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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finkelstein, Myra E., E-mail: myraf@ucsc.edu; Kuspa, Zeka E.; Welch, Alacia

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 frommore » 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.« less

40 CFR 51.117 - Additional provisions for lead.

Code of Federal Regulations, 2010 CFR

2010-07-01

... requirements apply to lead. To the extent they conflict, there requirements are controlling over those of the... the following point sources of lead: Primary lead smelters, Secondary lead smelters, Primary copper... or more batteries per day. Any other stationary source that actually emits 25 or more tons per year...

Molecular dynamics of palmitic acid and lead palmitate in cross-linked linseed oil films: Implications from deuterium magnetic resonance for lead soap formation in traditional oil paintings.

PubMed

Catalano, Jaclyn; Murphy, Anna; Yao, Yao; Zumbulyadis, Nicholas; Centeno, Silvia A; Dybowski, Cecil

2018-02-01

Many oil paintings, dating from the 15th century to the present, are affected by the formation of heavy-metal carboxylates (soaps) that alter the structural integrity and appearance of the works. Through transport phenomena not yet understood, free fatty acids formed from oils used as binders migrate through the paint film and react with heavy-metal ions that are constituents of pigments and/or driers, forming metal carboxylates. The local molecular dynamics of fatty acids and metal carboxylates are factors influencing material transport in these systems. We report temperature-dependent 2 H NMR spectra of palmitic acid and lead palmitate as pure materials, in cross-linked linseed oil films, and in a lead white linseed oil paint film as part of our broader research into metal soap formation. Local dynamics at the α carbon, at the terminal methyl group, and at the middle of the fatty acid chain were observed in specifically deuterated materials. Changes in the dynamic behavior with temperature were observed by the appearance of two species, a solid-like material and a liquid-like material. The relative amounts of the two phases and their deuterium NMR parameters indicate that the amount of liquid-like material and the local dynamics at that site increase with temperature. At the three locations along the chain and at all temperatures, there is a larger percentage of acyl chains of both palmitic acid and lead palmitate that are "mobile" or liquid-like in linseed oil films than there are in the pure materials. However, the percentage of liquid-like species is decreased in a lead white paint film, as compared to a linseed oil matrix. In addition, these experiments indicate that there is a larger percentage of liquid-like acyl chains of palmitic acid than of lead palmitate under identical conditions in these model paint systems. Copyright © 2017 Elsevier Inc. All rights reserved.

A novel AVPR2 splice site mutation leads to partial X-linked nephrogenic diabetes insipidus in two brothers.

PubMed

Schernthaner-Reiter, Marie Helene; Adams, David; Trivellin, Giampaolo; Ramnitz, Mary Scott; Raygada, Margarita; Golas, Gretchen; Faucz, Fabio R; Nilsson, Ola; Nella, Aikaterini A; Dileepan, Kavitha; Lodish, Maya; Lee, Paul; Tifft, Cynthia; Markello, Thomas; Gahl, William; Stratakis, Constantine A

2016-05-01

X-linked nephrogenic diabetes insipidus (NDI, OMIM#304800) is caused by mutations in the arginine vasopressin (AVP, OMIM*192340) receptor type 2 (AVPR2, OMIM*300538) gene. A 20-month-old boy and his 8-year-old brother presented with polyuria, polydipsia, and failure to thrive. Both boys demonstrated partial DDAVP (1-desamino-8-D AVP or desmopressin) responses; thus, NDI diagnosis was delayed. While routine sequencing of AVPR2 showed a potential splice site variant, it was not until exome sequencing confirmed the AVPR2 splice site variant and did not reveal any more likely candidates that the patients' diagnosis was made and proper treatment was instituted. Both patients were hemizygous for two AVPR2 variants predicted in silico to affect AVPR2 messenger RNA (mRNA) splicing. A minigene assay revealed that the novel AVPR2 c.276A>G mutation creates a novel splice acceptor site leading to 5' truncation of AVPR2 exon 2 in HEK293 human kidney cells. Both patients have been treated with high-dose DDAVP with a remarkable improvement of their symptoms and accelerated linear growth and weight gain. We present here a unique case of partial X-linked NDI due to an AVPR2 splice site mutation; patients with diabetes insipidus of unknown etiology may harbor splice site mutations that are initially underestimated in their pathogenicity on sequence analysis. • X-linked nephrogenic diabetes insipidus is caused by AVPR2 mutations, and disease severity can vary depending on the functional effect of the mutation. What is New: • We demonstrate here that a splice site mutation in AVPR2 leads to partial X-linked NDI in two brothers. • Treatment with high-dose DDAVP led to improvement of polyuria and polydipsia, weight gain, and growth.

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

Blood harmane, blood lead, and severity of hand tremor: evidence of additive effects.

PubMed

Louis, Elan D; Factor-Litvak, Pam; Gerbin, Marina; Slavkovich, Vesna; Graziano, Joseph H; Jiang, Wendy; Zheng, Wei

2011-03-01

Tremor is a widespread phenomenon in human populations. Environmental factors are likely to play an etiological role. Harmane (1-methyl-9H-pyrido[3,4-β]indole) is a potent tremor-producing β-carboline alkaloid. Lead is another tremor-producing neurotoxicant. The effects of harmane and lead with respect to tremor have been studied in isolation. We tested the hypothesis that tremor would be particularly severe among individuals who had high blood concentrations of both of these toxicants. Blood concentrations of harmane and lead were each quantified in 257 individuals (106 essential tremor cases and 151 controls) enrolled in an environmental epidemiological study. Total tremor score (range = 0-36) was a clinical measure of tremor severity. The total tremor score ranged from 0 to 36, indicating that a full spectrum of tremor severities was captured in our sample. Blood harmane concentration correlated with total tremor score (p = 0.007), as did blood lead concentration (p = 0.045). The total tremor score was lowest in participants with both low blood harmane and lead concentrations (8.4 ± 8.2), intermediate in participants with high concentrations of either toxicant (10.5 ± 9.8), and highest in participants with high concentrations of both toxicants (13.7 ± 10.4) (p=0.01). Blood harmane and lead concentrations separately correlated with total tremor scores. Participants with high blood concentrations of both toxicants had the highest tremor scores, suggesting an additive effect of these toxicants on tremor severity. Given the very high population prevalence of tremor disorders, identifying environmental determinants is important for primary disease prevention. Copyright © 2010 Elsevier Inc. All rights reserved.

Blood Harmane, Blood Lead, and Severity of Hand Tremor: Evidence of Additive Effects

PubMed Central

Louis, Elan D.; Factor-Litvak, Pam; Gerbin, Marina; Slavkovich, Vesna; Graziano, Joseph H; Jiang, Wendy; Zheng, Wei

2010-01-01

Background Tremor is a widespread phenomenon in human populations. Environmental factors are likely to play an etiological role. Harmane (1-methyl-9H-pyrido[3,4-β]indole) is a potent tremor-producing β-carboline alkaloid. Lead is another tremor-producing neurotoxicant. The effects of harmane and lead with respect to tremor have been studied in isolation. Objectives We tested the hypothesis that tremor would be particularly severe among individuals who had high blood concentrations of both of these toxicants. Methods Blood concentrations of harmane and lead were each quantified in 257 individuals (106 essential tremor cases and 151 controls) enrolled in an environmental epidemiological study. Total tremor score (range = 0 – 36) was a clinical measure of tremor severity. Results The total tremor score ranged from 0 – 36, indicating that a full spectrum of tremor severities was captured in our sample. Blood harmane concentration correlated with total tremor score (p = 0.007), as did blood lead concentration (p = 0.045). The total tremor score was lowest in participants with both low blood harmane and lead concentrations (8.4 ± 8.2), intermediate in participants with high concentrations of either toxicant (10.5 ± 9.8), and highest in participants with high concentrations of both toxicants (13.7 ± 10.4)(p = 0.01). Conclusions Blood harmane and lead concentrations separately correlated with total tremor scores. Participants with high blood concentrations of both toxicants had the highest tremor scores, suggesting an additive effect of these toxicants on tremor severity. Given the very high population prevalence of tremor disorders, identifying environmental determinants is important for primary disease prevention. PMID:21145352

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.

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.

Influence of Additional Leading-Edge Surface Roughness on Performances in Highly Loaded Compressor Cascade

NASA Astrophysics Data System (ADS)

Chen, Shaowen; Xu, Hao; Sun, Shijun; Zhang, Longxin; Wang, Songtao

2015-05-01

Experimental research has been carried out at low speed to investigate the effect of additional leading-edge surface roughness on a highly-loaded axial compressor cascade. A 5-hole aerodynamic probe has been traversed across one pitch to obtain the distribution of total pressure loss coefficient, secondary flow vector, flow angles and other aerodynamic parameters at the exit section. Meanwhile, ink-trace flow visualization has been used to measure the flow fields on the walls of cascades and a detailed topology structure of the flow on the walls has been obtained. Aerodynamic parameters and flow characteristics are compared by arranging different levels of roughness on various parts of the leading edge. The results show that adding surface roughness at the leading edge and on the suction side obviously influences cascade performance. Aggravated 3-D flow separation significantly increases the loss in cascades, and the loss increases till 60% when the level of emery paper is 80 mm. Even there is the potential to improve cascade performance in local area of cascade passage. The influence of the length of surface roughness on cascade performance is not always adverse, and which depends on the position of surface roughness.

ACES microwave link requirements.

PubMed

Uhrich, P M; Guillernot, P; Aubry, P; Gonzalez, F; Salomon, C

2000-01-01

Atomic Clock Ensemble in Space (ACES) is a project of the European Space Agency on-board the future International Space Station (ISS). The payload consists mainly of two atomic frequency standards, one space hydrogen maser (SHM) prepared by the Observatoire de Neuchatel (Switzerland), and one cold atom caesium clock called PHARAO prepared by the CNES (France), with the participation of the BNM-LPTF, the ENS-LKB, and the CNRS-LHA. Because of the anticipated performances of these clocks on-board the ISS, the requirements of the links between the payload and the clocks on the Earth are at the limits of the known potential of the optical or microwave techniques. The microwave link (MWL) requirements are described in this paper. Taking into account the characteristics of the ISS orbit, and fixing an arbitrary limit to the additional noise brought to the clock readings by the MWL, the computation of the required stability leads to two kinds of requirements: the first one at the subpicosecond level over each single continuous pass of the ISS above any Earth station, and the second one at the level of one part in 10(16) and below over a one day or more averaging period. Moreover, the ISS orbit parameters should lead to a knowledge of the ACES clock position at the m level, and of the ACES clock speed at the mm/s level.

Link Adaptation for Mitigating Earth-To-Space Propagation Effects on the NASA SCaN Testbed

NASA Technical Reports Server (NTRS)

Kilcoyne, Deirdre K.; Headley, William C.; Leffke, Zach J.; Rowe, Sonya A.; Mortensen, Dale J.; Reinhart, Richard C.; McGwier, Robert W.

2016-01-01

In Earth-to-Space communications, well-known propagation effects such as path loss and atmospheric loss can lead to fluctuations in the strength of the communications link between a satellite and its ground station. Additionally, the typically unconsidered effect of shadowing due to the geometry of the satellite and its solar panels can also lead to link degradation. As a result of these anticipated channel impairments, NASA's communication links have been traditionally designed to handle the worst-case impact of these effects through high link margins and static, lower rate, modulation formats. The work presented in this paper aims to relax these constraints by providing an improved trade-off between data rate and link margin through utilizing link adaptation. More specifically, this work provides a simulation study on the propagation effects impacting NASA's SCaN Testbed flight software-defined radio (SDR) as well as proposes a link adaptation algorithm that varies the modulation format of a communications link as its signal-to-noise ratio fluctuates. Ultimately, the models developed in this work will be utilized to conduct real-time flight experiments on-board the NASA SCaN Testbed.

Phosphoric acid as an electrolyte additive for lead/acid batteries in electric-vehicle applications

NASA Astrophysics Data System (ADS)

Meissner, E.

The influence of the addition of phosphoric acid to the electrolyte on the performance of gelled lead/acid electric-vehiicle batteries is investigated. This additive reduces the reversible capacity decay of the positive electrode significantly which is observed upon extended cycling when recharge of the battery is performed at low initial rate. This is important when low-rate on-board chargers are used. Pulsed discharge, typical for electric-vehicle application, induces reversible capacity decay more than constant-current discharge at a same depth-of-discharge, as well with as without the addition of phosphoric acid. By contrast, hindrance in presence of H 3PO 4 for both the recharge and the discharge reaction helps to homogenize the state of many individual cells during cycling in long battery strings. Reversible capacity loss, which occurs after extended cycling and when pulsed discharge is applied, can be recovered by a single discharge at very low rate with batteries with and without the addition of phosphoric acid. The discharge-rate dependency of the capacity is significantly reduced when phosphoric acid is added. The pulse discharge behaviour may be better, even if the nominal capacity is reduced. The experimental findings of the influence of phosphoric acid addition is discussed in terms of the aggregate-of-spheres model of reversible capacity decay.

Epoxy Matrices Modified by Green Additives for Recyclable Materials.

PubMed

Henriksen, Martin L; Ravnsbaek, Jens B; Bjerring, Morten; Vosegaard, Thomas; Daasbjerg, Kim; Hinge, Mogens

2017-07-21

Epoxy-based thermosets are one of the most popular matrix materials in many industries, and significant environmental benefits can be obtained by developing a recyclable variant of this widely utilized material. Incorporation of a bio-based disulfide additive within a commercial epoxy system leads to a cross-linked material that can be fractionated under mild and environmentally benign conditions. The material has been analyzed by FTIR and solid-state NMR. Furthermore, modified epoxy matrices with low additive concentrations are demonstrated to have similar mechanical and thermal properties compared to commercially available benchmarks. Thus, additive formulation and fractionation based on green chemistry principles have been demonstrated, and a recyclable epoxy matrix has been developed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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...

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

DTIC Science & Technology

2012-09-20

can be applied to each Gi separately when H is disconnected. ... ( a ) (b) (c) (d) G1 G2 G1 G2 l1 l1 l2l2 m2 m1 r a1 akr a2 m2 m1 r1 s1 l1 l2 r2 s2 a1i...Email: towsley@cs.umass.edu Abstract—We investigate the problem of identifying individual link metrics in a communication network through measuring...the number of links in the network. There lacks, however, a fundamental theory to relate the number of linearly independent paths (and thus link

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....

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.

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.

Synergistic effects of lead thiocyanate additive and solvent annealing on the performance of wide-bandgap perovskite solar cells

DOE PAGES

Yu, Yue; Wang, Changlei; Grice, Corey R.; ...

2017-04-26

Here, we show that the cooperation of lead thiocyanate additive and a solvent annealing process can effectively increase the grain size of mixed-cation lead mixed-halide perovskite thin films while avoiding excess lead iodide formation. As a result, the average grain size of the wide-bandgap mixed-cation lead perovskite thin films increases from 66 ± 24 to 1036 ± 111 nm, and the mean carrier lifetime shows a more than 3-fold increase, from 330 ns to over 1000 ns. Consequently, the average open-circuit voltage of wide-bandgap perovskite solar cells increases by 80 (70) mV, and the average power conversion efficiency (PCE) increasesmore » from 13.44 ± 0.48 (11.75 ± 0.34) to 17.68 ± 0.36 (15.58 ± 0.55)% when measured under reverse (forward) voltage scans. The best-performing wide-bandgap perovskite solar cell, with a bandgap of 1.75 eV, achieves a stabilized PCE of 17.18%.« less

Effect of silicate and phosphate additives on the kinetics of the oxygen evolution reaction in valve-regulated lead/acid batteries

NASA Astrophysics Data System (ADS)

Vinod, M. P.; Vijayamohanan, K.; Joshi, S. N.

Effect of sodium silicate and phosphoric acid additives on the kinetics of oxygen evolution on PbO 2 electrodes in sulfuric acid has been studied in gelled and flooded electrolytes with relevance to valve-regulated lead/acid batteries. A comparison of the open-circuit potential versus time transients, with and without these additives, indicates that the additives suppress self-discharge of the electrodes. Tafel polarization studies also suggest that the addition of phosphoric acid attenuates the rate of oxygen evolution reaction. These findings have been supported with cyclic voltammetric data.

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.

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.

Multiple Pathways Linking Racism to Health Outcomes

PubMed Central

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

2012-01-01

This commentary discusses advances in the conceptual understanding of racism and selected research findings in the social neurosciences. The traditional stress and coping model holds that racism constitutes a source of aversive experiences that, when perceived by the individual, eventually lead to poor health outcomes. Current evidence points to additional psychophysiological pathways linking facets of racist environments with physiological reactions that contribute to disease. The alternative pathways emphasize prenatal experiences, subcortical emotional neural circuits, conscious and preconscious emotion regulation, perseverative cognitions, and negative affective states stemming from racist cognitive schemata. Recognition of these pathways challenges change agents to use an array of cognitive and self-controlling interventions in mitigating racism’s impact. Additionally, it charges policy makers to develop strategies that eliminate deep-seated structural aspects of racism in society. PMID:22518195

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...

SDF1 Reduces Interneuron Leading Process Branching through Dual Regulation of Actin and Microtubules

PubMed Central

Lysko, Daniel E.; Putt, Mary

2014-01-01

Normal cerebral cortical function requires a highly ordered balance between projection neurons and interneurons. During development these two neuronal populations migrate from distinct progenitor zones to form the cerebral cortex, with interneurons originating in the more distant ganglionic eminences. Moreover, deficits in interneurons have been linked to a variety of neurodevelopmental disorders underscoring the importance of understanding interneuron development and function. We, and others, have identified SDF1 signaling as one important modulator of interneuron migration speed and leading process branching behavior in mice, although how SDF1 signaling impacts these behaviors remains unknown. We previously found SDF1 inhibited leading process branching while increasing the rate of migration. We have now mechanistically linked SDF1 modulation of leading process branching behavior to a dual regulation of both actin and microtubule organization. We find SDF1 consolidates actin at the leading process tip by de-repressing calpain protease and increasing proteolysis of branched-actin-supporting cortactin. Additionally, SDF1 stabilizes the microtubule array in the leading process through activation of the microtubule-associated protein doublecortin (DCX). DCX stabilizes the microtubule array by bundling microtubules within the leading process, reducing branching. These data provide mechanistic insight into the regulation of interneuron leading process dynamics during neuronal migration in mice and provides insight into how cortactin and DCX, a known human neuronal migration disorder gene, participate in this process. PMID:24695713

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.

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.

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

Low-molecular-weight model study of peroxide cross-linking of ethylene-propylene-diene rubber using gas chromatography and mass spectrometry II. Addition and combination reactions.

PubMed

Peters, R; van Duin, M; Tonoli, D; Kwakkenbos, G; Mengerink, Y; van Benthem, R A T M; de Koster, C G; Schoenmakers, P J; van der Wal, Sj

2008-08-08

The dicumyl-peroxide-initiated addition and combination reactions of mixtures of alkanes (n-octane, n-decane) and alkenes [5,6-dihydrodicyclopentadiene (DCPDH), 5-ethylidene-2-norbornane (ENBH) and 5-vinylidene-2-norbornane (VNBH)] were studied to mimic the peroxide cross-linking reactions of terpolymerised ethylene, propylene and a diene monomer (EPDM). The reaction products of the mixtures were separated by both gas chromatography (GC) and comprehensive two-dimensional gas chromatography (GCxGC). The separated compounds were identified from their mass spectra and their GC and GCxGC elution pattern. Quantification of the various alkyl/alkyl, alkyl/allyl and allyl/allyl combination products shows that allylic-radicals comprise approximately 60% of the substrate radicals formed. The total concentration of the products formed by combination is found to be independent of the concentration and the type of alkene. The total concentration of the products formed by addition to the alkene increases with increasing concentration of alkene. In addition, the total concentration of the formed addition products depends strongly on the type of the alkene used, viz. VNBH>ENBH approximately DCPDH, which is a consequence of differences in steric hindrance of the unsaturation. The peroxide curing efficiency, defined as the number of moles of cross-linked products formed per mol of peroxide, is 173% using 9% (w/w) 5-vinylidene-2-norbornane (VNBH). This indicates that the addition reaction is recurrent. All these findings are consistent with experimental studies on peroxide curing of EPDM rubber. In addition, the present results provide more-detailed structural information, increasing the understanding of the mechanism of peroxide curing of EPDM. The described approach to use low-molecular-weight model compounds followed by GC-mass spectrometry (MS) and GCxGC-MS analysis is proven to be a very powerful tool to study the cross-linking of EPDM.

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

PubMed

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

2014-11-01

To establish a link between a bullet fired from a suspected firearm, investigation of striation marks are one of the corner stones in the forensic laboratory. Nevertheless, on some occasions, the bullet may be deformed to such extent that traditional investigation of striation marks will be impossible. Fragments of lead can be investigated by lead isotope ratio determination in order to distinguish between bullets with different origin. This approach initially seems reasonable, since the abundance of lead isotopes varies significantly in nature. To make a method valid for forensic purposes, it is important to have a fundamental understanding of the variation within a box of lead bullets and the expected variation between boxes. Studies of variability within and between boxes of ammunition are imperative to perform any type of forensic interpretation, both in an investigative and evaluative context. This work presents an extensive study of variability within and between boxes of ammunition by use of multicollector inductive coupled mass spectrometry. As a first approximation to classify bullets to any given source, a simple and robust graphical method is presented. In addition, an easy-to-use sampling procedure of lead is presented. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Lead extraction from Cathode Ray Tube (CRT) funnel glass: Reaction mechanisms in thermal reduction with addition of carbon (C).

PubMed

Lu, Xingwen; Ning, Xun-An; Chen, Da; Chuang, Kui-Hao; Shih, Kaimin; Wang, Fei

2018-06-01

This study quantitatively determined the extraction of lead from CRT funnel glass and examined the mechanisms of thermally reducing lead in the products of sintering Pb-glass with carbon in the pre-heated furnace. The experimentally derived results indicate that a 90.3 wt% lead extraction efficiency can be achieved with 20 wt% of C addition at 950 °C for 3 min under air. The formation of viscous semi-liquid glass blocked the oxygen supply between the interaction of C and Pb-glass, and was highly effective for the extraction of metallic Pb. A maximum of 87.3% lead recover was obtained with a C to Na 2 CO 3 ratio of 1/3 at 1200 °C. The decrease of C/Na 2 CO 3 ratio enhanced the metallic lead recovery by increasing the glass viscosity for effective sedimentation of metallic lead in the bottom. However, with the further increase of temperature and treatment time, re-vitrification of lead back to silicate-glass matrix was detected in both Pb-glass/C and Pb-glass/C/Na 2 CO 3 systems. The findings indicated that with proper controls, using C as an inexpensive reagent can effectively reduce treatment time and energy, which is crucial to a waste-to-resource technology for economically recovering lead from the waste CRT glass. Copyright © 2018 Elsevier Ltd. All rights reserved.

Does visual impairment lead to additional disability in adults with intellectual disabilities?

PubMed

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

2009-01-01

This study addresses the question to what extent visual impairment leads to additional disability in adults with intellectual disabilities (ID). In a multi-centre cross-sectional study of 269 adults with mild to profound ID, social and behavioural functioning was assessed with observant-based questionnaires, prior to expert assessment of visual function. With linear regression analysis the percentage of variance, explained by levels of visual function, was calculated for the total population and per ID level. A total of 107/269 participants were visually impaired or blind (WHO criteria). On top of the decrease by ID visual impairment significantly decreased daily living skills, communication & language, recognition/communication. Visual impairment did not cause more self-absorbed and withdrawn behaviour or anxiety. Peculiar looking habits correlated with visual impairment and not with ID. In the groups with moderate and severe ID this effect seems stronger than in the group with profound ID. Although ID alone impairs daily functioning, visual impairment diminishes the daily functioning even more. Timely detection and treatment or rehabilitation of visual impairment may positively influence daily functioning, language development, initiative and persistence, social skills, communication skills and insecure movement.

Improvement of the performance of the positive electrode in the lead/acid battery by addition of boric acid

NASA Astrophysics Data System (ADS)

Badawy, W. A.; El-Egamy, S. S.

A major disadvantage of the lead/acid battery is the decrease in voltage during operation which makes it unsuitable for systems sensitive to voltage fluctuations. Additives like BaSO 4 or SrSO 4, which are isomorphous to PbSO 4, have been used to overcome this problem. Phosphoric acid and the various phosphates have long been used to improve the performance of the positive electrode of the battery. A beneficial effect of phosphoric acid is to inhibit the rate of the self-discharge reaction of the positive electrode in the lead/acid battery. However, adverse effects of phosphoric acid include capacity loss in the initial cycles, excessive mossing, especially at high H 3PO 4 concentrations, and poor low-temperature performance (decrease in the rate of PbSO 4 oxidation). The effect of boric acid as an additive substituting for H 3PO 4 has been investigated using linear sweep voltammetry, constant potential and impedance measurements. The results show that boric acid markedly improves the kinetics of the {PbO 2}/{PbSO 4} couple and removes the problems encountered during the usage of H 3PO 4.

Impact of trace element addition on biogas production from food industrial waste--linking process to microbial communities.

PubMed

Feng, Xin Mei; Karlsson, Anna; Svensson, Bo H; Bertilsson, Stefan

2010-10-01

Laboratory-scale reactors treating food industry waste were used to investigate the effects of additions of cobalt (Co), nickel/molybdenum/boron (Ni/Mo/B) and selenium/tungsten (Se/W) on the biogas process and the associated microbial community. The highest methane production (predicted value: 860 mL g(-1) VS) was linked to high Se/W concentrations in combination with a low level of Co. A combination of quantitative real-time PCR of 16S rRNA genes, terminal restriction fragment length polymorphism (T-RFLP) and clone library sequencing was used for the community analysis. The T-RFLP data show a higher diversity for bacteria than for archaea in all the treatments. The most abundant bacterial population (31-55% of the total T-RFLP fragments' intensity) was most closely related to Actinomyces europaeus (94% homology). Two dominant archaeal populations shared 98-99% sequence homology with Methanosarcina siciliae and Methanoculleus bourgensis, respectively. Only limited influence of the trace metal additions was found on the bacterial community composition, with two bacterial populations responding to the addition of a combination of Ni/Mo/B, while the dominant archaeal populations were influenced by the addition of Ni/Mo/B and/or Se/W. The maintenance of methanogenic activity was largely independent of archaeal community composition, suggesting a high degree of functional redundancy in the methanogens of the biogas reactors. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Effect of Zn addition on bulk microstructure of lead-free solder SN100C

NASA Astrophysics Data System (ADS)

Nur Nadirah M., K.; Nurulakmal M., S.

2017-12-01

This paper reports the effect of adding Zn (0.5 wt% Zn, 1.0 wt% Zn) to the bulk microstructure and intermetallic compound (IMC) formation of commercial SN100C (Sn-0.7Cu-0.05Ni+Ge) lead-free solder alloy. Solder alloys were prepared by melting SN100C ingot and Zn shots, and subsequently casted into steel mold. Samples were ground and polished for XRF, and polished samples were then etched for microstructure analysis. Microstructure of bulk solder and the IMC were observed using SEM equipped with EDX. SEM result showed the addition of 0.5 wt% Zn resulted in increased grain size of β-Sn matrix but further addition of Zn (1 wt%) reduced the size of β-Sn dendrites in the bulk solder. Several intermetallic compounds (IMCs) were observed distributed in the Sn matrix; Cu-Zn, Ni-Zn and Cu-Zn-Ni IMC but in relatively small percentage compared to Cu-Zn and Ni-Zn. These particles could be considered as effective nucleating agent that led to finer β-Sn grains. It is expected that the finer β-Sn will contribute towards higher solder strength and the various IMCs present could act as suppressant for Sn diffusion which will then tend to reduce the IMC growth during thermal aging.

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

Let there be light: photo-cross-linked block copolymer nanoparticles.

PubMed

Roy, Debashish; Sumerlin, Brent S

2014-01-01

Polymeric nanoparticles are prepared by selectively cross-linking a photo-sensitive dimethylmaleimide-containing block of a diblock copolymer via UV irradiation. A well-defined photo-cross-linkable block copolymer is prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization of a dimethylmaleimide-functional acrylamido monomer containing photoreactive pendant groups with a poly(N,N-dimethylacrylamide) (PDMA) macro-chain transfer agent. The resulting amphiphilic block copolymers form micelles in water with a hydrophilic PDMA shell and a hydrophobic photo-cross-linkable dimethylmaleimide-containing core. UV irradiation results in photodimerization of the dimethylmaleimide groups within the micelle cores to yield core-cross-linked aggregates. Alternatively, UV irradiation of homogeneous solutions of the block copolymer in a non-selective solvent leads to in situ nanoparticle formation. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

Lead (Environmental Health Student Portal)

MedlinePlus

... limit your exposure. Enviro-Health Links - Lead and Human Health (National Library of Medicine) - Resources on basic information, ... Medicine National Institutes of Health U.S. Department of Health and Human Services

A Millimeter-Wave Digital Link for Wireless MRI

PubMed Central

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

2017-01-01

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. PMID:27810803

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.

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.

Where Will LEAD Lead?

ERIC Educational Resources Information Center

Wildman, Louis

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

Stabilization of lead in incineration fly ash by moderate thermal treatment with sodium hydroxide addition

PubMed Central

Yang, Yuanyi; He, Yong; Sun, Xiaolong; Ge, Li-Ya; Zhang, Kewei; Yang, Weizhong

2017-01-01

Municipal solid waste (MSW) incineration fly ash (IFA) can be potentially reused as a substitute for some raw materials, but treatment for detoxification is indispensable owing to high contents of heavy metals in fly ash. In the present work, due to excessive leaching concentration of lead (Pb), a moderate thermal treatment with sodium hydroxide (NaOH) addition was employed to stabilize Pb in IFA. The moderate thermal treatment was performed under relatively low temperature ranging from 300 to 500°C and at retention time from 1 to 3 h with NaOH addition in a range of 1 to 9%. Leaching results showed that leaching concentrations of Pb in IFA leachates decreased below the standard for hazardous waste identification (5 mg/L) in China under all treatment scenarios. With the increase of temperature, retention time and the amount of NaOH, the concentration of Pb were further suppressed in IFA leachates. Especially, at 500°C for 3 h with 9% NaOH addition, the concentration of Pb dropped to 0.18 mg/L, which was below the standard for sanitary landfill (0.25 mg/L) in China. In thermal process, needle-like crystallites melted to form granules and clumps with compacter structure and less pores. After the thermal treatment, water-soluble and exchangeable fractions of Pb significantly decreased. Therefore, the thermal treatment coupled with NaOH could be applied to realize the environmentally sound management of MSW IFA. PMID:28586368

Stabilization of lead in incineration fly ash by moderate thermal treatment with sodium hydroxide addition.

PubMed

Gong, Bing; Deng, Yi; Yang, Yuanyi; He, Yong; Sun, Xiaolong; Ge, Li-Ya; Zhang, Kewei; Yang, Weizhong

2017-01-01

Municipal solid waste (MSW) incineration fly ash (IFA) can be potentially reused as a substitute for some raw materials, but treatment for detoxification is indispensable owing to high contents of heavy metals in fly ash. In the present work, due to excessive leaching concentration of lead (Pb), a moderate thermal treatment with sodium hydroxide (NaOH) addition was employed to stabilize Pb in IFA. The moderate thermal treatment was performed under relatively low temperature ranging from 300 to 500°C and at retention time from 1 to 3 h with NaOH addition in a range of 1 to 9%. Leaching results showed that leaching concentrations of Pb in IFA leachates decreased below the standard for hazardous waste identification (5 mg/L) in China under all treatment scenarios. With the increase of temperature, retention time and the amount of NaOH, the concentration of Pb were further suppressed in IFA leachates. Especially, at 500°C for 3 h with 9% NaOH addition, the concentration of Pb dropped to 0.18 mg/L, which was below the standard for sanitary landfill (0.25 mg/L) in China. In thermal process, needle-like crystallites melted to form granules and clumps with compacter structure and less pores. After the thermal treatment, water-soluble and exchangeable fractions of Pb significantly decreased. Therefore, the thermal treatment coupled with NaOH could be applied to realize the environmentally sound management of MSW IFA.

Effect of SiO2 addition and gamma irradiation on the lithium borate glasses

NASA Astrophysics Data System (ADS)

Raut, A. P.; Deshpande, V. K.

2018-01-01

The physical properties like density, glass transition temperature (Tg), and ionic conductivity of lithium borate (LB) glasses with SiO2 addition were measured before and after gamma irradiation. Remarkable changes in properties have been obtained in the physical properties of LB glasses with SiO2 addition and after gamma irradiation. The increase in density and glass transition temperature of LB glasses with SiO2 addition has been explained with the help of increase in density of cross linking due to SiO4 tetrahedra formation. The increase in ionic conductivity with SiO2 addition was explained with the help of ‘mixed glass former effect’. The increase in density and Tg of LB glasses with SiO2 addition after gamma irradiation has been attributed to fragmentation of bigger ring structure into smaller rings, which increases the density of cross linking and hence compaction. The exposure of gamma irradiation has lead to decrease in ionic conductivity of LB glasses with SiO2 addition. The atomic displacement caused by gamma irradiation resulted in filling of interstices and decrease in trapping sites. This explains the obtained decrease in ionic conductivity after gamma irradiation of glasses. The obtained results of effect of SiO2 addition and gamma irradiation on the density, Tg and ionic conductivity has been supported by FTIR results.

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.

BLOOD LEAD CONCENTRATION AND DELAYED PUBERTY IN GIRLS

EPA Science Inventory

Background
Environmental lead exposure has been linked to alterations in growth and endocrine function. It is not known whether such exposure affects pubertal development.

Methods
We analyzed the relations between blood lead concentration and pubertal...

Hydrogels Prepared from Cross-Linked Nanofibrillated Cellulose

Treesearch

Sandeep S. Nair; J.Y. Zhu; Yulin Deng; Arthur J. Ragauskas

2014-01-01

Nanocomposite hydrogels were developed by cross-linking nanofibrillated cellulose with poly(methyl vinyl ether-co-maleic acid) and polyethylene glycol. The cross-linked hydrogels showed enhanced water absorption and gel content with the addition of nanocellulose. In addition, the thermal stability, mechanical strength, and modulus increased with an increase in the...

Interplay between DNA repair and inflammation, and the link to cancer

PubMed Central

Kidane, Dawit; Chae, Wook Jin; Czochor, Jennifer; Eckert, Kristin A.; Glazer, Peter M.; Bothwell, Alfred L. M.; Sweasy, Joann B.

2015-01-01

DNA damage and repair are linked to cancer. DNA damage that is induced endogenously or from exogenous sources has the potential to result in mutations and genomic instability if not properly repaired, eventually leading to cancer. Inflammation is also linked to cancer. Reactive oxygen and nitrogen species (RONs) produced by inflammatory cells at sites of infection can induce DNA damage. RONs can also amplify inflammatory responses, leading to increased DNA damage. Here, we focus on the links between DNA damage, repair, and inflammation, as they relate to cancer. We examine the interplay between chronic inflammation, DNA damage and repair and review recent findings in this rapidly emerging field, including the links between DNA damage and the innate immune system, and the roles of inflammation in altering the microbiome, which subsequently leads to the induction of DNA damage in the colon. Mouse models of defective DNA repair and inflammatory control are extensively reviewed, including treatment of mouse models with pathogens, which leads to DNA damage. The roles of microRNAs in regulating inflammation and DNA repair are discussed. Importantly, DNA repair and inflammation are linked in many important ways, and in some cases balance each other to maintain homeostasis. The failure to repair DNA damage or to control inflammatory responses has the potential to lead to cancer. PMID:24410153

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.

OHD - Additional Links

Science.gov Websites

Site Map News Organization Search NWS All NOAA Go Local forecast by "City, St" Search by city or zip code. Press enter or select the go button to submit request City, St Go Front Office OWP

Leading-edge receptivity for blunt-nose bodies

NASA Technical Reports Server (NTRS)

Kerschen, Edward J.

1991-01-01

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

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

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Kinetics of hydrogen-evolution reaction on lead and lead-alloy electrodes in sulfuric acid electrolyte with phosphoric acid and antimony additives

NASA Astrophysics Data System (ADS)

Venugopalan, S.

1994-03-01

The kinetics of the hydrogen-evolution reaction (HER) on smooth Pb, PbCaSn and PbSbSe alloy electrodes is studied in H 2SO 4 (3-10 M) electrolyte that contains phosphoric acid (0-40 g l -1) and antimony (0-10 mg l -1) using galvanostatic polarization in the Tafel domain. A direct correlation is found between iO,H and icor on lead and lead-alloy electrodes with varying concentrations of H 3PO 4 and Sb(III) in H 2SO 4. The maximum suppression of the HER occurs with 20 g l -1 H 3PO 4 in H 2SO 4 for both lead and lead alloys. The data are explained in the light of a model that employs adsorption of H 3PO 4 at the electrode/ electrolyte interface.

Linking School and Work to Accelerate Student Results.

ERIC Educational Resources Information Center

Workforce Economics, 1999

1999-01-01

This serial issue focusing on the theme of "School-to-Work." The two articles it contains describe promising practices that benefit individual students who participate. The first article, "Connecting the Dots: Linking School and Work to Accelerate Student Results," examines how schools and businesses are linking up, leading to benefits for…

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Toxic effects of lead and nickel nitrate on rat liver chromatin components.

PubMed

Rabbani-Chadegani Iii, Azra; Fani, Nesa; Abdossamadi, Sayeh; Shahmir, Nosrat

2011-01-01

The biological activity of heavy metals is related to their physicochemical interaction with biological receptors. In the present study, the effect of low concentrations of nickel nitrate and lead nitrate (<0.3 mM) on rat liver soluble chromatin and histone proteins was examined. The results showed that addition of various concentrations of metals to chromatin solution preceded the chromatin into aggregation and precipitation in a dose-dependant manner; however, the extent of absorbance changes at 260 and 400 nm was different between two metals. Gel electrophoresis of histone proteins and DNA of the supernatants obtained from the metal-treated chromatin and the controls revealed higher affinity of lead nitrate to chromatin compared to nickel nitrate. Also, the binding affinity of lead nitrate to histone proteins free in solution was higher than nickel. On the basis of the results, it is concluded that lead reacts with chromatin components even at very low concentrations and induce chromatin aggregation through histone-DNA cross-links. Whereas, nickel nitrate is less effective on chromatin at low concentrations, suggesting higher toxicity of lead nitrate on chromatin compared to nickel. Copyright © 2010 Wiley Periodicals, Inc.

Node, Node-Link, and Node-Link-Group Diagrams: An Evaluation.

PubMed

Saket, Bahador; Simonetto, Paolo; Kobourov, Stephen; Börner, Katy

2014-12-01

Effectively showing the relationships between objects in a dataset is one of the main tasks in information visualization. Typically there is a well-defined notion of distance between pairs of objects, and traditional approaches such as principal component analysis or multi-dimensional scaling are used to place the objects as points in 2D space, so that similar objects are close to each other. In another typical setting, the dataset is visualized as a network graph, where related nodes are connected by links. More recently, datasets are also visualized as maps, where in addition to nodes and links, there is an explicit representation of groups and clusters. We consider these three Techniques, characterized by a progressive increase of the amount of encoded information: node diagrams, node-link diagrams and node-link-group diagrams. We assess these three types of diagrams with a controlled experiment that covers nine different tasks falling broadly in three categories: node-based tasks, network-based tasks and group-based tasks. Our findings indicate that adding links, or links and group representations, does not negatively impact performance (time and accuracy) of node-based tasks. Similarly, adding group representations does not negatively impact the performance of network-based tasks. Node-link-group diagrams outperform the others on group-based tasks. These conclusions contradict results in other studies, in similar but subtly different settings. Taken together, however, such results can have significant implications for the design of standard and domain snecific visualizations tools.

Depletion of Saccharomyces cerevisiae tRNAHis Guanylyltransferase Thg1p Leads to Uncharged tRNAHis with Additional m5C

PubMed Central

Gu, Weifeng; Hurto, Rebecca L.; Hopper, Anita K.; Grayhack, Elizabeth J.; Phizicky, Eric M.

2005-01-01

The essential Saccharomyces cerevisiae tRNAHis guanylyltransferase (Thg1p) is responsible for the unusual G−1 addition to the 5′ end of cytoplasmic tRNAHis. We report here that tRNAHis from Thg1p-depleted cells is uncharged, although histidyl tRNA synthetase is active and the 3′ end of the tRNA is intact, suggesting that G−1 is a critical determinant for aminoacylation of tRNAHis in vivo. Thg1p depletion leads to activation of the GCN4 pathway, most, but not all, of which is Gcn2p dependent, and to the accumulation of tRNAHis in the nucleus. Surprisingly, tRNAHis in Thg1p-depleted cells accumulates additional m5C modifications, which are delayed relative to the loss of G−1 and aminoacylation. The additional modification is likely due to tRNA m5C methyltransferase Trm4p. We developed a new method to map m5C residues in RNA and localized the additional m5C to positions 48 and 50. This is the first documented example of the accumulation of additional modifications in a eukaryotic tRNA species. PMID:16135808

Lead-contaminated imported tamarind candy and children's blood lead levels.

PubMed Central

Lynch, R A; Boatright, D T; Moss, S K

2000-01-01

In 1999, an investigation implicated tamarind candy as the potential source of lead exposure for a child with a significantly elevated blood lead level (BLL). The Oklahoma City-County Health Department tested two types of tamarind suckers and their packaging for lead content. More than 50% of the tested suckers exceeded the US Food and Drug Administration (FDA) Level of Concern for lead in this type of product. The authors calculated that a child consuming one-quarter to one-half of either of the two types of suckers in a day would exceed the maximum FDA Provis onal Tolerable Intake for lead. High lead concentrations in the two types of wrappers suggested leaching as a potential source of contamination. The authors used the Environmental Protection Agency's Integrated Exposure Uptake Biokinetic (IEUBK) model to predict the effects of consumption of contaminated tamarind suckers on populat on BLLs. The IEUBK model predicted that consumption of either type of sucker at a rate of one per day would result in dramatic increases in mean BLLs for children ages 6-84 months in Oklahoma and in the percentage of children wth elevated BLLs (> or =10 micrograms per deciliter [microg/dL]). The authors conclude that consumption of these products represents a potential public health threat. In addition, a history of lead contamination in imported tamarind products suggests that import control measures may not be completely effective in preventing additional lead exposure. PMID:11354337

Lead-contaminated imported tamarind candy and children's blood lead levels.

PubMed

Lynch, R A; Boatright, D T; Moss, S K

2000-01-01

In 1999, an investigation implicated tamarind candy as the potential source of lead exposure for a child with a significantly elevated blood lead level (BLL). The Oklahoma City-County Health Department tested two types of tamarind suckers and their packaging for lead content. More than 50% of the tested suckers exceeded the US Food and Drug Administration (FDA) Level of Concern for lead in this type of product. The authors calculated that a child consuming one-quarter to one-half of either of the two types of suckers in a day would exceed the maximum FDA Provis onal Tolerable Intake for lead. High lead concentrations in the two types of wrappers suggested leaching as a potential source of contamination. The authors used the Environmental Protection Agency's Integrated Exposure Uptake Biokinetic (IEUBK) model to predict the effects of consumption of contaminated tamarind suckers on populat on BLLs. The IEUBK model predicted that consumption of either type of sucker at a rate of one per day would result in dramatic increases in mean BLLs for children ages 6-84 months in Oklahoma and in the percentage of children wth elevated BLLs (> or =10 micrograms per deciliter [microg/dL]). The authors conclude that consumption of these products represents a potential public health threat. In addition, a history of lead contamination in imported tamarind products suggests that import control measures may not be completely effective in preventing additional lead exposure.

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.

Expression of ALS/FTD-linked mutant CCNF in zebrafish leads to increased cell death in the spinal cord and an aberrant motor phenotype.

