Spiral Tunnel Research Articles

Microbial proliferation coinciding with volcanism during the Permian–Triassic transition: New, direct evidence from volcanic ashes, South China

Coupling with major biotic extinction, both widespread microbially mediated deposits and ash beds characterize the Permian–Triassic boundary (PTB) successions worldwide. Thus, active volcanism through the PTB interval has been proposed to account for contemporary microbial bloom. Direct evidence, however, has long been scarce. Here we present several lines of evidence for microbial proliferation in the PTB ashes from South China. Petrographic analysis reveals annular, granular and tubular bioalteration textures that formed during microbial dissolution of glass and subsequent precipitation. Annular textures appear as fresh glass shards connected with bands in different thicknesses, showing rough and sharp interfaces, and are bordered with fibrous textures. Granular textures are composed of clusters of near-spherical bodies, ranging in size from 0.05 to 2μm. Tubular textures occur as straight, curved or spiral tunnels excavating into fresh glass. Their distinctive morphologies, microbe-analogous sizes, and log-normal size distributions all indicate a biogenic origin. Element mapping along alteration fronts shows enrichment of organic carbon and depletion in metabolically significant elements, providing further support for their biogenicity. Besides, textural relationships, low N, K and high C contents, as well as pronounced microstructure density variations between different ash beds in same section all suggest that the bioalteration textures are syngenetic with volcanic glass, relevant to microfossils rather than recent microbes. We interpret the fossilized organic remains (e.g. small coccoid-like spheroids, rods, filaments, and thin-films) as extracellular polymeric substances (EPS) probably produced by microorganisms, which might have served as templates for nucleation, and played a crucial role in bio-mineralization process. The diversity of microstructure sizes, shapes and organic remains may reflect a complex community of microbes in the PTB ashes. We infer that microbial proliferation may contribute to negative C-isotope excursions in the PTB ashes. Microbial blooms in ash beds directly triggered by large-scale volcanism may reveal that extreme environmental stresses prevailed during the PTB crisis.

Nuptse & Lhotse Go to the Rockies by J. Asnong

Asnong, Jocey. Nuptse & Lhotse Go to the Rockies. Victoria, BC: Rocky Mountain Books, 2014. Print.Nuptse & Lhotse are sibling cats with a sense of adventure. Finding inspiration in the Canadian Rockies, author and illustrator Jocey Asnong sends the cats on an adventure through the Canadian Rockies to help Mrs. Jasper find her missing cubs, Yoho and Kootenay. The cats along with Mrs. Jasper travel through the scenic highlights of Mountain Parks, from the Valley of the Ten Peaks to Lake Louise, along the Canadian Pacific Railway tracks to the Spiral Tunnels and up to the Columbia Icefields, with a stop to ski along the way.The story is straightforward, with simple language that works for beginner readers or reading aloud. A map at the beginning situates the events of the story, a comparison of a teddy bear to a grizzly bear is lighthearted and informative, and a maze illustration works with the plot of finding the lost cubs and is a fun activity while reading. It is the illustrations that bring the story to life by combining pencil crayon drawings with collage to create a layered visual experience leaving something new to be discovered with each read. Seamlessly incorporated into the text and illustrations are aspects of mountain geography and culture. This includes an explanation of the blue-green colour of the mountain lakes that is part of the cats’ stop in Lake Louise and homage to legendary mountain photographer Byron Harmon. These details make good entry points for further classroom learning and connect to a number of curriculum areas.The publisher, Rocky Mountain Books, is known for publications that celebrate mountain culture and Nuptse & Lhotse Go to the Rockies is an excellent addition to their growing catalogue for young readers. Highly recommended: 4 out of 4 starsReviewer: Lauren WheelerLauren Wheeler is a Program Lead at the Alberta Museums Association. When not assisting museums across Alberta, Lauren likes to explore and relax in her hometown of Canmore.

Research on the Safe Lighting of Minor Radius Curve Spiral Tunnels

Abstract: Based on the engineering background of Sichuan Ganhaizi spiral tunnel, this thesis studied the surrounding environment of portal and simulated the whole portal section, and then analyzed the effect of natural light on the portal illumination at different times. With the research on the brightness reduction and human eyes’ adaptation to it, the thesis calculated the discount rate k and obtained the requirements of vehicle speed at Ganhaizi tunnel entrance. Finally, the thesis put forward that some light reduction facilities such as vegetation outside the portal should be used, and on a clear day, from 12:00 to 15:00, the uphill tunnel portal illumination is significantly higher than other sections, thus at this time artificial lighting should be used to modulate entrance lighting.

