Science.gov

Sample records for 2-4 times higher

  1. Time Sequence of Jupiter's Equatorial Region (Time Sets 2 & 4)

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Time sequence of Jupiter's equatorial region at 756 nanometers (nm). The mosaics cover an area of 34,000 kilometers by 22,000 kilometers and were taken ten hours (approximately one Jovian rotation) apart. The dark region near the center of the mosaic is an equatorial 'hotspot' similar to the Galileo Probe entry site. The near-infrared continuum filter shows the features of Jupiter's main visible cloud deck.

    Jupiter's atmospheric circulation is dominated by alternating jets of east/west (zonal) winds. The bands have different widths and wind speeds but have remained constant as long as telescopes and spacecraft have measured them. The top half of these mosaics lies within Jupiter's North Equatorial Belt, a westward (left) current. The bottom half shows part of the Equatorial Zone, a fast moving eastward current. The clouds near the hotspot are the fastest moving features in these mosaics, moving at about 100 meters per second, or 224 miles per hour.

    North is at the top. The mosaics cover latitudes 1 to 19 degrees and are centered at longitude 336 degrees West. The grid lines, fixed in longitude, mark 350 degrees west (on the left edge) with decreasing longitude lines marking every 5 degrees moving east (to the right). The smallest resolved features are tens of kilometers in size. These images were taken on December 17, 1996, at a range of 1.5 million kilometers by the Solid State Imaging system aboard NASA's Galileo spacecraft.

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

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

  2. Uptake and metabolism of 2,4,6-trinitrotoluene in higher plants.

    PubMed

    Görge, E; Brandt, S; Werner, D

    1994-12-01

    The fate of the explosive 2,4,6-TNT in plants is of major interest. Therefore, a method was developed to analyse TNT and derivatives in plant tissue. The method was utilized to investigate the uptake and metabolism of TNT inMedicago sativa andAllium schoenoprasum grown in hydroponic cultures containing TNT levels of 0.1 to 10 mg/1. Detectable concentrations of nitrotoluenes were significantly higher inAllium schoenoprasum than inMedicago sativa. The uptake of TNT in plants was directly related to the initial TNT level. The principal nitroaromatic components in roots and shoots of both plant species were identified as 4-ADNT and 2-ADNT in equal amounts, with substantially less TNT.

  3. Soil-based phytotoxicity of 2,4,6-trinitrotoluene (TNT) to terrestrial higher plants

    PubMed

    Gong; Wilke; Fleischmann

    1999-02-01

    Seed germination and early stage seedling growth tests were conducted to determine the ecotoxicological threshold of 2,4, 6-trinitrotoluene (TNT) in two soils of different properties. Soils were amended up to 1,600 mg TNT kg-1 soil and four representative species of higher plants, two dicotyledons (Lepidium sativum L., common name: cress; and Brassica rapa Metzg., turnip) and two monocotyledons (Acena sativa L., oat; and Triticum aestivum L., wheat), were assessed. Cumulative seed germination and fresh shoot biomass were measured as evaluation endpoints. Phytotoxicity of TNT was observed to be affected by soil properties and varied between plant species. Cress and turnip showed higher sensitivity to TNT than did oat and wheat. The lowest observable adverse effect concentration (LOAEC) of TNT derived from this study was 50 mg kg-1 soil. In contrast to high TNT concentrations, low levels of TNT, i.e. , 5-25 mg kg-1 soil for cress and turnip and 25-50 mg kg-1 for oat and wheat, stimulated seedling growth. Oat was capable of tolerating as much as 1,600 mg TNT kg-1 and demonstrated a potential ability of TNT detoxification in one of the soils tested, suggesting that this plant might be useful in the bioremediation of TNT contaminated soils.

  4. Uptake of 2,4-D in higher plants from artificial rain.

    PubMed

    Løkke, H

    1984-02-01

    Sinapis alba L., Lapsana communis L., Achillea millefolium L., Brassica napus L., Lactuca sativa L., and Lycopersicum esculentum L. were exposed to 2,4-dichlorophenoxy [2-14C]acetic acid (2,4-D) at 10 micrograms liter-1 in artificial rain, pH 6.5 and 3.3. The 2,4-D was absorbed in all species tested. Concentrations of parent 2,4-D appeared at the highest level in Achillea (0.1 mg kg-1 dry wt), and at zero level in Lycopersicum. Twenty-one daily treatments at pH 6.5 for 30-min periods increased dry-matter concentrations (P less than or equal to 0.05) in the leaves of Achillea and decreased those in Brassica. No change in dry-matter concentration was observed in the leaves of Brassica by seven daily treatments for 30-min periods at pH 3.3.

  5. Uptake of 2,4-D in higher plants from artificial rain

    SciTech Connect

    Lokke, H.

    1984-02-01

    Sinapis alba L., Lapsana communis L., Achillea millefolium L., Brassica napus L., Lactuca sativa L., and Lycopersicum esculentum L. were exposed to 2,4-dichlorophenoxy (2-/sup 14/C)acetic acid (2,4-D) at 10 micrograms liter-1 in artificial rain, pH 6.5 and 3.3. The 2,4-D was absorbed in all species tested. Concentrations of parent 2,4-D appeared at the highest level in Achillea (0.1 mg kg-1 dry wt), and at zero level in Lycopersicum. Twenty-one daily treatments at pH 6.5 for 30-min periods increased dry-matter concentrations in the leaves of Achillea and decreased those in Brassica. No change in dry-matter concentration was observed in the leaves of Brassica by seven daily treatments for 30-min periods at pH 3.3.

  6. Time accurate application of the MacCormack 2-4 scheme on massively parallel computers

    NASA Technical Reports Server (NTRS)

    Hudson, Dale A.; Long, Lyle N.

    1995-01-01

    Many recent computational efforts in turbulence and acoustics research have used higher order numerical algorithms. One popular method has been the explicit MacCormack 2-4 scheme. The MacCormack 2-4 scheme is second order accurate in time and fourth order accurate in space, and is stable for CFL's below 2/3. Current research has shown that the method can give accurate results but does exhibit significant Gibbs phenomena at sharp discontinuities. The impact of adding Jameson type second, third, and fourth order artificial viscosity was examined here. Category 2 problems, the nonlinear traveling wave and the Riemann problem, were computed using a CFL number of 0.25. This research has found that dispersion errors can be significantly reduced or nearly eliminated by using a combination of second and third order terms in the damping. Use of second and fourth order terms reduced the magnitude of dispersion errors but not as effectively as the second and third order combination. The program was coded using Thinking Machine's CM Fortran, a variant of Fortran 90/High Performance Fortran, and was executed on a 2K CM-200. Simple extrapolation boundary conditions were used for both problems.

  7. 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…

  8. N=2, 4 supersymmetric gauge field theory in two-time physics

    SciTech Connect

    Bars, Itzhak; Kuo, Y.-C.

    2009-01-15

    In the context of two-time physics in 4+2 dimensions we construct the most general N=2, 4 supersymmetric Yang-Mills gauge theories for any gauge group G. This builds on our previous work for N=1 supersymmetry (SUSY). The action, the conserved SUSY currents, and the SU(N) covariant SUSY transformation laws are presented for both N=2 and N=4. When the equations of motion are used the SUSY transformations close to the supergroup SU(2,2|N) with N=1, 2, 4. The SU(2,2)=SO(4,2) subsymmetry is realized linearly on 4+2 dimensional flat spacetime. All fields, including vectors and spinors, are in 4+2 dimensions. The extra gauge symmetries in 2T field theory, together with the kinematic constraints that follow from the action, remove all the ghosts to give a unitary theory. By choosing gauges and solving the kinematic equations, the 2T field theory in 4+2 flat spacetime can be reduced to various shadows in various 3+1 dimensional (generally curved) spacetimes. These shadows are related to each other by dualities. The conformal shadows of our theories in flat 3+1 dimensions coincide with the well known counterpart N=1, 2, 4 supersymmetric massless renormalizable field theories in 3+1 dimensions. It is expected that our more symmetric new structures in 4+2 spacetime may be useful for nonperturbative or exact solutions of these theories.

  9. 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;…

  10. An Ultrathin Endoscope with a 2.4-mm Working Channel Shortens the Esophagogastroduodenoscopy Time by Shortening the Suction Time

    PubMed Central

    Shinozaki, Satoshi; Miura, Yoshimasa; Ino, Yuji; Shinozaki, Kenjiro; Lefor, Alan Kawarai; Yamamoto, Hironori

    2015-01-01

    Background/Aims: Poor suction ability through a narrow working channel prolongs esophagogastroduodenoscopy (EGD). The aim of this study was to evaluate suction with a new ultrathin endoscope (EG-580NW2; Fujifilm Corp.) having a 2.4-mm working channel in clinical practice. Methods: To evaluate in vitro suction, 200 mL water was suctioned and the suction time was measured. The clinical data of 117 patients who underwent EGD were retrospectively reviewed on the basis of recorded video, and the suction time was measured by using a stopwatch. Results: In vitro, the suction time with the EG-580NW2 endoscope was significantly shorter than that with the use of an ultrathin endoscope with a 2.0-mm working channel (EG-580NW; mean ± standard deviation, 22.7±1.1 seconds vs. 34.7±2.2 seconds; p<0.001). We analyzed the total time and the suction time for routine EGD in 117 patients (50 in the EG-580NW2 group and 67 in the EG-580NW group). In the EG-580NW2 group, the total time for EGD was significantly shorter than that in the EG-580NW group (275.3±42.0 seconds vs. 300.6±46.5 seconds, p=0.003). In the EG-580NW2 group, the suction time was significantly shorter than that in the EG-580NW group (19.2±7.6 seconds vs. 38.0±15.9 seconds, p<0.001). Conclusions: An ultrathin endoscope with a 2.4-mm working channel considerably shortens the routine EGD time by shortening the suction time, in comparison with an endoscope with a 2.0-mm working channel. PMID:26668798

  11. 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 ...

  12. Effect of feeding time on the performance of a sequencing batch reactor treating a mixture of 4-CP and 2,4-DCP.

    PubMed

    Sahinkaya, Erkan; Dilek, Filiz B

    2007-06-01

    This paper investigated the biodegradation kinetics of 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) separately in batch reactors and mixed in sequencing batch reactors (SBRs). Batch reactor experiments showed that both 4-CP and 2,4-DCP began to inhibit their own degradation at 53 and 25 mg l(-1), respectively, and that the Haldane equation gave a good fit to the experimental data because r(2) values were higher than 0.98. The maximum specific degradation rates (q(m)) were 130.3 and 112.4 mg g(-1) h for 4-CP and 2,4-DCP, respectively. The values of the half saturation (K(s)) and self-inhibition constants (K(i)) were 34.98 and 79.74 mg l(-1) for 4-CP, and 13.77 and 44.46 mg l(-1) for 2,4-DCP, respectively. The SBR was fed with a mixture of 220 mg l(-1) of 4-CP, 110 mg l(-1) of 2,4-DCP, and 300 mg l(-1) of peptone as biogenic substrate at varying feeding periods (0-8h) to evaluate the effect of feeding time on the performance of the SBR. During SBR operation, in addition to self-inhibition, 4-CP degradation was strongly and competitively inhibited by 2,4-DCP. The inhibitory effects were particularly pronounced during short feeding periods because of higher chlorophenol peak concentrations in the reactor. The competitive inhibition constant (K(ii)) of 2,4-DCP on 4-CP degradation was 0.17 mg l(-1) when the reactor was fed instantaneously (0 h feeding). During longer feedings, increased removal/loading rates led to lower chlorophenol peak concentrations at the end of feeding. Therefore, in multi-substrate systems feeding time plus reaction time should be determined based on both degradation kinetics and substrate interaction. During degradation, the meta cleavage of 4-chlorocatechol resulted in accumulation of a yellowish color because of the formation of 5-chloro-2-hydroxymuconic semialdehyde (CHMS), which was further metabolized. Isolation and enrichment of the chlorophenols-degrading culture suggested Pseudomonas sp. and Pseudomonas stutzeri to be the

  13. 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…

  14. Photoelectron spectroscopy of higher bromine and iodine oxide anions: Electron affinities and electronic structures of BrO2,3 and IO2-4 radicals.

    SciTech Connect

    Wen, Hui; Hou, Gaolei; Huang, Wei; Govind, Niranjan; Wang, Xue B.

    2011-11-14

    This report details a photoelectron spectroscopy (PES) investigation on electron affinities (EAs) and electronic structures of several atmospherically relevant higher bromine and iodine oxide molecules in the gas phase. PES spectra of BrO{sub 2}{sup -} and IO{sub 2}{sup -} were recorded at 12 K and four photon energies--355 nm/3.496 eV, 266 nm/4.661 eV, 193 nm/6.424 eV, and 157 nm/7.867 eV--while BrO{sub 3}{sup -}, IO{sub 3}{sup -}, and IO{sub 4}{sup -} were studied at 193 and 157 nm only due to their expected high electron binding energies. Spectral features corresponding to transitions from the anion ground state to the ground and excited states of the neutral are unraveled and resolved for each species. For the first time, EAs of these bromine and iodine oxides are experimentally determined (except for IO{sub 2}) to be 2.515 {+-} 0.010 (BrO{sub 2}), 2.575 {+-} 0.010 (IO{sub 2}), 4.60 {+-} 0.05 (BrO{sub 3}), 4.70 {+-} 0.05 (IO{sub 3}), and 6.05 {+-} 0.05 eV (IO{sub 4}). Three low-lying excited states with their respective excitation energies are obtained for BrO{sub 2} [1.69 (A {sup 2}B2), 1.79 (B {sup 2}A{sub 1}), 1.99 eV (C {sup 2}A{sub 2})], BrO{sub 3} [0.7 (A {sup 2}A{sub 2}), 1.6 (B {sup 2}E), 3.1 eV (C {sup 2}E)], and IO{sub 3} [0.60 (A {sup 2}A{sub 2}), 1.20 (B {sup 2}E), {approx}3.0 eV (C {sup 2}E)], whereas six excited states of IO{sub 2} are determined with the respective excitation energies of 1.63 (A {sup 2}B{sub 2}), 1.73 (B {sup 2}A{sub 1}), 1.83 (C {sup 2}A{sub 2}), 4.23 (D {sup 2}A{sub 1}), 4.63 (E {sup 2}B{sub 2}), and 5.23 eV (F {sup 2}B{sub 1}). Periodate possesses a very high electron binding energy. Only one excited state feature with 0.95 eV excitation energy is shown in the 157 nm spectrum. The obtained EAs and low-lying excited state information are compared with available theoretical calculations and discussed with their atmospheric implications.

  15. Photoelectron spectroscopy of higher bromine and iodine oxide anions: electron affinities and electronic structures of BrO(2,3) and IO(2-4) radicals.

    PubMed

    Wen, Hui; Hou, Gao-Lei; Huang, Wei; Govind, Niranjan; Wang, Xue-Bin

    2011-11-14

    This report details a photoelectron spectroscopy (PES) and theoretical investigation of electron affinities (EAs) and electronic structures of several atmospherically relevant higher bromine and iodine oxide molecules in the gas phase. PES spectra of BrO(2)(-) and IO(2)(-) were recorded at 12 K and four photon energies--355 nm/3.496 eV, 266 nm/4.661 eV, 193 nm/6.424 eV, and 157 nm/7.867 eV--while BrO(3)(-), IO(3)(-), and IO(4)(-) were only studied at 193 and 157 nm due to their expected high electron binding energies. Spectral features corresponding to transitions from the anionic ground state to the ground and excited states of the neutral are unraveled and resolved for each species. The EAs of these bromine and iodine oxides are experimentally determined for the first time (except for IO(2)) to be 2.515 ± 0.010 (BrO(2)), 2.575 ± 0.010 (IO(2)), 4.60 ± 0.05 (BrO(3)), 4.70 ± 0.05 (IO(3)), and 6.05 ± 0.05 eV (IO(4)). Three low-lying excited states along with their respective excitation energies are obtained for BrO(2) [1.69 (A (2)B(2)), 1.79 (B (2)A(1)), 1.99 eV (C (2)A(2))], BrO(3) [0.7 (A (2)A(2)), 1.6 (B (2)E), 3.1 eV (C (2)E)], and IO(3) [0.60 (A (2)A(2)), 1.20 (B (2)E), ∼3.0 eV (C (2)E)], whereas six excited states of IO(2) are determined along with their respective excitation energies of 1.63 (A (2)B(2)), 1.73 (B (2)A(1)), 1.83 (C (2)A(2)), 4.23 (D (2)A(1)), 4.63 (E (2)B(2)), and 5.23 eV (F (2)B(1)). Periodate (IO(4)(-)) possesses a very high electron binding energy. Only one excited state feature with 0.95 eV excitation energy is shown in the 157 nm spectrum. Accompanying theoretical calculations reveal structural changes from the anions to the neutrals, and the calculated EAs are in good agreement with experimentally determined values. Franck-Condon factors simulations nicely reproduce the observed vibrational progressions for BrO(2) and IO(2). The low-lying excited state information is compared with theoretical calculations and discussed with their

  16. 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

  17. 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

  18. 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…

  19. 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…

  20. 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…

  1. Radiolytic oxidation of 1,2,4-benzenetriol. An application of time-resolved resonance Raman spectroscopy to kinetic studies of reaction intermediates

    SciTech Connect

    Qin, L.; Tripathi, G.N.R.; Schuler, R.H.

    1987-03-26

    In acidic solution, 1,2,4-benzenetriol is rapidly oxidized by OH or N/sub 3/ to form a mixture of neutral 2,4- and 3,4-dihydroxyphenoxyl radicals. At higher pH these radicals deprotonate (pK/sub a/(1) = 4.75) to form the 2-hydroxy-p-benzosemiquinone radical anion which exhibits a prominent resonance Raman band at 1625 cm/sup -1/ attributable to the Wilson 8a ring stretching mode. In basic solutions this radical subsequently reacts with OH/sup -/ to form the radical dianion (pK/sub a/(2) = 8.85) in which the 8a band is shifted to an appreciably lower frequency (1587 cm/sup -1/). While the absorption spectra of these latter radicals are very similar and do not allow ready examination of their interconversion by absorption spectrophotometry, the difference between these 8a frequencies is sufficiently great that the Raman method can be used to examine the acid-base equilibrium between the two forms of the radical and to follow the deprotonation kinetics. It is shown that even at high pH the radical monoanion is initially formed on oxidation by N/sub 3/ and that deprotonation subsequently occurs by its reaction with base with a rate constant of (9.6 +/- 1.5) x 10/sup 9/ M/sup -1/ d/sup -1/. These studies illustrate very well the application of time-resolved resonance Raman spectroscopy as a complement to kinetic spectrophotometry in sorting out the details of secondary processes in pulse radiolysis studies.

  2. 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…

  3. 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…

  4. 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…

  5. Some higher N-substituted 1,3-thiazolidine-2,4-diones and 5,5-diphenylhydantoins, their synthesis and corrosion preventive properties in mineral oil medium

    NASA Astrophysics Data System (ADS)

    Öztürk, Serkan; Yıldırım, Ayhan; Çetin, Mehmet

    2013-01-01

    Some five membered heterocyclic compounds were synthesized by the reaction of 2,4-thiazolidinedione or 5,5-diphenylhydantoin potassium salts with 2-chloro-N-alkylacetamides and alkyl-2-chloroacetates. The structure confirmations of the synthesized compounds were performed by FT-IR, 1H NMR, 13C NMR spectra. The inhibitory effectiveness of the compounds were evaluated against the corrosion of steel strip immersed in water containing paraffin based mineral oil medium in accordance to standard test method. Surface characterization studies of the metal coupons used were performed by SEM analysis and also by the contact angle measurements using the Sessile-Drop method. In addition the 3D image of the metal surface was obtained using optical profilometer. The test results and surface characterization studies showed that all synthesized compounds are excellent corrosion inhibitors in such a water in oil emulsion system.

  6. 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…

  7. 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.

  8. 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.

  9. 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.

  10. 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…

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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…

  17. 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…

  18. 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…

  19. Variability analysis of SAR from 20 MHz to 2.4 GHz for different adult and child models using finite-difference time-domain

    NASA Astrophysics Data System (ADS)

    Conil, E.; Hadjem, A.; Lacroux, F.; Wong, M. F.; Wiart, J.

    2008-03-01

    This paper deals with the variability of body models used in numerical dosimetry studies. Six adult anthropomorphic voxel models have been collected and used to build 5-, 8- and 12-year-old children using a morphing method respecting anatomical parameters. Finite-difference time-domain calculations of a specific absorption rate (SAR) have been performed for a range of frequencies from 20 MHz to 2.4 GHz for isolated models illuminated by plane waves. A whole-body-averaged SAR is presented as well as the average on specific tissues such as skin, muscles, fat or bones and the average on specific parts of the body such as head, legs, arms or torso. Results point out the variability of adult models. The standard deviation of whole-body-averaged SAR of adult models can reach 40%. All phantoms are exposed to the ICNIRP reference levels. Results show that for adults, compliance with reference levels ensures compliance with basic restrictions, but concerning children models involved in this study, the whole-body-averaged SAR goes over the fundamental safety limits up to 40%. For more information on this article, see medicalphysicsweb.org

  20. 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…

  1. 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,"…

  2. 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…

  3. 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…

  4. 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…

  5. 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…

  6. Real-time Characterization of Near-Earth Objects: New Spectral Capabilities at the Magdalena Ridge Observatory 2.4-meter

    NASA Astrophysics Data System (ADS)

    Ryan, William; Ryan, Eileen V.; Johnson, Lee K.

    2014-11-01

    Researchers at the Magdalena Ridge Observatory's (MRO) 2.4-meter telescope facility have been contributing to the Near-Earth Object (NEO) project by working in tandem with discovery survey programs since 2008 to provide real-time, rapid response astrometric and photometric characterization follow-up (i.e., lightcurves to deduce spin rates). We are now extending this to include rapid spectroscopic follow-up using the Magdalena Optical Spectroscopy System (MOSS). This 300 visible wavelength spectrometer is permanently mounted at the Nasmyth port opposite the imager port (CCD camera) and is accessible in 30 seconds via repositioning of a tertiary mirror. A second spectroscopic capability is available via a simple filter wheel-mounted grating when MOSS is not in use. By having these instruments mounted (CCD, spectrometer, and stand alone grating) while performing our normal astrometric follow-up tasks, determination of rotation rates and spectral classification are possible as soon as an interesting target is identified, even within minutes of discovery.We report on the first spectral characterization results of NEOs utilizing this new capability at MRO. In particular, we will present spectra for the Sq/Q-type asteroids 2010 XZ67 and 2000 DK79; and the more S-like 2012 HM. In addition, we will present the near simultaneous lightcurve and spectral observations of 2014 EC. The lightcurve observations reveal a period of 0.54 +/- 0.01 hours that hint at non-principle axis rotation. The MOSS-acquired spectra imply its spectral class is Sq/Q as well. A simple grating spectrum of this object was also obtained and was of sufficient quality to corroborate an Sq/Q classification. As an ancillary benefit, this demonstrates that the grating technique can be reliable for rough classification of targets-of-opportunity when it is the only instrumentation option available.

  7. 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.

  8. 2,4-Diaminotoluene

    Integrated Risk Information System (IRIS)

    2,4 - Diaminotoluene ; CASRN 95 - 80 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  9. 2,4-Dichlorophenol

    Integrated Risk Information System (IRIS)

    2,4 - Dichlorophenol ; CASRN 120 - 83 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

  10. 2,4-Dinitrophenol

    Integrated Risk Information System (IRIS)

    2,4 - Dinitrophenol ; CASRN 51 - 28 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  11. 2,4-Dinitrotoluene

    Integrated Risk Information System (IRIS)

    2,4 - Dinitrotoluene ; CASRN 121 - 14 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

  12. 2,4-Dimethylphenol

    Integrated Risk Information System (IRIS)

    2,4 - Dimethylphenol ; CASRN 105 - 67 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

  13. 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)

  14. 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

  15. 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.…

  16. 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…

  17. Soil matrix and macropore biodegradation of 2,4-D

    SciTech Connect

    Pivetz, B.E.; Steenhuis, T.S.

    1995-07-01

    Preferential flow of pesticides in macropores can lead to decreased travel times through the vadose zone and increased groundwater contamination. Macropores, however, may present a favorable environment for biodegradation because of greater oxygen, nutrient, and substrate supply, and higher microbial populations in earthworm burrows, compared to the soil matrix. The biodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was measured in macropores and soil matrix of packed soil columns (7.0-cm diam., 10-cm length) and undisturbed cores contained as well-defined artificial macropore and the undisturbed cores contained earthworm-burrow macropores. A 50 {mu}g/L 2,4-D solution was continuously applied to the unsaturated soil surface and breakthrough curves (BTCs) indicating pesticide loss in the effluent were obtained from the soil matrix and macropore flow paths. Biodegradation rates were calculated separately for each flow path by comparing the BTCs to BTCs representing abiotic conditions, and dividing the 2,4-D loss by the travel time through each flow path. The biodegradation rates increased with time in both flow paths, and the final biodegradation rate in the macropore region surpassed that of the matrix, presumably because of increased microbial populations in the macropore. Complete loss of the 2,4-D in both flow paths was observed after continuous application of 2,4-D for 400 h, with maximum column-averaged 2,4-D loss rates of 0.879 {mu}g/(L h) in the matrix and 1.073 {mu}g/(L h) in the macropore. Biodegradation of 2,4-D was also observed in the macropore and matrix regions of the undisturbed soil cores. 19 refs., 7 figs., 2 tabs.

  18. Stark-assisted population control of coherent CS(2) 4f and 5p Rydberg wave packets studied by femtosecond time-resolved photoelectron spectroscopy.