PubMed

Hogan, Alison L; Don, Emily K; Rayner, Stephanie L; Lee, Albert; Laird, Angela S; Watchon, Maxinne; Winnick, Claire; Tarr, Ingrid S; Morsch, Marco; Fifita, Jennifer A; Gwee, Serene S L; Formella, Isabel; Hortle, Elinor; Yuan, Kristy C; Molloy, Mark P; Williams, Kelly L; Nicholson, Garth A; Chung, Roger S; Blair, Ian P; Cole, Nicholas J

2017-07-15

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive, fatal neurodegenerative disease characterised by the death of upper and lower motor neurons. Approximately 10% of cases have a known family history of ALS and disease-linked mutations in multiple genes have been identified. ALS-linked mutations in CCNF were recently reported, however the pathogenic mechanisms associated with these mutations are yet to be established. To investigate possible disease mechanisms, we developed in vitro and in vivo models based on an ALS-linked missense mutation in CCNF. Proteomic analysis of the in vitro models identified the disruption of several cellular pathways in the mutant model, including caspase-3 mediated cell death. Transient overexpression of human CCNF in zebrafish embryos supported this finding, with fish expressing the mutant protein found to have increased levels of cleaved (activated) caspase-3 and increased cell death in the spinal cord. The mutant CCNF fish also developed a motor neuron axonopathy consisting of shortened primary motor axons and increased frequency of aberrant axonal branching. Importantly, we demonstrated a significant correlation between the severity of the CCNF-induced axonopathy and a reduced motor response to a light stimulus (photomotor response). This is the first report of an ALS-linked CCNF mutation in vivo and taken together with the in vitro model identifies the disruption of cell death pathways as a significant consequence of this mutation. Additionally, this study presents a valuable new tool for use in ongoing studies investigating the pathobiology of ALS-linked CCNF mutations. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Mean link versus average plaquette tadpoles in lattice NRQCD

NASA Astrophysics Data System (ADS)

Shakespeare, Norman H.; Trottier, Howard D.

1999-03-01

We compare mean-link and average plaquette tadpole renormalization schemes in the context of the quarkonium hyperfine splittings in lattice NRQCD. Simulations are done for the three quarkonium systems c overlinec, b overlinec, and b overlineb. The hyperfine splittings are computed both at leading and at next-to-leading order in the relativistic expansion. Results are obtained at a large number of lattice spacings. A number of features emerge, all of which favor tadpole renormalization using mean links. This includes much better scaling of the hyperfine splittings in the three quarkonium systems. We also find that relativistic corrections to the spin splittings are smaller with mean-link tadpoles, particularly for the c overlinec and b overlinec systems. We also see signs of a breakdown in the NRQCD expansion when the bare quark mass falls below about one in lattice units (with the bare quark masses turning out to be much larger with mean-link tadpoles).

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.

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…

Classifying quantum entanglement through topological links

NASA Astrophysics Data System (ADS)

Quinta, Gonçalo M.; André, Rui

2018-04-01

We propose an alternative classification scheme for quantum entanglement based on topological links. This is done by identifying a nonrigid ring to a particle, attributing the act of cutting and removing a ring to the operation of tracing out the particle, and associating linked rings to entangled particles. This analogy naturally leads us to a classification of multipartite quantum entanglement based on all possible distinct links for a given number of rings. To determine all different possibilities, we develop a formalism that associates any link to a polynomial, with each polynomial thereby defining a distinct equivalence class. To demonstrate the use of this classification scheme, we choose qubit quantum states as our example of physical system. A possible procedure to obtain qubit states from the polynomials is also introduced, providing an example state for each link class. We apply the formalism for the quantum systems of three and four qubits and demonstrate the potential of these tools in a context of qubit networks.

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

DTIC Science & Technology

1974-12-01

alkyls would result in reduced environmental pollution by lead and possibly other noxious emissions. The results of these investigations are presented and assessed. Topics requiring study or further development are identified.

Link-N: The missing link towards intervertebral disc repair is species-specific

PubMed Central

Bach, Frances C.; Laagland, Lisanne T.; Grant, Michael P.; Creemers, Laura B.; Ito, Keita; Meij, Björn P.; Mwale, Fackson

2017-01-01

Introduction Degeneration of the intervertebral disc (IVD) is a frequent cause for back pain in humans and dogs. Link-N stabilizes proteoglycan aggregates in cartilaginous tissues and exerts growth factor-like effects. The human variant of Link-N facilitates IVD regeneration in several species in vitro by inducing Smad1 signaling, but it is not clear whether this is species specific. Dogs with IVD disease could possibly benefit from Link-N treatment, but Link-N has not been tested on canine IVD cells. If Link-N appears to be effective in canines, this would facilitate translation of Link-N into the clinic using the dog as an in vivo large animal model for human IVD degeneration. Materials and methods This study’s objective was to determine the effect of the human and canine variant of Link-N and short (s) Link-N on canine chondrocyte-like cells (CLCs) and compare this to those on already studied species, i.e. human and bovine CLCs. Extracellular matrix (ECM) production was determined by measuring glycosaminoglycan (GAG) content and histological evaluation. Additionally, the micro-aggregates’ DNA content was measured. Phosphorylated (p) Smad1 and -2 levels were determined using ELISA. Results Human (s)Link-N induced GAG deposition in human and bovine CLCs, as expected. In contrast, canine (s)Link-N did not affect ECM production in human CLCs, while it mainly induced collagen type I and II deposition in bovine CLCs. In canine CLCs, both canine and human (s)Link-N induced negligible GAG deposition. Surprisingly, human and canine (s)Link-N did not induce Smad signaling in human and bovine CLCs. Human and canine (s)Link-N only mildly increased pSmad1 and Smad2 levels in canine CLCs. Conclusions Human and canine (s)Link-N exerted species-specific effects on CLCs from early degenerated IVDs. Both variants, however, lacked the potency as canine IVD regeneration agent. While these studies demonstrate the challenges of translational studies in large animal models, (s)Link

Link-N: The missing link towards intervertebral disc repair is species-specific.

PubMed

Bach, Frances C; Laagland, Lisanne T; Grant, Michael P; Creemers, Laura B; Ito, Keita; Meij, Björn P; Mwale, Fackson; Tryfonidou, Marianna A

2017-01-01

Degeneration of the intervertebral disc (IVD) is a frequent cause for back pain in humans and dogs. Link-N stabilizes proteoglycan aggregates in cartilaginous tissues and exerts growth factor-like effects. The human variant of Link-N facilitates IVD regeneration in several species in vitro by inducing Smad1 signaling, but it is not clear whether this is species specific. Dogs with IVD disease could possibly benefit from Link-N treatment, but Link-N has not been tested on canine IVD cells. If Link-N appears to be effective in canines, this would facilitate translation of Link-N into the clinic using the dog as an in vivo large animal model for human IVD degeneration. This study's objective was to determine the effect of the human and canine variant of Link-N and short (s) Link-N on canine chondrocyte-like cells (CLCs) and compare this to those on already studied species, i.e. human and bovine CLCs. Extracellular matrix (ECM) production was determined by measuring glycosaminoglycan (GAG) content and histological evaluation. Additionally, the micro-aggregates' DNA content was measured. Phosphorylated (p) Smad1 and -2 levels were determined using ELISA. Human (s)Link-N induced GAG deposition in human and bovine CLCs, as expected. In contrast, canine (s)Link-N did not affect ECM production in human CLCs, while it mainly induced collagen type I and II deposition in bovine CLCs. In canine CLCs, both canine and human (s)Link-N induced negligible GAG deposition. Surprisingly, human and canine (s)Link-N did not induce Smad signaling in human and bovine CLCs. Human and canine (s)Link-N only mildly increased pSmad1 and Smad2 levels in canine CLCs. Human and canine (s)Link-N exerted species-specific effects on CLCs from early degenerated IVDs. Both variants, however, lacked the potency as canine IVD regeneration agent. While these studies demonstrate the challenges of translational studies in large animal models, (s)Link-N still holds a regenerative potential for humans.

Cross-linking Chemistry of Squid Beak*

PubMed Central

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

2010-01-01

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 (1H 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. PMID:20870720

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.

ADIPOCYTOKINES AND OBESITY-LINKED DISORDERS

PubMed Central

OUCHI, NORIYUKI; OHASHI, KOJI; SHIBATA, REI; MUROHARA, TOYOAKI

2012-01-01

ABSTRACT Obesity is closely associated with an increased risk for metabolic and cardiovascular diseases. Adipose tissue produces a number of secretory bioactive substances, also known as adipocytokines or adipokines, which directly affect adjacent or distant organs. Most adipocytokines are pro-inflammatory, thereby promoting the obesity-linked disorders. In contrast, there are a small number of adipocytokines that exhibit anti-inflammatory properties. It is now recognized that dysregulated production or secretion of adipocytokines caused by adipocyte dysfunction leads to the development of obesity-linked complications. In this review, we focus on the functional role of several adipocytokines in metabolic and cardiovascular diseases. PMID:22515108

Lead generation and examples opinion regarding how to follow up hits.

PubMed

Orita, Masaya; Ohno, Kazuki; Warizaya, Masaichi; Amano, Yasushi; Niimi, Tatsuya

2011-01-01

In fragment-based drug discovery (FBDD), not only identifying the starting fragment hit to be developed but also generating a drug lead from that starting fragment hit is important. Converting fragment hits to leads is generally similar to a high-throughput screening (HTS) hits-to-leads approach in that properties associated with activity for a target protein, such as selectivity against other targets and absorption, distribution, metabolism, excretion, and toxicity (ADME/Tox), and physicochemical properties should be taken into account. However, enhancing the potency of the fragment hit is a key requirement in FBDD, unlike HTS, because initial fragment hits are generally weak. This enhancement is presently achieved by adding additional chemical groups which bind to additional parts of the target protein or by joining or combining two or more hit fragments; however, strategies for effecting greater improvements in effective activity are needed. X-ray analysis is a key technology attractive for converting fragments to drug leads. This method makes it clear whether a fragment hit can act as an anchor and provides insight regarding introduction of functional groups to improve fragment activity. Data on follow-up chemical synthesis of fragment hits has allowed for the differentiation of four different strategies: fragment optimization, fragment linking, fragment self-assembly, and fragment evolution. Here, we discuss our opinion regarding how to follow up on fragment hits, with a focus on the importance of fragment hits as an anchor moiety to so-called hot spots in the target protein using crystallographic data. Copyright © 2011 Elsevier Inc. All rights reserved.

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.

Pacemaker leads: performance and progress.

PubMed

de Voogt, W G

1999-03-11

Pacing leads remain the "weaker link" of the permanent pacing system. Lead failure has been an issue since the beginning of implantable pacemaker therapy. Modern electronics have brought about considerable progress in pacing technology, but lead design has been slower to evolve and problems persist. IS-1 standardization must be considered a significant advance, but some issues regarding IS-1 standardization persist and have been the cause of some compatibility problems. With respect to lead insulation, silicone has proved to offer total reliability for > 30 years. In the search for better handling characteristics, polyurethane 80A was employed for bipolar leads, but it failed to demonstrate satisfactory insulating properties. New insulation materials, such as ethylene-fluoro-ethylene (ETFE), and coated wire technology look promising, having shown 99.32% survival at 5-year follow-up. Reliability is the main objective in lead design, but leads should provide low battery consumption as well. Low coil resistance, with high electrode impedance in steroid-eluting leads, is the standard at present. Low polarization is a desirable property for 2 main reasons: (1) in conjunction with low-threshold leads, it decreases battery consumption; and (2) it allows capture detection and, therefore, safer pacing at low battery consumption. Lead tip design as well as pacing pulse configuration can influence polarization.

Application of cross-linked and hydrolyzed arabinoxylans in baking of model rye bread.

PubMed

Buksa, Krzysztof; Nowotna, Anna; Ziobro, Rafał

2016-02-01

The role of water extractable arabinoxylan with varying molar mass and structure (cross-linked vs. hydrolyzed) in the structure formation of rye bread was examined using a model bread. Instead of the normal flour, the dough contained starch, arabinoxylan and protein, which were isolated from rye wholemeal. It was observed that the applied mixes of these constituents result in a product closely resembling typical rye bread, even if arabinoxylan was modified (by cross-linking or hydrolysis). The levels of arabinoxylan required for bread preparation depended on its modification and mix composition. At 3% protein, the maximum applicable level of poorly soluble cross-linked arabinoxylan was 3%, as higher amounts of this preparation resulted in an extensively viscous dough and diminished bread volume. On the other hand highly soluble, hydrolyzed arabinoxylan could be used at a higher level (6%) together with larger amounts of rye protein (3% or 6%). Further addition of arabinoxylan leads to excessive water absorption, resulting in a decreased viscosity of the dough during baking and insufficient gas retention. Copyright © 2015 Elsevier Ltd. All rights reserved.

Computational Study of Oxidation of Guanine by Singlet Oxygen (1 Δg ) and Formation of Guanine:Lysine Cross-Links.

PubMed

Thapa, Bishnu; Munk, Barbara H; Burrows, Cynthia J; Schlegel, H Bernhard

2017-04-27

Oxidation of guanine in the presence of lysine can lead to guanine-lysine cross-links. The ratio of the C4, C5 and C8 crosslinks depends on the manner of oxidation. Type II photosensitizers such as Rose Bengal and methylene blue can generate singlet oxygen, which leads to a different ratio of products than oxidation by type I photosensitizers or by one electron oxidants. Modeling reactions of singlet oxygen can be quite challenging. Reactions have been explored using CASSCF, NEVPT2, DFT, CCSD(T), and BD(T) calculations with SMD implicit solvation. The spin contamination in open-shell calculations were corrected by Yamaguchi's approximate spin projection method. The addition of singlet oxygen to guanine to form guanine endo- peroxide proceeds step-wise via a zwitterionic peroxyl intermediate. The subsequent barrier for ring closure is smaller than the initial barrier for singlet oxygen addition. Ring opening of the endoperoxide by protonation at C4-O is followed by loss of a proton from C8 and dehydration to produce 8-oxoG ox . The addition of lysine (modelled by methylamine) or water across the C5=N7 double bond of 8-oxoG ox is followed by acyl migration to form the final spiro products. The barrier for methylamine addition is significantly lower than for water addition and should be the dominant reaction channel. These results are in good agreement with the experimental results for the formation of guanine-lysine cross-links by oxidation by type II photosensitizers. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

Adjustable link for kinematic mounting systems

DOEpatents

Hale, Layton C.

1997-01-01

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

Adjustable link for kinematic mounting systems

DOEpatents

Hale, L.C.

1997-07-01

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

HLA-linked rheumatoid arthritis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hasstedt, S.J.; Clegg, D.O.; Ingles, L.

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. Inmore » 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.« less

Photoreactive, core-shell cross-linked/hollow microspheres prepared by delayed addition of cross-linker in dispersion polymerization for antifouling and immobilization of protein.

PubMed

Wang, Shengliu; Yue, Kai; Liu, Lianying; Yang, Wantai

2013-01-01

When dispersion polymerization of styrene (St) had run for 3h, after particle rapidly growing stage, 4,4'-dimethacryloyloxybenzophenone (DMABP) cross-linker was added to reaction system and photoreactive, core(PSt)-shell(Poly(St-co-DMABP)) particles with rich benzophenone (BP) groups on surface were prepared. Polymerization of DMABP could occurred mainly on the preformed core of PSt because its diffusion could be impeded by (1) compactness of particles formed at the moment of cross-linker addition (more than 80% of monomer had been consumed, particles were no longer fully swollen by monomer), (2) reduced polarity of continuous phase, and (3) immediate occurrence of cross-linking. Subsequently, photoreactive, cross-linked hollow particles were yielded by removal of uncross-linked core in THF. SEM and TEM observation demonstrated the formation of core-shell structure and improvement of shell thickness when DMABP content increased. UV-vis spectra analysis on polymer dissolved in THF indicated that there is no polymer of DMABP in core. FTIR spectra analysis and XPS measurement further revealed that BP component on particle surface was enriched when amount of DMABP increased. Finally, an anti-fouling polymer (poly (ethylene glycol), PEG) and protein of mouse IgG was immobilized on particle surface under UV irradiation, as confirmed by FTIR spectra analysis, SEM observation and TMB color reaction. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

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)

Effects of lead-spiked sediments on freshwater bivalve, Hyridella australis: linking organism metal exposure-dose-response.

PubMed

Marasinghe Wadige, Chamani P M; Taylor, Anne M; Maher, William A; Ubrihien, Rodney P; Krikowa, Frank

2014-04-01

Lead entering aquatic ecosystems adsorbs to sediments and has the potential to cause adverse effects on the health of benthic organisms. To evaluate the freshwater bivalve Hyridella australis as a bioindicator for sediment toxicity, their exposure-dose and response to lead contaminated sediments (< 0.01, 205 ± 9 and 419 ± 16 μg/g dry mass) was investigated in laboratory microcosms using 28 day exposures. Despite high concentrations of lead in the sediments, organisms accumulated low concentrations of lead in their tissues after 28 days of exposure (low treatment: 2.2 ± 0.2 μg/g dry mass, high treatment: 4.2 ± 0.1 μg/g dry mass), however, accumulated lead concentrations in lead exposed organisms were two fold (low treatment) and four fold (high treatment) higher than that of unexposed organisms (1.2 ± 0.3 μg/g dry mass). Accumulation of lead by H. australis may have occurred as analogues of calcium and magnesium. Labial palps accumulated significantly more lead than other tissues. Of the lead accumulated in the hepatopancreas, 83%-91% was detoxified and stored in metal rich granules. The proportions and concentrations of lead in this fraction increased with lead exposure, which suggests that lead detoxification pathway plays an important role in metal tolerance of H. australis. The biologically active lead was mainly present in the mitochondrial fraction which increased with lead exposure. Total antioxidant capacity of H. australis significantly decreased while lipid peroxidation and lysosomal membrane destabilation increased with lead exposure. This study showed a clear lead exposure-dose-response relationship and indicates that H. australis would be a good biomonitor for lead in freshwater ecosystems. Copyright © 2014 Elsevier B.V. All rights reserved.

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.

Mechanisms of lead-induced poisoning.

PubMed

Nemsadze, K; Sanikidze, T; Ratiani, L; Gabunia, L; Sharashenidze, T

2009-01-01

Lead is a ubiquitous environmental toxin that is capable of causing numerous acute and chronic circulatory, neurological, hematological, gastrointestinal, reproductive and immunological pathologies. The mechanism of lead induced toxicity is not fully understood. The prime targets to lead toxicity are the heme synthesis enzymes, thiol-containing antioxidants and enzymes (superoxide dismutase, catalase, glutathione peroxidase, glucose 6-phosphate dehydrogenase and antioxidant molecules like GSH). The low blood lead levels are sufficient to inhibit the activity of these enzymes and induce generation of reactive oxygen species and intensification oxidative stress. Oxidative stress plays important role in pathogenesis of lead-induced toxicity and pathogenesis of coupled disease. The primary target of lead toxicity is the central nervous system. There are different cellular, intracellular and molecular mechanisms of lead neurotoxicity: such as induction of oxidative stress, intensification of apoptosis of neurocites, interfering with Ca(2+) dependent enzyme like nitric oxide synthase. Population studies have demonstrated a link between lead exposure and subsequent development of hypertension and cardiovascular disease. The vascular endothelium is now regarded as the main target organ for the toxic effect of lead. Lead affects the vasoactive function of endothelium through the increased production of reactive oxygen species, inactivation of endogenous nitric oxide and downregulation of soluble guanylate cyclase by reactive oxygen species, leading to a limiting nitric oxide availability, impairing nitric oxide signaling. This review summarizes recent findings of the mechanism of the lead-induced toxicity and possibilities of its prevention.

The refining of secondary lead for use in advanced lead-acid batteries

NASA Astrophysics Data System (ADS)

Ellis, Timothy W.; Mirza, Abbas H.

Secondary lead, i.e. material produced by the recycling of lead-acid batteries has become the primary source of lead in much of the world. This has been important to the secondary lead industry as other uses have dwindled, e.g. lead based pigments, chemicals, fuel additives, solders and CRT glasses [1]. Presently, battery manufacturing accounts for greater than 80% of lead consumption while recycled lead accounts for approximately the same market share of lead supply. These two facts strongly demonstrate the battery manufacturing and recycled lead are intimately coupled in everyday life. In this paper we will explore how recycled lead has become the material of choice for battery construction through the development of a recovery and refining process that exceeds the industries requirements. Particular focus will be on addressing the results presented by Prengaman [2] on the effects of contaminant or tramp elements on gassing in lead-acid batteries.

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.

Long-acting follicle-stimulating hormone analogs containing N-linked glycosylation exhibited increased bioactivity compared with o-linked analogs in female rats.

PubMed

Weenen, C; Peña, J E; Pollak, S V; Klein, J; Lobel, L; Trousdale, R K; Palmer, S; Lustbader, E G; Ogden, R T; Lustbader, J W

2004-10-01

The effects of altering the number and type of additional carbohydrate moieties on the pharmacokinetic and pharmacodynamic properties of FSH were examined in this report. A series of single-chain follitropins, containing variable numbers of additional N- (or O-) linked carbohydrates, were designed and expressed in Chinese hamster ovary cells. Proper folding, efficient receptor binding, and signal transduction were confirmed by in vitro assays. Pharmacokinetic and pharmacodynamic parameters were evaluated in immature female Sprague Dawley rats. Increasing the number of glycosylation sites with either N- (or O-) linked moieties extended the elimination half-life as much as 2-fold compared with recombinant human FSH (rhFSH). However, there was a maximum elimination half-life such that further glycosylation provided no additional lengthening of the half-life. Conversely, biopotency, as assessed by inhibin A levels 74 h post injection, and follicle production were significantly higher for the N-linked analogs. Rats stimulated with the longest acting analogs (either N- or O-linked) showed significantly higher ovarian weights than rats receiving a single injection of rhFSH. The analog containing four additional N-linked sites (rhFSH-N4) had the greatest number of large, preovulatory follicles. Although the half-life of rhFSH-N4 displayed no further enhancement beyond the other longest acting analogs, this analog exhibited significantly increased biopotency in rats. This work provides the basis for the generation of a series of reagents potentially useful for therapeutic applications.

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

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. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Security Concepts for Satellite Links

NASA Astrophysics Data System (ADS)

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

2008-08-01

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

Coronary anatomy and the 12-lead electrocardiogram: how to tell who is hurting.

PubMed

Phillips, R A

1997-12-01

Knowledge of how the coronary arteries, cardiac topography, and the 12-lead electrocardiogram (ECG) link together is imperative if the electrical tracing is to be interpreted correctly. Advanced practice nurses not familiar with the ECG may be intimidated by attempts to identify the disease process of myocardial infarctions. This article reviews coronary anatomy and cardiac topography and then links them to the 12-lead ECG for determining areas of myocardial ischemia, injury, and death.

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%.

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.

EarthCube GeoLink: Semantics and Linked Data for the Geosciences

NASA Astrophysics Data System (ADS)

Arko, R. A.; Carbotte, S. M.; Chandler, C. L.; Cheatham, M.; Fils, D.; Hitzler, P.; Janowicz, K.; Ji, P.; Jones, M. B.; Krisnadhi, A.; Lehnert, K. A.; Mickle, A.; Narock, T.; O'Brien, M.; Raymond, L. M.; Schildhauer, M.; Shepherd, A.; Wiebe, P. H.

2015-12-01

The NSF EarthCube initiative is building next-generation cyberinfrastructure to aid geoscientists in collecting, accessing, analyzing, sharing, and visualizing their data and knowledge. The EarthCube GeoLink Building Block project focuses on a specific set of software protocols and vocabularies, often characterized as the Semantic Web and "Linked Data", to publish data online in a way that is easily discoverable, accessible, and interoperable. GeoLink brings together specialists from the computer science, geoscience, and library science domains, and includes data from a network of NSF-funded repositories that support scientific studies in marine geology, marine ecosystems, biogeochemistry, and paleoclimatology. We are working collaboratively with closely-related Building Block projects including EarthCollab and CINERGI, and solicit feedback from RCN projects including Cyberinfrastructure for Paleogeosciences (C4P) and iSamples. GeoLink has developed a modular ontology that describes essential geoscience research concepts; published data from seven collections (to date) on the Web as geospatially-enabled Linked Data using this ontology; matched and mapped data between collections using shared identifiers for investigators, repositories, datasets, funding awards, platforms, research cruises, physical specimens, and gazetteer features; and aggregated the results in a shared knowledgebase that can be queried via a standard SPARQL endpoint. Client applications have been built around the knowledgebase, including a Web/map-based data browser using the Leaflet JavaScript library and a simple query service using the OpenSearch format. Future development will include extending and refining the GeoLink ontology, adding content from additional repositories, developing semi-automated algorithms to enhance metadata, and further work on client applications.

Linking the Teacher Appraisal Process to the School Improvement Plan

ERIC Educational Resources Information Center

Reddekopp, Therese

2007-01-01

If a school improvement plan includes input from all stakeholders and focuses on data-driven processes that are linked to teacher appraisal, it can be powerful in leading the school toward the common mission of achieving student success. Linking the school improvement plan to the teacher appraisal process creates a system whereby all individuals…

Lamellar macular hole in X linked retinoschisis

PubMed Central

Kumar, Vinod; Goel, Neha

2016-01-01

X linked retinoschisis (XLRS) is the most common juvenile onset retinal degeneration. The disorder leads to poor vision in old age. Complications, however, can lead to earlier loss of vision in this condition. This report describes two patients of XLRS, who had presented with poor vision because of having had a lamellar macular hole at a young age. Lamellar macular holes are rare and have never been reported to cause early onset poor vision in XLRS. PMID:27170611

Emotional reactivity and the association between psychopathy-linked narcissism and aggression in detained adolescent boys.

PubMed

Muñoz Centifanti, Luna C; Kimonis, Eva R; Frick, Paul J; Aucoin, Katherine J

2013-05-01

Different patterns of emotional reactivity characterize proactive and reactive functions of aggressive behavior, and theory also suggests a link of both types with narcissism. How people with narcissistic traits respond emotionally to competitive scenarios could influence their aggressiveness. Participants were 85 adolescent boys from a detention center. Several indices of emotional functioning were assessed, including attentional bias to negative emotional stimuli and psychophysiological responding. In addition, we included self-report and laboratory measures of aggression and measures of psychopathy-linked narcissism, callous-unemotional traits, and impulsivity. Psychopathy-linked narcissism was uniquely related to unprovoked aggression (i.e., proactive aggression) and to heightened attention to pictures depicting others' distress. Compared with those scoring low on narcissism, those high on narcissism, who were the least physiologically reactive group, evinced greater proactive aggression, whereas those showing a pattern of coactivation (i.e., sympathetic and parasympathetic autonomic reactivity) evinced greater reactive aggression. Results are consistent with descriptions of narcissistic individuals as being hypervigilant to negative cues and exhibiting poor emotion regulation. These characteristics may lead to aggressive and violent behavior aimed at maintaining dominance over others.

Prediction of missing links and reconstruction of complex networks

NASA Astrophysics Data System (ADS)

Zhang, Cheng-Jun; Zeng, An

2016-04-01

Predicting missing links in complex networks is of great significance from both theoretical and practical point of view, which not only helps us understand the evolution of real systems but also relates to many applications in social, biological and online systems. In this paper, we study the features of different simple link prediction methods, revealing that they may lead to the distortion of networks’ structural and dynamical properties. Moreover, we find that high prediction accuracy is not definitely corresponding to a high performance in preserving the network properties when using link prediction methods to reconstruct networks. Our work highlights the importance of considering the feedback effect of the link prediction methods on network properties when designing the algorithms.

Fragment growing and linking lead to novel nanomolar lactate dehydrogenase inhibitors.

PubMed

Kohlmann, Anna; Zech, Stephan G; Li, Feng; Zhou, Tianjun; Squillace, Rachel M; Commodore, Lois; Greenfield, Matthew T; Lu, Xiaohui; Miller, David P; Huang, Wei-Sheng; Qi, Jiwei; Thomas, R Mathew; Wang, Yihan; Zhang, Sen; Dodd, Rory; Liu, Shuangying; Xu, Rongsong; Xu, Yongjin; Miret, Juan J; Rivera, Victor; Clackson, Tim; Shakespeare, William C; Zhu, Xiaotian; Dalgarno, David C

2013-02-14

Lactate dehydrogenase A (LDH-A) catalyzes the interconversion of lactate and pyruvate in the glycolysis pathway. Cancer cells rely heavily on glycolysis instead of oxidative phosphorylation to generate ATP, a phenomenon known as the Warburg effect. The inhibition of LDH-A by small molecules is therefore of interest for potential cancer treatments. We describe the identification and optimization of LDH-A inhibitors by fragment-based drug discovery. We applied ligand based NMR screening to identify low affinity fragments binding to LDH-A. The dissociation constants (K(d)) and enzyme inhibition (IC(50)) of fragment hits were measured by surface plasmon resonance (SPR) and enzyme assays, respectively. The binding modes of selected fragments were investigated by X-ray crystallography. Fragment growing and linking, followed by chemical optimization, resulted in nanomolar LDH-A inhibitors that demonstrated stoichiometric binding to LDH-A. Selected molecules inhibited lactate production in cells, suggesting target-specific inhibition in cancer cell lines.

X-linked hypophosphatemia attributable to pseudoexons of the PHEX gene.

PubMed

Christie, P T; Harding, B; Nesbit, M A; Whyte, M P; Thakker, R V

2001-08-01

X-linked hypophosphatemia is commonly caused by mutations of the coding region of PHEX (phosphate-regulating gene with homologies to endopeptidases on the X chromosome). However, such PHEX mutations are not detected in approximately one third of X-linked hypophosphatemia patients who may harbor defects in the noncoding or intronic regions. We have therefore investigated 11 unrelated X-linked hypophosphatemia patients in whom coding region mutations had been excluded, for intronic mutations that may lead to mRNA splicing abnormalities, by the use of lymphoblastoid RNA and RT-PCRs. One X-linked hypophosphatemia patient was found to have 3 abnormally large transcripts, resulting from 51-bp, 100-bp, and 170-bp insertions, all of which would lead to missense peptides and premature termination codons. The origin of these transcripts was a mutation (g to t) at position +1268 of intron 7, which resulted in the occurrence of a high quality novel donor splice site (ggaagg to gtaagg). Splicing between this novel donor splice site and 3 preexisting, but normally silent, acceptor splice sites within intron 7 resulted in the occurrences of the 3 pseudoexons. This represents the first report of PHEX pseudoexons and reveals further the diversity of genetic abnormalities causing X-linked hypophosphatemia.

Application of the IEUBK model for linking Children's blood lead with environmental exposure in a mining site, south China.

PubMed

Zhang, Xin-Ying; Carpenter, David O; Song, Yong-Jin; Chen, Ping; Qin, Yaoming; Wei, Ni-Yu; Lin, Shan-Chun

2017-12-01

This study consisted of a site- and age-specific investigation linking children's blood lead level (BLL) to environmental exposures in a historic mining site in south China. A total of 151 children, aged 3-7 years, were included in this study. The geometric mean (GM) BLL was 8.22 μg/dl, indicating an elevated BLL. The Integrated Exposure Uptake Bio-Kinetic (IEUBK) model has proven useful at many sites for study of routes of exposure. Application of the IEUBK model to these children indicated that the GM difference between observed and predicted BLL levels was only 1.07 μg/dl. It was found that the key environmental exposure pathway was soil/dust intake, which contributed 86.3% to the total risk. Younger children had higher BLL than did older children. Therefore, of the various low risk-high benefit solutions, interventions for the children living near the site should be focused on the dust removal and soil remediation. Implementation of the China Eco-village Construction Plan and China New Rural Reconstruction Movement of the government may be a better solution. Copyright © 2017 Elsevier Ltd. All rights reserved.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

Lamellar macular hole in X linked retinoschisis.

PubMed

Kumar, Vinod; Goel, Neha

2016-05-11

X linked retinoschisis (XLRS) is the most common juvenile onset retinal degeneration. The disorder leads to poor vision in old age. Complications, however, can lead to earlier loss of vision in this condition. This report describes two patients of XLRS, who had presented with poor vision because of having had a lamellar macular hole at a young age. Lamellar macular holes are rare and have never been reported to cause early onset poor vision in XLRS. 2016 BMJ Publishing Group Ltd.

Magnetic properties of alluvial soils contaminated with lead, zinc and cadmium

NASA Astrophysics Data System (ADS)

Petrovský, E.; Kapička, A.; Jordanova, N.; Borůvka, L.

2001-09-01

Several proxy methods have been used recently to outline increased levels of pollution. One of them is based on measurements of the concentration of (ferri)magnetic minerals of anthropogenic origin. This method has been used recently in the mapping of both polluted and unpolluted areas. In order to validate this method, a more detailed study of links between magnetic parameters characterising the physical shape of magnetic minerals and concentrations of heavy metals is needed. In this study, we analysed the magnetic characteristics of alluvial soils, formed as a result of several breakdowns of wet deposit sink of ashes from a lead ore smelter. The soils were previously analysed for concentration of lead, zinc and cadmium. Our results show that in this case of a shared source of heavy metals and magnetic minerals, simple measurements of magnetic susceptibility discriminate well between polluted and clean areas. In addition, the concentration pattern agrees with the concentrations of the heavy metals studied in deeper soil layers that were not affected by post-depositional changes due to climate and remediation efforts.

Can Link Analysis Be Applied to Identify Behavioral Patterns in Train Recorder Data?

PubMed

Strathie, Ailsa; Walker, Guy H

2016-03-01

A proof-of-concept analysis was conducted to establish whether link analysis could be applied to data from on-train recorders to detect patterns of behavior that could act as leading indicators of potential safety issues. On-train data recorders capture data about driving behavior on thousands of routine journeys every day and offer a source of untapped data that could be used to offer insights into human behavior. Data from 17 journeys undertaken by six drivers on the same route over a 16-hr period were analyzed using link analysis, and four key metrics were examined: number of links, network density, diameter, and sociometric status. The results established that link analysis can be usefully applied to data captured from on-vehicle recorders. The four metrics revealed key differences in normal driver behavior. These differences have promising construct validity as leading indicators. Link analysis is one method that could be usefully applied to exploit data routinely gathered by on-vehicle data recorders. It facilitates a proactive approach to safety based on leading indicators, offers a clearer understanding of what constitutes normal driving behavior, and identifies trends at the interface of people and systems, which is currently a key area of strategic risk. These research findings have direct applications in the field of transport data monitoring. They offer a means of automatically detecting patterns in driver behavior that could act as leading indicators of problems during operation and that could be used in the proactive monitoring of driver competence, risk management, and even infrastructure design. © 2015, Human Factors and Ergonomics Society.

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 any...

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 any...

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 any...

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 any...

Synthesis and characterisation of cross-linked chitosan composites functionalised with silver and gold nanoparticles for antimicrobial applications

NASA Astrophysics Data System (ADS)

Ryan, Catherine; Alcock, Emma; Buttimer, Finbarr; Schmidt, Michael; Clarke, David; Pemble, Martyn; Bardosova, Maria

2017-12-01

We present a study of a range of cross-linked chitosan composites with potential antimicrobial applications. They were formed by cross-linking chitosan and siloxane networks and by introducing silver and gold nanoparticles (NPs). The aim was to investigate whether adding the metal NPs to the chitosan-siloxane composite would lead to a material with enhanced antimicrobial ability as compared to chitosan itself. The composites were synthesised in hydrogel form with the metal NPs embedded in the cross-linked chitosan network. Spectroscopic and microscopic techniques were employed to investigate the structural properties of the composite and the tensile strength of the structures was measured. It was found that the addition of metal NPs did not influence the mechanical strength of the composite. A crystal violet attachment assay results displayed a significant reduction in the attachment of E. coli to the cross-linked chitosan surfaces. Release profile tests suggest that the metal NPs do not contribute to the overall antimicrobial activity under neutral conditions. The contribution to the mechanical and antimicrobial properties from cross-linking with siloxane is significant, giving rise to a versatile, durable, antimicrobial material suitable for thin film formation, wound dressings or the coating of various surfaces where robustness and antimicrobial control are required.

Synthesis and characterisation of cross-linked chitosan composites functionalised with silver and gold nanoparticles for antimicrobial applications

PubMed Central

Ryan, Catherine; Alcock, Emma; Buttimer, Finbarr; Schmidt, Michael; Clarke, David; Pemble, Martyn; Bardosova, Maria

2017-01-01

Abstract We present a study of a range of cross-linked chitosan composites with potential antimicrobial applications. They were formed by cross-linking chitosan and siloxane networks and by introducing silver and gold nanoparticles (NPs). The aim was to investigate whether adding the metal NPs to the chitosan-siloxane composite would lead to a material with enhanced antimicrobial ability as compared to chitosan itself. The composites were synthesised in hydrogel form with the metal NPs embedded in the cross-linked chitosan network. Spectroscopic and microscopic techniques were employed to investigate the structural properties of the composite and the tensile strength of the structures was measured. It was found that the addition of metal NPs did not influence the mechanical strength of the composite. A crystal violet attachment assay results displayed a significant reduction in the attachment of E. coli to the cross-linked chitosan surfaces. Release profile tests suggest that the metal NPs do not contribute to the overall antimicrobial activity under neutral conditions. The contribution to the mechanical and antimicrobial properties from cross-linking with siloxane is significant, giving rise to a versatile, durable, antimicrobial material suitable for thin film formation, wound dressings or the coating of various surfaces where robustness and antimicrobial control are required. PMID:28804527

Synthesis and characterisation of cross-linked chitosan composites functionalised with silver and gold nanoparticles for antimicrobial applications.

PubMed

Ryan, Catherine; Alcock, Emma; Buttimer, Finbarr; Schmidt, Michael; Clarke, David; Pemble, Martyn; Bardosova, Maria

2017-01-01

We present a study of a range of cross-linked chitosan composites with potential antimicrobial applications. They were formed by cross-linking chitosan and siloxane networks and by introducing silver and gold nanoparticles (NPs). The aim was to investigate whether adding the metal NPs to the chitosan-siloxane composite would lead to a material with enhanced antimicrobial ability as compared to chitosan itself. The composites were synthesised in hydrogel form with the metal NPs embedded in the cross-linked chitosan network. Spectroscopic and microscopic techniques were employed to investigate the structural properties of the composite and the tensile strength of the structures was measured. It was found that the addition of metal NPs did not influence the mechanical strength of the composite. A crystal violet attachment assay results displayed a significant reduction in the attachment of E. coli to the cross-linked chitosan surfaces. Release profile tests suggest that the metal NPs do not contribute to the overall antimicrobial activity under neutral conditions. The contribution to the mechanical and antimicrobial properties from cross-linking with siloxane is significant, giving rise to a versatile, durable, antimicrobial material suitable for thin film formation, wound dressings or the coating of various surfaces where robustness and antimicrobial control are required.

Lead in Drinking Water in Schools and Childcare Facilities

MedlinePlus

... Lead in Drinking Water in Schools and Childcare Facilities Basic Information 3Ts Full Toolkit Partners Related Links ... Best Management Practices For Schools and Child Care Facilities Drinking water best management practices for schools and ...

Synthesis of Ferroelectric Lead Titanate Nanohoneycomb Arrays via Lead Supplement Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Bongsoo; Hong, Seungbum; Ahn, Gun

In this paper, we demonstrate a novel process to convert TiO 2 nanotubes into ferroelectric nanohoneycombs, comprised of vertically aligned PbTiO 3 nanotubes. Tube bottom opening process enabled effective infiltration of lead acetate precursor into the nanotubes. Finally, nanohoneycombs, which were converted via additional lead supplement process, showed uniform conversion and well-defined ferroelectric properties with the effective piezoelectric coefficient of approximately 20 pm/V, which was measured by piezoresponse force microscopy.

Synthesis of Ferroelectric Lead Titanate Nanohoneycomb Arrays via Lead Supplement Process

DOE PAGES

Kim, Bongsoo; Hong, Seungbum; Ahn, Gun; ...

2016-05-14

In this paper, we demonstrate a novel process to convert TiO 2 nanotubes into ferroelectric nanohoneycombs, comprised of vertically aligned PbTiO 3 nanotubes. Tube bottom opening process enabled effective infiltration of lead acetate precursor into the nanotubes. Finally, nanohoneycombs, which were converted via additional lead supplement process, showed uniform conversion and well-defined ferroelectric properties with the effective piezoelectric coefficient of approximately 20 pm/V, which was measured by piezoresponse force microscopy.

Studies of lead exposure on reproductive system: a review of work in China.

PubMed

Xuezhi, J; Youxin, L; Yilan, W

1992-09-01

This paper, based on a review of a series studies conducted in China from 1978 through 1991, describes the possible links between low level lead exposure and the adverse effects on reproductive system. Effects on menstrual status and pregnancy outcome manifested mainly as higher prevalences of menstrual disturbance, spontaneous abortion and threatened abortion in exposed females. Transfer of lead via placenta and human milk was shown by higher lead levels in milk and blood of infant. Impairment of male reproductive function was observed as decreased volume of ejaculation, prolonged latency of semen melting, reduced total sperm count and alive spermatozoa, retarded sperm activity as well as lowered density of semen fluid in exposed male workers with Pb-B over 40 micrograms.dl-1. In addition, poorer performance of WISC-R test was revealed in children with Pb-B level over 30 micrograms.dl-1, and retarded physical development was observed in children with Pb-B over 20 micrograms.dl-1. Therefore, health surveillance including the assessment of adverse effects on reproductive system of both female and male lead exposed workers should not be ignored. Furthermore, safety exposure limit of work place, particularly for female workers of child-bearing age, should be developed.

Lead poisoning prevention for preschool settings: a program template.

PubMed

Saatciler, Eda

2015-01-01

Lead is a naturally occurring metal that has been linked to neurological impairments and insanity since ancient times. It has been used in many products such as paint, pipes, and ceramics and still remains a public hazard. Young children between the ages of 6 months and 6 years with lead-contaminated housing are at the greatest risk for cognitive, neurological, and behavioral health problems. Briefly, lead exposure is around us and it correlates with learning deficits and violent behaviors as these children become adults. It also can cause anemia, abdominal pain, seizure, and death.

Deaths and cardiovascular injuries due to device-assisted implantable cardioverter–defibrillator and pacemaker lead extraction

PubMed Central

Hauser, Robert G.; Katsiyiannis, William T.; Gornick, Charles C.; Almquist, Adrian K.; Kallinen, Linda M.

2010-01-01

Aims An estimated 10 000–15 000 pacemaker and implantable cardioverter–defibrillator (ICD) leads are extracted annually worldwide using specialized tools that disrupt encapsulating fibrous tissue. Additional information is needed regarding the safety of the devices that have been approved for lead extraction. The aim of this study was to determine whether complications due to device-assisted lead extraction might be more hazardous than published data suggest, and whether procedural safety precautions are effective. Methods and results We searched the US Food and Drug Administration's (FDA) Manufacturers and User Defined Experience (MAUDE) database from 1995 to 2008 using the search terms ‘lead extraction and death’ and ‘lead extraction and injury’. Additional product specific searches were performed for the terms ‘death’ and ‘injury’. Between 1995 and 2008, 57 deaths and 48 serious cardiovascular injuries associated with device-assisted lead extraction were reported to the FDA. Owing to underreporting, the FDA database does not contain all adverse events that occurred during this period. Of the 105 events, 27 deaths and 13 injuries occurred in 2007–2008. During these 2 years, 23 deaths were linked with excimer laser or mechanical dilator sheath extractions. The majority of deaths and injuries involved ICD leads, and most were caused by lacerations of the right atrium, superior vena cava, or innominate vein. Overall, 62 patients underwent emergency surgical repair of myocardial perforations and venous lacerations and 35 (56%) survived. Conclusion These findings suggest that device-assisted lead extraction is a high-risk procedure and that serious complications including death may not be mitigated by emergency surgery. However, skilled standby cardiothoracic surgery is essential when performing pacemaker and ICD lead extractions. Although the incidence of these complications is unknown, the results of our study imply that device-assisted lead

Monolithic optical link in silicon-on-insulator CMOS technology.

PubMed

Dutta, Satadal; Agarwal, Vishal; Hueting, Raymond J E; Schmitz, Jurriaan; Annema, Anne-Johan

2017-03-06

This work presents a monolithic laterally-coupled wide-spectrum (350 nm < λ < 1270 nm) optical link in a silicon-on-insulator CMOS technology. The link consists of a silicon (Si) light-emitting diode (LED) as the optical source and a Si photodiode (PD) as the detector; both realized by vertical abrupt n⁺p junctions, separated by a shallow trench isolation composed of silicon dioxide. Medium trench isolation around the devices along with the buried oxide layer provides galvanic isolation. Optical coupling in both avalanche-mode and forward-mode operation of the LED are analyzed for various designs and bias conditions. From both DC and pulsed transient measurements, it is further shown that heating in the avalanche-mode LED leads to a slow thermal coupling to the PD with time constants in the ms range. An integrated heat sink in the same technology leads to a ∼ 6 times reduction in the change in PD junction temperature per unit electrical power dissipated in the avalanche-mode LED. The analysis paves way for wide-spectrum optical links integrated in smart power technologies.