COMPLEX TETRAPOD BURROWS FROM MIDDLE TRIASSIC RED BEDS OF THE ARGANA BASIN (WESTERN HIGH ATLAS, MOROCCO)

Although burrowing ability has been widespread in tetrapods for more than 300 million years, subsurface dwelling structures that indicate communal behavior are poorly evidenced from pre-Cenozoic strata. Here we present recently discovered tetrapod burrows from Middle Triassic red beds of the Argana Basin in central Morocco, whose complexity suggests an origin by gregarious animals. The well-preserved burrows occur in interbedded mudstones and sandstones interpreted as channel and overbank deposits of ephemeral, braided streams. All burrows originate from the top of thick-bedded sandstones and descend as moderately inclined (10°–30°), partially spiral tunnels to laterally extended, branched chambers in underlying mudstones. Tunnel segments are biconvex to planoconvex in cross section, up to 20 cm wide and 12 cm in maximum height and exhibit transverse scratch marks along the ceilings and sidewalls. Distinctive burrow characteristics include a laterally sinuous geometry (wavelength λ = 38–45 cm; amplitude A = 5–10 cm) of the tubelike passages and the presence of grouped alcoves in terminal chambers. We attribute the burrows to procolophonids or therapsids based on closely associated tetrapod tracks and the limited diameter of the excavations. Our findings represent the second oldest record of communal fossorial behavior by tetrapods and the oldest example from low-latitude areas. Beyond providing refuge from predators, these elaborate underground structures probably functioned as a buffer against diurnal or seasonal variations of air temperature and humidity in a semiarid habitat that was situated just north of the paleoequator.

On the Portal Construction Technology of Spiral Tunnel in Special Stratum

Abstract: Xigeda stratum is a kind of extremely soft rock with bad engineering property and its rock easily gets soft when wet which gives rise to geologic hazard, thus side and heading slope excavation at tunnel opening often causes collapses. Based on the construction technology of Gan Haizi tunnel in Yaxi express way, this thesis will first analyze its strata characteristics, and then focus on the methods of stabilizing side and heading slope, as well as the effective means to avoid opening deformation, so that the construction and operation can be carried out safely.

2A2-C28 トンネル構築式流体アクチュエータ

Rescue robots are expected to search for survivors trapped under the rubble by moving thorough narrow spaces. However, searching for the survivors under the rubble is a complex task. This paper proposes a new method to inspect narrow spaces by building a tunnel through the path. A tunnel is built by pulling out a belt from the inside of the tunnel, and it is combined with itself into a spiral form by the head unit. Fasteners are used to combine the belt with itself, and a pneumatic driving system called "Pinch Roller" is used for driving the fastener sliders. By this way, the authors have developed a prototype of Tunnel Building Robot and built a spiral tunnel with it.

1A2-G16 トンネル構築式移動探査ロボット : 第3報 : 探査機能の搭載

In most case rescue robots are expected to search survivors by moving over or through rubbishing environment. However, the inspection through the rubbish is a complex task, since the passage is narrow and rugged. This paper proposes a new method to aid the locomotion through narrow and rugged space by building a passageway. An inspector is inserted into the narrow space, and it builds a spiral tunnel, which enable carrying the necessary tube. The necessary mechanisms are analyzed for the constitution of a spiral tunnel. The authors have built a prototype of such inspector, and experiments showed the basic motion of the inspector building the spiral tunnel.

COMPARATIVE ANALYSIS OF BURROW SYSTEMS OF SEVEN SPECIES OF POCKET GOPHERS (RODENTIA: GEOMYIDAE)

Abstract Burrow systems of 43 individuals representing 7 species of pocket gophers (Geomyidae) in Texas (Geomys breviceps, G. bursarius, G. personatus, G. texensis, Thomomys bottae) and Jalisco, Mexico (Cratogeomys fumosus, Pappogeomys bulleri) were excavated, measured, described, and compared. All burrow systems consisted of a main tunnel with several to many side branches. Burrow systems of most species included chambers serving as nest sites, food caches, and latrines. Vertically oriented spiral tunnels are reported for the first time for G. breviceps, G. texensis, and C. fumosus. Regression analyses revealed that mean tunnel depths and diameters varied significantly by species in direct relation to body size. Mean length of tunnel systems varied significantly by species (longest in G. breviceps and shortest in T. bottae), but variation was not correlated with body size.

