Science.gov

Sample records for 7-8 times higher

  1. Progress in reducing aerodynamic drag for higher efficiency of heavy duty trucks (class 7-8)

    SciTech Connect

    Brady, M; Browand, F; Hammache, M; Heineck, J T; Leonard, A; McCallen, R; Ross, J; Rutledge, W; Salari, K; Storms, B

    1999-04-01

    This paper describes research and development for reducing the aerodynamic drag of heavy vehicles by demonstrating new approaches for the numerical simulation and analysis of aerodynamic flow. In addition, greater use of newly developed computational tools holds promise for reducing the number of prototype tests, for cutting manufacturing costs, and for reducing overall time to market. Experimental verification and validation of new computational fluid dynamics methods are also an important part of this approach. Experiments on a model of an integrated tractor-trailer are underway at NASA Ames Research Center and the University of Southern California. Companion computer simulations are being performed by Sandia National Laboratories, Lawrence Livermore National Laboratory, and California Institute of Technology using state-of-the-art techniques, with the intention of implementing more complex methods in the future.

  2. Progress in Reducing Aerodynamic Drag for Higher Efficiency of Heavy Duty Trucks (Class 7-8)

    SciTech Connect

    Rose McCallen; Richard Couch; Juliana Hsu; Fred Browand; Mustapha Hammache; Anthony Leonard; Mark Brady; Kambiz Salari; Walter Rutledge; James Ross; Bruce Storms; J.T. Heineck; David Driver; James Bell; Gregory Zilliac

    1999-12-31

    This paper describes research and development for reducing the aerodynamic drag of heavy vehicles by demonstrating new approaches for the numerical simulation and analysis of aerodynamic flow. In addition, greater use of newly developed computational tools holds promise for reducing the number of prototype tests, for cutting manufacturing costs, and for reducing overall time to market. Experimental verification and validation of new computational fluid dynamics methods are also an important part of this approach. Experiments on a model of an integrated tractor-trailer are underway at NASA Ames Research Center and the University of Southern California. Companion computer simulations are being performed by Sandia National Laboratories, Lawrence Livermore National Laboratory, and California Institute of Technology using state-of-the-art techniques, with the intention of implementing more complex methods in the future.

  3. 41 CFR 302-7.8 - Is there a time limit for the temporary storage of an authorized HHG shipment?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 4 2011-07-01 2011-07-01 false Is there a time limit for the temporary storage of an authorized HHG shipment? 302-7.8 Section 302-7.8 Public Contracts and... PROPERTY 7-TRANSPORTATION AND TEMPORARY STORAGE OF HOUSEHOLD GOODS AND PROFESSIONAL BOOKS, PAPERS,...

  4. GPS constraints on M 7-8 earthquake recurrence times for the New Madrid seismic zone

    USGS Publications Warehouse

    Stuart, W.D.

    2001-01-01

    Newman et al. (1999) estimate the time interval between the 1811-1812 earthquake sequence near New Madrid, Missouri and a future similar sequence to be at least 2,500 years, an interval significantly longer than other recently published estimates. To calculate the recurrence time, they assume that slip on a vertical half-plane at depth contributes to the current interseismic motion of GPS benchmarks. Compared to other plausible fault models, the half-plane model gives nearly the maximum rate of ground motion for the same interseismic slip rate. Alternative models with smaller interseismic fault slip area can satisfy the present GPS data by having higher slip rate and thus can have earthquake recurrence times much less than 2,500 years.

  5. 41 CFR 302-7.8 - Is there a time limit for the temporary storage of an authorized HHG shipment?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for the temporary storage of an authorized HHG shipment? 302-7.8 Section 302-7.8 Public Contracts and Property Management Federal Travel Regulation System RELOCATION ALLOWANCES TRANSPORTATION AND STORAGE OF PROPERTY 7-TRANSPORTATION AND TEMPORARY STORAGE OF HOUSEHOLD GOODS AND PROFESSIONAL BOOKS, PAPERS,...

  6. Time scales of the European surface air temperature variability: The role of the 7-8 year cycle

    NASA Astrophysics Data System (ADS)

    Jajcay, Nikola; Hlinka, Jaroslav; Kravtsov, Sergey; Tsonis, Anastasios A.; Paluš, Milan

    2016-01-01

    Air temperature variability on different time scales exhibits recurring patterns and quasi-oscillatory phenomena. Climate oscillations with the period about 7-8 years have been observed in many instrumental records in Europe. Although these oscillations are weak if considering their amplitude, they might have nonnegligible influence on temperature variability on shorter time scales due to cross-scale interactions recently observed by Paluš (2014). In order to quantify the cross-scale influence, we propose a simple conditional mean approach which estimates the effect of the cycle with the period close to 8 years on the amplitude of the annual cycle in surface air temperature (SAT) in the range 0.7-1.4°C and the effect on the overall variability of the SAT anomalies (SATA) leads to the changes 1.5-1.7°C in the annual SATA means. The strongest effect in the winter SATA means reaches 4-5°C in central European station and reanalysis data.

  7. Real-Time seismic waveforms monitoring with BeiDou Navigation Satellite System (BDS) observations for the 2015 Mw 7.8 Nepal earthquake

    NASA Astrophysics Data System (ADS)

    Geng, T.

    2015-12-01

    Nowadays more and more high-rate Global Navigation Satellite Systems (GNSS) data become available in real time, which provide more opportunities to monitor the seismic waveforms. China's GNSS, BeiDou Navigation Satellite System (BDS), has already satisfied the requirement of stand-alone precise positioning in Asia-Pacific region with 14 in-orbit satellites, which promisingly suggests that BDS could be applied to the high-precision earthquake monitoring as GPS. In the present paper, real-time monitoring of seismic waveforms using BDS measurements is assessed. We investigate a so-called "variometric" approach to measure real-time seismic waveforms with high-rate BDS observations. This approach is based on time difference technique and standard broadcast products which are routinely available in real time. The 1HZ BDS data recorded by Beidou Experimental Tracking Stations (BETS) during the 2015 Mw 7.8 Nepal earthquake is analyzed. The results indicate that the accuracies of velocity estimation from BDS are 2-3 mm/s in horizontal components and 8-9 mm/s in vertical component, respectively, which are consistent with GPS. The seismic velocity waveforms during earthquake show good agreement between BDS and GPS. Moreover, the displacement waveforms is reconstructed by an integration of velocity time series with trend removal. The displacement waveforms with the accuracy of 1-2 cm are derived by comparing with post-processing GPS precise point positioning (PPP).

  8. Real-time capture of seismic waves using high-rate multi-GNSS observations: Application to the 2015 Mw 7.8 Nepal earthquake

    NASA Astrophysics Data System (ADS)

    Geng, Tao; Xie, Xin; Fang, Rongxin; Su, Xing; Zhao, Qile; Liu, Gang; Li, Heng; Shi, Chuang; Liu, Jingnan

    2016-01-01

    The variometric approach is investigated to measure real-time seismic waves induced by the 2015 Mw 7.8 Nepal earthquake with high-rate multi-GNSS observations, especially with the contribution of newly available BDS. The velocity estimation using GPS + BDS shows an additional improvement of around 20% with respect to GPS-only solutions. We also reconstruct displacements by integrating GNSS-derived velocities after a linear trend removal (IGV). The displacement waveforms with accuracy of better than 5 cm are derived when postprocessed GPS precise point positioning results are used as ground truth, even if those stations have strong ground motions and static offsets of up to 1-2 m. GNSS-derived velocity and displacement waveforms with the variometric approach are in good agreement with results from strong motion data. We therefore conclude that it is feasible to capture real-time seismic waves with multi-GNSS observations using the IGV-enhanced variometric approach, which has critical implications for earthquake early warning, tsunami forecasting, and rapid hazard assessment.

  9. Real-Time Science on Social Media: The Example of Twitter in the Minutes, Hours, Days after the 2015 M7.8 Nepal Earthquake

    NASA Astrophysics Data System (ADS)

    Lomax, A.; Bossu, R.; Mazet-Roux, G.

    2015-12-01

    Scientific information on disasters such as earthquakes typically comes firstly from official organizations, news reports and interviews with experts, and later from scientific presentations and peer-reviewed articles. With the advent of the Internet and social media, this information is available in real-time from automated systems and within a dynamic, collaborative interaction between scientific experts, responders and the public. After the 2015 M7.8 Nepal earthquake, Twitter Tweets from earth scientists* included information, analysis, commentary and discussion on earthquake parameters (location, size, mechanism, rupture extent, high-frequency radiation, …), earthquake effects (distribution of felt shaking and damage, triggered seismicity, landslides, …), earthquake rumors (e.g. the imminence of a larger event) and other earthquake information and observations (aftershock forecasts, statistics and maps, source and regional tectonics, seismograms, GPS, InSAR, photos/videos, …).In the future (while taking into account security, false or erroneous information and identity verification), collaborative, real-time science on social media after a disaster will give earlier and better scientific understanding and dissemination of public information, and enable improved emergency response and disaster management.* A sample of scientific Tweets after the 2015 Nepal earthquake: In the first minutes: "mb5.9 Mwp7.4 earthquake Nepal 2015.04.25-06:11:25UTC", "Major earthquake shakes Nepal 8 min ago", "Epicenter between Pokhara and Kathmandu", "Major earthquake shakes Nepal 18 min ago. Effects derived from witnesses' reports". In the first hour: "shallow thrust faulting to North under Himalayas", "a very large and shallow event ... Mw7.6-7.7", "aftershocks extend east and south of Kathmandu, so likely ruptured beneath city", "Valley-blocking landslides must be a very real worry". In the first day: "M7.8 earthquake in Nepal 2hr ago: destructive in Kathmandu Valley and

  10. Fungal oxidation of benzo(a)pyrene and (+-)-trans-7,8-dihydroxy-7,8-dihydrobenzo(a)pyrene

    SciTech Connect

    Cerniglia, C.E.; Gibson, D.T.

    1980-06-10

    The oxidation of benzo(a)pyrene by intact cells of the filamentous fungus Cunninghamella elegans resulted in the formation of a complex mixture of polar products which were detected by high pressure liquid chromatography. One of the products had a retention time on high pressure liquid chromatography identical with that given by (+-)-7..beta..,8a,9a,10..beta..-tetrahydroxy-7,8,9,10-tetrahydrobenzo(a)pyrene. In addition the absorption and mass spectra given by the fungal metabolite were consistent with this structural assignment. Incubation of (+-)-trans-7,8-dihydrobenzo(a)pyrene with cells of C. elegans led to the formation of the same tetrahydroxymetabolite. Two other products were formed that were identified as new phenolic derivatives of (+-)-trans-7,8-dihydroxy-7,8-dihydrobenzo(a)pyrene. Experiments with (+-)-trans (G-/sup 3/H) 7,8-dihydrobenzo(a)pyrene showed that over a 12-h period 4.0% of the dihydrodiol was converted to ethyl acetate-soluble products and 7..beta..,8..cap alpha..,9..cap alpha..,10..beta..-tetrahydroxy-7,8,9,10-tetrahdrobenzo(a)pyrene accounted for 25% of these metabolites. The results suggest that C. elegans can oxidize benzo(a)pyrene to either (+-)-7..beta..,8..cap alpha..-dihydroxy-9..cap alpha..,10..cap alpha..-epoxy-7,8,9,10-tetrahydroxy(a)pyrene or one of the two possible enantiomers of this compound. Under the experimental conditions, no evidence was found to suggest the formation of (+-)-7..beta..,8..cap alpha..-dihydroxy-9..beta..,10..beta..-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene. Thus, C. elegans has the ability to form at least one of the two diastereomeric benzo(a)pyrene 7,8-diol-9,10-epoxides that have been implicated as the ultimate carcinogenic forms of benzo(a)pyrene in higher organisms.

  11. Ultrafast photodynamics of pyrazine in the vacuum ultraviolet region studied by time-resolved photoelectron imaging using 7.8-eV pulses

    NASA Astrophysics Data System (ADS)

    Horio, Takuya; Suzuki, Yoshi-ichi; Suzuki, Toshinori

    2016-07-01

    The ultrafast electronic dynamics of pyrazine (C4N2H4) were studied by time-resolved photoelectron imaging (TRPEI) using the third (3ω, 4.7 eV) and fifth harmonics (5ω, 7.8 eV) of a femtosecond Ti:sapphire laser (ω). Although the photoionization signals due to the 5ω - 3ω and 3ω - 5ω pulse sequences overlapped near the time origin, we have successfully extracted their individual TRPEI signals using least squares fitting of the observed electron kinetic energy distributions. When the 5ω pulses preceded the 3ω pulses, the 5ω pulses predominantly excited the S4 (ππ*, 1B1u+1B2u) state. The photoionization signal from the S4 state generated by the time-delayed 3ω pulses was dominated by the D3(2B2g)←S4 photoionization process and exhibited a broad electron kinetic energy distribution, which rapidly downshifted in energy within 100 fs. Also observed were the photoionization signals for the 3s, 3pz, and 3py members of the Rydberg series converging to D0(2Ag). The Rydberg signals appeared immediately within our instrumental time resolution of 27 fs, indicating that these states are directly photoexcited from the ground state or populated from S4 within 27 fs. The 3s, 3pz, and 3py states exhibited single exponential decay with lifetimes of 94 ± 2, 89 ± 2, and 58 ± 1 fs, respectively. With the reverse pulse sequence of 3ω - 5ω, the ultrafast internal conversion (IC) from S2(ππ*) to S1(nπ*) was observed. The decay associated spectrum of S2 exhibited multiple bands ascribed to D0, D1, and D3, in agreement with the 3ω-pump and 6ω-probe experiment described in our preceding paper [T. Horio et al., J. Chem. Phys. 145, 044306 (2016)]. The electron kinetic energy and angular distributions from S1 populated by IC from S2 are also discussed.

  12. The Renaissance. Grade 7 Model Lesson for Standard 7.8. World History and Geography: Medieval and Early Modern Times. California History-Social Science Course Models.

    ERIC Educational Resources Information Center

    Zachlod, Michelle, Ed.

    California State Standard 7.8 is delineated in the following manner: "Students analyze the origins, accomplishments, and diffusion of the Renaissance," in terms of the way in which the revival of classical learning and the arts affected a new interest in humanism; the importance of Florence in the early stages of the Renaissance and the growth of…

  13. Higher Education for Our Time

    ERIC Educational Resources Information Center

    Burnett, Dana D.; Collins, Natalia D.

    2010-01-01

    Public higher education is currently experiencing a decline in financial support from state governments, an acceleration of enrollment growth, and a shift from a transformational to a transactional student relationship. Private institutions are also struggling with increasing operational costs, and decreases in revenue from endowments and…

  14. Part Time Study in Higher Education.

    ERIC Educational Resources Information Center

    Neville, Colin

    This document, which is intended for adults considering enrolling in part-time study in higher education, examines the objectives and experiences of adults who have pursued part-time study in higher education in the United Kingdom. The following reasons why adults return to higher education are discussed: personal development; self-fulfillment;…

  15. Sleep Disorders 6 Times Higher Among Veterans

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_159985.html Sleep Disorders 6 Times Higher Among Veterans Post-traumatic ... 20, 2016 WEDNESDAY, July 20, 2016 (HealthDay News) -- Sleep disorders are six times more likely among American ...

  16. 7 CFR 7.8 - Conduct of community committee elections.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Conduct of community committee elections. 7.8 Section... STABILIZATION AND CONSERVATION STATE, COUNTY AND COMMUNITY COMMITTEES § 7.8 Conduct of community committee elections. (a) The county committee serving at the time shall be responsible for the conduct of...

  17. 7 CFR 7.8 - Conduct of community committee elections.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Conduct of community committee elections. 7.8 Section... STABILIZATION AND CONSERVATION STATE, COUNTY AND COMMUNITY COMMITTEES § 7.8 Conduct of community committee elections. (a) The county committee serving at the time shall be responsible for the conduct of...

  18. 49 CFR 7.8 - Copies

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Copies 7.8 Section 7.8 Transportation Office of the Secretary of Transportation PUBLIC AVAILABILITY OF INFORMATION Information Required To Be Made Public by DOT § 7.8 Copies Copies of any material covered by this subpart that is not published...

  19. Strategies for Hard Times in Higher Education.

    ERIC Educational Resources Information Center

    Desfosses, Louis R.

    1996-01-01

    Planning and management strategies used in the private sector have practical applications for higher education in a period of systemic and organizational stress. Promising strategies include organizational delayering; employee empowerment; boundless thinking, problem-solving teams; accelerated processes; quality management and improvement; and…

  20. Identification of 5,6,7,8-tetrahydropterin and 5,6,7,8-tetrahydrobiopterin in Drosophila melanogaster.

    PubMed

    Guillamón, J J; Ferré, J

    1988-04-15

    Using reversed-phase high-performance liquid chromatography with electrochemical detection we have demonstrated the occurrence of 5,6,7,8-tetrahydropterin and 5,6,7,8-tetrahydrobiopterin in Drosophila melanogaster. The former is the first time that has been detected in vivo. The identification has been based on the retention times, hydrodinamic voltagrams and the differential concentration in three strains of Drosophila melanogaster. Compared to the wild type, the Punch2 mutant has diminished levels of both pteridines, whereas Henna-recessive3 lacks completely tetrahydropterin and has increased levels of tetrahydrobiopterin, as expected according to their biochemical lesions.

  1. Higher Education: A Time for Triage?

    NASA Astrophysics Data System (ADS)

    Lagowski, J. J.

    1995-10-01

    Higher education faces unprecedented challenges. The confluence of changing economic and demographic tends; new patterns of federal and state spending; more explicit expectations by students and their families for affordable, accessible education; and heightened scrutiny by those who claim a legitimate interest in higher education is inescapably altering the environment in which this system operates. Higher education will never again be as it was before. Further, many believe that tinkering around the margins is no longer an adequate response to the new demands. Fundamental change is deemed necessary to meet the challenge of this melange of pressures. A number of commentators have observed that political and corporate America have responded to their challenges by instituting a fundamental restructuring of those institutions. The medical community is also in the midst of a similar basic restructuring of the health care delivery system in this country. Now its education's turn. People are questioning the historically expressed mission of higher education. They make the claim that we cost too much, spend carelessly, teach poorly, plan myopically, and when questioned, act defensively. Educational administrators, from department chairs up, are confronted with the task of simultaneously reforming and cutting back. They have no choice. They must establish politically sophisticated priority settings and effect a hard-nosed reallocation of resources in a social environment where competing public needs have equivalent--or stronger--emotional pulls. Triage in a medical context involves confronting an emergency in which the demand for attention far outstrips available assistance by establishing a sequence of care in which one key individual orchestrates the application of harsh priorities which have been designed to maximize the number of survivors. In recent years, the decisions that have been made in some centers of higher education bear a striking similarity. The literature

  2. Higher Education: A Time for Triage?

    NASA Astrophysics Data System (ADS)

    Lagowski, J. J.

    1995-10-01

    Higher education faces unprecedented challenges. The confluence of changing economic and demographic tends; new patterns of federal and state spending; more explicit expectations by students and their families for affordable, accessible education; and heightened scrutiny by those who claim a legitimate interest in higher education is inescapably altering the environment in which this system operates. Higher education will never again be as it was before. Further, many believe that tinkering around the margins is no longer an adequate response to the new demands. Fundamental change is deemed necessary to meet the challenge of this melange of pressures. A number of commentators have observed that political and corporate America have responded to their challenges by instituting a fundamental restructuring of those institutions. The medical community is also in the midst of a similar basic restructuring of the health care delivery system in this country. Now its education's turn. People are questioning the historically expressed mission of higher education. They make the claim that we cost too much, spend carelessly, teach poorly, plan myopically, and when questioned, act defensively. Educational administrators, from department chairs up, are confronted with the task of simultaneously reforming and cutting back. They have no choice. They must establish politically sophisticated priority settings and effect a hard-nosed reallocation of resources in a social environment where competing public needs have equivalent--or stronger--emotional pulls. Triage in a medical context involves confronting an emergency in which the demand for attention far outstrips available assistance by establishing a sequence of care in which one key individual orchestrates the application of harsh priorities which have been designed to maximize the number of survivors. In recent years, the decisions that have been made in some centers of higher education bear a striking similarity. The literature

  3. 7,8-Secolignans from the fruits of Schisandra neglecta.

    PubMed

    Wang, Huan; Yang, Juan-Xia; Lou, Jie; Liu, Gui-You; Li, Li-Mei; Sun, Han-Dong; Xiao, Wei-Lie; Hu, Qiu-Fen; Gao, Xue-Mei

    2015-01-01

    Two new 7,8-secolignans, neglectahenols E and F (1 and 2), together with four known 7,8-secolignans (3-6), were isolated from the fruits of Schisandra neglecta. The structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1-6 were tested for their anti-tobacco mosaic virus (anti-TMV) activities at the concentration of 20 μM. Compounds 1 and 6 showed high anti-TMV activities with inhibition rates of 38.2% and 32.7%, respectively. These rates are higher than that of a positive control. Compounds 2-5 also showed modest anti-TMV activities with inhibition rates in the range of 22.8-28.7%. These rates are close to that of a positive control.

  4. Representing 30 Years of Higher Education Change: UK Universities and the "Times Higher"

    ERIC Educational Resources Information Center

    Gewirtz, Sharon; Cribb, Alan

    2013-01-01

    This paper argues that the "Times Higher" provides a powerful tool for understanding the changing character of UK higher education (HE) and can usefully be seen as representative, and in some ways constitutive, of that changing character. Drawing on an analysis of a sample of stories from the "Times Higher," it documents the changing policy…

  5. Representing 30 Years of Higher Education Change: UK Universities and the "Times Higher"

    ERIC Educational Resources Information Center

    Gewirtz, Sharon; Cribb, Alan

    2013-01-01

    This paper argues that the "Times Higher" provides a powerful tool for understanding the changing character of UK higher education (HE) and can usefully be seen as representative, and in some ways constitutive, of that changing character. Drawing on an analysis of a sample of stories from the "Times Higher," it documents the…

  6. RDamage 6, 7, 8 & 9 Cassettes

    SciTech Connect

    Griego, Jeffrey R; Kaul, Ann

    2012-06-08

    The RDamage series of ten experiments is part of a long-term collaboration with RFNC/VNIIEF in pulsed power technology. These experiments use a cylindrical configuration to study spallation damage, which allows for a natural recollection of the damaged material under proper driving conditions and post-shot collection of the damaged target material for subsequent metallographic analysis. Dynamic insitu experimental velocimetry diagnostics are also employed. LANL is responsible for the design of the experimental load and velocimetry system. VNIIEF is responsible for the design and construction of the driving explosive magnetic generator. In the RDamage-0, -1 and -2 experiments, data was collected about failure initiation of a well-characterized material (aluminum) in a cylindrical geometry. The RDamage-3, -4 and -5 experiments produced data on the behavior of material recollected after damage from pressures in the damage initiation regime. Data on the behavior of material recollected after complete failure was collected in the RDamage-6, -7, -8 and -9 experiments. This presentation shows the evolution of the load assembly through the experimental series.

  7. Just in Time Research: Data Breaches in Higher Education

    ERIC Educational Resources Information Center

    Grama, Joanna

    2014-01-01

    This "Just in Time" research is in response to recent discussions on the EDUCAUSE Higher Education Information Security Council (HEISC) discussion list about data breaches in higher education. Using data from the Privacy Rights Clearinghouse, this research analyzes data breaches attributed to higher education. The results from this…

  8. 76 FR 24407 - Airworthiness Directives; General Electric Company CT7-8, CT7-8A, CT7-8A1, CT7-8E, and CT7-8F5...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-02

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; General Electric... proposed AD. ] Discussion We received four reports of General Electric Company (GE) CT7-8 series turboshaft... directive (AD): General Electric Company: Docket No. FAA-2011-0392; Directorate Identifier...

  9. 44 CFR 7.8 - Elementary and secondary schools.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 44 Emergency Management and Assistance 1 2011-10-01 2011-10-01 false Elementary and secondary schools. 7.8 Section 7.8 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY...) Nondiscrimination in FEMA-Assisted Programs-General § 7.8 Elementary and secondary schools. The requirements...

  10. 34 CFR 7.8 - Employee's right of appeal.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Employee's right of appeal. 7.8 Section 7.8 Education Office of the Secretary, Department of Education EMPLOYEE INVENTIONS § 7.8 Employee's right of appeal. An employee who is aggrieved by a determination of the Department may appeal to the Commissioner of...

  11. 10 CFR 7.8 - Charter filing requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Charter filing requirements. 7.8 Section 7.8 Energy NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEES § 7.8 Charter filing requirements. No advisory committee... Works of the United States Senate and the Committee on Energy and Commerce of the United States House...

  12. 10 CFR 7.8 - Charter filing requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Charter filing requirements. 7.8 Section 7.8 Energy NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEES § 7.8 Charter filing requirements. No advisory committee... Works of the United States Senate and the Committee on Energy and Commerce of the United States House...

  13. 10 CFR 7.8 - Charter filing requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Charter filing requirements. 7.8 Section 7.8 Energy NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEES § 7.8 Charter filing requirements. No advisory committee... Works of the United States Senate and the Committee on Energy and Commerce of the United States House...

  14. 10 CFR 7.8 - Charter filing requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Charter filing requirements. 7.8 Section 7.8 Energy NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEES § 7.8 Charter filing requirements. No advisory committee... Works of the United States Senate and the Committee on Energy and Commerce of the United States House...

  15. 10 CFR 7.8 - Charter filing requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Charter filing requirements. 7.8 Section 7.8 Energy NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEES § 7.8 Charter filing requirements. No advisory committee... Works of the United States Senate and the Committee on Energy and Commerce of the United States House...

  16. 4 CFR 7.8 - Services to employees.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 4 Accounts 1 2010-01-01 2010-01-01 false Services to employees. 7.8 Section 7.8 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM PERSONNEL RELATIONS AND SERVICES § 7.8 Services to... Management implementing regulations apply to Government Accountability Office employees....

  17. 45 CFR 7.8 - Employee's right of appeal.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Employee's right of appeal. 7.8 Section 7.8 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION EMPLOYEE INVENTIONS § 7.8 Employee's right of appeal. An employee who is aggrieved by a determination of the Department may appeal...

  18. 45 CFR 7.8 - Employee's right of appeal.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Employee's right of appeal. 7.8 Section 7.8 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION EMPLOYEE INVENTIONS § 7.8 Employee's right of appeal. An employee who is aggrieved by a determination of the Department may appeal...

  19. 34 CFR 7.8 - Employee's right of appeal.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 1 2011-07-01 2011-07-01 false Employee's right of appeal. 7.8 Section 7.8 Education Office of the Secretary, Department of Education EMPLOYEE INVENTIONS § 7.8 Employee's right of appeal. An employee who is aggrieved by a determination of the Department may appeal to the Commissioner of...

  20. 30 CFR 7.8 - Post-approval product audit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Post-approval product audit. 7.8 Section 7.8 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY General § 7.8 Post-approval product...

  1. 30 CFR 7.8 - Post-approval product audit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Post-approval product audit. 7.8 Section 7.8 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY General § 7.8 Post-approval product...

  2. 30 CFR 7.8 - Post-approval product audit.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Post-approval product audit. 7.8 Section 7.8 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY General § 7.8 Post-approval product...

  3. 30 CFR 7.8 - Post-approval product audit.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Post-approval product audit. 7.8 Section 7.8 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY General § 7.8 Post-approval product...

  4. 30 CFR 7.8 - Post-approval product audit.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Post-approval product audit. 7.8 Section 7.8 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY General § 7.8 Post-approval product...

  5. The Times Higher Education Ranking Product: Visualising Excellence through Media

    ERIC Educational Resources Information Center

    Stack, Michelle L.

    2013-01-01

    This paper will examine the Times Higher Education's (THE) World University Rankings as a corporate media product. A number of empirical studies have critiqued the methodology of the THE, yet individuals, Higher Education Institutions (HEIs) and governments continue to use them for decision-making. This paper analyses the influence of…

  6. Higher Education in Recessionary Times: A UK Colloquium

    ERIC Educational Resources Information Center

    Evans, Mary

    2010-01-01

    This article talks about a meeting on "Higher Education in Recessionary Times" on March 24, 2010, which was hosted by the Society for Higher Education Research Policy Network. Although the meeting did take place in the context of an expected General Election, and on budget day, there was a general sense on the day that whoever won the Election (or…

  7. Adopting Consumer Time: Potential Issues for Higher Education

    ERIC Educational Resources Information Center

    Gibbs, Paul

    2009-01-01

    Time and temporality have received little attention in the consumerism, marketing or, until recently, higher education literature. This paper attempts to compare the notions of timing implicit in education as "paideia" (transitional personal growth) with that implicit in consumerism and the marketing practices which foster it. This investigation…

  8. Does the Timing of Tracking Affect Higher Education Completion?

    ERIC Educational Resources Information Center

    van Elk, Roel; van der Steeg, Marc; Webbink, Dinand

    2011-01-01

    This paper investigates the effect of the timing of tracking on completion of higher education by exploiting unique variation from the Dutch education system. At the age of 12 Dutch students can enrol in tracked schools or in comprehensive schools. The comprehensive schools postpone enrolment into tracked classes by one or two years. OLS- and…

  9. Naked singularities in higher dimensional Vaidya space-times

    SciTech Connect

    Ghosh, S. G.; Dadhich, Naresh

    2001-08-15

    We investigate the end state of the gravitational collapse of a null fluid in higher-dimensional space-times. Both naked singularities and black holes are shown to be developing as the final outcome of the collapse. The naked singularity spectrum in a collapsing Vaidya region (4D) gets covered with the increase in dimensions and hence higher dimensions favor a black hole in comparison to a naked singularity. The cosmic censorship conjecture will be fully respected for a space of infinite dimension.

  10. Programming real-time executives in higher order language

    NASA Technical Reports Server (NTRS)

    Foudriat, E. C.

    1982-01-01

    Methods by which real-time executive programs can be implemented in a higher order language are discussed, using HAL/S and Path Pascal languages as program examples. Techniques are presented by which noncyclic tasks can readily be incorporated into the executive system. Situations are shown where the executive system can fail to meet its task scheduling and yet be able to recover either by rephasing the clock or stacking the information for later processing. The concept of deadline processing is shown to enable more effective mixing of time and information synchronized systems.

  11. Real-time operating systems at higher control

    SciTech Connect

    Jensen, E.D.

    1995-01-01

    Although virtually all development of real-time operating systems focuses on the lowest of the three traditional control levels, sheet economics demands higher level real-time OSs. Meeting this demand requires a major change in the mindset of the people who have been focusing on the lowest level of control. {open_quotes}These people are trying to deal with an elephant`s tail, but they don`t realize that there is an elephant attached to it.{close_quotes} For more than three decades, the historical real-time mindset, concepts and techniques have been driven by a particular pair of contexts. First is the application context, which can be characterized as {open_quotes}small, simple, centralized, static subsystems for low-level, sampled data, monitoring and first-order control.{close_quotes} Second is the hardware context, characterized by a scarcity of hardware resources due to size, weight, power and cost considerations. Both of these contexts are changing dramatically in ways that {open_quotes}have a significant impact on the concepts and techniques of real-time computing.{close_quotes} Hardware now offers much higher performance and the real-time domain is expanding upward in the application control hierarchy.

  12. Full-Time Students? Term-Time Employment among Higher Education Students in Ireland

    ERIC Educational Resources Information Center

    Darmody, Merike; Smyth, Emer

    2008-01-01

    A good deal of research has focused on part-time employment among full-time students in higher education. However, little attention has been paid to the way in which these patterns may reflect societally specific processes rather than universal trends. This paper examines ways in which the higher education system itself can influence variation in…

  13. Late-time acceleration in higher dimensional cosmology

    SciTech Connect

    Pahwa, Isha; Choudhury, Debajyoti; Seshadri, T.R. E-mail: debajyoti.choudhury@gmail.com

    2011-09-01

    We investigate late time acceleration of the universe in higher dimensional cosmology. The content in the universe is assumed to exert pressure which is different in the normal and extra dimensions. Cosmologically viable solutions are found to exist for simple forms of the equation of state. The parameters of the model are fixed by comparing the predictions with supernovae data. While observations stipulate that the matter exerts almost vanishing pressure in the normal dimensions, we assume that, in the extra dimensions, the equation of state is of the form P∝ρ{sup 1−γ}. For appropriate choice of parameters, a late time acceleration in the universe occurs with q{sub 0} and z{sub tr} being approximately -0.46 and 0.76 respectively.

  14. Neuroprotective Effects of 7, 8-dihydroxyflavone on Midbrain Dopaminergic Neurons in MPP+-treated Monkeys

    PubMed Central

    He, Jingjing; Xiang, Zheng; Zhu, Xiaoqing; Ai, Zongyong; Shen, Jingsong; Huang, Tianzhuang; Liu, Liegang; Ji, Weizhi; Li, Tianqing

    2016-01-01

    Parkinson’s disease (PD) is one common neurodegenerative disease caused by a significant loss of midbrain dopaminergic neurons. Previous reports showed that 7, 8- dihydroxyflavone (7, 8-DHF) as a potent TrkB agonist can mimic BDNF and play neuroprotective roles for mouse dopaminergic neurons. Nonetheless, the safety and neuroprotective effects are unclear in monkey models of PD. Here, we find that 7, 8-DHF could be absorbed and metabolized into 7-hydroxy-8-methoxyflavone through oral administration in monkeys. The half-life time of 7, 8-DHF in monkey plasma is about 4–8 hrs. Furthermore, these monkeys maintain health state throughout the course of seven-month treatments of 7, 8-DHF (30 mg/kg/day). Importantly, 7, 8-DHF treatments can prevent the progressive degeneration of midbrain dopaminergic neurons by attenuating neurotoxic effects of MPP+ and display strong neuroprotective effects in monkeys. Our study demonstrates that this promising small molecule may be transited into a clinical useful pharmacological agent. PMID:27731318

  15. Synaptic contacts impaired by styrene-7,8-oxide toxicity

    SciTech Connect

    Corsi, P. D'Aprile, A.; Nico, B.; Costa, G.L.; Assennato, G.

    2007-10-01

    Styrene-7,8-oxide (SO), a chemical compound widely used in industrial applications, is a potential hazard for humans, particularly in occupational settings. Neurobehavioral changes are consistently observed in occupationally exposed individuals and alterations of neurotransmitters associated with neuronal loss have been reported in animal models. Although the toxic effects of styrene have been extensively documented, the molecular mechanisms responsible for SO-induced neurotoxicity are still unclear. A possible dopamine-mediated effect of styrene neurotoxicity has been previously demonstrated, since styrene oxide alters dopamine neurotransmission in the brain. Thus, the present study hypothesizes that styrene neurotoxicity may involve synaptic contacts. Primary striatal neurons were exposed to styrene oxide at different concentrations (0.1-1 mM) for different time periods (8, 16, and 24 h) to evaluate the dose able to induce synaptic impairments. The expression of proteins crucial for synaptic transmission such as Synapsin, Synaptophysin, and RAC-1 were considered. The levels of Synaptophysin and RAC-1 decreased in a dose-dependent manner. Accordingly, morphological alterations, observed at the ultrastructural level, primarily involved the pre-synaptic compartment. In SO-exposed cultures, the biochemical cascade of caspases was activated affecting the cytoskeleton components as their target. Thus the impairments in synaptic contacts observed in SO-exposed cultures might reflect a primarily morphological alteration of neuronal cytoskeleton. In addition, our data support the hypothesis developed by previous authors of reactive oxygen species (ROS) initiating events of SO cytotoxicity.

  16. Pulse transmission transmitter including a higher order time derivate filter

    DOEpatents

    Dress, Jr., William B.; Smith, Stephen F.

    2003-09-23

    Systems and methods for pulse-transmission low-power communication modes are disclosed. A pulse transmission transmitter includes: a clock; a pseudorandom polynomial generator coupled to the clock, the pseudorandom polynomial generator having a polynomial load input; an exclusive-OR gate coupled to the pseudorandom polynomial generator, the exclusive-OR gate having a serial data input; a programmable delay circuit coupled to both the clock and the exclusive-OR gate; a pulse generator coupled to the programmable delay circuit; and a higher order time derivative filter coupled to the pulse generator. The systems and methods significantly reduce lower-frequency emissions from pulse transmission spread-spectrum communication modes, which reduces potentially harmful interference to existing radio frequency services and users and also simultaneously permit transmission of multiple data bits by utilizing specific pulse shapes.

  17. Measuring Stratigraphic Congruence Across Trees, Higher Taxa, and Time

    PubMed Central

    O'Connor, Anne; Wills, Matthew A.

    2016-01-01

    The congruence between the order of cladistic branching and the first appearance dates of fossil lineages can be quantified using a variety of indices. Good matching is a prerequisite for the accurate time calibration of trees, while the distribution of congruence indices across large samples of cladograms has underpinned claims about temporal and taxonomic patterns of completeness in the fossil record. The most widely used stratigraphic congruence indices are the stratigraphic consistency index (SCI), the modified Manhattan stratigraphic measure (MSM*), and the gap excess ratio (GER) (plus its derivatives; the topological GER and the modified GER). Many factors are believed to variously bias these indices, with several empirical and simulation studies addressing some subset of the putative interactions. This study combines both approaches to quantify the effects (on all five indices) of eight variables reasoned to constrain the distribution of possible values (the number of taxa, tree balance, tree resolution, range of first occurrence (FO) dates, center of gravity of FO dates, the variability of FO dates, percentage of extant taxa, and percentage of taxa with no fossil record). Our empirical data set comprised 647 published animal and plant cladograms spanning the entire Phanerozoic, and for these data we also modeled the effects of mean age of FOs (as a proxy for clade age), the taxonomic rank of the clade, and the higher taxonomic group to which it belonged. The center of gravity of FO dates had not been investigated hitherto, and this was found to correlate most strongly with some measures of stratigraphic congruence in our empirical study (top-heavy clades had better congruence). The modified GER was the index least susceptible to bias. We found significant differences across higher taxa for all indices; arthropods had lower congruence and tetrapods higher congruence. Stratigraphic congruence—however measured—also varied throughout the Phanerozoic

  18. Measuring Stratigraphic Congruence Across Trees, Higher Taxa, and Time.

    PubMed

    O'Connor, Anne; Wills, Matthew A

    2016-09-01

    The congruence between the order of cladistic branching and the first appearance dates of fossil lineages can be quantified using a variety of indices. Good matching is a prerequisite for the accurate time calibration of trees, while the distribution of congruence indices across large samples of cladograms has underpinned claims about temporal and taxonomic patterns of completeness in the fossil record. The most widely used stratigraphic congruence indices are the stratigraphic consistency index (SCI), the modified Manhattan stratigraphic measure (MSM*), and the gap excess ratio (GER) (plus its derivatives; the topological GER and the modified GER). Many factors are believed to variously bias these indices, with several empirical and simulation studies addressing some subset of the putative interactions. This study combines both approaches to quantify the effects (on all five indices) of eight variables reasoned to constrain the distribution of possible values (the number of taxa, tree balance, tree resolution, range of first occurrence (FO) dates, center of gravity of FO dates, the variability of FO dates, percentage of extant taxa, and percentage of taxa with no fossil record). Our empirical data set comprised 647 published animal and plant cladograms spanning the entire Phanerozoic, and for these data we also modeled the effects of mean age of FOs (as a proxy for clade age), the taxonomic rank of the clade, and the higher taxonomic group to which it belonged. The center of gravity of FO dates had not been investigated hitherto, and this was found to correlate most strongly with some measures of stratigraphic congruence in our empirical study (top-heavy clades had better congruence). The modified GER was the index least susceptible to bias. We found significant differences across higher taxa for all indices; arthropods had lower congruence and tetrapods higher congruence. Stratigraphic congruence-however measured-also varied throughout the Phanerozoic, reflecting

  19. Time-resolved spectral imaging: better photon economy, higher accuracy

    NASA Astrophysics Data System (ADS)

    Fereidouni, Farzad; Reitsma, Keimpe; Blab, Gerhard A.; Gerritsen, Hans C.

    2015-03-01

    Lifetime and spectral imaging are complementary techniques that offer a non-invasive solution for monitoring metabolic processes, identifying biochemical compounds, and characterizing their interactions in biological tissues, among other tasks. Newly developed instruments that perform time-resolved spectral imaging can provide even more information and reach higher sensitivity than either modality alone. Here we report a multispectral lifetime imaging system based on a field-programmable gate array (FPGA), capable of operating at high photon count rates (12 MHz) per spectral detection channel, and with time resolution of 200 ps. We performed error analyses to investigate the effect of gate width and spectral-channel width on the accuracy of estimated lifetimes and spectral widths. Temporal and spectral phasors were used for analysis of recorded data, and we demonstrated blind un-mixing of the fluorescent components using information from both modalities. Fractional intensities, spectra, and decay curves of components were extracted without need for prior information. We further tested this approach with fluorescently doubly-labeled DNA, and demonstrated its suitability for accurately estimating FRET efficiency in the presence of either non-interacting or interacting donor molecules.

  20. Galaxies at z~7-8: z850-Dropouts in the Hubble Ultra Deep Field

    NASA Astrophysics Data System (ADS)

    Bouwens, R. J.; Thompson, R. I.; Illingworth, G. D.; Franx, M.; van Dokkum, P. G.; Fan, X.; Dickinson, M. E.; Eisenstein, D. J.; Rieke, M. J.

    2004-12-01

    We have detected likely z~7-8 galaxies in the 144''×144'' Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) observations of the Hubble Ultra Deep Field. Objects are required to be >=3 σ detections in both NICMOS bands, J110 and H160. The selection criteria for this sample are (z850-J110)AB>0.8, (z850-J110)AB>0.66(J110-H160)AB+0.8, (J110-H160)AB<1.2 and no detection at less than 8500 Å. The five selected sources have total magnitudes H160,AB~27. Four of the five sources are quite blue compared to typical lower redshift dropout galaxies and are clustered within a 1 arcmin2 region. Because all five sources are near the limit of the NICMOS data, we have carefully evaluated their reality. Each of the candidates is visible in different splits of the data and a median stack. We analyzed several noise images and estimate the number of spurious sources to be 1+/-1. A search using an independent reduction of this same data set clearly revealed three of the five candidates and weakly detected a fourth candidate, suggesting that the contamination could be higher. For comparison with predictions from lower redshift samples, we take a conservative approach and adopt four z~7-8 galaxies as our sample. With the same detection criteria on simulated data sets, assuming no evolution from z~3.8, we predict 10 sources at z~7-8, or 14 if we use a more realistic (1+z)-1 size scaling. We estimate that the rest-frame continuum UV (~1800 Å) luminosity density at z~7.5 (integrated down to 0.3L*z=3) is just 0.20+0.12-0.08 times that found at z~3.8 (or 0.20+0.23-0.12 times this quantity including cosmic variance). Effectively this sets an upper limit on the luminosity density down to 0.3L*z=3 and is consistent with significant evolution at the bright end of the luminosity function from z~7.5 to 3.8. Even with the lower UV luminosity density at z~7.5, it appears that galaxies could still play an important role in reionization at these redshifts, although definitive measurements

  1. Advancing Knowledge in Higher Education: Universities in Turbulent Times

    ERIC Educational Resources Information Center

    Fitzgerald, Tanya, Ed.

    2014-01-01

    Over the last three decades, higher education institutions have experienced massive changes. In particular, institutions of higher education have been positioned as a means to contribute to the knowledge economy and gain a level of competitive advantage in the global marketplace. "Advancing Knowledge in Higher Education: Universities in…

  2. 12. VIEW OF SOUTH ELEVATIONS OF BUILDINGS 7, 8, 48, ...

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

    12. VIEW OF SOUTH ELEVATIONS OF BUILDINGS 7, 8, 48, 50, 40, 39 AND 33; BUILDING 7 AT EXTREME LEFT CENTER, BUILDING 8 LEFT CENTER FOREGROUND; BUILDING 48 LEFT CENTER BACKGROUND; BUILDING 50 CENTER FOREGROUND; BUILDING 40 CENTER BACKGROUND; BUILDING 39 RIGHT FOREGROUND; BUILDING 33 RIGHT BACKGROUND - Scovill Brass Works, 59 Mill Street, Waterbury, New Haven County, CT

  3. Career Activities in Science: Grades 7, 8, 9.

    ERIC Educational Resources Information Center

    Boise City Independent School District, ID.

    The career activities guide in science, part of an Idaho State Department of Vocational Education career exploration series for grades 7, 8, and 9, is designed as supplementary material to enrich the regular curriculum. Any one activity in the guide might be used without involving any other activities. The cross-referenced index indicates grades,…

  4. Creating Sacred Places for Students in Grades 7&8.

    ERIC Educational Resources Information Center

    Fox, Sandra J.

    This guide attempts to help teachers of American Indian students in grades 7-8 provide a culturally relevant education that takes place in the regular classroom, includes content related to Indian students' lives, makes students proud, expands to other experiences, and enhances learning. Creating sacred places means responding appropriately to…

  5. 2,3,7,8-Tetrachlorodibenzo-p-dioxin

    Integrated Risk Information System (IRIS)

    2,3,7,8 - Tetrachlorodibenzo - p - dioxin ( TCDD ) ; CASRN 1746 - 01 - 6 This document has been provided for review to EPA scientists , interagency reviewers from other federal agencies and White House offices , and the public , and peer reviewed by independent scientists external to EPA . Sections

  6. Career Activities in Mathematics: Grades 7, 8, 9.

    ERIC Educational Resources Information Center

    Boise City Independent School District, ID.

    The career activities guide in mathematics, part of an Idaho State Department of Vocational Education career exploration series for grades 7, 8, and 9, is designed as supplementary material to enrich the regular curriculum. Any one activity in the guide might be used without involving any other activities. The cross-referenced index indicates…

  7. California's "Gold Standard" for Higher Education Falls Upon Hard Times

    ERIC Educational Resources Information Center

    Keller, Josh

    2009-01-01

    Few documents in higher education have enjoyed the influence or longevity of the California Master Plan for Higher Education, the 1960 law that transformed the state's public colleges and served as a blueprint for public systems across the country. Even today, almost 50 years after it was written, the master plan retains a mythic status in…

  8. Time Management and Academic Achievement of Higher Secondary Students

    ERIC Educational Resources Information Center

    Cyril, A. Vences

    2015-01-01

    The only thing, which can't be changed by man, is time. One cannot get back time lost or gone Nothing can be substituted for time. Time management is actually self management. The skills that people need to manage others are the same skills that are required to manage themselves. The purpose of the present study was to explore the relation between…

  9. Crystal structures of two novel borate compounds MgInBO{sub 4} and MgIn{sub 7/8}B{sub 7/8}O{sub 29/8}

    SciTech Connect

    Li, H.K.; Cai, G.M.; Fan, J.J.; Jin, Z.P.; Zhou, T.T.; Chen, X.L.

    2013-06-15

    Two novel borate compounds MgInBO{sub 4} and MgIn{sub 7/8}B{sub 7/8}O{sub 29/8}, have been synthesized via solid-state reactions, and their crystal structures have been solved and refined from powder X-ray diffraction data. The compound MgInBO{sub 4}, which was obtained at 1190 °C, belongs to the warwickite family. It crystallizes in the Pnma space group (no. 62) with a=9.5443(1) Å, b=3.2771(1) Å, c=9.5228(1) Å, and Z=4. The fundamental building units are liner –Mg(In)O{sub 6}–[In(Mg)]{sub 2}O{sub 10}–Mg(In)O{sub 6}– chains and isolated BO{sub 3} triangles. The low-temperature phase, MgIn{sub 7/8}B{sub 7/8}O{sub 29/8}, whose crystal structure is solved ab initio by the charge-flipping method with standard chemical formula MgInBO{sub 4}, was prepared at 1080 °C. It crystallizes in the P12{sub 1}/n1 space group (no. 14) with a=17.0976(1) Å, b=3.2504(1) Å, c=5.3387(1) Å, β=96.0829(3)°, and Z=4. The structure of MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} contains [In(2)/Mg(2)]{sub 2}O{sub 10} groups, –MgO{sub 6}–InO{sub 6}– infinite ribbons and isolated BO{sub 3} triangles. The experiments and the differential thermal analysis (DTA) show the decompositions of MgInBO{sub 4} and MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} happen at about 1220 °C and 1180 °C, respectively. The comparative crystal chemistry from MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} to MgInBO{sub 4} has been discussed. Infrared spectra and UV–vis diffuse reflectance spectra of MgInBO{sub 4} and MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} were measured. - Graphical abstract: The structural transformation from the monoclinic MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} (P12{sub 1}/n1) to the orthorhombic MgInBO{sub 4} (Pnma). - Highlights: • Two novel borate compounds MgInBO{sub 4} and MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} have been synthesized via solid-state reactions for the first time. • The crystal structures of MgInBO{sub 4} and MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} have been solved and refined from powder X

  10. Gridded atmospheric emission inventory of 2,3,7,8-TCDD in China

    NASA Astrophysics Data System (ADS)

    Huang, Tao; Tian, Chongguo; Zhang, Kai; Gao, Hong; Li, Yi-Fan; Ma, Jianmin

    2015-05-01

    Establishment of the dioxins emission inventory has been considered as a crucial step toward risk assessment and elimination of dioxins contaminations. Based on a total dioxin emission inventory in China from different emission categories in 2004, this study created a gridded emission inventory of 2,3,7,8-TCDD, the most toxic congener in dioxins, in China in 2009 with a 1/4° longitude by 1/4° latitude resolution. It was estimated that annually total 371 ± 53 g (average ± standard deviation) of 2,3,7,8-TCDD was released into the atmosphere in 2009 over China, increasing approximately by 37% compared with its emission in 2004. Differing from most developed countries where municipal waste incinerations were regarded as a major atmospheric emission source, in China ferrous and non-ferrous metal production made the largest contribution to 2,3,7,8-TCDD air emission (138 ± 16 g), followed by waste incineration (109 ± 12 g), power and heating generation (62 ± 9 g), and production of mineral products (47 ± 8 g). The rest of sources contributed approximately 3% to the total 2,3,7,8-TCDD emission in 2009. Iron and steel industries are mainly located in Beijing-Tianjin-Hebei (BTH) and Yangtze River Delta (YRD) regions, whereas waste incinerators are mainly located in Pearl River Delta (PRD) region. Higher 2,3,7,8-TCDD emissions were found in these three regions. While the BTH, YRD, and PRD accounted for only about 4% of total land area of China, they contributed approximately 14%, 15%, and 5% to the total 2,3,7,8-TCDD emission in 2009 in China, respectively.

  11. SORPTION OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN FROM WATER BY SURFACE SOILS

    EPA Science Inventory

    The sorption of l4C-labeled 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) from water by two uncontaminated surface soils from the Times Beach, MO, area was evalu- ated by using batch shake testing. Sorption isotherm plots for the soil with the lower fraction organic carbon (f,) wer...

  12. Radioimmunoassay for quantitation of 2,3,7,8-tetrachlorodibenzofuran

    SciTech Connect

    Luster, M.I.; Albro, P.W.; Chae, K.; Lawson, L.D.; Corbett, J.T.; McKinney, J.D.

    1980-08-01

    A radioimmunoassay is described for the determination of 2,3,7,8-tetrachlorodibenzofuran (TCDF) in commercial preparations of polychlorinated biphenyls (PCBs) as well as environmental samples including animal tissues. A feature of the assay method is the use of nonionic detergent to solubilize the hydrophobic dibenzofurans in a manner permitting their binding to antibodies. The detection limits of the assay range between 20 pg and 4.0 ng of 2,3,7,8-TCDF. Extensive cross-reactivity studies indicated that the antiserum was fairly specific for TCDF although some cross-reactivity was found to structurally similar compounds. Values for TCDF in various Aroclors and animal tissues by radioimmunoassay correlated with those obtained by gas chromatography-mass spectrometry analysis. The radioimmunoassay is applicable to screening samples in order to minimize the demand for mass spectrometric screening and should be simple enough to be performed in most clinical laboratories. 3 tables, 1 figure.

  13. Rebooting Irish Higher Education: Policy Challenges for Challenging Times

    ERIC Educational Resources Information Center

    Hazelkorn, Ellen

    2014-01-01

    The 2008 global financial crisis cast a long shadow over Ireland's higher education and research system. The IMF said Ireland experienced an "unprecedented economic correction", while Ireland's National Economic and Social Development Office said Ireland was beset by five different crises: a banking crisis, a fiscal crisis, an…

  14. Restyling the Humanities Curriculum of Higher Education for Posthuman Times

    ERIC Educational Resources Information Center

    Siddiqui, Jamila R.

    2016-01-01

    The future viability of the humanities in higher education has been broadly debated. Yet, most of these debates are missing an important consideration. The humanities' object of study is the human, an object that some would argue has been replaced in our onto-epistemological systems by the posthuman. In her 2013 book, "The Posthuman,"…

  15. Higher Education in Times of Financial Distress: The Minnesota Experience

    ERIC Educational Resources Information Center

    Severns, Roger

    2012-01-01

    Like many states, Minnesota has incurred large budget deficits during the past two years. Those deficits have, in turn, led to changes in a number of areas of state government, particularly higher education. Faculty have incurred pay freezes and layoffs, programs have closed, and tuition increased. Campuses within the MnSCU system have been…

  16. Time for Action to Bolster Future of Higher Education

    ERIC Educational Resources Information Center

    Spellings, Margaret

    2007-01-01

    Higher education in America had its origins in New England more than 350 years ago. Since then, America's colleges and universities have been the incubators of great ideas, birthplaces of great inventions, and testing grounds of great individuals. For generations of New Englanders, a college education has provided the opportunity to fully embrace…

  17. Creating Time: Students, Technologies and Temporal Practices in Higher Education

    ERIC Educational Resources Information Center

    Gourlay, Lesley

    2014-01-01

    The nature of time has been considered in some depth within philosophy and social theory, while theoreticians have also explored interrelationships between temporality, artefacts and social process. However, the notion of time in mainstream educational theory and research has arguably been regarded as fixed, naturalised, undifferentiated…

  18. Time Management in Higher Education Administration: A Case Study.

    ERIC Educational Resources Information Center

    Lewis, Darrell R.; Dahl, Tor

    How do departmental chairpersons and deans in a major university setting manage their time? What are the major administrative activities and functions associated with such responsibilities? What relationships do these have with an ability to delegate, to control one's time for planning and self-initiated activities, or personal sense of…

  19. Higher plant biomarkers reflect palaeovegetation changes during Jurassic times

    NASA Astrophysics Data System (ADS)

    van Aarssen, Ben G. K.; Alexander, Robert; Kagi, Robert I.

    2000-04-01

    The relative abundances of three higher-plant-derived biomarkers, retene, cadalene and ip-iHMN, have been measured in marine sedimentary rocks from the northwest margin of Australia. It is thought that each biomarker represents input from a different plant type. The distributions of these three compounds form a fingerprint, representing higher plant input (HPF). Variations in HPF in Oxfordian sediments were nearly identical in all three locations, with retene becoming very abundant relative to the other two compounds with decreasing age of the sediment. This finding strongly suggests that the composition of terrestrial input during deposition largely determines HPF and that the possible effects of diagenesis and catagenesis on the distribution of the three biomarkers are relatively unimportant. The marked increase in the abundance of retene relative to that of cadalene during the Oxfordian is interpreted to reflect an increase in the contribution of plants that produced precursors for retene, i.e., conifers, brought about by a significant change in climate. This was exemplified by measuring the distributions of retene and cadalene, expressed in the higher plant parameter (HPP) for a suite of sediments from the Carnarvon Basin, Western Australia, covering the complete Jurassic period. The HPP profile displays three major cycles, each covering a period of at least 10 million years. This profile not only compared well with published palaeoclimate data, but also showed a remarkable similarity with second order cycles in the global sea level curve, thus strongly supporting the proposal that variations in HPF and HPP are indications of changes in palaeoclimate. The relation with global sea level further suggests that global factors, e.g., the atmospheric carbon dioxide concentration, may play a major role in determining the observed variations in the distributions of these higher-plant-derived biomarkers.

  20. Time Management in Higher Education Administration: A Case Study

    ERIC Educational Resources Information Center

    Lewis, Darrell R.; Dahl, Tor

    1976-01-01

    Drawing on data from a staff development project for administrators in a college at a major American university, it was determined that there is considerable commonality across individuals and that it is possible to deal with such issues as time management, job stress, and enjoyment on an organizational level. (Editor/JT)

  1. ARTICLES: Theoretical Study on Destruction Mechanism of 2,3,7,8-TCDD by O3 and NO3

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-hua; Wen, Zheng-cheng; Xu, Jiang-rong; Zhou, Jun-hu; Cen, Ke-fa

    2010-06-01

    In order to improve the destruction efficiency of dioxins and also for developing new dioxin control technology, the destruction mechanisms of 2,3,7,8-tetrachlorodihenzo-p-dioxin (2,3,7,8-TCDD) by O3 and NO3, were investigated employing quantum chemical calculations. For involved reactions, the microcosmic reaction processes were analyzed and depicted in detail based on geometry optimizations made by the B3LYP/6-31G(d) method. At the same time, the reaction activation energies were also calculated at the MP2/6-311G(d,p)//B3LYP/6-31G(d) level. Configuration analysis indicated that 2,3,7,8-TCDD could be destroyed by O3 and NO3 in two different ways. The destruction of 2,3,7,8-TCDD by O3 proceeded via the addition of O3 and the cleavage of C = C while the destruction of 2,3,7,8-TCDD by NO3 proceeded via the substitution of chlorine by NO3. Calculated results show that, the activation energy of the destruction reaction of 2,3,7,8-TCDD by NO3 (267.48 kJ/mol) is much larger than that of the destruction reaction of 2,3,7,8-TCDD by O3 (51.20 kJ/mol). This indicated that the destruction of 2,3,7,8-TCDD by O3 is much more efficient than that of 2,3,7,8-TCDD by NO3. The reason why the activation energy for the destruction reaction of 2,3,7,8-TCDD by NO3 is so large, is also discussed.

  2. Electron-impact ionization cross-section of argon ([sigma]+, N = 7,8)

    NASA Astrophysics Data System (ADS)

    Almeida, D. P.; Becker, K. H.; Deutsch, H.

    1997-04-01

    Multiple ionization cross-sections of argon (Ar-Arn+, with n = 7.8 by electron impact are measured for energies ranging from threshold up to 3000 eV. The data were obtained by a time-of-flight mass-to-charge spectrometric technique. A comparison with other experimental data and with semi-empirical calculations is presented. The integrated oscillator strength (M27+) for the production of Ar7+ was determined.

  3. Esthetic 7/8 crown--the Tucker technique.

    PubMed

    Allan, Randall J

    2009-01-01

    As restorative dentists, one of the largest challenges we face is to restore proper form and function while considering the impact on the esthetic outcome. One must consider the clinical strengths and weaknesses of various materials and their applicability in different situations. For each clinical situation, there is always a most favorable choice coordinating material and design for optimum physiological, functional and esthetic results. The cast gold 7/8 crown with esthetic buccal margin, as designed and advocated by Dr Richard V Tucker, is an extremely valuable procedure, providing a very long-lasting, esthetically pleasing restoration for extensive involvement of maxillary bicuspid or first molar teeth--particularly in cases where there has been some degree of recession of the buccal or mesial-buccal cusp, while that cusp remains strong and of good stock in the gingival third of the tooth. Under the right circumstances, these teeth can be extensively restored without showing the gold, while leaving the natural color and contours of the buccal cusp and avoiding insult to the gingival tissues from the restoration margin. All of these benefits contribute to esthetics that are superior to porcelain-to-metal or all-ceramic restorations, with less loss of tooth structure and trauma to the pulp.

  4. Time Work by Overworked Professionals: Strategies in Response to the Stress of Higher Status.

    PubMed

    Moen, Phyllis; Lam, Jack; Ammons, Samantha; Kelly, Erin L

    2013-05-01

    How are professionals responding to the time strains brought on by the stress of their higher status jobs? Qualitative data from professionals reveal (a) general acceptance of the emerging temporal organization of professional work, including rising time demands and blurred boundaries around work/ nonwork times and places, and (b) time work as strategic responses to work intensification, overloads, and boundarylessness. We detected four time-work strategies: prioritizing time, scaling back obligations, blocking out time, and time shifting of obligations. These strategies are often more work-friendly than family-friendly, but "blocking out time" and "time shifting" suggest promising avenues for work-time policy and practice. PMID:24039337

  5. State Spending on Higher Education: Testing the Balance Wheel over Time

    ERIC Educational Resources Information Center

    Delaney, Jennifer A.; Doyle, William R.

    2011-01-01

    This article considers the role of higher education in state budgets. It empirically models and tests the balance wheel hypothesis in a robust framework. The balance wheel model posits that in good economic times, higher education is an attractive area for states to fund and tends to be funded at a higher rate than other state budget categories.…

  6. Part-Time Higher Education in English Colleges: Adult Identities in Diminishing Spaces

    ERIC Educational Resources Information Center

    Esmond, Bill

    2015-01-01

    Adult participation in higher education has frequently entailed mature students studying part time in lower-ranked institutions. In England, higher education policies have increasingly emphasised higher education provision in vocational further education colleges, settings which have extensive adult traditions but which mainly teach…

  7. Changing Times of Feminism and Higher Education: From Community to Employability

    ERIC Educational Resources Information Center

    Moss, Dorothy; Richter, Ingrid

    2011-01-01

    This article discusses the creation of space and time for feminist approaches in higher education in the context of shifting community and employment relations and the restructuring of higher education space-time. It draws on the reflections of three feminist academics concerning aspects of their work biographies in two very different higher…

  8. High antiallergic activity of 5,6,4'-trihydroxy-7,8,3'-trimethoxyflavone and 5,6-dihydroxy-7,8,3',4'-tetramethoxyflavone from eau de cologne mint (Mentha×piperita citrata).

    PubMed

    Sato, Akihiko; Tamura, Hirotoshi

    2015-04-01

    The following compounds with higher antiallergic activities were isolated from eau de cologne mint leaves: 5,6,4'-trihydroxy-7,8-dimethoxyflavone (6), 5,6,4'-trihydroxy-7,8,3'-trimethoxyflavone (7), 5,6-dihydroxy-7,3',4'-trimethoxyflavone (8), 5,6-dihydroxy-7,8,3',4'-tetramethoxyflavone (9), and 5,6-dihydroxy-7,8,4'-trimethoxyflavone (10). The IC50 values of compounds 6-10 against RBL-2H3 cells were 6.7, 2.4, 5.6, 3.0, and 6.1μM. Compounds 7 and 9 (IC50 2.4μM and 3.0μM) had the highest antiallergic activities among the flavonoids previously reported. The amounts of 7, 9, and 10 isolated were fairly high, at 177.7mg/kg, 278.0mg/kg, and 179.7mg/kg in the mint, respectively. LD5 value (index of toxicity) and LD5/IC50 ratio of 7 and 9 indicate that the safety is greater than that of luteolin, a typical antiallergic substance. The extract containing powerful antiallergic flavones, 6-10 with higher hydrophobicity could be selectively separated from the extract containing luteolin and other flavonoid glycosides by partition with dichloromethane and water. Therefore, compounds 7 and 9 in mint, and the dichloromethane extract would be the most potent and preventive resources against type I allergy.

  9. Time as the Fourth Dimension in the Globalization of Higher Education

    ERIC Educational Resources Information Center

    Walker, Judith

    2009-01-01

    This paper calls for an analysis of time to be integrated into the theories on the globalization of higher education. Specifically, the author argues that academic capitalism, fuelled by globalization, has led to changes in the university visible in time/space compression, time acceleration, the reification of time and our internalization of the…

  10. The Legal Rights of Tenured and Part-Time Faculty Members in Higher Education.

    ERIC Educational Resources Information Center

    Corley, Sherie P.

    A review of faculty-related court decisions in the areas of status, compensation, and unit determination points out legal rights of part-time and full-time faculty in higher education. These rights have been tested and defined by many court cases. Litigation has occurred about the difference between part-time and full-time faculty. In regard to…

  11. The Benefits of Part-Time Undergraduate Study and UK Higher Education Policy: A Literature Review

    ERIC Educational Resources Information Center

    Bennion, Alice; Scesa, Anna; Williams, Ruth

    2011-01-01

    Part-time study in the UK is significant: nearly 40 per cent of higher education students study part-time. This article reports on a literature review that sought to understand the economic and social benefits of part-time study in the UK. It concludes that there are substantial and wide-ranging benefits from studying part-time. The article also…

  12. Quality differences between NILs of wheat variety Long 97-586 possessing HMW-GS 7+8 and 7.

    PubMed

    Zhang, LiLi; Zhang, YanBin; Li, JiLin; Zhao, HaiBin; Song, QingJie; Yu, HaiYang; Zhang, ChunLi; Xin, WenLi; Xiao, ZhiMin

    2010-02-01

    The high molecular weight glutenin subunits (HMW-GS) 7+8 were introduced into the Long 97-586 (1, 7, 2+12) wheat variety (Triticum aestivum) by 5 consecutive backcrosses with biochemical marker-assisted selection. Nearly isogenic lines (NILs) of HMW-GS 7 and 7+8 were obtained, and the NILs were planted in the experimental field at the Crop Breeding Institute of Heilongjiang Academy of Agricultural Science in 2004-2006. The field experiments were designed using the two-column contrast arrangement method with six replicates in 2004-2005 and four replicates in 2006. The result of three years experiments showed that the differences between NILs of Long 97-586 with subunit 7 and those with subunits 7+8 in the quality parameters of flour protein content and dry gluten content were negligible (P>0.1). However, the differences in some of the quality parameters were remarkably significant (P<0.01), including wet gluten content, ratio of wet gluten/dry gluten, gluten index, Zeleny sedimentation, ratio of sedimentation/dry gluten, and the farinogram parameters of water absorption, development time, stability, breakdown time and degree of softening. The difference between NILs with subunits 7+8 and subunit 7 was significant (P<0.05) on the alveogram W value and had a critical value (P=0.05) on the alveogram P value in 2006. The results show that HMW-GS 7+8 is far superior to HMW-GS 7 in terms of baking quality. The possibilities of using subunits 7+8 and subunit 7 in breeding strong and weak gluten wheat varieties are discussed in this paper. PMID:20596839

  13. SORPTION OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN TO SOILS FROM WATER/METHANOL MIXTURES

    EPA Science Inventory

    Sorption of 14C-labeled 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to soils from water/methanol mixtures has been evaluated by batch shake testing. Uncontaminated soils from Times Beach, MO, were used in these experiments and ranged in fraction organic carbon (U...

  14. Pulse transmission receiver with higher-order time derivative pulse correlator

    DOEpatents

    Dress, Jr., William B.; Smith, Stephen F.

    2003-09-16

    Systems and methods for pulse-transmission low-power communication modes are disclosed. A pulse transmission receiver includes: a higher-order time derivative pulse correlator; a demodulation decoder coupled to the higher-order time derivative pulse correlator; a clock coupled to the demodulation decoder; and a pseudorandom polynomial generator coupled to both the higher-order time derivative pulse correlator and the clock. The systems and methods significantly reduce lower-frequency emissions from pulse transmission spread-spectrum communication modes, which reduces potentially harmful interference to existing radio frequency services and users and also simultaneously permit transmission of multiple data bits by utilizing specific pulse shapes.

  15. Higher Education Students in Part-Time Work in a Chinese City

    ERIC Educational Resources Information Center

    Morrison, Keith

    2009-01-01

    This article discusses students taking part-time work whilst studying higher education (HE). It suggests that cross-national trends can be observed in the purposes, types, benefits, negative aspects and outcomes of part-time work by HE students. The paper reviews literature on HE students working part-time in the UK and the US, and UNESCO studies…

  16. Thermal management for heavy vehicles (Class 7-8 trucks)

    SciTech Connect

    Wambsganss, M.W.

    2000-04-03

    Thermal management is a crosscutting technology that has an important effect on fuel economy and emissions, as well as on reliability and safety, of heavy-duty trucks. Trends toward higher-horsepower engines, along with new technologies for reducing emissions, are substantially increasing heat-rejection requirements. For example, exhaust gas recirculation (EGR), which is probably the most popular near-term strategy for reducing NO{sub x} emissions, is expected to add 20 to 50% to coolant heat-rejection requirements. There is also a need to package more cooling in a smaller space without increasing costs. These new demands have created a need for new and innovative technologies and concepts that will require research and development, which, due to its long-term and high-risk nature, would benefit from government funding. This document outlines a research program that was recommended by representatives of truck manufacturers, engine manufacturers, equipment suppliers, universities, and national laboratories. Their input was obtained through personal interviews and a plenary workshop that was sponsored by the DOE Office of Heavy Vehicle Technologies and held at Argonne National Laboratory on October 19--20, 1999. Major research areas that received a strong endorsement by industry and that are appropriate for government funding were identified and included in the following six tasks: (1) Program management/coordination and benefits/cost analyses; (2) Advanced-concept development; (3) Advanced heat exchangers and heat-transfer fluids; (4) Simulation-code development; (5) Sensors and control components development; and (6) Concept/demonstration truck sponsorship.

