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Sample records for tail baseplate central

  1. Baseplate assembly of phage Mu: Defining the conserved core components of contractile-tailed phages and related bacterial systems.

    Science.gov (United States)

    Büttner, Carina R; Wu, Yingzhou; Maxwell, Karen L; Davidson, Alan R

    2016-09-06

    Contractile phage tails are powerful cell puncturing nanomachines that have been co-opted by bacteria for self-defense against both bacteria and eukaryotic cells. The tail of phage T4 has long served as the paradigm for understanding contractile tail-like systems despite its greater complexity compared with other contractile-tailed phages. Here, we present a detailed investigation of the assembly of a "simple" contractile-tailed phage baseplate, that of Escherichia coli phage Mu. By coexpressing various combinations of putative Mu baseplate proteins, we defined the required components of this baseplate and delineated its assembly pathway. We show that the Mu baseplate is constructed through the independent assembly of wedges that are organized around a central hub complex. The Mu wedges are comprised of only three protein subunits rather than the seven found in the equivalent structure in T4. Through extensive bioinformatic analyses, we found that homologs of the essential components of the Mu baseplate can be identified in the majority of contractile-tailed phages and prophages. No T4-like prophages were identified. The conserved simple baseplate components were also found in contractile tail-derived bacterial apparatuses, such as type VI secretion systems, Photorhabdus virulence cassettes, and R-type tailocins. Our work highlights the evolutionary connections and similarities in the biochemical behavior of phage Mu wedge components and the TssF and TssG proteins of the type VI secretion system. In addition, we demonstrate the importance of the Mu baseplate as a model system for understanding bacterial phage tail-derived systems.

  2. Mutational analysis of two structural genes of the remperate lactococcal bacteriophage TP901-1 involved in tail length determination and baseplate assembly

    DEFF Research Database (Denmark)

    Pedersen, Margit; Østergaard, Solvej; Bresciani, José

    2000-01-01

    Two putative structural genes, orf tmp (tape measure protein) and orf bpp (baseplate protein), of the temperate lactococcal phage TP901-1 were examined by introduction of specific mutations in the prophage strain Lactococcus lactic ssp. cremoris 901-1. The adsorption efficiencies of the mutated...... of the TP901-1 tail and baseplate structure is presented. Author Keywords: Lactococcus bacteriophage; TP901-1; mutagenesis; structural genes; adsorption; tail protein; tape measure protein; baseplate protein...

  3. Mutational analysis of two structural genes of the remperate lactococcal bacteriophage TP901-1 involved in tail length determination and baseplate assembly

    DEFF Research Database (Denmark)

    Pedersen, Margit; Østergaard, Solvej; Bresciani, José

    2000-01-01

    Two putative structural genes, orf tmp (tape measure protein) and orf bpp (baseplate protein), of the temperate lactococcal phage TP901-1 were examined by introduction of specific mutations in the prophage strain Lactococcus lactic ssp. cremoris 901-1. The adsorption efficiencies of the mutated p...... of the TP901-1 tail and baseplate structure is presented. Author Keywords: Lactococcus bacteriophage; TP901-1; mutagenesis; structural genes; adsorption; tail protein; tape measure protein; baseplate protein...

  4. The Type VI Secretion TssEFGK-VgrG Phage-Like Baseplate Is Recruited to the TssJLM Membrane Complex via Multiple Contacts and Serves As Assembly Platform for Tail Tube/Sheath Polymerization.

    Directory of Open Access Journals (Sweden)

    Yannick R Brunet

    2015-10-01

    Full Text Available The Type VI secretion system (T6SS is a widespread weapon dedicated to the delivery of toxin proteins into eukaryotic and prokaryotic cells. The 13 T6SS subunits assemble a cytoplasmic contractile structure anchored to the cell envelope by a membrane-spanning complex. This structure is evolutionarily, structurally and functionally related to the tail of contractile bacteriophages. In bacteriophages, the tail assembles onto a protein complex, referred to as the baseplate, that not only serves as a platform during assembly of the tube and sheath, but also triggers the contraction of the sheath. Although progress has been made in understanding T6SS assembly and function, the composition of the T6SS baseplate remains mostly unknown. Here, we report that six T6SS proteins-TssA, TssE, TssF, TssG, TssK and VgrG-are required for proper assembly of the T6SS tail tube, and a complex between VgrG, TssE,-F and-G could be isolated. In addition, we demonstrate that TssF and TssG share limited sequence homologies with known phage components, and we report the interaction network between these subunits and other baseplate and tail components. In agreement with the baseplate being the assembly platform for the tail, fluorescence microscopy analyses of functional GFP-TssF and TssK-GFP fusion proteins show that these proteins assemble stable and static clusters on which the sheath polymerizes. Finally, we show that recruitment of the baseplate to the apparatus requires initial positioning of the membrane complex and contacts between TssG and the inner membrane TssM protein.

  5. Bacteriophage module reshuffling results in adaptive host range as exemplified by the baseplate model of listerial phage A118.

    Science.gov (United States)

    Cambillau, Christian

    2015-10-01

    Each phage infects its specific bacterial host strain through highly specific interactions between the baseplate-associated receptor binding protein (RBP) at the tip of the phage tail and the receptor at the host surface. Baseplates incorporate structural core modules, Dit and Tal, largely conserved among phages, and peripheral modules anchoring the RBPs. Exploiting structural information from the HHpred program and EM data from the Bielmann et al. (2015) paper, a molecular model of the A118 phage baseplate was generated from different building blocks. This model implies the occurrence of baseplate module reshuffling and suggests that listerial phage A118 may have been derived from lactococcal phage TP901-1 through host species exchange. With the increase of available viral module structures, modelling phage baseplates will become easier and more reliant, and will provide insightful information on the nature of the phage host receptor and its mode of recognition. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. The structure of gene product 6 of bacteriophage T4, the hinge-pin of the baseplate.

    Science.gov (United States)

    Aksyuk, Anastasia A; Leiman, Petr G; Shneider, Mikhail M; Mesyanzhinov, Vadim V; Rossmann, Michael G

    2009-06-10

    The baseplate of bacteriophage T4 is a multicomponent protein complex, which controls phage attachment to the host. It assembles from six wedges and a central hub. During infection the baseplate undergoes a large conformational change from a dome-shaped to a flat, star-shaped structure. We report the crystal structure of the C-terminal half of gene product (gp) 6 and investigate its motion with respect to the other proteins during the baseplate rearrangement. Six gp6 dimers interdigitate, forming a ring that maintains the integrity of the baseplate in both conformations. One baseplate wedge contains an N-terminal dimer of gp6, whereas neighboring wedges are tied together through the C-terminal dimer of gp6. The dimeric interactions are preserved throughout the rearrangement of the baseplate. However, the hinge angle between the N- and C-terminal parts of gp6 changes by approximately 15 degrees , accounting for a 10 A radial increase in the diameter of the gp6 ring.

  7. Topographic home ranges of white-tailed deer in the central Appalachians

    Science.gov (United States)

    Tyler A. Campbell; Benjamin R. Laseter; W. Mark Ford; Karl V. Miller

    2004-01-01

    Planimetric comparisons of home range sizes of white-tailed deer (Odocoileus virginianus Zimmermann) from across their range may not be appropriate due to regional differences in topography. We compare seasonal topographic diversity between male and female white-tailed deer home ranges in the central Appalachians using percent increase from...

  8. Dynamic Characteristics and Model for Centralization Reaction of Acidic Tailings From Heap Leaching of Uranium Ore

    International Nuclear Information System (INIS)

    Ding Dexin; Liu Yulong; Li Guangyue; Wang Youtuan

    2010-01-01

    Centralization tests were carried out on acidic tailings from heap leaching of uranium ore by using CaO, NaOH and NH 4 OH. The variations of pH with time were measured for the three centralization systems and the dynamic models for the systems were set up by regressing the measured data. The centralization process consists of the fast reaction phase representing the reaction between the centralization agent and the acid on the surface of the tailing's particles and the slow diffusion-reaction phase representing the diffusion-reaction between the centralization agent and the acid within the tailing's particles. The non-linear coupling and feedback function model for the diffusion-reaction of the centralization agent can reflect the process and mode of the centralization reaction. There is a non-linear oscillation in the variation of pH within the centralization systems. The dynamic model for the tailing's centralization reaction can fit the pH variation within the centralization systems. (authors)

  9. Evidence for a link between tail biting and central monoamine metabolism in pigs (Sus scrofa domestica).

    Science.gov (United States)

    Valros, Anna; Palander, Pälvi; Heinonen, Mari; Munsterhjelm, Camilla; Brunberg, Emma; Keeling, Linda; Piepponen, Petteri

    2015-05-01

    Tail biting in pigs is a major welfare problem within the swine industry. Even though there is plenty of information on housing and management-related risk factors, the biological bases of this behavioral problem are poorly understood. The aim of this study was to investigate a possible link between tail biting, based on behavioral recordings of pigs during an ongoing outbreak, and certain neurotransmitters in different brain regions of these pigs. We used a total of 33 pigs at a farm with a long-standing problem of tail biting. Three equally big behavioral phenotypic groups, balanced for gender and age were selected, the data thus consisting of 11 trios of pigs. Two of the pigs in each trio originated from the same pen: one tail biter (TB) and one tail biting victim (V). A control (C) pig was selected from a pen without significant tail biting in the same farm room. We found an effect of tail biting behavioral phenotype on the metabolism of serotonin and dopamine, with a tendency for a higher 5-HIAA level in the prefrontal cortex (PFC) of TB compared to the other groups, while V pigs showed changes in both serotonin and dopamine metabolism in the striatum (ST) and limbic cortex (LC). Trp:BCAA and Trp:LNAA correlated positively with serotonin and 5-HIAA in the PFC, but only in TB pigs. Furthermore, in both ST and LC, several of the neurotransmitters and their metabolites correlated positively with the frequency of bites received by the pig. This is the first study indicating a link between brain neurotransmission and tail biting behavior in pigs with TB pigs showing a tendency for increased PFC serotonin metabolism and V pigs showing several changes in central dopamine and serotonin metabolism in their ST and LC, possibly due to the acute stress caused by being bitten. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Structure and molecular assignment of lactococcal phage TP901-1 baseplate

    DEFF Research Database (Denmark)

    Bebeacua, Cecilia; Bron, Patrick; Lai, Livia

    2010-01-01

    P335 lactococcal phages infect the Gram(+) bacterium Lactococcus lactis using a large multiprotein complex located at the distal part of the tail and termed baseplate (BP). The BP harbors the receptor-binding proteins (RBPs), which allow the specific recognition of saccharidic receptors localized...... on the host cell surface. We report here the electron microscopic structure of the phage TP901-1 wild-type BP as well as those of two mutants bppL (-) and bppU(-), lacking BppL (the RBPs) or both peripheral BP components (BppL and BppU), respectively. We also achieved an electron microscopic reconstruction...... by ORF46 (Dit) hexamers, at its proximal end, and a ORF47 (Tal) trimer at its distal extremity. A total of 54 BppLs (18 RBPs) are thus available to mediate host anchoring with a large apparent avidity. TP901-1 BP exhibits an infection-ready conformation and differs strikingly from the lactococcal phage p...

  11. The Tail-Elicited Tail Withdrawal Reflex of "Aplysia" Is Mediated Centrally at Tail Sensory-Motor Synapses and Exhibits Sensitization across Multiple Temporal Domains

    Science.gov (United States)

    Philips, Gary T.; Sherff, Carolyn M.; Menges, Steven A.; Carew, Thomas J.

    2011-01-01

    The defensive withdrawal reflexes of "Aplysia californica" have provided powerful behavioral systems for studying the cellular and molecular basis of memory formation. Among these reflexes the (T-TWR) has been especially useful. In vitro studies examining the monosynaptic circuit for the T-TWR, the tail sensory-motor (SN-MN) synapses, have…

  12. Striped-tailed Yellow-finch nesting success in abandoned mining pits from central Brazilian cerrado

    Directory of Open Access Journals (Sweden)

    DT. Gressler

    Full Text Available Suitability of degraded areas as breeding habitats can be tested through assessment of nest predation rates. In this study we estimated nest success in relation to several potential predictors of nest survival in the Stripe-tailed Yellow-finch (Sicalis citrina breeding in abandoned mining pits at Brasília National Park. We monitored 73 nests during the 2007-breeding season. Predation was the main cause of nest failure (n = 48, 66%; while six nests were abandoned (8% and 19 nests produced young (26%. Mayfield’s daily survival rates and nest success were 0.94 and 23%, respectively. Our results from nest survival models on program MARK indicated that daily survival rates increase linearly towards the end of the breeding season and decrease as nests aged. None of the nest individual covariates we tested - nest height, nest size, nest substrate, and edge effect - were important predictors of nest survival; however, nests placed on the most common plant tended to have higher survival probabilities. Also, there was no observer effect on daily survival rates. Our study suggests that abandoned mining pits may be suitable alternative breeding habitats for Striped-tailed Yellow-finches since nest survival rates were similar to other studies in the central cerrado region.

  13. Disposal and close of major non-conformity of crack of concrete baseplate

    International Nuclear Information System (INIS)

    Zhang Zhihua; Liu Hangan; Qian Dazhi; Huang Hongwen; Deng Yue; Zhou Wei; Yang Guoqing

    2009-01-01

    In terms of the quality assurance and control for nuclear engineering construction, this paper introduced the determination, origin analysis, remediation, disposal and close of the major non conformity of crack of concrete baseplate. (authors)

  14. Reverse total shoulder glenoid baseplate stability with superior glenoid bone loss.

    Science.gov (United States)

    Martin, Elise J; Duquin, Thomas R; Ehrensberger, Mark T

    2017-10-01

    Superior wear of the glenoid bone is common in patients with rotator cuff arthropathy. This can become a treatment challenge for patients who require shoulder arthroplasty. In reverse shoulder arthroplasty (RSA), glenoid bone loss may affect the stability of baseplate fixation. The primary purpose of this biomechanical laboratory study was to assess the initial fixation stability of RSA glenosphere baseplates in the presence of variable amounts of superior glenoid bone loss. High-density solid rigid polyurethane foam (30 pounds/cubic foot) was machined to model the glenoid with variable superior defects that provided different levels of support (100%, 90%, 75%, and 50%) for the glenosphere baseplate. The samples were cyclically loaded (0-750 N at 1 Hz for 5000 cycles) at a 60° glenohumeral angle. The micromotion and migration of the baseplate were calculated from displacement data captured during the loading tests with an array of 3 linear variable differential transformers mounted around the baseplate. Micromotion was significantly greater in samples with 50% defects compared with those with smaller defects. Migration was significantly greater after testing for all defect sizes. Initial fixation of RSA glenosphere baseplates was significantly reduced in models with 50% bone loss on the superior edge compared with models with less bone loss in this high-density bone foam model. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  15. Predicting intensity of white-tailed deer herbivory in the Central Appalachian Mountains

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    Kniowski, Andrew B.; Ford, W. Mark

    2018-01-01

    In eastern North America, white-tailed deer (Odocoileus virginianus) can have profound influences on forest biodiversity and forest successional processes. Moderate to high deer populations in the central Appalachians have resulted in lower forest biodiversity. Legacy effects in some areas persist even following deer population reductions or declines. This has prompted managers to consider deer population management goals in light of policies designed to support conservation of biodiversity and forest regeneration while continuing to support ample recreational hunting opportunities. However, despite known relationships between herbivory intensity and biodiversity impact, little information exists on the predictability of herbivory intensity across the varied and spatially diverse habitat conditions of the central Appalachians. We examined the predictability of browsing rates across central Appalachian landscapes at four environmental scales: vegetative community characteristics, physical environment, habitat configuration, and local human and deer population demographics. In an information-theoretic approach, we found that a model fitting the number of stems browsed relative to local vegetation characteristics received most (62%) of the overall support of all tested models assessing herbivory impact. Our data suggest that deer herbivory responded most predictably to differences in vegetation quantity and type. No other spatial factors or demographic factors consistently affected browsing intensity. Because herbivory, vegetation communities, and productivity vary spatially, we suggest that effective broad-scale herbivory impact assessment should include spatially-balanced vegetation monitoring that accounts for regional differences in deer forage preference. Effective monitoring is necessary to avoid biodiversity impacts and deleterious changes in vegetation community composition that are difficult to reverse and/or may not be detected using traditional deer

  16. The annual pattern of sap flow in tow Eucalyptus species established in the vicinity of gold-mine tailings dams in central South Africa

    CSIR Research Space (South Africa)

    Dye, P

    2016-08-01

    Full Text Available Several hundred mine tailings dams occur in the Witwatersrand Basin Goldfields in central South Africa. Seepage of acid mine drainage (AMD) from these unlined structures is widespread, and a variety of contaminants is released into soil...

  17. Seasonal food selection and digestibility by tame white-tailed deer in central Maine

    Science.gov (United States)

    Hewlette S. Crawford

    1982-01-01

    Seasonal food selection and digestibility by tame white-tailed deer (Odocoileus virginianus) were studied in the white pine (Pinus strobus)–Canada hemlock (Tsuga canadensis) and lowland conifer types, areas representative of important deer habitat in the northeastern United States. Deer selected highly...

  18. Habitat use and foraging patterns of molting male Long-tailed Ducks in lagoons of the central Beaufort Sea, Alaska

    Science.gov (United States)

    Flint, Paul L.; Reed, John; Deborah Lacroix,; Richard Lanctot,

    2016-01-01

    From mid-July through September, 10 000 to 30 000 Long-tailed Ducks (Clangula hyemalis) use the lagoon systems of the central Beaufort Sea for remigial molt. Little is known about their foraging behavior and patterns of habitat use during this flightless period. We used radio transmitters to track male Long-tailed Ducks through the molt period from 2000 to 2002 in three lagoons: one adjacent to industrial oil field development and activity and two in areas without industrial activity. We found that an index to time spent foraging generally increased through the molt period. Foraging, habitat use, and home range size showed similar patterns, but those patterns were highly variable among lagoons and across years. Even with continuous daylight during the study period, birds tended to use offshore areas during the day for feeding and roosted in protected nearshore waters at night. We suspect that variability in behaviors associated with foraging, habitat use, and home range size are likely influenced by availability of invertebrate prey. Proximity to oil field activity did not appear to affect foraging behaviors of molting Long-tailed Ducks.

  19. Tail Behavior of the Central European Stock Markets during the Financial Crisis

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Vácha, Lukáš; Vošvrda, Miloslav

    2010-01-01

    Roč. 2010, č. 4 (2010), s. 1-17 R&D Projects: GA ČR GP402/08/P207; GA ČR GD402/09/H045; GA ČR GA402/09/0965 Institutional research plan: CEZ:AV0Z10750506 Keywords : financial crisis * tail behavior * stock market s * stable probability distribution Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2010/E/barunik-0341829.pdf

  20. Tail Behavior of the Central European Stock Markets during the Financial Crisis

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Vácha, Lukáš; Vošvrda, Miloslav

    2010-01-01

    Roč. 4, č. 3 (2010), s. 282-294 ISSN 1802-4696 R&D Projects: GA ČR GA402/09/0965; GA ČR GD402/09/H045; GA ČR GP402/08/P207 Grant - others:GA MŠk(CZ) 0021620840 Institutional research plan: CEZ:AV0Z10750506 Keywords : Financial crisis * tail behavior * stock markets * stable probability distribution Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2010/E/barunik-0349713.pdf

  1. Habitat selection of a declining white-tailed deer herd in the central Black Hills, South Dakota and Wyoming

    Science.gov (United States)

    Deperno, Christopher Shannon

    Habitat selection, survival rates, the Black Hills National Forest Habitat Capability Model (HABCAP), and the USDA Forest Service Geographic Information System (GIS) data base were evaluated for a declining white-tailed deer (Odocoileus virginianus dacotensis) herd in the central Black Hills of South Dakota and Wyoming. From July 1993 through July 1996, 73 adult and yearling female and 12 adult and yearling male white-tailed deer were radiocollared and visually monitored. Habitat information was collected at 4,662 white-tailed deer locations and 1,087 random locations. Natural mortality (71%) was the primary cause of female mortality, followed by harvest (22.5%) and accidental causes (6.5%). More females died in spring (53.2%) than in fall (22.6%), winter (14.5%), or summer (9.7%). Male mortality resulted from hunting in fall (66.7%) and natural causes in spring (33.3%). Survival rates for all deer by year were 62.1% in 1993, 51.1% in 1994, 56.4% in 1995, and 53.9% in 1996 and were similar (P = 0.691) across years. During winter, white-tailed deer selected ponderosa pine- (Pinus ponderosa ) deciduous and burned pine cover types. Overstory-understory habitats selected included pine/grass-forb, pine/bearberry (Arctostaphylos uva-ursi), pine/snowberry (Symphoricarpos albus), burned pine/grass-forb, and pine/shrub habitats. Structural stages selected included sapling-pole pine stands with >70% canopy cover, burned pine sapling-pole and saw-timber stands with 40% canopy cover and all sapling-pole pine structural stages; sapling-pole stands with >70% canopy cover received the greatest use. White-tailed deer primarily fed in pine saw-timber structural stage with less than 40% canopy cover. Overall, selected habitats contained lower amounts of grass/forb, shrubs, and litter than random locations. Male and female deer generally bedded in areas that were characterized by greater horizontal cover than feeding and random sites. When feeding and bedding sites were combined

  2. Current Total Knee Designs: Does Baseplate Roughness or Locking Mechanism Design Affect Polyethylene Backside Wear?

    Science.gov (United States)

    Sisko, Zachary W; Teeter, Matthew G; Lanting, Brent A; Howard, James L; McCalden, Richard W; Naudie, Douglas D; MacDonald, Steven J; Vasarhelyi, Edward M

    2017-12-01

    Tibial baseplate roughness and polyethylene-insert micromotion resulting from locking-mechanism loosening can lead to polyethylene backside wear in TKAs. However, many retrieval studies examining these variables have evaluated only older TKA implant designs. We used implant-retrieval analysis to examine if there were differences in: (1) backside damage scores, (2) backside damage modes, and (3) backside linear wear rates in five TKA implant designs owing to differing baseplate surface roughness and locking mechanisms. Additionally, we examined if (4) patient demographics influence backside damage and wear. Five TKA implant models (four modern and one historical design) were selected with different tibial baseplate and/or locking mechanism designs. Six tibial inserts retrieved at the time of revision from each TKA model were matched for time in vivo, age of the patient at TKA revision, BMI, sex, revision number, and revision reason. Each insert backside was analyzed for: (1) visual total damage score and (2) individual visual damage modes, both by two observers and with an intraclass correlation coefficient of 0.66 (95% CI, 0.39-0.92), and (3) linear wear rate measured by micro-CT. Median primary outcomes were compared among the five designs. For our given sample size among five groups we could detect with 80% power a 10-point difference in damage score and an 0.11-mm per year difference in wear rate. The polished tibial design with a partial peripheral capture locking mechanism and anterior constraint showed a lower total damage score compared with the nonpolished tibial design with only a complete peripheral-rim locking mechanism (median, 12.5; range, 9.5-18.0; 95% CI, 9.58-16.42 versus median, 22.3; range, 15.5-27.0; 95% CI, 17.5-26.5; p = 0.019). The polished baseplate with a tongue-in-groove locking mechanism showed more abrasions than the nonpolished baseplate with a peripheral-rim capture and antirotational island (median, 7.25; range, 0.5-8.0; 95% CI, 2

  3. Effects of tibial baseplate shape on rotational alignment in total knee arthroplasty: three-dimensional surgical simulation using osteoarthritis knees.

    Science.gov (United States)

    Ma, Yuan; Mizu-Uchi, Hideki; Okazaki, Ken; Ushio, Tetsuro; Murakami, Koji; Hamai, Satoshi; Akasaki, Yukio; Nakashima, Yasuharu

    2018-01-01

    Placement of tibial component is expected to fulfill both maximum surface coverage and recommended anterior-posterior (AP) alignment in total knee arthroplasty (TKA). The purpose of this study is to evaluate the effect of the tibial baseplate shape on AP axis. Virtual surgery of TKA was performed with three-dimensional bone models reconstructed from 77 osteoarthritis varus knees. Two differently designed tibial baseplates, symmetrically and anatomically, were set to the cut surface under posterior slopes of 0°, 3°, and 7°. The AP axes were defined by connecting the geometrical center of the cut surface with the medial edge (axis MED) and medial 1/3 (axis 1/3MED) of patella tendon attachment. We evaluated the overhang rates as well as the most fitting AP axis which passes through the geometric center. Overhang rates when aligned to axis MED were 12-25% for the symmetrical-type group and 13-22% for the anatomical-type group. Overhang rates when aligned to axis 1/3MED were 42-48% for the symmetrical-type group and 3-7% for the anatomical-type group. The most fitting AP axis of tibial baseplate was located 2.5° external to axis MED for the symmetrical-type group and around 3.3° internal to axis 1/3MED for the anatomical-type group. Symmetrically or anatomically designed tibial baseplates have their own favored AP axis and specific performance on coverage. When aligned to axis 1/3MED, anatomically designed tibial baseplates will effectively lower the mismatch rates compared to a symmetrically designed tibial baseplate. Orthopaedic surgeons are expected to place the tibial components to the cut surface during TKA with full understanding of the features between different baseplate designs, AP axes, and posterior slopes for an ideal tibial rotational position.

  4. Spatial factors of white-tailed deer herbivory assessment in the central Appalachian Mountains.

    Science.gov (United States)

    Kniowski, Andrew B; Ford, W Mark

    2018-03-25

    Because moderate to over-abundant white-tailed deer (Odocoileus virginianus) herbivory impacts biodiversity and can alter community function, ecological benchmarks of herbivory impact are needed to assess deer impacts. We evaluated spatial patterns of deer herbivory and their relation to herbivory assessment by evaluating woody vegetation along 20 transects at each of 30 sites spread across a wide range of deer herd densities and vegetative condition throughout the biodiverse Appalachian Mountains of Virginia, USA. Surprisingly, herbivory patterns and the availability of woody forage generally were unchanged among physiographic regions and land use diversity classes. However, some relationships between browsing pattern and vegetation varied with scale. The total quantity of vegetation browsed on a given site and at the transect scale were related positively to the availability of forage, as the proportion of stems browsed decreased as stem density increased. However, this was only true when all stems were considered equally. When stem densities by species were weighted for deer preference, the proportion of stems browsed had no relationship or increased with stem density. Compared to the value from all transects sampled, on average, the mean of ≥ 3 transects within a site was within 0.1 of the browsing ratio and stem densities were within 0.5 stems m -2 . Our results suggest that one transect per square kilometer with a minimum of three transects may be sufficient for most browsing intensity survey requirements to assess herbivory impacts in the Appalachian region of Virginia. Still, inclusion of spatial factors to help partition variation of deer herbivory potentially may allow for improved precision and accuracy in the design of field herbivory impact assessment methods and improve their application across various landscape contexts.

  5. Theory of Anisotropic Circular Dichroism of Excitonically Coupled Systems: Application to the Baseplate of Green Sulfur Bacteria.

    Science.gov (United States)

    Lindorfer, Dominik; Renger, Thomas

    2018-03-02

    A simple exciton theory for the description of anisotropic circular dichroism (ACD) spectra of multichromophoric systems is presented that is expected to be of general use for the analysis of structure-function relationships of molecular aggregates such as photosynthetic light-harvesting antennae. The theory is applied to the baseplate of green sulfur bacteria. It is demonstrated that only the combined analysis of ACD and circular dichroism (CD) spectra for the present baseplate bacteriochlorophyll (BChl) a dimer allows for an unambiguous determination of the parameters of the exciton Hamiltonian from experimental data. The analysis of experimental absorption and linear dichroism spectra suggests that either the NMR structure has to be refined or in addition to the dimers seen in the NMR structure and in the CD and ACD spectra, BChl a monomers are present in the baseplate carotenosome sample. A refined dimer structure is presented, explaining all four optical spectra.

  6. Calamitic Smectic A-Polar Smectic APA Transition Observed in Bent Molecules with Large Bent-Angle Central Core of 4,6-Dichlorobenzene and Alkylthio Terminal Tail

    Science.gov (United States)

    Nguyen, Ha; Kang, Sungmin; Tokita, Masatoshi; Watanabe, Junji

    2011-07-01

    New homologs of bent molecules with a large bent-angle central core of 4,6-dichloro benzene and an alkylthio terminal tail have been synthesized. Although the corresponding alkoxy-tail homologs show only the calamitic phases because of its large bent angles around 160°, the new homologs with an alkylthio tail exhibit the antiferroelectric smectic APA (SmAPA) banana phase that is transformed on cooling from the calamitic smectic A (SmA) phase. The biaxial polar packing of bent molecules in the SmAPA phase is considered to arise from the hindered rotation around the molecular long axis due to the expansion of the mesophase temperatures to a lower temperature region. This study indicates that the bent molecules, even with a large bent angle, have the potential to form a switchable banana phase with a remarkable decrease in its phase temperature range to around 60 °C.

  7. Exciton description of chlorosome to baseplate excitation energy transfer in filamentous anoxygenic phototrophs and green sulfur bacteria.

    Science.gov (United States)

    Linnanto, Juha M; Korppi-Tommola, Jouko E I

    2013-09-26

    A description of intra-chlorosome and from chlorosome to baseplate excitation energy transfer in green sulfur bacteria and in filamentous anoxygenic phototrophs is presented. Various shapes and sizes, single and multiwalled tubes, cylindrical spirals and lamellae of the antenna elements mimicking pigment organization in chlorosomes were generated by using molecular mechanics calculations, and the absorption, LD, and CD spectra of these were predicted by using exciton theory. Calculated absorption and LD spectra were similar for all modeled antenna structures; on the contrary, CD spectra turned out to be sensitive to the size and pigment orientations in the antenna. It was observed that, bringing two tubular antennae at close enough interaction distance, the exciton density of the lowest energy state became localized on pigments facing each other in the antenna dimer. Calculations predicted for stacked tubular antenna elements extremely fast, faster than 500 fs, intra-chlorosome energy transfer toward the baseplates in the direction perpendicular to the chlorosome long axis. Downhill excitation energy transfer according to our model is driven by interactions of the antennae with their immediate surroundings. Energy transfer from the chlorosome to the baseplate, consisting of 2D lattices of monomeric and dimeric bacteriochlorophyll a molecules, was predicted to occur in 5-15 ps, in agreement with experimental findings. Advancement of excitation through a double tube antenna stack, a model for antenna element organization in chlorosomes of green sulfur bacteria, to a monomeric baseplate was visualized in space and in time.

  8. In situ high-resolution structure of the baseplate antenna complex in Chlorobaculum tepidum

    DEFF Research Database (Denmark)

    Nielsen, Jakob Toudahl; Kulminskaya, Natalia V.; Bjerring, Morten

    2016-01-01

    Photosynthetic antenna systems enable organisms harvesting light and transfer the energy to the photosynthetic reaction centre, where the conversion to chemical energy takes place. One of the most complex antenna systems, the chlorosome, found in the photosynthetic green sulfur bacterium...... of highly symmetric oligomeric structures. We show that the baseplate is composed of rods of repeated dimers of the strongly amphipathic CsmA with pigments sandwiched within the dimer at the hydrophobic side of the helix....

  9. The Baseplate of Lactobacillus delbrueckii Bacteriophage Ld17 Harbors a Glycerophosphodiesterase.

    Science.gov (United States)

    Cornelissen, Anneleen; Sadovskaya, Irina; Vinogradov, Evgeny; Blangy, Stéphanie; Spinelli, Silvia; Casey, Eoghan; Mahony, Jennifer; Noben, Jean-Paul; Dal Bello, Fabio; Cambillau, Christian; van Sinderen, Douwe

    2016-08-05

    Glycerophosphodiester phosphodiesterases (GDPDs; EC 3.1.4.46) typically hydrolyze glycerophosphodiesters to sn-glycerol 3-phosphate (Gro3P) and their corresponding alcohol during patho/physiological processes in bacteria and eukaryotes. GDPD(-like) domains were identified in the structural particle of bacterial viruses (bacteriophages) specifically infecting Gram-positive bacteria. The GDPD of phage 17 (Ld17; GDPDLd17), representative of the group b Lactobacillus delbrueckii subsp. bulgaricus (Ldb)-infecting bacteriophages, was shown to hydrolyze, besides the simple glycerophosphodiester, two complex surface-associated carbohydrates of the Ldb17 cell envelope: the Gro3P decoration of the major surface polysaccharide d-galactan and the oligo(glycerol phosphate) backbone of the partially glycosylated cell wall teichoic acid, a minor Ldb17 cell envelope component. Degradation of cell wall teichoic acid occurs according to an exolytic mechanism, and Gro3P substitution is presumed to be inhibitory for GDPDLd17 activity. The presence of the GDPDLd17 homotrimer in the viral baseplate structure involved in phage-host interaction together with the dependence of native GDPD activity, adsorption, and efficiency of plating of Ca(2+) ions supports a role for GDPDLd17 activity during phage adsorption and/or phage genome injection. In contrast to GDPDLd17, we could not identify any enzymatic activity for the GDPD-like domain in the neck passage structure of phage 340, a 936-type Lactococcus lactis subsp. lactis bacteriophage. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Frost evolution in tailings

    International Nuclear Information System (INIS)

    1991-04-01

    A review was carried out on the physical and thermal mechanisms of permafrost evaluation in soils and uranium tailings. The primary mechanism controlling permafrost evolution is conductive heat transfer with the latent heat of fusion of water being liberated as phase change occurs. Depending on the soil properties and freezing rate, pore water can be expelled from the frost front or pore water can migrate towards the frost front. Solute redistribution may occur as the frost front penetrates into the soil. The rate of frost penetration is a function of the thermal properties of the tailings and the climatic conditions. Computer modelling programmes capable of modelling permafrost evolution were reviewed. The GEOTHERM programme was selected as being the most appropriate for this study. The GEOTHERM programme uses the finite element method of thermal analysis. The ground surface temperature is determined by solving the energy balance equations a the ground surface. The GEOTHERM programme was used to simulate the permafrost evolution in the Key Lake Mine tailings located in north central Saskatchewan. The analyses indicated that the existing frozen zones in the tailing pond will eventually thaw if an average snow depth covers the tailings. Hundreds of years are required to thaw the tailings. If minimal snow cover is present the extent of the frozen zone in the tailings will increase

  11. Usefulness of Non-coplanar Helical Tomotherapy Using Variable Axis Baseplate

    International Nuclear Information System (INIS)

    Ha, Jin Sook; Chung, Yoon Sun; Lee, Ik Jae; Shin, Dong Bong; Kim, Jong Dae; Kim, Sei Joon; Jeon, Mi Jin; Chok, Yoon Jin; Kim, Ki Kwang; Lee, Seul Bee

    2011-01-01

    Helical Tomotherapy allows only coplanar beam delivery because it does not allow couch rotation. We investigated a method to introduce non-coplanar beam by tilting a patient's head for Tomotherapy. The aim of this study was to compare intrafractional movement during Tomotherapy between coplanar and non-coplanar patient's setup. Helical Tomotherapy was used for treating eight patients with intracranial tumor. The subjects were divided into three groups: one group (coplanar) of 2 patients who lay on S-plate with supine position and wore thermoplastic mask for immobilizing the head, second group (non-coplanar) of 3 patients who lay on S-plate with supine position and whose head was tilted with Variable Axis Baseplate and wore thermoplastic mask, and third group (non-coplanar plus mouthpiece) of 3 patients whose head was tilted and wore a mouthpiece immobilization device and thermoplastic mask. The patients were treated with Tomotherapy after treatment planning with Tomotherapy Planning System. Megavoltage computed tomography (MVCT) was performed before and after treatment, and the intrafractional error was measured with lateral(X), longitudinal(Y), vertical(Z) direction movements and vector (√x 2 +√y 2 +√z 2 ) value for assessing overall movement. Intrafractional error was compared among three groups by taking the error of MVCT taken after the treatment. As the correction values (X, Y, Z) between MVCT image taken after treatment and CT-simulation image are close to zero, the patient movement is small. When the mean values of movement of each direction for non-coplanar setup were compared with coplanar setup group, X-axis movement was decreased by 13%, but Y-axis and Z-axis movement were increased by 109% and 88%, respectively. Movements of Y-axis and Z-axis with non-coplanar setup were relatively greater than that of X-axis since a tilted head tended to slip down. The mean of X-axis movement of the group who used a mouthpiece was greater by 9.4% than the group

  12. Usefulness of Non-coplanar Helical Tomotherapy Using Variable Axis Baseplate

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Jin Sook; Chung, Yoon Sun; Lee, Ik Jae; Shin, Dong Bong; Kim, Jong Dae; Kim, Sei Joon; Jeon, Mi Jin; Chok, Yoon Jin; Kim, Ki Kwang; Lee, Seul Bee [Dept. of Radiation Oncology, Gangnam Severance Hospital, Seoul (Korea, Republic of)

    2011-03-15

    Helical Tomotherapy allows only coplanar beam delivery because it does not allow couch rotation. We investigated a method to introduce non-coplanar beam by tilting a patient's head for Tomotherapy. The aim of this study was to compare intrafractional movement during Tomotherapy between coplanar and non-coplanar patient's setup. Helical Tomotherapy was used for treating eight patients with intracranial tumor. The subjects were divided into three groups: one group (coplanar) of 2 patients who lay on S-plate with supine position and wore thermoplastic mask for immobilizing the head, second group (non-coplanar) of 3 patients who lay on S-plate with supine position and whose head was tilted with Variable Axis Baseplate and wore thermoplastic mask, and third group (non-coplanar plus mouthpiece) of 3 patients whose head was tilted and wore a mouthpiece immobilization device and thermoplastic mask. The patients were treated with Tomotherapy after treatment planning with Tomotherapy Planning System. Megavoltage computed tomography (MVCT) was performed before and after treatment, and the intrafractional error was measured with lateral(X), longitudinal(Y), vertical(Z) direction movements and vector ({radical}x{sup 2}+{radical}y{sup 2}+{radical}z{sup 2}) value for assessing overall movement. Intrafractional error was compared among three groups by taking the error of MVCT taken after the treatment. As the correction values (X, Y, Z) between MVCT image taken after treatment and CT-simulation image are close to zero, the patient movement is small. When the mean values of movement of each direction for non-coplanar setup were compared with coplanar setup group, X-axis movement was decreased by 13%, but Y-axis and Z-axis movement were increased by 109% and 88%, respectively. Movements of Y-axis and Z-axis with non-coplanar setup were relatively greater than that of X-axis since a tilted head tended to slip down. The mean of X-axis movement of the group who used a

  13. A multicenter, prospective, clinical trial evaluating a novel adhesive baseplate (Provox StabiliBase) for peristomal attachment of postlaryngectomy pulmonary and voice rehabilitation devices

    NARCIS (Netherlands)

    Hilgers, Frans J. M.; Dirven, Richard; Wouters, Yannick; Jacobi, Irene; Marres, Henri A. M.; van den Brekel, Michiel W. M.

    2012-01-01

    Objectives/Hypothesis: Assessment of a novel adhesive baseplate (Provox StabiliBase) for heat and moisture exchanger (HME) and/or automatic speaking valve (ASV) application. Study Design: Prospective, clinical, multicenter trial. Methods: This was a trial in laryngectomized patients comparing their

  14. A multicenter, prospective, clinical trial evaluating a novel adhesive baseplate (Provox StabiliBase) for peristomal attachment of postlaryngectomy pulmonary and voice rehabilitation devices

    NARCIS (Netherlands)

    Hilgers, F.J.M.; Dirven, R.; Wouters, Y.; Jacobi, I.; Marres, H.A.M.; Brekel, M.W. van den

    2012-01-01

    OBJECTIVES/HYPOTHESIS: Assessment of a novel adhesive baseplate (Provox StabiliBase) for heat and moisture exchanger (HME) and/or automatic speaking valve (ASV) application. STUDY DESIGN: Prospective, clinical, multicenter trial. METHODS: This was a trial in laryngectomized patients comparing their

  15. The thick-bedded tail of turbidite thickness distribution as a proxy for flow confinement: Examples from tertiary basins of central and northern Apennines (Italy)

    Science.gov (United States)

    Marini, Mattia; Felletti, Fabrizio; Milli, Salvatore; Patacci, Marco

    2016-07-01

    This study reviews the thickness statistics of non-channelized turbidites from four tertiary basins of Central-Northern Apennines (Italy), where bed geometry and sedimentary character have been previously assessed. Though very different in terms of size and, arguably, character of feeder system, these basins share a common stratigraphic evolution consisting in transition from an early ponded to a late unconfined setting of deposition. Based on comparison of thickness subsets from diverse locations and stratigraphic heights within the studied turbidite fills, this paper seeks to answer the following questions: i) how data collection procedures and field operational constraints (e.g. measure location, outcrop quality, use of thicknesses data from single vs. multiple correlative sections, stratigraphic thickness of the study interval) can affect statistics of sample data? ii) how depositional controls of confined vs. unconfined turbidite basins can result in different thickness-frequency distributions?; and iii) is there in thickness statistics a 'flow confinement' signature which can be used to distinguish between confined and unconfined turbidites? Results suggest that: i) best practices of data collection are crucial to a meaningful interpretation of sample data statistics, especially in presence of stratigraphic and spatial trends of turbidite bed thickness; ii) a systematic bias against cm-thick Tcd Bouma sequence turbidites exists in sample data, which can result in the low-end tail of empirical thickness-frequency distributions to depart significantly from the actual distribution of turbidite thickness; and iii) thickness statistics of beds starting with a basal Ta/Tb Bouma division bear a coherent relationship to the transition from ponded to unconfined depositional settings, consisting in reduction of variance and mean and, consequently, parameters, or even type, of best fit model distribution. This research highlights the role of flow stripping, sediment by

  16. Temporal variability of radon in a remediated tailing of uranium ore processing – the case of Urgeiriça (central Portugal)

    International Nuclear Information System (INIS)

    Barbosa, S.M.; Lopes, F.; Correia, A.D.; Barbosa, S.; Pereira, A.C.; Neves, L.F.

    2015-01-01

    Radon monitoring at different levels of the cover of the Urgeiriça tailings shows that the sealing is effective and performing as desired in terms of containing the strongly radioactive waste resulting from uranium ore processing. However, the analysis of the time series of radon concentration shows a very complex temporal structure, particularly at depth, including very large and fast variations from a few tens of kBq m −3 to more than a million kBq m −3 in less than one day. The diurnal variability is strongly asymmetric, peaking at 18 h/19 h and decreasing very fast around 21 h/22 h. The analysis is performed for summer and for a period with no rain in order to avoid the potential influence of precipitation and related environmental conditions on the radon variability. Analysis of ancillary measurements of temperature, relative humidity, wind speed and wind direction, as well as atmospheric pressure reanalysis data shows that the daily averaged radon concentration in the taillings material is anti-correlated with the atmospheric pressure and that the diurnal amplitude is associated with the magnitude of atmospheric pressure daily oscillations. - Highlights: • The temporal variability of radon at the Urgeiriça tailing is examined. • The cover of the tailing is effective in containing the strongly radioactive waste. • Radon concentration varies with depth and exhibits very large sub-daily variations. • The daily variability is strongly asymmetric and non-stationary. • Apparent influence of atmospheric pressure on radon concentration patterns

  17. Distribution of eastern equine encephalomyelitis viral protein and nucleic acid within central nervous tissue lesions in white-tailed deer (Odocoileus virginianus).

    Science.gov (United States)

    Kiupel, M; Fitzgerald, S D; Pennick, K E; Cooley, T M; O'Brien, D J; Bolin, S R; Maes, R K; Del Piero, F

    2013-11-01

    An outbreak of eastern equine encephalomyelitis (EEE) occurred in Michigan free-ranging white-tailed deer (Odocoileus virginianus) during late summer and fall of 2005. Brain tissue from 7 deer with EEE, as confirmed by reverse transcriptase polymerase chain reaction, was studied. Detailed microscopic examination, indirect immunohistochemistry (IHC), and in situ hybridization (ISH) were used to characterize the lesions and distribution of the EEE virus within the brain. The main lesion in all 7 deer was a polioencephalomyelitis with leptomeningitis, which was more prominent within the cerebral cortex, thalamus, hypothalamus, and brainstem. In 3 deer, multifocal microhemorrhages surrounded smaller vessels with or without perivascular cuffing, although vasculitis was not observed. Neuronal necrosis, associated with perineuronal satellitosis and neutrophilic neuronophagia, was most prominent in the thalamus and the brainstem. Positive IHC labeling was mainly observed in the perikaryon, axons, and dendrites of necrotic and intact neurons and, to a much lesser degree, in glial cells, a few neutrophils in the thalamus and the brainstem, and occasionally the cerebral cortex of the 7 deer. There was minimal IHC-based labeling in the cerebellum and hippocampus. ISH labeling was exclusively observed in the cytoplasm of neurons, with a distribution similar to IHC-positive neurons. Neurons positive by IHC and ISH were most prominent in the thalamus and brainstem. The neuropathology of EEE in deer is compared with other species. Based on our findings, EEE has to be considered a differential diagnosis for neurologic disease and meningoencephalitis in white-tailed deer.

  18. H i in Virgo’s “Red and Dead” Dwarf Ellipticals—A Tidal Tail and Central Star Formation

    Energy Technology Data Exchange (ETDEWEB)

    Hallenbeck, Gregory; Koopmann, Rebecca [Union College, Department of Physics and Astronomy, 807 Union Street, Schenectady NY 12308 (United States); Giovanelli, Riccardo; Haynes, Martha P.; Leisman, Lukas [Cornell Center for Astrophysics and Planetary Science (CCAPS), Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Huang, Shan [CCPP, New York University, 4 Washington Place, New York, NY 10003 (United States); Papastergis, Emmanouil, E-mail: hallenbg@union.edu, E-mail: koopmanr@union.edu, E-mail: riccardo@astro.cornell.edu, E-mail: haynes@astro.cornell.edu, E-mail: leisman@astro.cornell.edu, E-mail: shan.huang@nyu.edu, E-mail: papastergis@astro.rug.nl [Kapteyn Astronomical Institute, University of Groningen, Landleven 12, Groningen NL-9747AD (Netherlands)

    2017-08-01

    We investigate a sample of three dwarf elliptical galaxies in the Virgo Cluster that have significant reservoirs of H i. We present deep optical imaging (from CFHT and KPNO), H i spectra (Arecibo), and resolved H i imaging (VLA) of this sample. These observations confirm their H i content and optical morphologies, and indicate that the gas is unlikely to be recently accreted. The sample has more in common with dwarf transitionals, though dwarf transitionals are generally lower in stellar mass and gas fraction. VCC 190 has an H i tidal tail from a recent encounter with the massive spiral galaxy NGC 4224. In VCC 611, blue star-forming features are observed that were not seen by shallower SDSS imaging.

  19. Long-term effects of different type and rates of organic amendments on reclamation of copper mine tailing in Central Chile.

    Science.gov (United States)

    Arellano, Eduardo; Garreton, Bruna; Ginocchio, Rosanna

    2016-04-01

    A study was conducted to evaluate the long-term effects of a single application of organic amendments on a copper mine tailings. Seven years after seeding of a mix of herbaceous plant and planting of ten native trees, and the application of organic amendment, plant community and soil fertility was measured in replicated plots that received six different treatments of waste water treatment plant biosolids (100 ton/ha, and 200 ton/ha), olive oil waste (100 ton/ha, and 200 ton/ha) and pisco grapes waste (90 ton/ha, and 200 ton/ha). A control treatment that received no organic amendment was also measured after seven years. Field measurements demonstrated that application of biosolids and pisco grapes waste, at both rates significantly improved vegetation coverage in comparison to the control treatment (80 and 100% vs control, 25%). The high rates of pisco waste had the highest vegetation diversity and survival in comparison to the other treatments. The high rate of olive oil waste had a negative effect on vegetation development in comparison to the control treatment. The application of organic amendment improved soil fertility in the long-term. All the treatments had a significant higher nitrogen concentration in comparison to the control treatment. The high rates of biosolids and pisco grape waste had a significantly effect of soil carbon concentration. Soil macro-aggregate in the high rate of pisco grape waste were also higher than the control, showing a positive relation between soil recover and vegetation development. We can conclude assisted phytostabilization of mine tailings is likely a technically effective solution for the valorisation of organic residues.

  20. The host-binding domain of the P2 phage tail spike reveals a trimeric iron-binding structure

    International Nuclear Information System (INIS)

    Yamashita, Eiki; Nakagawa, Atsushi; Takahashi, Junichi; Tsunoda, Kin-ichi; Yamada, Seiko; Takeda, Shigeki

    2011-01-01

    The C-terminal domain of a bacteriophage P2 tail-spike protein, gpV, was crystallized and its structure was solved at 1.27 Å resolution. The refined model showed a triple β-helix structure and the presence of iron, calcium and chloride ions. The adsorption and infection of bacteriophage P2 is mediated by tail fibres and tail spikes. The tail spikes on the tail baseplate are used to irreversibly adsorb to the host cells. Recently, a P2 phage tail-spike protein, gpV, was purified and it was shown that a C-terminal domain, Ser87–Leu211, is sufficient for the binding of gpV to host Escherichia coli membranes [Kageyama et al. (2009 ▶), Biochemistry, 48, 10129–10135]. In this paper, the crystal structure of the C-terminal domain of P2 gpV is reported. The structure is a triangular pyramid and looks like a spearhead composed of an intertwined β-sheet, a triple β-helix and a metal-binding region containing iron, calcium and chloride ions

  1. The tailings technology suite

    Energy Technology Data Exchange (ETDEWEB)

    Jaremko, Deborah

    2011-10-15

    Oilsands tailing ponds contain leftover bitumen and asphaltenes, which are dangerous to local wildlife. The Oil Sands Tailings Consortium (OSTCS) was founded by all major mining players and aims to prompt collaboration within the oilsands industry to reclaim the tailings area. Each company has hitherto worked on different tailings management technologies, often duplicating efforts. Some technologies proposed by these oilsands miners were introduced in this article.

  2. Heavy tails of OLS

    DEFF Research Database (Denmark)

    Mikosch, Thomas Valentin; de Vries, Casper

    2013-01-01

    Suppose the tails of the noise distribution in a regression exhibit power law behavior. Then the distribution of the OLS regression estimator inherits this tail behavior. This is relevant for regressions involving financial data. We derive explicit finite sample expressions for the tail probabili...

  3. Talking tails : quantifying the development of tail biting in pigs

    NARCIS (Netherlands)

    Zonderland, J.J.

    2010-01-01

    Tail biting is an adverse behaviour characterised by manipulation of a pig’s tail by another pig resulting in tail damage and a possible tail biting outbreak. Tail biting is a common problem in the pig husbandry causing economic losses and reduced animal welfare worldwide. To prevent tail biting,

  4. Hovercraft drill probes Saraji tailings dam

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    In early operations at BHP-Utah's Saraji Mine in central Queensland, quantities of coking coal were pumped into the tailings dam because the preparation plant's flotation circuit was unable to handle ultra-fines. A reverse circulating drilling rig mounted on a hovercraft was used to recover 22 samples (representing 9 metres of tailings from 11 x 8 x 0.09 metre cores) in an investigation into whether the tailings can now be treated economically. 1 fig.

  5. The Use of a Modular Titanium Baseplate with a Press-Fit Keel Implanted with a Surface Cementing Technique for Primary Total Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Christopher E. Pelt

    2014-01-01

    Full Text Available Little data exists regarding outcomes following TKA performed with surface-cementation for the fixation of modular tibial baseplates with press-fit keels. Thus, we retrospectively reviewed the clinical and radiographic outcomes of 439 consecutive primary TKAs performed with surface cemented tibial components. There were 290 female patients and 149 male patients with average age of 62 years (range 30–84. Two tibial components were revised for aseptic loosening (0.5% and four tibial components (0.9% were removed to improve instability (n=2 or malalignment (n=2. Complications included 13 deep infections treated with 2-stage revision (12 and fusion (1. These results support the surface cement technique with a modular grit-blasted titanium surface and cruciform stem during primary TKA.

  6. Uranium tailings bibliography

    International Nuclear Information System (INIS)

    Holoway, C.F.; Goldsmith, W.A.; Eldridge, V.M.

    1975-12-01

    A bibliography containing 1,212 references is presented with its focus on the general problem of reducing human exposure to the radionuclides contained in the tailings from the milling of uranium ore. The references are divided into seven broad categories: uranium tailings pile (problems and perspectives), standards and philosophy, etiology of radiation effects, internal dosimetry and metabolism, environmental transport, background sources of tailings radionuclides, and large-area decontamination

  7. Uranium tailings sampling manual

    International Nuclear Information System (INIS)

    Feenstra, S.; Reades, D.W.; Cherry, J.A.; Chambers, D.B.; Case, G.G.; Ibbotson, B.G.

    1985-01-01

    The purpose of this manual is to describe the requisite sampling procedures for the application of uniform high-quality standards to detailed geotechnical, hydrogeological, geochemical and air quality measurements at Canadian uranium tailings disposal sites. The selection and implementation of applicable sampling procedures for such measurements at uranium tailings disposal sites are complicated by two primary factors. Firstly, the physical and chemical nature of uranium mine tailings and effluent is considerably different from natural soil materials and natural waters. Consequently, many conventional methods for the collection and analysis of natural soils and waters are not directly applicable to tailings. Secondly, there is a wide range in the physical and chemical nature of uranium tailings. The composition of the ore, the milling process, the nature of tailings depositon, and effluent treatment vary considerably and are highly site-specific. Therefore, the definition and implementation of sampling programs for uranium tailings disposal sites require considerable evaluation, and often innovation, to ensure that appropriate sampling and analysis methods are used which provide the flexibility to take into account site-specific considerations. The following chapters describe the objective and scope of a sampling program, preliminary data collection, and the procedures for sampling of tailings solids, surface water and seepage, tailings pore-water, and wind-blown dust and radon

  8. Tales of island tails

    NARCIS (Netherlands)

    Groot, de Alma V.; Oost, Albert P.; Veeneklaas, Roos M.; Lammerts, Evert Jan; Duin, van Willem E.; Wesenbeeck, van Bregje K.

    2016-01-01

    The Frisian islands (Southern North Sea) have extensive island tails, i.e. the entire downdrift side of an island consisting of salt marshes, dunes, beaches and beach plains, and green beaches. Currently, large parts of these tails are ageing and losing dynamics, partly due to human influence.

  9. Bar-tailed

    NARCIS (Netherlands)

    Duijns, S.; Hidayati, N.A.; Piersma, T.

    2013-01-01

    Capsule Across the European wintering range Bar-tailed Godwits Limosa lapponica lapponica selected polychaete worms and especially Ragworms Hediste diversicolor, with differences between areas due to variations in prey availability.Aims To determine the diet of Bar-tailed Godwits across their

  10. Vertical-Tail Aerodynamic Configuration of Space Shuttle Orbiter

    Science.gov (United States)

    1993-07-16

    effect of a rapid drop in aerodynamic efficiency of the vertical tail. Fig. 6. Scheme of a hypersonic Fig. 7. British Hotal scheme research craft KEY: a...5 - SSTO in the absence of vertical tail 6 - U.S. Space Shuttle In the British Hotal scheme (Fig. 7) the anomalous central single vertical tail...Feiji Sheji [Aircraft Design], National Defense Industry Publishing House, 1987, pp. 227-235. 2 Young J C, Underwood J M. e: at. NASA CP-2283, 1983

  11. Tailings management at Nabarlek

    International Nuclear Information System (INIS)

    Waggitt, P.

    1989-01-01

    As the entire uranium deposit at Nabarlek was mined in 1979, the mine pit was available as a tailing's repository from the time of commencement of ore processing. In the early years Nabarlek's tailings were deposited subaqueously. In 1985 the tailings deposition method was changed to a sub-aerial, or semi-dry, method. Over the subsequent three years there was evidence that the tailings settled further and squeezed water from lower layers. The water was pumped away and treated for removal of radium before being evaporated in one of the mine's evaporation ponds. When milling was completed in 1988 it was decided to try and increase the rate of water removal and so obtain even greater consolidation of the trailings in a shorter time. This was achieved by loading the tailings with a layer of screened leached sands and waste rock placed on a layer of geotextile filter fabric that had been laid over the whole of the tailings surface in the pit. Once this was completed a modified piling rig was used to insert vertical drains, or wicks, up to 30 metres into the tailings. The drains were placed on a square grid at a spacing of 3.25 metres. Water that was forced out of the tailings by the downward pressure of the sand and rock could flow freely to the surface up these drains. Once at the surface the water was gathered into a sump and pumped away for treatment as before. The drains are working very well at present although it will be some considerable time before the water stops flowing. Already settlement of the tailings is apparent and the settled density of the material is increasing. As far as is known this is the first time that such a system has been employed on mine tailings in a pit in this way

  12. The Tail of BPM

    Science.gov (United States)

    Kruba, Steve; Meyer, Jim

    Business process management suites (BPMS's) represent one of the fastest growing segments in the software industry as organizations automate their key business processes. As this market matures, it is interesting to compare it to Chris Anderson's 'Long Tail.' Although the 2004 "Long Tail" article in Wired magazine was primarily about the media and entertainment industries, it has since been applied (and perhaps misapplied) to other markets. Analysts describe a "Tail of BPM" market that is, perhaps, several times larger than the traditional BPMS product market. This paper will draw comparisons between the concepts in Anderson's article (and subsequent book) and the BPM solutions market.

  13. Tail posture predicts tail damage among weaned piglets

    NARCIS (Netherlands)

    Zonderland, J.J.; Riel, van J.W.; Bracke, M.B.M.; Kemp, B.; Hartog, den L.A.; Spoolder, H.A.M.

    2009-01-01

    Tail biting in pigs is a widespread behavioural vice with significant animal welfare and economic consequences. All too often, tail biting is not diagnosed nor dealt with until tail damage is present. To effectively reduce the negative effects of tail biting, it must be diagnosed in an early stage.

  14. Histone H2A mobility is regulated by its tails and acetylation of core histone tails

    International Nuclear Information System (INIS)

    Higashi, Tsunehito; Matsunaga, Sachihiro; Isobe, Keisuke; Morimoto, Akihiro; Shimada, Tomoko; Kataoka, Shogo; Watanabe, Wataru; Uchiyama, Susumu; Itoh, Kazuyoshi; Fukui, Kiichi

    2007-01-01

    Histone tail domains play important roles in cellular processes, such as replication, transcription, and chromosome condensation. Histone H2A has one central and two tail domains, and their functions have mainly been studied from a biochemical perspective. In addition, analyses based on visualization have been employed for functional analysis of some chromatin proteins. In this study, we analyzed histone H2A mobility in vivo by two-photon FRAP, and elucidated that the histone H2A N- and C-terminal tails regulate its mobility. We found that histone H2A mobility was increased following treatment of host cells with a histone deacetylase inhibitor. Our results support a model in which core histone tails directly regulate transcription by interacting with nucleosome DNA via electrostatic interactions

  15. Mine tailings disposal

    International Nuclear Information System (INIS)

    Gonzales, P.A.; Adams, B.J.