Rare helical spheroidal fossils from the Doushantuo Lagerstätte: Ediacaran animal embryos come of age?

A small quantity of helically coiled spheroidal fossils has been recovered from acid digestion of phosphorite samples from the Ediacaran Doushantuo Formation, South China. These fossils consist of an internal body enclosed in a sculptured envelope that is very similar to that of Doushantuo animal eggs and blastula embryos such as Megasphaera ornata . A hallmark of these fossils is a three-dimensional spiral structure, which always consists of three clockwise coils, and occurs on both the envelope and the internal body. The spiral structure consists of a spiral tunnel or canal flanked by two raised levees, and it is punctured by a series of holes. Some specimens show evidence of uncoiling, invagination along the spiral structure, or bipectinate furrowing on the band between canals. A possible ontogenetic link between these helical spheroidal fossils and Megasphaera ornata is suggested by similar size, similar envelope sculptures, and co-occurrence. We tentatively interpret these fossils as postblastula embryos related to Megasphaera ornata . Thus, they may represent the most advanced embryonic fossils so far known from the Ediacaran, although their adult morphologies and phylogenetic affinity remain unknown.

Metallic Choir

Metallic Choir Alta Ifland (bio) At the end of the end of the world the end of a metallic spiral can be seen, coming from nowhere and stopping for no particular reason at this precise spot. If one pulls the end of the spiral, it triggers a sound like that of a child's voice, singing on Sundays in a church choir. If one pulls twice, the sound of the spiral resembles that of the voice of two children. With some effort, the entire choir can be heard and the expressionless faces of children can be seen, all boys, whose voices soar together, breaking the air's purity. Their song, suspended for a moment in the air, and from there, coming back to earth, brings to mind a waterfall curtain. Through the water curtain the profile of a naked woman can be seen passing and disappearing, then coming back, and passing and disappearing. At the beginning, the woman's hair brings to mind water itself, then one notices that it is water itself. The children's voices speed up. The woman passing through the curtain moves faster and faster. She moves so fast that she seems to be spinning around herself, while the children's voices seem to be breaking into various elements that transform the song into a collage of disharmonious and disparate sounds. When the noise becomes unbearable, the children's voices will themselves have become a swarm of bees attacking their fragile bodies, which they will gradually strip of their flesh, leaving only the white bones. Then the bees will be swept into the spiral tunnel, exploring its inner walls until reaching its nowhere, while at twilight the bones will begin another song. Alta Ifland Alta Ifland is originally from Romania and currently lives in Northern California. Her work has appeared in Metamorphoses, FIELD, New Orleans Review, and Words without Borders. Copyright © 2005 the University of Nebraska Press

Immunoelectron microscopic localization of nitric oxide synthase III in the guinea pig organ of Corti.

Nitric oxide synthase III (NOS III) was identified in the guinea pig cochlea on an ultrastructural level using a post-embedding immunolabeling procedure. Ultrathin sections of London Resin (LR) White-embedded specimens were incubated with various concentrations of a commercially available antibody to NOS III and the immunoreactivity visualized by a gold-labeled secondary antibody. Analysis of ultrathin sections of the organ of Corti in the second turn of the cochlea showed that NOS III could be localized in the endothelial cells of the blood vessels under the basilar membrane, which was comparable to its location in similar cells types in various biological systems. Besides this, NOS III was also found in the cytoplasm and in the nuclei of inner and outer hair cells. Immunoreactivity was not distributed homogeneously within receptor cells. Numerous gold particles could be identified at the border of the cuticular plates, in the middle parts of the stereocilia and in the cytoplasm. Gold-labeled anti-NOS III antibodies in these sites were seen mostly on the cytoplasmic side of the submembranous cisterns in the vicinity of mitochondria and in the central parts of the hair cells, whereas the cisterns were nearly free from any immunoreactivity. NOS III was also detected in the efferent and afferent nerve endings that were located at the basal and basolateral side of the outer hair cells. Some immunoreactivity was visible in different nerve fibers of the inner and outer spiral tunnels. Besides this, gold-labeled antibodies were also present in the cuticular plate of inner and outer pillar cells, in the cytoskeletal elements located in the apical parts of Deiters cells, forming the lamina reticularis, and in the cytoskeletal-containing region of the cytoplasm of those Deiters cells located at the basal side of the outer hair cells. The role of the NOS III immunoreactivity identified in the organ of Corti was consistent with respect to hair cell and tissue modulation.

