Science.gov

Sample records for additional links lead

  1. 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...

  2. 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...

  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, 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...

  5. An Ontology Service for Linked Environments for Atmospheric Discovery (LEAD)

    NASA Astrophysics Data System (ADS)

    Ramachandran, R.; Movva, S.

    2005-12-01

    An Ontology encodes concepts and the relationships among them. From a machine learning perspective, it is viewed as a formal, explicit specification of a shared conceptualization. Linked Environments for Atmospheric Discovery (LEAD) is a large NSF Information Technology Research (ITR) initiative to provide scalable, integrated gird framework for use in accessing, preparing, assimilating, predicting, analyzing and managing a broad array of meteorological and related information independent of format and physical location. An ontology that focuses on mesoscale meteorology is currently being designed and developed for LEAD. It uses the Semantic Web for Earth and Environmental Terminology - ontology (SWEET, Rob Raskin - JPL) as a building block and additional concepts for mesoscale meteorology are being added. An Ontology Inference Service (OIS) is also developed to provide querying capabilities on the LEAD Ontology. The drivers for developing such an ontology and inference service specifically for LEAD are many. The LEAD ontology serves as a common vocabulary to allow interoperability for metadata exchange between different LEAD catalogs. Coupled with these LEAD catalogs, the OIS will also provide a 'yellow pages' search capability to the end users. The OIS provides capabilities to search for similar and related concepts for a particular concept. This is essentially, searching with semantic meanings rather than searching with keywords. Thus allowing users to search for datasets without actually having to know and use the specific data parameter names in the catalogs. Finally, the OIS serves as a stand-alone smart search system for the atmospheric domain, specifically mesoscale meteorology. This smart search service collates the definition of a user's search term, useful datasets, related concepts, useful websites and additional related information. It serves as an educational portal for both students and researchers in LEAD.

  6. Thiol-copper(I) and disulfide-dicopper(I) complex O2-reactivity leading to sulfonate-copper(II) complex or the formation of a cross-linked thioether-phenol product with phenol addition.

    PubMed

    Lee, Yunho; Lee, Dong-Heon; Sarjeant, Amy A Narducci; Karlin, Kenneth D

    2007-11-01

    In order to better understand copper mediated oxidative chemistry via ligand-Cu(I)/O(2) reactivity employing S-donor ligands for copper, O(2)-reactivity studies of the copper(I) complexes (1 and 2, Chart 2) have been carried out with a tridentate N(2)S thiol ligand (1-(N-methyl-N-(2-(pyridin-2-yl)ethyl)amino)propane-2-thiol; L(SH)) or its oxidized disulfide form (L(SS)). Reactions of [L(SH)Cu(I)](+) (1) and [L(SS)(Cu(I))(2)(X)(2)](2+) (2) with O(2) give approximately 90% and approximately 70% yields of [L(SO3)Cu(II)(MeOH)(2)](+) (3), respectively, where L(SO3) is S-oxygenated sulfonate; 3 was characterized by electrospray ionization (ESI) mass spectrometry and X-ray crystallography. Mimicking TyrCys galactose oxidase cofactor biogenesis, a new C-S bond is formed (within new thioether moiety L(SPhOH)) from cuprous complex (both 1 and 2) dioxygen reactivity in the presence of 2,4-tBu(2)-phenolate. In addition, the disulfide ligand (L(SS)) reacts with 2equiv. cupric ion salts and the phenolate to efficiently give the cross-linked product L(SPhOH) in high yield (>90%) under anaerobic conditions. Separately, complex [L(SPhO)Cu(II)(ClO(4))] (4), possessing the cross-linked L(SPhOH), was characterized by ESI mass spectrometry and X-ray crystallography.

  7. 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.

  8. 40 CFR 51.117 - Additional provisions for lead.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... smelters, Lead gasoline additive plants, Lead-acid storage battery manufacturing plants that produce 2,000 or more batteries per day. Any other stationary source that actually emits 25 or more tons per year... modified rollback model for the demonstration of attainment as a minimum, but may use an...

  9. Justification for Shielded Receiver Tube Additional Lead Shielding

    SciTech Connect

    BOGER, R.M.

    2000-04-11

    In order to reduce high radiation dose rates encountered when core sampling some radioactive waste tanks the addition of 240 lbs. of lead shielding is being considered to the shielded receiver tube on core sample trucks No.1, No.3 and No.4. The lead shielding is 4 inch diameter x 1/2 inch thick half rounds that have been installed around the SR tube over its' full length. Using three unreleased but independently reviewed structural analyses HNF-6018 justifies the addition of the lead shielding.

  10. Effect of mixed additives on lead-acid battery electrolyte

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Arup; Basumallick, Indra Narayan

    This paper describes the corrosion behaviour of the positive and negative electrodes of a lead-acid battery in 5 M H 2SO 4 with binary additives such as mixtures of phosphoric acid and boric acid, phosphoric acid and tin sulphate, and phosphoric acid and picric acid. The effect of these additives is examined from the Tafel polarisation curves, double layer capacitance and percentage of inhibition efficiency. A lead salt battery has been fabricated replacing the binary mixture with an alternative electrolyte and the above electrochemical parameters have been evaluated for this lead salt battery. The results are explained in terms of H + ion transport and the morphological change of the PbSO 4 layer.

  11. 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.

  12. Leading the implementation of health links in Ontario.

    PubMed

    Evans, Jenna M; Grudniewicz, Agnes; Wodchis, Walter P; Baker, G Ross

    2014-01-01

    Ontario's Health Links initiative aims to coordinate and improve care for complex patients. In this paper, we draw from interviews with leaders and providers from Health Links and Local Health Integration Networks to discuss key leadership and governance issues influencing the implementation and success of the Health Links. We close with a short discussion of how leaders manage ambiguity by creating a context that supports change and the delivery of integrated care.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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…

  19. Evaluation of additional lead shielding in protecting the physician from radiation during cardiac interventional procedures.

    PubMed

    Chida, Koichi; Morishima, Yoshiaki; Katahira, Yoshiaki; Chiba, Hiroo; Zuguchi, Masayuki

    2005-12-20

    Since cardiac interventional procedures deliver high doses of radiation to the physician, radiation protection for the physician in cardiac catheterization laboratories is very important. One of the most important means of protecting the physician from scatter radiation is to use additional lead shielding devices, such as tableside lead drapes and ceiling-mounted lead acrylic protection. During cardiac interventional procedures (cardiac IVR), however, it is not clear how much lead shielding reduces the physician dose. This study compared the physician dose [effective dose equivalent (EDE) and dose equivalent (DE)] with and without additional shielding during cardiac IVR. Fluoroscopy scatter radiation was measured using a human phantom, with an ionization chamber survey meter, with and without additional shielding. With the additional shielding, fluoroscopy scatter radiation measured with the human phantom was reduced by up to 98%, as compared with that without. The mean EDE (whole body, mean+/-SD) dose to the operator, determined using a Luxel badge, was 2.55+/-1.65 and 4.65+/-1.21 mSv/year with and without the additional shielding, respectively (p=0.086). Similarly, the mean DE (lens of the eye) to the operator was 15.0+/-9.3 and 25.73+/-5.28 mSv/year, respectively (p=0.092). In conclusion, although tableside drapes and lead acrylic shields suspended from the ceiling provided extra protection to the physician during cardiac IVR, the reduction in the estimated physician dose (EDE and DE) during cardiac catheterization with additional shielding was lower than we expected. Therefore, there is a need to develop more ergonomically useful protection devices for cardiac IVR.

  20. Implantation of additional defibrillation lead into the coronary sinus: an effective method of decreasing defibrillation threshold.

    PubMed

    Wilczek, Rajmund; Swiątkowski, Maciej; Czepiel, Aleksandra; Sterliński, Maciej; Makowska, Ewa; Kułakowski, Piotr

    2011-01-01

    We report a case of successful implantation of an additional defibrillation lead into the coronary sinus due to high defibrillation threshold (DFT) in a seriously ill patient with a history of extensive myocardial infarction referred for implantable cardioverter- defibrillator implantation after an episode of unstable ventricular tachycardia. All previous attempts to reduce DFT, including subcutaneous electrode implantation, had been unsuccessful.

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

    PubMed

    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(-1) well(-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.

  2. Evaluating the time and source of hydrocarbon additions to soils using lead isotopes and historical changes in industrial lead sources

    SciTech Connect

    Hurst, R.W. California State Univ., Los Angeles, CA )

    1994-04-01

    Isotopic analysis of anthropogenic Pb in well-dated, southern California coastal sediments have been integrated with historical changes in ore Pb sources to produce calibration curves (206Pb/207Pb vs. time) that allow us to model the time anthropogenic Pb was added to a soil horizon. The major, historical sources of anthropogenic Pb in southern California are fossil fuels (e.g. gasoline). Hence, Pb model ages (LABILE model; Los Angeles Borderland Industrial Lead) provide time constraints on Pb deposition from fossil fuel combustion via airborne deposition, runoff, and/or sewage outfall in this region. The correlation between the LABILE model age and known times of anthropogenic Pb additions at 17 specific sites is good (r = 0.978); the accuracy of the method ranges from one to five years in the post-1960 time interval. Factors influencing accuracy include analytical uncertainties in Pb isotopic measurements ([<=]0.1%), the scatter in isotopic ratios of anthropogenic Pb (circa 0.2%), and the uncertainty in the sediment age used to calibrate the method (0-15 yr). At one site three statistically distinguishable events were identified; they correlate with residential development (1968), airborne vehicular Pb deposition (1983), and site remediation (1991). Gasoline incursions at two tests sites have been dated accurately ([+-] 1 yr). The limitations of the LABILE model (geographic, age, types of hydrocarbons, and industry to which it applies) are now under investigation.

  3. In search of new lead compounds for trypanosomiasis drug design: A protein structure-based linked-fragment approach

    NASA Astrophysics Data System (ADS)

    Verlinde, Christophe L. M. J.; Rudenko, Gabrielle; Hol, Wim G. J.

    1992-04-01

    A modular method for pursuing structure-based inhibitor design in the framework of a design cycle is presented. The approach entails four stages: (1) a design pathway is defined in the three-dimensional structure of a target protein; (2) this pathway is divided into subregions; (3) complementary building blocks, also called fragments, are designed in each subregion; complementarity is defined in terms of shape, hydrophobicity, hydrogen bond properties and electrostatics; and (4) fragments from different subregions are linked into potential lead compounds. Stages (3) and (4) are qualitatively guided by force-field calculations. In addition, the designed fragments serve as entries for retrieving existing compounds from chemical databases. This linked-fragment approach has been applied in the design of potentially selective inhibitors of triosephosphate isomerase from Trypanosoma brucei, the causative agent of sleeping sickness.

  4. 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.

  5. 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....

  6. Linked Environments for Atmospheric Discovery (LEAD): A Cyberinfrastructure for Mesoscale Meteorology Research and Education

    NASA Astrophysics Data System (ADS)

    Droegemeier, K.

    2004-12-01

    A new National Science Foundation Large Information Technology Research (ITR) grant - known as Linked Environments for Atmospheric Discovery (LEAD) - has been funded to facilitate the identification, access, preparation, assimilation, prediction, management, analysis, mining, and visualization of a broad array of meteorological data and model output, independent of format and physical location. A transforming element of LEAD is dynamic workflow orchestration and data management, which will allow use of analysis tools, forecast models, and data repositories as dynamically adaptive, on-demand systems that can a) change configuration rapidly and automatically in response to weather; b) continually be steered by new data; c) respond to decision-driven inputs from users; d) initiate other processes automatically; and e) steer remote observing technologies to optimize data collection for the problem at hand. Having been in operation for slightly more than a year, LEAD has created a technology roadmap and architecture for developing its capabilities and placing them within the academic and research environment. Further, much of the LEAD infrastructure being developed for the WRF model, particularly workflow orchestration, will play a significant role in the nascent WRF Developmental Test Bed Center located at NCAR. This paper updates the status of LEAD (e.g., the topics noted above), its ties with other community activities (e.g., CONDUIT, THREDDS, MADIS, NOMADS), and the manner in which LEAD technologies will be made available for general use. Each component LEAD application is being created as a standards-based Web service that can be run in stand-alone configuration or chained together to build an end-to-end environment for on-demand, real time NWP. We describe in this paper the concepts, implementation plans, and expected impacts of LEAD, the underpinning of which will be a series of interconnected, heterogeneous virtual IT "Grid environments" designed to provide a

  7. Investigations of the negative plate of lead/acid cells 1. Selection of additives

    NASA Astrophysics Data System (ADS)

    Saakes, Michel; J. Van Duin, Pieter; C. P. Ligtvoet, Alexander; Schmal, Dick

    A procedure is proposed for the selection of inhibitors and expanders used as additives for the negative plate of the lead/acid battery. Inhibitors were selected by performing d.c. and a.c. measurements at pure metals (Cu, Sb, Ag), which are assumed to act as local active sites for the hydrogen-evolution reaction at the negative plate. From this study anisaldehyde was found to show strong preferential adsorption at Cu and Sb. Expanders were selected using a.c. impedance measurements at a Pb electrode at a low anodic discharge current. Selected expanders were Indulin C and Na-1-naphtol-4-sulfonate. From the impedance measurements information was obtained not only on the expander action but also on the effect of the additive on the double layer and the diffusion properties of lead sulfate. From a study on the concentration dependence of the expander (Na-1-naphtol-4-sulfonate) an optimal effect was found at a concentration of about 600 ppm.

  8. A New Cross-Link for an Old Cross-Linking Drug: The Nitrogen Mustard Anticancer Agent Mechlorethamine Generates Cross-Links Derived from Abasic Sites in Addition to the Expected Drug-Bridged Cross-Links.

    PubMed

    Nejad, Maryam Imani; Johnson, Kevin M; Price, Nathan E; Gates, Kent S

    2016-12-20

    Nitrogen mustard anticancer drugs generate highly reactive aziridinium ions that alkylate DNA. Monoadducts arising from reaction with position N7 of guanine residues are the major DNA adducts generated by these agents. Interstrand cross-links in which the drug bridges position N7 of two guanine residues are formed in low yields relative to those of the monoadducts but are generally thought to be central to medicinal activity. The N7-alkylguanine residues generated by nitrogen mustards are depurinated to yield abasic (Ap) sites in duplex DNA. Here, we show that Ap sites generated by the nitrogen mustard mechlorethamine lead to interstrand cross-links of a type not previously associated with this drug. Gel electrophoretic data were consistent with early evolution of the expected drug-bridged cross-links, followed by the appearance of Ap-derived cross-links. The evidence is further consistent with a reaction pathway involving alkylation of a guanine residue in a 5'-GT sequence, followed by depurination to generate the Ap site, and cross-link formation via reaction of the Ap aldehyde residue with the opposing adenine residue at this site [Price, N. E., Johnson, K. M., Wang, J., Fekry, M. I., Wang, Y., and Gates, K. S. (2014) J. Am. Chem. Soc. 136, 3483-3490]. The monofunctional DNA-alkylating agents 2-chloro-N,N-diethylethanamine 5, (2-chloroethyl)ethylsulfide 6, and natural product leinamycin similarly were found to induce the formation of Ap-derived cross-links in duplex DNA. This work provides the first characterization of Ap-derived cross-links at sequences in which a cytosine residue is located directly opposing the Ap site. Cross-linking processes of this type could be relevant in medicine and biology because Ap sites with directly opposing cytosine residues occur frequently in genomic DNA via spontaneous or enzymatic depurination of guanine and N7-alkylguanine residues.

  9. 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.

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

    PubMed

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

    2015-03-02

    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.

  11. 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.

  12. Lead

    MedlinePlus

    ... Worker, or other abatement discipline Lead in drinking water Lead air pollution Test your child Check and maintain your home Find a Lead-Safe Certified firm Before you renovate Before you buy or rent a home built before 1978 Test your home's drinking water Test for lead in paint, dust or soil ...

  13. 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.

  14. New Rare Earth Antiknock Additives that are Potential Substitutes for Tetraethyl Lead

    DTIC Science & Technology

    1974-12-01

    Io. Dola Enter when tested by the Supercharge Method (ASTM 0909-67). The significance of this result, compared to the inferior performance of Ce... METHODS OF ADDITIVE INTRODUCTION ...... ................... .... 45 X DISCUSSION .................... 46 1. PERFORMANCE...ISOOCTANE PRIMARY REFERENCE FUEL BY THE SUPERCHARGE METHOD , ASTM D 909-67 .. . 18 2 ANTIKNOCK EFFECTIVENESS AS A FUNCTION OF ADDITIVE CONCENTRATION FOR Ce

  15. Topological Constraints on Identifying Additive Link Metrics via End-to-end Paths Measurements

    DTIC Science & Technology

    2012-09-20

    U.K. Ministry of Defence or the U.K. Government. The U.S. and U.K. Governments are authorized to reproduce and distribute reprints for Government...MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION /AVAILABILITY STATEMENT Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES...with (partially) unknown probabil- ity distributions , and apply various parametric/nonparametric techniques to estimate the link metric distributions

  16. Effect of Ag, Ni and Bi Additions on Solderability of Lead-Free Solders

    NASA Astrophysics Data System (ADS)

    Nobari, Amir Hossein; Maalekian, Mehran; Seelig, Karl; Pekguleryuz, Mihriban

    2017-01-01

    In this study, the effects of Ag, Ni and Bi additions on the melting, solidification, fluidity and wetting behavior of Sn-0.7Cu base solder alloy are studied. The addition of a small amount of Ni reduces the undercooling and improves the feeding distance (fluidity length); however, Ni does not improve the wetting and the spreading performance. The effect of Ni on the fluidity length of Ag-containing Sn-0.7Cu (SAC alloy) is marginal. Bi and Ag both improve wetting performance and also lower the melting temperature; however, they do not improve the fluidity; instead, they reduce the maximum length of fluidity.

  17. Lead

    MedlinePlus

    ... ATSDR Board of Scientific Counselors Lead in the environment: Agency for Toxic Substances and Disease Registry (ATSDR) Federal partner agencies: Department of Housing and Urban Development (HUD) and U.S. Environmental Protection Agency (EPA) Data, ...

  18. 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.

  19. 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.

  20. 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.

  1. 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

    2015-11-06

    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.

  2. Influence of polyethylene glycol-300 addition on nanostructured lead sulfide thin films properties

    NASA Astrophysics Data System (ADS)

    Kaci, S.; Keffous, A.; Trari, M.; Menari, H.; Manseri, A.; Mahmoudi, B.; Guerbous, L.

    2010-09-01

    The concentration of polyethylene glycol-300 was found to play a crucial role in the formation of nanoparticles in PbS-chemical bath deposition process. We report here an endeavor to set up a relation between the variation of lead sulfide (PbS) nanocrystalline thin film properties, grown by (CBD) process at room temperature on corning glass and Si(100) substrates, with amount fluctuations of polyethylene glycol-300 in the solution. The transmittance of the films, for a fixed reaction time, increased up to ˜ 80% with the increase of % polyethylene glycol-300 in the solution, indicating the formation of very thin films due to the decrease of reaction rate with the increase of the concentration of polyethylene glycol-300. The optical band gaps were found to strongly rely on the composition of the bath deposition and increase with the increase of the polyethylene glycol-300 amount in the solution. Particle sizes between 2.8 and 8.7 nm were obtained by varying the % of polyethylene glycol-300 from 0.2 to 1.5. The concentration of polyethylene glycol-300 not only affects the reaction rate but also the morphology of the obtained films. PbS nanoparticles were found to be oriented preferentially along the < 200> plane. The absorption shifts towards short wavelength indicating a blue-shifting as a consequence of quantum confinement.

  3. 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.

  4. 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

    2013-12-02

    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.

  5. Both cross-links and monoadducts induced in DNA by psoralens can lead to sister chromatid exchange formation

    SciTech Connect

    Cortes, F. Facultad de Biologia, Sevilla ); Morgan, W.F.; Varcarcel, E.R.; Cleaver, J.E.; Wolff, S. )

    1991-09-01

    The relative importance of DNA-DNA cross-links and bulky monoadducts in sister chromatid exchange (SCE) formation was investigated in three human fibroblast cell lines with different repair capabilities. These cell lines included normal cells, which can repair both classes of lesion; xeroderma pigmentosum (XP) cells, which cannot repair either psoralen-induced cross-links or monoadducts; and an XP revertant that repairs only cross-links and not monoadducts. SCEs were induced by two psoralen derivatives. After activation with long-wave ultraviolet light, HMT produces cross-links and monoadducts in DNA, whereas 5-MIP produces only monoadducts. In normal human cells both psoralens induced SCEs, but if cells were allowed to repair for 18 h before bromodeoxyuridine (BrdUrd) was added for SCE analysis, the SCE frequency was significantly reduced. XP cells showed an SCE frequency that remained high regardless of whether SCEs were analyzed immediately after psoralen exposure of 18 h later. In the XP revertant that repairs only cross-links, both psoralens induced a high yield of SCEs when BrdUrd was added immediately after psoralen treatment. These observations indicate that both cross-links and monoadducts are lesions in DNA that can lead to SCE formation.

  6. 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.

  7. Non-parametric estimation of the odds ratios for continuous exposures using generalized additive models with an unknown link function.

    PubMed

    Cadarso-Suárez, Carmen; Roca-Pardiñas, Javier; Figueiras, Adolfo; González-Manteiga, Wenceslao

    2005-04-30

    The generalized additive, model (GAM) is a powerful and widely used tool that allows researchers to fit, non-parametrically, the effect of continuous predictors on a transformation of the mean response variable. Such a transformation is given by a so-called link function, and in GAMs this link function is assumed to be known. Nevertheless, if an incorrect choice is made for the link, the resulting GAM is misspecified and the results obtained may be misleading. In this paper, we propose a modified version of the local scoring algorithm that allows for the non-parametric estimation of the link function, by using local linear kernel smoothers. To better understand the effect that each covariate produces on the outcome, results are expressed in terms of the non-parametric odds ratio (OR) curves. Bootstrap techniques were used to correct the bias in the OR estimation and to construct point-wise confidence intervals. A simulation study was carried out to assess the behaviour of the resulting estimates. The proposed methodology was illustrated using data from the AIDS Register of Galicia (NW Spain), with a view to assessing the effect of the CD4 lymphocyte count on the probability of being AIDS-diagnosed via Tuberculosis (TB). This application shows how the link's flexibility makes it possible to obtain OR curve estimates that are less sensitive to the presence of outliers and unusual values that are often present in the extremes of the covariate distributions.

  8. 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.

  9. 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

  10. The Cretaceous OAE1a-Submarine Plateau Link: Additional Geochemical Evidence from Marine Sedimentary Sections

    NASA Astrophysics Data System (ADS)

    Duncan, R. A.; Tiraboschi, D.; Erba, E.; Walczak, P.; Clarke, L. J.

    2007-12-01

    We explore the proposed link between submarine plateau volcanism associated with construction of the Ontong Java-Manihiki-Hikurangi plateau (122 Ma) and early Aptian Ocean Anoxic Event 1a (OAE1a) through biostratigraphic data and trace metal abundance anomalies in marine sedimentary sections recovered in cores from DSDP Site 167 (Magellan Rise), ODP Sites 463 and 866 (Mid-Pacific Mountains), and at the Cismon and Piobbico on-land drillsites (Belluno and Umbria-Marche Basins, Italy). Sections were correlated using bio- and magneto-stratigraphic data, and the global d13C isotope anomaly associated with OAE1a. Bulk sediment samples that bracket the OAE1a interval at each site were analyzed by ICP-MS methods. After normalizing element concentrations to Zr to remove the variable contribution of terrigenous material to these sediments, we detected an interval of concentrated metal abundance anomalies that precedes the abrupt positive climb in the d13C isotope excursion, beginning near magnetic chron M0, continuing through the organic-rich interval of anoxic conditions. The metal abundance anomalies (e.g., Sc, Cu, Co, Sn, Cr, Ni, V, Cd, Ag, Bi, Se, W, Mo, Sb, Pb up to 100x background), variable in intensity and pattern of elements, indicate that intermittent hydrothermal activity, in the form of both water/rock exchange and magmatic degassing, introduced large concentrations of trace metals into the Cretaceous ocean at the same time that turnover in plankton communities and increases in isotopically light organic carbon burial occurred. The stratigraphic position of the intervals of trace metal anomalies matches events prior, during and after OAE1a and indicates that intermittent hydrothermal activity on a massive scale triggered abrupt changes in biota, carbon burial and deep ocean oxygen contents. Calcareous nannofossil abundance and composition display major changes in biogenic paleofluxes, temperature and fertility of surface waters, coeval with metal enrichments

  11. The Leading Edge of Early Childhood Education: Linking Science to Policy for a New Generation

    ERIC Educational Resources Information Center

    Lesaux, Nonie K., Ed.; Jones, Stephanie M., Ed.

    2016-01-01

    "The Leading Edge of Early Childhood Education" aims to support the effort to simultaneously scale up and improve the quality of early childhood education by bringing together relevant insights from emerging research to provide guidance for this critical, fledgling field. It reflects the growing recognition that early childhood…

  12. Reconstitution of peptidoglycan cross-linking leads to improved fluorescent probes of cell wall synthesis.

    PubMed

    Lebar, Matthew D; May, Janine M; Meeske, Alexander J; Leiman, Sara A; Lupoli, Tania J; Tsukamoto, Hirokazu; Losick, Richard; Rudner, David Z; Walker, Suzanne; Kahne, Daniel

    2014-08-06

    The peptidoglycan precursor, Lipid II, produced in the model Gram-positive bacterium Bacillus subtilis differs from Lipid II found in Gram-negative bacteria such as Escherichia coli by a single amidation on the peptide side chain. How this difference affects the cross-linking activity of penicillin-binding proteins (PBPs) that assemble peptidoglycan in cells has not been investigated because B. subtilis Lipid II was not previously available. Here we report the synthesis of B. subtilis Lipid II and its use by purified B. subtilis PBP1 and E. coli PBP1A. While enzymes from both organisms assembled B. subtilis Lipid II into glycan strands, only the B. subtilis enzyme cross-linked the strands. Furthermore, B. subtilis PBP1 catalyzed the exchange of both D-amino acids and D-amino carboxamides into nascent peptidoglycan, but the E. coli enzyme only exchanged D-amino acids. We exploited these observations to design a fluorescent D-amino carboxamide probe to label B. subtilis PG in vivo and found that this probe labels the cell wall dramatically better than existing reagents.

  13. Encapsulation of lead from hazardous CRT glass wastes using biopolymer cross-linked concrete systems

    SciTech Connect

    Kim, Daeik; Quinlan, Michael; Yen, Teh Fu

    2009-01-15

    Discarded computer monitors and television sets are identified as hazardous materials due to the high content of lead in their cathode ray tubes (CRTs). Over 98% of lead is found in CRT glass. More than 75% of obsolete electronics including TV and CRT monitors are in storage because appropriate e-waste management and remediation technologies are insufficient. Already an e-waste tsunami is starting to roll across the US and the whole world. Thus, a new technology was developed as an alternative to current disposal methods; this method uses a concrete composite crosslinked with minute amounts of biopolymers and a crosslinking agent. Commercially available microbial biopolymers of xanthan gum and guar gum were used to encapsulate CRT wastes, reducing Pb leachability as measured by standard USEPA methods. In this investigation, the synergistic effect of the crosslinking reaction was observed through blending two different biopolymers or adding a crosslinking agent in biopolymer solution. This CRT-biopolymer-concrete (CBC) composite showed higher compressive strength than the standard concrete and a considerable decrease in lead leachability.

  14. Encapsulation of lead from hazardous CRT glass wastes using biopolymer cross-linked concrete systems.

    PubMed

    Kim, Daeik; Quinlan, Michael; Yen, Teh Fu

    2009-01-01

    Discarded computer monitors and television sets are identified as hazardous materials due to the high content of lead in their cathode ray tubes (CRTs). Over 98% of lead is found in CRT glass. More than 75% of obsolete electronics including TV and CRT monitors are in storage because appropriate e-waste management and remediation technologies are insufficient. Already an e-waste tsunami is starting to roll across the US and the whole world. Thus, a new technology was developed as an alternative to current disposal methods; this method uses a concrete composite crosslinked with minute amounts of biopolymers and a crosslinking agent. Commercially available microbial biopolymers of xanthan gum and guar gum were used to encapsulate CRT wastes, reducing Pb leachability as measured by standard USEPA methods. In this investigation, the synergistic effect of the crosslinking reaction was observed through blending two different biopolymers or adding a crosslinking agent in biopolymer solution. This CRT-biopolymer-concrete (CBC) composite showed higher compressive strength than the standard concrete and a considerable decrease in lead leachability.

