M; Bilban-Jakopin, C; Vrhovec, S

    2001-01-01

    An analysis of structural chromosomal aberrations (SCA) and micronucleus tests (MN) were performed in 38 subjects, cave tour guides and in appropriate control group. The dominant type of chromosomal aberrations in tourist guides were chromosomal breaks (0.013 per cell) and acentric fragments (0.011 per cell). In the control group, these aberrations were present up to 0.008 on cells. Considering the analysed cells of the guides in total (33,556), the incidence of dicentric and rings range is below 0.0008 on cells, even though three dicentric and ring chromosoms were found already in the first 1000 in vitro metaphases of some guides. Only 0.0003 dicentrics and neither other translocations were found in control group (ambiental exposure). The incidence of micronuclei in cytokinesis blocked lymphocytes ranged from 12-32 per 500 CB cells in the cave tour guides and from 4-11 per 500 CB cells in control group. Measurements of radon and its daughters were performed at different locations in the cave. Annual doses from 40-60 mSv were estimated per 2000 work hours for cave guides. The changes found in the genome of somatic cells may be related to the exposure doses of radon and its daughters, although smoking should not be ignored.

  17. Designing a Virtual Reality Game for the CAVE

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2006-01-01

    remains uncommon and expensive. This paper aims to demonstrate the potential of VR games, and in particular games for the CAVE, now that affordable solutions are close to reach as more powerful hardware is available at low price. The focus is also on the methodology to be pursued while designing a VR game...

  18. Numerical analysis of application for induction caving roof

    Institute of Scientific and Technical Information of China (English)

    HU Jian-hua; ZHOU Ke-ping; LI Xi-bing; YANG Nian-ge; SU Jia-hong

    2005-01-01

    New method for handling roof of the base successive mining is proposed, which is induction caving in the roof. The key is that it is made certain to the station of the space-time in the induction caving roof, as the stress is released with the mining process. And applying the catastrophe theory, the influencing factors of induction caving roof are studied in the emptied areas, such as the mechanical property of the surrounding rock, the area of the gob,the scope and dimension of tensile stress. The results show that the key factor is the area of the gob to the method of the induction caving roof. Then according to the geology and the ore characteristic, the three dimension FEM mechanical model is built in Tongkeng Mine, the laws of the tensile stress are analyzed to the space and the time in the roof with the mining, then it is rational design to the mine step and time of the handing the roof.

  19. Inside the neutrino cave, close to the target complex

    CERN Multimedia

    1976-01-01

    The photo shows on the left the shielding of the target complex, T9 and T11 for the wide and narrow beams. The direction of the primary proton beam faces the camera. Between the shielding and the cave wall are housed the magnets cooling pipes. The pulley block allows displacements inside the shielding.

  20. [A case of epidermoid tumor inside the Meckel's cave].

    Science.gov (United States)

    Ohta, H; Ottomo, M; Nakamura, T; Yokota, A

    1997-10-01

    An epidermoid tumor inside the Meckel's cave is rare. The symptoms caused by this tumor include trigeminal neuralgia, facial hypesthesia and paresis of the 3rd, 4th and 6th nerves. A case of epidermoid tumor inside Meckel's cave was presented. A 54-year-old female who had complained of 3rd nerve palsy with right facial hypesthesia since 3 years before was referred to our clinic. Magnetic resonance imaging (MRI) showed the tumor at Meckel's cave. The tumor removal was performed using the orbito-zygomatic approach. To avoid injury of the internal carotid artery and nerves inside the cavernous sinus, removal of the tumor inside the capsule was carried out leaving the capsule. Postoperatively, the tumor removal was confirmed by MRI and improvement of the 3rd and the 5th nerve palsy was obtained three months after surgery. This case suggests that the capsule of the tumor inside the Meckel's cave should be allowed to remain to avoid injury of the adjacent 4th, 5th and 6th nerves and of the internal carotid artery.

  1. Cyathura specus, a new cave Isopod from Cuba

    NARCIS (Netherlands)

    Bowman, Thomas E.

    1965-01-01

    During the years 1958-1960, several shipments of specimens collected in the Caguanes Caves of Cuba were sent to the United States National Museum by GILBERTO SILVA TABOADA. Mr. SILVA'S collections included 3 specimens of a blind anthurid isopod, which I determined to be a species of Cyathura, simila

  2. Study of firedamp release in sub-level caving

    Energy Technology Data Exchange (ETDEWEB)

    Castano, F.S.; Sanz Delgado, M.A.; Iturriaga Trenor, S.; Alberdi Vinas, C.

    1988-01-01

    The field work developed in the pits of 'Hullera Vasco-Leonesa' in Santa Lucia (Leon) to control firedamp release is described. Conclusions obtained concerning gas emission, irregularity and firedamp balance in sub-level caving winning faces are discussed. Some definitions of basic concepts in firedamp studies are also included. 7 figs.

  3. Bacteria associated with the bleached and cave coral Oculina patagonica.

    Science.gov (United States)

    Koren, Omry; Rosenberg, Eugene

    2008-04-01

    The relative abundance of bacteria in the mucus and tissues of Oculina patagonica taken from bleached and cave (azooxanthellae) corals was determined by analyses of the 16S rRNA genes from cloned libraries of extracted DNA and from isolated colonies. The results were compared to previously published data on healthy O. patagonica. The bacterial community of bleached, cave, and healthy corals were completely different from each other. A tight cluster (>99.5% identity) of bacteria, showing 100% identity to Acinetobacter species, dominated bleached corals, comprising 25% of the 316 clones sequenced. The dominant bacterial cluster found in cave corals, representing 29% of the 97 clones sequenced, showed 98% identity to an uncultured bacterium from the Great Barrier Reef. Vibrio splendidus was the most dominant species in healthy O. patagonica. The culturable bacteria represented 0.1-1.0% of the total bacteria (SYBR Gold staining) of the corals. The most abundant culturable bacteria in bleached, cave, and healthy corals were clusters that most closely matched Microbulbifer sp., an alpha-proteobacterium previously isolated from healthy corals and an alpha-protobacterium (AB026194), respectively. Three generalizations emerge from this study on O. patagonica: (1) More bacteria are associated with coral tissue than mucus; (2) tissue and mucus populations are different; (3) bacterial populations associated with corals change dramatically when corals lack their symbiotic zooxanthellae, either as a result of the bleaching disease or when growing in the absence of light.