  17. 2,3,7,8-TCDD toxic equivalents in Great Lakes salmon derived using mammalian, bird, and fish cell bioassays

    SciTech Connect

    Heuvel, M.R. van den; Clemons, J.H.; Bols, N.C.; Dixon, D.G.; Kennedy, S.W.; Metcalfe, T.L.; Smith, I.R.

    1994-12-31

    Chinook salmon from lakes Ontario and Huron, and Coho salmon from lakes Ontario and Erie were captured during their fall spawning migration. Subsamples of extracted pooled muscle, liver and egg tissue were used to measure congener specific PCBs, chlorinated dioxins and furans as well as bioassay derived 2,3,7,8-TCDD toxic equivalent concentration (TEC). The cell culture bioassays used to measure TECs were rat hepatoma (H411E) and rainbow trout hepatocyte (RTL-W1) continuous cell lines as well as chicken embryo hepatocyte primary culture (CEH). Although excellent correlations were found between all 3 cell culture bioassays, CEH was found to be 10 times and 30 times more sensitive than H411E and RTL-W1 respectively. Lake Ontario TECs were found to be higher than either Lake Huron or Lake Erie samples for both species of Salmon, and Chinook salmon was elevated over Coho Salmon. Chemical data indicates that the more toxic coplanar PCBs are selectively concentrated in eggs as compared to liver and muscle. Bioassay derived TECs are discussed with regard to chemical contribution of the PCB and dioxin/furan congeners based on an additive model.

  18. Matrix metalloproteinases -1, -2, -3, -7, -8, -12, and -13 in gingival crevicular fluid during orthodontic tooth movement: a longitudinal randomized split-mouth study.

    PubMed

    Canavarro, Cristiane; Teles, Ricardo Palmier; Capelli Júnior, Jonas

    2013-10-01

    This randomized split-mouth study aimed to examine the levels of matrix metalloproteinases (MMPs) -1, -2, -3, -7, -8, -12, and -13 in the gingival crevicular fluid (GCF) at different time points during orthodontic tooth movement. A total of 16 healthy orthodontic subjects (7 females, 9 males; mean age, 17.7 years) who needed their first upper premolars extracted were enrolled. One randomly chosen maxillary canine was subjected to a distalizing force and was considered to be the test side. The contralateral canine, which was not subjected to any force but was included in the orthodontic appliance, was used as a control side. GCF sampling was performed at both the mesial (tension) and distal (pressure) test and control sites at baseline, immediately before applying the orthodontic appliance, and after 1 and 24 hours and 7, 14, and 21 days. A multiplexed bead immunoassay was used to analyse the GCF samples. The mean levels of the MMP-1, -2, -3, -7, -8, -12, and -13 were not significantly different between the test and control groups in each time showed. The comparisons between the tension and pressure sites were also not significantly different at each individual time. A few variations focused on MMP-1 and -3, but the expression of MMP-8 was higher than that of the other MMPs. MMPs are released in sufficient quantities such that tooth movement occurs but with no significant increase in GCF levels.

  19. Time Work by Overworked Professionals: Strategies in Response to the Stress of Higher Status

    PubMed Central

    Moen, Phyllis; Lam, Jack; Ammons, Samantha; Kelly, Erin L.

    2013-01-01

    How are professionals responding to the time strains brought on by the stress of their higher status jobs? Qualitative data from professionals reveal (a) general acceptance of the emerging temporal organization of professional work, including rising time demands and blurred boundaries around work/ nonwork times and places, and (b) time work as strategic responses to work intensification, overloads, and boundarylessness. We detected four time-work strategies: prioritizing time, scaling back obligations, blocking out time, and time shifting of obligations. These strategies are often more work-friendly than family-friendly, but “blocking out time” and “time shifting” suggest promising avenues for work-time policy and practice. PMID:24039337

  20. Part-time Faculty Job Satisfaction in Higher Education: A Literature Review

    ERIC Educational Resources Information Center

    Howell, Scott L.; Hoyt, Jeff

    2007-01-01

    The purpose of this literature review was to inform researchers of those predictive factors of job satisfaction previously identified for part-time faculty in higher education. They used the information gathered to help develop a survey instrument that was administered to 700 part-time faculty at their own institution. The results of the study,…

  1. Preparation and Support for Part-Time Teachers in Higher Education: Case Studies of Departmental Practice.

    ERIC Educational Resources Information Center

    Forster, Fred, Comp.; Thompson, Sheila, Comp.

    This publication presents 14 departmental case studies of the preparation and support provided to part-time teachers in Scottish institutions of higher education. The case studies are grouped in four sections according to the category of part-time staff involved: practicing professionals (professional teaching assistants, lawyers, artists, and…

  2. The Motivations and Outcomes of Studying for Part-Time Mature Students in Higher Education

    ERIC Educational Resources Information Center

    Swain, Jon; Hammond, Cathie

    2011-01-01

    This paper examines the motivations and outcomes for mature students who study part-time in higher education (HE) in the UK. Although many students in HE are mature part-time learners, they have not been the specific focus of much research or policy interest. In-depth narrative interviews were carried out with 18 graduates who had studied…

  3. The Supply of Part-Time Higher Education in the UK. Research Report

    ERIC Educational Resources Information Center

    Callender, Claire; Birkbeck, Anne Jamieson; Mason, Geoff

    2010-01-01

    This report explores the supply of part-time higher education in the UK, with particular consideration to the study of part-time undergraduate provision in England. It is the final publication in the series of reports on individual student markets that were commissioned by Universities UK following the publication of the reports on the Future size…

  4. Magnitude Scaling of the early displacement for the 2007, Mw 7.8 Tocopilla sequence (Chile)

    NASA Astrophysics Data System (ADS)

    Lancieri, M.; Fuenzalida, A.; Ruiz, S.; Madariaga, R. I.

    2009-12-01

    We investigate the empirical relationships between the initial portion of P and S-phase and the final event magnitude, on the Tocopilla (Chile) event and its aftershocks. Such correlations, on which real-time magnitude estimation for seismic early warning is founded, have been widely studied on several data sets, merging earthquakes generated in different tectonic settings and recorded with very different networks. The Tocopilla (Mw 7.8) earthquake, occurred along the northern Chile seismic gap on 14 November 2007, provides, together with its aftershocks, a unique opportunity of studying a homogeneous data set in terms of tectonic environment, focal mechanism, and recording network. The preliminary analysis required to build the seismic catalogue includes the automatic identification of more than 570 aftershocks using an automatic phase detector and picker algorithm, and the subsequent location of the events through a non-linear and probabilistic code. The seismic moment (M0) has been calculated by spectral modeling of P and S waves, assuming a Brune omega-square model. This analysis also yields values for the corner frequency and quality factor. The estimated range of moment magnitude for the aftershocks sequence is [2.8 - 6.8]. The correlation between the low pass filtered peak displacement (PD) and the final magnitude has been investigated for 90 events with magnitude greater than 4. These include the main event, its larger aftershock (Mw 6.8 occurred twenty-four hours after the main shock), and seven events with magnitude greater than 5.7. The recovered relationships confirm the observations of Zollo et al. [2006, 2007] of a clear correlation between distance corrected PD and final magnitude in the magnitude range [4.0 - 7.4], when considering time windows of 4 sec of P- or 2 sec of S- wave. In contrast with the previous studies, when examining time windows of 2 sec of P-wave, we surprisingly do not observe any saturation effect for magnitudes greater than 6

  5. [{sup 3}H]-2,3,7,8-TCDD uptake and elimination kinetics of medaka (Oryzias latipes)

    SciTech Connect

    Schmieder, P.; Lothenbach, D.; Tietge, J.; Erickson, R.; Johnson, R.

    1995-10-01

    Uptake and elimination rate constants for [{sup 3}H]-2,3,7,8-tetrachlorodibenzo-p-dioxin ([{sup 3}H]TCDD) were estimated by exposing medaka (Oryzias latipes) to [{sup 3}H]TCDD in flowing water with no solvent carriers. Uptake was determined from body-burdens measured on exposure days 0, 2, 4, 6, 10, and 12. Elimination was quantified for whole fish after 28, 90, and 175 d in uncontaminated water. Medaka accumulated [{sup 3}H]TCDD at a rapid rate, achieving residues 24,000 times the water concentration after 12 d, with no indication of approach to steady state. After 6 months in uncontaminated water, the pg TCDD/g decreased by 69%, much of the decrease due to growth dilution as evidenced by only a 47% decrease in the pg TCDD/fish. Uptake and elimination rate constant (2,300 ml/g/d and 0.0045/d, respectively) were estimated by fitting a one-compartment, linear, mass-balance model to the data, adjusting for growth rate. The experimental design, including solvent-free delivery of [{sup 3}H]TCDD, exposure at concentrations below maximum water solubility, and measurement of fish growth and lipid content during a 6-month elimination phase, resulted in a predicted steady-state bioconcentration factor (BCF) for medaka of 510,000, a number considerably higher than previously reported for dioxin BCFs. Kinetic parameters were used to successfully predict TCDD BCF in medaka exposed independently.

  6. Bioavailability of 2,3,7,8-TCDD, 2,3,7,8-TCDF and PCBs to marine benthos from passaic river sediments

    SciTech Connect

    Rubinstein, N.I.; Pruell, R.J.; Taplin, B.K.; LiVolsi, J.A.; Norwood, C.B.

    1990-01-01

    The bioaccumulation and depuration of 2,3,7,8-tetrachlorodibenzo-p-dioxin, 2,3,7,8-tetrachlorodibenzofuran and polychlorinated biphenyls by marine benthos exposed to environmentally contaminated sediment were measured in a laboratory study. Sandworms (Nereis virens), clams (Macoma nasuta) and shrimp (Palaemonetes pugio) were exposed to sediment from the Passaic River, New Jersey for up to 180 days. Worms accumulated the highest concentrations of these compounds. Uptake and depuration rates were slowest in the worms and most rapid in the clams.

  7. Teratogenicity of 2,3,7,8-tetrachlorodibenzofuran in the mouse

    SciTech Connect

    Hassoun, E.; d'Argy, R.; Dencker, L.

    1984-01-01

    2,3,7,8-Tetrachlorodibenzofuran (TCDBF) was administered in single doses (0.1-0.8 mg/kg body weight) intraperitoneally to pregnant C57BL mice on d 10, 11, 12, or 13 of gestation. A dose-dependent increase was observed in the frequency of fetal resorptions and fetal death, especially in the earlier stages (d 10-11). Cleft palate and hydronephrosis as well appeared in a dose-dependent manner, with a peak in sensitivity after administration on d 11-12. TCDBF given at a dose level of 0.1 mg/kg body weight on d 12 of gestation (only dose- and stage-tested) produced a marked thymic hypoplasia as well. A few cases of general hydrops occurred. The pattern of malformations and time of sensitivity corresponded well to that observed earlier after administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; ED50 approx. = 25 ..mu..g/kg) and 3,3',4,4'-tetrachloroazoxybenzene (TCAOB; ED50 approx. = 6 mg/kg), two congeners of TCDBF, indicating common mechanisms of action of this family of compounds. Ornithine decarboxylase (ODC) is an important enzyme in cell proliferation and growth with a high activity in embryonic tissues. Liver ODC activity has previously been found to be stimulated by TCDD in weanling mice. However, this enzyme was not found to be stimulated in fetal and placental tissues, but slightly in maternal kidney after treatment with TCDBF in teratogenic doses. It is possible that the ODC activity increases under certain conditions only, on administration of TCDD and its congeners. 40 references, 3 tables, 3 figures.

  8. Finite time control for MIMO nonlinear system based on higher-order sliding mode.

    PubMed

    Liu, Xiangjie; Han, Yaozhen

    2014-11-01

    Considering a class of MIMO uncertain nonlinear system, a novel finite time stable control algorithm is proposed based on higher-order sliding mode concept. The higher-order sliding mode control problem of MIMO nonlinear system is firstly transformed into finite time stability problem of multivariable system. Then continuous control law, which can guarantee finite time stabilization of nominal integral chain system, is employed. The second-order sliding mode is used to overcome the system uncertainties. High frequency chattering phenomenon of sliding mode is greatly weakened, and the arbitrarily fast convergence is reached. The finite time stability is proved based on the quadratic form Lyapunov function. Examples concerning the triple integral chain system with uncertainty and the hovercraft trajectory tracking are simulated respectively to verify the effectiveness and the robustness of the proposed algorithm. PMID:25277626

  9. Finite time control for MIMO nonlinear system based on higher-order sliding mode.

    PubMed

    Liu, Xiangjie; Han, Yaozhen

    2014-11-01

    Considering a class of MIMO uncertain nonlinear system, a novel finite time stable control algorithm is proposed based on higher-order sliding mode concept. The higher-order sliding mode control problem of MIMO nonlinear system is firstly transformed into finite time stability problem of multivariable system. Then continuous control law, which can guarantee finite time stabilization of nominal integral chain system, is employed. The second-order sliding mode is used to overcome the system uncertainties. High frequency chattering phenomenon of sliding mode is greatly weakened, and the arbitrarily fast convergence is reached. The finite time stability is proved based on the quadratic form Lyapunov function. Examples concerning the triple integral chain system with uncertainty and the hovercraft trajectory tracking are simulated respectively to verify the effectiveness and the robustness of the proposed algorithm.

  10. Higher-Order, Space-Time Adaptive Finite Volume Methods: Algorithms, Analysis and Applications

    SciTech Connect

    Minion, Michael

    2014-04-29

    The four main goals outlined in the proposal for this project were: 1. Investigate the use of higher-order (in space and time) finite-volume methods for fluid flow problems. 2. Explore the embedding of iterative temporal methods within traditional block-structured AMR algorithms. 3. Develop parallel in time methods for ODEs and PDEs. 4. Work collaboratively with the Center for Computational Sciences and Engineering (CCSE) at Lawrence Berkeley National Lab towards incorporating new algorithms within existing DOE application codes.

  11. An efficient higher-order PML in WLP-FDTD method for time reversed wave simulation

    NASA Astrophysics Data System (ADS)

    Wei, Xiao-Kun; Shao, Wei; Ou, Haiyan; Wang, Bing-Zhong

    2016-09-01

    Derived from a stretched coordinate formulation, a higher-order complex frequency shifted (CFS) perfectly matched layer (PML) is proposed for the unconditionally stable finite-difference time-domain (FDTD) method based on weighted Laguerre polynomials (WLPs). The higher-order PML is implemented with an auxiliary differential equation (ADE) approach. In order to further improve absorbing performance, the parameter values of stretching functions in the higher-order PML are optimized by the multi-objective genetic algorithm (MOGA). The optimal solutions can be chosen from the Pareto front for trading-off between two independent objectives. It is shown in a numerical test that the higher-order PML is efficient in terms of attenuating propagating waves and reducing late time reflections. Moreover, the higher-order PML can be placed very close to the wall when analyzing the channel characteristics of time reversal (TR) waves in a multipath indoor environment. Numerical examples of TR wave propagation demonstrate the availability of the proposed method.

  12. Iterative generation of higher-order nets in polynomial time using linear programming.

    PubMed

    Roy, A; Mukhopadhyay, S

    1997-01-01

    This paper presents an algorithm for constructing and training a class of higher-order perceptrons for classification problems. The method uses linear programming models to construct and train the net. Its polynomial time complexity is proven and computational results are provided for several well-known problems. In all cases, very small nets were created compared to those reported in other computational studies.

  13. Curriculum Characteristics of Time-Compressed Course in a U.S. Higher Education Institution

    ERIC Educational Resources Information Center

    Hyun, Eunsook; Kretovics, Mark; Crowe, Alicia

    2006-01-01

    The study explored characteristics of the curriculum practice of higher education faculty in the context of time-compressed (e.g., 5-6 weeks) courses as compared with regular term (15-16 weeks) courses. The researchers used open-ended questions on a web-based survey at a large doctoral-extensive university in a Midwestern state in the United…

  14. "Times Higher Education" 100 under 50 Ranking: Old Wine in a New Bottle?

    ERIC Educational Resources Information Center

    Soh, Kaycheng

    2013-01-01

    "Times Higher Education" 100 under 50 ranking is a new twist to the university ranking. It focuses on universities that have a history of 50 years or less with the purpose of offsetting the advantage of prestige of the older ones. This article re-analysed the data publicly available and looked into relevant conceptual and statistical issues. The…

  15. Analyzing the Anglo-American Hegemony in the "Times Higher Education" Rankings

    ERIC Educational Resources Information Center

    Kaba, Amadu Jacky

    2012-01-01

    This study analyzes the 2009 "Times Higher Education"-QS top 200 universities in the world. Based on this analysis the study claims that the THS reflects the phenomenon of Anglo American hegemony. The United States with 54 universities and the United Kingdom with 29 dominated the THS. In addition, six out of every ten universities on the top 200…

  16. A time-saving method for higher plant tests in hydroculture.

    PubMed

    Andersohn, Cornelia; Fuchs, Maike; Seyed-Mansouri, Regina; Fleischmann, Susanne; Wilke, Berndt-Michael

    2002-01-01

    For higher plant tests in hydroculture we developed a method to unify the usually separately performed germination and growth testing. This method renders unnecessary the time-consuming and laborious installation of the germinated plants into the growth system. PMID:11931464

  17. Institutional View of Part-Time Faculty Management in Higher Education Institutes in China

    ERIC Educational Resources Information Center

    Li, Zhifeng; Jiang, Xiulan; Li, Hongbo

    2007-01-01

    Part-time faculty has become an important labor force in Chinese colleges and universities. The number of them has risen rapidly and its structure varies in different types of higher education institutes (HEIs), which results from integration of the social motivation and the inner motivation of schools' reform. From the institutional point of…

  18. Infrasonic and seismic signals from Mw7.8 Nepal earthquake of April 25,2015

    NASA Astrophysics Data System (ADS)

    Yuan, Songyong; Su, Wei

    2016-04-01

    On April 25, 2015, at 06:11:26 UTC (14:11:26 Beijing Time), a powerful earthquake (Mw=7.8) occurred in Nepal near Tibet of China. The epicenter (28.24°N,84.74°E,focal depth 15 km) was about 82 km NW of Kathmandu, Nepal. The earthquake was related to collision between the India plate and the Eurasian plate. At a distance of 1400 km from the epicenter, infrasonic and seismic signals were recorded by Tengchong seismo-acoustic array located in southwest of China. Ground-coupled air waves generated at the station by the vertical displacement of the seismic waves which arrival time and waveform characteristics are same as seismic waves. The PMCC results indicated that the infrasonic waves showed a consistent acoustic trace velocity of approximately 0.392 km/s from 14:33 to 15:07(Beijing Time) but the azimuth of arrival decreased with time from 340 to 260 degrees. The azimuth variations and the expansion of the signal duration suggested that the Mountains of eastern Tibet Plateau acted as sources of infrasonic waves and radiated the infrasound that traveled to Tengchong seismo-acoustic array. For large earthquakes occurring in mountainous regions, infrasonic measurements are valuable for the analysis of the remote effects of earthquakes.

  19. Flavonoid derivative 7,8-DHF attenuates TBI pathology via TrkB activation.

    PubMed

    Agrawal, Rahul; Noble, Emily; Tyagi, Ethika; Zhuang, Yumei; Ying, Zhe; Gomez-Pinilla, Fernando

    2015-05-01

    Traumatic brain injury (TBI) is followed by a state of metabolic dysfunction, affecting the ability of neurons to use energy and support brain plasticity; there is no effective therapy to counteract the TBI pathology. Brain-derived neurotrophic factor (BDNF) has an exceptional capacity to support metabolism and plasticity, which highly contrasts with its poor pharmacological profile. We evaluated the action of a flavonoid derivative 7,8-dihydroxyflavone (7,8-DHF), a BDNF receptor (TrkB) agonist with the pharmacological profile congruent for potential human therapies. Treatment with 7,8-DHF (5mg/kg, ip, daily for 7 days) was effective to ameliorate the effects of TBI on plasticity markers (CREB phosphorylation, GAP-43 and syntaxin-3 levels) and memory function in Barnes maze test. Treatment with 7,8-DHF restored the decrease in protein and phenotypic expression of TrkB phosphorylation after TBI. In turn, intrahippocampal injections of K252a, a TrkB antagonist, counteracted the 7,8-DHF induced TrkB signaling activation and memory improvement in TBI, suggesting the pivotal role of TrkB signaling in cognitive performance after brain injury. A potential action of 7,8-DHF on cell energy homeostasis was corroborated by the normalization in levels of PGC-1α, TFAM, COII, AMPK and SIRT1 in animals subjected to TBI. Results suggest a potential mechanism by which 7,8-DHF counteracts TBI pathology via activation of the TrkB receptor and engaging the interplay between cell energy management and synaptic plasticity. Since metabolic dysfunction is an important risk factor for the development of neurological and psychiatric disorders, these results set a precedent for the therapeutic use of 7,8-DHF in a larger context.

  20. Flavonoid derivative 7,8-DHF attenuates TBI pathology via TrkB activation

    PubMed Central

    Agrawal, Rahul; Noble, Emily; Tyagi, Ethika; Zhuang, Yumei; Ying, Zhe; Gomez-Pinilla, Fernando

    2015-01-01

    Traumatic brain injury (TBI) is followed by a state of metabolic dysfunction, affecting the ability of neurons to use energy and support brain plasticity; there is no effective therapy to counteract the TBI pathology. Brain-derived neurotrophic factor (BDNF) has an exceptional capacity to support metabolism and plasticity, which highly contrasts with its poor pharmacological profile. We evaluated the action of a flavonoid derivative 7,8-dihydroxyflavone (7,8-DHF), a BDNF receptor (TrkB) agonist with the pharmacological profile congruent for potential human therapies. Treatment with 7,8-DHF (5 mg/kg, ip, daily for 7 days) was effective to ameliorate the effects of TBI on plasticity markers (CREB phosphorylation, GAP-43 and syntaxin-3 levels) and memory function in Barnes maze test. Treatment with 7,8-DHF restored the decrease in protein and phenotypic expression of TrkB phosphorylation after TBI. In turn, intrahippocampal injections of K252a, a TrkB antagonist, counteracted the 7,8-DHF induced TrkB signaling activation and memory improvement in TBI, suggesting the pivotal role of TrkB signaling in cognitive performance after brain injury. A potential action of 7,8-DHF on cell energy homeostasis was corroborated by the normalization in levels of PGC-1α, TFAM, COII, AMPK and SIRT1 in animals subjected to TBI. Results suggest a potential mechanism by which 7,8-DHF counteracts TBI pathology via activation of the TrkB receptor and engaging the interplay between cell energy management and synaptic plasticity. Since metabolic dysfunction is an important risk factor for the development of neurological and psychiatric disorders, these results set a precedent for the therapeutic use of 7,8-DHF in a larger context. PMID:25661191

  1. Effects of 2,3,7,8-TCDD on the larvae of fathead minnows (Pimephales promelas)

    SciTech Connect

    Olivieri, C.E.; Cooper, K.R.

    1994-12-31

    This study evaluated the sensitivity of the fathead minnow larvae to 2,3,7,8-TCDD. There are no reported studies that have examined 2,3,7,8-TCDD toxic effects on fathead minnow larvae (0.0017--0.0094 g). One month old fathead minnow larvae were exposed to varying concentrations of [H{sup 3}]2,3,7,8-TCDD for 24h, and then were transferred into clean water. The no-treatment, acetone-control and 2,3,7,8-TCDD exposed larvae were observed for at least 32 days after exposure. Mortality, growth and appearance of a wasting-type syndrome were noted. The tissue dose were based on larvae wet weight. One hundred percent mortality was observed at a tissue dose of 163 ng/g at 32 days. The wasting-type syndrome appeared at day 7 after the 2,3,7,8-TCDD exposure. Statistically significant differences in growth (total length and weight) were observed at tissue doses as low as 20 ng/g. The wasting-type syndrome was observed in all fish by day 20. The 2,3,7,8-TCDD tissue level showing this effect was 44 ng/g. These results suggested that the fathead minnow larvae are more sensitive than the Japanese medaka larvae, and not as sensitive as the lake trout.

  2. American Higher Education in 1975 and 1976: The Academy's Response to Continuing Kondratieff Recession as Reported in "The Times Higher Education Supplement" (London).

    ERIC Educational Resources Information Center

    Hawley, John B.; And Others

    Articles on American higher education that appeared in 1975 and 1976 in "The Times Higher Education Supplement" (London) are analyzed in connection with two statements about American society and its economy. These statements are Joseph A. Schumpeter's 1939 analysis of business cycles, and James B. Shuman's and Davis Rosenau's 1972 description of…

  3. Multi-nanosecond high power pulse generation at 7.8GHz with a dielectric-loaded power extractor.

    SciTech Connect

    Conde, M..; Gai, W.; Konecny, R.; Liu, W.; Power, J. G.; Gao, F.; Jing, C.; Wong, T.; Yusof, Z.; High Energy Physics; Illinois Inst. of Tech.; Euclid Techlabs LLC; IEEE

    2009-06-01

    Power extraction from charged particle beams is a prospective way to develop future high power radio frequency (RF) sources. We have designed and tested a 7.8 GHz power extractor based on a dielectric-loaded waveguide. Building upon earlier work on single electron bunch tests, 10 ns and 22 ns megawatt-level RF pulses have been generated with trains consisting of 16 electron bunches each, by using a laser splitting-recombination scheme. In addition, 44 MW of peak power has been generated with a train consisting 4 electron bunches. Behaviors of higher-order-modes are also explored.

  4. Higher-order brick-tetrahedron hybrid method for Maxwell's equations in time domain

    NASA Astrophysics Data System (ADS)

    Winges, Johan; Rylander, Thomas

    2016-09-01

    We present a higher-order brick-tetrahedron hybrid method for Maxwell's equations in time domain. Brick-shaped elements are used for large homogeneous parts of the computational domain, where we exploit mass-lumping and explicit time-stepping. In regions with complex geometry, we use an unstructured mesh of tetrahedrons that share an interface with the brick-shaped elements and, at the interface, tangential continuity of the electric field is imposed in the weak sense by means of Nitsche's method. Implicit time-stepping is used for the tetrahedrons together with the interface. For cavity resonators, the hybrid method reproduces the lowest non-zero eigenvalues with correct multiplicity and, for geometries without field singularities from sharp corners or edges, the numerical eigenvalues converge towards the analytical result with an error that is approximately proportional to h2p, where h is the cell size and p is the polynomial order of the elements. For a rectangular waveguide, a layer of tetrahedrons embedded in a grid of brick-shaped elements yields a low reflection coefficient that scales approximately as h2p. Finally, we demonstrate hybrid time-stepping for a lossless closed cavity resonator, where the time-domain response is computed for 300,000 time steps without any signs of instabilities.

  5. Fingerprinting 2,3,7,8-tetrachlorodibenzodioxin contamination within the lower Passaic River.

    PubMed

    Quadrini, James D; Ku, Wen; Connolly, John P; Chiavelli, Deborah A; Israelsson, Peter H

    2015-07-01

    The lower Passaic River is an operable unit of the Diamond Alkali Superfund site at 80 and 120 Lister Avenue in Newark, New Jersey, USA. Between 1948 and 1969, the Diamond Shamrock Chemicals Company and its predecessors manufactured chemicals such as pesticides and phenoxy herbicides, including 2,4,5-trichlorophenol, which is a precursor to 2,4,5-trichlorophenoxyacetic acid, one of the primary components used to make the military defoliant Agent Orange. A by-product of this manufacturing process was 2,3,7,8-tetrachlorodibenzodioxin (2,3,7,8-TCDD), and the site is considered the dominant source of 2,3,7,8-TCDD to the lower Passaic River and its environs. Several investigators have identified the ratio of 2,3,7,8-TCDD to total TCDD as a fingerprint for the site source. The present study presents data that establish polychlorinated dibenzodioxin/polychlorinated dibenzofuran (collectively, PCDD/F) congener and homolog fingerprints of soil and sump samples from the site. It then compares those fingerprints to the PCDD/F congener and homolog patterns in lower Passaic River sediments. The similarity of the patterns in lower Passaic River sediments to the site fingerprint indicates the site is the dominant source of the 2,3,7,8-TCDD in sediments within approximately the lower 14 miles of the lower Passaic River, excluding, for the purposes of the present discussion, Newark Bay. In addition, PCDD/F congener data indicate that the ratio of 1,3,7,8-TCDD to 2,3,7,8-TCDD is another marker of the site and corroborates the findings from the other fingerprints. PMID:25726763

  6. Fingerprinting 2,3,7,8-tetrachlorodibenzodioxin contamination within the lower Passaic River

    PubMed Central

    Quadrini, James D; Ku, Wen; Connolly, John P; Chiavelli, Deborah A; Israelsson, Peter H

    2015-01-01

    The lower Passaic River is an operable unit of the Diamond Alkali Superfund site at 80 and 120 Lister Avenue in Newark, New Jersey, USA. Between 1948 and 1969, the Diamond Shamrock Chemicals Company and its predecessors manufactured chemicals such as pesticides and phenoxy herbicides, including 2,4,5-trichlorophenol, which is a precursor to 2,4,5-trichlorophenoxyacetic acid, one of the primary components used to make the military defoliant Agent Orange. A by-product of this manufacturing process was 2,3,7,8-tetrachlorodibenzodioxin (2,3,7,8-TCDD), and the site is considered the dominant source of 2,3,7,8-TCDD to the lower Passaic River and its environs. Several investigators have identified the ratio of 2,3,7,8-TCDD to total TCDD as a fingerprint for the site source. The present study presents data that establish polychlorinated dibenzodioxin/polychlorinated dibenzofuran (collectively, PCDD/F) congener and homolog fingerprints of soil and sump samples from the site. It then compares those fingerprints to the PCDD/F congener and homolog patterns in lower Passaic River sediments. The similarity of the patterns in lower Passaic River sediments to the site fingerprint indicates the site is the dominant source of the 2,3,7,8-TCDD in sediments within approximately the lower 14 miles of the lower Passaic River, excluding, for the purposes of the present discussion, Newark Bay. In addition, PCDD/F congener data indicate that the ratio of 1,3,7,8-TCDD to 2,3,7,8-TCDD is another marker of the site and corroborates the findings from the other fingerprints. Environ Toxicol Chem 2015;34:1485–1498. © 2015 The Authors. Published by SETAC. PMID:25726763

  7. Fingerprinting 2,3,7,8-tetrachlorodibenzodioxin contamination within the lower Passaic River.

    PubMed

    Quadrini, James D; Ku, Wen; Connolly, John P; Chiavelli, Deborah A; Israelsson, Peter H

    2015-07-01

    The lower Passaic River is an operable unit of the Diamond Alkali Superfund site at 80 and 120 Lister Avenue in Newark, New Jersey, USA. Between 1948 and 1969, the Diamond Shamrock Chemicals Company and its predecessors manufactured chemicals such as pesticides and phenoxy herbicides, including 2,4,5-trichlorophenol, which is a precursor to 2,4,5-trichlorophenoxyacetic acid, one of the primary components used to make the military defoliant Agent Orange. A by-product of this manufacturing process was 2,3,7,8-tetrachlorodibenzodioxin (2,3,7,8-TCDD), and the site is considered the dominant source of 2,3,7,8-TCDD to the lower Passaic River and its environs. Several investigators have identified the ratio of 2,3,7,8-TCDD to total TCDD as a fingerprint for the site source. The present study presents data that establish polychlorinated dibenzodioxin/polychlorinated dibenzofuran (collectively, PCDD/F) congener and homolog fingerprints of soil and sump samples from the site. It then compares those fingerprints to the PCDD/F congener and homolog patterns in lower Passaic River sediments. The similarity of the patterns in lower Passaic River sediments to the site fingerprint indicates the site is the dominant source of the 2,3,7,8-TCDD in sediments within approximately the lower 14 miles of the lower Passaic River, excluding, for the purposes of the present discussion, Newark Bay. In addition, PCDD/F congener data indicate that the ratio of 1,3,7,8-TCDD to 2,3,7,8-TCDD is another marker of the site and corroborates the findings from the other fingerprints.

  8. Source model and ground shaking of the 2015 Gorkha, Nepal Mw7.8 earthquake

    NASA Astrophysics Data System (ADS)

    Wei, S.; Wang, T.; Lindsey, E. O.; Avouac, J. P.; Graves, R. W.; Hubbard, J.; Hill, E.; Barbot, S.; Tapponnier, P.; Karakas, C.; Helmberger, D. V.

    2015-12-01

    The 2015 Mw7.8 Gorkha, Nepal earthquake ruptured a previously locked portion of the Main Himalayan Thrust fault (MHT) that has not slipped in a large event since 1833 (Mw7.6). The earthquake was well recorded by geodetic (SAR, InSAR and GPS) and seismic instruments. In particular, high-rate (5Hz) GPS channels provide waveform records at local distances, with three stations located directly above the major asperities of the earthquake. Here we derive a kinematic rupture model of the earthquake by jointly inverting the seismic and geodetic data, using a Kostrov source time function with variable rise times. Our inversion result indicates that the earthquake had a weak initiation and ruptured unilaterally along strike towards the ESE, with an average rupture speed of 3.0km/s and total duration of ~60s. The preferred slip rate of the beginning portion of the rupture had a longer rise time compared with the strongest ruptures, which took place at ~22s and ~35s after the origin, located 30km to the northwest and 20km to the east of the Kathmandu valley, respectively. The horizontal vibration and amplification of ground shaking in the valley was well recorded by one of the GPS stations (NAST) and the accelerometric station (KANTP), with a dominant frequency of 0.25Hz. A simplified basin model with top shear wave speed of 250 m/s and geometry constrained by a previous micro-tremor study can largely explain the amplification and vibration, realized by 3D staggered-grid finite difference simulations. This study shows that ground shaking can be strongly affected by complexities of the rupture and velocity structure.

  9. Time-domain multimode dispersion measurement in a higher-order-mode fiber

    PubMed Central

    Cheng, Ji; Pedersen, Martin E. V.; Wang, Ke; Xu, Chris; Grüner-Nielsen, Lars; Jakobsen, Dan

    2012-01-01

    We present a new multimode dispersion measurement technique based on the time-of-flight method. The modal delay and group velocity dispersion of all excited modes in a few-mode fiber can be measured simultaneously by a tunable pulsed laser and a high speed sampling oscilloscope. A newly designed higher-order-mode fiber with large anomalous dispersion in the LP02 mode has been characterized using this method, and experimental results are in good agreement with the designed dispersion values. The demonstrated technique is significantly simpler to implement than the existing frequency-domain or interferometry-based methods. PMID:22297348

  10. Bisubstrate analogue inhibitors of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase: New design with improved properties

    SciTech Connect

    Shi, Genbin; Shaw, Gary; Liang, Yu-He; Subburaman, Priadarsini; Li, Yue; Wu, Yan; Yan, Honggao; Ji, Xinhua

    2012-07-11

    6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK), a key enzyme in the folate biosynthetic pathway, catalyzes the pyrophosphoryl transfer from ATP to 6-hydroxymethyl-7,8-dihydropterin. The enzyme is essential for microorganisms, is absent from humans, and is not the target for any existing antibiotics. Therefore, HPPK is an attractive target for developing novel antimicrobial agents. Previously, we characterized the reaction trajectory of HPPK-catalyzed pyrophosphoryl transfer and synthesized a series of bisubstrate analog inhibitors of the enzyme by linking 6-hydroxymethylpterin to adenosine through 2, 3, or 4 phosphate groups. Here, we report a new generation of bisubstrate analog inhibitors. To improve protein binding and linker properties of such inhibitors, we have replaced the pterin moiety with 7,7-dimethyl-7,8-dihydropterin and the phosphate bridge with a piperidine linked thioether. We have synthesized the new inhibitors, measured their K{sub d} and IC{sub 50} values, determined their crystal structures in complex with HPPK, and established their structure-activity relationship. 6-Carboxylic acid ethyl ester-7,7-dimethyl-7,8-dihydropterin, a novel intermediate that we developed recently for easy derivatization at position 6 of 7,7-dimethyl-7,8-dihydropterin, offers a much high yield for the synthesis of bisubstrate analogs than that of previously established procedure.

  11. Bisubstrate analogue inhibitors of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase: New design with improved properties

    PubMed Central

    Shi, Genbin; Shaw, Gary; Liang, Yu-He; Subburaman, Priadarsini; Li, Yue; Wu, Yan; Yan, Honggao; Ji, Xinhua

    2011-01-01

    6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK), a key enzyme in the folate biosynthetic pathway, catalyzes the pyrophosphoryl transfer from ATP to 6-hydroxymethyl-7,8-dihydropterin. The enzyme is essential for microorganisms, is absent from humans, and is not the target for any existing antibiotics. Therefore, HPPK is an attractive target for developing novel antimicrobial agents. Previously, we characterized the reaction trajectory of HPPK-catalyzed pyrophosphoryl transfer and synthesized a series of bisubstrate analog inhibitors of the enzyme by linking 6-hydroxymethylpterin to adenosine through 2, 3, or 4 phosphate groups. Here, we report a new generation of bisubstrate analog inhibitors. To improve protein binding and linker properties of such inhibitors, we have replaced the pterin moiety with 7,7-dimethyl-7,8-dihydropterin and the phosphate bridge with a piperidine linked thioether. We have synthesized the new inhibitors, measured their Kd and IC50 values, determined their crystal structures in complex with HPPK, and established their structure-activity relationship. 6-Carboxylic acid ethyl ester-7,7-dimethyl-7,8-dihydropterin, a novel intermediate that we developed recently for easy derivatization at position 6 of 7,7-dimethyl-7,8-dihydropterin, offers a much high yield for the synthesis of bisubstrate analogs than that of previously established procedure. PMID:22169600

  12. Wavelet Transform Based Higher Order Statistical Analysis of Wind and Wave Time Histories

    NASA Astrophysics Data System (ADS)

    Habib Huseni, Gulamhusenwala; Balaji, Ramakrishnan

    2016-06-01

    Wind, blowing on the surface of the ocean, imparts the energy to generate the waves. Understanding the wind-wave interactions is essential for an oceanographer. This study involves higher order spectral analyses of wind speeds and significant wave height time histories, extracted from European Centre for Medium-Range Weather Forecast database at an offshore location off Mumbai coast, through continuous wavelet transform. The time histories were divided by the seasons; pre-monsoon, monsoon, post-monsoon and winter and the analysis were carried out to the individual data sets, to assess the effect of various seasons on the wind-wave interactions. The analysis revealed that the frequency coupling of wind speeds and wave heights of various seasons. The details of data, analysing technique and results are presented in this paper.

  13. Discrete sliding mode control for robust tracking of higher order delay time systems with experimental application.

    PubMed

    Khandekar, A A; Malwatkar, G M; Patre, B M

    2013-01-01

    In this paper, a discrete time sliding mode controller (DSMC) is proposed for higher order plus delay time (HOPDT) processes. A sliding mode surface is selected as a function of system states and error and the tuning parameters of sliding mode controller are determined using dominant pole placement strategy. The condition for the existence of stable sliding mode is obtained by using Lyapunov function. The proposed method is applicable to HOPDT processes with oscillatory and integrating behavior, open loop instability or non-minimum phase characteristics and works satisfactory under the effect of parametric uncertainty. The method does not require reduced order model and provides simple way to design the controllers. The simulation and experimentation results show that the proposed method ensures desired tracking dynamics.

  14. Cancer mortality in workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Fingerhut, M.A.; Halperin, W.E.; Marlow, D.A.; Piacitelli, L.A.; Honchar, P.A.; Sweeney, M.H.; Greife, A.L.; Dill, P.A.; Steenland, K.; Suruda, A.J. )

    1991-01-24

    In both animal and epidemiologic studies, exposure to dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, or TCDD) has been associated with an increased risk of cancer. We conducted a retrospective cohort study of mortality among the 5172 workers at 12 plants in the United States that produced chemicals contaminated with TCDD. Occupational exposure was documented by reviewing job descriptions and by measuring TCDD in serum from a sample of 253 workers. Causes of death were taken from death certificates. Mortality from several cancers previously associated with TCDD (stomach, liver, and nasal cancers, Hodgkin's disease, and non-Hodgkin's lymphoma) was not significantly elevated in this cohort. Mortality from soft-tissue sarcoma was increased, but not significantly (4 deaths; standardized mortality ratio (SMR), 338; 95 percent confidence interval, 92 to 865). In the subcohort of 1520 workers with greater than or equal to 1 year of exposure and greater than or equal to 20 years of latency, however, mortality was significantly increased for soft-tissue sarcoma (3 deaths; SMR, 922; 95 percent confidence interval, 190 to 2695) and for cancers of the respiratory system (SMR, 142; 95 percent confidence interval, 103 to 192). Mortality from all cancers combined was slightly but significantly elevated in the overall cohort (SMR, 115; 95 percent confidence interval, 102 to 130) and was higher in the subcohort with greater than or equal to 1 year of exposure and greater than or equal to 20 years of latency (SMR, 146; 95 percent confidence interval, 121 to 176). This study of mortality among workers with occupational exposure to TCDD does not confirm the high relative risks reported for many cancers in previous studies. Conclusions about an increase in the risk of soft-tissue sarcoma are limited by small numbers and misclassification on death certificates.

  15. Higher Order Time Integration Schemes for the Unsteady Navier-Stokes Equations on Unstructured Meshes

    NASA Technical Reports Server (NTRS)

    Jothiprasad, Giridhar; Mavriplis, Dimitri J.; Caughey, David A.; Bushnell, Dennis M. (Technical Monitor)

    2002-01-01

    The efficiency gains obtained using higher-order implicit Runge-Kutta schemes as compared with the second-order accurate backward difference schemes for the unsteady Navier-Stokes equations are investigated. Three different algorithms for solving the nonlinear system of equations arising at each timestep are presented. The first algorithm (NMG) is a pseudo-time-stepping scheme which employs a non-linear full approximation storage (FAS) agglomeration multigrid method to accelerate convergence. The other two algorithms are based on Inexact Newton's methods. The linear system arising at each Newton step is solved using iterative/Krylov techniques and left preconditioning is used to accelerate convergence of the linear solvers. One of the methods (LMG) uses Richardson's iterative scheme for solving the linear system at each Newton step while the other (PGMRES) uses the Generalized Minimal Residual method. Results demonstrating the relative superiority of these Newton's methods based schemes are presented. Efficiency gains as high as 10 are obtained by combining the higher-order time integration schemes with the more efficient nonlinear solvers.

  16. Higher Order Time Integration Schemes for the Unsteady Navier-Stokes Equations on Unstructured Meshes

    NASA Technical Reports Server (NTRS)

    Jothiprasad, Giridhar; Mavriplis, Dimitri J.; Caughey, David A.

    2002-01-01

    The rapid increase in available computational power over the last decade has enabled higher resolution flow simulations and more widespread use of unstructured grid methods for complex geometries. While much of this effort has been focused on steady-state calculations in the aerodynamics community, the need to accurately predict off-design conditions, which may involve substantial amounts of flow separation, points to the need to efficiently simulate unsteady flow fields. Accurate unsteady flow simulations can easily require several orders of magnitude more computational effort than a corresponding steady-state simulation. For this reason, techniques for improving the efficiency of unsteady flow simulations are required in order to make such calculations feasible in the foreseeable future. The purpose of this work is to investigate possible reductions in computer time due to the choice of an efficient time-integration scheme from a series of schemes differing in the order of time-accuracy, and by the use of more efficient techniques to solve the nonlinear equations which arise while using implicit time-integration schemes. This investigation is carried out in the context of a two-dimensional unstructured mesh laminar Navier-Stokes solver.

  17. 7,8-Dihydroxyflavone, a Tropomyosin-Kinase Related Receptor B Agonist, Produces Fast-Onset Antidepressant-Like Effects in Rats Exposed to Chronic Mild Stress

    PubMed Central

    Chang, Hsin-An; Wang, Ying-Hsiu; Tung, Che-Se; Yeh, Chin-Bin

    2016-01-01

    Objective Brain-derived neurotrophic factor (BDNF) and its specific receptor, tropomyosin-related kinase (TrkB), play important roles in treating depression. In this experiment, we examined whether 7,8-dihydroxyflavone, a novel potent TrkB agonist, could reverse the behavioral and biochemical abnormalities induced by the chronic mild stress (CMS) paradigm in rats. Methods SD rats were exposed to a battery of stressors for 56 days. 7,8-dihydroxyflavone (5 and 20 mg/kg) were administered intraperitoneally during the last 28 days of the CMS paradigm. Rats were tested in sucrose consumption test (SCT), forced-swimming test (FST) and elevated T-maze (ETM). Serum corticosterone levels and hippocampal BDNF levels of the rats were measured. Results Four-week CMS on the rats induced their depression-like behavior in SCT. The CMS-reduced sucrose consumption was reversed starting from 7 days after the 7,8-dihydroxyflavone (20 mg/kg) treatment and remained across the subsequent treatment regime. 7,8-dihydroxyflavone, when given at 5 mg/kg for 3 weeks, reduced the immobility time in the FST in the CMS-subjected rats. Additionally, the 4-week treatment with 7,8-dihydroxyflavone (20 mg/kg) attenuated the CMS-induced increase in anxiety-like behavior in the ETM. For the CMS-subjected rats, 7,8-dihydroxyflavone treatment dose-dependently reduced their serum corticosterone levels but increased their hippocampal BDNF levels only at 5 mg/kg. Conclusion 7,8-dihydroxyflavone was beneficial for both depression and anxiety-like behaviors, and may exert fast-onset antidepressant effects. This provides a new insight into the pharmacological management of depression. PMID:27757132

  18. Transcriptional profiling of rat hypothalamus response to 2,3,7,8-tetrachlorodibenzo-ρ-dioxin.

    PubMed

    Houlahan, Kathleen E; Prokopec, Stephenie D; Moffat, Ivy D; Lindén, Jere; Lensu, Sanna; Okey, Allan B; Pohjanvirta, Raimo; Boutros, Paul C

    2015-02-01

    In some mammals, halogenated aromatic hydrocarbon (HAH) exposure causes wasting syndrome, defined as significant weight loss associated with lethal outcomes. The most potent HAH in causing wasting is 2,3,7,8-tetrachlorodibenzo-ρ-dioxin (TCDD), which exerts its toxic effects through the aryl hydrocarbon receptor (AHR). Since TCDD toxicity is thought to predominantly arise from dysregulation of AHR-transcribed genes, it was hypothesized that wasting syndrome is a result of to TCDD-induced dysregulation of genes involved in regulation of food-intake. As the hypothalamus is the central nervous systems' regulatory center for food-intake and energy balance. Therefore, mRNA abundances in hypothalamic tissue from two rat strains with widely differing sensitivities to TCDD-induced wasting syndrome: TCDD-sensitive Long-Evans rats and TCDD-resistant Han/Wistar rats, 23h after exposure to TCDD (100μg/kg) or corn oil vehicle. TCDD exposure caused minimal transcriptional dysregulation in the hypothalamus, with only 6 genes significantly altered in Long-Evans rats and 15 genes in Han/Wistar rats. Two of the most dysregulated genes were Cyp1a1 and Nqo1, which are induced by TCDD across a wide range of tissues and are considered sensitive markers of TCDD exposure. The minimal response of the hypothalamic transcriptome to a lethal dose of TCDD at an early time-point suggests that the hypothalamus is not the predominant site of initial events leading to hypophagia and associated wasting. TCDD may affect feeding behaviour via events upstream or downstream of the hypothalamus, and further work is required to evaluate this at the level of individual hypothalamic nuclei and subregions.

  19. Proposed occupational exposure limit for 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Leung, H.W.; Murray, F.J.; Paustenbach, D.J.

    1988-09-01

    One contaminant produced unintentionally during the manufacture of chlorophenols and phenoxy herbicides is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The resulting TCDD-containing wastes have been detected at many hazardous waste sites which in recent years have been in the process of remediation. Concerns about worker exposure to TCDD-contaminated soil (dust) during remediation of hazardous waste sites have produced a need for an occupational exposure limit (OEL) for TCDD. The animal toxicology data and human experience with TCDD are reviewed, and an occupational exposure limit for TCDD is proposed. The animal data support risk estimations which are based on TCDD as a nongenotoxic carcinogen. Studies on human populations have failed to demonstrate clearly any significant long-term health effects at levels to which humans have been exposed. The data indicate that an 8-hr time-weighted average limit of 2 ng/m3 is appropriate, and the associated risk would be consistent with other carcinogens at their corresponding OELs. A preliminary OEL of 0.2 ng/m3 (200 pg/m3) is recommended, however, in light of other sources of exposure because of TCDD's ubiquitousness in the environment, its unclear mechanism of action, and its rather long biological half-life in humans. This limit provides an ample margin of safety to prevent chloracne following repeated, acute exposure, and it addresses those chronic effects of TCDD observed in animal studies as well as those observed after accidental human exposure. The resulting body burden caused by chronic exposure to TCDD at the proposed OEL is examined. Its toxicological significance is compared with human tissue data and with other similarly persistent chemicals. 74 references.

  20. Pulse transmission receiver with higher-order time derivative pulse generator

    DOEpatents

    Dress, Jr., William B.; Smith, Stephen F.

    2003-08-12

    Systems and methods for pulse-transmission low-power communication modes are disclosed. A pulse transmission receiver includes: a front-end amplification/processing circuit; a synchronization circuit coupled to the front-end amplification/processing circuit; a clock coupled to the synchronization circuit; a trigger signal generator coupled to the clock; and at least one higher-order time derivative pulse generator coupled to the trigger signal generator. The systems and methods significantly reduce lower-frequency emissions from pulse transmission spread-spectrum communication modes, which reduces potentially harmful interference to existing radio frequency services and users and also simultaneously permit transmission of multiple data bits by utilizing specific pulse shapes.

  1. Numerical time dependent sheet cavitation simulations using a higher order panel method

    NASA Astrophysics Data System (ADS)

    Dekoninggans, H. J.

    1994-03-01

    This thesis deals with sheet cavitation. The investigation is aimed at profile design with respect to cavitation control. At present it is possible to predict the shape of cavities on an arbitrary two-dimensional profile in stationary flows. To compute the flow around an arbitrary profile, a higher order three-dimensional panel method program has been developed. The main algorithm used in this program is based on a special case of Green's theorem, called 'de Morino formulation'. This computer program (flow program) can calculate the potential on the body and the velocities at the surface of the body or in the flow field. A theoretical method is developed for time simulation of unsteady sheet cavitation. Numerical simulations of the flow around profiles and of cavitation have been carried out. The numerical results of the panel methods have been compared with other calculations of the two-dimensional flow around profiles and of three-dimensional flow around a sphere and a wing. Simulations of the growth of sheet cavitation on a foil have also been carried out. The conclusion is that higher order panel methods are more accurate than the zero order methods. Further refinement of the Kutta condition is required, however.

  2. Fission Multiplicity Detection with Temporal Gamma-Neutron Discrimination from Higher-Order Time Correlation Statistics

    SciTech Connect

    Oberer, R.B.

    2002-11-12

    The current practice of nondestructive assay (NDA) of fissile materials using neutrons is dominated by the {sup 3}He detector. This has been the case since the mid 1980s when Fission Multiplicity Detection (FMD) was replaced with thermal well counters and neutron multiplicity counting (NMC). The thermal well counters detect neutrons by neutron capture in the {sup 3}He detector subsequent to moderation. The process of detection requires from 30 to 60 {micro}s. As will be explained in Section 3.3 the rate of detecting correlated neutrons (signal) from the same fission are independent of this time but the rate of accidental correlations (noise) are proportional to this time. The well counters are at a distinct disadvantage when there is a large source of uncorrelated neutrons present from ({alpha}, n) reactions for example. Plastic scintillating detectors, as were used in FMD, require only about 20 ns to detect neutrons from fission. One thousandth as many accidental coincidences are therefore accumulated. The major problem with the use of fast-plastic scintillation detectors, however, is that both neutrons and gamma rays are detected. The pulses from the two are indistinguishable in these detectors. For this thesis, a new technique was developed to use higher-order time correlation statistics to distinguish combinations of neutron and gamma ray detections in fast-plastic scintillation detectors. A system of analysis to describe these correlations was developed based on simple physical principles. Other sources of correlations from non-fission events are identified and integrated into the analysis developed for fission events. A number of ratios and metric are identified to determine physical properties of the source from the correlations. It is possible to determine both the quantity being measured and detection efficiency from these ratios from a single measurement without a separate calibration. To account for detector dead-time, an alternative analytical technique

  3. Lack of contribution of covalent benzo[a]pyrene-7,8-quinone-DNA adducts in benzo[a]pyrene-induced mouse lung tumorigenesis.

    PubMed

    Nesnow, Stephen; Nelson, Garret; Padgett, William T; George, Michael H; Moore, Tanya; King, Leon C; Adams, Linda D; Ross, Jeffrey A

    2010-07-30

    Benzo[a]pyrene (B[a]P) is a potent human and rodent lung carcinogen. This activity has been ascribed in part to the formation of anti-trans-7,8-dihydroxy-7,8-dihydroB[a]P-9,10-epoxide (BPDE)-DNA adducts. Other carcinogenic mechanisms have been proposed: (1) the induction of apurinic sites from radical cation processes, and (2) the metabolic formation of B[a]P-7,8-quinone (BPQ) that can form covalent DNA adducts or reactive oxygen species which can damage DNA. The studies presented here sought to examine the role of stable BPQ-DNA adducts in B[a]P-induced mouse lung tumorigenesis. Male strain A/J mice were injected intraperitoneally once with BPQ or trans-7,8-dihydroxy-7,8-dihydroB[a]P (BP-7,8-diol) at 30, 10, 3, or 0mg/kg. Lungs and livers were harvested after 24h, the DNA extracted and subjected to (32)P-postlabeling analysis. Additional groups of mice were dosed once with BPQ or BP-7,8-diol each at 30 mg/kg and tissues harvested 48 and 72 h later, or with B[a]P (50mg/kg, a tumorigenic dose) and tissues harvested 72 h later. No BPQ or any other DNA adducts were observed in lung or liver tissues 24, 48, or 72 h after the treatment with 30 mg/kg BPQ. BP-7,8-diol gave BPDE-DNA adducts at all time points in both tissues and B[a]P treatment gave BPDE-DNA adducts in the lung. In each case, no BPQ-DNA adducts were detected. Mouse body weights significantly decreased over time after BPQ or BP-7,8-diol treatments suggesting that systemic toxicity was induced by both agents. Model studies with BPQ and N-acetylcysteine suggested that BPQ is rapidly inactivated by sulfhydryl-containing compounds and not available for DNA adduction. We conclude that under these treatment conditions BPQ does not form stable covalent DNA adducts in the lungs or livers of strain A/J mice, suggesting that stable BPQ-covalent adducts are not a part of the complex of mechanisms involved in B[a]P-induced mouse lung tumorigenesis.

  4. HEALTH RISK ASSESSMENT APPROACH FOR 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (1985)

    EPA Science Inventory

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is one of the most toxic and environmentally stable pollutants. In addition to various toxic effects, TCDD has been found to cause teratogenic, fetocidal, reproductive and carcinogenic effects in animals. In humans it adversely affects v...

  5. The American Indian Social Studies Curriculum Activity Guide, Grades 7-8.

    ERIC Educational Resources Information Center

    Stutzman, Esther

    An attempt to add substance to history, the curriculum guide for grades 7-8 presents in 12 culture guides information on American Indians for teachers to use as supplement materials to social studies texts. Each culture guide is accompanied with a teacher guide offering activities or discussion/quiz questions. Topics of culture guides encompass…

  6. ANALYSIS OF 2,3,7,8-TCDD TUMOR PROMOTION ACTIVITY AND ITS RELATIONSHIP TO CANCER

    EPA Science Inventory

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has a high estimated cancer potency in animals which has been reasoned to imply that TCDD might be carcinogenic to man. The animal cancer data show that TCDD can act in a solitary manner causing tumors without the participation of other ...

  7. The use of Toll-like receptor 7/8 agonists as vaccine adjuvants.

    PubMed

    Vasilakos, John P; Tomai, Mark A

    2013-07-01

    Small molecule Toll-like receptor (TLR) 7/8 agonists have demonstrated potential as vaccine adjuvants, since they directly activate APCs and can enhance both humoral and cellular immune responses, especially Th1 responses. Although the natural ligands for TLR7 and TLR8 are ssRNA, the vast majority of vaccine studies performed thus far have been performed with synthetic small molecule imidazoquinolines, such as imiquimod and resiquimod. Despite the approved clinical use of the topical TLR7 agonist, imiquimod (Aldara(®) Imiquimod 5% cream; 3M, MN, USA), for external genital warts, superficial basal cell carcinoma and actinic keratosis, no vaccines using TLR7, TLR8 or TLR7/8 agonists have progressed beyond early-phase clinical studies thus far. This review will highlight the nonclinical and clinical studies that indicate promise for TLR7/8 ligands as vaccine adjuvants, reasons for inconsistent results thus far, problems with current technology and potential paths forward for TLR7/8 agonists as vaccine adjuvants.

  8. Toxics in My Home? You Bet! Curriculum on Household Toxics for Grades 7-8.

    ERIC Educational Resources Information Center

    Purin, Gina; And Others

    This curriculum consists of a one-week course of study designed to introduce students in grades 7-8 to (or increase their awareness of) toxic substances commonly found in the home. It includes an introduction/conceptual framework, four lessons, a unit test, and appendices. Each lesson consists of a statement of purpose, objectives,…

  9. 36 CFR 7.8 - Sequoia and Kings Canyon National Parks.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Sequoia and Kings Canyon... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.8 Sequoia and Kings Canyon... and Kings Canyon National Parks. (i) Facilities. (a) Subject to the provisions of paragraph...

  10. 36 CFR 7.8 - Sequoia and Kings Canyon National Parks.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Sequoia and Kings Canyon... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.8 Sequoia and Kings Canyon... and Kings Canyon National Parks. (i) Facilities. (a) Subject to the provisions of paragraph...

  11. 36 CFR 7.8 - Sequoia and Kings Canyon National Parks.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Sequoia and Kings Canyon... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.8 Sequoia and Kings Canyon... and Kings Canyon National Parks. (i) Facilities. (a) Subject to the provisions of paragraph...

  12. Close-up of 7/8' gold-plated liquid oxygen post plug

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Engineers are investigating the possibility that a 7/8' gold- plated liquid oxygen post plug became dislodged and created three small holes in the liquid hydrogen tubes inside the nozzle on main engine No. 3 on Space Shuttle Columbia. The holes caused a hydrogen leak during the STS-93 launch of Columbia on July 23.

  13. The 7/8 Piano Keyboard: An Attractive Alternative for Small-Handed Players

    ERIC Educational Resources Information Center

    Wristen, Brenda; Hallbeck, M. Susan

    2009-01-01

    This study examines whether the use of a 7/8 keyboard contributes to the physical ease of small-handed pianists in comparison to the conventional piano keyboard. A secondary research question focuses on the progression of physical ease in making the transition from one keyboard to the other. For the purposes of this study, the authors stipulated…

  14. 39 CFR 7.8 - Open meetings, Freedom of Information, and Privacy of Information.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Open meetings, Freedom of Information, and Privacy... THE U.S. POSTAL SERVICE PUBLIC OBSERVATION (ARTICLE VII) § 7.8 Open meetings, Freedom of Information..., the Government in the Sunshine Act, govern in the case of any request under the Freedom of...

  15. Statistical monitoring of aftershock sequences: a case study of the 2015 Mw7.8 Gorkha, Nepal, earthquake

    NASA Astrophysics Data System (ADS)

    Ogata, Yosihiko; Tsuruoka, Hiroshi

    2016-03-01

    Early forecasting of aftershocks has become realistic and practical because of real-time detection of hypocenters. This study illustrates a statistical procedure for monitoring aftershock sequences to detect anomalies to increase the probability gain of a significantly large aftershock or even an earthquake larger than the main shock. In particular, a significant lowering (relative quiescence) in aftershock activity below the level predicted by the Omori-Utsu formula or the epidemic-type aftershock sequence model is sometimes followed by a large earthquake in a neighboring region. As an example, we detected significant lowering relative to the modeled rate after approximately 1.7 days after the main shock in the aftershock sequence of the Mw7.8 Gorkha, Nepal, earthquake of April 25, 2015. The relative quiescence lasted until the May 12, 2015, M7.3 Kodari earthquake that occurred at the eastern end of the primary aftershock zone. Space-time plots including the transformed time can indicate the local places where aftershock activity lowers (the seismicity shadow). Thus, the relative quiescence can be hypothesized to be related to stress shadowing caused by probable slow slips. In addition, the aftershock productivity of the M7.3 Kodari earthquake is approximately twice as large as that of the M7.8 main shock.

  16. A novel fast gas chromatography method for higher time resolution measurements of speciated monoterpenes in air

    NASA Astrophysics Data System (ADS)

    Jones, C. E.; Kato, S.; Nakashima, Y.; Kajii, Y.

    2014-05-01

    Biogenic emissions supply the largest fraction of non-methane volatile organic compounds (VOC) from the biosphere to the atmospheric boundary layer, and typically comprise a complex mixture of reactive terpenes. Due to this chemical complexity, achieving comprehensive measurements of biogenic VOC (BVOC) in air within a satisfactory time resolution is analytically challenging. To address this, we have developed a novel, fully automated Fast Gas Chromatography (Fast-GC) based technique to provide higher time resolution monitoring of monoterpenes (and selected other C9-C15 terpenes) during plant emission studies and in ambient air. To our knowledge, this is the first study to apply a Fast-GC based separation technique to achieve quantification of terpenes in ambient air. Three chromatography methods have been developed for atmospheric terpene analysis under different sampling scenarios. Each method facilitates chromatographic separation of selected BVOC within a significantly reduced analysis time compared to conventional GC methods, whilst maintaining the ability to quantify individual monoterpene structural isomers. Using this approach, the C9-C15 BVOC composition of single plant emissions may be characterised within a 14.5 min analysis time. Moreover, in-situ quantification of 12 monoterpenes in unpolluted ambient air may be achieved within an 11.7 min chromatographic separation time (increasing to 19.7 min when simultaneous quantification of multiple oxygenated C9-C10 terpenoids is required, and/or when concentrations of anthropogenic VOC are significant). These analysis times potentially allow for a twofold to fivefold increase in measurement frequency compared to conventional GC methods. Here we outline the technical details and analytical capability of this chromatographic approach, and present the first in-situ Fast-GC observations of 6 monoterpenes and the oxygenated BVOC (OBVOC) linalool in ambient air. During this field deployment within a suburban forest

  17. Development and field validation of a multimedia exposure assessment model for waste load allocation in aquatic ecosystems: Application to 2,3,7,8-tetrachlorodibenzo-p-dioxin and 2,3,7,8-tetrachlorodibenzofuran in the Fraser River Watershed

    SciTech Connect

    Gobas, F.A.P.; Pasternak, J.P.; Lien, K.; Duncan, R.K.

    1998-08-15

    Knowledge of the relationship between contaminant emissions and ambient concentrations is crucial in achieving environmental quality objectives. This paper reports the development and field validation of EcoFate, a time dependent multimedia mass balance simulation model of the environmental distribution food-chain accumulation of organic contaminants in aquatic ecosystems. The purpose of the model is to present a methodology for deriving maximum daily-loading estimates in accordance with environmental quality objectives for a variety of aquatic ecosystems impacted by emissions from one or several point or nonpoint sources. The application of the model to multiple, time-varying pulp and paper mill discharges of 2,3,7,8-tetrachlorodibenzo-p-dioxin and 2,3,7,8-tetrachlorodibenzofuran in the Fraser-Thompson River system from 1988 to 1995 is demonstrated. The ability of the model to predict chemical concentrations in various environmental media and organisms resulting from chemical emissions is tested against field data collected over a 7 year period. The results include (1) a comparison of observed and predicted concentrations, (2) an assessment of uncertainty, and (3) a test of the model`s temporal response to changes in contaminant loadings. The application of the model for the derivation of maximum daily loadings for multiple point sources in watersheds is illustrated.

  18. Automated Determination of P-Wave Arrival Times Using Higher Order Statistics

    NASA Astrophysics Data System (ADS)

    Kueperkoch, L.; Meier, T.; Friederich, W.

    2009-04-01

    Due to the continuously increasing amount of digital, seismological data, automatic localication of seismic events becomes more and more important. The main difficulty is the automatic identification and precise determination of P- and S-wave arrival times. Here we present an algorithm based on higher order statistics for the automated determination of P-onsets of local and regional seismic events. Using the 4th central moment, a characteristic function is calculated, on which the "picker" is applied. Important is the automatic estimation of the quality of the P-onset. In order to get rid off false P-readings, several algorithms are applied to single station as well as to the finishing multy station processing. The robustness and reliability of the automatic has been tested on a very heterogeneous data set of the temporary, regional seismological network EGELADOS, using manual P-readings, which serve as reference picks, as well as by a comparison with the Allen- and the Baer- & Kradolfer-picker. The accuracy and the speed of the presented automatic makes this processing scheme to an option for the implementation into a near-real time processing, e.g. for earthquake early-warning systems.

  19. A model to evaluate past exposure to 2,3,7,8-TCDD.

    PubMed

    Pinsky, P F; Lorber, M N

    1998-01-01

    Data from several studies suggest that concentrations of dioxins rose in the environment from the 1930s to about the 1960s/70s and have been declining over the last decade or two. The most direct evidence of this trend comes from lake core sediments, which can be used to estimate past atmospheric depositions of dioxins. The primary source of human exposure to dioxins is through the food supply. The pathway relating atmospheric depositions to concentrations in food is quite complex, and accordingly, it is not known to what extent the trend in human exposure mirrors the trend in atmospheric depositions. This paper describes an attempt to statistically reconstruct the pattern of past human exposure to the most toxic dioxin congener, 2,3,7,8-TCDD (abbreviated TCDD), through use of a simple pharmacokinetic (PK) model which included a time-varying TCDD exposure dose. This PK model was fit to TCDD body burden data (i.e., TCDD concentrations in lipid) from five U.S. studies dating from 1972 to 1987 and covering a wide age range. A Bayesian statistical approach was used to fit TCDD exposure; model parameters other than exposure were all previously known or estimated from other data sources. The primary results of the analysis are as follows: (1) use of a time-varying exposure dose provided a far better fit to the TCDD body burden data than did using a dose that was constant over time; this is strong evidence that exposure to TCDD has, in fact, varied during the 20th century, (2) the year of peak TCDD exposure was estimated to be in the late 1960s, which coincides with peaks found in sediment core studies, (3) modeled average exposure doses during these peak years was estimated at 1.4-1.9 pg TCDD/kg-day, and (4) modeled exposure doses of TCDD for the late 1980s of less than 0.10 pg TCDD/kg-day correlated well with recent estimates of exposure doses around 0.17 pg TCDD/kg-day (recent estimates are based on food concentrations combined with food ingestion rates; food is

  20. Effects on noise properties of GPS time series caused by higher-order ionospheric corrections

    NASA Astrophysics Data System (ADS)

    Jiang, Weiping; Deng, Liansheng; Li, Zhao; Zhou, Xiaohui; Liu, Hongfei

    2014-04-01

    Higher-order ionospheric (HOI) effects are one of the principal technique-specific error sources in precise global positioning system (GPS) analysis. These effects also influence the non-linear characteristics of GPS coordinate time series. In this paper, we investigate these effects on coordinate time series in terms of seasonal variations and noise amplitudes. Both power spectral techniques and maximum likelihood estimators (MLE) are used to evaluate these effects quantitatively and qualitatively. Our results show an overall improvement for the analysis of global sites if HOI effects are considered. We note that the noise spectral index that is used for the determination of the optimal noise models in our analysis ranged between -1 and 0 both with and without HOI corrections, implying that the coloured noise cannot be removed by these corrections. However, the corrections were found to have improved noise properties for global sites. After the corrections were applied, the noise amplitudes at most sites decreased, among which the white noise amplitudes decreased remarkably. The white noise amplitudes of up to 81.8% of the selected sites decreased in the up component, and the flicker noise of 67.5% of the sites decreased in the north component. Stacked periodogram results show that, no matter whether the HOI effects are considered or not, a common fundamental period of 1.04 cycles per year (cpy), together with the expected annual and semi-annual signals, can explain all peaks of the north and up components well. For the east component, however, reasonable results can be obtained only based on HOI corrections. HOI corrections are useful for better detecting the periodic signals in GPS coordinate time series. Moreover, the corrections contributed partly to the seasonal variations of the selected sites, especially for the up component. Statistically, HOI corrections reduced more than 50% and more than 65% of the annual and semi-annual amplitudes respectively at the

  1. Higher-order time integration of Coulomb collisions in a plasma using Langevin equations

    SciTech Connect

    Dimits, A.M.; Cohen, B.I.; Caflisch, R.E.; Rosin, M.S.; Ricketson, L.F.

    2013-06-01

    The extension of Langevin-equation Monte-Carlo algorithms for Coulomb collisions from the conventional Euler–Maruyama time integration to the next higher order of accuracy, the Milstein scheme, has been developed, implemented, and tested. This extension proceeds via a formulation of the angular scattering directly as stochastic differential equations in the fixed-frame spherical-coordinate velocity variables. Results from the numerical implementation show the expected improvement [O(Δt) vs. O(Δt{sup 1/2})] in the strong convergence rate both for the speed |v| and angular components of the scattering. An important result is that this improved convergence is achieved for the angular component of the scattering if and only if the “area-integral” terms in the Milstein scheme are included. The resulting Milstein scheme is of value as a step towards algorithms with both improved accuracy and efficiency. These include both algorithms with improved convergence in the averages (weak convergence) and multi-time-level schemes. The latter have been shown to give a greatly reduced cost for a given overall error level when compared with conventional Monte-Carlo schemes, and their performance is improved considerably when the Milstein algorithm is used for the underlying time advance versus the Euler–Maruyama algorithm. A new method for sampling the area integrals is given which is a simplification of an earlier direct method and which retains high accuracy. This method, while being useful in its own right because of its relative simplicity, is also expected to considerably reduce the computational requirements for the direct conditional sampling of the area integrals that is needed for adaptive strong integration.

