Science.gov

Sample records for additional links lead

  1. 40 CFR 51.117 - Additional provisions for lead.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Additional provisions for lead. 51.117... Additional provisions for lead. In addition to other requirements in §§ 51.100 through 51.116 the following requirements apply to lead. To the extent they conflict, there requirements are controlling over those of...

  2. 40 CFR 51.117 - Additional provisions for lead.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Additional provisions for lead. 51.117... Additional provisions for lead. In addition to other requirements in §§ 51.100 through 51.116 the following requirements apply to lead. To the extent they conflict, there requirements are controlling over those of...

  3. 40 CFR 51.117 - Additional provisions for lead.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 2 2013-07-01 2013-07-01 false Additional provisions for lead. 51.117... Additional provisions for lead. In addition to other requirements in §§ 51.100 through 51.116 the following requirements apply to lead. To the extent they conflict, there requirements are controlling over those of...

  4. 40 CFR 51.117 - Additional provisions for lead.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 2 2011-07-01 2011-07-01 false Additional provisions for lead. 51.117... Additional provisions for lead. In addition to other requirements in §§ 51.100 through 51.116 the following requirements apply to lead. To the extent they conflict, there requirements are controlling over those of...

  5. 40 CFR 51.117 - Additional provisions for lead.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 2 2014-07-01 2014-07-01 false Additional provisions for lead. 51.117... Additional provisions for lead. In addition to other requirements in §§ 51.100 through 51.116 the following requirements apply to lead. To the extent they conflict, there requirements are controlling over those of...

  6. Zinc halogen battery electrolyte composition with lead additive

    DOEpatents

    Henriksen, Gary L.

    1981-01-01

    This disclosure relates to a zinc halogen battery electrolyte composition containing an additive providing improved zinc-on-zinc recyclability. The improved electrolyte composition involves the use of a lead additive to inhibit undesirable irregular plating and reduce nodular or dendritic growth on the electrode surface. The lead-containing electrolyte composition of the present invention appears to influence not only the morphology of the base plate zinc, but also the morphology of the zinc-on-zinc replate. In addition, such lead-containing electrolyte compositions appear to reduce hydrogen formation.

  7. Eliminating antibody polyreactivity through addition of N-linked glycosylation.

    PubMed

    Chuang, Gwo-Yu; Zhang, Baoshan; McKee, Krisha; O'Dell, Sijy; Kwon, Young Do; Zhou, Tongqing; Blinn, Julie; Lloyd, Krissey; Parks, Robert; Von Holle, Tarra; Ko, Sung-Youl; Kong, Wing-Pui; Pegu, Amarendra; Wang, Keyun; Baruah, Kavitha; Crispin, Max; Mascola, John R; Moody, M Anthony; Haynes, Barton F; Georgiev, Ivelin S; Kwong, Peter D

    2015-06-01

    Antibody polyreactivity can be an obstacle to translating a candidate antibody into a clinical product. Standard tests such as antibody binding to cardiolipin, HEp-2 cells, or nuclear antigens provide measures of polyreactivity, but its causes and the means to resolve are often unclear. Here we present a method for eliminating antibody polyreactivity through the computational design and genetic addition of N-linked glycosylation near known sites of polyreactivity. We used the HIV-1-neutralizing antibody, VRC07, as a test case, since efforts to increase VRC07 potency at three spatially distinct sites resulted in enhanced polyreactivity. The addition of N-linked glycans proximal to the polyreactivity-enhancing mutations at each of the spatially distinct sites resulted in reduced antibody polyreactivity as measured by (i) anti-cardiolipin ELISA, (ii) Luminex AtheNA Multi-Lyte ANA binding, and (iii) HEp-2 cell staining. The reduced polyreactivity trended with increased antibody concentration over time in mice, but not with improved overall protein stability as measured by differential scanning calorimetry. Moreover, glycan proximity to the site of polyreactivity appeared to be a critical factor. The results provide evidence that antibody polyreactivity can result from local, rather than global, features of an antibody and that addition of N-linked glycosylation can be an effective approach to reducing antibody polyreactivity.

  8. Cross-linked biopolymer bundles: Cross-link reversibility leads to cooperative binding/unbinding phenomena

    NASA Astrophysics Data System (ADS)

    Vink, Richard L. C.; Heussinger, Claus

    2012-01-01

    We consider a biopolymer bundle consisting of filaments that are cross-linked together. The cross-links are reversible: they can dynamically bind and unbind adjacent filament pairs as controlled by a binding enthalpy. The bundle is subjected to a bending deformation and the corresponding distribution of cross-links is measured. For a bundle consisting of two filaments, upon increasing the bending amplitude, a first-order transition is observed. The transition is from a state where the filaments are tightly coupled by many bound cross-links, to a state of nearly independent filaments with only a few bound cross-links. For a bundle consisting of more than two filaments, a series of first-order transitions is observed. The transitions are connected with the formation of an interface between regions of low and high cross-link densities. Combining umbrella sampling Monte Carlo simulations with analytical calculations, we present a detailed picture of how the competition between cross-link shearing and filament stretching drives the transitions. We also find that, when the cross-links become soft, collective behavior is not observed: the cross-links then unbind one after the other leading to a smooth decrease of the average cross-link density.

  9. Linking geology and health sciences to assess childhood lead poisoning from artisanal gold mining in Nigeria

    USGS Publications Warehouse

    Plumlee, Geoffrey S.; Durant, James T.; Morman, Suzette A.; Neri, Antonio; Wolf, Ruth E.; Dooyema, Carrie A.; Hageman, Philip L.; Lowers, Heather; Fernette, Gregory L.; Meeker, Gregory P.; Benzel, William M.; Driscoll, Rhonda L.; Berry, Cyrus J.; Crock, James G.; Goldstein, Harland L.; Adams, Monique; Bartrem, Casey L.; Tirima, Simba; Behrooz, Behbod; von Lindern, Ian; Brown, Mary Jean

    2013-01-01

    Background: In 2010, Médecins Sans Frontières discovered a lead poisoning outbreak linked to artisanal gold processing in northwestern Nigeria. The outbreak has killed approximately 400 young children and affected thousands more. Objectives: Our aim was to undertake an interdisciplinary geological- and health-science assessment to clarify lead sources and exposure pathways, identify additional toxicants of concern and populations at risk, and examine potential for similar lead poisoning globally. Methods: We applied diverse analytical methods to ore samples, soil and sweep samples from villages and family compounds, and plant foodstuff samples. Results: Natural weathering of lead-rich gold ores before mining formed abundant, highly gastric-bioaccessible lead carbonates. The same fingerprint of lead minerals found in all sample types confirms that ore processing caused extreme contamination, with up to 185,000 ppm lead in soils/sweep samples and up to 145 ppm lead in plant foodstuffs. Incidental ingestion of soils via hand-to-mouth transmission and of dusts cleared from the respiratory tract is the dominant exposure pathway. Consumption of water and foodstuffs contaminated by the processing is likely lesser, but these are still significant exposure pathways. Although young children suffered the most immediate and severe consequences, results indicate that older children, adult workers, pregnant women, and breastfed infants are also at risk for lead poisoning. Mercury, arsenic, manganese, antimony, and crystalline silica exposures pose additional health threats. Conclusions: Results inform ongoing efforts in Nigeria to assess lead contamination and poisoning, treat victims, mitigate exposures, and remediate contamination. Ore deposit geology, pre-mining weathering, and burgeoning artisanal mining may combine to cause similar lead poisoning disasters elsewhere globally.

  10. Linking Geological and Health Sciences to Assess Childhood Lead Poisoning from Artisanal Gold Mining in Nigeria

    PubMed Central

    Durant, James T.; Morman, Suzette A.; Neri, Antonio; Wolf, Ruth E.; Dooyema, Carrie A.; Hageman, Philip L.; Lowers, Heather A.; Fernette, Gregory L.; Meeker, Gregory P.; Benzel, William M.; Driscoll, Rhonda L.; Berry, Cyrus J.; Crock, James G.; Goldstein, Harland L.; Adams, Monique; Bartrem, Casey L.; Tirima, Simba; Behbod, Behrooz; von Lindern, Ian; Brown, Mary Jean

    2013-01-01

    Background: In 2010, Médecins Sans Frontières discovered a lead poisoning outbreak linked to artisanal gold processing in northwestern Nigeria. The outbreak has killed approximately 400 young children and affected thousands more. Objectives: Our aim was to undertake an interdisciplinary geological- and health-science assessment to clarify lead sources and exposure pathways, identify additional toxicants of concern and populations at risk, and examine potential for similar lead poisoning globally. Methods: We applied diverse analytical methods to ore samples, soil and sweep samples from villages and family compounds, and plant foodstuff samples. Results: Natural weathering of lead-rich gold ores before mining formed abundant, highly gastric-bioaccessible lead carbonates. The same fingerprint of lead minerals found in all sample types confirms that ore processing caused extreme contamination, with up to 185,000 ppm lead in soils/sweep samples and up to 145 ppm lead in plant foodstuffs. Incidental ingestion of soils via hand-to-mouth transmission and of dusts cleared from the respiratory tract is the dominant exposure pathway. Consumption of water and foodstuffs contaminated by the processing is likely lesser, but these are still significant exposure pathways. Although young children suffered the most immediate and severe consequences, results indicate that older children, adult workers, pregnant women, and breastfed infants are also at risk for lead poisoning. Mercury, arsenic, manganese, antimony, and crystalline silica exposures pose additional health threats. Conclusions: Results inform ongoing efforts in Nigeria to assess lead contamination and poisoning, treat victims, mitigate exposures, and remediate contamination. Ore deposit geology, pre-mining weathering, and burgeoning artisanal mining may combine to cause similar lead poisoning disasters elsewhere globally. PMID:23524139

  11. Evaluation of lead anode reactions in acid sulfate electrolytes. 1: Lead alloys with cobalt additives

    SciTech Connect

    Yu, P.; O`Keefe, T.J.

    1999-04-01

    Lead alloys, such as lead-calcium-tin and lead-silver, are the primary insoluble anodes used in the electrowinning of metals. While some difficulties are encountered in their use, there is no obvious replacement that is economically and technically competitive. Two of the specific problems with lead include decreased cathode purity due to incorporation from corrosion products and the relatively high overpotential which increases cell voltage. To gain an improved understanding of the fundamental behavior of lead anodes, the polarization behavior of six different alloys in sulfuric acid was evaluated. Some tests were also made with Co(II) in the acid sulfate electrolyte. Notable differences were found in the multiple activation-passivation cycles, stability, and relative activity for oxygen evolution for the alloys, and the relative trends in behavior were established. Electrochemical impedance spectroscopy studies were also conducted at selected potentials. Overall, the data show that the electrochemical response, particularly the degree of polarization for the oxygen evolution reaction, of the lead alloy anodes are dependent on the surface phases and structures present. The ability to depolarize the anode reaction using Co(II) was particularly sensitive to the lead composition.

  12. A Public Opinion Survey on Correctional Education: Does Additional Information on Efficacy Lead to Additional Support?

    ERIC Educational Resources Information Center

    Waterland, Keri Lynn

    2009-01-01

    Though much research has been done on the efficacy of correctional education on reducing recidivism rates for prison inmates, there is little research on the effect that information about the efficacy of correctional education has on public opinion. This study examined whether providing additional information regarding the efficacy of correctional…

  13. Linking cases of illegal shootings of the endangered California condor using stable lead isotope analysis.

    PubMed

    Finkelstein, Myra E; Kuspa, Zeka E; Welch, Alacia; Eng, Curtis; Clark, Michael; Burnett, Joseph; Smith, Donald R

    2014-10-01

    Lead poisoning is preventing the recovery of the critically endangered California condor (Gymnogyps californianus) and lead isotope analyses have demonstrated that ingestion of spent lead ammunition is the principal source of lead poisoning in condors. Over an 8 month period in 2009, three lead-poisoned condors were independently presented with birdshot embedded in their tissues, evidencing they had been shot. No information connecting these illegal shooting events existed and the timing of the shooting(s) was unknown. Using lead concentration and stable lead isotope analyses of feathers, blood, and recovered birdshot, we observed that: i) lead isotope ratios of embedded shot from all three birds were measurably indistinguishable from each other, suggesting a common source; ii) lead exposure histories re-constructed from feather analysis suggested that the shooting(s) occurred within the same timeframe; and iii) two of the three condors were lead poisoned from a lead source isotopically indistinguishable from the embedded birdshot, implicating ingestion of this type of birdshot as the source of poisoning. One of the condors was subsequently lead poisoned the following year from ingestion of a lead buckshot (blood lead 556 µg/dL), illustrating that ingested shot possess a substantially greater lead poisoning risk compared to embedded shot retained in tissue (blood lead ~20 µg/dL). To our knowledge, this is the first study to use lead isotopes as a tool to retrospectively link wildlife shooting events.

  14. Linking cases of illegal shootings of the endangered California condor using stable lead isotope analysis.

    PubMed

    Finkelstein, Myra E; Kuspa, Zeka E; Welch, Alacia; Eng, Curtis; Clark, Michael; Burnett, Joseph; Smith, Donald R

    2014-10-01

    Lead poisoning is preventing the recovery of the critically endangered California condor (Gymnogyps californianus) and lead isotope analyses have demonstrated that ingestion of spent lead ammunition is the principal source of lead poisoning in condors. Over an 8 month period in 2009, three lead-poisoned condors were independently presented with birdshot embedded in their tissues, evidencing they had been shot. No information connecting these illegal shooting events existed and the timing of the shooting(s) was unknown. Using lead concentration and stable lead isotope analyses of feathers, blood, and recovered birdshot, we observed that: i) lead isotope ratios of embedded shot from all three birds were measurably indistinguishable from each other, suggesting a common source; ii) lead exposure histories re-constructed from feather analysis suggested that the shooting(s) occurred within the same timeframe; and iii) two of the three condors were lead poisoned from a lead source isotopically indistinguishable from the embedded birdshot, implicating ingestion of this type of birdshot as the source of poisoning. One of the condors was subsequently lead poisoned the following year from ingestion of a lead buckshot (blood lead 556 µg/dL), illustrating that ingested shot possess a substantially greater lead poisoning risk compared to embedded shot retained in tissue (blood lead ~20 µg/dL). To our knowledge, this is the first study to use lead isotopes as a tool to retrospectively link wildlife shooting events. PMID:25173094

  15. Linking source and effect: resuspended soil lead, air lead, and children's blood lead levels in Detroit, Michigan.

    PubMed

    Zahran, Sammy; Laidlaw, Mark A S; McElmurry, Shawn P; Filippelli, Gabriel M; Taylor, Mark

    2013-03-19

    This study evaluates atmospheric concentrations of soil and Pb aerosols, and blood lead levels (BLLs) in 367839 children (ages 0-10) in Detroit, Michigan from 2001 to 2009 to test a hypothesized soil → air dust → child pathway of contemporary Pb risk. Atmospheric soil and Pb show near-identical seasonal properties that match seasonal variation in children's BLLs. Resuspended soil appears to be a significant underlying source of atmospheric Pb. A 1% increase in the amount of resuspended soil results in a 0.39% increase in the concentration of Pb in the atmosphere (95% CI, 0.28 to 0.50%). In turn, atmospheric Pb significantly explains age-dependent variation in child BLLs. Other things held equal, a change of 0.0069 μg/m(3) in atmospheric Pb increases BLL of a child 1 year of age by 10%, while approximately 3 times the concentration of Pb in air (0.023 μg/m(3)) is required to induce the same increase in BLL of a child 7 years of age. Similarly, a 0.0069 μg/m(3) change in air Pb increases the odds of a child <1 year of age having a BLL ≥ 5 μg/dL by a multiplicative factor of 1.32 (95% CI, 1.26 to 1.37). Overall, the resuspension of Pb contaminated soil explains observed seasonal variation in child BLLs.

  16. The addition of red lead to flat plate and tubular valve regulated miners cap lamp lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Ferg, E. E.; Loyson, P.; Poorun, A.

    The study looked at the use of red lead in the manufacturing of valve regulated lead acid (VRLA) miners cap lamp (MCL) batteries that were made with either flat plate or tubular positive electrodes. A problem with using only grey oxide in the manufacture of thick flat plate or tubular electrodes is the poor conversion of the active material to the desired lead dioxide. The addition of red lead to the initial starting material improves the formation efficiency but is considerably more expensive thereby increasing the cost of manufacturing. The study showed that by carefully controlling the formation conditions in terms of the voltage and temperature of a battery, good capacity performance can be achieved for cells made with flat plate electrodes that contain up to 25% red lead. The small amount of red lead in the active cured material reduces the effect of electrode surface sulphate formation and allows the battery to achieve its rated capacity within the first few cycles. Batteries made with flat plate positive electrodes that contained more that 50% red lead showed good initial capacity but had poor structural active material bonding. The study showed that MCL batteries made with tubular positive electrodes that contained less than 75% red lead resulted in a poorly formed electrode with limited capacity utilization. Pickling and soaking times of the tubular electrodes should be kept at a minimum thereby allowing higher active material utilization during subsequent capacity cycling. The study further showed that it is beneficial to use higher formation rates in order to reduce manufacturing time and to improve the active material characteristics.

  17. The use of nanometer tetrabasic lead sulfate as positive active material additive for valve regulated lead-acid battery

    NASA Astrophysics Data System (ADS)

    Lang, Xiaoshi; Wang, Dianlong; Hu, Chiyu; Tang, Shenzhi; Zhu, Junsheng; Guo, Chenfeng

    2014-12-01

    Conventional tetrabasic lead sulfate used as positive active material additive shows the results of the low effective lead dioxide conversion rate due to the large grain size and crossed the crystal structure. In this paper, we study on a type of nanometer tetrabasic lead sulfate. Through the XRD and SEM test and Material Studio software calculation, the purity of tetrabasic lead sulfate is very high, the grain size of the nanometer 4BS is almost unanimous, and can be controlled below 200 nm. When charged and discharged in 1.75 V-2.42 V with the current density of 40 mA g-1, 80 mA g-1 and 160 mA g-1, the effective lead dioxide conversion rate of nanometer 4BS after formation can achieve to 83.48%, 71.42%, and 66.96%. Subsequently, the nanometer 4BS as additive is added to positive paste of lead-acid battery. When the batteries are tested galvanostatically between 1.75 V and 2.42 V at 0.25 C charge and 0.5 C discharge rates at room temperature. The ratio of adding nanometer 4BS is 0%, 1% and 4% and the initial discharge specific capacities are 60 mAh g-1, 65 mAh g-1 and 68 mAh g-1. After 80 cycles, the initial discharge capacity of positive active material with 1% nanometer 4BS decreased less than 10%, while adding 4% nanometer 4BS, the initial discharge capacity doesn't decrease obviously.

  18. Linking cases of illegal shootings of the endangered California condor using stable lead isotope analysis

    SciTech Connect

    Finkelstein, Myra E.; Kuspa, Zeka E.; Welch, Alacia; Eng, Curtis; Clark, Michael; Burnett, Joseph; Smith, Donald R.

    2014-10-15

    Lead poisoning is preventing the recovery of the critically endangered California condor (Gymnogyps californianus) and lead isotope analyses have demonstrated that ingestion of spent lead ammunition is the principal source of lead poisoning in condors. Over an 8 month period in 2009, three lead-poisoned condors were independently presented with birdshot embedded in their tissues, evidencing they had been shot. No information connecting these illegal shooting events existed and the timing of the shooting(s) was unknown. Using lead concentration and stable lead isotope analyses of feathers, blood, and recovered birdshot, we observed that: i) lead isotope ratios of embedded shot from all three birds were measurably indistinguishable from each other, suggesting a common source; ii) lead exposure histories re-constructed from feather analysis suggested that the shooting(s) occurred within the same timeframe; and iii) two of the three condors were lead poisoned from a lead source isotopically indistinguishable from the embedded birdshot, implicating ingestion of this type of birdshot as the source of poisoning. One of the condors was subsequently lead poisoned the following year from ingestion of a lead buckshot (blood lead 556 µg/dL), illustrating that ingested shot possess a substantially greater lead poisoning risk compared to embedded shot retained in tissue (blood lead ∼20 µg/dL). To our knowledge, this is the first study to use lead isotopes as a tool to retrospectively link wildlife shooting events. - Highlights: • We conducted a case-based analysis of illegal shootings of California condors. • Blood and feather Pb isotopes were used to reconstruct the illegal shooting events. • Embedded birdshot from the three condors had the same Pb isotope ratios. • Feather and blood Pb isotopes indicated that the condors were shot in a common event. • Ingested shot causes substantially greater lead exposure compared to embedded shot.

  19. Leading Change in Tissue Viability Best Practice: An Action Learning Programme for Link Nurse Practitioners

    ERIC Educational Resources Information Center

    Kellie, Jean; Henderson, Eileen; Milsom, Brian; Crawley, Hayley

    2010-01-01

    This account of practice reports on an action learning initiative designed and implemented in partnership between a regional NHS Acute Trust and a UK Business School. The central initiative was the implementation of an action learning programme entitled "Leading change in tissue viability best practice: a development programme for Link Nurse…

  20. Macrocyclic amine-linked oligocarbazole hollow microspheres: facile synthesis and efficient lead sorbents.

    PubMed

    Liao, Yaozu; Cai, Sisi; Huang, Shaojun; Wang, Xia; Faul, Charl F J

    2014-11-01

    Novel macrocyclic amine-linked oligocarbazole hollow microspheres are synthesized via a one-step oxidative method in aqueous solution. Upon altering the oxidants and acidic media, the average diameters of the obtained hollow microspheres are tunable from 0.23 to 2.0 μm. With attractive amine and carbazole functionalities, exposed surface area, thermostability, and photoluminescent properties, the amine-linked oligocarbazole hollow microspheres are directly assembled to yield heavy metal sorbents with excellent selectivity and recyclability, shown to efficiently remove lead from contaminated water.

  1. Does Visual Impairment Lead to Additional Disability in Adults with Intellectual Disabilities?

    ERIC Educational Resources Information Center

    Evenhuis, Heleen M.; Sjoukes, L.; Koot, H. M.; Kooijman, A. C.

    2009-01-01

    Background: This study addresses the question to what extent visual impairment leads to additional disability in adults with intellectual disabilities (ID). Method: In a multi-centre cross-sectional study of 269 adults with mild to profound ID, social and behavioural functioning was assessed with observant-based questionnaires, prior to expert…

  2. Joint analysis of tightly linked SNPs in screening step of genome-wide association studies leads to increased power

    PubMed Central

    Becker, Tim; Herold, Christine

    2009-01-01

    Recent developments in genome-wide association studies (GWAS) have lead to the localization of disease genes for many complex diseases. The scrutiny of the respective publications reveals, first, that statistical analysis is restricted typically to single-marker analysis in the first step, and that, second, the presence of multiple, independently associated SNPs within the same linkage disequilibrium (LD) region is a common phenomenon. Motivated by this observation, we show through a power simulation study that a simultaneous analysis of tightly linked SNPs in the initial GWAS analysis step would lead to increased power, when compared with that in single-marker analysis. This is true for all the three approaches we considered (implementations in BEAGLE, FAMHAP and UNPHASED). The best performance was obtained using a two-marker haplotype analysis. In conclusion, we would expect additional gene findings for re-analyzing successful GWAS with a multi-marker approach. PMID:19223937

  3. Non-pairwise additivity of the leading-order dispersion energy

    SciTech Connect

    Hollett, Joshua W.

    2015-02-28

    The leading-order (i.e., dipole-dipole) dispersion energy is calculated for one-dimensional (1D) and two-dimensional (2D) infinite lattices, and an infinite 1D array of infinitely long lines, of doubly occupied locally harmonic wells. The dispersion energy is decomposed into pairwise and non-pairwise additive components. By varying the force constant and separation of the wells, the non-pairwise additive contribution to the dispersion energy is shown to depend on the overlap of density between neighboring wells. As well separation is increased, the non-pairwise additivity of the dispersion energy decays. The different rates of decay for 1D and 2D lattices of wells is explained in terms of a Jacobian effect that influences the number of nearest neighbors. For an array of infinitely long lines of wells spaced 5 bohrs apart, and an inter-well spacing of 3 bohrs within a line, the non-pairwise additive component of the leading-order dispersion energy is −0.11 kJ mol{sup −1} well{sup −1}, which is 7% of the total. The polarizability of the wells and the density overlap between them are small in comparison to that of the atomic densities that arise from the molecular density partitioning used in post-density-functional theory (DFT) damped dispersion corrections, or DFT-D methods. Therefore, the nonadditivity of the leading-order dispersion observed here is a conservative estimate of that in molecular clusters.

  4. PREDICTING LEAD DISSOLUTION IN DRINKING WATER DISTRIBUTION SYSTEMS: EFFECT OF FLUORIDE ADDITIVES ON LEAD SOLUBILITY AND CORROSION

    EPA Science Inventory

    Many water systems have encountered difficulties in meeting the action levels established by the Lead and Copper Rule. Several chemical parameters contribute to the corrosion of lead plumbing and may influence the nature of the passivating films formed on distribution materials....

  5. Polymer-additive extraction via pressurized fluids and organic solvents of variously cross-linked poly(methylmethacrylates).

    PubMed

    Nazem, N; Taylor, L T

    2002-04-01

    Variously cross-linked poly(methylmethacrylates) (PMMAs) are synthesized with three additives incorporated at theoretically 1000 microg of the additive per gram of prepared polymer. The additives are Irganox 1010, Irganox 1076, and Irgafos 168. The in-house" synthesized polyacrylates are then subjected to supercritical fluid extraction (SFE) to determine if additive recovery is a function of percent cross-linking. Although considerable work in this regard has been performed with non-cross-linked polyolefins, the literature is lacking regarding polyacrylates. Some additive degradation apparently occurs during the synthesis, as judged by the increased complexity of the extract high-performance liquid chromatographic trace and the low percent recoveries observed especially for the Irganoxes. For low polymer cross-linking (1%), it appears that both PMMA synthetic reproducibility and readily observed polymer swelling during SFE are serious issues that adversely affect additive percent recovery and precision of results. Higher percent cross-linking yields more consistent analytical data than low percent cross-linking, even though the amount of additive extracted in all PMMA samples (regardless of cross-linking percentage) is essentially the same whether the extraction is via SFE or liquid-solid extraction with methylene chloride. Results for comparably cross-linked poly(ethylmethacrylate) and poly(butylmethacrylate) are similar to PMMA.

  6. Carbodiimide induced cross-linking, ligand addition, and degradation in gelatin.

    PubMed

    Cammarata, Christopher R; Hughes, Mitchell E; Ofner, Clyde M

    2015-03-01

    The water-soluble carbodiimide, 1-ethyl-3-(3-(dimethylaminopropyl)-carbodiimide (EDC) is widely used in protein chemistry. We used EDC-induced gelatin cross-linking as a model for amide bond formation to resolve reaction ambiguities with common variables of buffers, gelatin concentration, and pH. Percentage changes in SEC high molecular weight peak areas were used to follow the reactions. Differences in reaction rate and extent were observed with four commonly used buffers, while differences in extent were observed for commonly used concentrations and pH. We also investigated an anhydride mechanism for aqueous EDC-induced amide bond formation that has received little attention since its proposal in 1995. Gelatin carboxyl groups had a synergistic role during the addition of hydrazine to corroborate the anhydride formation between carboxyl groups. EDC-induced degradation of gelatin was investigated using percentage changes in SEC low molecular weight peak areas. The degradation occurred in excess EDC at neutral to alkaline pH and was enhanced substantially when reacting amino groups were not available. A mechanism of EDC-induced gelatin degradation is proposed and designated the extended Khorana mechanism. This EDC side reaction has the potential to occur in peptides and proteins under similar conditions.

  7. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  8. Displacement Addition on Linking Extensional Fault Arrays in the Canyonlands Graben, Utah

    NASA Astrophysics Data System (ADS)

    Commins, D. C.; Gupta, S.; Cartwright, J. A.; Phillips, W. M.

    2003-12-01

    immediately following linkage, and recovery to a standard D-l profile is gained through this process. (5) The locus of displacement accumulation is not fixed in time; the central fault segment does not always experience the greatest displacement enhancement. Preliminary results of cosmogenic 10Be exposure dating of bedrock with quartz from the Permian Cedar Mesa Sandstone indicate recent (<10ka) timing of rapid displacement addition on linking faults.

  9. AlNiYCo Amorphous Matrix Composites Induced by Bismuth and Lead Additions

    NASA Astrophysics Data System (ADS)

    He, Jie; Jiang, Hongxiang; Zhao, Jiuzhou; Mattern, Norbert; Eckert, Jürgen

    2011-12-01

    (Al85Ni5Y8Co2)98Bi2 and (Al85Ni5Y8Co2)98(Bi50Pb50)2 alloys are rapidly solidified using the single-roller melt-spinning method. Al85Ni5Y8Co2 amorphous matrix composites containing faceted BiY particles are synthesized by the liquid-solid reaction between added bismuth and constituents of the molten Al-Ni-Y-Co glass-forming alloy. The microstructure of the rapidly quenched (Al85Ni5Y8Co2)98(Bi50Pb50)2 multiphase composites consists of Al-based amorphous matrix and crystalline Pb-rich and BiY particles. The Pb-rich particles stem from liquid-liquid and monotectic reactions induced by lead addition. The phase constitution and microstructure are investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The reaction-induced crystalline BiY and Pb-rich particles are uniformly distributed in the amorphous matrix. The microstructure formation of the rapidly quenched alloys was discussed.

  10. Lead

    MedlinePlus

    ... Lead Share Facebook Twitter Google+ Pinterest Contact Us Lead Poisoning is Preventable If your home was built before ... of the RRP rule. Read more . Learn about Lead Poisoning Prevention Week . Report Uncertified Contractors and Environmental Violations ...

  11. Insulin resistance and alterations in angiogenesis: additive insults that may lead to preeclampsia.

    PubMed

    Thadhani, Ravi; Ecker, Jeffrey L; Mutter, Walter P; Wolf, Myles; Smirnakis, Karen V; Sukhatme, Vikas P; Levine, Richard J; Karumanchi, S Ananth

    2004-05-01

    Altered angiogenesis and insulin resistance, which are intimately related at a molecular level, characterize preeclampsia. To test if an epidemiological interaction exists between these two alterations, we performed a nested case-control study of 28 women who developed preeclampsia and 57 contemporaneous controls. Serum samples at 12 weeks of gestation were measured for sex hormone binding globulin (SHBG; low levels correlate with insulin resistance) and placental growth factor (PlGF; a proangiogenic molecule). Compared with controls, women who developed preeclampsia had lower serum levels of SHBG (208+/-116 versus 256+/-101 nmol/L, P=0.05) and PlGF (16+/-14 versus 67+/-150 pg/mL, P<0.001), and in multivariable analysis, women with serum levels of PlGF < or =20 pg/mL had an increased risk of developing preeclampsia (odds ratio [OR] 7.6, 95% CI 1.4 to 38.4). Stratified by levels of serum SHBG (< or =175 versus >175 mg/dL), women with low levels of SHBG and PlGF had a 25.5-fold increased risk of developing preeclampsia (P=0.10), compared with 1.8 (P=0.38) among women with high levels of SHBG and low levels of PlGF. Formal testing for interaction (PlGFxSHBG) was significant (P=0.02). In a model with 3 (n-1) interaction terms (high PlGF and high SHBG, reference), the risk for developing preeclampsia was as follows: low PlGF and low SHBG, OR 15.1, 95% CI 1.7 to 134.9; high PlGF and low SHBG, OR 4.1, 95% CI 0.45 to 38.2; low PlGF and high SHBG, OR 8.7, 95% CI 1.2 to 60.3. Altered angiogenesis and insulin resistance are additive insults that lead to preeclampsia.

  12. State of lead additive use, 1995: Two gasoline systems in Latin America, Part I

    SciTech Connect

    1995-09-26

    Unleaded gasoline in Latin America is taking market share away from leaded as automobile manufacturers, refiners, marketers, and consumers accommodate the phase-down of lead. The urgency of moving to unleaded gasoline is based on many factors as each country has a different viewpoint and a different environmental protection vision. This issue of Energy Detente examines the current phase of the ongoing lead phase-down in Latin America.

  13. Lead

    MedlinePlus

    ... obvious symptoms, it frequently goes unrecognized. CDC’s Childhood Lead Poisoning Prevention Program is committed to the Healthy People ... Lead Levels Information for Parents Tips for preventing lead poisoning About Us Overview of CDC’s Childhood Lead Poisoning ...

  14. Electrodeposition of lustrous tin-lead alloys in acidic electrolytes with organic additives

    SciTech Connect

    Selivanova, G.A.; Maksimenko, S.A.; Tyutina, K.M.

    1994-09-01

    Galvanic coatings based on tin-lead alloys are mainly used in radio-engineering and electronic industries to prepare certain products, including printed-circuit boards, for soldering. To improve ecological safety of the proces, the authors studied a new electrolyte for depositing a tin-lead alloy based on nontoxic and abundant perchloric acid, as well as electrolytes based on mono- and trichloroacetic acids.

  15. Effect of additives on the digestibility of corn stover solids following pretreatment by leading technologies.

    PubMed

    Kumar, Rajeev; Wyman, Charles E

    2009-04-15

    Bovine serum albumin (BSA), Tween-20, and polyethylene glycol (PEG6000) were added to washed corn stover solids produced by ammonia fiber expansion (AFEX), ammonia recycled percolation (ARP), dilute sulfuric acid (DA), lime, controlled pH, and sulfur dioxide (SO(2)) pretreatments and to untreated corn stover (UT) and pure Avicel glucan prior to adding cellulase supplemented with beta-glucosidase at an activity ratio of 1:2/g and a moderate enzyme loading of 16.1 mg/g glucan in the raw corn stover. The additives were applied individually at 150, 300, and 600 mg/g glucan in the pretreated solids and in combinations of equal amounts of each that totaled 600 mg/g. The greatest increase in total sugar release was by Tween-20 with SO(2) pretreated solids followed by PEG6000 with ARP solids and Tween-20 with lime solids. The effectiveness of the additives was observed to depend on the type of sugars left in the solids, suggesting that it may be more beneficial to use the mixture of these additives to realize a high total sugar yield. In addition, little enhancement in sugar release was possible beyond a loading of 150 mg additives/g glucan for most pretreatments, and combinations did not improve sugar release much over use of additives alone for all except SO(2). Additives were also found to significantly increase concentrations of cellobiose and cellooligomers after 72 h of Avicel hydrolysis.

  16. The effect of an additional phosphite stabilizer on the properties of radiation cross-linked vitamin E blends of UHMWPE.

    PubMed

    Oral, Ebru; Neils, Andrew; Yabannavar, Pooja; Muratoglu, Orhun K

    2014-06-01

    Antioxidant stabilization of radiation cross-linked ultrahigh molecular weight polyethylene (UHMWPE) has been introduced to improve the oxidative stability of total joint implant bearing surfaces. Blending of an antioxidant with UHMWPE resin powder followed by consolidation and radiation cross-linking has been cleared by the FDA for use in both total hips and total knees for designs incorporating two antioxidants, namely vitamin E and Covernox™ (a medical grade version of Irganox™ 1010). The antioxidants in the polymer are expected to protect the polymer during consolidation, during radiation cross-linking, on the shelf before implantation, and in vivo after implantation. To maximize the protection of the polymer afforded by the antioxidant in vivo, a novel approach may be the use of multiple antioxidants, especially to protect the primary antioxidant for a longer period of time. We hypothesized that the addition of a phosphite stabilizer (Irgafos 168™) commonly used in conjunction with hindered phenolic antioxidants in polymer processing could improve the oxidative stability of radiation cross-linked blends of vitamin E. To test our hypothesis, we prepared UHMWPE blends with 0.05 wt% Irgafos and 0.05 wt% vitamin E and compared its cross-link density, wear resistance, tensile properties, and impact strength to control blends containing only vitamin E. Our hypothesis was not supported; the cross-link density of UHMWPE was significantly decreased by the additive without additional benefit to oxidative stability. To our knowledge, this was the first attempt at using multiple stabilizers in medical grade UHMWPE.

  17. Microplastic moves pollutants and additives to worms, reducing functions linked to health and biodiversity.

    PubMed

    Browne, Mark Anthony; Niven, Stewart J; Galloway, Tamara S; Rowland, Steve J; Thompson, Richard C

    2013-12-01

    Inadequate products, waste management, and policy are struggling to prevent plastic waste from infiltrating ecosystems [1, 2]. Disintegration into smaller pieces means that the abundance of micrometer-sized plastic (microplastic) in habitats has increased [3] and outnumbers larger debris [2, 4]. When ingested by animals, plastic provides a feasible pathway to transfer attached pollutants and additive chemicals into their tissues [5-15]. Despite positive correlations between concentrations of ingested plastic and pollutants in tissues of animals, few, if any, controlled experiments have examined whether ingested plastic transfers pollutants and additives to animals. We exposed lugworms (Arenicola marina) to sand with 5% microplastic that was presorbed with pollutants (nonylphenol and phenanthrene) and additive chemicals (Triclosan and PBDE-47). Microplastic transferred pollutants and additive chemicals into gut tissues of lugworms, causing some biological effects, although clean sand transferred larger concentrations of pollutants into their tissues. Uptake of nonylphenol from PVC or sand reduced the ability of coelomocytes to remove pathogenic bacteria by >60%. Uptake of Triclosan from PVC diminished the ability of worms to engineer sediments and caused mortality, each by >55%, while PVC alone made worms >30% more susceptible to oxidative stress. As global microplastic contamination accelerates, our findings indicate that large concentrations of microplastic and additives can harm ecophysiological functions performed by organisms. PMID:24309271

  18. Microplastic moves pollutants and additives to worms, reducing functions linked to health and biodiversity.

    PubMed

    Browne, Mark Anthony; Niven, Stewart J; Galloway, Tamara S; Rowland, Steve J; Thompson, Richard C

    2013-12-01

    Inadequate products, waste management, and policy are struggling to prevent plastic waste from infiltrating ecosystems [1, 2]. Disintegration into smaller pieces means that the abundance of micrometer-sized plastic (microplastic) in habitats has increased [3] and outnumbers larger debris [2, 4]. When ingested by animals, plastic provides a feasible pathway to transfer attached pollutants and additive chemicals into their tissues [5-15]. Despite positive correlations between concentrations of ingested plastic and pollutants in tissues of animals, few, if any, controlled experiments have examined whether ingested plastic transfers pollutants and additives to animals. We exposed lugworms (Arenicola marina) to sand with 5% microplastic that was presorbed with pollutants (nonylphenol and phenanthrene) and additive chemicals (Triclosan and PBDE-47). Microplastic transferred pollutants and additive chemicals into gut tissues of lugworms, causing some biological effects, although clean sand transferred larger concentrations of pollutants into their tissues. Uptake of nonylphenol from PVC or sand reduced the ability of coelomocytes to remove pathogenic bacteria by >60%. Uptake of Triclosan from PVC diminished the ability of worms to engineer sediments and caused mortality, each by >55%, while PVC alone made worms >30% more susceptible to oxidative stress. As global microplastic contamination accelerates, our findings indicate that large concentrations of microplastic and additives can harm ecophysiological functions performed by organisms.

  19. Vegetation feedbacks of nutrient addition lead to a weaker carbon sink in an ombrotrophic bog.

    PubMed

    Larmola, Tuula; Bubier, Jill L; Kobyljanec, Christine; Basiliko, Nathan; Juutinen, Sari; Humphreys, Elyn; Preston, Michael; Moore, Tim R

    2013-12-01

    To study vegetation feedbacks of nutrient addition on carbon sequestration capacity, we investigated vegetation and ecosystem CO2 exchange at Mer Bleue Bog, Canada in plots that had been fertilized with nitrogen (N) or with N plus phosphorus (P) and potassium (K) for 7-12 years. Gross photosynthesis, ecosystem respiration, and net CO2 exchange were measured weekly during May-September 2011 using climate-controlled chambers. A substrate-induced respiration technique was used to determine the functional ability of the microbial community. The highest N and NPK additions were associated with 40% less net CO2 uptake than the control. In the NPK additions, a diminished C sink potential was due to a 20-30% increase in ecosystem respiration, while gross photosynthesis rates did not change as greater vascular plant biomass compensated for the decrease in Sphagnum mosses. In the highest N-only treatment, small reductions in gross photosynthesis and no change in ecosystem respiration led to the reduced C sink. Substrate-induced microbial respiration was significantly higher in all levels of NPK additions compared with control. The temperature sensitivity of respiration in the plots was lower with increasing cumulative N load, suggesting more labile sources of respired CO2 . The weaker C sink potential could be explained by changes in nutrient availability, higher woody : foliar ratio, moss loss, and enhanced decomposition. Stronger responses to NPK fertilization than to N-only fertilization for both shrub biomass production and decomposition suggest that the bog ecosystem is N-P/K colimited rather than N-limited. Negative effects of further N-only deposition were indicated by delayed spring CO2 uptake. In contrast to forests, increased wood formation and surface litter accumulation in bogs seem to reduce the C sink potential owing to the loss of peat-forming Sphagnum.

  20. Pyrolysis of simple coal model compounds containing aromatic carboxylic acids: Does decarboxylation lead to cross-linking?

    SciTech Connect

    Eskay, T.P.; Britt, P.F.; Buchanan, A.C. III

    1996-02-01

    The thermolysis of two aromatic carboxylic acids 1,2-(3,3`-dicarboxyphenyl)ethane (2) have been investigated at 400{degree} C as models of carboxylic acids in low rank coals. The major decomposition pathway observed is decarboxylation, which mainly occurs by an ionic pathway. This decarboxylation route does not lead to any significant amount of coupling or high molecular weight products that would be indicative of cross-linking products in coal. The pyrolysis of 1 and 2 will be investigated under a variety of conditions that better mimic the enviromment found in coal to further delineate the role that decarboxylation plays in coal cross-linking chemistry.

  1. Recent new additives for electric vehicle lead-acid batteries for extending the cycle life and capacity

    SciTech Connect

    Kozawa, A.; Sato, A.; Fujita, K.; Brodd, D.

    1997-12-01

    An electrochemically prepared colloidal graphite was found to be an excellent additive for lead-acid batteries. The new additive extends the capacity and cycle life of new and old batteries and can regenerate old, almost dead, batteries. The colloidal graphite is stable in aqueous solution and the extremely fine particles are adsorbed mainly on the positive electrode. This additive has been given the name, {alpha}-Pholon. The amount required is very small: only 6% to 10% of volume of the {alpha}-Pholon solution (about 2% colloidal graphite in water solution). The beneficial effect of the new additive was demonstrated with motorcycle batteries and forklift batteries.

  2. Cinchona Alkaloid Catalyzed Sulfa-Michael Addition Reactions Leading to Enantiopure β-Functionalized Cysteines.

    PubMed

    Breman, Arjen C; Telderman, Suze E M; van Santen, Roy P M; Scott, Jamie I; van Maarseveen, Jan H; Ingemann, Steen; Hiemstra, Henk

    2015-11-01

    Sulfa-Michael additions to α,β-unsaturated N-acylated oxazolidin-2-ones and related α,β-unsaturated α-amino acid derivatives have been enantioselectively catalyzed by Cinchona alkaloids functionalized with a hydrogen bond donating group at the C6' position. The series of Cinchona alkaloids includes known C6' (thio)urea and sulfonamide derivatives and several novel species with a benzimidazole, squaramide or a benzamide group at the C6' position. The sulfonamides were especially suited as bifunctional organocatalysts as they gave the products in very good diastereoselectivity and high enantioselectivity. In particular, the C6' sulfonamides catalyzed the reaction with the α,β-unsaturated α-amino acid derivatives to afford the products in a diastereomeric ratio as good as 93:7, with the major isomer being formed in an ee of up to 99%. The products of the organocatalytic sulfa-Michael addition to α,β-unsaturated α-amino acid derivatives were subsequently converted in high yields to enantiopure β-functionalized cysteines suitable for native chemical ligation.

  3. Structural analysis of the varicella-zoster virus gp98-gp62 complex: posttranslational addition of N-linked and O-linked oligosaccharide moieties.

    PubMed

    Montalvo, E A; Parmley, R T; Grose, C

    1985-03-01

    Varicella-zoster virus specifies the formation of several glycoproteins, including the preponderant gp98-gp62 glycoprotein complex in the outer membranes of virus-infected cells. These viral glycoproteins are recognized and precipitated by a previously described monoclonal antibody designated monoclone 3B3. When an immunoblot analysis was performed, only gp98 was reactive with monoclone 3B3 antibody; likewise, titration in the presence of increased concentrations of sodium dodecyl sulfate during antigen-antibody incubations caused selective precipitation of gp98 but not gp62. Further structural analyses of gp98 were performed by using the glycosidases endo-beta-N-acetylglucosaminidase H (endoglycosidase H) and neuraminidase and two inhibitors of glycosylation (tunicamycin and monensin). In addition to gp98, antibody 3B3 reacted with several intermediate products, including gp90, gp88, gp81, and a nonglycosylated polypeptide, p73. Since gp98 was completely resistant to digestion with endoglycosidase H, it contained only complex carbohydrate moieties; conversely, gp81 contained mainly high-mannose residues. Polypeptide p73 was immunodetected in the presence of tunicamycin and designated as a nascent recipient of N-linked sugars, whereas gp88 was considered to contain O-linked oligosaccharides because its synthesis was not affected by tunicamycin. The ionophore monensin inhibited production of mature gp98, but other intermediate forms, including gp90, were detected. Since the latter product was similar in molecular weight to the desialated form of gp98, one effect of monensin treatment of varicella-zoster virus-infected cells was to block the addition of N-acetylneuraminic acid. Monensin also blocked insertion of gp98 into the plasma membrane and, as determined by electron microscopy, inhibited envelopment of the nucleocapsid and its transport within the cytoplasm. On the basis of this study, we reached the following conclusions: the primary antibody 3B3-binding

  4. Study of cadmium, zinc and lead biosorption by orange wastes using the subsequent addition method.

    PubMed

    Pérez-Marín, A B; Ballester, A; González, F; Blázquez, M L; Muñoz, J A; Sáez, J; Zapata, V Meseguer

    2008-11-01

    The biosorption of several metals (Cd2+, Zn2+ and Pb2+) by orange wastes has been investigated in binary systems. Multicomponent sorption isotherms were obtained using an original procedure, similar to that proposed by Pagnanelli et al. [Pagnanelli, F., Petrangeli, M.P., Toro, L., Trifoni, M., Veglio, F., 2001a. Biosorption of metal ions on Arthrobacter sp.: biomass characterization and biosorption modelling. Environ. Sci. Technol. 34, 2773-2778] for monoelement systems, known as subsequent addition method (SAM). Experimental sorption data were analysed using an extended multicomponent Langmuir equation. The maximum sorption uptake was approximately 0.25mmol/g for the three binary systems studied. The reliability of the proposed procedure for obtaining the equilibrium data in binary systems was verified by means of a statistical F-test. PMID:18440805

  5. Biological responses of a simulated marine food chain to lead addition.

    PubMed

    Soto-Jiménez, Martín F; Arellano-Fiore, Claudia; Rocha-Velarde, Ruth; Jara-Marini, Martín E; Ruelas-Inzunza, Jorge; Voltolina, Domenico; Frías-Espericueta, Martín G; Quintero-Alvarez, Jesús M; Páez-Osuna, Federico

    2011-07-01

    This investigation sought to assess the biological responses to Pb along a simplified four-level food chain, from the primary producer, the microalgae Tetraselmis suecica, grown in a control medium with < 1 µg/L of Pb and exposed to a sublethal dose (20 µg/L of Pb) and used as the base of a simulated food chain, through the primary-, secondary-, and tertiary-level consumers, namely, the brine shrimp, Artemia franciscana; the white-leg shrimp, Litopenaeus vannamei; and the grunt fish, Haemulon scudderi, respectively. Growth of Pb-exposed T. suecica was 40% lower than that of the control cultures, and survival of A. franciscana fed this diet was 25 to 30% lower than the control. No differences in the growth rates of Pb-exposed and control shrimp and fish and no gross morphological changes were evident in the exposed specimens. However, the exposed shrimp and fish had 20 and 15% higher mortalities than their controls, respectively. In addition, behavioral alterations were observed in exposed shrimp and fish, including reduction in food consumption or cessation of feeding, breathing air out of the water, reduction of motility, and erratic swimming. The negative correlation between Pb concentration in whole body of shrimp and fish and Fulton's condition factor suggested also that the exposed organisms were stressed because of Pb accumulation.

  6. Developmental neurotoxicity of monocrotophos and lead is linked to thyroid disruption

    PubMed Central

    Kumar, B. Kala; Reddy, A. Gopala; Krishna, A. Vamsi; Quadri, S. S. Y. H.; Kumar, P. Shiva

    2016-01-01

    Aim: A role of thyroid disruption in developmental neurotoxicity of monocrotophos (MCP) and lead is studied. Materials and Methods: A total of 24 female rats after conception were randomized into four groups of six each and treated as follows: Group I - Sham was administered distilled water orally. Group II - A positive control was administered methyl methimazole at 0.02% orally in drinking water. Group III - MCP orally at 0.3 mg/kg and Group IV - Lead acetate at 0.2% orally in drinking water. The drug was administered from gestation day 3 through post-natal day 21 in all the groups. Acetylcholinesterase (AChE) inhibition, thyroid profile (thyroid stimulating hormone, T3 and T4), neurodevelopment (brain wet weights, DNA, RNA and protein), and neurobehavioral (elevated plus maze, photoactometry, and Morris water maze) parameters were assessed in pups. A histopathology of thyroid of dams and brain of progeny was conducted. Results: Inhibition of AChE was <20%. Thyroid profile decreased in the treatment groups. Neurodevelopmental and neurobehavioral parameters did not reveal any significant changes. Thyroid architecture was affected significantly with MCP and lead. Cortical layers too were affected. The three layers of cerebellum either had abnormal arrangement or decreased cellularity in all treated groups relating to thyroid disruption. Conclusion: MCP and lead might have affected the development of cerebrum and cerebellum via thyroid disruption leading to developmental neurotoxicity. PMID:27051198

  7. Effect of a mineral additive on the electrical performances of the positive plate of lead acid battery

    NASA Astrophysics Data System (ADS)

    Foudia, M.; Matrakova, M.; Zerroual, L.

    2015-04-01

    The objective of this work is to improve the performance of the positive electrode of lead-acid battery. The use of the additive in the positive paste is to increase the capacity and cycle life of the positive active material. Mineral porous additives, dispersed uniformly in the PAM, may act as acid reservoirs and favor the ionic diffusion. The results show that the addition of mineral additive in the paste before oxidation influences the composition and the crystal size of the PAM after oxidation. We observe a remarkable improvement of the discharge capacity of the PAM for an amount of additive ranging between 1 and 5%. Nano-sized particles of PbO2 with amorphous character are obtained. XRD, TG and DSC, SEM, and galvanostatic discharge were used as techniques of investigation.

  8. Stannous sulfate as an electrolyte additive for lead acid battery made from a novel ultrafine leady oxide

    NASA Astrophysics Data System (ADS)

    Wang, Qin; Liu, Jianwen; Yang, Danni; Yuan, Xiqing; Li, Lei; Zhu, Xinfeng; Zhang, Wei; Hu, Yucheng; Sun, Xiaojuan; Liang, Sha; Hu, Jingping; Kumar, R. Vasant; Yang, Jiakuan

    2015-07-01

    The effects of SnSO4 as an electrolyte additive on the microstructure of positive plate and electrochemical performance of lead acid battery made from a novel leady oxide are investigated. The novel leady oxide is synthesized through leaching of spent lead paste in citric acid solution. The novel leady oxides are used to prepare working electrode (WE) subjected to electrochemical cyclic voltammetry (CV) tests. Moreover, the novel leady oxides are used as active materials of positive plate assembled as a testing battery of 1.85 A h capacity. In CV tests, SEM/EDX results show that the major crystalline phase of the paste in WE after CV cycles is PbSO4. The larger column-shaped PbSO4 crystals easily generate in the paste of WE without an electrolyte additive of SnSO4. However, PbSO4 crystals significantly become smaller with the addition of SnSO4 in the electrolyte. In batteries testing, SEM results show that an electrolyte additive of SnSO4 could effectively decrease PbO2 particle size in the positive active materials of the teardown battery at the end of charging procedure. It is indicated that an electrolyte additive of SnSO4 could have a positive influence on restraining larger particles of irreversible sulfation in charge/discharge cycles of battery testing.

  9. Studying the effect of nano lead compounds additives on the concrete shielding properties for γ-rays

    NASA Astrophysics Data System (ADS)

    Hassan, H. E.; Badran, H. M.; Aydarous, A.; Sharshar, T.

    2015-10-01

    In the present work the effect of concrete incorporation with two types of nano-lead compounds on its γ-ray shielding characteristics is investigated. The concrete samples were prepared according to the local standards of building materials and doped by different percentages of PbO and PbTiO3 nano powders which were prepared using co-precipitation and oxalate precursor techniques, respectively. In addition, commercial PbO2 powder additive was used to check the effect of particle size on concrete attenuation properties. The phase composition and particle size of all the lead-oxide additives were confirmed by XRD and TEM imaging. The γ-rays attenuation coefficients were measured as a function of the additive percentage of lead compounds for γ-ray energies of 662, 1173 and 1332 keV using 137Cs and 60Co sources. The microstructure changes occurred in the concrete samples doped with Pb compounds additives were probed using the positron annihilation spectroscopy (PAS) and the results were compared with that for normal concrete. The obtained data revealed that the overall defect density of the investigated samples, as seen by the positrons, decreases with increasing the nano-PbO contents which is in agreement with the determined values of the samples apparent densities. It was found that the γ-ray attenuation coefficient of concrete doped by nano-PbO is improved. The results are explained in the view of the fine structure enhanced modification and its impact on the γ-ray interaction probability at different energies.

  10. Combined exposure to lead, inorganic mercury and methylmercury shows deviation from additivity for cardiovascular toxicity in rats.

    PubMed

    Wildemann, Tanja M; Weber, Lynn P; Siciliano, Steven D

    2015-08-01

    Environmental exposure to metal mixtures in the human population is common. Mixture risk assessments are often challenging because of a lack of suitable data on the relevant mixture. A growing number of studies show an association between lead or mercury exposure and cardiovascular effects. We investigated the cardiovascular effects of single metal exposure or co-exposure to methylmercury [MeHg(I)], inorganic mercury [Hg(II)] and lead [Pb(II)]. Male Wistar rats received four different metal mixtures for 28 days through the drinking water. The ratios of the metals were based on reference and environmental exposure values. Blood and pulse pressure, cardiac output and electrical activity of the heart were selected as end-points. While exposure to only MeHg(I) increased the systolic blood pressure and decreased cardiac output, the effects were reversed with combined exposures (antagonism). In contrast to these effects, combined exposures negatively affected the electrical activity of the heart (synergism). Thus, it appears that estimates of blood total Hg levels need to be paired with estimates of what species of mercury dominate exposure as well as whether lead co-exposure is present to link total blood Hg levels to cardiovascular effects. Based on current human exposure data and our results, there may be an increased risk of cardiac events as a result of combined exposures to Hg(II), MeHg(I) and Pb(II). This increased risk needs to be clarified by analyzing lead and Hg exposure data in relation to cardiac electrical activity in epidemiological studies.

  11. Dysfunction of spatacsin leads to axonal pathology in SPG11-linked hereditary spastic paraplegia

    PubMed Central

    Pérez-Brangulí, Francesc; Mishra, Himanshu K.; Prots, Iryna; Havlicek, Steven; Kohl, Zacharias; Saul, Domenica; Rummel, Christine; Dorca-Arevalo, Jonatan; Regensburger, Martin; Graef, Daniela; Sock, Elisabeth; Blasi, Juan; Groemer, Teja W.; Schlötzer-Schrehardt, Ursula; Winkler, Jürgen; Winner, Beate

    2014-01-01

    Hereditary spastic paraplegias are a group of inherited motor neuron diseases characterized by progressive paraparesis and spasticity. Mutations in the spastic paraplegia gene SPG11, encoding spatacsin, cause an autosomal-recessive disease trait; however, the precise knowledge about the role of spatacsin in neurons is very limited. We for the first time analyzed the expression and function of spatacsin in human forebrain neurons derived from human pluripotent stem cells including lines from two SPG11 patients and two controls. SPG11 patients'-derived neurons exhibited downregulation of specific axonal-related genes, decreased neurite complexity and accumulation of membranous bodies within axonal processes. Altogether, these data point towards axonal pathologies in human neurons with SPG11 mutations. To further corroborate spatacsin function, we investigated human pluripotent stem cell-derived neurons and mouse cortical neurons. In these cells, spatacsin was located in axons and dendrites. It colocalized with cytoskeletal and synaptic vesicle (SV) markers and was present in synaptosomes. Knockdown of spatacsin in mouse cortical neurons evidenced that the loss of function of spatacsin leads to axonal instability by downregulation of acetylated tubulin. Finally, time-lapse assays performed in SPG11 patients'-derived neurons and spatacsin-silenced mouse neurons highlighted a reduction in the anterograde vesicle trafficking indicative of impaired axonal transport. By employing SPG11 patient-derived forebrain neurons and mouse cortical neurons, this study provides the first evidence that SPG11 is implicated in axonal maintenance and cargo trafficking. Understanding the cellular functions of spatacsin will allow deciphering mechanisms of motor cortex dysfunction in autosomal-recessive hereditary spastic paraplegia. PMID:24794856

  12. Blood lead concentrations in Alaskan tundra swans: linking breeding and wintering areas with satellite telemetry

    USGS Publications Warehouse

    Ely, Craig R.; Franson, Christian

    2014-01-01

    Tundra swans (Cygnus columbianus) like many waterfowl species are susceptible to lead (Pb) poisoning, and Pb-induced mortality has been reported from many areas of their wintering range. Little is known however about Pb levels throughout the annual cycle of tundra swans, especially during summer when birds are on remote northern breeding areas where they are less likely to be exposed to anthropogenic sources of Pb. Our objective was to document summer Pb levels in tundra swans throughout their breeding range in Alaska to determine if there were population-specific differences in blood Pb concentrations that might pose a threat to swans and to humans that may consume them. We measured blood Pb concentrations in tundra swans at five locations in Alaska, representing birds that winter in both the Pacific Flyway and Atlantic Flyway. We also marked swans at each location with satellite transmitters and coded neck bands, to identify staging and wintering sites and determine if winter site use correlated with summer Pb concentrations. Blood Pb levels were generally low (<0.2 μg/ml) in swans across all breeding areas. Pb levels were lower in cygnets than adults, suggesting that swans were likely exposed to Pb on wintering areas or on return migration to Alaska, rather than on the summer breeding grounds. Blood Pb levels varied significantly across the five breeding areas, with highest concentrations in birds on the North Slope of Alaska (wintering in the Atlantic Flyway), and lowest in birds from the lower Alaska Peninsula that rarely migrate south for winter.

  13. Blood lead concentrations in Alaskan tundra swans: linking breeding and wintering areas with satellite telemetry.

    PubMed

    Ely, Craig R; Franson, J Christian

    2014-04-01

    Tundra swans (Cygnus columbianus) like many waterfowl species are susceptible to lead (Pb) poisoning, and Pb-induced mortality has been reported from many areas of their wintering range. Little is known however about Pb levels throughout the annual cycle of tundra swans, especially during summer when birds are on remote northern breeding areas where they are less likely to be exposed to anthropogenic sources of Pb. Our objective was to document summer Pb levels in tundra swans throughout their breeding range in Alaska to determine if there were population-specific differences in blood Pb concentrations that might pose a threat to swans and to humans that may consume them. We measured blood Pb concentrations in tundra swans at five locations in Alaska, representing birds that winter in both the Pacific Flyway and Atlantic Flyway. We also marked swans at each location with satellite transmitters and coded neck bands, to identify staging and wintering sites and determine if winter site use correlated with summer Pb concentrations. Blood Pb levels were generally low (<0.2 μg/ml) in swans across all breeding areas. Pb levels were lower in cygnets than adults, suggesting that swans were likely exposed to Pb on wintering areas or on return migration to Alaska, rather than on the summer breeding grounds. Blood Pb levels varied significantly across the five breeding areas, with highest concentrations in birds on the North Slope of Alaska (wintering in the Atlantic Flyway), and lowest in birds from the lower Alaska Peninsula that rarely migrate south for winter.

  14. An in situ generated carbon as integrated conductive additive for hierarchical negative plate of lead-acid battery

    NASA Astrophysics Data System (ADS)

    Saravanan, M.; Ganesan, M.; Ambalavanan, S.

    2014-04-01

    In this work, we report an in situ generated carbon from sugar as additive in the Negative Active Mass (NAM) which enhances the charge-discharge characteristics of the lead-acid cells. In situ formed sugar derived carbon (SDC) with leady oxide (LO) provides a conductive network and excellent protection against NAM irreversible lead sulfation. The effect of SDC and carbon black (CB) added negative plates are characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), galvanostatic charge-discharge, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. The results show that subtle changes in the addition of carbon to NAM led to subsequent changes on the performance during partial-state-of-charge (PSoC) operations in lead-acid cells. Furthermore, SDC added cells exhibit remarkable improvement in the rate capability, active material utilization, cycle performance and charge acceptance compared to that of the conventional CB added cells. The impact of SDC with LO at various synthesis conditions on the electrochemical performance of the negative plate is studied systematically.