  4. Biological response to geochemical and hydrological processes in a shallow submarine cave

    Directory of Open Access Journals (Sweden)

    M. RADOLOVIĆ

    2015-07-01

    Full Text Available The Croatian coastal karst abounds in submerged caves that host a variety of environmental conditions depending on the geomorphology, depth and submarine groundwater discharge. One example is the Y-Cave, a shallow, mostly submerged, horizontal cave on Dugi Otok Island, on the eastern Adriatic coast. This study was aimed at examining the temporal and spatial variability of the marine cave environment, including temperature, salinity, light intensity, cave morphology and hydrodynamism, along with the dissolutional effect caused by the mixing of sea and freshwater. The general distribution of organisms in the Y-Cave was positively correlated to the light gradient and reduced water circulation, thus the highest species diversity and abundance were recorded in the front part of the cave. The phylum Porifera was the most dominant group, and the poriferan species diversity in the cave ranks among the ten highest in the Mediterranean. The middle part of the cave, although completely dark, hosts an abundant population of the gastropod Homalopoma sanguineum and clusters of the gregarious brachiopod Novocrania anomala, whose presence could be connected to tidal hydrodynamics. The absence/scarcity of sessile marine organisms and pronounced corrosion marks at shallow depths inside the cave suggest a freshwater impact in the upper layers of the water column. A year long experiment with carbonate tablets revealed three different, independent ongoing processes affected by the position in the cave: bioaccumulation, dissolution and mechanical erosion. The results of long-term temperature readings also revealed water column stratification within the cave, which was not disturbed by either tidal or wave action. The shallow, partly submerged and relatively small Y-Cave is characterised by a suite of complex environmental conditions, which, together with the resulting distribution of organisms, are unique to this cave.

  5. The relationship between caves minerals and hypogene speleogenesis along the Cerna Valley (SW Romania)

    Science.gov (United States)

    Onac, B. P.; Sumrall, J.; Tamas, T.; Povara, I.; Veres, D.; Darmiceanu, V.; Lascu, C.

    2009-04-01

    Over 100 caves are known to develop in the Jurassic and Cretaceous limestone that outcrops on both sides of the Cerna Valley in southwestern Romania. High temperature anomalies are rather uncommon in the cave environment; however, in certain caves in the lower part of Cerna Valley one can measure air temperatures as high as 40°C. This situation is due to the presence of thermal water pooling or flowing through the caves or to the hot steam that rises along fractures from deeper thermal water pools. During the long evolution of the thermo-mineral activity along the Cerna Valley interaction has occurred on a wide scale between the cave host rock or/and cave sediments and the ascending hot steam or/and thermal solutions of all types (mainly sulfide-rich). The present work documents the products of these processes and record the occurrence of twenty-four secondary cave minerals (both of primarily or replacement origin) precipitated under particular cave environments. Among these, glauberite, apjonite, halotrichite, pickeringite, rapidcreekite, tamarugite, and darapskite are the most interesting. The mineral samples were investigated by means of X-ray diffraction, electron microprobe, Fourier-transformed infrared spectroscopy, and scanning electron microscope analyses with the scope of linking the cave minerals with possible hypogene speleogenetic processes. The isotopic measurements (δ34S) performed on sulfate speleothems contribute valuable information on both minerals and caves origin. Apart from two minerals (i.e., calcite and gypsum), which were identified in every cave investigated so far, all the others fall into three distinct associations that have resulted from specific reactions under highly particular settings in Diana (sulfate-dominated association), Adam (phosphate-dominated), and Great Sălitrari (sulfate/phosphate/nitrate-rich association) caves. These three remarkable cave occurrences are presented along with morphological features that confirm the

  6. Diffusional limitations explain the lower photosynthetic capacity of ferns as compared with angiosperms in a common garden study.

    Science.gov (United States)

    Carriquí, M; Cabrera, H M; Conesa, M À; Coopman, R E; Douthe, C; Gago, J; Gallé, A; Galmés, J; Ribas-Carbo, M; Tomás, M; Flexas, J

    2015-03-01

    Ferns are thought to have lower photosynthetic rates than angiosperms and they lack fine stomatal regulation. However, no study has directly compared photosynthesis in plants of both groups grown under optimal conditions in a common environment. We present a common garden comparison of seven angiosperms and seven ferns paired by habitat preference, with the aims of (1) confirming that ferns do have lower photosynthesis capacity than angiosperms and quantifying these differences; (2) determining the importance of diffusional versus biochemical limitations; and (3) analysing the potential implication of leaf anatomical traits in setting the photosynthesis capacity in both groups. On average, the photosynthetic rate of ferns was about half that of angiosperms, and they exhibited lower stomatal and mesophyll conductance to CO2 (gm ), maximum velocity of carboxylation and electron transport rate. A quantitative limitation analysis revealed that stomatal and mesophyll conductances were co-responsible for the lower photosynthesis of ferns as compared with angiosperms. However, gm alone was the most constraining factor for photosynthesis in ferns. Consistently, leaf anatomy showed important differences between angiosperms and ferns, especially in cell wall thickness and the surface of chloroplasts exposed to intercellular air spaces.

