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1
Wheatley, David, Winston Seiler, and Marjorie Chan. "The Wind-Swept Nautilus, Enigmatic Clastic Pipes, and Toadstool Landforms: Geologic Features of the Paria Plateau." Geosites 1 (December 31, 2019): 1–11. http://dx.doi.org/10.31711/geosites.v1i1.67.
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The Colorado Plateau occupies much of the southwestern United States including portions of Arizona, Colorado, Utah, and New Mexico. This region presents unobstructed views from mesa tops, beautifully colored soils, lone standing buttes, and canyons cut thousands of feet deep. The Colorado Plateau represents a well-preserved window into the Earth’s history. Today, the rocks of the Colorado Plateau lie roughly horizontally, as they were deposited hundreds of millions of years ago. The Plateau’s rise has motivated rivers, in their downhill progress, to carve innumerable canyons. These river canyons allow any nature-lover the opportunity to gaze at 100s of millions of years of geologic history. Within the larger Colorado Plateau, the Paria Plateau straddles the Utah and Arizona borders, and includes the Vermilion Cliff s National Monument, the Paria Canyon-Vermilion Cliffs Wilderness Area, and the southern extent of the Grand Staircase Escalante National Monument (GSENM; pre-2018 boundaries). The Paria Plateau is best known for spectacularly colored, wind-sculpted features such as Coyote Buttes and “The Wave,” where vivid colors accent cross-strata resembling a cresting ocean wave. The Plateau is also recognized for the geologically notable Vermilion Cliff s, Buckskin Gulch slot canyon, White Pocket area, and the Paria River Canyon. Although only two, dual-lane highways circumvent the plateau, several wash-boarded gravel and deeply mud-rutted roads allow access to its interior. From these dirt roads, a few sandy, four-wheel drive paths diminish as they extend and branch into the plateau’s interior. Overall, the Paria Plateau is a relatively quiet and little-visited wilderness.
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Plog, Stephen. "Exploring the Ubiquitous through the Unusual: Color Symbolism in Pueblo Black-on-White Pottery." American Antiquity 68, no. 4 (October 2003): 665–95. http://dx.doi.org/10.2307/3557067.
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One of the common design characteristics on black-on-white pottery from the eleventh and twelfth centuries in the northern American Southwest is the use of thin, parallel lines (hachure) to fill the interior of bands, triangles, or other forms. This essay explores a proposal offered by Jerry Brody that hachure was a symbol for the color blue-green. Brody's proposal is examined by exploring colors and color patterns used to decorate nonceramic material from the Chaco Canyon region of northwestern New Mexico. His proposal is supported and the implications of this conclusion for Chaco Canyon and for future studies of this nature are discussed.
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Huser, Verne. "Canyon Interludes: Between White Water and Red Rock by Paul W. Rea." Western American Literature 33, no. 3 (1998): 326–28. http://dx.doi.org/10.1353/wal.1998.0003.
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Zamparo, Joann M., Theodore G. Andreadis, Robert E. Shope, and Shirley J. Tirrell. "Serologic Evidence of Jamestown Canyon Virus Infection in White-Tailed Deer Populations from Connecticut." Journal of Wildlife Diseases 33, no. 3 (July 1997): 623–27. http://dx.doi.org/10.7589/0090-3558-33.3.623.
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Reneau, Steven L., and David P. Dethier. "Late Pleistocene landslide-dammed lakes along the Rio Grande, White Rock Canyon, New Mexico." Geological Society of America Bulletin 108, no. 11 (November 1996): 1492–507. http://dx.doi.org/10.1130/0016-7606(1996)108<1492:lpldla>2.3.co;2.
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Kiessling, Anders, Kerstin Lindahl-Kiessling, and Karl-Heinz Kiessling. "Energy utilization and metabolism in spawning migrating Early Stuart sockeye salmon (Oncorhynchus nerka): the migratory paradox." Canadian Journal of Fisheries and Aquatic Sciences 61, no. 3 (March 1, 2004): 452–65. http://dx.doi.org/10.1139/f04-006.
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Sockeye salmon (Oncorhynchus nerka) were followed during their 1400-km-long migration from cessation of feeding outside British Columbia, Canada, up the Fraser River to spawning. Enzymatic capacity (indicative of glycolysis, β-oxidation, and respiratory chain ATP formation), muscle fibre size distribution, body and muscle conformation, and gross chemical composition in different parts of red and white muscle were monitored to determine energy strategies throughout the migration. The mobilization of extramuscular lipid depots was also monitored. The most conspicuous change in white muscle, concomitant with a large decrease in protein content, was an ordered reduction in muscle fibre size and lipid depots with distance covered, resulting in an accumulation of fibres with a cross section between 2000 and 6000 µm2 and a maintained level of 4% intramuscular fat. A peak in oxidative capacity was noted in red muscle during the strenuous passage of Fraser Canyon. In white muscle, glycolytic capacity was maintained at least until passage of the Fraser Canyon. Enzymatic capacity was higher in the caudal than rostral part of the muscle. Differences were also found between lateral and dorsal parts of the white muscle, indicating significant differences in the timing and magnitude of enzymatic capacity of red and white muscle.
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Gowans, Shannon, and Hal Whitehead. "Distribution and habitat partitioning by small odontocetes in the Gully, a submarine canyon on the Scotian Shelf." Canadian Journal of Zoology 73, no. 9 (September 1, 1995): 1599–608. http://dx.doi.org/10.1139/z95-190.
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In this paper we examine the summer distribution of three species of small odontocetes in the highly productive waters in and near the Gully, a submarine canyon on the edge of the Scotian Shelf. Atlantic white-sided dolphins (Lagenorhynchus acutus) and common dolphins (Delphinus delphis) were not randomly distributed with respect to depth, sea-floor relief, month of sighting, or sea-surface temperature. Long-finned pilot whales (Globicephala melas) were not randomly distributed with respect to month or sea-surface temperature. These species used the Gully slightly differently, although there was overlap. White-sided dolphins were seen only in the core of the canyon, but were sighted at all temperatures, depths, and sea-floor reliefs and throughout the summer field season. Common dolphins had a modest range throughout the deeper waters and were not seen in the summer before July, when the water warms. Pilot whales ranged widely over the study area, preferring areas with fairly flat relief and were more common later in the summer, when the waters were warmer. It appears that white-sided and common dolphins partition the Gully temporally but not geographically.
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Bertolino, M., S. Ricci, S. Canese, A. Cau, G. Bavestrello, M. Pansini, and M. Bo. "Diversity of the sponge fauna associated with white coral banks from two Sardinian canyons (Mediterranean Sea)." Journal of the Marine Biological Association of the United Kingdom 99, no. 8 (November 12, 2019): 1735–51. http://dx.doi.org/10.1017/s0025315419000948.
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AbstractThe three-dimensional coral scaffolds formed by the skeletons of the cold-water corals Madrepora oculata and Lophelia pertusa represent an important deep-sea hard substratum and create an optimal shelter for a rich associated fauna in which the contribution of Porifera has still not been fully considered. The taxonomic analysis of sponges collected from two Sardinian canyons (Nora and Coda Cavallo, 256–408 m) and associated with the dead coral matrix resulted in 28 species, including new records for the Mediterranean Sea, Italian fauna or Central Tyrrhenian Sea. In addition, for many species this is the first finding associated with the coral framework or the first documentation of the in situ morphology. The taxonomic comparison with sponge assemblages associated with coral frameworks from Santa Maria di Leuca, Strait of Sicily and Bari Canyon, gave the opportunity to evaluate the similarities among geographically separated banks. Overall, the percentage of exclusive species (recorded only in one site), is very high (81%) and only one species is shared by all four sites, suggesting a low connectivity among the sponge communities. The percentage of shared species is higher for the Maltese community, supporting the role of the Sicily Channel as a crossroads between the communities of the eastern and western Mediterranean basins. Here, 55% of the sponges associated to the coral framework are also reported in shallow-water coralligenous assemblages, indicating a high bathymetric connectivity as well as an ecological plasticity allowing these species to occupy a wide range of small, dark refuges.
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Lloyd, K. J., and J. J. Eberle. "A late Eocene (Chadronian) mammalian fauna from the White River Formation in Kings Canyon, northern Colorado." Rocky Mountain Geology 47, no. 2 (September 1, 2012): 113–32. http://dx.doi.org/10.2113/gsrocky.47.2.113.
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Kanes, Kristen S., Stan E. Dosso, Tania L. Insua, and Xavier Mouy. "Temporal patterns in Pacific white-sided dolphin communication at Barkley Canyon, with implications for multiple populations." Journal of the Acoustical Society of America 144, no. 3 (September 2018): 1777. http://dx.doi.org/10.1121/1.5067858.
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Hagadorn, James W., and Ben Waggoner. "Ediacaran fossils from the southwestern Great Basin, United States." Journal of Paleontology 74, no. 2 (March 2000): 349–59. http://dx.doi.org/10.1017/s0022336000031553.
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Ediacaran fossils from the southwestern Great Basin may help constrain regional Vendian-Cambrian biostratigraphy and provide biogeographic links between facies in this region and elsewhere. Locally, trace fossils suggest the Vendian-Cambrian boundary occurs within or below the upper third of the lower member of the Wood Canyon Formation. Ediacaran soft-bodied and tubular fossils, including the frondlike fossil Swartpuntia and tubular, mineralized or agglutinated fossils similar to Archaeichnium Cloudina Corumbella, and Onuphionella occur in the lowermost Wood Canyon Formation. Discoidal forms referred to Nimbia occur in both the lowermost Wood Canyon Formation and the underlying strata of the Stirling Quartzite. These fossils occur directly below Lower Cambrian trace fossils, including Treptichnus pedum, and confirm the persistence of the Ediacaran biota to near the base of the Cambrian. These faunas may also help strengthen previously proposed correlation schemes between the two main facies belts of the southwestern Great Basin (the Death Valley and White-Inyo facies), because a nearly identical Vendian-lowest Cambrian succession of faunas occurs in both regions. Lastly, lack of cosmopolitan Ediacaran faunas in these strata suggests a paleobiogeographic link between the southwestern U.S. and southern Africa in Vendian time.