  15. Neonatal anoxia leads to time dependent progression of mitochondrial linked apoptosis in rat cortex and associated long term sensorimotor deficits.

    PubMed

    Samaiya, Puneet K; Narayan, Gopeshwar; Kumar, Ashok; Krishnamurthy, Sairam

    2016-08-01

    Neonatal anoxia arises due to oxygen deprivation at the time of birth and results in life long neurodevelopmental deficits and sometimes may lead to death. The present study investigated the time dependent cortical mitochondrial dysfunction linked apoptosis and related sensorimotor deficits in neonates. Neonates after 30h to birth (P2) were subjected to anoxia of two episodes (10min in each) at a time interval of 24h by passing 100% N2 into an enclosed chamber as confirmed by pulse oximetry. Sensorimotor activities like reflex latency and hanging latency were carried out 24h after last anoxic episode i.e. from P4 (day-1) and continued up to P10 (day-7). Mitochondrial dysfunction after anoxia was evident by the decrease in respiration states, respiratory control ratio (RCR), antioxidant enzyme activity but an increase in oxidative stress and lipid peroxidation and alteration in mitochondrial membrane potential (MMP) at different time points (30min, 24h and day-7). A change in expression of Bcl-2 family proteins and opening of mitochondrial transition pore (mPTP) in terms of mitochondrial swelling was observed resulting in release of cytochrome-C which further activated intrinsic (mitochondrial) pathway of apoptosis through increased expression of caspase-9/3 as confirmed by flow cytometry. In conclusion, anoxia injury leads to progressive activation of mitochondrial events leading to increase in apoptotic cell death following secondary pathological insult. Therefore, strategies in limiting mitochondrial-linked apoptosis during the secondary insult input process may be useful in treatment of long term sensorimotor deficits following anoxia. PMID:27184438

  16. Lead acid battery performance and cycle life increased through addition of discrete carbon nanotubes to both electrodes

    NASA Astrophysics Data System (ADS)

    Sugumaran, Nanjan; Everill, Paul; Swogger, Steven W.; Dubey, D. P.

    2015-04-01

    Contemporary applications are changing the failure mechanisms of lead acid batteries. Sulfation at the negative electrode, acid stratification, and dendrite formation now precede positive electrode failures such as grid corrosion and active material shedding. To attenuate these failures, carbon has been explored as a negative electrode additive to increase charge acceptance, eliminate sulfation, and extend cycle life. Frequently, however, carbon incorporation decreases paste density and hinders manufacturability. Discrete carbon nanotubes (dCNT), also known as Molecular Rebar®, are lead acid battery additives which can be stably incorporated into either electrode to increase charge acceptance and cycle life with no change to paste density and without impeding the manufacturing process. Here, full-scale automotive batteries containing dCNT in the negative electrode or both negative and positive electrodes are compared to control batteries. dCNT batteries show little change to Reserve Capacity, improved Cold Cranking, increased charge acceptance, and enhanced overall system efficiency. Life cycle tests show >60% increases when dCNT are incorporated into the negative electrode (HRPSoC/SBA) and up to 500% when incorporated into both electrodes (SBA), with water loss per cycle reduced >20%. Failure modes of cycled batteries are discussed and a hypothesis of dCNT action is introduced: the dCNT/Had Overcharge Reaction Mechanism.

  17. Sample data processing in an additive and reproducible taxonomic workflow by using character data persistently linked to preserved individual specimens

    PubMed Central

    Kilian, Norbert; Henning, Tilo; Plitzner, Patrick; Müller, Andreas; Güntsch, Anton; Stöver, Ben C.; Müller, Kai F.; Berendsohn, Walter G.; Borsch, Thomas

    2015-01-01

    We present the model and implementation of a workflow that blazes a trail in systematic biology for the re-usability of character data (data on any kind of characters of pheno- and genotypes of organisms) and their additivity from specimen to taxon level. We take into account that any taxon characterization is based on a limited set of sampled individuals and characters, and that consequently any new individual and any new character may affect the recognition of biological entities and/or the subsequent delimitation and characterization of a taxon. Taxon concepts thus frequently change during the knowledge generation process in systematic biology. Structured character data are therefore not only needed for the knowledge generation process but also for easily adapting characterizations of taxa. We aim to facilitate the construction and reproducibility of taxon characterizations from structured character data of changing sample sets by establishing a stable and unambiguous association between each sampled individual and the data processed from it. Our workflow implementation uses the European Distributed Institute of Taxonomy Platform, a comprehensive taxonomic data management and publication environment to: (i) establish a reproducible connection between sampled individuals and all samples derived from them; (ii) stably link sample-based character data with the metadata of the respective samples; (iii) record and store structured specimen-based character data in formats allowing data exchange; (iv) reversibly assign sample metadata and character datasets to taxa in an editable classification and display them and (v) organize data exchange via standard exchange formats and enable the link between the character datasets and samples in research collections, ensuring high visibility and instant re-usability of the data. The workflow implemented will contribute to organizing the interface between phylogenetic analysis and revisionary taxonomic or monographic work

  18. Effect of an iodine-containing additive on the composition, structure, and morphology of chemically deposited lead selenide films

    NASA Astrophysics Data System (ADS)

    Smirnova, Z. I.; Bakanov, V. M.; Maskaeva, L. N.; Markov, V. F.; Voronin, V. I.

    2014-12-01

    The effect of an ammonium iodide additive on the elemental and phase compositions, structural parameters, and surface morphology of lead selenide films synthesized by chemical deposition from aqueous solutions has been studied using X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray analysis. It has been established that the obtained PbSe films have a multiphase structure. The iodine content of the films is directly proportional to the NH4I concentration in the reaction mixture and increases linearly with an increase in this concentration to 0.25 mol/L. No individual iodine-containing phases have been detected in the film structure. However, the introduction of iodine leads to an increase in the PbSe phase lattice parameter from ˜6.11 to ˜6.16 Å and to a decrease in the crystal grain size to ˜ 20 nm. It has been found that there is a correlation between the grain size, lattice parameter, and ammonium iodide concentration in the reaction mixture, which can be explained by changes in the film growth mechanism at the initial growth steps.

  19. Ionic liquid-linked dual magnetic microextraction of lead(II) from environmental samples prior to its micro-sampling flame atomic absorption spectrometric determination.

    PubMed

    Yilmaz, Erkan; Soylak, Mustafa

    2013-11-15

    A novel and rapid microextraction approach termed as ionic liquid-linked dual magnetic microextraction (IL-DMME), was developed for the atomic absorption spectrometric determination of lead. The developed method based on a combination of dispersive liquid-liquid microextraction (DLLME) and dispersive micro solid-phase extraction (D-μ-SPE). In the first DLLME step, 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6], was selected to extract the lead-pyrrolidine-dithiocarbamate (Pb-PDC) complex from sample solution by the assistance of vortex agitator. After the first step, fifty milligrams of Fe3O4 magnetic nanoparticles (MNPs) were added to extraction of the ionic liquid and Pb-PDC complex in aqueous solution. The effective factors in proposed IL-DMME procedure, including volume of 1-butyl-3-methylimidazolium hexafluorophosphate, amount of Fe3O4 magnetic nanoparticles, vortex time, amount of ammonium pyrrolidinedithiocarbamate, sample volume and matrix effect were optimized in details. Under the optimal conditions, the method present has low detection limit (0.57 μg L(-1)), high preconcentration factor (160) and good repeatability (<7.5%, n=10). The accuracy of the developed method was evaluated by the analysis of the certified reference materials and addition-recovery tests. The method was successfully applied to the determination of lead in water, plant and hair samples.

  20. Ionic liquid-linked dual magnetic microextraction of lead(II) from environmental samples prior to its micro-sampling flame atomic absorption spectrometric determination.

    PubMed

    Yilmaz, Erkan; Soylak, Mustafa

    2013-11-15

    A novel and rapid microextraction approach termed as ionic liquid-linked dual magnetic microextraction (IL-DMME), was developed for the atomic absorption spectrometric determination of lead. The developed method based on a combination of dispersive liquid-liquid microextraction (DLLME) and dispersive micro solid-phase extraction (D-μ-SPE). In the first DLLME step, 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6], was selected to extract the lead-pyrrolidine-dithiocarbamate (Pb-PDC) complex from sample solution by the assistance of vortex agitator. After the first step, fifty milligrams of Fe3O4 magnetic nanoparticles (MNPs) were added to extraction of the ionic liquid and Pb-PDC complex in aqueous solution. The effective factors in proposed IL-DMME procedure, including volume of 1-butyl-3-methylimidazolium hexafluorophosphate, amount of Fe3O4 magnetic nanoparticles, vortex time, amount of ammonium pyrrolidinedithiocarbamate, sample volume and matrix effect were optimized in details. Under the optimal conditions, the method present has low detection limit (0.57 μg L(-1)), high preconcentration factor (160) and good repeatability (<7.5%, n=10). The accuracy of the developed method was evaluated by the analysis of the certified reference materials and addition-recovery tests. The method was successfully applied to the determination of lead in water, plant and hair samples. PMID:24148489

  1. Modeling the impact of paste additives and pellet geometry on paste utilization within lead acid batteries during low rate discharges

    NASA Astrophysics Data System (ADS)

    Vargonen, Muhammed M.

    2015-01-01

    When designing a lead acid battery, there are many factors to consider in order to obtain the best compromise of cost, performance, and ease of manufacturability. We use a modeling approach to study some of the key factors which affect the amount of active material which can be utilized during a low rate discharge. We investigate the effects of pellet size, pellet geometry, disconnected grid mesh borders, and inert paste additives. Furthermore, we look at how the internal path length resistance within a pellet is dependent on those features. Our findings correlate well with earlier works, and help to explain some of the previously observed phenomenon. It is observed that utilization is indeed affected by pellet size, but small grid mesh sizes on the order of ∼4 mm edge lengths are necessary in order to realize a significant benefit. Utilization is presented as a function of pellet size, aspect ratio of the pellets, and the loading level of the inert additives in the pellets up to ten percent by volume.

  2. Influence of compost addition on lead and arsenic bioavailability in reclaimed orchard soil assessed using Porcellio scaber bioaccumulation test.

    PubMed

    Udovic, M; McBride, M B

    2012-02-29

    Long-term application of lead arsenate in orchards has led to a significant accumulation of Pb and As in the topsoil. Reclamation of old orchards for agricultural purposes entails the exposure of humans to Pb and As, which can be reduced by adequate remediation actions. In this study, we assessed the remediation efficiency of compost addition, commonly used as a sustainable agricultural practice, in decreasing the human exposure Pb and As by direct ingestion. The remediation was evaluated based on Pb and As bioavailability, assessed by means of a selective non-exhaustive chemical extraction (modified Morgan extraction, MME), with a physiologically based extraction test (PBET) for the assessment of Pb and As bioavailability in ingested soils and with a novel in vivo bioaccumulation test with isopods (Porcellio scaber). All the tests showed that compost addition consistently reduced Pb, but increased As potential bioavailability. The bioaccumulation test with P. scaber was sensitive to changes in Pb and As bioavailability in test soils. However, the results indicate that the bioavailability of As could be under- or overestimated using solely chemical extraction tests. Indirect assessment of trace metal bioavailability with bioaccumulation in isopods can be used as complementary source of data to the existing in vitro chemical extraction test approach for the estimation of human exposure to trace elements in polluted and remediated soil. This is the first report on the use of As accumulation in P. scaber as a tool for the assessment of As bioavailability in contaminated orchard soil.

  3. Assessing the IQ-earnings link in environmental lead impacts on children: have hazard effects been overstated?

    PubMed

    Salkever, David S

    2014-05-01

    Studies in the 1990s by Schwartz and by Salkever provided the bases for measuring the earnings impacts of IQ decrements due to lead exposure for children, and many subsequent regulatory, policy guidance, and academic analyses adopted the estimates from these studies. Results by Salkever implied somewhat greater impacts of IQ decrements, but have been contested, in a series of more recent critical review articles, as overestimates of the negative impacts on children׳s future earnings caused by IQ decrements due to lead exposure. This paper examines the contentions of proponents of this overstatement hypothesis, the applicability of the evidence they offer, and the results from an additional important study from 1998 heretofore overlooked in the literature. Results of this examination indicate that the evidence for the overstatement hypothesis is seriously flawed. Studies cited to support this hypothesis (1) often report only evidence on wage impacts and thus ignore IQ impacts on hours of work and work participation rates, (2) give lesser weight to or completely exclude population groups that show relatively higher IQ impacts (e.g., women), and (3) give substantial weight to pre-1980 wage and earning data, thereby omitting the influence of recent upward trends in skill differentials in earnings and increasing returns to education. Because of these and other deficiencies, available evidence does not substantiate the overstatement hypothesis. In contrast, recent evidence overlooked by the proponents of this hypothesis suggests that the results reported by Salkever understate the actual strength of the negative IQ impacts from lead exposure.

  4. Assessing the IQ-earnings link in environmental lead impacts on children: have hazard effects been overstated?

    PubMed

    Salkever, David S

    2014-05-01

    Studies in the 1990s by Schwartz and by Salkever provided the bases for measuring the earnings impacts of IQ decrements due to lead exposure for children, and many subsequent regulatory, policy guidance, and academic analyses adopted the estimates from these studies. Results by Salkever implied somewhat greater impacts of IQ decrements, but have been contested, in a series of more recent critical review articles, as overestimates of the negative impacts on children׳s future earnings caused by IQ decrements due to lead exposure. This paper examines the contentions of proponents of this overstatement hypothesis, the applicability of the evidence they offer, and the results from an additional important study from 1998 heretofore overlooked in the literature. Results of this examination indicate that the evidence for the overstatement hypothesis is seriously flawed. Studies cited to support this hypothesis (1) often report only evidence on wage impacts and thus ignore IQ impacts on hours of work and work participation rates, (2) give lesser weight to or completely exclude population groups that show relatively higher IQ impacts (e.g., women), and (3) give substantial weight to pre-1980 wage and earning data, thereby omitting the influence of recent upward trends in skill differentials in earnings and increasing returns to education. Because of these and other deficiencies, available evidence does not substantiate the overstatement hypothesis. In contrast, recent evidence overlooked by the proponents of this hypothesis suggests that the results reported by Salkever understate the actual strength of the negative IQ impacts from lead exposure. PMID:24814698

  5. The potential of oceanic transport and onshore leaching of additive-derived lead by marine macro-plastic debris.

    PubMed

    Nakashima, Etsuko; Isobe, Atsuhiko; Kako, Shin'ichiro; Itai, Takaaki; Takahashi, Shin; Guo, Xinyu

    2016-06-15

    The long-distance transport potential of toxic lead (Pb) by plastic marine debris was examined by pure water leaching experiments using plastic fishery floats containing high level of additive-Pb such as 5100±74.3mgkg(-1). The leaching of Pb ended after sequential 480-h leaching experiments, and the total leaching amount is equivalent to approximately 0.1% of total Pb in a float. But it recovered when the float was scratched using sandpaper. We propose that a "low-Pb layer," in which Pb concentration is negligibly small, be generated on the float surface by the initial leaching process. Thickness of the layer is estimated at 2.5±1.2μm, much shallower than flaws on floats scratched by sandpaper and floats littering beaches. The result suggests that the low-Pb layer is broken by physical abrasion when floats are washed ashore, and that Pb inside the floats can thereafter leach into beaches.

  6. The potential of oceanic transport and onshore leaching of additive-derived lead by marine macro-plastic debris.

    PubMed

    Nakashima, Etsuko; Isobe, Atsuhiko; Kako, Shin'ichiro; Itai, Takaaki; Takahashi, Shin; Guo, Xinyu

    2016-06-15

    The long-distance transport potential of toxic lead (Pb) by plastic marine debris was examined by pure water leaching experiments using plastic fishery floats containing high level of additive-Pb such as 5100±74.3mgkg(-1). The leaching of Pb ended after sequential 480-h leaching experiments, and the total leaching amount is equivalent to approximately 0.1% of total Pb in a float. But it recovered when the float was scratched using sandpaper. We propose that a "low-Pb layer," in which Pb concentration is negligibly small, be generated on the float surface by the initial leaching process. Thickness of the layer is estimated at 2.5±1.2μm, much shallower than flaws on floats scratched by sandpaper and floats littering beaches. The result suggests that the low-Pb layer is broken by physical abrasion when floats are washed ashore, and that Pb inside the floats can thereafter leach into beaches. PMID:27095373

  7. Influence of compost addition on lead and arsenic bioavailability in reclaimed orchard soil assessed using Porcellio scaber bioaccumulation test

    PubMed Central

    Udovic, M.; McBride, M.B.

    2015-01-01

    A long history of lead arsenate application in orchards has led to significant accumulation of Pb and As in the topsoil. Besides the threat that such soils represent for the environment, reclamation of old orchards for agricultural purposes implies the exposure of humans to Pb and As. In this study we assessed the influence of vegetable compost addition (as a sustainable agricultural practice) to contaminated acidic orchard soil on Pb and As bioavailability, assessed with two selective non-exhaustive chemical extractions and with an in vivo bioaccumulation test with an isopod (P. scaber). The treatment with compost caused a significant increase in soil pH and total carbon content, resulting in a consistent decrease of Pb bioavailability. In contrast, the bioavailability of As increased, indicating that a complementary treatment should be used for reducing the bioavailability of As in old orchard soils. This is the first report on the use of As accumulation in P. scaber as a tool for the assessment of As bioavailability in contaminated orchard soil. PMID:22240057

  8. Enhancement on wettability and intermetallic compound formation with an addition of Al on Sn-0.7Cu lead-free solder fabricated via powder metallurgy method

    NASA Astrophysics Data System (ADS)

    Adli, Nisrin; Razak, Nurul Razliana Abdul; Saud, Norainiza

    2016-07-01

    Due to the toxicity of lead (Pb), the exploration of another possibility for lead-free solder is necessary. Nowadays, SnCu alloys are being established as one of the lead-free solder alternatives. In this study, Sn-0.7Cu lead-free solder with an addition of 1wt% and 5wt% Al were investigated by using powder metallurgy method. The effect of Al addition on the wettability and intermetallic compound thickness (IMC) of Sn-0.7Cu-Al lead-free solder were appraised. Results showed that Al having a high potential to enhance Sn-0.7Cu lead-free solder due to its good wetting and reduction of IMC thickness. The contact angle and IMC of the Sn-0.7Cu-Al lead-free solder were decreased by 14.32% and 40% as the Al content increased from 1 wt% to 5 wt%.

  9. Separation of Lead from Crude Antimony by Pyro-Refining Process with NaPO3 Addition

    NASA Astrophysics Data System (ADS)

    Ye, Longgang; Hu, Yuejie; Xia, Zhimei; Chen, Yongming

    2016-06-01

    The main purpose of this study was to separate lead from crude antimony through an oxidation pyro-refining process and by using sodium metaphosphate as a lead elimination reagent. The process parameters that will affect the refining results were optimized experimentally under controlled conditions, such as the sodium metaphosphate charging dosage, the refining temperature and duration, and the air flow rate, to determine their effect on the lead content in refined antimony and the lead removal rate. A minimum lead content of 0.0522 wt.% and a 98.6% lead removal rate were obtained under the following optimal conditions: W_{{{NaPO}_{{3}} }} = 15% W Sb (where W represents weight), a refining temperature of 800°C, a refining time of 30 min, and an air flow rate of 3 L/min. X-ray diffractometry and scanning electron microscopy showed that high-purity antimony was obtained. The smelting operation is free from smoke or ammonia pollution when using monobasic sodium phosphate or ammonium dihydrogen phosphate as the lead elimination reagent. However, this refining process can also remove a certain amount of sulfur, cobalt, and silicon simultaneously, and smelting results also suggest that sodium metaphosphate can be used as a potential lead elimination reagent for bismuth and copper refining.

  10. Employing Lead Thiocyanate Additive to Reduce the Hysteresis and Boost the Fill Factor of Planar Perovskite Solar Cells.

    PubMed

    Ke, Weijun; Xiao, Chuanxiao; Wang, Changlei; Saparov, Bayrammurad; Duan, Hsin-Sheng; Zhao, Dewei; Xiao, Zewen; Schulz, Philip; Harvey, Steven P; Liao, Weiqiang; Meng, Weiwei; Yu, Yue; Cimaroli, Alexander J; Jiang, Chun-Sheng; Zhu, Kai; Al-Jassim, Mowafak; Fang, Guojia; Mitzi, David B; Yan, Yanfa

    2016-07-01

    Lead thiocyanate in the perovskite precursor can increase the grain size of a perovskite thin film and reduce the conductivity of the grain boundaries, leading to perovskite solar cells with reduced hysteresis and enhanced fill factor. A planar perovskite solar cell with grain boundary and interface passivation achieves a steady-state efficiency of 18.42%.

  11. Beryllium-7 and lead-210 chronometry of modern soil processes: The Linked Radionuclide aCcumulation model, LRC

    NASA Astrophysics Data System (ADS)

    Landis, Joshua D.; Renshaw, Carl E.; Kaste, James M.

    2016-05-01

    Soil systems are known to be repositories for atmospheric carbon and metal contaminants, but the complex processes that regulate the introduction, migration and fate of atmospheric elements in soils are poorly understood. This gap in knowledge is attributable, in part, to the lack of an established chronometer that is required for quantifying rates of relevant processes. Here we develop and test a framework for adapting atmospheric lead-210 chronometry (210Pb; half-life 22 years) to soil systems. We propose a new empirical model, the Linked Radionuclide aCcumulation model (LRC, aka "lark"), that incorporates measurements of beryllium-7 (7Be; half-life 54 days) to account for 210Pb penetration of the soil surface during initial deposition, a process which is endemic to soils but omitted from conventional 210Pb models (e.g., the Constant Rate of Supply, CRS model) and their application to sedimentary systems. We validate the LRC model using the 1963-1964 peak in bomb-fallout americium-241 (241Am; half-life of 432 years) as an independent, corroborating time marker. In three different soils we locate a sharp 241Am weapons horizon at disparate depths ranging from 2.5 to 6 cm, but with concordant ages averaging 1967 ± 4 via the LRC model. Similarly, at one site contaminated with mercury (HgT) we find that the LRC model is consistent with the recorded history of Hg emission. The close agreement of Pb, Am and Hg behavior demonstrated here suggests that organo-metallic colloid formation and migration incorporates many trace metals in universal soil processes and that these processes may be described quantitatively using atmospheric 210Pb chronometry. The 210Pb models evaluated here show that migration rates of soil colloids on the order of 1 mm yr-1 are typical, but also that these rates vary systematically with depth and are attributable to horizon-specific processes of leaf-litter decay, eluviation and illuviation. We thus interpret 210Pb models to quantify (i) exposure

  12. Another Link in the Chain: State Policies and Practices for Case Management and Environmental Investigation for Lead-Poisoned Children.

    ERIC Educational Resources Information Center

    Guthrie, Anne M.; McLaine, Pat

    Policy and practice for screening children for lead poisoning have dominated the dialogue about the health care system's role in lead poisoning prevention, with little attention directed to how the health care system responds to a lead-poisoned child once identified. This report details a study of the case management and environmental…

  13. Determination of arsenic, chromium, lead, manganese, and mercury in certifiable color additives by inductively coupled plasma/mass spectrometry.

    PubMed

    Hepp, Nancy Morris

    2015-01-01

    Specifications in the Code of Federal Regulations limit the levels of As, Pb, and Hg in most certifiable color additives, and some have additional specification limits for Cr and Mn. A new ICP/MS method was developed and validated for the quantitative determination of these elements in various certifiable color additives. One dissolution and two microwave-assisted digestion sample preparation procedures were optimized to address initial low Hg and enhanced As recoveries. Results using the three sample preparation procedures were generally equivalent for all of the elements determined. LOQ values were 0.3 mg/kg for As, 0.7 mg/kg for Cr, 0.4 mg/kg for Pb, 0.7 mg/kg for Mn, and 0.1 mg/kg for Hg.

  14. Targeted gene addition in human CD34(+) hematopoietic cells for correction of X-linked chronic granulomatous disease.

    PubMed

    De Ravin, Suk See; Reik, Andreas; Liu, Pei-Qi; Li, Linhong; Wu, Xiaolin; Su, Ling; Raley, Castle; Theobald, Narda; Choi, Uimook; Song, Alexander H; Chan, Andy; Pearl, Jocelynn R; Paschon, David E; Lee, Janet; Newcombe, Hannah; Koontz, Sherry; Sweeney, Colin; Shivak, David A; Zarember, Kol A; Peshwa, Madhusudan V; Gregory, Philip D; Urnov, Fyodor D; Malech, Harry L

    2016-04-01

    Gene therapy with genetically modified human CD34(+) hematopoietic stem and progenitor cells (HSPCs) may be safer using targeted integration (TI) of transgenes into a genomic 'safe harbor' site rather than random viral integration. We demonstrate that temporally optimized delivery of zinc finger nuclease mRNA via electroporation and adeno-associated virus (AAV) 6 delivery of donor constructs in human HSPCs approaches clinically relevant levels of TI into the AAVS1 safe harbor locus. Up to 58% Venus(+) HSPCs with 6-16% human cell marking were observed following engraftment into mice. In HSPCs from patients with X-linked chronic granulomatous disease (X-CGD), caused by mutations in the gp91phox subunit of the NADPH oxidase, TI of a gp91phox transgene into AAVS1 resulted in ∼15% gp91phox expression and increased NADPH oxidase activity in ex vivo-derived neutrophils. In mice transplanted with corrected HSPCs, 4-11% of human cells in the bone marrow expressed gp91phox. This method for TI into AAVS1 may be broadly applicable to correction of other monogenic diseases.

  15. Targeted gene addition in human CD34(+) hematopoietic cells for correction of X-linked chronic granulomatous disease.

    PubMed

    De Ravin, Suk See; Reik, Andreas; Liu, Pei-Qi; Li, Linhong; Wu, Xiaolin; Su, Ling; Raley, Castle; Theobald, Narda; Choi, Uimook; Song, Alexander H; Chan, Andy; Pearl, Jocelynn R; Paschon, David E; Lee, Janet; Newcombe, Hannah; Koontz, Sherry; Sweeney, Colin; Shivak, David A; Zarember, Kol A; Peshwa, Madhusudan V; Gregory, Philip D; Urnov, Fyodor D; Malech, Harry L

    2016-04-01

    Gene therapy with genetically modified human CD34(+) hematopoietic stem and progenitor cells (HSPCs) may be safer using targeted integration (TI) of transgenes into a genomic 'safe harbor' site rather than random viral integration. We demonstrate that temporally optimized delivery of zinc finger nuclease mRNA via electroporation and adeno-associated virus (AAV) 6 delivery of donor constructs in human HSPCs approaches clinically relevant levels of TI into the AAVS1 safe harbor locus. Up to 58% Venus(+) HSPCs with 6-16% human cell marking were observed following engraftment into mice. In HSPCs from patients with X-linked chronic granulomatous disease (X-CGD), caused by mutations in the gp91phox subunit of the NADPH oxidase, TI of a gp91phox transgene into AAVS1 resulted in ∼15% gp91phox expression and increased NADPH oxidase activity in ex vivo-derived neutrophils. In mice transplanted with corrected HSPCs, 4-11% of human cells in the bone marrow expressed gp91phox. This method for TI into AAVS1 may be broadly applicable to correction of other monogenic diseases. PMID:26950749

  16. Linking Traumatic Brain Injury to Chronic Traumatic Encephalopathy: Identification of Potential Mechanisms Leading to Neurofibrillary Tangle Development

    PubMed Central

    Lucke-Wold, Brandon Peter; Turner, Ryan Coddington; Logsdon, Aric Flint; Bailes, Julian Edwin; Huber, Jason Delwyn

    2014-01-01

    Abstract Significant attention has recently been drawn to the potential link between head trauma and the development of neurodegenerative disease, namely chronic traumatic encephalopathy (CTE). The acute neurotrauma associated with sports-related concussions in athletes and blast-induced traumatic brain injury in soldiers elevates the risk for future development of chronic neurodegenerative diseases such as CTE. CTE is a progressive disease distinguished by characteristic tau neurofibrillary tangles (NFTs) and, occasionally, transactive response DNA binding protein 43 (TDP43) oligomers, both of which have a predilection for perivascular and subcortical areas near reactive astrocytes and microglia. The disease is currently only diagnosed postmortem by neuropathological identification of NFTs. A recent workshop sponsored by National Institute of Neurological Disorders and Stroke emphasized the need for premortem diagnosis, to better understand disease pathophysiology and to develop targeted treatments. In order to accomplish this objective, it is necessary to discover the mechanistic link between acute neurotrauma and the development of chronic neurodegenerative and neuropsychiatric disorders such as CTE. In this review, we briefly summarize what is currently known about CTE development and pathophysiology, and subsequently discuss injury-induced pathways that warrant further investigation. Understanding the mechanistic link between acute brain injury and chronic neurodegeneration will facilitate the development of appropriate diagnostic and therapeutic options for CTE and other related disorders. PMID:24499307

  17. Evaluation of calcium and lead interaction, in addition to their impact on thyroid functions in hyper and hypothyroid patients.

    PubMed

    Memon, Nusrat Shahab; Kazi, Tasneem Gul; Afridi, Hassan Imran; Baig, Jameel Ahmed; Arain, Sadaf Sadia; Sahito, Oan Muhammad; Baloch, Shahnawaz; Waris, Muhammad

    2016-01-01

    There is compelling evidence in support of interaction between calcium (Ca) and lead (Pb) in thyroid disorders. The aim of present study was to compare the level of Ca and Pb with thyroid hormones such as thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxin (FT4) in serum samples of hyperthyroid (HPRT) and hypothyroid (HPOT) patients of both genders. For comparative purpose, age-matched (25-50 years) subjects having no thyroid disorders were selected as referents/controls. The serum samples were acid-digested prior to analysis by atomic absorption spectrometry. The validity and accuracy of the methodology were checked by certified reference materials. The resulted data indicates that the mean values of Ca in serum samples of HPRT patients were significantly higher than those of referent subjects (p < 0.01), while reverse pattern was observed in the case of HPOT patients. The level of Pb was higher in the serum samples of both types of thyroid patients, but difference was significant in case of HPOT patients as compare to referent subjects (p < 0.01). A negative correlation was observed between serum Ca levels and TSH of HPRT patients (-r = 0.37-0.39, p < 0.01), while FT3 and FT4 have positive correlation (r = 0.49-0.52 and r = 0.46-0.47), p values <0.01. The Pb in serum had positive correlation with TSH (r = 0.48-0.51, p < 0.005), while negative correlation was observed for FT3 and FT4 (-r = 0.55-0.56, 0.5-0.54, p < 0.05) in HPRT patients. On the other hand, a reverse pattern was observed, for correlation of Ca and Pb with thyroid functions in HPOT patients. PMID:26347420

  18. Investigation of Cross-Linked and Additive Containing Polymer Materials for Membranes with Improved Performance in Pervaporation and Gas Separation

    PubMed Central

    Hunger, Katharina; Schmeling, Nadine; Jeazet, Harold B. Tanh; Janiak, Christoph; Staudt, Claudia; Kleinermanns, Karl

    2012-01-01

    Pervaporation and gas separation performances of polymer membranes can be improved by crosslinking or addition of metal-organic frameworks (MOFs). Crosslinked copolyimide membranes show higher plasticization resistance and no significant loss in selectivity compared to non-crosslinked membranes when exposed to mixtures of CO2/CH4 or toluene/cyclohexane. Covalently crosslinked membranes reveal better separation performances than ionically crosslinked systems. Covalent interlacing with 3-hydroxypropyldimethylmaleimide as photocrosslinker can be investigated in situ in solution as well as in films, using transient UV/Vis and FTIR spectroscopy. The photocrosslinking yield can be determined from the FTIR-spectra. It is restricted by the stiffness of the copolyimide backbone, which inhibits the photoreaction due to spatial separation of the crosslinker side chains. Mixed-matrix membranes (MMMs) with MOFs as additives (fillers) have increased permeabilities and often also selectivities compared to the pure polymer. Incorporation of MOFs into polysulfone and Matrimid® polymers for MMMs gives defect-free membranes with performances similar to the best polymer membranes for gas mixtures, such as O2/N2 H2/CH4, CO2/CH4, H2/CO2, CH4/N2 and CO2/N2 (preferentially permeating gas is named first). The MOF porosity, its particle size and content in the MMM are factors to influence the permeability and the separation performance of the membranes. PMID:24958427

  19. Linking process, structure, property, and performance for metal-based additive manufacturing: computational approaches with experimental support

    NASA Astrophysics Data System (ADS)

    Smith, Jacob; Xiong, Wei; Yan, Wentao; Lin, Stephen; Cheng, Puikei; Kafka, Orion L.; Wagner, Gregory J.; Cao, Jian; Liu, Wing Kam

    2016-04-01

    Additive manufacturing (AM) methods for rapid prototyping of 3D materials (3D printing) have become increasingly popular with a particular recent emphasis on those methods used for metallic materials. These processes typically involve an accumulation of cyclic phase changes. The widespread interest in these methods is largely stimulated by their unique ability to create components of considerable complexity. However, modeling such processes is exceedingly difficult due to the highly localized and drastic material evolution that often occurs over the course of the manufacture time of each component. Final product characterization and validation are currently driven primarily by experimental means as a result of the lack of robust modeling procedures. In the present work, the authors discuss primary detrimental hurdles that have plagued effective modeling of AM methods for metallic materials while also providing logical speculation into preferable research directions for overcoming these hurdles. The primary focus of this work encompasses the specific areas of high-performance computing, multiscale modeling, materials characterization, process modeling, experimentation, and validation for final product performance of additively manufactured metallic components.

  20. Knockdown of {alpha}II spectrin in normal human cells by siRNA leads to chromosomal instability and decreased DNA interstrand cross-link repair

    SciTech Connect

    McMahon, Laura W.; Zhang Pan; Sridharan, Deepa M.; Lefferts, Joel A.; Lambert, Muriel W.

    2009-04-03

    Nonerythroid {alpha}-spectrin ({alpha}IISp) is a structural protein involved in repair of DNA interstrand cross-links and is deficient in cells from patients with Fanconi anemia (FA), which are defective in ability to repair cross-links. In order to further demonstrate the importance of the role that {alpha}IISp plays in normal human cells and in the repair defect in FA, {alpha}IISp was knocked down in normal cells using siRNA. Depletion of {alpha}IISp in normal cells by siRNA resulted in chromosomal instability and cellular hypersensitivity to DNA interstrand cross-linking agents. An increased number of chromosomal aberrations were observed and, following treatment with a DNA interstrand cross-linking agent, mitomycin C, cells showed decreased cell growth and survival and decreased formation of damage-induced {alpha}IISp and XPF nuclear foci. Thus depletion of {alpha}IISp in normal cells leads to a number of defects observed in FA cells, such as chromosome instability and a deficiency in cross-link repair.

  1. TRPA1 activation leads to neurogenic vasodilatation: involvement of reactive oxygen nitrogen species in addition to CGRP and NO

    PubMed Central

    Aubdool, Aisah A; Kodji, Xenia; Abdul‐Kader, Nayaab; Heads, Richard; Fernandes, Elizabeth S; Bevan, Stuart

    2016-01-01

    Abstract Background and Purpose Transient receptor potential ankyrin‐1 (TRPA1) activation is known to mediate neurogenic vasodilatation. We investigated the mechanisms involved in TRPA1‐mediated peripheral vasodilatation in vivo using the TRPA1 agonist cinnamaldehyde. Experimental Approach Changes in vascular ear blood flow were measured in anaesthetized mice using laser Doppler flowmetry. Key Results Topical application of cinnamaldehyde to the mouse ear caused a significant increase in blood flow in the skin of anaesthetized wild‐type (WT) mice but not in TRPA1 knockout (KO) mice. Cinnamaldehyde‐induced vasodilatation was inhibited by the pharmacological blockade of the potent microvascular vasodilator neuropeptide CGRP and neuronal NOS‐derived NO pathways. Cinnamaldehyde‐mediated vasodilatation was significantly reduced by treatment with reactive oxygen nitrogen species (RONS) scavenger such as catalase and the SOD mimetic TEMPOL, supporting a role of RONS in the downstream vasodilator TRPA1‐mediated response. Co‐treatment with a non‐selective NOS inhibitor L‐NAME and antioxidant apocynin further inhibited the TRPA1‐mediated vasodilatation. Cinnamaldehyde treatment induced the generation of peroxynitrite that was blocked by the peroxynitrite scavenger FeTPPS and shown to be dependent on TRPA1, as reflected by an increase in protein tyrosine nitration in the skin of WT, but not in TRPA1 KO mice. Conclusion and Implications This study provides in vivo evidence that TRPA1‐induced vasodilatation mediated by cinnamaldehyde requires neuronal NOS‐derived NO, in addition to the traditional neuropeptide component. A novel role of peroxynitrite is revealed, which is generated downstream of TRPA1 activation by cinnamaldehyde. This mechanistic pathway underlying TRPA1‐mediated vasodilatation may be important in understanding the role of TRPA1 in pathophysiological situations. PMID:27189253

  2. Enhanced performance of starter lighting ignition type lead-acid batteries with carbon nanotubes as an additive to the active mass

    NASA Astrophysics Data System (ADS)

    Marom, Rotem; Ziv, Baruch; Banerjee, Anjan; Cahana, Beni; Luski, Shalom; Aurbach, Doron

    2015-11-01

    Addition of various carbon materials into lead-acid battery electrodes was studied and examined in order to enhance the power density, improve cycle life and stability of both negative and positive electrodes in lead acid batteries. High electrical-conductivity, high-aspect ratio, good mechanical properties and chemical stability of multi-wall carbon nanotubes (MWCNT, unmodified and mofified with carboxylic groups) position them as viable additives to enhance the electrodes' electrical conductivity, to mitigate the well-known sulfation failure mechanism and improve the physical integration of the electrodes. In this study, we investigated the incorporation-effect of carbon nanotubes (CNT) to the positive and the negative active materials in lead-acid battery prototypes in a configuration of flooded cells, as well as gelled cells. The cells were tested at 25% and 30% depth-of-discharge (DOD). The positive effect of the carbon nanotubes (CNT) utilization as additives to both positive and negative electrodes of lead-acid batteries was clearly demonstrated and is explained herein based on microscopic studies.

  3. Fade statistics of a ground-to-satellite optical link in the presence of lead-ahead and aperture mismatch.

    PubMed

    Basu, Santasri; Voelz, David; Borah, Deva K

    2009-03-01

    In a recent publication [J. Opt. Soc. Am. A25, 1594-1608 (2008).JOAOD60740-323210.1364/JOSAA.25.001594] we developed expressions for the tilt errors that arise from the effects of lead-ahead and aperture mismatch when transmitting a laser beam from the ground to a satellite. We extend these results to examine the fade statistics of the irradiance at the satellite due to these tilt errors and turbulence induced scintillation. The system concept is that the light from a beacon on the satellite is received by the ground station and a derived signal is used to drive a tracking/pointing system for the uplink beam. However, the beam must be pointed ahead along the satellite track to intercept the satellite (lead-ahead), and physical constraints may require that the beam transmit aperture is different in size or location than the aperture receiving the beacon signal (aperture mismatch). These two issues cause the light entering the receiving aperture (tracker) and the beam exiting the transmit aperture (pointer) to traverse somewhat different turbulence volumes, which limits the ability of the tracking/pointing system to place the maximum flux on the satellite.

  4. Does Traumatic Brain Injury Lead to Criminality? A Whole-Population Retrospective Cohort Study Using Linked Data

    PubMed Central

    Schofield, Peter W.; Malacova, Eva; Preen, David B.; D’Este, Catherine; Tate, Robyn; Reekie, Joanne; Wand, Handan; Butler, Tony

    2015-01-01

    Background Traumatic brain injury (TBI) may be a risk factor for criminal behaviour however multiple factors potentially confound the association. Methods Record linkage and Cox proportional hazards regression analyses were used to examine the association between hospital-recorded TBI (n = 7,694) and subsequent first criminal conviction in a retrospective cohort matched 1:3 with 22,905 unaffected community controls and full-sibling controls (n = 2,397). Aboriginality, substance abuse, social disadvantage, and mental illness were included in analyses as potential confounders Results In multivariable models, relative to general population controls, TBI was associated with any conviction (males: Hazard Ratio (HR) = 1·58 (95% CI 1·46 to 1·72); females: HR = 1·52 (95% CI 1·28 to 1·81)); and similar Hazard Ratios were obtained for the sibling analyses in males (HR = 1.68 (95% CI 1.31-2.18)) and females (HR 1.27 (95% CI 0.71-2.29)). TBI was also associated with violent convictions relative to the general population, (males: HR = 1.65 (95% CI 1.42 to 1.92); females HR = 1.73 (95% CI 1.21 to 2.47)), and in analyses with sibling controls in men (HR = 1.89 (95% CI 1.20-3.00)), but not in women (HR 0.73, 95% CI 0.29-1.81)). Conclusion The results support a modest causal link between TBI and criminality after comprehensive adjustment for confounding. Reducing the rate of TBI, a major public health imperative, might have benefits in terms of crime reduction. PMID:26172545

  5. Radiation-Induced RhoGDIβ Cleavage Leads to Perturbation of Cell Polarity: A Possible Link to Cancer Spreading.

    PubMed

    Fujiwara, Mamoru; Okamoto, Mayumi; Hori, Masato; Suga, Hiroshi; Jikihara, Hiroshi; Sugihara, Yuka; Shimamoto, Fumio; Mori, Toshio; Nakaoji, Koichi; Hamada, Kazuhiko; Ota, Takahide; Wiedemuth, Ralf; Temme, Achim; Tatsuka, Masaaki

    2016-11-01

    The equilibrium between proliferation and apoptosis is tightly balanced to maintain tissue homeostasis in normal tissues and even in tumors. Achieving and maintaining such a balance is important for cancer regrowth and spreading after cytotoxic treatments. Caspase-3 activation and tumor cell death following anticancer therapy as well as accompanying cell death pathways are well characterized, but their association to homeostasis of cancerous tissue and tumor progression remains poorly understood. Here we proposed a novel mechanism of cancer spreading induced by caspase-3. RhoGDIβ, known as a direct cleavage substrate of caspase-3, is overexpressed in many epithelial cancers. The N-terminal-truncated RhoGDIβ (ΔN-RhoGDIβ) is accumulated in caspase-3-activated cells. Stable expression of ΔN-RhoGDIβ in HeLa cells did not induce apoptosis, but impaired directional cell migration in a wound-healing assay accompanied by a perturbed direction of cell division at the wound edge. Subcellular protein fractionation experiments revealed that ΔN-RhoGDIβ but not wild-type RhoGDIβ was present in the detergent-soluble cytoplasmic and nuclear fractions and preferentially associated with Cdc42. Furthermore, Cdc42 activity was constitutively inhibited by stable expression of ΔN-RhoGDIβ, resulting in increased radiation-induced compensatory proliferation linking to RhoA activation. Thus, ΔN-RhoGDIβ dominant-negatively regulates Cdc42 activity and contributes to loss of polarity-related functions. The caspase-3-cleaved RhoGDIβ is a possible determinant to promote cancer spreading due to deregulation of directional organization of tumor cell population and inhibition of default equilibrium between proliferation and apoptosis after cytotoxic damage. J. Cell. Physiol. 231: 2493-2505, 2016. © 2016 Wiley Periodicals, Inc.

  6. A mutation that prevents glucosylation of the lipid-linked oligosaccharide precursor leads to underglycosylation of secreted yeast invertase.

    PubMed Central

    Ballou, L; Gopal, P; Krummel, B; Tammi, M; Ballou, C E

    1986-01-01

    A mutant of Saccharomyces cerevisiae with the genotype mnn1 mnn2 mnn9 gls1 synthesizes mannoproteins with oligosaccharides having the composition Glc3Man10Glc-NAc2- owing to the mnn9 defect, which prevents synthesis of the outer chain, the mnn1 defect, which prevents branching of the core, and the gls1 mutation, which prevents deglucosylation of the resultant glycoprotein as a consequence of a defective glucosidase-I [Tsai, P.-K., Ballou, L., Esmon, B., Schekman, R. & Ballou, C. E. (1984) Proc. Natl. Acad. Sci. USA 81, 6340-6343]. (The mnn2 defect is not expressed in presence of the mnn9 mutation.) This strain spontaneously forms new colonies in which gls1 is suppressed owing to a defect in synthesis of dolichol phosphoglucose, the glucosylation substrate. The new mutant, designated mnn1 mnn2 mnn9 gls1 dpg1, synthesizes and secretes invertase (EC 3.2.1.26) that has a higher mobility on native gel electrophoresis than that made by the parent strain, the consequence of a reduction in both the size and the number of carbohydrate chains. The mannoprotein chains have the mnn1 mnn9 structure (Man10Glc-NAc2-), and the invertase is resolved by gel electrophoresis in sodium dodecyl sulfate into two major and two minor bands that represent homologs with about 4-7 carbohydrate units, in contrast to about 8-11 chains in the parent strain. Thus, the inability to glucosylate the lipid-linked precursor reduces the efficiency of glycosylation of the protein chains. The genetic defect is in synthesis of the glucose donor dolichol phosphoglucose, but the mutation is nonallelic with the reported alg5-1 mutation, which has a similar phenotype [Runge, K. W., Huffaker, T. C. & Robbins, P. W. (1984) J. Biol. Chem. 259, 412-417]. Images PMID:3517849

  7. Germline or somatic GPR101 duplication leads to X-linked acrogigantism: a clinico-pathological and genetic study.

    PubMed

    Iacovazzo, Donato; Caswell, Richard; Bunce, Benjamin; Jose, Sian; Yuan, Bo; Hernández-Ramírez, Laura C; Kapur, Sonal; Caimari, Francisca; Evanson, Jane; Ferraù, Francesco; Dang, Mary N; Gabrovska, Plamena; Larkin, Sarah J; Ansorge, Olaf; Rodd, Celia; Vance, Mary L; Ramírez-Renteria, Claudia; Mercado, Moisés; Goldstone, Anthony P; Buchfelder, Michael; Burren, Christine P; Gurlek, Alper; Dutta, Pinaki; Choong, Catherine S; Cheetham, Timothy; Trivellin, Giampaolo; Stratakis, Constantine A; Lopes, Maria-Beatriz; Grossman, Ashley B; Trouillas, Jacqueline; Lupski, James R; Ellard, Sian; Sampson, Julian R; Roncaroli, Federico; Korbonits, Márta

    2016-01-01

    Non-syndromic pituitary gigantism can result from AIP mutations or the recently identified Xq26.3 microduplication causing X-linked acrogigantism (XLAG). Within Xq26.3, GPR101 is believed to be the causative gene, and the c.924G > C (p.E308D) variant in this orphan G protein-coupled receptor has been suggested to play a role in the pathogenesis of acromegaly.We studied 153 patients (58 females and 95 males) with pituitary gigantism. AIP mutation-negative cases were screened for GPR101 duplication through copy number variation droplet digital PCR and high-density aCGH. The genetic, clinical and histopathological features of XLAG patients were studied in detail. 395 peripheral blood and 193 pituitary tumor DNA samples from acromegaly patients were tested for GPR101 variants.We identified 12 patients (10 females and 2 males; 7.8 %) with XLAG. In one subject, the duplicated region only contained GPR101, but not the other three genes in found to be duplicated in the previously reported patients, defining a new smallest region of overlap of duplications. While females presented with germline mutations, the two male patients harbored the mutation in a mosaic state. Nine patients had pituitary adenomas, while three had hyperplasia. The comparison of the features of XLAG, AIP-positive and GPR101&AIP-negative patients revealed significant differences in sex distribution, age at onset, height, prolactin co-secretion and histological features. The pathological features of XLAG-related adenomas were remarkably similar. These tumors had a sinusoidal and lobular architecture. Sparsely and densely granulated somatotrophs were admixed with lactotrophs; follicle-like structures and calcifications were commonly observed. Patients with sporadic of familial acromegaly did not have an increased prevalence of the c.924G > C (p.E308D) GPR101 variant compared to public databases.In conclusion, XLAG can result from germline or somatic duplication of GPR101. Duplication of GPR101

  8. Computer analysis of the binding reactions leading to a transmembrane receptor-linked multiprotein complex involved in bacterial chemotaxis.

    PubMed Central

    Bray, D; Bourret, R B

    1995-01-01

    The chemotactic response of bacteria is mediated by complexes containing two molecules each of a transmembrane receptor and the intracellular signaling proteins CheA and CheW. Mutants in which one or the other of the proteins of this complex are absent, inactive, or expressed at elevated amounts show altered chemotactic behavior and the phenotypes are difficult to interpret for some overexpression mutants. We have examined the possibility that these unexpected phenotypes might arise from the binding steps that lead to active complex formation. A limited genetic algorithm was used to search for sets of binding reactions and associated binding constants expected to give mutant phenotypes in accord with experimental data. Different sets of binding equilibria and different assumptions about the activity of particular receptor complexes were tried. Computer analysis demonstrated that it is possible to obtain sets of binding equilibria consistent with the observed phenotypes and provided a simple explanation for these phenotypes in terms of the distribution of active and inactive complexes formed under various conditions. Optimization methods of this kind offer a unique way to analyze reactions taking place inside living cells based on behavioral data. PMID:8573792

  9. Phosphorylation and interaction of Myopodin by Integrin-Link Kinase Lead to Suppression of Cell Growth and Motility in Prostate Cancer Cells

    PubMed Central

    Yu, Yan-Ping; Luo, Jian-Hua

    2011-01-01

    Myopodin is a tumor suppressor gene that suppresses growth of prostate and urothelial carcinomas. However, the mechanism of myopodin tumor suppressor activity or signaling that leads to activation of myopodin remains unclear. In this report, we showed that the N-terminus of myopodin binds integrin-linked kinase (ILK) both in vivo and in vitro. An ILK interaction motif of 78 amino acids (amino acids 82–157) was identified in the N-terminus region of myopodin. Induction of ILK dependent kinase activity by integrin α7 led to phosphorylation of myopodin both in vivo and in vitro. Knocking down ILK dramatically reduced the inhibition of cell growth and motility mediated by myopodin. A mutant of myopodin lacking the ILK interaction motif is inactive in suppressing the growth and motility of PC3 cells. As a result, this study showed a novel and critical signaling pathway that leads to activation of myopodin. PMID:21643011

  10. Loss-of-function mutation in the X-linked TBX22 promoter disrupts an ETS-1 binding site and leads to cleft palate.

    PubMed

    Fu, Xiazhou; Cheng, Yibin; Yuan, Jia; Huang, Chunhua; Cheng, Hanhua; Zhou, Rongjia

    2015-02-01

    The cleft palate only (CPO) is a common congenital defect with complex etiology in humans. The molecular etiology of the CPO remains unknown. Here, we report a loss-of-function mutation in X-linked TBX22 gene (T-box 22) in a six-generation family of the CPO with obvious phenotypes of both cleft palate and hyper-nasal speech. We identify a functional -73G>A mutation in the promoter of TBX22, which is located at the core-binding site of transcription factor ETS-1 (v-ets avian erythroblastosis virus E26 oncogene homolog 1). Phylogenetic analysis showed that the sequence around the -73G>A mutation site is specific in primates. The mutation was detected in all five affected male members cosegregating with the affected phenotype and heterozygote occurred only in some unaffected females of the family, suggesting an X-linked transmission of the mutation in the family. The -73G>A variant is a novel single nucleotide mutation. Cell co-transfections indicated that ETS-1 could activate the TBX22 promoter. Moreover, EMSA and ChIP assays demonstrated that the allele A disrupts the binding site of ETS-1, thus markedly decreases the activity of the TBX22 promoter, which is likely to lead to the birth defect of the CPO without ankyloglossia. These results suggest that a loss-of-function mutation in the X-linked TBX22 promoter may cause the cleft palate through disruption of TBX22-ETS-1 pathway.

  11. Tracking in a ground-to-satellite optical link: effects due to lead-ahead and aperture mismatch, including temporal tracking response.

    PubMed

    Basu, Santasri; Voelz, David

    2008-07-01

    Establishing a link between a ground station and a geosynchronous orbiting satellite can be aided greatly with the use of a beacon on the satellite. A tracker, or even an adaptive optics system, can use the beacon during communication or tracking activities to correct beam pointing for atmospheric turbulence and mount jitter effects. However, the pointing lead-ahead required to illuminate the moving object and an aperture mismatch between the tracking and the pointing apertures can limit the effectiveness of the correction, as the sensed tilt will not be the same as the tilt required for optimal transmission to the satellite. We have developed an analytical model that addresses the combined impact of these tracking issues in a ground-to-satellite optical link. We present these results for different tracker/pointer configurations. By setting the low-pass cutoff frequency of the tracking servo properly, the tracking errors can be minimized. The analysis considers geosynchronous Earth orbit satellites as well as low Earth orbit satellites.

  12. A pilot study on the incidence of severe photosensitivity reactions leading to hospitalization linked to topical ketoprofen and other medications in selected European regions.

    PubMed

    Cazzaniga, Simone; Naldi, Luigi; Lecchi, Silvia; Kürzinger, Marie-Laure; Auclert, Laurent; Gori, Mario; Chosidow, Olivier; Hercogova, Jana

    2016-06-01

    The aim of this study was to assess the prevalence of exposure to topical nonsteroidal anti-inflammatory drugs (NSAIDs), particularly ketoprofen, in a convenience sample of the population, to obtain estimates of the incidence of severe photosensitivity leading to hospitalization, and to assess causative factors in three catchment areas: the Paris metropolitan area, the Lombardy region (Italy) and the Prague area. All cases of severe photosensitivity not explained by underlying conditions and admitted to hospitals in the selected areas were included in the study. Controls were patients consecutively admitted to hospitals, in the same areas, for an acute condition or for an elective procedure not suspected of being related to medication use. From October 2012 to September 2013, 920 controls were recruited (median age 44 years, 50.8% females); 8 severe photosensitivity cases were reported in the population aged 18-74 years of the 3 geographical areas during the 1-year surveillance period, corresponding to an incidence rate of 4.81 cases per 10 million person-years (95% confidence interval - CI, 2.07-9.48). Six controls reported 1-month exposure to topical ketoprofen, with an estimated prevalence of 0.65% (95% CI, 0.24-1.42). The population attributable risk for severe photosensitivity reactions linked to ketoprofen was 11.92% (95% CI, -0.12-52.99). This study was conducted in selected European areas and showed that the incidence of severe photosensitivity reactions leading to hospitalization as well as the exposure rate to topical ketoprofen were low. Among topical NSAIDs, topical ketoprofen was the leading cause of photosensitivity reactions but accounted for a limited number of hospitalized cases. Probably most of the relevant reactions were managed in the outpatient setting and a community based case-control study is advisable.

  13. Where Will LEAD Lead?

    ERIC Educational Resources Information Center

    Wildman, Louis

    After setting forth eight assumptions concerning the education of educational administrators, findings about the Leadership in Educational Administration Development (LEAD) program are discussed. The analysis is based on the first-year applications, telephone conversations with staff at a majority of the project sites, and additional material…

  14. Cross-linking of IgGs bound on circulating neutrophils leads to an activation of endothelial cells: possible role of rheumatoid factors in rheumatoid arthritis-associated vascular dysfunction

    PubMed Central

    2013-01-01

    Background Rheumatoid arthritis is characterized by the presence of circulating auto-antibodies, including rheumatoid factors, which recognize the Fc portion of IgGs. The neutrophil is the most abundant circulating leukocyte and it expresses high levels of FcγRs on its surface. The aim of the present study was to examine the capacity of circulating human neutrophils to be activated by rheumatoid factors and the consequences of these events on endothelium. Methods Neutrophil-bound IgGs were cross-linked with anti-human IgGs to mimick the presence of circulating rheumatoid factors and FcγRs-dependent signalling events and functions were examined. The IgG and IgM composition of rheumatoid factors isolated from the serum of RA patients was characterized. Adhesion of neutrophils to endothelial cells was quantified in response to the addition of rheumatoid factors. Results Cross-linking of IgGs bound on neutrophils leads to FcγRs-dependent tyrosine phosphorylation, mobilisation of intracellular calcium and the extracellular release of superoxide anions and lysozyme. Incubation of endothelial cells with the supernatant of activated neutrophils increases ICAM-1 expression and IL-8 production by endothelial cells. Finally, rheumatoid factors enhance neutrophil adhesion to endothelial cells. Conclusions Our results show that activation of neutrophils’ FcγRs by rheumatoid factors could participate in rheumatoid arthritis-associated vascular damage. PMID:23902799

  15. Thermal formation of PBDD/F from tetrabromobisphenol A--a comparison of polymer linked TBBP A with its additive incorporation in thermoplastics.

    PubMed

    Wichmann, H; Dettmer, F T; Bahadir, M

    2002-04-01

    For a long period, polybrominated flame retardants are under discussion because of the formation of polybrominated dibenzo-p-dioxins (PBDD)/dibenzofurans (PBDF) (PBDD/F) in case of thermal stress. Concerning polymer linked tetrabromobisphenol A (TBBP A), formation of PBDD/F was commonly presumed to be sterically hindered because of the covalent fixation into the polymer backbone. Combustion experiments with additively incorporated TBBP A compared with its polymer linkage revealed, that this assumption is incorrect and has to be revised. Under same conditions, similar PBDD/F concentrations in the range of 17.5-19.6 mg PBBD/F per kg TBBP A applied were analyzed. PBDD/F homologue distribution patterns were almost identical predominated by low brominated PBDF. These findings for PBDD/F formation have to be considered in future discussions regarding thermal stress caused by combustion or recycling processes, including other flame retardants bound in polymer matrix, e.g. polybrominated polystyrene (PS), or those with molecular structures showing less analogy to PBDD/F, like hexabromocyclododecane. The second aspect introduced, is the influence of different plastics on the formation rates of PBDD/F. In this context, combustion experiments were performed in an atmosphere consisting of synthetic air and HBr. PBDD/F concentrations were 8.47 mg/kg polyethylene, 1.67 mg/kg PS, 3.92 mg/kg phenolic resin and 18.1 mg/kg epoxy resin. Distribution patterns of PBDD/F homologues could partly be correlated with the occurrence of the precursors polybrominated benzenes and phenols.

  16. Effect of Pr Addition on Properties of Sn-0.5Ag-0.7Cu-0.5Ga Lead-Free Solder

    NASA Astrophysics Data System (ADS)

    Xujing, Nan; Songbai, Xue; Peizhuo, Zhai; Dongxue, Luo

    2016-10-01

    In this paper, the effect of Pr addition on the microstructure and properties of Sn-0.5Ag-0.7Cu-0.5Ga lead-free solder was investigated. It was found that the properties of Sn-0.5Ag-0.7Cu-0.5Ga- xPr solder, such as wettability and mechanical properties, could be obviously improved, and the optimal content of Pr was about 0.06 wt.%. The microstructure of Sn-0.5Ag-0.7Cu-0.5Ga-0.06Pr solder showed that the β-Sn matrix and intermetallic compound (IMC) grains were significantly refined, and refinement and homogenization of the microstructure achieved maximum efficiency, which played the role of fine grain strengthening and second phase strengthening. However, as the content of Pr exceeded 0.06 wt.%, some uneven distributed black phases of PrSn3 were found in the β-Sn matrix, which seriously worsened the microstructure and properties of the solders. As a surface-active element, the segregation of Pr at the molten solder interface could give rise to decreasing the interface tension. Consequently, adding a suitable amount of Pr could play a positive role in improving the properties of the solders.

  17. Effect of Pr Addition on Properties of Sn-0.5Ag-0.7Cu-0.5Ga Lead-Free Solder

    NASA Astrophysics Data System (ADS)

    Xujing, Nan; Songbai, Xue; Peizhuo, Zhai; Dongxue, Luo

    2016-07-01

    In this paper, the effect of Pr addition on the microstructure and properties of Sn-0.5Ag-0.7Cu-0.5Ga lead-free solder was investigated. It was found that the properties of Sn-0.5Ag-0.7Cu-0.5Ga-xPr solder, such as wettability and mechanical properties, could be obviously improved, and the optimal content of Pr was about 0.06 wt.%. The microstructure of Sn-0.5Ag-0.7Cu-0.5Ga-0.06Pr solder showed that the β-Sn matrix and intermetallic compound (IMC) grains were significantly refined, and refinement and homogenization of the microstructure achieved maximum efficiency, which played the role of fine grain strengthening and second phase strengthening. However, as the content of Pr exceeded 0.06 wt.%, some uneven distributed black phases of PrSn3 were found in the β-Sn matrix, which seriously worsened the microstructure and properties of the solders. As a surface-active element, the segregation of Pr at the molten solder interface could give rise to decreasing the interface tension. Consequently, adding a suitable amount of Pr could play a positive role in improving the properties of the solders.

  18. In vitro digestion/Caco-2 cell model to estimate cadmium and lead bioaccessibility/bioavailability in two vegetables: the influence of cooking and additives.