    1980-06-01

    The hydrologic evaluation of mine tailings disposal sites after they are abandoned is considered in relation to their potential environmental impact on a long term basis. There is a direct relation between the amounts and types of water leaving a disposal site and the severity of the potential damage to the environment. The evaluation of the relative distribution of the precipitation reaching the ground into evaporation, runoff and infiltration is obtained for a selected site and type of tailings material whose characteristics and physical properties were determined in the soils laboratory. A conceptual model of the hydrologic processes involved and the corresponding mathematical model were developed to simulate the physical system. A computer program was written to solve the set of equations forming the mathematical model, considering the physical properties of the tailings and the rainfall data selected. The results indicate that the relative distribution of the precipitation depends on the surface and upper layer of the tailings and that the position of the groundwater table is governed by the flow through the bottom of the profile considered. The slope of the surface of the mass of tailings was found to be one of the principal factors affecting the relative distribution of precipitation and, therefore, the potential pollution of the environment

  16. Liquefaction of uranium tailings

    International Nuclear Information System (INIS)

    1992-02-01

    Numerical methods for assessing the liquefaction potential of soils are reviewed with a view to their application to uranium tailings. The method can be divided into two categories: total stress analysis, where changes in pore pressure are not considered in the soil model, and effective stress analysis, where changes in pore pressure are included in the soil model. Effective stress analysis is more realistic, but few computer programs exist for such analysis in two or three dimensions. A simple linearized, two-dimensional, finite element effective stress analysis which incorporates volumetric compaction due to shear motion is described and implemented. The new program is applied to the assessment of liquefaction potential of tailings in the Quirke Mine tailings area near Elliot Lake, Ontario. The results are compared with those of a total stress analysis. Both analyses indicate liquefaction would occur if a magnitude 6.0 earthquake were to occur near the area. However, the extent of liquefaction predicted by the effective stress analysis is much less than that predicted by the total stress analysis. The results of both methods are sensitive to assumed material properties and to the method used to determine the cyclic shear strength of the tailings. Further analysis, incorporating more in situ and/or laboratory data, is recommended before conclusions can be made concerning the dynamic stability of these tailings

  17. Uranium mill tailings stabilization

    International Nuclear Information System (INIS)

    Hartley, J.N.; Koehmstedt, P.L.; Esterl, D.J.; Freeman, H.D.

    1980-02-01

    Uranium mill tailings pose a potential radiation health hazard to the public. Therefore, stabilization or disposal of these tailings in a safe and environmentally sound way is needed to minimize radon exhalation and other environmental hazards. One of the most promising concepts for stabilizing U tailings is the use of asphalt emulsion to contain radon and other hazardous materials within uranium tailings. This approach is being investigated at the Pacific Northwest Laboratory. Results of these studies indicate that a radon flux reduction of greater than 99% can be obtained using either a poured-on/sprayed-on seal (3.0 to 7.0 mm thick) or an admixture seal (2.5 to 12.7 cm thick) containing about 18 wt % residual asphalt. A field test was carried out in June 1979 at the Grand Junction tailings pile in order to demonstrate the sealing process. A reduction in radon flux ranging from 4.5 to greater than 99% (76% average) was achieved using a 15.2-cm (6-in.) admix seal with a sprayed-on top coat. A hydrostatic stabilizer was used to apply the admix. Following compaction, a spray coat seal was applied over the admix as the final step in construction of a radon seal. Overburden was applied to provide a protective soil layer over the seal. Included in part of the overburden was a herbicide to prevent root penetration

  18. Uranium mill tailings

    International Nuclear Information System (INIS)

    McLaren, L.H.

    1982-11-01

    This bibliography contains information on uranium mill tailings included in the Department of Energy's Energy Data Base from January 1981 through October 1982. The abstracts are grouped by subject category as shown in the table of contents. Entries in the subject index also facilitate access by subject, e.g., Mill Tailings/Radiation Hazards. Within each category the arrangement is by report number for reports, followed by nonreports in reverse chronological order. These citations are to research reports, journal articles, books, patents, theses, and conference papers from worldwide sources. Five indexes, each preceded by a brief description, are provided: Corporate Author, Personal Author, Subject, Contract Number, and Report Number. (335 abstracts)

  19. Uranium tailings in Canada

    International Nuclear Information System (INIS)

    Boulden, R.S.; Bragg, K.

    1982-01-01

    The last few years have produced significant changes in the way uranium tailings are managed in Canada. This is due both to the development of new technology and to changes in regulatory approach. The interrelationships between these two areas are examined with particular attention paid to the long term and the development of close-out criteria. New technological initiatives are examined including dry placement techniques, pit disposal and deep lake disposal

  20. Heavy-tailed distributions and robustness in economics and finance

    CERN Document Server

    Ibragimov, Marat; Walden, Johan

    2015-01-01

    This book focuses on general frameworks for modeling heavy-tailed distributions in economics, finance, econometrics, statistics, risk management and insurance. A central theme is that of (non-)robustness, i.e., the fact that the presence of heavy tails can either reinforce or reverse the implications of a number of models in these fields, depending on the degree of heavy-tailedness. These results motivate the development and applications of robust inference approaches under heavy tails, heterogeneity and dependence in observations. Several recently developed robust inference approaches are discussed and illustrated, together with applications.

  1. TAIL ASYMPTOTICS OF LIGHT-TAILED WEIBULL-LIKE SUMS

    DEFF Research Database (Denmark)

    Asmussen, Soren; Hashorva, Enkelejd; Laub, Patrick J.

    2017-01-01

    We consider sums of n i.i.d. random variables with tails close to exp{-x(beta)} for some beta > 1. Asymptotics developed by Rootzen (1987) and Balkema, Kluppelberg, and Resnick (1993) are discussed from the point of view of tails rather than of densities, using a somewhat different angle, and sup......We consider sums of n i.i.d. random variables with tails close to exp{-x(beta)} for some beta > 1. Asymptotics developed by Rootzen (1987) and Balkema, Kluppelberg, and Resnick (1993) are discussed from the point of view of tails rather than of densities, using a somewhat different angle...

  2. Copper tailings in stucco mortars

    Directory of Open Access Journals (Sweden)

    Osvaldo Pavez

    Full Text Available Abstract This investigation addressed the evaluation of the use of copper tailings in the construction industry in order to reduce the impact on the environment. The evaluation was performed by a technical comparison between stucco mortars prepared with crushed conventional sand and with copper tailings sand. The best results were achieved with the stucco mortars containing tailings. The tailings presented a fine particles size distribution curve different from that suggested by the standard. The values of compressive strength, retentivity, and adherence in the stucco mortars prepared with copper tailings were much higher than those obtained with crushed sand. According to the results from this study, it can be concluded that the preparation of stucco mortars using copper tailings replacing conventional sand is a technically feasible alternative for the construction industry, presenting the benefit of mitigating the impact of disposal to the environment.

  3. Injurious tail biting in pigs

    DEFF Research Database (Denmark)

    D'Eath, R.B.; Amott, G.; Turner, S. P.

    2014-01-01

    underlying processes of tail biting. A quantitative comparison of the efficacy of different methods of provision of manipulable materials, and a review of current practices in countries and assurance schemes where tail docking is banned, both suggest that daily provision of small quantities of destructible...... and prevention of tail damage. However, there is a lack of scientific studies on how best to respond to outbreaks: the effectiveness of, for example, removing biters and/or bitten pigs, increasing enrichment, or applying substances to tails should be investigated. Finally, some breeding companies are exploring...

  4. Oilsand tailings : solving the issues

    Energy Technology Data Exchange (ETDEWEB)

    Granson, E.

    2008-11-15

    Oilsands tailings management is an integral part of oil sands research and development. Studies to decrease land disturbance and to resolve environmental and safety issues are underway at several government agencies and industry groups, including the Alberta Energy Research Institute, the Oil Sands Tailings Research Facility and Natural Resources Canada's CANMET Advanced Separation Technologies division. Fresh tailings that come from the bitumen extraction process are composed of 85 to 90 per cent water and 10 to 15 per cent solids having the consistency of muddy water. The 3 zones that develop following discharge into the tailings ponds are 3 metres of clear water; residual hydrocarbons that float on the surface; and, a 1 metre zone of water and settling clay particles known as mature fine tailings (MFT) which comprise about 90 per cent of the volume of the tailings pond. The tailings ponds must be built in areas where there is no bitumen suitable for surface mining. The impounded area is surrounded by tailings dykes built from local overburden materials. As such, tailings ponds are managed as dams according to Alberta Dam Safety regulation requirements. Dam stability is increased by the installation of internal seepage control measures. This article described the key guidelines and objectives for the construction of tailings ponds. It also described the 3 primary types of reclamation settings, namely aquatic reclamation, wetland reclamation and terrestrial reclamation. Water removed from the MFT can be recycled back to the plant to reduce the amount of water used from the river. Although this contributes to lower energy costs, there are challenges regarding salt levels that builds up in piping and equipment. The presence of water in the tailings also prevents tailings reclamation. In addition to mechanical systems to remove water, researchers are also considering the use of chemicals and natural processes. In the consolidated tailings (CT) process, the

  5. Tail-weighted dependence measures with limit being the tail dependence coefficient

    KAUST Repository

    Lee, David

    2017-12-02

    For bivariate continuous data, measures of monotonic dependence are based on the rank transformations of the two variables. For bivariate extreme value copulas, there is a family of estimators (Formula presented.), for (Formula presented.), of the extremal coefficient, based on a transform of the absolute difference of the α power of the ranks. In the case of general bivariate copulas, we obtain the probability limit (Formula presented.) of (Formula presented.) as the sample size goes to infinity and show that (i) (Formula presented.) for (Formula presented.) is a measure of central dependence with properties similar to Kendall\\'s tau and Spearman\\'s rank correlation, (ii) (Formula presented.) is a tail-weighted dependence measure for large α, and (iii) the limit as (Formula presented.) is the upper tail dependence coefficient. We obtain asymptotic properties for the rank-based measure (Formula presented.) and estimate tail dependence coefficients through extrapolation on (Formula presented.). A data example illustrates the use of the new dependence measures for tail inference.

  6. A model of the magnetospheric tail with current-free lobes

    Science.gov (United States)

    Stern, David P.

    1990-01-01

    A model of the earth's tail field with no current density in its high latitude lobes is obtained as a modification of Tsyganenko's tail model. This is achieved by replacing Tsyganenko's current element with one in which the current density ends abruptly at a distance D from the central axis.

  7. Mercury's Dynamic Magnetic Tail

    Science.gov (United States)

    Slavin, James A.

    2010-01-01

    The Mariner 10 and MESSENGER flybys of Mercury have revealed a magnetosphere that is likely the most responsive to upstream interplanetary conditions of any in the solar system. The source of the great dynamic variability observed during these brief passages is due to Mercury's proximity to the Sun and the inverse proportionality between reconnection rate and solar wind Alfven Mach number. However, this planet's lack of an ionosphere and its small physical dimensions also contribute to Mercury's very brief Dungey cycle, approx. 2 min, which governs the time scale for internal plasma circulation. Current observations and understanding of the structure and dynamics of Mercury's magnetotail are summarized and discussed. Special emphasis will be placed upon such questions as: 1) How much access does the solar wind have to this small magnetosphere as a function of upstream conditions? 2) What roles do heavy planetary ions play? 3) Do Earth-like substorms take place at Mercury? 4) How does Mercury's tail respond to extreme solar wind events such coronal mass ejections? Prospects for progress due to advances in the global magnetohydrodynamic and hybrid simulation modeling and the measurements to be taken by MESSENGER after it enters Mercury orbit on March 18, 2011 will be discussed.

  8. Rehabilitation of uranium tailings impoundments

    International Nuclear Information System (INIS)

    Crawley, A.H.

    1983-01-01

    Under Australian environmental controls relating to the management of uranium tailings, it is no longer acceptable practice to search for a rehabilitation strategy at the end of production when the generation of tailings has ceased. The uranium projects currently in production and those being proposed are tightly regulated by the authorities. The waste management plans must consider site specific factors and must include selection of appropriate disposal sites and design for long term containment. The final encapsulation in engineered facilities must take into account the probable routes to the environment of the tailings. Rehabilitation shoud be undertaken by the mining and milling operators to standards approved by appropriate authorities. Appropriate administrative arrangements are required, by way of technical committees and financial bonds to ensure that agreed standards of rehabilitation may be achieved. Past and present experience with the rehabilitation of uranium tailings impoundments in Australia is discussed

  9. Tails, Fears and Risk Premia

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Todorov, Victor

    We show that the compensation for rare events accounts for a large fraction of the equity and variance risk premia in the S&P 500 market index. The probability of rare events vary significantly over time, increasing in periods of high market volatility, but the risk premium for tail events cannot...... solely be explained by the level of the volatil- ity. Our empirical investigations are essentially model-free. We estimate the expected values of the tails under the statistical probability measure from "medium" size jumps in high-frequency intraday prices and an extreme value theory approximation...... for the corresponding jump tail density. Our estimates for the risk-neutral expectations are based on short maturity out-of-the money options and new model-free option implied variation measures explicitly designed to separate the tail probabilities. At a general level, our results suggest that any satisfactory...

  10. Full Genome Characterization of a New Simian Immune Deficiency Virus Lineage in a Naturally Infected Cercopithecus ascanius whitesidei in the Democratic Republic of Congo Reveals High Genetic Diversity Among Red-Tailed Monkeys in Central and Eastern Africa.

    Science.gov (United States)

    Ahuka-Mundeke, Steve; Mbala-Kingebeni, Placide; Ndimbo-Kumogo, Simon-Pierre; Foncelle, Caroline; Lunguya-Metila, Octavie; Muyembe-Tamfum, Jean-Jacques; Delaporte, Eric; Peeters, Martine; Ayouba, Ahidjo

    2017-07-01

    Our knowledge on simian immune deficiency virus (SIV) diversity and evolution in the different nonhuman primate species is still incomplete. In this study, we report the full genome characterization of a new SIV from a red-tailed monkey (2013DRC-I8), from the Cercopithecus ascanius whitesidei subspecies, in the Democratic Republic of Congo (DRC). The new full-length genome is 9,926 bp long, and the genomic structure is similar to that of other SIVs with the absence of vpx and vpu genes. The new SIVasc-13DRC-I8 strain fell within the Cercopithecus specific SIV lineage. SIVasc-13DRC-I8 and previously reported SIVrtg from the C.a. schmidti subspecies in Uganda did not form a separate species-specific SIV lineage. These observations provide additional evidence for high genetic diversity and the complex evolution of SIVs in the Cercopithecus genus. More studies on a large number of monkeys from a wider geographic area are needed to understand SIV evolution.

  11. More tail lesions among undocked than tail docked pigs in a conventional herd

    DEFF Research Database (Denmark)

    Lahrmann, H. P.; Busch, M. E.; D'Eath, R. B.

    2017-01-01

    The vast majority of piglets reared in the European Union (EU) and worldwide is tail docked to reduce the risk of being tail bitten, even though EU animal welfare legislation bans routine tail docking. Many conventional herds experience low levels of tail biting among tail docked pigs, however...... it is not known, what the prevalence would have been had the pigs not been tail docked. The aim of this study was to compare the prevalence of tail lesions between docked and undocked pigs in a conventional piggery in Denmark with very low prevalence of tail biting among tail docked pigs. The study included 1922...... that housing pigs with intact tails in conventional herds with very low prevalence of tail biting among tail docked pigs, will increase the prevalence of pigs with tail lesions considerably, and pig producers will need more hospital pens. Abattoir data indicate that tail biting remarks from meat inspection...

  12. Flip, flop and fly: modulated motor control and highly variable movement patterns of autotomized gecko tails.

    Science.gov (United States)

    Higham, Timothy E; Russell, Anthony P

    2010-02-23

    Many animals lose and regenerate appendages, and tail autotomy in lizards is an extremely well-studied example of this. Whereas the energetic, ecological and functional ramifications of tail loss for many lizards have been extensively documented, little is known about the behaviour and neuromuscular control of the autotomized tail. We used electromyography and high-speed video to quantify the motor control and movement patterns of autotomized tails of leopard geckos (Eublepharis macularius). In addition to rhythmic swinging, we show that they exhibit extremely complex movement patterns for up to 30 min following autotomy, including acrobatic flips up to 3 cm in height. Unlike the output of most central pattern generators (CPGs), muscular control of the tail is variable and can be arrhythmic. We suggest that the gecko tail is well suited for studies involving CPGs, given that this spinal preparation is naturally occurring, requires no surgery and exhibits complex modulation.

  13. Research on Long Tail Recommendation Algorithm

    Science.gov (United States)

    Hu, Xuezhi; Zhang, Chuang; Wu, Ming; Zeng, Yang

    2017-10-01

    Most recommendation systems in the major electronic commerce platforms are influenced by the long tail effect more or less. There are sufficient researches of how to assess recommendation effect while no criteria to evaluate long tail recommendation rate. In this study, we first discussed the existing problems of recommending long tail products through specific experiments. Then we proposed a long tail evaluation criteria and compared the performance in long tail recommendation between different models.

  14. Phytomining for Artisanal Gold Mine Tailings Management

    Directory of Open Access Journals (Sweden)

    Baiq Dewi Krisnayanti

    2016-08-01

    Full Text Available Mine tailings are generally disposed of by artisanal and small scale gold miners in poorly constructed containment areas and this leads to environmental risk. Gold phytomining could be a possible option for tailings management at artisanal and small-scale gold mining (ASGM locations where plants accumulate residual gold in their above ground biomass. The value of metal recovered from plants could offset some of the costs of environmental management. Getting gold into plants has been repeatedly demonstrated by many research groups; however, a simple working technology to get gold out of plants is less well described. A field experiment to assess the relevance of the technology to artisanal miners was conducted in Central Lombok, Indonesia between April and June 2015. Tobacco was planted in cyanidation tailings (1 mg/kg gold and grown for 2.5 months before the entire plot area was irrigated with NaCN to induce metal uptake. Biomass was then harvested (100 kg, air dried, and ashed by miners in equipment currently used to ash activated carbon at the end of a cyanide leach circuit. Borax and silver as a collector metal were added to the tobacco ash and smelted at high temperature to extract metals from the ash. The mass of the final bullion (39 g was greater than the mass of silver used as a collector (31 g, indicating recovery of metals from the biomass through the smelt process. The gold yield of this trial was low (1.2 mg/kg dry weight biomass concentration, indicating that considerable work must still be done to optimise valuable metal recovery by plants at the field scale. However, the described method to process the biomass was technically feasible, and represents a valid technique that artisanal and small-scale gold miners are willing to adopt if the economic case is good.

  15. The tail of integrin activation

    Science.gov (United States)

    Anthis, Nicholas J; Campbell, Iain D

    2010-01-01

    Integrins are essential adhesion receptors found on the surfaces of all metazoan cells. As regulators of cell migration and extracellular matrix assembly, these membrane-spanning heterodimers are critical for embryonic development, tissue repair and immune responses. Signals transmitted by integrins from outside to inside the cell promote cell survival and proliferation, but integrin affinity for extracellular ligands can also be controlled by intracellular cues. This bidirectional signaling is mediated by the short cytoplasmic tails of the two integrin subunits. Recent structural and functional studies of various integrin fragments and complexes between the cytoplasmic tails and intracellular proteins, such as talin, have provided new insight into the signaling processes centered around the tails, particularly inside-out integrin activation. PMID:21216149

  16. Dewatering tailings impoundments : interior drains

    International Nuclear Information System (INIS)

    Charlie, W.A.; Doehring, D.O.; Durnford, D.S.

    1984-01-01

    For the design of a new uranium tailings impoundment in the western United States, it was proposed that an interior drainage system be considered to economically and reliably minimize potential short- and long-term environmental impacts. The objectives were to decrease the effective hydraulic head on the clay liner, to dewater and stabilize the tailings, and to increase the amount of water recycled to the mill. In addition, desaturation of the impoundment would induce capillary pressure (negative porewater pressure), further reducing the potential movement of dissolved pollutants. This paper presents saturated and unsaturated seepage principles and reviews the concept, criteria and design of the various interior drainage systems considered

  17. Why are most EU pigs tail docked?

    DEFF Research Database (Denmark)

    D'eath, R.B.; Niemi, J.K.; Vosough Ahmadi, B.

    2016-01-01

    To limit tail biting incidence, most pig producers in Europe tail dock their piglets. This is despite EU Council Directive 2008/120/EC banning routine tail docking and allowing it only as a last resort. The paper aims to understand what it takes to fulfil the intentions of the Directive by examin......To limit tail biting incidence, most pig producers in Europe tail dock their piglets. This is despite EU Council Directive 2008/120/EC banning routine tail docking and allowing it only as a last resort. The paper aims to understand what it takes to fulfil the intentions of the Directive...

  18. The avian tail reduces body parasite drag by controlling flow separation and vortex shedding.

    Science.gov (United States)

    Maybury, W J; Rayner, J M

    2001-07-07

    The aerodynamic effect of the furled avian tail on the parasite drag of a bird's body was investigated on mounted, frozen European starling Sturnus vulgaris in a wind tunnel at flight speeds between 6 and 14 m s(-1). Removal of tail rectrices and dorsal and ventral covert feathers at the base of the tail increased the total parasite drag of the body and tail by between 25 and 55%. Flow visualization and measurements of dynamic pressure in the tail boundary layer showed that in the intact bird a separation bubble forms on the ventral side of the body, and reattaches to the ventral side of the tail. This bubble is a consequence of the morphology of the body, with a rapid contraction posterior to the pelvis and hind legs. The tail and the covert feathers at its base act as a combined splitter plate and wedge to control vortex shedding and body wake development, and thereby are important to minimize drag. This hitherto unsuspected mechanism is central to understanding the morphology of the avian body, and may have had a significant influence on the evolution of avian tail morphology by pre-adapting the tail for radiation and specialization as an aerodynamic lifting structure and as an organ of communication in sexual selection.

  19. Uranium-mill-tailings conditioning technology

    International Nuclear Information System (INIS)

    Dreesen, D.R.; Cokal, E.J.; O'Brien, P.D.; Thode, E.F.; Wangen, L.E.; Williams, J.M.

    1982-01-01

    Conditioning of uranium mill tailings involves the physico-chemical alteration of tailings to remove or immobilize mobile radionuclides and toxic trace elements before disposal in a repository. The principal immobilization approach under investigation is sntering tailings at high temperatures (1100 to 1200 0 C) to radically alter the structure of tailings. This thermal stabilization at 1200 0 C reduced radon emanation power for tailings sands by factors of 20 to 200 and for tailings fines by factors of 300 to 1100. Substantial reductions in the leachability of most contaminants have been found for thermally conditioned tailings. A conceptual thermal stabilization process has been developed wherein obsolete coal-fired rotary cement kilns perform the sintering. An economic analysis of this conceptual process has shown that thermal stabilization can be competitive at certain tailings sites with other remedial actions requiring the excavation, transportation, and burial of tailings in a repository. An analysis of the long-term radiological hazard posed by untreated tailings and by tailings conditioned by radionuclide removal has illustrated the necessity of extracting both 226 Ra and 230 Th to achieve long-term hazard reductions. Sulfuric acid extraction of residual mineral values and important radionuclides from tailings has been investigated. Concentrated H 2 SO 4 can extract up to 80% of the 226 Ra, 70% of the Ba, and 90% of the 230 Th from tailings in a single stag extraction. An economic analysis of a sulfuric acid leach process was made to determine whether the value of minerals recovered from tailings would offset the leaching cost. For one relatively mineral-rich tailings pile, the U and V values would more than pay for the leaching step and would contribute about 60% of the costs of moving and burying the tailings at a new site

  20. Cylinder Symmetric Measures with the Tail Property

    NARCIS (Netherlands)

    Balkema, A.A.

    2006-01-01

    Abstract: A Pareto distribution has the property that any tail of the distribution has the same shape as the original distribution. The exponential distribution and the uniform distribution have the tail property too. The tail property characterizes the univariate generalized Pareto distributions.

  1. Electrodialytic remediation of suspended mine tailings

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Rojo, Adrian; Pino, Denisse

    2008-01-01

    This work shows the laboratory results of nine electrodialytic remediation experiments on copper mine tailings. A newly designed remediation cell, where the solids were kept in suspension by airflow, was tested. The results show that electric current could remove copper from suspended tailings...... experiment at 40 mA, with approximately 137.5 g mine tailings on dry basis. The removal for a static (baseline) experiment only amounted 15% when passing approximately the same amount of charge through 130 g of mine tailings. The use of air bubbling to keep the tailings suspended increased the removal...

  2. Uranium mine tailings and obligations to future generations

    International Nuclear Information System (INIS)

    Brook, A.

    1980-01-01

    Low-level wastes from uranium mine/mill operations, because of their huge volume, are a serious problem, yet relatively little attention has been paid to them. Management of tailings piles and waste liquids in the short term is fairly effective. However these management techniques involve continuous, active treatment of the wastes, which may not continue after operations shut down, and rely on containment structures with a short effective life. Tailings can probably be rendered safe for future generations if sufficient resources are devoted to the task. The central moral question is whether we are obligated to assume the costs of tailings management, or whether it is permissible to pass them on to future generations. The basic moral principle that each person has the same value as any other implies that the generation that reaps the benefits of nuclear power must assume the costs of managing mine tailings and not discriminate in favour of one group of persons, our own generation. The argument that people who may exist in the future have intrinsically less value than people currently alive is not accepted by the author. The methodology for determining obligations to future generations which has been applied to mine/mill wastes could be applied to other nuclear issues, too. (LL)

  3. Uranium mill tailings neutralization: contaminant complexation and tailings leaching studies

    International Nuclear Information System (INIS)

    Opitz, B.E.; Dodson, M.E.; Serne, R.J.

    1985-05-01

    Laboratory experiments were performed to compare the effectiveness of limestone (CaCO 3 ) and hydrated lime [Ca(OH) 2 ] for improving waste water quality through the neutralization of acidic uranium mill tailings liquor. The experiments were designed to also assess the effects of three proposed mechanisms - carbonate complexation, elevated pH, and colloidal particle adsorption - on the solubility of toxic contaminants found in a typical uranium mill waste solution. Of special interest were the effects each of these possible mechanisms had on the solution concentrations of trace metals such as Cd, Co, Mo, Zn, and U after neutralization. Results indicated that the neutralization of acidic tailings to a pH of 7.3 using hydrated lime provided the highest overall waste water quality. Both the presence of a carbonate source or elevating solution pH beyond pH = 7.3 resulted in a lowering of previously achieved water quality, while adsorption of contaminants onto colloidal particles was not found to affect the solution concentration of any constituent investigated. 24 refs., 8 figs., 19 tabs

  4. A tail of two phages: Genomic and functional analysis of Listeria monocytogenes phages vB_LmoS_188 and vB_LmoS_293 reveal the receptor-binding proteins involved in host specificity.

    Directory of Open Access Journals (Sweden)

    Aidan eCasey

    2015-10-01

    Full Text Available The physical characteristics of bacteriophages establish them as viable candidates for downstream development of pathogen detection assays and biocontrol measures. To utilize phages for such purposes, a detailed knowledge of their host interaction mechanisms is a prerequisite. There is currently a wealth of knowledge available concerning Gram-negative phage-host interaction, but little by comparison for Gram-positive phages and Listeria phages in particular. In this research, the lytic spectrum of two recently isolated Listeria monocytogenes phages (vB_LmoS_188 and vB_LmoS_293 was determined, and the genomic basis for their observed serotype 4b/4e host-specificity was investigated using comparative genomics. The late tail genes of these phages were identified to be highly conserved when compared to other serovar 4-specific Listeria phages. Spontaneous mutants of each of these phages with broadened host specificities were generated. Their late tail gene sequences were compared with their wild-type counterparts resulting in the putative identification of the products of ORF 19 of vB_LmoS_188 and ORF 20 of vB_LmoS_293 as the receptor binding proteins of these phages. The research findings also indicate that conserved baseplate architectures and host interaction mechanisms exist for Listeria siphoviruses with differing host-specificities, and further contribute to the current knowledge of phage-host interactions with regard to Listeria phages.

  5. Which is the most preventive measure against tail damage in finisher pigs: tail docking, straw provision or lowered stocking density?

    DEFF Research Database (Denmark)

    Larsen, Mona Lilian Vestbjerg; Andersen, Heidi Mai-Lis; Pedersen, Lene Juul

    2018-01-01

    One challenge of intensive pig production is tail damage caused by tail biting, and farmers often decrease the prevalence of tail damage through tail docking. However, tail docking is not an optimal preventive measure against tail damage and thus, it would be preferable to replace it. The aim...... by scoring the tail of each individual pig. A pen was recorded as a tail damage pen and no longer included in the study if at least one pig in a pen had a bleeding tail wound; thus, only the first incidence of tail damage on pen level was recorded. Data were analysed by a Cox regression for survival analysis...

  6. Assessing Risks of Mine Tailing Dam Failures

    Science.gov (United States)

    Concha Larrauri, P.; Lall, U.

    2017-12-01

    The consequences of tailings dam failures can be catastrophic for communities and ecosystems in the vicinity of the dams. The failure of the Fundão tailings dam at the Samarco mine in 2015 killed 19 people with severe consequences for the environment. The financial and legal consequences of a tailings dam failure can also be significant for the mining companies. For the Fundão tailings dam, the company had to pay 6 billion dollars in fines and twenty-one executives were charged with qualified murder. There are tenths of thousands of active, inactive, and abandoned tailings dams in the world and there is a need to better understand the hazards posed by these structures to downstream populations and ecosystems. A challenge to assess the risks of tailings dams in a large scale is that many of them are not registered in publicly available databases and there is little information about their current physical state. Additionally, hazard classifications of tailings dams - common in many countries- tend to be subjective, include vague parameter definitions, and are not always updated over time. Here we present a simple methodology to assess and rank the exposure to tailings dams using ArcGIS that removes subjective interpretations. The method uses basic information such as current dam height, storage volume, topography, population, land use, and hydrological data. A hazard rating risk was developed to compare the potential extent of the damage across dams. This assessment provides a general overview of what in the vicinity of the tailings dams could be affected in case of a failure and a way to rank tailings dams that is directly linked to the exposure at any given time. One hundred tailings dams in Minas Gerais, Brazil were used for the test case. This ranking approach could inform the risk management strategy of the tailings dams within a company, and when disclosed, it could enable shareholders and the communities to make decisions on the risks they are taking.

  7. Unique structural features facilitate lizard tail autotomy.

    Science.gov (United States)

    Sanggaard, Kristian W; Danielsen, Carl Chr; Wogensen, Lise; Vinding, Mads S; Rydtoft, Louise M; Mortensen, Martin B; Karring, Henrik; Nielsen, Niels Chr; Wang, Tobias; Thøgersen, Ida B; Enghild, Jan J

    2012-01-01

    Autotomy refers to the voluntary shedding of a body part; a renowned example is tail loss among lizards as a response to attempted predation. Although many aspects of lizard tail autotomy have been studied, the detailed morphology and mechanism remains unclear. In the present study, we showed that tail shedding by the Tokay gecko (Gekko gecko) and the associated extracellular matrix (ECM) rupture were independent of proteolysis. Instead, lizard caudal autotomy relied on biological adhesion facilitated by surface microstructures. Results based on bio-imaging techniques demonstrated that the tail of Gekko gecko was pre-severed at distinct sites and that its structural integrity depended on the adhesion between these segments.

  8. Quantization function for attractive, singular potential tails

    International Nuclear Information System (INIS)

    Raab, Patrick N.

    2010-01-01

    The interaction between atoms and molecules with each other are deep potential wells with attractive, singular tails. Bound state energies are determined by a quantization function according to a simple quantization rule. This function is dominantly determined by the singular potential tail for near-threshold states. General expressions for the low- and high-energy contributions of the singular potential tail to the quantization function, as well as the connection to the scattering length are presented in two and three dimensions. Precise analytical expressions for the quantization function are determined for the case of potential tails proportional to -1/r 4 and -1/r 6 for three dimensions. (orig.)

  9. Evaluation of chemical stabilizers and windscreens for wind erosion control of uranium mill tailings

    Energy Technology Data Exchange (ETDEWEB)

    Elmore, M.R.; Hartley, J.N.

    1984-08-01

    Potential wind erosion of uranium mill tailings is a concern for the surface disposal of tailings at uranium mills. Wind-blown tailings may subsequently be redeposited on areas outside the impoundment. Pacific Northwest Laboratory (PNL) is investigating techniques for fugitive dust control at uranium mill tailings piles. Laboratory tests, including wind tunnel studies, were conducted to evaluate the relative effectiveness of 43 chemical stabilizers. Seventeen of the more promising stabilizers were applied to test plots on a uranium tailings pile at the American Nuclear Corporation-Gas Hills Project mill site in central Wyoming. The durabilities of these materials under actual site conditions were evaluated over time. In addition, field testing of commercially available windscreens was conducted. Test panels were constructed of eight different materials at the Wyoming test site to compare their durability. A second test site was established near PNL to evaluate the effectiveness of windscreens at reducing wind velocity, and thereby reduce the potential for wind erosion of mill tailings. Results of the laboratory land field tests of the chemical stabilizers and windscreens are presented, along with costs versus effectiveness of these techniques for control of wind erosion at mill tailings piles. 12 references, 4 figures, 6 tables.

  10. Tail Risk Constraints and Maximum Entropy

    Directory of Open Access Journals (Sweden)

    Donald Geman

    2015-06-01

    Full Text Available Portfolio selection in the financial literature has essentially been analyzed under two central assumptions: full knowledge of the joint probability distribution of the returns of the securities that will comprise the target portfolio; and investors’ preferences are expressed through a utility function. In the real world, operators build portfolios under risk constraints which are expressed both by their clients and regulators and which bear on the maximal loss that may be generated over a given time period at a given confidence level (the so-called Value at Risk of the position. Interestingly, in the finance literature, a serious discussion of how much or little is known from a probabilistic standpoint about the multi-dimensional density of the assets’ returns seems to be of limited relevance. Our approach in contrast is to highlight these issues and then adopt throughout a framework of entropy maximization to represent the real world ignorance of the “true” probability distributions, both univariate and multivariate, of traded securities’ returns. In this setting, we identify the optimal portfolio under a number of downside risk constraints. Two interesting results are exhibited: (i the left- tail constraints are sufficiently powerful to override all other considerations in the conventional theory; (ii the “barbell portfolio” (maximal certainty/ low risk in one set of holdings, maximal uncertainty in another, which is quite familiar to traders, naturally emerges in our construction.

  11. Lateral movements of a massive tail influence gecko locomotion: an integrative study comparing tail restriction and autotomy

    OpenAIRE

    Jagnandan, Kevin; Higham, Timothy E.

    2017-01-01

    Tails are an intricate component of the locomotor system for many vertebrates. Leopard geckos (Eublepharis macularius) possess a large tail that is laterally undulated during steady locomotion. However, the tail is readily shed via autotomy, resulting in the loss of tail function, loss in body mass, and a cranial shift in the center of mass. To elucidate the function of tail undulations, we investigated changes in limb kinematics after manipulating the tail artificially by restricting tail un...

  12. A new model of tail diffusion of phosphorus and boron in silicon

    International Nuclear Information System (INIS)

    Morehead, F.F.; Lever, R.F.

    1986-01-01

    It is well known that high surface concentration phosphorus diffusion leads to deeply penetrating tails in its concentration profile. At 700 0 C the tail diffusivity exceeds that of low concentration phosphorus by a factor of a thousand. Less spectacular, but very significant tailing also affects boron, making the conventional models contained in commonly available process simulation programs quite inaccurate for boron diffusions with high surface concentrations. The authors show that the observed tailing can be accounted for by a model whose central assumption is the local equality of dopant and oppositely directed defect fluxes. As predicted by the model, the effect is greatest for normal processing at low temperatures for high surface concentrations. It is minimal for the high temperatures of rapid thermal annealing and unrelated to transient effects

  13. Effect of beta-adrenergic receptor antagonists on nicotine-induced tail-tremor in rats.

    Science.gov (United States)

    Suemaru, K; Gomita, Y; Furuno, K; Araki, Y

    1993-09-01

    The effects of various beta-adrenergic receptor antagonists on nicotine-induced tail-tremor were investigated in rats. Atenolol (5 and 10 mg/kg, IP), arotinolol (5 and 10 mg/kg, IP), and carteolol (5 and 10 mg/kg, IP), hydrophilic beta-adrenergic receptor antagonists, did not affect the tail-tremor induced by nicotine given at a dose of 0.5 mg/kg SC. However, propranolol (5-20 mg/kg, IP) and pindolol (5-20 mg/kg, IP), nonselective and lipophilic beta-adrenergic receptor antagonists, did suppress the tail-tremor dose dependently. In contrast, metoprolol (5-20 mg/kg, IP), lipophilic and beta 1-selective adrenergic receptor antagonists, did not show such an effect. These results suggest that nicotine-induced tail-tremors may be mediated through central beta 2-adrenergic receptors as an appearance and developmental mechanism.

  14. Performance Comparison between Neutralization Tailings and Flotation Tailings Used for Backfill Mix and Mechanism Analysis

    Directory of Open Access Journals (Sweden)

    Bin Han

    2016-01-01

    Full Text Available A comparison test of different tailings used for underground backfill was conducted, using neutralized tailings from BIOX and flotation tailings of Jinfeng Mine. Laboratory comparison test results show that, with neutralized tailings, when the cement dosage is at 19%, backfill UCS after 7 days, 14 days, and 28 days are 105%–163%, 80%–102%, and 33%–43%, respectively, which are higher than those of flotation tailings. When the cement dosage is at 12%, backfill UCS after 7 days, 14 days, and 28 days are 58%–77%, 50%–60%, and 28%–51%, respectively, which are higher than those of flotation tailings. Slurry fluidity of neutralized tailings is lower than that of flotation tailings, while, in these two tailings, the difference of slump and diffusivity values is less than 6%, which is not a significant difference in slurry fluidity. The reason for neutralized tailings showing higher UCS is as follows: during backfill curing, neutralization tailings produce abundant crystals of CaSO4·2H2O in interlaced structure which helps in combining aggregates closely; CaSO4·2H2O hydrates with C3A C4AF contained in the cement and forms clavate cement bacillus which works as a micro reinforcing steel bar. The test proved that neutralized tailings are more optimal for backfilling.

  15. Characterization and dewatering of flotation technological tailings

    Directory of Open Access Journals (Sweden)

    Grigorova I.

    2014-01-01

    Full Text Available The treatment of flotation tailings is today a subject of interest in mineral processing because of the potential of wasted materials as an actual mineral resource and because of environmental reasons. Decantation ponds are found at almost every mine in the world. They are large earth fill dams containing the residue of the milling process to extract metals from mined ores. Traditional wet tailings disposal has been problematic due to the risk of ground water contamination and the difficulty in rehabilitating storage sites. Tailings dams are at risk of failure due to leakage, instability, liquefaction, and poor design. In the last few years the use of paste technology in the disposal of mine tailings is increasingly studied as an option to conventional tailings dams. The Lucky Invest Concentrator is located in the Eastern Rhodopes Mountain of Bulgaria. Since 1959 lead-zinc ores are dressed. Finally, during the flotation cycle lead and zinc concentrates are produced. The final technological processing waste precipitates in tailing pond. Research and development program has started to established opportunities to obtain dry deposit of the ore processing residue and analyses the feature of new tailing disposal method. The tailings particle size distributions and chemical compositions were determined. The data from laboratory and pilot scale tests clearly illustrate that there are the possibilities to obtaine lead-zinc dewatered tailings. The experimental results show that new cyclone modifications have a potential in dewatering technology of flotation tailings. It appears that dewatering cyclones can be an approach on new tailings pond elimination technology.

  16. Profitable tail-end production

    Energy Technology Data Exchange (ETDEWEB)

    Pinchbeck, R.H.

    1997-12-31

    This presentation discusses the origins of the present challenge faced in making mature oil fields profitable in the North Sea. It briefly examines the origins of these challenges, which are rooted in the industrial psychology of the North Sea. It develops a methodological formula for the successful re-engineering of inefficiently-run assets, focusing in particular on the personnel management aspects. It identifies some key areas to seek sustainable cost reductions and recognises the importance of renewing the context for investment in tail-end fields. Finally, it speculates about the way in which the learnings developed in the experiences of the last few years will influence the future of the North Sea. 2 refs.

  17. Tailings treatment and nano-particles

    Energy Technology Data Exchange (ETDEWEB)

    McEachern, P.; Burkus, Z.; Yu, T.; Ulrich, A.; Zhu, D. [Alberta Environment, Edmonton, AB (Canada)

    2009-07-01

    Oil sands fluid tailings are heterodispersed colloidal and suspended particles comprised of hydrophilic clays, metal oxides, organic acids, and hydration shells that create weak gels. Approximately 3 per cent of the total tailings stream are particles less than 0.2 {mu}m. Smaller fines are mobile with a high charge, and have a reactive surface that attracts organics and heavy metals. The fines also stick to bitumen and inhibit recovery. The particles in clays in tailings are typically less than 2 {mu}m. The multivalent ion increase the tendency for gelling. Treatment processes for fluid fine tailings include flocculation, chemical oxidation, and biological fermentation oxidation processes. Large polyacrylamides are used to capture fines in cross-bridged structures, while inorganic gels are used to hold water. Exopolysaccharides are used in mature fine tailings remediation processes. Other nanotechnology processes for tailings include photo-catalyzed oxidation, ozone pre-treatment; and zero valent ion treatments. Biotreatment researchers are now exploring the use of engineered microbially-mediated wastewater treatment technologies to accelerate oil sands tailings consolidation. Organic coagulants are also being considered as a means of consolidating tailings. It was concluded that various engineering reactors are now being investigated in order to accelerate microbial transformations. tabs., figs.

  18. The big head and the long tail

    DEFF Research Database (Denmark)

    Helles, Rasmus

    2013-01-01

    on the generative mechanism behind the long–tail distribution of Web site use. The analysis shows that the long tail should be seen as a tiered version of popular top sites, and argues that downsizing of large–scale datasets in combination with qualitative and/or small–scale quantitative procedures may provide...

  19. Electrodialytic remediation of copper mine tailings

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Rojo, A.; Ottpsen, Lisbeth M.

    2005-01-01

    Mining activities in Chile have generated large amounts of solid waste, which have been deposited in mine tailing impoundments. These impoundments cause concern to the communities due to dam failures or natural leaching to groundwater and rivers.This work shows the laboratory results of nine...... electrodialytic remediation experiments on copper mine tailings. The results show that electric current could remove copper from watery tailing if the potential gradient was higher than 2V/cm during 21 days. With addition of sulphuric acid, the process was enhanced because the pH decreased to around 4......, and the copper by this reason was released in the solution. Furthermore, with acidic tailing the potential gradient was less than 2V/cm.The maximum copper removal reached in the anode side was 53% with addition of sulphuric acid in 21 days experiment at 20V using approximately 1.8kg mine tailing on dry basis...

  20. Analysis of Heavy-Tailed Time Series

    DEFF Research Database (Denmark)

    Xie, Xiaolei

    and expressed in terms of the parameters of the dependence structure, among others. Furthermore, we study an importance sampling method for estimating rare-event probabilities of multivariate heavy-tailed time series generated by matrix recursion. We show that the proposed algorithm is efficient in the sense......This thesis is about analysis of heavy-tailed time series. We discuss tail properties of real-world equity return series and investigate the possibility that a single tail index is shared by all return series of actively traded equities in a market. Conditions for this hypothesis to be true...... are identified. We study the eigenvalues and eigenvectors of sample covariance and sample auto-covariance matrices of multivariate heavy-tailed time series, and particularly for time series with very high dimensions. Asymptotic approximations of the eigenvalues and eigenvectors of such matrices are found...

  1. Injurious tail biting in pigs: how can it be controlled in existing systems without tail docking?

    Science.gov (United States)

    D'Eath, R B; Arnott, G; Turner, S P; Jensen, T; Lahrmann, H P; Busch, M E; Niemi, J K; Lawrence, A B; Sandøe, P

    2014-09-01

    Tail biting is a serious animal welfare and economic problem in pig production. Tail docking, which reduces but does not eliminate tail biting, remains widespread. However, in the EU tail docking may not be used routinely, and some 'alternative' forms of pig production and certain countries do not allow tail docking at all. Against this background, using a novel approach focusing on research where tail injuries were quantified, we review the measures that can be used to control tail biting in pigs without tail docking. Using this strict criterion, there was good evidence that manipulable substrates and feeder space affect damaging tail biting. Only epidemiological evidence was available for effects of temperature and season, and the effect of stocking density was unclear. Studies suggest that group size has little effect, and the effects of nutrition, disease and breed require further investigation. The review identifies a number of knowledge gaps and promising avenues for future research into prevention and mitigation. We illustrate the diversity of hypotheses concerning how different proposed risk factors might increase tail biting through their effect on each other or on the proposed underlying processes of tail biting. A quantitative comparison of the efficacy of different methods of provision of manipulable materials, and a review of current practices in countries and assurance schemes where tail docking is banned, both suggest that daily provision of small quantities of destructible, manipulable natural materials can be of considerable benefit. Further comparative research is needed into materials, such as ropes, which are compatible with slatted floors. Also, materials which double as fuel for anaerobic digesters could be utilised. As well as optimising housing and management to reduce risk, it is important to detect and treat tail biting as soon as it occurs. Early warning signs before the first bloody tails appear, such as pigs holding their tails tucked

  2. Estimation of the tail index for lattice-valued sequences

    DEFF Research Database (Denmark)

    Matsui, Muneya; Mikosch, Thomas Valentin; Tafakori, Laleh

    2013-01-01

    If one applies the Hill, Pickands or Dekkers–Einmahl–de Haan estimators of the tail index of a distribution to data which are rounded off one often observes that these estimators oscillate strongly as a function of the number k of order statistics involved.We study this phenomenon in the case of ...... of a Pareto distribution. We provide formulas for the expected value and variance of the Hill estimator and give bounds on k when the central limit theorem is still applicable. We illustrate the theory by using simulated and real-life data....

  3. Tail posture predicts tail biting outbreaks at pen level in weaner pigs

    DEFF Research Database (Denmark)

    Lahrmann, Helle Pelant; Hansen, Christian Fink; D'Eath, Rick

    2018-01-01

    Detecting a tail biting outbreak early is essential to reduce the risk of pigs getting severe tail damage. A few previous studies suggest that tail posture and behavioural differences can predict an upcoming outbreak. The aim of the present study was therefore to investigate if differences in tail...... posture and behaviour could be detected at pen level between upcoming tail biting pens (T-pens) and control pens (C-pens). The study included 2301 undocked weaner pigs in 74 pens (mean 31.1 pigs/pen; SD 1.5). Tails were scored three times weekly (wound freshness, wound severity and tail length) between 07......:00 h-14:00 h from weaning until a tail biting outbreak. An outbreak (day 0) occurred when at least four pigs had a tail damage, regardless of wound freshness. On average 7.6 (SD 4.3) pigs had a damaged tail (scratches + wound) in T-pens on day 0. Tail posture and behaviour (activity, eating...

  4. Effects of tail docking and docking length on neuroanatomical changes in healed tail tips of pigs

    DEFF Research Database (Denmark)

    Herskin, M. S.; Thodberg, K.; Jensen, Henrik Elvang

    2015-01-01

    In pig production, piglets are tail docked at birth in order to prevent tail biting later in life. In order to examine the effects of tail docking and docking length on the formation of neuromas, we used 65 pigs and the following four treatments: intact tails (n=18); leaving 75% (n=17); leaving 50......% (n=19); or leaving 25% (n=11) of the tail length on the pigs. The piglets were docked between day 2 and 4 after birth using a gas-heated apparatus, and were kept under conventional conditions until slaughter at 22 weeks of age, where tails were removed and examined macroscopically and histologically...... (1.0±0.2 v. 0; Piron cautery causes formation of neuromas in the outermost part of the tail tip. The presence of neuromas might lead to altered nociceptive thresholds, which need...

  5. Shake a tail feather: the evolution of the theropod tail into a stiff aerodynamic surface.

    Directory of Open Access Journals (Sweden)

    Michael Pittman

    Full Text Available Theropod dinosaurs show striking morphological and functional tail variation; e.g., a long, robust, basal theropod tail used for counterbalance, or a short, modern avian tail used as an aerodynamic surface. We used a quantitative morphological and functional analysis to reconstruct intervertebral joint stiffness in the tail along the theropod lineage to extant birds. This provides new details of the tail's morphological transformation, and for the first time quantitatively evaluates its biomechanical consequences. We observe that both dorsoventral and lateral joint stiffness decreased along the non-avian theropod lineage (between nodes Theropoda and Paraves. Our results show how the tail structure of non-avian theropods was mechanically appropriate for holding itself up against gravity and maintaining passive balance. However, as dorsoventral and lateral joint stiffness decreased, the tail may have become more effective for dynamically maintaining balance. This supports our hypothesis of a reduction of dorsoventral and lateral joint stiffness in shorter tails. Along the avian theropod lineage (Avialae to crown group birds, dorsoventral and lateral joint stiffness increased overall, which appears to contradict our null expectation. We infer that this departure in joint stiffness is specific to the tail's aerodynamic role and the functional constraints imposed by it. Increased dorsoventral and lateral joint stiffness may have facilitated a gradually improved capacity to lift, depress, and swing the tail. The associated morphological changes should have resulted in a tail capable of producing larger muscular forces to utilise larger lift forces in flight. Improved joint mobility in neornithine birds potentially permitted an increase in the range of lift force vector orientations, which might have improved flight proficiency and manoeuvrability. The tail morphology of modern birds with tail fanning capabilities originated in early ornithuromorph

  6. APPLICATION OF POSTFLOTATION TAILINGS IN HYDROENGINEERING STRUCTURES

    Directory of Open Access Journals (Sweden)

    Katarzyna Stefaniak

    2017-01-01

    Full Text Available Economic development stimulated by the increased demand for production of consumer goods and the growing human population result in increasing amounts of various wastes, including tailings. The mining industry in Poland, comprising also mining of non-ferrous metal ores, is a strategic branch of the national economy and at the same time a leading waste producer. Tailings management is a significant problem both in Poland and worldwide. Frequently considerable amounts of wastes are accumulated in mine spoil tips, in areas not always suitable for their deposition, thus leading to the degradation of the surrounding environment. At the huge volume of produced wastes their rational and economically viable management is becoming crucial. On the other hand, depletion of natural aggregate deposits is an important incentive to search for substitutes, which would be suitable for the development of road infrastructure or which could be used in earth structure engineering to construct hydroengineering objects. Since no profitable recovery technologies are available at present, tailings generated by copper mining are deposited in tailings storage facilities. The largest and at the same time the only currently operating facility in Poland is the Żelazny Most Mining Tailings Storage Facility, belonging to KGHM Polska Miedź S.A. The paper presents criteria for material quality and density imposed on the material embedded in the static core of the tailings pond dam. For this purpose studies were conducted to confirm applicability of sorted tailings as a material for the construction of earth structures.

  7. The evolution of tail weaponization in amniotes.

    Science.gov (United States)

    Arbour, Victoria M; Zanno, Lindsay E

    2018-01-31

    Weaponry, for the purpose of intraspecific combat or predator defence, is one of the most widespread animal adaptations, yet the selective pressures and constraints governing its phenotypic diversity and skeletal regionalization are not well understood. Here, we investigate the evolution of tail weaponry in amniotes, a rare form of weaponry that nonetheless evolved independently among a broad spectrum of life including mammals, turtles and dinosaurs. Using phylogenetic comparative methods, we test for links between morphology, ecology and behaviour in extant amniotes known to use the tail as a weapon, and in extinct taxa bearing osseous tail armaments. We find robust ecological and morphological correlates of both tail lashing behaviour and bony tail weaponry, including large body size, body armour and herbivory, suggesting these life-history parameters factor into the evolution of antipredator behaviours and tail armaments. We suggest that the evolution of tail weaponry is rare because large, armoured herbivores are uncommon in extant terrestrial faunas, as they have been throughout evolutionary history. © 2018 The Author(s).

  8. Tail-biting: a new perspective.

    Science.gov (United States)

    Taylor, Nina R; Main, David C J; Mendl, Mike; Edwards, Sandra A

    2010-11-01

    Tail-biting data from different studies are difficult to compare because a range of definitions of tail-biting behaviour and tail-biting lesions are used. Although records from abattoirs provide a large database, their usefulness is restricted as tail-biting is under-recorded and environmental and husbandry factors associated with the behaviour are unlikely to be known. Both farm and abattoir data provide no information on the number of pigs biting, only those bitten. Studying individual animals that tail-bite should give a better understanding of the pig's motivation to tail-bite and which of the components of its environment should be adjusted to improve welfare. This review examines the existing literature on tail-biting in pigs but considered from a new perspective using three different descriptive behavioural types, namely, 'two-stage', 'sudden-forceful' and 'obsessive', each of which may have different motivational bases. The article also considers the different environmental and husbandry factors which may affect each type of behaviour and discusses why this is such a complicated field and why it is often difficult to draw conclusions from available research. Copyright © 2009 Elsevier Ltd. All rights reserved.

  9. Engineering assessment of inactive uranium mill tailings

    Energy Technology Data Exchange (ETDEWEB)

    1981-07-01

    The Grand Junction site has been reevaluated in order to revise the October 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Grand Junction, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 1.9 million tons of tailings at the Grand Junction site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation are also factors. The eight alternative actions presented herein range from millsite and off-site decontamination with the addition of 3 m of stabilization cover material (Option I), to removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II through VIII). Cost estimates for the eight options range from about $10,200,000 for stabilization in-place to about $39,500,000 for disposal in the DeBeque area, at a distance of about 35 mi, using transportation by rail. If transportation to DeBeque were by truck, the cost estimated to be about $41,900,000. Three principal alternatives for the reprocessing of the Grand Junction tailings were examined: (a) heap leaching; (b) treatment at an existing mill; and (c) reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $200/lb by heap leach and $150/lb by conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery appears not to be economically attractive.

  10. Engineering assessment of inactive uranium mill tailings

    International Nuclear Information System (INIS)

    1981-07-01

    The Grand Junction site has been reevaluated in order to revise the October 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Grand Junction, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 1.9 million tons of tailings at the Grand Junction site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation are also factors. The eight alternative actions presented herein range from millsite and off-site decontamination with the addition of 3 m of stabilization cover material (Option I), to removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II through VIII). Cost estimates for the eight options range from about $10,200,000 for stabilization in-place to about $39,500,000 for disposal in the DeBeque area, at a distance of about 35 mi, using transportation by rail. If transportation to DeBeque were by truck, the cost estimated to be about $41,900,000. Three principal alternatives for the reprocessing of the Grand Junction tailings were examined: (a) heap leaching; (b) treatment at an existing mill; and (c) reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $200/lb by heap leach and $150/lb by conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery appears not to be economically attractive

  11. Modified Whale's tail technique for the management of bone-defect in anterior teeth.

    Science.gov (United States)

    Kuriakose, Anu; Ambooken, Majo; Jacob, Jayan; John, Priya

    2015-01-01

    The purpose of this case report is to describe the efficacy of a modified Whale's tail technique to achieve primary closure and thereby aid in regeneration of an interdental osseous defect between maxillary central incisors complicated by an aberrant frenal attachment. A healthy 32-year-old female patient reported with the complaint of spacing between her upper front teeth. Clinical examination revealed an aberrant frenum extending into the interdental papilla in relation to the central incisors. There was a 6 mm periodontal pocket in relation to the mesiopalatal aspect of maxillary left central incisor. Intraoral periapical radiograph showed vertical bone loss in relation to mesial aspect of maxillary left central incisor. A modified Whale's tail flap was employed to access the area. The defect was filled with an alloplastic graft. Six months postoperative review showed complete elimination of the pocket along with radiographic bone fill of the defect.

  12. Canopy openings and white-tailed deer influence the understory vegetation in mixed oak woodlots

    Science.gov (United States)

    Todd W. Bowersox; Gerald L. Storm; Walter M. Tzilkowski

    1995-01-01

    Effects of canopy opening and white-tailed deer on ground level vegetation are being assessed in south-central Pennsylvania. Herbaceous plants and woody seedlings are being monitored in three unevenaged, mixed oak woodlots at Gettysburg National Military Park. Canopy opening levels on 0.20 ha treatment units were closed (~100% canopy), small (50-60% canopy) and large (...

  13. Impacts of black-tailed prairie dog rodenticides on nontarget passerines

    Science.gov (United States)

    Anthony D. Apa; Daniel W. Uresk; Raymond L. Linder

    1991-01-01

    In 1983 zinc phosphide, strychnine with prebait, and strychnine without prebait were applied to black-tailed prairie dog (Cynomys Zudovicianus) colonies in west central South Dakota. Short-term (four days later) and long-term (one year later) impacts of the rodenticides on Horned Larks (Eremophila alpestris) and other...

  14. Black-tailed prairie dog populations one year after treatment with rodenticides

    Science.gov (United States)

    Anthony D. Apa; Daniel W. Uresk; Raymond L. Linder

    1990-01-01

    Three rodenticide treatments, zinc phosphide with prebait, strychnine with prebait, and strychnine without prebait, were applied to black-tailed prairie dog (Cynomys ludovicianus) colonies in west central South Dakota. Results were compared immediately posttreatment and for one year after application. Zinc phosphide was the most effective for...

  15. Cameco engineered tailings program: linking research with industrial processes for improved tailings performance

    International Nuclear Information System (INIS)

    Kotzer, T.; Hendry, M.J.

    2011-01-01

    The waste product from uranium mining and milling that generates the greatest public and regulatory concern is tailings. The tailings contain all of the mined material except uranium plus a host of processing reagents. These minerals and compounds have the potential to harm the local environment if not deposited in a fashion that is both geochemically and geotechnically stable. Environmental leadership impels Cameco Corporation to ensure that the methods used to dispose of tailings are at the forefront of best available technologies whereby tailings production results in a product with geotechnical and geochemical characteristics that minimize the environmental impact associated with long-term storage of this product. Cameco has developed an Engineered Tailings (ET) program to ensure optimization of long-term tailings performance and minimal impacts of elements of concern (EOCs) to the receiving environment, regardless of the ore being milled. Within this program chemical and physical performance of tailings from geochemical and geotechnical investigations and baseline environmental data, integrated with regulatory requirements and corporate commitments, will be used to evaluate and set criteria for mill- and tailings management facilities-based chemical and physical tailings characteristics, identify key knowledge gaps, prioritize areas of concern and implement appropriate responses. This paper provides an overview of the Engineered Tailings program, the research being conducted as part of the ET program, and how it links with present and future Cameco operations. (author)

  16. Cameco engineered tailings program: linking applied research with industrial processes for improved tailings performance

    International Nuclear Information System (INIS)

    Kotzer, T.G.

    2010-01-01

    'Full text:' Mine tailings at Cameco's operations are by-products of milling uranium ore having variable concentrations of uranium, metals, oxyanions and trace elements or elements of concern (EOC). Cameco has undertaken an Engineered Tailings (ET) program to optimize tailings performance and minimize environmental EOC impacts, regardless of the milled ore source. Applied geochemical and geotechnical tailings research is key within the ET program. In-situ drilling and experimental programs are used to understand long-term tailings behaviour and help validate source term predictions. Within this, the ET program proactively aids in the development of mill-based processes for production of tailings having improved long-term stability. (author)

  17. White-tailed deer in the Midwest.

    Science.gov (United States)

    USDA FS

    1970-01-01

    Discusses the present status and future prospects of the nonyarding white-tailed deer population in the Midwestern United States. Range appraisal, habitat, harvest regulation, and population control are included.

  18. Unique structural features facilitate lizard tail autotomy.

    Directory of Open Access Journals (Sweden)

    Kristian W Sanggaard

    Full Text Available Autotomy refers to the voluntary shedding of a body part; a renowned example is tail loss among lizards as a response to attempted predation. Although many aspects of lizard tail autotomy have been studied, the detailed morphology and mechanism remains unclear. In the present study, we showed that tail shedding by the Tokay gecko (Gekko gecko and the associated extracellular matrix (ECM rupture were independent of proteolysis. Instead, lizard caudal autotomy relied on biological adhesion facilitated by surface microstructures. Results based on bio-imaging techniques demonstrated that the tail of Gekko gecko was pre-severed at distinct sites and that its structural integrity depended on the adhesion between these segments.

  19. On Estimation and Testing for Pareto Tails

    Czech Academy of Sciences Publication Activity Database

    Jordanova, P.; Stehlík, M.; Fabián, Zdeněk; Střelec, L.