  7. Effects of Flavonoids Extracted from Sweet Fern and Bitter Fern on DPPH Elimination%食用甜蕨及苦蕨黄酮类化合物对DPPH自由基的清除效果

    Institute of Scientific and Technical Information of China (English)

    方玉梅; 谭萍; 王毅红; 张春生

    2012-01-01

    为了弄清食用甜蕨和苦蕨黄酮提取物的抗氧化特性,以VE为对照,采用分光光度法等方法,研究了食用甜蕨和苦蕨黄酮类化合物对DPPH自由基清除率的影响.结果表明;在510nm下,甜蕨和苦蕨黄酮提取液的含量分别为843.59μg/g和614.15μg/g;甜蕨和苦蕨黄酮提取物对DPPH均有较好的清除效果,苦蕨与甜蕨黄酮提取物浓度为12.283μg/mL时,对DPPH的清除率分别为87,13%和50.21%,苦蕨黄酮提取液的抗氧化能力显著高于甜蕨,但二者的抗氧化能力均显著高于VE.%In order to ascertain the antioxidant properties of flavonoids extracted from sweet fern and bitter fern, the elimination rate on DPPH radical was studied taking VE as the control using spectrophotometric and other methods. The results showed that at 510 nm, the content of flavonoids extract of sweet fern and bitter fern was 843. 59 μg/g and 614. 15 μg/g respectively. The extraction of the flavonoids from sweet fern and bitter fern on DPPH elimination had The better effect. The flavonoids extracted from the sweet fern and bitter fern on DPPH elimination rate was 50. 21% and 87. 13% separately when the flavonoids concentration was 12. 283 μg/mL. The antioxidant capacity of the bitter fern flavonoids was significantly higher than that of the sweet fern flavonoids, but the antioxidant capacity of the sweet fern and bitter fern were significantly higher than VE.

  8. Seed ferns survived the end-Cretaceous mass extinction in Tasmania.

    Science.gov (United States)

    McLoughlin, Stephen; Carpenter, Raymond J; Jordan, Gregory J; Hill, Robert S

    2008-04-01

    Seed ferns, dominant elements of the vegetation in many parts of the world from the Triassic to Cretaceous, were considered to have disappeared at the end of the Cretaceous together with several other groups that had occupied key positions in terrestrial and marine ecosystems such as dinosaurs, plesiosaurs, and ammonoids. Seed-fern demise is generally correlated with competition from diversifying flowering plants through the Cretaceous and the global environmental crisis related to the Chicxulub impact event in the paleotropics at the end of the period. New fossils from Tasmania show that one seed-fern lineage survived into the Cenozoic by at least 13 million years. These fossils are described here as a new species, Komlopteris cenozoicus. Komlopteris is a genus of seed ferns attributed to Corystospermaceae and until now was not known from sediments younger than the Early Cretaceous. Discovery of this "Lazarus taxon," together with the presence of a range of other relictual fossil and extant organisms in Tasmania, other southern Gondwanan provinces, and some regions of northern North America and Asia, underscores high-latitude regions as biodiversity refugia during global environmental crises and highlights their importance as sources of postextinction radiations.

  9. The Lindsaeoid ferns of the Old World V. The smaller Pacific islands

    NARCIS (Netherlands)

    Kramer, K.U.

    1970-01-01

    The present paper is the third regional revision of the Old World Lindsaeoid ferns. The second (the fourth in the entire series on the Old World Lindsaeoids) will be published as vol. II, 1 part 3 of Flora Malesiana; it is awaiting publication as the present paper goes to the press. Species fully de

  10. A review of the fern genus Hypolepis (Dennstardtiaceae) in the Malesian and Pacific regions

    NARCIS (Netherlands)

    Brownsey, P.J.

    1987-01-01

    Fourteen species and one subspecies of the fern genus Hypolepis Bernh. are recognised in the Malesian and Pacific regions, excluding Australia and New Zealand. Three species, H. hawaiiensis, H. malesiana and H. scabristipes, and one subspecies, H. elegans subsp. carolinensis, are described for the f

  11. Cyathea nilgirensis Holttum (Cyatheaceae: Pteridophyta: a threatened tree fern from central Western Ghats, India

    Directory of Open Access Journals (Sweden)

    S.N. Dudani

    2014-01-01

    Full Text Available While studying some of the exclusive and threatened swamps overgrown with wild nutmeg trees (Myristica swamps, in the Kathalekan forest of Uttara Kannada in central Western Ghats, Cyathea nilgirensis Holttum, a southern Indian endemic tree fern was seen growing in the deep shade of the swampy forest. This is a new report of its distribution anywhere from north of Western Ghats.

  12. Reconciling extreme branch length differences: decoupling time and rate through the evolutionary history of filmy ferns.

    Science.gov (United States)

    Schuettpelz, Eric; Pryer, Kathleen M

    2006-06-01

    The rate of molecular evolution is not constant across the Tree of Life. Characterizing rate discrepancies and evaluating the relative roles of time and rate along branches through the past are both critical to a full understanding of evolutionary history. In this study, we explore the interactions of time and rate in filmy ferns (Hymenophyllaceae), a lineage with extreme branch length differences between the two major clades. We test for the presence of significant rate discrepancies within and between these clades, and we separate time and rate across the filmy fern phylogeny to simultaneously yield an evolutionary time scale of filmy fern diversification and reconstructions of ancestral rates of molecular evolution. Our results indicate that the branch length disparity observed between the major lineages of filmy ferns is indeed due to a significant difference in molecular evolutionary rate. The estimation of divergence times reveals that the timing of crown group diversification was not concurrent for the two lineages, and the reconstruction of ancestral rates of molecular evolution points to a substantial rate deceleration in one of the clades. Further analysis suggests that this may be due to a genome-wide deceleration in the rate of nucleotide substitution.