Identifying housing that poisons: a critical step in eliminating childhood lead poisoning.

PubMed

Reyes, Nimia L; Wong, Lee-Yang; MacRoy, Patrick M; Curtis, Gerald; Meyer, Pamela A; Evens, Anne; Brown, Mary Jean

2006-01-01

The purpose of our study was to develop a method to identify and prioritize "high-risk" buildings in Chicago that could be targeted for childhood lead poisoning prevention activities. We defined "high-risk" buildings as those where multiple children younger than 6 years with elevated blood lead levels (BLLs) had lived and where lead hazards were previously identified on environmental inspection. By linking 1997-2003 Chicago elevated blood lead surveillance, environmental inspection, and building footprint data, we found that 49,362 children younger than 6 years with elevated BLLs lived at 30,742 buildings. Of those, 67 were "high-risk" buildings and these were associated with 994 children with elevated BLLs. On average, 15 children with elevated BLLs had lived in each building (range: 10-53, median: 13). Almost two thirds (n = 43) of the high-risk buildings had two or more referrals for inspection to the same apartment or housing unit; of those, 40 percent (n = 17) failed to maintain lead-safe status after compliance. Linking blood lead surveillance, environmental inspection, and building footprint databases allowed us to identify individual high-risk buildings. This approach prioritizes lead hazard control efforts and may help health, housing, and environmental agencies in targeting limited resources to increase lead-safe housing for children.

Hamilton's missing link.

PubMed

van Veelen, Matthijs

2007-06-07

Hamilton's famous rule was presented in 1964 in a paper called "The genetical theory of social behaviour (I and II)", Journal of Theoretical Biology 7, 1-16, 17-32. The paper contains a mathematical genetical model from which the rule supposedly follows, but it does not provide a link between the paper's central result, which states that selection dynamics take the population to a state where mean inclusive fitness is maximized, and the rule, which states that selection will lead to maximization of individual inclusive fitness. This note provides a condition under which Hamilton's rule does follow from his central result.

Aging and cancer: are sirtuins the link?

PubMed

Rodriguez, Ramon M; Fraga, Mario F

2010-06-01

Classically, aging has been defined as a general degeneration process that leads to the loss of corporal function. The loss of function caused by degeneration limits the maximum lifespan of all organisms and is linked to disease and cancer. Nevertheless, the molecular mechanisms behind aging and their connection to cancer are not well understood. NAD-dependent protein deacetylase enzymes, sirtuins, are emerging as a novel molecular link between aging and cancer due to their specific role in cell cycle regulation, antistress response and cell survival. This article reviews the contribution of sirtuins and environmental factors to ontogenic development, senescence and cancer.

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...

X‐linked retinoschisis: an update

PubMed Central

Sikkink, Stephen K; Biswas, Susmito; Parry, Neil R A; Stanga, Paulo E; Trump, Dorothy

2007-01-01

X‐linked retinoschisis is the leading cause of macular degeneration in males and leads to splitting within the inner retinal layers leading to visual deterioration. Many missense and protein truncating mutations have now been identified in the causative retinoschisis gene (RS1) which encodes a 224 amino acid secreting retinal protein, retinoschisin. Retinoschisin octamerises is implicated in cell–cell interactions and cell adhesion perhaps by interacting with β2 laminin. Mutations cause loss of retinoschisin function by one of the three mechanisms: by interfering with protein secretion, by preventing its octamerisation or by reducing function in the secreted octamerised protein. The development of retinoschisis mouse models have provided a model system that closely resembles the human disease. Recent reports of RS1 gene transfer to these models and the sustained restoration of some retinal function and morphology suggest gene replacement may be a possible future therapy for patients. PMID:17172462

Strengthening links between waterfowl research and management

USGS Publications Warehouse

Roberts, Anthony J.; Eadie, John M.; Howerter, David; Johnson, Fred A.; Nichols, James; Runge, Michael C.; Vrtiska, Mark; Williams, Byron K.

2018-01-01

Waterfowl monitoring, research, regulation, and adaptive planning are leading the way in supporting science-informed wildlife management. However, increasing societal demands on natural resources have created a greater need for adaptable and successful linkages between waterfowl science and management. We presented a special session at the 2016 North American Duck Symposium, Annapolis, Maryland, USA on the successes and challenges of linking research and management in waterfowl conservation, and we summarize those thoughts in this commentary. North American waterfowl management includes a diversity of actions including management of harvest and habitat. Decisions for waterfowl management are structured using decision analysis by incorporating stakeholder values into formal objectives, identifying research relevant to objectives, integrating scientific knowledge, and choosing an optimal strategy with respect to objectives. Recently, the consideration of the value of information has been proposed as a means to evaluate the utility of research designed to meet objectives. Despite these advances, the ability to conduct waterfowl research with direct management application may be increasingly difficult in research institutions for several reasons including reduced funding for applied research and the lower perceived value of applied versus theoretical research by some university academics. In addition, coordination between researchers and managers may be logistically constrained, and communication may be ineffective between the 2 groups. Strengthening these links would help develop stronger and more coordinated approaches for the conservation of waterfowl and the wetlands upon which they depend.

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.

Improving the Simulation of Sea Ice Lead Conditions and Turbulent Fluxes Using RGPS Products and Merged RADARSAT, AVHRR and MODIS Data

NASA Technical Reports Server (NTRS)

Maslanik, James A.

2004-01-01

The importance of sea ice leads in the ice-ocean-atmosphere system lies in the fact that each of the boxes in the 'surface processes' interface in this diagram is closely linked to lead conditions. For example, heat, moisture and salt exchange between the Ocean and atmosphere within the ice pack occur nearly entirely through leads. The shear, divergence and convergence associated with lead formation and closure alter surface and basal roughness and topography, which in turn affects momentum transfer in the atmosphere and ocean boundary layers, and modifies the accumulation of snow on the ice surface, which then affects heat conduction and summertime albedo. In addition to providing openings for loss of heat and moisture fluxes to the atmosphere, leads absorb solar energy, which is used to melt ice and is transmitting to the underlying ocean. Given that leads dominate the ice-ocean interface in this manner, then it stands to reason that focusing on lead treatments within models can identify performance limitations of models and yield routes for significant improvements.

Cross-linking of cell surface amyloid precursor protein leads to increased β-amyloid peptide production in hippocampal neurons: implications for Alzheimer's disease.

PubMed

Lefort, Roger; Pozueta, Julio; Shelanski, Michael

2012-08-01

The accumulation of the β-amyloid peptide (Aβ) in Alzheimer's disease (AD) is thought to play a causative role in triggering synaptic dysfunction in neurons, leading to their eventual demise through apoptosis. Aβ is produced and secreted upon sequential cleavage of the amyloid precursor protein (APP) by β-secretases and γ-secretases. However, while Aβ levels have been shown to be increased in the brains of AD patients, little is known about how the cleavage of APP and the subsequent generation of Aβ is influenced, or whether the cleavage process changes over time. It has been proposed that Aβ can bind APP and promote amyloidogenic processing of APP, further enhancing Aβ production. Proof of this idea has remained elusive because a clear mechanism has not been identified, and the promiscuous nature of Aβ binding complicates the task of demonstrating the idea. To work around these problems, we used an antibody-mediated approach to bind and cross-link cell-surface APP in cultured rat primary hippocampal neurons. Here we show that cross-linking of APP is sufficient to raise the levels of Aβ in viable neurons with a concomitant increase in the levels of the β-secretase BACE1. This appears to occur as a result of a sorting defect that stems from the caspase-3-mediated inactivation of a key sorting adaptor protein, namely GGA3, which prevents the lysosomal degradation of BACE1. Together, our data suggest the occurrence of a positive pathogenic feedback loop involving Aβ and APP in affected neurons possibly allowing Aβ to spread to nearby healthy neurons.

Lead-related complications after DDD pacemaker implantation.

PubMed

Dębski, Maciej; Ulman, Mateusz; Ząbek, Andrzej; Boczar, Krzysztof; Haberka, Kazimierz; Kuniewicz, Marcin; Lelakowski, Jacek; Małecka, Barbara

2018-04-10

Pacing leads remain the weakest link in pacemaker systems despite advances in manufacturing technology. To assess the long-term pacing lead performance in an unselected real-life cohort following primary DDD pacing system implantation. A single-centre retrospective analysis of patients who underwent DDD pacing system implantation between October 1984 and December 2014 and were followed up until August 2016 was conducted. The inclusion criterion was at least one follow-up visit following post-implant discharge. The performance of each atrial and ventricular lead implanted was evaluated during the follow-up period, and the incidence of and predictive factors for lead dislodgement and failure were analysed. The data of 3771 patients and 24431.8 patient-years of follow-up were analysed. The mean follow-up of patients was 77.7 ± 61.8 months. During the study period, 7887 transvenous atrial and right ventricular pacing leads were implanted. Lead dislodgement occurred in 94 (1.2%) leads [92 (2.4%) patients], perforation in 11 (0.1%) leads [10 (0.3%) patients] and lead failure in 329 (4.2%) leads [275 (7.3%) patients]. Atrial lead position was a predictive factor for lead dislodgement, while age at implantation, polyurethane 80A insulation, subclavian vein access, unipolar lead construction and lead manufacturer were multivariate predictors of lead failure. Leads with polyurethane 80A insulation, unipolar construction and implantation via subclavian vein puncture exhibited the worst long-term performance.

Leading High School Transformation for College and Career Success: A Guide for Developing a System of Linked Learning Pathways

ERIC Educational Resources Information Center

Stearns, Roman

2014-01-01

This ConnectEd Guide for Developing a System of Linked Learning Pathways will introduce school district leaders and their community partners to Linked Learning and a system of quality pathways that can transform high schools, instructional practice, and the student experience. Not intended to be prescriptive, this document can and should be…

External Link Policy | Cancer Prevention Fellowship Program

Cancer.gov

The following graphic notice means that you are leaving the CPFP Web site: This external link provides additional information that is consistent with the intended purpose of CPFP. 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 a

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.more » 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.« less

The void nucleation mechanism within lead phase during spallation of leaded brass

NASA Astrophysics Data System (ADS)

Yang, Yang; Wang, Can; Chen, Xingzhi; Chen, Kaiguo; Hu, Haibo; Fu, Yanan

2018-07-01

The incipient spall behaviours of Cu-34%Zn-3%Pb leaded brass samples with annealed and cryogenic-treated conditions were loaded using one-stage light gas gun experiments. The effect of Pb-phase on dynamic damage nucleation in leaded brass specimens was investigated by means of optical microscopy, scanning electron microscopy and x-ray computer tomography. It was found that the voids of incipient spall were mainly nucleated in the interior of the lead (no tensile stress would be produced within lead according to the impact theory) instead of nucleated at the phase interface as expected by quasi-static damage fracture theory. A nucleation model is proposed in the present work that is the asymmetry high compression zones in the centre of the lead-phase were formed by the rarefaction wave convergence effects of matrix/quasi-spherical lead interface, which caused adiabatic temperature rise that exceeded melting point of lead due to severe plastic deformation, finally led to local melting and void nucleation. In addition, the spall strength and damage rate increased with the increase in the Pb-phase number.

Cross-linked polyimides for integrated optics

NASA Astrophysics Data System (ADS)

Singer, Kenneth D.; Kowalczyk, Tony C.; Nguyen, Hung D.; Beuhler, Allyson J.; Wargowski, David A.

1997-01-01

We have investigated a promising class of polyimide materials for both passive and active electro-optic devices, namely crosslinkable polyimides. These fluorinated polyimides are soluble in the imidized form and are both thermally and photo-crosslinkable leading to easy processability into waveguide structures and the possibility of stable electro-optic properties. We have fabricated channel and slab waveguides and investigated the mechanism of optical propagation loss using photothermal deflection spectroscopy and waveguide loss spectroscopy, and found the losses to arise from residual absorption due to the formation of charge transfer states. The absorption is inhibited by fluorination leading to propagation losses as low as 0.3 dB/cm in the near infrared. Because of the ability to photocrosslink, channel waveguides are fabricated using a simple wet-etch process. Channel waveguides so formed are observed to have no excess loss over slab structures. Solubility followed by thermal cross-linking allows the formation of multilayer structures. We have produced electro-optic polymers by doping with the nonlinear optical chromophores, DCM and DADC; and a process of concurrent poling and thermal crosslinking. Multilayer structures have been investigated and poling fields optimized in the active layer by doping the cladding with an anti-static agent. The high glass-transition temperature and cross-linking leads to very stable electro-optic properties. We are currently building electro-optic modulators based on these materials. Progress and results in this area also are reported.

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). ...

Cancer-related inflammation, the seventh hallmark of cancer: links to genetic instability.

PubMed

Colotta, Francesco; Allavena, Paola; Sica, Antonio; Garlanda, Cecilia; Mantovani, Alberto

2009-07-01

Inflammatory conditions in selected organs increase the risk of cancer. An inflammatory component is present also in the microenvironment of tumors that are not epidemiologically related to inflammation. Recent studies have begun to unravel molecular pathways linking inflammation and cancer. In the tumor microenvironment, smoldering inflammation contributes to proliferation and survival of malignant cells, angiogenesis, metastasis, subversion of adaptive immunity, reduced response to hormones and chemotherapeutic agents. Recent data suggest that an additional mechanism involved in cancer-related inflammation (CRI) is induction of genetic instability by inflammatory mediators, leading to accumulation of random genetic alterations in cancer cells. In a seminal contribution, Hanahan and Weinberg [(2000) Cell, 100, 57-70] identified the six hallmarks of cancer. We surmise that CRI represents the seventh hallmark.

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.

NASA OSMA NDE Program Additive Manufacturing Foundational Effort

NASA Technical Reports Server (NTRS)

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

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.

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.

Heterogeneous Link Weight Promotes the Cooperation in Spatial Prisoner's Dilemma

NASA Astrophysics Data System (ADS)

Ma, Zhi-Qin; Xia, Cheng-Yi; Sun, Shi-Wen; Wang, Li; Wang, Huai-Bin; Wang, Juan

The spatial structure has often been identified as a prominent mechanism that substantially promotes the cooperation level in prisoner's dilemma game. In this paper we introduce a weighting mechanism into the spatial prisoner's dilemma game to explore the cooperative behaviors on the square lattice. Here, three types of weight distributions: exponential, power-law and uniform distributions are considered, and the weight is assigned to links between players. Through large-scale numerical simulations we find, compared with the traditional spatial game, that this mechanism can largely enhance the frequency of cooperators. For most ranges of b, we find that the power-law distribution enables the highest promotion of cooperation and the uniform one leads to the lowest enhancement, whereas the exponential one lies often between them. The great improvement of cooperation can be caused by the fact that the distributional link weight yields inhomogeneous interaction strength among individuals, which can facilitate the formation of cooperative clusters to resist the defector's invasion. In addition, the impact of amplitude of the undulation of weight distribution and noise strength on cooperation is also investigated for three kinds of weight distribution. Current researches can aid in the further understanding of evolutionary cooperation in biological and social science.

Elevated lead levels from e-waste exposure are linked to decreased olfactory memory in children.

PubMed

Zhang, Bo; Huo, Xia; Xu, Long; Cheng, Zhiheng; Cong, Xiaowei; Lu, Xueling; Xu, Xijin

2017-12-01

Lead (Pb) is a developmental neurotoxicant and can cause abnormal development of the nervous system in children. Hence, the aim of this study was to investigate the effect of Pb exposure on child olfactory memory by correlating the blood Pb levels of children in Guiyu with olfactory memory tests. We recruited 61 preschool children, 4- to 7-years of age, from Guiyu and 57 children from Haojiang. The mean blood Pb level of Guiyu children was 9.40 μg/dL, significantly higher than the 5.04 μg/dL mean blood Pb level of Haojiang children. In addition, approximately 23% of Guiyu children had blood Pb levels exceeding 10.00 μg/dL. The correlation analysis showed that blood Pb levels in children highly correlated with e-waste contact (r s  = 0.393). Moreover, the mean concentration of serum BDNF in Guiyu children (35.91 ng/ml) was higher than for Haojiang (28.10 ng/ml) and was positively correlated with blood Pb levels. Both item and source olfactory memory tests at 15 min, 5 h and 24 h after odor exposure showed that scores were lower in Guiyu children indicative of reduced olfactory memory in Guiyu children. Olfactory memory tests scores negatively correlated with blood Pb and serum BDNF levels, but were positively associated with parental education levels. At the same time, scores of both tests on children in the high blood Pb level group (blood Pb levels > 5.00 μg/dL) were lower than those in the low blood Pb level group (blood Pb levels ≤ 5.00 μg/dL), implying that Pb exposure decreases olfactory memory in children. Our findings suggest that Pb exposure in e-waste recycling and dismantling areas could result in an increase in serum BDNF level and a decrease in child olfactory memory, in addition, BDNF might be involved in olfactory memory impairment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lead Time Study,

DTIC Science & Technology

1982-05-01

1979, the number of titanium fabrications dropped from 16 to 4, primarily because of the sponge shortage and EPA and OSHA requirements. Non-military...East - Taiwan, Korea, Singapore, Malaysia and Hong Kong. In addition, a significant amount of ceramic parts, lead frames and high technology

X-linked cataract and Nance-Horan syndrome are allelic disorders.

PubMed

Coccia, Margherita; Brooks, Simon P; Webb, Tom R; Christodoulou, Katja; Wozniak, Izabella O; Murday, Victoria; Balicki, Martha; Yee, Harris A; Wangensteen, Teresia; Riise, Ruth; Saggar, Anand K; Park, Soo-Mi; Kanuga, Naheed; Francis, Peter J; Maher, Eamonn R; Moore, Anthony T; Russell-Eggitt, Isabelle M; Hardcastle, Alison J

2009-07-15

Nance-Horan syndrome (NHS) is an X-linked developmental disorder characterized by congenital cataract, dental anomalies, facial dysmorphism and, in some cases, mental retardation. Protein truncation mutations in a novel gene (NHS) have been identified in patients with this syndrome. We previously mapped X-linked congenital cataract (CXN) in one family to an interval on chromosome Xp22.13 which encompasses the NHS locus; however, no mutations were identified in the NHS gene. In this study, we show that NHS and X-linked cataract are allelic diseases. Two CXN families, which were negative for mutations in the NHS gene, were further analysed using array comparative genomic hybridization. CXN was found to be caused by novel copy number variations: a complex duplication-triplication re-arrangement and an intragenic deletion, predicted to result in altered transcriptional regulation of the NHS gene. Furthermore, we also describe the clinical and molecular analysis of seven families diagnosed with NHS, identifying four novel protein truncation mutations and a novel large deletion encompassing the majority of the NHS gene, all leading to no functional protein. We therefore show that different mechanisms, aberrant transcription of the NHS gene or no functional NHS protein, lead to different diseases. Our data highlight the importance of copy number variation and non-recurrent re-arrangements leading to different severity of disease and describe the potential mechanisms involved.

X-linked cataract and Nance-Horan syndrome are allelic disorders

PubMed Central

Coccia, Margherita; Brooks, Simon P.; Webb, Tom R.; Christodoulou, Katja; Wozniak, Izabella O.; Murday, Victoria; Balicki, Martha; Yee, Harris A.; Wangensteen, Teresia; Riise, Ruth; Saggar, Anand K.; Park, Soo-Mi; Kanuga, Naheed; Francis, Peter J.; Maher, Eamonn R.; Moore, Anthony T.; Russell-Eggitt, Isabelle M.; Hardcastle, Alison J.

2009-01-01

Nance-Horan syndrome (NHS) is an X-linked developmental disorder characterized by congenital cataract, dental anomalies, facial dysmorphism and, in some cases, mental retardation. Protein truncation mutations in a novel gene (NHS) have been identified in patients with this syndrome. We previously mapped X-linked congenital cataract (CXN) in one family to an interval on chromosome Xp22.13 which encompasses the NHS locus; however, no mutations were identified in the NHS gene. In this study, we show that NHS and X-linked cataract are allelic diseases. Two CXN families, which were negative for mutations in the NHS gene, were further analysed using array comparative genomic hybridization. CXN was found to be caused by novel copy number variations: a complex duplication–triplication re-arrangement and an intragenic deletion, predicted to result in altered transcriptional regulation of the NHS gene. Furthermore, we also describe the clinical and molecular analysis of seven families diagnosed with NHS, identifying four novel protein truncation mutations and a novel large deletion encompassing the majority of the NHS gene, all leading to no functional protein. We therefore show that different mechanisms, aberrant transcription of the NHS gene or no functional NHS protein, lead to different diseases. Our data highlight the importance of copy number variation and non-recurrent re-arrangements leading to different severity of disease and describe the potential mechanisms involved. PMID:19414485

[Complications and postoperative therapeutic strategies in cross-linking].

PubMed

Kohlhaas, M

2017-08-01

The reduced corneal mechanical stability in keratoconus and similar collagen diseases can lead to a progressive and irregular corneal shape and decrease of visual acuity. A progression of keratectatic diseases can be shown with corneal topography. Keratoconus can be treated by photo-oxidative cross-linking of the corneal collagen. In order to achieve a high absorption of irradiation energy in the cornea, riboflavin at a concentration of 0.1% and UVA light at a wavelength of 370 nm corresponding to the relative maximum absorption of riboflavin (vitamin B2) are used. Evidence for corneal cross-linking are the increase of biomechanical stiffness, the increased resistance against enzymatic degradation, a higher shrinkage temperature, a lower swelling rate and an increased diameter of collagen fibers. The currently available data demonstrate that the therapeutic cross-linking procedure is safe when respecting the important theoretical and clinical parameters and that a progression of the keratoconus can be avoided. In 80% of cases an average levelling of the curvature of approximately 2 dpt can be achieved, which leads not only to stabilization but also to an increase in visual acuity of approximately 1.2 lines. In a Cochrane review from 2015 publications about complications and results were reviewed. Complication rates ranged from 1-10% depending on the initial situation, comorbidities and stage of the keratoconus. The most important complications are early epithelial wound healing problems as well as extremely rare perforations. Corneal cross-linking is a well-established and safe procedure but is not free of complications.

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.

Baby Teeth Link Autism and Heavy Metals, NIH Study Suggests

MedlinePlus

... Release Thursday, June 1, 2017 Baby teeth link autism and heavy metals, NIH study suggests Cross-section ... Sinai Health System Baby teeth from children with autism contain more toxic lead and less of the ...

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

How Understanding the Role of an Additive Can Lead to an Improved Synthetic Protocol without an Additive: Organocatalytic Synthesis of Chiral Diarylmethyl Alkynes.

PubMed

Chen, Min; Sun, Jianwei

2017-09-18

The use of additives for organic synthesis has become a common tactic to improve the outcome of organic reactions. Herein, by using an organocatalytic process for the synthesis of chiral diarylmethyl alkynes as a platform, we describe how an additive is involved in the improvement of the process. The evolution of an excellent synthetic protocol has been achieved in three stages, from 1) initially no catalyst turnover, to 2) good conversion and enantioselectivity with a superior additive, and eventually 3) even better efficiency and selectivity without an additive. This study is an important and rare demonstration that understanding the role of additive can be so beneficial as to obviate the need for the additive. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Quest for Converting Biorenewable Bifunctional α-Methylene-γ-butyrolactone into Degradable and Recyclable Polyester: Controlling Vinyl-Addition/Ring-Opening/Cross-Linking Pathways.

PubMed

Tang, Xiaoyan; Hong, Miao; Falivene, Laura; Caporaso, Lucia; Cavallo, Luigi; Chen, Eugene Y-X

2016-11-02

α-Methylene-γ-butyrolactone (MBL), a naturally occurring and biomass-sourced bifunctional monomer, contains both a highly reactive exocyclic C═C bond and a highly stable five-membered γ-butyrolactone ring. Thus, all previous work led to exclusive vinyl-addition polymerization (VAP) product P(MBL) VAP . Now, this work reverses this conventional chemoselectivity to enable the first ring-opening polymerization (ROP) of MBL, thereby producing exclusively unsaturated polyester P(MBL) ROP with M n up to 21.0 kg/mol. This elusive goal was achieved through uncovering the thermodynamic, catalytic, and processing conditions. A third reaction pathway has also been discovered, which is a crossover propagation between VAP and ROP processes, thus affording cross-linked polymer P(MBL) CLP . The formation of the three types of polymers, P(MBL) VAP , P(MBL) CLP , and P(MBL) ROP , can be readily controlled by adjusting the catalyst (La)/initiator (ROH) ratio, which is determined by the unique chemoselectivity of the La-X (X = OR, NR 2 , R) group. The resulting P(MBL) ROP is degradable and can be readily postfunctionalized into cross-linked or thiolated materials but, more remarkably, can also be fully recycled back to its monomer thermochemically. Computational studies provided the theoretical basis for, and a mechanistic understanding of, the three different polymerization processes and the origin of the chemoselectivity.

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:…

X-Linked Glomerulopathy Due to COL4A5 Founder Variant.

PubMed

Barua, Moumita; John, Rohan; Stella, Lorenzo; Li, Weili; Roslin, Nicole M; Sharif, Bedra; Hack, Saidah; Lajoie-Starkell, Ginette; Schwaderer, Andrew L; Becknell, Brian; Wuttke, Matthias; Köttgen, Anna; Cattran, Daniel; Paterson, Andrew D; Pei, York

2018-03-01

Alport syndrome is a rare hereditary disorder caused by rare variants in 1 of 3 genes encoding for type IV collagen. Rare variants in COL4A5 on chromosome Xq22 cause X-linked Alport syndrome, which accounts for ∼80% of the cases. Alport syndrome has a variable clinical presentation, including progressive kidney failure, hearing loss, and ocular defects. Exome sequencing performed in 2 affected related males with an undefined X-linked glomerulopathy characterized by global and segmental glomerulosclerosis, mesangial hypercellularity, and vague basement membrane immune complex deposition revealed a COL4A5 sequence variant, a substitution of a thymine by a guanine at nucleotide 665 (c.T665G; rs281874761) of the coding DNA predicted to lead to a cysteine to phenylalanine substitution at amino acid 222, which was not seen in databases cataloguing natural human genetic variation, including dbSNP138, 1000 Genomes Project release version 01-11-2004, Exome Sequencing Project 21-06-2014, or ExAC 01-11-2014. Review of the literature identified 2 additional families with the same COL4A5 variant leading to similar atypical histopathologic features, suggesting a unique pathologic mechanism initiated by this specific rare variant. Homology modeling suggests that the substitution alters the structural and dynamic properties of the type IV collagen trimer. Genetic analysis comparing members of the 3 families indicated a distant relationship with a shared haplotype, implying a founder effect. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Impaired Lysosomal Trimming of N-Linked Oligosaccharides Leads to Hyperglycosylation of Native Lysosomal Proteins in Mice with α-Mannosidosis ▿

PubMed Central

Damme, Markus; Morelle, Willy; Schmidt, Bernhard; Andersson, Claes; Fogh, Jens; Michalski, Jean-Claude; Lübke, Torben

2010-01-01

α-Mannosidosis is caused by the genetic defect of the lysosomal α-d-mannosidase (LAMAN), which is involved in the breakdown of free α-linked mannose-containing oligosaccharides originating from glycoproteins with N-linked glycans, and thus manifests itself in an extensive storage of mannose-containing oligosaccharides. Here we demonstrate in a model of mice with α-mannosidosis that native lysosomal proteins exhibit elongated N-linked oligosaccharides as shown by two-dimensional difference gel electrophoresis, deglycosylation assays, and mass spectrometry. The analysis of cathepsin B-derived oligosaccharides revealed a hypermannosylation of glycoproteins in mice with α-mannosidosis as indicated by the predominance of extended Man3GlcNAc2 oligosaccharides. Treatment with recombinant human α-mannosidase partially corrected the hyperglycosylation of lysosomal proteins in vivo and in vitro. These data clearly demonstrate that LAMAN is involved not only in the lysosomal catabolism of free oligosaccharides but also in the trimming of asparagine-linked oligosaccharides on native lysosomal proteins. PMID:19884343

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.

Additional electrodes on the Quartet™ LV lead provide more programmable pacing options than bipolar and tripolar equivalents.

PubMed

O'Donnell, David; Sperzel, Johannes; Thibault, Bernard; Rinaldi, Christopher A; Pappone, Carlo; Gutleben, Klaus-Jürgen; Leclercq, Christopher; Razavi, Hedi; Ryu, Kyungmoo; Mcspadden, Luke C; Fischer, Avi; Tomassoni, Gery

2017-04-01

The aim of this study was to evaluate any benefits to the number of viable pacing vectors and maximal spatial coverage with quadripolar left ventricular (LV) leads when compared with tripolar and bipolar equivalents in patients receiving cardiac resynchronization therapy (CRT). A meta-analysis of five previously published clinical trials involving the Quartet™ LV lead (St Jude Medical, St Paul, MN, USA) was performed to evaluate the number of viable pacing vectors defined as capture thresholds ≤2.5 V and no phrenic nerve stimulation and maximal spatial coverage of viable vectors in CRT patients at pre-discharge (n = 370) and first follow-up (n = 355). Bipolar and tripolar lead configurations were modelled by systematic elimination of two and one electrode(s), respectively, from the Quartet lead. The Quartet lead with its four pacing electrodes exhibited the greatest number of pacing vectors per patient when compared with the best bipolar and the best tripolar modelled equivalents. Similarly, the Quartet lead provided the highest spatial coverage in terms of the distance between two furthest viable pacing cathodes when compared with the best bipolar and the best tripolar configurations (P < 0.05). Among the three modelled bipolar configurations, the lead configuration with the two most distal electrodes resulted in the highest number of viable pacing vectors. Among the four modelled tripolar configurations, elimination of the second proximal electrode (M3) resulted in the highest number of viable pacing options per patient. There were no significant differences observed between pre-discharge and first follow-up analyses. The Quartet lead with its four electrodes and the capability to pace from four anatomical locations provided the highest number of viable pacing vectors at pre-discharge and first follow-up visits, providing more flexibility in device programming and enabling continuation of CRT in more patients when compared with bipolar and tripolar

Towards force spectroscopy of single tip-link bonds

NASA Astrophysics Data System (ADS)

Koussa, Mounir A.; Sotomayor, Marcos; Wong, Wesley P.; Corey, David P.

2015-12-01

Inner-ear mechanotransduction relies on tip links, fine protein filaments made of cadherin-23 and protocadherin-15 that convey tension to mechanosensitive channels at the tips of hair-cell stereocilia. The tip-link cadherins are thought to form a heterotetrameric complex, with two cadherin-23 molecules forming the upper part of the filament and two protocadherin-15 molecules forming the lower end. The interaction between cadherin-23 and protocadherin-15 is mediated by their N-terminal tips. Missense mutations that modify the interaction interface impair binding and lead to deafness. Molecular dynamics simulations predict that the tip-link bond is mechanically strong enough to withstand forces in hair cells, but its experimentally determined strength is unknown. We have developed molecular tools to facilitate single-molecule force spectroscopy on the tip link bond. Self-assembling DNA nanoswitches are functionalized with the interacting tips of cadherin-23 and protocadherin-15 using the enzyme sortase under conditions that preserve protein function. These tip link nanoswitches are designed to provide a signature force-extension profile. This molecular signature should allow us to identify single-molecule rupture events in pulling experiments.

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...

O-Linked N-Acetylglucosamine Cycling Regulates Mitotic Spindle Organization*

PubMed Central

Tan, Ee Phie; Caro, Sarah; Potnis, Anish; Lanza, Christopher; Slawson, Chad

2013-01-01

Any defects in the correct formation of the mitotic spindle will lead to chromosomal segregation errors, mitotic arrest, or aneuploidy. We demonstrate that O-linked N-acetylglucosamine (O-GlcNAc), a post-translational modification of serine and threonine residues in nuclear and cytoplasmic proteins, regulates spindle function. In O-GlcNAc transferase or O-GlcNAcase gain of function cells, the mitotic spindle is incorrectly assembled. Chromosome condensation and centrosome assembly is impaired in these cells. The disruption in spindle architecture is due to a reduction in histone H3 phosphorylation by Aurora kinase B. However, gain of function cells treated with the O-GlcNAcase inhibitor Thiamet-G restored the assembly of the spindle and partially rescued histone phosphorylation. Together, these data suggest that the coordinated addition and removal of O-GlcNAc, termed O-GlcNAc cycling, regulates mitotic spindle organization and provides a potential new perspective on how O-GlcNAc regulates cellular events. PMID:23946484

The intersection of aggregate-level lead exposure and crime.

PubMed

Boutwell, Brian B; Nelson, Erik J; Emo, Brett; Vaughn, Michael G; Schootman, Mario; Rosenfeld, Richard; Lewis, Roger

2016-07-01

Childhood lead exposure has been associated with criminal behavior later in life. The current study aimed to analyze the association between elevated blood lead levels (n=59,645) and crime occurrence (n=90,433) across census tracts within St. Louis, Missouri. Longitudinal ecological study. Saint Louis, Missouri. Blood lead levels. Violent, Non-violent, and total crime at the census tract level. Spatial statistical models were used to account for the spatial autocorrelation of the data. Greater lead exposure at the census-tract level was associated with increased violent, non-violent, and total crime. In addition, we examined whether non-additive effects existed in the data by testing for an interaction between lead exposure and concentrated disadvantage. Some evidence of a negative interaction emerged, however, it failed to reach traditional levels of statistical significance (supplementary models, however, revealed a similar negative interaction that was significant). More precise measurements of lead exposure in the aggregate, produced additional evidence that lead is a potent predictor of criminal outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

Enhancing robustness of interdependent network by adding connectivity and dependence links

NASA Astrophysics Data System (ADS)

Cui, Pengshuai; Zhu, Peidong; Wang, Ke; Xun, Peng; Xia, Zhuoqun

2018-05-01

Enhancing robustness of interdependent networks by adding connectivity links has been researched extensively, however, few of them are focusing on adding both connectivity and dependence links to enhance robustness. In this paper, we aim to study how to allocate the limited costs reasonably to add both connectivity and dependence links. Firstly, we divide the attackers into stubborn attackers and smart attackers according to whether would they change their attack modes with the changing of network structure; Then by simulations, link addition strategies are given separately according to different attackers, with which we can allocate the limited costs to add connectivity links and dependence links reasonably and achieve more robustness than only adding connectivity links or dependence links. The results show that compared to only adding connectivity links or dependence links, allocating the limited resources reasonably and adding both connectivity links and dependence links could bring more robustness to the interdependent networks.

Elution of lead from lead zirconate titanate ceramics to acid rain

NASA Astrophysics Data System (ADS)

Tsurumi, Takaaki; Takezawa, Shuhei; Hoshina, Takuya; Takeda, Hiroaki

2017-10-01

The amount of lead that eluted from lead zirconate titanate (PZT) ceramics to artificial acid rain was evaluated. Four kinds of PZT ceramics, namely, pure PZT at MPB composition, CuO-added PZT, PZT with 10 mol % substitution of Ba for Pb, and CuO-added PZT with 10 mol % substitution of Ba for Pb, were used as samples of the elution test. These PZT ceramics of 8 mm2 and 1.1-1.2 mm thickness were suspended in 300 ml of H2SO4 solution of pH 4.0. The concentration of lead eluted from PZT was in the range from 0.2 to 0.8 ppm. It was found that both liquid phase formation by the addition of CuO and the substitution of Ba for Pb were effective to reduce the amount of lead that eluted. By fitting the leaching out curve with a classical equation, a master curve assuming no sampling effect was obtained. The lead concentration evaluated from the amount of lead that eluted from a commercial PZT plate to H2SO4 solution of pH 5.3 was almost the same as the limit in city water. It is concluded that PZT is not harmful to health and the environment and the amount of lead that eluted from PZT can be controlled by modifying PZT composition.

Early Childhood Lead Exposure and Academic Achievement: Evidence From Detroit Public Schools, 2008–2010

PubMed Central

Baker, Harolyn W.; Tufts, Margaret; Raymond, Randall E.; Salihu, Hamisu; Elliott, Michael R.

2013-01-01

Objectives. We assessed the long-term effect of early childhood lead exposure on academic achievement in mathematics, science, and reading among elementary and junior high school children. Methods. We linked early childhood blood lead testing surveillance data from the Detroit Department of Health and Wellness Promotion to educational testing data from the Detroit, Michigan, public schools. We used the linked data to investigate the effect of early childhood lead exposure on academic achievement among school-aged children, both marginally and adjusted for grade level, gender, race, language, maternal education, and socioeconomic status. Results. High blood lead levels before age 6 years were strongly associated with poor academic achievement in grades 3, 5, and 8. The odds of scoring less than proficient for those whose blood lead levels were greater than 10 micrograms per deciliter were more than twice the odds for those whose blood lead levels were less than 1 micrograms per deciliter after adjustment for potential confounders. Conclusions. Early childhood lead exposure was negatively associated with academic achievement in elementary and junior high school, after adjusting for key potential confounders. The control of lead poisoning should focus on primary prevention of lead exposure in children and development of special education programs for students with lead poisoning. PMID:23327265

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.

Deployment of a multi-link flexible structure

NASA Astrophysics Data System (ADS)

Na, Kyung-Su; Kim, Ji-Hwan

2006-06-01

Deployment of a multi-link beam structure undergoing locking is analyzed in the Timoshenko beam theory. In the modeling of the system, dynamic forces are assumed to be torques and restoring forces due to the torsion spring at each joint. Hamilton's principle is used to determine the equations of motion and the finite element method is adopted to analyze the system. Newmark time integration and Newton-Raphson iteration methods are used to solve for the non-linear equations of motion at each time step. The locking at the joints of the multi-link flexible structure is analyzed by the momentum balance method. Numerical results are compared with the previous experimental data. The angles and angular velocities of each joint, tip displacement, and velocity of each link are investigated to study the motions of the links at each time step. To analyze the effect of thickness on the motion of the link, the angle and the tip displacement of each link are compared according to the various slenderness ratios. Additionally, in order to investigate the effect of shear, the tip displacements of a Timoshenko beam are compared with those of an Euler-Bernoulli beam.

Lead intoxication under environmental hypoxia impairs oral health.

PubMed

Terrizzi, Antonela R; Fernandez-Solari, Javier; Lee, Ching M; Martínez, María Pilar; Conti, María Ines

2014-01-01

We have reported that chronic lead intoxication under hypoxic environment induces alveolar bone loss that can lead to periodontal damage with the subsequent loss of teeth. The aim of the present study was to assess the modification of oral inflammatory parameters involved in the pathogenesis of periodontitis in the same experimental model. In gingival tissue, hypoxia increased inducible nitric oxid synthase (iNOS) activity (p < .01) and meanwhile lead decreased prostaglandin E2 (PGE2) content (p < .05). In submandibular gland (SMG), iNOS activity was enhanced by lead and PGE2 content was increased by both lead and hypoxia (p < .01) and even more by combined treatments (p < .001). In the SMG, hypoxia stimulated angiogenesis (p < .01) with blood extravasation. Adrenal glands were 22% bigger in those animals exposed to lead under hypoxic conditions. Results suggest a wide participation of inflammatory markers that mediate alveolar bone loss induced by these environmental conditions. The lack of information regarding oral health in lead-contaminated populations that coexist with hypoxia induced us to evaluate the alteration of inflammatory parameters in rat oral tissues to elucidate the link between periodontal damage and these environmental conditions.

Diesel fuel detergent additive performance and assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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 ofmore » 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.« less

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.

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 ...

76 FR 12944 - Children's Products Containing Lead; Technological Feasibility of 100 ppm for Lead Content...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-09

...Section 101(a) of the Consumer Product Safety Improvement Act (``CPSIA'') provides that, as of August 14, 2011, children's products may not contain more than 100 parts per million (``ppm'') of lead unless the U.S. Consumer Product Safety Commission (``CPSC,'' ``Commission,'' or ``we'') determines that such a limit is not technologically feasible. The Commission may make such a determination only after notice and a hearing and after analyzing the public health protections associated with substantially reducing lead in children's products. On February 16, 2011, the Commission conducted a public hearing to receive views from all interested parties about the technological feasibility of meeting the 100 ppm lead content limit for children's products and associated public health considerations. Individual Commissioners requested at the hearing that certain participants respond to additional questions in writing, as well as submit relevant studies and additional data referenced in oral presentations. Accordingly, through this notice, the Commission is reopening the hearing record until March 24, 2011.

On the Difference Between Additive and Subtractive QM/MM Calculations

PubMed Central

Cao, Lili; Ryde, Ulf

2018-01-01

The combined quantum mechanical (QM) and molecular mechanical (MM) approach (QM/MM) is a popular method to study reactions in biochemical macromolecules. Even if the general procedure of using QM for a small, but interesting part of the system and MM for the rest is common to all approaches, the details of the implementations vary extensively, especially the treatment of the interface between the two systems. For example, QM/MM can use either additive or subtractive schemes, of which the former is often said to be preferable, although the two schemes are often mixed up with mechanical and electrostatic embedding. In this article, we clarify the similarities and differences of the two approaches. We show that inherently, the two approaches should be identical and in practice require the same sets of parameters. However, the subtractive scheme provides an opportunity to correct errors introduced by the truncation of the QM system, i.e., the link atoms, but such corrections require additional MM parameters for the QM system. We describe and test three types of link-atom correction, viz. for van der Waals, electrostatic, and bonded interactions. The calculations show that electrostatic and bonded link-atom corrections often give rise to problems in the geometries and energies. The van der Waals link-atom corrections are quite small and give results similar to a pure additive QM/MM scheme. Therefore, both approaches can be recommended. PMID:29666794

On the difference between additive and subtractive QM/MM calculations

NASA Astrophysics Data System (ADS)

Cao, Lili; Ryde, Ulf

2018-04-01

The combined quantum mechanical (QM) and molecular mechanical (MM) approach (QM/MM) is a popular method to study reactions in biochemical macromolecules. Even if the general procedure of using QM for a small, but interesting part of the system and MM for the rest is common to all approaches, the details of the implementations vary extensively, especially the treatment of the interface between the two systems. For example, QM/MM can use either additive or subtractive schemes, of which the former is often said to be preferable, although the two schemes are often mixed up with mechanical and electrostatic embedding. In this article, we clarify the similarities and differences of the two approaches. We show that inherently, the two approaches should be identical and in practice require the same sets of parameters. However, the subtractive scheme provides an opportunity to correct errors introduced by the truncation of the QM system, i.e. the link atoms, but such corrections require additional MM parameters for the QM system. We describe and test three types of link-atom correction, viz. for van der Waals, electrostatic and bonded interactions. The calculations show that electrostatic and bonded link-atom corrections often give rise to problems in the geometries and energies. The van der Waals link-atom corrections are quite small and give results similar to a pure additive QM/MM scheme. Therefore, both approaches can be recommended.

FARVATX: Family-Based Rare Variant Association Test for X-Linked Genes.

PubMed

Choi, Sungkyoung; Lee, Sungyoung; Qiao, Dandi; Hardin, Megan; Cho, Michael H; Silverman, Edwin K; Park, Taesung; Won, Sungho

2016-09-01

Although the X chromosome has many genes that are functionally related to human diseases, the complicated biological properties of the X chromosome have prevented efficient genetic association analyses, and only a few significantly associated X-linked variants have been reported for complex traits. For instance, dosage compensation of X-linked genes is often achieved via the inactivation of one allele in each X-linked variant in females; however, some X-linked variants can escape this X chromosome inactivation. Efficient genetic analyses cannot be conducted without prior knowledge about the gene expression process of X-linked variants, and misspecified information can lead to power loss. In this report, we propose new statistical methods for rare X-linked variant genetic association analysis of dichotomous phenotypes with family-based samples. The proposed methods are computationally efficient and can complete X-linked analyses within a few hours. Simulation studies demonstrate the statistical efficiency of the proposed methods, which were then applied to rare-variant association analysis of the X chromosome in chronic obstructive pulmonary disease. Some promising significant X-linked genes were identified, illustrating the practical importance of the proposed methods. © 2016 WILEY PERIODICALS, INC.

