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1

Involvement of a cytoplasmic-tail serine cluster in urotensin II receptor internalization  

PubMed Central

Most G-protein-coupled receptors that undergo agonist-dependent internalization require the presence of specific cytoplasmic-tail residues to initiate interactions with proteins of the endocytic machinery. Here we show that the UT receptor (urotensin II receptor) undergoes internalization, and that specific serine residues of the receptor's cytoplasmic tail participate in this process. We first observed a time-dependent increase in internalization of the UT receptor expressed in COS-7 cells following binding of the agonist urotensin II. This sequestration was significantly reduced in the presence of sucrose, demonstrating that the agonist-activated UT receptor is internalized in part by clathrin-coated pits. Moreover, the sequestered receptor was co-localized in endocytic vesicles with ?-arrestin1 and ?-arrestin2. To assess whether specific regions of the receptor's cytoplasmic tail were involved in internalization, five UT receptor mutants were constructed. In four constructs the receptor's cytoplasmic tail was truncated at various positions (UT?367, UT?363, UT?350 and UT?336), and in the other four adjacent serine residues at positions 364–367 were replaced by Ala (Mut4S). Each mutant, except UT?367, demonstrated a significantly reduced internalization rate, thereby revealing the importance of specific serine residues within the cytoplasmic tail of the UT receptor for its ability to be internalized efficiently.

2004-01-01

2

Microbial communities involved in methane production from hydrocarbons in oil sands tailings.  

PubMed

Microbial metabolism of residual hydrocarbons, primarily short-chain n-alkanes and certain monoaromatic hydrocarbons, in oil sands tailings ponds produces large volumes of CH(4) in situ. We characterized the microbial communities involved in methanogenic biodegradation of whole naphtha (a bitumen extraction solvent) and its short-chain n-alkane (C(6)-C(10)) and BTEX (benzene, toluene, ethylbenzene, and xylenes) components using primary enrichment cultures derived from oil sands tailings. Clone libraries of bacterial 16S rRNA genes amplified from these enrichments showed increased proportions of two orders of Bacteria: Clostridiales and Syntrophobacterales, with Desulfotomaculum and Syntrophus/Smithella as the closest named relatives, respectively. In parallel archaeal clone libraries, sequences affiliated with cultivated acetoclastic methanogens (Methanosaetaceae) were enriched in cultures amended with n-alkanes, whereas hydrogenotrophic methanogens (Methanomicrobiales) were enriched with BTEX. Naphtha-amended cultures harbored a blend of these two archaeal communities. The results imply syntrophic oxidation of hydrocarbons in oil sands tailings, with the activities of different carbon flow pathways to CH(4) being influenced by the primary hydrocarbon substrate. These results have implications for predicting greenhouse gas emissions from oil sands tailings repositories. PMID:22894132

Siddique, Tariq; Penner, Tara; Klassen, Jonathan; Nesbø, Camilla; Foght, Julia M

2012-09-01

3

Molecular cloning and characterization of bacteriophage P2 genes R and S involved in tail completion.  

PubMed

The sequences of two previously known tail genes, R and S, of the temperate bacteriophage P2 and the sequence of an additional open reading frame (orf-30) located between S and V, were determined. Amber mutations mapping within R and S, Ram3, Ram42, Ram23, Sam75, and Sam89 were sequenced and found to be within their corresponding open reading frames. We constructed overproducing plasmids for R and S and identified these proteins by SDS-PAGE of whole-cell lysates and Coomassie blue staining. The predicted molecular masses of proteins R and S were M(r) 17,400 and 17,300, respectively, although both polypeptides migrated more slowly during gel electrophoresis than would be expected from the sequence data. orf-30 occupies the strand opposite from RS and V and is preceded by several weak potential sigma 70-RNA polymerase promoters, some of which overlap with the V promoter. A construct that had the putative orf-30 promoter region upstream of the lacZ gene produced low levels of beta-galactosidase activity in vivo. Expression from the orf-30 promoter was not stimulated by the phage P4 transcriptional activator protein, delta, which acts at all the known P2 and P4 late promoters. Insertion mutagenesis showed that orf-30 was not an essential gene for P2 growth in Escherichia coli. None of the gene or protein sequences exhibited extensive homology to sequences in the nucleic acid and protein databases. However, the R protein contains a small region homologous to one in the phage T4 tail protein gp15, which is required for T4 tails to bind heads. We propose that R and S are tail completion proteins that are essential for stable head joining. PMID:8178426

Linderoth, N A; Julien, B; Flick, K E; Calendar, R; Christie, G E

1994-05-01

4

The RNA-binding protein xCIRP2 is involved in apoptotic tail regression during metamorphosis in Xenopus laevis tadpoles.  

PubMed

Frog metamorphosis induced by thyroid hormone (TH) involves not only cell proliferation and differentiation in reconstituted organs such as limbs, but also apoptotic cell death in degenerated organs such as tails. However, the molecular mechanisms directing the TH-dependent cell fate determination remain unclear. We have previously identified from newts an RNA-binding protein (nRBP) acting as the regulator governing survival and death in germ cells during spermatogenesis. To investigate the molecular events leading the tail resorption during metamorphosis, we analyzed the expression, the functional role in apoptosis, and the regulation of xCIRP2, a frog homolog of nRBP, in tails of Xenopus laevis tadpoles. At the prometamorphic stage, xCIRP2 protein is expressed in fibroblast, epidermal, nerve, and muscular cells and localized in their cytoplasm. When spontaneous metamorphosis progressed, the level of xCIRP2 mRNA remained unchanged but the amount of the protein decreased. In organ cultures of tails at the prometamorphic stage, xCIRP2 protein decreased before their lengths shortened during TH-dependent metamorphosis. The inhibition of calpain or proteasome attenuated the TH-induced decrease of xCIRP2 protein in tails, impairing their regression. These results suggest that xCIRP2 protein is downregulated through calpain- and proteasome-mediated proteolysis in response to TH at the onset of metamorphosis, inducing apoptosis in tails and thereby degenerating them. PMID:22850217

Eto, Ko; Iwama, Tomoyuki; Tajima, Tatsuya; Abe, Shin-ichi

2012-10-01

5

Mapping Loci Associated With Tail Color and Sex Determination in the Short-Lived Fish Nothobranchius furzeri  

PubMed Central

The African fish Nothobranchius furzeri is the shortest-lived vertebrate species that can reproduce in captivity, with a median life span of 9–11 weeks for the shortest-lived strain. Natural populations of N. furzeri display differences in life span, aging biomarkers, behavior, and color, which make N. furzeri a unique vertebrate system for studying the genetic basis of these traits. We mapped regions of the genome involved in sex determination and tail color by genotyping microsatellite markers in the F2 progeny of a cross between a short-lived, yellow-tailed strain and a long-lived, red-tailed strain of N. furzeri. We identified one region linked with the yellow/red tail color that maps close to melanocortin 1 receptor (mc1r), a gene involved in pigmentation in several vertebrate species. Analysis of the segregation of sex-linked markers revealed that N. furzeri has a genetic sex determination system with males as the heterogametic sex and markedly reduced recombination in the male sex-determining region. Our results demonstrate that both naturally-evolved pigmentation differences and sex determination in N. furzeri are controlled by simple genetic mechanisms and set the stage for the molecular genetic dissection of factors underlying such traits. The microsatellite-based linkage map we developed for N. furzeri will also facilitate analysis of the genetic architecture of traits that characterize this group of vertebrates, including short life span and adaptation to extreme environmental conditions.

Valenzano, Dario Riccardo; Kirschner, Jeanette; Kamber, Roarke A.; Zhang, Elisa; Weber, David; Cellerino, Alessandro; Englert, Christoph; Platzer, Matthias; Reichwald, Kathrin; Brunet, Anne

2009-01-01

6

Experimental determination of the effect of horizontal-tail size, tail length, and vertical location on low-speed static longitudinal stability and damping pitch of a model having 45 degree sweptback wing and tail surfaces  

NASA Technical Reports Server (NTRS)

Report presents the results of an investigation conducted in the Langley stability tunnel to determine the effects of horizontal tails of various sizes and at various tail lengths (when loaded on the fuselage center line) and also the effects of vertical location of the horizontal tail relative to the wing on the low-speed static longitudinal stability and on the steady-state rotary damping in pitch for a complete-model configuration. The wing and tail surfaces had the quarter-chord lines swept back 45 degrees and had aspect ratios of 4. The results of the investigation showed that, in agreement with analytical considerations, the contribution of the horizontal tail to static longitudinal stability was related directly to the tail size and length; whereas, its contribution to damping in pitch was related directly to tail size and the square of tail length.

Lichtenstein, Jacob H

1952-01-01

7

Determination of the reaction rate coefficient of sulphide mine tailings deposited under water.  

PubMed

The efficiency of a water cover to limit dissolved oxygen (DO) availability to underlying acid-generating mine tailings can be assessed by calculating the DO flux at the tailings-water interface. Fick's equations, which are generally used to calculate this flux, require knowing the effective DO diffusion coefficient (Dw) and the reaction (consumption) rate coefficient (Kr) of the tailings, or the DO concentration profile. Whereas Dw can be accurately estimated, few studies have measured the parameter Kr for submerged sulphide tailings. The objective of this study was to determine Kr for underwater sulphide tailings in a laboratory experiment. Samples of sulphide mine tailings (an approximately 6 cm layer) were placed in a cell under a water cover (approximately 2 cm) maintained at constant DO concentration. Two tailings were studied: TA1 with high sulphide content (83% pyrite) and TA2 with low sulphide content (2.8% pyrite). DO concentration was measured with a microelectrode at various depths above and below the tailings-water interface at 1 mm intervals. Results indicate that steady-state condition was rapidly attained. As expected, a diffusive boundary layer (DBL) was observed in all cases. An iterative back-calculation process using the numerical code POLLUTEv6 and taking the DBL into account provided the Kr values used to match calculated and experimental concentration profiles. Kr obtained for tailings TA1 and TA2 was about 80 d(-1) and 6.5 d(-1), respectively. For comparison purposes, Kr obtained from cell tests on tailings TA1 was lower than Kr calculated from the sulphate production rate obtained from shake-flask tests. Steady-state DO flux at the water-tailings interface was then calculated with POLLUTEv6 using tailings characteristics Dw and Kr. For the tested conditions, DO flux ranged from 608 to 758 mg O2/m(2)/d for tailings TA1 and from 177 to 221 mg O2/m(2)/d for tailings TA2. The impact of placing a protective layer of inert material over the tailings was also investigated for tailings TA1 (with high sulphide content). A protective layer of only 5 cm reduced the DO flux into the tailings at about 5 mg/m(2)/d, compared to 608 mg O2/m(2)/d without a protective layer, or an approximately 99% reduction in flux. PMID:23906653

Awoh, Akué Sylvette; Mbonimpa, Mamert; Bussière, Bruno

2013-10-15

8

Derivation of charts for determining the horizontal tail load variation with any elevator motion  

NASA Technical Reports Server (NTRS)

The equations relating the wing and tail loads are derived for a unit elevator displacement. These equations are then converted into a nondimensional form and charts are given by which the wing- and tail-load-increment variation may be determined under dynamic conditions for any type of elevator motion and for various degrees of airplane stability. In order to illustrate the use of the charts, several examples are included in which the wing and tail loads are evaluated for a number of types of elevator motion. Methods are given for determining the necessary derivatives from results of wind-tunnel tests when such tests are available.

Pearson, Henry A

1943-01-01

9

Determination of Sample Sizes for Setting Beta-Content Tolerance Limits Controlling Both Tails of the Normal Distribution.  

National Technical Information Service (NTIS)

The problem of determining sample size for two-sided beta content tolerance intervals which control both tails of the normal distribution is investigated. The tolerance limits are defined to assure that the tail proportions do not exceed specified values ...

Y. M. Chou R. W. Mee

1984-01-01

10

Age and sex determination of juvenile band-tailed pigeons  

USGS Publications Warehouse

Captive band-tailed pigeons (Columbafasciata) were studied to document progression of molts and plumages from juvenal to adult age. Immature pigeons began the post-juvenal molt at 35 days which continued up to 340 days. The only 3 plumage characters useful for identification and estimation of age were presence of juvenal lesser, middle, and greater secondary coverts, juvenal secondaries, and juvenal primaries. While juvenal primaries were still present, hatching dates could be estimated up to 252 days (N = 84). Secondary feather presence and molt stage could be used to identify juvenile pigeons for more than 340 days (N = 24). Using coloration of the crown and breast feathers, 96 percent of the immature pigeons examined (106 of 110) at 80 days of age were classified accurately as to sex.

White, J.A.; Braun, C.E.

1978-01-01

11

Endogenous opioids are involved in morphine and dipyrone analgesic potentiation in the tail flick test in rats.  

PubMed

The combined administration of low doses of opiates with non-steroidal anti-inflammatory drugs can produce additive or supra-additive analgesic effects while reducing unwanted side effects. We have recently reported that co-administration of morphine with dipyrone (metamizol) produces analgesic potentiation both in naïve and in morphine-tolerant rats. The purpose of this work was to determine the role of opioids on the acute potentiation observed between morphine and dipyrone i.v. in the rat tail flick test. To do this, two experiments were done. In the first one, naloxone was administered 10 min before morphine (3.1 mg/kg), dipyrone (600 mg/kg) or their combination at the same doses. Control animals received saline instead of naloxone. In the second experiment, naloxone (or saline) was given 2 min after reaching the maximal peak effect with each individual analgesic treatment. When naloxone was i.v. administered prior to analgesics, it completely blocked morphine effects, partially prevented morphine/dipyrone antinociception and delayed dipyrone-induced nociception. At 3.1 mg/kg, naloxone produced an increased nociception. When naloxone was given after analgesics, it dose-dependently blocked the effects of morphine alone and in combination with dipyrone but with different potency in each case. As to dipyrone, naloxone delayed the time to antinociceptive peak effect. Taken together, these results support the notion that endogenous opioids are involved in the analgesic potentiation observed with the combination of morphine plus dipyrone. PMID:16914138

Hernández-Delgadillo, Gloria P; Cruz, Silvia L

2006-09-28

12

Alpha-1D adrenoceptors are involved in reserpine-induced supersensitivity of rat tail artery  

PubMed Central

We examined reserpine-induced chemical denervation supersensitivity with special reference to alpha-1 adrenoceptor (AR) subtypes. Chronic treatment with reserpine for 2 weeks depleted noradrenaline in the tail artery and spleen of rats. Noradrenaline in the thoracic aorta was negligible before and after reserpine treatment. The treatment with reserpine produced supersensitivity in the contractile responses of the rat tail artery to phenylephrine, 5-HT and KCl, resulting in leftward shift of concentration–response curves (11.6-, 2.5- and 1.1-fold at EC50 value, respectively). These results suggest a predominant sensitization of the alpha-1 AR-mediated response by reserpine treatment. BMY 7378 at a concentration (30 nM) specific for blocking the alpha-1D AR subtype, but not KMD-3213 at a concentration (10 nM) selective for blocking the alpha-1A AR subtype, inhibited the supersensitivity of the phenylephrine-induced response in the reserpine-treated artery. On the other hand, the response to phenylephrine in reserpine-untreated artery was selectively inhibited by the same concentration of KMD-3213, but not by BMY 7378. Prazosin, a subtype-nonselective antagonist, blocked the responses to phenylephrine with the same potency, regardless of reserpine treatment. In the thoracic aorta and spleen, no supersensitivity was produced in the responses to phenylephrine by reserpine treatment. In a tissue segment-binding study using [3H]-prazosin, the total density and affinity of alpha-1 ARs in the rat tail artery were not changed by treatment with reserpine. However, alpha-1D AR with high affinity for BMY 7378 was significantly detected in reserpine-treated tail artery, in contrast to untreated artery. Decreases in alpha-1A AR with high affinity for KMD-3213 and alpha-1B AR with low affinities for KMD-3213 and BMY 7378 were also estimated in reserpine-treated tail artery. Alpha-1D AR mRNA in rat tail artery increased to three-folds by reserpine treatment, whereas the levels of alpha-1A and 1B mRNAs were not significantly changed. The present results suggest that chronic treatment with reserpine affects the expression of alpha-1 AR subtypes of rat tail artery and that the induction of alpha-1D ARs with high affinity for catecholamines is in part associated with reserpine-induced supersensitivity.

Taki, Naoyuki; Tanaka, Takashi; Zhang, Li; Suzuki, Fumiko; Israilova, Malika; Taniguchi, Takanobu; Hiraizumi-Hiraoka, Yasuko; Shinozuka, Kazumasa; Kunitomo, Masaru; Muramatsu, Ikunobu

2004-01-01

13

A Dibasic Motif in the Tail of a Class XIV Apicomplexan Myosin Is an Essential Determinant of Plasma Membrane Localization  

PubMed Central

Obligate intracellular parasites of the phylum Apicomplexa exhibit gliding motility, a unique form of substrate-dependent locomotion essential for host cell invasion and shown to involve the parasite actin cytoskeleton and myosin motor(s). Toxoplasma gondii has been shown to express three class XIV myosins, TgM-A, -B, and -C. We identified an additional such myosin, TgM-D, and completed the sequences of a related Plasmodium falciparum myosin, PfM-A. Despite divergent structural features, TgM-A purified from parasites bound actin in an ATP-dependent manner. Isoform-specific antibodies revealed that TgM-A and recombinant mycTgM-A were localized right beneath the plasma membrane, and subcellular fractionation indicated a tight membrane association. Recombinant TgM-D also had a peripheral although not as sharply defined localization. Truncation of their respective tail domains abolished peripheral localization and tight membrane association. Conversely, fusion of the tails to green fluorescent protein (GFP) was sufficient to confer plasma membrane localization and sedimentability. The peripheral localization of TgM-A and of the GFP-tail fusion did not depend on an intact F-actin cytoskeleton, and the GFP chimera did not localize to the plasma membrane of HeLa cells. Finally, we showed that the specific localization determinants were in the very C terminus of the TgM-A tail, and site-directed mutagenesis revealed two essential arginine residues. We discuss the evidence for a proteinaceous plasma membrane receptor and the implications for the invasion process.

Hettmann, Christine; Herm, Angelika; Geiter, Ariane; Frank, Bernd; Schwarz, Eva; Soldati, Thierry; Soldati, Dominique

2000-01-01

14

Sorption of Heavy Metals on a Coal BeneficiationTailing Material. I: Characterization and Mechanisms Involved  

Microsoft Academic Search

A Brazilian coal jigging refuse was studied as a sorbing material for heavy metal ions such as copper, zinc and nickel. This refuse was characterized in terms of its petrographic composition and surface properties. Metal ions uptake mechanism involved was studied through sorption isotherms, scanning electron photomicrographs scanning electron spectral analysis and zeta potential measurements. Sorption isotherms showed saturation values

L. A. FÈRIS; J. A. FLORES; I. A. SCHNEIDER; J. RUBIO

2000-01-01

15

A minimally invasive method for gender determination in the prehensile-tailed porcupine (Coendou prehensilis).  

PubMed

Prehensile-tailed porcupines (Coendou prehensilis), like other rodents, lack external sexual traits, making it difficult to non-invasively determine their gender. By exploiting genetic differences between the X and the Y chromosome, we developed a simple genetic test to determine the gender of Coendous from shed quills. We Sanger sequenced a short portion (195?bp) of the zinc finger protein gene of known male (XY) Coendous to identify positions that are polymorphic between the X and Y chromosomes at this locus. By directly sequencing this fragment, we were able to correctly determine (confirmed via anatomical sexing) the gender of male and female Coendous by the presences or absence of polymorphisms in the resulting chromatograms. This assay is simple, quick and is applicable to other porcupine species. PMID:23447467

Woc-Colburn, Ana Margarita; Murray, Suzan; Lock, Justin; Dragoo, Jerry W; Guglielmo, Dell; Maldonado, Jesús E

2013-01-01

16

CNS cell groups projecting to sympathetic outflow of tail artery: neural circuits involved in heat loss in the rat  

Microsoft Academic Search

In the rat, ?20% of total body heat-loss occurs by sympathetically mediated increases in blood flow through an elaborate system of arteriovenous anastomoses in the skin of its tail. In this study, the CNS cell groups that regulate this sympathetic outflow were identified by the viral transneuronal labeling method. Pseudorabies virus was injected into the wall of the ventral tail

Julia E Smith; Arthur S. P Jansen; Michael P Gilbey; Arthur D Loewy

1998-01-01

17

Determinants of Pair-Living in Red-Tailed Sportive Lemurs (Lepilemur ruficaudatus)  

PubMed Central

Pair-living and a monogamous mating strategy are rare and theoretically unexpected among mammals. Nevertheless, about 10% of primate species exhibit such a social system, which is difficult to explain in the absence of paternal care. In this study, we investigated the two major hypotheses proposed to explain the evolution of monogamy in mammals, the female defence hypothesis (FDH) and the resource defence hypothesis (RDH), in red-tailed sportive lemurs (Lepilemur ruficaudatus), a nocturnal primate from Madagascar. We analysed behavioural data from eight male–female pairs collected during a 24-mo field study to illuminate the determinants of pair-living in this species. Male and female L. ruficaudatus were found to live in dispersed pairs, which are characterised by low cohesion and low encounter rates within a common home range. Social interactions between pair partners were mainly agonistic and characterised by a complete absence of affiliative interactions – body contact was only observed during mating. During the short annual mating season, males exhibited elevated levels of aggression towards mates, as well as extensive mate guarding and increased locomotor activity. In addition, males were exclusively responsible for the maintenance of proximity between pair partners during this period, and they defended their territories against neighbouring males but not against females. Together, these results point towards the importance of female defence in explaining pair-living in L. ruficaudatus. We discuss the spatial and temporal distribution of receptive females in relation to the female defence strategies of males and suggest possible costs that prevent male red-tailed sportive lemurs from defending more than one female.

Hilgartner, Roland; Fichtel, Claudia; Kappeler, Peter M; Zinner, Dietmar

2012-01-01

18

The Kinetics of the Thermal Denaturation of Collagen in Unrestrained Rat Tail Tendon Determined by Differential Scanning Calorimetry  

Microsoft Academic Search

This paper shows that the position and shape of the denaturation endothem of collagen fibrils are governed by the kinetics of an irreversible rate process. This was proved by measuring the rate of denaturation in rat tail tendons held isothermally at different temperatures, thereby determining rate constant characteristics such as the activation enthalpy and entropy and predicting endotherm position and

Christopher A. Miles; Thengiz V. Burjanadze; Allen J. Bailey

1995-01-01

19

Chemical extractions applied to the determination of radium speciation in uranium mill tailing: Study of different reagents  

Microsoft Academic Search

Sequential extraction procedures are widely used to determine trace elements speciation in soils or sediments in order to\\u000a estimate the contaminants availability for plants uptake or migration towards ground waters. The aim of this work was to apply\\u000a such an approach to determine radium speciation in uranium mill tailing in which the composition of the solid phase is close\\u000a to

I. Yousfi; J. Bole; O. Geiss

1999-01-01

20

A conserved region in the tail domain of vimentin is involved in its assembly into intermediate filaments.  

PubMed

Although the head and rod domains of intermediate filament (IF) proteins are known to play significant roles in filament assembly, the role of the tail domain in this function is unclear and the available information supports contradictory conclusions. We examined this question by comparing transfection of the same cDNA constructs, encoding vimentins with modified tail domains, into cell lines that do and do not contain endogenous IF proteins. By this approach, we were able to distinguish between the ability of a mutant IF protein to initiate assembly de novo, from that of incorporating into existing filament networks. Vimentins with modifications at or near a highly conserved tripeptide, arg-asp-gly (RDG), of the tail domain incorporated into existing IF networks in vimentin-expressing (vim+) cells, but were assembly-incompetent in cells that did not express IF proteins (vim-). The failure of the RDG mutant vimentins to assemble into filament arrays in vim- cells was reversible by re-introducing a wild-type vimentin cDNA, whereupon both wild-type and mutant vimentins coassembled into one and the same IF network. We conclude that the function of the tail domain of type III IF proteins, and possibly of keratins K8 and K18, in IF assembly is distinct from those of other domains; a region encompassing the RDG tripeptide appears to be important in the assembly process. PMID:7954854

Makarova, I; Carpenter, D; Khan, S; Ip, W

1994-01-01

21

Structures and Interaction Analyses of Integrin ?M?2 Cytoplasmic Tails*  

PubMed Central

Integrins are heterodimeric (? and ? subunits) signal transducer proteins involved in cell adhesions and migrations. The cytosolic tails of integrins are essential for transmitting bidirectional signaling and also implicated in maintaining the resting states of the receptors. In addition, cytosolic tails of integrins often undergo post-translation modifications like phosphorylation. However, the consequences of phosphorylation on the structures and interactions are not clear. The leukocyte-specific integrin ?M?2 is essential for myeloid cell adhesion, phagocytosis, and degranulation. In this work, we determined solution structures of the myristoylated cytosolic tail of ?M and a Ser phosphorylated variant in dodecylphosphocholine micelles by NMR spectroscopy. Furthermore, the interactions between non-phosphorylated and phosphorylated ?M tails with ?2 tail were investigated by NMR and fluorescence resonance energy transfer (FRET). The three-dimensional structures of the 24-residue cytosolic tail of ?M or phosphorylated ?M are characterized by an N-terminal amphipathic helix and a loop at the C terminus. The residues at the loop are involved in packing interactions with the hydrophobic face of the helix. 15N-1H heteronuclear single quantum coherence experiments identified residues of ?M and ?2 tails that may be involved in the formation of a tail-tail heterocomplex. We further examined interactions between myristoylated ?2 tail in dodecylphosphocholine micelles with dansylated ?M tail peptides by FRET. These studies revealed enhanced interactions between ?M or phosphorylated ?M tails with ?2 tail with Kd values ?5.2 ± 0.6 and ?4.4 ± 0.7 ?m, respectively. Docked structures of tail-tail complexes delineated that the ?M/?2 interface at the cytosolic region could be sustained by a network of polar interactions, ionic interactions, and/or hydrogen bonds.

Chua, Geok-Lin; Tang, Xiao-Yan; Amalraj, Monalisa; Tan, Suet-Mien; Bhattacharjya, Surajit

2011-01-01

22

Morphogenesis of the T4 tail and tail fibers  

PubMed Central

Remarkable progress has been made during the past ten years in elucidating the structure of the bacteriophage T4 tail by a combination of three-dimensional image reconstruction from electron micrographs and X-ray crystallography of the components. Partial and complete structures of nine out of twenty tail structural proteins have been determined by X-ray crystallography and have been fitted into the 3D-reconstituted structure of the "extended" tail. The 3D structure of the "contracted" tail was also determined and interpreted in terms of component proteins. Given the pseudo-atomic tail structures both before and after contraction, it is now possible to understand the gross conformational change of the baseplate in terms of the change in the relative positions of the subunit proteins. These studies have explained how the conformational change of the baseplate and contraction of the tail are related to the tail's host cell recognition and membrane penetration function. On the other hand, the baseplate assembly process has been recently reexamined in detail in a precise system involving recombinant proteins (unlike the earlier studies with phage mutants). These experiments showed that the sequential association of the subunits of the baseplate wedge is based on the induced-fit upon association of each subunit. It was also found that, upon association of gp53 (gene product 53), the penultimate subunit of the wedge, six of the wedge intermediates spontaneously associate to form a baseplate-like structure in the absence of the central hub. Structure determination of the rest of the subunits and intermediate complexes and the assembly of the hub still require further study.

2010-01-01

23

Estimation of the maximum angle of sideslip for determination of vertical-tail loads in rolling maneuvers  

NASA Technical Reports Server (NTRS)

Report includes the National Advisory Committee for Aeronautics Technical Reports 1135 through 1157. Recent experiences have indicated that angles of sideslip in rolling maneuvers may be critical in the design of vertical tails for current research airplanes having weight distributed mainly along the fuselage. Previous investigations have indicated the seriousness of the problem for the World War II type of airplane. This report presents some preliminary calculations for airplanes of current design, particularly with weight distributed primarily along the fuselage. The results of this study indicate that existing simplified expressions for calculating maximum sideslip angles to determine the vertical-tail loads in rolling maneuvers are not generally applicable to airplanes of current design.

Stone, Ralph W , Jr

1953-01-01

24

Density and distribution of cutaneous sensilla on tails of leopard geckos (Eublepharis macularius) in relation to caudal autotomy.  

PubMed

The lizard tail is well known for its ability to autotomize and regenerate. Physical contact of the tail by a predator may induce autotomy at the location at which the tail is grasped, and upon detachment the tail may undergo violent, rapid, and unpredictable movements that appear to be, to some degree, regulated by contact with the physical environment. Neither the mechanism by which tail breakage at a particular location is determined, nor that by which environmental feedback to the tail is received, are known. It has been suggested that mechanoreceptors (sensilla) are the means of mediation of such activities, and reports indicate that the density of sensilla on the tail is high. To determine the feasibility that mechanoreceptors are involved in such phenomena, we mapped scale form and the size, density, distribution, and spacing of sensilla on the head, body, limbs, and tail of the leopard gecko. This species has a full complement of autotomy planes along the length of the tail, and the postautotomic behavior of its tail has been documented. We found that the density of sensilla is highest on the tail relative to all other body regions examined; a dorsoventral gradient of caudal sensilla density is evident on the tail; sensilla are more closely spaced on the dorsal and lateral regions of the tail than elsewhere and are carried on relatively small scales; and that the whorls of scales on the tail bear a one to one relationship with the autotomy planes. Our results are consistent with the hypotheses of sensilla being involved in determining the site at which autotomy will occur, and with them being involved in the mediation of tail behavior following autotomy. These findings open the way for experimental neurological investigations of how autotomy is induced and how the detached tail responds to external environmental input. J. Morphol. 275:961-979, 2014. © 2014 Wiley Periodicals, Inc. PMID:24643900

Russell, Anthony P; Lai, Erica K; Lawrence Powell, G; Higham, Timothy E

2014-09-01

25

Uranium-mill-tailings conditioning technology  

Microsoft Academic Search

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°C) to radically alter the structure of tailings. This thermal stabilization at 1200°C reduced radon emanation power for tailings sands

D. R. Dreesen; E. J. Cokal; P. D. OBrien; E. F. Thode; L. E. Wangen; J. M. Williams

1982-01-01

26

Determinants of Parental Involvement in Early Schooling: Evidence from Japan  

ERIC Educational Resources Information Center

This study examined how demographic and psychological factors shape the involvement of Japanese mothers in their children's education. The five demographic variables studied were family income, maternal education, family size, mothers' employment status, and sex of the child. Three forms of parental cognition were also studied: mothers'…

Holloway, Susan D.; Yamamoto, Yoko; Suzuki, Sawako; Mindnich, Jessica D.

2008-01-01

27

Determinants of Communication Network Involvement: Connectedness and Integration.  

ERIC Educational Resources Information Center

Developed structural equation models of involvement in communication networks in organizations for communication network connectedness and for network integration. A questionnaire was administered to members of a naval training facility (N=125). Models showed acceptable goodness-of-fit for the connectedness model and excellent goodness-of-fit for…

Monge, Peter R.; And Others

1983-01-01

28

Animal Tails  

NSDL National Science Digital Library

Call it tail envy. With only a vestigial nub to show for ourselves, perhaps it's no wonder that animal tails capture our attention. The following Web sites present some of the more interesting tails to be found in the animal kingdom. The first Web site contains a recent article from Discovery News describing new findings that at least one species of scorpion produces two distinct types of tail venom, which have completely different effects on their victims (1). The next site from Singapore Zoological Gardens introduces the cebids (our New World monkey cousins), some of which have amazing prehensile tails that are used like a fifth limb (2). The rattlesnake is another famously-tailed creature, highlighted in the following site from the Arizona-Sonora Desert Museum (3). The site covers the main aspects of rattlesnake natural history, including a section on how the rattle forms. The Great Plains Nature Center in Wichita, Kansas, offers a Web page devoted to the beaver, including tail trivia and an audio clip of a resident beaver surprised in his den at the Kansas Wildlife Exhibit (4). Anyone who has witnessed the freakishly fascinating spectacle of a gecko leaving its tail behind to distract a would-be predator will appreciate this brief bio of the Tokay gecko, presented by ReptileCenter.com, the Herpetologist's Portal (5). Stacy's Wag'N'Train -- offering dog-training classes in San Jose, California -- provides this online guide to dog body language, which would have a very limited vocabulary without the tail (6). So, how did the peacock get its tail? It's a simple question that has driven zoologists crazy for over a century. The next Web site (7) contains an in-depth article on the subject from the Independent (London), offered through National Geographic News. And finally, the bizarre gulper eel -- able to tie its tail in several knots -- gets is own Web page on Pangea, the Web server for the Department of Educational Leadership and Technology at Southeastern Louisiana University (8). This deep-sea curiosity uses its bioluminescent tail tip to lure hapless prey into its impossibly gigantic mouth.

Sohmer, Rachel.

2003-01-01

29

8 CFR 1208.30 - Credible fear determinations involving stowaways and applicants for admission found inadmissible...  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Credible fear determinations involving stowaways and applicants...ASYLUM AND WITHHOLDING OF REMOVAL Credible Fear of Persecution § 1208.30 Credible fear determinations involving stowaways and...

2009-01-01

30

8 CFR 208.30 - Credible fear determinations involving stowaways and applicants for admission found inadmissible...  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Credible fear determinations involving stowaways and applicants...FOR ASYLUM AND WITHHOLDING OF REMOVAL Credible Fear of Persecution § 208.30 Credible fear determinations involving stowaways and...

2009-01-01

31

8 CFR 1208.30 - Credible fear determinations involving stowaways and applicants for admission found inadmissible...  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Credible fear determinations involving stowaways and applicants...ASYLUM AND WITHHOLDING OF REMOVAL Credible Fear of Persecution § 1208.30 Credible fear determinations involving stowaways and...

2010-01-01

32

8 CFR 208.30 - Credible fear determinations involving stowaways and applicants for admission found inadmissible...  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Credible fear determinations involving stowaways and applicants...FOR ASYLUM AND WITHHOLDING OF REMOVAL Credible Fear of Persecution § 208.30 Credible fear determinations involving stowaways and...

2010-01-01

33

Tail planes  

NASA Technical Reports Server (NTRS)

This report presents methods by which the cells of large commercial airplanes may be reduced. The tail of large airplanes represent an area where considerable improvement in weight and size reduction can be attained.

Constantin, L

1926-01-01

34

Ferulic acid exerts antidepressant-like effect in the tail suspension test in mice: evidence for the involvement of the serotonergic system.  

PubMed

Ferulic acid (4-hydroxy-3-methoxycinnamic acid) is a phenolic compound present in several plants with claimed beneficial effects in prevention and treatment of disorders linked to oxidative stress and inflammation. In this study, we aimed to verify the possible antidepressant-like effect of acute oral administration of ferulic acid in the forced swimming test (FST) and tail suspension test (TST) in mice. Additionally, the mechanisms involved in the antidepressant-like action and the effects of the association of ferulic acid with the antidepressants fluoxetine, paroxetine, and sertraline in the TST were investigated. Ferulic acid produced an antidepressant-like effect in the FST and TST (0.01-10 mg/kg, p.o.), without accompanying changes in ambulation. The pretreatment of mice with WAY100635 (0.1 mg/kg, s.c., a selective 5-HT(1A) receptor antagonist) or ketanserin (5 mg/kg, i.p., a 5-HT(2A) receptor antagonist) was able to reverse the anti-immobility effect of ferulic acid (0.01 mg/kg, p.o.) in the TST. The combination of fluoxetine (5 mg/kg, p.o.), paroxetine (0.1 mg/kg, p.o.) or sertraline (1 mg/kg, p.o.) with a sub-effective dose of ferulic acid (0.001 mg/kg, p.o.) produced a synergistic antidepressant-like effect in the TST, without causing hyperlocomotion in the open-field test. Taken together, these results demonstrate that ferulic acid exerts antidepressant-like effect in the FST and TST in mice through modulation of the serotonergic system. PMID:22266492

Zeni, Ana Lúcia B; Zomkowski, Andréa Dias E; Maraschin, Marcelo; Rodrigues, Ana Lúcia S; Tasca, Carla I

2012-03-15

35

Tail Buffeting  

NASA Technical Reports Server (NTRS)

An approximate theory of buffeting is here presented, based on the assumption of harmonic disturbing forces. Two cases of buffeting are considered: namely, for a tail angle of attack greater and less than the stalling angle, respectively. On the basis of the tests conducted and the results of foreign investigators, a general analysis is given of the nature of the forced vibrations the possible load limits on the tail, and the methods of elimination of buffeting.

Abdrashitov, G.

1943-01-01

36

Uranium-Mill-Tailings Conditioning Technology.  

National Technical Information Service (NTIS)

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 ...

D. R. Dreesen E. J. Cokal P. D. O'Brien E. F. Thode L. E. Wangen

1982-01-01

37

Uranium Mill Tailings Remedial Action Technology.  

National Technical Information Service (NTIS)

The uranium milling process involves the hydrometallurgical extraction of uranium from ores and the resultant generation of large quantities of waste referred to as tailings. Uranium mill tailings have been identified as requiring remediation because they...

J. N. Hartley G. W. Gee

1984-01-01

38

Using behavior theory to investigate individual-level determinants of employee involvement in TQM  

Microsoft Academic Search

Although much has been written about total quality management and employee involvement, little attention has been paid to individual-level determinants of employee's involvement in total quality management. The use of behaviour theory to formulate propositions regarding the determinants is especially scare in the total quality management and employee involvement literature. The major objective of the present research was to isolate

Zhongjun Tang; Xiaohong Chen; Zhengwen Wu

2010-01-01

39

Neurophysiological determinants of theoretical concepts and mechanisms involved in pacing.  

PubMed

Fatigue during prolonged exercise is often described as an acute impairment of exercise performance that leads to an inability to produce or maintain a desired power output. In the past few decades, interest in how athletes experience fatigue during competition has grown enormously. Research has evolved from a dominant focus on peripheral causes of fatigue towards a complex interplay between peripheral and central limitations of performance. Apparently, both feedforward and feedback mechanisms, based on the principle of teleoanticipation, regulate power output (e.g., speed) during a performance. This concept is called 'pacing' and represents the use of energetic resources during exercise, in a way such that all energy stores are used before finishing a race, but not so far from the end of a race that a meaningful slowdown can occur.It is believed that the pacing selected by athletes is largely dependent on the anticipated exercise duration and on the presence of an experientially developed performance template. Most studies investigating pacing during prolonged exercise in ambient temperatures, have observed a fast start, followed by an even pace strategy in the middle of the event with an end sprint in the final minutes of the race. A reduction in pace observed at commencement of the event is often more evident during exercise in hot environmental conditions. Further, reductions in power output and muscle activation occur before critical core temperatures are reached, indicating that subjects can anticipate the exercise intensity and heat stress they will be exposed to, resulting in a tactical adjustment of the power output. Recent research has shown that not only climatic stress but also pharmacological manipulation of the central nervous system has the ability to cause changes in endurance performance. Subjects seem to adapt their strategy specifically in the early phases of an exercise task. In high-ambient temperatures, dopaminergic manipulations clearly improve performance. The distribution of the power output reveals that after dopamine reuptake inhibition, subjects are able to maintain a higher power output compared with placebo. Manipulations of serotonin and, especially, noradrenaline, have the opposite effect and force subjects to decrease power output early in the time trial. Interestingly, after manipulation of brain serotonin, subjects are often unable to perform an end sprint, indicating an absence of a reserve capacity or motivation to increase power output. Taken together, it appears that many factors, such as ambient conditions and manipulation of brain neurotransmitters, have the potential to influence power output during exercise, and might thus be involved as regulatory mechanisms in the complex skill of pacing. PMID:23456493

Roelands, Bart; de Koning, Jos; Foster, Carl; Hettinga, Floor; Meeusen, Romain

2013-05-01

40

Magnetic Merging Locations Deduced from: Slow-Mode Shock Orientation Determinations, Boundary Layer Wave Intensities and Energetic Ion Velocity Dispersion in the Distant Geomagnetic Tail  

NASA Technical Reports Server (NTRS)

Several techniques will be used to determine the location of the magnetic reconnection in the distant geomagnetic tail using the ISEE-3. Techniques to be used are calculated wave-particle scattering time, plasmoid source location (if a plasmoid is found), analysis of the magnetic field geometry and slow-mode shock orientation, and examination of the magnetic field Bz components and plasma bulk speeds.

Ho, C. M.; Tsurutani, B. T.; Smith, E. J.; Murphy, N.

1995-01-01

41

Tank tests to determine the effect on planing-tail hulls of varying length, width, and plan-form taper of afterbody  

NASA Technical Reports Server (NTRS)

Tests were conducted in Langley Tank no. 2 on models of an unconventional flying-boat hull called a planing-tail hull to determine the effects on resistance of varying a number of afterbody parameters. The effects of varying length, width, and plan-form taper of the afterbody are presented. Tests were made with afterbodies of two widths, two lengths, and two tapers. In the tests the depth of step and the angle of afterbody keel were held constant.(author)

Dawson, John R; Walter, Robert C; Hay, Elizabeth S

1946-01-01

42

Severe neural tube defects in the loop-tail mouse result from mutation of Lpp1, a novel gene involved in floor plate specification  

Microsoft Academic Search

Neural tube defects (NTD) are clinically important congenital malformations whose molecular mecha- nisms are poorly understood. The loop-tail ( Lp) mutant mouse provides a model for the most severe NTD, craniorachischisis, in which the brain and spinal cord remain open. During a positional cloning approach, we have identified a mutation in a novel gene, Lpp1, in the Lp mouse, providing

Jennifer N. Murdoch; Kit Doudney; Caroline Paternotte; Andrew J. Copp; Philip Stanier

2001-01-01

43

How regenerating lymphatics function: lessons from lizard tails.  

PubMed

Rational treatment of lymphoedema may be improved in the future with a better understanding of the physiological processes involved in the regeneration of new lymphatic vessels (lymphangiogenesis). Many lizard species undergo tail autotomy as a predator escape response and subsequently regenerate nonlymphoedematous tails. Such species may offer novel models for examining lymphangiogenesis. In this lymphoscintigraphic evaluation, three radioactive tracers were employed, (99m)Tc-antimony trisulphide colloid (approximately 10 nm diameter), (99m)Tc-tin fluoride colloid (approximately 2,000 nm; (99m)Tc-TFC), and (99m)Tc-diethylenetriaminepentaacetic acid (soluble; (99m)Tc-DTPA), to examine lymphatic function in regenerating tails of the Australian marbled gecko, Christinus marmoratus. Rate of local clearance and velocity of migration were determined in geckos with original tails and at 6, 9, 12, and >24 weeks after autotomy. In original-tailed geckos, the smaller radiocolloid was cleared to a greater extent and had a faster lymph velocity than in geckos with regenerated tails. The same parameters measured for larger particles were greater in early regeneration than later. (99m)Tc-TFC did not migrate from the injection site in fully regenerated and original gecko tails, which indicates that larger particles are increasingly impeded as tail regeneration progresses. Soluble (99m)Tc-DTPA diffused from the injection site extremely rapidly via venous capillaries in all tails, confirming that the slower clearance of the colloids is solely via the lymphatics. Differences in clearance and lymph velocity between differently sized colloids throughout tail regeneration may be influenced by changes in surrounding tissue structure density and the lymphatic vessel porosity. PMID:17441203

Blacker, Helen A; Tsopelas, Chris; Orgeig, Sandra; Daniels, Christopher B; Chatterton, Barry E

2007-01-01

44

On Tail Biting Convolutional Codes  

Microsoft Academic Search

In this paper, we introduce generalized tail biting encoding as a means to ameliorate the rate deficiency caused by zero-tail convolutional encoding. This technique provides an important link between quasi-cyclic block and convolutional codes. Optimum and suboptimum decoding algorithms for these codes are described and their performance determined by analytical and simulation techniques.

H. H. Ma; J. Wolf

1986-01-01

45

Comet C/2011 W3 (Lovejoy): Orbit Determination, Outbursts, Disintegration of Nucleus, Dust-tail Morphology, and Relationship to New Cluster of Bright Sungrazers  

NASA Astrophysics Data System (ADS)

We describe the physical and orbital properties of C/2011 W3. After surviving perihelion passage, the comet was observed to undergo major physical changes. The permanent loss of the nuclear condensation and the formation of a narrow spine tail were observed first at Malargue, Argentina, on December 20 and then systematically at Siding Spring, Australia. The process of disintegration culminated with a terminal fragmentation event on December 17.6 UT. The postperihelion dust tail, observed for ~3 months, was the product of activity over <2 days. The nucleus' breakup and crumbling were probably caused by thermal stress due to the penetration of the intense heat pulse deep into the nucleus' interior after perihelion. The same mechanism may be responsible for cascading fragmentation of sungrazers at large heliocentric distances. The delayed response to the hostile environment in the solar corona is at odds with the rubble-pile model, since the residual mass of the nucleus, estimated at ~1012 g (equivalent to a sphere 150-200 m across) just before the terminal event, still possessed nontrivial cohesive strength. The high production rates of atomic oxygen, observed shortly after perihelion, are compatible with a subkilometer-sized nucleus. The spine tail—the product of the terminal fragmentation—was a synchronic feature, whose brightest part contained submillimeter-sized dust grains, released at velocities of up to 30 m s-1. The loss of the nuclear condensation prevented an accurate orbital-period determination by traditional techniques. Since the missing nucleus must have been located on the synchrone, whose orientation and sunward tip have been measured, we compute the astrometric positions of this missing nucleus as the coordinates of the points of intersection of the spine tail's axis with the lines of forced orbital-period variation, derived from the orbital solutions based on high-quality preperihelion astrometry from the ground. The resulting orbit gives 698 ± 2 yr for the osculating orbital period, showing that C/2011 W3 is the first member of the expected new, 21st-century cluster of bright Kreutz-system sungrazers, whose existence was predicted by these authors in 2007. From the spine tail's evolution, we determine that its measured tip, populated by dust particles 1-2 mm in diameter, receded antisunward from the computed position of the missing nucleus. The bizarre appearance of the comet's dust tail in images taken only hours after perihelion with the coronagraphs on board the SOHO and STEREO spacecraft is readily understood. The disconnection of the comet's head from the tail released before perihelion and an apparent activity attenuation near perihelion have a common cause—sublimation of all dust at heliocentric distances smaller than about 1.8 solar radii. The tail's brightness is strongly affected by forward scattering of sunlight by dust. From an initially broad range of particle sizes, the grains that were imaged the longest had a radiation-pressure parameter ? ~= 0.6, diagnostic of submicron-sized silicate grains and consistent with the existence of the dust-free zone around the Sun. The role and place of C/2011 W3 in the hierarchy of the Kreutz system and its genealogy via a 14th-century parent suggest that it is indirectly related to the celebrated sungrazer X/1106 C1, which, just as the first-generation parent of C/2011 W3, split from a common predecessor during the previous return to perihelion.

Sekanina, Zdenek; Chodas, Paul W.

2012-10-01

46

Safety of Tailings Dams  

NSDL National Science Digital Library

Contains information on different aspects of tailings dams; tailings dam properties, disasters, failure modes, slurry waves, stability analysis, and safe tailings disposal. Also includes a slope stability calculator and a tailings flow slide calculator.

2008-08-25

47

Environmentally safe design of tailing dams for the management of iron ore tailings in Indian context.  

PubMed

The need for the disposal of iron ore tailings in an enviornmentally firiendly manner is of great concern. This paper investigates the soil engineering properties for the construction of iron ore tailing dam, its foundation, construction materials and design data used for the construction analysis of the tailing dam. Geophysical investigations were carried out to establish the bedrock below the spillway. A computer programme taking into account the Swedish Slip Circle Method of analysis was used in the stability analysis of dam. It also focuses on the charactierstics of the tailings reponsible for the determination of optimum size of tailing pond for the containment of the tailings. The studies on the settling characteristics of tailings indicate much less area in comparison to the area provided in the existing tailing ponds in India. In the proposed scheme, it is suggested to provide an additional unit of sedimentation tank before the disposal of tailings to the tailing pond. PMID:17051916

Ghose, Mrinal K; Sen, P K

2005-10-01

48

Colonization of mine tailings by marine invertebrates  

Microsoft Academic Search

An experiment was conducted to determine if a tailings substrate would inhibit recolonization of benthic macrofauna upon closure of a submarine tailings disposal (STD) operation. Trays of defaunated marine sediment, serving as a reference, and trays of tailings from a proposed gold mine were placed at 21 m depth on the ocean floor to allow colonization via settlement from the

E. R Kline; M. S Stekoll

2001-01-01

49

Innovativeness and Involvement as Determinants of Website Loyalty: III. Theoretical and managerial contributions  

Microsoft Academic Search

This paper is the third of the series of studies entitled “Innovativeness and Involvement as Determinants of Website Loyalty”, which was designed to test Foxall's [1995. Cognitive styles of consumer initiators. Technovation 15(5), 269–288] style\\/involvement model in the context of Internet buyer behaviours. This paper aims to demonstrate the theoretical and managerial contributions of Foxall's (1995) style\\/involvement by reviewing the

Hui-Chih Wang; John G. Pallister; Gordon R. Foxall

2006-01-01

50

Consolidation of Tailings.  

National Technical Information Service (NTIS)

The integrity of cover systems placed on tailings impoundments will be affected by the potential for differential settlement of the tailings surface. This report reviews the phenomenon of consolidation for saturated and unsaturated tailings. The effect of...

J. D. Nelson R. E. Wardell S. R. Abt W. P. Staub

1983-01-01

51

Selective interactions of mu-opioid receptors with pertussis toxin-sensitive G proteins: involvement of the third intracellular loop and the c-terminal tail in coupling.  

PubMed

A cDNA encoding the rat mu-opioid receptor was expressed stably in a Rat-1 fibroblast cell line. Expression of this receptor was demonstrated with specific binding of the mu-opioid selective ligand [3H][D-Ala2,N-MePhe4,Gly5-ol]-enkephalin ([3H]DAMGO). In membranes of clone mu11 cells DAMGO produced a robust, concentration-dependent stimulation of basal high affinity GTPase activity. Cholera toxin-catalyzed [32P]ADP-ribosylation in membranes of this clone labelled a 40 kDa Gi family polypeptide(s) that was markedly enhanced by the addition of DAMGO. Antisera against Gi2alpha and Gi3alpha were both able to immunoprecipitate a [32P]-radiolabelled 40 kDa polypeptide(s) from DAMGO and cholera-toxin treated membranes of clone mu11, indicating that the mu-opioid receptor was able to interact effectively with both Gi2 and Gi3 in Rat-1 fibroblasts. A series of peptides derived from the delta-opioid receptor sequence were assessed for their ability to modify agonist-stimulated G protein activation and [3H] agonist binding to the receptor. In membranes from the clone mu11, specific binding of [3H]DAMGO was reduced by peptides corresponding to the NH2-terminal region of the third intracellular loop (i3.1) and the carboxyl-terminal tail (i4) of this receptor. Agonist stimulated GTPase activity and DAMGO dependent cholera toxin-catalyzed [32P]ADP-ribosylation were inhibited by peptides derived from the proximal (i3.1) and the distal portion (i3.3) of the third intracellular loop. Peptide i3.1 also inhibited DAMGO-stimulated [35S]guanosine-5'-O-(3-thio)triphosphate ([35S]GTP-gammaS) binding in the same membranes. In contrast, peptides derived from the second intracellular loop were without any effect. PMID:9434132

Georgoussi, Z; Merkouris, M; Mullaney, I; Megaritis, G; Carr, C; Zioudrou, C; Milligan, G

1997-12-12

52

Molecular players involved in temperature-dependent sex determination and sex differentiation in Teleost fish  

PubMed Central

The molecular mechanisms that underlie sex determination and differentiation are conserved and diversified. In fish species, temperature-dependent sex determination and differentiation seem to be ubiquitous and molecular players involved in these mechanisms may be conserved. Although how the ambient temperature transduces signals to the undifferentiated gonads remains to be elucidated, the genes downstream in the sex differentiation pathway are shared between sex-determining mechanisms. In this paper, we review recent advances on the molecular players that participate in the sex determination and differentiation in fish species, by putting emphasis on temperature-dependent sex determination and differentiation, which include temperature-dependent sex determination and genetic sex determination plus temperature effects. Application of temperature-dependent sex differentiation in farmed fish and the consequences of temperature-induced sex reversal are discussed.