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Hagadorn, James W., Christopher M. Fedo, and Ben M. Waggoner. "Early Cambrian Ediacaran-type fossils from California." Journal of Paleontology 74, no. 4 (July 2000): 731–40. http://dx.doi.org/10.1017/s0022336000032832.
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Ediacara-type fossils are rare in the southwestern United States, and Cambrian occurrences of soft-bodied Ediacaran-type fossils are extremely rare. We report both discoidal and frondlike fossils comparable to Ediacaran taxa from the western edge of the Great Basin. We describe one specimen of a discoidal fossil, referred to the form species ?Tirasiana disciformis, from the upper member of the Lower Cambrian Wood Canyon Formation from the Salt Spring Hills, California. Two fragmentary specimens of frond-like soft-bodied fossils are described from the middle member of the Lower Cambrian Poleta Formation in the White Mountains, California, and the upper member of the Wood Canyon Formation in the southern Kelso Mountains, California. On the basis of similarities with fossils from the lower member of the Wood Canyon Formation and from the Spitzkopf Member of the Urusis Formation of Namibia, these specimens are interpreted as cf. Swartpuntia. All fossils were collected from strata containing diagnostic Early Cambrian body and trace fossils, and thus add to previous reports of complex Ediacaran forms in Cambrian marine environments. In this region, Swartpuntia persists through several hundred meters of section, spanning at least two trilobite zones.
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Murphy, S. K., and D. M. Rizzo. "First Report of Phytophthora ramorum on Canyon Live Oak in California." Plant Disease 87, no. 3 (March 2003): 315. http://dx.doi.org/10.1094/pdis.2003.87.3.315c.
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During August 2002, Phytophthora ramorum S. Werres & A.W.A.M. de Cock was isolated from branches <2.0 cm in diameter on a canyon live oak (Quercus chrysolepis) in Mt. Tamalpais State Park, Marin County, CA. The shrub was a cluster of stems <1 m in diameter and 1 m high. Similar cankers were observed on small branches of adjacent canyon live oaks and there was dieback of the branches distal to the lesions. Many tanoak (Lithocarpus densiflorus), California bay laurel (Umbellularia californica), and evergreen huckleberry (Vaccinium ovatum) were also infected by P. ramorum at this site. The isolate was identified as P. ramorum by its abundant chlamydospores and caducous, semi-papillate sporangia and internal transcribed spacer (ITS) rDNA sequences identical to those of isolates of P. ramorum from Quercus spp., tanoak, and Rhododendron (1,3). To test for pathogenicity, two greenhouse trials (5 seedlings per trial plus controls) were conducted on 20- to 24-month-old canyon live oak seedlings. Coast live oak (Q. agrifolia, section Lobatae) seedlings were included in the trials as a comparison because the species is known to be susceptible (1). Stems (approximately 1 cm in diameter) were wound inoculated (1). After 6 weeks, lesion lengths in the cambium of canyon live oak averaged 17.2 mm (range 16 to 30 mm), which was significantly greater (analysis of variance [ANOVA], P < 0.05) in both trials than those of control inoculations (mean = 6 mm). Coast live oak seedlings inoculated at the same time had mean lesion lengths of 22.6 mm (range 15 to 30 mm). P. ramorum was recovered from 100% of inoculated stems. Canyon live oak has a wide geographic range within California, but is not common in the areas currently affected by P. ramorum. We have not observed disease symptoms or unusual mortality on overstory canyon live oaks. Although a number of understory canyon live oaks at the site on Mt. Tamalpais were apparently infected, the long-term effect of P. ramorum infection on understory trees remains unclear. To our knowledge, this is the first report of infection by P. ramorum of an oak species outside of the section Lobatae (red oaks); canyon live oak is classified in the section Protobalanus (intermediate or golden cup oaks) (2). Oaks in the section Quercus (white oaks) have not been observed to be infected by P. ramorum in the field. References: (1) D. M. Rizzo et al. Plant Dis. 86:205, 2002. (2) P. Manos et al. Mol. Phylogenet. Evol. 12:333, 1999. (3) S. Werres et al. Mycol. Res. 105:1155, 2001.
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Boromisa, Robert D., and Paul R. Grimstad. "SEROCONVERSION RATES TO JAMESTOWN CANYON VIRUS AMONG SIX POPULATIONS OF WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS) IN INDIANA." Journal of Wildlife Diseases 23, no. 1 (January 1987): 23–33. http://dx.doi.org/10.7589/0090-3558-23.1.23.
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Olds, Travis A., Jakub Plášil, Anthony R. Kampf, Peter C. Burns, Barbara P. Nash, Joe Marty, Timothy P. Rose, and Shawn M. Carlson. "Redcanyonite, (NH4)2Mn[(UO2)4O4(SO4)2](H2O)4, a new zippeite-group mineral from the Blue Lizard mine, San Juan County, Utah, USA." Mineralogical Magazine 82, no. 6 (May 15, 2018): 1261–75. http://dx.doi.org/10.1180/minmag.2017.081.094.
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ABSTRACTRedcanyonite (IMA2016-082), (NH4)2Mn[(UO2)4O4(SO4)2](H2O)4, occurs underground in the Blue Lizard mine, Red Canyon, White Canyon district, San Juan County, Utah, USA. It occurs with natrozippeite, brochantite, devilline, posnjakite, johannite, gypsum, bobcookite, pickeringite, pentahydrite and the NH4-analogue of zippeite: ammoniozippeite. Redcanyonite occurs as radial aggregates of red–orange needles and blades individually reaching up to 0.2 mm long, with aggregates measuring up to 1 mm in diameter. Crystals are flattened on {010} and elongated along [100], exhibit perfect cleavage on {010}, and exhibit the forms {010}, {001}, {101} and {10$\bar{1}$}. Twinning is ubiquitous, by 180° rotation on [100]. Redcanyonite is translucent with a pale orange streak, is non-fluorescent, has a Mohs hardness of 2, and has brittle tenacity with uneven fracture. Optically, redcanyonite is biaxial (+), α = 1.725(3), β = 1.755(3), γ = 1.850(5) (white light); 2V (meas.) = 60(2)°, 2V (calc.) = 61.3°; and dispersion isr<v, very strong. Pleochroism is:X= orange,Y= yellow andZ= orange;Y<<X<Z. The optical orientation isX=b,Y≈c*,Z≈a. The empirical formula is (NH4)2.02(Mn0.49Cu0.09Zn0.06)Σ0.64H+0.72[(UO2)4O4(S0.99P0.01O4)2](H2O)4, based on 4 U and 24 O apfu. Redcanyonite is monoclinic,C2/m,a= 8.6572(17),b= 14.155(3),c= 8.8430(19) Å, β = 104.117(18)°,V= 1050.9(4) Å3andZ= 2. The structure was refined toR1= 0.0382 for 1079 reflections withIobs> 3σI. Uranyl oxo-sulfate sheets in redcanyonite adopt the well-known zippeite topology, which consists of zigzag chains of uranyl pentagonal bipyramids linked by sulfate tetrahedra to form sheets. The sheets are linked to each other through bonds to interlayer NH4+groups and octahedrally coordinated Mn2+, and by hydrogen bonds from H2O groups. Redcanyonite is named for Red Canyon in southeast Utah, USA.
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Mala, Xhavit, and Qenan Maxhuni. "Sternbergia colchiciflora Waldst. et Kit. (Amaryllidaceae), a new genus and species in the flora of Kosovo." Acta botanica Croatica 79, no. 2 (July 13, 2020): 236–38. http://dx.doi.org/10.37427/botcro-2020-030.
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This paper reports Sternbergia colchiciflora Waldst. et Kit. as a new genus and species for the flora of Kosovo. Almost 30 adult individuals of this species were recorded for the first time in southwestern Kosovo during 2015, within the Canyon of the White Drin at Fshajt Bridge. Considering the low number of individuals and very limited distribution, this species should be treated as a critically endangered taxon in Kosovo.
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Higgins, Anna M., Kristen M. Waring, and Andrea E. Thode. "The effects of burn entry and burn severity on ponderosa pine and mixed conifer forests in Grand Canyon National Park." International Journal of Wildland Fire 24, no. 4 (2015): 495. http://dx.doi.org/10.1071/wf13111.
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Over a century of fire exclusion in frequent-fire ponderosa pine and dry mixed conifer forests has resulted in increased tree densities, heavy surface fuel accumulations and an increase in late successional, fire-intolerant trees. Grand Canyon National Park uses prescribed fires and wildfires to reduce fire hazard and restore ecosystem processes. Research is needed to determine post-fire vegetation response thus enabling future forest succession predictions. Our study focussed on the effects of burn entry and burn severity on species composition and regeneration in two forest types: ponderosa pine with white fir encroachment and dry mixed conifer. We found no difference in tree composition and structure in a single, low-severity burn compared with unburned areas in the white fir encroachment forest type. We found no white fir seedlings or saplings in a second-entry, low-severity burn in the white fir encroachment forest type. Second-entry burns were effective in reducing white fir densities in the white fir encroachment forest type. There was significant aspen regeneration following high-severity fire in the dry mixed conifer forest type. This research suggests that repeated entries and an increase in burn severity may be necessary for prescribed fire or wildfire to be effective in meeting management objectives.
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Nesmith, Jonathan C. B., Micah Wright, Erik S. Jules, and Shawn T. McKinney. "Whitebark and Foxtail Pine in Yosemite, Sequoia, and Kings Canyon National Parks: Initial Assessment of Stand Structure and Condition." Forests 10, no. 1 (January 7, 2019): 35. http://dx.doi.org/10.3390/f10010035.