    PubMed

    Fu, Jin; Cui, Yanshan

    2013-09-01

    The estimation of heavy metal bioaccessibility and bioavailability in vegetables is helpful for human health risk assessment. Using an in vitro digestion/Caco-2 cell model, the bioaccessibility and bioavailability of cadmium (Cd) and lead (Pb) in raw/cooked pakchoi (Brassica rapa L., Chinensis Group) and Malabar spinach (Basella rubra L.) were studied. The effect of the addition of iron, calcium and acetic acid to the samples was also determined. The results indicated that Cd bioaccessibility was higher in the gastric phase and Pb bioaccessibility was higher in the small intestinal phase. Cadmium and Pb bioavailability were 11.2% and 9.4% in the raw vegetables, respectively, and found to be higher significantly than the cooked vegetables with 6.1% for Cd and 3.2% for Pb. The results showed that it will be overestimating the risk of Pb and Cd based on the data of raw vegetables ingestion. Using bioavailability values, average Cd and Pb daily intake by adult were 23% and 28% respectively, of the base bioaccessibility values. Our study will be better understanding the possible health risks of some vegetables base on the bioaccessibility or bioavailability.

  19. Effect of Zn and Sb Additions on the Impression Creep Behavior of Lead-Free Sn-3.5Ag Solder Alloy

    NASA Astrophysics Data System (ADS)

    Pourmajidian, M.; Mahmudi, R.; Geranmayeh, A. R.; Hashemizadeh, S.; Gorgannejad, S.

    2016-01-01

    The effect of separate additions of 1.5 wt.% Zn and 1.5 wt.% Sb on the creep behavior of Sn-3.5 wt.% Ag lead-free solder alloy was investigated by impression testing. The tests were carried out under constant punching stresses in the range of 60-120 MPa and at temperatures in the range of 298-370 K. Both of the ternary alloys showed creep resistances higher than that of the eutectic binary Sn-3.5Ag alloy. The superior creep resistance of the ternary Sn-3.5Ag-1.5Sb alloy is attributed to the strong solid solutioning effect of antimony in the tin matrix, while the formation of AgZn particles and refinement of the Ag3Sn precipitates account for the higher creep resistance of the Sn-3.5Ag-1.5Zn alloy. The average stress exponents of 8.2, 8.5, and 8.6 and activation energies of 47.4 kJ mol-1, 45.3 kJ mol-1, , and 43.3 kJ mol-1 were obtained for Sn-3.5Ag, Sn-3.5Ag-1.5Zn, and Sn-3.5Ag-1.5Sb, respectively. These activation energies are close to 46 kJ mol-1 for dislocation pipe diffusion of tin. This, together with the stress exponents of 8.2-8.6, suggests that dislocation climb controlled by dislocation pipe diffusion is the predominant creep mechanism in these alloys.

  20. X-ray recordings reveal how a human disease-linked skeletal muscle α-actin mutation leads to contractile dysfunction.

    PubMed

    Ochala, Julien; Ravenscroft, Gianina; McNamara, Elyshia; Nowak, Kristen J; Iwamoto, Hiroyuki

    2015-12-01

    In humans, mutant skeletal muscle α-actin proteins are associated with contractile dysfunction, skeletal muscle weakness and a wide range of primarily skeletal muscle diseases. Despite this knowledge, the exact molecular mechanisms triggering the contractile dysfunction remain unknown. Here, we aimed to unravel these. Hence, we used a transgenic mouse model expressing a well-described D286G mutant skeletal muscle α-actin protein and recapitulating the human condition of contractile deregulation and severe skeletal muscle weakness. We then recorded and analyzed the small-angle X-ray diffraction patterns of isolated membrane-permeabilized myofibers. Results showed that upon addition of Ca(2+), the intensity changes of the second (1/19 nm(-1)) and sixth (1/5.9 nm(-1)) actin layer lines and of the first myosin meridional reflection (1/14.3 nm(-1)) were disrupted when the thin-thick filament overlap was optimal (sarcomere length of 2.5-2.6 μm). However these reflections were normal when the thin and thick filaments were not interacting (sarcomere length>3.6 μm). These findings demonstrate, for the first time, that the replacement of just one amino acid in the skeletal muscle α-actin protein partly prevents actin conformational changes during activation, disrupting the strong binding of myosin molecules. This leads to a limited myosin-related tropomyosin movement over the thin filaments, further affecting the amount of cross-bridges, explaining the contractile dysfunction. PMID:26407659

  1. Spectrum of X-linked hydrocephalus (HSAS), MASA syndrome, and complicated spastic paraplegia (SPG1): Clincal review with six additional families

    SciTech Connect

    Schrander-Stumpel, C.; Hoeweler, C.; Jones, M.

    1995-05-22

    X-linked hydrocephalus (HSAS) (MIM{sup *}307000), MASA syndrome (MIM {sup *}303350), and complicated spastic paraplegia (SPG1) (MIM {sup *}3129000) are closely related. Soon after delineation, SPG1 was incorporated into the spectrum of MASA syndrome. HSAS and MASA syndrome show great clinical overlap; DNA linkage analysis places the loci at Xq28. In an increasing number of families with MASA syndrome or HSAS, mutations in L1CAM, a gene located at Xq28, have been reported. In order to further delineate the clinical spectrum, we studied 6 families with male patients presenting with MASA syndrome, HSAS, or a mixed phenotype. We summarized data from previous reports and compared them with our data. Clinical variability appears to be great, even within families. Problems in genetic counseling and prenatal diagnosis, the possible overlap with X-linked corpus callosum agenesis and FG syndrome, and the different forms of X-linked complicated spastic paraplegia are discussed. Since adducted thumbs and spastic paraplegia are found in 90% of the patients, the condition may be present in males with nonspecific mental retardation. We propose to abandon the designation MASA syndrome and use the term HSAS/MASA spectrum, incorporating SPG1. 79 refs., 6 figs., 2 tabs.

  2. Sequential Addition Reaction of Sulfanylmethyllithiums and Grignard Reagents to Thioformamides Leading to the Formation of 2-Phenyl-2-sulfanylethyl Tertiary Amines.

    PubMed

    Murai, Toshiaki; Mutoh, Natsumi

    2016-09-16

    The reaction of sulfanylmethyllithiums generated from benzylsulfanes and n-BuLi with N,N-dimethylthioformamide followed by the addition of Grignard reagents gave 2-phenyl-2-sulfanyl tertiary amines in moderate to good yields. A range of Grignard reagents involving primary alkyl, aryl, vinyl, and alkynyl Grignard reagents were used. Two carbon-carbon bond-forming reactions were achieved through a one-pot reaction. The reaction showed good to high diastereoselectivity, particularly with alkynyl Grignard reagents. PMID:27565031

  3. DNA markers closely linked to nematode resistance genes in sugar beet (Beta vulgaris L.) mapped using chromosome additions and translocations originating from wild beets of the Procumbentes section.

    PubMed

    Jung, C; Koch, R; Fischer, F; Brandes, A; Wricke, G; Herrmann, R G

    1992-03-01

    Genes conferring resistance to the beet cyst nematode (Heterodera schachtii Schm.) have been transferred to sugar beet (Beta vulgaris L.) from three wild species of the Procumbentes section using monosomic addition and translocation lines, because no meiotic recombination occurs between chromosomes of cultured and wild species. In the course of a project to isolate the nematode resistance genes by strategies of reverse genetics, probes were cloned from DNA of a fragmented B. procumbens chromosome carrying a resistance gene, which had been isolated by pulsed-field gel electrophoresis. One probe (pRK643) hybridized with a short dispersed repetitive DNA element, which was found only in wild beets, and thus may be used as a molecular marker for nematode resistance to progeneis of monosomic addition lines segregating resistant and susceptible individuals. Additional probes for the resistance gene region were obtained with a polymerase chain reaction (PCR)-based strategy using repetitive primers to amplify DNA located between repetitive elements. One of these probes established the existence of at least six different chromosomes from wild beet species, each conferring resistance independently of the others. A strict correlation between the length of the wild beet chromatin introduced in fragment addition and translocation lines and the repeat copy number has been used physically to map the region conferring resistance to a chromosome segment of 0.5-3 Mb.

  4. Targeted Gene Addition to a Safe Harbor locus in human CD34+ Hematopoietic Stem Cells for Correction of X-linked Chronic Granulomatous Disease

    PubMed Central

    De Ravin, Suk See; Reik, Andreas; Liu, Pei-Qi; Li, Linhong; Wu, Xiaolin; Su, Ling; Raley, Castle; Theobald, Narda; Choi, Uimook; Song, Alexander H.; Chan, Andy; Pearl, Jocelynn R.; Paschon, David E.; Lee, Janet; Newcombe, Hannah; Koontz, Sherry; Sweeney, Colin; Shivak, David A.; Zarember, Kol A.; Peshwa, Madhusudan V.; Gregory, Philip D.; Urnov, Fyodor D.; Malech, Harry L.

    2016-01-01

    Gene therapy with genetically modified human CD34+ hematopoietic stem cells (HSCs) may be safer using targeted integration (TI) of transgenes into a genomic ‘safe harbor’ site than random viral integration. We demonstrate that temporally optimized delivery of zinc finger nuclease mRNA via electroporation and adeno associated virus (AAV) 6 delivery of donor constructs in human HSCs approaches clinically relevant levels of TI into the AAVS1 safe harbor locus. Up to 58% Venus-positive HSCs with 6–16% human cell marking were observed following engraftment into mice. In HSCs from patients with X-linked chronic granulomatous disease (X-CGD), caused by mutations in the gp91phox subunit of the NADPH oxidase, TI of a gp91phox transgene into AAVS1 in resulted in ~15% gp91phox expression and increased NADPH oxidase activity in ex vivo–derived neutrophils. In mice transplanted with corrected HSCs, 4–11% of human cells in the bone marrow expressed gp91phox. This method for TI into AAVS1 may be broadly applicable to correction of other monogenic diseases. PMID:26950749

  5. A high CO2 -driven decrease in plant transpiration leads to perturbations in the hydrological cycle and may link terrestrial and marine loss of biodiversity: deep-time evidence.

    NASA Astrophysics Data System (ADS)

    Steinthorsdottir, Margret; Woodward, F. Ian; Surlyk, Finn; McElwain, Jennifer C.

    2013-04-01

    CO2 is obtained and water vapor simultaneously transpired through plant stomata, driving the water uptake of roots. Stomata are key elements of the Earth's hydrological cycle, since a large part of the evapotranspiration from the surface to the atmosphere takes place via stomatal pores. Plants exercise stomatal control, by adjusting stomatal size and/or density in order to preserve water while maintaining carbon uptake for photosynthesis. A global decrease in stomatal density and/or size causes a decrease in transpiration and has the potential to increase global runoff. Here we show, from 91 fossil leaf cuticle specimens from the Triassic/Jurassic boundary transition (Tr-J) of East Greenland, that both stomatal size and density decreased dramatically during the Tr-J, coinciding with mass extinctions, major environmental upheaval and a negative C-isotope excursion. We estimate that these developmental and structural changes in stomata resulted in a 50-60% drop in stomatal and canopy transpiration as calibrated using a stomatal model, based on empirical measurements and adjusted for fossil plants. We additionally present new field evidence indicating a change to increased erosion and bad-land formation at the Tr-J. We hypothesize that plant physiological responses to high carbon dioxide concentrations at the Tr-J may have increased runoff at the local and perhaps even regional scale. Increased runoff may result in increased flux of nutrients from land to oceans, leading to eutrophication, anoxia and ultimately loss of marine biodiversity. High-CO2 driven changes in stomatal and canopy transpiration therefore provide a possible mechanistic link between terrestrial ecological crisis and marine mass extinction at the Tr-J.

  6. "Another Link in the Chain" Update: State Policies and Practices for Case Management and Environmental Investigation for Lead-Poisoned Children.

    ERIC Educational Resources Information Center

    McLaine, Pat; Gaitens, Joanna

    This report details a national survey, conducted in 2000, to document changes since 1998 in policies and practices for case management and environmental investigation for lead poisoned children; the study also investigated the impact of the previous national survey in precipitating change. Participating in the survey were program directors or…

  7. Amino acid addition to Vibrio cholerae LPS establishes a link between surface remodeling in Gram-positive and Gram-negative bacteria

    PubMed Central

    Hankins, Jessica V.; Madsen, James A.; Giles, David K.; Brodbelt, Jennifer S.; Trent, M. Stephen

    2012-01-01

    Historically, the O1 El Tor and classical biotypes of Vibrio cholerae have been differentiated by their resistance to the antimicrobial peptide polymyxin B. However, the molecular mechanisms associated with this phenotypic distinction have remained a mystery for 50 y. Both Gram-negative and Gram-positive bacteria modify their cell wall components with amine-containing substituents to reduce the net negative charge of the bacterial surface, thereby promoting cationic antimicrobial peptide resistance. In the present study, we demonstrate that V. cholerae modify the lipid A anchor of LPS with glycine and diglycine residues. This previously uncharacterized lipid A modification confers polymyxin resistance in V. cholerae El Tor, requiring three V. cholerae proteins: Vc1577 (AlmG), Vc1578 (AlmF), and Vc1579 (AlmE). Interestingly, the protein machinery required for glycine addition is reminiscent of the Gram-positive system responsible for d-alanylation of teichoic acids. Such machinery was not thought to be used by Gram-negative organisms. V. cholerae O1 El Tor mutants lacking genes involved in transferring glycine to LPS showed a 100-fold increase in sensitivity to polymyxin B. This work reveals a unique lipid A modification and demonstrates a charge-based remodeling strategy shared between Gram-positive and Gram-negative organisms. PMID:22589301

  8. An undetectable source of technical error that could lead to false negative results in enzyme linked immunosorbent assay of antibodies to HIV-1.

    PubMed

    Wiltbank, T B; McCarroll, D R; Wartick, M G

    1989-01-01

    Since the institution of routine testing for antibodies to Human Immunodeficiency Virus (HIV) using the enzyme-linked immunosorbent assay (ELISA), the specificity and sensitivity of this assay system has received significant scrutiny. During previous use of this methodology, we have quantified rates of false biological positive results using commercial kit assays in a normal donor population. In this study, we have identified a potential source for false negative results. Using multiple lots of two different commercial ELISA kits, the absorbance readings at the test end point could not differentiate between normal non-reactive donor samples and blanks containing no sample. These results occur using normal donor samples, even though the assays could distinguish between blank wells and the manufacturers' "normal controls", provided with the assay. Our findings suggest that a technical pipetting error is presently undetectable, either visually or by statistical methods, and could permit an untested, potentially HIV-1 positive, unit to be released into the transfusable blood supply. A possible solution is suggested.

  9. miR-199a Links MeCP2 with mTOR Signaling and Its Dysregulation Leads to Rett Syndrome Phenotypes.

    PubMed

    Tsujimura, Keita; Irie, Koichiro; Nakashima, Hideyuki; Egashira, Yoshihiro; Fukao, Yoichiro; Fujiwara, Masayuki; Itoh, Masayuki; Uesaka, Masahiro; Imamura, Takuya; Nakahata, Yasukazu; Yamashita, Yui; Abe, Takaya; Takamori, Shigeo; Nakashima, Kinichi

    2015-09-22

    Rett syndrome (RTT) is a neurodevelopmental disorder caused by MECP2 mutations. Although emerging evidence suggests that MeCP2 deficiency is associated with dysregulation of mechanistic target of rapamycin (mTOR), which functions as a hub for various signaling pathways, the mechanism underlying this association and the molecular pathophysiology of RTT remain elusive. We show here that MeCP2 promotes the posttranscriptional processing of particular microRNAs (miRNAs) as a component of the microprocessor Drosha complex. Among the MeCP2-regulated miRNAs, we found that miR-199a positively controls mTOR signaling by targeting inhibitors for mTOR signaling. miR-199a and its targets have opposite effects on mTOR activity, ameliorating and inducing RTT neuronal phenotypes, respectively. Furthermore, genetic deletion of miR-199a-2 led to a reduction of mTOR activity in the brain and recapitulated numerous RTT phenotypes in mice. Together, these findings establish miR-199a as a critical downstream target of MeCP2 in RTT pathogenesis by linking MeCP2 with mTOR signaling.

  10. Linking family economic pressure and supportive parenting to adolescent health behaviors: two developmental pathways leading to health promoting and health risk behaviors.

    PubMed

    Kwon, Josephine A; Wickrama, K A S

    2014-07-01

    Adolescent health behaviors, especially health risk behaviors, have previously been linked to distal (i.e., family economic pressure) and proximal (i.e., parental support) contributors. However, few studies have examined both types of contributors along with considering health promoting and health risk behaviors separately. The present study investigated the influences of family economic hardship, supportive parenting as conceptualized by self-determination theory, and individual psychosocial and behavioral characteristics (i.e., mastery and delinquency, respectively) on adolescents' health promoting and health risk behaviors. We used structural equation modeling to analyze longitudinal data from a sample of Caucasian adolescent children and their mothers and fathers (N = 407, 54 % female) to examine direct and indirect effects, as well as gender symmetry and asymmetry. Findings suggest that family economic pressure contributed to adolescent mastery and delinquency through supportive parenting. Further, supportive parenting indirectly affected adolescent health risk behaviors only through delinquency, whereas supportive parenting indirectly influenced health promoting behaviors only through mastery, suggesting different developmental pathways for adolescent health risk and health promoting behaviors. Testing for gender symmetry of the full model showed that maternal and paternal parenting contributed to females' health risk behaviors directly, while maternal and paternal parenting contributed to males' health risk behaviors through delinquency. Gender symmetry was largely unsupported. The study highlights key direct and indirect pathways to adolescent health risk and health promoting behaviors within a family stress model and self-determination theory framework, and also highlights important gender differences in these developmental pathways.

  11. Linking large piezoelectric coefficients to highly flexible polarization of lead free BaTiO3-CaTiO3-BaZrO3 ceramics

    NASA Astrophysics Data System (ADS)

    Benabdallah, F.; Simon, A.; Khemakhem, H.; Elissalde, C.; Maglione, M.

    2011-06-01

    We report a large d31 piezoelectric coefficient and corresponding electromechanical coupling factor, Kp, of 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BCTZ50) and 0.68Ba(Zr0.2Ti0.8)O3-0.32(Ba0.7Ca0.3)TiO3 (BCTZ32) lead-free piezoceramics. The piezoelectric coefficient, d31, reaches a high value of 200 pC/N for BCTZ50 at room temperature which is comparable to the one of the soft PZT. This confirms the previously reported d33 for the same material. A useful way to achieve such performances at the expense of a smaller thermal budget is suggested, enabling better control of the ceramics composition and microstructure. Based on pyroelectric and ferroelectric hysteresis loops measurements, we show that such outstanding properties are likely due to the high flexibility of polarization under thermal and electric stresses.

  12. Potlining Additives

    SciTech Connect

    Rudolf Keller

    2004-08-10

    In this project, a concept to improve the performance of aluminum production cells by introducing potlining additives was examined and tested. Boron oxide was added to cathode blocks, and titanium was dissolved in the metal pool; this resulted in the formation of titanium diboride and caused the molten aluminum to wet the carbonaceous cathode surface. Such wetting reportedly leads to operational improvements and extended cell life. In addition, boron oxide suppresses cyanide formation. This final report presents and discusses the results of this project. Substantial economic benefits for the practical implementation of the technology are projected, especially for modern cells with graphitized blocks. For example, with an energy savings of about 5% and an increase in pot life from 1500 to 2500 days, a cost savings of $ 0.023 per pound of aluminum produced is projected for a 200 kA pot.

  13. Theoretical effect of modifications to the upper surface of two NACA airfoils using smooth polynomial additional thickness distributions which emphasize leading edge profile and which vary quadratically at the trailing edge. [using flow equations and a CDC 7600 computer

    NASA Technical Reports Server (NTRS)

    Merz, A. W.; Hague, D. S.

    1975-01-01

    An investigation was conducted on a CDC 7600 digital computer to determine the effects of additional thickness distributions to the upper surface of the NACA 64-206 and 64 sub 1 - 212 airfoils. The additional thickness distribution had the form of a continuous mathematical function which disappears at both the leading edge and the trailing edge. The function behaves as a polynomial of order epsilon sub 1 at the leading edge, and a polynomial of order epsilon sub 2 at the trailing edge. Epsilon sub 2 is a constant and epsilon sub 1 is varied over a range of practical interest. The magnitude of the additional thickness, y, is a second input parameter, and the effect of varying epsilon sub 1 and y on the aerodynamic performance of the airfoil was investigated. Results were obtained at a Mach number of 0.2 with an angle-of-attack of 6 degrees on the basic airfoils, and all calculations employ the full potential flow equations for two dimensional flow. The relaxation method of Jameson was employed for solution of the potential flow equations.

  14. LEADING WITH LEADING INDICATORS

    SciTech Connect

    PREVETTE, S.S.

    2005-01-27

    This paper documents Fluor Hanford's use of Leading Indicators, management leadership, and statistical methodology in order to improve safe performance of work. By applying these methods, Fluor Hanford achieved a significant reduction in injury rates in 2003 and 2004, and the improvement continues today. The integration of data, leadership, and teamwork pays off with improved safety performance and credibility with the customer. The use of Statistical Process Control, Pareto Charts, and Systems Thinking and their effect on management decisions and employee involvement are discussed. Included are practical examples of choosing leading indicators. A statistically based color coded dashboard presentation system methodology is provided. These tools, management theories and methods, coupled with involved leadership and employee efforts, directly led to significant improvements in worker safety and health, and environmental protection and restoration at one of the nation's largest nuclear cleanup sites.

  15. The link in Linking

    PubMed Central

    Caldwell, Jane C; Chiale, Pablo A; Gonzalez, Mario D; Baranchuk, Adrian

    2013-01-01

    We present 2 cases of the slow-fast form of AVNRT with initially narrow QRS complexes followed by sudden unexpected transition to persistently wide QRS complexes due to aberrant intraventricular conduction. Introduction of a properly timed extrastimulus in one case and critical oscillations in cycle length due to short-long coupling in the second case set the stage for the initial bundle branch block. However, persistence of the aberrancy pattern once the initial event abated was maintained by the "linking" phenomenon. Delayed, retrograde concealed activation from the contralateral bundle branch perpetuated the initial bundle branch block. PMID:23840106

  16. Lead Poisoning

    MedlinePlus

    ... Experiments Stories Lessons Topics Games Activities Lessons MENU Lead Poisoning Kids Homepage Topics Pollution Lead Poisoning What is ... you can avoid contact with it! Sources of Lead Poisoning HOUSE PAINTS: Before1950, lead-based paint was used ...

  17. Lead Test

    MedlinePlus

    ... to determine lead sources, educating family members about lead poisoning , and instituting follow-up testing to monitor the ... high levels of lead, see the article on Lead Poisoning . The Occupational Safety and Health Administration (OSHA) has ...

  18. Lead Poisoning

    MedlinePlus

    Lead Poisoning What is it and who is affected? Lead is a highly toxic substance, exposure to which ... and children can suffer from the effects of lead poisoning, but childhood lead poisoning is much more frequent. ...

  19. Murine elongation factor 1 alpha (EF-1 alpha) is posttranslationally modified by novel amide-linked ethanolamine-phosphoglycerol moieties. Addition of ethanolamine-phosphoglycerol to specific glutamic acid residues on EF-1 alpha

    SciTech Connect

    Whiteheart, S.W.; Shenbagamurthi, P.; Chen, L.; Cotter, R.J.; Hart, G.W. )

    1989-08-25

    Elongation Factor 1 alpha (EF-1 alpha), an important eukaryotic translation factor, transports charged aminoacyl-tRNA from the cytosol to the ribosomes during poly-peptide synthesis. Metabolic radiolabeling with ({sup 3}H) ethanolamine shows that, in all cells examined, EF-1 alpha is the major radiolabeled protein. Radiolabeled EF-1 alpha has an apparent Mr = 53,000 and a basic isoelectric point. It is cytosolic and does not contain N-linked oligosaccharides. Trypsin digestion of murine EF-1 alpha generated two major ({sup 3}H)ethanolamine-labeled peptides. Three peptides were sequenced and were identical to two distinct regions of the human EF-1 alpha protein. Blank sequencing cycles coinciding with glutamic acid in the human cDNA-derived sequence were also found to release ({sup 3}H)ethanolamine, and compositional analysis of these peptides confirmed the presence of glutamic acid. Dansylation analysis demonstrates that the amine group of the ethanolamine is blocked. These results indicate that EF-1 alpha is posttranslationally modified by the covalent attachment of ethanolamine via an amide bond to at least two specific glutamic acid residues (Glu-301 and Glu-374). The hydroxyl group of the attached ethanolamine was shown by mass spectrometry and compositional analysis, to be further modified by the addition of a phosphoglycerol unit. This novel posttranslational modification may represent an important alteration of EF-1 alpha, comparable to the regulatory effects of posttranslational methylation of EF-1 alpha lysine residues.

  20. Down-regulation of osmotin (PR5) gene by virus-induced gene silencing (VIGS) leads to susceptibility of resistant Piper colubrinum Link. to the oomycete pathogen Phytophthora capsici Leonian.

    PubMed

    Anu, K; Jessymol, K K; Chidambareswaren, M; Gayathri, G S; Manjula, S

    2015-06-01

    Piper colubrinum Link., a distant relative of Piper nigrum L., is immune to the oomycete pathogen Phytophthora capsici Leonian that causes 'quick wilt' in cultivated black pepper (P. nigrum). The osmotin, PR5 gene homologue, earlier identified from P. colubrinum, showed significant overexpression in response to pathogen and defense signalling molecules. The present study focuses on the functional validation of P. colubrinum osmotin (PcOSM) by virus induced gene silencing (VIGS) using Tobacco Rattle Virus (TRV)-based vector. P. colubrinum plants maintained under controlled growth conditions in a growth chamber were infiltrated with Agrobacterium carrying TRV empty vector (control) and TRV vector carrying PcOSM. Three weeks post infiltration, viral movement was confirmed in newly emerged leaves of infiltrated plants by RT-PCR using TRV RNA1 and TRV RNA2 primers. Semi-quantitative RT-PCR confirmed significant down-regulation of PcOSM gene in TRV-PcOSM infiltrated plant compared with the control plants. The control and silenced plants were challenged with Phytophthora capsici which demonstrated that knock-down of PcOSM in P. colubrinum leads to increased fungal mycelial growth in silenced plants compared to control plants, which was accompanied by decreased accumulation of H2O2 as indicated by 3,3'-diaminobenzidine (DAB) staining. Thus, in this study, we demonstrated that Piper colubrinum osmotin gene is required for resisting P. capsici infection and has possible role in hypersensitive cell death response and oxidative burst signaling during infection. PMID:26155671

  1. Down-regulation of osmotin (PR5) gene by virus-induced gene silencing (VIGS) leads to susceptibility of resistant Piper colubrinum Link. to the oomycete pathogen Phytophthora capsici Leonian.

    PubMed

    Anu, K; Jessymol, K K; Chidambareswaren, M; Gayathri, G S; Manjula, S

    2015-06-01

    Piper colubrinum Link., a distant relative of Piper nigrum L., is immune to the oomycete pathogen Phytophthora capsici Leonian that causes 'quick wilt' in cultivated black pepper (P. nigrum). The osmotin, PR5 gene homologue, earlier identified from P. colubrinum, showed significant overexpression in response to pathogen and defense signalling molecules. The present study focuses on the functional validation of P. colubrinum osmotin (PcOSM) by virus induced gene silencing (VIGS) using Tobacco Rattle Virus (TRV)-based vector. P. colubrinum plants maintained under controlled growth conditions in a growth chamber were infiltrated with Agrobacterium carrying TRV empty vector (control) and TRV vector carrying PcOSM. Three weeks post infiltration, viral movement was confirmed in newly emerged leaves of infiltrated plants by RT-PCR using TRV RNA1 and TRV RNA2 primers. Semi-quantitative RT-PCR confirmed significant down-regulation of PcOSM gene in TRV-PcOSM infiltrated plant compared with the control plants. The control and silenced plants were challenged with Phytophthora capsici which demonstrated that knock-down of PcOSM in P. colubrinum leads to increased fungal mycelial growth in silenced plants compared to control plants, which was accompanied by decreased accumulation of H2O2 as indicated by 3,3'-diaminobenzidine (DAB) staining. Thus, in this study, we demonstrated that Piper colubrinum osmotin gene is required for resisting P. capsici infection and has possible role in hypersensitive cell death response and oxidative burst signaling during infection.

  2. Lead transformation to pyromorphite by fungi.

    PubMed

    Rhee, Young Joon; Hillier, Stephen; Gadd, Geoffrey Michael

    2012-02-01

    Lead (Pb) is a serious environmental pollutant in all its chemical forms [1]. Attempts have been made to immobilize lead in soil as the mineral pyromorphite using phosphate amendments (e.g., rock phosphate, phosphoric acid, and apatite [2-5]), although our work has demonstrated that soil fungi are able to transform pyromorphite into lead oxalate [6, 7]. Lead metal, an important structural and industrial material, is subject to weathering, and soil contamination also occurs through hunting and shooting [8, 9]. Although fungi are increasingly appreciated as geologic agents [10-12], there is a distinct lack of knowledge about their involvement in lead geochemistry. We examined the influence of fungal activity on lead metal and discovered that metallic lead can be transformed into chloropyromorphite, the most stable lead mineral that exists. This is of geochemical significance, not only regarding lead fate and cycling in the environment but also in relation to the phosphate cycle and linked with microbial transformations of inorganic and organic phosphorus. This paper provides the first report of mycogenic chloropyromorphite formation from metallic lead and highlights the significance of this phenomenon as a biotic component of lead biogeochemistry, with additional consequences for microbial survival in lead-contaminated environments and bioremedial treatments for Pb-contaminated land.

  3. Lead Toxicity

    MedlinePlus

    ... homes. • Most people, especially children, who suffer from lead poisoning are exposed through lead-contaminated household dust or ... and six if they are at risk of lead poisoning (see: ). Who can I call to get more ...

  4. Lead Exposure Reduction Act of 1992. Report together with Additional and Dissenting Views To Accompany 5730 (Including Cost Estimate of the Congressional Budget Office.) Part 1 [and] Part 2. House of Representatives, 102d Congress, 2d Session.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on Energy and Commerce.

    This two-part report deals with the Lead Exposure Reduction Act of 1992 (H.R. 5730), an amendment to the Toxic Substances Control Act and the Federal Food, Drug, and Cosmetic Act. The amendment is intended to lead to the reduction of levels of lead in the environment and to lower the degree of childhood exposure to lead. The bill provides for a…

  5. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  6. Lead Poisoning

    MedlinePlus

    ... can be found in all parts of our environment. Much of it comes from human activities such as mining and manufacturing. Lead used to be in paint; older houses may still have lead paint. You could be exposed to lead by Eating food or drinking water that contains lead. Water pipes in older homes ...

  7. Lead poisoning

    SciTech Connect

    Rekus, J.F.

    1992-08-01

    Construction workers who weld, cut or blast structural steel coated with lead-based paint are at significant risk of lead poisoning. Although technology to control these exposures may not have existed when the lead standard was promulgated, it is available today. Employers who do not take steps to protect their employees from lead exposure may be cited and fined severely for their failure.

  8. Law: toxic lead aftermath

    SciTech Connect

    Goldstein, E.A.

    1983-03-01

    The paper describes the events which began with an EPA proposal to weaken the lead-in-gas regulations. Because of the outcry from environmentalists and expert testimony from the medical community, the EPA reversed its policy and issued new standards which would reduce lead emissions between 1983 and 1990 by 34 percent (128,000 tons). Scientific evidence presented showed a clear reduction in blood lead levels from 1976-1980 which paralleled decreases of lead in gasoline. Results from lead poisoning clinics which linked chronic low lead exposures to decreased classroom performance and other learning disabilities were presented. Lawyers from several environmental groups took the agency to court on the related issue of attaining national ambient air quality standards for lead. (JMT)

  9. Cross-linking reconsidered: binding and cross-linking fields and the cellular response.

    PubMed Central

    Sulzer, B; De Boer, R J; Perelson, A S

    1996-01-01

    We analyze a model for the reversible cross-linking of cell surface receptors by a collection of bivalent ligands with different affinities for the receptor as would be found in a polyclonal anti-receptor serum. We assume that the amount of cross-linking determines, via a monotonic function, the rate at which cells become activated and divide. In addition to the density of receptors on the cell surface, two quantities, the binding field and the cross-linking field, are needed to characterize the cross-linking curve, i.e., the equilibrium concentration of cross-linked receptors plotted as a function of the total ligand site concentration. The binding field is the sum of all ligand site concentrations weighted by their respective binding affinities, and the cross-linking field is the sum of all ligand site concentrations weighted by the product of their respective binding and cross-linking affinity and the total receptor density. Assuming that the cross-linking affinity decreases if the binding affinity decreases, we find that the height of the cross-linking curve decreases, its width narrows, and its center shifts to higher ligand site concentrations as the affinities decrease. Moreover, when we consider cross-linking-induced proliferation, we find that there is a minimum cross-linking affinity that must be surpassed before a clone can expand. We also show that under many circumstances a polyclonal antiserum would be more likely than a monoclonal antibody to lead to cross-linking-induced proliferation. Images FIGURE 1 FIGURE 2 FIGURE 5 PMID:8785275

  10. Lead poisoning.

    PubMed Central

    Landrigan, P J; Todd, A C

    1994-01-01

    Lead poisoning is the most common disease of environmental origin in the United States today. Adult lead poisoning results primarily from exposure by inhalation in the workplace. Pediatric lead poisoning results principally from the ingestion of lead from environmental media, including paint chips, dust, soil, drinking water, ceramics, and medications. Lead is toxic to many organ systems, among them developing erythrocytes, the kidneys, and the nervous system. Lead-induced toxicity to the central nervous system causes delayed development, diminished intelligence, and altered behavior. In young children, this effect has been demonstrated convincingly to occur at blood lead levels between 10 and 20 micrograms per dl. The Centers for Disease Control and Prevention has recommended that a blood lead level of 10 micrograms per dl or higher be considered evidence of increased lead absorption, and the National Academy of Sciences has concurred in that recommendation. Unresolved issues in need of further study include the frequency of screening young children for lead, the question of whether women should be offered screening for lead before conceiving a pregnancy, the role of x-ray fluorescence analysis in assessing lead in bone, and the appropriate legislative response of the United States government to lead-based paint abatement. PMID:7941534

  11. Lead poisoning

    MedlinePlus

    ... lead is still found in some modern faucets. Soil contaminated by decades of car exhaust or years ... house paint scrapings. Lead is more common in soil near highways and houses. Hobbies involving soldering, stained ...

  12. University-linked localities

    PubMed Central

    Spicer, John; Gnani, Shamini

    2012-01-01

    In this article, we propose that reframing the old concept of ‘academic general practices’ as ‘university-linked localities’ will help to integrate the work of those leading commissioning, education, research and public health. It will provide a ‘playground’ for different disciplines to creatively interact for the benefit of all. PMID:26265944

  13. Community Links

    ERIC Educational Resources Information Center

    Nelson, Mary

    1975-01-01

    At Moraine Valley Community College (Illinois), a chain of events, programs, activities, and services has linked the college and community in such areas as fine arts, ethnic groups, public services, community action, community service, and community education. (Author/NHM)

  14. Link Analysis

    NASA Astrophysics Data System (ADS)

    Donoho, Steve

    Link analysis is a collection of techniques that operate on data that can be represented as nodes and links. This chapter surveys a variety of techniques including subgraph matching, finding cliques and K-plexes, maximizing spread of influence, visualization, finding hubs and authorities, and combining with traditional techniques (classification, clustering, etc). It also surveys applications including social network analysis, viral marketing, Internet search, fraud detection, and crime prevention.

  15. Phosphazene additives

    DOEpatents

    Harrup, Mason K; Rollins, Harry W

    2013-11-26

    An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

  16. Leading Democratically

    ERIC Educational Resources Information Center

    Brookfield, Stephen

    2010-01-01

    Democracy is the most venerated of American ideas, the one for which wars are fought and people die. So most people would probably agree that leaders should be able to lead well in a democratic society. Yet, genuinely democratic leadership is a relative rarity. Leading democratically means viewing leadership as a function or process, rather than…

  17. Parasites dominate food web links.

    PubMed

    Lafferty, Kevin D; Dobson, Andrew P; Kuris, Armand M

    2006-07-25

    Parasitism is the most common animal lifestyle, yet food webs rarely include parasites. The few earlier studies have indicated that including parasites leads to obvious increases in species richness, number of links, and food chain length. A less obvious result was that adding parasites slightly reduced connectance, a key metric considered to affect food web stability. However, reported reductions in connectance after the addition of parasites resulted from an inappropriate calculation. Two alternative corrective approaches applied to four published studies yield an opposite result: parasites increase connectance, sometimes dramatically. In addition, we find that parasites can greatly affect other food web statistics, such as nestedness (asymmetry of interactions), chain length, and linkage density. Furthermore, whereas most food webs find that top trophic levels are least vulnerable to natural enemies, the inclusion of parasites revealed that mid-trophic levels, not low trophic levels, suffered the highest vulnerability to natural enemies. These results show that food webs are very incomplete without parasites. Most notably, recognition of parasite links may have important consequences for ecosystem stability because they can increase connectance and nestedness.

  18. LEAD STUDIES

    PubMed Central

    Aub, Joseph C.; Reznikoff, Paul; Smith, Dorothea E.

    1924-01-01

    It appears, from the investigations in other laboratories, that the anemia observed in cases of lead poisoning is due to destruction of blood rather than to diminished production of blood. The method of poisoning cells in vitro with lead was adopted in order to study this phenomenon, and distinct effects were thereby obtained, even when only 0.001 mg. of lead is added to approximately 5 billion washed red corpuscles. In order to obtain optimum results the usual dosage employed was ten times this or 0.01 mg. per 5 billion cells. The following changes were observed in cells so treated. 1. Such a marked increase in the resistance to hypotonic salt solution develops that complete hemolysis does not occur until the cells are exposed to a saline solution of 0.05 per cent. Untreated cells are completely hemolyzed in 0.25 or 0.225 per cent saline. 2. This reaction is quantitative and varies with the concentration of lead used. Under the conditions of our experiments this phenomenon seems to be unique. The effects of arsenic are very slight in comparison. 3. While from this reaction it may be concluded that lead increases cellular resistance, it also appears that it shortens the life of blood cells. This may be demonstrated by the much more rapid appearance of hemolysis than normal when the cells are merely allowed to stand in Ringer solution of any dilution. 4. In rabbits with acute lead poisoning these same phenomena may be noted in vivo. 5. Both phenomena may be changed in vitro by varying the time and temperature of the reaction and the concentration of lead, as Fici has already pointed out. 6. If normal cells stand in Ringer solution for 6 hours something diffuses into the solution which largely reduces the action of lead. After repeated washing these cells react with lead in the usual manner. 7. Small amounts of serum react with lead and eliminate its effects. Red blood cells, treated with a mixture of lead and blood serum, show normal hemolysis in hypotonic salt

  19. Micro-x-ray fluorescence, micro-x-ray absorption spectroscopy, and micro-x-ray diffraction investigation of lead speciation after the addition of different phosphorus amendments to a smelter-contaminated soil.

    PubMed

    Baker, Lucas R; Pierzynski, Gary M; Hettiarachchi, Ganga M; Scheckel, Kirk G; Newville, Matthew

    2014-03-01

    The stabilization of Pb on additions of P to contaminated soils and mine spoil materials has been well documented. It is clear from the literature that different P sources result in different efficacies of Pb stabilization in the same contaminated material. We hypothesized that the differences in the efficacy of Pb stabilization in contaminated soils on fluid or granular P amendment addition is due to different P reaction processes in and around fertilizer granules and fluid droplets. We used a combination of several synchrotron-based techniques (i.e., spatially resolved micro-X-ray fluorescence, micro-X-ray absorption near-edge structure spectroscopy, and micro-X-ray diffraction) to speciate Pb at two incubation times in a smelter-contaminated soil on addition of several fluid and granular P amendments. The results indicated that the Pb phosphate mineral plumbogummite was an intermediate phase of pyromorphite formation. Additionally, all fluid and granular P sources were able to induce Pb phosphate formation, but fluid phosphoric acid (PA) was the most effective with time and distance from the treatment. Granular phosphate rock and triple super phosphate (TSP) amendments reacted to generate Pb phosphate minerals, with TSP being more effective at greater distances from the point of application. As a result, PA and TSP were the most effective P amendments at inducing Pb phosphate formation, but caution needs to be exercised when adding large amounts of soluble P to the environment.

  20. Micro-X-Ray Fluorescence, Micro-X-Ray Absorption Spectroscopy, and Micro-X-Ray Diffraction Investigation of Lead Speciation after the Addition of Different Phosphorus Amendments to a Smelter-Contaminated Soil

    EPA Science Inventory

    The stabilization of Pb on additions of P to contaminated soils and mine spoil materials has been well documented. It is clear from the literature that different P sources result in different efficacies of Pb stabilization in the same contaminated material. We hypothesized that...

  1. Ecotoxicology: Lead

    USGS Publications Warehouse

    Scheuhammer, A.M.; Beyer, W.N.; Schmitt, C.J.; Jorgensen, Sven Erik; Fath, Brian D.

    2008-01-01

    Lead (Pb) is a naturally occurring metallic element; trace concentrations are found in all environmental media and in all living things. However, certain human activities, especially base metal mining and smelting; combustion of leaded gasoline; the use of Pb in hunting, target shooting, and recreational angling; the use of Pb-based paints; and the uncontrolled disposal of Pb-containing products such as old vehicle batteries and electronic devices have resulted in increased environmental levels of Pb, and have created risks for Pb exposure and toxicity in invertebrates, fish, and wildlife in some ecosystems.

  2. Mixtures with relatives and linked markers.

    PubMed

    Dørum, Guro; Kling, Daniel; Tillmar, Andreas; Vigeland, Magnus Dehli; Egeland, Thore

    2016-05-01

    Mixture DNA profiles commonly appear in forensic genetics, and a large number of statistical methods and software are available for such cases. However, most of the literature concerns mixtures where the contributors are assumed unrelated and the genetic markers are unlinked. In this paper, we consider mixtures of linked markers and related contributors. If no relationships are involved, linkage can be ignored. While unlinked markers can be treated independently, linkage introduces dependencies. The use of linked markers presents statistical and computational challenges, but may also lead to a considerable increase in power since the number of markers available is much larger if we do not require the markers to be unlinked. In addition, some cases that cannot be solved with an unlimited number of unlinked autosomal markers can be solved with linked markers. We focus on two special cases of linked markers: pairs of linked autosomal markers and X-chromosomal markers. A framework is presented for calculation of likelihood ratios for mixtures with general relationships and with linkage between any number of markers. Finally, we explore the effect of linkage disequilibrium, also called allelic association, on the likelihood ratio.

  3. Tetraethyl lead

    Integrated Risk Information System (IRIS)

    Tetraethyl lead ; CASRN 78 - 00 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  4. [Leptin: a link between obesity and osteoarthritis?].

    PubMed

    Terlain, Bernard; Presle, Nathalie; Pottie, Pascale; Mainard, Didier; Netter, Patrick

    2006-10-01

    In addition to aging, obesity is one of the most common underlying causes of osteoarthritis (OA). Mechanical loading, together with biochemical and systemic factors linked to altered lipid metabolism, are thought to contribute to the onset of OA. It has been suggested that OA is a systemic metabolic disease associated with lipid disorders affecting joint homeostasis. These gradual changes may be due to the local effect of adipokines, and especially leptin. Indeed, their relative levels in joints differ from that found in plasma. In particular, leptin levels are increased and adiponectin and resistin levels are reduced This hypothesis is supported by--leptin overexpression in OA cartilage and its correlation with the degree of cartilage destruction,--abundant leptin synthesis by osteophytes, and--the high leptin levels found in OA joints from female patients. This link between OA and adipokines provides new leads regarding the prevention of OA and the identification of new drug targets.

  5. Lead uptake, toxicity, and detoxification in plants.

    PubMed

    Pourrut, Bertrand; Shahid, Muhammad; Dumat, Camille; Winterton, Peter; Pinelli, Eric

    2011-01-01

    Lead has gained considerable attention as a persistent toxic pollutant of concern,partly because it has been prominent in the debate concerning the growing anthropogenic pressure on the environment. The purpose of this review is to describe how plants take lead up and to link such uptake to the ecotoxicity of lead in plants.Moreover, we address the mechanisms by which plants or plant systems detoxify lead.Lead has many interesting physico-chemical properties that make it a very useful heavy metal. Indeed, lead has been used by people since the dawn of civilization.Industrialization, urbanization, mining, and many other anthropogenic activities have resulted in the redistribution of lead from the earth's crust to the soil and to the environment.Lead forms various complexes with soil components, and only a small fraction of the lead present as these complexes in the soil solution are phyto available. Despite its lack of essential function in plants, lead is absorbed by them mainly through the roots from soil solution and thereby may enter the food chain. The absorption of lead by roots occurs via the apoplastic pathway or via Ca2+-permeable channels.The behavior of lead in soil, and uptake by plants, is controlled by its speciation and by the soil pH, soil particle size, cation-exchange capacity, root surface area,root exudation, and degree of mycorrhizal transpiration. After uptake, lead primarily accumulates in root cells, because of the blockage by Casparian strips within the endodermis. Lead is also trapped by the negative charges that exist on roots' cell walls.Excessive lead accumulation in plant tissue impairs various morphological, physiological, and biochemical functions in plants, either directly or indirectly, and induces a range of deleterious effects. It causes phytotoxicity by changing cell membrane permeability, by reacting with active groups of different enzymes involved in plant metabolism and by reacting with the phosphate groups of ADP or ATP

  6. Cardiovascular actions of lead and relationship to hypertension: a review

    SciTech Connect

    Kopp, S.J.; Barron, J.T.; Tow, J.P.

    1988-06-01

    Chronic and acute lead poisoning cause overt, clinical symptoms of cardiac and vascular damage with potentially lethal consequences. Morphological, biochemical, and functional derangements of the heart have all been described in patients following exposure to excessive lead levels. Disturbances in cardiac electrical and mechanical activity and postmortem evidence of morphological and biochemical derangements of the myocardium have all been reported following excessive exposure to lead in humans. In addition, signs of vascular degeneration, abnormal vascular smooth muscle function, and altered vessel compliance have been described in humans chronically and acutely exposed to toxic lead levels. Similar cardiovascular complications have been detected following excessive lead exposure in experimental animals. Myocarditis, electrocardiographic disturbances, heightened catecholamine arrhythmogenicity, altered myocardial contractile responsiveness to inotropic stimulation, degenerative structural biochemical changes affecting the musculature of the heart and vasculature, hypertension, hypercholesterolemia, atherosclerosis, and increased vascular reactivity to ..cap alpha..-adrenergic agonists have been among the reported cardiovascular disturbances linked to lead poisoning. Although controversial, chronic low-level lead exposure has been linked to hypertension and other cardiovascular disturbances in both clinical and experimental studies. In general, it can be concluded that lead over a wide range of exposure intensities can induce significant changes in the function of the cardiovascular system.

  7. How does lead induce male infertility?

    PubMed Central

    Vigeh, Mohsen; Smith, Derek R.; Hsu, Ping-Chi

    2011-01-01

    An important part of male infertility of unknown etiology may be attributed to various environmental and occupational exposures to toxic substances, such as lead. The reproductive effects of lead are complex and appear to involve multiple pathways, not all of which are fully understood. It is still unclear, for example, if male reproductive issues in lead-exposed persons are mostly related to the disruption of reproductive hormones, whether the problems are due to the lead’s direct effects on the gonads, or both? This question has been difficult to answer, because lead, especially at high levels, may adversely affect many human organs. Although lead can potentially reduce male fertility by decreasing sperm count and motility, inducing abnormal morphology and affecting functional parameters; not all studies have been able to clearly demonstrate such findings. In addition, research has shown that the blood-testis barrier can protect testicular cells from direct exposure to high levels of blood lead. For these reasons and considering the wide spectrum of lead toxicity on reproductive hormones, the present review suggests that lead’s main influence on male reproduction probably occurs by altering the reproductive hormonal axis and the hormonal control on spermatogenesis, rather than by a direct toxic effect on the seminiferous tubules of the testes. As blood lead concentrations below the currently accepted worker protection standard may still adversely affect male fertility, future studies should aim to establish more concrete links between lead exposure (especially at low levels) and subsequent male infertility. Research should also pay more attention to lead’s effects on reducing male fertility rates based on not only hormonal axis alteration, but also on the changes in sperm characteristic among exposed subjects. PMID:25356074

  8. Helically linked mirror arrangement

    SciTech Connect

    Ranjan, P.

    1986-08-01

    A scheme is described for helical linking of mirror sections, which endeavors to combine the better features of toroidal and mirror devices by eliminating the longitudinal loss of mirror machines, having moderately high average ..beta.. and steady state operation. This scheme is aimed at a device, with closed magnetic surfaces having rotational transform for equilibrium, one or more axisymmetric straight sections for reduced radial loss, a simple geometrical axis for the links and an overall positive magnetic well depth for stability. We start by describing several other attempts at linking of mirror sections, made both in the past and the present. Then a description of our helically linked mirror scheme is given. This example has three identical straight sections connected by three sections having helical geometric axes. A theoretical analysis of the magnetic field and single-particle orbits in them leads to the conclusion that most of the passing particles would be confined in the device and they would have orbits independent of pitch angle under certain conditions. Numerical results are presented, which agree well with the theoretical results as far as passing particle orbits are concerned.

  9. Disruption of neurofilament network with aggregation of light neurofilament protein: a common pathway leading to motor neuron degeneration due to Charcot-Marie-Tooth disease-linked mutations in NFL and HSPB1.

    PubMed

    Zhai, Jinbin; Lin, Hong; Julien, Jean-Pierre; Schlaepfer, William W

    2007-12-15

    Mutations in neurofilament light (NFL) subunit and small heat-shock protein B1 (HSPB1) cause autosomal-dominant axonal Charcot-Marie-Tooth disease type 2E (CMT2E) and type 2F (CMT2F). Previous studies have shown that CMT mutations in NFL and HSPB1 disrupt NF assembly and cause aggregation of NFL protein. In this study, we investigate the role of aggregation of NFL protein in the neurotoxicity of CMT mutant NFL and CMT mutant HSPB1 in motor neurons. We find that expression of CMT mutant NFL leads to progressive degeneration and loss of neuronal viability of cultured motor neurons. Degenerating motor neurons show fragmentation and loss of neuritic processes associated with disruption of NF network and aggregation of NFL protein. Co-expression of wild-type HSPB1 diminishes aggregation of CMT mutant NFL, induces reversal of CMT mutant NFL aggregates and reduces CMT mutant NFL-induced loss of motor neuron viability. Like CMT mutant NFL, expression of S135F CMT mutant HSPB1 also leads to progressive degeneration of motor neurons with disruption of NF network and aggregation of NFL protein. Further studies show that wild-type and S135F mutant HSPB1 associate with wild-type and CMT mutant NFL and that S135F mutant HSPB1 has dominant effect on disruption of NF assembly and aggregation of NFL protein. Finally, we show that deletion of NFL markedly reduces degeneration and loss of motor neuron viability induced by S135F mutant HSPB1. Together, our data support the view that disruption of NF network with aggregation of NFL is a common triggering event of motor neuron degeneration in CMT2E and CMT2F disease.

  10. 21 CFR 73.2396 - Lead acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Lead acetate. 73.2396 Section 73.2396 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2396 Lead acetate. (a) Identity. The color additive lead acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula...

  11. 21 CFR 73.2396 - Lead acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Lead acetate. 73.2396 Section 73.2396 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2396 Lead acetate. (a) Identity. The color additive lead acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula...

  12. 21 CFR 73.2396 - Lead acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Lead acetate. 73.2396 Section 73.2396 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2396 Lead acetate. (a) Identity. The color additive lead acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula...

  13. 21 CFR 73.2396 - Lead acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Lead acetate. 73.2396 Section 73.2396 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2396 Lead acetate. (a) Identity. The color additive lead acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula...

  14. 21 CFR 73.2396 - Lead acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Lead acetate. 73.2396 Section 73.2396 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2396 Lead acetate. (a) Identity. The color additive lead acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula...

  15. CAN FLUORIDATION AFFECT WATER LEAD LEVELS AND LEAD NEUROTOXICITY?

    EPA Science Inventory

    Recent reports have attempted to show that certain approaches to fluoridating potable water is linked to increased levels of lead(II) in the blood. We examine these claims in light of the established science and critically evaluate their significance. The completeness of nexafluo...

  16. Early childhood lead exposure and exceptionality designations for students

    PubMed Central

    Miranda, Marie Lynn; Maxson, Pamela; Kim, Dohyeong

    2009-01-01

    The achievement gap continues to be an important educational issue, with disadvantaged groups exhibiting poorer school performance. Recently, literature has shown that even very low levels of early lead exposure affect cognitive and academic performance. As individuals at the lower end of the socioeconomic spectrum are more likely to be exposed to lead, this exposure may be an important contributor to the achievement gap. In this paper, we explore whether early childhood blood lead levels are associated with membership in exceptionality designation groups. In addition, we examine the racial and socioeconomic composition of these exceptional groups. Data from the North Carolina Childhood Lead Poisoning Prevention Program surveillance registry were linked at the individual child level to educational outcomes available through the North Carolina Education Research Data Center. Designation into exceptionality groups was obtained from the end-of-grade (EOG) data. Both standard bivariate and multivariate analyses were employed. Bivariate analyses indicate that blood lead levels and reading EOG scores differ by exceptionality, as well as by race and enrollment in free/reduced lunch. Logistic regression confirmed the relationship between blood lead levels and likelihood of exceptionality. Contextual factors – enrollment in the free/reduced lunch program, race, and parental education – are also significant with regard to exceptionality. This study demonstrates that early childhood lead exposure significantly influences the likelihood of being designated exceptional. These results provide additional evidence that early childhood lead exposure is a significant explanator of the achievement gap. PMID:21533004

  17. Sex-linked dominant

    MedlinePlus

    Inheritance - sex-linked dominant; Genetics - sex-linked dominant; X-linked dominant; Y-linked dominant ... can be either an autosomal chromosome or a sex chromosome. It also depends on whether the trait ...

  18. Functional Generalized Additive Models.

    PubMed

    McLean, Mathew W; Hooker, Giles; Staicu, Ana-Maria; Scheipl, Fabian; Ruppert, David

    2014-01-01

    We introduce the functional generalized additive model (FGAM), a novel regression model for association studies between a scalar response and a functional predictor. We model the link-transformed mean response as the integral with respect to t of F{X(t), t} where F(·,·) is an unknown regression function and X(t) is a functional covariate. Rather than having an additive model in a finite number of principal components as in Müller and Yao (2008), our model incorporates the functional predictor directly and thus our model can be viewed as the natural functional extension of generalized additive models. We estimate F(·,·) using tensor-product B-splines with roughness penalties. A pointwise quantile transformation of the functional predictor is also considered to ensure each tensor-product B-spline has observed data on its support. The methods are evaluated using simulated data and their predictive performance is compared with other competing scalar-on-function regression alternatives. We illustrate the usefulness of our approach through an application to brain tractography, where X(t) is a signal from diffusion tensor imaging at position, t, along a tract in the brain. In one example, the response is disease-status (case or control) and in a second example, it is the score on a cognitive test. R code for performing the simulations and fitting the FGAM can be found in supplemental materials available online.

  19. Multiple Pathways Linking Racism to Health Outcomes.

    PubMed

    Harrell, Camara Jules P; Burford, Tanisha I; Cage, Brandi N; Nelson, Travette McNair; Shearon, Sheronda; Thompson, Adrian; Green, Steven

    2011-04-15

    This commentary discusses advances in the conceptual understanding of racism and selected research findings in the social neurosciences. The traditional stress and coping model holds that racism constitutes a source of aversive experiences that, when perceived by the individual, eventually lead to poor health outcomes. Current evidence points to additional psychophysiological pathways linking facets of racist environments with physiological reactions that contribute to disease. The alternative pathways emphasize prenatal experiences, subcortical emotional neural circuits, conscious and preconscious emotion regulation, perseverative cognitions, and negative affective states stemming from racist cognitive schemata. Recognition of these pathways challenges change agents to use an array of cognitive and self-controlling interventions in mitigating racism's impact. Additionally, it charges policy makers to develop strategies that eliminate deep-seated structural aspects of racism in society.

  20. Security Concepts for Satellite Links

    NASA Astrophysics Data System (ADS)

    Tobehn, C.; Penné, B.; Rathje, R.; Weigl, A.; Gorecki, Ch.; Michalik, H.

    2008-08-01

    The high costs to develop, launch and maintain a satellite network makes protecting the assets imperative. Attacks may be passive such as eavesdropping on the payload data. More serious threat are active attacks that try to gain control of the satellite, which may lead to the total lost of the satellite asset. To counter these threats, new satellite and ground systems are using cryptographic technologies to provide a range of services: confidentiality, entity & message authentication, and data integrity. Additionally, key management cryptographic services are required to support these services. This paper describes the key points of current satellite control and operations, that are authentication of the access to the satellite TMTC link and encryption of security relevant TM/TC data. For payload data management the key points are multi-user ground station access and high data rates both requiring frequent updates and uploads of keys with the corresponding key management methods. For secure satellite management authentication & key negotiation algorithms as HMAC-RIPEMD160, EC- DSA and EC-DH are used. Encryption of data uses algorithms as IDEA, AES, Triple-DES, or other. A channel coding and encryption unit for payload data provides download data rates up to Nx250 Mbps. The presented concepts are based on our experience and heritage of the security systems for all German MOD satellite projects (SATCOMBw2, SAR-Lupe multi- satellite system and German-French SAR-Lupe-Helios- II systems inter-operability) as well as for further international (KOMPSAT-II Payload data link system) and ESA activities (TMTC security and GMES).

  1. Dielectric and piezoelectric properties of lead-free 0.5Ba(Zr0.2 Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 piezoelectric ceramics with glass additive.

    PubMed

    Im, In-Ho; Chung, Kwang-Hyun

    2014-12-01

    We have investigated the dielectric and piezoelectric properties of lead-free 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics with BaO-CaO-SiO2 glass additive as a function of sintering temperatures. With adding BaO-CaO-SiO2 glass additive, diffusivity of lead-free 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics was increased. The dispersion constant γ of BZT-BCT ceramics with BaO-CaO-SiO2 glass was changed from 1.9683 to 1.7673 by decreasing sintering temperature ranging from 1450 degrees C to 1350 degrees C, while 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics at sintered 1450 degrees C showed γ = 1.5055. The piezoelectric properties such as electromechanical coupling factor (k(p)) and piezoelectric constant (d33) of lead-free 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics with BaO-CaO-SiO2 glass additive sintered at 1400 degrees C showed similar values compared with 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics without BaO-CaO-SiO2 glass additive sintered at 1450 degrees C. The addition of BaO-CaO-SiO2 glass additive can be of help to decrease sintering temperature of lead-free 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics.

  2. Dielectric and piezoelectric properties of lead-free 0.5Ba(Zr0.2 Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 piezoelectric ceramics with glass additive.

    PubMed

    Im, In-Ho; Chung, Kwang-Hyun

    2014-12-01

    We have investigated the dielectric and piezoelectric properties of lead-free 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics with BaO-CaO-SiO2 glass additive as a function of sintering temperatures. With adding BaO-CaO-SiO2 glass additive, diffusivity of lead-free 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics was increased. The dispersion constant γ of BZT-BCT ceramics with BaO-CaO-SiO2 glass was changed from 1.9683 to 1.7673 by decreasing sintering temperature ranging from 1450 degrees C to 1350 degrees C, while 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics at sintered 1450 degrees C showed γ = 1.5055. The piezoelectric properties such as electromechanical coupling factor (k(p)) and piezoelectric constant (d33) of lead-free 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics with BaO-CaO-SiO2 glass additive sintered at 1400 degrees C showed similar values compared with 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics without BaO-CaO-SiO2 glass additive sintered at 1450 degrees C. The addition of BaO-CaO-SiO2 glass additive can be of help to decrease sintering temperature of lead-free 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics. PMID:25970982

  3. Environmental lead in Mexico

    SciTech Connect

    Albert, L.A.; Badillo, F. )

    1991-01-01

    From the data presented here, it can be concluded that environmental exposure to lead is a particularly severe problem in Mexico. As has been shown, there are very important sources of exposure to this metal: (a) for rural populations who manufacture and/or utilize lead-glazed pottery, (b) for urban populations who are exposed to high air lead concentrations due to the continued use of lead fuel additives, (c) for workers of several industries, mainly those of batteries and pigments, (d) for consumers who routinely eat canned foods such as hot peppers and fruit products, and (e) for the general population living in the vicinity of smelters, refineries and other industries that emit lead. Therefore, in Mexico only those native populations living in very primitive communities, far away from all civilized life, could be expected to be free from this exposure. At the same time, and despite the relatively few data available, it can be stated that the exposure to lead of populations in Mexico could be approaching levels that might be highly hazardous, in particular for the neuropsychological health of children. Regarding the presence of lead in the environment, despite the fact that the available studies are not enough, it is evident that pollution by this metal is widespread and that there is a serious lack of studies for most regions of the country, including several that might be expected to be highly polluted. At the same time, it is evident that the official attention paid to the problem, either in regulations, support of further studies, or implementation of effective control measures has been far from the level needed according to the available data.