2014-01-01

53

Multiple Cholesterol Recognition/Interaction Amino Acid Consensus (CRAC) Motifs in Cytosolic C Tail of Slo1 Subunit Determine Cholesterol Sensitivity of Ca2+- and Voltage-gated K+ (BK) Channels*  

PubMed Central

Large conductance, Ca2+- and voltage-gated K+ (BK) channel proteins are ubiquitously expressed in cell membranes and control a wide variety of biological processes. Membrane cholesterol regulates the activity of membrane-associated proteins, including BK channels. Cholesterol modulation of BK channels alters action potential firing, colonic ion transport, smooth muscle contractility, endothelial function, and the channel alcohol response. The structural bases underlying cholesterol-BK channel interaction are unknown. Such interaction is determined by strict chemical requirements for the sterol molecule, suggesting cholesterol recognition by a protein surface. Here, we demonstrate that cholesterol action on BK channel-forming Cbv1 proteins is mediated by their cytosolic C tail domain, where we identified seven cholesterol recognition/interaction amino acid consensus motifs (CRAC4 to 10), a distinct feature of BK proteins. Cholesterol sensitivity is provided by the membrane-adjacent CRAC4, where Val-444, Tyr-450, and Lys-453 are required for cholesterol sensing, with hydrogen bonding and hydrophobic interactions participating in cholesterol location and recognition. However, cumulative truncations or Tyr-to-Phe substitutions in CRAC5 to 10 progressively blunt cholesterol sensitivity, documenting involvement of multiple CRACs in cholesterol-BK channel interaction. In conclusion, our study provides for the first time the structural bases of BK channel cholesterol sensitivity; the presence of membrane-adjacent CRAC4 and the long cytosolic C tail domain with several other CRAC motifs, which are not found in other members of the TM6 superfamily of ion channels, very likely explains the unique cholesterol sensitivity of BK channels.

Singh, Aditya K.; McMillan, Jacob; Bukiya, Anna N.; Burton, Brittany; Parrill, Abby L.; Dopico, Alex M.

2012-01-01

54

8 CFR 208.31 - Reasonable fear of persecution or torture determinations involving aliens ordered removed under...  

Code of Federal Regulations, 2010 CFR

...false Reasonable fear of persecution or torture determinations involving aliens ordered...31 Reasonable fear of persecution or torture determinations involving aliens ordered...relevant to the possibility of persecution or torture. The alien's...

2010-01-01

55

8 CFR 208.31 - Reasonable fear of persecution or torture determinations involving aliens ordered removed under...  

Code of Federal Regulations, 2010 CFR

...false Reasonable fear of persecution or torture determinations involving aliens ordered...31 Reasonable fear of persecution or torture determinations involving aliens ordered...relevant to the possibility of persecution or torture. The alien's...

2009-01-01

56

Modelling Cometary Sodium Tails  

NASA Astrophysics Data System (ADS)

Neutral sodium is readily observed in cometary spectra and can be seen to form its own distinct tail at high activity comets. Solar radiation pressure accelerates the sodium atoms antisunward and, as strong sodium absorption lines are present in the solar spectrum, the magnitude of this force is dependent upon the Doppler shift of the incident solar radiation. Therefore the heliocentric velocity of the sodium atom directly determines its acceleration. This can produce unique effects, such as a stagnation region. Sodium is relatively easy to detect and so can potentially be used to trace mechanisms in the coma that are otherwise difficult to observe. The source of neutral sodium in the tail currently remains unknown. We have therefore developed a new, three dimensional Monte-Carlo model of neutral cometary sodium in order to facilitate testing of different source production functions. It includes weightings due to neutral sodium lifetime, variation of cometary sodium emission due to Fraunhofer absorption lines and solar flux variation with heliocentric distance. The Swings and Greenstein effects, which can have particularly dramatic effects in near-Sun comets, are also considered comprehensively. Preliminary results from this model are presented, focusing on a comparison of predictions of the neutral sodium tail of Comet C/2012 S1 (ISON) with initial observations.

Birkett, K. S.; Jones, G. H.; Coates, A. J.

2013-12-01

57

Efficient Algorithms for Computing Sommerfeld Integral Tails  

Microsoft Academic Search

Sommerfeld-integrals (SIs) are ubiquitous in the analysis of problems involving antennas and scatterers embedded in planar multilayered media. It is well known that the oscillating and slowly decaying nature of their integrands makes the numerical evaluation of the SI real-axis tail segment a very time consuming and computationally expensive task. Therefore, SI tails have to be specially treated. In this

Ruzica Golubovic; Athanasios G. Polimeridis; Juan R. Mosig

2012-01-01

58

Identification of Determinants Involved in Initiation of Hepatitis C Virus RNA Synthesis by Using Intergenotypic Replicase Chimeras?  

PubMed Central

The 5? nontranslated region (NTR) and the X tail in the 3? NTR are the least variable parts of the hepatitis C virus (HCV) genome and play an important role in the initiation of RNA synthesis. By using subgenomic replicons of the HCV isolates Con1 (genotype 1) and JFH1 (genotype 2), we characterized the genotype specificities of the replication signals contained in the NTRs. The replacement of the JFH1 5? NTR and X tail with the corresponding Con1 sequence resulted in a significant decrease in replication efficiency. Exchange of the X tail specifically reduced negative-strand synthesis, whereas substitution of the 5? NTR impaired the generation of progeny positive strands. In search for the proteins involved in the recognition of genotype-specific initiation signals, we analyzed recombinant nonstructural protein 5B (NS5B) RNA polymerases of both isolates and found some genotype-specific template preference for the 3? end of positive-strand RNA in vitro. To further address genotype specificity, we constructed a series of intergenotypic replicon chimeras. When combining NS3 to NS5A of Con1 with NS5B of JFH1, we observed more-efficient replication with the genotype 2a X tail, indicating that NS5B recognizes genotype-specific signals in this region. In contrast, a combination of the NS3 helicase with NS5A and NS5B was required to confer genotype specificity to the 5? NTR. These results present the first genetic evidence for an interaction between helicase, NS5A, and NS5B required for the initiation of RNA synthesis and provide a system for the specific analysis of HCV positive- and negative-strand syntheses.

Binder, Marco; Quinkert, Doris; Bochkarova, Olga; Klein, Rahel; Kezmic, Nikolina; Bartenschlager, Ralf; Lohmann, Volker

2007-01-01

59

Determination of the Failure Surface Geometry in Quick Slides Using Balanced Cross Section Techniques - Application to Aznalcóllar Tailings Dam Failure  

Microsoft Academic Search

In a landslide investigation, the location of the failure surface is a difficult task when measures of subsurface displacement are lacking, as it occurs in old landslides or in recent but quick ones. The subsurface geological data and ground surface displacement data may not be enough to formulate a unique interpretation of the failure surface. However, an accurate determination of

José Moya

2004-01-01

60

Determination of the Failure Surface Geometry in Quick Slides Using Balanced Cross Section Techniques - Application to Aznalcóllar Tailings Dam Failure  

Microsoft Academic Search

In a landslide investigation, the location of the failure surface is a difficult task when measures of subsurface displacement are lacking, as it occurs in old landslides or in recent but quick ones. The subsurface geological data and ground surface displacement data may not be enough to formulate a unique interpretation of the failure surface. However, an accurate determination of

José Moya

61

Heads for learning, tails for memory: reward, reinforcement and a role of dopamine in determining behavioral relevance across multiple timescales  

PubMed Central

Dopamine has long been tightly associated with aspects of reinforcement learning and motivation in simple situations where there are a limited number of stimuli to guide behavior and constrained range of outcomes. In naturalistic situations, however, there are many potential cues and foraging strategies that could be adopted, and it is critical that animals determine what might be behaviorally relevant in such complex environments. This requires not only detecting discrepancies with what they have recently experienced, but also identifying similarities with past experiences stored in memory. Here, we review what role dopamine might play in determining how and when to learn about the world, and how to develop choice policies appropriate to the situation faced. We discuss evidence that dopamine is shaped by motivation and memory and in turn shapes reward-based memory formation. In particular, we suggest that hippocampal-striatal-dopamine networks may interact to determine how surprising the world is and to either inhibit or promote actions at time of behavioral uncertainty.

Baudonnat, Mathieu; Huber, Anna; David, Vincent; Walton, Mark E.

2013-01-01

62

Involvement of Androgen Receptor in Sex Determination in an Amphibian Species  

PubMed Central

In mice and humans, the androgen receptor (AR) gene, located on the X chromosome, is not known to be involved in sex determination. In the Japanese frog Rana rugosa the AR is located on the sex chromosomes (X, Y, Z and W). Phylogenetic analysis shows that the AR on the X chromosome (X-AR) of the Korean R. rugosa is basal and segregates into two clusters: one containing W-AR of Japanese R. rugosa, the other containing Y-AR. AR expression is twice as high in ZZ (male) compared to ZW (female) embryos in which the W-AR is barely expressed. Higher AR-expression may be associated with male sex determination in this species. To examine whether the Z-AR is involved in sex determination in R. rugosa, we produced transgenic (Tg) frogs carrying an exogenous Z-AR. Analysis of ZW Tg frogs revealed development of masculinized gonads or ‘ovotestes’. Expression of CYP17 and Dmrt1, genes known to be activated during normal male gonadal development, were up-regulated in the ZW ovotestis. Testosterone, supplied to the rearing water, completed the female-to-male sex-reversal in the AR-Tg ZW frogs. Here we report that Z-AR is involved in male sex-determination in an amphibian species.

Oike, Akira; Matsuo, Yasuki; Min, Mi-Sook; Hasebe, Takashi; Ishizuya-Oka, Atsuko; Kawakami, Koichi; Nakamura, Masahisa

2014-01-01

63

Determination of the Failure Surface Geometry in Quick Slides Using Balanced Cross Section Techniques - Application to Aznalcóllar Tailings Dam Failure  

NASA Astrophysics Data System (ADS)

In a landslide investigation, the location of the failure surface is a difficult task when measures of subsurface displacement are lacking, as it occurs in old landslides or in recent but quick ones. The subsurface geological data and ground surface displacement data may not be enough to formulate a unique interpretation of the failure surface. However, an accurate determination of the failure surface is possible when balanced cross section techniques are applied to preliminary interpretations. The former is proved by means of the example of Aznalcóllar dam failure (Seville, Spain).

Moya, José

64

Magnetohydrodynamics of Mira's cometary tail  

NASA Astrophysics Data System (ADS)

Aims: The asymptotic giant-branch, long-period variable star Mira exhibits a 4 parsec long cometary tail in the far-ultraviolet. We address the issue of the origin of this structure and its emission process by simulating the transition of this star from the interstellar medium to the Local Bubble, which is a tenuous, high-pressure medium. Methods: We use the hydrodynamic and the magnetohydrodynamic modules of the PLUTO astrophysical code to carry out our simulations. We study the system without a cooling function, with a simplified exponential cooling function, and with a simplified nonequilibrium cooling function. Results: We find evidence that magnetohydrodynamics constrain the shape of the cometary tail and explain features of its far-ultraviolet emission. We suggest an emission process that involves C0 excitation through inelastic electron collisions and a two-photon continuum to explain the luminosity of Mira's tail.

Gómez, E. A.

2013-10-01

65

Uranium Mill Tailings Management  

SciTech Connect

This book presents the papers given at the Fifth Symposium on Uranium Mill Tailings Management. Advances made with regard to uranium mill tailings management, environmental effects, regulations, and reclamation are reviewed. Topics considered include tailings management and design (e.g., the Uranium Mill Tailings Remedial Action Project, environmental standards for uranium mill tailings disposal), surface stabilization (e.g., the long-term stability of tailings, long-term rock durability), radiological aspects (e.g. the radioactive composition of airborne particulates), contaminant migration (e.g., chemical transport beneath a uranium mill tailings pile, the interaction of acidic leachate with soils), radon control and covers (e.g., radon emanation characteristics, designing surface covers for inactive uranium mill tailings), and seepage and liners (e.g., hydrologic observations, liner requirements).

Nelson, J.D.

1982-01-01

66

Child with a Tail  

PubMed Central

Spina Bifida occulta usually presents with some cutaneous stigmata e.g. hair patch, sinus, lipoma, hyperpigmented skin and very rarely a congenital tail. A congenital tail may and may not be associated with spina bifida occulta and tethered cord. A four month old male child presented with congenital tail which was associated with spinal dysraphism and caused tethering of the cord itself. The tail and tethering lesion were excised successfully.

Sandhu, Asif Iqbal; Khan, Feeroz Alam; Ehmed, Ejaz; Dar, Sajid Hameed

2013-01-01

67

Length of Magnetospheric Tail  

Microsoft Academic Search

It is shown that hydromagnetic waves, through the action of radiation pressure, can prevent the tail of the magnetosphere from closing near the earth. It is argued that the tail of the magnetosphere may be 20 to 50 AU long. The tail can close at such heliocentric distances in the charge-exchange boundary shell where the solar wind is terminated and

A. J. Dessler

1964-01-01

68

Determination of Sites Involved, HIV Co-Infection & Utility of Diagnostic Modalities in EPTB  

PubMed Central

Background: Tuberculosis remains a major global public health problem and an on-going epidemic. Though the chief objectives of the Revised National Tuberculosis Control Programme (RNTCP) in detecting and curing the infectious pulmonary cases is well taken, there has been a steady rise in the number of Extra Pulmonary Tuberculosis (EPTB) cases as documented in several studies. EPTB which usually constitutes around 15%-20% of the total TB cases is now being increasingly reported due to a combination of better diagnostic facilities, and the HIV pandemic. Though several studies have shown increasing prevalence of EPTB, only few studies are available, especially in the Indian scenario, that study the pattern and risk factors. Hence, this retrospective observational study was undertaken to determine the sites of the involvement, HIV co-infection and usefulness of various diagnostic modalities in EPTB affecting patients attending a medical college DOTS clinic. Material and Methods: One hundred ten EPTB patients referred to the DOTS clinics of the TB & Chest department from the period Dec 2010– Mar 2012 were included in the study. The diagnosis of EPTB was established by combined clinical, microbiological, histopathological &/or imaging modalities. Their medical records were assessed to determine the age distribution, gender and anatomical sites of involvement. The presence of co-morbid conditions like smoking history, alcoholism, diabetic and HIV status were noted. BCG status and Mantoux test readings were recorded. The different diagnostic tests used in confirming EPTB at different sites were recorded. Chest x-ray was analysed for all patients to assess coexisting pulmonary involvement. All patients were followed to assess the outcome of treatment. Results: The mean age of patients was 34.4. The male to female ratio was 58:52 showing a slight male predominance. The most common site of involvement was lymph node followed by pleural effusion and abdominal TB. The prevalence of lymph node TB was noted to be higher in female patients as compared to other sites of EPTB. Mantoux test was positive in 57 (51.8%) patients. HIV co-infection was noted in only 3 (2.7%) patients. Concomitant pulmonary involvement was seen in 19 (17.3%) patients. Conclusions: Lymph node was the most common site involvement showing a significant female preponderance followed by pleural effusion and abdominal TB. The rates of HIV co-infection and diabetes mellitus were 2.7% and 20% respectively. The most useful diagnostic modality was tissue sampling followed by imaging. Mantoux test is not unequivocal for the diagnosis of EPTB.

Shanmuganathan, Aruna; R, Srinivasan; G, Thilagavathy; D, Satishkumar; C, Sidduraj; James, Bonny

2013-01-01

69

Determination of Sites Involved, HIV Co-Infection & Utility of Diagnostic Modalities in EPTB.  

PubMed

Background: Tuberculosis remains a major global public health problem and an on-going epidemic. Though the chief objectives of the Revised National Tuberculosis Control Programme (RNTCP) in detecting and curing the infectious pulmonary cases is well taken, there has been a steady rise in the number of Extra Pulmonary Tuberculosis (EPTB) cases as documented in several studies. EPTB which usually constitutes around 15%-20% of the total TB cases is now being increasingly reported due to a combination of better diagnostic facilities, and the HIV pandemic. Though several studies have shown increasing prevalence of EPTB, only few studies are available, especially in the Indian scenario, that study the pattern and risk factors. Hence, this retrospective observational study was undertaken to determine the sites of the involvement, HIV co-infection and usefulness of various diagnostic modalities in EPTB affecting patients attending a medical college DOTS clinic. Material and Methods: One hundred ten EPTB patients referred to the DOTS clinics of the TB & Chest department from the period Dec 2010- Mar 2012 were included in the study. The diagnosis of EPTB was established by combined clinical, microbiological, histopathological &/or imaging modalities. Their medical records were assessed to determine the age distribution, gender and anatomical sites of involvement. The presence of co-morbid conditions like smoking history, alcoholism, diabetic and HIV status were noted. BCG status and Mantoux test readings were recorded. The different diagnostic tests used in confirming EPTB at different sites were recorded. Chest x-ray was analysed for all patients to assess coexisting pulmonary involvement. All patients were followed to assess the outcome of treatment. Results: The mean age of patients was 34.4. The male to female ratio was 58:52 showing a slight male predominance. The most common site of involvement was lymph node followed by pleural effusion and abdominal TB. The prevalence of lymph node TB was noted to be higher in female patients as compared to other sites of EPTB. Mantoux test was positive in 57 (51.8%) patients. HIV co-infection was noted in only 3 (2.7%) patients. Concomitant pulmonary involvement was seen in 19 (17.3%) patients. Conclusions: Lymph node was the most common site involvement showing a significant female preponderance followed by pleural effusion and abdominal TB. The rates of HIV co-infection and diabetes mellitus were 2.7% and 20% respectively. The most useful diagnostic modality was tissue sampling followed by imaging. Mantoux test is not unequivocal for the diagnosis of EPTB. PMID:24086863

Shanmuganathan, Aruna; R, Srinivasan; G, Thilagavathy; D, Satishkumar; C, Sidduraj; James, Bonny

2013-08-01

70

Detailing the human tail.  

PubMed

There have been 23 true vestigial tails reported in the literature since 1884. A new case is described, and its magnetic resonance imaging and pathological features are presented. A review of the literature and analysis of the pathological characteristics reveal that the vestigial human tail may be associated with other abnormalities. Vestigial tails contain adipose and connective tissue, blood vessels, and nerves and are covered by skin. Bone, cartilage, notochord, and spinal cord elements are lacking. Tails are easily removed surgically without residual effects. Since 29% (7 of 24) of the reported tails have been associated with other malformations, careful clinical evaluation of these patients is recommended. PMID:3284435

Dubrow, T J; Wackym, P A; Lesavoy, M A

1988-04-01

71

Zebrafish sex determination and differentiation: Involvement of FTZ-F1 genes  

PubMed Central

Sex determination is the process deciding the sex of a developing embryo. This is usually determined genetically; however it is a delicate process, which in many cases can be influenced by environmental factors. The mechanisms controlling zebrafish sex determination and differentiation are not known. To date no sex linked genes have been identified in zebrafish and no sex chromosomes have been identified. However, a number of genes, as presented here, have been linked to the process of sex determination or differentiation in zebrafish. The zebrafish FTZ-F1 genes are of central interest as they are involved in regulating interrenal development and thereby steroid biosynthesis, as well as that they show expression patterns congruent with reproductive tissue differentiation and function. Zebrafish can be sex reversed by exposure to estrogens, suggesting that the estrogen levels are crucial during sex differentiation. The Cyp19 gene product aromatase converts testosterone into 17 beta-estradiol, and when inhibited leads to male to female sex reversal. FTZ-F1 genes are strongly linked to steroid biosynthesis and the regulatory region of Cyp19 contains binding sites for FTZ-F1 genes, further linking FTZ-F1 to this process. The role of FTZ-F1 and other candidates for zebrafish sex determination and differentiation is in focus of this review.

von Hofsten, Jonas; Olsson, Per-Erik

2005-01-01

72

Innovativeness and Involvement as Determinants of Website Loyalty: I. A test of the style\\/involvement model in the context of Internet buying  

Microsoft Academic Search

This paper is the first of the series of studies entitled “Innovativeness and Involvement as Determinants of Website Loyalty”, which was designed to test Foxall's [1995. Cognitive styles of consumer initiators. Technovation 15(5), 269–288] style\\/involvement model in the context of Internet buyer behaviours. The study was built on 1044 Taiwan Internet buyers randomly selected from a well-known brand's Website in

Hui-Chih Wang; John G. Pallister; Gordon R. Foxall

2006-01-01

73

Research in primary care: extent of involvement and perceived determinants among practitioners from one English region.  

PubMed Central

The lack of research evidence relevant to and generated by general practitioners (GPs) has been a concern in the context of a putative primary care-led National Health Service (NHS). However, very little has been published on the current extent or determinants of research activity among United Kingdom primary care doctors. We surveyed all (n = 2770) service GPs in the West Midlands Region in order to quantify their research involvement and to explore determinants of this. The response rate was 49% (n = 1351). A total of 84% of responders reported participating in research or audit, with 16% having initiated their own research; 9% of GPs had been published in a peer-reviewed journal; 6% had generated research funding; and 3% had held a research training fellowship. The characteristics positively associated with initiating research included an involvement in teaching, having research-active partners, the availability of protected time, and working in a larger practice. The most commonly perceived barriers to undertaking research were lack of time (92%), lack of staff to collect data (73%), and a lack of funding (71%). In all, 41% of responders reported no interest in research. Overall, the extent of research activity among responding GPs appears to be greater than is often assumed. Recent NHS research and development proposals to strengthen and develop research in primary care are, therefore, relevant in highlighting changes to address these issues.

Jowett, S M; Macleod, J; Wilson, S; Hobbs, F D

2000-01-01

74

Determination of catalase activity using chromogenic probe involving iso-nicotinicacidhydrazide and pyrocatechol.  

PubMed

A biocatalatic pathway involving chromogenic probe has been proposed for the determination of catalase activity by means of iso-nicotinicacidhydrazide (INH) and pyrocatechol (PC). The assay is based on the enzymatic consumption of hydrogen peroxide using INH-PC system. The response of the catalase activity was ascertained by the rate of the reaction involving 14.10mM H(2)O(2). On addition of H(2)O(2), INH-PC indicator system formed a chromogenic product with absorbance maxima at 490 nm. Hence the activity of catalase was directly measured by the chromogenic response in the formation of the coupled product. The catalase assay was elaborated by the kinetic response of the INH-PC system. The linearity of the catalase activity and H(2)O(2) was in the range 0.2-7.0 units and 1.76-7.0mM, respectively in 3 ml solution. The catalytic efficiency and catalytic power were calculated. The Michaelis-Menten constant of INH, PC and H(2)O(2) were found to be 0.344, 0.176 and 8.82 mM, respectively. The indicator reaction was applied in the determination of catalase activity in mycelia mats and culture media. PMID:21839122

Shivakumar, Anantharaman; Nagaraja, Padmarajaiah; Chamaraja, Nelligere Arkeshwaraiah; Krishna, Honnur; Avinash, Krishnegowda

2011-10-10

75

Genetic and epigenetic determinants mediate proneness of oncogene breakpoint sites for involvement in TCR translocations.  

PubMed

T-cell receptor (TCR) translocations are a genetic hallmark of T-cell acute lymphoblastic leukemia and lead to juxtaposition of oncogene and TCR loci. Oncogene loci become involved in translocations because they are accessible to the V(D)J recombination machinery. Such accessibility is predicted at cryptic recombination signal sequence (cRSS) sites ('Type 1') as well as other sites that are subject to DNA double-strand breaks (DSBs) ('Type 2') during early stages of thymocyte development. As chromatin accessibility markers have not been analyzed in the context of TCR-associated translocations, various genetic and epigenetic determinants of LMO2, TAL1 and TLX1 translocation breakpoint (BP) sites and BP cluster regions (BCRs) were examined in human thymocytes to establish DSB proneness and heterogeneity of BP site involvement in TCR translocations. Our data show that DSBs in BCRs are primarily induced in the presence of a genetic element of sequence vulnerability (cRSSs, transposable elements), whereas breaks at single BP sites lacking such elements are more likely induced by chance or perhaps because of patient-specific genetic vulnerability. Vulnerability to obtain DSBs is increased by features that determine chromatin organization, such as methylation status and nucleosome occupancy, although at different levels at different BP sites. PMID:24304972

Larmonie, N S D; van der Spek, A; Bogers, A J J C; van Dongen, J J M; Langerak, A W

2014-03-01

76

Novel non-Mendelian determinant involved in the control of translation accuracy in Saccharomyces cerevisiae.  

PubMed Central

Two cytoplasmically inherited determinants related by their manifestation to the control of translation accuracy were previously described in yeast. Cells carrying one of them, [PSI(+)], display a nonsense suppressor phenotype and contain a prion form of the Sup35 protein. Another element, [PIN(+)], determines the probability of de novo generation of [PSI(+)] and results from a prion form of several proteins, which can be functionally unrelated to Sup35p. Here we describe a novel nonchromosomal determinant related to the SUP35 gene. This determinant, designated [ISP(+)], was identified as an antisuppressor of certain sup35 mutations. We observed its loss upon growth on guanidine hydrochloride and subsequent spontaneous reappearance with high frequency. The reversible curability of [ISP(+)] resembles the behavior of yeast prions. However, in contrast to known prions, [ISP(+)] does not depend on the chaperone protein Hsp104. Though manifestation of both [ISP(+)] and [PSI(+)] is related to the SUP35 gene, the maintenance of [ISP(+)] does not depend on the prionogenic N-terminal domain of Sup35p and Sup35p is not aggregated in [ISP(+)] cells, thus ruling out the possibility that [ISP(+)] is a specific form of [PSI(+)]. We hypothesize that [ISP(+)] is a novel prion involved in the control of translation accuracy in yeast.

Volkov, Kirill V; Aksenova, Anna Yu; Soom, Malle J; Osipov, Kirill V; Svitin, Anton V; Kurischko, Cornelia; Shkundina, Irina S; Ter-Avanesyan, Michael D; Inge-Vechtomov, Sergey G; Mironova, Ludmila N

2002-01-01

77

Characterization of the Distal Tail Fiber Locus and Determination of the Receptor for Phage AR1, Which Specifically Infects Escherichia coli O157:H7  

PubMed Central

Phage AR1 is similar to phage T4 in several essential genes but differs in host range. AR1 infects various isolates of Escherichia coli O157:H7 but does not infect K-12 strains that are commonly infected by T4. We report here the determinants that confer this infection specificity. In T-even phages, gp37 and gp38 are components of the tail fiber that are critical for phage-host interaction. The counterparts in AR1 may be similarly important and, therefore, were characterized. The AR1 gp37 has a sequence that differs totally from those of T2 and T4, except for a short stretch at the N terminus. The gp38 sequence, however, has some conservation between AR1 and T2 but not between AR1 and T4. The sequences that are most closely related to the AR1 gp37 and gp38 are those of phage Ac3 in the T2 family. To identify the AR1-specific receptor, E. coli O157:H7 was mutated by Tn10 insertion and selected for an AR1-resistant phenotype. A mutant so obtained has an insertion occurring at ompC that encodes an outer membrane porin. To confirm the role of OmpC in the AR1 infection, homologous replacement was used to create an ompC disruption mutant (RM). When RM was complemented with OmpC originated from an O157:H7 strain, but not from K-12, its AR1 susceptibility was fully restored. Our results suggest that the host specificity of AR1 is mediated at least in part through the OmpC molecule.

Yu, Sung-Liang; Ko, Kai-Liang; Chen, Chang-Shi; Chang, Yu-Chung; Syu, Wan-Jr

2000-01-01

78

Genetic Evidence That the Ovo Locus Is Involved in Drosophila Germ Line Sex Determination  

PubMed Central

Zygotically contributed ovo gene product is required for the survival of female germ cells in Drosophila melanogaster. Trans-allelic combinations of weak and dominant ovo mutations (ovo(D)) result in viable germ cells that appear to be partially transformed from female to male sexual identity. The ovo(D2) mutation is partially suppressed by many Sex-lethal alleles that affect the soma, while those that affect only the germ line fail to interact with ovo(D2). One of two loss-of-function ovo alleles is suppressed by a loss-of-function Sex-lethal allele. Because ovo mutations are germ line dependent, it is likely that ovo is suppressed by way of communication between the somatic and germ lines. A loss-of-function allele of ovo is epistatic to germ line dependent mutations in Sex-lethal. The germ line dependent sex determination mutation, sans fille, and ovo(D) mutations show a dominant synergistic interaction resulting in partial transformation of germ line sexual identity. The ovo locus appears to be involved in germ line sex determination and is linked in some manner to sex determination in the soma.

Oliver, B.; Pauli, D.; Mahowald, A. P.

1990-01-01

79

Derivation and implementation of an annual limit on intake and a derived air concentration value for uranium mill tailings.  

PubMed

Monitoring workers and work areas at the Department of Energy Uranium Mill Tailings Remedial Action Project sites is complex because all radionuclides in the 238U and 235U decay chains may be present in an airborne uranium mill tailings matrix. Previous monitoring practices involved isotopic analysis of the air filter to determine the activity of each radionuclide of concern and comparing the results to the specified derived air concentration. The annual limit on intake and derived air concentration values have been derived here for the uranium mill tailings matrix to simplify the procedure for evaluation of air monitoring results and assessment of the need for individual monitoring. Implementation of the derived air concentration for uranium mill tailings involves analyzing air samples for long-lived gross alpha activity and comparing the activity concentration to the derived air concentration. Health physics decisions regarding assessment of airborne concentrations is more cost-effective because isotopic analysis of air samples is not necessary. PMID:7759261

Reif, R H; Andrews, D W

1995-06-01

80

Effect of horizontal-tail span and vertical location on the aerodynamic characteristics of an unswept tail assembly in sideslip  

NASA Technical Reports Server (NTRS)

An investigation has been conducted in the Langley stability tunnel on a vertical-tail model with a stub fuselage in combination with various horizontal tails to determine the effect of horizontal-tail span and vertical location of the horizontal tail relative to the vertical tail on the aerodynamic characteristics of an unswept tail assembly in sideslip. The results of the investigation indicated that the induced loading carried by the horizontal tail produced a rolling moment about the point of attachment to the vertical tail which was strongly influenced by horizontal-tail span and vertical locations. The greatest effect of horizontal-tail span on the rolling-moment derivative of the complete tail assembly was obtained for horizontal-tail locations near the top of the vertical tail. Span loadings which were reduced to the static-stability derivatives were calculated for each configuration tested by applying the well-known finite-step method used for wings to the intersecting surfaces of the vertical and horizontal tails. The finite-step method provides a simple and effective means of investigating the span loadings of intersecting surfaces.

Riley, Donald R

1954-01-01

81

A review on dural tail sign  

PubMed Central

“Dural tail sign” (DTS) which is a thickening of the dura adjacent to an intracranial pathology on contrast-enhanced T1 MR Images, was first thought to be pathognomonic of meningioma, however, many subsequent studies demonstrated this sign adjacent to various intra- and extra-cranial pathologies and in spinal lesions. In this paper we outline the history, accompanying pathologies and the differentiation and probable pathophysiology of DTS. We also discuss whether we can predict tumoral involvement of the dural tail before surgery and whether the dural tail adjacent to a tumor should be resected.

Sotoudeh, Houman; Yazdi, Hadi Rokni

2010-01-01

82

A review on dural tail sign.  

PubMed

"Dural tail sign" (DTS) which is a thickening of the dura adjacent to an intracranial pathology on contrast-enhanced T1 MR Images, was first thought to be pathognomonic of meningioma, however, many subsequent studies demonstrated this sign adjacent to various intra- and extra-cranial pathologies and in spinal lesions. In this paper we outline the history, accompanying pathologies and the differentiation and probable pathophysiology of DTS. We also discuss whether we can predict tumoral involvement of the dural tail before surgery and whether the dural tail adjacent to a tumor should be resected. PMID:21161034

Sotoudeh, Houman; Yazdi, Hadi Rokni

2010-05-28

83

Caste determination in a polyembryonic wasp involves inheritance of germ cells  

PubMed Central

Social insects are characterized by the development of castes in which some colony members reproduce whereas others function as altruistic helpers. The conditional switch controlling caste formation usually involves environmental stimuli that act on processes that regulate development of individuals. Unlike other social species, embryos of polyembryonic wasps develop clonally to produce large numbers of genetically identical offspring and two morphologically distinct castes. All embryos in a clone exist in an identical environment, the host, yet develop into either reproductive larvae that mature into adult wasps or soldier larvae whose function is defense. Here, we report that caste determination in Copidosoma floridanum involves inheritance of germ cells. Expression of a C. floridanum homolog (Cf-vas) of the germ cell marker Vasa indicated that the B4 blastomere in four cell-stage embryos is specified as a primordial germ cell. Vas expression later in development further indicated that embryos developing into reproductive larvae possess primordial germ cells whereas embryos developing into soldier larvae do not. Ablation of the B4 blastomere resulted in most broods containing only soldiers whereas ablation of other blastomeres produced broods containing both castes. These results indicate that soldier larvae are obligately sterile and reveal a previously unknown role for germ cells in caste formation.

Donnell, David M.; Corley, Laura S.; Chen, Gang; Strand, Michael R.

2004-01-01

84

Ecological aspects of microorganisms inhabiting uranium mill tailings  

Microsoft Academic Search

Numbers and types of microorganisms in uranium mill tailings were determined using culturing techniques.Arthrobacter were found to be the predominant microorganism inhabiting the sandy tailings, whereasBacillus and fungi predominated in the slime tailings. Sulfate-reducing bacteria, capable of leaching radium, were isolated in low numbers from tailings samples but were isolated in significantly high numbers from topsoil in contact with the

Christine L. Miller; Edward R. Landa; David M. Updegraff

1987-01-01

85

Tissue-Specific Expression of Head-to-Tail Cyclized Miniproteins in Violaceae and Structure Determination of the Root Cyclotide Viola hederacea root cyclotide1  

Microsoft Academic Search

The plant cyclotides are a family of 28 to 37 amino acid miniproteins characterized by their head-to-tail cyclized peptide backbone and six absolutely conserved Cys residues arranged in a cystine knot motif: two disulfide bonds and the connect- ing backbone segments form a loop that is penetrated by the third disulfide bond. This knotted disulfide arrangement, together with the cyclic

Manuela Trabi; David J. Craik

2004-01-01

86

Tails of Bacterial Motility  

NASA Astrophysics Data System (ADS)

The cytoplasm of living cells provides a complex fluid environment in which intracellular bacteria live and move. By analyzing the easily visible curved actin ``comet-tail'' of polymerization-based-motility bacteria such as Listeria monocytogenes, we can learn about sub-micron structure and dynamics of the tail and of the bacterial surface enzyme that catalyzes tail formation. By characterizing the motility, we can transform such motile systems into probes of the cytoplasmic environment.

Rutenberg, Andrew; Grant, Martin

2001-03-01

87

Chemical determinants involved in anandamide-induced inhibition of T-type calcium channels.  

PubMed

Anandamide, originally described as an endocannabinoid, is the main representative molecule of a new class of signaling lipids including endocannabinoids and N-acyl-related molecules, eicosanoids, and fatty acids. Bioactive lipids regulate neuronal excitability by acting on G-protein-coupled receptors (such as CB1) but also directly modulate various ionic conductances including voltage-activated T-type calcium channels (T-channels). However, little is known about the properties and the specificity of this new class of molecules on their various targets. In this study, we have investigated the chemical determinants involved in anandamide-induced inhibition of the three cloned T-channels: Ca(V)3.1, Ca(V)3.2, and Ca(V)3.3. We show that both the hydroxyl group and the alkyl chain of anandamide are key determinants of its effects on T-currents. As follows, T-currents are also inhibited by fatty acids. Inhibition of the three Ca(V)3 currents by anandamide and arachidonic acid does not involve enzymatic metabolism and occurs in cell-free inside-out patches. Inhibition of T-currents by fatty acids and N-acyl ethanolamides depends on the degree of unsaturation but not on the alkyl chain length and consequently is not restricted to eicosanoids. Inhibition increases for polyunsaturated fatty acids comprising 18-22 carbons when cis-double bonds are close to the carboxyl group. Therefore the major natural (food-supplied) and mammalian endogenous fatty acids including gamma-linolenic acid, mead acid, and arachidonic acid as well as the fully polyunsaturated omega3-fatty acids that are enriched in fish oil eicosapentaenoic and docosahexaenoic acids are potent inhibitors of T-currents, which possibly contribute to their physiological functions. PMID:17121818

Chemin, Jean; Nargeot, Joel; Lory, Philippe

2007-01-26

88

Research on the characterization and conditioning of uranium mill tailings. Volume 1. I. Characterization and leaching behavior of uranium mill tailings  

Microsoft Academic Search

The goal of these studies on tailings characterization was to determine the mineralogical and elemental composition of various tailings materials, as well as to evaluate their contaminant leachability and radon emanation properties. Extreme variability within and between tailings piles was noted for major, minor, and trace elements and radionuclides. The most commonly enriched contaminants found in 12 tailings site composites

D. R. Dreesen; M. E. Bunker; E. J. Cokal; M. M. Denton; J. W. Starner; E. F. Thode; L. E. Wangen; J. M. Williams

1983-01-01

89

Horizontal tail loads in maneuvering flight  

NASA Technical Reports Server (NTRS)

A method is given for determining the horizontal tail loads in maneuvering flight. The method is based upon the assignment of a load-factor variation with time and the determination of a minimum time to reach peak load factor. The tail load is separated into various components. Examination of these components indicated that one of the components was so small that it could be neglected for most conventional airplanes; therefore, the number of aerodynamic parameters needed in this computation of tail loads was reduced to a minimum. In order to illustrate the method, as well as to show the effect of the main variables, a number of examples are given. Some discussion is given regarding the determination of maximum tail loads, maximum pitching accelerations, and maximum pitching velocities obtainable.

Pearson, Henry A; Mcgowan, William A; Donegan, James J

1951-01-01

90

Exploring determinants of job involvement: an empirical test among senior executives  

Microsoft Academic Search

Purpose – This study proposes and tests a model that attempts to explain the role of situational and personal-related factors relating to why top executives become involved in their jobs. Design\\/methodology\\/approach – Building on job involvement, literature, the present study involved senior managers employed in public sector organizations in Israel. Data were collected through structured surveys. A total of 98

Abraham Carmeli

2005-01-01

91

8 CFR 1208.31 - Reasonable fear of persecution or torture determinations involving aliens ordered removed under...  

Code of Federal Regulations, 2010 CFR

8 Aliens and Nationality 1 2010-01-01 2010-01-01...fear of persecution or torture determinations involving aliens ordered removed under section 238(b) of the Act and aliens whose removal is reinstated under section...

2010-01-01

92

Mineralogic variations in fluvial sediments contaminated by mine tailings as determined from AVIRIS data, Coeur D'Alene River Valley, Idaho  

NASA Technical Reports Server (NTRS)

The success of imaging spectrometry in mineralogic mapping of natural terrains indicates that the technology can also be used to assess the environmental impact of human activities in certain instances. Specifically, this paper describes an investigation into the use of data from the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) for mapping the spread of, and assessing changes in, the mineralogic character of tailings from a major silver and base metal mining district. The area under investigation is the Coeur d'Alene River Valley in northern Idaho. Mining has been going on in and around the towns of Kellogg and Wallace, Idaho since the 1880's. In the Kellogg-Smelterville Flats area, west of Kellogg, mine tailings were piled alongside the South Fork of the Coeur d'Alene River. Until the construction of tailings ponds in 1968 much of these waste materials were washed directly into the South Fork. The Kellogg-Smelterville area was declared an Environmental Protection Agency (EPA) Superfund site in 1983 and remediation efforts are currently underway. Recent studies have demonstrated that sediments in the Coeur d'Alene River and in the northern part of Lake Coeur d'Alene, into which the river flows, are highly enriched in Ag, Cu, Pb, Zn, Cd, Hg, As, and Sb. These trace metals have become aggregated in iron oxide and oxyhydroxide minerals and/or mineraloids. Reflectance spectra of iron-rich tailing materials are shown. Also shown are spectra of hematite and goethite. The broad bandwidth and long band center (near 1 micron) of the Fe(3+) crystal-field band of the iron-rich sediment samples combined with the lack of features on the Fe(3+) -O(2-) charge transfer absorption edge indicates that the ferric oxide and/or oxyhydroxide in these sediments is poorly crystalline to amorphous in character. Similar features are seen in poorly crystalline basaltic weathering products (e.g., palagonites). The problem of mapping and analyzing the downriver occurrences of iron rich tailings in the Coeur d'Alene (CDA) River Valley using remotely sensed data is complicated by the full vegetation cover present in the area. Because exposures of rock and soil were sparse, the data processing techniques used in this study were sensitive to detecting materials at subpixel scales. The methods used included spectral mixture analysis and a constrained energy minimization technique.

Farrand, W. H.; Harsanyi, Joseph C.

1995-01-01

93

Long-Term Ecological Behaviour of Abandoned Uranium Mill Tailings. 1. Synoptic Survey and Identification of Invading Biota.  

National Technical Information Service (NTIS)

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 ...

M. Kalin

1983-01-01

94

Active and accurate trans-translation requires distinct determinants in the C-terminal tail of SmpB protein and the mRNA-like domain of transfer messenger RNA (tmRNA).  

PubMed

Unproductive ribosome stalling in eubacteria is resolved by the actions of SmpB protein and transfer messenger (tm) RNA. We examined the functional significance of conserved regions of SmpB and tmRNA to the trans-translation process. Our investigations reveal that the N-terminal 20 residues of SmpB, which are located near the ribosomal decoding center, are dispensable for all known SmpB activities. In contrast, a set of conserved residues that reside at the junction between the tmRNA-binding core and the C-terminal tail of SmpB play an important role in tmRNA accommodation. Our data suggest that the highly conserved glycine 132 acts as a flexible hinge that enables movement of the C-terminal tail, thus permitting proper positioning and establishment of the tmRNA open reading frame (ORF) as the surrogate template. To gain further insights into the function of the SmpB C-terminal tail, we examined the tagging activity of hybrid variants of tmRNA and the SmpB protein, in which the tmRNA ORF or the SmpB C-terminal tail was substituted with the equivalent but highly divergent sequences from Francisella tularensis. We observed that the hybrid tmRNA was active but resulted in less accurate selection of the resume codon. Cognate hybrid SmpB was necessary to restore activity. Furthermore, accurate tagging was observed when the identity of the resume codon was reverted from GGC to GCA. Taken together, these data suggest that the engagement of the tmRNA ORF and the selection of the correct translation resumption point are distinct activities that are influenced by independent tmRNA and SmpB determinants. PMID:23986442

Camenares, Devin; Dulebohn, Daniel P; Svetlanov, Anton; Karzai, A Wali

2013-10-18

95

Human tails and pseudotails.  

PubMed

A case of a tail in a 2-week-old infant is reported, and findings from a review of 33 previously reported cases of true tails and pseudotails are summarized. The true, or persistent, vestigial tail of humans arises from the most distal remnant of the embryonic tail. It contains adipose and connective tissue, central bundles of striated muscle, blood vessels, and nerves and is covered by skin. Bone, cartilage, notochord, and spinal cord are lacking. The true tail arises by retention of structures found normally in fetal development. It may be as long as 13 cm, can move and contract, and occurs twice as often in males as in females. A true tail is easily removed surgically, without residual effects. It is rarely familial. Pseudotails are varied lesions having in common a lumbosacral protrusion and a superficial resemblance to persistent vestigial tails. The most frequent cause of a pseudotail in a series of ten cases obtained from the literature was an anomalous prolongation of the coccygeal vertebrae. Additional lesions included two lipomas, and one each of teratoma, chondromegaly , glioma, and a thin, elongated parasitic fetus. PMID:6373560

Dao, A H; Netsky, M G

1984-05-01

96

The kangaroo's tail propels and powers pentapedal locomotion.  

PubMed

When moving slowly, kangaroos plant their tail on the ground in sequence with their front and hind legs. To determine the tail's role in this 'pentapedal' gait, we measured the forces the tail exerts on the ground and calculated the mechanical power it generates. We found that the tail is responsible for as much propulsive force as the front and hind legs combined. It also generates almost exclusively positive mechanical power, performing as much mass-specific mechanical work as does a human leg during walking at the same speed. Kangaroos use their muscular tail to support, propel and power their pentapedal gait just like a leg. PMID:24990111

O'Connor, Shawn M; Dawson, Terence J; Kram, Rodger; Donelan, J Maxwell

2014-07-01

97

Estimating tail probabilities  

SciTech Connect

This paper investigates procedures for univariate nonparametric estimation of tail probabilities. Extrapolated values for tail probabilities beyond the data are also obtained based on the shape of the density in the tail. Several estimators which use exponential weighting are described. These are compared in a Monte Carlo study to nonweighted estimators, to the empirical cdf, to an integrated kernel, to a Fourier series estimate, to a penalized likelihood estimate and a maximum likelihood estimate. Selected weighted estimators are shown to compare favorably to many of these standard estimators for the sampling distributions investigated.

Carr, D.B.; Tolley, H.D.

1982-12-01

98

Asbestos tailings as aggregates for asphalt mixture  

Microsoft Academic Search

To use many asbestos tailings collected in Ya-Lu highway, and to explore the feasibility of using asbestos tailings as aggregates\\u000a in common asphalt mixtures, and properties of some asphalt mixtures were evaluated as well. X-ray diffraction (XRD), X-ray\\u000a fluorescent (XRF), and atomic absorption spectrophotometry (AAS) were employed to determine the solid waste content of copper,\\u000a zinc, lead, and cadmium. Volume

Xiaoming Liu; Linrong Xu

2011-01-01

99

Determinants of muscle metaboreflex and involvement of baroreflex in boys and young men.  

PubMed

This study aimed to assess the arterial pressure (AP) determinants during the muscle metaboreflex in boys and men and to investigate the contribution of baroreflex and sympathovagal function to the metaboreflex-induced responses. Fourteen pre-adolescent boys and 13 men performed a protocol involving: baseline, isometric handgrip exercise, circulatory occlusion, and recovery. The same protocol was repeated without occlusion. During baseline, boys had lower beat-to-beat AP, higher heart rate (HR), and lower low/high frequency HR variability. During exercise, a parasympathetic withdrawal was evident in both groups. In adults, HR was the key contributor to the pressure response, with no changes in stroke volume, whereas in boys, the lower HR increase was counterbalanced by an increase in stroke volume, resulting in similar relative increases in AP in both groups. In recovery, boys exhibited a faster rate of HR-decay, rapid vagal reactivation, and greater decrease in TPR than men. An overshoot in baroreceptor sensitivity was observed in men. The isolated metaboreflex resulted in a similar AP elevation in both age groups (by ~15 mmHg), and attenuated spontaneous baroreceptor sensitivity. However, during the metaboreflex, pre-adolescent males exhibited a lower increase in peripheral resistance and a greater bradycardic response than adults, and a fast restoration of vagal activity to non-occlusion levels. During metaboreflex, boys were capable of eliciting a pressure response similar to the one elicited by men; however, the interplay of the mechanisms underlying the rise in AP differed between the two groups with the vagal contribution being greater in the younger participants. PMID:22983569

Dipla, Konstantina; Papadopoulos, Stavros; Zafeiridis, Andreas; Kyparos, Antonios; Nikolaidis, Michalis G; Vrabas, Ioannis S

2013-04-01

100

Determinants of Pseudomonas putida WCS358 involved in inducing systemic resistance in plants.  

PubMed

SUMMARY Pseudomonas putida WCS358 is a plant growth-promoting rhizobacterium originally isolated from the rhizosphere of potato. It can suppress soil-borne plant diseases by siderophore-mediated competition for iron, but it has also been reported to result in induced systemic resistance (ISR) in Arabidopsis thaliana. Bacterial determinants of this strain involved in inducing systemic resistance in Arabidopsis were investigated using a Tn5 transposon mutant defective in biosynthesis of the fluorescent siderophore pseudobactin, a non-motile Tn5 mutant lacking flagella, and a spontaneous phage-resistant mutant lacking the O-antigenic side chain of the lipopolysaccharides (LPS). When using Pseudomonas syringae pv. tomato as the challenging pathogen, purified pseudobactin, flagella and LPS all triggered ISR. However, the mutants were all as effective as the parental strain, suggesting redundancy in ISR-triggering traits in WCS358. The Botrytis cinerea-tomato, B. cinerea-bean and Colletotrichum lindemuthianum-bean model systems were used to test further the potential of P. putida WCS358 to induce ISR. Strain WCS358 significantly reduced disease development in all three systems, indicating that also on tomato and bean WCS358 can trigger ISR. In both tomato and bean, the LPS mutant had lost the ability to induce resistance, whereas the flagella mutant was still effective. In bean, the pseudobactin mutant was still effective, whereas this mutant has lost its effectivity in tomato. In both bean and tomato, flagella isolated from the parental strain were not effective, whereas LPS or pseudobactin did induce systemic resistance. PMID:20565648

Meziane, Hamid; VAN DER Sluis, Ientse; VAN Loon, Leendert C; Höfte, Monica; Bakker, Peter A H M

2005-03-01

101

Pedological characteristics of Mn mine tailings and metal accumulation by native plants  

Microsoft Academic Search

In southern China revegetation and ecological restoration of many abandoned Mn tailings has become a major concern. To determine the major constraints for plant establishment and evaluate the feasibility of remediation, a comparative study was conducted on Mn tailings and rhizosphere soils at the boundary of the tailings pond. Both tailings and rhizosphere soils had neutral to slightly alkaline pH

Xin Wang; Yunguo Liu; Guangming Zeng; Liyuan Chai; Xin Xiao; Xiaochen Song; Zongyi Min

2008-01-01

102

Phytoremediation of mine tailings in temperate and arid environments  

Microsoft Academic Search

Phytoremediation is an emerging technology for the remediation of mine tailings, a global problem for which conventional remediation\\u000a technologies are costly. There are two approaches to phytoremediation of mine tailings, phytoextraction and phytostabilization.\\u000a Phytoextraction involves translocation of heavy metals from mine tailings to the plant shoot biomass followed by plant harvest,\\u000a while phytostabilization focuses on establishing a vegetative cap that

Monica O. Mendez; Raina M. Maier

2008-01-01

103

Modelling Cometary Sodium Tails  

NASA Astrophysics Data System (ADS)

Neutral sodium is readily observed in cometary spectra and can be seen to form its own distinct tail around high activity comets. We present a brief overview of neutral sodium tail observations to date and discuss the importance of theoretical modelling in understanding these data. We have developed a new, 3D Monte-Carlo model of cometary sodium that incorporates several advancements over previous models. It includes weightings due to solar flux variation with heliocentric distance, and comprehensive handling of the Swings and Greenstein effects on the neutral sodium tail, which can have particularly dramatic effects in near-Sun comets. Some preliminary results from this model are presented, including predictions of the structure of the eagerly anticipated neutral sodium tail at Comet C/2012 S1 (ISON).