  13. Rhizosphere and non-rhizosphere mycoflora of two ferns from Panhala Fort, Kolhapur, Maharashtra, India

    Directory of Open Access Journals (Sweden)

    P. R. Hande

    2016-03-01

    Full Text Available Hypodematium crenatum (Forssk. Kuhn and Anogramma leptophylla (L. Link are threatened fern species from Western Ghats.  The present paper endorses the preliminary study on mycoflora associated with these ferns.  Eighteen fungal species have been isolated from rhizosphere and non-rhizosphere soils of selected ferns.  More diversity of fungi was observed in non-rhizosphere as compared to rhizosphere soils of both the ferns.  Aspergillus was found to be the most dominant genus among the population followed by Penicillium.  Higher percentage of fungal species is shown by H. crenatum, i.e., 44.5% in non-rhizosphere and 27.77% in rhizosphere; while a lower percentage of fungal species was found in A. leptophylla, i.e., 38.88% in non-rhizosphere and 16.66% in rhizosphere.  Number of colony forming units per gram soil was more in non-rhizosphere of A. leptophylla while it was less in non-rhizosphere of H. crenatum.  Inhibitory rhizosphere effect was exerted by A. leptophylla while H. crenatum has stimulatory effect on soil fungi. 

  14. Qasimia gen. nov., an early Marattia-like fern from the Permian of Saudi Arabia

    NARCIS (Netherlands)

    Hill, C.R.; Wagner, R.H.; El-Khayal, A. A.

    1985-01-01

    The marattialean fern Qasimia schyfsmae (Lemoigne) gen. et comb. nov. is described from the Late Permian plant bed at Unayzah in central Saudi Arabia. Although no organic matter is preserved, impregnation of the compressions by iron minerals at an early stage of diagenesis has partly mineralised the

  15. Burmese amber fossils bridge the gap in the Cretaceous record of polypod ferns

    OpenAIRE

    Schmidt, AR; Heinrichs, J.; Schneider, Harald

    2016-01-01

    publisher: Elsevier articletitle: Burmese amber fossils bridge the gap in the Cretaceous record of polypod ferns journaltitle: Perspectives in Plant Ecology, Evolution and Systematics articlelink: http://dx.doi.org/10.1016/j.ppees.2016.01.003 content_type: article copyright: Copyright © 2016 Elsevier GmbH. All rights reserved.

  16. Notes on the scholarly trajectory of Mª. Dolores Fernández-Posse

    Directory of Open Access Journals (Sweden)

    Gilman, Antonio

    2007-12-01

    Full Text Available The scholarly trajectory of Mª Dolores Fernández- Posse involved an ongoing process of critical observation, reflection, and change that is quite rare in Archaeology. Her change from normativism to a historically informed functionalism is representative of the general evolution of Spanish archaeological studies over the course of the past thirty years. What is unusual about Fernández-Posse -and attests to her straightforward and unassuming intelligence- is that she herself changed her mind and voiced that change with clarity and humor.

    La trayectoria científica de Mª Dolores Fernández-Posse se caracterizó por un proceso continuo de observación crítica, reflexión y cambio, algo poco común en Arqueología. Su cambio del normativismo a un funcionalismo de orientación histórica es representativo de la evolución de los estudios arqueológicos en España a lo largo de los últimos treinta años. Lo realmente inusual de Fernández-Posse -y lo que atestigua su directa pero no pretenciosa inteligencia- es que ella misma cambió de ideas y publicitó ese cambio con claridad y humor.

  17. A review of the fern genus Hypolepis (Dennstardtiaceae) in the Malesian and Pacific regions

    NARCIS (Netherlands)

    Brownsey, P.J.

    1987-01-01

    Fourteen species and one subspecies of the fern genus Hypolepis Bernh. are recognised in the Malesian and Pacific regions, excluding Australia and New Zealand. Three species, H. hawaiiensis, H. malesiana and H. scabristipes, and one subspecies, H. elegans subsp. carolinensis, are described for the f

  18. A Cognitive Reading Guide: Equalizing Instruction for "Where the Red Fern Grows."

    Science.gov (United States)

    Giannuzzi, Michelle L.; Hudson, Floyd

    1998-01-01

    Provides a cognitive reading guide for the first four chapters of the novel, "Where the Red Fern Grows" (Rawls, 1961), that incorporates teacher-directed whole-class instruction with a student reading guide to equalize instruction for various levels of learners. Ideas for whole-class instruction are contained within the lesson plans. (CR)

  19. Ever since Klekowski: testing a set of radical hypotheses revives the genetics of ferns and lycophytes.

    Science.gov (United States)

    Haufler, Christopher H

    2014-12-01

    There have been three periods of significant discovery in the exploration of fern and lycophyte genetics. First, during the 1930s, Andersson-Kottö conducted crossing studies on ferns. The publication of Manton's magnum opus on fern chromosomes in 1950 stimulated the second. The third emerged from Klekowski's 1973 American Journal of Botany publication that posed hypotheses linking breeding system dynamics and polyploid genetic architecture. Although Klekowski's assertions (predominant inbreeding and active polyploid genomes) were not supported, his hypotheses served as the impetus for improving our knowledge of the evolutionary mechanisms of ferns and lycophytes. It is now understood that (1) homosporous vascular plants are genetically diploid at high chromosome numbers and (2) both heterosporous and homosporous plants store and release genetic variation through a similar range of breeding systems. However, the seeming paradox of diploid genetic expression in homosporous vascular plants with high chromosome numbers remains unresolved. Ongoing and future research should include (1) more studies of gametophyte biology to elucidate the range and frequency of different breeding systems; (2) genomic analyses and new research on the mechanisms controlling bivalent formation to help discover how and why homosporous plant chromosomes appear so structurally stable; (3) considering whether the frequency of allopolyploidy in lineages can help explain why some are highly polyploid; and (4) chromosome painting studies to identify the dynamics of chromosome behavior in homosporous vascular plants. These open questions and continuing investigations demonstrate the longstanding impact of Klekowski's stimulating contribution.

  20. Alsophila weidenbrueckii (Cyatheaceae), a new scaly tree fern from Papua New Guinea

    NARCIS (Netherlands)

    Lehnert, M.