  2. Higher-order time integration of Coulomb collisions in a plasma using Langevin equations

    SciTech Connect

    Dimits, A. M.; Cohen, B. I.; Caflisch, R. E.; Rosin, M. S.; Ricketson, L. F.

    2013-02-08

    The extension of Langevin-equation Monte-Carlo algorithms for Coulomb collisions from the conventional Euler-Maruyama time integration to the next higher order of accuracy, the Milstein scheme, has been developed, implemented, and tested. This extension proceeds via a formulation of the angular scattering directly as stochastic differential equations in the two fixed-frame spherical-coordinate velocity variables. Results from the numerical implementation show the expected improvement [O(Δt) vs. O(Δt1/2)] in the strong convergence rate both for the speed |v| and angular components of the scattering. An important result is that this improved convergence is achieved for the angular component of the scattering if and only if the “area-integral” terms in the Milstein scheme are included. The resulting Milstein scheme is of value as a step towards algorithms with both improved accuracy and efficiency. These include both algorithms with improved convergence in the averages (weak convergence) and multi-time-level schemes. The latter have been shown to give a greatly reduced cost for a given overall error level when compared with conventional Monte-Carlo schemes, and their performance is improved considerably when the Milstein algorithm is used for the underlying time advance versus the Euler-Maruyama algorithm. A new method for sampling the area integrals is given which is a simplification of an earlier direct method and which retains high accuracy. Lastly, this method, while being useful in its own right because of its relative simplicity, is also expected to considerably reduce the computational requirements for the direct conditional sampling of the area integrals that is needed for adaptive strong integration.

  3. Higher-order time integration of Coulomb collisions in a plasma using Langevin equations

    DOE PAGES

    Dimits, A. M.; Cohen, B. I.; Caflisch, R. E.; Rosin, M. S.; Ricketson, L. F.

    2013-02-08

    The extension of Langevin-equation Monte-Carlo algorithms for Coulomb collisions from the conventional Euler-Maruyama time integration to the next higher order of accuracy, the Milstein scheme, has been developed, implemented, and tested. This extension proceeds via a formulation of the angular scattering directly as stochastic differential equations in the two fixed-frame spherical-coordinate velocity variables. Results from the numerical implementation show the expected improvement [O(Δt) vs. O(Δt1/2)] in the strong convergence rate both for the speed |v| and angular components of the scattering. An important result is that this improved convergence is achieved for the angular component of the scattering if andmore » only if the “area-integral” terms in the Milstein scheme are included. The resulting Milstein scheme is of value as a step towards algorithms with both improved accuracy and efficiency. These include both algorithms with improved convergence in the averages (weak convergence) and multi-time-level schemes. The latter have been shown to give a greatly reduced cost for a given overall error level when compared with conventional Monte-Carlo schemes, and their performance is improved considerably when the Milstein algorithm is used for the underlying time advance versus the Euler-Maruyama algorithm. A new method for sampling the area integrals is given which is a simplification of an earlier direct method and which retains high accuracy. Lastly, this method, while being useful in its own right because of its relative simplicity, is also expected to considerably reduce the computational requirements for the direct conditional sampling of the area integrals that is needed for adaptive strong integration.« less

  4. Deep Upper Mantle Anisotropy from SKS Splitting Delay Times and Higher Mode Surface Waves

    NASA Astrophysics Data System (ADS)

    Yuan, K.; Beghein, C.; Davis, P. M.

    2014-12-01

    The splitting of SKS waves is widely used to study mantle anisotropy and to get insight on Earth's dynamic interior. However, while SKS splitting is an unambiguous signature of anisotropy, it cannot be used directly to infer the depth distribution of the anisotropy because the dealy times between the two polarization directions result from integrated measurements along quasi-vertical paths between the core-mantle boundary and the surface. SKS splitting data are generally interpreted in terms of olivine lattice preferred orientation in the uppermost 250 km of the mantle. There is, nevertheless, growing evidence from regional studies that the splitting may contain significant contributions from greater depths. In addition, SKS delay times are strongly under predicted by tomographic models of azimuthal anisotropy derived from fundamentqal mode surface waves. These models typically display anisotropy only in the 250 km of the mantle because fundamental mode surface wave data have little sensitivity to structure below that depth. For example, we calculated predictions of SKS splitting using the global azimuthal anisotropy model of Debayle et al. (2005), and found a global delay times distributon with a median of 0.4 s, compared to 1.1 s for the global station-averaged SKS splitting database compiled by Becker et al. (2012). This discrepancy may indicate that seismic anisotropy is present at greater depths. In this work, we analyzed a new global 3-D model of azimuthal anisotropy (Yuan and Beghein, 2013) that was obtained from the inversion of higher modes surface wave phase velocity data with unprecedented sensitivity to the top 1000 km of the mantle. While this model is comparable to previous models in the uppermost mantle, it also displays anisotropy amplitudes of about 1% below 250 km depth and a complex 3-D pattern of fast axes directions down to 800 km depth. The predicted SKS delay times calculated using this new model have a median of 0.75 s, which is in much

  5. Renewing Quality Assurance at a Time of Turbulence: An Attempt to Reenergise Quality in Australian Higher Education

    ERIC Educational Resources Information Center

    Shah, Mahsood; Nair, Chenicheri Sid

    2011-01-01

    The renewal of quality assurance in Australian higher education comes at a time when the higher education sectors in Australia and around the world are experiencing a number of key challenges. These include: ongoing decline in public funding of universities; the massification of higher education and demand for it during global recession;…

  6. What Is Going on in Higher Education? Is It Time for a Change?

    ERIC Educational Resources Information Center

    Hackman, Judith Dozier

    1992-01-01

    The president of the Association for the Study of Higher Education identifies four powerful forces causing disarray and turbulence in higher education: (1) increasing gender equality, (2) increasing globalism, (3) increasing multiculturalism, and (4) expanding technology. It is concluded that higher education needs to gather its forces, shift its…

  7. Association of Matrix Metalloproteinases -7, -8 and -9 and TIMP -1 with Disease Severity in Acute Pancreatitis. A Cohort Study

    PubMed Central

    Nukarinen, Eija; Lindström, Outi; Kuuliala, Krista; Kylänpää, Leena; Pettilä, Ville; Puolakkainen, Pauli; Kuuliala, Antti; Hämäläinen, Mari; Moilanen, Eeva; Repo, Heikki; Hästbacka, Johanna

    2016-01-01

    Objectives Several biomarkers for early detection of severe acute pancreatitis (SAP) have been presented. Matrix metalloproteinases (MMP) and their tissue inhibitors (TIMP) are released early in inflammation. We aimed to assess levels of MMP-7, -8, -9 and TIMP-1 in acute pancreatitis (AP) and explore their ability to detect disease severity. Our second aim was to find an association between MMPs, TIMP and creatinine. Methods We collected plasma samples for MMP-7, -8, -9 and TIMP-1 analyses from 176 patients presenting within 96 h from onset of acute pancreatitis (AP) symptoms. We used samples from 32 control subjects as comparison. The revised Atlanta Classification was utilised to assess severity of disease. Receiver operating characteristic curve analysis and Spearman´s Rho-test were utilised for statistical calculations. Results Compared with controls, patients showed higher levels of all studied markers. MMP-8 was higher in moderately severe AP than in mild AP (p = 0.005) and MMP-8, -9 and TIMP-1 were higher in severe than in mild AP (p<0.001, p = 0.005 and p = 0.019). MMP-8 detected SAP with an AUC of 0.939 [95% CI 0.894–0.984], LR+ 9.03 [5.30–15.39]. MMP-8, -9 and TIMP-1 failed to discern moderately severe AP from SAP. MMP-7 was not different between patient groups. MMP-7 and TIMP-1 correlated weakly with creatinine (Rho = 0.221 and 0.243). MMP-8 might be a useful biomarker in early detection of SAP. PMID:27561093

  8. Part-Time Students and Part-Time Study in Higher Education in the UK: Strand 2--A Survey of the Issues Facing Institutions

    ERIC Educational Resources Information Center

    Boorman, Susan; Brown, Nigel; Payne, Philip; Ramsden, Brian

    2006-01-01

    This is the report on part-time study in UK higher education institutions (HEIs) for Universities UK and GuildHE (previously SCOP) from Nigel Brown Associates. It forms Strand 2 of the wider research into part-time higher education commissioned by Universities UK and GuildHE using quantitative data not available from published sources and…

  9. Chemical shift assignments of the fibronectin III like domains 7-8 of type VII collagen.

    PubMed

    Hermsdorf, Ulrike; Seeger, Karsten

    2016-04-01

    Type VII collagen (Col7) is important for skin stability. This is underlined by the severe skin blistering phenotype in the Col7 related diseases dystrophic epidermolysis bullosa and epidermolysis bullosa acquisita (EBA). Col7 has a large N-terminal non-collagenous domain (NC1) that is followed by the triple helical collagenous domain. The NC1 domain has subdomains with homology to adhesion molecules and mediates important interactions within the extracellular matrix. An 185 amino acid long part of the NC1-subdomain termed fibronectin III like domains 7 and 8 (FNIII7-8) was investigated. Antibodies against this region are pathogenic in a mouse model of EBA and one reported missense mutations of Col7 lies within these domains. The nearly complete NMR resonance assignment of recombinant FNIII7-8 of Col7 is reported. PMID:26364055

  10. Earthquake Forecasts for Gorkha Immediately Following the 25th April, M=7.8 Mainshock

    NASA Astrophysics Data System (ADS)

    Segkou, M.; Parsons, T.

    2015-12-01

    The M-7.8 Gorkha (Nepal) earthquake on the 25th April, 2015 has shaken the central Himalayan front and immediately raised concerns for the severity of future triggered earthquakes. Here, we implement standard and innovative forecast models to predict the spatio-temporal distribution of triggered events. Key challenges addressed are: 1) the limited information on early aftershocks, 2) the low-productivity aftershock sequence in the near-source area, 3) the off-fault (>250 km) triggered events exemplified by the M=5.4 Xegar event, 3 hrs after the mainshock. We apply short-term empirical/statistical ETAS and physical forecast models, the latter based on the combination of rate/state friction law and Coulomb stresses. Within the physics-based model implementation we seek to evaluate the uncertainty related with the rupture style of triggered events by considering: 1) the geometry of active structures, 2) optimally oriented for failure faults and 3) all-potential faults described by the total stress field. The latter is represented by the full stress tensor before and after the mainshock and our analysis suggests that the preseismic stress magnitudes are still sufficient to cause earthquakes even after modification by the mainshock. The above remark reveals that there are no "stress shadows" affecting the spatial distribution of near-field aftershocks. It is also noted that the method allows for an a-priori determination of the rupture plan of the M=7.3 event, within the limit of uncertainty (20˚). The results show that: (1) ETAS models underestimate the number of observed events, since they heavily base their good performance in small magnitude earthquakes, not available in the first few weeks after the mainshock, (2) far field triggered events are captured only by physics-based forecasts, and (3) the total stress method improves the predictability of larger magnitude events. We conclude that frontier regions benefit from the implementation of physics-based models

  11. 7.8GHz High power generation and extraction with a dielectric-loaded waveguide.

    SciTech Connect

    Conde, M. E.; Gai, W.; Konecny, R.; Power, J. G.; Gao, F.; Wong, T.; Yusof, Z.; High Energy Physics; Illinois Inst. of Tech.; Euclid Techlabs

    2009-01-01

    In this paper, we present updated results on power extraction testing of a 7.8 GHz dielectric loaded waveguide power extractor using both high charge single bunches and bunch trains. We have generated a 1.7 ns radio frequency (rf) pulse with 30 MW of power with a single 66 nC electron bunch. Then we have generated a pulse train of electron beam for rf generation of 10 ns and 22 ns rf pulses.

  12. 7.8 GHz High Power Generation And Extraction With A Dielectric-loaded Waveguide

    SciTech Connect

    Gao, F.; Conde, M. E.; Gai, W.; Konecny, R.; Liu, W.; Power, J. G.; Yusof, Z.; Jing, C.; Wong, T.

    2009-01-22

    In this paper, we present updated results on power extraction testing of a 7.8 GHz dielectric loaded waveguide power extractor using both high charge single bunches and bunch trains. We have generated a 1.7 ns radio frequency (rf) pulse with 30 MW of power with a single 66 nC electron bunch. Then we have generated a pulse train of electron beam for rf generation of 10 ns and 22 ns rf pulses.

  13. Radiotherapy combined with TLR7/8 activation induces strong immune responses against gastrointestinal tumors.

    PubMed

    Schölch, Sebastian; Rauber, Conrad; Tietz, Alexandra; Rahbari, Nuh N; Bork, Ulrich; Schmidt, Thomas; Kahlert, Christoph; Haberkorn, Uwe; Tomai, Mark A; Lipson, Kenneth E; Carretero, Rafael; Weitz, Jürgen; Koch, Moritz; Huber, Peter E

    2015-03-10

    In addition to local cytotoxic activity, radiotherapy may also elicit local and systemic antitumor immunity, which may be augmented by immunotherapeutic agents including Toll-like receptor (TLR) 7/8 agonists. Here, we investigated the ability of 3M-011 (854A), a TLR7/8 agonist, to boost the antigen-presenting activity of dendritic cells (DC) as an adjuvant to radiotherapy. The combined treatment induced marked local and systemic responses in subcutaneous and orthotopic mouse models of colorectal and pancreatic cancer. In vitro cytotoxicity assays as well as in vivo depletion experiments with monoclonal antibodies identified NK and CD8 T cells as the cell populations mediating the cytotoxic effects of the treatment, while in vivo depletion of CD11c+ dendritic cells (DC) in CD11c-DTR transgenic mice revealed DC as the pivotal immune hub in this setting. The specificity of the immune reaction was confirmed by ELISPOT assays. TLR7/8 agonists therefore seem to be potent adjuvants to radiotherapy, inducing strong local and profound systemic immune responses to tumor antigens released by conventional therapy.

  14. Radiotherapy combined with TLR7/8 activation induces strong immune responses against gastrointestinal tumors

    PubMed Central

    Tietz, Alexandra; Rahbari, Nuh N.; Bork, Ulrich; Schmidt, Thomas; Kahlert, Christoph; Haberkorn, Uwe; Tomai, Mark A.; Lipson, Kenneth E.; Carretero, Rafael; Weitz, Jürgen; Koch, Moritz; Huber, Peter E.

    2015-01-01

    In addition to local cytotoxic activity, radiotherapy may also elicit local and systemic antitumor immunity, which may be augmented by immunotherapeutic agents including Toll-like receptor (TLR) 7/8 agonists. Here, we investigated the ability of 3M-011 (854A), a TLR7/8 agonist, to boost the antigen-presenting activity of dendritic cells (DC) as an adjuvant to radiotherapy. The combined treatment induced marked local and systemic responses in subcutaneous and orthotopic mouse models of colorectal and pancreatic cancer. In vitro cytotoxicity assays as well as in vivo depletion experiments with monoclonal antibodies identified NK and CD8 T cells as the cell populations mediating the cytotoxic effects of the treatment, while in vivo depletion of CD11c+ dendritic cells (DC) in CD11c-DTR transgenic mice revealed DC as the pivotal immune hub in this setting. The specificity of the immune reaction was confirmed by ELISPOT assays. TLR7/8 agonists therefore seem to be potent adjuvants to radiotherapy, inducing strong local and profound systemic immune responses to tumor antigens released by conventional therapy. PMID:25609199

  15. Is 2,3,7,8-TCDD (dioxin) a carcinogen for humans

    SciTech Connect

    Ayres, S.M.; Webb, K.B.; Evans, R.G.; Mikes, J.

    1985-10-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has suddenly become the focal point of controversy over the relationship of chemical waste to human health. Specific concern exists regarding its potential association with human malignancy. Subcellular, cellular, and whole-animal experiments suggest that TCDD exerts much of its activity by inducing enzymes that protect the intact organism from the assault of environmental contamination. TCDD is a potent inducer of aryl hydrocarbon hydroxylase, although wide variations between species do exist. Conventional tests for mutagenicity have produced conflicting results. Animal experiments have shown the development of tumors following chronic low level ingestion of TCDD. The human evidence regarding the potential carcinogencity of TCDD comes from occupational, military and environmental exposures. Several studies have come out of Sweden suggesting an association between sarcoma and exposure to herbicides. Although there is little solid evidence that 2,3,7,8-TCDD produces substantial chronic disability or premature death in man, a significant body of experimental evidence for its carcinogenicity makes it likely that a small number of human malignancies may be due to its action. Since 2,3,7,8-TCDD is an unwanted contaminant it could be eliminated with little measurable consequence.

  16. Is 2,3,7,8-TCDD (dioxin) a carcinogen for humans?

    PubMed Central

    Ayres, S M; Webb, K B; Evans, R G; Mikes, J

    1985-01-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has suddenly become the focal point of controversy over the relationship of chemical waste to human health. Specific concern exists regarding its potential association with human malignancy. Subcellular, cellular, and whole-animal experiments suggest that TCDD exerts much of its activity by inducing enzymes that protect the intact organism from the assault of environmental contamination. TCDD is a potent inducer of aryl hydrocarbon hydroxylase, although wide variations between species do exist. Conventional tests for mutagenicity have produced conflicting results. Animal experiments have shown the development of tumors following chronic low level ingestion of TCDD. The human evidence regarding the potential carcinogencity of TCDD comes from occupational, military and environmental exposures. Several studies have come out of Sweden suggesting an association between sarcoma and exposure to herbicides. Although there is little solid evidence that 2,3,7,8-TCDD produces substantial chronic disability or premature death in man, a significant body of experimental evidence for its carcinogenicity makes it likely that a small number of human malignancies may be due to its action. Since 2,3,7,8-TCDD is an unwanted contaminant it could be eliminated with little measurable consequence. PMID:3910419

  17. Troubled Times for American Higher Education: The 1990s and Beyond. SUNY Series, Frontiers in Education.

    ERIC Educational Resources Information Center

    Kerr, Clark; And Others

    This volume looks at the future of American higher education in 13 essays most of which were originally speeches to gatherings around the United States and the globe. The first series of essays in Part I looks at possible "contours" of the future and what choices should be made by higher education to advance the quality of future performance. One…

  18. Ecuador's Higher Education System in Times of Change

    ERIC Educational Resources Information Center

    Van Hoof, Hubert B.; Estrella, Mateo; Eljuri, Marie-Isabel; León, Leonardo Torres

    2013-01-01

    Ecuador's higher education system is undergoing dramatic changes. The National Constitution of 2008 and the Higher Education Law of 2010 have changed the way Ecuador's universities are funded, administered, and accredited. The importance of research was elevated and drastic changes were made to the academic qualifications and employment…

  19. The Changing Faces of Corruption in Georgian Higher Education: Access through Times and Tests

    ERIC Educational Resources Information Center

    Orkodashvili, Mariam

    2012-01-01

    This article presents a comparative-historical analysis of access to higher education in Georgia. It describes the workings of corrupt channels during the Soviet and early post-Soviet periods and the role of standardized tests in fighting corruption in higher education admission processes after introduction of the Unified National Entrance…

  20. Carcinogenesis Bioassay of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (CAS No. 1746-01-6) in Swiss-Webster Mice (Dermal Study).

    PubMed

    1982-02-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin occurs as a highly toxic impurity found in herbicides containing 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and 2,4,5-T- derivatives, as well as in other chemicals synthesized using 2,4,5-trichlorophenol. The herbicide 2,4,5-T has been marketed in the United States since 1948. Production increased sharply between 1960 and 1970 when a 1:1 mixture of 2,4,5-T and 2,4-dichlorophenoxyacetic acid (2,4-D) was used as a defoliant in Vietnam under the names of "herbicide agent orange, herbicide orange, agent orange, and orange". During this 10-year period, about 106 million pounds of 2,4,5-T were sprayed. A carcinogenesis bioassay was conducted by applying an acetone suspension of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to the clipped backs of 30 male and female Swiss-Webster mice 3 days per week for 99 or 104 weeks. Similar groups were pretreated with 1 application of 50 &mgr;g dimethylbenzanthracene (DMBA) in 0.1 ml acetone 1 week before TCDD administration began. Female mice received 0.005 &mgr;g TCDD per application, and the male mice received 0.001 &mgr;g TCDD. As vehicle controls, 45 mice of each sex received 0.1 ml acetone three times per week. Thirty animals of each sex were used as untreated controls. Throughout the bioassay, mean body weights of the male and female mice administered TCDD, or TCDD following DMBA, were essentially the same as those of the corresponding vehicle control group. Mean body weights of dosed and vehicle control groups of males were less thanthose of the untreated control group throughout the study; for the females, mean body weights were less than the untreated controls during the first 80 weeks. In female mice, the incidences of fibrosarcoma in the integumentary system in dosed groups with TCDD were significantly (P=0.007) higher than that in the corresponding controls (2/41, 5%; 8/27, 30%). An increase in the same tumor type, although not statistically significant (P=0.084), was also observed in

  1. Carcinogenesis Bioassay of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (CAS No. 1746-01-6) in Swiss-Webster Mice (Dermal Study).

    PubMed

    1982-02-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin occurs as a highly toxic impurity found in herbicides containing 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and 2,4,5-T- derivatives, as well as in other chemicals synthesized using 2,4,5-trichlorophenol. The herbicide 2,4,5-T has been marketed in the United States since 1948. Production increased sharply between 1960 and 1970 when a 1:1 mixture of 2,4,5-T and 2,4-dichlorophenoxyacetic acid (2,4-D) was used as a defoliant in Vietnam under the names of "herbicide agent orange, herbicide orange, agent orange, and orange". During this 10-year period, about 106 million pounds of 2,4,5-T were sprayed. A carcinogenesis bioassay was conducted by applying an acetone suspension of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to the clipped backs of 30 male and female Swiss-Webster mice 3 days per week for 99 or 104 weeks. Similar groups were pretreated with 1 application of 50 &mgr;g dimethylbenzanthracene (DMBA) in 0.1 ml acetone 1 week before TCDD administration began. Female mice received 0.005 &mgr;g TCDD per application, and the male mice received 0.001 &mgr;g TCDD. As vehicle controls, 45 mice of each sex received 0.1 ml acetone three times per week. Thirty animals of each sex were used as untreated controls. Throughout the bioassay, mean body weights of the male and female mice administered TCDD, or TCDD following DMBA, were essentially the same as those of the corresponding vehicle control group. Mean body weights of dosed and vehicle control groups of males were less thanthose of the untreated control group throughout the study; for the females, mean body weights were less than the untreated controls during the first 80 weeks. In female mice, the incidences of fibrosarcoma in the integumentary system in dosed groups with TCDD were significantly (P=0.007) higher than that in the corresponding controls (2/41, 5%; 8/27, 30%). An increase in the same tumor type, although not statistically significant (P=0.084), was also observed in

  2. 2,3,4,7,8-pentachlorodibenzofuran is a more potent cytochrome P4501A inducer than 2,3,7,8-tetrachlorodibenzo-p-dioxin in herring gull hepatocyte cultures.

    PubMed

    Hervé, Jessica C; Crump, Doug L D; McLaren, Kristina K; Giesy, John P; Zwiernik, Matthew J; Bursian, Steven J; Kennedy, Sean W

    2010-09-01

    Concentration-dependent effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), and 2,3,7,8-tetrachlorodibenzofuran (TCDF) on cytochrome P4501A (CYP1A) induction were determined in primary cultures of embryonic herring gull (Larus argentatus) hepatocytes exposed for 24 h. Based on the concentration that induced 50% of the maximal response (EC50), the relative potencies of TCDD and TCDF did not differ by more than 3.5-fold. However, also based on the EC50, PeCDF was 40-fold, 21-fold, and 9.8-fold more potent for inducing ethoxyresorufin-O-deethylase (EROD) activity, CYP1A4 mRNA expression, and CYP1A5 mRNA expression than TCDD, respectively. The relative CYP1A-inducing potencies of PeCDF and of other dioxin-like chemicals (DLCs) in herring gull hepatocytes (HEH RePs), along with data on concentrations of DLCs in Great Lakes herring gull eggs, were used to calculate World Health Organization toxic equivalent (WHO-TEQ) concentrations and herring gull embryonic hepatocyte toxic equivalent (HEH-TEQ) concentrations. The analysis indicated that, when using avian toxic equivalency factors (TEFs) recommended by the WHO, the relative contribution of TCDD (1.1-10.2%) to total WHO-TEQ concentration was higher than that of PeCDF (1.7-2.9%). These results differ from the relative contribution of TCDD and PeCDF when HEH RePs were used; PeCDF was a major contributor (36.5-52.9%) to total HEH-TEQ concentrations, whereas the contribution by TCDD (1.2-10.3%) was less than that of PeCDF. The WHO TEFs for avian species were largely derived from studies with the domestic chicken (Gallus gallus domesticus). The findings of the present study suggest that it is necessary to determine the relative potencies of DLCs in wild birds and to re-evaluate their relative contributions to the biochemical and toxic effects previously reported in herring gulls and other avian species.

  3. Part-Time Students and Part-Time Study in Higher Education in the UK: Strand 1--A Quantitative Data Analysis of 2003/04 HESA Data

    ERIC Educational Resources Information Center

    Ramsden, Brian

    2006-01-01

    This is a report of the Strand 1 element of the Universities UK project to examine part-time students and part-time study within the United Kingdom. The aim of Strand 1 of this project is to set out, as far as possible, factual information about students studying part-time and following programmes of study leading to higher education…

  4. Use of Part-Time Faculty in Higher Education: Numbers and Impact. Briefing Papers.

    ERIC Educational Resources Information Center

    Miller, Ross

    Colleges and universities of all kinds rely on part-time faculty to teach students from the freshman year through graduate studies, although they are more likely to teach lower division students. Overall, 43% of postsecondary instructional faculty work part-time, while full-time tenure track positions are held by about 18% of faculty members.…

  5. The Impact of Part-Time Faculty on Student Retention: A Case Study in Higher Education

    ERIC Educational Resources Information Center

    Smith, Curtis V.

    2010-01-01

    There has been considerable debate in community colleges over the last forty years regarding the impact of increased use of part-time faculty (PTF) on student learning. It has been argued that part-time faculty fail to provide the same level of teaching quality as full-time faculty (FTF). The purpose of this study was to determine the impact of…

  6. Identification of stable benzo[a]pyrene-7,8-dione-DNA adducts in human lung cells.

    PubMed

    Huang, Meng; Blair, Ian A; Penning, Trevor M

    2013-05-20

    Metabolic activation of the proximate carcinogen benzo[a]pyrene-7,8-trans-dihydrodiol (B[a]P-7,8-trans-dihydrodiol) by aldo-keto reductases (AKRs) leads to B[a]P-7,8-dione that is both electrophilic and redox-active. B[a]P-7,8-dione generates reactive oxygen species resulting in oxidative DNA damage in human lung cells. However, information on the formation of stable B[a]P-7,8-dione-DNA adducts in these cells is lacking. We studied stable DNA adduct formation of B[a]P-7,8-dione in human lung adenocarcinoma A549 cells, human bronchoalveolar H358 cells, and immortalized human bronchial epithelial HBEC-KT cells. After treatment with 2 μM B[a]P-7,8-dione, the cellular DNA was extracted from the cell pellets subjected to enzyme hydrolysis and subsequent analysis by LC-MS/MS. Several stable DNA adducts of B[a]P-7,8-dione were only detected in A549 and HBEC-KT cells. In A549 cells, the structures of stable B[a]P-7,8-dione-DNA adducts were identified as hydrated-B[a]P-7,8-dione-N(2)-2'-deoxyguanosine and hydrated-B[a]P-7,8-dione-N1-2'-deoxyguanosine. In HBEC-KT cells, the structures of stable B[a]P-7,8-dione-DNA adducts were identified as hydrated-B[a]P-7,8-dione-2'-deoxyadenosine, hydrated-B[a]P-7,8-dione-N1- or N3-2'-deoxyadenosine, and B[a]P-7,8-dione-N1- or N3-2'-deoxyadenosine. In each case, adduct structures were characterized by MS(n) spectra. Adduct structures were also compared to those synthesized from reactions of B[a]P-7,8-dione with either deoxyribonucleosides or salmon testis DNA in vitro but were found to be different.

  7. Genotoxicity tests with 6-acetyl-1,1,2,4,4,7-hexamethyltetraline and 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-gamma-2-benzopyr an.

    PubMed

    Api, A M; San, R H

    1999-10-29

    6-Acetyl-1,1,2,4,4,7-hexamethyltetraline (AHTN) and 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-gamma-2-ben zopyran (HHCB), synthetic fragrance ingredients, were evaluated for potential genotoxicity in a battery of short-term tests. Salmonella typhimurium/Escherichia coli plate incorporation and liquid preincubation assays were conducted on AHTN using tester strains TA97, TA98, TA100, TA102, TA1535, TA1537 and WP2 uvrA +/- S9 activation at doses from 8 to 5000 micrograms/plate. The plate incorporation mutagenicity assay was conducted on HHCB using tester strains TA98, TA100, TA1535, TA1537, TA1538 and WP2 uvrA +/- S9 activation at doses from 10 to 5000 micrograms/plate. An in vitro cytogenetics assay in Chinese hamster ovary (CHO) cells was conducted with AHTN and HHCB at three concentrations each with +/- S9 activation. In the non-activated study, the exposure/harvest periods were 4/20-, 20/20- and 44/44-h. In the S9 activated study, the exposure/harvest periods were 4/20- and 4/44-h. In vitro unscheduled DNA synthesis (UDS) assays were conducted in primary rat hepatocytes at concentrations between 0.15 and 50 micrograms/ml for AHTN and HHCB. In vivo mouse micronucleus assays were conducted with high doses of 1600 mg AHTN/kg and of 1500 mg HHCB/kg in corn oil. No positive responses were observed in any of the tests with HHCB. With AHTN, no positive responses were observed except for cells with structural aberrations in the in vitro cytogenetics assay in CHO cells with S9 activation at the treatment/harvest time of 4/20 h. In initial studies with AHTN, the high dose of 7.8 micrograms/ml showed 0.5% aberrant cells, with the mitotic index at 41% relative to vehicle control and cell growth inhibition in the range of 25-50%. Thus the genotoxicity findings with AHTN were limited to this one positive response; all other genotoxicity tests with AHTN were considered as negative. In particular, the negative finding in the in vivo assay supports AHTN as not likely

  8. Classical and quantum-mechanical axioms with the higher time derivative formalism

    NASA Astrophysics Data System (ADS)

    Kamalov, Timur

    2013-06-01

    A Newtonian mechanics model is essentially the model of a point body in an inertial reference frame. How to describe extended bodies in non-inertial (vibration) reference frames with the random initial conditions? One of the most generalized ways of descriptions (known as the higher derivatives formalism) consists in taking into account the infinite number of the higher temporal derivatives of the coordinates in the Lagrange function. Such formalism describing physical objects in the infinite dimensions space does not contradict to the quantum mechanics and infinite dimensions Hilbert space.

  9. Effect of 7,8-dihydroxyflavone as an antioxidant on in vitro maturation of oocytes and development of parthenogenetic embryos in pigs.

    PubMed

    Choi, Ji-Yei; Kang, Jung-Taek; Park, Sol-Ji; Kim, Su-Jin; Moon, Joon-Ho; Saadeldin, Islam M; Jang, Goo; Lee, Byeong-Chun

    2013-10-01

    One of the factors that impairs in vitro produced porcine embryos is the oxidative stress that is mainly caused by the imbalance between reactive oxygen species (ROS) generation and antioxidants activity, especially that of glutathione (GSH). Here, we examined the effect of 7,8-dihydroxyflavone (7,8-DHF), a kind of flavonoid antioxidant, on porcine oocyte maturation and its developmental competence. Porcine oocytes were cultured in media supplemented with 0, 1, 5 and 10 μM 7,8-DHF during both in vitro maturation (IVM) and in vitro culture (IVC) after parthenogenetic activation. Maturation of oocytes was evaluated based on first polar body (PB) extrusion and intracellular GSH level, and developmental competence was assessed through observing cleavage and blastocyst formation. In each step, the levels of intracellular GSH and ROS were assessed by fluorescence intensity, and the apoptosis-related gene expression was examined using semiquantitative RT-PCR. The group treated with 1 μM 7,8-DHF during IVM and IVC showed increased cytoplasmic maturation and reached the blastocysts stage (36.1%) at a higher rate than the other groups (24.7, 16.0 and 10.3% for 0, 5 and 10 μM, P<0.05). In that group, the intracellular GSH level was significantly increased while ROS generation was significantly decreased after IVM and IVC (P<0.05). Moreover, it showed high expression of an anti-apoptotic gene (BCL2L1) and low expression of a pro-apoptotic gene (BAK1) (P<0.05). In conclusion, treatment with 1 μM 7,8-DHF during IVM and IVC showed an anti-apoptotic effect by increasing intracellular GSH synthesis and scavenging ROS and therefore improved the developmental competence of porcine embryos. PMID:23748647

  10. Thermal iron ions in high speed solar wind streams Detection by the IMP 7/8 energetic particle experiments

    NASA Technical Reports Server (NTRS)

    Mitchell, D. G.; Roelof, E. C.

    1980-01-01

    The first measurements of the abundance of iron ions in high speed (greater than 600 km/s) solar wind streams have been made with the NOAA/JHU energetic particles experiments (EPE) on IMP 7/8. The identification of iron ions is quantitatively established using 4 years of observations and heavy ion accelerator calibrations of detectors similar to those flown on the spacecraft. Preliminary estimates of the Fe/H ratio are within a factor of 2 of the adopted coronal abundance (0.00005), and there is some evidence that Fe/H may remain approximately constant within a given stream. In the peaks of fast streams (700-800 km/s), about 50 iron ion counts are obtained every 20 s, offering the possibility of studying the Fe/H ratio with approximately 1 m time resolution in high speed streams throughout the decline of Solar Cycle 20 and the rise of Solar Cycle 21.

  11. Spectral imaging of the Orion Bar at 6.2 and 7.8 microns

    NASA Technical Reports Server (NTRS)

    Bregman, Jesse; Harker, David; Rank, David; Temi, Pasquale

    1995-01-01

    We have obtained images of the Orion Bar region through narrow-band filters at 6.2 and 7.8 mu m to determine whether the emission observed at these wavelengths arises from C-C modes in polycyclic aromatic hydrocarbons (PAH's). Morphologically, the distribution of the emissions are similar, but appear different in detail. Quantitative comparisons of these band intensities with previous data at 8.4 and 11.3 mu m indicates that they are indeed consistent with emission from fluorescently excited PAH molecules.

  12. Geotechnical effects of the 2015 magnitude 7.8 Gorkha, Nepal, earthquake and aftershocks

    USGS Publications Warehouse

    Moss, Robb E S; Thompson, Eric; Kieffer, D Scott; Tiwari, Binod; Hashash, Youssef M A; Acharya, Indra; Adhikari, Basanta; Asimaki, Domniki; Clahan, Kevin B.; Collins, Brian D.; Dahal, Sachindra; Jibson, Randall W.; Khadka, Diwakar; Macdonald, Amy; Madugo, Chris L M; Mason, H Benjamin; Pehlivan, Menzer; Rayamajhi, Deepak; Uprety, Sital

    2015-01-01

    This article summarizes the geotechnical effects of the 25 April 2015 M 7.8 Gorkha, Nepal, earthquake and aftershocks, as documented by a reconnaissance team that undertook a broad engineering and scientific assessment of the damage and collected perishable data for future analysis. Brief descriptions are provided of ground shaking, surface fault rupture, landsliding, soil failure, and infrastructure performance. The goal of this reconnaissance effort, led by Geotechnical Extreme Events Reconnaissance, is to learn from earthquakes and mitigate hazards in future earthquakes.

  13. A robust synthesis of 7,8-didemethyl-8-hydroxy-5-deazariboflavin.

    PubMed

    Bender, Matthias; Mouritsen, Henrik; Christoffers, Jens

    2016-01-01

    The biosynthetic precursor of redox cofactor F420, 7,8-didemethyl-8-hydroxy-5-deazariboflavin, was prepared in four steps from 6-chlorouracil, 2-chloro-4-hydroxybenzaldehyde and bis-isopropylidene protected D-ribose. The latter aldehyde was transformed to the corresponding protected ribitylamine via the oxime, which was submitted to reduction with LiAlH4. Key advantage compared to previous syntheses is the utilization of a polyol-protective group which allowed the chromatographic purification of a key-intermediate product providing the target compound with high purity. PMID:27340481

  14. The UT 7/8 February 2013 Sila-Nunam Mutual Event and Future Predictions

    NASA Technical Reports Server (NTRS)

    Benecchi, S. D.; Noll, K. S.; Thirouin, A.; Ryan, E.; Grundy, W. M.; Verbiscer, A.; Doressoundiram, A.; Hestroffer, D.; Beaton, R.; Rabinowitz, D.; Chanover, N.

    2013-01-01

    A superior mutual event of the Kuiper Belt binary system (79360) Sila-Nunam was observed over 15.47 h on UT 7/8 February 2013 by a coordinated effort at four different telescope facilities; it started approximately 1.5 h earlier than anticipated, the duration was approximately 9.5 h (about 10% longer than predicted), and was slightly less deep than predicted. It is the first full event observed for a comparably sized binary Kuiper Belt object. We provide predictions for future events refined by this and other partial mutual event observations obtained since the mutual event season began.

  15. A robust synthesis of 7,8-didemethyl-8-hydroxy-5-deazariboflavin

    PubMed Central

    Bender, Matthias; Mouritsen, Henrik

    2016-01-01

    Summary The biosynthetic precursor of redox cofactor F420, 7,8-didemethyl-8-hydroxy-5-deazariboflavin, was prepared in four steps from 6-chlorouracil, 2-chloro-4-hydroxybenzaldehyde and bis-isopropylidene protected D-ribose. The latter aldehyde was transformed to the corresponding protected ribitylamine via the oxime, which was submitted to reduction with LiAlH4. Key advantage compared to previous syntheses is the utilization of a polyol-protective group which allowed the chromatographic purification of a key-intermediate product providing the target compound with high purity. PMID:27340481

  16. A toxicological study of 5,6,7,8 tetrafluoro- 1,4-benzodioxin

    SciTech Connect

    London, J.E.

    1988-05-01

    The acute oral LD/sub 50/ values for 5,6,7,8 tetrafluro-1,4 benzodioxin for mice and rats are less than 5 gkg. According to classical guidelines, the material is considered slightly toxic in both species. The sensitization study in the guinea pig did not show the material to have potential sensitizing properties. Skin application studies on the rabbit demonstrated that it was cutaneously mildly irritating. This material was very mildly irritating in the rabbit eye application studies. 4 refs., 2 tabs.

  17. Hexachlorodibenzo-p-dioxin (HxCDD), mixture of 1,2,3,6,7,8-HxCDD and 1,2,3,7,8,9-HxCDD

    Integrated Risk Information System (IRIS)

    Hexachlorodibenzo - p - dioxin ( HxCDD ) , mixture of 1,2,3,6,7,8 - HxCDD and 1,2,3,7,8,9 - HxCDD ; CASRN 57653 - 85 - 7 and 19408 - 74 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in

  18. The Challenge and Promise of Catholic Higher Education for Our Time

    ERIC Educational Resources Information Center

    Jenkins, John I.

    2015-01-01

    Catholic colleges and universities face significant challenges in the present context of American higher education. Yet, there are opportunities to be found in the midst of this crisis when one carefully examines the intersections between the Catholic mission and objectives of an institution and current culture and academia. A return to the…

  19. Catching the Window of Opportunity: Being on Time for Higher Education.

    ERIC Educational Resources Information Center

    Kempner, Ken; Kinnick, Mary

    1990-01-01

    A longitudinal study of 2100 high school students indicates a "window of opportunity" opens for individuals entering higher education immediately after high school. Students delaying college entry are less likely to attain a bachelor's degree. The finding is critical for students without characteristics to mediate the disadvantage of stopping out.…

  20. Challenges to Christian Higher Education at a Time of Increasing Emphasis on Research

    ERIC Educational Resources Information Center

    Hemmings, Brian; Hill, Doug

    2014-01-01

    In Australia, both Christian and non-Christian higher education institutions (HEIs) have experienced a rapidly changing external environment that is becoming more performance-driven, particularly in relation to faculty research. Academics working in Australian Christian HEIs often feel pressure to keep pace with their counterparts in non-Christian…

  1. Rural Education: A Field of Study Whose Time Has Come in Higher Education.

    ERIC Educational Resources Information Center

    Warner, Richard W., Jr.; Kale, Karen E.

    Although professional educators and public school decision makers have attempted to respond to increased educational demands and a broader spectrum of students, the education of rural youth is a neglected area both in higher education and in educational legislation. The record indicates that policy decisions and the resulting legislation have…

  2. Retention and Attrition of Students in Higher Education: Challenges in Modern Times to What Works

    ERIC Educational Resources Information Center

    Maher, Marguerite; Macallister, Helen

    2013-01-01

    Retention and attrition rates in higher education have long been a focus of research. This paper presents findings of a single case study, undertaken in a School of Education, which identify important strategies that have led to attrition of five to eight per cent, compared with 18 per cent cross the education sector in Australia (Department of…

  3. The Effective Academic: A Handbook for Enhanced Academic Practice. The Times Higher Education Supplement.

    ERIC Educational Resources Information Center

    Ketteridge, Steve, Ed.; Marshall, Stephanie, Ed.; Fry, Heather, Ed.

    This handbook provides guidance about controlling and directing an academic career by suggesting systematic approaches to key areas of responsibility and activity. It explores management and leadership in higher education, developing and promoting research and teaching, and coping with the changing university environment. The chapters of part 1,…

  4. Examining a Higher Education Funding Formula in a Time of Shifting Currents: Kentucky's Benchmark Approach

    ERIC Educational Resources Information Center

    Wall, Andrew; Frost, Robert; Smith, Ryan; Keeling, Richard

    2008-01-01

    Although datasets such as the Integrated Postsecondary Data System are available as inputs to higher education funding formulas, these datasets can be unreliable, incomplete, or unresponsive to criteria identified by state education officials. State formulas do not always match the state's economic and human capital goals. This article analyzes…

  5. Integrating Health and Sustainability: The Higher Education Sector as a Timely Catalyst

    ERIC Educational Resources Information Center

    Orme, J.; Dooris, M.

    2010-01-01

    Higher education is an influential sector with enormous potential to impact positively on health and sustainability. The purpose of this paper was to explore its emergent role as a key setting for promoting health and sustainability and for addressing their challenges in an integrated and coherent way. Acknowledging both the relative narrowness of…

  6. Breadth vs. Depth: The Timing of Specialization in Higher Education. NBER Working Paper No. 15943

    ERIC Educational Resources Information Center

    Malamud, Ofer

    2010-01-01

    This paper examines the tradeoff between early and late specialization in the context of higher education. While some educational systems require students to specialize early by choosing a major field of study prior to entering university, others allow students to postpone this choice. I develop a model in which individuals, by taking courses in…

  7. Mechanism for repair of thymine dimers by photoexcitation of proximal 8-oxo-7,8-dihydroguanine.

    PubMed

    Anusiewicz, Iwona; Świerszcz, Iwona; Skurski, Piotr; Simons, Jack

    2013-02-14

    A wide range of experimental data from earlier studies by other workers are combined with recent data from the Burrows group to interpret that group's thymine dimer (T = T) repair rate data for 8-oxo-7,8-dihydroguanine (OG)-containing DNA duplexes. The focus of this effort is to explain (i) how and why the repair rates vary as the sequence location and distance of the OG relative to the T═T is changed and (ii) why the spatial extent over which repair is observed is limited to OG-T═T distances of ~6 Å. It is proposed that, if the OG and T═T are within ~5-6 Å, a Coulomb potential moves the energy of the OG(+)···T═T(-) ion-pair state below the photoexcited OG*···T═T state, even in the absence of full solvent relaxation, thus enhancing forward electron transfer from OG* to T═T by allowing it to occur as a radiationless internal conversion process rather than by overcoming a solvation-related barrier. The rate of this forward electron transfer is estimated to be ~10% of the decay rate of the photoexcited OG*. For OG-to-T═T distances beyond 5-6 Å, electron transfer is still exothermic, but it must occur through solvent reorganization, overcoming an energy barrier, which presumably renders this rate too slow to be detected in the experiments under study here. Once an electron has been injected into the T═T, as many other workers have shown, the reaction proceeds through two low-energy barriers first connecting T═T(-) to an intermediate in which the C(5)-C(5') bond of the cyclobutane unit is cleaved, and onward to where the cyclobutane unit is fully broken and two intact thymine sites are established. Our ab initio data show that the energy landscape for these bond cleavages is altered very little by the presence of the proximal OG(+) cation, which therefore allows us to use data from the earlier studies to conclude that it takes ~100 ps for complete bond cleavage to occur. The experimentally determined overall T═T repair quantum yield of 1

  8. First integrals for time-dependent higher-order Riccati equations by nonholonomic transformation

    NASA Astrophysics Data System (ADS)

    Guha, Partha; Ghose Choudhury, A.; Khanra, Barun

    2011-08-01

    We exploit the notion of nonholonomic transformations to deduce a time-dependent first integral for a (generalized) second-order nonautonomous Riccati differential equation. It is further shown that the method can also be used to compute the first integrals of a particular class of third-order time-dependent ordinary differential equations and is therefore quite robust.

  9. The Impact of Term-Time Employment on Higher Education Students' Academic Attainment and Achievement

    ERIC Educational Resources Information Center

    Callender, Claire

    2008-01-01

    Term-time employment among Britain's undergraduates is a growing phenomenon but it has received scant attention from government and policy makers. Although there are numerous studies on the subject, few have explored the impact of term-time employment on students' actual attainment and those that have are limited. This article attempts to fill…

  10. Do Diligent Students Perform Better? Complex Relations between Student and Course Characteristics, Study Time, and Academic Performance in Higher Education

    ERIC Educational Resources Information Center

    Masui, Chris; Broeckmans, Jan; Doumen, Sarah; Groenen, Anne; Molenberghs, Geert

    2014-01-01

    Research has reported equivocal results regarding the relationship between study time investment and academic performance in higher education. In the setting of the active, assignment-based teaching approach at Hasselt University (Belgium), the present study aimed (a) to further clarify the role of study time in academic performance, while taking…

  11. Exposure and effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin in tree swallows (Tachycineta bicolor) nesting along the Woonasquatucket River, Rhode Island, USA

    USGS Publications Warehouse

    Custer, Christine M.; Custer, T.W.; Rosiu, C.J.; Melancon, M.J.; Bickham, J.W.; Matson, C.W.

    2005-01-01

    Concentrations of 2,3,7,8 -tetrachlorodibenzo-p-dioxin (TCDD) in tree swallows (Tachycineta hicolor) nesting along the Woonasquatucket River northwest of Providence (RI, USA) in 2000 and 2001 were some of the highest ever reported in avian tissues. Mean concentrations in eggs ranged from 300 to > 1,000 pg/g wet weight at the two most contaminated ponds, Allendale and Lyman. Mean egg concentrations at Greystone, the upstream reference pond, were 12 and 29 pg/g. Positive accumulation rates and concentrations in diet samples from 12-day-old nestlings indicated that the contamination was accumulated locally. Concentrations in diet of between 71 and 219 pg/g wet weight were more than 6 and 18 times higher than concentrations considered safe for birds (10- 12 pg/g). Hatching success was negatively associated with concentration of TCDD in eggs. Only about half the eggs hatched at Allendale compared with >77% at Greystone. The national average for hatching success in successful nests is 85%. No other contaminants, such as polychlorinated biphenyls and mercury, were present in any sample at concentrations known to affect avian reproduction. Three bioindicators, half-peak coefficient of geometric variation, ethoxyresorufin-O-dealkylase activity, and brain asymmetry were assessed relative to TCDD contamination.

  12. Exposure and effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin in tree swallows (Tachycineta bicolor) nesting along the Woonasquatucket River, Rhode Island, USA

    USGS Publications Warehouse

    Custer, Christine M.; Custer, T.W.; Rosiu, C.J.; Melancon, M.J.; Bickham, J.W.; Matson, C.W.

    2005-01-01

    Concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in tree swallows (Tachycineta bicolor) nesting along the Woonasquatucket River northwest of Providence (RI, USA) in 2000 and 2001 were some of the highest ever reported in avian tissues. Mean concentrations in eggs ranged from 300 to >1,000 pg/g wet weight at the two most contaminated ponds, Allendale and Lyman. Mean egg concentrations at Greystone, the upstream reference pond, were 12 and 29 pg/g. Positive accumulation rates and concentrations in diet samples from 12-day-old nestlings indicated that the contamination was accumulated locally. Concentrations in diet of between 71 and 219 pg/g wet weight were more than 6 and 18 times higher than concentrations considered safe for birds (10?12 pg/g). Hatching success was negatively associated with concentration of TCDD in eggs. Only about half the eggs hatched at Allendale compared with >77% at Greystone. The national average for hatching success in successful nests is 85%. No other contaminants, such as polychlorinated biphenyls and mercury, were present in any sample at concentrations known to affect avian reproduction. Three bioindicators, half-peak coefficient of geometric variation, ethoxyresorufin-O-dealkylase activity, and brain asymmetry were assessed relative to TCDD contamination.

  13. Integrating health and sustainability: the higher education sector as a timely catalyst.

    PubMed

    Orme, J; Dooris, M

    2010-06-01

    Higher education is an influential sector with enormous potential to impact positively on health and sustainability. The purpose of this paper was to explore its emergent role as a key setting for promoting health and sustainability and for addressing their challenges in an integrated and coherent way. Acknowledging both the relative narrowness of the environmental focus that has to date characterized and driven universities' work in relation to sustainability and the demonstrable value of adopting a whole-system approach, this paper will explore the concept of 'Healthy Universities' as a means of furthering debate and facilitating synergy between public health, sustainable development and climate change. Higher education represents one large-scale sector with a unique combination of roles that can be harnessed to focus and mobilize its education, knowledge exchange, research, corporate responsibility and future shaping agendas to achieve significant impacts in this area. It is the growing commitment to embedding health and well-being within the mainstream business of higher education coupled with the expectation that universities will act sustainably in all that they do that provides the perfect springboard to influence a process of 'co-ordinated action' to address climate change and impact positively on the integrated health and sustainability agenda. PMID:20382673

  14. Integrating health and sustainability: the higher education sector as a timely catalyst.

    PubMed

    Orme, J; Dooris, M

    2010-06-01

    Higher education is an influential sector with enormous potential to impact positively on health and sustainability. The purpose of this paper was to explore its emergent role as a key setting for promoting health and sustainability and for addressing their challenges in an integrated and coherent way. Acknowledging both the relative narrowness of the environmental focus that has to date characterized and driven universities' work in relation to sustainability and the demonstrable value of adopting a whole-system approach, this paper will explore the concept of 'Healthy Universities' as a means of furthering debate and facilitating synergy between public health, sustainable development and climate change. Higher education represents one large-scale sector with a unique combination of roles that can be harnessed to focus and mobilize its education, knowledge exchange, research, corporate responsibility and future shaping agendas to achieve significant impacts in this area. It is the growing commitment to embedding health and well-being within the mainstream business of higher education coupled with the expectation that universities will act sustainably in all that they do that provides the perfect springboard to influence a process of 'co-ordinated action' to address climate change and impact positively on the integrated health and sustainability agenda.

  15. Effective innate and adaptive antimelanoma immunity through localized TLR7/8 activation.

    PubMed

    Singh, Manisha; Khong, Hiep; Dai, Zhimin; Huang, Xue-Fei; Wargo, Jennifer A; Cooper, Zachary A; Vasilakos, John P; Hwu, Patrick; Overwijk, Willem W

    2014-11-01

    Intratumoral immune activation can induce local and systemic antitumor immunity. Imiquimod is a cream-formulated, TLR7 agonist that is Food and Drug Administration approved for the treatment of nonmelanoma skin cancers, but it has limited activity against melanoma. We studied the antitumor activity and mechanism of action of a novel, injectable, tissue-retained TLR7/8 agonist, 3M-052, which avoids systemic distribution. Intratumoral administration of 3M-052 generated systemic antitumor immunity and suppressed both injected and distant, uninjected wild-type B16.F10 melanomas. Treated tumors showed that an increased level of CCL2 chemokines and infiltration of M1 phenotype-shifted macrophages, which could kill tumor cells directly through production of NO and CCL2, were essential for the antitumor activity of 3M-052. CD8(+) T cells, B cells, type I IFN, IFN-γ, and plasmacytoid dendritic cells were contributed to efficient tumor suppression, whereas perforin, NK cells, and CD4 T cells were not required. Finally, 3M-052 therapy potentiated checkpoint blockade therapy with anti-CTLA-4 and anti-programmed death ligand 1 Abs, even when checkpoint blockade alone was ineffective. Our findings suggest that intratumoral treatment with 3M-052 is a promising approach for the treatment of cancer and establish a rational strategy and mechanistic understanding for combination therapy with intratumoral, tissue-retained TLR7/8 agonist and checkpoint blockade in metastatic cancer. PMID:25252955

  16. Effective innate and adaptive anti-melanoma immunity through localized TLR-7/8 activation

    PubMed Central

    Singh, Manisha; Khong, Hiep; Dai, Zhimin; Huang, Xue-Fei; Wargo, Jennifer A.; Cooper, Zachary A.; Vasilakos, John P.; Hwu, Patrick; Overwijk, Willem W.

    2014-01-01

    Intratumoral immune activation can induce local and systemic anti-tumor immunity. Imiquimod is a cream-formulated, TLR-7 agonist that is FDA-approved for the treatment of non-melanoma skin cancers, but has limited activity against melanoma. We studied the anti-tumor activity and mechanism of action of a novel, injectable, tissue-retained TLR 7/8 agonist, 3M-052, which avoids systemic distribution. Intratumoral administration of 3M-052 generated systemic anti-tumor immunity, and suppressed both injected and distant, uninjected wild-type B16.F10 melanomas. Treated tumors showed increased level of CCL2 chemokines and infiltration of M1 phenotype-shifted macrophages, which could kill tumor cells directly through production of nitric oxide and CCL2, was essential for the anti-tumor activity of 3M-052. CD8+ T cells, B cells, Type I IFN, IFN-γ, and pDC were contributed to efficient tumor suppression whereas perforin, NK cells and CD4 T cells were not required. Finally, 3M-052 therapy potentiated checkpoint blockade therapy with anti-CTLA-4 and anti-PD-L1 antibodies, even when checkpoint blockade alone was ineffective. Our findings suggest that intratumoral treatment with 3M-052 is a promising approach for the treatment of cancer and establish a rational strategy and mechanistic understanding for combination therapy with intratumoral, tissue-retained TLR7/8 agonist and checkpoint blockade in metastatic cancer. PMID:25252955

  17. [The functional state of the cardiovascular system and the level of physical performance in 7-8-year-old children under conditions of aerotechnogenic pollution].

    PubMed

    Tuliakova, O V

    2012-01-01

    The aim of the study was to investigate the functional state of the cardiovascular system and the level of physical performance in 7-8-year-old children living in the urban area where air pollution caused by heavy vehicle traffic is high. The cardiovascular system and physical performance were evaluated using the conventional methods in 7-8-year-old 1097 children: a control group included 652 children (363 boys and 289 girls) and a comparison group consisted of 445 persons (239 boys and 206 girls). Under aerotechnogenic pollution, diastolic and mean blood pressures were found to be higher in both groups; the maximum oxygen consumption was lower in the boys and the girls had a decreased heart rate following 4-minute exercise.

  18. Spanish Zimbardo Time Perspective Inventory Construction and Validity among Higher Education Students

    ERIC Educational Resources Information Center

    Usart, Mireia; Romero, Margarida

    2014-01-01

    Introduction: The study of "Time Orientation" (TO) has been focused on how to measure this construct and its effects on human behavior. Defined as a fundamental psychological variable, TO is multidimensional, sensible to cultural differences and age. Although its relation to learning, it deserves further study in the different Higher…

  19. Higher Dimensional Clayton–Oakes Models for Multivariate Failure Time Data

    PubMed Central

    Prentice, R. L.

    2016-01-01

    Summary The Clayton–Oakes bivariate failure time model is extended to dimensions m > 2 in a manner that allows unspecified marginal survivor functions for all dimensions less than m. Special cases that allow unspecified marginal survivor functions of dimension q with q < m, while making some provisions for dependencies of dimension greater than q, are also described. PMID:27738350

  20. Widening Participation, Social Justice and Injustice: Part-Time Students in Higher Education in England

    ERIC Educational Resources Information Center

    Callender, Claire

    2011-01-01

    This article critically assesses the nature and scope of current financial support for part-time undergraduates in England, highlighting its importance for widening participation. It considers the limitations of these financial arrangements, why they are in need of reform, and some of the consequences of their inadequacies. The paper argues that…

  1. Preparation and Support of Part-Time Teachers in Higher Education.

    ERIC Educational Resources Information Center

    Nicol, David J.

    2000-01-01

    Examines research on preparation and support of part-time faculty, analyzing four areas of support: institutional policies and practices, formal preparation programs, monitoring and evaluation systems, and formal and informal support measures in academic departments. Key processes and problems in each area are discussed, examining issues that must…

  2. Transformation or Decline? Using Tough Times to Create Higher-Performing Schools

    ERIC Educational Resources Information Center

    Miles, Karen Hawley

    2011-01-01

    Instead of doing less with less during these fiscally challenging times, school districts can seize the moment to usher in school transformation that will leave the schools, families, and communities better off. They could follow the lead of districts such as Baltimore City, Syracuse, and Charlotte-Mecklenburg to think outside traditional cost…

  3. Lyapunov-type inequality for a higher order dynamic equation on time scales.

    PubMed

    Sun, Taixiang; Xi, Hongjian

    2016-01-01

    The purpose of this work is to establish a Lyapunov-type inequality for the following dynamic equation [Formula: see text]on some time scale T under the anti-periodic boundary conditions [Formula: see text], where [Formula: see text] for [Formula: see text] and [Formula: see text], [Formula: see text] with [Formula: see text] and [Formula: see text], p is the quotient of two odd positive integers and [Formula: see text] with [Formula: see text]. PMID:27652044

  4. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and long term immunologic memory.

    PubMed

    Sherr, David H

    2004-06-01

    The highlighted article by B. Paige Lawrence and Beth Vorderstrasse addresses an oft forgotten aspect of immunotoxicity, the effects of environmental toxins on immunologic memory. Here, the authors take a step towards filling that information gap by evaluating the effects of a prototypic environmental toxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), on memory responses to a real-world pathogen, influenza A virus, presented to an animal model in a physiologically relevant manner. Multiple outcomes are evaluated, the vast majority of which suggest important and long-term TCDD-induced changes in the immune system after both primary and secondary exposure to this pathogen. The implications of these studies with regard to the immuno-competence of TCDD-exposed individuals are far reaching.

  5. One-Dimensional σ-MODELS with N = 5, 6, 7, 8 Off-Shell Supersymmetries

    NASA Astrophysics Data System (ADS)

    Gonzales, M.; Rojas, M.; Toppan, F.

    We computed the actions for the one-dimensional (1D) N = 5 σ-models with respect to the two inequivalent (2, 8, 6) multiplets. Four supersymmetry generators are manifest, while the constraint originated by imposing the fifth supersymmetry automatically induces a full N = 8 off-shell invariance. The resulting action coincides in the two cases and corresponds to a conformally flat 2D target satisfying a special geometry of rigid type. To obtain these results we developed a computational method (for Maple 11) which does not require the notion of superfields and is instead based on the nowadays available list of the inequivalent representations of the 1D N-extended supersymmetry. Its application to systematically analyze the σ-models off-shell invariant actions for the remaining N = 5, 6, 7, 8 (k, 8, 8-k) multiplets, as well as for the N>8 representations, only requires more cumbersome computations.

  6. Radiolysis of 2,3,7,8-tetrachlorodibenzo- p-dioxin in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Mamedov, Kh. F.; Aliev, A. G.; Mamedova, N. A.; Badalova, A. R.

    2015-09-01

    The conversion of 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) in diluted aqueous solutions at different absorbed doses of ionizing radiation using the 60Co source is studied. The radiochemical yield of TCDD conversion is (0.3-1.5) × 10-5 molecules/100 eV for solutions with 0.2-2 μg/L TCDD in open cells and 2.4 × 10-5 molecules/100 eV for air-sparged 2 μg/L TCDD solutions. It is demonstrated that the absorbed dose of ionizing radiation (25 kGy) lowers the TCDD concentration in oxygen-containing aqueous solutions virtually to zero.

  7. Biomagnification of bioassay derived 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents

    USGS Publications Warehouse

    Jones, P.D.; Ankley, G.T.; Best, D. A.; Crawford, R.; DeGalan, N.; Giesy, J.P.; Kubiak, T.J.; Ludwig, J. P.; Newsted, J.L.; Tillitt, D. E.; Verbrugge, D.A.

    1993-01-01

    In recent years contamination of the Great Lakes ecosystem with planar chlorinated hydrocarbons (PCHs) has attracted considerable concern due to their known reproductive and teratogenic effects. The H4IIE bioassay has been standardized as a means of measuring the biological potency of a PCH mixture as 2,3,7,8-tetrachloro-p-dibenzodioxin equivalents (TCDD-EQ). Using this bioassay we have investigated the biomagnification of TCDD-EQ in a semi-closed ecosystem. The biomagnification of TCDD-EQ is demonstrated and results indicate that the food chain is the major pathway for TCDD-EQ through this ecosystem. The H4IIE assay system is demonstrated to be a viable integrative measure of the total concentration of TCDD-EQ in different trophic levels.

  8. Water solubility of 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Marple, L.; Brunck, R.; Throop, L.

    1986-02-01

    Vacuum deposition of a solid film onto a glass surface and equilibrium on this film with water are the basis of a method that was used to measure the water solubility of 2,3,7,8-tetrachlorodibenzo-p-dioxin. Films of both /sup 14/C-radiolabeled and unlabeled dioxin were prepared so that solubilized material could be measured by radioactivity as well as by capillary GC/LRMS techniques. The averages of solubility values for radiolabeled and unlabeled dioxin were 3.9 x 10/sup -11/ M (12.5 parts per trillion) and 6.0 x 10/sup -11/ M (19.3 parts per trillion), respectively. The solubility values lie within the values predicted from Yalkowsky's K/sub ow/-solubility equation of best fit for chlorinated hydrocarbons and the available estimates for the octanol-water partition coefficient, K/sub ow/. 11 references, 2 tables.

  9. Humanized TLR7/8 expression drives proliferative multisystemic histiocytosis in C57BL/6 mice.

    PubMed

    Snyder, Jessica M; Treuting, Piper M; Nagy, Lee; Yam, Cathy; Yi, Jaehun; Brasfield, Alicia; Nguyen, Lisa Phuong Anh; Hajjar, Adeline M

    2014-01-01

    A humanized TLR7/TLR8 transgenic mouse line was engineered for studies using TLR7/8 ligands as vaccine adjuvants. The mice developed a spontaneous immune-mediated phenotype prior to six months of age characterized by runting, lethargy, blepharitis, and corneal ulceration. Histological examination revealed a marked, multisystemic histiocytic infiltrate that effaced normal architecture. The histological changes were distinct from those previously reported in mouse models of systemic lupus erythematosus. When the mice were crossed with MyD88-/- mice, which prevented toll-like receptor signaling, the inflammatory phenotype resolved. Illness may be caused by constitutive activation of human TLR7 or TLR8 in the bacterial artificial chromosome positive mice as increased TLR7 and TLR8 expression or activation has previously been implicated in autoimmune disease. PMID:25229618

  10. 5,6,7,8-Tetrahydropyrido[4,3-d]pyrimidines as novel class of potent and highly selective CaMKII inhibitors.

    PubMed

    Asano, Shigehiro; Komiya, Masafumi; Koike, Nobuyuki; Koga, Erina; Nakatani, Shogo; Isobe, Yoshiaki

    2010-11-15

    A novel series of 5,6,7,8-tetrahydropyrido[4,3-d]pyrimidines containing substituted phenyl sulfonamide are synthesized and evaluated for their inhibitory activity against CaMKII. Substituents on the phenyl group had significant impact on CaMKII inhibition, in particular, the inhibitory activity of 8p was 25-fold higher than that of KN-93, a known CaMKII inhibitor. Michaelis-Menten analysis of a representative compound suggested that the synthesized pyrimidines are calmodulin non-competitive inhibitors. Finally, 8p exhibited more than 100-fold higher selectivity for CaMKII over five types of off-target kinases. PMID:20875738

  11. The DnaJ OsDjA7/8 is essential for chloroplast development in rice (Oryza sativa).

    PubMed

    Zhu, Xiaobo; Liang, Sihui; Yin, Junjie; Yuan, Can; Wang, Jing; Li, Weitao; He, Min; Wang, Jichun; Chen, Weilan; Ma, Bingtian; Wang, Yuping; Qin, Peng; Li, Shigui; Chen, Xuewei

    2015-12-10

    DnaJ proteins belong to chaperones of Hsp40 family that ubiquitously participate in various cellular processes. Previous studies have shown chloroplast-targeted DnaJs are involved in the development of chloroplast in some plant species. However, little is known about the function of DnaJs in rice, one of the main staple crops. In this study, we characterized a type I DnaJ protein OsDjA7/8. We found that the gene OsDjA7/8 was expressed in all collected tissues, with a priority in the vigorous growth leaf. Subcellular localization revealed that the protein OsDjA7/8 was mainly distributed in chloroplast. Reduced expression of OsDjA7/8 in rice led to albino lethal at the seedling stage. Transmission electron microscopy observation showed that the chloroplast structures were abnormally developed in the plants silenced for OsDjA7/8. In addition, the transcriptional expression of the genes tightly associated with the development of chloroplast was deeply reduced in the plants silenced for OsDjA7/8. Collectively, our study reveals that OsDjA7/8 encodes a chloroplast-localized protein and is essential for chloroplast development and differentiation in rice.

  12. Drinking-water criteria document for 2,3,7,8-tetrachlorodibenzo-p-dioxin. Draft report

    SciTech Connect

    Not Available

    1988-04-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) is one of the most toxic and environmentally stable tricyclic aromatic compounds belonging to chlorinated dibenzo-p-dioxins. 2,3,7,8-TCDD has been demonstrated to be teratogenic in rats, mice and rabbits, and feticidal in monkeys. The major toxic signs and terata observed were cleft palate in mice, edema, hemorrhage, and kidney anomalies in rats and extra ribs in rabbits. Some epidemiological studies have indicated a possible teratogenic effect in humans, but the evidence is not sufficient to reach a firm conclusion.

  13. Cooperative Weblog Learning in Higher Education: Its Facilitating Effects on Social Interaction, Time Lag, and Cognitive Load

    ERIC Educational Resources Information Center

    Huang, Tien-Chi; Huang, Yueh-Min; Yu, Fu-Yun

    2011-01-01

    This paper examines the effects of using weblog technologies to support cooperative learning in higher education. The study focused on the effects of features embedded in weblogs on social interactions, time lags, and cognitive loads. A quasi-experimental control-group research design was adopted. The participants were 115 undergraduates who were…

  14. Impact of the Headscarf Ban Policy on the Identity Development of Part-Time Unveilers in Turkish Higher Education

    ERIC Educational Resources Information Center

    Seggie, Fatma Nevra; Austin, Ann E.

    2010-01-01

    This qualitative study examines the impact of the Turkish higher education headscarf ban policy on the plural self-identities (i.e., as Turkish citizens, as Muslims, and as females) of part-time unveilers, female students who cover their hair in their private life but who remove the headscarf (or conceal it to appear unveiled) while at a Turkish…

  15. Utilizing Social Networks in Times of Crisis: Understanding, Exploring and Analyzing Critical Incident Management at Institutions of Higher Education

    ERIC Educational Resources Information Center

    Asselin, Martha Jo

    2012-01-01

    With the rising number of major crises on college campuses today (Security on Campus Inc., 2009), institutions of higher education can benefit from understanding of how social networks may be used in times of emergency. What is currently known about the usage of social networks is not integral to the current practices of crisis management that are…

  16. Modern U-Pb chronometry of meteorites: advancing to higher time resolution reveals new problems

    USGS Publications Warehouse

    Amelin, Y.; Connelly, J.; Zartman, R.E.; Chen, J.-H.; Gopel, C.; Neymark, L.A.