    2013-01-01

    Roč. 22, č. 1 (2013), s. 89-108 ISSN 0204-9805 Institutional support: RVO:67985807 Keywords : testing against heavy tails * asymptotic properties of estimators * point estimation Subject RIV: BB - Applied Statistics, Operational Research

  20. Electrodialytic Remediation of Copper Mine Tailings

    DEFF Research Database (Denmark)

    Hansen, H.K.; Rojo, A.; Ottosen, L.M.

    2012-01-01

    This work compares and evaluates sixteen electrodialytic laboratory remediation experiments on copper mine tailings. Different parameters were analysed, such as remediation time, addition of desorbing agents, and the use of pulsed electrical fields.......This work compares and evaluates sixteen electrodialytic laboratory remediation experiments on copper mine tailings. Different parameters were analysed, such as remediation time, addition of desorbing agents, and the use of pulsed electrical fields....

  1. Unique Structural Features Facilitate Lizard Tail Autotomy

    DEFF Research Database (Denmark)

    Sanggaard, Kristian Wejse; Danielsen, C. C.; Wogensen, L.

    2012-01-01

    that tail shedding by the Tokay gecko (Gekko gecko) and the associated extracellular matrix (ECM) rupture were independent of proteolysis. Instead, lizard caudal autotomy relied on biological adhesion facilitated by surface microstructures. Results based on bio-imaging techniques demonstrated that the tail...... of Gekko gecko was pre-severed at distinct sites and that its structural integrity depended on the adhesion between these segments....

  2. The Sodium Tail of the Moon

    Science.gov (United States)

    Matta, M.; Smith, S.; Baumgardner, J.; Wilson, J.; Martinis, C.; Mendillo, M.

    2009-01-01

    During the few days centered about new Moon, the lunar surface is optically hidden from Earth-based observers. However, the Moon still offers an observable: an extended sodium tail. The lunar sodium tail is the escaping "hot" component of a coma-like exosphere of sodium generated by photon-stimulated desorption, solar wind sputtering and meteoroid impact. Neutral sodium atoms escaping lunar gravity experience solar radiation pressure that drives them into the anti-solar direction forming a comet-like tail. During new Moon time, the geometry of the Sun, Moon and Earth is such that the anti-sunward sodium flux is perturbed by the terrestrial gravitational field resulting in its focusing into a dense core that extends beyond the Earth. An all-sky camera situated at the El Leoncito Observatory (CASLEO) in Argentina has been successfully imaging this tail through a sodium filter at each lunation since April 2006. This paper reports on the results of the brightness of the lunar sodium tail spanning 31 lunations between April 2006 and September 2008. Brightness variability trends are compared with both sporadic and shower meteor activity, solar wind proton energy flux and solar near ultra violet (NUV) patterns for possible correlations. Results suggest minimal variability in the brightness of the observed lunar sodium tail, generally uncorrelated with any single source, yet consistent with a multi-year period of minimal solar activity and non-intense meteoric fluxes.

  3. Canadian experience with uranium tailings disposal

    International Nuclear Information System (INIS)

    Culver, K.B.

    1982-06-01

    During the first years of uranium production in Canada uranium tailings were discharged directly into valleys or lakes near the mill. Treatment with barium chloride to precipitate radium began in 1965 at the Nordic Mine at Elliot Lake, Ontario. In the mid-60s and early 70s water quality studies indicated that discharges from uranium tailings areas were causing degradation to the upper part of the Serpent River water system. Studies into acid generation, revegetation, and leaching of radium were initiated by the mining companies and resulted in the construction of treatment plants at a number of sites. Abandoned tailings sites were revegetated. At hearings into the expansion of the Elliot Lake operations the issue of tailings management was a major item for discussion. As a result federal and provincial agencies developed guidelines for the siting and development of urnaium tailings areas prior to issuing operating licences. Western Canadian uranium producers do not have the acid generation problem of the Elliot Lake operations. The Rabbit Lake mill uses settling ponds followed by filtration. High-grade tailings from Cluff Lake are sealed in concrete and buried. Uranium producers feel that the interim criteria developed by the Atomic Energy Control Board, if adopted, would have a harmful effect on the viability of the Canadian uranium industry

  4. FARADAY ROTATION IN THE TAIL OF THE PLANETARY NEBULA DeHt 5

    International Nuclear Information System (INIS)

    Ransom, R. R.; Kothes, R.; Wolleben, M.; Landecker, T. L.

    2010-01-01

    We present 1420 MHz polarization images of a 5 0 x 5 0 region around the planetary nebula (PN) DeHt 5. The images reveal narrow Faraday-rotation structures on the visible disk of DeHt 5, as well as two wider, tail-like, structures 'behind' DeHt 5. Though DeHt 5 is an old PN known to be interacting with the interstellar medium (ISM), a tail has not previously been identified for this object. The innermost tail is ∼3 pc long and runs away from the northeast edge of DeHt 5 in a direction roughly opposite that of the sky-projected space velocity of the white dwarf central star, WD 2218+706. We believe this tail to be the signature of ionized material ram-pressure stripped and deposited downstream during a >74,000 yr interaction between DeHt 5 and the ISM. We estimate the rotation measure (RM) through the inner tail to be -15 ± 5 rad m -2 , and, using a realistic estimate for the line-of-sight component of the ISM magnetic field around DeHt 5, derive an electron density in the inner tail of n e = 3.6 ± 1.8 cm -3 . Assuming the material is fully ionized, we estimate a total mass in the inner tail of 0.68 ± 0.33 M sun and predict that 0.49 ± 0.33 M sun was added during the PN-ISM interaction. The outermost tail consists of a series of three roughly circular components, which have a collective length of ∼11.0 pc. This tail is less conspicuous than the inner tail and may be the signature of the earlier interaction between the WD 2218+706 asymptotic giant branch (AGB) progenitor and the ISM. The results for the inner and outer tails are consistent with hydrodynamic simulations and may have implications for the PN missing-mass problem as well as for models which describe the impact of the deaths of intermediate-mass stars on the ISM.

  5. Dewatering Behaviour of Fine Oil Sands Tailings : An Experimental Study

    NARCIS (Netherlands)

    Yao, Y.

    2016-01-01

    Oil sands tailings are a warm aqueous suspension of sand, silt, clay, residual bitumen and naphtha. The tailings are hydraulically transported and stored in tailing ponds where they segregate, with the sand settling from suspension forming beaches and the remaining tailings flowing to the middle of

  6. Social Cost of Tail Loss in Uta stansburiand.

    Science.gov (United States)

    Fox, S F; Rostker, M A

    1982-11-12

    Tail removal from dominant juvenile Uta stansburiana resulted in a decrease in social status in dyadic encounters. Most lizards were affected after removal of two-thirds of their tails. In some pairs, dominant lizards lost status after removal of one-third of their tails but regained dominance after the other member of the pair lost two-thirds of its tail. Tail loss in nature may impose a social handicap to successful home range acquisition and thereby increase risk of death.

  7. Distinct hydrophobic “patches” in the N- and C-tails of beta-catenin contribute to nuclear transport

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Manisha; Jamieson, Cara; Lui, Christina [Center for Cancer Research, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145 (Australia); Henderson, Beric R., E-mail: beric.henderson@sydney.edu.au [Center for Cancer Research, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145 (Australia)

    2016-11-01

    β-catenin is a key mediator of Wnt signaling and its deregulated nuclear accumulation can drive cancer progression. While the central armadillo (Arm) repeats of β-catenin stimulate nuclear entry, the N- and C-terminal “tail” sequences are thought to regulate turnover and transactivation. We show here that the N- and C-tails are also potent transport sequences. The unstructured tails of β-catenin, when individually fused to a GFP-reporter, could enter and exit the nucleus rapidly in live cells. Proximity ligation assays and pull-down assays identified a weak interaction between the tail sequences and the FG-repeats of nucleoporins, consistent with a possible direct translocation of β-catenin through the nuclear pore complex. Extensive alanine mutagenesis of the tail sequences revealed that nuclear translocation of β-catenin was dependent on specific uniformly distributed patches of hydrophobic residues, whereas the mutagenesis of acidic amino acids had no effect. Moreover, the mutation of hydrophobic patches within the N-tail and C-tail of full length β-catenin reduced nuclear transport rate and diminished its ability to activate transcription. We propose that the tail sequences can contribute to β-catenin transport and suggest a possible similar role for hydrophobic unstructured regions in other proteins. - Highlights: • We show that the N- and C-tails of beta-catenin possess nuclear transport activity. • Nuclear transport of the N- or C-tails requires specific hydrophobic amino acids. • Mutagenesis of the N-terminus diminished nuclear entry of full-length beta-catenin. • We propose the N-tail contributes to beta-catenin nuclear entry and transactivation.

  8. Single-Tailed Lipidoids Enhance the Transfection Activity of Their Double-Tailed Counterparts.

    Science.gov (United States)

    Wu, Yihang; Li, Linxian; Chen, Qing; Su, Yi; Levkin, Pavel A; Davidson, Gary

    2016-01-11

    Cationic lipid-like molecules (lipidoids) are widely used for in vitro and in vivo gene delivery. Nearly all lipidoids developed to date employ double-tail or multiple-tail structures for transfection. Single-tail lipidoids are seldom considered for transfection as they have low efficiency in gene delivery. So far, there is no detailed study on the contribution to transfection efficiency of single-tail lipidoids when combined with standard double-tail lipidoids. Here, we use combinatorial chemistry to synthesize 17 double-tail and 17 single-tail lipidoids using thiol-yne and thiol-ene click chemistry, respectively. HEK 293T cells were used to analyze transfection efficiency by fluorescence microscopy and calculated based on the percentage of cells transfected. The size and zeta potential of liposomes and lipoplexes were characterized by dynamic light scattering (DLS). Intracellular DNA delivery and trafficking was further examined using confocal microscopy. Our study shows that combining single with double-tail lipidoids increases uptake of lipoplexes, as well as cellular transfection efficiency.

  9. Generalized processor sharing with light-tailed and heavy-tailed input

    NARCIS (Netherlands)

    Borst, Sem; Mandjes, M.R.H.; van Uitert, Miranda

    2003-01-01

    We consider a queue fed by a mixture of light-tailed and heavy-tailed traffic. The two traffic flows are served in accordance with the generalized processor sharing (GPS) discipline. GPS-based scheduling algorithms, such as weighted fair queueing, have emerged as an important mechanism for achieving

  10. Tailings neutralization and other alternatives for immobilizing toxic materials in tailings. Final report

    International Nuclear Information System (INIS)

    Opitz, B.E.; Sherwood, D.R.; Dodson, M.E.; Serne, R.J.

    1985-09-01

    This document, ''Tailing Neutralization and Other Alternatives for Immobilizing Toxic Materials in Tailings,'' is the final report in a series of six. It summarizes research completed since the beginning of the project. Three subtasks are included: Subtask A - Neutralization Methods Selection; Subtask B - Laboratory Analysis; and Subtask C - Field Testing. Subtask A reviews treatment processes from other industries to evaluate whether current waste technology from other fields is applicable to the uranium industry. This task also identifies several reagents that were tested for their effectiveness in treating acidic tailings and tailings solution in order to immobilize the contaminants associated with the acid waste. Subtask B describes the laboratory batch and column treatment studies performed on solid waste tailings and tailings solutions over the course of the project. The evaluation of several reagents identified in Subtask A was based on three criteria: (1) treated effluent water quality; (2) neutralized sludge handling and hydraulic properties; and (3) reagent costs and acid neutralizing efficiency. Subtask C presents a field demonstration plan that will evaluate the effectiveness, costs, and benefits of neutralizing acidic uranium mill tailings solution to reduce the potential leaching of toxic trace metals, radionuclides, and macro ions from a tailings impoundment. Details of the related research can be found in the documents listed in the ''Previous Documents in Series.'' 43 refs., 9 figs., 46 tabs

  11. Attitudes of Dutch Pig Farmers Towards Tail Biting and Tail Docking

    NARCIS (Netherlands)

    Bracke, M.B.M.; Lauwere, de C.C.; Wind, S.M.M.; Zonderland, J.J.

    2013-01-01

    The Dutch policy objective of a fully sustainable livestock sector without mutilations by 2023 is not compatible with the routine practice of tail docking to minimize the risk of tail biting. To examine farmer attitudes towards docking, a telephone survey was conducted among 487 conventional and 33

  12. Tail Asymptotics for the Sum of two Heavy-tailed Dependent Risks

    DEFF Research Database (Denmark)

    Albrecher, H.; Asmussen, Søren

    Let X1,X2 denote positive exchangable heavy-tailed random variables with continuous marginal distribution function F. The asymptotic behavior of the tail of X1 + X2 is studied in a general copula framework and some bounds and extremal properties are provided. For more specific assumptions on F an...

  13. Assessment of the underground disposal of tailings

    International Nuclear Information System (INIS)

    Hutt, N.M.; Morin, K.A.

    1995-06-01

    The Atomic Energy Control Board (AECB) of Canada is facing the issue of long-term disposal of uranium tailings. One option that has not been examined in sufficient detail for the AECB is the retrieval of tailings from surface impoundments and subsequent placement of those tailings in underground workings of mines. This report is structured like a catalogue of facts and information, with each paragraph presenting some concept, concern, theory, or case study involving the retrieval or placement of tailings. All relevant information, findings, interpretations, conclusions, and recommendations gathered during the course of this study are included. The Table of Contents illustrates the striking number of relevant topics and acts like a flowchart or checklist to ensure that an underground-disposal submission by a mining company has addressed relevant topics. This report explains in detail the implications of disturbing surface-impounded tailings for the purpose of placing only some of the volume underground. The cumulative environmental, safety, and monetary liabilities of such a partial scheme can be discouraging in some cases. (author). 244 refs., 47 tabs., 17 figs

  14. Grouting of uranium mill tailings piles

    International Nuclear Information System (INIS)

    Boegly, W.J. Jr.; Tamura, T.; Williams, J.D.

    1984-03-01

    A program of remedial action was initiated for a number of inactive uranium mill tailings piles. These piles result from mining and processing of uranium ores to meet the nation's defense and nuclear power needs and represent a potential hazard to health and the environment. Possible remedial actions include the application of covers to reduce radon emissions and airborne transport of the tailings, liners to prevent groundwater contamination by leachates from the piles, physical or chemical stabilization of the tailings, or moving the piles to remote locations. Conventional installation of liners would require excavation of the piles to emplace the liner; however, utilization of grouting techniques, such as those used in civil engineering to stabilize soils, might be a potential method of producing a liner without excavation. Laboratory studies on groutability of uranium mill tailings were conducted using samples from three abandoned piles and employing a number of particulate and chemical grouts. These studies indicate that it is possible to alter the permeability of the tailings from ambient values of 10 -3 cm/s to values approaching 10 -7 cm/s using silicate grouts and to 10 -8 cm/s using acrylamide and acrylate grouts. An evaluation of grouting techniques, equipment required, and costs associated with grouting were also conducted and are presented. 10 references, 1 table

  15. Hydrogeochemical studies on WTC uranium tailings lysimeters

    International Nuclear Information System (INIS)

    1983-03-01

    In 1974, Environment Canada initiated a series of tailings lysimeter studies at the Wastewater Technology Centre (WTC) in Burlington, Ontario, to examine the leachability of radionuclides and major constituents (TDS, pH) from uranium mill tailings. In addition, the study attempted to assess the effect of two leachate control methods (chemical fixation and vegetation) upon the characteristics of tailings leachate. In 1982 IEC Beak Consultants Ltd. was retained to conduct additional physical/chemical characterization of the tailings solids and some leachate samples. This information, together with the existing data, was then used to develop a conceptual model with which to try to explain the behaviour of the tailings during the leaching of the lysimeters. The specific tasks undertaken included: multi-parameter analysis of leachates collected from 4 lysimeters over the last 1 1/2 years of operation; physical/chemical characterization of the final lysimeter solids including grain size, bulk density, sulphate and carbonate con-tent; use of Scanning Electron Microscopy (SEM) coupled with X-ray Emission (XRE) spectroscopy, plus Mossbauer spectroscopy to characterize surface precipitates and iron speciation respectively; chemical equilibrium modelling on leachates to estimate controlling species in radioisotope and TDS release

  16. Remote sensing to monitor uranium tailing sites

    International Nuclear Information System (INIS)

    1992-02-01

    This report concerns the feasibility of using remotely-sensed data for long-term monitoring of uranium tailings. Decommissioning of uranium mine tailings sites may require long-term monitoring to confirm that no unanticipated release of contaminants occurs. Traditional ground-based monitoring of specific criteria of concern would be a significant expense depending on the nature and frequency of the monitoring. The objective of this study was to evaluate whether available remote-sensing data and techniques were applicable to the long-term monitoring of tailings sites. This objective was met by evaluating to what extent the data and techniques could be used to identify and discriminate information useful for monitoring tailings sites. The cost associated with obtaining and interpreting this information was also evaluated. Satellite and aircraft remote-sensing-based activities were evaluated. A monitoring programme based on annual coverage of Landsat Thematic Mapper data is recommended. Immediately prior to and for several years after decommissioning of the tailings sites, airborne multispectral and thermal infrared surveys combined with field verification data are required in order to establish a baseline for the long-term satellite-based monitoring programme. More frequent airborne surveys may be required if rapidly changing phenomena require monitoring. The use of a geographic information system is recommended for the effective storage and manipulation of data accumulated over a number of years

  17. Evaluation of the grass mixture (Faestuca Rubra, Cynodon Dactylon, Lolium Multiflorum and Pennisetum sp.) as Sb phyto-stabilizer in tailings and Sb-rich soils.

    Science.gov (United States)

    Aurora Armienta, M.; Beltrán-Villavicencio, Margarita; Ruiz-Villalobos, Carlos E.; Labastida, Israel; Ceniceros, Nora; Cruz, Olivia; Aguayo, Alejandra

    2017-04-01

    Green house experiments were carried out to evaluate the growth and Sb assimilation of a grass assemblage: Faestuca Rubra, Cynodon Dactylon, Lolium Multiflorum and Pennisetum sp, in tailings and Sb-rich soils. Tailings and soil samples were obtained at the Mexican historical mining zone of Zimapán, Central México. More than 6 tailings impoundments are located at the town outskirts and constitute a contamination source from windblown and waterborne deposit on soils, besides acid mine drainage. Four substrates were used in the experiments: 100% tailings, 20% tailings + 80% soil, 50% tailings + 50% soil , and a soil sample far from tailings as a background. Concentrations of Sb ranged from 310 mg/kg to 413 mg/kg in tailings. A pH of 7.43, 1.27% organic matter, and high concentrations of N, K and P indicated adequate conditions for plant growth. The grass assemblage was raised during 21 days as indicated by OECD (Organisation for Economic Co-operation and Development) Guideline 208 Terrestrial Plant Test: Seedling Emergence and Seedling Growth Test. The highest Sb concentrations were measured in plants grown on tailings with 139 mg/kg in the aerial part and 883 mg/kg in roots. Concentrations of Sb decreased as the proportion of tailings diminished with 22.1 mg/kg in the aerial part and 10 mg/kg in roots corresponding to the plants grown in the 20 % tailings + 80% soil . Bioaccumulation (BAC) and bioconcentration factors (BF) of plants grown on tailings (BAC= 0.42, BCF=3.93) indicated their suitability as a phyto-stabilization option. The grass mixture may be thus applied to control windblown particulate tailings taking advantage to their tolerance to high Sb levels.

  18. An assessment of the long term interaction of uranium tailings with the natural environment

    International Nuclear Information System (INIS)

    Lush, D.; Fletcher, R.; Goode, J.; Jurgens, T.

    1978-01-01

    Current investigations of methods for the management of tailings at uranium mill sites raise pertinent questions as to accuracy of our identification of potential hazards and their causes. Of particular relevance are the physical-chemical geomechanisms which may lead to the dispersion of contaminants into the environment and eventually into the food chain. This paper looks at present practices of uranium mill tailings storage in the light of 'Perpetual Care' management concepts and requirements. It examines the potential geomechanisms of transport that would be acting on the tailing over the next millenia. Interesting parallels are drawn between these mechanisms and those geomechanisms which led to the formation of many of the original ore deposits. Central to the substance of this paper is a study currently being undertaken for the Atomic Energy Control Board of Canada. Selected elements to this study will be presented in the paper together with a discussion of relevant peripheral issues

  19. Uranium mine and mill tailings - Liabilities in the European Union

    International Nuclear Information System (INIS)

    Hilden, Wolfgang; Murphy, Simon; Vrijen, Jan

    2007-01-01

    Available in abstract form only. Full text of publication follows: Uranium mining and milling has taken place on large scale in the Member States of the European Union (EU) for some 60 years. Although, compared to mining, milling activities are normally concentrated in fewer locations, this can still result in a relatively large number of disposal sites for the tailings, compared to other radioactive wastes. In addition these sites are also quite large, in terms of both volume and surface area. Coupled with the residual uranium in the tailings together with other radionuclides, heavy metals, chemicals etc this results in an environmental legacy continuing far into the future. Often during production no or little provision has been made for the closure, remediation and future supervision of such sites. In 1996 the European Commission funded an inventory of uranium mining and milling liabilities in nine Central and Eastern European Countries. Additionally, pilot projects were funded to carry out remediation activities at several sites. Almost ten years later the Commission has identified the need to address the situation of these large liabilities in all EU Member States and to assess the progress made in remediation of the sites, especially in view of the closure of almost all mining activities in Europe. The Commission study has identified the current tailings liabilities in Europe, their status, the future plans for these sites and the hazards that continue to be associated with them. It is clear that although considerable progress has been made in recent years, much work remains to be carried out in the areas of remediation, and ensuring the long-term safety of many of the identified objects. The paper presents the main findings of the study, as well as the challenges identified to ensure long-term safety of these wastes. (authors)

  20. Tree growth studies on uranium mill tailings

    International Nuclear Information System (INIS)

    Murray, D.R.; Turcotte, M.

    1982-01-01

    Coniferous trees planted in 1974 and deciduous species that have volunteered since 1970 on uranium mill tailings that had been stabilized to varying degrees using limestone and vegetation were evaluated. Their survival and growth rates were compared with those from other investigations. Competition for light appears to be a major contributor to mortality. Differences in soil moisture conditions under a tree stand as compared to those under a grass sward are potentially significant enough to affect the tailings hydrology and effluent contamination. Recommendations include planting seeds of deciduous species or deciduous and coniferous seedlings on strips of freshly disturbed tailings. The disturbed strips would provide reduced competition for the initial year and assist in tree survival. The planting of block stands of coniferous or deciduous trees would be useful for evaluating the hydrological impact of the trees as compared to the present grass sward

  1. Field evaporation test of uranium tailings solution

    International Nuclear Information System (INIS)

    Chandler, B.L.; Shepard, T.A.; Stewart, T.A.

    1985-01-01

    A field experiment was performed to observe the effect on evaporation rate of a uranium tailings impoundment pond water as salt concentration of the water increased. The duration of the experiment was long enough to cause maximum salt concentration of the water to be attained. The solution used in the experiment was tailings pond water from an inactive uranium tailings disposal site in the initial stages of reclamation. The solution was not neutralized. The initial pH was about 1.0 decreasing to a salt gel at the end of the test. The results of the field experiment show a gradual and slight decrease in evaporation efficiency. This resulted as salt concentrations increased and verified the practical effectiveness of evaporation as a water removal method. In addition, the physical and chemical nature of the residual salts suggest that no long-term stability problem would likely result due to their presence in the impoundment during or after reclamation

  2. International experience in tailings pond remediation

    International Nuclear Information System (INIS)

    Robertson, A.MacG.

    2001-01-01

    Tailings pond remediation is required primarily on mine closure. While mining is an ancient industry, requirement for mine facility remediation is a comparatively new development. Requirement for remediation has come about partly as a result of mans awareness of the environmental impacts of mining and his desire to minimize this, partly, as a result of the ever-increasing scale and production rates of tailings generation and the resulting increased environmental impacts and safety risks. The paper starts with a review of the evolution of mans intolerance of environmental impacts from tailings production and the assignment of liability to remediate such impacts. Many of the tailings ponds currently undergoing remediation were designed and constructed using methods and technology that would be considered inappropriate for new impoundments being designed and developed today. The paper reviews the history of tailings impoundment design and construction practice and the resulting inherent deficiencies that must be remediated. Current practices and future trends in tailings pond remediation are reviewed. The evolution of regulatory requirements is not only in terms of technical and safety criteria, but also in terms of financial and political risk. Perhaps the most substantive driver of risk management is today the requirement for corporate governance at mining company board level and oversight of new project development in the underdeveloped countries by the large financial institutions responsible for funding projects. Embarrassment in the public eye and punishment in the stock markets for poor environmental and safety performance is driving the need for efficient and effective risk management of potential impacts and the remediation to avoid these. A basis for practical risk management is described. (orig.)

  3. Density Structure of the Martian Tail

    Science.gov (United States)

    Nauth, M.; Fowler, C. M.; Andersson, L.; Pilinski, M.; DiBraccio, G. A.

    2017-12-01

    The lack of a significant, global dipole magnetic field at Mars results in a more comet-­-like interaction between the planet and the solar wind. Subsequently, the tail region is highly dynamic and variable in nature. The majority of plasma in the Martian tail is low density (a few cm-3) and warm (several eV). There are times, however, when magnetic flux tubes connected to the ionosphere are configured such that colder (effects of the local magnetic field orientation on such events.

  4. Dynamics of Histone Tails within Chromatin

    Science.gov (United States)

    Bernier, Morgan; North, Justin; Page, Michael; Jaroniec, Christopher; Hammel, Christopher; Poirier, Michael

    2012-02-01

    Genetic information in humans is encoded within DNA molecules that is wrapped around histone octamer proteins and compacted into a highly conserved structural polymer, chromatin. The physical and material properties of chromatin appear to influence gene expression by altering the accessibility of proteins to the DNA. The tails of the histones are flexible domains that are thought to play a role in regulating DNA accessibility and compaction; however the molecular mechanisms for these phenomena are not understood. I will present CW-EPR studies on site directed spin labeled nucleosomes that probe the structure and dynamics of these histone tails within nucleosomes.

  5. The mechanism of DNA ejection in the Bacillus anthracis spore-binding phage 8a revealed by cryo-electron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Xiaofeng [Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Houston, TX 77030 (United States); Walter, Michael H. [Department of Biology, University of Northern Iowa, Cedar Falls, IA 50614 (United States); Paredes, Angel [Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Houston, TX 77030 (United States); Morais, Marc C., E-mail: mcmorais@utmb.edu [Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555 (United States); Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555 (United States); Liu, Jun, E-mail: Jun.Liu.1@uth.tmc.edu [Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Houston, TX 77030 (United States)

    2011-12-20

    The structure of the Bacillus anthracis spore-binding phage 8a was determined by cryo-electron tomography. The phage capsid forms a T = 16 icosahedron attached to a contractile tail via a head-tail connector protein. The tail consists of a six-start helical sheath surrounding a central tail tube, and a structurally novel baseplate at the distal end of the tail that recognizes and attaches to host cells. The parameters of the icosahedral capsid lattice and the helical tail sheath suggest protein folds for the capsid and tail-sheath proteins, respectively, and indicate evolutionary relationships to other dsDNA viruses. Analysis of 2518 intact phage particles show four distinct conformations that likely correspond to four sequential states of the DNA ejection process during infection. Comparison of the four observed conformations suggests a mechanism for DNA ejection, including the molecular basis underlying coordination of tail sheath contraction and genome release from the capsid.

  6. Evaluation of Soils Contained in Mineral Tailings at Junin Lake

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Javier [Instituto de Investigacion de Fisica, Av. Universitaria s/n, Lima (Peru); Fabian, Julio; Vela, Mariano [Instituto Peruano de Energia Nuclear, Av. Canada 1470, San Borja, Lima (Peru)

    2008-07-01

    The Junin National Reserve is located between the provinces of Junin and Pasco, Sierra Central, high land of Peru. It was analyzed 20 samples from different geographic locations soil of the Reserve. The results showed us that there are pollutants minerals very harmful to the environment because of some of the centers miners deposited the tailings in the vicinity of the nature reserve. The techniques used for characterization of mineralogical soil were: neutron activation analysis, x-ray fluorescence and spectroscopy Moessbauer by transmission. The analysis done by the method of X-ray fluorescence indicate the presence of Rubidium, tungsten, calcium, iron, nickel, copper, zinc, gold and zirconium. With spectroscopy Moessbauer technique was observed the presence a higher proportion of paramagnetic iron; while thanks to neutron activation analysis, besides these elements, it was observed the presence of Molybdenum, Manganese and a high concentration of arsenic. (authors)

  7. Evaluation of Soils Contained in Mineral Tailings at Junin Lake

    International Nuclear Information System (INIS)

    Gomez, Javier; Fabian, Julio; Vela, Mariano

    2008-01-01

    The Junin National Reserve is located between the provinces of Junin and Pasco, Sierra Central, high land of Peru. It was analyzed 20 samples from different geographic locations soil of the Reserve. The results showed us that there are pollutants minerals very harmful to the environment because of some of the centers miners deposited the tailings in the vicinity of the nature reserve. The techniques used for characterization of mineralogical soil were: neutron activation analysis, x-ray fluorescence and spectroscopy Moessbauer by transmission. The analysis done by the method of X-ray fluorescence indicate the presence of Rubidium, tungsten, calcium, iron, nickel, copper, zinc, gold and zirconium. With spectroscopy Moessbauer technique was observed the presence a higher proportion of paramagnetic iron; while thanks to neutron activation analysis, besides these elements, it was observed the presence of Molybdenum, Manganese and a high concentration of arsenic. (authors)

  8. Lateral movements of a massive tail influence gecko locomotion: an integrative study comparing tail restriction and autotomy.

    Science.gov (United States)

    Jagnandan, Kevin; Higham, Timothy E

    2017-09-07

    Tails are an intricate component of the locomotor system for many vertebrates. Leopard geckos (Eublepharis macularius) possess a large tail that is laterally undulated during steady locomotion. However, the tail is readily shed via autotomy, resulting in the loss of tail function, loss in body mass, and a cranial shift in the center of mass. To elucidate the function of tail undulations, we investigated changes in limb kinematics after manipulating the tail artificially by restricting tail undulations and naturally by removing the tail via autotomy. Restricting tail undulations resulted in kinematic adjustments similar to those that occur following tail autotomy, characterized by more flexed hind limb joints. These data suggest that effects of autotomy on locomotion may be linked to the loss of tail movements rather than the loss of mass or a shift in center of mass. We also provide empirical support for the link between lateral tail undulations and step length through the rotation of the pelvic girdle and retraction of the femur. Restriction and autotomy of the tail limits pelvic rotation, which reduces femur retraction and decreases step length. Our findings demonstrate a functional role for tail undulations in geckos, which likely applies to other terrestrial vertebrates.

  9. Electrokinetic remediation of copper mine tailings

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Rojo, Adrián; Ottosen, Lisbeth M.

    2007-01-01

    in sulphuric acidified tailings) without bipolar electrodes to 42% when bipolar electrodes were implemented. Furthermore, the results showed that in this system sulphuric acid addition prior to remediation was better than citric acid addition. In addition, applying a too strong electric field (even...

  10. Zone-tailed Hawk (Buteo albonotatus)

    Science.gov (United States)

    Scott H. Stoleson; Giancarlo Sadoti

    2010-01-01

    The Zone-tailed Hawk (Buteo albonotatus) might well be dubbed "the Great Pretender" because it so closely resembles the ubiquitous Turkey Vulture (Cathartes aura) in appearance and behavior as to be frequently mistaken for it. In the border regions where it lives, it may be confused as well with another "Mexican" raptor, the Common Black-Hawk (...

  11. Experiments on a Tail-wheel Shimmy

    Science.gov (United States)

    Harling, R; Dietz, O

    1954-01-01

    Model tests on the "running belt" and tests with a full-scale tail wheel were made on a rotating drum as well as on a runway in order to investigate the causes of the undesirable shimmy phenomena frequently occurring on airplane tail wheels, and the means of avoiding them. The small model (scale 1:10) permitted simulation of the mass, moments of inertia, and fuselage stiffness of the airplane and determination of their influence on the shimmy, whereas by means of the larger model with pneumatic tires (scale 1:2) more accurate investigations were made on the tail wheel itself. The results of drum and road tests show good agreement with one another and with model values. Detailed investigations were made regarding the dependence of the shimmy tendency on trail, rolling speed, load, size of tires, ground friction,and inclination of the swivel axis; furthermore, regarding the influence of devices with restoring effect on the tail wheel, and the friction damping required for prevention of shimmy. Finally observations from slow-motion pictures are reported and conclusions drawn concerning the influence of tire deformation.

  12. Aging geomembranes in uranium tailings leachate

    International Nuclear Information System (INIS)

    Mitchell, D.H.

    1984-01-01

    Pacific Northwest Laboratory (PNL) is performing a study to provide the US Nuclear Regulatory Commission (NRC) with a database to support licensing of uranium mill tailings ponds with geomembranes. As part of this study, geomembranes have been aged under conditions closely approximating those of uranium mill tailings ponds with acidic leachate. The aging procedure and results of tests with high density polyethylene (HDPE) and polyvinyl chloride (PVC) are presented. No degradation products were detected in the HDPE or the leachate. We expect that HDPE will not suffer significant chemical attack by uranium tailings and acidic leachate over the active life (20 years or less) of a pond. Because no large changes in physical properties were observed, we expect that changes in the physical properties of HDPE will be minor at mill tailings ponds with acidic leachate. Although testing is still underway, the PVC geomembrane has undergone some chemical reactions. Elongation declined as exposure temperatures increased, while other physical properties remained constant. The amount of aging simulated will be estimated when chemical analyses on PVC samples are completed. 11 references, 3 figures, 4 tables

  13. DNA isolation from rat tail or ear

    NARCIS (Netherlands)

    Cuppen, E.

    2010-01-01

    This protocol describes a rapid procedure for isolating DNA from rat tail or ear punches. The simplest version of the protocol can be scaled for use in 96-well (deep-well) plates. The quality of the DNA is sufficient for any polymerase chain reaction (PCR)-based genotyping approach.

  14. Mechanisms of tail resorption during anuran metamorphosis.

    Science.gov (United States)

    Nakai, Yuya; Nakajima, Keisuke; Yaoita, Yoshio

    2017-09-26

    Amphibian metamorphosis has historically attracted a good deal of scientific attention owing to its dramatic nature and easy observability. However, the genetic mechanisms of amphibian metamorphosis have not been thoroughly examined using modern techniques such as gene cloning, DNA sequencing, polymerase chain reaction or genomic editing. Here, we review the current state of knowledge regarding molecular mechanisms underlying tadpole tail resorption.

  15. Pulse pile-up. II: Tailed pulses

    International Nuclear Information System (INIS)

    Wilkinson, D.H.

    1990-07-01

    The considerations of the preceding paper are extended to the case of pulses having infinite (exponential) tails. Exact solutions are presented for pure exponential pulses all of the same height; ruin theory is applied for pulses of more realistic form. (Author) (2 refs., 9 figs.)

  16. Long term population dose due to radon (Rn-222) released from uranium mill tailings

    International Nuclear Information System (INIS)

    Chambers, D.B.; Lower, L.M.; Stager, R.H.

    2001-01-01

    The results of a study undertaken by the European Commission on the external costs (environmental and social) of various energy production systems is likely to be influential in determining how the European Union will develop its energy supply systems. The estimated costs for nuclear power from the study will be based on the findings of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), with the costs being dominated by the estimated long term (10,000 y) population doses due to radon (Rn-222) released from mill tailings. UNSCEAR developed a central estimate of 150 person-Sv per GW y and a range of 1 to 1,000 person-Sv per GW y. However, the generic data available to and being used by UNSCEAR are dated and are not appropriate for the current and planned future conditions in the uranium production industry, with the result that the estimated external costs of nuclear power (specifically, the doses due to radon emitted from mill tailings) are overestimated. The Uranium Institute sponsored a study to estimate long term population doses based on the most recent 1993 UNSCEAR methodology, but using data that would be more appropriate to the current major uranium production facilities. Site-specific information obtained from the owners/operators and the Uranium Institute included: present and proposed tailings management plans; tailings volumes and areas; ore grades and reserves; measurements and estimates of radon emission rates; and population densities. Tailings at closed facilities that no longer contribute to uranium production were not evaluated since it was assumed that these radon sources need not be considered in evaluating the external costs of current and future nuclear power production. Based on the same approach as UNSCEAR, but using a more sophisticated air dispersion model, and more site-specific data relative to existing sites and proposed tailings management practices, radon emission rates and population densities (that

  17. The production and handling of dry uranium and other tailings

    International Nuclear Information System (INIS)

    Robertson, A.M.; van Zyl, D.; Fisher, J.W.

    1982-01-01

    This paper describes equipment for producing dry tailings and proposes a simple test procedure for evaluating the effectiveness with which the resulting sloppy products can be handled in the field. Examples are given of the application of ''dry'' tailings disposal for uranium tailings and for other tailings products in the USA and other countries. The ''sloppy'' nature of ''dry'' tailings often make them difficult to handle in bulk. Methods for assessing handling, transport and stability problems associated with the tailings are discussed. Tailings are considered to be ''dry'' if they have been de-watered sufficiently that they can stand in a substantial pile and can be handled by conventional earth moving equipment without liquefying. It is determined that tailings with moisture contents below or a little above the liquid limit can generally be handled by conventional earth moving equipment. Trafficability and stability require moisture contents appreciably below the liquid limit

  18. 14 CFR 23.745 - Nose/tail wheel steering.

    Science.gov (United States)

    2010-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Landing Gear § 23.745 Nose/tail wheel steering. (a) If nose/tail wheel steering is installed, it must be... gear. Floats and Hulls ...

  19. Microorganisms in oil sands tailings ponds influence the properties and behaviour of mature fine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Bressler, D.; Cardenas, M.; Fedorak, P.M.; Guigard, S.; Gupta, R.; Siddique, T.; Foght, J. [Alberta Univ., Edmonton, AB (Canada)

    2010-07-01

    Large numbers of microorganisms are present in the mature fine tailings produced during oil sands operations. Many different types of microbes grow in communities that compete and cooperate. Most of the microorganisms are anaerobic, and include sulfate-reducing bacteria, nitrate-reducing bacteria, iron-reducing bacteria, fermenters, and methanogens. The microbes produce approximately 40 million litres of greenhouse gases (GHGs), methane (CH{sub 4}) and carbon dioxide (CO{sub 2}). All tailings ponds are microbiologically different. The gases are produced by microbial waste products and have been observed to degrade fugitive naphtha in fresh tailings at a Syncrude oil sands facility. At a Shell-Albian Sands facility, the microbes degraded into trisodium citrate. The microbes can aid in the settling of tailings. Agricultural byproducts have been added to tailings in order to demonstrate methane production. However, flow through systems are required to accelerate the biodensification of tailings ponds, and further studies are needed to ensure that the quality of recovered water is maintained for re-use. Various microbe degradation processes and models were presented. tabs., figs.

  20. Strategic Management Plan for Columbian Sharp-Tailed Grouse 2002

    OpenAIRE

    State of Utah, Department of Natural Resoures, Division of Wildlife Resources

    2002-01-01

    The Columbian Sharp-tailed Grouse (Tympanuchus phasianellus columbianus) is one of seven subspecies of Sharp-tailed Grouse. Historically, Columbian Sharp-tailed Grouse occurred within sagebrush-native bunch grass habitat throughout the intermountain region, extending from British Columbia, Washington, Idaho and Montana south through portions of Oregon, California, Nevada, Utah, Wyoming, Colorado and New Mexico. Sharp-tailed Grouse populations range-wide began declining during 1880-1920 (Bart ...

  1. Tail-assisted pitch control in lizards, robots and dinosaurs.

    Science.gov (United States)

    Libby, Thomas; Moore, Talia Y; Chang-Siu, Evan; Li, Deborah; Cohen, Daniel J; Jusufi, Ardian; Full, Robert J

    2012-01-04

    In 1969, a palaeontologist proposed that theropod dinosaurs used their tails as dynamic stabilizers during rapid or irregular movements, contributing to their depiction as active and agile predators. Since then the inertia of swinging appendages has been implicated in stabilizing human walking, aiding acrobatic manoeuvres by primates and rodents, and enabling cats to balance on branches. Recent studies on geckos suggest that active tail stabilization occurs during climbing, righting and gliding. By contrast, studies on the effect of lizard tail loss show evidence of a decrease, an increase or no change in performance. Application of a control-theoretic framework could advance our general understanding of inertial appendage use in locomotion. Here we report that lizards control the swing of their tails in a measured manner to redirect angular momentum from their bodies to their tails, stabilizing body attitude in the sagittal plane. We video-recorded Red-Headed Agama lizards (Agama agama) leaping towards a vertical surface by first vaulting onto an obstacle with variable traction to induce a range of perturbations in body angular momentum. To examine a known controlled tail response, we built a lizard-sized robot with an active tail that used sensory feedback to stabilize pitch as it drove off a ramp. Our dynamics model revealed that a body swinging its tail experienced less rotation than a body with a rigid tail, a passively compliant tail or no tail. To compare a range of tails, we calculated tail effectiveness as the amount of tailless body rotation a tail could stabilize. A model Velociraptor mongoliensis supported the initial tail stabilization hypothesis, showing as it did a greater tail effectiveness than the Agama lizards. Leaping lizards show that inertial control of body attitude can advance our understanding of appendage evolution and provide biological inspiration for the next generation of manoeuvrable search-and-rescue robots.

  2. 14 CFR 25.497 - Tail-wheel yawing.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tail-wheel yawing. 25.497 Section 25.497... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.497 Tail-wheel yawing. (a) A vertical ground reaction equal to the static load on the tail wheel, in combination with a side component of equal...

  3. Leachability of metals from gold tailings by rainwater: an ...

    African Journals Online (AJOL)

    Mine leachates from gold tailings impoundments usually contain elevated concentrations of metals and sulphates that impact negatively on water quality. This study was aimed at assessing the leachability of such metals from tailings by rainwater. Oxidised and unoxidised tailings were leached experimentally and through ...

  4. Leachability of metals from gold tailings by rainwater: an ...

    African Journals Online (AJOL)

    2016-01-01

    Jan 1, 2016 ... ABSTRACT. Mine leachates from gold tailings impoundments usually contain elevated concentrations of metals and sulphates that impact negatively on water quality. This study was aimed at assessing the leachability of such metals from tailings by rainwater. Oxidised and unoxidised tailings were leached ...

  5. A new procedure for deep sea mining tailings disposal

    NARCIS (Netherlands)

    Ma, W.; Schott, D.L.; Lodewijks, G.

    2017-01-01

    Deep sea mining tailings disposal is a new environmental challenge related to water pollution, mineral crust waste handling, and ocean biology. The objective of this paper is to propose a new tailings disposal procedure for the deep sea mining industry. Through comparisons of the tailings disposal

  6. Costs associated with tail autotomy in an ambush foraging lizard ...

    African Journals Online (AJOL)

    We induced tail autotomy in free ranging male Cordylus m. melanotus and measured potential shifts in behaviour (movements, foraging behaviour, time exposed and average distance to a potential refuge), and responses to an approaching human compared to marked individuals with complete tails. Tailed and tailless ...

  7. Spectrum of human tails: A report of six cases

    Directory of Open Access Journals (Sweden)

    Biswanath Mukhopadhyay

    2012-01-01

    Full Text Available Human tail is a curiosity, a cosmetic stigma and presents as an appendage in the lumbosacral region. Six patients of tail in the lumbosacral region are presented here to discuss the spectrum of presentation of human tails. The embryology, pathology and treatment of this entity are discussed along with a brief review of the literature.

  8. Electro-remediation of copper mine tailings. Comparing copper removal efficiencies for two tailings of different age

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Lamas, Victor; Gutierrez, Claudia

    2013-01-01

    This work compares and evaluates the copper removal efficiency when applying electric fields to two mine tailings originating from the same mine but of different age. Eight experiments were carried out - four on tailings deposited more than 20 years ago (old tailings) and four on tailings deposited...... less than 2 years ago (new tailings). Parameters analyzed were the applied voltage drop, acid concentration during pretreatment, and the use of either passive or ion exchange membranes in the experimental setup. The comparison of the results confirms that there are differences in the electroremediation...... between the two tailings, even if the pH is similar and a mineralogical analysis showed similarities between the samples with respect to composition. It was found that an electroremediation is more favorable on the old tailings. The results showed that the best experimental conditions for both tailings...

  9. Browsing patterns of white-tailed deer following increased timber harvest and a decline in population density

    Science.gov (United States)

    Shawn M. Crimmins; John W. Edwards; W. Mark Ford; Patrick D. Keyser; James M. Crum

    2010-01-01

    We examined browsing patterns of white-tailed deer (Odocoileus virginianus) on a site in the central Appalachians that experienced a substantial (>50%) reduction in deer population density and an increase in the amount of timber harvest since 2001. We sampled woody browse in and immediately adjacent to 12 clearcuts ranging in age from 0-5 years...

  10. Tail biting behaviour and tail damage in pigs and the relationship with general behaviour: Predicting the inevitable?

    NARCIS (Netherlands)

    Ursinus, W.W.; Reenen, van C.G.; Kemp, B.; Bolhuis, J.E.

    2014-01-01

    Tail biting behaviour in pigs is a common problem in conventional housing systems. Our study examined the consistency over time in tail biting and tail damage and it explored the predictive value of general behaviours observed in individual pigs and in pens as a whole. Pigs (n = 480), reared in

  11. Monte Carlo-Based Tail Exponent Estimator

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Vácha, Lukáš

    2010-01-01

    Roč. 2010, č. 6 (2010), s. 1-26 R&D Projects: GA ČR GA402/09/0965; GA ČR GD402/09/H045; GA ČR GP402/08/P207 Institutional research plan: CEZ:AV0Z10750506 Keywords : Hill estimator * α-stable distributions * tail exponent estimation Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2010/E/barunik-0342493.pdf

  12. T-tail flutter analysis using Edge

    CSIR Research Space (South Africa)

    Van Zyl, Lourens H

    2011-11-01

    Full Text Available shape components). The solution of the structural equation of motion was modified accordingly. This approach is obviously very costly in terms of memory, since a modal mesh deformation is associated with each quadratic mode shape component... a permanent disclaimer on our CFD computer room door that reads: ?The purpose of simulation is insight, not numbers.? Oscar Buneman 1986 A more cynical person, e.g. the first author, might have replaced ?insight? with ?colours?. T-tail flutter...

  13. Tail Rotor Airfoils Stabilize Helicopters, Reduce Noise

    Science.gov (United States)

    2010-01-01

    Founded by former Ames Research Center engineer Jim Van Horn, Van Horn Aviation of Tempe, Arizona, built upon a Langley Research Center airfoil design to create a high performance aftermarket tail rotor for the popular Bell 206 helicopter. The highly durable rotor has a lifetime twice that of the original equipment manufacturer blade, reduces noise by 40 percent, and displays enhanced performance at high altitudes. These improvements benefit helicopter performance for law enforcement, military training, wildfire and pipeline patrols, and emergency medical services.

  14. Tailings management for the twenty-first century

    International Nuclear Information System (INIS)

    Frost, S.E.

    1996-01-01

    The evolution of tailings management at Saskatchewan uranium mines is traced from the fifties to the nineties. Some of the problems with past systems are discussed. The new tailings systems now being proposed for the new operations currently undergoing environmental assessment in Saskatchewan are examined in detail. These new systems represent a change in tailings management philosophy, from keeping tailings high and dry on the surface, to placement of tailings in a low-energy regime within the water table. There they are removed from the active surface environment, avoiding future erosion problems, with a reduced likelihood of suffering intrusion from future human or animal activities. (author). 16 refs., 5 figs

  15. Tailings dams from the perspective of conventional dam engineering

    International Nuclear Information System (INIS)

    Szymanski, M.B.

    1999-01-01

    A guideline intended for conventional dams such as hydroelectric, water supply, flood control, or irrigation is used sometimes for evaluating the safety of a tailings dam. Differences between tailings dams and conventional dams are often substantial and, as such, should not be overlooked when applying the techniques or safety requirements of conventional dam engineering to tailings dams. Having a dam safety evaluation program developed specifically for tailings dams is essential, if only to reduce the chance of potential errors or omissions that might occur when relying on conventional dam engineering practice. This is not to deny the merits of using the Canadian Dam Safety Association Guidelines (CDSA) and similar conventional dam guidelines for evaluating the safety of tailings dams. Rather it is intended as a warning, and as a rationale underlying basic requirement of tailings dam emgineering: specific experience in tailings dams is essential when applying conventional dam engineering practice. A discussion is included that focuses on the more remarkable tailings dam safety practics. It is not addressed to a technical publications intended for such dams, or significantly different so that the use of conventional dam engineering practice would not be appropriate. The CDSA Guidelines were recently revised to include tailings dams. But incorporating tailings dams into the 1999 revision of the CDSA Guidelines is a first step only - further revision is necessary with respect to tailings dams. 11 refs., 2 tabs

  16. Cement mixtures containing copper tailings as an additive: durability properties

    Directory of Open Access Journals (Sweden)

    Obinna Onuaguluchi

    2012-12-01

    Full Text Available The effects of copper tailings as an additive, on some durability properties of cement mixtures were investigated. In each mixture, copper tailings addition levels by mass were 0%, 5% and 10%. Compared to the control samples, copper tailings blended pastes showed superior performance against autoclave expansion while insignificant decreases in sulfate resistance of mortars were observed. Copper tailings increased the water absorption and total permeable voids of concretes slightly. However, the compressive and flexural strengths of blended concretes were higher than those of the control samples. Similarly, improved resistance to acid attack and chloride penetration as the copper tailings content of concretes increased were also observed. Results further showed that the ASTM C 1202 rapid chloride permeability test may not be a valid indicator of chloride migration in mixtures containing conductive copper tailings. These results suggest that copper tailings can potentially enhance the durability properties of cement based materials.

  17. Fat-tailed risk about climate change and climate policy

    International Nuclear Information System (INIS)

    Hwang, In Chang; Tol, Richard S.J.; Hofkes, Marjan W.

    2016-01-01

    This paper investigates the role of emissions control in welfare maximization under fat-tailed risk about climate change. We provide a classification of fat tails and discuss the effect of fat-tailed risk on climate policy. One of the main findings is that emissions control may prevent the “strong” tail-effect from arising, at least under some conditions such as bounded temperature increases, low risk aversion, low damage costs, and bounded utility function. More specifically, the fat-tailed risk with respect to a climate parameter does not necessarily lead to an unbounded carbon tax. In this case, the basic principle of cost-benefit analysis maintains its applicability. - Highlights: • A fat tail is classified and the tail effect on climate policy is discussed. • The optimal carbon tax is not necessarily unbounded. • The basic principle of cost-benefit analysis maintains its applicability. • This is a numerical confirmation of the recent theoretical research.

  18. A Note on Upper Tail Behavior of Liouville Copulas

    Directory of Open Access Journals (Sweden)

    Lei Hua

    2016-11-01

    Full Text Available The family of Liouville copulas is defined as the survival copulas of multivariate Liouville distributions, and it covers the Archimedean copulas constructed by Williamson’s d-transform. Liouville copulas provide a very wide range of dependence ranging from positive to negative dependence in the upper tails, and they can be useful in modeling tail risks. In this article, we study the upper tail behavior of Liouville copulas through their upper tail orders. Tail orders of a more general scale mixture model that covers Liouville distributions is first derived, and then tail order functions and tail order density functions of Liouville copulas are derived. Concrete examples are given after the main results.

  19. Asphalt emulsion sealing of uranium mill tailings. 1979 annual report

    International Nuclear Information System (INIS)

    Hartley, J.N.; Koehmstedt, P.L.; Esterl, D.J.; Freeman, H.D.

    1980-06-01

    Uranium mill tailings are a source of low-level radiation and radioactive materials that may be released into the environment. Stabilization or disposal of these tailings in a safe and environmentally sound way is necessary to minimize radon exhalation and other radioactive releases. One of the most promising concepts for stabilizing uranium tailings is being investigated at the Pacific Northwest Laboratory: the use of asphalt emulsion to contain radon and other potentially hazardous materials in uranium tailings. Results of these studies indicate that radon flux from uranium tailings can be reduced by greater than 99% by covering the tailings with an asphalt emulsion that is poured on or sprayed on (3.0 to 7.0 mm thick), or mixed with some of the tailings and compacted to form an admixture seal (2.5 to 15.2 cm) containing 18 wt % residual asphalt

  20. Central limit theorems under special relativity.

    Science.gov (United States)

    McKeague, Ian W

    2015-04-01

    Several relativistic extensions of the Maxwell-Boltzmann distribution have been proposed, but they do not explain observed lognormal tail-behavior in the flux distribution of various astrophysical sources. Motivated by this question, extensions of classical central limit theorems are developed under the conditions of special relativity. The results are related to CLTs on locally compact Lie groups developed by Wehn, Stroock and Varadhan, but in this special case the asymptotic distribution has an explicit form that is readily seen to exhibit lognormal tail behavior.

  1. Oil sands tailings technology : understanding the impact to reclamation

    Energy Technology Data Exchange (ETDEWEB)

    Mamer, M. [Suncor Energy Inc., Fort McMurray, AB (Canada)

    2010-07-01

    This paper discussed tailings management techniques at oil sands mines and their effects on reclamation schedules and outcomes. The layer of mature fine tailings (MFT) that forms in tailings ponds does not settle within a reasonable time frame, requiring more and larger tailings ponds for storing MFT. Consolidated tailings (CT) technology was developed to accelerate the consolidation of MFT, although the process nonetheless takes decades. CT is produced from mixing tailings sand, gypsum, and MFT to create a mixture that will consolidate more quickly and release water. However, CT production is tied to the extraction process, making it applicable only when the plant is operational, and a precise recipe and accurate injection are required for CT to work. In tailings reduction operations (TRO), a new approach to tailings management, MFT is mixed with a polymer flocculant, deposited in thin layers, and allowed to dry. TRO has a significant advantage over CT in that the latter takes up to 30 years to consolidate to a trafficable surface compared to weeks for TRO. TRO allows MFT to be consumed more quickly than it is produced, reducing need to build more tailings ponds, operates independent of plant operations, accelerates the reclamation time frame, and offers enhanced flexibility in final tailings placement sites. TRO also creates a dry landscape, to which well established reclamation techniques can be applied. Dried MFT is a new material type, and research is exploring optimum reclamation techniques. 2 figs.

  2. Dwarf Galaxies Swimming in Tidal Tails

    Science.gov (United States)

    2005-01-01

    This false-color infrared image from NASA's Spitzer Space Telescope shows little 'dwarf galaxies' forming in the 'tails' of two larger galaxies that are colliding together. The big galaxies are at the center of the picture, while the dwarfs can be seen as red dots in the red streamers, or tidal tails. The two blue dots above the big galaxies are stars in the foreground. Galaxy mergers are common occurrences in the universe; for example, our own Milky Way galaxy will eventually smash into the nearby Andromeda galaxy. When two galaxies meet, they tend to rip each other apart, leaving a trail, called a tidal tail, of gas and dust in their wake. It is out of this galactic debris that new dwarf galaxies are born. The new Spitzer picture demonstrates that these particular dwarfs are actively forming stars. The red color indicates the presence of dust produced in star-forming regions, including organic molecules called polycyclic aromatic hydrocarbons. These carbon-containing molecules are also found on Earth, in car exhaust and on burnt toast, among other places. Here, the molecules are being heated up by the young stars, and, as a result, shine in infrared light. This image was taken by the infrared array camera on Spitzer. It is a 4-color composite of infrared light, showing emissions from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange), and 8.0 microns (red). Starlight has been subtracted from the orange and red channels in order to enhance the dust features.

  3. Contemporary Pollution Due Old Uranium Tails

    International Nuclear Information System (INIS)

    Hadjamberdiev, I.

    2007-01-01

    The areas of our study are uranium mining areas (with tails and dumps) Min-Kush, Kadji-Sai, Mailuu-Suu. These areas situated in different parts of Tien-Shan region. We study the content (and correlations among): level of uranium in environment, immune function and level, level in human teeth. It has been found: content of uranium in river water under tails about 2,0x10-5 gm/litter, and high level in drinking water too 2,0-4,0. Drying grass and flowers uranium content was 0,04-0,51x10-5 gm/gm, most high content were in Tacniatherum crinitum and Atgilops triuncialis. Lams tissues contain 0,005-2,44 mg/g in Min-Kush, 0,03-0,107, in Mailuu-Suu, and 0,001-0,048 mg/g in Kadji-Sai. Human teeth uranium content (Mailuu-Suu): in milk-teeth 0,481x10-6 gm/gm, in former miners 0,7684x10-6 gm/gm. Inhabitants of the area, which not working in uranium industry have 0,6876x10-6 gm/gm. There was low level of immune function (lymphocytes, IgI globulin, etc) in all three regions (in child, in adults, in uranium-mining worked people). There is no doubt of the positive correlations of uranium pollution of water (by underground infiltration from tails) on one hand and, on the other hand - a) grass, b) lambs body, c) human teeth, d) human immune function. Levels of uranium in teeth strictly depend on time of mining contact. (author)

  4. Monte Carlo-based tail exponent estimator

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Vácha, Lukáš

    2010-01-01

    Roč. 389, č. 21 (2010), s. 4863-4874 ISSN 0378-4371 R&D Projects: GA ČR GA402/09/0965; GA ČR GD402/09/H045; GA ČR GP402/08/P207 Institutional research plan: CEZ:AV0Z10750506 Keywords : Hill estimator * α-stable distributions * Tail exponent estimation Subject RIV: AH - Economics Impact factor: 1.521, year: 2010 http://library.utia.cas.cz/separaty/2010/E/barunik-0346486.pdf

  5. Framework for T-tail flutter analysis

    CSIR Research Space (South Africa)

    Van Zyl, Lourens H

    2011-06-01

    Full Text Available Calculating unsteady generalized aerodynamic forces for a given Mach number, reduced frequency, steady load distribution and deflected shape The p-k flutter solver was modified to Call the DLM routine once to read the geometry At each speed increment... for that condition can be calculated. The present paper presents a procedure for performing a flutter analysis of a T-tailed aircraft in a given loading condition over a range of speeds. The first step at each speed is the aeroelastic trim analysis. Flutter...

  6. Optimization in the decommissioning of uranium tailings

    International Nuclear Information System (INIS)

    1987-06-01

    This report examines in detail the problem of choosing the optimal decommissioning approach for uranium and mill tailings sites. Various decision methods are discussed and evaluated, and their application in similar decision problems are summarized. This report includes, by means of a demonstration, a step by step guide of how a number of selected techniques can be applied to a decommissioning problem. The strengths and weaknesses of various methods are highlighted. A decision system approach is recommended for its flexibility and incorporation of many of the strengths found in other decision methods

  7. Biogeochemistry of metalliferous mine tailings during phytostabilizatio

    Science.gov (United States)

    Chorover, J.; Root, R. A.; Hammond, C.; Wang, Y.; Maier, R. M.