Birkett, K. S.; Jones, G. H.; Coates, A. J.

2013-09-01

104

Wagging tail vibration absorber  

NASA Technical Reports Server (NTRS)

A 750-foot cantilever length of extendible-tape boom (very low stiffness) was considered as the main system to be damped. A number of tail lengths were tried from 20 feet to 80 feet after which 40 feet was investigated further as a desirable compromise between performance and practical lengths. A 40-foot damping tail produced a damping effect on the main boom for the first mode equivalent in decay rate to 3.1 percent of critical damping. In this case the spring-hinge and tail were tuned to the main boom first mode frequency and the hinge damping was set at 30 percent of critical based on the tail properties. With this same setting, damping of the second mode was .4 percent and the third mode .1 percent.

Barclay, R. G.; Humphrey, P. W.

1969-01-01

105

Uranium Mill Tailings.  

National Technical Information Service (NTIS)

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...

L. H. McLaren

1982-01-01

106

[Tail Plane Icing  

NASA Technical Reports Server (NTRS)

The Aviation Safety Program initiated by NASA in 1997 has put greater emphasis in safety related research activities. Ice-contaminated-tailplane stall (ICTS) has been identified by the NASA Lewis Icing Technology Branch as an important activity for aircraft safety related research. The ICTS phenomenon is characterized as a sudden, often uncontrollable aircraft nose- down pitching moment, which occurs due to increased angle-of-attack of the horizontal tailplane resulting in tailplane stall. Typically, this phenomenon occurs when lowering the flaps during final approach while operating in or recently departing from icing conditions. Ice formation on the tailplane leading edge can reduce tailplane angle-of-attack range and cause flow separation resulting in a significant reduction or complete loss of aircraft pitch control. In 1993, the Federal Aviation Authority (FAA) and NASA embarked upon a four-year research program to address the problem of tailplane stall and to quantify the effect of tailplane ice accretion on aircraft performance and handling characteristics. The goals of this program, which was completed in March 1998, were to collect aerodynamic data for an aircraft tail with and without ice contamination and to develop analytical methods for predicting the effects of tailplane ice contamination. Extensive dry air and icing tunnel tests which resulted in a database of the aerodynamic effects associated with tailplane ice contamination. Although the FAA/NASA tailplane icing program generated some answers regarding ice-contaminated-tailplane stall (ICTS) phenomena, NASA researchers have found many open questions that warrant further investigation into ICTS. In addition, several aircraft manufacturers have expressed interest in a second research program to expand the database to other tail configurations and to develop experimental and computational methodologies for evaluating the ICTS phenomenon. In 1998, the icing branch at NASA Lewis initiated a second multi-phase research program for tailplane icing (TIP II) to develop test methodologies and tailplane performance and handling qualities evaluation tools. The main objectives of this new NASA/Industry/Academia collaborative research programs were: (1) define and evaluate a sub-scale wind tunnel test methodology for determining tailplane performance degradation due to icing. (2) develop an experimental database of tailplane aerodynamic performance with and without ice contamination for a range of tailplane configurations. Wind tunnel tests were planned with representative general aviation aircraft, i.e., the Learjet 45, and a twin engine low speed aircraft. This report summarizes the research performed during the first year of the study, and outlines the work tasks for the second year.

1997-01-01

107

Engineering assessment of inactive uranium mill tailings  

SciTech Connect

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.

Not Available

1981-07-01

108

The Tail Suspension Test  

PubMed Central

The tail-suspension test is a mouse behavioral test useful in the screening of potential antidepressant drugs, and assessing of other manipulations that are expected to affect depression related behaviors. Mice are suspended by their tails with tape, in such a position that it cannot escape or hold on to nearby surfaces. During this test, typically six minutes in duration, the resulting escape oriented behaviors are quantified. The tail-suspension test is a valuable tool in drug discovery for high-throughput screening of prospective antidepressant compounds. Here, we describe the details required for implementation of this test with additional emphasis on potential problems that may occur and how to avoid them. We also offer a solution to the tail climbing behavior, a common problem that renders this test useless in some mouse strains, such as the widely used C57BL/6. Specifically, we prevent tail climbing behaviors by passing mouse tails through a small plastic cylinder prior to suspension. Finally, we detail how to manually score the behaviors that are manifested in this test.

Terrillion, Chantelle E.; Piantadosi, Sean C.; Bhat, Shambhu; Gould, Todd D.

2012-01-01

109

Ecological aspects of microorganisms inhabiting uranium mill tailings  

USGS Publications Warehouse

Numbers and types of microorganisms in uranium mill tailings were determined using culturing techniques. Arthrobacter were found to be the predominant microorganism inhabiting the sandy tailings, whereas Bacillus and fungi predominated in the slime tailings. Sulfate-reducing bacteria, capable of leaching radium, were isolated in low numbers from tailings samples but were isolated in significantly high numbers from topsoil in contact with the tailings. The results are placed in the context of the magnitude of uranium mill tailings in the United States, the hazards posed by the tailings, and how such hazards could be enhanced or diminished by microbial activities. Patterns in the composition of the microbial population are evaluated with respect to the ecological variables that influence microbial growth. ?? 1987 Springer-Verlag New York Inc.

Miller, C. L.; Landa, E. R.; Updegraff, D. M.

1987-01-01

110

Ecological aspects of microorganisms inhabiting uranium mill tailings.  

PubMed

Numbers and types of microorganisms in uranium mill tailings were determined using culturing techniques.Arthrobacter were found to be the predominant microorganism inhabiting the sandy tailings, whereasBacillus and fungi predominated in the slime tailings. Sulfate-reducing bacteria, capable of leaching radium, were isolated in low numbers from tailings samples but were isolated in significantly high numbers from topsoil in contact with the tailings. The results are placed in the context of the magnitude of uranium mill tailings in the United States, the hazards posed by the tailings, and how such hazards could be enhanced or diminished by microbial activities. Patterns in the composition of the microbial population are evaluated with respect to the ecological variables that influence microbial growth. PMID:24202642

Miller, C L; Landa, E R; Updegraff, D M

1987-09-01

111

A Cytoplasmic Tail Determinant in HIV-1 Vpu Mediates Targeting of Tetherin for Endosomal Degradation and Counteracts Interferon-Induced Restriction  

PubMed Central

The HIV-1 accessory protein Vpu counteracts tetherin (BST-2/CD317) by preventing its incorporation into virions, reducing its surface expression, and ultimately promoting its degradation. Here we characterize a putative trafficking motif, EXXXLV, in the second alpha helix of the subtype-B Vpu cytoplasmic tail as being required for efficient tetherin antagonism. Mutation of this motif prevents ESCRT-dependent degradation of tetherin/Vpu complexes, tetherin cell surface downregulation, but not its physical interaction with Vpu. Importantly, this motif is required for efficient cell-free virion release from CD4+ T cells, particularly after their exposure to type-1 interferon, indicating that the ability to reduce surface tetherin levels and promote its degradation is important to counteract restriction under conditions that the virus likely encounters in vivo. Vpu EXXXLV mutants accumulate with tetherin at the cell surface and in endosomal compartments, but retain the ability to bind both ?-TrCP2 and HRS, indicating that this motif is required for a post-binding trafficking event that commits tetherin for ESCRT-dependent degradation and prevents its transit to the plasma membrane and viral budding zones. We further found that while Vpu function is dependent on clathrin, and the entire second alpha helix of the Vpu tail can be functionally complemented by a clathrin adaptor binding peptide derived from HIV-1 Nef, none of the canonical clathrin adaptors nor retromer are required for this process. Finally we show that residual activity of Vpu EXXXLV mutants requires an intact endocytic motif in tetherin, suggesting that physical association of Vpu with tetherin during its recycling may be sufficient to compromise tetherin activity to some degree.

Kueck, Tonya; Neil, Stuart J. D.

2012-01-01

112

Research on the Characterization and Conditioning of Uranium Mill Tailings. Volume 1. I. Characterization and Leaching Behavior of Uranium Mill Tailings.  

National Technical Information Service (NTIS)

The goal of these studies on tailings characterization was to determine the mineralogical and elemental composition of various tailings materials, as well as to evaluate their contaminant leachability and radon emanation properties. Extreme variability wi...

D. R. Dreesen M. E. Bunker E. J. Cokal M. M. Denton J. W. Starner

1983-01-01

113

Genetically Determined Susceptibility to Tuberculosis in Mice Causally Involves Accelerated and Enhanced Recruitment of Granulocytes  

PubMed Central

Classical twin studies and recent linkage analyses of African populations have revealed a potential involvement of host genetic factors in susceptibility or resistance to Mycobacterium tuberculosis infection. In order to identify the candidate genes involved and test their causal implication, we capitalized on the mouse model of tuberculosis, since inbred mouse strains also differ substantially in their susceptibility to infection. Two susceptible and two resistant mouse strains were aerogenically infected with 1,000 CFU of M. tuberculosis, and the regulation of gene expression was examined by Affymetrix GeneChip U74A array with total lung RNA 2 and 4 weeks postinfection. Four weeks after infection, 96 genes, many of which are involved in inflammatory cell recruitment and activation, were regulated in common. One hundred seven genes were differentially regulated in susceptible mouse strains, whereas 43 genes were differentially expressed only in resistant mice. Data mining revealed a bias towards the expression of genes involved in granulocyte pathophysiology in susceptible mice, such as an upregulation of those for the neutrophil chemoattractant LIX (CXCL5), interleukin 17 receptor, phosphoinositide kinase 3 delta, or gamma interferon-inducible protein 10. Following M. tuberculosis challenge in both airways or peritoneum, granulocytes were recruited significantly faster and at higher numbers in susceptible than in resistant mice. When granulocytes were efficiently depleted by either of two regimens at the onset of infection, only susceptible mice survived aerosol challenge with M. tuberculosis significantly longer than control mice. We conclude that initially enhanced recruitment of granulocytes contributes to susceptibility to tuberculosis.

Keller, Christine; Hoffmann, Reinhard; Lang, Roland; Brandau, Sven; Hermann, Corinna; Ehlers, Stefan

2006-01-01

114

Determinants of maltreatment substantiation in a sample of infants involved with the child welfare system  

Microsoft Academic Search

Children under one year of age are highly vulnerable to child maltreatment, which can lead to serious immediate and long-term physical and mental health consequences. Child welfare workers encounter unique challenges when assessing allegations of maltreatment involving infants. This study identifies correlates of maltreatment substantiation in a sample of 793 infants less than one year of age investigated by child

Gabriela Williams; Lil Tonmyr; Susan M. Jack; Barbara Fallon; Harriet L. MacMillan

2011-01-01

115

Determining the Impact of Block Scheduling on Leadership Involvement in the FFA  

ERIC Educational Resources Information Center

Block scheduling was established in response to educational reform measures and is the restructuring of the school day in longer class increments with fewer number of classes per day. The FFA, an intra-curricular component of the agricultural education, provides leadership opportunities and involvement within the classroom setting. This study…

Dunigan, Anne H.; Hoover, Tracy S.

2007-01-01

116

Student Perceptions of School Efforts to Facilitate Student Involvement, School Commitment, Self-Determination, and High School Graduation  

ERIC Educational Resources Information Center

This study examined the relationship between student perceptions of school efforts to facilitate student involvement, school commitment, self-determination skills, and on track indicators for graduation in 10th grade and actual graduation outcomes two years later. The participants were 154 primarily minority students in a large, urban school…

Cavendish, Wendy

2013-01-01

117

Human tail: nature's aberration.  

PubMed

Human tail refers to a congenital cutaneous appendix protruding from the lumbosacral region. It is usually associated with an underlying spina bifida occulta, a form of spinal dysraphism. A contiguous fibrolipoma can sometimes be seen extending from the subcutaneous portion of the tail into the inferior spinal cord, resulting in tethered cord syndrome. Management of such lesions includes complete neurologic examination and magnetic resonance imaging. Early diagnosis and microsurgical intervention can prevent development or progression of severe neurologic defects in later life. PMID:22241711

Kumar, Dipti; Kapoor, Akshay

2012-07-01

118

Morphogenetic changes occurring in the regenerating newt tail under changed gravity conditions  

NASA Astrophysics Data System (ADS)

It is widely accepted that gravity greatly affects animal physiology, development, and alters gene expression. Recently it became apparent that it can also affect tissue morphogenesis. In our work, we developed special laboratory conditions that allow us to produce the gravity-dependent alterations in tail regenerates of the newt Pleurodeles waltl. We examined the dynamic morphogenetic changes during 50-day tail regeneration using computer morphometric analysis. Changes that we observed under these conditions were comparable with those found earlier in our spaceflight experiments. The newts kept in aquarium deep water (low g) after 1/3 tail amputation developed normal lanceolate regenerates. In contrast, the animals that stayed on the moist mat (1g) developed tail regenerates curved ventrally, with tips almost touching the mat. The similar results were obtained with a 12-day centrifugation at 2g. The study of the regenerate morphology in low g, 1g, and 2g animal groups allowed us to determine the stage at which the morphological changes in regenerates become apparent, and to detect the main morphological events associated with the development of tail curve, such as bending of ependymal tube and reorientation of the forming cartilage. We describe cellular processes foregoing observed tissue morphogenetic changes, such as cell migration, condensation in cell population, and unequal proliferation in different areas of epidermis and blastema. Cell proliferation in epidermis and blastema of tails regenerated under the conditions of different gravitational load was evaluated by BrdU assay. In 1g newts, cell proliferation increased within the dorso-apical region of the regenerates compared with that in low g group. These results provide us with a valuable insight into the regenerative tissue homostasis that involves cell division, cell death, and migration in the newt regenerating tail. In addition, these findings could provide us with better understanding of the mechanisms mediating morphogenetic response of regenerating tissues to the modified gravity vector.

Radugina, Elena A.; Grigoryan, Eleonora N.; Dvorochkin, Natasha; Almeida, Eduardo

2012-07-01

119

Acetyl-L-carnitine suppresses thyroid hormone-induced and spontaneous anuran tadpole tail shortening.  

PubMed

Mitochondrial membrane permeability transition (MPT) plays a crucial role in apoptotic tail shortening during anuran metamorphosis. L-carnitine is known to shuttle free fatty acids (FFAs) from the cytosol into mitochondria matrix for ?-oxidation and energy production, and in a previous study we found that treatment with L-carnitine suppresses 3, 3', 5-triiodothyronine (T3 ) and FFA-induced MPT by reducing the level of FFAs. In the present study we focus on acetyl-L-carnitine, which is also involved in fatty acid oxidation, to determine its effect on T3 -induced tail regression in Rana rugosa tadpoles and spontaneous tail regression in Xenopus laevis tadpoles. The ladder-like DNA profile and increases in caspase-3 and caspase-9 indicative of apoptosis in the tails of T3 -treated tadpoles were found to be suppressed by the addition of acetyl-L-carnitine. Likewise, acetyl-L-carnitine was found to inhibit thyroid hormone regulated spontaneous metamorphosis in X. laevis tadpoles, accompanied by decreases in caspase and phospholipase A2 activity, as well as non-ladder-like DNA profiles. These findings support our previous conclusion that elevated levels of FFAs initiate MPT and activate the signaling pathway controlling apoptotic cell death in tadpole tails during anuran metamorphosis. PMID:23489246

Hanada, Hideki; Kobuchi, Hirotsugu; Yamamoto, Masanao; Kashiwagi, Keiko; Katsu, Kenjiro; Utsumi, Toshihiko; Kashiwagi, Akihiko; Sasaki, Junzo; Inoue, Masayasu; Utsumi, Kozo

2013-02-01

120

Effects of aerodynamic interaction between main and tail rotors on helicopter hover performance and noise  

NASA Technical Reports Server (NTRS)

A model test was conducted to determine the effects of aerodynamic interaction between main rotor, tail rotor, and vertical fin on helicopter performance and noise in hover out of ground effect. The experimental data were obtained from hover tests performed with a .151 scale Model 222 main rotor, tail rotor and vertical fin. Of primary interest was the effect of location of the tail rotor with respect to the main rotor. Penalties on main rotor power due to interaction with the tail rotor ranged up to 3% depending upon tail rotor location and orientation. Penalties on tail rotor power due to fin blockage alone ranged up to 10% for pusher tail rotors and up to 50% for tractor tail rotors. The main rotor wake had only a second order effect on these tail rotor/fin interactions. Design charts are presented showing the penalties on main rotor power as a function of the relative location of the tail rotor.

Menger, R. P.; Wood, T. L.; Brieger, J. T.

1983-01-01

121

An improved technique for tail-cuff blood pressure measurements with dark-tailed mice.  

PubMed

Study of the genetics of hypertension has been facilitated greatly by the use of mice with modified genes that affect blood pressure. A current successful method for measuring blood pressure in mice relies on detection of light passing through the tail to determine the pressure in a tail-cuff necessary to stop pulsed flow. Success in obtaining reliable blood pressure measurements in light-tailed strains of mice (e.g., C57BL/6J) has been excellent. However, in our and others' experience, mice having highly pigmented tails (e.g., 129S6/SvEvTac) have yielded less consistent measurements. We report here that simple modifications to the channel containing the pulse detection sensor can greatly improve the pulse detection of dark-tailed mice. The first modification--lining the sensor channel with four layers of clear plastic wrap--increased the frequency of successful blood pressure measurements of 129S6/SvEvTac mice twofold and reduced variability by one-third. The second modification--lining the sides of the channel with reflective foil--also improved the success rate with dark-tailed mice. Mean blood pressures were unaffected by these modifications, which enhance detection of the pulse wave and likely will be helpful in diverse applications in which blood pressure is measured in rodent strains with pigmented tails. PMID:16138782

Hagaman, John R; John, Simon; Xu, Lonquan; Smithies, Oliver; Maeda, Nobuyo

2005-09-01

122

Cortisol is involved in temperature-dependent sex determination in the Japanese flounder.  

PubMed

In vertebrates, sex is normally determined by genotype. However, in poikilothermal vertebrates, including reptiles, amphibians, and fishes, sex determination is greatly influenced by environmental factors, such as temperature. Little is known about the molecular mechanisms underlying environmental sex determination in these species. The Japanese flounder (Paralichthys olivaceus) is a teleost fish with an XX/XY sex determination system. However, XX flounder can be induced to develop into predominantly either phenotypic females or males, by rearing at 18 or 27 C, respectively, during the sex differentiation period. Therefore, the flounder provides an excellent model to study the molecular mechanisms underlying temperature-dependent sex determination. We previously showed that an aromatase inhibitor, an antiestrogen, and 27 C treatments cause masculinization of XX flounder, as well as suppression of mRNA expression of ovary-type aromatase (cyp19a1), a steroidogenic enzyme responsible for the conversion of androgens to estrogens in the gonads. Furthermore, estrogen administration completely inhibits masculinization by these treatments, suggesting suppression of cyp19a1 mRNA expression, and the resultant estrogen biosynthesis may trigger masculinization of the XX flounder induced by high water temperature. Here, we demonstrated that cortisol causes female-to-male sex reversal by directly suppressing cyp19a1 mRNA expression via interference with cAMP-mediated activation and that metyrapone (an inhibitor of cortisol synthesis) inhibits 27 C-induced masculinization of XX flounder. Moreover, cortisol concentrations in 27 C-reared juveniles were significantly higher than in 18 C-reared fishes during sexual differentiation. These results strongly suggest that masculinization by high water temperature is ascribable to elevation of cortisol concentration during gonadal sex differentiation in the flounder. PMID:20534725

Yamaguchi, Toshiya; Yoshinaga, Norifumi; Yazawa, Takashi; Gen, Koichiro; Kitano, Takeshi

2010-08-01

123

Long distance seed dispersal by wind: measuring and modelling the tail of the curve  

Microsoft Academic Search

The size and shape of the tail of the seed dispersal curve is important in determining the spatial dynamics of plants, but\\u000a is difficult to quantify. We devised an experimental protocol to measure long-distance dispersal which involved measuring\\u000a dispersal by wind from isolated individuals at a range of distances from the source, but maintaining a large and constant\\u000a sampling intensity

James M. Bullock; Ralph T. Clarke

2000-01-01

124

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

PubMed Central

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 (p<0.05) between these two categories of pigs. Several of these transcripts had already been shown to be differently expressed in the neutral pigs when they were compared to performers and receivers of tail biting 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.

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

2013-01-01

125

Metal mobilization under alkaline conditions in ash-covered tailings.  

PubMed

The aim of this study was to determine element mobilization and accumulation in mill tailings under alkaline conditions. The tailings were covered with 50 cm of fly ash, and above a sludge layer. The tailings were geochemically and mineralogically investigated. Sulfides, such as pyrrhotite, sphalerite and galena along with gangue minerals such as dolomite, calcite, micas, chlorite, epidote, Mn-pyroxene and rhodonite were identified in the unoxidized tailings. The dissolution of the fly ash layer resulted in a high pH (close to 12) in the underlying tailings. This, together with the presence of organic matter, increased the weathering of the tailings and mobilization of elements in the uppermost 47 cm of the tailings. All primary minerals were depleted, except quartz and feldspar which were covered by blurry secondary carbonates. Sulfide-associated elements such as Cd, Fe, Pb, S and Zn and silicate-associated elements such as Fe, Mg and Mn were released from the depletion zone and accumulated deeper down in the tailings where the pH decreased to circum-neutral. Sequential extraction suggests that Cd, Cu, Fe, Pb, S and Zn were retained deeper down in the tailings and were mainly associated with the sulfide phase. Calcium, Cr, K and Ni released from the ash layer were accumulated in the uppermost depletion zone of the tailings. PMID:24681363

Lu, Jinmei; Alakangas, Lena; Wanhainen, Christina

2014-06-15

126

REAR PROFILE OF TAIL FROM SECOND LEVEL OF TAIL DOCK ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

REAR PROFILE OF TAIL FROM SECOND LEVEL OF TAIL DOCK STAND, SHOWING AIRCRAFT NUMBER (319), HORIZONTAL STABILIZER, TAIL CONE AND COOLING CTS FOR THE AUXILIARY POWER UNIT (APU), MECHANIC PAUL RIDEOUT IS LOWERING THE BALANCE PANELS ON THE STABILIZERS FOR LUBRICATION AND INSPECTION. - Greater Buffalo International Airport, Maintenance Hangar, Buffalo, Erie County, NY

127

Ratios of bottom meson branching fractions involving J/? mesons and determination of b quark fragmentation fractions  

NASA Astrophysics Data System (ADS)

We report a measurement of the ratios of the decay rates of the B+, B0, and B0s mesons into exclusive final states containing a J/? meson. The final states were selected from 19.6 pb-1 of pp¯ collisions recorded by the Collider Detector at Fermilab. These data are interpreted to determine the b quark fragmentation fractions fu, fd, and fs. We also determine the branching fractions for the decay modes B+-->J/?K+, B+-->J/?K*(892)+, B0-->J/?K0, B0-->J/?K*(892)0, and B0s-->J/??(1020). We discuss the implications of these measurements to B meson decay models.

Abe, F.; Akimoto, H.; Akopian, A.; Albrow, M. G.; Amendolia, S. R.; Amidei, D.; Antos, J.; Anway-Wiese, C.; Aota, S.; Apollinari, G.; Asakawa, T.; Ashmanskas, W.; Atac, M.; Azfar, F.; Azzi-Bacchetta, P.; Bacchetta, N.; Badgett, W.; Bagdasarov, S.; Bailey, M. W.; Bao, J.; de Barbaro, P.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barzi, E.; Bauer, G.; Baumann, T.; Bedeschi, F.; Behrends, S.; Belforte, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Benlloch, J.; Bensinger, J.; Benton, D.; Beretvas, A.; Berge, J. P.; Berryhill, J.; Bertolucci, S.; Bevensee, B.; Bhatti, A.; Biery, K.; Binkley, M.; Bisello, D.; Blair, R. E.; Blocker, C.; Bodek, A.; Bokhari, W.; Bolla, G.; Bolognesi, V.; Bortoletto, D.; Boudreau, J.; Breccia, L.; Bromberg, C.; Bruner, N.; Buckley-Geer, E.; Budd, H. S.; Burkett, K.; Busetto, G.; Byon-Wagner, A.; Byrum, K. L.; Cammerata, J.; Campagnari, C.; Campbell, M.; Caner, A.; Carithers, W.; Carlsmith, D.; Castro, A.; Cauz, D.; Cen, Y.; Cervelli, F.; Chang, P. S.; Chang, P. T.; Chao, H. Y.; Chapman, J.; Cheng, M.-T.; Chiarelli, G.; Chikamatsu, T.; Chiou, C. N.; Christofek, L.; Cihangir, S.; Clark, A. G.; Cobal, M.; Contreras, M.; Conway, J.; Cooper, J.; Cordelli, M.; Couyoumtzelis, C.; Crane, D.; Cronin-Hennessy, D.; Culbertson, R.; Cunningham, J. D.; Daniels, T.; Dejongh, F.; Delchamps, S.; dell'agnello, S.; dell'orso, M.; Demina, R.; Demortier, L.; Denby, B.; Deninno, M.; Derwent, P. F.; Devlin, T.; Dittmann, J. R.; Donati, S.; Done, J.; Dorigo, T.; Dunn, A.; Eddy, N.; Einsweiler, K.; Elias, J. E.; Ely, R.; Engels, E.; Errede, D.; Errede, S.; Fan, Q.; Fiori, I.; Flaugher, B.; Foster, G. W.; Franklin, M.; Frautschi, M.; Freeman, J.; Friedman, J.; Fuess, T. A.; Fukui, Y.; Funaki, S.; Gagliardi, G.; Galeotti, S.; Gallinaro, M.; Garcia-Sciveres, M.; Garfinkel, A. F.; Gay, C.; Geer, S.; Gerdes, D. W.; Giannetti, P.; Giokaris, N.; Giromini, P.; Gladney, L.; Glenzinski, D.; Gold, M.; Gonzalez, J.; Gordon, A.; Goshaw, A. T.; Goulianos, K.; Grassmann, H.; Groer, L.; Grosso-Pilcher, C.; Guillian, G.; Guo, R. S.; Haber, C.; Hafen, E.; Hahn, S. R.; Hamilton, R.; Handler, R.; Hans, R. M.; Hara, K.; Hardman, A. D.; Harral, B.; Harris, R. M.; Hauger, S. A.; Hauser, J.; Hawk, C.; Hayashi, E.; Heinrich, J.; Hoffman, K. D.; Hohlmann, M.; Holck, C.; Hollebeek, R.; Holloway, L.; Hölscher, A.; Hong, S.; Houk, G.; Hu, P.; Huffman, B. T.; Hughes, R.; Huston, J.; Huth, J.; Hylen, J.; Ikeda, H.; Incagli, M.; Incandela, J.; Introzzi, G.; Iwai, J.; Iwata, Y.; Jensen, H.; Joshi, U.; Kadel, R. W.; Kajfasz, E.; Kambara, H.; Kamon, T.; Kaneko, T.; Karr, K.; Kasha, H.; Kato, Y.; Keaffaber, T. A.; Keeble, L.; Kelley, K.; Kennedy, R. D.; Kephart, R.; Kesten, P.; Kestenbaum, D.; Keup, R. M.; Keutelian, H.; Keyvan, F.; Kharadia, B.; Kim, B. J.; Kim, D. H.; Kim, H. S.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kirsch, L.; Koehn, P.; Kondo, K.; Konigsberg, J.; Kopp, S.; Kordas, K.; Korytov, A.; Koska, W.; Kovacs, E.; Kowald, W.; Krasberg, M.; Kroll, J.; Kruse, M.; Kuwabara, T.; Kuhlmann, S. E.; Kuns, E.; Laasanen, A. T.; Labanca, N.; Lammel, S.; Lamoureux, J. I.; Lecompte, T.; Leone, S.; Lewis, J. D.; Limon, P.; Lindgren, M.; Liss, T. M.; Lockyer, N.; Long, O.; Loomis, C.; Loreti, M.; Lu, J.; Lucchesi, D.; Lukens, P.; Lusin, S.; Lys, J.; Maeshima, K.; Maghakian, A.; Maksimovic, P.; Mangano, M.; Mansour, J.; Mariotti, M.; Marriner, J. P.; Martin, A.; Matthews, J. A.; Mattingly, R.; McIntyre, P.; Melese, P.; Menzione, A.; Meschi, E.; Metzler, S.; Miao, C.; Miao, T.; Michail, G.; Miller, R.; Minato, H.; Miscetti, S.; Mishina, M.; Mitsushio, H.; Miyamoto, T.; Miyashita, S.; Moggi, N.; Morita, Y.; Mueller, J.; Mukherjee, A.; Muller, T.; Murat, P.; Nakada, H.; Nakano, I.; Nelson, C.; Neuberger, D.; Newman-Holmes, C.; Ninomiya, M.; Nodulman, L.; Oh, S. H.; Ohl, K. E.; Ohmoto, T.; Ohsugi, T.; Oishi, R.; Okabe, M.; Okusawa, T.; Oliveira, R.; Olsen, J.; Pagliarone, C.; Paoletti, R.; Papadimitriou, V.; Pappas, S. P.; Park, S.; Parri, A.; Patrick, J.; Pauletta, G.; Paulini, M.; Perazzo, A.; Pescara, L.; Peters, M. D.; Phillips, T. J.; Piacentino, G.; Pillai, M.; Pitts, K. T.; Plunkett, R.; Pondrom, L.; Proudfoot, J.; Ptohos, F.; Punzi, G.; Ragan, K.; Ribon, A.; Rimondi, F.; Ristori, L.; Robertson, W. J.; Rodrigo, T.; Rolli, S.; Romano, J.; Rosenson, L.; Roser, R.; Sakumoto, W. K.; Saltzberg, D.; Sansoni, A.; Santi, L.; Sato, H.; Scarpine, V.; Schlabach, P.; Schmidt, E. E.; Schmidt, M. P.; Scribano, A.; Segler, S.; Seidel, S.; Seiya, Y.; Sganos, G.; Shapiro, M. D.; Shaw, N. M.; Shen, Q.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Siegrist, J.; Sill, A.; Sinervo, P.; Singh, P.; Skarha, J.; Sliwa, K.; Snider, F. D.; Song, T.; Spalding, J.; Speer, T.; Sphicas, P.; Spinella, F.; Spiropulu, M.; Spiegel, L.; Stanco, L.; Steele, J.; Stefanini, A.; Strahl, K.

1996-12-01

128

Notch–RBP-J signaling is involved in cell fate determination of marginal zone B cells  

Microsoft Academic Search

RBP-J is a key mediator of Notch signaling that regulates cell fate determination in various lineages. To investigate the function of Notch–RBP-J in mature B cell differentiation, we generated mice that selectively lacked B cell RBP-J expression using conditional mutagenesis. Absence of RBP-J led to the loss of marginal zone B (MZB) cells with a concomitant increase in follicular B

Kenji Tanigaki; Hua Han; Norio Yamamoto; Kei Tashiro; Masaya Ikegawa; Kazuki Kuroda; Akira Suzuki; Toru Nakano; Tasuku Honjo

2002-01-01

129

Determinants of mRNA stability in Dictyostelium discoideum amoebae: differences in poly(A) tail length, ribosome loading, and mRNA size cannot account for the heterogeneity of mRNA decay rates.  

PubMed Central

As an approach to understanding the structures and mechanisms which determine mRNA decay rates, we have cloned and begun to characterize cDNAs which encode mRNAs representative of the stability extremes in the poly(A)+ RNA population of Dictyostelium discoideum amoebae. The cDNA clones were identified in a screening procedure which was based on the occurrence of poly(A) shortening during mRNA aging. mRNA half-lives were determined by hybridization of poly(A)+ RNA, isolated from cells labeled in a 32PO4 pulse-chase, to dots of excess cloned DNA. Individual mRNAs decayed with unique first-order decay rates ranging from 0.9 to 9.6 h, indicating that the complex decay kinetics of total poly(A)+ RNA in D. discoideum amoebae reflect the sum of the decay rates of individual mRNAs. Using specific probes derived from these cDNA clones, we have compared the sizes, extents of ribosome loading, and poly(A) tail lengths of stable, moderately stable, and unstable mRNAs. We found (i) no correlation between mRNA size and decay rate; (ii) no significant difference in the number of ribosomes per unit length of stable versus unstable mRNAs, and (iii) a general inverse relationship between mRNA decay rates and poly(A) tail lengths. Collectively, these observations indicate that mRNA decay in D. discoideum amoebae cannot be explained in terms of random nucleolytic events. The possibility that specific 3'-structural determinants can confer mRNA instability is suggested by a comparison of the labeling and turnover kinetics of different actin mRNAs. A correlation was observed between the steady-state percentage of a given mRNA found in polysomes and its degree of instability; i.e., unstable mRNAs were more efficiently recruited into polysomes than stable mRNAs. Since stable mRNAs are, on average, "older" than unstable mRNAs, this correlation may reflect a translational role for mRNA modifications that change in a time-dependent manner. Our previous studies have demonstrated both a time-dependent shortening and a possible translational role for the 3' poly(A) tracts of mRNA. We suggest, therefore, that the observed differences in the translational efficiency of stable and unstable mRNAs may, in part, be attributable to differences in steady-state poly(A) tail lengths. Images

Shapiro, R A; Herrick, D; Manrow, R E; Blinder, D; Jacobson, A

1988-01-01

130

Sex determination involves synergistic action of SRY and SF1 on a specific Sox9 enhancer.  

PubMed

The mammalian Y chromosome acts as a dominant male determinant as a result of the action of a single gene, Sry, whose role in sex determination is to initiate testis rather than ovary development from early bipotential gonads. It does so by triggering the differentiation of Sertoli cells from supporting cell precursors, which would otherwise give follicle cells. The related autosomal gene Sox9 is also known from loss-of-function mutations in mice and humans to be essential for Sertoli cell differentiation; moreover, its abnormal expression in an XX gonad can lead to male development in the absence of Sry. These genetic data, together with the finding that Sox9 is upregulated in Sertoli cell precursors just after SRY expression begins, has led to the proposal that Sox9 could be directly regulated by SRY. However, the mechanism by which SRY action might affect Sox9 expression was not understood. Here we show that SRY binds to multiple elements within a Sox9 gonad-specific enhancer in mice, and that it does so along with steroidogenic factor 1 (SF1, encoded by the gene Nr5a1 (Sf1)), an orphan nuclear receptor. Mutation, co-transfection and sex-reversal studies all point to a feedforward, self-reinforcing pathway in which SF1 and SRY cooperatively upregulate Sox9 and then, together with SF1, SOX9 also binds to the enhancer to help maintain its own expression after that of SRY has ceased. Our results open up the field, permitting further characterization of the molecular mechanisms regulating sex determination and how they have evolved, as well as how they fail in cases of sex reversal. PMID:18454134

Sekido, Ryohei; Lovell-Badge, Robin

2008-06-12

131

Determination of ethyl glucuronide in hair: a rapid sample pretreatment involving simultaneous milling and extraction.  

PubMed

A combination of simultaneous milling and extraction known as micropulverized extraction was developed for the quantification of the alcohol marker ethyl glucuronide (EtG) in hair samples using a homogeneous reference material and a mixer mill. Best extraction results from 50 mg of hair were obtained with 2-mL plastic tubes containing two steel balls (? = 5 mm), 0.5 mL of water and with an oscillating frequency of 30 s(-1) over a period of 30 min. EtG was quantified employing a validated GC-MS procedure involving derivatization with pentafluoropropionic acid anhydride. This micropulverization procedure was compared with dry milling followed by separate aqueous extraction and with aqueous extraction after manual cutting to millimeter-size snippets. Micropulverization yielded 28.0?±?1.70 pg/mg and was seen to be superior to manually cutting (23.0?±?0.83 pg/mg) and equivalent to dry grinding (27.7?±?1.71 pg/mg) with regard to completeness of EtG extraction. The option to process up to 20 samples simultaneously makes micropulverization especially valuable for the high throughput of urgent samples. PMID:24221575

Mönch, Bettina; Becker, Roland; Nehls, Irene

2014-01-01

132

Left-Right Determination: Involvement of Molecular Motor KIF3, Cilia, and Nodal Flow  

PubMed Central

Mammalian left–right determination is a good example for how multiple cell biological processes coordinate in the formation of a basic body plan. The leftward movement of fluid at the ventral node, called nodal flow, is the central process in symmetry breaking on the left–right axis. Nodal flow is autonomously generated by the rotation of posteriorly tilted cilia that are built by transport via KIF3 motor on cells of the ventral node. How nodal flow is interpreted to create left–right asymmetry has been a matter of debate. Recent evidence suggests that the leftward movement of sheathed lipidic particles, called nodal vesicular parcels (NVPs), may result in the activation of the noncanonical hedgehog signaling pathway, an asymmetric elevation in intracellular Ca2+ and changes in gene expression.

Hirokawa, Nobutaka; Tanaka, Yosuke; Okada, Yasushi

2009-01-01

133

Evidence for current sheet acceleration in the geomagnetic tail  

Microsoft Academic Search

The existence of the current sheet and the dawn to dusk electric field in the geomagnetic tail implies there is particle energization in the tail current sheet of the order 2--10% of the total solar wind energy incident upon the dayside magnetopause. In this paper we determine that ion acceleration in a current sheet with a small magnetic field across

L. R. Lyons; T. W. Speiser

1982-01-01

134

Faun tail nevus  

PubMed Central

Faun tail nevus is a posterior midline cutaneous lesion of importance to dermatologists as it could be a cutaneous marker for its underlying spine and spinal cord anomaly. We report a 13-year-old girl with excessive hair growth over the lumbosacral region since birth. There was associated spinal anomaly with no neurological manifestation affecting the lower spinal cord. The diagnosis was made on clinical basis. The patient reported for cosmetic disability. This case is reported for its clinical importance.

Yamini, M.; Sridevi, K. S.; Babu, N. Prasanna; Chetty, Nanjappa G.

2011-01-01

135

Identification of Determinants Involved in Initiation of Hepatitis C Virus RNA Synthesis by Using Intergenotypic Replicase Chimeras  

Microsoft Academic Search

The 5 nontranslated region (NTR) and the X tail in the 3 NTR are the least variable parts of the hepatitis C virus (HCV) genome and play an important role in the initiation of RNA synthesis. By using subgenomic replicons of the HCV isolates Con1 (genotype 1) and JFH1 (genotype 2), we characterized the genotype specificities of the replication signals

Marco Binder; Doris Quinkert; Olga Bochkarova; Rahel Klein; Nikolina Kezmic; Ralf Bartenschlager; Volker Lohmann

2007-01-01

136

The tail plane  

NASA Technical Reports Server (NTRS)

This report deals with the calculation of the equilibrium, statistical stability, and damping of the tail plane. The author has simplified the present theory of longitudinal stability for the particular purpose of obtaining one definite coefficient characteristics of the effect of the tail plane. This coefficient is obtained by substituting certain aerodynamic characteristics and some dimensions of the airplane in a comparatively simple mathematical expression. Care has been taken to confine all aerodynamical information necessary for the calculation of the coefficient to the well-known curves representing the qualities of the wing section. This is done by making use of the present results of modern aerodynamics. All formulas and relations necessary for the calculation are contained in the paper. They give in some cases only an approximation of the real values. An example of calculation is added in order to illustrate the application of the method. The coefficient indicates not only whether the effect of the tail plane is great enough, but also whether it is not too great. It appears that the designer has to avoid a certain critical length of the fuselage, which inevitably gives rise to periodical oscillations of the airplane. The discussion also shows the way and in what direction to carry out experimental work.

Munk, Max M

1923-01-01

137

Remote control canard missile with a free-rolling tail brake torque system  

NASA Technical Reports Server (NTRS)

An experimental wind-tunnel investigation has been conducted at supersonic Mach numbers to determine the static aerodynamic characteristics of a cruciform canard-controlled missile with fixed and free-rolling tail-fin afterbodies. Mechanical coupling effects of the free-rolling tail afterbody were investigated using an electronic/electromagnetic brake system that provides arbitrary tail-fin brake torques with continuous measurements of tail-to-mainframe torque and tail-roll rate. Results are summarized to show the effects of fixed and free-rolling tail-fin afterbodies that include simulated measured bearing friction torques on the longitudinal and lateral-directional aerodynamic characteristics.

Blair, A. B., Jr.

1981-01-01

138

Structural conservation of the Myoviridae phage tail sheath protein fold  

PubMed Central

Bacteriophage phiKZ is a giant phage that infects Pseudomonas aeruginosa, a human pathogen. The phiKZ virion consists of a 1450 Å diameter icosahedral head and a 2000 Å-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 Å resolution. Furthermore, crystal structures of two prophage tail sheath proteins were determined to 1.9 and 3.3 Å 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.

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

2011-01-01

139

The geomagnetic tail  

SciTech Connect

A review is presented of the plasma sheet and lobe regions of the magnetotail, focusing principally on large-scale processes or microprocesses with some large-scale effects. Consideration is given to quiet and average structures, not necessarily related to activity phases, with quasi-steady convection aspects, and with the characteristics of dynamic phases including acceleration mechanisms and single particle aspects. Attention is given to various activity models, average and quiet time properties, properties and effects of magnetospheric convection, dynamics of the magnetotail, and the near tail, substorm current wedge.

Birn, J. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

1991-01-01

140

The effect of biting tails and having tails bitten in pigs.  

PubMed

Tail-biting is a behavioral abnormality which compromises the welfare of pigs. The goal of this study was to characterize the tail-biting phenotype using behavior and measures of heart-rate (HR) and its variability (HRV) in pigs. Thirty pigs were categorized as tail-biters (n=10), tail-bite victims (n=10), and control pigs (n=10) based on the frequency of tail-biting behavior that they performed or received at the farm. The animals' behavioral responses were registered at the experimental facilities for 10 min during test sessions whereas physiological responses were registered for 10 min prior to (basal) and during sessions when subjected to a novel object test (NOT) and to a novel arena test (NAT). Phenotypes differed in most behaviors during the two tests and in the NOT their physiological responses suggested different regulation of vagal tone. Biters had a reduction from baseline values to values during testing for the root mean square of successive R-R intervals (RMSSD) and the high-frequency band (HF) compared to victims, whose RMSSD and HF increased from baseline to test values. In the low-frequency band (LF), an increase was shown in biters and controls while a decrease in victims. LF was found to be strongly positively correlated with HF and RMSSD in biters. During baseline, victims tended to have lower HF and significantly higher power of the low-frequency component divided by power of the high-frequency band (LF:HF ratio) compared to biters and controls. The activity of the autonomic nervous system, especially the suppression of parasympathetic tone, indicated that both victims and biters may have a dysfunctional autonomic regulation which may indicate psychological disturbance. We provide the first documentation of phenotypic differences between pigs that have performed tail-biting, have been victimized, or have not been involved in tail biting using HRV data. PMID:22579933

Zupan, Manja; Janczak, Andrew M; Framstad, Tore; Zanella, Adroaldo J

2012-07-16

141

Calculation of the number of cancer deaths prevented by the Uranium Mill Tailings Remedial Action Project  

Microsoft Academic Search

The Uranium Mill Tailings Remedial Action Project has completed remedial action at 22 uranium mill tailings sites and about 5,000 properties (vicinity properties) where tailings were used in construction, at a total cost of $1.45 billion. This paper uses existing data from Environmental Impact Statements and Environmental Assessments, and vicinity property calculations, to determine the total number of cancer deaths

Mark L. Miller; C. B. Pomatto; R. E. Cornish

1999-01-01

142

Band tails in hydrogenated amorphous silicon and silicon-germanium alloys  

Microsoft Academic Search

The temperature dependence of the conduction- and valence-band tails has been determined by total-photoelectron-yield spectroscopy for doped and undoped a-Si:H and a-SiGe:H alloys. We find that all films possess purely exponential conduction- and valence-band-tail densities of states; however, the characteristic energy of the conduction-band tail increases much more rapidly with temperature than that of the valence-band tail. This indicates that

Samer Aljishi; J. David Cohen; Shu Jin; Lothar Ley

1990-01-01

143

Helicopter Tail-Boom Strakes  

NASA Technical Reports Server (NTRS)

Yaw control and overall efficiency increased at hover and low speeds. Wind-tunnel investigation showed strake located on left side of tail boom has potential to reduce high adverse side loads on tail boom in hover and in sideward flight. Test demonstrated addition of single long strake to left side of tail boom most effective configuration for reducing left pedal requirements in right sideward flight.

Kelley, H. L.; Phelps, A. E., III; Wilson, J. C.

1986-01-01

144

Western Red-tailed Skink Distribution in Southern Nevada  

SciTech Connect

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.

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

2011-11-01

145

Determination of fecundity in American plaice ( Hippoglossoides platessoides) and its variation from 1987 to 1989 on the tail of the Grand Bank  

NASA Astrophysics Data System (ADS)

The American plaice shows 'group synchronous' oocyte development, with fecundity determined at the beginning of vitellogenesis (May). There is neither new recruitment of vitellogenic oocytes during gonad development nor are there important losses by atretic processes. The annual mean percentage of vitellogenic oocytes in alpha atretic stage was 0.29. For the range of sizes analysed (50 to 55 cm), the relative fecundity (fecundity per female weight) was very constant in Division NAFO 3N, with a mean value of 409 eggs per gram of female weight, but there were changes in the somatic index (9%), and subsequently in the length-fecundity relationship.

Zamarro, Javier

146

Uranium mill tailings and radon  

SciTech Connect

The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is extremely small. If the assumptions used in the studies are correct, one or two people per year in the US may develop cancer as a result of radon exhaled from all the Uranium Mill Tailings Remedial Action Program sites. The remedial action should reduce the hazard from the tailings by a factor of about 100.

Hanchey, L A

1981-01-01

147

Uranium mill tailings and radon  

SciTech Connect

The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is extremely small. If the assumptions used in the studies are correct, one or two people per year in the United States may develop cancer as a result of radon exhaled from all the Uranium Mill Tailings Remedial Action program sites. The remedial action should reduce the hazard from the tailings by a factor of about 100.

Hanchey, L A

1981-04-01

148

Accelerated aging tests of liners for uranium mill tailings disposal  

SciTech Connect

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.

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

1981-11-01

149

3. VIEW OF WEST TAILING DAM, LARGE TANK, AND TAILING, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. VIEW OF WEST TAILING DAM, LARGE TANK, AND TAILING, LOOKING NORTHEAST. A SIX-FOOT SCALE IS LOCATED AGAINST WALL ON LEFT. PURPOSE OF TANK IS UNKNOWN, BUT APPEARS TO HAVE FALLEN FROM ITS ORIGINAL LOCATION AT THE MILL SITE, UP AND TO THE RIGHT OF THIS VIEW. - Skidoo Mine, Park Route 38 (Skidoo Road), Death Valley Junction, Inyo County, CA

150

Economic evaluation of inactive uranium mill tailings, Gunnison Site, Gunnison, Colorado  

SciTech Connect

Mountain States Research and Development was contracted on March 1, 1981 to make an economic evaluation study at each of 12 abandoned uranium mill tailings sites in the western states. The objective of this work was to obtain the data necessary at each site to determine the possible revenue that could be derived from reprocessing the tailings. To accomplish this objective a drilling and sampling program was established for each site to determine the total amount of tailings and subbase material available for treatment and the amount of recoverable uranium, vanadium and molybdenum. These three metals were selected due to their common occurrence in uranium ores and common extractability in the leaching process. Laboratory leaching was then conducted on the samples obtained to determine the extractability of each of these metals and the optimum plant process to be applied. As the metal contents were generally low and represented mineral that had not been leached during previous processing, the economic evaluation is limited to consideration of the direct capital and operating costs required in connection with processing of each respective site material. Excavating, transportation and disposal of the material from each site in an environmentally acceptable location and manner was not within the scope of this project. It will be necessary to complete a separate study of these areas in order to determine the total costs involved. This report contains the results of the investigations of the Old Rifle Site.

Teel, J H [Mountain States Research and Development, Tucson, AZ (United States)

1982-12-01

151

Migration of arsenic from old tailings ponds-A case study on the King Edward Mine, Cornwall, UK  

SciTech Connect

A methodology is presented to study the physico-chemical processes in old tailings ponds using an array of analytical-physical chemistry approaches. A case study was conducted on the sorption/desorption behaviour of arsenic in tailings pond 2406, at the King Edward Mine (KEM) in Cornwall, UK. The tailings pond was in operation from approximately 1907 to 1921. The methodology involves two principal stages: (1) sequential extraction followed by subsequent arsenic species determination to characterise the material with regards to the association of arsenic with soil phases and identification of As (III/V) in the easily accessible soil phase; (2) batch contacting/equilibrating the tailings pond material with As(III/V), followed by a similar procedure as in stage 1 to establish the material's As(III/V) phase distribution kinetics/thermodynamics. By extrapolating the data from present day samples we infer past and future elemental mobility. From this study it is concluded that adsorption and desorption from tailings material is a rapid process for the most unstable soil phases (non-specific and specific) and a slow process for the more stable phases (poorly crystalline and well crystalline). The hypothetical application of this conclusion to the tailings from dam 2406 is that, during the initial phases of the dam's creation (ca. 100 years ago), when arsenic was both in solution and bound to mineralogical components, arsenic must have dispersed into the environment as a result of slow As(V) adsorption/phase distribution processes. Aging of the tailings material sees the movement of the arsenic to the more stable soil phases, producing a situation that is seen at present day.

Beeston, Michael Philip [National Institute of Chemistry (Kiribati), Hajdrihova 19, SI-1001 Ljubljana (Slovenia); University of Exeter in Cornwall (UEC), Tremough Campus, TR10 9EZ Penryn, Cornwall (United Kingdom)], E-mail: Michael.Beeston@ki.si; Tuen van Elteren, Johannes [National Institute of Chemistry (Kiribati), Hajdrihova 19, SI-1001 Ljubljana (Slovenia); Slejkovec, Zdenka [Jozef Stefan Institute (JSI), Jamova 39, SI-1000 Ljubljana (Slovenia); Glass, Hylke Jan [University of Exeter in Cornwall (UEC), Tremough Campus, TR10 9EZ Penryn, Cornwall (United Kingdom)

2008-09-15

152

Experiments on a tail-wheel shimmy  

NASA Technical Reports Server (NTRS)

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.

Harling, R; Dietz, O

1954-01-01

153

Use of gold mill tailings in making bricks: a feasibility study.  