    PubMed

    Knappenberger, Kenneth L; Lerch, Eliza-Beth W; Wen, Patrick; Leone, Stephen R

    2007-09-28

    A two-color (3+1(')) pump-probe scheme is employed to investigate Rydberg wave packet dynamics in carbon disulfide (CS(2) (*)). The state superpositions are created within the 4f and 5p Rydberg manifolds by three photons of the 400 nm pump pulse, and their temporal evolution is monitored with femtosecond time-resolved photoelectron spectroscopy using an 800 nm ionizing probe pulse. The coherent behavior of the non-stationary superpositions are observed through wavepacket revivals upon ionization to either the upper (12) or lower (32) spin-orbit components of CS(2) (+). The results show clearly that the composition of the wavepacket can be efficiently controlled by the power density of the excitation pulse over a range from 500 GWcm(2) to 10 TWcm(2). The results are consistent with the anticipated ac-Stark shift for 400 nm light and demonstrate an effective method for population control in molecular systems. Moreover, it is shown that Rydberg wavepackets can be formed in CS(2) with excitation power densities up to 10 TWcm(2) without significant fragmentation. The exponential 1e population decay (T(1)) of specific excited Rydberg states are recovered by analysis of the coherent part of the signal. The dissociation lifetimes of these states are typically 1.5 ps. However, a region exhibiting a more rapid decay ( approximately 800 fs) is observed for states residing in the energy range of 74 450-74 550 cm(-1), suggestive of an enhanced surface crossing in this region.

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. Opportunity in Hard Times: Building Out-of-School Time Learning Systems that Last. Report on The Wallace Foundation Conference on Out-of-School Time Learning Washington, D.C.--February 2-4, 2009

    ERIC Educational Resources Information Center

    Mendels, Pamela

    2009-01-01

    A number of U.S. cities, including five supported by Wallace, have been building new systems of high-quality out-of-school time programming citywide. But what should supporters do to ensure that these young systems endure, during the immediate economic crisis and for the long term? This report on a recent Wallace-sponsored conference that gathered…

  4. 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.

  5. 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…

  6. 2,4-Dichlorophenoxyacetic acid (2,4-D)

    Integrated Risk Information System (IRIS)

    2,4 - Dichlorophenoxyacetic acid ( 2,4 - D ) ; CASRN 94 - 75 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Asses

  7. ULO_2.4W

    SciTech Connect

    Pitarka, A.

    2012-03-02

    ULO_2.4W is a computer program that can be used to model elastic wave propagation in heterogeneous media from earthquake (souble couple) point sources. The program is a modified version of the orginal program ULO_2.4 developed by Arben Pitarka. The modifications allow for treatment of solid liquid boundary conditions.

  8. 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

  9. 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,…

  10. 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…

  11. 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…

  12. 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…

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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…

  19. "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…

  20. 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…

  1. 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

  2. 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…

  3. 1,2,4-Tribromobenzene

    Integrated Risk Information System (IRIS)

    1,2,4 - Tribromobenzene ; CASRN 615 - 54 - 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 the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcin

  4. 2,4,5-Trichlorophenol

    Integrated Risk Information System (IRIS)

    2,4,5 - Trichlorophenol ; CASRN 95 - 95 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcino

  5. 1,2,4-Trichlorobenzene

    Integrated Risk Information System (IRIS)

    1,2,4 - Trichlorobenzene ; CASRN 120 - 82 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarci

  6. 2,2,4-Trimethylpentane

    Integrated Risk Information System (IRIS)

    2,2,4 - Trimethylpentane ; CASRN 540 - 84 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarci

  7. 2,4,6-Trichlorophenol

    Integrated Risk Information System (IRIS)

    2,4,6 - Trichlorophenol ; CASRN 88 - 06 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcino

  8. Time evolution of dynamic shear moduli in a physical gelation process of 1,3:2,4-bis-O-(p-methylbenzylidene)-D-sorbitol in polystyrene melt: Critical exponent and gel strength

    NASA Astrophysics Data System (ADS)

    Takenaka, Mikihito; Kobayashi, Toshiaki; Hashimoto, Takeji; Takahashi, Masaoki

    2002-04-01

    We investigated time evolution of shear moduli in the physical gelation process of 1,3:2,4-bis-O-(p-methylbenzylidene)-D-sorbitol (PDTS) in the polystyrene melt system containing 2.5 wt % of PDTS. At the gel point, storage and loss shear moduli, G' and G″, were described by the power law of frequency ω, G'˜G″˜ωn, with the critical exponent n equal to (2)/(3), in agreement with the value predicted by the percolation theory. The exponent n and the gel strength S at the gel point measured as a function of quench depth ΔT indicated that the fractal network structure of PDTS does not change with ΔT but that the mechanical strength of the network increases with ΔT. Before reaching the gel point, G'(ω) and G″(ω) obtained at various times can be well superposed onto the master curves, indicating that the mechanical as well as structural self-similarity hold in this gelation process.

  9. 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…

  10. 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.

  11. Complexation of Cm(III) and Eu(III) with a hydrophilic 2,6-bis(1,2,4-triazin-3-yl)-pyridine studied by time-resolved laser fluorescence spectroscopy.

    PubMed

    Ruff, Christian M; Müllich, Udo; Geist, Andreas; Panak, Petra J

    2012-12-28

    The complexation of Cm(III) and Eu(III) with 2,6-bis(5,6-di(sulfophenyl)-1,2,4-triazin-3-yl)pyridine (aq-BTP) is studied in water at pH 3.0 applying time-resolved laser fluorescence spectroscopy. With increasing ligand concentration [M(H(2)O)(9-3n)(aq-BTP)(n)] (M = Cm(III)/Eu(III), n = 1, 2, 3) complex species are spectroscopically identified. The conditional stability constants of the M(III) 1 : 3 complex species with aq-BTP are log β(03) = 12.2 for Cm(III) and log β(03) = 10.2 for Eu(III). The complexation reaction is enthalpy- and entropy-driven for both metal ions, while the enthalpy change ΔH(03) is 9.7 kJ mol(-1) more negative for Cm(III); changes in ΔS(03) are marginal. The difference in ΔG(03) of -12.7 kJ mol(-1) between the formation of the [M(aq-BTP)(3)] complexes agrees with aq-BTP's selectivity in liquid-liquid extraction studies. PMID:23018544

  12. Complexation of Cm(III) and Eu(III) with a hydrophilic 2,6-bis(1,2,4-triazin-3-yl)-pyridine studied by time-resolved laser fluorescence spectroscopy.

    PubMed

    Ruff, Christian M; Müllich, Udo; Geist, Andreas; Panak, Petra J

    2012-12-28

    The complexation of Cm(III) and Eu(III) with 2,6-bis(5,6-di(sulfophenyl)-1,2,4-triazin-3-yl)pyridine (aq-BTP) is studied in water at pH 3.0 applying time-resolved laser fluorescence spectroscopy. With increasing ligand concentration [M(H(2)O)(9-3n)(aq-BTP)(n)] (M = Cm(III)/Eu(III), n = 1, 2, 3) complex species are spectroscopically identified. The conditional stability constants of the M(III) 1 : 3 complex species with aq-BTP are log β(03) = 12.2 for Cm(III) and log β(03) = 10.2 for Eu(III). The complexation reaction is enthalpy- and entropy-driven for both metal ions, while the enthalpy change ΔH(03) is 9.7 kJ mol(-1) more negative for Cm(III); changes in ΔS(03) are marginal. The difference in ΔG(03) of -12.7 kJ mol(-1) between the formation of the [M(aq-BTP)(3)] complexes agrees with aq-BTP's selectivity in liquid-liquid extraction studies.

  13. 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

  14. 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.

  15. 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.

  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.; 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.

  17. 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.

  18. 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.

  19. 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.

  20. Removal of 2,4-dichlorophenoxyacetic acid by calcined Zn-Al-Zr layered double hydroxide.

    PubMed

    Chaparadza, Allen; Hossenlopp, Jeanne M

    2011-11-01

    The adsorption equilibrium, kinetics, and thermodynamics of removal of 2,4-dichlorophenoxy-acetic acid (2,4-D) from aqueous solutions by a calcined Zn-Al layered double hydroxide incorporated with Zr(4+) were studied with respect to time, temperature, pH, and initial 2,4-D concentration. Zr(4+) incorporation into the LDH was used to enhance 2,4-D uptake by creating higher positive charges and surface/layer modification of the adsorbent. The LDH was capable of removing up to 98% of 2,4-D from 5 to 400 ppm aqueous at adsorbent dosages of 500 and 5000 mg L(-1). The adsorption was described by a Langmuir-type isotherm. The percentage 2,4-D removed was directly proportional to the adsorbent dosage and was optimized with 8% Zr(4+) ion content, relative to the total metals (Zr(4+)+Al(3+)+Zn(2+)). Selected mass transfer and kinetic models were applied to the experimental data to examine uptake mechanism. The boundary layer and intra-particle diffusion played important roles in the adsorption mechanisms of 2,4-D, and the kinetics followed a pseudo-second order kinetic model with an enthalpy, ΔH(ads) of -27.7±0.9 kJ mol(-1). Regeneration studies showed a 6% reduction in 2,4-D uptake capacity over six adsorption-desorption cycles when exposed to an analyte concentration of 100 ppm.

  1. 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

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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;…

  10. 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…

  11. Mineralization of 2,4-dichlorophenoxyacetic acid (2,4-D) and mixtures of 2,4-D and 2,4,5-trichlorophenoxyacetic acid by Phanerochaete chrysosporium

    SciTech Connect

    Yadav, J.S.; Reddy, C.A. )

    1993-09-01

    2,4-dichloropheonxyacetic Acid (2,4-D) is one of the most commonly used phenoxyalkanoic herbicides for selective control of weeds and for defoliation. Since these toxic chemical are manufactured and used each year in massive quantities, effective handling of their production wastes and the contaminated environment is needed. A number of bacterial general are known to degrade 2,4-D, but no naturally occuring bacterium is know to be capable of mineralizing 2,4,5-trichlorophenoxyacetic acid. Mutual inhibition of degradation has been reported when 2,4-D and 2,4,5-T are presented in a mixture to degrading bacteria. This paper investigates the ability of Pseudomonas chrysosporium to mineralize 2,4-D individually and in combination with 2,4,5-T. Results indicate that P. chrysosporium effectively mineralizes 2,4-D alone as well as in combination with 2,4,5-T. 31 refs., 4 figs., 1 tab.

  12. 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…

  13. Immortalization and characterization of mouse floxed Bmp2/4 osteoblasts

    SciTech Connect

    Wu, Li-An; Yuan, Guohua; Yang, Guobin; Ortiz-Gonzalez, Iris; Yang, Wuchen; Cui, Yong; MacDougall, Mary; Harris, Stephen; Chen, Shuo

    2009-08-14

    Generation of a floxed Bmp2/4 osteoblast cell line is a valuable tool for studying the modulatory effects of Bmp2 and Bmp4 on osteoblast differentiation as well as relevant molecular events. In this study, primary floxed Bmp2/4 mouse osteoblasts were cultured and transfected with simian virus 40 large T-antigen. Transfection was verified by polymerase chain reaction (PCR) and immunohistochemistry. To examine the characteristics of the transfected cells, morphology, proliferation and mineralization were analyzed, expression of cell-specific genes including Runx2, ATF4, Dlx3, Osx, dentin matrix protein 1, bone sialoprotein, osteopontin, osteocalcin, osteonectin and collagen type I was detected. These results show that transfected floxed Bmp2/4 osteoblasts bypassed senescence with a higher proliferation rate, but retain the genotypic and phenotypic characteristics similar to the primary cells. Thus, we for the first time demonstrate the establishment of an immortalized mouse floxed Bmp2/4 osteoblast cell line.

  14. 2,4,6-Triphenylphosphinine and 2,4,6-triphenylposphabarrelene revisited: synthesis, reactivity and coordination chemistry.

    PubMed

    Rigo, M; Sklorz, J A W; Hatje, N; Noack, F; Weber, M; Wiecko, J; Müller, C

    2016-02-01

    The synthesis of 2,4,6-triphenylphosphinine has been revisited and a general protocol for the preparation of such low-coordinate phosphorus compounds in good to excellent yields could be established. This allows to investigate several aspects of the chemistry of 2,4,6-triarylphosphinine, such as the reaction with in situ generated benzyne to give 2,4,6-triphenylphosphabarrelene. The corresponding 2,4,6-triphenylphosphabarrelene-selenide could be characterized crystallographically for the first time and the structural and electronic properties of this cage-compound in comparison to classical triarylphosphines could be evaluated. Moreover, [(L)W(CO)5)] complexes of both 2,4,6-triphenylphosphinine and 2,4,6-triphenylphosphabarrelene were prepared and characterized by means of X-ray crystallography. This allowed for the first time a direct structural comparison of these related phosphorus compounds, coordinated to the same metal fragment.

  15. 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…

  16. 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…

  17. 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…

  18. Oxidative degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) in subcritical and supercritical waters.

    PubMed

    Hashimoto, M; Taniguchi, S; Takanami, R; Giri, R R; Ozaki, H

    2010-01-01

    Presence of chlorinated organic compounds in water bodies has become a concern among governments, health authorities and general public. Oxidation of organic compounds in water under high temperature and pressure is considered as a promising technique, but usefulness of the technique to mineralize 2,4-dichlorophenoxyacetic acid (2,4-D) is not well understood. This article aimed to elucidate degradation characteristics of 2,4-D in both subcritical and supercritical waters by laboratory batch experiments. 2,4-D degradation, total organic carbon (TOC) removal and dechlorination increased with increasing reaction time and temperature especially in subcritical waters, while dechlorination was a major step. 2,4-dichlorophenol (2,4-DCP) and acetic acid were the main degradation intermediates both in subcritical and supercritical waters. Though 2,4-D disappeared almost completely in subcritical waters near critical region ( approximately 99%), significant amounts of TOC and organic chlorine still remained as 2,4-DCP and acetic acid. But TOC removal and dechlorination were significantly enhanced ( approximately 95 and 91% respectively) in supercritical waters. Complete mineralization of 2,4-D in subcritical waters required a considerably longer reaction period, while the mineralization was almost complete within a short reaction period in supercritical waters. This is an important information of practical significance for oxidative degradation of chlorinated pesticides similar to 2,4-D.

  19. 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…

  20. 43 CFR 8365.2-4 - Vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Vehicles. 8365.2-4 Section 8365.2-4 Public... OF THE INTERIOR RECREATION PROGRAMS VISITOR SERVICES Rules of Conduct § 8365.2-4 Vehicles. Unless otherwise authorized, no motor vehicle shall be driven within developed recreation sites or areas except...

  1. Fungal bioconversion of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenol (2,4-DCP).

    PubMed

    Vroumsia, T; Steiman, R; Seigle-Murandi, F; Benoit-Guyod, J-L

    2005-09-01

    Ninety strains of fungi from the collection of our mycology laboratory were tested in Galzy and Slonimski (GS) synthetic liquid medium for their ability to degrade the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and its by-product, 2,4-dichlorophenol (2,4-DCP) at 100 mg l(-1), each. Evolution of the amounts of each chemical in the culture media was monitored by HPLC. After 5 days of cultivation, the best results were obtained with Aspergillus penicilloides and Mortierella isabellina for 2,4-D and with Chrysosporium pannorum and Mucor genevensis for 2,4-DCP. The data collected seemed to prove, on one hand, that the strains responses varied with the taxonomic groups and the chemicals tested, and, on the other hand, that 2,4-D was less accessible to fungal degradation than 2,4-DCP. In each case, kinetics studies with the two most efficient strains revealed that there was a lag phase of 1 day before the onset of 2,4-D degradation, whereas there was none during 2,4-DCP degradation. Moreover, 2,4-DCP was detected transiently during 2,4-D degradation. Finally, M. isabellina improved its degradation potential in Tartaric Acid (TA) medium relative to GS and Malt Extract (ME) media.

  2. 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.…

  3. 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…

  4. 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.

  5. 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…

  6. 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.…

  7. 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…

  8. 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…

  9. 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…

  10. 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,…

  11. 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…

  12. 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…

  13. 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…

  14. Biological and molecular responses of Chironomus riparius (Diptera, Chironomidae) to herbicide 2,4-D (2,4-dichlorophenoxyacetic acid).

    PubMed

    Park, Kiyun; Park, Jungan; Kim, Jongkyu; Kwak, Inn-Sil

    2010-05-01

    2,4-Dichlorophenoxyacetic acid (2,4-D) is an agricultural contaminant found in rural ground water. It remains to be determined whether neither 2,4-D poses environmental risks, nor is the mechanism of toxicity known at the molecular level. To evaluate the potential ecological risk of 2,4-D, we assessed the biological parameters including the survival rate, adult sex ratio of emerged adults, and mouthpart deformities in Chironomus riparius after long-term exposure to 2,4-D. The larvae were treated with 0.1, 1 or, 10microgL(-1) of 2,4-D for short- and long-term exposure periods. The sex ratio was changed in C. riparius exposed to only 10microgL(-1) of 2,4-D, whereas mouthpart deformities were observed as significantly higher in C. riparius exposed to 0.1microgL(-1) of 2,4-D. Survival rates were not significantly affected by 2,4-D. Furthermore, we evaluated the molecular and biochemical responses of biomarker genes such as gene expression of heat shock proteins (HSPs), ferritins and glutathione S-transferases (GSTs) in C. riparius exposed to 2,4-D for 24h. The expressions of HSP70, HSP40, HSP90 and GST levels in C. riparius were significantly increased after exposure to a 10microgL(-1) concentration of 2,4-D, whereas ferritin heavy and light chain gene expressions were significantly increased at all concentrations of 2,4-D exposure. Finally, these results may provide an important contribution to our understanding of the toxicology of 2,4-D herbicide in C. riparius. Moreover, the 2,4-D-mediated gene expressions may be generated by 2,4-D is the causative effects on most probable cause of the observed alterations. These biological, molecular and morphological parameters and the measured parameters can be used to monitor 2,4-D toxicity in an aquatic environment.

  15. 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.

  16. 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…

  17. 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…

  18. 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

  19. 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.

  20. Residues of 2, 4-D in air samples from Saskatchewan: 1966-1975.

    PubMed

    Grover, R; Kerr, L A; Wallace, K; Yoshida, K; Maybank, J

    1976-01-01

    Residues of 2,4-D (2,4-dichlorophenoxyacetic acid) in air samples from several sampling sites in central and southern Saskatchewan during the spraying seasons in the 1966-68 and 1970-75 periods were determined by gas-liquid chromatographic techniques. Initially, individual esters of 2,4-D were characterized by retention times and confirmed further by co-injection and dual column procedures. Since 1973, however, only total 2,4-D acid levels in air samples have been determined after esterification to the methyl ester and confirmed by gc/ms techniques whenever possible. Up to 50% of the daily samples collected during the spraying season at any of the locations and during any given year contained 2,4-D, with butyl esters being found most frequently. The daily 24-hr mean atmospheric concentrations of 2,4-D ranged from 0.01 to 1.22 mug/m3, 0.01 to 13.50 mug/m3, and 0.05 to 0.59 mug/m3 for the iso-propyl, mixed butyl and iso-octyl esters, respectively. Even when the samples were analysed for the total 2,4-D content, i.e. from 1973 onwards, the maximum level of the total acid reached only 23.14 mug/m3. In any given year and at any of the sampling sites, about 30% of the samples contained less than 0.01 mug/m3 of 2,4-D. In another 40% of the samples, the levels of 2,4-D ranged from 0.01 to 0.099 mug/m3. Only about 30% of the samples contained 2,4-D concentrations higher than 0.1 mug/m3, with only 10% or less exceeding 1 mug/m3. None of the samples, obtained with the high volume particulate sampler, showed any detectable levels of 2,4-D, indicating little or no transport of 2,4-D adsorbed on dust particles or as crystals of amine salts. PMID:1002953

  1. 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…

  2. 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

  3. 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…

  4. 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…

  5. 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…

  6. Bacterial metabolism of 2,4-dichlorophenoxyacetate

    PubMed Central

    Evans, W. C.; Smith, B. S. W.; Fernley, H. N.; Davies, J. I.

    1971-01-01

    1. Two Pseudomonas strains isolated from soil metabolized 2,4-dichlorophenoxyacetate (2,4-D) as sole carbon source in mineral salts liquid medium. 2. 2,4-Dichlorophenoxyacetate cultures of Pseudomonas I (Smith, 1954) contained 2,4-dichlorophenol, 2-chlorophenol, 3,5-dichlorocatechol and α-chloromuconate, the last as a major metabolite. 3. Dechlorination at the 4(p)-position of the aromatic ring must therefore take place at some stages before ring fission. 4. Pseudomonas N.C.I.B. 9340 (Gaunt, 1962) cultures metabolizing 2,4-dichlorophenoxyacetate contained 2,4-dichloro-6-hydroxyphenoxyacetate, 2,4-dichlorophenol, 3,5-dichlorocatechol and an unstable compound, probably αγ-dichloromuconate. 5. Cell-free extracts of the latter organism grown in 2,4-dichlorophenoxyacetate cultures contained an oxygenase that converted 3,5-dichlorocatechol into αγ-dichloromuconate, a chlorolactonase that in the presence of Mn2+ ions converted the dichloromuconate into γ-carboxymethylene-α-chloro-Δαβ-butenolide, and a delactonizing enzyme that gave α-chloromaleylacetate from this lactone. 6. Pathways of metabolism of 2,4-dichlorophenoxyacetate are discussed. PMID:5123888

  7. 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

  8. Escherichia coli bioreporters for the detection of 2,4-dinitrotoluene and 2,4,6-trinitrotoluene.

    PubMed

    Yagur-Kroll, Sharon; Lalush, Chaim; Rosen, Rachel; Bachar, Neta; Moskovitz, Yaara; Belkin, Shimshon

    2014-01-01

    The primary explosive found in most land mines, 2,4,6-trinitrotoluene (2,4,6-TNT), is often accompanied by 2,4-dinitrotoluene (2,4-DNT) and 1,3-dinitrobenzene (1,3-DNB) impurities. The latter two compounds, being more volatile, have been reported to slowly leak through land mine covers and permeate the soil under which they are located, thus serving as potential indicators for buried land mines. We report on the construction of genetically engineered Escherichia coli bioreporter strains for the detection of these compounds, based on a genetic fusion between two gene promoters, yqjF and ybiJ, to either the green fluorescent protein gene GFPmut2 or to Photorhabdus luminescens bioluminescence luxCDABE genes. These two gene promoters were identified by exposing to 2,4-DNT a comprehensive library of about 2,000 E. coli reporter strains, each harboring a different E. coli gene promoter controlling a fluorescent protein reporter gene. Both reporter strains detected 2,4-DNT in an aqueous solution as well as in vapor form or when buried in soil. Performance of the yqjF-based sensor was significantly improved in terms of detection threshold, response time, and signal intensity, following two rounds of random mutagenesis in the promoter region. Both yqjF-based and ybiJ-based reporters were also induced by 2,4,6-TNT and 1,3-DNB. It was further demonstrated that both 2,4,6-TNT and 2,4-DNT are metabolized by E. coli and that the actual induction of both yqjF and ybiJ is caused by yet unidentified degradation products. This is the first demonstration of an E. coli whole-cell sensor strain for 2,4-DNT and 2,4,6-TNT, constructed using its own endogenous sensing elements.

  9. 7 CFR 2.4 - General officers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false General officers. 2.4 Section 2.4 Agriculture Office of the Secretary of Agriculture DELEGATIONS OF AUTHORITY BY THE SECRETARY OF AGRICULTURE AND GENERAL..., Education, and Economics; the Under Secretary for Marketing and Regulatory Programs; the Assistant...

  10. 14 CFR 2-4 - Accounting period.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Accounting period. Sec. 2-4 Section Sec. 2... Accounting Provisions Sec. 2-4 Accounting period. (a) The accounting year of each air carrier subject to this... settlement with debtors or creditors. (c) Expenditures incurred during the current accounting year...

  11. 7 CFR 2.4 - General officers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false General officers. 2.4 Section 2.4 Agriculture Office of the Secretary of Agriculture DELEGATIONS OF AUTHORITY BY THE SECRETARY OF AGRICULTURE AND GENERAL... Services; the Under Secretary for Natural Resources and Environment; the Under Secretary for...

  12. 7 CFR 2.4 - General officers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false General officers. 2.4 Section 2.4 Agriculture Office of the Secretary of Agriculture DELEGATIONS OF AUTHORITY BY THE SECRETARY OF AGRICULTURE AND GENERAL..., Nutrition, and Consumer Services; the Under Secretary for Natural Resources and Environment; the...

  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. Impact of continuous and intermittent supply of electric assistance on high-strength 2,4-dichlorophenol (2,4-DCP) degradation in electro-microbial system.

    PubMed

    Cao, Zhanping; Zhang, Minghui; Zhang, Jingli; Zhang, Hongwei

    2016-07-01

    The high-strength 2,4-DCP, which exists in two states: dissolved and colloidal, was studied by a continuously electro-microbial system (CEMS) and an intermittently electro-microbial system (IEMS). The hydrolysis rate of colloidal 2,4-DCP in the IEMS without electric assistance was much higher than that in the CEMS. However, the degradation rate of the dissolved 2,4-DCP and the dissolved intermediates (2-chlorophenol and 4-chlorophenol) in the IEMS without electric assistance were much lower than that in the CEMS. By adjusting the intermittent operation mode, the degradation time of 2,4-DCP was shortened greatly. Microbial characteristics in the CEMS and the IEMS were different. The correlation analysis for the main factors affecting the hydrolysis was performed by SPSS, and it was found that the correlation coefficient (rp) was -0.912 for extracellular polymeric substances (EPS) content, 0.823 for zeta potential and 0.632 for relative hydrophobicity, respectively.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. Kinetic modeling of 2,4-dichlorophenoxyacetic acid (2,4-D) degradation in soil slurry by anodic fenton treatment.