  15. 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.

  16. 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.

  17. Mitochondrial dysfunction leads to nuclear genome instability: A link through iron-sulfur clusters

    PubMed Central

    Veatch, Joshua R.; McMurray, Michael A.; Nelson, Zara W.; Gottschling, Daniel E.

    2009-01-01

    Summary Mutations and deletions in the mitochondrial genome (mtDNA), as well as instability of the nuclear genome, are involved in multiple human diseases. Here we report that in Saccharomyces cerevisiae, loss of mtDNA leads to nuclear genome instability, through a process of cell cycle arrest and selection we define as a cellular crisis. This crisis is not mediated by the absence of respiration, but instead correlates with a reduction in the mitochondrial membrane potential. Analysis of cells undergoing this crisis identified a defect in iron-sulfur cluster (ISC) biogenesis, which requires normal mitochondrial function. We found that down-regulation of non-mitochondrial ISC protein biogenesis was sufficient to cause increased genomic instability in cells with intact mitochondrial function. These results suggest mitochondrial dysfunction stimulates nuclear genome instability by inhibiting the production of ISC-containing protein(s), which are required for maintenance of nuclear genome integrity. PMID:19563757

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Identification of lead small molecule inhibitors of glycogen synthase kinase-3 beta using a fragment-linking strategy.

    PubMed

    Kim, Jinhee; Moon, Yonghoon; Hong, Sungwoo

    2016-12-01

    Glycogen synthase kinase-3 beta (GSK3β) kinase serves as a promising therapeutic target for the treatment of various human diseases, such as diabetes, obesity, and Alzheimer's disease. In this study, we report lead GSK3β inhibitors identified using a fragment-linking strategy. Through the systematic exploration, a six-atom chain unit bearing the rigid double bond was found to be a suitable linker connecting two fragments, which enables favorable contacts with backbone groups of residues in the pockets. As a consequence, potent GSK3β inhibitor 9i was found with IC50 values of 19nM. The binding mode analysis indicates that the activities of the inhibitors appear to be achieved by the establishment of multiple hydrogen bonds and hydrophobic interactions in the ATP-binding site of GSK3β. The good biochemical potencies and structural uniqueness of the inhibitors support consideration in the further study to optimize the biological activity.

  4. Unidata Workshop: Demonstrating Democratization of Numerical Weather Prediction Capabilities Using Linked Environments for Atmospheric Discovery (LEAD) Capabilities

    NASA Astrophysics Data System (ADS)

    Baltzer, T.; Wilson, A.; Marru, S.; Rossi, A.; Christi, M.; Hampton, S.; Gannon, D.; Alameda, J.; Ramamurthy, M.; Droegemeier, K.

    2006-12-01

    On July 13th 2006 during the triannual Unidata Workshop, members of the Unidata community got their first experience with capabilities being developed under the Linked Environments for Atmospheric Discovery (LEAD) project (see: http://lead.ou.edu). The key LEAD goal demonstrated during the workshop was that of "Democratization," that is, providing capabilities that typically have a high barrier to entry to the larger meteorological community. At the workshop, participants worked with software that demonstrated the specific concepts of: 1) Lowering the barrier to entry by making it easy for users to: - Experiment using meteorological tools - Create meteorological forecasts - Perform mesoscale modeling and forecasting - Access data (source and product) - Make use of large scale cyberinfrastructure (E.g. TeraGrid) 2) Giving users the freedom from technological issues such as: - Hassle-free access to supercomputing resources - Hassle-free execution of forecast models and related tools - Data format independence This talk will overview the capabilities presented to the Unidata workshop participants as well as capabilities developed since the workshop. There will also be a lessons-learned section. This overview will be accomplished with a live demonstration of some of the capabilities. Capabilities that will be discussed and demonstrated have applicability across many disciplines e.g. discovering, acquiring and using data and orchestrating of complex workflow. Acknowledgement: The LEAD project involves the work of nearly 100 individuals whose dedication has resulted in the capabilities that will be shown here. The authors would like to recognize all of them, but in particular we'd like to recognize: John Caron, Rich Clark, Ethan Davis, Charles Hart, Yuan Ho, Scott Jenson, Rob Kambic, Brian Kelly, Ning Liu, Jeff McWhirter, Don Murray, Beth Plale, Rahul Ramachandran, Yogesh Simmhan, Kevin Thomas, Nithya Vijayakumar, Yunheng Wang, Dan Weber, and Bob Wilhelmson.

  5. 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.

  6. 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.

  7. 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

  8. [Analysis of lead in unknown samples based on the standard addition method using laser induced breakdown spectroscopy].

    PubMed

    Fang, Li; Zhao, Nan-jing; Meng, De-shuo; Yuan, Jing; Tang, Jie; Wang, Yin; Yu, Yang; Ma, Ming-jun; Hu, Li; Zhang, Da-hai; Xiao, Xue; Wang, Yu; Liu, Jian-guo; Liu, Wen-qing

    2015-01-01

    The standard addition method with laser induced breakdown spectroscopy was used to analyze an unknown sample taken from a lead battery factory. the matrix influence on the results was effectively avoided when the external or internal standard method was used, and the pretreatment of samples was simple and quick. The Nd ' YAG pulse laser with wavelength 1 064 nm was used as the excitation source. The echelle spectroscopy with high resolution and wide spectral range was used as the spectral separation device, and the intensified charge coupled device (ICCD) as the spectral detection device in the experiment. The characteristic line at 405. 78 nrn was chosen as the analysis line to measure Pb concentration. Fe I : 404. 58 line was chosen as the internal standard. Pre-experiment was carried out to confirm the appropriate condition. Under the laser energy of 128. 5 mJ, the delay time of 2. 5 tps, and the gate width of 3 ps, it was determined that with the addition of Pb to the sample in the range of 0 and 25 000 mg . kg-1, there wasn't self-absorption. There was a good linear relationship between the intensity of the spectral line of 405. 78 nm and the addition of Pb. The appropriate concentration of Pb added into the sample for analysis was determined by this series of samples. On this basis, four samples were prepared with three parallel samples for each sample in order to verify the repeatability and reliability of the method, i. e. 5 000, 10 000, 15 000, 20 000 mg . kg-1 Pb was added into the original sample. The results were compared with the result of ICP-MS. The twelve samples' relative errors were between -24. 6% and 17. 6%. The average result was 43 069 mg . kg-1 with the relative error -2. 44%.

  9. 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.

  10. 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.

  11. 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.

  12. 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%.

  13. 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.

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

    SciTech Connect

    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

    2016-05-04

    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%.

  15. Linked Environment for Atmospheric Discovery (LEAD): Transforming the Sensing and Numerical Prediction of High Impact Local Weather Through Dynamic Adaptation

    NASA Astrophysics Data System (ADS)

    Ramamurthy, M.; Droegemeier, K.

    2006-12-01

    Those who have experienced the devastation of a tornado, the raging waters of a flash flood, or the paralyzing impacts of lake-effect snows understand that mesoscale weather develops rapidly, often with considerable uncertainty with regard to location. Such weather is also locally intense and frequently influenced by processes on both larger and smaller scales. Ironically, few of the technologies used to observe the atmosphere, predict its evolution, and compute, transmit, or store information about it operate in a manner that accommodates the dynamic behavior of mesoscale weather. Radars do not adaptively scan specific regions of thunderstorms; numerical models are run largely on fixed time schedules in fixed configurations; and cyberinfrastructure does not allow meteorological tools to run on-demand, change configurations in response to the weather, or provide the fault tolerance needed for rapid reconfiguration. As a result, today's weather technology is highly constrained and far from optimal when applied to any particular situation. This presentation describes a major paradigm shift now underway in the field of meteorology -- away from today's environment in which remote sensing systems, atmospheric prediction models, and hazardous weather detection systems operate in fixed configurations, and on fixed schedules largely independent of weather -- to one in which they can change their configuration dynamically in response to the evolving weather. A major driver of this change is a project known as Linked Environments for Atmospheric Discovery (LEAD) -- a 5-year NSF Large Information Technology Research (ITR) grant that is developing cyberinfrastructure to allow scientists, students, tools and sensors to interact with weather. This presentation will describe the research and technology development being performed to establish this capability

  16. A competitive indirect enzyme-linked immunoassay for lead ion measurement using mAbs against the lead-DTPA complex.

    PubMed

    Xiang, Jun-jian; Zhai, Yi-fan; Tang, Yong; Wang, Hong; Liu, Bin; Guo, Chang-wei

    2010-05-01

    Immunoassays for quantitative measurement of environmental heavy metals offer several advantages over other traditional methods. To develop an immunoassay for lead, Balb/c mice were immunized with a lead-chelate-protein conjugate to allow maximum exposure of the metal to the immune system. Three stable hybridoma cell lines were obtained through spleen cells fusion with Sp2/0 cells. One cell line, 2A11D11, produced mAbs with preferential selectivity and sensitivity for Pb-DTPA than DTPA, exhibiting an affinity constant of 3.34 + or - 0.24 x 10(9) M(-1). Cross reactivity (CR) with other metals were below 1%, except for Fe(III) with a CR less than 5%. This quantitative indirect ELISA for the lead ion was used to detect environmental lead content in local water sources; importantly, the results from the immunoassay were in excellent agreement with those from ICP-MS. Development of immunoassays for metal ions may thus facilitate the detection and regulation of environmental pollution.

  17. 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

  18. 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…

  19. 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.

  20. Strategic addition of an N-linked glycan to a monoclonal antibody improves its HIV-1-neutralizing activity.

    PubMed

    Song, Ruijiang; Oren, Deena A; Franco, David; Seaman, Michael S; Ho, David D

    2013-11-01

    Ibalizumab is a humanized monoclonal antibody that binds human CD4--a key receptor for HIV--and blocks HIV-1 infection. However, HIV-1 strains with mutations resulting in loss of an N-linked glycan from the V5 loop of the envelope glycoprotein gp120 are resistant to ibalizumab. Previous structural analysis suggests that this glycan fills a void between the gp120 V5 loop and the ibalizumab light chain, perhaps causing steric hindrance that disrupts viral entry. If this void contributes to HIV-1 resistance to ibalizumab, we reasoned that 'refilling' it by engineering an N-linked glycan into the ibalizumab light chain at a position spatially proximal to gp120 V5 may restore susceptibility to ibalizumab. Indeed, one such ibalizumab variant neutralized 100% of 118 diverse HIV-1 strains tested in vitro, including 10 strains resistant to parental ibalizumab. These findings demonstrate that the strategic placement of a glycan in the variable region of a monoclonal antibody can substantially enhance its activity.

  1. Strategic addition of an N-linked glycan to a monoclonal antibody improves its HIV-1-neutralizing activity

    PubMed Central

    Song, Ruijiang; Oren, Deena A.; Franco, David; Seaman, Michael S.; Ho, David D.

    2013-01-01

    Ibalizumab is a humanized monoclonal antibody that binds human CD4—a key receptor for HIV—and blocks HIV-1 infection. However, HIV-1 strains with mutations resulting in loss of an N-linked glycan from the V5 loop of the envelope protein gp120 are resistant to ibalizumab. Previous structural analysis suggests that this glycan fills a void between the gp120 V5 loop and the ibalizumab L chain, perhaps causing steric hindrance that disrupts viral entry. If this void contributes to HIV-1 resistance to ibalizumab, we reasoned that ‘refilling’ it by engineering an N-linked glycan into the ibalizumab L chain at a position spatially proximal to gp120 V5 may restore susceptibility to ibalizumab. Indeed, one such ibalizumab variant neutralized 100% of 118 tested diverse HIV-1 strains in vitro, including ten strains resistant to parental ibalizumab. These findings demonstrate that the strategic placement of a glycan in the variable region of a monoclonal antibody can substantially enhance its activity. PMID:24097413

  2. Increasing the maximum achievable strain of a covalent polymer gel through the addition of mechanically invisible cross-links.

    PubMed

    Kean, Zachary S; Hawk, Jennifer L; Lin, Shaoting; Zhao, Xuanhe; Sijbesma, Rint P; Craig, Stephen L

    2014-09-10

    Hydrogels and organogels made from polymer networks are widely used in biomedical applications and soft, active devices for which the ability to sustain large deformations is required. The strain at which polymer networks fracture is typically improved through the addition of elements that dissipate energy, but these materials require extra work to achieve a given, desired level of deformation. Here, the addition of mechanically "invisible" supramolecular crosslinks causes substantial increases in the ultimate gel properties without incurring the added energetic costs of dissipation.

  3. Copy number gain of VCX, X-linked multi-copy gene, leads to cell proliferation and apoptosis during spermatogenesis

    PubMed Central

    Huang, Zhenyao; Zhang, Yan; Zhou, Ran; Song, Ling; Ling, Xiufeng; Hu, Zhibin; Miao, Dengshun; Shen, Hongbing; Xia, Yankai; Wang, Xinru; Lu, Chuncheng

    2016-01-01

    Male factor infertility affects one-sixth of couples worldwide, and non-obstructive azoospermia (NOA) is one of the most severe forms. In recent years there has been increasing evidence to implicate the participation of X chromosome in the process of spermatogenesis. To uncover the roles of X-linked multi-copy genes in spermatogenesis, we performed systematic analysis of X-linked gene copy number variations (CNVs) and Y chromosome haplogrouping in 447 idiopathic NOA patients and 485 healthy controls. Interestingly, the frequency of individuals with abnormal level copy of Variable charge, X-linked (VCX) was significantly different between cases and controls after multiple test correction (p = 5.10 × 10−5). To discriminate the effect of gain/loss copies in these genes, we analyzed the frequency of X-linked multi-copy genes in subjects among subdivided groups. Our results demonstrated that individuals with increased copy numbers of Nuclear RNA export factor 2 (NXF2) (p = 9.21 × 10−8) and VCX (p = 1.97 × 10−4) conferred the risk of NOA. In vitro analysis demonstrated that increasing copy number of VCX could upregulate the gene expression and regulate cell proliferation and apoptosis. Our study establishes a robust association between the VCX CNVs and NOA risk. PMID:27705943

  4. Phosphofructo-1-Kinase Deficiency Leads to a Severe Cardiac and Hematological Disorder in Addition to Skeletal Muscle Glycogenosis

    PubMed Central

    García, Miguel; Pujol, Anna; Ruzo, Albert; Riu, Efrén; Ruberte, Jesús; Arbós, Anna; Serafín, Anna; Albella, Beatriz; Felíu, Juan Emilio; Bosch, Fátima

    2009-01-01

    Mutations in the gene for muscle phosphofructo-1-kinase (PFKM), a key regulatory enzyme of glycolysis, cause Type VII glycogen storage disease (GSDVII). Clinical manifestations of the disease span from the severe infantile form, leading to death during childhood, to the classical form, which presents mainly with exercise intolerance. PFKM deficiency is considered as a skeletal muscle glycogenosis, but the relative contribution of altered glucose metabolism in other tissues to the pathogenesis of the disease is not fully understood. To elucidate this issue, we have generated mice deficient for PFKM (Pfkm−/−). Here, we show that Pfkm−/− mice had high lethality around weaning and reduced lifespan, because of the metabolic alterations. In skeletal muscle, including respiratory muscles, the lack of PFK activity blocked glycolysis and resulted in considerable glycogen storage and low ATP content. Although erythrocytes of Pfkm−/− mice preserved 50% of PFK activity, they showed strong reduction of 2,3-biphosphoglycerate concentrations and hemolysis, which was associated with compensatory reticulocytosis and splenomegaly. As a consequence of these haematological alterations, and of reduced PFK activity in the heart, Pfkm−/− mice developed cardiac hypertrophy with age. Taken together, these alterations resulted in muscle hypoxia and hypervascularization, impaired oxidative metabolism, fiber necrosis, and exercise intolerance. These results indicate that, in GSDVII, marked alterations in muscle bioenergetics and erythrocyte metabolism interact to produce a complex systemic disorder. Therefore, GSDVII is not simply a muscle glycogenosis, and Pfkm−/− mice constitute a unique model of GSDVII which may be useful for the design and assessment of new therapies. PMID:19696889

  5. Leptin as a link between the immune system and kidney-related diseases: leading actor or just a coadjuvant?

    PubMed

    Moraes-Vieira, P M M; Bassi, E J; Araujo, R C; Câmara, N O S

    2012-08-01

    Food intake and nutritional status modify the physiological responses of the immune system to illness and infection and regulate the development of chronic inflammatory processes, such as kidney disease. Adipose tissue secretes immune-related proteins called adipokines that have pleiotropic effects on both the immune and neuroendocrine systems, linking metabolism and immune physiology. Leptin, an adipose tissue-derived adipokine, displays a variety of immune and physiological functions, and participates in several immune responses. Here, we review the current literature on the role of leptin in kidney diseases, linking adipose tissue and the immune system with kidney-related disorders. The modulation of this adipose hormone may have a major impact on the treatment of several immune- and metabolic-related kidney diseases.

  6. Linking traumatic brain injury to chronic traumatic encephalopathy: identification of potential mechanisms leading to neurofibrillary tangle development.

    PubMed

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

    2014-07-01

    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.

  7. 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.

  8. 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

  9. 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.

  10. Knockdown of αII spectrin in normal human cells by siRNA leads to chromosomal instability and decreased DNA interstrand cross-link repair

    PubMed Central

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

    2009-01-01

    Nonerythroid α-spectrin (αIISp) 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 αIISp plays in normal human cells and in the repair defect in FA, αIISp was knocked down in normal cells using siRNA. Depletion of αIISp 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 αIISp and XPF nuclear foci. Thus depletion of αIISp in normal cells leads to a number of defects observed in FA cells, such as chromosome instability and a deficiency in cross-link repair. PMID:19217883

  11. Investigation of cross-linked and additive containing polymer materials for membranes with improved performance in pervaporation and gas separation.

    PubMed

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

    2012-10-22

    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.

  12. 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

  13. 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.

  14. 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.

  15. Autosomal and X-Linked Additive Genetic Variation for Lifespan and Aging: Comparisons Within and Between the Sexes in Drosophila melanogaster.

    PubMed

    Griffin, Robert M; Schielzeth, Holger; Friberg, Urban

    2016-12-07

    Theory makes several predictions concerning differences in genetic variation between the X chromosome and the autosomes due to male X hemizygosity. The X chromosome should: (i) typically show relatively less standing genetic variation than the autosomes, (ii) exhibit more variation in males compared to females because of dosage compensation, and (iii) potentially be enriched with sex-specific genetic variation. Here, we address each of these predictions for lifespan and aging in Drosophila melanogaster To achieve unbiased estimates of X and autosomal additive genetic variance, we use 80 chromosome substitution lines; 40 for the X chromosome and 40 combining the two major autosomes, which we assay for sex-specific and cross-sex genetic (co)variation. We find significant X and autosomal additive genetic variance for both traits in both sexes (with reservation for X-linked variation of aging in females), but no conclusive evidence for depletion of X-linked variation (measured through females). Males display more X-linked variation for lifespan than females, but it is unclear if this is due to dosage compensation since also autosomal variation is larger in males. Finally, our results suggest that the X chromosome is enriched for sex-specific genetic variation in lifespan but results were less conclusive for aging overall. Collectively, these results suggest that the X chromosome has reduced capacity to respond to sexually concordant selection on lifespan from standing genetic variation, while its ability to respond to sexually antagonistic selection may be augmented.

  16. Autosomal and X-Linked Additive Genetic Variation for Lifespan and Aging: Comparisons Within and Between the Sexes in Drosophila melanogaster

    PubMed Central

    Griffin, Robert M.; Schielzeth, Holger; Friberg, Urban

    2016-01-01

    Theory makes several predictions concerning differences in genetic variation between the X chromosome and the autosomes due to male X hemizygosity. The X chromosome should: (i) typically show relatively less standing genetic variation than the autosomes, (ii) exhibit more variation in males compared to females because of dosage compensation, and (iii) potentially be enriched with sex-specific genetic variation. Here, we address each of these predictions for lifespan and aging in Drosophila melanogaster. To achieve unbiased estimates of X and autosomal additive genetic variance, we use 80 chromosome substitution lines; 40 for the X chromosome and 40 combining the two major autosomes, which we assay for sex-specific and cross-sex genetic (co)variation. We find significant X and autosomal additive genetic variance for both traits in both sexes (with reservation for X-linked variation of aging in females), but no conclusive evidence for depletion of X-linked variation (measured through females). Males display more X-linked variation for lifespan than females, but it is unclear if this is due to dosage compensation since also autosomal variation is larger in males. Finally, our results suggest that the X chromosome is enriched for sex-specific genetic variation in lifespan but results were less conclusive for aging overall. Collectively, these results suggest that the X chromosome has reduced capacity to respond to sexually concordant selection on lifespan from standing genetic variation, while its ability to respond to sexually antagonistic selection may be augmented. PMID:27678519

  17. 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

  18. 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

    2016-06-01

    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

  19. Beneficial effects of activated carbon additives on the performance of negative lead-acid battery electrode for high-rate partial-state-of-charge operation

    NASA Astrophysics Data System (ADS)

    Xiang, Jiayuan; Ding, Ping; Zhang, Hao; Wu, Xianzhang; Chen, Jian; Yang, Yusheng

    2013-11-01

    Experiments are made with negative electrode of 2 V cell and 12 V lead-acid battery doped with typical activated carbon additives. It turns out that the negative electrode containing tens-of-micron-sized carbon particles in NAM exhibits markedly increased HRPSoC cycle life than the one containing carbon particles with much smaller size of several microns or the one containing no activated carbon. The improved performance is mainly attributed to the optimized NAM microstructure and the enhanced electrode reaction kinetics by introducing appropriate activated carbon. The beneficial effects can be briefly summarized from three aspects. First, activated carbon acts as new porous-skeleton builder to increase the porosity and active surface of NAM, and thus facilitates the electrolyte diffusion from surface to inner and provides more sites for crystallization/dissolution of lead sulfate; second, activated carbon plays the role of electrolyte supplier to provide sufficient H2SO4 in the inner of plate when the diffusion of H2SO4 from plate surface cannot keep pace of the electrode reaction; Third, activated carbon acts as capacitive buffer to absorb excess charge current which would otherwise lead to insufficient NAM conversion and hydrogen evolution.

  20. Unprecedented chemical reactivity of a paramagnetic endohedral metallofullerene La@C(s)-C82 that leads hydrogen addition in the 1,3-dipolar cycloaddition reaction.

    PubMed

    Takano, Yuta; Slanina, Zdenek; Mateos, Jaime; Tsuchiya, Takayoshi; Kurihara, Hiroki; Uhlik, Filip; Herranz, María Ángeles; Martín, Nazario; Nagase, Shigeru; Akasaka, Takeshi

    2014-12-17

    Synthesizing unprecedented diamagnetic adducts of an endohedral metallofullerene was achieved by using 1,3-dipolar cycloaddition reaction of paramagnetic La@C(s)-C82 with a simultaneous hydrogen addition. The selective formation of two main products, La@C(s)-C82HCMe2NMeCHPh (2a and 2b), was first detected by HPLC analysis and MALDI-TOF mass spectrometry. 2a and 2b-O, which was readily formed by the oxidation of 2b, were isolated by multistep HPLC separation and were fully characterized by spectroscopic methods, including 1D and 2D-NMR, UV-vis-NIR measurements and electrochemistry. The hydrogen atom was found to be connected to the fullerene cage directly in the case of 2a, and the redox behavior indicated that the C-H bond can still be readily oxidized. The reaction mechanism and the molecular structures of 2a and 2b were reasonably proposed by the interplay between experimental observations and DFT calculations. The feasible order of the reaction process would involve a 1,3-dipolar cycloaddition followed by the hydrogen addition through a radical pathway. It is concluded that the characteristic electronic properties and molecular structure of La@C(s)-C82 resulted in a site-selective reaction, which afforded a unique chemical derivative of an endohedral metallofullerene in high yields. Derivative 2a constitutes the first endohedral metallofullerene where the direct linking of a hydrogen atom has been structurally proven.

  1. Link direction for link prediction

    NASA Astrophysics Data System (ADS)

    Shang, Ke-ke; Small, Michael; Yan, Wei-sheng

    2017-03-01

    Almost all previous studies on link prediction have focused on using the properties of the network to predict the existence of links between pairs of nodes. Unfortunately, previous methods rarely consider the role of link direction for link prediction. In fact, many real-world complex networks are directed and ignoring the link direction will mean overlooking important information. In this study, we propose a phase-dynamic algorithm of the directed network nodes to analyse the role of link directions and demonstrate that the bi-directional links and the one-directional links have different roles in link prediction and network structure formation. From this, we propose new directional prediction methods and use six real networks to test our algorithms. In real networks, we find that compared to a pair of nodes which are connected by a one-directional link, a pair of nodes which are connected by a bi-directional link always have higher probabilities to connect to the common neighbours with only bi-directional links (or conversely by one-directional links). We suggest that, in the real networks, the bi-directional links will generally be more informative for link prediction and network structure formation. In addition, we propose a new directional randomized algorithm to demonstrate that the direction of the links plays a significant role in link prediction and network structure formation.

  2. 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.

  3. 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.

  4. The additionally glycosylated variant of human sex hormone-binding globulin (SHBG) is linked to estrogen-dependence of breast cancer.

    PubMed

    Becchis, M; Frairia, R; Ferrera, P; Fazzari, A; Ondei, S; Alfarano, A; Coluccia, C; Biglia, N; Sismondi, P; Fortunati, N

    1999-03-01

    Sex Hormone-Binding Globulin (SHBG), the plasma carrier for androgens and estradiol, inhibits the estradiol-induced proliferation of breast cancer cells through its membrane receptor, cAMP, and PKA. In addition, the SHBG membrane receptor is preferentially expressed in estrogen-dependent (ER+/PR+) breast cancers which are also characterized by a lower proliferative rate than tumors negative for the SHBG receptor. A variant SHBG with a point mutation in exon 8, causing an aminoacid substitution (Asp 327-->Asn) and thus, the introduction of an additional N-glycosylation site, has been reported. In this work, the distribution of the SHBG variant was studied in 255 breast cancer patients, 32 benign mammary disease patients, and 120 healthy women. The presence of the SHBG mutation was evaluated with PCR amplification of SHBG exon 8 and Hinf I restriction fragment length polymorphism (RFLP) procedure. This technique allowed us to identify 54 SHBG variants (53 W/v and 1 v/v) in breast cancer patients (21.2%), 5 variants (4 W/v and 1 v/v) in benign mammary disease patients (15.6%), and 14 variants (W/v) in the control group (11.6%). The results of PCR and RFLP were confirmed both by nucleotide sequence of SHBG exon 8 and western blot of the plasma SHBG. No differences in the mean plasma level of the protein were observed in the three populations. The frequency of the SHBG variant was significantly higher in ER+/PR+ tumors and in tumors diagnosed in patients over 50 years of age than in the control group. This observation suggests the existence of a close link between the estrogen-dependence of breast cancer and the additionally glycosylated SHBG, further supporting a critical role of the protein in the neoplasm.

  5. A mutation in X-linked inhibitor of apoptosis (G466X) leads to memory inflation of Epstein-Barr virus-specific T cells.

    PubMed

    Lopez-Granados, E; Stacey, M; Kienzler, A-K; Sierro, S; Willberg, C B; Fox, C P; Rigaud, S; Long, H M; Hislop, A D; Rickinson, A B; Patel, S; Latour, S; Klenerman, P; Chapel, H

    2014-12-01

    Mutations in the X-linked inhibitor of apoptosis (XIAP) gene have been associated with XLP-like disease, including recurrent Epstein-Barr virus (EBV)-related haemophagocytic lymphohystiocytosis (HLH), but the immunopathogenic bases of EBV-related disease in XIAP deficiency is unknown. We present the first analysis of EBV-specific T cell responses in functional XIAP deficiency. In a family of patients with a novel mutation in XIAP (G466X) leading to a late-truncated protein and varying clinical features, we identified gradual hypogammaglobulinaemia and large expansions of T cell subsets, including a prominent CD4(+) CD8(+) population. Extensive ex-vivo analyses showed that the expanded T cell subsets were dominated by EBV-specific cells with conserved cytotoxic, proliferative and interferon (IFN)-γ secretion capacity. The EBV load in blood fluctuated and was occasionally very high, indicating that the XIAP(G466X) mutation could impact upon EBV latency. XIAP deficiency may unravel a new immunopathogenic mechanism in EBV-associated disease.