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The Inventory & Monitoring Division of the U.S. National Park Service conducts long-term monitoring to provide park managers information on the status and trends in biological and environmental attributes including white pines. White pines are foundational species in many subalpine ecosystems and are currently experiencing population declines. Here we present results on the status of whitebark and foxtail pine in the southern Sierra Nevada of California, an area understudied relative to other parts of their ranges. We selected random plot locations in Yosemite, Sequoia, and Kings Canyon national parks using an equal probability spatially-balanced approach. Tree- and plot-level data were collected on forest structure, composition, demography, cone production, crown mortality, and incidence of white pine blister rust and mountain pine beetle. We measured 7899 whitebark pine, 1112 foxtail pine, and 6085 other trees from 2012–2017. All factors for both species were spatially highly variable. Whitebark pine occurred in nearly-pure krummholz stands at or near treeline and as a minor component of mixed species forests. Ovulate cones were observed on 25% of whitebark pine and 69% of foxtail pine. Whitebark pine seedlings were recorded in 58% of plots, and foxtail pine seedlings in only 21% of plots. Crown mortality (8% in whitebark, 6% in foxtail) was low and significantly higher in 2017 compared to previous years. Less than 1% of whitebark and zero foxtail pine were infected with white pine blister rust and <1% of whitebark and foxtail pine displayed symptoms of mountain pine beetle attack. High elevation white pines in the southern Sierra Nevada are healthy compared to other portions of their range where population declines are significant and well documented. However, increasing white pine blister rust and mountain pine beetle occurrence, coupled with climate change projections, portend future declines for these species, underscoring the need for broad-scale collaborative monitoring.
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MOUNTNEY, NIGEL P. "Periodic accumulation and destruction of aeolian erg sequences in the Permian Cedar Mesa Sandstone, White Canyon, southern Utah, USA." Sedimentology 53, no. 4 (August 2006): 789–823. http://dx.doi.org/10.1111/j.1365-3091.2006.00793.x.
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Kampf, Anthony R., Travis A. Olds, Jakub Plášil, Joe Marty, and Samuel N. Perry. "Feynmanite, a new sodium uranyl sulfate mineral from Red Canyon, San Juan County, Utah, USA." Mineralogical Magazine 83, no. 02 (May 28, 2018): 153–60. http://dx.doi.org/10.1180/mgm.2018.117.
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AbstractThe new mineral feynmanite, Na(UO2)(SO4)(OH)·3.5H2O, was found in both the Blue Lizard and Markey mines, San Juan County, Utah, USA, where it occurs as a secondary phase on pyrite-rich asphaltum in association with chinleite-(Y), gypsum, goethite, natrojarosite, natrozippeite, plášilite, shumwayite (Blue Lizard) and wetherillite (Markey). The mineral is pale greenish yellow with a white streak and fluoresces bright greenish white under a 405 nm laser. Crystals are transparent with a vitreous lustre. It is brittle, with a Mohs hardness of ~2, irregular fracture and one perfect cleavage on {010}. The calculated density is 3.324 g cm–3. Crystals are thin needles or blades, flattened on {010} and elongate on [100], exhibiting the forms {010}, {001}, {101} and {10$\bar{1}$}, and are up to ~0.1 mm in length. Feynmanite is optically biaxial (–), with α = 1.534(2), β = 1.561(2) and γ = 1.571(2) (white light); 2Vmeas.= 62(2)°; no dispersion; and optical orientation:X=b,Y≈a,Z≈c. It is weakly pleochroic:X= colourless,Y= very pale green yellow andZ= pale green yellow (X<Y<Z). Electron microprobe analyses (WDS mode) provided (Na0.84Fe0.01)(U1.01O2)(S1.01O4)(OH)·3.5H2O. The five strongest powder X-ray diffraction lines are [dobsÅ(I)(hkl)]: 8.37(100)(010), 6.37(33)($\bar{1}$01,101), 5.07(27)($\bar{1}$11,111), 4.053(46)(004,021) and 3.578(34)(120). Feynmanite is monoclinic, has space groupP2/n,a= 6.927(3),b= 8.355(4),c= 16.210(7) Å, β = 90.543(4)°,V= 938.1(7) Å3andZ= 4. The structure of feynmanite (R1= 0.0371 for 1879Io> 2σI) contains edge-sharing pairs of pentagonal bipyramids that are linked by sharing corners with SO4groups, yielding a [(UO2)2(SO4)2(OH)2]2–sheet based on the phosphuranylite anion topology. The sheet is topologically identical to those in deliensite, johannite and plášilite. The dehydration of feynmanite to plášilite results in interlayer collapse involving geometric reconfiguration of the sheets and the ordering of Na.
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Kampf, Anthony R., Jakub Plášil, Anatoly V. Kasatkin, Barbara P. Nash, and Joe Marty. "Magnesioleydetite and straβmannite, two new uranyl sulfate minerals with sheet structures from Red Canyon, Utah." Mineralogical Magazine 83, no. 03 (May 28, 2018): 349–60. http://dx.doi.org/10.1180/mgm.2018.118.
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AbstractMagnesioleydetite (IMA2017-063), Mg(UO2)(SO4)2·11H2O, and straβmannite (IMA2017-086), Al(UO2)(SO4)2F·16H2O, are two new minerals from mines in Red Canyon, San Juan County, Utah, USA. Magnesioleydetite occurs in the Markey mine and straβmannite occurs in both the Markey and Green Lizard mines. Both minerals are secondary phases found in efflorescent crusts on the surfaces of mine walls. Magnesioleydetite occurs in irregular aggregates (to ~0.5 mm) of blades (to ~0.2 mm) exhibiting the following properties: transparent to translucent; pale green–yellow colour; vitreous lustre; white streak; non-fluorescent; brittle; Mohs hardness ≈ 2; irregular fracture; one perfect cleavage on {001}; and calculated density = 2.463 g/cm3. Straβmannite occurs in irregular aggregates (to ~0.5 mm) of equant crystals (to ~0.2 mm) exhibiting the following properties: transparent; light yellow–green colour; vitreous to greasy lustre; nearly white streak; bright greenish-blue fluorescence; somewhat brittle, Mohs hardness ≈ 1½; irregular fracture; one good cleavage on {001}; measured and calculated densities of 2.20(2) and 2.173 g/cm3, respectively; optically biaxial (–); α = 1.477(2), β = 1.485(2) and γ = 1.489(2) (white light); 2Vmeas.= 72(2)°; dispersionr>v(slight); orientationY=b,X∧c= 20° (in obtuse β); pleochroism withX= nearly colourless,Y= pale green–yellow andZ= light green–yellow (X<Y<Z). The empirical formulas for magnesioleydetite and straβmannite are (Mg0.56Fe0.26Zn0.11Mn0.01)Σ0.94(U0.99O2)(S1.015O4)2·11H2O and Al1.00Na0.16(U0.99O2)(S1.00O4)2[F0.58(OH)0.42]·16H2O, respectively. Magnesioleydetite is monoclinic,C2/c,a= 11.3513(3),b= 7.7310(2),c= 21.7957(15) Å, β = 102.387(7)°,V= 1868.19(16) Å3andZ= 4. Straβmannite is monoclinic,C2/c,a= 11.0187(5),b= 8.3284(3),c= 26.6727(19) Å, β = 97.426(7)°,V= 2427.2(2) andZ= 4. The structures of magnesioleydetite (R1= 0.016 for 2040I> 2σIreflections) and straβmannite (R1= 0.0343 for 2220I> 2σIreflections) each contain uranyl-sulfate sheets based on the protasite-anion topology.
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Schreier, Andrea Drauch, Brian Mahardja, and Bernie May. "Hierarchical patterns of population structure in the endangered Fraser River white sturgeon (Acipenser transmontanus) and implications for conservation." Canadian Journal of Fisheries and Aquatic Sciences 69, no. 12 (December 2012): 1968–80. http://dx.doi.org/10.1139/f2012-120.
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The Fraser River system consists of five white sturgeon (Acipenser transmontanus) management units, two of which are listed as endangered populations under Canada’s Species at Risk Act. The delineation of these management units was based primarily on population genetic analysis with samples parsed by collection location. We used polysomic microsatellite markers to examine population structure in the Fraser River system with samples parsed by collection location and with a genetic clustering algorithm. Strong levels of genetic divergence were revealed above and below Hells Gate, a narrowing of the Fraser canyon further obstructed by a rockslide in 1913. Additional analyses revealed population substructure on the Fraser River above Hells Gate. The Middle Fraser River (SG-3) and Nechako River were found to be distinct populations, while the Upper Fraser River, although currently listed as an endangered population, represented a mixing area for white sturgeon originating from SG-3 and Nechako. Differences between these results and previous genetic investigations may be attributed to the detection of population mixing when genetic clustering is used to infer population structure.
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Hollis-Etter, Karmen M., Robert A. Montgomery, Dwayne R. Etter, Christopher L. Anchor, James E. Chelsvig, Richard E. Warner, Paul R. Grimstad, Diane D. Lovin, and Marvin S. Godsey. "Environmental conditions for Jamestown Canyon virus correlated with population-level resource selection by white-tailed deer in a suburban landscape." PLOS ONE 14, no. 10 (October 7, 2019): e0223582. http://dx.doi.org/10.1371/journal.pone.0223582.
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Mitchell, Sandra, and Bruce Woodward. "Human Effects on Aquatic and Riparian Organisms in the Canyons of Canyonlands and Arches National Parks and Natural Bridges National Monument." UW National Parks Service Research Station Annual Reports 14 (January 1, 1990): 18–20. http://dx.doi.org/10.13001/uwnpsrc.1990.2857.
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We made 1 trip to all three study sites to familiarize ourselves with the study areas and meet and discuss the project with the local Park Service personnel in charge of the project. While the canyon at Arches National Park was as we expected it to be, the canyons in Canyonlands and at Natural Bridges were quite different from other canyons in which we have worked. These later canyons were deeper, had steeper canyon walls, and had thicker vegetation than prior canyons in which we have worked. The tall canyon walls shade the canyon bottom creating great differences in temperature/light/moisture levels over very short distances. The vegetation can change radically just by going around one bend in the canyon bottom. The heterogeneous nature of the habitats in these deep canyons require us to subsample to a much greater degree than we proposed in the original proposal. The local Park Service staff had already anticipated this problem and had suggested in their review of our proposal that we subsample to a greater degree. We have taken our original sampling scheme and broken it into a series of smaller subsamples to solve the problem of heterogeneous habitat types in each treatment type (i.e., area with road, area with trail, etc.).