    2016-01-01

    The scaly tree fern Alsophila weidenbrueckii is described and illustrated as new to science. It occurs in the Bismarck range in north-eastern New Guinea at 1200–2100 m in evergreen wet mountain forest. The species reaches maturity at a comparatively old age and large size and regenerates only in int

  1. Interannual variation and host affiliations of endophytic fungi associated with ferns at La Selva, Costa Rica.

    Science.gov (United States)

    Del Olmo-Ruiz, Mariana; Arnold, A Elizabeth

    2014-01-01

    Ferns are an ancient and diverse lineage of vascular plants that differ morphologically, chemically and in growth habits from the angiosperms with which they co-occur. We used a culture-based approach coupled with phylogenetic analyses to characterize the incidence, diversity and composition of fungal endophyte assemblages in ferns, with a focus on healthy aboveground tissues of seven species of eupolypods at La Selva, Costa Rica. Endophytes were isolated from every individual plant and were similarly abundant and diverse in frond blades and stalks, in different vegetation types, in epiphytic vs. terrestrial species, and between sampling years. However, abundance, diversity and community structure differed significantly among fern species, and composition differed markedly between sampling years. Phylogenetic classification using separate and combined datasets revealed that as for many Neotropical angiosperms, the majority (95%) of endophyte taxa were Ascomycota, with particular dominance by Sordariomycetes, Eurotiomycetes and Dothideomycetes. However, our data suggest higher phylogenetic richness and stronger host affinities in fern associated endophytes relative to those studied in angiosperms thus far.

  2. The invention of WUS-like stem cell-promoting functions in plants predates leptosporangiate ferns.

    Science.gov (United States)

    Nardmann, Judith; Werr, Wolfgang

    2012-01-01

    The growth of land plants depends on stem cell-containing meristems which show major differences in their architecture from basal to higher plant species. In Arabidopsis, the stem cell niches in the shoot and root meristems are promoted by WUSCHEL (WUS) and WOX5, respectively. Both genes are members of a non-ancestral clade of the WUS-related homeobox (WOX) gene family, which is absent in extant bryophytes and lycophytes. Our analyses of five fern species suggest that a single WUS orthologue was present in the last common ancestor (LCA) of leptosporangiate ferns and seed plants. In the extant fern Ceratopteris richardii, the WUS pro-orthologue marks the pluripotent cell fate of immediate descendants of the root apical initial, so-called merophytes, which undergo a series of stereotypic cell divisions and give rise to all cell types of the root except the root cap. The invention of a WUS-like function within the WOX gene family in an ancestor of leptosporangiate ferns and seed plants and its amplification and sub-functionalisation to different stem cell niches might relate to the success of seed plants, especially angiosperms.

  3. Effect of temperature on green spore longevity for the ferns Equisetum ramosissimum and Osmunda regalis

    Science.gov (United States)

    Some fern species produce chlorophyllic or green spores. Green spores lose viability quickly compared to nongreen spores, and so need specialized treatment for long term conservation in germplasm banks. Dry storage at different temperatures (25 ºC, 4 ºC, -25 ºC, -80 ºC and -196 ºC) was studied in ...

  4. Effects of arsenic on nitrogen metabolism in arsenic hyperaccumulator and non-hyperaccumulator ferns

    Science.gov (United States)

    This study investigated the effects of arsenic on the in vitro activities of the enzymes (nitrate reductase and nitrite reductase) involved in nitrate metabolism in the roots, rhizomes, and fronds of two four-month old fern plants, Pteris vittata, an arsenic-hyperaccumulator, and Pteris ensiformis, ...

  5. Report of work on ferns carried out at Bogor 1957-1958

    NARCIS (Netherlands)

    Holttum, R.E.

    1959-01-01

    I spent the period from Oct. 8, 1957, to March 27, 1958, at Bogor, Indonesia. During that period I worked regularly in the Herbarium Bogoriense. The main part of my work consisted of a complete rearrangement of the fern herbarium, which consists of some 20,000- 30,000 specimens.

  6. Real-Time RGB-D Camera Relocalization via Randomized Ferns for Keyframe Encoding.

    Science.gov (United States)

    Glocker, Ben; Shotton, Jamie; Criminisi, Antonio; Izadi, Shahram

    2015-05-01

    Recovery from tracking failure is essential in any simultaneous localization and tracking system. In this context, we explore an efficient keyframe-based relocalization method based on frame encoding using randomized ferns. The method enables automatic discovery of keyframes through online harvesting in tracking mode, and fast retrieval of pose candidates in the case when tracking is lost. Frame encoding is achieved by applying simple binary feature tests which are stored in the nodes of an ensemble of randomized ferns. The concatenation of small block codes generated by each fern yields a global compact representation of camera frames. Based on those representations we define the frame dissimilarity as the block-wise hamming distance (BlockHD). Dissimilarities between an incoming query frame and a large set of keyframes can be efficiently evaluated by simply traversing the nodes of the ferns and counting image co-occurrences in corresponding code tables. In tracking mode, those dissimilarities decide whether a frame/pose pair is considered as a novel keyframe. For tracking recovery, poses of the most similar keyframes are retrieved and used for reinitialization of the tracking algorithm. The integration of our relocalization method into a hand-held KinectFusion system allows seamless continuation of mapping even when tracking is frequently lost.

  7. Coeval Eocene blooms of the freshwater fern Azolla in and around Arctic and Nordic seas

    NARCIS (Netherlands)

    Barke, J.; Burgh, A.H.P. van der; Konijnenburg-van Cittert, J.H.A. van; Collinson, M.E.; Pearce, M.A.; Bujak, J.; Heilman-Clausen, C.; Lotter, A.F.; Speelman, E.N.; Kempen, M.M.L. van; Reichart, G.-J.; Brinkhuis, H.

    2012-01-01

    For a short time interval (c. 1.2 Myr) during the early middle Eocene (~ 49 Myr), the central Arctic Ocean was episodically densely covered by the freshwater fern Azolla, implying sustained freshening of surface waters. Coeval Azolla fossils in neighboring Nordic seas were thought to have been

  8. A review of the fern genus Hypolepis (Dennstardtiaceae) in the Malesian and Pacific regions

    NARCIS (Netherlands)

    Brownsey, P.J.