FARVATX: FAmily-based Rare Variant Association Test for X-linked genes

PubMed Central

Choi, Sungkyoung; Lee, Sungyoung; Qiao, Dandi; Hardin, Megan; Cho, Michael H.; Silverman, Edwin K; Park, Taesung; Won, Sungho

2016-01-01

Although the X chromosome has many genes that are functionally related to human diseases, the complicated biological properties of the X chromosome have prevented efficient genetic association analyses, and only a few significantly associated X-linked variants have been reported for complex traits. For instance, dosage compensation of X-linked genes is often achieved via the inactivation of one allele in each X-linked variant in females; however, some X-linked variants can escape this X chromosome inactivation. Efficient genetic analyses cannot be conducted without prior knowledge about the gene expression process of X-linked variants, and misspecified information can lead to power loss. In this report, we propose new statistical methods for rare X-linked variant genetic association analysis of dichotomous phenotypes with family-based samples. The proposed methods are computationally efficient and can complete X-linked analyses within a few hours. Simulation studies demonstrate the statistical efficiency of the proposed methods, which were then applied to rare-variant association analysis of the X chromosome in chronic obstructive pulmonary disease (COPD). Some promising significant X-linked genes were identified, illustrating the practical importance of the proposed methods. PMID:27325607

Initiatives to Improve Quality of Additively Manufactured Parts

NASA Technical Reports Server (NTRS)

Waller, Jess; Nichols, Charles

2017-01-01

NASA is providing leadership in an international effort linking government and industry resources to speed adoption of additive manufactured (AM) parts. Participants include government agencies (NASA, USAF, NIST, FAA), industry (commercial aerospace, NDE manufacturers, AM equipment manufacturers), standards organizations and academia. NASA is also partnering with its international space exploration organizations such as ESA and JAXA. NDT is identified as a universal need for all aspects of additive manufacturing.

Is there a link between hospital profit and quality?

PubMed

Cleverley, W O; Harvey, R K

1992-09-01

In industrial firms, high perceived quality in products or services leads to high return on investment. The link between high quality and high profit is more difficult to document for healthcare products and services. An even more important question for healthcare managers is whether there is a link between poor-quality services and low profitability. A study of a small sample of HCFA high-mortality hospitals shows that poor quality hospitals are less profitable. Although the demand for the products and services of poor-quality hospitals is relatively strong, such hospitals are underinvested in assets and understaffed, the study shows.

Mocaf cross-linking with gluten to improve the quality of mocaf dough

NASA Astrophysics Data System (ADS)

Raharja, Sapta; Udin, Faqih; Suparno, Ono; Febrianti, Faricha Helfi; Nuraisyah, Ani

2017-03-01

Crosslink between mocaf and gluten is conducted to increase the using of mocaf which has very big potential in Indonesia. The effort of cross-linking between mocaf and gluten is to get mocaf flour with better dough quality. This study aims to produce a cross-linked mocaf-gluten flour and to evaluate the influence of heating temperature (X1) and the addition of gluten concentration (X2) using completely randomized design factorial (RAFL). The cross-linking is carried out in alkaline solution with 10%, 20%, and 30% gluten addition and heating temperature at 50, 55, and 60 °C. The result showed that mocaf - gluten flour with the treatment of 30% gluten addition at 55 °C had the largest amount of protein and baking expansion (i.e 19.77% and 2.78 mL/g). Swelling power of the flour was increasing along with the increasing of water absorbing capacity of the mocaf - gluten flour. Birefringence properties of mocaf - gluten flour tended to be reduced as the increasing heating temperature. FTIR analysis of mocaf - gluten flour showed that there was peak strengthening of the infrared spectrum of the C - N bond at 1167-1159 cm-1 which was presumably resulted from the gluten addition and the cross-linking properties.

Additive genetic variation and evolvability of a multivariate trait can be increased by epistatic gene action.

PubMed

Griswold, Cortland K

2015-12-21

Epistatic gene action occurs when mutations or alleles interact to produce a phenotype. Theoretically and empirically it is of interest to know whether gene interactions can facilitate the evolution of diversity. In this paper, we explore how epistatic gene action affects the additive genetic component or heritable component of multivariate trait variation, as well as how epistatic gene action affects the evolvability of multivariate traits. The analysis involves a sexually reproducing and recombining population. Our results indicate that under stabilizing selection conditions a population with a mixed additive and epistatic genetic architecture can have greater multivariate additive genetic variation and evolvability than a population with a purely additive genetic architecture. That greater multivariate additive genetic variation can occur with epistasis is in contrast to previous theory that indicated univariate additive genetic variation is decreased with epistasis under stabilizing selection conditions. In a multivariate setting, epistasis leads to less relative covariance among individuals in their genotypic, as well as their breeding values, which facilitates the maintenance of additive genetic variation and increases a population׳s evolvability. Our analysis involves linking the combinatorial nature of epistatic genetic effects to the ancestral graph structure of a population to provide insight into the consequences of epistasis on multivariate trait variation and evolution. Copyright © 2015 Elsevier Ltd. All rights reserved.

N(4)C-ethyl-N(4)C cross-linked DNA: synthesis and characterization of duplexes with interstrand cross-links of different orientations.

PubMed

Noronha, Anne M; Noll, David M; Wilds, Christopher J; Miller, Paul S

2002-01-22

, in which the cross-linked base pairs can still maintain hydrogen bond contacts, molecular models suggest that formation of the -GC- staggered cross-link disrupts hydrogen bonding and may also perturb adjacent base pairs leading to an overall reduction in helix stability. Duplexes with specifically positioned and oriented cross-links can be used as substrates to study DNA repair mechanisms.

[Noroviruses: leading cause of gastroenteritis].

PubMed

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

2010-04-01

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

A link prediction approach to cancer drug sensitivity prediction.

PubMed

Turki, Turki; Wei, Zhi

2017-10-03

Predicting the response to a drug for cancer disease patients based on genomic information is an important problem in modern clinical oncology. This problem occurs in part because many available drug sensitivity prediction algorithms do not consider better quality cancer cell lines and the adoption of new feature representations; both lead to the accurate prediction of drug responses. By predicting accurate drug responses to cancer, oncologists gain a more complete understanding of the effective treatments for each patient, which is a core goal in precision medicine. In this paper, we model cancer drug sensitivity as a link prediction, which is shown to be an effective technique. We evaluate our proposed link prediction algorithms and compare them with an existing drug sensitivity prediction approach based on clinical trial data. The experimental results based on the clinical trial data show the stability of our link prediction algorithms, which yield the highest area under the ROC curve (AUC) and are statistically significant. We propose a link prediction approach to obtain new feature representation. Compared with an existing approach, the results show that incorporating the new feature representation to the link prediction algorithms has significantly improved the performance.

Joint genetic analysis of hippocampal size in mouse and human identifies a novel gene linked to neurodegenerative disease.

PubMed

Ashbrook, David G; Williams, Robert W; Lu, Lu; Stein, Jason L; Hibar, Derrek P; Nichols, Thomas E; Medland, Sarah E; Thompson, Paul M; Hager, Reinmar

2014-10-03

Variation in hippocampal volume has been linked to significant differences in memory, behavior, and cognition among individuals. To identify genetic variants underlying such differences and associated disease phenotypes, multinational consortia such as ENIGMA have used large magnetic resonance imaging (MRI) data sets in human GWAS studies. In addition, mapping studies in mouse model systems have identified genetic variants for brain structure variation with great power. A key challenge is to understand how genetically based differences in brain structure lead to the propensity to develop specific neurological disorders. We combine the largest human GWAS of brain structure with the largest mammalian model system, the BXD recombinant inbred mouse population, to identify novel genetic targets influencing brain structure variation that are linked to increased risk for neurological disorders. We first use a novel cross-species, comparative analysis using mouse and human genetic data to identify a candidate gene, MGST3, associated with adult hippocampus size in both systems. We then establish the coregulation and function of this gene in a comprehensive systems-analysis. We find that MGST3 is associated with hippocampus size and is linked to a group of neurodegenerative disorders, such as Alzheimer's.

Modeling and control of a hydraulically actuated flexible-prismatic link robot

DOE Office of Scientific and Technical Information (OSTI.GOV)

Love, L.; Kress, R.; Jansen, J.

1996-12-01

Most of the research related to flexible link manipulators to date has focused on single link, fixed length, single plane of vibration test beds. In addition, actuation has been predominantly based upon electromagnetic motors. Ironically, these elements are rarely found in the existing industrial long reach systems. This manuscript describes a new hydraulically actuated, long reach manipulator with a flexible prismatic link at Oak Ridge National Laboratory (ORNL). Focus is directed towards both modeling and control of hydraulic actuators as well as flexible links that have variable natural frequencies.

Distribution and integrated assessment of lead in an abandoned lead-acid battery site in Southwest China before redevelopment.

PubMed

Wang, Mei; Zhang, Chao; Zhang, Zhuo; Li, Fasheng; Guo, Guanlin

2016-06-01

Lead-acid battery sites have contributed enormous amounts of lead to the environment, significantly affecting its global biogeochemical cycle and leaving the potential risks to human health. An abandoned lead-acid battery site prepared for redevelopment was selected in order to study the distribution of lead in soils, plants, rhizosphere soils and soil solutions. In total, 197 samples from 77 boreholes were collected and analyzed. Single extractions by acetic acid (HOAc) were conducted to assess the bioavailability and speciation of lead in soils for comparison with the parts of the plants that are aboveground. Health risks for future residential development were evaluated by the integrated exposure uptake biokinetic (IEUBK) model. The results indicated that lead concentrations in 83% of the soil samples exceeded the Chinese Environmental Quality Standard for soil (350 mg/kg for Pb) and mainly occurred at depths between 0 and 1.5 m while accumulating at the surface of demolished construction waste and miscellaneous fill. Lead concentrations in soil solutions and HOAc extraction leachates were linked closely to the contents of aboveground Broussonetia papyrifera and Artemisia annua, two main types of local plants that were found at the site. The probability density of lead in blood (PbB) in excess of 10 µg/dL could overtake the 99% mark in the residential scenario. The findings provided a relatively integrated method to illustrate the onsite investigations and assessment for similar sites before remediation and future development from more comprehensive aspects. Copyright © 2016 Elsevier Inc. All rights reserved.

Biodiversity and human well-being: an essential link for sustainable development

PubMed Central

Chazdon, Robin; Duffy, J. Emmett; Prager, Case; Worm, Boris

2016-01-01

As society strives to transition towards more sustainable development pathways, it is important to properly conceptualize the link between biodiversity (i.e. genes, traits, species and other dimensions) and human well-being (HWB; i.e. health, wealth, security and other dimensions). Here, we explore how published conceptual frameworks consider the extent to which the biodiversity–HWB links are being integrated into public discourse and scientific research and the implications of our findings for sustainable development. We find that our understanding has gradually evolved from seeing the value of biodiversity as an external commodity that may influence HWB to biodiversity as fundamental to HWB. Analysis of the literature trends indicates increasing engagement with the terms biodiversity, HWB and sustainable development in the public, science and policy spheres, but largely as independent rather than linked terms. We suggest that a consensus framework for sustainable development should include biodiversity explicitly as a suite of internal variables that both influence and are influenced by HWB. Doing so will enhance clarity and help shape coherent research and policy priorities. We further suggest that the absence of this link in development can inadvertently lead to a ratcheting down of biodiversity by otherwise well-meaning policies. Such biotic impoverishment could lock HWB at minimum levels or lead to its decline and halt or reverse progress in achieving sustainable development. PMID:27928039

Biodiversity and human well-being: an essential link for sustainable development.

PubMed

Naeem, Shahid; Chazdon, Robin; Duffy, J Emmett; Prager, Case; Worm, Boris

2016-12-14

As society strives to transition towards more sustainable development pathways, it is important to properly conceptualize the link between biodiversity (i.e. genes, traits, species and other dimensions) and human well-being (HWB; i.e. health, wealth, security and other dimensions). Here, we explore how published conceptual frameworks consider the extent to which the biodiversity-HWB links are being integrated into public discourse and scientific research and the implications of our findings for sustainable development. We find that our understanding has gradually evolved from seeing the value of biodiversity as an external commodity that may influence HWB to biodiversity as fundamental to HWB. Analysis of the literature trends indicates increasing engagement with the terms biodiversity, HWB and sustainable development in the public, science and policy spheres, but largely as independent rather than linked terms. We suggest that a consensus framework for sustainable development should include biodiversity explicitly as a suite of internal variables that both influence and are influenced by HWB. Doing so will enhance clarity and help shape coherent research and policy priorities. We further suggest that the absence of this link in development can inadvertently lead to a ratcheting down of biodiversity by otherwise well-meaning policies. Such biotic impoverishment could lock HWB at minimum levels or lead to its decline and halt or reverse progress in achieving sustainable development. © 2016 The Authors.

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

2017-10-01

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.

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. Copyright © 2013 Elsevier Ltd. All rights reserved.

Lead-induced ER calcium release and inhibitory effects of methionine choline in cultured rat hippocampal neurons.

PubMed

Fan, Guangqin; Zhou, Fankun; Feng, Chang; Wu, Fengyun; Ye, Weiwei; Wang, Chunhong; Lin, Fen; Yan, Ji; Li, Yanshu; Chen, Ying; Bi, Yongyi

2013-02-01

Lead, a ubiquitous neurotoxicant, can result in learning and memory dysfunction. Long term potentiation in the hippocampus, a potential neural substrate for learning and memory, is thought to be linked to calcium-triggered intracellular events. In this study, laser scanning confocal microscopy was used to examine the effects of Pb(2+) on intracellular and endoplasmic reticulum free calcium concentration ([Ca(2+)](i) and [Ca(2+)](ER)) in cultured neonatal rat hippocampal neurons and their possible antagonism by methionine choline; understanding these effects would help explain the lead-induced cognitive and learning dysfunction and explore efficient safety and relief strategies. The results showed that Pb(2+) increased [Ca(2+)](i) and decreased [Ca(2+)](ER) linearly in a time- and concentration-dependant manner, and Pb(2+) addition after the applying of a ryanodine receptor (RyR) antagonist and an inositol-1,4,5-triphosphate receptor (IP(3)R) antagonist did not increase [Ca(2+)](i). The addition of 10, 20, or 40 mmol/L methionine choline simultaneously with addition of 10 μmol/L Pb(2+) decreased [Ca(2+)](i) in Ca(2+)-free culture medium by 39.0%, 66.0%, and 61.6%, respectively, in a concentration-dependant manner in a certain dose range. Our results suggest that Pb(2+) induces ER calcium release to increase the resting [Ca(2+)](i); and methionine choline inhibit this increase in [Ca(2+)](i). Copyright © 2012 Elsevier Ltd. All rights reserved.

The combination of direct and paired link graphs can boost repetitive genome assembly

PubMed Central

Shi, Wenyu; Ji, Peifeng

2017-01-01

Abstract Currently, most paired link based scaffolding algorithms intrinsically mask the sequences between two linked contigs and bypass their direct link information embedded in the original de Bruijn assembly graph. Such disadvantage substantially complicates the scaffolding process and leads to the inability of resolving repetitive contig assembly. Here we present a novel algorithm, inGAP-sf, for effectively generating high-quality and continuous scaffolds. inGAP-sf achieves this by using a new strategy based on the combination of direct link and paired link graphs, in which direct link is used to increase graph connectivity and to decrease graph complexity and paired link is employed to supervise the traversing process on the direct link graph. Such advantage greatly facilitates the assembly of short-repeat enriched regions. Moreover, a new comprehensive decision model is developed to eliminate the noise routes accompanying with the introduced direct link. Through extensive evaluations on both simulated and real datasets, we demonstrated that inGAP-sf outperforms most of the genome scaffolding algorithms by generating more accurate and continuous assembly, especially for short repetitive regions. PMID:27924003

Links demystified: Periodontitis and cancer

PubMed Central

Pendyala, Gowri; Joshi, Saurabh; Chaudhari, Shantanu; Gandhage, Dhananjay

2013-01-01

Cancer is marked by the uncontrolled growth of cells, tissue invasion and metastasis to various organs via the circulatory and lymphatic systems. Recent data have expanded the concept that inflammation is a critical component of tumor progression. Many cancers arise from sites of infection, chronic irritation, and inflammation. The tumor microenvironment, which is largely orchestrated by inflammatory cells, is an indispensable participant in the neoplastic process, fostering proliferation, survival, and migration. Periodontal disease, a chronic inflammatory condition is characterized by an oral bacterial infection leading to inflammation within the supporting tissues of the teeth, which often leads to the destruction of the periodontal tissues and alveolar bone that support the teeth. This oral inflammation often has systemic effects leading to an increased concentration of circulating inflammatory markers with the severity of disease being correlated directly with levels of serum inflammatory markers. Periodontal infection has been linked to organ and systemic diseases. There is documented evidence of significant associations between cancer of the lung, kidney, pancreas, hematological and oral cancers, and periodontal disease. This articles reviews and summarizes the possible biological mechanisms involved between periodontal infection and cancer. PMID:24379856

Links demystified: Periodontitis and cancer.

PubMed

Pendyala, Gowri; Joshi, Saurabh; Chaudhari, Shantanu; Gandhage, Dhananjay

2013-11-01

Cancer is marked by the uncontrolled growth of cells, tissue invasion and metastasis to various organs via the circulatory and lymphatic systems. Recent data have expanded the concept that inflammation is a critical component of tumor progression. Many cancers arise from sites of infection, chronic irritation, and inflammation. The tumor microenvironment, which is largely orchestrated by inflammatory cells, is an indispensable participant in the neoplastic process, fostering proliferation, survival, and migration. Periodontal disease, a chronic inflammatory condition is characterized by an oral bacterial infection leading to inflammation within the supporting tissues of the teeth, which often leads to the destruction of the periodontal tissues and alveolar bone that support the teeth. This oral inflammation often has systemic effects leading to an increased concentration of circulating inflammatory markers with the severity of disease being correlated directly with levels of serum inflammatory markers. Periodontal infection has been linked to organ and systemic diseases. There is documented evidence of significant associations between cancer of the lung, kidney, pancreas, hematological and oral cancers, and periodontal disease. This articles reviews and summarizes the possible biological mechanisms involved between periodontal infection and cancer.

Interpreting and managing blood lead levels < 10 microg/dL in children and reducing childhood exposures to lead: recommendations of CDC's Advisory Committee on Childhood Lead Poisoning Prevention.

PubMed

2007-11-02

Lead is a common environmental contaminant, and exposure to lead is a preventable risk that exists in all areas of the United States. Lead is associated with negative outcomes in children, including impaired cognitive, motor, behavioral, and physical abilities. In 1991, CDC defined the blood lead level (BLL) that should prompt public health actions as 10 microg/dL. Concurrently, CDC also recognized that a BLL of 10 microg/dL did not define a threshold for the harmful effects of lead. Research conducted since 1991 has strengthened the evidence that children's physical and mental development can be affected at BLLs < or =10 microg/dL. This report summarizes the findings of a review of clinical interpretation and management of BLLs < or =10 microg/dL conducted by CDC's Advisory Committee on Childhood Lead Poisoning Prevention. This report provides information to help clinicians understand BLLs < or =10 microg/dL, identifies gaps in knowledge concerning lead levels in this range, and outlines strategies to reduce childhood exposures to lead. In addition, this report summarizes scientific data relevant to counseling, blood lead screening, and lead exposure risk assessment. To aid in the interpretation of BLLs, clinicians should understand the laboratory error range for blood lead values and, if possible, select a laboratory that achieves routine performance within +/-2 microg/dL. Clinicians should obtain an environmental history on all children they examine, provide families with lead prevention counseling, and follow blood lead screening recommendations established for their areas. As local and patient circumstances permit, clinicians should consider early referral to developmental programs for children at high risk for exposure to lead and consider more frequent rescreening of children with BLLs approaching 10 microg/dL, depending on the potential for exposure to lead, child age, and season of testing. In addition, clinicians should direct parents to agencies and

Childhood lead poisoning and the new Centers for Disease Control and Prevention guidelines for lead exposure.

PubMed

Schnur, Julie; John, Rita Marie

2014-05-01

This article will give a brief history, review the latest guidelines, discuss risk factors and sources, and discuss screening, diagnosis, and management of lead poisoning in children. Additionally, the role of the nurse practitioner (NP) caring for children will be reviewed. Review of published literature on lead poisoning and the 2012 lead prevention guidelines of the Advisory Committee on Childhood Lead Poisoning Prevention (ACCLPP) of the Centers for Disease Control and Prevention (CDC). While lead poisoning levels have decreased over the past several decades, newer research has shown that even low levels of lead in the blood can have negative effects on children's intelligence and neurodevelopment. As a result, ACCLPP of the CDC issued new, stricter lead prevention guidelines in 2012. Lead exposure and lead poisoning are pediatric public health risks. Studies have shown that no level of lead is considered safe, and the emphasis has shifted to primary prevention of lead exposure. Despite the focus on primary prevention, the NP must remain vigilant in history taking, exploring risk factors, and screening children in order to assure the best possible outcome. ©2014 The Author(s) ©2014 American Association of Nurse Practitioners.

25 CFR 215.17 - Additional information required.

Code of Federal Regulations, 2010 CFR

2010-04-01

... interested in lead and zinc mining leases, or land under the jurisdiction of the Quapaw Indian Agency, and... 25 Indians 1 2010-04-01 2010-04-01 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...

DNA interstrand cross-link repair: understanding role of Fanconi anemia pathway and therapeutic implications.

PubMed

Shukla, Pallavi; Solanki, Avani; Ghosh, Kanjaksha; Vundinti, Babu Rao

2013-11-01

Interstrand cross-links (ICLs) are extremely toxic DNA lesions that prevent DNA double-helix separation due to the irreversible covalent linkage binding of some agents on DNA strands. Agents that induce these ICLs are thus widely used as chemotherapeutic drugs but may also lead to tumor growth. Fanconi anemia (FA) is a rare genetic disorder that leads to ICL sensitivity. This review provides update on current understanding of the role of FA proteins in repairing ICLs at various stages of cell cycle. We also discuss link between DNA cross-link genotoxicity caused by aldehydes in FA pathway. Besides this, we summarize various ICL agents that act as drugs to treat different types of tumors and highlight strategies for modulating ICL sensitivity for therapeutic interventions that may be helpful in controlling cancer and life-threatening disease, FA. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Multiscale mechanical effects of native collagen cross-linking in tendon.

PubMed

Eekhoff, Jeremy D; Fang, Fei; Lake, Spencer P

2018-06-06

The hierarchical structure of tendon allows for attenuation of mechanical strain down decreasing length scales. While reorganization of collagen fibers accounts for microscale strain attenuation, cross-linking between collagen molecules contributes to deformation mechanisms at the fibrillar and molecular scales. Divalent and trivalent enzymatic cross-links form during the development of collagen fibrils through the enzymatic activity of lysyl oxidase (LOX). By establishing connections between telopeptidyl and triple-helical domains of adjacent molecules within collagen fibrils, these cross-links stiffen the fibrils by resisting intermolecular sliding. Ultimately, greater enzymatic cross-linking leads to less compliant and stronger tendon as a result of stiffer fibrils. In contrast, nonenzymatic cross-links such as glucosepane and pentosidine are not produced during development but slowly accumulate through glycation of collagen. Therefore, these cross-links are only expected to be present in significant quantities in advanced age, where there has been sufficient time for glycation to occur, and in diabetes, where the presence of more free sugar in the extracellular matrix increases the rate of glycation. Unlike enzymatic cross-links, current evidence suggests that nonenzymatic cross-links are at least partially isolated to the surface of collagen fibers. As a result, glycation has been proposed to primarily impact tendon mechanics by altering molecular interactions at the fiber interface, thereby diminishing sliding between fibers. Thus, increased nonenzymatic cross-linking decreases microscale strain attenuation and the viscous response of tendon. In conclusion, enzymatic and nonenzymatic collagen cross-links have demonstrable and distinct effects on the mechanical properties of tendon across different length scales.

Direct mechanical stimulation of tip links in hair cells through DNA tethers

PubMed Central

Basu, Aakash; Lagier, Samuel; Vologodskaia, Maria; Fabella, Brian A; Hudspeth, AJ

2016-01-01

Mechanoelectrical transduction by hair cells commences with hair-bundle deflection, which is postulated to tense filamentous tip links connected to transduction channels. Because direct mechanical stimulation of tip links has not been experimentally possible, this hypothesis has not been tested. We have engineered DNA tethers that link superparamagnetic beads to tip links and exert mechanical forces on the links when exposed to a magnetic-field gradient. By pulling directly on tip links of the bullfrog's sacculus we have evoked transduction currents from hair cells, confirming the hypothesis that tension in the tip links opens transduction channels. This demonstration of direct mechanical access to tip links additionally lays a foundation for experiments probing the mechanics of individual channels. DOI: http://dx.doi.org/10.7554/eLife.16041.001 PMID:27331611

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

PubMed Central

Udovic, M.; McBride, M.B.

2015-01-01

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

Surface topography characterization of brass alloys: lead brass (CuZn39Pb3) and lead free brass (CuZn21Si3P)

NASA Astrophysics Data System (ADS)

Reddy, Vijeth V.; Vedantha Krishna, Amogh; Schultheiss, Fredrik; Rosén, B.-G.

2017-06-01

Manufactured surfaces usually consist of topographical features which include both those put forth by the manufacturing process, and micro-features caused by disturbances during this process. Surface characterization basically involves study of these features which influence the functionality of the surface. This article focuses on characterization of the surface topography of machined lead brass and lead free brass. The adverse effect of lead on human health and the environment has led the manufacturing sector to focus on sustainable manufacturing of lead free brass, as well as how to maintain control of the surface integrity when substituting the lead content in the brass with silicon. The investigation includes defined areal surface parameters measured on the turned samples of lead- and lead free brass using an optical coherence scanning interferometer, CSI. This paper deals with the study of surface topography of turned samples of lead- and lead free brass. It is important to study the topographical characteristics of the brass samples which are the intermediate link between the manufacturing process variables and the functional behaviour of the surface. To numerically evaluate the sample’s surface topography and to validate the measurements for a significant study, a general statistical methodology is implemented. The results indicate higher surface roughness in turned samples of lead brass compared to lead free brass.

A Bayesian model for estimating population means using a link-tracing sampling design.

PubMed

St Clair, Katherine; O'Connell, Daniel

2012-03-01

Link-tracing sampling designs can be used to study human populations that contain "hidden" groups who tend to be linked together by a common social trait. These links can be used to increase the sampling intensity of a hidden domain by tracing links from individuals selected in an initial wave of sampling to additional domain members. Chow and Thompson (2003, Survey Methodology 29, 197-205) derived a Bayesian model to estimate the size or proportion of individuals in the hidden population for certain link-tracing designs. We propose an addition to their model that will allow for the modeling of a quantitative response. We assess properties of our model using a constructed population and a real population of at-risk individuals, both of which contain two domains of hidden and nonhidden individuals. Our results show that our model can produce good point and interval estimates of the population mean and domain means when our population assumptions are satisfied. © 2011, The International Biometric Society.

Electro-Responsive Behaviour Multi-Wall Nanotubes/Gelatin Composites and Cross-Linked Gelatin Electrospun Mats

DTIC Science & Technology

2008-02-11

sample , could explain large swelling in blend samples which might enhance ions diffusion and lead to an increase of bending. 21 References [1...1 Final Report on Electro-responsive behaviour multi-wall nanotubes/gelatin composites and cross-linked gelatin electrospun mats...12-10-2007 4. TITLE AND SUBTITLE Electro-responsive behaviour multi-wall nanotubes/gelatin composites and cross-linked gelatin electrospun mats

BPS States, Torus Links and Wild Character Varieties

NASA Astrophysics Data System (ADS)

Diaconescu, Duiliu-Emanuel; Donagi, Ron; Pantev, Tony

2018-02-01

A string theoretic framework is constructed relating the cohomology of wild character varieties to refined stable pair theory and torus link invariants. Explicit conjectural formulas are derived for wild character varieties with a unique irregular point on the projective line. For this case, this leads to a conjectural colored generalization of existing results of Hausel, Mereb and Wong as well as Shende, Treumann and Zaslow.

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.

Provenance Usage in the OceanLink Project

NASA Astrophysics Data System (ADS)

Narock, T.; Arko, R. A.; Carbotte, S. M.; Chandler, C. L.; Cheatham, M.; Fils, D.; Finin, T.; Hitzler, P.; Janowicz, K.; Jones, M.; Krisnadhi, A.; Lehnert, K. A.; Mickle, A.; Raymond, L. M.; Schildhauer, M.; Shepherd, A.; Wiebe, P. H.

2014-12-01

A wide spectrum of maturing methods and tools, collectively characterized as the Semantic Web, is helping to vastly improve thedissemination of scientific research. The OceanLink project, an NSF EarthCube Building Block, is utilizing semantic technologies tointegrate geoscience data repositories, library holdings, conference abstracts, and funded research awards. Provenance is a vital componentin meeting both the scientific and engineering requirements of OceanLink. Provenance plays a key role in justification and understanding when presenting users with results aggregated from multiple sources. In the engineering sense, provenance enables the identification of new data and the ability to determine which data sources to query. Additionally, OceanLink will leverage human and machine computation for crowdsourcing, text mining, and co-reference resolution. The results of these computations, and their associated provenance, will be folded back into the constituent systems to continually enhance precision and utility. We will touch on the various roles provenance is playing in OceanLink as well as present our use of the PROV Ontology and associated Ontology Design Patterns.

Structural analysis of glycoproteins: building N-linked glycans with Coot.

PubMed

Emsley, Paul; Crispin, Max

2018-04-01

Coot is a graphics application that is used to build or manipulate macromolecular models; its particular forte is manipulation of the model at the residue level. The model-building tools of Coot have been combined and extended to assist or automate the building of N-linked glycans. The model is built by the addition of monosaccharides, placed by variation of internal coordinates. The subsequent model is refined by real-space refinement, which is stabilized with modified and additional restraints. It is hoped that these enhanced building tools will help to reduce building errors of N-linked glycans and improve our knowledge of the structures of glycoproteins.

Technical trends in industrial lead/acid batteries in Japan

NASA Astrophysics Data System (ADS)

Iwata, Masashi; Tagawa, Yahachiro

1994-02-01

Although there have been only a few major technological changes in stationary lead/acid batteries in the past, some rapid and remarkable developments have occurred recently. The latter have included the introduction of catalyst plugs and valve-regulated lead/acid batteries (VRBs). Catalyst plugs have been used to avoid water addition with stationary lead/acid batteries. By virtue of their advantages (i.e., the elements retain electrolyte and equalizing charging and water addition are unnecessary), VRBs are being developed up to a maximum capacity of 3000 Ah. These designs have now captured about 50% of the stationary lead/acid battery market. The VRB technology has excellent characteristics, such as plate construction that can accommodate grid growth, explosion-resistant plugs, good discharge characteristics, and minimal electrolyte stratification. In addition, by utilizing the benefits of VRBs, horizontal and multistoried systems can be assembled, though in early stages of development the construction was only for interchangeability with flooded-electrolyte type batteries.

Effectiveness of link prediction for face-to-face behavioral networks.

PubMed

Tsugawa, Sho; Ohsaki, Hiroyuki

2013-01-01

Research on link prediction for social networks has been actively pursued. In link prediction for a given social network obtained from time-windowed observation, new link formation in the network is predicted from the topology of the obtained network. In contrast, recent advances in sensing technology have made it possible to obtain face-to-face behavioral networks, which are social networks representing face-to-face interactions among people. However, the effectiveness of link prediction techniques for face-to-face behavioral networks has not yet been explored in depth. To clarify this point, here we investigate the accuracy of conventional link prediction techniques for networks obtained from the history of face-to-face interactions among participants at an academic conference. Our findings were (1) that conventional link prediction techniques predict new link formation with a precision of 0.30-0.45 and a recall of 0.10-0.20, (2) that prolonged observation of social networks often degrades the prediction accuracy, (3) that the proposed decaying weight method leads to higher prediction accuracy than can be achieved by observing all records of communication and simply using them unmodified, and (4) that the prediction accuracy for face-to-face behavioral networks is relatively high compared to that for non-social networks, but not as high as for other types of social networks.

Effectiveness of Link Prediction for Face-to-Face Behavioral Networks

PubMed Central

Tsugawa, Sho; Ohsaki, Hiroyuki

2013-01-01

Research on link prediction for social networks has been actively pursued. In link prediction for a given social network obtained from time-windowed observation, new link formation in the network is predicted from the topology of the obtained network. In contrast, recent advances in sensing technology have made it possible to obtain face-to-face behavioral networks, which are social networks representing face-to-face interactions among people. However, the effectiveness of link prediction techniques for face-to-face behavioral networks has not yet been explored in depth. To clarify this point, here we investigate the accuracy of conventional link prediction techniques for networks obtained from the history of face-to-face interactions among participants at an academic conference. Our findings were (1) that conventional link prediction techniques predict new link formation with a precision of 0.30–0.45 and a recall of 0.10–0.20, (2) that prolonged observation of social networks often degrades the prediction accuracy, (3) that the proposed decaying weight method leads to higher prediction accuracy than can be achieved by observing all records of communication and simply using them unmodified, and (4) that the prediction accuracy for face-to-face behavioral networks is relatively high compared to that for non-social networks, but not as high as for other types of social networks. PMID:24339956

Orbit determination of the Next-Generation Beidou satellites with Intersatellite link measurements and a priori orbit constraints

NASA Astrophysics Data System (ADS)

Ren, Xia; Yang, Yuanxi; Zhu, Jun; Xu, Tianhe

2017-11-01

Intersatellite Link (ISL) technology helps to realize the auto update of broadcast ephemeris and clock error parameters for Global Navigation Satellite System (GNSS). ISL constitutes an important approach with which to both improve the observation geometry and extend the tracking coverage of China's Beidou Navigation Satellite System (BDS). However, ISL-only orbit determination might lead to the constellation drift, rotation, and even lead to the divergence in orbit determination. Fortunately, predicted orbits with good precision can be used as a priori information with which to constrain the estimated satellite orbit parameters. Therefore, the precision of satellite autonomous orbit determination can be improved by consideration of a priori orbit information, and vice versa. However, the errors of rotation and translation in a priori orbit will remain in the ultimate result. This paper proposes a constrained precise orbit determination (POD) method for a sub-constellation of the new Beidou satellite constellation with only a few ISLs. The observation model of dual one-way measurements eliminating satellite clock errors is presented, and the orbit determination precision is analyzed with different data processing backgrounds. The conclusions are as follows. (1) With ISLs, the estimated parameters are strongly correlated, especially the positions and velocities of satellites. (2) The performance of determined BDS orbits will be improved by the constraints with more precise priori orbits. The POD precision is better than 45 m with a priori orbit constrain of 100 m precision (e.g., predicted orbits by telemetry tracking and control system), and is better than 6 m with precise priori orbit constraints of 10 m precision (e.g., predicted orbits by international GNSS monitoring & Assessment System (iGMAS)). (3) The POD precision is improved by additional ISLs. Constrained by a priori iGMAS orbits, the POD precision with two, three, and four ISLs is better than 6, 3, and 2

Humic Acids as Therapeutic Compounds in Lead Intoxication.

PubMed

Krempaská, Klára; Vaško, Ladislav; Vašková, Janka

2016-01-01

The toxicity of lead and its compounds is well known, causing anemia by inhibiting the synthesis of porphyrins. The neurotoxic effects, particularly in the young, alter the structure of cell membranes and DNA. Chronic exposure to lead has adverse effects on the body by disrupting the mechanisms of energy production and tissue damage, in particular in its links with thiol groups and competition for binding sites with zinc. This review is therefore a description of the mechanism of lead toxicity as well as of possible interventions for the detoxification of the body. Part of the clinical intervention is the provision of chelates that form insoluble complexes with lead and eliminate the load in tissues. Most of these chelating agents have a number of side effects. It is therefore not surprising that active compounds with distinctive antioxidant and chelating properties are being sought after. The possibility of administering lower amounts, and the corresponding decrease in side effects, would be important for clinical practice. Both prospective studies and our initial studies on humic acids have highlighted positive effects based on their antioxidant and chelating properties.

Evaluation of a childhood lead questionnaire in predicting elevated blood lead levels in a rural community.

PubMed

Muñiz, Marco A; Dundas, Robert; Mahoney, Martin C

2003-01-01

The accuracy of a lead screening questionnaire in predicting elevated blood lead levels was examined in a pediatric practice in a rural part of New York state. A retrospective chart review was used to collect data on children ages 9 to 24 months who presented for well-child visits. Children with both questionnaire and lead level results available in the chart were included in the study (n = 171). The mean blood lead level among all children was 1.6 microg/dl (median = 2.0 microg/dl, range 0 to 24 microg/dl). Four children (2.3%) had elevated lead levels (greater than 10 microg/dl), with levels for two of these children being greater than 20 microg/dl. Although our lead screening questionnaire was expanded from the standard 1991 CDC questionnaire by the inclusion of six additional items, it was not especially useful in predicting elevated blood lead levels above 10 microg/dl. However, the questionnaire exhibited some utility in predicting marked elevations in blood lead levels (over 20 microg/dl). Although results in other geographic areas might differ, the lead questionnaire may have value by enhancing parents' awareness of potential lead hazards in their children's environment and may prove to be more useful in areas of high risk to lead exposure.

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.

[A "historical" case of lead poisoning via drinking water: diagnostic and therapeutic issues].

PubMed

Testud, F; Girtanner-Brunel, L; Péaud, P Y; Serpollet, G; Duchen, C

2001-12-01

It is likely that lead poisoning via drinking water is often overlooked because of its supposed rarity and nonspecific early symptoms, which result in delayed management. One case of severe lead poisoning via drinking water is reported. The diagnosis was long missed and a particularly long chelating treatment was required. The clinical features included lead colic, a Burton's lead line, anemia, polyneuritis and arterial hypertension. Eighteen courses of calcium EDTA were required to obtain 'biological recovery'. The poisoning was linked to a very long water supply lead pipe and potomania secondary to alcohol withdrawal. This case report illustrates how difficult the early recognition of lead poisoning can be, and underlines the need to inquire about a toxic aetiology, particularly via the environment, of otherwise unexplained pathological conditions.

5 CFR 532.315 - Additional survey jobs.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Additional survey jobs. 532.315 Section... RATE SYSTEMS Determining Rates for Principal Types of Positions § 532.315 Additional survey jobs. (a) For appropriated fund surveys, when the lead agency adds to the industries to be surveyed, it shall...

5 CFR 532.315 - Additional survey jobs.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Additional survey jobs. 532.315 Section... RATE SYSTEMS Determining Rates for Principal Types of Positions § 532.315 Additional survey jobs. (a) For appropriated fund surveys, when the lead agency adds to the industries to be surveyed, it shall...

5 CFR 532.315 - Additional survey jobs.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Additional survey jobs. 532.315 Section... RATE SYSTEMS Determining Rates for Principal Types of Positions § 532.315 Additional survey jobs. (a) For appropriated fund surveys, when the lead agency adds to the industries to be surveyed, it shall...

5 CFR 532.315 - Additional survey jobs.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Additional survey jobs. 532.315 Section... RATE SYSTEMS Determining Rates for Principal Types of Positions § 532.315 Additional survey jobs. (a) For appropriated fund surveys, when the lead agency adds to the industries to be surveyed, it shall...

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.

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

Persistent Identifiers for Improved Accessibility for Linked Data Querying

NASA Astrophysics Data System (ADS)

Shepherd, A.; Chandler, C. L.; Arko, R. A.; Fils, D.; Jones, M. B.; Krisnadhi, A.; Mecum, B.

2016-12-01

The adoption of linked open data principles within the geosciences has increased the amount of accessible information available on the Web. However, this data is difficult to consume for those who are unfamiliar with Semantic Web technologies such as Web Ontology Language (OWL), Resource Description Framework (RDF) and SPARQL - the RDF query language. Consumers would need to understand the structure of the data and how to efficiently query it. Furthermore, understanding how to query doesn't solve problems of poor precision and recall in search results. For consumers unfamiliar with the data, full-text searches are most accessible, but not ideal as they arrest the advantages of data disambiguation and co-reference resolution efforts. Conversely, URI searches across linked data can deliver improved search results, but knowledge of these exact URIs may remain difficult to obtain. The increased adoption of Persistent Identifiers (PIDs) can lead to improved linked data querying by a wide variety of consumers. Because PIDs resolve to a single entity, they are an excellent data point for disambiguating content. At the same time, PIDs are more accessible and prominent than a single data provider's linked data URI. When present in linked open datasets, PIDs provide balance between the technical and social hurdles of linked data querying as evidenced by the NSF EarthCube GeoLink project. The GeoLink project, funded by NSF's EarthCube initiative, have brought together data repositories include content from field expeditions, laboratory analyses, journal publications, conference presentations, theses/reports, and funding awards that span scientific studies from marine geology to marine ecosystems and biogeochemistry to paleoclimatology.

N-linked glycan truncation causes enhanced clearance of plasma-derived von Willebrand factor.

PubMed

O'Sullivan, J M; Aguila, S; McRae, E; Ward, S E; Rawley, O; Fallon, P G; Brophy, T M; Preston, R J S; Brady, L; Sheils, O; Chion, A; O'Donnell, J S

2016-12-01

Essentials von Willebrands factor (VWF) glycosylation plays a key role in modulating in vivo clearance. VWF glycoforms were used to examine the role of specific glycan moieties in regulating clearance. Reduction in sialylation resulted in enhanced VWF clearance through asialoglycoprotein receptor. Progressive VWF N-linked glycan trimming resulted in increased macrophage-mediated clearance. Click to hear Dr Denis discuss clearance of von Willebrand factor in a free presentation from the ISTH Academy SUMMARY: Background Enhanced von Willebrand factor (VWF) clearance is important in the etiology of both type 1 and type 2 von Willebrand disease (VWD). In addition, previous studies have demonstrated that VWF glycans play a key role in regulating in vivo clearance. However, the molecular mechanisms underlying VWF clearance remain poorly understood. Objective To define the molecular mechanisms through which VWF N-linked glycan structures influence in vivo clearance. Methods By use of a series of exoglycosidases, different plasma-derived VWF (pd-VWF) glycoforms were generated. In vivo clearance of these glycoforms was then assessed in VWF -/- mice in the presence or absence of inhibitors of asialoglycoprotein receptor (ASGPR), or following clodronate-induced macrophage depletion. Results Reduced amounts of N-linked and O-linked sialylation resulted in enhanced pd-VWF clearance modulated via ASGPR. In addition to this role of terminal sialylation, we further observed that progressive N-linked glycan trimming also resulted in markedly enhanced VWF clearance. Furthermore, these additional N-linked glycan effects on clearance were ASGPR-independent, and instead involved enhanced macrophage clearance that was mediated, at least in part, through LDL receptor-related protein 1. Conclusion The carbohydrate determinants expressed on VWF regulate susceptibility to proteolysis by ADAMTS-13. In addition, our findings now further demonstrate that non-sialic acid carbohydrate

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.

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.

Evaluation of Lead Release in a Simulated Lead-Free Premise Plumbing System Using a Sequential Sampling Approach

PubMed Central

Ng, Ding-Quan; Lin, Yi-Pin

2016-01-01

In this pilot study, a modified sampling protocol was evaluated for the detection of lead contamination and locating the source of lead release in a simulated premise plumbing system with one-, three- and seven-day stagnation for a total period of 475 days. Copper pipes, stainless steel taps and brass fittings were used to assemble the “lead-free” system. Sequential sampling using 100 mL was used to detect lead contamination while that using 50 mL was used to locate the lead source. Elevated lead levels, far exceeding the World Health Organization (WHO) guideline value of 10 µg·L−1, persisted for as long as five months in the system. “Lead-free” brass fittings were identified as the source of lead contamination. Physical disturbances, such as renovation works, could cause short-term spikes in lead release. Orthophosphate was able to suppress total lead levels below 10 µg·L−1, but caused “blue water” problems. When orthophosphate addition was ceased, total lead levels began to spike within one week, implying that a continuous supply of orthophosphate was required to control total lead levels. Occasional total lead spikes were observed in one-day stagnation samples throughout the course of the experiments. PMID:26927154

Evaluation of Lead Release in a Simulated Lead-Free Premise Plumbing System Using a Sequential Sampling Approach.