    2009-01-01

    In this paper, we evaluate the factors that influence the accuracy of lead (Pb)-isotopic ages of meteorites, and may possibly be responsible for inconsistencies between Pb-isotopic and extinct nuclide timescales of the early Solar System: instrumental mass fractionation and other possible analytical sources of error, presence of more than one component of non-radiogenic Pb, migration of ancient radiogenic Pb by diffusion and other mechanisms, possible heterogeneity of the isotopic composition of uranium (U), uncertainties in the decay constants of uranium isotopes, possible presence of "freshly synthesized" actinides with short half-life (e.g. 234U) in the early Solar System, possible initial disequilibrium in the uranium decay chains, and potential fractionation of radiogenic Pb isotopes and U isotopes caused by alpha-recoil and subsequent laboratory treatment. We review the use of 232Th/238U values to assist in making accurate interpretations of the U-Pb ages of meteorite components. We discuss recently published U-Pb dates of calcium-aluminum-rich inclusions (CAIs), and their apparent disagreement with the extinct nuclide dates, in the context of capability and common pitfalls in modern meteorite chronology. Finally, we discuss the requirements of meteorites that are intended to be used as the reference points in building a consistent time scale of the early Solar System, based on the combined use of the U-Pb system and extinct nuclide chronometers.

  17. Higher dimensional analysis shows reduced dynamism of time-varying network connectivity in schizophrenia patients.

    PubMed

    Miller, Robyn L; Yaesoubi, Maziar; Calhoun, Vince D

    2014-01-01

    Assessments of functional connectivity between brain networks is a fixture of resting state fMRI research. Until very recently most of this work proceeded from an assumption of stationarity in resting state network connectivity. In the last few years however, interest in moving beyond this simplifying assumption has grown considerably. Applying group temporal independent component analysis (tICA) to a set of time-varying functional network connectivity (FNC) matrices derived from a large multi-site fMRI dataset (N=314; 163 healthy, 151 schizophrenia patients), we obtain a set of five basic correlation patterns (component spatial maps (SMs)) from which observed FNCs can be expressed as mutually independent linear combinations, i.e., the coefficient on each SM in the linear combination is maximally independent of the others. We study dynamic properties of network connectivity as they are reflected in this five-dimensional space, and report stark differences in connectivity dynamics between schizophrenia patients and healthy controls. We also find that the most important global differences in FNC dynamism between patient and control groups are replicated when the same dynamical analysis is performed on sets of correlation patterns obtained from either PCA or spatial ICA, giving us additional confidence in the results.

  18. The TLR7/8 ligand resiquimod targets monocyte-derived dendritic cell differentiation via TLR8 and augments functional dendritic cell generation.

    PubMed

    Hackstein, Holger; Knoche, Angela; Nockher, Angelika; Poeling, Jochen; Kubin, Thomas; Jurk, Marion; Vollmer, Jörg; Bein, Gregor

    2011-01-01

    Imidazoquinolone compounds, such as resiquimod are Toll-like receptor (TLR) 7/8 ligands representing novel immune response modifiers undergoing clinical testing. Resiquimod has been reported to modulate conventional human monocyte-derived DC (moDC) differentiation, but the role of TLR7 and TLR8 is unclear. We directly dissected the TLR7- and TLR8-dependency by employing selective TLR7 ligands and resiquimod-coculture experiments with inhibitory oligonucleotides (iODN) suppressing TLR7, TLR7+8 or TLR7+8+9. Selective TLR7 ligands did not affect conventional moDC differentiation as analyzed by CD14/CD1a expression. iODN experiments confirmed that resiquimod's effects during DC differentiation were antagonized only with TLR8 iODNs. Direct comparison of resiquimod DC with TLR7- and control-DC revealed significantly higher T-cell costimulatory molecule and MHC class II expression. Resiquimod DC promoted significantly stronger allogeneic T-cell proliferation and stronger naïve CD4(+) T-cell proliferation. These results indicate the relevance of TLR8 for human monocyte-derived DC differentiation and maturation and may be relevant for clinical trials employing resiquimod. PMID:21889130

  19. Early post-seismic deformation due to the 2015 M7.8 Gorkha (Nepal) earthquake: Constraints on rheology of the Tibetan lithosphere

    NASA Astrophysics Data System (ADS)

    Fialko, Y. A.; Wang, K.

    2015-12-01

    Over the last decade several major earthquakes have occurred on faultsbounding the Tibetan plateau, including the 2005 M7.6 Kashmir(Pakistan), the 2008 M7.8 Wenchuan (China), and the 2015 M7.8 Gorkha(Nepal) earthquakes. Time-dependent surface deformation followingthese earthquakes provides important constraints on the effectiverheology of the lower crust and upper mantle beneath Tibet. Theepicentral area of the 2015 Gorkha (Nepal) earthquake has beenexceptionally well imaged by several Interferometric SyntheticAperture Radar (InSAR) satellites including ALOS-2 (Japanese SpaceAgency) and Sentinel-1 (European Space Agency) missions. We willpresent observations of surface deformation in the early (severalmonths) postseismic period following the 2015 Gorkha earthquake, andcompare surface deformation data to numerical models of postseismictransients assuming various relaxation mechanisms. We will alsocompare the postseismic deformation data from different earthquakes atthe boundaries of the Tibetan Plateau to evaluate the effects oflateral heterogeneities in rheological properties of the ductilesubstrate.

  20. Growth and characterization of 7,7,8,8-tetracyano-quinodimethane crystals on chemical vapor deposition graphene

    NASA Astrophysics Data System (ADS)

    Black, Andrés; Jiménez, Fernando; Bernardo-Gavito, Ramón; Casado, Santiago; Granados, Daniel; Vázquez de Parga, Amadeo L.

    2016-11-01

    Chemical functionalization of graphene could pave the way for favorably modifying its already remarkable properties. Organic molecules have been utilized to this end as a way to alter graphene's structural, chemical, electrical, optical and even magnetic properties. One such promising organic molecule is 7,7,8,8-tetracyano-quinodimethane (TCNQ), a strong electron acceptor which has been shown to be an effective p-dopant of graphene. This study explores the thermal evaporation of TCNQ onto graphene transferred onto SiO2/Si substrates. Using two different home-made thermal evaporators, a wide range of TCNQ growth regimes are explored, from thin films to bulk crystals. The resulting graphene/TCNQ structure is characterized via optical microscopy, Raman spectroscopy and atomic force microscopy (AFM). Films are found to be comprised of TCNQ and the oxidized product of TCNQ, α,α-dicyano-p-toluoylcyanide (DCTC), which confirms the electron charge transfer from graphene to the TCNQ films. AFM measurements of these films show that after forming a rather smooth layer covering the graphene surface, small clusters start to form. For higher TCNQ coverage, the clusters agglomerate, becoming quite large in size and forming ripples or wrinkles across the surface.

  1. Embryo toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to the wood duck (Aix sponsa)

    USGS Publications Warehouse

    Augspurger, T.P.; Tillitt, D.E.; Bursian, S.J.; Fitzgerald, S.D.; Hinton, D.E.; Di Giulio, R.T.

    2008-01-01

    We examined the sensitivity of the wood duck (Aix sponsa) embryo to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by injecting the toxicant into their eggs. Six groups of wood duck eggs (n = 35 to 211 per trial) were injected with 0 to 4600 pg TCDD/g egg between 2003 and 2005. Injections were made into yolk prior to incubation, and eggs were subsequently incubated and assessed weekly for mortality. Significant TCDD-induced mortality was not observed through day 25 (90% of incubation). Liver, heart, eye, and brain histology were generally unremarkable. Hepatic ethoxyresorufin-O-deethylase activity, a biomarker of dioxin-like compound exposure, was induced by 12-fold in the 4600 pg/g treatment relative to controls. The median lethal dose for chicken (Gallus domesticus) eggs we dosed identically to wood duck eggs was about 100 pg/g, similar to other assessments of chickens. Among dioxin-like compound embryo lethality data for 15 avian genera, the wood duck 4600 pg/g no-observed-effect level ranks near the middle. Because no higher doses were tested, wood ducks may be like other waterfowl (order Anseriformes), which are comparatively tolerant to embryo mortality from polychlorinated dibenzo-p-dioxins and dibenzofurans when exposed by egg injection. ?? 2008 US Government.

  2. Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on development of anuran amphibians

    SciTech Connect

    Jung, R.E.; Walker, M.K.

    1997-02-01

    The authors exposed anuran eggs and tadpoles to vehicle control (0.7% acetone) or waterborne [{sup 3}H]2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) for 24 h and subsequently raised them in clean water. Neither American toads nor green frogs exhibited TCDD-related mortality, but leopard frogs showed significantly increased mortality over controls. Eggs and tadpoles eliminated TCDD relatively quickly compared with published data for other vertebrates, with t{sub {1/2}} of 1 to 5 d (American toad), 2 to 7 d (leopard frog), and 4 to 6 d (green frog). Elimination rates were slowest for tadpoles fed nothing, fastest for those fed a low-fat diet, and intermediate for those fed a high-fat diet. Although not significant, American toads exposed to {ge}0.03 {micro}g TCDD/L appeared to metamorphose earlier, and those exposed to higher TCDD treatments appeared to metamorphose at a larger body mass than controls. Comparisons of these results with studies of fish early life stages suggest that anuran eggs and tadpoles eliminate TCDD more rapidly and are 100- to 1,000-fold less sensitive to its deleterious effects during development. These differences may be related to differences in metabolic rate, patterns of lipid storage and utilization, and aryl hydrocarbon receptor binding and signal transduction.

  3. Reading and writing performances of children 7-8 years of age with developmental coordination disorder in Taiwan.

    PubMed

    Cheng, Hsiang-Chun; Chen, Jenn-Yeu; Tsai, Chia-Liang; Shen, Miau-Lin; Cherng, Rong-Ju

    2011-01-01

    Developmental coordination disorder (DCD) refers to a delay in motor development that does not have any known medical cause. Studies conducted in English speaking societies have found that children with DCD display a higher co-occurrence rate of learning difficulties (e.g., problems in reading and writing) than typically developing (TD) children. The present study examined the reading and writing performance of school-aged children with DCD and TD children in Taiwan to determine whether reading and writing difficulties also co-occur with DCD in a non-English speaking society. The Chinese Reading Achievement Test and the Basic Reading and Writing Test were administered to 37 children with DCD (7.8 ± 0.6 years) and 93 TD children (8.0 ± 0.7 years). Children with DCD had significantly lower writing composite scores than TD children on the Basic Reading and Writing Test (105.9 ± 20.0 vs. 114.4 ± 19.9). However, there were no significant differences between children with DCD and TD children in their scores on the Chinese Reading Achievement Test and in their reading composite scores on the Basic Reading and Writing Test. These results contrasted interestingly with those obtained from English-speaking children: English-speaking DCD children showed poorer reading and poorer writing than English-speaking TD children. The possibility that the logographic nature of the Chinese script might have protected the DCD children against additional reading difficulty is discussed.

  4. Age- and Concentration-Dependent Elimination Half-Life of 2,3,7,8-Tetrachlorodibenzo-p-dioxin in Seveso Children

    PubMed Central

    Kerger, Brent D.; Leung, Hon-Wing; Scott, Paul; Paustenbach, Dennis J.; Needham, Larry L.; Patterson, Donald G.; Gerthoux, Pier M.; Mocarelli, Paolo

    2006-01-01

    Objective Pharmacokinetic and statistical analyses are reported to elucidate key variables affecting 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) elimination in children and adolescents. Design We used blood concentrations to calculate TCDD elimination half-life. Variables examined by statistical analysis include age, latency from exposure, sex, TCDD concentration and quantity in the body, severity of chloracne response, body mass index, and body fat mass. Participants Blood was collected from 1976 to 1993 from residents of Seveso, Italy, who were < 18 years of age at the time of a nearby trichlorophenol reactor explosion in July 1976. Results TCDD half-life in persons < 18 years of age averaged 1.6 years while those ≥18 years of age averaged 3.2 years. Half-life is strongly associated with age, showing a cohort average increase of 0.12 year half-life per year of age or time since exposure. A significant concentration-dependency is also identified, showing shorter half-lives for TCDD concentrations > 400 ppt for children < 12 years of age and 700 ppt when including adults. Moderate correlations are also observed between half-life and body mass index, body fat mass, TCDD mass, and chloracne response. Conclusions Children and adolescents have shorter TCDD half-lives and a slower rate of increase in half-life than adults, and this effect is augmented at higher body burdens. Relevance Modeling of TCDD blood concentrations or body burden in humans should take into account the markedly shorter elimination half-life observed in children and adolescents and concentration-dependent effects observed in persons > 400–700 ppt. PMID:17035149

  5. Production and dechlorination of 2,3,7,8-tetrachlorodibenzo-p-dioxin in historically-contaminated estuarine sediments

    SciTech Connect

    Albrecht, I.D.; Barkovskii, A.L.; Adriaens, P.

    1999-03-01

    Polychlorinated dibenzo-p-dioxins (PCDD) are ubiquitous and considered to be unreactive to biotic and abiotic transformation processes. Here the authors demonstrate that sediment-associated 2,3,7,8-substituted dioxin residues in general, and 2,3,7,8-TCDD in particular, are in a state of flux, as they are produced from peri-dechlorination of octaCDD, and further laterally dechlorinated in 2-MCDD. This reaction can be stimulated in the presence of organic acids, 2-monobromodibenzo-p-dioxin (2-MBDD) and hydrogen, which result in the production of HpCDD, 2,3,7,8-TCDD, and 2-MCDD, respectively. The results indicate that dechlorination of 2,3,7,8-TCDD is not likely a rate-limiting step in the hydrogen-stimulated reaction, which presents a potential strategy to decontaminate dioxin-contaminated environments.

  6. Interference between oculomotor and postural tasks in 7-8-year-old children and adults.

    PubMed

    Legrand, Agathe; Doré Mazars, Karine; Lemoine, Christelle; Nougier, Vincent; Olivier, Isabelle

    2016-06-01

    Several studies in adults having observed the effect of eye movements on postural control provided contradictory results. In the present study, we explored the effect of various oculomotor tasks on postural control and the effect of different postural tasks on eye movements in eleven children (7.8 ± 0.5 years) and nine adults (30.4 ± 6.3 years). To vary the difficulty of the oculomotor task, three conditions were tested: fixation, prosaccades (reactive saccades made toward the target) and antisaccades (voluntary saccades made in the direction opposite to the visual target). To vary the difficulty of postural control, two postural tasks were tested: Standard Romberg (SR) and Tandem Romberg (TR). Postural difficulty did not affect oculomotor behavior, except by lengthening adults' latencies in the prosaccade task. For both groups, postural control was altered in the antisaccade task as compared to fixation and prosaccade tasks. Moreover, a ceiling effect was found in the more complex postural task. This study highlighted a cortical interference between oculomotor and postural control systems.

  7. Oxidative stress in lake sturgeon orally exposed to 2,3,7,8-tetrachlorodibenzofuran

    SciTech Connect

    Palace, V.P.; Dick, T.A.; Brown, S.B.; Baron, C.L.; Klaverkamp, J.F. |

    1994-12-31

    Juvenile lake sturgeon were orally dosed with gelatin containing nominal concentrations of 0, 0.16 or 1.6 ng 2,3,7,8-tetrachlorodibenzofuran (TCDF)/Kg fish weight. Liver, kidney and blood were collected 10 and 27 days after exposure. Phase 1 (mixed function oxidase MFO) and Phase 2 (glucuronyltransferase) enzyme activities were determined in liver. In addition, concentrations of nonenzymatic (ascorbic acid, tocopherol, retinoids) and enzymatic (superoxide dismutase, catalase, glutathione peroxidase) antioxidant parameters were quantified in liver and kidney. TCDF concentrations were elevated in liver and kidney of both dose groups at 10 and 27 days. However, lower tissue concentrations of TCDF at 27 days compared with 10 day exposures, as well as the presence of polar metabolites in bile, suggest rapid metabolism and clearance of the contaminant. Phase 1 and Phase 2 enzyme activities were induced in a dose dependent manner with activities at the two sample periods reflecting the different TCDF concentrations. Indicators of oxidative stress responded similarly.

  8. Frequency analysis of the 7-8 December 2010 extreme precipitation in the Panama Canal Watershed

    NASA Astrophysics Data System (ADS)

    Shamir, Eylon; Georgakakos, Konstantine P.; Murphy, Michael J.

    2013-02-01

    SummaryThe 7-8 December 2010 rainfall event in Panama produced record rainfall and streamflow that are about twice as much as for the previously observed large event in record. In this study we ask whether before the occurrence of this rainfall event, a return period estimate using the historical record and the commonly used statistical asymptotic distributions of extreme values could have indicated that such an event is probable. We examined the daily and 24-h mean areal rainfall over the entire Panama Canal Watershed with the Generalized Extreme Value, Gumbel, and Generalized Pareto distributions using the maximum likelihood approach for the parameter and uncertainty bounds estimation. We found that the solutions that maximized the log likelihood for these three distributions yield return period estimates that are larger than 2000 years. These return periods imply that the 2010 rainfall event was practically unforeseen. It is only the careful implementation of these distributions with full uncertainty analysis to define confidence intervals that yields estimates of return periods with substantial probabilities for such an event to occur. The GEV was found to be the most adequate distribution for this analysis, and the commonly-used Gumbel distribution, although indicated a good fit to the annual maxima series, attributed an extremely low probability for the occurrence of this event.

  9. 8-oxo-7,8-dihydroguanine: Link to gene expression, aging and defense against oxidative stress

    PubMed Central

    Radak, Zsolt; Boldogh, Istvan

    2010-01-01

    The one-electron oxidation product of guanine 8-oxo-7,8-dihydroguanine (8-oxoG) is an abundant lesion in genomic, mitochondrial and telomeric DNA and RNA. It is considered to be a marker of oxidative stress that preferentially accumulates at the 5’ end of guanine strings in the DNA helix, guanine quadruplexes and in RNA molecules. 8-oxoG has a lower oxidation potential compared to guanine, thus it is susceptible to oxidation/reduction and along with its redox products, is traditionally considered to be a major genotoxic/mutagenic DNA base lesion. It does not change the architecture of the DNA double helix and it is specifically recognized and excised by 8-oxoguanine DNA glycosylase (OGG1) during the DNA base excision repair pathway. OGG1 null animals accumulate excess levels of 8-oxoG in their genome, while they do not have shorter lifespan, nor exhibit severe pathological symptoms including tumor formation. In fact they are increasingly resistant to inflammation. Here we address rarely considered significance of 8-oxoG such as its optimal level in the DNA and RNA in a given condition, essentiality for normal cellular physiology, evolutionary role, ability to soften the effects of oxidative stress in DNA, harmful consequences of its repair, as well as its importance in transcriptional initiation and chromatin relaxation. PMID:20483371

  10. Phase transitions between lower and higher level management learning in times of crisis: an experimental study based on synergetics.

    PubMed

    Liening, Andreas; Strunk, Guido; Mittelstadt, Ewald

    2013-10-01

    Much has been written about the differences between single- and double-loop learning, or more general between lower level and higher level learning. Especially in times of a fundamental crisis, a transition between lower and higher level learning would be an appropriate reaction to a challenge coming entirely out of the dark. However, so far there is no quantitative method to monitor such a transition. Therefore we introduce theory and methods of synergetics and present results from an experimental study based on the simulation of a crisis within a business simulation game. Hypothesized critical fluctuations - as a marker for so-called phase transitions - have been assessed with permutation entropy. Results show evidence for a phase transition during the crisis, which can be interpreted as a transition between lower and higher level learning.

  11. Continuous higher-order sliding mode control with time-varying gain for a class of uncertain nonlinear systems.

    PubMed

    Han, Yaozhen; Liu, Xiangjie

    2016-05-01

    This paper presents a continuous higher-order sliding mode (HOSM) control scheme with time-varying gain for a class of uncertain nonlinear systems. The proposed controller is derived from the concept of geometric homogeneity and super-twisting algorithm, and includes two parts, the first part of which achieves smooth finite time stabilization of pure integrator chains. The second part conquers the twice differentiable uncertainty and realizes system robustness by employing super-twisting algorithm. Particularly, time-varying switching control gain is constructed to reduce the switching control action magnitude to the minimum possible value while keeping the property of finite time convergence. Examples concerning the perturbed triple integrator chains and excitation control for single-machine infinite bus power system are simulated respectively to demonstrate the effectiveness and applicability of the proposed approach. PMID:26920085

  12. Continuous higher-order sliding mode control with time-varying gain for a class of uncertain nonlinear systems.

    PubMed

    Han, Yaozhen; Liu, Xiangjie

    2016-05-01

    This paper presents a continuous higher-order sliding mode (HOSM) control scheme with time-varying gain for a class of uncertain nonlinear systems. The proposed controller is derived from the concept of geometric homogeneity and super-twisting algorithm, and includes two parts, the first part of which achieves smooth finite time stabilization of pure integrator chains. The second part conquers the twice differentiable uncertainty and realizes system robustness by employing super-twisting algorithm. Particularly, time-varying switching control gain is constructed to reduce the switching control action magnitude to the minimum possible value while keeping the property of finite time convergence. Examples concerning the perturbed triple integrator chains and excitation control for single-machine infinite bus power system are simulated respectively to demonstrate the effectiveness and applicability of the proposed approach.

  13. A successful resimulation of the 7-8 January 2005 winter storm through initial potential vorticity modification in sensitive regions

    NASA Astrophysics Data System (ADS)

    Røsting, B.; Kristjánsson, J. E.

    2008-08-01

    In this study, we present an example of the benefit that can be achieved from carefully designed manual modification of a numerical weather prediction analysis. The case to be investigated is the severe winter storm of 7-8 January 2005, affecting the North Sea and southern Scandinavia. Modifications of potential vorticity (PV) fields according to features in water vapour (WV) images are combined with information from singular vectors (SV) in an attempt to improve the initial state over data sparse regions west of the British Isles. The apparent mismatch between features in the WV image and the upper level PV anomalies in the numerical analysis is corrected, mainly at levels indicated as sensitive by the fastest growing SVs, in order to maximize the impact on the simulation. Model reruns, based on the inverted corrected PV fields, were then performed. The manual correction of PV fields led to a substantial improvement of the simulations of the storm. The PV modifications were carried out by a digital analysis system, implemented at the Norwegian Meteorological Institute. This system allows the PV modifications to be done interactively within an operational time limit.

  14. Toxicity and bioaccumulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by Chironomus tentans and Lumbriculus variegatus

    SciTech Connect

    West, C.W.; Ankley, G.T.; Elonen, G.E.; Phipps, G.W.; Fernandez, J.D.; Libal, J.J.; Nessa, D.

    1994-12-31

    Invertebrate exposure to 2,3,7,8-TCDD is important, not necessarily because of their sensitivity (which appears to be less than that of fish) , but as a vector from chemical reservoirs in sediments, through the food chain, to sensitive species. Chironomus tentans and Lumbriculus variegatus are not only vectors for TCDD to fish species, but C. tentans may also be a direct vector to avian species which feed upon emergent insects. For this reason determination of the kinetics of TCDD uptake by invertebrates is important, especially for those with short life spans such as midges, or those that reproduce as rapidly as oligochaetes. In these experiments, these two species were fed contaminated food at three different TCDD levels spanning three orders of magnitude. Tissue residue levels were measured over a time period which included several different life stages and points in the reproductive cycle of the two species and uptake and deputation rates determined. As expected, no significant impacts of TCDD on growth, reproduction or biomass of the invertebrates were observed. From this information predictions can be made on bioaccumulation of TCDD from differing levels of contamination, and potential food chain transfer of the compound to more sensitive species.

  15. The ShakeOut scenario: A hypothetical Mw7.8 earthquake on the Southern San Andreas Fault

    USGS Publications Warehouse

    Porter, K.; Jones, L.; Cox, D.; Goltz, J.; Hudnut, K.; Mileti, D.; Perry, S.; Ponti, D.; Reichle, M.; Rose, A.Z.; Scawthorn, C.R.; Seligson, H.A.; Shoaf, K.I.; Treiman, J.; Wein, A.

    2011-01-01

    In 2008, an earthquake-planning scenario document was released by the U.S. Geological Survey (USGS) and California Geological Survey that hypothesizes the occurrence and effects of a Mw7.8 earthquake on the southern San Andreas Fault. It was created by more than 300 scientists and engineers. Fault offsets reach 13 m and up to 8 m at lifeline crossings. Physics-based modeling was used to generate maps of shaking intensity, with peak ground velocities of 3 m/sec near the fault and exceeding 0.5 m/sec over 10,000 km2. A custom HAZUS??MH analysis and 18 special studies were performed to characterize the effects of the earthquake on the built environment. The scenario posits 1,800 deaths and 53,000 injuries requiring emergency room care. Approximately 1,600 fires are ignited, resulting in the destruction of 200 million square feet of the building stock, the equivalent of 133,000 single-family homes. Fire contributes $87 billion in property and business interruption loss, out of the total $191 billion in economic loss, with most of the rest coming from shakerelated building and content damage ($46 billion) and business interruption loss from water outages ($24 billion). Emergency response activities are depicted in detail, in an innovative grid showing activities versus time, a new format introduced in this study. ?? 2011, Earthquake Engineering Research Institute.

  16. Toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to brook trout (salvelinus fontinalis) during early development

    SciTech Connect

    Walker, M.K.; Peterson, R.E. )

    1994-05-01

    The sensitivity of early life stages of brook trout (Salvelinus fontinalis) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxicity was investigated. Newly fertilized eggs were exposed for 48 h to water containing either acetone or a range of concentrations of [[sup 3]H]TCDD dissolved in acetone. Eggs were then transferred to TCDD-free water and observed through development. TCDD concentrations of 101 to 470 pg/g in the eggs caused dose-related increases in sac-fry mortality associated with yolk-sac edema, hemorrhages, and arrested development. These signs of TCDD-induced toxicity resemble blue-sac disease. The NOELs and LOELs for sac-fry mortality were 135 and 185 pg TCDD/g egg, respectively, whereas the LD50 and LD100 were 200 and 324 pg/g egg, respectively. The time course and signs of TCDD toxicity to brook trout during early development are essentially identical to those observed in both rainbow trout and lake trout following TCDD exposure of their eggs via water or injection, and in lake trout exposed to maternally derived TCDD. Brook trout sac fry are intermediate in sensitivity to TCDD-induced lethality compared to lake trout and rainbow trout.

  17. Broadband simulations for Mw 7.8 southern san andreas earthquakes: Ground motion sensitivity to rupture speed

    USGS Publications Warehouse

    Graves, R.W.; Aagaard, B.T.; Hudnut, K.W.; Star, L.M.; Stewart, J.P.; Jordan, T.H.

    2008-01-01

    Using the high-performance computing resources of the Southern California Earthquake Center, we simulate broadband (0-10 Hz) ground motions for three Mw 7.8 rupture scenarios of the southern San Andreas fault. The scenarios incorporate a kinematic rupture description with the average rupture speed along the large slip portions of the fault set at 0.96, 0.89, and 0.84 times the local shear wave velocity. Consistent with previous simulations, a southern hypocenter efficiently channels energy into the Los Angeles region along the string of basins south of the San Gabriel Mountains. However, we find the basin ground motion levels are quite sensitive to the prescribed rupture speed, with peak ground velocities at some sites varying by over a factor of two for variations in average rupture speed of about 15%. These results have important implications for estimating seismic hazards in Southern California and emphasize the need for improved understanding of earthquake rupture processes. Copyright 2008 by the American Geophysical Union.

  18. The 16 April 2013 Mw7.8 Ghosht, Iran earthquake

    NASA Astrophysics Data System (ADS)

    Ashtari Jafari, Mohammad

    2014-06-01

    On Tuesday 16 April 2013 at 10:44:22 UTC, a strong Mw = 7.8 earthquake shook not only Iran but also southwestern cities of Asia and southern Persian Gulf countries. This event occurred in a sparsely populated mountain and range region near a small town called Ghosht (located in Iran) but left destructions and causalities around the city of Mashkel in Pakistan. It was followed by a medium sized Mw = 5.7 aftershock on 17 April 2013 without any reported destructions or causalities. The regional tectonics is under the influence of multiple convergences between the Persian Gulf plate, Indian and Eurasian plates. We applied deviatoric inversion to search for the best-fitted moment tensor and dislocation grid search to illustrate the best source mechanism by grid search over double couple fault plane parameters. Deviatoric inversion found 39% of CLVD for the mainshock and 5% of CLVD for its following aftershock. This CLVD component may be related to that zone of the subduction where the sinking slab is down going under its density and cause normal mechanism. The best-fitted double couple after dislocation grid search estimated: strike 75, dip 35, rake -75 (all in degree) and Mw = 7.66, for the mainshock and strike 80, dip 40, rake -90 (all in degree) and Mw = 5.53 for its aftershock. According to seismicity distribution there exist two types of seismicity: (1) crustal seismic activity band near Makran coasts (above 50 km depth) and (2) under crustal band (between 50 km and 150 km) plus a gap of seismicity between Makran and the rest of the Persian Plateau.

  19. Metabolism and disposition of 2,3,7,8-tetrachlorodibenzo-p-dioxin in guinea pigs

    SciTech Connect

    Olson, J.R.

    1986-09-15

    Marked interspecies variability exists in the acute toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), with the guinea pig being the mammalian species most sensitive to the acute toxicity of TCDD. The metabolism and disposition of TCDD was investigated in guinea pigs for 45 days following a single exposure to purified (/sup 3/H)TCDD (0.56 microgram/kg, ip). Guinea pigs included in the toxicokinetic study gained body weight, maintained a normal relative body composition, and exhibited no gross signs of toxicity during the 45-day study. Approximately 36% of the dose of TCDD-derived /sup 3/H remained in the adipose tissue at 45 days following exposure to (/sup 3/H)TCDD, while the liver, pelt, and skeletal muscle and carcass each contained about 7% of the administered dose. Although most of the TCDD-derived radioactivity in liver, kidney, perirenal adipose tissue, and skeletal muscle represented unchanged TCDD, from 4 to 28% of the /sup 3/H was associated with metabolites of TCDD. This unexpected finding suggests that TCDD metabolites are not efficiently excreted from guinea pigs. The urinary and fecal excretion of TCDD-derived radioactivity followed apparent first-order kinetics, with an elimination half-life of 93.7 +/- 15.5 days (mean +/- SD). HPLC analysis of urine and bile from (/sup 3/H)TCDD-treated guinea pigs showed that all of the radioactivity represented metabolites of TCDD, indicating that these routes of elimination are dependent on prior metabolism of TCDD. However, 70 to 90% of the radioactivity in fecal samples was found to represent unmetabolized TCDD throughout the 45-day excretion study. The presence of TCDD in feces and its absence in bile suggest that the fecal excretion of unchanged TCDD resulted from the direct intestinal elimination of the lipophilic toxin.

  20. The 7-8 August 2008 eruption of Kasatochi Volcano, central Aleutian Islands, Alaska

    NASA Astrophysics Data System (ADS)

    Waythomas, Christopher F.; Scott, William E.; Prejean, Stephanie G.; Schneider, David J.; Izbekov, Pavel; Nye, Christopher J.

    2010-12-01

    Kasatochi volcano in the central Aleutian Islands erupted unexpectedly on 7-8 August 2008. Kasatochi has received little study by volcanologists and has had no confirmed historical eruptions. The island is an important nesting area for seabirds and a long-term biological study site of the U.S. Fish and Wildlife Service. After a notably energetic preeruptive earthquake swarm, the volcano erupted violently in a series of explosive events beginning in the early afternoon of 7 August. Each event produced ash-gas plumes that reached 14-18 km above sea level. The volcanic plume contained large amounts of SO2 and was tracked around the globe by satellite observations. The cumulative volcanic cloud interfered with air travel across the North Pacific, causing many flight cancelations that affected thousands of travelers. Visits to the volcano in 2008-2009 indicated that the eruption generated pyroclastic flows and surges that swept all flanks of the island, accumulated several tens of meters of pyroclastic debris, and increased the diameter of the island by about 800 m. Pyroclastic flow deposits contain abundant accidental lithic debris derived from the inner walls of the Kasatochi crater. Juvenile material is crystal-rich silicic andesite that ranges from slightly pumiceous to frothy pumice. Fine-grained pyroclastic surge and fall deposits with accretionary lapilli cover the lithic-rich pyroclastic flow deposits and mark a change in eruptive style from episodic explosive activity to more continuous ash emission with smaller intermittent explosions. Pyroclastic deposits completely cover the island, but wave erosion and gully development on the flanks have begun to modify the surface mantle of volcanic deposits.

  1. Is the general conclusion justified that higher applicable field strength results in shorter analysis time with organic solvents in CE?

    PubMed

    Téllez, Adolfo; Kenndler, Ernst

    2009-11-01

    In this paper, a widespread opinion in CE with organic solvents for the background electrolyte is critically questioned, namely that in general a shorter analysis time can be achieved due to the higher field strength applicable compared with aqueous electrolyte systems. This view, common in the literature, is based on the supposition that the conductance in organic solvents is lower than in water. Indeed in many organic solvents with higher viscosity than water lower ion mobility is observed, and higher fields can be applied in these cases. However, in this paper the problem is sharper defined and treated two-fold: (i) in all solvents conditions are such that either the same electric power is generated, or (ii) the same temperature increase is taken into account. It was shown that for the same electric power the field strength in the organic solvent can be changed to a less extent than the ionic mobility changes. As a result, the migration velocity of the analytes is lower and the analysis time is longer in most organic solvents compared with water; acetonitrile (MeCN) is an exception (in this solvent the mobilities are higher than in water). The more stringent treatment of the problem takes an equal temperature increase due to Joule heating into account rather than equal electric power. The temperature increase in the capillary depends on the thermal conductivity of the solvent, which is only about one-third of that of water for organic liquids. The consequence is that in none of the organic solvent systems a shorter analysis time can be achieved compared with water (given that the experimental conditions are comparable, e.g. zero EOF). The theoretical predictions were confirmed by measurements with water, methanol, propylenecarbonate, and MeCN as solvents.

  2. 2,3,7,8-Tetrachlorodibenzo-p-dioxin plasma levels in Seveso 20 years after the accident.

    PubMed

    Landi, M T; Consonni, D; Patterson, D G; Needham, L L; Lucier, G; Brambilla, P; Cazzaniga, M A; Mocarelli, P; Pesatori, A C; Bertazzi, P A; Caporaso, N E

    1998-05-01

    In 1976, near Seveso, Italy, an industrial accident caused the release of large quantities of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) into the atmosphere, resulting in the highest levels of the toxicant ever recorded in humans. The contaminated area was divided into three zones (A, B, R) corresponding to decreasing TCDD levels in soil, and cohort including all residents was enumerated. The population of the surrounding noncontaminated area (non-ABR) was chosen as referent population. Two decades after the accident. plasma TCDD levels were measured in 62 subjects randomly sampled from the highest exposed zones (A and B) and 59 subjects from non-ABR, frequency matched for age, gender, and cigarette smoking status. Subjects living in the exposed areas have persistently elevated plasma TCDD levels (range = 1.2-89.9 ppt; geometric mean = 53.2 and 11.0 ppt for Zone A and Zone B, respectively). Levels significantly decrease by distance from the accident site (p = 0.0001), down to general population values (4.9 ppt) in non-ABR, thus validating the original zone classification based on environmental measurements. Women have higher TCDD levels than men in the entire study area (p = 0.0003 in Zone B; p = 0.007 in non-ABR). This gender difference persists after adjustment for location within the zone, consumption of meat derived from locally raised animals, age, body mass index, and smoking. There is no evidence for a gender difference in exposure, so variation in metabolism or elimination due to body fat or hormone-related factors may explain this finding. Elevated TCDD levels in women may contribute to adverse reproductive, developmental, and cancer outcomes.

  3. A High-Order, Linear Time-Invariant Model for Application to Higher Harmonic Control and Flight Control System Interaction

    NASA Technical Reports Server (NTRS)

    Cheng, Rendy P.; Tischler, Mark B.; Celi, Roberto

    2006-01-01

    This research describes a new methodology for the extraction of a high-order, linear time invariant model, which allows the periodicity of the helicopter response to be accurately captured. This model provides the needed level of dynamic fidelity to permit an analysis and optimization of the AFCS and HHC algorithms. The key results of this study indicate that the closed-loop HHC system has little influence on the AFCS or on the vehicle handling qualities, which indicates that the AFCS does not need modification to work with the HHC system. However, the results show that the vibration response to maneuvers must be considered during the HHC design process, and this leads to much higher required HHC loop crossover frequencies. This research also demonstrates that the transient vibration responses during maneuvers can be reduced by optimizing the closed-loop higher harmonic control algorithm using conventional control system analyses.

  4. Immunological markers among workers exposed to 2,3,7,8- tetrachlorodibenzo-p-dioxin

    PubMed Central

    Halperin, W.; Vogt, R.; Sweeney, M. H.; Shopp, G.; Fingerhut, M.; Petersen, M.

    1998-01-01

    OBJECTIVES: To examine the association of immune cell number and function with occupational exposure to substances contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). METHODS: A cross sectional medical survey. The exposed participants were employed at two chemical plants between 1951 and 1972 in the manufacture of 2,4,5- trichlorophenate and its derivatives. The reference group consisted of people with no occupational exposure to phenoxy herbicides who lived within the communities of the workers. Data from a total of 259 workers and 243 unexposed referents were included in the analysis of immune function. Laboratory tests for immune status included enumeration of circulating leukocyte and lymphocyte populations, proliferative responses of circulating lymphocytes to mitogens and antigens, and serum concentrations of the major immunoglobulins and complement factor C3. RESULTS: The workers had substantial exposure to substances contaminated with TCDD, as indicated by a lipid adjusted mean serum TCDD concentration of 229 ppt compared with a mean of 6 ppt in the unexposed referents. Workers were divided into categories based on their serum TCDD concentration. For all categories except the lowest, with values of serum TCDD comparable with the unexposed referents, there were increased odds of having lower counts of CD26 cells (activated T cells) (odds ratio (OR) 1.0, 95% confidence interval (95% CI) 0.5 to 1.8 for TCDD < 20 ppt; OR 1.6, 95% CI 0.8 to 3.2 for TCDD 20- 51 ppt; OR 2.7, 95% CI 1.4 to 5.1 for TCDD 52-125 ppt; OR 2.6, 95% CI 1.4 to 4.9 for TCDD 125-297 ppt; OR 2.4, 95% CI 1.3 to 4.6 for TCDD 298- 3389 ppt). A less consistent finding was decreased spontaneous proliferation of cultured lymphocytes. However, increases were found in proliferation of lymphocytes in response to concanavalin and pokeweed in workers in the high TCDD category. Age, cigarette smoking, and alcohol were significant predictors of several immunological outcomes. CONCLUSIONS

  5. Source Mechanism of May 30, 2015 Bonin Islands, Japan Deep Earthquake (Mw7.8) Estimated by Broadband Waveform Modeling

    NASA Astrophysics Data System (ADS)

    Tsuboi, S.; Nakamura, T.; Miyoshi, T.

    2015-12-01

    May 30, 2015 Bonin Islands, Japan earthquake (Mw 7.8, depth 679.9km GCMT) was one of the deepest earthquakes ever recorded. We apply the waveform inversion technique (Kikuchi & Kanamori, 1991) to obtain slip distribution in the source fault of this earthquake in the same manner as our previous work (Nakamura et al., 2010). We use 60 broadband seismograms of IRIS GSN seismic stations with epicentral distance between 30 and 90 degrees. The broadband original data are integrated into ground displacement and band-pass filtered in the frequency band 0.002-1 Hz. We use the velocity structure model IASP91 to calculate the wavefield near source and stations. We assume that the fault is squared with the length 50 km. We obtain source rupture model for both nodal planes with high dip angle (74 degree) and low dip angle (26 degree) and compare the synthetic seismograms with the observations to determine which source rupture model would explain the observations better. We calculate broadband synthetic seismograms with these source propagation models using the spectral-element method (Komatitsch & Tromp, 2001). We use new Earth Simulator system in JAMSTEC to compute synthetic seismograms using the spectral-element method. The simulations are performed on 7,776 processors, which require 1,944 nodes of the Earth Simulator. On this number of nodes, a simulation of 50 minutes of wave propagation accurate at periods of 3.8 seconds and longer requires about 5 hours of CPU time. Comparisons of the synthetic waveforms with the observation at teleseismic stations show that the arrival time of pP wave calculated for depth 679km matches well with the observation, which demonstrates that the earthquake really happened below the 660 km discontinuity. In our present forward simulations, the source rupture model with the low-angle fault dipping is likely to better explain the observations.

  6. Less Time to Study, Less Well Prepared for Work, yet Satisfied with Higher Education: A UK Perspective on Links between Higher Education and the Labour Market

    ERIC Educational Resources Information Center

    Little, Brenda; Arthur, Lore

    2010-01-01

    This paper explores graduates' views on the relationship between higher education and employment. It draws on a major European study involving graduates five years after graduation and highlights similarities and differences between UK graduates' experiences and their European counterparts. Specifically, we address questions raised in the study…

  7. The concentration and distribution of 2,3,7,8-dibenzo-p-dioxins/-furans in chickens

    NASA Technical Reports Server (NTRS)

    Ferrario, J.; Byrne, C.

    2000-01-01

    The concentrations of the 2,3,7,8-Cl substituted dibenzo-p-dioxins/-furans (PCDDs/PCDFs) were determined in the edible tissues of whole chicken fryers and compared with the values found in their abdominal fat. The values are presented both on a whole weight basis and on a lipid adjusted basis for each tissue. While there is a marked difference in the concentration of the 2,3,7,8-dibenzo-p-dioxins in the edible tissues expressed on a whole weight basis, the lipid-adjusted concentrations of the individual dioxins were not statistically different in the various tissues. This validates the use of lipid adjusted concentrations of 2,3,7,8-PCDDs/PCDFs in abdominal fat for the determination of the presence of these compounds in different tissues.

  8. Interception of benzo[a]pyrene-7,8-dione by UDP glucuronosyltransferases (UGTs) in human lung cells.

    PubMed

    Zhang, Li; Huang, Meng; Blair, Ian A; Penning, Trevor M

    2013-10-21

    Polycyclic aromatic hydrocarbons (PAHs) are environmental and tobacco carcinogens. Proximate carcinogenic PAH trans-dihydrodiols are activated by human aldo-keto reductases (AKRs) to yield electrophilic and redox-active o-quinones. Interconversion among benzo[a]pyrene (B[a]P)-7,8-dione, a representative PAH o-quinone, and its corresponding catechol generates a futile redox-cycle with the concomitant production of reactive oxygen species (ROS). We investigated whether glucuronidation of B[a]P-7,8-catechol by human UDP glucuronosyltransferases (UGTs) could intercept the catechol in three different human lung cells. RT-PCR showed that UGT1A1, 1A3, and 2B7 were only expressed in human lung adenocarcinoma A549 cells. The corresponding recombinant UGTs were examined for their kinetic constants and product profile using B[a]P-7,8-catechol as a substrate. B[a]P-7,8-dione was reduced to B[a]P-7,8-catechol by dithiothreitol under anaerobic conditions and then further glucuronidated by the UGTs in the presence of uridine-5'-diphosphoglucuronic acid as a glucuronic acid group donor. UGT1A1 catalyzed the glucuronidation of B[a]P-7,8-catechol and generated two isomeric O-monoglucuronsyl-B[a]P-7,8-catechol products that were identified by RP-HPLC and by LC-MS/MS. By contrast, UGT1A3 and 2B7 catalyzed the formation of only one monoglucuronide, which was identical to that formed in A549 cells. The kinetic profiles of three UGTs followed Michaelis-Menten kinetics. On the basis of the expression levels of UGT1A3 and UGT2B7 and the observation that a single monoglucuronide was produced in A549 cells, we suggest that the major UGT isoforms in A549 cells that can intercept B[a]P-7,8-catechol are UGT1A3 and 2B7.

  9. Shigella IpaH7.8 E3 ubiquitin ligase targets glomulin and activates inflammasomes to demolish macrophages

    PubMed Central

    Suzuki, Shiho; Mimuro, Hitomi; Kim, Minsoo; Ogawa, Michinaga; Ashida, Hiroshi; Toyotome, Takahito; Franchi, Luigi; Suzuki, Masato; Sanada, Takahito; Suzuki, Toshihiko; Tsutsui, Hiroko; Núñez, Gabriel; Sasakawa, Chihiro

    2014-01-01

    When nucleotide-binding oligomerization domain–like receptors (NLRs) sense cytosolic-invading bacteria, they induce the formation of inflammasomes and initiate an innate immune response. In quiescent cells, inflammasome activity is tightly regulated to prevent excess inflammation and cell death. Many bacterial pathogens provoke inflammasome activity and induce inflammatory responses, including cell death, by delivering type III secreted effectors, the rod component flagellin, and toxins. Recent studies indicated that Shigella deploy multiple mechanisms to stimulate NLR inflammasomes through type III secretion during infection. Here, we show that Shigella induces rapid macrophage cell death by delivering the invasion plasmid antigen H7.8 (IpaH7.8) enzyme 3 (E3) ubiquitin ligase effector via the type III secretion system, thereby activating the NLR family pyrin domain-containing 3 (NLRP3) and NLR family CARD domain-containing 4 (NLRC4) inflammasomes and caspase-1 and leading to macrophage cell death in an IpaH7.8 E3 ligase-dependent manner. Mice infected with Shigella possessing IpaH7.8, but not with Shigella possessing an IpaH7.8 E3 ligase-null mutant, exhibited enhanced bacterial multiplication. We defined glomulin/flagellar-associated protein 68 (GLMN) as an IpaH7.8 target involved in IpaH7.8 E3 ligase-dependent inflammasome activation. This protein originally was identified through its association with glomuvenous malformations and more recently was described as a member of a Cullin ring ligase inhibitor. Modifying GLMN levels through overexpression or knockdown led to reduced or augmented inflammasome activation, respectively. Macrophages stimulated with lipopolysaccharide/ATP induced GLMN puncta that localized with the active form of caspase-1. Macrophages from GLMN+/− mice were more responsive to inflammasome activation than those from GLMN+/+ mice. Together, these results highlight a unique bacterial adaptation that hijacks inflammasome activation via

  10. Higher-order time-symmetry-breaking phase transition due to meeting of an exceptional point and a Fano resonance

    NASA Astrophysics Data System (ADS)

    Tanaka, Satoshi; Garmon, Savannah; Kanki, Kazuki; Petrosky, Tomio

    2016-08-01

    We have theoretically investigated the time-symmetry-breaking phase-transition process for two discrete states coupled with a one-dimensional continuum by solving the nonlinear eigenvalue problem for the effective Hamiltonian associated with the discrete spectrum. We obtain the effective Hamiltonian with use of the Feshbach-Brillouin-Wigner projection method. Strong energy dependence of the self-energy appearing in the effective Hamiltonian plays a key role in the time-symmetry-breaking phase transition: As a result of competition in the decay process between the Van Hove singularity and the Fano resonance, the phase transition becomes a higher-order transition when both the two discrete states are located near the continuum threshold.

  11. Higher level phylogeny and the first divergence time estimation of Heteroptera (Insecta: Hemiptera) based on multiple genes.

    PubMed

    Li, Min; Tian, Ying; Zhao, Ying; Bu, Wenjun

    2012-01-01

    Heteroptera, or true bugs, are the largest, morphologically diverse and economically important group of insects with incomplete metamorphosis. However, the phylogenetic relationships within Heteroptera are still in dispute and most of the previous studies were based on morphological characters or with single gene (partial or whole 18S rDNA). Besides, so far, divergence time estimates for Heteroptera totally rely on the fossil record, while no studies have been performed on molecular divergence rates. Here, for the first time, we used maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference (BI) with multiple genes (18S rDNA, 28S rDNA, 16S rDNA and COI) to estimate phylogenetic relationships among the infraorders, and meanwhile, the Penalized Likelihood (r8s) and Bayesian (BEAST) molecular dating methods were employed to estimate divergence time of higher taxa of this suborder. Major results of the present study included: Nepomorpha was placed as the most basal clade in all six trees (MP trees, ML trees and Bayesian trees of nuclear gene data and four-gene combined data, respectively) with full support values. The sister-group relationship of Cimicomorpha and Pentatomomorpha was also strongly supported. Nepomorpha originated in early Triassic and the other six infraorders originated in a very short period of time in middle Triassic. Cimicomorpha and Pentatomomorpha underwent a radiation at family level in Cretaceous, paralleling the proliferation of the flowering plants. Our results indicated that the higher-group radiations within hemimetabolous Heteroptera were simultaneously with those of holometabolous Coleoptera and Diptera which took place in the Triassic. While the aquatic habitat was colonized by Nepomorpha already in the Triassic, the Gerromorpha independently adapted to the semi-aquatic habitat in the Early Jurassic.

  12. Higher Level Phylogeny and the First Divergence Time Estimation of Heteroptera (Insecta: Hemiptera) Based on Multiple Genes

    PubMed Central

    Zhao, Ying; Bu, Wenjun

    2012-01-01

    Heteroptera, or true bugs, are the largest, morphologically diverse and economically important group of insects with incomplete metamorphosis. However, the phylogenetic relationships within Heteroptera are still in dispute and most of the previous studies were based on morphological characters or with single gene (partial or whole 18S rDNA). Besides, so far, divergence time estimates for Heteroptera totally rely on the fossil record, while no studies have been performed on molecular divergence rates. Here, for the first time, we used maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference (BI) with multiple genes (18S rDNA, 28S rDNA, 16S rDNA and COI) to estimate phylogenetic relationships among the infraorders, and meanwhile, the Penalized Likelihood (r8s) and Bayesian (BEAST) molecular dating methods were employed to estimate divergence time of higher taxa of this suborder. Major results of the present study included: Nepomorpha was placed as the most basal clade in all six trees (MP trees, ML trees and Bayesian trees of nuclear gene data and four-gene combined data, respectively) with full support values. The sister-group relationship of Cimicomorpha and Pentatomomorpha was also strongly supported. Nepomorpha originated in early Triassic and the other six infraorders originated in a very short period of time in middle Triassic. Cimicomorpha and Pentatomomorpha underwent a radiation at family level in Cretaceous, paralleling the proliferation of the flowering plants. Our results indicated that the higher-group radiations within hemimetabolous Heteroptera were simultaneously with those of holometabolous Coleoptera and Diptera which took place in the Triassic. While the aquatic habitat was colonized by Nepomorpha already in the Triassic, the Gerromorpha independently adapted to the semi-aquatic habitat in the Early Jurassic. PMID:22384163

  13. Higher level phylogeny and the first divergence time estimation of Heteroptera (Insecta: Hemiptera) based on multiple genes.

    PubMed

    Li, Min; Tian, Ying; Zhao, Ying; Bu, Wenjun

    2012-01-01

    Heteroptera, or true bugs, are the largest, morphologically diverse and economically important group of insects with incomplete metamorphosis. However, the phylogenetic relationships within Heteroptera are still in dispute and most of the previous studies were based on morphological characters or with single gene (partial or whole 18S rDNA). Besides, so far, divergence time estimates for Heteroptera totally rely on the fossil record, while no studies have been performed on molecular divergence rates. Here, for the first time, we used maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference (BI) with multiple genes (18S rDNA, 28S rDNA, 16S rDNA and COI) to estimate phylogenetic relationships among the infraorders, and meanwhile, the Penalized Likelihood (r8s) and Bayesian (BEAST) molecular dating methods were employed to estimate divergence time of higher taxa of this suborder. Major results of the present study included: Nepomorpha was placed as the most basal clade in all six trees (MP trees, ML trees and Bayesian trees of nuclear gene data and four-gene combined data, respectively) with full support values. The sister-group relationship of Cimicomorpha and Pentatomomorpha was also strongly supported. Nepomorpha originated in early Triassic and the other six infraorders originated in a very short period of time in middle Triassic. Cimicomorpha and Pentatomomorpha underwent a radiation at family level in Cretaceous, paralleling the proliferation of the flowering plants. Our results indicated that the higher-group radiations within hemimetabolous Heteroptera were simultaneously with those of holometabolous Coleoptera and Diptera which took place in the Triassic. While the aquatic habitat was colonized by Nepomorpha already in the Triassic, the Gerromorpha independently adapted to the semi-aquatic habitat in the Early Jurassic. PMID:22384163

  14. Neutron structure of human carbonic anhydrase II: A hydrogen bonded water network switch is observed between pH 7.8 and 10.0.

    SciTech Connect

    Fisher, Zoe; Langan, Paul; Mustyakimov, Marat; Kovalevsky, Andrey

    2011-01-01

    The neutron structure of wild type human carbonic anhydrase II at pH 7.8 has been determined to 2.0 resolution. Detailed analysis and comparison to the previous determined structure at pH 10.0 shows important differences in protonation of key catalytic residues in the active site as well as a rearrangement of the hydrogen bonded water network. For the first time, a completed hydrogen bonded network stretching from the Zn-bound solvent to the proton shuttling residue His64 has been directed observed.

  15. Hepatic metabolism of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the rat and guinea pig

    SciTech Connect

    Wroblewski, V.J.; Olson, J.R.

    1985-11-01

    Marked interspecies variability exists in the acute toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), with the rat having an LD/sub 50/ about 25-fold greater than the guinea pig. The metabolism of TCDD was examined by incubating hepatocytes isolated from these animals with purified (/sup 14/C)TCDD (2.2 microM) for 8 hr. Over the 8-hr incubation, cytochrome P-450 content and ethoxyresorufin O-deethylase and benzphetamine N-demethylase activities were well maintained, indicating the functional viability of the hepatocytes. Quantitative differences were observed in the rate of (/sup 14/C)TCDD metabolism, with hepatocytes from control rats metabolizing TCDD at a rate 2.8-fold greater than hepatocytes from control guinea pigs. The role of the hepatic cytochrome P-450-448-dependent monooxygenase system in the metabolism of TCDD was examined through the use of hepatocytes isolated from animals pretreated with either TCDD or phenobarbital. The rate of (/sup 14/C)TCDD metabolite formation in hepatocytes from TCDD pretreated guinea pigs (0.26 +/- 0.14 pmol mg cell protein-1 hr-1) was unchanged from the control rate, while the rate in hepatocytes from TCDD pretreated rats was 3.2-fold greater than control and nine times greater than in hepatocytes from TCDD-pretreated guinea pigs. On the other hand, phenobarbital pretreatment produced little change in the rate of (/sup 14/C)TCDD metabolism in rat hepatocytes. These results suggest that TCDD may be metabolized by a TCDD inducible form of cytochrome P-448 which is expressed in the rat but not in the guinea pig.

  16. Inter-strain heterogeneity in rat hepatic transcriptomic responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

    SciTech Connect

    Yao, Cindy Q.; Prokopec, Stephenie D.; Watson, John D.; Pang, Renee; P'ng, Christine; Chong, Lauren C.; Harding, Nicholas J.; Pohjanvirta, Raimo; Okey, Allan B.; Boutros, Paul C.

    2012-04-15

    The biochemical and toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) have been the subject of intense study for decades. It is now clear that essentially all TCDD-induced toxicities are mediated by DNA–protein interactions involving the Aryl Hydrocarbon Receptor (AHR). Nevertheless, it remains unknown which AHR target genes cause TCDD toxicities. Several groups, including our own, have developed rodent model systems to probe these questions. mRNA expression profiling of these model systems has revealed significant inter-species heterogeneity in rodent hepatic responses to TCDD. It has remained unclear if this variability also exists within a species, amongst rodent strains. To resolve this question, we profiled the hepatic transcriptomic response to TCDD of diverse rat strains (L-E, H/W, F344 and Wistar rats) and two lines derived from L-E × H/W crosses, at consistent age, sex, and dosing (100 μg/kg TCDD for 19 h). Using this uniquely consistent dataset, we show that the majority of TCDD-induced alterations in mRNA abundance are strain/line-specific: only 11 genes were affected by TCDD across all strains, including well-known dioxin-responsive genes such as Cyp1a1 and Nqo1. Our analysis identified two novel universally dioxin-responsive genes as well as 4 genes induced by TCDD in dioxin-sensitive rats only. These 6 genes are strong candidates to explain TCDD-related toxicities, so we validated them using 152 animals in time-course (0 to 384 h) and dose–response (0 to 3000 μg/kg) experiments. This study reveals that different rat strains exhibit dramatic transcriptional heterogeneity in their hepatic responses to TCDD and that inter-strain comparisons can help identify candidate toxicity-related genes.

  17. Species differences in 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity and biotransformation in fish

    SciTech Connect

    Kleeman, J.M.; Olson, J.R.; Peterson, R.E.

    1988-02-01

    Rainbow trout, yellow perch, carp, bluegill, largemouth bass, and bullhead were treated with graded doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 1, 5, 25, or 125 micrograms/kg) or vehicle, ip. The lethal potency of TCDD tended to be greater in yellow perch, carp, and bullhead than in the other three species (LD50 80 days post-treatment, 3-5 versus 10-16 micrograms/kg, respectively). All species treated with the highest dose of TCDD (125 micrograms/kg) displayed a latency period of 1-4 weeks prior to death; longer latency periods were produced by lower lethal doses. Effects of TCDD treatment on body weight were both species-dependent and dose-dependent. Fin necrosis was observed in all fish species; however, cutaneous hemorrhage was observed only in TCDD-treated perch, carp, and bluegill, and cutaneous hyperpigmentation only in TCDD-treated carp and largemouth bass. Gallbladder bile was analyzed for TCDD and its metabolites 7 days after fish were injected with (/sup 14/C)TCDD (60 micrograms/kg, ip). At least three TCDD metabolites in addition to the parent compound were found in the gallbladder bile of all six species. In addition, the retention time of the major biliary TCDD metabolite (determined by HPLC) was similar in all species except yellow perch. Beta-Glucuronidase treatment of the bile from largemouth bass and bluegill suggested that at least two of the TCDD metabolites were glucuronide conjugates. Thus, species differences exist in the lethal potency, signs of overt toxicity, and biotransformation of TCDD among freshwater fish.

  18. Oxidative stress in female B6C3F1 mice following acute and subchronic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

    PubMed

    Slezak, B P; Hatch, G E; DeVito, M J; Diliberto, J J; Slade, R; Crissman, K; Hassoun, E; Birnbaum, L S

    2000-04-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a highly persistent trace environmental contaminant and is one of the most potent toxicants known to man. Hassoun et al. (1998, Toxicol. Sci. 42, 23-27) reported an increase in the production of reactive oxygen species (ROS) in the brain of female B6C3F1 mice following subchronic exposure to TCDD at doses as low as 0.45 ng/kg/day. In the present study, oxidative stress was characterized in liver, spleen, lung, and kidney following subchronic (0.15-150 ng/kg; 5 days/week for 13 weeks, po) or acute exposure (0.001-100 microg/kg, po) to TCDD in order to investigate the interaction between tissue concentration and time for production of ROS. Seven days following acute administration of TCDD, mice were sacrificed; they demonstrated increases in liver superoxide anion production (SOAP) and thiobarbituric acid reactive substances (TBARS) at doses of 10 and 100 microg/kg, associated with hepatic TCDD concentrations of 55 and 321 ng/g, respectively. Liver obtained from mice following subchronic TCDD exposure demonstrated an increase in SOAP and TBARS above controls at doses of 150 ng/kg/day with liver TCDD concentration of only 12 ng/g. Interestingly, glutathione (GSH) levels in lung and kidney following sub-chronic TCDD exposure were decreased at the low dose of 0.15 ng/kg/day. This effect disappeared at higher TCDD doses. The data suggest that higher tissue TCDD concentrations are required to elicit oxidative stress following acute dosing than with subchronic TCDD exposure. Therefore, the mechanism of ROS production following TCDD exposure does not appear to be solely dependent upon the concentration of TCDD within the tissue. In addition, very low doses of TCDD that result in tissue concentrations similar to the background levels found in the human population produced an effect on an oxidative stress endogenous defense system. The role of this effect in TCDD-mediated toxicity is not known and warrants further investigation.

  19. COMPARATIVE SENSITIVITY OF DIFFERENT LIFE-STAGES OF MEDAKA AND SALMONID FISHES TO 2,3,7,8-TCDD

    EPA Science Inventory

    The early life stages of fish are known to be more sensitive than the adults to the toxicological effects of 2,3,7,8-tetrachlorodibenzo(p)dioxin (TCDD). Embryo larval stages of medake, for example, experience 50% lethality when TCDD residues in the eggs are 1396 pg/g. By contrast...

  20. 40 CFR 180.1283 - (Z)-7,8-epoxy-2-methyloctadecane (Disparlure); exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false (Z)-7,8-epoxy-2-methyloctadecane (Disparlure); exemption from the requirement of a tolerance. 180.1283 Section 180.1283 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD...

  1. Percutaneous Absorption of 2,3,7,8-Tetrachlorodibenzo-P-Dioxin (TCDD) From Soil (Journal Article)

    EPA Science Inventory

    Eight dermal absorption (two in vivo; six in vitro) and one intravenous experiment were conducted using 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) either neat (high dose at ~250 µg/cm2 and low dose at 10 ng/cm2) or sorbed on a low organic (LOS) or high organic (HOS) soil at 1 ppm...

  2. TERATOGENIC RESPONSES OF TGFALPHA KNOCKOUT FETUSES TO 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD)

    EPA Science Inventory

    ABBOTT1, B.D., A.R. BUCKALEW1, and P.L. BRYANT2. 1Reproductive Toxicology Division, EPA, RAP, NC; 2Dept. Environ. Sciences & Engineering, UNC, Chapel Hill, NC. Teratogenic responses of TGF knockout fetuses to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

    TCDD induces cl...

  3. CYP1A2 IS NOT REQUIRED FOR 2, 3, 7, 8-TETRACHLORODIBENZO-P-DIOXIN-INDUCED IMMUNOSUPPRESSION

    EPA Science Inventory

    ABSTRACT
    One of the most sensitive and reproducible immunotoxic endpoints of 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) exposure is suppression of the antibody response to sheep red blood cells (SRBCs) in mice. Immunosuppression occurs in concert with hepatomegaly and associ...

  4. FORMATION OF 8-OXO-7, 8-DIHYDRO-2'-DEOXYGUANOSINE IN RAT LUNG FOLLOWING SUB-CHRONIC INHALATION OF CARBON BLACK

    EPA Science Inventory

    ABSTRACT
    Formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine, an oxidative adduct in the lung DNA of rats following sub-chronic inhalation of carbon black. Gallagher, J., Sams II, R.L., Inmon, J., Gelein, R., Elder, A., Oberdorster, G., Prahalad, A. (2002). Toxicol. Appl. Pharm...

  5. THE CONCENTRATION AND DISTRIBUTION OF 2,3,7,8-DIBENZO-P-DIOXINS / - FURANS IN CHICKENS

    EPA Science Inventory

    The concentrations of 2,3,7,8-Cl substituted dibenzo-p-dioxins/-furans (PCDDs/PCDFs) were determined in the edible tissues of whole chicken fryers and compared with the values found in their abdominal fat. The values are presented both on a whole weight basis and on a lipid-adju...

  6. Detoxication of benzo[a]pyrene-7,8-dione by sulfotransferases (SULTs) in human lung cells.

    PubMed

    Zhang, Li; Huang, Meng; Blair, Ian A; Penning, Trevor M

    2012-08-24

    Polycyclic aromatic hydrocarbons (PAH) are environmental and tobacco carcinogens. Human aldo-keto reductases catalyze the metabolic activation of proximate carcinogenic PAH trans-dihydrodiols to yield electrophilic and redox-active o-quinones. Benzo[a]pyrene-7,8-dione a representative PAH o-quinone is reduced back to the corresponding catechol to generate a futile redox-cycle. We investigated whether sulfonation of PAH catechols by human sulfotransferases (SULT) could intercept the catechol in human lung cells. RT-PCR identified SULT1A1, -1A3, and -1E1 as the isozymes expressed in four human lung cell lines. The corresponding recombinant SULTs were examined for their substrate specificity. Benzo[a]pyrene-7,8-dione was reduced to benzo[a]pyrene-7,8-catechol by dithiothreitol under anaerobic conditions and then further sulfonated by the SULTs in the presence of 3'-[(35)S]phosphoadenosine 5'-phosphosulfate as the sulfonate group donor. The human SULTs catalyzed the sulfonation of benzo[a]pyrene-7,8-catechol and generated two isomeric benzo[a]pyrene-7,8-catechol O-monosulfate products that were identified by reversed phase HPLC and by LC-MS/MS. The various SULT isoforms produced the two isomers in different proportions. Two-dimensional (1)H and (13)C NMR assigned the two regioisomers of benzo[a]pyrene-7,8-catechol monosulfate as 8-hydroxy-benzo[a]pyrene-7-O-sulfate (M1) and 7-hydroxy-benzo[a]pyrene-8-O-sulfate (M2), respectively. The kinetic profiles of three SULTs were different. SULT1A1 gave the highest catalytic efficiency (k(cat)/K(m)) and yielded a single isomeric product corresponding to M1. By contrast, SULT1E1 showed distinct substrate inhibition and formed both M1 and M2. Based on expression levels, catalytic efficiency, and the fact that the lung cells only produce M1, it is concluded that the major isoform that can intercept benzo[a]pyrene-7,8-catechol is SULT1A1.

  7. Introducing conjoint analysis method into delayed lotteries studies: its validity and time stability are higher than in adjusting

    PubMed Central

    Białek, Michał; Markiewicz, Łukasz; Sawicki, Przemysław

    2015-01-01

    The delayed lotteries are much more common in everyday life than are pure lotteries. Usually, we need to wait to find out the outcome of the risky decision (e.g., investing in a stock market, engaging in a relationship). However, most research has studied the time discounting and probability discounting in isolation using the methodologies designed specifically to track changes in one parameter. Most commonly used method is adjusting, but its reported validity and time stability in research on discounting are suboptimal. The goal of this study was to introduce the novel method for analyzing delayed lotteries—conjoint analysis—which hypothetically is more suitable for analyzing individual preferences in this area. A set of two studies compared the conjoint analysis with adjusting. The results suggest that individual parameters of discounting strength estimated with conjoint have higher predictive value (Study 1 and 2), and they are more stable over time (Study 2) compared to adjusting. We discuss these findings, despite the exploratory character of reported studies, by suggesting that future research on delayed lotteries should be cross-validated using both methods. PMID:25674069

  8. Genotoxicity of styrene-7,8-oxide and styrene in Fisher 344 rats: a 4-week inhalation study.

    PubMed

    Gaté, Laurent; Micillino, Jean-Claude; Sébillaud, Sylvie; Langlais, Cristina; Cosnier, Frédéric; Nunge, Hervé; Darne, Christian; Guichard, Yves; Binet, Stéphane

    2012-06-20

    The cytogenetic alterations in leukocytes and the increased risk for leukemia, lymphoma, or all lymphohematopoietic cancer observed in workers occupationally exposed to styrene have been associated with its hepatic metabolisation into styrene-7,8-oxide, an epoxide which can induce DNA damages. However, it has been observed that styrene-7,8-oxide was also found in the atmosphere of reinforced plastic industries where large amounts of styrene are used. Since the main route of exposure to these compounds is inhalation, in order to gain new insights regarding their systemic genotoxicity, Fisher 344 male rats were exposed in full-body inhalation chambers, 6 h/day, 5 days/week for 4 weeks to styrene-7,8-oxide (25, 50, and 75 ppm) or styrene (75, 300, and 1000 ppm). Then, the induction of micronuclei in circulating reticulocytes and DNA strand breaks in leukocytes using the comet assay was studied at the end of the 3rd and 20th days of exposure. Our results showed that neither styrene nor styrene-7,8-oxide induced a significant increase of the micronucleus frequency in reticulocytes or DNA strand breaks in white blood cells. However, in the presence of the formamidopyridine DNA glycosylase, an enzyme able to recognize and excise DNA at the level of some oxidized DNA bases, a significant increase of DNA damages was observed at the end of the 3rd day of treatment in leukocytes from rats exposed to styrene but not to styrene-7,8-oxide. This experimental design helped to gather new information regarding the systemic genotoxicity of these two chemicals and may be valuable for the risk assessment associated with an occupational exposure to these molecules.

  9. Invitational Conference on College Prepayment and Savings Plans (Denver, Colorado, June 7-8, 1987). Summary.

    ERIC Educational Resources Information Center

    College Entrance Examination Board, New York, NY.

    Summaries of conference presentations on college savings and prepayment plans and related tax, policy, and social issues are provided. The conference objective was to communicate the issues to constituents with the most at stake: parents, students, and relatives; state and federal legislators and staff; and developers of plans for higher education…

  10. Quantum reaction rate from higher derivatives of the thermal flux-flux autocorrelation function at time zero.

    PubMed

    Ceotto, Michele; Yang, Sandy; Miller, William H

    2005-01-22

    A quantum theory of thermal reaction rates is presented which may be viewed as an extension of the recently developed "quantum instanton" (QI) model [W. H. Miller, Y. Zhao, M. Ceotto, and S. Yang, J. Chem. Phys. 119, 1329 (2003)]. It is based on using higher derivatives of the flux-flux autocorrelation function C(t) (as given by Miller, Schwartz, and Tromp) at t=0 to construct a short time approximation for C(t). Tests of this theory on 1d and collinear reactions, both symmetric and asymmetric, show it to be more accurate than the original QI model, giving rate constants to approximately 5% for a wide range of temperature. PMID:15740237

  11. Quantum reaction rate from higher derivatives of the thermal flux-flux autocorrelation function at time zero

    NASA Astrophysics Data System (ADS)

    Ceotto, Michele; Yang, Sandy; Miller, William H.