  4. The Missing Link: Teaching the Dispositions to Lead

    ERIC Educational Resources Information Center

    Allen, James G.; Wasicsko, M. Mark; Chirichello, Michael

    2014-01-01

    In this article the authors contend that the element that is typically missing or underdeveloped in the education and development of most leaders is the intentional integration of the research and practices for assessing and developing the deeply held core beliefs, attitudes, and values (what we will call leadership dispositions) that play a…

  5. Lead Poisoning and the Suburban Child

    ERIC Educational Resources Information Center

    Graham, Ada; Graham, Frank

    1974-01-01

    Reports on recent findings which suggest that lead poisoning stems not only from paint ingestion, is not limited to ghetto children, and may be linked to some learning and behavioral difficulties in children. (Author/SF)

  6. Lead and Copper Control 101

    EPA Science Inventory

    This presentation is an overview of the most important water treatment strategies for the control of lead and copper release from drinking water corrosion. In addition to the sections specifically on lead and copper treatment, sections are included that cover sampling to find le...

  7. Peroxidase induced oligo-tyrosine cross-links during polymerization of α-lactalbumin.

    PubMed

    Dhayal, Surender Kumar; Sforza, Stefano; Wierenga, Peter A; Gruppen, Harry

    2015-12-01

    Horseradish peroxidase (HRP) induced cross-linking of proteins has been reported to proceed through formation of di-tyrosine cross-links. In the case of low molar mass phenolic substrates, the enzymatic oxidation is reported to lead to polymerization of the phenols. The aim of this work was to investigate if during oxidative cross-linking of proteins oligo-tyrosine cross-links are formed in addition to dityrosine. To this end, α-lactalbumin (α-LA) was cross-linked using horseradish peroxidase (HRP) and hydrogen peroxide (H₂O₂). The reaction products were acid hydrolysed, after which the cross-linked amino acids were investigated by LC-MS and MALDI-MS. To test the effect of the size of the substrate, the cross-linking reaction was also performed with L-tyrosine, N-acetyl L-tyrosinamide and angiotensin. These products were analyzed by LC-MS directly, as well as after acid hydrolysis. In the acid hydrolysates of all samples oligo-tyrosine (Yn, n=3-8) was found in addition to di-tyrosine (Y2). Two stages of cross-linking of α-LA were identified: a) 1-2 cross-links were formed per monomer until the monomers were converted into oligomers, and b) subsequent cross-linking of oligomers formed in the first stage to form nanoparticles containing 3-4 cross-links per monomer. The transition from first stage to the second stage coincided with the point where di-tyrosine started to decrease and more oligo-tyrosines were formed. In conclusion, extensive polymerization of α-LA using HRP via oligo-tyrosine cross-links is possible, as is the case for low molar mass tyrosine containing substrates. PMID:26282909

  8. The ecotoxicology of lead shot and lead fishing weights.

    PubMed

    Scheuhammer, A M; Norris, S L

    1996-10-01

    : Lead shot ingestion is the primary source of elevated lead exposure and poisoning in waterfowl and most other bird species. For some species (e.g. Common Loons, Gavia immer), lead sinker ingestion is a more frequent cause of lead poisoning. In freshwater environments where recreational angling activity and loon populations co-occur, lead poisoning from ingestion of small (<50 gram) lead sinkers or jigs accounts for 10-50% of recorded adult loon mortality, depending on the locations studied. Lead shot ingestion occurs in waterfowl, and in a wide variety of non-waterfowl species, including upland game birds, shorebirds, raptors, and scavengers. Where it has been explicitly studied in Canada and the US, lead poisoning mortality of bald (Haliacetus leucocephalus) and golden eagles (Aquila chrysactos) from eating prey animals with lead shot embedded in their tissues accounts for an estimated 10-15% of the recorded post-fledging mortality in these raptorial species. In addition to environments that experience hunting with lead shot, clay target shooting ranges, especially those in which the shotfall zones include ponds, marshes, lakes, rivers, beaches, or other aquatic-type environments, create a significant risk of shot ingestion and poisoning for waterbirds. Metallic lead pellets deposited onto soils and aquatic sediments are not chemically or environmentally inert, although tens or hundreds of years may be required for total breakdown and dissolution of pellets. Functional, affordable non-toxic alternatives to lead shot and sinkers are being currently produced, and additional such products are being developed. Several countries have successfully banned the use of small lead sinkers, and of lead shot for waterfowl and other hunting, also for clay target shooting, using a phasing-out process that gives manufactures, sellers, and users adequate time to adjust to the regulations. PMID:24193869

  9. Lead toxicity in older adults.

    PubMed

    Vig, E K; Hu, H

    2000-11-01

    Recent studies have shown that lead, even at relatively low levels of exposure, has the potential to harm not only the young and the occupationally-exposed, but also older people. Because they have been alive for a longer period of time, older adults have had more potential exposures to lead. They may have been exposed to lead while working in unregulated occupations, or they may have encountered more lead in the environment on a daily basis. Several large epidemiological studies have found that older people have higher blood and bone lead levels than younger adults. Additionally, sporadic clusters of acute lead exposure among older adults as a result of activities such as ceramic glaze hobby work and consumption of moonshine whiskey continue to be reported. After lead enters the body, it circulates in the blood reaching the soft tissues and bone. Researchers have learned that lead can hibernate within bone for decades. Although lead within bone is of uncertain toxicity to bone tissue, conditions of bone resorption, such as osteoporosis, can cause bone lead to reenter the bloodstream where it can then re-expose the soft tissue, and, potentially, exert delayed deleterious effects. Evidence is emerging that blood and bone lead levels, reflecting relatively modest exposures, are associated with hypertension, renal insufficiency, and cognitive impairment. Medical treatments that now exist to slow the rate of bone resorption may maintain lead within bones. On-going studies evaluating the relationship between body lead stores and both cognitive and renal impairment, as well as the potential modifying effect of bone resorption, will help determine whether bone resorption should be retarded specifically to preserve organ function. Physicians should be aware of potential past and present lead exposures among their older patients. Ongoing lead exposure should be prevented. In the future, treatment of osteoporosis may be undertaken not only to improve bone health but also to

  10. Lead toxicity in older adults.

    PubMed

    Vig, E K; Hu, H

    2000-11-01

    Recent studies have shown that lead, even at relatively low levels of exposure, has the potential to harm not only the young and the occupationally-exposed, but also older people. Because they have been alive for a longer period of time, older adults have had more potential exposures to lead. They may have been exposed to lead while working in unregulated occupations, or they may have encountered more lead in the environment on a daily basis. Several large epidemiological studies have found that older people have higher blood and bone lead levels than younger adults. Additionally, sporadic clusters of acute lead exposure among older adults as a result of activities such as ceramic glaze hobby work and consumption of moonshine whiskey continue to be reported. After lead enters the body, it circulates in the blood reaching the soft tissues and bone. Researchers have learned that lead can hibernate within bone for decades. Although lead within bone is of uncertain toxicity to bone tissue, conditions of bone resorption, such as osteoporosis, can cause bone lead to reenter the bloodstream where it can then re-expose the soft tissue, and, potentially, exert delayed deleterious effects. Evidence is emerging that blood and bone lead levels, reflecting relatively modest exposures, are associated with hypertension, renal insufficiency, and cognitive impairment. Medical treatments that now exist to slow the rate of bone resorption may maintain lead within bones. On-going studies evaluating the relationship between body lead stores and both cognitive and renal impairment, as well as the potential modifying effect of bone resorption, will help determine whether bone resorption should be retarded specifically to preserve organ function. Physicians should be aware of potential past and present lead exposures among their older patients. Ongoing lead exposure should be prevented. In the future, treatment of osteoporosis may be undertaken not only to improve bone health but also to

  11. Communications Link Characterization Experiment (CLCE)

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Results of the data which were acquired, reduced, and analyzed from the Communications Link Characterization Experiment (CLCE) while utilizing the CTS satellite are presented. The test data obtained from the stations consisted of the results of various TV tests, attenuation and rain rate data. An additional meteorological parameter was measured and it consists of the back scatter returns of the multifrequency weather radar.

  12. Lead Poisoning Prevention Tips

    MedlinePlus

    ... CDC.gov . Lead Home Calendar of Events National Lead Poisoning Prevention Week Archived Materials CDC's Childhood Lead Poisoning Prevention Program Advisory Committee (ACCLPP) Current Activities Blood ...

  13. Lead - nutritional considerations

    MedlinePlus

    Lead poisoning - nutritional considerations; Toxic metal - nutritional considerations ... utensils . Old paint poses the greatest danger for lead poisoning , especially in young children. Tap water from lead ...

  14. Analyzing Optical Communications Links

    NASA Technical Reports Server (NTRS)

    Marshall, William K.; Burk, Brian D.

    1990-01-01

    Optical Communication Link Analysis Program, OPTI, analyzes optical and near-infrared communication links using pulse-position modulation (PPM) and direct detention. Link margins and design-control tables generated from input parameters supplied by user. Enables user to save sets of input parameters that define given link and read them back into program later. Alters automatically any of input parameters to achieve desired link margin. Written in FORTRAN 77.

  15. International perspectives of lead exposure and lead toxicity.

    PubMed

    Grandjean, P

    1993-01-01

    Three approaches have been used to examine how human body burdens of lead depend on different environments: (1) In paleopathologic studies, lead concentrations have been determined in well-preserved human bones or teeth, and pre-pollution samples generally show lead concentrations of about 1% of current levels in industrialized countries. (2) Geographic comparisons of blood-lead concentrations show low levels in, Nepal, Faroe Islands, and Sweden, while high levels occur in Mexico and Malta; average blood-lead levels may vary by a factor of 10 or more. (3) In analytical epidemiology, major exposure sources have been related to lead levels in blood, by either prospective or cross-sectional design. Increased blood-lead concentrations are related to smoking, drinking alcoholic beverages, eating vegetables for dinner, urban residence, and exposure from lead-using industries; average blood-lead values of subgroups within well-defined populations may vary by a factor of 3 or more. The dose-relationships for lead-induced neurotoxicity will depend on the sensitivity of the parameters chosen as indicators of lead exposure and of neurotoxicity. The temporal relationship between lead exposures and the development of deficits must be ascertained. Individual susceptibility and interacting factors must also be taken into account. Differences in addressing these issues impede the comparison between studies. Recently neonatal jaundice has been found to be a risk factor for subsequent neurobehavioral dysfunction in children with a birth weight above 2500 g, but only in children with increased lead exposure. Lead exposure may act in combination with several other factors and result in additive, or synergistic effects.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8247415

  16. Lead levels - blood

    MedlinePlus

    Blood lead levels ... is used to screen people at risk for lead poisoning. This may include industrial workers and children ... also used to measure how well treatment for lead poisoning is working. Lead is common in the ...

  17. 21 CFR 189.240 - Lead solders.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Lead solders. 189.240 Section 189.240 Food and... Addition to Human Food Through Food-Contact Surfaces § 189.240 Lead solders. (a) Lead solders are alloys of metals that include lead and are used in the construction of metal food cans. (b) Food packaged in...

  18. 21 CFR 189.240 - Lead solders.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Lead solders. 189.240 Section 189.240 Food and... Addition to Human Food Through Food-Contact Surfaces § 189.240 Lead solders. (a) Lead solders are alloys of metals that include lead and are used in the construction of metal food cans. (b) Food packaged in...

  19. 21 CFR 189.240 - Lead solders.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lead solders. 189.240 Section 189.240 Food and... Addition to Human Food Through Food-Contact Surfaces § 189.240 Lead solders. (a) Lead solders are alloys of metals that include lead and are used in the construction of metal food cans. (b) Food packaged in...

  20. 21 CFR 189.240 - Lead solders.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Lead solders. 189.240 Section 189.240 Food and... Addition to Human Food Through Food-Contact Surfaces § 189.240 Lead solders. (a) Lead solders are alloys of metals that include lead and are used in the construction of metal food cans. (b) Food packaged in...

  1. Where Will LEAD Lead? An Update on My LEAD Research.

    ERIC Educational Resources Information Center

    Wildman, Louis

    Issues in the future of a federal collaborative program, Leadership in Educational Administration Development (LEAD), are discussed in this paper. Problems attributed to LEAD are its antagonistic posture to educational administration programs in higher education and political conflicts of interest. Methodology involved analysis of successful LEAD…

  2. Potential lead exposures from lead crystal decanters.

    PubMed Central

    Appel, B R; Kahlon, J K; Ferguson, J; Quattrone, A J; Book, S A

    1992-01-01

    We measured the concentrations of lead leached into 4% acetic acid, white port, and a synthetic alcoholic beverage that were stored in lead crystal decanters for 1-, 2-, and 10-day periods at room temperature. In decanters from 14 different manufacturers, measured lead concentrations ranged from 100 to 1800 micrograms/L. The pH of the leaching medium is probably the dominant factor determining the extent of lead leached, with greater leaching occurring at lower pH values. The consumption of alcoholic beverages stored in lead crystal decanters is judged to pose a hazard. PMID:1456345

  3. Lead in petrol. The isotopic lead experiment

    SciTech Connect

    Facchetti, S. )

    1989-10-01

    Many studies were dedicated to the evaluation of the impact of automotive lead on the environment and to the assessment of its absorption in the human population. They can be subdivided into two groups, those based on changes of air and blood lead concentrations and those based on changes of air and blood lead isotopic compositions. According to various authors, 50-66% of the lead added to petrol is mobilized in the atmosphere, while most of the remainder adheres to the walls of the exhaust system from which it is expelled by mechanical and thermal shocks in the forms of easily sedimented particles. The fraction directly emitted by engine exhaust fumes is found in the form of fine particles, which can be transferred a long way from the emitting sources. However important the contribution of petrol lead to the total airborne lead may be, our knowledge does not permit a straightforward calculation of the percentage of petrol lead in total blood lead, which of course can also originate from other sources (e.g., industrial, natural). To evaluate this percentage in 1973, the idea of the Isotopic Lead Experiment (ILE project) was conceived to label, on a regional scale, petrol with a nonradioactive lead of an isotopic composition sufficiently different from that of background lead and sufficiently stable in time. This Account summarizes the main results obtained by the ILE project.

  4. Bone lead, hypertension, and lead nephropathy

    SciTech Connect

    Wedeen, R.P.

    1988-06-01

    There is considerable clinical evidence that excessive lead absorption causes renal failure with hypertension and predisposes individuals to hypertension even in the absence of detectable renal failure. Recent analyses of transiliac bone biopsies indicate that unsuspected elevated bone leads may reflect the cause (or contributing cause) of end-stage renal disease in 5% of the European dialysis population. In these patients, bone lead levels were four times higher than in unexposed cadavers (6 micrograms/g wet weight) and approximated levels found in lead workers (30 micrograms/g). At present, the most reliable index of the body lead burden is the CaNa2 EDTA lead mobilization test. In vivo tibial X-ray-induced X-ray fluorescence (XRF) is a more practical noninvasive technique for assessing bone lead, which should find widespread application as a diagnostic tool and for epidemiologic studies.

  5. Linking flowability and granulometry of lactose powders.

    PubMed

    Boschini, F; Delaval, V; Traina, K; Vandewalle, N; Lumay, G

    2015-10-15

    The flowing properties of 10 lactose powders commonly used in pharmaceutical industries have been analyzed with three recently improved measurement methods. The first method is based on the heap shape measurement. This straightforward measurement method provides two physical parameters (angle of repose αr and static cohesive index σr) allowing to make a first screening of the powder properties. The second method allows to estimate the rheological properties of a powder by analyzing the powder flow in a rotating drum. This more advanced method gives a large set of physical parameters (flowing angle αf, dynamic cohesive index σf, angle of first avalanche αa and powder aeration %ae) leading to deeper interpretations. The third method is an improvement of the classical bulk and tapped density measurements. In addition to the improvement of the measurement precision, the densification dynamics of the powder bulk submitted to taps is analyzed. The link between the macroscopic physical parameters obtained with these methods and the powder granulometry is analyzed. Moreover, the correlations between the different flowability indexes are discussed. Finally, the link between grain shape and flowability is discussed qualitatively.

  6. Adjustable link for kinematic mounting systems

    DOEpatents

    Hale, Layton C.

    1997-01-01

    An adjustable link for kinematic mounting systems. The adjustable link is a low-cost, passive device that provides backlash-free adjustment along its single constraint direction and flexural freedom in all other directions. The adjustable link comprises two spheres, two sockets in which the spheres are adjustable retain, and a connection link threadly connected at each end to the spheres, to provide a single direction of restraint and to adjust the length or distance between the sockets. Six such adjustable links provide for six degrees of freedom for mounting an instrument on a support. The adjustable link has applications in any machine or instrument requiring precision adjustment in six degrees of freedom, isolation from deformations of the supporting platform, and/or additional structural damping. The damping is accomplished by using a hollow connection link that contains an inner rod and a viscoelastic separation layer between the two.

  7. Adjustable link for kinematic mounting systems

    DOEpatents

    Hale, L.C.

    1997-07-01

    An adjustable link for kinematic mounting systems is disclosed. The adjustable link is a low-cost, passive device that provides backlash-free adjustment along its single constraint direction and flexural freedom in all other directions. The adjustable link comprises two spheres, two sockets in which the spheres are adjustable retain, and a connection link threadly connected at each end to the spheres, to provide a single direction of restraint and to adjust the length or distance between the sockets. Six such adjustable links provide for six degrees of freedom for mounting an instrument on a support. The adjustable link has applications in any machine or instrument requiring precision adjustment in six degrees of freedom, isolation from deformations of the supporting platform, and/or additional structural damping. The damping is accomplished by using a hollow connection link that contains an inner rod and a viscoelastic separation layer between the two. 3 figs.

  8. Lead poisoning in children.

    PubMed

    Dapul, Heda; Laraque, Danielle

    2014-08-01

    There is no safe lead level in children. Primary prevention is the most effective way to bring about the complete removal of lead from the environment and eliminate lead poisoning as a public health concern. The National Lead Information Center can be reached via the Internet at www.epa.gov/lead and www.hud.gov/lead, or via phone at 1-800-424-LEAD (5323).

  9. Hierarchical Linked Views

    SciTech Connect

    Erbacher, Robert; Frincke, Deb

    2007-07-02

    Coordinated views have proven critical to the development of effective visualization environments. This results from the fact that a single view or representation of the data cannot show all of the intricacies of a given data set. Additionally, users will often need to correlate more data parameters than can effectively be integrated into a single visual display. Typically, development of multiple-linked views results in an adhoc configuration of views and associated interactions. The hierarchical model we are proposing is geared towards more effective organization of such environments and the views they encompass. At the same time, this model can effectively integrate much of the prior work on interactive and visual frameworks. Additionally, we expand the concept of views to incorporate perceptual views. This is related to the fact that visual displays can have information encoded at various levels of focus. Thus, a global view of the display provides overall trends of the data while focusing in on individual elements provides detailed specifics. By integrating interaction and perception into a single model, we show how one impacts the other. Typically, interaction and perception are considered separately, however, when interaction is being considered at a fundamental level and allowed to direct/modify the visualization directly we must consider them simultaneously and how they impact one another.

  10. Interfacial Bioorthogonal Cross-Linking

    PubMed Central

    2015-01-01

    Described herein is interfacial bioorthogonal cross-linking, the use of bioorthogonal chemistry to create and pattern biomaterials through diffusion-controlled gelation at the liquid-gel interface. The basis is a rapid (k2 284000 M–1 s–1) reaction between strained trans-cyclooctene (TCO) and tetrazine (Tz) derivatives. Syringe delivery of Tz-functionalized hyaluronic acid (HA-Tz) to a bath of bis-TCO cross-linker instantly creates microspheres with a cross-linked shell through which bis-TCO diffuses freely to introduce further cross-linking at the interface. Tags can be introduced with 3D resolution without external triggers or templates. Water-filled hydrogel channels were prepared by simply reversing the order of addition. Prostate cancer cells encapsulated in the microspheres have 99% viability, proliferate readily, and form aggregated clusters. This process is projected to be useful in the fabrication of cell-instructive matrices for in vitro tissue models. PMID:25177528

  11. Commercial Web Site Links.

    ERIC Educational Resources Information Center

    Thelwall, Mike

    2001-01-01

    Discusses business use of the Web and related search engine design issues as well as research on general and academic links before reporting on a survey of the links published by a collection of business Web sites. Results indicate around 66% of Web sites do carry external links, most of which are targeted at a specific purpose, but about 17%…

  12. Lead and the Romans

    ERIC Educational Resources Information Center

    Reddy, Aravind; Braun, Charles L.

    2010-01-01

    Lead poisoning has been a problem since early history and continues into modern times. An appealing characteristic of lead is that many lead salts are sweet. In the absence of cane and beet sugars, early Romans used "sugar of lead" (lead acetate) to sweeten desserts, fruits, and sour wine. People most at risk would have been those who consumed the…

  13. Stibine filter for antimonial lead acid batteries

    SciTech Connect

    Carder, J.H.; Le, A.H.; Dacres, C.M.

    1986-07-03

    This patent application relates to storage cells and more particulary to stibine filters for antimonial lead-acid storage cells. The addition of small amounts of antimony to lead produces lead electrodes having greatly improved mechanical properties. This substantially increases the life of lead-acid batteries. Stibine is removed from gases generated in antimonial lead-acid batteries by using a filter having carbon powder (especially activated charcoal) as the active agent.

  14. Mechanisms linking obesity to male infertility

    PubMed Central

    2015-01-01

    Introduction Obesity in men is associated with infertility in numerous studies. The current trend for decline in semen parameters parallels the increasing prevalence of obesity worldwide. In addition to impaired semen quality, fertility among obese men may be affected by sexual dysfunction, endocrinopathy, aromatization activity, psychological and thermal effects, sleep apnea, leptin and minor toxins, and possibly the inflammatory and obstructive elements of epididymitis pathology. The variable degrees of certainty associated with these causes parallel the levels of supporting evidence. This search aims to shed lights on different conditions that obese men suffer from; as that makes the treatment of infertility more categorized. Material and methods A PubMed search was conducted to identify clinical and pathological mechanisms linking obesity to male infertility. Results Among the myriad of publications reviewed in this paper, impaired spermatogenesis and sexual dysfunction have been shown to drive other variables towards poor fertility potentials. The paper presented a new, detailed flow chart showing more factors and further interactions among conditions leading to infertility. Conclusions The prime hormonal defect in obese men is hypotestosteronaemia, which results in impaired spermatogenesis leading to poor fecundability. Studies have shown that most mechanisms accounting for reduced fertility potentials in overweight men are reversible. PMID:25914843

  15. The effect of cross-link distributions in axially-ordered, cross-linked networks

    PubMed Central

    Bennett, C. Brad; Kruczek, James; Rabson, D. A.; Matthews, W. Garrett; Pandit, Sagar A.

    2013-01-01

    Cross-linking between the constituent chains of biopolymers has a marked effect on their materials properties. In certain of these materials, such as fibrillar collagen, increases in cross-linking lead to an increase in the melting temperature. Fibrillar collagen is an axially-ordered network of cross-linked polymer chains exhibiting a broadened denaturation transition, which has been explained in terms of the successive denaturation with temperature of multiple species. We model axially-ordered cross-linked materials as stiff chains with distinct arrangements of cross-link-forming sites. Simulations suggest that systems composed of chains with identical arrangements of cross-link-forming sites exhibit critical behavior. In contrast, systems composed of non-identical chains undergo a crossover. This model suggests that the arrangement of cross-link-forming sites may contribute to the broadening of the denaturation transition in fibrillar collagen. PMID:23751928

  16. Lead-acid battery

    SciTech Connect

    Rowlette, J.J.

    1983-09-20

    A light weight lead-acid battery is disclosed having a positive terminal and a negative terminal and including one or more cells or grid stacks having a plurality of vertically stacked conductive monoplates with positive active material and negative active material deposited on alternating plates in the cell or grid stack. Electrolyte layers positioned between each monoplate are included to provide a battery cell having four sides which is capable of being electrically charged and discharged. Two vertical positive bus bars are provided on opposite sides of the battery cell for connecting the monoplates with positive active material together in parallel current conducting relation. In addition, two negative bus bars on opposite sides of the battery cell each being adjacent the positive bus bars are provided for connecting the monoplates with negative active material together in parallel current conducting relation. The positive and negative bus bars not only provide a low resistance method for connecting the plurality of conductive monoplates of their respective battery terminals but also provides support and structural strength to the battery cell structure. In addition, horizontal orientation of monoplates is provided in a vertical stacking arrangement to reduce electrolyte stratification and short circuiting due to flaking of positive and negative active materials from the monoplates.

  17. Lead-acid battery

    NASA Technical Reports Server (NTRS)

    Rowlette, John J. (Inventor)

    1983-01-01

    A light weight lead-acid battery (30) having a positive terminal (36) and a negative terminal (34) and including one or more cells or grid stacks having a plurality of vertically stacked conductive monoplates (10, 20) with positive active material and negative active material deposited on alternating plates in the cell or grid stack. Electrolyte layers (26, 28) positioned between each monoplate are included to provide a battery cell having four sides which is capable of being electrically charged and discharged. Two vertical positive bus bars (42, 43) are provided on opposite sides of the battery cell for connecting the monoplates (10) with positive active material together in parallel current conducting relation. In addition, two negative bus bars (38, 39) on opposite sides of the battery cell each being adjacent the positive bus bars are provided for connecting the monoplates (20) with negative active material together in parallel current conducting relation. The positive (42, 43) and negative (38, 39) bus bars not only provide a low resistance method for connecting the plurality of conductive monoplates of their respective battery terminals (36, 34) but also provides support and structural strength to the battery cell structure. In addition, horizontal orientation of monoplates (10, 20) is provided in a vertical stacking arrangement to reduce electrolyte stratification and short circuiting due to flaking of positive and negative active materials from the monoplates.

  18. Target engagement in lead generation.

    PubMed

    Durham, Timothy B; Blanco, Maria-Jesus

    2015-03-01

    The pharmaceutical industry is currently facing multiple challenges, in particular the low number of new drug approvals in spite of the high level of R&D investment. In order to improve target selection and assess properly the clinical hypothesis, it is important to start building an integrated drug discovery approach during Lead Generation. This should include special emphasis on evaluating target engagement in the target tissue and linking preclinical to clinical readouts. In this review, we would like to illustrate several strategies and technologies for assessing target engagement and the value of its application to medicinal chemistry efforts.

  19. 55. VIEW OF ROASTER ADDITION FROM NORTH. ELEVATOR/ORE BIN ADDITION ...

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

    55. VIEW OF ROASTER ADDITION FROM NORTH. ELEVATOR/ORE BIN ADDITION TO RIGHT (WEST) WITH BAKER COOLER IN FRONT. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  20. Lead Surveillance Program

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Background on lead exposure is presented including forms of lead, sources, hematologic effects, neurologic effects, endocrine effects, renal effects, and reproductive and developmental effects. The purpose of the Lead Surveillance Program at LeRC is outlined, and the specifics of the Medical Surveillance Program for Lead Exposure at LeRC are discussed.

  1. Object linking in repositories

    NASA Technical Reports Server (NTRS)

    Eichmann, David (Editor); Beck, Jon; Atkins, John; Bailey, Bill

    1992-01-01

    This topic is covered in three sections. The first section explores some of the architectural ramifications of extending the Eichmann/Atkins lattice-based classification scheme to encompass the assets of the full life cycle of software development. A model is considered that provides explicit links between objects in addition to the edges connecting classification vertices in the standard lattice. The second section gives a description of the efforts to implement the repository architecture using a commercially available object-oriented database management system. Some of the features of this implementation are described, and some of the next steps to be taken to produce a working prototype of the repository are pointed out. In the final section, it is argued that design and instantiation of reusable components have competing criteria (design-for-reuse strives for generality, design-with-reuse strives for specificity) and that providing mechanisms for each can be complementary rather than antagonistic. In particular, it is demonstrated how program slicing techniques can be applied to customization of reusable components.

  2. Improving interdependent networks robustness by adding connectivity links

    NASA Astrophysics Data System (ADS)

    Ji, Xingpei; Wang, Bo; Liu, Dichen; Chen, Guo; Tang, Fei; Wei, Daqian; Tu, Lian

    2016-02-01

    Compared with a single and isolated network, interdependent networks have two types of links: connectivity link and dependency link. This paper aims to improve the robustness of interdependent networks by adding connectivity links. Firstly, interdependent networks failure model and four frequently used link addition strategies are briefly reviewed. Furthermore, by defining inter degree-degree difference, two novel link addition strategies are proposed. Finally, we verify the effectiveness of our proposed link addition strategies by comparing with the current link addition strategies in three different network models. The simulation results show that, given the number of added links, link allocation strategies have great effects on the robustness of interdependent networks, i.e., the double-network link allocation strategy is superior to single-network link allocation strategy. Link addition strategies proposed in this paper excel the current strategies, especially for BA interdependent networks. Moreover, our work can provide guidance on how to allocate limited resources to an existing interdependent networks system and optimize its topology to avoid the potential cascade failures.

  3. [Noroviruses: leading cause of gastroenteritis].

    PubMed

    Delacour, H; Dubrous, P; Koeck, J L

    2010-04-01

    Although noroviruses were the first viral agents to be linked to gastrointestinal disease, they were long considered a secondary cause far behind rotaviruses. Development of molecular-based diagnostic techniques has provided clearer insight into the epidemiological impact of noroviruses that are now recognized not only as the leading cause of non-bacterial gastroenteritis outbreaks but also as an important cause of sporadic gastroenteritis in both children and adults. Norovirus infection is generally characterized by mild acute vomiting and diarrhea usually lasting for only a few days, but it can lead to more severe and potentially life-threatening symptoms in high-risk groups such as young children, elderly, and immunodeficient persons. It has been demonstrated that they are present in tropical countries. Molecular epidemiological studies have documented the great genetic diversity of noroviruses with regular emergence of variants. Since no vaccine is available, prevention on norovirus infection depends mainly on strict personal and community hygiene measures.

  4. Contribution of lead from calcium supplements to blood lead.

    PubMed Central

    Gulson, B L; Mizon, K J; Palmer, J M; Korsch, M J; Taylor, A J

    2001-01-01

    blood lead concentration during treatment, there are significant changes in the isotopic composition of lead in blood arising from the calcium carbonate supplement, indicating a limited input of lead from diet into the blood. Because calcium carbonate is overwhelmingly the most popular calcium supplement, the changes we have observed merit further investigation. In addition, this type of study, combined with a duplicate diet, needs to be repeated for children, whose fractional absorption of lead is considerably higher than that of adults. PMID:11333190

  5. Chemical and thermal cross-linking of collagen and elastin hydrolysates.

    PubMed

    Sionkowska, A; Skopinska-Wisniewska, J; Gawron, M; Kozlowska, J; Planecka, A

    2010-11-01

    Chemical and thermal cross-linking of collagen soluble in acetic acid and elastin hydrolysates soluble in water have been studied. Solutions of collagen and elastin hydrolysates were treated using variable concentrations of 1-ethyl-3(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). Moreover, diepoxypropylether (DEPE) has been used as cross-linking agent. Films made of collagen and elastin hydrolysates were also treated with temperature at 60°C and 100°C to get additional cross-links. The effect of cross-linking has been studied using FTIR spectroscopy, thermal analysis, AFM and SEM microscopy. Mechanical and surface properties of materials have been studied after cross-linking. It was found that thermal and mechanical properties of collagen and elastin materials have been altered after thermal treatment and after the reactions with EDC/NHS and/or DEPE. Surface properties of collagen materials after chemical cross-linking have been modified. Thermal and chemical cross-linking of collagen films lead to alteration of polarity of the surface.

  6. Efficient network disintegration under incomplete information: the comic effect of link prediction

    NASA Astrophysics Data System (ADS)

    Tan, Suo-Yi; Wu, Jun; Lü, Linyuan; Li, Meng-Jun; Lu, Xin

    2016-03-01

    The study of network disintegration has attracted much attention due to its wide applications, including suppressing the epidemic spreading, destabilizing terrorist network, preventing financial contagion, controlling the rumor diffusion and perturbing cancer networks. The crux of this matter is to find the critical nodes whose removal will lead to network collapse. This paper studies the disintegration of networks with incomplete link information. An effective method is proposed to find the critical nodes by the assistance of link prediction techniques. Extensive experiments in both synthetic and real networks suggest that, by using link prediction method to recover partial missing links in advance, the method can largely improve the network disintegration performance. Besides, to our surprise, we find that when the size of missing information is relatively small, our method even outperforms than the results based on complete information. We refer to this phenomenon as the “comic effect” of link prediction, which means that the network is reshaped through the addition of some links that identified by link prediction algorithms, and the reshaped network is like an exaggerated but characteristic comic of the original one, where the important parts are emphasized.

  7. Efficient network disintegration under incomplete information: the comic effect of link prediction

    PubMed Central

    Tan, Suo-Yi; Wu, Jun; Lü, Linyuan; Li, Meng-Jun; Lu, Xin

    2016-01-01

    The study of network disintegration has attracted much attention due to its wide applications, including suppressing the epidemic spreading, destabilizing terrorist network, preventing financial contagion, controlling the rumor diffusion and perturbing cancer networks. The crux of this matter is to find the critical nodes whose removal will lead to network collapse. This paper studies the disintegration of networks with incomplete link information. An effective method is proposed to find the critical nodes by the assistance of link prediction techniques. Extensive experiments in both synthetic and real networks suggest that, by using link prediction method to recover partial missing links in advance, the method can largely improve the network disintegration performance. Besides, to our surprise, we find that when the size of missing information is relatively small, our method even outperforms than the results based on complete information. We refer to this phenomenon as the “comic effect” of link prediction, which means that the network is reshaped through the addition of some links that identified by link prediction algorithms, and the reshaped network is like an exaggerated but characteristic comic of the original one, where the important parts are emphasized. PMID:26960247

  8. Efficient network disintegration under incomplete information: the comic effect of link prediction.

    PubMed

    Tan, Suo-Yi; Wu, Jun; Lü, Linyuan; Li, Meng-Jun; Lu, Xin

    2016-03-10

    The study of network disintegration has attracted much attention due to its wide applications, including suppressing the epidemic spreading, destabilizing terrorist network, preventing financial contagion, controlling the rumor diffusion and perturbing cancer networks. The crux of this matter is to find the critical nodes whose removal will lead to network collapse. This paper studies the disintegration of networks with incomplete link information. An effective method is proposed to find the critical nodes by the assistance of link prediction techniques. Extensive experiments in both synthetic and real networks suggest that, by using link prediction method to recover partial missing links in advance, the method can largely improve the network disintegration performance. Besides, to our surprise, we find that when the size of missing information is relatively small, our method even outperforms than the results based on complete information. We refer to this phenomenon as the "comic effect" of link prediction, which means that the network is reshaped through the addition of some links that identified by link prediction algorithms, and the reshaped network is like an exaggerated but characteristic comic of the original one, where the important parts are emphasized.

  9. Efficient network disintegration under incomplete information: the comic effect of link prediction.

    PubMed

    Tan, Suo-Yi; Wu, Jun; Lü, Linyuan; Li, Meng-Jun; Lu, Xin

    2016-01-01

    The study of network disintegration has attracted much attention due to its wide applications, including suppressing the epidemic spreading, destabilizing terrorist network, preventing financial contagion, controlling the rumor diffusion and perturbing cancer networks. The crux of this matter is to find the critical nodes whose removal will lead to network collapse. This paper studies the disintegration of networks with incomplete link information. An effective method is proposed to find the critical nodes by the assistance of link prediction techniques. Extensive experiments in both synthetic and real networks suggest that, by using link prediction method to recover partial missing links in advance, the method can largely improve the network disintegration performance. Besides, to our surprise, we find that when the size of missing information is relatively small, our method even outperforms than the results based on complete information. We refer to this phenomenon as the "comic effect" of link prediction, which means that the network is reshaped through the addition of some links that identified by link prediction algorithms, and the reshaped network is like an exaggerated but characteristic comic of the original one, where the important parts are emphasized. PMID:26960247

  10. Experimental model of lead nephropathy

    SciTech Connect

    Khalil-Manesh, F.; Gonick, H.C. ); Cohen, A. ); Bergamaschi, E.; Mutti, A. )

    1992-06-01

    Male Sprague-Dawley rats were exposed to high-dose (0.5%) lead acetate for periods ranging from 1 to 9 months; then lead exposure was discontinued, and animals were sacrificed after 12 months. Two additional groups of low-dose (0.01%) and high-dose (0.5%) rats were exposed to lead for 6 months, then lead was discontinued and the rats were treated with three 5-day courses of 0.5% DMSA (dimercaptosuccinic acid) over the next 6 months. Low-dose lead-treated rats showed no significant pathological changes with or without DMSA treatment, but exhibited a significant increase in GFR after DMSA. High-dose lead-treated animals showed no functional or pathological changes when lead exposure was discontinued after 1 month. However, when duration of exposure was 6 or 9 months, GFR was decreased and serum creatinine and urea nitrogen were increased as compared to controls. Tubulointerstitial disease was severe. Administration of DMSA resulted in an improvement in GFR and a decrease in albuminuria, together with a reduction in size and number of nuclear inclusion bodies in proximal tubules. However, tubulointerstitial scarring was only minimally reduced. It may be concluded that, except for brief initial exposure, discontinuation of high-dose lead exposure fails to reverse lead-induced renal damage. Treatment with the chelator, DMSA, improves renal function but has less effect on pathological alterations. As GFR improved after DMSA treatment in both low-dose and high-dose lead-treated rats, irrespective of the degree of pathological alterations, it may be concluded that the DMSA effect is most likely mediated by hemodynamic changes.

  11. Spatial-Operator Algebra For Flexible-Link Manipulators

    NASA Technical Reports Server (NTRS)

    Jain, Abhinandan; Rodriguez, Guillermo

    1994-01-01

    Method of computing dynamics of multiple-flexible-link robotic manipulators based on spatial-operator algebra, which originally applied to rigid-link manipulators. Aspects of spatial-operator-algebra approach described in several previous articles in NASA Tech Briefs-most recently "Robot Control Based on Spatial-Operator Algebra" (NPO-17918). In extension of spatial-operator algebra to manipulators with flexible links, each link represented by finite-element model: mass of flexible link apportioned among smaller, lumped-mass rigid bodies, coupling of motions expressed in terms of vibrational modes. This leads to operator expression for modal-mass matrix of link.

  12. Lead isotope ratios for bullets, a descriptive approach for investigative purposes and a new method for sampling of bullet lead.

    PubMed

    Sjåstad, Knut-Endre; Simonsen, Siri Lene; Andersen, Tom H

    2014-11-01

    To establish a link between a bullet fired from a suspected firearm, investigation of striation marks are one of the corner stones in the forensic laboratory. Nevertheless, on some occasions, the bullet may be deformed to such extent that traditional investigation of striation marks will be impossible. Fragments of lead can be investigated by lead isotope ratio determination in order to distinguish between bullets with different origin. This approach initially seems reasonable, since the abundance of lead isotopes varies significantly in nature. To make a method valid for forensic purposes, it is important to have a fundamental understanding of the variation within a box of lead bullets and the expected variation between boxes. Studies of variability within and between boxes of ammunition are imperative to perform any type of forensic interpretation, both in an investigative and evaluative context. This work presents an extensive study of variability within and between boxes of ammunition by use of multicollector inductive coupled mass spectrometry. As a first approximation to classify bullets to any given source, a simple and robust graphical method is presented. In addition, an easy-to-use sampling procedure of lead is presented.

  13. [Food additives and healthiness].

    PubMed

    Heinonen, Marina

    2014-01-01

    Additives are used for improving food structure or preventing its spoilage, for example. Many substances used as additives are also naturally present in food. The safety of additives is evaluated according to commonly agreed principles. If high concentrations of an additive cause adverse health effects for humans, a limit of acceptable daily intake (ADI) is set for it. An additive is a risk only when ADI is exceeded. The healthiness of food is measured on the basis of nutrient density and scientifically proven effects.

  14. Determination of exposure to lead of subjects from southwestern Poland by human hair analysis.

    PubMed

    Michalak, Izabela; Wołowiec, Paulina; Chojnacka, Katarzyna

    2014-04-01

    The aim of the present work was to investigate the exposure to lead from various sources by investigation of mineral composition of human scalp hair. The research was carried out on hair sampled from 267 young adults living in Wrocław (southwest Poland). The effect of the place of residence, diet, and lifestyle on lead content in hair was examined by inductively coupled plasma optical emission spectrometry (ICP-OES). Lead was determined at the wavelength 220.353 nm. These outcomes were reached by linking the results of lead level in hair with the results of questionnaire survey. The mean lead level in hair of the whole examined population was 2.01 ± 2.10 mg kg(-1). Lead can enter the human body mainly by inhalation and gastrointestinal absorption. It was found that consuming cheese, fish, and lettuce caused increased level of lead in hair. On the other hand, drinking of milk, tea, coffee, or lemon resulted in decreased content of lead in hair. Additional source of exposure to lead could be cigarette smoking, distance to the traffic road, painting the walls, amalgam filling. Based on the results, it can be concluded that exposure to lead can occur mainly from eating habits and environmental exposure. PMID:24346348

  15. Composite lead for conducting an electrical current between 75--80K and 4. 5K temperatures

    DOEpatents

    Negm, Y.; Zimmerman, G.O.; Powers, R.E. Jr.; McConeghy, R.J.; Kaplan, A.

    1994-12-27

    A composite lead is provided which electrically links and conducts a current between about 75-80K and liquid helium temperature of about 4.5K. The composite lead may be employed singly or in multiples concurrently to provide conduction of electrical current from normal conductors and semi-conductors at room temperature to superconductors operating at 4.5K. In addition, a variety of organizational arrangements and assemblies are provided by which the mechanical strength and electrical reliability of the composite lead is maintained. 12 figures.

  16. Composite lead for conducting an electrical current between 75-80K and 4.5K temperatures

    DOEpatents

    Negm, Yehia; Zimmerman, George O.; Powers, Jr., Robert E.; McConeghy, Randy J.; Kaplan, Alvaro

    1994-12-27

    A composite lead is provided which electrically links and conducts a current between about 75-80K. and liquid helium temperature of about 4.5K. The composite lead may be employed singly or in multiples concurrently to provide conduction of electrical current from normal conductors and semi-conductors at room temperature to superconductors operating at 4.5K. In addition, a variety of organizationl arrangements and assemblies are provided by which the mechanical strength and electrical reliability of the composite lead is maintained.

  17. Synthesising Topological Links

    PubMed Central

    Baas, Nils A.; Seeman, Nadrian C.; Stacey, Andrew

    2014-01-01

    We discuss the chemical synthesis of topological links, in particular higher order links which have the Brunnian property (namely that removal of any one component unlinks the entire system). Furthermore, we suggest how to obtain both two dimensional and three dimensional objects (surfaces and solids, respectively) which also have this Brunnian property. PMID:25678732

  18. A West African Link

    ERIC Educational Resources Information Center

    Cook, Angela; Davies, Penny

    2003-01-01

    The authors visited Ghana in West Africa to strengthen a link established the previous year as part of Channel 4's "On the Line" project. The initial link established in 1999/2000 was between an all-age special school in Enfield and a similar school in Accra. Over the course of that year further partnerships were created between five UK schools…

  19. HLA-linked rheumatoid arthritis

    SciTech Connect

    Hasstedt, S.J.; Clegg, D.O.; Ingles, L.; Ward, R.H.

    1994-10-01

    Twenty-eight pedigrees were ascertained through pairs of first-degree relatives diagnosed with rheumatoid arthritis (RA). RA was confirmed in 77 pedigree members including probands; the absence of disease was verified in an additional 261 pedigree members. Pedigree members were serologically typed for HLA. We used likelihood analysis to statistically characterize the HLA-linked RA susceptibility locus. The genetic model assumed tight linkage to HLA. The analysis supported the existence of an HLA-linked RA susceptibility locus, estimated the lifetime penetrance as 41% in male homozygotes and as 48% in female homozygotes. Inheritance was recessive in males and was nearly recessive in females. In addition, the analysis attributed 78% of the variance within genotypes to genetic or environmental effects shared by siblings. The genetic model inferred in this analysis is consistent with previous association, linkage, and familial aggregation studies of RA. The inferred HLA-linked RA susceptibility locus accounts for approximately one-fifth of the RA in the population. Although other genes may account for the remaining familial RA, a large portion of RA cases may occur sporadically. 79 refs., 9 tabs.

  20. The identification of lead ammunition as a source of lead exposure in First Nations: the use of lead isotope ratios.

    PubMed

    Tsuji, Leonard J S; Wainman, Bruce C; Martin, Ian D; Sutherland, Celine; Weber, Jean-Philippe; Dumas, Pierre; Nieboer, Evert

    2008-04-15

    The use of lead shotshell to hunt water birds has been associated with lead-contamination in game meat. However, evidence illustrating that lead shotshell is a source of lead exposure in subsistence hunting groups cannot be deemed definitive. This study seeks to determine whether lead shotshell constitutes a source of lead exposure using lead isotope ratios. We examined stable lead isotope ratios for lichens, lead shotshell and bullets, and blood from residents of Fort Albany and Kashechewan First Nations, and the City of Hamilton, Ontario, Canada. Data were analyzed using ANOVA and regression analyses. ANOVA of isotope ratios for blood revealed significant differences with respect to location, but not sex. Hamilton differed from both Kashechewan and Fort Albany; however, the First Nations did not differ from each other. ANOVA of the isotope ratios for lead ammunition and lichens revealed no significant differences between lichen groups (north and south) and for the lead ammunition sources (pellets and bullets). A plot of (206)Pb/(204)Pb and (206)Pb/(207)Pb values illustrated that lichens and lead ammunition were distinct groupings and only the 95% confidence ellipse of the First Nations group overlapped that of lead ammunition. In addition, partial correlations between blood-lead levels (adjusted for age) and isotope ratios revealed significant (p<0.05) positive correlations for (206)Pb/(204)Pb and (206)Pb/(207)Pb, and a significant negative correlation for (208)Pb/(206)Pb, as predicted if leaded ammunition were the source of lead exposure. In conclusion, lead ammunition was identified as a source of lead exposure for First Nations people; however, the isotope ratios for lead shotshell pellets and bullets were indistinguishable. Thus, lead-contaminated meat from game harvested with lead bullets may also be contributing to the lead body burden.

  1. Lead and tap water

    MedlinePlus

    Water contaminated with lead ... The Environmental Protection Agency (EPA) monitors drinking water in the United States. It requires water suppliers to produce annual water quality reports. These reports include information about lead amounts, and they ...

  2. VOLUMETRIC LEAD ASSAY

    SciTech Connect

    M.A. Ebadian, Ph.D.; S.K. Dua; David Roelant; Sachin Kumar

    2001-01-01

    This report describes a system for handling and radioassay of lead, consisting of a robot, a conveyor, and a gamma spectrometer. The report also presents a cost-benefit analysis of options: radioassay and recycling lead vs. disposal as waste.

  3. Exposures to lead.

    PubMed

    Callan, Anna C; Hinwood, Andrea L

    2011-01-01

    The Pacific Basin Consortium for Environment and Health hosted a workshop on Exposures to Lead. Speakers from Australia and the United States of America addressed current research knowledge on lead exposures and health effects in children, risk assessment and communication issues in dealing with lead exposure sources, different methods for assessing exposure, and the variety of scenarios where lead still remains a pollutant of concern. Mining continues to be a source of lead for many communities, and approaches to reducing exposures in these settings present particular challenges. A Perth Declaration for the Global Reduction of Childhood Lead Exposure was signed by participants of the meeting and is aimed at increasing attention to the need to continue to assess lead in the environment and to develop strategies to reduce lead in the environment and exposure by communities. PMID:21714377

  4. Exposures to lead.

    PubMed

    Callan, Anna C; Hinwood, Andrea L

    2011-01-01

    The Pacific Basin Consortium for Environment and Health hosted a workshop on Exposures to Lead. Speakers from Australia and the United States of America addressed current research knowledge on lead exposures and health effects in children, risk assessment and communication issues in dealing with lead exposure sources, different methods for assessing exposure, and the variety of scenarios where lead still remains a pollutant of concern. Mining continues to be a source of lead for many communities, and approaches to reducing exposures in these settings present particular challenges. A Perth Declaration for the Global Reduction of Childhood Lead Exposure was signed by participants of the meeting and is aimed at increasing attention to the need to continue to assess lead in the environment and to develop strategies to reduce lead in the environment and exposure by communities.

  5. PHOTOEMISSION PROPERTIES OF LEAD.

    SciTech Connect

    SMEDLEY,J.; RAO,T.; WARREN,J.; SEKUTOWICZ,J.; LEFFERTS,R.; LIPSKI,A.

    2004-07-05

    In this paper we present a study of the photoemission properties of lead at several UV wavelengths, including a study of the damage threshold of electroplated lead under laser cleaning. A quantum efficiency in excess of 0.1% has been achieved for a laser cleaned, electroplated lead sample with a laser wavelength of 193 nm. Niobium cathodes have been measured for comparison, and lead is found to be a superior photoemitter for all measured wavelengths.

  6. Transplacental transport of lead

    SciTech Connect

    Goyer, R.A. )

    1990-11-01

    Neurotoxicity is the major health effect from exposure to lead for infants and young children, and there is current concern regarding possible toxic effects of lead on the child while in utero. there is no placental-fetal barrier to lead transport. Maternal and fetal blood lead levels are nearly identical, so lead passes through the placenta unencumbered. Lead has been measured in the fetal brain as early as the end of the first trimester (13 weeks). There is a similar rate of increase in brain size and lead content throughout pregnancy in the fetus of mothers in the general population, so concentration of lead probably does not differ greatly during gestation unless exposure of the mother changes. Cell-specific sensitivity to the toxic effects of lead, however, may be greater the younger the fetus. Lead toxicity to the nervous system is characterized by edema or swelling of the brain due to altered permeability of capillary endothelial cells. Experimental studies suggest that immature endothelial cells forming the capillaries of the developing brain are less resistant to the effects of lead, permitting fluid and cations including lead to reach newly formed components of the brain, particularly astrocytes and neurons. Also, the ability of astrocytes and neurons to sequester lead in the form of lead protein complexes occurs only in the later stages of fetal development, permitting lead in maturing brain cells to interact with vital subcellular organelles, particularly mitochondria, which are the major cellular energy source. Intracellular lead also affects binding sites for calcium which, in turn, may affect numerous cell functions including neurotransmitter release.

  7. Thermo-cross-linked elastomeric opal films.

    PubMed

    Schäfer, Christian G; Viel, Benjamin; Hellmann, Goetz P; Rehahn, Matthias; Gallei, Markus

    2013-11-13

    An efficient and convenient thermal cross-linking protocol in elastomeric opal films leading to fully reversible and stretch-tunable optical materials is reported. In this study, functional monodisperse core-shell particles were arranged in a face-centered cubic (fcc) lattice structure by a melt flow process. A problem up to now was that un-cross-linked films could not be drawn fully reversibly and hence lost their optical and mechanical performance. After thermal cross-linking reaction, the obtained films can be drawn like rubbers and the color of their Bragg reflection changes because of controlled lattice deformation, which makes the cross-linked films mechanochromic sensors. Different techniques were developed for the cross-linking of the films a posteriori, after their preparation in the melt flow process. A photo-cross-linking approach was reported earlier. This study now deals with a very efficient thermo-cross-linking approach based on the chemistry of hydroxyl- and isocyanate-functionalities that form urethane bridges. The focus of the present work is the mechanism and efficiency of this cross-linking process for elastomeric opal films with excellent mechanical and optical properties. PMID:24134322

  8. Lead Poisoning in Schools.

    ERIC Educational Resources Information Center

    Guyaux, Susan

    1990-01-01

    Overexposure to lead can permanently impair a child's mental and physical development. This article discusses sources of lead paint, survey and testing methods, management and abatement plans, drinking water contamination, and associated federal standards. Although lead is present in soil and in art, theater, and vocational programs, no federal…

  9. Lead Poisoning (For Parents)

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy Lead Poisoning KidsHealth > For Parents > Lead Poisoning Print A A ... Family en español La intoxicación por plomo About Lead Poisoning If you have young kids, it's important to ...

  10. Learn about Lead

    MedlinePlus

    ... Determine if your family is at risk for lead poisoning with the Lead Poisoning Home Checklist (PDF) . Top of page What do I do if I think my child or I have been exposed to lead? Talk to your pediatrician, general physician, or local ...

  11. Lead Poisoning in Children.

    ERIC Educational Resources Information Center

    Boeckx, Roger L.

    1986-01-01

    Urban children are exposed to lead through the air they breathe, the water they drink, and the food and nonfood substances they ingest. The history, diagnosis, and treatment of lead poisoning in these children are discussed. Includes information on the toxicology of lead and the various risk classes. (JN)

  12. Lead Poisoning in Childhood.

    ERIC Educational Resources Information Center

    Pueschel, Siegfried M., Ed.; Linakis, James G., Ed.; Anderson, Angela C., Ed.

    The magnitude of childhood lead poisoning has been inexplicably neglected by modern medicine and by legislators. However, since the 1970s, increased attention has been focused on lead poisoning, and advances have been made in several areas, including understanding of the neurodevelopmental and behavioral ramifications of lead poisoning, and…

  13. Lead Poisoning in Children.

    ERIC Educational Resources Information Center

    Drummond, A. H., Jr.

    1981-01-01

    Early symptoms of lead poisoning in children are often overlooked. Lead poisoning has its greatest effects on the brain and nervous system. The obvious long-term solution to the lead poisoning problem is removal of harmful forms of the metal from the environment. (JN)

  14. Lead and children

    PubMed Central

    Abelsohn, Alan R.; Sanborn, Margaret

    2010-01-01

    Abstract OBJECTIVE To provide family physicians with a practical, evidence-based approach to screening for and preventing children’s exposure to lead. SOURCES OF INFORMATION MEDLINE was searched using terms relevant to lead exposure and poisoning. We reviewed English-language articles published in 2003 to 2008. Most cited studies provide level 2 or 3 evidence. MAIN MESSAGE Lead is a developmental neurotoxin. Children are most commonly exposed and they are most vulnerable. Lead exposure has been associated with many cognitive and motor deficits, as well as distractibility and other characteristics of attention deficit hyperactivity disorder. Although children’s blood lead levels have declined considerably over the past 3 decades with removal of lead from gasoline and paint, children can still be exposed to lead from lead paint in older homes, toys, and other sources. Because post-exposure treatment cannot reverse the cognitive effects of lead exposure, preventing lead exposure is essential. CONCLUSION Family physicians have an important role in screening for children at high risk of lead exposure, and in educating families to prevent the exposure of children to lead. PMID:20547517

  15. Lead poisoning: An overview

    NASA Technical Reports Server (NTRS)

    Gendel, Neil

    1993-01-01

    A problem that should be of great concern to all of us is the lead poisoning of children. First, I would like to present a short overview concerning the reasons everyone should care about lead poisoning, then discuss the history of lead poisoning, what is happening today across the country, and the future.

  16. Lead in Christmas lights.

    PubMed

    Laquatra, Joseph; Coyne, Lelia M; Pierce, Mark R

    2008-12-01

    A recent California proposition led to awareness that lead is a stabilizer in the Polyvinyl Chloride (PVC) jacketing that covers conductors in Christmas lights. The objective of this study is to examine the level of accessible lead in Christmas lights. Following U.S. Environmental Protection Agency (U.S. EPA) Lead Inspectors' procedures, researchers at Cornell University and in Nebraska conducted wipe samples and total lead content samples of newly purchased and older Christmas light sets. Samples were analyzed for lead content. Lead was present in varying amounts on all samples. The amount of lead from the Nebraska samples, normalized to length of strings, was independent of analyzing laboratory, analysis method, age of string, and repeat sampling, both immediately and after extended storage. A later analysis of these same strings by the Cornell team showed diminished quantities. Amounts of surface lead normalized to crude estimates of the area of light string indicated surface concentrations in excess of U.S. EPA clearance level for lead on window sills. Whether exposure to lead in Christmas lights affects blood lead levels in humans is unknown. No standards exist for lead content in this product, and no protocols exist for conducting tests on it. Therefore, consumers may wish to exercise caution to reduce possible exposure.

  17. Object links in the repository

    NASA Technical Reports Server (NTRS)

    Beck, Jon; Eichmann, David

    1991-01-01

    Some of the architectural ramifications of extending the Eichmann/Atkins lattice-based classification scheme to encompass the assets of the full life-cycle of software development are explored. In particular, we wish to consider a model which provides explicit links between objects in addition to the edges connecting classification vertices in the standard lattice. The model we consider uses object-oriented terminology. Thus, the lattice is viewed as a data structure which contains class objects which exhibit inheritance. A description of the types of objects in the repository is presented, followed by a discussion of how they interrelate. We discuss features of the object-oriented model which support these objects and their links, and consider behavior which an implementation of the model should exhibit. Finally, we indicate some thoughts on implementing a prototype of this repository architecture.

  18. Picornavirus infection leading to immunosuppression

    PubMed Central

    Cusick, Matthew F; Libbey, Jane E; Fujinami, Robert S

    2014-01-01

    Viruses, such as HIV, hepatitis A, poliovirus, coxsackievirus B3 and foot-and-mouth disease virus, use a variety of mechanisms to suppress the human immune system in order to evade clearance by the host. Therefore, investigating how a few changes in the viral genome of a nonlethal virus can lead to an alteration in disease, from survivable to immunosuppression and death, would provide valuable information into viral pathogenesis. In addition, we propose that gaining a better insight into how these viruses suppress an antiviral immune response could lead to viral-based therapeutics to combat specifc autoimmune diseases such as multiple sclerosis and Type 1 diabetes. PMID:25214881

  19. Clinical effects of sulphite additives.

    PubMed

    Vally, H; Misso, N L A; Madan, V

    2009-11-01

    Sulphites are widely used as preservative and antioxidant additives in the food and pharmaceutical industries. Topical, oral or parenteral exposure to sulphites has been reported to induce a range of adverse clinical effects in sensitive individuals, ranging from dermatitis, urticaria, flushing, hypotension, abdominal pain and diarrhoea to life-threatening anaphylactic and asthmatic reactions. Exposure to the sulphites arises mainly from the consumption of foods and drinks that contain these additives; however, exposure may also occur through the use of pharmaceutical products, as well as in occupational settings. While contact sensitivity to sulphite additives in topical medications is increasingly being recognized, skin reactions also occur after ingestion of or parenteral exposure to sulphites. Most studies report a 3-10% prevalence of sulphite sensitivity among asthmatic subjects following ingestion of these additives. However, the severity of these reactions varies, and steroid-dependent asthmatics, those with marked airway hyperresponsiveness, and children with chronic asthma, appear to be at greater risk. In addition to episodic and acute symptoms, sulphites may also contribute to chronic skin and respiratory symptoms. To date, the mechanisms underlying sulphite sensitivity remain unclear, although a number of potential mechanisms have been proposed. Physicians should be aware of the range of clinical manifestations of sulphite sensitivity, as well as the potential sources of exposure. Minor modifications to diet or behaviour lead to excellent clinical outcomes for sulphite-sensitive individuals.

  20. Lead-free electric matches.

    SciTech Connect

    Son, S. F.; Hiskey, M. A.; Naud, D.; Busse, J. R.; Asay, B. W.

    2002-01-01

    Electric matches are used in pyrotechnics to initiate devices electrically rather than by burning fuses. Fuses have the disadvantage of burning with a long delay before igniting a pyrotechnic device, while electric matches can instantaneously fire a device at a user's command. In addition, electric matches can be fired remotely at a safe distance. Unfortunately, most current commercial electric match compositions contain lead as thiocyanate, nitroresorcinate or tetroxide, which when burned, produces lead-containing smoke. This lead pollutant presents environmental exposure problems to cast, crew, and audience. The reason that these lead containing compounds are used as electric match compositions is that these mixtures have the required thermal stability, yet are simultaneously able to be initiated reliably by a very small thermal stimulus. A possible alternative to lead-containing compounds is nanoscale thermite materials (metastable intermolecular composites or MIC). These superthermite materials can be formulated to be extremely spark sensitive with tunable reaction rate and yield high temperature products. We have formulated and manufactured lead-free electric matches based on nanoscale Al/MoO{sub 3} mixtures. We have determined that these matches fire reliably and to consistently ignite a sample of black powder. Initial safety, ageing and performance results are presented in this paper.