PubMed

Ng, Ding-Quan; Lin, Yi-Pin

2016-02-27

In this pilot study, a modified sampling protocol was evaluated for the detection of lead contamination and locating the source of lead release in a simulated premise plumbing system with one-, three- and seven-day stagnation for a total period of 475 days. Copper pipes, stainless steel taps and brass fittings were used to assemble the "lead-free" system. Sequential sampling using 100 mL was used to detect lead contamination while that using 50 mL was used to locate the lead source. Elevated lead levels, far exceeding the World Health Organization (WHO) guideline value of 10 µg · L(-1), persisted for as long as five months in the system. "Lead-free" brass fittings were identified as the source of lead contamination. Physical disturbances, such as renovation works, could cause short-term spikes in lead release. Orthophosphate was able to suppress total lead levels below 10 µg · L(-1), but caused "blue water" problems. When orthophosphate addition was ceased, total lead levels began to spike within one week, implying that a continuous supply of orthophosphate was required to control total lead levels. Occasional total lead spikes were observed in one-day stagnation samples throughout the course of the experiments.

The ChEMBL database as linked open data

PubMed Central

2013-01-01

Background Making data available as Linked Data using Resource Description Framework (RDF) promotes integration with other web resources. RDF documents can natively link to related data, and others can link back using Uniform Resource Identifiers (URIs). RDF makes the data machine-readable and uses extensible vocabularies for additional information, making it easier to scale up inference and data analysis. Results This paper describes recent developments in an ongoing project converting data from the ChEMBL database into RDF triples. Relative to earlier versions, this updated version of ChEMBL-RDF uses recently introduced ontologies, including CHEMINF and CiTO; exposes more information from the database; and is now available as dereferencable, linked data. To demonstrate these new features, we present novel use cases showing further integration with other web resources, including Bio2RDF, Chem2Bio2RDF, and ChemSpider, and showing the use of standard ontologies for querying. Conclusions We have illustrated the advantages of using open standards and ontologies to link the ChEMBL database to other databases. Using those links and the knowledge encoded in standards and ontologies, the ChEMBL-RDF resource creates a foundation for integrated semantic web cheminformatics applications, such as the presented decision support. PMID:23657106

Durability and mechanical properties of silane cross-linked wood thermoplastic composites

Treesearch

Magnus Bengtsson; Nicole M. Stark; Kristiina Oksman

2007-01-01

In this study, silane cross-linked wood–polyethylene composite profiles were manufactured by reactive extrusion. These composites were evaluated regarding their durability and mechanical properties in comparison with two non-cross-linked wood– polyethylene composites. An addition of only 2% w/w of silane solution during manufacturing was enough to achieve almost 60%...

A high speed telemetry data link for an autonomous roving vehicle

NASA Technical Reports Server (NTRS)

Cipolle, D. J.

1980-01-01

A data link system used on a prototype autonomous roving vehicle is described. This system provides a means of acquiring, formatting, and transmitting information on board the vehicle to a controlling computer. Included is a statement of requirements and the design philosophy. Additionally, interfacing with the rover systems is discussed, along with the overall performance of the telemetry link.

Design and implementation of an automated compound management system in support of lead optimization.

PubMed

Quintero, Catherine; Kariv, Ilona

2009-06-01

To meet the needs of the increasingly rapid and parallelized lead optimization process, a fully integrated local compound storage and liquid handling system was designed and implemented to automate the generation of assay-ready plates directly from newly submitted and cherry-picked compounds. A key feature of the system is the ability to create project- or assay-specific compound-handling methods, which provide flexibility for any combination of plate types, layouts, and plate bar-codes. Project-specific workflows can be created by linking methods for processing new and cherry-picked compounds and control additions to produce a complete compound set for both biological testing and local storage in one uninterrupted workflow. A flexible cherry-pick approach allows for multiple, user-defined strategies to select the most appropriate replicate of a compound for retesting. Examples of custom selection parameters include available volume, compound batch, and number of freeze/thaw cycles. This adaptable and integrated combination of software and hardware provides a basis for reducing cycle time, fully automating compound processing, and ultimately increasing the rate at which accurate, biologically relevant results can be produced for compounds of interest in the lead optimization process.

Cascaded optical fiber link using the internet network for remote clocks comparison.

PubMed

Chiodo, Nicola; Quintin, Nicolas; Stefani, Fabio; Wiotte, Fabrice; Camisard, Emilie; Chardonnet, Christian; Santarelli, Giorgio; Amy-Klein, Anne; Pottie, Paul-Eric; Lopez, Olivier

2015-12-28

We report a cascaded optical link of 1100 km for ultra-stable frequency distribution over an Internet fiber network. The link is composed of four spans for which the propagation noise is actively compensated. The robustness and the performance of the link are ensured by five fully automated optoelectronic stations, two of them at the link ends, and three deployed on the field and connecting the spans. This device coherently regenerates the optical signal with the heterodyne optical phase locking of a low-noise laser diode. Optical detection of the beat-note signals for the laser lock and the link noise compensation are obtained with stable and low-noise fibered optical interferometer. We show 3.5 days of continuous operation of the noise-compensated 4-span cascaded link leading to fractional frequency instability of 4x10(-16) at 1-s measurement time and 1x10(-19) at 2000 s. This cascaded link was extended to 1480-km with the same performance. This work is a significant step towards a sustainable wide area ultra-stable optical frequency distribution and comparison network at a very high level of performance.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ke, Weijun; Xiao, Chuanxiao; Wang, Changlei

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%.

When Practice Doesn't Lead to Retrieval: An Analysis of Children's Errors with Simple Addition

ERIC Educational Resources Information Center

de Villiers, Celéste; Hopkins, Sarah

2013-01-01

Counting strategies initially used by young children to perform simple addition are often replaced by more efficient counting strategies, decomposition strategies and rule-based strategies until most answers are encoded in memory and can be directly retrieved. Practice is thought to be the key to developing fluent retrieval of addition facts. This…

Cumulant generating function formula of heat transfer in ballistic systems with lead-lead coupling

NASA Astrophysics Data System (ADS)

Li, Huanan; Agarwalla, Bijay Kumar; Wang, Jian-Sheng

2012-10-01

Based on a two-time observation protocol, we consider heat transfer in a given time interval tM in a lead-junction-lead system taking coupling between the leads into account. In view of the two-time observation, consistency conditions are carefully verified in our specific family of quantum histories. Furthermore, its implication is briefly explored. Then using the nonequilibrium Green's function method, we obtain an exact formula for the cumulant generating function for heat transfer between the two leads, valid in both transient and steady-state regimes. Also, a compact formula for the cumulant generating function in the long-time limit is derived, for which the Gallavotti-Cohen fluctuation symmetry is explicitly verified. In addition, we briefly discuss Di Ventra's repartitioning trick regarding whether the repartitioning procedure of the total Hamiltonian affects the nonequilibrium steady-state current fluctuation. All kinds of properties of nonequilibrium current fluctuations, such as the fluctuation theorem in different time regimes, could be readily given according to these exact formulas.

Xilmass: A New Approach toward the Identification of Cross-Linked Peptides.

PubMed

Yılmaz, Şule; Drepper, Friedel; Hulstaert, Niels; Černič, Maša; Gevaert, Kris; Economou, Anastassios; Warscheid, Bettina; Martens, Lennart; Vandermarliere, Elien

2016-10-18

Chemical cross-linking coupled with mass spectrometry plays an important role in unravelling protein interactions, especially weak and transient ones. Moreover, cross-linking complements several structural determination approaches such as cryo-EM. Although several computational approaches are available for the annotation of spectra obtained from cross-linked peptides, there remains room for improvement. Here, we present Xilmass, a novel algorithm to identify cross-linked peptides that introduces two new concepts: (i) the cross-linked peptides are represented in the search database such that the cross-linking sites are explicitly encoded, and (ii) the scoring function derived from the Andromeda algorithm was adapted to score against a theoretical tandem mass spectrometry (MS/MS) spectrum that contains the peaks from all possible fragment ions of a cross-linked peptide pair. The performance of Xilmass was evaluated against the recently published Kojak and the popular pLink algorithms on a calmodulin-plectin complex data set, as well as three additional, published data sets. The results show that Xilmass typically had the highest number of identified distinct cross-linked sites and also the highest number of predicted cross-linked sites.

Evil genius? How dishonesty can lead to greater creativity.

PubMed

Gino, Francesca; Wiltermuth, Scott S

2014-04-01

We propose that dishonest and creative behavior have something in common: They both involve breaking rules. Because of this shared feature, creativity may lead to dishonesty (as shown in prior work), and dishonesty may lead to creativity (the hypothesis we tested in this research). In five experiments, participants had the opportunity to behave dishonestly by overreporting their performance on various tasks. They then completed one or more tasks designed to measure creativity. Those who cheated were subsequently more creative than noncheaters, even when we accounted for individual differences in their creative ability (Experiment 1). Using random assignment, we confirmed that acting dishonestly leads to greater creativity in subsequent tasks (Experiments 2 and 3). The link between dishonesty and creativity is explained by a heightened feeling of being unconstrained by rules, as indicated by both mediation (Experiment 4) and moderation (Experiment 5).

Epigenetics, obesity and early-life cadmium or lead exposure

PubMed Central

Park, Sarah S; Skaar, David A; Jirtle, Randy L; Hoyo, Cathrine

2017-01-01

Obesity is a complex and multifactorial disease, which likely comprises multiple subtypes. Emerging data have linked chemical exposures to obesity. As organismal response to environmental exposures includes altered gene expression, identifying the regulatory epigenetic changes involved would be key to understanding the path from exposure to phenotype and provide new tools for exposure detection and risk assessment. In this report, we summarize published data linking early-life exposure to the heavy metals, cadmium and lead, to obesity. We also discuss potential mechanisms, as well as the need for complete coverage in epigenetic screening to fully identify alterations. The keys to understanding how metal exposure contributes to obesity are improved assessment of exposure and comprehensive establishment of epigenetic profiles that may serve as markers for exposures. PMID:27981852

Epigenetics, obesity and early-life cadmium or lead exposure.

PubMed

Park, Sarah S; Skaar, David A; Jirtle, Randy L; Hoyo, Cathrine

2017-01-01

Obesity is a complex and multifactorial disease, which likely comprises multiple subtypes. Emerging data have linked chemical exposures to obesity. As organismal response to environmental exposures includes altered gene expression, identifying the regulatory epigenetic changes involved would be key to understanding the path from exposure to phenotype and provide new tools for exposure detection and risk assessment. In this report, we summarize published data linking early-life exposure to the heavy metals, cadmium and lead, to obesity. We also discuss potential mechanisms, as well as the need for complete coverage in epigenetic screening to fully identify alterations. The keys to understanding how metal exposure contributes to obesity are improved assessment of exposure and comprehensive establishment of epigenetic profiles that may serve as markers for exposures.

Burosumab Therapy in Children with X-Linked Hypophosphatemia.

PubMed

Carpenter, Thomas O; Whyte, Michael P; Imel, Erik A; Boot, Annemieke M; Högler, Wolfgang; Linglart, Agnès; Padidela, Raja; Van't Hoff, William; Mao, Meng; Chen, Chao-Yin; Skrinar, Alison; Kakkis, Emil; San Martin, Javier; Portale, Anthony A

2018-05-24

X-linked hypophosphatemia is characterized by increased secretion of fibroblast growth factor 23 (FGF-23), which leads to hypophosphatemia and consequently rickets, osteomalacia, and skeletal deformities. We investigated burosumab, a monoclonal antibody that targets FGF-23, in patients with X-linked hypophosphatemia. In an open-label, phase 2 trial, we randomly assigned 52 children with X-linked hypophosphatemia, in a 1:1 ratio, to receive subcutaneous burosumab either every 2 weeks or every 4 weeks; the dose was adjusted to achieve a serum phosphorus level at the low end of the normal range. The primary end point was the change from baseline to weeks 40 and 64 in the Thacher rickets severity total score (ranging from 0 to 10, with higher scores indicating greater disease severity). In addition, the Radiographic Global Impression of Change was used to evaluate rachitic changes from baseline to week 40 and to week 64. Additional end points were changes in pharmacodynamic markers, linear growth, physical ability, and patient-reported outcomes and the incidence of adverse events. The mean Thacher rickets severity total score decreased from 1.9 at baseline to 0.8 at week 40 with every-2-week dosing and from 1.7 at baseline to 1.1 at week 40 with every-4-week dosing (P<0.001 for both comparisons); these improvements persisted at week 64. The mean serum phosphorus level increased after the first dose in both groups, and more than half the patients in both groups had levels within the normal range (3.2 to 6.1 mg per deciliter [1.0 to 2.0 mmol per liter]) by week 6. Stable serum phosphorus levels were maintained through week 64 with every-2-week dosing. Renal tubular phosphate reabsorption increased from baseline in both groups, with an overall mean increase of 0.98 mg per deciliter (0.32 mmol per liter). The mean dose of burosumab at week 40 was 0.98 mg per kilogram of body weight with every-2-week dosing and 1.50 mg per kilogram with every-4-week dosing. Across both

Examining the influence of link function misspecification in conventional regression models for developing crash modification factors.

PubMed

Wu, Lingtao; Lord, Dominique

2017-05-01

This study further examined the use of regression models for developing crash modification factors (CMFs), specifically focusing on the misspecification in the link function. The primary objectives were to validate the accuracy of CMFs derived from the commonly used regression models (i.e., generalized linear models or GLMs with additive linear link functions) when some of the variables have nonlinear relationships and quantify the amount of bias as a function of the nonlinearity. Using the concept of artificial realistic data, various linear and nonlinear crash modification functions (CM-Functions) were assumed for three variables. Crash counts were randomly generated based on these CM-Functions. CMFs were then derived from regression models for three different scenarios. The results were compared with the assumed true values. The main findings are summarized as follows: (1) when some variables have nonlinear relationships with crash risk, the CMFs for these variables derived from the commonly used GLMs are all biased, especially around areas away from the baseline conditions (e.g., boundary areas); (2) with the increase in nonlinearity (i.e., nonlinear relationship becomes stronger), the bias becomes more significant; (3) the quality of CMFs for other variables having linear relationships can be influenced when mixed with those having nonlinear relationships, but the accuracy may still be acceptable; and (4) the misuse of the link function for one or more variables can also lead to biased estimates for other parameters. This study raised the importance of the link function when using regression models for developing CMFs. Copyright © 2017 Elsevier Ltd. All rights reserved.

X-linked dominant retinitis pigmentosa in an American family

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGuire, R.E.; Daiger, S.P.; Blanton, S.H.

1994-09-01

Retinitis pigmentosa is a genetically heterogeneous disease with autosomal dominant (adRP), autosomal recessive and X-linked forms. At least 3 forms of X-linked retinitis pigmentosa have been reported: RP2 which maps to Xp11.4-p 11.23, RP3 which maps to Xp21.1 and RP6, which maps to Xp21.3-p21.1. The X-linked forms of retinitis pigmentosa are generally considered to be recessive as female carriers are not affected or are much less affected than males. Here we report a five generation American family with X-linked retinitis pigmentosa in which both males and females are significantly affected. The disease locus in this family appears to be distinctmore » from RP2 and RP3. The American family (UTAD054) presents with early-onset retinitis pigmentosa. The family appeared to fit an autosomal dominant pattern; however, linkage testing excluded all known adRP loci. Absence of male-to-male transmission in the pedigree suggested the possibility of X-linked dominant inheritance. Thus we tested six microsatellite markers that map to Xp (DXS987, DXS989, DXS993, DXS999, DXS1003 and DXS1110). Of these, DXS989 showed tight linkage with one allele (199) showing a 100% concordance with disease status. The odds favoring an X-linked dominant mode of inheritance in this family, versus autosomal dominant, are 10{sup 5}:1. In addition, recombinations for DXS999, and dXS1110, the two markers flanking DXS989, were observed in affected individuals. These data map the disease locus in this family to a 9 mb region on the X chromosome between Xp22.11 and Xp21.41. In addition, the recombinant individuals exclude close linkage to RP2 and RP3. The observance of high penetrance in females indicates that this family has X-linked dominant retinitis pigmentosa. We suggest that this mode of inheritance should be considered in other families with dominant retinitis pigmentosa but an absence of male-to-male transmission.« less

Real time data acquisition of a countrywide commercial microwave link network

NASA Astrophysics Data System (ADS)

Chwala, Christian; Keis, Felix; Kunstmann, Harald

2015-04-01

Research in recent years has shown that data from commercial microwave link networks can provide very valuable precipitation information. Since these networks comprise the backbone of the cell phone network, they provide countrywide coverage. However acquiring the necessary data from the network operators is still difficult. Data is usually made available for researchers with a large time delay and often at irregular basis. This of course hinders the exploitation of commercial microwave link data in operational applications like QPE forecasts running at national meteorological services. To overcome this, we have developed a custom software in joint cooperation with our industry partner Ericsson. The software is installed on a dedicated server at Ericsson and is capable of acquiring data from the countrywide microwave link network in Germany. In its current first operational testing phase, data from several hundred microwave links in southern Germany is recorded. All data is instantaneously sent to our server where it is stored and organized in an emerging database. Time resolution for the Ericsson data is one minute. The custom acquisition software, however, is capable of processing higher sampling rates. Additionally we acquire and manage 1 Hz data from four microwave links operated by the skiing resort in Garmisch-Partenkirchen. We will present the concept of the data acquisition and show details of the custom-built software. Additionally we will showcase the accessibility and basic processing of real time microwave link data via our database web frontend.

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…

Linking main-belt comets to asteroid families

NASA Astrophysics Data System (ADS)

Novakovic, B.; Hsieh, H. H.; Cellino, A.

2012-09-01

Here we present our results obtained by applying different methods in order to establish a firm link between the main-belt comets (MBCs) and colisionally-formed asteroid families (AFs), i.e, to possibly find additional line of evidence supporting the hypothesis that MBCs may be preferentially found among the members of young AFs.

Elevated blood lead levels and reading readiness at the start of kindergarten.

PubMed

McLaine, Pat; Navas-Acien, Ana; Lee, Rebecca; Simon, Peter; Diener-West, Marie; Agnew, Jacqueline

2013-06-01

To evaluate the relationship between blood lead levels (BLLs) and reading readiness at kindergarten entry, an early marker of school performance, in a diverse urban school population. Kindergarten reading readiness test scores for children attending public kindergarten in Providence, Rhode Island, were linked to state health department records of blood lead testing by using individual identifiers. The study population (N = 3406) was 59% Hispanic. For each child, the geometric mean BLL was estimated by using all previously reported BLLs. Analyses were adjusted for gender, age, year enrolled, race, child language, and free/reduced lunch status as a measure of socioeconomic status. The median geometric mean BLL was 4.2 µg/dL; 20% of children had at least 1 venous BLL ≥10 µg/dL. Compared with children with BLLs <5 µg/dL, the adjusted prevalence ratios (95% confidence interval [CI]) for failing to achieve the national benchmark for reading readiness were 1.21 (1.19 to 1.23) and 1.56 (1.51 to 1.60) for children with BLLs of 5 to 9 and ≥10 µg/dL, respectively. On average, reading readiness scores decreased by 4.5 (95% CI: -2.9 to -6.2) and 10.0 (95% CI: -7.0 to -13.3) points for children with BLLs of 5 to 9 and ≥10 µg/dL, respectively, compared with BLLs <5 µg/dL. BLLs well below 10 µg/dL were associated with lower reading readiness at kindergarten entry. The high prevalence of elevated BLLs warrants additional investigation in other high-risk US populations. Results suggest benefits from additional collaboration between public health, public education, and community data providers.

Co-occurring nonnative woody shrubs have additive and non-additive soil legacies.

PubMed

Kuebbing, Sara E; Patterson, Courtney M; Classen, Aimée T; Simberloff, Daniel

2016-09-01

To maximize limited conservation funds and prioritize management projects that are likely to succeed, accurate assessment of invasive nonnative species impacts is essential. A common challenge to prioritization is a limited knowledge of the difference between the impacts of a single nonnative species compared to the impacts of nonnative species when they co-occur, and in particular predicting when impacts of co-occurring nonnative species will be non-additive. Understanding non-additivity is important for management decisions because the management of only one co-occurring invader will not necessarily lead to a predictable reduction in the impact or growth of the other nonnative plant. Nonnative plants are frequently associated with changes in soil biotic and abiotic characteristics, which lead to plant-soil interactions that influence the performance of other species grown in those soils. Whether co-occurring nonnative plants alter soil properties additively or non-additively relative to their effects on soils when they grow in monoculture is rarely addressed. We use a greenhouse plant-soil feedback experiment to test for non-additive soil impacts of two common invasive nonnative woody shrubs, Lonicera maackii and Ligustrum sinense, in deciduous forests of the southeastern United States. We measured the performance of each nonnative shrub, a native herbaceous community, and a nonnative woody vine in soils conditioned by each shrub singly or together in polyculture. Soils conditioned by both nonnative shrubs had non-additive impacts on native and nonnative performance. Root mass of the native herbaceous community was 1.5 times lower and the root mass of the nonnative L. sinense was 1.8 times higher in soils conditioned by both L. maackii and L. sinense than expected based upon growth in soils conditioned by either shrub singly. This result indicates that when these two nonnative shrubs co-occur, their influence on soils disproportionally favors persistence

An interannual link between Arctic sea-ice cover and the North Atlantic Oscillation

NASA Astrophysics Data System (ADS)

Caian, Mihaela; Koenigk, Torben; Döscher, Ralf; Devasthale, Abhay

2018-01-01

This work investigates links between Arctic surface variability and the phases of the winter (DJF) North Atlantic Oscillation (NAO) on interannual time-scales. The analysis is based on ERA-reanalysis and model data from the EC-Earth global climate model. Our study emphasizes a mode of sea-ice cover variability that leads the NAO index by 1 year. The mechanism of this leading is based on persistent surface forcing by quasi-stationary meridional thermal gradients. Associated thermal winds lead a slow adjustment of the pressure in the following winter, which in turn feeds-back on the propagation of sea-ice anomalies. The pattern of the sea-ice mode leading NAO has positive anomalies over key areas of South-Davis Strait-Labrador Sea, the Barents Sea and the Laptev-Ohkostsk seas, associated to a high pressure anomaly over the Canadian Archipelago-Baffin Bay and the Laptev-East-Siberian seas. These anomalies create a quasi-annular, quasi-steady, positive gradient of sea-ice anomalies about coastal line (when leading the positive NAO phase) and force a cyclonic vorticity anomaly over the Arctic in the following winter. During recent decades in spite of slight shifts in the modes' spectral properties, the same leading mechanism remains valid. Encouraging, actual models appear to reproduce the same mechanism leading model's NAO, relative to model areas of persistent surface forcing. This indicates that the link between sea-ice and NAO could be exploited as a potential skill-source for multi-year prediction by addressing the key problem of initializing the phase of the NAO/AO (Arctic Oscillation).

Recombination changes at the boundaries of fully and partially sex-linked regions between closely related Silene species pairs

PubMed Central

Campos, J L; Qiu, S; Guirao-Rico, S; Bergero, R; Charlesworth, D

2017-01-01

The establishment of a region of suppressed recombination is a critical change during sex chromosome evolution, leading to such properties as Y (and W) chromosome genetic degeneration, accumulation of repetitive sequences and heteromorphism. Although chromosome inversions can cause large regions to have suppressed recombination, and inversions are sometimes involved in sex chromosome evolution, gradual expansion of the non-recombining region could potentially sometimes occur. We here test whether closer linkage has recently evolved between the sex-determining region and several genes that are partially sex-linked in Silene latifolia, using Silene dioica, a closely related dioecious plants whose XY sex chromosome system is inherited from a common ancestor. The S. latifolia pseudoautosomal region (PAR) includes several genes extremely closely linked to the fully Y-linked region. These genes were added to an ancestral PAR of the sex chromosome pair in two distinct events probably involving translocations of autosomal genome regions causing multiple genes to become partially sex-linked. Close linkage with the PAR boundary must have evolved since these additions, because some genes added in both events now show almost complete sex linkage in S. latifolia. We compared diversity patterns of five such S. latifolia PAR boundary genes with their orthologues in S. dioica, including all three regions of the PAR (one gene that was in the ancestral PAR and two from each of the added regions). The results suggest recent recombination suppression in S. latifolia, since its split from S. dioica. PMID:27827389

Detection of lead nanoparticles in game meat by single particle ICP-MS following use of lead-containing bullets.

PubMed

Kollander, Barbro; Widemo, Fredrik; Ågren, Erik; Larsen, Erik H; Loeschner, Katrin

2017-03-01

This study investigated whether game meat may contain nanoparticles of lead from ammunition. Lead nanoparticles in the range 40 to 750 nm were detected by ICP-MS in single particle mode in game shot with lead-containing bullets. The median diameter of the detected nanoparticles was around 60 nm. The particle mass concentration ranged from 290 to 340 ng/g meat and the particle number concentrations from 27 to 50 million particles/g meat. The size limit of detection strongly depended on the level of dissolved lead and was in the range of 40 to 80 nm. In game meat sampled more than 10 cm away from the wound channel, no lead particles with a diameter larger than 40 nm were detected. In addition to dissolved lead in meat that originated from particulates, the presence of lead nano particles in game meat represents a hitherto unattended source of lead with a largely unknown toxicological impact to humans. Graphical Abstract Detection of lead nanoparticles in game meat by single particle ICP-MS following use of leadcontaining bullets.

Efficacy of a lead based paint XRF analyzer and a commercially available colorimetric lead test kit as qualitative field tools for determining presence of lead in religious powders.

PubMed

Shah, Manthan P; Shendell, Derek G; Meng, Qingyu; Ohman-Strickland, Pamela; Halperin, William

2018-04-23

The performances of a portable X-Ray Fluorescence (XRF) lead paint analyzer (RMD LPA-1, Protec Instrument Corp., Waltham, MA) and a commercially available colorimetric lead test kit (First Alert Lead Test Kit, eAccess Solutions, Inc., Palatine, IL) were evaluated for use by local or state health departments as potential cost-effective rapid analysis or "spot test" field techniques for tentative identification of lead content in sindoor powders. For both field-sampling methods, sensitivity, specificity and predictive values varied widely for samples containing <300,000 μg/g lead. For samples containing ≥300,000 μg/g lead, the aforementioned metrics were 100% (however, the CIs had a wide range). In addition, both field sampling methods showed clear, consistent positive readings only for samples containing ≥300,000 μg/g lead. Even samples with lead content as high as 5,110 μg/g were not positively identified by either field analysis technique. The results of this study suggest the XRF analyzer and colorimetric lead test kit cannot be used as a rapid field test for sindoor by health department inspectors.

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

PubMed

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

2016-07-01

Lead thiocyanate in the perovskite precursor can increase the grain size of a perovskite thin film and reduce the conductivity of the grain boundaries, leading to perovskite solar cells with reduced hysteresis and enhanced fill factor. A planar perovskite solar cell with grain boundary and interface passivation achieves a steady-state efficiency of 18.42%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The mechanism of collagen cross-linking in diabetes: a puzzle nearing resolution.

PubMed

Monnier, V M; Glomb, M; Elgawish, A; Sell, D R

1996-07-01

Considerable interest has been focused in recent years on the mechanism of collagen cross-linking by high glucose in vitro and in vivo. Experiments in both diabetic humans and in animals have shown that over time collagen becomes less soluble, less digestible by collagenase, more stable to heat-induced denaturation, and more glycated. In addition, collagen becomes more modified by advanced products of the Maillard reaction, i.e., immunoreactive advanced glycation end products and the glycoxidation markers carboxymethyllysine and pentosidine. Mechanistic studies have shown that collagen cross-linking in vitro can be uncoupled from glycation by the use of antioxidants and chelating agents. Experiments in the authors' laboratory revealed that approximately 50% of carboxymethyllysine formed in vitro originates from pathways other than oxidation of Amadori products, i.e., most likely the oxidation of Schiff base-linked glucose. In addition, the increase in thermal stability of rat tail tendons exposed to high glucose in vitro or in vivo was found to strongly depend on H2O2 formation. The final missing piece of the puzzle is that of the structure of the major cross-link. We speculate that it is a nonfluorescent nonultraviolet active cross-link between two lysine residues, which includes a fragmentation product of glucose linked in a nonreducible bond labile to both strong acids and bases.

Determination of Lead in Blood by Atomic Absorption Spectrophotometry1

PubMed Central

Selander, Stig; Cramér, Kim

1968-01-01

Lead in blood was determined by atomic absorption spectrophotometry, using a wet ashing procedure and a procedure in which the proteins were precipitated with trichloroacetic acid. In both methods the lead was extracted into isobutylmethylketone before measurement, using ammonium pyrrolidine dithiocarbamate as chelator. The simpler precipitation procedure was shown to give results identical with those obtained with the ashing technique. In addition, blood specimens were examined by the precipitation method and by spectral analysis, which method includes wet ashing of the samples, with good agreement. All analyses were done on blood samples from `normal' persons or from lead-exposed workers, and no additions of inorganic lead were made. The relatively simple protein precipitation technique gave accurate results and is suitable for the large-scale control of lead-exposed workers. PMID:5663425

Does my step look big in this? A visual illusion leads to safer stepping behaviour.

PubMed

Elliott, David B; Vale, Anna; Whitaker, David; Buckley, John G

2009-01-01

Tripping is a common factor in falls and a typical safety strategy to avoid tripping on steps or stairs is to increase foot clearance over the step edge. In the present study we asked whether the perceived height of a step could be increased using a visual illusion and whether this would lead to the adoption of a safer stepping strategy, in terms of greater foot clearance over the step edge. The study also addressed the controversial question of whether motor actions are dissociated from visual perception. 21 young, healthy subjects perceived the step to be higher in a configuration of the horizontal-vertical illusion compared to a reverse configuration (p = 0.01). During a simple stepping task, maximum toe elevation changed by an amount corresponding to the size of the visual illusion (p<0.001). Linear regression analyses showed highly significant associations between perceived step height and maximum toe elevation for all conditions. The perceived height of a step can be manipulated using a simple visual illusion, leading to the adoption of a safer stepping strategy in terms of greater foot clearance over a step edge. In addition, the strong link found between perception of a visual illusion and visuomotor action provides additional support to the view that the original, controversial proposal by Goodale and Milner (1992) of two separate and distinct visual streams for perception and visuomotor action should be re-evaluated.

Development of beam leaded low power logic circuits

NASA Technical Reports Server (NTRS)

Smith, B. W.; Malone, F.

1972-01-01

The technologies of low power TTL and beam lead processing were merged into a single product family. This family offers the power and thermal advantages of low power(54L), while providing the additional reliability advantages of beam leads. The reduction in the power and heat levels also allows the system designer to take advantage, through beam lead, multichip assemblies, of increased package density to reduce system size and weight.

Macular hole in juvenile X-linked retinoschisis.

PubMed

Al-Swaina, Nayef; Nowilaty, Sawsan R

2013-10-01

An 18 year-old male with no antecedent of trauma, systemic syndrome or myopia was referred for surgical treatment of a full thickness macular hole in the left eye. A more careful inspection revealed discrete foveal cystic changes in the fellow eye and subtle peripheral depigmented retinal pigment epithelial changes in both eyes. A spectral-domain optical coherence tomography (SD-OCT) scan confirmed, in addition to the full thickness macular hole in the left eye, microcystic spaces in the nuclear layers of both retinae. The diagnosis of X-linked retinoschisis was confirmed with a full field electroretinogram displaying the typical negative ERG. Macular holes are uncommon in the young and those complicating X-linked retinoschisis are rare. This report highlights the importance of investigating the presence of a macular hole in a young patient and illustrates the clinical and SD-OCT clues beyond the foveal center which led to the correct diagnosis of X-linked juvenile retinoschisis.

Predicting missing links and identifying spurious links via likelihood analysis

NASA Astrophysics Data System (ADS)

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

2016-03-01

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

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

Precipitation links (PrecipLinks) - a prototype directory for precipitation information

NASA Technical Reports Server (NTRS)

Velanthapillia, Balendran; Stocker, Erich Franz

2006-01-01

This poster describes a web directory of research oriented precipitation links. In this era of sophisticated search engines and web agents, it might seem counterproductive to establish such a directory of links. However, entering precipitation into a search engine like google will yield over one million hits. To further exacerbate this situation many of the returned links are dead, duplicates of other links, incomplete, or only marginally related to research precipitation or even the broader precipitation area. Sometimes connecting the linked URL causes the browser to lose context and not be able to get back to the original page. Even using more sophisticated search engines query parameters or agents while reducing the overall return doesn't eliminate all of the other issues listed. As part of the development of the measurement-based Precipitation Processing System (PPS) that will support Tropical Rainfall Measuring Mission (TRMM) version 7 reprocessing and the Global Precipitation Measurement (GPM) mission a precipitation links (PrecipLinks) facility is being developed. PrecipLinks is intended to share locations of other sites that contain information or data pertaining to precipitation research. Potential contributors can log-on to the PrecipLinks website and register their site for inclusion in the directory. The price for inclusion is the requirement to place a link back to PrecipLinks on the webpage that is registered. This ensures that users will be able to easily get back to PrecipLinks regardless of any context issues that browsers might have. Perhaps more importantly users while visiting one site that they know can be referred to a location that has many others sites with which they might not be familiar. PrecipLinks is designed to have a very flat structure. This poster summarizes these categories (information, data, services) and the reasons for their selection. Providers may register multiple pages to which they wish to direct users. However, each page

Sex-linked dominant

MedlinePlus

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

Monetary benefits of preventing childhood lead poisoning with lead-safe window replacement.

PubMed

Nevin, Rick; Jacobs, David E; Berg, Michael; Cohen, Jonathan

2008-03-01

Previous estimates of childhood lead poisoning prevention benefits have quantified the present value of some health benefits, but not the costs of lead paint hazard control or the benefits associated with housing and energy markets. Because older housing with lead paint constitutes the main exposure source today in the US, we quantify health benefits, costs, market value benefits, energy savings, and net economic benefits of lead-safe window replacement (which includes paint stabilization and other measures). The benefit per resident child from improved lifetime earnings alone is $21,195 in pre-1940 housing and $8685 in 1940-59 housing (in 2005 dollars). Annual energy savings are $130-486 per housing unit, with or without young resident children, with an associated increase in housing market value of $5900-14,300 per housing unit, depending on home size and number of windows replaced. Net benefits are $4490-5,629 for each housing unit built before 1940, and $491-1629 for each unit built from 1940-1959, depending on home size and number of windows replaced. Lead-safe window replacement in all pre-1960 US housing would yield net benefits of at least $67 billion, which does not include many other benefits. These other benefits, which are shown in this paper, include avoided Attention Deficit Hyperactivity Disorder, other medical costs of childhood lead exposure, avoided special education, and reduced crime and juvenile delinquency in later life. In addition, such a window replacement effort would reduce peak demand for electricity, carbon emissions from power plants, and associated long-term costs of climate change.

Lightweight Biometric Sensing for Walker Classification Using Narrowband RF Links

PubMed Central

Liang, Zhuo-qian

2017-01-01

This article proposes a lightweight biometric sensing system using ubiquitous narrowband radio frequency (RF) links for path-dependent walker classification. The fluctuated received signal strength (RSS) sequence generated by human motion is used for feature representation. To capture the most discriminative characteristics of individuals, a three-layer RF sensing network is organized for building multiple sampling links at the most common heights of upper limbs, thighs, and lower legs. The optimal parameters of sensing configuration, such as the height of link location and number of fused links, are investigated to improve sensory data distinctions among subjects, and the experimental results suggest that the synergistic sensing by using multiple links can contribute a better performance. This is the new consideration of using RF links in building a biometric sensing system. In addition, two types of classification methods involving vector quantization (VQ) and hidden Markov models (HMMs) are developed and compared for closed-set walker recognition and verification. Experimental studies in indoor line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios are conducted to validate the proposed method. PMID:29206188

Lightweight Biometric Sensing for Walker Classification Using Narrowband RF Links.

PubMed

Liu, Tong; Liang, Zhuo-Qian

2017-12-05

This article proposes a lightweight biometric sensing system using ubiquitous narrowband radio frequency (RF) links for path-dependent walker classification. The fluctuated received signal strength (RSS) sequence generated by human motion is used for feature representation. To capture the most discriminative characteristics of individuals, a three-layer RF sensing network is organized for building multiple sampling links at the most common heights of upper limbs, thighs, and lower legs. The optimal parameters of sensing configuration, such as the height of link location and number of fused links, are investigated to improve sensory data distinctions among subjects, and the experimental results suggest that the synergistic sensing by using multiple links can contribute a better performance. This is the new consideration of using RF links in building a biometric sensing system. In addition, two types of classification methods involving vector quantization (VQ) and hidden Markov models (HMMs) are developed and compared for closed-set walker recognition and verification. Experimental studies in indoor line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios are conducted to validate the proposed method.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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 previousmore » 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.« less

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

PubMed Central

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

1998-01-01

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

Advanced Sodium Ion Battery Anode Constructed via Chemical Bonding between Phosphorus, Carbon Nanotube, and Cross-Linked Polymer Binder.

PubMed

Song, Jiangxuan; Yu, Zhaoxin; Gordin, Mikhail L; Li, Xiaolin; Peng, Huisheng; Wang, Donghai

2015-12-22

Maintaining structural stability is a great challenge for high-capacity conversion electrodes with large volume change but is necessary for the development of high-energy-density, long-cycling batteries. Here, we report a stable phosphorus anode for sodium ion batteries by the synergistic use of chemically bonded phosphorus-carbon nanotube (P-CNT) hybrid and cross-linked polymer binder. The P-CNT hybrid was synthesized through ball-milling of red phosphorus and carboxylic group functionalized carbon nanotubes. The P-O-C bonds formed in this process help maintain contact between phosphorus and CNTs, leading to a durable hybrid. In addition, cross-linked carboxymethyl cellulose-citric acid binder was used to form a robust electrode. As a result, this anode delivers a stable cycling capacity of 1586.2 mAh/g after 100 cycles, along with high initial Coulombic efficiency of 84.7% and subsequent cycling efficiency of ∼99%. The unique electrode framework through chemical bonding strategy reported here is potentially inspirable for other electrode materials with large volume change in use.

Arp2/3 Complex from Acanthamoeba Binds Profilin and Cross-links Actin Filaments

PubMed Central

Mullins, R. Dyche; Kelleher, Joseph F.; Xu, James; Pollard, Thomas D.

1998-01-01

The Arp2/3 complex was first purified from Acanthamoeba castellanii by profilin affinity chromatography. The mechanism of interaction with profilin was unknown but was hypothesized to be mediated by either Arp2 or Arp3. Here we show that the Arp2 subunit of the complex can be chemically cross-linked to the actin-binding site of profilin. By analytical ultracentrifugation, rhodamine-labeled profilin binds Arp2/3 complex with a Kd of 7 μM, an affinity intermediate between the low affinity of profilin for barbed ends of actin filaments and its high affinity for actin monomers. These data suggest the barbed end of Arp2 is exposed, but Arp2 and Arp3 are not packed together in the complex exactly like two actin monomers in a filament. Arp2/3 complex also cross-links actin filaments into small bundles and isotropic networks, which are mechanically stiffer than solutions of actin filaments alone. Arp2/3 complex is concentrated at the leading edge of motile Acanthamoeba, and its localization is distinct from that of α-actinin, another filament cross-linking protein. Based on localization and actin filament nucleation and cross-linking activities, we propose a role for Arp2/3 in determining the structure of the actin filament network at the leading edge of motile cells. PMID:9529382

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…

Microbial Community Profile of a Lead Service Line Removed from a Drinking Water Distribution System▿

PubMed Central

White, Colin; Tancos, Matthew; Lytle, Darren A.

2011-01-01

A corroded lead service line was removed from a drinking water distribution system, and the microbial community was profiled using 16S rRNA gene techniques. This is the first report of the characterization of a biofilm on the surface of a corroded lead drinking water service line. The majority of phylotypes have been linked to heavy-metal-contaminated environments. PMID:21652741

An Overview of Links Between Obesity and Mental Health.

PubMed

Avila, Christian; Holloway, Alison C; Hahn, Margaret K; Morrison, Katherine M; Restivo, Maria; Anglin, Rebecca; Taylor, Valerie H

2015-09-01

The American Medical Association recently recognized obesity as both an illness and a leading cause of preventable death and chronic disease. This association is not only linked to physical health outcomes, however, as obesity has also been extensively associated with mental illness as well. Both obesity and severe mental illness decrease quality of life and are associated with an increase in disability, morbidity, and mortality, and when they occur together, these adverse health outcomes are magnified. Despite educational campaigns, increased awareness, and improved treatment options, the high prevalence of mental illness and comorbid obesity remains a serious problem. This review examines this overlap, highlighting clinical and biological factors that have been linked to this association in order to improve our understanding and help elucidate potential therapeutic avenues.

X-Linked Retinoschisis: Phenotypic Variability in a Chinese Family

PubMed Central

Xiao, Yangyan; Liu, Xiao; Tang, Luosheng; Wang, Xia; Coursy, Terry; Guo, Xiaojian; Li, Zhuo

2016-01-01

X-linked juvenile retinoschisis (XLRS), a leading cause of juvenile macular degeneration, is characterized by a spoke-wheel pattern in the macular region of the retina and splitting of the neurosensory retina. Our study is to describe the clinical characteristics of a four generations of this family (a total of 18 members)with X-linked retinoschisis (XLRS) and detected a novel mutations of c.3G > A (p.M1?) in the initiation codon of the RS1 gene. by direct sequencing.Identification of this mutation in this family provides evidence about potential genetic or environmental factors on its phenotypic variance, as patients presented with different phenotypes regardless of having the same mutation. Importantly, OCT has proven vital for XLRS diagnosis in children. PMID:26823236

X-Linked Retinoschisis: Phenotypic Variability in a Chinese Family.

PubMed

Xiao, Yangyan; Liu, Xiao; Tang, Luosheng; Wang, Xia; Coursey, Terry G; Coursy, Terry; Guo, Xiaojian; Li, Zhuo

2016-01-29

X-linked juvenile retinoschisis (XLRS), a leading cause of juvenile macular degeneration, is characterized by a spoke-wheel pattern in the macular region of the retina and splitting of the neurosensory retina. Our study is to describe the clinical characteristics of a four generations of this family (a total of 18 members)with X-linked retinoschisis (XLRS) and detected a novel mutations of c.3G > A (p.M1?) in the initiation codon of the RS1 gene. by direct sequencing.Identification of this mutation in this family provides evidence about potential genetic or environmental factors on its phenotypic variance, as patients presented with different phenotypes regardless of having the same mutation. Importantly, OCT has proven vital for XLRS diagnosis in children.

Performance Analysis of the Link-16/JTIDS Waveform With Concatenated Coding

DTIC Science & Technology

2009-09-01

noncoherent demodulation in terms of both required signal power and throughput. 15. NUMBER OF PAGES 101 14. SUBJECT TERMS Link-16/JTIDS, Reed-Solomon...Pulsed-Noise Interference (PNI), Additive White Gaussian Noise (AWGN), coherent detection, noncoherent detection. 16. PRICE CODE 17. SECURITY...than the existing Link-16/JTIDS waveform in both AWGN and PNI, for both coherent and noncoherent demodulation, in terms of both required signal

Hydrogen Peroxide Activated Quinone Methide Precursors with Enhanced DNA Cross-Linking Capability and Cytotoxicity towards Cancer Cells

PubMed Central

Wang, Yibin; Fan, Heli; Balakrishnan, Kumudha; Lin, Zechao; Cao, Sheng; Chen, Wenbing; Fan, Yukai; Guthrie, Quibria A.; Sun, Huabing; Teske, Kelly A.; Gandhi, Varsha; Arnold, Leggy A.; Peng, Xiaohua

2017-01-01

Quinone methide (QM) formation induced by endogenously generated H2O2 is attractive for biological and biomedical applications. To overcome current limitations due to low biological activity of H2O2-activated QM precursors, we are introducing herein several new arylboronates with electron donating substituents at different positions of benzene ring and/or different neutral leaving groups. The reaction rate of the arylboronate esters with H2O2 and subsequent bisquinone methides formation and DNA cross-linking was accelerated with the application of Br as a leaving group instead of acetoxy groups. Additionally, a donating group placed meta to the nascent exo-methylene group of the quinone methide greatly improves H2O2-induced DNA interstrand cross-link formation as well as enhances the cellular activity. Multiple donating groups decrease the stability and DNA cross-linking capability, which lead to low cellular activity. A cell-based screen demonstrated that compounds 2a and 5a with a OMe or OH group dramatically inhibited the growth of various tissue-derived cancer cells while normal cells were less affected. Induction of H2AX phosphorylation by these compounds in CLL lymphocytes provide evidence for a correlation between cell death and DNA damage. The compounds presented herein showed potent anticancer activities and selectivity, which represent a novel scaffold for anticancer drug development. PMID:28388522

Aggregate-level lead exposure, gun violence, homicide, and rape.