    1987-01-01

    Fourteen species and one subspecies of the fern genus Hypolepis Bernh. are recognised in the Malesian and Pacific regions, excluding Australia and New Zealand. Three species, H. hawaiiensis, H. malesiana and H. scabristipes, and one subspecies, H. elegans subsp. carolinensis, are described for the

  9. A fern AINTEGUMENTA gene mirrors BABY BOOM in promoting apogamy in Ceratopteris richardii.

    Science.gov (United States)

    Bui, Linh T; Pandzic, Dzevida; Youngstrom, Christopher E; Wallace, Simon; Irish, Erin E; Szövényi, Péter; Cheng, Chi-Lien

    2017-04-01

    Asexual reproduction is widespread in land plants, including ferns where 10% of all species are obligate asexuals. In these ferns, apogamous sporophytes are generated directly from gametophytes, bypassing fertilization. In the model fern Ceratopteris richardii, a sexual species, apogamy can be induced by culture on high sugar media. BABY BOOM (BBM) genes in angiosperms are known to promote somatic embryogenesis, which like apogamy produce sporophytes without fertilization. Here, a Brassica napus BBM (BnBBM) was used to investigate genetic similarity between apogamy in ferns and somatic embryogenesis in angiosperms. A C. richardii transcriptome was constructed from which one AINTEGUMENTA-LIKE unigene, CrANT, was identified. Whole mount in situ hybridization showed that CrANT is expressed in sperm and fertilized eggs. Phylogenetic analysis grouped CrANT with other non-seed-plant ANT genes to the euANT clade but in a branch separate from BBM genes. Overexpression of CrANT or BnBBM promotes apogamy in C. richardii without sugar supplement. CrANT knockdown gametophytes responded weakly to sugar for apogamy promotion. Theses results suggest some genetic conservation between apogamy and somatic embryogenesis and that such asexual reproduction may be ancient. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  10. Phytochemical studies on five medicinal ferns collected from Southern Western Ghats, Tamilnadu

    Institute of Scientific and Technical Information of China (English)

    A John De Britto; D Herin Sheeba Gracelin; P Benjamin Jeya Rathna Kumar

    2012-01-01

    Objective: To analyze the phytochemical constituents of five medicinal ferns Pteris biaurita (P. biaurita) L., Lygodium flexiuosam (L. flexiuosam) (L.) Sw., Hemionitis arifolia (H. arifolia) (Burm. f.) T. Moore, Actinopteris radiate (A. radiata) (J. Koenig ex Sw.) Link and Adiantum latifolium (A. latifolium) Lam. Methods: The shade dried and powdered fronds (50 g) were extracted successively with 250 mL of petroleum ether, benzene, chloroform, methanol and distilled water using a Soxhlet extractor for 8 h at a temperature of 50-60℃ (not exceeding the boiling point of the solvent). Phytochemical analysis of the extracts was carried out according to the standard procedures. Results: Among the twenty five tested extracts, twenty extracts showed the presence of flavonoids. Phenolic compounds are present in methanol extracts of all the ferns. Five extracts showed the presence of triterpinoids and catechins. Ten extracts showed the occurrence of sugars and reducing sugars. Fifteen extracts showed the presence of alkaloids. Tannins and saponins are present in eight extracts. Steroids occurred in all the twenty five extracts. Only three extracts showed the presence of anthroquinones and amino acids. Conclusions: From this investigation, it can be concluded that the selected five medicinal ferns contain more bioactive principles. These potential ferns could be used as bio control agnets.

  11. Community structure of ferns in riparian forest: evaluation in anthropization gradient

    Directory of Open Access Journals (Sweden)

    Ivanete Teresinha Mallmann

    2016-03-01

    Full Text Available Riparian forests are essential to the maintenance of biodiversity and foster the development of ferns that are indicators of environmental quality. However, these forests have been degraded due mainly to high population density, pattern of urban settlement and agricultural expansion in rural areas. This study evaluated the environmental quality of riparian vegetation of the Cadeia River in Southern Brazil, using phytosociological parameters of the understory’s fern community and a Rapid Assessment Protocol of Habitat Quality (RAPQH. One hundred and twenty plots of 25 m2 were equally distributed among three fragments (FI, FII, FIII. All species of herbaceous ferns were inventoried in each sample unit. We calculated parameters of density, frequency, relative dominance and importance value (IV of species for the analysis of community structure. The lowest species richness was recorded at FIII (seven species. The floristic composition is more heterogeneous and richness is higher in FI, where the parcels had greater plant cover and RAPQH scores. The RAPQH score decreased with increasing degree of urbanization in the surrounding matrix and FI and FII were classified as “natural,” while FIII was classified as “impacted.” Considering the four species with the highest IV in the three fragments (totaling 69.11% of IV in the FI, 78.36% and 91.06% in FII and FIII respectively, it can be affirmed that the fern community structure is degraded with increasing anthropization.

  12. The Lindsaeoid ferns of the Old World V. The smaller Pacific islands

    NARCIS (Netherlands)

    Kramer, K.U.

    1970-01-01

    The present paper is the third regional revision of the Old World Lindsaeoid ferns. The second (the fourth in the entire series on the Old World Lindsaeoids) will be published as vol. II, 1 part 3 of Flora Malesiana; it is awaiting publication as the present paper goes to the press. Species fully

  13. SEM Studies on Vessels in Ferns. XV. Selected Rosette Epiphytes (Aspleniaceae, Elaphoglossaceae, Vittariaceae).

    Science.gov (United States)

    Schneider; Carlquist

    1999-09-01

    Tracheary elements from macerations of roots and rhizomes of Asplenium nidus, Elaphoglossum hirtum, and Vittaria lineata were studied by means of SEM. All of these have perforation plates in tracheary elements of both roots and rhizomes. The perforation plates in roots and rhizomes show greatest development of perforations (perforations a little wider than pits of tracheary elements) in E. hirtum roots and rhizomes and least in V. lineata roots and in rhizomes of A. nidus (porose pit membranes in many perforations). The secondary wall framework of perforation plates is little different from that of pitted wall areas in these three species. These rosette epiphytes have a lower degree of specialization of perforation plates that might accommodate rapid flow related to moisture availability fluctuations in comparison to perforation plates in vessels of rhizomatous epiphytic ferns. Generalizations are not warranted at this point, however. Rows of cushion-like structures occur adjacent to angles of the tracheary elements of E. hirtum. This is the first report of these in leptosporangiate ferns; they are known thus far only in a eusporangiate fern, Danaea elliptica (Marattiaceae). Raised frames of wall material around perforations are newly reported for tracheary elements of ferns in E. hirtum.