Spiral Tunneling Cracks Induced by Environmental Stress Cracking in LaRC™-TPI Adhesives

Abstract Some currently-available formulations of LaRC™-TPI, a thermoplastic polyimide originally developed at NASA-Langley, were found to be highly susceptible to environmental stress cracking when exposed to solvents such as acetone, toluene, diglyme and methyl ethyl ketone. The combination of stress and solvent led to rapid cracking in films and adhesive layers of this material system. Residual cool-down stresses induced when the LaRC-TPI is used as an adhesive or coating led, in the presence of a solvent, to dense “mud crack” patterns which relieve a portion of the stored energy. Because these through-the-thickness cracks are not able to relieve the stored energy in the vicinity of the adherends, additional fractures in the form of curious spiral tunnel cracks initiated and grew inward within each adhesive fragment. Micrographs of the spiral fractures are given, along with a qualitative explanation for the failure process as observed in adhesives and coatings.

Tidal/littoral offshore shelf deposits—Lower Cambrian Gog Group, southern Rocky Mountains, Canada

Nearly 600 m of shallow marine fine- to coarse-grained quartzites interbedded with shales of the Lower Cambrian Gog Group are exposed at the Spiral Tunnels section, Kicking Horse Pass, Yoho National Park. Facies are defined and interpreted on the basis of sedimentary structures as follows: (1) interbedded shale and sandstone-pelagic sediments with interbedded coarse-grained bottom current deposits; (2) massive to laminated shale-pelagic sediments; (3) conglomerate-storm deposits; (4) linsen-bedded sandstone in shale-bedload deposits with pelagic or suspended sediments; (5) planar tabular cross-bedded sandstone-small scale: bedload deposits from two-dimensional megaripples; large scale: sand wave or sand ridge deposits; (6) trough cross-bedded sandstone: three-dimensional ripple and megaripple deposits; (7) low-angle to horizontally stratified standstone-shoaling wave deposits; and (8) massive sandstone-well-sorted deposits. Large-scale (1–5 m thick) lateral accretion (epsilon) deposits also occur. Facies trends are interpreted as reflecting the migration and aggradation of offshore sand ridges. Larger sand ridge complexes are comprised of amalgamated individual sand ridge accumulations. Progradation of sand ridge complexes yield coarsening-upward sequences; whereas retreat of sand ridge complexes yield fining-upward trends. Overall the sequences are poorly defined-mainly a consequence of the interaction of sand ridge and inter-ridge swales. Theoretical considerations of the Early Cambrian configuration of continents, Earth-Moon separation, and paleoceanographic conditions suggest that storms were not that important in the emplacement of the sand ridge complexes. Major offshore current systems are interpreted as being tidally driven, with perhaps a secondary littoral or geostrophic current influence. The thick sequence of the section (> 500 m), along with a consistent trace fossil signature, suggests that the Gog Group was deposited under shallow marine offshore shelf settings of a rapidly subsiding passive continental margin. This is consistent with the geophysical model for the proto-Pacific margin-which during the Early Cambrian was characterized by very rapid thermal subsidence.

Spiral tunnel runs rings around arctic circle dam site : Martin, D Tunn TunnlgV16, N11, Nov 1984, P15–17

La construction d'une installation hydroelectrique souterraine de 150 MW comprend le percement de plus de 9 km de tunnel dans de la roche dure et un hall de machine de 100 m de long et 16 m de large. L'acces pour la construction du barrage dans une gorge etroite de la riviere Alta ne peut etre effectue que par helicoptere et par un tunnel en spirale de 1,2 km. Des installations speciales sont faites pour proteger les saumons

Aspartate aminotransferase immunoreactivity in cochlea of guinea pig

The distribution of aspartate aminotransferase-like immunoreactivity in the cochlea of the guinea pig was studied at the light microscopy level. Indirect immunofluorescence histochemistry using antisera against cytoplasmic aspartate aminotransferase prepared from pig heart was applied to surface preparations of the organ of Corti and cryostat sections of the cochlea. In the modiolus, immunofluorescence was localized to spiral ganglion cells and myelinated fibers of the auditory nerve and intraganglionic spiral bundles. In the organ of Corti, immunofluorescence was seen in upper tunnel crossing fibers and at the base of outer hair cells, following a distribution similar to that of the efferent innervation of the outer hair cells. Weak immunofluorescence was seen in the inner spiral bundle and tunnel spiral bundle, but was not present in all preparations. Immunofluorescence was not seen in inner hair cells, nor at the base of inner hair cells, and may have been absent from outer hair cells. It is concluded that spiral ganglion cells and myelinated auditory nerve axons contain aspartate aminotransferase-like immunoreactivity such immunoreactivity has previously been determined in auditory nerve endings inthe cochlear nucleus. Olivocochlear neurons that innervate outer hair cells also contain such immunoreactivity while other cochlear efferents contain little or none.