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Jeong, Mira, Deqiang Sun, Min Luo, Yun Huang, Myunggon Ko, Lucas Chavez, Grant A. Challen, et al. "Large Conserved Domains Of Low DNA Methylation Maintained By 5-Hydroxymethycytosine and Dnmt3a." Blood 122, no. 21 (November 15, 2013): 2406. http://dx.doi.org/10.1182/blood.v122.21.2406.2406.
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Abstract Identification of recurrent leukemia-associated mutations in genes encoding regulators of DNA methylation such as DNMT3A and TET2 have underscored the critical importance of DNA methylation in maintenance of normal physiology. To gain insight into how DNA methylation exerts the central role, we sought to determine the genome-wide pattern of DNA methylation in the normal precursors of leukemia cells: the hematopoietic stem cell (HSC), and investigate the factors that affect alterations in DNA methylation and gene expression. We performed whole genome bisulfite sequencing (WGBS) on purified murine HSCs achieving a total of 1,121M reads, resulting in a combined average of 40X coverage. Using Hidden Markov Model we identified 32,325 under-methylated regions (UMRs) with average proportion of methylation ≤ 10% and by inspecting the UMR size distribution, we discovered exceptionally large “methylation Canyons” which span highly conserved domains frequently containing transcription factors and are quite distinct from CpG islands and shores. Methylation Canyons are a distinct genomic feature that is stable, albeit with subtle differences, across cell-types and species. Canyon-associated genes showed a striking pattern of enrichment for genes involved in transcriptional regulation (318 genes, P=6.2 x 10-123), as well as genes containing a homeobox domain (111 genes, P=3.9 x 10-85). We compared Canyons with TF binding sites as identified from more than 150 ChIP-seq data sets across a variety of blood lineages (>10)19 and found that TF binding peaks for 10 HSC pluripotency TFs are significantly enriched in entirety of Canyons compared with their surrounding regions. Low DNA methylation is usually associated with active gene expression. However, half of Canyon genes associated with H3K27me3 showed low or no expression regardless of their H3K4me3 association while H3K4me3-only Canyon genes were highly expressed. Because DNMT3A is mutated in a high frequency of human leukemias24, we examined the impact of loss of Dnmt3a on Canyon size. Upon knockout of Dnmt3a, the edges of the Canyons are hotspots of differential methylation while regions inside of Canyon are relatively resistant. The methylation loss in Dnmt3a KO HSCs led Canyon edge erosion, Canyon size expansion and addition of 861 new Canyons for a total of 1787 Canyons. Canyons marked with H3K4me3 only were most likely to expand after Dnmt3a KO and the canyons marked only with H3K27me3 or with both marks were more likely to contract. This suggests Dnmt3a specifically is acting to restrain Canyon size where active histone marks (and active transcription) are already present. WGBS cannot distinguish between 5mC and 5hmC, so we determined the genome-wide distribution of 5hmC in WT and Dnmt3a KO HSCs using the cytosine-5-methylenesulphonate (CMS)-Seq method in which sodium bisulfate treatment convert 5hmC to CMS; CMS-containing DNA fragments are then immunoprecipitated using a CMS specific antiserum. Strikingly, 5hmC peaks were enriched specifically at the borders of Canyons. In particular, expanding Canyons, typically associated with highest H3K4me3 marking, were highly enriched at the edges for the 5hmC signal suggesting a model in which Tet proteins and Dnmt3a act concomitantly on Canyon borders opposing each other in alternately effacing and restoring methylation at the edges, particularly at sites of active chromatin marks. Using Oncomine data, we tested whether Canyon-associated genes were likely to be associated with hematologic malignancy development and found Canyon genes were highly enriched in seven signatures of genes over-expressed in Leukemia patients compared to normal bone marrow; in contrast, four sets of control genes were not similarly enriched. Further using TCGA data, we found that expressed canyon genes are significantly enriched for differentially expressed genes between patients with and without DNMT3A mutation (p value<0.05) Overall, 76 expressed canyon genes, including multiple HOX genes, are significantly changed in patients with DNMT3A mutation (p=0.0031). Methylation Canyons, the novel epigenetic landscape we describe may provide a mechanism for the regulation of hematopoiesis and may contribute to leukemia development. Disclosures: No relevant conflicts of interest to declare.
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Olds, Travis A., Luke R. Sadergaski, Jakub Plášil, Anthony R. Kampf, Peter C. Burns, Ian M. Steele, Joe Marty, Shawn M. Carlson, and Owen P. Mills. "Leószilárdite, the first Na,Mg-containing uranyl carbonate from the Markey Mine, San Juan County, Utah, USA." Mineralogical Magazine 81, no. 5 (October 2017): 1039–50. http://dx.doi.org/10.1180/minmag.2016.080.149.
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AbstractLeószilárdite (IMA2015-128), Na6Mg(UO2)2(CO3)6·6H2O, was found in the Markey Mine, Red Canyon, White Canyon District, San Juan County, Utah, USA, in areas with abundant andersonite, natrozippeite, gypsum, anhydrite, and probable hydromagnesite along with other secondary uranium minerals bayleyite, čejkaite and johannite. The new mineral occurs as aggregates of pale yellow bladed crystals flattened on ﹛001﹜ and elongated along [010], individually reaching up to 0.2 mmlong. More commonly it occurs as pale yellow pearlescent masses to 2 mm consisting of very small plates. Leószilárdite fluoresces green under both longwave and shortwave ultraviolet light, and is translucent with a white streak, hardness of 2 (Mohs), and brittle tenacity with uneven fracture. The new mineral is readily soluble in room temperature H2O. Crystals have perfect cleavage along ﹛001﹜, and exhibit the forms ﹛110﹜,﹛001﹜,﹛100﹜,﹛101﹜ and ﹛101﹜. Optically, leószilárdite is biaxial (-), α= 1.504(1), β= 1.597(1), γ= 1.628(1) (white light); 2V (meas.) = 57(1)°, 2V (calc.) = 57.1°; dispersion r > v, slight. Pleochroism: X= colourless, Y and Z= light yellow; X<Y ≈ Z The average of six wavelength dispersive spectroscopic analyses provided Na2O 14.54, MgO 3.05, UO3 47.95, CO2 22.13, H2O 9.51, total 97.18 wt.%. The empirical formula is Na5.60Mg0.90U2O28C6H12.60, based on 28 O apfu. Leószilárdite is monoclinic, C2/m, a = 11.6093(21), b = 6.7843(13), c = 15.1058(28) Å, β = 91.378(3)°, V= 1189.4(4) Å3 and Z = 2. The crystal structure (R1 = 0.0387 for 1394 reflections with Iobs > 4σI), consists of uranyl tricarbonate anion clusters [(UO2)(CO3)3]4- held together in part by irregular chains of NaO5(H2O) polyhedra sub parallel to [010]. Individual uranyl tricarbonate clusters are also linked together by three-octahedron units consisting of two Na-centred octahedra that share the opposite faces of a Mg-centred octahedron at the centre (Na–Mg–Na), and have the composition Na2MgO12(H2O)4. The name of the new mineral honours the Hungarian-American physicist, inventor and biologist Dr. Leó Szilárd (1898–1964).
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Kampf, Anthony R., Jakub Plášil, Anatoly V. Kasatkin, Joe Marty, Jiří Čejka, and Ladislav Lapčák. "Shumwayite, [(UO2)(SO4)(H2O)2]2·H2O, a new uranyl sulfate mineral from Red Canyon, San Juan County, Utah, USA." Mineralogical Magazine 81, no. 2 (April 2017): 273–85. http://dx.doi.org/10.1180/minmag.2016.080.091.
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AbstractThe new mineral shumwayite (IMA2015-058), [(UO2)(SO4)(H2O)2]2·H2O, was found in the Green Lizard and Giveaway-Simplot mines, White Canyon district, San Juan County, Utah, USA, where it occurs as a secondary alteration phase. At the Green Lizard mine, it is found in association with calcite, gypsum, plášilite, pyrite, rozenite and sulfur; at the Giveaway-Simplot mine, shumwayite is associated with rhomboclase and römerite. The mineral occurs as pale greenish-yellow monoclinic prisms, elongated on [100], up to ∼0.3 mm long and commonly in subparallel to random intergrowths. The mineral is transparent with a vitreous lustre and has a white streak. It fluoresces bright greenish white under both longwave and shortwave ultraviolet radiation. The Mohs hardness is ∼2. Crystals are brittle with perfect {011} cleavage and irregular fracture. The mineral is slightly deliquescent and is easily soluble in room temperature H2O. The calculated density is 3.844 g cm–3. Optically, shumwayite is biaxial (+/–), with α = 1.581(1), β= 1.588(1), γ = 1.595(1) (measured in white light). The measured 2Vxbased on extinction data collected on a spindle stage is 89.8(8)°; the calculated 2Vxis 89.6°. Dispersion is strong, but the sense is not defined because the optic sign is ambiguous. No pleochroism was observed. The optical orientation isX=b,Y=c,Z=a. Energy-dispersive spectrometer analyses (with H2O based on the crystal structure) yielded the empirical formula U2.01S1.99O12.00·5H2O.Shumwayite is monoclinic,P21/c,a= 6.74747(15),b= 12.5026(3),c= 16.9032(12) Å, β = 90.919(6)°,V= 1425.79(11) Å3andZ= 4. The crystal structure (R1= 1.88% for 2936F> 4σF) contains UO7pentagonal bipyramids and SO4tetrahedra that link by corner-sharing to form [(UO2)(SO4)(H2O)2] chains along [100]. The chains and isolated H2O groups between them are linked together only by hydrogen bonds. The mineral is named in honour of the Shumway family, whose members account for the discovery and mining of hundreds of uranium deposits on the Colorado Plateau, including the Green Lizard mine.
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Lopez-Fernandez, P., S. Bianchelli, A. Pusceddu, A. Calafat, A. Sanchez-Vidal, and R. Danovaro. "Bioavailability of sinking organic matter in the Blanes canyon and the adjacent open slope (NW Mediterranean Sea)." Biogeosciences 10, no. 5 (May 23, 2013): 3405–20. http://dx.doi.org/10.5194/bg-10-3405-2013.