  1. An Additive Manufacturing Test Artifact.

    PubMed

    Moylan, Shawn; Slotwinski, John; Cooke, April; Jurrens, Kevin; Donmez, M Alkan

    2014-01-01

    A test artifact, intended for standardization, is proposed for the purpose of evaluating the performance of additive manufacturing (AM) systems. A thorough analysis of previously proposed AM test artifacts as well as experience with machining test artifacts have inspired the design of the proposed test artifact. This new artifact is designed to provide a characterization of the capabilities and limitations of an AM system, as well as to allow system improvement by linking specific errors measured in the test artifact to specific sources in the AM system. The proposed test artifact has been built in multiple materials using multiple AM technologies. The results of several of the builds are discussed, demonstrating how the measurement results can be used to characterize and improve a specific AM system. PMID:26601039

  2. An Additive Manufacturing Test Artifact

    PubMed Central

    Moylan, Shawn; Slotwinski, John; Cooke, April; Jurrens, Kevin; Donmez, M Alkan

    2014-01-01

    A test artifact, intended for standardization, is proposed for the purpose of evaluating the performance of additive manufacturing (AM) systems. A thorough analysis of previously proposed AM test artifacts as well as experience with machining test artifacts have inspired the design of the proposed test artifact. This new artifact is designed to provide a characterization of the capabilities and limitations of an AM system, as well as to allow system improvement by linking specific errors measured in the test artifact to specific sources in the AM system. The proposed test artifact has been built in multiple materials using multiple AM technologies. The results of several of the builds are discussed, demonstrating how the measurement results can be used to characterize and improve a specific AM system. PMID:26601039

  3. An Additive Manufacturing Test Artifact.

    PubMed

    Moylan, Shawn; Slotwinski, John; Cooke, April; Jurrens, Kevin; Donmez, M Alkan

    2014-01-01

    A test artifact, intended for standardization, is proposed for the purpose of evaluating the performance of additive manufacturing (AM) systems. A thorough analysis of previously proposed AM test artifacts as well as experience with machining test artifacts have inspired the design of the proposed test artifact. This new artifact is designed to provide a characterization of the capabilities and limitations of an AM system, as well as to allow system improvement by linking specific errors measured in the test artifact to specific sources in the AM system. The proposed test artifact has been built in multiple materials using multiple AM technologies. The results of several of the builds are discussed, demonstrating how the measurement results can be used to characterize and improve a specific AM system.

  4. A novel addition polyimide adhesive

    NASA Technical Reports Server (NTRS)

    St.clair, T. L.; Progar, D. J.

    1981-01-01

    An addition polyimide adhesive, LARC 13, was developed which shows promise for bonding both titanium and composites for applications which require service temperatures in excess of 533 K. The LARC 13 is based on an oligomeric bis nadimide containing a meta linked aromatic diamine. The adhesive melts prior to polymerization due to its oligomeric nature, thereby allowing it to be processed at 344 kPa or less. Therefore, LARC 13 is ideal for the bonding of honeycomb sandwich structures. After melting, the resin thermosets during the cure of the nadic endcaps to a highly crosslinked system. Few volatiles are evolved, thus allowing large enclosed structures to be bonded. Preparation of the adhesive as well as bonding, aging, and testing of lap shear and honeycomb samples are discussed.

  5. Lead in the environment

    USGS Publications Warehouse

    Pattee, O.H.; Pain, D.J.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John=

    2003-01-01

    Anthropogenic uses of lead have probably altered its availability and environmental distribution more than any other toxic element. Consequently, lead concentrations in many living organisms may be approaching thresholds of toxicity for the adverse effects of lead. Such thresholds are difficult to define, as they vary with the chemical and physical form of lead, exposure regime, other elements present and also vary both within and between species. The technological capability to accurately quantify low lead concentrations has increased over the last decade, and physiological and behavioral effects have been measured in wildlife with tissue lead concentrations below those previously considered safe for humans.s.236 Consequently. lead criteria for the protection of wildlife and human health are frequently under review, and 'thresholds' of lead toxicity are being reconsidered. Proposed lead criteria for the protection of natural resources have been reviewed by Eisler. Uptake of lead by plants is limited by its generally low availability in soils and sediments, and toxicity may be limited by storage mechanisms and its apparently limited translocation within most plants. Lead does not generally accumulate within the foliar parts of plants, which limits its transfer to higher trophic levels. Although lead may concentrate in plant and animal tissues, no evidence of biomagnification exists. Acid deposition onto surface waters and soils with low buffering capacity may influence the availability of lead for uptake by plants and animals, and this may merit investigation at susceptible sites. The biological significance of chronic low-level lead exposure to wildlife is sometimes difficult to quantify. Animals living in urban environments or near point sources of lead emission are inevitably subject to greater exposure to lead and enhanced risk of lead poisoning. Increasingly strict controls on lead emissions in many countries have reduced exposure to lead from some sources

  6. Fiber optic communication links

    SciTech Connect

    Meyer, R. H.

    1980-01-01

    Fiber optics is a new, emerging technology which offers relief from many of the problems which limited past communications links. Its inherent noise immunity and high bandwidth open the door for new designs with greater capabilities. Being a new technology, certain problems can be encountered in specifying and installing a fiber optic link. A general fiber optic system is discussed with emphasis on the advantages and disadvantages. It is not intended to be technical in nature, but a general discussion. Finally, a general purpose prototype Sandia communications link is presented.

  7. Molecular Mechanics of Tip-Link Cadherins

    NASA Astrophysics Data System (ADS)

    Sotomayor, Marcos; Weihofen, Wilhelm A.; Gaudet, Rachelle; Corey, David P.

    2011-11-01

    The hair-cell tip link, a fine filament directly conveying force to mechanosensitive transduction channels, is likely composed of two proteins, protocadherin-15 and cadherin-23, whose mutation causes deafness. However, their complete molecular structure, elasticity, and deafness-related structural defects remain largely unknown. We present crystal structures of extracellular (EC) tip-link cadherin repeats involved in hereditary deafness and tip link formation. In addition, we show that the deafness mutation D101G, in the linker region between the repeats EC1 and EC2 of cadherin-23, causes a slight bend between repeats and decreases Ca2+ affinity. Molecular dynamics simulations suggest that tip-link cadherin repeats are stiff and that either removing Ca2+ or mutating Ca2+-binding residues reduces rigidity and unfolding strength. The structures and simulations also suggest mechanisms underlying inherited deafness and how cadherin-23 may bind with protocadherin-15 to form the tip link.

  8. Leading-edge receptivity for blunt-nose bodies

    NASA Technical Reports Server (NTRS)

    Kerschen, Edward J.

    1991-01-01

    This research program investigates boundary-layer receptivity in the leading-edge region for bodies with blunt leading edges. Receptivity theory provides the link between the unsteady distrubance environment in the free stream and the initial amplitudes of the instability waves in the boundary layer. This is a critical problem which must be addressed in order to develop more accurate prediction methods for boundary-layer transition. The first phase of this project examines the effects of leading-edge bluntness and aerodynamic loading for low Mach number flows. In the second phase of the project, the investigation is extended to supersonic Mach numbers. Singular perturbation techniques are utilized to develop an asymptotic theory for high Reynolds numbers. In the first year, the asymptotic theory was developed for leading-edge receptivity in low Mach number flows. The case of a parabolic nose is considered. Substantial progress was made on the Navier-Sotkes computations. Analytical solutions for the steady and unsteady potential flow fields were incorporated into the code, greatly expanding the types of free-stream disturbances that can be considered while also significantly reducing the the computational requirements. The time-stepping algorithm was modified so that the potential flow perturbations induced by the unsteady pressure field are directly introduced throughout the computational domain, avoiding an artificial 'numerical diffusion' of these from the outer boundary. In addition, the start-up process was modified by introducing the transient Stokes wave solution into the downstream boundary conditions.

  9. Pacing impedance variability in tined steroid eluting leads.

    PubMed

    Danilovic, D; Ohm, O J

    1998-07-01

    The aim of the study was to investigate pacing impedance (PI) behavior in ambulatory patients. Eighteen atrial and 18 ventricular tined steroid eluting leads with 1.2-mm2 and 5.6-mm2 electrodes were implanted in 20 patients. At 9-27 months after implantation PI was measured automatically by means of additional algorithms downloaded via telemetry links into implanted Thera pulse generators. PI was determined based on the voltage drop on the output capacitor during the 5 V-1 ms pacing impulse, at the programmable sampling rates from 1 second to 30 minutes. The study examined in particular: (1) PI trends and variations associated with different breathing patterns, body postures, provocative maneuvers, bike exercise, and during 24 hours; (2) impact of pacing rate and AV-delay on PI; (3) correlation between PI variability and pacing threshold, lead configuration, absolute PI value, age, gender, disease, and cardiac chamber. The most important findings were: (1) large PI variations of up to 450 omega were observed in properly functioning leads, (2) PI variability exhibited a weak negative correlation with pacing thresholds as if electrode positional stability was not a major factor underlying PI variations, (3) unipolar and bipolar PI variations were equivalent to each other (correlation factor = 0.93) implying that PI was mostly dependent on the circumstances around the lead tip.

  10. Pacing impedance variability in tined steroid eluting leads.

    PubMed

    Danilovic, D; Ohm, O J

    1998-07-01

    The aim of the study was to investigate pacing impedance (PI) behavior in ambulatory patients. Eighteen atrial and 18 ventricular tined steroid eluting leads with 1.2-mm2 and 5.6-mm2 electrodes were implanted in 20 patients. At 9-27 months after implantation PI was measured automatically by means of additional algorithms downloaded via telemetry links into implanted Thera pulse generators. PI was determined based on the voltage drop on the output capacitor during the 5 V-1 ms pacing impulse, at the programmable sampling rates from 1 second to 30 minutes. The study examined in particular: (1) PI trends and variations associated with different breathing patterns, body postures, provocative maneuvers, bike exercise, and during 24 hours; (2) impact of pacing rate and AV-delay on PI; (3) correlation between PI variability and pacing threshold, lead configuration, absolute PI value, age, gender, disease, and cardiac chamber. The most important findings were: (1) large PI variations of up to 450 omega were observed in properly functioning leads, (2) PI variability exhibited a weak negative correlation with pacing thresholds as if electrode positional stability was not a major factor underlying PI variations, (3) unipolar and bipolar PI variations were equivalent to each other (correlation factor = 0.93) implying that PI was mostly dependent on the circumstances around the lead tip. PMID:9670178

  11. Synthesis of triazole-linked morpholino oligonucleotides via CuI catalysed cycloaddition† †Electronic supplementary information (ESI) available: Full experimental details and copies of 1H, 13C, 31P NMR spectra for all compounds. See DOI: 10.1039/c6ob00007j Click here for additional data file.

    PubMed Central

    Palframan, Matthew J.; Alharthy, Rima D.; Powalowska, Paulina K.

    2016-01-01

    Triazole-linked morpholino (TLMO) oligonucleic acids were synthesised using the CuI catalysed (3 + 2) azide–alkyne cycloaddition (CuAAC) reaction. The modified DNA analogues were incorporated into 13-mer sequences via solid phase synthesis. UV melting experiments showed that the TLMO modification gives higher T m values than the corresponding TLDNA modification. PMID:26905296

  12. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Fletcher, James C. (Inventor); Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Stoakley, Diane M. (Inventor); Burks, Harold D. (Inventor)

    1992-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  13. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Stoakley, Diane M. (Inventor); Burks, Harold D. (Inventor)

    1993-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of the additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  14. A Simulation of X-Linked Inheritance.

    ERIC Educational Resources Information Center

    Harrell, Pamela Esprivalo

    1997-01-01

    Describes how to lead students through a classroom-based simulation to teach a variety of concepts such as X-linked traits, sex determination, and sex anomalies. The simulation utilizes inexpensive materials such as plastic eggs that twist apart to represent human eggs and sperm. (AIM)

  15. The NEC Link Scheme

    ERIC Educational Resources Information Center

    Noakes, Peter

    1976-01-01

    Describes the operation of the National Electronics Council (NEC) Link Scheme for schools in Great Britain. The service is intended to provide technical assistance, information concerning surplus equipment, and guest speakers for school aspiring professional electronic counsel. (CP)

  16. The Link: Business, Education.

    ERIC Educational Resources Information Center

    AGB Reports, 1984

    1984-01-01

    An excerpt from "Corporate and Campus Cooperation: An Action Agenda" (a report from the Business-Higher Education Forum) explains some methods for strengthening the link between the business and education communities. (Author/MLW)

  17. Linked for Learning.

    ERIC Educational Resources Information Center

    Freeman, Laurie

    1996-01-01

    The Northern Tier Distance Learning Consortium links six high schools and three colleges in northeastern Pennsylvania. Indiana students participated in an interactive distance-learning program that focused on underwater exploration. (MLF)

  18. Additional Types of Neuropathy

    MedlinePlus

    ... A A Listen En Español Additional Types of Neuropathy Charcot's Joint Charcot's Joint, also called neuropathic arthropathy, ... can stop bone destruction and aid healing. Cranial Neuropathy Cranial neuropathy affects the 12 pairs of nerves ...

  19. Food Additives and Hyperkinesis

    ERIC Educational Resources Information Center

    Wender, Ester H.

    1977-01-01

    The hypothesis that food additives are causally associated with hyperkinesis and learning disabilities in children is reviewed, and available data are summarized. Available from: American Medical Association 535 North Dearborn Street Chicago, Illinois 60610. (JG)

  20. Smog control fuel additives

    SciTech Connect

    Lundby, W.

    1993-06-29

    A method is described of controlling, reducing or eliminating, ozone and related smog resulting from photochemical reactions between ozone and automotive or industrial gases comprising the addition of iodine or compounds of iodine to hydrocarbon-base fuels prior to or during combustion in an amount of about 1 part iodine per 240 to 10,000,000 parts fuel, by weight, to be accomplished by: (a) the addition of these inhibitors during or after the refining or manufacturing process of liquid fuels; (b) the production of these inhibitors for addition into fuel tanks, such as automotive or industrial tanks; or (c) the addition of these inhibitors into combustion chambers of equipment utilizing solid fuels for the purpose of reducing ozone.

  1. External Link Policy | Division of Cancer Prevention

    Cancer.gov

    The following graphic notice means that you are leaving the DCP Web site: (link is external)This external link provides additional information that is consistent with the intended purpose of DCP.The National Cancer Institute (NCI) cannot attest to the accuracy of a non-federal site.Linking to a non-federal site does not constitute an endorsement by HHS or any of its employees of the sponsors or the information and products presented on the site.You will be subject to the destination site |

  2. Virtual screening for lead discovery.

    PubMed

    Tang, Yat T; Marshall, Garland R

    2011-01-01

    The identification of small drug-like compounds that selectively inhibit the function of biological targets has historically been a major focus in the pharmaceutical industry, and in recent years, has generated much interest in academia as well. Drug-like compounds are valuable as chemical genetics tools to probe biological pathways in a reversible, dose- and time-dependent manner for drug target identification. In addition, small molecule compounds can be used to characterize the shape and charge preferences of macromolecular binding sites, for both structure-based and ligand-based drug design. High-throughput screening is the most common experimental method used to identify lead compounds. Because of the cost, time, and resources required for performing high-throughput screening for compound libraries, the use of alternative strategies is necessary for facilitating lead discovery. Virtual screening has been successful in prioritizing large chemical libraries to identify experimentally active compounds, serving as a practical and effective alternative to high-throughput screening. Methodologies used in virtual screening such as molecular docking and scoring have advanced to the point where they can rapidly and accurately identify lead compounds in addition to predicting native binding conformations. This chapter provides instructions on how to perform a virtual screen using freely available tools for structure-based lead discovery. PMID:21318897

  3. Lead in drinking water and human blood lead levels in the United States.

    PubMed

    Brown, Mary Jean; Margolis, Stephen

    2012-08-10

    Lead is a pervasive environmental contaminant. The adverse health effects of lead exposure in children and adults are well documented, and no safe blood lead threshold in children has been identified. Lead can be ingested from various sources, including lead paint and house dust contaminated by lead paint, as well as soil, drinking water, and food. The concentration of lead, total amount of lead consumed, and duration of lead exposure influence the severity of health effects. Because lead accumulates in the body, all sources of lead should be controlled or eliminated to prevent childhood lead poisoning. Beginning in the 1970s, lead concentrations in air, tap water, food, dust, and soil began to be substantially reduced, resulting in significantly reduced blood lead levels (BLLs) in children throughout the United States. However, children are still being exposed to lead, and many of these children live in housing built before the 1978 ban on lead-based residential paint. These homes might contain lead paint hazards, as well as drinking water service lines made from lead, lead solder, or plumbing materials that contain lead. Adequate corrosion control reduces the leaching of lead plumbing components or solder into drinking water. The majority of public water utilities are in compliance with the Safe Drinking Water Act Lead and Copper Rule (LCR) of 1991. However, some children are still exposed to lead in drinking water. EPA is reviewing LCR, and additional changes to the rule are expected that will further protect public health. Childhood lead poisoning prevention programs should be made aware of the results of local public water system lead monitoring measurement under LCR and consider drinking water as a potential cause of increased BLLs, especially when other sources of lead exposure are not identified.

  4. Lead in drinking water and human blood lead levels in the United States.

    PubMed

    Brown, Mary Jean; Margolis, Stephen

    2012-08-10

    Lead is a pervasive environmental contaminant. The adverse health effects of lead exposure in children and adults are well documented, and no safe blood lead threshold in children has been identified. Lead can be ingested from various sources, including lead paint and house dust contaminated by lead paint, as well as soil, drinking water, and food. The concentration of lead, total amount of lead consumed, and duration of lead exposure influence the severity of health effects. Because lead accumulates in the body, all sources of lead should be controlled or eliminated to prevent childhood lead poisoning. Beginning in the 1970s, lead concentrations in air, tap water, food, dust, and soil began to be substantially reduced, resulting in significantly reduced blood lead levels (BLLs) in children throughout the United States. However, children are still being exposed to lead, and many of these children live in housing built before the 1978 ban on lead-based residential paint. These homes might contain lead paint hazards, as well as drinking water service lines made from lead, lead solder, or plumbing materials that contain lead. Adequate corrosion control reduces the leaching of lead plumbing components or solder into drinking water. The majority of public water utilities are in compliance with the Safe Drinking Water Act Lead and Copper Rule (LCR) of 1991. However, some children are still exposed to lead in drinking water. EPA is reviewing LCR, and additional changes to the rule are expected that will further protect public health. Childhood lead poisoning prevention programs should be made aware of the results of local public water system lead monitoring measurement under LCR and consider drinking water as a potential cause of increased BLLs, especially when other sources of lead exposure are not identified. PMID:22874873

  5. DECISION-MAKING, SCIENCE AND GASOLINE ADDITIVES

    EPA Science Inventory


    Methyl-tert butyl ether (MTBE) has been used as a gasoline additive to serve two major purposes. The first use was as an octane-enhancer to replace organic lead, beginning in 1979. The second use, which began about 1992, was as an oxygenated additive to meet requirements ...

  6. Lead Poison Detection

    NASA Technical Reports Server (NTRS)

    1976-01-01

    With NASA contracts, Whittaker Corporations Space Science division has developed an electro-optical instrument to mass screen for lead poisoning. Device is portable and detects protoporphyrin in whole blood. Free corpuscular porphyrins occur as an early effect of lead ingestion. Also detects lead in urine used to confirm blood tests. Test is inexpensive and can be applied by relatively unskilled personnel. Similar Whittaker fluorometry device called "drug screen" can measure morphine and quinine in urine much faster and cheaper than other methods.

  7. Kinetics of oil saponification by lead salts in ancient preparations of pharmaceutical lead plasters and painting lead mediums.

    PubMed

    Cotte, M; Checroun, E; Susini, J; Dumas, P; Tchoreloff, P; Besnard, M; Walter, Ph

    2006-12-15

    Lead soaps can be found in archaeological cosmetics as well as in oil paintings, as product of interactions of lead salts with oil. In this context, a better understanding of the formation of lead soaps allows a follow-up of the historical evolution of preparation recipes and provides new insights into conservation conditions. First, ancient recipes of both pharmaceutical lead plasters and painting lead mediums, mixtures of oil and lead salts, were reconstructed. The ester saponification by lead salts is determined by the preparation parameters which were quantified by FT-IR spectrometry. In particular, ATR/FT-IR spectrometer was calibrated by the standard addition method to quantitatively follow the kinetics of this reaction. The influence of different parameters such as temperature, presence of water and choice of lead salts was assessed: the saponification is clearly accelerated by water and heating. This analysis provides chemical explanations to the historical evolution of cosmetic and painting preparation recipes.

  8. Lead and growth.

    PubMed

    Kaji, Masayuki; Nishi, Yoshikazu

    2006-01-01

    Lead is highly toxic to the human body and children are much more vulnerable to lead toxicity than adults. Many studies have revealed that relatively low levels of blood lead can adversely affect human health, especially childhood growth and development. Blood lead levels (BLL) of children and adults have been decreasing recently almost all over the world, but a safety level for blood lead does not exist, and lead exposure is still a serious health problem especially for fetuses and children. Maternal lead burden causes fetal lead exposure and increases the risk of abortions, prematurity, low birth weight, and some minor anomalies. Infant BLL are inversely associated with weight gain. A negative relationship between somatic growth and BLL in children has been revealed. It has been suggested that lead exposure causes decrease of gonadotropin secretion of adolescents and delay of pubertal development. Several studies have revealed that children who are exposed to cigarette smoke have higher BLL than children who are not. Children should be protected from cigarette smoke for the purpose of avoiding the risk of increased BLL which might adversely affect their intellectual development and physical growth.

  9. Toxicological properties of lead.

    PubMed Central

    Damstra, T

    1977-01-01

    The pathological effects of lead on the renal, nervous, reproductive, endocrine, and immune systems have been reviewed. Emphasis is placed on reported subclinical effects due to chronic, low-level lead exposure. The crucial issue of whether subtle behavioral, intellectual, and developmental impairment occurs in young children, as a result of lead-induced CNS damage is discussed in detail. This issue remains unresolved. Further studies are needed in order to determine the long-term health effects of continuous, low-level lead exposure. PMID:198205

  10. Acute lead arsenate poisoning.

    PubMed

    Tallis, G A

    1989-12-01

    Three cases of acute lead arsenate poisoning which occurred in South Australia during a 12 month interval are described. The case reports demonstrate a number of features of the characteristic clinical syndrome which may follow ingestion of lead arsenate. The recommended management is immediate gastric lavage and subsequent chelation therapy with calcium EDTA and dimercaprol. Early gastric lavage may prevent significant lead absorption. However, arsenic acid (produced in the stomach when lead arsenate reacts with hydrochloric acid) is relatively water soluble and prompt gastric lavage is unlikely to prevent extensive arsenic absorption. It remains controversial as to whether chelation with dimercaprol prevents arsenical neuropathy.

  11. Lead poisoning: case studies

    PubMed Central

    Gordon, J N; Taylor, A; Bennett, P N

    2002-01-01

    Early clinical features of lead toxicity are non-specific and an occupational history is particularly valuable. Lead in the body comprises 2% in the blood (t1/2 35 days) and 95% in bone and dentine (t1/2 20–30 years). Blood lead may remain elevated for years after cessation from long exposure, due to redistribution from bone. Blood lead concentration is the most widely used marker for inorganic lead exposure. Zinc protoporphyrin (ZPP) concentration in blood usefully reflects lead exposure over the prior 3 months. Symptomatic patients with blood lead concentration >2.4 µmol l−1 (50 µg dl−1) or in any event >3.8 µmol l−1 (80 µg dl−1) should receive sodium calciumedetate i.v., followed by succimer by mouth for 19 days. Asymptomatic patients with blood lead concentration >2.4 µmol l−1 (50 µg dl−1) may be treated with succimer alone. Sodium calciumedetate should be given with dimercaprol to treat lead encephalopathy. PMID:11994050

  12. Linked Ocean Data

    NASA Astrophysics Data System (ADS)

    Leadbetter, Adam; Arko, Robert; Chandler, Cynthia; Shepherd, Adam

    2014-05-01

    "Linked Data" is a term used in Computer Science to encapsulate a methodology for publishing data and metadata in a structured format so that links may be created and exploited between objects. Berners-Lee (2006) outlines the following four design principles of a Linked Data system: Use Uniform Resource Identifiers (URIs) as names for things. Use HyperText Transfer Protocol (HTTP) URIs so that people can look up those names. When someone looks up a URI, provide useful information, using the standards (Resource Description Framework [RDF] and the RDF query language [SPARQL]). Include links to other URIs so that they can discover more things. In 2010, Berners-Lee revisited his original design plan for Linked Data to encourage data owners along a path to "good Linked Data". This revision involved the creation of a five star rating system for Linked Data outlined below. One star: Available on the web (in any format). Two stars: Available as machine-readable structured data (e.g. An Excel spreadsheet instead of an image scan of a table). Three stars: As two stars plus the use of a non-proprietary format (e.g. Comma Separated Values instead of Excel). Four stars: As three stars plus the use of open standards from the World Wide Web Commission (W3C) (i.e. RDF and SPARQL) to identify things, so that people can point to your data and metadata. Five stars: All the above plus link your data to other people's data to provide context Here we present work building on the SeaDataNet common vocabularies served by the NERC Vocabulary Server, connecting projects such as the Rolling Deck to Repository (R2R) and the Biological and Chemical Oceanography Data Management Office (BCO-DMO) and other vocabularies such as the Marine Metadata Interoperability Ontology Register and Repository and the NASA Global Change Master Directory to create a Linked Ocean Data cloud. Publishing the vocabularies and metadata in standard RDF XML and exposing SPARQL endpoints renders them five-star Linked

  13. Additive Manufacturing Infrared Inspection

    NASA Technical Reports Server (NTRS)

    Gaddy, Darrell

    2014-01-01

    Additive manufacturing is a rapid prototyping technology that allows parts to be built in a series of thin layers from plastic, ceramics, and metallics. Metallic additive manufacturing is an emerging form of rapid prototyping that allows complex structures to be built using various metallic powders. Significant time and cost savings have also been observed using the metallic additive manufacturing compared with traditional techniques. Development of the metallic additive manufacturing technology has advanced significantly over the last decade, although many of the techniques to inspect parts made from these processes have not advanced significantly or have limitations. Several external geometry inspection techniques exist such as Coordinate Measurement Machines (CMM), Laser Scanners, Structured Light Scanning Systems, or even traditional calipers and gages. All of the aforementioned techniques are limited to external geometry and contours or must use a contact probe to inspect limited internal dimensions. This presentation will document the development of a process for real-time dimensional inspection technique and digital quality record of the additive manufacturing process using Infrared camera imaging and processing techniques.

  14. Lead extraction. Indications and techniques.

    PubMed

    Byrd, C L; Schwartz, S J; Hedin, N

    1992-11-01

    Each of the extraction techniques and their ancillary tools was reported as used successfully; however, until now, no technique has been successful when used in more than a few isolated instances. The technique for intravascular countertraction and the associated tools described in this paper were devised and selected in an attempt to develop one technique to be used on all patients, with all types of leads, and with a very low complication rate. Its versatility permitted single or multiple lead extractions combined with the precision of selecting and extracting a specific lead. In our experience, as well as the experience of others, the techniques described in this paper have proved to be superior by minimizing the inherent risk and morbidity, allowing us to expand the indications for lead removal beyond septicemia and free-floating leads, to include infection, abandonment of pockets, and replacement of malfunctioning or fractured leads. Intravascular countertraction was a consistently safe and efficacious method of removing transvenous pacemaker leads regardless of the duration of the implant, thus permitting extractions in patients not considered candidates for a more extensive surgical procedure. Intravascular countertraction encompasses surgical and fluoroscopic techniques possessed by most physicians experienced in pacemaker and automatic implantable cardioverter defibrillator implants. However, there is a learning curve, predicating caution for the inexperienced physician. In addition, advanced surgical skills may be needed in handling associated conditions such as debridement and primary closure of chronically inflamed tissues, especially in submuscular pockets and sinus tracts in the neck. Although the potential for a cardiovascular complication is small, it does exist, and cardiovascular surgical backup is a recommended precaution.

  15. Publishing Data on Physical Samples Using the GeoLink Ontology and Linked Data Platforms

    NASA Astrophysics Data System (ADS)

    Ji, P.; Arko, R. A.; Lehnert, K. A.; Song, L.; Carter, M. R.; Hsu, L.

    2015-12-01

    Interdisciplinary Earth Data Alliance (IEDA), one of partners in EarthCube GeoLink project, seeks to explore the extent to which the use of GeoLink reusable Ontology Design Patterns (ODPs) and linked data platforms in IEDA data infrastructure can make research data more easily accessible and valuable. Linked data for the System for Earth Sample Registration (SESAR) is the first effort of IEDA to show how linked data enhance the presentation of IEDA data system architecture. SESAR Linked Data maps each table and column in SESAR database to RDF class and property based on GeoLink view, which build on the top of GeoLink ODPs. Then, uses D2RQ dumping the contents of SESAR database into RDF triples on the basis of mapping results. And, the dumped RDF triples is loaded into GRAPHDB, an RDF graph database, as permanent data in the form of atomic facts expressed as subjects, predicates and objects which provide support for semantic interoperability between IEDA and other GeoLink partners. Finally, an integrated browsing and searching interface build on Callimachus, a highly scalable platform for publishing linked data, is introduced to make sense of data stored in triplestore. Drill down and through features are built in the interface to help users locating content efficiently. The drill down feature enables users to explore beyond the summary information in the instance list of a specific class and into the detail from the specific instance page. The drill through feature enables users to jump from one instance to another one by simply clicking the link of the latter nested in the former region. Additionally, OpenLayers map is embedded into the interface to enhance the attractiveness of the presentation of instance which has geospatial information. Furthermore, by linking instances in the SESAR datasets to matching or corresponding instances in external sets, the presentation has been enriched with additional information about related classes like person, cruise, etc.

  16. Phenylethynyl Containing Reactive Additives

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

    2002-01-01

    Phenylethynyl containing reactive additives were prepared from aromatic diamine, containing phenylethvnvl groups and various ratios of phthalic anhydride and 4-phenylethynviphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pvrrolidinone to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.

  17. Recovering lead from batteries

    NASA Astrophysics Data System (ADS)

    David Prengaman, R.

    1995-01-01

    Over the past 20 years, a significant number of processes have been developed to recover lead from scrap batteries. These processes recover lead via hydrometallurgical processing of the paste component of the battery followed by electrowinning. A number of pilot plant operations have been conducted, but thus far none of the processes have become operational.

  18. Leadership, Leaders, and Leading

    ERIC Educational Resources Information Center

    Dean, Peter J.

    2004-01-01

    Arguably, the most important need in society today is to create individuals who will take action positively and progressively to lead in the private organization, in the the public institution, or in the governmental agency. Leadership action should not be held hostage by the notion that only those in formal positions of leadership can lead.…

  19. Rapid Lead Screening Test

    MedlinePlus

    ... and treated earlier before the damaging effects of lead poisoning occur. U.S. Department of Health and Human Services ... exceed 10μg/dL, the threshold used to indicate lead poisoning. The American Academy of Pediatrics (AAP) estimates one ...

  20. Lead Poisoning in Children.

    ERIC Educational Resources Information Center

    Lin-Fu, Jane S.

    This publication is a guide to help social and health workers plan a preventive campaign against lead poisoning, a cause of mental retardation other neurological handicaps, and death among children. The main victims are 1- to 6-year-olds living in areas where deteriorating housing prevails. Among the causes of lead poisoning are: ingestion of…

  1. Supersonic Leading Edge Receptivity

    NASA Technical Reports Server (NTRS)

    Maslov, Anatoly A.

    1998-01-01

    This paper describes experimental studies of leading edge boundary layer receptivity for imposed stream disturbances. Studies were conducted in the supersonic T-325 facility at ITAM and include data for both sharp and blunt leading edges. The data are in agreement with existing theory and should provide guidance for the development of more complete theories and numerical computations of this phenomena.

  2. Lead toxicity: a review

    PubMed Central

    Ara, Anjum; Usmani, Jawed Ahmad

    2015-01-01

    Lead toxicity is an important environmental disease and its effects on the human body are devastating. There is almost no function in the human body which is not affected by lead toxicity. Though in countries like US and Canada the use of lead has been controlled up to a certain extent, it is still used vehemently in the developing countries. This is primarily because lead bears unique physical and chemical properties that make it suitable for a large number of applications for which humans have exploited its benefits from historical times and thus it has become a common environmental pollutant. Lead is highly persistent in the environment and because of its continuous use its levels rise in almost every country, posing serious threats. This article reviews the works listed in the literature with recent updates regarding the toxicity of lead. Focus is also on toxic effects of lead on the renal, reproductive and nervous system. Finally the techniques available for treating lead toxicity are presented with some recent updates. PMID:27486361

  3. Lead carbonate scintillator materials

    DOEpatents

    Derenzo, Stephen E.; Moses, William W.

    1991-01-01

    Improved radiation detectors containing lead carbonate or basic lead carbonate as the scintillator element are disclosed. Both of these scintillators have been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to other known scintillator materials. The radiation detectors disclosed are favorably suited for use in general purpose detection and in medical uses.

  4. LEAD IN CANDLE EMISSIONS

    EPA Science Inventory

    The candle-using public should be made aware that the core of candle wicks may contain lead. Used as a stiffening agent to keep the wick out of the molten wax, lead can be emitted as particulate to the air and then deposited on indoor surfaces. To define the problem, 100 sets of ...

  5. Lead-contaminated house dust and urban children's blood lead levels.

    PubMed Central

    Lanphear, B P; Weitzman, M; Winter, N L; Eberly, S; Yakir, B; Tanner, M; Emond, M; Matte, T D

    1996-01-01

    OBJECTIVES: This study assessed the relationship between lead-contaminated house dust and urban children's blood lead levels. METHODS: A random-sample survey was used to identify and enroll 205 children, 12 to 31 months of age, who had resided in the same house since at least 6 months of age. Children's blood and household dust, water, soil, and paint were analyzed for lead, and interviews were conducted to ascertain risk factors for elevated blood lead (> or = 10 micrograms/dL). RESULTS: Children's mean blood lead level was 7.7 micrograms/dL. In addition to dust lead loading (micrograms of lead per square foot), independent predictors of children's blood lead were Black race, soil lead levels, ingestion of soil or dirt, lead content and condition of painted surfaces, and water lead levels. For dust lead standards of 5 micrograms/sq ft, 20 micrograms/sq ft, and 40 micrograms/sq ft on noncarpeted floors, the estimated percentages of children having blood lead levels at or above 10 micrograms/dL were 4%, 15%, and 20%, respectively, after adjusting for other significant covariates. CONCLUSIONS: Lead-contaminated house dust is a significant contributor to lead intake among urban children who have low-level elevations in blood lead. A substantial proportion of children may have blood lead levels of at least 10 micrograms/dL at dust lead levels considerably lower than current standards. PMID:8876511

  6. Lead polluters get punished

    SciTech Connect

    Not Available

    1991-08-09

    The Environmental Protection Agency (EPA) and the Department of Justice last week cracked down on 36 US companies for polluting the environment with lead. EPA slapped fines totaling more than $10 million on 12 of the offending companies, and Justice filed 24 civil complaints. Hank Habicht, deputy administrator of the EPA, said that his agency's initiative comes after 8 months of intense - and presumably successful - efforts at locating and documenting lead pollution in the soil, air, and water supply. Most feared has been lead's ability to damage the intellectual development of children. This caused the agency, Habicht said, to look beyond the usual suspect - lead in the water supply - to lead-laced dirt in residential areas. Meanwhile, the Department of Justice is using the EPA contamination data as well. Twenty US attorneys have been assigned to pore over the federal environmental statutes, including the Clean Water Act and the Superfund Law, in order to file civil complaints.

  7. Lead toxicity: current concerns.

    PubMed Central

    Goyer, R A

    1993-01-01

    Over the 20-year period since the first issue of Environmental Health Perspectives was published, there has been considerable progress in the understanding of the potential toxicity of exposure to lead. Many of these advances have been reviewed in published symposia, conferences, and review papers in EHP. This brief review identifies major advances as well as a number of current concerns that present opportunities for prevention and intervention strategies. The major scientific advance has been the demonstration that blood lead (PbB) levels of 10-15 micrograms/dL in newborn and very young infants result in cognitive and behavioral deficits. Further support for this observation is being obtained by prospective or longitudinal studies presently in progress. The mechanism(s) for the central nervous system effects of lead is unclear but involve lead interactions within calcium-mediated intracellular messenger systems and neurotransmission. Effects of low-level lead exposure on blood pressure, particularly in adult men, may be related to the effect of lead on calcium-mediated control of vascular smooth muscle contraction and on the renin-angiotensin system. Reproductive effects of lead have long been suspected, but low-level effects have not been well studied. Whether lead is a carcinogen or its association with renal adenocarcinoma is a consequence of cystic nephropathy is uncertain. Major risk factors for lead toxicity in children in the United States include nutrition, particularly deficiencies of essential metals, calcium, iron, and zinc, and housing and socioeconomic status. A goal for the year 2000 is to reduce prevalence of blood lead levels exceeding 15 micrograms/dL. Images FIGURE 2. PMID:8354166

  8. Lead toxicity: Current concerns

    SciTech Connect

    Goyer, R.A. )

    1993-04-01

    Over the 20-year period since the first issue of Environmental Health Perspectives was published, there has been considerable progress in the understanding of the potential toxicity of exposure to lead. Many of these advances have been reviewed in published symposia, conferences, and review papers in EHP. This brief review identifies major advances as well as a number of current concerns that present opportunities for prevention and intervention strategies. The major scientific advance has been the demonstration that blood lead (PbB) levels of 10-15 micrograms/dL in newborn and very young infants result in cognitive and behavioral deficits. Further support for this observation is being obtained by prospective or longitudinal studies presently in progress. The mechanism(s) for the central nervous system effects of lead is unclear but involve lead interactions within calcium-mediated intracellular messenger systems and neurotransmission. Effects of low-level lead exposure on blood pressure, particularly in adult men, may be related to the effect of lead on calcium-mediated control of vascular smooth muscle contraction and on the renin-angiotensin system. Reproductive effects of lead have long been suspected, but low-level effects have not been well studied. Whether lead is a carcinogen or its association with renal adenocarcinoma is a consequence of cystic nephropathy is uncertain. Major risk factors for lead toxicity in children in the United States include nutrition, particularly deficiencies of essential metals, calcium, iron, and zinc, and housing and socioeconomic status. A goal for the year 2000 is to reduce prevalence of blood lead levels exceeding 15 micrograms/dL. 97 refs.

  9. Leading to distraction: Driver distraction, lead car, and road environment.

    PubMed

    Kountouriotis, G K; Merat, N

    2016-04-01

    Driver distraction is strongly associated with crashes and near-misses, and despite the attention this topic has received in recent years, the effect of different types of distracting task on driving performance remains unclear. In the case of non-visual distractions, such as talking on the phone or other engaging verbal tasks that do not require a visual input, a common finding is reduced lateral variability in steering and gaze patterns where participants concentrate their gaze towards the centre of the road and their steering control is less variable. In the experiments presented here, we examined whether this finding is more pronounced in the presence of a lead car (which may provide a focus point for gaze) and whether the behaviour of the lead car has any influence on the driver's steering control. In addition, both visual and non-visual distraction tasks were used, and their effect on different road environments (straight and curved roadways) was assessed. Visual distraction was found to increase variability in both gaze patterns and steering control, non-visual distraction reduced gaze and steering variability in conditions without a lead car; in the conditions where a lead car was present there was no significant difference from baseline. The lateral behaviour of the lead car did not have an effect on steering performance, a finding which indicates that a lead car may not necessarily be used as an information point. Finally, the effects of driver distraction were different for straight and curved roadways, indicating a stronger influence of the road environment in steering than previously thought. PMID:26785327

  10. Leading to distraction: Driver distraction, lead car, and road environment.

    PubMed

    Kountouriotis, G K; Merat, N

    2016-04-01

    Driver distraction is strongly associated with crashes and near-misses, and despite the attention this topic has received in recent years, the effect of different types of distracting task on driving performance remains unclear. In the case of non-visual distractions, such as talking on the phone or other engaging verbal tasks that do not require a visual input, a common finding is reduced lateral variability in steering and gaze patterns where participants concentrate their gaze towards the centre of the road and their steering control is less variable. In the experiments presented here, we examined whether this finding is more pronounced in the presence of a lead car (which may provide a focus point for gaze) and whether the behaviour of the lead car has any influence on the driver's steering control. In addition, both visual and non-visual distraction tasks were used, and their effect on different road environments (straight and curved roadways) was assessed. Visual distraction was found to increase variability in both gaze patterns and steering control, non-visual distraction reduced gaze and steering variability in conditions without a lead car; in the conditions where a lead car was present there was no significant difference from baseline. The lateral behaviour of the lead car did not have an effect on steering performance, a finding which indicates that a lead car may not necessarily be used as an information point. Finally, the effects of driver distraction were different for straight and curved roadways, indicating a stronger influence of the road environment in steering than previously thought.

  11. Multifunctional fuel additives

    SciTech Connect

    Baillargeon, D.J.; Cardis, A.B.; Heck, D.B.

    1991-03-26

    This paper discusses a composition comprising a major amount of a liquid hydrocarbyl fuel and a minor low-temperature flow properties improving amount of an additive product of the reaction of a suitable diol and product of a benzophenone tetracarboxylic dianhydride and a long-chain hydrocarbyl aminoalcohol.

  12. Biobased lubricant additives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fully biobased lubricants are those formulated using all biobased ingredients, i.e. biobased base oils and biobased additives. Such formulations provide the maximum environmental, safety, and economic benefits expected from a biobased product. Currently, there are a number of biobased base oils that...

  13. Lead-free piezoceramics

    NASA Astrophysics Data System (ADS)

    Saito, Yasuyoshi; Takao, Hisaaki; Tani, Toshihiko; Nonoyama, Tatsuhiko; Takatori, Kazumasa; Homma, Takahiko; Nagaya, Toshiatsu; Nakamura, Masaya

    2004-11-01

    Lead has recently been expelled from many commercial applications and materials (for example, from solder, glass and pottery glaze) owing to concerns regarding its toxicity. Lead zirconium titanate (PZT) ceramics are high-performance piezoelectric materials, which are widely used in sensors, actuators and other electronic devices; they contain more than 60 weight per cent lead. Although there has been a concerted effort to develop lead-free piezoelectric ceramics, no effective alternative to PZT has yet been found. Here we report a lead-free piezoelectric ceramic with an electric-field-induced strain comparable to typical actuator-grade PZT. We achieved this through the combination of the discovery of a morphotropic phase boundary in an alkaline niobate-based perovskite solid solution, and the development of a processing route leading to highly <001> textured polycrystals. The ceramic exhibits a piezoelectric constant d33 (the induced charge per unit force applied in the same direction) of above 300picocoulombs per newton (pCN-1), and texturing the material leads to a peak d33 of 416pCN-1. The textured material also exhibits temperature-independent field-induced strain characteristics.

  14. Conditioned reinforcement dynamics in three-link chained schedules.

    PubMed

    Williams, B A

    1997-01-01

    In two experiments rats were trained on three-link concurrent-chains schedules of reinforcement. In Experiment 1, additional entries to one terminal link were added during one of the middle links to a baseline schedule that was otherwise equal for the two chains, and, depending on the condition, these additional terminal-link presentations ended either in food or in no food. When food occurred, preference was always in favor of the chain with the additional terminal-link presentations (which also entailed a higher rate of reinforcement). When no food occurred at the end of the additional terminal links, the outcome depended on the nature of the stimuli associated with these additional terminal links. When stimuli different from the reinforced baseline terminal links were used for the no-food terminal links, preference was against the choice alternative that led to the extra periods of extinction. When the same stimulus was used for the two kinds of terminal links, preference was near indifference, that is, significantly greater than when different stimuli were used. In Experiment 2, rats learned repeated reversals of a simultaneous discrimination under a three-link concurrent-chains schedule, in which the food or no-food choice outcomes were delayed until the end of the chain. Different conditions were defined by the point in the chain at which differential stimuli occurred. When the middle and terminal links provided no differential stimuli, discrimination was acquired more slowly than when differential stimuli occurred in both links. When differential stimuli occurred in the middle but not the terminal links, acquisition rates were intermediate. Both experiments together show that the effects of stimuli in a chain schedule are due partly to the time to food correlated with the stimuli and partly to the time to the next conditioned reinforcer in the sequence.

  15. Fast Randomized STDMA Link Scheduling

    NASA Astrophysics Data System (ADS)

    Gomez, Sergio; Gras, Oriol; Friderikos, Vasilis

    In this paper a fast randomized parallel link swap based packing (RSP) algorithm for timeslot allocation in a spatial time division multiple access (STDMA) wireless mesh network is presented. The proposed randomized algorithm extends several greedy scheduling algorithms that utilize the physical interference model by applying a local search that leads to a substantial improvement in the spatial timeslot reuse. Numerical simulations reveal that compared to previously scheduling schemes the proposed randomized algorithm can achieve a performance gain of up to 11%. A significant benefit of the proposed scheme is that the computations can be parallelized and therefore can efficiently utilize commoditized and emerging multi-core and/or multi-CPU processors.

  16. Missing and forbidden links in mutualistic networks.

    PubMed

    Olesen, Jens M; Bascompte, Jordi; Dupont, Yoko L; Elberling, Heidi; Rasmussen, Claus; Jordano, Pedro

    2011-03-01

    Ecological networks are complexes of interacting species, but not all potential links among species are realized. Unobserved links are either missing or forbidden. Missing links exist, but require more sampling or alternative ways of detection to be verified. Forbidden links remain unobservable, irrespective of sampling effort. They are caused by linkage constraints. We studied one Arctic pollination network and two Mediterranean seed-dispersal networks. In the first, for example, we recorded flower-visit links for one full season, arranged data in an interaction matrix and got a connectance C of 15 per cent. Interaction accumulation curves documented our sampling of interactions through observation of visits to be robust. Then, we included data on pollen from the body surface of flower visitors as an additional link 'currency'. This resulted in 98 new links, missing from the visitation data. Thus, the combined visit-pollen matrix got an increased C of 20 per cent. For the three networks, C ranged from 20 to 52 per cent, and thus the percentage of unobserved links (100 - C) was 48 to 80 per cent; these were assumed forbidden because of linkage constraints and not missing because of under-sampling. Phenological uncoupling (i.e. non-overlapping phenophases between interacting mutualists) is one kind of constraint, and it explained 22 to 28 per cent of all possible, but unobserved links. Increasing phenophase overlap between species increased link probability, but extensive overlaps were required to achieve a high probability. Other kinds of constraint, such as size mismatch and accessibility limitations, are briefly addressed.

  17. Fire-Retardant Polymeric Additives

    NASA Technical Reports Server (NTRS)

    Williams, Martha K.; Smith, Trent M.

    2011-01-01

    Polyhydroxyamide (PHA) and polymethoxyamide (PMeOA) are fire-retardant (FR) thermoplastic polymers and have been found to be useful as an additive for imparting fire retardant properties to other compatible, thermoplastic polymers (including some elastomers). Examples of compatible flammable polymers include nylons, polyesters, and acrylics. Unlike most prior additives, PHA and PMeOA do not appreciably degrade the mechanical properties of the matrix polymer; indeed, in some cases, mechanical properties are enhanced. Also, unlike some prior additives, PHA and PMeOA do not decompose into large amounts of corrosive or toxic compounds during combustion and can be processed at elevated temperatures. PMeOA derivative formulations were synthesized and used as an FR additive in the fabrication of polyamide (PA) and polystyrene (PS) composites with notable reduction (>30 percent for PS) in peak heat release rates compared to the neat polymer as measured by a Cone Calorimeter (ASTM E1354). Synergistic effects were noted with nanosilica composites. These nanosilica composites had more than 50-percent reduction in peak heat release rates. In a typical application, a flammable thermoplastic, thermoplastic blend, or elastomer that one seeks to render flame-retardant is first dry-mixed with PHA or PMeOA or derivative thereof. The proportion of PHA or PMeOA or derivative in the mixture is typically chosen to lie between 1 and 20 weight percent. The dry blend can then be melt-extruded. The extruded polymer blend can further be extruded and/or molded into fibers, pipes, or any other of a variety of objects that may be required to be fire-retardant. The physical and chemical mechanisms which impart flame retardancy of the additive include inhibiting free-radical oxidation in the vapor phase, preventing vaporization of fuel (the polymer), and cooling through the formation of chemical bonds in either the vapor or the condensed phase. Under thermal stress, the cyclic hydroxyl/ methoxy

  18. Lead and Copper Control 101-slides

    EPA Science Inventory

    This presentation is an overview of the most important water treatment strategies for the control of lead and copper release from drinking water corrosion. In addition to the sections specifically on lead and copper treatment, sections are included that cover sampling to find le...

  19. Vinyl capped addition polyimides

    NASA Technical Reports Server (NTRS)

    Vannucci, Raymond D. (Inventor); Malarik, Diane C. (Inventor); Delvigs, Peter (Inventor)

    1991-01-01

    Polyimide resins (PMR) are generally useful where high strength and temperature capabilities are required (at temperatures up to about 700 F). Polyimide resins are particularly useful in applications such as jet engine compressor components, for example, blades, vanes, air seals, air splitters, and engine casing parts. Aromatic vinyl capped addition polyimides are obtained by reacting a diamine, an ester of tetracarboxylic acid, and an aromatic vinyl compound. Low void materials with improved oxidative stability when exposed to 700 F air may be fabricated as fiber reinforced high molecular weight capped polyimide composites. The aromatic vinyl capped polyimides are provided with a more aromatic nature and are more thermally stable than highly aliphatic, norbornenyl-type end-capped polyimides employed in PMR resins. The substitution of aromatic vinyl end-caps for norbornenyl end-caps in addition polyimides results in polymers with improved oxidative stability.

  20. Tackifier for addition polyimides

    NASA Technical Reports Server (NTRS)

    Butler, J. M.; St.clair, T. L.

    1980-01-01

    A modification to the addition polyimide, LaRC-160, was prepared to improve tack and drape and increase prepeg out-time. The essentially solventless, high viscosity laminating resin is synthesized from low cost liquid monomers. The modified version takes advantage of a reactive, liquid plasticizer which is used in place of solvent and helps solve a major problem of maintaining good prepeg tack and drape, or the ability of the prepeg to adhere to adjacent plies and conform to a desired shape during the lay up process. This alternate solventless approach allows both longer life of the polymer prepeg and the processing of low void laminates. This approach appears to be applicable to all addition polyimide systems.

  1. Electrophilic addition of astatine

    SciTech Connect

    Norseev, Yu.V.; Vasaros, L.; Nhan, D.D.; Huan, N.K.

    1988-03-01

    It has been shown for the first time that astatine is capable of undergoing addition reactions to unsaturated hydrocarbons. A new compound of astatine, viz., ethylene astatohydrin, has been obtained, and its retention numbers of squalane, Apiezon, and tricresyl phosphate have been found. The influence of various factors on the formation of ethylene astatohydrin has been studied. It has been concluded on the basis of the results obtained that the univalent cations of astatine in an acidic medium is protonated hypoastatous acid.

  2. Scientists Zero in On Brain Area Linked to 'Parkinson's Gait'

    MedlinePlus

    ... Scientists Zero in on Brain Area Linked to 'Parkinson's Gait' Discovery could lead to new treatments for ... play a role in walking difficulties that afflict Parkinson's disease patients, new research suggests. The prefrontal cortex ...

  3. Does eczema lead to asthma?

    PubMed

    Burgess, John A; Lowe, Adrian J; Matheson, Melanie C; Varigos, George; Abramson, Michael J; Dharmage, Shyamali C

    2009-06-01

    The nature of the relationship between eczema, asthma, and allergic rhinitis has been controversial. It has been commonly held that these disorders, while sharing genetic and environmental risk factors, are unrelated disorders that may develop sequentially along an atopic pathway. Conversely, the link between eczema and these later-onset respiratory disorders may be causal. This review examines the relationship between eczema, asthma, and allergic rhinitis in the context of the atopic march, the skin barrier, and recent developments in eczema genetics; and we propose that the relationship is causal. We describe a plausible biological pathway with eczema as the first step in a progressive atopic march that over time leads to asthma and/or allergic rhinitis. Such a pathway has implications for our understanding of these disorders and steps that might be made to prevent the development of asthma in particular. We propose that intervention studies in eczema should be conducted to confirm or refute this causal relationship. Such studies may materially improve the quality of life of eczema patients and will have important public health benefits if the interventions lead to a reduction in the burden of asthma.

  4. Lead acetate trihydrate precursor route to synthesize novel ultrafine lead oxide from spent lead acid battery pastes

    NASA Astrophysics Data System (ADS)

    Sun, Xiaojuan; Yang, Jiakuan; Zhang, Wei; Zhu, Xinfeng; Hu, Yuchen; Yang, Danni; Yuan, Xiqing; Yu, Wenhao; Dong, Jinxin; Wang, Haifeng; Li, Lei; Vasant Kumar, R.; Liang, Sha

    2014-12-01

    A novel green recycling process is investigated to prepare lead acetate trihydrate precursors and novel ultrafine lead oxide from spent lead acid battery pastes. The route contains the following four processes. (1) The spent lead pastes are desulphurized by (NH4)2CO3. (2) The desulphurized pastes are converted into lead acetate solution by leaching with acetic acid solution and H2O2; (3) The Pb(CH3COO)2·3H2O precursor is crystallized and purified from the lead acetate solution with the addition of glacial acetic acid; (4) The novel ultrafine lead oxide is prepared by the calcination of lead acetate trihydrate precursor in N2 or air at 320-400 °C. Both the lead acetate trihydrate and lead oxide products are characterized by TG-DTA, XRD, and SEM techniques. The calcination products are mainly α-PbO, β-PbO, and a small amount of metallic Pb. The particle size of the calcination products in air is significantly larger than that in N2. Cyclic voltammetry measurements of the novel ultrafine lead oxide products show good reversibility and cycle stability. The assembled batteries using the lead oxide products as cathode active materials show a good cyclic stability in 80 charge/discharge cycles with the depth of discharge (DOD) of 100%.

  5. Leading Causes of Blindness

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues Feature: Vision Leading Causes of Blindness Past Issues / Summer 2008 ... of the lenses in your eyes. They affect vision and are very common in older people. More ...

  6. Lead alloys: past, present and future

    NASA Astrophysics Data System (ADS)

    Bagshaw, N. E.

    The most critical non-active component in the lead/acid battery is the grid or substrate. A review of the work on grids and grid alloys in the period 1960-1993 has been carried out by the Advanced Lead-Acid Battery Consortium and, in this paper, the results are analyzed in relation to the effort expended on different alloy systems. Lead-antimony alloys and the effects on them of additions of arsenic, tin, and grain-refining elements (selenium, sulfur, copper), together with lead-calcium alloys and the effect on them of tin additions, have received the greatest attention in the past. Proposals are made for future studies. Possible evolutionary developments include the addition of silver and higher amounts of tin to lead-calcium alloys, more detailed investigations of lead-strontium and lead-lithium alloys containing tin and/or silver, and further work on very-low-antimony alloys. More speculative projects are very rapidly cooled alloys, the use of aluminium as grids or spines, plastic/lead-coated copper negative grids, corrosion-resistant coatings of lead compounds on the grids and, finally, a substrate for a bipolar plate that is based on conductive inorganic compounds.

  7. Human lead absorption -- Texas.

    PubMed

    1997-09-19

    In December 1971, the City-County Health Department in El Paso, Texas, discovered that an ore smelter in El Paso was discharging large quantities of lead and other metallic wastes into the air. Between 1969 and 1971, this smelter had released 1,116 tons of lead, 560 tons of zinc, 12 tons of cadmium, and 1.2 tons of arsenic into the atmosphere through its stacks.

  8. Lead carbonate scintillator materials

    DOEpatents

    Derenzo, S.E.; Moses, W.W.

    1991-05-14

    Improved radiation detectors containing lead carbonate or basic lead carbonate as the scintillator element are disclosed. Both of these scintillators have been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to other known scintillator materials. The radiation detectors disclosed are favorably suited for use in general purpose detection and in medical uses. 3 figures.

  9. CERES Web Links

    Atmospheric Science Data Center

    2013-03-21

        Web Links to Relevant CERES Information Relevant information about ... for Satellite Applications and Research) Surface and Atmospheric Radiation Budget (SARB) Working Group homepage ... information for CRS users including: CERES Surface Properties . CERES Ocean Validation Experiment (COVE)  at ...

  10. Australian Curriculum Linked Lessons

    ERIC Educational Resources Information Center

    Hurrell, Derek; O'Neil, Jennifer

    2011-01-01

    In providing a continued focus on tasks and activities that help to illustrate key ideas embedded in the new Australian Curriculum, this issue the authors focus, on Geometry in the Measurement and Geometry strand with strong links for an integrated focus on the Statistics and Probability strand. The small unit of work on the sorting and…

  11. Linking Literacy and Movement

    ERIC Educational Resources Information Center

    Pica, Rae

    2010-01-01

    There are many links between literacy and movement. Movement and language are both forms of communication and self-expression. Rhythm is an essential component of both language and movement. While people may think of rhythm primarily in musical terms, there is a rhythm to words and sentences as well. Individuals develop an internal rhythm when…

  12. Editorial: Lead Risk Assessment and Health Effects.

    PubMed

    Mielke, Howard W

    2016-01-01

    In 1980, Clair C. Patterson stated: "Sometime in the near future it probably will be shown that the older urban areas of the United States have been rendered more or less uninhabitable by the millions of tons of poisonous industrial lead residues that have accumulated in cities during the past century". We live in the near future about which this quote expressed concern. This special volume of 19 papers explores the status of scientific evidence regarding Dr. Patterson's statement on the habitability of the environments of communities. Authors from 10 countries describe a variety of lead issues in the context of large and small communities, smelter sites, lead industries, lead-based painted houses, and vehicle fuel treated with lead additives dispersed by traffic. These articles represent the microcosm of the larger health issues associated with lead. The challenges of lead risk require a concerted global action for primary prevention. PMID:27314364

  13. Editorial: Lead Risk Assessment and Health Effects

    PubMed Central

    Mielke, Howard W.

    2016-01-01

    In 1980, Clair C. Patterson stated: “Sometime in the near future it probably will be shown that the older urban areas of the United States have been rendered more or less uninhabitable by the millions of tons of poisonous industrial lead residues that have accumulated in cities during the past century”. We live in the near future about which this quote expressed concern. This special volume of 19 papers explores the status of scientific evidence regarding Dr. Patterson’s statement on the habitability of the environments of communities. Authors from 10 countries describe a variety of lead issues in the context of large and small communities, smelter sites, lead industries, lead-based painted houses, and vehicle fuel treated with lead additives dispersed by traffic. These articles represent the microcosm of the larger health issues associated with lead. The challenges of lead risk require a concerted global action for primary prevention. PMID:27314364

  14. A Quantative Adverse Outcome Pathway Linking Aromatase Inhibition in Fathead Minnows with Population Dynamics

    EPA Science Inventory

    A Quantitative Adverse Outcome Pathway Linking Aromatase Inhibition in Fathead Minnows with Population DynamicsAn adverse outcome pathway (AOP) is a qualitative description linking a molecular initiating event (MIE) with measureable key events leading to an adverse outcome (AO). ...

  15. Magnesium Diboride Current Leads

    NASA Technical Reports Server (NTRS)

    Panek, John

    2010-01-01

    A recently discovered superconductor, magnesium diboride (MgB2), can be used to fabricate conducting leads used in cryogenic applications. Dis covered to be superconducting in 2001, MgB2 has the advantage of remaining superconducting at higher temperatures than the previously used material, NbTi. The purpose of these leads is to provide 2 A of electricity to motors located in a 1.3 K environment. The providing environment is a relatively warm 17 K. Requirements for these leads are to survive temperature fluctuations in the 5 K and 11 K heat sinks, and not conduct excessive heat into the 1.3 K environment. Test data showed that each lead in the assembly could conduct 5 A at 4 K, which, when scaled to 17 K, still provided more than the required 2 A. The lead assembly consists of 12 steelclad MgB2 wires, a tensioned Kevlar support, a thermal heat sink interface at 4 K, and base plates. The wires are soldered to heavy copper leads at the 17 K end, and to thin copper-clad NbTi leads at the 1.3 K end. The leads were designed, fabricated, and tested at the Forschungszentrum Karlsruhe - Institut foer Technische Physik before inclusion in Goddard's XRS (X-Ray Spectrometer) instrument onboard the Astro-E2 spacecraft. A key factor is that MgB2 remains superconducting up to 30 K, which means that it does not introduce joule heating as a resistive wire would. Because the required temperature ranges are 1.3-17 K, this provides a large margin of safety. Previous designs lost superconductivity at around 8 K. The disadvantage to MgB2 is that it is a brittle ceramic, and making thin wires from it is challenging. The solution was to encase the leads in thin steel tubes for strength. Previous designs were so brittle as to risk instrument survival. MgB2 leads can be used in any cryogenic application where small currents need to be conducted at below 30 K. Because previous designs would superconduct only at up to 8 K, this new design would be ideal for the 8-30 K range.

  16. CAN FLUORIDATION AFFECT WATER LEAD (II) LEVELS AND LEAD (II) NEUROTOXICITY?

    EPA Science Inventory

    Recent reports have attempted to show that certain approaches to fluoridating potable water is linked to increased levels of lead(II) in the blood. We examine these claims in light of the established science and critically evaluate their significance. The completeness of hexafl...