PubMed

Mill tailings dumps at Kolar Gold Fields, Karnataka, are creating environmental problems. One of the solutions to these problems is to use the mill tailings for some useful purpose. This study examined the possibility of making bricks from the mill tailings with some additives in laboratory experiments. Samples of the mill tailings and the additives were analysed for particle size distribution, Atterberg limits and specific gravity. The plasticity index of the mill tailings being zero, they could not be used directly for making bricks. Therefore some additives that had plasticity or binding properties were mixed with the mill tailings. Ordinary Portland cement, black cotton soils and red soils were selected as additives. Each of the additives was mixed separately with the mill tailings in different proportions by weight and a large number of bricks were prepared using metallic moulds. The bricks were termed as cement-tailings bricks or soil-tailings bricks, depending on the additives used. The cement-tailings bricks were cured for different periods and their corresponding compressive strengths were determined. The bricks with 20% of cement and 14 days of curing were found to be suitable. The soil-tailings bricks were sun-dried and then fired in a furnace at different temperatures. The quality of bricks was assessed in terms of linear shrinkage, water absorption and compressive strength. The cost analysis revealed that cement-tailings bricks would be uneconomical whereas the soil-tailings bricks would be very economical. PMID:17985673

Roy, Surendra; Adhikari, Govind R; Gupta, Rama N

2007-10-01

154

Teratoma in Human Tail Lipoma  

Microsoft Academic Search

We report a case of a rare congenital teratoma that developed in a lipoma attached to a remnant human tail. A male newborn baby presented with a large, 3-cm mass with an open margin, which pedunculated from a tail attached to the midline skin of the coccygeal area. Magnetic resonance images demonstrated multiple sacral spinal bifida without cord tethering, and

Se-Hyuck Park; Jee Soon Huh; Ki Hong Cho; Yong Sam Shin; Se Hyck Kim; Young Hwan Ahn; Kyung Gi Cho; Soo Han Yoon

2005-01-01

155

Helicopter Tail Rotor Noise Analyses.  

National Technical Information Service (NTIS)

A study was made of helicopter tail rotor noise, particularly that due to interactions with the main rotor tip vortices, and with the fuselage separation mean wake. The tail rotor blade-main rotor tip vortex interaction is modelled as an airfoil of infini...

A. R. George S. T. Chou

1986-01-01

156

Uranium Mill Tailings and Radon.  

National Technical Information Service (NTIS)

The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is e...

L. A. Hanchey

1981-01-01

157

Human tail with spina bifida.  

PubMed

A true human tail is a rare occurrence and is defined as a caudal, vestigial, midline protrusion with skin covering connective tissue, muscle, vessels and nerves. We report a case of true human tail in a child, which is a very rare happening in humans. PMID:19922280

Chauhan, S P S; Gopal, N N; Jain, Mohit; Gupta, Anurag

2009-12-01

158

Recombinants of Bean common mosaic virus (BCMV) and Genetic Determinants of BCMV Involved in Overcoming Resistance in Common Bean.  

PubMed

ABSTRACT Bean common mosaic virus (BCMV) exists as a complex of strains classified by reactions to resistance genes found in common bean (Phaseolus vulgaris); seven BCMV pathotypes have been distinguished thus far, numbered I to VII. Virus genetic determinants involved in pathogenicity interactions with resistance genes have not yet been identified. Here, we describe the characterization of two novel field isolates of BCMV that helped to narrow down these genetic determinants interacting with specific P. vulgaris resistance factors. Based on a biological characterization on common bean differentials, both isolates were classified as belonging to pathotype VII, similar to control isolate US10, and both isolates exhibited the B serotype. The whole genome was sequenced for both isolates and found to be 98 to 99% identical to the BCMV isolate RU1 (pathotype VI), and a single name was retained: BCMV RU1-OR. To identify a genetic determinant of BCMV linked to the BCMV pathotype VII, the whole genome was also sequenced for two control isolates, US10 and RU1-P. Inspection of the nucleotide sequences for BCMV RU1-OR and US10 (both pathotype VII) and three closely related sequences of BCMV (RU1-P, RU1-D, and RU1-W, all pathotype VI) revealed that RU1-OR originated through a series of recombination events between US10 and an as-yet-unidentified BCMV parental genome, resulting in changes in virus pathology. The data obtained suggest that a fragment of the RU1-OR genome between positions 723 and 1,961 nucleotides that is common to US10 and RU1-OR in the P1-HC-Pro region of the BCMV genome may be responsible for the ability to overcome resistance in bean conferred by the bc-2(2) gene. This is the first report of a virus genetic determinant responsible for overcoming a specific BCMV resistance gene in common bean. PMID:24915430

Feng, Xue; Poplawsky, Alan R; Nikolaeva, Olga V; Myers, James R; Karasev, Alexander V

2014-07-01

159

Congenital Sensorineural Deafness in Australian Stumpy-Tail Cattle Dogs Is an Autosomal Recessive Trait That Maps to CFA10  

Microsoft Academic Search

BackgroundCongenital sensorineural deafness is an inherited condition found in many dog breeds, including Australian Stumpy-tail Cattle Dogs (ASCD). This deafness is evident in young pups and may affect one ear (unilateral) or both ears (bilateral). The genetic locus\\/loci involved is unknown for all dog breeds. The aims of this study were to determine incidence, inheritance mechanism, and possible association of

Susan Sommerlad; Allan F. McRae; Brenda McDonald; Isobel Johnstone; Leigh Cuttell; Jennifer M. Seddon; Caroline A. OLeary

2010-01-01

160

Derivation and implementation of an annual limit on intake and a derived air concentration value for uranium mill tailings  

Microsoft Academic Search

Monitoring workers and work areas at the Department of Energy Uranium Mill Tailings Remedial Action Project sites is complex because all radionuclides in the ²³⁸U and ²³⁵U decay chains may be present in an airborne uranium mill tillings matrix. Previous monitoring practices involved isotopic analysis of the air filter to determine the activity of each radionuclide of concern and comparing

R. H. Reif; D. W. Andrews

1995-01-01

161

Runaway tails in magnetized plasmas  

NASA Technical Reports Server (NTRS)

The evolution of a runaway tail driven by a dc electric field in a magnetized plasma is analyzed. Depending on the strength of the electric field and the ratio of plasma to gyrofrequency, there are three different regimes in the evolution of the tail. The tail can be (1) stable with electrons accelerated to large parallel velocities, (2) unstable to Cerenkov resonance because of the depletion of the bulk and the formation of a positive slope, (3) unstable to the anomalous Doppler resonance instability driven by the large velocity anisotropy in the tail. Once an instability is triggered (Cerenkov or anomalous Doppler resonance) the tail relaxes into an isotropic distribution. The role of a convection type loss term is also discussed.

Moghaddam-Taaheri, E.; Vlahos, L.; Rowland, H. L.; Papadopoulos, K.

1985-01-01

162

Missile rolling tail brake torque system  

NASA Astrophysics Data System (ADS)

Apparatus for simulating varying levels of friction in the bearings of a free rolling tail afterbody on a canard-controlled missile to determine friction effects on aerodynamic control characteristics is described. A ring located between the missile body and the afterbody is utilized in a servo system to create varying levels of friction between the missile body and the afterbody to simulate bearing friction.

Davis, W. T.

1984-01-01

163

Radon emanation from backfilled mill tailings in underground uranium mine.  

PubMed

Coarser mill tailings used as backfill to stabilize the stoped out areas in underground uranium mines is a potential source of radon contamination. This paper presents the quantitative assessment of radon emanation from the backfilled tailings in Jaduguda mine, India using a cylindrical accumulator. Some of the important parameters such as (226)Ra activity concentration, bulk density, bulk porosity, moisture content and radon emanation factor of the tailings affecting radon emanation were determined in the laboratory. The study revealed that the radon emanation rate of the tailings varied in the range of 0.12-7.03 Bq m(-2) s(-1) with geometric mean of 1.01 Bq m(-2) s(-1) and geometric standard deviation of 3.39. An increase in radon emanation rate was noticed up to a moisture saturation of 0.09 in the tailings, after which the emanation rate gradually started declining with saturation due to low diffusion coefficient of radon in the saturated tailings. Radon emanation factor of the tailings varied in the range of 0.08-0.23 with the mean value of 0.21. The emanation factor of the tailings with moisture saturation level over 0.09 was found to be about three times higher than that of the absolutely dry tailings. The empirical relationship obtained between (222)Rn emanation rate and (226)Ra activity concentration of the tailings indicated a significant positive linear correlation (r = 0.95, p < 0.001). This relationship may be useful for quick prediction of radon emanation rate from the backfill material of similar nature. PMID:24412814

Sahu, Patitapaban; Mishra, Devi Prasad; Panigrahi, Durga Charan; Jha, Vivekananda; Patnaik, R Lokeswara; Sethy, Narendra Kumar

2014-04-01

164

Recovery of Potash Feldspar from Molybdenite Tailings.  

National Technical Information Service (NTIS)

The Bureau of Mines used several laboratory batch flotation schemes combined with magnetic separation to investigate the feasibility of recovering potash feldspar and glass sands from molybdenite tailings. Four molybdenite tailings or prospective tailings...

W. H. Eddy G. V. Sullivan

1980-01-01

165

Elucidating Internucleosome Interactions and the Roles of Histone Tails  

PubMed Central

The nucleosome is the first level of genome organization and regulation in eukaryotes where negatively charged DNA is wrapped around largely positively charged histone proteins. Interaction between nucleosomes is dominated by electrostatics at long range and guided by specific contacts at short range, particularly involving their flexible histone tails. We have thus quantified how internucleosome interactions are modulated by salts (KCl, MgCl2) and histone tail deletions (H3, H4 N-terminal), using small-angle x-ray scattering and theoretical modeling. We found that measured effective charges at low salts are ?1/5th of the theoretically predicted renormalized charges and that H4 tail deletion suppresses the attraction at high salts to a larger extent than H3 tail deletion.

Howell, Steven C.; Andresen, Kurt; Jimenez-Useche, Isabel; Yuan, Chongli; Qiu, Xiangyun

2013-01-01

166

Analysis of the effects of wing interference on the tail contributions to the rolling derivatives  

NASA Technical Reports Server (NTRS)

An analysis of the effects of wing interference on the tail contributions to the rolling stability derivatives of complete airplane configurations is made by calculating the angularity of the air stream at the vertical tail due to rolling and determining the resulting forces and moments. Some of the important factors which affect the resultant angularity on the vertical tail are wing aspect ratio and sweepback, vertical-tail span, and considerations associated with angle of attack and airplane geometry. Some calculated sidewash results for a limited range of plan forms and vertical-tail sizes are presented. Equations taking into account the sidewash results are given for determining the tail contributions to the rolling derivatives. Comparisons of estimated and experimental results indicate that a consideration of wing interference effects improves the estimated values of the tail contributions to the rolling derivatives and that fair agreement with available experimental data is obtained.

Michael, William H , Jr

1952-01-01

167

Helicopter tail rotor noise analyses  

NASA Technical Reports Server (NTRS)

A study was made of helicopter tail rotor noise, particularly that due to interactions with the main rotor tip vortices, and with the fuselage separation mean wake. The tail rotor blade-main rotor tip vortex interaction is modelled as an airfoil of infinite span cutting through a moving vortex. The vortex and the geometry information required by the analyses are obtained through a free wake geometry analysis of the main rotor. The acoustic pressure-time histories for the tail rotor blade-vortex interactions are then calculated. These acoustic results are compared to tail rotor loading and thickness noise, and are found to be significant to the overall tail rotor noise generation. Under most helicopter operating conditions, large acoustic pressure fluctuations can be generated due to a series of skewed main rotor tip vortices passing through the tail rotor disk. The noise generation depends strongly upon the helicopter operating conditions and the location of the tail rotor relative to the main rotor.

George, A. R.; Chou, S. T.

1986-01-01

168

Interactions of tailings leachate with local liner materials found at Canonsburg, Pennsylvania.  

SciTech Connect

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/sup 3/ (70,000 yd/sup 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/sub 4/, NO/sub 3/, and Cl. Of these soluble contaminants, uranium-238, radium-226, the trace metals As and Mo, and the anions F and SO/sub 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 (<10/sup -8/ cm/s) were observed for even slightly compacted tailings materials.

Dodson, M.E.; Gee, G.W.; Serne, R.J.

1984-04-01

169

Mercury's Dynamic Magnetic Tail  

NASA Technical Reports Server (NTRS)

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.

Slavin, James A.

2010-01-01

170

Naturally Occurring Tuberculosis in White-Tailed Deer  

Microsoft Academic Search

Objective—To determine the distribution of lesions and extent of tissues infected with Mycobacterium bovis in a captive population of white-tailed deer. Design—Cross-sectional study. Animals—116 captive white-tailed deer. Procedure—Deer were euthanatized, and postmortem examinations were performed. Tissues with gross lesions suggestive of tuberculosis were collected for microscopic analysis and bacteriologic culture. Tissues from the head, thorax, and abdomen of deer with

Mitchell V. Palmer; Diana L. Whipple; Janet B. Payeur; David P. Alt; Kevin J. Esch; Colleen S. Bruning-Fann; John B. Kaneene

2000-01-01

171

Tail Lobe Revisited: Magnetic Field Modeling Based on Plasma Data  

NASA Technical Reports Server (NTRS)

Plasma data from the ISEE-1 and -2 spacecraft during 1977-1980 have been used to determine the distribution of data points in the magnetotail in the range of distances -20 < XGSM < --15, i.e. which of the records that were located in the current sheet, in the tail lobe, in the magnetosheath and in the boundary layers respectively. The ISEE-1 and -2 magnetic field data for the records in the tail lobe were then used to model the tail lobe magnetic field dependence on the solar wind dynamic pressure, on the Interplanetary Magnetic Field (IMF) and on the Dst index. The tail lobe magnetic field was assumed to be dependent on the square root of the dynamic pressure based on the balance between the total magnetic pressure in the tail lobes and the dynamic pressure of the solar wind. The IMF dependent terms, added to the pressure term, were sought in many different forms while the Dst dependence of the tail lobe magnetic field was assumed to be linear. The field shows a strong dependence on the square root of the dynamic pressure and the different IMF dependent terms all constitute a significant contribution to the total field. However, the dependence on the Dst index turned out to be very weak at those down-tail distances. The results of this study are intended to be used for parameterizing future versions of the data-based models of the global magnetospheric magnetic field.

Karlsson, S. B. P.; Tsyganenko, N. A.

1999-01-01

172

Determining protein adducts of fipexide: mass spectrometry based assay for confirming the involvement of its reactive metabolite in covalent binding.  

PubMed

Fipexide is a nootropic drug, withdrawn from the market due to its idiosyncratic drug reactions causing adverse effects in man. Previous work on its metabolites has identified several potential reactive metabolites which could be implicated in protein binding. Here, we investigated the formation of these metabolites in rat and human hepatocytes. Based on these results, the o-quinone of fipexide (FIP), formed via the demethylenation reaction through a catechol intermediate, was chosen for further investigation. Studies were then pursued in order to relate this metabolite to protein binding, and thus better understand potential mechanisms for the toxicity of the parent compound. An assay was developed for determining the fipexide catechol-cysteine adduct in the microsomal protein fractions following in vitro incubations. This method digests the entire protein fraction into amino acids, followed by the detection of the Cys-metabolite adduct by liquid chromatography/mass spectrometry (LC/MS). We have designed a strategy where drug metabolism taking place in microsomal incubations and involved in protein binding can be assessed after the proteins have been digested, with the detection of the specific amino acid adduct. In this study, the structure of the fipexide adduct was hypothesized using knowledge previously gained in glutathione and N-acetylcysteine trapping experiments. Acetaminophen was used as a positive control for detecting a drug metabolite-cysteine adduct by LC/MS. This approach has the potential to be applicable as a protein-binding assay in early drug discovery without the need for radioactive compounds. PMID:18022964

Sleno, Lekha; Varesio, Emmanuel; Hopfgartner, Gérard

2007-01-01

173

An unbiased approach to identify genes involved in development in a turtle with temperature-dependent sex determination  

PubMed Central

Background Many reptiles exhibit temperature-dependent sex determination (TSD). The initial cue in TSD is incubation temperature, unlike genotypic sex determination (GSD) where it is determined by the presence of specific alleles (or genetic loci). We used patterns of gene expression to identify candidates for genes with a role in TSD and other developmental processes without making a priori assumptions about the identity of these genes (ortholog-based approach). We identified genes with sexually dimorphic mRNA accumulation during the temperature sensitive period of development in the Red-eared slider turtle (Trachemys scripta), a turtle with TSD. Genes with differential mRNA accumulation in response to estrogen (estradiol-17?; E2) exposure and developmental stages were also identified. Results Sequencing 767 clones from three suppression-subtractive hybridization libraries yielded a total of 581 unique sequences. Screening a macroarray with a subset of those sequences revealed a total of 26 genes that exhibited differential mRNA accumulation: 16 female biased and 10 male biased. Additional analyses revealed that C16ORF62 (an unknown gene) and MALAT1 (a long noncoding RNA) exhibited increased mRNA accumulation at the male producing temperature relative to the female producing temperature during embryonic sexual development. Finally, we identified four genes (C16ORF62, CCT3, MMP2, and NFIB) that exhibited a stage effect and five genes (C16ORF62, CCT3, MMP2, NFIB and NOTCH2) showed a response to E2 exposure. Conclusions Here we report a survey of genes identified using patterns of mRNA accumulation during embryonic development in a turtle with TSD. Many previous studies have focused on examining the turtle orthologs of genes involved in mammalian development. Although valuable, the limitations of this approach are exemplified by our identification of two genes (MALAT1 and C16ORF62) that are sexually dimorphic during embryonic development. MALAT1 is a noncoding RNA that has not been implicated in sexual differentiation in other vertebrates and C16ORF62 has an unknown function. Our results revealed genes that are candidates for having roles in turtle embryonic development, including TSD, and highlight the need to expand our search parameters beyond protein-coding genes.

2012-01-01

174

Bearing capacity of desiccated tailings  

SciTech Connect

The development of matric suctions in soils contributes to their shear strength, resulting in an enhanced factor of safety against bearing-capacity failure. In this paper, matric suction profiles of desiccated mine tailings are predicted from a steady-state solution for evaporative conditions, and from an isothermal mathematical model that simulates liquid and vapor water flow through soils. The shear-strength envelope with respect to matric suction is established by testing reconstituted tailings samples in a modified triaxial cell, in which matric suction can be controlled. The contribution of matric suction to the shear strength is interpreted as an additional apparent cohesion for use in bearing-capacity calculations. Because of the nonlinearity of the shear-strength profile, a numerical method of analysis is adopted to predict the ultimate bearing capacity of the desiccated tailings. A subsequent decrease in bearing capacity following 2D water infiltration into a partially capped tailings deposit and accompanying suction loss is investigated.

Rassam, D.W.; Williams, D.J. [Univ. of Queensland, Brisbane, Queensland (Australia). Dept. of Civil Engineering] [Univ. of Queensland, Brisbane, Queensland (Australia). Dept. of Civil Engineering

1999-07-01

175

Theseus Tail Being Unloaded  

NASA Technical Reports Server (NTRS)

The tail of the Theseus prototype research aircraft is seen here being unloaded at NASA's Dryden Flight Research Center, Edwards, California, in May of 1996. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite-based global environmental change measurements. Dryden's Project Manager was John Del Frate.

1996-01-01

176

The structure of comet tails  

NASA Technical Reports Server (NTRS)

Present models of the plasma tails of comets are described. The interaction of the solar wind with ions from the cometary atmosphere is discussed, and the phenomenon of magnetic reconnection observed in plasma tails is explained. The accomplishments of the ICE mission to the Comet Giacobini-Zinner are summarized, and the tasks and expected contributions from upcoming Soviet, European, and Japanese missions to Comet Halley are addressed.

Brandt, J. C.; Niedner, M. B., Jr.

1986-01-01

177

Financial Risk and Heavy Tails  

Microsoft Academic Search

It is of great importance for those in charge of managing risk to understand how financial asset returns are distributed. Practitioners often assume for convenience that the distribution is normal. Since the 1960s, however, empirical evidence has led many to reject this assumption in favor of various heavy-tailed alternatives. In a heavy-tailed distribution the likelihood that one encounters significant deviations

Brendan O. Bradley; Murad S. Taqqu

2001-01-01

178

Sirenomelia apus with vestigial tail.  

PubMed

Sirenomelia is an exceptionally rare congenital malformation characterized by complete or near complete fusion of lower limbs. A newborn with clinical features of sirenomelia including fused lower limbs in medial position, absent fibula, anal atresia, complete absence of urogenital system (bilateral renal agenesis, absent ureters, urinary bladder, absent internal and external genitalia), a single umbilical artery and a vestigial tail is reported. Association of vestigial tail with sirenomelia is not described in the literature. PMID:15876775

Parikh, Tushar B; Nanavati, Ruchi N; Udani, Rekha H

2005-04-01

179

Improved Tail-Current Representation in the Rice Field Model  

NASA Astrophysics Data System (ADS)

The Rice Field Model (RFM) represents the magnetic field of the steady-state open magnetosphere. In order to improve the mapping of field lines in the near Earth region, the simple Harris-sheet field representing the cross-tail current is replaced near the Earth by a more flexible tail current model developed by Hilmer and Voigt In the far-tail region the tail current and expansion fan fields are modified to allow for variations in the IMF and the interconnection field down the tail. The new tail-current is completely shielded by the magnetopause current system. The effects of time-dependent IMF on the polar cap potential pattern are explored by propagating a Northward turning down the tail. To evaluate the new tail-current in the near Earth region, magnetometer data from the GOES-8 satellite (in geosynchronous orbit) for the period of March 9-17, 1998 is compared to model predictions. The combination of RFM shielding with the Hilmer-Voigt tail-current proves significantly more accurate in determining the magnetic field at GEO than either of the two models alone. Ding, C., T. W. Hill, and F. R. Toffoletto. Improvement of the Toffoletto-Hill Open Magnetospheric Model, in Physics of Space Plasmas (1995): Proceedings of the 1995 Cambridge Syposium/Workshop in Geoplasma Physics on "Multiscale Phenomena in Space Plasmas", edited by T. Chang, and J.R. Jasperse, pp. 639-644, MIT Center for Theoretical Geo/Cosmo Plasma Physics, Cambridge, Massachusetts, 1996.

Naehr, S.; Toffoletto, F. R.

2001-05-01

180

The pressure distribution over the horizontal tail surfaces of an airplane I  

NASA Technical Reports Server (NTRS)

This work was undertaken to determine as completely as possible the distribution of pressure over the horizontal tail surfaces of an airplane, and to analyze the relation of this pressure to the structural loads and the longitudinal stability. The investigation is divided into three parts, of which this the first. The first part of the investigation is for the purpose of determining the pressure distribution over two horizontal tail surfaces in uniform free flight; the second part to conduct tests of similar tail planes in the wind tunnel; and the third part to determine the pressure distribution on the horizontal tail surfaces during accelerated flight on the full-size airplane.

Norton, F H

1923-01-01

181

Brain gene expression differences are associated with abnormal tail biting behavior in pigs.  

PubMed

Knowledge about gene expression in animals involved in abnormal behaviors can contribute to the understanding of underlying biological mechanisms. This study aimed to explore the motivational background to tail biting, an abnormal injurious behavior and severe welfare problem in pig production. Affymetrix microarrays were used to investigate gene expression differences in the hypothalamus and prefrontal cortex of pigs performing tail biting, pigs receiving bites to the tail and neutral pigs who were not involved in the behavior. In the hypothalamus, 32 transcripts were differentially expressed (P < 0.05) when tail biters were compared with neutral pigs, 130 when comparing receiver pigs with neutrals, and two when tail biters were compared with receivers. In the prefrontal cortex, seven transcripts were differently expressed in tail biters when compared with neutrals, seven in receivers vs. neutrals and none in the tail biters vs. receivers. In total, 19 genes showed a different expression pattern in neutral pigs when compared with both performers and receivers. This implies that the functions of these may provide knowledge about why the neutral pigs are not involved in tail biting behavior as performers or receivers. Among these 19 transcripts were genes associated with production traits in pigs (PDK4), sociality in humans and mice (GTF2I) and novelty seeking in humans (EGF). These are in line with hypotheses linking tail biting with reduced back fat thickness and explorative behavior. PMID:23146156

Brunberg, E; Jensen, P; Isaksson, A; Keeling, L J

2013-03-01

182

Active Alu Element "A-Tails": Size Does Matter  

PubMed Central

Long and short interspersed elements (LINEs and SINEs) are retroelements that make up almost half of the human genome. L1 and Alu represent the most prolific human LINE and SINE families, respectively. Only a few Alu elements are able to retropose, and the factors determining their retroposition capacity are poorly understood. The data presented in this paper indicate that the length of Alu “A-tails” is one of the principal factors in determining the retropositional capability of an Alu element. The A stretches of the Alu subfamilies analyzed, both old (Alu S and J) and young (Ya5), had a Poisson distribution of A-tail lengths with a mean size of 21 and 26, respectively. In contrast, the A-tails of very recent Alu insertions (disease causing) were all between 40 and 97 bp in length. The L1 elements analyzed displayed a similar tendency, in which the “disease”-associated elements have much longer A-tails (mean of 77) than do the elements even from the young Ta subfamily (mean of 41). Analysis of the draft sequence of the human genome showed that only about 1000 of the over one million Alu elements have tails of 40 or more adenosine residues in length. The presence of these long A stretches shows a strong bias toward the actively amplifying subfamilies, consistent with their playing a major role in the amplification process. Evaluation of the 19 Alu elements retrieved from the draft sequence of the human genome that are identical to the Alu Ya5a2 insert in the NF1 gene showed that only five have tails with 40 or more adenosine residues. Sequence analysis of the loci with the Alu elements containing the longest A-tails (7 of the 19) from the genomes of the NF1 patient and the father revealed that there are at least two loci with A-tails long enough to serve as source elements within our model. Analysis of the A-tail lengths of 12 Ya5a2 elements in diverse human population groups showed substantial variability in both the Alu A-tail length and sequence homogeneity. On the basis of these observations, a model is presented for the role of A-tail length in determining which Alu elements are active. [The sequence data from this study have been submitted to GenBank under accession nos. AF504933–AF505511.

Roy-Engel, Astrid M.; Salem, Abdel-Halim; Oyeniran, Oluwatosin O.; Deininger, Lisa; Hedges, Dale J.; Kilroy, Gail E.; Batzer, Mark A.; Deininger, Prescott L.

2002-01-01

183

SUBAQUEOUS DISPOSAL OF MILL TAILINGS  

SciTech Connect

A study of mill tailings and sulfide minerals was carried out in order to understand their behavior under subaqueous conditions. A series of electrochemical experiments, namely, cyclic voltammetry, electrochemical impedance spectroscopy and galvanic coupling tests were carried out in artificial seawater and in pH 6.8 buffer solutions with chloride and ferric salts. Two mill tailings samples, one from the Kensington Mine, Alaska, and the other from the Holden Mine, Washington, were studied along with pyrite, galena, chalcopyrite and copper-activated sphalerite. SEM analysis of mill tailings revealed absence of sulfide minerals from the Kensington Mine mill tailings, whereas the Holden Mine mill tailings contained approximately 8% pyrite and 1% sphalerite. In order to conduct electrochemical tests, carbon matrix composite (CMC) electrodes of mill tailings, pyrite and galena were prepared and their feasibility was established by conducting a series of cyclic voltammetry tests. The cyclic voltammetry experiments carried out in artificial seawater and pH 6.8 buffer with chloride salts showed that chloride ions play an important role in the redox processes of sulfide minerals. For pyrite and galena, peaks were observed for the formation of chloride complexes, whereas pitting behavior was observed for the CMC electrodes of the Kensington Mine mill tailings. The electrochemical impedance spectroscopy conducted in artificial seawater provided with the Nyquist plots of pyrite and galena. The Nyquist plots of pyrite and galena exhibited an inert range of potential indicating a slower rate of leaching of sulfide minerals in marine environments. The galvanic coupling experiments were carried out to study the oxidation of sulfide minerals in the absence of oxygen. It was shown that in the absence of oxygen, ferric (Fe3+) ions might oxidize the sulfide minerals, thereby releasing undesirable oxidation products in the marine environment. The source of Fe{sup 3{minus}} ions may be attributed to iron-bearing sulfide (and oxide) minerals present in the mill tailings. However, the concentration of available Fe{sup 3{minus}} ions can be reduced by the precipitation of insoluble ferric hydroxides (Fe(OH ){sub 3}) by seawater due to its near neutral pH. In such case, the oxidation of a sulfide mineral is inhibited due to the absence of an oxidizing agent (viz. oxygen and/or Fe{sup 3+} ions). The experiments carried out in this study provided a better understanding of behavior of sulfide minerals and mill tailings in subaqueous conditions and may be useful for further investigation of sulfide minerals and mill tailings in other environments.

Neeraj K. Mendiratta; Roe-Hoan Yoon; Paul Richardson

1999-09-03

184

Development of a biologically inspired hydrobot tail  

NASA Astrophysics Data System (ADS)

It has been hypothesized that Europa, one of the moons of Jupiter, has a large ocean underneath a thick layer of ice. In order to determine whether life exists, it has been proposed that an underwater glider (hydrobot) capable of propulsion could be sent to explore the vast ocean. In this research, we considered various smart materials to create a propulsion device inspired by dolphin tails. Dolphins are highly efficient and excellent gliders, which makes them the ideal candidate for ocean exploration. In order to select the best dolphin species, we began by reviewing literature and then utilized the Analytical Hierarchy Process (AHP) to compare the different species. Lagenorhynchus obliquidens (Pacific White-Sided Dolphin) was found to be the best choice for creating a bioinspired hydrobot. We then conducted literature review of various smart materials and using this knowledge constructed a hydrobot tail prototype. This prototype demonstrates that smart materials can be fashioned into suitable actuators to control a tail fashioned after a dolphin.

Moore, Danielle; Janneh, Alhaji; Philen, Michael

2014-04-01

185

The Pressure Distribution over the Wings and Tail Surfaces of a PW-9 Pursuit Airplane in Flight  

NASA Technical Reports Server (NTRS)

This report presents the results of an investigation to determine (1) the magnitude and distribution of aerodynamic loads over the wings and tail surfaces of a pursuit-type airplane in the maneuvers likely to impose critical loads on the various subassemblies of the airplane structure. (2) To study the phenomenon of center of pressure movement and normal force coefficient variation in accelerated flight, and (3) to measure the normal accelerations at the center of gravity, wing-tip, and tail, in order to determine the nature of the inertia forces acting simultaneously with the critical aerodynamic loads. The results obtained throw light on a number of important questions involving structural design. Some of the more interesting results are discussed in some detail, but in general the report is for the purpose of making this collection of airplane-load data obtained in flight available to those interested in airplane structures.

Rhode, Richard

1931-01-01

186

Does climate have heavy tails?  

NASA Astrophysics Data System (ADS)

When we speak about a distribution with heavy tails, we are referring to the probability of the existence of extreme values will be relatively large. Several heavy-tail models are constructed from Poisson processes, which are the most tractable models. Among such processes, one of the most important are the Lévy processes, which are those process with independent, stationary increments and stochastic continuity. If the random component of a climate process that generates the data exhibits a heavy-tail distribution, and if that fact is ignored by assuming a finite-variance distribution, then there would be serious consequences (in the form, e.g., of bias) for the analysis of extreme values. Yet, it appears that it is an open question to what extent and degree climate data exhibit heavy-tail phenomena. We present a study about the statistical inference in the presence of heavy-tail distribution. In particular, we explore (1) the estimation of tail index of the marginal distribution using several estimation techniques (e.g., Hill estimator, Pickands estimator) and (2) the power of hypothesis tests. The performance of the different methods are compared using artificial time-series by means of Monte Carlo experiments. We systematically apply the heavy tail inference to observed climate data, in particular we focus on time series data. We study several proxy and directly observed climate variables from the instrumental period, the Holocene and the Pleistocene. This work receives financial support from the European Commission (Marie Curie Initial Training Network LINC, No. 289447, within the 7th Framework Programme).

Bermejo, Miguel; Mudelsee, Manfred

2013-04-01

187

Sex Differences in the Right Tail of Cognitive Abilities: A 30 Year Examination  

ERIC Educational Resources Information Center

One factor in the debate surrounding the underrepresentation of women in science technology, engineering and mathematics (STEM) involves male-female mathematical ability differences in the extreme right tail (top 1% in ability). The present study provides male-female ability ratios from over 1.6 million 7th grade students in the right tail (top 5%…

Wai, Jonathan; Cacchio, Megan; Putallaz, Martha; Makel, Matthew C.

2010-01-01

188

Detailed determination of the nuclear fusion radius by a simultaneous optical model calculation of elastic scattering and fusion cross sections in reactions involving weakly bound projectiles  

SciTech Connect

Within the optical model for direct reactions, simultaneous calculations of elastic scattering, complete fusion, and total reaction cross sections for energies around the Coulomb barrier are presented for reactions involving the weakly bound projectile {sup 9}Be on {sup 64}Zn. Volume (W{sub F}) and surface (W{sub DR}) Woods-Saxon optical potentials are used such that the former is responsible only for complete fusion reactions while the latter for all direct reactions plus incomplete fusion. Simultaneous fits can be obtained with several sets of potential parameters, but if we impose the condition that the strength of W{sub F} is smaller than the strength of W{sub DR} at the tail region of the potential (this condition is discussed in detail), then values are required for r{sub F} and r{sub DR} of around 1.6 and 1.7-1.9 fm, respectively. These values are much larger than those frequently used in barrier penetration model calculations. Through the energy dependence of the real and imaginary parts of the polarization potentials, we show that the usual threshold anomaly does not show up for this system, but instead there is evidence of the presence of a breakup threshold anomaly.

Camacho, A. Gomez; Aguilera, E. F. [Departamento del Acelerador, Instituto Nacional de Investigaciones Nucleares, Apartado Postal 18-1027, C.P. 11801, Mexico, D.F. (Mexico); Gomes, P. R. S.; Lubian, J. [Instituto de Fisica, Universidade Federal Fluminense, Av. Litiranea s/n, Gragoata, Niteroi, R.J., 24210-340 (Brazil); Padron, I. [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear (CEADEN), Playa, Ciudad de la Habana (Cuba)

2007-10-15

189

Experimental study of main rotor tip geometry and tail rotor interactions in hover. Volume 2: Run log and tabulated data  

NASA Technical Reports Server (NTRS)

A model scale hover test was conducted in the Sikorsky Aircraft Model Rotor hover Facility to identify and quantify the impact of the tail rotor on the demonstrated advantages of advanced geometry tip configurations. The existence of mutual interference between hovering main rotor and a tail rotor was acknowledged in the test. The test was conducted using the Basic Model Test Rig and two scaled main rotor systems, one representing a 1/5.727 scale UH-60A BLACK HAWK and the others a 1/4.71 scale S-76. Eight alternate rotor tip configurations were tested, 3 on the BLACK HAWK rotor and 6 on the S-76 rotor. Four of these tips were then selected for testing in close proximity to an operating tail rotor (operating in both tractor and pusher modes) to determine if the performance advantages that could be obtained from the use of advanced geometry tips in a main rotor only environment would still exist in the more complex flow field involving a tail rotor. This volume contains the test run log and tabulated data.

Balch, D. T.; Lombardi, J.

1985-01-01

190

Experimental study of main rotor tip geometry and tail rotor interactions in hover. Volume 1. Text and figures  

NASA Technical Reports Server (NTRS)

A model scale hover test was conducted in the Sikorsky Aircraft Model rotor hover Facility to identify and quantify the impact of the tail rotor on the demonstrated advantages of advanced geometry tip configurations. The test was conducted using the Basic Model Test Rig and two scaled main rotor systems, one representing a 1/5.727 scale UH-60A BLACK HAWK and the others a 1/4.71 scale S-76. Eight alternate rotor tip configurations were tested, 3 on the BLACK HAWK rotor and 6 on the S-76 rotor. Four of these tips were then selected for testing in close proximity to an operating tail rotor (operating in both tractor and pusher modes) to determine if the performance advantages that could be obtained from the use of advanced geometry tips in a main rotor only environment would still exist in the more complex flow field involving a tail rotor. The test showed that overall the tail rotor effects on the advanced tip configurations tested are not substantially different from the effects on conventional tips.

Balch, D. T.; Lombardi, J.

1985-01-01

191

Cleavage by signal peptide peptidase is required for the degradation of selected tail-anchored proteins.  

PubMed

The regulated turnover of endoplasmic reticulum (ER)-resident membrane proteins requires their extraction from the membrane lipid bilayer and subsequent proteasome-mediated degradation. Cleavage within the transmembrane domain provides an attractive mechanism to facilitate protein dislocation but has never been shown for endogenous substrates. To determine whether intramembrane proteolysis, specifically cleavage by the intramembrane-cleaving aspartyl protease signal peptide peptidase (SPP), is involved in this pathway, we generated an SPP-specific somatic cell knockout. In a stable isotope labeling by amino acids in cell culture-based proteomics screen, we identified HO-1 (heme oxygenase-1), the rate-limiting enzyme in the degradation of heme to biliverdin, as a novel SPP substrate. Intramembrane cleavage by catalytically active SPP provided the primary proteolytic step required for the extraction and subsequent proteasome-dependent degradation of HO-1, an ER-resident tail-anchored protein. SPP-mediated proteolysis was not limited to HO-1 but was required for the dislocation and degradation of additional tail-anchored ER-resident proteins. Our study identifies tail-anchored proteins as novel SPP substrates and a specific requirement for SPP-mediated intramembrane cleavage in protein turnover. PMID:24958774

Boname, Jessica M; Bloor, Stuart; Wandel, Michal P; Nathan, James A; Antrobus, Robin; Dingwell, Kevin S; Thurston, Teresa L; Smith, Duncan L; Smith, James C; Randow, Felix; Lehner, Paul J

2014-06-23

192

Pitx2, a Bicoid-Type Homeobox Gene, Is Involved in a Lefty-Signaling Pathway in Determination of Left-Right Asymmetry  

Microsoft Academic Search

Signaling molecules such as Activin, Sonic hedgehog, Nodal, Lefty, and Vg1 have been found to be involved in determination of left-right (L-R) asymmetry in the chick, mouse, or frog. However, a common signaling pathway has not yet been identified in vertebrates. We report that Pitx2, a bicoid-type homeobox gene expressed asymmetrically in the left lateral plate mesoderm, may be involved

Hidefumi Yoshioka; Chikara Meno; Kazuko Koshiba; Minoru Sugihara; Hiroyuki Itoh; Yoshiyasu Ishimaru; Takashi Inoue; Hideyo Ohuchi; Elena V Semina; Jeffrey C Murray; Hiroshi Hamada; Sumihare Noji

1998-01-01

193

Long-term stabilization of uranium mill tailings  

SciTech Connect

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%.

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

1983-01-01

194

Tail venting for enhanced yaw damping at spinning conditions  

NASA Technical Reports Server (NTRS)

An investigation was conducted in the NASA Langley 20-ft Vertical Spin Tunnel to determine the spin and spin-recovery characteristics of a 1/11-scale model of a low-wing general aviation airplane with a horizontal tail modified with variable-size gaps to allow ventilation of the vertical stabilizer and rudder. Erect spins at symmetric loadings were tested with varying gap sizes on either or both sides of the horizontal tail. The model results indicate that the basic airplane (with no gaps) exhibits a fast, flat spin from which no recoveries can be obtained. The airplane with the modified tail has either a fast, flat spin from which no recoveries or poor recoveries may be made, or a slower, steeper spin from which fair to excellent recoveries may be obtained, depending on the size and orientation of the tail gaps. The major contribution to spin recovery was from the gap on the leeward side of the tail. Gap widths of 15-25 percent of the tail semispan were needed to produce satisfactory recovery from the flat spin.

Stough, H. P., III; Whipple, Raymond D.; Fremaux, C. M.

1991-01-01

195

Distribution of Sulfide and Oxide Copper in Copper Mill Tailings.  

National Technical Information Service (NTIS)

Studies were made to determine the character and distribution of the copper lost in copper mill tailings. Acid soluble (oxide) and acid insoluble (sulfide) copper were determined for heavy-liquid sink and float products of screen-sized fractions from 12 c...

A. R. Rule J. C. White

1971-01-01

196

Magnetospheric Substorms and Tail Dynamics  

NASA Technical Reports Server (NTRS)

This grant funded several studies of magnetospheric substorms and their effect on the dynamics of the earth's geomagnetic tail. We completed an extensive study of plasmoids, plasma/magnetic field structures that travel rapidly down the tail, using data from the ISEE 3 and IMP 8 spacecraft. This study formed the PhD thesis of Mark Moldwin. We found that magnetically plasmoids are better described as flux-ropes (twisted magnetic flux tubes) rather than plasma bubbles, as had been generally regarded up to that point (Moldwin and Hughes, 1990; 1991). We published several examples of plasmoids observed first in the near tail by IMP 8 and later in the distant tail by ISEE 3, confirming their velocities down tail. We showed how the passage of plasmoids distorts the plasma sheet. We completed the first extensive statistical survey of plasmoids that showed how plasmoids evolve as they move down tail from their formation around 30 RE to ISEE 3 apogee at 240 RE. We established a one-to-one correspondence between the observation of plasmoids in the distant tail and substorm onsets at earth or in the near tail. And we showed that there is a class of plasmoid-like structures that move slowly earthward, especially following weak substorms during northward IMF. Collectively this work constituted the most extensive study of plasmoids prior to the work that has now been done with the GEOTAIL spacecraft. Following our work on plasmoids, we turned our attention to signatures of substorm onset observed in the inner magnetosphere near geosynchronous orbit, especially signatures observed by the CRRES satellite. Using data from the magnetometer, electric field probe, plasma wave instrument, and low energy plasma instrument on CRRES we were able to better document substorm onsets in the inner magnetosphere than had been possible previously. Detailed calculation of the Poynting flux showed energy exchange between the magnetosphere and ionosphere, and a short burst of tailward convective flow just prior to onset, suggesting the active role of the ionosphere in the onset process, and adding credibility to the ballooning instability theory of substorm onset. This grant also supported a number of other substorm studies and reviews. These are represented by the list of publications and meeting presentations resulting out of this grant.

Hughes, W. Jeffrey

1998-01-01

197

Determinants of Substance Abuse in a Population of Children and Adolescents Involved with the Child Welfare System  

ERIC Educational Resources Information Center

Substance abuse is an important health issue facing children involved with child welfare, but little is known about the associated factors. The purpose of this study was to build on findings from the "Canadian Incidence Study of Reported Child Abuse and Neglect-2003" and use a national sample of 10-15 year old children to examine the factors…

Singh, Veeran-Anne S.; Thornton, Tiffany; Tonmyr, Lil

2011-01-01

198

Recent radiochemistry observations at the Riverton and Maybell tailings piles  

SciTech Connect

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 ..gamma..-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.

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

1982-09-01

199

Black-Tailed Prairie Dog  

USGS Multimedia Gallery

Black-tailed prairie dogs are quite susceptible to sylvatic plague, but a new plague vaccine put in their food shows significant promise in the laboratory. The prairie dogs transmit the disease to endangered black-footed ferrets, who eat the prairie dogs and are also quite susceptible to the disease...

2009-08-03

200

Estimating Tails of Probability Distributions  

Microsoft Academic Search

We study the asymptotic properties of estimators of the tail of a distribution based on the excesses over a threshold. A key idea is the use of Pickands' generalised Pareto distribution and its fitting, in most cases, by the method of maximum likelihood. The results cover all three limiting types of extreme value theory. We propose a new estimator for

Richard L. Smith

1987-01-01

201

Characterization of Emergent Data Networks Among Long-Tail Data  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

202

Tail tip necrosis in Ontario beef feedlot cattle  

PubMed Central

Studies were performed to establish the prevalence and importance of tail tip necrosis in the southern Ontario beef feedlot industry and to characterize the gross appearance and histopathology of the condition. In a mail survey, 96% of 71 feedlots with slatted floors, but only 5% of 184 feedlots with solid floors, reported a problem with tail tip necrosis from 1982-1986. Treatments reported included antibiotics, amputation of the tail (therapeutic or preventive), and slaughter. Lameness was associated with tail tip necrosis. A scoring system for severity of necrosis was developed. Repeated inspections revealed that mild lesions were unlikely to progress to more severe stages. Histological alterations such as perivascular edema and hemorrhage, dermal scarring, follicular atrophy, and paucity of leukocytes were compatible with cutaneous ischemia. Of 441 tails inspected at slaughter plants, 34.5% were affected, with 3.4% involving skin lacerations and infection, and 4.3% amputated before slaughter. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7.Figure 8.

Drolia, Helen; Luescher, U. Andrew; Meek, Alan H.; Wilcock, Brian P.

1991-01-01

203

A feedback regulatory loop involving microRNA9 and nuclear receptor TLX in neural stem cell fate determination  

Microsoft Academic Search

MicroRNAs have been implicated as having important roles in stem cell biology. MicroRNA-9 (miR-9) is expressed specifically in neurogenic areas of the brain and may be involved in neural stem cell self-renewal and differentiation. We showed previously that the nuclear receptor TLX is an essential regulator of neural stem cell self-renewal. Here we show that miR-9 suppresses TLX expression to

Chunnian Zhao; GuoQiang Sun; Shengxiu Li; Yanhong Shi

2009-01-01

204

Determinants of Substance Abuse in a Population of Children and Adolescents Involved with the Child Welfare System  

Microsoft Academic Search

Substance abuse is an important health issue facing children involved with child welfare, but little is known about the associated\\u000a factors. The purpose of this study was to build on findings from the Canadian Incidence Study of Reported Child Abuse and Neglect-2003 and use a national sample of 10–15 year old children to examine the factors associated with substance abuse for

Veeran-Anne S. Singh; Tiffany Thornton; Lil Tonmyr

205

French Multicenter Study Involving Eight Test Sites for Radiometric Determination of Activities of 10 Antimicrobial Agents againstMycobacterium aviumComplex  

Microsoft Academic Search

The radiometric BACTEC 460-TB methodology hasfilled an increased need in the screening of a wide range of antimicrobial agents against Mycobacterium avium (MAC) isolates on a patient-to-patient basis. In this context, a multicenter study involving eight test sites across France was performed to determine the MICs of 10 antimicrobial agents for MAC organisms. The aim of the investigation was to

NALIN RASTOGI; ROSINE-MARIE BAURIAUD; ANNE BOURGOIN; BERNARD CARBONNELLE; CLAUDE CHIPPAUX; MARIE-JOSE GEVAUDAN; KHYE SENG GOH

206

8 CFR 1208.31 - Reasonable fear of persecution or torture determinations involving aliens ordered removed under...  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Reasonable fear of persecution or torture determinations...ASYLUM AND WITHHOLDING OF REMOVAL Credible Fear of Persecution § 1208.31 Reasonable fear of persecution or torture...

2009-01-01

207

Transportation of the MOAB Uranium Mill Tailings to White Mesa Mill by Slurry Pipeline  

SciTech Connect

The Moab uranium mill tailings pile, located at the former Atlas Minerals Corporation site approximately three miles north of Moab, Utah, is now under the control of the US Department of Energy (''DOE''). The location of the tailings pile adjacent to the Colorado River, and the ongoing contamination of groundwater and seepage of pollutants into the river, have lead to the investigation, as part of the final site remediation program, of alternatives to relocate the tailings to a qualified permanent disposal site. This paper will describe the approach being taken by the team formed between International Uranium (USA) Corporation (''IUC'') and Washington Group International (''WGINT'') to develop an innovative technical proposal to relocate the Moab tailings to IUC's White Mesa Mill south of Blanding, Utah. The proposed approach for relocating the tailings involves using a slurry pipeline to transport the tailings to the White Mesa Mill. The White Mesa Mill is a fully licensed, active uranium mill site that is uniquely suited for permanent disposal of the Moab tailings. The tailings slurry would be dewatered at the White Mesa Mill, the slurry water would be recycled to the Moab site for reuse in slurry makeup, and the ''dry'' tailings would be permanently disposed of in an approved below grade cell at the mill site.

Hochstein, R. F.; Warner, R.; Wetz, T. V.

2003-02-26

208

Turbo decoding with tail-biting trellises  

Microsoft Academic Search

Tail-biting codes are considered as component codes for parallel concatenated block codes. Based on the two-dimensional weight distribution of tail-biting codes, we calculate the minimum distance of the parallel concatenated code and give guidelines on how to choose good tail-biting component codes. We show how to encode tail-biting codes using systematic feedback encoders, which is an important design criterion. The

C. Weiss; Christian Bettstetter; Sven Riedel

1998-01-01

209

On near-tail bubble penetration into geosynchronous altitude  

NASA Astrophysics Data System (ADS)

Dipolarization of the magnetic field at the near-Earth tail is usually associated with the local reduction of pV5/3 compared to that of the background, where p is the plasma pressure and V is the volume of the unit magnetic flux tube. This can be interpreted as a bubble, which can propagate earthward by the interchange process. How deep such a bubble can penetrate earthward, and what is the critical factor are critical questions that need to be answered. In this paper, we examine these issues by comparing near-tail observations by inner probes of THEMIS with geosynchronous magnetic observations by GOES. We identified a number of bubble events associated with near-tail dipolarization, which we call “tail bubble,” and checked geosynchronous disturbances. We find a statistical trend that geosynchronous disturbance is more likely to occur when associated with (or when hit by) an earthward moving tail bubble with a more-depleted pV5/3. We estimated the background pV5/3 profile statistically and used it to determine expected equilibrium (or stop) positions for earthward moving bubbles where the bubble's pV5/3 is equal to that of the background. Statistically, we find that the equilibrium position is more inward for tail bubbles with a lower pV5/3, for which the probability of causing geosynchronous disturbance is higher. For example, the probability of a tail bubble being associated with geosynchronous disturbance is 75% if the bubble's equilibrium position is <8 RE. However, for all the events studied here, the bubble equilibrium positions are still outside the geosynchronous altitude. Although this result may be subject to change due to the uncertainty in estimating pV5/3 and the limited number of the events identified near geosynchronous altitude, we suggest that an overshooting of the penetrating bubbles beyond equilibrium positions is a possible explanation.

Kim, H.-S.; Lee, D.-Y.; Ohtani, S.; Park, M.-Y.; Ahn, B.-H.

2012-07-01

210

Atomic Structure of Bacteriophage Sf6 Tail Needle Knob*  

PubMed Central

Podoviridae are double-stranded DNA bacteriophages that use short, non-contractile tails to adsorb to the host cell surface. Within the tail apparatus of P22-like phages, a dedicated fiber known as the “tail needle” likely functions as a cell envelope-penetrating device to promote ejection of viral DNA inside the host. In Sf6, a P22-like phage that infects Shigella flexneri, the tail needle presents a C-terminal globular knob. This knob, absent in phage P22 but shared in other members of the P22-like genus, represents the outermost exposed tip of the virion that contacts the host cell surface. Here, we report a crystal structure of the Sf6 tail needle knob determined at 1.0 ? resolution. The structure reveals a trimeric globular domain of the TNF fold structurally superimposable with that of the tail-less phage PRD1 spike protein P5 and the adenovirus knob, domains that in both viruses function in receptor binding. However, P22-like phages are not known to utilize a protein receptor and are thought to directly penetrate the host surface. At 1.0 ? resolution, we identified three equivalents of l-glutamic acid (l-Glu) bound to each subunit interface. Although intimately bound to the protein, l-Glu does not increase the structural stability of the trimer nor it affects its ability to self-trimerize in vitro. In analogy to P22 gp26, we suggest the tail needle of phage Sf6 is ejected through the bacterial cell envelope during infection and its C-terminal knob is threaded through peptidoglycan pores formed by glycan strands.