PubMed

Boutwell, Brian B; Nelson, Erik J; Qian, Zhengmin; Vaughn, Michael G; Wright, John P; Beaver, Kevin M; Barnes, J C; Petkovsek, Melissa; Lewis, Roger; Schootman, Mario; Rosenfeld, Richard

2017-01-01

An increasing body of research has linked the geographic distribution of lead with various indicators of criminal and antisocial behavior. The current study, using data from an ongoing project related to lead exposure in St. Louis City, MO, analyzed the association between aggregate blood lead levels and specific indicators violent crime within the city. Ecological study. St. Louis, Missouri. Blood lead levels. Official reports of violent crimes were categorized as 1) crimes involving a firearm (yes/no), 2) assault crimes (with or without a firearm), 3) robbery crimes (with or without a firearm), 4) homicides and 5) rape. With the exception of rape, aggregate blood-lead levels were statistically significant predictors of violent crime at the census tract level. The risk ratios for each of the outcome measures were as follows: firearm crimes 1.03 (1.03-1.04), assault crimes 1.03 (1.02-1.03), robbery crimes 1.03 (1.02-1.04), homicide 1.03 (1.01, 1.04), and rape 1.01 (0.99-1.03). Extending prior research in St. Louis, results suggest that aggregated lead exposure at the census tract level predicted crime outcomes, even after accounting for important sociological variables. Moving forward, a more developed understanding of aggregate level crime may necessitate a shift toward studying the synergy between sociological and biological risk factors such as lead exposure.

Parkinson's disease and periodontitis - the missing link? A review.

PubMed

Kaur, Tejaswani; Uppoor, Ashita; Naik, Dilip

2016-12-01

In this article an attempt has been made to postulate a possible link between Parkinson's disease and periodontal disease. Various systemic diseases such as cardiac disease, diabetes, renal diseases, low birth weight and Alzheimer's disease have been proposed to be linked with periodontal disease on the basis of systemic inflammation. Parkinson's disease is a chronic progressive neurodegenerative disorder with multifactorial aetiology. Until now, periodontal disease and Parkinson's disease has been linked only on the basis of poor motor and cognitive control in Parkinson's patient which leads to poor oral health maintenance. Evidence now suggests that chronic neuroinflammation is consistently associated with the pathophysiology of Parkinson's disease. Also, recently, systemic inflammation has been suggested as one of the contributing factors for neurodegeneration. Dental and medical literature especially those dealing with neurosciences were selected which highlighted the link between systemic inflammation and infection. So far there is no direct evidence implicating an effect of periodontitis in the pathogenesis of Parkinson's disease. To clarify this link, studies on population based case-control or cohort design are needed. This would be especially significant in the present era where there is paucity for preventive measures as far as a cognitive disorder such as Parkinson's disease is concerned. We cannot cure Parkinson's disease, but if in future this missing link is established, an attempt can be made to prevent it by tackling one of its possible contributors (periodontitis) for systemic inflammation by simple preventive oral hygiene measures. © 2015 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

Analytical model and figures of merit for filtered Microwave Photonic Links.

PubMed

Gasulla, Ivana; Capmany, José

2011-09-26

The concept of filtered Microwave Photonic Links is proposed in order to provide the most general and versatile description of complex analog photonic systems. We develop a field propagation model where a global optical filter, characterized by its optical transfer function, embraces all the intermediate optical components in a linear link. We assume a non-monochromatic light source characterized by an arbitrary spectral distribution which has a finite linewidth spectrum and consider both intensity modulation and phase modulation with balanced and single detection. Expressions leading to the computation of the main figures of merit concerning the link gain, noise and intermodulation distortion are provided which, to our knowledge, are not available in the literature. The usefulness of this derivation resides in the capability to directly provide performance criteria results for complex links just by substituting in the overall closed-form formulas the numerical or measured optical transfer function characterizing the link. This theory is presented thus as a potential tool for a wide range of relevant microwave photonic application cases which is extendable to multiport radio over fiber systems. © 2011 Optical Society of America

Lead stabilization by phosphate amendments in soil impacted by paint residue.

PubMed

Schwab, A P; Lewis, K; Banks, M K

2006-01-01

The addition of phosphate was evaluated for contaminant stabilization in soils impacted by lead paint residue. Soils sampled from 15 highway bridge sites in Indiana were screened based on residual lead concentrations from paint contamination. Two appropriate bridge sites were identified in Tippecanoe County, Indiana. Soluble phosphate was added to the soil at a mole ratio of 3:1 P:Pb. The efficacy of phosphate treatment was evaluated by a physiologically based extraction test (PBET), uptake of lead by sunflowers, and leaching of lead from soil columns. Sunflowers were established on both field sites, and the mean Pb concentration in the above-ground biomass indicated that the rate of uptake was similar to plants growing in uncontaminated soil. The second bioavailability assessment was the physiologically based extraction test, designed to evaluate heavy metal availability during ingestion. After 1 year at both sites, the addition of phosphate significantly reduced the concentrations of lead extracted by PBET, indicating that the lead in the amended soils had lower bioavailability than in the unamended soils. In the column study, the contaminated soil produced the highest mass of leached Pb, and the addition of P reduced the mass of Pb in the leachate to similar levels found in the uncontaminated soil. Overall, the addition of soluble phosphate to these soils appears to be an effective approach for immobilizing Pb and reducing the associated bio-accessibility.

A novel multilayer model for missing link prediction and future link forecasting in dynamic complex networks

NASA Astrophysics Data System (ADS)

Yasami, Yasser; Safaei, Farshad

2018-02-01

The traditional complex network theory is particularly focused on network models in which all network constituents are dealt with equivalently, while fail to consider the supplementary information related to the dynamic properties of the network interactions. This is a main constraint leading to incorrect descriptions of some real-world phenomena or incomplete capturing the details of certain real-life problems. To cope with the problem, this paper addresses the multilayer aspects of dynamic complex networks by analyzing the properties of intrinsically multilayered co-authorship networks, DBLP and Astro Physics, and presenting a novel multilayer model of dynamic complex networks. The model examines the layers evolution (layers birth/death process and lifetime) throughout the network evolution. Particularly, this paper models the evolution of each node's membership in different layers by an Infinite Factorial Hidden Markov Model considering feature cascade, and thereby formulates the link generation process for intra-layer and inter-layer links. Although adjacency matrixes are useful to describe the traditional single-layer networks, such a representation is not sufficient to describe and analyze the multilayer dynamic networks. This paper also extends a generalized mathematical infrastructure to address the problems issued by multilayer complex networks. The model inference is performed using some Markov Chain Monte Carlo sampling strategies, given synthetic and real complex networks data. Experimental results indicate a tremendous improvement in the performance of the proposed multilayer model in terms of sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios, F1-score, Matthews correlation coefficient, and accuracy for two important applications of missing link prediction and future link forecasting. The experimental results also indicate the strong predictivepower of the proposed model for the application of

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.

Nutrition and lead: Strategies for public health

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahaffey, K.R.

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

LFR "Lead-Cooled Fast Reactor"

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cinotti, L; Fazio, C; Knebel, J

2006-05-11

The main purpose of this paper is to present the current status of development of the Lead-cooled Fast Reactor (LFR) in Generation IV (GEN IV), including the European contribution, to identify needed R&D and to present the corresponding GEN IV International Forum (GIF) R&D plan [1] to support the future development and deployment of lead-cooled fast reactors. The approach of the GIF plan is to consider the research priorities of each member country in proposing an integrated, coordinated R&D program to achieve common objectives, while avoiding duplication of effort. The integrated plan recognizes two principal technology tracks: (1) a small,more » transportable system of 10-100 MWe size that features a very long refuelling interval, and (2) a larger-sized system rated at about 600 MWe, intended for central station power generation. This paper provides some details of the important European contributions to the development of the LFR. Sixteen European organizations have, in fact, taken the initiative to present to the European Commission the proposal for a Specific Targeted Research and Training Project (STREP) devoted to the development of a European Lead-cooled System, known as the ELSY project; two additional organizations from the US and Korea have joined the project. Consequently, ELSY will constitute the reference system for the large lead-cooled reactor of GEN IV. The ELSY project aims to demonstrate the feasibility of designing a competitive and safe fast power reactor based on simple technical engineered features that achieves all of the GEN IV goals and gives assurance of investment protection. As far as new technology development is concerned, only a limited amount of R&D will be conducted in the initial phase of the ELSY project since the first priority is to define the design guidelines before launching a larger and expensive specific R&D program. In addition, the ELSY project is expected to benefit greatly from ongoing lead and lead-alloy technology

Dielectric Waveguides Splitter and Hybrid/Isolator for Bidirectional Link

NASA Technical Reports Server (NTRS)

Tang, Adrian Joseph (Inventor); Chattopadhyay, Goutam (Inventor); Chahat, Nacer E. (Inventor); Decrossas, Emmanuel (Inventor)

2016-01-01

A system, method, device, and apparatus provide a dielectric waveguide splitter/bi-directional link. A dielectric substrate fabricated into a first Y-junction waveguide with a first port splitting into a first branch leading to a second port and a second branch leading to a third port. An angle between the first branch and the second branch is below ninety degrees (90.degree.). The dielectric waveguide splitter enables millimeter-wave (mmWave) transmission between the first port and the second port while reducing feedback of the mmWave between the second and third port. Two Y-junction waveguides may be fabricated back-to-back to provide simultaneous bidirectional mmWave transmission at a single frequency.

LinkIT: a ludic elicitation game for eliciting risk perceptions.

PubMed

Cao, Yan; McGill, William L

2013-06-01

The mental models approach, a leading strategy to develop risk communications, involves a time- and labor-intensive interview process and a lengthy questionnaire to elicit group-level risk perceptions. We propose that a similarity ratings approach for structural knowledge elicitation can be adopted to assist the risk mental models approach. The LinkIT game, inspired by games with a purpose (GWAP) technology, is a ludic elicitation tool designed to elicit group understanding of the relations between risk factors in a more enjoyable and productive manner when compared to traditional approaches. That is, consistent with the idea of ludic elicitation, LinkIT was designed to make the elicitation process fun and enjoyable in the hopes of increasing participation and data quality in risk studies. Like the mental models approach, the group mental model obtained via the LinkIT game can hence be generated and represented in a form of influence diagrams. In order to examine the external validity of LinkIT, we conducted a study to compare its performance with respect to a more conventional questionnaire-driven approach. Data analysis results conclude that the two group mental models elicited from the two approaches are similar to an extent. Yet, LinkIT was more productive and enjoyable than the questionnaire. However, participants commented that the current game has some usability concerns. This presentation summarizes the design and evaluation of the LinkIT game and suggests areas for future work. © 2012 Society for Risk Analysis.

Link-topic model for biomedical abbreviation disambiguation.

PubMed

Kim, Seonho; Yoon, Juntae

2015-02-01

unigrams and semantically associated bigrams simultaneously. The addition of semantic links improves the disambiguation accuracy without removing irrelevant contextual words and reduces the parameter space of massive skipping or consecutive bigrams. The link topic model achieves 98.42% disambiguation accuracy on 73,505 MEDLINE abstracts with respect to 21 three letter abbreviations and their 139 distinct long forms. Copyright © 2014 Elsevier Inc. All rights reserved.

Dynamic Stall Characteristics of Drooped Leading Edge Airfoils

NASA Technical Reports Server (NTRS)

Sankar, Lakshmi N.; Sahin, Mehmet; Gopal, Naveen

2000-01-01

Helicopters in high-speed forward flight usually experience large regions of dynamic stall over the retreating side of the rotor disk. The rapid variations in the lift and pitching moments associated with the stall process can result in vibratory loads, and can cause fatigue and failure of pitch links. In some instances, the large time lag between the aerodynamic forces and the blade motion can trigger stall flutter. A number of techniques for the alleviation of dynamic stall have been proposed and studied by researchers. Passive and active control techniques have both been explored. Passive techniques include the use of high solidity rotors that reduce the lift coefficients of individual blades, leading edge slots and leading edge slats. Active control techniques include steady and unsteady blowing, and dynamically deformable leading edge (DDLE) airfoils. Considerable amount of experimental and numerical data has been collected on the effectiveness of these concepts. One concept that has not received as much attention is the drooped-leading edge airfoil idea. It has been observed in wind tunnel studies and flight tests that drooped leading edge airfoils can have a milder dynamic stall, with a significantly milder load hysteresis. Drooped leading edge airfoils may not, however, be suitable at other conditions, e.g. in hover, or in transonic flow. Work needs to be done on the analysis and design of drooped leading edge airfoils for efficient operation in a variety of flight regimes (hover, dynamic stall, and transonic flow). One concept that is worthy of investigation is the dynamically drooping airfoil, where the leading edge shape is changed roughly once-per-rev to mitigate the dynamic stall.

SciLinks

Science.gov Websites

SciLinks Forgot your login? Sign up for FREE access Log In I'm a ... Teacher Student User Name questions and satisfy their curiosity Learn More Sign up for Free Access Sites in the SciLinks program . SciLinks-Targeted, Grade-Specific Web Content for your Books Free web content to extend and expand student

Cell therapy for basement membrane-linked diseases.

PubMed

Nyström, Alexander; Bornert, Olivier; Kühl, Tobias

2017-01-01

For most disorders caused by mutations in genes encoding basement membrane (BM) proteins, there are at present only limited treatment options available. Genetic BM-linked disorders can be viewed as especially suited for treatment with cell-based therapy approaches because the proteins that need to be restored are located in the extracellular space. In consequence, complete and permanent engraftment of cells does not necessarily have to occur to achieve substantial causal therapeutic effects. For these disorders cells can be used as transient vehicles for protein replacement. In addition, it is becoming evident that BM-linked genetic disorders are modified by secondary diseases mechanisms. Cell-based therapies have also the ability to target such disease modifying mechanisms. Thus, cell therapies can simultaneously provide causal treatment and symptomatic relief, and accordingly hold great potential for treatment of BM-linked disorders. However, this potential has for most applications and diseases so far not been realized. Here, we will present the state of cell therapies for BM-linked diseases. We will discuss use of both pluripotent and differentiated cells, the limitation of the approaches, their challenges, and the way forward to potential wider implementation of cell therapies in the clinics. Copyright © 2016 Elsevier B.V. All rights reserved.

Analysis of Network Vulnerability Under Joint Node and Link Attacks

NASA Astrophysics Data System (ADS)

Li, Yongcheng; Liu, Shumei; Yu, Yao; Cao, Ting

2018-03-01

The security problem of computer network system is becoming more and more serious. The fundamental reason is that there are security vulnerabilities in the network system. Therefore, it’s very important to identify and reduce or eliminate these vulnerabilities before they are attacked. In this paper, we are interested in joint node and link attacks and propose a vulnerability evaluation method based on the overall connectivity of the network to defense this attack. Especially, we analyze the attack cost problem from the attackers’ perspective. The purpose is to find the set of least costs for joint links and nodes, and their deletion will lead to serious network connection damage. The simulation results show that the vulnerable elements obtained from the proposed method are more suitable for the attacking idea of the malicious persons in joint node and link attack. It is easy to find that the proposed method has more realistic protection significance.

SERPINE 1 Links Obesity and Diabetes: A Pilot Study

PubMed Central

Kaur, Punit; Reis, Michael D.; Couchman, Glen R.; Forjuoh, Samuel N.; Greene, John F.; Asea, Alexzander

2010-01-01

In the past decade there has been a dramatic increase in the number of Americans considered obese. Over this same period, the number of individuals diagnosed with diabetes has increased by over 40%. Interestingly, in a great number of cases individuals considered obese develop diabetes later on. Although a link between obesity and diabetes has been suggested, conclusive scientific evidence is thus far just beginning to emerge. The present pilot study is designed to identify a possible link between obesity and diabetes. The plasma proteome is a desirable biological sample due to their accessibility and representative complexity due, in part, to the wide dynamic range of protein concentrations, which lead to the discovery of new protein markers. Here we present the results for the specific depletion of 14 high-abundant proteins from the plasma samples of obese and diabetic patients. Comparative proteomic profiling of plasma from individuals with either diabetes or obesity and individuals with both obesity and diabetes revealed SERPINE 1 as a possible candidate protein of interest, which might be a link between obesity and diabetes. PMID:21113241

SERPINE 1 Links Obesity and Diabetes: A Pilot Study.

PubMed

Kaur, Punit; Reis, Michael D; Couchman, Glen R; Forjuoh, Samuel N; Greene, John F; Asea, Alexzander

2010-06-01

In the past decade there has been a dramatic increase in the number of Americans considered obese. Over this same period, the number of individuals diagnosed with diabetes has increased by over 40%. Interestingly, in a great number of cases individuals considered obese develop diabetes later on. Although a link between obesity and diabetes has been suggested, conclusive scientific evidence is thus far just beginning to emerge. The present pilot study is designed to identify a possible link between obesity and diabetes. The plasma proteome is a desirable biological sample due to their accessibility and representative complexity due, in part, to the wide dynamic range of protein concentrations, which lead to the discovery of new protein markers. Here we present the results for the specific depletion of 14 high-abundant proteins from the plasma samples of obese and diabetic patients. Comparative proteomic profiling of plasma from individuals with either diabetes or obesity and individuals with both obesity and diabetes revealed SERPINE 1 as a possible candidate protein of interest, which might be a link between obesity and diabetes.

Approach for Estimating Exposures and Incremental Health Effects from Lead Due to Renovation Repair and Painting Activities in Public and Commercial Buildings

EPA Pesticide Factsheets

Approach for Estimating Exposures and Incremental Health Effects from Lead Due to Renovation Repair and Painting Activities in Public and Commercial Buildings: links to documents at www.regulations.gov, links to PDFs related to Approach document

A Study of Cross-linked Regions of Poly(Vinyl Alcohol) Gels by Small-Angle Neutron Scattering

NASA Astrophysics Data System (ADS)

Lawrence, Mathias B.; Desa, J. A. E.; Aswal, V. K.

2011-07-01

A poly(vinyl alcohol)-borax cross-linked hydrogel has been studied by Small Angle Neutron Scattering as a function of borax concentration in the wave-vector transfer (Q) range of 0.017 Å-1 to 0.36 Å-1. It is found that as the concentration of borax increases, so does the intensity of scattering in this range. Beyond a borax concentration of 2 mg/ml, the increase in cross-linked PVA chains leads to cross-linked units larger than 150 Å as evidenced by a reduction in intensity in the lower Q region.

Aptamers as tools for target prioritization and lead identification.

PubMed

Burgstaller, Petra; Girod, Anne; Blind, Michael

2002-12-15

The increasing number of potential drug target candidates has driven the development of novel technologies designed to identify functionally important targets and enhance the subsequent lead discovery process. Highly specific synthetic nucleic acid ligands--also known as aptamers--offer a new exciting route in the drug discovery process by linking target validation directly with HTS. Recently, aptamers have proven to be valuable tools for modulating the function of endogenous cellular proteins in their natural environment. A set of technologies has been developed to use these sophisticated ligands for the validation of potential drug targets in disease models. Moreover, aptamers that are specific antagonists of protein function can act as substitute interaction partners in HTS assays to facilitate the identification of small-molecule lead compounds.

Loss of the homologous recombination gene rad51 leads to Fanconi anemia-like symptoms in zebrafish.

PubMed

Botthof, Jan Gregor; Bielczyk-Maczyńska, Ewa; Ferreira, Lauren; Cvejic, Ana

2017-05-30

RAD51 is an indispensable homologous recombination protein, necessary for strand invasion and crossing over. It has recently been designated as a Fanconi anemia (FA) gene, following the discovery of two patients carrying dominant-negative mutations. FA is a hereditary DNA-repair disorder characterized by various congenital abnormalities, progressive bone marrow failure, and cancer predisposition. In this report, we describe a viable vertebrate model of RAD51 loss. Zebrafish rad51 loss-of-function mutants developed key features of FA, including hypocellular kidney marrow, sensitivity to cross-linking agents, and decreased size. We show that some of these symptoms stem from both decreased proliferation and increased apoptosis of embryonic hematopoietic stem and progenitor cells. Comutation of p53 was able to rescue the hematopoietic defects seen in the single mutants, but led to tumor development. We further demonstrate that prolonged inflammatory stress can exacerbate the hematological impairment, leading to an additional decrease in kidney marrow cell numbers. These findings strengthen the assignment of RAD51 as a Fanconi gene and provide more evidence for the notion that aberrant p53 signaling during embryogenesis leads to the hematological defects seen later in life in FA. Further research on this zebrafish FA model will lead to a deeper understanding of the molecular basis of bone marrow failure in FA and the cellular role of RAD51.

Photoreversible Covalent Hydrogels for Soft-Matter Additive Manufacturing.

PubMed

Kabb, Christopher P; O'Bryan, Christopher S; Deng, Christopher C; Angelini, Thomas E; Sumerlin, Brent S

2018-05-16

Reversible covalent chemistry provides access to robust materials with the ability to be degraded and reformed upon exposure to an appropriate stimulus. Photoresponsive units are attractive for this purpose, as the spatial and temporal application of light is easily controlled. Coumarin derivatives undergo a [2 + 2] cycloaddition upon exposure to long-wave UV irradiation (365 nm), and this process can be reversed using short-wave UV light (254 nm). Therefore, polymers cross-linked by coumarin groups are excellent candidates as reversible covalent gels. In this work, copolymerization of coumarin-containing monomers with the hydrophilic comonomer N, N-dimethylacrylamide yielded water-soluble, linear polymers that could be cured with long-wave UV light into free-standing hydrogels, even in the absence of a photoinitiator. Importantly, the gels were reverted back to soluble copolymers upon short-wave UV irradiation. This process could be cycled, allowing for recycling and remolding of the hydrogel into additional shapes. Further, this hydrogel can be imprinted with patterns through a mask-based, post-gelation photoetching method. Traditional limitations of this technique, such as the requirement for uniform etching in one direction, have been overcome by combining these materials with a soft-matter additive manufacturing methodology. In a representative application of this approach, we printed solid structures in which the interior coumarin-cross-linked gel is surrounded by a nondegradable gel. Upon exposure to short-wave UV irradiation, the coumarin-cross-linked gel was reverted to soluble prepolymers that were washed away to yield hollow hydrogel objects.

Pb Neurotoxicity: Neuropsychological Effects of Lead Toxicity

PubMed Central

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. PMID:24516855

Genotypic analysis of X-linked retinoschisis in Western Australia.

PubMed

Lamey, Tina; Laurin, Sarina; Chelva, Enid; De Roach, John

2010-01-01

X-linked Retinoschisis is a leading cause of juvenile macular degeneration. Four Western Australian families affected by X-Linked Retinoschisis were analysed using DNA and clinical information from the Australian Inherited Retinal Disease (IRD) Register and DNA Bank. By direct sequencing of the RS1 gene, three genetic variants were identified; 52+1G > T, 289T > G and 416delA. 289T > G has not been previously reported and is likely to cause a substitution of a membrane binding residue (W92G) in the functional discoidin domain. All clinically diagnosed individuals showed typical electronegative ERGs. The 52+1G > T obligate carrier also recorded a bilaterally abnormal rod ERG and mildly abnormal photopic responses. mfERG trace arrays showed reduced response densities in the paramacular region extending futher temporally for each eye.

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.

Performance of 40-millimeter-bore ball bearings with lead- and lead-alloy-plated retainers in liquid hydrogen at 1.2 million DN

NASA Technical Reports Server (NTRS)

Brewe, D. E.; Wisander, D. W.; Scribbe, H. W.

1972-01-01

Forty-millimeter-bore ball bearings with lead- and lead-alloy-coated retainers were operated in liquid hydrogen at 30,000 rpm under a thrust load of 1780 N (400 lb.) Four different substrate materials were used for the retainer. Longer bearing run times were achieved with a lead-tin-copper alloy coating plated onto a leaded-bronze material (22.5 hr) and an aluminum-bronze alloy (19.3 hr). One bearing with a pure lead coating achieved the desired objective of 10 hr. This bearing had an aluminum - bronze substrate retainer and ran successfully for 12.4 hr. Additions of antimony to the lead provided an alloy coating with better wear resistance than pure lead; however, this coating was abrasive to the outer-race lands.

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

Lead contents in the surface enamel of deciduous teeth sampled in vivo from children in uncontaminated and in lead-contaminated areas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Almeida, Glauce Regina Costa de; Pereira Saraiva, Maria da Conceicao; Barbosa Jr, Fernando

2007-07-15

This study aimed to: (1) measure lead contents in the surface enamel of two populations consisting of 4-6-year-old children, one from an apparently uncontaminated area (Ribeirao Preto, Sao Paulo State, SP, Brazil, n=247) and the other from an area notoriously contaminated with lead (Bauru, Sao Paulo State, Brazil, n=26); (2) compare biopsy depths between the two populations; (3) correlate biopsy depth with lead content; (4) stratify samples according to biopsy depth to compare lead contents in samples from similar biopsy depths. A surface enamel acid-etch microbiopsy was performed in vivo on a single upper deciduous incisor for each sample. Leadmore » was measured by graphite furnace atomic absorption spectrometry (GFAAS) while phosphorus was measured colorimetrically to establish biopsy depth. Samples from both populations were classified into categories of similar biopsy depths based on biopsy depth quartiles. Median lead contents were statistically different between the Ribeirao Preto population (206 {mu}g/g, range: 5-1399 {mu}g/g) and the Bauru population (786 {mu}g/g, range: 320-4711 {mu}g/g) (p<0.001); however, biopsy depth did not differ between the Ribeirao Preto (3.9 {mu}m, Standard Deviation, SD=0.9) and Bauru (3.8 {mu}m, SD=0.9) populations (p=0.7940). Pearson's correlation coefficient for biopsy depths versus log{sub 10} lead values was -0.29 for Ribeirao Preto and -0.18 for Bauru. Lead contents were statistically different between the two populations for all quartiles of biopsy depth. These findings suggest that lead accumulated in the surface enamel of deciduous teeth is linked to the environment in which people reside, indicating that this tissue should be further explored as an accessible biomarker of lead exposure.« less

Cell protein cross-linking by erbstatin and related compounds | Center for Cancer Research

Cancer.gov

The scheme depicts a possible mechanism of cross-linking by erbstatin and related analogues. A mechanism of action is proposed which involves initial oxidation to reactive quinone intermediates that subsequently cross-link protein nucleophiles via multiple 1,4-Michael-type additions. Similar alkylation of protein by protein-tyrosine kinase inhibitors, such as herbimycin A, has

An Insoluble Titanium-Lead Anode for Sulfate Electrolytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferdman, Alla

2005-05-11

was no measurable anode weight loss during this time period. Quantitative chemical analysis of the anode surface showed that the lead content after testing remained at its initial level. No lead dissolution or transfer from the anode to the product occurred.A key benefit of the titanium-lead anode design is that cobalt additions to copper electrolyte should be eliminated. Cobalt is added to the electrolyte to help stabilize the lead oxide surface of conventional lead anodes. The presence of the titanium intimately mixed with the lead should eliminate the need for cobalt stabilization of the lead surface. The anode should last twice as long as the conventional lead anode. Energy savings should be achieved due to minimizing and stabilizing the anode-cathode distance in the electrowinning cells. The anode is easily substitutable into existing tankhouses without a rectifier change.The copper electrowinning test data indicate that the titanium-lead anode is a good candidate for further testing as a possible replacement for a conventional lead anode. A key consideration is the cost. Titanium costs have increased. One of the ways to get the anode cost down is manufacturing the anodes with fewer cylinders. Additional prototypes having different number of cylinders were constructed for a long-term commercial testing in a circuit without cobalt. The objective of the testing is to evaluate the need for cobalt, investigate the effect of decreasing the number of cylinders on the anode performance, and to optimize further the anode design in order to meet the operating requirements, minimize the voltage, maximize the life of the anode, and to balance this against a reasonable cost for the anode. It is anticipated that after testing of the additional prototypes, a whole cell commercial test will be conducted to complete evaluation of the titanium-lead anode costs/benefits.« less

Protein-Linked Glycan Degradation in Infants Fed Human Milk

PubMed Central

Dallas, David C.; Sela, David; Underwood, Mark A.; German, J. Bruce; Lebrilla, Carlito

2014-01-01

Many human milk proteins are glycosylated. Glycosylation is important in protecting bioactive proteins and peptide fragments from digestion. Protein-linked glycans have a variety of functions; however, there is a paucity of information on protein-linked glycan degradation in either the infant or the adult digestive system. Human digestive enzymes can break down dietary disaccharides and starches, but most of the digestive enzymes required for complex protein-linked glycan degradation are absent from both human digestive secretions and the external brush border membrane of the intestinal lining. Indeed, complex carbohydrates remain intact throughout their transit through the stomach and small intestine, and are undegraded by in vitro incubation with either adult pancreatic secretions or intact intestinal brush border membranes. Human gastrointestinal bacteria, however, produce a wide variety of glycosidases with regio- and anomeric specificities matching those of protein-linked glycan structures. These bacteria degrade a wide array of complex carbohydrates including various protein-linked glycans. That bacteria possess glycan degradation capabilities, whereas the human digestive system, perse, does not, suggests that most dietary protein-linked glycan breakdown will be of bacterial origin. In addition to providing a food source for specific bacteria in the colon, protein-linked glycans from human milk may act as decoys for pathogenic bacteria to prevent invasion and infection of the host. The composition of the intestinal microbiome may be particularly important in the most vulnerable humans-the elderly, the immunocompromised, and infants (particularly premature infants). PMID:24533224

Aggregate-level lead exposure, gun violence, homicide, and rape

PubMed Central

Nelson, Erik J.; Qian, Zhengmin; Vaughn, Michael G.; Wright, John P.; Beaver, Kevin M.; Barnes, J. C.; Petkovsek, Melissa; Lewis, Roger; Schootman, Mario; Rosenfeld, Richard

2017-01-01

Context An increasing body of research has linked the geographic distribution of lead with various indicators of criminal and antisocial behavior. Objective The current study, using data from an ongoing project related to lead exposure in St. Louis City, MO, analyzed the association between aggregate blood lead levels and specific indicators violent crime within the city. Design Ecological study. Setting St. Louis, Missouri. Exposure measure Blood lead levels. Main outcome measure Official reports of violent crimes were categorized as 1) crimes involving a firearm (yes/no), 2) assault crimes (with or without a firearm), 3) robbery crimes (with or without a firearm), 4) homicides and 5) rape. Results With the exception of rape, aggregate blood-lead levels were statistically significant predictors of violent crime at the census tract level. The risk ratios for each of the outcome measures were as follows: firearm crimes 1.03 (1.03–1.04), assault crimes 1.03 (1.02–1.03), robbery crimes 1.03 (1.02–1.04), homicide 1.03 (1.01, 1.04), and rape 1.01 (0.99–1.03). Conclusions Extending prior research in St. Louis, results suggest that aggregated lead exposure at the census tract level predicted crime outcomes, even after accounting for important sociological variables. Moving forward, a more developed understanding of aggregate level crime may necessitate a shift toward studying the synergy between sociological and biological risk factors such as lead exposure. PMID:29176826

To Cross-Link or Not to Cross-Link? Cross-Linking Associated Foreign Body Response of Collagen-Based Devices

PubMed Central

Delgado, Luis M.; Bayon, Yves; Pandit, Abhay

2015-01-01

Collagen-based devices, in various physical conformations, are extensively used for tissue engineering and regenerative medicine applications. Given that the natural cross-linking pathway of collagen does not occur in vitro, chemical, physical, and biological cross-linking methods have been assessed over the years to control mechanical stability, degradation rate, and immunogenicity of the device upon implantation. Although in vitro data demonstrate that mechanical properties and degradation rate can be accurately controlled as a function of the cross-linking method utilized, preclinical and clinical data indicate that cross-linking methods employed may have adverse effects on host response, especially when potent cross-linking methods are employed. Experimental data suggest that more suitable cross-linking methods should be developed to achieve a balance between stability and functional remodeling. PMID:25517923

Synthesis, Characterization, and Antibacterial Activity of Cross-Linked Chitosan-Glutaraldehyde

PubMed Central

Li, Bin; Shan, Chang-Lin; Zhou, Qing; Fang, Yuan; Wang, Yang-Li; Xu, Fei; Han, Li-Rong; Ibrahim, Muhammad; Guo, Long-Biao; Xie, Guan-Lin; Sun, Guo-Chang

2013-01-01

This present study deals with synthesis, characterization and antibacterial activity of cross-linked chitosan-glutaraldehyde. Results from this study indicated that cross-linked chitosan-glutaraldehyde markedly inhibited the growth of antibiotic-resistant Burkholderia cepacia complex regardless of bacterial species and incubation time while bacterial growth was unaffected by solid chitosan. Furthermore, high temperature treated cross-linked chitosan-glutaraldehyde showed strong antibacterial activity against the selected strain 0901 although the inhibitory effects varied with different temperatures. In addition, physical-chemical and structural characterization revealed that the cross-linking of chitosan with glutaraldehyde resulted in a rougher surface morphology, a characteristic Fourier transform infrared (FTIR) band at 1559 cm−1, a specific X-ray diffraction peak centered at 2θ = 15°, a lower contents of carbon, hydrogen and nitrogen, and a higher stability of glucose units compared to chitosan based on scanning electron microscopic observation, FTIR spectra, X-ray diffraction pattern, as well as elemental and thermo gravimetric analysis. Overall, this study indicated that cross-linked chitosan-glutaraldehyde is promising to be developed as a new antibacterial drug. PMID:23670533

A proposed model of psychodynamic psychotherapy linked to Erik Erikson's eight stages of psychosocial development.

PubMed

Knight, Zelda Gillian

2017-09-01

Just as Freud used stages of psychosexual development to ground his model of psychoanalysis, it is possible to do the same with Erik Erikson's stages of development with regards to a model of psychodynamic psychotherapy. This paper proposes an eight-stage model of psychodynamic psychotherapy linked to Erik Erikson's eight stages of psychosocial development. Various suggestions are offered. One such suggestion is that as each of Erikson's developmental stages is triggered by a crisis, in therapy it is triggered by the client's search. The resolution of the search often leads to the development of another search, which implies that the therapy process comprises a series of searches. This idea of a series of searches and resolutions leads to the understanding that identity is developmental and therapy is a space in which a new sense of identity may emerge. The notion of hope is linked to Erikson's stage of Basic Trust and the proposed model of therapy views hope and trust as essential for the therapy process. Two clinical vignettes are offered to illustrate these ideas. Psychotherapy can be approached as an eight-stage process and linked to Erikson's eight stages model of development. Psychotherapy may be viewed as a series of searches and thus as a developmental stage resolution process, which leads to the understanding that identity is ongoing throughout the life span. Copyright © 2017 John Wiley & Sons, Ltd.

What's the Link? New Organization To Promote Nationwide Environmental Health Tracking.

ERIC Educational Resources Information Center

O'Hara, Jim

2000-01-01

Reports that the Environmental Protection Agency (EPA) has been tracking the levels of lead, which is linked to increased behavioral disorders, retardation, and anemia in children, in the United States since the 1970s. Provides statistics on the current state of chronic diseases in the U.S. and asserts that there is a need for a nationwide heath…

Can Intensified Tuberculosis Case Finding Efforts at Nutrition Rehabilitation Centers Lead to Pediatric Case Detection in Bihar, India?

PubMed Central

Mishra, Bal Krishna; Moonan, Patrick K.; Nair, Sreenivas A.; Kumar, Ajay M. V.; Gandhi, Mohit P.; Mannan, Shamim

2016-01-01

Introduction Seven district-level Nutritional Rehabilitation Centres (NRCs) in Bihar, India provide clinical and nutritional care for children with severe acute malnutrition (SAM). Aim To assess whether intensified case finding (ICF) strategies at NRCs can lead to pediatric case detection among SAM children and link them to TB treatment under the Revised National Tuberculosis Control Programme (RNTCP). Materials and Methods A retrospective cohort study was conducted that included medical record reviews of SAM children registered for TB screening and RNTCP care during July–December 2012. Results Among 440 SAM children screened, 39 (8.8%) were diagnosed with TB. Among these, 34 (87%) initiated TB treatment and 18 (53%) were registered with the RNTCP. Of 16 children not registered under the RNTCP, nine (56%) weighed below six kilograms—the current weight requirement for receiving drugs under RNTCP. Conclusion ICF approaches are feasible at NRCs; however, screening for TB entails diagnostic challenges, especially among SAM children. However, only half of the children diagnosed with TB were treated by the RNTCP. More effort is needed to link this vulnerable population to TB services in addition to introducing child-friendly drug formulations for covering children weighing less than six kilograms. PMID:27066518

Lead

MedlinePlus

... Agendas, and Minutes New Blood Lead Level Information Funding Information Lead in Drinking Water Lead-based Water Lines Washington, D.C. Blood Lead Level Tests Effect of Previously Missing Blood Lead Level (BPb) Surveillance ...

Energy-effective Grinding of Inorganic Solids Using Organic Additives.

PubMed

Mishra, Ratan K; Weibel, Martin; Müller, Thomas; Heinz, Hendrik; Flatt, Robert J

2017-08-09

We present our research findings related to new formulations of the organic additives (grinding aids) needed for the efficient grinding of inorganic solids. Even though the size reduction phenomena of the inorganic solid particles in a ball mill is purely a physical process, the addition of grinding aids in milling media introduces a complex physicochemical process. In addition to further gain in productivity, the organic additive helps to reduce the energy needed for grinding, which in the case of cement clinker has major environmental implications worldwide. This is primarily due to the tremendous amounts of cement produced and almost 30% of the associated electrical energy is consumed for grinding. In this paper, we examine the question of how to optimize these grinding aids linking molecular insight into their working mechanisms, and also how to design chemical additives of improved performance for industrial comminution.

Linking communities to formal health care providers through village health teams in rural Uganda: lessons from linking social capital.

PubMed

Musinguzi, Laban Kashaija; Turinawe, Emmanueil Benon; Rwemisisi, Jude T; de Vries, Daniel H; Mafigiri, David K; Muhangi, Denis; de Groot, Marije; Katamba, Achilles; Pool, Robert

2017-01-11

Community-based programmes, particularly community health workers (CHWs), have been portrayed as a cost-effective alternative to the shortage of health workers in low-income countries. Usually, literature emphasises how easily CHWs link and connect communities to formal health care services. There is little evidence in Uganda to support or dispute such claims. Drawing from linking social capital framework, this paper examines the claim that village health teams (VHTs), as an example of CHWs, link and connect communities with formal health care services. Data were collected through ethnographic fieldwork undertaken as part of a larger research program in Luwero District, Uganda, between 2012 and 2014. The main methods of data collection were participant observation in events organised by VHTs. In addition, a total of 91 in-depth interviews and 42 focus group discussions (FGD) were conducted with adult community members as part of the larger project. After preliminary analysis of the data, we conducted an additional six in-depth interviews and three FGD with VHTs and four FGD with community members on the role of VHTs. Key informant interviews were conducted with local government staff, health workers, local leaders, and NGO staff with health programs in Luwero. Thematic analysis was used during data analysis. The ability of VHTs to link communities with formal health care was affected by the stakeholders' perception of their roles. Community members perceive VHTs as working for and under instructions of "others", which makes them powerless in the formal health care system. One of the challenges associated with VHTs' linking roles is support from the government and formal health care providers. Formal health care providers perceived VHTs as interested in special recognition for their services yet they are not "experts". For some health workers, the introduction of VHTs is seen as a ploy by the government to control people and hide its inability to provide health

Why might poor sleep quality lead to depression? A role for emotion regulation.

PubMed

O'Leary, Kimberly; Bylsma, Lauren M; Rottenberg, Jonathan

2017-12-01

Disordered sleep is strongly linked to future depression, but the reasons for this link are not well understood. This study tested one possibility - that poorer sleep impairs emotion regulation (ER), which over time leads to increased depressive symptoms. Our sample contained individuals with a wide range of depression symptoms (current depression, N = 54, remitted depression, N = 36, and healthy control, N = 53), who were followed clinically over six months and reassessed for changes in depressive symptom levels. As predicted, maladaptive ER mediated both cross-sectional and prospective relationships between poor sleep quality and depression symptoms. In contrast, an alternative mediator, physical activity levels, did not mediate the link between sleep quality and depression symptoms. Maladaptive ER may help explain why sleep difficulties contribute to depression symptoms; implications for interventions are discussed.

Childhood lead poisoning associated with traditional Chinese medicine: a case report and the subsequent lead source inquiry.

PubMed

Lin, Guo-zhen; Wu, Fei; Yan, Chong-huai; Li, Ke; Liu, Xiang-yi

2012-07-11

Traditional medicines or ethnic remedies, such as Ayurvedic drug of India, have been reported in numerous cases to be one of the main exposure risks for severe lead poisoning. We describe the poisoning of 2 young children from a Chinese family in Guangzhou as a result of the use of traditional Chinese medicine instead of baby powder. A 3-y-old boy with blood lead levels (BLLs) of 303 μg/l and his 6-month-old sister with BLLs of 385 μg/l were hospitalized. Laboratory tests showed that the powder, which was purchased in Ganzhou during a family visit, contained a lead concentration of 214,000 mg/kg. A subsequent inspection revealed that the lead contamination was in fact achieved by the addition of Hongdan to talcum. In Ganzhou, it was a popular practice for young children to apply this leaded powder on their skins in order to treat and prevent dermatitis. We sampled 16 Hongdans and observed an average lead content of 817,000 mg/kg that was comprised mainly of lead tetraoxide (Pb(3)O(4)). Lead tetraoxide is also an accessible raw material for paint and battery industries. The health authority of China should reevaluate the safety of such traditional remedy and weigh its toxicity versus its potential benefits. Clinicians should be aware of this leaded powder when treating a lead poisoning case that shows no explainable cause. Copyright © 2012 Elsevier B.V. All rights reserved.

Mechanical Strength Improvements of Carbon Nanotube Threads through Epoxy Cross-Linking

PubMed Central

Yu, Qingyue; Alvarez, Noe T.; Miller, Peter; Malik, Rachit; Haase, Mark R.; Schulz, Mark; Shanov, Vesselin; Zhu, Xinbao

2016-01-01

Individual Carbon Nanotubes (CNTs) have a great mechanical strength that needs to be transferred into macroscopic fiber assemblies. One approach to improve the mechanical strength of the CNT assemblies is by creating covalent bonding among their individual CNT building blocks. Chemical cross-linking of multiwall CNTs (MWCNTs) within the fiber has significantly improved the strength of MWCNT thread. Results reported in this work show that the cross-linked thread had a tensile strength six times greater than the strength of its control counterpart, a pristine MWCNT thread (1192 MPa and 194 MPa, respectively). Additionally, electrical conductivity changes were observed, revealing 2123.40 S·cm−1 for cross-linked thread, and 3984.26 S·cm−1 for pristine CNT thread. Characterization suggests that the obtained high tensile strength is due to the cross-linking reaction of amine groups from ethylenediamine plasma-functionalized CNT with the epoxy groups of the cross-linking agent, 4,4-methylenebis(N,N-diglycidylaniline). PMID:28787868

Digital optical feeder links system for broadband geostationary satellite

NASA Astrophysics Data System (ADS)

Poulenard, Sylvain; Mège, Alexandre; Fuchs, Christian; Perlot, Nicolas; Riedi, Jerome; Perdigues, Josep

2017-02-01

An optical link based on a multiplex of wavelengths at 1.55μm is foreseen to be a valuable solution for the feeder link of the next generation of high-throughput geostationary satellite. The main satellite operator specifications for such link are an availability of 99.9% over the year, a capacity around 500Gbit/s and to be bent-pipe. Optical ground station networks connected to Terabit/s terrestrial fibers are proposed. The availability of the optical feeder link is simulated over 5 years based on a state-of-the-art cloud mask data bank and an atmospheric turbulence strength model. Yearly and seasonal optical feeder link availabilities are derived and discussed. On-ground and on-board terminals are designed to be compliant with 10Gbit/s per optical channel data rate taking into account adaptive optic systems to mitigate the impact of atmospheric turbulences on single-mode optical fiber receivers. The forward and return transmission chains, concept and implementation, are described. These are based on a digital transparent on-off keying optical link with digitalization of the DVB-S2 and DVB-RCS signals prior to the transmission, and a forward error correcting code. In addition, the satellite architecture is described taking into account optical and radiofrequency payloads as well as their interfaces.