  17. Adverse reactions to food additives.

    PubMed

    Simon, R A

    1986-01-01

    There are thousands of agents that are intentionally added to the food that we consume. These include preservatives, stabilizers, conditioners, thickeners, colorings, flavorings, sweeteners, antioxidants, etc. etc. Yet only a surprisingly small number have been associated with hypersensitivity reactions. Amongst all the additives, FD&C dyes have been most frequently associated with adverse reactions. Tartrazine is the most notorious of them all; however, critical review of the medical literature and current Scripps Clinic studies would indicate that tartrazine has been confirmed to be at best only occasionally associated with flares of urticaria or asthma. There is no convincing evidence in the literature of reactivity to the other azo or nonazo dyes. This can also be said of BHA/BHT, nitrites/nitrates and sorbates. Parabens have been shown to elicit IgE mediated hypersensitivity reactions when used as pharmaceutical preservatives; however, as with the other additives noted above, ingested parabens have only occasionally been associated with adverse reactions. MSG, the cause of the 'Chinese restaurant syndrome' has only been linked to asthma in one report. Sulfiting agents used primarily as food fresheners and to control microbial growth in fermented beverages have been established as the cause of any where from mild to severe and even fatal reactions in at least 5% of the asthmatic population. Other reactions reported to follow sulfite ingestion include anaphylaxis, gastro intestinal complaints and dermatological eruptions. The prevalence of these non asthmatic reactions is unknown. The mechanism of sulfite sensitive asthma is also unknown but most likely involves hyperreactivity to inhale SO2 in the great majority of cases; however, there are reports of IgE mediated reactions and other sulfite sensitive asthmatics have been found with low levels of sulfite oxidase; necessary to oxidize endogenous sulfite to sulfate.

  18. Lead zirconate titanate ceramics

    SciTech Connect

    Walker, B.E. Jr.

    1986-12-02

    This patent describes a lead zirconate titanate (PZT) piezoelectric ceramic composition which, based on total composition weight, consists essentially of a solid solution of lead zirconate and lead titanate in a PbZrO/sub 3/:PbTiO/sub 3/ ratio from about 0.505:0.495 to about 0.54:0.46; a halide salt selected from the group consisting of fluorides and chlorides of alkali metal and alkaline earth elements and mixtures thereof except for francium and radium in an amount from about 0.5 to 2 weight percent; and an oxide selected from the group consisting of magnesium, barium, scandium, aluminum, lanthanum, praesodynium, neodymium, samarium, and mixtures thereof in an amount from about 0.5 to about 6 weight percent, the relative amount of oxide being from about 1 to about 4 times that of the halide.

  19. Leading healthcare in complexity.

    PubMed

    Cohn, Jeffrey

    2014-12-01

    Healthcare institutions and providers are in complexity. Networks of interconnections from relationships and technology create conditions in which interdependencies and non-linear dynamics lead to surprising, unpredictable outcomes. Previous effective approaches to leadership, focusing on top-down bureaucratic methods, are no longer effective. Leading in complexity requires leaders to accept the complexity, create an adaptive space in which innovation and creativity can flourish and then integrate the successful practices that emerge into the formal organizational structure. Several methods for doing adaptive space work will be discussed. Readers will be able to contrast traditional leadership approaches with leading in complexity. They will learn new behaviours that are required of complexity leaders, along with challenges they will face, often from other leaders within the organization. PMID:25815410

  20. Leading healthcare in complexity.

    PubMed

    Cohn, Jeffrey

    2014-12-01

    Healthcare institutions and providers are in complexity. Networks of interconnections from relationships and technology create conditions in which interdependencies and non-linear dynamics lead to surprising, unpredictable outcomes. Previous effective approaches to leadership, focusing on top-down bureaucratic methods, are no longer effective. Leading in complexity requires leaders to accept the complexity, create an adaptive space in which innovation and creativity can flourish and then integrate the successful practices that emerge into the formal organizational structure. Several methods for doing adaptive space work will be discussed. Readers will be able to contrast traditional leadership approaches with leading in complexity. They will learn new behaviours that are required of complexity leaders, along with challenges they will face, often from other leaders within the organization.

  1. Performance Boosting Additive

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Mainstream Engineering Corporation was awarded Phase I and Phase II contracts from Goddard Space Flight Center's Small Business Innovation Research (SBIR) program in early 1990. With support from the SBIR program, Mainstream Engineering Corporation has developed a unique low cost additive, QwikBoost (TM), that increases the performance of air conditioners, heat pumps, refrigerators, and freezers. Because of the energy and environmental benefits of QwikBoost, Mainstream received the Tibbetts Award at a White House Ceremony on October 16, 1997. QwikBoost was introduced at the 1998 International Air Conditioning, Heating, and Refrigeration Exposition. QwikBoost is packaged in a handy 3-ounce can (pressurized with R-134a) and will be available for automotive air conditioning systems in summer 1998.

  2. Sewage sludge additive

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Mueller, W. A.; Ingham, J. D. (Inventor)

    1980-01-01

    The additive is for a raw sewage treatment process of the type where settling tanks are used for the purpose of permitting the suspended matter in the raw sewage to be settled as well as to permit adsorption of the dissolved contaminants in the water of the sewage. The sludge, which settles down to the bottom of the settling tank is extracted, pyrolyzed and activated to form activated carbon and ash which is mixed with the sewage prior to its introduction into the settling tank. The sludge does not provide all of the activated carbon and ash required for adequate treatment of the raw sewage. It is necessary to add carbon to the process and instead of expensive commercial carbon, coal is used to provide the carbon supplement.

  3. Perspectives on Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Bourell, David L.

    2016-07-01

    Additive manufacturing (AM) has skyrocketed in visibility commercially and in the public sector. This article describes the development of this field from early layered manufacturing approaches of photosculpture, topography, and material deposition. Certain precursors to modern AM processes are also briefly described. The growth of the field over the last 30 years is presented. Included is the standard delineation of AM technologies into seven broad categories. The economics of AM part generation is considered, and the impacts of the economics on application sectors are described. On the basis of current trends, the future outlook will include a convergence of AM fabricators, mass-produced AM fabricators, enabling of topology optimization designs, and specialization in the AM legal arena. Long-term developments with huge impact are organ printing and volume-based printing.

  4. Sarks as additional fermions

    NASA Astrophysics Data System (ADS)

    Agrawal, Jyoti; Frampton, Paul H.; Jack Ng, Y.; Nishino, Hitoshi; Yasuda, Osamu

    1991-03-01

    An extension of the standard model is proposed. The gauge group is SU(2) X ⊗ SU(3) C ⊗ SU(2) S ⊗ U(1) Q, where all gauge symmetries are unbroken. The colour and electric charge are combined with SU(2) S which becomes strongly coupled at approximately 500 GeV and binds preons to form fermionic and vector bound states. The usual quarks and leptons are singlets under SU(2) X but additional fermions, called sarks. transform under it and the electroweak group. The present model explains why no more than three light quark-lepton families can exist. Neutral sark baryons, called narks, are candidates for the cosmological dark matter having the characteristics designed for WIMPS. Further phenomenological implications of sarks are analyzed i including electron-positron annihilation. Z 0 decay, flavor-changing neutral currents. baryon-number non-conservation, sarkonium and the neutron electric dipole moment.

  5. High stability radio links

    NASA Technical Reports Server (NTRS)

    Kursinski, E. Robert

    1989-01-01

    Radio telecommunication links are used for communication with deep space probes. These links consist of sinusoidal carrier signals at radio frequencies (RF) modulated with information sent between the spacecraft and the earth. This carrier signal is a very pure and stable sinusoid, typically derived from an atomic frequency standard whose frequency and phase are used to measure the radial velocity of the probe and from this and other data types derive its trajectory. This same observable can be used to search for space-time distortions cased by low frequency (0.1 to 100 MHz) gravitation radiation. How such a system works, what its sensitivity limitations are, and what potential future improvements can be made are discussed.

  6. Mutations in the RPGR gene cause X-linked cone dystrophy.

    PubMed

    Yang, Zhenglin; Peachey, Neal S; Moshfeghi, Darius M; Thirumalaichary, Sukanya; Chorich, Lou; Shugart, Yin Y; Fan, Keke; Zhang, Kang

    2002-03-01

    X-linked cone dystrophy is a type of hereditary retinal degeneration characterized by a progressive dysfunction of the day vision or photopic (cone) system with preservation of night vision or scotopic (rod) function. The disease presents with a triad of photophobia, loss of color vision and reduced central vision. This phenotype is distinct from retinitis pigmentosa (RP) in which there are prominent night and peripheral vision disturbances. X-linked cone dystrophy is a genetically heterogeneous disorder, with linkage to loci on Xp11.4--Xp21.1 (COD1, OMIM 304020) and Xq27 (COD2, OMIM 303800). COD1 maps to a region that harbors the RPGR gene, mutations in which account for >70% of patients with X-linked RP. The majority of these mutations reside in one purine-rich exon, ORF15, encoding 567 amino acids with a repetitive domain rich in glutamic acid residues. We mapped two families with X-linked cone dystrophy to the COD1 locus and identified two distinct mutations in ORF15 in the RPGR gene (ORF15+1343_1344delGG and ORF15+694_708del15) leading to a frame-shift and premature termination of translation in one case and a deletion of five amino acids in another. Consistent with expression of RPGR in rods and cones, our results show that mutations in RPGR, in addition to X-linked RP, can also cause cone-specific degeneration.

  7. Mutagenic effects of lead (II) bromide.

    PubMed

    Maslat, A O; Haas, H J

    1989-12-01

    The mutagenicity of lead (II) bromide (a combustion product of the gasoline additives lead (IV) tetraethyl and 1,2-dibromoethane) was investigated using various strains of bacteria. Taking prodigiosin (the red pigment) production as a marker, lead (II) bromide was found to be mutagenic in S. marcescens, leading to the appearance of white mutant colonies that are unable to produce such a pigment. This compound was also found to be mutagenic in E. coli KMBL1851, resulting in the appearance of rifampicin-resistant mutants in addition to Met+ and His+ revertants. Some of the S. marcescens mutants were found to be reversible, able to resynthesize prodigiosin. Differences in the sensitivity to antibiotics as well as in the biochemical properties were detected between the mutants and their corresponding wild types. Lead (II) bromide gave positive results in the Ames test performed with strain TA 1535.

  8. Linking reengineering to revitalization.

    PubMed

    Moravec, M

    1996-01-01

    A health care organization that embarks on reengineering without a strategy for revitalizing is courting disaster. What does it take to get reengineering right? It takes vision, unflinching commitment, new kinds of leadership and business strategies, and new behaviors to challenge the old manager-physician power dynamic. A low-cost health care provider must be able to promote trust, partnerships, and competencies that are specifically linked to accessible, cost-effective patient care.

  9. Neutron Characterization for Additive Manufacturing

    NASA Technical Reports Server (NTRS)

    Watkins, Thomas; Bilheux, Hassina; An, Ke; Payzant, Andrew; DeHoff, Ryan; Duty, Chad; Peter, William; Blue, Craig; Brice, Craig A.

    2013-01-01

    Oak Ridge National Laboratory (ORNL) is leveraging decades of experience in neutron characterization of advanced materials together with resources such as the Spallation Neutron Source (SNS) and the High Flux Isotope Reactor (HFIR) shown in Fig. 1 to solve challenging problems in additive manufacturing (AM). Additive manufacturing, or three-dimensional (3-D) printing, is a rapidly maturing technology wherein components are built by selectively adding feedstock material at locations specified by a computer model. The majority of these technologies use thermally driven phase change mechanisms to convert the feedstock into functioning material. As the molten material cools and solidifies, the component is subjected to significant thermal gradients, generating significant internal stresses throughout the part (Fig. 2). As layers are added, inherent residual stresses cause warping and distortions that lead to geometrical differences between the final part and the original computer generated design. This effect also limits geometries that can be fabricated using AM, such as thin-walled, high-aspect- ratio, and overhanging structures. Distortion may be minimized by intelligent toolpath planning or strategic placement of support structures, but these approaches are not well understood and often "Edisonian" in nature. Residual stresses can also impact component performance during operation. For example, in a thermally cycled environment such as a high-pressure turbine engine, residual stresses can cause components to distort unpredictably. Different thermal treatments on as-fabricated AM components have been used to minimize residual stress, but components still retain a nonhomogeneous stress state and/or demonstrate a relaxation-derived geometric distortion. Industry, federal laboratory, and university collaboration is needed to address these challenges and enable the U.S. to compete in the global market. Work is currently being conducted on AM technologies at the ORNL

  10. [Riboflavin UVA cross-linking for keratoconus].

    PubMed

    Maier, P; Reinhard, T

    2013-09-01

    Keratoconus is a progressive, ectatic disease of the cornea leading to thinning and highly irregular astigmatism. Until recently all treatment options, such as prescription of glasses or contact lenses were symptomatic and neither keratoplasty nor the implantation of intracorneal rings can heal the disease. Riboflavin ultraviolet A (UVA) collagen cross-linking (CXL) cannot heal keratoconus either but promises to halt the progression. The therapeutic principle is a photochemical reaction of riboflavin and UVA light leading to free oxygen radicals in the corneal stroma that induce covalent linking of the collagen fibrils. This stiffening effect should stop the progression. After the first reports at the end of the 1990s the treatment was widely used and many case series show that CXL can be effective in stopping disease progression in some patients. However, randomized, controlled multicenter trials showing high evidence of the treatment effectiveness are rare. This report includes a review of the literature regarding treatment effectiveness, indications and new developments. PMID:23760423

  11. Indoor firing ranges and elevated blood lead levels - United States, 2002-2013.

    PubMed

    Beaucham, Catherine; Page, Elena; Alarcon, Walter A; Calvert, Geoffrey M; Methner, Mark; Schoonover, Todd M

    2014-04-25

    Indoor firing ranges are a source of lead exposure and elevated blood lead levels (BLLs) among employees, their families, and customers, despite public health outreach efforts and comprehensive guidelines for controlling occupational lead exposure. There are approximately 16,000-18,000 indoor firing ranges in the United States, with tens of thousands of employees. Approximately 1 million law enforcement officers train on indoor ranges. To estimate how many adults had elevated BLLs (≥10 µg/dL) as a result of exposure to lead from shooting firearms, data on elevated BLLs from the Adult Blood Lead Epidemiology and Surveillance (ABLES) program managed by CDC's National Institute for Occupational Safety and Health (NIOSH) were examined by source of lead exposure. During 2002-2012, a total of 2,056 persons employed in the categories "police protection" and "other amusement and recreation industries (including firing ranges)" had elevated BLLs reported to ABLES; an additional 2,673 persons had non-work-related BLLs likely attributable to target shooting. To identify deficiencies at two indoor firing ranges linked to elevated BLLs, the Washington State Division of Occupational Safety and Health (WaDOSH) and NIOSH conducted investigations in 2012 and 2013, respectively. The WaDOSH investigation found a failure to conduct personal exposure and biologic monitoring for lead and also found dry sweeping of lead-containing dust. The NIOSH investigation found serious deficiencies in ventilation, housekeeping, and medical surveillance. Public health officials and clinicians should ask about occupations and hobbies that might involve lead when evaluating findings of elevated BLLs. Interventions for reducing lead exposure in firing ranges include using lead-free bullets, improving ventilation, and using wet mopping or high-efficiency particulate air (HEPA) vacuuming to clean. PMID:24759656

  12. PIPELINES AS COMMUNICATION NETWORK LINKS

    SciTech Connect

    Kelvin T. Erickson; Ann Miller; E. Keith Stanek; C.H. Wu; Shari Dunn-Norman

    2005-03-14

    This report presents the results of an investigation into two methods of using the natural gas pipeline as a communication medium. The work addressed the need to develop secure system monitoring and control techniques between the field and control centers and to robotic devices in the pipeline. In the first method, the pipeline was treated as a microwave waveguide. In the second method, the pipe was treated as a leaky feeder or a multi-ground neutral and the signal was directly injected onto the metal pipe. These methods were tested on existing pipeline loops at UMR and Batelle. The results reported in this report indicate the feasibility of both methods. In addition, a few suitable communication link protocols for this network were analyzed.

  13. X-linked congenital retinoschisis.

    PubMed

    Kellner, U; Brümmer, S; Foerster, M H; Wessing, A

    1990-01-01

    The natural history and electrophysiological findings of 52 patients with X-linked congenital retinoschisis with a follow-up of up to 26 years are described. The mean visual acuity was reduced to 0.24 +/- 0.2 and remained unchanged in most patients during this time. If visual loss occurred, it usually happened in the first decennium. The complications were retinal detachments in 11% and vitreous hemorrhages in 4% of the eyes. In general, the vitreous hemorrhages resolved spontaneously. Retinal detachments were treated successfully with conventional buckling procedures. Redetachments occurred in about 40%. Prophylactic laser coagulation was of no use because it was complicated by detachment in 43% of our series. The electro-oculogram was usually normal. In addition to the known electrorentinographic findings of normal a-wave and reduced b-wave amplitudes, we found prolonged b-wave latencies and implicit times, as well as a reduced 30 Hz flicker response.

  14. Federal regulation of lead in drinking water

    SciTech Connect

    Reiss, K.M.

    1991-12-31

    The decline of the Roman Empire has been attributed, in part, to lead poisoning. Scholars have reported that Roman food, water and wine all contained excessive amounts of lead. Although Americans ingest considerably less lead than did the ancient Romans, lead poisoning still poses a significant public health threat in this country, particularly to children. The Federal Centers for Disease Control (CDC) recently reported that more than four million children suffer from lead poisoning. The director of the CDC has stated that {open_quotes}lead poisoning is the No. 1 environmental problem facing America`s children.{close_quotes} In addition to threatening children, lead poisoning presents health dangers to adults and, ironically, to federal government officials themselves. For example, at the Environmental Protection Agency (EPA) headquarters, water samples at nineteen sources were found to contain excessive amounts of lead. Additionally, a survey of twelve Capitol Hill buildings found that twenty-one percent of the water sources tested contained excessive lead levels.

  15. Probabilistic method to assess insulating link performance for protection of crane workers

    SciTech Connect

    Karady, G.G.; Shah, M.; Dumora, D.

    1996-01-01

    Contact between cranes and transmission lines is the most frequent cause of accidents, which may lead to electrocution of an operator or rigger. This accident can be prevented by inserting an insulating link in the crane`s cable. This paper analyzes currents during accidents and proposes a modified test method for contaminated insulating links. A new and better insulating link is also introduced. Flashover probability of contaminated insulator links is measured. The tests results are evaluated with a new probabilistic method which leads to better assessment of link efficiency. The paper concludes that the risk of link failure cannot be determined without the new flashover probability measurement.

  16. Lead and compounds (inorganic)

    Integrated Risk Information System (IRIS)

    Lead and compounds ( inorganic ) ; CASRN 7439 - 92 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for

  17. Girls Leading Outward

    ERIC Educational Resources Information Center

    Hamed, Heather; Reyes, Jazmin; Moceri, Dominic C.; Morana, Laura; Elias, Maurice J.

    2011-01-01

    The authors describe a program implemented in Red Bank Middle School in New Jersey to help at-risk, minority middle school girls realize their leadership potential. The GLO (Girls Leading Outward) program was developed by the Developing Safe and Civil Schools Project at Rutgers University and is facilitated by university students. Selected middle…

  18. Lead Poisoning in Children.

    ERIC Educational Resources Information Center

    Lin-Fu, Jane S.

    Designed as a public information pamphlet, the text discusses the problem of lead poisoning in children. The preventable nature of the problem is stressed as well as needed action on the part of the public, physicians and other health workers, and the legislators. The pamphlet emphasizes that each of these areas is essential in preventing death or…

  19. Change, Lead, Succeed

    ERIC Educational Resources Information Center

    Munger, Linda; von Frank, Valerie

    2010-01-01

    Redefine leadership in your school, and create capacity through school leadership teams that successfully coordinate professional learning. "Change, Lead, Succeed" shows school leaders and teachers in leadership roles what they need to know to effectively create a culture for change. Find out what distinguishes a school leadership team from other…

  20. Leading through Conflict

    ERIC Educational Resources Information Center

    Gerzon, Mark

    2006-01-01

    This article talks about leading significant learning opportunities through conflict of ideas in a school system. Catalyzing school change can turn emotional differences of opinion into learning opportunities. Leaders who want to deal effectively with these challenging, often tense situations need to be more than good managers. They need to be…

  1. Leading for Engagement

    ERIC Educational Resources Information Center

    Yazzie-Mintz, Ethan

    2010-01-01

    As the dropout problem has grown--and as increasing numbers of students have started to see dropping out as a viable option for expressing their disaffection with school--practitioners, policymakers, and researchers have looked more closely at the factors that lead students to disengage from school and have attempted to find ways to create…

  2. Lead Thickness Measurements

    SciTech Connect

    Rucinski, R.; /Fermilab

    1998-02-16

    The preshower lead thickness applied to the outside of D-Zero's superconducting solenoid vacuum shell was measured at the time of application. This engineering documents those thickness measurements. The lead was ordered in sheets 0.09375-inch and 0.0625-inch thick. The tolerance on thickness was specified to be +/- 0.003-inch. The sheets all were within that thickness tolerance. The nomenclature for each sheet was designated 1T, 1B, 2T, 2B where the numeral designates it's location in the wrap and 'T' or 'B' is short for 'top' or 'bottom' half of the solenoid. Micrometer measurements were taken at six locations around the perimeter of each sheet. The width,length, and weight of each piece was then measured. Using an assumed pure lead density of 0.40974 lb/in{sup 3}, an average sheet thickness was calculated and compared to the perimeter thickness measurements. In every case, the calculated average thickness was a few mils thinner than the perimeter measurements. The ratio was constant, 0.98. This discrepancy is likely due to the assumed pure lead density. It is not felt that the perimeter is thicker than the center regions. The data suggests that the physical thickness of the sheets is uniform to +/- 0.0015-inch.

  3. ALL AGES LEAD MODEL

    EPA Science Inventory

    The Integrated Exposure Uptake Biokinetic (IEUBK) Model for Lead in Children (version 0.99d) was released in March 1994, and has been widely accepted in the risk assessment community as a tool for implementing the site specific risk assessment process when the issue is childhood...

  4. Leading by Learning

    ERIC Educational Resources Information Center

    Brookhart, Susan M.; Moss, Connie M.

    2013-01-01

    A lot has changed in the principalship since the principal was the head teacher in a school. Current principals are building administrators and that is likely to continue, the authors posit. Nonetheless, they report their study focusing on leadership's role in formative assessment concluded that in order to lead learning the principal must…

  5. Lead Policy and Academic Performance: Insights from Massachusetts

    ERIC Educational Resources Information Center

    Reyes, Jessica Wolpaw

    2015-01-01

    In this article, Jessica Wolpaw Reyes investigates the link between lead exposure and student achievement in Massachusetts. Childhood exposure to even low levels of lead can adversely affect neurodevelopment, behavior, and cognitive performance. Using a panel dataset of cohorts of children born in the 1990s who were third and fourth graders in the…

  6. Leading time domain seismic precursors

    NASA Astrophysics Data System (ADS)

    Boucouvalas, A. C.; Gkasios, M.; Keskebes, A.; Tselikas, N. T.

    2014-08-01

    The problem of predicting the occurrence of earthquakes is threefold. On one hand it is necessary to predict the date and magnitude of an earthquake, and on the other hand the location of the epicenter. In this work after a brief review of the state of earthquake prediction research, we report on a new leading time precursor for determining time onset of earthquake occurrence. We report the linking between earthquakes of the past with those which happen in the future via Fibonacci, Dual and Lucas numbers (FDL) numbers. We demonstrate it here with two example seed earthquakes at least 100 years old. Using this leading indicator method we can predict significant earthquake events >6.5R, with good accuracy approximately +- 1 day somewhere in the world. From a single seed we produce at least 100 trials simultaneously of which 50% are correct to +- 1day. The indicator is based on Fibonacci, Dual and Lucas numbers (FDL). This result hints that the log periodic FDL numbers are at the root of the understanding of the earthquake mechanism. The theory is based on the assumption that each occurred earthquake discontinuity can be thought of as a generating source of FDL time series. (The mechanism could well be linked to planetary orbits). When future dates are derived from clustering and convergence from previous strong earthquake dates at an FDL time distance, then we have a high probability for an earthquake to occur on that date. We set up a real time system which generates FDL time series from each previous significant earthquake (>7R) and we produce a year to year calendar of high probability earthquake dates. We have tested this over a number of years with considerable success. We have applied this technique for strong (>7R) earthquakes across the globe as well as on a restricted region such as the Greek geographic region where the magnitude is small (>4R-6.5R). In both cases the success of the method is impressive. It is our belief that supplementing this method with

  7. Additive lattice kirigami

    PubMed Central

    Castle, Toen; Sussman, Daniel M.; Tanis, Michael; Kamien, Randall D.

    2016-01-01

    Kirigami uses bending, folding, cutting, and pasting to create complex three-dimensional (3D) structures from a flat sheet. In the case of lattice kirigami, this cutting and rejoining introduces defects into an underlying 2D lattice in the form of points of nonzero Gaussian curvature. A set of simple rules was previously used to generate a wide variety of stepped structures; we now pare back these rules to their minimum. This allows us to describe a set of techniques that unify a wide variety of cut-and-paste actions under the rubric of lattice kirigami, including adding new material and rejoining material across arbitrary cuts in the sheet. We also explore the use of more complex lattices and the different structures that consequently arise. Regardless of the choice of lattice, creating complex structures may require multiple overlapping kirigami cuts, where subsequent cuts are not performed on a locally flat lattice. Our additive kirigami method describes such cuts, providing a simple methodology and a set of techniques to build a huge variety of complex 3D shapes. PMID:27679822

  8. Additive lattice kirigami

    PubMed Central

    Castle, Toen; Sussman, Daniel M.; Tanis, Michael; Kamien, Randall D.

    2016-01-01

    Kirigami uses bending, folding, cutting, and pasting to create complex three-dimensional (3D) structures from a flat sheet. In the case of lattice kirigami, this cutting and rejoining introduces defects into an underlying 2D lattice in the form of points of nonzero Gaussian curvature. A set of simple rules was previously used to generate a wide variety of stepped structures; we now pare back these rules to their minimum. This allows us to describe a set of techniques that unify a wide variety of cut-and-paste actions under the rubric of lattice kirigami, including adding new material and rejoining material across arbitrary cuts in the sheet. We also explore the use of more complex lattices and the different structures that consequently arise. Regardless of the choice of lattice, creating complex structures may require multiple overlapping kirigami cuts, where subsequent cuts are not performed on a locally flat lattice. Our additive kirigami method describes such cuts, providing a simple methodology and a set of techniques to build a huge variety of complex 3D shapes.

  9. The formation of linked perceptual classes.

    PubMed Central

    Fields, Lanny; Matneja, Priya; Varelas, Antonios; Belanich, James; Fitzer, Adrienne; Shamoun, Kim

    2002-01-01

    Multiple-exemplar training with stimuli in four domains induced two new fill-based (A1' and A2') and satellite-image-based (B1' and B2') perceptual classes. Conditional discriminations were established between the endpoints of the A1' and B1' classes as well as the A2' and B2' classes. The emergence of linked perceptual classes was evaluated by the performances occasioned by nine cross-class probes that contained fill variants as samples and satellite variants as comparisons, along with nine other cross-class probes that consisted of satellite variants as samples and fill variants as comparisons. The 18 probes were first presented serially and then concurrently. Class-consistent responding indicated the emergence of linked perceptual classes. Of the linked perceptual classes, 70% emerged during the initial serial test. An additional 20% of the linked perceptual classes emerged during the subsequently presented concurrent test block. Thus, linked perceptual classes emerged on an immediate or delayed basis. Linked perceptual classes, then, share structural and fuctional similarities with equivalence classes, generalized equivalence classes, cross-modal classes, and complex maturally occurring categories, and may clarify processes such as intersensory perception. PMID:12507004

  10. The formation of linked perceptual classes.

    PubMed

    Fields, Lanny; Matneja, Priya; Varelas, Antonios; Belanich, James; Fitzer, Adrienne; Shamoun, Kim

    2002-11-01

    Multiple-exemplar training with stimuli in four domains induced two new fill-based (A1' and A2') and satellite-image-based (B1' and B2') perceptual classes. Conditional discriminations were established between the endpoints of the A1' and B1' classes as well as the A2' and B2' classes. The emergence of linked perceptual classes was evaluated by the performances occasioned by nine cross-class probes that contained fill variants as samples and satellite variants as comparisons, along with nine other cross-class probes that consisted of satellite variants as samples and fill variants as comparisons. The 18 probes were first presented serially and then concurrently. Class-consistent responding indicated the emergence of linked perceptual classes. Of the linked perceptual classes, 70% emerged during the initial serial test. An additional 20% of the linked perceptual classes emerged during the subsequently presented concurrent test block. Thus, linked perceptual classes emerged on an immediate or delayed basis. Linked perceptual classes, then, share structural and fuctional similarities with equivalence classes, generalized equivalence classes, cross-modal classes, and complex maturally occurring categories, and may clarify processes such as intersensory perception.

  11. Therapy of X-linked adrenoleukodystrophy.

    PubMed

    Semmler, Alexander; Köhler, Wolfgang; Jung, Hans H; Weller, Michael; Linnebank, Michael

    2008-09-01

    X-linked adrenoleukodystrophy (X-ALD; OMIM #300100) is caused by defects of the ABCD1 gene on chromosome Xq28, resulting in an impairment of peroxisomal beta-oxidation and the accumulation of saturated very long chain fatty acids (VLCFAs). Primary manifestations occur in the CNS, the adrenal cortex and the testes' Leydig cells. The clinical presentation shows a marked variability which is not explained by the different X-ALD genotypes. Phenotypes range from rapidly progressive cerebral disease with childhood (childhood cerebral ALD [CCALD]) or adulthood (adult cerebral ALD [ACALD]) onset leading to death within a few years, over adult-onset adrenomyeloneuropathy (AMN) with or without focal CNS demyelination, AMN converting into a rapidly progressive, cerebral demyelinating phenotype resembling CCALD, to slow disease progression over decades, or adrenal insufficiency only. Approximately 50% of female heterozygotes develop moderate spastic paresis resembling the AMN phenotype. This review focuses on current experiences with different therapeutic approaches. Lorenzo's oil did not prove to be effective in cerebral inflammatory disease variants, but asymptomatic patients, and speculatively AMN variants without cerebral involvement, as well as female carriers may benefit from early intake of oleic and erucic acids in addition to VLCFA restriction. Hormone-replacement therapy is necessary in all patients with adrenal insufficiency. Hematopoietic stem cell transplantation has been reported to be effective in presymptomatic or early symptomatic CCALD, and may well also be a final therapeutic option in early ACALD patients. Early detection of mutation carriers and timely initiation of therapy is important for the effectiveness of all therapeutic efforts. Gene therapy of endogenous hematopoietic stem cells, pharmacological upregulation of other genes encoding proteins involved in peroxisomal beta-oxidation, reduction of oxidative stress, and possibly lovastatin are candidates

  12. An Interactive, Integrated, Instructional Pathway to the LEAD Science Gateway

    NASA Astrophysics Data System (ADS)

    Yalda, S.; Clark, R.; Davis, L.; Wiziecki, E. N.

    2008-12-01

    Linked Environments for Atmospheric Discovery (LEAD) is a bold and revolutionary paradigm that through a Web-based Service Oriented Architecture (SOA) exposes the user to a rich environment of data, models, data mining and visualization and analysis tools, enabling the user to ask science questions of applications while the complexity of the software and middleware managing these applications is hidden from the user. From its inception in 2003, LEAD has championed goals that have context for the future of weather and related research and education. LEAD espouses to lowering the barrier for using complex end-to-end weather technologies by a) democratizing the availability of advanced weather technologies, b) empowering the user of these technologies to tackle a variety of problems, and c) facilitating learning and understanding. LEAD, as it exists today, is poised to enable a diverse community of scientists, educators, students, and operational practitioners. The project has been informed by atmospheric and computer scientists, educators, and educational consultants who, in search of new knowledge, understanding, ideas, and learning methodologies, seek easy access to new capabilities that allow for user-directed and interactive query and acquisition, simulation, assimilation, data mining, computational modeling, and visualization. As one component of the total LEAD effort, the LEAD education team has designed interactive, integrated, instructional pathways within a set of learning modules (LEAD-to-Learn) to facilitate, enhance, and enable the use of the LEAD gateway in the classroom. The LEAD education initiative focuses on the means to integrate data, tools, and services used by researchers into undergraduate meteorology education in order to provide an authentic and contextualized environment for teaching and learning. Educators, educational specialists, and students from meteorology and computer science backgrounds have collaborated on the design and development

  13. Quantification of atmospheric lead emissions from 70 years of leaded petrol consumption in Australia

    NASA Astrophysics Data System (ADS)

    Kristensen, Louise Jane

    2015-06-01

    Lead is a persistent pollutant and the subject of many environmental studies, yet, in Australia, the extent of atmospheric lead emissions from the use of leaded petrol is unquantified. This paper details the first comprehensive account of leaded petrol sales and its lead concentrations over the 70 years of use in Australia. The resulting atmospheric lead emissions are calculated to provide the most complete understanding of the volume of lead released to the Australian continent from the consumption of leaded petrol. Atmospheric emissions of lead to the entire Australian continent from leaded petrol are calculated to total 240,510 tonnes over seven decades of use, peaking at 7869 tonnes in 1974. Total emissions for individual states and territories range from 1745 to 67,893 tonnes, with New South Wales responsible for the largest emissions. The effect of regulations on allowable concentrations of tetraethyl-lead additives are observed in the reduction of lead emissions in New South Wales and Victoria. The consequences to human health and the environment of leaded petrol consumption in Australia's populous cities are examined against historical air quality data and blood lead levels.

  14. Incorporation of lead into calcium carbonate granules secreted by earthworms living in lead contaminated soils

    NASA Astrophysics Data System (ADS)

    Fraser, A.; Lambkin, D. C.; Lee, M. R.; Schofield, P. F.; Mosselmans, J. F. W.; Hodson, M. E.

    2011-05-01

    The influence of soil organisms on metal mobility and bioavailability in soils is not currently fully understood. We conducted experiments to determine whether calcium carbonate granules secreted by the earthworm Lumbricus terrestris could incorporate and immobilise lead in lead- and calcium-amended artificial soils. Soil lead concentrations were up to 2000 mg kg -1 and lead:calcium ratios by mass were 0.5-8. Average granule production rates of 0.39 ± 0.04 mg calcite earthworm -1 day -1 did not vary with soil lead concentration. The lead:calcium ratio in granules increased significantly with that of the soil ( r2 = 0.81, p = 0.015) with lead concentrations in granules reaching 1577 mg kg -1. X-ray diffraction detected calcite and aragonite in the granules with indications that lead was incorporated into the calcite at the surface of the granules. In addition to the presence of calcite and aragonite X-ray absorption spectroscopy indicated that lead was present in the granules mainly as complexes sorbed to the surface but with traces of lead-bearing calcite and cerussite. The impact that lead-incorporation into earthworm calcite granules has on lead mobility at lead-contaminated sites will depend on the fraction of total soil lead that would be otherwise mobile.

  15. Linking ultracold polar molecules.

    PubMed

    Avdeenkov, A V; Bohn, John L

    2003-01-31

    We predict that pairs of polar molecules can be weakly bound together in an ultracold environment, provided that a dc electric field is present. The field that links the molecules together also strongly influences the basic properties of the resulting dimer, such as its binding energy and predissociation lifetime. Because of their long-range character, these dimers will be useful in disentangling cold collision dynamics of polar molecules. As an example, we estimate the microwave photoassociation yield for OH-OH cold collisions.

  16. EEE Links. Volume 5

    NASA Technical Reports Server (NTRS)

    Humphrey, Robert (Editor)

    1999-01-01

    The EEE Links Newsletter is a quarterly publication produced by Code 562 in support of the NASA HQ funded NASA Electronic Parts and Packaging (NEPP) Program. The newsletter is produced as an electronic format deliverable made available via the referenced www site administered by Code 562, The newsletter publishes brief articles on topics of interest to NASA programs and projects in the area of electronic parts and packaging. The newsletter does not provide information pertaining to patented or proprietary information. The information provided is at the level of that produced by industry and university researchers and is published at national and international conferences.

  17. LEAD SEVERING CONTRIVANCE

    DOEpatents

    Widmaier, W.

    1958-04-01

    A means for breaking an electrical circuit within an electronic tube during the process of manufacture is described. Frequently such circuits must be employed for gettering or vapor coating purposes, however, since an external pair of corector pins having no use after manufacture, is undesirable, this invention permits the use of existing leads to form a temporary circuit during manufacture, and severing it thereafter. One portion of the temporary circuit, made from a springy material such as tungsten, is spot welded to a fusable member. To cut the circuit an external radiant heat source melts the fusable member, allowing the tensed tungsten spring to contract and break the circuit. This inexpensive arrangement is particularly useful when the tube has a great many external leads crowded into the tube base.

  18. Flight loss linked to faster molecular evolution in insects.

    PubMed

    Mitterboeck, T Fatima; Adamowicz, Sarah J

    2013-09-22

    The loss of flight ability has occurred thousands of times independently during insect evolution. Flight loss may be linked to higher molecular evolutionary rates because of reductions in effective population sizes (Ne) and relaxed selective constraints. Reduced dispersal ability increases population subdivision, may decrease geographical range size and increases (sub)population extinction risk, thus leading to an expected reduction in Ne. Additionally, flight loss in birds has been linked to higher molecular rates of energy-related genes, probably owing to relaxed selective constraints on energy metabolism. We tested for an association between insect flight loss and molecular rates through comparative analysis in 49 phylogenetically independent transitions spanning multiple taxa, including moths, flies, beetles, mayflies, stick insects, stoneflies, scorpionflies and caddisflies, using available nuclear and mitochondrial protein-coding DNA sequences. We estimated the rate of molecular evolution of flightless (FL) and related flight-capable lineages by ratios of non-synonymous-to-synonymous substitutions (dN/dS) and overall substitution rates (OSRs). Across multiple instances of flight loss, we show a significant pattern of higher dN/dS ratios and OSRs in FL lineages in mitochondrial but not nuclear genes. These patterns may be explained by relaxed selective constraints in FL ectotherms relating to energy metabolism, possibly in combination with reduced Ne.

  19. X-linked recessive atrophic macular degeneration from RPGR mutation.

    PubMed

    Ayyagari, Radha; Demirci, F Yesim; Liu, Jiafan; Bingham, Eve L; Stringham, Heather; Kakuk, Laura E; Boehnke, Michael; Gorin, Michael B; Richards, Julia E; Sieving, Paul A

    2002-08-01

    We mapped a new X-linked recessive atrophic macular degeneration locus to Xp21.1-p11.4 and show allelic involvement of the gene RPGR, which normally causes severe peripheral retinal degeneration leading to global blindness. Ten affected males whom we examined had primarily macular atrophy causing progressive loss of visual acuity with minimal peripheral visual impairment. One additional male showed extensive macular degeneration plus peripheral loss of retinal pigment epithelium and choriocapillaries. Full-field electroretinograms (ERGs) showed normal cone and rod responses in some affected males despite advanced macular degeneration, emphasizing the dissociation of atrophic macular degeneration from generalized cone degenerations, including X-linked cone dystrophy (COD1). The RPGR gene nonsense mutation G-->T at open reading frame (ORF)15+1164 cosegregated with the disease and may create a donor splice site. Identification of an RPGR mutation in atrophic maculardegeneration expands the phenotypic range associated with this gene and provides a new tool for the dissection of the relationship between clinically different retinal pathologies.

  20. Evidence for linkage disequilibrium in chromosome 13-linked Duchenne-like muscular dystrophy

    SciTech Connect

    Othmane, K.B.; Speer, M.C.; Stauffer, J.

    1995-09-01

    Duchenne-like muscular dystrophy (DLMD) is an autosomal recessive Limb Girdle muscular dystrophy (LGMD2C) characterized by late age of onset, proximal muscle weakness leading to disability, high creatine kinase values, normal intelligence and normal dystrophin in muscle biopsy. We have shown previously that three DLMD families from Tunisia are linked to chromosome 13q12. To further localize the LGMD2C gene, we have investigated seven additional families (119 individuals). Both genotyping and two-point linkage analysis were performed as described elsewhere. 7 refs., 1 fig., 1 tab.

  1. Linking Service Learning & Standards.

    ERIC Educational Resources Information Center

    Degelman, Charles, Ed.

    2000-01-01

    This theme issue explores the connection between service learning and standards-based education. In the lead article, "Service Learning and Standards: Are They Compatible?" (Brian Loney), an educator applies his extensive experience with Active Citizenship Today, a successful social studies service-learning program, to a representative set of…

  2. Hypertension`s lead connection: Does low-level exposure to lead cause high blood pressure?

    SciTech Connect

    Fackelmann, K.

    1996-06-15

    {open_quotes}Paying for the sins of the past.{close_quotes} is how researcher Howard Hu describes a proposed disease process in which lead stored for decades in the skeleton puts people at risk of high blood pressure. Previous research has linked this silvery white, poisonous metal to a host of ill effects in children, including learning disabilities, behavior problems, and brain damage. Now, Hu`s study indicates that past exposure may be causing today`s high blood pressure. If he`s right, the public health impact would be significant. {open_quotes}Tens of millions of Americans have been exposed over the years to lead,{close_quotes} says Philip J. Landrigan of Mount Sinai Medical Center in New York. {open_quotes}Adults today grew up at a time when we were still putting several hundred thousand tons of lead into gasoline each year.{close_quotes} Indeed, the men who developed high blood pressure during the recent study had in their bones lead concentrations, or lead burdens, that came from decades of everyday exposure. Such exposures resulted principally from breathing in fumes from leaded gasoline, drinking tap water from lead pipes or pipes soldered with lead, and inhaling or ingesting lead-laced paint dust or chips. This article goes on to discuss other studies and questions which still need to be answered.

  3. Growth Factors Cross-Linked to Collagen Microcarriers Promote Expansion and Chondrogenic Differentiation of Human Mesenchymal Stem Cells.

    PubMed

    Bertolo, Alessandro; Arcolino, Fanny; Capossela, Simona; Taddei, Anna Rita; Baur, Martin; Pötzel, Tobias; Stoyanov, Jivko

    2015-10-01

    Tissue engineering is a field in progressive expansion and requires constant updates in methods and devices. One of the central fields is the development of biocompatible, biodegradable, and injectable scaffolds, such as collagen microcarriers. To enhance cell attachment and produce a cost-effective cell culture solution with local stimulation of cells, basic fibroblast growth factor (bFGF) or transforming growth factor-β1 (TGF-β1) was covalently immobilized on microcarriers either by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) or riboflavin/UV (RB/UV) light-mediated cross-linking. Collagen microcarriers cross-linked with bFGF or TGF-β1 were used for expansion and chondrogenic differentiation of human mesenchymal stem cells (MSCs). Evaluation methods included cell viability test, chondrogenic marker expression (aggrecan and collagen type I and type II), histological detection of proteoglycans, and immunohistochemical analysis. Cross-linking strengthened the collagen structure of the microcarriers and reduced collagenase-mediated degradation. MSCs effectively proliferated on microcarriers cross-linked with bFGF, especially by EDC/NHS cross-linking. Chondrogenic differentiation of MSCs was induced by TGF-β1 cross-linked on microcarriers, promoting gene expression and protein accumulation of aggrecan and collagen type I and type II, as well as proteoglycans. Cross-linking by RB/UV enhanced chondrogenesis more than any other group. In addition, cross-linking reduced scaffold shrinkage exerted by MSCs during chondrogenesis, a desirable feature for microcarriers if used as tissue defect filler. In conclusion, cross-linking of bFGF or TGF-β1 to collagen microcarriers supported in vitro proliferation and chondrogenesis, respectively. If translated in vivo and in clinical practice, such approach might lead a step closer to development of a cost-effective and locally acting device for cell-based therapy. PMID:26222829

  4. Drugs + HIV, Learn the Link

    MedlinePlus

    ... Children & Teens Search Connect with NIDA : Google Plus Facebook LinkedIn Twitter YouTube Flickr RSS Menu Home Drugs ... HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 –Ongoing Behaviors associated with drug abuse ...

  5. Biochemical properties of bioplastics made from wheat gliadins cross-linked with cinnamaldehyde.

    PubMed

    Balaguer, M Pau; Gómez-Estaca, Joaquín; Gavara, Rafael; Hernandez-Munoz, Pilar

    2011-12-28

    The aim of this work has been to study the modification of gliadin films with cinnamaldehyde as a potential cross-linker agent. The molecular weight profile and cross-linking density showed that cinnamaldehyde increased reticulation in the resulting films. The participation of free amino groups of the protein in the newly created entanglements could be a possible mechanism of connection between the polypeptidic chains. The combination of a Schiff base and a Michael addition is a feasible approach to understanding this mechanism. The protein solubility in different media pointed to lower participation by both noncovalent and disulfide bonds in stabilizing the structure of the cross-linked films. The new covalent bonds formed by the cinnamaldehyde treatment hampered water absorption and weight loss, leading to more water-resistant matrices which had not disintegrated after 5 months. The properties of this novel bioplastic could be modified to suit the intended application by using cinnamaldehyde, a naturally occurring compound.

  6. Biochemical properties of bioplastics made from wheat gliadins cross-linked with cinnamaldehyde.

    PubMed

    Balaguer, M Pau; Gómez-Estaca, Joaquín; Gavara, Rafael; Hernandez-Munoz, Pilar

    2011-12-28

    The aim of this work has been to study the modification of gliadin films with cinnamaldehyde as a potential cross-linker agent. The molecular weight profile and cross-linking density showed that cinnamaldehyde increased reticulation in the resulting films. The participation of free amino groups of the protein in the newly created entanglements could be a possible mechanism of connection between the polypeptidic chains. The combination of a Schiff base and a Michael addition is a feasible approach to understanding this mechanism. The protein solubility in different media pointed to lower participation by both noncovalent and disulfide bonds in stabilizing the structure of the cross-linked films. The new covalent bonds formed by the cinnamaldehyde treatment hampered water absorption and weight loss, leading to more water-resistant matrices which had not disintegrated after 5 months. The properties of this novel bioplastic could be modified to suit the intended application by using cinnamaldehyde, a naturally occurring compound. PMID:22047158

  7. Optimization and small-amplitude analysis of Purcell's three-link microswimmer model

    NASA Astrophysics Data System (ADS)

    Wiezel, O.; Or, Y.

    2016-08-01

    This work studies the motion of Purcell's three-link microswimmer in viscous flow, by using perturbation expansion of its dynamics under small-amplitude strokes. Explicit leading-order expressions and next-order correction terms for the displacement of the swimmer are obtained for the cases of a square or circular gait in the plane of joint angles. The correction terms demonstrate the reversal in movement direction for large stroke amplitudes, which has previously only been shown numerically. In addition, asymptotic expressions for Lighthill's energetic efficiency are obtained for both gaits. These approximations enable calculating optimal stroke amplitudes and swimmer's geometry (i.e. ratio of links' lengths) for maximizing either net displacement or Lighthill's efficiency.

  8. Teaching Is Leading

    ERIC Educational Resources Information Center

    Collay, Michelle

    2013-01-01

    Most people think of a teacher leader as someone who takes on additional roles outside the classroom. But in this article, Michelle Collay argues that all effective teaching requires leadership. Using examples from classroom teachers with whom she has worked, Collay describes four dimensions of powerful classroom-based leadership: (1) teaching…

  9. Leading change: 2--planning.

    PubMed

    Kerridge, Joanna

    National initiatives have outlined the importance of involving frontline staff in service improvement, and the ability to influence and manage change has been identified as an essential skill for delivering new models of care. Nurses often have to take the lead in managing change in clinical practice. The second in a three-part series is designed to help nurses at all levels develop the knowledge and skills to function as change agents within their organisations. This article focuses on planning the change and dealing with resistance. PMID:22439509

  10. Leading Change, Adding Value.

    PubMed

    Evans, Nick

    2016-09-12

    Essential facts Leading Change, Adding Value is NHS England's new nursing and midwifery framework. It is designed to build on Compassion in Practice (CiP), which was published 3 years ago and set out the 6Cs: compassion, care, commitment, courage, competence and communication. CiP established the values at the heart of nursing and midwifery, while the new framework sets out how staff can help transform the health and care sectors to meet the aims of the NHS England's Five Year Forward View. PMID:27615573

  11. Predicting missing links and identifying spurious links via likelihood analysis

    PubMed Central

    Pan, Liming; Zhou, Tao; Lü, Linyuan; Hu, Chin-Kun

    2016-01-01

    Real network data is often incomplete and noisy, where link prediction algorithms and spurious link identification algorithms can be applied. Thus far, it lacks a general method to transform network organizing mechanisms to link prediction algorithms. Here we use an algorithmic framework where a network’s probability is calculated according to a predefined structural Hamiltonian that takes into account the network organizing principles, and a non-observed link is scored by the conditional probability of adding the link to the observed network. Extensive numerical simulations show that the proposed algorithm has remarkably higher accuracy than the state-of-the-art methods in uncovering missing links and identifying spurious links in many complex biological and social networks. Such method also finds applications in exploring the underlying network evolutionary mechanisms. PMID:26961965

  12. Predicting missing links and identifying spurious links via likelihood analysis

    NASA Astrophysics Data System (ADS)

    Pan, Liming; Zhou, Tao; Lü, Linyuan; Hu, Chin-Kun

    2016-03-01

    Real network data is often incomplete and noisy, where link prediction algorithms and spurious link identification algorithms can be applied. Thus far, it lacks a general method to transform network organizing mechanisms to link prediction algorithms. Here we use an algorithmic framework where a network’s probability is calculated according to a predefined structural Hamiltonian that takes into account the network organizing principles, and a non-observed link is scored by the conditional probability of adding the link to the observed network. Extensive numerical simulations show that the proposed algorithm has remarkably higher accuracy than the state-of-the-art methods in uncovering missing links and identifying spurious links in many complex biological and social networks. Such method also finds applications in exploring the underlying network evolutionary mechanisms.

  13. Predicting missing links and identifying spurious links via likelihood analysis.

    PubMed

    Pan, Liming; Zhou, Tao; Lü, Linyuan; Hu, Chin-Kun

    2016-01-01

    Real network data is often incomplete and noisy, where link prediction algorithms and spurious link identification algorithms can be applied. Thus far, it lacks a general method to transform network organizing mechanisms to link prediction algorithms. Here we use an algorithmic framework where a network's probability is calculated according to a predefined structural Hamiltonian that takes into account the network organizing principles, and a non-observed link is scored by the conditional probability of adding the link to the observed network. Extensive numerical simulations show that the proposed algorithm has remarkably higher accuracy than the state-of-the-art methods in uncovering missing links and identifying spurious links in many complex biological and social networks. Such method also finds applications in exploring the underlying network evolutionary mechanisms. PMID:26961965

  14. Predicting missing links and identifying spurious links via likelihood analysis.

    PubMed

    Pan, Liming; Zhou, Tao; Lü, Linyuan; Hu, Chin-Kun

    2016-03-10

    Real network data is often incomplete and noisy, where link prediction algorithms and spurious link identification algorithms can be applied. Thus far, it lacks a general method to transform network organizing mechanisms to link prediction algorithms. Here we use an algorithmic framework where a network's probability is calculated according to a predefined structural Hamiltonian that takes into account the network organizing principles, and a non-observed link is scored by the conditional probability of adding the link to the observed network. Extensive numerical simulations show that the proposed algorithm has remarkably higher accuracy than the state-of-the-art methods in uncovering missing links and identifying spurious links in many complex biological and social networks. Such method also finds applications in exploring the underlying network evolutionary mechanisms.

  15. Sirtuins Link Inflammation and Metabolism.

    PubMed

    Vachharajani, Vidula T; Liu, Tiefu; Wang, Xianfeng; Hoth, Jason J; Yoza, Barbara K; McCall, Charles E

    2016-01-01

    Sirtuins (SIRT), first discovered in yeast as NAD+ dependent epigenetic and metabolic regulators, have comparable activities in human physiology and disease. Mounting evidence supports that the seven-member mammalian sirtuin family (SIRT1-7) guard homeostasis by sensing bioenergy needs and responding by making alterations in the cell nutrients. Sirtuins play a critical role in restoring homeostasis during stress responses. Inflammation is designed to "defend and mend" against the invading organisms. Emerging evidence supports that metabolism and bioenergy reprogramming direct the sequential course of inflammation; failure of homeostasis retrieval results in many chronic and acute inflammatory diseases. Anabolic glycolysis quickly induced (compared to oxidative phosphorylation) for ROS and ATP generation is needed for immune activation to "defend" against invading microorganisms. Lipolysis/fatty acid oxidation, essential for cellular protection/hibernation and cell survival in order to "mend," leads to immune repression. Acute/chronic inflammations are linked to altered glycolysis and fatty acid oxidation, at least in part, by NAD+ dependent function of sirtuins. Therapeutically targeting sirtuins may provide a new class of inflammation and immune regulators. This review discusses how sirtuins integrate metabolism, bioenergetics, and immunity during inflammation and how sirtuin-directed treatment improves outcome in chronic inflammatory diseases and in the extreme stress response of sepsis. PMID:26904696

  16. Sirtuins Link Inflammation and Metabolism

    PubMed Central

    Vachharajani, Vidula T.; Liu, Tiefu; Wang, Xianfeng; Hoth, Jason J.; Yoza, Barbara K.; McCall, Charles E.

    2016-01-01

    Sirtuins (SIRT), first discovered in yeast as NAD+ dependent epigenetic and metabolic regulators, have comparable activities in human physiology and disease. Mounting evidence supports that the seven-member mammalian sirtuin family (SIRT1–7) guard homeostasis by sensing bioenergy needs and responding by making alterations in the cell nutrients. Sirtuins play a critical role in restoring homeostasis during stress responses. Inflammation is designed to “defend and mend” against the invading organisms. Emerging evidence supports that metabolism and bioenergy reprogramming direct the sequential course of inflammation; failure of homeostasis retrieval results in many chronic and acute inflammatory diseases. Anabolic glycolysis quickly induced (compared to oxidative phosphorylation) for ROS and ATP generation is needed for immune activation to “defend” against invading microorganisms. Lipolysis/fatty acid oxidation, essential for cellular protection/hibernation and cell survival in order to “mend,” leads to immune repression. Acute/chronic inflammations are linked to altered glycolysis and fatty acid oxidation, at least in part, by NAD+ dependent function of sirtuins. Therapeutically targeting sirtuins may provide a new class of inflammation and immune regulators. This review discusses how sirtuins integrate metabolism, bioenergetics, and immunity during inflammation and how sirtuin-directed treatment improves outcome in chronic inflammatory diseases and in the extreme stress response of sepsis. PMID:26904696

  17. Multilevel DC link inverter

    DOEpatents

    Su, Gui-Jia

    2003-06-10

    A multilevel DC link inverter and method for improving torque response and current regulation in permanent magnet motors and switched reluctance motors having a low inductance includes a plurality of voltage controlled cells connected in series for applying a resulting dc voltage comprised of one or more incremental dc voltages. The cells are provided with switches for increasing the resulting applied dc voltage as speed and back EMF increase, while limiting the voltage that is applied to the commutation switches to perform PWM or dc voltage stepping functions, so as to limit current ripple in the stator windings below an acceptable level, typically 5%. Several embodiments are disclosed including inverters using IGBT's, inverters using thyristors. All of the inverters are operable in both motoring and regenerating modes.

  18. Linked Gravitational Radiation

    NASA Astrophysics Data System (ADS)

    Thompson, Amy; Swearngin, Joseph; Wickes, Alexander; Willem Dalhuisen, Jan; Bouwmeester, Dirk

    2013-04-01

    The electromagnetic knot is a topologically nontrivial solution to the vacuum Maxwell equations with the property that any two field lines belonging to either the electric, magnetic, or Poynting vector fields are closed and linked exactly once [1]. The relationship between the vacuum Maxwell and linearized Einstein equations, as expressed in the form of the spin-N massless field equations, suggests that gravitational radiation possesses analogous topologically nontrivial field configurations. Using twistor methods we find the analogous spin-2 solutions of Petrov types N, D, and III. Aided by the concept of tendex and vortex lines as recently developed for the physical interpretation of solutions in general relativity [2], we investigate the physical properties of these knotted gravitational fields by characterizing the topology of their associated tendex and vortex lines.[4pt] [1] Ranada, A. F. and Trueba, J. L., Mod. Nonlinear Opt. III, 119, 197 (2002).[2] Nichols, D. A., et al., Phys. Rev. D, 84 (2011).

  19. Displacement enzyme linked aptamer assay.

    PubMed

    Baldrich, Eva; Acero, Josep Lluis; Reekmans, Gunter; Laureyn, Wim; O'Sullivan, Ciara K

    2005-08-01

    labeled target) were elucidated, and the results demonstrated their amenability to long-term storage, facilitating commercially viable displacement enzyme-linked aptamer assays that simply require sample addition, with a total assay time, including color development, of 30 min.

  20. Nutrition and lead: Strategies for public health

    SciTech Connect

    Mahaffey, K.R.

    1995-09-01

    Over the past two decades, blood lead levels among U.S. children have been reduced by approximately 80%. This decline reflects both primary interventions (removal of lead solder form food beverage cans and virtual elimination of lead additives form gasoline) and secondary prevention strategies (public health programs and nutritional intervention). Nonetheless, pediatric lead poisoning (i.e., blood lead concentrations {ge} 10 {mu}g/dl) continues to occur in 8.9% of 1- to 5-year-old children. Currently, blood lead concentrations exceed the U.S. Centers for Disease Control`s targeted value (10 {mu}g/dl), most often among minority and low-income populations. These same subpopulations are at greatest risk of marginal nutrition status (especially for iron and calcium), which increases their susceptibility to lead toxicity. Adverse child feeding practices (e.g., irregular temporal patterns of food intake) are also of concern among the subpopulations at highest risk to excessive lead from external or environmental dose to internal dose as reflected by blood lead concentration. 60 refs.

  1. NASA OSMA NDE Program Additive Manufacturing Foundational Effort

    NASA Technical Reports Server (NTRS)

    Waller, Jess; Walker, James; Burke, Eric; Wells, Douglas; Nichols, Charles

    2016-01-01

    NASA is providing key leadership in an international effort linking NASA and non-NASA resources to speed adoption of additive manufacturing (AM) to meet NASA's mission goals. Participants include industry, NASA's space partners, other government agencies, standards organizations and academia. Nondestructive Evaluation (NDE) is identified as a universal need for all aspects of additive manufacturing.

  2. OPTI - OPTICAL COMMUNICATIONS LINK ANALYSIS PROGRAM

    NASA Technical Reports Server (NTRS)

    Marshall, W. K.

    1994-01-01

    The Optical Communication Link Analysis Program, OPTI, analyzes optical and near-infrared communication links that use pulse position modulation (PPM) and direct detection. The program prompts for inputs of system component parameters, modulation format and other operational parameters, background noise sources, and the desired link bit error rate. From these inputs, link margin is determined and a link design control table (DCT) is generated. The program also allows the user to save sets of input parameters defining a given link and read them back into the program at a later time. Further, the program has the capability of altering automatically any of the input parameters to achieve a desired link margin. The program provides a table of extended background sources, e.g. planets, the moon, and the sun. To compute background noise, only the distance from the receiver to the noise source(s) must be entered. This determines whether or not the whole object is in the field-of-view. The program assumes that each object is a blackbody (at 5900K) with an overall visible magnitude scaled to match the tabulated data. Also provided is a table of 19 bright stars. If the noise source is one or several of these, then only the name(s) of the star(s) are required. Noise sources that are not among those contained in the program can be entered as "additional noise sources". In this case required information includes whether or not the source is a point or extended source, its radiance (for extended sources) or irradiance, and receiver to source distance in A.U. (for point sources). The OPTI program is written in FORTRAN-77 and was designed to be used on the IBM PC and PC/AT personal computers. (Note: The 8087/80287 math coprocessor option is highly recommended for use with this program.) The program will also compile under UNIX 4.3 BSD FORTRAN-77 with minor changes. OPTI was developed in 1987.