  6. Alzheimer's disease (AD)-like pathology in aged monkeys after infantile exposure to environmental metal lead (Pb): evidence for a developmental origin and environmental link for AD.

    PubMed

    Wu, Jinfang; Basha, Md Riyaz; Brock, Brian; Cox, David P; Cardozo-Pelaez, Fernando; McPherson, Christopher A; Harry, Jean; Rice, Deborah C; Maloney, Bryan; Chen, Demao; Lahiri, Debomoy K; Zawia, Nasser H

    2008-01-02

    The sporadic nature of Alzheimer's disease (AD) argues for an environmental link that may drive AD pathogenesis; however, the triggering factors and the period of their action are unknown. Recent studies in rodents have shown that exposure to lead (Pb) during brain development predetermined the expression and regulation of the amyloid precursor protein (APP) and its amyloidogenic beta-amyloid (Abeta) product in old age. Here, we report that the expression of AD-related genes [APP, BACE1 (beta-site APP cleaving enzyme 1)] as well as their transcriptional regulator (Sp1) were elevated in aged (23-year-old) monkeys exposed to Pb as infants. Furthermore, developmental exposure to Pb altered the levels, characteristics, and intracellular distribution of Abeta staining and amyloid plaques in the frontal association cortex. These latent effects were accompanied by a decrease in DNA methyltransferase activity and higher levels of oxidative damage to DNA, indicating that epigenetic imprinting in early life influenced the expression of AD-related genes and promoted DNA damage and pathogenesis. These data suggest that AD pathogenesis is influenced by early life exposures and argue for both an environmental trigger and a developmental origin of AD.

  7. The testing of batteries linked to supercapacitors with electrochemical impedance spectroscopy: A comparison between Li-ion and valve regulated lead acid batteries

    NASA Astrophysics Data System (ADS)

    Ferg, Ernst; Rossouw, Claire; Loyson, Peter

    2013-03-01

    For electric vehicles, a supercapacitor can be coupled to the electrical system in order to increase and optimize the energy and power densities of the drive system during acceleration and regenerative breaking. This study looked at the charge acceptance and maximum discharge ability of a valve regulated lead acid (VRLA) and a Li-ion battery connected in parallel to supercapacitors. The test procedure evaluated the advantage of using a supercapacitor at a 2 F:1 Ah ratio with the battery types at various states of charge (SoC). The results showed that about 7% of extra charge was achieved over a 5-s test time for a Li-ion hybrid system at 20% SoC, whereas at the 80% SoC the additional capacity was approximately 16%. While for the VRLA battery hybrid system, an additional charge of up to 20% was achieved when the battery was at 80% SoC, with little or no benefit at the 20% SoC. The advantage of the supercapacitor in parallel with a VRLA battery was noticeable on its discharge ability, where significant extra capacity was achieved for short periods of time for a battery at the 60% and 40% SoC when compared to the Li-ion hybrid system. The study also made use of Electrochemical Impedance Spectroscopy (EIS) with a suitable equivalent circuit model to explain, in particular, the internal resistance and capacitance differences observed between the different battery chemistries with and without a supercapacitor.

  8. 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.

  9. 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.

  10. Role of Additives in Minimizing Zinc Electrode Shape Change: The Effect of Lead on the Kinetics of Zn(II) Reduction in Concentrated Alkaline Media.

    DTIC Science & Technology

    1985-07-01

    Stripping of either the alloy phase or the underpotential deposit is believed to give rise to the additional oxidation peaks observed at -1.15V and...multiple oxidation peaks in the region from -0.40V to -0.80 volts correspond to the oxidation of both bulk and underpotentially deposited (UPD) Pb on silver...shifts in zinc underpotential deposition are also seen in the presence of Bi203, whose solubility is only 60 ppm. Yet, In20 3 additive, whose solubility

  11. Cis-transcriptional variation in maize inbred lines B73 and Mo17 leads to additive expression patterns in the F1 hybrid.

    PubMed

    Stupar, Robert M; Springer, Nathan M

    2006-08-01

    Microarray analysis of gene expression patterns in immature ear, seedling, and embryo tissues from the maize inbred lines B73 and Mo17 identified numerous genes with variable expression. Some genes had detectable expression in only one of the two inbreds; most of these genes were detected in the genomic DNA of both inbreds, indicating that the expression differences are likely caused by differential regulation rather than by differences in gene content. Gene expression was also monitored in the reciprocal F1 hybrids B73xMo17 and Mo17xB73. The reciprocal F1 hybrid lines did not display parental effects on gene expression levels. Approximately 80% of the differentially expressed genes displayed additive expression patterns in the hybrids relative to the inbred parents. The approximately 20% of genes that display nonadditive expression patterns tend to be expressed at levels within the parental range, with minimal evidence for novel expression levels greater than the high parent or less than the low parent. Analysis of allele-specific expression patterns in the hybrid suggested that intraspecific variation in gene expression levels is largely attributable to cis-regulatory variation in maize. Collectively, our data suggest that allelic cis-regulatory variation between B73 and Mo17 dictates maintenance of inbred allelic expression levels in the F1 hybrid, resulting in additive expression patterns.

  12. Addition of Montelukast to Low-Dose Inhaled Corticosteroid Leads to Fewer Exacerbations in Older Patients Than Medium-Dose Inhaled Corticosteroid Monotherapy

    PubMed Central

    Ye, Young-Min; Kim, Sang-Ha; Hur, Gyu-Young; Kim, Joo-Hee; Park, Jung-Won; Shim, Jae Jeong; Jung, Ki-Suck; Lee, Hyun-Young

    2015-01-01

    Purpose There have been few reports regarding the efficacy of antiasthmatics in older patients. To compare the efficacy of the addition of montelukast to low-dose inhaled budesonide (MON-400BUD) versus increasing the dose of inhaled steroid (800BUD) on asthma control in older asthmatics. Methods A randomized, open-label, parallel-designed trial was conducted for 12 weeks. The primary endpoint was the rate of patients who reached "well-controlled asthma status" after the 12-week treatment period. Additionally, asthma exacerbations, sputum inflammatory cells, asthma control test (ACT) and physical functioning scale (PFS), and adverse reactions were monitored. Results Twenty-four (36.9%) and 22 (34.9%) subjects in the MON-400BUD (n=65) and 800BUD (n=63) groups had well-controlled asthma at the end of the study, respectively. The numbers of asthma exacerbations requiring oral corticosteroid treatment (20 vs 9, respectively, P=0.036) and the development of sore throat (22 vs 11, respectively, P=0.045) were significantly higher in the 800BUD group than in the MON-400BUD group. Body mass index and changes in ACT, FEV1%, 6-min walk distance and PFS from baseline were all significant determinants for distinguishing subjects with well-controlled and partly controlled asthma from those with uncontrolled asthma (P<0.05) at the end of the study. Conclusions The efficacy of 12-week treatment with MON-400BUD in older asthmatics was comparable to that of 800BUD on asthma control but associated with reduced frequency of asthma exacerbations requiring oral steroids and sore throat events. Changes in ACT and PFS can be useful predictors of asthma control status in older patients. PMID:26122504

  13. Linking Changes to Intraspecific Trait Diversity to Community Functional Diversity and Biomass in Response to Snow and Nitrogen Addition Within an Inner Mongolian Grassland

    PubMed Central

    Mao, Wei; Felton, Andrew J.; Zhang, Tonghui

    2017-01-01

    In recent years, both the intraspecific and interspecific functional diversity (FD) of plant communities have been studied with new approaches to improve an understanding about the mechanisms underlying plant species coexistence. Yet, little is known about how global change drivers will impact intraspecific FD and trait overlap among species, and in particular how this may scale to impacts on community level FD and ecosystem functioning. To address this uncertainty, we assessed the direct and indirect responses of specific leaf area (SLA) among both dominant annual and subordinate perennial species to the independent and interactive effects of nitrogen and snow addition within the Inner Mongnolian steppe. More specifically, we investigated the consequences for these responses on plant community FD, trait overlap and biomass. Nitrogen addition increased the biomass of the dominant annual species and as a result increased total community biomass. This occurred despite concurrent decreases in the biomass of subordinate perennial species. Nitrogen addition also increased intraspecific FD and trait overlap of both annual species and perennial species, and consequently increased the degree of trait overlap in SLA at the community level. However, snow addition did not significantly impact intraspecific FD and trait overlap of SLA for perennial species, but increased intraspecific FD and trait overlap of annual species, of which scaled to changes in community level FD. We found that the responses of the dominant annual species to nitrogen and snow additions were generally more sensitive than the subordinate perennial species within the inner Mongolian grassland communities of our study. As a consequence of this sensitivity, the responses of the dominant species largely drove impacts to community FD, trait overlap and community biomass. In total, our study demonstrates that the responses of dominant species in a community to environmental change may drive the initial

  14. 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

  15. 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.

  16. "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…

  17. Discovery of Novel DNA Gyrase Inhibiting Spiropyrimidinetriones: Benzisoxazole Fusion with N-Linked Oxazolidinone Substituents Leading to a Clinical Candidate (ETX0914).

    PubMed

    Basarab, Gregory S; Doig, Peter; Galullo, Vincent; Kern, Gunther; Kimzey, Amy; Kutschke, Amy; Newman, Joseph P; Morningstar, Marshall; Mueller, John; Otterson, Linda; Vishwanathan, Karthick; Zhou, Fei; Gowravaram, Madhusudhan

    2015-08-13

    A novel class of bacterial type-II topoisomerase inhibitor displaying a spiropyrimidinetrione architecture fused to a benzisoxazole scaffold shows potent activity against Gram-positive and fastidious Gram-negative bacteria. Here, we describe a series of N-linked oxazolidinone substituents on the benzisoxazole that improve upon the antibacterial activity of initially described compounds of the class, show favorable PK properties, and demonstrate efficacy in an in vivo Staphylococcus aureus infection model. Inhibition of the topoisomerases DNA gyrase and topoisomerase IV from both Gram-positive and a Gram-negative organisms was demonstrated. Compounds showed a clean in vitro toxicity profile, including no genotoxicity and no bone marrow toxicity at the highest evaluated concentrations or other issues that have been problematic for some fluoroquinolones. Compound 1u was identified for advancement into human clinical trials for treatment of uncomplicated gonorrhea based on a variety of beneficial attributes including the potent activity and the favorable safety profile.

  18. Synthesis of binder-like molecules covalently linked to silicon nanoparticles and application as anode material for lithium-ion batteries without the use of electrolyte additives

    NASA Astrophysics Data System (ADS)

    Assresahegn, Birhanu Desalegn; Bélanger, Daniel

    2017-03-01

    A chemically modified silicon anode is prepared for application as anode in lithium-ion batteries by covalent attachment of polyacrylic acid to enable self-adhesion between the active material particles. The polyacrylic acid polymer is formed by atom transfer radical polymerization using 1-(bromoethyl)benzene initiator groups initially bonded to a hydrogenated silicon surface. The grafting of 1-(bromoethyl)benzene and polyacrylic acid is confirmed by various material characterization techniques. The electrochemical performance of the silicon anodes is also evaluated by galvanostatic cycling. The chemically modified composite silicon anode (with active material loading of 0.9-1 mg cm-2) showed a significantly improved performance in terms of: gravimetric capacitance (more than 2000 mAh g-1) after 300 cycles and 80% capacity retention with an average 99.6% Coulombic efficiency at a current density of 0.34 A g-1. However, the unmodified electrode cycled 75 times in the same conditions only retains 46% of its initial capacity with an average 95.1% Coulombic efficiency. The new composite Si electrode performs better at high charge/discharge rate and allows the use of larger proportion of the active material by reducing the amount of binder. It is noteworthy that these composite silicon electrodes are tested without the use of expensive electrolyte additives.

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

    PubMed

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

    2012-05-29

    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.

  20. 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.

  1. Great Earthquakes and Tsunami Day for Teachers on the Leading Edge: Geologic Hazards and Links to EarthScope in a Field-Based Program

    NASA Astrophysics Data System (ADS)

    Butler, R.; Bishop, E. M.; Ault, C.; Magura, B.; Hedeen, C.; Connor, D.; Southworth-Neumeyer, T.; Conrey, R.

    2005-12-01

    Inviting K-12 science teachers into the field to observe the work of professional geologists and engage in learning that is scientifically important and socially relevant deepens their geologic understanding while instilling enthusiasm for inquiry-based instruction. "Teachers on the Leading Edge" (TOTLE) is a field-based and place-based teacher development program that features active continental margin geology of the Pacific Northwest. Program themes include: (1) Geophysics as fundamental to understanding plate tectonics and essential to deciphering Pacific Northwest geology that underlies a tree-covered landscape; and (2) Geologic Hazards as understandable and inevitable consequences of living on the leading edge of our continent. The two-week TOTLE 2005 field workshop traversed the active continental margin of Oregon from the Pacific Coast through the Cascade Range to accreted terranes along the Snake River. "Great Earthquakes and Tsunami Day" featured introductions to earthquake seismology and paleoseismology. Presentations on earthquake seismology with examples from the December 2004 Sumatra - Andaman earthquake and Indian Ocean tsunami provided context and background. During a morning low tide near Fort Clatsop south of Astoria, paleoseismologist Brian Atwater (USGS, Seattle) helped teachers observe and interpret drowned forests and tsunami deposits that mark four great Cascadia earthquakes of the past 2000 years. That afternoon, Darci Connor, former Tsunami Outreach Coordinator for the City of Seaside, helped teachers understand their critical role in educating K-12 students about natural hazard preparedness. In the evening, TOTLE teachers crafted their new understanding of great earthquakes and tsunami into interactive learning activities for Science Campers at Camp Kiwanilong operated by the Oregon Museum of Science and Industry. These experiences make frontier geophysical research, like GPS observations of slow earthquakes and seismic tomography of the

  2. Meiotic drive by the Y-linked D gene in Aedes aegypti (L.) (Diptera: Culicidae) is associated with disruption of spermiogenesis, leading to premature senescence of spermatozoa.

    PubMed

    Owusu-Daaku, K O; Butler, R D; Wood, R J

    2007-06-01

    Y chromosome meiotic drive in the mosquito Aedes aegypti, due to the gene D (Distorter) in coupling with M (male determination) [the MD haplotype], is associated with spermiogenic disruption, leading to senescence, at a rate proportionate to male excess. Spermiogenesis was compared between 'Enhanced Mutant' males with a strongly female-depleted sex ratio (8.9% females), 'Mutant' males showing a lesser degree of distortion (38.3% females), and two controls with normal sex ratios (51.2% and 49.2% females). Sections of testes dissected from mature pupae and adults aged 0, 4, 8, 12 and 16 days were examined by transmission electron microscopy. A difference between Mutant and control spermiogenesis was apparent as early as the pupal stage when some Mutant spermatids showed extra tail elements (axonemes and/or mitochondrial derivatives). The same was true of Enhanced Mutant males but to a more extreme degree. Sperm senescence was evident in Enhanced Mutant testes from day 0 of adult life but in Mutant testes not until day 4. Progressive disorganisation was associated with many loose organelles, and disturbance of the anterior-posterior axis of gamete differentiation within the testis. Degenerative changes of a similar kind in the controls did not become apparent until day 8. These findings are discussed with respect to other characteristics of this meiotic drive system, in terms of a theory of inhibition of reduction division in spermatogenesis associated with fragmentation of the X chromosome, leading to the formation of a restitution nucleus as early as metaphase 1.

  3. Post-translational modification of the NKG2D ligand RAET1G leads to cell surface expression of a glycosylphosphatidylinositol-linked isoform.

    PubMed

    Ohashi, Maki; Eagle, Robert A; Trowsdale, John

    2010-05-28

    NKG2D is an important activating receptor on lymphocytes. In human, it interacts with two groups of ligands: the major histocompatibility complex class I chain-related A/B (MICA/B) family and the UL-16 binding protein (ULBP) family, also known as retinoic acid early transcript (RAET1). MIC proteins are membrane-anchored, but all of the ULBP/RAET1 proteins, except for RAET1E and RAET1G, are glycosylphosphatidylinositol (GPI)-anchored. To address the reason for these differences we studied the association of RAET1G with the membrane. Using epitope-tagged RAET1G protein in conjunction with antibodies to different parts of the molecule and in pulse-chase experiments, we showed that the C terminus of the protein was cleaved soon after protein synthesis. Endoglycosidase H and peptide N-glycosidase treatment and cell surface immunoprecipitation indicated that most of the protein stayed in the endoplasmic reticulum, but some of the cleaved form was modified in the Golgi and transported to the cell surface. We examined the possibility of GPI anchoring of the protein in three ways: (i) Phosphatidylinositol (PI)-specific phospholipase C released the PI-linked form of the protein. (ii) The surface expression pattern of RAET1G decreased in cells defective in GPI anchoring through mutant GPI-amidase. (iii) Site-directed mutagenesis, to disrupt residues predicted to facilitate GPI-anchoring, resulted in diminished surface expression of RAET1G. Thus, a form of RAET1G is GPI-anchored, in line with most other ULBP/RAET1 family proteins. The cytoplasmic tail and transmembrane domains appear to result from gene duplication and frameshift mutation. Together with our previous results, our data suggest that RAET1G is regulated post-translationally to produce a GPI-anchored isoform.

  4. Post-translational Modification of the NKG2D Ligand RAET1G Leads to Cell Surface Expression of a Glycosylphosphatidylinositol-linked Isoform*

    PubMed Central

    Ohashi, Maki; Eagle, Robert A.; Trowsdale, John

    2010-01-01

    NKG2D is an important activating receptor on lymphocytes. In human, it interacts with two groups of ligands: the major histocompatibility complex class I chain-related A/B (MICA/B) family and the UL-16 binding protein (ULBP) family, also known as retinoic acid early transcript (RAET1). MIC proteins are membrane-anchored, but all of the ULBP/RAET1 proteins, except for RAET1E and RAET1G, are glycosylphosphatidylinositol (GPI)-anchored. To address the reason for these differences we studied the association of RAET1G with the membrane. Using epitope-tagged RAET1G protein in conjunction with antibodies to different parts of the molecule and in pulse-chase experiments, we showed that the C terminus of the protein was cleaved soon after protein synthesis. Endoglycosidase H and peptide N-glycosidase treatment and cell surface immunoprecipitation indicated that most of the protein stayed in the endoplasmic reticulum, but some of the cleaved form was modified in the Golgi and transported to the cell surface. We examined the possibility of GPI anchoring of the protein in three ways: (i) Phosphatidylinositol (PI)-specific phospholipase C released the PI-linked form of the protein. (ii) The surface expression pattern of RAET1G decreased in cells defective in GPI anchoring through mutant GPI-amidase. (iii) Site-directed mutagenesis, to disrupt residues predicted to facilitate GPI-anchoring, resulted in diminished surface expression of RAET1G. Thus, a form of RAET1G is GPI-anchored, in line with most other ULBP/RAET1 family proteins. The cytoplasmic tail and transmembrane domains appear to result from gene duplication and frameshift mutation. Together with our previous results, our data suggest that RAET1G is regulated post-translationally to produce a GPI-anchored isoform. PMID:20304922

  5. Disruption of RAB40AL function leads to Martin–Probst syndrome, a rare X-linked multisystem neurodevelopmental human disorder

    PubMed Central

    Bedoyan, Jirair Krikor; Schaibley, Valerie M; Peng, Weiping; Bai, Yongsheng; Mondal, Kajari; Shetty, Amol C; Durham, Mark; Micucci, Joseph A; Dhiraaj, Arti; Skidmore, Jennifer M; Kaplan, Julie B; Skinner, Cindy; Schwartz, Charles E; Antonellis, Anthony; Zwick, Michael E; Cavalcoli, James D; Li, Jun Z

    2012-01-01

    Background and aim Martin–Probst syndrome (MPS) is a rare X-linked disorder characterised by deafness, cognitive impairment, short stature and distinct craniofacial dysmorphisms, among other features. The authors sought to identify the causative mutation for MPS. Methods and results Massively parallel sequencing in two affected, related male subjects with MPS identified a RAB40AL (also called RLGP) missense mutation (chrX:102,079,078-102,079,079AC→GA p.D59G; hg18). RAB40AL encodes a small Ras-like GTPase protein with one suppressor of cytokine signalling box. The p.D59G variant is located in a highly conserved region of the GTPase domain between β-2 and β-3 strands. Using RT-PCR, the authors show that RAB40AL is expressed in human fetal and adult brain and kidney, and adult lung, heart, liver and skeletal muscle. RAB40AL appears to be a primate innovation, with no orthologues found in mouse, Xenopus or zebrafish. Western analysis and fluorescence microscopy of GFP-tagged RAB40AL constructs from transiently transfected COS7 cells show that the D59G missense change renders RAB40AL unstable and disrupts its cytoplasmic localisation. Conclusions This is the first study to show that mutation of RAB40AL is associated with a human disorder. Identification of RAB40AL as the gene mutated in MPS allows for further investigations into the molecular mechanism(s) of RAB40AL and its roles in diverse processes such as cognition, hearing and skeletal development. PMID:22581972

  6. 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.

  7. From linked open data to molecular interaction: studying selectivity trends for ligands of the human serotonin and dopamine transporter† †The authors declare no competing interests. ‡ ‡Electronic supplementary information (ESI) available. See DOI: 10.1039/c6md00207b Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file.

    PubMed Central

    Hellsberg, Eva; Viereck, Michael; Ecker, Gerhard F.

    2016-01-01

    Retrieval of congeneric and consistent SAR data sets for protein targets of interest is still a laborious task to do if no appropriate in-house data set is available. However, combining integrated open data sources (such as the Open PHACTS Discovery Platform) with workflow tools now offers the possibility of querying across multiple domains and tailoring the search to the given research question. Starting from two phylogenetically related protein targets of interest (the human serotonin and dopamine transporters), the whole chemical compound space was explored by implementing a scaffold-based clustering of compounds possessing biological measurements for both targets. In addition, potential hERG blocking liabilities were included. The workflow allowed studying the selectivity trends of scaffold series, identifying potentially harmful compound series, and performing SAR, docking studies and molecular dynamics (MD) simulations for a consistent data set of 56 cathinones. This delivered useful insights into driving determinants for hDAT selectivity over hSERT. With respect to the scaffold-based analyses it should be noted that the cathinone data set could be retrieved only when Murcko scaffold analyses were combined with similarity searches such as a common substructure search. PMID:27891211

  8. 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.

  9. 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.

  10. Study of electrochemically active carbon, Ga2O3 and Bi2O3 as negative additives for valve-regulated lead-acid batteries working under high-rate, partial-state-of-charge conditions

    NASA Astrophysics Data System (ADS)

    Zhao, Li; Chen, Baishuang; Wu, Jinzhu; Wang, Dianlong

    2014-02-01

    Electrochemically active carbon (EAC), Gallium (III) oxide (Ga2O3) and Bismuth (III) oxide (Bi2O3) are used as the negative additives of valve-regulated lead-acid (VRLA) batteries to prolong the cycle life of VRLA batteries under high-rate partial-state-of-charge (HRPSoC) conditions, and their effects on the cycle life of VRLA batteries are investigated. It is found that the addition of EAC in negative active material can restrain the sulfation of the negative plates and prolong the cycle performance of VRLA batteries under HRPSoC conditions. It is also observed that the addition of Ga2O3 or Bi2O3 in EAC can effectively increase the overpotential of hydrogen evolution on EAC electrodes, and decrease the evolution rate of hydrogen. An appropriate addition amount of Ga2O3 or Bi2O3 in the negative plates of VRLA batteries can decrease the cut-off charging voltage, increase the cut-off discharging voltage, and prolong the cycle life of VRLA batteries under HRPSoC conditions. The battery added with 0.5% EAC and 0.01% Ga2O3 in negative active material shows a lowest cut-off charging voltage and a highest cut-off discharging voltage under HRPSoC conditions, and its' cycle life reaches about 8100 cycles which is at least three times longer than that without Ga2O3.

  11. 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

  12. The link in Linking.

    PubMed

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

    2013-05-01

    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.

  13. Hydrogen bonding asymmetric star-shape derivative of bile acid leads to supramolecular fibrillar aggregates that wrap into micrometer spheres† †Electronic supplementary information (ESI) available: Materials and methods, experimental section, and characterization. See DOI: 10.1039/c6sm01329e Click here for additional data file. Click here for additional data file. Click here for additional data file.

    PubMed Central

    Myllymäki, Teemu T. T.; Yang, Hongjun; Liljeström, Ville; Kostiainen, Mauri A.; Malho, Jani-Markus; Zhu, X. X.

    2016-01-01

    We report that star-shaped molecules with cholic acid cores asymmetrically grafted by low molecular weight polymers with hydrogen bonding end-groups undergo aggregation to nanofibers, which subsequently wrap into micrometer spherical aggregates with low density cores. Therein the facially amphiphilic cholic acid (CA) is functionalized by four flexible allyl glycidyl ether (AGE) side chains, which are terminated with hydrogen bonding 2-ureido-4[1H]pyrimidinone (UPy) end-groups as connected by hexyl spacers, denoted as CA(AGE6-C6H12-UPy)4. This wedge-shaped molecule is expected to allow the formation of a rich variety of solvent-dependent structures due to the complex interplay of interactions, enabled by its polar/nonpolar surface-active structure, the hydrophobicity of the CA in aqueous medium, and the possibility to control hydrogen bonding between UPy molecules by solvent selection. In DMSO, the surfactant-like CA(AGE6-C6H12-UPy)4 self-assembles into nanometer scale micelles, as expected due to its nonpolar CA apexes, solubilized AGE6-C6H12-UPy chains, and suppressed mutual hydrogen bonds between the UPys. Dialysis in water leads to nanofibers with lateral dimensions of 20–50 nm. This is explained by promoted aggregation as the hydrogen bonds between UPy molecules start to become activated, the reduced solvent dispersibility of the AGE-chains, and the hydrophobicity of CA. Finally, in pure water the nanofibers wrap into micrometer spheres having low density cores. In this case, strong complementary hydrogen bonds between UPy molecules of different molecules can form, thus promoting lateral interactions between the nanofibers, as allowed by the hydrophobic hexyl spacers. The wrapping is illustrated by transmission electron microscopy tomographic 3D reconstructions. More generally, we foresee hierarchically structured matter bridging the length scales from molecular to micrometer scale by sequentially triggering supramolecular interactions. PMID:27491728

  14. Additive Manufactured Product Integrity

    NASA Technical Reports Server (NTRS)

    Waller, Jess; Wells, Doug; James, Steve; Nichols, Charles

    2017-01-01

    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.

  15. Lead Poisoning

    MedlinePlus

    ... be exposed to lead by Eating food or drinking water that contains lead. Water pipes in older homes ... herbs or foods that contain lead Breathing air, drinking water, eating food, or swallowing or touching dirt that ...

  16. 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.

  17. 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…

  18. Lead Toxicity

    MedlinePlus

    ... including some imported jewelry. What are the health effects of lead? • More commonly, lower levels of lead in children over time may lead to reduced IQ, slow learning, Attention Deficit Hyperactivity Disorder (ADHD), or behavioral issues. • Lead also affects other ...

  19. 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.

  20. 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

  1. Forging Links.

    ERIC Educational Resources Information Center

    Stewig, John Warren

    Blacksmiths and their craft have changed with the times, and as times change for teachers, they too should be forgers of links. Teacher-to-teacher links should extend beyond the faculty lounge to support systems and active groups of individuals concerned about each other. Another personal link can be made by developing a grade level, system-wide…

  2. Co-treatment with the non-steroidal anti-androgen drug, flutamide and the natural estrogen, 17β-estradiol does not lead to additive reproductive impairment in juvenile Murray rainbowfish (Melanotaenia fluviatilis).

    PubMed

    Bhatia, Harpreet; Kumar, Anupama; Du, Jun; Chapman, John C; McLaughlin, Mike J

    2015-11-01

    The aim of this study was to investigate if the anti-androgen, flutamide, and the estrogen, 17β-estradiol work together to feminize juvenile Murray rainbowfish (Melanotaenia fluviatilis). Fish (60 days post-hatch) were exposed to 25 ng/L 17β-estradiol (E2), 25 µg/L flutamide (Flu low), 250 µg/L flutamide (Flu high), E2 + Flu low and E2 + Flu high. After 35 days of exposure, concentrations of sex steroid hormones, 17β-estradiol and 11-keto testosterone (11-KT), were determined in the head; and vitellogenin (VTG) concentration was measured in the tail. The abdomens were used for histological investigation of the gonads. Treatment with E2 + Flu high resulted in reduction in body weights and lengths in males and condition factor in females. Intersex was noted in Flu high and E2 + Flu high treatments. Exposures to E2 and/or Flu (low and high) resulted in precocious oocyte development but inhibited sperm development. The 17β-estradiol levels decreased significantly in the heads of both sexes after exposures to E2 and/or Flu (high and low). Flu high and E2 alone increased the 11-KT levels in both sexes. However, E2 + Flu low decreased 11-KT levels in males and increased them in females. Flutamide (low and high) induced VTG protein in the tails of both sexes. In males, VTG was not induced in the tail after exposure to E2. No significant effect of flutamide on E2-induced VTG concentration was noted. We conclude that co-treatment with flutamide and 17β-estradiol does not lead to additive reproductive impairment in juvenile Murray rainbowfish.