    2005-01-01

    A quantum theory of thermal reaction rates is presented which may be viewed as an extension of the recently developed "quantum instanton" (QI) model [W. H. Miller, Y. Zhao, M. Ceotto, and S. Yang, J. Chem. Phys. 119, 1329 (2003)]. It is based on using higher derivatives of the flux-flux autocorrelation function C(t) (as given by Miller, Schwartz, and Tromp) at t=0 to construct a short time approximation for C(t). Tests of this theory on 1d and collinear reactions, both symmetric and asymmetric, show it to be more accurate than the original QI model, giving rate constants to ˜5% for a wide range of temperature.

  12. Time in Bed is Associated with Decreased Physical Activity and Higher BMI in Women Seeking Weight Loss Treatment.

    PubMed

    Hart, Chantelle N; Fava, Joseph L; Subak, Leslee L; Stone, Katie; Vittinghoff, Eric; Demos, Kathryn; O'Brien, Erin; Cairns, Alyssa; Wing, Rena

    2012-01-01

    Short sleep duration is associated with obesity risk. Despite calls to incorporate strategies to enhance sleep within the context of behavioral weight loss (BWL) treatment, little is known regarding the association between sleep and body mass index (BMI) among individuals presenting for BWL. Moreover, most research has focused on eating pathways linking sleep and BMI, and have not explored how sleep may impact engagement in physical activity. The purpose of the present study was to determine whether, in a sample of women seeking treatment for weight loss, there was an association between reported time in bed (TIB), higher BMI, lower physical activity, and less favorable dietary composition. Prior to randomization, 318 women completed measures of TIB, eating, and activity; weight and height were measured. Findings demonstrated that report of '6 hours or less' TIB/night was associated with higher BMI and lower reported physical activity compared to the referent (>7 to ≤ 8 hours/night). It was not associated with the number of reported calories consumed each day or with the percent of calories consumed from fat, carbohydrates or protein. Better understanding the role of sleep within the context of BWL treatment in women seems warranted.

  13. Structure-based design and development of functionalized Mercaptoguanine derivatives as inhibitors of the folate biosynthesis pathway enzyme 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase from Staphylococcus aureus.

    PubMed

    Dennis, Matthew L; Chhabra, Sandeep; Wang, Zhong-Chang; Debono, Aaron; Dolezal, Olan; Newman, Janet; Pitcher, Noel P; Rahmani, Raphael; Cleary, Ben; Barlow, Nicholas; Hattarki, Meghan; Graham, Bim; Peat, Thomas S; Baell, Jonathan B; Swarbrick, James D

    2014-11-26

    6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK), an enzyme from the folate biosynthesis pathway, catalyzes the pyrophosphoryl transfer from ATP to 6-hydroxymethyl-7,8-dihydropterin and is a yet-to-be-drugged antimicrobial target. Building on our previous discovery that 8-mercaptoguanine (8MG) is an inhibitor of Staphylococcus aureus HPPK (SaHPPK), we have identified and characterized the binding of an S8-functionalized derivative (3). X-ray structures of both the SaHPPK/3/cofactor analogue ternary and the SaHPPK/cofactor analogue binary complexes have provided insight into cofactor recognition and key residues that move over 30 Å upon binding of 3, whereas NMR measurements reveal a partially plastic ternary complex active site. Synthesis and binding analysis of a set of analogues of 3 have identified an advanced new lead compound (11) displaying >20-fold higher affinity for SaHPPK than 8MG. A number of these exhibited low micromolar affinity for dihydropteroate synthase (DHPS), the adjacent, downstream enzyme to HPPK, and may thus represent promising new leads to bienzyme inhibitors. PMID:25357262

  14. Exocrine pancreatic pathology in female Harlan Sprague-Dawley rats after chronic treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin and dioxin-like compounds.

    PubMed Central

    Nyska, Abraham; Jokinen, Micheal P; Brix, Amy E; Sells, Donald M; Wyde, Michael E; Orzech, Denise; Haseman, Joseph K; Flake, Gordon; Walker, Nigel J

    2004-01-01

    We evaluated the effect of chronic exposure to dioxin and dioxin-like compounds on the pancreas in female Harlan Sprague-Dawley rats. This investigation represents part of an ongoing National Toxicology Program initiative to determine the relative potency of chronic toxicity and carcinogenicity of polychlorinated dioxins, furans, and biphenyls. Animals were treated by gavage for up to 2 years with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3,4,4,5-pentachlorobiphenyl (PCB-126), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), or a toxic-equivalency-factor (TEF) mixture of these agents; control animals received corn oil-acetone vehicle alone. A complete necropsy was performed on all animals, and a full complement of tissues was collected and examined microscopically. Administration of each of the four compounds was associated with increased incidences of several nonneoplastic changes in the exocrine pancreas, including cytoplasmic vacuolation, chronic active inflammation, atrophy, and arteritis. Low incidences, but higher than those in the historical database, of pancreatic acinar adenoma and carcinoma were seen in the TCDD, PeCDF, and TEF-mixture groups. These results indicate that the pancreatic acini are target tissues for dioxin and certain dioxin-like compounds. Key words: carcinogenesis, dioxin, furans, inflammation, pancreas, polychlorinated biphenyls. PMID:15175180

  15. Floods of August 7-8, 1979, in Chautauqua County, New York, with hydraulic analysis of Canadaway Creek in the village of Fredonia

    USGS Publications Warehouse

    Lumia, Richard; Johnston, W.H.

    1984-01-01

    Extensive flooding of streams in Chautauqua County, N.Y., on August 7-8, 1979, after severe thunderstorms, resulted in one death and millions of dollars worth of property damage. Severe flooding was reported on Canadaway Creek in Fredonia, where the peak discharge was computed to be 12,000 cubic feet per second. The recurrence interval of this discharge is estimated to be greater than 100 years (exceedance probability less than 0.01). A hydraulic analysis of the flood in Fredonia indicated that a debris jam at the Water Street bridge caused the water level (as determined from floodmarks) immediately upstream from the bridge to be 2.9 feet higher than level computed for unobstructed (without debris) flow conditions. The 100-year flood discharge at the Water Street bridge is computed to be 5,280 cubic feet per second, and the corresponding water level just upstream from the bridge (under unobstructed flow conditions) is 5.9 feet lower than the level observed during the August 7-8, 1979 flood. (USGS)

  16. Energy-momentum conserving higher-order time integration of nonlinear dynamics of finite elastic fiber-reinforced continua

    NASA Astrophysics Data System (ADS)

    Erler, Norbert; Groß, Michael

    2015-05-01

    Since many years the relevance of fibre-reinforced polymers is steadily increasing in fields of engineering, especially in aircraft and automotive industry. Due to the high strength in fibre direction, but the possibility of lightweight construction, these composites replace more and more traditional materials as metals. Fibre-reinforced polymers are often manufactured from glass or carbon fibres as attachment parts or from steel or nylon cord as force transmission parts. Attachment parts are mostly subjected to small strains, but force transmission parts usually suffer large deformations in at least one direction. Here, a geometrically nonlinear formulation is necessary. Typical examples are helicopter rotor blades, where the fibres have the function to stabilize the structure in order to counteract large centrifugal forces. For long-run analyses of rotor blade deformations, we have to apply numerically stable time integrators for anisotropic materials. This paper presents higher-order accurate and numerically stable time stepping schemes for nonlinear elastic fibre-reinforced continua with anisotropic stress behaviour.

  17. Pattern formations in miscellaneous mixtures of Bose-Einstein condensates and the higher-dimensional time-gated Manakov system

    SciTech Connect

    Kuetche, Victor K.; Bouetou, Thomas B.; Kofane, Timoleon C.; Moubissi, Alain B.; Porsezian, K.

    2010-11-15

    In this article, we investigate the structure and dynamics of miscellaneous mixtures of Bose-Einstein condensates confined within a time-independent anisotropic parabolic trap potential. In the zero-temperature mean-field approximation leading to coupled Gross-Pitaevskii equations for the macroscopic wave functions of the condensates, we show that these equations can be mapped onto the higher-dimensional time-gated Manakov system up to a first-order of accuracy. Paying particular attention to two-species mixtures and looking forward deriving a panel of miscellaneous excitations to the above equations, we analyze the singularity structure of the system by means of Weiss et al.'s [J. Weiss, M. Tabor, and G. Carnevale, J. Math. Phys. 24, 522 (1983); 25, 13 (1984).] methodology and provide its general Lax representation. As a result, we unearth a typical spectrum of localized and periodic coherent patterns while depicting elastic and nonelastic interactions among such structures alongside the splitting and resonance phenomena occurring during their motion.

  18. Information transfer across the scales of climate variability: The effect of the 7-8 year cycle on the annual and interannual scales

    NASA Astrophysics Data System (ADS)

    Palus, Milan; Jajcay, Nikola; Hlinka, Jaroslav; Kravtsov, Sergey; Tsonis, Anastasios

    2016-04-01

    Complexity of the climate system stems not only from the fact that it is variable over a huge range of spatial and temporal scales, but also from the nonlinear character of the climate system that leads to interactions of dynamics across scales. The dynamical processes on large time scales influence variability on shorter time scales. This nonlinear phenomenon of cross-scale causal interactions can be observed due to the recently introduced methodology [1] which starts with a wavelet decomposition of a multi-scale signal into quasi-oscillatory modes of a limited bandwidth, described using their instantaneous phases and amplitudes. Then their statistical associations are tested in order to search for interactions across time scales. An information-theoretic formulation of the generalized, nonlinear Granger causality [2] uncovers causal influence and information transfer from large-scale modes of climate variability with characteristic time scales from years to almost a decade to regional temperature variability on short time scales. In analyses of air temperature records from various European locations, a quasioscillatory phenomenon with the period around 7-8 years has been identified as the factor influencing variability of surface air temperature (SAT) on shorter time scales. Its influence on the amplitude of the SAT annual cycle was estimated in the range 0.7-1.4 °C and the effect on the overall variability of the SAT anomalies (SATA) leads to the changes 1.5-1.7 °C in the annual SATA means. The strongest effect of the 7-8 year cycle was observed in the winter SATA means where it reaches 4-5 °C in central European station and reanalysis data [3]. This study is supported by the Ministry of Education, Youth and Sports of the Czech Republic within the Program KONTAKT II, Project No. LH14001. [1] M. Palus, Phys. Rev. Lett. 112 078702 (2014) [2] M. Palus, M. Vejmelka, Phys. Rev. E 75, 056211 (2007) [3] N. Jajcay, J. Hlinka, S. Kravtsov, A. A. Tsonis, M. Palus, Time

  19. Vibrational and electronic spectra of 9,10-dihydrobenzo(a)pyren-7(8H)-one and 7,8,9,10-tetrahydrobenzo(a)pyrene: An experimental and computational study

    NASA Astrophysics Data System (ADS)

    Onchoke, Kefa K.; Dutta, Prabir K.; Parks, Matthew E.; Martinez, Mireya N.

    2011-10-01

    The molecular geometries, vibrational and UV-vis spectra of 9,10-dihydrobenzo(a)pyrene-7(8H)-one (9,10-H 2BaP) and 7,8,9,10-tetrahydrobenzo(a)pyrene (7,8,9,10-H 4BaP) were investigated using density functional theory (DFT-B3LYP), with the triple-ζ 6-311 + G(d,p) and Dunning's cc-pVTZ basis sets. From the comparison of infrared experimental and calculated infrared, and Raman data comprehensive assignments are made. The calculated infrared frequencies below 1800 cm -1 are in good agreement with experimental data, with an average deviation of <4 cm -1. Using the B3LYP/6-311 + G(d,p)//TD-B3LYP/6-311G(d,p) level of theory, transition energies, and oscillator strengths of the 30 lowest electronic absorption bands are assigned to π-π* transitions, with good qualitative agreement between experimental and simulated absorption data. In addition, the HOMO-LUMO gaps and their chemical hardness were analyzed.

  20. A novel Fast Gas Chromatography based technique for higher time resolution measurements of speciated monoterpenes in air

    NASA Astrophysics Data System (ADS)

    Jones, C. E.; Kato, S.; Nakashima, Y.; Kajii, Y.

    2013-12-01

    Biogenic emissions supply the largest fraction of non-methane volatile organic compounds (VOC) from the biosphere to the atmospheric boundary layer, and typically comprise a complex mixture of reactive terpenes. Due to this chemical complexity, achieving comprehensive measurements of biogenic VOC (BVOC) in air within a satisfactory time resolution is analytically challenging. To address this, we have developed a novel, fully automated Fast Gas Chromatography (Fast-GC) based technique to provide higher time resolution monitoring of monoterpenes (and selected other C9-C15 terpenes) during plant emission studies and in ambient air. To our knowledge, this is the first study to apply a Fast-GC based separation technique to achieve quantification of terpenes in air. Three chromatography methods have been developed for atmospheric terpene analysis under different sampling scenarios. Each method facilitates chromatographic separation of selected BVOC within a significantly reduced analysis time compared to conventional GC methods, whilst maintaining the ability to quantify individual monoterpene structural isomers. Using this approach, the C10-C15 BVOC composition of single plant emissions may be characterised within a ~ 14 min analysis time. Moreover, in situ quantification of 12 monoterpenes in unpolluted ambient air may be achieved within an ~ 11 min chromatographic separation time (increasing to ~ 19 min when simultaneous quantification of multiple oxygenated C9-C10 terpenoids is required, and/or when concentrations of anthropogenic VOC are significant). This corresponds to a two- to fivefold increase in measurement frequency compared to conventional GC methods. Here we outline the technical details and analytical capability of this chromatographic approach, and present the first in situ Fast-GC observations of 6 monoterpenes and the oxygenated BVOC linalool in ambient air. During this field deployment within a suburban forest ~ 30 km west of central Tokyo, Japan, the

  1. Differential toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in C57BL/6J mice congenic at the Ah Locus.

    PubMed

    Birnbaum, L S; McDonald, M M; Blair, P C; Clark, A M; Harris, M W

    1990-07-01

    The acute toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was examined in male C57BL/6J mice differing only at the Ah locus. Wild type mice (Ahb/b, "b/b") were treated once with 0, 50, 100, 200, 300, and 400 micrograms TCDD/kg po while congenic mice (Ahd/d, "d/d") received a single dose of 0, 400, 800, 1600, 2400, and 3200 micrograms TCDD/kg. Mice were checked daily, weighed twice a week, and those that survived, killed 35 days post-treatment. The LD50 values were 159 and 3351 micrograms/kg for b/b and d/d mice, respectively. Mean time to death was 22 days and was independent of dose and genotype. Decrease in body weight gain was noted in both strains 5 days after treatment and occurred at doses greater than or equal to 100 micrograms/kg in b/b mice and 1600 micrograms/kg in d/d mice. Dose-related increases in liver weight (both absolute and relative to body weight) and decreases in thymus, spleen, testes, and epididymal fat pad weights were observed at 8-24-fold higher doses in d/d than in b/b mice. A dose-related increase in segmented neutrophils was observed in both strains. Serum chemistry values indicated that 8-24X greater doses of TCDD were needed to elevate sorbitol dehydrogenase, alanine aminotransferase, and 5'-nucleotidase and to decrease total and esterified cholesterol in d/d than in b/b mice. Few effects were seen on total bile acids, serum triglycerides, glucose, or nonesterified cholesterol. In the liver, hepatocellular cytomegaly, fatty change, and bile duct hyperplasia occurred in both strains in a dose-related manner, as did thymic and splenic atrophy. Necrosis of germinal epithelium in the testes and edema in the stomach submucosa occurred at acutely toxic doses. These lesions also occurred at doses 8-24X greater in d/d than in b/b mice. Thus, the spectrum of toxicity is independent of the allele at the Ah locus, but the relative dose needed to bring about various acute responses is approximately 8-24X greater in congenic mice homozygous

  2. Paternal occupational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin and birth outcomes of offspring: birth weight, preterm delivery, and birth defects.

    PubMed

    Lawson, Christina C; Schnorr, Teresa M; Whelan, Elizabeth A; Deddens, James A; Dankovic, David A; Piacitelli, Laurie A; Sweeney, Marie H; Connally, L Barbara

    2004-10-01

    Agent Orange is a phenoxy herbicide that was contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). We studied pregnancy outcomes among wives of male chemical workers who were highly exposed to chemicals contaminated with TCDD and among wives of nonexposed neighborhood referents. For exposed pregnancies, we estimated serum TCDD concentration at the time of conception using a pharmacokinetic model. The mean TCDD concentration for workers' births was 254 pg/g lipid (range, 3-16,340 pg/g). The mean referent concentration of 6 pg/g was assigned to pregnancies fathered by workers before exposure. A total of 1,117 live singleton births of 217 referent wives and 176 worker wives were included. Only full-term births were included in the birth weight analysis (greater than or equal to 37 weeks of gestation). Mean birth weight among full-term babies was similar among referents' babies (n = 604), preexposure workers' babies (n = 221), and exposed workers' babies (n = 292) (3,420, 3,347, and 3,442 g, respectively). Neither continuous nor categorical TCDD concentration had an effect on birth weight for term infants after adjustment for infant sex, mother's education, parity, prenatal cigarette smoking, and gestation length. An analysis to estimate potential direct exposure of the wives during periods of workers' exposure yielded a nonstatistically significant increase in infant birth weight of 130 g in the highest exposure group (TCDD concentration > 254 pg/g) compared with referents (p = 0.09). Mothers' reports of preterm delivery showed a somewhat protective association with paternal TCDD (log) concentration (odds ratio = 0.8; 95% confidence interval, 0.6-1.1). We also include descriptive information on reported birth defects. Because the estimated TCDD concentrations in this population were much higher than in other studies, the results indicate that TCDD is unlikely to increase the risk of low birth weight or preterm delivery through a paternal mechanism. Key words

  3. The thermodynamic properties of 4,5,9,10-tetrahydropyrene and 1,2,3,6,7,8-hexahydropyrene

    SciTech Connect

    Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.; Smith, N.K.; Steele, W.V.

    1992-12-01

    Measurements leading to the calculation of the ideal-gas thermodynamic properties are reported for 4,5,9,10-tetrahydropyrene and 1,2,3,6,7,8-hexahydropyrene. Experimental methods included combustion calorimetry, adiabatic heat-capacity calorimetry, vibrating-tube densitometry, comparative ebulliometry, inclined-piston gauge manometry, and differential-scanning calorimetry (d.s.c.). Critical properties were estimated for both materials based on the measurement results. Entropies, enthalpies, and Gibbs energies of formation were derived for the ideal gases for selected temperatures between 380 K and 700 K. The property-measurement results reported here for 4,5,9,10-tetrahydropyrene and 1,2,3,6,7,8-hexahydropyrene are the first for these important intermediates in the pyrene/H{sub 2} hydrogenation reaction network.

  4. Potentiation and antagonism of 2,3,7,8-tetrachlorodibenzo-p-dioxin effects in a complex environmental mixture.

    PubMed

    Silkworth, J B; Cutler, D S; O'Keefe, P W; Lipinskas, T

    1993-04-01

    There is increasing need to understand the toxicity of complex environmental mixtures. The organic phase of a leachate (OPL) from the Love Canal chemical dump site is a complex mixture that contains over 100 organic compounds, including 0.74 ppm 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Mice congenic at the Ah locus were used to evaluate several toxic effects of the OPL, including immune function and hepatic enzyme induction. OPL toxicity was compared with that of pure TCDD in both C57BL/6J Ahb/b and congenic C57BL/6 Ahd/d (B6.D2) mice. Mice were given single oral doses of up to 2 g OPL/kg or 100 micrograms TCDD/kg, immunized, and evaluated after 7 days. The TCDD equivalent of the OPL was determined to be 3.9 and 5.0 ppm in C57BL/6J and B6.D2 mice, respectively. This is six times the TCDD content. The Ah phenotype-dependent response ratio was calculated by dividing the dose required to cause an effect in the B6.D2 strain by the dose causing the same effect in the C57BL/6J strain. Ratios based on both ED50s and the lowest observed adverse effect levels were used to determine whether each adverse effect was Ah phenotype-dependent, the extent to which TCDD contributed to the effect, whether there were interactive effects between the AhR ligands and nonligands and if they were additive, antagonistic, or synergistic, and whether the response was predictable based on the known chemical composition of the mixture. It was concluded that the non-TCDD component potentiated TCDD immune suppression, and possibly thymic atrophy, through AhR mechanisms. In contrast, this analysis indicated that the non-TCDD component of the OPL antagonized the ability of the TCDD component to induce hepatic AHH activity whereas OPL hepatomegaly was caused primarily by the non-TCDD component of the OPL. This study demonstrates that the toxicity of mixtures containing TCDD may not be accurately predicted based on the TCDD content alone and that this approach could be useful in the toxicologic

  5. 2,3,7,8-TCDD enhances the sensitivity of mice to concanavalin A immune-mediated liver injury

    SciTech Connect

    Fullerton, Aaron M.; Roth, Robert A.; Ganey, Patricia E.

    2013-01-15

    Inflammation plays a major role in immune-mediated liver injury, and exposure to environmental pollutants such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been reported to alter the inflammatory response as well as affect immune cell activity. In this study, we tested the hypothesis that TCDD pretreatment exacerbates hepatotoxicity in a murine model of immune-mediated liver injury induced by concanavalin A (Con A) administration. Mice were pretreated with 30 μg/kg TCDD or vehicle control on day zero and then given either Con A or saline intravenously on day four. Mice treated with TCDD did not develop liver injury; however, TCDD pretreatment increased liver injury resulting from moderate doses of Con A (4–10 mg/kg). TCDD-pretreated mice had altered plasma concentrations of inflammatory cytokines, including interferon gamma (IFNγ), and TCDD/Con A-induced hepatotoxicity was attenuated in IFNγ knockout mice. At various times after treatment, intrahepatic immune cells were isolated, and expression of cell activation markers as well as cytolytic proteins was determined. TCDD pretreatment increased the proportion of activated natural killer T (NKT) cells and the percent of cells expressing Fas ligand (FasL) after Con A administration. In addition FasL knockout mice and mice treated with CD18 antiserum were both protected from TCDD/Con A-induced hepatotoxicity, suggesting a requirement for direct cell–cell interaction between effector immune cells and parenchymal cell targets in the development of liver injury from TCDD/Con A treatment. In summary, exposure to TCDD increased NKT cell activation and exacerbated immune-mediated liver injury induced by Con A through a mechanism involving IFNγ and FasL expression. -- Highlights: ► TCDD pretreatment sensitizes mice to Con A-induced hepatotoxicity. ► TCDD pretreatment increased concentration of IFNγ in plasma after Con A. ► Con A-induced activation of NKT cells was increased by TCDD pretreatment. ► Fas

  6. Possible Interactions between the 2012 Mw 7.8 Haida Gwaii Subduction Earthquake and the Transform Queen Charlotte Fault

    NASA Astrophysics Data System (ADS)

    Hobbs, T. E.; Cassidy, J. F.; Dosso, S. E.

    2014-12-01

    This paper examines the effect of the October 2012 Mw 7.8 Haida Gwaii earthquake on aftershock nodal planes and the neighboring Queen Charlotte Fault (QCF) through Coulomb modeling and directivity analysis. The Haida Gwaii earthquake was the largest thrust event recorded in this region and ruptured an area of ~150 by 40 km on a gently NE-dipping fault off the west coast of Moresby Island, British Columbia. It is particularly interesting as it is located just to the west of the QCF, the predominantly right-lateral strike-slip fault separating the Pacific and North American plates. The QCF was the site of the largest recorded earthquake in Canada: the 1949 Ms 8.1 strike-slip earthquake whose rupture extended as far south as this 2012 event and roughly as far north as an Mw7.5 strike slip event at Craig, Alaska, which occurred just two months later in January 2013. The 75 km long portion of the QCF south of the 1949 rupture has not had a large (M ≥ 7) earthquake in over 116 years, representing a significant seismic gap. Coulomb stress transfer analysis is performed using finite fault models which incorporate seismic and geodetic data. Static stress changes are projected onto aftershock nodal planes and the QCF, including an inferred southern seismic gap. We find up to 86% of aftershocks are consistent with triggering, and as high as 96% for normal faulting events. The QCF experiences static stress changes greater than the empirically-determined threshold for triggering, with positive stress changes predicted for roughly half of the seismic gap region. Added stress from the mainshock and a lack of post-mainshock events make this seismic gap a likely location for future earthquakes. Empirical Green's function and directivity analyses are also performed to constrain rupture kinematics of the mainshock using systematic azimuthal variations in relative source time functions. Results indicate rupture progressed mainly to the northwest within 15o of the direction of the

  7. The 14 November, 2007 Mw 7.8 Tocopilla, northern Chile earthquake within the Iquique seismic gap

    NASA Astrophysics Data System (ADS)

    Schurr, B.; Motagh, M.; Krüger, F.; Asch, G.; Anderssohn, J.; Sobiesiak, M.; Kind, R.; Sodoudi, F.; Ohrnberger, M.; Chong Díaz, G.; Vilotte, J.; Oncken, O.

    2008-05-01

    A prominent seismic gap persisted in northern Chile between the towns of Antofagasta and Arica for 130 years. This 500 km segment along the South American subduction zone last ruptured in 1877 in a devastating M9 earthquake. On November 14th 2007, an Mw 7.8 earthquake started near the coastal town of Tocopilla to break the southernmost 200 km of the seismic gap. In Tocopilla and several other communities in the backcountry, a majority of the structures were destroyed. Commencing in 2006, in close cooperation between the GFZ Potsdam (Germany), IPG Paris (France), the Universidad Catolica del Norte, Antofagasta and Universidad de Chile, Santiago (Chile), a network of 15 observatories equipped with seismic broadband and strong motion sensors, GPS receivers and magnetotelluric probes is being established to monitor the seismic gap. At the time of the Tocopilla earthquake, 12 sites were already deployed with the seismological instruments. Based on these data we relocate the mainshock and early aftershocks. The surface deformation field derived from InSAR data in Wide Swath and Image modes from ascending and descending tracks will be inverted for a distributed slip model using a grid of rectangular dislocations in an elastic half-space. We use broadband stations at teleseismic distances to image the spatio-temporal characteristics of seismic energy release during the earthquake. This analysis indicates a rupture length of approximately 200 km with almost unilateral southward propagation and a duration of approximately 200s. Rupture terminated on Mejillones Peninsula, exactly where an earlier large earthquake, the Mw 8 1995 Antofagasta event, had its northern limit. This is also where most of the early aftershocks focus. The structure beneath the Mejillones Peninsula seems to form a persistent barrier in the northern Chilean earthquake cycle. Based on our analysis, the fault plane of the Tocopilla earthquake fills roughly the southernmost third of the Iquique seismic gap

  8. Organocatalyzed enantioselective synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carboxylates

    PubMed Central

    Ramireddy, Naresh; Abbaraju, Santhi; Zhao, Cong-Gui

    2011-01-01

    The organocatalyzed enantioselective synthesis of biologically active 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carboxylate derivatives was achieved using bifunctional cinchona alkaloids as the catalysts. Using quinine thiourea as the catalyst, the tandem Michael addition-cyclization reaction between 1,3-cyclohexanediones and alkylidenecyanoacetate derivatives gives the desired products in high yields (up to 92%) and good ee values (up to 82%). PMID:22081731

  9. Discovery and Rational Design of Pteridin-7(8H)-one-Based Inhibitors Targeting FMS-like Tyrosine Kinase 3 (FLT3) and Its Mutants.

    PubMed

    Sun, Deheng; Yang, Yu; Lyu, Jiankun; Zhou, Wei; Song, Wenlin; Zhao, Zhenjiang; Chen, Zhuo; Xu, Yufang; Li, Honglin

    2016-07-14

    FLT3 has been validated as a therapeutic target for the treatment of acute myeloid leukemia (AML). In this paper, we describe for the first time, pteridin-7(8H)-one as a scaffold for potent FLT3 inhibitors derived from structural optimizations on irreversible EGFR inhibitors. The representative inhibitor (31) demonstrates single-digit nanomolar inhibition against FLT3 and subnanomolar KD for drug-resistance FLT3 mutants. In profiling of the in vitro tumor cell lines, it shows good selectivity against AML cells harboring FLT3-ITD mutations over other leukemia and solid tumor cell lines. The mechanism of action study illustrates that pteridin-7(8H)-one derivatives suppress the phosphorylation of FLT3 and its downstream pathways, thereby inducing G0/G1 cell cycle arrest and apoptosis in AML cells. In in vivo studies, 31 significantly suppresses the tumor growth in MV4-11 xenograft model. Overall, we provide a structurally distinct chemical scaffold with which to develop FLT3 mutants-selective inhibitors for AML treatment.

  10. Evaluation of toxicological biomarkers in secreted proteins of HepG2 cells exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin and their expressions in the plasma of rats and incineration workers.

    PubMed

    Phark, Sohee; Park, So-Young; Chang, Yoon-Seok; Choi, Seonyoung; Lim, Ji-youn; Kim, Yoonjin; Seo, Jong Bok; Jung, Woon-Won; Sul, Donggeun

    2016-05-01

    Toxicological biomarkers of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) were investigated in proteins secreted by HepG2 cells and their expression levels were determined in the plasma of rats exposed to 2,3,7,8-TCDD and in the plasma of incineration workers exposed to dioxins. HepG2 cells were treated with various concentrations of 2,3,7,8-TCDD (0, 0.25, 0.5, 1, 2.5, 5, 10, 25 nM) for 24 or 48 h. MTT and Comet assays were performed to determine cytotoxicities and genotoxicities to select exposure concentrations for the proteomic analysis of proteins secreted by 2,3,7,8-TCDD-treated cells. In the proteomic analysis, dose- and time-dependent toxicological biomarkers were evaluated using two pI ranges (4-7 and 6-9) using a large gel 2-DE system. Fifteen secreted proteins were identified by a nano-LC-ESI-MS/MS and nano-ESI on a Q-TOF2 MS and the identities of eight secreted proteins including glyoxalase 1 (GLO 1), homogentisate dioxygenase (HGD), peroxiredoxin 1 (PRX 1), proteasome subunit beta type (PSMB) 5 and 6, UDP-glucose 6-dehydrogenase (UDP-GlcDH), hydroxyacyl-coenzyme A dehydrogenase (HADH) and serotransferrin (STF) were confirmed by western blotting. Of these, PSMB 5 and PRX 1 were also found in the plasma of rats exposed to 2,3,7,8-TCDD, whereas GLO 1, HGD, PSMB 6 and PRX 1 were found in the plasma of incineration workers exposed to dioxins.

  11. Determination of ( sup 3 H)-2,3,7,8-tetrachlorodibenzo-p-dioxin in human feces to ascertain its relative metabolism in man

    SciTech Connect

    Wendling, J.M.; Orth, R.G.; Poiger, H. )

    1990-04-15

    Human feces samples from a self-dosing experiment were analyzed by gas chromatography/mass spectrometry (GC/MS) for ({sup 3}H)-2,3,7,8-tetrachlorodibenzo-p-dioxin ({sup 3}H-2378-TCDD) to determine that 36-44% of the radioactivity was attributable to the parent compound. This method, using isotope dilution analysis, proved to be difficult due to the unexpectedly higher native 2378-TCDD background which created abnormally large precision ranges around the calculated feces concentrations of 0.1-0.2 pg/g. These results were supported by additional analyses involving the GC/MS chemical cleanup method combined with liquid scintillation counting which showed that at most, 50% of the radioactivity was due to 2378-TCDD metabolites resulting in a minimum metabolism of 50% for these samples.

  12. Study of Interpolated Timing Recovery Phase-Locked Loop with Linearly Constrained Adaptive Prefilter for Higher-Density Optical Disc

    NASA Astrophysics Data System (ADS)

    Kajiwara, Yoshiyuki; Shiraishi, Junya; Kobayashi, Shoei; Yamagami, Tamotsu

    2009-03-01

    A digital phase-locked loop (PLL) with a linearly constrained adaptive filter (LCAF) has been studied for higher-linear-density optical discs. LCAF has been implemented before an interpolated timing recovery (ITR) PLL unit in order to improve the quality of phase error calculation by using an adaptively equalized partial response (PR) signal. Coefficient update of an asynchronous sampled adaptive FIR filter with a least-mean-square (LMS) algorithm has been constrained by a projection matrix in order to suppress the phase shift of the tap coefficients of the adaptive filter. We have developed projection matrices that are suitable for Blu-ray disc (BD) drive systems by numerical simulation. Results have shown the properties of the projection matrices. Then, we have designed the read channel system of the ITR PLL with an LCAF model on the FPGA board for experiments. Results have shown that the LCAF improves the tilt margins of 30 gigabytes (GB) recordable BD (BD-R) and 33 GB BD read-only memory (BD-ROM) with a sufficient LMS adaptation stability.

  13. Intelligent control and adaptive systems; Proceedings of the Meeting, Philadelphia, PA, Nov. 7, 8, 1989

    NASA Technical Reports Server (NTRS)

    Rodriguez, Guillermo (Editor)

    1990-01-01

    Various papers on intelligent control and adaptive systems are presented. Individual topics addressed include: control architecture for a Mars walking vehicle, representation for error detection and recovery in robot task plans, real-time operating system for robots, execution monitoring of a mobile robot system, statistical mechanics models for motion and force planning, global kinematics for manipulator planning and control, exploration of unknown mechanical assemblies through manipulation, low-level representations for robot vision, harmonic functions for robot path construction, simulation of dual behavior of an autonomous system. Also discussed are: control framework for hand-arm coordination, neural network approach to multivehicle navigation, electronic neural networks for global optimization, neural network for L1 norm linear regression, planning for assembly with robot hands, neural networks in dynamical systems, control design with iterative learning, improved fuzzy process control of spacecraft autonomous rendezvous using a genetic algorithm.

  14. Analysis of breast milk to assess exposure to chlorinated contaminants in Kazakhstan: sources of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposures in an agricultural region of southern Kazakhstan.

    PubMed

    Hooper, K; Chuvakova, T; Kazbekova, G; Hayward, D; Tulenova, A; Petreas, M X; Wade, T J; Benedict, K; Cheng, Y Y; Grassman, J

    1999-06-01

    High levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; up to 208 pg/g fat) were measured in samples of breast milk collected in 1997 from 64 donors [41 first-time mothers (primiparae)] living on state farms in southern Kazakhstan. TCDD was the major contributor (70%) to the toxic equivalents, matching the congener patterns found in breast milk and serum samples collected in 1994 and 1996 from donors in nearby villages. The highest TCDD levels were found in state farms adjacent to a reservoir (zone A), which receives agricultural runoff from cotton fields. TCDD levels in zone A were significantly higher than levels in a region more distant (zone B; > 10 miles) from the reservoir (zone A: mean 53 pg/g, n = 17; zone B: mean 21 pg/g, n = 24; p = 0.0017). Levels of TCDD in breast milk and animal-derived foodstuffs were 10 times U.S. levels. Body burden and dietary data suggest that exposures to TCDD are chronic, environmental, and long term and may be related to the use of chemicals in cotton agriculture. The data suggest that the most likely source is the use of cotton defoliants contaminated with TCDD, and the most likely pathway for human exposure is via the consumption of contaminated foodstuffs.

  15. Analysis of breast milk to assess exposure to chlorinated contaminants in Kazakhstan: sources of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposures in an agricultural region of southern Kazakhstan.

    PubMed Central

    Hooper, K; Chuvakova, T; Kazbekova, G; Hayward, D; Tulenova, A; Petreas, M X; Wade, T J; Benedict, K; Cheng, Y Y; Grassman, J

    1999-01-01

    High levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; up to 208 pg/g fat) were measured in samples of breast milk collected in 1997 from 64 donors [41 first-time mothers (primiparae)] living on state farms in southern Kazakhstan. TCDD was the major contributor (70%) to the toxic equivalents, matching the congener patterns found in breast milk and serum samples collected in 1994 and 1996 from donors in nearby villages. The highest TCDD levels were found in state farms adjacent to a reservoir (zone A), which receives agricultural runoff from cotton fields. TCDD levels in zone A were significantly higher than levels in a region more distant (zone B; > 10 miles) from the reservoir (zone A: mean 53 pg/g, n = 17; zone B: mean 21 pg/g, n = 24; p = 0.0017). Levels of TCDD in breast milk and animal-derived foodstuffs were 10 times U.S. levels. Body burden and dietary data suggest that exposures to TCDD are chronic, environmental, and long term and may be related to the use of chemicals in cotton agriculture. The data suggest that the most likely source is the use of cotton defoliants contaminated with TCDD, and the most likely pathway for human exposure is via the consumption of contaminated foodstuffs. Images Figure 1 Figure 2 Figure 3 PMID:10515712

  16. Analysis of the tsunami generated by the MW 7.8 1906 San Francisco earthquake

    USGS Publications Warehouse

    Geist, E.L.; Zoback, M.L.

    1999-01-01

    We examine possible sources of a small tsunami produced by the 1906 San Francisco earthquake, recorded at a single tide gauge station situated at the opening to San Francisco Bay. Coseismic vertical displacement fields were calculated using elastic dislocation theory for geodetically constrained horizontal slip along a variety of offshore fault geometries. Propagation of the ensuing tsunami was calculated using a shallow-water hydrodynamic model that takes into account the effects of bottom friction. The observed amplitude and negative pulse of the first arrival are shown to be inconsistent with small vertical displacements (~4-6 cm) arising from pure horizontal slip along a continuous right bend in the San Andreas fault offshore. The primary source region of the tsunami was most likely a recently recognized 3 km right step in the San Andreas fault that is also the probable epicentral region for the 1906 earthquake. Tsunami models that include the 3 km right step with pure horizontal slip match the arrival time of the tsunami, but underestimate the amplitude of the negative first-arrival pulse. Both the amplitude and time of the first arrival are adequately matched by using a rupture geometry similar to that defined for the 1995 MW (moment magnitude) 6.9 Kobe earthquake: i.e., fault segments dipping toward each other within the stepover region (83??dip, intersecting at 10 km depth) and a small component of slip in the dip direction (rake=-172??). Analysis of the tsunami provides confirming evidence that the 1906 San Francisco earthquake initiated at a right step in a right-lateral fault and propagated bilaterally, suggesting a rupture initiation mechanism similar to that for the 1995 Kobe earthquake.

  17. Developmental and posthatch effects of in ovo exposure to 2,3,7,8-TCDD, 2,3,4,7,8-PECDF, and 2,3,7,8-TCDF in Japanese quail (Coturnix japonica), common pheasant (Phasianus colchicus), and white leghorn chicken (Gallus gallus domesticus) embryos.

    PubMed

    Cohen-Barnhouse, Andrew M; Zwiernik, Matthew J; Link, Jane E; Fitzgerald, Scott D; Kennedy, Sean W; Giesy, John P; Wiseman, Steve; Jones, Paul D; Newsted, John L; Kay, Denise; Bursian, Steven J

    2011-07-01

    An egg injection study was conducted to confirm a proposed model of relative sensitivity of three avian species to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-like chemicals. It was previously reported that the order of species sensitivity to in ovo exposure to TCDD, 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), or 2,3,7,8-tetrachlorodibenzofuran (TCDF) at doses ranging from 0.044 to 37 picomoles (pmol)/g egg was the chicken (Gallus gallus domesticus), common pheasant (Phasianus colchicus), and Japanese quail (Coturnix japonica) based on embryo mortality and hepatic enzyme induction. In the present study, the incidence of developmental deformities, changes in body and relative organ masses, and organ pathology of hatchlings as additional indicators of species sensitivity were assessed; in addition, embryo mortality in the three species was categorized by stage of development. Embryo mortality varied temporally with significant increases generally occurring after organogenesis and just prior to hatching. A significant increase in the percentage of developmental deformities was observed only in Japanese quail exposed to TCDF. Body and relative organ masses of quail, pheasants, and chickens dosed in ovo with TCDD, PeCDF, or TCDF were not consistently affected. Chemical-related pathology occurred only in livers of quail at the greatest doses of each compound. These results indicated that the incidence of developmental deformities, changes in body and relative organ masses and organ pathology could not be used as indicators of species sensitivity or chemical potency.

  18. Dystonia and tremor following exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Klawans, H.L.

    1987-01-01

    Forty-seven railroad workers who were exposed to polychlorinated phenols, including dioxin (TCDD), during 1979 while cleaning up the chemical spillage following damage to a tank car filled with these chemicals were followed medically for the subsequent 6 years. Two committed suicide. The initial neurological complaints included a sense of fatigue and muscle aching, both of which have been reported in other individuals following dioxin exposure. On detailed neurological examination in December, 1985, 24 of 45 had dystonic writer's cramp and/or other action dystonias of the hands. None of the involved individuals had a family history of dystonia, and all 24 dated the onset of the dystonia to the first 2 to 3 years subsequent to their toxic exposure. The dystonias varied in severity but were usually mild. No other types of dystonic involvement were recognized. Thirty-five of the 45 individuals also manifested postural and terminal intention tremor which resembled benign essential tremor. None of the involved individuals had a family history of tremor, and all 35 of those affected dated the onset of the tremor to some time subsequent to their toxic exposure. Forty-three of 45 patients had histories and findings suggestive of peripheral neuropathy. This is the first report relating any type of dystonia to prior dioxin exposure and the first report relating action dystonia, such as dystonic writer's cramp, and postural/terminal intention tremor, to toxic exposure of any type.

  19. 2,3,4,7,8-Pentachlorodibenzofuran is far less potent than 2,3,7,8-tetrachlorodibenzo-p-dioxin in disrupting the pituitary–gonad axis of the rat fetus

    SciTech Connect

    Taura, Junki; Takeda, Tomoki; Fujii, Misaki; Hattori, Yukiko; Ishii, Yuji; Kuroki, Hiroaki; Tsukimori, Kiyomi; Uchi, Hiroshi; Furue, Masutaka; Yamada, Hideyuki

    2014-11-15

    The effect of 2,3,4,7,8-pentachlorodibenzofuran (PnCDF) on the fetal pituitary–gonad axis was compared with that produced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in Wistar rats. Maternal treatment at gestational day (GD) 15 with PnCDF and TCDD reduced the fetal expression at GD20 of pituitary luteinizing hormone (LH) and the testicular proteins necessary for steroidogenesis. The relative potencies of PnCDF ranged from 1/42nd to 1/63rd of the TCDD effect. While PnCDF, at a dose sufficient to cause a reduction in fetal LH, provoked defects in sexual behavior at adulthood, a dose less than the ED{sub 50} failed to produce any abnormality. There was a loss of fetal body weight following in utero exposure to PnCDF, and the effect of PnCDF was also much less than that of TCDD. The disturbance in fetal growth was suggested to be due to a reduction in the level of fetal growth hormone (GH) by dioxins. The disorder caused by PnCDF/TCDD in the fetal pituitary–gonad axis occurred at doses less than those needed to cause wasting syndrome in pubertal rats. The harmful effect of PnCDF relative to TCDD was more pronounced in fetal rats than in pubertal rats. These lines of evidence suggest that: 1) PnCDF as well as TCDD imprints defects in sexual behavior by disrupting the fetal pituitary–gonad axis; 2) these dioxins hinder fetal growth by reducing the expression of fetal GH; and 3) the fetal effects of PnCDF/TCDD are more sensitive than sub-acute toxicity during puberty, and the relative effect of PnCDF varies markedly depending on the indices used. - Highlights: • 2,3,4,7,8-Pentachlorodibenzofuran (PnCDF) lowers gonadal steroidogenesis in fetuses. • PnCDF exerts the above effect through an initial attenuation in gonadotropin level. • PnCDF imprints sexual immaturity by transiently disrupting the pituitary–gonad axis. • PnCDF also disturbs pup growth probably due to a reduction in growth hormone level. • The above effects are far lesser in PnCDF than 2,3,7,8

  20. The Campus in Hard Times. New York's Higher Education Crisis. How It Happened. How It Can Be Resolved.

    ERIC Educational Resources Information Center

    Paley, Henry D.

    How did the New York State system of colleges and universities arrive at the brink of fiscal disaster? What is a possible new perception of higher education financing for New York? The radical shift in enrollment from independent to government-sponsored campuses, and the steep escalation in tax-levy burden for higher education resulted in the New…

  1. The 14 November 2001 Mw=7.8 Kokoxili Earthquake In Northern Tibet (qinghai, China)

    NASA Astrophysics Data System (ADS)

    van der Woerd, J.; Meriaux, A.-S.; Klinger, Y.; Tapponnier, P.; Ryerson, F. J.; Gaudemer, Y.

    On 14 November, 2001, at 5:26 pm local time (9:26:10.3 GMT) an earthquake with Ms=8.1 struck the Kokoxili region of the northwest part of Qinghai Province (China). The earthquake appears to have ruptured the left-lateral Kunlun Fault which extends roughly east-west for about 1600 km in north Tibet. This event follows, nearly four years later, the 8 November 1997, Mw=7.6 Manyi earthquake. Here we discuss the rupture parameters (total length, maximum displacement, style of faulting), the posi- tions of the largest aftershocks, and possible triggering scenarios for future earthquake occurrence, based on preliminary interpretations of high resolution satellite imagery. The preliminary epicenter (USGS NEIC) is located near 90.5rE, about 300 km west of the Golmud-Lhasa road across which surface rupture has been reported near the Kunlun Pass. The centroid (Harvard), at 35.5rN92.7rE, lies about 200 km east of the USGS and CSB preliminary epicentral locations, and about 35 km south of the fault, consistent with a south-dipping fault-plane. Two focal mechanisms, one from the Har- vard CMT Catalog, and the other, from the Earthquake Information Center in Tokyo (ERI, Tokyo), indicate pure left-lateral to normal-left-lateral motion on a N90-96rE striking plane, compatible with the average N95-100rE strike of the Kunlun Fault in the area. The USGS fault plane solution, on the other hand, appears to be radically dif- ferent, but would not be inconsistent with slip on a steep, N20rE-trending normal fault plane. 18 of the 22 aftershocks with magnitude Mb * 3.8 that occurred during the first week are located another 100 km farther east, between 93rE and 94.7rE. The source duration of the event was 120 seconds and the bulk of the energy was dissipated east- wards in about 80 seconds (ERI, Tokyo). It is thus likely that the rupture started in the west, and propagated eastwards along much of the length of the Kusai segment ( 270 km) with most of the seismic energy radiated along the

  2. Evaluation of the oral subchronic toxicity of HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-gamma-2 -benzopyran) in the rat.

    PubMed

    Api, A M; Ford, R A

    1999-12-20

    1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-gamma-2-ben zopyran (HHCB) is used in a wide variety of fragrances in consumer products. Because of the widespread exposure to this material, a 90-day oral feeding study in accordance with OECD guidelines No. 408, with 4-week recovery periods for selected rats, was conducted. HHCB was added to the diet of rats at levels calculated to result in mean daily doses of 5, 15, 50 or 150 mg HHCB/kg. On completion of the treatment period, three males and three females from the high dose and control groups were maintained for a treatment free period of 4 weeks. No adverse effects were revealed from clinical examination or following extensive histopathological examinations. There were no significant findings at any dose level; a NOAEL of 150 mg/kg per day was concluded. As a supplement to the main study, histopathological examination of the prostate, seminal vesicles, mammary gland and testes of males and ovaries, mammary gland, uterus and vagina of females was undertaken on all animals in all test groups. This examination did not reveal any evidence of hormonal effects.

  3. Bioaccumulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin, 2,3,7,8-tetrachlorodibenzofuran and extractable organic chlorine at a bleached-kraft mill site in a northern Canadian river system

    SciTech Connect

    Owens, J.W. ); Swanson, S.M. ); Birkholz, D.A. )

    1994-02-01

    Abiotic and biotic environmental compartments in a northern Canadian river system have been analyzed for poly-chlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and extractable organochlorines (EOCl) down-stream of a bleached-kraft mill. The water column, deposited and suspended sediments, invertebrates, and tissues from several fish species were analyzed. The data indicate that (a) conversion of the mill bleaching process to 100% chlorine dioxide virtually eliminated the discharge of PCDDs and PCDFs; (b) PCDD, PCDF, and EOCl transport occurred primarily in suspended sediments; and (c) the food choice of filter-feeding insects by specific fish species such as the mountain whitefish (Prosopium williamsoni) was an important determinant in the food-chain transfer of the principal compounds, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 2,3,7,8-tetrachlorodibenzofuran (TCDF). Relative to mountain whitefish, TCDD and TCDF levels in another bottom feeding species, longnose sucker (Catostomus catostomus), were at least an order of magnitude lower. Food-chain biomagnification of TCDD and TCDF was not observed in omnivorous and predatory species, burbot (Lota lota) and walleye (Stizostedium vitreum), for which lipid-adjusted levels were similar to those in the longnose sucker. These data indicate that organism lipid levels alone are not sufficient to predict species-specific bioaccumulation of these hydrophobic compounds, and that site-specific transport and species food choice parameters should be included in bioaccumulation models for hydrophobic compounds such as PCDDs and PCDFs.

  4. Energetic neutral atoms (E approximately 50 keV) from the ring current - IMP 7/8 and ISEE 1

    NASA Technical Reports Server (NTRS)

    Roelof, E. C.; Mitchell, D. G.; Williams, D. J.

    1985-01-01

    Energetic neutral atoms (ENA), emitted from the magnetosphere with energies of about 50 keV, have been measured with solid state detectors on the IMP 7/8 and ISEE 1 spacecraft; they are produced when singly charged trapped ions collide with the exosphere neutral hydrogen geocorona and the energetic ions are neutralized by charge exchange. ENA observations during the recovery phase of two moderate geomagnetic storms are analyzed: November 22-23, 1973, from IMP 8 at 33 earth radii and December 17, 1977, from ISEE 1 at 20 earth radii.

  5. Effect of thyroidectomy and thyroxine on 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced immunotoxicity

    SciTech Connect

    Pazdernik, T.L.; Rozman, K.K.

    1985-02-18

    Radiothyroidectomy protected against 2,3,7,8-tetrachloro dibenzo-p-dioxin (TCDD)-induced immunotoxicity in rats as assessed by the spleen anti-SRBC plaque-forming cell assay. Thyroxin (T/sub 4/) replacement therapy partially reversed the effects of thyroidectomy on T/sub 4/ and triiodothyronine (T/sub 3/) serum levels, body weight and immune function as well as restored TCDD-induced immunotoxicity. Thus, hypothyroidism induced by TCDD exposure can be viewed as a protective response of the organism to reduce the insult caused by TCDD.

  6. The Imidazoquinoline Toll-Like Receptor-7/8 Agonist Hybrid-2 Potently Induces Cytokine Production by Human Newborn and Adult Leukocytes

    PubMed Central

    Ganapathi, Lakshmi; Van Haren, Simon; Dowling, David J.; Bergelson, Ilana; Shukla, Nikunj M.; Malladi, Subbalakshmi S.; Balakrishna, Rajalakshmi; Tanji, Hiromi; Ohto, Umeharu; Shimizu, Toshiyuki; David, Sunil A.; Levy, Ofer

    2015-01-01

    Background Newborns and young infants are at higher risk for infections than adults, and manifest suboptimal vaccine responses, motivating a search for novel immunomodulators and/or vaccine adjuvants effective in early life. In contrast to most TLR agonists (TLRA), TLR8 agonists such as imidazoquinolines (IMQs) induce adult-level Th1-polarizing cytokine production from human neonatal cord blood monocytes and are candidate early life adjuvants. We assessed whether TLR8-activating IMQ congeners may differ in potency and efficacy in inducing neonatal cytokine production in vitro, comparing the novel TLR7/8-activating IMQ analogues Hybrid-2, Meta-amine, and Para-amine to the benchmark IMQ resiquimod (R848). Methods TLRA-induced NF-κB activation was measured in TLR-transfected HEK cells. Cytokine production in human newborn cord and adult peripheral blood and in monocyte-derived dendritic cell cultures were measured by ELISA and multiplex assays. X-ray crystallography characterized the interaction of human TLR8 with Hybrid-2. Results Hybrid-2 selectively activated both TLR7 and 8 and was more potent than R848 in inducing adult-like levels of TNF-α, and IL-1β. Consistent with its relatively high in vitro activity, crystallographic studies suggest that absence in Hybrid-2 of an ether oxygen of the C2-ethoxymethyl substituent, which can engage in unfavorable electrostatic and/or dipolar interactions with the carbonyl oxygen of Gly572 in human TLR8, may confer greater efficacy and potency compared to R848. Conclusions Hybrid-2 is a selective and potent TLR7/8 agonist that is a candidate adjuvant for early life immunization. PMID:26274907

  7. Educational Family Background and the Realisation of Educational Career Intentions: Participation of German Upper Secondary Graduates in Higher Education over Time

    ERIC Educational Resources Information Center

    Weiss, Felix; Steininger, Hanna-Marei

    2013-01-01

    In this article, we evaluate the impact of social origin on the realisation of educational intentions at the time of becoming eligible for higher education in Germany. In general, we find high persistence of intentions and actual attendance of higher education. However, effects of parental education on the changes of educational intentions…

  8. Bisubstrate analogue inhibitors of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase: New lead exhibits a distinct binding mode

    PubMed Central

    Shi, Genbin; Shaw, Gary; Li, Yue; Wu, Yan; Yan, Honggao; Ji, Xinhua

    2012-01-01

    6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK), a key enzyme in the folate biosynthesis pathway catalyzing the pyrophosphoryl transfer from ATP to 6-hydroxymethyl-7,8-dihydropterin, is an attractive target for developing novel antimicrobial agents. Previously, we studied the mechanism of HPPK action, synthesized bisubstrate analogue inhibitors by linking 6-hydroxymethylpterin to adenosine through phosphate groups, and developed a new generation of bisubstrate inhibitors by replacing the phosphate bridge with a piperidine-containing linkage. To further improve linker properties, we have synthesized a new compound, characterized its protein binding/inhibiting properties, and determined its structure in complex with HPPK. Surprisingly, this inhibitor exhibits a new binding mode in that the adenine base is flipped when compared to previously reported structures. Furthermore, the side chain of amino acid residue E77 is involved in protein-inhibitor interaction, forming hydrogen bonds with both 2' and 3' hydroxyl groups of the ribose moiety. Residue E77 is conserved among HPPK sequences, but interacts only indirectly with the bound MgATP via water molecules. Never observed before, the E77-ribose interaction is compatible only with the new inhibitor-binding mode. Therefore, this compound represents a new direction for further development. PMID:22727779

  9. Sequence-dependent off-target inhibition of TLR7/8 sensing by synthetic microRNA inhibitors.

    PubMed

    Sarvestani, Soroush T; Stunden, H James; Behlke, Mark A; Forster, Samuel C; McCoy, Claire E; Tate, Michelle D; Ferrand, Jonathan; Lennox, Kim A; Latz, Eicke; Williams, Bryan R G; Gantier, Michael P

    2015-01-01

    Anti-microRNA (miRNA) oligonucleotides (AMOs) with 2'-O-Methyl (2'OMe) residues are commonly used to study miRNA function and can achieve high potency, with low cytotoxicity. Not withstanding this, we demonstrate the sequence-dependent capacity of 2'OMe AMOs to inhibit Toll-like receptor (TLR) 7 and 8 sensing of immunostimulatory RNA, independent of their miRNA-targeting function. Through a screen of 29 AMOs targeting common miRNAs, we found a subset of sequences highly inhibitory to TLR7 sensing in mouse macrophages. Interspecies conservation of this inhibitory activity was confirmed on TLR7/8 activity in human peripheral blood mononuclear cells. Significantly, we identified a core motif governing the inhibitory activity of these AMOs, which is present in more than 50 AMOs targeted to human miRNAs in miRBaseV20. DNA/locked nucleic acids (LNA) AMOs synthesized with a phosphorothioate backbone also inhibited TLR7 sensing in a sequence-dependent manner, demonstrating that the off-target effects of AMOs are not restricted to 2'OMe modification. Taken together, our work establishes the potential for off-target effects of AMOs on TLR7/8 function, which should be taken into account in their therapeutic development and in vivo application. PMID:25539920

  10. Sequence-dependent off-target inhibition of TLR7/8 sensing by synthetic microRNA inhibitors

    PubMed Central

    Sarvestani, Soroush T.; Stunden, H. James; Behlke, Mark A.; Forster, Samuel C.; McCoy, Claire E.; Tate, Michelle D.; Ferrand, Jonathan; Lennox, Kim A.; Latz, Eicke; Williams, Bryan R.G.; Gantier, Michael P.

    2015-01-01

    Anti-microRNA (miRNA) oligonucleotides (AMOs) with 2′-O-Methyl (2′OMe) residues are commonly used to study miRNA function and can achieve high potency, with low cytotoxicity. Not withstanding this, we demonstrate the sequence-dependent capacity of 2′OMe AMOs to inhibit Toll-like receptor (TLR) 7 and 8 sensing of immunostimulatory RNA, independent of their miRNA-targeting function. Through a screen of 29 AMOs targeting common miRNAs, we found a subset of sequences highly inhibitory to TLR7 sensing in mouse macrophages. Interspecies conservation of this inhibitory activity was confirmed on TLR7/8 activity in human peripheral blood mononuclear cells. Significantly, we identified a core motif governing the inhibitory activity of these AMOs, which is present in more than 50 AMOs targeted to human miRNAs in miRBaseV20. DNA/locked nucleic acids (LNA) AMOs synthesized with a phosphorothioate backbone also inhibited TLR7 sensing in a sequence-dependent manner, demonstrating that the off-target effects of AMOs are not restricted to 2′OMe modification. Taken together, our work establishes the potential for off-target effects of AMOs on TLR7/8 function, which should be taken into account in their therapeutic development and in vivo application. PMID:25539920

  11. Analysis of 7,8-Dihydro-8-oxo-2′-deoxyguanosine in Cellular DNA during Oxidative Stress

    PubMed Central

    2009-01-01

    Analysis of cellular 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxo-dGuo) as a biomarker of oxidative DNA damage has been fraught with numerous methodological problems. This is primarily due to artifactual oxidation of dGuo that occurs during DNA isolation and hydrolysis. Therefore, it has become necessary to rely on using the comet assay, which is not necessarily specific for 8-oxo-dGuo. A highly specific and sensitive method based on immunoaffinity purification and stable isotope dilution liquid chromatography (LC)-multiple reaction monitoring (MRM)/mass spectrometry (MS) that avoids artifact formation has now been developed. Cellular DNA was isolated using cold DNAzol (a proprietary product that contains guanidine thiocyanate) instead of chaotropic- or phenol-based methodology. Chelex-treated buffers were used to prevent Fenton chemistry-mediated generation of reactive oxygen species (ROS) and artifactual oxidation of DNA bases. Deferoxamine was also added to all buffers in order to complex any residual transition metal ions remaining after Chelex treatment. The LC-MRM/MS method was used to determine that the basal 8-oxo-dGuo level in DNA from human bronchoalveolar H358 cells was 2.2 ± 0.4 8-oxo-dGuo/107 dGuo (mean ± standard deviation) or 5.5 ± 1.0 8-oxo-dGuo/108 nucleotides. Similar levels were observed in human lung adenocarcinoma A549 cells, mouse hepatoma Hepa-1c1c7 cells, and human HeLa cervical epithelial adenocarcinoma cells. These values are an order of magnitude lower than is typically reported for basal 8-oxo-dGuo levels in DNA as determined by other MS- or chromatography-based assays. H358 cells were treated with increasing concentrations of potassium bromate (KBrO3) as a positive control or with the methylating agent methyl methanesulfonate (MMS) as a negative control. A linear dose−response for 8-oxo-dGuo formation (r2 = 0.962) was obtained with increasing concentrations of KBrO3 in the range of 0.05 mM to 2.50 mM. In contrast, no 8-oxo-dGuo was

  12. CHARACTERIZATION OF STABLE BENZO(A)PYRENE-7,8-QUINONE-DNA ADDUCTS IN CALF THYMUS DNA

    EPA Science Inventory

    Benzo[alpyrene-7,8-dione (BPQ) is a reactive aldo-keto reductase-mediated product of B[a]P-7,8-diol, a major P450/epoxide hydrolase metabolite of the multi-species carcinogen, B[a]P. The role of BPQ in B[a]P's genotoxicity and carcinogenesis is evolving. Toxicity pathways involvi...

  13. LC/MSMS STUDY OF BENZO[A]PYRENE-7,8-QUINONE ADDUCTION TO GLOBIN TRYPTIC PEPTIDES AND N-ACETYLAMINO ACIDS

    EPA Science Inventory

    Benzo[a]pyrene-7,8-quinone (BPQ) is regarded as a reactive genotoxic compound enzymatically formed from a xenobiotic precursor benzo[a]pyrene-7,8-diol by aldo-keto-reductase family of enzymes. Because BPQ, a Michael electrophile, was previously shown to react with oligonucleotide...

  14. CHARACTERIZATION OF STABLE BENZOLALPYRENE-7,8-QUINONE-DNA ADDUCTS IN CALF THYMUS DNA AND POLYDEOXYNUCLEOTIDES

    EPA Science Inventory

    Bcnzo[a]pyrene-7,8-dione (BPQ) is a reactive aldo-keto reductase-mediated product of B[a]P-7,8-diol, a major P450/epoxide hydrolase metabolite of the multi-species carcinogen, B[a]P. The role of BPQ in B[a]P's genotoxicity and carcinogenesis is evolving. Toxicity pathways involvi...

  15. A Call to Action on New England's Innovation Economy: Will Business and Higher Education Answer This Time?

    ERIC Educational Resources Information Center

    Guenther, William

    2003-01-01

    Mass Insight Corp, a public policy and communications firm that organizes public-private initiatives to support economic growth in Massachusetts, recently issued a new report, titled "An Economy at Risk," making the case for a Massachusetts economic development strategy organized around higher education and science and technology. Massachusetts,…

  16. Universities' Autonomy in Times of Changing Higher Education Governance: A Study of the Swiss Academic Labour Market

    ERIC Educational Resources Information Center

    Baschung, Lukas; Goastellec, Gaele; Leresche, Jean-Philippe

    2011-01-01

    Although eternally debated, the issue of autonomy in higher education is rarely analysed in its complexity. To address this issue, this article uses an analytical matrix which combines the distinction between substantive and procedural autonomy and the distinction between HEI governing bodies, academic professions and individual academics. This…

  17. Breaking the Mold: New Approaches for Higher Education in Tough Economic Times. Complete to Compete Briefing Paper

    ERIC Educational Resources Information Center

    Carey, Kevin

    2011-01-01

    Human capital is the key to economic development. Without highly-skilled workers, states and territories cannot attract the productive businesses they need. That makes higher education a key element of any governor's growth strategy. But many public colleges and universities are struggling to produce more graduates. Overall graduation rates often…

  18. Quality after the Cuts? Higher Education Practitioners' Accounts of Systemic Challenges to Teaching Quality in Times of "Austerity"

    ERIC Educational Resources Information Center

    Feigenbaum, Anna; Iqani, Mehita

    2015-01-01

    What are the ramifications of current changes in the higher education landscape in the UK for the ways in which teaching staff perceive their teaching practices? What impact are funding cuts, increases in student fees and the concomitant increased workloads having on faculty morale? How might this influence "quality cultures" in teaching…

  19. Australian Higher Education Leaders in Times of Change: The Role of Pro Vice-Chancellor and Deputy Vice-Chancellor

    ERIC Educational Resources Information Center

    Scott, Geoff; Bell, Sharon; Coates, Hamish; Grebennikov, Leonid

    2010-01-01

    This paper discusses responses provided by 31 Pro Vice-Chancellors (PVCs) and Deputy Vice-Chancellors (DVCs) who were part of a larger study of more than 500 higher education leaders in roles ranging from DVC to head of programme in 20 Australian universities. Using both quantitative and qualitative data the paper gives an insider's perspective on…

  20. A Lesson of Lost Political Capital in Public Higher Education: Leadership Challenges in a Time of Needed Organizational Change

    ERIC Educational Resources Information Center

    Hilton, Mark; Jacobson, Rod

    2012-01-01

    All higher education institutions are struggling with a rapidly changing market and financial landscape. Here is a management-centered analysis of what happened when a college president, recognizing the need to make a radical adaptation to those changes, tried moving a campus community to a new organizational model, without collegial consensus,…

  1. Applying the Modality Principle to Real-Time Feedback and the Acquisition of Higher-Order Cognitive Skills

    ERIC Educational Resources Information Center

    Fiorella, Logan; Vogel-Walcutt, Jennifer J.; Schatz, Sae

    2012-01-01

    Effectively presenting complex material is a crucial component of instructional design within simulation-based training (SBT) environments. One approach to facilitate the acquisition of higher-order knowledge is to embed instructional strategies within the systems themselves. Currently, however, there are few established guidelines to inform…

  2. A Time of Quiet Activism: Research, Practice, and Policy in American Women's Higher Education, 1945-1965

    ERIC Educational Resources Information Center

    Eisenmann, Linda

    2005-01-01

    This article reflects on three narratives that affected American women's participation in higher education during the first twenty years after World War II. In hindsight, the educators of the 1950s and early 1960s may seem gratuitously meek and self-effacing. In comparison to later efforts, their activism can appear unnecessarily limited and too…

  3. Unprecedented Times in the Professionalisation and State Regulation of Counselling and Psychotherapy: The Role of the Higher Education Institute

    ERIC Educational Resources Information Center

    Murphy, David

    2011-01-01

    This article considers a number of issues facing those involved in counselling and psychotherapy training within United Kingdom Higher Education Institutes. It is proposed that the increasing professionalisation of counselling and psychotherapy has significant implications for lecturers and trainers. The article will explore the tension between…

  4. Just-in-Time Research: A Call to Arms for Research into Mobile Technologies in Higher Education

    ERIC Educational Resources Information Center

    Byrne-Davis, Lucie; Dexter, Hilary; Hart, Jo; Cappelli, Tim; Byrne, Ged; Sampson, Ian; Mooney, Jane; Lumsden, Colin

    2015-01-01

    Mobile technologies are becoming commonplace in society and in education. In higher education, it is crucial to understand the impact of constant access to information on the development of the knowledge and competence of the learner. This study reports on a series of four surveys completed by UK-based medical students (n = 443) who received…

  5. Funding System of Full-Time Higher Education and Technical Efficiency: Case of the University of Ljubljana

    ERIC Educational Resources Information Center

    Tajnikar, Maks; Debevec, Jasmina

    2008-01-01

    The present paper tackles the issue of the higher education funding system in Slovenia. Its main attribute is that institutions are classified into study groups according to their fields of education, and funds granted by the state are based on their weights or study group factors (SGF). Analysis conducted using data envelopment analysis tested…

  6. Synthesis and characterization of p-type conductivity dopant 2-(3-(adamantan-1-yl)propyl)-3,5,6-trifluoro-7,7,8,8-tetracyanoquinodimethane

    SciTech Connect

    Rainbolt, James E.; Koech, Phillip K.; Polikarpov, Evgueni; Swensen, James S.; Cosimbescu, Lelia; Von Ruden, Amber L.; Wang, Liang; Sapochak, Linda S.; Padmaperuma, Asanga B.; Gaspar, Daniel J.

    2013-01-22

    We report the synthesis and characterization of 2-(3-(adamantan-1-yl)propyl)-3,5,6-trifluoro-7,7,8,8-tetracyanoquinodimethane (F3TCNQ-Ad1), a substituted analog of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), designed for p-type conductivity doping. The dopant is designed as a model for substituted alternatives to F4TCNQ that maintain similar electronic properties with the goal of engineering dopants with superior fabrication characteristics over F4TCNQ. We describe the design strategy for F3TCNQ-Ad1 based on molecular modeling predictions that substitution of a single fluorine atom of F4TCNQ has little effect on the electronic properties of the molecule. Photophysical and electrochemical characterization reveal that the adamantyl substituent in F3TCNQ-Ad1 does not significantly alter the electronic properties of the substituted dopant relative to F4TCNQ. Unfortunately, F3TCNQ-Ad1 degrades under standard sublimation conditions, preventing sublimation deposition processing. Instead, hole-only devices were made via solution-processing of the p-doped films with the structure glass/ITO/2.3 x103Å PVK:(MTDATA:dopant)/2.0x102Å Au/1.0x103Å Al, where dopant is either F4TCNQ or F3TCNQ-Ad1. We demonstrate that F3TCNQ-Ad1 increased the conductivity of the films by at least 1,000 times compared to an undoped device.