    2015-12-01

    In the semi-arid southwest US, legacy mine tailings and the associated metal(loid) contaminants, are prone to wind dispersion and water erosion. Without remediation, tailings can remain barren for decades to centuries, providing a point source of toxic contamination. Successful mitigation of toxins (As, Pb) from fugitive dust is often limited to confinement and stabilization. Capping mine tailings with soil or gravel is an accepted, although expensive, strategy to reduce erosion. Revegetation via assisted direct planting (also known as phytostabilization) has the potential to be a cost-effective and self-sustaining alternative "green-technology" to expensive capping. The impact of phytostabilization, and requisite added organic carbon and irrigation on mechanisms of contaminant mobility is being investigated with concurrent highly-instrumented greenhouse mesocosms and in situ field studies using advanced microbiological tools and synchrotron x-ray based molecular probes. Composted treatments initially neutralized the near surface acid tailings (~2 to ~6.5). However, after 9 mo the mesocosms showed a gradual and eventual decrease back to pH 2. The exception was the root zone of Atriplex lentiformis, which buffered the acidic conditions for 12 months. Rhizosphere microbiota experienced a 5-log increase in the compost-amended compared to control greenhouse mesocosms. Weathering of the primary sulfidic mineral assemblage, indicated by the iron and sulfur speciation, was shown to control the mobility, speciation and bioavailability of both As and Pb via sequestration in (meta)stable neoformed jarosite phases as plumbojarosite and As(V) substituted for sulfate in hydronium jarosite, with important implications for human and environmental health risk management. We conclude that the disequilibrium imposed by phytostabilization results in an increase of heterotrophic biomass that is concurrent with a time series of geochemical transformations, which controls the species

  8. Winter habitat associations of diurnal raptors in Californias Central Valley

    Science.gov (United States)

    Pandolrno, E.R.; Herzog, M.P.; Hooper, S.L.; Smith, Z.

    2011-01-01

    The wintering raptors of California's Central Valley are abundant and diverse. Despite this, little information exists on the habitats used by these birds in winter. We recorded diurnal raptors along 19 roadside survey routes throughout the Central Valley for three consecutive winters between 2007 and 2010. We obtained data sufficient to determine significant positive and negative habitat associations for the White-tailed Kite (Elanus leucurus), Bald Eagle {Haliaeetus leucocephalus), Northern Harrier (Circus cyaneus), Red-tailed Hawk (Buteo jamaicensis), Ferruginous Hawk (Buteo regalis), Rough-legged Hawk (Buteo lagopus), American Kestrel (Falco sparverius), and Prairie Falcon (Falco mexicanus). The Prairie Falcon and Ferruginous and Rough-legged hawks showed expected strong positive associations with grasslands. The Bald Eagle and Northern Harrier were positively associated not only with wetlands but also with rice. The strongest positive association for the White-tailed Kite was with wetlands. The Red-tailed Hawk was positively associated with a variety of habitat types but most strongly with wetlands and rice. The American Kestrel, Northern Harrier, and White-tailed Kite were positively associated with alfalfa. Nearly all species were negatively associated with urbanized landscapes, orchards, and other intensive forms of agriculture. The White-tailed Kite, Northern Harrier, Redtailed Hawk, Ferruginous Hawk, and American Kestrel showed significant negative associations with oak savanna. Given the rapid conversion of the Central Valley to urban and intensive agricultural uses over the past few decades, these results have important implications for conservation of these wintering raptors in this region.

  9. Pilot projects for the remediation of Sillamaee uranium tailings in Estonia

    International Nuclear Information System (INIS)

    Kaasik, T.; Siinmaa, A.

    2001-01-01

    First Estonian uranium, produced in a pilot plant at Narva, was presented to Soviet military administration in 1945 and just a year later - 1946 - installation of an uranium production plant was started at Sillamaee, Estonia. Estonian local ore - alum shale - containing only 0,026% of uranium was used for uranium production for nearly five years, after the plant was launched in 1948. The uranium mine, having been activated from 1947 to 1952, was left in status of 'active conservation' for 17 years, until finally closed in 1969. Potential threats of this hidden legacy have never been revealed. After close-down of local uranium mine, more than 4 million tons of ore, imported mostly from Central and East European countries: Czechoslovakia, Hungary and Eastern Germany were processed at Sillamaee. These activities have left a large tailings impoundment with the total volume of ca. 8 million cubic meters in the immediate vicinity of the Baltic Sea. Today the plant is privatized, converted to civil purposes and provides together its power generating facilities ca. 1200 jobs in the socially sensitive area of North-East Estonia, while environmental hazards of the history, however, remain: - Continuous seepage of tailing waters into the sea contributes and would contribute over long term to the pollution of the Baltic Sea; - stability of the tailings dam seaside under present conditions can not be guaranteed thus risking a sudden release of partly liquid tailings due to potential dam failure; - uncovered surface of the tailings presents a health hazard due to dusting and radon release and hinders the revitalization of the area. The conceptual design of the Estonia's largest environmental remediation project, done by Wismut, is now complete and first implementation steps are underway. The project for mine area restoration is in initiation phase; it shall reveal the current and potential environmental hazards of the facility and create the concept for necessary rehabilitation

  10. Soft tissue preservation in a fossil marine lizard with a bilobed tail fin.

    Science.gov (United States)

    Lindgren, Johan; Kaddumi, Hani F; Polcyn, Michael J

    2013-01-01

    Mosasaurs are secondarily aquatic squamates that became the dominant marine reptiles in the Late Cretaceous about 98-66 million years ago. Although early members of the group possessed body shapes similar to extant monitor lizards, derived forms have traditionally been portrayed as long, sleek animals with broadened, yet ultimately tapering tails. Here we report an extraordinary mosasaur fossil from the Maastrichtian of Harrana in central Jordan, which preserves soft tissues, including high fidelity outlines of a caudal fluke and flippers. This specimen provides the first indisputable evidence that derived mosasaurs were propelled by hypocercal tail fins, a hypothesis that was previously based on comparative skeletal anatomy alone. Ecomorphological comparisons suggest that derived mosasaurs were similar to pelagic sharks in terms of swimming performance, a finding that significantly expands our understanding of the level of aquatic adaptation achieved by these seagoing lizards.

  11. Characterization of ten microsatellite loci in the Broad-tailed hummingbird (Selasphorus platycercus)

    Science.gov (United States)

    Oyler-McCance, Sara J.; Fike, Jennifer A.; Talley-Farnham, Tiffany; Engelman, Tena; Engelman, Fred

    2011-01-01

    The Broad-tailed Hummingbird (Selaphorus platycercus) breeds at higher elevations in the central and southern Rockies, eastern California, and Mexico and has been studied for 8 years in Rocky Mountain National Park, Colorado. Questions regarding the relatedness of Broad-tailed Hummingbirds banded together and then recaptured in close time proximity in later years led us to isolate and develop primers for 10 polymorphic microsatellite loci. In a screen of 25 individuals from a population in Rocky Mountain National Park, the 10 loci were found to have levels of variability ranging from two to 16 alleles. No loci were found to depart from linkage disequilibrium, although two loci revealed significant departures from Hardy–Weinberg equilibrium. These 10 microsatellite loci will be applicable for population genetic analyses, investigation of mating systems and relatedness, and may help gain insight into the migration timing and routes for this species.

  12. On the importance of tail ratios for psychological science.

    Science.gov (United States)

    Voracek, Martin; Mohr, Elisabeth; Hagmann, Michael

    2013-06-01

    Even small group-mean differences (whether combined with variance differences or not) or variance differences alone (absent mean differences) can generate marked and sometimes surprising imbalances in the representation of the respective groups compared in the distributional tail regions. Such imbalances in group representation, quantified as tail ratios, have general importance in the context of any threshold, susceptibility, diathesis-stress, selection, or similar models (including the study of sex differences), as widely conceptualized and applied in the psychological, social, medical, and biological sciences. However, commonly used effect-size measures, such as Cohen's d, largely exploit data information around the center of distributions, rather than from the tails, thereby missing potentially important patterns found in the tail regions. This account reviews the background and history of tail ratios, emphasizes their importance for psychological research, proposes a consensus approach for defining and interpreting them, introduces a tail-ratio calculator, and outlines future research agenda.

  13. Utilization of mine tailings as partial cement replacement

    DEFF Research Database (Denmark)

    Sigvardsen, Nina Marie; Nielsen, M.R.; Ottosen, Lisbeth M.

    2017-01-01

    Depositing mine tailings entail major economic costs and negative environmental impacts. Thus finding an alternative to depositing is of interest. This study focused on the use of mine tailings as partial cement replacement, thereby preventing depositing the mine tailings. At the same time......, such use would reduce the CO2 emission related to the production of cement. Mine tailings from two different mines Zinkgruvan (Sweden) and Nalunaq (Greenland) were both tested as 5 and 10 % cement replacement. All mortar specimens with mine tailings had lower compressive strength compared to a reference...... compared to a specimen containing a 10 % replacement of cement with coal fly ash, commonly used in Denmark. The compressive strength of specimens containing mine tailings exceeded the compressive strength of the specimen containing coal fly ash, indicating further the amorphous content of volcanic decent...

  14. The problem of abandoned uranium tailings in northern Saskatchewan

    International Nuclear Information System (INIS)

    Swanson, S.; Abouguendia, Z.

    1981-11-01

    Two Saskatchewan tailings sites, Lorado and Gunnar, covering approximately 89 ha., were abandoned in the early 1960s leaving untreated tailings in lakes and depressions. This report reviews the literature on environmental conditions in abandoned uranium tailings and available managmenet and mitigation options, and identifies research requirements essential for proper treatment of these two sites. The recommended management plan includes isolation of the exposed tailings area from surface waters, stabilization of the exposed tailings surfaces, diversion of runoff around tailings, treatment of overflow water before release, and implementation of an environmental monitoring program. Revegetation appears to be a promising stabilization measure, but research is needed into propagation methods of appropriate native species. Studies of the existing geological and hydrological conditions at both sites, detailed characterization of the wastes, field testing of different surface treatment methods, and nutrient cycling investigations are also needed

  15. Sulfur biogeochemistry of oil sands composite tailings

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Lesley; Stephenson, Kate [Earth Sciences, McMaster University (Canada)], email: warrenl@mcmaster.ca; Penner, Tara [Syncrude Environmental Research (Canada)

    2011-07-01

    This paper discusses the sulfur biogeochemistry of oil sands composite tailings (CT). The Government of Alberta is accelerating reclamation activities on composite tailings. As a CT pilot reclamation operation, Syncrude is currently constructing the first freshwater fen. Minor unpredicted incidents with H2S gas released from the dewatering process associated with these reclamations have been reported. The objective of this study is to ascertain the connection between microbial activity and H2S generation within CT and to assess the sulfur biogeochemistry of untreated and treated (fen) CT over seasonal and annual timescales. The microbial geochemical interactions taking place are shown using a flow chart. CT is composed of gypsum, sand, clay and organics like naphthenic acids and bitumen. Sulfur and Fe cycling in mining systems and their microbial activities are presented. The chemistry and the processes involved within CT are also given along with the results. It can be said that the diverse Fe and S metabolizing microorganisms confirm the ecology involved in H2S dynamics.

  16. Submarine Tailings Disposal (STD—A Review

    Directory of Open Access Journals (Sweden)

    Bernhard Dold

    2014-07-01

    Full Text Available The mining industry is a fundamental industry involved in the development of modern society, but is also the world’s largest waste producer. This role will be enhanced in the future, because ore grades are generally decreasing, thus leading to increases in the waste/metal production ratio. Mine wastes deposited on-land in so-called tailings dams, impoundments or waste-dumps have several associated environmental issues that need to be addressed (e.g., acid mine drainage formation due to sulphide oxidation, geotechnical stability, among others, and social concerns due to land use during mining. The mining industry recognizes these concerns and is searching for waste management alternatives for the future. One option used in the past was the marine shore or shallow submarine deposition of this waste material in some parts of the world. After the occurrence of some severe environmental pollution, today the deposition in the deep sea (under constant reducing conditions is seen as a new, more secure option, due to the general thought that sulphide minerals are geochemically stable under the reduced conditions prevailing in the deep marine environment. This review highlights the mineralogical and geochemical issues (e.g., solubility of sulphides in seawater; reductive dissolution of oxide minerals under reducing conditions, which have to be considered when evaluating whether submarine tailings disposal is a suitable alternative for mine waste.

  17. Environmental impact analysis of mine tailing reservoir

    Science.gov (United States)

    Gong, J. Z.

    2016-08-01

    Under certain conditions landscape topography which utilizes mine tailing reservoir construction using is likely to increase lateral recharge source regions, resulting in dramatic changes to the local hydrological dynamic field and recharge of downstream areas initiated by runoff, excretion state, elevated groundwater depth, shallow groundwater, rainfall direct communication, and thinning of the vadose zone. Corrosive leaching of topsoil over many years of exposure to chemical fertilizers and pesticides may result in their dissolution into the groundwater system, which may lead to excessive amounts of many harmful chemicals, therby affecting the physical and mental health of human residents and increase environmental vulnerability and risk associated with the water and soil. According to field survey data from Yujiakan, Qian'an City, and Hebei provinces, this paper analyzes the hydrogeological environmental mechanisms of areas adjacent to mine tailing reservoirs and establishes a conceptual model of the local groundwater system and the concentration-response function between NO3 - content in groundwater and the incidence of cancer in local residents.

  18. Approximate MAP Decoding on Tail-Biting Trellises

    OpenAIRE

    Madhu, A. S.; Shankar, Priti

    2005-01-01

    We propose two approximate algorithms for MAP decoding on tail-biting trellises. The algorithms work on a subset of nodes of the tail-biting trellis, judiciously selected. We report the results of simulations on an AWGN channel using the approximate algorithms on tail-biting trellises for the $(24,12)$ Extended Golay Code and a rate 1/2 convolutional code with memory 6.

  19. Manual for the sampling of uranium mine tailings

    International Nuclear Information System (INIS)

    Feenstra, S.; Reades, D.W.; Cherry, J.A.; Chambers, D.B.; Case, G.G.; Ibbotson, B.G.

    1983-04-01

    The purpose of this manual is to describe the requisite sampling procedures to provide a basis for the application of uniform high-quality standards to detailed geotechnical, hydrogeological, geochemical and air quality measurements at Canadian uranium tailings disposal sites. The report describes the objective and scope of a sampling program, the preliminary data collection, and the procedures for sampling of tailings solids, surface water and seepage, tailings porewater, and wind-blown dust and radon

  20. Review of fugitive dust control for uranium mill tailings

    International Nuclear Information System (INIS)

    Li, C.T.; Elmore, M.R.; Hartley, J.N.

    1983-01-01

    An immediate concern associated with the disposal of uranium mill tailings is that wind erosion of the tailings from an impoundment area will subsequently deposit tailings on surrounding areas. Pacific Northwest Laboratory (PNL), under contract to the U.S. Nuclear Regulatory Commission, is investigating the current technology for fugitive dust control. Different methods of fugitive dust control, including chemical, physical, and vegetative, have been used or tested on mill tailings piles. This report presents the results of a literature review and discussions with manufacturers and users of available stabilization materials and techniques

  1. Estimating impact forces of tail club strikes by ankylosaurid dinosaurs.

    Directory of Open Access Journals (Sweden)

    Victoria Megan Arbour

    Full Text Available BACKGROUND: It has been assumed that the unusual tail club of ankylosaurid dinosaurs was used actively as a weapon, but the biological feasibility of this behaviour has not been examined in detail. Ankylosaurid tail clubs are composed of interlocking vertebrae, which form the handle, and large terminal osteoderms, which form the knob. METHODOLOGY/PRINCIPAL FINDINGS: Computed tomographic (CT scans of several ankylosaurid tail clubs referred to Dyoplosaurus and Euoplocephalus, combined with measurements of free caudal vertebrae, provide information used to estimate the impact force of tail clubs of various sizes. Ankylosaurid tails are modeled as a series of segments for which mass, muscle cross-sectional area, torque, and angular acceleration are calculated. Free caudal vertebrae segments had limited vertical flexibility, but the tail could have swung through approximately 100 degrees laterally. Muscle scars on the pelvis record the presence of a large M. longissimus caudae, and ossified tendons alongside the handle represent M. spinalis. CT scans showed that knob osteoderms were predominantly cancellous, which would have lowered the rotational inertia of the tail club and made it easier to wield as a weapon. CONCLUSIONS/SIGNIFICANCE: Large knobs could generate sufficient force to break bone during impacts, but average and small knobs could not. Tail swinging behaviour is feasible in ankylosaurids, but it remains unknown whether the tail was used for interspecific defense, intraspecific combat, or both.

  2. Modelling of contaminant release from a uranium mine tailings site

    International Nuclear Information System (INIS)

    Kahnt, Rene; Metschies, Thomas

    2007-01-01

    Available in abstract form only. Full text of publication follows: Uranium mining and milling continuing from the early 1960's until 1990 close to the town of Seelingstaedt in Eastern Germany resulted in 4 tailings impoundments with a total tailings volume of about 105 Mio. m 3 . Leakage from these tailings impoundments enters the underlying aquifers and is discharged into surface water streams. High concentration of salts, uranium and several heavy metals are released from the tailings. At present the tailings impoundments are reshaped and covered. For the identification of suitable remediation options predictions of the contaminant release for different remediation scenarios have to be made. A compartment model representing the tailings impoundments and the surrounding aquifers for the calculation of contaminant release and transport was set up using the software GOLDSIM. This compartment model describes the time dependent hydraulic conditions within the tailings and the surrounding aquifers taking into account hydraulic and geotechnical processes influencing the hydraulic properties of the tailings material. A simple geochemical approach taking into account sorption processes as well as retardation by applying a k d -approach was implemented to describe the contaminant release and transport within the hydraulic system. For uranium as the relevant contaminant the simple approach takes into account additional geochemical conditions influencing the mobility. Alternatively the model approach allows to include the results of detailed geochemical modelling of the individual tailings zones which is than used as source term for the modelling of the contaminant transport in the aquifer and to the receiving streams. (authors)

  3. A tale of two tails: Not just skin deep

    Directory of Open Access Journals (Sweden)

    Abhijit Dutta

    2015-01-01

    Full Text Available The dorsal cutaneous appendage or the so called human tail is a rare congenital anomaly protruding from the lumbo-sacro-coccygeal area. These caudal appendages are divided into true-tails and pseudo-tails. We report here two cases of congenital pseudo-tail with underlying spina bifida and lipo-meningocele. In this article we seek to emphasize that, as the skin and nervous systems are intimately linked by their similar ectodermal origin, a dorsal appendage may be regarded as a cutaneous marker of the underlying spinal dysraphism.

  4. Review of fugitive dust control for uranium mill tailings

    Energy Technology Data Exchange (ETDEWEB)

    Li, C.T.; Elmore, M.R.; Hartley, J.N.

    1983-01-01

    An immediate concern associated with the disposal of uranium mill tailings is that wind erosion of the tailings from an impoundment area will subsequently deposit tailings on surrounding areas. Pacific Northwest Laboratory (PNL), under contract to the U.S. Nuclear Regulatory Commission, is investigating the current technology for fugitive dust control. Different methods of fugitive dust control, including chemical, physical, and vegetative, have been used or tested on mill tailings piles. This report presents the results of a literature review and discussions with manufacturers and users of available stabilization materials and techniques.

  5. Ecological restoration alters microbial communities in mine tailings profiles

    Science.gov (United States)

    Li, Yang; Jia, Zhongjun; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

    2016-04-01

    Ecological restoration of mine tailings have impact on soil physiochemical properties and microbial communities. The surface soil has been a primary concern in the past decades, however it remains poorly understood about the adaptive response of microbial communities along the profile during ecological restoration of the tailings. In this study, microbial communities along a 60-cm profile were investigated in a mine tailing pond during ecological restoration of the bare waste tailings (BW) with two vegetated soils of Imperata cylindrica (IC) and Chrysopogon zizanioides (CZ) plants. Revegetation of both IC and CZ could retard soil degradation of mine tailing by stimulation of soil pH at 0-30 cm soils and altered the bacterial communities at 0-20 cm depths of the mine tailings. Significant differences existed in the relative abundance of the phyla Alphaproteobacteria, Deltaproteobacteria, Acidobacteria, Firmicutes and Nitrospira. Slight difference of bacterial communities were found at 30-60 cm depths of mine tailings. Abundance and activity analysis of nifH genes also explained the elevated soil nitrogen contents at the surface 0-20 cm of the vegetated soils. These results suggest that microbial succession occurred primarily at surface tailings and vegetation of pioneering plants might have promoted ecological restoration of mine tailings.

  6. Proceedings of the 15. annual British Columbia MEND ML/ARD workshop : the management of tailings and tailings impoundments

    International Nuclear Information System (INIS)

    2009-02-01

    This Mine Environment Neutral Drainage (MEND) workshop was held to promote the exchange of information and ideas on environmental protection and reclamation associated with mining. The workshop covered a broad spectrum of reclamation issues and the key environmental challenges facing the mining industry, such as acid mine drainage (AMD) control, and metal leaching and acid rock drainage (ML/ARD). The theme for the 2008 workshop was the management of tailings and tailings impoundments. Topics of discussion included hydrogeology and geochemistry; tailings disposal; mitigation; closure plans; and postclosure performance. The emphasis was on full-scale case studies, practical constraints and sustaining successful disposal strategies and remediation. The session on tailings management reviewed overarching policies and practices; methods of subaerial tailings disposal and case studies of tailings management; and detailed investigations of geochemical properties and processes. The conference featured 22 presentations, of which 4 have been catalogued separately for inclusion in this database. refs., tabs., figs

  7. Effects of Tail Clipping on Larval Performance and Tail Regeneration Rates in the Near Eastern Fire Salamander, Salamandra infraimmaculata.

    Directory of Open Access Journals (Sweden)

    Ori Segev

    Full Text Available Tail-tip clipping is a common technique for collecting tissue samples from amphibian larvae and adults. Surprisingly, studies of this invasive sampling procedure or of natural tail clipping--i.e., bites inflicted by predators including conspecifics--on the performance and fitness of aquatic larval stages of urodeles are scarce. We conducted two studies in which we assessed the effects of posterior tail clipping (~30 percent of tail on Near Eastern fire salamander (Salamandra infraimmaculata larvae. In a laboratory study, we checked regeneration rates of posterior tail-tip clipping at different ages. Regeneration rates were hump-shaped, peaking at the age of ~30 days and then decreasing. This variation in tail regeneration rates suggests tradeoffs in resource allocation between regeneration and somatic growth during early and advanced development. In an outdoor artificial pond experiment, under constant larval densities, we assessed how tail clipping of newborn larvae affects survival to, time to, and size at metamorphosis. Repeated measures ANOVA on mean larval survival per pond revealed no effect of tail clipping. Tail clipping had correspondingly no effect on larval growth and development expressed in size (mass and snout-vent length at, and time to, metamorphosis. We conclude that despite the given variation in tail regeneration rates throughout larval ontogeny, clipping of 30% percent of the posterior tail area seems to have no adverse effects on larval fitness and survival. We suggest that future use of this imperative tool for the study of amphibian should take into account larval developmental stage during the time of application and not just the relative size of the clipped tail sample.

  8. Effects of Tail Clipping on Larval Performance and Tail Regeneration Rates in the Near Eastern Fire Salamander, Salamandra infraimmaculata.

    Science.gov (United States)

    Segev, Ori; Polevikove, Antonina; Blank, Lior; Goedbloed, Daniel; Küpfer, Eliane; Gershberg, Anna; Koplovich, Avi; Blaustein, Leon

    2015-01-01

    Tail-tip clipping is a common technique for collecting tissue samples from amphibian larvae and adults. Surprisingly, studies of this invasive sampling procedure or of natural tail clipping--i.e., bites inflicted by predators including conspecifics--on the performance and fitness of aquatic larval stages of urodeles are scarce. We conducted two studies in which we assessed the effects of posterior tail clipping (~30 percent of tail) on Near Eastern fire salamander (Salamandra infraimmaculata) larvae. In a laboratory study, we checked regeneration rates of posterior tail-tip clipping at different ages. Regeneration rates were hump-shaped, peaking at the age of ~30 days and then decreasing. This variation in tail regeneration rates suggests tradeoffs in resource allocation between regeneration and somatic growth during early and advanced development. In an outdoor artificial pond experiment, under constant larval densities, we assessed how tail clipping of newborn larvae affects survival to, time to, and size at metamorphosis. Repeated measures ANOVA on mean larval survival per pond revealed no effect of tail clipping. Tail clipping had correspondingly no effect on larval growth and development expressed in size (mass and snout-vent length) at, and time to, metamorphosis. We conclude that despite the given variation in tail regeneration rates throughout larval ontogeny, clipping of 30% percent of the posterior tail area seems to have no adverse effects on larval fitness and survival. We suggest that future use of this imperative tool for the study of amphibian should take into account larval developmental stage during the time of application and not just the relative size of the clipped tail sample.

  9. Chaperone role for proteins p618 and p892 in the extracellular tail development of Acidianus two-tailed virus

    DEFF Research Database (Denmark)

    Scheele, Urte; Erdmann, Susanne; Ungewickell, Ernst J.

    2011-01-01

    The crenarchaeal Acidianus two-tailed virus (ATV) undergoes a remarkable morphological development, extracellularly and independently of host cells, by growing long tails at each end of a spindle-shaped virus particle. Initial work suggested that an intermediate filament-like protein, p800...... the interactions observed between the different protein and DNA components and to explain their possible structural and functional roles in extracellular tail development....

  10. THE NARROW X-RAY TAIL AND DOUBLE Hα TAILS OF ESO 137-002 IN A3627

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, B.; Lin, X. B.; Kong, X. [Center for Astrophysics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Sun, M. [Department of Physics, University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Ji, L. [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, Jiangsu 210008 (China); Sarazin, C. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Nulsen, P. E. J.; Forman, W.; Jones, C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Roediger, E. [Germany Hamburger Sternwarte, Universität Hamburg, Gojensbergsweg 112, D-21029 Hamburg (Germany); Donahue, M.; Voit, G. M., E-mail: xkong@ustc.edu.cn, E-mail: mingsun.cluster@gmail.com [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)

    2013-11-10

    We present the analysis of a deep Chandra observation of a ∼2 L{sub *} late-type galaxy, ESO 137-002, in the closest rich cluster A3627. The Chandra data reveal a long (∼>40 kpc) and narrow tail with a nearly constant width (∼3 kpc) to the southeast of the galaxy, and a leading edge ∼1.5 kpc from the galaxy center on the upstream side of the tail. The tail is most likely caused by the nearly edge-on stripping of ESO 137-002's interstellar medium (ISM) by ram pressure, compared to the nearly face-on stripping of ESO 137-001 discussed in our previous work. Spectral analysis of individual regions along the tail shows that the gas throughout it has a rather constant temperature, ∼1 keV, very close to the temperature of the tails of ESO 137-001, if the same atomic database is used. The derived gas abundance is low (∼0.2 solar with the single-kT model), an indication of the multiphase nature of the gas in the tail. The mass of the X-ray tail is only a small fraction (<5%) of the initial ISM mass of the galaxy, suggesting that the stripping is most likely at an early stage. However, with any of the single-kT, double-kT, and multi-kT models we tried, the tail is always 'over-pressured' relative to the surrounding intracluster medium (ICM), which could be due to the uncertainties in the abundance, thermal versus non-thermal X-ray emission, or magnetic support in the ICM. The Hα data from the Southern Observatory for Astrophysical Research show a ∼21 kpc tail spatially coincident with the X-ray tail, as well as a secondary tail (∼12 kpc long) to the east of the main tail diverging at an angle of ∼23° and starting at a distance of ∼7.5 kpc from the nucleus. At the position of the secondary Hα tail, the X-ray emission is also enhanced at the ∼2σ level. We compare the tails of ESO 137-001 and ESO 137-002, and also compare the tails to simulations. Both the similarities and differences of the tails pose challenges to the simulations

  11. A proactive approach to sustainable management of mine tailings

    Science.gov (United States)

    Edraki, Mansour; Baumgartl, Thomas

    2015-04-01

    The reactive strategies to manage mine tailings i.e. containment of slurries of tailings in tailings storage facilities (TSF's) and remediation of tailings solids or tailings seepage water after the decommissioning of those facilities, can be technically inefficient to eliminate environmental risks (e.g. prevent dispersion of contaminants and catastrophic dam wall failures), pose a long term economic burden for companies, governments and society after mine closure, and often fail to meet community expectations. Most preventive environmental management practices promote proactive integrated approaches to waste management whereby the source of environmental issues are identified to help make a more informed decisions. They often use life cycle assessment to find the "hot spots" of environmental burdens. This kind of approach is often based on generic data and has rarely been used for tailings. Besides, life cycle assessments are less useful for designing operations or simulating changes in the process and consequent environmental outcomes. It is evident that an integrated approach for tailings research linked to better processing options is needed. A literature review revealed that there are only few examples of integrated approaches. The aim of this project is to develop new tailings management models by streamlining orebody characterization, process optimization and rehabilitation. The approach is based on continuous fingerprinting of geochemical processes from orebody to tailings storage facility, and benchmark the success of such proactive initiatives by evidence of no impacts and no future projected impacts on receiving environments. We present an approach for developing such a framework and preliminary results from a case study where combined grinding and flotation models developed using geometallurgical data from the orebody were constructed to predict the properties of tailings produced under various processing scenarios. The modelling scenarios based on the

  12. Electrokinetic remediation of copper mine tailings

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Rojo, Adrián; Ottosen, Lisbeth M.

    2007-01-01

    in similar experiments but without the bipolar electrodes. The new electrokinetic remediation design was tested on copper mine tailings with different applied electric fields, remediation times and pre-treatment. The results showed that the copper removal was increased from 8% (applying 20V for 8 days......Important process parameters to optimize in electrokinetic soil remediation are those influencing remediation time and power consumption since these directly affect the cost of a remediation action. This work shows how the electrokinetic remediation (EKR) process could be improved by implementing...... bipolar electrodes in the porous material. The bipolar electrodes in EKR meant two improvements: (1) a shorter migration pathway for the contaminant, and (2) an increased electrical conductivity in the remediation system. All together the remediation proceeded faster with lower electrical resistance than...

  13. Hollywood blockbusters and long-tailed distributions

    Science.gov (United States)

    Sinha, S.; Raghavendra, S.

    2004-11-01

    Numerical data for all movies released in theaters in the USA during the period 1997-2003 are examined for the distribution of their popularity in terms of (i) the number of weeks they spent in the Top 60 according to the weekend earnings, and (ii) the box-office gross during the opening week, as well as, the total duration for which they were shown in theaters. These distributions show long tails where the most popular movies are located. Like the study of Redner [S. Redner, Eur. Phys. J. B 4, 131 (1998)] on the distribution of citations to individual papers, our results appear to be consistent with a power-law dependence of the rank distribution of gross revenues for the most popular movies with a exponent close to -1/2.

  14. The cost of decommissioning uranium mill tailings

    International Nuclear Information System (INIS)

    Lush, D.L.; Lendrum, C.; Hostovsky, C.; Eedy, W.; Ashbrook, A.

    1986-04-01

    This report identifies several key operations that are commonly carried out during decommissioning of tailings areas in the Canadian environment. These operations are unit costed for a generic site to provide a base reference case. The unit costs have also been scaled to the quantities required for the decommissioning of four Canadian sites and these scaled quantities compared with site-specific engineering cost estimates and actual costs incurred in carrying out the decommissioning activities. Variances in costing are discussed. The report also recommends a generic monitoring regime upon which both short- and longer-term environmental monitoring costs are calculated. Although every site must be addressed as a site-specific case, and monitoring programs must be tailored to fit a specific site, it would appear that for the conventional decommissioning and monitoring practices that have been employed to date, costs can be reasonably estimated when site-specific conditions are taken into account

  15. Studies on Arsenic Release and its Mitigation from Tailings Dam ...

    African Journals Online (AJOL)

    Studies on Arsenic Release and its Mitigation from Tailings Dam Using Nanomagnetite Particles. ... Ghana Mining Journal ... Abstract. Knowledge of the geochemistry of As in tailings material after beneficiation of gold-bearing sulphidic ores is necessary to comprehend the nature, stability and mobilization of As into the ...

  16. Mineralogy of Tailings Dump around Selebi Phikwe Nickel-Copper ...

    African Journals Online (AJOL)

    This study aimed at mineralogically characterizing the tailings dump emanating from the mining and smelting of nickel-copper (Ni-Cu) at Selebi Phikwe, Botswana, Southern Africa. Samples of tailings dump around the Selebi Phikwe Ni-Cu plant were studied using petrographic microscopy and X-ray Powder Diffraction ...

  17. Thresher sharks use tail-slaps as a hunting strategy.

    Science.gov (United States)

    Oliver, Simon P; Turner, John R; Gann, Klemens; Silvosa, Medel; D'Urban Jackson, Tim

    2013-01-01

    The hunting strategies of pelagic thresher sharks (Alopias pelagicus) were investigated at Pescador Island in the Philippines. It has long been suspected that thresher sharks hunt with their scythe-like tails but the kinematics associated with the behaviour in the wild are poorly understood. From 61 observations recorded by handheld underwater video camera between June and October 2010, 25 thresher shark shunting events were analysed. Thresher sharks employed tail-slaps to debilitate sardines at all times of day. Hunting events comprised preparation, strike, wind-down recovery and prey item collection phases, which occurred sequentially. Preparation phases were significantly longer than the others, presumably to enable a shark to windup a tail-slap. Tail-slaps were initiated by an adduction of the pectoral fins, a manoeuvre that changed a thresher shark's pitch promoting its posterior region to lift rapidly, and stall its approach. Tail-slaps occurred with such force that they may have caused dissolved gas to diffuse out of the water column forming bubbles. Thresher sharks were able to consume more than one sardine at a time, suggesting that tail-slapping is an effective foraging strategy for hunting schooling prey. Pelagic thresher sharks appear to pursue sardines opportunistically by day and night, which may make them vulnerable to fisheries. Alopiids possess specialist pectoral and caudal fins that are likely to have evolved, at least in part, for tail-slapping. The evidence is now clear; thresher sharks really do hunt with their tails.

  18. Lifshitz Tails for the Interband Light Absorption Coefficient

    Indian Academy of Sciences (India)

    In this paper we consider the interband light absorption coefficient (ILAC) for various models. We show that at the lower and upper edges of the spectrum the Lifshitz tails behaviour of the density of states implies similar behaviour for the ILAC at appropriate energies. The Lifshitz tails property is also exhibited at some points ...

  19. Estimating contaminant discharge rates from stabilized uranium tailings embankments

    International Nuclear Information System (INIS)

    Weber, M.F.

    1986-01-01

    Estimates of contaminant discharge rates from stabilized uranium tailings embankments are essential in evaluating long-term impacts of tailings disposal on groundwater resources. Contaminant discharge rates are a function of water flux through tailings covers, the mass and distribution of tailings, and the concentrations of contaminants in percolating pore fluids. Simple calculations, laboratory and field testing, and analytical and numerical modeling may be used to estimate water flux through variably-saturated tailings under steady-state conditions, which develop after consolidation and dewatering have essentially ceased. Contaminant concentrations in water discharging from the tailings depend on tailings composition, leachability and solubility of contaminants, geochemical conditions within the embankment, tailings-water interactions, and flux of water through the embankment. These concentrations may be estimated based on maximum reported concentrations, pore water concentrations, extrapolations of column leaching data, or geochemical equilibria and reaction pathway modeling. Attempts to estimate contaminant discharge rates should begin with simple, conservative calculations and progress to more-complicated approaches, as necessary

  20. Economic Mineral Potentials Of Tailing Dumps From Alluvial Mining ...

    African Journals Online (AJOL)

    Several tonnes of mine tailing dumps abound in the alluvial tin mining areas of the Jos Plateau. These tailings are considered low in contents of cassiterite, columbite, tantalite, zircon and other minerals normally won from tin mining. Four of these dumps in four different mines located in Barkin Ladi (BL), Gurum (GM), Sabon ...

  1. Uranium mill tailings regulation and the generic environmental impact statement

    International Nuclear Information System (INIS)

    Rogers, V.C.

    1980-01-01

    The following topics are discussed: the history of the Canadian uranium industry; the Canadian management of uranium mining wastes; Canadian federal and provincial effluent guidelines for radium-226; tailings and mine water management; backfill; liquid effluents from tailings storage; barium chloride treatment; mine water (Fay Mine); mine water (Dubyna Mine); and revegetation. 22 refs

  2. Risk factors for canine tail chasing behaviour in Japan.

    Science.gov (United States)

    Goto, Akiko; Arata, Sayaka; Kiyokawa, Yasushi; Takeuchi, Yukari; Mori, Yuji

    2012-06-01

    The aim of this study was to investigate the risk factors for tail chasing behaviour that occurs when a dog spins in tight circles to chase its tail, sometimes biting it. The behaviour is a sign of canine compulsive disorder (CD). A questionnaire about tail chasing behaviour and general information about the animals was used to collect data on seven breeds of pet dogs. The data were gathered at a dog event and at veterinary practices. To determine which variables were associated with tail chasing behaviour, stepwise multiple regression analyses were performed. Regardless of cohort, 'breed' and 'source of acquisition' were significantly associated with tail chasing behaviour. Using a chi-square test, the association between 'source of acquisition' and the behaviour was examined separately in two breeds (Shiba inu and Dachshund) that had the largest number of individuals chasing their tails accompanied by biting and/or growling at them. This factor showed a significant and consistent association across the two breeds. With respect to the risk factors of 'breed' and 'source of acquisition', high percentages of Shiba inu and dogs originating from pet stores were included in the group chasing their tails with biting and/or growling. The results suggest that distinct risk factors exist for tail chasing behaviour and such factors appear to be regulated by both genetics and the environment. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Human born with a tail: A case report

    African Journals Online (AJOL)

    Histopathological examination revealed that the tail-like structure contained skin, muscle and adipose tissue only. e infant recovered uneventfully and no neurological de cit was evident on follow-up until 12 months of age. Fig. 1. e dorsal tail. Fig. 2. Magnetic resonance imaging scan showing spina bifida in the lumbosacral.

  4. Tail index and quantile estimation with very high frequency data

    NARCIS (Netherlands)

    J. Daníelsson (Jón); C.G. de Vries (Casper)

    1997-01-01

    textabstractA precise estimation of the tail shape of forex returns is of critical importance for proper risk assessment. We improve upon the efficiency of conventional estimators that rely on a first order expansion of the tail shape, by using the second order expansion. Here we advocate a moments

  5. Assessment of Pollution Potential of Cyanide-Bearing Tailings Dam ...

    African Journals Online (AJOL)

    This study ascertained the types of chemical species that are formed in tailings material of gold leaching plants and assessed their short and long term pollution potential capabilities. The results revealed that chemical, biochemical and geochemical reactions were occurring in the tailings material; producing complexed ...

  6. Probing the density tail of radioactive nuclei with antiprotons

    CERN Document Server

    Obertelli, Alexandre; Uesaka, Tomohiro; Corsi, Anna; Pollacco, Emmanuel; Flavigny, Freddy

    2017-01-01

    We propose an experiment to determine the proton and neutron content of the radial density tail in short-lived nuclei. The objectives are to (i) to evidence new proton and neutron halos, (ii) to understand the development of neutron skins in medium-mass nuclei, (iii) to provide a new observable that characterises the density tail of short-lived nuclei.

  7. Characterisation of gold tailings dams of the Witwatersrand Basin ...

    African Journals Online (AJOL)

    2006-10-04

    Oct 4, 2006 ... bentonite layer between the 9th and 10th meter level to minimise vertical air flow from the bottom of the tailings dams. ... m depth with bentonite. Due to the age of the dams, and the fact that they ...... from Cyanide-Rich Gold Mine. Tailings. Unpublished M.Sc. Thesis, The University of New Bruns- wick, USA.

  8. Black-tailed prairie dog status and future conservation planning

    Science.gov (United States)

    Daniel W. Mulhern; Craig J. Knowles

    1997-01-01

    The black-tailed prairie dog is one of five prairie dog species estimated to have once occupied up to 100 million ha or more in North America. The area occupied by black-tailed prairie dogs has declined to approximately 2% of its former range. Conversion of habitat to other land uses and widespread prairie dog eradication efforts combined with sylvatic plague,

  9. Trace elements contamination of soils around gold mine tailings ...

    African Journals Online (AJOL)

    This study investigated the issue of tailings dams as a potential source of trace elements contamination in soils at the Obuasi gold mine in Ghana. Soil samples taken from depths of up to 12 cm and within a radius of 400 m from the tailings dams (active and recommissioned), were analysed for As, Cu, Pb and. Zn using ...

  10. Individual piglets' contribution to the development of tail biting

    NARCIS (Netherlands)

    Zonderland, J.J.; Kemp, B.; Bracke, M.B.M.; Hartog, den L.A.; Spoolder, H.A.M.

    2011-01-01

    Conflicting hypotheses exist about the contribution of individual pigs to the development of a tail-biting outbreak, but there is limited quantitative information to support or dismiss them. This study aims to quantify the development of tail-biting behaviour at pen and individual piglet level,

  11. Non-equilibrium and band tailing in organic conductors

    Indian Academy of Sciences (India)

    The concept of band tailing with focal point and width of the tail from IR absorption spectra of different organic conductors is found valid even for thermal and elastic changes. The experimental situations like change of solvents, method of preparation, applied pressure and pressure cycle apart from compositions is analyzed ...

  12. Gold tailings as a source of waterborne uranium contamination of ...

    African Journals Online (AJOL)

    Tailings deposits from gold and uranium (U) mining in the Witwatersrand basin often contain elevated levels of radioactive and chemo-toxic heavy metals. Through seepage, dissolved U and other metals migrate from tailings deposits via groundwater into adjacent fluvial systems. The subsequent transport through flowing ...

  13. Gold tailings as a source of waterborne uranium contamination of ...

    African Journals Online (AJOL)

    driniev

    2004-04-02

    Apr 2, 2004 ... Dissolved uranium (U) from the tailings deposits of various gold mines in South Africa has been found to migrate via seepage and groundwater ... Due to elevated concentrations of U and other heavy metals in tailings deposits ... dissolved metals migrate into the underlying groundwater and eventually seep ...

  14. A COUNTER-CURRENT HEAT EXCHANGE SYSTEM IN THE TAIL ...

    African Journals Online (AJOL)

    Under such conditions the arterial blood supplying the tail skin is several degrees cooler than the core temperature ... A thermoregulatory function for the vervet monkey tail has been suggested from observa- tions on the ..... Considering the relative thickness of the human fore-arm and vervet caudal arteries at the respective ...

  15. A Glimpse of the genomic diversity of haloarchaeal tailed viruses

    Directory of Open Access Journals (Sweden)

    Ana eSencilo

    2014-03-01

    Full Text Available Tailed viruses are the most common isolates infecting prokaryotic hosts residing hypersaline environments. Archaeal tailed viruses represent only a small portion of all characterized tailed viruses of prokaryotes. But even this small dataset revealed that archaeal tailed viruses have many similarities to their counterparts infecting bacteria, the bacteriophages. Shared functional homologues and similar genome organizations suggested that all microbial tailed viruses have common virion architectural and assembly principles. Recent structural studies have provided evidence justifying this thereby grouping archaeal and bacterial tailed viruses into a single lineage. Currently there are 17 haloarchaeal tailed viruses with entirely sequenced genomes. Nine viruses have at least one close relative among the 17 viruses and, according to the similarities, can be divided into three groups. Two other viruses share some homologues and therefore are distantly related, whereas the rest of the viruses are rather divergent (or singletons. Comparative genomics analysis of these viruses offers a glimpse into the genetic diversity and structure of haloarchaeal tailed virus communities.

  16. Structural Conservation of the Myoviridae Phage Tail Sheath Protein Fold

    Energy Technology Data Exchange (ETDEWEB)

    Aksyuk, Anastasia A.; Kurochkina, Lidia P.; Fokine, Andrei; Forouhar, Farhad; Mesyanzhinov, Vadim V.; Tong, Liang; Rossmann, Michael G. (SOIBC); (Purdue); (Columbia)

    2012-02-21

    Bacteriophage phiKZ is a giant phage that infects Pseudomonas aeruginosa, a human pathogen. The phiKZ virion consists of a 1450 {angstrom} diameter icosahedral head and a 2000 {angstrom}-long contractile tail. The structure of the whole virus was previously reported, showing that its tail organization in the extended state is similar to the well-studied Myovirus bacteriophage T4 tail. The crystal structure of a tail sheath protein fragment of phiKZ was determined to 2.4 {angstrom} resolution. Furthermore, crystal structures of two prophage tail sheath proteins were determined to 1.9 and 3.3 {angstrom} resolution. Despite low sequence identity between these proteins, all of these structures have a similar fold. The crystal structure of the phiKZ tail sheath protein has been fitted into cryo-electron-microscopy reconstructions of the extended tail sheath and of a polysheath. The structural rearrangement of the phiKZ tail sheath contraction was found to be similar to that of phage T4.

  17. Fat-tailed distributions data, diagnostics and dependence

    CERN Document Server

    Cooke, Roger M; Misiewicz, Jolanta

    2014-01-01

    This title is written for the numerate nonspecialist, and hopes to serve three purposes. First it gathers mathematical material from diverse but related fields of order statistics, records, extreme value theory, majorization, regular variation and subexponentiality. All of these are relevant for understanding fat tails, but they are not, to our knowledge, brought together in a single source for the target readership. Proofs that give insight are included, but for most fussy calculations the reader is referred to the excellent sources referenced in the text. Multivariate extremes are not treated. This allows us to present material spread over hundreds of pages in specialist texts in twenty pages. Chapter 5 develops new material on heavy tail diagnostics and gives more mathematical detail. Since variances and covariances may not exist for heavy tailed joint distributions, Chapter 6 reviews dependence concepts for certain classes of heavy tailed joint distributions, with a view to regressing heavy tailed variabl...

  18. The Rum Jungle tailings dam - chemical profile of the subsoil

    International Nuclear Information System (INIS)

    Lowson, R.T.; Evans, J.V.; Sarbutt, J.V.; Sinclair, G.; Folk, E.

    1987-09-01

    In a survey of soils below the Rum Jungle uranium mine tailings dam, parameters measured were pH, moisture content, particle distribution, total Cu, water-extractable Cu, Ca and SO 4 and acid-extractable Ra. The cation profile had a marked discontinuity at the soil/tailings interface. This was attributed to a complex hydrogeology and to the presence of a reduction zone in the soil immediately below the tailings. The tailings acted as an aquaclude to a water table which fluctuated with the monsoonal season. The reduction zone acted as a cation trap, preventing cation transport. The radium concentration dropped to levels acceptable to public health within a few centimetres of the soil/tailings interface

  19. Jump Tails, Extreme Dependencies, and the Distribution of Stock Returns

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Todorov, Viktor

    We provide a new framework for estimating the systematic and idiosyncratic jump tail risks in financial asset prices. The theory underlying our estimates are based on in-fill asymptotic arguments for directly identifying the systematic and idiosyncratic jumps, together with conventional long......-span asymptotics and Extreme Value Theory (EVT) approximations for consistently estimating the tail decay parameters and asymptotic tail dependencies. On implementing the new estimation procedures with a panel of highfrequency intraday prices for a large cross-section of individual stocks and the aggregate S&P 500...... market portfolio, we find that the distributions of the systematic and idiosyncratic jumps are both generally heavy-tailed and not necessarily symmetric. Our estimates also point to the existence of strong dependencies between the market-wide jumps and the corresponding systematic jump tails for all...

  20. Micropore Structure of Cement-Stabilized Gold Mine Tailings

    Directory of Open Access Journals (Sweden)

    Joon Kyu Lee

    2018-03-01

    Full Text Available Mine tailings have often to be stabilized by mixing them with cementing agents. In this study, the pore structure of gold tailings stabilized with Portland cement was evaluated by means of mercury intrusion porosimetry. The investigation was conducted on samples prepared with different fractions of tailings and cement as well as on samples activated with elevated temperature curing and chemical (CaCl2 addition. It was observed that all mixed samples exhibit a mono-modal pore size distribution, indicating that the cement-stabilized tailings are characterized by a single-porosity structure. The results also showed that the higher fraction of tailings and cement leads to a dense and finer pore structure. The total porosity of mixture samples decreases with increasing curing temperature and CaCl2 concentration due to the acceleration of hydration reaction.

  1. Accelerated aging tests of liners for uranium mill tailings disposal

    International Nuclear Information System (INIS)

    Barnes, S.M.; Buelt, J.L.; Hale, V.Q.

    1981-11-01

    This document describes the results of accelerated aging tests to determine the long-term effectiveness of selected impoundment liner materials in a uranium mill tailings environment. The study was sponsored by the US Department of Energy under the Uranium Mill Tailings Remedial Action Project. The study was designed to evaluate the need for, and the performance of, several candidate liners for isolating mill tailings leachate in conformance with proposed Environmental Protection Agency and Nuclear Regulatory Commission requirements. The liners were subjected to conditions known to accelerate the degradation mechanisms of the various liners. Also, a test environment was maintained that modeled the expected conditions at a mill tailings impoundment, including ground subsidence and the weight loading of tailings on the liners. A comparison of installation costs was also performed for the candidate liners. The laboratory testing and cost information prompted the selection of a catalytic airblown asphalt membrane and a sodium bentonite-amended soil for fiscal year 1981 field testing

  2. Diagnostic analysis of electrodialysis in mine tailing materials

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Ribeiro, Alexandra B.; Mateus, Eduardo

    2007-01-01

    types of extracting solutions, such as distilled water, or H2SO4 at pH 0, H2SO4 + HNO3 at pH 1.9 and 4.2 or NH4Cl, in the electrodialytic cell, was investigated. From all the experiments, H2O presented the best performance for the electro-removal of Cu from the old deposited mine tailings, achieving 63......Removal of heavy metals from mine tailings and soil contaminated by copper mining activities was studied under batch electrodialytic conditions. Two types of mine tailings were treated: (i) freshly produced tailings coming directly from the flotation process, and (ii) tailings deposited...... removal results of a soil sampled close to an abandoned cupric pyrite mine-mainly polluted with lead (around 3800ppm) are also presented. The results show that the heavy metals could be mobilized in all three contaminated solid materials using the electrodialytic process. The effect of adding different...

  3. A tale too long for a tail too short? : identification of characteristics in pigs related to tail biting and other oral manipulations directed at conspecifics

    NARCIS (Netherlands)

    Ursinus, W.W.

    2014-01-01

    Ursinus, W.W. (2014). A tale too long for a tail too short? Identification of characteristics in pigs related to tail biting and other oral manipulations directed at conspecifics. PhD thesis, Wageningen University, The Netherlands. Tail biting in pigs, i.e. the chewing on and biting in tails of

  4. Flea abundance on black-tailed prairie dogs (Cynomys ludovicianus) increases during plague epizootics.

    Science.gov (United States)

    Tripp, Daniel W; Gage, Kenneth L; Montenieri, John A; Antolin, Michael F

    2009-06-01

    Black-tailed prairie dogs (Cynomys ludovicianus) on the Great Plains of the United States are highly susceptible to plague, caused by the bacterium Yersinia pestis, with mortality on towns during plague epizootics often approaching 100%. The ability of flea-borne transmission to sustain disease spread has been questioned because of inefficiency of flea vectors. However, even with low individual efficiency, overall transmission can be increased if flea abundance (the number of fleas on hosts) increases. Changes in flea abundance on hosts during plague outbreaks were recorded during a large-scale study of plague outbreaks in prairie dogs in north central Colorado during 3 years (2004-2007). Fleas were collected from live-trapped black-tailed prairie dogs before and during plague epizootics and tested by PCR for the presence of Y. pestis. The predominant fleas were two prairie dog specialists (Oropsylla hirsuta and Oropsylla tuberculata cynomuris), and a generalist flea species (Pulex simulans) was also recorded from numerous mammals in the area. The three species differ in seasonal abundance, with greatest abundance in spring (February and March) and fall (September and October). Flea abundance and infestation intensity increased during epizootics and were highest on prairie dogs with Y. pestis-infected fleas. Seasonal occurrence of epizootics among black-tailed prairie dogs was found to coincide with seasonal peaks in flea abundance. Concentration of infected fleas on surviving animals may account for rapid spread of plague during epizootics. In particular, the role of the generalist flea P. simulans was previously underappreciated.

  5. Behavioural and Brain Gene Expression Profiling in Pigs during Tail Biting Outbreaks - Evidence of a Tail Biting Resistant Phenotype.

    Science.gov (United States)

    Brunberg, Emma; Jensen, Per; Isaksson, Anders; Keeling, Linda J

    2013-01-01

    Abnormal tail biting behaviour is a major welfare problem for pigs receiving the behaviour, as well as an indication of decreased welfare in the pigs performing it. However, not all pigs in a pen perform or receive tail biting behaviour and it has recently been shown that these 'neutral' pigs not only differ in their behaviour, but also in their gene expression compared to performers and receivers of tail biting in the same pen. To investigate whether this difference was linked to the cause or a consequence of them not being involved in the outbreak of tail biting, behaviour and brain gene expression was compared with 'control' pigs housed in pens with no tail biting. It was shown that the pigs housed in control pens performed a wider variety of pig-directed abnormal behaviour (belly nosing 0.95±1.59, tail in mouth 0.31±0.60 and 'other' abnormal 1.53±4.26; mean±S.D) compared to the neutral pigs (belly nosing 0.30±0.62, tail in mouth 0.13±0.50 and "other" abnormal 0.42±1.06). With Affymetrix gene expression arrays, 107 transcripts were identified as differently expressed (pbiting in the same pen in an earlier study. Hence, the different expression of these genes cannot be a consequence of the neutral pigs not being involved in tail biting behaviour, but rather linked to the cause contributing to why they were not involved in tail biting interactions. These neutral pigs seem to have a genetic and behavioural profile that somehow contributes to them being resistant to performing or receiving pig-directed abnormal behaviour, such as tail biting, even when housed in an environment that elicits that behaviour in other pigs.

  6. Behavioural and Brain Gene Expression Profiling in Pigs during Tail Biting Outbreaks – Evidence of a Tail Biting Resistant Phenotype

    Science.gov (United States)

    Brunberg, Emma; Jensen, Per; Isaksson, Anders; Keeling, Linda J.

    2013-01-01

    Abnormal tail biting behaviour is a major welfare problem for pigs receiving the behaviour, as well as an indication of decreased welfare in the pigs performing it. However, not all pigs in a pen perform or receive tail biting behaviour and it has recently been shown that these ‘neutral’ pigs not only differ in their behaviour, but also in their gene expression compared to performers and receivers of tail biting in the same pen. To investigate whether this difference was linked to the cause or a consequence of them not being involved in the outbreak of tail biting, behaviour and brain gene expression was compared with ‘control’ pigs housed in pens with no tail biting. It was shown that the pigs housed in control pens performed a wider variety of pig-directed abnormal behaviour (belly nosing 0.95±1.59, tail in mouth 0.31±0.60 and ‘other‘ abnormal 1.53±4.26; mean±S.D) compared to the neutral pigs (belly nosing 0.30±0.62, tail in mouth 0.13±0.50 and “other“ abnormal 0.42±1.06). With Affymetrix gene expression arrays, 107 transcripts were identified as differently expressed (pbiting in the same pen in an earlier study. Hence, the different expression of these genes cannot be a consequence of the neutral pigs not being involved in tail biting behaviour, but rather linked to the cause contributing to why they were not involved in tail biting interactions. These neutral pigs seem to have a genetic and behavioural profile that somehow contributes to them being resistant to performing or receiving pig-directed abnormal behaviour, such as tail biting, even when housed in an environment that elicits that behaviour in other pigs. PMID:23824700

  7. Development of a methodology to accelerate a spontaneous grass colonization in a tailings storage facility under semiarid mediterranean climate type

    Science.gov (United States)

    Ginocchio, Rosanna; Arellano, Eduardo; Morales-Ladron de Guevara, Arturo

    2016-04-01

    Phytostabilization of massive mine tailings (>400 he) under semiarid environments is challenging, particularly when no organic amendments are locally available and no irrigation is possible. Increasing tendency for reprocessing old tailings to recover valued metals further pioneer the need for simple but effective plant covers. The choice of plant species and form of management are thus very important. CODELCO-Chile chose the Cauquenes post-operational tailings storage facility (TFS; 700 ha), that will be reprocessed for copper and other elements in the near future, to evaluate efficacy of the phytostabilization technology under semiarid conditions in central Chile. Surface application of a polymer (Soiltac TM) has been used for wind control of tailings but phytostabilization is considered as a best cost-effective alternative. A field study was performed to define a management program to improve the establishment and cover of an annual native grass (Vulpia myuros var. megalura), a spontaneous colonizer of the TSF. Considered management factors were control of macro herbivores (with and without fence), macronutrient improvement (with and without application of N-rich foliar fertilizer), and improvement of seed retention in the substrate (with and without small-scale rugosity; with and without lived wind-breakers; with and without mechanical wind-breakers). Each treatment was replicated three times and established in 2 m x 2 m quadrats. Plant response variables were monitored after 1 and 2 grass growing seasons. Application of N-rich foliar fertilizer and any wind control mechanism for seed retention in the substrate were effective for significantly improving both grass cover and biomass production in time, irrespective of macro-herbivore control. Seed production was significantly improved when macro herbivores were excluded and was positively and significantly correlated to vegetative biomass production. When applying this management program for tailings

  8. Impact of flocculation on flotation tailing's hydro-cycloning properties

    Directory of Open Access Journals (Sweden)

    Knežević Dinko N.

    2014-01-01

    Full Text Available Research results of hydro-cycloning of flocculated and non-flocculated flotation tailing from the lead and zinc open pit mine 'Suplja stijena', Sula - Montenegro have been shown in this paper. Reason for this research was finding conditions in order to separate fraction that is suitable for embankment erection. Flotation tailings has been tested in the very state that it goes out from the flotation process and tailings which is flocculated by anionic flocculant. The object was to determine the impact of flocculation on properties of hydro-cycloning products and disposal process. In hydro-cycloning process greater underflow mass is being separated with non-flocculated tailing. Values of geomechanical parameters are significantly different, especially hydro-cyclone's underflow. All geomechanical parameters of hydro-cyclone's underflow are suitable for erecting embankment which shall be made from non-flocculated tailing. Underflow drainage of non-flocculated tailing is faster while overflow drainage is slower and problematic with both tailings.

  9. Quasi-steady state aerodynamics of the cheetah tail

    Directory of Open Access Journals (Sweden)

    Amir Patel

    2016-08-01

    Full Text Available During high-speed pursuit of prey, the cheetah (Acinonyx jubatus has been observed to swing its tail while manoeuvring (e.g. turning or braking but the effect of these complex motions is not well understood. This study demonstrates the potential of the cheetah's long, furry tail to impart torques and forces on the body as a result of aerodynamic effects, in addition to the well-known inertial effects. The first-order aerodynamic forces on the tail are quantified through wind tunnel testing and it is observed that the fur nearly doubles the effective frontal area of the tail without much mass penalty. Simple dynamic models provide insight into manoeuvrability via simulation of pitch, roll and yaw tail motion primitives. The inertial and quasi-steady state aerodynamic effects of tail actuation are quantified and compared by calculating the angular impulse imparted onto the cheetah's body and its shown aerodynamic effects contribute to the tail's angular impulse, especially at the highest forward velocities.

  10. Leachability of radioactive constituents from uranium mine tailings

    International Nuclear Information System (INIS)

    Constable, T.W.