  14. A post-wildfire response in cave dripwater chemistry

    Science.gov (United States)

    Nagra, Gurinder; Treble, Pauline C.; Andersen, Martin S.; Fairchild, Ian J.; Coleborn, Katie; Baker, Andy

    2016-07-01

    Surface disturbances above a cave have the potential to impact cave dripwater discharge, isotopic composition and solute concentrations, which may subsequently be recorded in the stalagmites forming from these dripwaters. One such disturbance is wildfire; however, the effects of wildfire on cave chemistry and hydrology remains poorly understood. Using dripwater data monitored at two sites in a shallow cave, beneath a forest, in southwest Australia, we provide one of the first cave monitoring studies conducted in a post-fire regime, which seeks to identify the effects of wildfire and post-fire vegetation dynamics on dripwater δ18O composition and solute concentrations. We compare our post-wildfire δ18O data with predicted dripwater δ18O using a forward model based on measured hydro-climatic influences alone. This helps to delineate hydro-climatic and fire-related influences on δ18O. Further we also compare our data with both data from Golgotha Cave - which is in a similar environment but was not influenced by this particular fire - as well as regional groundwater chemistry, in an attempt to determine the extent to which wildfire affects dripwater chemistry. We find in our forested shallow cave that δ18O is higher after the fire relative to modelled δ18O. We attribute this to increased evaporation due to reduced albedo and canopy cover. The solute response post-fire varied between the two drip sites: at Site 1a, which had a large tree above it that was lost in the fire, we see a response reflecting both a reduction in tree water use and a removal of nutrients (Cl, Mg, Sr, and Ca) from the surface and subsurface. Solutes such as SO4 and K maintain high concentrations, due to the abundance of above-ground ash. At Site 2a, which was covered by lower-middle storey vegetation, we see a solute response reflecting evaporative concentration of all studied ions (Cl, Ca, Mg, Sr, SO4, and K) similar to the trend in δ18O for this drip site. We open a new avenue for

  15. Palaeoclimate Research in Villars Cave (Dordogne, SW-France

    Directory of Open Access Journals (Sweden)

    Genty Dominique

    2008-10-01

    Full Text Available Villars Cave is a typical shallow cave from South-West France (45.44°N; 0.78°E; 175 m asl that has provided several speleothempalaeoclimatic records such as the millennial scale variability of the Last Glacial period and the Last Deglaciation. Monitoring theVillars cave environment over a 13-year period has helped in the understanding of the stable isotopic speleothem content and inthe hydrology. For example, it was demonstrated that most of the calcite CaCO3 carbon comes from the soil CO2, which explainsthe sensitivity of the δ13C to any vegetation and climatic changes. Drip rate monitoring, carried out under four stalactites from thelower and upper galleries, has shown a well marked seasonality of the seepage water with high flow rates during winter and spring.A time delay of about two months is observed between the water excess (estimated from outside meteorological stations and thedrip rate in the cave. A great heterogeneity in the flow rate amplitude variations and in the annual quantity of water between twonearby stalactites is observed, confirming the complexity of the micro-fissure network system in the unsaturated zone. At a dailyscale, the air pressure and drip rates are anti-correlated probably because of pressure stress on the fissure network. Cave air CO2concentration follows soil CO2 production and is correlated with its δ13C content. Since the beginning of the monitoring, the cave airtemperature, in both lower and upper galleries, displays a warming trend of ~+0.4°C±0.1/10yrs. This might be the consequence ofthe outside temperature increase that reaches the Villars Cave galleries through thermal wave conduction. Chemistry monitoringover a few years has shown that the seepage water of the lower gallery stations is significantly more concentrated in trace and minorelements (i.e. Sr, Mg, Ba, U than the upper stations, probably due to the 10-20 m depth difference between these galleries, whichimplies a different seepage pathway

  16. rbcL and matK earn two thumbs up as the core DNA barcode for ferns.

    Directory of Open Access Journals (Sweden)

    Fay-Wei Li

    Full Text Available BACKGROUND: DNA barcoding will revolutionize our understanding of fern ecology, most especially because the accurate identification of the independent but cryptic gametophyte phase of the fern's life history--an endeavor previously impossible--will finally be feasible. In this study, we assess the discriminatory power of the core plant DNA barcode (rbcL and matK, as well as alternatively proposed fern barcodes (trnH-psbA and trnL-F, across all major fern lineages. We also present plastid barcode data for two genera in the hyperdiverse polypod clade--Deparia (Woodsiaceae and the Cheilanthes marginata group (currently being segregated as a new genus of Pteridaceae--to further evaluate the resolving power of these loci. PRINCIPAL FINDINGS: Our results clearly demonstrate the value of matK data, previously unavailable in ferns because of difficulties in amplification due to a major rearrangement of the plastid genome. With its high sequence variation, matK complements rbcL to provide a two-locus barcode with strong resolving power. With sequence variation comparable to matK, trnL-F appears to be a suitable alternative barcode region in ferns, and perhaps should be added to the core barcode region if universal primer development for matK fails. In contrast, trnH-psbA shows dramatically reduced sequence variation for the majority of ferns. This is likely due to the translocation of this segment of the plastid genome into the inverted repeat regions, which are known to have a highly constrained substitution rate. CONCLUSIONS: Our study provides the first endorsement of the two-locus barcode (rbcL+matK in ferns, and favors trnL-F over trnH-psbA as a potential back-up locus. Future work should focus on gathering more fern matK sequence data to facilitate universal primer development.