  7. Pharmacokinetics of ( sup 125 I)-2-iodo-3,7,8-trichlorodibenzo-p-dioxin in mice: Analysis with a physiological modeling approach

    SciTech Connect

    Leung, H.W.; Poland, A.; Paustenbach, D.J.; Murray, F.J.; Andersen, M.E. )

    1990-05-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a potent inducer of hepatic microsomal enzymes. The influence of an inducing dose of TCDD on tissue distribution and other pharmacokinetic behavior of a TCDD analog in the mice was examined by employing a high specific activity radioligand. (125I)-2-iodo-3,7,8-trichlorodibenzo-p-dioxin (ITCDD). Female C57BL/6J mice were pretreated with 0.1 mumol/kg of TCDD or the vehicle only, followed by 0.1 nmol ITCDD/kg 3 days later. The control animals had the highest concentration of ITCDD-derived radioactivity in the fat, but the TCDD-pretreated animals had the highest concentration in their livers. Whole-body elimination of ITCDD approximated first-order behavior, and induction by pretreatment with the inducing dose of TCDD almost doubled the rate of excretion (control mice, t1/2 = 14.2 days; pretreated mice, t1/2 = 8.0 days). All disposition results in naive and pretreated mice were satisfactorily described by a consistent physiologically based pharmacokinetic model in which induction increased the amount of microsomal ITCDD-binding protein from 1.75 to 20 nmol/liver and increased the rate constant for metabolism of free ITCDD from 1 to 3/hr/kg liver. The binding affinity of the microsomal ITCDD-binding protein was the same (20 nM) in both induced and noninduced mice. Model simulations indicated a time delay in the elimination of nonparent ITCDD metabolites from the body and a more rapid absorption of the parent ligand in the pretreated mice. Consistent with previous physiological modeling with TCDD in different mouse strains, the primary factor influencing the liver/fat concentration ratio appears to be the affinity and capacity of the microsomal TCDD-binding proteins, which are altered by induction.

  8. Full-Time Employed Students as University Consumers--Consequences and Triggers of Marketisation of Higher Education

    ERIC Educational Resources Information Center

    Mägi, Eve; Jaakson, Krista; Aidla, Anne; Kirss, Laura; Reino, Anne

    2012-01-01

    This article draws on a qualitative study of student employment patterns among students who both study and work full-time. In the study, 17 employed bachelor students at state-commissioned study places in three Estonian universities, 12 lecturers from the same universities, and 13 employers supervising those full-time students, were interviewed.…

  9. Maintaining Quality in Troubled Times. Pacific Rim Association for Higher Education Annual Conference (2nd, Seattle, Washington, October 13-14, 1981).

    ERIC Educational Resources Information Center

    Pacific Rim Association for Higher Education.

    Proceedings of the Pacific Rim Association for Higher Education 1981 conference are summarized. Authors and the summarized papers are as follows: "Maintaining Quality in Troubled Times: The University Perspective" (George M. Beckmann); "Maintaining Quality in Troubled Times: The Community College Perspective" (Don A. Morgan); "Report from China"…

  10. The Hidden Benefits of Part-Time Higher Education Study to Working Practices: Is There a Case for Making Them More Visible?

    ERIC Educational Resources Information Center

    Callender, Claire; Little, Brenda

    2015-01-01

    Within the UK, part-time study is now seen as important in meeting wider government objectives for higher education (HE) and for sustainable economic growth through skills development. Yet, measures to capture the impact of HE may not be wholly appropriate to part-time study. In particular, the continuing focus on tangible, economic measures may…

  11. 2,3,7,8-Tetrachlorodibenzo-p-dioxin in breast milk increases autistic traits of 3-year-old children in Vietnam.

    PubMed

    Nishijo, M; Pham, T T; Nguyen, A T N; Tran, N N; Nakagawa, H; Hoang, L V; Tran, A H; Morikawa, Y; Ho, M D; Kido, T; Nguyen, M N; Nguyen, H M; Nishijo, H

    2014-11-01

    Dioxin levels in the breast milk of mothers residing near a contaminated former airbase in Vietnam remain much higher than in unsprayed areas, suggesting high perinatal dioxin exposure for their infants. The present study investigated the association of perinatal dioxin exposure with autistic traits in 153 3-year-old children living in a contaminated area in Vietnam. The children were followed up from birth using the neurodevelopmental battery Bayley-III. The high-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposed groups (⩾3.5 pg per g fat) showed significantly higher Autism Spectrum Rating Scale (ASRS) scores for both boys and girls than the mild-TCDD exposed groups, without differences in neurodevelopmental scores. In contrast, the high total dioxin-exposed group, indicated by polychlorinated dibenzo-p-dioxins/furans (PCDDs/Fs)--the toxic equivalents (TEQ) levels⩾17.9 pg-TEQ per g fat, had significantly lower neurodevelopmental scores than the mild-exposed group in boys, but there was no difference in the ASRS scores. The present study demonstrates a specific impact of perinatal TCDD on autistic traits in childhood, which is different from the neurotoxicity of total dioxins (PCDDs/Fs).

  12. 2,3,7,8-Tetrachlorodibenzo-p-dioxin equivalents in tissues of birds at Green Bay, Wisconsin, USA

    USGS Publications Warehouse

    Jones, Paul D.; Giesy, John P.; Newsted, John L.; Verbrugge, David A.; Beaver, Donald L.; Ankley, Gerald T.; Tillitt, Donald E.; Lodge, Keith B.; Niemi, Gerald J.

    1993-01-01

    The environment has become contaminated with complex mixtures of planar, chlorinated hydrocarbons (PCHs) such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and structurally similar compounds. Because the potencies of individual congeners to cause the same adverse effects vary greatly and the relative as well as absolute concentrations of individual PCH vary among samples from different locations, it is difficult to assess the toxic effects of these mixtures on wildlife. These compounds can cause a number of adverse effects, however, because the toxic effects which occur at ecologically-relevant concentrations such as embryo-lethality and birth defects appear to be mediated through the same mechanism, the potency of individual congeners can be reported relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) which is the most toxic congener in the PCH class. The concentations of 2,3,7,8-TCDD Equivalents (TCDD-EQ) were determined in the tissues of aquatic and terrestrial birds of Green Bay, Wisconsin by the H4IIE bioassay system and compared toxic equivalency factors (TEFs) with the concentration predicted by the use of toxic equivalency factors applied to concentrations of PCH, which were determined by instrumental analyses. Concentrations of TCDD-EQ ranged from 0.52 to 440 ng/kg, wet weight. The greatest concentrations occurred in the fish-eating birds. Concentrations of TCDD-EQ, which were determined by the two methods were significantly correlated, but the additive model which used the TEFs with concentrations of measured PCB, PCDD and PCDF congeners underestimated the concentrations of TCDD-EQ measured by the H4IIE bioassay by an average of 57%. This is thought to be due to contributions from un-quantified PCH, which are known to occur in the environment. Of the quantified PCH congeners, PCDD and PCDF contributed a small portion of the TCDD-EQ in the aquatic birds, while most of the

  13. Serum 2,3,7,8-tetrachlorodibenzo-p-dioxin levels in Air Force health study participants - preliminary report

    SciTech Connect

    Not Available

    1988-06-24

    In 1978, the US Air Force responded to a congressional mandate to initiate an epidemiologic study of the possible health effects of exposure to herbicides and their 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) contaminants in Air Force veterans who served in the Ranch Hand defoliation operation during the Vietnam conflict. Accordingly, the Air Force conducted a nonconcurrent prospective study, the Air Force Health Study, of all 1267 members of the Ranch Hand unit and a series of matched controls. This phase of the Air Force study focused on measuring serum TCDD levels in 150 Ranch Hand veterans and 50 controls. All participants were enlisted men; the Ranch Hand veterans had been either herbicide loaders or herbicide specialists in Vietnam. The demographic and health characteristics of Ranch Hand personnel and controls were similar; however, their serum TCDD levels differed markedly.

  14. Footprints of past earthquakes revealed in the afterslip of the 2010 Mw 7.8 Mentawai tsunami earthquake

    NASA Astrophysics Data System (ADS)

    Feng, Lujia; Barbot, Sylvain; Hill, Emma M.; Hermawan, Iwan; Banerjee, Paramesh; Natawidjaja, Danny H.

    2016-09-01

    The 2010 Mw 7.8 Mentawai tsunami earthquake marks one of the first tsunami earthquakes to have postseismic deformation observed by geodetic instruments. The Sumatran GPS Array has recorded the postseismic deformation following this event continuously for >5 years. The spatiotemporal evolution of the postseismic deformation is well explained by velocity-strengthening frictional sliding on the Sunda megathrust. Our results show that the 2010 afterslip progressed downdip relative to the 2010 coseismic rupture. The southeastern portion of the afterslip region overlaps the area that slipped during the main shock and afterslip of the 2007 Mw 8.4 Bengkulu earthquake, while the northwestern portion slipped an area without recent large earthquakes. By incorporating pre-earthquake stress conditions into quasi-dynamic models, we demonstrate that the preceding cumulative slip from the 2007 sequence might have caused a ˜0.1 MPa difference in pre-earthquake Coulomb stress between the southeastern and northwestern portions of the afterslip region.

  15. Familial complex autosomal translocations involving chromosomes 7, 8, and 9 exhibiting male and female transmission with segregation and recombination.

    PubMed Central

    Walker, S; Howard, P J; Hunter, D

    1985-01-01

    A family showing a complex translocation between chromosomes 7, 8, and 9 with breakpoints at 7q21, 7q33, 8p23, and 9p23 is described. The proband had been referred because of repeated spontaneous abortions. This is only the second family to be ascertained in this way. Twenty-three other cases of complex translocations are briefly reviewed, eight of which were de novo in origin and 15 familial. All but one of the familial cases showed maternal transmission only. The present family shows both maternal and paternal transmission and is thought to be the first exhibiting recombination from a male carrier. The origin and transmission of the complex translocation is followed through three generations. Images PMID:3841161

  16. Biochemical and histological responses in rainbow trout (Oncorhynchus mykiss) exposed to 2,3,4,7,8-pentachlorodibenzofuran

    SciTech Connect

    Brown, S.B.; Evans, R.E.; Lockhart, W.L.; Delorme, P.D.; Ward, F.J.; Muir, D.C.G.

    1998-01-01

    Rainbow trout were given an intraperitoneal injection of corn oil containing 0 or 8.8 nmol (3 {micro}g) [{sup 14}C]2,3,4,7,8-pentachlorodibenzofuran (P{sub 5}CDF)/kg and were then held on a light cycle that induced spawning 10 months later. At 5- to 6-week intervals, blood samples were collected to monitor plasma levels of 17{beta}-estradiol (E{sub 2}), testosterone (T), thyroxine (T{sub 4}), 3,5,3{prime}-triiodo-L-thyronine (T{sub 3}), and calcium; packed cell volume (PCV); and differential blood cell counts. Fish were sacrificed after spawning to examine tissue P{sub 5}CDF concentration, liver ethoxyresorufin-O-deethylase (EROD), liver vitamins (retinoids and tocopherol), histology (liver, thyroid), and growth parameters. The P{sub 5}CDF injections produced tissue 2,3.7,8-tetrachlorodibenzo-p-dioxin toxic equivalent concentrations comparable to those reported in salmonids from contaminated areas. Highest P{sub 5}CDF concentrations occurred in gut and liver, but muscle accounted for the greatest proportion of the dose. Plasma hormone and calcium concentrations followed predicted seasonal patterns in both control and exposed fish. PCV was unchanged by repeated blood sampling but differential blood cell counts showed adaptive responses to blood removal. The P{sub 5}CDF exposure caused transient reductions in circulating lymphocytes and elevated EROD. Additionally, P{sub 5}CDF increased liver size and depleted retinoid stores in male fish. Liver histology, somatic growth, and gonadal development were unaltered by P{sub 5}CDF during the first reproductive cycle after exposure.

  17. A television in the bedroom is associated with higher weekday screen time among youth with attention deficit hyperactivity disorder (ADD/ADHD)

    PubMed Central

    Lo, Charmaine B.; Waring, Molly E.; Pagoto, Sherry L.; Lemon, Stephenie C.

    2014-01-01

    Objective A TV in the bedroom has been associated with screen time in youth. Youth with attention deficit hyperactivity disorder (ADD/ADHD) have higher rates of screen time, but associations with bedroom TVs are unknown in this population. We examined the association of having a bedroom TV with screen time among youth with ADD/ADHD. Methods Data were from the 2007 National Survey of Children's Health. Youth 6–17 years whose parent/guardian reported a physician's diagnosis of ADD/ADHD (n = 7024) were included in the analysis. Parents/guardians reported the presence of a bedroom TV and average weekday TV screen time. Multivariate linear and logistic regression models assessed the effects of a bedroom on screen time. Results Youth with ADD/ADHD engaged in screen time with an average of 149.1 min/weekday and 59% had a TV in their bedroom. Adjusting for child and family characteristics, having a TV in the bedroom was associated with 25 minute higher daily screen time (95% CI: 12.8–37.4 min/day). A bedroom TV was associated with 32% higher odds of engaging in screen time for over 2 h/day (OR = 1.3; 95% CI: 1.0–1.7). Conclusion Future research should explore whether removing TVs from bedrooms reduces screen time among youth with ADD/ADHD. PMID:25599016

  18. Estimates of the half-life of 2,3,7,8-tetrachlorodibenzo-p-dioxin in Vietnam veterans of operation ranch hand

    SciTech Connect

    Pirkle, J.L.; Wolfe, W.H.; Patterson, D.G.; Needham, L.L.; Philips, D.L. ); Michalek, J.E.; Miner, J.C.; Peterson, M.R. )

    1989-01-01

    A half-life of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD; commonly known as dioxin) in serum has been measured in 36 Air Force Vietnam Veterans of Operation Ranch Hand, which was the operation that aerially sprayed the herbicide Agent Orange in Vietnam. From serum specimens taken in 1982 and 1987, the median half-life of 2,3,7,8-TCDD in these Ranch Hand veterans was found to be 7.1 yr (95% confidence interval about the median of 5.8-9.6 yr). These veterans reported no civilian exposure to dioxin or herbicides. Concentrations of 2,3,7,8-TCDD in the 1982 serum specimens from these veterans ranged from 16.9 to 423 parts per trillion on a lipid weight basis. The half-life estimates were not associated with the concentration of 2,3,7,8-TCDD in the 1982 serum specimens. This half-life of 7.1 yr is much longer than the half-life of 2,3,7,8-TCDD reported in animals but is consistent with recent evidence from other human exposures to 2,3,7,8-TCDD.

  19. Flexible Pedagogies: Part-Time Learners and Learning in Higher Education. Flexible Pedagogies: Preparing for the Future Series

    ERIC Educational Resources Information Center

    McLinden, Michael

    2013-01-01

    This publication focuses on national and international policy initiatives to develop a better understanding of part-time learners and the types of flexibility that may enhance their study especially pedagogically. As part of our five-strand research project "Flexible Pedagogies: preparing for the future" it: (1) highlights the challenges…

  20. The Economic Domino Effect: A Phenomenological Study Exploring Community College Faculty's Lived Experiences during Financial Hard Times in Higher Education

    ERIC Educational Resources Information Center

    Taylor, Tridai A.

    2014-01-01

    This qualitative study explored the lived experiences of eight full-time community college faculty members who taught during the economic crisis of 2008. The study was guided by the central research question, "How do community college faculty members describe their lived experiences regarding the recent economic crisis of 2008 and its impact…

  1. Recruitment and Retention of Full-Time Engineering Faculty, Fall 1980. Higher Education Panel Report Number 52.

    ERIC Educational Resources Information Center

    Atelsek, Frank J.; Gomberg, Irene L.

    The extent of faculty vacancies in colleges of engineering, the effects of such vacancies upon research and instructional programs, and the nature of the competition between academia and industry in hiring engineering faculty were surveyed. The focus is on permanent full-time faculty positions in the following major engineering fields:…

  2. Does a Higher Incidence of Break Times in Primary Schools Result in Children Being More Physically Active?

    ERIC Educational Resources Information Center

    Kobel, Susanne; Kettner, Sarah; Erkelenz, Nanette; Kesztyüs, Dorothea; Steinacker, Jürgen M.

    2015-01-01

    Background: Regular physical activity (PA) has multiple benefits to health; however, the majority of schoolchildren do not reach PA guidelines of 60 minutes of moderate to vigorous PA (MVPA) daily. During the school day, break times are often the only opportunity for children to be physically active. This study investigated PA levels during school…

  3. Social vulnerability analysis of earthquake risk using HAZUS-MH losses from a M7.8 scenario earthquake on the San Andreas fault

    NASA Astrophysics Data System (ADS)

    Noriega, G. R.; Grant Ludwig, L.

    2010-12-01

    Natural hazards research indicates earthquake risk is not equitably distributed. Demographic differences are significant in determining the risks people encounter, whether and how they prepare for disasters, and how they fare when disasters occur. In this study, we analyze the distribution of economic and social losses in all 88 cities of Los Angeles County from the 2008 ShakeOut scenario earthquake. The ShakeOut scenario earthquake is a scientifically plausible M 7.8 scenario earthquake on the San Andreas fault that was developed and applied for regional earthquake preparedness planning and risk mitigation from a compilation of collaborative studies and findings by the 2007 Working Group on California Earthquake Probabilities (WGCEP). The scenario involved 1) developing a realistic scenario earthquake using the best available and most recent earthquake research findings, 2) estimation of physical damage, 3) estimation of social impact of the earthquake, and 4) identifying changes that will help to prevent a catastrophe due to an earthquake. Estimated losses from this scenario earthquake include 1,800 deaths and $213 billion dollars in economic losses. We use regression analysis to examine the relationship between potential city losses due to the ShakeOut scenario earthquake and the cities' demographic composition. The dependent variables are economic and social losses calculated in HAZUS-MH methodology for the scenario earthquake. The independent variables -median household income, tenure and race/ethnicity- have been identified as indicators of social vulnerability to natural disasters (Mileti, 1999; Cutter, 2006; Cutter & Finch, 2008). Preliminary Ordinary Least Squares (OLS) regression analysis of economic losses on race/ethnicity, income and tenure, indicates that cities with lower Hispanic population are associated with lower economic losses. Cities with higher Hispanic population are associated with higher economic losses, though this relationship is

  4. Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on early life stage development of the fathead minnow (Pimephales promelas)

    SciTech Connect

    Winden, P.J.J. de; Donselaar, E.G. van; Herwig, H.J.

    1994-12-31

    Eggs of fathead minnow were exposed to graded concentrations (0.1--100 ppt) of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) at 24 C for 5 days. Exposure started about one hour after fertilization. The medium was refreshed daily. At day 6 (one day posthatching), body lengths were measured. A dose-dependent retardation of growth (from 1 to 30%) was observed in the range from 0.1 to 20 ppt TCDD. At higher concentrations, growth reduction remained the same but mortality still increased. Microscopic observations of the TCDD-exposed embryos revealed a number of deviations from the normal early development. Initial changes consisted of congestion of the blood flow in the caudal tail area and in the yolk sac vascular complex, followed by hemorrhages. At a later stage, pericardial edema and generalized edema were observed. In addition the embryos revealed, anaemia, decreased amounts of dermal and retinal melanin, shortened mandibles, degeneration of heart tissue, absence of swim bladder, decreased utilization of yolk sac material and a curved chords. The results indicate that embryonic development of the fathead minnow is very sensitive to TCDD. It might prove a useful model for further embryotoxic studies.

  5. Evaluation of Inhibition Efficiency for the Detection of Captan, 2,3,7,8-Tetrachlorodibenzodioxin, Pentachlorophenol and Carbosulfan in Water: An Electrochemical Approach.

    PubMed

    Nesakumar, Noel; Ramachandra, Bhat Lakshmishri; Sethuraman, Swaminathan; Krishnan, Uma Maheswari; Rayappan, John Bosco Balaguru

    2016-02-01

    A novel bio-analytical method has been devised based on the change in catalytic activity of acetylcholinesterase (AChE) enzyme induced by captan, carbosulfan, 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and pentachlorophenol (PCP) for the investigation of inhibition efficiency and sensitivity using Pt/ZnO/AChE/Chitosan bioelectrode. The inhibition curves of captan, carbosulfan, TCDD and PCP were similar to Michaelis-Menten curve. TCDD held the minimum inhibitor Michaelis-Menten constant ([Formula: see text]) value (10.2 nM) in comparison with PCP (10.9 nM), carbosulfan (14.5 nM) and captan (7.9 × 10(3) nM). The maximum inhibition of AChE enzyme by captan was about 100 %, which was much higher than that of TCDD (72.7 %), PCP (68.1 %) and carbosulfan (47.7 %). The calculated theoretical sensitivity was in the order of TCDD > PCP > carbosulfan > captan. Comparing with TCDD (35.3 %), PCP (47.8 %) and carbosulfan (20.9 %), only the inhibition efficiency of captan (55.0 %) was the maximum. The developed bioelectrode exhibited high recovery and low relative standard deviation in local tap water samples.

  6. High-resolution seismic tomography of the 2015 Mw7.8 Gorkha earthquake, Nepal: Evidence for the crustal tearing of the Himalayan rift

    NASA Astrophysics Data System (ADS)

    Pei, Shunping; Liu, Hongbing; Bai, Ling; Liu, Yanbing; Sun, Quan

    2016-09-01

    The Mw7.8 Gorkha earthquake struck Nepal and ruptured the boundary between the Indian and Eurasian plates. We conducted 2-D Pg wave tomography to clarify the seismogenic structure and try to understand causal mechanisms for this large earthquake, using the aftershock data recorded by 15 broadband seismic stations located near the China-Nepal border. Our high-resolution results show that coseismic slip area of the main shock is consistent with the high P wave velocity anomaly, and the region of maximum slip has a larger area with higher velocity than the region of initial slip, possibly resulting in the dominant low-frequency radiation of energy observed after the dominant high-frequency radiation of energy in the source rupture process. The boundary between these regions of contrasting high and low seismic velocity anomalies suggests a potential crustal tearing at the southern end of the Tangra Yum Co Rift, possibly resulting from different thrust speeds in the Greater Himalaya.

  7. Impact of 2,3,7,8-TCDD exposure on survival, growth, and behavior of osprey`s breeding in Wisconsin, USA

    SciTech Connect

    Woodford, J.E.; Karasov, W.H.; Meyer, M.W.; Chambers, L.

    1998-07-01

    Osprey (Pandion halieatus) eggs collected from areas 7 km downstream from two bleached-kraft mill facilities from 1992 to 1996 contained much higher levels of 2,3,7,8-tetrachlordibenzo-p-dioxin than eggs collected from two reference areas upstream. Levels in eggs of the remaining planar halogenated hydrocarbon congeners and other nonplanar organochlorines were not statistically different between the contaminated and upstream areas. The authors placed eggs from the contaminated area into nests at both reference areas (group A) and eggs from the reference areas into nests at the contaminated area (group B). No significant differences in egg hatching or chick fledging rates were observed between these groups and nests left unmanipulated at both reference areas (group C) and the contaminated area (group D). Mass increase rates of chicks differed significantly, with the highest rates from group C and the lowest rates from group B. This difference cannot be easily attributed to differences in parental test attentiveness or food provisioning, which were greater at the contaminated area. The authors conclude that although current planar halogenated hydrocarbon exposure levels were not affecting hatching and fledging rates, they may have affected chick growth.

  8. Progress integrating ID-TIMS U-Pb geochronology with accessory mineral geochemistry: towards better accuracy and higher precision time

    NASA Astrophysics Data System (ADS)

    Schoene, B.; Samperton, K. M.; Crowley, J. L.; Cottle, J. M.

    2012-12-01

    It is increasingly common that hand samples of plutonic and volcanic rocks contain zircon with dates that span between zero and >100 ka. This recognition comes from the increased application of U-series geochronology on young volcanic rocks and the increased precision to better than 0.1% on single zircons by the U-Pb ID-TIMS method. It has thus become more difficult to interpret such complicated datasets in terms of ashbed eruption or magma emplacement, which are critical constraints for geochronologic applications ranging from biotic evolution and the stratigraphic record to magmatic and metamorphic processes in orogenic belts. It is important, therefore, to develop methods that aid in interpreting which minerals, if any, date the targeted process. One promising tactic is to better integrate accessory mineral geochemistry with high-precision ID-TIMS U-Pb geochronology. These dual constraints can 1) identify cogenetic populations of minerals, and 2) record magmatic or metamorphic fluid evolution through time. Goal (1) has been widely sought with in situ geochronology and geochemical analysis but is limited by low-precision dates. Recent work has attempted to bridge this gap by retrieving the typically discarded elution from ion exchange chemistry that precedes ID-TIMS U-Pb geochronology and analyzing it by ICP-MS (U-Pb TIMS-TEA). The result integrates geochemistry and high-precision geochronology from the exact same volume of material. The limitation of this method is the relatively coarse spatial resolution compared to in situ techniques, and thus averages potentially complicated trace element profiles through single minerals or mineral fragments. In continued work, we test the effect of this on zircon by beginning with CL imaging to reveal internal zonation and growth histories. This is followed by in situ LA-ICPMS trace element transects of imaged grains to reveal internal geochemical zonation. The same grains are then removed from grain-mount, fragmented, and

  9. [Effect of Cynaropicrin on 2,3,4,7,8-Pentachlorodibenzofuran-induced Wasting Syndrome and Oxidative Stress].

    PubMed

    Yamada, Ken-ichi; Ishii, Yuji; Takeda, Tomoki; Kuroki, Hiroaki; Mitoma, Chikage; Uchi, Hiroshi; Furue, Masutaka; Yamada, Hideyuki

    2015-05-01

    The effect of cynaropicrin that is the major component of an edible plant, artichoke (Cynara scolymus) on 2,3,4,7,8-pentachlorodibenzofuran (PenCDF)-induced toxicity in mice was studied. We evaluated the effect of cynaropicrin on the wasting syndrome and oxidative stress elicited by PenCDF. However, the PenCDF dose-response relationship on the wasting syndrome has been superficial. Therefore, we determined the dose which causes wasting syndrome in C57BL/6J mice, a responsive strain to dioxins. Since 2,3,7,8-tetrachlorodibenzo-p-dioxin (0.1 mg/kg, p.o.) induces hepatic ethoxyresorfin O-deethylase (EROD) activity in mice, we set the doses of PenCDF at 0.3, 1.0, 3.0, 5.0 and 10 mg/kg (once, p.o.) on the basis of its toxic-eqivalency factor (0.3). The wasting syndrome was evaluated by measuring the daily changes of body weight. Thiobarbituric acid-reactive substances were used as an index of oxidative stress. Of PenCDF doses examined, wasting syndrome and oxidative stress took place most markedly in 5 mg/kg. In disagreement with this, EROD activity which is the marker of the aryl hydrocarbon receptor-dependent induction of cytochrome P450 1a1 was elevated most abundantly at 0.3 mg/kg. Then, we examined the effect of cynaropicrin on the wasting syndrome and oxidative stress provoked by PenCDF at 5 mg/kg. However, this compound up to 20 mg/kg (p.o.) did not attenuate PenCDF-induced wasting syndrome. On the contray, PenCDF-induced oxidateive stress was suppressed by cynaropicrin at the highest dose (20 mg/kg), although EROD activity was increased rather than reduced by cynaropicrin at lower doses. Thus, it is suggested that cynaropicrin has an ability to reduce oxidative stress caused by PenCDF. PMID:26226680

  10. Study of simultaneous presence of DD and PP electric fields during the geomagnetic storm of November 7-8, 2004 and resultant TEC variation over the Indian Region

    NASA Astrophysics Data System (ADS)

    Galav, P.; Sharma, Shweta; Rao, S. S.; Veenadhari, B.; Nagatsuma, T.; Pandey, R.

    2014-04-01

    During very intense geomagnetic storm of November 7-8, 2004 simultaneous presence of storm time disturbance dynamo and eastward and westward directed prompt penetration electric fields inferred from the ground based magnetometer data in the 75∘ E sector is presented. Magnetometer observations show that, on the whole, average Δ H variation on 8 November remains below the night time level compared to its quiet day variation. A number of upward and downward excursions have been observed between 0130 UT and 0800 UT in the Δ H variation on 8 November. These excursions in Δ H have been attributed to the episodes of eastward and westward prompt penetrating electric fields. Ionospheric response in the equatorial ionization anomaly region along 75∘ E has also been studied using the total electron content data recorded at five GPS stations, namely Udaipur, Bengaluru (IISC), Hyderabad (HYDE), Maldives (MALD) and Diego Garcia (DGAR). Observation of markedly suppressed EIA, in conjunction with Δ H variation which was m negative during the daytime on 8 November, indicates the presence of an external field of opposite polarity (the disturbance dynamo electric field) that either undermined, or overshadowed the daytime ambient (eastward) electric field to the extent that the equatorial plasma fountain could not become effective.

  11. TrkB activation by 7, 8-dihydroxyflavone increases synapse AMPA subunits and ameliorates spatial memory deficits in a mouse model of Alzheimer's disease.

    PubMed

    Gao, Lei; Tian, Mi; Zhao, Hong-Yun; Xu, Qian-Qian; Huang, Yu-Ming; Si, Qun-Cao; Tian, Qing; Wu, Qing-Ming; Hu, Xia-Min; Sun, Li-Bo; McClintock, Shawn M; Zeng, Yan

    2016-02-01

    We recently demonstrated that activation of tyrosine receptor kinase B (TrkB) by 7, 8-dihydroxyflavone (7, 8-DHF), the selective TrkB agonist, increased surface alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors (AMPARs) AMPA receptor subunit GluR1 (GluA1) subunit expression at the synapses of Fragile X Syndrome mutant mice. This present study investigated the effects of 7, 8-DHF on both memory function and synapse structure in relation to the synapse protein level of AMPARs in the Tg2576 Alzheimer's disease (AD) mouse model. The study found that chronic oral administration of 7, 8-DHF significantly improved spatial memory and minimized dendrite loss in the hippocampus of Tg2576 mice. A key feature of 7, 8-DHF action was the increased expression of both GluA1 and GluA2 at synapses. Interestingly, 7, 8-DHF had no effect on the attenuation of amyloid precursor protein or Aβ exhibiting in the Tg2576 AD brains, yet it activated the phosphorylation of TrkB receptors and its downstream signals including CaMKII, Akt, Erk1/2, and cAMP-response element-binding protein. Importantly, cyclotraxin B (a TrkB inhibitor), U0126 (a Ras-ERK pathway inhibitor), Wortmannin (an Akt phosphorylation inhibitor), and KN-93 (a CaMKII inhibitor) counteracted the enhanced expression and phosphorylation of AMPAR subunits induced by 7, 8-DHF. Collectively, our results demonstrated that 7, 8-DHF acted on TrkB and resolved learning and memory impairments in the absence of reduced amyloid in amyloid precursor protein transgenic mice partially through improved synaptic structure and enhanced synaptic AMPARs. The findings suggest that the application of 7, 8-DHF may be a promising new approach to improve cognitive abilities in AD. We provided extensive data demonstrating that 7, 8-dihydroflavone, the TrkB agonist, improved Tg2576 mice spatial memory. This improvement is correlated with a reversion to normal values of GluA1 and GluA2 AMPA receptor subunits and dendritic

  12. TrkB activation by 7, 8-dihydroxyflavone increases synapse AMPA subunits and ameliorates spatial memory deficits in a mouse model of Alzheimer's disease.

    PubMed

    Gao, Lei; Tian, Mi; Zhao, Hong-Yun; Xu, Qian-Qian; Huang, Yu-Ming; Si, Qun-Cao; Tian, Qing; Wu, Qing-Ming; Hu, Xia-Min; Sun, Li-Bo; McClintock, Shawn M; Zeng, Yan

    2016-02-01

    We recently demonstrated that activation of tyrosine receptor kinase B (TrkB) by 7, 8-dihydroxyflavone (7, 8-DHF), the selective TrkB agonist, increased surface alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors (AMPARs) AMPA receptor subunit GluR1 (GluA1) subunit expression at the synapses of Fragile X Syndrome mutant mice. This present study investigated the effects of 7, 8-DHF on both memory function and synapse structure in relation to the synapse protein level of AMPARs in the Tg2576 Alzheimer's disease (AD) mouse model. The study found that chronic oral administration of 7, 8-DHF significantly improved spatial memory and minimized dendrite loss in the hippocampus of Tg2576 mice. A key feature of 7, 8-DHF action was the increased expression of both GluA1 and GluA2 at synapses. Interestingly, 7, 8-DHF had no effect on the attenuation of amyloid precursor protein or Aβ exhibiting in the Tg2576 AD brains, yet it activated the phosphorylation of TrkB receptors and its downstream signals including CaMKII, Akt, Erk1/2, and cAMP-response element-binding protein. Importantly, cyclotraxin B (a TrkB inhibitor), U0126 (a Ras-ERK pathway inhibitor), Wortmannin (an Akt phosphorylation inhibitor), and KN-93 (a CaMKII inhibitor) counteracted the enhanced expression and phosphorylation of AMPAR subunits induced by 7, 8-DHF. Collectively, our results demonstrated that 7, 8-DHF acted on TrkB and resolved learning and memory impairments in the absence of reduced amyloid in amyloid precursor protein transgenic mice partially through improved synaptic structure and enhanced synaptic AMPARs. The findings suggest that the application of 7, 8-DHF may be a promising new approach to improve cognitive abilities in AD. We provided extensive data demonstrating that 7, 8-dihydroflavone, the TrkB agonist, improved Tg2576 mice spatial memory. This improvement is correlated with a reversion to normal values of GluA1 and GluA2 AMPA receptor subunits and dendritic

  13. Single-Step Synthesis of 5,6,7,8-Tetrahydroindolizines via Annulation of 2-Formylpiperidine and 1,3-Dicarbonyl Compounds.

    PubMed

    Capomolla, Simona S; Lim, Ngiap-Kie; Zhang, Haiming

    2015-07-17

    An expedient single-step synthesis of 5,6,7,8-tetrahydroindolizines has been achieved via the annulation of commercially available 2-formylpiperidine hydrochloride and 1,3-dicarbonyl compounds in THF in the presence of pyrrolidine and 4 Å molecular sieves. A variety of β-ketoesters, ketones, and amides participated in this annulation chemistry, affording the desired 5,6,7,8-tetrahydroindolizines in moderate to good yields.

  14. The interactions of 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD) and 6-methyl-1,3,8-trichlorodibenzofuran (MCDF) in TCDD-induced porphyria

    SciTech Connect

    Yao, Cheng Catsby.

    1989-01-01

    Halogenated aryl hydrocarbon(HAH)-induced porphyria is caused by alteration of porphyrin metabolism and results in the accumulation of hepatic and urinary porphyrins. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (75 {mu}/kg) caused significant increases of hepatic porphyrin levels in C57BL/6 male, female and ovariectomized female, and C57BL/10 male mice 3 weeks after treatment. In contrast, 6-methyl-1,3,8-trichlorodibenzofuran (MCDF) was inactive at a dose of 750 {mu}mol/kg. Cotreatment with MCDF (750 {mu}mol/kg) and 2,3,7,8-TCDD (75 {mu}g/kg) resulted in partial antagonism of 2,3,7,8-TCDD-induced porphyrin accumulation in female but not in male mice. In female C57BL/6 mice, 2,3,7,8-TCDD-induced porphyria was accompanied by the induction of hepatic microsomal aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin O-deethylase (EROD) activities and the inhibition of uroporphyrinogen decarboxylase (UROD) activity. MCDF (750 {mu}mol/kg) did not significantly affect these enzyme activities. In coadministration studies, MCDF partially antagonized 2,3,7,8-TCDD-induced hepatic porphyrin accumulation but did not affect the activities of hepatic AHH, EROD or UROD. These results demonstrate that the induction of the monooxygenase enzyme activities and the inhibition of UROD activity by 2,3,7,8-TCDD and the development of porphyria are not coordinately regulated in C57BL/6 female mice. In cultured chick embryo hepatocytes, 2,3,7,8-TCDD caused a significant increase in porphyrin levels and induced AHH and EROD activities. MCDF and Aroclor 1254 partially antagonized the 2,3,7,8-TCDD induced AHH and EROD activities but not the porphyrin accumulation.

  15. 40 CFR 721.9504 - Silane, triethoxy (3,3,4,4,5,5, 6,6,7,7,8,8,8-tridecafluorooctyl)-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Silane, triethoxy (3,3,4,4,5,5, 6,6,7... Significant New Uses for Specific Chemical Substances § 721.9504 Silane, triethoxy (3,3,4,4,5,5, 6,6,7,7,8,8,8... substance identified as silane, triethoxy (3,3,4,4,5, 5,6,6,7,7,8,8,8-tridecafluorooctyl)- (PMN...

  16. 40 CFR 721.9503 - Silane, (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl)trimethoxy-.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Silane, (3,3,4,4,5,5,6,6,7,7,8,8,9,9... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9503 Silane, (3,3,4,4,5,5,6,6,7,7,8,8... subject to reporting. (1) The chemical substance identified as silane,...

  17. 40 CFR 721.9503 - Silane, (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl)trimethoxy-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Silane, (3,3,4,4,5,5,6,6,7,7,8,8,9,9... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9503 Silane, (3,3,4,4,5,5,6,6,7,7,8,8... subject to reporting. (1) The chemical substance identified as silane,...

  18. 40 CFR 721.9504 - Silane, triethoxy (3,3,4,4,5,5, 6,6,7,7,8,8,8-tridecafluorooctyl)-.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Silane, triethoxy (3,3,4,4,5,5, 6,6,7... Significant New Uses for Specific Chemical Substances § 721.9504 Silane, triethoxy (3,3,4,4,5,5, 6,6,7,7,8,8,8... substance identified as silane, triethoxy (3,3,4,4,5, 5,6,6,7,7,8,8,8-tridecafluorooctyl)- (PMN...

  19. 40 CFR 721.9503 - Silane, (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl)trimethoxy-.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Silane, (3,3,4,4,5,5,6,6,7,7,8,8,9,9... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9503 Silane, (3,3,4,4,5,5,6,6,7,7,8,8... subject to reporting. (1) The chemical substance identified as silane,...

  20. 40 CFR 721.9504 - Silane, triethoxy (3,3,4,4,5,5, 6,6,7,7,8,8,8-tridecafluorooctyl)-.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Silane, triethoxy (3,3,4,4,5,5, 6,6,7... Significant New Uses for Specific Chemical Substances § 721.9504 Silane, triethoxy (3,3,4,4,5,5, 6,6,7,7,8,8,8... substance identified as silane, triethoxy (3,3,4,4,5, 5,6,6,7,7,8,8,8-tridecafluorooctyl)- (PMN...

  1. 40 CFR 721.9503 - Silane, (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl)trimethoxy-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Silane, (3,3,4,4,5,5,6,6,7,7,8,8,9,9... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9503 Silane, (3,3,4,4,5,5,6,6,7,7,8,8... subject to reporting. (1) The chemical substance identified as silane,...

  2. 40 CFR 721.9504 - Silane, triethoxy (3,3,4,4,5,5, 6,6,7,7,8,8,8-tridecafluorooctyl)-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Silane, triethoxy (3,3,4,4,5,5, 6,6,7... Significant New Uses for Specific Chemical Substances § 721.9504 Silane, triethoxy (3,3,4,4,5,5, 6,6,7,7,8,8,8... substance identified as silane, triethoxy (3,3,4,4,5, 5,6,6,7,7,8,8,8-tridecafluorooctyl)- (PMN...

  3. 40 CFR 721.9503 - Silane, (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl)trimethoxy-.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Silane, (3,3,4,4,5,5,6,6,7,7,8,8,9,9... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9503 Silane, (3,3,4,4,5,5,6,6,7,7,8,8... subject to reporting. (1) The chemical substance identified as silane,...

  4. 40 CFR 721.9504 - Silane, triethoxy (3,3,4,4,5,5, 6,6,7,7,8,8,8-tridecafluorooctyl)-.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Silane, triethoxy (3,3,4,4,5,5, 6,6,7... Significant New Uses for Specific Chemical Substances § 721.9504 Silane, triethoxy (3,3,4,4,5,5, 6,6,7,7,8,8,8... substance identified as silane, triethoxy (3,3,4,4,5, 5,6,6,7,7,8,8,8-tridecafluorooctyl)- (PMN...

  5. Metabolism of benzo[a]pyrene and (-)-trans-benzo[a]pyrene-7,8-dihydrodiol by freshly isolated hepatocytes of brown bullheads.

    PubMed

    Steward, A R; Zaleski, J; Sikka, H C

    1990-01-01

    The metabolism of [3H]benzo[a]pyrene (BP) and (-)-trans-[14C]7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (BP-7,8-diol) was studied in freshly isolated hepatocytes of the wild benthic fish, brown bullhead (Ictalurus nebulosus). Bullhead hepatocytes incubated with 40 microM [3H]BP for 1 h metabolized BP to water soluble metabolites which were separated on silica gel t.l.c. plates to reveal conjugates with glucuronic acid, glutathione, and sulfate (51%, 14% and 4% of total metabolites, respectively). Additional metabolites that were extractable with ethyl acetate were separated by reversed phase HPLC to reveal only two major metabolites: BP-9,10-dihydrodiol and BP-7,8-diol (13% and 2.6% of total metabolites, respectively). Hepatocytes isolated from individual fish displayed an 11-fold variability in the rates at which they metabolized BP (756 +/- 167 pmol x mg dry wt-1 x h-1), which correlated negatively (r = -0.7, P less than 0.01) with an 18-fold variability in the glycogen content of the cells. Hepatocytes isolated from the same fish, in parallel incubations under the same optimum conditions, metabolized BP-7,8-diol 4.5-fold faster than they metabolized BP. The variability in the rate of BP-7,8-diol metabolism was about 7-fold. Major metabolites included glutathione conjugates, glucuronides and sulfates (35%, 25% and 30% of total metabolites, respectively). These conjugates, like those formed from BP, were degradable with gamma-glutamyltransferase, beta-glucuronidase and arylsulfatase, respectively. Ethyl acetate extractable metabolites were predominantly isomeric benzo-ring tetrahydrotetrols (9% of total metabolites). In summary, this study indicates that during short-term incubations bull-head hepatocytes metabolize BP and BP-7,8-diol primarily to conjugated derivatives. The usefulness of thin-layer chromatography for the convenient determination of the rate of BP-7,8-diol metabolism is demonstrated.

  6. Wise Moves in Hard Times: Creating & Managing Resilient Colleges & Universities. The Jossey-Bass Higher and Adult Education Series. First Edition.

    ERIC Educational Resources Information Center

    Leslie, David W.; Fretwell, E. K., Jr.

    Based on data gathered on-site at 13 colleges and universities, this volume offers an in-depth analysis of how colleges and universities have been affected by hard times, how they have risen to the challenges, and what their responses mean to the public and its support for higher education. Part 1 describes the study itself in detail and reports…

  7. Building on Strengths in a Time of Retrenchment: Developing an M.Ed. in Higher Education--Student Affairs Emphasis to Train Christian Practitioners

    ERIC Educational Resources Information Center

    Morris, Jason; Haseltine, Jeffrey; Williams, Carol

    2007-01-01

    To gain approval of a new master's degree in difficult financial times, the authors applied strategies that are applicable at other institutions. Using existing internal resources to build on the university's mission was key in developing a new M.Ed. in Higher Education--Student Affairs Emphasis at Abilene Christian University. Creativity and…

  8. Late time acceleration of the 3-space in a higher dimensional steady state universe in dilaton gravity

    SciTech Connect

    Akarsu, Özgür; Dereli, Tekin E-mail: tdereli@ku.edu.tr

    2013-02-01

    We present cosmological solutions for (1+3+n)-dimensional steady state universe in dilaton gravity with an arbitrary dilaton coupling constant w and exponential dilaton self-interaction potentials in the string frame. We focus particularly on the class in which the 3-space expands with a time varying deceleration parameter. We discuss the number of the internal dimensions and the value of the dilaton coupling constant to determine the cases that are consistent with the observed universe and the primordial nucleosynthesis. The 3-space starts with a decelerated expansion rate and evolves into accelerated expansion phase subject to the values of w and n, but ends with a Big Rip in all cases. We discuss the cosmological evolution in further detail for the cases w = 1 and w = ½ that permit exact solutions. We also comment on how the universe would be conceived by an observer in four dimensions who is unaware of the internal dimensions and thinks that the conventional general relativity is valid at cosmological scales.

  9. Speaking rate, voice-onset time, and quantity: the search for higher-order invariants for two Icelandic speech cues.

    PubMed

    Pind, J

    1995-04-01

    The temporal structure of speech has been shown to be highly variable. Speaking rate, stress, and other factors influence the duration of individual speech sounds. The highly elastic nature of speech would seem to pose a problem for the listener, especially with respect to the perception of temporal speech cues such as voice-onset time (VOT) and quantity: How does the listener disentangle those temporal changes which are linguistically significant from those which are extrinsic to the linguistic message? This paper reports data on the behavior of two Icelandic speech cues at different speaking rates. The results show that manipulations of rate have the effect of slightly blurring the distinction between unaspirated and aspirated stops. Despite great changes in the absolute durations of vowels and consonants, the two categories of syllables--V:C and VC:--are nonetheless kept totally distinct. In two perceptual experiments, it is shown that while the ratio of vowel to rhyme duration is the primary cue to quantity and remains invariant at different rates, no such ratio can be defined for VOT. These results imply that quantity is the only one of these two speech cues that is self-normalizing for rate. Models of rate-dependent speech processing need to address this difference.

  10. 7,7,8,8-Tetracyanoquinodimethane based molecular dopants for p-type doping of OLEDs: A theoretical investigation

    SciTech Connect

    Cosimbescu, Lelia; Padmaperuma, Asanga B.; Gaspar, Daniel J.

    2011-11-15

    The array of organic conductivity dopants used for organic light emitting devices (OLED) to reduce the operating voltage and improve power efficiency is extremely limited. Here we report a comparative theoretical study between newly proposed analogs and the standard state-of-the-art conductivity dopant 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ). We used density functional theory to determine the bond lengths, bond angles and electronic properties, such as the energy of the highest occupied molecular orbital (E{sub HOMO}) and lowest occupied molecular orbital (E{sub LUMO}) states, as well as the triplet energies of the novel structures (ET). The ground state structures of the proposed molecules were optimized at the B3LYP/6-31G* level. The results show that substitution of one or two fluorine groups in the F4-TCNQ core with a substituted phenyl ring or other electron withdrawing moieties, will not substantially affect the geometry of the molecule or its electronic ability to accept electrons. The most significant finding was that the phenyl substitutions onto the TCNQ core are nearly perpendicular to the TCNQ plane, and thus there is no electronic communication between the two rings. This is extremely important, as such extension of the {pi} conjugated system would negatively affect the E{sub LUMO} and thus the electron affinity of the molecule.

  11. Reactions of vitamin E and its model compound 2,2,5,7,8-pentamethylchroman-6-ol with ozone

    SciTech Connect

    Liebler, D.C.; Matsumoto, Shigenobu; Matsuo, Mitsuyoshi; Iitaka, Yoichi

    1993-01-01

    Reaction of vitamin E [(R,R,R,)-{alpha}-tocopherol] with ozone in acetonitrile yielded {alpha}-tocopheryl quinone and its precursor 8{alpha}-hydroxytocopherone, which accounted for approximately 30% of the products at <50% {alpha}-tocopherol oxidation. In addition, two novel products were identified as epimers of 10-acetyl-7-(4{prime},8{prime},12{prime}-trimethyl tridecyl)-3,4,7-trimethyl-2-oxo - 1,6-dioxaspiro[4.5]-deca-3,9-diene. These spiro products were formed in equal amounts in a combined yield of approximately 33% after complete {alpha}-tocpherol oxidation. Ozonation of the vitamin E model compound 2,2,5,7,8-pentamethylchroman-6-ol yielded an analogous spiro product, 10-acetyl-3,4,7,7-tetramethyl-2-oxo-1,6-dioxaspiro[4.5]deca-3,9-diene, whose structure was confirmed by X-ray crystallography. The spiro products may be formed by ozone addition to the chroman ring and subsequent rearrangement to ring-opened hydroxyacid products, which yield spiro products by ring closure due to dehydration. Novel spiro products formed by ozonation of vitamin E may be unique markers of ozone interaction with lipid structures that contain vitamin E. 39 refs., 3 figs., 1 tab.

  12. Agent Orange Exposure and 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) in Human Milk.

    PubMed

    Scialli, Anthony R; Watkins, Deborah K; Ginevan, Michael E

    2015-06-01

    Agent Orange was sprayed in parts of southern Vietnam during the U.S.-Vietnam war and was a mixture of two chlorophenoxy herbicides. The mixture was contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). TCDD and other dioxins and furans are measurable in the milk of Vietnamese women. We explored whether the TCDD in milk from these women was from Agent Orange and whether lactational exposure can be a mode of transgenerational effects of TCDD from Agent Orange. A review of the world's literature on milk concentrations of polychlorinated compounds showed the presence of TCDD and other dioxins and furans in all countries that have been assessed. The congener profile of these chemicals, that is, the proportion of different congeners in the sample, can be used to assess the source of milk contamination. Measurements in most countries, including contemporary measurements in Vietnam, are consistent with non-Agent Orange exposure sources, including industrial activities and incineration of waste. Models and supporting human data suggest that TCDD from breastfeeding does not persist in a child past adolescence and that the adult body burden of TCDD is independent of whether the individual was breast- or bottle-fed as a child. These findings suggest that exposure to Agent Orange in Vietnam did not result in persistent transgenerational exposure through human milk.

  13. 2,3,7,8-TCDD effects on visual structure and function in swim-up rainbow trout

    USGS Publications Warehouse

    Carvalho, Paulo S. M.

    2004-01-01

    An understanding of mechanisms of contaminant effects across levels of biological organization is essential in ecotoxicology if we are to generate predictive models for population-level effects. We applied a suite of biochemical, histological, and behavioral end points related to visual structure and function and foraging behavior to evaluate effects of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) on swim-up rainbow trout. We detected a dose-dependent decrease in densities of retinal ganglion cells (RGC), key retinal neurons that link the eye with the brain. These changes resulted in corresponding deficits in visual/motor function including reductions in visual acuity and in scotopic and photopic thresholds due to TCDD. The loss of RGCs suggests an increase in convergence of synapses from photoreceptors to RGCs as a cellular mechanism for the visual deficits. Dose-dependent increases in immunohistochemical detection of CYP1A protein in the vasculature of the brain and eye choroid was proportional with decreased ganglion cell densities in the retina. TCDD-induced AHR-regulated effects on these tissues might be involved in the detected decrease in ganglion cell densities. Prey capture rate decreased after TCDD exposure only at the highest treatment groups evaluated. Collectively, these results show that TCDD causes biochemical and structural changes in the eye and brain of rainbow trout that are associated with behavioral deficits leading to decreased individual fitness.

  14. Embryonic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin impairs prey capture by zebrafish larvae.

    PubMed

    Chollett, Danielle; Perez, Kathryn E; King-Heiden, Tisha C

    2014-04-01

    As a ubiquitous, persistent environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has the potential to cause lethal deformities in larval fishes. Few studies have examined its impacts on larval growth and craniofacial development in conjunction with feeding capability. The authors used morphological and behavioral assessments to demonstrate that feeding capability of larvae is impaired even when craniofacial structures are not grossly malformed. Zebrafish embryos were exposed to 25 pg TCDD/mL, 50 pg TCDD/mL, or 100 pg TCDD/mL or <0.1% dimethyl sulfoxide for 1 h at 4 h postfertilization and then raised in clean water for 21 d or 90 d to assess craniofacial morphology, feeding capability, and long-term survival. The lower jaw was 5% smaller in 21-d larvae exposed to ≥ 50 pg TCDD/mL, and those larvae caught 10% fewer prey items; survival was reduced by 13% to 23%. The direct cause of TCDD's impacts on feeding capability is not known, but feeding success was correlated with growth, length of lower jaw, and survival. Since low larval mortality rates are key for recruitment, this suggests that exposure to concentrations of TCDD during embryonic development that do not initially cause mortality still has the potential to impact the recruitment success of feral fish. Furthermore, the present work provides additional evidence that behavioral end points are often more sensitive than morphological ones and should be included when assessing the sublethal toxicity of environmental contaminants.

  15. Rapid characterization of the 2015 Mw 7.8 Gorkha, Nepal, earthquake sequence and its seismotectonic context

    USGS Publications Warehouse

    Hayes, Gavin; Briggs, Richard; Barnhart, William D.; Yeck, William; McNamara, Daniel E.; Wald, David J.; Nealy, Jennifer; Benz, Harley M.; Gold, Ryan D.; Jaiswal, Kishor S.; Marano, Kristin; Earle, Paul; Hearne, Mike; Smoczyk, Gregory M.; Wald, Lisa A.; Samsonov, Sergey

    2015-01-01

    Earthquake response and related information products are important for placing recent seismic events into context and particularly for understanding the impact earthquakes can have on the regional community and its infrastructure. These tools are even more useful if they are available quickly, ahead of detailed information from the areas affected by such earthquakes. Here we provide an overview of the response activities and related information products generated and provided by the U.S. Geological Survey National Earthquake Information Center in association with the 2015 M 7.8 Gorkha, Nepal, earthquake. This group monitors global earthquakes 24  hrs/day and 7  days/week to provide rapid information on the location and size of recent events and to characterize the source properties, tectonic setting, and potential fatalities and economic losses associated with significant earthquakes. We present the timeline over which these products became available, discuss what they tell us about the seismotectonics of the Gorkha earthquake and its aftershocks, and examine how their information is used today, and might be used in the future, to help mitigate the impact of such natural disasters.

  16. Agent Orange Exposure and 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) in Human Milk.

    PubMed

    Scialli, Anthony R; Watkins, Deborah K; Ginevan, Michael E

    2015-06-01

    Agent Orange was sprayed in parts of southern Vietnam during the U.S.-Vietnam war and was a mixture of two chlorophenoxy herbicides. The mixture was contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). TCDD and other dioxins and furans are measurable in the milk of Vietnamese women. We explored whether the TCDD in milk from these women was from Agent Orange and whether lactational exposure can be a mode of transgenerational effects of TCDD from Agent Orange. A review of the world's literature on milk concentrations of polychlorinated compounds showed the presence of TCDD and other dioxins and furans in all countries that have been assessed. The congener profile of these chemicals, that is, the proportion of different congeners in the sample, can be used to assess the source of milk contamination. Measurements in most countries, including contemporary measurements in Vietnam, are consistent with non-Agent Orange exposure sources, including industrial activities and incineration of waste. Models and supporting human data suggest that TCDD from breastfeeding does not persist in a child past adolescence and that the adult body burden of TCDD is independent of whether the individual was breast- or bottle-fed as a child. These findings suggest that exposure to Agent Orange in Vietnam did not result in persistent transgenerational exposure through human milk. PMID:26195119

  17. Serum 2,3,7,8-tetrachlorodibenzo-p-dioxin levels in US Army Vietnam-era veterans

    SciTech Connect

    Not Available

    1988-09-02

    This study investigates whether military records can be used to identify US Army Vietnam veterans who were likely to be exposed to the herbicide Agent Orange. Serum levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a toxic contaminant in Agent Orange, were obtained for 646 ground combat troops who served in heavily sprayed areas of Vietnam and for 97 veterans who did not serve in Vietnam. The distributions of current TCDD levels in Vietnam and non-Vietnam veterans were nearly identical (mean in each group, approx. = 4 parts per trillion (ppt)). Only two men (both Vietnam veterans) had clearly elevated levels (> 20 ppt). Levels of TCDD did not tend to increase with greater likelihood of exposure to Agent Orange, as estimated from either military records of self-reported exposure. This study is consistent with other studies and suggests that most US Army ground troops who served in Vietnam were not heavily exposed to TCDD, except perhaps men whose jobs involved handling herbicides.

  18. An investigation of factors contributing to styrene and styrene-7,8-oxide exposures in the reinforced-plastics industry.

    PubMed

    Nylander-French, L A; Kupper, L L; Rappaport, S M

    1999-02-01

    During the manufacturing of reinforced plastics, large amounts of styrene and trace quantities of styrene-7,8-oxide (SO) are released. Since previous work suggests that inhalation of even small amounts of SO might be an important health risk, we investigated several possible factors contributing to styrene and SO exposure during the manufacture of reinforced plastics. Factors related to job type, worker and the type and quantity of styrene-containing resins were investigated using mixed-effects multiple linear regression models. Overall, SO exposure levels were positively correlated with styrene exposure levels. However, this correlation was statistically significant only among hand laminators who had the highest exposures to both styrene and SO. An important factor for predicting both styrene and SO concentrations was the type of resin used, while the quantity of resin consumed was predictive of styrene but not of SO exposure. Since So exposure appears to be associated with factors other than coexposure to styrene, more effort should be placed on investigating emissions of SO per se. The type of mixed-models regression analysis employed in this study can be used for clarifying the underlying patterns for exposures to styrene and SO as well as for evaluating preventive measures.

  19. Ground motions from the 2015 Mw 7.8 Gorkha, Nepal, earthquake constrained by a detailed assessment of macroseismic data

    USGS Publications Warehouse

    Martin, Stacey; Hough, Susan E.; Hung, Charleen

    2015-01-01

    To augment limited instrumental recordings of the Mw 7.8 Gorkha, Nepal, earthquake on 25 April 2015 (Nepali calendar: 12 Baisakh 2072, Bikram Samvat), we collected 3831 detailed media and first-person accounts of macroseismic effects that include sufficiently detailed information to assign intensities. The resulting intensity map reveals the distribution of shaking within and outside of Nepal, with the key result that shaking intensities throughout the near-field region only exceeded intensity 8 on the 1998 European Macroseismic Scale (EMS-98) in rare instances. Within the Kathmandu Valley, intensities were generally 6–7 EMS. This surprising (and fortunate) result can be explained by the nature of the mainshock ground motions, which were dominated by energy at periods significantly longer than the resonant periods of vernacular structures throughout the Kathmandu Valley. Outside of the Kathmandu Valley, intensities were also generally lower than 8 EMS, but the earthquake took a heavy toll on a number of remote villages, where many especially vulnerable masonry houses collapsed catastrophically in 7–8 EMS shaking. We further reconsider intensities from the 1833 earthquake sequence and conclude that it occurred on the same fault segment as the Gorkha earthquake.

  20. Suppression of humoral immune responses by 2,3,7,8-tetrachlorodibenzo-p-dioxin intercalated in smectite clay.

    PubMed

    Boyd, Stephen A; Johnston, Cliff T; Pinnavaia, Thomas J; Kaminski, Norbert E; Teppen, Brian J; Li, Hui; Khan, Bushra; Crawford, Robert B; Kovalova, Natalia; Kim, Seong-Su; Shao, Hua; Gu, Cheng; Kaplan, Barbara L F

    2011-12-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a highly toxic environmental contaminant found in soils and sediments. Because of its exceptionally low water solubility, this compound exists predominantly in the sorbed state in natural environments. Clay minerals, especially expandable smectite clays, are one of the major component geosorbents in soils and sediments that can function as an effective adsorbent for environmental dioxins, including TCDD. In this study, TCDD was intercalated in the smectite clay saponite by an incipient wetness method. The primary goal of this study was to intercalate TCDD in natural K-saponite clay and evaluate its immunotoxic effects in vivo. The relative bioavailability of TCDD was evaluated by comparing the metabolic activity of TCDD administered in the adsorbed state as an intercalate in saponite and freely dissolved in corn oil. This comparison revealed nearly identical TCDD-induced suppression of humoral immunity, a well-established and sensitive sequela, in a mammalian (mouse) model. This result suggests that TCDD adsorbed by clays is likely to be available for biouptake and biodistribution in mammals, consistent with previous observations of TCDD in livestock exposed to dioxin-contaminated ball clays that were used as feed additives. Adsorption of TCDD by clay minerals does not appear to mitigate risk associated with TCDD exposure substantially.

  1. 2,3,7,8-Tetrachlorodibenzo-p-dioxin exposure prevents cardiac valve formation in developing zebrafish.

    PubMed

    Mehta, Vatsal; Peterson, Richard E; Heideman, Warren

    2008-08-01

    Cardiovascular malformations are one of the most common congenital birth defects observed in humans. Defects in cardiac valves disrupt normal blood flow. Zebrafish are an outstanding experimental model for studying the effects that environmental contaminants have on developmental processes. Previous research has shown that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes blood regurgitation in the heart and reduces peripheral blood flow in embryonic zebrafish, suggesting some form of valve failure. To test this we used video microscopy to examine valve function and structure in developing zebrafish exposed to TCDD. TCDD exposure produced blood regurgitation at both the atrioventricular (AV) and bulboventricular (BV) junctions. In marked contrast to control embryos exposed to the vehicle dimethyl sulfoxide, embryos exposed to TCDD failed to form valve leaflets as the heart matured. In addition, whereas TCDD did not block initial formation of the bulbus arteriosus, we found that TCDD exposure prevented the normal growth and development of this portion of the outflow tract. TCDD altered the localization of endothelial cells at the AV and BV junctions and altered the localized expression of mRNAs bmp4 and notch1b normally associated with the nascent valves. Taken together, our results demonstrate that although TCDD does not prevent the initial specification of the presumptive valve locations, TCDD exposure produces severe alterations in valve development, leading to blood regurgitation and failing circulation in the developing zebrafish.

  2. Reproductive outcomes of mothers with potential exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Stockbauer, J.W.; Hoffman, R.E.; Schramm, W.F.; Edmonds, L.D.

    1988-08-01

    Animal laboratory studies have demonstrated that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has fetotoxic and teratogenic effects at low doses. TCDD contamination of soil in nine residential areas of eastern Missouri began in 1971 when several horse arenas and dirt roads were sprayed for dust control with a mixture that contained waste oil and dioxin. The authors conducted an epidemiologic investigation to determine if adverse human reproductive outcomes are associated with exposure to soil contaminated with dioxin. The authors attempted to identify all births during the period of January 1, 1972 through December 31, 1982 that had potential exposure to dioxin, based on proximity of the maternal address to a location of known TCDD contamination. This group totaled 410 births. A matched set of 820 unexposed births was selected as a comparison group after being matched for maternal age and race, year of birth, hospital of birth, and plurality. The exposed group had increased risk ratios for infant, fetal, and perinatal death; low birth weight; and several subcategories of birth defects. None of these increased risk ratios for the exposed group were statistically significant. These results do not provide evidence that TCDD exposure has a substantial impact on the reproductive outcomes investigated. If TCDD does produce effects on reproductive health, a larger study and/or better measures of exposure may be needed to discover them.

  3. Internal Gravity Wave Induced by the Queen Charlotte Event (27 October 2012, Mw 7.8): Airglow Observation and Modeling.

    NASA Astrophysics Data System (ADS)

    Occhipinti, G.; Bablet, A.; Makela, J. J.

    2015-12-01

    The detection of the tsunami related internal gravity waves (IGWtsuna) by airglow camera has been recently validated by observation (Makela et al., 2011) and modeling (Occhipinti et al., 2011) in the case of the Tohoku event (11 March 2011, Mw 9.0). The airglow is measuring the photon emission at 630 nm, indirectly linked to the plasma density of O2+ (Link & Cogger, 1988) and it is commonly used to detect transient event in the ionosphere (Kelley et al., 2002, Makela et al., 2009, Miller et al., 2009). The modeling of the IGWtsuna clearly reproduced the pattern of the airglow measurement observed over Hawaii and the comparison between the observation and the modeling allows to recognize the wave form and allow to explain the IGWtsuna arriving before the tsunami wavefront at the sea level (Occhipinti et al., 2011). Approaching the Hawaiian archipelagos the tsunami propagation is slowed down (reduction of the sea depth), instead, the IGWtsuna, propagating in the atmosphere/ionosphere, conserves its speed. In this work, we present the modeling of the new airglow observation following the Queen Charlotte event (27 October 2012, Mw 7.8) that has been recently detected, proving that the technique can be generalized for smaller events. Additionally, the effect of the wind on the IGWtsuna, already evocated in the past, is included in the modeling to better reproduce the airglow observations. All ref. here @ www.ipgp.fr/~ninto

  4. Transcriptional profiling of TLR-4/7/8-stimulated guinea pig splenocytes and whole blood by bDNA assay

    PubMed Central

    Ching, Lance K.; Mompoint, Farah; Guderian, Jeffrey A.; Picone, Alex; Orme, Ian M.; Coler, Rhea N.; Reed, Steven G.; Baldwin, Susan L.

    2011-01-01

    Toll-like receptor (TLR) agonists are currently being examined as adjuvants for vaccines, with several lead candidates now in licensed products or in late-stage clinical development. Guinea pigs are widely used for preclinical testing of drugs and vaccines; however, evaluation of TLR agonists in this model is hindered by the limited availability of immunological tools and reagents. In this study, we validated the use of a branched-chain DNA (bDNA) assay known as the QuantiGene Plex 2.0 Reagent System for measuring innate cytokine and chemokine mRNA levels following TLR stimulation of guinea pig cells. Gene expression for T-helper-1 (Th1) polarizing cytokines (TNF-α, IL-1β, IL-12) and chemokines (CXCL1, CCL2) was upregulated following ex vivo stimulation of guinea pig splenocytes and whole blood with TLR-4 or TLR-7/8 agonists. These data confirm the utility of the QuantiGene system both as an alternative to RT-PCR for measuring transcript levels and as a high-throughput screening tool for dissecting the immunological response to TLR stimulation in guinea pigs. Overall, the QuantiGene platform is reliable, reproducible, and sensitive. These agonists have the potential to be used as adjuvant components in vaccines against various pathogens. PMID:21839740

  5. Trends in 2,3,7,8-TCDD concentrations in fish tissues downstream of pulp mills bleaching with chlorine

    SciTech Connect

    Abbott, J.D.; Hinton, S.W.

    1996-07-01

    Field measurements of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) concentrations in fish tissues from riverine environments impacted by treated pulp and paper industry effluent in the US were analyzed. Data from 39 sites in 14 states across the four major US paper-making regions were assembled and analyzed to determine the annual change in lipid-normalized concentrations of TCDD in fish tissue. The results provide strong evidence of a nationwide trend of decreasing lipid-normalized TCDD concentrations in fish tissue, with 84% of the examined sites showing a decrease. While the paucity of data currently limits any conclusions regarding the statistical significance at individual sites, the overall median rate calculated indicates a 0.36 annual fractional decrease in lipid-normalized concentrations of TCDD in fish tissue (0.18 to 0.51, 95% confidence interval); the average annual fractional decrease was 0.35 (0.23 to 0.47, 95% confidence interval). Subdividing fish into benthic and nonbenthic categories resulted in rates which were not significantly different from one another for both the median and mean statistics.

  6. 2,3,7,8-tetrachlorodibenzo-p-dioxin induced autophagy in a bovine kidney cell line.

    PubMed

    Fiorito, Filomena; Ciarcia, Roberto; Granato, Giovanna Elvira; Marfe, Gabriella; Iovane, Valentina; Florio, Salvatore; De Martino, Luisa; Pagnini, Ugo

    2011-12-18

    The administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to a variety of cultured cells may alter their ability to proliferate and die. In a previous study we demonstrated that TCDD induced proliferation in Madin-Darby Bovine Kidney (MDBK) cells where no signs of apoptosis were observed, but herein, analysis of MDBK cell morphology, in a large number of exposed cells, revealed some alterations, as expanded cytoplasm, an increase of intercellular spaces and many pyknotic nuclei. Hence, the aim of the current study was to elucidate the influences of dioxin on cell proliferation and cell death. We found that dioxin increased proliferation, as well as, activated cell death with autophagy, as we detected by increased amount of LC3-II, an autophagosome marker. Furthermore, formation of acidic vesicular organelles was observed by fluorescence microscopy following staining with the lysosomotropic agent acridine orange. These results were accompanied by down-regulation of telomerase activity, bTERT and c-Myc. Key tumor-suppressor protein p53 and expression of cell cycle inhibitor p21Waf1/Cip1 were activated after TCDD exposure. These changes occurred with activation of ATM phosphorylation in the presence of a decrease in Mdm2 protein levels. Taken together, these results support the idea that TCDD in MDBK cells, may exert its action, in part, by enhancing cell proliferation, but also by modulating the incidence of induced cell death with autophagy.

  7. Evaluation of the peripheral nervous system among workers employed in the production of chemicals contaminated with 2,3,7. 8-tetra-chlorodibenzo-p-dioxin. Final report

    SciTech Connect

    Sweeney, M.H.; Fingerhut, M.A.; Connally, L.B.; Hornung, R.

    1990-07-01

    The long term effects on the peripheral nervous system in workers with past exposure to production products contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (1746016) (TCDD) were evaluated. The severity of the current neurologic status was compared to the levels of TCDD measured in the serum of study subjects. Workers who were employed at two chemical factories at which chemicals contaminated with TCDD were manufactured, and a group of unexposed referents were assessed in a cross sectional medical study in 1987 through 1988. Questionnaires were used to collect follow-up data. There were 281 workers and 260 referents who were interviewed and medically examined. Peripheral neuropathy was found in about 18% of workers and 19% of referents. Serum TCDD levels ranged from 2 to 3390 parts per trillion (ppt) for 272 workers and from 2 to 20ppt for 86 referents tested. No dose-response relationship was observed between TCDD levels present at the time of the examination and the occurrence of peripheral neuropathy in the previously exposed population. The authors conclude that exposure to TCDD caused no excess chronic peripheral neuropathy in a group of exposed workers compared to unexposed referents.

  8. Effect of tocopherol on biochemical blood parameters in pleuritis-induced rats treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin.