    1987-04-01

    A series of long-term studies were conducted both to examine the leachability of major constituents (acidity, TDS) and radioisotopes from uranium mining/milling tailings and settling pond sludges, and to assess the effect of two treatment methods (solidification and vegetation) on leachate characteristics. Four bench-scale experiments were conducted to examine the leachability of: 1) old tailings and those containing a large portion of (Ba,Ra)SO 4 sludges; 2) untreated and solidified (Ba,Ra)SO 4 sludges located at the bottom of settling ponds; 3) new tailings that had been vegetated or solidified; and 4) new tailings subject to varying flow rates. A fifth study was conducted to examine the microbiology of Experiments 2 and 3. In addition, the lysimeter solids remaining in the old tailings at the end of Experiment 1 were characterized through chemical and radionuclide analyses and Scanning Electron Microscope-X-ray Emission and Mossbauer Spectroscopy techniques. This report provides an extensive database of temporal variations in leachate characteristics under both normal and accelerated water application rates. It also presents hypotheses of possible leaching mechanisms in the wastes that could explain the observed data, and conceptual model of tailings leaching processes which integrates the results of all the tailings experiments

  11. Utilisation of iron ore tailings as aggregates in concrete

    Directory of Open Access Journals (Sweden)

    Francis Atta Kuranchie

    2015-12-01

    Full Text Available Sustainable handling of iron ore tailings is of prime concern to all stakeholders who are into iron ore mining. This study seeks to add value to the tailings by utilising them as a replacement for aggregates in concrete. A concrete mix of grade 40 MPa was prepared in the laboratory with water–cement ratio of 0.5. The concrete were cured for 1, 2, 3, 7, 14 and 28 days. The properties of the concrete such as workability, durability, density, compressive strength and indirect tensile strength were tested. A controlled mix of concrete was also prepared in similar way using conventional materials and the results were compared with the tailings concrete. It was found that the iron ore tailings may be utilised for complete replacement for conventional aggregates in concrete. The iron ore tailings aggregates concrete exhibited a good mechanical strength and even in the case of compressive strength, there was an improvement of 11.56% over conventional aggregates concrete. The indirect tensile strength did not improve against the control mix due high content of fines in the tailings aggregates but showed 4.8% improvement compared with the previous study where the conventional fine aggregates was partially replaced by 20% with iron ore tailings.

  12. Quasi-steady state aerodynamics of the cheetah tail.

    Science.gov (United States)

    Patel, Amir; Boje, Edward; Fisher, Callen; Louis, Leeann; Lane, Emily

    2016-08-15

    During high-speed pursuit of prey, the cheetah (Acinonyx jubatus) has been observed to swing its tail while manoeuvring (e.g. turning or braking) but the effect of these complex motions is not well understood. This study demonstrates the potential of the cheetah's long, furry tail to impart torques and forces on the body as a result of aerodynamic effects, in addition to the well-known inertial effects. The first-order aerodynamic forces on the tail are quantified through wind tunnel testing and it is observed that the fur nearly doubles the effective frontal area of the tail without much mass penalty. Simple dynamic models provide insight into manoeuvrability via simulation of pitch, roll and yaw tail motion primitives. The inertial and quasi-steady state aerodynamic effects of tail actuation are quantified and compared by calculating the angular impulse imparted onto the cheetah's body and its shown aerodynamic effects contribute to the tail's angular impulse, especially at the highest forward velocities. © 2016. Published by The Company of Biologists Ltd.

  13. Making a Magnetorheological Fluid from Mining Tailings

    Science.gov (United States)

    Quitian, G.; Saldarriaga, W.; Rojas, N.

    2017-12-01

    We have obtained magnetite mining tailings and used it to fabricate a magnetorheological fluid (MRF). Mineralogical and morphological characteristics were determined using X-ray diffraction (XRD) and energy dispersive spectrometry (EDS), as well as size and geometry for the obtained magnetite. Finally, the fabricated MRF was rheologically characterized in a device attached to a rheometer. The application of a magnetic field of 0.12 Tesla can increase the viscosity of the MRF by more than 400 pct. A structural formation should occur within the fluid by a reordering of particles into magnetic columns, which are perpendicular to the flow direction. These structures give the fluid an increased viscosity. As the magnetic field increases, the structure formed is more resistant, resulting in an increased viscosity. One can appreciate that with a value equal to or less than 0.06 Tesla of applied magnetic field, many viscosity values associated with the work area of the oils can be achieved (0.025 and 0.34 Pa s).

  14. Flocculation of flotation tailings using thermosensitive polymers

    Directory of Open Access Journals (Sweden)

    Bogacz Wojciech

    2017-09-01

    Full Text Available The key feature of thermosensitive polymers is the reversible transition between the hydrophilic and hydrophopic forms depending on the temperature. Although the main research efforts are focused on their application in different kinds of drug delivery systems, this phenomenon also allows one to precisely control the stability of solid-liquid dispersions. In this paper research on the application of poly(N-isopropylacrylamide copolymers in processing of minerals is presented. In the experiments tailings from flotation plant of one of the coal mines of Jastrzębska Spółka Węglowa S.A. (Poland were used. A laser particle sizer Fritsch Analysette 22 was used in order to determine the Particle Size Distribution (PSD. It was proved that there are some substantial issues associated with the application of thermosensitive polymers in industrial practice which may exclude them from the common application. High salinity of suspension altered the value of Lower Critical Solution Temperature (LCST. Moreover, the co-polymers used in research proved to be efficient flocculating agents without any temperature rise. Finally, the dosage needed to achieve steric stabilization of suspension was greatly beyond economic justification.

  15. Arsenic readily released to pore waters from buried mill tailings

    International Nuclear Information System (INIS)

    Mahoney, John; Langmuir, Donald; Gosselin, Neil; Rowson, John

    2005-01-01

    At the McClean Lake Operation in the Athabasca Basin of northern Saskatchewan, the untreated acid raffinate solutions associated with U mill tailings contain up to 700 mg/L dissolved As. To reduce the concentration of As and other contaminants in acid tailing slurries at the JEB mill at McClean Lake, ferric sulfate may be added to the acid raffinates to assure that their molar Fe/As ratio equals or exceeds 3. Tailings slurries are then neutralized with lime to pH 4, and subsequently to pH 7-8. The neutralized tailings contain minerals from the original ore, which are chiefly quartz, illite, kaolinite and chlorite, and precipitated (secondary) minerals that include gypsum, scorodite, annabergite, hydrobasaluminite and ferrihydrite. Most of the As is associated with the secondary arsenate minerals, scorodite and annabergite. However, a few percent is adsorbed and/or co-precipitated, mainly by ferrihydrite. Of major concern to provincial and federal regulators is the risk that significant amounts of As might be released from the tailings to pore waters after their subaqueous disposal in the tailings management facility. A laboratory study was performed to address this issue, measuring readily desorbed As using a method known as equilibrium partitioning in closed systems (EPICS). The EPICS method was selected because it employs a leaching solution that, except for its As concentration, is identical in composition to the neutralized raffinate in contact with the tailings. Laboratory experiments and modeling results demonstrated that the As that could be readily released to pore waters is about 0.2% of the total As in the tailings. Long-term, such releases may contribute no more than a few mg/L of dissolved As to tailings pore waters

  16. Summary of the engineering assessment of inactive uranium mill tailings

    International Nuclear Information System (INIS)

    1981-07-01

    The Grand Junction site has been reevaluated in order to revise the october 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Grand Junction, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 1.9 million tons of tailings at the Grand Junction site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation are also factors. The eight alternative actions presented herein range from millsite and off-site decontamination with the addition of 3 m of stabilization cover material (Option I), to removal of the tailings to remote disposal sites and decontamination of the tailings site (Option II through VIII). Cost estimates for the eight options range from about $10,200,000 for stabilization in-place to about $39,500,000 for disposal in the DeBeque area, at a distance of about 35 mi, using transportation by rail. If transportation to DeBeque were by truck, the cost is estimated to be about $41,900,000. Three prinicpal alternatives for the reprocessing of the Grand Junction tailings were examined: (a) heap leaching; (b) treatment at an existing mill; and (c) reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $200/lb by heap leach and $150/lb by conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery appears not to be economically attractive

  17. Risk Management - Variance Minimization or Lower Tail Outcome Elimination

    DEFF Research Database (Denmark)

    Aabo, Tom

    2002-01-01

    on future cash flows (the budget), while risk managers concerned about costly lower tail outcomes will hedge (considerably) less depending on the level of uncertainty. A risk management strategy of lower tail outcome elimination is in line with theoretical recommendations in a corporate value-adding...... perspective. A cross-case study of blue-chip industrial companies partly supports the empirical use of a risk management strategy of lower tail outcome elimination but does not exclude other factors from (co-)driving the observations....

  18. Hydrology of Quirke and Panel uranium tailings basins

    International Nuclear Information System (INIS)

    King, R.M.; MacPhie, L.

    1991-11-01

    The research project described by this report provides the AECB with an independent assessment of the 'saturated tailings concept' for the decommissioning of tailing areas at the Rio Algom Quirke and Panel uranium mines near Elliot Lake in Northern Ontario. Hydrologic and hydraulic modelling for each facility showed the interrelation between the design of the water-level control facilities and the water levels in each cell for design flood and extreme low-flow conditions, taking into account all water-balance components. The estimate of seepage rates through the tailings mass is identified as a critical issue

  19. Automated classification of tailed bacteriophages according to their neck organization.

    Science.gov (United States)

    Lopes, Anne; Tavares, Paulo; Petit, Marie-Agnès; Guérois, Raphaël; Zinn-Justin, Sophie

    2014-11-27

    The genetic diversity observed among bacteriophages remains a major obstacle for the identification of homologs and the comparison of their functional modules. In the structural module, although several classes of homologous proteins contributing to the head and tail structure can be detected, proteins of the head-to-tail connection (or neck) are generally more divergent. Yet, molecular analyses of a few tailed phages belonging to different morphological classes suggested that only a limited number of structural solutions are used in order to produce a functional virion. To challenge this hypothesis and analyze proteins diversity at the virion neck, we developed a specific computational strategy to cope with sequence divergence in phage proteins. We searched for homologs of a set of proteins encoded in the structural module using a phage learning database. We show that using a combination of iterative profile-profile comparison and gene context analyses, we can identify a set of head, neck and tail proteins in most tailed bacteriophages of our database. Classification of phages based on neck protein sequences delineates 4 Types corresponding to known morphological subfamilies. Further analysis of the most abundant Type 1 yields 10 Clusters characterized by consistent sets of head, neck and tail proteins. We developed Virfam, a webserver that automatically identifies proteins of the phage head-neck-tail module and assign phages to the most closely related cluster of phages. This server was tested against 624 new phages from the NCBI database. 93% of the tailed and unclassified phages could be assigned to our head-neck-tail based categories, thus highlighting the large representativeness of the identified virion architectures. Types and Clusters delineate consistent subgroups of Caudovirales, which correlate with several virion properties. Our method and webserver have the capacity to automatically classify most tailed phages, detect their structural module, assign a

  20. An Analysis of a Heuristic Procedure to Evaluate Tail (independence

    Directory of Open Access Journals (Sweden)

    Marta Ferreira

    2014-01-01

    Full Text Available Measuring tail dependence is an important issue in many applied sciences in order to quantify the risk of simultaneous extreme events. A usual measure is given by the tail dependence coefficient. The characteristics of events behave quite differently as these become more extreme, whereas we are in the class of asymptotic dependence or in the class of asymptotic independence. The literature has emphasized the asymptotic dependent class but wrongly infers that tail dependence will result in the overestimation of extreme value dependence and consequently of the risk. In this paper we analyze this issue through simulation based on a heuristic procedure.

  1. Uranium mill tailings storage, use, and disposal problems

    International Nuclear Information System (INIS)

    Hendricks, D.W.

    1977-01-01

    Solid and liquid residues (tailings) containing substantial quantities of naturally occurring radionuclides are produced and stored at all US uranium mill sites. These radioactive wastes are a potential health hazard with the degree of hazard depending largely on the tailings management practices at the individual sites. The principal pathways of potential radiation exposure to man are discussed. A description is presented of some past and current tailings storage practices together with a description of some of the possible problems associated with various stabilization and disposal options. 16 figures

  2. Price Tails in the Smith and Farmer's Model

    Czech Academy of Sciences Publication Activity Database

    Šmíd, Martin

    2008-01-01

    Roč. 15, č. 25 (2008), s. 31-40 ISSN 1212-074X R&D Projects: GA ČR GA402/07/1113; GA ČR(CZ) GA402/06/1417 Institutional research plan: CEZ:AV0Z10750506 Keywords : limit order market * continuous double auction * price increments * fat tails * tail exponent Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2008/E/smid-price tails in the smith and farmer's model.pdf

  3. Variation in parental investment and relative clutch mass of the spiny-tail iguana, Ctenosaura pectinata (Squamata: Iguanidae in central México Variación en la inversión parental y masa relativa de la nidada en la iguana de cola espinosa Ctenosaura pectinata (Squamata: Iguanidae en el centro de México

    Directory of Open Access Journals (Sweden)

    Rubén Castro-Franco

    2011-03-01

    Full Text Available We measured the length, width, volume, and weight of 871 freshly laid eggs of 28 clutches of Ctenosaura pectinata. The iguanas were obtained from a tropical dry forest area in central Mexico. The relative clutch mass was related positively to the average egg weight but not to average egg volume. Unlike what usually occurs in lizards, where the body length strongly predicts egg production, in C. pectinata clutch size and egg size were not correlated with female weight or snout-vent length. Observed differences revealed variation in the weight-size of the egg within an individual clutch. Therefore, there is not an optimization of the egg in the studied population of Ctenosaura, as usually occurs in small lizards. This variation associated with reproduction takes place in the middle of the dry season, and may be interpreted as an adaptation to facilitate the adjustment of different phenotypes in environments with extreme drought.Medimos la longitud, amplitud, volumen, y peso de 871 huevos recién puestos de 28 nidadas de Ctenosaura pectinata. Las iguanas fueron obtenidas en un área de bosque tropical seco en el centro de México. La masa relativa de la nidada estuvo relacionada positivamente con el peso promedio de los huevos pero no con el volumen promedio del huevo. A diferencia de lo que ocurre usualmente en lagartijas, donde la longitud del cuerpo determina la producción de huevos, en C. pectinata el tamaño de la puesta y el tamaño del huevo no se correlacionan con el peso y tamaño de las hembras. Las diferencias observadas revelan variación en el tamaño y peso de los huevos dentro de las puestas individuales. En consecuencia, no hay una optimización del huevo en la población estudiada de Ctenosaura, como usualmente ocurre en lagartijas de tamaño pequeño. Esta variación asociada con la reproducción tiene lugar a mitad de la estación seca, y puede ser interpretada como una adaptación para facilitar el ajuste de diferentes

  4. Probabilistic calculation of dose commitment from uranium mill tailings

    International Nuclear Information System (INIS)

    1983-10-01

    The report discusses in a general way considerations of uncertainty in relation to probabilistic modelling. An example of a probabilistic calculation applied to the behaviour of uranium mill tailings is given

  5. Sandia's activities in uranium mill tailings remedial action

    International Nuclear Information System (INIS)

    Neuhauser, S.

    1980-01-01

    The Uranium Mill Tailings Radiation Control Act of 1978 requires that remedial action be taken at over 20 inactive uranium mill tailings sites in the United States. Standards promulgated by the EPA under this act are to be the operative standards for this activity. Proposed standards must still undergo internal review, public comment, and receive Nuclear Regulatory Commission concurrence before being finalized. Briefly reviewed, the standards deal separately with new disposal sites (Part A) and cleanup of soil and contaminated structures at existing locations (Part B). In several cases, the present sites are felt to be too close to human habitations or to be otherwise unacceptably located. These tailings will probably be relocated. New disposal sites for relocated tailings must satisfy certain standards. The salient features of these standards are summarized

  6. Practical considerations of pyrite oxidation control in uranium tailings

    International Nuclear Information System (INIS)

    1984-05-01

    The problems posed by the oxidation of pyrite in uranium tailings include the generation of sulfuric acid and acid sulfate metal salts. These have substantial negative impacts on watercourse biota by themselves, and the lowered pH levels tend to mobilize heavy metals present in the tailings the rate of oxidation of pyrite at lower pH levels is catalyzed by sulfur and iron oxidizing bacteria present in soils. No single clear solution to the problems came from this study. Exclusion of air is a most important preventative of bacterial catalysis of oxidation. Bactericides, chemically breaking the chain of integrated oxidation reactions, maintaining anaerobic conditions, or maintaining a neutral or alkaline pH all reduce the oxidation rate. Removal of pyrite by flotation will reduce but not eliminate the impact of pyrite oxidation. Controlled oxidation of the remaining sulfide in the flotation tails would provide an innocuous tailing so far as acidity generation is concerned

  7. Western Red-tailed Skink Distribution in Southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Hall, D. B. and Gergor, P. D.

    2011-11-01

    This slide show reports a study to: determine Western Red-tailed Skink (WRTS) distribution on Nevada National Security Site (NNSS); identify habitat where WRTS occur; learn more about WRTS natural history; and document distribution of other species.

  8. Recovery of 'Nsutite' from Tailings Material of Ghana Manganese ...

    African Journals Online (AJOL)

    GMC) Limited Mine, Nsuta. M Ali, RK Amankwah. Abstract. An investigation was conducted for the enrichment of manganese oxide tailings generated by a spiral concentration plant at Ghana Manganese Company (GMC) Limited, Nsuta. The work ...

  9. Biodegradation of cycloalkane carboxylic acids in oil sand tailings

    Energy Technology Data Exchange (ETDEWEB)

    Herman, D.C.; Costerton, J.W. (Calgary Univ., Dept. of Biological Sciences, AB (Canada)); Fedorak, P.M. (Alberta Univ., Dept. of Microbiology, AB (Canada))

    1993-01-01

    The biodegradation of both an n-alkane and several carboxylated cycloalkanes was examined experimentally within tailings produced by the extraction of bitumen from the Athabasca oil sands. The carboxylated cycloalkanes examined were structurally similar to naphthenic acids that have been associated with the acute toxicity of oil sand tailings. The biodegradation potential of naphthenic acids was estimated by determining the biodegradation of both the carboxylated cycloalkanes and hexadecane in oil sand tailings. Carboxylated cycloalkanes were biodegraded within oil sands tailings, although compounds with methyl substitutions on the cycloalkane ring were more resistant to microbial degradation. Microbial activity against hexadecane and certain carboxylated cycloalkanes was found to be nitrogen and phosphorus limited. 21 refs., 3 refs., 1 tab.

  10. Long-term ecological behaviour of abandoned uranium mill tailings

    International Nuclear Information System (INIS)

    Kalin, Margarete

    1984-12-01

    Semi-aquatic and terrestrial areas on abandoned or inactive uranium mill tailings in Ontario were studied in order to identify the growth characteristics of the naturally invading species dominating these areas. Semi-aquatic areas of tailings sites have been invaded by cattails. These species formed wetland communities which varied in size, but all were essentially monocultures of Typha latifolia, T. angustifolia, or of the hybrids T. glauca. Sedges, Scripus cyperinus (wool-grass) and Phragmites australis (reed-grass), were found in transition zones between the cattail stand and the dry section of the tailings site. The expansion of the cattail stands appeared to be controlled by the hydrological conditions on the site, rather than the chemical characteristics of the tailings

  11. Non-equilibrium and band tailing in organic conductors

    Indian Academy of Sciences (India)

    . Non-equilibrium due to coupling between applied energy and free electrons can be responsible for the exponential relaxation from non-equilibrium to equilibrium. Keywords. Band tailing; organic conductors; IR spectra; electrical resistivity.

  12. Mixtures of tails in clustered automobile collision claims

    NARCIS (Netherlands)

    R. Kalb (Reinhard); P. Kofman (Paul); A.C.F. Vorst (Ton)

    1996-01-01

    textabstractKnowledge of the tail shape of claim distributions provides important actuarial information. This paper discusses how two techniques commonly used in assessing the most appropriate underlying distribution can be usefully combined. The maximum likelihood approach is theoretically

  13. Relationship between tail lesions and lung health in slaughter pigs.

    Science.gov (United States)

    van Staaveren, Nienke; Vale, Ana P; Manzanilla, Edgar G; Teixeira, Dayane L; Leonard, Finola C; Hanlon, Alison; Boyle, Laura A

    2016-05-01

    Tail lesions are associated with poor health either because they serve as a point of entry for pathogens or because of shared risk factors. This study investigated the relationship between carcass tail lesion and lung lesion severity scores in slaughter pigs. Carcasses were scored after scalding/dehairing for tail lesion severity (0-4). Lungs were scored according to an adapted version of the BPEX pig health scheme. Severity of enzootic pneumonia (EP-like lesions) was recorded on a scale of 0-50. Severity of pleurisy was scored on a 0-2 scale with score 2 equating to severe pleurisy or those lungs that remained attached to the chest wall ('lungs in chest'). The database for assessing pleurisy lesions contained all pleurisy scores (n=5628). Lungs with a score of 2 for pleurisy were excluded from the analysis of all other lung lesions as such lungs could not be assessed for other lesions (n=4491). Associations between tail lesions and different lung lesion outcomes were analysed using generalized linear mixed models (PROC GLIMMIX) with random effect for batch. Males were more affected by moderate (OR=1.9, 95% CI 1.51-2.34) and severe (OR=5.8, 95% CI 3.45-9.70) tail lesions than females. EP-like lesions and pleurisy were most commonly observed. Pigs with severe tail lesions tended to have more 'lungs in chest' than pigs with moderate tail lesions (P=0.1). No other associations between tail lesions and lung lesions were found. Males had higher odds of having EP-like lesions (OR=1.2, 95% CI 1.05-1.36) than females. Tail lesions on the carcass may not be an accurate predictor of lung health. However, tail lesions are important welfare indicators and respiratory disease is a significant infectious condition affecting pigs. Thus, recording of tail and lung lesions at meat inspection provides valuable information regarding on-farm health and welfare of pigs. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Lung cancer risks in the vicinity of uranium tailings sites

    International Nuclear Information System (INIS)

    Rogers, V.C.; Sandquist, G.M.

    1982-04-01

    Lung cancer mortality data have been assembled for many counties of interest to the Uranium Mill Tailings Remedial Action Program (UMTRAP). The counties generally either contain UMTRAP tailings sites or are adjacent to them. The lung cancer rates of nearly all counties are less than the US average rate. In addition, some of the many factors associated with lung cancer are identified as are cancer risk estimators for radon daughters. 17 refs., 19 figs., 1 tab

  15. Early sonographic findings suggestive of the human fetal tail.

    Science.gov (United States)

    Zimmer, E Z; Bronshtein, M

    1996-04-01

    The prenatal diagnosis of a human tail was suggested in six fetuses with ultrasound findings of an echogenic protrusion in the lumbo-sacral region. All fetuses were at 14-16 weeks' gestation. The ultrasound findings disappeared in all cases at 22-23 weeks. Dermal abnormalities such as pilonidal sinus, deep dimples, and scarred tissue were found in all six newborns. It is possible that the late regression of the embryonic human tail was the cause of these dermal findings.

  16. Controlled DNA compaction within chromatin: the tail-bridging effect

    OpenAIRE

    Muehlbacher, Frank; Holm, Christian; Schiessel, Helmut

    2005-01-01

    We study the mechanism underlying the attraction between nucleosomes, the fundamental packaging units of DNA inside the chromatin complex. We introduce a simple model of the nucleosome, the eight-tail colloid, consisting of a charged sphere with eight oppositely charged, flexible, grafted chains that represent the terminal histone tails. We demonstrate that our complexes are attracted via the formation of chain bridges and that this attraction can be tuned by changing the fraction of charged ...

  17. Engineering, environmental and economic planning for tailings disposal

    International Nuclear Information System (INIS)

    Poellot, J.H.

    1982-01-01

    There are two principal points made in this paper. First, mining waste materials, or tailings, are geotechnical materials. Their behavior follows the principles of soil mechanics and is predictable by these principles. Second, proper disposal, meaning safe, environmentally sound and economical disposal, requires planning and recognizing waste disposal as part of the total mining system and process. In the development of these two principles, planning, design, and economic considerations of mine tailings are discussed

  18. Testing tail-mounted transmitters with Myocastor coypus (nutria)

    Science.gov (United States)

    Merino, S.; Carter, J.; Thibodeaux, G.

    2007-01-01

    We developed a tail-mounted radio-transmitter for Myocastor coypus (nutria) that offers a practical and efficient alternative to collar or implant methods. The mean retention time was 96 d (range 57-147 d, n = 7), making this a practical method for short-term studies. The tail-mounts were less injurious to animals than collars and easier for field researchers to implement than either collars or surgically implanted transmitters.

  19. Tail Biting Trellis Representation of Codes: Decoding and Construction

    Science.gov (United States)

    Shao. Rose Y.; Lin, Shu; Fossorier, Marc

    1999-01-01

    This paper presents two new iterative algorithms for decoding linear codes based on their tail biting trellises, one is unidirectional and the other is bidirectional. Both algorithms are computationally efficient and achieves virtually optimum error performance with a small number of decoding iterations. They outperform all the previous suboptimal decoding algorithms. The bidirectional algorithm also reduces decoding delay. Also presented in the paper is a method for constructing tail biting trellises for linear block codes.

  20. User-Friendly Tail Bounds for Matrix Martingales

    Science.gov (United States)

    2011-01-16

    USER-FRIENDLY TAIL BOUNDS FOR MATRIX MARTINGALES JOEL A. TROPP ! Report Documentation Page Form ApprovedOMB No. 0704-0188...00-2011 4. TITLE AND SUBTITLE User-Friendly Tail Bounds for Matrix Martingales 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...BOUNDS FOR MATRIX MARTINGALES JOEL A. TROPP Abstract. This report presents probability inequalities for sums of adapted sequences of random, self

  1. Fitting Heavy Tailed Distributions: The poweRlaw Package

    Directory of Open Access Journals (Sweden)

    Colin S. Gillespie

    2015-03-01

    Full Text Available Over the last few years, the power law distribution has been used as the data generating mechanism in many disparate fields. However, at times the techniques used to fit the power law distribution have been inappropriate. This paper describes the poweRlaw R package, which makes fitting power laws and other heavy-tailed distributions straightforward. This package contains R functions for fitting, comparing and visualizing heavy tailed distributions. Overall, it provides a principled approach to power law fitting.

  2. Preparation of polymeric aluminium ferric chloride from bauxite tailings

    Directory of Open Access Journals (Sweden)

    Ma D.

    2013-01-01

    Full Text Available Bauxite tailings are the main solid wastes in the ore dressing process. The Al2O3 and Fe2O3 contents in bauxite tailings can reach 50% and 13% respectively. The present study proposed a feasible method to use bauxite tailings to prepare polymeric aluminium ferric chloride (PAFC, a new composite inorganic polymer for water purification. Bauxite tailings roasted reacting with hydrochloric acid under air, pickle liquor which mainly contains Fe3+, Al3+ was generated, then calcium aluminate was used to adjust pH value and the basicity of the pickle liquor, the PAFC was subsequently prepared after the polymerization process. The optimal synthesizing parameters for the preparation of PAFC obtained were as follows: the concentration of hydrochloric acid of 24 wt%, ratio of hydrochloric acid to bauxite tailings of 6:1, temperature of 90ºC, leaching time of 2.5 hours, ration of pickle liquor to calcium aluminate of 12:1, polymerization temperature of 90ºC and polymerization time of about 3 hours. The basicity of PAFC was higher than 68%, the sum concentration of Al2O3 and Fe2O3 was beyond 12.5%. The results of flocculation tests indicate that the PAFC has a better performance of removing the turbidity of wastewater compared to PAC, and PAFC prepared by bauxite tailings is a kind of high quality flocculants.

  3. Long-term stabilization of uranium mill tailings

    Energy Technology Data Exchange (ETDEWEB)

    Voorhees, L.D.; Sale, M.J.; Webb, J.W.; Mulholland, P.J.

    1983-01-01

    The primary hazard associated with uranium mill tailings is exposure to a radioactive gas, radon-222, the concentration of which has been correlated with the occurrence of lung cancer. Previous studies on radon attenuation conclude that the placement of earthen cover materials over the tailings is the most effective technique for reducing radioactive emissions and dispersal of tailings. The success of such a plan, however, is dependent on ensuring the long-term integrity of these cover materials. Soil erosion from water and wind is the major natural cause of destabilizing earthen cover materials. Field data related to the control of soil loss are limited and only indirectly apply to the problem of isolation of uranium mill tailings over very long time periods (up to 80,000 a). However, sufficient information is available to determine benefits that will result from the changes in specific design variables and to evaluate the need for different design strategies among potential disposal sites. The three major options available for stabilization of uranium mill tailings are: rock cover, soil and revegetation, or a combination of both on different portions of the tailings cover. The optimal choice among these alternatives depends on site-specific characteristics such as climate and local geomorphology and soils, and on design variables such as embankment, heights and slopes, modification of upstream drainage, and revegetation practices. Generally, geomorphic evidence suggests that use of soil and vegetation alone will not be adequate to reduce erosion on slopes greater than about 5 to 9%.

  4. Long-term stabilization of uranium mill tailings

    International Nuclear Information System (INIS)

    Voorhees, L.D.; Sale, M.J.; Webb, J.W.; Mulholland, P.J.

    1983-01-01

    The primary hazard associated with uranium mill tailings is exposure to a radioactive gas, radon-222, the concentration of which has been correlated with the occurrence of lung cancer. Previous studies on radon attenuation conclude that the placement of earthen cover materials over the tailings is the most effective technique for reducing radioactive emissions and dispersal of tailings. The success of such a plan, however, is dependent on ensuring the long-term integrity of these cover materials. Soil erosion from water and wind is the major natural cause of destabilizing earthen cover materials. Field data related to the control of soil loss are limited and only indirectly apply to the problem of isolation of uranium mill tailings over very long time periods (up to 80,000 a). However, sufficient information is available to determine benefits that will result from the changes in specific design variables and to evaluate the need for different design strategies among potential disposal sites. The three major options available for stabilization of uranium mill tailings are: rock cover, soil and revegetation, or a combination of both on different portions of the tailings cover. The optimal choice among these alternatives depends on site-specific characteristics such as climate and local geomorphology and soils, and on design variables such as embankment, heights and slopes, modification of upstream drainage, and revegetation practices. Generally, geomorphic evidence suggests that use of soil and vegetation alone will not be adequate to reduce erosion on slopes greater than about 5 to 9%

  5. Measurement and calculation of radon releases from uranium mill tailings

    International Nuclear Information System (INIS)

    1992-01-01

    The mining and milling of uranium ores produces large quantities of radioactive wastes. Although relatively small in magnitude compared to tailings from metal mining and extraction processes, the present worldwide production of such tailings exceeds 20 million tonnes annually. There is thus a need to ensure that the environmental and health risks from these materials are reduced to an acceptable level. This report has been written as a complement to another publication entitled Current Practices for the Management and Confinement of Uranium Mill Tailings, IAEA Technical Reports Series No. 335, which provides a general overview of all the important factors in the siting, design and construction of tailings impoundments, and in the overall management of tailings with due consideration give to questions of the release of pollutants from tailings piles. The present report provides a comprehensive overview of the release, control and monitoring of radon, including computational methods. The report was first drafted in 1989 and was then reviewed at an Advisory Group meeting in 1990. 42 refs, 9 figs, 3 tabs

  6. Leachability of radioactive constituents from uranium mine tailings

    International Nuclear Information System (INIS)

    Bryant, D.N.; Cohen, D.B.; Durham, R.W.

    1979-04-01

    A project was carried out using lysimeters to determine the leaching of radioactive constituents and BaRaSO 4 from abandoned uranium mine tailings. Lime addition to the surface of acidic abandoned tailings did not reduce the level of radioactive constituents in the leachate. Considerable increases in levels of the radionuclides 230 Th, 232 Th and 22 /8Th, as well as gross alpha and beta activity in the leachate, occurred five months after recycling of BaRaSO 4 sediments to the surface layers of abandoned tailings. After nine months of leaching, the levels of 226 Ra in the leachate were 30% greater than the tailings plus sediment treatment than from tailings only (control). Another experiment compared the quality of effluent flowing over chemically-fixed (solidified) BaRaSO 4 sediments with that of non-fixed (control) in simulated sedimentation ponds. During seven months the release of 226 Ra to water from chemically-fixed BaRaSO 4 sediments remained 3 for phosphorus removal) was applied to supply 3 percent organic matter in the top 15 cm of the revegetated lysimeters. Undiluted effluent and leachate from chemically-fixed BaRaSO 4 sediments and fresh tailings were 100 percent lethal to Daphnia pulex and rainbow trout (Salmo gairdneri) in static 96-hour bioassay tests. Diluted (50 percent) effluent samples were non-toxic. (auth)

  7. Current practices and options for confinement of uranium mill tailings

    International Nuclear Information System (INIS)

    1981-01-01

    At the United Nations Conference on the Human Environment, which took place in Stockholm from 4 to 6 June 1972, national governments were asked to explore, with the International Atomic Energy Agency and other appropriate international organizations, international co-operation on radioactive waste matters including those of mining and tailings disposal. Since that time the IAEA has been active in the field of uranium and thorium mill tailings management. As part of this activity, the present report describes current practices and options for confinement of uranium mill tailings. It is addressed to technical and administrative personnel who are involved in planning and implementing national and industrial programmes on the management of such tailings. In 1974 and 1975 the IAEA convened meetings of experts to review matters of interest and importance in the management of uranium and thorium mine and mill tailings. These activities led to the publication in 1976 of Management of Wastes from the Mining and Milling of Uranium and Thorium Ores, a Code of Practice and Guide to the Code, IAEA Safety Series No. 44. As a continuation of this activity, the IAEA is here dealing more specifically with the design and siting considerations for the management of uranium mill tailings

  8. Formation of dwarf galaxies in tidal tails

    Science.gov (United States)

    Barnes, Joshua E.; Hernquist, Lars

    1992-01-01

    The results are reported of numerical simulations of encounters between disk galaxies, each modeled with a central bulge, an exponential disk, and a spheroidal dark-matter halo. It is found that dwarf systems form in material drawn out during the encounter; these objects can capture large amounts of moderately enriched gas but retain little dark matter from their parents' haloes. They should therefore have lower mass-to-light ratios than galaxies formed directly by the collapse of primordial matter.

  9. Evolution of Geochemical and Mineralogical Parameters during In Situ Remediation of a Marine Shore Tailings Deposit by the Implementation of a Wetland Cover

    OpenAIRE

    Diaby, Nouhou; Dold, Bernhard

    2014-01-01

    We present data of the time-evolution of a remediation approach on a marine shore tailings deposit by the implementation of an artificial wetland. Two remediation cells were constructed: one in the northern area at sea-level and one in the central delta area (above sea-level) of the tailings. At the beginning, the “sea-level” remediation cell had a low pH (3.1), with high concentrations of dissolved metals and sulfate and chloride ions and showed sandy grain size. After wetland implementation...

  10. Suspended electrodialytic extraction of toxic elements for detoxification of three different mine tailings

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Ottosen, Lisbeth M.; Hansen, H.K.

    2016-01-01

    have shown that electrokinetic treatment can remove Cd, Cu, Pb, and Zn from tailings soils; As from tailings; and Cu from tailings. Still, however, a major concern is the long treatment-time required for the element-transport through the tailings matrix. Therefore several enhancement methods have been...

  11. Analysis of the histone protein tail and DNA in nucleosome using molecular dynamics simulation

    Science.gov (United States)

    Fujimori, R.; Komatsu, Y.; Fukuda, M.; Miyakawa, T.; Morikawa, R.; Takasu, M.

    2013-02-01

    We study the effect of the tails of H3 and H4 histones in the nucleosomes, where DNA and histones are packed in the form of chromatin. We perform molecular dynamics simulations of the complex of DNA and histones and calculate the mean square displacement and the gyration radius of the complex of DNA and histones for the cases with tails intact and the cases with tails missing. Our results show that the H3 tails are important for the motion of the histones. We also find that the motion of one tail is affected by other tails, although the tails are distanced apart, suggesting the correlated motion in biological systems.

  12. Is rhizosphere remediation sufficient for sustainable revegetation of mine tailings?

    Science.gov (United States)

    Huang, Longbin; Baumgartl, Thomas; Mulligan, David

    2012-07-01

    Revegetation of mine tailings (fine-grained waste material) starts with the reconstruction of root zones, consisting of a rhizosphere horizon (mostly topsoil and/or amended tailings) and the support horizon beneath (i.e. equivalent to subsoil - mostly tailings), which must be physically and hydro-geochemically stable. This review aims to discuss key processes involved in the development of functional root zones within the context of direct revegetation of tailings and introduces a conceptual process of rehabilitating structure and function in the root zones based on a state transition model. Field studies on the revegetation of tailings (from processing base metal ore and bauxite residues) are reviewed. Particular focus is given to tailings' properties that limit remediation effectiveness. Aspects of root zone reconstruction and vegetation responses are also discussed. When reconstructing a root zone system, it is critical to restore physical structure and hydraulic functions across the whole root zone system. Only effective and holistically restored systems can control hydro-geochemical mobility of acutely and chronically toxic factors from the underlying horizon and maintain hydro-geochemical stability in the rhizosphere. Thereafter, soil biological capacity and ecological linkages (i.e. carbon and nutrient cycling) may be rehabilitated to integrate the root zones with revegetated plant communities into sustainable plant ecosystems. A conceptual framework of system transitions between the critical states of root zone development has been proposed. This will illustrate the rehabilitation process in root zone reconstruction and development for direct revegetation with sustainable plant communities. Sustainable phytostabilization of tailings requires the systematic consideration of hydro-geochemical interactions between the rhizosphere and the underlying supporting horizon. It further requires effective remediation strategies to develop hydro-geochemically stable

  13. Tail Docking and Ear Cropping Dogs: Public Awareness and Perceptions.

    Science.gov (United States)

    Mills, Katelyn E; Robbins, Jesse; von Keyserlingk, Marina A G

    2016-01-01

    Tail docking and ear cropping are two surgical procedures commonly performed on many dog breeds. These procedures are classified as medically unnecessary surgeries whose purpose is primarily cosmetic. Available attitude research surrounding these controversial practices has been limited to surveys of veterinarians and dog breeders familiar with both practices. The aim of this project was to: 1) assess public awareness of tail docking and ear cropping, 2) determine whether physical alteration of a dog affects how the dog, and 3) owner are perceived. In Experiment 1 awareness was measured using a combination of both explicit and implicit measures. We found that 42% of participants (n = 810) were unable to correctly explain the reason why tail docked and ear cropped dogs had short ears and tails. Similarly, an implicit measure of awareness ('nature vs nurture task'), found that the majority of participants believed short tails and erect ears were a consequence of genetics rather than something the owner or breeder had done. The results obtained in Experiment 2 (n = 392) provide evidence that ear cropped and tail docked dogs are perceived differently than an identical dog in its 'natural' state. Modified dogs were perceived as being more aggressive, more dominant, less playful and less attractive than natural dogs. Experiment 3 (n = 410) is the first evidence that owners of modified dogs are perceived as being more aggressive, more narcissistic, less playful, less talkative and less warm compared to owners of natural dogs. Taken together, these results suggest that although a significant proportion of subjects appear unaware of the practices of tail docking and ear cropping in dogs, these procedures have significant impacts on how modified dogs and their owners are perceived by others.

  14. Tail Docking and Ear Cropping Dogs: Public Awareness and Perceptions.

    Directory of Open Access Journals (Sweden)

    Katelyn E Mills

    Full Text Available Tail docking and ear cropping are two surgical procedures commonly performed on many dog breeds. These procedures are classified as medically unnecessary surgeries whose purpose is primarily cosmetic. Available attitude research surrounding these controversial practices has been limited to surveys of veterinarians and dog breeders familiar with both practices. The aim of this project was to: 1 assess public awareness of tail docking and ear cropping, 2 determine whether physical alteration of a dog affects how the dog, and 3 owner are perceived. In Experiment 1 awareness was measured using a combination of both explicit and implicit measures. We found that 42% of participants (n = 810 were unable to correctly explain the reason why tail docked and ear cropped dogs had short ears and tails. Similarly, an implicit measure of awareness ('nature vs nurture task', found that the majority of participants believed short tails and erect ears were a consequence of genetics rather than something the owner or breeder had done. The results obtained in Experiment 2 (n = 392 provide evidence that ear cropped and tail docked dogs are perceived differently than an identical dog in its 'natural' state. Modified dogs were perceived as being more aggressive, more dominant, less playful and less attractive than natural dogs. Experiment 3 (n = 410 is the first evidence that owners of modified dogs are perceived as being more aggressive, more narcissistic, less playful, less talkative and less warm compared to owners of natural dogs. Taken together, these results suggest that although a significant proportion of subjects appear unaware of the practices of tail docking and ear cropping in dogs, these procedures have significant impacts on how modified dogs and their owners are perceived by others.

  15. Black-tailed and white-tailed jackrabbits in the American West: History, ecology, ecological significance, and survey methods

    Science.gov (United States)

    Simes, Matthew; Longshore, Kathleen M.; Nussear, Kenneth E.; Beatty, Greg L.; Brown, David E.; Esque, Todd C.

    2015-01-01

    Across the western United States, Leporidae are the most important prey item in the diet of Golden Eagles (Aquila chrysaetos). Leporids inhabiting the western United States include black-tailed (Lepus californicus) and white-tailed jackrabbits (Lepus townsendii) and various species of cottontail rabbit (Sylvilagus spp.). Jackrabbits (Lepus spp.) are particularly important components of the ecological and economic landscape of western North America because their abundance influences the reproductive success and population trends of predators such as coyotes (Canis latrans), bobcats (Lynx rufus), and a number of raptor species. Here, we review literature pertaining to black-tailed and white-tailed jackrabbits comprising over 170 published journal articles, notes, technical reports, conference proceedings, academic theses and dissertations, and other sources dating from the late 19th century to the present. Our goal is to present information to assist those in research and management, particularly with regard to protected raptor species (e.g., Golden Eagles), mammalian predators, and ecological monitoring. We classified literature sources as (1) general information on jackrabbit species, (2) black-tailed or (3) white-tailed jackrabbit ecology and natural history, or (4) survey methods. These categories, especially 2, 3, and 4, were further subdivided as appropriate. The review also produced several tables on population trends, food habits, densities within various habitats, and jackrabbit growth and development. Black-tailed and white-tailed jackrabbits are ecologically similar in general behaviors, use of forms, parasites, and food habits, and they are prey to similar predators; but they differ in their preferred habitats. While the black-tailed jackrabbit inhabits agricultural land, deserts, and shrublands, the white-tailed jackrabbit is associated with prairies, alpine tundra, and sagebrush-steppe. Frequently considered abundant, jackrabbit numbers in western North

  16. Remediation of the Sillamae Radioactive Tailings Pond, Estonia

    International Nuclear Information System (INIS)

    Barnekow, U.; Jaaksoo, R.; Kaasik, T.

    2011-01-01

    The paper presents experiences gained and progress achieved during the ongoing Sillamaee Radioactive Tailings Pond Remediation Project. The Sillamaee tailings pond covering ca. 50 ha is located next to the shoreline of the Baltic Sea near Sillamaee town in Estonia. Tailings disposal included mill tailings from uranium ore processing (1953-1977), enriched uranium refining (1977- 1990), from rare earth elements processing (since 1970; tailings disposal ended 2003), black shale processing (1948-1953) and liquid oil-shale ashes from the local power plant. Initial environmental and geotechnical investigations identified insufficient safety of the tailings pond for radiological, environmental and geotechnical reasons. Contaminated seepage was entering the Baltic Sea. The 25 m high northern tailings dam was affected by marine erosion and the stability of the dam was found to be insufficient. Therefore the multi-national Sillamaee Radioactive Tailings Pond Remediation Programme was launched in 1998 jointly financed by North European Countries (NEFCO), EU and Estonia. The remediation project included the following crucial remediation steps: Drillings and samplings including geotechnical, (hydro-)geological and environmental investigations (2000-2001); relocation of mine wastes and contaminated soils from the surrounding area onto the tailings pond for interim covering (2000-2003); initial stabilization measures (2001-2003) including a 1080 m long shore protection embankment along the shoreline of the Baltic Sea, a 720 m long pile grillage for stabilizing the northern dam including two rows of 15 m or 18 m deep continuous flight auger piles, a 580 m long and 12-18 m deep cut-off wall, a deep gravel-filled drainage ditch (520 m, up to 12 m deep) and a deep drainage trench. Reshaping of the dams with respect to long term dam stability and contouring of the pond area with respect to long term settlement portions lasted from 2003 till 2004 building up a ridge-type surface

  17. Long-Term Performance of Uranium Tailings Disposal Cells - 13340

    International Nuclear Information System (INIS)

    Bostick, Kent; Daniel, Anamary; Pill, Ken; Tachiev, Georgio; Noosai, Nantaporn; Villamizar, Viviana

    2013-01-01

    Recently, there has been interest in the performance and evolution of Uranium Mill Tailings Remedial Action (UMTRA) Project disposal cell covers because some sites are not compliant with groundwater standards. Field observations of UMTRA disposal cells indicate that rock covers tend to become vegetated and that saturated conductivities in the upper portion of radon barriers may increase due to freeze/thaw cycles and biointrusion. This paper describes the results of modeling that addresses whether these potential changes and transient drainage of moisture in the tailings affect overall performance of the disposal cells. A numerical unsaturated/saturated 3-dimensional flow model was used to simulate whether increases in saturated conductivities in radon barriers with rock covers affect the overall performance of the disposal cells using field data from the Shiprock, NM, UMTRA site. A unique modeling approach allowed simulation with daily climatic conditions to determine changes in moisture and moisture flux from the disposal cell. Modeling results indicated that increases in the saturated conductivity at the top of radon barrier do not influence flux from the tailings with time because the tailings behave similar hydraulically to the radon barrier. The presence of a thin layer of low conductivity material anywhere in the cover or tailings restricts flux in the worst case to the saturated conductivity of that material. Where materials are unsaturated at depth within the radon barrier of tailings slimes, conductivities are typically less than 10 -8 centimeters per second. If the low conductivity layer is deep within the disposal cell, its saturated properties are less likely to change with time. The significance of this modeling is that operation and maintenance of the disposal cells can be minimized if they are allowed to progress to a natural condition with some vegetation and soil genesis. Because the covers and underlying tailings have a very low saturated

  18. Reactivity of the isolated perfused rat tail vascular bed

    Directory of Open Access Journals (Sweden)

    A.S. França

    1997-07-01

    Full Text Available Isolated segments of the perfused rat tail artery display a high basal tone when compared to other isolated arteries such as the mesenteric and are suitable for the assay of vasopressor agents. However, the perfusion of this artery in the entire tail has not yet been used for functional studies. The main purpose of the present study was to identify some aspects of the vascular reactivity of the rat tail vascular bed and validate this method to measure vascular reactivity. The tail severed from the body was perfused with Krebs solution containing different Ca2+ concentrations at different flow rates. Rats were anesthetized with sodium pentobarbital (65 mg/kg and heparinized (500 U. The tail artery was dissected near the tail insertion, cannulated and perfused with Krebs solution plus 30 µM EDTA at 36oC and 2.5 ml/min and the procedures were started after equilibration of the perfusion pressure. In the first group a dose-response curve to phenylephrine (PE (0.5, 1, 2 and 5 µg, bolus injection was obtained at different flow rates (1.5, 2.5 and 3.5 ml/min. The mean perfusion pressure increased with flow as well as PE vasopressor responses. In a second group the flow was changed (1.5, 2, 2.5, 3 and 3.5 ml/min at different Ca2+ concentrations (0.62, 1.25, 2.5 and 3.75 mM in the Krebs solution. Increasing Ca2+ concentrations did not alter the flow-pressure relationship. In the third group a similar protocol was performed but the rat tail vascular bed was perfused with Krebs solution containing PE (0.1 µg/ml. There was an enhancement of the effect of PE with increasing external Ca2+ and flow. PE vasopressor responses increased after endothelial damage with air and CHAPS, suggesting an endothelial modulation of the tone of the rat tail vascular bed. These experiments validate the perfusion of the rat tail vascular bed as a method to investigate vascular reactivity

  19. Use of cemented paste backfill in arsenic-rich tailings

    Science.gov (United States)

    Hamberg, Roger; Maurice, Christian; Alakangas, Lena

    2015-04-01

    Gold is extracted by cyanide leaching from inclusions in arsenopyrite from a mine in the north of Sweden. The major ore mineral assemblage consists of pyrrhotite and arsenopyrite-loellingite. Effluents from the gold extraction were treated with Fe2(SO4)3, with the aim to form stable As-bearing Fe-precipitates (FEP). The use of the method called cemented paste backfill (CPB) is sometimes suggested for the management of tailings. In CPB, tailings are commonly mixed with low proportions (3 - 7 %) of cement and backfilled into underground excavated area. To reduce costs, amendments such as granulated blast furnace slag (GBFS), biofuel fly ash (BFA) and cement kiln dust (CKD) are used for partial replacement of cement in CPB due to their pozzolanic and alkaline properties. The objective for this study was to evaluate the leaching behaviour of As in CPB-mixtures with low proportions (1 - 3 %) of BFA and ordinary cement and unmodified tailings. The selection of CPB-recipies was made based on technical and economical criterias to adress the demands deriving from the mining operations. Speciation of the As in ore and tailings samples revealed that mining processes have dissolved the majority of the arsenopyrite in the ore, causing secondary As phases to co-precipitate with newly formed FEP:s. Tank leaching tests (TLT) and weathering cells (WCT) were used to compare leaching behaviour in a monolithic mass contra a crushed material. Quantification of the presumed benefit of CPB was made by calculation of the cumulative leaching of As. Results from the leaching tests (TLT and WCT) showed that the inclusion of As-rich tailings into a cementitious matrix increased leaching of As. This behaviour could partially be explained by an increase of pH. The addition of alkaline binder materials to tailings increased As leaching due to the relocation of desorbed As from FEPs into less acid-tolerant species such as Ca-arsenates and cementitious As-phases. Unmodified tailings generated an

  20. Green remediation of tailings from the mine using inorganic agents

    Directory of Open Access Journals (Sweden)

    Došić Aleksandar D.

    2017-01-01

    Full Text Available Increasing amounts of residues and waste materials coming from industrial activities in different processes have become an increasingly urgent problem for the future. The paper presents the problem of mine tailings generated in mine “Sase” (Republic of Srpska, Bosnia and Herzegovina with high metal content (Pb, Cu and Zn. Dumpsite of this tailing represents potential risk for water bodies in the vicinity of this location. Chosen treatment process was stabilization/solidification (S/S. Inorganic agents used in this study were fly ash and red mud that represent secondary industrial waste generated on locations relatively near the mine. Therefore, their application can be used as an example of a sustainable solution of regional environmental problem. Further investigations are related to the impact of various factors on metals leaching from mine tailings solidified/stabilized material using the above mentioned immobilization agents. The performance of the immobilizing procedures was examined using several leaching tests: ANS 16.1, TCLP, DIN, MWLP. The results indicated that all S/S samples can be considered as non-hazardous waste, as all leached metal concentrations met the set criteria. These results will further enable the modelling of metals behaviour during long-term leaching from treated mine tailing. The data are invaluable in terms of economically and environmentally sound management of mine tailing.

  1. Tail dependence and information flow: Evidence from international equity markets

    Science.gov (United States)

    Al Rahahleh, Naseem; Bhatti, M. Ishaq; Adeinat, Iman

    2017-05-01

    Bhatti and Nguyen (2012) used the copula approach to measure the tail dependence between a number of international markets. They observed that some country pairs exhibit only left-tail dependence whereas others show only right-tail. However, the flow of information from uni-dimensional (one-tail) to bi-dimensional (two-tails) between various markets was not accounted for. In this study, we address the flow of information of this nature by using the dynamic conditional correlation (DCC-GARCH) model. More specifically, we use various versions of the DCC models to explain the nexus between the information flow of international equity and to explain the stochastic forward vs. backward dynamics of financial markets based on data for a 15-year period comprising 3,782 observations. We observed that the information flow between the US and Hong Kong markets and between the US and Australian markets are bi-directional. We also observed that the DCC model captures a wider co-movement structure and inter-connectedness compared to the symmetric Joe-Clayton copula.

  2. A review on in situ phytoremediation of mine tailings.

    Science.gov (United States)

    Wang, Li; Ji, Bin; Hu, Yuehua; Liu, Runqing; Sun, Wei

    2017-10-01

    Mine tailings are detrimental to natural plant growth due to their physicochemical characteristics, such as high pH, high salinity, low water retention capacity, high heavy metal concentrations, and deficiencies in soil organic matter and fertility. Thus, the remediation of mine tailings has become a key issue in environmental science and engineering. Phytoremediation, an in situ cost-effective technology, is emerging as the most promising remediation method for mine tailings by introducing tolerant plant species. It is particularly effective in dealing with large-area mine tailings with shallow contamination of organic, nutrient and metal pollutants. In this review, the background, concepts and applications of phytoremediation are comprehensively discussed. Furthermore, proper amendments used to improve the physical, chemical and biological properties of mine tailings are systematically reviewed and compared. Emphasis is placed on the types and characteristics of tolerant plants and their role in phytoremediation. Moreover, the role of microorganisms and their mechanism in phytoremediation are also discussed in-depth. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Characterization of Emergent Data Networks Among Long-Tail Data

    Science.gov (United States)

    Elag, Mostafa; Kumar, Praveen; Hedstrom, Margaret; Myers, James; Plale, Beth; Marini, Luigi; McDonald, Robert

    2014-05-01

    Data curation underpins data-driven scientific advancements. It manages the information flux across multiple users throughout data life cycle as well as increases data sustainability and reusability. The exponential growth in data production spanning across the Earth Science involving individual and small research groups, which is termed as log-tail data, increases the data-knowledge latency among related domains. It has become clear that an advanced framework-agnostic metadata and ontologies for long-tail data is required to increase their visibility to each other, and provide concise and meaningful descriptions that reveal their connectivity. Despite the advancement that has been achieved by various sophisticated data management models in different Earth Science disciplines, it is not always straightforward to derive relationships among long-tail data. Semantic data clustering algorithms and pre-defined logic rules that are oriented toward prediction of possible data relationships, is one method to address these challenges. Our work advances the connectivity of related long-tail data by introducing the design for an ontology-based knowledge management system. In this work, we present the system architecture, its components, and illustrate how it can be used to scrutinize the connectivity among datasets. To demonstrate the capabilities of this "data network" prototype, we implemented this approach within the Sustainable Environment Actionable Data (SEAD) environment, an open-source semantic content repository that provides a RDF database for long-tail data, and show how emergent relationships among datasets can be identified.

  4. Regeneration of neural crest derivatives in the Xenopus tadpole tail

    Directory of Open Access Journals (Sweden)

    Slack Jonathan MW

    2007-05-01

    Full Text Available Abstract Background After amputation of the Xenopus tadpole tail, a functionally competent new tail is regenerated. It contains spinal cord, notochord and muscle, each of which has previously been shown to derive from the corresponding tissue in the stump. The regeneration of the neural crest derivatives has not previously been examined and is described in this paper. Results Labelling of the spinal cord by electroporation, or by orthotopic grafting of transgenic tissue expressing GFP, shows that no cells emigrate from the spinal cord in the course of regeneration. There is very limited regeneration of the spinal ganglia, but new neurons as well as fibre tracts do appear in the regenerated spinal cord and the regenerated tail also contains abundant peripheral innervation. The regenerated tail contains a normal density of melanophores. Cell labelling experiments show that melanophores do not arise from the spinal cord during regeneration, nor from the mesenchymal tissues of the skin, but they do arise by activation and proliferation of pre-existing melanophore precursors. If tails are prepared lacking melanophores, then the regenerates also lack them. Conclusion On regeneration there is no induction of a new neural crest similar to that seen in embryonic development. However there is some regeneration of neural crest derivatives. Abundant melanophores are regenerated from unpigmented precursors, and, although spinal ganglia are not regenerated, sufficient sensory systems are produced to enable essential functions to continue.

  5. Intraspecific competition, not predation, drives lizard tail loss on islands.

    Science.gov (United States)

    Itescu, Yuval; Schwarz, Rachel; Meiri, Shai; Pafilis, Panayiotis

    2017-01-01

    Tail autotomy is mainly considered an antipredator mechanism. Theory suggests that predation pressure relaxes on islands, subsequently reducing autotomy rates. Intraspecific aggression, which may also cause tail loss, probably intensifies on islands due to the higher abundance. We studied whether tail autotomy is mostly affected by predation pressure or by intraspecific competition. We further studied whether predator abundance or predator richness is more important in this context. To test our predictions, we examined multiple populations of two gecko species: Kotschy's gecko (Mediodactylus kotschyi; mainland and 41 islands) and the Mediterranean house gecko (Hemidactylus turcicus; mainland and 17 islands), and estimated their abundance together with five indices of predation. In both species, autotomy rates are higher on islands and decline with most predation indices, in contrast with common wisdom, and increase with gecko abundance. In M. kotschyi, tail-loss rates are higher on predator and viper-free islands, but increase with viper abundance. We suggest that autotomy is not simply, or maybe even mainly, an antipredatory mechanism. Rather, such defence mechanisms are a response to complex direct and indirect biotic interactions and perhaps, in the case of tail autotomy in insular populations, chiefly to intraspecific aggression. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

  6. Liner evaluation for uranium mill tailings. Final report

    International Nuclear Information System (INIS)

    Buelt, J.L.

    1983-09-01

    The Liner Evaluation for Uranium Mill Tailings Program was conducted to evaluate the need for and performance of prospective lining materials for the long-term management of inactive uranium mill tailings piles. On the basis of program results, two materials have been identified: natural foundation soil amended with 10% sodium bentonite; catalytic airblown asphalt membrane. The study showed that, for most situations, calcareous soils typical of Western US sites adequately buffer tailings leachates and prevent groundwater contamination without additional liner materials or amendments. Although mathematical modeling of disposal sites is recommended on a site-specific basis, there appears to be no reason to expect significant infiltration through the cover for most Western sites. The major water source through the tailings would be groundwater movement at sites with shallow groundwater tables. Even so column leaching studies showed that contaminant source terms were reduced to near maximum contaminant levels (MCL's) for drinking water within one or two pore volumes; thus, a limited source term for groundwater contamination exists. At sites where significant groundwater movement or infiltration is expected and the tailings leachates are alkaline, however, the sodium bentonite or asphalt membrane may be necessary

  7. Denitrification in groundwater at uranium mill tailings sites

    International Nuclear Information System (INIS)

    Goering, Timothy J.; Groffman, Armando; Thomson, Bruce

    1992-01-01

    Nitrates are a major contaminant in groundwater at many Uranium Mill Tailings Remedial Action (UMTRA) sites. Microbial denitrification, the transformation of nitrate to nitrogen gas, may be occurring in groundwater at several UMTRA sites. Denitrification is a biologically mediated process whereby facultative anaerobes use nitrate for respiration under anaerobic conditions. Denitrifying bacteria are ubiquitous in soils, sediments, and water. Denitrification requires nitrate, organic carbon, oxygen-limiting conditions, and trace nutrients, especially phosphorus. The lack of organic carbon is the most common limiting factor for denitrification. Denitrification occurs under a limited range of temperature and pH. The uranium milling processes used at UMTRA sites provided a readily available source of carbon and nitrates for denitrifying bacteria. At the Maybell, Colorado, site, the denitrifying organisms Pseudomonas, Flavobacterium and Acinetobacter were identified in core samples of materials from beneath the tailings. In addition, microcosm experiments simulating aquifer conditions beneath the tailings pile showed an average 40 percent decrease in nitrate concentrations over 13 days. At the New Rifle, Colorado, site, aquifer conditions appear favorable for denitrification. Nitrate and organic carbon are readily available in the groundwater, and redox conditions beneath and downgradient of the tailings pile are relatively anoxic. Downgradient from the tailings, total nitrogen is being removed from the groundwater system at a greater rate than the geochemically conservative anion, chloride. This removal may be due to denitrification and adsorption of ammonium onto clay and silt particles. (author)

  8. Green mines, green energy : generating green energy on tailings

    Energy Technology Data Exchange (ETDEWEB)

    Tisch, B. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Mining and Mineral Sciences Laboratories

    2008-04-01

    This article described a pilot program conducted to remediate tailings impoundment areas with organic wastes in order to yield agricultural lands for energy crops and biofuels production. The project was developed by Natural Resources Canada as a consortium of industry and research stakeholders. Further initiatives may include the establishment of wetlands areas to act as passive treatment systems. The rehabilitation of mine tailings offers significant opportunities for the long term management of paper mill biosolids and composted municipal wastes. It is not yet known what the impact of the thick cover layers of organic material will be on the chemistry, hydrology, and stability of the tailings. A column leaching study conducted to assess the net effect of biosolids on tailings has demonstrated an extensive blackening of the biosolids and tailings interface after the application of paper mill biosolids. The black precipitates were identified as iron sulphide. The columns will remain operational for a 3-year period in order to observe longer term interactions. Batch neutralization tests used to stimulate conventional lime and air treatment system for raw water treatments have demonstrated that organic carbon has no significant impact on effluent treatability. It was concluded that growth studies have shown that above ground growth or corn and canola was good, although root growth was poorer than expected. 3 refs., 8 figs.