    PubMed

    Kong, Lingjun; Lemley, Ann T

    2006-05-31

    Anodic Fenton treatment (AFT) has been shown to be a promising technology in pesticide wastewater treatment. However, no research has been conducted on the AFT application to contaminated soils. In this study, the 2,4-D degradation kinetics of AFT in a silt loam soil slurry were investigated for the first time, and the effects of various experimental conditions including initial 2,4-D concentration, Fenton reagent delivery rate, amount of humic acid (HA) addition, and pH were examined. The 2,4-D degradation in soil slurry by AFT was found to follow a two-stage kinetic model. During the early stage of AFT (the first 4-5 min), the 2,4-D concentration profile followed a pseudo-first-order kinetic model. In the later stage (typically after 5 or 6 min), the AFT kinetic model provided a better fit. This result is most likely due to the existence of (*)OH scavengers and 2,4-D sorption on soil. The Fe(2+) delivery rate was shown to be a more significant factor in degradation rate than the H(2)O(2) delivery rate when the Fe(2+)/H(2)O(2) ratios were in the range of 1:2 to 1:10. The presence of HA in soil lowered the AFT rate, most probably due to the competition with 2,4-D for consumption of (*)OH and increased sorption of 2,4-D on soil. The optimal pH for 2,4-D degradation in soil slurry by AFT was observed to be in the range of pH 2-3.

  4. Effects of lindane, paraquat, toxaphene, and 2,4,5-trichlorophenoxyacetic acid on mallard embryo development

    USGS Publications Warehouse

    Hoffman, D.J.; Eastin, W.C.

    1982-01-01

    The effects were determined of externally treating mallard (Anas platyrhynchos) eggs with two insecticides (lindane and toxaphene) and two herbicides (paraquat and 2,4,5-T) with formulations and concentrations similar to field applications. Paraquat was the most embryotoxic of the four compounds regardless of the type of vehicle. The LC50 for paraquat was 1.5 lb of active ingredient/ acre in aqueous emulsion and 0.1 lb/acre in the oil vehicle. The other compounds had LC50's that were several orders of magnitude higher. Both paraquat and toxaphene caused some mortality at 1/2 of the field level of application. Paraquat impaired growth and was slightly teratogenic at 1/2 of the field level of application, but required higher concentrations (1.5 to 3 times the field level) to produce brain and visceral defects. Lindane was teratogenic, resulting in multiple defects but only at doses that were greater than five times the field level of application. Toxaphene resulted in defects of the joints at doses close to or exceeding the LC50. The herbicide 2,4,5-T resulted in few toxic effects and relatively few abnormal survivors with gross defects. The overall embryotoxicity with either vehicle was paraquat > lindane > toxaphene > 2,4,5-T on a lb per acre basis. However the potential hazard at exposures of up to five times the field level of application was paraquat > toxaphene; neither lindane nor 2,4,5-T constituted much of a hazard. Both paraquat and lindane were more toxic on a lb-peracre basis when administered in oil vehicle but only paraquat represented a potential hazard at five times the field level of application.

  5. 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.

  6. 1,2,4,5-Tetrachlorobenzene

    Integrated Risk Information System (IRIS)

    1,2,4,5 - Tetrachlorobenzene ; CASRN 95 - 94 - 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 the IRIS assessment development process . Sections I ( Health Hazard Assessments for Nonca

  7. 2,4,6-Trinitrotoluene (TNT)

    Integrated Risk Information System (IRIS)

    2,4,6 - Trinitrotoluene ( TNT ) ; CASRN 118 - 96 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for N

  8. 2,4-/2,6-Dinitrotoluene mixture

    Integrated Risk Information System (IRIS)

    2,4 - / 2,6 - Dinitrotoluene mixture ; no CASRN Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncar

  9. 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…

  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. Reduction and Acetylation of 2,4-Dinitrotoluene by a Pseudomonas aeruginosa Strain

    PubMed Central

    Noguera, D. R.; Freedman, D. L.

    1996-01-01

    Aerobic and anoxic biotransformation of 2,4-dinitrotoluene (DNT) was examined by using a Pseudomonas aeruginosa strain isolated from a plant treating propellant manufacturing wastewater. DNT biotransformation in the presence and absence of oxygen was mostly reductive and was representative of the type of cometabolic transformations that occur when a high concentration of an easily degradable carbon source is present. P. aeruginosa reduced both nitro groups on DNT, with the formation of mainly 4-amino-2-nitrotoluene and 2-amino-4-nitrotoluene and small quantities of 2,4-diaminotoluene. Acetylation of the arylamines was a significant reaction. 4-Acetamide-2-nitrotoluene and the novel compounds 2-acetamide-4-nitrotoluene, 4-acetamide-2-aminotoluene, and 2,4-diacetamidetoluene were identified as DNT metabolites. The biotransformation of 2,4-diaminotoluene to 4-acetamide-2-aminotoluene was 24 times faster than abiotic transformation. 2-Nitrotoluene and 4-nitrotoluene were also reduced to their corresponding toluidines and then acetylated. However, the yield of 4-acetamidetoluene was much higher than that of 2-acetamidetoluene, demonstrating that acetylation at the position para to the methyl group was favored. PMID:16535348

  15. 2,4,5-Trichlorophenoxyacetic acid (2,4,5-T)

    Integrated Risk Information System (IRIS)

    2,4,5 - Trichlorophenoxyacetic acid ( 2,4,5 - T ) ; CASRN 93 - 76 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard

  16. 2(2,4,5-Trichlorophenoxy) propionic acid (2,4,5-TP)

    Integrated Risk Information System (IRIS)

    2 ( 2,4,5 - Trichlorophenoxy ) propionic acid ( 2,4,5 - TP ) ; CASRN 93 - 72 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Hea

  17. 4-(2,4-Dichlorophenoxy)butyric acid (2,4-DB)

    Integrated Risk Information System (IRIS)

    4 - ( 2,4 - Dichlorophenoxy ) butyric acid ( 2,4 - DB ) ; CASRN 94 - 82 - 6 Health assessment information on a chemical substance is included in IRIS only after a comprehensive review of chronic toxicity data by U.S . EPA health scientists from several Program Offices and the Office of Research and

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. Adsorption-desorption behavior of 2,4-D on NCP-modified bentonite and zeolite: implications for slow-release herbicide formulations.

    PubMed

    Bakhtiary, Somayeh; Shirvani, Mehran; Shariatmadari, Hossein

    2013-01-01

    Clay minerals have obtained considerable attention for slow-release formulation of herbicides to increase weed control efficacy and reduce leaching potential and environmental pollution. This study deals with preparing, characterizing and examining the potentials of modified bentonite and zeoilite in adsorption and release of 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide. 2,4-D sorption of the N-cetylpyridinium (NCP)-modified bentonites and zeolites were much higher than those of unmodified substrates. The 2,4-D adsorption capacity of the organo-minerals increased with increasing surfactant loading. Desorption isotherms of 2,4-D did not coincide their corresponding sorption isotherms showing hysteresis. The proportion of 2,4-D released from the organo-minerals after seven desorption cycles varied between 29% and 50% of the total retained herbicide. The sorbed 2,4-D on the adsorbents showed gradual release pattern with time. The release pattern of 2,4-D from NCP-modified bentonite and zeolite, make these synthetic organo-minerals suitable candidate for slow release formulation of 2,4-D.

  3. Hydrophobic metabolites of 2,4-dichlorophenoxyacetic acid (2,4-D) in cultured coconut tissue.

    PubMed

    López-Villalobos, Arturo; Hornung, Roland; Dodds, Peter F

    2004-10-01

    Cultures of inflorescence and plumular tissues of coconut palm (Cocos nucifera L.) were maintained in the presence of the auxin, [14C]2,4-dichlorophenoxyacetic acid (2,4-D), so that its metabolic fate could be studied. Thin layer chromatography of methanol extracts of the plumular tissue showed that four classes of metabolites, as well as the unchanged acid, were recovered in the extract. In inflorescence tissue, only the unchanged acid and the most polar class of metabolites (metabolite I) were recovered. Metabolite I was shown to consist mostly of a mixture of sugar conjugates and metabolite II (the next most polar) was an unidentified basic metabolite. Metabolites III and IV were both novel triacylglycerol analogues in which one of the natural fatty acids was replaced with a chain-elongated form of 2,4-D. Reversed-phase thin layer chromatography was used to identify the 2,4-D-derived acids and it was found that metabolite III contained the 2,4-dichlorophenoxy-moiety attached to a chain-length of between 2 and 12 carbons, whereas metabolite IV contained 12, 14 and 16 carbon chain lengths. In inflorescence tissue, and in plumular tissue at low sucrose or 2,4-D concentrations and after short periods in culture, metabolite I predominated. The other metabolites increased as a percentage when plumular culture was prolonged or when sucrose or 2,4-D concentrations were raised. These changes correlated with better development of the explant.

  4. Biolabeling with 2,4-dichlorophenoxyacetic acid derivatives: the 2,4-D tag.

    PubMed

    Bade, Steffen; Röckendorf, Niels; Franek, Milan; Gorris, Hans H; Lindner, Buko; Olivier, Verena; Schaper, Klaus-Jürgen; Frey, Andreas

    2009-12-01

    Many bioanalytic and diagnostic procedures rely on labels with which the molecule of interest can be tracked in or discriminated from accompanying like substances. Herein, we describe a new labeling and detection system based on derivatives of 2,4-dichlorophenoxyacetic acid (2,4-D) and anti-2,4-D antibodies. The 2,4-D system is highly sensitive with a K(D) of 7 x 10(-11) M for the hapten-antibody pair, can be used on a large variety of biomolecules such as proteins, peptides, carbohydrates, and nucleic acids, is not hampered by endogenous backgrounds because 2,4-D is a xenobiotic, and is robust because 2,4-D is a very stable compound that withstands the conditions of most reactions usually performed on biomolecules. With this unique blend of properties, the 2,4-D system compares favorably with its rivals digoxigenin (DIG)/anti-DIG and biotin/(strept)avidin and provides an interesting and powerful tool in biomolecular labeling.

  5. Shock initiation of 2,4-dinitroimidazole (2,4-DNI)

    SciTech Connect

    Urtiew, P.A.; Tarver, C.M.; Simpson, R.L.

    1995-07-19

    The shock sensitivity of the pressed solid explosive 2,4-dinitroimidazole (2,4-DNI) was determined using the embedded manganin pressure gauge technique. At an initial shock pressure of 2 GPa, several microseconds were required before any exothermic reaction was observed. At 4 GPa, 2,4-DNI reacted more rapidly but did not transition to detonation at the 12 mm deep gauge position. At 6 GPa, detonation occurred in less than 6 mm of shock propagation. Thus, 2,4-DNI is more shock sensitive than TATB-based explosives but is considerably less shock sensitive than HMX-based explosives. An Ignition and Growth reactive flow model for 2,4-DNI based on these gauge records showed that 2,4-DNI exhibits shock initiation characteristics similar to TATB but reacts faster. The chemical structure of 2,4-DNI suggests that it may exhibit thermal decomposition reactions similar to nitroguanine and explosives with similar ring structures, such as ANTA and NTO.

  6. Hydrophobic metabolites of 2,4-dichlorophenoxyacetic acid (2,4-D) in cultured coconut tissue.

    PubMed

    López-Villalobos, Arturo; Hornung, Roland; Dodds, Peter F

    2004-10-01

    Cultures of inflorescence and plumular tissues of coconut palm (Cocos nucifera L.) were maintained in the presence of the auxin, [14C]2,4-dichlorophenoxyacetic acid (2,4-D), so that its metabolic fate could be studied. Thin layer chromatography of methanol extracts of the plumular tissue showed that four classes of metabolites, as well as the unchanged acid, were recovered in the extract. In inflorescence tissue, only the unchanged acid and the most polar class of metabolites (metabolite I) were recovered. Metabolite I was shown to consist mostly of a mixture of sugar conjugates and metabolite II (the next most polar) was an unidentified basic metabolite. Metabolites III and IV were both novel triacylglycerol analogues in which one of the natural fatty acids was replaced with a chain-elongated form of 2,4-D. Reversed-phase thin layer chromatography was used to identify the 2,4-D-derived acids and it was found that metabolite III contained the 2,4-dichlorophenoxy-moiety attached to a chain-length of between 2 and 12 carbons, whereas metabolite IV contained 12, 14 and 16 carbon chain lengths. In inflorescence tissue, and in plumular tissue at low sucrose or 2,4-D concentrations and after short periods in culture, metabolite I predominated. The other metabolites increased as a percentage when plumular culture was prolonged or when sucrose or 2,4-D concentrations were raised. These changes correlated with better development of the explant. PMID:15474562

  7. Molecular Imprinted Polymer of Methacrylic Acid Functionalised β-Cyclodextrin for Selective Removal of 2,4-Dichlorophenol

    PubMed Central

    Surikumaran, Hemavathy; Mohamad, Sharifah; Sarih, Norazilawati Muhamad

    2014-01-01

    This work describes methacrylic acid functionalized β-cyclodextrin (MAA-βCD) as a novel functional monomer in the preparation of molecular imprinted polymer (MIP MAA-βCD) for the selective removal of 2,4-dichlorophenol (2,4-DCP). The polymer was characterized using Fourier Transform Infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) and Field Emission Scanning Electron Microscopy (FESEM) techniques. The influence of parameters such as solution pH, contact time, temperature and initial concentrations towards removal of 2,4-DCP using MIP MAA-βCD have been evaluated. The imprinted material shows fast kinetics and the optimum pH for removal of 2,4-DCP is pH 7. Compared with the corresponding non-imprinted polymer (NIP MAA-βCD), the MIP MAA-βCD exhibited higher adsorption capacity and outstanding selectivity towards 2,4-DCP. Freundlich isotherm best fitted the adsorption equilibrium data of MIP MAA-βCD and the kinetics followed a pseudo-second-order model. The calculated thermodynamic parameters showed that adsorption of 2,4-DCP was spontaneous and exothermic under the examined conditions. PMID:24727378

  8. NAS Parallel Benchmarks. 2.4

    NASA Technical Reports Server (NTRS)

    VanderWijngaart, Rob; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    We describe a new problem size, called Class D, for the NAS Parallel Benchmarks (NPB), whose MPI source code implementation is being released as NPB 2.4. A brief rationale is given for how the new class is derived. We also describe the modifications made to the MPI (Message Passing Interface) implementation to allow the new class to be run on systems with 32-bit integers, and with moderate amounts of memory. Finally, we give the verification values for the new problem size.

  9. 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.

  10. 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.

  11. Interaction of 2,4-dichlorophenoxyacetic acid (2,4-D) with cell and model membranes.

    PubMed

    Suwalsky, M; Benites, M; Villena, F; Aguilar, F; Sotomayor, C P

    1996-12-01

    2,4-dichlorophenoxyacetic acid (2,4-D), a widely used herbicide, is a component of the "agent orange' whose toxicity has been extensively studied without definite conclusions. In order to evaluate its perturbing effect upon cell membranes, 2,4-D was made to interact with human erythrocytes and molecular models. These studies were performed by scanning electron microscopy on red cells, fluorescence spectroscopy on dimyristoylphosphatidylcholine (DMPC) large unilamellar vesicles and X-ray diffraction on multilayers of DMPC and dimyristoylphosphatidylethanolamine (DMPE). It was observed that 2,4-D induced a pronounced shape change to the erythrocytes. This effect is explained by the herbicide interaction with the outer monolayer of the red cell membrane. PMID:8972711

  12. 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

  13. Review of 2,4-dichlorophenoxyacetic acid (2,4-D) biomonitoring and epidemiology

    PubMed Central

    Burns, Carol J.; Swaen, Gerard M. H.

    2012-01-01

    A qualitative review of the epidemiological literature on the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and health after 2001 is presented. In order to compare the exposure of the general population, bystanders and occupational groups, their urinary levels were also reviewed. In the general population, 2,4-D exposure is at or near the level of detection (LOD). Among individuals with indirect exposure, i.e. bystanders, the urinary 2,4-D levels were also very low except in individuals with opportunity for direct contact with the herbicide. Occupational exposure, where exposure was highest, was positively correlated with behaviors related to the mixing, loading and applying process and use of personal protection. Information from biomonitoring studies increases our understanding of the validity of the exposure estimates used in epidemiology studies. The 2,4-D epidemiology literature after 2001 is broad and includes studies of cancer, reproductive toxicity, genotoxicity, and neurotoxicity. In general, a few publications have reported statistically significant associations. However, most lack precision and the results are not replicated in other independent studies. In the context of biomonitoring, the epidemiology data give no convincing or consistent evidence for any chronic adverse effect of 2,4-D in humans. PMID:22876750

  14. Review of 2,4-dichlorophenoxyacetic acid (2,4-D) biomonitoring and epidemiology.

    PubMed

    Burns, Carol J; Swaen, Gerard M H

    2012-10-01

    A qualitative review of the epidemiological literature on the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and health after 2001 is presented. In order to compare the exposure of the general population, bystanders and occupational groups, their urinary levels were also reviewed. In the general population, 2,4-D exposure is at or near the level of detection (LOD). Among individuals with indirect exposure, i.e. bystanders, the urinary 2,4-D levels were also very low except in individuals with opportunity for direct contact with the herbicide. Occupational exposure, where exposure was highest, was positively correlated with behaviors related to the mixing, loading and applying process and use of personal protection. Information from biomonitoring studies increases our understanding of the validity of the exposure estimates used in epidemiology studies. The 2,4-D epidemiology literature after 2001 is broad and includes studies of cancer, reproductive toxicity, genotoxicity, and neurotoxicity. In general, a few publications have reported statistically significant associations. However, most lack precision and the results are not replicated in other independent studies. In the context of biomonitoring, the epidemiology data give no convincing or consistent evidence for any chronic adverse effect of 2,4-D in humans.

  15. Advanced oxidation processes for degradation of 2,4-dichlo- and 2,4-dimethylphenol

    SciTech Connect

    Trapido, M.; Veressinina, Y.; Munter, R.

    1998-08-01

    The efficiency of different advanced oxidation processes for degradation of two phenols, 2,4-dimethylphenol (2,4-DMP) and 2,4-dichlorophenol (2,4-DCP), has been under study. Advanced oxidation processes, especially the Fe{sup 2+}/H{sub 2}O{sub 2}/ultraviolet (UV) system, were found to be effective in decomposing phenols and chlorophenols. The degradation rate for 2,4-DCP followed the order, H{sub 2}O{sub 2}/Fe{sup 2+}/UV > H{sub 2}O{sub 2}/Fe{sup 2+} > O{sub 3}/ultrasound (US) > O{sub 3} {ge} O{sub 3}/UV > UV/H{sub 2}O{sub 2} {ge} US > UV. The corresponding order for 2,4-DMP was H{sub 2}O{sub 2}/Fe{sup 2+}/UV > O{sub 3}/US > O{sub 3} {ge} O{sub 3}/UV > H{sub 2}O{sub 2}/Fe{sup 2+} > US {ge} UV/H{sub 2}O{sub 2} > UV. Therefore, the chemical treatment, especially advanced oxidation processes, may be an alternative method for destruction of phenols and purification of wastewaters containing phenolic compounds.

  16. CIRCUIT2. 4. 2-Stage Classification Modeling

    SciTech Connect

    Wilde, R.A. ); Anderson, J.V. )

    1987-12-01

    CIRCUIT2.4 is used to design optimum two-stage classification configurations and operating conditions for energy conservation. It permits simulation of five basic grinding-classification circuits, including one single-stage and four two-stage classification arrangements. Hydrocyclones, spiral classifiers, and sieve band screens can be simulated, and the user may choose the combination of devices for the flowsheet simulation. In addition, the user may select from four classification modeling methods to achieve the goals of a simulation project using the most familiar concepts. Circuit performance is modeled based on classification parameters or equipment operating conditions. A modular approach was taken in designing the program, which allows future addition of other models with relatively minor changes.

  17. 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.

  18. Investigation of the accumulation of 2,4-dichlorophenoxyacetic acid (2,4-D) in rat kidneys.

    PubMed

    Aydin, Handan; Ozdemir, Nurullah; Uzunören, Nuray

    2005-10-01

    The accumulation of 2,4-dichlorophenoxyacetic acid (2,4-D) and its metabolite 2,4-dichlorophenol (2,4-DCP) in the kidneys of rats was investigated. Male and female Sprague-Dawley rats were given 2,4-D in drinking water and food for 30 days. Group A (control group) was fed a normal diet, Group B was fed 50 ppm 2,4-D in 15 g food, Group C received 100 ppm 2,4-D in 15 g food, Group D received 25 ppm 2,4-D in 15 ml drinking water and Group E was given 50 ppm 2,4-D in 15 ml of drinking water. Levels of 2,4-D and 2,4-DCP in kidneys were determined using high performance liquid chromatography (HPLC). It was observed that at low doses of 2,4-D, the metabolite, 2,4-DCP found in the kidneys.

  19. 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…

  20. Biodegradation of phenol, 2,4-DCP, 2,4-D, and 2,4,5-T in field-collected rhizosphere and nonrhizosphere soils

    SciTech Connect

    Boyle, J.J.; Shann, J.R.

    1995-07-01

    This study investigated xenobiotic biodegradation in rhizosphere soil collected from field-grown plants, grouped for analysis as monocots or dicots. Microbial activity was highest in monocot rhizosphere soils, No differences were seen between these soils in the mineralization of phenol or 2,4-dichlorophenol (2,4-DCP), but there were differences in 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) mineralization. The rate constants for 2,4-D or 2,4,5-T mineralization in nonrhizosphere soil. Thus, soils that had a prior association with a plant showed significantly increased rates o mineralization for the more recalcitrant compounds tested. In addition, this enhanced mineralization in the rhizosphere appeared to be dependent on the type of plant involved. 20 refs., 4 figs., 2 tabs.

  1. Detection of 2,4-dinitrotoluene and 2,4,6-trinitrotoluene by an Escherichia coli bioreporter: performance enhancement by directed evolution.

    PubMed

    Yagur-Kroll, Sharon; Amiel, Eden; Rosen, Rachel; Belkin, Shimshon

    2015-09-01

    The use of bacterial bioreporters for the detection of buried landmines and other explosive devices has been promoted for over 25 years, and several bacterial sensor strains capable of detecting traces of either 2,4,6-trinitrotoluene (2,4,6-TNT) or 2,4-dinitrotoluene (2,4-DNT) have since been reported. In all cases, however, detection sensitivity failed to reach the levels required to reliably sense the minute concentrations of 2,4-DNT vapors expected to exist in the soil above buried landmines. Here, we report on the application of a directed evolution process to enhance the performance of a previously described E. coli-based bioreporter harboring a plasmid-borne genetic fusion between the yqjF gene promoter and either luxCDABE or gfp genes, generating bioluminescent or fluorescent signals, respectively, in the presence of either 2,4,6-TNT or its main "signature" compound, 2,4-DNT. We have performed four sequential rounds of random mutagenesis to the yqjF promoter region, yielding a fourth-generation sensor that displayed significantly improved 2,4-DNT detection characteristics compared to the wild-type and to previous generations. Luminescence intensity in the presence of aqueous 2,4-DNT increased over 3000-fold, response ratios were improved over 50-fold, detection threshold was reduced by 75 %, and response time was cut down to half. These features were manifested also upon exposure to 2,4-DNT vapors or to 2,4-DNT and 2,4,6-TNT buried in sand. An analysis of the point mutations accumulated in the course of this process indicated that the major contributors to these effects were manipulations of the -35 element of the yqjF gene promoter.

  2. CAPILLARY ELECTROPHORESIS IMMUNOASSAY FOR 2,4-DICHLOROPHENOXYACETIC ACID

    EPA Science Inventory

    A capillary electrophoresis (CE) immunoassay format for 2,4-dichlorophenoxyacetic acid (2,4-D) is demonstrated. A fluorescent labeled 2,4-D analog competes with the analyte of interest for a finite number of binding sites provided by anti-2,4-D monoclonal antibodies. CE then pr...

  3. Life-stage-, sex-, and dose-dependent dietary toxicokinetics and relationship to toxicity of 2,4-dichlorophenoxyacetic acid (2,4-D) in rats: implications for toxicity test dose selection, design, and interpretation.

    PubMed

    Saghir, Shakil A; Marty, Mary S; Zablotny, Carol L; Passage, Julie K; Perala, Adam W; Neal, Barbara H; Hammond, Larry; Bus, James S

    2013-12-01

    Life-stage-dependent toxicity and dose-dependent toxicokinetics (TK) were evaluated in Sprague Dawley rats following dietary exposure to 2,4-dichlorophenoxyacetic acid (2,4-D). 2,4-D renal clearance is impacted by dose-dependent saturation of the renal organic anion transporter; thus, this study focused on identifying inflection points of onset of dietary nonlinear TK to inform dose selection decisions for toxicity studies. Male and female rats were fed 2,4-D-fortified diets at doses to 1600 ppm for 4-weeks premating, <2 weeks during mating, and to test day (TD) 71 to parental (P1) males and to P1 females through gestation/lactation to TD 96. F1 offspring were exposed via milk with continuing diet exposure until postnatal day (PND) 35. As assessed by plasma area under the curve for the time-course plasma concentration, nonlinear TK was observed ≥ 1200 ppm (63 mg/kg/day) for P1 males and between 200 and 400 ppm (14-27 mg/kg/day) for P1 females. Dam milk and pup plasma levels were higher on lactation day (LD) 14 than LD 4. Relative to P1 adults, 2,4-D levels were higher in dams during late gestation/lactation and postweaning pups (PND 21-35) and coincided with elevated intake of diet/kg body weight. Using conventional maximum tolerated dose (MTD) criteria based on body weight changes for dose selection would have resulted in excessive top doses approximately 2-fold higher than those identified incorporating critical TK data. These data indicate that demonstration of nonlinear TK, if present at dose levels substantially above real-world human exposures, is a key dose selection consideration for improving the human relevance of toxicity studies compared with studies employing conventional MTD dose selection strategies.

  4. 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…

  5. Oxidative degradation of 2,4-xylidine by photosensitization with 2,4,6-triphenylpyrylium: homogeneous and heterogeneous catalysis.