  3. Fuel additives

    SciTech Connect

    Gheysens, J.L.G.

    1990-11-27

    This patent describes a composition for the improvement of hydrocarbon fuels exhibiting a boiling range of gasoline being suitable for use in spark ignition-type engines. It comprises an aromatic amine; a polyaminated detergent; a catalyst comprising a colloidal suspension or amine salt of transition/alkali/alkaline earth metal organic coordinations having at least one metal oxidehydroxide linked to an alkyl chain via a carboxyl group; and a solvent comprising an alkanol-aliphatic ether oxygenated hydrocarbon.

  4. Lead Poisoning

    MedlinePlus

    ... from lead poisoning in New Hampshire and in Alabama. Lead poisoning has also been associated with juvenile ... for decades—after it first enters the blood stream. (The same process can occur with the onset ...

  5. Lead poisoning

    MedlinePlus

    ... Failure at school Hearing problems Kidney damage Reduced IQ Slowed body growth The symptoms of lead poisoning ... can have a permanent impact on attention and IQ. People with higher lead levels have a greater ...

  6. Food additives

    MedlinePlus

    ... or natural. Natural food additives include: Herbs or spices to add flavor to foods Vinegar for pickling ... Certain colors improve the appearance of foods. Many spices, as well as natural and man-made flavors, ...

  7. 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…

  8. 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.

  9. 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)

  10. 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.

  11. 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...

  12. 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.

  13. 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

  14. Lead contamination of urban snow.

    PubMed

    Grandstaff, D E; Myer, G H

    1979-01-01

    Lead content of newly fallen snow in an urban area ranges from 34 to 56 ppb. After falling, snow may incorporate major additional amounts of lead by dry deposition of lead aerosols from local sources. The highest concentration found was 2,700 ppb. Ingestion of lead-contaminated snow might pose a health hazard to inner city children.

  15. Who Leads China's Leading Universities?

    ERIC Educational Resources Information Center

    Huang, Futao

    2017-01-01

    This study attempts to identify the major characteristics of two different groups of institutional leaders in China's leading universities. The study begins with a review of relevant literature and theory. Then, there is a brief introduction to the selection of party secretaries, deputy secretaries, presidents and vice presidents in leading…

  16. Loss of BMP signaling through BMPR1A in osteoblasts leads to greater collagen cross-link maturation and material-level mechanical properties in mouse femoral trabecular compartments.

    PubMed

    Zhang, Yanshuai; McNerny, Erin Gatenby; Terajima, Masahiko; Raghavan, Mekhala; Romanowicz, Genevieve; Zhang, Zhanpeng; Zhang, Honghao; Kamiya, Nobuhiro; Tantillo, Margaret; Zhu, Peizhi; Scott, Gregory J; Ray, Manas K; Lynch, Michelle; Ma, Peter X; Morris, Michael D; Yamauchi, Mitsuo; Kohn, David H; Mishina, Yuji

    2016-07-01

    Bone morphogenetic protein (BMP) signaling pathways play critical roles in skeletal development and new bone formation. Our previous study, however, showed a negative impact of BMP signaling on bone mass because of the osteoblast-specific loss of a BMP receptor (i.e. BMPR1A) showing increased trabecular bone volume and mineral density in mice. Here, we investigated the bone quality and biomechanical properties of the higher bone mass associated with BMPR1A deficiency using the osteoblast-specific Bmpr1a conditional knockout (cKO) mouse model. Collagen biochemical analysis revealed greater levels of the mature cross-link pyridinoline in the cKO bones, in parallel with upregulation of collagen modifying enzymes. Raman spectroscopy distinguished increases in the mature to immature cross-link ratio and mineral to matrix ratio in the trabecular compartments of cKO femora, but not in the cortical compartments. The mineral crystallinity was unchanged in the cKO in either the trabecular or cortical compartments. Further, we tested the intrinsic material properties by nanoindentation and found significantly higher hardness and elastic modulus in the cKO trabecular compartments, but not in the cortical compartments. Four point bending tests of cortical compartments showed lower structural biomechanical properties (i.e. strength and stiffness) in the cKO bones due to the smaller cortical areas. However, there were no significant differences in biomechanical performance at the material level, which was consistent with the nanoindentation test results on the cortical compartment. These studies emphasize the pivotal role of BMPR1A in the determination of bone quality and mechanical integrity under physiological conditions, with different impact on femoral cortical and trabecular compartments.

  17. [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.

  18. Transatlantic link

    NASA Astrophysics Data System (ADS)

    (left) European Geophysical Society (EGS) President Rolf Meissner at AGU Headquarters with (center) Executive Director Fred Spilhaus and (right) Foreign Secretary Juan Roederer. Meissner attended the meeting of AGU's Committee on International Participation (CIP) on February 26, 1988. At that meeting, specific ways of fostering close links between AGU and EGS were discussed.A few weeks later, Roederer and AGU staff, working with EGS Secretary-General Arne Richter at the EGS meeting in Bologna, Italy, March 21-25, planned details of the establishment of an AGU office in Europe. The Copernicus Gesellschaft, a new entity located on the premises of the Max Planck Institute for Aeronomy in Lindau, Federal Republic of Germany, will provide the administrative staff and handle logistics.

  19. Alterations of lead speciation by sulfate from addition of flue ...

    EPA Pesticide Factsheets

    This is the first study to evaluate the potential application of FGDG as an in situ Pb stabilizer in contaminated soils with two different compositions and to explain the underlying mechanisms. A smelter Pb contaminated soil (SM-soil), rich in ferrihydrite bound Pb (FH-Pb), cerussite and litharge with a total Pb content of 65,123 mg/kg and an organic matter rich orchard soil (BO-soil), rich in FH-Pb and humic acid bound Pb with a total Pb content of 1532 mg/kg were amended with 5% FGDG (w/w). We subjected the two soils to three leaching tests; toxicity characteristic leaching protocol (TCLP), synthetic precipitation leaching protocol (SPLP), kinetic batch leaching test (KBLT) and in-vitro bioaccessibility assay (IVBA) in order to evaluate the FGDG amendment on Pb stabilization. Solid residues of original and FGDG amended soil were analyzed using X-ray absorption spectroscopy (XAS) to identify changes in Pb speciation after each leaching test. The leachate Pb concentrations of FGDG amended soil were lowered compared to those of in non-amended soil. The linear combination fitting analysis of XAS confirmed the formation of anglesite and leadhillite in FGDG amended in soil. FGDG reduced the Pb desorption from ferrihydrite (FH), by forming FH-Pb-SO4 ternary complexes. FGDG decreased the Pb adsorption onto humic acid (HA) possibly due to the release of divalent cations such as Ca and Mg, which can compete with Pb to get adsorbed onto HA. The FGDG can successful

  20. LinkProt: a database collecting information about biological links

    PubMed Central

    Dabrowski-Tumanski, Pawel; Jarmolinska, Aleksandra I.; Niemyska, Wanda; Rawdon, Eric J.; Millett, Kenneth C.; Sulkowska, Joanna I.

    2017-01-01

    Protein chains are known to fold into topologically complex shapes, such as knots, slipknots or complex lassos. This complex topology of the chain can be considered as an additional feature of a protein, separate from secondary and tertiary structures. Moreover, the complex topology can be defined also as one additional structural level. The LinkProt database (http://linkprot.cent.uw.edu.pl) collects and displays information about protein links — topologically non-trivial structures made by up to four chains and complexes of chains (e.g. in capsids). The database presents deterministic links (with loops closed, e.g. by two disulfide bonds), links formed probabilistically and macromolecular links. The structures are classified according to their topology and presented using the minimal surface area method. The database is also equipped with basic tools which allow users to analyze the topology of arbitrary (bio)polymers. PMID:27794552

  1. 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.

  2. 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...

  3. 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.

  4. 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.

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

    PubMed Central

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

    1988-01-01

    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 and biochemical changes affecting the musculature of the heart and vasculature, hypertension, hypercholesterolemia, atherosclerosis, and increased vascular reactivity to alpha-adrenergic agonists have been among the reported cardiovascular disturbances linked to lead poisoning. Less certain are the cardiovascular effects of subclinical 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. Evidence points to the involvement of multiple sites of action. Cardiac and vascular sites, as well as sites within the central nervous system, have all been implicated in the sequelae of cardiovascular effects. The exact pathogenic mechanisms that underlie the actions of lead in the cardiovascular system

  6. Additive Effects on Asymmetric Catalysis.

    PubMed

    Hong, Liang; Sun, Wangsheng; Yang, Dongxu; Li, Guofeng; Wang, Rui

    2016-03-23

    This review highlights a number of additives that can be used to make asymmetric reactions perfect. Without changing other reaction conditions, simply adding additives can lead to improved asymmetric catalysis, such as reduced reaction time, improved yield, or/and increased selectivity.

  7. Food Exposures to Lead

    PubMed Central

    Kolbye, Albert C.; Mahaffey, Kathryn R.; Fiorino, John A.; Corneliussen, Paul C.; Jelinek, Charles F.

    1974-01-01

    Exposures to lead have emanated from various sources, including food, throughout human history. Occupational and environmental exposures (especially pica) appear to account for much of the identified human disease, however, food-borne exposures deserve further investigation. Lead residues in food can result from: biological uptake from soils into plants consumed by food animals or man, usage of lead arsenate pesticides, inadvertent addition during food processing, and by leaching them improperly glazed pottery used as food storage or dining utensils. Estimates of total dietary exposure should reflect frequency distribution data on lead levels in specific food commodities in relation to the quantities actually ingested by various sample populations to distinguish degrees of risk associated with particular dietary habits. Earlier estimates of average total dietary intake of lead by adults have been reported to range from above 500 μg/day downward with more recent estimates suggesting averages of 200 μg/day or lower. The strengths and weaknesses of these data are discussed along with analytical and sampling considerations. FDA programs related to food surveillance, epidemiology, and toxicological investigation are briefly described. PMID:4406646

  8. Linking marine biology and biotechnology.

    PubMed

    de Nys, Rocky; Steinberg, Peter D

    2002-06-01

    Studies of biological systems in which there is a direct link between the challenges faced by marine organisms and biotechnologies enable us to rationally search for active natural compounds and other novel biotechnologies. This approach is proving successful in developing new methods for the prevention of marine biofouling and for the identification of new lead compounds for the development of ultraviolet sunscreens.

  9. 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)

  10. 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…

  11. 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...

  12. Lead/acid batteries

    NASA Astrophysics Data System (ADS)

    Bullock, Kathryn R.

    Lead/acid batteries are produced in sizes from less than 1 to 3000 Ah for a wide variety of portable, industrial and automotive applications. Designs include Planté, Fauré or pasted, and tubular electrodes. In addition to the traditional designs which are flooded with sulfuric acid, newer 'valve-regulated" designs have the acid immolibized in a silica gel or absorbed in a porous glass separator. Development is ongoing worldwide to increase the specific power, energy and deep discharge cycle life of this commercially successful system to meet the needs of new applications such as electric vehicles, load leveling, and solar energy storage. The operating principles, current status, technical challenges and commercial impact of the lead/acid battery are reviewed.

  13. Environmental lead in Mexico.

    PubMed

    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. Lead in gasoline is still used at very high concentrations in all the country, with the exception of Mexico City and its surrounding area, while no studies have been carried out to determine the potential health and environmental impact of this practice in regions outside Mexico City. Despite the fact that the Torre

  14. 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 ...

  15. Abnormal mortality of octopus after a storm water event: Accumulated lead and lead isotopes as fingerprints.

    PubMed

    Raimundo, J; Ruano, F; Pereira, J; Mil-Homens, M; Brito, P; Vale, C; Caetano, M

    2017-03-01

    Octopus vulgaris is a sedentary organism that inhabits coastal waters being exposed to anthropogenic compounds. Lead concentration in coastal environments reflects many processes and activities namely weathering, industrial and domestic discharges, and atmospheric deposition. Since lead isotopic composition is little affected by kinetic processes occurring between source and sink, its signature has been used to identify different Pb sources. After a short-term heavy rainfall, hundreds of octopus appeared dead in two Portuguese coastal areas. Histopathology and Pb levels and its stable isotopes were determined in tissues, such as digestive gland, of stranded octopus and compared to alive specimens, sediments and runoff material from the same areas. Histology results showed severe damage in stranded octopus tissues suggesting that death was probably associated to multiple organ failure linked to hypertrophy and exudates input. In addition, Pb in stranded specimens reach concentrations up to one order of magnitude above the levels reported for alive octopus. Pb isotopic signatures in stranded organisms were closer to runoff material pointing to a similar origin of Pb. In summary, the results in this study showed that a short-term runoff event might change abruptly the salinity leading to the disruption of the osmoregulation function of octopus and consequently leading to its death. The analyses of stable isotopic Pb signature in octopus tissues corroborate these results and points to a change in the Pb source due to runoff after the storm water event. Pb stable isotopes in octopus proved to be an adequate tool to confirm the cause of death and linking it to the environment conditions.

  16. Lead and Your Baby

    MedlinePlus

    ... yourself and your family from lead in drinking water? Drinking water may contain lead if you have ... yourself and your family from lead in drinking water? Drinking water may contain lead if you have ...

  17. Structural link between giant molybdenum oxide based ions and derived Keggin structure: modular assemblies based on the [BW11O39]9- ion and pentagonal {M'M5} units (M' = W; M = Mo,W).

    PubMed

    Leclerc-Laronze, Nathalie; Marrot, Jérôme; Thouvenot, René; Cadot, Emmanuel

    2009-01-01

    Linked to the Pentagon: The addition of molybdate to [HBW(11)O(39)](8-) ions leads to the formation of mixed pentagonal units {W(Mo(5))} and {W(WMo(4))} trapped as linkers in the resulting modular assemblies, thus establishing the first link between the conventional Keggin ion derivatives and the giant molybdenum oxide and keplerate ions.

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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.

  3. 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.

  4. The Kidney in Lead Poisoning

    PubMed Central

    Radošević, Zdenko; Šarić, Marko; Beritić, Tihomil; Knežević, Jelica

    1961-01-01

    Kidney damage due to lead is still an interesting problem of industrial toxicology. In spite of abundant literature data, much still remains to be explained. There are controversial opinions, not only on the type of renal lesions due to lead, but also on whether lead affects the kidney at all. In this paper our clinical observations on the effect of lead upon the kidney in 53 patients suffering from lead poisoning are presented. In 44 patients (40 men and four women) lead poisoning was due to occupation, and in nine (five men and four women) to the use of lead-glazed pottery. The length of exposure varied from two months to 35 years. In all cases the diagnosis of lead poisoning was made clinically and confirmed by laboratory tests. Permanent changes in the form of chronic nephropathy were observed in only two patients. These were the two cases in which exposure to lead was the longest and most intense. Twenty-three patients showed functional renal lesions tending to normalize. In addition to the cases of organic nephropathy, blood pressure was persistently raised in one further patient; in two patients a raised blood pressure was observed only in the acute stage of poisoning. On the basis of these findings we consider that lead intoxication can cause renal lesions. These lesions are for the most part functional and temporary. In cases of long and severe exposure and repeated lead intoxication, organic renal lesions seem possible. The disturbances of renal function observed in this study may be ascribed to disordered intrarenal circulation, due to the spastic effect of lead on intrarenal blood vessels, and to a direct toxic or indirect hypoxic effect of lead on the tubules. When investigating renal function, we have observed that the timing of individual tests is of paramount importance. Some lesions are subject to changes in the natural course of lead poisoning, and unless this is borne in mind, apparently contradictory results may be obtained. PMID:13739013

  5. Slow down of actin depolymerization by cross-linking molecules.

    PubMed

    Schmoller, Kurt M; Semmrich, Christine; Bausch, Andreas R

    2011-02-01

    The ability to control the assembly and disassembly dynamics of actin filaments is an essential property of the cellular cytoskeleton. While many different proteins are known which accelerate the polymerization of monomers into filaments or promote their disintegration, much less is known on mechanisms which guarantee the kinetic stability of the cytoskeletal filaments. Previous studies indicate that cross-linking molecules might fulfill these stabilizing tasks, which in addition facilitates their ability to regulate the organization of cytoskeletal structures in vivo. The effect of depolymerization factors on such structures or the mechanism which leads finally to their disintegration remain unknown. Here, we use multiple depolymerization methods in order to directly demonstrate that cross-linking and bundling proteins effectively suppress the actin depolymerization in a concentration dependent manner. Even the actin depolymerizing factor cofilin is not sufficient to facilitate a fast disintegration of highly cross-linked actin networks unless molecular motors are used simultaneously. The drastic modification of actin kinetics by cross-linking molecules can be expected to have wide-ranging implications for our understanding of the cytoskeleton, where cross-linking molecules are omnipresent and essential.

  6. 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…

  7. Cofilin takes the lead.

    PubMed

    DesMarais, Vera; Ghosh, Mousumi; Eddy, Robert; Condeelis, John

    2005-01-01

    Cofilin has emerged as a key regulator of actin dynamics at the leading edge of motile cells. Through its actin-severing activity, it creates new actin barbed ends for polymerization and also depolymerizes old actin filaments. Its function is tightly regulated in the cell. Spatially, its activity is restricted by other actin-binding proteins, such as tropomyosin, which compete for accessibility of actin filament populations in different regions of the cell. At the molecular level, it is regulated by phosphorylation, pH and phosphatidylinositol (4,5)-bisphosphate binding downstream of signaling cascades. In addition, it also appears to be regulated by interactions with 14-3-3zeta and cyclase-associated protein. In vivo, cofilin acts synergistically with the Arp2/3 complex to amplify local actin polymerization responses upon cell stimulation, which gives it a central role in setting the direction of motility in crawling cells.

  8. 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.

  9. Lead levels - blood

    MedlinePlus

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

  10. Analog Optical Links

    NASA Astrophysics Data System (ADS)

    Cox, Charles H., III

    2004-05-01

    Unlike books that focus on the devices used in links, such as lasers and photodiodes, among others, this text focuses on the next level. It covers the collection of devices that form a link, how the individual device performance affects the link performance, or the reverse. Analog links are used for the distribution of cable TV signals, and in conveying the signals to and from antennas (so called antenna remoting). The design of analog links differs significantly from digital links which are primarily used in telecommunications.

  11. Link performance of mobile optical links

    NASA Astrophysics Data System (ADS)

    Henniger, H.

    2007-09-01

    High data-rate atmospheric free-space optical (FSO) lasercom systems typically suffer from relatively long time duration link degradations. These are caused by pointing- and tracking-errors or deep signal-fades produced by the index of refraction fluctuations caused by atmospheric turbulence. Based on measurement results we will present in this paper a channel characterization model for free-space optical links. Further a forward-error-correction (FEC) coding scheme is introduced that is able to overcome link outages. The performance of these codes has been proven by measurements. Code design recommendations and validation test results are discussed in this paper.

  12. 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.

  13. Greased hedgehogs: new links between hedgehog signaling and cholesterol metabolism.

    PubMed

    Breitling, Rainer

    2007-11-01

    The close link between signaling by the developmental regulators of the Hedgehog family and cholesterol biochemistry has been known for some time. The morphogen is covalently attached to cholesterol in a peculiar autocatalytic reaction and embryonal disruption of cholesterol synthesis leads to malformations that mimic Hh signaling defects. Recently, it was furthermore shown that secreted Hh could hitchhike on lipoprotein particles to establish its morphogenic gradient in the developing embryo. Additionally, there is new evidence that the Hh-receptor Patched transmits the Hh signal by modulating the secretion of an inhibitory sterol molecule from the receiving cells. Here we present some of the most recent discoveries on the Hh-sterol link and discuss their implications from a systems design perspective. We predict that a robust functioning of the Hh pathway will require the involvement of more sterol metabolites, and these should be the subject of future research.

  14. Oxidative stress and mitochondrial dysfunction-linked neurodegenerative disorders.

    PubMed

    Islam, Md Torequl

    2017-01-01

    Reactive species play an important role in physiological functions. Overproduction of reactive species, notably reactive oxygen (ROS) and nitrogen (RNS) species along with the failure of balance by the body's antioxidant enzyme systems results in destruction of cellular structures, lipids, proteins, and genetic materials such as DNA and RNA. Moreover, the effects of reactive species on mitochondria and their metabolic processes eventually cause a rise in ROS/RNS levels, leading to oxidation of mitochondrial proteins, lipids, and DNA. Oxidative stress has been considered to be linked to the etiology of many diseases, including neurodegenerative diseases (NDDs) such as Alzheimer diseases, Amyotrophic lateral sclerosis, Friedreich's ataxia, Huntington's disease, Multiple sclerosis, and Parkinson's diseases. In addition, oxidative stress causing protein misfold may turn to other NDDs include Creutzfeldt-Jakob disease, Bovine Spongiform Encephalopathy, Kuru, Gerstmann-Straussler-Scheinker syndrome, and Fatal Familial Insomnia. An overview of the oxidative stress and mitochondrial dysfunction-linked NDDs has been summarized in this review.

  15. Linking Policy | Smokefree 60+

    Cancer.gov

    Links to individual pages within the Smokefree 60+ website are permissible, provided attribution is made to 60plus.smokefree.gov and any descriptive notes accurately reflect the content of the linked page(s).

  16. 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.

  17. 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.

  18. 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%…

  19. Nanoengineered Additives for Active Coatings

    DTIC Science & Technology

    2007-04-01

    commercial ad bial activ component from the coating, leading to eventual depletion of the film. Small TPU samples were evaluated using a Kirby - Bauer ...7 Table 5. Summary of 24-hr ASTM E 2180 tests with 1 weight-percent additive in PUr (solvent dispersible) based on 6-log loading of...Noveon X-1150). The ASTM E 2180 test is run in triplicate (Note that alternative ro 1° amines) was suspended in dry tetrahydrofuran (THF) (150 mL) in

  20. [Hospitals as vital links].

    PubMed

    Klink, A

    2013-01-01

    The reform of the system in 2006 aimed at reducing waiting lists in an efficient manner. Performance-linked funding and regulated competition did indeed lead to improved efficiency. The other side of the coin is overtreatment, and expensive and not infrequently damaging growth in volume. In order to control costs, three strategies have been determined: agreements with an annual cap on volume; (b) collaboration of regional health-care providers with the mission of improving results in health care (with profit-sharing if costs fall); and (c) fusions reducing the number of hospitals which reduces the burden of injuries (supply no longer creates its own demand). This article comments on these strategies. The author argues for a fourth approach: if the quality of health care improves, the number of complications will fall, overtreatment will decline and the outcome will be a decrease in burden of injuries. This requires the health care insurers to modify the way they manage their contracts and methods of payment, and stimulates competition based on quality.

  1. 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

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

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    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.

  3. 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.

  4. Additive Similarity Trees

    ERIC Educational Resources Information Center

    Sattath, Shmuel; Tversky, Amos

    1977-01-01

    Tree representations of similarity data are investigated. Hierarchical clustering is critically examined, and a more general procedure, called the additive tree, is presented. The additive tree representation is then compared to multidimensional scaling. (Author/JKS)

  5. Transboundary atmospheric lead pollution.

    PubMed

    Erel, Yigal; Axelrod, Tamar; Veron, Alain; Mahrer, Yitzak; Katsafados, Petros; Dayan, Uri

    2002-08-01

    A high-temporal resolution collection technique was applied to refine aerosol sampling in Jerusalem, Israel. Using stable lead isotopes, lead concentrations, synoptic data, and atmospheric modeling, we demonstrate that lead detected in the atmosphere of Jerusalem is not only anthropogenic lead of local origin but also lead emitted in other countries. Fifty-seven percent of the collected samples contained a nontrivial fraction of foreign atmospheric lead and had 206Pb/207Pb values which deviated from the local petrol-lead value (206Pb/207Pb = 1.113) by more than two standard deviations (0.016). Foreign 206Pb/207Pb values were recorded in Jerusalem on several occasions. The synoptic conditions on these dates and reported values of the isotopic composition of lead emitted in various countries around Israel suggest that the foreign lead was transported to Jerusalem from Egypt, Turkey, and East Europe. The average concentration of foreign atmospheric lead in Jerusalem was 23 +/- 17 ng/m3, similar to the average concentration of local atmospheric lead, 21 +/- 18 ng/ m3. Hence, the load of foreign atmospheric lead is similar to the load of local atmospheric lead in Jerusalem.

  6. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. R.; St. Clair, T. L.; Burks, H. D.; Stoakley, D. M.

    1987-01-01

    A method has been found for enhancing the melt flow of thermoplastic polyimides during processing. A high molecular weight 422 copoly(amic acid) or copolyimide was fused with approximately 0.05 to 5 pct by weight of a low molecular weight amic acid or imide additive, and this melt was studied by capillary rheometry. Excellent flow and improved composite properties on graphite resulted from the addition of a PMDA-aniline additive to LARC-TPI. Solution viscosity studies imply that amic acid additives temporarily lower molecular weight and, hence, enlarge the processing window. Thus, compositions containing the additive have a lower melt viscosity for a longer time than those unmodified.

  7. [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.

  8. 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.

  9. Lead (Pb) Air Pollution

    MedlinePlus

    ... and 2014. In 2008, EPA significantly strengthened the air quality standards for lead to provide health protection for ... time? Setting and Reviewing Standards What are lead air quality standards? How are they developed and reviewed? What ...

  10. Lead Poisoning (For Parents)

    MedlinePlus

    ... metal used in everything from construction materials to batteries, can cause serious health problems, particularly in young ... introduce lead dust into the home. water that flows through old lead pipes or faucets, if the ...

  11. Lead Content of Foodstuffs

    PubMed Central

    Mitchell, Douglas G.; Aldous, Kenneth M.

    1974-01-01

    The lead content of a number of foodstuffs, particularly baby fruit juices and milk, is reported. Samples were analyzed in quadruplicate by using an automated Delves cup atomic absorption procedure. A large proportion of the products examined contained significant amounts of lead. Of 256 metal can examined, the contents of 62% contained a lead level of 100 μg/l. or more, 37% contained 200 μg/l. or more and 12% contained 400 μg/l. lead or more. Of products in glass and aluminum containers, only 1% had lead levels in excess of 200 μg/l. Lead levels of contents also correlate with the seam length/volume ratio of the leaded seam can. A survey of bulk milk showed a mean lead level of 40 μg/l. for 270 samples; for canned evaporated milk the mean level was 202 μg/l. These data indicate a potential health hazard. PMID:4406645

  12. 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.

  13. 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 ...

  14. 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.

  15. 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.

  16. Bullet fragment–induced lead arthropathy with subsequent fracture and elevated blood lead levels

    PubMed Central

    Adkison, Jonathan; Meyers, Ridgely; Benham, Michael

    2017-01-01

    Lead foreign bodies in joint spaces, often due to projectiles such as bullets, may cause localized arthropathy. There are no reports of joint fracture related to lead arthropathy. Additionally, lead foreign bodes embedded in the joint space may be a source of systemic lead absorption, causing elevated blood lead levels and toxicity to other organs. We present a young adult patient with retained left hip joint bullet fragments who developed suspected lead arthropathy and subsequent acute left hip fracture, as well as systemic lead absorption demonstrated by elevated blood lead levels. PMID:28127147

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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…

  2. 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…

  3. 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)

  4. 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)

  5. 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.

  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. 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.

  10. 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

  11. Polylactides in additive biomanufacturing.

    PubMed

    Poh, Patrina S P; Chhaya, Mohit P; Wunner, Felix M; De-Juan-Pardo, Elena M; Schilling, Arndt F; Schantz, Jan-Thorsten; van Griensven, Martijn; Hutmacher, Dietmar W

    2016-12-15

    New advanced manufacturing technologies under the alias of additive biomanufacturing allow the design and fabrication of a range of products from pre-operative models, cutting guides and medical devices to scaffolds. The process of printing in 3 dimensions of cells, extracellular matrix (ECM) and biomaterials (bioinks, powders, etc.) to generate in vitro and/or in vivo tissue analogue structures has been termed bioprinting. To further advance in additive biomanufacturing, there are many aspects that we can learn from the wider additive manufacturing (AM) industry, which have progressed tremendously since its introduction into the manufacturing sector. First, this review gives an overview of additive manufacturing and both industry and academia efforts in addressing specific challenges in the AM technologies to drive toward AM-enabled industrial revolution. After which, considerations of poly(lactides) as a biomaterial in additive biomanufacturing are discussed. Challenges in wider additive biomanufacturing field are discussed in terms of (a) biomaterials; (b) computer-aided design, engineering and manufacturing; (c) AM and additive biomanufacturing printers hardware; and (d) system integration. Finally, the outlook for additive biomanufacturing was discussed.