    PubMed

    Całkosiński, Ireneusz; Rosińczuk-Tonderys, Joanna; Bronowicka-Szydełko, Agnieszka; Dzierzba, Katarzyna; Bazan, Justyna; Dobrzyński, Maciej; Majda, Jacek; Gamian, Andrzej

    2015-06-01

    The aim of this study was to evaluate the effect of tocopherol on pleuritis-induced rats exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Rats were treated with a single TCDD dose of 5 μg/kg body weight (b.w.) and then for 3 weeks they were daily supplemented with tocopherol at a dose of 30 mg/kg b.w. The inflammation was initiated by intrapleural injection of a single dose of 1% carrageenin solution in a volume of 0.15 ml. Changes in biochemical blood parameters were measured three times at the 24th, 72nd and 120th hour of pleuritis and the blood was collected from 20 animals of each group of rats (group with the control inflammation; group treated with TCDD and with control inflammation; group treated with TCDD, supplemented with tocopherol and with the inflammation). The following biochemical parameters were measured: tumor necrosis factor (TNF), interleukin-1 (IL-1), IL-2, IL-4, IL-6, procollagen, telopeptide, fibrinogen, cholesterol, urea, creatinine, aspartate aminotransferase (AspAT) and alanine aminotransferase (AlAT). Daily supplementation of tocopherol caused significant changes in the level of TNF, IL-1, IL-4, IL-6, urea, creatinine, AspAT and AlAT. According to the results of these studies, we suggest that tocopherol supplementation in high doses could act as a protective treatment to improve liver metabolism.

  9. Cardiac toxicity by sublethal 2,3,7,8-tetrachlorodibenzo-p-dioxin correlates with its anti-proliferation effect on cardiomyocytes in zebrafish embryos.

    PubMed

    Chen, Jing

    2015-02-01

    The cardiac toxicity of zebrafish embryos in response to the lethal dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been well characterized. Dioxin contamination levels in nature are usually lower, however, and sublethal TCDD toxicity is less investigated. The present study found that the nonlethal doses of TCDD for 72-h-postfertilization (hpf) zebrafish embryos were 25 pg/mL and lower. For the present study, sublethal TCDD concentrations of 10 pg/mL and 25 pg/mL were selected, and their toxicity was then characterized. The results showed that embryos still exhibited acute and subchronic cardiac toxicity at these 2 dosages. The stroke volume and cardiac output of these embryos significantly declined early until 8 d postexposure. Embryos' heart size became smaller, and the hearts contained fewer cardiomyocytes per heart, with decreased cardiomyocyte proliferation. Apoptosis was not detected either in the TCDD-treated or the control hearts. Real-time polymerase chain reaction (PCR) revealed that the transcription of a battery of cell-cycle-related genes was suppressed within the sublethal TCDD-treated heart. In contrast, embryonic jaw development seemed not to be affected. The present study suggests that dioxin contamination, even at lower levels, might lead to cardiac toxicity in fish embryos. Such cardiac toxicity presents as disrupted normal heart function, originating from the anti-proliferative effect of sublethal TCDD on cardiomyocytes.

  10. Reproductive, neuroendocrine, and immune consequences of acute exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin in the Siberian hamster.

    PubMed

    Yellon, S M; Singh, D; Garrett, T M; Fagoaga, O R; Nehlsen-Cannarella, S L

    2000-08-01

    The present study tested the hypothesis that acute treatment with 2, 3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) impairs fertility, disrupts the nocturnal melatonin rhythm, and suppresses lymphocyte function. Adult Siberian hamsters administered 2 or 100 microg TCDD/kg body weight/0.2 ml sesame oil had a delayed latency to first litter and an increased adult mortality compared to hamsters given 0.1 microg/kg or vehicle. Within 75 days of TCDD treatment, full reproductive capabilities were achieved. Moreover, the nocturnal melatonin rhythm was not disrupted in adults administered TCDD or in their progeny. Lymphocyte activity varied with respect to time of day and treatment. Lymphocyte proliferation was enhanced at night irrespective of TCDD treatment; during the day, 2 wk after the 2-microg/kg treatment, blastogenesis was reduced compared to that in the 0.1-microg/kg group or in vehicle-treated controls. In contrast, TCDD did not affect the mixed lymphocyte reaction in response to allogeneic antigen when assessed at 2 and 20 wk post-treatment. Thus, findings indicate that TCDD produced acute effects on fertility, mortality, and systemic lymphocyte proliferation, but long-lasting effects on specific aspects of reproductive, neuroendocrine, and immune cell functions were not observed.

  11. Induction of benzo(a)pyrene metabolism by 2,3,7,8-tetrachlorodibenzo-p-dioxin in primary cultures of adult rat hepatocytes: regulation by vitamin A

    SciTech Connect

    Steward, A.R.

    1982-01-01

    In order to develop a cellular model for studying mechanisms of enzyme induction and the effects of this induction on xenobiotic metabolism and cytotoxicity, the induction of benzo(a)pyrene (BaP) metabolism by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was investigated in primary hepatocyte cultures prepared from adult male rats and maintained in chemically-defined medium containing hormones. A derepression of induction was observed during the first 3 days in culture. Addition of 0.8 to 2.0 ..mu..g/ml of retinol acetate (RA) prevented about half of the derepression of induction occurring between 36 and 60 h in culture. Horse serum (10%) also blocked up to half of the observed derepression. Serum, however, also led to a 40% reduction in the partitioning of (/sup 3/H)TCDD from the medium into the hepatocytes. The derepresion of MFO induction in primary adult hepatocyte cultures may occur partly as a result of a deficiency of retinol. RA is hypothesized to slow the time course of induction by reducing the rate of protein turnover. RA may also partially block the shift in the dose-response curve for induction by TCDD by maintaining the normal metabolic regulation of the cytosolic receptor for TCDD. Addition of a physiological level of RA to the culture medium may therefore help to maintain the hepatocytes at a level of genetic expression more nearly representative of the intact liver.

  12. Line-of-sight displacement from ALOS-2 interferometry: Mw 7.8 Gorkha Earthquake and Mw 7.3 aftershock

    NASA Astrophysics Data System (ADS)

    Lindsey, Eric O.; Natsuaki, Ryo; Xu, Xiaohua; Shimada, Masanobu; Hashimoto, Manabu; Melgar, Diego; Sandwell, David T.

    2015-08-01

    Interferometric synthetic aperture radar (InSAR) is a key tool for the analysis of displacement and stress changes caused by large crustal earthquakes, particularly in remote areas. A challenge for traditional InSAR has been its limited spatial and temporal coverage especially for very large events, whose dimensions exceed the typical swath width of 70-100 km. This problem is addressed by the ALOS-2 satellite, whose PALSAR-2 instrument operates in ScanSAR mode, enabling a repeat time of 2 weeks and a swath width of 350 km. Here we present InSAR line-of-sight displacement data from ALOS-2/PALSAR-2 observations covering the Mw 7.8 Gorkha, Nepal earthquake and its Mw 7.3 aftershock that were acquired within 1 week of each event. The data are made freely available and we encourage their use in models of the fault slip and associated stress changes. The Mw 7.3 aftershock not only extended the rupture area of the main shock toward the east but also left a 20 km gap where the fault has little or no coseismic slip. We estimate this unslipped fault patch has the potential to generate a Mw 6.9 event.

  13. Hypertension, Cardiac Hypertrophy, and Impaired Vascular Relaxation Induced by 2,3,7,8-Tetrachlorodibenzo-p-Dioxin are Associated with Increased Superoxide

    PubMed Central

    Kopf, Phillip G.; Huwe, Janice K.

    2009-01-01

    The mechanisms by which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases the incidence of human cardiovascular disease are not known. We investigated the degree to which cardiovascular disease develops in mice following subchronic TCDD exposure. Adult male C57BL/6 mice were dosed with vehicle or 300 ng TCDD/kg by oral gavage three times per week for 60 days. Blood pressure was recorded by radiotelemetry and aortic endothelial function was assessed by acetylcholine-induced vasorelaxation. Mean arterial pressure of TCDD-exposed mice was increased significantly by day 4 and between days 7–10, 25–35, and 45–60 with two periods of normalization on days 11–24 and days 36–39. Consistent with a prolonged period of systemic hypertension, heart weight was increased and was associated with concentric left ventricular hypertrophy. Significant increases in superoxide production also were observed in the kidney, heart, and aorta of TCDD-exposed mice. Furthermore, increased aortic superoxide resulted in endothelial dysfunction as demonstrated by significant impairment of acetylcholine-induced vasorelaxation in TCDD-exposed mice, which was restored by tempol, a superoxide dismutase (SOD) mimetic. Our model is the first to definitely demonstrate that sustained AhR activation by TCDD increases blood pressure and induces cardiac hypertrophy, which may be mediated, in part, by increased superoxide. PMID:18850075

  14. Comparison of serum levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin with indirect estimates of Agent Orange exposure among Vietnam veterans. Final report

    SciTech Connect

    Not Available

    1989-09-01

    The report tests the validity of several indirect methods for estimating the exposure of ground troops to Agent Orange in Vietnam during 1966-69. The study identified a sample of U.S. Army Vietnam veterans of that era and asked them to have blood drawn so that the level of 2,3,7,8-tetrachlorodibenzo-p- dioxin (TCDD) in serum could be measured. These veterans were selected from among those who served in 65 combat battalions in III Corps, a heavily sprayed part of Vietnam around Saigon. The men selected had all served only one tour in Vietnam and had been discharged with a pay grade of E1-E5, after having spent, on the average, over 300 days in Vietnam. The sample was chosen after the veterans had been stratified on likelihood of exposure (time and space proximity to recorded sprays) according to military records. For comparison, a sample of non-Vietnam U.S. Army veterans of the same era was also examined. The results show no meaningful association between TCDD levels and indirect estimate of Agent Orange exposure in Vietnam, with or without adjustment for other characteristics of the veterans, including age, race, body mass index, and self-reported civilian occupational and home herbicide exposure.

  15. Coseismic and postseismic deformation from the 14 November 2007 Mw 7.8 Tocopilla earthquake, as investigated by INSAR, and seismic observations

    NASA Astrophysics Data System (ADS)

    Motagh, M.; Schurr, B.; Hooper, A. J.; Anderssohn, J.; Moreno, M.; Wang, R.

    2010-12-01

    On November 14, 2007 a Mw=7.8 earthquake occurred in Tocopilla region of northern Chile, between the cities of Iquique and Antofagasta. Here we investigate coseismic surface deformation, fault slip distribution and postseismic deformation associated with this earthquake using satellite radar interferometry observations in combination with seismic data. The coseismic slip model is derived by the inversion of InSAR observations acquired by the Envisat satellite in Wide Swath (WS) and Image modes, with the fault geometry constrained by aftershocks. We infer an area of ~ 160 km by 50 km along the Nazca-South America convergent margin, between latitudes 22° S and 23.5° S, ruptured during the mainshock. The coseismic fault slip occurs between ~ 30 and 50 km depth, where we observe two high-slip regions (asperities) with the peak slip of ~ 1.5 m and 2.5 m beneath the earthquake epicenter and northeast of Mejillones Peninsula, respectively. We supplement this source parameter study with InSAR observations of postseismic deformation, obtained by time-series analysis of interferograms covering the entire length of the rupture area for several years before and after the earthquake.

  16. 2,3,7,8 tetrachlorodibenzodioxin in fish from the Pigeon river of Eastern Tennessee: Its toxicity and mutagenicity as revealed by the Ames Salmonella Assay

    SciTech Connect

    Blevins, R.D. )

    1990-04-01

    Levels of 2,3,7,8 tetrachlorodibenzodioxin (TCDD)were determined in both striated muscle (fillets) and whole body extracts of fish specimens harvested during a two year period (1987-1989) from the Pigeon River (between Hartford and Newport) of Eastern Tennessee. Whole body (wet weight) fish extract levels as high as 117 {mu}g/kg body weight and composite fish fillet (wet weight) extract levels as high 87 {mu}g/kg fillet weight were observed. Pure TCDD was found to be highly toxic to the Salmonella typhimurium strains TA97, TA98, TA100, TA102 and TA1535 at TCDD dosages which exceeded 825 ng/ml in the top agar of the Ames Salmonella assay. An 825 ng/ml TCDD dosage was not mutagenic to any of the tested Salmonella strains, (both with and without metabolic activation (S9) mix). However, when both acidic and alcohol fish extracts from the Pigeon River were tested for mutagenicity, several of the fish extracts were found to be mutagenic to Salmonella strains TA97, TA98, and TA100 (having mutagenic ratios which greatly exceeded the 2.5 {times} spontaneous ratio). These mutagenic extracts also demonstrated mutagenic dose-response curves. Other chemicals within the extracts as well as synergistic effects may account for the mutagenicity.

  17. Genetic polymorphisms in biotransformation enzymes for benzo[a]pyrene and related levels of benzo[a]pyrene-7,8-diol-9,10-epoxide-DNA adducts in Goeckerman therapy.

    PubMed

    Beranek, Martin; Fiala, Zdenek; Kremlacek, Jan; Andrys, Ctirad; Hamakova, Kvetoslava; Chmelarova, Marcela; Palicka, Vladimir; Borska, Lenka

    2016-07-25

    Goeckerman therapy (GT) for psoriasis combines the therapeutic effect of crude coal tar (CCT) and ultraviolet radiation (UVR). CCT contains polycyclic aromatic hydrocarbons, some of which can form DNA adducts that may induce mutations and contribute to carcinogenesis. The aim of our work was to evaluate the relationship between concentrations of benzo[a]pyrene-7,8-diol-9,10-epoxide-DNA adducts (BPDE-DNA adducts) and rs4646903 (CYP1A1 gene), rs1048943 (CYP1A1), rs1056836 (CYP1B1), rs1051740 (EPHX1), rs2234922 (EPHX1) and rs8175347 (UGT1A1) polymorphic sites, and GSTM1 null polymorphism in 46 patients with chronic stable plaque psoriasis who underwent GT. The level of BPDE-DNA adducts was determined using the OxiSelect BPDE-DNA Adduct ELISA Kit. Polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis (rs4646903, rs1048943, rs1051740, and rs2234922), fragment analysis (rs8175347), real-time PCR (rs1056836), and digital droplet PCR polymorphism (GSTM1) were used. CYP1B1*1/*1 wild-type subjects and CYP1B1*3/*1 heterozygotes for rs1056836 formed significantly higher amounts of BPDE-DNA adducts than CYP1B1*3/*3 homozygotes (p=0.031 and p=0.005, respectively). Regarding rs1051740, individuals with EPHX1*3/*1 heterozygosity revealed fewer adducts than EPHX1*1/*1 wild-type subjects (p=0.026). Our data suggest that CYP1B1/EPHX1 genotyping could help to predict the risk of DNA damage and to optimize doses of coal tar and UVR exposure in psoriatic patients in whom GT was applied. PMID:27188524

  18. High-Resolution Match Rate of 7/8 and 9/10 or Better for the Be The Match Unrelated Donor Registry.

    PubMed

    Buck, Kelly; Wadsworth, Kim; Setterholm, Michelle; Maiers, Martin; Confer, Dennis; Hartzman, Robert; Schmidt, Alexander; Yang, Soo Young; Dehn, Jason

    2016-04-01

    Estimation of the National Marrow Donor Program's Be The Match Registry 8/8 (HLA-A, -B, -C, and -DRB1) high-resolution (HR) unrelated donor (URD) match rate was determined in a prior study for each of the 4 most frequent patient race/ethnic groups in the United States: white (WH), Hispanic (HIS), Asian/Pacific Islander (API), and African American (AFA). For patients without an 8/8 HLA-matched URD, a 7/8 match, with a single allele or antigen mismatch, is often accepted by many transplant centers. A follow-up study was designed to determine the 7/8 or better match rate among the 4 major race/ethnic groups, using the same study cohort. Of previously HR tested URDs in the Be The Match Registry, 1344 were randomly selected and treated as pseudo-patients where HR testing was performed to identify a 7/8-matched URD; 98% of WH and over 80% of non-WH race/ethnic groups (HIS, API, and AFA) had at least a 7/8 match identified. In most cases after first testing to identify an 8/8-matched URD, a 7/8-matched URD was identified after typing just 1 URD. Extending criteria to identify a 9/10 match (included HLA-DQB1) showed the 9/10 absolute match rate decreased between 14% and 21% from the 7/8 match rate for the non-WH groups. This study provides a baseline 7/8 and 9/10 or better HLA match rate that can be further supplemented using the additional worldwide URD inventory. URD match rate information can equip centers in clinical planning and the education of patients seeking a life-saving therapy.

  19. Different requirements for proteolytic processing of bone morphogenetic protein 5/6/7/8 ligands in Drosophila melanogaster.

    PubMed

    Fritsch, Cornelia; Sawala, Annick; Harris, Robin; Maartens, Aidan; Sutcliffe, Catherine; Ashe, Hilary L; Ray, Robert P

    2012-02-17

    Bone morphogenetic proteins (BMPs) are synthesized as proproteins that undergo proteolytic processing by furin/subtilisin proprotein convertases to release the active ligand. Here we study processing of BMP5/6/7/8 proteins, including the Drosophila orthologs Glass Bottom Boat (Gbb) and Screw (Scw) and human BMP7. Gbb and Scw have three functional furin/subtilisin proprotein convertase cleavage sites; two between the prodomain and ligand domain, which we call the Main and Shadow sites, and one within the prodomain, which we call the Pro site. In Gbb each site can be cleaved independently, although efficient cleavage at the Shadow site requires cleavage at the Main site, and remarkably, none of the sites is essential for Gbb function. Rather, Gbb must be processed at either the Pro or Main site to produce a functional ligand. Like Gbb, the Pro and Main sites in Scw can be cleaved independently, but cleavage at the Shadow site is dependent on cleavage at the Main site. However, both Pro and Main sites are essential for Scw function. Thus, Gbb and Scw have different processing requirements. The BMP7 ligand rescues gbb mutants in Drosophila, but full-length BMP7 cannot, showing that functional differences in the prodomain limit the BMP7 activity in flies. Furthermore, unlike Gbb, cleavage-resistant BMP7, although non-functional in rescue assays, activates the downstream signaling cascade and thus retains some functionality. Our data show that cleavage requirements evolve rapidly, supporting the notion that changes in post-translational processing are used to create functional diversity between BMPs within and between species.

  20. Embryotoxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin in the ring-necked pheasant

    SciTech Connect

    Nosek, J.A.; Craven, S.R. . Dept. of Wildlife Ecology); Sullivan, J.R. . Wisconsin Dept. of Natural Resources); Gendron-Fitzpatrick, A. . Research Animal Veterinarian and Research Animal Resource Committee); Peterson, R.E. . School of Pharmacy and Environmental Toxicology Center)

    1993-07-01

    Fertilized eggs of ring-necked pheasants (Phasianus colchicus) were injected into the albumin or yolk with vehicle or graded doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), on day 0 of embryonic development and toxicity was assessed in 1-d-old hatchlings and 28-d-old chicks. The most sensitive effect of in ovo TCDD exposure was induction of hepatic ethoxyresorufin-O-deethylase (EROD) activity in 1-d-old hatchlings. The ED50 for this response was 312 pg TCDD/g egg. Embryo mortality was the most sensitive sign of toxicity. The TCDD dose that caused 50% mortality above control (LD50) when injected into the egg albumin or yolk was 1,354 and 2,182 pg TCDD/g egg, respectively. At egg TCDD doses up to and including 1,000 pg TCDD/g egg, no effect was detected in 1-d-old hatchlings and 28-d-old chicks in body growth, organ weights, carcass morphometrices, incidence of edema, or incidence of histological alterations in the liver, spleen, heart, Bursa of Fabricius, or thymus. Egg TCDD doses as high as 1,000 pg TCDD/g egg also had no effect on cardiac morphometrices or incidence of cardiac malformations in 1-d-old hatchlings, or on antibody-mediated immunity in 28-d-old chicks. The authors conclude that embryo mortality is the most sensitive sign of TCDD toxicity in the ring-necked pheasant following in ovo exposure.

  1. Long-term fate and bioavailability of sediment associated 2,3,7,8-tetrachlorodibenzofuran in littoral enclosures

    SciTech Connect

    Currie, R.S.; Fairchild, W.L.; Holoka, M.H.; Muir, D.C.G.

    2000-06-01

    the fate and bioavailability of 2,3,7,8-tetrachlorodibenzofuran (TCDF; 4,6-tritium labeled) was examined over a 3-year period in littoral enclosures in a small oligotrophic lake in the Experimental Lakes Area. Tetrachlorodibenzofuran was added as a single dose or as five small multiple additions over a 5-d period in a sediment slurry. Tetrachlorodibenzofuran was rapidly redistributed, mainly to bottom sediments reflecting removal on settling particles. Between 0 and 120 d. 80 to 90% of TCDF in the water column was associated with particles (>1 {micro}m). The highest concentration of TCDF in suspended particles was consistently observed in the smallest size fraction (0.22--1 {micro}m) at 326 to 464 d post treatment. Mode of addition had no effect on TCDF concentrations in water or surficial sediments or pore waters throughout the experiment. Mean TCDF concentrations in surficial sediment were 1.830 {+-} 1.180 pg/g whereas they averaged 1.260 {+-} 596 pg/g OC from 318 to 851 d post treatment. Increasing concentrations of TCDE in lower sediment layers at 952 d suggests that TCDF was either diffusing into the sediment or undergoing burial. Fugacity (f) calculations indicated that the TCDF in enclosures shifted from disequilibrium favoring the water column to a disequilibrium with respect to bottom sediments from day 21 onward. Initially, TCDF was more bioavailable to filtering and deposit feeders (mussels, Chironomidae, Hexagenia sp., and zooplankton) in enclosures receiving multiple additions; however, differences were rarely statistically significant. Concentrations of TCDF in all organisms were initially high, and they decreased in later sampling periods. Biota--sediment-accumulation factors (BSAFs) in mussels and crayfish were >1 in the early sampling periods, which reflected greater bioavailability of the added particle-borne TCDF. By 851 d, BSAFs had declined to 0.02 to 0.04, reflecting removal of TCDF from the water column and from surficial sediments.

  2. Transcriptional profiling of rat white adipose tissue response to 2,3,7,8-tetrachlorodibenzo-ρ-dioxin.

    PubMed

    Houlahan, Kathleen E; Prokopec, Stephenie D; Sun, Ren X; Moffat, Ivy D; Lindén, Jere; Lensu, Sanna; Okey, Allan B; Pohjanvirta, Raimo; Boutros, Paul C

    2015-10-15

    Polychlorinated dibenzodioxins are environmental contaminants commonly produced as a by-product of industrial processes. The most potent of these, 2,3,7,8-tetrachlorodibenzo-ρ-dioxin (TCDD), is highly lipophilic, leading to bioaccumulation. White adipose tissue (WAT) is a major site for energy storage, and is one of the organs in which TCDD accumulates. In laboratory animals, exposure to TCDD causes numerous metabolic abnormalities, including a wasting syndrome. We therefore investigated the molecular effects of TCDD exposure on WAT by profiling the transcriptomic response of WAT to 100μg/kg of TCDD at 1 or 4days in TCDD-sensitive Long-Evans (Turku/AB; L-E) rats. A comparative analysis was conducted simultaneously in identically treated TCDD-resistant Han/Wistar (Kuopio; H/W) rats one day after exposure to the same dose. We sought to identify transcriptomic changes coinciding with the onset of toxicity, while gaining additional insight into later responses. More transcriptional responses to TCDD were observed at 4days than at 1day post-exposure, suggesting WAT shows mostly secondary responses. Two classic AHR-regulated genes, Cyp1a1 and Nqo1, were significantly induced by TCDD in both strains, while several genes involved in the immune response, including Ms4a7 and F13a1 were altered in L-E rats alone. We compared genes affected by TCDD in rat WAT and human adipose cells, and observed little overlap. Interestingly, very few genes involved in lipid metabolism exhibited altered expression levels despite the pronounced lipid mobilization from peripheral fat pads by TCDD in L-E rats. Of these genes, the lipolysis-associated Lpin1 was induced slightly over 2-fold in L-E rat WAT on day 4.

  3. Synergistic effects of tributyltin and 2,3,7,8-tetrachlorodibenzo-p-dioxin on differentiating osteoblasts and osteoclasts

    SciTech Connect

    Koskela, Antti; Viluksela, Matti; Keinänen, Meeri; Tuukkanen, Juha; Korkalainen, Merja

    2012-09-01

    The purpose of this study was to examine the effects of the persistent and accumulative environmental pollutants tributyltin (TBT) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) individually and in combination on differentiating bone cells. TBT and TCDD are chemically distinct compounds with different mechanisms of toxicity, but they typically have the same sources of exposure and both have been shown to affect bone development at low exposure levels. Bone marrow stem cells were isolated from femurs and tibias of C57BL/6 J mice, differentiated in culture into osteoblasts or osteoclasts and exposed to 0.1–10 nM TBT, 0.01–1 nM TCDD or 10 nM TBT + 1 nM TCDD. In osteoblasts, the combined exposure to TBT and TCDD significantly decreased the mRNA expression of alkaline phosphatase and osteocalcin more than TBT or TCDD alone. PCR array showed different gene expression profiles for TBT and TCDD individually, and the combination evoked several additional alterations in gene expression. Expression of aryl hydrocarbon receptor repressor (AHRR) was increased by TCDD as expected, but simultaneous exposure to TBT prevented the increase thus potentially strengthening AHR-mediated effects of TCDD. The number of osteoclasts was reduced by TCDD alone and in combination with TBT, but TBT alone had no effect. However, the total area of resorbed bone was remarkably lower after combined exposure than after TBT or TCDD alone. In conclusion, very low concentrations of TBT and TCDD have synergistic deleterious effects on bone formation and additive effects on bone resorption. -- Highlights: ► Combined exposure to TCDD and TBT evoked a unique gene expression profile. ► Osteoblast differentiation was synergistically disturbed after combined exposure. ► Bone resorbing activity was additively decreased after combined exposure.

  4. Pulmonary bioavailability and fine particle enrichment of 2,3,7,8-tetrachlorodibenzo-p-dioxin in respirable soil particles

    SciTech Connect

    Nessel, C.S.; Amoruso, M.A.; Umbreit, T.H.; Meeker, R.J.; Gallo, M.A. )

    1992-08-01

    The pulmonary bioavailability of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and the enrichment of polychlorinated dioxins (PCDDs) and furans (PCDFs) in fine particles were evaluated to assess the implications that these factors have on risk and exposure assessments. Respirable subfractions of PCDD-contaminated soil from a former 2,4,5-trichlorophenoxyacetic acid manufacturing site were isolated by chemical dispersion and gravity sedimentation. Analysis of the subfractions revealed that there was a size-dependent enrichment of PCDDs and PCDFs, with smaller particles more highly contaminated. TCDD was enriched up to 33-fold as compared to unfractionated soil. Soil and laboratory-recontaminated gallium oxide, which served as the positive control, were administered by intratracheal instillation to female Sprague-Dawley rats. Animals were terminated up to 28 days following treatment and pulmonary bioavailability of TCDD was assessed by hepatic enzyme induction and TCDD concentration. Enzyme induction was dependent on the duration of exposure with up to 56 and 918% increases in cytochrome P450 and aryl hydrocarbon hydroxylase (AHH) activity, respectively, following exposure to PCDD-contaminated soil. There was no significant difference in AHH induction between animals which received contaminated soil and those treated with the positive control. Hepatic concentration of TCDD in soil-exposed rats was 115, 101, and 179% of positive controls at 1, 7, and 28 days post-treatment, suggesting that the soil or cocontaminants influenced retention of TCDD in the liver. These data indicate that the relative pulmonary bioavailability of TCDD on respirable soil particles is 100% as compared to laboratory-recontaminated gallium oxide and that PCDDs and PCDFs are highly enriched on respirable particles.

  5. The 2015 Mw 7.8 Gorkha Earthquake: Constraining the Geometry of the Main Himalayan Thrust from Space Geodesy

    NASA Astrophysics Data System (ADS)

    Jolivet, R.; Elliott, J. R.; González, P. J.; Avouac, J. P.; Hollingsworth, J.; Searle, M. P.; Stevens, V.

    2015-12-01

    The 2015 Mw 7.8 Gorkha earthquake ruptured a significant portion of the Main Himalayan Thrust (MHT), the main active structure responsible for the building of the Himalayas and for most destructive earthquakes in the past. Since this structure does not slip during the interseismic period, only indirect evidences allowed to infer its geometry at depth, a crucial point for numerous questions ranging from the long-term evolution of the mountain range to the dynamics of seismic ruptures. We use all available space-based geodetic data recording surface displacements during the 2015 Gorkha earthquake, including InSAR, GPS and optical imagery, to explore the space of possible geometric configurations of the MHT in the region of Kathmandu. From the Main Frontal Thrust (MFT), the surface expression of the MHT, our preferred fault geometry includes a steep (30°) ramp down to 5-km-depth, prolonged at depth by a shallow (5-8°) thrust extending 85 km north from the MFT where it steepens to form a 20-30° mid-crustal ramp, linking the seismic portion of the MHT to its deep, aseismic, root. This geometry is consistent with earlier geophysical measurements, such as electro-magneto-telluric data, the InDepth seismic reflection profile and the depth of relocated microseismicity. Moreover, the position of the mid-crustal ramp is consistent with the broad anticlinal shape of foliation north of the Kathmandu klippe. Such geometric configuration would suggest a structural control of the generation of high frequencies during the propagation of the rupture, as high-frequency radiators coincide with the up-dip edge of the mid-crustal ramp. Our proposed fault structure is meant to be used for further modeling of the earthquake cycle in the area, including the propagation of dynamic ruptures on a complex fault plane and the long-term behavior of the MHT, controlling the growth of the Himalayas.

  6. 7,8-Dihydroxyflavone reduces sleep during dark phase and suppresses orexin A but not orexin B in mice.

    PubMed

    Feng, Pingfu; Akladious, Afaf A; Hu, Yufen; Raslan, Yousef; Feng, James; Smith, Phillip J

    2015-10-01

    Brain-derived neurotrophic factor (BDNF) binds to Tropomyosin-receptor-kinase B (TrkB) receptors that regulate synaptic strength and plasticity in the mammalian nervous system. 7,8-Dihydroxyflavone (DHF) is a recently identified small molecule Trk B agonist that has been reported to ameliorate depression, attenuate the fear response, improve memory consolidation, and exert neuroprotective effects. Poor and disturbed sleep remains a symptom of major depressive disorder and most current antidepressants affect sleep. Therefore, we conducted sleep/wake recordings and concomitant measurement of brain orexins, endogenous peptides that suppress sleep, in mice for this study. Baseline polysomnograph recording was performed for 24 h followed by treatment with either 5 mg/kg of DHF or vehicle at the beginning of the dark phase. Animals were sacrificed the following day, one hour after the final treatment with DHF. Orexin A and B were quantified using ELISA and radioimmunoassay, respectively. Total sleep was significantly decreased in the DHF group, 4 h after drug administration in the dark phase, when compared with vehicle-treated animals. This difference was due to a significant decrease of non-rapid eye movement sleep, but not rapid eye movement sleep. DHF increased power of alpha and sigma bands but suppressed power of gamma band during sleep in dark phase. Interestingly, hypothalamic levels of orexin A were also significantly decreased in the DHF group (97 pg/mg) when compared with the vehicle-treated group (132 pg/mg). However, no significant differences of orexin B were observed between groups. Additionally, no change was found in immobility tests.

  7. Reduced Coenzyme Q10 Decreases Urinary 8-Oxo-7,8-Dihydro-2'-Deoxyguanosine Concentrations in Healthy Young Female Subjects.

    PubMed

    Ito, Kimiko; Watanabe, Chigusa; Nakamura, Akari; Oikawa-Tada, Saeko; Murata, Mariko

    2015-08-01

    It remains unclear whether dietary supplementation with coenzyme Q10 (CoQ10) provides beneficial effects for healthy individuals, especially young subjects. This study investigated the effects of dietary supplementation with CoQ10 on oxidative stress in healthy young females. We performed a placebo-controlled trial using a crossover design (n=28) with 100 mg/day CoQ10 in reduced form or placebo, each lasting 2 weeks with a 2-week interval. The urinary levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), a biomarker of oxidative DNA damage, were determined by high-performance liquid chromatography (HPLC) coupled to an electrochemical detector. Levels of malondialdehyde (MDA), a biomarker of lipid peroxidation, and antioxidant vitamin C in urine were also measured using a thiobarbituric acid-reactive substance method with a commercial kit and by the 2,4-dinitrophenylhydrazine method with HPLC, respectively. Urinary 8-oxodG levels during supplementation with reduced form of CoQ10 (median [first and third quartiles]: 1.76 [1.24-2.08] nmol/mmol creatinine) were significantly lower than those with placebo (2.00 [1.34-2.49] nmol/mmol creatinine, P=.031 by Student's paired t-test using the logarithmically transformed values). In contrast, the urinary levels of MDA and vitamin C were not significantly affected (P=.094 and P=.247 by Student's paired t-test, respectively). There was no evidence of any side effects. Supplementation with CoQ10 in the reduced form showed a slightly protective effect against oxidative DNA damage even in healthy young subjects.

  8. 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents in extracts of Baltic white-tailed sea eagles

    SciTech Connect

    Koistinen, J.; Giesy, J.P.; Koivusaari, J.; Nuuja, I.; Vuorinen, P.J.; Paasivirta, J.

    1997-07-01

    Concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin-(TCDD) equivalents were measured in extracts of Baltic white-tailed sea eagle tissues. Extracts of salmon, ringed seal, and grey seal were analyzed as other predatory species of the same area. Concentrations in eagle and seal tissues were greater than those in salmon. Concentrations of TCDD equivalents (TCDD-EQs) determined by the H4IIE bioassay were compared with toxic equivalents (TEQs) derived from instrumental chemical analyses in fractions containing polychlorinated dibenzo-P-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) or coplanar polychlorinated biphenyls (PCBs). Toxic equivalents were calculated by use of an additive model in which the product of the concentrations of instrumentally measured individual congeners were multiplied by their TCDD equivalency factors and were summed to give a total concentration of TEQs. The TCDD-EQs were compared with TEQs to develop a mass balance to determine whether all the TCDD-like activity was accounted for. The TEQs determined by chemical analyses for coplanar PCBs was 770 pg/g fw, and that of PCDD/PCDFs was 270 pg/g fw in this eagle. Thus, concentrations of TCDD-EQs were approx. 20% greater than those of TEQs. The true difference in activities is probably greater because of lower recoveries and infra-additivities among congeners in the bioassay. This indicates that there are compounds present in the extracts that can contribute to the total concentrations of TCDD-EQs in white-tailed sea eagle eggs to the no-observable-adverse-effect concentration, ranged from 7.3 to 141. This indicates that current concentrations of TCDD-EQs in these eggs are likely causing adverse effects in the Baltic populations of white-tailed sea eagles. This study indicated that the H4IIE bioassay is useful for monitoring the presence and biological activity of TCDD-like compounds in environmental samples like white-tailed sea eagles.

  9. Adrenocorticotropin (ACTH) and corticosterone secretion by perifused pituitary and adrenal glands from rodents exposed to 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD).

    PubMed

    Pitt, J A; Buckalew, A R; House, D E; Abbott, B D

    2000-10-26

    Although in utero maternal stress has been shown to have lasting effects on rodent offspring, fetal effects of chemically-induced alterations of the maternal hypothalamic-pituitary-adrenal axis (HPA) have not been well studied. This study examined the effects of in vivo 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure on pituitary-adrenal function in the male rat, pregnant female rat and pregnant female mouse. The secretion of adrenocorticotropin (ACTH) and corticosterone (CORT) in pituitary and adrenal glands, respectively, was assessed in ex vivo perifusion cultures. Male and pregnant female (gestation day 8) Sprague-Dawley rats were gavaged once with 10 microgram/kg TCDD, pregnant female mice once with 24 microgram/kg TCDD, and euthanized 10 days later. Hemi-pituitary (rat) or whole anterior pituitaries (mice) and right adrenal glands from the same animal were quartered, perifused under baseline and stimulated conditions. In both males and pregnant females, TCDD did not affect corticotropin releasing hormone (CRH)-stimulated ACTH secretion. Neither total pituitary ACTH nor plasma ACTH was altered in either sex or species by TCDD treatment. ACTH-stimulated CORT secretion was not affected by TCDD in either sex or species, and adrenal tissue and plasma CORT levels were unchanged in males and pregnant females by TCDD. However, the plasma ACTH:CORT ratio was decreased about 46% in male rats treated with TCDD. Plasma CORT levels were 23-fold higher and plasma ACTH levels were 1.5-fold higher in pregnant females than in male rats. In male versus female rats, adrenal CORT and anterior pituitary ACTH tissue levels were about 7.5- and 1.75-fold higher and ACTH, respectively. Female mouse adrenal tissue CORT was about 4-fold greater than female rat. The reduced plasma ACTH:CORT ratio in the male rat suggests that TCDD disturbs HPA function. Exposure of male rat to a 5-fold higher dose in earlier studies clearly demonstrated effects of TCDD on male rat HPA. The present

  10. Activation of muscular TrkB by its small molecular agonist 7,8-dihydroxyflavone sex-dependently regulates energy metabolism in diet-induced obese mice.

    PubMed

    Chan, Chi Bun; Tse, Margaret Chui Ling; Liu, Xia; Zhang, Shuai; Schmidt, Robin; Otten, Reed; Liu, Liegang; Ye, Keqiang

    2015-03-19

    Chronic activation of brain-derived neurotrophic factor (BDNF) receptor TrkB is a potential method to prevent development of obesity, but the short half-life and nonbioavailable nature of BDNF hampers validation of the hypothesis. We report here that activation of muscular TrkB by the BDNF mimetic, 7,8-dihydroxyflavone (7,8-DHF), is sufficient to protect the development of diet-induced obesity in female mice. Using in vitro and in vivo models, we found that 7,8-DHF treatment enhanced the expression of uncoupling protein 1 (UCP1) and AMP-activated protein kinase (AMPK) activity in skeletal muscle, which resulted in increased systemic energy expenditure, reduced adiposity, and improved insulin sensitivity in female mice fed a high-fat diet. This antiobesity activity of 7,8-DHF is muscular TrkB-dependent as 7,8-DHF cannot mitigate diet-induced obesity in female muscle-specific TrkB knockout mice. Hence, our data reveal that chronic activation of muscular TrkB is useful in alleviating obesity and its complications.

  11. Molecular characterization of mutation and comparison of mutation profiles in the hprt gene of Chinese hamster ovary cells treated with benzo[a]pyrene trans-7,8-diol-anti-9,10-epoxide, 1-nitrobenzol[a]pyrene trans-7,8-diol-anti-9,10-epoxide, and 3-nitrobenzol[a]pyrene trans-7,8-diol-anti-9,10-epoxide

    SciTech Connect

    Zhan, D.J.; Heflich, R.H.; Fu, P.P.

    1996-12-31

    Both 1- and 3-nitrobenzol[a] pyrene (nitro-BaP) are environmental contaminants, potent mutagens in Salmonella, and moderate mutagens in Chinese hamster ovary (CHO) cells. The mutagenicity of their oxidized metabolites, trans-7,8-dihydroxy-anti-9, 10-epoxy-7,8,9,10-tetrahydro-1-nitrobenzol[a]pyrene (1-nitro-BaP-DE) and trans-7,8-dihydroxy-anti-9, 10-epoxy-7,8,9,10-tetrahydro-3-nitrobenzo[a]pyrene (3-nitro-BaP-DE), together with trans-7,8-dihydroxy-anti-9,10-epoxy-7,8,9,10-tetrahydrobenzol[a]pyren (BaP-DE), was determined in CHO-K1 cells, and the resulting mutations at the hprt locus were characterized by polymerase chain reaction (PCR) amplification of reverse-transcribed hprt mRNA, followed by DNA sequence analysis. The mutant frequencies, in mutants/10{sup 6} clonable cells, at 30 and 100 ng/ml, were BaP-DE, 248 and 456; 1-nitro-BaP-DE, 68 and 260; 3-nitro-BaP-DE, 81 and 232, respectively. In general, the three diolepoxides exhibited similar mutational spectra: (1) 64% (23/36 sequenced mutants) of BaP-DE, 53% (19/36) of 1-nitro-BaP-DE, and 64% (23/36) of 3-nitro-BaP-DE mutants resulted from simple base pair substitution, with the predominant mutation being G{r_arrow}T transversion: (2) 90%, 100%, and 100% of mutations at G:C had the mutated dG on the nontranscribed DNA strand; and (3) about one quarter of the mutants produced by each mutagen had one or more PCR products with partial or complete exon deletions. 61 refs., 1 fig., 7 tabs.

  12. 3D-QSAR Study of 7,8-Dialkyl-1,3-diaminopyrrolo-[3,2-f] Quinazolines with Anticancer Activity as DHFR Inhibitors

    NASA Astrophysics Data System (ADS)

    Chen, Jin-can; Chen, Lan-mei; Liao, Si-yan; Qian, Li; Zheng, Kang-cheng

    2009-06-01

    A three-dimensional quantitative structure-activity relationship (3D-QSAR) study of a series of 7,8-dialkyl-1,3-diaminopyrrolo-[3,2-f] quinazolines with anticancer activity as dihydrofolate reductase (DHFR) inhibitors was carried out by using the comparative molecular field analysis (CoMFA), on the basis of our reported 2D-QSAR of these compounds. The established 3D-QSAR model has good quality of statistics and good prediction ability; the non cross-validation correlation coefficient and the cross-validation value of this model are 0.993 and 0.619, respectively, the F value is 193.4, and the standard deviation SD is 0.208. This model indicates that the steric field factor plays a much more important role than the electrostatic one, in satisfying agreement with the published 2D-QSAR model. However, the 3D-QSAR model offers visual images of the steric field and the electrostatic field. The 3D-QSAR study further suggests the following: to improve the activity, the substituent R' should be selected to be a group with an adaptive bulk like Et or i-Pr, and the substituent R should be selected to be a larger alkyl. In particular, based on our present 3D-QSAR as well as the published 2D-QSAR, the experimentally-proposed hydrophobic binding mechanism on the receptor-binding site of the DHFR can be further explained in theory. Therefore, the QSAR studies help to further understand the “hydrophobic binding" action mechanism of this kind of compounds, and to direct the molecular design of new drugs with higher activity.

  13. 2,3,7,8-Tetrachlorodibenzo-p-dioxin increases Bovine Herpesvirus type-1 (BHV-1) replication in Madin-Darby Bovine Kidney (MDBK) cells in vitro.

    PubMed

    Fiorito, F; Pagnini, U; De Martino, L; Montagnaro, S; Ciarcia, R; Florio, S; Pacilio, M; Fucito, A; Rossi, A; Iovane, G; Giordano, A

    2008-01-01

    Dioxin-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a common environmental toxin of current interest. In the last years, higher levels of TCDD than those permitted in UE [European Commission. 2002. European Commission Recommendation 2002/201/CE. Official Gazette, L 67/69] were detected in milk samples from cow, water buffalo, goat, and sheep raised on some areas of Campania Region (South Italy). Dioxin often causes immunosuppression and might render the animal liable to viral infections. In addition, viral infections are able to alter the pattern of dioxin distribution in different organs of the exposed animals. Bovine Herpesvirus type-1 (BHV-1) is a widespread pathogen, which causes infectious rhinotracheitis and infectious pustular vulvovaginitis in cattle. Herein, we have studied the effects of TCDD and BHV-1 infection, in Madin-Darby Bovine Kidney (MDBK) cells, alone as well as in association, so as cellular proliferation, apoptosis, and virus replication. We have observed an increase in cell viability of confluent monolayers at low TCDD concentrations. TCDD treated cells demonstrated increased viability compared to controls as evaluated by MTT test. TCDD exposure increased cell proliferation but induced no changes on apoptosis. Cells exposed to TCDD along with BHV-1 showed a dose-dependent increase in cytopathy, represented by ample syncytia formation with the elimination of the cellular sheets and increased viral titer. These results suggest that TCDD increases viral replication in MDBK cells while BHV-1 further decreases viability of TCDD exposed cells. Since very low concentrations (0.01 pg/ml) are sufficient to augment BHV-1 titer, TCDD may contribute to reactivate BHV-1 from latency, leading to recurrent disease and increase virus transmission. PMID:17516555

  14. 2,3,7,8-Tetrachlorodibenzo-p-dioxin increases Bovine Herpesvirus type-1 (BHV-1) replication in Madin-Darby Bovine Kidney (MDBK) cells in vitro.

    PubMed

    Fiorito, F; Pagnini, U; De Martino, L; Montagnaro, S; Ciarcia, R; Florio, S; Pacilio, M; Fucito, A; Rossi, A; Iovane, G; Giordano, A

    2008-01-01

    Dioxin-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a common environmental toxin of current interest. In the last years, higher levels of TCDD than those permitted in UE [European Commission. 2002. European Commission Recommendation 2002/201/CE. Official Gazette, L 67/69] were detected in milk samples from cow, water buffalo, goat, and sheep raised on some areas of Campania Region (South Italy). Dioxin often causes immunosuppression and might render the animal liable to viral infections. In addition, viral infections are able to alter the pattern of dioxin distribution in different organs of the exposed animals. Bovine Herpesvirus type-1 (BHV-1) is a widespread pathogen, which causes infectious rhinotracheitis and infectious pustular vulvovaginitis in cattle. Herein, we have studied the effects of TCDD and BHV-1 infection, in Madin-Darby Bovine Kidney (MDBK) cells, alone as well as in association, so as cellular proliferation, apoptosis, and virus replication. We have observed an increase in cell viability of confluent monolayers at low TCDD concentrations. TCDD treated cells demonstrated increased viability compared to controls as evaluated by MTT test. TCDD exposure increased cell proliferation but induced no changes on apoptosis. Cells exposed to TCDD along with BHV-1 showed a dose-dependent increase in cytopathy, represented by ample syncytia formation with the elimination of the cellular sheets and increased viral titer. These results suggest that TCDD increases viral replication in MDBK cells while BHV-1 further decreases viability of TCDD exposed cells. Since very low concentrations (0.01 pg/ml) are sufficient to augment BHV-1 titer, TCDD may contribute to reactivate BHV-1 from latency, leading to recurrent disease and increase virus transmission.

  15. Teratology of 2,3,7,8-tetrachlorodibenzo-p-dioxin in a complex environmental mixture from the Love Canal

    SciTech Connect

    Silkworth, J.B.; Cutler, D.S.; Antrim, L.; Houston, D.; Tumasonis, C.; Kaminsky, L.S. )

    1989-07-01

    The organic phase of a leachate (OPL) from the Love Canal chemical dump site contains more than 100 organic compounds including 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD). The teratogenic potential of OPL was determined in two inbred and one hybrid mouse strain which differ in their sensitivity to aromatic hydrocarbon (Ah) receptor-mediated toxicity. OPL was orally administered in corn oil on Days 6-15 of gestation to C57BL/6J mice (Ahb/Ahb) at doses of 0, 0.1, 0.3, 0.5, and 0.7 g kg-1 day-1 and to DBA/2J (Ahd/Ahd) females, which were mated with either DBA/2J or C57BL/6J males, at 0, 0.5, 1, and 2.0 g kg-1 day-1. In C57BL/6J mice, which express a high-affinity Ah receptor that avidly binds TCDD, the ED50's of OPL for cleft palate and hydronephrosis were 0.44 and 0.11 g OPL kg-1 day-1, respectively. Maternal mortality was 5% at the highest dose. In DBA/2J fetuses, which express a low-affinity receptor, neither treatment-related cleft palate nor hydronephrosis was induced by dose levels that caused 36% maternal mortality. In hybrid D2B6F1 fetuses, the incidence of cleft palate reached only 8% at 2 g OPL kg-1 day-1 but the ED50 for hydronephrosis was 0.76 g OPL kg-1 day-1. TCDD was similarly administered to pregnant C57BL/6J mice at 0, 0.5, 1, 2, and 4 micrograms kg-1 day-1 and to DBA/2J mice at 0, 0.5, 2, 4, and 8 micrograms kg-1 day-1. In C57BL/6J fetuses, the ED50's for cleft palate and hydronephrosis were 4.6 and 0.73 microgram TCDD kg-1 day-1, respectively. In DBA/2J fetuses the ED50's for cleft palate and hydronephrosis were 15.0 and 6.4 micrograms TCDD kg-1 day-1, respectively. Both the OPL and TCDD caused maternal hepatomegaly and thymic atrophy in all strains, but increased only C57BL/6J fetal weights. OPL decreased the number of fetuses per C57BL/6J dam at the two highest doses but there were no other reproductive effects in any of the groups.

  16. Immunotoxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin in a complex environmental mixture from the Love Canal.

    PubMed

    Silkworth, J B; Cutler, D S; Sack, G

    1989-02-01

    The organic phase of the leachate (OPL) from the Love Canal chemical dump site contains more than 100 organic compounds including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The immunotoxic potential of OPL was determined in two mouse strains which differ in their sensitivity to aromatic hydrocarbon (Ah) receptor-mediated toxicity. OPL was administered in corn oil in a single oral gavage to male BALB/cByJ (Ahb/Ahb) mice (0.5, 0.8, or 1.1 g/kg) and DBA/2J (Ahd/Ahd) mice (0.6, 0.9, or 1.3 g/kg). TCDD was similarly administered at 0.25, 1.0, 4.0, or 16.0 micrograms/kg. Two days later all mice were immunized with sheep erythrocytes (SRBC). The antibody response (PFC) and organ weights were evaluated 4 days later. OPL produced thymic atrophy and hepatomegaly in both strains at all dose levels. The PFC/spleen in BALB/cByJ mice was significantly reduced at the three doses to 34, 13, and 15%, respectively, of the control response. Serum anti-SRBC antibody levels and relative spleen weights were also reduced. The only immune effect in the DBA/2J mice was a decrease of the PFC/spleen to 58% of the control at the highest dose. TCDD decreased the relative thymus and spleen weights only in BALB/cByJ mice. However, TCDD produced hepatomegaly, a decrease in serum antibody, and a decrease in PFC/spleen in both BALB/cByJ and DBA/2J mice to 3 and 15%, respectively, at 16 micrograms/kg. Thus, the TCDD dose required to cause a 50% suppression (ED50) of PFC/spleen for the BALB/cByJ and DBA/2J strains was 1.84 and 3.89 micrograms/kg, respectively. The ED50 for OPL was 0.24 g/kg in BALB/cByJ mice. The TCDD concentration in the OPL was estimated to be 7.6 ppm, which agrees closely with the chemical analysis (3 ppm). The results suggest that the immunosuppression caused by OPL in BALB/cByJ mice was primarily due to TCDD, that the non-TCDD components of OPL diminished the TCDD immunotoxicity in the DBA/2J strain, and that the thymic atrophy and hepatomegaly were caused primarily by the non

  17. Immunotoxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin in a complex environmental mixture from the Love Canal

    SciTech Connect

    Silkworth, J.B.; Cutler, D.S.; Sack, G.

    1989-02-01

    The organic phase of the leachate (OPL) from the Love Canal chemical dump site contains more than 100 organic compounds including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The immunotoxic potential of OPL was determined in two mouse strains which differ in their sensitivity to aromatic hydrocarbon (Ah) receptor-mediated toxicity. OPL was administered in corn oil in a single oral gavage to male BALB/cByJ (Ahb/Ahb) mice (0.5, 0.8, or 1.1 g/kg) and DBA/2J (Ahd/Ahd) mice (0.6, 0.9, or 1.3 g/kg). TCDD was similarly administered at 0.25, 1.0, 4.0, or 16.0 micrograms/kg. Two days later all mice were immunized with sheep erythrocytes (SRBC). The antibody response (PFC) and organ weights were evaluated 4 days later. OPL produced thymic atrophy and hepatomegaly in both strains at all dose levels. The PFC/spleen in BALB/cByJ mice was significantly reduced at the three doses to 34, 13, and 15%, respectively, of the control response. Serum anti-SRBC antibody levels and relative spleen weights were also reduced. The only immune effect in the DBA/2J mice was a decrease of the PFC/spleen to 58% of the control at the highest dose. TCDD decreased the relative thymus and spleen weights only in BALB/cByJ mice. However, TCDD produced hepatomegaly, a decrease in serum antibody, and a decrease in PFC/spleen in both BALB/cByJ and DBA/2J mice to 3 and 15%, respectively, at 16 micrograms/kg. Thus, the TCDD dose required to cause a 50% suppression (ED50) of PFC/spleen for the BALB/cByJ and DBA/2J strains was 1.84 and 3.89 micrograms/kg, respectively. The ED50 for OPL was 0.24 g/kg in BALB/cByJ mice. The TCDD concentration in the OPL was estimated to be 7.6 ppm, which agrees closely with the chemical analysis (3 ppm).

  18. Toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to embryos of the fathead minnow (Pimephales promelas, Rafinesque)

    SciTech Connect

    Olivieri, C.; Cooper, K.

    1995-12-31

    This study correlates the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) residue and its toxicity to the fathead minnow embryo exposed to levels lower than the TCDD solubility range. The TCDD tissue doses in the embryo/larvae were related to gross lesions, delayed hatching, and death. A 7-day bioconcentration factor on a lipid basis (BCF{sub L}) was calculated. Embryos at the blatsula stage were exposed to [{sup 3}H] TCDD water concentrations (0.37, 0.59, 1.2, 2.83, and 10.1 6 ng/L), a nontreatment control and a solvent carrier control. Lesions were qualified as mild and severe based on their onset and their pathogenesis. Thus, mild lesions developed just prior to hatching or post-hatching at the fifth day of development. The severe lesions appeared at the third day of development. Embryos with tissue doses {le}2.46 {+-} 1.34 ng/g consistently developed mild lesions, while embryos with tissue doses {ge} 12.07 {+-} 4.91 ng/g developed severe lesions. The lowest observable adverse effect level was 0.04 {+-} 0.02 ng/g. The calculated 7-day ED{sub 50} was 0.14 ng/g. There was no delayed hatching at any of the concentrations tested. Embryo death occurred at a tissue concentration {ge}2.46 ng/g. The calculated 7-day LD{sub 50} was 25.71 ng/g. The relationship between the concentration of TCDD in the water (x = ng/L) and in the tissue dose (y = ng/g) fitted a linear curve y = {minus}1,143 + 3,792.5x, r{sup 2} = 0.98. The calculated BCF{sub L} (wet weight) was dose dependent. Embryos with tissue doses of 0.04 and 0.16 ng/g had BCF{sub L} of 2,700 and 3,325, respectively. Embryos with tissue doses of 2.46, 12.07, and 37.07 ng/g, had a BCF{sub L} of 104,225, 106,625 and 91,075, respectively.

  19. 2,3,7,8-tetrachlorodibenzo-p-dioxin: examination of biochemical effects involved in the proliferation and differentiation of XB cells

    SciTech Connect

    Knutson, J.C.; Poland, A.

    1984-10-01

    XB, a cell line derived form a mouse teratoma, differentiates into stratified squamous epithelium when incubated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). To examine the mediators of this response the effects produced by TCDD and those elicited by other compounds which stimulated epidermal proliferation and/or differentiation in mice were compared, XB/3T3 cultures keratinize when incubated with cholera toxin, epidermal growth factor (EGF), or TCDD , but not 12-0-tetradecanoylphorbol-13-acetate (TPA). Incubation of XB cells with TCDD for 48 hours produces an increase in thymidine incorporation, a response which is neither as large nor as rapid as that produced by cholera toxin, TPA, or EGF. Although both cholera toxin and TCDD stimulate differentiation and thymidine incorporation in XB/3T3 cultures, cholera toxin increases cAMP 30-fold in these cells, while TCDD does not affect cAMP accumulation. Inhibitors of arachidonic acid metabolism, which block epidermal proliferative responses to TPA in vivo, do not prevent the differentiation of XB cells in response to TCDD. In XB/3T3 cultures, TPA stimulates arachidonic acid release at all times tested (1,6, and 24 hours) and increases the incorporation of /sup 32/P/sub i/ into total phospholipids and phosphatidyl-choline after 3 hours. In contrast, D affects neither arachidonic acid release nor the turnover of phosphatidylinositol, or phosphatidylcholine at any of the times tested. Although biochemical effects which have been suggested as part of the mechanism of TCDD and produced by other epidermal proliferative compounds in XB cells were examined, no mediator of the TCDD-produced differentiation of XB/3T3 cultures was observed.

  20. Protective effects of (6R)-5,6,7,8-tetrahydro-l-biopterin on local ischemia/reperfusion-induced suppression of reactive hyperemia in rat gingiva

    PubMed Central

    Tanaka, Yusaku; Toyama, Toshizo; Wada-Takahashi, Satoko; Sasaki, Haruka; Miyamoto, Chihiro; Maehata, Yojiro; Yoshino, Fumihiko; Yoshida, Ayaka; Takahashi, Shun-suke; Watanabe, Kiyoko; Lee, Masaichi-Chang-il; Todoki, Kazuo; Hamada, Nobushiro

    2016-01-01

    We herein investigated the regulatory mechanism in the circulation responsible for rat gingival reactive hyperemia (RH) associated with ischemia/reperfusion (I/R). RH was analyzed using a laser Doppler flowmeter. RH and I/R were elicited by gingival compression and release with a laser Doppler probe. RH increased in a time-dependent manner when the duration of compression was between 30 s and 20 min. This increase was significantly suppressed by Nω-nitro-l-arginine-methyl-ester (l-NAME), 7-nitroindazole (7-NI), and 2,4-diamino-6-hydroxypyrimidine (DAHP). However, RH was markedly inhibited following 60 min of compression. This inhibition was significantly decreased by treatments with superoxide dismutase (SOD), (6R)-5,6,7,8-tetrahydro-l-biopterin (BH4), and sepiapterin. The luminescent intensity of superoxide anion (O2•−)-induced 2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo-[1,2-a] pyrazine-3-one (MCLA) was markedly decreased by SOD and BH4, but only slightly by sepiapterin. BH4 significantly decreased O2•− scavenging activity in a time-dependent manner. These results suggested that nitric oxide (NO) secreted by the nitrergic nerve played a role in regulating local circulation in rat gingiva. This NO-related regulation of local circulation was temporarily inhibited in the gingiva by the I/R treatment. The decrease observed in the production of NO, which was caused by suppression of NO synthase (NOS) activity subsequent to depletion of the NOS co-factor BH4 by O2•−, played a partial role in this inhibition. PMID:26798200

  1. Effects of chronic exposure to 2, 3, 7, 8,-tetrachlorodibenzo-p-dioxin on sister chromatid exchange levels in peripheral lymphocytes of the rhesus monkey

    SciTech Connect

    Lim, M.; Jacobson-Kram, D.; Bowman, R.E.; Williams, J.R.

    1987-01-01

    Frequencies of sister chromatid exchanges and chromosomal aberrations were examined in peripheral lymphocytes of Rhesus monkeys that had been fed a diet containing 25 parts per trillion 2,3,7,8-tetrachlorodibenzo-p-dioxin for a period of 4 years. When compared to non-exposed control animals, no significant differences were noted for either of these cytogenetic end points. In addition, there was not a significant difference in sister chromatid exchange response to a challenge dose of mitomycin C in cells from 2,3,7,8-tetrachlorodibenzo-p-dioxin exposed animals compared to controls. The results confirm the lack of genotoxic effects associated with 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure.

  2. Effect of dietary factors on mutagenesis, metabolism, and binding to DNA of benzo(a)pyrene and benzo(a)pyrene 7,8-dihydrodiol

    SciTech Connect

    Vance, R.E.

    1988-01-01

    Ellagic acid (EA), a naturally occurring plant phenol, at concentrations of 5 to 50 {mu}g/plate, inhibited rate liver S9 protein dependent benzo(a)pyrene (B(a)P)-induced mutagenesis in Salmonella typhimurium TA 100 by 30-81% and B(a)P 7,8-dihydrodiol (DHD)-induced mutagenesis by 29 to 75%. EA did not significantly affect the metabolism of B(a)P or B(a)P 7,8-DHD as determined by high performance liquid chromatographic analysis of the organosoluble fraction and by the quantification of water-soluble conjugates. At these concentrations EA inhibited the covalent binding of ({sup 3}H) B(a)P and ({sup 3}H) B(a)P 7,8-DHD metabolites to calf thymus DNA by 5 to 42% and 27 to 64%, respectively. Formation of benzo(a)pyrene 7,8-dihydrodiol-9,10-epoxide:deoxyguanosine (BPDE:dG) adducts was inhibited by 13 to 56% for B(a)P for B(a)P and 11 to 38% for B(a)P 7,8-DHD. These results suggest that the antimutagenic effect of EA and its inhibition of B(a)P and B(a)P 7,8-DHD metabolite-binding to DNA is not due to the inhibition of S9-mediated metabolism of these compounds. The inhibitory effect may be by previously described scavenging mechanism or by a DNA-affinity binding mechanism that prevents BPDE:DNA adduct formation.

  3. Love Canal Emergency Declaration Area habitability study. Volume 4. Soil assessment: 2,3,7,8-TCDD (tetrachlorodibenzo-p-dioxin). Final report

    SciTech Connect

    Not Available

    1988-03-01

    Environmental studies were conducted to provide data that could be used by the Commissioner of Health for the State of New York in determining whether the Emergency Declaration Area (EDA) surrounding the Love Canal hazardous-waste site is habitable. A soil assessment for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was conducted to determine whether the soil in the EDA contains 2,3,7,8-TCDD at levels above the level of concern set by the Centers for Disease Control: 1.0 ppb. Samples of surface soil were collected at 2,274 locations throughout the EDA.

  4. Decandrinin, an unprecedented C9-spiro-fused 7,8-seco-ent-abietane from the Godavari mangrove Ceriops decandra.

    PubMed

    Wang, Hui; Li, Min-Yi; Katele, Félix Zongwe; Satyanandamurty, Tirumani; Wu, Jun; Bringmann, Gerhard

    2014-01-01

    Decandrinin (1), an unprecedented C9-spiro-fused 7,8-seco-ent-abietane, was obtained from the bark of an Indian mangrove, Ceriops decandra, collected in the estuary of Godavari, Andhra Pradesh. The constitution and the relative configuration of 1 were determined by HRMS (ESI) and extensive NMR investigations, and the absolute configuration by circular dichroism (CD) and optical-rotatory dispersion (ORD) spectroscopy in combination with quantum-chemical calculations. Decandrinin is the first 7,8-seco-ent-abietane.

  5. Higher-order in time "quasi-unconditionally stable" ADI solvers for the compressible Navier-Stokes equations in 2D and 3D curvilinear domains

    NASA Astrophysics Data System (ADS)

    Bruno, Oscar P.; Cubillos, Max

    2016-02-01

    This paper introduces alternating-direction implicit (ADI) solvers of higher order of time-accuracy (orders two to six) for the compressible Navier-Stokes equations in two- and three-dimensional curvilinear domains. The higher-order accuracy in time results from 1) An application of the backward differentiation formulae time-stepping algorithm (BDF) in conjunction with 2) A BDF-like extrapolation technique for certain components of the nonlinear terms (which makes use of nonlinear solves unnecessary), as well as 3) A novel application of the Douglas-Gunn splitting (which greatly facilitates handling of boundary conditions while preserving higher-order accuracy in time). As suggested by our theoretical analysis of the algorithms for a variety of special cases, an extensive set of numerical experiments clearly indicate that all of the BDF-based ADI algorithms proposed in this paper are "quasi-unconditionally stable" in the following sense: each algorithm is stable for all couples (h , Δt)of spatial and temporal mesh sizes in a problem-dependent rectangular neighborhood of the form (0 ,Mh) × (0 ,Mt). In other words, for each fixed value of Δt below a certain threshold, the Navier-Stokes solvers presented in this paper are stable for arbitrarily small spatial mesh-sizes. The second-order formulation has further been rigorously shown to be unconditionally stable for linear hyperbolic and parabolic equations in two-dimensional space. Although implicit ADI solvers for the Navier-Stokes equations with nominal second-order of temporal accuracy have been proposed in the past, the algorithms presented in this paper are the first ADI-based Navier-Stokes solvers for which second-order or better accuracy has been verified in practice under non-trivial (non-periodic) boundary conditions.

  6. Real-time object recognition in multidimensional images based on joined extended structural tensor and higher-order tensor decomposition methods

    NASA Astrophysics Data System (ADS)

    Cyganek, Boguslaw; Smolka, Bogdan

    2015-02-01

    In this paper a system for real-time recognition of objects in multidimensional video signals is proposed. Object recognition is done by pattern projection into the tensor subspaces obtained from the factorization of the signal tensors representing the input signal. However, instead of taking only the intensity signal the novelty of this paper is first to build the Extended Structural Tensor representation from the intensity signal that conveys information on signal intensities, as well as on higher-order statistics of the input signals. This way the higher-order input pattern tensors are built from the training samples. Then, the tensor subspaces are built based on the Higher-Order Singular Value Decomposition of the prototype pattern tensors. Finally, recognition relies on measurements of the distance of a test pattern projected into the tensor subspaces obtained from the training tensors. Due to high-dimensionality of the input data, tensor based methods require high memory and computational resources. However, recent achievements in the technology of the multi-core microprocessors and graphic cards allows real-time operation of the multidimensional methods as is shown and analyzed in this paper based on real examples of object detection in digital images.

  7. Younger age at initiation of the human papillomavirus (HPV) vaccination series is associated with higher rates of on-time completion.

    PubMed

    St Sauver, Jennifer L; Rutten, Lila J Finney; Ebbert, Jon O; Jacobson, Debra J; McGree, Michaela E; Jacobson, Robert M

    2016-08-01

    Vaccination rates for human papillomavirus (HPV) have remained disappointingly low. It is critical to identify methods to increase on-time vaccine series completion rates (before 13 or 15years). To determine whether younger age (9 to 10years of age) at HPV vaccine series initiation was associated with improved on-time completion rates compared to initiation at 11 to 12years, we examined the prevalence of on-time HPV vaccine series completion rates from August 2006 through December 2012 in a large, population-based cohort of children and adolescents (aged 9.5 to 27years) residing in Olmsted County, MN on December 31, 2012 (n=36,223). We compared age at vaccine initiation between individuals who successfully completed both 2 and 3 doses of the vaccination series on-time (before age 13.5 or 15.0years) using multivariate logistic regression. On-time completion of both 2 and 3 doses of the vaccine series by age 13.5 or 15.0years was significantly associated with initiation at 9 to 10years as compared to 11 to 12years after adjusting for sex, race, insurance status, frequent health care visits, and year of first vaccination (all p<.01). Interventions focused on beginning the vaccination series at 9 to 10years of age may result in higher rates of timely series completion.

  8. Teratology of 2,3,7,8-tetrachlorodibenzo-p-dioxin in a complex environmental mixture from the love canal.

    PubMed

    Silkworth, J B; Cutler, D S; Antrim, L; Houston, D; Tumasonis, C; Kaminsky, L S

    1989-07-01

    The organic phase of a leachate (OPL) from the Love Canal chemical dump site contains more than 100 organic compounds including 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD). The teratogenic potential of OPL was determined in two inbred and one hybrid mouse strain which differ in their sensitivity to aromatic hydrocarbon (Ah) receptor-mediated toxicity. OPL was orally administered in corn oil on Days 6-15 of gestation to C57BL/6J mice (Ahb/Ahb) at doses of 0, 0.1, 0.3, 0.5, and 0.7 g kg-1 day-1 and to DBA/2J (Ahd/Ahd) females, which were mated with either DBA/2J or C57BL/6J males, at 0, 0.5, 1, and 2.0 g kg-1 day-1. In C57BL/6J mice, which express a high-affinity Ah receptor that avidly binds TCDD, the ED50's of OPL for cleft palate and hydronephrosis were 0.44 and 0.11 g OPL kg-1 day-1, respectively. Maternal mortality was 5% at the highest dose. In DBA/2J fetuses, which express a low-affinity receptor, neither treatment-related cleft palate nor hydronephrosis was induced by dose levels that caused 36% maternal mortality. In hybrid D2B6F1 fetuses, the incidence of cleft palate reached only 8% at 2 g OPL kg-1 day-1 but the ED50 for hydronephrosis was 0.76 g OPL kg-1 day-1. TCDD was similarly administered to pregnant C57BL/6J mice at 0, 0.5, 1, 2, and 4 micrograms kg-1 day-1 and to DBA/2J mice at 0, 0.5, 2, 4, and 8 micrograms kg-1 day-1. In C57BL/6J fetuses, the ED50's for cleft palate and hydronephrosis were 4.6 and 0.73 microgram TCDD kg-1 day-1, respectively. In DBA/2J fetuses the ED50's for cleft palate and hydronephrosis were 15.0 and 6.4 micrograms TCDD kg-1 day-1, respectively. Both the OPL and TCDD caused maternal hepatomegaly and thymic atrophy in all strains, but increased only C57BL/6J fetal weights. OPL decreased the number of fetuses per C57BL/6J dam at the two highest doses but there were no other reproductive effects in any of the groups. It was concluded that the OPL is teratogenic and that hydronephrosis is a sensitive measure of TCDD toxicity in a

  9. Post Earthquake Investigation Of The Mw7.8 Haida Gwaii, Canada, Rupture Area And Constraints On Earthquake Source Models

    NASA Astrophysics Data System (ADS)

    Haeussler, P. J.; Witter, R. C.; Wang, K.