Bhardwaj, Anshul; Molineux, Ian J.; Casjens, Sherwood R.; Cingolani, Gino

2011-01-01

211

Tail Dependence for Heavy-Tailed Scale Mixtures of Multivariate Distributions  

Microsoft Academic Search

The tail dependence of multivariate distributions is frequently studied via the tool of copulas. This paper develops a general method, which is based on multivariate regular variation, to evaluate the tail dependence of heavy-tailed scale mixtures of multivariate distributions, whose copulas are not explicitly accessible. Tractable formulas for tail dependence parameters are derived, and a sucient condition under which the

Haijun Li; Yannan Grace Sun

212

Derivation and implementation of an annual limit on intake and a derived air concentration value for uranium mill tailings  

SciTech Connect

Monitoring workers and work areas at the Department of Energy Uranium Mill Tailings Remedial Action Project sites is complex because all radionuclides in the {sup 238}U and {sup 235}U decay chains may be present in an airborne uranium mill tillings matrix. Previous monitoring practices involved isotopic analysis of the air filter to determine the activity of each radionuclide of concern and comparing the results to the specified derived air concentration. The annual limit on intake and derived air concentration values have been derived here for the uranium mill tailings matrix to simplify the procedure for evaluation of air monitoring results and assessment of the need for individual monitoring. Implementation of the derived air concentration for uranium mill tailings involves analyzing air samples for long-lived gross alpha activity and comparing the activity concentration to the derived air concentration. Health physics decisions regarding assessment of airborne concentrations is more cost-effective because isotopic analysis of air samples is not necessary. 12 refs., 2 tabs.

Reif, R.H. [Dept. of Energy, Albuquerque, NM (United States); Andrews, D.W. [RUST Federal Services, Albuquerque, NM (United States)

1995-06-01

213

The opening of the SPP1 bacteriophage tail, a prevalent mechanism in Gram-positive-infecting siphophages.  

PubMed

The SPP1 siphophage uses its long non-contractile tail and tail tip to recognize and infect the Gram-positive bacterium Bacillus subtilis. The tail-end cap and its attached tip are the critical components for host recognition and opening of the tail tube for genome exit. In the present work, we determined the cryo-electron microscopic (cryo-EM) structure of a complex formed by the cap protein gp19.1 (Dit) and the N terminus of the downstream protein of gp19.1 in the SPP1 genome, gp21(1-552) (Tal). This complex assembles two back-to-back stacked gp19.1 ring hexamers, interacting loosely, and two gp21(1-552) trimers interacting with gp19.1 at both ends of the stack. Remarkably, one gp21(1-552) trimer displays a "closed" conformation, whereas the second is "open" delineating a central channel. The two conformational states dock nicely into the EM map of the SPP1 cap domain, respectively, before and after DNA release. Moreover, the open/closed conformations of gp19.1-gp21(1-552) are consistent with the structures of the corresponding proteins in the siphophage p2 baseplate, where the Tal protein (ORF16) attached to the ring of Dit (ORF15) was also found to adopt these two conformations. Therefore, the present contribution allowed us to revisit the SPP1 tail distal-end architectural organization. Considering the sequence conservation among Dit and the N-terminal region of Tal-like proteins in Gram-positive-infecting Siphoviridae, it also reveals the Tal opening mechanism as a hallmark of siphophages probably involved in the generation of the firing signal initiating the cascade of events that lead to phage DNA release in vivo. PMID:21622577

Goulet, Adeline; Lai-Kee-Him, Joséphine; Veesler, David; Auzat, Isabelle; Robin, Gautier; Shepherd, Dale A; Ashcroft, Alison E; Richard, Eric; Lichière, Julie; Tavares, Paulo; Cambillau, Christian; Bron, Patrick

2011-07-15

214

Sex chromosome aberrations and stature: deduction of the principal factors involved in the determination of adult height  

Microsoft Academic Search

Although sex chromosome aberrations are frequently associated with statural changes, the underlying factors have not been clarified. To define the factors leading to the statural changes, we took the following three steps: (1) determination of the mean adult height in non-mosaic Caucasian patients with sex chromosome aberrations reported in the literature (assessment of genetic height potential); (2) assessment of the

Tsutomu Ogata; Nobutake Matsuo

1993-01-01

215

Molecular Determinants within the Surface Proteins Involved in the Pathogenicity of H5N1 Influenza Viruses in Chickens  

Microsoft Academic Search

Although it is established that the cleavage site and glycosylation patterns in the hemagglutinin (HA) play important roles in determining the pathogenicity of H5 avian influenza viruses, some viruses exist that are not highly pathogenic despite possessing the known characteristics of high pathogenicity (i.e., their HA contains multiple basic amino acids at the cleavage site and has glycosylation patterns similar

Diane J. Hulse; Robert G. Webster; Rupert J. Russell; Daniel R. Perez

2004-01-01

216

A Randomised Controlled Trial to Determine the Effectiveness of an Early Psychological Intervention with Children Involved in Road Traffic Accidents  

ERIC Educational Resources Information Center

Objective: To determine whether an early intervention using a psychological debriefing format is effective in preventing psychological distress in child road traffic accident survivors. Design: Randomised controlled trial. Setting: Accident and Emergency Department, Royal United Hospital, Bath. Subjects: 158 children aged 7-18. Follow-up…

Stallard, Paul; Velleman, Richard; Salter, Emma; Howse, Imogen; Yule, William; Taylor, Gordon

2006-01-01

217

Economic evaluation of inactive uranium mill tailings, Tuba City Site, Tuba City, Arizona  

Microsoft Academic Search

Mountain States Research and Development was contracted on March 1, 1981 to make an economic evaluation study at each of 12 abandoned uranium mill tailings sites in the western states. The objective of this work was to obtain the data necessary at each site to determine the possible revenue that could be derived from reprocessing the tailings. To accomplish this

Teel

1982-01-01

218

PARTICLE TRAJECTORIES IN MODEL CURRENT SHEETS. 2. APPLICATIONS TO AURORAS USING A GEOMAGNETIC TAIL MODEL  

Microsoft Academic Search

Individual particle trajectories are determined analytically and numerically in two possible configurations of electric and magnetic fields in the geomagnetic tail. The models are based on reconnection models incorporating a neutral point with associated neutral or current sheet and on the observed neutral sheet in the geomagnetic tail. Both models contain magnetic field lines oppositely directed on either side of

T. W. Speiser

1967-01-01

219

Field and modeling study of windblown particles from a uranium mill tailings pile  

Microsoft Academic Search

An extensive field study whose primary objective was to obtain knowledge and understanding of the nature and quantity of windblown particles from uranium mill tailings piles was conducted in the Ambrosia Lake District of New Mexico. The following major field tasks were undertaken: determination of physical, chemical, and radioactivity characteristics of mill tailings particles; an investigation of the nature and

L. C. Schwendiman; G. A. Sehmel; T. W. Horst; C. W. Thomas; R. W. Perkins

1980-01-01

220

Groundwater leaching of neutralized and untreated acid-leached uranium-mill tailings  

Microsoft Academic Search

Tailings neutralization was examined to determine the effect of neutralization on contaminant release. Column leaching of acid extracted uranium mill tailings from Exxon Highland Mill, Wyoming, Pathfinder Gas Hills Mill, Wyoming, and the Dawn Midnite Mill, Washington, resulted in the flushing of high concentrations of salts in the first four pore volumes of leachate, followed by a steady decrease to

G. W. Gee; C. W. Begej; A. C. Campbell; N. N. Sauter; B. E. Opitz; D. R. Sherwood

1981-01-01

221

Environmental Isotopes as a Useful Tool for Studies at Mixed Uranium Mill Tailings Sites  

Microsoft Academic Search

Groundwaters in the area of a mixed landfill (domestic waste above uranium mill tailings) in Dresden (Saxony, Germany) were investigated for their isotope signatures to distinguish between different groundwater types. To determine between the two contamination sources (waste and uranium mill tailings) a multi parameter interpretation was done using both, the main hydrochemical parameters the radionuclides U, U, Ra and

C. Helling

2000-01-01

222

Uranium mill tailings quarterly report, January-March 1982  

Microsoft Academic Search

Progress is reported on: radon barrier systems for uranium mill tailings; liner evaluation for uranium mill tailings; revegetation\\/rock cover for stabilization of inactive U-tailings sites; and application of long-term chemical biobarriers for uranium tailings.

Latkovich

1982-01-01

223

Slow inward tail currents in rabbit cardiac cells.  

PubMed Central

1. A whole-cell gigaseal suction microelectrode voltage-clamp technique has been used to study slow inward tail currents in single myocytes obtained by enzymatic dispersion of rabbit ventricle and atrium. A variety of stimulation protocols, Tyrode solutions and pharmacological agents have been used to test three hypotheses: (a) that the slow inward tail current is generated by an electrogenic Na(+)-Ca2+ exchanger; (b) that a rise in [Ca2+]i, due to release from the sarcoplasmic reticulum can modulate the activity of this exchanger; and (c) that the uptake of calcium by the sarcoplasmic reticulum is a major determinant of the time course of the tail current. 2. As shown previously in amphibian atrium and guinea-pig ventricle, slow inward tail currents can be observed consistently under conditions in which action potentials and ionic currents are recorded using microelectrode constituents which only minimally disturb the intracellular milieu. 3. In ventricular cells, the envelope of these tail currents obtained by varying the duration of the preceding depolarizations shows that (a) the tail currents are activated by pulses as short as 10 ms, and reach a maximum for pulse durations of 100-200 ms, (b) the rate of decay of the tail current gradually increases as the activating depolarizations are prolonged, and (c) the tails cannot be due to deactivation of calcium currents, in agreement with other studies in frog heart. 4. When the mean level of [Ca2+]i is raised following inhibition of the Na(+)-K+ pump by strophanthidin (10(-5) M) or reductions in [K+]o (0.5 mM), the slow inward tail grows in size prior to the onset of a contracture or other signs of calcium-induced toxicity. 5. In a number of different preparations, replacement of [Ca2+]o with BaCl2 markedly or completely inhibits the Na(+)-Ca2+ exchanger, whereas Sr2+ replacement does not have this effect. In myocytes from rabbit ventricle the slow inward tails are reduced significantly and decay more slowly in 0.5-2.2 mM-BaCl2 Tyrode solution, while in 2.2 mM SrCl2 these tails are not altered. 6. The slow inward tail also shows a dependence on [K+]o, corresponding to previous data on Na(+)-Ca2+ exchange in other tissues. Increasing [K+]o in the Tyrode solution to a final concentration of 10-15 mM results in a marked inhibition of the slow tails. This effect cannot be accounted for by changes in the inwardly rectifying potassium current, IK1. 7. The slow tail currents were changed significantly by increasing the temperature of the superfusing Tyrode solution.(ABSTRACT TRUNCATED AT 400 WORDS)

Giles, W; Shimoni, Y

1989-01-01

224

Ratios of bottom meson branching fractions involving J\\/psi mesons and determination of b quark fragmentation fractions  

Microsoft Academic Search

We report a measurement of the ratios of the decay rates of the B+, B0, and B0s mesons into exclusive final states containing a J\\/psi meson. The final states were selected from 19.6 pb-1 of pp¯ collisions recorded by the Collider Detector at Fermilab. These data are interpreted to determine the b quark fragmentation fractions fu, fd, and fs. We

F. Abe; H. Akimoto; A. Akopian; M. G. Albrow; S. R. Amendolia; D. Amidei; J. Antos; C. Anway-Wiese; S. Aota; G. Apollinari; T. Asakawa; W. Ashmanskas; M. Atac; F. Azfar; P. Azzi-Bacchetta; N. Bacchetta; W. Badgett; S. Bagdasarov; M. W. Bailey; J. Bao; P. de Barbaro; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; E. Barzi; G. Bauer; T. Baumann; F. Bedeschi; S. Behrends; S. Belforte; G. Bellettini; J. Bellinger; D. Benjamin; J. Benlloch; J. Bensinger; D. Benton; A. Beretvas; J. P. Berge; J. Berryhill; S. Bertolucci; B. Bevensee; A. Bhatti; K. Biery; M. Binkley; D. Bisello; R. E. Blair; C. Blocker; A. Bodek; W. Bokhari; G. Bolla; V. Bolognesi; D. Bortoletto; J. Boudreau; L. Breccia; C. Bromberg; N. Bruner; E. Buckley-Geer; H. S. Budd; K. Burkett; G. Busetto; A. Byon-Wagner; K. L. Byrum; J. Cammerata; C. Campagnari; M. Campbell; A. Caner; W. Carithers; D. Carlsmith; A. Castro; D. Cauz; Y. Cen; F. Cervelli; P. S. Chang; H. Y. Chao; J. Chapman; M.-T. Cheng; G. Chiarelli; T. Chikamatsu; C. N. Chiou; L. Christofek; S. Cihangir; A. G. Clark; M. Cobal; M. Contreras; J. Conway; J. Cooper; M. Cordelli; C. Couyoumtzelis; D. Crane; D. Cronin-Hennessy; R. Culbertson; J. D. Cunningham; T. Daniels; F. Dejongh; S. Delchamps; S. dell'agnello; M. dell'orso; R. Demina; L. Demortier; B. Denby; M. Deninno; P. F. Derwent; T. Devlin; J. R. Dittmann; S. Donati; J. Done; T. Dorigo; A. Dunn; N. Eddy; K. Einsweiler; J. E. Elias; R. Ely; E. Engels; D. Errede; S. Errede; Q. Fan; I. Fiori; B. Flaugher; G. W. Foster; M. Franklin; M. Frautschi; J. Freeman; J. Friedman; T. A. Fuess; Y. Fukui; S. Funaki; G. Gagliardi; S. Galeotti; M. Gallinaro; M. Garcia-Sciveres; A. F. Garfinkel; C. Gay; S. Geer; D. W. Gerdes; P. Giannetti; N. Giokaris; P. Giromini; L. Gladney; D. Glenzinski; M. Gold; J. Gonzalez; A. Gordon; A. T. Goshaw; K. Goulianos; H. Grassmann; L. Groer; C. Grosso-Pilcher; G. Guillian; R. S. Guo; C. Haber; E. Hafen; S. R. Hahn; R. Handler; R. M. Hans; K. Hara; A. D. Hardman; B. Harral; R. M. Harris; S. A. Hauger; J. Hauser; C. Hawk; E. Hayashi; J. Heinrich; K. D. Hoffman; M. Hohlmann; C. Holck; R. Hollebeek; L. Holloway; A. Hölscher; S. Hong; G. Houk; P. Hu; B. T. Huffman; R. Hughes; J. Huston; J. Huth; J. Hylen; H. Ikeda; M. Incagli; J. Incandela; G. Introzzi; J. Iwai; Y. Iwata; H. Jensen; U. Joshi; R. W. Kadel; E. Kajfasz; H. Kambara; T. Kamon; T. Kaneko; K. Karr; H. Kasha; Y. Kato; T. A. Keaffaber; L. Keeble; K. Kelley; R. D. Kennedy; R. Kephart; P. Kesten; D. Kestenbaum; R. M. Keup; H. Keutelian; F. Keyvan; B. Kharadia; B. J. Kim; D. H. Kim; H. S. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; L. Kirsch; P. Koehn; K. Kondo; J. Konigsberg; S. Kopp; K. Kordas; A. Korytov; W. Koska; E. Kovacs; W. Kowald; M. Krasberg; J. Kroll; M. Kruse; T. Kuwabara; S. E. Kuhlmann; E. Kuns; A. T. Laasanen; N. Labanca; S. Lammel; J. I. Lamoureux; T. Lecompte; S. Leone; J. D. Lewis; P. Limon; M. Lindgren; T. M. Liss; N. Lockyer; O. Long; C. Loomis; M. Loreti; J. Lu; D. Lucchesi; P. Lukens; S. Lusin; J. Lys; K. Maeshima; A. Maghakian; P. Maksimovic; M. Mangano; J. Mansour; M. Mariotti; J. P. Marriner; A. Martin; J. A. Matthews; R. Mattingly; P. McIntyre; P. Melese; A. Menzione; E. Meschi; S. Metzler; C. Miao; T. Miao; G. Michail; R. Miller; H. Minato; S. Miscetti; M. Mishina; H. Mitsushio; T. Miyamoto; S. Miyashita; N. Moggi; Y. Morita; J. Mueller; A. Mukherjee; T. Muller; P. Murat; H. Nakada; I. Nakano; C. Nelson; D. Neuberger; C. Newman-Holmes; M. Ninomiya; L. Nodulman; S. H. Oh; K. E. Ohl; T. Ohmoto; T. Ohsugi; R. Oishi; M. Okabe; T. Okusawa; R. Oliveira; J. Olsen; C. Pagliarone; R. Paoletti; V. Papadimitriou; S. P. Pappas; A. Parri; J. Patrick; G. Pauletta; M. Paulini; A. Perazzo; L. Pescara; M. D. Peters; T. J. Phillips; G. Piacentino; M. Pillai; K. T. Pitts; R. Plunkett; L. Pondrom; J. Proudfoot; F. Ptohos; G. Punzi; K. Ragan; A. Ribon; F. Rimondi; L. Ristori; W. J. Robertson; T. Rodrigo; S. Rolli; J. Romano; L. Rosenson; R. Roser; W. K. Sakumoto; D. Saltzberg; A. Sansoni; L. Santi; H. Sato; V. Scarpine; P. Schlabach; E. E. Schmidt; M. P. Schmidt; A. Scribano; S. Segler; S. Seidel; Y. Seiya; G. Sganos; M. D. Shapiro; N. M. Shaw; Q. Shen; P. F. Shepard; M. Shimojima; M. Shochet; J. Siegrist; A. Sill; P. Sinervo; P. Singh; J. Skarha; K. Sliwa; F. D. Snider; T. Song; J. Spalding; T. Speer; P. Sphicas; F. Spinella; M. Spiropulu; L. Spiegel; L. Stanco; J. Steele; A. Stefanini; K. Strahl; J. Strait; R. Ströhmer; D. Stuart; G. Sullivan; A. Soumarokov; K. Sumorok; J. Suzuki; T. Takada; T. Takahashi; T. Takano; K. Takikawa; N. Tamura; F. Tartarelli; W. Taylor; P. K. Teng; Y. Teramoto; S. Tether; D. Theriot; T. L. Thomas; R. Thun; M. Timko; P. Tipton; A. Titov; S. Tkaczyk; D. Toback; K. Tollefson; A. Tollestrup; J. Tonnison; J. F. de Troconiz; S. Truitt; J. Tseng; N. Turini; T. Uchida; N. Uemura; F. Ukegawa; G. Unal; J. Valls; S. C. van den Brink; S. Vejcik

1996-01-01

225

Extracting aluminum from dross tailings  

NASA Astrophysics Data System (ADS)

Aluminum dross tailings, an industrial waste, from the Egyptian Aluminium Company (Egyptalum) was used to produce two types of alums: aluminum-sulfate alum [itAl2(SO4)3.12H2O] and ammonium-aluminum alum [ (NH 4)2SO4AL2(SO4)3.24H2O]. This was carried out in two processes. The first process is leaching the impurities using diluted H2SO4 with different solid/liquid ratios at different temperatures to dissolve the impurities present in the starting material in the form of solute sulfates. The second process is the extraction of aluminum (as aluminum sulfate) from the purifi ed aluminum dross tailings thus produced. The effects of temperature, time of reaction, and acid concentration on leaching and extraction processes were studied. The product alums were analyzed using x-ray diffraction and thermal analysis techniques.

Amer, A. M.

2002-11-01

226

Cultural Resource Survey at Orwell Reservoir, Otter Tail County, Minnesota,  

National Technical Information Service (NTIS)

The purpose of this report is to present the methods and results of an archaeological survey at Orwell Lake, Otter Tail county, Minnesota. The survey was done to determine the presence or absence of any cultural material at specified areas of the reservoi...

R. A. Strachan K. A. Roetzel

1986-01-01

227

Prediction of sedimentation and consolidation of fine tails  

Microsoft Academic Search

Sedimentation and consolidation of suspensions of fine particles were analyzed by integrating experimental measurement of properties in a centrifuge with a comprehensive numerical model. The yield stress and settling velocity for tailings from tar sands extraction were determined experimentally as a function of the volume fraction of solids. The evaluated state functions were used to simulate batch settling and consolidation,

William F. Eckert; Jacob H. Masliyah; Murray R. Gray; Phillip M. Fedorak

1996-01-01

228

An evaluation procedure for flocculation of coal preparation plant tailings  

Microsoft Academic Search

In solid–liquid separation of coal preparation plant tailings by flocculation, in addition to the type and amount of flocculants, the composition of waste materials including clay minerals must be determined in order to devise an effective and economic sedimentation system. In this study, the characterization of organic and inorganic impurities was made with the help of mineralogical data and instrumental

E. Sabah; I. Cengiz

2004-01-01

229

HIV-1 Nef Responsiveness is Determined by Env Variable Regions Involved in Trimer Association and Correlates with Neutralization Sensitivity  

PubMed Central

SUMMARY HIV-1 Nef and the unrelated MLV glycoGag similarly enhance the infectivity of HIV-1 virions. We now show that the effects of Nef and glycoGag are similarly determined by variable regions of HIV-1 gp120 that control Env trimer association and neutralization sensitivity. Whereas neutralization-sensitive X4-tropic Env proteins conferred high responsiveness to Nef and glycoGag, particles bearing neutralization-resistant R5-tropic Envs were considerably less affected. The profoundly different Nef/glycoGag-responsiveness of a neutralization-resistant and a neutralization-sensitive R5-tropic Env could be switched by exchanging their gp120 V1/V2 regions, which also switches their neutralization sensitivity. Within V1/V2, the same determinants governed Nef/glycoGag-responsiveness and neutralization sensitivity, indicating that these phenotypes are mechanistically linked. The V1/V2 and V3 regions, which form an apical trimer-association domain, together determined the Nef- and glycoGag-responsiveness of an X4-tropic Env. Our results suggest that Nef and glycoGag counteract the inactivation of Env spikes with relatively unstable apical trimer-association domains.

Usami, Yoshiko; Gottlinger, Heinrich

2013-01-01

230

Bearing capacity of desiccated tailings  

Microsoft Academic Search

The development of matric suctions in soils contributes to their shear strength, resulting in an enhanced factor of safety against bearing-capacity failure. In this paper, matric suction profiles of desiccated mine tailings are predicted from a steady-state solution for evaporative conditions, and from an isothermal mathematical model that simulates liquid and vapor water flow through soils. The shear-strength envelope with

Daud W. Rassam; David J. Williams

1999-01-01

231

Tadpole tail regeneration in Xenopus.  

PubMed

Some organisms have a remarkable ability to heal wounds without scars and to regenerate complex tissues following injury. By gaining a more complete understanding of the biological mechanisms that promote scar-free healing and tissue regeneration, it is hoped that novel treatments that can enhance the healing and regenerative capacity of human patients can be found. In the present article, we briefly examine the genetic, molecular and cellular mechanisms underlying the regeneration of the Xenopus tadpole tail. PMID:24849228

Chen, Yaoyao; Love, Nick R; Amaya, Enrique

2014-06-01

232

Curved tails in polymerization-based bacterial motility  

NASA Astrophysics Data System (ADS)

The curved actin ``comet-tail'' of the bacterium Listeria monocytogenes is a visually striking signature of actin polymerization-based motility. Similar actin tails are associated with Shigella flexneri, spotted-fever Rickettsiae, the Vaccinia virus, and vesicles and microspheres in related in vitro systems. We show that the torque required to produce the curvature in the tail can arise from randomly placed actin filaments pushing the bacterium or particle. We find that the curvature magnitude determines the number of actively pushing filaments, independent of viscosity and of the molecular details of force generation. The variation of the curvature with time can be used to infer the dynamics of actin filaments at the bacterial surface.

Rutenberg, Andrew D.; Grant, Martin

2001-08-01

233

[Leaching kinetics of josephinite tailings with sulfuric acid].  

PubMed

Leaching is the most important step of josephinite tailing recycle technology. This step can separate the valuable metal Mg from Si and other impure metal. Effects of sulfuric acid on leaching Mg efficiency from josephinite tailings were investigated. To obtain the leaching behavior, a modified unreacted shrinking core model that based on the experimental data was used to determine the dissolution kinetic parameters. The model was significant and showed that the dissolution of Mg2+ in josephinite tailing was controlled by the produce layer diffusion, apparent activation reaction energy E = 34.04 kJ x mol(-1). The produce layers obstruct the forward reaction of the dissolution of Mg2+. PMID:24028005

Chen, An-An; Zhou, Shao-Qi; Huang, Peng-Fei

2013-07-01

234

A Direct Determination of the Fractionation Factors Involved in the Making and Breaking of S-O Bonds in Sulfates  

NASA Astrophysics Data System (ADS)

Although the bacterially assisted reduction reaction of sulfate to sulfide in the geo- and biological environment is of immense importance and the accompanying S-isotope fractionation has been the subject of several major studies, the reaction pathway is not known with any degree of certainty. Methylsulfuric acid, CH3HSO4 is an ideal model compound for the investigation of this reaction pathway. The reaction is acid catalysed and proceeds via a three step sequence of reactions. The first step is a protonation of the ether oxygen. The second step is the rate-determining step and takes place by a unimolecular scission of the S-O bond to form SO3 and methanol. The third step is the reaction of water with SO3 to form sulfuric acid. At 100 °C the reaction obeys first order kinetics for at least 80 % of reaction. As the reaction proceeds, measurement at regular time intervals of ?34S values of the unreacted ester and product sulfate will allow a direct determination of the kinetic isotope effect for the breaking of a single S-O bond of a sulfate moiety. The ?18O fractionation factor for the S-O bond- breaking reactions of the sulfate species can be directly determined from a knowledge of the ?18O values of the initial ester, the product sulfate and the residual unreacted ester. The ?18O value of the product sulfate will also reflect the oxygen isotopic abundance of the H2O solvent system. If the reaction is studied in a range of waters with differing ?18O values a measure of the kinetic isotope effect for the making of a S-O bond in going from SO3 to H2SO4 can be determined. If the Rayleigh Equation is applied to the experimental data currently on hand, the value of ? the fractionation factor for the breaking of a single S-O bond is found to be 1.0132±0.0009, a value appreciably less than the microbiologically assisted reaction observed in nature for the reduction of sulfate to sulfide but explicable in terms of the reaction model proposed by Rees in 1973. The oxygen data are relevant to the proposed reoxidation of sulfite to sulfate mechanism invoked in some studies to explain the observed high sulfate ?18O values.

Krouse, R.; Batts, B.

2006-12-01

235

Bilateral vagotomy as a tool for determining autonomic involvement in airway responses in mouse models of asthma.  

PubMed

This chapter describes the use of bilateral vagotomy as a tool for determining autonomic regulation of airway responses to the exogenous bronchoconstrictor thromboxane mimetic U46619 in an acute model of asthma in the mouse. Mice receive a sensitization of ovalbumin (OVA) and adjuvant followed by 3 days of OVA aerosol to induce allergic airway disease characterized by bronchoalveolar lavage (BAL) eosinophilia, increased mucus production, and elevated IgE and IL-13. Using a small animal ventilator (Flexi-vent) and the forced oscillatory technique fit to the constant phase model of the lung, a variety of features associated with human asthma can be evaluated in mouse models. For example, this protocol describes the methods to evaluate central and peripheral airway mechanics, airway resistance (R aw) and tissue damping (G), and tissue elastance (H) in response to U46619. The contribution of autonomic nerves in this response is determined by severing both the left and right vagus nerves prior to aerosol challenge. PMID:23943456

Cyphert, Jaime M

2013-01-01

236

Chapter 17 Placing soil covers on soft mine tailings  

Microsoft Academic Search

Mine tailings are typically silt-sized materials derived from mineral processing, which are conventionally pumped as an aqueous slurry, thickened tailings or tailings paste to a tailings storage facility, usually a surface impoundment. On discharge, an aqueous tailings slurry forms a delta, on which the tailings particles undergo hydraulic sorting, sedimentation and self-weight consolidation, and desiccation on exposure to evaporation. Their

David John Williams

2005-01-01

237

The Crystal Structure of Bacteriophage HK97 gp6: Defining a Large Family of Head?Tail Connector Proteins  

SciTech Connect

The final step in the morphogenesis of long-tailed double-stranded DNA bacteriophages is the joining of the DNA-filled head to the tail. The connector is a specialized structure of the head that serves as the interface for tail attachment and the point of egress for DNA from the head during infection. Here, we report the determination of a 2.1 {angstrom} crystal structure of gp6 of bacteriophage HK97. Through structural comparisons, functional studies, and bioinformatic analysis, gp6 has been determined to be a component of the connector of phage HK97 that is evolutionarily related to gp15, a well-characterized connector component of bacteriophage SPP1. Whereas the structure of gp15 was solved in a monomeric form, gp6 crystallized as an oligomeric ring with the dimensions expected for a connector protein. Although this ring is composed of 13 subunits, which does not match the symmetry of the connector within the phage, sequence conservation and modeling of this structure into the cryo-electron microscopy density of the SPP1 connector indicate that this oligomeric structure represents the arrangement of gp6 subunits within the mature phage particle. Through sequence searches and genomic position analysis, we determined that gp6 is a member of a large family of connector proteins that are present in long-tailed phages. We have also identified gp7 of HK97 as a homologue of gp16 of phage SPP1, which is the second component of the connector of this phage. These proteins are members of another large protein family involved in connector assembly.

Cardarelli, Lia; Lam, Robert; Tuite, Ashleigh; Baker, Lindsay A.; Sadowski, Paul D.; Radford, Devon R.; Rubinstein, John L.; Battaile, Kevin P.; Chirgadze, Nickolay; Maxwell, Karen L.; Davidson, Alan R. (UHN); (Toronto); (Hauptman)

2010-08-17

238

Spatial Coordination of Kindlin-2 with Talin Head Domain in Interaction with Integrin ? Cytoplasmic Tails*  

PubMed Central

Both talin head domain and kindlin-2 interact with integrin ? cytoplasmic tails, and they function in concert to induce integrin activation. Binding of talin head domain to ? cytoplasmic tails has been characterized extensively, but information on the interaction of kindin-2 with this integrin segment is limited. In this study, we systematically examine the interactions of kindlin-2 with integrin ? tails. Kindlin-2 interacted well with ?1 and ?3 tails but poorly with the ?2 cytoplasmic tail. This binding selectivity was determined by the non-conserved residues, primarily the three amino acids at the extreme C terminus of the ?3 tail, and the sequence in ?2 was non-permissive. The region at the C termini of integrin ?1 and ?3 tails recognized by kindlin-2 was a binding core of 12 amino acids. Kindlin-2 and talin head do not interact with one another but can bind simultaneously to the integrin ?3 tail without enhancing or inhibiting the interaction of the other binding partner. Kindlin-2 itself failed to directly unclasp integrin ?/? tail complex, indicating that kindlin-2 must cooperate with talin to support the integrin activation mechanism.

Bledzka, Kamila; Liu, Jianmin; Xu, Zhen; Perera, H. Dhanuja; Yadav, Satya P.; Bialkowska, Katarzyna; Qin, Jun; Ma, Yan-Qing; Plow, Edward F.

2012-01-01

239

The Principal Genetic Determinants for Nasopharyngeal Carcinoma in China Involve the HLA Class I Antigen Recognition Groove  

PubMed Central

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy facilitated by Epstein-Barr Virus infection. Here we resolve the major genetic influences for NPC incidence using a genome-wide association study (GWAS), independent cohort replication, and high-resolution molecular HLA class I gene typing including 4,055 study participants from the Guangxi Zhuang Autonomous Region and Guangdong province of southern China. We detect and replicate strong association signals involving SNPs, HLA alleles, and amino acid (aa) variants across the major histocompatibility complex-HLA-A, HLA –B, and HLA -C class I genes (PHLA-A-aa-site-62?=?7.4×10?29; P HLA-B-aa-site-116?=?6.5×10?19; P HLA-C-aa-site-156?=?6.8×10?8 respectively). Over 250 NPC-HLA associated variants within HLA were analyzed in concert to resolve separate and largely independent HLA-A, -B, and -C gene influences. Multivariate logistical regression analysis collapsed significant associations in adjacent genes spanning 500 kb (OR2H1, GABBR1, HLA-F, and HCG9) as proxies for peptide binding motifs carried by HLA- A*11:01. A similar analysis resolved an independent association signal driven by HLA-B*13:01, B*38:02, and B*55:02 alleles together. NPC resistance alleles carrying the strongly associated amino acid variants implicate specific class I peptide recognition motifs in HLA-A and -B peptide binding groove as conferring strong genetic influence on the development of NPC in China.

Tang, Minzhong; Lautenberger, James A.; Gao, Xiaojiang; Sezgin, Efe; Hendrickson, Sher L.; Troyer, Jennifer L.; David, Victor A.; Guan, Li; Mcintosh, Carl E.; Guo, Xiuchan; Zheng, Yuming; Liao, Jian; Deng, Hong; Malasky, Michael; Kessing, Bailey; Winkler, Cheryl A.; Carrington, Mary; de The, Guy; Zeng, Yi; O'Brien, Stephen J.

2012-01-01

240

The hydrogeology of a tailings impoundment formed by central discharge of thickened tailings: implications for tailings management  

NASA Astrophysics Data System (ADS)

The Kidd Creek Cu-Zn sulfide mine is located near Timmins, Ontario. Mill tailings are thickened and deposited as a slurry in a circular impoundment with an area of approximately 1200 ha. Deposition of tailings as a thickened slurry from a central discharge ramp results in a conical-shaped tailings deposit with low perimeter dykes, a uniform grain-size distribution, uniform and low hydraulic conductivity, and a tension-saturated zone above the water table up to 5 to 6 m thick. These characteristics provide benefits over conventionally disposed tailings with respect to tailings management. The thick tension-saturated zone within the tailings limits the thickness of unsaturated tailings that are susceptible to rapid sulfide oxidation. The conical shape of the deposit results in the formation of a recharge area near the centre of the impoundment and discharge in the peripheral areas. In contrast, the elevated nature of many conventional, unthickened tailings impoundments results in recharge over most of the surface of the impoundment, with discharge occurring outside the impoundment through large containment dykes. Three-dimensional pore water flow modelling suggests that approximately 90% of the total discharge from the thickened tailings occurs within the tailings impoundment. When discharge is confined within the impoundment, there is improved control over low-quality effluent, and an opportunity to design passive control measures to reduce treatment costs and minimize environmental impacts.

Al, Tom A.; Blowes, David W.

1999-06-01

241

Long-Term Performance of Uranium Tailings Disposal Cells - 13340  

SciTech Connect

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{sup -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 hydraulic conductivity after transient drainage, eventually the amount of moisture leaving the tailings has a negligible effect on groundwater quality. Although some of the UMTRA sites are not in compliance with the groundwater standards, the explanation may be legacy contamination from mining, or earlier higher fluxes from the tailings or unlined processing ponds. Investigation of other legacy sources at the UMTRA sites may help explain persistent groundwater contamination. (authors)

Bostick, Kent; Daniel, Anamary; Pill, Ken [Professional Project Services, Inc., 1100 Bethel Valley Road, Oak Ridge, TN, 37922 (United States)] [Professional Project Services, Inc., 1100 Bethel Valley Road, Oak Ridge, TN, 37922 (United States); Tachiev, Georgio; Noosai, Nantaporn; Villamizar, Viviana [Florida International University, 10555 W. Flagler St., EC 2100, Miami FL, 33174 (United States)] [Florida International University, 10555 W. Flagler St., EC 2100, Miami FL, 33174 (United States)

2013-07-01

242

Evidence for a pathogenic determinant in HIV-1 Nef involved in B cell dysfunction in HIV/AIDS  

PubMed Central

SUMMARY B lymphocyte hyperactivation and hypergammaglobulinemia are pathogenic manifestations of HIV-1 infection. Here we provide evidence that these B cell defects are driven by factors produced by HIV-1 infected macrophages and that Nef is necessary for this activity. In vitro, HIV-1 infected macrophages or macrophages expressing Nef promoted B cell activation and differentiation to immunoglobulin-secreting cells. Activation of NF-?B by Nef induced secretion of the acute-phase reactant ferritin and ferritin was necessary and sufficient for these B cell effects. The extent of hypergammaglobulinemia in HIV-1 infected individuals correlated directly with plasma ferritin levels and with viral load. We further demonstrate that induction of ferritin and hypergammaglobulinemia could be recapitulated when Nef was specifically expressed in macrophages and T cells of transgenic mice. Collectively, these results reveal the presence of a pathogenic determinant within the Nef protein of HIV-1 which governs B cell defects in HIV-1 infection.

Swingler, Simon; Zhou, Jin; Swingler, Catherine; Dauphin, Ann; Greenough, Thomas; Jolicoeur, Paul; Stevenson, Mario

2010-01-01

243

Determinants involved in subtype-specific functions of rat trace amine-associated receptors 1 and 4  

PubMed Central

Aims The trace amine-associated receptor (Taar) family displays high species- and subtype-specific pharmacology. Several trace amines such as ?-phenylethylamine (?-PEA), p-tyramine and tryptamine are agonists at TA1 but poorly activate rat and mouse Taar4. Principal Results Using rat TA1 and Taar4 chimera, we identified determinants in transmembrane helices 3 and 6, which, when replaced by the corresponding portion of rat TA1, can rescue cell surface expression of rat Taar4. When expressed at the cell surface, rat Taar4 pharmacology was very similar to that of TA1 and coupled to the G?s-protein/AC pathway. Our data suggest that binding pockets of Taar for surrogate agonists overlap between paralogs. Conclusions This implicates that the repertoire of Taar ensures functional redundancy, tissue- and cell-specific expression and/or different downstream signalling rather than different agonist specificity.

Staubert, C; Bohnekamp, J; Schoneberg, T

2013-01-01

244

Effects of tail span and empennage arrangement on drag of a typical single-engine fighter aft end  

NASA Technical Reports Server (NTRS)

An investigation was conducted in the Langley 16 foot Transonic Tunnel to determine the effects of tail span and empennage arrangement on drag of a single engine nozzle/afterbody model. Tests were conducted at Mach numbers from 0.50 to 1.20, nozzle pressures frm 1.0 (jet off) to 8.0, and angles of attack from -3 to 9 deg, depending upon Mach numbers. Three empennage arrangements (aft, staggered, and forward) were investigated with several different tail spans. The results of the investigation indicate that tail span and position have a significant effect on the drag at transonic speeds. Unfavorable tail interference was largely due to the outer portion of the tail surfaces. The inner portion near the nozzle and afterbody did little to increase drag other than surface skin friction. Tail positions forward of the nozzle generally had lower tail interference.

Burley, J. R., II; Berrier, B. L.

1984-01-01

245

Analytical methods involving separation techniques for determination of low-molecular-weight biothiols in human plasma and blood.  

PubMed

Low-molecular-weight biothiols such as homocysteine, cysteine, and glutathione are metabolites of the sulfur cycle and play important roles in biological processes such as the antioxidant defense network, methionine cycle, and protein synthesis. Thiol concentrations in human plasma and blood are related to diseases such as cardiovascular disease, neurodegenerative disease, and cancer. The concentrations of homocysteine, cysteine, and glutathione in plasma samples from healthy human subjects are approximately in the range of 5-15, 200-300, and 1-5?M, respectively. Glutathione concentration in the whole blood is in the millimolar range. Measurement of biothiol levels in plasma and blood is thought to be important for understanding the physiological roles and biomarkers for certain diseases. This review summarizes the relationship of biothiols with certain disease as well as pre-analytical treatment and analytical methods for determination of biothiols in human plasma and blood by using high-performance liquid chromatography and capillary electrophoresis coupled with ultraviolet, fluorescence, or chemiluminescence detection; or mass spectrometry. PMID:24556466

Isokawa, Muneki; Kanamori, Takahiro; Funatsu, Takashi; Tsunoda, Makoto

2014-08-01

246

Enhancing the safety of tailings management facilities  

SciTech Connect

Unsafe tailings management facilities (TMFs) have caused serious accidents in Europe threatening human health/life and the environment. While advanced design, construction and management procedures are available, their implementation requires greater emphasis. An integrated research project funded by the European Union was carried out between 2002 and 2005 with the overall goal of improving the safety of TMFs (Sustainable Improvement in Safety of Tailings Facilities - TAILSAFE, http://www.tailsafe.com/). The objective of TAILSAFE was to develop and apply methods of parameter evaluation and measurement for the assessment and improvement of the safety state of tailings facilities, with particular attention to the stability of tailings dams and slurries, the special risks inherent when such materials include toxic or hazardous wastes, and authorization and management procedures for tailings facilities. Aspects of tailings facilities design, water management and slurry transport, non-destructive and minimally intrusive testing methods, monitoring and the application of sensors, intervention and remediation options were considered in TAILSAFE. A risk reduction framework (the TAILSAFE Parameter Framework) was established to contribute to the avoidance of catastrophic accidents and hazards from tailings facilities. Tailings from the mining and primary processing of metals, minerals and coal were included within the scope of TAILSAFE. The project focused on the avoidance of hazards by developing procedures and methods for investigating and improving the stability of tailings dams and tailings bodies.

Meggyes, T.; Niederleithinger, E.; Witt, K.J.; Csovari, M.; Kreft-Burman, K.; Engels, J.; McDonald, C.; Roehl, K.E. [BAM, Berlin (Germany). Federal Institute for Material Research & Testing

2008-07-01

247

Identification of three critical acidic residues of poly(ADP-ribose) glycohydrolase involved in catalysis: determining the PARG catalytic domain  

PubMed Central

PARG [poly(ADP-ribose) glycohydrolase] catalyses the hydrolysis of ?(1??2?) or ?(1??2?) O-glycosidic linkages of ADP-ribose polymers to produce free ADP-ribose. We investigated possible mechanistic similarities between PARG and glycosidases, which also cleave O-glycosidic linkages. Glycosidases typically utilize two acidic residues for catalysis, thus we targeted acidic residues within a conserved region of bovine PARG that has been shown to contain an inhibitor-binding site. The targeted glutamate and aspartate residues were changed to asparagine in order to minimize structural alterations. Mutants were purified and assayed for catalytic activity, as well as binding, to an immobilized PARG inhibitor to determine ability to recognize substrate. Our investigation revealed residues essential for PARG catalytic activity. Two adjacent glutamic acid residues are found in the conserved sequence Gln755-Glu-Glu757, and a third residue found in the conserved sequence Val737-Asp-Phe-Ala-Asn741. Our functional characterization of PARG residues, along with recent identification of an inhibitor-binding residue Tyr796 and a glycine-rich region Gly745-Gly-Gly747 important for PARG function, allowed us to define a PARG ‘signature sequence’ [vDFA-X3-GGg-X6–8-vQEEIRF-X3-PE-X14-E-X12-YTGYa], which we used to identify putative PARG sequences across a range of organisms. Sequence alignments, along with our mapping of PARG functional residues, suggest the presence of a conserved catalytic domain of approx. 185 residues which spans residues 610–795 in bovine PARG.

Patel, Chandra N.; Koh, David W.; Jacobson, Myron K.; Oliveira, Marcos A.

2005-01-01

248

Determination of alveolar epithelial cell phenotypes in fetal sheep: evidence for the involvement of basal lung expansion  

PubMed Central

The factors that control the differentiation of alveolar epithelial cells (AECs) into type-I and type-II cells in vivo are largely unknown. As sustained increases in fetal lung expansion induce type-II AECs to differentiate into type-I cells, our aim was to determine whether reduced fetal lung expansion can induce type-I AECs to trans-differentiate into type-II AECs. Chronically catheterised fetal sheep were divided into two age-matched control groups and three experimental groups (n = 5 for each). The experimental groups were exposed to either: (1) 10 days of increased lung expansion induced by tracheal obstruction (TO), (2) 10 days of TO followed by 5 days of reduced lung expansion induced by lung liquid drainage (LLD), or (3) 10 days of TO followed by 10 days of LLD. Following 10 days of TO, 5 days of LLD reduced the proportion of type-I AECs from 89.4 ± 0.9 % to 68.4 ± 2.8 %, which was similar to control values (64.8 ± 0.5 %), and increased the proportion of type-II AECs from 1.9 ± 0.3 % to 21.9 ± 2.8 %, which remained below control values (33.4 ± 1.7 %). The same treatment increased surfactant protein (SP)-A, SP-B and SP-C mRNA levels (expressed as a percentage of control values) from 26.7 ± 6.0 %, 40.0 ± 7.3 % and 10.3 ± 1.8 % to 78.1 ± 10.3 %, 105.8 ± 12.7 % and 121.0 ± 14.1 %, respectively. Similar results were obtained after 10 days of LLD, which followed 10 days of TO. These results indicate that the phenotypes of type-I and type-II AECs are strongly influenced by the basal degree of lung expansion in fetal sheep. Furthermore, the coincident increase in type-II AEC proportions and SP mRNA levels in response to LLD suggests that type-I AECs can trans-differentiate into functional type-II cells, and hence are not terminally differentiated.

Flecknoe, Sharon J; Wallace, Megan J; Harding, Richard; Hooper, Stuart B

2002-01-01

249

Cassini/CAPS observations of duskside tail dynamics at Saturn  

NASA Astrophysics Data System (ADS)

properties of Saturn's premidnight tail region are surveyed using Cassini/Cassini Plasma Spectrometer (CAPS) ion observations from 2010. Only low-latitude (|lat| < 6°) intervals in which the CAPS viewing was roughly symmetric inward and outward around the corotation direction are used. Our numerical moments algorithm returns nonzero ion density for 70% (999) of the intervals selected. Of these, 642 had detectable water-group ion densities, and the remainder were dominantly, if not entirely, light ions. The derived plasma parameters are similar to those found in an earlier study for the postmidnight tail region, except that we find little evidence for the systematic outflows identified in that study, and we do find numerous significant inflow events. One such inflow is identified as a dipolarization event, the first reported plasma properties of such a structure at Saturn. A second, long-lasting event may be evidence for the existence at times of a quasi-steady reconnection region in the premidnight tail. The large majority of the plasma flows are found to be within 20° of the corotation direction, though with flow speeds significantly lower than full corotation. While the inflow events represent plausible evidence for internally driven mass loss in the premidnight region, the absence of significant outflow events suggests that in the region surveyed here, tail reconnection has not yet proceeded to involve lobe field lines, so the disconnected plasma continues its general motion in the corotation direction.

Thomsen, M. F.; Wilson, R. J.; Tokar, R. L.; Reisenfeld, D. B.; Jackman, C. M.

2013-09-01

250

Heavy metal leaching from mine tailings as affected by plants  

SciTech Connect

A column experiment was conducted to determine the impact of soil cover and plants on heavy metal leaching from mine tailings and heavy metal contaminated soil. Columns made of PVC were constructed with 30 cm subsoil covered by 30 cm of mine tailings followed by 0, 30, or 60 cm subsoil covered by 30 cm of mine tailings followed by 0, 30, or 60 cm of clean topsoil. Two grasses, tall fescue (Festuca arundinacea Schreb.) and big bluestem (Andropogon gerardii), were grown in the columns. The columns were leached at a slow rate for 1 yr with a 0.001 M CaCl{sub 2} solution under unsaturated conditions. The presence of both tall fescue and big bluestem increased Zn and Cd concentrations in the leachate. Lead concentrations in leachates were not affected by the presence of plants. Although plants generally reduced the total amount of water leached, total mass of Zn and Cd leached generally was not impacted by plants. Total mass of Pb leached was positively correlated with total leachate collected from each column. Covering the mine tailings with 60 cm of topsoil increased the mass of Zn and Cd leached relative to no topsoil. When the subsoil was absent, Zn and Cd leaching increased by as much as 20-fold, verifying the ability of soil to act as a sink for metals. Mine tailing remediation by establishing vegetation can reduce Pb movement but may enhance short-term Cd and Zn leaching. However, the changes were relatively small and do not outweigh the benefits of using vegetation in mine tailings reclamation.

Zhu, D.; Schwab, A.P.; Banks, M.K.

1999-12-01

251

Mutation analysis of subjects with 46, XX sex reversal and 46, XY gonadal dysgenesis does not support the involvement of SOX3 in testis determination.  

PubMed

Despite the identification of an increasing number of genes involved in sex determination and differentiation, no cause can be attributed to most cases of 46, XY gonadal dysgenesis, approximately 20% of 46, XX males and the majority of subjects with 46, XX true hermaphroditism. Perhaps the most interesting candidate for involvement in sexual development is SOX3, which belongs to the same family of proteins (SOX) as SRY and SOX9, both of which are involved in testis differentiation. As SOX3 is the most likely evolutionary precursor to SRY, it has been proposed that it has retained a role in testis differentiation. Therefore, we screened the coding region and the 5' and 3' flanking region of the SOX3 gene for mutations by means of single-stranded conformation polymorphism and heteroduplex analysis in eight subjects with 46, XX sex reversal (SRY negative) and 25 subjects with 46, XY gonadal dysgenesis. Although no mutations were identified, a nucleotide polymorphism (1056C/T) and a unique synonymous nucleotide change (1182A/C) were detected in a subject with 46, XY gonadal dysgenesis. The single nucleotide polymorphism had a heterozygosity rate of 5.1% (in a control population) and may prove useful for future X-inactivation studies. The absence of SOX3 mutations in these patients suggests that SOX3 is not a cause of abnormal male sexual development and might not be involved in testis differentiation. PMID:11153920

Lim, H N; Berkovitz, G D; Hughes, I A; Hawkins, J R

2000-12-01

252

Chaperone Role for Proteins p618 and p892 in the Extracellular Tail Development of Acidianus Two-Tailed Virus ? †  

PubMed Central

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, is involved in this process. We propose that an additional chaperone system is required, consisting of a MoxR-type AAA ATPase (p618) and a von Willebrand domain A (VWA)-containing cochaperone, p892. Both proteins are absent from the other known bicaudavirus, STSV1, which develops a single tail intracellularly. p618 exhibits ATPase activity and forms a hexameric ring complex that closely resembles the oligomeric complex of the MoxR-like protein RavA (YieN). ATV proteins p387, p653, p800, and p892 interact with p618, and with the exception of p800, all bind to DNA. A model is proposed to rationalize the interactions observed between the different protein and DNA components and to explain their possible structural and functional roles in extracellular tail development.

Scheele, Urte; Erdmann, Susanne; Ungewickell, Ernst J.; Felisberto-Rodrigues, Catarina; Ortiz-Lombardia, Miguel; Garrett, Roger A.

2011-01-01

253

Thermal stabilization of uranium mill tailings  

Microsoft Academic Search

The treatment of uranium mill tailings by high-temperature sintering (>1050°C) has been investigated as a means of controlling the release of ²²²Rn and leachable contaminants. Thermal stabilization in laboratory trials at 1200°C reduced the radon emanation of various tailings by factors ranging from 37 to 1400 depending on the mineralogy of the tailings. The leachability of most contaminants (e.g., Al,

David R. Dreesen; Edward J. Cokal; Lawrence E. Wangen; Joel M. Williams; Edward F. Thode

1984-01-01

254

Pedological characteristics of Mn mine tailings and metal accumulation by native plants.  