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Abstract. Submarine canyons are sites of intense energy and material exchange between the shelf and the deep adjacent basins. To test the hypothesis that active submarine canyons represent preferential conduits of available food for the deep-sea benthos, two mooring lines were deployed at 1200 m depth from November 2008 to November 2009 inside the Blanes canyon and on the adjacent open slope (Catalan Margin, NW Mediterranean Sea). We investigated the fluxes, biochemical composition and food quality of sinking organic carbon (OC). OC fluxes in the canyon and the open slope varied among sampling periods, though not consistently in the two sites. In particular, while in the open slope the highest OC fluxes were observed in August 2009, in the canyon the highest OC fluxes occurred in April–May 2009. For almost the entire study period, the OC fluxes in the canyon were significantly higher than those in the open slope, whereas OC contents of sinking particles collected in the open slope were consistently higher than those in the canyon. This result confirms that submarine canyons are effective conveyors of OC to the deep sea. Particles transferred to the deep sea floor through the canyons are predominantly of inorganic origin, significantly higher than that reaching the open slope at a similar water depth. Using multivariate statistical tests, two major clusters of sampling periods were identified: one in the canyon that grouped trap samples collected in December 2008, concurrently with the occurrence of a major storm at the sea surface, and associated with increased fluxes of nutritionally available particles from the upper shelf. Another cluster grouped samples from both the canyon and the open slope collected in March 2009, concurrently with the occurrence of the seasonal phytoplankton bloom at the sea surface, and associated with increased fluxes of total phytopigments. Our results confirm the key ecological role of submarine canyons for the functioning of deep-sea ecosystems, and highlight the importance of canyons in linking episodic storms and primary production occurring at the sea surface to the deep sea floor.
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Heizler, Matthew T., Karl E. Karlstrom, Micael Albonico, Richard Hereford, L. Sue Beard, Steven M. Cather, Laurie J. Crossey, and Kurt E. Sundell. "Detrital sanidine 40Ar/39Ar dating confirms <2 Ma age of Crooked Ridge paleoriver and subsequent deep denudation of the southwestern Colorado Plateau." Geosphere 17, no. 2 (February 25, 2021): 438–54. http://dx.doi.org/10.1130/ges02319.1.
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Abstract Crooked Ridge and White Mesa in northeastern Arizona (southwestern United States) preserve, as inverted topography, a 57-km-long abandoned alluvial system near the present drainage divide between the Colorado, San Juan, and Little Colorado Rivers. The pathway of this paleoriver, flowing southwest toward eastern Grand Canyon, has led to provocative alternative models for its potential importance in carving Grand Canyon. The ∼50-m-thick White Mesa alluvium is the only datable record of this paleoriver system. We present new 40Ar/39Ar sanidine dating that confirms a ca. 2 Ma maximum depositional age for White Mesa alluvium, supported by a large mode (n = 42) of dates from 2.06 to 1.76 Ma. Older grain modes show abundant 37–23 Ma grains mostly derived ultimately from the San Juan Mountains, as is also documented by rare volcanic and basement pebbles in the White Mesa alluvium. A tuff with an age of 1.07 ± 0.05 Ma is inset below, and hence provides a younger age bracket for the White Mesa alluvium. Newly dated remnant deposits on Black Mesa contain similar 37–23 Ma grains and exotic pebbles, plus a large mode (n = 71) of 9.052 ± 0.003 Ma sanidine. These deposits could be part of the White Mesa alluvium without any Pleistocene grains, but new detrital sanidine data from the upper Bidahochi Formation near Ganado, Arizona, have similar maximum depositional ages of 11.0–6.1 Ma and show similar 40–20 Ma San Juan Mountains–derived sanidine. Thus, we tentatively interpret the <9 Ma Black Mesa deposit to be a remnant of an 11–6 Ma Bidahochi alluvial system derived from the now-eroded southwestern fringe of the San Juan Mountains. This alluvial fringe is the probable source for reworking of 40–20 Ma detrital sanidine and exotic clasts into Oligocene Chuska Sandstone, Miocene Bidahochi Formation, and ultimately into the <2 Ma White Mesa alluvium. The <2 Ma age of the White Mesa alluvium does not support models that the Crooked Ridge paleoriver originated as a late Oligocene to Miocene San Juan River that ultimately carved across the Kaibab uplift. Instead, we interpret the Crooked Ridge paleoriver as a 1.9–1.1 Ma tributary to the Little Colorado River, analogous to modern-day Moenkopi Wash. We reject the “young sediment in old paleovalley” hypothesis based on mapping, stratigraphic, and geomorphic constraints. Deep exhumation and beheading by tributaries of the San Juan and Colorado Rivers caused the Crooked Ridge paleotributary to be abandoned between 1.9 and 1.1 Ma. Thermochronologic data also provide no evidence for, and pose substantial difficulties with, the hypothesis for an earlier (Oligocene–Miocene) Colorado–San Juan paleoriver system that flowed along the Crooked Ridge pathway and carved across the Kaibab uplift.
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Lv, Weixun, Yan Wu, and Jianbin Zang. "A Review on the Dispersion and Distribution Characteristics of Pollutants in Street Canyons and Improvement Measures." Energies 14, no. 19 (September 27, 2021): 6155. http://dx.doi.org/10.3390/en14196155.
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The air quality in a street canyon seriously affects the exposure level of pollutants for pedestrians and is directly related to the indoor air quality (IAQ) of surrounding buildings. In order to improve the street canyon environment, it is necessary to clarify the distribution and dispersion characteristics of pollutants. Through field tests, wind tunnel experiments, and numerical simulation, the current research studied the nature of pollutants in street canyons and provided some improvement measures. This paper comprehensively introduces the characteristics of pollutants in street canyons and reviews past studies on the following parts: (a) the dispersion principle and main impact factors of pollutants in street canyons, (b) the spatial and temporal distribution of pollutants in street canyons, (c) the relationship between pollutants in street canyons and indoor air quality, and (d) improvement measures of the street canyon environment. The dispersion of pollutants is dominated by the air exchange between the street canyon and the upper atmosphere, which is strengthened when the wind speed is high or when the temperature in the street canyon is obviously higher than the surrounding area. The heat island effect is beneficial for pollutant dispersion, while the inversion layer has a negative influence. Dense buildings mean lower pollutant diffusion capacity, which causes pollutants to easily gather. Pollutants tend to accumulate on the leeward side of buildings. The concentration of pollutants decreases with the increase of height and drops to the background level at a height of several hundred meters. The temporal distribution of pollutants in street canyons varies in diurnal, weekly, and annual periods, and the concentration peaks in the winter morning and summer evening. Besides, pollutants in street canyons have a significant influence on IAQ. To improve the street canyon environment, green belts and other facilities should be reasonably set up in the streets. Future research should pay attention to comprehensive test data, solving disagreement conclusions, and quantitative evaluation of the various impact factors on pollutants, etc.
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Rocheleau, J. P., P. Michel, L. R. Lindsay, M. Drebot, A. Dibernardo, N. H. Ogden, A. Fortin, and J. Arsenault. "Risk factors associated with seropositivity to California serogroup viruses in humans and pet dogs, Quebec, Canada." Epidemiology and Infection 146, no. 9 (May 2, 2018): 1167–76. http://dx.doi.org/10.1017/s0950268818001000.
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AbstractJamestown Canyon and snowshoe hare viruses are two emerging human pathogens associated with cases of neuroinvasive disease in North America. This study aimed to identify environmental and individual risk factors for seropositivity to these arboviruses in humans and pet dogs from Québec, Canada, 2012–2014. In humans, areas with moderate densities of white-tailed deer (Odocoileus virginianus) were associated with higher odds of seropositivity compared with areas with low densities of white-tailed deer (OR 2.50, P = 0.009) and odds of seropositivity were higher in males than in females (OR 2.03, P = 0.016). Among humans reporting more than 10 mosquito bites weekly, the odds of being seropositive were 4.44 times higher (P = 0.004) for people living in hardwood forested areas. Exposure to areas with coniferous forests was identified as the main environmental risk factor for seroconversion in dogs (OR 2.39, P = 0.04). These findings may help target further public health research, diagnostic and surveillance efforts in Canada.
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Riley, Kerry E., Tammy M. Rittenour, Joel L. Pederson, and Patrick Belmont. "Erosion rates and patterns in a transient landscape, Grand Staircase, southern Utah, USA." Geology 47, no. 9 (June 19, 2019): 811–14. http://dx.doi.org/10.1130/g45993.1.
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AbstractCosmogenic 10Be concentrations in alluvial sediment are widely used to infer long-term, catchment-averaged erosion rates based on the assumption that the landscape is in mass-flux steady state. However, many landscapes are out of equilibrium over millennial time scales due to tectonic and climatic forcing. The Grand Staircase of the Colorado Plateau (North America) is a transient landscape, adjusting to base-level fall from the carving of the Grand Canyon, and is characterized by cliff-bench topography caused by differential erosion of lithologic units. The 10Be concentrations from 52 alluvial and colluvial samples, collected in nested fashion from five catchments, produced inferred erosion rates ranging from 20 to >3500 m/m.y. (or mm/k.y.). We attribute this high variance in part to lithologic-controlled steepness and hotspots of erosion related to cliff retreat along the White Cliffs (escarpment near Mt. Carmel Junction, Utah), as well as headward drainage expansion along the uppermost Pink Cliffs (escarpment within Bryce Canyon National Park). Results from the downslope Vermillion Cliffs (near Kanab) indicate lower erosion rates despite similar slope and rock types, suggesting knick-zone migration has passed that lower region of our study area. The 10Be concentrations measured along trunk streams systematically match local, subcatchment erosion rates, with muted influence from upstream sediment sources. This is consistent with intermittent sediment conveyance between cliff and bench terrain, with sediment storage and localized release associated with ephemeral arroyo systems in the region. Therefore, while detrital cosmogenic nuclide records in transient landscapes may not directly reflect upstream catchment-averaged erosion rates, 10Be inventories can provide insight into unsteady upslope-directed erosion and downslope-directed sediment conveyance in these dynamic landscapes.