Catasthrophic glacial outburst flood (Jokulhlaup) mechanism for debris flow generation at the spiral tunnels, kicking horse river basin, British Columbia. Technical note : Jackson, L E Can Geotech J, V16, N4, Nov 1979, P806–813

Catasthrophic glacial outburst flood (Jokulhlaup) mechanism for debris flow generation at the spiral tunnels, kicking horse river basin, British Columbia. Technical note : Jackson, L E Can Geotech J, V16, N4, Nov 1979, P806–813

A catastrophic glacial outburst flood (jökulhlaup) mechanism for debris flow generation at the Spiral Tunnels, Kicking Horse River basin, British Columbia

Debris flows have blocked rail and highway routes in the upper Kicking Horse River valley, British Columbia, a number of times during this century. The origins of debris flows from the most troublesome tributary basin were investigated following the debris flows and floods of September 6, 1978. A jökulhlaup (catastrophic glacial outburst flood) origin was determined for the debris flows and flood of this event. An investigation of weather records prior to debris flows of 1962, 1946, and 1925 indicates a similar origin for the 1946 and 1925 events.

Cochlear Innervation In The Guinea Pig: II. The Spiral Tunnel Bundle

The organization of nerve fibers in the spiral tunnel bundle (STB) of the guinea pig organ of Corti has been studied by light and electron microscopy. In the basal turn STB fibers were found to run toward the base or apex in about equal numbers while in the upper turns they ran predominantly in an apical direction. Long spiral fascicles of 100 microns or more in length were abundant in the third and fourth turns, but were rarely seen in the lower turns. No synaptic contacts between tunnel bundle fibers could be found and no afferent nerve fibers were seen in the bundle. Furthermore, interruption of the efferent nerve supply resulted in complete degeneration of the STB. The tunnel bundle does not, therefore, appear to be a site of synaptic interaction between afferent and efferent neutral elements.

Degeneration and distribution of efferent nerve fibers in the guinea pig organ of corti. A light and scanning electron microscopic study

Summary After brain stem lesions interrupting the efferent innervation to the inner ear in guinea pigs, the degeneration and the distribution of efferent nerve fibers in the organ of Corti were studied in surface preparations stained by the zinc iodide-osmic acid (ZIO) technique. Light microscopy, transmission electron, and scanning electron microscopy were used to examine tissue from animals with postoperative survival times of 1–41 days. Following section of the crossed efferent bundle alone, degenerative changes were first evident in the outer hair cell (OHC) innervation as early as 1 day after placement of the brain stem lesion. Degeneration in the inner spiral (ISB) and spira l tunnel (STB) bundles was seen after about 3 days. After transection of both components of the efferent nerve supply all neural elements stained by the ZIO method degenerated and disappeared. This finding indicates a high specificity of the stain for the efferent nerve fibers. It was found that both radially and spirally oriented efferent fibers innervate the OHC. The spiral fibers follow long, complex courses directed toward either the base or the apex of Corti's organ. These fibers predominate in the upper cochlear turns where they sometimes meander into the region of Hensen's cells. Radial fibers comprise the major efferent supply to the OHC in the basal portion of the cochlea. Fibers coursing toward both the base and apex were seen in the inner spiral and spiral tunnel bundles. A close structural relationship was noted between these two bundles, suggesting that the STB may, in part, serve in an accessory capacity to the ISB. Single nerve fibers were often seen contacting the supranuclear portions of both inner and outer hair cells. These climbing efferent fibers were particularly numerous in the upper turns of the organ of Corti.

Miocene Trace Fossils from Borneo

In the Miocene Belait formation of northern Sarawak, Brunei and Sabah burrows ofOphiomorpha Lundgren were found, described here asOphiomorpha borneensis n. ichnosp. A few associated spiral tunnels of theXenohelix-type were also found. Two species ofHantzschelinia Vialov occurred on Labuan Island. A third type of structure was found in Brunei and it probably represents castings of an unknown lamellibranch. The burrows and castings were made in a brackish water environment, probably in the littoral zone of an embayment or delta.