    PubMed

    Amat, Ana M; Arques, Antonio; Bossmann, Stefan H; Braun, André M; Göb, Sabine; Miranda, Miguel A; Oliveros, Esther

    2004-12-01

    The possibility of using zeolites containing the 2,4,6-triphenylpyrylium cation as photocatalysts for the degradation of pollutants has been tested on aqueous xylidine (2,4-dimethylaniline) solutions as models for contaminated wastewaters. The influence of the photocatalyst and substrate concentrations on xylidine oxidation has been investigated in homogeneous solution, by performing a series of experiments chosen according to the experimental design methodology (Doehlert uniform array). The empirical models and the corresponding response surfaces obtained from data analysis have been used for simulating and predicting degradation efficiency. The results have shown that conversion increases with increasing amounts of photocatalyst and decreasing concentration of the model pollutant. The fluorescence of 2,4,6-triphenylpyrylium was quenched by xylidine with a rate constant k(q) of 3.1x10(9)M(-1)s(-1). This result suggests a direct electron transfer between the excited pyrylium salt and xylidine. Because of the limited stability of the photocatalyst in homogeneous media, a pyrylium containing Y-zeolite has been tested for the photocatalytic oxidation of xylidine under heterogeneous conditions. The results suggest that the supported catalyst has a much improved stability and that xylidine oxidation rates remain nearly constant during the whole reaction time. An additional advantage of the pyrylium containing zeolite photocatalyst is that it can be recycled and used for further experiments.

  6. NAS Parallel Benchmarks I/O Version 2.4. 2.4

    NASA Technical Reports Server (NTRS)

    Wong, Parkson; VanderWijngaart, Rob F.; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    We describe a benchmark problem, based on the Block-Tridiagonal (BT) problem of the NAS Parallel Benchmarks (NPB), which is used to test the output capabilities of high-performance computing systems, especially parallel systems. We also present a source code implementation of the benchmark, called NPBIO2.4-MPI, based on the MPI implementation of NPB, using a variety of ways to write the computed solutions to file.

  7. 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,…

  8. 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…

  9. 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…

  10. 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…

  11. 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…

  12. 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,…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. Spatial and temporal variation in type 1 diabetes incidence in Western Australia from 1991 to 2010: increased risk at higher latitudes and over time.

    PubMed

    Ball, Stephen J; Haynes, Aveni; Jacoby, Peter; Pereira, Gavin; Miller, Laura J; Bower, Carol; Davis, Elizabeth A

    2014-07-01

    This study analysed spatial and temporal variation in childhood incidence of type 1 diabetes mellitus (T1DM) among Western Australia׳s 36 Health Districts from 1991 to 2010. There was a strong latitudinal gradient of 3.5% (95% CI, 0.2-7.2) increased risk of T1DM per degree south of the Equator, as averaged across the range 15-35° south. This pattern is consistent with the hypothesis of vitamin D deficiency at higher latitudes. In addition there was a 2.4% (95% CI, 1.3-3.6) average increase in T1DM incidence per year. These effects could not be explained by population density, socioeconomic status, remoteness or ethnicity.

  19. 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.…

  20. Transcriptional expression levels and biochemical markers of oxidative stress in the earthworm Eisenia andrei after exposure to 2,4-dichlorophenoxyacetic acid (2,4-D).

    PubMed

    Hattab, Sabrine; Boughattas, Iteb; Boussetta, Hamadi; Viarengo, Aldo; Banni, Mohamed; Sforzini, Susanna

    2015-12-01

    This study investigated the stress response of earthworms (Eisenia andrei) to exposure to a commonly used herbicide, 2,4 dichloro-phenoxy-acetic acid (2,4-D). We evaluated both stress biomarkers and the transcriptional expression levels and activity of three enzymes involved in oxidative stress responses. Earthworms were exposed to three sublethal concentration of 2,4-D (3.5, 7, and 14 mg kg(-1)) for 7 and 14 days. Exposure to 7 and 14 mg kg(-1) 2,4-D significantly reduced both worm body weight and lysosomal membrane stability (LMS); the latter is a sensitive stress biomarker in coelomocytes. Exposure to 2,4-D caused a pronounced increase in the accumulation of malonedialdehyde (MDA), a marker of oxidative stress, and significantly increased the activity of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD),and glutathione-S-transferase (GST). Compared to expression in controls, the expression levels of the sod, cat, and gst genes increased in worms exposed to all three 2,4-D doses for 7 days. However, after 14 days of exposure, only the expression of the gst gene remained higher than controls. These data provide new insights into the cytotoxicity of 2,4-D in the earthworm E. andrei and should be carefully considered in view of the biological effects of herbicides in soils organisms.

  1. Distribution of 2,4-D in air and on surfaces inside residences after lawn applications: comparing exposure estimates from various media for young children.

    PubMed

    Nishioka, M G; Lewis, R G; Brinkman, M C; Burkholder, H M; Hines, C E; Menkedick, J R

    2001-11-01

    We collected indoor air, surface wipes (floors, table tops, and window sills), and floor dust samples at multiple locations within 11 occupied and two unoccupied homes both before and after lawn application of the herbicide 2,4-D. We measured residues 1 week before and after application. We used collected samples to determine transport routes of 2,4-D from the lawn into the homes, its subsequent distribution between the indoor surfaces, and air concentration as a function of airborne particle size. We used residue measurements to estimate potential exposures within these homes. After lawn application, 2,4-D was detected in indoor air and on all surfaces throughout all homes. Track-in by an active dog and by the homeowner applicator were the most significant factors for intrusion. Resuspension of floor dust was the major source of 2,4-D in indoor air, with highest levels of 2,4-D found in the particle size range of 2.5-10 microm. Resuspended floor dust was also a major source of 2,4-D on tables and window sills. Estimated postapplication indoor exposure levels for young children from nondietary ingestion may be 1-10 microg/day from contact with floors, and 0.2-30 microg/day from contact with table tops. These are estimated to be about 10 times higher than the preapplication exposures. By comparison, dietary ingestion of 2,4-D is approximately 1.3 microg/day.

  2. Distribution of 2,4-D in air and on surfaces inside residences after lawn applications: comparing exposure estimates from various media for young children.

    PubMed Central

    Nishioka, M G; Lewis, R G; Brinkman, M C; Burkholder, H M; Hines, C E; Menkedick, J R

    2001-01-01

    We collected indoor air, surface wipes (floors, table tops, and window sills), and floor dust samples at multiple locations within 11 occupied and two unoccupied homes both before and after lawn application of the herbicide 2,4-D. We measured residues 1 week before and after application. We used collected samples to determine transport routes of 2,4-D from the lawn into the homes, its subsequent distribution between the indoor surfaces, and air concentration as a function of airborne particle size. We used residue measurements to estimate potential exposures within these homes. After lawn application, 2,4-D was detected in indoor air and on all surfaces throughout all homes. Track-in by an active dog and by the homeowner applicator were the most significant factors for intrusion. Resuspension of floor dust was the major source of 2,4-D in indoor air, with highest levels of 2,4-D found in the particle size range of 2.5-10 microm. Resuspended floor dust was also a major source of 2,4-D on tables and window sills. Estimated postapplication indoor exposure levels for young children from nondietary ingestion may be 1-10 microg/day from contact with floors, and 0.2-30 microg/day from contact with table tops. These are estimated to be about 10 times higher than the preapplication exposures. By comparison, dietary ingestion of 2,4-D is approximately 1.3 microg/day. PMID:11713005

  3. 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"…

  4. 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…

  5. Regional water-quality analysis of 2,4-D and dicamba in river water using gas chromatography-isotope dilution mass spectrometry

    USGS Publications Warehouse

    Thurman, E.M.; Zimmerman, L.R.; Aga, D.S.; Gilliom, R.J.

    2001-01-01

    Gas chromatography with isotope dilution mass spectrometry (GC-MS) and enzyme-linked immunosorbent assay (ELISA) were used in regional National Water Quality Assessment studies of the herbicides, 2,4-D and dicamba, in river water across the United States. The GC-MS method involved solid-phase extraction, derivatized with deutemted 2,4-D, and analysis by selected ion monitoring. The ELISA method was applied after preconcentration with solid-phase extraction. The ELISA method was unreliable because of interference from humic substances that were also isolated by solid-phase extraction. Therefore, GC-MS was used to analyzed 80 samples from river water from 14 basins. The frequency of detection of dicamba (28%) was higher than that for 2,4-D (16%). Concentrations were higher for dicamba than for 2,4-D, ranging from less than the detection limit (<0.05 ??g/L) to 3.77 ??g/L, in spite of 5 times more annual use of 2,4-D as compared to dicamba. These results suggest that 2,4-D degrades more rapidly in the environment than dicamba.

  6. Accurate determination of aldehydes in amine catalysts or amines by 2,4-dinitrophenylhydrazine derivatization.

    PubMed

    Barman, Bhajendra N

    2014-01-31

    Carbonyl compounds, specifically aldehydes, present in amine catalysts or amines are determined by reversed-phase liquid chromatography using ultraviolet detection of their corresponding 2,4-dinitrophenylhydrazones. The primary focus has been to establish optimum conditions for determining aldehydes accurately because these add exposure concerns when the amine catalysts are used to manufacture polyurethane products. Concentrations of aldehydes determined by this method are found to vary with the pH of the aqueous amine solution and the derivatization time, the latter being problematic when the derivatization reaction proceeds slowly and not to completion in neutral and basic media. Accurate determination of aldehydes in amines through derivatization can be carried out at an effective solution pH of about 2 and with derivatization time of 20min. Hydrochloric acid has been used for neutralization of an amine. For complete derivatization, it is essential to protonate all nitrogen atoms in the amine. An approach for the determination of an adequate amount of acid needed for complete derivatization has been described. Several 0.2M buffer solutions varying in pH from 4 to 8 have also been used to make amine solutions for carrying out derivatization of aldehydes. These solutions have effective pHs of 10 or higher and provide much lower aldehyde concentrations compared to their true values. Mechanisms for the formation of 2,4-dinitrophenylhydrazones in both acidic and basic media are discussed. PMID:24411140

  7. Screening for fungi intensively mineralizing 2,4,6-trinitrotoluene.

    PubMed

    Scheibner, K; Hofrichter, M; Herre, A; Michels, J; Fritsche, W

    1997-04-01

    Within a screening program, 91 fungal strains belonging to 32 genera of different ecological and taxonomic groups (wood- and litter-decaying basidiomycetes, saprophytic micromycetes) were tested for their ability to metabolize and mineralize 2,4,6-trinitrotoluene (TNT). All these strains metabolized TNT rapidly by forming monoaminodinitrotoluenes (AmDNT). Micromycetes produced higher amounts of AmDNT than did wood- and litter-decaying basidiomycetes. A significant mineralization of [14C]TNT was only observed for certain wood- and litter-decaying basidiomycetes. The most active strains, Clitocybula dusenii TMb12 and Stropharia rugosa-annulata DSM11372 mineralized 42% and 36% respectively of the initial added [14C]TNT (100 microM corresponding to 4.75 microCi/l) to 14CO2 within 64 days. Micromycetes (deuteromycetes, ascomycetes, zygomycetes) proved to be unable to mineralize [14C]TNT significantly.

  8. 28 CFR 2.4 - Same: Youth offenders and juvenile delinquents.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Same: Youth offenders and juvenile delinquents. 2.4 Section 2.4 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND... delinquents may be released on parole at any time in the discretion of the Commission. (18 U.S.C. 5017(a)...

  9. 28 CFR 2.4 - Same: Youth offenders and juvenile delinquents.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Same: Youth offenders and juvenile delinquents. 2.4 Section 2.4 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND... delinquents may be released on parole at any time in the discretion of the Commission. (18 U.S.C. 5017(a)...

  10. 28 CFR 2.4 - Same: Youth offenders and juvenile delinquents.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Same: Youth offenders and juvenile delinquents. 2.4 Section 2.4 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND... delinquents may be released on parole at any time in the discretion of the Commission. (18 U.S.C. 5017(a)...

  11. 28 CFR 2.4 - Same: Youth offenders and juvenile delinquents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Same: Youth offenders and juvenile delinquents. 2.4 Section 2.4 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND... delinquents may be released on parole at any time in the discretion of the Commission. (18 U.S.C. 5017(a)...

  12. A new insensitive explosive that has moderate performance and is low cost: 2,4-Dinitroimidazole

    SciTech Connect

    Simpson, R.; Coon, C.; Foltz, M.

    1995-01-01

    Shock loading experiments were performed on 2,4-Dinitroimidazole. Results indicate that it is a very shock insensitive material. The performance of the material is expected to be 60% greater than TNT. Costs appear to be low but are unresolved at this time. 2,4-DNI may be a realistic alternative to TNT for mass-use bombs.

  13. Stimulation of the faecal excretion of 2,4,5,2',4',5'-hexachlorobiphenyl in rats by squalane.

    PubMed

    Richter, E; Schäfer, S G; Fichtl, B

    1983-06-01

    Faecal excretion of 2,4,5,2',4',5'-hexachlorobiphenyl (6-CB) was followed for 19 weeks in rats fed a control diet, or a squalane-supplemented diet, for up to 17 weeks. In 3 d after a single oral dose of 8 mg/kg of 6-CB, 20% dose was excreted in faeces as unchanged 6-CB, which probably represents that not-absorbed. From day 4 to 133 only an additional 2-4% dose was excreted in faeces by control animals. Addition of 8% squalane to the diet 2, 6 and 15 weeks after dosing resulted in a five-fold increase of daily 6-CB excretion in faeces independent of the time of beginning the treatment. Total excretion of 6-CB in faeces from day 4 to 133 was 3.6, 6-7 and 9.3% dose after 4, 13 and 17 weeks of squalane treatment, respectively. No adverse effects of long-term squalane treatment on body-weight gain, feed efficiency and organ weights were observed. Plasma cholesterol and triglycerides were significantly lowered. Independent of the duration of treatment, the livers of rats fed the squalane-supplemented diet contained 40-50 micrograms/g squalane. Within the limits of detection no squalane could be found in lungs, kidneys, abdominal fat, spleen and blood. It is concluded that 6-CB elimination can be enhanced by oral treatment with squalane even a long time after uptake of the poison. As there was no alteration in the tissue distribution of 6-CB, the 6-CB excreted after squalane treatment probably originates from all tissues.

  14. Response of selenium-dependent glutathione peroxidase in the freshwater bivalve Anodonta woodiana exposed to 2,4-dichlorophenol,2,4,6-trichlorophenol and pentachlorophenol.

    PubMed

    Xia, Xichao; Hua, Chunxiu; Xue, Shipeng; Shi, Bingqin; Gui, Gaixia; Zhang, Dongxian; Wang, Xiying; Guo, Lianghong

    2016-08-01

    2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), and pentachlorophenol (PCP) pose a health risk to aquatic organism and humans, and are recognized as persistent priority pollutants. Selenium dependent glutathione peroxidase (Se-GPx) belongs to the family of selenoprotein, which acts mainly as an antioxidant role in the cellular defense system. In the current study, a Se-GPx full length cDNA was cloned from Anodonta woodiana and named as AwSeGPx. It had a characteristic codon at 165TGA167 that corresponds to selenocysteine(Sec) amino acid as U44. The full length cDNA consists of 870 bp, an open reading frame (ORF) of 585 bp encoded a polypeptide of 195 amino in which conserved domain (68LGFPCNQF75) and a glutathione peroxide-1 GPx active site (32GKVILVENVASLUGTT47) were observed. Additionally, the eukaryotic selenocysteine insertion sequence (SECIS) was conserved in the 3'UTR. The AwSeGPx amino acid sequence exhibited a high similarity with that of other Se-GPx. Real-time PCR analysis revealed that AwSeGPx mRNA had a widely distribution, but the highest level was observed in hepatopancreas. AwSeGPx mRNA expression was significantly up-regulated in hepatopancreas, gill and hemocytes after 2,4-DCP, 2,4,6-TCP and PCP exposure. Under similar environment, clams A. woodiana showed a more sensitive to PCP than that of 2,4-DCP and 2,4,6-TCP. These results indicate that AwSeGPx plays a protective role in eliminating oxidative stress derived from 2,4-DCP, 2,4,6-TCP and PCP treatment. PMID:27291351

  15. 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

  16. 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…

  17. 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…

  18. 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:…

  19. 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…

  20. Synthesis of 1,2,4-Triazoles via Oxidative Heterocyclization: Selective C-N Bond Over C-S Bond Formation.

    PubMed

    Gogoi, Anupal; Guin, Srimanta; Rajamanickam, Suresh; Rout, Saroj Kumar; Patel, Bhisma K

    2015-09-18

    The higher propensity of C-N over C-S bond forming ability was demonstrated, through formal C-H functionalization during the construction of 4,5-disubstituted 1,2,4-triazole-3-thiones from arylidenearylthiosemicarbazides catalyzed by Cu(II). However, steric factors imparted by the o-disubstituted substrates tend to change the reaction path giving thiodiazole as the major or an exclusive product. Upon prolonging the reaction time, the in situ generated thiones are transformed to 4,5-disubstituted 1,2,4-triazoles via a desulfurization process. Two classes of heterocycles viz. 4,5-disubstituted 1,2,4-triazole-3-thiones and 4,5-disubstituted 1,2,4-triazoles can be synthesized from arylidenearylthiosemicarbazides by simply adjusting the reaction time. Desulfurization of 1,2,4-triazole-3-thiones is assisted by thiophilic Cu to provide 1,2,4-triazoles with concomitant formation of CuS and polynuclear sulfur anions as confirmed from scanning electron microscope and energy dispersive X-ray spectroscopy measurements. A one-pot synthesis of an antimicrobial compound has been successfully achieved following this strategy. PMID:26332253

  1. 42 CFR 2.4 - Criminal penalty for violation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Criminal penalty for violation. 2.4 Section 2.4 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS CONFIDENTIALITY OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS Introduction § 2.4 Criminal penalty for violation....

  2. 43 CFR 2920.2-4 - Proposal content.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Proposal content. 2920.2-4 Section 2920.2-4 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT... Easements: General Provisions § 2920.2-4 Proposal content. (a) Proposals for a land use authorization...

  3. 43 CFR 2920.2-4 - Proposal content.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Proposal content. 2920.2-4 Section 2920.2-4 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT... Easements: General Provisions § 2920.2-4 Proposal content. (a) Proposals for a land use authorization...

  4. 10 CFR 960.4-2-4 - Climatic changes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Climatic changes. 960.4-2-4 Section 960.4-2-4 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Postclosure Guidelines § 960.4-2-4 Climatic changes. (a) Qualifying condition. The site shall...

  5. 12 CFR 2.4 - Bonus and incentive plans.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Bonus and incentive plans. 2.4 Section 2.4... § 2.4 Bonus and incentive plans. A bank employee or officer may participate in a bonus or incentive... do not exceed the greater of: (a) Five percent of the recipient's annual salary; or (b) Five...

  6. 42 CFR 2.4 - Criminal penalty for violation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Criminal penalty for violation. 2.4 Section 2.4 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS CONFIDENTIALITY OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS Introduction § 2.4 Criminal penalty for violation....

  7. 42 CFR 2.4 - Criminal penalty for violation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Criminal penalty for violation. 2.4 Section 2.4 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS CONFIDENTIALITY OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS Introduction § 2.4 Criminal penalty for violation....

  8. 42 CFR 2.4 - Criminal penalty for violation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Criminal penalty for violation. 2.4 Section 2.4 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS CONFIDENTIALITY OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS Introduction § 2.4 Criminal penalty for violation....

  9. 43 CFR 2920.2-4 - Proposal content.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Proposal content. 2920.2-4 Section 2920.2-4 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT... Easements: General Provisions § 2920.2-4 Proposal content. (a) Proposals for a land use authorization...

  10. 14 CFR Sec. 2-4 - Accounting period.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Accounting period. Sec. 2-4 Section 2-4... REGULATIONS UNIFORM SYSTEM OF ACCOUNTS AND REPORTS FOR LARGE CERTIFICATED AIR CARRIERS General Accounting Provisions Sec. 2-4 Accounting period. (a) The accounting year of each air carrier subject to this...

  11. 14 CFR Sec. 2-4 - Accounting period.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Accounting period. Sec. 2-4 Section 2-4... REGULATIONS UNIFORM SYSTEM OF ACCOUNTS AND REPORTS FOR LARGE CERTIFICATED AIR CARRIERS General Accounting Provisions Sec. 2-4 Accounting period. (a) The accounting year of each air carrier subject to this...

  12. 14 CFR Sec. 2-4 - Accounting period.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Accounting period. Sec. 2-4 Section 2-4... REGULATIONS UNIFORM SYSTEM OF ACCOUNTS AND REPORTS FOR LARGE CERTIFICATED AIR CARRIERS General Accounting Provisions Sec. 2-4 Accounting period. (a) The accounting year of each air carrier subject to this...

  13. 76 FR 55814 - 2,4-D; Pesticide Tolerances

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-09

    ... AGENCY 40 CFR Part 180 2,4-D; Pesticide Tolerances AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: This regulation establishes tolerances for residues of 2,4-D in or on teff, bran... 180.142 be amended by establishing a tolerance for residues of the herbicide 2,4-D...

  14. 14 CFR Sec. 2-4 - Accounting period.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Accounting period. Sec. 2-4 Section 2-4... REGULATIONS UNIFORM SYSTEM OF ACCOUNTS AND REPORTS FOR LARGE CERTIFICATED AIR CARRIERS General Accounting Provisions Sec. 2-4 Accounting period. (a) The accounting year of each air carrier subject to this...

  15. 43 CFR 2920.2-4 - Proposal content.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Proposal content. 2920.2-4 Section 2920.2-4 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT... Easements: General Provisions § 2920.2-4 Proposal content. (a) Proposals for a land use authorization...

  16. 1 CFR 2.4 - General authority of Director.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 1 General Provisions 1 2010-01-01 2010-01-01 false General authority of Director. 2.4 Section 2.4 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER GENERAL GENERAL INFORMATION § 2.4 General authority of Director. (a) The Director of the Federal Register is delegated authority...

  17. 1 CFR 2.4 - General authority of Director.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 1 General Provisions 1 2011-01-01 2011-01-01 false General authority of Director. 2.4 Section 2.4 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER GENERAL GENERAL INFORMATION § 2.4 General authority of Director. (a) The Director of the Federal Register is delegated authority...

  18. Solid-phase thermal decomposition of 2,4-dinitroimidazole (2,4-DNI)

    SciTech Connect

    Minier, L.; Behrens, R. Jr.; Bulusu, S.

    1996-12-31

    The solid-phase thermal decomposition of the insensitive energetic nitroaromatic heterocycle 2,4-dinitroimidazole (2,4-DNI: mp 265--274C) is studied utilizing simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) between 200 and 247C. The pyrolysis products have been identified using perdeuterated and {sup 15}N-labeled isotopomers. The products consist of low molecular-weight gases and a thermally stable solid residue. The major gaseous products are NO, CO{sub 2}, CO, N{sub 2}, HNCO and H{sub 2}O. Minor gaseous products are HCN, C{sub 2}N{sub 2}, NO{sub 2}, C{sub 3}H{sub 4}N{sub 2}, C{sub 3}H{sub 3}N{sub 3}O and NH{sub 3}. The elemental formula of the residue is C{sub 2}HN{sub 2}O and FTIR analysis suggests that it is polyurea- and polycarbamate-like in nature. Rates of formation of the gaseous products and their respective quantities have been determined for a typical isothermal decomposition experiment at 235C. The temporal behaviors of the gas formation rates indicate that the overall decomposition is characterized by a sequence of four events; (1) an early decomposition period induced by impurities and water, (2) an induction period where C0{sub 2} and NO are the primary products formed at relatively constant rates, (3) an autoacceleratory period that peaks when the sample is depleted and (4) a final period in which the residue decomposes. Arrhenius parameters for the induction period are E{sub a} = 46.9 {plus_minus} 0.7 kcal/mol and Log(A) = 16.3 {plus_minus} 0.3. Decomposition pathways that are consistent with the data are presented.

  19. Solid-phase thermal decomposition of 2,4-dinitroimidazole (2,4-DNI)

    SciTech Connect

    Minier, L.; Behrens, R. Jr.; Bulusu, S.

    1996-07-01

    The solid-phase thermal decomposition of the insensitive energetic aromatic heterocycle 2,4-dinitroimidazole (2,4-DNI: mp 265--274 C) is studied utilizing simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) between 200 and 247 C. The pyrolysis products have been identified using perdeuterated and {sup 15}N-labeled isotopomers. The products consist of low molecular-weight gases and a thermally stable solid residue. The major gaseous products are NO, CO{sub 2}, CO, N{sub 2}, HNCO and H{sub 2}O. Minor gaseous products are HCN, C{sub 2}N{sub 2}, NO{sub 2}, C{sub 3}H{sub 4}N{sub 2}, C{sub 3}H{sub 3}N{sub 3}O and NH{sub 3}. The elemental formula of the residue is C{sub 2}HN{sub 2}O and FTIR analysis suggests that it is polyurea- and polycarbamate-like in nature. The rates of formation of the gaseous products and their respective quantities have been determined for a typical isothermal decomposition experiment at 235 C. The temporal behaviors of the gas formation rates indicate that the overall decomposition is characterized by a sequence of four events: (1) an early decomposition period induced by impurities and H{sub 2}O, (2) an induction period where CO{sub 2} and NO are the primary products formed at relatively constant rates, (3) an autoacceleratory period that peaks when the sample is depleted and (4) a final period in which the residue decomposes. Arrhenius parameters for the induction period are E{sub a} = 46.9 {+-} 0.7 kcal/mol and Log(A) = 16.3 {+-} 0.3. Decomposition pathways that are consistent with the data are presented.