PubMed

In southern China revegetation and ecological restoration of many abandoned Mn tailings has become a major concern. To determine the major constraints for plant establishment and evaluate the feasibility of remediation, a comparative study was conducted on Mn tailings and rhizosphere soils at the boundary of the tailings pond. Both tailings and rhizosphere soils had neutral to slightly alkaline pH and normal electrical conductivity. They were both enriched with organic matter (6.8-9.2%), total N (1.77-5.94 g kg(-1)), available P (41.78-73.83 mg kg(-1)) and K (146.7-906.9 mg kg(-1)), suggesting the tailings were a nutrient rich substrate for revegetation. Mn tailings were clay textured, while rhizosphere soils were silty loam or clay loam. The compaction and anoxic nature of Mn tailings were considered to be the major constraints for plant establishment. Total Mn (31903 mg kg(-1)), Cd (119 mg kg(-1)), Cu (126 mg kg(-1)) and Zn (2490 mg kg(-1)) in tailings were all at phytotoxic levels, but did not differ significantly from those in rhizosphere soils. In both tailings and rhizosphere soils, percentages of water- and DTPA-extractable metals were less than 1% and 2% of the total metal pools, respectively. Sequential extraction revealed that the majority of Mn, Cu and Zn were associated with the residual fraction, while the majority of Cd occurred as Fe-Mn oxides. The natural succession of plants around Mn tailings formed a distinctive metal-tolerant plant community, mainly comprising nine species such as Cynodon dactylon and Humulus scandens and so on. All species studied could be good candidates for revegetation of Mn tailings. PMID:18555510

Wang, Xin; Liu, Yunguo; Zeng, Guangming; Chai, Liyuan; Xiao, Xin; Song, Xiaochen; Min, Zongyi

2008-07-01

255

Recent hydrological observations from the Riverton and the Maybell tailings piles  

SciTech Connect

Field and laboratory hydrologic studies of two inactive uranium mill tailings piles are presented. The Riverton, Wyoming site is in close proximity to the water table, while the Maybell, Colorado site represents the contrasting case of the local water table being far below the tailings pile. Field studies included monitoring of hydraulic head profiles of the piles with tensiometers and piezometers, and infiltration tests. Laboratory tests on core samples from the tailings and soil cover included saturated and unsaturated hydraulic conductivity measurements, saturation versus metric heat measurements, particle-size analysis, as well as determination of bulk densities and porosities. The tensiometer data indicate that the major portion of the tailings water at both piles exists under near steady-state unsaturated conditions with flow downward towards the water table. The zero-flux surface in these regions is within a meter of the upper surface of the tailings. A case of upward flow from the aquifer through the tailings was also observed in the thinnest, eastern portion of the Riverton tailings. Combined field data and laboratory results lead to an estimated steady-state downward flow of tailings water in a typical region of the Riverton tailings in the range of 10/sup -10/ m.s/sup -1/ to 10/sup -9/ m.s/sup -1/. This is equivalent to about 3 x 10/sup -3/ m.yr/sup -1/ to 3 x 10/sup -2/ m.yr/sup -1/, a small fraction of the local mean annual precipitation (2.5 x 10/sup -1/ m.yr/sup -1/). This suggests that the bulk of the precipitation input at the Riverton tailings is lost by evaportranspiration within the upper meter of soil cover and tailings.

Tokunaga, T.; Narashimhan, T.N.

1982-09-01

256

Effects of Aerodynamic Interaction Between Main and Tail Rotors on Helicopter Hover Performance and Noise.  

National Technical Information Service (NTIS)

A model test was conducted to determine the effects of aerodynamic interaction between main rotor, tail rotor, and vertical fin on helicopter performance and noise in hover out of ground effect. The experimental data were obtained from hover tests perform...

R. P. Menger T. L. Wood J. T. Brieger

1983-01-01

257

The C-terminal unique region of desmoglein 2 inhibits its internalization via tail-tail interactions  

PubMed Central

Desmosomal cadherins, desmogleins (Dsgs) and desmocollins, make up the adhesive core of intercellular junctions called desmosomes. A critical determinant of epithelial adhesive strength is the level and organization of desmosomal cadherins on the cell surface. The Dsg subclass of desmosomal cadherins contains a C-terminal unique region (Dsg unique region [DUR]) with unknown function. In this paper, we show that the DUR of Dsg2 stabilized Dsg2 at the cell surface by inhibiting its internalization and promoted strong intercellular adhesion. DUR also facilitated Dsg tail–tail interactions. Forced dimerization of a Dsg2 tail lacking the DUR led to decreased internalization, supporting the conclusion that these two functions of the DUR are mechanistically linked. We also show that a Dsg2 mutant, V977fsX1006, identified in arrhythmogenic right ventricular cardiomyopathy patients, led to a loss of Dsg2 tail self-association and underwent rapid endocytosis in cardiac muscle cells. Our observations illustrate a new mechanism desmosomal cadherins use to control their surface levels, a key factor in determining their adhesion and signaling roles.

Chen, Jing; Nekrasova, Oxana E.; Patel, Dipal M.; Klessner, Jodi L.; Godsel, Lisa M.; Koetsier, Jennifer L.; Amargo, Evangeline V.; Desai, Bhushan V.

2012-01-01

258

Active tails enhance arboreal acrobatics in geckos.  

PubMed

Geckos are nature's elite climbers. Their remarkable climbing feats have been attributed to specialized feet with hairy toes that uncurl and peel in milliseconds. Here, we report that the secret to the gecko's arboreal acrobatics includes an active tail. We examine the tail's role during rapid climbing, aerial descent, and gliding. We show that a gecko's tail functions as an emergency fifth leg to prevent falling during rapid climbing. A response initiated by slipping causes the tail tip to push against the vertical surface, thereby preventing pitch-back of the head and upper body. When pitch-back cannot be prevented, geckos avoid falling by placing their tail in a posture similar to a bicycle's kickstand. Should a gecko fall with its back to the ground, a swing of its tail induces the most rapid, zero-angular momentum air-righting response yet measured. Once righted to a sprawled gliding posture, circular tail movements control yaw and pitch as the gecko descends. Our results suggest that large, active tails can function as effective control appendages. These results have provided biological inspiration for the design of an active tail on a climbing robot, and we anticipate their use in small, unmanned gliding vehicles and multisegment spacecraft. PMID:18347344

Jusufi, Ardian; Goldman, Daniel I; Revzen, Shai; Full, Robert J

2008-03-18

259

The human tail and spinal dysraphism.  

PubMed

Recent publications have endeavoured to differentiate between the true, or vestigial tail, and the pseudotail by clinical and pathological examination, and have indicated the benign nature of the true tail. The true tail arises from the most distal remnant of the embryonic tail, contains adipose, connective, muscle, and nerve tissue, and is covered by skin. Pseudotails represent a variety of lesions having in common a lumbosacral protrusion and a superficial resemblance to vestigial tails. A review of the case reports indicates spina bifida to be the most frequent coexisting anomaly with both. A review of occult spinal dysraphism shows it to be associated with cutaneous signs in more than 50% of instances. Three cases of spinal dysraphism with tail-like cutaneous structures are described and their radiological, operative, and pathological findings presented. The classification of each of the appendages into true tail or pseudotail remains obscure. Although the finding of these three tails was the subject of much curiosity, surgical treatment was clearly designed to adequately deal with the associated dysraphic state. The presence of a tail-like appendage in the lumbosacral region should alert the clinician to the possibility of underlying spinal dysraphism. Preoperative assessment must include a complete neurological history and examination as well as computed tomographic or magnetic resonance imaging. PMID:1779337

Belzberg, A J; Myles, S T; Trevenen, C L

1991-10-01

260

Arsenic Fractionation in Tailing Piles in Zimapán, Hidalgo, México  

NASA Astrophysics Data System (ADS)

Zimapán, Hidalgo, is located in a semiarid region in the central part of México and has been one of the main mining district of this country. As a result of the mining activities, residual material has been deposited in the surroundings of town. Arsenic ground water pollution has been reported produced by natural and antropogenic sources . X-ray diffraction showed presence of sulfide minerals in tailing piles, such as arsenopyrite. To determine the arsenic mobility, samples from tailings were analyzed by sequential extraction procedure. Arsenic was determined on extraction solutions at each step by HG-AAS. The extraction was done with different chemicals to determine As exchangeable, As bound to carbonates or specifically adsorbed, As bound to Fe-Al oxides, As bound to organic matter and sulfides, and As residual. Most of the arsenic was contained in the Fe-Al oxides an residual fractions. Nevertheless The As content in the exchangeable fraction was found to be of environmental risk.

Ceniceros, N.

2001-12-01

261

MESSENGER observations of extreme loading and unloading of Mercury's magnetic tail.  

PubMed

During MESSENGER's third flyby of Mercury, the magnetic field in the planet's magnetic tail increased by factors of 2 to 3.5 over intervals of 2 to 3 minutes. Magnetospheric substorms at Earth are powered by similar tail loading, but the amplitude is lower by a factor of approximately 10 and typical durations are approximately 1 hour. The extreme tail loading observed at Mercury implies that the relative intensity of substorms must be much larger than at Earth. The correspondence between the duration of tail field enhancements and the characteristic time for the Dungey cycle, which describes plasma circulation through Mercury's magnetosphere, suggests that such circulation determines the substorm time scale. A key aspect of tail unloading during terrestrial substorms is the acceleration of energetic charged particles, but no acceleration signatures were seen during the MESSENGER flyby. PMID:20647422

Slavin, James A; Anderson, Brian J; Baker, Daniel N; Benna, Mehdi; Boardsen, Scott A; Gloeckler, George; Gold, Robert E; Ho, George C; Korth, Haje; Krimigis, Stamatios M; McNutt, Ralph L; Nittler, Larry R; Raines, Jim M; Sarantos, Menelaos; Schriver, David; Solomon, Sean C; Starr, Richard D; Trávnícek, Pavel M; Zurbuchen, Thomas H

2010-08-01

262

Tracing the tail of ubiquinone in mitochondrial complex I.  

PubMed

Mitochondrial complex I (proton pumping NADH:ubiquinone oxidoreductase) is the largest and most complicated component of the respiratory electron transfer chain. Despite its central role in biological energy conversion the structure and function of this membrane integral multiprotein complex is still poorly understood. Recent insights into the structure of complex I by X-ray crystallography have shown that iron-sulfur cluster N2, the immediate electron donor for ubiquinone, resides about 30Å above the membrane domain and mutagenesis studies suggested that the active site for the hydrophobic substrate is located next to this redox-center. To trace the path for the hydrophobic tail of ubiquinone when it enters the peripheral arm of complex I, we performed an extensive structure/function analysis of complex I from Yarrowia lipolytica monitoring the interaction of site-directed mutants with five ubiquinone derivatives carrying different tails. The catalytic activity of a subset of mutants was strictly dependent on the presence of intact isoprenoid moieties in the tail. Overall a consistent picture emerged suggesting that the tail of ubiquinone enters through a narrow path at the interface between the 49-kDa and PSST subunits. Most notably we identified a set of methionines that seems to form a hydrophobic gate to the active site reminiscent to the M-domains involved in the interaction with hydrophobic targeting sequences with the signal recognition particle of the endoplasmic reticulum. Interestingly, two of the amino acids critical for the interaction with the ubiquinone tail are different in bovine complex I and we could show that one of these exchanges is responsible for the lower sensitivity of Y. lipolytica complex I towards the inhibitor rotenone. This article is part of a Special Issue entitled: 17th European Bioenergetics Conference (EBEC 2012). PMID:22484275

Angerer, Heike; Nasiri, Hamid R; Niedergesäß, Vanessa; Kerscher, Stefan; Schwalbe, Harald; Brandt, Ulrich

2012-10-01

263

Engineering assessment of inactive uranium mill tailings: Monument Valley Site, Monument Valley, Arizona  

SciTech Connect

Ford, Bacon and Davis Utah Inc. has reevalated the Monument Valley site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Monument Valley, Arizona. 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 exposure 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 1.1 million tons of tailings at the Monument Valley site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite 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 IV). Cost estimates for the four options range from about $6,600,000 for stabilization in-place, to about $15,900,000 for disposal at a distance of about 15 mi. Three principal alternatives for reprocessing the Monument Valley 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 recovery is economically unattractive.

Not Available

1981-10-01

264

Rapid plant-cover establishment on gold mine tailings in southern New Zealand: glasshouse screening trials.  

PubMed

The use of a short-term vegetation cover to temporarily control the negative environmental effects of inactive tailings ponds is notfrequently practiced during operational mining, but could have some merit This article reports on a glasshouse trial designed to examine some of the issues associated with short-term vegetation: fast germination of a high proportion of seed, the ability of seedlings to survive in unamended substrates, and potentially toxic substrate. Five nonindigenous plant species were tested--barley (Hordeum vulgare), rye corn (Secale cereale), Italian ryegrass (Lolium multifiorum), red clover (Trifolium pratense), and lucerne (Medicago sativa)--in five different types of substrate: unamended tailings, tailings and fertilizer, tailings and greenwaste, biosolid-blend compost, and local topsoil. The nutrient and heavy metal status (As, Cu, Cd, Ni, Pb) of each substrate type was determined Plant species performance was monitored over 14 wk Substrate metal concentrations were low except for As, which was elevated in all substrate types. Plants in unamended tailings grew less vigorously than plants in tailings and compost or in topsoil. Plant performance in tailings and fertiliser was greatly suppressed following a high fertilization rate. Metal uptake in plants was highest for As (0.4-77 mg kg(-1) DW) and Cu (5.3-50.3 mg kg(-1) DW). Future field trials are necessary to authenticate findings, but barley and rye corn are promising species for a short-term tailings cover. PMID:16463543

Schroeder, K; Rufaut, C G; Smith, C; Mains, D; Craw, D

2005-01-01

265

Hydrodynamic Characteristics of a Low-drag, Planing-tail Flying-boat Hull  

NASA Technical Reports Server (NTRS)

The hydrodynamic characteristics of a flying-boat incorporating a low-drag, planing-tail hull were determined from model tests made in Langley tank number 2 and compared with tests of the same flying boat incorporating a conventional-type hull. The planing-tail model, with which stable take-offs were possible for a large range of elevator positions at all center-of-gravity locations tested, had more take-off stability than the conventional model. No upper-limit porpoising was encountered by the planing-tail model. The maximum changes in rise during landings were lower for the planing-tail model than for the conventional model at most contact trims, an indication of improved landing stability for the planing-tail model. The hydrodynamic resistance of the planing-tail hull was lower than the conventional hull at all speeds, and the load-resistance ratio was higher for the planing-tail hull, being especially high at the hump. The static trim of the planing-tail hull was much higher than the conventional hull, but the variation of trim with speed during take-off was smaller.

Suydam, Henry B

1948-01-01

266

On the persistence of unstable bump-on-tail electron velocity distributions in the earth's foreshock  

SciTech Connect

Further evidence for the persistence of bump-on-tail unstable reduced velocity distribution in the Earth's electron foreshock is presented. This persistence contradicts our understanding of quasi-linear saturation of the bump-on-tail instability; the distributions should be stabilized through velocity space diffusion too quickly to allow an observation of their unstable form. A modified theory for the saturation of the bump-on-tail instability in the Earth's foreshock is proposed and examined using numerical simulation and quasi-linear theoretical techniques. It is argued the mechanism due to Filbert and Kellogg and to Cairns which is responsible for the creation of the bump-on-tail velocity distribution in the foreshock is still operative during the evolution of the bump-on-tail instability. The saturated state of the plasma must represent a balance between this creation mechanism and velocity space diffusion; the saturated state is not determined by velocity space diffusion alone. Thus the velocity distribution of the saturated stat may still appear bump-on-tail unstable to standard linear analysis which does not take the creation mechanism into account. The bump-on-tail velocity distributions in the foreshock would then represent the state of the plasma after saturation of the bump-on-tail instability, not before.

Klimas, A.J.; Fitzenreiter, R.J.

1988-09-01

267

226Ra bioavailability to plants at the Urgeiriça uranium mill tailings site.  

PubMed

Large amounts of solid wastes (tailings) resulting from the exploitation and treatment of uranium ore at the Urgeiriça mine (north of Portugal) have been accumulated in dams (tailing ponds). To reduce the dispersion of natural radionuclides into the environment, some dams were revegetated with eucalyptus (Eucalyptus globolus) and pines (Pinus pinea). Besides these plants, some shrubs (Cytisus spp.) are growing in some of the dams. The objective of this study is to determine the 226Ra bioavailability from uranium mill tailings by quantifying the total and available fraction of radium in the tailings and to estimate its transfer to plants growing on the tailing piles. Plant and tailing samples were randomly collected and the activity concentration of 226Ra in plants (aerial part and roots) and tailings was measured by gamma-spectrometry. The exchangeable fraction of radium in tailings was quantified using one single step extraction with 1 mol dm-3 ammonium acetate (pH = 7) or 1 mol dm-3 calcium chloride solutions. The results obtained for 226Ra uptake by plants show that 226Ra concentration ratios for eucalyptus and pines decrease at low 226Ra concentrations in the tailings and appear relatively constant at higher radium concentrations. For shrubs, the concentration ratios increase at higher 226Ra solid waste concentrations approaching a saturation value. Percentage values of 16.0 +/- 8.3 and 12.9 +/- 8.9, for the fraction of radium extracted from the tailings, using 1 mol dm-3 ammonium acetate or calcium chloride solutions, respectively, were obtained. The 226Ra concentration ratios determined on the basis of exchangeable radium are one order of magnitude higher than those based on total radium. It can be concluded that, at a 95% confidence level, more consistent 226Ra concentration ratios were obtained when calculated on the basis of available radium than when total radium was considered, for all the dams. PMID:11379070

Madruga, M J; Brogueira, A; Alberto, G; Cardoso, F

2001-01-01

268

Investigation of contamination of earthen covers on inactive uranium mill tailings  

SciTech Connect

The upward migration of contaminants into earthen covers on uranium mill tailings was evaluated from chemical and isotopic analysis of samples from 5--10 cm intervals through the cover and into the tailings at three locations on the Riverton pile. The Uranium Mill Tailings Remedial Action Project elected to determine the significance of migration of salts and contaminants into earthen covers emplaced on tailings by funding this investigation of the migration which has occurred through an earthen cover since the time of emplacement on an inactive uranium mill tailings pile. The Riverton tailings pile, covered with 20 to 40 cm of local sandy soil, was chosen for the study. The objectives of the study were to: determine vertical distributions of concentrations of salts, trace metals, and radionuclides through the cover and into the tailings; determine the concentrations of salts and contaminants in the cover from chemical migration; relate the migration of salts to the contaminants; model the mechanisms responsible for promoting and retarding migration; and evaluate the chemical and physical properties of the cover influencing migration. 20 refs., 35 figs., 10 tabs.

Markos, G.; Bush, K.J.

1983-01-01

269

Quantitative Trait Loci Involved in Sex Determination and Body Growth in the Gilthead Sea Bream (Sparus aurata L.) through Targeted Genome Scan  

PubMed Central

Among vertebrates, teleost fish exhibit a considerably wide range of sex determination patterns that may be influenced by extrinsic parameters. However even for model fish species like the zebrafish Danio rerio the precise mechanisms involved in primary sex determination have not been studied extensively. The zebrafish, a gonochoristic species, is lacking discernible sex chromosomes and the sex of juvenile fish is difficult to determine. Sequential protandrous hermaphrodite species provide distinct determination of the gender and allow studying the sex determination process by looking at the mechanism of sex reversal. This is the first attempt to understand the genetic basis of phenotypic variation for sex determination and body weight in a sequential protandrous hermaphrodite species, the gilthead sea bream (Sparus aurata). This work demonstrates a fast and efficient strategy for Quantitative Trait Loci (QTL) detection in the gilthead sea bream, a non-model but target hermaphrodite fish species. Therefore a comparative mapping approach was performed to query syntenies against two other Perciformes, the European sea bass (Dicentrarchus labrax), a gonochoristic species and the Asian sea bass (Lates calcarifer) a protandrous hermaphrodite. In this manner two significant QTLs, one QTL affecting both body weight and sex and one QTL affecting sex, were detected on the same linkage group. The co-segregation of the two QTLs provides a genomic base to the observed genetic correlation between these two traits in sea bream as well as in other teleosts. The identification of QTLs linked to sex reversal and growth, will contribute significantly to a better understanding of the complex nature of sex determination in S. aurata where most individuals reverse to the female sex at the age of two years through development and maturation of the ovarian portion of the gonad and regression of the testicular area. [Genomic sequences reported in this manuscript have been submitted to GenBank under accession numbers HQ021443–HQ021749.

Loukovitis, Dimitrios; Sarropoulou, Elena; Tsigenopoulos, Costas S.; Batargias, Costas; Magoulas, Antonios; Apostolidis, Apostolos P.; Chatziplis, Dimitrios; Kotoulas, Georgios

2011-01-01

270

Quantitative trait loci involved in sex determination and body growth in the gilthead sea bream (Sparus aurata L.) through targeted genome scan.  

PubMed

Among vertebrates, teleost fish exhibit a considerably wide range of sex determination patterns that may be influenced by extrinsic parameters. However even for model fish species like the zebrafish Danio rerio the precise mechanisms involved in primary sex determination have not been studied extensively. The zebrafish, a gonochoristic species, is lacking discernible sex chromosomes and the sex of juvenile fish is difficult to determine. Sequential protandrous hermaphrodite species provide distinct determination of the gender and allow studying the sex determination process by looking at the mechanism of sex reversal. This is the first attempt to understand the genetic basis of phenotypic variation for sex determination and body weight in a sequential protandrous hermaphrodite species, the gilthead sea bream (Sparus aurata). This work demonstrates a fast and efficient strategy for Quantitative Trait Loci (QTL) detection in the gilthead sea bream, a non-model but target hermaphrodite fish species. Therefore a comparative mapping approach was performed to query syntenies against two other Perciformes, the European sea bass (Dicentrarchus labrax), a gonochoristic species and the Asian sea bass (Lates calcarifer) a protandrous hermaphrodite. In this manner two significant QTLs, one QTL affecting both body weight and sex and one QTL affecting sex, were detected on the same linkage group. The co-segregation of the two QTLs provides a genomic base to the observed genetic correlation between these two traits in sea bream as well as in other teleosts. The identification of QTLs linked to sex reversal and growth, will contribute significantly to a better understanding of the complex nature of sex determination in S. aurata where most individuals reverse to the female sex at the age of two years through development and maturation of the ovarian portion of the gonad and regression of the testicular area. [Genomic sequences reported in this manuscript have been submitted to GenBank under accession numbers HQ021443-HQ021749.]. PMID:21304996

Loukovitis, Dimitrios; Sarropoulou, Elena; Tsigenopoulos, Costas S; Batargias, Costas; Magoulas, Antonios; Apostolidis, Apostolos P; Chatziplis, Dimitrios; Kotoulas, Georgios

2011-01-01

271

Using comet plasma tails to study the solar wind  

NASA Astrophysics Data System (ADS)

The plasma tails of comets have been used as probes of the solar wind for many years, and well before direct solar wind measurements. Now, analyses utilizing the much greater regularity and extent of comet tails imaged from space detail outward solar wind flow much better than was previously possible. These analyses mark the location of the solar wind flow in three-dimensions over time much as do in-situ measurements. Data from comet plasma tails using coronagraphs and heliospheric white-light imagers provide a view closer to the Sun than where spacecraft have ventured to date. These views show that this flow is chaotic and highly variable, and not the benign regular outward motion of a quiescent plasma. While this is no surprise to those who study and characterize the solar wind in situ or use remotely-sensed interplanetary scintillation (IPS) techniques, these spacecraft images provide a visualization of this as never-before possible. Here we summarize the results of an analysis that determines solar wind velocity from multiple comet tails that were observed by the Solar Mass Ejection Imager (SMEI) and also by the inner Heliospheric Imager (HI) on board the Solar Terrestrial Relations Observatory Ahead (STEREOA) spacecraft. Finally, we present results using a similar analysis that measures this same behavior using coronagraph observations in the low corona.

Jackson, B. V.; Buffington, A.; Clover, J. M.; Hick, P. P.; Yu, H.-S.; Bisi, M. M.

2013-06-01

272

Cross-tail current evolution during substorm dipolarization  

NASA Astrophysics Data System (ADS)

We examine evolution of the cross-tail current during substorm current disruption/dipolarization using observations from two satellites in the near-Earth magnetotail at the downtail distances of 8-9 RE. By choosing times when these two satellites are separated, mainly in the north-south distance in the tail current sheet, precise determination of current density in the layer embedded between these satellites can be obtained with Ampère's law. Two such events are examined and several common features are found. The current densities in the layer embedded by the two satellites were reduced by ~ 40-70% during substorm dipolarization. The changes in current densities have the fast kinetic timescale, i.e., in seconds, implying a kinetic process for current disruption/dipolarization. The estimated power within the current layer was mainly dissipative in the dawn-dusk direction and mainly dynamo in the Sun-tail direction that is needed to drive the north-south substorm current system in the ionosphere. Remote sensing of the energization site with the ion sounding technique shows that the energization site was initially earthward of the satellite and moved down the tail at later times. Breakdown of the frozen-in condition occurred intermittently during the disturbance interval. These features provide important clues to the substorm onset process.

Lui, A. T. Y.

2013-06-01

273

Moisture content analysis of covered uranium mill tailings  

SciTech Connect

The use of vegetation and rock covers to stabilize uranium mill tailings cover systems is being investigated by Pacific Northwest Laboratory. A modeling study of moisture movement through the tailings and cover layers was initiated to determine the effect of the stabilizing techniques. The cover system was simulated under climatic conditions occurring at Grand Junction, Colorado. The cover consisted of a layer of wet clay/gravel mix followed by a capillary barrier of washed rock and a surface layer of fill soil. Vegetation and rock were used to stabilize the surface layer. The simulation yielded moisture content and moisture storage values for the tailings and cover system along with information about moisture losses due to evaporation, transpiration, and drainage. The study demonstrates that different surface stabilization treatments lead to different degrees of moisture retention in the covered tailings pile. The evapotranspiration from vegetation can result in a relatively stable moisture content. Rock covers, however, may cause drainage to occur because they reduce evaporation and lead to a subsequent increase in moisture content. It is important to consider these effects when designing a surface stabilization treatment. Drainage may contribute to a groundwater pollution problem. A surface treatment that allows the cover system to dry out can increase the risk of atmospheric contamination through elevated radon emission rates.

Mayer, D.W.; Beedlow, P.A.; Cadwell, L.L.

1981-12-01

274

Identification of regions interacting with ovo{sup D} mutations: Potential new genes involved in germline sex determination or differentiation in Drosophila melanogaster  

SciTech Connect

Only a few Drosophila melanogaster germline sex determination genes are known, and there have been no systematic screens to identify new genes involved in this important biological process. The ovarian phenotypes produced by females mutant for dominant alleles of the ovo gene are modified in flies with altered doses of other loci involved in germline sex determination in Drosophila (Sex-lethal{sup +}, snas fille{sup +} and ovarian tumor{sup +}). This observation constitutes the basis for a screen to identify additional genes required for proper establishment of germline sexual identity. We tested 300 deletions, which together cover {approximately}58% of the euchromatic portion of the genome, for genetic interactions with ovo{sup D}. Hemizygosity for more than a dozen small regions show interactions that either partially suppress or enhance the ovarian phenotypes of females mutant for one or more of the three dominant ovo mutations. These regions probably contain genes whose products act in developmental heirarchies that include ovo{sup +} protein. 40 refs, 7 figs., 5 tabs.

Pauli, D.; Oliver, B.; Mahowald, A.P. [Case Western Reserve Univ., Cleveland, OH (United States)

1995-02-01

275

Comet tail formation: Giotto observations  

SciTech Connect

The process of mass loading of the solar wind by cometary ions, which forms comet tails, has been observed throughout the coma of comet Halley. Three distinct regimes were found where the nature of the energy and momentum coupling between solar wind and cometary ions is different. Outside the bow shock, where there is little angular scattering of the freshly ionized particles, the coupling is described by the simple pickup trajectory and the energy is controlled by the angle between the flow and the magnetic field. Just inside the bow shock, there is considerable scattering accompanied by another acceleration process which raises some particle energies well above the straightforward pickup value. Finally, closer to the nucleus, the amount of scattering decreases and the coupling is once more controlled by the magnetic field direction. 4 refs., 3 figs.

Wilken, B.; Jockers, K.; Johnstone, A.; Coates, A.; Heath, J.; Formisano, V.; Amata, E.; Winningham, J.D.; Thomsen, M.; Bryant, D.A.

1986-01-01

276

The genetics of colour in fat-tailed sheep: a review.  

PubMed

Fat-tailed sheep come in various colours-most are either brown (tan) or black. In some, most of the body is white with the tan or black colour restricted to the front portion of the body or to just around the eyes, muzzle and parts of the legs. The Karakul breed is important for the production of lamb skins of various colours for the fashion industry. As well as the black and tan colours there are Karakuls bred for grey or roan shades, a white colour or one of the numerous Sur shades. In the Sur shades, the base of the birthcoat fibre is one of a number of dark shades and the tip a lighter or white shade. All these colours and many others are the result of the interaction of various genes that determine the specifics of the coat colour of the sheep. A number of sets of nomenclature and symbols have been used to represent the various loci and their alleles that are involved. In the 1980s and 1990s, a standardised set, based closely on those of the mouse and other species was developed. Using this as the framework, the alleles of the Extension, Agouti, Brown, Spotting, Pigmented Head and Roan loci are described using fat-tailed sheep (mainly Damara, Karakul and Persian) as examples. Further discussion includes other types of "white markings," the Ticking locus and the Sur loci. PMID:21544704

Lundie, Roger S

2011-10-01

277

Stability properties of a cometary plasma tail  

Microsoft Academic Search

The linear stability of the plasma tail of a comet is numerically investigated. Effects both of finite resistivity and of velocity shear are taken into account. The tail appears to be unstable against Kelvin-Helmholtz-like modes in which a certain amount of reconnection occurs. Because of the velocity flow shear the perturbation extends far beyond the singular layer and affects in

Francesco Malara; Giorgio Einaudi; Andre Mangeney

1989-01-01

278

CISLUNAR GEOMAGNETIC TAIL GRADIENT IN 1967  

Microsoft Academic Search

In this letter, the geomagnetic tail field gradient during the summers of 1966 and 1967 is examined for secular change. We use data from Ames magnetometers on Explorers 33 and 35. The 1967 data are compared with the earlier published 1966. Explorer 33 results [Mihalo. v et al., 1968]. Secular change of the tail field magnitude gradient is not found

J. D. Mihalov; C. P. Sonett

1968-01-01

279

Tale of tails: Parallelism and prehensility  

Microsoft Academic Search

The occurrence of prehensile tails among only five platyrrhine genera-Cebus, Alouatta, Lagothrix, Ateles, and Bmchyteles-might be inter- preted as evidence that these are a closely related, possibly monophyletic group. In the absence of behavioral data, it is impossible to test whether all possess equivalent biological roles; such would lend credence to the idea that their tails evolved from an homologous,

Alfred L. Rosenberger

1983-01-01

280

Unified Approach to Estimating Tail Behavior.  

National Technical Information Service (NTIS)

Tail estimators are proposed which make minimal assumptions and let the data dictate the form of the probability model. These estimators use only the observations in the tail and are based on a unifying density-quantile model. The fundamental result in th...

S. D. Grimshaw

1989-01-01

281

Factors influencing radon attenuation by tailing covers  

Microsoft Academic Search

The US NRC, in its Generic Environmental Impact Statement on uranium milling has specified that the radon flux escaping a uranium mill tailings pile will be reduced to pCi\\/m² s by application of covering layers of soils and clays. These covers present a radon diffusion barrier, which sufficiently increases the time required for radon passage from the tailings to the

W. B. Silker; V. C. Rogers

1981-01-01

282

Groundwater pollution due to a tailings dam  

Microsoft Academic Search

In 1982, the Oman Mining Company (OMC) commenced copper mining and smelting operations in the area of Sohar (Wadi Suq), Sultanate of Oman. Seawater was used for mining operations until 1993. During this period, 11 million tonnes of tailings had been deposited behind an unlined tailings dam. This has resulted in a major groundwater pollution problem.This paper presents results from

R. S Sharma; T. S Al-Busaidi

2001-01-01

283

EXPERIMENTAL RESEARCH ON HELICOPTER TAIL SHAKE PHENOMENON  

Microsoft Academic Search

Helicopter tail shake phenomenon is still remained as a long dragged issue that adversely affected the overall performance, occupants' comfort and handling qualities of helicopter. The objective of this research is to improve basic understanding of the viscous unsteady flow phenomenon observed behind the helicopter tail part. For this, a wind tunnel test had been conducted with a rigid 14%

Iskandar Shah Ishak; Shuhaimi Mansor; Tholudin Mat Lazim

284

The histone tails of the nucleosome  

Microsoft Academic Search

Reversible acetylation of core histone tails plays an important role in the regulation of eukaryotic transcription, in the formation of repressive chromatin complexes, and in the inactivation of whole chromosomes. The high-resolution X-ray structure of the nucleosome core particle, as well as earlier evidence, suggests that the histone tails are largely responsible for the assembly of nucleosomes into chromatin fibers

Karolin Luger; Timothy J Richmond

1998-01-01

285

CONFIGURATION AND RECONNECTION OF THE GEOMAGNETIC TAIL  

Microsoft Academic Search

A description of certain aspects of the geomagnetic tail is made using data from the Ames magnetometer on the Explorer 33 satellite. The general shape corresponds with eaxlier findings of Ness and co-workers. The tail is found regular to distances greater than 82 R. The field values for Kp _ 2-]- vary from a low of about 4 gammas to

J. D. Mihalov; D. S. Colburn; R. G. Currie; C. P. Sonett

1968-01-01

286

The QQ-Estimator And Heavy Tails  

Microsoft Academic Search

. A common visual technique for assessing goodness of fit and estimating location and scale is theqq--plot. We apply this technique to data from a Pareto distribution and more generally to data generated bya distribution with a heavy tail. A procedure for assessing the presence of heavy tails and for estimating theparameter of regular variation is discussed which can supplement

Marie F. Kratz; Sidney I. Resnick

1995-01-01

287

Flight Investigation to Determine the Aerodynamic Characteristics of Rocket-Powered Models Representative of a Fighter-Type Airplane Configuration Incorporating an Inverse-Taper Wing and a Vee Tail  

NASA Technical Reports Server (NTRS)

Two rocket-powered models representative of a fighter-type airplane were investigated in flight at Mach numbers up to 1.01 and 1.07 by the Langley Pilotless Aircraft Research Division at its testing station at Wallops Island, Va. These models incorporated an inverse-taper wing and a vee tail and were flown with controls undeflected and wing and stabilizer set at 0 deg incidence. Values of lateral acceleration, normal acceleration velocity, and drag were obtained by use of telemeters and a Doppler velocimeter radar unit. The results of this investigation indicated no unusual variation in the lateral acceleration characteristics. After the cessation of powered flight, the lateral oscillation quickly damped to zero. The data indicated that the airplane, at low lift coefficients, should not experience any abrupt trim changes until it attains a Mach number of 0.97. The change in normal-force coefficient associated with this trim change will amount to about 0.03 with the center of gravity located at 4.48% of the mean aerodynamic chord. At higher lift coefficients, on the basis of other data, the Mach number at which this trim change occurs would be expected to be decreased. The neutral point of the model at Mach numbers near 1.05 was estimated to fall at 45% of the mean aerodynamic chord, assuming a lift-curve slope of 0.05. A value of the static-directional-stability parameter dCn/d(psi) of approximately -0.002 was estimated for a Mach number of 0.93. The values of drag coefficient obtained from both model flights were in a good comparative agreement. The highest drag coefficient occurred at a Mach number of 1.01 and was equal to 0.044.

Alexander, Sidney R.

1948-01-01

288

Weathering in coal mine rejects and tailings - variation with respect to depth  

SciTech Connect

Acid production or acid drainage is a major environmental issue that also has negative implications on the aquifer system surrounding the mine tailings area. The approach to controlling acid mine drainage involves physical and geochemical characterization that affect acid production. The material permeability determines the availability of oxygen, which is paramount in acid production in coal rejects, and varies with depth. In this paper the author presents the variation in oxidized pyrite/acid production with depth in black coal mine washery wastes. Chemical kinetic parameters and the diffusive parameters have been used to obtain the variation in oxygen content and the oxidized pyrite content with respect to the depth and time. Its dependence on porosity and moisture content is illustrated.

Devasahayam, S.

2007-02-15

289

Mutagenesis of pairwise combinations of histone amino-terminal tails reveals functional redundancy in budding yeast  

PubMed Central

A large body of literature provides compelling evidence for the role of evolutionarily conserved core histone residues in various biological processes. However, site-directed mutagenesis of individual residues that are known to be sites of posttranslational modifications often does not result in clear phenotypic defects. In some cases, the combination of multiple mutations can give rise to stronger phenotypes, implying functional redundancy between distinct residues on histones. Here, we examined the “histone redundancy hypothesis” by characterizing double deletion of all pairwise combinations of amino-terminal tails (N-tails) from the four core histones encoded in budding yeast. First, we found that multiple lysine residues on the N-tails of both H2A and H4 are redundantly involved in cell viability. Second, simultaneous deletion of N-tails from H2A and H3 leads to a severe growth defect, which is correlated with perturbed gross chromatin structure in the mutant cells. Finally, by combining point mutations on H3 with deletion of the H2A N-tail, we revealed a redundant role for lysine 4 on H3 and the H2A N-tail in hydroxyurea-mediated response. Altogether, these data suggest that the N-tails of core histones share previously unrecognized, potentially redundant functions that, in some cases are different from those of the widely accepted H2A/H2B and H3/H4 dimer pairs.

Kim, Jung-Ae; Hsu, Jer-Yuan; Smith, M. Mitchell; Allis, C. David

2012-01-01

290

The Dust Tail of Asteroid (3200) Phaethon  

NASA Astrophysics Data System (ADS)

We report the discovery of a comet-like tail on asteroid (3200) Phaethon when imaged at optical wavelengths near perihelion. In both 2009 and 2012, the tail appears gsim350'' (2.5 × 108 m) in length and extends approximately in the projected anti-solar direction. We interpret the tail as being caused by dust particles accelerated by solar radiation pressure. The sudden appearance and the morphology of the tail indicate that the dust particles are small, with an effective radius ~1 ?m and a combined mass ~3 × 105 kg. These particles are likely products of thermal fracture and/or desiccation cracking under the very high surface temperatures (~1000 K) experienced by Phaethon at perihelion. The existence of the tail confirms earlier inferences about activity in this body based on the detection of anomalous brightening. Phaethon, the presumed source of the Geminid meteoroids, is still active.

Jewitt, David; Li, Jing; Agarwal, Jessica

2013-07-01

291

Human sperm tail proteome suggests new endogenous metabolic pathways.  

PubMed

Proteomic studies are contributing greatly to our understanding of the sperm cell, and more detailed descriptions are expected to clarify additional cellular and molecular sperm attributes. The aim of this study was to characterize the subcellular proteome of the human sperm tail and, hopefully, identify less concentrated proteins (not found in whole cell proteome studies). Specifically, we were interested in characterizing the sperm metabolic proteome and gaining new insights into the sperm metabolism issue. Sperm were isolated from normozoospermic semen samples and depleted of any contaminating leukocytes. Tail fractions were obtained by means of sonication followed by sucrose-gradient ultracentrifugation, and their purity was confirmed via various techniques. Liquid chromatography and tandem mass spectrometry of isolated sperm tail peptides resulted in the identification of 1049 proteins, more than half of which had not been previously described in human sperm. The categorization of proteins according to their function revealed two main groups: proteins related to metabolism and energy production (26%), and proteins related to sperm tail structure and motility (11%). Interestingly, a great proportion of the metabolic proteome (24%) comprised enzymes involved in lipid metabolism, including enzymes for mitochondrial beta-oxidation. Unexpectedly, we also identified various peroxisomal proteins, some of which are known to be involved in the oxidation of very long chain fatty acids. Analysis of our data using Reactome suggests that both mitochondrial and peroxisomal pathways might indeed be active in sperm, and that the use of fatty acids as fuel might be more preponderant than previously thought. In addition, incubation of sperm with the fatty acid oxidation inhibitor etomoxir resulted in a significant decrease in sperm motility. Contradicting a common concept in the literature, we suggest that the male gamete might have the capacity to obtain energy from endogenous pools, and thus to adapt to putative exogenous fluctuations. PMID:23161514

Amaral, Alexandra; Castillo, Judit; Estanyol, Josep Maria; Ballescà, José Luís; Ramalho-Santos, João; Oliva, Rafael

2013-02-01

292

Measurement of radon diffusion from uranium mill tailing piles  

Microsoft Academic Search

The concentrations of ²²⁶Ra and ²²²Rn (²¹⁴Pb) were measured as a function of depth within a uranium mill tailings pile by in-situ gamma-ray spectrometry. Radon diffusion and exhalation rates were determined from the concentration gradients by employing an integral solution of the diffusion equation that accommodates a nonuniform depth distribution of the parent radium. Radon diffusion coefficients of 0.0002 and

W. B. Silker; N. A. Wogman; C. W. Thomas; D. B. Carr; P. C. Heasler

1979-01-01

293

Experimental mechanistic studies of the tail-to-tail dimerization of methyl methacrylate catalyzed by N-heterocyclic carbene.  

PubMed

We and others have previously reported the intermolecular umpolung reactions of Michael acceptors catalyzed by an N-heterocyclic carbene (NHC). The representative tail-to-tail dimerization of methyl methacrylate (MMA) has now been intensively investigated, leading to the following conclusions: (1) The catalysis involves the deoxy-Breslow intermediate, which is quite stable and remains active after the catalysis. (2) Addition of the intermediate to MMA and the final catalyst elimination are the rate-limiting steps. Addition of the NHC to MMA and the proton transfers are relatively very rapid. (3) The two alkenyl protons of the first MMA undergo an intermolecular transfer to C3 and C5 of the dimer. (4) The initial proton transfer is intermolecular. (5) Compared with the benzoin condensation, noticeable differences in the kinetics, reversibility, and stability of the intermediates are observed. PMID:23941561

Kato, Terumasa; Ota, Yoshiya; Matsuoka, Shin-ichi; Takagi, Koji; Suzuki, Masato

2013-09-01

294

Effect of Apex Flap Deflection on Vertical Tail Buffeting  

NASA Technical Reports Server (NTRS)

A computational study of the effect of vortex breakdown location on vertical tail buffeting is conducted. The position of the breakdown is modified by employing an apex flap deflected by an experimentally determined optimal angle. The delayed breakdown flow and buffeting response is then compared to the nominal undeflected case. This multidisciplinary problem is solved sequentially for the fluid flow, the elastic tail deformations and the grid displacements. The fluid flow is simulated by time accurately solving the unsteady, compressible, Reynolds-averaged Navier-Stokes equations using an implicit, upwind, flux-difference splitting finite volume scheme. The elastic vibrations of the tails are modeled by uncoupled bending and torsion beam equations. These equations are solved accurately in time using the Galerkin method and a five-stage Runge-Kutta-Verner scheme. The grid for the fluid dynamics calculations is continuously deformed using interpolation functions to disperse the displacements smoothly throughout the computational domain. An angle-of-attack of 35 deg.is chosen such that the wing primary-vortex cores experience vortex breakdown and the resulting turbulent wake flow impinges on tile vertical tails. The dimensions and material properties of the vertical tails are chosen such that the deflections are large enough to insure interaction with the flow, and the natural frequencies are high enough to facilitate a practical computational solution. Results are presented for a baseline uncontrolled buffeting case and a delayed breakdown case in which the apex flap has been deflected 15 deg. The flap was found to be very effective in delaying the breakdown, increasing the location from 50%c to 94%c, which resulted in a 6% increase in lift coefficient and pitching moment. However, the integrated buffet loads and tip responses were roughly equivalent for the two cases.

Massey, Steven J.; Kandil, Osama A.

1998-01-01

295

Arsenic mobility in soils impacted by tailings at Zimapán, México  

NASA Astrophysics Data System (ADS)

The Zimapán mining zone, in Central México is one of the worldwide sites known for As contamination. For more than 20 years and until recently, As-rich groundwater, mainly due to mineralization in a limestone aquifer, was an important source of As exposure to the inhabitants. In addition, decades of ore processing have produced hazardous wastes (tailings), many of them settled in the town outskirts. Although mineralogical and chemical differences exist among the various deposits; every one has high As contents (up to several thousands mg/kg) and other toxic elements that may be released to the nearby soils. To assess As mobility in soils impacted by tailings, total and sequential fractionation determinations were performed in 120 superficial and 40 cm depth samples collected at various distances near three of the impoundments. Higher total As concentrations were measured in the dry (up to 51,534 mg/kg) with respect to the rainy season (up to 23,570 mg/kg) indicating the occurrence of As wash off by rain. Although concentrations were lower in the deep regarding the superficial samples at most sites, As contents reached several thousands mg/kg at 40 cm depth indicating also its vertical transport that may reach the shallow aquifer. Sequential extractions showed differences between soils impacted by highly oxidized (red) tailings and low oxidized (gray) deposits. Most of the As occurs in the Fe-Mn oxides fraction (up to 92%) followed by the organic matter and sulfides fraction (up to 52 %) in soils close to red tailings, while organic matter and sulfide fraction contain most of the As (up to 95%) in soil samples close to low-oxidized deposits. Arsenic proportion in the residual fraction increased with distance from oxidized tailings. Low pH values (from 2.0 to 2.5) in superficial soils revealed the influence of acid mine drainage at distances up to 40 m from the red deposit. In contrast, the lowest pH was 7.1 in soils impacted by low-oxidized deposits, reflecting the limestone environment. Arsenic airborne transport was evidenced by the presence of a total As concentration of 30,780 mg/kg in soils collected at 120 m in front of the tailings crossing a ravine. Although sequential extraction showed that most of the As is present in relatively low-mobility fractions, total As concentrations indicate that tailings impoundments constitute another source of environmental As exposure.

Aurora Armienta, M.; Resendiz, Isabel; Múgica, Violeta; Cruz, Olivia; Aguayo, Alejandra; Ceniceros, Nora

2014-05-01

296

14 CFR 23.481 - Tail down landing conditions.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Tail down landing conditions. ...AIRPLANES Structure Ground Loads § 23.481 Tail down landing conditions. (a) For a tail down landing, the airplane...before the maximum vertical load is...

2010-01-01

297

14 CFR 23.481 - Tail down landing conditions.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Tail down landing conditions. ...AIRPLANES Structure Ground Loads § 23.481 Tail down landing conditions. (a) For a tail down landing, the airplane...before the maximum vertical load is...

2009-01-01

298

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

PubMed

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 birds. Hence, these capabilities should have been present in the early Cretaceous, with incipient tail-fanning capacity in the earliest pygostylian birds. PMID:23690987

Pittman, Michael; Gatesy, Stephen M; Upchurch, Paul; Goswami, Anjali; Hutchinson, John R

2013-01-01

299

Cross-tail current - Resonant orbits  

NASA Technical Reports Server (NTRS)

A technique to generate self-consistent 1D current sheets is described. Groups of monoenergetic protons were followed in a modified Harris magnetic field. This sample current sheet is characterized by resonant quasi-adiabatic orbits. The magnetic moment of a quasi-adiabatic ion which is injected from outside a current sheet changes substantially during the orbit but returns to almost its initial value by the time the ion leaves. Several ion and electron groups were combined to produce a plasma sheet in which the charged particles carry the currents needed to generate the magnetic field in which the orbits were traced. An electric field also is required to maintain charge neutrality. Three distinct orbit types, one involving untrapped ions and two composed of trapped ions, were identified. Limitations associated with the use of a 1D model also were investigated; it can provide a good physical picture of an important component of the cross-tail current, but cannot adequately describe any region of the magnetotail in which the principal current sheet is separated from the plasma sheet boundary layer by a nearly isotropic outer position of the central plasma sheet.

Kaufmann, Richard L.; Lu, Chen

1993-01-01

300

Assessment of computational prediction of tail buffeting  

NASA Technical Reports Server (NTRS)

Assessments of the viability of computational methods and the computer resource requirements for the prediction of tail buffeting are made. Issues involved in the use of Euler and Navier-Stokes equations in modeling vortex-dominated and buffet flows are discussed and the requirement for sufficient grid density to allow accurate, converged calculations is stressed. Areas in need of basic fluid dynamics research are highlighted: vorticity convection, vortex breakdown, dynamic turbulence modeling for free shear layers, unsteady flow separation for moderately swept, rounded leading-edge wings, vortex flows about wings at high subsonic speeds. An estimate of the computer run time for a buffeting response calculation for a full span F-15 aircraft indicates that an improvement in computer and/or algorithm efficiency of three orders of magnitude is needed to enable routine use of such methods. Attention is also drawn to significant uncertainties in the estimates, in particular with regard to nonlinearities contained within the modeling and the question of the repeatability or randomness of buffeting response.

Edwards, John W.

1990-01-01

301

Key programmatic steps and activities for implementing the Uranium Mill Tailings Remedial Action Project. [UMTRA Project  

SciTech Connect

The Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA) was enacted based upon findings by Congress that uranium mill tailings located at active and inactive hazard to the public, and that protection of the public health, safety and welfare, and the regulations of interstate commerce, require that every reasonable effort be made to provide for the stabilization, disposal, and control in a safe and environmentally sound manner of such tailings in order to prevent or minimize radon diffusion into the environment and to prevent or minimize other environmental hazards from such tailings.'' A general understanding of the steps leading to elimination of the hazards associated with designated uranium mill tailings sites, and the parties involved in that effort, are presented in this document. A representative schedule is also presented in this document to show both program sequence and activity interdependence. Those activities that have the most potential to influence program duration, because of the significant amount of additional time that may be required, include identification and selection of a suitable site, field data collection delays due to weather, actual acquisition of the designated or alternate disposal site, construction delays due to weather, and site licensing. This document provides an understanding of the steps, the sequence, the parties involved, and a representative duration of activities leading to remedial action and cleanup at the designated inactive uranium mill tailings sites. 10 refs., 5 figs., 1 tab.

Not Available

1985-07-01

302

The Effect of Competitive Outcome and Task-Involving, Ego-Involving, and Cooperative Structures on the Psychological Well-Being of Individuals Engaged in a CoOrdination Task: A Self-Determination Approach  

Microsoft Academic Search

Differing task and motivational characteristics of the competitive setting (viz., task-involving\\/ego-involving climates, cooperative\\/individual, and win\\/loss competitive outcome) were explored in relation to need satisfaction and subjective well-being (SWB). Participants, one-on-one or in pairs, were required to participate in a physical co-ordination task. Results revealed participants exposed to a task-involving condition and those who worked in cooperation to report higher levels

Martyn Standage; Joan L. Duda; Anne Marte Pensgaard

2005-01-01

303

Switching axial progenitors from producing trunk to tail tissues in vertebrate embryos.  