  17. Mapping planetary caves with an autonomous, heterogeneous robot team

    Science.gov (United States)

    Husain, Ammar; Jones, Heather; Kannan, Balajee; Wong, Uland; Pimentel, Tiago; Tang, Sarah; Daftry, Shreyansh; Huber, Steven; Whittaker, William L.

    Caves on other planetary bodies offer sheltered habitat for future human explorers and numerous clues to a planet's past for scientists. While recent orbital imagery provides exciting new details about cave entrances on the Moon and Mars, the interiors of these caves are still unknown and not observable from orbit. Multi-robot teams offer unique solutions for exploration and modeling subsurface voids during precursor missions. Robot teams that are diverse in terms of size, mobility, sensing, and capability can provide great advantages, but this diversity, coupled with inherently distinct low-level behavior architectures, makes coordination a challenge. This paper presents a framework that consists of an autonomous frontier and capability-based task generator, a distributed market-based strategy for coordinating and allocating tasks to the different team members, and a communication paradigm for seamless interaction between the different robots in the system. Robots have different sensors, (in the representative robot team used for testing: 2D mapping sensors, 3D modeling sensors, or no exteroceptive sensors), and varying levels of mobility. Tasks are generated to explore, model, and take science samples. Based on an individual robot's capability and associated cost for executing a generated task, a robot is autonomously selected for task execution. The robots create coarse online maps and store collected data for high resolution offline modeling. The coordination approach has been field tested at a mock cave site with highly-unstructured natural terrain, as well as an outdoor patio area. Initial results are promising for applicability of the proposed multi-robot framework to exploration and modeling of planetary caves.

  18. Millennial Scale Cycles from Speleothems of the Gibraltar Caves

    Science.gov (United States)

    Boyd, Meighan; Mattey, Dave; Atkinson, Tim; Hoffmann, Dirk

    2016-04-01

    The Rock of Gibraltar contains many solution caves which initially formed near sea level and now span elevations to over 300m as a result of slow uplift over time. In the modern climate, Gibraltar holds an important position near the southern limit of the tracks taken by the depressions that deliver rainfall to Europe from the North Atlantic sector of the atmosphere. Monitoring in St. Michaels and Ragged Staff caves has been carried out since 2004 by monthly sampling and deployment of logging instruments which reveals that speleothem growth is most strongly influenced by seasonally reversing cave ventilation that permeates the entire rock. The results provide unprecedented insight into how cave environments respond to seasonal change, variations in sea level and neotectonic uplift and the ways that regional climate is recorded as chemical proxies in an evolving cave environment. We present an overview of the results of this proxy record of precipitation, sea level and environmental change, including new analysis within this 500ka record. A general mean isotopic composition of 1ka time slices have been stacked into a preliminary record from over twenty speleothems. Within this we look at higher resolution time slices to examine the occurrence of millennial scale cycles which occur within the Gibraltar record. During glacial maxima, the Gibraltar record shows elevated δ18O and associated higher δ13C caused by greater degassing or lower soil pCO2 from weakened vegetative activity during cool arid glacials. Highly resolved millennial scale warming events which seem to match the Greenland ice core record give insights into SST changes and atmospheric reorganization at Gibraltar.

  19. Reproductive Seasonality in Nesticus (Araneae: Nesticidae) Cave Spiders.

    Science.gov (United States)

    Carver, Linnea M; Perlaky, Patricia; Cressler, Alan; Zigler, Kirk S

    2016-01-01

    Spiders of the family Nesticidae are members of cave communities around the world with cave-obligate (troglobiotic) species known from North America, Europe, Asia and the Indo-Pacific. A radiation of Nesticus (Araneae: Nesticidae) in the southern Appalachians includes ten troglobiotic species. Many of these species are of conservation interest due to their small ranges, with four species being single-cave endemics. Despite conservation concerns and their important role as predators in cave communities, we know little about reproduction and feeding in this group. We addressed this knowledge gap by examining populations of two species on a monthly basis for one year. We made further observations on several other species and populations, totaling 671 individual spider observations. This more than doubled the reported observations of reproduction and feeding in troglobiotic Nesticus. Female Nesticus carry egg sacs, facilitating the determination of the timing and frequency of reproduction. We found that Nesticus exhibit reproductive seasonality. Females carried egg sacs from May through October, with a peak in frequency in June. These spiders were rarely observed with prey; only 3.3% (22/671) of individuals were observed with prey items. The frequency at which prey items were observed did not vary by season. Common prey items were flies, beetles and millipedes. Troglobiotic species constituted approximately half of all prey items observed. This result represents a greater proportion of troglobiotic prey than has been reported for various troglophilic spiders. Although our findings shed light on the life history of troglobiotic Nesticus and on their role in cave ecosystems, further work is necessary to support effective conservation planning for many of these rare species.

  20. Ridge-forming, ice-bounded lava flows at Mount Rainier, Washington

    Science.gov (United States)

    Lescinsky, D. T.; Sisson, T. W.

    1998-04-01

    Large (0.3 4 km3) andesite and dacite lava flows at Mount Rainier, Washington, sit atop or are perched along the sides of high ridges separating deep valleys. Early researchers proposed that these ridge-forming lavas flowed into paleovalleys and displaced rivers to their margins; entrenchment of the rivers then left the lavas atop ridges. On the basis of exceptional flow thickness, ice-contact features, and eruption age measurements, we propose that the lavas flowed beside and between valley glaciers that filled the adjacent valleys in the Pleistocene. When the glaciers retreated, the flows were left high on the adjacent ridges. These lavas were never situated at valley floors and do not represent products of reversed topography. Instead, ridge-forming and perched lava flows at Mount Rainier and at many other high stratovolcanoes illustrate the ability of ice to dam, deflect, and confine flowing lava.