  20. Enhanced electrokinetic dissolution of naphthalene and 2,4-DNT from contaminated soils.

    PubMed

    Jiradecha, Chatdanai; Urgun-Demirtas, Meltem; Pagilla, Krishna

    2006-08-10

    Electrokinetic soil remediation has been proven to remove heavy metals and polar organics from low hydraulic conductivity subsurface environment. In this study, carboxymethyl-beta-cyclodextrin (CMCD) was used as a carrier to assist electrokinetic treatment for removal of low polarity organic contaminants from soils (2.2% organic carbon content). Naphthalene and 2,4-dinitrotoluene (2,4-DNT) were selected as the test compounds. The results from columns experiments showed that 46 and 43% of naphthalene and 2,4-DNT, respectively, were removed using 0.01 N NaNO(3) flushing solution with 40 V electrical potential while 70 and 72% of naphthalene and 2,4-DNT were removed using 2 g/L CMCD solution. Naphthalene and 2,4-DNT removal was enhanced to 83 and 89%, respectively, by using 2 g/L CMCD with 40 V electrical potential. Findings from this study also demonstrated that cyclodextrin assisted electrokinetics can enhance the removal rate of naphthalene and 2,4-DNT. Electric potential applied has more influence on the contaminant removal than the amount of CMCD used. Higher voltage application caused increase in the removal rate of naphthalene and 2,4-DNT, and appeared to be one of the critical factors in obtaining higher contaminant removal while increasing CMCD solution concentration above 2 g/L appeared to have little effect on the contaminant removal. PMID:16359784

  1. Quantification of 2,4-dichlorophenoxyacetic acid in oranges and mandarins by chemiluminescent ELISA.

    PubMed

    Vdovenko, Marina M; Stepanova, Alexandra S; Eremin, Sergei A; Van Cuong, Nguyen; Uskova, Natalia A; Yu Sakharov, Ivan

    2013-11-15

    Direct competitive enzyme-linked immunosorbent assay (ELISA) for 2,4-dichlorophenoxyacetic acid (2,4-D) was developed. Varying the concentrations of monoclonal anti-2,4-D-antibody and the conjugate of soybean peroxidase and 2,4-D the conditions of ELISA performance were optimised. The chemiluminescent method based on peroxidase-catalysed oxidation of luminol was applied to measure the enzyme activity of the conjugate. A mixture of 3-(10'-phenothiazinyl)propane-1-sulfonate and 4-morpholinopyridine was used as potent enhancer of chemiluminescence signal. It was shown that the values of the lower detection limit, IC50 and the working range were 1.5, 64.0, and 6.5-545ng/mL, respectively. The recovery values of CL-ELISA from 10 spiked samples of oranges (n=5) and mandarins (n=5) cultivated in green house without use of 2,4-D and containing different 2,4-D concentrations (10-300ng/mL) were ranged from 92% to 104% that indicated on the absence of matrix effect for the fruit extracts of interest. Determination of 2,4-D in peel of five oranges and five mandarins purchased from stores in Vietnam showed that 2,4-D content in oranges fruits (79-104μg/kg) was significantly higher than that in mandarins (1.66-2.82μg/kg).

  2. 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

  3. Search for factors affecting antibacterial activity and toxicity of 1,2,4-triazole-ciprofloxacin hybrids.

    PubMed

    Plech, Tomasz; Kaproń, Barbara; Paneth, Agata; Kosikowska, Urszula; Malm, Anna; Strzelczyk, Aleksandra; Stączek, Paweł; Świątek, Łukasz; Rajtar, Barbara; Polz-Dacewicz, Małgorzata

    2015-06-01

    A series of 1,2,4-triazole-based compounds was designed as potential antibacterial agents using molecular hybridization approach. The target compounds (23-44) were synthesized by Mannich reaction of 1,2,4-triazole-3-thione derivatives with ciprofloxacin (CPX) and formaldehyde. Their potent antibacterial effect on Gram-positive bacteria was accompanied by similarly strong activity against Gram-negative strains. The toxicity of the CPX-triazole hybrids for bacterial cells was even up to 18930 times higher than the toxicity for human cells. The results of enzymatic studies showed that the antibacterial activity of the CPX-triazole hybrids is not dependent solely on the degree of their affinity to DNA gyrase and topoisomerase IV. PMID:25951434

  4. Biodegradation of 2,4,6-trichlorophenol in a packed-bed biofilm reactor equipped with an internal net draft tube riser for aeration and liquid circulation.

    PubMed

    Jesús, A Gómez-De; Romano-Baez, F J; Leyva-Amezcua, L; Juárez-Ramírez, C; Ruiz-Ordaz, N; Galíndez-Mayer, J

    2009-01-30

    For the aerobic biodegradation of the fungicide and defoliant 2,4,6-trichlorophenol (2,4,6-TCP), a bench-scale packed-bed bioreactor equipped with a net draft tube riser for liquid circulation and oxygenation (PB-ALR) was constructed. To obtain a high packed-bed volume relative to the whole bioreactor volume, a high A(D)/A(R) ratio was used. Reactor's downcomer was packed with a porous support of volcanic stone fragments. PB-ALR hydrodynamics and oxygen mass transfer behavior was evaluated and compared to the observed behavior of the unpacked reactor operating as an internal airlift reactor (ALR). Overall gas holdup values epsilon(G), and zonal oxygen mass transfer coefficients determined at various airflow rates in the PB-ALR, were higher than those obtained with the ALR. When comparing mixing time values obtained in both cases, a slight increment in mixing time was observed when reactor was operated as a PB-ALR. By using a mixed microbial community, the biofilm reactor was used to evaluate the aerobic biodegradation of 2,4,6-TCP. Three bacterial strains identified as Burkholderia sp., Burkholderia kururiensis and Stenotrophomonas sp. constituted the microbial consortium able to cometabolically degrade the 2,4,6-TCP, using phenol as primary substrate. This consortium removed 100% of phenol and near 99% of 2,4,6-TCP. Mineralization and dehalogenation of 2,4,6-TCP was evidenced by high COD removal efficiencies ( approximately 95%), and by the stoichiometric release of chloride ions from the halogenated compound ( approximately 80%). Finally, it was observed that the microbial consortium was also capable to metabolize 2,4,6-TCP without phenol as primary substrate, with high removal efficiencies (near 100% for 2,4,6-TCP, 92% for COD and 88% for chloride ions). PMID:18539387

  5. Biodegradation of 2,4,6-trichlorophenol in a packed-bed biofilm reactor equipped with an internal net draft tube riser for aeration and liquid circulation.

    PubMed

    Jesús, A Gómez-De; Romano-Baez, F J; Leyva-Amezcua, L; Juárez-Ramírez, C; Ruiz-Ordaz, N; Galíndez-Mayer, J

    2009-01-30

    For the aerobic biodegradation of the fungicide and defoliant 2,4,6-trichlorophenol (2,4,6-TCP), a bench-scale packed-bed bioreactor equipped with a net draft tube riser for liquid circulation and oxygenation (PB-ALR) was constructed. To obtain a high packed-bed volume relative to the whole bioreactor volume, a high A(D)/A(R) ratio was used. Reactor's downcomer was packed with a porous support of volcanic stone fragments. PB-ALR hydrodynamics and oxygen mass transfer behavior was evaluated and compared to the observed behavior of the unpacked reactor operating as an internal airlift reactor (ALR). Overall gas holdup values epsilon(G), and zonal oxygen mass transfer coefficients determined at various airflow rates in the PB-ALR, were higher than those obtained with the ALR. When comparing mixing time values obtained in both cases, a slight increment in mixing time was observed when reactor was operated as a PB-ALR. By using a mixed microbial community, the biofilm reactor was used to evaluate the aerobic biodegradation of 2,4,6-TCP. Three bacterial strains identified as Burkholderia sp., Burkholderia kururiensis and Stenotrophomonas sp. constituted the microbial consortium able to cometabolically degrade the 2,4,6-TCP, using phenol as primary substrate. This consortium removed 100% of phenol and near 99% of 2,4,6-TCP. Mineralization and dehalogenation of 2,4,6-TCP was evidenced by high COD removal efficiencies ( approximately 95%), and by the stoichiometric release of chloride ions from the halogenated compound ( approximately 80%). Finally, it was observed that the microbial consortium was also capable to metabolize 2,4,6-TCP without phenol as primary substrate, with high removal efficiencies (near 100% for 2,4,6-TCP, 92% for COD and 88% for chloride ions).

  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. Adsorption of 2,4-Dichlorophenoxyacetic Acid from an Aqueous Solution on Fly Ash.

    PubMed

    Kuśmierek, Krzysztof; Świątkowski, Andrzej

    2016-03-01

    The adsorption of 2,4-dichlorophenoxyacetic acid (2,4-D) on fly ash was studied. The effects of adsorbent dose, contact time, pH, ionic strength, and temperature on the adsorption were investigated. Adsorption kinetic data were analyzed using pseudo-first and pseudo-second order models, and results showed that adsorption kinetics were better represented by the pseudo-second order model. Adsorption isotherms of 2,4-D on fly ash were analyzed using the Freundlich and Langmuir models. Thermodynamic parameters (ΔG°, ΔH°, and ΔS°) indicated that the adsorption process was spontaneous and endothermic. The negative values of ΔG° and the positive value of ΔH° indicate the spontaneous nature of 2,4-D adsorption on fly ash, and that the adsorption process was endothermic. Results showed that fly ash is an efficient, low-cost adsorbent for removal of 2,4-D from water.

  11. Dissipation and residue of 2,4-D in citrus under field condition.

    PubMed

    Chen, Weijun; Jiao, Bining; Su, Xuesu; Zhao, Qiyang; Sun, Dali

    2015-05-01

    The dissipation, residues, and risks of 2,4-dicholrophenoxyacetic acid (2,4-D) in citrus under field condition were investigated based on a simple ultra-performance LC (UPLC)-MS/MS method. The results indicated that the residue level of 2,4-D in citrus did not degrade gradually with sampling time under field condition. At pre-harvest intervals (PHI) of 20-40 days, 2,4-D residues were 0.021-0.269 mg/kg in citrus flesh, 0.028-0.337 mg/kg in whole citrus, and 0.028-0.376 mg/kg in citrus peel, all bellow the China maximum residue limit in citrus (1 mg/kg). Risks of 2,4-D were assessed by calculation of risk quotient, and the results revealed no significant health risks after consumption of citrus.

  12. Killing Weeds with 2,4-D. Extension Bulletin 389.

    ERIC Educational Resources Information Center

    Lee, Oliver C.

    Discussed is the use of the herbicide 2,4-D. Though written for farmers and agricultural workers, the pamphlet considers turf weed control and use of 2,4-D near ornamental plants. Aspects of the use of this herbicide covered are: (1) the common forms of 2,4-D; (2) plant responses and tolerances to the herbicide; (3) dilution and concentration of…

  13. Characterization of 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid-degrading fungi in Vietnamese soils.

    PubMed

    Itoh, Kazuhito; Kinoshita, Masahiro; Morishita, Shigeyuki; Chida, Masateru; Suyama, Kousuke

    2013-04-01

    Sixty-nine fungal strains were isolated countrywide from 10 Vietnamese soils, in areas both with and without a history of exposure to Agent Orange, and their degrading activities on the phenoxy acid herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), as well as related compounds, were examined. Among taxonomically various fungi, 45, 12 and 4% of the isolates degraded phenoxyacetic acid (PA), 2,4-D and 2,4,5-T, respectively. While the PA-degrading fungi were distributed to all sites and among many genera, the 2,4-D-degraders were found only in order Eurotiales in class Eurotiomycetes. All of the 2,4,5-T-degrading fungal strains were phylogenetically close to Eupenicillium spp. and were isolated from southern Vietnam. As a degradation intermediate, the corresponding phenol compounds were detected in some strains. The degradation substrate spectrum for 26 compounds of Eupenicillium spp. strains including 2,4,5-T-degraders and -non-degraders seemed to be related to phylogenetic similarity and soil sampling location of the isolates. These results suggest that the heavily contaminated environments enhanced the adaptation of the phylogenetic group of Eupenicillium spp. toward to obtain the ability to degrade 2,4,5-T. PMID:23167922

  14. Characterization of 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid-degrading fungi in Vietnamese soils.

    PubMed

    Itoh, Kazuhito; Kinoshita, Masahiro; Morishita, Shigeyuki; Chida, Masateru; Suyama, Kousuke

    2013-04-01

    Sixty-nine fungal strains were isolated countrywide from 10 Vietnamese soils, in areas both with and without a history of exposure to Agent Orange, and their degrading activities on the phenoxy acid herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), as well as related compounds, were examined. Among taxonomically various fungi, 45, 12 and 4% of the isolates degraded phenoxyacetic acid (PA), 2,4-D and 2,4,5-T, respectively. While the PA-degrading fungi were distributed to all sites and among many genera, the 2,4-D-degraders were found only in order Eurotiales in class Eurotiomycetes. All of the 2,4,5-T-degrading fungal strains were phylogenetically close to Eupenicillium spp. and were isolated from southern Vietnam. As a degradation intermediate, the corresponding phenol compounds were detected in some strains. The degradation substrate spectrum for 26 compounds of Eupenicillium spp. strains including 2,4,5-T-degraders and -non-degraders seemed to be related to phylogenetic similarity and soil sampling location of the isolates. These results suggest that the heavily contaminated environments enhanced the adaptation of the phylogenetic group of Eupenicillium spp. toward to obtain the ability to degrade 2,4,5-T.

  15. Synthesis, characterization and photophysical studies of a novel schiff base bearing 1, 2, 4-Triazole scaffold

    NASA Astrophysics Data System (ADS)

    Alphonse, Roshmy; Varghese, Anitha; George, Louis

    2016-06-01

    A novel Schiff base derivative containing 1, 2, 4-triazole nucleus (TMPIMP) was synthesized from 4- [1,2,4] triazol-1-ylmethyl-phenylamine and salicylaldehyde in the presence of glacial acetic acid in an ethanolic medium. The synthesized compound was characterized by 1H-NMR, IR and UV spectral analysis. The excitation and emission spectra of triazolyl methyl phenyl imino methyl phenol (abbreviated as TMPIMP) were recorded in various solvents to investigate their solvatochromic behaviour. Dipole moments of the two electronic states of TMPIMP were calculated from solvatochromic spectral shifts. These were correlated with refractive index (η) and dielectric constant (ε) of various solvents. Theoretical calculations were performed to estimate the excited state dipole moment on the basis of different solvent correlation methods, like the Bilot-Kawski, Bakhshiev, Lippert-Mataga, Kawski-Chamma-Viallet and Reichardt methods. The dipole moment in the excited state was found to be higher than that in the ground state due to a substantial redistribution of electron densities and charges. Using a multiple regression analysis, the solvent-solute interactions were determined by means of Kamlet Taft parameters (α, β, π*). Computational studies were performed by Gaussian 09 W software using a time-dependent density functional theory (TD-DFT) in order to calculate the atomic charges and frontier molecular orbital energies in the solvent phase. The calculations indicated that the dipole moment of the molecule in an excited state is much higher than that in a ground state. The chemical stability of TMPIMP was determined by means of chemical hardness (η) using HOMO-LUMO energies. The reactive centers in the molecule were also identified by molecular electrostatic potential (MESP) 3D plots as a result of TD-DFT computational analysis.

  16. Synthesis and Characterization of Molecularly Imprinted Polymer Membrane for the Removal of 2,4-Dinitrophenol

    PubMed Central

    Yusof, Nor Azah; Zakaria, Nor Dyana; Maamor, Nor Amirah Mohd; Abdullah, Abdul Halim; Haron, Md. Jelas

    2013-01-01

    Molecularly imprinted polymers (MIPs) were prepared by bulk polymerization in acetonitrile using 2,4-dinitrophenol, acrylamide, ethylene glycol dimethacrylate, and benzoyl peroxide, as the template, functional monomer, cross-linker, and initiator, respectively. The MIP membrane was prepared by hybridization of MIP particles with cellulose acetate (CA) and polystyrene (PS) after being ground and sieved. The prepared MIP membrane was characterized using Fourier transform infrared spectroscopy and scanning electron microscopy. The parameters studied for the removal of 2,4-dinitrophenol included the effect of pH, sorption kinetics, and the selectivity of the MIP membrane. Maximum sorption of 2,4-nitrophenol by the fabricated CA membrane with MIP (CA-MIP) and the PS membrane with MIP (PS-MIP) was observed at pH 7.0 and pH 5.0, respectively. The sorption of 2,4-dinitrophenol by CA-MIP and PS-MIP followed a pseudo–second-order kinetic model. For a selectivity study, 2,4-dichlorophenol, 3-chlorophenol, and phenol were selected as potential interferences. The sorption capability of CA-MIP and PS-MIP towards 2,4-dinitrophenol was observed to be higher than that of 2,4-dichlorophenol, 3-chlorophenol, or phenol. PMID:23429189

  17. 2,4-Dichlorophenol hydroxylase for chlorophenol removal: Substrate specificity and catalytic activity.

    PubMed

    Ren, Hejun; Li, Qingchao; Zhan, Yang; Fang, Xuexun; Yu, Dahai

    2016-01-01

    Chlorophenols (CPs) are common environmental pollutants. As such, different treatments have been assessed to facilitate their removal. In this study, 2,4-dichlorophenol (2,4-DCP) hydroxylase was used to systematically investigate the activity and removal ability of 19CP congeners at 25 and 0 °C. Results demonstrated that 2,4-DCP hydroxylase exhibited a broad substrate specificity to CPs. The activities of 2,4-DCP hydroxylase against specific CP congeners, including 3-CP, 2,3,6-trichlorophenol, 2-CP, and 2,3-DCP, were higher than those against 2,4-DCP, which is the preferred substrate of previously reported 2,4-DCP hydroxylase. To verify whether cofactors are necessary to promote hydroxylase activity against CP congeners, we added FAD and found that the added FAD induced a 1.33-fold to 5.13-fold significant increase in hydroxylase activity against different CP congeners. The metabolic pathways of the CP degradation in the enzymatic hydroxylation step were preliminarily proposed on the basis of the analyses of the enzymatic activities against 19CP congeners. We found that the high activity and removal rate of 2,4-DCP hydroxylase against CPs at 0 °C enhance the low-temperature-adaptability of this enzyme to the CP congeners; as such, the proposed removal process may be applied to biochemical, bioremediation, and industrial processes, particularly in cold environments.

  18. Fine route for an efficient removal of 2,4-dichlorophenoxyacetic acid (2,4-D) by zeolite-supported TiO2.

    PubMed

    Shankar, M V; Anandan, S; Venkatachalam, N; Arabindoo, B; Murugesan, V

    2006-05-01

    Zeolites HY, Hbeta and HZSM-5 with different physico-chemical properties were chosen as support for TiO2 to illustrate their adsorption, dispersion and electronic structure in photocatalysis. The extent of TiO2 loading was monitored by XRD and BET surface area measurements. The adsorption capacity of HY zeolite was found to be high and hence chosen for further modification to continue the investigation. Photodegradation kinetics were carried out with 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution. The extent of 2,4-D degradation on TiO2/HY loading revealed the importance of adsorption in photocatalysis. Mineralisation studies on all three zeolites with 1 wt.% TiO2 loading demonstrated the good dispersion properties of TiO2/HY. Its photocatalytic activity was found to be excellent with formulated 2,4-D. Comparison of relative photonic efficiencies demonstrated that supported photocatalysts exhibited higher activity than some of the commercial photocatalysts. The high activity of supported TiO2 is due to synergistic effects of improved adsorption of 2,4-D and efficient delocalisation of photogenerated electrons by zeolite support.

  19. Effect of 2,4-D herbicide (2,4-dichlorophenoxyacetic acid) on oxygen consumption and ammonium excretion of juveniles of Geophagus brasiliensis (Quoy & Gaimard, 1824) (Osteichthyes, Cichlidae).

    PubMed

    Barbieri, Edison

    2009-01-01

    Fish form important fisheries and aquaculture resources worldwide. In Brazil, pearl eartheater (Geophagus brasiliensis) is an important commercially exploited species and is an ideal animal for studying the impairment caused by the effects of herbicides that are often detected in the aquatic environment. The main purpose of the present study was to detect the acute toxicity of 2,4-dichlorophenoxyacetic acid (2,4-D) to G. brasiliensis and investigate its effects on oxygen consumption, ammonium excretion, and the neutral red retention time assay to estimate effects at the cellular level. Such investigations have not been carried out before with this species. First, the acute toxicity of 2,4-D to G. brasiliensis in terms of the 24-, 48-, 72-, and 96-h medium lethal concentration (LC(50)) was calculated to be 45.95, 32.49, 28.28, and 15.16 mg/l, respectively. Furthermore, it was found that exposure of fish to 40 mg/l 2,4-D caused reduction in oxygen consumption and ammonium excretion of 59% and 85%, respectively, in relation to the controls. Mean neutral red retention time assay was significantly lower in comparison with control for organisms exposed to 1, 5, 10, and 40 mg/l 2,4-D. However, the effects at the cellular level were progressive, suggesting that the fish are not able to recover from such increasing effects.

  20. Fluorescent caged compounds of 2,4-dichlorophenoxyacetic acid (2,4-d): photorelease technology for controlled release of 2,4-D.

    PubMed

    Atta, Sanghamitra; Jana, Avijit; Ananthakirshnan, Rajakumar; Narayana Dhuleep, Pradeep Singh

    2010-11-24

    A novel controlled-release formulation (CRF) of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was developed to reduce its negative environmental impacts by improving its herbicidal efficacy. The 2,4-D was chemically caged by coupling with photoremovable protecting groups (PRPGs) of coumarin derivatives. Photophysical studies of caged compounds showed that they all exhibited strong fluorescence properties. Controlled release of 2,4-D was achieved by irradiating the caged compounds using UV-vis light (310, 350, and 410 nm). The effect of various factors such as pH, solvent, and different substituents at the seventh position of coumarin moiety on the rate of photorelease was studied. The herbicidal activity of caged compounds and 4-(hydroxymethyl)-7-substituted coumarins was studied against Vigna radiata . The new formulation provided greater control over the release of 2,4-D by UV-vis light and also demonstrated the potential of the PRPGs not only to act as a delivery device but also to possess herbicidal activity after photorelease.

  1. Elimination of 2,4,5,2',4',5'-hexachlorobiphenyl by the purple sea urchin, Strongylocentrotus purpuratus, following single exposure

    SciTech Connect

    Tjeerdema, R.S.; Jacobs, R.S.

    1987-06-01

    Understanding the fate of a single PCB isomer in a resident species may aid in assessing the risk to the marine community. Therefore, the elimination of 2,4,5,2',4',5'-hexachlorobiphenyl (HCBP) by the purple sea urchin, Strongylocentrotus purpuratus, following a single exposure, was investigated. The purple sea urchin was chosen because of its economic importance and ability to proliferate in certain polluted conditions. Single exposure may best mimic the effects of intermittent oceanic incineration or disposal, and 2,4,5,2',4',5'-HCBP was chosen due to its presence in common PCB mixtures and high chlorine content, thus strong lipophilicity.

  2. 36 CFR 2.4 - Weapons, traps and nets.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Weapons, traps and nets. 2.4... PROTECTION, PUBLIC USE AND RECREATION § 2.4 Weapons, traps and nets. (a)(1) Except as otherwise provided in... prohibited: (i) Possessing a weapon, trap or net (ii) Carrying a weapon, trap or net (iii) Using a...

  3. 43 CFR 3811.2-4 - Lands in national forests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Lands in national forests. 3811.2-4... Lands Subject to Location and Purchase § 3811.2-4 Lands in national forests. For mining claims in national forests, see § 3811.1....

  4. 43 CFR 3811.2-4 - Lands in national forests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Lands in national forests. 3811.2-4... Lands Subject to Location and Purchase § 3811.2-4 Lands in national forests. For mining claims in national forests, see § 3811.1....

  5. 43 CFR 3811.2-4 - Lands in national forests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Lands in national forests. 3811.2-4... Lands Subject to Location and Purchase § 3811.2-4 Lands in national forests. For mining claims in national forests, see § 3811.1....

  6. 43 CFR 3811.2-4 - Lands in national forests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Lands in national forests. 3811.2-4... Lands Subject to Location and Purchase § 3811.2-4 Lands in national forests. For mining claims in national forests, see § 3811.1....

  7. 36 CFR 2.4 - Weapons, traps and nets.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Weapons, traps and nets. 2.4... PROTECTION, PUBLIC USE AND RECREATION § 2.4 Weapons, traps and nets. (a)(1) Except as otherwise provided in... prohibited: (i) Possessing a weapon, trap or net (ii) Carrying a weapon, trap or net (iii) Using a...

  8. 36 CFR 2.4 - Weapons, traps and nets.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Weapons, traps and nets. 2.4... PROTECTION, PUBLIC USE AND RECREATION § 2.4 Weapons, traps and nets. (a)(1) Except as otherwise provided in... prohibited: (i) Possessing a weapon, trap or net (ii) Carrying a weapon, trap or net (iii) Using a...

  9. 36 CFR 2.4 - Weapons, traps and nets.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Weapons, traps and nets. 2.4... PROTECTION, PUBLIC USE AND RECREATION § 2.4 Weapons, traps and nets. (a)(1) Except as otherwise provided in... prohibited: (i) Possessing a weapon, trap or net (ii) Carrying a weapon, trap or net (iii) Using a...

  10. 36 CFR 2.4 - Weapons, traps and nets.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Weapons, traps and nets. 2.4... PROTECTION, PUBLIC USE AND RECREATION § 2.4 Weapons, traps and nets. (a)(1) Except as otherwise provided in... prohibited: (i) Possessing a weapon, trap or net (ii) Carrying a weapon, trap or net (iii) Using a...

  11. 43 CFR 5511.2-4 - Timber on withdrawn lands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Timber on withdrawn lands. 5511.2-4... MANAGEMENT, DEPARTMENT OF THE INTERIOR FOREST MANAGEMENT (5000) FREE USE OF TIMBER Free Use Regulations § 5511.2-4 Timber on withdrawn lands. Sections 5511.2-1 to 5511.2-5 are inapplicable to timber...

  12. Toxicological profile for 2,4,6-trinitrotoluene

    SciTech Connect

    1995-11-01

    This Statement was prepared to give you information about 2,4,6-trinitrotoluene and to emphasize the human health effects that may result from exposure to it. The Environmental Protection Agency (EPA) has identified 1,397 sites on its National Priorities List (NPL). 2,4,6-Trinitrotoluene has been found in at least 20 of these sites.

  13. 18 CFR 2.4 - Suspension of rate schedules.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...); Dept. of Energy Organization Act, 42 U.S.C. 7101-7352 (Supp. IV 1980); E.O. 12009, 3 CFR part 142 (1978... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Suspension of rate schedules. 2.4 Section 2.4 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY...