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Lopez-Fernandez, P., S. Bianchelli, A. Pusceddu, A. Calafat, A. Sanchez-Vidal, and R. Danovaro. "Bioavailability of sinking organic matter in the Blanes canyon and the adjacent open slope (NW Mediterranean Sea)." Biogeosciences Discussions 9, no. 12 (December 17, 2012): 18295–330. http://dx.doi.org/10.5194/bgd-9-18295-2012.
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Abstract. Submarine canyons are sites of intense energy and material exchange between the shelf and the deep adjacent basins. To test the hypothesis that active submarine canyons represent preferential conduits of available food for the deep-sea benthos, two mooring lines were deployed at 1200 m depth from November 2008 to November 2009 inside the Blanes canyon and on the adjacent open slope (Catalan Margin, NW Mediterranean Sea). We investigated the fluxes, biochemical composition and food quality of sinking organic carbon (OC). OC fluxes in the canyon and the open slope varied among sampling periods, though not consistently in the two sites. In particular, while in the open slope the highest OC fluxes were observed in August 2009, in the canyon the highest OC fluxes occurred in April–May 2009. For almost the entire study period, the OC fluxes in the canyon were significantly higher than those in the open slope, whereas OC contents of sinking particles collected in the open slope were consistently higher than those in the canyon. This result confirms that submarine canyons are effective conveyors of OC to the deep sea, particles transferred are predominantly of inorganic origin, significantly higher than that reaching the open slope at a similar water depth. Using multivariate statistical tests, two major clusters of sampling periods were identified: one in the canyon that grouped trap samples collected in December 2008, concurrently with the occurrence of a major storm at the sea surface, and associated with increased fluxes of nutritionally available particles from the upper shelf. Another cluster grouped samples from both the canyon and the open slope collected in March 2009, concurrently with the occurrence of the seasonal phytoplankton bloom at the sea surface, and associated with increased fluxes of total phytopigments. Our results confirm the key ecological role of submarine canyons for the functioning of deep-sea ecosystems, and highlight the importance of canyons in linking episodic storms and primary production occurring at the sea surface to the deep sea floor.
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Kampf, A. R., J. Plášil, A. V. Kasatkin, and J. Marty. "Belakovskiite, Na7(UO2)(SO4)4(SO3OH)(H2O)3, a new uranyl sulfate mineral from the Blue Lizard mine, San Juan County, Utah, USA." Mineralogical Magazine 78, no. 3 (June 2014): 639–49. http://dx.doi.org/10.1180/minmag.2014.078.3.12.
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AbstractThe new mineral belakovskiite (IMA2013-075), Na7(UO2)(SO4)4(SO3OH)(H2O)3, was found in the Blue Lizard mine, Red Canyon, White Canyon district, San Juan County, Utah, USA, where it occurs as a secondary alteration phase in association with blödite, ferrinatrite, kröhnkite, meisserite and metavoltine. Crystals of belakovskiite are very pale yellowish-green hair-like fibres up to 2 mm long and usually no more than a few mm in diameter. The fibres are elongated on [100] and slightly flattened on {021}. Crystals are transparent with a vitreous lustre. The mineral has a white streak and a probable Mohs hardness of ∼2. Fibres are flexible and elastic, with brittle failure and irregular fracture. No cleavage was observed. The mineral is readily soluble in cold H2O. The calculated density is 2.953 g cm−3. Optically, belakovskiite is biaxial (+) with α = 1.500(1), β = 1.511(1) and γ = 1.523(1) (measured in white light). The measured 2V is 87.1(6)° and the calculated 2V is 88°. The mineral is non-pleochroic. The partially determined optical orientation is X ≈ a. Electron-microprobe analysis provided Na2O 21.67, UO3 30.48, SO3 40.86, H2O 6.45 (structure), total 99.46 wt.% yielding the empirical formula Na6.83(U1.04O2)(SO4)4(S0.99O3OH)(H2O)3 based on 25 O a.p.f.u. Belakovskiite is triclinic, P, with a = 5.4581(3), b = 11.3288(6), c = 18.4163(13) Å, α = 104.786(7)°, β = 90.092(6)°, γ = 96.767(7)°, V = 1092.76(11) Å3 and Z = 2. The eight strongest X-ray powder diffraction lines are [dobs Å(I)(hkl)]: 8.96(35)(002), 8.46(29)(011), 5.19(100)(01,101,10), 4.66(58)(013,02,0,110), 3.568(37)(120,023,005,03), 3.057(59)(06,15,31), 2.930(27)(multiple) and 1.8320(29)(multiple). The structure, refined to R1 = 5.39% for 3163 Fo > 4σF reflections, contains [(UO2)(SO4)4(H2O)]6− polyhedral clusters connected via an extensive network of Na−O bonds and H bonds involving eight Na sites, three other H2O sites and an SO3OH (hydrosulfate) group. The 3-D framework, thus defined, is unique among known uranyl sulfate structures. The mineral is named for Dmitry Ilych Belakovskiy, a prominent Russian mineralogist and Curator of the Fersman Mineralogical Museum.
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di Fiore, Vincenzo, Gemma Aiello, and Bruno D'Argenio. "Gravity instabilities in the Dohrn Canyon (Bay of Naples, Southern Tyrrhenian Sea): potential wave and run-up (tsunami) reconstruction from a fossil submarine landslide." Geologica Carpathica 62, no. 1 (February 1, 2011): 55–63. http://dx.doi.org/10.2478/v10096-011-0005-z.
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Gravity instabilities in the Dohrn Canyon (Bay of Naples, Southern Tyrrhenian Sea): potential wave and run-up (tsunami) reconstruction from a fossil submarine landslideWe discuss a mathematical model for wave and run-up generated submarine landslides in the canyons of the Bay of Naples (Magnaghi-Dohrn canyon system). The morpho-bathymetry and submarine gravity instabilities of such incisions have been investigated through the interpretation of a high resolution DEM. The canyons are located in a sector of the bay where there is a variable interaction of volcanic activity (Phlegrean Fields and Ischia and Procida Islands) with sedimentary processes due to the Sarno-Sebeto rivers. At present the Naples canyon-system is inactive, as is shown by the Holocene sedimentary drapes deposited during the present sea-level highstand, but gravity instabilities occurred in the recent past at the canyons' heads. In particular the Dohrn Canyon is characterized by a double regressive head, while the Magnaghi Canyon shows a trilobate head, formed by the junction of three main tributary channels and coincident with the retreat of the shelf break around the 140 m isobath. The results of a simulation of failures in the above source areas show that the amplitude of wave run-up, expressed in terms of the sea floor depth percentage, may range up to 2.5 % of the water depth at the sea bottom.
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Grimstad, Paul R., Diane G. Williams, and Stephen M. Schmitt. "INFECTION OF WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS) IN MICHIGAN WITH JAMESTOWN CANYON VIRUS (CALIFORNIA SEROGROUP) AND THE IMPORTANCE OF MATERNAL ANTIBODY IN VIRAL MAINTENANCE." Journal of Wildlife Diseases 23, no. 1 (January 1987): 12–22. http://dx.doi.org/10.7589/0090-3558-23.1.12.
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Gori, A., C. Orejas, T. Madurell, L. Bramanti, M. Martins, E. Quintanilla, P. Marti-Puig, et al. "Bathymetrical distribution and size structure of cold-water coral populations in the Cap de Creus and Lacaze-Duthiers canyons (northwestern Mediterranean)." Biogeosciences Discussions 9, no. 12 (December 21, 2012): 19053–84. http://dx.doi.org/10.5194/bgd-9-19053-2012.
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Abstract. Submarine canyons are known as one of the seafloor morphological features where living cold-water coral (CWC) communities develop in the Mediterranean Sea. We investigated the CWC community of the two westernmost submarine canyons of the Gulf of Lions canyon system: the Cap de Creus Canyon (CCC) and Lacaze Duthiers Canyon (LDC). Coral associations have been studied through video material recorded by means of a manned submersible and a remotely operated vehicle. Video transects have been conducted and analyzed in order to obtain information on (1) coral bathymetric distribution and density patterns, (2) size structure of coral populations, and (3) coral colony orientation with respect to the substrate. Madrepora oculata was the most abundant CWC in both canyons, while Lophelia pertusa and Dendrophyllia cornigera mostly occurred as isolated colonies or in small patches. An important exception was detected in a vertical cliff in LDC where a large Lophelia pertusa framework was documented. This is the first record of such an extended L. pertusa framework in the Mediterranean Sea. In both canyons coral populations were dominated by medium and large colonies, but the frequent presence of small-sized colonies also indicate active recruitment. The predominant coral orientation with respect to the substrate (90° and 135°) is probably driven by the current regime as well as by the sediment load transported by the current flows. In general no clear differences were observed between the CWC populations from CCC and LDC, despite large differences in particulate matter between canyons.
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Goehring, Brianna J., Karen L. Launchbaugh, and Linda M. Wilson. "Late-Season Targeted Grazing of Yellow Starthistle (Centaurea solstitialis) with Goats in Idaho." Invasive Plant Science and Management 3, no. 2 (August 2010): 148–54. http://dx.doi.org/10.1614/ipsm-d-09-00004.1.
Full textAbstract:
AbstractYellow starthistle (Centaurea solstitialis) is an exotic winter annual forb that is aggressively invasive and problematic in much of California, Idaho, Oregon, and Washington. Yellow starthistle control is particularly challenging in canyon rangelands where accessibility limits control options. Our objective was to evaluate the effects of late-season targeted goat grazing on yellow starthistle and nontarget grasses and forbs. A 3-yr grazing study was initiated in 2006 on a 380-ha (939 acres) canyon grassland site infested with yellow starthistle near White Bird, ID. Twenty-four paired plots were established, with each pair including a fenced subplot to exclude grazing and a similar-sized adjacent subplot that was grazed. Density of yellow starthistle plants and seedheads was assessed after grazing of each plot in all 3 yr and before grazing in the second and third years. Canopy cover of yellow starthistle, grasses, and forbs also was measured. Grazed subplots had 58% fewer yellow starthistle plants than the ungrazed controls after grazing was applied and 94% fewer seedheads after 3 yr of grazing. Cover of yellow starthistle did not differ between grazed and ungrazed subplots after grazing in 2006, whereas grazing decreased yellow starthistle cover in 2007 and 2008 by about 75%. Goat grazing had little impact on canopy cover of grasses and resident forbs, with the exception of after grazing in 2007 when there was less forb cover in grazed areas compared with ungrazed areas. Late-season (i.e., July to November) targeted goat grazing appears to be an effective way to reduce yellow starthistle plant densities at landscape scales, which creates a large window of opportunity for grazing treatment and flexibility for land and livestock managers.