Tsunami Focusing and Leading Amplitude

NASA Astrophysics Data System (ADS)

Kanoglu, U.

2016-12-01

Tsunamis transform substantially through spatial and temporal spreading from their source region. This substantial spreading might result unique maximum tsunami wave heights which might be attributed to the source configuration, directivity, the waveguide structures of mid-ocean ridges and continental shelves, focusing and defocusing through submarine seamounts, random focusing due to small changes in bathymetry, dispersion, and, most likely, combination of some of these effects. In terms of the maximum tsunami wave height, after Okal and Synolakis (2016 Geophys. J. Int. 204, 719-735), it is clear that dispersion would be one of the reasons to drive the leading wave amplitude in a tsunami wave train. Okal and Synolakis (2016), referring to this phenomenon as sequencing -later waves in the train becoming higher than the leading one, considered Hammack's (1972, Ph.D. Dissertation, Calif. Inst. Tech., 261 pp) formalism, in addition to LeMéhauté and Wang's (1995 Water waves generated by underwater explosion, World Scientific, 367 pp), to evaluate linear dispersive tsunami propagation from a circular plug uplifted on an ocean of constant depth. They identified transition distance, as the second wave being larger, performing parametric study for the radius of the plug and the depth of the ocean. Here, we extend Okal and Synolakis' (2016) analysis to an initial wave field with a finite crest length and, in addition, to a most common tsunami initial wave form of N-wave (Tadepalli and Synolakis, 1994 Proc. R. Soc. A: Math. Phys. Eng. Sci. 445, 99-112). First, we investigate the focusing feature in the leading-depression side, which enhance tsunami wave height as presented by Kanoglu et al. (2013 Proc. R. Soc. A: Math. Phys. Eng. Sci. 469, 20130015). We then discuss the results in terms of leading wave amplitude presenting a parametric study and identify a simple relation for the transition distance. The solution presented here could be used to better analyze dispersive

Marijuana Use at School and Achievement-Linked Behaviors

ERIC Educational Resources Information Center

Finn, Kristin V.

2012-01-01

Marijuana remains one of the most frequently used drugs among adolescents and usage has increased in recent years. In addition to general use, many high school students use marijuana during the school day. The present study focused on achievement-linked correlates of in-school marijuana use by comparing non-users, general users, and school users…

New Information on Lead in Dirt and Dust as Related to the Childhood Lead Problem

PubMed Central

Haar, Gary Ter; Aronow, Regine

1974-01-01

It has been known for many years that the eating of leaded paint is the prime cause of lead poisoning and elevated blood leads of children living in deteriorated housing. Recently, there has been speculation that children may eat dirt and dust contaminated with lead exhausted from cars and that this amount of ingested lead is sufficient to contribute significantly to the childhood lead problem. This paper reports on a twopart study conducted to evaluate the validity of the dirt-and-dust hypotheses. The first part of the study was made to determine the source of lead in dirt to which children are normally exposed. Dirt samples were taken in old urban areas around 18 painted frame houses and 18 houses of brick construction. Samples also were taken around seven old frame farmhouses remote from traffic. Based on the fact that lead concentrations in the dirt were similar in city and rural yards at corresponding distances from the houses, it is clear that nearly all of the lead in dirt around these houses is due to paint from the houses. Lead antiknock additives are therefore not a significant contributor to the lead content of dirt around houses where children usually play. The second part of the study used a naturally occurring radioactive tracer 210Pb to determine the relative amounts of dust and other lead-containing materials (e.g., paint) eaten by young children. This tracer is present in very low concentrations in paint and in significantly higher concentrations in fallout dust. Stable lead and 210Pb were analyzed in fecal material from eight children suspected of having elevated body burdens of lead and ten children living in good housing where lead poisoning is not a problem. The normal children averaged 4 μg Pb/g dry feces, with a range of 2 to 7. Of the eight children suspected of having elevated lead body burdens, two had fecal lead values within the normal range. However, the remaining six were 4 to 400 times as high. Despite these differences in fecal lead

On-Demand Dissolution of Chemically Cross-Linked Hydrogels.

PubMed

Konieczynska, Marlena D; Grinstaff, Mark W

2017-02-21

The formation and subsequent on-demand dissolution of chemically cross-linked hydrogels is of keen interest to chemists, engineers, and clinicians. In this Account, we summarize our recent advances in the area of dissolvable chemically cross-linked hydrogels and provide a comparative discussion of other recent hydrogel systems. Using biocompatible macromonomers, we developed a library of cross-linked dendritic hydrogels that possess favorable properties, including biocompatibility, tissue adhesion, and swelling. Additionally, these hydrogels possess the unique ability to dissolve on-demand via application of a biocompatible aqueous solution. Each of the three hydrogel systems described employs a thiol-thioester exchange reaction as the mechanism of dissolution. These new materials successfully decrease bleeding in in vivo models of hepatic and aortic hemorrhage and dissolve on-demand, providing easy removal. In addition, we evaluated these hydrogels as dressings for second-degree burn wounds and performed proof-of-concept in vivo studies. These hydrogel wound dressings provide a means of repeatedly changing the dressing in a minimally invasive and atraumatic manner while also serving as a protective barrier against bacterial infection. Finally, we highlight the seminal work of other researchers in the field of dissolvable chemically cross-linked hydrogels using thiol-disulfide exchange, retro-Michael-type, and retro-Diels-Alder reactions. These chemistries provide a versatile synthetic toolbox to dissolve hydrogels in a controlled manner on time scales from minutes to weeks. Continued investigation of these dissolution approaches as well as the development of new chemical reactions will open doors to other avenues of on-demand dissolution and expand the application space for these materials. In summary, the management and closure of wounds after traumatic injury or surgical intervention are of significant clinical importance. Stimuli-responsive hydrogels that

MAROON BELLS-SNOWMASS WILDERNESS AND ADDITIONS, COLORADO.

USGS Publications Warehouse

Freeman, Val L.; Weisner, Robert C.

1984-01-01

The Maroon Bells-Snowmass Wilderness and Additions, located in western Colorado, was examined for mineral potential. Evidence of mineralization is widespread and numerous areas have either probable or substantiated mineral-resource potential for one or more of the following metals: gold, silver, lead, zinc, copper, and molybdenum. In addition, part of the wilderness has substantiated coal resource potential. There is little promise for the occurrence of oil and gas or geothermal resources.

Vitamin C modulates lead excretion in rats.

PubMed

Lihm, Hoseob; Kim, Hyun; Chang, Heekyung; Yoon, Myunghee; Lee, Kayoung; Choi, Jongsoon

2013-12-01

Lead, one of the most toxic heavy metals, takes longer time to be excreted from the body than other heavy metals. The purpose of this study is, by measuring lead excretion via urine and feces, to find out the effect of vitamin C in lead chelation. Thirty-six rats were randomly assorted into four groups. All 33 rats except for the control group were administered with lead, before orally administered with different doses of vitamin C per kilogram of body weight. The lead excretion levels in urine and feces as well as the survival rate were then measured for each group. The rats with lead administrations (10/13, 76.9%) with lead administrations only, 10/11 rats (90.9%) with lead administrations and low dose of vitamin C, 9/9 rats (100%) with lead administrations and high dose of vitamin C survived. Among the 29 surviving rats, low vitamin C intake group exhibited higher urinary excretion than the lead only group. The urinary excretion level in high dose vitamin C intakegroup was significantly higher than the lead only group. In addition, fecal lead excretion seemed to be increased in the high dose vitamin C intake group, compared to the group with lead administrations only with statistical significance. Through animal experiment, it was found out that administrating high dose of vitamin C accelerated the excretion of lead in body compared to low dose of vitamin C.

Curcumin, inflammation, and chronic diseases: how are they linked?

PubMed

He, Yan; Yue, Yuan; Zheng, Xi; Zhang, Kun; Chen, Shaohua; Du, Zhiyun

2015-05-20

It is extensively verified that continued oxidative stress and oxidative damage may lead to chronic inflammation, which in turn can mediate most chronic diseases including cancer, diabetes, cardiovascular, neurological, inflammatory bowel disease and pulmonary diseases. Curcumin, a yellow coloring agent extracted from turmeric, shows strong anti-oxidative and anti-inflammatory activities when used as a remedy for the prevention and treatment of chronic diseases. How oxidative stress activates inflammatory pathways leading to the progression of chronic diseases is the focus of this review. Thus, research to date suggests that chronic inflammation, oxidative stress, and most chronic diseases are closely linked, and the antioxidant properties of curcumin can play a key role in the prevention and treatment of chronic inflammation diseases.

Inflammation and lithium: clues to mechanisms contributing to suicide-linked traits

PubMed Central

Beurel, E; Jope, R S

2014-01-01

Suicide is one of the leading causes of death in the United States, yet it remains difficult to understand the mechanistic provocations and to intervene therapeutically. Stress is recognized as a frequent precursor to suicide. Psychological stress is well established to cause activation of the inflammatory response, including causing neuroinflammation, an increase of inflammatory molecules in the central nervous system (CNS). Neuroinflammation is increasingly recognized as affecting many aspects of CNS functions and behaviors. In particular, much evidence demonstrates that inflammatory markers are elevated in traits that have been linked to suicidal behavior, including aggression, impulsivity and depression. Lithium is recognized as significantly reducing suicidal behavior, is anti-inflammatory and diminishes aggression, impulsivity and depression traits, each of which is associated with elevated inflammation. The anti-inflammatory effects of lithium result from its inhibition of glycogen synthase kinase-3 (GSK3). GSK3 has been demonstrated to strongly promote inflammation, aggressive behavior in rodents and depression-like behaviors in rodents, whereas regulation of impulsivity by GSK3 has not yet been investigated. Altogether, evidence is building supporting the hypothesis that stress activates GSK3, which in turn promotes inflammation, and that inflammation is linked to behaviors associated with suicide, including particularly aggression, impulsivity and depression. Further investigation of these links may provide a clearer understanding of the causes of suicidal behavior and provide leads for the development of effective preventative interventions, which may include inhibitors of GSK3. PMID:25514751

Inflammation and lithium: clues to mechanisms contributing to suicide-linked traits.

PubMed

Beurel, E; Jope, R S

2014-12-16

Suicide is one of the leading causes of death in the United States, yet it remains difficult to understand the mechanistic provocations and to intervene therapeutically. Stress is recognized as a frequent precursor to suicide. Psychological stress is well established to cause activation of the inflammatory response, including causing neuroinflammation, an increase of inflammatory molecules in the central nervous system (CNS). Neuroinflammation is increasingly recognized as affecting many aspects of CNS functions and behaviors. In particular, much evidence demonstrates that inflammatory markers are elevated in traits that have been linked to suicidal behavior, including aggression, impulsivity and depression. Lithium is recognized as significantly reducing suicidal behavior, is anti-inflammatory and diminishes aggression, impulsivity and depression traits, each of which is associated with elevated inflammation. The anti-inflammatory effects of lithium result from its inhibition of glycogen synthase kinase-3 (GSK3). GSK3 has been demonstrated to strongly promote inflammation, aggressive behavior in rodents and depression-like behaviors in rodents, whereas regulation of impulsivity by GSK3 has not yet been investigated. Altogether, evidence is building supporting the hypothesis that stress activates GSK3, which in turn promotes inflammation, and that inflammation is linked to behaviors associated with suicide, including particularly aggression, impulsivity and depression. Further investigation of these links may provide a clearer understanding of the causes of suicidal behavior and provide leads for the development of effective preventative interventions, which may include inhibitors of GSK3.

The CCSDS Next Generation Space Data Link Protocol (NGSLP)

NASA Technical Reports Server (NTRS)

Kazz, Greg J.; Greenberg, Edward

2014-01-01

next leap in performance for space link communications. Field Programmable Gate Arrays (FPGAs) provide the capability to incorporate high performance forward error correcting codes implemented within software transponders providing improved performance in data transfer, ranging, link security, and time correlation. Given these synergistic technological breakthroughs, the time has come to take advantage of them in applying them to both on going (e.g., command, telemetry) and emerging (e.g., space link security, optical communication) space link applications. However one of the constraining factors within the Data Link Layer in realizing these performance gains is the lack of a generic transfer frame format and common supporting services amongst the existing CCSDS link layer protocols. Currently each of the four CCSDS link layer protocols (TM, TC, AOS, and Proximity-1) have unique formats and services which prohibits their reuse across the totality of all space link applications of CCSDS member space agencies. For example, Mars missions. These missions implement their proximity data link layer using the Proximity-1 frame format and the services it supports but is still required to support the direct from Earth (TC) protocols and the Direct To Earth (AOS/TM) protocols. The prime purpose of this paper, is to describe a new general purpose CCSDS Data Link layer protocol, the NGSLP that will provide the required services along with a common transfer frame format for all the CCSDS space links (ground to/from space and space to space links) targeted for emerging missions after a CCSDS agency-wide coordinated date. This paper will also describe related options that can be included for the Coding and Synchronization sub-layer of the Data Link layer to extend the capacities of the link and additionally provide an independence of the transfer frame sub-layer from the coding sublayer. This feature will provide missions the option of running either the currently performed

Extended model of restricted beam for FSO links

NASA Astrophysics Data System (ADS)

Poliak, Juraj; Wilfert, Otakar

2012-10-01

Modern wireless optical communication systems in many aspects overcome wire or radio communications. Their advantages are license-free operation and broad bandwidth that they offer. The medium in free-space optical (FSO) links is the atmosphere. Operation of outdoor FSO links struggles with many atmospheric phenomena that deteriorate phase and amplitude of the transmitted optical beam. This beam originates in the transmitter and is affected by its individual parts, especially by the lens socket and the transmitter aperture, where attenuation and diffraction effects take place. Both of these phenomena unfavourable influence the beam and cause degradation of link availability, or its total malfunction. Therefore, both of these phenomena should be modelled and simulated, so that one can judge the link function prior to the realization of the system. Not only the link availability and reliability are concerned, but also economic aspects. In addition, the transmitted beam is not, generally speaking, circularly symmetrical, what makes the link simulation more difficult. In a comprehensive model, it is necessary to take into account the ellipticity of the beam that is restricted by circularly symmetrical aperture where then the attenuation and diffraction occur. General model is too computationally extensive; therefore simplification of the calculations by means of analytical and numerical approaches will be discussed. Presented model is not only simulated using computer, but also experimentally proven. One can then deduce the ability of the model to describe the reality and to estimate how far can one go with approximations, i.e. limitations of the model are discussed.

Lead sulphide: Low cost, abundant thermoelectrics

NASA Astrophysics Data System (ADS)

Ahmad, Sajid; Singh, Ajay; Bhattacharya, Shovit; Basu, Ranita; Bhatt, Ranu; Bohra, Anil; Muthe, K. P.; Gadkari, S. C.

2018-04-01

Lead and sulphur are the most abundant and low cost materials on the earth's crust, lead chalcogenide (S, Se and Te) materials have got best applications in thermoelectric power generations. Among the chalcogenides, selenium and tellurium are costlier and are more toxic material than sulphur. [1][2] Decreasing the thermal conductivity has been proven to be the easiest approach to improve the thermoelectric performance of a material. In the present work, the lead sulphide (PbS) and SrxPb(1-x)S composite materials were synthesized and investigated. Addition of 0.4 and 0.8 moles of Sr atoms into the PbS lattice has appreciably reduced the thermal conductivity from 2.2 W/mK to 0.43 W/mK for Sr0.4Pb0.6S composition. Temperature (T) dependence of thermoelectric (TE) properties PbS and and SrxPb(1-x)S nanocomposite material has been studied with in the temperature range of 300 K to 700 K. It is observed that there is reduction in the thermal conductivity of PbS alloy on addition of Sr that is mainly attributed to the scattering centres of Sr in the PbS matrix also the presence of the Sr also plays a role in the refinement of the PbS matrix.

Chronic lead poisoning in horses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dollahite, J.W.; Younger, R.L.; Crookshank, H.R.

1978-06-01

Lead Acetate was fed to 4 groups of 2 horses each to study chronic lead intoxication. A 5th group of 3 horses was maintained as controls. The lead was fed in capsules, with the minimum dosage of 6.25 mg/kg/day of lead as lead acetate (group I). The dose was increased from group I through group IV in an approximate geometric series, with each group being given about 125% of the dose given the previous group. These doses were given for 105 days, a period designated as phase 1. Since clinical signs were not observed after 105 days, the doses weremore » increased and fed for an additional 190 days (days 106 to 295). This period was designated phase 2. The smallest daily dose in phase 2 was set at about 125% of the largest daily dose in phase 1. The doses in each group was increased by about 125% of that of the previous group, as was done in phase 1. Seven horses died or were euthanatized after 18 to 190 days of phase 2 (123 to 295 days after the 1st dose). One horse in group I did not develop any clinical signs of intoxication. Dose-related responses were unnoticed with doses larger than 15.3 mg/kg/day. All horses given lead had increased blood lead and serum iron concentrations. During phase 2, the hematocrit and hemoglobin contents were depressed. The lead concentration in kidney, liver, spleen, pancreas, brain, bone, and heart was increased in the treated horses. The dose level required to produce lead intoxication was greater than that reported for cattle and that estimated in epizootiologic studies of horses.« less

NATURAL ARSENIC CONTAMINATION OF HOLOCENE ALLUVIAL AQUIFERS BY LINKED TECTONIC, WEATHERING, AND MICROBIAL PROCESSES

EPA Science Inventory

Linked tectonic, geochemical, and biologic processes lead to natural arsenic contamination of groundwater in Holocene alluvial aquifers, which are the main threat to human health around the world. These groundwaters are commonly found a long distance from their ultimate source of...

78 FR 62946 - Additional Designations, Foreign Narcotics Kingpin Designation Act

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-22

... significant foreign narcotics traffickers as identified by the President. In addition, the Secretary of the...; R.F.C. PAPA751109870 (Mexico); C.U.R.P. PAPA751109HNEDSL04 (Mexico) (individual) [SDNTK] (Linked To... No. 279, Supermanzana 50, Manzana 14, Lote 17, Residencial San Angel, Cancun, Quintana Roo, Mexico...

Leading-edge singularities in thin-airfoil theory

NASA Technical Reports Server (NTRS)

Jones, R. T.

1976-01-01

If the thin airfoil theory is applied to an airfoil having a rounded leading edge, a certain error will arise in the determination of the pressure distribution around the nose. It is shown that the evaluation of the drag of such a blunt nosed airfoil by the thin airfoil theory requires the addition of a leading edge force, analogous to the leading edge thrust of the lifting airfoil. The method of calculation is illustrated by application to: (1) The Joukowski airfoil in subsonic flow; and (2) the thin elliptic cone in supersonic flow. A general formula for the edge force is provided which is applicable to a variety of wing forms.

Chemical thermodynamic data. 1. The concept of links to the chemical elements and the historical development of key thermodynamic data

NASA Astrophysics Data System (ADS)

Wolery, Thomas J.; Jové Colón, Carlos F.

2017-09-01

Chemical thermodynamic data remain a keystone for geochemical modeling and reactive transport simulation as applied to an increasing number of applications in the earth sciences, as well as applications in other areas including metallurgy, material science, and industrial process design. The last century has seen the development of a large body of thermodynamic data and a number of major compilations. The past several decades have seen the development of thermodynamic databases in digital form designed to support computer calculations. However, problems with thermodynamic data appear to be persistent. One problem pertains to the use of inconsistent primary key reference data. Such data pertain to elemental reference forms and key, stoichiometrically simple chemical species including metal oxides, CO2, water, and aqueous species such as Na+ and Cl-. A consistent set of primary key data (standard Gibbs energies, standard enthalpies, and standard entropies for key chemical species) for 298.15 K and 1 bar pressure is essential. Thermochemical convention is to define the standard Gibbs energy and the standard enthalpy of an individual chemical species in terms of formation from reference forms of the constituent chemical elements. We propose a formal concept of "links" to the elemental reference forms. This concept involves a documented understanding of all reactions and calculations leading to values for a formation property (standard Gibbs energy or enthalpy). A valid link consists of two parts: (a) the path of reactions and corrections and (b) the associated data, which are key data. Such a link differs from a bare "key" or "reference" datum in that it requires additional information. Some or all of its associated data may also be key data. In evaluating a reported thermodynamic datum, one should identify the links to the chemical elements, a process which can be time-consuming and which may lead to a dead end (an incomplete link). The use of two or more inconsistent

Integrative modelling reveals mechanisms linking productivity and plant species richness.

PubMed

Grace, James B; Anderson, T Michael; Seabloom, Eric W; Borer, Elizabeth T; Adler, Peter B; Harpole, W Stanley; Hautier, Yann; Hillebrand, Helmut; Lind, Eric M; Pärtel, Meelis; Bakker, Jonathan D; Buckley, Yvonne M; Crawley, Michael J; Damschen, Ellen I; Davies, Kendi F; Fay, Philip A; Firn, Jennifer; Gruner, Daniel S; Hector, Andy; Knops, Johannes M H; MacDougall, Andrew S; Melbourne, Brett A; Morgan, John W; Orrock, John L; Prober, Suzanne M; Smith, Melinda D

2016-01-21

How ecosystem productivity and species richness are interrelated is one of the most debated subjects in the history of ecology. Decades of intensive study have yet to discern the actual mechanisms behind observed global patterns. Here, by integrating the predictions from multiple theories into a single model and using data from 1,126 grassland plots spanning five continents, we detect the clear signals of numerous underlying mechanisms linking productivity and richness. We find that an integrative model has substantially higher explanatory power than traditional bivariate analyses. In addition, the specific results unveil several surprising findings that conflict with classical models. These include the isolation of a strong and consistent enhancement of productivity by richness, an effect in striking contrast with superficial data patterns. Also revealed is a consistent importance of competition across the full range of productivity values, in direct conflict with some (but not all) proposed models. The promotion of local richness by macroecological gradients in climatic favourability, generally seen as a competing hypothesis, is also found to be important in our analysis. The results demonstrate that an integrative modelling approach leads to a major advance in our ability to discern the underlying processes operating in ecological systems.

Optical space-to-ground link availability assessment and diversity requirements

NASA Technical Reports Server (NTRS)

Chapman, William; Fitzmaurice, Michael

1991-01-01

The application of optical space-to-ground links (SGLs) for high speed data distribution from geosynchronous and low earth orbiting satellites (e.g., sensor data from the planned Earth Observing System), for lunar and Mars links, and for links from interplanetary probes has been a topic of considerable recent interest. These optical SGLs could conceivably represent the system's operational baseline, or could represent backup links in the event of a GEO relay terminal failure. In this paper the availability of optical SGLs for various system/orbit configurations is considered. Single CONUS sites are assessed for their probability of cloud free line of sight (PCFLOS), and cloud free field of view (PCFFOV). PCFLOS represents an availability metric for geosynchronous platforms, while PCFFOV is a relevant performance metric for non-geostationary platforms (e.g., low earth orbiting satellites). Additionally, the availability of multiple ground terminals utilized in a diversity configuration is considered. Availability statistics vs. the number of diversity sites are derived from climatological data bases for CONUS sites.

Evaluation of a Pilot Surveillance System: Health and Environment Linked for Information Exchange in Atlanta (HELIX-Atlanta)

NASA Technical Reports Server (NTRS)

Meyer, P.; Shire, J.; Qualters, Judy; Daley, Randolph; Fiero, Leslie Todorov; Autry, Andy; Avchen, Rachel; Stock, Allison; Correa, Adolofo; Siffel, Csaba;

[Local anesthesia in dentistry. Additional techniques].

PubMed

Makkes, P C; Bouvy-Berends, E C; Rupreht, J

1996-05-01

Patients with insufficient coping abilities can yet be dentally treated by practising several additional techniques. Behaviour management should always be the starting point of all dental treatment strategies. In the end the administration of well selected drugs should lead, via anxiolysis, sedation or general anaesthesia, to a painfree and optimal treatable patient.

Enzyme-linked immunosorbent assay detection and bioactivity of Cry1Ab protein fragments

USDA-ARS?s Scientific Manuscript database

Enzyme-linked immunosorbent assay (ELISA) has emerged as the preferred detection method for Cry proteins in environmental matrices. Concerns exist that ELISAs are capable of detecting fragments of Cry proteins, which may lead to an over-estimation of the concentration of these proteins in the enviro...

Ubiquitousness of link-density and link-pattern communities in real-world networks

NASA Astrophysics Data System (ADS)

Šubelj, L.; Bajec, M.

2012-01-01

Community structure appears to be an intrinsic property of many complex real-world networks. However, recent work shows that real-world networks reveal even more sophisticated modules than classical cohesive (link-density) communities. In particular, networks can also be naturally partitioned according to similar patterns of connectedness among the nodes, revealing link-pattern communities. We here propose a propagation based algorithm that can extract both link-density and link-pattern communities, without any prior knowledge of the true structure. The algorithm was first validated on different classes of synthetic benchmark networks with community structure, and also on random networks. We have further applied the algorithm to different social, information, technological and biological networks, where it indeed reveals meaningful (composites of) link-density and link-pattern communities. The results thus seem to imply that, similarly as link-density counterparts, link-pattern communities appear ubiquitous in nature and design.

The effect of airborne lead particle size on worker blood-lead levels: an empirical study of battery workers.

PubMed

Hodgkins, D G; Robins, T G; Hinkamp, D L; Schork, M A; Levine, S P; Krebs, W H

1991-12-01

Theoretical models and experimental data suggest that the particle size distribution of lead aerosols should affect the lead dose absorbed by exposed workers. In the present study, 44 workers in five major operations in a high-volume, lead-acid battery plant were studied for the influence of lead aerosol size on lead-in-blood (PbB) levels. A multiple linear regression analysis based on particle size assumptions made in the model used by the Occupational Safety and Health Administration to help select the permissible exposure level (PEL) for lead showed no improvement in prediction of PbB over that already present without any consideration of particle size. The use of the American Conference of Governmental Industrial Hygienists (ACGIH) regional size-selective criteria also failed to improve the prediction of PbB. However, when deposition models developed by Heyder et al were used in which the lead aerosol was separated into alveolar and extra-alveolar fractions, corresponding to what is considered respirable and ingestible lead, the coefficient of determination (R2) associated with the fractionated lead particulate increased approximately 25% over that attributable to only the total lead concentration. In addition, the deposition model, which closely matched the ACGIH reference worker criteria, resulted in ratios of the coefficients for the respirable to ingestible lead contributions to PbB that appeared to agree with experimental data, suggesting approximately a 10 to 1 ratio in absorption efficiency of the lung versus the gastrointestinal tract.

Introduction to lead salt infrared detectors

NASA Astrophysics Data System (ADS)

Kondas, David A.

1993-02-01

This technical report establishes the background necessary to understand how lead sulfide (PbS) and lead selenide (PbSe) infrared detectors operate. Both detectors, which are members of the lead salt family of infrared detectors, use the photoconductive effect to detect energy residing within the infrared region of the electromagnetic spectrum. PbS detectors are useful for detecting energies in the 1 to 3 micrometer region, while PbSe detectors can detect energies in the 1 to 7 micrometer region. They are essentially polycrystalline thin films which are fabricated by chemical deposition techniques in either single element or multi-element array configurations. The significance of the electronic structure of these crystalline films and the effects of temperature on their operation and performance are discussed. The history of the development of lead salt detectors from the early years before World War I to the more recent developments is detailed. In addition, an overview of a typical infrared system is also presented.

X-linked Alport syndrome caused by splicing mutations in COL4A5.

PubMed

Nozu, Kandai; Vorechovsky, Igor; Kaito, Hiroshi; Fu, Xue Jun; Nakanishi, Koichi; Hashimura, Yuya; Hashimoto, Fusako; Kamei, Koichi; Ito, Shuichi; Kaku, Yoshitsugu; Imasawa, Toshiyuki; Ushijima, Katsumi; Shimizu, Junya; Makita, Yoshio; Konomoto, Takao; Yoshikawa, Norishige; Iijima, Kazumoto

2014-11-07

X-linked Alport syndrome is caused by mutations in the COL4A5 gene. Although many COL4A5 mutations have been detected, the mutation detection rate has been unsatisfactory. Some men with X-linked Alport syndrome show a relatively mild phenotype, but molecular basis investigations have rarely been conducted to clarify the underlying mechanism. In total, 152 patients with X-linked Alport syndrome who were suspected of having Alport syndrome through clinical and pathologic investigations and referred to the hospital for mutational analysis between January of 2006 and January of 2013 were genetically diagnosed. Among those patients, 22 patients had suspected splice site mutations. Transcripts are routinely examined when suspected splice site mutations for abnormal transcripts are detected; 11 of them showed expected exon skipping, but others showed aberrant splicing patterns. The mutation detection strategy had two steps: (1) genomic DNA analysis using PCR and direct sequencing and (2) mRNA analysis using RT-PCR to detect RNA processing abnormalities. Six splicing consensus site mutations resulting in aberrant splicing patterns, one exonic mutation leading to exon skipping, and four deep intronic mutations producing cryptic splice site activation were identified. Interestingly, one case produced a cryptic splice site with a single nucleotide substitution in the deep intron that led to intronic exonization containing a stop codon; however, the patient showed a clearly milder phenotype for X-linked Alport syndrome in men with a truncating mutation. mRNA extracted from the kidney showed both normal and abnormal transcripts, with the normal transcript resulting in the milder phenotype. This novel mechanism leads to mild clinical characteristics. This report highlights the importance of analyzing transcripts to enhance the mutation detection rate and provides insight into genotype-phenotype correlations. This approach can clarify the cause of atypically mild phenotypes in X-linked

Convergence of Human Genetics and Animal Studies: Gene Therapy for X-Linked Retinoschisis

PubMed Central

Bush, Ronald A.; Wei, Lisa L.; Sieving, Paul A.

2015-01-01

Retinoschisis is an X-linked recessive genetic disease that leads to vision loss in males. X-linked retinoschisis (XLRS) typically affects young males; however, progressive vision loss continues throughout life. Although discovered in 1898 by Haas in two brothers, the underlying biology leading to blindness has become apparent only in the last 15 years with the advancement of human genetic analyses, generation of XLRS animal models, and the development of ocular monitoring methods such as the electroretinogram and optical coherence tomography. It is now recognized that retinoschisis results from cyst formations within the retinal layers that interrupt normal visual neurosignaling and compromise structural integrity. Mutations in the human retinoschisin gene have been correlated with disease severity of the human XLRS phenotype. Introduction of a normal human retinoschisin cDNA into retinoschisin knockout mice restores retinal structure and improves neural function, providing proof-of-concept that gene replacement therapy is a plausible treatment for XLRS. PMID:26101206

The effect of a lignosulphate type additive on the lead—acid battery positive plate reactions

NASA Astrophysics Data System (ADS)

Ovuru, S. E.; Harrison, J. A.

The electrochemical formation of lead dioxide has been investigated at a lead electrode in a 5 M sulphuric acid solution, and in the presence of phosphoric acid and lignosulphate-type additive. The formation of lead dioxide from lead sulphate, and the reverse reaction, have been investigated by the linear potential sweep method, by an impedance method in which the impedance was measured at the end of each pulse during a potential pulse train, and by a charging curve method in which the current and charge was measured during a similar potential pulse train. The charge measurements prove that the main effect of the additive is to decrease the accompanying oxygen evolution reaction. The impedance measurements, however, show that the additive has a small but significant effect on the structure of the solid lead sulphate and lead dioxide layers.

Effects of adaptive dynamical linking in networked games

NASA Astrophysics Data System (ADS)

Yang, Zhihu; Li, Zhi; Wu, Te; Wang, Long

2013-10-01

The role of dynamical topologies in the evolution of cooperation has received considerable attention, as some studies have demonstrated that dynamical networks are much better than static networks in terms of boosting cooperation. Here we study a dynamical model of evolution of cooperation on stochastic dynamical networks in which there are no permanent partners to each agent. Whenever a new link is created, its duration is randomly assigned without any bias or preference. We allow the agent to adaptively adjust the duration of each link during the evolution in accordance with the feedback from game interactions. By Monte Carlo simulations, we find that cooperation can be remarkably promoted by this adaptive dynamical linking mechanism both for the game of pairwise interactions, such as the Prisoner's Dilemma game (PDG), and for the game of group interactions, illustrated by the public goods game (PGG). And the faster the adjusting rate, the more successful the evolution of cooperation. We also show that in this context weak selection favors cooperation much more than strong selection does. What is particularly meaningful is that the prosperity of cooperation in this study indicates that the rationality and selfishness of a single agent in adjusting social ties can lead to the progress of altruism of the whole population.

Influence of dispatching rules on average production lead time for multi-stage production systems.

PubMed

Hübl, Alexander; Jodlbauer, Herbert; Altendorfer, Klaus

2013-08-01

In this paper the influence of different dispatching rules on the average production lead time is investigated. Two theorems based on covariance between processing time and production lead time are formulated and proved theoretically. Theorem 1 links the average production lead time to the "processing time weighted production lead time" for the multi-stage production systems analytically. The influence of different dispatching rules on average lead time, which is well known from simulation and empirical studies, can be proved theoretically in Theorem 2 for a single stage production system. A simulation study is conducted to gain more insight into the influence of dispatching rules on average production lead time in a multi-stage production system. We find that the "processing time weighted average production lead time" for a multi-stage production system is not invariant of the applied dispatching rule and can be used as a dispatching rule independent indicator for single-stage production systems.

Mutation-Linked Defective Inter-Domain Interactions within Ryanodine Receptor Cause Aberrant Ca2+ Release Leading to Catecholaminergic Polymorphic Ventricular Tachycardia

PubMed Central

Suetomi, Takeshi; Yano, Masafumi; Uchinoumi, Hitoshi; Fukuda, Masakazu; Hino, Akihiro; Ono, Makoto; Xu, Xiaojuan; Tateishi, Hiroki; Okuda, Shinichi; Doi, Masahiro; Kobayashi, Shigeki; Ikeda, Yasuhiho; Yamamoto, Takeshi; Ikemoto, Noriaki; Matsuzaki, Masunori

2011-01-01

Background The molecular mechanism by which catecholaminergic polymorphic ventricular tachycardia (CPVT) is induced by single amino acid mutations within the cardiac ryanodine receptor (RyR2) remains elusive. Here, we investigated mutation-induced conformational defects of RyR2 using a knock-in (KI) mouse model expressing the human CPVT-associated RyR2 mutant (S2246L; Serine to Leucine mutation at the residue 2246). Methods and Results All KI mice we examined produced VT after exercise on a treadmill. cAMP-dependent increase in the frequency of Ca2+ sparks was more pronounced in saponin-permeabilized KI cardiomyocytes than in WT cardiomyocytes. Site-directed fluorescent labeling and quartz microbalance assays of the specific binding of DP2246 (a peptide corresponding to the 2232–2266 region: the 2246 domain) showed that DP2246 binds with the K201-binding sequence of RyR2 (1741– 2270). Introduction of S2246L mutation into the DP2246 increased the affinity of peptide binding. Fluorescence quench assays of inter-domain interactions within RyR2 showed that tight interaction of the 2246 domain/K201-binding domain is coupled with domain unzipping of the N-terminal (1-600)/central (2000–2500) domain pair in an allosteric manner. Dantrolene corrected the mutation-caused domain unzipping of the domain switch, and stopped the exercise-induced ventricular tachycardia. Conclusions The CPVT-linked mutation of RyR2, S2246L, causes an abnormally tight local sub-domain/sub-domain interaction within the central domain involving the mutation site, which induces defective interaction between the N-terminal and central domains. This results in an erroneous activation of Ca2+ channel in a diastolic state reflecting on the increased Ca2+ spark frequency, which then leads to lethal arrhythmia. PMID:21768539

Mutation-linked defective interdomain interactions within ryanodine receptor cause aberrant Ca²⁺release leading to catecholaminergic polymorphic ventricular tachycardia.

PubMed

Suetomi, Takeshi; Yano, Masafumi; Uchinoumi, Hitoshi; Fukuda, Masakazu; Hino, Akihiro; Ono, Makoto; Xu, Xiaojuan; Tateishi, Hiroki; Okuda, Shinichi; Doi, Masahiro; Kobayashi, Shigeki; Ikeda, Yasuhiro; Yamamoto, Takeshi; Ikemoto, Noriaki; Matsuzaki, Masunori

2011-08-09

The molecular mechanism by which catecholaminergic polymorphic ventricular tachycardia is induced by single amino acid mutations within the cardiac ryanodine receptor (RyR2) remains elusive. In the present study, we investigated mutation-induced conformational defects of RyR2 using a knockin mouse model expressing the human catecholaminergic polymorphic ventricular tachycardia-associated RyR2 mutant (S2246L; serine to leucine mutation at the residue 2246). All knockin mice we examined produced ventricular tachycardia after exercise on a treadmill. cAMP-dependent increase in the frequency of Ca²⁺ sparks was more pronounced in saponin-permeabilized knockin cardiomyocytes than in wild-type cardiomyocytes. Site-directed fluorescent labeling and quartz microbalance assays of the specific binding of DP2246 (a peptide corresponding to the 2232 to 2266 region: the 2246 domain) showed that DP2246 binds with the K201-binding sequence of RyR2 (1741 to 2270). Introduction of S2246L mutation into the DP2246 increased the affinity of peptide binding. Fluorescence quench assays of interdomain interactions within RyR2 showed that tight interaction of the 2246 domain/K201-binding domain is coupled with domain unzipping of the N-terminal (1 to 600)/central (2000 to 2500) domain pair in an allosteric manner. Dantrolene corrected the mutation-caused domain unzipping of the domain switch and stopped the exercise-induced ventricular tachycardia. The catecholaminergic polymorphic ventricular tachycardia-linked mutation of RyR2, S2246L, causes an abnormally tight local subdomain-subdomain interaction within the central domain involving the mutation site, which induces defective interaction between the N-terminal and central domains. This results in an erroneous activation of Ca²⁺ channel in a diastolic state reflecting on the increased Ca²⁺ spark frequency, which then leads to lethal arrhythmia.

Polychlorinated biphenyls and links to cardiovascular disease.

PubMed

Perkins, Jordan T; Petriello, Michael C; Newsome, Bradley J; Hennig, Bernhard

2016-02-01

The pathology of cardiovascular disease is multi-faceted, with links to many modifiable and non-modifiable risk factors. Epidemiological evidence now implicates exposure to persistent organic pollutants, such as polychlorinated biphenyls (PCBs), with an increased risk of developing diabetes, hypertension, and obesity; all of which are clinically relevant to the onset and progression of cardiovascular disease. PCBs exert their cardiovascular toxicity either directly or indirectly via multiple mechanisms, which are highly dependent on the type and concentration of PCBs present. However, many PCBs may modulate cellular signaling pathways leading to common detrimental outcomes including induction of chronic oxidative stress, inflammation, and endocrine disruption. With the abundance of potential toxic pollutants increasing globally, it is critical to identify sensible means of decreasing associated disease risks. Emerging evidence now implicates a protective role of lifestyle modifications such as increased exercise and/or nutritional modulation via anti-inflammatory foods, which may help to decrease the vascular toxicity of PCBs. This review will outline the current state of knowledge linking coplanar and non-coplanar PCBs to cardiovascular disease and describe the possible molecular mechanism of this association.

Lead exposures in the human environment. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elias, R.W.

Humans consume lead by inhaling air, drinking beverages, eating food and ingesting dust. The natural source of this lead is primarily soil. Anthropogenic sources are lead in gasoline, fossil fuels and industrial products and processes. Lead is ubiquitous in the human environment, and pinpointing the primary sources of lead in any particular environmental component is difficult. Nevertheless, our purpose is to describe the total exposure of humans to environmental lead and to determine the sources of lead contributing to this exposure. The total exposure is the total amount of lead consumed by ingestion and inhalation. Excluding lead exposure from choicemore » or circumstance, a baseline level of potential human exposure can be defined for a normal individual eating a typical diet and living in a non-urban community remote from industrial sources of lead in a house without lead-based paints. Beyond this level, additive exposure factors can be determined for other environments (e.g. urban, occupational and smelter communities) and for certain habits and activities (e.g. pica, smoking, drinking and hobbies), with variation for age, sex or socioeconomic status.« less

Extracellular matrix mineralization in periodontal tissues: Noncollagenous matrix proteins, enzymes, and relationship to hypophosphatasia and X-linked hypophosphatemia

PubMed Central

McKee, Marc D.; Hoac, Betty; Addison, William N.; Barros, Nilana M.T.; Millán, José Luis; Chaussain, Catherine

2013-01-01

As broadly demonstrated for the formation of a functional skeleton, proper mineralization of periodontal alveolar bone and teeth – where calcium phosphate crystals are deposited and grow within an extracellular matrix – is essential to dental function. Mineralization defects in tooth dentin and cementum of the periodontium invariably lead to a weak (soft or brittle) dentition such that teeth become loose and prone to infection and are lost prematurely. Mineralization of the extremities of periodontal ligament fibres (Sharpey's fibres) where they insert into tooth cementum and alveolar bone is also essential for the function of the tooth suspensory apparatus in occlusion and mastication. Molecular determinants of mineralization in these tissues include mineral ion concentrations (phosphate and calcium), pyrophosphate, small integrin-binding ligand N-linked glycoproteins (SIBLINGs), and matrix vesicles. Amongst the enzymes important in regulating these mineralization determinants, two are discussed at length here with clinical examples given, namely tissue-nonspecific alkaline phosphatase (TNAP) and phosphate-regulating gene with homologies to endopeptidases on the X chromosome (PHEX). Inactivating mutations in these enzymes in humans and in mouse models lead to the soft bones and teeth characteristic of hypophosphatasia (HPP) and X-linked hypophosphatemia (XLH), respectively, where levels of local and systemic circulating mineralization determinants are perturbed. In XLH, in addition to renal phosphate wasting causing low circulating phosphate levels, phosphorylated mineralization-regulating SIBLING proteins such as matrix extracellular phosphoglycoprotein (MEPE) and osteopontin (OPN), and the phosphorylated peptides proteolytically released from them such as the acidic serine- and aspartate-rich motif (ASARM) peptide, may accumulate locally to impair mineralization in this disease. PMID:23931057

Facile fabrication of core cross-linked micelles by RAFT polymerization and enzyme-mediated reaction.

PubMed

Wu, Yukun; Lai, Quanyong; Lai, Shuqi; Wu, Jing; Wang, Wei; Yuan, Zhi

2014-06-01

Polymeric micelles formed in aqueous solution by assembly of amphiphilic block copolymers have been extensively investigated due to their great potential as drug carriers. However, the stability of polymeric assembly is still one of the major challenges in delivering drugs to tissues and cells. Here, we report a facile route to fabricate core cross-linked (CCL) micelles using an enzymatic polymerization as the cross-linking method. We present synthesis of poly(ethylene glycol)-block-poly(N-isopropyl acrylamide-co-N-(4-hydroxyphenethyl) acrylamide) diblock copolymer PEG-b-P(NIPAAm-co-NHPAAm) via reversible addition-fragmentation chain transfer (RAFT) polymerization. The diblock copolymer was then self-assembled into non-cross-linked (NCL) micelles upon heating above the lower critical solution temperature (LCST), and subsequently cross-linked using horseradish peroxidase (HRP) and hydrogen peroxide (H2O2) as enzyme and oxidant. The characterization of the diblock copolymer and micelles were studied by NMR, DLS, UV-vis, and fluorescence spectroscopy. The fluorescence study reveals that the cross-linking process endows the micelles with much lower critical micelle concentration (CMC). In addition, the drug release study shows that the CCL micelles have lower release amount of doxorubicin (DOX) than the NCL micelles due to the enhanced stability of the CCL micelles by core cross-linking process. Copyright © 2014 Elsevier B.V. All rights reserved.

Collagen cross-linking: insights on the evolution of metazoan extracellular matrix.