  14. 18 CFR 2.4 - Suspension of rate schedules.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...); Dept. of Energy Organization Act, 42 U.S.C. 7101-7352 (Supp. IV 1980); E.O. 12009, 3 CFR part 142 (1978... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Suspension of rate schedules. 2.4 Section 2.4 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY...

  15. 18 CFR 2.4 - Suspension of rate schedules.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...); Dept. of Energy Organization Act, 42 U.S.C. 7101-7352 (Supp. IV 1980); E.O. 12009, 3 CFR part 142 (1978... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Suspension of rate schedules. 2.4 Section 2.4 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY...

  16. 18 CFR 2.4 - Suspension of rate schedules.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...); Dept. of Energy Organization Act, 42 U.S.C. 7101-7352 (Supp. IV 1980); E.O. 12009, 3 CFR part 142 (1978... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Suspension of rate schedules. 2.4 Section 2.4 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY...

  17. 1 CFR 2.4 - General authority of Director.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 1 General Provisions 1 2012-01-01 2012-01-01 false General authority of Director. 2.4 Section 2.4... General authority of Director. (a) The Director of the Federal Register is delegated authority to... States Code. (b) The Director may return to the issuing agency any document submitted for publication...

  18. 1 CFR 2.4 - General authority of Director.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 1 General Provisions 1 2013-01-01 2012-01-01 true General authority of Director. 2.4 Section 2.4... General authority of Director. (a) The Director of the Federal Register is delegated authority to... States Code. (b) The Director may return to the issuing agency any document submitted for publication...

  19. 1 CFR 2.4 - General authority of Director.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 1 General Provisions 1 2014-01-01 2012-01-01 true General authority of Director. 2.4 Section 2.4... General authority of Director. (a) The Director of the Federal Register is delegated authority to... States Code. (b) The Director may return to the issuing agency any document submitted for publication...

  20. Degradation of 2,4-dichlorophenoxyacetic acid by a halotolerant strain of Penicillium chrysogenum: antibiotic production.

    PubMed

    Ferreira-Guedes, Sumaya; Mendes, Benilde; Leitão, Ana Lúcia

    2012-01-01

    The extensive use of pesticides in agriculture has prompted intensive research on chemical and biological methods in order to protect contamination of water and soil resources. In this paper the degradation of the pesticide 2,4-dichlorophenoxyacetic acid by a Penicillium chrysogenum strain previously isolated from a salt mine was studied in batch cultures. Co-degradation of 2,4-dichlorophenoxyacetic acid with additives such as sugar and intermediates of pesticide metabolism was also investigated. Penicillium chrysogenum in solid medium was able to grow at concentrations up to 1000 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D) with sucrose. Meanwhile, supplementation of the solid medium with glucose and lactose led to fungal growth at concentrations up to 500 mg/L of herbicide. Batch cultures of 2,4-D at 100 mg/L were developed under aerobic conditions with the addition of glucose, lactose and sucrose, showing sucrose as the best additional carbon source. The 2,4-D removal was quantified by liquid chromatography. The fungus was able to use 2,4-D as the sole carbon and energy source under 0%, 2% and 5.9% NaCl. The greatest 2,4-D degradation efficiency was found using alpha-ketoglutarate and ascorbic acid as co-substrates under 2% NaCl at pH 7. Penicillin production was evaluated in submerged cultures by bioassay, and higher amounts of beta-lactam antibiotic were produced when the herbicide was alone. Taking into account the ability of P. chrysogenum CLONA2 to degrade aromatic compounds, this strain could be an interesting tool for 2,4-D herbicide remediation in saline environments. PMID:22629643

  1. Effect of pH and Electrolytes on Adsorption of 2,4-D onto Kaolinite

    NASA Astrophysics Data System (ADS)

    Sharma, A.; Kawamoto, K.; Komatsu, T.; Moldrup, P.

    2006-12-01

    The fate and transport of pesticides in soil can be greatly influenced by adsorption onto clay minerals such as kaolinite. The ionic pesticide 2,4-D (2,4-dichlorophenoxyacetic acid) is one of the most commonly used herbicides. The purpose of this study is to investigate the effect of electrolytes and pH on the adsorption of 2,4- D onto kaolinite. The adsorption coefficient (Kd) of 2,4-D on two types of kaolinite was measured in batch experiments using water and 4 different electrolytes (0.005M CaSO4, 0.005M CaCl2, 0.01M KCl, and 0.01M NaCl). The experiments were carried out with 0.5 g kaolinite at a solid:liquid ratio of 1:20 and at different pH (1.9-6.3). The pH of the solution was controlled by addition of 0.2N of HCl. X-ray diffraction analysis of both kaolinite with and without adsorbed 2,4-D was also done to understand the location of 2,4-D adsorption. The effects of pH and electrolytes on Kd were compared and possible adsorption mechanisms were revealed for 2,4-D adsorption onto the two different types of kaolinite. The results implied that 2,4-D adsorption was higher for an electrolyte solution with monovalent cation than with divalent cation for one type of kaolinite, while no such trend was observed for the other kaolinite. The adsorption of 2,4-D increased significantly with decreasing pH for both types of kaolinite.

  2. Degradation of 2,4-dichlorophenoxyacetic acid by a halotolerant strain of Penicillium chrysogenum: antibiotic production.

    PubMed

    Ferreira-Guedes, Sumaya; Mendes, Benilde; Leitão, Ana Lúcia

    2012-01-01

    The extensive use of pesticides in agriculture has prompted intensive research on chemical and biological methods in order to protect contamination of water and soil resources. In this paper the degradation of the pesticide 2,4-dichlorophenoxyacetic acid by a Penicillium chrysogenum strain previously isolated from a salt mine was studied in batch cultures. Co-degradation of 2,4-dichlorophenoxyacetic acid with additives such as sugar and intermediates of pesticide metabolism was also investigated. Penicillium chrysogenum in solid medium was able to grow at concentrations up to 1000 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D) with sucrose. Meanwhile, supplementation of the solid medium with glucose and lactose led to fungal growth at concentrations up to 500 mg/L of herbicide. Batch cultures of 2,4-D at 100 mg/L were developed under aerobic conditions with the addition of glucose, lactose and sucrose, showing sucrose as the best additional carbon source. The 2,4-D removal was quantified by liquid chromatography. The fungus was able to use 2,4-D as the sole carbon and energy source under 0%, 2% and 5.9% NaCl. The greatest 2,4-D degradation efficiency was found using alpha-ketoglutarate and ascorbic acid as co-substrates under 2% NaCl at pH 7. Penicillin production was evaluated in submerged cultures by bioassay, and higher amounts of beta-lactam antibiotic were produced when the herbicide was alone. Taking into account the ability of P. chrysogenum CLONA2 to degrade aromatic compounds, this strain could be an interesting tool for 2,4-D herbicide remediation in saline environments.

  3. Lunar Occultations of 18 Stellar Sources from the 2.4 m Thai National Telescope

    NASA Astrophysics Data System (ADS)

    Richichi, A.; Tasuya, O.; Irawati, P.; Soonthornthum, B.; Dhillon, V. S.; Marsh, T. R.

    2016-01-01

    We report further results from the program of lunar occultation (LO) observations started at the 2.4 m Thai National Telescope (TNT) in 2014. We have recorded LO events of 18 stellar sources, leading to the detection of four angular diameters and two binary stars. With two exceptions, these are first-time determinations. We could resolve angular diameters as small as 2 milliarcseconds (mas) and projected separations as small as 4 mas. We discuss the individual results, in the context of previous observations, when available. The first-time angular diameters for o Psc, HR 6196 and 75 Leo are in good agreement with expected values, while that of π Leo agrees with the average of previous determinations but has a higher accuracy. We find a new secondary in o Psc, as previously suspected from Hipparcos data. We also obtain an accurate measurement of the companion in 31 Ari, revealing inconsistencies in the currently available orbital parameters. The TNT, equipped with the fast ULTRASPEC imager, is the leading facility in Southeast Asia for high time resolution observations. The LO technique at this telescope achieves a sensitivity of i‧ ≈ 10 mag, with a potential to detect several hundreds of LO events per year.

  4. Removal of 2,4-dichlorophenol from aqueous solution by static-air-activated carbon fibers.

    PubMed

    Wang, Jian-Ping; Chen, Yong-Zhen; Feng, Hui-Min; Zhang, Shu-Juan; Yu, Han-Qing

    2007-09-01

    Static-air-activated carbon fibers (ACFs) with lotus-root-like axially porous structure were used to adsorb 2,4-dichlorophenol (2,4-DCP) from aqueous solution. The adsorption isotherm was evaluated in the pH range 3.0-11.0. Results indicated that both Langmuir and Redlich-Peterson adsorption isotherms were appropriate for describing the adsorption characteristics of 2,4-DCP at various pH values and that lower pH values were favorable for adsorption. The adsorption of 2,4-DCP was controlled by the synergetic effects of pi-pi interaction and electrostatic attraction, and the former was dominant. Breakthrough curve results showed that the 2,4-DCP removal efficiency increased with an increase in the empty-bed contact time (EBCT). An EBCT of 0.660 min was sufficient for the adsorption of 2,4-DCP onto ACF, indicating a high adsorption rate. Desorption experiment results revealed that the ACF saturated with 2,4-DCP could be regenerated effectively by a 0.001 M NaOH solution. PMID:17509602

  5. Phytoremediation potentiality of garlic roots for 2,4-dichlorophenol removal from aqueous solutions.

    PubMed

    Wang, Yan; Zhang, Jun-Xing; Ren, He-Jun; Wang, Ying; Pan, Hong-Yu; Zhang, Lan-Ying

    2015-04-01

    2,4-Dichlorophenol (2,4-DCP) is considered as an important pollutant because of its high toxicity and wide distribution in wastewaters. Innocuous remediation technologies have been studied for the removal of this pollutant. This study investigated the feasibility of using garlic roots as a plant system for the removal of 2,4-DCP. The optimal conditions for its removal were established based on orthogonal experiments (OA25 matrix). Significant factors that affect removal efficiency, arranged from high to low importance, include pH, reaction time, 2,4-DCP concentration, and H2O2 concentration. In addition, garlic roots could be re-used for as much as three consecutive cycles. The decrease in pH and the increase of Cl(-) ion content in the post-removal solutions indicated that 2,4-DCP dehalogenation occurred during transformation. Changes in the deposition pattern of lignin in roots exposed to 2,4-DCP suggested that several of the products deposited were lignin-type polymers. The acute toxicity test revealed that the post-removal solutions were less toxic than the parent solutions. Therefore, garlic roots have considerable potential to effectively and safely remove 2,4-DCP from wastewater.

  6. 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.

  7. 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.

  8. Pristine environments harbor a new group of oligotrophic 2,4-dichlorophenoxyacetic acid-degrading bacteria.

    PubMed Central

    Kamagata, Y; Fulthorpe, R R; Tamura, K; Takami, H; Forney, L J; Tiedje, J M

    1997-01-01

    2,4-Dichlorophenoxyacetic acid (2,4-D)-degrading bacteria were isolated from pristine environments which had no history of 2,4-D exposure. By using 2,4-D dye indicator medium or 14C-labeled 2,4-D medium, six strains were isolated from eight enrichment cultures capable of degrading 2,4-D. Phylogenetic analyses based on 16S ribosomal DNA (rDNA) sequencing and physiological properties revealed that one isolate from Hawaiian volcanic soil could be classified in the genus Variovorax (a member of the beta subdivision of the class Proteobacteria) and that the other five isolates from Hawaiian volcanic soils, Saskatchewan forest soil, and Chilean forest soil have 16S rDNAs with high degrees of similarity to those of the Bradyrhizobium group (a member of the alpha subdivision of the class Proteobacteria). All the isolates grow slowly on either nutrient media (0.1 x Bacto Peptone-tryptone-yeast extract-glucose [PTYG] or 0.1 x Luria broth [LB] medium) or 2,4-D medium, with mean generation times of 16 to 30 h, which are significantly slower than previously known 2,4-D degraders. Nutrient-rich media such as full-strength PTYG and LB medium did not allow their growth. PCR amplification using internal consensus sequences of tfdA (a gene encoding an enzyme for the first step of 2,4-D mineralization, found in pJP4 of Alcaligenes eutrophus JMP134 and some other 2,4-D-degrading bacteria) as primers and Southern hybridization with pJP4-tfdA as a probe revealed that the isolate belonging to the genus Variovorax carried the tfdA gene. This gene was transmissible to A. eutrophus JMP228 carrying a plasmid with a mutant tfdA gene. The other five isolates did not appear to carry tfdA, and 2,4-D-specific alpha-ketoglutarate-dependent dioxygenase activity could not be detected in cell lysates. These results indicate that 2,4-D-degrading bacteria in pristine environments are slow-growing bacteria and that most of their phylogenies and catabolic genes differ from those of 2,4-D degraders

  9. 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.

  10. Effect of 2,4-Dichlorophenoxyacetic acid herbicide Escherichia coli growth, chemical, composition, and cellular envelope

    USGS Publications Warehouse

    Carr, R.S.; Biedenbach, J.M.; Hooten, R.L.

    2001-01-01

    2,4-Dichlorophenoxyacetic acid (2,4-D) is a herbicide widely used in the world and mainly excreted by the renal route in exposed humans and animals. Herbicides can affect other nontarget organisms, such as Escherichia coli. We observed that a single exposure to 1 mM 2,4-D diminished growth and total protein content in all E. coli strains tested in vitro. In addition, successive exposures to 0.01 mM 2,4-D had a toxic effect decreasing growth up to early stationary phase. Uropathogenic E. coli adhere to epithelial cells mediated by fimbriae, adhesins, and hydrophobic properties. 2,4-D exposure of uropathogenic E. coli demonstrated altered hydrophobicity and fimbriation. Hydrophobicity index values obtained by partition in p-xylene/water were 300-420% higher in exposed cells than in control ones. Furthermore, values of hemagglutination titer, protein contents in fimbrial crude extract, and electron microscopy demonstrated a significant diminution of fimbriation in treated cells. Other envelope alterations could be detected, such as lipoperoxidation, evidenced by decreased polyunsaturated fatty acids and increased lipid degradation products (malonaldehyde), and motility diminution. These alterations decreased cell adherence to erythrocytes, indicating a diminished pathogenic capacity of the 2,4-D-exposed E. coli. ?? 2001 by John Wiley & Sons, Inc.

  11. Effects of simulated acid rain and (+/-)-2-(2,4-dichlorophenoxy) propanoic acid on selected crops.

    PubMed

    Larsen, B R

    1985-10-01

    The effect of foliar-applicated (+/-)-2-(2,4-dichlorophenoxy)propanoic acid (2,4-DP) under simultaneous influence of simulated acid rain at pH levels of 3.3, 4.3, and 5.6 was examined for young plants of white mustard, rape, cress, lettuce, radish, carrot, oat, and barley grown in climate chambers. After 1-2 weeks with daily showers plants received a single foliar application of 2,4-DP in aqueous solution (500 microliter; 0.25-50.0 mg X liter-1). After a post-treatment period of 2-3 weeks with daily showers the plants were sampled. 2,4-DP at 5 mg X liter-1 or higher concentrations caused various symptoms for the dicotyledons. Monocotyledons and carrot remained unaffected. The application of acid rain at pH 3.3 produced morphological changes, increased the symptoms from 2,4-DP, and reduced the dry weight and the leaf to stem ratio. Cress exposed only to acid rain showed necrotic spots and chlorosis at pH 3.3. By decreasing pH taller plants with smaller leaves were observed. The combined effect of acid rain and 2,4-DP was additive rather than synergistic.

  12. Fetotoxicity of 2,4-dichlorophenoxyacetic acid in rats and the protective role of vitamin E.

    PubMed

    Mazhar, Fatma M; Moawad, Karima M; El-Dakdoky, Mai H; Amer, Amany S

    2014-06-01

    The present study was conducted to investigate the potential role of 2,4-dichlorophenoxyacetic acid (2,4-D) in inducing developmental toxicity and oxidative damage in pregnant rats and their fetuses as well as to assess the efficacy of vitamin E to prevent or alleviate such defects. Pregnant rats received 2,4-D (100 mg/kg bw) alone or in combination with vitamin E (100 mg/kg bw) daily from gestation day 1 to 19. The number of implantations, viable and resorbed fetuses and sex ratio were not statistically different among groups. However, fetuses maternally treated with 2,4-D were characterized by lower body weight and higher morphologic and skeletal defect rate. 2,4-D induced oxidative stress in the liver of mothers and fetuses which was indicated by a significant elevation of malondialdehyde level with reduction in catalase activity and total antioxidant capacity. Coadministration of vitamin E can counteract the deleterious effects of 2,4-D by successive reduction in the oxidative stress.

  13. Clastogenicity of pentachlorophenol, 2,4-D and butachlor evaluated by Allium root tip test.

    PubMed

    Ateeq, Bushra; Abul Farah, M; Niamat Ali, M; Ahmad, Waseem

    2002-02-15

    The meristematic mitotic cells of Allium cepa is an efficient cytogenetic material for chromosome aberration assay on environmental pollutants. For assessing genotoxicity of pentachlorophenol (PCP), 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-chloro-2,6-diethyl-N-(butoxymethyl) acetanilide (butachlor), 50% effective concentration (EC(50)), c-mitosis, stickiness, chromosome breaks and mitotic index (MI) were used as endpoints of genotoxicity. EC(50) values for PCP and butachlor are 0.73 and 5.13 ppm, respectively. 2,4-D evidently induced morphological changes at higher concentrations. Some changes like crochet hooks, c-tumours and broken roots were unique to 2,4-D at 5-20 ppm. No such abnormalities were found in PCP and butachlor treated groups, however, root deteriorated and degenerated at higher concentrations (<3 ppm) in PCP. MI in 2,4-D showed a low average of 14.32% followed by PCP (19.53%), while in butachlor it was recorded 71.6%, which is near to the control value. All chemicals induced chromosome aberrations at statistically significant level. The highest chromosome aberration frequency (11.90%) was recorded in PCP at 3 ppm. Large number of c-mitotic anaphases indicated that butachlor acts as potent spindle inhibitor, whereas, breaks, bridges, stickiness and laggards were most frequently found in PCP showing that it is a potent clastogen. PMID:11815249

  14. Clastogenicity of pentachlorophenol, 2,4-D and butachlor evaluated by Allium root tip test.

    PubMed

    Ateeq, Bushra; Abul Farah, M; Niamat Ali, M; Ahmad, Waseem

    2002-02-15

    The meristematic mitotic cells of Allium cepa is an efficient cytogenetic material for chromosome aberration assay on environmental pollutants. For assessing genotoxicity of pentachlorophenol (PCP), 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-chloro-2,6-diethyl-N-(butoxymethyl) acetanilide (butachlor), 50% effective concentration (EC(50)), c-mitosis, stickiness, chromosome breaks and mitotic index (MI) were used as endpoints of genotoxicity. EC(50) values for PCP and butachlor are 0.73 and 5.13 ppm, respectively. 2,4-D evidently induced morphological changes at higher concentrations. Some changes like crochet hooks, c-tumours and broken roots were unique to 2,4-D at 5-20 ppm. No such abnormalities were found in PCP and butachlor treated groups, however, root deteriorated and degenerated at higher concentrations (<3 ppm) in PCP. MI in 2,4-D showed a low average of 14.32% followed by PCP (19.53%), while in butachlor it was recorded 71.6%, which is near to the control value. All chemicals induced chromosome aberrations at statistically significant level. The highest chromosome aberration frequency (11.90%) was recorded in PCP at 3 ppm. Large number of c-mitotic anaphases indicated that butachlor acts as potent spindle inhibitor, whereas, breaks, bridges, stickiness and laggards were most frequently found in PCP showing that it is a potent clastogen.

  15. 41 CFR 51-2.4 - Determination of suitability.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Public Contracts COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED 2-COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED § 51-2.4 Determination of suitability. (a) For...

  16. 2. 4 LOGAN CIRCLE, SIDE ELEVATION (Photograph of line drawing ...

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

    2. 4 LOGAN CIRCLE, SIDE ELEVATION (Photograph of line drawing by Turner Associates and Nicholas Satterlee Associates, Washington, DC, 1973.) - 4 Logan Circle (House), Washington, District of Columbia, DC

  17. Confirmed 2,4-dichlorophenoxyacetic acid toxicosis in a dog.

    PubMed

    Chen, Annie V; Bagley, Rodney S; Talcott, Patricia A

    2010-01-01

    A 2-year-old, intact male Weimaraner was evaluated for episodic extensor rigidity and a stiff gait of 24 hours' duration. Percussion of the proximal appendicular muscles with a reflex hammer resulted in formation of dimples consistent with myotonia. Electromyography identified myotonic potentials. Residues of 2,4-dichlorophenoxyacetic acid (2,4-D) were detected in both serum and urine. The dog was treated with intravenous fluid therapy for 36 hours, and clinical signs improved dramatically. Toxicosis with 2,4-D should be considered a differential for acquired myotonia in dogs with or without systemic signs. Exposed dogs with only clinical signs of myotonia can have good clinical outcomes. A confirmed clinical case of 2,4-D toxicosis in the dog has not previously been reported.

  18. Preparation of 4-amino-2,4-dioxobutanoic acid

    DOEpatents

    Unkefer, Pat J.; Martinez, Rodolfo A.; Glass, David R.

    2016-03-22

    A process for synthesizing 4-amino-2,4-dioxobutanoate involves reacting a dialkyl oxalate with an alkoxide in ethanol to form a reaction mixture, and afterward adding an alkyl cyano acetate to the reaction mixture and allowing a reaction to proceed under conditions suitable to form a first reaction product of the formula diethyl 2-cyano-3-hydroxy-butenedioate, and then isolating the diethyl 2-cyano-3-hydroxy-butenedioate, and afterward reacting the diethyl-2-cyano-3-hydroxy-butenedioate with an aqueous hydroxide under conditions suitable to form 4-amino-2,4-dioxobutanoate. The 4-amino-2,4-dioxobutanoate may be acidified into 4-amino-2,4-dioxobutanoic acid.

  19. Uptake of 2, 4-Dichlorophenoxyacetic acid by Pseudomonas fluorescens

    USGS Publications Warehouse

    Wedemeyer, G.A.

    1966-01-01

    WEDEMEYER, GARY (Fish-Pesticide Research Laboratory, Denver, Colo.). Uptake of 2,4-dichlorophenoxyacetic acid by Pseudomonas fluorescens. Appl. Microbiol. 14:486-491. 1966.-Factors influencing the uptake of the sodium salt of 2,4-dichlorophenoxyacetic acid (2,4-D), under conditions in which no net metabolism occurred, were investigated in an effort to determine both the significance of “nonmetabolic” uptake as a potential agent in reducing pesticide levels and the mechanisms involved. Uptake of 2,4-D was affected by pH, temperature, and the presence of other organic and inorganic compounds. Uptake was more pronounced at pH values less than 6, which implies that there may be some interaction between charged groups on the cell and the ionized carboxyl group of 2,4-D. Active transport, carriermediated diffusion, passive diffusion, and adsorption were considered as possible mechanisms. Though uptake was inhibited by glucose, sodium azide, and fluorodinitrobenzene (but not by uranylion), 2,4-D was not accumulated against a concentration gradient, a necessary consequence of an active transport system, nor was isotope counterflow found to occur. Thus, carrier-mediated diffusion was finally precluded, implying that uptake probably occurs by a two-step process: sorption onto the cell wall followed by passive diffusion into the cytoplasm.

  20. 2-Nitrobenzoate 2-Nitroreductase (NbaA) Switches Its Substrate Specificity from 2-Nitrobenzoic Acid to 2,4-Dinitrobenzoic Acid under Oxidizing Conditions

    PubMed Central

    Song, Woo-Seok; Go, Hayoung; Cha, Chang-Jun; Lee, Cheolju; Yu, Myeong-Hee; Lau, Peter C. K.

    2013-01-01

    2-Nitrobenzoate 2-nitroreductase (NbaA) of Pseudomonas fluorescens strain KU-7 is a unique enzyme, transforming 2-nitrobenzoic acid (2-NBA) and 2,4-dinitrobenzoic acid (2,4-DNBA) to the 2-hydroxylamine compounds. Sequence comparison reveals that NbaA contains a conserved cysteine residue at position 141 and two variable regions at amino acids 65 to 74 and 193 to 216. The truncated mutant Δ65-74 exhibited markedly reduced activity toward 2,4-DNBA, but its 2-NBA reduction activity was unaffected; however, both activities were abolished in the Δ193-216 mutant, suggesting that these regions are necessary for the catalysis and specificity of NbaA. NbaA showed different lag times for the reduction of 2-NBA and 2,4-DNBA with NADPH, and the reduction of 2,4-DNBA, but not 2-NBA, failed in the presence of 1 mM dithiothreitol or under anaerobic conditions, indicating oxidative modification of the enzyme for 2,4-DNBA. The enzyme was irreversibly inhibited by 5,5′-dithio-bis-(2-nitrobenzoic acid) and ZnCl2, which bind to reactive thiol/thiolate groups, and was eventually inactivated during the formation of higher-order oligomers at high pH, high temperature, or in the presence of H2O2. SDS-PAGE and mass spectrometry revealed the formation of intermolecular disulfide bonds by involvement of the two cysteines at positions 141 and 194. Site-directed mutagenesis indicated that the cysteines at positions 39, 103, 141, and 194 played a role in changing the enzyme activity and specificity toward 2-NBA and 2,4-DNBA. This study suggests that oxidative modifications of NbaA are responsible for the differential specificity for the two substrates and further enzyme inactivation through the formation of disulfide bonds under oxidizing conditions. PMID:23123905

  1. Local expression and role of BMP-2/4 in injured spinal cord.

    PubMed

    Cui, Z S; Zhao, P; Jia, C X; Liu, H J; Qi, R; Cui, J W; Cui, J H; Peng, Q; Lin, B; Rao, Y J

    2015-08-07

    We investigated local changes in BMP-2/4 expression in rat spinal cords 1 week following injury to study the damage effects of BMP-2/4 in spinal cord injury (SCI). Sprague Dawley rats (45, 4 months old) were randomized into three groups comprising 15 rats each: a SHAM group, an SCI without noggin group (SCIO), and an SCI with noggin group (SCID). The SCIO and SCID groups were subjected to spinal cord hemisection, and motor activity was assessed using the BBB score. Expression of BMP-2/4 in each injured spinal cord section was examined by hematoxylin and eosin staining, immunohistochemistry, and western blot. There were no significant differences in BBB scores among the three groups (P > 0.05). Following hemisection, the BBB score in the SHAM group was significantly higher than in the other two groups on the 1st day after modeling (P < 0.05), and the BBB scores in the SCIO and SCID groups were not significantly different (P > 0.05). Seven days after modeling, the BBB score in the SHAM group was significantly higher than in the other two groups (P < 0.05), and the BBB score in the SCID group was obviously higher than in the SCIO group (P < 0.05). The expression of BMP-2/4 was highest in the SCIO group and lowest in the SHAM group (P < 0.05). SCI can cause severe impairment of motor activity in rats. Seven days after SCI, the local expression of BMP-2/4 had obviously increased; noggin can effectively inhibit the expression of BMP-2/4 and reduce impairment.