  9. Acid mine drainage from the Panasqueira mine and its influence on Zêzere river (Central Portugal)

    OpenAIRE

    Candeias, Carla; Ávila, Paula Freire; Silva, Eduardo Ferreira da; Ferreira, Adelaide; Salgueiro, Ana Rita; Teixeira, João Paulo

    2014-01-01

    Available online 25 October 2013 The Panasqueira hydrothermal mineralization, located in central Portugal, is the biggest Sn–W deposit of the Western Europe. The main evidences of the mining exploitation and ore treatment operations are testified with huge tailings, mainly, in the Rio and Barroca Grande areas. The mining and beneficiation processes, at the site, produces metal rich mine wastes. Oxidation of sulfides tailings and flow from open impoundments are responsible for the m...

  10. Posterodorsal Medial Amygdala Mediates Tail-Pinch Induced Food Intake in Female Rats.

    Science.gov (United States)

    Hu, M H; Bashir, Z; Li, X F; O'Byrne, K T

    2016-05-01

    Comfort eating during periods of stress is a common phenomenon observed in both animals and humans. However, the underlying mechanisms of stress-induced food intake remain elusive. The amygdala plays a central role in higher-order emotional processing and the posterodorsal subnucleus of the medial amygdala (MePD), in particular, is involved in food intake. Extra-hypothalamic corticotrophin-releasing factor (CRF) is well recognised for mediating behavioural responses to stress. To explore the possible role of amygdala CRF receptor activation in stress-induced food intake, we evaluated whether a stressor such as tail-pinch, which reliably induces food intake, would fail to do so in animals bearing bilateral neurotoxic lesions of the MePD. Our results showed that ibotenic acid induced lesions of the MePD markedly reduced tail-pinch induced food intake in ovariectomised, 17β-oestradiol replaced rats. In addition, intra-MePD (right side only) administration of CRF (0.002 or 0.02 ng) via chronically implanted cannulae resulted in a dose-dependent increase in food intake, although higher doses of 0.2 and 2 ng CRF had less effect, producing a bell shaped curve. Furthermore, intra-MePD (bilateral) administration of the CRF receptor antagonist, astressin (0.3 μg per side) effectively blocked tail-pinch induced food intake. These data suggest that the MePD is involved in stress-induced food intake and that the amygdala CRF system may be a mediator of comfort eating. © 2016 The Authors. Journal of Neuroendocrinology published by John Wiley & Sons Ltd on behalf of British Society for Neuroendocrinology.

  11. Central Solenoid

    CERN Multimedia

    2002-01-01

    The Central Solenoid (CS) is a single layer coil wound internally in a supporting cylinder housed in the cryostat of the Liquid Argon Calorimeter. It was successfully tested at Toshiba in December 2000 and was delivered to CERN in September 2001 ready for integration in the LAr Calorimeter in 2003. An intermediate test of the chimney and proximity cryogenics was successfully performed in June 2002.

  12. Field experiment on 222Rn flux from reclaimed uranium tailings

    International Nuclear Information System (INIS)

    Hinton, T.G.

    1983-01-01

    Design and construction techniques are described for a 1.6 ha experimental uranium mill tailings reclamation plot. A passive, activated charcoal device was developed and tested for measurements of radon flux. Experiments on radon flux versus overburden depth showed that tailings covered with 1.5 m of revegetated or 0.3 m of bare overburden had exhalation rates comparable to background. Vegetated subplots exhibited a significantly higher (often an order of magnitude) flux than the bare subplots. Results on the variation of flux over time did not reveal any definitive patterns, possibly due to the high variability among replicates. A positive correlation was demonstrated between precipitation and radon flux. This is discussed in detail and possibly explained by the increase in water content of the micropores within the tailings, which increases the emanation coefficient without adversely effecting the diffusion coefficient of the overburden. 30 references, 7 figures, 3 tables

  13. News from the Library: The 'long tail' Library

    CERN Multimedia

    CERN Library

    2012-01-01

    "The term 'long tail' has gained popularity in recent times as describing the retailing strategy of selling a large number of unique items with relatively small quantities sold of each usually in addition to selling fewer popular items in large quantities. The long tail was popularized by Chris Anderson, who mentioned Amazon.com, Apple and Yahoo! as examples of businesses applying this strategy." *   If we leave the business environment and move to the world of libraries, we still see this "long tail". Usually, only a small portion of a library's book collection accounts for the majority of its loans. On the other hand, there are a variety of "niche information needs" that might not be met, as libraries cannot afford to build up huge collections of documents available just-in-case. However, the networked environment of today's libraries can offer a solution. Online networks of libraries ca...

  14. Static magnetic field influence on rat tail nerve function.

    Science.gov (United States)

    Hong, C Z; Harmon, D; Yu, J

    1986-10-01

    Motor nerve conduction and excitability were measured on the tail nerve of anesthetized rats before and after the nerve was exposed perpendicularly to a static electromagnetic field of various intensities and durations. There was no significant change in either the distal latencies or the amplitudes of the compound muscle action potential (CMAP) measured from stimulating the tail nerve after it was exposed to the electromagnetic field with a density up to 1.2 Tesla (T) for a duration of 60 seconds. However, the nerve excitability expressed as changes of the amplitudes of the submaximally evoked CMAP increased significantly when the tail nerve was exposed to a magnetic field with a density higher than 0.5T for more than 30 seconds. The finding that an electromagnetic field increases motor nerve excitability suggests a possible mechanism of its therapeutic effects.

  15. Environmental Risk Assessment System for Phosphogypsum Tailing Dams

    Directory of Open Access Journals (Sweden)

    Xin Sun

    2013-01-01

    Full Text Available This paper may be of particular interest to the readers as it provides a new environmental risk assessment system for phosphogypsum tailing dams. In this paper, we studied the phosphogypsum tailing dams which include characteristics of the pollution source, environmental risk characteristics and evaluation requirements to identify the applicable environmental risk assessment methods. Two analytical methods, that is, the analytic hierarchy process (AHP and fuzzy logic, were used to handle the complexity of the environmental and nonquantitative data. Using our assessment method, different risk factors can be ranked according to their contributions to the environmental risk, thereby allowing the calculation of their relative priorities during decision making. Thus, environmental decision-makers can use this approach to develop alternative management strategies for proposed, ongoing, and completed PG tailing dams.

  16. A case of tail self-mutilation in a cat

    Directory of Open Access Journals (Sweden)

    Zita Talamonti

    2017-03-01

    Full Text Available The present report describes a case of distal tail self-mutilation in a 5-year-old neutered male domestic short-hair cat. The cat started licking his tail few months before the behavioural visit. Because of the severity of the self-induced injuries, the veterinarian performed a surgical partial caudectomy. After 3 months, the excessive self-grooming of the tail recurred. Neurological and dermatological examinations, radiographs, urine and blood tests did not show any abnormalities. During the behavioural visit, through direct observation of the cat’s posture and behavioural history, the pet received a diagnosis of psychogenic alopecia. The cat was treated with clomipramine for 2 months (0.5 mg/kg/PO SID along with behaviour modification and environmental changes. After 1 month, the cat no longer showed excessive self-grooming. Even if no other systemic pathologies were identified, it is always recommended to address these patients with a multidisciplinary approach.

  17. Guidelines for cleanup of uranium tailings from inactive mills

    International Nuclear Information System (INIS)

    Goldsmith, W.A.; Haywood, F.F.; Jacobs, D.G.

    1975-01-01

    Recent experiences in Grand Junction, Colorado, have indicated the significance of uranium tailings as sources of nonoccupational exposure and suggest that current methods for perpetual care and isolation of the large areas covered by tailings piles at inactive mill locations may be inadequate for minimizing human exposure. This paper presents the rationale and the procedures used in reviewing the adequacy of proposed criteria for remedial action at these sites. Exposures due to aquatic, terrestrial, airborne, and direct contamination pathways were compared to determine the most important radionuclides in the pile and their pathways to man. It is shown that the most hazardous components of the tailings are 226 Ra and 230 Th. The long half-lives of these radionuclides require the consideration of continuous occupancy of the vacated site at some future time, even if the immediately projected land use does not anticipate maximum exposure

  18. Efficient simulation of tail probabilities of sums of correlated lognormals

    DEFF Research Database (Denmark)

    Asmussen, Søren; Blanchet, José; Juneja, Sandeep

    We consider the problem of efficient estimation of tail probabilities of sums of correlated lognormals via simulation. This problem is motivated by the tail analysis of portfolios of assets driven by correlated Black-Scholes models. We propose two estimators that can be rigorously shown...... to be efficient as the tail probability of interest decreases to zero. The first estimator, based on importance sampling, involves a scaling of the whole covariance matrix and can be shown to be asymptotically optimal. A further study, based on the Cross-Entropy algorithm, is also performed in order to adaptively...... optimize the scaling parameter of the covariance. The second estimator decomposes the probability of interest in two contributions and takes advantage of the fact that large deviations for a sum of correlated lognormals are (asymptotically) caused by the largest increment. Importance sampling...

  19. Lead isotopes as seepage indicators around a uranium tailings dam

    International Nuclear Information System (INIS)

    Gulson, B.L.; Mizon, K.J.; Korsch, M.J.; Noller, B.N.

    1989-01-01

    Lead isotope ratios and lead concentrations have been measured in water from 26 bores around the Ranger uranium tailings dam, Northern Territory, Australia, and from the dam itself to determine possible migration of lead derived from the radioactive decay of uranium. Lead isotope compositions have also been measured for the particulates retained on selected filters. The concentration of lead in the bore waters is extremely low (usually 206 Pb/ 204 Pb ratio measured in the bore waters differs by more than a factor of 100 from that in the tailings dam and shows no evidence of lead derived from a significant uranium accumulation. It may be possible to distinguish between lead from the tailings dam and that derived from a nearby uranium ore body

  20. Environmental risk assessment system for phosphogypsum tailing dams.

    Science.gov (United States)

    Sun, Xin; Ning, Ping; Tang, Xiaolong; Yi, Honghong; Li, Kai; Zhou, Lianbi; Xu, Xianmang

    2013-01-01

    This paper may be of particular interest to the readers as it provides a new environmental risk assessment system for phosphogypsum tailing dams. In this paper, we studied the phosphogypsum tailing dams which include characteristics of the pollution source, environmental risk characteristics and evaluation requirements to identify the applicable environmental risk assessment methods. Two analytical methods, that is, the analytic hierarchy process (AHP) and fuzzy logic, were used to handle the complexity of the environmental and nonquantitative data. Using our assessment method, different risk factors can be ranked according to their contributions to the environmental risk, thereby allowing the calculation of their relative priorities during decision making. Thus, environmental decision-makers can use this approach to develop alternative management strategies for proposed, ongoing, and completed PG tailing dams.

  1. Accelerating transient drainage from UMTRA Project tailings piles

    International Nuclear Information System (INIS)

    1990-09-01

    The period between the completion of construction of the tailings disposal cell and the establishment of equilibrium moisture content and seepage conditions is considered to be the period of transient drainage. Transient drainage may be due to factors such as construction water, precipitation, or residual water from the milling process. Transient seepage rates usually exceed steady state seepage rates. If the transient seepage rate causes contaminant levels to exceed groundwater compliance standards, then an alternative groundwater compliance strategy or technical approach to reduce or mitigate the effects of the drainage must be adopted. This study examines methods to accelerate the transient drainage of soils and hence to remove excess pore water from tailings in UMTRA Project disposal cells. The technical and economic feasibility of possible methods is examined. In order to perform comparative economical analyses of the various methods, an example tailings pile is postulated. This pile is considered to be 300 meters by 300 meters by 10 meters in thickness

  2. Asphalt emulsion sealing of uranium mill tailings. 1980 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Hartley, J.N.; Koehmstedt, P.L; Esterl, D.J.; Freeman, H.D.; Buelt, J.L.; Nelson, D.A.; Elmore, M.R.

    1981-05-01

    Studies of asphalt emulsion sealants conducted by the Pacific Northwest Laboratory have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to near background levels. Field tests at the tailings pile in Grand Junction, Colorado, confirmed that an 8-cm admix seal containing 22 wt% asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and compacted, overburden was applied over the seal to protect the seal from ultraviolet degradation.

  3. Asphalt emulsion sealing of uranium mill tailings. 1980 annual report

    International Nuclear Information System (INIS)

    Hartley, J.N.; Koehmstedt, P.L; Esterl, D.J.; Freeman, H.D.; Buelt, J.L.; Nelson, D.A.; Elmore, M.R.

    1981-05-01

    Studies of asphalt emulsion sealants conducted by the Pacific Northwest Laboratory have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to near background levels. Field tests at the tailings pile in Grand Junction, Colorado, confirmed that an 8-cm admix seal containing 22 wt% asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and compacted, overburden was applied over the seal to protect the seal from ultraviolet degradation

  4. Commingled uranium-tailings study. Volume II. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-06-30

    Public Law 96-540, Section 213, directs the Secretary of Energy to develop a plan for a cooperative program to provide assistance in the stabilization and management of defense-related uranium mill tailings commingled with other tailings. In developing the plan, the Secretary is further directed to: (1) establish the amount and condition of tailings generated under federal contracts; (2) examine appropriate methodologies for establishing the extent of federal assistance; and (3) consult with the owners and operators of each site. This technical report summarizes US Department of Energy (DOE) and contractor activities in pursuit of items (1), (2), and (3) above. Recommendations regarding policy and a cooperative plan for federal assistance are under separate cover as Volume I.

  5. Radon diffusion in candidate soils for covering uranium mill tailings

    Energy Technology Data Exchange (ETDEWEB)

    Silker, W.B.; Kalkwarf, D.R.

    1983-04-01

    Diffusion coefficients were measured for radon in 34 soils that had been identified by mill personnel as candidate covers for their tailings piles in order to reduce radon emission. These coefficients referred to diffusion in the total pore space of the soils. They were measured in the laboratory by a steady-state method using soil columns compacted to greater than 80% of their Proctor maximum packing densities but with moisture contents generally less than would be expected at a tailings site. An empirical equation was used to extrapolate measured coefficients to value expected at soil-moisture contents representative of tailings sites in the western United States. Extrapolated values for silty sands and clayey sands ranged from 0.004 to 0.06 cm/sup 2//s. Values for inorganic silts and clays ranged from 0.001 to 0.02 cm/sup 2//s.

  6. The Anatomy of the Long Tail of Consumer Demand

    Science.gov (United States)

    Broder, Andrei

    The long tail of consumer demand is consistent with two fundamentally different theories. The first, and more popular hypothesis, is that a majority of consumers have similar tastes and only few have any interest in niche content; the second, is that everyone is a bit eccentric, consuming both popular and niche products. By examining extensive data on user preferences for movies, music, web search, and web browsing, we found overwhelming support for the latter theory. Our investigation suggests an additional factor in the success of "infinite-inventory" retailers such as Netflix and Amazon: besides the significant revenue obtained from tail sales, tail availability may boost head sales by offering consumers the convenience of "one-stop shopping" for both their mainstream and niche interests.

  7. Recent radiochemistry observations at the Riverton and Maybell tailings piles

    International Nuclear Information System (INIS)

    Smith, A.R.; Moed, B.A.

    1982-09-01

    Preliminary results are presented from the radiochemistry effort of the Lawrence Berkeley Laboratory integrated study of the inactive uranium mill tailings sites at Riverton, Wyoming and Maybell, Colorado. These results were obtained primarily by use of #betta#-ray spectrometric techniques, and included both field and laboratory application of NaI(Tl) crystal and Ge-semiconductor detector systems. Current interpretation of this evidence indicated there has been downward migration of uranium within the tailings column since its emplacement, and upward movement of several radionuclides from the tailings into the overlying cover material. The mechanisms responsible for these migrations are believed to involve fluid transport, and are further believed to be active at the present time

  8. Long-term stabilization of uranium mill tailings

    International Nuclear Information System (INIS)

    Voorhees, L.D.; Sale, M.J.; Webb, J.W.; Mulholland, P.J.

    1984-01-01

    The primary hazard associated with uranium mill tailings is exposure to a radioactive gas, radon-222, the concentration of which has been correlated with the occurrence of lung cancer. Previous studies on radon attenuation conclude that the placement of earthen cover materials over the tailings is the most effective technique for reducing radioactive emissions and dispersal of tailings. The success of such a plan, however, is dependent on ensuring the long-term integrity of these cover materials. Soil erosion from water and wind is the major natural cause of destabilizing earthen cover materials. Field data related to the control of soil loss are limited and only indirectly apply to the problem of isolation of uranium mill tailings over very long time periods (up to 80,000 a). However, sufficient information is available to determine benefits that will result from changes in specific design variables and to evaluate the need for different design strategies among potential disposal sites. The three major options available for stabilization of uranium mill tailings are (1) rock cover, (2) soil and revegetation, or (3) a combination of both on different portions of the tailings cover. The optimal choice among these alternatives depends on site-specific characteristics such as climate and local geomorphology and soils, and on design variables such as embankment heights and slopes, modification of upstream drainage, and revegetation practices. Generally, geomorphic evidence suggests that use of soil and vegetation alone will not be adequate to reduce erosion on slopes greater than about 5 to 9%. For these steeper slopes, the use of rock talus or riprap will be necessary to maximize the probability of long-term stability. The use of vegetation to control erosion on the flatter portions of the site may be practicable in regions of the USA with sufficient rainfall and suitable soil types, but revegetation practices must be carefully evaluated to ensure that long

  9. Spectral induced polarization (SIP) response of mine tailings

    Science.gov (United States)

    Placencia-Gómez, Edmundo; Parviainen, Annika; Slater, Lee; Leveinen, Jussi

    2015-02-01

    Mine tailings impoundments are a source of leachates known as acid mine drainage (AMD) which can pose a contamination risk for surrounding surface and groundwater. Methodologies which can help management of this environmental issue are needed. We carried out a laboratory study of the spectral induced polarization (SIP) response of tailings from the Haveri Au-Cu mine, SW Finland. The primary objectives were, (1) to determine possible correlations between SIP parameters and textural properties associated with oxidative-weathering mechanisms, mineralogical composition and metallic content, and (2) to evaluate the effects of the pore water chemistry on SIP parameters associated with redox-inactive and redox-active electrolytes varying in molar concentration, conductivity and pH. The Haveri tailings exhibit well defined relaxation spectra between 100 and 10,000 Hz. The relaxation magnitudes are governed by the in-situ oxidative-weathering conditions on sulphide mineral surfaces contained in the tailings, and decrease with the oxidation degree. The oxidation-driven textural variation in the tailings results in changes to the frequency peak of the phase angle, the imaginary conductivity and chargeability, when plotted versus the pore water conductivity. In contrast, the real and the formation electrical conductivity components show a single linear dependence on the pore water conductivity. The increase of the pore water conductivity (dominated by the increase of ions concentration in solution) along with a transition to acidic conditions shifts the polarization peak towards higher frequencies. These findings show the unique sensitivity of the SIP method to potentially discriminate AMD discharges from reactive oxidation zones in tailings, suggesting a significant advantage for monitoring threatened aquifers.

  10. Langmuir monolayers composed of single and double tail sulfobetaine lipids.

    Science.gov (United States)

    Hazell, Gavin; Gee, Anthony P; Arnold, Thomas; Edler, Karen J; Lewis, Simon E

    2016-07-15

    Owing to structural similarities between sulfobetaine lipids and phospholipids it should be possible to form stable Langmuir monolayers from long tail sulfobetaines. By modification of the density of lipid tail group (number of carbon chains) it should also be possible to modulate the two-dimensional phase behaviour of these lipids and thereby compare with that of equivalent phospholipids. Potentially this could enable the use of such lipids for the wide array of applications that currently use phospholipids. The benefit of using sulfobetaine lipids is that they can be synthesised by a one-step reaction from cheap and readily available starting materials and will degrade via different pathways than natural lipids. The molecular architecture of the lipid can be easily modified allowing the design of lipids for specific purposes. In addition the reversal of the charge within the sulfobetaine head group relative to the charge orientation in phospholipids may modify behaviour and thereby allow for novel uses of these surfactants. Stable Langmuir monolayers were formed composed of single and double tailed sulfobetaine lipids. Surface pressure-area isotherm, Brewster Angle Microscopy and X-ray and neutron reflectometry measurements were conducted to measure the two-dimensional phase behaviour and out-of-plane structure of the monolayers as a function of molecular area. Sulfobetaine lipids are able to form stable Langmuir monolayers with two dimensional phase behaviour analogous to that seen for the well-studied phospholipids. Changing the number of carbon tail groups on the lipid from one to two promotes the existence of a liquid condensed phase due to increased Van der Waals interactions between the tail groups. Thus the structure of the monolayers appears to be defined by the relative sizes of the head and tail groups in a predictable way. However, the presence of sub-phase ions has little effect on the monolayer structure, behaviour that is surprisingly different to

  11. National/international R and D programs on uranium mill tailings

    International Nuclear Information System (INIS)

    Hamel, P.E.

    1981-05-01

    The mining and milling of uranium ores results in the production of large quantities of wastes containing low concentrations of radionuclides such as uranium, thorium, radium, radon and their daughter products. The current concern of the regulatory authorities is with the extent of the problems and the disposal methods that must be required now to ensure that an acceptable level of protection is maintained in the long term. This concern is the subject of a number of R and D programs. In Canada, the Technical Planning Group on Uranium Tailings was established to review ongoing activities and to plan a research program on the management of wastes after the mine and mill have shut down. The Group has completed its review and a report containing its conclusions and recommendations for a proposed national R and D program has been prepared. Included is a proposal for a centralized organizational structure for the coordination and managment of the total program which is to be supported jointly by the federal government, two (Ontario, Saskatchewan) provincial governments, and uranium producers. At the international level, the Nuclear Energy Agency originated, in 1979, a program to study the extent of the long-term problems of uranium mill tailings, and to develop an internationally acceptable methodology for making rational decisions regarding their long-term management taking into account the ICRP principles and system of dose limitation

  12. Sylvatic plague reduces genetic variability in black-tailed prairie dogs.

    Science.gov (United States)

    Trudeau, Kristie M; Britten, Hugh B; Restani, Marco

    2004-04-01

    Small, isolated populations are vulnerable to loss of genetic diversity through in-breeding and genetic drift. Sylvatic plague due to infection by the bacterium Yersinia pestis caused an epizootic in the early 1990s resullting in declines and extirpations of many black-tailed prairie dog (Cynomys ludovicianus) colonies in north-central Montana, USA. Plague-induced population bottlenecks may contribute to significant reductions in genetic variability. In contrast, gene flow maintains genetic variability within colonies. We investigated the impacts of the plague epizootic and distance to nearest colony on levels of genetic variability in six prairie dog colonies sampled between June 1999 and July 2001 using 24 variable randomly amplified polymorphic DNA (RAPD) markers. Number of effective alleles per locus (n(e)) and gene diversity (h) were significantly decreased in the three colonies affected by plague that were recovering from the resulting bottlenecks compared with the three colonies that did not experience plague. Genetic variability was not significantly affected by geographic distance between colonies. The majority of variance in gene fieqnencies was found within prairie clog colonies. Conservation of genetic variability in black-tailed prairie dogs will require the preservation of both large and small colony complexes and the gene flow amonog them.

  13. Uranium Mill Tailings Radiation Control Act of 1978

    International Nuclear Information System (INIS)

    Magee, J.

    1980-01-01

    The long-term environmental effects of the Uranium Mill Tailings Radiation Control Act of 1978 address the public health hazards of radioactive wastes and recognize the significance of this issue to public acceptance of nuclear energy. Title I of the Act deals with stabilizing and controlling mill tailings at inactive sites and classifies the sites by priority. It represents a major Federal commitment. Title II changes and strengthens Nuclear Regulatory Commission authority, but it will have little overall impact. It is not possible to assess the Act's effect because there is no way to know if current technology will be adequate for the length of time required. 76 references

  14. Adoption in rock and white-tailed ptarmigan

    Science.gov (United States)

    Wong, M.M.L.; Fedy, B.C.; Wilson, S.; Martin, K.M.

    2009-01-01

    Reports of adoption in birds are widespread, but few studies report rates of adoption or possible mechanisms for this phenomenon, particularly in the Order Galliformes. We report incidents of adoption in Rock Ptarmigan (Lagopus muta) and White-tailed Ptarmigan (L. leucura) from two sites in western Canada. Adoption rates for White-tailed Ptarmigan on Vancouver Island, British Columbia, and the Ruby Ranges, Yukon Territory were 13% (n = 16 broods) and 4% (n = 27), respectively, while rates for Rock Ptarmigan were 14% (n = 29) in the Ruby Ranges. Low brood densities may result in lower rates of adoption for ptarmigan. ?? 2009 The Wilson Ornithological Society.

  15. Tailings dam-break flow - Analysis of sediment transport

    Science.gov (United States)

    Aleixo, Rui; Altinakar, Mustafa

    2015-04-01

    A common solution to store mining debris is to build tailings dams near the mining site. These dams are usually built with local materials such as mining debris and are more vulnerable than concrete dams (Rico et al. 2008). of The tailings and the pond water generally contain heavy metals and various toxic chemicals used in ore extraction. Thus, the release of tailings due to a dam-break can have severe ecological consequences in the environment. A tailings dam-break has many similarities with a common dam-break flow. It is highly transient and can be severely descructive. However, a significant difference is that the released sediment-water mixture will behave as a non-Newtonian flow. Existing numerical models used to simulate dam-break flows do not represent correctly the non-Newtonian behavior of tailings under a dam-break flow and may lead to unrealistic and incorrect results. The need for experiments to extract both qualitative and quantitative information regarding these flows is therefore real and actual. The present paper explores an existing experimental data base presented in Aleixo et al. (2014a,b) to further characterize the sediment transport under conditions of a severe transient flow and to extract quantitative information regarding sediment flow rate, sediment velocity, sediment-sediment interactions a among others. Different features of the flow are also described and analyzed in detail. The analysis is made by means of imaging techniques such as Particle Image Velocimetry and Particle Tracking Velocimetry that allow extracting not only the velocity field but the Lagrangian description of the sediments as well. An analysis of the results is presented and the limitations of the presented experimental approach are discussed. References Rico, M., Benito, G., Salgueiro, AR, Diez-Herrero, A. and Pereira, H.G. (2008) Reported tailings dam failures: A review of the European incidents in the worldwide context , Journal of Hazardous Materials, 152, 846

  16. Crops for biodiesel to be grown on mine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Ulrichsen, H.

    2007-12-01

    Natural Resources Canada has launched a feasibility project along with several branches of the federal government, provincial government, Laurentian University and mining and forestry companies to determine if crops suitable for producing biodiesel fuel can be grown on mine tailings. The concept first came about when a biodiesel plant was proposed to be built in Sudbury. Although plans for the plant have been abandoned, the biodiesel crop project is still going ahead. Crops will be cultivated on 2 half-hectare plots on the CVRD Inco tailings in Sudbury, 1 half-hectare plot on the Xstrata Nickel tailings in Sudbury and 1 half-hectare plot on the Goldcorp tailings in Timmins. Paper sludge from St. Marys Paper Company in Sault Ste. Marie and Domtar in Espanola will be spread on the plots in January when the frozen ground is easier to work on with heavy equipment. In the spring, the plots will be seeded with corn, canola or soy, with the possibility of alder and willow in the future. Instruments to monitor groundwater on the sites will also be installed. Biodiesel produced with vegetable or meat oils has been touted as being an environmentally sound diesel fuel. Emissions from vehicles fueled by biodiesel are 40 to 100 per cent lower than those from conventional diesel engines. Proponents of the project emphasize the value of using marginal lands like mine tailings to grow crops for biodiesel fuel instead of prime agricultural land. There are 2,500 hectares of tailings in Sudbury that could be potentially used for this purpose, and about 2,000 hectares at one mine site in Timmins. A Sudbury-area farmer will provide advice about growing the crops and will also grow the same crops on a portion of his land for a comparative evaluation of crop yield. The paper sludge offers the benefit of allowing crops to be grown, but it also cuts off oxygen flow to the tailings underneath, thereby preventing sulphides in the tailings from rusting. The paper sludge may even help the

  17. Fast head-tail instability with space charge

    Directory of Open Access Journals (Sweden)

    M. Blaskiewicz

    1998-08-01

    Full Text Available The fast head-tail instability with space charge is studied using series expansion techniques, numerical simulations, and a new formulation which allows for precise estimates of growth rates and thresholds. In regimes where they are reliable, all three techniques predict that space charge suppresses the fast head-tail instability. It is found that the series expansion techniques are unreliable for parameter regimes commonly employed in hadron accelerators. The numerical techniques are less prone to error, but the computational requirements become severe as space charge tune shifts increase. The new model has neither of these problems, but it underestimates the benefits of chromaticity, at least in its simplest form.

  18. Effect of surface treatment of tailings on effluent quality

    International Nuclear Information System (INIS)

    Murray, D.R.; Okuhara, D.

    1980-01-01

    Lysimeters containing 125 tons of mine tailings were used to determine the impact of gravel, sawdust, and vegetation as surface treatments on the quality and quantity of effluent produced from sulfide-containing uranium mill tailings. Over a 5-yr period, treatments did not alter the effluent quality to a level acceptable to regulatory requirements. The concentration of iron, copper, lead, aluminum, and sulfate increased with the rise of acidity during this period. However, the rate and extent of changes did vary with the treatment. The role of surface treatment in long-term waste abandonment must be investigated further

  19. Interior drains for open pit disposal of uranium mill tailings

    International Nuclear Information System (INIS)

    Staub, W.P.

    1978-01-01

    A conceptualized interior drainage system is presented for reducing the environmental impact on natural groundwater by disposal of uranium mill tailings in the mined-out open pit. The evaporation/seepage ratio can be increased through the use of interior drains, long-term monitoring of groundwater quality can be eliminated, and the open pit will not require an extensive liner. Other advantages not related to groundwater are: control of fugitive dust and radon emanation during mill operations and timely reclamation after the impoundment is filled with tailings

  20. Disease Limits Populations: Plague and Black-Tailed Prairie Dogs

    OpenAIRE

    Cully, Jack F.; Johnson, Tammi L.; Collinge, Sharon K.; Ray, Chris

    2010-01-01

    Plague is an exotic vector-borne disease caused by the bacterium Yersinia pestis that causes mortality rates approaching 100% in black-tailed prairie dogs (Cynomys ludovicianus). We mapped the perimeter of the active portions of black-tailed prairie dog colonies annually between 1999 and 2005 at four prairie dog colony complexes in areas with a history of plague, as well as at two complexes that were located outside the distribution of plague at the time of mapping and had therefore never bee...

  1. Improving "tail" computations in a BOINC-based Desktop Grid

    Science.gov (United States)

    Kolokoltsev, Yevgeniy; Ivashko, Evgeny; Gershenson, Carlos

    2017-12-01

    A regular Desktop Grid bag-of-tasks project can take a lot of time to complete computations. An important part of the process is tail computations: when the number of tasks to perform becomes less than the number of computing nodes. At this stage, a dynamic replication could be used to reduce the time needed to complete computations. In this paper, we propose a mathematical model and a strategy of dynamic replication at the tail stage. The results of the numerical experiments are given.

  2. Targeting ADAM12 in human disease: head, body or tail?

    DEFF Research Database (Denmark)

    Jacobsen, J; Wewer, U M

    2009-01-01

    properties. This functional trinity is reflected in the structure of ADAM12, which can be divided into head, body, and tail. The head of the protein (consisting of the pro and catalytic domains) mediates processing of growth factors and cytokines and has been implicated in epidermal growth factor (EGF......) and insulin-like growth factor receptor signaling. The body of the protein (consisting of the disintegrin, cysteine-rich, and EGF-like domains) is involved in contacts with the extracellular matrix and other cells through interactions with integrins and syndecans. Finally, the tail of the protein (consisting...... the possible approaches to targeting ADAM12 in human disease....

  3. Wake patterns of the wings and tail of hovering hummingbirds

    Science.gov (United States)

    Altshuler, Douglas L.; Princevac, Marko; Pan, Hansheng; Lozano, Jesse

    The flow fields of slowly flying bats and fasterflying birds differ in that bats produce two vortex loops during each stroke, one per wing, and birds produce a single vortex loop per stroke. In addition, the circulation at stroke transition approaches zero in bats but remains strong in birds. It is unknown if these difference derive from fundamental differences in wing morphology or are a consequence of flight speed. Here, we present an analysis of the horizontal flow field underneath hovering Anna's hummingbirds (Calypte anna) to describe the wake of a bird flying at zero forward velocity. We also consider how the hummingbird tail interacts with the wake generated by the wings. High-speed image recording and analysis from three orthogonal perspectives revealed that the wing tips reach peak velocities in the middle of each stroke and approach zero velocity at stroke transition. Hummingbirds use complex tail kinematic patterns ranging from in phase to antiphase cycling with respect to the wings, covering several phase shifted patterns. We employed particle image velocimetry to attain detailed horizontal flow measurements at three levels with respect to the tail: in the tail, at the tail tip, and just below the tail. The velocity patterns underneath the wings indicate that flow oscillates along the ventral-dorsal axis in response to the down- and up-strokes and that the sideways flows with respect to the bird are consistently from the lateral to medial. The region around the tail is dominated by axial flows in dorsal to ventral direction. We propose that these flows are generated by interaction between the wakes of the two wings at the end of the upstroke, and that the tail actively defects flows to generate moments that contribute to pitch stability. The flow fields images also revealed distinct vortex loops underneath each wing, which were generated during each stroke. From these data, we propose a model for the primary flow structures of hummingbirds that more

  4. Three Tails of Organizational Innovation: from the Value Creation Perspective

    DEFF Research Database (Denmark)

    Lin, Chih-Cheng; Ma, Zheng

    2012-01-01

    of presenting the organizational innovation process: two-way interactive triggers for organizational innovation integrating three levels – individual, group and organization, and three tails of organizational innovation process. By exploring the organizational innovation process, this study has extended...... and organizations. More importantly, these three tails are not isolated but integrated - this can be viewed as three stages for organizational innovation process.......Several prior articles have emphasized the importance of organizational innovation and change. To advance our understanding, this paper seeks to address the following question: “in what ways the outcome of organizational innovation process distributed over time” by examining organizational...

  5. Research on the characterization and conditioning of uranium mill tailings. III. Summary of uranium mill tailings conditioning research and implications regarding remedial actions

    International Nuclear Information System (INIS)

    Dreesen, D.R.; Cokal, E.J.; Thode, E.F.; Williams, J.M.

    1983-06-01

    This report summarizes the findings of research on uranium mill tailings conditioning technology development performed for the Department of Energy's (DOE) Uranium Mill Tailings Remedial Action Project (UMTRAP). Hazards and risks posed by tailings piles are discussed in relation to the goal of conditioning the tailings to reduce these hazards. The results of our efforts regarding characterization of tailings, removal of radionuclides, mineral recovery, thermal stabilization, and engineering/economic analysis of conditioning are presented. The implications of these results for remedial action plans are discussed and conclusions regarding the applicability of these technologies are also presented

  6. Removal of 226Ra from tailings pond effluents and stabilization of uranium mine tailings. Bench and pilot scale studies

    International Nuclear Information System (INIS)

    Schmidtke, N.W.; Averill, D.; Bryant, D.N.; Wilkinson, P.; Schmidt, J.W.

    1978-01-01

    Increased world demand for uranium has resulted in recent expansion of Canadian uranium mining operations. Problems have been identified with the discharge of radionuclides such as 226 Ra from tailings pond effluents and with the stabilization of mine tailings. At Environment Canada's Wastewater Technology Centre (WTC) two projects were undertaken in cooperation with the Canadian Uranium Mining Industry and other federal government agencies to address these problems. The first project reports on the progress of bench and pilot scale process simulations for the development of a data base for the design of a full scale mechanical physical/chemical 226 Ra removal waste treatment system with an effluent target level of 10 pCi 226 Ra total per litre. The second project addresses problems of the leachability of radionuclides and the stabilization of both uranium mine tailings and BaRaSO 4 sediments from the treatment of acid seepages

  7. Health evaluation of Columbian white-tailed deer on Julia Butler Hansen Refuge for the Columbian white-tailed deer

    Science.gov (United States)

    Creekmore, Terry E.; Glaser, Linda C.

    1999-01-01

    The Columbian white-tailed deer ( Odocoileus virginianus leucurus) was designated an endangered species in 1968. At that time the estimated population along the lower Columbia River of Washington and Oregon was 300 to 400 deer (Gavin, 1984). The Julia Butler Hansen Refuge for the Columbian White-tailed Deer was established in 1972 to protect Columbian white-tailed deer and associated habitat Currently, an estimated 600 deer are present in several separate populations. The total refuge population is estimated at 200 animals. Of those, the mainland population consists of approximately 60 animals while the largest refuge island (Tenasillahe.Island) supports about 120 animals. The remaining 420 deer are present on private lands near the refuge (AI Clark, pers. com.).

  8. Central sleep apnea

    Science.gov (United States)

    Sleep apnea - central; Obesity - central sleep apnea; Cheyne-Stokes - central sleep apnea; Heart failure - central sleep apnea ... Central sleep apnea results when the brain temporarily stops sending signals to the muscles that control breathing. The condition ...

  9. Dynamical Structure of the Cross-tail Current Sheet During Substorms Observed by Cluster

    Science.gov (United States)

    Asano, Y.; Nakamura, R.; Runov, A.; Takada, T.; Baumjohann, W.; Balogh, A.; Klecker, B.; Rème, H.

    2005-12-01

    We report on the dynamical variation of the current sheet structure in the magnetotail using magnetic field and plasma data obtained by the Cluster multi-satellites. It is found that in some cases the thickness of the cross-tail current sheet shows temporal variations repeatedly. This sausage-mode-like variation is associated with substorm onsets or occurrence of fast plasma flows, with the time scale of several minutes before substorm onsets or fast flows and of a half to one minute afterwards. It frequently coexists with kink-mode-like wave or flapping motion. Such sausage-mode-like variation is mainly observed in the central part of the plasma sheet, and forms transient bifurcated currents or the intense current in the center.

  10. teashirt is required for head-versus-tail regeneration polarity in planarians.

    Science.gov (United States)

    Owen, Jared H; Wagner, Daniel E; Chen, Chun-Chieh; Petersen, Christian P; Reddien, Peter W

    2015-03-15

    Regeneration requires that the identities of new cells are properly specified to replace missing tissues. The Wnt signaling pathway serves a central role in specifying posterior cell fates during planarian regeneration. We identified a gene encoding a homolog of the Teashirt family of zinc-finger proteins in the planarian Schmidtea mediterranea to be a target of Wnt signaling in intact animals and at posterior-facing wounds. Inhibition of Smed-teashirt (teashirt) by RNA interference (RNAi) resulted in the regeneration of heads in place of tails, a phenotype previously observed with RNAi of the Wnt pathway genes β-catenin-1, wnt1, Dvl-1/2 or wntless. teashirt was required for β-catenin-1-dependent activation of posterior genes during regeneration. These findings identify teashirt as a transcriptional target of Wnt signaling required for Wnt-mediated specification of posterior blastemas. © 2015. Published by The Company of Biologists Ltd.

  11. Establishing Cynodon dactylon on mining tailings and mining ...

    African Journals Online (AJOL)

    Mining for copper and cobalt generates extensive mounds of removed topsoil and subsoil, and tailings with toxic levels of copper and cobalt. The threat of soil erosion in a high rainfall regime can be countered with rapid establishment of a sod-forming grass, such as Cynodon dactylon, that covers and binds the soil.

  12. Establishing vegetation on Kimberlite mine tailings: 2. Field trials. | N ...

    African Journals Online (AJOL)

    A series of field experiments were carried out on Kimberlite mine tailing located at Cullinan in the Transvaal. The most successful species in pure sward were Chloris gayana, Cynodon aethiopicus, Eragrostis curvula, E. tef, Pennisetum purpureum, Melilotus alban and Medicago sativa. Growth of grasses in the absence of ...

  13. Characterisation of gold tailings dams of the Witwatersrand Basin ...

    African Journals Online (AJOL)

    The oxygen diffusion data reveal that the flow of oxygen in the Witwatersrand tailings dams is controlled by secondary porosity (i.e. cracks caused by roots on the dam surface). The age of the dam does not have a significant bearing on the extent to which the oxidised zone development and subsequently AMD can progress.

  14. High resolution flow field prediction for tail rotor aeroacoustics

    Science.gov (United States)

    Quackenbush, Todd R.; Bliss, Donald B.

    The prediction of tail rotor noise due to the impingement of the main rotor wake poses a significant challenge to current analysis methods in rotorcraft aeroacoustics. This paper describes the development of a new treatment of the tail rotor aerodynamic environment that permits highly accurate resolution of the incident flow field with modest computational effort relative to alternative models. The new approach incorporates an advanced full-span free wake model of the main rotor in a scheme which reconstructs high-resolution flow solutions from preliminary, computationally inexpensive simulations with coarse resolution. The heart of the approach is a novel method for using local velocity correction terms to capture the steep velocity gradients characteristic of the vortex-dominated incident flow. Sample calculations have been undertaken to examine the principal types of interactions between the tail rotor and the main rotor wake and to examine the performance of the new method. The results of these sample problems confirm the success of this approach in capturing the high-resolution flows necessary for analysis of rotor-wake/rotor interactions with dramatically reduced computational cost. Computations of radiated sound are also carried out that explore the role of various portions of the main rotor wake in generating tail rotor noise.

  15. Dominance hierarchy and social grooming in female lion-tailed ...

    Indian Academy of Sciences (India)

    This article reports the structure of dominance and its relationship with social grooming in wild lion-tailed macaque females. The strength of dominance hierarchy was 0.79 on a scale of 0 to 1 indicating a moderate linearity in the ranking system. Dominance scores were converted into an ordinal as well as an interval scale.

  16. Biota of uranium mill tailings near the Black Hills

    Science.gov (United States)

    Mark A. Rumble

    1982-01-01

    Reclamation" often implies the enhancement of the land as wildlife habitat or for other productive uses. However, there are situations where revegetation to stabilize erosion is the only desired goal. Uranium mining and mill sites may fall into this later category. Data pertaining to plant and animal components on revegetated uranium mill tailings was collected....

  17. The price of portfolio selection under tail conditional expectation with ...

    African Journals Online (AJOL)

    One of the ways of managing the risk that can arise from the changes in the relationship between assets and liabilities is by asset-liability management. Recently, Value-at-risk (VaR) and tail conditional expectation (TCE) have also emerged as standard tools for measuring and controlling the risk of trading portfolios.

  18. On robust tail index estimation under random censorship | Sayah ...

    African Journals Online (AJOL)

    type distributions in the framework of randomly censored samples, based on the ideas of Kaplan-Meier integration using the huberized M-estimator of the tail index. We derive their asymptotic results. We illustrate the performance and the ...

  19. Tail asymptotics of the M/G/∞ model

    NARCIS (Netherlands)

    Mandjes, M.; Zuraniewski, P.W.

    2011-01-01

    This paper considers the so-called M/G/∞ model: jobs arrive according to a Poisson process with rate λ, and each of them stays in the system during a random amount of time, distributed as a non-negative random variable B; throughout it is assumed that B is light-tailed. With N(t) denoting the number

  20. Haemorrhagic pseudocyst of the pancreatic tail causing acute ...

    African Journals Online (AJOL)

    Haemorrhagic pseudocyst of the pancreatic tail causing acute abdominal pain in a 12-year-old girl ... Introduction. The acute abdomen in childhood has various aetiologies and represents a leading cause of hospitalization of children [1]. ... The decision was made to manage the patient surgically because of her progressive ...

  1. North European short-tailed breeds of sheep: a review.

    Science.gov (United States)

    Dýrmundsson, O R; Niżnikowski, R

    2010-08-01

    The short-tailed sheep, native of an area stretching from Russia to Iceland, are generally considered a primitive type. These robust northern sheep seem to have been spread by Norse vikings to several countries in this area from the late eighth century to the middle of the eleventh century ad. They have several common characteristics in addition to the fluke-shaped and tapered short tail, such as a wide range of colour patterns, dual-coated wool and the ability to thrive under harsh environmental conditions, often in isolated marginal areas. While 34 short-tailed breeds of North European origin can still be identified, it is clear that their population sizes have declined in most cases and several of them are now rare and endangered. Although these breeds have mainly been confined to certain localities, some of them have gained considerable distribution due to their genetic merits, such as prolificacy. Of these, the Finnsheep and the Romanov are best known being exported to several countries in the world where their genetic material has been utilized through crossbreeding with local sheep. This has resulted in the production of some new synthetic breeds. Meat is now generally the main product of the North European short-tailed breeds and their crossbreds, whereas wool, skins and milk are normally regarded as byproducts, yet of considerable economic importance in some cases. Such breeds have clearly a role to play in sustainable grassland-based production systems in the future.

  2. Bounds for Tail Probabilities of the Sample Variance

    Directory of Open Access Journals (Sweden)

    V. Bentkus

    2009-01-01

    Full Text Available We provide bounds for tail probabilities of the sample variance. The bounds are expressed in terms of Hoeffding functions and are the sharpest known. They are designed having in mind applications in auditing as well as in processing data related to environment.

  3. Faun tail: a rare cutaneous sign of spinal dysraphism.

    Science.gov (United States)

    Kurtipek, Gülcan Saylam; Cihan, Fatma Göksin; Öner, Vefa; Ataseven, Arzu; Özer, İlkay; Akman, Zahide

    2015-01-01

    Faun tail is a triangle-shaped hypertrichosis of the lumbosacral region. It is a rare condition and it can be a cutaneous marker of underlying spinal cord anomaly. We report on a 17-year-old female patient with hypertrichosis on the lumbosacral area since birth that was later diagnosed with tethered cord in magnetic resonance imaging.

  4. Active vertical tail buffeting suppression based on macro fiber composites

    Science.gov (United States)

    Zou, Chengzhe; Li, Bin; Liang, Li; Wang, Wei

    2016-04-01

    Aerodynamic buffet is unsteady airflow exerting forces onto a surface, which can lead to premature fatigue damage of aircraft vertical tail structures, especially for aircrafts with twin vertical tails at high angles of attack. In this work, Macro Fiber Composite (MFC), which can provide strain actuation, was used as the actuator for the buffet-induced vibration control, and the positioning of the MFC patches was led by the strain energy distribution on the vertical tail. Positive Position Feedback (PPF) control algorithm has been widely used for its robustness and simplicity in practice, and consequently it was developed to suppress the buffet responses of first bending and torsional mode of vertical tail. However, its performance is usually attenuated by the phase contributions from non-collocated sensor/actuator configuration and plants. The phase lag between the input and output signals of the control system was identified experimentally, and the phase compensation was considered in the PPF control algorithm. The simulation results of the amplitude frequency of the closed-loop system showed that the buffet response was alleviated notably around the concerned bandwidth. Then the wind tunnel experiment was conducted to verify the effectiveness of MFC actuators and compensated PPF, and the Root Mean Square (RMS) of the acceleration response was reduced 43.4%, 28.4% and 39.5%, respectively, under three different buffeting conditions.

  5. Ecosystem recovery analysis of mine tailings at Mhangura copper ...

    African Journals Online (AJOL)

    Remote sensing techniques are increasingly being employed in monitoring environmental change. Vegetation indices such as normalised difference vegetation index (NDVI), are useful in estimating primary production, an important component of ecosystem function. The success of rehabilitation on mine tailings may be ...

  6. Do different subspecies of Black-tailed Godwit

    NARCIS (Netherlands)

    Lopes, R.J.; Alves, J.A.; Gill, J.A.; Gunnarsson, T.G.; Hooijmeijer, J.C.E.W.; Lourenço, P.M.; Masero, J.A.; Piersma, T.; Potts, P.M.; Rabaçal, B.; Reis, S.; Sánchez-Guzmán, J.M.; Santiago-Quesada, F.; Villegas, A.

    2013-01-01

    Resolving the migratory connectivity (identifying non-breeding grounds) of migrating bird populations that are morphologically similar is crucial for an understanding of their population dynamics and ultimately their conservation. Such is the case in Black-tailed Godwits Limosa limosa, where the

  7. Tail asymptotics for dependent subexponential differences

    DEFF Research Database (Denmark)

    Albrecher, H; Asmussen, Søren; Kortschak, D.

    We study the asymptotic behavior of P(X − Y > u) as u → ∞, where X is subexponential and X, Y are positive random variables that may be dependent. We give criteria under which the subtraction of Y does not change the tail behavior of X. It is also studied under which conditions the comonotonic co...

  8. Effect of surface treatment of tailings on effluent quality

    International Nuclear Information System (INIS)

    Murray, D.R.

    1980-01-01

    Successful reclamation treatment, in preparation for long range abandonment of mining wastes, involves both surface treatment and water quality control containment of waste solids and liquid contaminants. This paper describes use of lysimeters containing 125 tonnes of tailings to determine the impact of gravel, sawdust, and vegetation as surface treatments on the quality and quantity of effluent produced from sulphide-containing uranium mill tailings. Over a five-year period these treatments were observed and compared with bare tailings where no surface addition was made. The treatments did not alter the effluent quality to a level acceptable to regulatory requirements. Surface treatments did not appear to affect the leaching of Ra-226, NH 4 and NO 3 . The concentration of Fe, SO 4 , Cu, Pb, and Al increased with the rise of acidity as the pH changed from pH 9.5 to pH 2 in four and one-half years. However the rate and extent of changes of some of these parameters vary with the treatment. The experimental results for the observed trends are presented with limited explanation. Original design problems and unexpected delays in tailing reactions have made firm conclusions impossible at this stage. These data, however, provide a base for further investigation and development of explanations and firm conclusions, as to the role of surface treatment in long-term waste abandonment

  9. Studies on Arsenic Release and its Mitigation from Tailings Dam ...

    African Journals Online (AJOL)

    user

    dispersive spectroscopy (SEM-EDX). Polished mounts (< 45 µm) with average diameters and thickness of 3 cm and 1 cm respectively were prepared with the tailings material using conducting graphite doped epoxy. This was then carbon coated for the SEM-EDX analysis in order to prevent elec- tron build up on the sample ...

  10. Gold tailings as a source of waterborne uranium contamination of ...

    African Journals Online (AJOL)

    Dissolved uranium (U) from the tailings deposits of various gold mines in South Africa has been found to migrate via seepage and groundwater into adjacent streams. The extent of the associated non-point pollution depends on the concentration of U in the groundwater as well as the volume and rate of groundwater ...

  11. Survival of white-tailed deer neonates in Louisiana

    Science.gov (United States)

    Rebecca M. Shuman; Michael J. Cherry; Taylor N. Simoneaux; Elizabeth A. Dutoit; John C. Kilgo; Michael J. Chamberlain; Karl V. Miller

    2017-01-01

    Changing predator communities have potential to complicate management focused on ensuring sustainable white-tailed deer (Odocoileus virginianus) populations. Recent research reported that predation on neonates by coyotes (Canis latrans) and bobcats (Lynx rufus) can limit recruitment. However, no research has been conducted in areas of the southeastern United States...

  12. The utilization of forward osmosis for coal tailings dewatering

    Science.gov (United States)

    The feasibility of dewatering coal tailings slurry by forward osmosis (FO) membrane process was investigated in this research. A prototype cell was designed and used for the dewatering tests. A cellulosic FO membrane (Hydration Technology Innovations, LLC, Albany, OR) was used fo...

  13. Electrodialytic remediation of copper mine tailings: Comparing different operational conditions

    DEFF Research Database (Denmark)

    Rojo, Adrian; Hansen, Henrik K.; Ottosen, Lisbeth M.

    2006-01-01

    This work compares and evaluates sixteen electrodialytic laboratory remediation experiments on copper mine tailings. Different parameters were analyzed, such as remediation time, voltage drop, addition of desorbing agents, and the use of pulsed electrical fields. The results show that electric cu...

  14. Architecture and environmental restoration: Remediating uranium mill tailings from buildings

    International Nuclear Information System (INIS)

    Teply, J.D.

    1991-01-01

    The US Department of Energy (DOE) Grand Junction Projects Office (GJPO) manages the Uranium Mill Tailings Remedial Action (UMTRA) Program in Grand Junction, Colorado. This program is a congressionally mandated clean up of by-product waste that resulted from the extraction of yellow cake from uranium ore. The by-product waste, a fine sand commonly called open-quotes mill tailingclose quotes is contaminated with low-level radioactivity. These mill tailings were available to the community for use as construction material from approximately 1952 to 1966; their use as bedding material for concrete slabs, utilities, backfill materials, concrete sand, and mortar created unique remediation problems that required innovative solutions. This paper describes how design personnel approach the remediation of structures, the evaluation of the buildings, and the factors that must be considered in completing the remediation design. This paper will not address the health risks of the tailings in an inhabited space, the remediation of exterior areas, or the process of determining where the tailings exist in the building

  15. Cleaning up commingled uranium mill tailings: is Federal assistance necessary

    International Nuclear Information System (INIS)

    1979-01-01

    GAO was asked to determine whether Federal assistance should be given to operating mill owners that have processed uranium for sale to both government and industry and, thus, generated residual radioactive wastes. The wastes generated for both government and commercial use are called commingled uranium mill tailings. GAO recommends that the Congress provide assistance to active mill owners to share in the cost of cleaning up that portion of the tailings which were produced under Federal contract. Further, GAO believes that the Congress should also consider having the Federal government assist those mills who acted in good faith in meeting all legal requirements pertaining to controlling the mill tailings that were generated for commercial purposes and for which the Federal government is now requiring retroactive remedial action. At the same time, the Congress should make sure that this action establishes no precedent for the Federal government assuming the financial responsibility of cleaning up other non-Federal nuclear facilities and wastes, including those mill tailings generated after the date when the Federal government notified industry that the failings should be controlled

  16. Bias-corrected estimation of stable tail dependence function

    DEFF Research Database (Denmark)

    Beirlant, Jan; Escobar-Bach, Mikael; Goegebeur, Yuri

    2016-01-01

    We consider the estimation of the stable tail dependence function. We propose a bias-corrected estimator and we establish its asymptotic behaviour under suitable assumptions. The finite sample performance of the proposed estimator is evaluated by means of an extensive simulation study where...

  17. Reading Confidence with "Tail Waggin' Tutors"

    Science.gov (United States)

    Loveridge, Stacy

    2017-01-01

    This report discusses the benefits of canine-assisted reading through the "Tail Waggin' Tutors" program at the Glen Burnie Regional Library in Anne Arundel County, Maryland. Presented are the two different types of therapy dog interactions, Animal-Assisted Therapy (AAT) and Animal-Assisted Activities (AAA). The first canine-assisted…

  18. Identification of geobacter populations in the uranium mill tailings Shiprock

    International Nuclear Information System (INIS)

    Radeva, G.; Selenska-Pobell, S.

    2006-01-01

    Geobacter - specific primers were used for construction of a 16S rDNA library for a water sample collected from uranium mill tailings near Shiprock (Sh853) in the USA . Most of the retrieved sequences were affiliated with different Geobacter species, however sequences related to other δ -Proteobacteria were identified as well. (authors)

  19. One-Tube Isolation of DNA from Mouse Tails.

    Science.gov (United States)

    Green, Michael R; Sambrook, Joseph

    2018-02-01

    This protocol describes a variation of a simple method for isolation of DNA from mouse tails that uses commercially available gel-barrier tubes to eliminate the tedious transfer of samples during serial extractions with organic solvents. This variant is useful when processing very large numbers of samples. © 2018 Cold Spring Harbor Laboratory Press.

  20. Genetic variations between indigenous fat-tailed sheep populations

    African Journals Online (AJOL)

    ONOS

    2010-09-06

    Sep 6, 2010 ... 2Department of Animal Science, faculty of agriculture, University of Arak, Arak, Iran. . Accepted 10 May, 2010. Blood samples were collected from a total 816 sheep of both sexes in three Iranian fat-tailed breeds. (Sangsari, Makoei, indigenous sheep on firoozkouh mountain) serum, plasma and erythrocyte ...

  1. Dominance hierarchy and social grooming in female lion-tailed ...

    Indian Academy of Sciences (India)

    Madhu

    This article reports the structure of dominance and its relationship with social grooming in wild lion-tailed macaque females. The strength of dominance hierarchy ... study of social organization (Thierry et al 2004). A key factor that helps understand social organization is the dominance relationships among individuals of a ...

  2. Long memory and tail dependence in trading volume and volatility

    DEFF Research Database (Denmark)

    Rossi, Eduardo; Santucci de Magistris, Paolo

    2013-01-01

    We investigate the relationship between volatility, measured by realized volatility, and trading volume for 25 NYSE stocks. We show that volume and volatility are long memory but not fractionally cointegrated in most cases. We also find right tail dependence in the volatility and volume innovations...

  3. The evolutionary strata of DARPP-32 tail implicates hierarchical ...

    Indian Academy of Sciences (India)

    The evolutionary strata of DARPP-32 tail implicates hierarchical functional expansion in higher vertebrates. CHOONG YONG UNG and TEOW CHONG TEOH. Supplementary data 1. Protein sequences of PPP1R1 family from 39 vertebrate species in FASTA format. Supplementary data 2. Multiple sequence alignment results ...

  4. Diseases of white-tailed deer. Chapter 5. Neoplasia

    Energy Technology Data Exchange (ETDEWEB)

    Cosgrove, G. E.; Satterfield, L. D.; Nettles, V. F.

    1977-01-01

    Data on the occurrence and etiology of neoplasms in native populations of white-tailed deer are reviewed. Cutaneous fibromas, non-progressive lesions considered to be of viral etiology, are discussed in detail. The clinical signs associated with other benign and malignant neoplasms are discussed briefly. 30 references.

  5. Treatment of Iron Tailings at the Forecariah Guinea Mine - Guinea ...

    African Journals Online (AJOL)

    Michael

    2016-06-01

    Jun 1, 2016 ... Kali, A. and Buah, W. K. (2016), “Treatment of Iron Tailings at the Forecariah Guinea Mine - Guinea ... subsidiary of Bellzone Australia, mines and export .... of water. Chemical analysis of the feed, magnetics and non-magnetics samples generated from the test work was performed using XRF. A number of ...

  6. A tail bound for read-k families of functions

    Czech Academy of Sciences Publication Activity Database

    Gavinsky, Dmitry; Lovett, S.; Saks, M.; Srinivasan, S.