  12. 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

  13. 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.

  14. 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.

  15. HLA-linked rheumatoid arthritis.

    PubMed Central

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

    1994-01-01

    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 susceptibility allele frequency as 2.16%, and 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-half of familial RA, although it accounts for only 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. PMID:7942852

  16. 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…

  17. School-Linked Services.

    ERIC Educational Resources Information Center

    Family Resource Coalition, Chicago, IL.

    Noting that educating children requires commitment and resources from the whole community as well as the schools, this document explores school-based collaborations with social services and family programs to improve students' performance. The document first provides a rationale for school-linked programs, then describes the School-Linked Services…

  18. Synthesising topological links

    DOE PAGES

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

    2014-10-14

    In this paper, 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). Finally, we suggest how to obtain both two dimensional and three dimensional objects (surfaces and solids, respectively) which also have this Brunnian property.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. The Frontiers of Additive Manufacturing

    SciTech Connect

    Grote, Christopher John

    2016-03-03

    Additive manufacturing, more commonly known as 3-D printing, has become a ubiquitous tool in science for its precise control over mechanical design. For additive manufacturing to work, a 3-D structure is split into thin 2D slices, and then different physical properties, such as photo-polymerization or melting, are used to grow the sequential layers. The level of control allows not only for devices to be made with a variety of materials: e.g. plastics, metals, and quantum dots, but to also have finely controlled structures leading to other novel properties. While 3-D printing is widely used by hobbyists for making models, it also has industrial applications in structural engineering, biological tissue scaffolding, customized electric circuitry, fuel cells, security, and more.

  4. Lead poisoning: case studies.

    PubMed

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

    2002-05-01

    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 micromol l-1 (50 microg dl-1) or in any event >3.8 micromol l-1 (80 microg dl-1) should receive sodium calciumedetate i.v., followed by succimer by mouth for 19 days. Asymptomatic patients with blood lead concentration >2.4 micromol l-1 (50 microg dl-1) may be treated with succimer alone. Sodium calciumedetate should be given with dimercaprol to treat lead encephalopathy.

  5. Immunosuppressive effects of lead

    USGS Publications Warehouse

    Franson, J. Christian; Feierabend, J.Scott; Russell, A.Brooke

    1986-01-01

    Immunosuppressive effects of lead were reported as early as 1966, when it was noted that lead increased the sensitivity of rats to bacterial endotoxins (Selye et al. 1966). Since then a substantial body of literature has demonstrated adverse effects of lead on the immune system in a variety of laboratory animals, but very little has been done in this area with avian species. Such immunosuppressive effects could be of significance to waterfowl populations, considering the potential for lead ingestion by waterfowl and subsequent exposure of these birds to disease agents.

  6. 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.

  7. 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.

  8. 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)

  9. 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.

  10. Childhood lead poisoning.

    PubMed

    Linakis, J G

    1995-01-01

    Lead poisoning has been referred to as the most important environmental health hazard for children in New England. Medical professionals are in a unique position to perform a number of interventions that could make a lasting impact. First, physicians and nurses, particularly in the areas of pediatrics and family medicine, can provide anticipatory guidance to all families with young children. Lead poisoning, in contrast to long held beliefs, is an affliction that affects all socioeconomic groups. Parents should thus be informed regarding sources of lead, including occupational and hobby sources, and basic nutritional and abatement information should be provided. Second, health care workers should encourage lead screening in appropriately aged children at recommended intervals based on known risk factors. Once a blood lead concentration greater than 20[symbol: see text]g/dl has been obtained in a child, treatment or referral to an established lead clinic should be undertaken in a timely fashion. For children with low or moderate lead levels, many pediatricians or family physicians prefer to supervise their patients' treatment, including chelation therapy. For children with higher levels or in instances when the health care professional elects to refer, there are several lead clinics throughout New England whose clinicians are experienced in the treatment of childhood lead poisoning. Finally the medical profession needs to publicly recognize, as child advocates, that lead poisoning is one of the most common pediatric health problems in the United States and that it is entirely preventable. Fortunately, after many years and much hard work, Rhode Island finally has laws that start to deal with the lead problem in an appropriately aggressive fashion.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. 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 ...

  12. Lead toxicity: a review.

    PubMed

    Wani, Ab Latif; Ara, Anjum; Usmani, Jawed Ahmad

    2015-06-01

    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.

  13. 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

  14. 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 ...

  15. 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…

  16. 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.

  17. Bonding aluminum beam leads

    NASA Technical Reports Server (NTRS)

    Burkett, F. S.

    1978-01-01

    Report makes it relatively easy for hybrid-circuit manufacturers to convert integrated circuit chips with aluminum bead leads. Report covers: techniques for handling tiny chips; proper geometries for ultrasonic bonding tips; best combinations of pressure, pulse time, and ultrasonic energy for bonding; and best thickness for metal films to which beam leads are bonded.

  18. 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.

  19. 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 ...

  20. 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.

  1. Inactivation of X-linked tumor suppressor genes in human cancer

    PubMed Central

    Liu, Runhua; Kain, Mandy; Wang, Lizhong

    2015-01-01

    Cancer cells silence autosomal tumor suppressor genes by Knudson’s two-hit mechanism in which loss-of-function mutations and then loss of heterozygosity occur at the tumor suppressor gene loci. However, the identification of X-linked tumor suppressor genes has challenged the traditional theory of “two-hit inactivation” in tumor suppressor genes, introducing the novel concept that a single genetic hit can cause loss of tumor suppressor function. The mechanism through which these genes are silenced in human cancer is unclear, but elucidating the details will greatly enhance our understanding of the pathogenesis of human cancer. Here, we review the identification of X-linked tumor suppressor genes and discuss the potential mechanisms of their inactivation. In addition, we also discuss how the identification of X-linked tumor suppressor genes can potentially lead to new approaches to cancer therapy. PMID:22515449

  2. Inactivation of X-linked tumor suppressor genes in human cancer.

    PubMed

    Liu, Runhua; Kain, Mandy; Wang, Lizhong

    2012-04-01

    Cancer cells silence autosomal tumor suppressor genes by Knudson's two-hit mechanism in which loss-of-function mutations and then loss of heterozygosity occur at the tumor suppressor gene loci. However, the identification of X-linked tumor suppressor genes has challenged the traditional theory of 'two-hit inactivation' in tumor suppressor genes, introducing the novel concept that a single genetic hit can cause loss of tumor suppressor function. The mechanism through which these genes are silenced in human cancer is unclear, but elucidating the details will greatly enhance our understanding of the pathogenesis of human cancer. Here, we review the identification of X-linked tumor suppressor genes and discuss the potential mechanisms of their inactivation. In addition, we also discuss how the identification of X-linked tumor suppressor genes can potentially lead to new approaches in cancer therapy.

  3. 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

  4. 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.

  5. 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.

  6. Linking Economic Strategies and Ontario Colleges

    ERIC Educational Resources Information Center

    Summers, Bill; Drea, Catherine

    2004-01-01

    Ontario's Colleges of Applied Arts and Technology (CAATs) have established productive links with employers and the result is practical training that leads to rewarding work for graduates. This practical success is not being adequately recognized in a crucial debate that focuses on strategies for economic development. It is important for the CAATs…

  7. 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)

  8. Reporter Lead-In

    ERIC Educational Resources Information Center

    Race Relations Reporter, 1974

    1974-01-01

    Includes a report on the link between the Republicans and Chicano radicals, a hard look at Jesse Jackson, a surprise from the Supreme Court, a brief account of a television dispute in New Mexico, a report on renewed gang violence in Los Angeles schools, and a summary of important and revealing events in January and February. (Author/JM)

  9. Group Sparse Additive Models

    PubMed Central

    Yin, Junming; Chen, Xi; Xing, Eric P.

    2016-01-01

    We consider the problem of sparse variable selection in nonparametric additive models, with the prior knowledge of the structure among the covariates to encourage those variables within a group to be selected jointly. Previous works either study the group sparsity in the parametric setting (e.g., group lasso), or address the problem in the nonparametric setting without exploiting the structural information (e.g., sparse additive models). In this paper, we present a new method, called group sparse additive models (GroupSpAM), which can handle group sparsity in additive models. We generalize the ℓ1/ℓ2 norm to Hilbert spaces as the sparsity-inducing penalty in GroupSpAM. Moreover, we derive a novel thresholding condition for identifying the functional sparsity at the group level, and propose an efficient block coordinate descent algorithm for constructing the estimate. We demonstrate by simulation that GroupSpAM substantially outperforms the competing methods in terms of support recovery and prediction accuracy in additive models, and also conduct a comparative experiment on a real breast cancer dataset.

  10. 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.

  11. Impact of bone lead and bone resorption on plasma and whole blood lead levels during pregnancy.

    PubMed

    Téllez-Rojo, Martha María; Hernández-Avila, Mauricio; Lamadrid-Figueroa, Héctor; Smith, Donald; Hernández-Cadena, Leticia; Mercado, Adriana; Aro, Antonio; Schwartz, Joel; Hu, Howard

    2004-10-01

    The authors tested the hypotheses that maternal bone lead burden is associated with increasing maternal whole blood and plasma lead levels over the course of pregnancy and that this association is modified by rates of maternal bone resorption. A total of 193 Mexican women were evaluated (1997-1999) in the first, second, and third trimesters of pregnancy. Whole blood lead and plasma lead levels were measured in each trimester. Urine was analyzed for cross-linked N-telopeptides (NTx) of type I collagen, a biomarker of bone resorption. Patella and tibia lead levels were measured at 4 weeks postpartum. The relation between whole blood, plasma, and bone lead and NTx was assessed using mixed models. Plasma lead concentrations followed a U-shape, while NTx levels increased significantly during pregnancy. In a multivariate model, the authors observed a significant and positive interaction between NTx and bone lead when plasma lead was used as the outcome variable. Dietary calcium intake was inversely associated with plasma lead. Results for whole blood lead were similar but less pronounced. These results confirm previous evidence that bone resorption increases during pregnancy, with a consequential significant release of lead from bone, constituting an endogenous source of prenatal exposure. They also provide a rationale for testing strategies (e.g., nutritional supplementation with calcium) aimed at decreasing prenatal lead exposure.

  12. 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.

  13. Fused Lasso Additive Model

    PubMed Central

    Petersen, Ashley; Witten, Daniela; Simon, Noah

    2016-01-01

    We consider the problem of predicting an outcome variable using p covariates that are measured on n independent observations, in a setting in which additive, flexible, and interpretable fits are desired. We propose the fused lasso additive model (FLAM), in which each additive function is estimated to be piecewise constant with a small number of adaptively-chosen knots. FLAM is the solution to a convex optimization problem, for which a simple algorithm with guaranteed convergence to a global optimum is provided. FLAM is shown to be consistent in high dimensions, and an unbiased estimator of its degrees of freedom is proposed. We evaluate the performance of FLAM in a simulation study and on two data sets. Supplemental materials are available online, and the R package flam is available on CRAN. PMID:28239246

  14. 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 diamines containing phenylethynyl groups and various ratios of phthalic anhydride and 4-phenylethynylphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pyrrolidi none 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.

  15. Latest Research: Genetic Links

    MedlinePlus

    ... Current Issue Past Issues Feature: Vision Latest Research: Genetic Links Past Issues / Summer 2008 Table of Contents ... laboratories is one way the NEI is expanding genetic testing of eye diseases. Photo courtesy of National ...

  16. Additives in plastics.

    PubMed Central

    Deanin, R D

    1975-01-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products. PMID:1175566

  17. Additives in plastics.

    PubMed

    Deanin, R D

    1975-06-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products.

  18. 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 |

  19. Cross-linking of DNA through HMGA1 suggests a DNA scaffold

    PubMed Central

    Vogel, Benjamin; Löschberger, Anna; Sauer, Markus; Hock, Robert

    2011-01-01

    Binding of proteins to DNA is usually considered 1D with one protein bound to one DNA molecule. In principle, proteins with multiple DNA binding domains could also bind to and thereby cross-link different DNA molecules. We have investigated this possibility using high-mobility group A1 (HMGA1) proteins, which are architectural elements of chromatin and are involved in the regulation of multiple DNA-dependent processes. Using direct stochastic optical reconstruction microscopy (dSTORM), we could show that overexpression of HMGA1a-eGFP in Cos-7 cells leads to chromatin aggregation. To investigate if HMGA1a is directly responsible for this chromatin compaction we developed a DNA cross-linking assay. We were able to show for the first time that HMGA1a can cross-link DNA directly. Detailed analysis using point mutated proteins revealed a novel DNA cross-linking domain. Electron microscopy indicates that HMGA1 proteins are able to create DNA loops and supercoils in linearized DNA confirming the cross-linking ability of HMGA1a. This capacity has profound implications for the spatial organization of DNA in the cell nucleus and suggests cross-linking activities for additional nuclear proteins. PMID:21596776

  20. 40 CFR Appendix Xi to Part 266 - Lead-Bearing Materials That May be Processed in Exempt Lead Smelters

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 28 2012-07-01 2012-07-01 false Lead-Bearing Materials That May be... 266—Lead-Bearing Materials That May be Processed in Exempt Lead Smelters A. Exempt Lead-Bearing... Pasting additive bags Asphalt paving materials B. Exempt Lead-Bearing Materials When Generated...

  1. 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...

  2. More Than Additional Space...

    ERIC Educational Resources Information Center

    CEFP Journal, 1973

    1973-01-01

    A much needed addition to the Jamestown Elementary School turned out to be more than an expansion of walls for more space. A new educational program, a limited budget, and a short time line were tackled on a team approach basis and were successfully resolved. (Author)

  3. 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...

  4. American Lead Action Memorandum

    EPA Pesticide Factsheets

    ACTION MEMORANDUM— Request for a Time-Critical Removal Action andExemption from the $2 Million and 12-Month Statutory Limits at the AmericanLead Site, Indianapolis, Marion County, Indiana (Site ID #B56J)

  5. Leading Causes of Blindness

    MedlinePlus

    ... Cataract. Photo courtesy of National Eye Institute, NIH Cataracts Cataracts are a clouding of the lenses in your ... older people. More than 22 million Americans have cataracts. They are the leading cause of blindness in ...

  6. Learn about Lead

    MedlinePlus

    Jump to main content US EPA United States Environmental Protection Agency Search Search Lead Share Facebook Twitter Google+ ... 2 pp, 291 K, About PDF ) The most important step parents, doctors, and others can take is ...

  7. Lead Poisoning Prevention Tips

    MedlinePlus

    ... North Dakota Ohio Oklahoma Oregon Pennsylvania Philadelphia Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont ... up paint debris after work is completed. Create barriers between living/play areas and lead sources. Until ...

  8. Feature Leads That Work.

    ERIC Educational Resources Information Center

    Konkle, Bruce E.

    1999-01-01

    Presents advice to scholastic journalists on writing leads for feature stories. Discusses using a summary, a question, a direct quote, a first-person account, alliteration, a shocking statement, contrast, historical reference, descriptions, narratives, metaphors, and similes. (RS)

  9. 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.

  10. 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%.

  11. Additive-driven assembly of block copolymers

    NASA Astrophysics Data System (ADS)

    Lin, Ying; Daga, Vikram; Anderson, Eric; Watkins, James

    2011-03-01

    One challenge to the formation of well ordered hybrid materials is the incorporation of nanoscale additives including metal, semiconductor and dielectric nanoparticles at high loadings while maintaining strong segregation. Here we describe the molecular and functional design of small molecule and nanoparticle additives that enhance phase segregation in their block copolymer host and enable high additive loadings. Our approach includes the use of hydrogen bond interactions between the functional groups on the additive or particle that serve as hydrogen bond donors and one segment of the block copolymer containing hydrogen bond acceptors. Further, the additives show strong selectively towards the targeted domains, leading to enhancements in contrast between properties of the phases. In addition to structural changes, we explore how large changes in the thermal and mechanical properties occur upon incorporation of the additives. Generalization of this additive-induced ordering strategy to various block copolymers will be discussed.

  12. Reversible Oxidative Addition at Carbon.

    PubMed

    Eichhorn, Antonius F; Fuchs, Sonja; Flock, Marco; Marder, Todd B; Radius, Udo

    2017-04-07

    The reactivity of N-heterocyclic carbenes (NHCs) and cyclic alkyl amino carbenes (cAACs) with arylboronate esters is reported. The reaction with NHCs leads to the reversible formation of thermally stable Lewis acid/base adducts Ar-B(OR)2 ⋅NHC (Add1-Add6). Addition of cAAC(Me) to the catecholboronate esters 4-R-C6 H4 -Bcat (R=Me, OMe) also afforded the adducts 4-R-C6 H4 Bcat⋅cAAC(Me) (Add7, R=Me and Add8, R=OMe), which react further at room temperature to give the cAAC(Me) ring-expanded products RER1 and RER2. The boronate esters Ar-B(OR)2 of pinacol, neopentylglycol, and ethyleneglycol react with cAAC at RT via reversible B-C oxidative addition to the carbene carbon atom to afford cAAC(Me) (B{OR}2 )(Ar) (BCA1-BCA6). NMR studies of cAAC(Me) (Bneop)(4-Me-C6 H4 ) (BCA4) demonstrate the reversible nature of this oxidative addition process.

  13. Lead-210 contamination

    SciTech Connect

    Gray, P.

    1997-12-31

    Nearly all scrap dealers, smelters and other recyclers routinely monitor for radioactivity in shipments entering their facility. These sensitive radiation gate monitors easily detect radium-226 and most other radioactive nuclides. However, the type of detector normally used, sodium iodide scintillation crystals, will not detect the low energy gamma radiation emitted by lead-210 and its progeny. Since lead-210 is a common radioactive contaminant in certain industries, contaminated scrap metal from these industries may avoid detection at the recycler. Lead-210 is a decay product of radon-222 which is produced in small concentrations with natural gas. As the natural gas liquids, particularly ethane and propane, are separated from the natural gas, the radon concentrates in the ethane/propane fraction. The natural gas industry, particularly gas processing facilities and industries using ethane and propane as feed stocks can be significantly contaminated with the radon decay products, especially lead-210, bismuth-210 and polonium-210. Unless the scrap metal is decontaminated before sending to the recycler, the lead-210 contaminated scrap may be processed, resulting in some degree of radioactive contamination of the recycling facilities. Methods of detecting the low energy gamma radiation associated with lead-210 include the pancake G-M detector and the thin crystal-thin window scintillation detector.

  14. 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

  15. 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

  16. Microscale nonreductive release of O-linked glycans for subsequent analysis through MALDI mass spectrometry and capillary electrophoresis.

    PubMed

    Huang, Y; Mechref, Y; Novotny, M V

    2001-12-15

    A new beta-elimination-based procedure has been devised for a microscale release of O-linked oligosaccharides from glycoproteins. Unlike the conventional Carlson degradation, which leads to formation of alditols, the procedure reported here renders the reducing end intact. Conversion of the liberated oligosaccharides to glycosylamines in ammonia medium is followed by the production of the reducing oligosaccharides through the addition of boric acid. The quantitatively generated oligosaccharides with the reducing end can subsequently be derivatized with a fluorophoric reagent for capillary electrophoresis or, alternatively, analyzed through MALDI mass spectrometry. The microscale version of these chemical steps permits us to investigate structurally O-linked oligosaccharides at very low levels.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. New sources add to lead poisoning concerns

    SciTech Connect

    Benevich, T. )

    1990-02-09

    Lead poisoning again is edging to the forefront of medical concerns, spurred by the addition of unusual sources and a growing amount of information about the severity of its consequences. Ingesting or breathing in the lead from paint is till a major cause. Still, the source of lead is not always from paint. Lead can be inhaled from the dust that comes from the clothes, skin, shoes, and cars of people who work in lead-related industries. There also is the relatively new occupation of deleading homes that contain the older lead-based paint as part of building rehabilitation. Effects of lead poisoning are most pronounced in children and fetuses because it can damage the immature central nervous system.

  2. 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...

  3. Siloxane containing addition polyimides

    NASA Technical Reports Server (NTRS)

    Maudgal, S.; St. Clair, T. L.

    1984-01-01

    Addition polyimide oligomers have been synthesized from bis(gamma-aminopropyl) tetramethyldisiloxane and 3, 3', 4, 4'-benzophenonetetracarboxylic dianhydride using a variety of latent crosslinking groups as endcappers. The prepolymers were isolated and characterized for solubility (in amide, chlorinated and ether solvents), melt flow and cure properties. The most promising systems, maleimide and acetylene terminated prepolymers, were selected for detailed study. Graphite cloth reinforced composites were prepared and properties compared with those of graphite/Kerimid 601, a commercially available bismaleimide. Mixtures of the maleimide terminated system with Kerimid 601, in varying proportions, were also studied.

  4. 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.

  5. Pacemaker lead endocarditis

    PubMed Central

    Scheffer, M.; van der Linden, E.; van Mechelen, R.

    2003-01-01

    We present a patient with a pacemaker lead endocarditis who showed no signs of pocket infection but with high fever and signs of infection in the routine laboratory tests. A diagnosis of pacemaker lead endocarditis must be considered in all patients with fever and infection parameters who have a pacemaker inserted, not only in the first weeks after implantation but also late after implantation, as long as no other cause of infection has been found. Transthoracal echocardiography alone is not sensitive enough to establish the correct diagnosis. Transoesophageal echocardiography (TEE) is mandatory to demonstrate the presence or absence of a vegetation on a pacemaker lead. ImagesFigure 1Figure 2Figure 3Figure 4 PMID:25696204

  6. Placental Permeability of Lead

    PubMed Central

    Carpenter, Stanley J.

    1974-01-01

    The detection of lead in fetal tissues by chemical analysis has long been accepted as prima facie evidence for the permeability of the placenta to this nonessential trace metal. However, only a few investigations, all on lower mammalian species, have contributed any direct experimental data bearing on this physiological process. Recent radioactive tracer and radioautographic studies on rodents have shown that lead crosses the placental membranes rapidly and in significant amounts even at relatively low maternal blood levels. While it is not possible to extrapolate directly the results of these experiments to humans because of differences in placental structure and other factors, the results do serve as a warning of the possible hazard to the human embryo and fetus of even low levels of lead in the maternal system. PMID:4857497

  7. Thrombus on pacemaker lead.

    PubMed

    Raut, Monish S; Maheshwari, Arun; Dubey, Sumir

    2015-12-01

    A 58-year-old male was admitted with history of shortness of breath and recurrent fever since two months. He had undergone permanent pacemaker implantation six years back for complete heart block. The patient was persistently having thrombocytopenia. Echocardiographic examination revealed mass (size 4.28 cm(2)) attached to pacemaker lead in right atrium. The patient was scheduled for open-heart surgery for removal of right atrial mass. During surgery, pacemaker leads and pulse generator were also removed along with mass considering the possible source of infection.

  8. Platelet additive solution - electrolytes.

    PubMed

    Azuma, Hiroshi; Hirayama, Junichi; Akino, Mitsuaki; Ikeda, Hisami

    2011-06-01

    Recent attention to solutions that replace most or all plasma in platelet concentrates, while maintaining satisfactory platelet function, is motivated by the potential of plasma reduction or depletion to mitigate various transfusion-related adverse events. This report considers the electrolytic composition of previously described platelet additive solutions, in order to draw general conclusions about what is required for platelet function and longevity. The optimal concentrations of Na(+) and Cl(-) are 69-115 mM. The presence of both K(+) and Mg(2+) in platelet suspension at nearly physiological concentrations (3-5mM and 1.5-3mM, respectively) is indispensable for good preservation capacity because both electrolytes are required to prevent platelet activation. In contrast to K(+) and Mg(2+), Ca(2+) may not be important because no free Ca(2+) is available in M-sol, which showed excellent platelet preservation capacity at less than 5% plasma concentration. The importance of bicarbonate (approximately 40 mM) can be recognized when the platelets are suspended in additive solution under less than 5% residual plasma concentration.

  9. Renewable Fuel Standard Program (RFS1): Final Rule Additional Resources

    EPA Pesticide Factsheets

    The final rule of fuels and fuel additives: renewable fuel standard program is published on May 1, 2007 and is effective on September 1, 2007. You will find the links to this final rule and technical amendments supporting this rule.

  10. Renewable Fuel Standard (RFS2): Final Rule Additional Resources

    EPA Pesticide Factsheets

    The final rule of fuels and fuel additives: renewable fuel standard program is published on March 26, 2010 and is effective on July 1, 2010. You will find the links to this final rule and technical amendments supporting this rule.

  11. Broadcasting satellite feeder links - Characteristics and planning

    NASA Technical Reports Server (NTRS)

    Kiebler, J. W.

    1982-01-01

    The paper presents the results of recent studies by the Feeder Link Sub-Working Group of the FCC Advisory Committee for the 1983 Regional Administrative Radio Conference (RARC). These studies conclude that specification of a few key parameters will make feeder link planning relatively straightforward. Feeder links can be located anywhere within a country if satellite orbit locations are separated by 10 deg for adjacent service areas and key parameter values presented in the paper are adopted. Colocated satellites serving a common service area need special attention to attain sufficient isolation between a desired channel and its adjacent cross-polarized channels and alternate co-polarized channels. In addition to presenting planning conclusions by the Advisory Committee, the paper presents and analyzes actions of the International Radio Consultative Committee's Conference Planning Meeting (CPM) concerning feeder links. The CPM reached conclusions similar to, and compatible with, those of the Advisory Committee.

  12. 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…

  13. 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…

  14. Beam lead forming tool

    NASA Technical Reports Server (NTRS)

    Clemons, P. W.

    1973-01-01

    Tool was designed for table-top manual operation that can bend leads to any desired angle up to 90 degrees. It can be readily adapted to electrical, hydraulic, or pneumatic operation. This innovation may be of interest to electronics, sheet metal, and appliance industries.

  15. 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.

  16. 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…

  17. 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

  18. 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...

  19. Additive composition, for gasoline

    SciTech Connect

    Vataru, M.

    1989-01-10

    An admixture is described that comprises Diesel fuel and an additive composition added thereto which is between about 0.05 to about 2.0 percent by weight of the fuel, the composition comprising: (a) between about 0.05 and 25% relative weight parts of an organic peroxide, and (b) between about 0.1 and 25% relative weight parts of detergent selected from the component group that consists of: (i) fatty amines; (ii) ethoxylated and propoxylated derivatives of fatty amines; (iii) fatty diamines; (iv) fatty imidazlines; (v) polymeric amines and derivatives thereof; (vi) combination of one or more of the (i) through (v) components with carboxylic acid or acids having from three to forth carbon atoms, (c) from about 99.0 to about 50% by weight of a hydrocarbon solvent.

  20. Teardrop bladder: additional considerations

    SciTech Connect

    Wechsler, R.J.; Brennan, R.E.

    1982-07-01

    Nine cases of teardrop bladder (TDB) seen at excretory urography are presented. In some of these patients, the iliopsoas muscles were at the upper limit of normal in size, and additional evaluation of the perivesical structures with computed tomography (CT) was necessary. CT demonstrated only hypertrophied muscles with or without perivesical fat. The psoas muscles and pelvic width were measured in 8 patients and compared with the measurements of a control group of males without TDB. Patients with TDB had large iliopsoas muscles and narrow pelves compared with the control group. The psoas muscle width/pelvic width ratio was significantly greater (p < 0.0005) in patients with TDB than in the control group, with values of 1.04 + 0.05 and 0.82 + 0.09, respectively. It is concluded that TDB is not an uncommon normal variant in black males. Both iliopsoas muscle hypertrophy and a narrow pelvis are factors that predispose a patient to TDB.