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Lorance, Pascal, Franz Uiblein, and Daniel Latrouite. "Habitat, behaviour and colour patterns of orange roughy Hoplostethus atlanticus (Pisces: Trachichthyidae) in the Bay of Biscay." Journal of the Marine Biological Association of the United Kingdom 82, no. 2 (April 2002): 321–31. http://dx.doi.org/10.1017/s0025315402005519.
Full textAbstract:
Analyses of 13 submersible dives on the continental slope of the Bay of Biscay (north-east Atlantic) showed that: (i) orange roughy formed dense aggregation of more than 4000 individuals per ha close to the bottom of a small underwater canyon. In all other study areas only a few individuals were observed. Orange roughy aggregations are probably associated with areas of high water mass movements and mixing; (ii) most individuals observed within this aggregation or in its peripheral areas were behaviourally inactive and could be approached with the submersible at close distance; (iii) a large number of these orange roughy showed a completely pigmentless white, or weak red coloration, never observed from specimens caught in trawls. Two individuals which were disturbed by the submarine changed from white to the ‘typical’ red coloration.These observations suggest fine tuning of the foraging strategy and life cycle of the species. It is speculated that, as an active predator of a sparse food resource, orange roughy has developed adaptations to exploit areas with specific hydrological conditions which offer high prey encounter rates and shelter during metabolic relaxation phases between foraging trips.
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Gori, A., C. Orejas, T. Madurell, L. Bramanti, M. Martins, E. Quintanilla, P. Marti-Puig, et al. "Bathymetrical distribution and size structure of cold-water coral populations in the Cap de Creus and Lacaze-Duthiers canyons (northwestern Mediterranean)." Biogeosciences 10, no. 3 (March 25, 2013): 2049–60. http://dx.doi.org/10.5194/bg-10-2049-2013.
Full textAbstract:
Abstract. Submarine canyons are known as one of the seafloor morphological features where living cold-water coral (CWC) communities develop in the Mediterranean Sea. We investigated the CWC community of the two westernmost submarine canyons of the Gulf of Lions canyon system: the Cap de Creus Canyon (CCC) and Lacaze-Duthiers Canyon (LDC). Coral associations have been studied through video material recorded by means of a manned submersible and a remotely operated vehicle. Video transects have been conducted and analyzed in order to obtain information on (1) coral bathymetric distribution and density patterns, (2) size structure of coral populations, and (3) coral colony position with respect to the substrate. Madrepora oculata was the most abundant CWC in both canyons, while Lophelia pertusa and Dendrophyllia cornigera mostly occurred as isolated colonies or in small patches. An important exception was detected in a vertical cliff in LDC where a large L. pertusa framework was documented. This is the first record of such an extended L. pertusa framework in the Mediterranean Sea. In both canyons coral populations were dominated by medium and large colonies, but the frequent presence of small-sized colonies also indicate active recruitment. The predominant coral orientation (90° and 135°) is probably driven by the current regime as well as by the sediment load transported by the current flows. In general, no clear differences were observed in the abundance and in the size structure of the CWC populations between CCC and LDC, despite large differences in particulate matter between canyons.
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Gonzalez Olivardia, Franchesca G., Tomohito Matsuo, Hikari Shimadera, and Akira Kondo. "Impacts of the Tree Canopy and Chemical Reactions on the Dispersion of Reactive Pollutants in Street Canyons." Atmosphere 12, no. 1 (December 30, 2020): 34. http://dx.doi.org/10.3390/atmos12010034.
Full textAbstract:
Traffic-related air pollution in street canyons can cause health problems for pedestrians. In order to clarify the behavior of reactive pollutants, such as NOx and O3, in street canyons, a computational fluid dynamics (CFD) model coupled with a chemistry model and tree canopy model was developed, and then, a set of numerical experiments were performed to investigate the impacts of chemical reactions and aerodynamic effects of trees planted in a canyon. The results were compared with the observation data. Through the results of the numerical experiments designed to simulate a realistic urban street canyon, it was found that chemical reactions have a dominant impact on the NO/NO2 ratio and O3 concentration. While the tree canopy had little impact on the NO/NO2 ratio, it had a moderate impact on the flow field in the canyon and the amount of NOx and O3 in the canyon. In accordance with the aerodynamic effects of tree canopies, the local NOx concentration in the experiments increased and decreased by up to 51% and 11%, respectively. The current findings of this study demonstrate the utility of the proposed model for conducting air quality investigations in urban areas.
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Thurnherr, A. M., L. C. St. Laurent, K. G. Speer, J. M. Toole, and J. R. Ledwell. "Mixing Associated with Sills in a Canyon on the Midocean Ridge Flank*." Journal of Physical Oceanography 35, no. 8 (August 1, 2005): 1370–81. http://dx.doi.org/10.1175/jpo2773.1.
Full textAbstract:
Abstract To close the global overturning circulation, the production and sinking of dense water at high latitudes must be balanced elsewhere by buoyancy gain and upward vertical motion. Hydrographic and microstructure observations from the Brazil Basin in the South Atlantic Ocean indicate that most of the abyssal mixing there takes place on the topographically rough flank of the midocean ridge. In previous studies it has been suggested that the high level of abyssal mixing observed on the ridge flank is primarily caused by breaking internal waves forced by tidal currents. Here, the results from a detailed analysis of velocity, hydrographic, and microstructure data from a ridge-flank canyon are presented. Two-year-long current-meter records indicate that within the canyon there is a significant along-axial mean flow down the density gradient toward the ridge crest. Five hundred meters above the canyon floor the kinetic energy in the subinertial band exceeds that associated with the semidiurnal tides by approximately a factor of 2. The mean dissipation of kinetic energy inside the canyon exceeds that above the ridge-flank topography by approximately a factor of 5. The largest dissipation values were observed downstream of a narrow, 1000-m-high sill that extends across the full width of the canyon. Along the entire canyon, there is a strong association between the presence of sills and along-axial density gradients, while there is no similar association between the presence of depressions and density gradients. Together, these observations suggest that sill-related mixing contributes at least as much to the diapycnal buoyancy flux in the canyon as tidally forced internal-wave breaking, which is not expected to be associated preferentially with sills. While only ≈15% of the interfacial area between Antarctic Bottom Water and North Atlantic Deep Water in the Brazil Basin lie inside canyons, the available data suggest that approximately one-half of the diapycnal buoyancy fluxes take place there. In comparison, the region above the ridge-flank topography accounts for about one-third of the buoyancy fluxes. The apparent importance of sill-related processes for mixing in ridge-flank canyons is therefore of global significance, especially considering that such canyons occur on average every 50 km along 2/3 of the global midocean ridge system, and that sills partially block the canyon axes every few tens of kilometers.
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Cintolesi, Carlo, Francesco Barbano, and Silvana Di Sabatino. "Large-Eddy Simulation Analyses of Heated Urban Canyon Facades." Energies 14, no. 11 (May 25, 2021): 3078. http://dx.doi.org/10.3390/en14113078.
Full textAbstract:
Thermal convective flows are common phenomena in real urban canyons and strongly affect the mechanisms of pollutant removal from the canyon. The present contribution aims at investigating the complex interaction between inertial and thermal forces within the canyon, including the impacts on turbulent features and pollutant removal mechanisms. Large-eddy simulations reproduce infinitely long square canyons having isothermal and differently heated facades. A scalar source on the street mimics the pollutant released by traffic. The presence of heated facades triggers convective flows which generate an interaction region around the canyon-ambient interface, characterised by highly energetic turbulent fluxes and an increase of momentum and mass exchange. The presence of this region of high mixing facilitates the pollutant removal across the interface and decreases the urban canopy drag. The heating-up of upwind facade determines favourable convection that strengthens the primary internal vortex and decreases the pollutant concentration of the whole canyon by 49% compare to the isothermal case. The heating-up of the downwind facade produces adverse convection counteracting the wind-induced motion. Consequently, the primary vortex is less energetic and confined in the upper-canyon area, while a region of almost zero velocity and high pollution concentration (40% more than the isothermal case) appears at the pedestrian level. Finally, numerical analyses allow a definition of a local Richardson number based on in-canyon quantities only and a new formulation is proposed to characterise the thermo-dynamics regimes.
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Zong-Jie, Fang. "Guizhoumyophoria, a New Name for Quadratia Yin, 1974 (Bivalvia: Trigonioida: Myophoriidae), preoccupied by Quadratia Muir-Wood and Cooper, 1960 (Brachiopoda: Strophomenida: Productellidae)." Journal of Paleontology 83, no. 6 (November 2009): 998. http://dx.doi.org/10.1666/09-081.1.
Full textAbstract:
Yin (1974, p. 25) introduced a new genus, Quadratia for a group of Middle Triassic bivalves in the family Myophoriidae. The type species designated by him is Quadratia quadrata Yin, 1974 [p. 25, pl. 1, figs. 3 (syntype, holotype in original text, right valve), 4a–c (syntype, holotype in original text, left valve), 5 (syntype, paratype in original text); text-fig. 3], the type stratum and locality of which are the Qingyan Formation at Qingyan of Guiyang, Guizhou Province, Southwest China (see also Fang et al., 2009, p. 56, Figs. 16.18–16.21). But this genus name has been preoccupied by Quadratia Muir-Wood and Cooper, 1960 (p. 161, pl. 39, figs. 1–13), which is a member of the Productellidae in the Brachiopoda, with Quadratia hirsutiformis (Walcott, 1884, p. 133, pl. 2, figs. 10, 10a) as the type species, which comes from the White Pine shale of Mississippian age at Applegate Canyon of White Pine County, Nevada, USA. As required by ICZN (International Code of Zoological Nomenclature, Fourth edition; Ride et al., 1999) Article 60.3, I replace Quadratia Yin, 1974, with Guizhoumyophoria, new name, based on the same type species, Quadratia quadrata Yin. The new name is derived from Guizhou Province where the genus occurred.