    2015-01-01

    Roč. 47, č. 1 (2015), s. 99-108 ISSN 1042-9832 Institutional support: RVO:67985840 Keywords : tail bound * deviation bound * random variables Subject RIV: BA - General Mathematics Impact factor: 1.011, year: 2015 http://onlinelibrary.wiley.com/doi/10.1002/rsa.20532/abstract

  7. Speech-like orofacial oscillations in stump-tailed macaque (Macaca arctoides) facial and vocal signals.

    Science.gov (United States)

    Toyoda, Aru; Maruhashi, Tamaki; Malaivijitnond, Suchinda; Koda, Hiroki

    2017-10-01

    Speech is unique to humans and characterized by facial actions of ∼5 Hz oscillations of lip, mouth or jaw movements. Lip-smacking, a facial display of primates characterized by oscillatory actions involving the vertical opening and closing of the jaw and lips, exhibits stable 5-Hz oscillation patterns, matching that of speech, suggesting that lip-smacking is a precursor of speech. We tested if facial or vocal actions exhibiting the same rate of oscillation are found in wide forms of facial or vocal displays in various social contexts, exhibiting diversity among species. We observed facial and vocal actions of wild stump-tailed macaques (Macaca arctoides), and selected video clips including facial displays (teeth chattering; TC), panting calls, and feeding. Ten open-to-open mouth durations during TC and feeding and five amplitude peak-to-peak durations in panting were analyzed. Facial display (TC) and vocalization (panting) oscillated within 5.74 ± 1.19 and 6.71 ± 2.91 Hz, respectively, similar to the reported lip-smacking of long-tailed macaques and the speech of humans. These results indicated a common mechanism for the central pattern generator underlying orofacial movements, which would evolve to speech. Similar oscillations in panting, which evolved from different muscular control than the orofacial action, suggested the sensory foundations for perceptual saliency particular to 5-Hz rhythms in macaques. This supports the pre-adaptation hypothesis of speech evolution, which states a central pattern generator for 5-Hz facial oscillation and perceptual background tuned to 5-Hz actions existed in common ancestors of macaques and humans, before the emergence of speech. © 2017 Wiley Periodicals, Inc.

  8. Application of dry stackable tailings technologies : providing the base for reclamation

    Energy Technology Data Exchange (ETDEWEB)

    Mikula, R.J. [Natural Resources Canada, Devon, AB (Canada). CANMET Energy Technology Centre

    2010-07-01

    The tailings containment structures are some of the largest man made features on the planet. This presentation demonstrated that dry stackable tailings technology may reduce the volume of the accumulated fluid fine tailings. Dry stackable tailings can contribute to boreal forest reclamation and reduce water requirement from the Athabasca River. Much of the water used for the production of each barrel of bitumen is recycled. The water is tied up in the pore spaces of the mineral sand, silt, and clay component which forms the mature fine tailings (MFT) that are contained behind large dykes. Syncrude and Suncor have used a wide variety of technologies to create a dry stackable tailings from this fluid fine tailings substrate. The availability of dry stackable tailings will open options for reclamation strategies that end with the original wetlands or boreal forest. Some of the tailings management options that would lead to a dry stackable tailings naturally also significantly decrease the barrels of water lost with each barrel of bitumen production. These options were discussed along with an analysis of their impact on recycle and pore water quality and quantity. There is an opportunity to remove residual bitumen during the transfer of fluid fine tailings to recover water and create dry stackable tailings. If this bitumen removal is extensive enough, it might be possible to use the dry stackable tailings directly as a reclamation material. tabs., figs.

  9. Performance of waste-based amendments to reduce metal release from mine tailings: One-year leaching behaviour.

    Science.gov (United States)

    Rodríguez, Luis; Gómez, Rocío; Sánchez, Virtudes; Villaseñor, José; Alonso-Azcárate, Jacinto

    2018-03-01

    A one-year leaching experiment has been conducted in order to assess the effectiveness of several amendments on metal immobilization in mine tailings from an old Pb/Zn mining area of Central Spain (San Quintín mine). Demineralized water was used as leaching solution, selecting doses equivalent to the annual rainfall conditions of the studied area. Columns with mine tailings without any amendment and others treated with 10% of sugar foam (SF), 15% of drinking water treatment sludge (DWS), 30% of paper mill sludge (PMS) and 15% of olive mill waste (OMW) were used. SF, DWS and PMS amendments increased the pH of leachates from values of approximately 4 to around neutrality. Additionally, the release of sulfate ions from the oxidation of pyritic residues was decreased in some extent by SF and DWS amendments. Metal leaching was effectively reduced by the amendments reaching overall decreases with respect to the unamended columns of 79-96% for Pb, 36-100% for Zn, 50-99% for Cu and 44-100% for Cd. The effect of the amendments in leachate pH, sulfate concentration and metal release from mine tailings was kept throughout the whole experimental period. Our results showed that the application of different organic and inorganic amendments based on by-products and waste materials may be a feasible alternative for the restoration of soils around abandoned metal mines. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. FINAL TAILINGS OF METAL-WORKING PRODUCTION. Part 3. PHYSICO-MECHANICAL CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    O. M. Djakonov

    2011-01-01

    Full Text Available The indices of adhesion and friability of metal-containing tailings, their water absorbency and wettability and also abrasive characteristics of tailings with the purpose of prevention of contacting surfaces wear are studied.

  11. Preliminary results on tail energetics in the Moorish gecko, Tarentola mauritanica

    Directory of Open Access Journals (Sweden)

    Tommaso Cencetti

    2011-06-01

    Full Text Available The amount of lipids, proteins, ashes and water in original versus regenerated tails in Tarentola mauritanica shows differences, especially on the lipid fraction, supporting adaptive function hypotheses during reproduction of regenerated tails in geckos.

  12. Development of the disposal technology research component of the national uranium tailings program

    International Nuclear Information System (INIS)

    Melis, L.A.

    1983-03-01

    The National Technical Planning Group on Uranium Tailings Research, organized by CANMET in 1980, recommended the establishment of a National Uranium Tailings Program to develop research on the long-term abandonment of uranium mine tailings. This report deals with the disposal technology component of this program and attempts to provide recommendations with respect to potential research avenues in this area. A description of uranium tailings in Canada is provided in order to identify the current situation with uranium tailings management. Uranium mining sites described include the Elliot Lake and Bancroft area of Ontario, the northern Saskatchewan properties and the two abandoned sites in the North West Territories. The description of the sites was facilitated by subdividing the tailings into inactive sites, active sites, new tailings sites and areas of tailings in a close-out situation. Methods identified as promising include subsurface disposal, in-situ leaching, prevention of pyrite oxidation and reclamation studies at abandoned sites

  13. Recycling of asbestos tailings used as reinforcing fillers in polypropylene based composites.

    Science.gov (United States)

    Zhai, Wensi; Wang, Yao; Deng, Yuan; Gao, Hongli; Lin, Zhen; Li, Mao

    2014-04-15

    In this work, asbestos tailings were recycled and used as reinforcing fillers to enhance the mechanical properties of polypropylene (PP). A silane coupling agent was used to chemically modify the asbestos tailings to increase the compatibility between asbestos tailings and polypropylene matrix. Both raw and chemically treated asbestos tailings with different loading levels (from 3 to 30 wt%) were utilized to fabricate composites. Mechanical properties of these composites have been investigated by dynamic mechanical analysis, tensile test and notched impact test. Results showed that hybridization of asbestos tailings in the composites enhanced the mechanical properties of neat PP evidently, and treated asbestos tailings/PP composites yielded even better mechanical properties compared with those of raw asbestos tailings/PP composites. This recycling method of asbestos tailings not only reduces disposal costs and avoids secondary pollution but also produces a new PP-based composite material with enhanced mechanical properties. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Estimates of population distributions and tailings areas around licensed uranium mill sites. Final report

    International Nuclear Information System (INIS)

    Hans, J.M.; Hall, J.B.; Moore, W.E.

    1986-08-01

    Population distributions and tailings areas were estimated from aerial photography for each of 21 licensed uranium millsites. Approximately 11,600 persons live within 5 kilometers of the tailings impoundments at the millsites. About 82% of these persons live near five of the millsites. No persons were found living within 5 kilometers of six of the millsites. Tailings area measurements include the surface area of tailings in impoundments, heap-leached ore, and carryover tailings in evaporation ponds. Approximately 4,000 acres of tailings surfaces were measured for the 21 millsites. About 55% of the tailings surfaces were dry, 11% wet, and the remainder ponded. The average tailings surface area for the millsites is about 200 acres and ranges from 7 to 813 acres

  15. Natural radionuclides in bauxitic tailings (Red-Mud) in the Gulf of Corinth, Greece

    International Nuclear Information System (INIS)

    Papatheodorou, G.; Maratou, A.; Ferentinos, G.; Papaefthymiou, H.

    2004-01-01

    A detailed environmental survey was carried out in the central Gulf of Corinth in order to determine radionuclides in the bauxite ed-mud tailings which have been discharged on the sea floor by a Bauxite Processing Plant (Aluminio Ellados A.E). The discharge of bauxitic tailings via two pipelines at a water depth of 100 m, in Antikyra Bay (Northern Gulf of Corinth), has resulted in the formation of two red-mud mound-like deposits. The red-mud deposits at the mouth of the out falls, are not stable and very often red-mud masses are detached from the two main deposits and are transported to the Corinth central basin, by turbidity currents, at a water depth of 850 m and about 17 km away from the main deposits. Thus, at the Antikyra bay, the red-mud has formed a surficial veneer (0.5-2.0 cm) on the sea floor. On the Corinth central basin floor the red mud has formed successive red-mud layers which are interrupted by layers of natural mud. Fifteen gravity cores have been selected from the studied area and a number of bauxite samples have been collected from mines that supply the bauxite processing plant. Red-mud, natural mud and bauxite samples were analyzed for 238 U 226 Ra, 232 Th, 40 K, and 137 Cs by direct gamma spectrometry. The study of radionuclides concentrations has shown that: (a) the enrichment factor of radionuclides in the red-mud in the main deposit at the mouth of the out falls, in relation to bauxite samples, is about 2.0, (b) the enrichment factor of 238 U, 226 Ra and 232 Th in the red-mud in the main deposit and the central basin, in relation to natural sediments below, is visibly higher than 1.0 (2.0-19.0) whilst 40 K exhibits the opposite trend, and (c) the enrichment/dilution factor of radionuclides in the red-mud surficial veneer at the Antikyra Bay, in relation to the natural sediments below, is ranging between 0.4 and 3.5. (author)

  16. Interactions of tailings leachate with local liner materials found at Canonsburg, Pennsylvania

    International Nuclear Information System (INIS)

    Dodson, M.E.; Gee, G.W.; Serne, R.J.

    1984-04-01

    The mill tailings site at Canonsburg, Pennsylvania is the first mill site to receive remedial action under the Department of Energy's Uranium Mill Tailings Remedial Action Program. Part of this remedial action will require excavating the 53,500 m 3 (70,000 yd 3 ) of tailings on the site having a specific activity exceeding 100 pCi/g, and encapsulating these contaminated tailings in a clay-lined cell. As part of the remedial action effort, Pacific Northwest Laboratory has been studying the interactions of tailings and tailings leachate with locally occurring clays proposed for liner materials. These studies include physical and chemical characterization of amended and unamended local clays, chemical characterization of the tailings, column studies of tailings leached with deionized water, and column studies of clays contacted with tailings solutions to determine the attenuation properties of the proposed liner materials. Column studies of tailings leached with deionized water indicated that the Canonsburg tailings could represent a source of soluble radium-226 and uranium-238, several trace metals, cations, and the anions SO 4 , NO 3 , and Cl. Of these soluble contaminants, uranium-238, radium-226, the trace metals As and Mo, and the anions F and SO 4 were present at levels exceeding maximum concentration levels in the tailings leaching column effluents. However, local clays, both in amended and unamended form were effective in attenuating contaminant migration. The soil amendments tested failed to increase radium attenuation. The tailings leaching studies indicated that the tailings will produce leachates of neutral pH and relatively low contaminant levels for at least 200 years. We believe that compacting the tailings within the encapsulation cell will help to reduce leaching of contaminants from the liner system, since very low permeabilities ( -8 cm/s) were observed for even slightly compacted tailings materials

  17. Condition-dependence of Defensive Tail Displays in Common Garter Snakes (Thamnophis sirtalis)

    OpenAIRE

    Anderson, Sabrina Shay A.; Hudson, Spencer B.; Neuman-Lee, Lori; French, Susannah S.

    2017-01-01

    Individual snakes can exhibit a diversity of antipredator responses including crypsis, flight, and a variety of stereotyped behavioral reactions to predators at close range. Among these responses are behavioral differences in the movement (e.g., waving or wiggling) of a conspicuous tail by an otherwise cryptically colored snake. Defensive tail displays may disorient a predator, divert attack to the tail, act as a warning signal, or serve no function at all. The use of tail displays in snakes ...

  18. Graphite tail powder and liquid biofertilizer as trace elements source for ground nut

    Science.gov (United States)

    Hindersah, Reginawanti; Setiawati, M. Rochimi; Fitriatin, B. Natalie; Suryatama, Pujawati; Asmiran, Priyanka; Panatarani, Camellia; Joni, I. Made

    2018-02-01

    Utilization of graphite tail waste from the mineral beneficiation processing is very important since it contain significant amount of essential minerals which are necessary for plant growth. These mineral are required in biochemical processes and mainly play an important role as cofactor in enzymatic reaction. The objective of this research is to investigate the performance of graphite tail on supporting plant growth and yield of ground nut (Arachishypogeae L.). A field experiment has been performed to test the performance of mixed graphite tail and reduced organic matter dose. The graphite tail size were reduced to various sieved size, -80 mesh, -100 mesh and -200 mesh. The experiment was setup in randomized block design with 4 treatments and 6 replications for each treatment, while the control plot is received without graphite tail. The results demonstrated that reduced organic matter along with -200 mesh tail has potentially decreased plant height at the end of vegetative growth stage, in contrast for to -80 mesh tail amendment increased individual fresh plant biomass. Statistically, there was no change of plant nodule, individual shoot fresh and dry weight, root nodule, number of pod following any mesh of graphite tail amendment. Reducing organic matter while adding graphite tail of 5% did not change bean weight in all plot. In contrast, reduced organic matter along with 80-mesh graphite tail amendment improved the nut yield per plot. This experiment suggests that graphite tail, mainly -80 mesh graphite tail can be possibly used in legume production.

  19. Long-term ecological behaviour of abandoned uranium mill tailings. 1

    International Nuclear Information System (INIS)

    Kalin, M.

    1983-03-01

    Inactive uranium mill tailings were surveyed in the Province of Ontario to describe their surface characteristics, identify naturally invading biota, and determine essential chemical and physical parameters associated with the tailings. Inactive tailings sites can have wet areas, tailings completely covered with water, and dry areas. In the wet areas of most sites, wetland vegetation stands were found which were dominated by species of cattails (Typhaceae), along with some species of rushes (Juncaceae) and sedges (Cyperceae). Dry areas of the tailings exhibited a variety of surface features which are often a reflection of different amelioration efforts. Most of the indigenous species of vascular plants identified on dry areas of the tailings occurred only sporadically. Invading plants found on most sites were the tree species, trembling aspen (Populus tremuloides) and paper birch (Betula papyrifera). Elemental concentration and some physical characteristics of the tailings collected from a depth of 0-20 cm were determined. Uptake of heavy metals and radionuclides were evaluated in trees found in the dry areas and in cattails (Typha latifolia) in the wetland areas. Water bodies on tailings and surface water leaving the tailings, before and after treatment, were characterized in this survey. Aquatic bryophytes have invaded some water bodies on the tailings, and acid tolerant algae were evident in most of the water associated with the tailings. Ecological processes occurring on inactive uranium mill tailings which were identified in this survey are essential in evaluating the long-term fate of these waste sites

  20. The effect of flocculant on the geotechnical properties of mature fine tailings : An experimental study

    NARCIS (Netherlands)

    Yao, Y.; Van Tol, A.F.; Van Paassen, L.A.

    2012-01-01

    When oil sands tailings are deposited in a tailing pond, they settle and segregate to create a layer of stagnant water on top that is reused in oil extraction and a dense mixture of clay, silt and water on the bottom which is referred to as mature fine tailings (MFT). Dewatering of MFT is a problem

  1. The Pricing of Tail Risk and the Equity Premium: Evidence from International Option Markets

    DEFF Research Database (Denmark)

    Andersen, Torben Gustav; Fusari, Nicola; Todorov, Viktor

    We explore the pricing of tail risk as manifest in index options across international equity markets. The risk premium associated with negative tail events displays persistent shifts, unrelated to volatility. This tail risk premium is a potent predictor of future equity returns, while option......, suggesting a high degree of integration among the major global equity markets....

  2. On The Left Tail-End Probabilities and the Probability Generating ...

    African Journals Online (AJOL)

    On The Left Tail-End Probabilities and the Probability Generating Function. ... Journal of the Nigerian Association of Mathematical Physics ... In this paper, another tail-end probability function is proposed using the left tail-end probabilities, p( ≤ i ) = Πṙ The resulting function, πx(t), is continuous and converges uniformly ...

  3. Human born with a tail: A case report | Sarmast | South African ...

    African Journals Online (AJOL)

    Context. e dorsal cutaneous appendage, or so-called human tail, is often considered to be a cutaneous marker of underlying occult spinal dysraphism. Human tails have always elicited curiosity. A unique case of human dysraphism is described. Case report. An interesting case of a child with a tail-like caudal appendage ...

  4. Rope test may indicate efficacy of tail-biting treatments in growing pigs

    NARCIS (Netherlands)

    Bracke, M.B.M.

    2009-01-01

    Tail biting is a most serious welfare problem in pigs raised for slaughter. In instances of an outbreak of tail biting, scientists have recommended that farmers take measures such as removal of affected animals, provision of enrichment materials and application of repellents to the pigs' tails.

  5. The best of all worlds or the best possible world? Developmental constraint in the evolution of beta-tubulin and the sperm tail axoneme.

    Science.gov (United States)

    Nielsen, Mark G; Raff, Elizabeth C

    2002-01-01

    Through evolutionary history, some features of the phenotype show little variation. Stabilizing selection could produce this result, but the possibility also exists that a feature is conserved because it is developmentally constrained--only one or a few developmental mechanisms can produce that feature. We present experimental data documenting developmental constraint in the assembly of the motile sperm tail axoneme. The 9+2 microtubule architecture of the eukaryotic axoneme has been deeply conserved. We argue that the quality of motility supported by axonemes with this morphology explains their long conservation, rather than a developmental necessity for the 9+2 architecture. However, our functional tests in Drosophila spermatogenesis reveal considerable constraint in the coevolution of testis-specific beta-tubulin and the sperm tail axoneme. The evolution of testis beta-tubulins used in insect sperm tail axonemes is highly punctuated, indicating some pressure acting on their evolution. We provide a mechanistic explanation for their punctuated evolution by testing structure-function relationships between testis beta-tubulin and the motile axoneme in D. melanogaster. We discovered that a highly conserved sequence feature of beta-tubulins used in motile axonemes is needed to specify central pair formation. Second, our data suggest that cooperativity in the function of internal beta-tubulin amino acids is needed to support the long axonemes characteristic of Drosophila sperm tails. Thus, central pair formation constrains the evolution of the axoneme motif, and intramolecular cooperativity makes the evolution of the internal residues path dependent, which slows their evolution. Our results explain why a highly specialized beta-tubulin is needed to construct the Drosophila sperm tail axoneme. We conclude that these constraints have fixed testis-specific beta-tubulin identity in Drosophila.

  6. Circumstantial evidences for mimicry of scorpions by the neotropical gecko Coleodactylus brachystoma (Squamata, Gekkonidae in the Cerrados of central Brazil

    Directory of Open Access Journals (Sweden)

    Reuber Albuquerque Brandão

    2005-12-01

    Full Text Available There are few records of invertebrates mimicry by reptiles. In the Cerrados of central Brazil, the small Coleodactylus brachystoma is an endemic species common in the islands and margins of the Serra da Mesa hydroelectric dam reservoir. When cornered, this lizard folds the tail over the body exposing the pale-orange ventral surface. Lizard behavior, tail length and color pattern confer to this lizard a strong resemblance with syntopic buthid scorpions Rhopalurus agamenon, Tytius matogrossensis, and Anantheris balzani. Lizards and scorpions share the same tail color, size, and shape. Ecologically, they use the same microhabitats, are exposed to the same potential predators, and present similar behaviors when threatened.

  7. Microbial activities and communities in oil sands tailings ponds

    Energy Technology Data Exchange (ETDEWEB)

    Gieg, Lisa; Ramos, Esther; Clothier, Lindsay; Bordenave, Sylvain; Lin, Shiping; Voordouw, Gerrit; Dong, Xiaoli; Sensen, Christoph [University of Calgary (Canada)

    2011-07-01

    This paper discusses how the microbial communities and their activity play a vital role in tailings ponds. The ponds contain microorganisms along with metals, hydrocarbon diluent, naphthenic acid and others. The ponds play an important role in mining operations because they store bitumen extraction waste and also allow water to be re-used in the bitumen extraction process. Pond management presents a few challenges that include, among others, gas emissions and the presence of toxic and corrosive acids. Microbial activities and communities help in managing these ponds. Microbial activity measurement in active and inactive ponds is described and analyzed and the results are presented. The conditions for reducing sulfate, nitrate and iron are also presented. From the results it can be concluded that naphthenic acids can potentially serve as substrates for anaerobic populations in tailings ponds.

  8. Uranium Mill Tailings Remedial Action Project Vicinity Property Program

    International Nuclear Information System (INIS)

    Little, L.E.; Potter, R.F.; Arpke, P.W.

    1988-01-01

    The Department of Energy Uranium Mill Tailings Remedial Action (UMTRA) Grand Junction Project Vicinity Property Program is a $165 million program for the removal and disposal of uranium mill tailings that were used in the construction of approximately 4,000 residences, commercial buildings, and institutional facilities in the City of Grand Junction and surrounding Mesa County, Colorado. This paper discusses the UMTRA Vicinity Property Program and the economic benefits of this program for the City of Grand Junction and Mesa County, Colorado. The Bureau of Reclamation Economic Assessment Model (BREAM) was used to estimate the increases in employment and increases in personal income in Mesa County that result from the Vicinity Property Program. The effects of program-related changes in income and taxable expenditures on local and state tax revenue are also presented

  9. The Monticello, Utah, uranium mill tailings site: A case history

    International Nuclear Information System (INIS)

    Korte, N.E.; Kearl, P.M.; Sewell, J.M.; Fleischhauer, H.L.; Abramiuk, I.N.

    1984-01-01

    A multidisciplinary study was conducted to characterize the potential for contamination from the inactive millsite in Monticello, Utah. Emphasis was given to site geology, hydrology, and geochemistry for two reasons: (1) a perennial stream flows through the tailings area, and (2) a culinary aquifer is overlain by an alluvial aquifer contaminated by the tailings area. Study results indicate that surface-water contamination attributable to the piles exists for approximately 6 km downstream from the site. Contamination also exists in the alluvial aquifer underlying the millsite. Hydrologic studies indicate an active alluvial system, with recharge to the gravels by infiltration through the trailings. Fortunately, water-level and water-quality data, together with the results of a 51-hour pump test, indicate that the Dakota Formation is an effective aquitard, restricting the downward movement of contaminated water to the underlying culinary aquifer

  10. Uranium Mill Tailings Remedial Action Project 1993 Environmental Report

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    This annual report documents the Uranium Mill Tailing Remedial Action (UMTRA) Project environmental monitoring and protection program. The UMTRA Project routinely monitors radiation, radioactive residual materials, and hazardous constituents at associated former uranium tailings processing sites and disposal sites. At the end of 1993, surface remedial action was complete at 10 of the 24 designated UMTRA Project processing sites. In 1993 the UMTRA Project office revised the UMTRA Project Environmental Protection Implementation Plan, as required by the US DOE. Because the UMTRA Project sites are in different stages of remedial action, the breadth of the UMTRA environmental protection program differs from site to site. In general, sites actively undergoing surface remedial action have the most comprehensive environmental programs for sampling media. At sites where surface remedial action is complete and at sites where remedial action has not yet begun, the environmental program consists primarily of surface water and ground water monitoring to support site characterization, baseline risk assessments, or disposal site performance assessments.

  11. Electrodialytic remediation of copper mine tailings: Comparing different operational conditions

    DEFF Research Database (Denmark)

    Rojo, Adrian; Hansen, Henrik K.; Ottosen, Lisbeth M.

    2006-01-01

    This work compares and evaluates sixteen electrodialytic laboratory remediation experiments on copper mine tailings. Different parameters were analyzed, such as remediation time, voltage drop, addition of desorbing agents, and the use of pulsed electrical fields. The results show that electric...... of copper citrate complexes. Using pulsed electric fields the remediation process with sulphuric acid addition was also improved by a decrease in the polarization cell. Main results: considering remediation with watery tailing as the base line, for three weeks experiments no copper removal was observed......, adding sulphuric acid total copper removal reached 39%. Adding citric acid, total copper removal was improved in terms of remediation time: after 5h experiment copper removal was 16% instead of 9% obtained after 72h with sulphuric acid addition. Using pulsed electric fields total copper removal was also...

  12. Long-time tails of correlation and memory functions

    Science.gov (United States)

    Sawada, Isao

    2002-11-01

    We review the generalized Langevin equation, which is a transformation and reformulation of equation of motion, from the two viewpoints: the projection operator method developed by Mori and the recurrence relations method developed by Lee. The fluctuating forces acting on the Bloch electrons’ current are clarified the strongly colored quantum fluctuations with the spontaneous interband transitions leading to a long-time tail of 1/ t for the envelope of the memory function. The velocity autocorrelation functions in the coupled harmonic oscillator on the Bethe lattice have a long-time tail of 1/t t. The oscillation and the form of decay found in correlation functions affect transport coefficients given by the integrated intensity up to infinity. We also study the force-force correlation functions often used as an approximation to the memory function.

  13. A dataset on tail risk of commodities markets.

    Science.gov (United States)

    Powell, Robert J; Vo, Duc H; Pham, Thach N; Singh, Abhay K

    2017-12-01

    This article contains the datasets related to the research article "The long and short of commodity tails and their relationship to Asian equity markets"(Powell et al., 2017) [1]. The datasets contain the daily prices (and price movements) of 24 different commodities decomposed from the S&P GSCI index and the daily prices (and price movements) of three share market indices including World, Asia, and South East Asia for the period 2004-2015. Then, the dataset is divided into annual periods, showing the worst 5% of price movements for each year. The datasets are convenient to examine the tail risk of different commodities as measured by Conditional Value at Risk (CVaR) as well as their changes over periods. The datasets can also be used to investigate the association between commodity markets and share markets.

  14. A generic model of contaminant migration from uranium tailings impoundments

    International Nuclear Information System (INIS)

    Shepherd, T.A.; Brown, S.E.

    1982-01-01

    This paper presents an analytical hydrogeochemical model based upon acid consumption-neutralization front movement. The development of contaminant plumes is discussed and distinct zones within these plumes are identified and characterized. The most important process influencing the rate and extent of contaminant migration at acid-leach uranium tailings impoundments is the neutralization of seepage water by soils along ground water flow paths. The chemical characteristics of the ground water is determined in order to identify and characterize zones within migrating plumes of tailings-derived water. It is concluded that the characterization of specific zones is useful in the interpretation of existing conditions, in the evaluation of future migration, and in the determination of appropriate models for the specific situation

  15. Selective export of HLA-F by its cytoplasmic tail.

    Science.gov (United States)

    Boyle, Louise H; Gillingham, Alison K; Munro, Sean; Trowsdale, John

    2006-06-01

    MHC class I molecules exit the endoplasmic reticulum (ER) by an unknown mechanism. Although a selective export mechanism has been proposed for the anterograde transport of class I, a motif responsible for export has never been identified. Although classical class I molecules lacking their cytoplasmic tail are expressed on the cell surface, we found that HLA-F was entirely dependent on its cytoplasmic tail for export from the ER. Two known export motifs were recognizable in HLA-F. A C-terminal valine residue functioned in ER export and interacted with coat complex (COP)II, while an RxR motif also played an important role in anterograde transport and bound to 14-3-3 proteins. This divergent trafficking of HLA-F implicates an alternative function for HLA-F, independent of loading with peptides in the ER.

  16. Global simulation of the magnetosphere with a long tail

    International Nuclear Information System (INIS)

    Kageyama, A.; Watanabe, K.; Sato, T.

    1990-09-01

    A global simulation of the formation of the magnetosphere with along tail is performed. A magnetosphere with a neutral sheet is constructed from a dipole field by solar wind dynamic pressure (no IMF). Subsequently, magnetic reconnection occurs in the plasma sheet and a large lump of plasma surrounded by reconnected field lines, a plasmoid, is formed and ejected tailward. The time scale of the plasmoid formation and ejection process is several hours. After ejecting the plasmoid, reconnection occurs again in the plasma sheet and the second plasmoid is formed and ejected. This result shows that the magnetosphere which has a sufficiently long tail and a neutral sheet is slightly unstable even though a solar wind does not contain an IMF. (author)

  17. ISAL experiment documentation of vertical tail and OMS pods

    Science.gov (United States)

    1983-01-01

    Investigation of Space Transportation System (STS) Atmospheric Luminosities (ISAL) experiment documentation includes vertical tail and orbital maneuvering system (OMS) pods with surface glow against the blackness of space. This glowing scene was provided by a long duration exposure with a 35mm camera aimed toward the tail of the Earth-orbiting Challenger, Orbiter Vehicle (OV) 099. OV-099 was maneuvered to a 120-nautical-mile altitude and flown with open payload bay (PLB) in the velocity vector for the conducting of a test titled, 'Evaluation of Oxygen Interaction with Materials (EOIM)'. Atomic oxygen within the low orbital environment is known to be extremely reactive when in contact with solid surfaces. In the darkened area between the camera and the glowing OMS pods and vertical stabilizer are two trays of test materials.

  18. The heads and tails of buoyant autocatalytic balls

    Science.gov (United States)

    Rogers, Michael C.; Morris, Stephen W.

    2012-09-01

    Buoyancy produced by autocatalytic reaction fronts can produce fluid flows that advect the front position, giving rise to interesting feedback between chemical and hydrodynamic effects. In this paper, we numerically investigate the evolution of autocatalytic iodate-arsenous acid reaction fronts initialized in spherical configurations. Deformation of these "autocatalytic balls" is driven by buoyancy produced by the reaction. In our simulations, we have found that depending on the initial ball radius, the reaction front will develop in one of three different ways. In an intermediate range of ball size, the flow can evolve much like an autocatalytic plume: the ball develops a reacting head and tail that is akin to the head and conduit of an autocatalytic plume. In the limit of large autocatalytic balls, however, growth of a reacting tail is suppressed and the resemblance to plumes disappears. Conversely, very small balls of product solution fail to initiate sustained fronts and eventually disappear.

  19. Empirical Estimates in Stochastic Optimization via Distribution Tails

    Czech Academy of Sciences Publication Activity Database

    Kaňková, Vlasta

    2010-01-01

    Roč. 46, č. 3 (2010), s. 459-471 ISSN 0023-5954. [International Conference on Mathematical Methods in Economy and Industry. České Budějovice, 15.06.2009-18.06.2009] R&D Projects: GA ČR GA402/07/1113; GA ČR(CZ) GA402/08/0107; GA MŠk(CZ) LC06075 Institutional research plan: CEZ:AV0Z10750506 Keywords : Stochastic programming problems * Stability * Wasserstein metric * L_1 norm * Lipschitz property * Empirical estimates * Convergence rate * Exponential tails * Heavy tails * Pareto distribution * Risk functional * Empirical quantiles Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.461, year: 2010

  20. Spontaneous meningioma in a pig-tailed macaque (Macaca nemestrina

    Directory of Open Access Journals (Sweden)

    R. Plesker

    2018-04-01

    Full Text Available We present a case of spontaneous meningioma in a female pig-tailed macaque (Macaca nemestrina more than 24 years old. Clinically, the monkey displayed slow, weak, and insecure movements and poor vision. A tumorous mass was present at the floor of the cranial vault extending from the optic chiasm towards the foramen magnum. It compressed adjacent parts of the brain, infiltrated the sphenoidal and occipital bone, and showed transcranial expansion into the pharyngeal area. Histologically, the tumor was consistent with a meningioma displaying mostly meningothelial and some microcystic components. Since only six cases of meningiomas in nonhuman primates have been reported so far and only two of these meningiomas have been described in detail, the findings of each case should be reported to expand the knowledge base of this type of tumor. In addition, this is the first description of a meningioma in pig-tailed macaques.

  1. Ring-tailed lemurs: a species re-imagined.

    Science.gov (United States)

    Sauther, Michelle L; Gould, Lisa; Cuozzo, Frank P; O'Mara, M Teague

    2015-01-01

    For over 50 years, ring-tailed lemurs have been studied continuously in the wild. As one of the most long-studied primate species, the length and breadth of their study is comparable to research on Japanese macaques, baboons and chimpanzees. They are also one of the most broadly observed of all primates, with comprehensive research conducted on their behaviour, biology, ecology, genetics, palaeobiology and life history. However, over the last decade, a new generation of lemur scholars, working in conjunction with researchers who have spent decades studying this species, have greatly enhanced our knowledge of ring-tailed lemurs. In addition, research on this species has expanded beyond traditional gallery forest habitats to now include high altitude, spiny thicket, rocky outcrop and anthropogenically disturbed coastal forest populations. The focus of this special volume is to 're-imagine' the 'flagship species of Madagascar', bringing together three generations of lemur scholars. © 2015 S. Karger AG, Basel.

  2. ''Tailed'' nuclei are a possible cell marker of radiational effects

    International Nuclear Information System (INIS)

    Kravtsov, V.Yu.; Starkova, E.V.; Nikiforov, A.M.; Fedortseva, R.F.; Loginova, Yu.A.; Yakovlev, A.F.

    1997-01-01

    Study of peripheral blood smears from irradiated patients (liquidators of consequences of the Chernobyl Atomic Electric Plant accident) has shown nuclei of some lymphocytes to have a protrusion into the cytoplasm. Such abnormal nuclei are called ''tailed'' nuclei (TN). The mean frequency of appearance of lymphocytes with TN in the group of irradiated patients (n=136) amounted to 0.59%, whereas in the group of healthy donors (n=50), 0.15% (the difference between the groups is statistically significant). The correlation coefficient between the indicators ''frequency of lymphocytes with NT'' and ''frequency of lymphocytes with dicentric chromosomes'' was 0.73 (n=47, p<0.001). By the method of bicolour FISH there was revealed localization of the near-centromere (not more than two signals) and telomere (not more than one signal) regions in the nuclear ''tails''. Abnormalities of the TN type in lymphocytes are likely to result from breakdowns of chromosomal bridges formed by dicentric chromosomes. (author)

  3. Uranium Mill Tailings Remedial Action Project 1993 Environmental Report

    International Nuclear Information System (INIS)

    1994-10-01

    This annual report documents the Uranium Mill Tailing Remedial Action (UMTRA) Project environmental monitoring and protection program. The UMTRA Project routinely monitors radiation, radioactive residual materials, and hazardous constituents at associated former uranium tailings processing sites and disposal sites. At the end of 1993, surface remedial action was complete at 10 of the 24 designated UMTRA Project processing sites. In 1993 the UMTRA Project office revised the UMTRA Project Environmental Protection Implementation Plan, as required by the US DOE. Because the UMTRA Project sites are in different stages of remedial action, the breadth of the UMTRA environmental protection program differs from site to site. In general, sites actively undergoing surface remedial action have the most comprehensive environmental programs for sampling media. At sites where surface remedial action is complete and at sites where remedial action has not yet begun, the environmental program consists primarily of surface water and ground water monitoring to support site characterization, baseline risk assessments, or disposal site performance assessments

  4. A new trajectory concept for exploring the earth's geomagnetic tail

    Science.gov (United States)

    Farquhar, R. W.; Dunham, D. W.

    1981-01-01

    An innovative trajectory technique for a magnetotail mapping mission is described which can control the apsidal rotation of an elliptical earth orbit and keep its apogee segment inside the tail region. The required apsidal rotation rate of approximately 1 deg/day is achieved by using the moon to carry out a prescribed sequence of gravity-assist maneuvers. Apogee distances are alternately raised and lowered by the lunar-swingby maneuvers; several categories of the 'sun-synchronous' swingby trajectories are identified. The strength and flexibility of the new trajectory concept is demonstrated by using real-world simulations showing that a large variety of trajectory shapes can be used to explore the earth's geomagnetic tail between 60 and 250 R sub E.

  5. Comparison of the breeding biology of sympatric red-tailed Hawks, White-tailed Hawks, and Crested Caracaras in south Texas

    Science.gov (United States)

    Actkinson, M.A.; Kuvlesky, W.P.; Boal, C.W.; Brennan, L.A.; Hernandez, F.

    2009-01-01

    We compared the breeding biology of sympatric nesting Red-tailed Hawks (Buteo jamaicensis), White-tailed Hawks (Buteo albicaudatus), and Crested Caracaras (Caracara cheriway) in south Texas during 2003 and 2004. We monitored 46 breeding attempts by Red-tailed Hawks, 56 by White-tailed Hawks, and 27 by Crested Caracaras. Observed nesting success was similar for Red-tailed Hawks (62%) and Crested Caracaras (61%), but lower for White-tailed Hawks (51%). Daily survival rates (0.99) were the same for all three species. Red-tailed Hawks and White-tailed Hawks both fledged 1.13 young per nesting pair and Crested Caracaras fledged 1.39 young per nesting pair. All three species nested earlier in 2004 than in 2003; in addition, the overall nesting density of these three species almost doubled from 2003 (1.45 pairs/km2) to 2004 (2.71 pairs/km2). Estimated productivity of all three species was within the ranges reported from other studies. Given extensive and progressive habitat alteration in some areas of south Texas, and the limited distributions of White-tailed Hawks and Crested Caracaras, the presence of large ranches managed for free-range cattle production and hunting leases likely provides important habitat and may be key areas for conservation of these two species. ?? 2009 The Raptor Research Foundation, Inc.

  6. Comparative Study of Transcriptome Profiles of Mouse Livers and Skins Infected by Fork-Tailed or Non-Fork-Tailed Schistosoma japonicum

    Directory of Open Access Journals (Sweden)

    Yan Yang

    2017-08-01

    Full Text Available Schistosoma japonicum (S. japonicum is a worldwide spread pathogen which penetrates host skin and then induces several diseases in infected host, such as fibrosis, formation of granulomas, hepatocirrhosis, and hepatomegaly. In present study, for the first time, transcriptomic profiles of mouse livers and skins infected by fork-tailed S. japonicum cercaria or non-fork-tailed S. japonicum cercaria were analyzed by using RNA-seq. The present findings demonstrated that transcriptomic landscapes of livers and skins infected by fork-tailed S. japonicum cercaria or non-fork-tailed S. japonicum cercaria were different. S. japonicum has great influence on hepatic metabolic processes. Fork-tailed S. japonicum cercaria upregulated hepatic metabolic processes, while non-fork-tailed S. japonicum cercaria downregulated hepatic metabolic processes. For the metabolism process or the metabolism enzyme expressional change, the pharmacokinetics of host could be changed during S. japonicum infection, regardless the biotypes of S. japonicum cercariae. The changes of infected skins focused on upregulation of immune response. During the S. japonicum skin infection period, fork-tailed S. japonicum cercaria infection induced stronger immune response comparing with that immune response triggered by non-fork-tailed S. japonicum cercaria. The transcription factor enrichment analysis showed that Irf7, Stat1 and Stat2 could play important roles in gene regulation during fork-tailed S. japonicum cercaria infection.

  7. Small Sample Robust Testing for Normality against Pareto Tails

    Czech Academy of Sciences Publication Activity Database

    Stehlík, M.; Fabián, Zdeněk; Střelec, L.

    2012-01-01

    Roč. 41, č. 7 (2012), s. 1167-1194 ISSN 0361-0918 Grant - others:Aktion(CZ-AT) 51p7, 54p21, 50p14, 54p13 Institutional research plan: CEZ:AV0Z10300504 Keywords : consistency * Hill estimator * t-Hill estimator * location functional * Pareto tail * power comparison * returns * robust tests for normality Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.295, year: 2012

  8. Hypothesis Testing Using Spatially Dependent Heavy Tailed Multisensor Data

    Science.gov (United States)

    2014-12-01

    of improper models, where tail-dependence was inadequately quantified, was considered to be one of the causes for the financial crisis of 2007-2008... disciplines such as machine learning, information theory, speech processing, finance, and aerospace, among others, has led to a rich body of...vol. 10, no. 7, pp. 215–218, Jul. 2003. [24] P. D. Ditlevsen, “Observation of ↵-stable noise induced millennial climate changes from an ice-core record

  9. Uranium Mill Tailings Remedial Action Program. Annual status report

    International Nuclear Information System (INIS)

    1983-12-01

    The FY 1983 project accomplishments are: completed the Remedial Action Plan and Phase I engineering design for the Canonsburg processing site; completed remedial action on an additional 52 vicinity properties and the inclusion of an additional 303 properties in the Uranium Mill Tailings Remedial Action Project; executed cooperative agreements with four states and the Navajo Nation; published the draft environmental impact statement for Salt Lake City site; and issued the approved Project Plan

  10. Molecular analysis of the bacterial diversity in uranium mill tailings

    International Nuclear Information System (INIS)

    Geissler, A.

    2003-04-01

    A culture-independent molecular approach has been applied to investigate the bacterial diversity in three uranium contaminated sites. The three analysed soil samples have been collected from the uranium waste pile Haberland near Johanngeorgenstadt (Germany), from the uranium mill tailings in Gunnison, Colorado (USA) and from the uranium mill tailings in Shiprock, New Mexico (USA). The 16S rDNA fragments which has been isolated through direct lysis of the whole-DNA were amplified by the use of the universal primers 16S 43f and 16S 1404r and cloned. With restriction fragment length polymorphismus (RFLP) were the clones screened and one representative of all RFLP types that occurred more than once in the clone library was sequenced and analysed. In spite of the contamination a considerable diversity and significant differences in the composition of the natural bacterial communities in these three sites have been found. In the sample collected from the waste pile Haberland near Johanngeorgenstadt α-Proteobacteria and representatives of the Holophaga/Acidobacterium were numerically predominant. The distribution of bacteria in the sample collected from uranium mill tailings Gunnison was very similar to those found in the Haberland waste pile, but there were found besides α-Proteobacteria and representatives of Holophaga/Acidobacterium a lot of γ-Proteobacteria. The structure of the bacterial community in the sample collected from the uranium mill tailings Shiprock was significantly different. Only some representatives of the Holophaga/Acidobacterium and α-Proteobacteria were represented. Large populations of Bacilli, γ-Proteobacteria and green non sulfur bacteria were dominant in this sample. (orig.)

  11. Characterization and treatment of artisanal gold mine tailings

    International Nuclear Information System (INIS)

    Andrade Lima, L.R.P. de; Bernardez, L.A.; Barbosa, L.A.D.

    2008-01-01

    The solid waste generated by artisanal gold mining, with high mercury and gold contents, can be found in several areas in the South America. The present study focused on the tailings of an artisanal gold mine area located in the Brazilian northeastern. Samples of the mine tailings were taken and used to perform a physical and chemical characterization study using X-ray diffraction, scanning electron microscopy, neutron activation, X-ray fluorescence, induced coupled plasma-mass spectrometry, among others analytical methods. The results indicate that the material is composed mainly by quartz and goethite, the characteristic size of the particles (d 50 ) is about 150 μm, and the density is close of that of quartz. The main constituents are silicon, iron, and aluminum. The tailings gold content is of about 1.8 mg/kg and the mercury content is of about 10 mg/kg. A remarkable feature of this solid waste is that the gold and mercury are both concentrated in both the fine and the coarse particles, but not in particles of intermediary size. Leaching studies indicated that the tailings are stable in weak organic acids, but soluble in alkaline and aired cyanide solutions, in which 89% of gold and 100% of mercury are extracted in 24 h. Electroleaching experiments, performed using sodium chloride as electrolyte, indicated that mercury and gold are extracted simultaneously and the recovery of both metals can be as high as 70% in 4 h. In addition, chromium, nickel, and lead are found in relatively large amounts in the solution, which indicate an effectively action of the electroleaching method to clean up solid wastes contaminated with metals

  12. Program plan for the National Uranium Mine Tailings Office

    International Nuclear Information System (INIS)

    1983-03-01

    The National Uranium Mine Tailings Program was formed to conduct research into the long-term environmental behaviour of uranium mine tailings. This research is necessary to provide a data base upon which close-cut criteria for uranium mines can be based. The research program to be carried out under the auspices of the National Tailings Program Office has, as its goal, the development of this data base, and the formulation of a series of reports based on that data base. These documents are to be designed to allow the uranium mining industry to produce site-specific close-out plans which will be acceptable to the regulatory authorities. This report addresses the program to be undertaken to meet the above broad objective. It focusses on defining in more specific and explicit terms what the program objectives need to be to meet the close-out requirements currently perceived by the regulatory agencies involved. These program objectives have been refined and summarized as follows: On close-out, the tailings site shall: 1. Meet currently accepted individual exposure criteria, and meet air and water quality regulations. 2. Ensure a predictable decline in release rates of contaminants to the environment. Ideally, this decline would be monotonic in nature. 3. Meet the ALARA principle both at present and into the long-term future. 4. Ensure that the management strategy or technologies employed in close-out shall be of a passive nature and not require ongoing institutional intervention. On the basis of these program objectives, this report identifies specific program product in terms of manuals of practice, guidelines, etc. that are to be produced as a result of program activity. These documents will effectively provide guidance on acceptable close-out technology to the uranium industry and regulatory agencies

  13. Uranium mill tailings remedial action project real estate management plan

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    This plan summarizes the real estate requirements of the US Department of Energy`s (DOE) Uranium Mill Tailings Action (UMTRA) Project, identifies the roles and responsibilities of project participants involved in real estate activities, and describes the approaches used for completing these requirements. This document is intended to serve as a practical guide for all project participants. It is intended to be consistent with all formal agreements, but if a conflict is identified, the formal agreements will take precedence.

  14. Tailings dams safety - implications for the dam safety community

    International Nuclear Information System (INIS)

    Vick, S.G.

    1999-01-01

    In the context of the impact of privatization and globalization on traditional dam safety practice and the Canadian experience of the environmental dimension of dam failures, various aspects of tailings dam safety have much to offer the wider dam safety community. General design principles for tailings dams are not described, rather an attempt is made to frame some contemporary issues of tailings dam safety in ways that bring out their relevance in a broader dam safety context. Lessons applicable to future dam safety practice in related areas are examined, and the dam safety traditions of the mining, hydroelectric and related industries in Canada are brought together by illustrating some of the common elements and concerns they share. It is becoming evident that future dam safety activities for the hydroelectric, water supply and related dams will be carried out in a more privatized and globalized context by organizations less acquainted with traditional dam safety practices than in the past. If so, then tailings dam experience can be a pathfinder for how and why dam safety needs to be addressed in a corporate setting. It shows that the perceived effects of dam failures, environmental and otherwise, influence corporate damowners in ways that can amplify manyfold the objective consequences that dam safety assessments usually address. Dam safety professionals might do well to better understand and effectively communicate the financial and organizational impacts of dam failure on the corporate entity in ways that go beyond the traditional assessment of downstream hazard and failure consequences. Dam safety efforts can come to be seen less as imposed burdens of dam ownership and more as activities consistent with shareholder accountability and corporate self-interest. The Canadian mining industry, in adopting this perspective, is confirming that support for dam safety activities from the highest corporate level is essential for implementing them throughout the

  15. On Hurst exponent estimation under heavy-tailed distributions

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Krištoufek, Ladislav

    2010-01-01

    Roč. 389, č. 18 (2010), s. 3844-3855 ISSN 0378-4371 R&D Projects: GA ČR GA402/09/0965 Grant - others:GA UK(CZ) 118310; GA UK(CZ) 46108 Institutional research plan: CEZ:AV0Z10750506 Keywords : high frequency data analysis * heavy tails * Hurst exponent Subject RIV: AH - Economics Impact factor: 1.521, year: 2010 http://library.utia.cas.cz/separaty/2010/E/barunik-0343525.pdf

  16. Power-law cross-correlations estimation under heavy tails

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav

    2016-01-01

    Roč. 40, č. 1 (2016), s. 163-172 ISSN 1007-5704 R&D Projects: GA ČR(CZ) GP14-11402P Institutional support: RVO:67985556 Keywords : Power-law cross-correlations * Heavy tails * Monte Carlo study Subject RIV: AH - Economics Impact factor: 2.784, year: 2016 http://library.utia.cas.cz/separaty/2016/E/kristoufek-0472030.pdf

  17. Uranium mill tailings remedial action project real estate management plan

    International Nuclear Information System (INIS)

    1994-09-01

    This plan summarizes the real estate requirements of the US Department of Energy's (DOE) Uranium Mill Tailings Action (UMTRA) Project, identifies the roles and responsibilities of project participants involved in real estate activities, and describes the approaches used for completing these requirements. This document is intended to serve as a practical guide for all project participants. It is intended to be consistent with all formal agreements, but if a conflict is identified, the formal agreements will take precedence

  18. Biological treatment options for consolidated tailings release waters

    Energy Technology Data Exchange (ETDEWEB)

    Gunter, C.P.; Nix, P.G.; Sander, B. [EVS Environment Consultants, North Vancouver, British Columbia (Canada); Knezevic, Z.

    1995-12-31

    Suncor Inc., Oil Sands Group, operates a large oil sands mining and extraction operation in northeastern Alberta. The extraction plant produces large volumes of a tailings slurry which resists dewatering and treatment, and is toxic to aquatic organisms. Consolidated tailings (CT) technology is used to treat tailings by either acid/lime or gypsum and enhances the possibility of treating residual fine tails in a ``dry`` land reclamation scenario and treating the release water in a wastewater treatment reclamation scenario. The objective was to assess the treatability of CT release water (i.e., the reduction of acute and chronic toxicities to trout, Ceriodaphnia, and bacteria) in bench-scale biological treatment systems. Microtox{reg_sign} IC20 test showed complete detoxification for the gypsum CT release water within 3 to 5 weeks compared with little reduction in toxicity for dyke drainage. Acute toxicity (fish) and chronic toxicity (Ceriodaphnia, bacterial) was removed from both CT release waters. Phosphate and aeration enhanced detoxification rates. Concentrations of naphthenic acids (an organic toxicant) were not reduced, but levels of dissolved organic compounds decreased faster than was the case for dyke drainage water, indicating that some of the organic compounds in both acid/lime and gypsum CT waters were more biodegradable. There was a pattern of increasing toxicity for dyke drainage water which confirmed observations during field-scale testing in the constructed wetlands and which was not observed for CT release waters. Acid/lime and gypsum CT water can be treated biologically in either an aeration pond, constructed wetlands, or a combination of both thereby avoiding the expense of long-term storage and/or conventional waste treatment systems.

  19. Dynamical and photometric models of star formation in tidal tails

    International Nuclear Information System (INIS)

    Wallin, J.F.

    1990-01-01

    An investigation into the causes of star formation in tidal tails has been conducted using a restricted three-body dynamical model in conjunction with a broadband photometric evolutionary code. Test particles are initially placed in circular orbits around a softened point mass and then perturbed by a companion passing in a parabotic orbit. During the passage, the density evolution of the galaxy is examined both in regions within the disk and in selected comoving regions in the tidal features. Even without the inclusion of self-gravity and hydrodynamics, regions of compression form inside the disk, along the tidal tail, and in the tidal bridge causing local density increases of up to 500 percent. By assuming that the density changes relate to the star-formation rate via a Schmidt (1959) law, limits on the density changes needed to make detectable changes in the colors are calculated. A spiral galaxy population is synthesized and the effects of modest changes in the star-formation rate are explored using a broadband photometric evolutionary code. Density changes similar to those found in the dynamical models will cause detectable changes in the colors of a stellar population. From these models, it is determined that the blue colors and knotty features observed in the tidal features of some galaxies result from increased rates of star formation induced by tidally produced density increases. Limitations of this model are discussed along with photometric evolutionary models based on the density evolution in the tails. 52 refs

  20. Disposal of iron tailings in reservoirs: a GPR application

    Directory of Open Access Journals (Sweden)

    Rachel Jardim Martini

    2016-11-01

    Full Text Available A large volume of waste is generated by iron mining in Brazil, and the amount has been rapidly increasing. The waste is usually stored in large piles or in reservoirs formed by tailings dams, which occupy large areas in the mining complex. The limitation of natural resources and of new areas for waste disposal has led to change in paradigms. This study therefore aimed to apply a geophysical technique, known as Ground Penetrating Radar (GPR, in order to define sedimentation patterns in the subsurface reservoir created by Diogo's tailings dam in Rio Piracicaba in Minas Gerais, Brazil. To assist the recognition of patterns captured by the GPR, subsurface material samples were collected and analyzed for mineralogical composition, moisture content, electrical conductivity, mineralogical analysis, particle size, X-Ray Diffraction and X-Ray Fluorescence. The results indicated that areas with tailings that had high concentrations of hematite (around 60% in the mineralogical analysis altered the reflection patterns. The presence of water generated some multiple reflections, which were less significant in shallower sites with more waste and more significant in deeper sites with less waste. In general, the application of the GPR was feasible in aquatic environments with rich subsurface hematite deposits.

  1. Tailings From Mining Activities, Impact on Groundwater, and Remediation

    Directory of Open Access Journals (Sweden)

    Khalid Al-Rawahy

    2001-12-01

    Full Text Available Effluent wastes from mining operations and beneficiation processes are comprized mostly of the following pollutants: total suspended solids (TTS, alkalinity or acidity (pH, settleable solids, iron in ferrous mining, and dissolved metals in nonferrous mining. Suspended solids consist of small particles of solid pollutants that resist separation by conventional means. A number of dissolved metals are considered toxic pollutants. The major metal pollutants present in ore mining and beneficiation waste waters include arsenic, cadmium, copper, lead, mercury, nickel, and zinc. Tailings ponds are used for both the disposal of solid waste and the treatment of waste-water streams. The supernatant decanted from these ponds contains suspended solids and, at times, process reagents introduced to the water during ore beneficiation. Leakage of material from tailings pond into groundwater is one possible source of water pollution in the mining industry. Percolation of waste-water from impoundment may occur if tailings ponds are not properly designed. This paper addresses potential groundwater pollution due to effluent from mining activities, and the possible remediation options.

  2. Optimal heavy tail estimation - Part 1: Order selection

    Science.gov (United States)

    Mudelsee, Manfred; Bermejo, Miguel A.

    2017-12-01

    The tail probability, P, of the distribution of a variable is important for risk analysis of extremes. Many variables in complex geophysical systems show heavy tails, where P decreases with the value, x, of a variable as a power law with a characteristic exponent, α. Accurate estimation of α on the basis of data is currently hindered by the problem of the selection of the order, that is, the number of largest x values to utilize for the estimation. This paper presents a new, widely applicable, data-adaptive order selector, which is based on computer simulations and brute force search. It is the first in a set of papers on optimal heavy tail estimation. The new selector outperforms competitors in a Monte Carlo experiment, where simulated data are generated from stable distributions and AR(1) serial dependence. We calculate error bars for the estimated α by means of simulations. We illustrate the method on an artificial time series. We apply it to an observed, hydrological time series from the River Elbe and find an estimated characteristic exponent of 1.48 ± 0.13. This result indicates finite mean but infinite variance of the statistical distribution of river runoff.

  3. Atmospheric pressure plasma accelerates tail regeneration in tadpoles Xenopus laevis

    Science.gov (United States)

    Rivie, A.; Martus, K.; Menon, J.

    2017-08-01

    Atmospheric pressure plasma is a partially ionized gas composed of neutral and charged particles, including electrons and ions, as well as reactive oxygen species (ROS). Recently, it is utilized as possible therapy in oncology, sterilization, skin diseases, wound healing and tissue regeneration. In this study we focused on effect of plasma exposure on tail regeneration of tadpoles, Xenopus leavis with special emphasis on role of ROS, antioxidant defenses and morphological features of the regenerate. When amputated region of the tail was exposed to the helium plasma it resulted in a faster rate of growth, elevated ROS and increase in antioxidant enzymes in the regenerate compared to that of untreated control. An increase in nitric oxide (free radical) as well as activity of nitric oxide synthase(s) were observed once the cells of the regeneration blastema - a mass of proliferating cells are ready for differentiation. Microscopically the cells of the regenerate of plasma treated tadpoles show altered morphology and characteristics of cellular hypoxia and oxidative stress. We summarize that plasma exposure accelerates the dynamics of wound healing and tail regeneration through its effects on cell proliferation and differentiation as well as angiogenesis mediated through ROS signaling.

  4. Long-term disposal of enrichment plant tails

    International Nuclear Information System (INIS)

    1979-08-01

    Approximately 97% of the uranium fed to the isotope separation plants is recovered as tails containing nominally 0.2 wt percent U-235. Essentially all this tails material produced in the past, as well as that currently being generated, is stored as solidified UF 6 in steel cylinders. This report describes a stand-alone, 10 tU/day facility for converting the UF 6 to a stable uranium oxide powder amenable to long-term storage in steel drums. The conversion is accomplished in a two-step process in which the UF 6 is first reduced to UF 4 with hydrogen in a tower reactor and then the UF 4 is pyrohydrolyzed to UO 2 with steam in a three-stage screw reactor. One reduction reactor supplies the feed for three pyrohydrolysis reactor lines. Included in the process flow sheets and reactor design details are descriptions of the major auxiliary components for vaporizing and feeding the UF 6 , a dissociator for ammonia used as a hydrogen source, a system for recovering anhydrous hydrogen fluoride, and a reactor system for the disposal of hydrous hydrogen fluoride. Two of the nominal 10 tU/day plants would be required to handle the tails produced in isotope separation plants supplying enriched uranium to a nuclear power industry with a generation capacity of 50 GWe per year

  5. Tail production and removal. Risk, challenges and possibilities

    International Nuclear Information System (INIS)

    Magelssen, Hans Chr.

    1997-01-01

    Elf is one of the companies with the longest experience as an oil operator in Norway. This presentation discusses experiences made by Elf on tail production and removal. It starts with a description of risk, economic analyses and individual cash flow discounting and then deals with the challenges and possibilities of extended use of existing installations. Elf does not use individual cash flow discounting, which has several disadvantages, but rather traditional indicators like NPV (Net Present Value), IRR (Internal Rate of Return), payback time and balance price calculated by means of cash flow, as well as a type of ROI (Return On Investment). In normal present value calculation, the decision-maker estimates the total risk for the project and compare this with a relevant present value. Another method is proposed if it is desirable to include risk directly in calculating the present value. In this method the present value is shown as a probability distribution. A probability curve is associated with the most important variables. Some of Elf's experience with tail production and removal policy is described. The tail production from a gas field is a great challenge for the operator of the field, but the other actors should also be concerned with this part of a field's lifetime. So far there is no absolute requirement that large platforms must be removed. The presentations end with some discussion about economy and production policies for the final years of a field. 3 figs

  6. Doses resulting from intrusion into uranium tailings areas

    International Nuclear Information System (INIS)

    Walsh, M.L.

    1986-02-01

    In the future, it is conceivable that institutional controls of uranium tailings areas may cease to exist and individuals may intrude into these areas unaware of the potential radiation hazards. The objective of this study was to estimate the potential doses to the intruders for a comprehensive set of intrusion scenarios. Reference tailings areas in the Elliot Lake region of northern Ontario and in northern Saskatchewan were developed to the extent required to calculate radiation exposures. The intrusion scenarios for which dose calculations were performed, were categorized into the following classes: habitation of the tailings, agricultural activities, construction activities, and recreational activities. Realistic exposure conditions were specified and annual doses were calculated by applying standard dose conversion factors. The exposure estimates demonstrated that the annual doses resulting from recreational activities and from construction activities would be generally small, less than twenty millisieverts, while the habitational and agricultural activities could hypothetically result in doses of several hundred millisieverts. However, the probability of occurrence of these latter classes of scenarios is considered to be much lower than scenarios involving either construction or recreational activities

  7. Understanding the heavy-tailed dynamics in human behavior.

    Science.gov (United States)

    Ross, Gordon J; Jones, Tim

    2015-06-01

    The recent availability of electronic data sets containing large volumes of communication data has made it possible to study human behavior on a larger scale than ever before. From this, it has been discovered that across a diverse range of data sets, the interevent times between consecutive communication events obey heavy-tailed power law dynamics. Explaining this has proved controversial, and two distinct hypotheses have emerged. The first holds that these power laws are fundamental, and arise from the mechanisms such as priority queuing that humans use to schedule tasks. The second holds that they are statistical artifacts which only occur in aggregated data when features such as circadian rhythms and burstiness are ignored. We use a large social media data set to test these hypotheses, and find that although models that incorporate circadian rhythms and burstiness do explain part of the observed heavy tails, there is residual unexplained heavy-tail behavior which suggests a more fundamental cause. Based on this, we develop a quantitative model of human behavior which improves on existing approaches and gives insight into the mechanisms underlying human interactions.