  2. 2,4-D toxicosis.III: An attempt to produce 2,4-D toxicosis in dogs on treated grass plots.

    PubMed

    Arnold, E K; Lovell, R A; Beasley, V R; Parker, A J; Stedelin, J R

    1991-10-01

    Eighteen English pointer dogs were randomly assigned to 3 outdoor grass-plot enclosures (6/enclosure) uniformly sprayed once with either the 2,4-dichlorophenoxyacetic acid (2,4-D) dimethylamine formulation (DMA-4) at the maximum recommended application rate, DMA-4 at 4 times the maximum recommended application rate, or the DMA-4 vehicle alone at 4 times the maximum recommended application rate. A heavy rain shower occurred 24 h after application. The dogs were observed for clinical signs and evaluated using an electroencephalograph, electrocardiograph (lead I), and electromyograph prior to exposure, and either 1 or 7 d after continuous exposure. Clinical examination, hematologic and serum biochemical data were obtained, and serum, urine and kidney 2,4-D were quantified. Half of the dogs from each group were killed after 1 d of continuous exposure, while the other half were killed after 7 d. Gross postmortem and histologic examinations were conducted on each dog. No obvious 2,4-D effects were detected in any of the dogs.

  3. Comprehensive investigations of kinetics of alkaline hydrolysis of TNT (2,4,6-trinitrotoluene), DNT (2,4-dinitrotoluene), and DNAN (2,4-dinitroanisole).

    PubMed

    Sviatenko, Liudmyla; Kinney, Chad; Gorb, Leonid; Hill, Frances C; Bednar, Anthony J; Okovytyy, Sergiy; Leszczynski, Jerzy

    2014-09-01

    Combined experimental and computational techniques were used to analyze multistep chemical reactions in the alkaline hydrolysis of three nitroaromatic compounds: 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), and 2,4-dinitroanisole (DNAN). The study reveals common features and differences in the kinetic behavior of these compounds. The analysis of the predicted pathways includes modeling of the reactions, along with simulation of UV-vis spectra, experimental monitoring of reactions using LC/MS techniques, development of the kinetic model by designing and solving the system of differential equations, and obtaining computationally predicted kinetics for decay and accumulation of reactants and products. Obtained results suggest that DNT and DNAN are more resistant to alkaline hydrolysis than TNT. The direct substitution of a nitro group by a hydroxide represents the most favorable pathway for all considered compounds. The formation of Meisenheimer complexes leads to the kinetic first-step intermediates in the hydrolysis of TNT. Janovsky complexes can also be formed during hydrolysis of TNT and DNT but in small quantities. Methyl group abstraction is one of the suggested pathways of DNAN transformation during alkaline hydrolysis.

  4. The effects of sublethal levels of 2,4-dichlorophenoxyacetic acid herbicide (2,4-D) on feeding behaviors of the crayfish O. rusticus.

    PubMed

    Browne, Amanda M; Moore, Paul A

    2014-08-01

    The widespread use of herbicides across the globe has increased the probability of synthetic chemicals entering freshwater habitats. On entering aquatic habitats, these chemicals target and disrupt both physiological and behavioral functioning in various aquatic organisms. Herbicides, such as 2,4-dichlorophenoxyacetic acid (2,4-D), can have negative impacts on chemoreception because these receptor cells are in direct contact with water-soluble chemicals in the environment. Studies focusing on lethal concentration (LC50) levels may understate the impact of herbicides within aquatic habitats because damage to the chemoreceptors can result in modified behaviors or lack of appropriate responses to environmental or social cues. The purpose of this experiment was to determine whether exposure to sublethal levels of 2,4-D alters the foraging behaviors of crayfish Orconectes rusticus. We hypothesized that crayfish exposed to greater concentrations of 2,4-D would be less successful in locating food or on locating food would consume smaller amounts possibly due to an inability to recognize the food odors in the contaminated waters. Crayfish were exposed to three sublethal levels of 2,4-D for 96 h and placed into a Y-maze system with a fish gelatin food source placed randomly in the right or left arm. Average walking speed, average time spent in the correct arm, and percent consumption were analyzed. Our data show that crayfish were impaired in their ability to forage effectively. These inabilities to locate and consume adequate amounts of food could result in lower body weights and decreased fitness in populations of crayfish exposed to 2,4-D in natural habitats.

  5. Toxic and genotoxic effects of the 2,4-dichlorophenoxyacetic acid (2,4-D)-based herbicide on the Neotropical fish Cnesterodon decemmaculatus.

    PubMed

    Ruiz de Arcaute, C; Soloneski, S; Larramendy, M L

    2016-06-01

    Acute toxicity and genotoxicity of the 54.8% 2,4-D-based commercial herbicide DMA® were assayed on Cnesterodon decemmaculatus (Pisces, Poeciliidae). Whereas lethal effect was used as the end point for mortality, frequency of micronuclei (MNs), other nuclear abnormalities and primary DNA damage evaluated by the single cell gel electrophoresis (SCGE) assay were employed as end points for genotoxicity. Mortality studies demonstrated an LC50 96 h value of 1008 mg/L (range, 929-1070) of 2,4-D. Behavioral changes, e.g., gathering at the bottom of the aquarium, slowness in motion, slow reaction and abnormal swimming were observed. Exposure to 2,4-D within the 252-756 mg/L range increased the frequency of MNs in fish exposed for both 48 and 96 h. Whereas blebbed nuclei were induced in treatments lasting for 48 and 96 h, notched nuclei were only induced in fish exposed for 96 h. Regardless of both concentration and exposure time, 2,4-D did not induce lobed nuclei and binucleated erythrocytes. In addition, we found that exposure to 2,4-D within the 252-756 mg/L range increased the genetic damage index in treatments lasting for either 48 and 96 h. The results represent the first experimental evidence of the lethal and several sublethal effects, including behavioral alterations and two genotoxic properties namely the induction of MNs and primary DNA strand breaks, exerted by 2,4-D on an endemic organism as C. decemmaculatus.

  6. Insight into the mode of action of 2,4-dichlorophenoxyacetic acid (2,4-D) as an herbicide.

    PubMed

    Song, Yaling

    2014-02-01

    2,4-Dichlorophenoxyacetic acid (2,4-D) was the first synthetic herbicide to be commercially developed and has commonly been used as a broadleaf herbicide for over 60 years. It is a selective herbicide that kills dicots without affecting monocots and mimics natural auxin at the molecular level. Physiological responses of dicots sensitive to auxinic herbicides include abnormal growth, senescence, and plant death. The identification of auxin receptors, auxin transport carriers, transcription factors response to auxin, and cross-talk among phytohormones have shed light on the molecular action mode of 2,4-D as a herbicide. Here, the molecular action mode of 2,4-D is highlighted according to the latest findings, emphasizing the physiological process, perception, and signal transduction under herbicide treatment.

  7. 2,4-Dichlorophenoxyacetic acid (2,4-D)- and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)-degrading gene cluster in the soybean root-nodulating bacterium Bradyrhizobium elkanii USDA94.

    PubMed

    Hayashi, Shohei; Sano, Tomoki; Suyama, Kousuke; Itoh, Kazuhito

    2016-01-01

    Herbicides 2,4-dichlorophenoxyacetic acid (2,4-D)- and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)-degrading Bradyrhizobium strains possess tfdAα and/or cadABC as degrading genes. It has been reported that root-nodulating bacteria belonging to Bradyrhizobium elkanii also have tfdAα and cadA like genes but lack the ability to degrade these herbicides and that the cadA genes in 2,4-D-degrading and non-degrading Bradyrhizobium are phylogenetically different. In this study, we identified cadRABCK in the genome of a type strain of soybean root-nodulating B. elkanii USDA94 and demonstrated that the strain could degrade the herbicides when cadABCK was forcibly expressed. cadABCK-cloned Escherichia coli also showed the degrading ability. Because co-spiked phenoxyacetic acid (PAA) could induce the degradation of 2,4-D in B. elkanii USDA94, the lack of degrading ability in this strain was supposed to be due to the low inducing potential of the herbicides for the degrading gene cluster. On the other hand, tfdAα from B. elkanii USDA94 showed little potential to degrade the herbicides, but it did for 4-chlorophenoxyacetic acid and PAA. The 2,4-D-degrading ability of the cad cluster and the inducing ability of PAA were confirmed by preparing cadA deletion mutant. This is the first study to demonstrate that the cad cluster in the typical root-nodulating bacterium indeed have the potential to degrade the herbicides, suggesting that degrading genes for anthropogenic compounds could be found in ordinary non-degrading bacteria. PMID:27296963

  8. 2,4-Dichlorophenoxyacetic acid (2,4-D)- and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)-degrading gene cluster in the soybean root-nodulating bacterium Bradyrhizobium elkanii USDA94.

    PubMed

    Hayashi, Shohei; Sano, Tomoki; Suyama, Kousuke; Itoh, Kazuhito

    2016-01-01

    Herbicides 2,4-dichlorophenoxyacetic acid (2,4-D)- and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)-degrading Bradyrhizobium strains possess tfdAα and/or cadABC as degrading genes. It has been reported that root-nodulating bacteria belonging to Bradyrhizobium elkanii also have tfdAα and cadA like genes but lack the ability to degrade these herbicides and that the cadA genes in 2,4-D-degrading and non-degrading Bradyrhizobium are phylogenetically different. In this study, we identified cadRABCK in the genome of a type strain of soybean root-nodulating B. elkanii USDA94 and demonstrated that the strain could degrade the herbicides when cadABCK was forcibly expressed. cadABCK-cloned Escherichia coli also showed the degrading ability. Because co-spiked phenoxyacetic acid (PAA) could induce the degradation of 2,4-D in B. elkanii USDA94, the lack of degrading ability in this strain was supposed to be due to the low inducing potential of the herbicides for the degrading gene cluster. On the other hand, tfdAα from B. elkanii USDA94 showed little potential to degrade the herbicides, but it did for 4-chlorophenoxyacetic acid and PAA. The 2,4-D-degrading ability of the cad cluster and the inducing ability of PAA were confirmed by preparing cadA deletion mutant. This is the first study to demonstrate that the cad cluster in the typical root-nodulating bacterium indeed have the potential to degrade the herbicides, suggesting that degrading genes for anthropogenic compounds could be found in ordinary non-degrading bacteria.

  9. Uptake of 2,4-Dichlorophenoxyacetic Acid by Pseudomonas fluorescens

    USGS Publications Warehouse

    Wedemeyer, Gary

    1966-01-01

    Factors influencing the uptake of the sodium salt of 2,4-dichlorophenoxyacetic acid (2,4-D), under conditions in which no net metabolism occurred, were investigated in an effort to determine both the significance of “non-metabolic” uptake as a potential agent in reducing pesticide levels and the mechanisms involved. Uptake of 2,4-D was affected by pH, temperature, and the presence of other organic and inorganic compounds. Uptake was more pronounced at pH values less than 6, which implies that there may be some interaction between charged groups on the cell and the ionized carboxyl group of 2,4-D. Active transport, carrier-mediated diffusion, passive diffusion, and adsorption were considered as possible mechanisms. Though uptake was inhibited by glucose, sodium azide, and fluorodinitrobenzene (but not by uranyl ion), 2,4-D was not accumulated against a concentration gradient, a necessary consequence of an active transport system, nor was isotope counterflow found to occur. Thus, carrier-mediated diffusion was finally precluded, implying that uptake probably occurs by a two-step process: sorption onto the cell wall followed by passive diffusion into the cytoplasm.

  10. 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

  11. 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

  12. Kinetic of carbonaceous substrate in an upflow anaerobic sludge sludge blanket (UASB) reactor treating 2,4 dichlorophenol (2,4 DCP).

    PubMed

    Sponza, Delia Teresa; Uluköy, Ayşen

    2008-01-01

    The performance of an upflow anaerobic sludge blanket (UASB) reactor treating 2,4 dichlorophenol (2,4 DCP) was evaluated at different hydraulic retention times (HRTs) using synthetic wastewater in order to obtain the growth substrate (glucose-COD) and 2,4 DCP removal kinetics. Treatment efficiencies of the UASB reactor were investigated at different hydraulic retention times (2-20 h) corresponding to a food to mass (F/M) ratio of 1.2-1.92 g-COD g(-1) VSS day(-1). A total of 65-83% COD removal efficiencies were obtained at HRTs of 2-20 h. In all, 83% and 99% 2,4 DCP removals were achieved at the same HRTs in the UASB reactor. Conventional Monod, Grau Second-order and Modified Stover-Kincannon models were applied to determine the substrate removal kinetics of the UASB reactor. The experimental data obtained from the kinetic models showed that the Monod kinetic model is more appropriate for correlating the substrate removals compared to the other models for the UASB reactor. The maximum specific substrate utilization rate (k) (mg-COD mg(-1) SS day(-1)), half-velocity concentration (K(s)) (mg COD l(-1)), growth yield coefficient (Y) (mg mg(-1)) and bacterial decay coefficient (b) (day(-1)) were 0.954 mg-COD mg(-1) SS day(-1), 560.29 mg-COD l(-1), 0.78 mg-SS g(-1)-COD, 0.093 day(-1) in the Conventional Monod kinetic model. The second-order kinetic coefficient (k(2)) was calculated as 0.26 day(-1) in the Grau reaction kinetic model. The maximum COD removal rate constant (U(max)) and saturation value (K(B)) were calculated as 7.502 mg CODl(-1)day(-1) and 34.56 mg l(-1)day(-1) in the Modified Stover-Kincannon Model. The (k)(mg-2,4 DCP mg(-1) SS day(-1)), (K(s)) (mg 2,4 DCPl(-1)), (Y) (mg SS mg(-1) 2,4 DCP) and (k(d)) (day(-1)) were 0.0041 mg-2,4 DCP mg(-1) SS day(-1), 2.06 mg-COD l(-1), 0.0017 mg-SS mg(-1) 2,4 DCP and 3.1 x 10(-5) day(-1) in the Conventional Monod kinetic model for 2,4 DCP degradation. The second-order kinetic coefficient (k(2)) was calculated as 0.30 day

  13. Novel synthesized 2, 4-DAPG analogues: antifungal activity, mechanism and toxicology.

    PubMed

    Gong, Liang; Tan, Haibo; Chen, Feng; Li, Taotao; Zhu, Jianyu; Jian, Qijie; Yuan, Debao; Xu, Liangxiong; Hu, Wenzhong; Jiang, Yueming; Duan, Xuewu

    2016-01-01

    2, 4-Diacetylphloroglucinol (2,4-DAPG), a natural phenolic compound, has been investigated in light of its biological activities against plant pathogens. To improve its potential application, fourteen 2,4-DAPG analogous were synthesized through the Friedel-Crafts reaction using acyl chlorides and phloroglucinol. Of the 2,4-DAPG derivatives, MP4 exhibited much higher antifungal activity against Penicillium digitatum and P. italicum, the major pathogenic fungi in citrus fruit, than 2, 4-DAPG in vitro, and significantly inhibited the development of decay in harvested mandarin (Citrus reticulata Blanco cv. Shatang.) fruit in vivo. It was found that MP4 resulted in the wrinkle of the hyphae in both fungi with serious folds and breakage. In addition, the expression of several cytochrome P450 (CYP) genes were also modified in both fungi by MP4, which might be associated with the disorder of cell membrane formation. Furthermore, the toxicology of MP4 by evaluating the cell proliferation effect on human normal lung epithelial (16HBE) and kidney 293 (HEK293) cells, was significantly lower than that of albesilate, a widely used fungicide in harvested citrus fruit. In summary, the synthesized MP4 has shown a great potential as a novel fungicide that might be useful for control of postharvest decay in citrus fruit. PMID:27562341

  14. Novel synthesized 2, 4-DAPG analogues: antifungal activity, mechanism and toxicology

    PubMed Central

    Gong, Liang; Tan, Haibo; Chen, Feng; Li, Taotao; Zhu, Jianyu; Jian, Qijie; Yuan, Debao; Xu, Liangxiong; Hu, Wenzhong; Jiang, Yueming; Duan, Xuewu

    2016-01-01

    2, 4-Diacetylphloroglucinol (2,4-DAPG), a natural phenolic compound, has been investigated in light of its biological activities against plant pathogens. To improve its potential application, fourteen 2,4-DAPG analogous were synthesized through the Friedel-Crafts reaction using acyl chlorides and phloroglucinol. Of the 2,4-DAPG derivatives, MP4 exhibited much higher antifungal activity against Penicillium digitatum and P. italicum, the major pathogenic fungi in citrus fruit, than 2, 4-DAPG in vitro, and significantly inhibited the development of decay in harvested mandarin (Citrus reticulata Blanco cv. Shatang.) fruit in vivo. It was found that MP4 resulted in the wrinkle of the hyphae in both fungi with serious folds and breakage. In addition, the expression of several cytochrome P450 (CYP) genes were also modified in both fungi by MP4, which might be associated with the disorder of cell membrane formation. Furthermore, the toxicology of MP4 by evaluating the cell proliferation effect on human normal lung epithelial (16HBE) and kidney 293 (HEK293) cells, was significantly lower than that of albesilate, a widely used fungicide in harvested citrus fruit. In summary, the synthesized MP4 has shown a great potential as a novel fungicide that might be useful for control of postharvest decay in citrus fruit. PMID:27562341

  15. Degradation characteristics of 2,4-dichlorophenoxyacetic acid in electro-biological system.

    PubMed

    Zhang, Jingli; Cao, Zhanping; Zhang, Hongwei; Zhao, Lianmei; Sun, Xudong; Mei, Feng

    2013-11-15

    The reductive degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in an electro-biological system, a biological system and an electric catalytic system, respectively. Electrochemical characteristics were monitored by cyclic voltammetry and the intermediate products of 2,4-D degradation were determined by high speed liquid chromatography (HPLC). The results showed that all 2,4-D degradations in the three systems conformed to the kinetics characteristics of one-order reaction, and the degradation kinetics constants were 28.74 × 10(-2) h(-1), 19.73 × 10(-2) h(-1) and 3.54 × 10(-2) h(-1), respectively. The kinetics constant in the electro-biological system was higher than the sum in the other two systems by 19%. The electrochemical assistance provided the electrons and accelerated the electron transfer rate in the microbial degradation of 2,4-D. The degradation resulted from the microbial reduction strengthened by the electrochemical assistance. The electron transfer existed between the electrode, cytochrome, NAD and the pollutants. A long-range electron transfer process could be achieved on the multi-phase interfaces between the electrode, bacteria and the pollutants.

  16. Preparation of 4-amino-2,4-dioxobutanoic acid

    SciTech Connect

    Unkefer, Pat J.; Martinez, Rodolfo A.; Glass, David R.

    2015-06-02

    A process for synthesizing 4-amino-2,4-dioxobutanoic acid involves reacting diethyl oxalate with sodium ethoxide in ethanol to form a reaction mixture, and afterward adding ethyl cyanoacetate to the reaction mixture and allowing a reaction to proceed under conditions suitable to form a first reaction product of the formula diethyl-2-cyano-3-hydroxy-butenedioate, and then isolating the diethyl-2-cyano-3-hydroxybutenedioate, and afterward reacting the diethyl-2-cyano-3-hydroxy-butenedioate with aqueous sodium hydroxide under conditions suitable to form 4-amino-2,4-dioxobutanoic acid.

  17. Preparation of 4-amino-2,4-dioxobutanoic acid

    DOEpatents

    Unkefer, Pat J.; Martinez, Rodolfo A.; Glass, David R.

    2016-03-22

    A process for synthesizing 4-amino-2,4-dioxobutanoic acid involves reacting diethyl oxalate with an alkoxide in ethanol to form a reaction mixture, and afterward adding ethyl cyanoacetate to the reaction mixture and allowing a reaction to proceed under conditions suitable to form a first reaction product of the formula diethyl 2-cyano-3-hydroxy-butenedioate, and then isolating the diethyl 2-cyano-3-hydroxy-butenedioate, and afterward reacting the diethyl-2-cyano-3-hydroxy-butenedioate with an aqueous hydroxide under conditions suitable to form 4-amino-2,4-dioxobutanoic acid.

  18. Biomonitoring Equivalents (BE) dossier for 2,4-dichlorophenoxyacetic acid (2,4-D) (CAS No. 94-75-7).

    PubMed

    Aylward, Lesa L; Hays, Sean M

    2008-08-01

    Recent efforts by the US Centers for Disease Control and Prevention and other researchers have resulted in a growing database of measured concentrations of chemical substances in blood or urine samples taken from the general population. However, few tools exist to assist in the interpretation of the measured values in a health risk context. Biomonitoring Equivalents (BEs) are defined as the concentration or range of concentrations of a chemical or its metabolite in a biological medium (blood, urine, or other medium) that is consistent with an existing health-based exposure guideline. This document reviews available pharmacokinetic data and models for 2,4-dichlorophenoxyacetic acid (2,4-D) and applies these data and models to existing health-based exposure guidance values from the US Environmental Protection Agency to estimate corresponding BE values for 2,4-D in plasma and urine. These values can be used as screening tools for evaluation of biomonitoring data for 2,4-D in the context of the existing USEPA risk assessment and for prioritization of the potential need for additional risk assessment efforts for 2,4-D.

  19. High body burdens of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) in California women.

    PubMed Central

    Petreas, Myrto; She, Jianwen; Brown, F Reber; Winkler, Jennifer; Windham, Gayle; Rogers, Evan; Zhao, Guomao; Bhatia, Rajiv; Charles, M Judith

    2003-01-01

    Following our first report on elevated polybrominated diphenyl ether (PBDE) concentrations in California women, we expanded our investigation to include diverse groups of local women. We analyzed additional adipose and serum samples collected in the late 1990s from San Francisco Bay Area women participating in a breast cancer study and in a reproductive study, respectively. Adipose samples (n = 32) were analyzed by low-resolution mass spectrometry in negative-ion chemical ionization mode, whereas serum samples (n = 50) were analyzed by dual-column gas chromatography with electron capture detection. The results confirmed our earlier findings. Concentrations of 2,2,4,4 -tetrabromodiphenyl ether (BDE-47) in contemporary California women ranged between 5 and 510 ng/g lipid, with a median (16.5 ng/g lipid) 3-10 times higher than those reported from Europe. In contrast, PBDEs were not measurable in any of 420 archived serum samples collected in the 1960s from San Francisco Bay Area women participating in a study of child development. BDE-47 concentrations did not increase with age or with concentrations of a polychlorinated biphenyl (PCB-153), suggesting other routes of exposure in addition to diet. Rising body burdens of endocrine-disrupting chemicals such as PBDEs may pose a potential public health threat. PMID:12842770

  20. 2,4,6-TRINITROTOLUENE TRANSFORMATION IN PLANTED, SOIL COLUMNS

    EPA Science Inventory

    2,4,6-Trinitrotoluene (TNT), has been used extensively by the United States military to manufacture explosive devices. Since the conclusion of World War 11, many of these military installations have also been involved in the disposal of surplus and outdated explosives. Both the c...

  1. 2,2\\',4,4\\'-Tetrabromodiphenyl ether (BDE-47)

    Integrated Risk Information System (IRIS)

    2,2 ' , 4,4 ' - Tetrabromodiphenyl ether ( BDE - 47 ) ; CASRN 5436 - 43 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health H

  2. 2,2\\',4,4\\',5-Pentabromodiphenyl ether (BDE-99)

    Integrated Risk Information System (IRIS)

    2,2 ' , 4,4 ' , 5 - Pentabromodiphenyl ether ( BDE - 99 ) ; CASRN 60348 - 60 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Hea

  3. 2,4-/2,6-Toluene diisocyanate mixture (TDI)

    Integrated Risk Information System (IRIS)

    2,4 - / 2,6 - Toluene diisocyanate mixture ( TDI ) ; CASRN 26471 - 62 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Haz

  4. Di(hydroxyphenyl)- 1,2,4-triazole monomers

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Hergenrother, Paul M. (Inventor); Wolf, Peter (Inventor)

    1993-01-01

    The di(hydroxyphenyl)- 1,2,4-triazole monomers were first synthesized by reacting bis (4-hydroxyphenyl) hydrazide with aniline hydrochloride at 250 C in the melt and also by reacting 1,3 or 1,4-bis- (4-hydroxyphenyl)- phenylene- dihydrazide with 2 moles of aniline hydrochloride in the melt. Purification of the di(hydroxyphenyl)- 1,2,4-triazole monomers was accomplished by recrystallization. Poly (1,2,4-triazoles) (PT) were prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenyl)- 1,2,4-triazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The reactions were carried out in polar aprotic solvents such as sulfolane or diphenylsulfone using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. This synthetic route has provided high molecular weight PT of new chemical structure, is economically and synthetically more favorable than other routes, and allows for facile chemical structure variation due to the availability of a large variety of activated aromatic dihalides.