PubMed

The vertebrate body is made by progressive addition of new tissue from progenitors at the posterior embryonic end. Axial extension involves different mechanisms that produce internal organs in the trunk but not in the tail. We show that Gdf11 signaling is a major coordinator of the trunk-to-tail transition. Without Gdf11 signaling, the switch from trunk to tail is significantly delayed, and its premature activation brings the hindlimbs and cloaca next to the forelimbs, leaving extremely short trunks. Gdf11 activity includes activation of Isl1 to promote formation of the hindlimbs and cloaca-associated mesoderm as the most posterior derivatives of lateral mesoderm progenitors. Gdf11 also coordinates reallocation of bipotent neuromesodermal progenitors from the anterior primitive streak to the tail bud, in part by reducing the retinoic acid available to the progenitors. Our findings provide a perspective to understand the evolution of the vertebrate body plan. PMID:23763947

Jurberg, Arnon Dias; Aires, Rita; Varela-Lasheras, Irma; Nóvoa, Ana; Mallo, Moisés

2013-06-10

304

Notochord-derived hedgehog is essential for tail regeneration in Xenopus tadpole  

PubMed Central

Background Appendage regeneration in amphibians is regulated by the combinatorial actions of signaling molecules. The requirement of molecules secreted from specific tissues is reflected by the observation that the whole process of regeneration can be inhibited if a certain tissue is removed from the amputated stump. Interestingly, urodeles and anurans show different tissue dependencies during tail regeneration. The spinal cord is essential for tail regeneration in urodele but not in anuran larva, whereas the notochord but not the spinal cord is essential for tail regeneration in anuran tadpoles. Sonic hedgehog is one of the signaling molecules responsible for such phenomenon in axolotl, as hedgehog signaling is essential for overall tail regeneration and sonic hedgehog is exclusively expressed in the spinal cord. In order to know whether hedgehog signaling is involved in the molecular mechanism underlying the inconsistent tissue dependency for tail regeneration between anurans and urodeles, we investigated expression of hedgehog signal-related genes in the regenerating tail of Xenopus tadpole and examined the effect of the hedgehog signal inhibitor, cyclopamine, on the tail regeneration. Results In Xenopus, sonic hedgehog is expressed exclusively in the notochord but not in the spinal cord of the regenerate. Overall regeneration was severely impaired in cyclopamine-treated tadpoles. Notochord maturation in the regenerate, including cell alignment and vacuolation, and myofiber formation were inhibited. Proliferation of spinal cord cells in the neural ampulla and of mesenchymal cells was also impaired. Conclusion As in the axolotl, hedgehog signaling is required for multiple steps in tail regeneration in the Xenopus tadpole, although the location of the Shh source is quite different between the two species. This difference in Shh localization is the likely basis for the differing tissue requirement for tail regeneration between urodeles and anurans.

2014-01-01

305

Ultrastructural aspects of rat tail tendon sheaths.  

PubMed Central

An investigation was carried out on the sheaths which envelop rat tail tendons. The samples were processed for observation by light and electron microscopy. In the case of electron microscopy, thin sections of specimens embedded in epoxy resin and replicas of freeze etched samples were used. On the basis of histological and ultrastructural observations, four distinct connective tissue sheaths have been detected. The paratendineum is a thick fibrous sheath that covers externally the four groups of tendons arranged around the vertebrae of the tail; the epitendineum is a distinct fibrous sheath surrounding each tendon group; the peritendineum is composed of concentric cellular laminae enveloping each tendon; lastly, the endotendineum is made up of one cellular lamella which adheres to the fibres of the tendon, projecting trabeculae between the individual tendon fascicles. In the para- and epitendineum, thick bundles of collagen fibrils, running parallel to the fibres of the tendon, were visible. The collagen fibrils had a wide variability of diameters (from 35 to 220 nm) and, when examined in replica, their microfibrillar arrangement appeared to be straight. In the peri- and endotendineum, thin bundles of collagen fibrils were visible between the cellular laminae, parallel to the main axis of the tendon. Among these collagen bundles, elastic fibres and numerous glycoproteins containing microfibril-like filaments were visible. The collagen fibrils were small and of uniform diameter (50 nm) and, when observed on replica, showed a helicoidal microfibrillar arrangement. The cell layers of the peri- and endotendineum were made up of flattened fibroblasts which were connected by specialised junctions and which contained numerous micropinocytotic vesicles. A thin layer of granular electron-dense material, with ultrastructural characteristics similar to those of a basement membrane, was visible on the surface of the most external cellular layer of the peritendineum and on the outer surface of the cellular lamella of the endotendineum. Due to their morphological characteristics it is supposed that the four tendon sheaths are involved in different and special functions. Moreover, collagen Type I and collagen Type III, demonstrated by means of immunofluorescence techniques in previous investigations, show respectively a close similarity in distribution to the thick collagen fibrils, with a straight microfibrillar arrangement, of the two external sheaths, and to the thin collagen fibrils, with a helicoidal microfibrillar arrangement, of the two internal sheaths. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9

Strocchi, R; Leonardi, L; Guizzardi, S; Marchini, M; Ruggeri, A

1985-01-01

306

Supersonic aerodynamic characteristics of canard, tailless, and aft-tail configurations for 2 wing planforms  

NASA Technical Reports Server (NTRS)

Aerodynamic characteristics of canard, tailless, and aft tail configurations were compared in tests on a general research model (generic fuselage without canopy, inlets, or vertical tails) at Mach 1.60 and 2.00 in the Langley Unitary Plan Wind Tunnel. Two uncambered wing planforms (trapezoidal with 44 deg leading edge sweep and delta with 60 deg leading edge sweep) were tested for each configuration. The relative merits of the configurations were also determined theoretically, to evaluate the capabilities of a linear theory code for such analyses. The canard and aft tail configurations have similar measured values for lift curve slope, maximum lift drag ratio, and zero lift drag. The stability decrease as Mach number increases is greatest for the tailless configuration and least for the canard configuration. Because of very limited accuracy in predicting the aerodynamic parameter increments between configurations, the linear theory code is not adequate for determining the relative merits of canard, tailless, and aft tail configurations.

Covell, P. F.

1985-01-01

307

Artificial inoculation-perspectives in tailings phytostabilization.  

PubMed

Intensive mining and processing activities worldwide resulted in the generation of huge amounts of waste (tailings), generally characterized as toxic, radioactive, and/or hazardous. The exposure potential and, hence, the risk posed by such wastes is enhanced by a general lack of vegetation. Phytostabilization has proven to be efficient in reducing this risk. However, establishing vegetation on tailing dumps may be expensive due to the intensive use of amendments and chemical fertilizers. In this article, investigations on artificial inoculation of mine tailings with bacterial strains as a means to improve the development of vegetative covers and reduce application cost by eliminating chemical fertilization are presented and discussed. The development of plants and microbial communities from tailings, as well as the impact of inoculation on metal uptake in plants, were studied. Experiments were carried out in greenhouse using two types of mine tailings (phosphogypsum and sulphidic tailings) from the Romanian Black Sea coast. Indigenous herbaceous plants were cultivated on tailings with the addition of chemical fertilizers versus bacterial inoculation. After a 6-month experimental period, excellent plant growth, which is associated with a rich microbial community, was observed in all inoculated treatments, in contrast with poor plant growth and microbiota from the chemical fertilization treatments alone. Additionally, artificial inoculation improved plant resistance to heavy metals by reducing the uptake of some toxic metals. Once a rich microbial community is established, inoculation may be discontinued. Based on these results, efficient and cost-effective phytostabilization schemes can be proposed. PMID:15224772

Petrisor, Ioana G; Dobrota, Smaranda; Komnitsas, Kostas; Lazar, Ioan; Kuperberg, J Michael; Serban, Mihai

2004-01-01

308

Strengthening of solidified dilute tailings slurry  

SciTech Connect

Tailings produced during mineral processing contain up to 75% or more water and are pumped into settling ponds for disposal. They often become a pollution source due to acid generation. While tailings have been used in underground backfill, the use is very limited at present. This paper presents research results on direct solidification and strengthening of the dilute tailings slurry without dewatering. Two types of tailings were tested at water/binder ratios of up to 4.5 using a special high-water binder. Adequate strength was achieved by solidifying the tailings as is. To further improve the strength, sands and fly ash were used as reinforcement materials or partial replacement of the binder. For oil sands tailings, the 3-day strength was increased by up to 114% with 10--15% additives. For hard rock tailings, up to 30% strength gain was achieved with 15% fly ash addition, and the strength was increased by up to 36% at 10% binder replacement and no strength reduction was observed at 20--25% replacement. These results indicate that higher strength can be achieved with the proper amount of additives and that the backfill process can be simplified and the operation cost reduced.

Zou, D.H.; Li, L.P. [Dalhousie Univ., Halifax, NS (Canada). Dept. Mining and Metallurgical Engineering] [Dalhousie Univ., Halifax, NS (Canada). Dept. Mining and Metallurgical Engineering

1999-01-01

309

The tidal tails of globular cluster Palomar 5 based on the neural networks method  

NASA Astrophysics Data System (ADS)

The sixth Data Release (DR6) of the Sloan Digital Sky Survey (SDSS) provides more photometric regions, new features and more accurate data around globular cluster Palomar 5. A new method, Back Propagation Neural Network (BPNN), is used to estimate the cluster membership probability in order to detect its tidal tails. Cluster and field stars, used for training the networks, are extracted over a 40 × 20 deg2 field by color-magnitude diagrams (CMDs). The best BPNNs with two hidden layers and a Levenberg-Marquardt (LM) training algorithm are determined by the chosen cluster and field samples. The membership probabilities of stars in the whole field are obtained with the BPNNs, and contour maps of the probability distribution show that a tail extends 5.42° to the north of the cluster and another tail extends 3.77° to the south. The tails are similar to those detected by Odenkirchen et al., but no more debris from the cluster is found to the northeast in the sky. The radial density profiles are investigated both along the tails and near the cluster center. Quite a few substructures are discovered in the tails. The number density profile of the cluster is fitted with the King model and the tidal radius is determined as 14.28'. However, the King model cannot fit the observed profile at the outer regions (R > 8') because of the tidal tails generated by the tidal force. Luminosity functions of the cluster and the tidal tails are calculated, which confirm that the tails originate from Palomar 5.

Zou, Hu; Wu, Zhen-Yu; Ma, Jun; Zhou, Xu

2009-10-01

310

Analysis of the OspE determinants involved in binding of factor H and OspE-targeting antibodies elicited during Borrelia burgdorferi infection in mice.  

PubMed

Immune evasion by Lyme spirochetes is a multifactorial process involving numerous mechanisms. The OspE protein family undergoes antigenic variation during infection and binds factor H (fH) and possibly FHL-1/reconectin. In Borrelia burgdorferi B31MI, the OspE family consists of three paralogs: BBL39 (ErpA), BBP38, and BBN38 (ErpP). BBL39 and BBP38 are identical and therefore are referred to here as BBL39. The goals of this study were to assess the specificity of the antibody (Ab) response to the OspE paralogs and to identify the domains or determinants of OspE that are required for the binding of fH and OspE-targeting Abs that develop during infection. Here we demonstrate that at least some of the anti-OspE Abs produced during infection are paralog specific and that Ab binding requires conformational determinants whose formation requires both the N- and C-terminal domains of OspE. The binding of fH to OspE was also found to be dependent on conformational determinants. It is also demonstrated here that all of the OspE paralogs expressed by B. burgdorferi B31MI are capable of binding fH. The binding of fH to members of the OspF protein family was also assessed. In contrast to an earlier report, no binding of BBO39 or BBR42 to human fH was detected. Lastly, a series of competitive binding enzyme-linked immunosorbent assay analyses, designed to determine if fH and infection serum Abs bind to the same sites on OspE, revealed that these ligands interact with different regions of OspE. PMID:12761144

Metts, Michael S; McDowell, John V; Theisen, Michael; Hansen, Paul Robert; Marconi, Richard Thomas

2003-06-01

311

Effects of sewage sludge on solution chemistry and plant uptake of Cu in sulphide mine tailings at different weathering stages  

Microsoft Academic Search

This climate chamber experiment examines the effects of sewage sludge (SS) on sulphide mine tailings from the Aitik Cu mine in northern Sweden. The effects of SS were determined from Cu in solution and Cu uptake and growth of plants on tailings showing 3 different degrees of weathering. Possible relationships between Cu content in plants and Cu in solution measured

Lovisa Stjernman Forsberg; Dan Berggren Kleja; Maria Greger; Stig Ledin

2009-01-01

312

Vibrations of the earth's magnetic tail  

NASA Technical Reports Server (NTRS)

The natural vibration period of the tail (regarded as bundle of magnetic line-of-force strings) and the characteristic time of recurrence of magnetospheric substorms are of the same order, suggesting the possibility of a relation between these phenomena. A model of the tail in the form of a plasma cylinder whose free boundary is immersed in the interplanetary plasma is examined. The nature of the natural oscillations of the tail excited by variations of the solar wind pressure is studied in this model. These vibrations have a total energy of approximately 10 to the 22nd power erg, which is sufficient to generate magnetospheric substorms.

Yershkovich, A. I.; Nusinov, A. A.

1974-01-01

313

The Use of One Versus Two-Tailed Tests to Evaluate Prevention Programs  

Microsoft Academic Search

Investigators have used both one- and two-tailed tests to determine the significance of findings yielded by program evaluations. While the literature that addresses the appropriate use of each type of significance test should be used is historically inconsistent, almost all authorities now agree that one-tailed tests are rarely (if ever) appropriate. A review of 85 published evaluations of school-based drug

Chris Ringwalt; M. J. Paschall; Dennis Gorman; James Derzon; Alan Kinlaw

2011-01-01

314

Magnetic reconnection in the magnetotail current sheet for varying cross-tail magnetic field  

Microsoft Academic Search

Three-dimensional magnetic reconnection is investigated by means of resistive MHD simulations on the basis of magnetotail models with various magnitudes of the average net cross-tail magnetic field component. Typical quantities such as parallel electric fields, reconnected flux and flow velocities are studied to determine the influence of increasing B(y) values on the fast dynamical evolution of the magnetotail. A cross-tail

Michael Hesse; Joachim Birn

1990-01-01

315

Survival of white-tailed deer in an intensively farmed region of Minnesota  

Microsoft Academic Search

Survival and cause-specific mortality of white-tailed deer (Odocoileus virginianus) have been well documented in forested habitat, but limited information has been collected in intensively farmed regions. The objectives of this study were to determine survival and cause-specific mortality of neonate, fawn female, and adult female white-tailed deer in an intensively farmed (>80% land cover) region of Minnesota. We captured and

Todd J. Brinkman; Jonathan A. Jenks; Christopher S. DePerno; Brian S. Haroldson; Robert G. Osborn

2004-01-01

316

Flight investigation of the effect of tail boom strakes on helicopter directional control  

NASA Technical Reports Server (NTRS)

A joint U.S. Army/NASA flight investigation was conducted utilizing a single-rotor helicopter to determine the effectiveness of horizontally mounted tail boom strakes on directional controllability and tail rotor power during low-speed, crosswind operating conditions. Three configurations were investigated: (1) baseline (strakes off), (2) single strake (strake at upper shoulder on port side of boom), and (3) double strake (upper strake plus a lower strake on same side of boom). The strakes were employed as a means to separate airflow over the tail boom and change fuselage yawing moments in a direction to improve the yaw control margin and reduce tail rotor power. Crosswind data were obtained in 5-knot increments of airspeed from 0 to 35 knots and in 30 deg increments of wind azimuth from 0 deg to 330 deg. At the most critical wind azimuth and airspeed in terms of tail rotor power, the strakes improved the pedal margin by 6 percent of total travel and reduced tail rotor power required by 17 percent. The increase in yaw control and reduction in tail rotor power offered by the strakes can expand the helicopter operating envelope in terms of gross weight and altitude capability. The strakes did not affect the flying qualities of the vehicle at airspeeds between 35 and 100 knots.

Kelly, Henry L.; Crowell, Cynthia A.; Yenni, Kenneth R.; Lance, Michael B.

1993-01-01

317

Sequential determination of metabolites involved in the biosynthesis of aromatic amino acids after ultrasound-assisted extraction from plants and reverse LC separation.  

PubMed

A dual method is proposed for the determination of metabolites involved in the shikimate pathway which are biomarkers of the effects of glyphosate action on plants exposed to this herbicide. Extraction of the target metabolites (phenylalanine, tryptophan, tyrosine and shikimic acid) from a wheat model plant was accelerated by ultrasound energy. After centrifugation and micro-filtration, 1 ?L of extract was injected into the chromatograph in an isocratic regime for 4 min to determine shikimate by absorption at 254 nm. In the mean time, a 130 ?L aliquot of extract was subjected to derivatization with o-phthaldialdehyde and 2-mercaptoethanol for 1 min, the reaction stopped and 1 ?L of the solution chromatographied in a gradient regime prior to laser-induced fluorescence detection of the derivatized amino acids. The characterization of the dual method provided limits of detection around 0.03 ?g mL(-1) for the aromatic amino acids and 1.52 ?g mL(-1) for shikimate, whereas the limits of quantitation ranged between 0.084 and 0.093 ?g mL(-1) for amino acids and was of 4.56 ?g mL(-1) for shikimate. The suitability of the method was checked by application to Triticum aestivum (wheat) plants grown under controlled conditions, sprayed with different doses of glyphosate and collected at different times after exposition to the herbicide. PMID:23598041

Alcaide-Molina, Miguel; Priego-Capote, Feliciano; Luque de Castro, María Dolores

2013-02-15

318

Sexual performance of rams sequentially exposed to short-tailed and fat-tailed ewes.  

PubMed

The objective of the study was to compare sexual performance of pure and crossbred rams, and to evaluate whether prior exposure of rams to short-tailed females would enhance their mating ability when later exposed to fat-tailed females. Twenty-two virgin, yearling Awassi (A; n = 7), F(1) Charollais x Awassi (CA; n = 7) and F(1) Romanov x Awassi (RA; n = 8) rams were subjected to sexual performance tests on six 20-min occasions. Each ram was individually exposed to two short-tailed oestrous ewes for three 20-min occasions on three consecutive days. Following 1 day of rest, the same 3-day procedure was repeated for each ram with fat-tailed ewes. Leg kicking bout frequency increased in CA and RA rams and decreased in A rams, when they were exposed to fat-tailed compared with short-tailed ewes. No differences in anogenital sniffing were observed among rams exposed to either short-tailed or fat-tailed ewes. However, greater (p < 0.001) anogenital sniffing bouts were recorded, when rams were exposed to short-tailed females. Upon exposure to fat-tailed ewes, CA and RA rams experienced a marked increase in mounting frequency compared with a slight increase in mounting of A rams (p < 0.001). The ability of Awassi rams to raise the fat tail of Awassi ewes was greater (p < 0.001) than CA and RA rams. Mating was improved in A while declining in CA and RA, when they were exposed to fat-tailed compared with short-tailed ewes (p < 0.001). Based on the results of the current study, it seems that all yearling rams were capable of mating with short-tailed ewes, whereas only Awassi rams managed to mate with fat-tailed ewes. It appears that brief exposures of yearling crossbred rams to short-tailed ewes do not improve their mating ability when later exposed to fat-tailed ewes. PMID:18363610

Kridli, R T; Abdullah, A Y; Shaker, M Momani; Mahmoud, K Z

2008-08-01

319

Approximation of Pearson Type IV Tail Probabilities.  

National Technical Information Service (NTIS)

Simple approximating functions for tail probabilities of the Pearson Type IV distribution are obtained by using the B sub n transformations and by truncating the continued fraction expansion. The behavior of these approximations is then investigated for v...

W. A. Woodward

1975-01-01

320

Engineering Assessment of Inactive Uranium Mill Tailings.  

National Technical Information Service (NTIS)

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...

1981-01-01

321

Tree Growth Studies on Uranium Mill Tailings.  

National Technical Information Service (NTIS)

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 wit...

D. R. Murray M. Turcotte

1982-01-01

322

Cost of Decommissioning Uranium Mill Tailings.  

National Technical Information Service (NTIS)

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 als...

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

1986-01-01

323

Lifting-surface-theory aspect-ratio corrections to the lift and hinge-moment parameters for full-span elevators on horizontal tail surfaces  

NASA Technical Reports Server (NTRS)

A limited number of lifting-surface-theory solutions for wings with chordwise loadings resulting from angle of attack, parabolic-ac camber, and flap deflection are now available. These solutions were studied with the purpose of determining methods of extrapolating the results in such a way that they could be used to determine lifting-surface-theory values of the aspect-ratio corrections to the lift and hinge-moment parameters for both angle-of-attack and flap-deflection-type loading that could be used to predict the characteristics of horizontal tail surfaces from section data with sufficient accuracy for engineering purposes. Such a method was devised for horizontal tail surfaces with full-span elevators. In spite of the fact that the theory involved is rather complex, the method is simple to apply and may be applied without any knowledge of lifting-surface theory. A comparison of experimental finite-span and section value and of the estimated values of the lift and hinge-moment parameters for three horizontal tail surfaces was made to provide an experimental verification of the method suggested. (author)

Swanson, Robert S; Crandall, Stewart M

1948-01-01

324

The Tail of KdsC  

PubMed Central

The phosphatase KdsC cleaves 3-deoxy-d-manno-octulosonate 8-phosphate to generate a molecule of inorganic phosphate and Kdo. Kdo is an essential component of the lipopolysaccharide envelope in Gram-negative bacteria. Because lipopolysaccharide is an important determinant of bacterial resistance and toxicity, KdsC is a potential target for novel antibacterial agents. KdsC belongs to the broad haloacid dehalogenase superfamily. In haloacid dehalogenase superfamily enzymes, substrate specificity and catalytic efficiency are generally dictated by a fold feature called the cap domain. It is therefore not clear why KdsC, which lacks a cap domain, is catalytically efficient and highly specific to 3-deoxy-d-manno-octulosonate 8-phosphate. Here, we present a set of seven structures of tetrameric Escherichia coli KdsC (ranging from 1.4 to 3.06 Å in resolution) that model different intermediate states in its catalytic mechanism. A crystal structure of product-bound E. coli KdsC shows how the interface between adjacent monomers defines the active site pocket. Kdo is engaged in a network of polar and nonpolar interactions with residues at this interface, which explains substrate specificity. Furthermore, this structural and kinetic analysis strongly suggests that the binding of the flexible C-terminal region (tail) to the active site makes KdsC catalytically efficient by facilitating product release.

Biswas, Tapan; Yi, Li; Aggarwal, Parag; Wu, Jing; Rubin, John R.; Stuckey, Jeanne A.; Woodard, Ronald W.; Tsodikov, Oleg V.

2009-01-01

325

ATS Claus tail gas cleanup at Table Rock Tail Gas Plant. [Ammonium thiosulfate  

SciTech Connect

This paper describes the Table Rock Processing Plant which consists of four major parts: the treating plant, the dew point control plant, a sulfur plant, and the tail gas plant. The tail gas plant uses the ammonium thiosulfate process to convert about 4 tons per day of sulfur to 60 tons per day of ATS. The brief discussion is presented under headings: the tail gas process; chemistry (chemical reaction and equipment); plant performance. 7 refs.

White, S.P.

1981-01-01

326

Radial tail resolution in the SELEX RICH  

Microsoft Academic Search

We use a seven million event data sample of 600GeV\\/c single-track pion events, where the pion track is reconstructed upstream and downstream of the SELEX RICH. We build the RICH ring radius histogram distribution and count the tail events that fall outside 5?, giving a fraction of 4×10-5 events outside the Gaussian tails. This control of events establishes the ability

A. Morelos; J. Mata; P. S. Cooper; J. Engelfried; J. L. Aguilera-Servin

2005-01-01

327

Head-tail instability at Tevatron  

SciTech Connect

Tevatron performance suffers from a coherent transverse instability. Experimental studies and theoretical examination allow identifying the instability as a weak head-tail, driven by the short-range wake fields in presence of the space charge. Growth rates and coherent tune shifts are measured at injection of single high-intensity proton bunches using a fast strip-line pickup. Landau damping through the octupole-generated betatron tune spread for all of unstable head-tail modes has been demonstrated.

Petr M Ivanov et al.

2003-05-27

328

Energetic ion regimes in the deep geomagnetic tail - ISEE-3  

NASA Technical Reports Server (NTRS)

Bame et al. (1983) have given plasma measurements for two 12-hour intervals and have identified the plasma regions observed during the January 1-March 30, 1983 traversal by the ISEE-3 spacecraft of a previously unexplored part of the distant geomagnetic tail. Attention is presently given to the 35 keV-1.6 MeV energetic ion and magnetic field measurements made by ISEE-3, relating them to the plasma measurements. The plasma sheet is found to be a region of energetic ion enhanced fluxes, with unidirectionally tailored flow. A characterization accounting for these characteristics involves occurrence of reconnection at a neutral line that lies earthward of the spacecraft.

Cowley, S. W. H.; Hynds, R. J.; Richardson, G.; Daly, P. W.; Wenzel, K.-P.; Slavin, J. A.; Tsurutani, B. T.

1984-01-01

329

Engineering assessment of inactive uranium mill tailings: Phillips/United Nuclear site, Ambrosia Lake, New Mexico  

SciTech Connect

Ford, Bacon and Davis Utah, Inc., has reevaluated the Phillips/United Nuclear site in order to revise the December 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Ambrosia Lake, New Mexico. 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 2.6 million dry tons of tailings at the Phillips/United Nuclear site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment 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 four options range from about $21,500,000 for stabilization in-place, to about $45,200,000 for disposal at a distance of about 15 mi. Three principal alternatives for the reprocessing of the Phillips/United Nuclear 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 $87/lb of U/sub 3/O/sub 8/ by either heap leach or conventional plant process. The spot market price for uranium was $25/lb early in 1981. Reprocessing the Phillips/United Nuclear tailings for uranium recovery does not appear to be economically attractive under present or foreseeable market conditions.

none,

1981-10-01

330

Engineering assessment of inactive uranium mill tailings, Shiprock site, Shiprock, New Mexico  

SciTech Connect

Ford, Bacon and Davis Utah Inc. has reevaluated the Shiprock site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Shiprock, New Mexico. 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 1.5 million dry tons of tailings at the Shiprock site constitutes the most significant environental impact, although windblown tailings and external gamma radiation also are factors. The eight alternative actions presented in this engineering assessment range from millsite 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 $13,400,000 for stabilization in place to about $37,900,000 for disposal at a distance of about 16 miles. Three principal alternatives for the reprocessing of the Shiprock 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 $230/lb by heap leach and $250/lb by conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery is not economically attractive.

Not Available

1981-07-01

331

Engineering assessment of inactive uranium mill tailings: Maybell Site, Maybell, Colorado  

SciTech Connect

Ford, Bacon and Davis Utah Inc. has reevaluated the Maybell site in order to revise the October 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Maybell, 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 2.6 million dry tons of tailings at the Maybell site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The two alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material (Option I), to disposal of the tailings in a nearby open pit mine and decontamination of the tailings site (Option II). Cost estimates for the two options are about $11,700,000 for stabilization in-place and about $22,700,000 for disposal within a distance of 2 mi. Three principal alternatives for the reprocessing of the Maybell 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 $125 and $165/lb of U/sub 3/O/sub 8/ by heap leach and conventional plant processes, respectively. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery is not economically attractive at present.

none,

1981-09-01

332

The Effects of Solute Breakthrough Curve Tail Truncation on Residence Time Estimates and Mass Recovery  

NASA Astrophysics Data System (ADS)

Solute transport and hydrologic retention strongly affect biogeochemical processes that are critical to stream ecosystems. Tracer injections are used to characterize solute transport and storage in stream reaches, but the range of processes accurately resolved using this approach is not clear. The solute residence time distribution (RTD) depends on both in-stream mixing and exchange with the hyporheic zone. For shorter residence times, in-stream breakthrough curves (BTCs) can be modeled well with the classical advection-dispersion equation, whereas longer RTDs produce highly skewed in-stream BTCs for which traditional solute models are inappropriate. Observed BTCs have most commonly been modeled with in-stream advection-dispersion plus an exponential RTD, but process-based models suggest that hyporheic retention extends to much longer times and a power-law RTD is more appropriate. We synthesized results from a variety of tracer-injection studies to investigate how experimental design and tracer sensitivity influence the interpretation of tailing behavior and RTDs. We found that BTC tails are often not well observed in stream tracer experiments. The two main reasons for this are: 1) experimental truncation, which occurs when sampling ends before all tracer mass reaches the sampling location, and 2) sensitivity truncation, when tracer concentrations in the tail are too low to be detected reliably above background levels. Continuous Time Random Walk (CTRW) theory was used to determine the effects of tail truncation on tracer mass recovery and tailing behavior. Tail truncation due to both experimental and sensitivity truncation decreased mass recovery and obscured assessment of BTC tailing. Failure to consider tail truncation leads to underestimation of the retention of solutes in the streambed and subsurface (i.e., transient storage). Based on these findings, we propose criteria for stream tracer experiments to minimize tail truncation and improve inverse modeling of solute transport.

Drummond, J. D.; Covino, T. P.; Aubeneau, A. F.; Patil, S.; Leong, D. N.; Ran, L.; Packman, A. I.; Schumer, R.

2010-12-01

333

Engineering assessment of inactive uranium mill tailings: Slick Rock sites, Slick Rock, Colorado  

SciTech Connect

Ford, Bacon and Davis Utah, Inc., has reevaluated the Slick Rock sites in order to revise the October 1977 engineering radioactive uranium mill tailings at Slick Rock, 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 387,000 tons of tailings at the Slick Rock sites constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The five alternative actions presented in this engineering assessment include millsite decontamination with the addition of 3 m of stabilization cover material, consolidation of the piles, and removal of the tailings to remote disposal sites and decontamination of the tailings sites. Cost estimates for the five options range from about $6,800,000 for stabilization in-place, to about $11,000,000 for disposal at a distance of about 6.5 mi. Three principal alternatives for the reprocessing of the Slick Rock 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 over $800/lb of U/sub 3/O/sub 8/ whether by conventional or heap leach plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery is not economically attractive at present, nor for the foreseeable future.

none,

1981-09-01

334

Engineering assessment of inactive uranium mill tailings: Mexican Hat site, Mexican Hat, Utah. Summary  

SciTech Connect

Ford, Bacon and Davis Utah Inc. has reevaluated the Mexican Hat site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Mexican Hat, Utah. 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 investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 2.2 million tons of tailings at the Mexican Hat site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment 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 four options range from about $15,200,000 for stabilization in place, to about $45,500,000 for disposal at a distance of about 16 mi. Three principal alternatives for the reprocessing of the Mexican Hat tailings were examined: (a) 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 $115/lb of U/sub 3/O/sub 8/ whether by heap leach or conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Reprocessing the Mexican Hat tailings for uranium recovery is not economically attractive under present conditions.

none,

1981-09-01

335

Engineering assessment of inactive uranium mill tailings: Mexican Hat Site, Mexican Hat, Utah  

SciTech Connect

Ford, Bacon and Davis Utah Inc. has reevaluated the Mexican Hat site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Mexican Hat, Utah. 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 2.2 million tons of tailings at the Mexican Hat site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment 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 four options range from about $15,200,000 for stabilization in place, to about $45,500,000 for disposal at a distance of about 16 mi. Three principal alternatives for the reprocessing of the Mexican Hat 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 $115/lb of U/sub 3/O/sub 8/ whether by heap leach or conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Reprocessing the Mexican Hat tailings for uranium recovery is not economically attractive under present conditions.

none,

1981-09-01

336

Anomalous Urbach tail in GaAs  

NASA Astrophysics Data System (ADS)

The Urbach tail in crystalline GaAs and Si due to thermal vibration is evaluated in the temperature range 0-810 K. Recent experiments suggest that there is no thermally induced Urbach tail in undoped GaAs. This is most unexpected since thermally induced tails at the absorption edge having the Urbach form and widths E0(T) linear in T are observed in a wide range of crystalline and amorphous semiconductors. Clear understanding of the tail is important in device applications. In our calculations, we obtain an absorption tail having a simple exponential energy dependence (Urbach form) in GaAs at all temperatures with E0(T) proportional to T. However, due to a very weak electron-phonon interaction, the magnitude of E0(T) is unusually small, much smaller than the temperature independent, structurally induced component E0~=10 meV. As a test of the method, the tail is similarly evaluated in Si providing an E0(T) value in agreement with experiment.

Greeff, C. W.; Glyde, H. R.

1995-01-01

337

The sodium tail of the Moon  

NASA Astrophysics Data System (ADS)

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.

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

2009-12-01

338

An acceleration mechanism for cometary plasma tails  

NASA Technical Reports Server (NTRS)

Cometary plasma tail formation by the interaction between the solar wind plasma flow and the plasma at the head of the coma is discussed using the unipolar electric generation theory. The plasma in the 'plasma tail' is almost directly accelerated from the cometary ionopause along the sun-nucleus line where the tail current flows. For steady state solar wind conditions, the cometary 'plasma tail' velocity distribution is obtained self-consistently. The solution of a kinetic equation gives the velocity of the cometary plasma as a function of the cometary tail position. The characteristic length is 3 x 10 to the 6th km when the plasma density near the nucleus of the comet is 10 to the 6th/cu cm and the component of the interplanetary magnetic field perpendicular to the solar wind flow is 3 nT. The tailward cometary plasma is finally accelerated to the speed of the solar wind. The theory is compared with the observational plasma velocities in the tails of comet Bennett (1970II) and Comet Halley (1985).

Minami, S.; White, R. S.

1986-01-01

339

Snapshot of haloarchaeal tailed virus genomes  

PubMed Central

The complete genome sequences of archaeal tailed viruses are currently highly underrepresented in sequence databases. Here, we report the genomic sequences of 10 new tailed viruses infecting different haloarchaeal hosts. Among these, only two viral genomes are closely related to each other and to previously described haloviruses HF1 and HF2. The approximately 760 kb of new genomic sequences in total shows no matches to CRISPR/Cas spacer sequences in haloarchaeal host genomes. Despite their high divergence, we were able to identify virion structural and assembly genes as well as genes coding for DNA and RNA metabolic functions. Interestingly, we identified many genes and genomic features that are shared with tailed bacteriophages, consistent with the hypothesis that haloarchaeal and bacterial tailed viruses share common ancestry, and that a viral lineage containing archaeal viruses, bacteriophages and eukaryotic viruses predates the division of the three major domains of non-viral life. However, as in tailed viruses in general and in haloarchaeal tailed viruses in particular, there are still a considerable number of predicted genes of unknown function.

Sencilo, Ana; Jacobs-Sera, Deborah; Russell, Daniel A.; Ko, Ching-Chung; Bowman, Charles A.; Atanasova, Nina S.; Osterlund, Eija; Oksanen, Hanna M.; Bamford, Dennis H.; Hatfull, Graham F.; Roine, Elina; Hendrix, Roger W.

2013-01-01

340

Field investigation of evaporation from freshwater tailings  

SciTech Connect

Safe and economical storage of tailings is now a major consideration in the operation of many mining operations. Tailings in slurried form, particularly if they have a significant clay content, can take a very long time to consolidate under the action of self-weight consolidation alone. However, if the operation is located in an area of high potential evaporation, this can be used to accelerate the rate of tailings densification. This paper presents a study of the evaporation behavior of a clayey tailings slurry deposited into an evaporation pond in the southwest of Western Australia. Over a six-month period, the rate of evaporation from the tailings surface was monitored using the Bowen Ratio method and the microlysimeter method. This was compared with the evaporation from a Class A pan located nearby. The tailings underwent very significant cracking as drying proceeded, and it was found that these cracks had a significant influence on the overall rate of evaporation once the top surface of the deposit started to desaturate. A large strain consolidation model was used to model the behavior, and the algorithm used in this model to include the effects of evaporation is shown to provide a reasonable prediction of the observed evaporation behavior.

Fujiyasu, Yoshimasa; Fahey, M.; Newson, T.

2000-06-01

341

The Sodium Tail of the Moon  

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

342

The Tail Movement of Bull Spermatozoa  

PubMed Central

Detailed observations of the tail movement of non-rotating and rotating bull spermatozoa have been carried out. For rotating sperm a helical tail wave was found with a ratio of the amplitudes of the two perpendicular components of approximately 3 to 1. For both types of cells the variation of the amplitude and the phase shift of the wave as it travels from the proximal to the distal part are reported. Model calculations indicate that the stiffness of the tail originates in the fibrous sheath, which has a Young's modulus of 3 × 107 dynes/cm2. Active contractile elements distributed continuously along the tail are found necessary to maintain the amplitude of the tail wave against damping by the fluid drag. If the longitudinal fibers are identified with the contractile elements the maximum tension to be developed by these fibers is 4 × 106 dynes/cm2. The energy dissipated by the “active” part of the tail wave is at least approximately 70 percent of the total dissipation. ImagesFigure 1

Rikmenspoel, Robert

1965-01-01

343

Double chromodomains cooperate to recognize the methylated histone H3 tail  

SciTech Connect

Chromodomains are modules implicated in the recognition of lysine-methylated histone tails and nucleic acids. CHD (for chromo-ATPase/helicase-DNA-binding) proteins regulate ATP-dependent nucleosome assembly and mobilization through their conserved double chromodomains and SWI2/SNF2 helicase/ATPase domain. The Drosophila CHD1 localizes to the interbands and puffs of the polytene chromosomes, which are classic sites of transcriptional activity. Other CHD isoforms (CHD3/4 or Mi-2) are important for nucleosome remodelling in histone deacetylase complexes. Deletion of chromodomains impairs nucleosome binding and remodelling by CHD proteins. Here we describe the structure of the tandem arrangement of the human CHD1 chromodomains, and its interactions with histone tails. Unlike HP1 and Polycomb proteins that use single chromodomains to bind to their respective methylated histone H3 tails, the two chromodomains of CHD1 cooperate to interact with one methylated H3 tail. We show that the human CHD1 double chromodomains target the lysine 4-methylated histone H3 tail (H3K4me), a hallmark of active chromatin. Methylammonium recognition involves two aromatic residues, not the three-residue aromatic cage used by chromodomains of HP1 and Polycomb proteins. Furthermore, unique inserts within chromodomain 1 of CHD1 block the expected site of H3 tail binding seen in HP1 and Polycomb, instead directing H3 binding to a groove at the inter-chromodomain junction.

Flanagan, John F.; Mi, Li-Zhi; Chruszcz, Maksymilian; Cymborowski, Marcin; Clines, Katrina L.; Kim, Youngchang; Minor, Wladek; Rastinejad, Fraydoon; Khorasanizadeh, Sepideh (ANL/SBC); (UV)

2010-07-19

344

Summary of the engineering assessment of inactive uranium mill tailings, Spook Site, Converse County, Wyoming  

SciTech Connect

Ford, Bacon, Davis Utah Inc. has reevaluated the Spook site in order to revise the December 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings 48 mi northeast of Casper, in Converse County, Wyoming. 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 187,000 tons of tailings at the Spook site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors.

Not Available

1981-10-01

345

Engineering assessment of inactive uranium mill tailings, Tuba City site, Tuba City, Arizona  

SciTech Connect

Ford, Bacon and Davis Utah Inc. has reevaluated the Tuba City site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Tuba City, Arizona. 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 0.8 million tons of tailings at the Tuba City site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors.

Not Available

1981-09-01

346

MESSENGER Observations of Extreme Loading and Unloading of Mercury's Magnetic Tail  

NASA Technical Reports Server (NTRS)

During MESSENGER's third flyby of Mercury, the magnetic field in the planet's magnetotail increased by factors of 2 to 3.5 over intervals of 2 to 3 min. Magnetospheric substorms at Earth are powered by similar tail loading, but the amplitude is approx.10 times less and typical durations are approx.1 hour. The extreme tail loading observed at Mercury implies that the relative intensity of sub storms must be much larger than at Earth. The correspondence between the duration of tail field enhancements and the characteristic time for the Dungey cycle, which describes plasma circulation through Mercury's magnetosphere. suggests that such circulation determines substorm timescale. A key aspect of tail unloading during terrestrial substorms is the acceleration of energetic charged particles, but no acceleration signatures were seen during the MESSENGER flyby.

Slavin, James A.; Anderson, Brian J.; Baker, Daniel N.; Benna, Mehdi; Boardsen, Scott A.; Gloeckler, George; Gold, Robert E.; Ho, George C.; Korth, Haje; Krimigis, Stamatios M.; McNutt, Ralph L., Jr.; Nittler, Larry R.; Raines, Jim M.; Sarantos, Menelaos; Schriver, David; Solomon, Sean C.; Starr, Richard D.; Travnicek, Pavel M.; Zurbuchen, Thomas H.

2010-01-01

347

Engineering assessment of inactive uranium mill tailings, Green River Site, Green River, Utah  

SciTech Connect

Ford, Bacon and Davis Utah Inc. has reevaluated the Green River site in order to revise the December 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Green River, Utah. This evaluation 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 remedial actions. 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.

none,

1981-08-01

348

Calculation of the number of cancer deaths prevented by the Uranium Mill Tailings Remedial Action Project  

SciTech Connect

The Uranium Mill Tailings Remedial Action Project has completed remedial action at 22 uranium mill tailings sites and about 5,000 properties (vicinity properties) where tailings were used in construction, at a total cost of $1.45 billion. This paper uses existing data from Environmental Impact Statements and Environmental Assessments, and vicinity property calculations, to determine the total number of cancer deaths averted by the Uranium Mill Tailings Remedial Action Project. The cost-effectiveness of remediating each site, the vicinity properties, and the entire project is calculated. The cost per cancer death averted was four orders of magnitude higher at the least cost-effective site than at the most cost-effective site.

Miller, M.L.; Pomatto, C.B. (Roy F. Weston, Inc., Albuquerque, NM (United States)); Cornish, R.E. (Dept. of Energy, Albuquerque, NM (United States). Albuquerque Operations Office)

1999-05-01

349

Calculation of the number of cancer deaths prevented by the Uranium Mill Tailings Remedial Action Project.  

PubMed

The Uranium Mill Tailings Remedial Action Project has completed remedial action at 22 uranium mill tailings sites and about 5,000 properties ("vicinity properties") where tailings were used in construction, at a total cost of $1.45 billion. This paper uses existing data from Environmental Impact Statements and Environmental Assessments, and vicinity property calculations, to determine the total number of cancer deaths averted by the Uranium Mill Tailings Remedial Action Project. The cost-effectiveness of remediating each site, the vicinity properties, and the entire project is calculated. The cost per cancer death averted was four orders of magnitude higher at the least cost-effective site than at the most cost-effective site. PMID:10201569

Miller, M L; Cornish, R E; Pomatto, C B

1999-05-01

350

Detection and tracking of low contrast human sperm tail  

Microsoft Academic Search

Tracking sperm tail movement provides important information for clinical sperm research. It is also a crucial step for sperm immobilization in Intracytoplasmic Sperm Injection (ICSI). However, the low visibility of the sperm tail under optical microscopy, coupled with the sperm fast motility, render sperm tail identification and tracking challenging tasks to execute. This paper presents two approaches for sperm tail

Clement Leung; Zhe Lu; Navid Esfandiari; Robert F. Casper; Yu Sun

2010-01-01

351

A safety assessment of the new Xiangyun phosphogypsum tailings pond  

Microsoft Academic Search

Phosphogypsum tailings are piled up to form a phosphogypsum tailings pond. In the design and operation stages of a tailings project, the stability of the tailings pond, the control capacity for flood, and the reliability of the drainage and safety monitoring facilities should be fully evaluated. Key contents of the safety assessment are analyzed in view of the new Xiangyun

T. Wang; Y. Zhou; Q. Lv; Yuanle Zhu; C. Jiang

2011-01-01

352

Selenium promotes adipogenic determination and differentiation of chicken embryonic fibroblasts with regulation of genes involved in fatty acid uptake, triacylglycerol synthesis and lipolysis.  

PubMed

Selenium (Se) has been utilized in the differentiation of primary pig and rat preadipocytes, indicating that it may have proadipogenic potential; however, some studies have also demonstrated that Se has antiadipogenic activity. In this study, chicken embryonic fibroblasts (CEFs) were used to investigate the role of Se in adipogenesis in vitro and in ovo. Se supplementation increased lipid droplet accumulation and inhibited proliferation of cultured CEFs isolated from 6-day-old embryos dose-dependently. This suggests that Se may play a role in cell cycle inhibition, thereby promoting the differentiation of fibroblasts to adipocytes. Se did not stimulate adipogenic differentiation of CEFs isolated from 9- to 12-day-old embryos, implying a permissive stage of adipogenic determination by Se at earlier embryonic ages. Microarray analysis comparing control and Se treatments on CEFs from 6-day-old embryos and confirmatory analysis by quantitative real-time polymerase chain reaction revealed that genes involved in adipocyte determination and differentiation, fatty acid uptake and triacylglycerol synthesis were up-regulated. In addition, up-regulation of an anti-lipolytic G0/G1 switch gene 2 and down-regulation of a prolipolytic monoglyceride lipase may lead to inhibition of lipolysis by Se. Both osteogenic and myogenic genes were down-regulated, and several genes related to oxidative stress response during adipogenesis were up-regulated. In ovo injection of Se at embryonic day 8 increased adipose tissue mass by 30% and caused adipocyte hypertrophy in 17-day-old chicken embryos, further supporting the proadipogenic role of Se during the embryonic development of chickens. These results suggest that Se plays a significant role in several mechanisms related to adipogenesis. PMID:24838110

Hassan, Aishlin; Ahn, Jinsoo; Suh, Yeunsu; Choi, Young Min; Chen, Paula; Lee, Kichoon

2014-08-01

353

High-Efficiency Thermal Asymmetric Interlaced PCR (hiTAIL-PCR) for Determination of a Highly Degenerated Prophage WO Genome in a Wolbachia Strain Infecting a Fig Wasp Species  

PubMed Central

Temperate bacteriophage WO is a model system for studying tripartite interactions among viruses, bacteria, and eukaryotes, especially investigations of the genomic stability of obligate intracellular bacteria. Few WO genomes exist because of the difficulty in isolating viral DNA from eukaryotic hosts, and most reports are by-products of Wolbachia sequencing. Only one partial genome of a WO phage has been determined directly from isolated particles. We determine the complete genome sequence of prophage WO (WOSol) in Wolbachia strain wSol, which infects the fig wasp Ceratosolen solmsi (Hymenoptera: Chalcidoidea), by high-efficiency thermal asymmetric interlaced PCR. The genome of WOSol is highly degenerated and disrupted by a large region (14,267 bp) from Wolbachia. Consistent with previous molecular studies of multiple WO genomes, the genome of WOSol appears to have evolved by single nucleotide mutations and recombinations.

Wang, Guan-Hong; Xiong, Tuan-Lin; Li, Zi; Murphy, Robert W.

2013-01-01

354

Molecularly imprinted electrochemical biosensor based on Fe@Au nanoparticles involved in 2-aminoethanethiol functionalized multi-walled carbon nanotubes for sensitive determination of cefexime in human plasma.  

PubMed

The molecular imprinting technique depends on the molecular recognition. It is a polymerization method around the target molecule. Hence, this technique creates specific cavities in the cross-linked polymeric matrices. In present study, a sensitive imprinted electrochemical biosensor based on Fe@Au nanoparticles (Fe@AuNPs) involved in 2-aminoethanethiol (2-AET) functionalized multi-walled carbon nanotubes (f-MWCNs) modified glassy carbon (GC) electrode was developed for determination of cefexime (CEF). The results of X-ray photoelectron spectroscopy (XPS) and reflection-absorption infrared spectroscopy (RAIRS) confirmed the formation of the developed surfaces. CEF imprinted film was constructed by cyclic voltammetry (CV) for 9 cycles in the presence of 80 mM pyrrole in phosphate buffer solution (pH 6.0) containing 20mM CEF. The developed electrochemical biosensor was validated according to the International Conference on Harmonisation (ICH) guideline and found to be linear, sensitive, selective, precise and accurate. The linearity range and the detection limit were obtained as 1.0 × 10(-10)-1.0 × 10(-8)M and 2.2 × 10(-11)M, respectively. The developed CEF imprinted sensor was successfully applied to real samples such as human plasma. In addition, the stability and reproducibility of the prepared molecular imprinted electrode were investigated. The excellent long-term stability and reproducibility of the prepared CEF imprinted electrodes make them attractive in electrochemical sensors. PMID:24832202

Yola, Mehmet Lütfi; Eren, Tanju; Atar, Necip

2014-10-15

355

Simultaneous high-performance liquid chromatographic determination of catecholamine-related compounds by post-column derivatization involving coulometric oxidation followed by fluorescence reaction.  

PubMed

A highly selective and sensitive high-performance liquid chromatographic method for the determination of catecholamines (norepinephrine, epinephrine and dopamine) and related compounds (L-DOPA, normetanephrine, metanephrine, 3-methoxytyramine, 3,4-dihydroxymandelic acid, 3,4-dihydroxyphenylacetic acid, homovanillic acid, vanillylmandelic acid, 3,4-dihydroxyphenylethylene glycol, 4-hydroxy-3-methoxyphenylethylene glycol and 4-hydroxy-3-methoxyphenylethanol) with a post-column technique involving coulometric oxidation followed by fluorescence derivatization is described. These compounds, 3,4-dihydroxybenzylamine and ferulic acid are separated within 35 min by ion-pair reversed-phase chromatography using acidic buffers (pH 3.1) with methanol-acetonitrile (3:2, v/v) gradient elution, and then oxidized by a commercial coulometric detector to the corresponding o-quinones, which are converted into fluorescent derivatives by reaction with 1,2-diphenylethylenediamine. The detection limits (signal-to-noise ratio = 3) on-column are 1.5-4 pmol for the two mandelic acids, 600 fmol for L-DOPA and 20-70 fmol for the others. PMID:2753936

Nohta, H; Yamaguchi, E; Ohkura, Y; Watanabe, H

1989-04-21

356

Histochemical, Biochemical and Cell Biological aspects of tail regeneration in lizard, an amniote model for studies on tissue regeneration.  