  8. Predicting Tail Buffet Loads of a Fighter Airplane

    Science.gov (United States)

    Moses, Robert W.; Pototzky, Anthony S.

    2006-01-01

    Buffet loads on aft aerodynamic surfaces pose a recurring problem on most twin-tailed fighter airplanes: During maneuvers at high angles of attack, vortices emanating from various surfaces on the forward parts of such an airplane (engine inlets, wings, or other fuselage appendages) often burst, immersing the tails in their wakes. Although these vortices increase lift, the frequency contents of the burst vortices become so low as to cause the aft surfaces to vibrate destructively. Now, there exists a new analysis capability for predicting buffet loads during the earliest design phase of a fighter-aircraft program. In effect, buffet pressures are applied to mathematical models in the framework of a finite-element code, complete with aeroelastic properties and working knowledge of the spatiality of the buffet pressures for all flight conditions. The results of analysis performed by use of this capability illustrate those vibratory modes of a tail fin that are most likely to be affected by buffet loads. Hence, the results help in identifying the flight conditions during which to expect problems. Using this capability, an aircraft designer can make adjustments to the airframe and possibly the aerodynamics, leading to a more robust design.

  9. Optimal heavy tail estimation – Part 1: Order selection

    Directory of Open Access Journals (Sweden)

    M. Mudelsee

    2017-12-01

    Full Text Available The tail probability, P, of the distribution of a variable is important for risk analysis of extremes. Many variables in complex geophysical systems show heavy tails, where P decreases with the value, x, of a variable as a power law with a characteristic exponent, α. Accurate estimation of α on the basis of data is currently hindered by the problem of the selection of the order, that is, the number of largest x values to utilize for the estimation. This paper presents a new, widely applicable, data-adaptive order selector, which is based on computer simulations and brute force search. It is the first in a set of papers on optimal heavy tail estimation. The new selector outperforms competitors in a Monte Carlo experiment, where simulated data are generated from stable distributions and AR(1 serial dependence. We calculate error bars for the estimated α by means of simulations. We illustrate the method on an artificial time series. We apply it to an observed, hydrological time series from the River Elbe and find an estimated characteristic exponent of 1.48 ± 0.13. This result indicates finite mean but infinite variance of the statistical distribution of river runoff.

  10. Long-term protection of uranium mill tailings

    Energy Technology Data Exchange (ETDEWEB)

    Beedlow, P.A.; Hartley, J.N.

    1984-04-01

    US Environmental Protection Agency standards for the cleanup and disposal of inactive tailings sites require that control measures for disposal of tailings be designed to be effective for up to 1000 years if reasonably achievable, and, in any case, for 200 years at least. To control the escape of contaminants over such long periods, containment systems must be capable of adjusting to changing environmental conditions. Elements of a containment system include surface covers, biotic barriers, radon barriers, and, in some cases, liners. Each element of the system affects the others, and the whole system responds to the surrounding environment. Interaction is facilitated primarily by soil moisture. Consequently, the control of soil moisture is critical to the effectiveness of containment systems. Protective covers are necessary to prevent disruption of the containment system by physical or biological factors, to provide for the effective functioning of the radon barrier, and to prevent infiltration of excess water that could cause leaching. In order to design protective covers, a working knowledge of the factors and processes impacting tailings piles is required. This report characterizes the major factors and processes, and presents generic solutions based on current research. 65 references, 9 figures, 6 tables.

  11. Green mines green energy : establishing productive land on mine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Tisch, B.; Zinck, J.; Vigneault, B. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Mining and Mineral Sciences Laboratories

    2008-07-01

    Municipal governments and provincial regulators are under increasing pressure to divert clean organic waste materials from landfill sites and establish productive uses for them. This article described the Natural Resources Canada (NRCan) CANMET Green Mines Green Energy consortium. Composed of mining, forestry, government, and academic representatives, the consortium's aim is to expand the use of organic waste residuals in the rehabilitation of mine sites for use as a feedstock in biofuel production. The program's themes include: (1) determining the conditions required to maximize growth; (2) investigating the interaction of various organic covers on tailings pore water, effluent and mineralogy; (3) investigating the potential economic and environmental impacts on all relevant sectors; and (4) disseminating findings to all relevant stakeholders. Tests are currently being conducted to determine the potential impact of municipal waste materials on tailings oxidation and effluent chemistry. The effect of biosolids and compost-derived dissolved organic carbon on effluent treatability and toxicity is also being investigated. Results from the investigations to date suggest that sulfate reduction at the tailings-biosolids interface is taking place. It was concluded that steady state has not yet been reached after a 1 year period. 10 refs., 1 tab., 7 figs.

  12. Anatomy and evolution of heterocercal tail in lamniform sharks.

    Science.gov (United States)

    Kim, Sun H; Shimada, Kenshu; Rigsby, Cynthia K

    2013-03-01

    Lamniformes is a small shark group consisting of 15 extant species with remarkably diverse lifestyles and a wide range in heterocercal tail morphology. The caudal fin morphology must be related to their lifestyle because the tail is a main locomotive structure in sharks, but such relationships have remained largely uninvestigated. Here, the morphology-lifestyle relationship in lamniforms is examined through phylogenetic mapping. This study suggests that, within Lamniformes, caudal fins with a more horizontally directed curvature of the vertebral column are plesiomorphic, whereas those with a large dorsally directed curvature of the vertebral column are apomorphic. It also shows that caudal fins with posteriorly directed hypochordal rays are plesiomorphic, and that those with ventrally directed hypochordal rays are apomorphic within Lamniformes. Four basic caudal fin types are recognized in lamniforms on the basis of these skeletal variables in which one corollary is that the evolution of external morphology of caudal fin does not necessarily correspond to the evolution of its skeletal anatomy. This study also demonstrates that specific lifestyles seen in different lamniforms are indeed correlative with different caudal fin types in which a less asymmetrical heterocercal tail is a derived feature in lamniforms that evolved for fast swimming to capture fast swimming prey. Copyright © 2013 Wiley Periodicals, Inc.

  13. Disease limits populations: plague and black-tailed prairie dogs.

    Science.gov (United States)

    Cully, Jack F; Johnson, Tammi L; Collinge, Sharon K; Ray, Chris

    2010-01-01

    Plague is an exotic vector-borne disease caused by the bacterium Yersinia pestis that causes mortality rates approaching 100% in black-tailed prairie dogs (Cynomys ludovicianus). We mapped the perimeter of the active portions of black-tailed prairie dog colonies annually between 1999 and 2005 at four prairie dog colony complexes in areas with a history of plague, as well as at two complexes that were located outside the distribution of plague at the time of mapping and had therefore never been affected by the disease. We hypothesized that the presence of plague would significantly reduce overall black-tailed prairie dog colony area, reduce the sizes of colonies on these landscapes, and increase nearest-neighbor distances between colonies. Within the region historically affected by plague, individual colonies were smaller, nearest-neighbor distances were greater, and the proportion of potential habitat occupied by active prairie dog colonies was smaller than at plague-free sites. Populations that endured plague were composed of fewer large colonies (>100 ha) than populations that were historically plague free. We suggest that these differences among sites in colony size and isolation may slow recolonization after extirpation. At the same time, greater intercolony distances may also reduce intercolony transmission of pathogens. Reduced transmission among smaller and more distant colonies may ultimately enhance long-term prairie dog population persistence in areas where plague is present.

  14. Effects of tailing dam profiles on relative wind erosion rates

    Energy Technology Data Exchange (ETDEWEB)

    Coffey, P.S.; Scott, W.D.; Summers, K.J.

    Erosion from mine treatment and associated residue areas can pose a significant environmental problem for surrounding locations from dust and other transported materials. The shape of such residue areas can influence windfield behavior by causing significant wind speed increases. Residue areas are often unprotected so that increasing the speed of wind passing over these areas will cause extra erosion. Values of wind speed-up predicted by an empirical model for wind flow over hills of low slope were compared with measured values over approach slopes to a tailings dam. Hunt's model used in this study relates wind speed from a point on the hill to that observed if there was no hill. Measured values are in agreement with those predicted by the model. Shear stress values calculated from the wind flow model are then used to determine the friction velocity which, in turn, predict the relative rates of erosion. This prediction is based on the cubic relation between the friction velocity and erosion rate observed by Bagnold. These calculations are repeated for the various possible hill shapes allowed by the plant layout and the need to integrate long term spoil heaps with existing topography. A strategy for minimizing erosion of mine tailings through shape selection can then form part of the environmental considerations associated with tailings dams.

  15. Tail docking in dogs: can attitude change be achieved?

    Science.gov (United States)

    Bennett, P; Perini, E

    2003-05-01

    The debate about tail docking in domestic dogs continues to rage in many developed countries and attitudes expressed by different community groups remain diametrically opposed. Veterinary associations and welfare organisations typically want the practice banned, while many breeders and pure-bred dog associations just as vigorously oppose the introduction of anti-docking legislation. In recent years, much data have been accumulated concerning the welfare implications of tail docking. A recent evaluation of this literature suggests that the practice has little to recommend it and that, in the absence of reasonable case-by-case justification, it may constitute an unacceptable abuse of a sentient species. Given this situation, it is difficult to understand why many canine interest groups, presumably representing those people who care most about the welfare of companion dogs, should continue to hold such strong attitudes in favour of tail docking. In this review we attempt to explain why different community groups might espouse strong but opposing attitudes, despite having access to the same information. We argue that the theory of cognitive dissonance, popular among social psychologists, may provide a useful framework within which to understand, and attempt to alter, attitudes that persist even though they appear contrary to available empirical evidence.

  16. Long-term protection of uranium mill tailings

    International Nuclear Information System (INIS)

    Beedlow, P.A.; Hartley, J.N.

    1984-04-01

    US Environmental Protection Agency standards for the cleanup and disposal of inactive tailings sites require that control measures for disposal of tailings be designed to be effective for up to 1000 years if reasonably achievable, and, in any case, for 200 years at least. To control the escape of contaminants over such long periods, containment systems must be capable of adjusting to changing environmental conditions. Elements of a containment system include surface covers, biotic barriers, radon barriers, and, in some cases, liners. Each element of the system affects the others, and the whole system responds to the surrounding environment. Interaction is facilitated primarily by soil moisture. Consequently, the control of soil moisture is critical to the effectiveness of containment systems. Protective covers are necessary to prevent disruption of the containment system by physical or biological factors, to provide for the effective functioning of the radon barrier, and to prevent infiltration of excess water that could cause leaching. In order to design protective covers, a working knowledge of the factors and processes impacting tailings piles is required. This report characterizes the major factors and processes, and presents generic solutions based on current research. 65 references, 9 figures, 6 tables

  17. The avian tail reduces body parasite drag by controlling flow separation and vortex shedding.

    OpenAIRE

    Maybury, W. J.; Rayner, J. M.

    2001-01-01

    The aerodynamic effect of the furled avian tail on the parasite drag of a bird's body was investigated on mounted, frozen European starling Sturnus vulgaris in a wind tunnel at flight speeds between 6 and 14 m s(-1). Removal of tail rectrices and dorsal and ventral covert feathers at the base of the tail increased the total parasite drag of the body and tail by between 25 and 55%. Flow visualization and measurements of dynamic pressure in the tail boundary layer showed that in the intact bird...

  18. Summary of the engineering assessment of inactive uranium mill tailings: Lakeview Site, Lakeview, Oregon

    International Nuclear Information System (INIS)

    1981-10-01

    Radon gas released from the 130,000 tons of tailings at the Lakeview site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The three alternative actions include millsite decontamination with the addition of 3 m of stabilization cover material (Option I) and removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II and III). Cost estimates range from $6,000,000 for stabilization in-place, to $7,500,000 for disposal at a distance of about 10 miles. Three alternatives for reprocessing the Lakeview tailings were examined. Results show that uranium recovery is not economical

  19. Social networks in the lek-mating wire-tailed manakin (Pipra filicauda)

    Science.gov (United States)

    Ryder, Thomas B; McDonald, David B; Blake, John G; Parker, Patricia G; Loiselle, Bette A

    2008-01-01

    How social structure interacts with individual behaviour and fitness remains understudied despite its potential importance to the evolution of cooperation. Recent applications of network theory to social behaviour advance our understanding of the role of social interactions in various contexts. Here we applied network theory to the social system of lek-mating wire-tailed manakins (Pipra filicauda, Pipridae, Aves). We analysed the network of interactions among males in order to begin building a comparative framework to understand where coordinated display behaviour lies along the continuum from solitary to obligately cooperative dual-male displays in the family Pipridae. Network degree (the number of links from a male to others) ranged from 1 to 10, with low mean and high variance, consistent with the theory for the evolution of cooperation within social networks. We also assessed factors that could predict social and reproductive success of males. Four network metrics, degree, eigenvector centrality, information centrality and reach, some of which assess circuitous as well as the shortest (geodesic) paths of male connectivity, predicted male social rise. The duration of a male's territorial tenure during the 4 years of the study predicted his probability of siring offspring. PMID:18381257

  20. CT findings of normal pancreatic tail: variety of morphology and location

    International Nuclear Information System (INIS)

    Han, Hye Seung; Son, San Hoo; Moon, Gae Hyuk; Kim, Hu Ho; Gong Jae Chul; Yang Jae Boum; Park, Mee Sook

    1998-01-01

    To determine the morphology and location of normal pancreatic tail, as seen on abdominal CT. A hundred and one patients without pancreatic disease underwent CT scanning. We then determined how to relate the location of the pancreatic tail with the splenic hilum, left kidney, and pancreatic body. We compared the thickness of the tail with that of the body and analysed of the morphology of the tail. Seventy-seven percent of all pancreatic tails were located below the splenic hilum, with 59% of this proportion located 1 to 2 cm below. Fifty percent of tails were located at the level of the uppermost quarter of the left kidney, and a further 27% at the level of the second quarter; 75 % were located in the ventrolateral portion of this kidney and 23% in the ventral portion. In 48% of patients, the pancreatic tail and body were the same thickness, and in a further 48 %, the tail was thicker than the body. In 34% of patients, the tail showed focal bulging, and in another 32%, it tapered smoothly. Forty seven percent of tails were located below the pancreatic body and a further 37% were found at the same level as the body. Abdominal CT scans showed differing morphology and location of the pancreatic tail. The recognition of these variations will diminish speculation as to their true nature. (author). 12 refs., 4 figs

  1. Direct Observation of Heavy-Tailed Storage Times of Bed Load Tracer Particles Causing Anomalous Superdiffusion

    Science.gov (United States)

    Bradley, D. Nathan

    2017-12-01

    A consensus has formed that the step length distribution of fluvial bed load is thin tailed and that the observed anomalous superdiffusion of bed load tracer particles must arise from heavy-tailed resting times. However, heavy-tailed resting times have never been directly observed in the field over multiple floods. Using 9 years of data from a large bed load tracer experiment, I show that the spatial variance of the tracer plume scales faster than linearly with integrated excess stream power, indicating anomalous superdiffusion. The superdiffusion is caused by a heavy-tailed distribution of observed storage times that is fit with a truncated Pareto distribution with a tail parameter that is predicted by anomalous diffusion theory. The heavy-tailed distribution of storage times causes the tracer virtual velocity to slow over time, indicated by a sublinear increase in the mean displacement that is predicted by the storage time distribution tail parameter.

  2. Potential Risk Analysis of Tailings Dam under Preloading Condition and Its Countermeasures

    Directory of Open Access Journals (Sweden)

    Shuren Wang

    2015-01-01

    Full Text Available It is very important for mine production safety to ensure the stability of the tailings dam. Taking a flatland tailings pond as the background, a threedimensional computational model was built based on a tailings dam under mullock heap preloading condition. Considering the current operating water level conditions, a liquid-solid coupling analysis of the model was conducted.The deformation characteristics of the tailings dam were revealed during successive preloading at the front of the dam. The safety factor and the potential slide face of the tailings dam were calculated under different conditions using the strength reduction method. The results show that the tailings dam in its current condition is basically stable, but if the mullock heap continues to be heightened, the tailings dam will become unstable. Therefore, in order to limit the height of the mullock heap, establishing a monitor and early warning mechanism are put forward to ensure mine production safety.

  3. Aerodynamic study on wing and tail small UAV without runways

    Science.gov (United States)

    Soetanto, Maria F.; R., Randy; Alfan M., R.; Dzaldi

    2016-06-01

    This paper consists of the design and analysis of the aerodynamics of the profiles of wing and tail of a Small Unmanned Aerial Vehicle (UAV). UAV is a remote-controlled aircraft that can carry cameras, sensors and even weapons on an area that needed aerial photography or aerial video [1]. The aim of this small UAV is for used in situations where manned flight is considered too risky or difficult, such as fire fighting or surveillance, while the term 'small means the design of this UAV has to be relatively small and portable so that peoples are able to carry it during their operations [CASR Part 101.240: it is a UAV which is has a launch mass greater than 100 grams but less than 100 kilograms] [2]. Computational Fluid Dynamic (CFD) method was used to analyze the fluid flow characteristics around the aerofoil's profiles, such as the lift generation for each angle of attack and longitudinal stability caused by vortex generation on trailing edge. Based on the analysis and calculation process, Clark-Y MOD with aspect ratio, AR = 4.28 and taper ratio, λ = 0.65 was chosen as the wing aerofoil and SD 8020 with AR = 4.8 and λ = 0.5 was chosen as the horizontal tail, while SD 8020 with AR = 1.58 and λ = 0.5 was chosen as the vertical tail. The lift and drag forces generated for wing and tail surfaces can be determined from the Fluent 6.3 simulation. Results showed that until angle of attack of 6 degrees, the formation of flow separation is still going on behind the trailing edge, and the stall condition occurs at 14 degrees angle of attack which is characterized by the occurrence of flow separation at leading edge, with a maximum lift coefficient (Cl) obtained = 1.56. The results of flight tests show that this small UAV has successfully maneuvered to fly, such as take off, some acrobatics when cruising and landing smoothly, which means that the calculation and analysis of aerodynamic aerofoil's profile used on the wing and tail of the Small UAV were able to be validated.

  4. Device for Writing the Time Tail from Spallation Neutron Pulses

    International Nuclear Information System (INIS)

    Langan, P.; Schoenborn, Benno P.; Daemen, L.L.

    2001-01-01

    Recent work at Los Alamos Neutron Science Center (LANSCE), has shown that there are large gains in neutron beam intensity to be made by using coupled moderators at spallation neutron sources. Most of these gains result from broadening the pulse-width in time. However the accompanying longer exponential tail at large emission times can be a problem in that it introduces relatively large beam-related backgrounds at high resolutions. We have designed a device that can reshape the moderated neutron beam by cutting the time-tail so that a sharp time resolution can be re-established without a significant loss in intensity. In this work the basic principles behind the tail-cutter and some initial results of Monte Carlo simulations are described. Unwanted neutrons in the long time-tail are diffracted out of the transmitted neutron beam by a nested stack of aperiodic multi-layers, rocking at the same frequency as the source. Nested aperiodic multi-layers have recently been used at X-ray sources and as band-pass filters in quasi-Laue neutron experiments at reactor neutron sources. Optical devices that rock in synchronization with a pulsed neutron beam are relatively new but are already under construction at LANSCE. The tail-cutter described here is a novel concept that uses existing multi-layer technology in a new way for spallation neutrons. Coupled moderators in combination with beam shaping devices offer the means of increasing flux whilst maintaining a sharp time distribution. A prototype device is being constructed for the protein crystallography station at LANSCE. The protein crystallography station incorporates a water moderator that has been judiciously coupled in order to increase the flux over neutron energies that are important to structural biology (3-80meV). This development in moderator design is particularly important because protein crystallography is flux limited and because conventional ambient water and cold hydrogen moderators do not provide relatively

  5. Community-Supported Data Repositories in Paleobiology: A 'Middle Tail' Between the Geoscientific and Informatics Communities

    Science.gov (United States)

    Williams, J. W.; Ashworth, A. C.; Betancourt, J. L.; Bills, B.; Blois, J.; Booth, R.; Buckland, P.; Charles, D.; Curry, B. B.; Goring, S. J.; Davis, E.; Grimm, E. C.; Graham, R. W.; Smith, A. J.

    2015-12-01

    Community-supported data repositories (CSDRs) in paleoecology and paleoclimatology have a decades-long tradition and serve multiple critical scientific needs. CSDRs facilitate synthetic large-scale scientific research by providing open-access and curated data that employ community-supported metadata and data standards. CSDRs serve as a 'middle tail' or boundary organization between information scientists and the long-tail community of individual geoscientists collecting and analyzing paleoecological data. Over the past decades, a distributed network of CSDRs has emerged, each serving a particular suite of data and research communities, e.g. Neotoma Paleoecology Database, Paleobiology Database, International Tree Ring Database, NOAA NCEI for Paleoclimatology, Morphobank, iDigPaleo, and Integrated Earth Data Alliance. Recently, these groups have organized into a common Paleobiology Data Consortium dedicated to improving interoperability and sharing best practices and protocols. The Neotoma Paleoecology Database offers one example of an active and growing CSDR, designed to facilitate research into ecological and evolutionary dynamics during recent past global change. Neotoma combines a centralized database structure with distributed scientific governance via multiple virtual constituent data working groups. The Neotoma data model is flexible and can accommodate a variety of paleoecological proxies from many depositional contests. Data input into Neotoma is done by trained Data Stewards, drawn from their communities. Neotoma data can be searched, viewed, and returned to users through multiple interfaces, including the interactive Neotoma Explorer map interface, REST-ful Application Programming Interfaces (APIs), the neotoma R package, and the Tilia stratigraphic software. Neotoma is governed by geoscientists and provides community engagement through training workshops for data contributors, stewards, and users. Neotoma is engaged in the Paleobiological Data Consortium

  6. A regional assessment of white-tailed deer effects on plant invasion

    Energy Technology Data Exchange (ETDEWEB)

    Averill, Kristine M. [Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA; Department of Plant Sciences, The Pennsylvania State University, University Park, PA, USA; Mortensen, David A. [Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA; Department of Plant Sciences, The Pennsylvania State University, University Park, PA, USA; Smithwick, Erica A. H. [Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA; Department of Geography, The Pennsylvania State University, University Park, PA, USA; Kalisz, Susan [Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA; McShea, William J. [Smithsonian Conservation Biology Institute, Front Royal, VA, USA; Bourg, Norman A. [Smithsonian Conservation Biology Institute, Front Royal, VA, USA; Parker, John D. [Smithsonian Environmental Research Center, Edgewater, MD, USA; Royo, Alejandro A. [United States Department of Agriculture Forest Service, Northern Research Station, Irvine, PA, USA; Abrams, Marc D. [Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA; Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, USA; Apsley, David K. [Department of Extension, The Ohio State University, Jackson, OH, USA; Blossey, Bernd [Department of Natural Resources, Cornell University, Ithaca, NY, USA; Boucher, Douglas H. [Department of Biology, Hood College, Frederick, MD, USA; Caraher, Kai L. [Department of Biology, Hood College, Frederick, MD, USA; DiTommaso, Antonio [Soil and Crop Sciences Section, Cornell University, Ithaca, NY, USA; Johnson, Sarah E. [Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA; Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, USA; Masson, Robert [National Park Service, Morristown National Historical Park, Morristown, NJ, USA; Nuzzo, Victoria A. [Natural Area Consultants, Richford, NY, USA

    2017-12-07

    Herbivores can profoundly influence plant species assembly, including plant invasion, and resulting community composition. Population increases of native herbivores, e.g., white-tailed deer (Odocoileus virginianus), combined with burgeoning plant invasions raise concerns for native plant diversity and forest regeneration. While individual researchers typically test for the impact of deer on plant invasion at a few sites, the overarching influence of deer on plant invasion across regional scales is unclear. We tested the effects of deer on the abundance and diversity of introduced and native herbaceous and woody plants across 23 white-tailed deer research sites distributed across the east central and northeastern United States and representing a wide range of deer densities and invasive plant abundance and identity. Deer access/exclusion or deer population density did not affect introduced plant richness or community-level abundance. Native and total plant species richness, abundance (cover and stem density), and Shannon diversity were lower in deer-access vs. deer-exclusion plots. Among deer access plots, native species richness, native and total cover, and Shannon diversity (cover) declined as deer density increased. Deer access increased the proportion of introduced species cover (but not of species richness or stem density). As deer density increased, the proportion of introduced species richness, cover, and stem density all increased. Because absolute abundance of introduced plants was unaffected by deer, the increase in proportion of introduced plant abundance is likely an indirect effect of deer reducing native cover. Indicator species analysis revealed that deer access favored three introduced plant species, including Alliaria petiolata and Microstegium vimineum, as well as four native plant species. In contrast, deer exclusion favored three introduced plant species, including Lonicera japonica and Rosa multiflora, and fifteen native plant species. Overall

  7. Postsacral vertebral morphology in relation to tail length among primates and other mammals.

    Science.gov (United States)

    Russo, Gabrielle A

    2015-02-01

    Tail reduction/loss independently evolved in a number of mammalian lineages, including hominoid primates. One prerequisite to appropriately contextualizing its occurrence and understanding its significance is the ability to track evolutionary changes in tail length throughout the fossil record. However, to date, the bony correlates of tail length variation among living taxa have not been comprehensively examined. This study quantifies postsacral vertebral morphology among living primates and other mammals known to differ in relative tail length (RTL). Linear and angular measurements with known biomechanical significance were collected on the first, mid-, and transition proximal postsacral vertebrae, and their relationship with RTL was assessed using phylogenetic generalized least-squares regression methods. Compared to shorter-tailed primates, longer-tailed primates possess a greater number of postsacral vertebral features associated with increased proximal tail flexibility (e.g., craniocaudally longer vertebral bodies), increased intervertebral body joint range of motion (e.g., more circularly shaped cranial articular surfaces), and increased leverage of tail musculature (e.g., longer spinous processes). These observations are corroborated by the comparative mammalian sample, which shows that distantly related short-tailed (e.g., Phascolarctos, Lynx) and long-tailed (e.g., Dendrolagus, Acinonyx) nonprimate mammals morphologically converge with short-tailed (e.g., Macaca tonkeana) and long-tailed (e.g., Macaca fascicularis) primates, respectively. Multivariate models demonstrate that the variables examined account for 70% (all mammals) to 94% (only primates) of the variance in RTL. Results of this study may be used to infer the tail lengths of extinct primates and other mammals, thereby improving our understanding about the evolution of tail reduction/loss. © 2014 Wiley Periodicals, Inc.

  8. Tail loss affects fecundity but not offspring traits in the Chinese skink Eumeces chinensis

    Directory of Open Access Journals (Sweden)

    Hongliang LU, Jianfang GAO, Xiaohao MA, Zhihua LIN, Xiang JI

    2012-04-01

    Full Text Available We used the Chinese skink Eumeces chinensis as a model animal to study the effects of tail loss on reproductive investment and offspring traits. A total of 147 wild-captured adult females were divided into four groups according to their tail conditions. Tail breaks occurred most frequently in the proximal portion of the tail and least frequently in the distal portion, with the middle portion in between. This finding suggests that tail breaks occurring in nature often entails substantial energetic costs in E. chinensis where the tail is a major site of energy storage. The proportion of females that laid eggs was higher in females with intact or completely regenerated tails than in those with broken tails. Following whole-tail autotomy, the clutch size was reduced by 17%, and the clutch mass was reduced by 14%. Females undergoing substantial tail autotomy reduced reproductive investment, and they did so by reducing the number but not the size of eggs produced. None of the egg and hatchling traits was affected by tail loss. Comparing our data with those reported for other oviparous and viviparous skinks allows us to draw two general conclusions: one is that fecundity (clutch or litter size is affected by tail loss in all species so far studied, whereas offspring size is affected by tail loss in some species, but not in others; the other is that the reduction in fecundity following tail loss is more evident in species lacking abdominal fat bodies [Current Zoology 58 (2: 228-235, 2012].

  9. Near-threshold quantization and scattering for deep potentials with attractive tails

    International Nuclear Information System (INIS)

    Eltschka, Christopher; Moritz, Michael J.; Friedrich, Harald

    2000-01-01

    Near-threshold properties of bound and continuum states in a deep potential with an attractive tail depend essentially on a few 'tail parameters', which are determined by the properties of the potential tail beyond the region of r-values where WKB wavefunctions are accurate solutions of the Schroedinger equation. One of these tail parameters is a length parameter which defines the singular contribution to the level density just below threshold and the reflectivity of the tail of the potential just above threshold; another is a phase difference which, together with the length parameter, determines the mean scattering length. The near-threshold quantization rule and the actual scattering length are determined by the tail parameters together with a dimensionless constant depending on the zero-energy value of the WKB action integral. We study potentials with tails consisting of two inverse-power terms, V(r)∼-C α /r α -C α 1 /r α 1 ,α 1 >α>2and we derive exact analytical expressions for the tail parameters in the special case α 1 =2(α-1). This enables us to demonstrate the effect of a significant non-homogeneity of the potential tail on the results derived previously for homogeneous tails. (author)

  10. Application of a life cycle assessment to compare environmental performance in coal mine tailings management.

    Science.gov (United States)

    Adiansyah, Joni Safaat; Haque, Nawshad; Rosano, Michele; Biswas, Wahidul

    2017-09-01

    This study compares coal mine tailings management strategies using life cycle assessment (LCA) and land-use area metrics methods. Hybrid methods (the Australian indicator set and the ReCiPe method) were used to assess the environmental impacts of tailings management strategies. Several strategies were considered: belt filter press (OPT 1), tailings paste (OPT 2), thickened tailings (OPT 3), and variations of OPT 1 using combinations of technology improvement and renewable energy sources (OPT 1A-D). Electrical energy was found to contribute more than 90% of the environmental impacts. The magnitude of land-use impacts associated with OPT 3 (thickened tailings) were 2.3 and 1.55 times higher than OPT 1 (tailings cake) and OPT 2 (tailings paste) respectively, while OPT 1B (tailings belt filter press with technology improvement and solar energy) and 1D (tailings belt press filter with technology improvement and wind energy) had the lowest ratio of environmental impact to land-use. Further analysis of an economic cost model and reuse opportunities is required to aid decision making on sustainable tailings management and industrial symbiosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Radon flux from rehabilitated and unrehabilitated uranium mill tailings deposits

    International Nuclear Information System (INIS)

    Sonter, M.; Akber, R.; Holdsworth, S.

    2002-01-01

    Radon release from uranium tailings deposits was identified in UNSCEAR 1993 as the main potential source of collective dose to the world population from the use of nuclear power (rather than, say, gamma doses to power plant workers, or doses to reprocessing plant workers or to waste-handling workers, or residents living adjacent to these facilities). This is due primarily to the ongoing nature of the radon releases over geological time and to the assumption of a 10,000 year integration time. UNSCEAR 1993 estimated 150 person-sieverts per GWe-yr of produced power, based on some very general assumptions about area of tailings per unit of uranium produced, uranium usage per unit of power produced, radon emanation per unit surface area of tails, population density within 100 km of the site, and from 100 km out to 2000 km from the site, and atmospheric dispersion. It should be noted at the outset that the idea of adding vanishingly small doses across the entire world population and integrating for 10,000 years into the future, to obtain a collective dose which is then used to infer induced cancer deaths, is warned against by ICRP, and more strongly disavowed in recent papers by Roger Clarke, as being unrepresentative of any real risk and a recipe for misallocation of resources. These UNSCEAR assumptions and the resulting estimations of collective dose were reviewed by SENES Consultants Ltd of Canada, in a report commissioned by the Uranium Institute, both in terms of the methodology and in terms of the factors used. In this report SENES substituted its best estimate assumptions, based on responses received from major commercial uranium mining operations for UNSCEAR's assumptions, which it identified as highly pessimistic, and arrived at a putative collective dose of about 1 person-sievert/ GWe-yr. The most recent UNSCEAR 2000 report acknowledges the uncertainty in the figures, and references the SENES report as providing more specific (but still limited) data. Taking on

  12. Central Diabetes Insipidus, Central Hypothyroidism, Renal Tubular ...

    African Journals Online (AJOL)

    diseases, primary hypothyroidism, and other disorders of the central nervous, gastrointestinal, genitourinary, and orthopedic systems. In this report, we describe a 3‑month‑old Saudi boy with the rare association of DWS with central diabetes insipidus, congenital central hypothyroidism, and type‑2 renal tubular acidosis.

  13. Dynamic and photometric evolutionary models of tidal tails and ripples

    International Nuclear Information System (INIS)

    Wallin, J.F.

    1989-01-01

    An investigation into the causes of star formation in tidal tails has been conducted using a restricted three-body dynamical model in conjunction with a broad-band photometric evolutionary code. In these models, regions of compression form inside the disk and along the tidal tail and tidal bridge. The effects these density changes have on the colors of the tidal features are examined with a broad-band photometric evolutionary code. A spiral galaxy population is synthesized and the effects of modest changes in the star formation rate are explored. Limits on the density changes needed to make detectable changes in the colors are calculated using a Schmidt (1959) law. These models suggest that the blue colors and knotty features observed in the tidal features of some galaxies result from increased rates of star formation induced by tidally produced density increases. Limitations of this model are discussed along with photometric evolutionary models based on the density evolution in the tails. The Lynds and Toomre (1976) interpretation of ring galaxies as the natural result of a nearly head-on collision between a disk galaxy and a companion galaxy has become widely accepted. Similarly, Quinn's (1984) interpretation of the shells in elliptical galaxies as the aftermath of the cannibalization of a low-mass companion has been quite successful in accounting for the observations. Restricted three-body calculations of high inclination, low impact parameter encounters demonstrate that the shell-like ripples observed in a number of disk galaxies can also be produced as collisional artifacts from internal oscillations much as in ring galaxies

  14. Tamarind tree seed dispersal by ring-tailed lemurs.

    Science.gov (United States)

    Mertl-Millhollen, Anne S; Blumenfeld-Jones, Kathryn; Raharison, Sahoby Marin; Tsaramanana, Donald Raymond; Rasamimanana, Hantanirina

    2011-10-01

    In Madagascar, the gallery forests of the south are among the most endangered. Tamarind trees (Tamarindus indica) dominate these riverine forests and are a keystone food resource for ring-tailed lemurs (Lemur catta). At Berenty Reserve, the presence of tamarind trees is declining, and there is little recruitment of young trees. Because mature tamarinds inhibit growth under their crowns, seeds must be dispersed away from adult trees if tree recruitment is to occur. Ring-tailed lemurs are likely seed dispersers; however, because they spend much of their feeding, siesta, and sleeping time in tamarinds, they may defecate a majority of the tamarind seeds under tamarind trees. To determine whether they disperse tamarind seeds away from overhanging tamarind tree crowns, we observed two troops for 10 days each, noted the locations of feeding and defecation, and collected seeds from feces and fruit for germination. We also collected additional data on tamarind seedling recruitment under natural conditions, in which seedling germination was abundant after extensive rain, including under the canopy. However, seedling survival to 1 year was lower when growing under mature tamarind tree crowns than when growing away from an overhanging crown. Despite low fruit abundance averaging two fruits/m(3) in tamarind crowns, lemurs fed on tamarind fruit for 32% of their feeding samples. Daily path lengths averaged 1,266 m, and lemurs deposited seeds throughout their ranges. Fifty-eight percent of the 417 recorded lemur defecations were on the ground away from overhanging tamarind tree crowns. Tamarind seeds collected from both fruit and feces germinated. Because lemurs deposited viable seeds on the ground away from overhanging mature tamarind tree crowns, we conclude that ring-tailed lemurs provide tamarind tree seed dispersal services.

  15. Novel rat tail discitis model using bioluminescent Staphylococcus aureus.

    Science.gov (United States)

    Bostian, Phillip A; Karnes, Jonathan M; Cui, Shari; Robinson, Lisa J; Daffner, Scott D; Witt, Michelle R; Emery, Sanford E

    2017-09-01

    Management of spondylodiscitis is a challenging clinical problem requiring medical and surgical treatment strategies. The purpose of this study was to establish a rat model of spondylodiscitis that utilizes bioluminescent Staphylococcus aureus (S. aureus), thus permitting in vivo surveillance of infection intensity. Inocula of the bioluminescent S. aureus strain XEN36 were created in concentrations of 10 2 CFU/0.1 ml, 10 4  CFU/0.1 ml, and 10 6  CFU/0.1 ml. Three groups of rats were injected with the bacteria in the most proximal intervertebral tail segment. The third most proximal tail segment was injected with saline as a control. Bioluminescence was measured at baseline, 3 days, and weekly for a total of 6 weeks. Detected bioluminescence for each group peaked at day 3 and returned to baseline in 21 days. The average intensity was highest for the experimental group injected with the most concentrated bacterial solution (10 6  CFU/0.1 ml). Radiographic analysis revealed loss of intervertebral disc space and evidence of osseous bridging. Saline-injected spaces exhibited no decrease in intervertebral spacing as compared to distal sites. Histologic analysis revealed neutrophilic infiltrates, destruction of the annulus fibrosus and nucleus pulposus, destruction of vertebral endplates, and osseous bridging. Saline-injected discs exhibited preserved annulus fibrosus and nucleus pulposus on histology. This study demonstrates that injection of bioluminescent S. aureus into the intervertebral disc of a rat tail is a viable animal model for spondylodiscitis research. This model allows for real-time, in vivo quantification of infection intensity, which may decrease the number of animals required for infection studies of the intervertebral disc. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2075-2081, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  16. Random matrix theory for heavy-tailed time series

    DEFF Research Database (Denmark)

    Heiny, Johannes

    2017-01-01

    This paper is a review of recent results for large random matrices with heavy-tailed entries. First, we outline the development of and some classical results in random matrix theory. We focus on large sample covariance matrices, their limiting spectral distributions, the asymptotic behavior...... of their largest and smallest eigenvalues and their eigenvectors. The limits significantly depend on the finite or infiniteness of the fourth moment of the entries of the random matrix. We compare the results for these two regimes which give rise to completely different asymptotic theories. Finally, the limits...

  17. White Tail Disease of Freshwater Prawn, Macrobrachium rosenbergii

    OpenAIRE

    Sahul Hameed, A. S.; Bonami, Jean-Robert

    2012-01-01

    Macrobrachium rosenbergii is the most important cultured freshwater prawn in the world and it is now farmed on a large scale in many countries. Generally, freshwater prawn is considered to be tolerant to diseases but a disease of viral origin is responsible for severe mortalities in larval, post-larval and juvenile stages of prawn. This viral infection namely white tail disease (WTD) was reported in the island of Guadeloupe in 1995 and later in Martinique (FrenchWest Indies) in Taiwan, the Pe...

  18. A Pareto upper tail for capital income distribution

    Science.gov (United States)

    Oancea, Bogdan; Pirjol, Dan; Andrei, Tudorel

    2018-02-01

    We present a study of the capital income distribution and of its contribution to the total income (capital income share) using individual tax income data in Romania, for 2013 and 2014. Using a parametric representation we show that the capital income is Pareto distributed in the upper tail, with a Pareto coefficient α ∼ 1 . 44 which is much smaller than the corresponding coefficient for wage- and non-wage-income (excluding capital income), of α ∼ 2 . 53. Including the capital income contribution has the effect of increasing the overall inequality measures.

  19. Uranium Mill Tailings Remedial Action Project. 1995 Environmental Report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-01

    In accordance with U.S. Department of Energy (DOE) Order 23 1. 1, Environment, Safety and Health Reporting, the DOE prepares an annual report to document the activities of the Uranium Mill Tailings Remedial Action (UMTRA) Project environmental monitoring program. This monitoring must comply with appropriate laws, regulations, and standards, and it must identify apparent and meaningful trends in monitoring results. The results of all monitoring activities must be communicated to the public. The UMTRA Project has prepared annual environmental reports to the public since 1989.

  20. Uranium Mill Tailings Remedial Action Project environmental protection implementation plan

    International Nuclear Information System (INIS)

    1994-10-01

    The Uranium Mill Tailings Remedial Action (UMTRA) Project Environmental Protection Implementation Plan (EPIP) has been prepared in accordance with the requirements of the U.S. Department of Energy (DOE) Order 5400.1. The UMTRA EPIP is updated annually. This version covers the time period of 9 November 1994, through 8 November 1995. Its purpose is to provide management direction to ensure that the UMTRA Project is operated and managed in a manner that will protect, maintain, and where necessary, restore environmental quality, minimize potential threats to public health and the environment, and comply with environmental regulations and DOE policies

  1. Uranium Mill Tailings Remedial Action Project environmental protection implementation plan

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    The Uranium Mill Tailings Remedial Action (UMTRA) Project Environmental Protection Implementation Plan (EPIP) has been prepared in accordance with the requirements of the U.S. Department of Energy (DOE) Order 5400.1. The UMTRA EPIP is updated annually. This version covers the time period of 9 November 1994, through 8 November 1995. Its purpose is to provide management direction to ensure that the UMTRA Project is operated and managed in a manner that will protect, maintain, and where necessary, restore environmental quality, minimize potential threats to public health and the environment, and comply with environmental regulations and DOE policies.

  2. [Synthesis and spectral properties of tailed sercine tetraphenylporphyrin cobalt complex].

    Science.gov (United States)

    Ni, Chun-lin; Zhou, Chun-qiong; Zhou, Yu; He, Zhi-ke; Yuan, Liang-jie

    2004-04-01

    A new tailed sercine tetraphenylporphinatozinc, 5-(p-butoxyphenyl-10,15,20-trichlorophenyl)porphine and cobalt complex (Co[Ser-TPP]) was synthesized and characterized by elementary analysis, UV, IR, 1HNMR and Raman spectra. The electronic absorption spectra of axial coordination reactions of Co[Ser-TPP] with pyridine, 4-methylpyridine, 4-aminopyridine, 4,4-bipyridine, imidazole, 1-methylimidazole and 2-methylimidazole were inverstigated. The results showed that the changes of electronic absorption spectra of Co[Ser-TPP] could be attributed to the axial coordination reactions of Co[Ser-TPP] with pyridine and imidazole series.

  3. On the Favorable Estimation for Fitting Heavy Tailed Data

    Czech Academy of Sciences Publication Activity Database

    Stehlík, M.; Potocký, R.; Waldl, H.; Fabián, Zdeněk

    2010-01-01

    Roč. 25, č. 3 (2010), s. 485-503 ISSN 0943-4062 Grant - others:ASO(SK) SK-0607-BA-018; VEGA(SK) 1/0077/09; 50p14(CZ-AT) AKTION; AKTION(CZ-AT) 54p13 Institutional research plan: CEZ:AV0Z10300504 Keywords : heavy-tailed distribution * exact likelihood ratio test * T-score moment estimator * insurance * Basel II Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.500, year: 2010

  4. Mechanochromic response of the barbules in peacock tail feather

    Science.gov (United States)

    Jiang, Yonggang; Wang, Rui; Feng, Lin; Zhang, Deyuan

    2018-01-01

    Peacock tail feathers exhibit diverse striking brilliancy, as the cortex in different colored barbules of the feathers contains a 2-D photonic-crystal structure. The mechanochromic response of the 2-D photonic structure in peacock feather barbules is measured for the first time, by combining an in-situ stretching device and a reflectivity measurement system. The reflectance spectra of the barbule specimen blueshifts own to stretching along its longitudinal direction. A high strain sensitivity of 5.3 nm/% is obtained for green barbules. It could be of great help in bionic design of strain sensors using 2D photonic crystal structures.

  5. Random matrix theory for heavy-tailed time series

    DEFF Research Database (Denmark)

    Heiny, Johannes

    2017-01-01

    This paper is a review of recent results for large random matrices with heavy-tailed entries. First, we outline the development of and some classical results in random matrix theory. We focus on large sample covariance matrices, their limiting spectral distributions, the asymptotic behavior...... of their largest and smallest eigenvalues and their eigenvectors. The limits significantly depend on the finite or infiniteness of the fourth moment of the entries of the random matrix. We compare the results for these two regimes which give rise to completely different asymptotic theories. Finally, the limits...... of the extreme eigenvalues of sample correlation matrices are examined....

  6. Resistance to plague among black-tailed prairie dog populations.

    Science.gov (United States)

    Rocke, Tonie E; Williamson, Judy; Cobble, Kacy R; Busch, Joseph D; Antolin, Michael F; Wagner, David M

    2012-02-01

    In some rodent species frequently exposed to plague outbreaks caused by Yersinia pestis, resistance to the disease has evolved as a population trait. As a first step in determining if plague resistance has developed in black-tailed prairie dogs (Cynomys ludovicianus), animals captured from colonies in a plague-free region (South Dakota) and two plague-endemic regions (Colorado and Texas) were challenged with Y. pestis at one of three doses (2.5, 250, or 2500 mouse LD50s). South Dakota prairie dogs were far more susceptible to plague than Colorado and Texas prairie dogs (pplague resistance.

  7. Pseudo Random Coins Show More Heads Than Tails

    OpenAIRE

    Bauke, Heiko; Mertens, Stephan

    2003-01-01

    Tossing a coin is the most elementary Monte Carlo experiment. In a computer the coin is replaced by a pseudo random number generator. It can be shown analytically and by exact enumerations that popular random number generators are not capable of imitating a fair coin: pseudo random coins show more heads than tails. This bias explains the empirically observed failure of some random number generators in random walk experiments. It can be traced down to the special role of the value zero in the ...

  8. Beam-beam tails simulation for KEK B-factory

    International Nuclear Information System (INIS)

    Shatilov, D.

    1996-12-01

    The special tracking technique is applied for investigation of the beam-beam interaction for KEK B-factory with a crossing angle at the IP. This technique allows us to save a lot of CPU time while simulating the beam tails. The detailed comparison with the brute force tracking code has been performed in order to confirm the validity of the technique. After that, some simulation results for KEKB are presented, which have shown that, in spite of synchro-betatron resonances induced by a crossing angle at the IP, the beam halo growing is quite acceptable. (author)

  9. Uranium Mill Tailings Remedial Action Project. 1995 Environmental Report

    International Nuclear Information System (INIS)

    1996-06-01

    In accordance with U.S. Department of Energy (DOE) Order 23 1. 1, Environment, Safety and Health Reporting, the DOE prepares an annual report to document the activities of the Uranium Mill Tailings Remedial Action (UMTRA) Project environmental monitoring program. This monitoring must comply with appropriate laws, regulations, and standards, and it must identify apparent and meaningful trends in monitoring results. The results of all monitoring activities must be communicated to the public. The UMTRA Project has prepared annual environmental reports to the public since 1989

  10. Central Nervous System Vasculitis

    Science.gov (United States)

    ... Forms of Vasculitis / Central Nervous System (CNS) Vasculitis Central Nervous System (CNS) Vasculitis Swap out your current Facebook Profile ... your Facebook personal page. Replace with this image. Central nervous system (CNS) vasculitis is inflammation of blood vessel walls ...

  11. Mucinous cystic neoplasms and serous cystadenomas arising in the body-tail of the pancreas: MR imaging characterization

    Energy Technology Data Exchange (ETDEWEB)

    Manfredi, Riccardo; Ventriglia, Anna; Mehrabi, Sara; Boninsegna, Enrico; Pozzi Mucelli, Roberto [University of Verona, Department of Radiology, Verona (Italy); Mantovani, William [Provincial Health Services, Department of Public Health and Prevention, Trento (Italy); Zamboni, Giuseppe [University of Verona, Department of Pathology, Verona (Italy); Salvia, Roberto [University of Verona, Department of Surgery, Verona (Italy)

    2015-04-01

    To identify magnetic resonance (MR)/MR cholangiopancreatography (MRCP) imaging signs helpful in the differential diagnosis between serous cystadenomas (SCAs) and mucinous cystic neoplasms (MCNs), arising from the body/tail of the pancreas. This retrospective study had institutional review board approval and informed consent was waived. Fifty-three patients with non-communicating cystic pancreatic neoplasm of the body/tail, undergoing MR/MRCP, were included. Qualitative image analysis assessed the macroscopic pattern, number of cysts, presence of central scar, contrast enhancement of peripheral wall, and mural nodules. Quantitative analysis assessed the maximum diameter of the neoplasm, thickness of the peripheral wall, and calibre of the upstream main pancreatic duct. Histopathology results revealed that 27/53 (51 %) were SCAs, 26/53 (49 %) were MCNs. Microcystic pattern was observed in 88.2 % of SCAs and 11.8 % of MCNs; macrocystic pattern was observed in 90.5 % of MCNs and 9.5 % of SCAs (p < 0.0001). Central scar was detected in 29.6 % of SCAs and no MCNs (p = 0.003). Contrast enhancement of the peripheral wall was evident in 99.5 % of MCNs and 11.5 % of SCAs (p < 0.0001); mural nodules were depicted in 94.1 % of MCNs and 5.9 % of SCAs (p < 0.0001). Median maximum diameter was 54 mm for MCNs, 32 mm for SCAs (p = 0.001); median wall thickness was 4 mm for MCNs, 2 mm for SCAs (p < 0.0001). Macrocystic pattern, enhancement of a peripheral wall and mural nodules are suggestive of MCNs; whereas microcystic pattern, lack of peripheral wall and central scar are suggestive of SCAs. (orig.)

  12. Hg in snow cover and snowmelt waters in high-sulfide tailing regions (Ursk tailing dump site, Kemerovo region, Russia).

    Science.gov (United States)

    Gustaytis, M A; Myagkaya, I N; Chumbaev, A S

    2018-07-01

    Gold-bearing polymetallic Cu-Zn deposits of sulphur-pyrite ores were discovered in the Novo-Ursk region in the 1930s. The average content of mercury (Hg) was approximately 120 μg/g at the time. A comprehensive study of Hg distribution in waste of metal ore enrichment industry was carried out in the cold season on the tailing dump site and in adjacent areas. Mercury concentration in among snow particulate, dissolved and colloid fractions was determined. The maximal Hg content in particulate fraction from the waste tailing site ranged 230-573 μg/g. Such indices as the frequency of aerosol dust deposition events per units of time and area, enrichment factor and the total load allowed to establish that the territory of the tailing waste dump site had a snow cover highly contaminated with dust deposited at a rate of 247-480 mg/(m 2 ∙day). Adjacent areas could be considered as area with low Hg contamination rate with average deposition rate of 30 mg/(m 2 ∙day). The elemental composition of the aerosol dust depositions was determined as well, which allowed to reveal the extent of enrichment waste dispersion throughout adjacent areas. The amount of Hg entering environment with snowmelt water discharge was estimated. As a result of snowmelting, in 2014 the nearest to the dump site hydrographic network got Hg as 7.1 g with colloids and as 5880 g as particles. The results obtained allowed to assess the degree of Hg contamination of areas under the impact of metal enrichment industry. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Summary of the engineering assessment of inactive uranium mill tailings, Green River site, Green River, Utah

    International Nuclear Information System (INIS)

    1981-08-01

    Radon gas released from the 123,000 tons of tailings at the Green River site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The five alternative actions range from millsite decontamination with the addition of 3 m of stabilization cover material, to removal of the tailings to remote disposal sites and decontamination of the tailings site. Cost estimates for the five options range from about $4,300,000 for stabilization in-place, to about $9,600,000 for disposal at a distance of about 30 miles. Three principal alternatives for the reprocessing of the Green River tailings were examined: heap leaching, treatment at an existing mill, and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $1,800/lb by heap leach and $1,600/lb by conventional plant processes

  14. Mine tailings composition in a historic site: implications for ecological restoration.

    Science.gov (United States)

    Courtney, R

    2013-02-01

    Ecological restoration, using tolerant plant species and nutrient additions, is a low-cost option to decrease environmental risks associated with mine tailings. An attempt was previously made to establish such a vegetation cover on an abandoned tailings facility in Southern Ireland. Historically, the tailings site has been prone to dusting and is a potential source of contamination to the surrounding environment. The site was examined to determine the success of the previous restoration plan used to revegetate the site and to determine its suitability for further restoration. Three distinct floristic areas were identified (grassland, poor grassland and bare area) based on herbage compositions and elemental analysis. Surface and subsurface samples were taken to characterise tailings from within these areas of the tailings site. The pH of bare surface tailings (pH, 2.7) was significantly more acidic (p restoration work will employ capping with a barrier layer.

  15. Characterization of short- and long-term mechanical sensitisation following surgical tail amputation in pigs

    DEFF Research Database (Denmark)

    Di Giminiani, Pierpaolo; Edwards, Sandra A.; Malcolm, Emma M.

    2017-01-01

    Commercial pigs are frequently exposed to tail mutilations in the form of preventive husbandry procedures (tail docking) or as a result of abnormal behaviour (tail biting). Although tissue and nerve injuries are well-described causes of pain hypersensitivity in humans and in rodent animal models......, there is no information on the changes in local pain sensitivity induced by tail injuries in pigs. To determine the temporal profile of sensitisation, pigs were exposed to surgical tail resections and mechanical nociceptive thresholds (MNT) were measured in the acute (one week post-operatively) and in the long......-term (either eight or sixteen weeks post-surgery) phase of recovery. The influence of the degree of amputation on MNTs was also evaluated by comparing three different tail-resection treatments (intact, ‘short tail’, ‘long tail’). A significant reduction in MNTs one week following surgery suggests...

  16. Sharp-tailed Grouse and Pygmy Rabbit Wildlife Mitigation Project

    International Nuclear Information System (INIS)

    1992-10-01

    The Proposed Action is needed to protect and enhance shrub-steppe and riparian habitat for sharp-tailed grouse (Tympanuchus phasianellus columbianus), Pygmy rabbits (Brachylagus idahoensis), and other indigenous wildlife species. The purpose of the Proposed Action is to compensate, in part, for wildlife habitat lost from the construction of Grand Coulee Dam and the inundation of Lake Roosevelt. Bonneville Power Administration proposes to fund management agreements, conservation easements, acquisition of fee title, or a combination of these on as many as 29,000 acres in Lincoln and Douglas Counties to improve shrub-steppe and riparian habitat for sharp-tailed grouse and pygmy rabbits. The BPA also proposes to fund habitat improvements (enhancements) on project lands including existing public lands. Proposed habitat treatments would include control of grazing; planting of native trees, shrubs, forbs and grasses; protection of wetlands and streambanks; herbicide use; fire prescriptions; and wildfire suppression. Proposed management activities may include predator control, population introductions, and control of crop depredation

  17. Observations of thermal and suprathermal tail ions from WIND

    Science.gov (United States)

    Randol, B. M.; Christian, E. R.; Wilson, L. B., III

    2016-12-01

    The velocity distribution function (VDF) of solar wind protons (as well as other ion populations) is comprised of a thermal Maxwellian core and an accelerated suprathermal tail, beginning at around 1 keV in the frame co-moving with solar wind bulk velocity. The form of the suprathermal tail is a power law in phase space density, f, vs. speed, v, such that f / vγ, where γ is the power law index. This commonly observed index is of particular interest because no traditional theory predicts its existence. We need more data in order to test these theories. The general shape is of interest because it is kappa-like. We show combined observations from three different instruments on the WIND spacecraft: 3DP/PLSP, STICS, and 3DP/SST/Open. These data stretch from 102 to 107 eV in energy, encompassing both the thermal and suprathermal proton populations. We show further evidence for this kappa-like distribution and report on our progress on fitting of empirical functions to these data.

  18. Narrow head-tail radio galaxies at very high resolution

    Science.gov (United States)

    Terni de Gregory, B.; Feretti, L.; Giovannini, G.; Govoni, F.; Murgia, M.; Perley, R. A.; Vacca, V.

    2017-12-01

    Aims: Narrow-angle tailed (NAT) sources in clusters of galaxies can show on the large scale very narrow tails that are unresolved even at arcsecond resolution. These sources could therefore be classified as one-sided jets. The aim of this paper is to gain new insight into the structure of these sources, and establish whether they are genuine one-sided objects, or if they are two-sided sources. Methods: We observed a sample of apparently one-sided NAT sources at subarcsecond resolution to obtain detailed information on their structure in the nuclear regions of radio galaxies. Results: Most radio galaxies are found to show two-sided jets with sharp bends, and therefore the sources are similar to the more classical NATs, which are affected by strong projection effects. The reduced images (FITS) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/608/A58

  19. Uranium Mill Tailings Remedial Action Project 1994 environmental report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    This annual report documents the Uranium Mill Tailings Remedial Action (UMTRA) Project environmental monitoring and protection program. The UMTRA Project routinely monitors radiation, radioactive residual materials, and hazardous constituents at associated former uranium tailings processing sites and disposal sites. At the end of 1994, surface remedial action was complete at 14 of the 24 designated UMTRA Project processing sites: Canonsburg, Pennsylvania; Durango, Colorado; Grand Junction, Colorado; Green River Utah, Lakeview, Oregon; Lowman, Idaho; Mexican Hat, Utah; Riverton, Wyoming; Salt Lake City, Utah; Falls City, Texas; Shiprock, New Mexico; Spook, Wyoming, Tuba City, Arizona; and Monument Valley, Arizona. Surface remedial action was ongoing at 5 sites: Ambrosia Lake, New Mexico; Naturita, Colorado; Gunnison, Colorado; and Rifle, Colorado (2 sites). Remedial action has not begun at the 5 remaining UMTRA Project sites that are in the planning stage. Belfield and Bowman, North Dakota; Maybell, Colorado; and Slick Rock, Colorado (2 sites). The ground water compliance phase of the UMTRA Project started in 1991. Because the UMTRA Project sites are.` different stages of remedial action, the breadth of the UMTRA environmental protection program differs from site to site. In general, sites actively undergoing surface remedial action have the most comprehensive environmental programs for sampling media. At sites where surface remedial action is complete and at sites where remedial action has not yet begun, the environmental program consists primarily of surface water and ground water monitoring to support site characterization, baseline risk assessments, or disposal site performance assessments.

  20. Environmental effects on compulsive tail chasing in dogs.

    Directory of Open Access Journals (Sweden)

    Katriina Tiira

    Full Text Available Obsessive Compulsive Disorder (OCD is a neuropsychiatric disorder observed both in humans and animals. Examples of Canine Compulsive Disorder (CD include excessive tail chasing (TC, light/shadow chasing and flank sucking. We performed a questionnaire survey to investigate the characteristics of compulsive (TC and its possible associations with environmental correlates and personality in a pet population of 368 dogs from four dog breeds. We observed an early onset of TC at 3-6 months of age and a large variation in TC frequency in all breeds, with an overrepresentation of milder cases. Almost half of the TC dogs showed lowered responsiveness during bouts and displayed also other types of compulsions more often than the controls. Interestingly, dogs that received dietary supplements, especially vitamins and minerals, expressed less TC compared to dogs that did not receive any supplements. Neutered females had less TC, suggesting an influence of ovarian hormones on TC. Tail chasers were shyer and had separated earlier from their mothers than the controls. Finally, our genetic study did not find an association between TC and CDH2, a locus previously associated with the canine flank sucking compulsion. In conclusion, the early-onset and the variable nature of the repetitive behaviour, which is affected by environmental factors such as micronutrients, neutering and maternal care, share several similar components between canine and human compulsions and supports canine TC as a model for human OCD.