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Allen, S. E., C. Vindeirinho, R. E. Thomson, M. GG Foreman, and D. L. Mackas. "Physical and biological processes over a submarine canyon during an upwelling event." Canadian Journal of Fisheries and Aquatic Sciences 58, no. 4 (April 1, 2001): 671–84. http://dx.doi.org/10.1139/f01-008.
Full textAbstract:
Short, shelf-break canyons are shown to have a substantial influence on local water properties and zooplankton distribution. Barkley Canyon (6 km long) off the west coast of Vancouver Island was extensively sampled in July 1997 and found to have water property and current patterns similar to those observed over Astoria Canyon (22 km long) off the coast of Washington State. Results from Barkley Canyon reveal that the canyon influence can occur very close to the surface (at the thermocline depth of 10 m) and that, near the canyon rim, the stretching vorticity generated over the canyon is strong enough to produce a closed cyclonic eddy of sufficient strength to trap deep passively drifting tracers. Most zooplankton species are advected by the currents; those near the ocean surface pass over the canyon, while those at depth are advected toward the coast. Euphausiids (Euphausia pacifica and Thysanoessa spinifera), the strongest swimming zooplankton collected in the 1997 study, were most prevalent in the closed eddy region near the head of the canyon. The observed aggregation of these animals appears to be linked to their ability to remain at specific depths combined with advection by horizontally convergent flows in the eddy.
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Waterhouse, Amy F., Jennifer A. Mackinnon, Ruth C. Musgrave, Samuel M. Kelly, Andy Pickering, and Jonathan Nash. "Internal Tide Convergence and Mixing in a Submarine Canyon." Journal of Physical Oceanography 47, no. 2 (February 2017): 303–22. http://dx.doi.org/10.1175/jpo-d-16-0073.1.
Full textAbstract:
AbstractObservations from Eel Canyon, located on the north coast of California, show that elevated turbulence in the full water column arises from the convergence of remotely generated internal wave energy. The incoming semidiurnal and bottom-trapped diurnal internal tides generate complex interference patterns. The semidiurnal internal tide sets up a partly standing wave within the canyon due to reflection at the canyon head, dissipating all of its energy within the canyon. Dissipation in the near bottom is associated with the diurnal trapped tide, while midwater isopycnal shear and strain is associated with the semidiurnal tide. Dissipation is elevated up to 600 m off the bottom, in contrast to observations over the flat continental shelf where dissipation occurs closer to the topography. Slope canyons are sinks for internal wave energy and may have important influences on the global distribution of tidally driven mixing.
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Fairweather, M. L., and B. W. Geils. "First Report of the White Pine Blister Rust Pathogen, Cronartium ribicola, in Arizona." Plant Disease 95, no. 4 (April 2011): 494. http://dx.doi.org/10.1094/pdis-10-10-0699.
Full textAbstract:
White pine blister rust, caused by Cronartium ribicola J.C. Fisch., was found on southwestern white pine (Pinus flexilis James var. reflexa Engelm., synonym P. strobiformis Engelm.) near Hawley Lake, Arizona (Apache County, White Mountains, 34.024°N, 109.776°W, elevation 2,357 m) in April 2009. Although white pines in the Southwest (Arizona and New Mexico) have been repeatedly surveyed for blister rust since its discovery in the Sacramento Mountains of southern New Mexico in 1990 (1,2), this was the first confirmation of C. ribicola in Arizona. Numerous blister rust cankers were sporulating on 15- to 30-year-old white pines growing in a mixed conifer stand adjacent to a meadow with orange gooseberry bushes (Ribes pinetorum Greene), a common telial host in New Mexico. Most of the observed cankers were producing their first aecia on 5-year-old branch interwhorl segments (i.e., formed in 2004). The two oldest cankers apparently originated on stemwood formed about 14 and 21 years before (1995 and 1988). Neither uredinia nor telia were seen on expanding gooseberry leaves in late April, but these rust structures were found later in the season. Voucher specimens deposited in the Forest Pathology Herbarium-Fort Collins (FPF) were determined by host taxa and macro- and microscopic morphology as C. ribicola–white pine with typical cankers, aecia, and aeciospores (1). Six collections of aeciospores from single, unopened aecia provided rDNA sequences (ITS1-5.8S-ITS2, primers ITS1F and ITS4) with two different repeat types (GenBank Accession Nos. HM156043 and HM156044 [J. W. Hanna conducted analysis with methods described in 3]). A BLASTn search with these sequences showed 100 and 99% similarities, respectively, with sequences of C. ribicola, including accessions L76496, L76498, and L76499 from California (4). Additional reconnaissance of white pines on the Fort Apache Indian Reservation and neighboring Apache-Sitgreaves National Forests was conducted from May through September 2009. Although the blister rust infestation was distributed over more than 100 km2 of forest type, infected trees were restricted to mesic and wet canyon bottoms (climatically high-hazard sites) and were not found on dry sites–even where aecial and telial hosts occurred together. Recent dispersal within the White Mountains was suggested by a presence of infected gooseberry plants on several sites where infected white pines were not yet evident. Geils et al. (1) concluded that the initial infestation in New Mexico had originated by long-distance, aerial transport from California to the Sacramento Mountains in 1969. Since then, numerous additional infestations in the Southwest have been discovered; but we do not know which of these (including Arizona) resulted by dispersal from California or New Mexico. Although rust may eventually infest many host populations in the Southwest and disease may kill most trees in some locations, differences in site hazard and spread provide managers with numerous opportunities to maintain white pines and Ribes spp. References: (1) B. Geils et al. For. Pathol. 40:147, 2010. (2) F. Hawksworth. Plant Dis. 74:938, 1990. (3) M.-S. Kim et al. For. Pathol. 36:145, 2006. (4) D. Vogler and T. Bruns. Mycologia 90:244, 1998.
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Bonneau, David A., D. Jean Hutchinson, Paul-Mark DiFrancesco, Melanie Coombs, and Zac Sala. "Three-dimensional rockfall shape back analysis: methods and implications." Natural Hazards and Earth System Sciences 19, no. 12 (December 4, 2019): 2745–65. http://dx.doi.org/10.5194/nhess-19-2745-2019.
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Abstract. Rockfall is a complex natural process that can present risks to the effective operation of infrastructure in mountainous terrain. Remote sensing tools and techniques are rapidly becoming the state of the practice in the characterization, monitoring and management of these geohazards. The aim of this study is to address the methods and implications of how the dimensions of three-dimensional rockfall objects, derived from sequential terrestrial laser scans (TLSs), are measured. Previous approaches are reviewed, and two new methods are introduced in an attempt to standardize the process. The approaches are applied to a set of synthetic rockfall objects generated in the open-source software package Blender. Fifty rockfall events derived from sequential TLS monitoring in the White Canyon, British Columbia, Canada, are used to demonstrate the application of the proposed algorithms. This study illustrates that the method used to calculate the rockfall dimensions has a significant impact on how the shape of a rockfall object is classified. This has implications for rockfall modelling as the block shape is known to influence rockfall runout.
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Smith, Laura. "The poetics of restoring Glen Canyon: the ‘desert imagination’ of Ellen Meloy and Terry Tempest Williams." cultural geographies 25, no. 4 (April 2, 2018): 603–18. http://dx.doi.org/10.1177/1474474018762813.
Full textAbstract:
There has been a literary tradition supporting the restoration of Glen Canyon in southern Utah ever since construction began on Glen Canyon Dam in the late 1950s, and the canyons began to disappear behind the rising waters of Lake Powell. While some of Glen Canyon’s literary protagonists put forward a strong political and anarchical refrain for a ‘Glen Canyon restored’, this article considers those writers and texts that instead look to the power of appeals to emotion in defense of the desert. In particular, this article considers the evocative capacity of environmental writing to convey emotional and affective landscapes. This article examines the desert writings of Ellen Meloy and Terry Tempest Williams, and the ways in which they employ rhetoric, myth, story, motifs, metaphor, symbolism, and allegory to speak back to the environmental condition, and the ongoing call to restore Glen Canyon. Meloy’s and Williams’ works present individual testimonies molded by personal engagement, experience, and investigation in the desert – but also contribute to ecological and political discourse in the Glen.
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Krupp, E. C. "Crab Supernova Rock Art." Journal of Skyscape Archaeology 1, no. 2 (December 3, 2015): 167–97. http://dx.doi.org/10.1558/jsa.v1i2.28255.
Full textAbstract:
“Star” and crescent combinations in rock art in the American Southwest were first interpreted in 1955 as eyewitness depictions of the 1054 AD supernova explosion that produced the Crab nebula. While the Crab nebula is visible only telescopically, the event that generated it was brilliant, and for a time, only the sun and moon were brighter. Additional Crab supernova candidates in California and Southwest rock art were suggested 20 years later, and they included Chaco Canyon’s Penasco Blanco pictograph panel, which became the poster child for Crab supernova rock art and is now called “Supernova” on signage at the site. By 1979, a list of 21 Crab supernova rock art sites was assembled, and the inventory has continued to expand more slowly since then. This critical review of the supernova interpretation of star/crescent rock art, the product of 35 years of fieldwork, required an independent re-examination of all of the primary sites in person. That enterprise has already demonstrated that the Tenabo, New Mexico panel does not illustrate the Crab supernova and that the two Arizona sites on which the entire supernova rock art premise is based (White Mesa and “Navaho Canyon”) are unlikely records of the event. This detailed evaluation of the primary proposed star/crescent images indicates none is a satisfactory portrayal of the striking 1054 AD supernova.