  1. New addition curing polyimides

    NASA Technical Reports Server (NTRS)

    Frimer, Aryeh A.; Cavano, Paul

    1991-01-01

    In an attempt to improve the thermal-oxidative stability (TOS) of PMR-type polymers, the use of 1,4-phenylenebis (phenylmaleic anhydride) PPMA, was evaluated. Two series of nadic end-capped addition curing polyimides were prepared by imidizing PPMA with either 4,4'-methylene dianiline or p-phenylenediamine. The first resulted in improved solubility and increased resin flow while the latter yielded a compression molded neat resin sample with a T(sub g) of 408 C, close to 70 C higher than PME-15. The performance of these materials in long term weight loss studies was below that of PMR-15, independent of post-cure conditions. These results can be rationalized in terms of the thermal lability of the pendant phenyl groups and the incomplete imidization of the sterically congested PPMA. The preparation of model compounds as well as future research directions are discussed.

  2. 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.

  3. 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.

  4. Photoinduced Plasticity in Cross-Linked Liquid Crystalline Networks.

    PubMed

    McBride, Matthew K; Hendrikx, Matthew; Liu, Danqing; Worrell, Brady T; Broer, Dirk J; Bowman, Christopher N

    2017-02-24

    Photoactivated reversible addition fragmentation chain transfer (RAFT)-based dynamic covalent chemistry is incorporated into liquid crystalline networks (LCNs) to facilitate spatiotemporal control of alignment, domain structure, and birefringence. The RAFT-based bond exchange process, which leads to stress relaxation, is used in a variety of conditions, to enable the LCN to achieve a near-equilibrium structure and orientation upon irradiation. Once formed, and in the absence of subsequent triggering of the RAFT process, the (dis)order in the LCN and its associated birefringence are evidenced at all temperatures. Using this approach, the birefringence, including the formation of spatially patterned birefringent elements and surface-active topographical features, is selectively tuned by adjusting the light dose, temperature, and cross-linking density.

  5. 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). ...

  6. Link Influence Entropy

    NASA Astrophysics Data System (ADS)

    Singh, Priti; Chakraborty, Abhishek; Manoj, B. S.

    2017-01-01

    In this paper we propose a new metric, Link Influence Entropy (LInE), which describes importance of each node based on the influence of each link present in a network. Influence of a link can neither be effectively estimated using betweenness centrality nor using degree based probability measures. The proposed LInE metric which provides an effective way to estimate the influence of a link in the network and incorporates this influence to identify nodal characteristics, performs better compared to degree based entropy. We found that LInE can differentiate various network types which degree-based or betweenness centrality based node influence metrics cannot. Our findings show that spatial wireless networks and regular grid networks, respectively, have lowest and highest LInE values. Finally, performance analysis of LInE is carried out on a real-world network as well as on a wireless mesh network testbed to study the influence of our metric as well as influence stability of nodes in dynamic networks.

  7. TWSTFT Link Calibration Report

    DTIC Science & Technology

    2015-09-01

    Serrano, G. Brunetti (2013) Relative Calibration of the Time Transfer Link between CERN and LNGS for Precise Neutrino Time of Flight Measurements. Proc...Esteban, M. Pallavicini, Va. Pettiti, C. Plantard, A. Razeto (2012) Measurement of CNGS Muon Neutrinos Speed with Borexino: INRIM and ROA Contribution

  8. 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…

  9. CERES Web Links

    Atmospheric Science Data Center

    2013-03-21

        Web Links to Relevant CERES Information Relevant information about ... questions about the CERES data can be found at the following web sites: CERES Home Page CERES TRMM Home Page ... Information page  on the Atmospheric Science Data Center site CERES "ARM" Validation Experiment (CAVE) Home Page  has ...

  10. 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.

  11. Neural alterations from lead exposure in zebrafish.

    PubMed

    Roy, Nicole M; DeWolf, Sarah; Schutt, Alexius; Wright, Ashia; Steele, Latina

    2014-01-01

    Lead was used extensively as a gas additive and pesticide, in paints, batteries, lead shot, pipes, canning and toy manufacturing. Although uses of lead have been restricted, lead persists in our environment especially in older homes, and generally in soil and water. Although extensive studies have determined that fetal and childhood exposures to lead have been associated with childhood and adolescent memory impairments and learning disabilities, there are limited studies investigating early neural and morphological effects that may lead to these behavioral and learning abnormalities. Here we utilize the zebrafish vertebrate model system to study early effects of lead exposure on the brain. We treat embryos with 0.2mM lead for 24, 48 and 72 h and analyze neural structures through live imagery and transgenic approaches. We find structural abnormalities in the hindbrain region as well as changes in branchiomotor neuron development and altered neural vasculature. Additionally, we find areas of increased apoptosis. We conclude that lead is developmentally neurotoxic to a specific region of the brain, the hindbrain and is toxic to branchiomotor neurons residing in rhombomeres 2 through 7 of the hindbrain and hindbrain central artery vasculature.

  12. 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

  13. 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

  14. 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…

  15. Mortality of lead smelter workers

    SciTech Connect

    Selevan, S.G.; Landrigan, P.J.; Stern, F.B.; Jones, J.H.

    1985-10-01

    To examine patterns of death in lead smelter workers, a retrospective analysis of mortality was conducted in a cohort of 1,987 males employed between 1940 and 1965 at a primary lead smelter in Idaho. Overall mortality was similar to that of the United States white male population (standardized mortality ratio (SMR) = 98). Excess mortality, however, was found from chronic renal disease (SMR = 192; confidence interval (CI) = 88-364), and the risk of death from renal disease increased with increasing duration of employment, such that after 20 years employment, the standardized mortality ratio reached 392 (CI = 107-1,004). Excess mortality was also noted for nonmalignant respiratory disease (SMR = 187, CI = 128-264). Eight of 32 deaths in this category were caused by silicosis; at least five workers who died of silicosis had been miners for a part of their lives. An additional 11 deaths resulted from tuberculosis (SMR = 139; CI = 69-249); in six of these cases, silicosis was a contributory cause of death. Cancer mortality was not increased overall (SMR = 95; CI = 78-114). An increase, however, was noted for deaths from kidney cancer (six cases; SMR = 204; CI = 75-444). Finally, excess mortality was noted for injuries (SMR = 138; CI = 104-179); 13 (23%) of the 56 deaths in this category were caused by mining injuries. The data from this study are consistent with previous reports of increased mortality from chronic renal disease in persons exposed occupationally to lead.

  16. Lead poisoning: The invisible disease

    USGS Publications Warehouse

    Friend, Milton

    1989-01-01

    Lead poisoning is an intoxication resulting from absorption of hazardous levels of lead into body tissues. Lead pellets from shot shells, when ingested, are the most common source of lead poisoning in migratory birds. Other far less common sources include lead fishing sinkers, mine wastes, paint pigments, bullets, and other lead objects that are swallowed.

  17. Additive lattice kirigami.

    PubMed

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

    2016-09-01

    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.

  18. Ceramics with Different Additives

    NASA Astrophysics Data System (ADS)

    Wang, Juanjuan; Feng, Lajun; Lei, Ali; Zhao, Kang; Yan, Aijun

    2014-09-01

    Li2CO3, MgCO3, BaCO3, and Bi2O3 dopants were introduced into CaCu3Ti4O12 (CCTO) ceramics in order to improve the dielectric properties. The CCTO ceramics were prepared by conventional solid-state reaction method. The phase structure, microstructure, and dielectric behavior were carefully investigated. The pure structure without any impurity phases can be confirmed by the x-ray diffraction patterns. Scanning Electron Microscopy (SEM) analysis illuminated that the grains of Ca0.90Li0.20Cu3Ti4O12 ceramics were greater than that of pure CCTO. It was important for the properties of the CCTO ceramics to study the additives in complex impedance spectroscopy. It was found that the Ca0.90Li0.20Cu3Ti4O12 ceramics had the higher permittivity (>45000), the lower dielectric loss (<0.025) than those of CCTO at 1 kHz at room temperature and good temperature stability from -30 to 75 °C.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. Optimal search strategies on complex multi-linked networks

    PubMed Central

    Di Patti, Francesca; Fanelli, Duccio; Piazza, Francesco

    2015-01-01

    In this paper we consider the problem of optimal search strategies on multi-linked networks, i.e. graphs whose nodes are endowed with several independent sets of links. We focus preliminarily on agents randomly hopping along the links of a graph, with the additional possibility of performing non-local hops to randomly chosen nodes with a given probability. We show that an optimal combination of the two jump rules exists that maximises the efficiency of target search, the optimum reflecting the topology of the network. We then generalize our results to multi-linked networks with an arbitrary number of mutually interfering link sets. PMID:25950716

  4. A note on deep space optical communication link parameters

    NASA Technical Reports Server (NTRS)

    Dolinar, S. J.; Yuen, J. H.

    1982-01-01

    Topical communication in the context of a deep space communication link. Communication link analysis at the optical frequencies differs significantly from that at microwave frequencies such as the traditional S and X-bands used in deep space applications, due to the different technology of transmitter, antenna, modulators, and receivers. In addition, the important role of quantum noise in limiting system performance is quite different than that of thermal noise. The optical link design is put in a design control table format similar to a microwave telecom link design. Key considerations unique to the optical link are discussed.

  5. Flexible Data Link

    DTIC Science & Technology

    2015-04-01

    continuously-interleaved Reed- Solomon scheme with 8% overhead has the best trade-off of performance (net coding gain) and overhead. Therefore, this is...disparity between attenuation at sea level versus at a 9150 meter altitude. As the Flexible Data Link system is an airborne asset which may operate...Quadrature Amplitude Modulation QPSK Quadrature Phase Shift Key RF Radio Frequency RS Reed- Solomon S&E Scientist & Engineers SFP Small Form-factor

  6. Electrospun cross linked rosin fibers

    NASA Astrophysics Data System (ADS)

    Baek, Woo-il; Nirmala, R.; Barakat, Nasser A. M.; El-Newehy, Mohamed H.; Al-Deyab, Salem S.; Kim, Hak Yong

    2011-12-01

    In this study, we describe the first reported preparation of rosin in fiber form through use of an electrospinning technique utilizing various solvent systems. The polymer concentration of the formed fiber was studied by using various solvents such as chloroform, ethanol, N-N dimethylformamide (DMF), tetrahydrofuran (THF), acetone, and methylene chloride (MC). An electrospray of the solution resulted in the beaded form of the rosin. By varying the polymer concentration with MC, we were then able to obtain uniform fibers. However, the fibers exhibited large diameter. We believe that it is possible to reduce the diameter of the rosin fibers through appropriate selection of electrospinning parameters. In addition, the morphological transitions from beads, to beaded fiber, to fiber were studied at different polymer concentrations. We propose a possible physical cross linking mechanism for the formation of rosin fibers during the electrospinning process. Our results demonstrate the feasibility of producing fiber nanostructures of rosin by using an electrospinning technique.

  7. 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.

  8. Cross-linking chemistry of squid beak.

    PubMed

    Miserez, Ali; Rubin, Daniel; Waite, J Herbert

    2010-12-03

    In stark contrast to most aggressive predators, Dosidicus gigas (jumbo squids) do not use minerals in their powerful mouthparts known as beaks. Their beaks instead consist of a highly sclerotized chitinous composite with incremental hydration from the tip to the base. We previously reported l-3,4-dihydroxyphenylalanine (dopa)-histidine (dopa-His) as an important covalent cross-link providing mechanical strengthening to the beak material. Here, we present a more complete characterization of the sclerotization chemistry and describe additional cross-links from D. gigas beak. All cross-links presented in this report share common building blocks, a family of di-, tri-, and tetra-histidine-catecholic adducts, that were separated by affinity chromatography and high performance liquid chromatography (HPLC) and identified by tandem mass spectroscopy and proton nuclear magnetic resonance ((1)H NMR). The data provide additional insights into the unusually high cross-link density found in mature beaks. Furthermore, we propose both a low molecular weight catechol, and peptidyl-dopa, to be sclerotization agents of squid beak. This appears to represent a new strategy for forming hard tissue in animals. The interplay between covalent cross-linking and dehydration on the graded properties of the beaks is discussed.

  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.

  10. 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

  11. Elevated blood lead in a population near a lead smelter in Kosovo, Yugoslavia

    SciTech Connect

    Popovac, D.; Graziano, J.; Seaman, C.

    1982-01-01

    A survey of residents of a community surrounding a lead smelter has revealed an alarming incidence of elevated blood lead and erythrocyte protoporphyrin concentrations. In particular, children who were less than 3 yr of age were severely affected. Of those children tested in December, 1980, 35% had blood lead concentrations between 50-69 ..mu..u/dl, while an additional 12% had concentrations greater than or equal to 70 ..mu..u/dl, and are therefore, at risk for severe neurological sequelae.

  12. DNA interstrand cross-linking by epichlorohydrin.

    PubMed

    Romano, Keith P; Newman, Adam G; Zahran, Rami W; Millard, Julie T

    2007-05-01

    Epichlorohydrin (ECH), an important industrial chemical, is a bifunctional alkylating agent with the potential to form DNA cross-links. Occupational exposure to this suspect carcinogen leads to chromosomal aberrations, and ECH has been shown previously to undergo reaction with DNA in vivo and in vitro. We used denaturing polyacrylamide gel electrophoresis to monitor the possible formation of interstrand cross-links within DNA oligomers by ECH and the related compound, epibromohydrin (EBH). Although both compounds did indeed form cross-links between deoxyguanosine residues, EBH was a more efficient cross-linker than ECH. The optimal pH for cross-linking also varied, with ECH more efficient at pH 5.0 and EBH more efficient at pH 7.0. Both agents were relatively flexible in the sequences targeted, with comparable efficiencies for 5'-GGC and 5'GC sites. Furthermore, interstrand cross-linking by the two optical isomers of ECH correlated with their relative cytotoxicities, with R-ECH about twice as potent as S-ECH.

  13. Drug Response Prediction as a Link Prediction Problem

    PubMed Central

    Stanfield, Zachary; Coşkun, Mustafa; Koyutürk, Mehmet

    2017-01-01

    Drug response prediction is a well-studied problem in which the molecular profile of a given sample is used to predict the effect of a given drug on that sample. Effective solutions to this problem hold the key for precision medicine. In cancer research, genomic data from cell lines are often utilized as features to develop machine learning models predictive of drug response. Molecular networks provide a functional context for the integration of genomic features, thereby resulting in robust and reproducible predictive models. However, inclusion of network data increases dimensionality and poses additional challenges for common machine learning tasks. To overcome these challenges, we here formulate drug response prediction as a link prediction problem. For this purpose, we represent drug response data for a large cohort of cell lines as a heterogeneous network. Using this network, we compute “network profiles” for cell lines and drugs. We then use the associations between these profiles to predict links between drugs and cell lines. Through leave-one-out cross validation and cross-classification on independent datasets, we show that this approach leads to accurate and reproducible classification of sensitive and resistant cell line-drug pairs, with 85% accuracy. We also examine the biological relevance of the network profiles. PMID:28067293

  14. Epstein–Barr Virus: Diseases Linked to Infection and Transformation

    PubMed Central

    Jha, Hem C.; Pei, Yonggang; Robertson, Erle S.

    2016-01-01

    Epstein–Barr virus (EBV) was first discovered in 1964, and was the first known human tumor virus now shown to be associated with a vast number of human diseases. Numerous studies have been conducted to understand infection, propagation, and transformation in various cell types linked to human diseases. However, a comprehensive lens through which virus infection, reactivation and transformation of infected host cells can be visualized is yet to be formally established and will need much further investigation. Several human cell types infected by EBV have been linked to associated diseases. However, whether these are a direct result of EBV infection or indirectly due to contributions by additional infectious agents will need to be fully investigated. Therefore, a thorough examination of infection, reactivation, and cell transformation induced by EBV will provide a more detailed view of its contributions that drive pathogenesis. This undoubtedly expand our knowledge of the biology of EBV infection and the signaling activities of targeted cellular factors dysregulated on infection. Furthermore, these insights may lead to identification of therapeutic targets and agents for clinical interventions. Here, we review the spectrum of EBV-associated diseases, the role of the encoded latent antigens, and the switch to latency or lytic replication which occurs in EBV infected cells. Furthermore, we describe the cellular processes and critical factors which contribute to cell transformation. We also describe the fate of B-cells and epithelial cells after EBV infection and the expected consequences which contribute to establishment of viral-associated pathologies. PMID:27826287

  15. A Millimeter-Wave Digital Link for Wireless MRI.

    PubMed

    Aggarwal, Kamal; Joshi, Kiran R; Rajavi, Yashar; Taghivand, Mazhareddin; Pauly, John M; Poon, Ada S Y; Scott, Greig

    2017-02-01

    A millimeter (mm) wave radio is presented in this work to support wireless MRI data transmission. High path loss and availability of wide bandwidth make mm-waves an ideal candidate for short range, high data rata communication required for wireless MRI. The proposed system uses a custom designed integrated chip (IC) mm-wave radio with 60 GHz as radio frequency carrier. In this work, we assess performance in a 1.5 T MRI field, with the addition of optical links between the console room and magnet. The system uses ON-OFF keying (OOK) modulation for data transmission and supports data rates from 200 Mb/s to 2.5 Gb/s for distances up-to 65 cm. The presence of highly directional, linearly polarized, on-chip dipole antennas on the mm-wave radio along with the time division multiplexing (TDM) circuitry allows multiple wireless links to be created simultaneously with minimal inter-channel interference. This leads to a highly scalable solution for wireless MRI.

  16. 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.

  17. 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.

  18. Microdosing in early lead discovery.

    PubMed

    Jekunen, A P; Pauwels, E K J; Kairemo, K J A

    2010-03-01

    Microdosing provides a tool to enhance drug development by initiating human studies prior to Phase I studies. The purpose is to assist in the go versus no-go decision-making process and to eliminate early ineffective compounds from the drug pipeline. Selection of multiple potential leads can be performed at the clinical stage instead of in preclinical studies. The microdosing approach can be easily used for a molecularly targeted potential drug compound with a known mechanism of action. It provides useful data regarding accessibility and biodistribution that can be used in many estimations benefiting the development of the molecule. In addition, steady state and genetic investigations are becoming possible. Microdosing has a sparing effect on timelines and costs, however, the real importance is not yet known because, although it is known to be widely performed, only a few original reports have been published.

  19. 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.

  20. 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.

  1. Pb neurotoxicity: neuropsychological effects of lead toxicity.

    PubMed

    Mason, Lisa H; Harp, Jordan P; Han, Dong Y

    2014-01-01

    Neurotoxicity is a term used to describe neurophysiological changes caused by exposure to toxic agents. Such exposure can result in neurocognitive symptoms and/or psychiatric disturbances. Common toxic agents include heavy metals, drugs, organophosphates, bacterial, and animal neurotoxins. Among heavy metal exposures, lead exposure is one of the most common exposures that can lead to significant neuropsychological and functional decline in humans. In this review, neurotoxic lead exposure's pathophysiology, etiology, and epidemiology are explored. In addition, commonly associated neuropsychological difficulties in intelligence, memory, executive functioning, attention, processing speed, language, visuospatial skills, motor skills, and affect/mood are explored.

  2. 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.

  3. 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.

  4. Who will lead?

    PubMed

    Gustafson, R P; Schlosser, J R

    1997-01-01

    A recent survey conducted by the UCLA Center for Health Services Management and the Physician Executive Practice of Heidrick & Struggles, an executive search firm, sheds light on the emerging physician executive's role. The goal of the research was to identify success factors as a means of evaluating and developing effective industry leaders. Respondents were asked to look at specific skills in relation to nine categories: Communication, leadership, interpersonal skills, self-motivation/management, organizational knowledge, organizational strategy, administrative skills, and thinking. Communication, leadership, and self-motivation/management emerged, in that order, as the three most important success factors for physician executives. An individual's general competencies, work styles, and ability to lead others through organizational restructuring defines his or her appropriateness for managerial positions in the health care industry.

  5. 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) ...

  6. Antiferroelectricity in lead zirconate

    NASA Astrophysics Data System (ADS)

    Tagantsev, Alexander K.

    2014-03-01

    Antiferroelectrics are essential ingredients for widely applied piezoelectric and ferroelectric materials. Despite their technological importance, the reason why materials become antiferroelectric has remained allusive since their first discovery. Experimentally, antiferroelectrics can be recognized as materials that exhibit a structural phase transition between two non-polar phases with a strong dielectric anomaly at the high temperature side of the transition. Despite a widely spread opinion that these materials can be viewed as direct analogues of antiferromagnetics, the so-called anti-polar ionic displacements at the transition do not guaranty the antiferroelectric behavior of the material while the interpretation of such behavior does not require the incorporation of the anti-polar ionic displacements in the scenario. To get insight in the true origin of antiferroelectricity, we studied the lattice dynamics of the antiferroelectric lead zirconate using inelastic and diffuse X-ray scattering techniques and the Brillouin light scattering. Based on our experimental data, we showed that the driving force for antiferroelectricity is a ferroelectric instability. Through flexoelectric coupling, it drives the system to a state, which is virtually unstable against incommensurate modulations. However, the Umklapp interaction allows the system to go directly to the commensurate lock-in phase, leaving the incommensurate phase as a ``missed'' opportunity. By this mechanism the ferroelectric softening is transformed into an antiferroelectric transition. The remaining key parts of the whole scenario are repulsive and attractive biquadratic couplings that suppress the appearance of the spontaneous polarization and induce the anti-phase octahedral rotations in the low-temperature phase. The analysis of the results reveals that the antiferroelectric state is a ``missed'' incommensurate phase, and that the paraelectric to antiferroelectric phase transition is driven by the

  7. 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.

  8. Bioavailability of Lead in Small Arms Range Soils

    DTIC Science & Technology

    2007-09-01

    speciation analysis showed that lead in these eight soils existed predominantly as lead carbonate or oxide, compounds with known high bioavailability...eight soils existed predominantly as lead carbonate or oxide, compounds with known high bioavailability. An additional 20 small arms range soils from...has generated oxidized forms of Pb, such as lead carbonate or lead oxide, which are then bound to, or sequestered by, soil particles. All three

  9. Lead exposure and behavioral changes: comparisons of four occupational groups with different levels of lead absorption.

    PubMed

    Valciukas, J A; Lilis, R; Singer, R; Fischbein, A; Anderson, H A; Glickman, L

    1980-01-01

    The association between lead absorption and objective psychological performance tests in five groups with different levels of lead absorption was studied in the following groups: (1) a control, non-lead-exposed group; (2) cable splicers, (3) cable manufactures, and (4) secondary lead smelter workers. The following performance tests were used: Block Design, Digit Symbol, and Embedded Figures. Age-corrected performance test scores and the average of three test scores (INDEX) were used throughout. A significant association between performance tests scores and increased lead absorption was found. Zinc protoporphyrin level was a more "powerful" (in the statistical sense) indicator of lead-induced CNS effects than blood lead levels. This study provides additional evidence that neurotoxic effects associated with occupational exposure to lead can be demonstrated by means of performance tests. It has been known and widely accepted that increased lead absorption is associated with "non-specific" subjective symptoms: tiredness, sleep disturbance, irritability, etc. Psychometric techniques (including an appropriate statistical analysis strategy) are highly sensitive for the early detection of CNS neurotoxicity, such as metal toxicity. Moreover, even in lead-exposed but asymptomatic individuals, a significant correlation (negative) between test scores and levels of lead absorption could be detected. It is concluded that workers exposed to lead at levels considered "safe" might be at risk of developing brain dysfunction with long term exposure.

  10. 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.

  11. 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.

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

    PubMed

    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.

  13. 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.

  14. 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.

  15. Drugs + HIV, Learn the Link

    MedlinePlus Videos and Cool Tools

    ... the Link - Drugs and HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 –Ongoing Behaviors ... GA: CDC, DHHS. Retrieved June 2012 How are Drug Abuse and HIV Related? Drug abuse and addiction ...

  16. Lead absorption in cows: biological indicators of ambient lead exposure

    SciTech Connect

    Karacic, V.; Prpic-Majic, D.; Skender, L.

    1984-03-01

    In order to determine actual lead exposure from residual amounts of lead in the environmental soil following the introduction of effective engineering emission controls in a lead smeltery, the absorption of lead in cows grazing in the vicinity was investigated. Four groups of cows were examined: two groups of cows exposed to different ambient lead concentration, compared with two normal groups of cows. In each cow aminolevulinic acid dehydratase (ALAD), erythrocyte protoporphyrin (EP) and blood lead (Pb-B) were determined, two years prior to and four years after the technical sanitation of the lead emission source. The results demonstrated normalization of ALAD, EP and Pb-B after the technical sanitation. In spite of normalization, biological indicators ALAD and Pb-B determined four years after the technical sanitation showed increased lead absorption in comparison with the results of the control group. This indirectly indicates lead contamination of the environment from residual amounts of lead in the soil.

  17. Europa's Leading Hemisphere

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image of Europa's leading hemisphere was obtained by the solid state imaging (CCD) system on board NASA's Galileo spacecraft during its seventh orbit of Jupiter. In the upper left part of the image is Tyre, a multi-ringed structure that may have formed as a result of an ancient impact. Also visible are numerous lineaments that extend for over 1000 kilometers. The limb, or edge, of Europa in this image can be used by scientists to constrain the radius and shape of the satellite. North is to the top of the picture and the sun illuminates the surface from the right. The image, centered at -40 latitude and 180 longitude, covers an area approximately 2000 by 1300 kilometers. The finest details that can be discerned in this picture are about 6.6 kilometers across. The images were taken on April 3, 1997 at 17 hours, 42 minutes, 19 seconds Universal Time when the spacecraft was at a range of 31,8628 kilometers.

    The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  18. 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

  19. Link Analysis for Space Communication Links Using ARQ Protocol

    NASA Technical Reports Server (NTRS)

    Cheung, Kar-Ming; Lau, Chi-Wung; Lee, Charles

    2014-01-01

    In space communications, standard link analysis assumes that messages are sent once. For a communication link that uses an error-correction coding scheme, bit-error-rate (BER) or frame-error-rate (FER), and link margins are common metrics that characterize the quality of a link, and they are used to determine the supportable data rate. With the advent of Automatic Repeat-reQuest (ARQ) protocols, when messages are corrupted during transmission, they can be resent multiple times automatically until they are correctly received and acknowledged. The concept of BER, FER, and link margin cannot be directly applied, and the link analysis approach for ARQ links needs to be re-examined.

  20. 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.

  1. 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.

  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. Electrocardiographic systems with reduced numbers of leads-synthesis of the 12-lead ECG.

    PubMed

    Tomašić, Ivan; Trobec, Roman

    2014-01-01

    Systems with reduced numbers of leads that can synthesize the 12-lead electrocardiogram (ECG) with an insignificant or a small loss of diagnostic information have been proposed. The advantage over standard 12-lead ECG systems is the smaller number of measurement sites (i.e., electrodes) and, consequently, fewer wires. In this paper, we review all the important systems with reduced numbers of leads together with the methodology for synthesizing the leads. The fundamental theoretical background necessary to understand the most important concepts related to the synthesis is included. The presented theoretical and experimental justifications for the synthesis show that it is not necessary to measure a large number of leads directly, because the standard 12-lead ECG and arbitrary additional leads can be synthesized. Various approaches to evaluating the synthesized 12-lead ECG are defined and explained, and a number of systems that synthesize 12-lead ECG are presented as they were introduced in the literature. We cover the developments and improvements from the 1940s to the present day. The systems are classified on the basis of the synthesis method used, the approach to the evaluation of the synthesized ECG (depending on the measurement sites used), and on the number and types of leads employed. Based on a detailed assessment of state-of-the-art systems, open problems and challenges are highlighted, while further developments of electrocardiographic systems are envisaged.

  4. 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...

  5. 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. *

  6. Kojak: Efficient analysis of chemically cross-linked protein complexes

    PubMed Central

    Hoopmann, Michael R.; Zelter, Alex; Johnson, Richard S.; Riffle, Michael; MacCoss, Michael J.; Davis, Trisha N.; Moritz, Robert L.