  3. Lead isotopes as a supplementary tool in the routine evaluation of household lead hazards.

    PubMed Central

    Gwiazda, R H; Smith, D R

    2000-01-01

    The advent of magnetic sector inductively coupled plasma-mass spectrometry (ICP-MS) allows rapid, accurate, and precise measurement of lead isotopes in environmental and biological samples at a lower cost than traditional methods. This may increase the feasibility of including lead isotope measurements as a routine tool to identify household sources of lead exposure to children. Here, we present three household case studies to illustrate how lead hazard evaluations by an environmental specialist could be supplemented with routine lead isotope analyses of potential lead sources and blood. Sampling for lead isotopes was undertaken following the U.S. Department of Housing and Urban Development regulatory guidelines for the evaluation of lead hazards in housing, and with the consideration of minimizing the additional costs associated with lead isotope measurements. The range of isotopic ratios within a single residence was large enough to allow the characterization of different lead sources, particularly when both major (e.g., (207)Pb/(206)Pb) and minor (e.g., (206)Pb/(204)Pb) isotope ratios were considered. These cases illustrate the utility of the lead isotope method to identify main source(s) of lead exposure to the child; discard unlikely sources of exposure to the child; point to sources of lead to dust; and substantiate or refine the environmental assessment based exclusively on lead concentrations and loadings. Thus, a more effective evaluation of household lead hazards would likely benefit from considering a) lead concentrations and loadings in and around the household environment; b) all isotopic ratios of potential lead sources within that environment; and c) information about behavioral habits, as well as an evaluation of viable pathways of exposure to the child. PMID:11102302

  4. Lead isotopes as a supplementary tool in the routine evaluation of household lead hazards.

    PubMed

    Gwiazda, R H; Smith, D R

    2000-11-01

    The advent of magnetic sector inductively coupled plasma-mass spectrometry (ICP-MS) allows rapid, accurate, and precise measurement of lead isotopes in environmental and biological samples at a lower cost than traditional methods. This may increase the feasibility of including lead isotope measurements as a routine tool to identify household sources of lead exposure to children. Here, we present three household case studies to illustrate how lead hazard evaluations by an environmental specialist could be supplemented with routine lead isotope analyses of potential lead sources and blood. Sampling for lead isotopes was undertaken following the U.S. Department of Housing and Urban Development regulatory guidelines for the evaluation of lead hazards in housing, and with the consideration of minimizing the additional costs associated with lead isotope measurements. The range of isotopic ratios within a single residence was large enough to allow the characterization of different lead sources, particularly when both major (e.g., (207)Pb/(206)Pb) and minor (e.g., (206)Pb/(204)Pb) isotope ratios were considered. These cases illustrate the utility of the lead isotope method to identify main source(s) of lead exposure to the child; discard unlikely sources of exposure to the child; point to sources of lead to dust; and substantiate or refine the environmental assessment based exclusively on lead concentrations and loadings. Thus, a more effective evaluation of household lead hazards would likely benefit from considering a) lead concentrations and loadings in and around the household environment; b) all isotopic ratios of potential lead sources within that environment; and c) information about behavioral habits, as well as an evaluation of viable pathways of exposure to the child.

  5. Peltier Current Leads with conical configuration

    NASA Astrophysics Data System (ADS)

    Hakimi, I.; Nikulshin, Y.; Wolfus, S.; Yeshurun, Y.

    2016-04-01

    Current leads in cryogenic systems are a major heat source which eventually affects the entire system. It has been shown in recent years that Peltier elements are useful in reducing incoming heat into the cold system. In this article we present a new tapered cone-like configuration of the Peltier Current Leads which increases the power saving. This configuration is compared to the standard cylindrical configuration utilizing advanced ANSYS simulations. The simulations show an additional power saving of 4% when using the tapered lead configuration.

  6. Lead-free solder

    DOEpatents

    Anderson, Iver E.; Terpstra, Robert L.

    2001-05-15

    A Sn--Ag--Cu eutectic alloy is modified with one or more low level and low cost alloy additions to enhance high temperature microstructural stability and thermal-mechanical fatigue strength without decreasing solderability. Purposeful fourth or fifth element additions in the collective amount not exceeding about 1 weight % (wt. %) are added to Sn--Ag--Cu eutectic solder alloy based on the ternary eutectic Sn--4.7%Ag--1.7%Cu (wt. %) and are selected from the group consisting essentially of Ni, Fe, and like-acting elements as modifiers of the intermetallic interface between the solder and substrate to improve high temperature solder joint microstructural stability and solder joint thermal-mechanical fatigue strength.

  7. Lead-acid battery construction

    NASA Technical Reports Server (NTRS)

    Rowlette, John J. (Inventor)

    1988-01-01

    The power characteristics of a lead-acid battery are improved by incorporating a dispersion of 1 to 10% by weight of a thermodynamically stable conductivity additive, such as conductive tin oxide coated glass fibers (34) of filamentary glass wool (42) in the positive active layer (32) carried on the grid (30) of the positive plate (16). The avoiding of positive plate reversal to prevent reduction of the tin oxide is accomplished by (a) employing an oversized positive plate and pre-charging it; (b) by pre-discharging the negative plate; and/or (c) by placing a circuit breaker (26) in combination with the plates (16, 18) and terminals (22, 24) to remove the load when the voltage of the positive plate falls below a pre-selected level.

  8. Diesel fuel detergent additive performance and assessment

    SciTech Connect

    Vincent, M.W.; Papachristos, M.J.; Williams, D.; Burton, J.

    1994-10-01

    Diesel fuel detergent additives are increasingly linked with high quality automotive diesel fuels. Both in Europe and in the USA, field problems associated with fuel injector coking or fouling have been experienced. In Europe indirect injection (IDI) light duty engines used in passenger cars were affected, while in the USA, a direct injection (DI) engine in heavy duty truck applications experienced field problems. In both cases, a fuel additive detergent performance test has evolved using an engine linked with the original field problem, although engine design modifications employed by the manufacturers have ensured improved operation in service. Increasing awareness of the potential for injector nozzle coking to cause deterioration in engine performance is coupled with a need to meet ever more stringent exhaust emissions legislation. These two requirements indicate that the use of detergency additives will continue to be associated with high quality diesel fuels. The paper examines detergency performance evaluated in a range of IDI and DI engines and correlates performance in the two most widely recognised test engines, namely the Peugeot 1.9 litre IDI, and Cummins L10 DI engines. 17 refs., 18 figs., 5 tabs.

  9. The influence of bone and blood lead on plasma lead levels in environmentally exposed adults.

    PubMed Central

    Hernández-Avila, M; Smith, D; Meneses, F; Sanin, L H; Hu, H

    1998-01-01

    There is concern that previously accumulated bone lead stores may constitute an internal source of exposure, particularly during periods of increased bone mineral loss (e.g., pregnancy, lactation, and menopause). Furthermore, the contribution of lead mobilized from bone to plasma may not be adequately reflected by whole-blood lead levels. This possibility is especially alarming because plasma is the main circulatory compartment of lead that is available to cross cell membranes and deposit in soft tissues. We studied 26 residents of Mexico City who had no history of occupational lead exposure. Two samples of venous blood were collected from each individual. One sample was analyzed by inductively coupled plasma-magnetic sector mass spectrometry for whole-blood lead levels. The other sample was centrifuged to separate plasma, which was then isolated and analyzed for lead content by the same analytical technique. Bone lead levels in the tibia and patella were determined with a spot-source 109Cd K-X-ray fluorescence instrument. Mean lead concentrations were 0.54 microg/l in plasma, 119 microg/l in whole blood, and 23.27 and 11.71 microg/g bone mineral in the patella and tibia, respectively. The plasma-to-whole-blood lead concentration ratios ranged from 0.27% to 0.70%. Whole-blood lead level was highly correlated with plasma lead level and accounted for 95% of the variability of plasma lead concentrations. Patella and tibia lead levels were also highly correlated with plasma lead levels. The bivariate regression coefficients of patella and tibia on plasma lead were 0.034 (p<0. 001) and 0.053 (p<0.001), respectively. In a multivariate regression model of plasma lead levels that included whole-blood lead, patella lead level remained an independent predictor of plasma lead level (ss = 0.007, p<0.001). Our data suggest that although whole-blood lead levels are highly correlated with plasma lead levels, lead levels in bone (particularly trabecular bone) exert an additional

  10. Biogeochemistry and cycling of lead.

    PubMed

    Shotyk, William; Le Roux, Gaël

    2005-01-01

    Lead has no biological function and is one of the most toxic metals. At the same time, it is one of the most useful, and perhaps no other metal has found such a wide range of industrial applications. It has been used extensively since Antiquity, which is when environmental Pb contamination began. With respect to contamination since industrialization, peat bogs and polar ice show that coal combustion and industrial emissions were as important during the first half of the 20th century as gasoline lead was during the second half. Air Pb concentrations have generally declined since the introduction of pollution control technologies and the gradual elimination of leaded gasoline additives. However, all of the most recent published studies of the isotopic composition of Pb in aerosols and archival samples show that anthropogenic sources continue to dominate the atmospheric Pb flux by a considerable margin. The health effects of childhood Pb exposure is a growing concern, as deleterious effects are seen at BLL well below those currently believed to be safe, and safe levels are one or two orders of magnitude above the estimated natural values. Mobilization of Pb-rich particles from highly contaminated soils in urban areas is an on-going health concern for many large cities. Even in areas far removed from industrial emission sources, Pb concentrations in the surface soil layers are far above their natural concentration range. In acidic forest soils, Pb concentrations are not only elevated in the biologically active zone, but also in their corresponding pore fluids. Accurate and precise measurements of the isotopic composition of Pb employing appropriate clean lab protocols, will continue to advance our understanding of the fate of Pb in the environment and its impact on human and ecosystem health.

  11. Blood Test: Lead (For Parents)

    MedlinePlus

    ... and when based on a child's risk for lead poisoning. Those who are considered at risk — such as ... How Do I Get My Child Tested for Lead Poisoning? Lead Poisoning Pica Getting a Blood Test (Video) ...

  12. Lead (Environmental Health Student Portal)

    MedlinePlus

    ... have lead in them The good news about lead poisoning is that it’s 100% preventable. That means we ... damage the brain, and may even cause death. Lead poisoning can also cause: Anemia (when your blood doesn’ ...

  13. Leading from the boardroom.

    PubMed

    Lorsch, Jay W; Clark, Robert C

    2008-04-01

    These days, boards are working overtime to comply with Sarbanes-Oxley and other governance requirements meant to protect shareholders from executive wrongdoing. But as directors have become more hands-on with compliance, they've become more hands-off with long-range planning. That exposes corporations and their shareholders to another--perhaps even greater--risk, say professors Lorsch, of Harvard Business School, and Clark, of Harvard Law School. Boards are giving the long term short shrift for a number of reasons. Despite much heavier workloads, directors haven't rethought their patterns of operating - their meetings, committees, and other interactions. Compliance has changed their relationship with executives, however, turning directors into micromanagers who closely probe executives' actions instead of providing high-level guidance. Meanwhile, the pressure to meet quarterly expectations intensifies. Directors need to do a better job of balancing compliance with forward thinking. Boardroom effectiveness hinges most on the quality of directors and their interactions, the authors' research shows. Directors must apply their wisdom broadly, handling compliance work more efficiently and staying out of the weeds on strategic issues. Using their power with management to evangelize for long-term planning, they must take the lead on discussions about financial infrastructure, talent development, and strategy. Reserving sacrosanct time for such discussions, as Philips Electronics' board does at annual retreats, is an effective practice: After one recent retreat, Philips decided to exit the semiconductor business, where it was losing ground. Individual directors also must not shy away from asking tough questions and acting as catalysts on critical issues, such as grooming a successor to the CEO. In short, directors must learn to lead from the boardroom.

  14. Linking Science and Literacy

    ERIC Educational Resources Information Center

    Plummer, Donna M.; Davis, Betty Jo; Brazier, Victoria

    2011-01-01

    We successfully integrated science and language arts in a third-grade classroom. The students used "scientist's eyes" and "poet's eyes" to write original poetry. In addition, they created habitat posters about a swamp organism. Scoring guides for the habitat poems and posters are also included. (Contains 5 figures and 2 tables.)

  15. Linking LEGO and Algebra

    ERIC Educational Resources Information Center

    Özgün-Koca, S. Asli; Edwards, Thomas G.; Chelst, Kenneth R.

    2015-01-01

    In mathematics, students should represent, model, and work with such real-world situations as those found in the physical world, the public policy realm, and society (CCSSI 2010). Additionally, students need to make decisions and be flexible enough to improve their decisions after analyzing realistic situations. The LEGO® Pets activity does just…

  16. Ways women lead.

    PubMed

    Rosener, J B

    1990-01-01

    Women managers are succeeding not by adopting the traditional command-and-control leadership style but by drawing on what is unique to their experience as women. According to a study the author conducted for the International Women's Forum, men and women in similar managerial jobs make the same amount of money and experience roughly the same degree of work-family conflict. But when they describe their leadership styles, vast differences arise. Men are much more likely than women to view leadership as a series of transactions with subordinates, and to use their position and control of resources to motivate their followers. Women, on the other hand, are far more likely than men to describe themselves as transforming subordinates' self-interest into concern for the whole organization and as using personal traits like charisma, work record, and interpersonal skills to motivate others. Women leaders practice what the author calls "interactive leadership"--trying to make every interaction with coworkers positive for all involved by encouraging participation, sharing power and information, making people feel important, and energizing them. In general, women have been expected to be supportive and cooperative, and they have not held long series of positions with formal authority. This may explain why women leaders today tend to be more interactive than men. But interactive leadership should not be linked directly to being female, since some men use that style and some women prefer the command-and-control style. Organizations that are open to leadership styles that play to individuals' strengths will increase their chances of surviving in a fast-changing environment.

  17. Assessment of lead in cosmetic products.

    PubMed

    Al-Saleh, Iman; Al-Enazi, Sami; Shinwari, Neptune

    2009-07-01

    There have been a number of recent reports in the media and on the internet about the presence of lead in brand-names lipsticks. This has drawn our attention to assess the safety of various cheap brands of cosmetics sold at 2-riyals stores in Saudi market that are imported from countries where safety regulations are poorly enforced as well as they lack perfect conditions for manufacturing. Lead contents were determined in 26 and eight different brands of lipsticks and eye shadows using the Zeeman atomic absorption spectrophotometer coupled to graphite tube atomizer after an acid digestion procedure. Lead was detected in all the studied samples. The median (25th-75th percentile) lead content in 72 lipsticks samples was 0.73 (0.49-1.793) PPM wet wt. in the range of 0.27-3760 PPM wet wt. There were four brands of lipsticks with lead content above the FDA lead limit as impurities in color additives (20 PPM). The FDA does not set a limit for lead in lipstick. Three of them were extremely high points and considered outliers. The median (25th-75th percentile) lead contents in pressed powder eye shadow was 1.38 (0.944-1.854) PPM wet wt. (n=22) in the range of 0.42-58.7 PPM wet wt. One brand was above 20 PPM the US FDA's lead limit as impurities. The overall results indicate that lead in lipsticks and eye shadows are below the FDA lead limit as impurities and, thus, probably have no significant toxicological effects. Nevertheless, few brands had lead content above 20 PPM that might put consumers at the risk of lead poisoning. Lead is a cumulative, and applying lead-containing cosmetics several times a day or every day, can potentially add up to significant exposure levels. Pregnant and nursing mothers are vulnerable population because lead passes through placenta and human milk and affect fetus or infant's developments. Our findings call for an immediate mandatory regular testing program to check lead and other toxic metals in lipsticks and other cosmetic products imported

  18. Assessment of lead in cosmetic products.

    PubMed

    Al-Saleh, Iman; Al-Enazi, Sami; Shinwari, Neptune

    2009-07-01

    There have been a number of recent reports in the media and on the internet about the presence of lead in brand-names lipsticks. This has drawn our attention to assess the safety of various cheap brands of cosmetics sold at 2-riyals stores in Saudi market that are imported from countries where safety regulations are poorly enforced as well as they lack perfect conditions for manufacturing. Lead contents were determined in 26 and eight different brands of lipsticks and eye shadows using the Zeeman atomic absorption spectrophotometer coupled to graphite tube atomizer after an acid digestion procedure. Lead was detected in all the studied samples. The median (25th-75th percentile) lead content in 72 lipsticks samples was 0.73 (0.49-1.793) PPM wet wt. in the range of 0.27-3760 PPM wet wt. There were four brands of lipsticks with lead content above the FDA lead limit as impurities in color additives (20 PPM). The FDA does not set a limit for lead in lipstick. Three of them were extremely high points and considered outliers. The median (25th-75th percentile) lead contents in pressed powder eye shadow was 1.38 (0.944-1.854) PPM wet wt. (n=22) in the range of 0.42-58.7 PPM wet wt. One brand was above 20 PPM the US FDA's lead limit as impurities. The overall results indicate that lead in lipsticks and eye shadows are below the FDA lead limit as impurities and, thus, probably have no significant toxicological effects. Nevertheless, few brands had lead content above 20 PPM that might put consumers at the risk of lead poisoning. Lead is a cumulative, and applying lead-containing cosmetics several times a day or every day, can potentially add up to significant exposure levels. Pregnant and nursing mothers are vulnerable population because lead passes through placenta and human milk and affect fetus or infant's developments. Our findings call for an immediate mandatory regular testing program to check lead and other toxic metals in lipsticks and other cosmetic products imported

  19. Influence of the modulation index of Mach-Zehnder modulator on intersatellite microwave photonics links with multiple RF signals

    NASA Astrophysics Data System (ADS)

    Zhu, Zihang; Zhao, Shanghong; Li, Yongjun; Chu, Xingchun; Hou, Rui

    2013-04-01

    A generalized intersatellite microwave photonics links model to study the influence of the modulation index of Mach-Zehnder modulator on the receiver sensitivity with multiple radio frequency (RF) signals is presented. An exact analytical solution of signal-to-noise and distortion ratio (SNDR) for optical double-sideband (ODSB) and optical single-sideband (OSSB) modulation is deduced with Bessel expansion and Graf's addition theorem. Numerical results show that the receiver sensitivity increases and then decreases as the increase in modulation index, there is an optimum modulation index that maximizes the receiver sensitivity and the larger channel numbers lead to lower receiver sensitivity for maintaining the SNDR at the desired level. In addition, ODSB modulation can be more attractive than OSSB modulation in intersatellite microwave photonics links, since the maximum receiver sensitivity for ODSB modulation is better than that for OSSB modulation.

  20. Adaptive Path Selection for Link Loss Inference in Network Tomography Applications

    PubMed Central

    Qiao, Yan; Jiao, Jun; Rao, Yuan; Ma, Huimin

    2016-01-01

    In this study, we address the problem of selecting the optimal end-to-end paths for link loss inference in order to improve the performance of network tomography applications, which infer the link loss rates from the path loss rates. Measuring the path loss rates using end-to-end probing packets may incur additional traffic overheads for networks, so it is important to select the minimum path set carefully while maximizing their performance. The usual approach is to select the maximum independent paths from the candidates simultaneously, while the other paths can be replaced by linear combinations of them. However, this approach ignores the fact that many paths always exist that do not lose any packets, and thus it is easy to determine that all of the links of these paths also have 0 loss rates. Not considering these good paths will inevitably lead to inefficiency and high probing costs. Thus, we propose an adaptive path selection method that selects paths sequentially based on the loss rates of previously selected paths. We also propose a theorem as well as a graph construction and decomposition approach to efficiently find the most valuable path during each round of selection. Our new method significantly outperforms the classical path selection method based on simulations in terms of the probing cost, number of accurate links determined, and the running speed. PMID:27701447

  1. Surface fabrication of hollow microspheres from N-methylated chitosan cross-linked with glutaraldehyde.

    PubMed

    Peng, Xianghong; Zhang, Lina

    2005-02-01

    We have successfully prepared biocompatible and biodegradable hollow microspheres with sizes between 2 and 5 mum using cyclohexane droplets as a template and the N-methylated chitosan (NMC) cross-linked with glutaraldehyde (GA) as the shell. The structure, morphology, and formation process of the hollow microspheres were characterized by FT-IR, (1)H and (13)C NMR, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results revealed that the microspheres exhibited a very smooth and hollow structure. This work confirmed that the hollow microspheres were accomplished by fabricating on the basis of chemical cross-linking on the surface of the emulsion droplets and by removing cyclohexane as core. The results from SEM and TEM indicated that the emulsion droplets covered with cross-linked NMC in the oil-in-water system aggregated together to form a precipitate of microspheres by coagulating with acetone. Moreover, the cross-linked NMC on the surface of the microspheres continuously cured to form the tight shell, whereas the inner area became a cavity with increase of the aging time, leading to the hollow microspheres. In addition, an anti-infective drug, ofloxacin (Floxin), encapsulated in the microspheres more rapidly released to reach 90 wt % at pH 7.4 within 8 h than at pH 1.2.

  2. Induction and repair of DNA cross-links induced by sulfur mustard in the A-549 cell line followed by a comet assay.

    PubMed

    Jost, Petr; Svobodova, Hana; Stetina, Rudolf

    2015-07-25

    Sulfur mustard is a highly toxic chemical warfare agent with devastating impact on intoxicated tissues. DNA cross-links are probably the most toxic DNA lesions induced in the cell by sulfur mustard. The comet assay is a very sensitive method for measuring DNA damage. In the present study using the A-549 lung cell line, the comet assay protocol was optimized for indirect detection of DNA cross-links induced by sulfur mustard. The method is based on the additional treatment of the assayed cells containing cross-links with the chemical mutagen, styrene oxide. Alkali-labile adducts of styrene oxide cause DNA breaks leading to the formation of comets. A significant dose-dependent reduction of DNA migration of the comet's tail was found after exposing cells to sulfur mustard, indicative of the amount of sulfur mustard induced cross-links. The remarkable decrease of % tail DNA could be observed as early as 5min following exposure to sulfur mustard and the maximal effect was found after 30min, when DNA migration was reduced to the minimum. Sulfur mustard preincubated in culture medium without cells lost its ability to induce cross-links and had a half-life of about 15min. Pre-incubation longer than 30min does not lead to a significant increase in cross-links when applied to cells. However, the amount of cross-links is decreased during further incubation due to repair. The current modification of the comet assay provides a useful tool for detecting DNA cross-links induced by sulfur mustard and could be used for detection of other DNA cross-linking agents such as chemotherapeutic drugs. PMID:25986970

  3. Induction and repair of DNA cross-links induced by sulfur mustard in the A-549 cell line followed by a comet assay.

    PubMed

    Jost, Petr; Svobodova, Hana; Stetina, Rudolf

    2015-07-25

    Sulfur mustard is a highly toxic chemical warfare agent with devastating impact on intoxicated tissues. DNA cross-links are probably the most toxic DNA lesions induced in the cell by sulfur mustard. The comet assay is a very sensitive method for measuring DNA damage. In the present study using the A-549 lung cell line, the comet assay protocol was optimized for indirect detection of DNA cross-links induced by sulfur mustard. The method is based on the additional treatment of the assayed cells containing cross-links with the chemical mutagen, styrene oxide. Alkali-labile adducts of styrene oxide cause DNA breaks leading to the formation of comets. A significant dose-dependent reduction of DNA migration of the comet's tail was found after exposing cells to sulfur mustard, indicative of the amount of sulfur mustard induced cross-links. The remarkable decrease of % tail DNA could be observed as early as 5min following exposure to sulfur mustard and the maximal effect was found after 30min, when DNA migration was reduced to the minimum. Sulfur mustard preincubated in culture medium without cells lost its ability to induce cross-links and had a half-life of about 15min. Pre-incubation longer than 30min does not lead to a significant increase in cross-links when applied to cells. However, the amount of cross-links is decreased during further incubation due to repair. The current modification of the comet assay provides a useful tool for detecting DNA cross-links induced by sulfur mustard and could be used for detection of other DNA cross-linking agents such as chemotherapeutic drugs.

  4. Relationship between lead mining and blood lead levels in children.

    PubMed

    Murgueytio, A M; Evans, R G; Sterling, D A; Clardy, S A; Shadel, B N; Clements, B W

    1998-01-01

    The authors studied blood lead levels of 226 randomly selected children, aged 6-92 mo, who lived in either a lead-mining area or a nonmining area, and 69 controls. The authors sought to determine to what extent mining activities contributed to blood lead levels in the children. The mean blood lead levels in the study and control groups were 6.52 microg/dl and 3.43 microg/dl, respectively. The corresponding proportions of children with elevated blood lead levels were 17% and 3%. Soil and dust lead levels were up to 10 times higher in the study than the control group. Elevated blood lead levels appeared to result from exposure to both lead-mining waste and lead-based paint. Mining waste was the cause of the higher prevalence of elevated blood lead levels in these children. PMID:9886161

  5. Linking to the Future

    NASA Astrophysics Data System (ADS)

    Moore, John W.

    1999-09-01

    my copy of JCE in the mail each month, and I expect you do too. I can glance at the cover to get an overview of an issue's content, and I usually am enticed inside by intriguing cover art. I can scan the table of contents to find articles I want to read, or I can just browse through the issue to see what looks interesting. Usually the editors have juxtaposed related articles so that I often find a small treasure trove. The printed Journal is quite portable and can be read in a car or airplane. It will last a long time, and until the paper deteriorates, I will never have a problem reading back issues. I have almost every issue from the first day I subscribed and have even added some older ones from collections of retired colleagues who no longer had shelf space for them. I certainly would not want to give up my printed copies, and I want to keep getting them. I find that JCE Online provides a different kind of resource that is equally valuable. It contains more information, and information that is more appropriate in electronic form. It links related ideas into a much more complex web of information than is possible in print. And it opens pathways to lots of information that is not part of JCE but resides elsewhere. Using this issue as an example, let's take a tour of what JCE Online can do.

    • Point your Web browser to http://jchemed.chem.wisc.edu
    • Click on Journal and then on Current Issue (unless September 1999 is no longer the current issue, in which case you will find it in Past Issues).
    • In the table of contents, find the article "UV Catalysis, Cyanotype Photography, and Sunscreens". Click on the title.
    • When the abstract appears, click on Full Text (PDF) to see the article, just as it appears on page 1199 in this issue.
    • When you are prompted, enter the name and subscriber number from your address label.
    • At the end of the article you will find that supplementary materials are available (including a procedure for testing

    • Surface characteristics of lead ice

      NASA Astrophysics Data System (ADS)

      Perovich, Donald K.; Richter-Menge, Jacqueline A.

      1994-08-01

      Under cold conditions, ice growth in a lead occurs rapidly, giving young sea ice a high bulk salinity. The surface characteristics of this ice type are dominated by a thin, highly saline surface skim and often by the formation of frost flowers. These surface characteristics are of particular interest because of their significant temporal variability and large impact on the electromagnetic properties of sea ice. As part of the Lead Experiment held during March and April of 1991 and 1992 in the Alaskan Beaufort Sea, ice properties and surface conditions typical of springtime leads were monitored at three sites during the initial few days of growth. Observations indicate that once the ice thickness reached approximately 2 cm, a thin (˜1 mm), highly saline (˜100 parts per thousand (ppt)) skim of brine formed on the surface. After only a few hours of growth the initially smooth surface of the sea ice developed some small-scale roughness. Frost flowers, the result of ice grown from the vapor phase, quickly formed on the surface of the sea ice and continued to develop during the observations. Depending on the temperature, the frost flowers were composed of various ice crystal types, including clumps, stellar dendrites, and needles. The initially fresh frost flowers quickly became salty, reaching salinities as high as 100 ppt. The salinity of both the frost flowers and the surface skim decreased at night as temperatures dropped and additional hoarfrost accumulated on the surface. These decreases were also due in part to the accumulation of snow on the surface of the leads. Combining these observations with simple calculations, possible mechanisms for the development and evolution of the surface skim and frost flowers are discussed. They include the hypothesis that the source of the surface skim is brine expelled upward from the sea ice as it cools, that the surface protrusions serve as nucleation sites for the frost flowers, and that the source of the excess water vapor

    • Lead Isotopes in Highway Runoff

      NASA Astrophysics Data System (ADS)

      Ferreira, M.; Lau, S.; Green, P. G.; Stenstrom, M. K.

      2011-12-01

      Lead (Pb) isotopes have been used extensively to study the provenance of lead pollution on air, water, and sediments. In this study, we measured Pb isotopes and Pb aqueous concentration in highway runoff in three west Los Angeles sites. Those three sites, part of a long-term study sponsored by the California Department of Transportation, represent small catchment areas, and host heavy traffic. In addition, there were no inputs of sand or salt to the highway because the sites are almost completely impervious and also due to the lack of snow to be controlled. Highway runoff from the three sites was collected for 7 storms during the 2004-2005 Winter. Grab samples were collected every 15 minutes during the first hour, and hourly afterwards. A total of 202 samples were collected and filtered into five size fractions (<0.45μm, 0.45-8μm, 8-20μm, 20-100μm, >100μm). Aqueous concentration of Pb range from 0.08μg/L to 46.95μg/L (7.98±10.89μg/L) and it is not correlated with any of the lead isotope ratios. The 208Pb/206Pb ratio ranges from 1.983 to 2.075 (2.024±0.026) and there is no statistical difference for the mean value of the 208Pb/206Pb ratio for the four particulate size fractions (0.45-8μm, 8-20μm, 20-100μm, >100μm). However, the 208Pb/206Pb ratio of nearby soils yield 2.060±0.021 and it is statistically different from the ratios obtained for the highway runoff. This hints that the lead present in highway runoff does not come from local soils. The 207Pb/206Pb ratio ranges from 0.804 to 0.847 (0.827±0.011) and there is no statistical difference for the mean value of the 207Pb/206Pb ratio for the four particulate size fractions (0.45-8μm, 8-20μm, 20-100μm, >100μm). Surprisingly, there is also no statistical difference with the 207Pb/206Pb ratio of nearby soils (0.833±0.009).

    • Managing lead-based paint abatement wastes

      SciTech Connect

      Steele, N.L.C.

      1994-12-31

      Renovation, remodeling, demolition, and surface preparation for painting, in addition to specified lead abatement, are all activities that have the potential to produce hazardous wastes if a property was painted with lead-based paint. Lead-based paint was used on residential structures until 1978, when most residential uses were banned by the Consumer Products Safety Council. Prior to the 1950s, paints for residential uses may have contained up to 50% lead by weight. Today, commercial and military paints may still contain lead and can be used on non-residential structures. The lead content of residential paints is limited to 0.06% lead (by weight) in the dried film. This paper provides an overview of some of the information needed to properly manage lead-based paint abatement wastes. The issues covered in this paper include waste classification, generator status, treatment, and land disposal restrictions. The author assumes that the reader is familiar with the provision of the Health and Safety Code and the California Code of Regulations that pertain to generation and management of hazardous wastes. Citations provided herein do not constitute an exhaustive list of all the regulations with which a generator of hazardous waste must comply.

    • Depression and the Link with Cardiovascular Disease

      PubMed Central

      Dhar, Arup K.; Barton, David A.

      2016-01-01

      This review provides an outline of the association between major depressive disorder (MDD) and coronary heart disease (CHD). Much is known about the two individual clinical conditions; however, it is not until recently, biological mechanisms have been uncovered that link both MDD and CHD. The activation of stress pathways have been implicated as a neurochemical mechanism that links MDD and CHD. Depression is known to be associated with poorer outcomes of CHD. Psychological factors, such as major depression and stress, are now known as risk factors for developing CHD, which is as important and is independent of classic risk factors, such as hypertension, diabetes mellitus, and cigarette smoking. Both conditions have great socioeconomic importance given that depression and CHD are likely to be two of the three leading causes of global burden of disease. Better understanding of the common causal pathways will help us delineate more appropriate treatments. PMID:27047396

    • Depression and the Link with Cardiovascular Disease.

      PubMed

      Dhar, Arup K; Barton, David A

      2016-01-01

      This review provides an outline of the association between major depressive disorder (MDD) and coronary heart disease (CHD). Much is known about the two individual clinical conditions; however, it is not until recently, biological mechanisms have been uncovered that link both MDD and CHD. The activation of stress pathways have been implicated as a neurochemical mechanism that links MDD and CHD. Depression is known to be associated with poorer outcomes of CHD. Psychological factors, such as major depression and stress, are now known as risk factors for developing CHD, which is as important and is independent of classic risk factors, such as hypertension, diabetes mellitus, and cigarette smoking. Both conditions have great socioeconomic importance given that depression and CHD are likely to be two of the three leading causes of global burden of disease. Better understanding of the common causal pathways will help us delineate more appropriate treatments. PMID:27047396

    • Quantum and classical optics-emerging links

      NASA Astrophysics Data System (ADS)

      Eberly, J. H.; Qian, Xiao-Feng; Qasimi, Asma Al; Ali, Hazrat; Alonso, M. A.; Gutiérrez-Cuevas, R.; Little, Bethany J.; Howell, John C.; Malhotra, Tanya; Vamivakas, A. N.

      2016-06-01

      Quantum optics and classical optics are linked in ways that are becoming apparent as a result of numerous recent detailed examinations of the relationships that elementary notions of optics have with each other. These elementary notions include interference, polarization, coherence, complementarity and entanglement. All of them are present in both quantum and classical optics. They have historic origins, and at least partly for this reason not all of them have quantitative definitions that are universally accepted. This makes further investigation into their engagement in optics very desirable. We pay particular attention to effects that arise from the mere co-existence of separately identifiable and readily available vector spaces. Exploitation of these vector-space relationships are shown to have unfamiliar theoretical implications and new options for observation. It is our goal to bring emerging quantum-classical links into wider view and to indicate directions in which forthcoming and future work will promote discussion and lead to unified understanding.

    • Analysis of lead toxicity in human cells

      PubMed Central

      2012-01-01

      Background Lead is a metal with many recognized adverse health side effects, and yet the molecular processes underlying lead toxicity are still poorly understood. Quantifying the injurious effects of lead is also difficult because of the diagnostic limitations that exist when analyzing human blood and urine specimens for lead toxicity. Results We analyzed the deleterious impact of lead on human cells by measuring its effects on cytokine production and gene expression in peripheral blood mononuclear cells. Lead activates the secretion of the chemokine IL-8 and impacts mitogen-dependent activation by increasing the secretion of the proinflammatory cytokines IL-6 and TNF-α and of the chemokines IL-8 and MIP1-α in the presence of phytohemagglutinin. The recorded changes in gene expression affected major cellular functions, including metallothionein expression, and the expression of cellular metabolic enzymes and protein kinase activity. The expression of 31 genes remained elevated after the removal of lead from the testing medium thereby allowing for the measurement of adverse health effects of lead poisoning. These included thirteen metallothionein transcripts, three endothelial receptor B transcripts and a number of transcripts which encode cellular metabolic enzymes. Cellular responses to lead correlated with blood lead levels and were significantly altered in individuals with higher lead content resultantly affecting the nervous system, the negative regulation of transcription and the induction of apoptosis. In addition, we identified changes in gene expression in individuals with elevated zinc protoporphyrin blood levels and found that genes regulating the transmission of nerve impulses were affected in these individuals. The affected pathways were G-protein mediated signaling, gap junction signaling, synaptic long-term potentiation, neuropathic pain signaling as well as CREB signaling in neurons. Cellular responses to lead were altered in subjects with high

    • Adaptive laser link reconfiguration using constraint propagation

      NASA Technical Reports Server (NTRS)

      Crone, M. S.; Julich, P. M.; Cook, L. M.

      1993-01-01

      networks. Conclusions are presented, including a graphical analysis of results depicting the ordered set of links versus the set of all possible links based on the computed Bit Error Rate (BER). Finally, future research is discussed which includes enhancements to the HALO algorithm, network simulation, and the addition of an intelligent routing algorithm for BP.

    • Nurses: advocating, leading, caring!

      PubMed

      Ferguson, Stephanie L

      2013-01-01

      This speech was delivered on 27 October at the 2012 Conference and general meeting of the Italian Nurses Association CNAI (Consociazione nazionale delle Associazioni infermiere/i) held in Rome from 25 to 27 October 2012. The theme of the conference was "No Nurses No Future". The "No Nurses No Future" is a national campaign developed by the nurses of the Italian Nurses Association to fight for the rights of the profession to sustain not only the practice of the nurse, strong nursing education, research and regulation, but more importantly to ensure that in the future there will be enough nurses in the healthcare workforce to advocate, lead and care for the citizens of Italy.Italian nurses took advantage of the presence of prof. Ferguson and, before travelling to Rome, the Region Lombardy IPASVI Colleges (Coordinamento dei Collegi IPASVI della regione Lombardia) invited her to talk on the same topic during a jointed Conference with CNAI at Circolo della Stampa of Milan on 23rd October.

    • Accelerating coordination in temporal networks by engineering the link order

      NASA Astrophysics Data System (ADS)

      Masuda, Naoki

      2016-02-01

      Social dynamics on a network may be accelerated or decelerated depending on which pairs of individuals in the network communicate early and which pairs do later. The order with which the links in a given network are sequentially used, which we call the link order, may be a strong determinant of dynamical behaviour on networks, potentially adding a new dimension to effects of temporal networks relative to static networks. Here we study the effect of the link order on linear coordination (i.e., synchronisation) dynamics. We show that the coordination speed considerably depends on specific orders of links. In addition, applying each single link for a long time to ensure strong pairwise coordination before moving to a next pair of individuals does not often enhance coordination of the entire network. We also implement a simple greedy algorithm to optimise the link order in favour of fast coordination.

    • DETERMINANTS OF RESIDENTIAL LEAD EXPOSURE

      EPA Science Inventory

      The phase-out of leaded gasoline, and the accompanying decrease in lead emissions, resulted in a dramatic decline in mean blood lead levels from the late 1970s through the early 1990s. Nonetheless, lead exposures remain a public health concern. Long-term exposures to even low...

    • 78 FR 12295 - Procurement List; Additions

      Federal Register 2010, 2011, 2012, 2013, 2014

      2013-02-22

      ... . SUPPLEMENTARY INFORMATION: Additions On 11/27/2012 (77 FR 70737-70738); 11/30/2012 (77 FR 71400-71401); 12/14/2012 (77 FR 74469-74470); 12/21/2012 (77 FR 75616); and 12/31/ 2012 (77 FR 77038), the Committee for...--Battery, 3.6V, A, Lithium NSN: 6140-01-032-1326--Battery, Storage, 12V, Lead Acid, Wet Charged NSN:...

    • Collagen Cross-Linking Using Riboflavin and Ultraviolet-A for Corneal Thinning Disorders

      PubMed Central

      Pron, G; Ieraci, L; Kaulback, K

      2011-01-01

      Executive Summary Objective The main objectives for this evidence-based analysis were to determine the safety and effectiveness of photochemical corneal collagen cross-linking with riboflavin (vitamin B2) and ultraviolet-A radiation, referred to as CXL, for the management of corneal thinning disease conditions. The comparative safety and effectiveness of corneal cross-linking with other minimally invasive treatments such as intrastromal corneal rings was also reviewed. The Medical Advisory Secretariat (MAS) evidence-based analysis was performed to support public financing decisions. Subject of the Evidence-Based Analysis The primary treatment objective for corneal cross-linking is to increase the strength of the corneal stroma, thereby stabilizing the underlying disease process. At the present time, it is the only procedure that treats the underlying disease condition. The proposed advantages for corneal cross-linking are that the procedure is minimally invasive, safe and effective, and it can potentially delay or defer the need for a corneal transplant. In addition, corneal cross-linking does not adversely affect subsequent surgical approaches, if they are necessary, or interfere with corneal transplants. The evidence for these claims for corneal cross-linking in the management of corneal thinning disorders such as keratoconus will be the focus of this review. The specific research questions for the evidence review were as follows: Technical: How technically demanding is corneal cross-linking and what are the operative risks? Safety: What is known about the broader safety profile of corneal cross-linking? Effectiveness - Corneal Surface Topographic Affects: What are the corneal surface remodeling effects of corneal cross-linking? Do these changes interfere with subsequent interventions, particularly corneal transplant known as penetrating keratoplasty (PKP)? Effectiveness -Visual Acuity: What impacts does the remodeling have on visual acuity? Are these impacts

    • Childhood lead poisoning associated with lead dust contamination of family vehicles and child safety seats - Maine, 2008.

      PubMed

      2009-08-21

      Persons employed in high-risk lead-related occupations can transport lead dust home from a worksite through clothing, shoes, tools, or vehicles. During 2008, the Maine Childhood Lead Poisoning Prevention Program (MCLPPP) identified 55 new cases of elevated (>or=15 microg/dL) venous blood lead levels (BLLs) among children aged <6 years through mandated routine screening. Although 90% of childhood lead poisoning cases in Maine during 2003-2007 had been linked to lead hazards in the child's home, no lead-based paint or dust or water with elevated lead levels were found inside the homes associated with six of the 2008 cases (i.e., five families, including one family with two affected siblings). An expanded environmental investigation determined that these six children were exposed to lead dust in the family vehicles and in child safety seats. The sources of the lead dust were likely household contacts who worked in high-risk lead exposure occupations. Current recommendations for identifying and reducing risk from take-home lead poisoning include 1) ensuring that children with elevated BLLs are identified through targeted blood lead testing, 2) directing prevention activities to at-risk workers and employers, and 3) improving employer safety protocols. State and federal prevention programs also should consider, when appropriate, expanded environmental lead dust testing to include vehicles and child safety seats.

    • 29 CFR 1926.62 - Lead.

      Code of Federal Regulations, 2010 CFR

      2010-07-01

      ... attention to the adverse reproductive effects on both males and females and hazards to the fetus and... 29 CFR 1910.1025(a)(2) is covered by this standard. Construction work is defined as work for... collection systems; (B) Spray painting with lead paint. (ii) In addition, with regard to tasks not listed...

  1. 29 CFR 1926.62 - Lead.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 CFR 1910.1025(a)(2) is covered by this standard. Construction work is defined as work for... collection systems; (B) Spray painting with lead paint. (ii) In addition, with regard to tasks not listed in... are present: rivet busting; power tool cleaning without dust collection systems; cleanup...

  2. Leading Your Leaders

    NASA Technical Reports Server (NTRS)

    Hale, Wayne N.

    2008-01-01

    life is good. More often when an unbelievably difficult test fails, we are left with a very long discussion of why and what was wrong in the design or execution of the test. Make sure that the test is well defined. Even then, it is important to explain to your leaders what inherent accuracy (or error) the test conditions or equipment have and what the assumptions or initial conditions were for the test. Test results without a good understanding of the test's accuracy or the pedigree of the test assumptions are worth very little. Finally, there is flight test data. Always limited, never at the edge of the envelope, it still shows how the real hardware works in a combined environment. Flight experience is dangerous because it typically doesn't show how close to the edge of the cliff the equipment is operating, but it does demonstrate how the hardware really works. A flight test is the ultimate test, again taken with the knowledge that it is probably not the extreme but something more like the middle of the environmental and systems performance. Good understanding of a problem and its solution always relies on a combination of all these methods. Be sure to lead your leaders by using all the tools you have at your disposal. At the end of the day, decisions in space flight always come down to a risk trade. Our business is not remotely safe, not in the sense that the public, the media, or our legislators use the term. Everything we do has a risk, cost, schedule, or performance trade-off. For your leaders to make an appropriate decision, you need to educate them, lead them, talk with them, and engage them in the discussion until full understanding takes place. It's your job. *

  3. Protective link for superconducting coil

    DOEpatents

    Umans, Stephen D.

    2009-12-08

    A superconducting coil system includes a superconducting coil and a protective link of superconducting material coupled to the superconducting coil. A rotating machine includes first and second coils and a protective link of superconducting material. The second coil is operable to rotate with respect to the first coil. One of the first and second coils is a superconducting coil. The protective link is coupled to the superconducting coil.

  4. Using ATM over SATCOM links

    NASA Technical Reports Server (NTRS)

    Comparetto, Gary M.

    1995-01-01

    The Asynchronous Transfer Mode (ATM) protocol is studied from the standpoint of determining what limitations, if any, exist in using it over satellite links. It is concluded that, while there is nothing intrinsic about ATM that would generally preclude its use over satellite links, there are, however, several intrinsic characteristics of satellite links, as well as some satellite system configuration-specific issues, that must be taken into account.

  5. Design and Analysis of Underwater Acoustic Networks with Reflected Links

    NASA Astrophysics Data System (ADS)

    Emokpae, Lloyd

    Underwater acoustic networks (UWANs) have applications in environmental state monitoring, oceanic profile measurements, leak detection in oil fields, distributed surveillance, and navigation. For these applications, sets of nodes are employed to collaboratively monitor an area of interest and track certain events or phenomena. In addition, it is common to find autonomous underwater vehicles (AUVs) acting as mobile sensor nodes that perform search-and-rescue missions, reconnaissance in combat zones, and coastal patrol. These AUVs are to work cooperatively to achieve a desired goal and thus need to be able to, in an ad-hoc manner, establish and sustain communication links in order to ensure some desired level of quality of service. Therefore, each node is required to adapt to environmental changes and be able to overcome broken communication links caused by external noise affecting the communication channel due to node mobility. In addition, since radio waves are quickly absorbed in the water medium, it is common for most underwater applications to rely on acoustic (or sound) rather than radio channels for mid-to-long range communications. However, acoustic channels pose multiple challenging issues, most notably the high transmission delay due to slow signal propagation and the limited channel bandwidth due to high frequency attenuation. Moreover, the inhomogeneous property of the water medium affects the sound speed profile while the signal surface and bottom reflections leads to multipath effects. In this dissertation, we address these networking challenges by developing protocols that take into consideration the underwater physical layer dynamics. We begin by introducing a novel surface-based reflection scheme (SBR), which takes advantage of the multipath effects of the acoustic channel. SBR works by using reflections from the water surface, and bottom, to establish non-line-of-sight (NLOS) communication links. SBR makes it possible to incorporate both line

  6. "Conjectural" links in complex networks

    NASA Astrophysics Data System (ADS)

    Snarskii, A. A.; Zorinets, D. I.; Lande, D. V.

    2016-11-01

    This paper introduces the concept of Conjectural Link for Complex Networks, in particular, social networks. Conjectural Link we understand as an implicit link, not available in the network, but supposed to be present, based on the characteristics of its topology. It is possible, for example, when in the formal description of the network some connections are skipped due to errors, deliberately hidden or withdrawn (e.g. in the case of partial destruction of the network). Introduced a parameter that allows ranking the Conjectural Link. The more this parameter - the more likely that this connection should be present in the network. This paper presents a method of recovery of partially destroyed Complex Networks using Conjectural Links finding. Presented two methods of finding the node pairs that are not linked directly to one another, but have a great possibility of Conjectural Link communication among themselves: a method based on the determination of the resistance between two nodes, and method based on the computation of the lengths of routes between two nodes. Several examples of real networks are reviewed and performed a comparison to know network links prediction methods, not intended to find the missing links in already formed networks.

  7. Bone lead levels are associated with measures of memory impairment in older adults

    PubMed Central

    van Wijngaarden, Edwin; Campbell, James R.; Cory-Slechta, Deborah A.

    2009-01-01

    Accumulating evidence suggests a link between lead exposure and memory impairment but assessments based on predictive and validated measures are lacking. We conducted a pilot study of 47 healthy subjects 55-67 years of age to examine associations between bone lead levels and 4 tests sensitive to the natural history of Mild Cognitive Impairment (MCI) and Alzheimer's disease (AD). These include 3 subtests of the Cambridge Neuropsychological Test Automated Battery (delayed match-to-sample, paired associates learning and spatial recognition memory) and the Montreal Cognitive Assessment Test. Bone lead concentrations were measured at the mid-shaft of the tibia and the calcaneus with K X-ray fluorescence. Higher tibial and calcaneal bone lead values were significantly (p<0.05) associated with lower performance levels on delayed match-to-sample and paired associates learning in unadjusted analyses with Spearman rank correlation coefficients of about 0.4. Multiple linear regression analyses (i.e., least-squares means of cognitive test scores across tertiles of lead exposure) adjusted for age, education and smoking status continued to show an association of higher calcaneal lead levels with increasing memory impairments on delayed match-to-sample (p=0.07). As might be expected, additional adjustment for history of hypertension reduced the strength of this association (p=0.19). Given the demonstrated impact of lead exposure on hypertension and the vascular etiology of certain dementias, we speculate that hypertension could play a mediating role in the association between lead exposure and memory impairment. PMID:19477197

  8. Current issues in human lead exposure and regulation of lead.

    PubMed

    Davis, J M; Elias, R W; Grant, L D

    1993-01-01

    Concern about lead as a significant public health problem has increased as epidemiological and experimental evidence has mounted regarding adverse health effects at successively lower levels of lead exposure. This concern has led to downward revision of criteria for acceptable blood lead concentrations to the 10 micrograms/dL mark now designated by EPA as a target level for regulatory development and enforcement/clean-up purposes. Much progress has been made in reducing lead exposures during the past 10-15 years, with marked declines evident both in air lead and blood lead concentrations in parallel to the phase-down of lead in gasoline and notable decreases in food lead exposure due to elimination of lead soldered cans by U.S. food processors. With the lessening of exposure from these sources, the importance of other components of multimedia exposure pathways has grown and stimulated increasing regulatory attention and abatement efforts to reduce health risks associated with lead exposure from drinking water, from lead-based paint, and from household dust and soil contaminated by deteriorating paint, smelter emissions, or various other sources. Increasing attention is also being accorded to reduction of occupational lead exposures (including those related to lead abatement activities), with particular concern for protection of men and women during their reproductive years.

  9. Linking pharmacovigilance with pharmacogenetics.

    PubMed

    Clark, David W J; Donnelly, Emma; Coulter, David M; Roberts, Rebecca L; Kennedy, Martin A

    2004-01-01

    The ability to identify individuals who are susceptible to adverse drug reactions (ADRs) has the potential to reduce the personal and population costs of drug-related morbidity. Some individuals may show an increased susceptibility to certain ADRs through genetic polymorphisms that alter their responses to various drugs. We wished to establish a methodology that would be acceptable to members of the general population and that would enable estimation of the risks that specific genetic factors confer on susceptibility to specific ADRs. Buccal swabs were selected as a minimally invasive method to obtain cells for DNA extraction. We wished to determine whether DNA of sufficient quantity and quality could be obtained to enable genotyping for two different polymorphic genes that code for enzymes that are widely involved in drug disposition. This article describes a small pilot study of methodology developed in the New Zealand Intensive Medicines Monitoring Programme (IMMP) to link prescription event monitoring (PEM) studies with pharmacogenetics. The methodology involves a nested case-control study design to investigate whether patients with genetic variants in P-glycoprotein (P-gp) and cytochrome P450 (CYP) 2C9 are more susceptible to psychiatric or visual disturbances following cyclo- oxygenase-2 inhibitor use (ADR signals identified in the IMMP database) than matched control patients taking the medication without experiencing any ADRs. It was concluded that the use of buccal swabs is acceptable to patients and provides DNA of sufficient quantity and quality for genotyping. Although no differences in the distribution of genotypes in the case and control populations were found in this small study, case-control studies investigating genetic risks for ADRs using drug cohorts from PEM studies are possible, and there are several areas where population-based studies of genetic risk factors for ADRs are needed. Examples are discussed where research in large populations is

  10. Improving personalized link prediction by hybrid diffusion

    NASA Astrophysics Data System (ADS)

    Liu, Jin-Hu; Zhu, Yu-Xiao; Zhou, Tao

    2016-04-01

    Inspired by traditional link prediction and to solve the problem of recommending friends in social networks, we introduce the personalized link prediction in this paper, in which each individual will get equal number of diversiform predictions. While the performances of many classical algorithms are not satisfactory under this framework, thus new algorithms are in urgent need. Motivated by previous researches in other fields, we generalize heat conduction process to the framework of personalized link prediction and find that this method outperforms many classical similarity-based algorithms, especially in the performance of diversity. In addition, we demonstrate that adding one ground node that is supposed to connect all the nodes in the system will greatly benefit the performance of heat conduction. Finally, better hybrid algorithms composed of local random walk and heat conduction have been proposed. Numerical results show that the hybrid algorithms can outperform other algorithms simultaneously in all four adopted metrics: AUC, precision, recall and hamming distance. In a word, this work may shed some light on the in-depth understanding of the effect of physical processes in personalized link prediction.

  11. Facilitating Collaboration Through Linked Open Data

    NASA Astrophysics Data System (ADS)

    Narock, T. W.; Rozell, E. A.; Robinson, E. M.

    2012-12-01

    The increasing volumes, complexity, and heterogeneity of scientific data are requiring members of formally disparate disciplines to come together to address today's scientific challenges. Data science is formed at the intersection of domain scientists, information specialists, librarians, computer scientists and data managers. With such a distributed and diverse community, it can be difficult to identify collaborators, keep track of current research, and assess the underlying social network. We introduce the notion of data science within the Earth and space sciences and present a novel tool for understanding the evolving research network. Linked Data, a modern paradigm for data publishing, leverages the inherent linking capabilities of the Web. Additionally, Linked Data is a machine understandable data format that enables computational reasoning and inferencing. Using this concept, we have linked data from a number of disparate sources such as, hundreds of thousands of AGU abstracts, National Science Foundation project information, people, and organizations. We highlight new collaborations and insights enabled by visualizing the relationships between publications, science data, people, organizations, and events and discuss how such an approach can benefit with extensions from the community at large.

  12. The Oceanic Lead Trends Recorded by Sclerosponges.

    NASA Astrophysics Data System (ADS)

    Verheyden, S.; André, L.; Willenz, P.; Navez, J.; Calmars Group, T.

    2002-12-01

    Lead profiles measured by ICP-MS in two Bahamian and three Jamaican sclerosponges display an increase in lead concentration during the last century, followed by a decrease since the seventies. This trend previously shown in polar ice and corals was explained by changes in atmospheric lead due to the use of leaded gasoline and the increasing use of unleaded gasoline since the seventies. Replicate profiles demonstrate the high reproducibility in single specimens. Different specimens from the same location display similar results, which demonstrates the reproducibility of the lead concentrations in different specimens. The similarity between the ICP-MS and LA-ICP-MS (Lazareth et al., 2000) measurements in two specimens from Acklins Island (Bahamas), confirms the reliability of laser ablation ICP-MS measurements. Regional differences, e.g. from 1930 to 1970 year AD a 2.5-fold increase in Jamaica (from 0.4 to 1.0 ppm), a 2.5-fold increase at Acklins Island (from 0.8 to 2.0 ppm) and a 4-fold increase at Turks and Caicos Islands (from 1.0 to 4.2 ppm) either reflect differences in intensity of the atmospheric and/ or seawater pollution or is linked with a regional seawater distribution of lead due to the local organisation of the oceanic currents.\\An average growth rate of 233 micrometer per year was assumed, according to the work of Willenz and Hartman (1999). Since variations in the growth rate of the different studied sclerosponges is obvious, dating possibilities are explored in order to perfectly match the lead maxima. Between the maximum lead concentration and 1990, the lead curves display a ~1.3-fold decrease for the three Jamaican specimens and a ~2.3-fold decrease for the Turks and Caicos specimen. The specimens from Acklins Island, sampled in 1984 and 1981 recorded the onset of the decrease. Anomalous high values are obtained for the upper samples, where organic matter is present. These values are probably due to element enrichment in the dried tissues

  13. The lead industry and lead water pipes "A Modest Campaign".

    PubMed

    Rabin, Richard

    2008-09-01

    Lead pipes for carrying drinking water were well recognized as a cause of lead poisoning by the late 1800s in the United States. By the 1920s, many cities and towns were prohibiting or restricting their use. To combat this trend, the lead industry carried out a prolonged and effective campaign to promote the use of lead pipes. Led by the Lead Industries Association (LIA), representatives were sent to speak with plumbers' organizations, local water authorities, architects, and federal officials. The LIA also published numerous articles and books that extolled the advantages of lead over other materials and gave practical advice on the installation and repair of lead pipes. The LIA's activities over several decades therefore contributed to the present-day public health and economic cost of lead water pipes.

  14. Leaded electronic waste is a possible source material for lead-contaminated jewelry.

    PubMed

    Weidenhamer, Jeffrey D; Clement, Michael L

    2007-10-01

    Highly leaded jewelry, often imported from China, remains widely available in the United States. Leaded electronic waste is exported from the United States to several Asian countries where solder is recovered and circuit boards are stripped of parts in small workshops. To assess whether electronic waste is being recycled into the jewelry, lead, tin and copper content of highly leaded jewelry samples were determined by atomic absorption spectrometry. Sixteen jewelry items previously determined to contain 20-80% lead by weight were analyzed. Samples were digested in nitric acid for analysis of lead and copper, and in aqua regia for analysis of tin. Six samples contained significant amounts of tin, from 20.8% to 29.9% by weight. In addition, copper was a significant minor component of five of these samples (up to 4% by weight). Copper (present at 10-40% by weight in circuit boards) was shown to rapidly move into heated lead-tin solder. The combined lead-tin-copper content of these six items ranges from 93.5% to 100%, suggestive of a solder-based source material. These results are consistent with the hypothesis that recycled circuit board solders are being used to produce some of the heavily leaded imported jewelry sold in the United States. Should this hypothesis be substantiated, it suggests that environmental policies to protect children's health must address both proper recycling of source materials as well as restrictions of the lead content in consumer goods. PMID:17532022

  15. Renal effects of environmental and occupational lead exposure.

    PubMed Central

    Loghman-Adham, M

    1997-01-01

    Environmental and industrial lead exposures continue to pose major public health problems in children and in adults. Acute exposure to high concentrations of lead can result in proximal tubular damage with characteristic histologic features and manifested by glycosuria and aminoaciduria. Chronic occupational exposure to lead, or consumption of illicit alcohol adulterated with lead, has also been linked to a high incidence of renal dysfunction, which is characterized by glomerular and tubulointerstitial changes resulting in chronic renal failure, hypertension, hyperuricemia, and gout. A high incidence of nephropathy was reported during the early part of this century from Queensland, Australia, in persons with a history of childhood lead poisoning. No such sequela has been found in studies of three cohorts of lead-poisoned children from the United States. Studies in individuals with low-level lead exposure have shown a correlation between blood lead levels and serum creatinine or creatinine clearance. Chronic low-level exposure to lead is also associated with increased urinary excretion of low molecular weight proteins and lysosomal enzymes. The relationship between renal dysfunction detected by these sensitive tests and the future development of chronic renal disease remains uncertain. Epidemiologic studies have shown an association between blood lead levels and blood pressure, and hypertension is a cardinal feature of lead nephropathy. Evidence for increased body lead burden is a prerequisite for the diagnosis of lead nephropathy. Blood lead levels are a poor indicator of body lead burden and reflect recent exposure. The EDTA lead mobilization test has been used extensively in the past to assess body lead burden. It is now replaced by the less invasive in vivo X-ray fluorescence for determination of bone lead content. Images p928-a Figure 1. Figure 2. Figure 2. Figure 3. PMID:9300927

  16. Continental Margins: Linking Ecosystems

    NASA Astrophysics Data System (ADS)

    Kelly-Gerreyn, Boris; Rabalais, Nancy; Middelburg, Jack; Roy, Sylvie; Liu, Kon-Kee; Thomas, Helmuth; Zhang, Jing

    2008-02-01

    Impacts of Global, Local and Human Forcings on Biogeochemical Cycles and Ecosystems, IMBER/LOICZ Continental Margins Open Science Conference; Shanghai, China, 17-21 September 2007; More than 100 scientists from 25 countries came together to address global, regional, local, and human pressures interactively affecting continental margin biogeochemical cycles, marine food webs, and society. Continental margins cover only 12% of the global ocean area yet account for more than 30% of global oceanic primary production. In addition, continental margins are the most intensely used regions of the world's ocean for natural commodities, including productive fisheries and mineral and petroleum resources. The land adjacent to continental margins hosts about 50% of the world's population, which will bear many direct impacts of global change on coastal margins. Understanding both natural and human-influenced alterations of biogeochemical cycles and ecosystems on continental margins and the processes (including feedbacks) that threaten sustainability of these systems is therefore of global interest.

  17. Treating dyslipidemias: is inflammation the missing link?

    PubMed

    Papoutsidakis, Nikolaos; Deftereos, Spyridon; Giannopoulos, Georgios; Panagopoulou, Vasiliki; Manolis, Antonis S; Bouras, Georgios

    2014-01-01

    Low-grade chronic inflammation is now being held as an important process in the development of atherosclerosis, with new links between dyslipidemia and inflammation being constantly found. While most studies aim to discover inflammatory pathways leading from dyslipidemia to atherogenesis, there is evidence that inflammation can also act in reverse, altering lipid metabolism in unfavorable ways, possibly creating a vicious cycle of inflammationdyslipidemia- inflammation. This is highly relevant for the search of novel therapeutic targets. In this review, after a brief account of the inflammatory mechanisms leading from dyslipidemia to atherogenesis, we focus on what is currently known about the ways inflammation can impair lipid metabolism and whether anti-inflammatory therapies could have a role in dyslipidemia management.

  18. Get the lead out: The many faces of lead law

    SciTech Connect

    Vernon, L.S.

    1996-10-01

    There are numerous laws and regulations which apply to lead and its compounds because lead is used in many different ways. There is some confusion regarding which laws apply and how they affect the corrosion field. This paper provides a brief overview of the various lead laws found at the federal level, their applicability, and requirements.

  19. Interpreting Linked Psychomotor Performance Scores

    ERIC Educational Resources Information Center

    Looney, Marilyn A.

    2013-01-01

    Given that equating/linking applications are now appearing in kinesiology literature, this article provides an overview of the different types of linked test scores: equated, concordant, and predicted. It also addresses the different types of evidence required to determine whether the scores from two different field tests (measuring the same…

  20. Interrelations of lead levels in bone, venous blood, and umbilical cord blood with exogenous lead exposure through maternal plasma lead in peripartum women.

    PubMed Central

    Chuang, H Y; Schwartz, J; Gonzales-Cossio, T; Lugo, M C; Palazuelos, E; Aro, A; Hu, H; Hernandez-Avila, M

    2001-01-01

    lead of 0.65 and 0.25 microg/dL, respectively. An increase of 0.1 microg/m(3) in air lead was associated with an increase in the mean level of fetal cord blood lead by 0.67 microg/dL. With one additional day of LCG use per week in the peripartum period, the mean fetal blood lead level increased by 0.27 microg/dL. Our analyses suggested that maternal plasma lead varies independently from maternal whole blood lead and that the greatest influences on maternal plasma lead are maternal bone lead stores, air lead exposures, and recent cooking with LGC. The contributions from endogenous (bone) and exogenous (environmental) sources were relatively equal. Measurement of plasma and bone lead may be important in accurately assessing fetal lead exposure and its major sources, particularly if exogenous exposures decline. PMID:11401766

  1. Interrelations of lead levels in bone, venous blood, and umbilical cord blood with exogenous lead exposure through maternal plasma lead in peripartum women.