PubMed

The present review summarizes biochemical, histochemical and immunocytochemical aspects of the process of tissue regeneration in lizards, non-mammalian amniotes with high regenerative power. The amputated tail initially mobilizes the glycogen and lipid reserves during wound healing. In the following stage of formation of the regenerative blastema tissue remodeling produces a typical embryonic tissue, initially increasing the amount of water and glycosaminoglycans such as jaluronate, which are later replaced by sulfated glycosaminoglycans and collagen during tail elongation. In blastematic and early differentiating stages the initial anaerobic metabolism utilizes glycolysis and hexose monophosphate pathways to sustain high RNA production and lipid catabolism for energy production. This stage, after formation of blood vessels, is replaced by the energy-efficient aerobic metabolism based on the Krebs' cycle that is needed for the differentiation and growth of the new tissues of the regenerating tail. Specific proteins of the cytoskeleton, extracellular matrix, cell junctions, transcriptional and growth factors are actively produced in the embryonic environment of early stages of regeneration and allow for cell movement, signaling and differentiation. During wound healing, the production of anti-microbial peptides in granulocytes is likely involved in limiting inflammation and stimulates tissue regeneration in the tail while the lasting inflammatory reaction of the limb and spinal cord limits their potential of regeneration. Activated hemopoiesis, circulating blood, endocrine glands, liver, kidney and spleen supply the regenerating tissues with metabolites and hormones but also with phagocytes and immuno-competent cells that can inhibit tissue regeneration after repetitive amputations that elicit chronic inflammation. The latter aspect shows how successful tissue regeneration in an amniote can be turned into scarring by the alteration of the initial microenvironment and inflammatory course, an inspiring model for understanding failure of tissue regeneration in higher vertebrates and humans. The participation of 5-Bromo-deoxyuridine (5BrdU) long retention cells, indicated as putative stem cells, for the following regeneration is analyzed and it shows that different tissue sites of the original tail contain putative stem cells that are likely activated from the wounding signal. In particular, the permanence of stem cells in the central canal of the spinal cord can explain the limited but important neurogenesis present in the caudal but also in the lumbar-thoracic spinal cord. In the latter, the limited number of glial and neurons regenerated is however sufficient to recover some limited hind limb movement after injury or spinal transection. Finally, the presence of stem cells in the spinal cord, in the regenerative blastema and skin allow to use these organs as a source of cells for studies on gene activation during cell differentiation in the new spinal cord, tail and in the epidermis. The above information form the basic knowledge for the future molecular studies on the specific gene activation capable to determine tail regeneration in lizards, and more in general genes involved in the reactivation of regeneration process in amniotes and humans. PMID:24387878

Alibardi, Lorenzo

2014-01-01

357

Tail current surge: New insights from a global MHD simulation and comparison with satellite observations  

NASA Astrophysics Data System (ADS)

The present study examines the tailward propagation of substorm-associated variations of the tail current intensity. In the substorm event of 24 November 1996, the Interball and IMP 8 satellites were located in the midnight sector at X = -26 and -36 RE, respectively, and observed an increase and a decrease of the lobe magnetic field strength corresponding to the storage and release of the lobe magnetic energy. Both spacecraft observed BZ to decrease initially and then increase in the course of the decrease in ?BX?, a feature that was reported previously as a manifestation of the tailward expansion of the current disruption region. The delay of the signatures between the two satellites confirms that the associated current system moved tailward. Motivated by this fortuitous coordination of the satellite observation, the present study revisits a global MHD simulation previously conducted specifically for this substorm event [, 2001]. The most noticeable feature of the modeled tail dynamics is the repeated occurrence of tail current surges, that is, temporal intensifications of the tail current that propagate tailward. The first tail current surge is accompanied by the stretching of the tail magnetic field, which starts in the inner magnetosphere and extends tailward. The associated tailward flow redistributes the plasma pressure in such a way that the tail current is reduced in its intensity in the near-Earth region, while the pressure gradient increases at the propagation front, which intensifies the local current. The last major tail current surge is caused by the near-Earth reconnection. Inside a plasmoid, the pressure gradient current is intensified on the tailward side of the O-line, and it propagates tailward as the plasmoid grows and is released. For each tail current surge, irrespective of its cause, the intensification of the tail current is followed by the reduction, and its tailward propagation creates the aforementioned phase relationship between BX and BZ. It is probably difficult to determine based on lobe magnetic field observations whether it is caused by the tail stretching or a neutral line motion. The present study not only sheds new light about tail substorm dynamics but also provides a good exercise for evaluating the potential of the modeling effort for substorm study in general.

Ohtani, Shin-Ichi; Raeder, Joachim

2004-01-01

358

Hydrology and geochemistry of the uranium mill tailings pile at Riverton, Wyoming. Part II. History matching. [Mathematical simulation of the observed fluid potentials within the tailings, and the observed distribution of various chemical species within and around the mill tailings  

SciTech Connect

In Part I of this series of two reports the observed fluid potential and geochemical characteristics in and around the inactive uranium mill tailings pile at Riverton, Wyoming were presented. The prupose of the present work is to attempt to simulate field observations using mathematical models. The results of the studies have not only helped identify the physicochemical mechanisms govering contaminant migration around the inactive mill tailings pile in Riverton, but also have indicated the feasibility of quantifying these mechanisms with the help of newly developed mathematical models. Much work needs to be done to validate and benchmark these models. The history-matching effort on hand involves the mathematical simulation of the observed fluid potentials within the tailings, and the observed distribution of various chemical species within and around the inactive uranium mill tailings. The simulation problem involves consideration of transient fluid flow and transient, reactive chemical transport in a variably saturated ground water system with time-dependent boundary conditions. 15 refs., 30 figs., 3 tabs.

Narasimhan, T.N.; White, A.F.; Tokunaga, T.

1985-02-01

359

Degrons at the C terminus of the pathogenic but not the nonpathogenic hantavirus G1 tail direct proteasomal degradation.  

PubMed

Pathogenic hantaviruses cause two human diseases: hantavirus pulmonary syndrome (HPS) and hemorrhagic fever with renal syndrome (HFRS). The hantavirus G1 protein contains a long, 142-amino-acid cytoplasmic tail, which in NY-1 virus (NY-1V) is ubiquitinated and proteasomally degraded (E. Geimonen, I. Fernandez, I. N. Gavrilovskaya, and E. R. Mackow, J. Virol. 77: 10760-10768, 2003). Here we report that the G1 cytoplasmic tails of pathogenic Andes (HPS) and Hantaan (HFRS) viruses are also degraded by the proteasome and that, in contrast, the G1 tail of nonpathogenic Prospect Hill virus (PHV) is stable and not proteasomally degraded. We determined that the signals which direct NY-1V G1 tail degradation are present in a hydrophobic region within the C-terminal 30 residues of the protein. In contrast to that of PHV, the NY-1V hydrophobic domain directs the proteasomal degradation of green fluorescent protein and constitutes an autonomous degradation signal, or "degron," within the NY-1V G1 tail. Replacing 4 noncontiguous residues of the NY-1V G1 tail with residues present in the stable PHV G1 tail resulted in a NY-1V G1 tail that was not degraded by the proteasome. In contrast, changing a different but overlapping set of 4 PHV residues to corresponding NY-1V residues directed proteasomal degradation of the PHV G1 tail. The G1 tails of pathogenic, but not nonpathogenic, hantaviruses contain intervening hydrophilic residues within the C-terminal hydrophobic domain, and amino acid substitutions that alter the stability or degradation of NY-1V or PHV G1 tails result from removing or adding intervening hydrophilic residues. Our results identify residues that selectively direct the proteasomal degradation of pathogenic hantavirus G1 tails. Although a role for the proteasomal degradation of the G1 tail in HPS or HFRS is unclear, these findings link G1 tail degradation to viral pathogenesis and suggest that degrons within hantavirus G1 tails are potential virulence determinants. PMID:17267477

Sen, Nandini; Sen, Adrish; Mackow, Erich R

2007-04-01

360

Plasma entry into the distant tail lobes - ISEE-3  

NASA Technical Reports Server (NTRS)

ISEE-3 measurements indicate that a broad mantle-like boundary layer plasma often exists within the distant geomagnetic tail lobes at all latitudes, directly adjacent to the tail magnetopause. The presence of this boundary layer at large tail distances indicates that plasma from the magnetosheath often crosses the magnetopause locally along much of the length of the tail, and is evidence that the tail is 'open'.

Gosling, J. T.; Baker, D. N.; Bame, S. J.; Hones, E. W., Jr.; Mccomas, D. J.; Zwickl, R. D.; Slavin, J. A.; Smith, E. J.; Tsurutani, B. T.

1984-01-01

361

Mass number and prompt neutron emission of individual fission fragments as functions of nuclear charge, both involving parameters determinable from radiochemical data  

NASA Astrophysics Data System (ADS)

We lack an equation relating fission fragment mass before prompt neutron emission to the mass of the resulting fission product. It is shown that by using conveniently defined auxiliary functions and partly neglecting fine structure effects, expressions may be derived for mass number, charge density, and prompt neutron yields of individual fission fragments. All expressions involve parameters which can be evaluated from radiochemical fission product yield data, without recourse to any physical measurement whatsoever. The expressions for neutron yields from individual fragments reproduce the well-known saw-tooth curve. The fragment mass number as a function of charge is composed of two parallel straight lines with a simple discontinuity at symmetric charge division. Similarly, the fragment charge density versus charge has two branches extending in the heavy and light fragment regions, respectively. The corresponding relationship is a homographic function of charge, and is discontinuous at symmetric charge division, where Dirichlet's theorem applies. In the fission of 238U, the two branches come closer together at symmetric charge division as excitation energy of the fissioning nucleus increases. The expressions mentioned above have been applied to nine different low excitation energy (<=14 MeV) fission processes for which selected recommended data are available. Comparison is made with published data wherever available; in general, good agreement is observed. The expression predicted by the liquid drop model for mass asymmetry of fission is shown to be identically valid for charge and neutron asymmetry also. Two new identities are also reported. In addition, two quantities are defined, namely, the inverse charge density with respect to nucleons and that with respect to neutrons. It is shown that the arithmetic mean of either of these quantities for the average light and heavy fragments equals the corresponding quantity for the fissioning nucleus, and that this equality holds true with notable accuracy in all low-energy fission processes considered. NUCLEAR REACTIONS, FISSION 232Th, 233U, 235U, 238U, 239Pu, 252Cf. Expressions for fragment mass, charge density, and neutron yields versus charge involving parameters determinable from radiochemical yields.

Talât-Erben, M.; Tokay, R. K.

1981-09-01

362

Acid rock drainage and metal leaching from mine waste material (tailings) of a Pb-Zn-Ag skarn deposit: environmental assessment through static and kinetic laboratory tests  

Microsoft Academic Search

In this work, the processes and products involved in the generation of acid rock drainage - metal leaching (ARD-ML) from mine waste material (tailings) derived from the exploitation of an ore type Pb- Zn-Ag skarn were characterized. Laboratory tests (static and kinetic) of historic and recent tailings were conducted along with the mineralogical characterization of solids, and chemical analyses of

Blanca Adriana Méndez-Ortiz; Alejandro Carrillo-Chávez; Marcos Gustavo Monroy-Fernández

2007-01-01

363

Transonic Base and Boat-Tail Pressure Drag of Cylindrical Bodies with Conical Boat-Tails.  

National Technical Information Service (NTIS)

This Item provides a means of estimating the base and boat-tail pressure-drag coefficients of cylindrical bodies with conical boat-tailing for the Mach number range 0.9 less than or equal to 1.3. The method is purely empirical and is based on one develope...

1978-01-01

364

Growth performance and carcass quality of fattening lambs from fat-tailed and tailed sheep breeds  

Microsoft Academic Search

The growth performance and carcass traits of two fat-tailed breeds (Chaal and Zandi) and their crosses with rams of a tailed breed (Zel) were compared. After weaning, the growth and feed consumption of male and female lambs fattened for 114 days were recorded. A total of 45 male and female lambs were slaughtered and the left side of the carcasses

N. E. J. Kashan; G. H. Manafi Azar; A. Afzalzadeh; A. Salehi

2005-01-01

365

Grouting of uranium mill tailings piles  

SciTech Connect

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/sup -3/ cm/s to values approaching 10/sup -7/ cm/s using silicate grouts and to 10/sup -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.

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

1984-03-01

366

THE DUST TAIL OF ASTEROID (3200) PHAETHON  

SciTech Connect

We report the discovery of a comet-like tail on asteroid (3200) Phaethon when imaged at optical wavelengths near perihelion. In both 2009 and 2012, the tail appears {approx}>350'' (2.5 Multiplication-Sign 10{sup 8} m) in length and extends approximately in the projected anti-solar direction. We interpret the tail as being caused by dust particles accelerated by solar radiation pressure. The sudden appearance and the morphology of the tail indicate that the dust particles are small, with an effective radius {approx}1 {mu}m and a combined mass {approx}3 Multiplication-Sign 10{sup 5} kg. These particles are likely products of thermal fracture and/or desiccation cracking under the very high surface temperatures ({approx}1000 K) experienced by Phaethon at perihelion. The existence of the tail confirms earlier inferences about activity in this body based on the detection of anomalous brightening. Phaethon, the presumed source of the Geminid meteoroids, is still active.

Jewitt, David; Li Jing [Department of Earth and Space Sciences, University of California at Los Angeles, 595 Charles Young Drive East, Los Angeles, CA 90095-1567 (United States); Agarwal, Jessica, E-mail: jewitt@ucla.edu [Max Planck Institute for Solar System Research, Max-Planck-Str. 2, D-37191 Katlenburg-Lindau (Germany)

2013-07-10

367

Tail vaccination in cats: a pilot study.  

PubMed

Feline injection site sarcomas affect 1-10 cats per every 10,000 vaccinated and are associated with high mortality. Radical resection may be curative, but is often associated with prolonged recovery, disfigurement and loss of function when tumors occur at currently recommended injection sites. The objective of this study was to assess alternatives to currently recommended vaccination sites in terms of preference by oncology practitioners, ease of injection and serological responses. Surgical, radiation and medical oncology practitioners were surveyed regarding their preference for vaccination sites based on the ease of tumor resection. A six-point Likert scale was used to measure each cat's behavioral reaction to vaccination when injected subcutaneously in the distal hind limb or the distal tail. Serum collected before and 1-2 months after vaccination was tested for antibody titers against feline panleukopenia virus (FPV) and rabies virus (RV). The preferred sites for vaccination by 94 oncology practitioners were below the stifle (41%) and the tail (30%). There were no significant differences in the cats' behavioral reaction to vaccination below the stifle (n = 31) and in the distal tail (n = 29). Of the cats seronegative for FPV at the time of vaccination, 100% developed protective antibody titers (?40) against FPV 1-2 months following vaccination. For cats seronegative for RV, all but one cat (tail vaccine) developed acceptable antibody titers (?0.5 IU/ml) against RV. Tail vaccination was well tolerated and elicited similar serological responses to vaccination in the distal limbs. PMID:24108201

Hendricks, Cleon G; Levy, Julie K; Tucker, Sylvia J; Olmstead, Shaye M; Crawford, P Cynda; Dubovi, Edward J; Hanlon, Cathleen A

2014-04-01

368

Cargo binding and regulatory sites in the tail of fungal conventional kinesin  

Microsoft Academic Search

Here, using a quantitative in vivo assay, we map three regions in the carboxy terminus of conventional kinesin that are involved in cargo association, folding and regulation, respectively. Using C-terminal and internal deletions, point mutations, localization studies, and an engineered ‘minimal’ kinesin, we identify five heptads of a coiled-coil domain in the kinesin tail that are necessary and sufficient for

Stephan Seiler; Jochen Kirchner; Christian Horn; Athina Kallipolitou; Günther Woehlke; Manfred Schliwa

2000-01-01

369

Effects of White-Tailed Deer on Populations of an Understory Forb in Fragmented Deciduous Forests  

Microsoft Academic Search

The effects of grazing by white-tailed deer ( Odocoileus virginianus ) on populations of Trillium spp. were examined in remnant, old-growth patches of the highly fragmented Big Woods forest ecosystem in south- eastern Minnesota. We conducted three separate studies involving an exclosure experiment, transplant exper- iments, and comparisons of Trillium populations among study sites. The highest grazing intensity was ob-

David J. Augustine; Lee E. Frelich

1998-01-01

370

Long-term contaminant migration and impacts from uranium mill tailings  

Microsoft Academic Search

As part of the BIOMOVS II study, a Working Group was established with the primary aim of comparing computer models used to assess the long-term impacts of contaminants released from uranium mill tailings piles, involving multiple pathways, multiple contaminants and multiple environmental receptors. The application of models to two scenarios (V1 and V2) allowed participants to gain an improved understanding

H. Camus; R. Little; D. Acton; A. Agüero; D. Chambers; L. Chamney; J. L. Daroussin; J. Droppo; C. Ferry; E. Gnanapragasam; C. Hallam; J. Horyna; D. Lush; D. Stammose; T. Takahashi; L. Toro; C. Yu

1998-01-01

371

Identification of chromosomal locations associated with tail biting and being a victim of tail-biting behaviour in the domestic pig (Sus scrofa domesticus).  

PubMed

The objective of this study was to identify loci associated with tail biting or being a victim of tail biting in Norwegian crossbred pigs using a genome-wide association study with PLINK case-control analysis. DNA was extracted from hair or blood samples collected from 98 trios of crossbred pigs located across Norway. Each trio came from the same pen and consisted of one pig observed to initiate tail biting, one pig which was the victim of tail biting and a control pig which was not involved in either behaviour. DNA was genotyped using the Illumina PorcineSNP60 BeadChip whole-genome single-nucleotide polymorphism (SNP) assay. After quality assurance filtering, 53,952 SNPs remained comprising 74 animals (37 pairs) for the tail biter versus control comparison and 53,419 SNPs remained comprising 80 animals (40 pairs) for the victim of tail biting versus control comparison. An association with being a tail biter was observed on Sus scrofa chromosome 16 (SSC16; p = 1.6 × 10(-5)) and an unassigned chromosome (p = 3.9 × 10(-5)). An association with being the victim of tail biting was observed on Sus scrofa chromosomes 1 (SSC1; p = 4.7 × 10(-5)), 9 (SSC9; p = 3.9 × 10(-5)), 18 (SSC18; p = 7 × 10(-5) for 9,602,511 bp, p = 3.4 × 10(-5) for 9,653,881 bp and p = 5.3 × 10(-5) for 29,577,783 bp) and an unassigned chromosome (p = 6.1 × 10(-5)). An r(2) = 0.96 and a D' = 1 between the two SNPs at 9 Mb on SSC18 indicated extremely high linkage disequilibrium, suggesting that these two markers represent a single locus. These results provide evidence of a moderate genetic association between the propensity to participate in tail-biting behaviour and the likelihood of becoming a victim of this behaviour. PMID:22941514

Wilson, Kaitlin; Zanella, Ricardo; Ventura, Carlos; Johansen, Hanne Lind; Framstad, Tore; Janczak, Andrew; Zanella, Adroaldo J; Neibergs, Holly Louise

2012-11-01

372

Evolution to Pathogenicity of the Parvovirus Minute Virus of Mice in Immunodeficient Mice Involves Genetic Heterogeneity at the Capsid Domain That Determines Tropism?  

PubMed Central

Very little is known about the role that evolutionary dynamics plays in diseases caused by mammalian DNA viruses. To address this issue in a natural host model, we compared the pathogenesis and genetics of the attenuated fibrotropic and the virulent lymphohematotropic strains of the parvovirus minute virus of mice (MVM), and of two invasive fibrotropic MVM (MVMp) variants carrying the I362S or K368R change in the VP2 major capsid protein, in the infection of severe combined immunodeficient (SCID) mice. By 14 to 18 weeks after oronasal inoculation, the I362S and K368R viruses caused lethal leukopenia characterized by tissue damage and inclusion bodies in hemopoietic organs, a pattern of disease found by 7 weeks postinfection with the lymphohematotropic MVM (MVMi) strain. The MVMp populations emerging in leukopenic mice showed consensus sequence changes in the MVMi genotype at residues G321E and A551V of VP2 in the I362S virus infections or A551V and V575A changes in the K368R virus infections, as well as a high level of genetic heterogeneity within a capsid domain at the twofold depression where these residues lay. Amino acids forming this capsid domain are important MVM tropism determinants, as exemplified by the switch in MVMi host range toward mouse fibroblasts conferred by coordinated changes of some of these residues and by the essential character of glutamate at residue 321 for maintaining MVMi tropism toward primary hemopoietic precursors. The few viruses within the spectrum of mutants from mice that maintained the respective parental 321G and 575V residues were infectious in a plaque assay, whereas the viruses with the main consensus sequences exhibited low levels of fitness in culture. Consistent with this finding, a recombinant MVMp virus carrying the consensus sequence mutations arising in the K368R virus background in mice failed to initiate infection in cell lines of different tissue origins, even though it caused rapid-course lethal leukopenia in SCID mice. The parental consensus genotype prevailed during leukopenia development, but plaque-forming viruses with the reversion of the 575A residue to valine emerged in affected organs. The disease caused by the DNA virus in mice, therefore, involves the generation of heterogeneous viral populations that may cooperatively interact for the hemopoietic syndrome. The evolutionary changes delineate a sector of the surface of the capsid that determines tropism and that surrounds the sialic acid receptor binding domain.

Lopez-Bueno, Alberto; Segovia, Jose C.; Bueren, Juan A.; O'Sullivan, M. Gerard; Wang, Feng; Tattersall, Peter; Almendral, Jose M.

2008-01-01

373

RNA binding mediates the local cooperativity between the beta-sheet and the C-terminal tail of the human U1A RBD1 protein.  

PubMed

Pairwise coupling theory is applied here to determine the energetic interactions between two elements of the N-terminal RNA binding domain (RBD) of the human U1A protein. The novel application of the theory to this system incorporates both measurements of protein stability and RNA binding to define thermodynamic cycles. In this first example of the application, two regions of the protein are selected for study: tyrosine 13, one of the conserved aromatic residues on the surface of the beta-sheet, and the C-terminal tail of the RBD. The six initial pairwise coupling free energies derived from this system describe the communication between these positions, both in the free and RNA-bound states of the protein. The results show that in the absence of RNA, these two elements of the protein act independently. However, when RNA is bound, there is indirect coupling between Tyr13 and the tail, mediated through the RNA. Subsequent thermodynamic cycles involving additional perturbations to the C-terminal tail further define the communication between the C terminus and the beta-sheet. This work demonstrates the general applicability of the pairwise coupling theory to protein:nucleic acid interactions, and illustrates the necessity of such analyses to describe the network of energetic interactions that comprise RNA recognition by this RBD. PMID:9466924

Kranz, J K; Hall, K B

1998-01-23

374

Effect of tail size reductions on longitudinal aerodynamic characteristics of a three surface F-15 model with nonaxisymmetric nozzles  

NASA Technical Reports Server (NTRS)

An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine the effects of horizontal and vertical tail size reductions on the longitudinal aerodynamic characteristics of a modified F-15 model with canards and 2-D convergent-divergent nozzles. Quantifying the drag decrease at low angles of attack produced by tail size reductions was the primary focus. The model was tested at Mach numbers of 0.40, 0.90, and 1.20 over an angle of attack of -2 degree to 10 degree. The nozzle exhaust flow was simulated using high pressure air at nozzle pressure ratios varying from 1.0 (jet off) to 7.5. Data were obtained on the baseline configuration with and without tails as well as with reduced horizontal and/or vertical tail sizes that were 75, 50, and 25 percent of the baseline tail areas.

Frassinelli, Mark C.; Carson, George T., Jr.

1990-01-01

375

The use of one- versus two-tailed tests to evaluate prevention programs.  

PubMed

Investigators have used both one- and two-tailed tests to determine the significance of findings yielded by program evaluations. While the literature that addresses the appropriate use of each type of significance test should be used is historically inconsistent, almost all authorities now agree that one-tailed tests are rarely (if ever) appropriate. A review of 85 published evaluations of school-based drug prevention curricula specified on the National Registry of Effective Programs and Practices revealed that 20% employed one-tailed tests and, within this subgroup, an additional 4% also employed two-tailed tests. The majority of publications either did not specify the type of statistical test employed or used some other criterion such as effect sizes or confidence intervals. Evaluators reported that they used one-tailed tests either because they stipulated the direction of expected findings in advance, or because prior evaluations of similar programs had yielded no negative results. The authors conclude that one-tailed tests should never be used because they introduce greater potential for Type I errors and create an uneven playing field when outcomes are compared across programs. The authors also conclude that the traditional threshold of significance that places ? at .05 is arbitrary and obsolete, and that evaluators should consistently report the exact p values they find. PMID:21138911

Ringwalt, Chris; Paschall, M J; Gorman, Dennis; Derzon, James; Kinlaw, Alan

2011-06-01

376

Gecko CD59 Is Implicated in Proximodistal Identity during Tail Regeneration  

PubMed Central

Several adult reptiles, such as Gekko japonicus, have the ability to precisely re-create a missing tail after amputation. To ascertain the associated acquisition of positional information from blastemal cells and the underlying molecular mechanism of tail regeneration, a candidate molecule CD59 was isolated from gecko. CD59 transcripts displayed a graded expression in the adult gecko spinal cord with the highest level in the anterior segment, with a stable expression along the normal tail. After tail amputation, CD59 transcripts in the spinal cord proximal to the injury sites increased markedly at 1 day and 2 weeks; whereas in the regenerating blastema, strong CD59 positive signals were detected in the blastemal cells anterior to the blastema, with a gradual decrease along the proximodistal (PD) axis. When treated with RA following amputation, CD59 transcripts in the blastema were up-regulated. PD confrontation assays revealed that the proximal blastema engulfed the distal one after in vitro culture, and rabbit-anti human CD59 antibody was able to block this PD engulfment. Overexpression of the CD59 during tail regeneration causes distal blastemal cells to translocate to a more proximal location. Our results suggest that position identity is not restricted to amphibian limb regeneration, but has already been established in tail blastema of reptiles. The CD59, a cell surface molecule, acted as a determinant of proximal–distal cell identity.

Jiang, Shengjuan; Zhou, Weijuan; Liu, Yan; Wang, Yingjie; Gu, Qing; Gu, Yun; Dong, Yingying; Liu, Mei; Gu, Xingxing; Ding, Fei; Gu, Xiaosong

2011-01-01

377

Gecko CD59 is implicated in proximodistal identity during tail regeneration.  

PubMed

Several adult reptiles, such as Gekko japonicus, have the ability to precisely re-create a missing tail after amputation. To ascertain the associated acquisition of positional information from blastemal cells and the underlying molecular mechanism of tail regeneration, a candidate molecule CD59 was isolated from gecko. CD59 transcripts displayed a graded expression in the adult gecko spinal cord with the highest level in the anterior segment, with a stable expression along the normal tail. After tail amputation, CD59 transcripts in the spinal cord proximal to the injury sites increased markedly at 1 day and 2 weeks; whereas in the regenerating blastema, strong CD59 positive signals were detected in the blastemal cells anterior to the blastema, with a gradual decrease along the proximodistal (PD) axis. When treated with RA following amputation, CD59 transcripts in the blastema were up-regulated. PD confrontation assays revealed that the proximal blastema engulfed the distal one after in vitro culture, and rabbit-anti human CD59 antibody was able to block this PD engulfment. Overexpression of the CD59 during tail regeneration causes distal blastemal cells to translocate to a more proximal location. Our results suggest that position identity is not restricted to amphibian limb regeneration, but has already been established in tail blastema of reptiles. The CD59, a cell surface molecule, acted as a determinant of proximal-distal cell identity. PMID:21464923

Wang, Yongjun; Wang, Ruili; Jiang, Shengjuan; Zhou, Weijuan; Liu, Yan; Wang, Yingjie; Gu, Qing; Gu, Yun; Dong, Yingying; Liu, Mei; Gu, Xingxing; Ding, Fei; Gu, Xiaosong

2011-01-01

378

Research investigation of helicopter main rotor/tail rotor interaction noise  

NASA Technical Reports Server (NTRS)

Acoustic measurements were obtained in a Langley 14 x 22 foot Subsonic Wind Tunnel to study the aeroacoustic interaction of 1/5th scale main rotor, tail rotor, and fuselage models. An extensive aeroacoustic data base was acquired for main rotor, tail rotor, fuselage aerodynamic interaction for moderate forward speed flight conditions. The details of the rotor models, experimental design and procedure, aerodynamic and acoustic data acquisition and reduction are presented. The model was initially operated in trim for selected fuselage angle of attack, main rotor tip-path-plane angle, and main rotor thrust combinations. The effects of repositioning the tail rotor in the main rotor wake and the corresponding tail rotor countertorque requirements were determined. Each rotor was subsequently tested in isolation at the thrust and angle of attack combinations for trim. The acoustic data indicated that the noise was primarily dominated by the main rotor, especially for moderate speed main rotor blade-vortex interaction conditions. The tail rotor noise increased when the main rotor was removed indicating that tail rotor inflow was improved with the main rotor present.

Fitzgerald, J.; Kohlhepp, F.

1988-01-01

379

Spatial Characteristics of the Unsteady Differential Pressures on 16 percent F/A-18 Vertical Tails  

NASA Technical Reports Server (NTRS)

Buffeting is an aeroelastic phenomenon which plagues high performance aircraft at high angles of attack. For the F/A-18 at high angles of attack, vortices emanating from wing/fuselage leading edge extensions burst, immersing the vertical tails in their turbulent wake. The resulting buffeting of the vertical tails is a concern from fatigue and inspection points of view. Previous flight and wind-tunnel investigations to determine the buffet loads on the tail did not provide a complete description of the spatial characteristics of the unsteady differential pressures. Consequently, the unsteady differential pressures were considered to be fully correlated in the analyses of buffet and buffeting. The use of fully correlated pressures in estimating the generalized aerodynamic forces for the analysis of buffeting yielded responses that exceeded those measured in flight and in the wind tunnel. To learn more about the spatial characteristics of the unsteady differential pressures, an available 16%, sting-mounted, F-18 wind-tunnel model was modified and tested in the Transonic Dynamics Tunnel (TDT) at the NASA Langley Research Center as part of the ACROBAT (Actively Controlled Response Of Buffet-Affected Tails) program. Surface pressures were measured at high angles of attack on flexible and rigid tails. Cross-correlation and cross-spectral analyses of the pressure time histories indicate that the unsteady differential pressures are not fully correlated. In fact, the unsteady differential pressure resemble a wave that travels along the tail. At constant angle of attack, the pressure correlation varies with flight speed.

Moses, Robert W.; Ashley, Holt

1998-01-01

380

Investigation of the origin of the heliospheric suprathermal tail from analysis of particle and field data  

NASA Astrophysics Data System (ADS)

At energies exceeding that of the core particles of solar wind and pick-up ions, there exists a ubiquitous suprathermal (ST) tail that extends many orders of magnitude in energy. The form of this tail has been studied for some time, but its origin remains unclear. Theories abound for the acceleration mechanism, which generally fall into the two categories of generalized shock (Fermi-1) acceleration and stochastic/turbulent (Fermi-2) acceleration. We investigate the question of the origin of the ST tail by 1) analyzing available spacecraft particle and field data and 2) testing plausible theories against those data. Many small studies of the tail have been performed with some of these data; we address the origin of the ST tail by compiling a large amount of data. Drawing from a larger data pool, we can test the many theories that attempt to explain the tail's physical origin and determine which theory is the most likely to be correct with some statistical certainty.

Randol, B. M.

2012-12-01

381

Use of phosphate compounds to extract thorium-230 and radium-226 from uranium ore and tailings  

Microsoft Academic Search

Orthophosphate and condensed phosphates (pyrophosphate, tripolyphosphate and hexametaphosphate) were tested to determine whether they were capable of forming soluble complexes with thorium-230 and radium-226 in a sulfuric acid or neutral medium. The tests were carried out to determine whether these compounds would be useful for removing thorium and radium from solid uranium mill tailings prior to disposal. Results showed that

Hawley

1980-01-01

382

Design of tailing dam using red mud  

NASA Astrophysics Data System (ADS)

Red mud, waste industrial product from aluminum industries produced approximately 75 million tonnes every year with less than half of this is used. Storage of this unutilized red mud takes vast tracts of usable land and pollutes, land, air and water. Construction of high embankments, under passes, flyovers, tailing dams uses vast tract of natural resources (top soil) is also matter of concern as its takes thousands of years to form the natural soil. This paper discusses use of red mud for construction of tailing dam based on laboratory findings and finite element analysis. The geotechnical properties such as plasticity, compaction, permeability, shear strength characteristics and dispersion of red mud are presented. Stability and seepage analysis of tailing dams as per finite element analysis using the above geotechnical parameters is presented.

Rout, Subrat K.; Sahoo, Tapaswini; Das, Sarat K.

2013-06-01

383

A Study on Solidification of Abandoned Mine Tailings with Hydrated Lime  

NASA Astrophysics Data System (ADS)

Solidification is one of the stabilization processes for wastes and their components to reduce their toxicity and migration rates to surroundings. Hydrated limes were applied as cementing materials to solidify heavy metal contaminated tailings from the Geumjang mine and the solidified tailing specimens were tested for their appropriateness in accordance with the suggested test methods. In the preliminary tests for the solidified tailing specimens, all the specimens have higher uniaxial compressive strengths than 3.5kgf/cm2, the standard recommended for land reclamation solids by EPA(Environmental Protection Agency). Even in leaching tests for the solidified tailing specimens, concentrations of heavy metals such as As, Cd, Cu, Pb, and Zn were decreased significantly below the environmental warning standards in comparison with those of raw tailing samples. The optimum mixing ratio of tailings, hydrated lime, and water was determined through the preliminary tests. The solidified mixtures of mine tailings and hydrated lime through pozzolanic reaction were tested for their durability against repeated freezing and thawing processes. After repeated freezing and thawing, the uniaxial compressive strengths of all the solidified mixture specimens decreased in comparison with those before test but still higher than 3.5kgf/cm2, and concentrations of heavy metals such as As, Cd, Cu, Pb, and Zn were below the standards. Effluents in the repetitive artificial tests show pH's of 7.4 to 9.1 and concentrations of heavy metals such as As, Cd, Cu, Pb, and Zn of below 0.05ppm. Conclusively this study shows potential applicability of hydrated limes to in-situ stabilization of abandoned mine tailings.

Min, K.; Lee, H.

2008-12-01

384

Subsonic Aerodynamic Characteristics of an Airplane Configuration with a 63 deg Sweptback Wing and Twin-Boom Tails  

NASA Technical Reports Server (NTRS)

A wind-tunnel investigation has been conducted to determine the effects of an unconventional tail arrangement on the subsonic static longitudinal and lateral stability characteristics of a model having a 63 deg sweptback wing of aspect ratio 3.5 and a fuselage. Tail booms, extending rearward from approximately the midsemispan of each wing panel, supported independent tail assemblies well outboard of the usual position at the rear of the fuselage. The horizontal-tail surfaces had the leading edge swept back 45 deg and an aspect ratio of 2.4. The vertical tail surfaces were geometrically similar to one panel of the horizontal tail. For comparative purposes, the wing-body combination was also tested with conventional fuselage-mounted tail surfaces. The wind-tunnel tests were conducted at Mach numbers from 0.25 to 0.95 with a Reynolds number of 2,000,000, at a Mach number of 0.46 with a Reynolds number of 3,500,000, and at a Mach number of 0.20 with a Reynolds number of 7,000,000. The results of the investigation indicate that longitudinal stability existed to considerably higher lift coefficients for the outboard tail configuration than for the configuration with conventional tail. Wing fences were necessary with both configurations for the elimination of sudden changes in longitudinal stability at lift coefficients between 0.3 and 0.5. Sideslip angles up to 15 deg had only small effects upon the pitching-moment characteristics of the outboard tail configuration. There was an increase in the directional stability for the outboard tail configuration at the higher angles of attack as opposed to a decrease for the conventional tail configuration at most of the Mach numbers and Reynolds numbers of this investigation. The dihedral effect increased rapidly with increasing angle of attack for both the outboard and the conventional tail configurations but the increase was greater for the outboard tail configuration. The data indicate that the outboard tail is an effective roll control.

Savage, Howard F.; Edwards, George G.

1959-01-01

385

Breeding biology and nest-site selection of red-tailed hawks in an altered desert grassland  

USGS Publications Warehouse

Red-tailed Hawks (Buteo jamaicensis) have expanded their range as trees have invaded formerly-open grasslands. Desert grasslands of southern Arizona have been invaded by mesquite trees (Prosopis velutina) since Anglo-American settlement and now support a large population of Red-tailed Hawks. We studied a population of Red-tailed Hawks in an altered desert grassland in southern Arizona. Our objectives were to determine what environmental characteristics influence Red-tailed Hawk habitat selection in mesquite-invaded desert grasslands and to evaluate the habitat quality of these grasslands for Red-tailed Hawks based on nesting density, nest success, and productivity. Red-tailed Hawks had 86% (95% C.I. = 73-99) nest success and 1.82 young per breeding pair (95% C.I. = 1.41-2.23). Nesting density was 0.15 (95% CI = 0.08-0.21) breeding pairs/km2 and the mean nearest-neighbor distance was 1.95 km (95% C.I. = 1.74-2.16). Red-tailed Hawks selected nest-sites with taller nest-trees and greater tree height and cover than were available at random. Mesquite trees in desert grasslands provide abundant potential nesting structures for Red-tailed Hawks. ?? 2006 The Raptor Research Foundation, Inc.

Hobbs, R. J.; DeStefano, S.; Halvorson, W. L.

2006-01-01

386

Radial tail resolution in the SELEX RICH  

NASA Astrophysics Data System (ADS)

We use a seven million event data sample of 600 GeV/c single-track pion events, where the pion track is reconstructed upstream and downstream of the SELEX RICH. We build the RICH ring radius histogram distribution and count the tail events that fall outside 5?, giving a fraction of 4×10-5 events outside the Gaussian tails. This control of events establishes the ability of using the RICH as a velocity spectrometer for high-precision searches of the K+??+ ? ?¯ decay like it is planned in the CKM experiment.

Morelos, A.; Mata, J.; Cooper, P. S.; Engelfried, J.; Aguilera-Servin, J. L.

2005-11-01

387

Gaps and tails in graphene and graphane  

NASA Astrophysics Data System (ADS)

We study the density of states (DOS) in monolayer and bilayer graphene in the presence of a random potential that breaks sublattice symmetries. While a uniform symmetry-breaking potential (SBP) opens a uniform gap, a random SBP also creates tails in the DOS. The latter can close the gap again, preventing the system from becoming an insulator. However, for a sufficiently large gap the tails contain localized states with nonzero DOS. These localized states allow the system to conduct at nonzero temperature via variable-range hopping. This result is in agreement with recent experimental observations in graphane by Elias et al (2009 Science 323 610).

Dóra, B.; Ziegler, K.

2009-09-01

388

Radial tail resolution in the SELEX RICH  

SciTech Connect

The authors use a 7 Million event data sample of 600 GeV/c single track pion events, where the pion track is reconstructed upstream and downstream of the SELEX RICH. They build the RICH ring radius histogram distribution and count the tail events that fall outside 5{sigma}, giving a fraction of 4 x 10{sup -5} events outside the Gaussian tails. This control of events establishes the ability of using the RICH as velocity spectrometer for high precision searches of the K{sup +} {yields} {pi}{sup +} {nu}{bar {nu}} decay like it is planned in the CKM experiment.

Morelos, A.; Mata, J.; Cooper, P.S.; Engelfried, J.; Aguilera-Servin, J.L.; /San Luis Potosi U. /Fermilab

2005-01-01

389

Pioneer fauna of nepheline-containing tailings  

NASA Astrophysics Data System (ADS)

The zoological analysis of nepheline-containing sands deposited in tailings 10-40 years ago showed that the pioneer colonists of this technogenic substrate are collembolan and mites, whose proportions depend on the succession of the bacterial and fungal components of the microbiota. The pioneer groups of mesofauna on 10- to 30-year-old tailings include carnivorous herpetobiontic arthropods and phytophagous insects. An impoverished version of the fauna of northern-taiga podzols is developed in the sands rehabilitated more than 40 years ago.

Zenkova, I. V.; Kalmykova, V. V.; Liskovaya, A. A.

2009-08-01

390

Dynamics of Histone Tails within Chromatin  

NASA Astrophysics Data System (ADS)

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.

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

2012-02-01

391

Static strain and vibration characteristics of a metal semimonocoque helicopter tail cone of moderate size  

NASA Technical Reports Server (NTRS)

The results are presented of an analytic and experimental research program involving a Sikorsky S-55 helicopter tail cone directed ultimately to the improved structural analysis of airframe substructures typical of moderate sized helicopters of metal semimonocoque construction. Experimental static strain and dynamic shake-testing measurements are presented. Correlation studies of each of these tests with a PC-based finite element analysis (COSMOS/M) are described. The tests included static loadings at the end of the tail cone supported in the cantilever configuration as well as vibrational shake-testing in both the cantilever and free-free configurations.

Bielawa, Richard L.; Hefner, Rachel E.; Castagna, Andre

1991-01-01

392

PRION PROTEIN GENE HETEROGENEITY IN FREE-RANGING WHITE-TAILED DEER WITHIN THE CHRONIC WASTING DISEASE AFFECTED REGION OF WISCONSIN  

Microsoft Academic Search

Chronic wasting disease (CWD) was first identified in Wisconsin (USA) in white- tailed deer (Odocoileus virginianus) in February 2002. To determine if prion protein gene (Prnp) allelic variability was associated with CWD in white-tailed deer from Wisconsin, we sequenced Prnp from 26 CWD-positive and 100 CWD-negative deer. Sequence analysis of Prnp suggests that at least 86-96% of the white-tailed deer

Chad Johnson; Jody Johnson; Murray Clayton; Debbie McKenzie; Judd Aiken

393

TIDAL TAILS OF MINOR MERGERS: STAR FORMATION EFFICIENCY IN THE WESTERN TAIL OF NGC 2782  

SciTech Connect

While major mergers and their tidal debris are well studied, they are less common than minor mergers (mass ratios {approx}< 0.3). The peculiar spiral NGC 2782 is the result of a merger between two disk galaxies with a mass ratio of {approx}4: 1 occurring {approx}200 Myr ago. This merger produced a molecular and H I-rich, optically bright eastern tail and an H I-rich, optically faint western tail. Non-detection of CO in the western tail by Braine et al. suggested that star formation had not yet begun to occur in that tidal tail. However, deep H{alpha} narrowband images show evidence of recent star formation in the western tail. Across the entire western tail, we find the global star formation rate per unit area ({Sigma}{sub SFR}) to be several orders of magnitude less than expected from the total gas density. Together with extended FUV+NUV emission from Galaxy Evolution Explorer along the tail, this indicates a low global star formation efficiency in the tidal tail producing lower mass star clusters. The H II region that we observed has a local (few-kiloparsec scale) {Sigma}{sub SFR} from H{alpha} that is less than that expected from the total gas density, which is consistent with other observations of tidal debris. The star formation efficiency of this H II region inferred from the total gas density is low, but normal when inferred from the molecular gas density. These results suggest the presence of a very small, locally dense region in the western tail of NGC 2782 or of a low-metallicity and/or low-pressure star-forming region.

Knierman, Karen; Scowen, Paul; Jansen, Rolf A. [School of Earth and Space Exploration, Arizona State University, 550 East Tyler Mall, Room PSF-686 (P.O. Box 871404), Tempe, AZ 85287-1404 (United States); Knezek, Patricia M. [WIYN Consortium, Inc., 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Wehner, Elizabeth, E-mail: karen.knierman@asu.edu, E-mail: paul.scowen@asu.edu, E-mail: rolf.jansen@asu.edu, E-mail: pknezek@noao.edu, E-mail: ewehner@haverford.edu [Department of Astronomy, Haverford College, Haverford, PA 19041 (United States)

2012-04-10

394

Structural determinants in the second intracellular loop of the human follicle-stimulating hormone receptor are involved in G(s) protein activation.  

PubMed

In the present study, we analyzed the structural determinants present in the second intracellular loop (IL-2) of the human follicle-stimulating hormone (FSH) receptor (R) involved in G(s) protein-mediated signal transduction. Human embryonic kidney 293 (HEK-293) cells, stably expressing wild-type (Wt) human FSHR (HEK-293((+))), were transiently transfected with plasmids containing cDNAs encoding the entire IL-2 or several IL-2 sequences mutated in R467 (a residue located at the center of the conserved ERW motif in the glycoprotein hormone receptors), T470 (a potential site for phosphorylation by protein kinase-A and -C) or L477 (a residue conserved in all glycoprotein hormone receptors). Expression of the IL-2 Wt in HEK-293((+)) cells reduced the maximum FSH-stimulated cAMP production significantly by approximately 40%; similar results were observed with the R467A and R467K IL-2 mutants. The IL-2(R467H), IL-2(T470A), the triple R467A/T470A/L477A IL-2 mutant and the IL-2 of the oxytocin receptor (G(q/11)-coupled) had no effects on Wt FSHR-mediated intracellular signaling whereas the L477A mutation provoked a higher ( approximately 55%) inhibition of FSH-stimulated cAMP than the free, Wt IL-2. These results suggested a specific role of IL-2 residues in FSHR function. Site directed mutagenesis of the FSHR and the expression of resulting mutants in HEK-293 cells were performed in order to corroborate the effects of these substitutions. Expression of FSHR(R467H), FSHR(R467A) and FSHR(T470A) failed to mediate ligand-provoked G(s) protein activation, whereas the R467K mutant behaved as the Wt receptor. Interestingly, the expression of L477A, L477D and L477P FSHR mutants conferred elevated basal cAMP levels to HEK-293 cells. This study indicates that the IL-2 of the human FSHR possesses amino acid residues that are important for both coupling the receptor to the G(s) protein (R467 and T470) and maintaining the receptor molecule in an inactive conformation (L477). It appears that this particular intracellular domain may act as a conformational switch to produce the activation of G proteins as has been reported for the IL-2 of other G protein-coupled receptors. PMID:12039074

Timossi, Carlos; Maldonado, David; Vizcaíno, Andrea; Lindau-Shepard, Barbara; Conn, P Michael; Ulloa-Aguirre, Alfredo

2002-03-28

395

Three-dimensional architecture of actin filaments in Listeria monocytogenes comet tails  

PubMed Central

The intracellular bacterial pathogen Listeria monocytogenes is capable of remodelling the actin cytoskeleton of its host cells such that “comet tails” are assembled powering its movement within cells and enabling cell-to-cell spread. We used cryo-electron tomography to visualize the 3D structure of the comet tails in situ at the level of individual filaments. We have performed a quantitative analysis of their supramolecular architecture revealing the existence of bundles of nearly parallel hexagonally packed filaments with spacings of 12–13 nm. Similar configurations were observed in stress fibers and filopodia, suggesting that nanoscopic bundles are a generic feature of actin filament assemblies involved in motility; presumably, they provide the necessary stiffness. We propose a mechanism for the initiation of comet tail assembly and two scenarios that occur either independently or in concert for the ensuing actin-based motility, both emphasizing the role of filament bundling.

Jasnin, Marion; Asano, Shoh; Gouin, Edith; Hegerl, Reiner; Plitzko, Jurgen M.; Villa, Elizabeth; Cossart, Pascale; Baumeister, Wolfgang

2013-01-01

396

Investigations Relating to Fat-Tail Sheep.  

National Technical Information Service (NTIS)

The only Fat-tail type of sheep known to be present in the U.S. is the Karakul. In 1979 a small number of Karakul sheep were obtained and brought to the experimental flock maintained at San Angelo, Texas. The animals were obtained from range flocks in New...

M. Shelton R. Lewis T. Willingham G. C. Smith J. W. Savell

1986-01-01

397

Controlled Impact Demonstration (CID) tail camera video  

NASA Technical Reports Server (NTRS)

The Controlled Impact Demonstration (CID) was a joint research project by NASA and the FAA to test a survivable aircraft impact using a remotely piloted Boeing 720 aircraft. The tail camera movie is one shot running 27 seconds. It shows the impact from the perspective of a camera mounted high on the vertical stabilizer, looking forward over the fuselage and wings.

1984-01-01

398

Factors Influencing Radon Attenuation by Tailing Covers.  

National Technical Information Service (NTIS)

The US NRC, in its Generic Environmental Impact Statement on uranium milling has specified that the radon flux escaping a uranium mill tailings pile will be reduced to pCi/m exp 2 s by application of covering layers of soils and clays. These covers presen...

V. C. Rogers W. B. Silker

1981-01-01

399

VideoLab: Heads and Tails  

NSDL National Science Digital Library

The flatworms known as planaria are proverbial for their ability to regenerate a head or tail properly when amputated (first clip in movie). But how does the organism "know" which end to regenerate? Gurley et al. found an answer in a molecular "switch", beta-catenin, a protein that regulates a variety of cell processes during development.

Kyle A. Gurley (Howard Hughes Medical Institute, University of Utah School of Medicine;Department of Neurobiology and Anatomy); Jochen C. Rink (Howard Hughes Medical Institute, University of Utah School of Medicine;Department of Neurobiology and Anatomy); Alejandro Sánchez Alvarado (Howard Hughes Medical Institute, University of Utah School of Medicine;Department of Neurobiology and Anatomy)

2008-01-18

400

Tail-Wagging Event in Comet Austin.  

National Technical Information Service (NTIS)

On the morning of 21 May 1990, a sequence of images of Comet Austin was obtained in the light of H2O+. The filter was centered at 602.5 nm with FWHM of 5.0 nm. At least two waves were followed out through the main ion tail structure. During the course of ...

D. A. Klinglesmith M. B. Niedner R. J. Oliversen D. Westpfahl

1990-01-01

401

Mine Waste Technology Program Electrochemical Tailings Cover  

EPA Science Inventory

This report summarizes the results of Mine Waste Technology Program (MWTP) Activity III, Project 40, Electrochemical Tailings Cover, funded by the U.S. Environmental Protection Agency (EPA) and jointly administered by EPA and the U.S. Department of Energy (DOE). MSE Technology A...

402

The mine tailing accident in Aznalcollar  

Microsoft Academic Search

Massive amounts of acidic waters and mud (pH?3) containing toxic metals such as zinc, lead, arsenic, copper, antimony, cobalt, thallium, bismuth, cadmium, silver, mercury and selenium were released in the surroundings of Doñana Park as a consequence of the mine tailings spill accident in Aznalcollar (SW Spain). This introductory paper describes the main characteristics of Doñana Park, the mine activities

Joan O Grimalt; Miguel Ferrer; Enrique Macpherson

1999-01-01

403

The Mechanical Properties of Rat Tail Tendon  

Microsoft Academic Search

The load-strain and stress-relaxation behavior of wet rat tail tendon has been examined with respect to the parameters strain, rate of strain- ing, and temperature. It is found that this mechanical behavior is reproducible after resting tile tendon for a few minutes after each extension so long as the strain does not exceed about 4 per cent. If this strain

BERNARD J. RIGBY; OHN D. SPIKES; HENRY EYRING

1959-01-01

404

Constraining Dark Halo Potentials with Tidal Tails  

Microsoft Academic Search

Massive and extended dark halos can inhibit the formation of long tidal tails in galaxy collisions. We examine this effect using an extensive survey of simulations with different dark halo potentials to constrain halo properties of interacting galaxies. These constraints are compared to other observational limits and theoretical predictions of halo structure. The dark halos predicted by $\\\\Omega=1$ cosmological models

J. Dubinski; L. Hernquist; J. C. Mihos

1998-01-01

405

Dispersal in female white-tailed deer  

USGS Publications Warehouse

Seven of 35 yearling female white-tailed deer (Odocoileus virginianus) in a migratory herd in northeastern Minnesota dispersed 18-168 km from natal ranges during late May through June. Dispersal as a proximate event appears voluntary and independent of deer density.

Nelson, M. E.; Mech, L. D.

1992-01-01

406

Radiological hazards of uranium mill tailings piles  

Microsoft Academic Search

This paper examines reasons for the radiological health problems associated with the front end of the nuclear fuel cycle. The increases of radioactivity in the general environment attributable to uranium mill tailings are small but never ending. Sources of radiation - mainly particulate matter and radon gas - are discussed. Management of the piles seems to provide the only viable

G. A. Watford; J. A. Jr. Wethington

1981-01-01

407

Analysis of three-dimensional kinematics of carp tail fin  

NASA Astrophysics Data System (ADS)

In this paper, a test based on the wavelet transform for instantaneous three dimensional (3D) Carp tail fin profile measurements and analysis the kinematics of Carp tail fin method was proposed to understand the function of the tail fin. This experiment method is used in cruising carp. Projecting a moiré fringes onto a tail fin, the deformed fringe pattern containing 3D information was produced and varied with the movement of tail fin. The time-sequence deformed fringe pattern images were captured by a high speed camera. By wavelet transform profilometry, the tail fin movements were really reconstructed. On this basis, the kinematics parameter of tail fin was analyses. Experimental results indicate that the 3D profile of tail fin was varied during the tail-beat cycle. Analysis of tail kinematics suggests that, at a swimming speed 0.5Ls-1, the tail beat frequency is 1.42Hz and the dorsal lobe of the tail undergoes a 15.6% greater lateral excursion than does the ventral lobe. The timing of maximal lateral excursion was different at different location of tail fin.

Jiang, Ming; Zhang, Shu; He, Xiaoyuan

2009-12-01

408