    2015-01-01

    Protein chemical cross-linking and mass spectrometry enable the analysis of protein-protein interactions and protein topologies, however complicated cross-linked peptide spectra require specialized algorithms to identify interacting sites. The Kojak cross-linking software application is a new, efficient approach to identify cross-linked peptides, enabling large-scale analysis of protein-protein interactions by chemical cross-linking techniques. The algorithm integrates spectral processing and scoring schemes adopted from traditional database search algorithms, and can identify cross-linked peptides using many different chemical cross-linkers, with or without heavy isotope labels. Kojak was used to analyze both novel and existing datasets, and was compared with existing cross-linking algorithms. The algorithm provided increased cross-link identifications over existing algorithms, and equally importantly, the results in a fraction of computational time. The Kojak algorithm is open-source, cross-platform, and freely available. This software provides both existing and new cross-linking researchers alike an effective way to derive additional cross-link identifications from new or existing datasets. For new users, it provides a simple analytical resource resulting in more cross-link identifications than other methods. PMID:25812159

  7. Leading clever people.

    PubMed

    Goffee, Rob; Jones, Gareth

    2007-03-01

    In an economy driven by ideas and intellectual know-how, top executives recognize the importance of employing smart, highly creative people. But if clever people have one defining characteristic, it's that they do not want to be led. So what is a leader to do? The authors conducted more than 100 interviews with leaders and their clever people at major organizations such as PricewaterhouseCoopers, Cisco Systems, Novartis, the BBC, and Roche. What they learned is that the psychological relationships effective leaders have with their clever people are very different from the ones they have with traditional followers. Those relationships can be shaped by seven characteristics that clever people share: They know their worth--and they know you have to employ them if you want their tacit skills. They are organizationally savvy and will seek the company context in which their interests are most generously funded. They ignore corporate hierarchy; although intellectual status is important to them, you can't lure them with promotions. They expect instant access to top management, and if they don't get it, they may think the organization doesn't take their work seriously. They are plugged into highly developed knowledge networks, which both increases their value and makes them more of a flight risk. They have a low boredom threshold, so you have to keep them challenged and committed. They won't thank you--even when you're leading them well. The trick is to act like a benevolent guardian: to grant them the respect and recognition they demand, protect them from organizational rules and politics, and give them room to pursue private efforts and even to fail. The payoff will be a flourishing crop of creative minds that will enrich your whole organization.

  8. Materials science. Electronics without lead.

    PubMed

    Li, Yi; Moon, Kyoung-sik; Wong, C P

    2005-06-03

    In conventional consumer electronics such as cell phones, lead-containing interconnects provide the conductive path between different circuit elements. Environmental concerns have led to a search for lead-free alternatives. In their Perspective, Li et al. review these efforts, which have focused on lead-free alloys and electrically conductive adhesives. Both of these approaches are showing promise, but no one lead-free interconnect material can serve as a substitute for the conventional tin-lead solder in all devices.

  9. 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.

  10. Synthesis and characterization of the dimercury(I)-linked compound [PPn]4[(Re7C(CO)21Hg)2]. Oxidative cleavage of the mercury-mercury bond leading to carbidoheptarhenate complexes of mercury(II), including [PPN][Re7C(CO)21Hg(S=C(NME2)2)].

    PubMed

    Wright, C A; Brand, U; Shapley, J R

    2001-09-10

    The reaction of [PPN](3)[Re(7)C(CO)(21)] with Hg(2)(NO(3))(2).2H(2)O in dichloromethane formed the complex [PPN](4)[(Re(7)C(CO)(21)Hg)(2)] ([PPN](4)[1]), isolated in 60% yield. Analogous salts of [1](4-) with [PPh(4)](+) and [NEt(4)](+) were also prepared. The crystal structure of [PPN](4)[1] showed that two carbidoheptarhenate cores are linked by a dimercury(I) unit (d(Hg-Hg) = 2.610(4) A), with each individual mercury atom face-bridging. Oxidative cleavage of the Hg-Hg bond in [1](4-) was effected by 4-bromophenyl disulfide to form [Re(7)C(CO)(21)HgSC(6)H(4)Br](2-) ([4](2-)), by I(2) to form [Re(7)C(CO)(21)HgI](2-) ([5](2-)), and by Br(2) to form [Re(7)C(CO)(21)HgBr](2-) ([6](2-)). Oxidation of [1](4-) by ferrocenium ion (2 equiv) in the presence of tetramethylthiourea resulted in the derivative [Re(7)C(CO)(21)HgSC(NMe(2))(2)](-) ([7](-)). The molecular structure of [PPN][7] was determined by X-ray crystallography. This is the first example of a carbidoheptarhenate-mercury complex with a neutral ligand on mercury, and ligand exchange was demonstrated by displacement with triethylphosphine. Complex [7](-) can also be prepared by protonating [Re(7)C(CO)(21)HgO(2)CCH(3)](2-) in the presence of tetramethylthiourea. Cyclic voltammetry data to calibrate and compare the redox properties of compounds [1](4-) and [7](-) have been measured.

  11. 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.

  12. 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

  13. 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.)

  14. 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…

  15. Self-assembly of lead chalcogenide nanocrystals.

    PubMed

    Quan, Zewei; Valentin-Bromberg, Loriana; Loc, Welley Siu; Fang, Jiye

    2011-05-02

    This review focuses on recent developments in the self-assembly of lead chalcogenide nanocrystals into two- and three-dimensional superstructures. Self-assembly is categorized by the shapes of building blocks, including nanospheres, nanocubes, nano-octahedra, and nanostars. In the section on nanospheres, rapid assemblies of lead chalcogenide-based multicomponent nanocrystals with additional components, such as semiconductors, noble metals, and magnetic nanocrystals, are further highlighted. In situ self-assembly of lead chalcogenide nanocrystals into one-dimensional nanostructures at elevated temperatures is also covered. Each section of this paper highlights examples extracted from recent publications. Finally, relatively novel properties and applications arising from lead chalcogenide superlattices as typical examples are also discussed.

  16. Bone lead levels are associated with measures of memory impairment in older adults.

    PubMed

    van Wijngaarden, Edwin; Campbell, James R; Cory-Slechta, Deborah A

    2009-07-01

    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 three 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.

  17. 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.

  18. [Lead exposure among Kaohsiung traffic policemen].

    PubMed

    Chiang, H C; Chang, P Y

    1989-06-01

    In this recent century there has been increasing concern over the possible harmful effects of lead from automobile exhaust on human health. Traffic policemen are heavily exposed to automobile exhaust. In Kaohsiung city because of the increasing number of motor vehicles due to rapid urbanization and heavy traffic transportation from suburbs for export trade, traffic policemen have varied exposure experiences. The automobile exhaust of lead additive gasoline was found to be the major type of exposure for traffic policemen whose duties were in the city, while those who worked in the suburb areas were generally exposed to diesel oil exhaust gas. In this study 98 traffic policemen were studied with 118 students used as a control group. Subjects were evaluated for lead absorption and other metabolic effects. The average value of blood lead for traffic policemen (24.43 +/- 5.31 micrograms/dl) in the city of Kaohsiung was significantly (p less than 0.01) higher than for the control group (20.14 +/- 5.07 micrograms/dl). According to other bioindicators it was also found that the mean values of carboxyhemoglobin, urine lead and urine coproporphyrin were significantly higher in the traffic policemen group. Linear regression between blood lead and the duration of employment was also found in this study (R = -0.2447, p less than 0.05). The most reasonable explanations for these findings are the effects of lead emission from motor vehicles and the employment shifting system that cause this effect.

  19. 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.

  20. 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.

  1. 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

  2. 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

    • 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.

    • [Professional stressors and common mental health disorders: Causal links?

      PubMed

      Nicolas, C; Chawky, N; Jourdan-Ionescu, C; Drouin, M-S; Page, C; Houlfort, N; Beauchamp, G; Séguin, M

      2017-03-22

      According to the World Health Organization, depression has become the leading cause of disability in the world, contributing significantly to the burden of health issues especially in the industrialized countries. This is a major public health problem, with potential impact on work climates, productivity at work and the continued existence of the organizations. Some recent studies have examined potential links between professional factors and common mental health disorders, but none have demonstrated a direct causal link.

    • Accelerating coordination in temporal networks by engineering the link order

      PubMed Central

      Masuda, Naoki

      2016-01-01

      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. PMID:26916093

    • How Safe Are Color Additives?

      MedlinePlus

      ... Home For Consumers Consumer Updates How Safe are Color Additives? Share Tweet Linkedin Pin it More sharing ... Consumer Updates RSS Feed Download PDF (380 K) Color additives give the red tint to your fruit ...

    • Leading-edge receptivity for blunt-nose bodies

      NASA Technical Reports Server (NTRS)

      Hammerton, P. W.; Kerschen, E. J.

      1992-01-01

      Boundary-layer receptivity in the leading edge region for bodies with blunt leading edges is investigated in this research program. Receptivity theory provides the link between the unsteady disturbance environment in the freestream and the initial amplitudes of 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.

    • 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

    • Home refinishing, lead paint, and infant blood lead levels.

      PubMed Central

      Rabinowitz, M; Leviton, A; Bellinger, D

      1985-01-01

      We measured the blood lead levels of 249 infants semi-annually from birth to two years of age; we sampled the home paint and recorded any recent home refinishing activity. Mean blood lead from birth to age 2 years did not vary systematically with age but did correlate significantly with the amount of lead in the indoor paint (p less than .01). Refinishing activity in homes with high lead paint was associated with elevations of blood lead averaging 69 per cent. PMID:3976969

    • Lead leaching from pressure cookers.

      PubMed

      Raghunath, R; Nambi, K S

      1998-12-11

      Leachability of lead by tap water and tamarind solution from Indian pressure cookers while cooking with and without a safety valve is studied. Lead contamination of food by cookers is not very high when compared to the daily intake of lead from various food items consumed by the Indian community. However, looking at the very wide range of lead levels leached from various brands of pressure cookers, it certainly seems possible to keep the lead contamination to the minimum by proper choice of the materials used in the manufacture of these pressure cookers. The rubber gasket, which is a very important component of any pressure cooker, contains the maximum lead concentration; the safety valve is another important source leading to lead contamination of cooked food.

    • Safety and Health Topics: Lead

      MedlinePlus

      ... A Spanish version is also available. Lead Battery Manufacturing eTool . OSHA. Management Guidelines for Blood Lead Levels ... exposure occurs in most industry sectors including construction, manufacturing, wholesale trade, transportation, remediation and even recreation. Construction ...

    • Lead (Environmental Health Student Portal)

      MedlinePlus

      ... Pollutants Natural Disasters Drinking Water Waterborne Diseases & Illnesses Water Cycle Water Treatment Videos Games Experiments For Teachers Home ... Pollutants Natural Disasters Drinking Water Waterborne Diseases & Illnesses Water Cycle Water Treatment Lead The Basics Lead is a ...

    • Detergent Additive for Lubricating Oils,

      DTIC Science & Technology

      The Russian patent pertains to a method of producing additives for lubricating oils . A method is known for producing an antiwear additive for... lubricating oils by processing phenols with phosphorus oxychloride, phosphoric acid esters are obtained. In order to give the additive detergent properties

    • 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

    • 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.

    • Toxicants in folk remedies: Implications of elevated blood lead in an American-born infant due to imported diaper powder

      USGS Publications Warehouse

      Karwowski, Mateusz P.; Morman, Suzette A.; Plumlee, Geoffrey S.; Law, Terence; Kellogg, Mark; Woolf, Alan D.

      2016-01-01

      Though most childhood lead exposure in the USA results from ingestion of lead-based paint dust, non-paint sources are increasingly implicated. We present interdisciplinary findings from and policy implications of a case of elevated blood lead (13–18 mcg/dL, reference level <5 mcg/dL) in a 9-month-old infant, linked to a non-commercial Malaysian folk diaper powder. Analyses showed the powder contains 62 % lead by weight (primarily lead oxide) and elevated antimony [1000 parts per million (ppm)], arsenic (55 ppm), bismuth (110 ppm), and thallium (31 ppm). These metals are highly bioaccessible in simulated gastric fluids, but only slightly bioaccessible in simulated lung fluids and simulated urine, suggesting that the primary lead exposure routes were ingestion via hand-mouth transmission and ingestion of inhaled dusts cleared from the respiratory tract. Four weeks after discontinuing use of the powder, the infant’s venous blood lead level was 8 mcg/dL. Unregulated, imported folk remedies can be a source of toxicant exposure. Additional research on import policy, product regulation, public health surveillance, and culturally sensitive risk communication is needed to develop efficacious risk reduction strategies in the USA. The more widespread use of contaminated folk remedies in the countries from which they originate is a substantial concern.

    • Toxicants in folk remedies: implications of elevated blood lead in an American-born infant due to imported diaper powder.

      PubMed

      Karwowski, Mateusz P; Morman, Suzette A; Plumlee, Geoffrey S; Law, Terence; Kellogg, Mark; Woolf, Alan D

      2016-10-04

      Though most childhood lead exposure in the USA results from ingestion of lead-based paint dust, non-paint sources are increasingly implicated. We present interdisciplinary findings from and policy implications of a case of elevated blood lead (13-18 mcg/dL, reference level <5 mcg/dL) in a 9-month-old infant, linked to a non-commercial Malaysian folk diaper powder. Analyses showed the powder contains 62 % lead by weight (primarily lead oxide) and elevated antimony [1000 parts per million (ppm)], arsenic (55 ppm), bismuth (110 ppm), and thallium (31 ppm). These metals are highly bioaccessible in simulated gastric fluids, but only slightly bioaccessible in simulated lung fluids and simulated urine, suggesting that the primary lead exposure routes were ingestion via hand-mouth transmission and ingestion of inhaled dusts cleared from the respiratory tract. Four weeks after discontinuing use of the powder, the infant's venous blood lead level was 8 mcg/dL. Unregulated, imported folk remedies can be a source of toxicant exposure. Additional research on import policy, product regulation, public health surveillance, and culturally sensitive risk communication is needed to develop efficacious risk reduction strategies in the USA. The more widespread use of contaminated folk remedies in the countries from which they originate is a substantial concern.

    • 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.

    • 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

    • 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.

  1. 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.

  2. 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;…

  3. Blood Test: Lead (For Parents)

    MedlinePlus

    ... Your 1- to 2-Year-Old Blood Test: Lead KidsHealth > For Parents > Blood Test: Lead A A A What's in this article? What ... Análisis de sangre: plomo What It Is A lead test is used to determine the amount of ...

  4. 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.

  5. 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.

  6. High speed radiation tolerant data links

    SciTech Connect

    Brewer, Forrest; Incandela, Joseph

    2016-04-01

    This project was slated to design and develop Rad-Hard IP components for 1Gb/s links and supporting hardware designs such as PLL, SER/DES, pad drivers and receivers and custom protocol hardware for the 1Gb/s channel. Also included in the proposal was a study of a hardened memory to be used as a packet buffer for channel and data concentrator components to meet the 1 Gb/s specification. Over the course of the proposal, technology change and innovation of hardware designs lead us away from the 1 Gb/s goal to contemplate much higher performance link IP which, we believed better met the goals of physics experiments. Note that CERN microelectronics had managed to create a 4.7 Gb/s link designed to drive optical fibers and containing infrastructure for connecting much lower bandwidth front-end devices. Our own work to that point had shown the possibility of constructing a link with much lower power, lower physical overhead but of equivalent performance that could be designed to integrate directly onto the front-end ASIC (ADC and data encoding) designs. Substantial overall power savings and experimental simplicity could be achieved by eliminating data transmission to data concentrators and data concentrators and related hardened buffering themselves, with conversion to optical media at a removed distance from the experiment core. We had already developed and tested Rad-Hard SER/DES components (1Gb in 130nm standard cells) and redundant Pad Drivers/Receivers (3+ Gb/s designed and measured performance), and had a viable 1Gb/s link design based on redundant a stuttered clock receiver and classical PLL, so the basic goals of the proposal had been achieved. Below, in chronological order, are the products and tools we constructed, as well as our tests and publications.

  7. 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.

  8. Covalently linked organic networks

    NASA Astrophysics Data System (ADS)

    Tsotsalas, Manuel; Addicoat, Matthew

    2015-02-01

    In this review, we intend to give an overview of the synthesis of well-defined covalently-bound organic network materials such as covalent organic frameworks (COFs), conjugated microporous frameworks (CMPs) and other “ideal polymer networks” and discuss the different approaches in their synthesis and their potential applications. In addition we will describe the common computational approaches and highlight recent achievements in the computational study of their structure and properties. For further information the interested reader is referred to several excellent and more detailed reviews dealing with the synthesis [Dawson 2012; Ding 2013; Feng 2012] and computational aspects [Han 2009; Colón 2014] of the materials presented here.

  9. "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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. The recyclability of lead alloys

    SciTech Connect

    Worcester, A.W.; Sankovitch, M.J.

    1997-12-01

    In 1996, the production of battery lead and alloys from the recycle industry was 3 times the Primary lead production in the United States. The Buick Resource Recovery Center of the Doe Run Lead Company at a capacity of 90,000 tons per year is one of 25 plants recycling lead metal in the United States. This plant was commissioned in 1991 and has been running with a 0.30 Lost Time Accident rate per 200,000 hours of work. The paper delineates and ranks the cost of treating various impurities found in lead.

  15. 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.

  16. 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.

  17. 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.

  18. Project Lead the Way Students More Prepared for Higher Education

    ERIC Educational Resources Information Center

    Van Overschelde, James P.

    2013-01-01

    Project Lead the Way (PLTW) is a hands-on, project-based engineering curriculum for high school and middle school students, which has quadrupled annual enrollment in Texas in five years to over 23,000 students. The diversity of students participating has also increased dramatically. Using six years of longitudinally-linked student data, the…

  19. Study Of Corrosion Of Lead-Sheathed Cables

    NASA Technical Reports Server (NTRS)

    Lee, Rupert U.

    1995-01-01

    Report presents statistical analysis of corrosion failures of lead-sheathed cables that serve as primary communication links at Kennedy Space Center. In study, corrosion-failure data analyzed by use of Weibull distribution in effort to assess effectiveness of cathodic protection and to predict future failures.

  20. 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.

  1. Lead resistant bacteria: lead resistance mechanisms, their applications in lead bioremediation and biomonitoring.

    PubMed

    Naik, Milind Mohan; Dubey, Santosh Kumar

    2013-12-01

    Lead (Pb) is non-bioessential, persistent and hazardous heavy metal pollutant of environmental concern. Bioremediation has become a potential alternative to the existing technologies for the removal and/or recovery of toxic lead from waste waters before releasing it into natural water bodies for environmental safety. To our best knowledge, this is a first review presenting different mechanisms employed by lead resistant bacteria to resist high levels of lead and their applications in cost effective and eco-friendly ways of lead bioremediation and biomonitoring. Various lead resistant mechanisms employed by lead resistant bacteria includes efflux mechanism, extracellular sequestration, biosorption, precipitation, alteration in cell morphology, enhanced siderophore production and intracellular lead bioaccumulation.

  2. Process development for recovery of lead as lead monoxide from lead-bearing waste

    SciTech Connect

    Xue, Sui; Nesbitt, C.C.

    1996-12-31

    A process has been developed from laboratory-scale experiments for the aqueous processing of various lead-bearing wastes. The process exploits the limited solubility of lead in sulfate-rich solutions to effectively separate lead from other metals. The lead sulfate is then completely converted to lead carbonate using sodium carbonate and ammonium carbonate. The effectiveness of this conversion was observed to be sensitive to the solution pH and carbonate concentration. The final stage of the process uses low temperature calcination of the lead carbonate to form PbO. Yellow lead oxide (massicot) is readily formed if calcination is conducted at a temperature at or above 500{degrees}C, while red lead oxide (litharge) is formed at temperatures near 450{degrees}C. A complete economical analysis of the process will be discussed. 7 refs., 8 figs., 3 tabs.

  3. Lead levels of Culex mosquito larvae inhabiting lead utilizing factory

    PubMed Central

    Kitvatanachai, S; Apiwathnasorn, C; Leemingsawat, S; Wongwit, W; Overgaard, HJ

    2011-01-01

    Objective To determine lead level primarily in Culex quinquefasciatus (Cx. quinquefasciatus), and Culex gelidus (Cx. gelidus) larvae inhabiting lead consuming factories, and to putatively estimate eco-toxicological impact of effluents from the firms. Methods Third instars larvae were sampled by standard dipping method and lead concentrations in the larvae and their respective surrounding factory aquatic environments were determined through standard atomic absorption spectrophotometry (AAS). Results Cx. quinquefasciatus was the most abundant species followed by Cx. gelidus. The levels of lead were higher in the Cx. quinquefasciatus (1.08-47.47 µg/g), than in the wastewaters surface (0.01-0.78 µg/mL) from the factories or closer areas around factories. Other species were not reaching the criteria for lead determination. Conclusions The Cx. quinquefasciatus larvae can bio-accumulate the metal and can potentially serve as a biomarker of lead contamination, to complemente conventional techniques. PMID:23569727

  4. 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

  5. Lead poisoning from lead-soldered electric kettles.

    PubMed Central

    Ng, R.; Martin, D. J.

    1977-01-01

    Lead poisoning occurred in two infants, causing lead encephalopathy in one but no symptoms in the other. Both infants had been fed a formula prepared with water boiled in a lead-soldered electric kettle. The diagnosis was suggested by dense metaphyseal bands in radiographs, illustrating the importance of careful examination of "routine" radiographs, particularly in asymptomatic infants. Images FIG. 1A FIG. 1B FIG. 1C FIG. 2 FIG. 3 PMID:837317

  6. 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.

  7. Relationship between prenatal lead exposure and infant blood lead levels.

    PubMed

    Archer, Natalie P; Bradford, Carrie M; Klein, David M; Barnes, Jim; Smith, L J; Villanacci, John F

    2012-10-01

    Recent literature has shown that analyzing newborn dried blood spots (DBS) may be effective in assessing some prenatal environmental exposures, such as exposure to lead. The purpose of this study was to evaluate the relationship between prenatal exposure to lead (as measured by newborn DBS results) and blood lead levels (BLLs) in infants 6 months of age or younger, using public health registry data for infants born in Texas from July 2002 through July 2006. The Texas Child Lead Registry (TCLR) was used to identify infants with documented elevated BLLs of 10 μg/dL or higher as well as infants with documented low BLLs. BLLs for these children were compared to their corresponding newborn DBS results using Pearson correlation coefficients and exact logistic regression models. Overall, a significant but weak positive correlation was found between infant BLLs and corresponding newborn DBS lead levels (r = 0.48). However, the odds of an infant with an elevated newborn DBS lead level having an elevated BLL at 6 months of age or younger were much greater than for an infant with a low newborn DBS lead level of <5 μg/dL (adjusted odds ratio 27.95, 95% CI: 5.52-277.28). Although an association was observed between newborn DBS lead levels and BLLs in infants tested between 0 to 6 months of age, our findings suggest that prenatal exposure may not be the only significant source of lead exposure for infants ≤6 months of age.

  8. 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.

  9. Enantioselective Michael addition of water.

    PubMed

    Chen, Bi-Shuang; Resch, Verena; Otten, Linda G; Hanefeld, Ulf

    2015-02-09

    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.

  10. 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

  11. Making Effective Links for Learning

    ERIC Educational Resources Information Center

    Lawrence, Liz; Lunt, Julie

    2011-01-01

    Science and design and technology (D&T) are often linked, either formally in the curriculum or by making connections in and between lessons. There has been much debate about how this linking serves the needs of the two subjects and what, in practice, the actual relationship is, as the current English National Curriculum (DfEE, 1999) identifies…

  12. 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…

  13. Linking Assessments: Concept and History

    ERIC Educational Resources Information Center

    Kolen, Michael J.

    2004-01-01

    In this article, the history of linking is summarized, and current linking frameworks that have been proposed are considered. Key publications discussed include Flanagan (1951), Angoff (1971), Linn (1993), Mislevy (1992), and Feuer, Holland, Green, Bertenthal, and Hemphill (1999). The article further focuses on the concordance situation for…

  14. Game Changer: Linked Learning Detroit

    ERIC Educational Resources Information Center

    ConnectEd: The California Center for College and Career, 2016

    2016-01-01

    JP Morgan Chase joins the Skillman Foundation, the Ford Foundation, and the Ford Motor Company Fund, whose grants total $7 million and will connect 10,000 Detroit high school students to career education and work experiences over the next three years through Linked Learning Detroit. Learn about Linked Learning Detroit through interviews with…

  15. 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,...

  16. Growth and characterization of lead bromide crystals

    NASA Technical Reports Server (NTRS)

    Singh, N. B.; Gottlieb, M.; Henningsen, T.; Hopkins, R. H.; Mazelsky, R.; Glicksman, M. E.; Coriell, S. R.; Santoro, G. J.; Duval, W. M. B.

    1992-01-01

    Lead(II) bromide was purified by a combination of directional freezing and zone-refining methods. Differential thermal analysis of the lead bromide showed that a destructive phase transformation occurs below the melting temperature. This transformation causes extensive cracking, making it very difficult to grow a large single crystal. Energy of phase transformation for pure lead bromide was determined to be 24.67 cal/g. To circumvent this limitation, crystals were doped by silver bromide which decreased the energy of phase transformation. The addition of silver helped in achieving the size, but enhanced the inhomogeneity in the crystal. The acoustic attenuation constant was almost identical for the pure and doped (below 3000 ppm) crystals.

  17. The leading joint hypothesis for spatial reaching arm motions.

    PubMed

    Ambike, Satyajit; Schmiedeler, James P

    2013-02-01

    The leading joint hypothesis (LJH), developed for planar arm reaching, proposes that the interaction torques experienced by the proximal joint are low compared to the corresponding muscle torques. The human central nervous system could potentially ignore these interaction torques at the proximal (leading) joint with little effect on the wrist trajectory, simplifying joint-level control. This paper investigates the extension of the LJH to spatial reaching. In spatial motion, a number of terms in the governing equation (Euler's angular momentum balance) that vanish for planar movements are non-trivial, so their contributions to the joint torque must be classified as net, interaction or muscle torque. This paper applies definitions from the literature to these torque components to establish a general classification for all terms in Euler's equation. This classification is equally applicable to planar and spatial motion. Additionally, a rationale for excluding gravity torques from the torque analysis is provided. Subjects performed point-to-point reaching movements between targets whose locations ensured that the wrist paths lay in various portions of the arm's spatial workspace. Movement kinematics were recorded using electromagnetic sensors located on the subject's arm segments and thorax. The arm was modeled as a three-link kinematic chain with idealized spherical and revolute joints at the shoulder and elbow. Joint torque components were computed using inverse dynamics. Most movements were 'shoulder-led' in that the interaction torque impulse was significantly lower than the muscle torque impulse for the shoulder, but not the elbow. For the few elbow-led movements, the interaction impulse at the elbow was low, while that at the shoulder was high, and these typically involved large elbow and small shoulder displacements. These results support the LJH and extend it to spatial reaching motion.

  18. 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

  19. Household Chaos--Links with Parenting and Child Behaviour

    ERIC Educational Resources Information Center

    Coldwell, Joanne; Pike, Alison; Dunn, Judy

    2006-01-01

    Background: The study aimed to confirm previous findings showing links between household chaos and parenting in addition to examining whether household chaos was predictive of children's behaviour over and above parenting. In addition, we investigated whether household chaos acts as a moderator between parenting and children's behaviour. Method:…

  20. Optimal utilization of non-additive quantitative trait locus in animal breeding programs.

    PubMed

    Li, Y; Van der Werf, J H J; Kinghorn, B P

    2008-10-01

    Optimal selection on a single identified quantitative trait locus (QTL) with four modes of inheritance: normal autosomal, sex-limited, imprinting and X-linked, was evaluated in four breeding structures: single line selection (SLS), two-way crossing (2WC), three-way crossing (3WC) and reciprocal crossing (RC) by comparing extra benefit from mate selection over index selection to demonstrate effectiveness of mate selection in exploiting non-additive QTL. The results showed that the superiority varied at different QTL inheritance modes, initial favourable allele frequencies and breeding structures. The superiority tended to decrease with the increase of the favourable allele frequency except for over-dominant QTL and imprinted QTL in all breeding structures. Less superiority (below 9%) was observed for a recessive and a fully dominant QTL than for an over-dominant QTL (up to 27.11%). Normal autosomal and sex-linked QTL led to a similar trend of superiority from mate selection but the magnitude of the superiority with the latter was slightly higher than with the former for most combinations of the parameters. A high superiority (6.41-41.54%) was observed from mate selection over index selection for an imprinted QTL. A maternally imprinted QTL tended to lead to higher superiority from mate selection than a paternally imprinted QTL. X-linked QTL led to less superiority from mate selection than the other modes of QTL. A larger superiority from mate selection was observed for a recessive and a fully dominant QTL in structures 3WC and 2WC than structures RC and SLS. The superiority from autosomal QTL and X-linked QTL was lower in the structure RC than in other structures examined.

  1. Waterfalls linked to the National Hydrography Datasets

    USGS Publications Warehouse

    Wieferich, Daniel

    2016-01-01

    This dataset contains information about waterfall location and characteristics. It also provides a linear reference to two National Hydrography Datasets. This dataset is based off the World Waterfall Database (WWD) and other source datasets. The coordinates and spatial attributes from the WWD were used to help verify locations in Google Earth. From there, the USGS HydroLink Tool was used to link data to both the NHDPlusV2.1 (1:100,000 scale) and NHD High Resolution Dataset (1:24,000 scale). This dataset currently includes waterfalls from the states of Indiana, Wisconsin, Michigan, Nebraska, Illinois and Missouri. Waterfalls from other states are planned to be added through time, see the status and update sections of the metadata for additional information.