PubMed

Rodriguez-Pascual, Fernando; Slatter, David Anthony

2016-11-23

Collagens constitute a large family of extracellular matrix (ECM) proteins that play a fundamental role in supporting the structure of various tissues in multicellular animals. The mechanical strength of fibrillar collagens is highly dependent on the formation of covalent cross-links between individual fibrils, a process initiated by the enzymatic action of members of the lysyl oxidase (LOX) family. Fibrillar collagens are present in a wide variety of animals, therefore often being associated with metazoan evolution, where the emergence of an ancestral collagen chain has been proposed to lead to the formation of different clades. While LOX-generated collagen cross-linking metabolites have been detected in different metazoan families, there is limited information about when and how collagen acquired this particular modification. By analyzing telopeptide and helical sequences, we identified highly conserved, potential cross-linking sites throughout the metazoan tree of life. Based on this analysis, we propose that they have importantly contributed to the formation and further expansion of fibrillar collagens.

[Factors related to the blood lead level in children 6 to 30 months old in the Prospective Lead Study in Mexico City].

PubMed

Rothenberg, S J; Schnaas-Arrieta, L; Pérez-Guerrero, I A; Hernández-Cervantes, R; Martínez-Medina, S; Perroni-Hernández, E

1993-01-01

A majority of the sample of children (N = 160-121, ages 6-30 months) from the Mexico City Prospective Lead Study exceeds the lowest limit action level (10 micrograms/dl) of the Centers for Disease Control standards for childhood lead exposure. Over one-third of the sample at 18 months and 24 months exceeds the action level (15 micrograms/dl) for aggressive intervention. Diet plays an important role in regulating early childhood blood lead levels. Fresh milk and breast feeding are associated with lower lead levels, but extended breast feeding is related to elevated lead levels. Low income and poor maternal education are associated with higher lead concentration in children. Child consumption of canned milk and juice, up to this date, is associated with elevated child lead levels. Canned products sealed with lead are disappearing from Mexican markets. Efforts to improve childhood nutrition and poverty may be expected to have the additional benefit of lowering lead levels of Mexican children.

Links between Antisocial Behavior and Depressed Mood: The Role of Life Events and Attributional Style

ERIC Educational Resources Information Center

Rowe, Richard; Maughan, Barbara; Eley, Thalia C.

2006-01-01

Comorbidity between antisocial behavior and depression in adolescence is widely recognized. This paper examines whether links with depressed mood differ among three subtypes of antisocial behavior: oppositionality, physical aggression and delinquency. In addition we examine two possible contributors to these links: negative life events that are…

CAN FLUORIDATION AFFECT LEAD (II) IN POTABLE WATER? HEXAFLUOROSILICATE AND FLUORIDE EQUILIBRIA IN AQUEOUS SOLUTION

EPA Science Inventory

Recent reports have attempted to show that 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 hexafluorosilicate hydrolysi...

Terminal addition in a cellular world.

PubMed

Torday, J S; Miller, William B

2018-07-01

Recent advances in our understanding of evolutionary development permit a reframed appraisal of Terminal Addition as a continuous historical process of cellular-environmental complementarity. Within this frame of reference, evolutionary terminal additions can be identified as environmental induction of episodic adjustments to cell-cell signaling patterns that yield the cellular-molecular pathways that lead to differing developmental forms. Phenotypes derive, thereby, through cellular mutualistic/competitive niche constructions in reciprocating responsiveness to environmental stresses and epigenetic impacts. In such terms, Terminal Addition flows according to a logic of cellular needs confronting environmental challenges over space-time. A reconciliation of evolutionary development and Terminal Addition can be achieved through a combined focus on cell-cell signaling, molecular phylogenies and a broader understanding of epigenetic phenomena among eukaryotic organisms. When understood in this manner, Terminal Addition has an important role in evolutionary development, and chronic disease might be considered as a form of 'reverse evolution' of the self-same processes. Copyright © 2017. Published by Elsevier Ltd.

Impaired plasticity of macrophages in X-linked adrenoleukodystrophy.

PubMed

Weinhofer, Isabelle; Zierfuss, Bettina; Hametner, Simon; Wagner, Magdalena; Popitsch, Niko; Machacek, Christian; Bartolini, Barbara; Zlabinger, Gerhard; Ohradanova-Repic, Anna; Stockinger, Hannes; Köhler, Wolfgang; Höftberger, Romana; Regelsberger, Günther; Forss-Petter, Sonja; Lassmann, Hans; Berger, Johannes

2018-05-30

X-linked adrenoleukodystrophy is caused by ATP-binding cassette transporter D1 (ABCD1) mutations and manifests by default as slowly progressive spinal cord axonopathy with associated demyelination (adrenomyloneuropathy). In 60% of male cases, however, X-linked adrenoleukodystrophy converts to devastating cerebral inflammation and demyelination (cerebral adrenoleukodystrophy) with infiltrating blood-derived monocytes and macrophages and cytotoxic T cells that can only be stopped by allogeneic haematopoietic stem cell transplantation or gene therapy at an early stage of the disease. Recently, we identified monocytes/macrophages but not T cells to be severely affected metabolically by ABCD1 deficiency. Here we found by whole transcriptome analysis that, although monocytes of patients with X-linked adrenoleukodystrophy have normal capacity for macrophage differentiation and phagocytosis, they are pro-inflammatory skewed also in patients with adrenomyloneuropathy in the absence of cerebral inflammation. Following lipopolysaccharide activation, the ingestion of myelin debris, normally triggering anti-inflammatory polarization, did not fully reverse the pro-inflammatory status of X-linked adrenoleukodystrophy macrophages. Immunohistochemistry on post-mortem cerebral adrenoleukodystrophy lesions reflected the activation pattern by prominent presence of enlarged lipid-laden macrophages strongly positive for the pro-inflammatory marker co-stimulatory molecule CD86. Comparative analyses of lesions with matching macrophage density in cases of cerebral adrenoleukodystrophy and acute multiple sclerosis showed a similar extent of pro-inflammatory activation but a striking reduction of anti-inflammatory mannose receptor (CD206) and haemoglobin-haptoglobin receptor (CD163) expression on cerebral adrenoleukodystrophy macrophages. Accordingly, ABCD1-deficiency leads to an impaired plasticity of macrophages that is reflected in incomplete establishment of anti-inflammatory responses

Childhood lead exposure and sexually transmitted infections: New evidence.

PubMed

Nelson, Erik J; Shacham, Enbal; Boutwell, Brian B; Rosenfeld, Richard; Schootman, Mario; Vaughn, Michael; Lewis, Roger

2015-11-01

The adverse health effects of lead exposure in children are well documented and include intellectual and behavioral maladies. Childhood lead exposure has also been linked to impulsive behaviors, which, in turn, are associated with a host of negative health outcomes including an increased risk for sexually transmitted infections (STI). The purpose of this study was to assess the association of lead exposure with STI rates across census tracts in St. Louis City, Missouri. Incident cases of gonorrhea and chlamydia (GC) during 2011 were identified from the Missouri Department of Health and Senior Services and aggregated by census tract. We also geocoded the home address of 59,645 children >72 months in age who had blood lead level tests performed in St. Louis City from 1996 to 2007. Traditional regression and Bayesian spatial models were used to determine the relationship between GC and lead exposure while accounting for confounders (condom and alcohol availability, crime, and an index of concentrated disadvantage). Incident GC rates were found to cluster across census tracts (Moran's I=0.13, p=0.006). After accounting for confounders and their spatial dependence, a linear relationship existed between lead exposure and GC incidence across census tracts, with higher GC rates occurring in the northern part of St. Louis City At the census-tract level, higher lead exposure is associated with higher STI rates. Visualizing these patterns through maps may help deliver targeted interventions to reduce geographic disparities in GC rates. Copyright © 2015 Elsevier Inc. All rights reserved.

Light-induced cross-linking and post-cross-linking modification of polyglycidol.

PubMed

Marquardt, F; Bruns, M; Keul, H; Yagci, Y; Möller, M

2018-02-08

The photoinduced radical generation process has received renewed interest due to its economic and ecological appeal. Herein the light-induced cross-linking of functional polyglycidol and its post-cross-linking modification are presented. Linear polyglycidol was first functionalized with a tertiary amine in a two-step reaction. Dimethylaminopropyl functional polyglycidol was cross-linked in a UV-light mediated reaction with camphorquinone as a type II photoinitiator. The cross-linked polyglycidol was further functionalized by quaternization with various organoiodine compounds. Aqueous dispersions of the cross-linked polymers were investigated by means of DLS and zeta potential measurements. Polymer films were evaluated by DSC and XPS.

Active link selection for efficient semi-supervised community detection

NASA Astrophysics Data System (ADS)

Yang, Liang; Jin, Di; Wang, Xiao; Cao, Xiaochun

2015-03-01

Several semi-supervised community detection algorithms have been proposed recently to improve the performance of traditional topology-based methods. However, most of them focus on how to integrate supervised information with topology information; few of them pay attention to which information is critical for performance improvement. This leads to large amounts of demand for supervised information, which is expensive or difficult to obtain in most fields. For this problem we propose an active link selection framework, that is we actively select the most uncertain and informative links for human labeling for the efficient utilization of the supervised information. We also disconnect the most likely inter-community edges to further improve the efficiency. Our main idea is that, by connecting uncertain nodes to their community hubs and disconnecting the inter-community edges, one can sharpen the block structure of adjacency matrix more efficiently than randomly labeling links as the existing methods did. Experiments on both synthetic and real networks demonstrate that our new approach significantly outperforms the existing methods in terms of the efficiency of using supervised information. It needs ~13% of the supervised information to achieve a performance similar to that of the original semi-supervised approaches.

Active link selection for efficient semi-supervised community detection

PubMed Central

Yang, Liang; Jin, Di; Wang, Xiao; Cao, Xiaochun

2015-01-01

Several semi-supervised community detection algorithms have been proposed recently to improve the performance of traditional topology-based methods. However, most of them focus on how to integrate supervised information with topology information; few of them pay attention to which information is critical for performance improvement. This leads to large amounts of demand for supervised information, which is expensive or difficult to obtain in most fields. For this problem we propose an active link selection framework, that is we actively select the most uncertain and informative links for human labeling for the efficient utilization of the supervised information. We also disconnect the most likely inter-community edges to further improve the efficiency. Our main idea is that, by connecting uncertain nodes to their community hubs and disconnecting the inter-community edges, one can sharpen the block structure of adjacency matrix more efficiently than randomly labeling links as the existing methods did. Experiments on both synthetic and real networks demonstrate that our new approach significantly outperforms the existing methods in terms of the efficiency of using supervised information. It needs ~13% of the supervised information to achieve a performance similar to that of the original semi-supervised approaches. PMID:25761385

Chronic Lead Intoxication From Eating Wild-Harvested Game.

PubMed

Buenz, Eric J; Parry, Gareth J

2018-05-01

The purpose of this article is to determine if conversion from eating wild game harvested with lead-based ammunition to nonlead-based ammunition results in lower blood lead levels. Supersonic injection of toxin-leeching frangible projectiles into food is intuitively bad. As much as 95% of the ~13.7 million hunters in the United States choose shrapnel-inducing lead bullets to kill game; in addition, not harvesting meat is an incarcerable crime. A lead ammunition ban on certain federal lands was recently rescinded and the National Rifle Association refutes any risk from eating lead bullet-harvested game. A patient subsisting solely on lead-shot meat was converted to non-lead ammunition and his blood lead level tracked. Concomitant with his conversion to nonlead ammunition, a controlled experiment was performed using the patient's bullets to determine his daily lead intake from lead-shot meat. While eating lead-shot meat, the patient was consuming 259.3 ± 235.6 µg of lead daily and his blood lead level was 74.7 µg/dL. Conversion to nonlead ammunition was associated with a reduced blood lead level. Unsafe blood lead levels can occur from eating game harvested with lead ammunition. Physicians should warn hunting patients of this potential risk and counsel them about the availability of nonlead ammunition alternatives. Copyright © 2018 Elsevier Inc. All rights reserved.

A CXCL1 paracrine network links cancer chemoresistance and metastasis

PubMed Central

Acharyya, Swarnali; Oskarsson, Thordur; Vanharanta, Sakari; Malladi, Srinivas; Kim, Juliet; Morris, Patrick G.; Manova-Todorova, Katia; Leversha, Margaret; Hogg, Nancy; Seshan, Venkatraman E.; Norton, Larry; Brogi, Edi; Massagué, Joan

2012-01-01

Metastasis and chemoresistance in cancer are linked phenomena but the molecular basis for this link is unknown. We uncovered a network of paracrine signals between carcinoma, myeloid and endothelial cells that drives both processes in breast cancer. Cancer cells that overexpress CXCL1 and 2 by transcriptional hyperactivation or 4q21 amplification are primed for survival in metastatic sites. CXCL1/2 attract CD11b+Gr1+ myeloid cells into the tumor, which produce chemokines including S100A8/9 that enhance cancer cell survival. While chemotherapeutic agents kill cancer cells, these treatments trigger a parallel stromal reaction leading to TNF-α production by endothelial and other stromal cells. TNF-α heightens the expression of CXCL1/2 in cancer cells, thus amplifying the CXCL1/2-S100A8/9 loop and causing chemoresistance. CXCR2 blockers break this cycle, augmenting the efficacy of chemotherapy against breast tumors and particularly against metastasis. This network of endothelial-carcinoma-myeloid signaling interactions provides a mechanism linking chemoresistance and metastasis, with opportunities for intervention. PMID:22770218

Experimental lead intoxication in dogs: a comparison of blood lead and urinary delta-aminolevulinic acid following intoxication and chelation therapy.

PubMed Central

Green, R A; Selby, L A; Zumwalt, R W

1978-01-01

Intravenous lead administration to dogs produced an acute syndrome of lead intoxication charcterized by depression, vomiting, anorexia and weight loss. The effect of chelation therapy with calcium disodium ethylene diamine tetraacetate, penicillamine or both was determined by serially monitoring changes in blood lead and urine delta-aminolevulinic acid. Following therapy, blood lead values were significantly lower in chelated dogs than non-treated lead exposed dogs on days 7 and 10. Urine delta-aminolevulinic acid at day 7 was significantly higher in untreated lead exposed dogs than in other groups. There was no significant difference in blood lead or urine delta-aminolevulinic acid between lead intoxicated dogs which underwent the indicated chelation therapy protocols. There was, however, a trend for higher urinary delta-aminolevulinic acid excretion in those intoxicated dogs undergoing calcium disodium ethylene diamine tetraacetate therapy as opposed to those undergoing penicilamine therapy. There was no significant correlation between blood lead and urinary delta-aminolevulinic acid previous to lead exposure. However, after lead exposure significant correlation was present at days 4, 7, 10 and 14. Certain lead exposed dogs following chelation therapy were noted to have normal blood lead levels but elevated urinary delta-aminolevulinic acid suggesting that blood lead does not always correlate with metabolic effects of lead in the body. Urinary delta-aminolevulinic acid was therefore recommended as an additional laboratory parameter which improved assessment of lead exposure in dogs, particularly in determining adequacy of chelation therapy. PMID:667707

Information-theoretic approach to lead-lag effect on financial markets

NASA Astrophysics Data System (ADS)

Fiedor, Paweł

2014-08-01

Recently the interest of researchers has shifted from the analysis of synchronous relationships of financial instruments to the analysis of more meaningful asynchronous relationships. Both types of analysis are concentrated mostly on Pearson's correlation coefficient and consequently intraday lead-lag relationships (where one of the variables in a pair is time-lagged) are also associated with them. Under the Efficient-Market Hypothesis such relationships are not possible as all information is embedded in the prices, but in real markets we find such dependencies. In this paper we analyse lead-lag relationships of financial instruments and extend known methodology by using mutual information instead of Pearson's correlation coefficient. Mutual information is not only a more general measure, sensitive to non-linear dependencies, but also can lead to a simpler procedure of statistical validation of links between financial instruments. We analyse lagged relationships using New York Stock Exchange 100 data not only on an intraday level, but also for daily stock returns, which have usually been ignored.

The influence of Pb addition on the properties of fly ash-based geopolymers.

PubMed

Nikolić, Violeta; Komljenović, Miroslav; Džunuzović, Nataša; Miladinović, Zoran

2018-05-15

Preventing or reducing negative effects on the environment from the waste landfilling is the main goal defined by the European Landfill Directive. Generally geopolymers can be considered as sustainable binders for immobilization of hazardous wastes containing different toxic elements. In this paper the influence of addition of high amount of lead on structure, strength, and leaching behavior (the effectiveness of Pb immobilization) of fly ash-based geopolymers depending on the geopolymer curing conditions was investigated. Lead was added during the synthesis of geopolymers in the form of highly soluble salt - lead-nitrate. Structural changes of geopolymers as a result of lead addition/immobilization were assessed by means of XRD, SEM/EDS, and 29 Si MAS NMR analysis. Investigated curing conditions significantly influenced structure, strength and leaching behavior of geopolymers. High addition of lead caused a sizeable decrease in compressive strength of geopolymers and promoted formation of aluminum-deficient aluminosilicate gel (depolymerization of aluminosilicate gel), regardless of the curing conditions investigated. According to the EUWAC limitations, 4% of lead was successfully immobilized by fly ash-based geopolymers cured for 28 days in a humid chamber at room temperature. Copyright © 2018 Elsevier B.V. All rights reserved.

Linking mortuary data improves vital statistics on cause of death of children under five years in the Western Cape Province of South Africa.

PubMed

Groenewald, Pam; Bradshaw, Debbie; Neethling, Ian; Martin, Lorna J; Dempers, Johan; Morden, Erna; Zinyakatira, Nesbert; Coetzee, David

2016-01-01

Reducing child mortality requires good information on its causes. Whilst South African vital registration data have improved, the quality of cause-of-death data remains inadequate. To improve this, data from death certificates were linked with information from forensic mortuaries in Western Cape Province. A local mortality surveillance system was established in 2007 by the Western Cape Health Department to improve data quality. Cause-of-death data were captured from copies of death notification forms collected at Department of Home Affairs Offices. Using unique identifiers, additional forensic mortuary data were linked with mortality surveillance system records. Causes of death were coded to the ICD-10 classification. Causes of death in children under five were compared with those from vital registration data for 2011. Cause-of-death data were markedly improved with additional data from forensic mortuaries. The proportion of ill-defined causes was halved (25-12%), and leading cause rankings changed. Lower respiratory tract infections moved above prematurity to rank first, accounting for 20.8% of deaths and peaking in infants aged 1-3 months. Only 11% of deaths from lower respiratory tract infections occurred in hospital, resulting in 86% being certified in forensic mortuaries. Road traffic deaths increased from 1.1-3.1% (27-75) and homicides from 3 to 28. The quality and usefulness of cause-of-death information for children in the WC was enhanced by linking mortuary and vital registration data. Given the death profile, interventions are required to prevent and manage LRTI, diarrhoea and injuries and to reduce neonatal deaths. © 2015 John Wiley & Sons Ltd.

Wallops Low Elevation Link Analysis for the Constellation Launch/Ascent Links

NASA Technical Reports Server (NTRS)

Cheung, Keith; Ho, C.; Kantak, A.; Lee, C.; Tye, R.; Richards, E.; Sham, C.; Schlesinger, A.; Barritt, B.

2011-01-01

To execute the President's Vision for Space Exploration, the Constellation Program (CxP) was formed to build the next generation spacecraft Orion and launch vehicles Ares, to transport human and cargo to International Space Station (ISS), moon, and Mars. This paper focuses on the detailed link analysis for Orion/Ares s launch and ascent links with Wallops 11.3m antenna (1) Orion's Dissimilar Voice link: 10.24 Kbps, 2-way (2) Ares Developmental Flight Instrument link, 20 Mbps, downlink. Three launch trajectories are considered: TD7-E, F (Feb), and G (Aug). In certain launch scenarios, the critical events of main engine cutoff (MECO) and Separation occur during the low elevation regime of WFF s downrange -- less than 5 degree elevation angle. The goal of the study is to access if there is enough link margins for WFF to track the DV and DFI links.

Lead Exposure in Free-Flying Turkey Vultures Is Associated with Big Game Hunting in California

PubMed Central

Kelly, Terra R.; Johnson, Christine K.

2011-01-01

Predatory and scavenging birds are at risk of lead exposure when they feed on animals injured or killed by lead ammunition. While lead ammunition has been banned from waterfowl hunting in North America for almost two decades, lead ammunition is still widely used for hunting big game and small game animals. In this study, we evaluated the association between big game hunting and blood lead concentration in an avian scavenger species that feeds regularly on large mammals in California. We compared blood lead concentration in turkey vultures within and outside of the deer hunting season, and in areas with varying wild pig hunting intensity. Lead exposure in turkey vultures was significantly higher during the deer hunting season compared to the off-season, and blood lead concentration was positively correlated with increasing wild pig hunting intensity. Our results link lead exposure in turkey vultures to deer and wild pig hunting activity at these study sites, and we provide evidence that spent lead ammunition in carrion poses a significant risk of lead exposure to scavengers. PMID:21494326

Lead exposure in free-flying turkey vultures is associated with big game hunting in California.

PubMed

Kelly, Terra R; Johnson, Christine K

2011-04-06

Predatory and scavenging birds are at risk of lead exposure when they feed on animals injured or killed by lead ammunition. While lead ammunition has been banned from waterfowl hunting in North America for almost two decades, lead ammunition is still widely used for hunting big game and small game animals. In this study, we evaluated the association between big game hunting and blood lead concentration in an avian scavenger species that feeds regularly on large mammals in California. We compared blood lead concentration in turkey vultures within and outside of the deer hunting season, and in areas with varying wild pig hunting intensity. Lead exposure in turkey vultures was significantly higher during the deer hunting season compared to the off-season, and blood lead concentration was positively correlated with increasing wild pig hunting intensity. Our results link lead exposure in turkey vultures to deer and wild pig hunting activity at these study sites, and we provide evidence that spent lead ammunition in carrion poses a significant risk of lead exposure to scavengers.

3. BUNKER HILL LEAD SMELTER. VIEW IS FROM CIA TO ...

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

3. BUNKER HILL LEAD SMELTER. VIEW IS FROM CIA TO THE SOUTHWEST. BUILDINGS NOTED IN ID-29-2 APPEAR, IN ADDITION TO DRY ORE PLANT AND BONNOT COAL PULVERIZING EQUIPMENT BUILDING ON THE RIGHT. - Bunker Hill Lead Smelter, Bradley Rail Siding, Kellogg, Shoshone County, ID

X-Ray protective clothing: does DIN 6857-1 allow an objective comparison between lead-free and lead-composite materials?

PubMed

Eder, H; Schlattl, Helmut; Hoeschen, C

2010-05-01

The validity of DIN 6857-1 to establish lead equivalence for protective clothing is evaluated by Monte Carlo simulations and measurements. Commercially available protective clothing made of lead, lead-free and lead-composite materials has been tested regarding its protective efficacy. The analysis has been performed on the one hand in accordance with the test conditions described in the manufacturing standard DIN EN 61331-3 and on the other hand following the new DIN 6857-1 standard. Additionally, measurements have been carried out under simulated patient conditions by using an Alderson-Rando phantom. Following DIN EN 61331-3, the lead-free protective clothing achieved the required protective efficacy only at a restricted tube-voltage range. The test according to DIN 6857-1 showed that the protective criteria were fulfilled only by one lead-composite apron, but not by the three lead-free aprons examined. Thus, in order to guarantee the same protection as lead between 50 and 120 kV, the conditions of DIN 6857-1 must be fulfilled. A modification of DIN EN 61331-3 to account for secondary radiation is strongly advised in the case of lead-free materials. In summary, most of the protective lead-free aprons in use should be used with care, particularly for examinations with a high dose. Georg Thieme Verlag KG Stuttgart * New York.

Integrin-Linked Kinase Deletion in the Developing Lens Leads to Capsule Rupture, Impaired Fiber Migration and Non-Apoptotic Epithelial Cell Death

PubMed Central

Cammas, Laura; Wolfe, Jordan; Choi, Sue-Yeon; Dedhar, Shoukat; Beggs, Hilary E

2012-01-01

Purpose. The lens is a powerful model system to study integrin-mediated cell-matrix interaction in an in vivo context, as it is surrounded by a true basement membrane, the lens capsule. To characterize better the function of integrin-linked kinase (ILK), we examined the phenotypic consequences of its deletion in the developing mouse lens. Methods. ILK was deleted from the embryonic lens either at the time of placode invagination using the Le-Cre line or after initial lens formation using the Nestin-Cre line. Results. Early deletion of ILK leads to defects in extracellular matrix deposition that result in lens capsule rupture at the lens vesicle stage (E13.5). If ILK was deleted at a later time-point after initial establishment of the lens capsule, rupture was prevented. Instead, ILK deletion resulted in secondary fiber migration defects and, most notably, in cell death of the anterior epithelium (E18.5 − P0). Remarkably, dying cells did not stain positively for terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) or activated-caspase 3, suggesting that they were dying from a non-apoptotic mechanism. Moreover, cross to a Baxfl/fl/Bak−/− mouse line that is resistant to most forms of apoptosis failed to promote cell survival in the ILK-deleted lens epithelium. Electron microscopy revealed the presence of numerous membranous vacuoles containing degrading cellular material. Conclusions. Our study reveals a role for ILK in extracellular matrix organization, fiber migration, and cell survival. Furthermore, to our knowledge we show for the first time that ILK disruption results in non-apoptotic cell death in vivo. PMID:22491404

Evaluation of epigallocatechin-3-gallate (EGCG) cross-linked collagen membranes and concerns on osteoblasts.

PubMed

Chu, Chenyu; Deng, Jia; Xiang, Lin; Wu, Yingying; Wei, Xiawei; Qu, Yili; Man, Yi

2016-10-01

Collagen membranes have ideal biological and mechanical properties for supporting infiltration and proliferation of osteoblasts and play a vital role in guided bone regeneration (GBR). However, pure collagen can lead to inflammation, resulting in progressive bone resorption. Therefore, a method for regulating the level of inflammatory cytokines at surgical sites is paramount for the healing process. Epigallocatechin-3-gallate (EGCG) is a component extracted from green tea with numerous biological activities including an anti-inflammatory effect. Herein, we present a novel cross-linked collagen membrane containing different concentrations of EGCG (0.0064%, 0.064%, and 0.64%) to regulate the level of inflammatory factors secreted by pre-osteoblast cells; improve cell proliferation; and increase the tensile strength, wettability, and thermal stability of collagen membranes. Scanning electron microscope images show that the surfaces of collagen membranes became smoother and the collagen fiber diameters became larger with EGCG treatment. Measurement of the water contact angle demonstrated that introducing EGCG improved membrane wettability. Fourier transform infrared spectroscopy analyses indicated that the backbone of collagen was intact, and the thermal stability was significant improved in differential scanning calorimetry. The mechanical properties of 0.064% and 0.64% EGCG-treated collagen membranes were 1.5-fold greater than those of the control. The extent of cross-linking was significantly increased, as determined by a 2,4,6-trinitrobenzenesulfonic acid solution assay. The Cell Counting Kit-8 (CCK-8) and live/dead assays revealed that collagen membrane cross-linked by 0.0064% EGCG induced greater cell proliferation than pure collagen membranes. Additionally, real-time polymerase chain reaction and enzyme-linked immunosorbent assay results showed that EGCG significantly affected the production of inflammatory factors secreted by MC3T3-E1 cells. Taken together, our

Biomarker responses of Peromyscus leucopus exposed to lead and cadmium in the Southeast Missouri Lead Mining District

USGS Publications Warehouse

Beyer, W. Nelson; Casteel, Stan W.; Friedrichs, Kristen R.; Gramlich, Eric; Houseright, Ruth A.; Nichols, John W.; Karouna-Renier, Natalie; Kim, Dae Young; Rangen, Kathleen; Rattner, Barnett A.; Schultz, Sandra

2018-01-01

Biomarker responses and histopathological lesions have been documented in laboratory mammals exposed to elevated concentrations of lead and cadmium. The exposure of white-footed mice (Peromyscus leucopus) to these metals and the potential associated toxic effects were examined at three contaminated sites in the Southeast Missouri Lead Mining District and at a reference site in MO, USA. Mice from the contaminated sites showed evidence of oxidative stress and reduced activity of red blood cell δ-aminolevulinic acid dehydratase (ALAD). Histological examinations of the liver and kidney, cytologic examination of blood smears, and biomarkers of lipid peroxidation and DNA damage failed to show indications of toxic effects from lead. The biomagnification factor of cadmium (hepatic concentration/soil concentration) at a site with a strongly acid soil was 44 times the average of the biomagnification factors at two sites with slightly alkaline soils. The elevated concentrations of cadmium in the mice did not cause observable toxicity, but were associated with about a 50% decrease in expected tissue lead concentrations and greater ALAD activity compared to the activity at the reference site. Lead was associated with a decrease in concentrations of hepatic glutathione and thiols, whereas cadmium was associated with an increase. In addition, to support risk assessment efforts, we developed linear regression models relating both tissue lead dosages (based on a previously published a laboratory study) and tissue lead concentrations in Peromyscus to soil lead concentrations.

Biomarker responses of Peromyscus leucopus exposed to lead and cadmium in the Southeast Missouri Lead Mining District.

PubMed

Beyer, W Nelson; Casteel, Stan W; Friedrichs, Kristen R; Gramlich, Eric; Houseright, Ruth A; Nichols, John R; Karouna-Renier, Natalie K; Kim, Dae Young; Rangen, Kathleen L; Rattner, Barnett A; Schultz, Sandra L

2018-01-29

Biomarker responses and histopathological lesions have been documented in laboratory mammals exposed to elevated concentrations of lead and cadmium. The exposure of white-footed mice (Peromyscus leucopus) to these metals and the potential associated toxic effects were examined at three contaminated sites in the Southeast Missouri Lead Mining District and at a reference site in MO, USA. Mice from the contaminated sites showed evidence of oxidative stress and reduced activity of red blood cell δ-aminolevulinic acid dehydratase (ALAD). Histological examinations of the liver and kidney, cytologic examination of blood smears, and biomarkers of lipid peroxidation and DNA damage failed to show indications of toxic effects from lead. The biomagnification factor of cadmium (hepatic concentration/soil concentration) at a site with a strongly acid soil was 44 times the average of the biomagnification factors at two sites with slightly alkaline soils. The elevated concentrations of cadmium in the mice did not cause observable toxicity, but were associated with about a 50% decrease in expected tissue lead concentrations and greater ALAD activity compared to the activity at the reference site. Lead was associated with a decrease in concentrations of hepatic glutathione and thiols, whereas cadmium was associated with an increase. In addition, to support risk assessment efforts, we developed linear regression models relating both tissue lead dosages (based on a previously published a laboratory study) and tissue lead concentrations in Peromyscus to soil lead concentrations.

Air Pollution and Insulin Resistance: Do All Roads Lead to Rome?

EPA Science Inventory

The World Health Organization estimates that worldwide in 2012, nearly 7 million deaths occurred prematurely due to air pollution (1). In addition to respiratory and cardiovascular diseases, air pollution exposure is also linked to increased incidence of diabetes (2). Notably, th...

The chain of cross-contamination: link-by-link.

PubMed

Schwartz, Jeanne

2002-01-01

Conscious efforts must be made to break the chain of cross-contamination--link-by-link. Pay attention to detail Avoid being careless Avoid touching objects while wearing soiled gloves Frequently wash hands (15-second hand washing) to remove pathogens--before and after gloving, and before handling food or drink Wear all PPE, and change accordingly.

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.

Evaluation of desialylation during 2-amino benzamide labeling of asparagine-linked oligosaccharides.

PubMed

Aich, Udayananth; Hurum, Deanna C; Basumallick, Lipika; Rao, Srinivasa; Pohl, Chris; Rohrer, Jeffrey S; Kandzia, Sebastian

2014-08-01

Labeling of released asparagine-linked (N-linked) oligosaccharides from glycoproteins is commonly performed to aid in the separation and detection of the oligosaccharide. Of the many available oligosaccharide labels, 2-amino benzamide (2-AB) is a popular choice for providing a fluorescent product. The derivatization conditions can potentially lead to oligosaccharide desialylation. This work evaluated the extent of sialic acid loss during 2-AB labeling of N-linked oligosaccharides released from bovine fetuin, polyclonal human serum immunoglobulin G (IgG), and human α1-acid glycoprotein (AGP) as well as of sialylated oligosaccharide reference standards and found that for more highly sialylated oligosaccharides the loss is greater than the <2% value commonly cited. Manufacturers of glycoprotein biotherapeutics need to produce products with a consistent state of sialylation and, therefore, require an accurate assessment of glycoprotein sialylation. Copyright © 2014 Elsevier Inc. All rights reserved.

Molecular and clinical studies of X-linked deafness among Pakistani families.

PubMed

Waryah, Ali M; Ahmed, Zubair M; Bhinder, Munir A; Binder, Munir A; Choo, Daniel I; Sisk, Robert A; Shahzad, Mohsin; Khan, Shaheen N; Friedman, Thomas B; Riazuddin, Sheikh; Riazuddin, Saima

2011-07-01

There are 68 sex-linked syndromes that include hearing loss as one feature and five sex-linked nonsyndromic deafness loci listed in the OMIM database. The possibility of additional such sex-linked loci was explored by ascertaining three unrelated Pakistani families (PKDF536, PKDF1132 and PKDF740) segregating X-linked recessive deafness. Sequence analysis of POU3F4 (DFN3) in affected members of families PKDF536 and PKDF1132 revealed two novel nonsense mutations, p.Q136X and p.W114X, respectively. Family PKDF740 is segregating congenital blindness, mild-to-profound progressive hearing loss that is characteristic of Norrie disease (MIM#310600). Sequence analysis of NDP among affected members of this family revealed a novel single nucleotide deletion c.49delG causing a frameshift and premature truncation (p.V17fsX1) of the encoded protein. These mutations were not found in 150 normal DNA samples. Identification of pathogenic alleles causing X-linked recessive deafness will improve molecular diagnosis, genetic counseling and molecular epidemiology of hearing loss among Pakistanis.

Molecular and Clinical Studies of X-linked Deafness Among Pakistani Families

PubMed Central

Waryah, Ali M.; Ahmed, Zubair M.; Choo, Daniel I.; Sisk, Robert A.; Binder, Munir A.; Shahzad, Mohsin; Khan, Shaheen N.; Friedman, Thomas B.; Riazuddin, Sheikh; Riazuddin, Saima

2011-01-01

There are 68 sex-linked syndromes that include hearing loss as one feature and five sex-linked nonsyndromic deafness loci listed in the OMIM database. The possibility of additional such sex-linked loci was explored by ascertaining three unrelated Pakistani families (PKDF536, PKDF1132, PKDF740) segregating X-linked recessive deafness. Sequence analysis of POU3F4 (DFN3) in affected members of families PKDF536 and PKDF1132 revealed two novel nonsense mutations, p.Q136X and p.W114X, respectively. Family PKDF740 is segregating congenital blindness, mild to profound progressive hearing loss that is characteristic of Norrie disease (MIM#310600). Sequence analysis of NDP among affected members of this family revealed a novel single nucleotide deletion c.49delG causing a frameshift and premature truncation (p.V17fsX1) of the encoded protein. These mutations were not found in 150 normal DNA samples. Identification of pathogenic alleles causing X-linked recessive deafness will improve molecular diagnosis, genetic counseling, and molecular epidemiology of hearing loss among Pakistanis. PMID:21633365

Leading for Equity: The Pursuit of Excellence in the Montgomery County Public Schools

ERIC Educational Resources Information Center

Childress, Stacey M.; Doyle, Denis P.; Thomas, David A.

2009-01-01

"Leading for Equity" tells the compelling story of the Montgomery County (Maryland) Public Schools and its transformation--in less than a decade--into a system committed to breaking the links between race and class and academic achievement. In chapters organized around six core themes, the authors lay out the essential elements of MCPS's…

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Tin-coated lead foil capsules for wine bottles... Substances Prohibited From Indirect Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Tin-coated lead foil capsules for wine bottles. 189... Substances Prohibited From Indirect Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Tin-coated lead foil capsules for wine bottles... Substances Prohibited From Indirect Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Tin-coated lead foil capsules for wine bottles... Substances Prohibited From Indirect Addition to Human Food Through Food-Contact Surfaces § 189.301 Tin-coated lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

Stable radio frequency transfer in 114 km urban optical fiber link.

PubMed

Kumagai, Motohiro; Fujieda, Miho; Nagano, Shigeo; Hosokawa, Mizuhiko

2009-10-01

An rf dissemination system using an optical fiber link has been developed. The phase noise induced during optical fiber transmission has been successfully cancelled using what we believe to be a novel fiber-noise compensation system with a combination of electrical and optical compensations. We have performed rf transfer in a 114 km urban telecom fiber link in Tokyo with a transfer stability of 10(-18) level at an averaging time of 1 day. Additionally, a high degree of continuous operation robustness has been confirmed.

Effect of Link Flexibility on tip position of a single link robotic arm

NASA Astrophysics Data System (ADS)

Madhusudan Raju, E.; Siva Rama Krishna, L.; Mouli, Y. Sharath Chandra; Nageswara Rao, V.

2015-12-01

The flexible robots are widely used in space applications due to their quick response, lower energy consumption, lower overall mass and operation at high speed compared to conventional industrial rigid link robots. These robots are inherently flexible, so that the kinematics of flexible robots can't be solved with rigid body assumptions. The flexibility in links and joints affects end-point positioning accuracy of the robot. It is important to model the link kinematics with precision which in turn simplifies modelling of dynamics of flexible robots. The main objective of this paper is to evaluate the effect of link flexibility on a tip position of a single link robotic arm for a given motion. The joint is assumed to be rigid and only link flexibility is considered. The kinematics of flexible link problem is evaluated by Assumed Modes Method (AMM) using MAT LAB Programming. To evaluate the effect of link flexibility (with and without payload) of robotic arm, the normalized tip deviation is found for flexible link with respect to a rigid link. Finally, the limiting inertia for payload mass is found if the allowable tip deviation is 5%.

Photoregulating RNA digestion using azobenzene linked dumbbell antisense oligodeoxynucleotides.

PubMed

Wu, Li; He, Yujian; Tang, Xinjing

2015-06-17

Introduction of 4,4'-bis(hydroxymethyl)-azobenzene (azo) to dumbbell hairpin oligonucleotides at the loop position was able to reversibly control the stability of the whole hairpin structure via UV or visible light irradiation. Here, we designed and synthesized a series of azobenzene linked dumbbell antisense oligodeoxynucleotides (asODNs) containing two terminal hairpins that are composed of an asODN and a short inhibitory sense strand. Thermal melting studies of these azobenzene linked dumbbell asODNs indicated that efficient trans to cis photoisomerization of azobenzene moieties induced large difference in thermal stability (ΔTm = 12.1-21.3 °C). In addition, photomodulation of their RNA binding abilities and RNA digestion by RNase H was investigated. The trans-azobenzene linked asODNs with the optimized base pairs between asODN strands and inhibitory sense strands could only bind few percentage of the target RNA, while it was able to recover their binding to the target RNA and degrade it by RNase H after light irradiation. Upon optimization, it is promising to use these azobenzene linked asODNs for reversible spatial and temporal regulation of antisense activities based on both steric binding and RNA digestion by RNase H.

Durability of implanted electrodes and leads in an upper-limb neuroprosthesis.

PubMed

Kilgore, Kevin L; Peckham, P Hunter; Keith, Michael W; Montague, Fred W; Hart, Ronald L; Gazdik, Martha M; Bryden, Anne M; Snyder, Scott A; Stage, Thomas G

2003-01-01

Implanted neuroprosthetic systems have been successfully used to provide upper-limb function for over 16 years. A critical aspect of these implanted systems is the safety, stability, and-reliability of the stimulating electrodes and leads. These components are (1) the stimulating electrode itself, (2) the electrode lead, and (3) the lead-to-device connector. A failure in any of these components causes the direct loss of the capability to activate a muscle consistently, usually resulting in a decrement in the function provided by the neuroprosthesis. Our results indicate that the electrode, lead, and connector system are extremely durable. We analyzed 238 electrodes that have been implanted as part of an upper-limb neuroprosthesis. Each electrode had been implanted at least 3 years, with a maximum implantation time of over 16 years. Only three electrode-lead failures and one electrode infection occurred, for a survival rate of almost 99 percent. Electrode threshold measurements indicate that the electrode response is stable over time, with no evidence of electrode migration or continual encapsulation in any of the electrodes studied. These results have an impact on the design of implantable neuroprosthetic systems. The electrode-lead component of these systems should no longer be considered a weak technological link.

21 CFR 73.2396 - Lead acetate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula Pb... cosmetics intended for coloring hair on the scalp only, subject to the following restrictions: (1) The... mustaches, eyelashes, eyebrows, or hair on parts of the body other than the scalp. (d) Labeling requirements...

21 CFR 73.2396 - Lead acetate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula Pb... cosmetics intended for coloring hair on the scalp only, subject to the following restrictions: (1) The... mustaches, eyelashes, eyebrows, or hair on parts of the body other than the scalp. (d) Labeling requirements...

21 CFR 73.2396 - Lead acetate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula Pb... cosmetics intended for coloring hair on the scalp only, subject to the following restrictions: (1) The... mustaches, eyelashes, eyebrows, or hair on parts of the body other than the scalp. (d) Labeling requirements...

21 CFR 73.2396 - Lead acetate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula Pb... cosmetics intended for coloring hair on the scalp only, subject to the following restrictions: (1) The... mustaches, eyelashes, eyebrows, or hair on parts of the body other than the scalp. (d) Labeling requirements...

21 CFR 73.2396 - Lead acetate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... acetate is the trihydrate of lead (2+) salt of acetic acid. The color additive has the chemical formula Pb... cosmetics intended for coloring hair on the scalp only, subject to the following restrictions: (1) The... mustaches, eyelashes, eyebrows, or hair on parts of the body other than the scalp. (d) Labeling requirements...

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

Global approach to reducing lead exposure and poisoning.

PubMed

Meyer, Pamela A; Brown, Mary Jean; Falk, Henry

2008-01-01

Lead poisoning is an important environmental disease that can have life-long adverse health effects. Most susceptible are children, and most commonly exposed are those who are poor and live in developing countries. Studies of children's blood-lead levels (BLLs) are showing cognitive impairment at increasingly lower BLLs. Lead is dangerous at all levels in children. The sources of lead exposure vary among and within countries depending on past and current uses. Sources of lead may be from historic contamination, recycling old lead products, or from manufacturing new products. In all countries that have banned leaded gasoline, average population BLLs have declined rapidly. In many developing countries where leaded gasoline is no longer used, many children and workers are exposed to fugitive emissions and mining wastes. Unexpected lead threats, such as improper disposal of electronics and children's toys contaminated with lead, continue to emerge. The only medical treatment available is chelation, which can save lives of persons with very high BLLs. However, chelating drugs are not always available in developing countries and have limited value in reducing the sequelae of chronic low dose lead exposure. Therefore, the best approach is to prevent exposure to lead. Because a key strategy for preventing lead poisoning is to identify and control or eliminate lead sources, this article highlights several major sources of lead poisoning worldwide. In addition, we recommend three primary prevention strategies for lead poisoning: identify sources, eliminate or control sources, and monitor environmental exposures and hazards.

Primary prevention of pediatric lead exposure requires new approaches to transfusion screening.

PubMed

Gehrie, Eric; Keiser, Amaris; Dawling, Sheila; Travis, James; Strathmann, Frederick G; Booth, Garrett S

2013-09-01

To facilitate further assessment of transfusion-associated lead exposure by designing a procedure to test packed red blood cells (pRBCs) prepared for transfusion. The relationship between pRBCs and whole blood lead concentration was investigated in 27 samples using a modified clinical assay. Lead concentrations were measured in 100 pRBC units. Our sample preparation method demonstrated a correlation between whole blood lead and pRBC lead concentrations (R(2) = 0.82). In addition, all 100 pRBC units tested had detectable lead levels. The median pRBC lead concentration was 0.8 μg/dL, with an SD of 0.8 μg/dL and a range of 0.2-4.1 μg/dL. In addition, after only a few days of storage, approximately 25% of whole blood lead was found in the supernatant plasma. Transfusion of pRBCs is a source of lead exposure. Here we report the quantification of lead concentration in pRBCs. We found a >20-fold range of lead concentrations in the samples tested. Pretransfusion testing of pRBC units according to our proposed approach or donor screening of whole blood lead and selection of below-average units for transfusion to children would diminish an easily overlooked source of pediatric lead exposure. Copyright © 2013 Mosby, Inc. All rights reserved.

Leptin Metabolically Licenses T Cells for Activation to Link Nutrition and Immunity

PubMed Central