    2013-12-01

    The October 28, 2012 Mw 7.8 Haida Gwaii, British Columbia, earthquake was the second largest historical earthquake recorded in Canada. Earthquake seismology and GPS geodesy shows this was an underthrusting event, in agreement with prior studies that indicated oblique underthrusting of the Haida Gwaii by the Pacific plate. Coseismic deformation is poorly constrained by geodesy, with only six GPS sites and two tide gauge stations anywhere near the rupture area. In order to better constrain the coseismic deformation, we measured the upper limit of sessile intertidal organisms at 26 sites relative to sea level. We dominantly measured the positions of bladder weed (fucus distichus - 617 observations) and the common acorn barnacle (Balanus balanoides - 686 observations). Physical conditions control the upper limit of sessile intertidal organisms, so we tried to find the quietest water conditions, with steep, but not overhanging faces, where slosh from wave motion was minimized. We focused on the western side of the islands as rupture models indicated that the greatest displacement was there. However, we were also looking for calm water sites in bays located as close as possible to the often tumultuous Pacific Ocean. In addition, we made 322 measurements of sea level that will be used to develop a precise tidal model and to evaluate the position of the organisms with respect to a common sea level datum. We anticipate the resolution of the method will be about 20-30 cm. The sites were focused on the western side of the Haida Gwaii from Wells Bay on the south up to Otard Bay to the north, with 5 transects across strike. We also collected data at the town of Masset, which lies outside of the deformation zone of the earthquake. We observed dried and desiccated bands of fucus and barnacles at two sites on the western coast of southern Moresby Island (Gowgia Bay and Wells Bay). Gowgia Bay had the strongest evidence of uplift with fucus that was dried out and apparently dead. A

  10. Teratology of 2,3,7,8-tetrachlorodibenzo-p-dioxin in a complex environmental mixture from the love canal.

    PubMed

    Silkworth, J B; Cutler, D S; Antrim, L; Houston, D; Tumasonis, C; Kaminsky, L S

    1989-07-01

    The organic phase of a leachate (OPL) from the Love Canal chemical dump site contains more than 100 organic compounds including 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD). The teratogenic potential of OPL was determined in two inbred and one hybrid mouse strain which differ in their sensitivity to aromatic hydrocarbon (Ah) receptor-mediated toxicity. OPL was orally administered in corn oil on Days 6-15 of gestation to C57BL/6J mice (Ahb/Ahb) at doses of 0, 0.1, 0.3, 0.5, and 0.7 g kg-1 day-1 and to DBA/2J (Ahd/Ahd) females, which were mated with either DBA/2J or C57BL/6J males, at 0, 0.5, 1, and 2.0 g kg-1 day-1. In C57BL/6J mice, which express a high-affinity Ah receptor that avidly binds TCDD, the ED50's of OPL for cleft palate and hydronephrosis were 0.44 and 0.11 g OPL kg-1 day-1, respectively. Maternal mortality was 5% at the highest dose. In DBA/2J fetuses, which express a low-affinity receptor, neither treatment-related cleft palate nor hydronephrosis was induced by dose levels that caused 36% maternal mortality. In hybrid D2B6F1 fetuses, the incidence of cleft palate reached only 8% at 2 g OPL kg-1 day-1 but the ED50 for hydronephrosis was 0.76 g OPL kg-1 day-1. TCDD was similarly administered to pregnant C57BL/6J mice at 0, 0.5, 1, 2, and 4 micrograms kg-1 day-1 and to DBA/2J mice at 0, 0.5, 2, 4, and 8 micrograms kg-1 day-1. In C57BL/6J fetuses, the ED50's for cleft palate and hydronephrosis were 4.6 and 0.73 microgram TCDD kg-1 day-1, respectively. In DBA/2J fetuses the ED50's for cleft palate and hydronephrosis were 15.0 and 6.4 micrograms TCDD kg-1 day-1, respectively. Both the OPL and TCDD caused maternal hepatomegaly and thymic atrophy in all strains, but increased only C57BL/6J fetal weights. OPL decreased the number of fetuses per C57BL/6J dam at the two highest doses but there were no other reproductive effects in any of the groups. It was concluded that the OPL is teratogenic and that hydronephrosis is a sensitive measure of TCDD toxicity in a

  11. In utero/lactational and adult exposures to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) show differential effects on craniofacial development and growth in rats.

    PubMed

    Sholts, Sabrina B; Korkalainen, Merja; Simanainen, Ulla; Miettinen, Hanna M; Håkansson, Helen; Viluksela, Matti

    2015-11-01

    In a previous study of female Han/Wistar (H/W) and Long-Evans (L-E) rats, we found that adult exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was associated with size decreases in the cranium and especially the face. In this study we compared these crania to those from male and female Sprague-Dawley (S-D) rats with in utero/lactational exposure to TCDD, using morphometric variables of size, shape, and fluctuating asymmetry to quantify the effects of dose on craniofacial development and growth. At the highest levels of exposure, in utero/lactational and adult TCDD exposures both resulted in small but significant reductions in facial size parameters (i.e., 3-5%) in only females and minor effects on facial shape in both sexes. The shape effects of in utero/lactational exposure were most significant at the sutural intersections, whereas adult exposure to TCDD corresponded to dose-dependent changes of decreasing facial length and vault breadth. Fluctuating asymmetry in general explained a relatively small amount of shape variation compared with other effects, and only increased significantly in female L-E rats with high levels of adult exposure to TCDD. These results indicate that TCDD-related changes in cranial development and growth in rats can vary with the timing and duration of exposure, and with sex. Further investigations of other dioxin-like compounds and animal species will broaden our understanding of how chemicals exposure can influence the development and growth of the mammalian skeleton.

  12. Human and Methodological Sources of Variability in the Measurement of Urinary 8-Oxo-7,8-dihydro-2′-deoxyguanosine

    PubMed Central

    Møller, Peter; Henriksen, Trine; Mistry, Vilas; Koppen, Gudrun; Rossner, Pavel; Sram, Radim J.; Weimann, Allan; Poulsen, Henrik E.; Nataf, Robert; Andreoli, Roberta; Manini, Paola; Marczylo, Tim; Lam, Patricia; Evans, Mark D.; Kasai, Hiroshi; Kawai, Kazuaki; Li, Yun-Shan; Sakai, Kazuo; Singh, Rajinder; Teichert, Friederike; Farmer, Peter B.; Rozalski, Rafal; Gackowski, Daniel; Siomek, Agnieszka; Saez, Guillermo T.; Cerda, Concha; Broberg, Karin; Lindh, Christian; Hossain, Mohammad Bakhtiar; Haghdoost, Siamak; Hu, Chiung-Wen; Chao, Mu-Rong; Wu, Kuen-Yuh; Orhan, Hilmi; Senduran, Nilufer; Smith, Raymond J.; Santella, Regina M.; Su, Yali; Cortez, Czarina; Yeh, Susan; Olinski, Ryszard; Loft, Steffen

    2013-01-01

    Abstract Aims: Urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) is a widely used biomarker of oxidative stress. However, variability between chromatographic and ELISA methods hampers interpretation of data, and this variability may increase should urine composition differ between individuals, leading to assay interference. Furthermore, optimal urine sampling conditions are not well defined. We performed inter-laboratory comparisons of 8-oxodG measurement between mass spectrometric-, electrochemical- and ELISA-based methods, using common within-technique calibrants to analyze 8-oxodG-spiked phosphate-buffered saline and urine samples. We also investigated human subject- and sample collection-related variables, as potential sources of variability. Results: Chromatographic assays showed high agreement across urines from different subjects, whereas ELISAs showed far more inter-laboratory variation and generally overestimated levels, compared to the chromatographic assays. Excretion rates in timed ‘spot’ samples showed strong correlations with 24 h excretion (the ‘gold’ standard) of urinary 8-oxodG (rp 0.67–0.90), although the associations were weaker for 8-oxodG adjusted for creatinine or specific gravity (SG). The within-individual excretion of 8-oxodG varied only moderately between days (CV 17% for 24 h excretion and 20% for first void, creatinine-corrected samples). Innovation: This is the first comprehensive study of both human and methodological factors influencing 8-oxodG measurement, providing key information for future studies with this important biomarker. Conclusion: ELISA variability is greater than chromatographic assay variability, and cannot determine absolute levels of 8-oxodG. Use of standardized calibrants greatly improves intra-technique agreement and, for the chromatographic assays, importantly allows integration of results for pooled analyses. If 24 h samples are not feasible, creatinine- or SG-adjusted first morning samples

  13. Line of Sight Displacement from ALOS-2 ScanSAR Interferometry: Burst Alignment and the Mw 7.8 Gorkha, Nepal Earthquake

    NASA Astrophysics Data System (ADS)

    Lindsey, E. O.; Natsuaki, R.; Xu, X.; Shimada, M.; Hashimoto, M.; Melgar, D.; Sandwell, D. T.

    2015-12-01

    A challenge for traditional InSAR has been its limited spatial and temporal coverage especially for very large events, whose dimensions exceed the typical swath width of 70 - 100 km. This problem is addressed by the ScanSAR mode of the ALOS-2 satellite's PALSAR-2 instrument, which enables a repeat time of 2 weeks and a swath width of 350 km. We present InSAR line-of-sight displacement observations from ScanSAR images acquired within one week of both the Mw 7.8 Gorkha, Nepal earthquake and its Mw 7.3 aftershock. The Mw 7.3 aftershock extended the rupture area of the main shock toward the east, but also left a 20 km gap where the fault has little or no co-seismic slip. We estimate this un-slipped fault patch has the potential to generate a Mw 6.9 event. Our results are freely available online at http://topex.ucsd.edu/nepal, and we encourage their use in models of the fault slip and associated stress changes. We also discuss burst alignment of the PALSAR-2 ScanSAR images and show that while images acquired after February 8, 2015 are burst-aligned with each other, prior to that date the alignment drifted according to a sinusoidal function. We present an accurate formula for determining the burst offset between two scenes; the date ranges for burst alignment with post-February 8 images are July 22 - July 31, November 8 - November 17, December 16 - December 23 2014, and January 20 - January 29 2015.

  14. Temporal changes in purity and specific activity of tritium-labeled 2,3,7,8-tetrachlorodibenzo-p-dioxin: Radiopurity model for toxicology

    SciTech Connect

    Fernandez, J.D.; Cook, P.M.; Butterworth, B.C.; Bradbury, S.P.

    1999-10-15

    The specific activity (S) and radiopurity (R) of tritium labeled 2,3,7,8-tetrachlorodibenzo-p-dioxin, [{sub 3}H]TCDD, were measured by gas chromatography/mass spectrometry (GC/MS) while attempting to accurately characterized TCDD doses received by invertebrates, fish, and fish embryos during several toxicology studies conducted over a 3 year period. The [{sub 3}H]TCDD sample was found to consist of six TCDD analogues involving hydrogen, deuterium, and tritium substitution at the 1,6-dibenzo-p-dioxin carbon positions and a complex mixture of impurities (with and without tritium labels). Planar aromatic impurities were identified a tolyl-TCDD adducts and appeared to result from the decay of {sub 3}H radiolabels to produce TCDD carbocations which reacted with the solvent, toluene. Formation of TriCDD and tolyl-TriCDDs, from both TCDD and tolyl-TCDDs, probably resulted from radiolysis-induced loss of a chlorine to form TriCDD free radicals which reacted with toluene. The measurement of S for [{sub 3}H]TCDD by GC/MS was accurate and precise ({+-}3%) because relative, rather than absolute, amounts of the analogues were determined. Changes in S over time were accurately modeled as a function of the conversion of each [{sub 3}H]TCDD analogue to a solvent-TCDD analogue at a rate determined by {sub 3}H loss due to decay. Storage, purification, and use of tritiated chemicals for toxicology studies requires consideration of the {sub 3}H decay-related phenomena. For example, hydroxylated TCDD is an expected decay reaction product of [{sub 3}H]TCDD in tissues and may be misidentified as a metabolite.

  15. Aromatic hydrocarbon responsiveness-receptor agonists generated from indole-3-carbinol in vitro and in vivo: Comparisons with 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Bjeldanes, L.F.; Jinyoung Kim; Grose, K.R.; Bartholomew, J.C. ); Bradfield, C.A. )

    1991-11-01

    Indole-3-carbinol (I3C) is a secondary plant metabolite produced in vegetables of the Brassica genus, including cabbage, cauliflower, and brussels sprouts. I3C is both an anti-initiator and a promoter of carcinogenesis. Consumption of I3C by humans and rodents can lead to marked increases in activities of cytochrome P-450-dependent monooxygenases and in a variety of phase II drug-metabolizing enzymes. The authors have reported previously that the enzyme-inducing activity of I3C is mediated through a mechanism requiring exposure of the compound to the low-pH environment of the stomach. They report here the aromatic hydrocarbon responsiveness-receptor K{sub d} values (22 nM-90 nM), determined with C57BL/6J mouse liver cytosol and the in vitro- and in vivo-molar yields of the major acid condensation products of I3C. They also show that indolo (3,2-b)carbazole (ICZ) is produced form I3C in yields on the order of 0.01% in vitro and, after oral intubation, in vivo. ICZ has a K{sub d} of 190 pM for aromatic hydrocarbon responsiveness-receptor binding and an EC{sub 50} of 269 nM for induction of cytochrome P4501A1, as measured by ethoxyresorufin O-deethylase activity in murine hepatoma Hepa 1c1c7 cells. The binding affinity of ICZ is only a factor of 3.7 {times} 10{sup {minus}2} lower than that of the highly toxic environmental contaminant and cancer promoter 2,3,7,8-tetrachlorodibenzo-p-dioxin. ICZ and related condensation products appear responsible for the enzyme-inducing effects of dietary I3C.

  16. Identification of Reference Proteins for Western Blot Analyses in Mouse Model Systems of 2,3,7,8-Tetrachlorodibenzo-P-Dioxin (TCDD) Toxicity

    PubMed Central

    Prokopec, Stephenie D.; Watson, John D.; Pohjanvirta, Raimo; Boutros, Paul C.

    2014-01-01

    Western blotting is a well-established, inexpensive and accurate way of measuring protein content. Because of technical variation between wells, normalization is required for valid interpretation of results across multiple samples. Typically this involves the use of one or more endogenous controls to adjust the measured levels of experimental molecules. Although some endogenous controls are widely used, validation is required for each experimental system. This is critical when studying transcriptional-modulators, such as toxicants like 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).To address this issue, we examined hepatic tissue from 192 mice representing 47 unique combinations of strain, sex, Ahr-genotype, TCDD dose and treatment time. We examined 7 candidate reference proteins in each animal and assessed consistency of protein abundance through: 1) TCDD-induced fold-difference in protein content from basal levels, 2) inter- and intra- animal stability, and 3) the ability of each candidate to reduce instability of the other candidates. Univariate analyses identified HPRT as the most stable protein. Multivariate analysis indicated that stability generally increased with the number of proteins used, but gains from using >3 proteins were small. Lastly, by comparing these new data to our previous studies of mRNA controls on the same animals, we were able to show that the ideal mRNA and protein control-genes are distinct, and use of only 2–3 proteins provides strong stability, unlike in mRNA studies in the same cohort, where larger control-gene batteries were needed. PMID:25329058

  17. Augmented atherogenesis in ApoE-null mice co-exposed to polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Shan, Qiuli; Wang, Jing; Huang, Fengchen; Lv, Xiaowen; Ma, Min; Du, Yuguo

    2014-04-15

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls (PCBs) are persistent organic pollutants found as complex mixtures in the environment throughout the world. Therefore, humans are ubiquitously and simultaneously exposed to TCDD and PCBs. TCDD and PCBs alone have been linked to atherosclerosis. However, the effects of interactions or synergism between TCDD and PCBs on atherogenesis are unknown. We investigated the possible enhanced atherogenesis by co-exposure to TCDD and PCBs and the potential mechanism(s) involved in this enhancement. Male ApoE{sup −/−} mice were exposed to TCDD (15 μg/kg) and Aroclor1254 (55 mg/kg, a representative mixture of PCBs) alone or in combination by intraperitoneal injection four times over six weeks of duration. Our results showed that mice exposed to TCDD alone, but not Aroclor1254 alone, developed atherosclerotic lesions. Moreover, we found that atherosclerotic disease was exacerbated to the greatest extent in mice co-exposed to TCDD and Aroclor1254. The enhanced lesions correlated with several pro-atherogenic changes, including a marked increase in the accumulation of the platelet-derived chemokine PF4, and the expression of the proinflammatory cytokine MCP-1 and the critical immunity gene-RIG-I. Our data demonstrated that co-exposure to TCDD and Aroclor1254 markedly enhanced atherogenesis in ApoE{sup −/−} mice. Significantly, our observations suggest that combined exposure to TCDD and PCBs may be a greater cardiovascular health risk than previously anticipated from individual studies. - Highlights: • Augmented atherogenesis was found in ApoE{sup −/−} mice co-exposed to Aroclor1254 and TCDD. • Enhanced expression of PF4, MCP-1 and RIG-I correlated with augmented lesions. • POPs combination may be a greater cardiovascular health risk than individual POPs.

  18. Polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents in tree swallows from the upper Hudson River, New York State, USA

    USGS Publications Warehouse

    Secord, Anne L.; McCarty, John P.; Echols, Kathy R.; Meadows, John C.; Gale, Robert W.; Tillitt, Donald E.

    1999-01-01

    The upper Hudson River of New York State, USA, is contaminated with polychlorinated biphenyls (PCBs) as a result of industrial discharges throughout the latter half of this century. In 1994 and 1995, we monitored the transfer of PCBs from aquatic sediments to a terrestrial wildlife community using the tree swallow (Tachycineta bicolor) as a model organism. Tree swallow eggs and nestlings were collected at four colonies established along a 40-km stretch of the upper Hudson River watershed. Samples were analyzed for total PCBs and PCB congeners, including non-ortho- and mono-ortho-substituted PCBs. Mean concentrations of PCBs in tree swallow eggs and nestlings ranged from 721 to 62,200 ng/g and were as much as 15 times greater than PCB concentrations in tree swallow eggs and nestlings collected from PCB-contaminated areas within the Great Lakes ecosystem. The corresponding 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) calculated using avian toxic equivalency factors ranged from 410 to 25,400 pg/g. Concentrations of PCB congener 77 (3,39,4,49-tetrachlorobiphenyl) were extremely elevated and were major contributors to the calculated TEQs. Homologue pattern comparisons between Hudson River and Saginaw River (Michigan, USA) ecosystems supported the hypothesis that a consistent Hudson River PCB source was the major contributor to PCBs in Hudson River tree swallows. The high concentrations of PCBs in Hudson River sediments and resultant concentrations observed in tree swallows were indicative of a potential elevated risk to these and other wildlife linked to the aquatic food web of the Hudson River ecosystem.

  19. Polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents in tree swallows from the upper Hudson River, New York State, USA

    USGS Publications Warehouse

    Secord, A.L.; McCarty, J.P.; Echols, K.R.; Meadows, J.C.; Gale, R.W.; Tillitt, D.E.

    1999-01-01

    The upper Hudson River of New York State, USA, is contaminated with polychlorinated biphenyls (PCBs) as a result of industrial discharges throughout the latter half of this century. In 1994 and 1995, we monitored the transfer of PCBs from aquatic sediments to a terrestrial wildlife community using the tree swallow (Tachycineta bicolor) as a model organism. Tree swallow eggs and nestlings were collected at four colonies established along a 40-km stretch of the upper Hudson River watershed. Samples were analyzed for total PCBs and PCB congeners, including non-ortho- and mono- ortho-substituted PCBs. Mean concentrations of PCBs in tree swallow eggs and nestlings ranged from 721 to 62,200 ng/g and were as much as 15 times greater than PCB concentrations in tree swallow eggs and nestlings collected from PCB-contaminated areas within the Great Lakes ecosystem. The corresponding 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) calculated using avian toxic equivalency factors ranged from 410 to 25,400 pg/g. Concentrations of PCB congener 77 (3,3',4,4'-tetrachlorobiphenyl) were extremely elevated and were major contributors to the calculated TEQs. Homologue pattern comparisons between Hudson River and Saginaw River (Michigan, USA) ecosystems supported the hypothesis that a consistent Hudson River PCB source was the major contributor to PCBs in Hudson River tree swallows. The high concentrations of PCBs in Hudson River sediments and resultant concentrations observed in tree swallows were indicative of a potential elevated risk to these and other wildlife linked to the aquatic food web of the Hudson River ecosystem.

  20. Comparative toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to seven freshwater fish species during early life-stage development

    SciTech Connect

    Elonen, G.E.; Spehar, R.L.; Holcombe, G.W.; Johnson, R.D.; Fernandez, J.D.; Erickson, R.J.; Tietge, J.E.; Cook, P.M.

    1998-03-01

    The toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to fathead minnow (Pimephales promelas), channel catfish (Ictalurus punctatus), lake herring (Coregonus artedii), medaka (Oryzias latipes), white sucker (Catastomus commersoni), northern pike (Esox lucius), and zebrafish (Danio danio) were observed during early life-stage development after waterborne exposure of fertilized eggs. Species sensitivity based on TCDD-C{sub egg} (TCDD concentration in eggs) was determined by effects observed over a 32-d period for all species except lake herring in which a 100-d period was used. Signs of TCDD toxicity, including edema, hemorrhaging, and craniofacial malformations were essentially identical to those observed in salmonids following TCDD egg exposure and preceded or accompanied mortality most often during the period from hatch through swim-up. The no-observed-effect concentrations and lowest-observed-effect concentrations, based on significant decreases in survival and growth as compared to the controls, ranged from 175 and 270 pg/g for lake herring to 424 and 2,000 pg/g for zebrafish, respectively. Shapes of concentration-response curves, expressed as TCDD-C{sub egg} versus percent mortality, were similar for all species and were consistently steep suggesting that the mechanism of action of TCDD is the same among these species. The LC{sub egg}50s ranged from 539 pg/g for the fathead minnow to 2,610 pg/g for zebrafish. Comparisons of LC{sub egg}50s indicate that the tested species were approximately 8 to 38 times less sensitive to TCDD than lake trout, the most sensitive species evaluated to date. When LC{sub egg}50s are normalized to the fraction lipid in eggs (LC{sub egg,f}50s), the risk to early life stage survival for the species tested ranges from 16- to 180-fold less than for lake trout.

  1. Polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents in tree swallows from the upper Hudson River, New York State, USA

    SciTech Connect

    Secord, A.L.; McCarty, J.P.; Echols, K.R.; Meadows, J.C.; Gale, R.W.; Tillitt, D.E.

    1999-11-01

    The upper Hudson River of New York State, USA, is contaminated with polychlorinated biphenyls (PCBs) as a result of industrial discharges throughout the latter half of this century. In 1994 and 1995, the authors monitored the transfer of PCBs from aquatic sediments to a terrestrial wildlife community using the tree swallow (Tachycineta bicolor) as a model organism. Tree swallow eggs and nestlings were collected at four colonies established along a 40-km stretch of the upper Hudson River watershed. Samples were analyzed for total PCBs and PCB congeners, including non-ortho- and mono-ortho-substituted PCBs. Mean concentrations of PCBs in tree swallow eggs and nestlings ranged from 721 to 62,200 ng/g and were as much as 15 times greater than PCB concentrations in tree swallow eggs and nestlings collected from PCB-contaminated areas within the Great Lakes ecosystem. The corresponding 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) calculated using avian toxic equivalency factors ranged from 410 to 25,400 pg/g. Concentrations of PCB congener 77 (3.3{prime}, 4,4{prime}-tetrachlorobiphenyl) were extremely elevated and were major contributors to the calculated TEQs. Homologue pattern comparisons between Hudson River and Saginaw River (Michigan, USA) ecosystems supported the hypothesis that a consistent Hudson River PCB source was the major contributor to PCBs in Hudson River tree swallows. The high concentrations of PCBs in Hudson River sediments and resultant concentrations observed in tree swallows were indicative of a potential elevated risk to these and other wildlife linked to the aquatic food web of the Hudson River ecosystem.

  2. Interactive effects of n-TiO2 and 2,3,7,8-TCDD on the marine bivalve Mytilus galloprovincialis.

    PubMed

    Canesi, Laura; Frenzilli, Giada; Balbi, Teresa; Bernardeschi, Margherita; Ciacci, Caterina; Corsolini, Simonetta; Della Torre, Camilla; Fabbri, Rita; Faleri, Claudia; Focardi, Silvano; Guidi, Patrizia; Kočan, Anton; Marcomini, Antonio; Mariottini, Michela; Nigro, Marco; Pozo-Gallardo, Karla; Rocco, Lucia; Scarcelli, Vittoria; Smerilli, Arianna; Corsi, Ilaria

    2014-08-01

    Despite the growing concern over the potential biological impact of nanoparticles (NPs) in the aquatic environment, little is known about their interactions with other pollutants. The bivalve Mytilus sp, largely utilized as a sentinel for marine contamination, has been shown to represent a significant target for different types of NP, including n-TiO2, one of the most widespread in use. In this work, the possible interactive effects of n-TiO2 and 2,3,7,8-TCDD, chosen as models of NP and organic contaminant, respectively, were investigated in Mytilus galloprovincialis. In vitro experiments with n-TiO2 and TCDD, alone and in combination, were carried out in different conditions (concentrations and times of exposure), depending on the target (hemocytes, gill cells and biopsies) and the endpoint measured. Mussels were also exposed in vivo to n-TiO2 (100 μg L(-1)) or to TCDD (0.25 μg L(-1)), alone and in combination, for 96 h. A wide range of biomarkers, from molecular to tissue level, were measured: lysosomal membrane stability and phagocytosis in hemocytes, ATP-binding cassette efflux transporters in gills (gene transcription and efflux activity), several biomarkers of genotoxicity in gill and digestive cells (DNA damage, random amplified polymorphic DNA-RAPD changes), lysosomal biomarkers and transcription of selected genes in the digestive gland. The results demonstrate that n-TiO2 and TCDD can exert synergistic or antagonistic effects, depending on experimental condition, cell/tissue and type of measured response. Some of these interactions may result from a significant increase in TCDD accumulation in whole mussel organisms in the presence of n-TiO2, indicating a Trojan horse effect. The results represent the most extensive data obtained so far on the sub-lethal effects of NPs and organic contaminants in aquatic organisms. Moreover, these data extend the knowledge on the molecular and cellular targets of NPs in bivalves.

  3. 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD) DISRUPTS EARLY MORPHOGENETIC EVENTS THAT FORM THE LOWER REPRODUCTIVE TRACT IN FEMALE RAT FETUSES

    EPA Science Inventory

    In female rats, in utero exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during critical periods of organogenesis causes a permanent thread of tissue across the vaginal opening, which consists of a core of mesenchyme surrounded by keratinized epithelia. The objective of t...

  4. PERSISTENT ABNORMALITIES IN THE RAT MAMMARY GLAND FOLLOWING GESTATIONAL AND LACTATIONAL EXPOSURE TO 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD)

    EPA Science Inventory

    SUMMARY

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) exposure during gestation has revealed reproductive anomalies in rat offspring, including inconclusive reports of stunted mammary development in females (Brown et al., 1998, Lewis et al., 2001). The current studies wer...

  5. Training to improve manual control in 7-8 and 10-12 year old children: Training eliminates performance differences between ages.

    PubMed

    Snapp-Childs, Winona; Fath, Aaron J; Watson, Carol A; Flatters, Ian; Mon-Williams, Mark; Bingham, Geoffrey P

    2015-10-01

    Many children have difficulty producing movements well enough to improve in perceptuo-motor learning. We have developed a training method that supports active movement generation to allow improvement in a 3D tracing task requiring good compliance control. We previously tested 7-8 year old children who exhibited poor performance and performance differences before training. After training, performance was significantly improved and performance differences were eliminated. According to the Dynamic Systems Theory of development, appropriate support can enable younger children to acquire the ability to perform like older children. In the present study, we compared 7-8 and 10-12 year old school children and predicted that younger children would show reduced performance that was nonetheless amenable to training. Indeed, the pre-training performance of the 7-8 year olds was worse than that of the 10-12 year olds, but post-training performance was equally good for both groups. This was similar to previous results found using this training method for children with DCD and age-matched typically developing children. We also found in a previous study of 7-8 year old school children that training in the 3D tracing task transferred to a 2D drawing task. We now found similar transfer for the 10-12 year olds.

  6. Cytochrome P4501A1 is Required for Vascular Dysfunction and Hypertension Induced by 2,3,7,8-Tetrachlorodibenzo-p-dioxin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    National Health and Nutrition Examination Survey data show an association between hypertension and exposure to dioxin-like halogenated aromatic hydrocarbons (HAH). Further, chronic exposure of mice to the prototypical HAH, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), induces reactive oxygen species (...

  7. In utero and lactational 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure: Effects on fetal and adult cardiac gene expression and adult cardiac and renal morphology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mouse heart is a target of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during fetal development, and microarray analysis demonstrates significant changes in expression of cardiac genes involved in extracellular matrix (ECM) remodeling. We tested the hypothesis that developmental TCDD exposure wo...

  8. Hypertension, Cardiac Hypertrophy, and Impaired Vascular Relaxation Induced by 2,3,7,8-Tetrachlorodibenzo-p-Dioxin are Associated with Increased Superoxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mechanisms by which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases the incidence of human cardiovascular disease are not known. We investigated the degree to which cardiovascular disease develops in mice following subchronic TCDD exposure. Adult male C57BL/6 mice were dosed with vehicle o...

  9. UTILIZATION OF A PBPK MODEL TO PREDICT THE DISTRIBUTION OF 2, 3, 7-8 TETRACHLORODIBENZO-P-DIOXIN (TCDD) IN HUMANS DURING CRITICAL WINDOWS OF DEVELOPMENT

    EPA Science Inventory

    Utilization of A PBPK model to predict the distribution of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) in humans during critical windows of development.
    C Emond1, MJ DeVito2 and LS Birnbaum2
    1National Research Council, US EPA, ORD, NHEERL, (ETD, PK), RTP, NC, 27711, USA 2 US...

  10. TERATOGENICITY OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD) IN MICE LACKING THE EXPRESSION OF EGF AND/OR TGFALPHA

    EPA Science Inventory

    Abstract
    2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure produces hydronephrosis and cleft palate in mice. These responses are correlated with disruption of expression of epidermal growth factor (EGF) receptor ligands, primarily EGF and transforming growth factor-alpha ...

  11. SEVESO WOMEN'S HEALTH STUDY: A STUDY OF THE EFFECTS OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN ON REPRODUCTIVE HEALTH. (R824761)

    EPA Science Inventory

    Abstract

    Although reproductive effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure have been reported in numerous investigations of animals, studies of this association in humans are limited. In 1976, an explosion in Seveso, Italy exposed the surround...

  12. Exposure and Human Health Reassessment of 2,3,7,8-Tetrachlorodibenzo-P-Dioxin (Tcdd) and Related Compounds: Science Advisory Board (External Review Draft) (2000)

    EPA Science Inventory

    Dioxin Reassessment, SAB Review Draft

    The U.S. Environmental Protection Agency's (EPA) is progressing toward completion of its comprehensive reassessment of dioxin science entitled, "Exposure and Human Health Reassessment of 2,3,7,8-Tetrachlorodibe...

  13. Defining the Borders of Dose Addition: Mixture Effects of 2,3,7,8-Tetrachlorodibenzo-p-dioxin and Dibutyl phthalate on Male Rat Reproductive Tract Development

    EPA Science Inventory

    In utero exposure to either dibutyl phthalate (DBP) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) disrupts male rat reproductive tract differentiation. However, they act via different modes of toxicity and induce distinct postnatal phenotypes. DBP exposure decreases anogenital di...

  14. Lack of contribution of covalent benzo[a]pyrene-7,8-quinone-DNA adducts in benzo[a]pyrene-induced mouse lung tumorigenesis

    EPA Science Inventory

    Benzo[a]pyrene (B[a]P) is a potent human and rodent lung carcinogen. This activity has been ascribed in part to the formation of anti-trans-B[a]P-7,8-diol-9,10-epoxide (BPDE)-DNA adducts. Other carcinogenic mechanisms have been proposed: 1.] The induction of apurinic sites from r...

  15. TOXICITY OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN TO EARLY LIFE STAGE BROOK TROUT (SALVELINUS FONTINALIS) FOLLOWING PARTENTAL DIETARY EXPOSURE

    EPA Science Inventory

    The toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to the early life stages of F1 generation brook trout (Salvelinus fontinalis) was determined, when dosed by maternal transfer.Effects were compared across six treatments, including a control.The experimental groups, based...

  16. Close-up of 7/8' gold-plated liquid oxygen post plug copy form; photos beginning with 99PD are only

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Engineers are investigating the possibility that a 7/8' gold- plated liquid oxygen post plug became dislodged and created three small holes in the liquid hydrogen tubes inside the nozzle on main engine No. 3 on Space Shuttle Columbia. The holes caused a hydrogen leak during the STS-93 launch of Columbia on July 23.

  17. 2,3,7, 8-TETRACHLORODIBENZO-P-DIOXIN (TCDD)-MEDIATED OXIDATIVE STRESS IN FEMALE CYP1A-2 KNOCKOUT (CYP1A2-/-) MICE

    EPA Science Inventory

    2,3,7,8-Tetrachlordibenzo-p-dioxin (TCDD)-Mediated Oxidative Stress in Female CYP1A2 Knockout (CYP1A2-/-) Mice

    Deborah Burgin1, Janet Diliberto2, Linda Birnbaum2
    1UNC Toxicology; 2USEPA/ORD/NHEERL, RTP, NC

    Most of the effects due to TCDD exposure are mediated via...

  18. COMPARATIVE SENSITIVITY OF DIFFERENT LIFE-STAGES OF MEDAKA (ORYZIAS LATIPES) AND BROOK TROUT (SALVELINUS FONTINALIS) TO 2,3,7,8-TCDD

    EPA Science Inventory

    The early life stages of fish are known to be more sensitive than the adults to the toxicological effects of 2,3,7,8-tetrachlorodibenzo(p)dioxide (TCDD). TCDD concentrations in surface waters are sufficiently low that direct exposure of the developing embryo is unlikely to be o...

  19. Small Schools Mathematics Curriculum, Grades 7-8: Reading, Language Arts, Mathematics, Science, Social Studies. Scope, Objectives, Activities, Resources, Monitoring Procedures.

    ERIC Educational Resources Information Center

    Hartl, David, Ed.; And Others

    Developed during the 1976-77 school year to assist Washington grade 7-8 teachers in small school districts with the improvement of curriculum and instruction, this learning-objective-based curriculum suggests activities, monitoring procedures and resources for mathematics. Introductory materials describe the organization of Small School materials,…

  20. CYP1A2 DOES NOT PLAY A CRITICAL ROLE IN 2, 3 7, 8-TETRACHLORODIBENZO-P-DIOXIN-INDUCED IMMUNOSUPRESSION

    EPA Science Inventory

    CYP1A2 IS NOT REQUIRED FOR 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN-INDUCED IMMUNOSUPPRESSION Smialowicz, Ralph J1; Burgin, Deborah E2; Williams, Wanda C1; Diliberto, Janet J1; Birnbaum, Linda S1
    1 Experimental Toxicology Division, US EPA, RTP, NC, USA; 2Curriculum in Toxicology, U...

  1. 2,3,7,8-Tetrachlorodibenzo-P-Dioxin (Tcdd) Dose-Response Studies: Preliminary Literature Search Results and Request for Additional Studies

    EPA Science Inventory

    EPA invited the public to comment on the preliminary list of in vivo mammalian dose-response citations for 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD). This list was compiled as a first step in the development of EPA’s response to the National Academy of Sciences comments (NAS, 2...

  2. Aryl hydrocarbon receptor facilitates DNA strand breaks and 8-oxo-2'-deoxyguanosine formation by the aldo-keto reductase product benzo[a]pyrene-7,8-dione.

    PubMed

    Park, Jong-Heum; Mangal, Dipti; Frey, Alexander J; Harvey, Ronald G; Blair, Ian A; Penning, Trevor M

    2009-10-23

    Polycyclic aromatic hydrocarbon (PAH) o-quinones produced by aldo-keto reductases are ligands for the aryl hydrocarbon receptor (AhR) (Burczynski, M. E., and Penning, T. M. (2000) Cancer Res. 60, 908-915). They induce oxidative DNA lesions (reactive oxygen species-mediated DNA strand breaks and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dGuo) formation) in human lung cells. We tested whether the AhR enhances PAH o-quinone-mediated oxidative DNA damage by translocating these ligands to the nucleus. Using the single cell gel electrophoresis (comet) assay to detect DNA strand breaks in murine hepatoma Hepa1c1c7 cells and its AhR- and aryl hydrocarbon receptor nuclear translocator-deficient variants, benzo[a]pyrene-7,8-dione (B[a]P-7,8-dione) produced fewer DNA strand breaks in AhR-deficient cells compared with aryl hydrocarbon receptor nuclear translocator-deficient and wild type Hepa1c1c7 cells. Decreased DNA strand breaks were also observed in human bronchoalveolar H358 cells in which the AhR was silenced by siRNA. The antioxidant alpha-tocopherol and the iron chelator/antioxidant desferal decreased the formation of B[a]P-7,8-dione-mediated DNA strand breaks indicating that they were reactive oxygen species-dependent. By coupling the comet assay to 8-oxoguanine glycosylase (hOGG1), which excises 8-oxo-Gua, strand breaks dependent upon this lesion were measured. hOGG1 treatment produced more DNA single strand breaks in B[a]P-7,8-dione-treated Hepa cells and H358 cells than in its absence. The levels of hOGG1-dependent DNA strand breaks mediated by B[a]P-7,8-dione were lower in AhR-deficient Hepa and AhR knockdown H358 cells. The AhR antagonist alpha-naphthoflavone also attenuated B[a]P-7,8-dione-mediated DNA strand breaks. The decrease in 8-oxo-dGuo levels in AhR-deficient Hepa cells and AhR knockdown H358 cells was validated by immunoaffinity capture stable isotope dilution ([(15)N(5)]8-oxo-dGuo) liquid chromatography-electrospray ionization/multiple reaction

  3. Arsenic inhibits induction of cytochrome P450 1A1 by 2,3,7,8-tetrachlorodibenzo-p-dioxin in human hepatoma cells.

    PubMed

    Chao, How-Ran; Tsou, Tsui-Chun; Li, Lih-Ann; Tsai, Feng-Yuan; Wang, Ya-Fen; Tsai, Cheng-Hsien; Chang, Eddy Essen; Miao, Zhi-Feng; Wu, Chia-Hsin; Lee, Wen-Jhy

    2006-09-21

    The aim of this study was to examine the arsenic effect on activation of aryl hydrocarbon receptor (AhR)-mediated gene expression by 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) in human hepatoma cells. The human hepatoma Huh7 cells were treated with sodium arsenite (NaAsO2) from 0.5 to 20 microM for 24 h. Our data revealed that NaAsO2 < or = 10 microM caused no significant cytotoxic effect on Huh7 cells (p>0.05). We also established a dioxin-responsive element (DRE)-mediated Chemical Activated LUciferase eXpression (CALUX) cell line, Huh7-DRE-Luc, by stable transfection of Huh7 with a DRE-driven firefly luciferase reporter plasmid (4xDRE-TATA-Luc). Treatments of Huh7-DRE-Luc and Huh7 with NaAsO2 attenuated the 2,3,7,8-TCDD-induced DRE-CALUX and cytochrome P450 1A1 (CYP1A1) activations, respectively, in a dose-dependent manner. We found that the calculated CALUX-toxic equivalent (TEQ) levels induced by cotreatment of NaAsO2 > or = 3.0 microM and 10 nM 2,3,7,8-TCDD were significantly lower than that induced by 2,3,7,8-TCDD alone (p<0.05). In the present study, we demonstrated that arsenic not only inhibited the TCDD-induced CYP1A1 activation but also interfered with DRE-CALUX bioassay in human hepatoma cells. Our finding also suggests that extensive cleanup of sample for removal of any possible interfering factor is critical to guarantee the accuracy of dioxin-TEQ levels using DRE-CALUX bioassay. PMID:16713074

  4. Reading and Writing Performances of Children 7-8 Years of Age with Developmental Coordination Disorder in Taiwan

    ERIC Educational Resources Information Center

    Cheng, Hsiang-Chun; Chen, Jenn-Yeu; Tsai, Chia-Liang; Shen, Miau-Lin; Cherng, Rong-Ju

    2011-01-01

    Developmental coordination disorder (DCD) refers to a delay in motor development that does not have any known medical cause. Studies conducted in English speaking societies have found that children with DCD display a higher co-occurrence rate of learning difficulties (e.g., problems in reading and writing) than typically developing (TD) children.…

  5. Innovation for Strength. Proceedings of the Annual Accreditation and Quality Assurance Conference (Philadelphia, Pennsylvania, December 7-8, 1998).

    ERIC Educational Resources Information Center

    Commission on Higher Education, Philadelphia, PA. Middle States Association of Colleges and Schools.

    These proceedings of the annual accreditation and quality assurance conference present the following papers: "The Coming Revolution in Higher Education" (Arthur Levine); "Corporate/College Alliances" (Jeanne C. Meister); "Why Are We Educators?" (Catharine R. Stimpson); "Serving an Increasingly Adult Student Population: Lessons from Nordstrom and…

  6. Effects of short-term exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin on microRNA expression in zebrafish embryos

    SciTech Connect

    Jenny, Matthew J.; Aluru, Neelakanteswar; Hahn, Mark E.

    2012-10-15

    Although many drugs and environmental chemicals are teratogenic, the mechanisms by which most toxicants disrupt embryonic development are not well understood. MicroRNAs, single-stranded RNA molecules of ∼ 22 nt that regulate protein expression by inhibiting mRNA translation and promoting mRNA sequestration or degradation, are important regulators of a variety of cellular processes including embryonic development and cellular differentiation. Recent studies have demonstrated that exposure to xenobiotics can alter microRNA expression and contribute to the mechanisms by which environmental chemicals disrupt embryonic development. In this study we tested the hypothesis that developmental exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a well-known teratogen, alters microRNA expression during zebrafish development. We exposed zebrafish embryos to DMSO (0.1%) or TCDD (5 nM) for 1 h at 30 hours post fertilization (hpf) and measured microRNA expression using several methods at 36 and 60 hpf. TCDD caused strong induction of CYP1A at 36 hpf (62-fold) and 60 hpf (135-fold) as determined by real-time RT-PCR, verifying the effectiveness of the exposure. MicroRNA expression profiles were determined using microarrays (Agilent and Exiqon), next-generation sequencing (SOLiD), and real-time RT-PCR. The two microarray platforms yielded results that were similar but not identical; both showed significant changes in expression of miR-451, 23a, 23b, 24 and 27e at 60 hpf. Multiple analyses were performed on the SOLiD sequences yielding a total of 16 microRNAs as differentially expressed by TCDD in zebrafish embryos. However, miR-27e was the only microRNA to be identified as differentially expressed by all three methods (both microarrays, SOLiD sequencing, and real-time RT-PCR). These results suggest that TCDD exposure causes modest changes in expression of microRNAs, including some (miR-451, 23a, 23b, 24 and 27e) that are critical for hematopoiesis and cardiovascular

  7. Timing is everything: neural response dynamics during syllable processing and its relation to higher-order cognition in schizophrenia and healthy comparison subjects.

    PubMed

    Dale, Corby L; Findlay, Anne M; Adcock, R Alison; Vertinski, Mary; Fisher, Melissa; Genevsky, Alexander; Aldebot, Stephanie; Subramaniam, Karuna; Luks, Tracy L; Simpson, Gregory V; Nagarajan, Srikantan S; Vinogradov, Sophia

    2010-02-01

    Successful linguistic processing requires efficient encoding of successively-occurring auditory input in a time-constrained manner, especially under noisy conditions. In this study we examined the early neural response dynamics to rapidly-presented successive syllables in schizophrenia participants and healthy comparison subjects, and investigated the effects of noise on these responses. We used magnetoencephalography (MEG) to reveal the time-course of stimulus-locked activity over bilateral auditory cortices during discrimination of syllable pairs that differed either in voice onset time (VOT) or place of articulation (POA), in the presence or absence of noise. We also examined the association of these early neural response patterns to higher-order cognitive functions. The M100 response, arising from auditory cortex and its immediate environs, showed less attenuation to the second syllable in patients with schizophrenia than healthy comparison subjects during VOT-based discrimination in noise. M100 response amplitudes were similar between groups for the first syllable during all three discrimination conditions, and for the second syllable during VOT-based discrimination in quiet and POA-based discrimination in noise. Across subjects, the lack of M100 attenuation to the second syllable during VOT-based discrimination in noise was associated with poorer task accuracy, lower education and IQ, and lower scores on measures of Verbal Learning and Memory and Global Cognition. Because the neural response to the first syllable was not significantly different between groups, nor was a schizophrenia-related difference obtained in all discrimination tasks, early linguistic processing dysfunction in schizophrenia does not appear to be due to general sensory input problems. Rather, data suggest that faulty temporal integration occurs during successive syllable processing when the signal-to-noise ratio is low. Further, the neural mechanism by which the second syllable is

  8. Timing is everything: Neural response dynamics during syllable processing and its relation to higher-order cognition in schizophrenia and healthy comparison subjects

    PubMed Central

    Dale, Corby L.; Findlay, Anne M.; Adcock, R. Alison; Vertinski, Mary; Fisher, Melissa; Genevsky, Alexander; Aldebot, Stephanie; Subramaniam, Karuna; Luks, Tracy L.; Simpson, Gregory V.; Nagarajan, Srikantan S.; Vinogradov, Sophia

    2009-01-01

    Successful linguistic processing requires efficient encoding of successively-occurring auditory input in a time-constrained manner, especially under noisy conditions. In this study we examined the early neural response dynamics to rapidly-presented successive syllables in schizophrenia participants and healthy comparison subjects, and investigated the effects of noise on these responses. We used magnetoencephalography (MEG) to reveal the time-course of stimulus-locked activity over bilateral auditory cortices during discrimination of syllable pairs that differed either in voice onset time (VOT) or place of articulation (POA), in the presence or absence of noise. We also examined the association of these early neural response patterns to higher-order cognitive functions. The M100 response, arising from auditory cortex and its immediate environs, showed less attenuation to the second syllable in patients with schizophrenia than healthy comparison subjects during VOT-based discrimination in noise. M100 response amplitudes were similar between groups for the first syllable during all three discrimination conditions, and for the second syllable during VOT-based discrimination in quiet and POA-based discrimination in noise. Across subjects, the lack of M100 attenuation to the second syllable during VOT-based discrimination in noise was associated with poorer task accuracy, lower education and IQ, and lower scores on measures of Verbal Learning and Memory and Global Cognition. Because the neural response to the first syllable was not significantly different between groups, nor was a schizophrenia-related difference obtained in all discrimination tasks, early linguistic processing dysfunction in schizophrenia does not appear to be due to general sensory input problems. Rather, data suggest that faulty temporal integration occurs during successive syllable processing when the signal-to-noise ratio is low. Further, the neural mechanism by which the second syllable is

  9. Developmental exposure to 2,3,7,8 tetrachlorodibenzo-p-dioxin attenuates later-life Notch1-mediated T cell development and leukemogenesis

    SciTech Connect

    Ahrenhoerster, Lori S.; Leuthner, Tess C.; Tate, Everett R.; Lakatos, Peter A.; Laiosa, Michael D.

    2015-03-01

    Over half of T cell acute lymphoblastic leukemia (T-ALL) patients have activating mutations in the Notch gene. Moreover, the contaminant 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) is a known carcinogen that mediates its toxicity through the aryl hydrocarbon receptor (AHR), and crosstalk between activated AHR and Notch signaling pathways has previously been observed. Given the importance of Notch signaling in thymocyte development and T-ALL disease progression, we hypothesized that the activated AHR potentiates disease initiation and progression in an in vivo model of Notch1-induced thymoma. This hypothesis was tested utilizing adult and developmental exposure paradigms to TCDD in mice expressing a constitutively active Notch1 transgene (Notch{sup ICN-TG}). Following exposure of adult Notch{sup ICN-TG} mice to a single high dose of TCDD, we observed a significant increase in the efficiency of CD8 thymocyte generation. We next exposed pregnant mice to 3 μg/kg of TCDD throughout gestation and lactation to elucidate effects of developmental AHR activation on later-life T cell development and T-ALL-like thymoma susceptibility induced by Notch1. We found that the vehicle-exposed Notch{sup ICN-TG} offspring have a peripheral T cell pool heavily biased toward the CD4 lineage, while TCDD-exposed Notch{sup ICN-TG} offspring were biased toward the CD8 lineage. Furthermore, while the vehicle-exposed NotchICN-TG mice showed increased splenomegaly and B to T cell ratios indicative of disease, mice developmentally exposed to TCDD were largely protected from disease. These studies support a model where developmental AHR activation attenuates later-life Notch1-dependent impacts on thymocyte development and disease progression. - Highlights: • Adult mice exposed to 30 μg/kg TCDD have higher efficiency of CD8 thymocyte generation. • Mice carrying a constitutively active Notch transgene were exposed to 3 μg/kg TCDD throughout development. • Progression of Notch

  10. Study Of The Rupture Process Of The 2015 Mw7.8 Izu-Bonin Earthquake And Its Implication To Deep-Focus Earthquake Genesis.

    NASA Astrophysics Data System (ADS)

    Jian, P. R.; Hung, S. H.; Meng, L.

    2015-12-01

    On May 30, 2015, a major Mw7.8 great deep earthquake occurred at the base of the mantle transition zone (MTZ), approximately 680 km deep within the Pacific Plate which subducts westward under the Philippine Sea Plate along the Izu-Bonin trench. A global P wave tomographic image indicates that a tabular high-velocity structure delineated by ~1% faster than the ambient mantle plunges nearly vertical to a depth at most 600 km and afterword flattens and stagnates within the MTZ. Almost all the deep earthquakes in this region are clustered inside this fast anomaly corresponding to the cold core of the subducting slab. Those occurring at depth between 400~500 km close to the hinge of the bending slab show down-dip compressional focal mechanisms and reflect episodic release of compressive strain accumulated in the slab. The 2015 deep event, however, separated from the others, occurred uniquely near the base of the lithosphere with a down-dip extension mechanism, consistent with the notion that the outer portion of the folded slab experiences extensional bending stress. Here we perform a 3D MUSIC back-projection (BP) rupture imaging for this isolated deep event using P and pP waveforms individually from the European, North American and Australian array data. By integrating P- and pP- BP images in frequencies of 0.1-1 Hz obtained from three array observations with different azimuth, we first ascertain the most possible fault plan is the SW-dipping subhorizontal one. Then, from back-projecting higher frequency waveforms at 1-1.5 Hz onto the obtained fault plane, we find the rupture initially propagates slowly along the strike (SW-direction), and makes a turn to the NNW-direction at ~12s after the onset of rupture. The MUSIC psudospectrum over totally 20s rupture duration reveals that most seismic energy radiation takes place at the initial 8s of the first rupture along the strike, 10-15 km long region, while the along-updip second rupture lasting for 6-10s has a rupture

  11. Behavioral Rhythmicity of Mice Lacking AhR and Attenuation of Light-induced Phase Shift by 2,3,7,8-Tetracholordibenzo-p-dioxin

    PubMed Central

    Mukai, Motoko; Lin, Tien-Min; Peterson, Richard E.; Cooke, Paul S.; Tischkau, Shelley A.

    2008-01-01

    Transcription factors belonging to the Per/Arnt/Sim (PAS) domain family are highly conserved and many are involved in circadian rhythm regulation. One member of this family, aryl hydrocarbon receptor (AhR), is an orphan receptor whose physiological role is unknown. Recent findings have led to the hypothesis that AhR has a role in circadian rhythm, which is the focus of the present investigation. First, time-of-day dependent mRNA expression of AhR and its signaling target, cytochrome p4501A1 (Cyp1a1) was determined in C57BL/6J mice by quantitative RT-PCR. Circadian expression of AhR and Cyp1a1 was observed both in the suprachiasmatic nucleus (SCN) and liver. Next, the circadian phenotype of mice lacking AhR (AhRKO) was investigated using behavioral monitoring. Intact AhRKO mice had robust circadian rhythmicity with a similar tau under constant conditions compared to wild-type mice, but a significant difference in tau was observed between genotypes in ovariectomized female mice. Time to re-entrainment following 6-h advances or delays of the light/dark cycle was not significantly different between genotypes. However, mice exposed to the AhR agonist 2,3,7,8-tetracholorodibenzo-p-dioxin (TCDD, 1 μg/kg BW) displayed decreased phase shifts in response to light and had altered expression of Per1 and Bmal1. These results suggest that chronic activation of AhR may affect the ability of the circadian timekeeping system to adjust to alterations in environmental lighting by affecting canonical clock genes. Further studies are necessary to decipher the mechanism of how AhR agonists could disrupt light-induced phase shifts. If AhR does have a role in circadian rhythm, it may share redundant roles with other PAS domain proteins and/or the role of AhR may not be exhibited in the behavioral activity rhythm, but could be important elsewhere in the peripheral circadian system. PMID:18487412

  12. Identification of aryl hydrocarbon receptor binding targets in mouse hepatic tissue treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Lo, Raymond; Celius, Trine; Forgacs, Agnes L.; Dere, Edward; MacPherson, Laura; Harper, Patricia; Zacharewski, Timothy; Matthews, Jason

    2011-11-15

    Genome-wide, promoter-focused ChIP-chip analysis of hepatic aryl hydrocarbon receptor (AHR) binding sites was conducted in 8-week old female C57BL/6 treated with 30 {mu}g/kg/body weight 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) for 2 h and 24 h. These studies identified 1642 and 508 AHR-bound regions at 2 h and 24 h, respectively. A total of 430 AHR-bound regions were common between the two time points, corresponding to 403 unique genes. Comparison with previous AHR ChIP-chip studies in mouse hepatoma cells revealed that only 62 of the putative target genes overlapped with the 2 h AHR-bound regions in vivo. Transcription factor binding site analysis revealed an over-representation of aryl hydrocarbon response elements (AHREs) in AHR-bound regions with 53% (2 h) and 68% (24 h) of them containing at least one AHRE. In addition to AHREs, E2f-Myc activator motifs previously implicated in AHR function, as well as a number of other motifs, including Sp1, nuclear receptor subfamily 2 factor, and early growth response factor motifs were also identified. Expression microarray studies identified 133 unique genes differentially regulated after 4 h treatment with TCDD. Of which, 39 were identified as AHR-bound genes at 2 h. Ingenuity Pathway Analysis on the 39 AHR-bound TCDD responsive genes identified potential perturbation in biological processes such as lipid metabolism, drug metabolism, and endocrine system development as a result of TCDD-mediated AHR activation. Our findings identify direct AHR target genes in vivo, highlight in vitro and in vivo differences in AHR signaling and show that AHR recruitment does not necessarily result in changes in target gene expression. -- Highlights: Black-Right-Pointing-Pointer ChIP-chip analysis of hepatic AHR binding after 2 h and 24 h of TCDD. Black-Right-Pointing-Pointer We identified 1642 and 508 AHR-bound regions at 2 h and 24 h. Black-Right-Pointing-Pointer 430 regions were common to both time points and highly enriched with

  13. Nrf2 protects against 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced oxidative injury and steatohepatitis

    SciTech Connect

    Lu Hong; Cui Wei; Klaassen, Curtis D.

    2011-10-15

    Previous studies demonstrate that Nrf2, a master regulator of antioxidative responses, is essential in mediating induction of many antioxidative enzymes by acute activation of the AhR. However, the role of Nrf2 in protecting against oxidative stress and DNA damage induced by sustained activation of the AhR remains unknown and was investigated herein. Tissue and blood samples were collected from wild-type (WT) and Nrf2-null mice 21 days after administration of a low-toxic dose (10 {mu}g/kg ip) of TCDD. Only Nrf2-null mice lost body weight after TCDD treatment; however, blood levels of ALT were not markedly changed in either genotype, indicating a lack of extensive necrosis. Compared to livers of TCDD-treated WT mice, livers of TCDD-treated Nrf2-null mice had: 1) degenerated hepatocytes, lobular inflammation, marked fat accumulation, and higher mRNA expression of inflammatory and fibrotic genes; 2) depletion of glutathione, elevation in lipid peroxidation and marker of DNA damage; 3) attenuated induction of phase-II enzymes Nqo1, Gsta1/2, and Ugt2b35 mRNAs, but higher induction of cytoprotective Ho-1, Prdx1, Trxr1, Gclc, and Epxh1 mRNAs; 4) higher mRNA expression of Fgf21 and triglyceride-synthesis genes, but down-regulation of bile-acid-synthesis genes and cholesterol-efflux transporters; and 5) trend of induction/activation of c-jun and NF-kB. Additionally, TCDD-treated Nrf2-null mice had impaired adipogenesis in white adipose tissue. In conclusion, Nrf2 protects livers of mice against oxidative stress, DNA damage, and steatohepatitis induced by TCDD-mediated sustained activation of the AhR. The aggravated hepatosteatosis in TCDD-treated Nrf2-null mice is due to increased lipogenesis in liver and impaired lipogenesis in white adipose tissue. - Highlights: > TCDD causes hepatosteatosis and induction of Nrf2-target genes in wild-type mice. > TCDD causes weight loss, oxidative injury, and steatohepatitis in Nrf2-null mice. > Livers of TCDD-treated Nrf2-null mice have

  14. The thermodynamic properties of 4,5,9,10-tetrahydropyrene and 1,2,3,6,7,8-hexahydropyrene. [Tetrahydropyrene and hexahydropyrene

    SciTech Connect

    Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.; Smith, N.K.; Steele, W.V.

    1992-12-01

    Measurements leading to the calculation of the ideal-gas thermodynamic properties are reported for 4,5,9,10-tetrahydropyrene and 1,2,3,6,7,8-hexahydropyrene. Experimental methods included combustion calorimetry, adiabatic heat-capacity calorimetry, vibrating-tube densitometry, comparative ebulliometry, inclined-piston gauge manometry, and differential-scanning calorimetry (d.s.c.). Critical properties were estimated for both materials based on the measurement results. Entropies, enthalpies, and Gibbs energies of formation were derived for the ideal gases for selected temperatures between 380 K and 700 K. The property-measurement results reported here for 4,5,9,10-tetrahydropyrene and 1,2,3,6,7,8-hexahydropyrene are the first for these important intermediates in the pyrene/H[sub 2] hydrogenation reaction network.

  15. The transcriptional response to oxidative stress during vertebrate development: effects of tert-butylhydroquinone and 2,3,7,8-tetrachlorodibenzo-p-dioxin.

    PubMed

    Hahn, Mark E; McArthur, Andrew G; Karchner, Sibel I; Franks, Diana G; Jenny, Matthew J; Timme-Laragy, Alicia R; Stegeman, John J; Woodin, Bruce R; Cipriano, Michael J; Linney, Elwood

    2014-01-01

    Oxidative stress is an important mechanism of chemical toxicity, contributing to teratogenesis and to cardiovascular and neurodegenerative diseases. Developing animals may be especially sensitive to chemicals causing oxidative stress. The developmental expression and inducibility of anti-oxidant defenses through activation of NF-E2-related factor 2 (NRF2) affect susceptibility to oxidants, but the embryonic response to oxidants is not well understood. To assess the response to chemically mediated oxidative stress and how it may vary during development, zebrafish embryos, eleutheroembryos, or larvae at 1, 2, 3, 4, 5, and 6 days post fertilization (dpf) were exposed to DMSO (0.1%), tert-butylhydroquinone (tBHQ; 10 µM) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 2 nM) for 6 hr. Transcript abundance was assessed by real-time qRT-PCR and microarray. qRT-PCR showed strong (4- to 5-fold) induction of gstp1 by tBHQ as early as 1 dpf. tBHQ also induced gclc (2 dpf), but not sod1, nqo1, or cyp1a. TCDD induced cyp1a but none of the other genes. Microarray analysis showed that 1477 probes were significantly different among the DMSO-, tBHQ-, and TCDD-treated eleutheroembryos at 4 dpf. There was substantial overlap between genes induced in developing zebrafish and a set of marker genes induced by oxidative stress in mammals. Genes induced by tBHQ in 4-dpf zebrafish included those involved in glutathione synthesis and utilization, signal transduction, and DNA damage/stress response. The strong induction of hsp70 determined by microarray was confirmed by qRT-PCR and by use of transgenic zebrafish expressing enhanced green fluorescent protein (EGFP) under control of the hsp70 promoter. Genes strongly down-regulated by tBHQ included mitfa, providing a molecular explanation for the loss of pigmentation in tBHQ-exposed embryos. These data show that zebrafish embryos are responsive to oxidative stress as early as 1 dpf, that responsiveness varies with development in a gene

  16. The Transcriptional Response to Oxidative Stress during Vertebrate Development: Effects of tert-Butylhydroquinone and 2,3,7,8-Tetrachlorodibenzo-p-Dioxin

    PubMed Central

    Hahn, Mark E.; McArthur, Andrew G.; Karchner, Sibel I.; Franks, Diana G.; Jenny, Matthew J.; Timme-Laragy, Alicia R.; Stegeman, John J.; Woodin, Bruce R.; Cipriano, Michael J.; Linney, Elwood

    2014-01-01

    Oxidative stress is an important mechanism of chemical toxicity, contributing to teratogenesis and to cardiovascular and neurodegenerative diseases. Developing animals may be especially sensitive to chemicals causing oxidative stress. The developmental expression and inducibility of anti-oxidant defenses through activation of NF-E2-related factor 2 (NRF2) affect susceptibility to oxidants, but the embryonic response to oxidants is not well understood. To assess the response to chemically mediated oxidative stress and how it may vary during development, zebrafish embryos, eleutheroembryos, or larvae at 1, 2, 3, 4, 5, and 6 days post fertilization (dpf) were exposed to DMSO (0.1%), tert-butylhydroquinone (tBHQ; 10 µM) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 2 nM) for 6 hr. Transcript abundance was assessed by real-time qRT-PCR and microarray. qRT-PCR showed strong (4- to 5-fold) induction of gstp1 by tBHQ as early as 1 dpf. tBHQ also induced gclc (2 dpf), but not sod1, nqo1, or cyp1a. TCDD induced cyp1a but none of the other genes. Microarray analysis showed that 1477 probes were significantly different among the DMSO-, tBHQ-, and TCDD-treated eleutheroembryos at 4 dpf. There was substantial overlap between genes induced in developing zebrafish and a set of marker genes induced by oxidative stress in mammals. Genes induced by tBHQ in 4-dpf zebrafish included those involved in glutathione synthesis and utilization, signal transduction, and DNA damage/stress response. The strong induction of hsp70 determined by microarray was confirmed by qRT-PCR and by use of transgenic zebrafish expressing enhanced green fluorescent protein (EGFP) under control of the hsp70 promoter. Genes strongly down-regulated by tBHQ included mitfa, providing a molecular explanation for the loss of pigmentation in tBHQ-exposed embryos. These data show that zebrafish embryos are responsive to oxidative stress as early as 1 dpf, that responsiveness varies with development in a gene

  17. Polychlorinated dibenzo-p-dioxins, dibenzofurans, biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents in fishes from Saginaw Bay, Michigan

    SciTech Connect

    Giesy, J.P.; Tillitt, D.E.; Jude, D.J.

    1997-04-01

    Concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated naphthalenes (PCNs), polychlorinated dibenzothiophenes (PCDTs), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) equivalents were measured in composite samples of forage fishes and several sizes of walleyes (Stizostedion vitreum) and common carp (Cyprinus carpio) collected from Saginaw Bay, Michigan, USA. The concentrations of 2,3,7,8-TCDD equivalents determined from the use of TCDD equivalency factors (TEFs) and instrumentally determined concentrations of individual congeners were designated TEq. The 2,3,7,8-TCDD equivalents determined on the same extracts with the H4IIE bioassay were defined as TCDD-EQ. Concentrations of TCDD-EQ and TEq were significantly, but poorly correlated (R{sup 2} = 0.44). Concentrations of TCDD-EQ and TEq ranged from 10.6 to 348 and 13.5 to 69.5 ng/kg, wet weight, respectively. The ratio of TCDD-EQ to TEq ranged from 0.5 to 5.0, with the greatest ratio observed in common carp but the average ratio between TEq and TCDD-EQ was approximately 1.0. In common carp, larger walleye, and medium-sized alewife (Alosa pseudoharengus) there were significant concentrations of TCDD-EQ that could not be accounted for by TEq calculated from an additive model of PCBs, PCDDs, or PCDFs. As much as 75% of the TCDD-EQ in some samples could not be accounted for by TEqs. It is unlikely that PCNs, PCDTs, or polychlorinated diphenyl ethers (PCDEs) occurred at concentrations that were, based on their relative potencies, great enough to contribute significant quantities of TCDD-EQ. The discrepancy between TCDD-EQs and TEqs was not due to antagonisms among congeners or extraction efficiencies.

  18. COMPARISON OF OVERALL METABOLISM OF 1, 2, 7, 8-PECDD IN CYP1A2(-L-) KNOCKOUT AND C57BL/6N PARENTAL STRAINS OF MICE

    EPA Science Inventory

    COMPARISON OF OVERALL METABOLISM OF 1,2,3,7,8-PeCDD
    IN CYP1A2 (-/-) KNOCKOUT AND C57BL/6N PARENTAL
    STRAINS OF MICE

    Heldur Hakk1 and Janet J. Diliberto2

    1 USDA-ARS, Biosciences Research Laboratory, P.O. Box 5674, Fargo, ND, USA
    2 US EPA, ORD, National Heal...

  19. Suppression of molecular inflammatory pathways by Toll-like receptor 7, 8, and 9 antagonists in a model of IL-23-induced skin inflammation.

    PubMed

    Suárez-Fariñas, Mayte; Arbeit, Robert; Jiang, Weiwen; Ortenzio, Francesca S; Sullivan, Tim; Krueger, James G

    2013-01-01

    Psoriasis is a complex inflammatory disease resulting from the activation of T helper (Th) 1 and Th17 cells. Recent evidence suggests that abnormal activation of Toll-like receptors (TLRs) 7, 8 and 9 contributes to the initiation and maintenance of psoriasis. We have evaluated the effects of TLR antagonists on the gene expression profile in an IL-23-induced skin inflammation model in mice. Psoriasis-like skin lesions were induced in C57BL/6 mice by intradermal injection of IL-23 in the dorsum. Two TLR antagonists were compared: IMO-3100, an antagonist of TLRs 7 and 9, and IMO-8400, an antagonist of TLRs 7, 8 and 9, both of which previously have been shown to reduce epidermal hyperplasia in this model. Skin gene expression profiles of IL-23-induced inflammation were compared with or without TLR antagonist treatment. IL-23 injection resulted in alteration of 5100 gene probes (fold change ≥ 2, FDR < 0.05) including IL-17 pathways that are up-regulated in psoriasis vulgaris. Targeting TLRs 7, 8 and 9 with IMO-8400 resulted in modulation of more than 2300 mRNAs while targeting TLRs 7 and 9 with IMO-3100 resulted in modulation of more than 1900 mRNAs. Both agents strongly decreased IL-17A expression (>12-fold reduction), normalized IL-17 induced genes such as beta-defensin and CXCL1, and normalized aberrant expression of keratin 16 (indicating epidermal hyperplasia). These results suggest that IL-23-driven inflammation in mouse skin may be dependent on signaling mediated by TLRs 7, 8, and 9 and that these receptors represent novel therapeutic targets in psoriasis vulgaris and other diseases with similar pathophysiology. PMID:24386404

  20. Suppression of Molecular Inflammatory Pathways by Toll-Like Receptor 7, 8, and 9 Antagonists in a Model of IL-23-Induced Skin Inflammation

    PubMed Central

    Suárez-Fariñas, Mayte; Arbeit, Robert; Jiang, Weiwen; Ortenzio, Francesca S.; Sullivan, Tim; Krueger, James G.

    2013-01-01

    Psoriasis is a complex inflammatory disease resulting from the activation of T helper (Th) 1 and Th17 cells. Recent evidence suggests that abnormal activation of Toll-like receptors (TLRs) 7, 8 and 9 contributes to the initiation and maintenance of psoriasis. We have evaluated the effects of TLR antagonists on the gene expression profile in an IL-23-induced skin inflammation model in mice. Psoriasis-like skin lesions were induced in C57BL/6 mice by intradermal injection of IL-23 in the dorsum. Two TLR antagonists were compared: IMO-3100, an antagonist of TLRs 7 and 9, and IMO-8400, an antagonist of TLRs 7, 8 and 9, both of which previously have been shown to reduce epidermal hyperplasia in this model. Skin gene expression profiles of IL-23-induced inflammation were compared with or without TLR antagonist treatment. IL-23 injection resulted in alteration of 5100 gene probes (fold change ≥ 2, FDR < 0.05) including IL-17 pathways that are up-regulated in psoriasis vulgaris. Targeting TLRs 7, 8 and 9 with IMO-8400 resulted in modulation of more than 2300 mRNAs while targeting TLRs 7 and 9 with IMO-3100 resulted in modulation of more than 1900 mRNAs. Both agents strongly decreased IL-17A expression (>12-fold reduction), normalized IL-17 induced genes such as beta-defensin and CXCL1, and normalized aberrant expression of keratin 16 (indicating epidermal hyperplasia). These results suggest that IL-23-driven inflammation in mouse skin may be dependent on signaling mediated by TLRs 7, 8, and 9 and that these receptors represent novel therapeutic targets in psoriasis vulgaris and other diseases with similar pathophysiology. PMID:24386404