  2. Lead Levels in Utah Eagles

    NASA Astrophysics Data System (ADS)

    Arnold, Michelle

    2006-10-01

    Lead is a health hazard to most animals, causing adverse effects to the nervous and reproductive systems if in sufficient quantity. Found in most fishing jigs and sinkers, as well as some ammunition used in hunting, this metal can poison wildlife such as eagles. Eagles are raptors, or predatory birds, and their lead exposure would most likely comes from their food -- a fish which has swallowed a sinker or lead shot in carrion (dead animal matter). As part of an ongoing project to investigate the environment lead levels in Utah, the bone lead levels in the wing bones of eagles have been measured for eagle carcasses found throughout Utah. The noninvasive technique of x-ray fluorescence was used, consisting of a Cd-109 radioactive source to activate lead atoms and a HPGe detector with digital electronics to collect the gamma spectra. Preliminary results for the eagles measured to date will be presented.

  3. Lead toxicity in battery workers.

    PubMed

    Qasim, Saeeda Fouzia; Baloch, Malka

    2014-11-01

    Lead poisoning is a medical condition caused by increased levels of lead in the body. Routes of exposure include contaminated air, water, soil, food and consumer products. Occupational exposure is the main cause of lead poisoning in the adults. Two cases of occupational lead poisoning in adult battery workers are hereby presented. Both male patients had initial non-specific symptoms of intermittent abdominal pain, fatigue and headache for 6 - 8 years. Later on, they developed psychosis, slurred speech, tremors of hands and initially underwent treatment for Parkinsonism and Wilson's disease because of clinical misdiagnosis. They were diagnosed with lead poisoning later and were treated successfully with lead chelator (CaNa2 EDTA).

  4. Combined processing of lead concentrates

    NASA Astrophysics Data System (ADS)

    Kubasov, V. L.; Paretskii, V. M.; Sidorin, G. N.; Travkin, V. F.

    2013-06-01

    A combined scheme of processing of lead concentrates with the production of pure metallic lead and the important components containing in these concentrates is considered. This scheme includes sulfating roasting of the lead concentrates and two-stage leaching of the formed cinder with the formation of a sulfate solution and lead sulfate. When transformed into a carbonate form, lead sulfate is used for the production of pure metallic lead. Silver, indium, copper, cadmium, nickel, cobalt, and other important components are separately extracted from a solution. At the last stage, zinc is extracted by either extraction followed by electrolytic extraction of a metal or the return of the forming solution of sulfuric acid to cinder leaching.

  5. 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…

  6. Effect of breast milk lead on infant blood lead levels at 1 month of age.

    PubMed

    Ettinger, Adrienne S; Téllez-Rojo, Martha María; Amarasiriwardena, Chitra; Bellinger, David; Peterson, Karen; Schwartz, Joel; Hu, Howard; Hernández-Avila, Mauricio

    2004-10-01

    maternal blood lead accounted for 30%. Although these levels of lead in breast milk were low, they clearly have a strong influence on infant blood lead levels over and above the influence of maternal blood lead. Additional information on the lead content of dietary alternatives and interactions with other nutritional factors should be considered. However, because human milk is the best and most complete nutritional source for young infants, breast-feeding should be encouraged because the absolute values of the effects are small within this range of lead concentrations.

  7. Undue Lead Absorption and Lead Poisoning in Children: An Overview.

    ERIC Educational Resources Information Center

    Lin-Fu, J. S.

    The toxic effects of lead, a useful metal ubiquitous in the human environment, have long been known. The occupational hazards of lead poisoning were well established by the early 19th century, but plumbism in children caused by paint ingestion was not reported until the turn of the century. Even in 1924, the child was said to live in a "lead…

  8. 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

  9. Indices of potential lead hazard.

    PubMed Central

    Posner, H S

    1977-01-01

    This review is concerned with the concentrations of lead in human whole blood, erythrocytes, plasma, serum, soft tissues, bone, and urine. The extent to which redistribution of some of the bound lead occurs is outlines. The effects of lead on enzyme activities and on the accumulation of metabolic intermediates in the blood and urine are described. A brief section deals with the range of signs and symptoms that can occur and differences seen between symptomatic children and adults. PMID:332498

  10. Archives of Atmospheric Lead Pollution

    NASA Astrophysics Data System (ADS)

    Weiss, Dominik; Shotyk, William; Kempf, Oliver

    Environmental archives such as peat bogs, sediments, corals, trees, polar ice, plant material from herbarium collections, and human tissue material have greatly helped to assess both ancient and recent atmospheric lead deposition and its sources on a regional and global scale. In Europe detectable atmospheric lead pollution began as early as 6000years ago due to enhanced soil dust and agricultural activities, as studies of peat bogs reveal. Increased lead emissions during ancient Greek and Roman times have been recorded and identified in many long-term archives such as lake sediments in Sweden, ice cores in Greenland, and peat bogs in Spain, Switzerland, the United Kingdom, and the Netherlands. For the period since the Industrial Revolution, other archives such as corals, trees, and herbarium collections provide similar chronologies of atmospheric lead pollution, with periods of enhanced lead deposition occurring at the turn of the century and since 1950. The main sources have been industry, including coal burning, ferrous and nonferrous smelting, and open waste incineration until c.1950 and leaded gasoline use since 1950. The greatest lead emissions to the atmosphere all over Europe occurred between 1950 and 1980 due to traffic exhaust. A marked drop in atmospheric lead fluxes found in most archives since the 1980s has been attributed to the phasing out of leaded gasoline. The isotope ratios of lead in the various archives show qualitatively similar temporal changes, for example, the immediate response to the introduction and phasing out of leaded gasoline. Isotope studies largely confirm source assessments based on lead emission inventories and allow the contributions of various anthropogenic sources to be calculated.

  11. Pacemaker leads and cardiac perforation

    PubMed Central

    Prasad, Rachana; Andrews, Richard

    2017-01-01

    This case series highlights the rare but potentially life threatening complication of ventricular perforation caused by pacemaker leads and discusses appropriate investigations and management strategies. PMID:28321317

  12. Toxicity study of lead naphthenate

    PubMed Central

    Peteghem, Th. Van; Devos, H.

    1974-01-01

    van Peteghem, Th., and de Vos, H. (1974).British Journal of Industrial Medicine,31, 233-238. Toxicity study of lead naphthenate. Lead naphthenate is added to oils and greases in order to increase their resistance to high pressures. Experiments on animals and humans showed the possibility of a small amount of percutaneous absorption. An investigation was performed on technicians regularly dealing with these lubricants in order to explore to what extent they had absorbed the lead naphthenate. The degree of absorption was evaluated by measuring the lead content of the blood and the δ-aminolevulinic acid concentration in the urine. Individual results did not permit clearcut conclusions whether an increase in lead absorption had occured or not. Therefore the group of technicians was compared with a group without any occupational contact with lead-containing lubricants but otherwise comparable in occupational and general exposure to lead. To test the significance of the difference between the means of the samples a one-sided t test not assuming equal standard deviations for both populations was used. For any of two compared populations the t test was repeated after rejection of the larger values which were 2·5 standard deviations from the mean value in the exposed population. It appeared that the lead concentration in the blood and the δ-aminolevulinic acid concentration in the urine of people exposed to lead naphthenate-containing lubricants were significantly higher than those concentrations observed in non-exposed persons. PMID:4416678

  13. High temperature superconductor current leads

    DOEpatents

    Hull, John R.; Poeppel, Roger B.

    1995-01-01

    An electrical lead having one end for connection to an apparatus in a cryogenic environment and the other end for connection to an apparatus outside the cryogenic environment. The electrical lead includes a high temperature superconductor wire and an electrically conductive material distributed therein, where the conductive material is present at the one end of the lead at a concentration in the range of from 0 to about 3% by volume, and at the other end of the lead at a concentration of less than about 20% by volume. Various embodiments are shown for groups of high temperature superconductor wires and sheaths.

  14. Lead Poisoning in Wild Birds

    USGS Publications Warehouse

    Lahner, Lesanna L.; Franson, J. Christian

    2009-01-01

    Lead in its various forms has been used for thousands of years, originally in cooking utensils and glazes and more recently in many industrial and commercial applications. However, lead is a potent, potentially deadly toxin that damages many organs in the body and can affect all animals, including humans. By the mid 1990s, lead had been removed from many products in the United States, such as paint and fuel, but it is still commonly used in ammunition for hunting upland game birds, small mammals, and large game animals, as well as in fishing tackle. Wild birds, such as mourning doves, bald eagles, California condors, and loons, can die from the ingestion of one lead shot, bullet fragment, or sinker. According to a recent study on loon mortality, nearly half of adult loons found sick or dead during the breeding season in New England were diagnosed with confirmed or suspected lead poisoning from ingestion of lead fishing weights. Recent regulations in some states have restricted the use of lead ammunition on certain upland game hunting areas, as well as lead fishing tackle in areas frequented by common loons and trumpeter swans. A variety of alternatives to lead are available for use in hunting, shooting sports, and fishing activities.

  15. High temperature superconductor current leads

    DOEpatents

    Hull, J.R.; Poeppel, R.B.

    1995-06-20

    An electrical lead is disclosed having one end for connection to an apparatus in a cryogenic environment and the other end for connection to an apparatus outside the cryogenic environment. The electrical lead includes a high temperature superconductor wire and an electrically conductive material distributed therein, where the conductive material is present at the one end of the lead at a concentration in the range of from 0 to about 3% by volume, and at the other end of the lead at a concentration of less than about 20% by volume. Various embodiments are shown for groups of high temperature superconductor wires and sheaths. 9 figs.

  16. Definition and computation of intermolecular contact in liquids using additively weighted Voronoi tessellation.

    PubMed

    Isele-Holder, Rolf E; Rabideau, Brooks D; Ismail, Ahmed E

    2012-05-10

    We present a definition of intermolecular surface contact by applying weighted Voronoi tessellations to configurations of various organic liquids and water obtained from molecular dynamics simulations. This definition of surface contact is used to link the COSMO-RS model and molecular dynamics simulations. We demonstrate that additively weighted tessellation is the superior tessellation type to define intermolecular surface contact. Furthermore, we fit a set of weights for the elements C, H, O, N, F, and S for this tessellation type to obtain optimal agreement between the models. We use these radii to successfully predict contact statistics for compounds that were excluded from the fit and mixtures. The observed agreement between contact statistics from COSMO-RS and molecular dynamics simulations confirms the capability of the presented method to describe intermolecular contact. Furthermore, we observe that increasing polarity of the surfaces of the examined molecules leads to weaker agreement in the contact statistics. This is especially pronounced for pure water.

  17. The Missing Link: The Use of Link Words and Phrases as a Link to Manuscript Quality

    ERIC Educational Resources Information Center

    Onwuegbuzie, Anthony J.

    2016-01-01

    In this article, I provide a typology of transition words/phrases. This typology comprises 12 dimensions of link words/phrases that capture 277 link words/phrases. Using QDA Miner, WordStat, and SPSS--a computer-assisted mixed methods data analysis software, content analysis software, and statistical software, respectively--I analyzed 74…

  18. 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

  19. Additive Manufacturing of Hierarchical Porous Structures

    SciTech Connect

    Grote, Christopher John

    2016-08-30

    Additive manufacturing has become a tool of choice for the development of customizable components. Developments in this technology have led to a powerful array of printers that t serve a variety of needs. However, resin development plays a crucial role in leading the technology forward. This paper addresses the development and application of printing hierarchical porous structures. Beginning with the development of a porous scaffold, which can be functionalized with a variety of materials, and concluding with customized resins for metal, ceramic, and carbon structures.

  20. Additive manufacturing in production: challenges and opportunities

    NASA Astrophysics Data System (ADS)

    Ahuja, Bhrigu; Karg, Michael; Schmidt, Michael

    2015-03-01

    Additive manufacturing, characterized by its inherent layer by layer fabrication methodology has been coined by many as the latest revolution in the manufacturing industry. Due to its diversification of Materials, processes, system technology and applications, Additive Manufacturing has been synonymized with terminology such as Rapid prototyping, 3D printing, free-form fabrication, Additive Layer Manufacturing, etc. A huge media and public interest in the technology has led to an innovative attempt of exploring the technology for applications beyond the scope of the traditional engineering industry. Nevertheless, it is believed that a critical factor for the long-term success of Additive Manufacturing would be its ability to fulfill the requirements defined by the traditional manufacturing industry. A parallel development in market trends and product requirements has also lead to a wider scope of opportunities for Additive Manufacturing. The presented paper discusses some of the key challenges which are critical to ensure that Additive Manufacturing is truly accepted as a mainstream production technology in the industry. These challenges would highlight on various aspects of production such as product requirements, process management, data management, intellectual property, work flow management, quality assurance, resource planning, etc. In Addition, changing market trends such as product life cycle, mass customization, sustainability, environmental impact and localized production will form the foundation for the follow up discussion on the current limitations and the corresponding research opportunities. A discussion on ongoing research to address these challenges would include topics like process monitoring, design complexity, process standardization, multi-material and hybrid fabrication, new material development, etc.

  1. Main sources of lead and cadmium

    SciTech Connect

    Not Available

    1989-03-01

    Lead-acid batteries used in cars accounted for 65% of the lead in MSW in 1986, and rechargeable nickel-cadmium batteries contributed 52% of the cadmium discarded in the U.S. since 1980. According to an EPA draft report, other major sources of lead are consumer electronics 27%; glass and ceramics, 4%; and such plastic items as PVC resins. Other less significant sources of lead are soldered cans, pigments, brass and bronze products, light bulbs, rubber products, used oil, and lead foil wine bottle wrappers. Cadmium comes from other sources in addition to nickel-cadmium batteries. Plastics using cadmium as stabilizer (mainly PVC) or in pigments contribute 28% of the total amount entering the waste stream. Consumer electronics account for 9% (including cadmium-plated steel chassis on old TV sets and radios); appliances which used to be built with cadmium-plated parts to resist corrosion, 5% pigments, particularly those used in non-newspaper printing inks, textile dyes and paints, 4%; and glass and ceramics, 1.6% of the total.

  2. Concentrations of lead in liver, kidney, and bone of bald and golden eagles.

    PubMed

    Wayland, M; Neugebauer, E; Bollinger, T

    1999-08-01

    The diagnosis of lead poisoning in eagles relies on autopsy information and residue analysis of lead in certain tissues, usually liver or blood. Similarly, the assessment of elevated lead exposure in eagles depends on the determination of lead concentrations in these tissues. Renal and bone lead concentrations have rarely been examined in eagles. We examined relationships among hepatic, renal, and bone lead concentrations in bald and golden eagles from the Canadian prairie provinces. Hepatic and renal lead concentrations were strongly related (R2 = 0.87) while those in liver and bone were significantly but poorly related (R2 = 0.22). Renal lead concentrations of 5 and 18 microg x g-1 (dry weight) corresponded to hepatic lead concentrations of 6 and 30 microg x g-1, the hepatic concentrations that we used as criterion levels associated with elevated lead exposure and death from lead poisoning, respectively. Lead was elevated in 19 of 119 and 21 of 109 liver and kidney samples, respectively. Of these 19 and 21 liver and kidney samples, 14 and 11, respectively, had lead concentrations compatible with death from lead poisoning. Taken together, lead concentrations were elevated in liver or kidney samples from 25 eagles and were compatible with death from lead poisoning in 15. Mean bone lead was higher in eagles with elevated hepatic lead than in those exhibiting background hepatic lead concentrations. However, even in the former group, bone lead concentrations were lower than those in lead-exposed individuals of other species of birds. Bone is probably not a useful tissue for identifying elevated lead exposure in eagles. Three of eleven birds that had been shot had anomalous renal lead concentrations, suggestive of contamination by residue from lead ammunition. It is important to exclude such birds when assessing lead exposure.http://link.springer-ny. com/link/service/journals/00244/bibs/37n2p267.html

  3. Characterization of nano-lead-doped active carbon and its application in lead-acid battery

    NASA Astrophysics Data System (ADS)

    Hong, Bo; Jiang, Liangxing; Xue, Haitao; Liu, Fangyang; Jia, Ming; Li, Jie; Liu, Yexiang

    2014-12-01

    In this paper, nano-lead-doped active carbon (nano-Pb/AC) composite with low hydrogen evolution current for lead-acid battery was prepared by ultrasonic-absorption and chemical-precipitate method. The nano-Pb/AC composite was characterized by SEM, EDS and TEM. The electrochemical characterizations are performed by linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) in a three-electrode system. Since intermediate adsorption is the rate-determining step, the hydrogen evolution reaction (HER) is markedly inhibited as the intermediate adsorption impedance of nano-Pb/AC increased. Meanwhile, the working potential of nano-Pb/AC is widened to the whole potential region of Pb negative plate (from -1.36 V to -0.86 V vs. Hg/HgSO4) in lead-acid battery. In addition, nano-Pb can improve the interfacial compatibility between AC and Pb paste, accordingly relieve the symptoms of carbon floatation. Finally, 2.0 V single-cell flooded lead-acid batteries with 1.0 wt.% nano-Pb/AC or 1.0 wt.% AC addition in negative active materials are assembled. The cell performances test results show that the 3 h rate capacity, quick charging performance, high current discharging performance and cycling performance of nano-Pb/AC modified battery are all improved compared with regular lead-acid battery and AC modified lead-acid battery.

  4. Color Addition and Subtraction Apps

    NASA Astrophysics Data System (ADS)

    Ruiz, Frances; Ruiz, Michael J.

    2015-10-01

    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 in understanding mathematical representations of RGB color. Finally, color addition and subtraction are presented for the X11 colors from web design to illustrate yet another real-life application of color mixing.

  5. Femtosecond fiber laser additive manufacturing of tungsten

    NASA Astrophysics Data System (ADS)

    Bai, Shuang; Liu, Jian; Yang, Pei; Zhai, Meiyu; Huang, Huan; Yang, Lih-Mei

    2016-04-01

    Additive manufacturing (AM) is promising to produce complex shaped components, including metals and alloys, to meet requirements from different industries such as aerospace, defense and biomedicines. Current laser AM uses CW lasers and very few publications have been reported for using pulsed lasers (esp. ultrafast lasers). In this paper, additive manufacturing of Tungsten materials is investigated by using femtosecond (fs) fiber lasers. Various processing conditions are studied, which leads to desired characteristics in terms of morphology, porosity, hardness, microstructural and mechanical properties of the processed components. Fully dense Tungsten part with refined grain and increased hardness was obtained and compared with parts made with different pulse widths and CW laser. The results are evidenced that the fs laser based AM provides more dimensions to modify mechanical properties with controlled heating, rapid melting and cooling rates compared with a CW or long pulsed laser. This can greatly benefit to the make of complicated structures and materials that could not be achieved before.

  6. The Linked Systems Project: Its Implications for Resource Sharing.

    ERIC Educational Resources Information Center

    Avram, Henriette D.

    1986-01-01

    Reviews history of events leading to the Linked Systems Project and describes two major components: communications facility and applications programs. The initial application--sharing of authority data based on the Library of Congress Name Authority Cooperative Project--is discussed, and future applications and their implications are briefly…

  7. Liquid trap seals thermocouple leads

    NASA Technical Reports Server (NTRS)

    Ruppe, E. P.

    1966-01-01

    Liquid trap seals thermocouple leads coming out of a brazing retort that operates with a controlled atmosphere so that air cannot enter the retort and hydrogen cannot escape. The trap is fastened to a duct welded to the retort. Thermocouple leads are led out through the duct and trap, with the fluid forming a gastight seal between the atmosphere and the retort.

  8. Leading Work with Young People

    ERIC Educational Resources Information Center

    Harrison, Roger, Ed.; Benjamin, Cathy, Ed.; Curran, Sheila, Ed.; Hunter, Rob, Ed.

    2007-01-01

    "Leading Work with Young People" provides a selection of writing from a complex and dynamic field of work. The editors bring together key readings and newly commissioned material to present a variety of theoretical and practical perspectives on leading and managing work with young people. The book will equip students with the knowledge, skills,…

  9. Recent developments. [Lead toxicity research

    SciTech Connect

    Needleman, H.L.; Bellinger, D.

    1988-08-01

    This commentary was made to further interpret the authors' studies of lead and child development and to place these studies in the proper biological and epidemiological context. Their studies demonstrate that the use of more sensitive measures of outcome and better epidemiological designs leads to identification of effects at doses previously held to be harmless.

  10. Lead-free primary explosives

    DOEpatents

    Huynh, My Hang V.

    2010-06-22

    Lead-free primary explosives of the formula (cat).sub.Y[M.sup.II(T).sub.X(H.sub.2O).sub.6-X].sub.Z, where T is 5-nitrotetrazolate, and syntheses thereof are described. Substantially stoichiometric equivalents of the reactants lead to high yields of pure compositions thereby avoiding dangerous purification steps.

  11. Fetal lead exposure: antenatal factors

    SciTech Connect

    Ernhart, C.B.; Wolf, A.W.; Sokol, R.J.; Brittenham, G.M.; Erhard, P.

    1985-10-01

    It was hypothesized that maternal blood lead level at delivery and cord blood lead level of the neonate would be affected by maternal use of alcohol, history of alcohol abuse, and smoking. The possibility that iron status, as reflected in maternal serum ferritin, would be related to lead level was also explored. The maternal history of alcohol abuse was unrelated to lead level in 208 samples of maternal blood and 178 samples of cord blood. However, alcohol use during pregnancy was related in a dose-response fashion to maternal and to cord blood lead level. This effect was significant with and without control of maternal smoking. The effect of maternal smoking and serum thiocyanate on maternal and cord blood lead level were also highly significant with and without control of the maternal drinking variable. Serum ferritin was marginally related to lead level for white women and for black infants, but tests of the dichotomized maternal ferritin variable did not yield a significant linkage with maternal or cord blood lead level. The results further support recommendations that women abstain from alcohol consumption and cigarette smoking in pregnancy.

  12. Lead and lead toxicity in domestic and free living birds.

    PubMed

    De Francisco, N; Ruiz Troya, J D; Agüera, E I

    2003-02-01

    At present, domestic and wild fauna are being exposed to aspects and factors which are foreign to the habitat in which they live. One that stands out is the enormous amount and variety of chemical compounds which, in many cases, are highly complex and which are constantly being released into the atmosphere, mainly from agricultural and industrial activity. All these substances affect some species more than others, whether they be plants or animals, from the most insignificant micro-organism to the most evolved species, among them birds. Finally, another cause of mortality in many birds is plumbism, namely death caused by the ingestion of lead. Lead has been one of the main causes of poisoning in man since ancient times due to its use in many activities although it is only recently that this toxicity has been recognized. Moreover, the use of lead pellets for shooting has resulted in the release into the environment of millions of these over many years, with serious repercussions for many bird species populations, which have ingested them either directly or indirectly. Added to this use of lead in cynegetic activities is the fate of the lead weights (sinkers or ballast) used by rod fishers, which sink to the bottom or accumulate on the banks of rivers, lakes, lagoons or reservoirs. The problem arises when these pellets or weights are ingested by birds, mainly Anatidae, which mistake them for the small stones or grit they use to triturate food in their gizzards. Small particles of lead enter the digestive tract, start dissolving in the form of lead salts, are incorporated into the bloodstream and the rest of the body, accumulate in organs like the liver or kidneys, and cause physiological or behavioural changes. When certain concentrations of lead are reached, the birds then die. If lead-poisoned birds are consumed by carrions or predators, the latter also ingest the lead so that they may also be affected or die from plumbism since, being a heavy metal, its

  13. Change in childhood lead exposure prevalence with new reference level.

    PubMed

    Leafe, Morgan; Irigoyen, Matilde; DeLago, Cynthia; Hassan, Amman; Braitman, Leonard

    2015-06-01

    In 2012, the Centers for Disease Control and Prevention changed the "actionable" reference blood lead level from 10 μg/dL to 5 μg/dL, representing the highest 2.5 percentile of lead levels nationwide. In a high-risk urban community, the prevalence of children classified as lead exposed increased ninefold, from 1% to 9.1% (p < .0001) with the new reference level. This dramatic increase in the prevalence of children newly classified as lead exposed will require additional health care and public health resources for tracking, surveillance, and home lead abatement.

  14. Adverse reactions to drug additives.

    PubMed

    Simon, R A

    1984-10-01

    There is a long list of additives used by the pharmaceutical industry. Most of the agents used have not been implicated in hypersensitivity reactions. Among those that have, only reactions to parabens and sulfites have been well established. Parabens have been shown to be responsible for rare immunoglobulin E-mediated reactions that occur after the use of local anesthetics. Sulfites, which are present in many drugs, including agents commonly used to treat asthma, have been shown to provoke severe asthmatic attacks in sensitive individuals. Recent studies indicate that additives do not play a significant role in "hyperactivity." The role of additives in urticaria is not well established and therefore the incidence of adverse reactions in this patient population is simply not known. In double-blind, placebo-controlled studies, reactions to tartrazine or additives other than sulfites, if they occur at all, are indeed quite rare for the asthmatic population, even for the aspirin-sensitive subpopulation.

  15. Radiation Therapy: Additional Treatment Options

    MedlinePlus

    ... SNIPEND SNIPSTART Find A Radiation Oncologist SNIPEND Additional Treatment Options SNIPSTART A A SNIPEND Chemotherapy Medicines prescribed ... such as antibodies, to fight cancer. Novel Targeted Therapies Cancer doctors now know much more about how ...

  16. Calculators and Computers: Graphical Addition.

    ERIC Educational Resources Information Center

    Spero, Samuel W.

    1978-01-01

    A computer program is presented that generates problem sets involving sketching graphs of trigonometric functions using graphical addition. The students use calculators to sketch the graphs and a computer solution is used to check it. (MP)

  17. 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

  18. Lead dodecanoate coatings for the protection of lead and lead-tin alloy artifacts: Two examples

    NASA Astrophysics Data System (ADS)

    De Keersmaecker, Michel; Verbeken, Kim; Adriaens, Annemie

    2014-02-01

    In order to understand the corrosive and morphological characteristics of lead dodecanoate protective coatings on real samples, three pipe organ samples were studied using optical microscopy (OM), scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and electrochemical impedance spectroscopy (EIS). The corrosion products and elemental composition of the top layer of the different pipe organ samples were investigated. The results indicate that the three pipe organ samples are made of an alloy composed mainly of lead and tin. After immersion and the deposition of the protective coating, only lead and no tin is detected, which indicates the formation of a thick coating containing lead dodecanoate complexes.

  19. Food additives and preschool children.

    PubMed

    Martyn, Danika M; McNulty, Breige A; Nugent, Anne P; Gibney, Michael J

    2013-02-01

    Food additives have been used throughout history to perform specific functions in foods. A comprehensive framework of legislation is in place within Europe to control the use of additives in the food supply and ensure they pose no risk to human health. Further to this, exposure assessments are regularly carried out to monitor population intakes and verify that intakes are not above acceptable levels (acceptable daily intakes). Young children may have a higher dietary exposure to chemicals than adults due to a combination of rapid growth rates and distinct food intake patterns. For this reason, exposure assessments are particularly important in this age group. The paper will review the use of additives and exposure assessment methods and examine factors that affect dietary exposure by young children. One of the most widely investigated unfavourable health effects associated with food additive intake in preschool-aged children are suggested adverse behavioural effects. Research that has examined this relationship has reported a variety of responses, with many noting an increase in hyperactivity as reported by parents but not when assessed using objective examiners. This review has examined the experimental approaches used in such studies and suggests that efforts are needed to standardise objective methods of measuring behaviour in preschool children. Further to this, a more holistic approach to examining food additive intakes by preschool children is advisable, where overall exposure is considered rather than focusing solely on behavioural effects and possibly examining intakes of food additives other than food colours.

  20. Anomaly Detection In Additively Manufactured Parts Using Laser Doppler Vibrometery

    SciTech Connect

    Hernandez, Carlos A.

    2015-09-29

    Additively manufactured parts are susceptible to non-uniform structure caused by the unique manufacturing process. This can lead to structural weakness or catastrophic failure. Using laser Doppler vibrometry and frequency response analysis, non-contact detection of anomalies in additively manufactured parts may be possible. Preliminary tests show promise for small scale detection, but more future work is necessary.