    PubMed

    Chuang, H Y; Schwartz, J; Gonzales-Cossio, T; Lugo, M C; Palazuelos, E; Aro, A; Hu, H; Hernandez-Avila, M

    2001-05-01

    lead of 0.65 and 0.25 microg/dL, respectively. An increase of 0.1 microg/m(3) in air lead was associated with an increase in the mean level of fetal cord blood lead by 0.67 microg/dL. With one additional day of LCG use per week in the peripartum period, the mean fetal blood lead level increased by 0.27 microg/dL. Our analyses suggested that maternal plasma lead varies independently from maternal whole blood lead and that the greatest influences on maternal plasma lead are maternal bone lead stores, air lead exposures, and recent cooking with LGC. The contributions from endogenous (bone) and exogenous (environmental) sources were relatively equal. Measurement of plasma and bone lead may be important in accurately assessing fetal lead exposure and its major sources, particularly if exogenous exposures decline.

  2. Incorporation of additives into polymers

    DOEpatents

    McCleskey, T. Mark; Yates, Matthew Z.

    2003-07-29

    There has been invented a method for incorporating additives into polymers comprising: (a) forming an aqueous or alcohol-based colloidal system of the polymer; (b) emulsifying the colloidal system with a compressed fluid; and (c) contacting the colloidal polymer with the additive in the presence of the compressed fluid. The colloidal polymer can be contacted with the additive by having the additive in the compressed fluid used for emulsification or by adding the additive to the colloidal system before or after emulsification with the compressed fluid. The invention process can be carried out either as a batch process or as a continuous on-line process.

  3. [Patch-testing methods: additional specialised or additional series].

    PubMed

    Cleenewerck, M-B

    2009-01-01

    The tests in the European standard battery must occasionally be supplemented by specialised or additional batteries, particularly where the contact allergy is thought to be of occupational origin. These additional batteries cover all allergens associated with various professional activities (hairdressing, baking, dentistry, printing, etc.) and with different classes of materials and chemical products (glue, plastic, rubber...). These additional tests may also include personal items used by patients on a daily basis such as cosmetics, shoes, plants, textiles and so on.

  4. Soil lead-blood lead relationship among Boston children

    SciTech Connect

    Rabinowitz, M.B.; Bellinger, D.C.

    1988-12-01

    Lead contaminated soil has been consistently been found to contribute significantly to children's risk of blood lead elevation. An association between soil lead and blood lead has been reported for children in Holland, Rochester, New York, Omaha, Nebraska, Christchurch, New Zealand, and Kellogg, Idaho. The authors report on the connection between soil and blood lead levels among a group of Boston children in order to document this pattern of association in a specific setting which may be analogous to other situations of interest. The base population consisted of 11,837 consecutive births at the Boston Hospital for Women between April 1979 and April 1981.

  5. Additive manufacturing of optical components

    NASA Astrophysics Data System (ADS)

    Heinrich, Andreas; Rank, Manuel; Maillard, Philippe; Suckow, Anne; Bauckhage, Yannick; Rößler, Patrick; Lang, Johannes; Shariff, Fatin; Pekrul, Sven

    2016-08-01

    The development of additive manufacturing methods has enlarged rapidly in recent years. Thereby, the work mainly focuses on the realization of mechanical components, but the additive manufacturing technology offers a high potential in the field of optics as well. Owing to new design possibilities, completely new solutions are possible. This article briefly reviews and compares the most important additive manufacturing methods for polymer optics. Additionally, it points out the characteristics of additive manufactured polymer optics. Thereby, surface quality is of crucial importance. In order to improve it, appropriate post-processing steps are necessary (e.g. robot polishing or coating), which will be discussed. An essential part of this paper deals with various additive manufactured optical components and their use, especially in optical systems for shape metrology (e.g. borehole sensor, tilt sensor, freeform surface sensor, fisheye lens). The examples should demonstrate the potentials and limitations of optical components produced by additive manufacturing.

  6. Lead testing wipes contain measurable background levels of lead.

    PubMed

    Keenan, James J; Le, Matthew H; Paustenbach, Dennis J; Gaffney, Shannon H

    2010-03-01

    Lead is registered under the California Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65) as both a carcinogen and a reproductive hazard. As part of the process to determine if consumer products satisfy Proposition 65 with respect to lead, various wipe sampling strategies have been utilized. Four commonly used wipe materials (cotton gauze, cotton balls, ashless filter paper, and Ghost Wipes) were tested for background lead levels. Ghost Wipe material was found to have 0.43 +/- 0.11 microg lead/sample (0.14 microg/wipe). Wipe testing for lead using Ghost Wipes may therefore result in measurable concentrations of lead, regardless of whether or not the consumer product actually contains leachable lead. PMID:20087726

  7. Lead poisoning of seabirds: environmental risks from leaded paint at a decommissioned military base.

    PubMed

    Finkelstein, Myra E; Gwiazda, Roberto H; Smith, Donald R

    2003-08-01

    The sources and risk factors for lead exposure to humans are relatively well recognized, yet much less is known about lead exposure risks and effects to wildlife. Here we utilized lead isotopic fingerprinting to investigate sources of elevated lead exposure to Laysan albatross (Phoebastria immutabilis) chicks in the Midway Island National Wildlife Refuge, which was established on the site of a decommissioned military base that previously had undergone lead remediation. Whole blood from chicks as well as soil and paint chips from the chicks' nests were collected from birds nesting close to (<5 m, building site) and distant from (>100 m, reference site) buildings and analyzed for lead levels and isotopic compositions using magnetic sector ICP-MS. Blood lead levels of chicks from the building site had a geometric mean of 190 microg/dL (average = 320 +/- 310 SD, range = 6.8-1400, n = 21) as compared to 4.5 microg/dL (average = 6.0 +/- 4.2 SD, range = 1.2-13, n = 15) in chicks from the reference site. Nest soil lead levels from both sites were similar and relatively low (0.05-11 microg/g) unless visibly contaminated with paint chips (building site). Isotopic analyses confirmed that leaded paint was the source of lead poisoning in these chicks and showed that the pathway of exposure was via direct ingestion of paint chips and not through contaminated soil. This study found continued risk to wildlife and possibly humans from lead hazards in a wildlife refuge established on a decommissioned military base. In addition, this study demonstrates the utility of lead isotopes to identify environmental lead hazards and exposure pathways to wildlife.

  8. Associations of lead biomarkers with renal function in Korean lead workers

    PubMed Central

    Weaver, V; Lee, B; Ahn, K; Lee, G; Todd, A; Stewart, W; Wen, J; Simon, D; Parsons, P; Schwartz, B

    2003-01-01

    Aims: To compare associations of lead biomarkers with renal function in current and former lead workers. Methods: Cross sectional analysis of first year results from a longitudinal study of 803 lead workers and 135 controls in South Korea. Clinical renal function was assessed by blood urea nitrogen (BUN), serum creatinine, and measured and calculated creatinine clearance. Urinary N-acetyl-ß-D-glucosaminidase (NAG) and retinol-binding protein were also measured. Results: Mean (SD) tibia lead, blood lead, and DMSA chelatable lead levels in lead workers were 37.2 (40.4) µg/g bone mineral, 32.0 (15.0) µg/dl, and 767.8 (862.1) µg/g creatinine, respectively. Higher lead measures were associated with worse renal function in 16/42 models. When influential outliers were removed, higher lead measures remained associated with worse renal function in nine models. An additional five associations were in the opposite direction. Effect modification by age was observed. In 3/16 models, associations between higher lead measures and worse clinical renal function in participants in the oldest age tertile were significantly different from associations in those in the youngest age tertile which were in the opposite direction. Mean urinary cadmium (CdU) was 1.1 µg/g creatinine (n = 191). Higher CdU levels were associated with higher NAG. Conclusions: These data suggest that lead has an adverse effect on renal function in the moderate dose range, particularly in older workers. Associations between higher lead measures and lower BUN and serum creatinine and higher creatinine clearances may represent lead induced hyperfiltration. Environmental cadmium may also have an adverse renal impact, at least on NAG. PMID:12883015

  9. Lead poisoning of seabirds: environmental risks from leaded paint at a decommissioned military base.

    PubMed

    Finkelstein, Myra E; Gwiazda, Roberto H; Smith, Donald R

    2003-08-01

    The sources and risk factors for lead exposure to humans are relatively well recognized, yet much less is known about lead exposure risks and effects to wildlife. Here we utilized lead isotopic fingerprinting to investigate sources of elevated lead exposure to Laysan albatross (Phoebastria immutabilis) chicks in the Midway Island National Wildlife Refuge, which was established on the site of a decommissioned military base that previously had undergone lead remediation. Whole blood from chicks as well as soil and paint chips from the chicks' nests were collected from birds nesting close to (<5 m, building site) and distant from (>100 m, reference site) buildings and analyzed for lead levels and isotopic compositions using magnetic sector ICP-MS. Blood lead levels of chicks from the building site had a geometric mean of 190 microg/dL (average = 320 +/- 310 SD, range = 6.8-1400, n = 21) as compared to 4.5 microg/dL (average = 6.0 +/- 4.2 SD, range = 1.2-13, n = 15) in chicks from the reference site. Nest soil lead levels from both sites were similar and relatively low (0.05-11 microg/g) unless visibly contaminated with paint chips (building site). Isotopic analyses confirmed that leaded paint was the source of lead poisoning in these chicks and showed that the pathway of exposure was via direct ingestion of paint chips and not through contaminated soil. This study found continued risk to wildlife and possibly humans from lead hazards in a wildlife refuge established on a decommissioned military base. In addition, this study demonstrates the utility of lead isotopes to identify environmental lead hazards and exposure pathways to wildlife. PMID:12966967

  10. Lead in teeth from lead-dosed goats: Microdistribution and relationship to the cumulative lead dose

    SciTech Connect

    Bellis, David J.; Hetter, Katherine M.; Jones, Joseph; Amarasiriwardena, Dula; Parsons, Patrick J.

    2008-01-15

    Teeth are commonly used as a biomarker of long-term lead exposure. There appear to be few data, however, on the content or distribution of lead in teeth where data on specific lead intake (dose) are also available. This study describes the analysis of a convenience sample of teeth from animals that were dosed with lead for other purposes, i.e., a proficiency testing program for blood lead. Lead concentration of whole teeth obtained from 23 animals, as determined by atomic absorption spectrometry, varied from 0.6 to 80 {mu}g g{sup -1}. Linear regression of whole tooth lead ({mu}g g{sup -1}) on the cumulative lead dose received by the animal (g) yielded a slope of 1.2, with r{sup 2}=0.647 (p<0.0001). Laser ablation inductively coupled plasma mass spectrometry was employed to determine lead content at micrometer scale spatial resolution in the teeth of seven goats representing the dosing range. Highly localized concentrations of lead, ranging from about 10 to 2000 {mu}g g{sup -1}, were found in circumpulpal dentine. Linear regression of circumpulpal lead ({mu}g g{sup -1}) on cumulative lead dose (g) yielded a slope of 23 with r{sup 2}=0.961 (p=0.0001). The data indicated that whole tooth lead, and especially circumpulpal lead, of dosed goats increased linearly with cumulative lead exposure. These data suggest that circumpulpal dentine is a better biomarker of cumulative lead exposure than is whole tooth lead, at least for lead-dosed goats.

  11. Novel lead-graphene and lead-graphite metallic composite materials for possible applications as positive electrode grid in lead-acid battery

    NASA Astrophysics Data System (ADS)

    Yolshina, L. A.; Yolshina, V. A.; Yolshin, A. N.; Plaksin, S. V.

    2015-03-01

    Novel lead-graphene and lead-graphite metallic composites which melt at temperature of the melting point of lead were investigated as possible positive current collectors for lead acid batteries in sulfuric acid solution. Scanning electron microscopy, Raman spectroscopy, difference scanning calorimetry, cyclic voltammetry and prolonged corrosion tests were employed to characterize the effect of the newly proposed lead-carbon metallic composites on the structure and electrochemical properties of positive grid material. Both lead-graphene and lead-graphite metallic composite materials show the similar electrochemical characteristics to metallic lead in the voltage range where the positive electrodes of lead acid batteries operate. It has been shown that carbon both as graphene and graphite does not participate in the electrochemical process but improve corrosion and electrochemical characteristics of both metallic composite materials. No products of interaction of lead with sulfuric acid were formed on the surface of graphene and graphite so as it was not found additional peaks of carbon discharge on voltammograms which could be attributed to the carbon. Graphene inclusions in lead prevent formation of leady oxide nanocrystals which deteriorate discharge characteristics of positive electrode of LAB. Both lead-graphene alloy and lead-graphite metallic composite proved excellent electrochemical and corrosion behavior and can be used as positive grids in lead acid batteries of new generation.

  12. Lead in School Drinking Water.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC. Office of Water Programs.

    Lead levels in school drinking water merit special concern because children are more at risk than adults from exposure to lead. This manual provides ways in which school officials can minimize this risk. It assists administrators by providing: (1) general information on the significance of lead in school drinking water and its effects on children;…

  13. Breakthrough: Lead-free Solder

    ScienceCinema

    Anderson, Iver

    2016-07-12

    Ames Laboratory senior metallurgist Iver Anderson explains the importance of lead-free solder in taking hazardous lead out of the environment by eliminating it from discarded computers and electronics that wind up in landfills. Anderson led a team that developed a tin-silver-copper replacement for traditional lead-tin solder that has been adopted by more than 50 companies worldwide.

  14. Breakthrough: Lead-free Solder

    SciTech Connect

    Anderson, Iver

    2012-01-01

    Ames Laboratory senior metallurgist Iver Anderson explains the importance of lead-free solder in taking hazardous lead out of the environment by eliminating it from discarded computers and electronics that wind up in landfills. Anderson led a team that developed a tin-silver-copper replacement for traditional lead-tin solder that has been adopted by more than 50 companies worldwide.

  15. The Changing Way of Leading

    ERIC Educational Resources Information Center

    Sytsma, Sandra

    2009-01-01

    This conceptual article explores the changing way of leading. It proposes that in contrast to the primarily outer actions that characterize educational change, the inner and outer dimensions of leaders are necessary to change what constitutes leading, thereby making it more appropriate to our times. The unfolding of leading actions and the…

  16. Environmental Lead and Children's Health.

    ERIC Educational Resources Information Center

    Lewis, Marie

    This paper discusses the threat to children's health posed by environmental exposure to lead, focusing on public policy issues surrounding lead exposure in New South Wales (NSW), Australia. In Australia, the current blood lead level at which there is a health concern is at or above 25 micrograms per deciliter (ug/dl) of blood for infants and…

  17. Links between Circadian Rhythms and Psychiatric Disease.

    PubMed

    Karatsoreos, Ilia N

    2014-01-01

    Determining the cause of psychiatric disorders is a goal of modern neuroscience, and will hopefully lead to the discovery of treatments to either prevent or alleviate the suffering caused by these diseases. One roadblock to attaining this goal is the realization that neuropsychiatric diseases are rarely due to a single gene polymorphism, environmental exposure, or developmental insult. Rather, it is a complex interaction between these various influences that likely leads to the development of clinically relevant syndromes. Our lab is exploring the links between environmental exposures and neurobehavioral function by investigating how disruption of the circadian (daily) clock alters the structure and function of neural circuits, with the hypothesis that disrupting this crucial homeostatic system can directly contribute to altered vulnerability of the organism to other factors that interact to produce psychiatric illness. This review explores some historical and more recent findings that link disrupted circadian clocks to neuropsychiatric disorders, particularly depression, mania, and schizophrenia. We take a comparative approach by exploring the effects observed in human populations, as well as some experimental models used in the laboratory to unravel mechanistic and causal relationships between disruption of the circadian clock and behavioral abnormalities. This is a rich area of research that we predict will contribute greatly to our understanding of how genes, environment, and development interact to modulate an individual's vulnerability to psychiatric disorders. PMID:24834040

  18. Links between Circadian Rhythms and Psychiatric Disease

    PubMed Central

    Karatsoreos, Ilia N.

    2014-01-01

    Determining the cause of psychiatric disorders is a goal of modern neuroscience, and will hopefully lead to the discovery of treatments to either prevent or alleviate the suffering caused by these diseases. One roadblock to attaining this goal is the realization that neuropsychiatric diseases are rarely due to a single gene polymorphism, environmental exposure, or developmental insult. Rather, it is a complex interaction between these various influences that likely leads to the development of clinically relevant syndromes. Our lab is exploring the links between environmental exposures and neurobehavioral function by investigating how disruption of the circadian (daily) clock alters the structure and function of neural circuits, with the hypothesis that disrupting this crucial homeostatic system can directly contribute to altered vulnerability of the organism to other factors that interact to produce psychiatric illness. This review explores some historical and more recent findings that link disrupted circadian clocks to neuropsychiatric disorders, particularly depression, mania, and schizophrenia. We take a comparative approach by exploring the effects observed in human populations, as well as some experimental models used in the laboratory to unravel mechanistic and causal relationships between disruption of the circadian clock and behavioral abnormalities. This is a rich area of research that we predict will contribute greatly to our understanding of how genes, environment, and development interact to modulate an individual’s vulnerability to psychiatric disorders. PMID:24834040

  19. Human metastable epiallele candidates link to common disorders.

    PubMed

    Harris, R Alan; Nagy-Szakal, Dorottya; Kellermayer, Richard

    2013-02-01

    Metastable epialleles (MEs) are mammalian genomic loci where epigenetic patterning occurs before gastrulation in a stochastic fashion leading to systematic interindividual variation within one species. Importantly, periconceptual nutritional influences may modulate the establishment of epigenetic changes, such as DNA methylation at MEs. Based on these characteristics, we exploited Infinium HumanMethylation450 BeadChip kits in a 2-tissue parallel screen on peripheral blood leukocyte and colonic mucosal DNA from 10 children without identifiable large intestinal disease. This approach led to the delineation of 1776 CpG sites meeting our criteria for MEs, which associated with 1013 genes. The list of ME candidates exhibited overlaps with recently identified human genes (including CYP2E1 and MGMT, where methylation has been associated with Parkinson disease and glioblastoma, respectively) in which perinatal DNA methylation levels where linked to maternal periconceptual nutrition. One hundred 18 (11.6%) of the ME candidates overlapped with genes where DNA methylation correlated (r > 0.871; p < 0.055) with expression in the colon mucosa of 5 independent control children. Genes involved in homophilic cell adhesion (including cadherin-associated genes) and developmental processes were significantly overrepresented in association with MEs. Additional filtering of gene expression-correlated MEs defined 35 genes, associated with 2 or more CpG sites within a 10 kb genomic region, fulfilling the ME criteria. DNA methylation changes at a number of these genes have been linked to various forms of human disease, including cancers, such as asthma and acute myeloid leukemia (ALOX12), gastric cancer (EBF3), breast cancer (NAV1), colon cancer and acute lymphoid leukemia (KCNK15), Wilms tumor (protocadherin gene cluster; PCDHAs) and colorectal cancer (TCERG1L), suggesting a potential etiologic role for MEs in tumorigenesis and underscoring the possible developmental origins of these

  20. Modulation of Innate Immune Responses via Covalently Linked TLR Agonists

    PubMed Central

    2015-01-01

    We present the synthesis of novel adjuvants for vaccine development using multivalent scaffolds and bioconjugation chemistry to spatially manipulate Toll-like receptor (TLR) agonists. TLRs are primary receptors for activation of the innate immune system during vaccination. Vaccines that contain a combination of small and macromolecule TLR agonists elicit more directed immune responses and prolong responses against foreign pathogens. In addition, immune activation is enhanced upon stimulation of two distinct TLRs. Here, we synthesized combinations of TLR agonists as spatially defined tri- and di-agonists to understand how specific TLR agonist combinations contribute to the overall immune response. We covalently conjugated three TLR agonists (TLR4, 7, and 9) to a small molecule core to probe the spatial arrangement of the agonists. Treating immune cells with the linked agonists increased activation of the transcription factor NF-κB and enhanced and directed immune related cytokine production and gene expression beyond cells treated with an unconjugated mixture of the same three agonists. The use of TLR signaling inhibitors and knockout studies confirmed that the tri-agonist molecule activated multiple signaling pathways leading to the observed higher activity. To validate that the TLR4, 7, and 9 agonist combination would activate the immune response to a greater extent, we performed in vivo studies using a vaccinia vaccination model. Mice vaccinated with the linked TLR agonists showed an increase in antibody depth and breadth compared to mice vaccinated with the unconjugated mixture. These studies demonstrate how activation of multiple TLRs through chemically and spatially defined organization assists in guiding immune responses, providing the potential to use chemical tools to design and develop more effective vaccines. PMID:26640818

  1. 58. ROASTER ADDITION INTERIOR FROM EAST, VIEW OF DISCHARGE CREW ...

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

    58. ROASTER ADDITION INTERIOR FROM EAST, VIEW OF DISCHARGE CREW DRIVE WITH GAS PIPING FOR HEARTH FIRING. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  2. Node, Node-Link, and Node-Link-Group Diagrams: An Evaluation.

    PubMed

    Saket, Bahador; Simonetto, Paolo; Kobourov, Stephen; Börner, Katy

    2014-12-01

    Effectively showing the relationships between objects in a dataset is one of the main tasks in information visualization. Typically there is a well-defined notion of distance between pairs of objects, and traditional approaches such as principal component analysis or multi-dimensional scaling are used to place the objects as points in 2D space, so that similar objects are close to each other. In another typical setting, the dataset is visualized as a network graph, where related nodes are connected by links. More recently, datasets are also visualized as maps, where in addition to nodes and links, there is an explicit representation of groups and clusters. We consider these three Techniques, characterized by a progressive increase of the amount of encoded information: node diagrams, node-link diagrams and node-link-group diagrams. We assess these three types of diagrams with a controlled experiment that covers nine different tasks falling broadly in three categories: node-based tasks, network-based tasks and group-based tasks. Our findings indicate that adding links, or links and group representations, does not negatively impact performance (time and accuracy) of node-based tasks. Similarly, adding group representations does not negatively impact the performance of network-based tasks. Node-link-group diagrams outperform the others on group-based tasks. These conclusions contradict results in other studies, in similar but subtly different settings. Taken together, however, such results can have significant implications for the design of standard and domain snecific visualizations tools. PMID:26356937

  3. AAH Cage Out-Link and In-Link Antenna Characterization

    NASA Technical Reports Server (NTRS)

    Jeutter, Dean C.

    1998-01-01

    This final report encapsulates the accomplishments of the third year of work on an Advanced Biotelemetry System (ABTS). Overall MU/ABTS project objectives are to provide a biotelemetry system that can collect data from and send commands to an implanted biotransceiver. This system will provide for studies of rodent development in space. The system must be capable of operating in a metal animal cage environment. An important goal is the development of a small, "smart", micropower, implantable biotransceiver with eight-channel data output and single channel command input capabilities with the flexibility for easy customization for a variety of physiologic investigations. The NASA Ames/Marquette University Joint Research work has been devoted to the system design of such a new state of the art biotelemetry system, having multiple physiologic inputs, and bi-directional data transfer capabilities. This work has provided a successful prototype system that connects, by two-way radio links, an addressable biotelemetry system that provides communication between an animal biotelemeter prototype and a personal computer. The operational features of the prototype system are: (1) two-way PCM communication with implanted biotelemeter; (2) microcontroller based biotelemeter; (3) out-link: wideband FSK (60 kBaud); (4) in-link: OOK (2.4 kbaud); (5) septum antenna arrays (In/Out-Links); and (6) personal computer data interface. The important requirement of this third year's work, to demonstrate two-way communication with transmit and receive antennas inside the metal animal cage, has been successfully accomplished. The advances discussed in this report demonstrate that the AAH cage antenna system can provide Out-link and In-link capability for the ABTS bi-directional telemetry system, and can serve as a benchmark for project status. Additions and enhancements to the most recent (April 1997) prototype cage and antenna have been implemented. The implementation, testing, and

  4. Prevalence of childhood lead poisoning in a lead mining area

    SciTech Connect

    Murgueytio, A.M.; Evans, R.G.; Roberts, D.; Moehr, T.

    1996-06-01

    This study investigated the prevalence of lead poisoning among children six to seventy-one months of age who live in a lead mining area, compared to children not living in an area exposed to lead mining waste. Children were selected from a sampling frame based on a census of the study and control areas. Participants were interviewed and blood and urine were collected for lead and cadmium analysis. Environmental measurements of soil, dust, and paint were also made. Mean blood lead levels were significantly higher in the study group compared to the control group, 6.25 {mu}g/dl and 3.59 {micro}g/dl, respectively. Also, 14% of the study group compared to 0% of the control group had blood lead levels greater than 10 {micro}g/dl, the level of concern established by the Centers for Disease Control and Prevention (CDC). Soil, dust, and paint lead levels were significantly higher in the study area. There were no significant differences between groups in urine cadmium levels although environmental dust and soil cadmium levels were significantly higher in the study group. This study suggested that the increased prevalence of elevated blood lead levels in the study group is highly correlated to a combination of exposure to soil contaminated with lead mining and smelting waste and exposure to household lead paint.

  5. Lead exposure among lead-acid battery workers in Jamaica.

    PubMed

    Matte, T D; Figueroa, J P; Burr, G; Flesch, J P; Keenlyside, R A; Baker, E L

    1989-01-01

    To assess lead exposure in the Jamaican lead-acid battery industry, we surveyed three battery manufacturers (including 46 production workers) and 10 battery repair shops (including 23 battery repair workers). Engineering controls and respiratory protection were judged to be inadequate at battery manufacturers and battery repair shops. At manufacturers, 38 of 42 air samples for lead exceeded a work-shift time-weighted average concentration of 0.050 mg/m3 (range 0.030-5.3 mg/m3), and nine samples exceeded 0.50 mg/m3. Only one of seven air samples at repair shops exceeded 0.050 mg/m3 (range 0.003-0.066 mg/m3). Repair shop workers, however, had higher blood lead levels than manufacturing workers (65% vs. 28% with blood lead levels above 60 micrograms/dl, respectively). Manufacturing workers had a higher prevalence of safe hygienic practices and a recent interval of minimal production had occurred at one of the battery manufacturers. Workers with blood lead levels above 60 micrograms/dl tended to have higher prevalences of most symptoms of lead toxicity than did workers with lower blood lead levels, but this finding was not consistent or statistically significant. The relationship between zinc protoporphyrin concentrations and increasing blood lead concentrations was consistent with that described among workers in developed countries. The high risk of lead toxicity among Jamaican battery workers is consistent with studies of battery workers in other developing countries. PMID:2773946

  6. Lead exposure among lead-acid battery workers in Jamaica.

    PubMed

    Matte, T D; Figueroa, J P; Burr, G; Flesch, J P; Keenlyside, R A; Baker, E L

    1989-01-01

    To assess lead exposure in the Jamaican lead-acid battery industry, we surveyed three battery manufacturers (including 46 production workers) and 10 battery repair shops (including 23 battery repair workers). Engineering controls and respiratory protection were judged to be inadequate at battery manufacturers and battery repair shops. At manufacturers, 38 of 42 air samples for lead exceeded a work-shift time-weighted average concentration of 0.050 mg/m3 (range 0.030-5.3 mg/m3), and nine samples exceeded 0.50 mg/m3. Only one of seven air samples at repair shops exceeded 0.050 mg/m3 (range 0.003-0.066 mg/m3). Repair shop workers, however, had higher blood lead levels than manufacturing workers (65% vs. 28% with blood lead levels above 60 micrograms/dl, respectively). Manufacturing workers had a higher prevalence of safe hygienic practices and a recent interval of minimal production had occurred at one of the battery manufacturers. Workers with blood lead levels above 60 micrograms/dl tended to have higher prevalences of most symptoms of lead toxicity than did workers with lower blood lead levels, but this finding was not consistent or statistically significant. The relationship between zinc protoporphyrin concentrations and increasing blood lead concentrations was consistent with that described among workers in developed countries. The high risk of lead toxicity among Jamaican battery workers is consistent with studies of battery workers in other developing countries.

  7. Contribution of lead in dust to children's blood lead.

    PubMed Central

    Duggan, M J

    1983-01-01

    The importance of urban dust as a source of lead for young children is still disputed. Although blood-lead data from various population surveys usually show a peak concentration in early childhood, there is evidence that such a peak is small or absent altogether in children without much access to the general environment. An examination of those studies where groups of people in regions of low and high lead contamination have been compared shows that the child/adult blood-lead ratio is almost always enhanced in the more exposed groups. This implies a route of lead uptake which is important for children but less so for adults, and it is likely that this route is the dust-hand-mouth one. There are sufficient data to suggest a quantitative relationship between raised levels of blood lead and lead in dust. There is a strong case for a lead-in-dust standard but some will probably remain unpersuaded unless or until there are reliable data for blood lead and environmental lead involving matched groups of young people from urban and rural areas. PMID:6873030

  8. Influence of Cross-Linker Concentration on the Functionality of Carbodiimide Cross-Linked Gelatin Membranes for Retinal Sheet Carriers.

    PubMed

    Lai, Jui-Yang; Li, Ya-Ting

    2011-01-01

    Carbodiimide cross-linking can easily regulate the functionality of gelatin carriers used for retinal sheet delivery. This paper investigates the effect of cross-linker concentrations (0-0.4 mmol EDC/mg gelatin membrane (GM)) on the properties of the chemically-modified GMs. ATR-FT-IR and ninhydrin analyses results consistently indicated that the EDC cross-linking reaction approaches saturation at concentrations around 0.02 mmol EDC/mg GM. The thermal stability and resistance to water dissolution and collagenase digestion were significantly enhanced with increasing cross-linker concentration from 0.001 to 0.02 mmol EDC/mg GM. In addition, the chemical cross-linking did not affect the ability to form a tissue-encapsulating structure at 37°C. Irrespective of their cross-linking degree, the GMs had an appropriate degradation rate sufficient to allow tissue integration. It was noted that, although high cross-linker concentrations can be used to improve the delivery efficiency of gelatin samples, the treatment with 0.1-0.4 mmol EDC/mg GM may lead to poor biocompatibility. Results of Live/Dead and pro-inflammatory cytokine expression analyses showed that the exposure of ARPE-19 cultures to the test materials cross-linked with a concentration ≥0.1 mmol EDC/mg GM induces significant cytotoxicity and high levels of interleukin-1β and interleukin-6. However, the presence of EDC cross-linked gelatin membranes in the culture medium had no effect on the glutamate uptake capacity. It is concluded that among the cross-linked gelatin samples studied, 0.02 mmol EDC/mg GM is the best cross-linker concentration for preparation of retinal sheet delivery carriers.

  9. Enantioselective Michael Addition of Water

    PubMed Central

    Chen, Bi-Shuang; Resch, Verena; Otten, Linda G; Hanefeld, Ulf

    2015-01-01

    The enantioselective Michael addition using water as both nucleophile and solvent has to date proved beyond the ability of synthetic chemists. Herein, the direct, enantioselective Michael addition of water in water to prepare important β-hydroxy carbonyl compounds using whole cells of Rhodococcus strains is described. Good yields and excellent enantioselectivities were achieved with this method. Deuterium labeling studies demonstrate that a Michael hydratase catalyzes the water addition exclusively with anti-stereochemistry. PMID:25529526

  10. Enantioselective Michael addition of water.

    PubMed

    Chen, Bi-Shuang; Resch, Verena; Otten, Linda G; Hanefeld, Ulf

    2015-02-01

    The enantioselective Michael addition using water as both nucleophile and solvent has to date proved beyond the ability of synthetic chemists. Herein, the direct, enantioselective Michael addition of water in water to prepare important β-hydroxy carbonyl compounds using whole cells of Rhodococcus strains is described. Good yields and excellent enantioselectivities were achieved with this method. Deuterium labeling studies demonstrate that a Michael hydratase catalyzes the water addition exclusively with anti-stereochemistry.

  11. EPA lead program (Pb) update

    SciTech Connect

    Lanier, D.

    1994-12-31

    Lead is a cumulative poison that is especially hazardous to children. It affects the nervous and reproductive systems by causing neurological and physical development delays, as well as cognitive and behavioral changes. It can also cause hypertension in adults. Lead can be absorbed into the blood by ingestion or inhalation. The author discusses legislative efforts to control lead exposure to humans. They are: Title 10, which amends TSCA; and Title 4 -- Lead Exposure Reduction. The major tasks being performed by EPA to control the exposure of lead to man are included. Professional training is of major importance in this effort.

  12. Presence of lead in opium.

    PubMed

    Aghaee-Afshar, Mahmoud; Khazaeli, Payam; Behnam, Behzad; Rezazadehkermani, Mohammad; Ashraf-Ganjooei, Narges

    2008-09-01

    Opium addiction is a common form of addiction in Middle East countries such as Iran. Recently several reports suggested some kinds of pathologic findings such as abdominal pain, nephropathy, and anemia in opium addict patients. Such pathologic findings suggest lead poisoning in the patients. In this study, the concentration of lead in 10 opium samples was evaluated. The mean concentration of lead in the opium samples was 1.88 ppm. This may explain some of the pathologic findings found in addict patients. The authors would suggest further investigations to evaluate the lead concentration in opium addicts' sera and also routine screening for lead poisoning in opium addict patients.

  13. Gasoline additives, emissions, and performance

    SciTech Connect

    1995-12-31

    The papers included in this publication deal with the influence of fuel, additive, and hardware changes on a variety of vehicle performance characteristics. Advanced techniques for measuring these performance parameters are also described. Contents include: Fleet test evaluation of gasoline additives for intake valve and combustion chamber deposit clean up; A technique for evaluating octane requirement additives in modern engines on dynamometer test stands; A fleet test of two additive technologies comparing their effects on tailpipe emissions; Investigation into the vehicle exhaust emissions of high percentage ethanol blends; Variability in hydrocarbon speciation measurements at low emission (ULEV) levels; and more.

  14. Linking Individuals to Digital Information

    NASA Astrophysics Data System (ADS)

    Seier, Shelly; Greer, David; Manes, Gavin

    As computer crime increases in scope and magnitude, it is imperative to develop techniques that can link individuals to specific computers, computer programs and electronic documents. Unfortunately, scientific techniques that can establish these links are limited at best. This paper demonstrates that computer use characteristics can be employed to establish strong, legitimate links between individuals and digital information. Certain characteristics can be used to identify individuals. Other characteristics may be used to create profiles that assist in eliminating suspects and reducing the scope of investigations.

  15. Short distance optical links: Analysis, demonstration and circuit design

    NASA Astrophysics Data System (ADS)

    Pappu, Anand Mohan

    Optical signaling has some fundamental advantages over electrical signaling. Some of these advantages like absence of parasitics have been utilized beneficially in long distance and medium distance interconnection networks. However, for optics to be useful in the highly optimized and constrained VLSI system space, we require more benefits from using optics. In this dissertation, I identify electrical isolation of optical interconnects as an additional benefit. I study how this advantage can make optical interconnects beneficial in modern VLSI systems at short distances and have taken a step towards solving chip-to-chip and intra-chip interconnection issues. I demonstrate using our proof-of-concept circuits, the benefits of using optical fanout in electrical links with fanout. I show improved signal latency with optical fanout even at link lengths of 200mum in a 0.25mum technology. This is the first physical demonstration of the advantages of using optics in silicon VLSI systems at these distances. I also demonstrated an advantage in energy-delay-squared product for fanout to more than 250 minimum sized inverters corresponding to a distance of 1.5 mm. I also demonstrate an important step towards physical implementation of our proposed short-distance optical links via our design of a silicon-based detector. I developed our detector in a commercial process and it uses a low supply voltage 1.8V. These features make our detector extremely low-cost and readily available in commercial processes. I also demonstrate opto-electronic integration of detectors and receivers in the same silicon chip and show operation at 1Gbps link bit rate. As a part of our circuit design efforts for optimal link design, I focused on creating process-invariant circuits. Fabrication related circuit variations lead to a significant power-performance-yield trade-off and introduce variability in the various branches of optical fanout. Addressing these issues is necessary in constructing a robust

  16. 25 CFR 215.17 - Additional information required.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Additional information required. 215.17 Section 215.17 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEAD AND ZINC MINING... interested in lead and zinc mining leases, or land under the jurisdiction of the Quapaw Indian Agency,...

  17. Prevention of Childhood Lead Toxicity.

    PubMed

    2016-07-01

    Blood lead concentrations have decreased dramatically in US children over the past 4 decades, but too many children still live in housing with deteriorated lead-based paint and are at risk for lead exposure with resulting lead-associated cognitive impairment and behavioral problems. Evidence continues to accrue that commonly encountered blood lead concentrations, even those below 5 µg/dL (50 ppb), impair cognition; there is no identified threshold or safe level of lead in blood. From 2007 to 2010, approximately 2.6% of preschool children in the United States had a blood lead concentration ≥5 µg/dL (≥50 ppb), which represents about 535 000 US children 1 to 5 years of age. Evidence-based guidance is available for managing increased lead exposure in children, and reducing sources of lead in the environment, including lead in housing, soil, water, and consumer products, has been shown to be cost-beneficial. Primary prevention should be the focus of policy on childhood lead toxicity. PMID:27325637

  18. Lead-based paint assessment

    SciTech Connect

    Lorie, C.; Cowdery, J.W.

    1994-12-31

    In 1977, The US consumer product safety commission banned the use of lead-based paint (LBP) in all industries, except the maritime industry which still has certain privileged uses. Unfortunately for property and building owners, the ban did not come soon enough. In response to this heightened awareness, several environmental market sectors addressing the issues have emerged. These include: residential; soil; commercial; water; and structures. The first and most important step in addressing the concerns posed by the existence of lead based contamination is to quantify the amount of lead-based product, to determine the location of the lead based product and the extent, if any, of lead based contamination, and to make recommendations for the remediation or abatement of the lead product and resultant contamination. In narrowing the focus of these issues, this paper discusses lead-based paint assessment; preparing and organizing the assessment, the regulatory considerations, assessment methodology, and presentation of results.

  19. Loss of Nfkb1 leads to early onset aging

    PubMed Central

    Crawley, Clayton D.; Cahill, Kirk E.; Pytel, Peter; Liang, Hua; Kang, Shijun; Weichselbaum, Ralph R.; Yamini, Bakhtiar

    2014-01-01

    NF-(B is a major regulator of age-dependent gene expression and the p50/NF-(B1 subunit is an integral modulator of NF-(B signaling. Here, we examined Nfkb1−/− mice to investigate the relationship between this subunit and aging. Although Nfkb1−/− mice appear similar to littermates at six months of age, by 12 months they have a higher incidence of several observable age-related phenotypes. In addition, aged Nfkb1−/− animals have increased kyphosis, decreased cortical bone, increased brain GFAP staining and a decrease in overall lifespan compared to Nfkb1+/+. In vitro, serially passaged primary Nfkb1−/− MEFs have more senescent cells than comparable Nfkb1+/+ MEFs. Also, Nfkb1−/− MEFs have greater amounts of phospho-H2AX foci and lower levels of spontaneous apoptosis than Nfkb1+/+, findings that are mirrored in the brains of Nfkb1−/− animals compared to Nfkb1+/+. Finally, in wildtype animals a substantial decrease in p50 DNA binding is seen in aged tissue compared to young. Together, these data show that loss of Nfkb1 leads to early animal aging that is associated with reduced apoptosis and increased cellular senescence. Moreover, loss of p50 DNA binding is a prominent feature of aged mice relative to young. These findings support the strong link between the NF-(B pathway and mammalian aging. PMID:25553648

  20. Loss of Nfkb1 leads to early onset aging.

    PubMed

    Bernal, Giovanna M; Wahlstrom, Joshua S; Crawley, Clayton D; Cahill, Kirk E; Pytel, Peter; Liang, Hua; Kang, Shijun; Weichselbaum, Ralph R; Yamini, Bakhtiar

    2014-11-01

    NF-κB is a major regulator of age-dependent gene expression and the p50/NF-κB1 subunit is an integral modulator of NF-κB signaling. Here, we examined Nfkb1-/- mice to investigate the relationship between this subunit and aging. Although Nfkb1-/- mice appear similar to littermates at six months of age, by 12 months they have a higher incidence of several observable age-related phenotypes. In addition, aged Nfkb1-/- animals have increased kyphosis, decreased cortical bone, increased brain GFAP staining and a decrease in overall lifespan compared to Nfkb1+/+. In vitro, serially passaged primary Nfkb1-/- MEFs have more senescent cells than comparable Nfkb1+/+ MEFs. Also, Nfkb1-/- MEFs have greater amounts of phospho-H2AX foci and lower levels of spontaneous apoptosis than Nfkb1+/+, findings that are mirrored in the brains of Nfkb1-/- animals compared to Nfkb1+/+. Finally, in wildtype animals a substantial decrease in p50 DNA binding is seen in aged tissue compared to young. Together, these data show that loss of Nfkb1 leads to early animal aging that is associated with reduced apoptosis and increased cellular senescence. Moreover, loss of p50 DNA binding is a prominent feature of aged mice relative to young. These findings support the strong link between the NF-κB pathway and mammalian aging.

  1. Addition of methanetrisulfonyl fluoride to unsaturated bonds

    SciTech Connect

    Yagupol'skii, Yu.L.; Gerus, I.I.; Savina, T.I.

    1988-06-10

    The reactions of methanetrisulfonyl fluoride, HC(SO/sub 2/F)/sub 3/ with acrylic acid derivatives lead to addition products containing the tris(fluorosulfonyl)methyl group, while methyl vinyl ketone gives an unstable adduct. The methyl ester of propiolic acid is converted to a mixture of cis- and trans-tris(fluorosulfonyl)-crotonic acid esters. The reaction of cyclohexene with methanesulfonyl fluoride leads to dimerization of the olefin and the cyclohexyl derivative is formed in low yield. Sulfonyl fluoride acts as catalyst for the conversion of cyclohexene to dimer and only a small portion of the cyclohexyl cation reacts with the weakly nucleophilic /sup /minus//C(SO/sub 2/F)/sub 3/ anion.

  2. Lead pollution in Tokyo--the pigeon reflects its amelioration

    SciTech Connect

    Ohi, G.; Seki, H.; Minowa, K.; Ohsawa, M.; Mizoguchi, I; Sugimori, F.

    1981-10-01

    To monitor lead pollution in the Tokyo metropolitan area, we checked the feral pigeon Columba livia var. blood lead levels and delta-aminolevulinic acid dehydratase activities (ALA-D) of the erythrocytes over the period from 1971 to 1980. The pigeons gave much more magnified pictures of lead pollution than atmospheric lead concentrations indicated, even after addition of tetraethyl lead to the regular gasoline was totally banned in 1975. Since the biological half-life of lead in the pigeon was determined to be relatively short, this was considered mainly due to their habit of ingesting gizzard stones polluted with lead. The amelioration of lead pollution, reflected in the pigeons in downtown Tokyo, was observed with a few years of lag time after the improvement of the atmospheric lead concentration was first noted.

  3. Links and opportunities

    NASA Astrophysics Data System (ADS)

    1999-09-01

    At the end of June a new website was launched to enable young people to get involved with the UK's national Foresight programme and to help shape the future. `School of the Future - Young people with Foresight' will provide young people with the means to contribute to the national programme which develops scenarios of the future, looking at possible needs, opportunities or threats and deciding what should be done now to make sure these challenges can be met. The site can be found at www.asset.org.uk and it will be run by the Association for Schools' Science, Engineering and Technology (ASSET). The latest round of Foresight began in April and panels are taking a look at the aging population, crime prevention, built environment and transport, aerospace and systems, energy and the natural environment, information, communications and media, materials and sustainable development, amongst other topics. Information about Foresight activities and events can be obtained from the Office of Science and Technology or the Foresight Knowledge pool at www.foresight.gov.uk. The pool will act as a unique and freely accessible electronic library of views and information about the future that young people will be able to draw on for assistance and reference material. Futher assistance for students will also be on offer from museums and art galleries from now on, thanks to additional funding which has been made available over the next three years. Forty museums and galleries will share up to #2.5m for projects intended to improve students' literacy, numeracy and science skills as well as their understanding of history and art. Examples of the imaginative projects which have been put forward include use of the large collection of steam engines at the Museum of Science and Industry in Manchester to assist boys' science and literacy skills. The Museum of London will be working with over 2000 schools in the South East to provide materials for the schools' own mini-museums on the Romans

  4. Electrophoretic analysis of Allium alien addition lines.

    PubMed

    Peffley, E B; Corgan, J N; Horak, K E; Tanksley, S D

    1985-12-01

    Meiotic pairing in an interspecific triploid of Allium cepa and A. fistulosum, 'Delta Giant', exhibits preferential pairing between the two A. cepa genomes, leaving the A. fistulosum genome as univalents. Multivalent pairing involving A. fistulosum chromosomes occurs at a low level, allowing for recombination between the genomes. Ten trisomies were recovered from the backcross of 'Delta Giant' x A. cepa cv., 'Temprana', representing a minimum of four of the eight possible alien addition lines. The alien addition lines possessed different A. fistulosum enzyme markers. Those markers, Adh-1, Idh-1 and Pgm-1 reside on different A. fistulosum chromosomes, whereas Pgi-1 and Idh-1 may be linked. Diploid, trisomic and hyperploid progeny were recovered that exhibited putative pink root resistance. The use of interspecific plants as a means to introgress A. fistulosum genes into A. cepa appears to be successful at both the trisomic and the diploid levels. If introgression can be accomplished using an interspecific triploid such as 'Delta Giant' to generate fertile alien addition lines and subsequent fertile diploids, or if introgression can be accomplished directly at the diploid level, this will have accomplished gene flow that has not been possible at the interspecific diploid level.

  5. Lead poisoning prevention for preschool settings: a program template.

    PubMed

    Saatciler, Eda

    2015-01-01

    Lead is a naturally occurring metal that has been linked to neurological impairments and insanity since ancient times. It has been used in many products such as paint, pipes, and ceramics and still remains a public hazard. Young children between the ages of 6 months and 6 years with lead-contaminated housing are at the greatest risk for cognitive, neurological, and behavioral health problems. Briefly, lead exposure is around us and it correlates with learning deficits and violent behaviors as these children become adults. It also can cause anemia, abdominal pain, seizure, and death.

  6. Lead poisoning prevention for preschool settings: a program template.

    PubMed

    Saatciler, Eda

    2015-01-01

    Lead is a naturally occurring metal that has been linked to neurological impairments and insanity since ancient times. It has been used in many products such as paint, pipes, and ceramics and still remains a public hazard. Young children between the ages of 6 months and 6 years with lead-contaminated housing are at the greatest risk for cognitive, neurological, and behavioral health problems. Briefly, lead exposure is around us and it correlates with learning deficits and violent behaviors as these children become adults. It also can cause anemia, abdominal pain, seizure, and death. PMID:25626240

  7. Color Addition and Subtraction Apps

    ERIC Educational Resources Information Center

    Ruiz, Frances; Ruiz, Michael J.

    2015-01-01

    Color addition and subtraction apps in HTML5 have been developed for students as an online hands-on experience so that they can more easily master principles introduced through traditional classroom demonstrations. The evolution of the additive RGB color model is traced through the early IBM color adapters so that students can proceed step by step…

  8. Saturn and Enceladus Electrical Link

    NASA Video Gallery

    This animated graphic shows how Saturn and its moon Enceladus are electrically linked. Magnetic field lines, invisible to the human eye but detectable by the fields and particles instruments on NAS...

  9. Lead exposure, lead poisoning, and lead regulatory standards in China, 1990-2005.

    PubMed

    Ye, Xibiao; Wong, Otto

    2006-11-01

    This article presents a summary of lead exposure levels and lead poisoning at workplaces in China reported in the Chinese medical literature between 1990 and 2005. A comprehensive literature search identified 618 papers reporting lead exposure and lead poisoning data. The data were analyzed in terms of time period, type of industry, size of factory, and task or process. In 2002 the new Occupational Diseases Prevention and Control Act was passed in China, with new provisions specifically for regulatory enforcement. Therefore, a comparison of lead exposure levels and lead poisoning rates before and after the 2002 Act will shed some light on the effectiveness of the new regulation. The reported lead exposure levels covered a wide range; some measurements were in excess of 250 mg/m(3), which was orders-of-magnitude higher than the occupational exposure levels (OELs) for lead in China. The overall arithmetic mean, median, and geometric mean were 0.92, 0.25, and 0.24 mg/m(3), respectively. Approximately 53.7% of the averages reported in the papers were above the national OELs. The data demonstrated that many facilities in the lead industries reported in the literature were not in compliance with the OELs. Similarly, there appeared to be only a minor impact of the 2002 Act on the reduction of occupational lead poisoning in China. The lead poisoning rates reported in the literature were well above 30%. Judging by the lead exposure levels and the lead poisoning rates, the current overall occupational health monitoring system appears inadequate, lacking the necessary enforcement. The 2002 Act, without the necessary enforcement, did not appear to have a major impact on either lead exposures or lead poisoning in China. Much work in enforcing the 2002 Act remains to be done.

  10. Radar Microwave Link (RML) electromagnetic compatibility measurements

    NASA Astrophysics Data System (ADS)

    Dong, J. G.

    1980-03-01

    Two different microwave relay transmitter and receiver combinations operating in the frequency ranges of 7.125 to 8.4 GHz and 14.4 to 15.25 GHz were tested. Measurements to determine interference characteristics included: receiver off channel rejection; receiver intermodulation; transmitter spectrums; transmitter intermodulation; and second harmonics. Results indicate that adjacent frequency spacing should be at least 20 MHz and 50 MHz for radar microwave link-4 and TerraCom equipment, respectively. Additional measurements are rec-om-mended on new equipment in the 14.4 to 15.25 GHz range for valid criteria for the handbook in preparation.

  11. Manipulation of microstructure in laser additive manufacturing

    NASA Astrophysics Data System (ADS)

    Bai, Shuang; Yang, Lihmei; Liu, Jian

    2016-05-01

    In this paper, additive manufacturing (AM) of tungsten parts is investigated by using femtosecond fiber lasers. For the first time, manipulating microstructures of AM parts is systematically investigated and reported. Various processing conditions are studied, which leads to desired characteristics in terms of morphology, porosity, hardness, and microstructural and mechanical properties of the processed components. Fully dense tungsten part with refined grain and increased hardness was obtained for femtosecond laser, compared with parts made with different pulse widths and CW laser. Micro-hardness is investigated for the fabricated samples. This can greatly benefit to the make of complicated structures and materials that could not be achieved before.

  12. Chemical speciation of lead dust associated with primary lead smelting.

    PubMed Central

    Spear, T M; Svee, W; Vincent, J H; Stanisich, N

    1998-01-01

    The research presented in this article assessed geochemical factors relating to dust produced during primary lead smelting. Bulk dust samples and size-selective airborne dust samples were collected from four areas of a primary lead smelter and analyzed by X-ray diffraction and sequential chemical extraction. X-ray diffraction showed that the smelter dusts were composed primarily of sulfides, oxides, sulfates, and silicates of metal ores, with galena being the primary dust component. Sequential extraction revealed the solubility of lead compounds at less than 7% in the exchangeable and mildly acidic steps for the bulk dusts collected from four smelter areas. The later steps of the extraction procedure were more effective in dissolving the lead compounds associated with the bulk dust samples, with 43%, 26%, and 8% of the total lead, in the ore storage, sinter, and blast/dross smelter areas, respectively, being extracted in the residual step. Sequential extraction of coarse airborne dust samples from the ore storage and sinter plant showed that 1.2% and 4.1% of the total lead, respectively, was exchangeable. The finer particle size fractions from these areas of the smelter showed higher percentages of exchangeable lead. Of the course airborne dust from the blast/dross furnace processes, 65% of the total lead was exchangeable. However, the largest percentage of lead from these areas was associated with the finer particle-size fractions. If lead bioavailability is related to its solubility as determined through sequential extraction, the health hazards associated with lead exposure may be appreciably enhanced in the blast and dross furnace processes. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:9721256

  13. Theory of a weak-link superconductor-ferromagnet Josephson structure

    NASA Astrophysics Data System (ADS)

    Gelhausen, J.; Eschrig, M.

    2016-09-01

    We propose a model for the theoretical description of a weak-link Josephson junction, in which the weak link is spin-polarized due to proximity to a ferromagnetic metal [S-(F |S )-S, where S is a superconductor and F is a ferromagnetic metal]. Employing Usadel transport theory appropriate for diffusive systems, we show that the weak link is described within the framework of Andreev circuit theory by an effective self-energy resulting from the implementation of spin-dependent boundary conditions. This leads to a considerable simplification of the model, and allows for an efficient numerical treatment. As an application of our model, we show numerical calculations of important physical observables such as the local density of states, proximity-induced minigaps, spin-magnetization, and the phase and temperature dependence of Josephson currents of the S-(F |S )-S system. We discuss multivalued current-phase relationships at low temperatures as well as their crossover to sinusoidal form at high temperatures. Additionally, we numerically treat (S-F-S) systems that exhibit a magnetic domain wall in the F region and calculate the temperature-dependence of the critical currents.

  14. Emotional reactivity and the association between psychopathy-linked narcissism and aggression in detained adolescent boys.

    PubMed

    Muñoz Centifanti, Luna C; Kimonis, Eva R; Frick, Paul J; Aucoin, Katherine J

    2013-05-01

    Different patterns of emotional reactivity characterize proactive and reactive functions of aggressive behavior, and theory also suggests a link of both types with narcissism. How people with narcissistic traits respond emotionally to competitive scenarios could influence their aggressiveness. Participants were 85 adolescent boys from a detention center. Several indices of emotional functioning were assessed, including attentional bias to negative emotional stimuli and psychophysiological responding. In addition, we included self-report and laboratory measures of aggression and measures of psychopathy-linked narcissism, callous-unemotional traits, and impulsivity. Psychopathy-linked narcissism was uniquely related to unprovoked aggression (i.e., proactive aggression) and to heightened attention to pictures depicting others' distress. Compared with those scoring low on narcissism, those high on narcissism, who were the least physiologically reactive group, evinced greater proactive aggression, whereas those showing a pattern of coactivation (i.e., sympathetic and parasympathetic autonomic reactivity) evinced greater reactive aggression. Results are consistent with descriptions of narcissistic individuals as being hypervigilant to negative cues and exhibiting poor emotion regulation. These characteristics may lead to aggressive and violent behavior aimed at maintaining dominance over others.

  15. Application of cross-linked and hydrolyzed arabinoxylans in baking of model rye bread.

    PubMed

    Buksa, Krzysztof; Nowotna, Anna; Ziobro, Rafał

    2016-02-01

    The role of water extractable arabinoxylan with varying molar mass and structure (cross-linked vs. hydrolyzed) in the structure formation of rye bread was examined using a model bread. Instead of the normal flour, the dough contained starch, arabinoxylan and protein, which were isolated from rye wholemeal. It was observed that the applied mixes of these constituents result in a product closely resembling typical rye bread, even if arabinoxylan was modified (by cross-linking or hydrolysis). The levels of arabinoxylan required for bread preparation depended on its modification and mix composition. At 3% protein, the maximum applicable level of poorly soluble cross-linked arabinoxylan was 3%, as higher amounts of this preparation resulted in an extensively viscous dough and diminished bread volume. On the other hand highly soluble, hydrolyzed arabinoxylan could be used at a higher level (6%) together with larger amounts of rye protein (3% or 6%). Further addition of arabinoxylan leads to excessive water absorption, resulting in a decreased viscosity of the dough during baking and insufficient gas retention. PMID:26304439

  16. Emotional reactivity and the association between psychopathy-linked narcissism and aggression in detained adolescent boys.

    PubMed

    Muñoz Centifanti, Luna C; Kimonis, Eva R; Frick, Paul J; Aucoin, Katherine J

    2013-05-01

    Different patterns of emotional reactivity characterize proactive and reactive functions of aggressive behavior, and theory also suggests a link of both types with narcissism. How people with narcissistic traits respond emotionally to competitive scenarios could influence their aggressiveness. Participants were 85 adolescent boys from a detention center. Several indices of emotional functioning were assessed, including attentional bias to negative emotional stimuli and psychophysiological responding. In addition, we included self-report and laboratory measures of aggression and measures of psychopathy-linked narcissism, callous-unemotional traits, and impulsivity. Psychopathy-linked narcissism was uniquely related to unprovoked aggression (i.e., proactive aggression) and to heightened attention to pictures depicting others' distress. Compared with those scoring low on narcissism, those high on narcissism, who were the least physiologically reactive group, evinced greater proactive aggression, whereas those showing a pattern of coactivation (i.e., sympathetic and parasympathetic autonomic reactivity) evinced greater reactive aggression. Results are consistent with descriptions of narcissistic individuals as being hypervigilant to negative cues and exhibiting poor emotion regulation. These characteristics may lead to aggressive and violent behavior aimed at maintaining dominance over others. PMID:23627957

  17. Application of cross-linked and hydrolyzed arabinoxylans in baking of model rye bread.

    PubMed

    Buksa, Krzysztof; Nowotna, Anna; Ziobro, Rafał

    2016-02-01

    The role of water extractable arabinoxylan with varying molar mass and structure (cross-linked vs. hydrolyzed) in the structure formation of rye bread was examined using a model bread. Instead of the normal flour, the dough contained starch, arabinoxylan and protein, which were isolated from rye wholemeal. It was observed that the applied mixes of these constituents result in a product closely resembling typical rye bread, even if arabinoxylan was modified (by cross-linking or hydrolysis). The levels of arabinoxylan required for bread preparation depended on its modification and mix composition. At 3% protein, the maximum applicable level of poorly soluble cross-linked arabinoxylan was 3%, as higher amounts of this preparation resulted in an extensively viscous dough and diminished bread volume. On the other hand highly soluble, hydrolyzed arabinoxylan could be used at a higher level (6%) together with larger amounts of rye protein (3% or 6%). Further addition of arabinoxylan leads to excessive water absorption, resulting in a decreased viscosity of the dough during baking and insufficient gas retention.

  18. The D-linking effect on extraction from islands and non-islands

    PubMed Central

    Goodall, Grant

    2015-01-01

    “D-linked” wh-phrases such as which car are known to increase the acceptability of sentences with island violations. One influential account of this attributes the effect to working memory: the D-linked filler is easier to retrieve at the site of the gap and this leads to the amelioration in acceptability. Such an account predicts that this effect should occur in general with non-trivial wh-dependencies, not just in island environments. An experiment is presented here to test this prediction. Wh-questions with both D-linked and bare wh-phrases and with both island and non-island embedded clauses are presented to participants, who rate their acceptability on a 7-point scale. Results show that D-linking significantly increases acceptability in both island and non-island environments, in accord with analyses that attribute the effect to working memory. In addition, the increase in acceptability is uniform in both types of environments, suggesting that the island effect itself may not be attributable to working memory. PMID:25601844

  19. Khovanov homology of graph-links

    SciTech Connect

    Nikonov, Igor M

    2012-08-31

    Graph-links arise as the intersection graphs of turning chord diagrams of links. Speaking informally, graph-links provide a combinatorial description of links up to mutations. Many link invariants can be reformulated in the language of graph-links. Khovanov homology, a well-known and useful knot invariant, is defined for graph-links in this paper (in the case of the ground field of characteristic two). Bibliography: 14 titles.

  20. Integrative modelling reveals mechanisms linking productivity and plant species richness.

    PubMed

    Grace, James B; Anderson, T Michael; Seabloom, Eric W; Borer, Elizabeth T; Adler, Peter B; Harpole, W Stanley; Hautier, Yann; Hillebrand, Helmut; Lind, Eric M; Pärtel, Meelis; Bakker, Jonathan D; Buckley, Yvonne M; Crawley, Michael J; Damschen, Ellen I; Davies, Kendi F; Fay, Philip A; Firn, Jennifer; Gruner, Daniel S; Hector, Andy; Knops, Johannes M H; MacDougall, Andrew S; Melbourne, Brett A; Morgan, John W; Orrock, John L; Prober, Suzanne M; Smith, Melinda D

    2016-01-21

    How ecosystem productivity and species richness are interrelated is one of the most debated subjects in the history of ecology. Decades of intensive study have yet to discern the actual mechanisms behind observed global patterns. Here, by integrating the predictions from multiple theories into a single model and using data from 1,126 grassland plots spanning five continents, we detect the clear signals of numerous underlying mechanisms linking productivity and richness. We find that an integrative model has substantially higher explanatory power than traditional bivariate analyses. In addition, the specific results unveil several surprising findings that conflict with classical models. These include the isolation of a strong and consistent enhancement of productivity by richness, an effect in striking contrast with superficial data patterns. Also revealed is a consistent importance of competition across the full range of productivity values, in direct conflict with some (but not all) proposed models. The promotion of local richness by macroecological gradients in climatic favourability, generally seen as a competing hypothesis, is also found to be important in our analysis. The results demonstrate that an integrative modelling approach leads to a major advance in our ability to discern the underlying processes operating in ecological systems. PMID:26760203