  5. Photocopy of drawing. VAB HB2 & 4 ET HOLDING CELLS, ...

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

    Photocopy of drawing. VAB HB-2 & 4 ET HOLDING CELLS, UPGRADE TO CHECKOUT CELLS. NASA John F. Kennedy Space Center, Florida. File Number 79K33180, Reynolds, Smith & Hill, February 1991. HINGED PANEL EQUIPMENT SCHEDULE. Sheet 28 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  6. Photocopy of drawing. VAB HB2 & 4 ET HOLDING CELLS, ...

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

    Photocopy of drawing. VAB HB-2 & 4 ET HOLDING CELLS, UPGRADE TO CHECKOUT CELLS. NASA John F. Kennedy Space Center, Florida. File Number 79K33180, Reynolds, Smith & Hill, February 1991. GENERAL ARRANGEMENT, PLAN & ELEVATIONS. Sheet 4 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  7. A Discovery-Learning 2,4-Dinitrophenylhydrazone Experiment

    ERIC Educational Resources Information Center

    Vittimberga, Bruno M.; Ruekberg, Ben

    2006-01-01

    Selections of liquid aldehydes and ketones are proposed for students to determine what property is the best predictor of the color (yellow to red) of their 2,4-dinitrophenylhydrazone derivative. Students may use a computer (spreadsheet or word processor) to analyze results. (Contains 1 table and 3 notes.)

  8. Sorption of 2,4,6-trichlorophenol in model humic acid-clay systems.

    PubMed

    Wang, Xiao-ping; Shan, Xiao-quan; Luo, Lei; Zhang, Shu-Zhen; Wen, Bei

    2005-05-01

    Humic acids and clays are important soil components that influence the sorption and desorption of organic contaminants; however, it is unclear how humic acids influence the sorption of organic contaminants onto clays and their subsequent desorption. Sorption and desorption of 2,4,6-trichlorophenol (2,4,6-TCP) by and from humic acid-modified K(+)- and Ca(2+)-montmorillonite and -illite were compared with unmodified clays using batch equilibration methods. Commercial humic acid and the humic acid extracted from forest soil were employed in this experiment. The adsorbed amount of 2,4,6-TCP by commercial humic acid was almost twice as large as that adsorbed by the extracted soil humic acid. More 2,4,6-TCP was sorbed onto K(+)- and Ca(2+)-illite than onto K(+)- and Ca(2+)-montmorillonite. K(+) clays were more effective in adsorbing 2,4,6-TCP than Ca(2+) clays. Sorption of 2,4,6-TCP on humic acid-modified Ca(2+)- and K(+)-montmorillonite and -illite increased as compared with unmodified clays. The sorption nonlinearity of 2,4,6-TCP on humic acid-modified Ca(2+)- and K(+)-illite increased remarkably as compared with the unmodified clays. The sorption nonlinearity of 2,4,6-TCP on humic acid-modified Ca(2+)- and K(+)-montmorillonite increased slightly in contrast to unmodified montmorillonites. By comparing sorption and desorption results, we observed hysteresis for all sorbents including humic acids, clays, and humic acid-modified clays. Sorption nonlinearity and hysteresis were dependent on the structure of humic acids. Higher aromaticity of humic acids resulted in greater sorption nonlinearity and desorption hysteresis. In addition, sorption capacity (K(f)') was positively correlated with the humic acid content of the sorbents. These results show that modification of humic acids on clays can not only increase the adsorption ability of clays but also affect the sorption nonlinearity of 2,4,6-TCP, and the desorption hysteresis was probably due to the structural

  9. Sequential anaerobic degradation of 2,4-dichlorophenol in freshwater sediments

    SciTech Connect

    Zhang, X.; Wiegel, J. )

    1990-04-01

    2,4-Dichlorophenol (2,4-DCP) was anaerobically degraded in freshwater lake sediments. From observed intermediates in incubated sediment samples and from enrichment cultures, the following sequence of transformations was postulated. 2,4-DCP is dechlorinated to 4-chlorophenol (4-CP), 4-CP is dechlorinated to phenol, phenol is carboxylated to benzoate, and benzoate is degraded via acetate to methane and CO2; at least five different organisms are involved sequentially. The rate-limiting step was the transformation of 4-CP to phenol. Sediment-free enrichment cultures were obtained which catalyzed only the dechlorination of 2,4-DCP, the carboxylation of phenol, and the degradation of benzoate, respectively. Whereas the dechlorination of 2,4-DCP was not inhibited by H2, the dechlorination of 4-CP, and the transformation of phenol and benzoate were. Low concentrations of 4-CP inhibited phenol and benzoate degradation. Transformation rates and maximum concentrations allowing degradation were determined in both freshly collected sediments and in adapted samples: at 31{degrees}C, which was the optimal temperature for the dechlorination, the average adaptation time for 2,4-DCP, 4-CP, phenol, and benzoate transformations were 7, 37, 11 and 2 days, respectively. The maximal observed transformation rates for these compounds in acclimated sediments were 300, 78, 2, 130, and 2,080 micromol/liter(-1)/day(-1), respectively. The highest concentrations which still allowed the transformation of the compound in acclimated sediments were 3.1 m/M 2,4-DCP, 3.1 mM 4-CP, 13 mM phenol, and greater than 52 mM benzoate. The corresponding values were lower for sediments which had not been adapted for the transformation steps.

  10. Effect of 2,4-dichlorophenoxyacetic acid (2,4-D) on PCDD/F emissions from open burning of biomass.

    PubMed

    Muñoz, Maria; Gullett, Brian K; Touati, Abderrahmane; Font, Rafael

    2012-09-01

    To understand the effect of leaf-surface pesticides on emissions of PCDD/F during biomass burns, nine combustion experiments simulating the open burning of biomass were conducted. Needles and branches of Pinus taeda (Loblolly pine) were sprayed with the pesticide 2,4-dichlorophenoxyacetic acid (2,4-D) at 1 and 10 times the manufacturer's recommended application concentration. The biomass was then dried overnight, burned in an open burn test facility, and emission samples were collected, analyzed, and compared against emission samples from burning untreated biomass. Blank tests and analysis of PCDD/F in the raw biomass were also performed. Emission results from burning a water-sprayed control show a ~20-fold increase in PCDD/F levels above that of the raw biomass alone, implicating combustive formation versus simple volatilization. Results from burns of pine branches sprayed with pesticide showed a statistically significant increase in the PCDD/F TEQ emissions when burning biomass at ten times the recommended pesticide concentration (from 0.22 to 1.14 ng TEQ/kg carbon burned (C(b)), both ND = 0). Similarly, a 150-fold increase in the total PCDD/F congener mass (tetra- to octa-chlorinated D/F) above that of the control was observed (from 52 to 7800 ng/kg C(b)), confirming combustive formation of PCDD/F from 2,4-D. More replicate testing is needed to evaluate effects at lower pesticide concentrations.

  11. Study on the degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-methyl-4-chloro-phenoxyacetic sodium (MCPA sodium) in natural agriculture-soils of Fuzhou, China using capillary electrophoresis.

    PubMed

    Fu, Fengfu; Xiao, Linxia; Wang, Wei; Xu, Xueqin; Xu, Liangjun; Qi, Guomin; Chen, Guonan

    2009-03-01

    A new method of analyzing trace 2,4-Dichlorophenoxyacetic acid (2,4-D) and 2-methy-4-chloro-lphenoxyacetic sodium (MCPA sodium) in soils by capillary electrophoresis (CE) has been developed in this study. The optimum analytical conditions including chemical component and concentration of buffer solution, pH, separation voltage and sample injection time were studied in detail. Under the optimum conditions, 2,4-D and MCPA sodium in soils can be speedy separated and determined within 20 min with detection limits of 0.15 microg/g (2,4-D) and 0.25 microg/g (MCPA sodium) , a RSD (n=6)<5% and a recovery>89%. With the help of analytical method developed in this study, the degradations of 2,4-D and MCPA sodium in natural agriculture-soils of Fuzhou were studied. The experimental results indicated that the degradations of 2,4-D and MCPA sodium follow first-order kinetics with degradation constants of 0.1509 day(-1) (2,4-D) and 0.2722 day(-1) (MCPA sodium) respectively. The degradation half-life were calculated to be 4.6 days (2,4-D) and 2.6 days (MCPA sodium) at 27 degrees C, implied that 2,4-D and MCPA sodium can be speedy degraded in natural agriculture-soils of Fuzhou, China.

  12. Thermal decomposition of 2,4,6-trinitrotoluene in melt and solutions

    SciTech Connect

    Dubikhin, V.V.; Matveev, V.G.; Nazin, G.M.

    1995-08-01

    Thermal decomposition of 2,4,6-trinitrotoluene in the temperature range from 200 to 340{degrees}C in melt and in solutions was studied. The main features of the process (high initial rates, activation energies lower than those in the gaseous phase, a higher acceleration at the catalytic stage, and the effect of nonpolar solvents on initial rates) are explained in terms of a kinetic scheme corresponding to a degenerate branched chain reaction.

  13. Crystal structures and fungicidal activities of anti-2,4-bis(X-phenyl)pentane-2,4-diols

    NASA Astrophysics Data System (ADS)

    Jiao, Yinchun; Cao, Chenzhong; Zhao, Xiaolin

    2012-11-01

    The 1,3-diol moiety is present in a number of natural products and has some biological activity. Four symmetric anti-2,4-bis(X-phenyl)pentane-2,4-diols (a, X = p-F; b, X = p-CF3; c, X = m-OMe; d, X = m-CF3) have been characterized by X-ray diffraction, and the results indicated that the dihedral angles between the every two benzene rings in the systems are 34.38(10)°, 39.46(13)°, 23.42(7)°(A), 30.42(7)°(B) and 44.74(9)°, respectively. All of the structures were stabilized by classical intra- and intermolecular hydrogen bonding and some other weak interactions. It was observed that the hydrogen bonding patterns were formed between each single-molecule in compounds a-d, whereas H-bonding dimers were formed in the crystal lattices of both the anti- and syn-2,4-bisphenylpentane-2,4-diols. The four symmetric diaryl 1,3-diols were evaluated alongside several other 1,3-diols as potential antifungal agents, and their in vitro antifungal activities were measured against several fungal species, including Gibberella zeae, Botrytis cinerea, Alternaria alternata and Sclerotonia sclerotiorum.

  14. AN ENZYME LINKED IMMUNOSORBENT ASSAY (ELISA) METHOD FOR MONITORING 2,4 DICHLOROPHENOXYACETIC ACID (2,4-D) EXPOSURES

    EPA Science Inventory

    Abstract describes a streamlined ELISA method developed to quantitatively measure 2,4-D in human urine samples. Method development steps and comparison with gas chromatography/mass spectrometry are presented. Results indicated that the ELISA method could be used as a high throu...

  15. Adsorption of 2,4-Dichlorophenoxyacetic Acid from an Aqueous Solution on Fly Ash.

    PubMed

    Kuśmierek, Krzysztof; Świątkowski, Andrzej

    2016-03-01

    The adsorption of 2,4-dichlorophenoxyacetic acid (2,4-D) on fly ash was studied. The effects of adsorbent dose, contact time, pH, ionic strength, and temperature on the adsorption were investigated. Adsorption kinetic data were analyzed using pseudo-first and pseudo-second order models, and results showed that adsorption kinetics were better represented by the pseudo-second order model. Adsorption isotherms of 2,4-D on fly ash were analyzed using the Freundlich and Langmuir models. Thermodynamic parameters (ΔG°, ΔH°, and ΔS°) indicated that the adsorption process was spontaneous and endothermic. The negative values of ΔG° and the positive value of ΔH° indicate the spontaneous nature of 2,4-D adsorption on fly ash, and that the adsorption process was endothermic. Results showed that fly ash is an efficient, low-cost adsorbent for removal of 2,4-D from water. PMID:26931534

  16. Time Is Money...and the Enemy of College Completion: Transform American Higher Education to Boost Completion and Reduce Costs. Testimony before the United States House of Representatives Subcommittee on Higher Education and Workforce Training

    ERIC Educational Resources Information Center

    Jones, Stan

    2012-01-01

    This paper presents Stan Jones' testimony before the United States House of Representatives Subcommittee on Higher Education and Workforce Training. In his testimony, he talks about a new American majority of students that is emerging on campuses, especially at community colleges. These students must delicately balance long hours at jobs they must…

  17. New efficient artemisinin derived agents against human leukemia cells, human cytomegalovirus and Plasmodium falciparum: 2nd generation 1,2,4-trioxane-ferrocene hybrids.

    PubMed

    Reiter, Christoph; Fröhlich, Tony; Zeino, Maen; Marschall, Manfred; Bahsi, Hanife; Leidenberger, Maria; Friedrich, Oliver; Kappes, Barbara; Hampel, Frank; Efferth, Thomas; Tsogoeva, Svetlana B

    2015-06-01

    In our ongoing search for highly active hybrid molecules exceeding their parent compounds in anticancer, antimalaria as well as antiviral activity and being an alternative to the standard drugs, we present the synthesis and biological investigations of 2nd generation 1,2,4-trioxane-ferrocene hybrids. In vitro tests against the CCRF-CEM leukemia cell line revealed di-1,2,4-trioxane-ferrocene hybrid 7 as the most active compound (IC50 of 0.01 μM). Regarding the activity against the multidrug resistant subline CEM/ADR5000, 1,2,4-trioxane-ferrocene hybrid 5 showed a remarkable activity (IC50 of 0.53 μM). Contrary to the antimalaria activity of hybrids 4-8 against Plasmodium falciparum 3D7 strain with slightly higher IC50 values (between 7.2 and 30.2 nM) than that of their parent compound DHA, hybrids 5-7 possessed very promising activity (IC50 values lower than 0.5 μM) against human cytomegalovirus (HCMV). The application of 1,2,4-trioxane-ferrocene hybrids against HCMV is unprecedented and demonstrated here for the first time.

  18. Mechanism of Enhanced Electrochemical Oxidation of 2,4-dichlorophenoxyacetic Acid with in situ Microwave Activated Boron-doped Diamond and Platinum Anodes

    NASA Astrophysics Data System (ADS)

    Gao, Junxia; Zhao, Guohua; Liu, Meichuan; Li, Dongming

    2009-09-01

    Remarkable enhancement in degradation effect is achieved at in situ activated boron-doped diamond (BDD) and Pt anodes with different extent through electrochemical oxidation (EC) of 2,4-dichlorophenoxyacetic acid (2,4-D) with microwave (MW) radiation in a flow system. Results show that when EC is activated with MW radiation, the complete mineralization time of 2,4-D at the BDD is reduced quickly from 10 to 4 h while Chemical oxygen demand (COD) removal at Pt is increased from 37.7 to 58.3% at 10 h; the initial current efficiency is both improved about 1.5 times while the pseudo-first-order rate constant is increased by 153 and 119% at the BDD and Pt, respectively. To gain insight into the higher efficiency in microwave activated EC, the mechanism has therefore been systematically evaluated from the essence of electrochemical reaction and the accumulated hydroxyl radical concentration. 2,4-Dichlorophenol, catechol, benquinone, and maleic and oxalic acids are the main intermediates on the Pt anode measured by high performance liquid chromatography (HPLC), while the intermediates on the BDD electrode include 2,4-dichlorophenol, hydroquinone, and maleic and oxalic acids. The reaction pathway with microwave radiation is the same as that in a conventional electrochemical oxidation on both electrodes. While less and lower aromatic intermediates produce at the BDD with MW, which suggests the higher ring-open ratio and the faster oxidation of carboxylic acids. With microwave radiation, the ring-open ratio at the BDD is increased to 98.8% from 85.6%; the value at Pt is increased to 67.3% from 35.9%. So microwave radiation can activate the electrochemical oxidation, which leads to the higher efficiency. This promotion is mainly due to the higher accumulated hydroxyl radical concentration and the effects by microwave radiation. All the results prove that the BDD electrode presents much better mineralization performance with MW. To the best of our knowledge, it is the first

  19. Photocopy of drawing. VAB HB2 & 4 ET HOLDING CELLS, ...

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

    Photocopy of drawing. VAB HB-2 & 4 ET HOLDING CELLS, UPGRADE TO CHECKOUT CELLS. NASA John F. Kennedy Space Center, Florida. File Number 79K33180, Reynolds, Smith & Hill, February 1991. H.B.-2, PLANS AT LEVELS 7,8,&9. Sheet 8 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  20. Photocopy of drawing. VAB HB2 & 4 ET HOLDING CELLS, ...

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

    Photocopy of drawing. VAB HB-2 & 4 ET HOLDING CELLS, UPGRADE TO CHECKOUT CELLS. NASA John F. Kennedy Space Center, Florida. File Number 79K33180, Reynolds, Smith & Hill, February 1991. H.B.-2, PLANS AT LEVELS 4,5,&6. Sheet 7 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  1. Photocopy of drawing. VAB HB2 & 4 ET HOLDING CELLS, ...

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

    Photocopy of drawing. VAB HB-2 & 4 ET HOLDING CELLS, UPGRADE TO CHECKOUT CELLS. NASA John F. Kennedy Space Center, Florida. File Number 79K33180, Reynolds, Smith & Hill, February 1991. H.B.-2, PLANS AT LEVELS 1,2,&3. Sheet 6 - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  2. Fragrance material review on 2,4-dimethylbenzyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2,4-dimethylbenzyl acetate when used as a fragrance ingredient is presented. 2,4-Dimethylbenzyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, iso-butyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2,4-dimethylbenzyl acetate were evaluated, then summarized, and includes: physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, and skin sensitization data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances.

  3. Fragrance material review on 2-(4-methylphenoxy)ethanol.

    PubMed

    Scognamiglio, J; Jones, L; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2-(4-methylphenoxy)ethanol when used as a fragrance ingredient is presented. 2-(4-methylphenoxy)ethanol is a member of the fragrance structural group Aryl Alkyl Alcohols and is a primary alcohol. The AAAs are a structurally diverse class of fragrance ingredients that includes primary, secondary, and tertiary alkyl alcohols covalently bonded to an aryl (Ar) group, which may be either a substituted or unsubstituted benzene ring. The common structural element for the AAA fragrance ingredients is an alcohol group -C-(R1)(R2)OH and generically the AAA fragrances can be represented as an Ar-C-(R1)(R2)OH or Ar-Alkyl-C-(R1)(R2)OH group. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2-(4-methylphenoxy)ethanol were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, and skin sensitization data. A safety assessment of the entire Aryl Alkyl Alcohols will be published simultaneously with this document; please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all Aryl Alkyl Alcohols in fragrances.

  4. Anaerobic transformation of 2,4,6-trinitrotoluene (TNT).

    PubMed

    Preuss, A; Fimpel, J; Diekert, G

    1993-01-01

    A sulfate-reducing bacterium using trinitrotoluene (TNT) as the sole nitrogen source was isolated with pyruvate and sulfate as the energy sources. The organism was able to reduce TNT to triaminotoluene (TAT) in growing cultures and cell suspensions and to further transform TAT to still unknown products. Pyruvate, H2, or carbon monoxide served as the electron donors for the reduction of TNT. The limiting step in TNT conversion to TAT was the reduction of 2,4-diamino-6-nitrotoluene (2,4-DANT) to triaminotoluene. The reduction proceeded via 2,4-diamino-6-hydroxylaminotoluene (DAHAT) as an intermediate. The intermediary formation of DAHAT was only observed in the presence of carbon monoxide or hydroxylamine, respectively. The reduction of DAHAT to triaminotoluene was inhibited by both CO and NH2OH. The inhibitors as well as DANT and DAHAT significantly inhibited sulfide formation from sulfite. The data were taken as evidence for the involvement of dissimilatory sulfite reductase in the reduction of DANT and/or DAHAT to triaminotoluene. Hydrogenase purified from Clostridium pasteurianum and carbon monoxide dehydrogenase partially purified from Clostridium thermoaceticum also catalyzed the reduction of DANT in the presence of methyl viologen or ferredoxin, however, as the main reduction product DAHAT rather than triaminotoluene was formed. The findings could explain the function of CO as an electron donor for the DANT reduction (to DAHAT) and the concomitant inhibitory effect of CO on triaminotoluene formation (from DAHAT) by the inhibition of sulfite reductase.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Effect of herbicide concentration and organic and inorganic nutrient amendment on the mineralization of mecoprop, 2,4-D and 2,4,5-T in soil and aquifer samples.

    PubMed

    de Lipthay, Julia R; Sørensen, Sebastian R; Aamand, Jens

    2007-07-01

    The impact of the herbicide concentration (0.10-10,000 microg kg(-1)) and addition of organic and inorganic nutrients on mecoprop, 2,4-D and 2,4,5-T mineralization in aquifer and soil samples was studied in laboratory experiments. Generally, 2,4-D was most rapidly mineralized followed by mecoprop and 2,4,5-T. A shift from non-growth to growth-linked mineralization kinetics was observed in aquifer sediment with 2,4-D concentrations >0.10 microg kg(-1) and mecoprop concentrations >10.0 microg kg(-1). The shift was apparent at higher herbicide concentrations in soil coinciding with a lower bioavailable fraction and a higher herbicide sorption to soil. Herbicide addition did not affect the bacterial density, although 2,4-D and mecoprop applied at 10,000 microg kg(-1) stimulated growth of specific degraders. Generally, nutrient amendments did not stimulate mineralization at the lowest herbicide concentrations. In contrast, the mineralization rate of higher herbicide concentrations was significantly stimulated by the amendment of inorganic nutrients.

  6. Factors Influencing Dislodgeable 2, 4-D Plant Residues from Hybrid Bermudagrass (Cynodon dactylon L. x C. transvaalensis) Athletic Fields.

    PubMed

    Jeffries, Matthew D; Gannon, Travis W; Brosnan, James T; Ahmed, Khalied A; Breeden, Gregory K

    2016-01-01

    Research to date has confirmed 2,4-D residues may dislodge from turfgrass; however, experiments have not been conducted on hybrid bermudagrass (Cynodon dactylon L. x C. transvaalensis), the most common athletic field turfgrass in subtropical climates. More specifically, previous research has not investigated the effect of post-application irrigation on dislodgeable 2,4-D residues from hybrid bermudagrass and across turfgrass species, research has been nondescript regarding sample time within a d (TWD) or conducted in the afternoon when the turfgrass canopy is dry, possibly underestimating potential for dislodgement. The effect of irrigation and TWD on 2,4-D dislodgeability was investigated. Dislodgeable 2,4-D amine was reduced > 300% following irrigation. From 2 to 7 d after treatment (DAT), ≤ 0.5% of applied 2,4-D was dislodged from irrigated turfgrass, while ≤ 2.3% of applied 2,4-D was dislodged when not irrigated. 2,4-D dislodgeability decreased as TWD increased. Dislodgeable 2,4-D residues declined to < 0.1% of the applied at 1 DAT- 13:00, and increased to 1 to 3% of the applied 2 DAT- 5:00, suggesting 2,4-D re-suspended on treated turfgrass vegetation overnight. In conclusion, irrigating treated turfgrass reduced dislodgeable 2,4-D. 2,4-D dislodgeability increased as TWD decreased, which was attributed to non-precipitation climatic conditions favoring turfgrass canopy wetness. This research will improve turfgrass management practices and research designed to minimize human 2,4-D exposure. PMID:26863005

  7. Factors Influencing Dislodgeable 2, 4-D Plant Residues from Hybrid Bermudagrass (Cynodon dactylon L. x C. transvaalensis) Athletic Fields

    PubMed Central

    Ahmed, Khalied A.; Breeden, Gregory K.

    2016-01-01

    Research to date has confirmed 2,4-D residues may dislodge from turfgrass; however, experiments have not been conducted on hybrid bermudagrass (Cynodon dactylon L. x C. transvaalensis), the most common athletic field turfgrass in subtropical climates. More specifically, previous research has not investigated the effect of post-application irrigation on dislodgeable 2,4-D residues from hybrid bermudagrass and across turfgrass species, research has been nondescript regarding sample time within a d (TWD) or conducted in the afternoon when the turfgrass canopy is dry, possibly underestimating potential for dislodgement. The effect of irrigation and TWD on 2,4-D dislodgeability was investigated. Dislodgeable 2,4-D amine was reduced > 300% following irrigation. From 2 to 7 d after treatment (DAT), ≤ 0.5% of applied 2,4-D was dislodged from irrigated turfgrass, while ≤ 2.3% of applied 2,4-D was dislodged when not irrigated. 2,4-D dislodgeability decreased as TWD increased. Dislodgeable 2,4-D residues declined to < 0.1% of the applied at 1 DAT– 13:00, and increased to 1 to 3% of the applied 2 DAT– 5:00, suggesting 2,4-D re-suspended on treated turfgrass vegetation overnight. In conclusion, irrigating treated turfgrass reduced dislodgeable 2,4-D. 2,4-D dislodgeability increased as TWD decreased, which was attributed to non-precipitation climatic conditions favoring turfgrass canopy wetness. This research will improve turfgrass management practices and research designed to minimize human 2,4-D exposure. PMID:26863005

  8. Study of 2,4-dichlorophenoxyacetic acid (2,4-D) removal by Cu-Fe-layered double hydroxide from aqueous solution

    NASA Astrophysics Data System (ADS)

    Nejati, Kamellia; Davary, Soheila; Saati, Marziye

    2013-09-01

    The hydrotalcite-like compound of Cu-Fe-layered double hydroxide was studied as a potential adsorbent of herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The nanoparticles of Cu-Fe layered double hydroxide were prepared by Cu/Fe molar ratio of 2:1 using a coprecipitation method at pH 8.5 and characterized by the X-ray powder diffraction (XRD), the Fourier transform infrared spectroscopy (FT-IR), the thermal gravimetric analysis (TGA) and the elemental analysis. The size and morphology of nanoparticles were examined by the transmission electron microscopy (TEM). The adsorption experiments on LDH, on the other hand, were conducted in three different procedures, namely, time-dependent, pH-dependent and temperature-dependent. Characterization of the adsorption products by the XRD method indicates that the intercalation of 2,4-D between the LDH layers has not occurred and the surface adsorption had taken place. The adsorption kinetic was tested for pseudo-first-order, pseudo-second-order, Elovich and Intra-particle diffusion kinetic models and the rate constants were calculated. The equilibrium adsorption data were described by Langmuir and Freundlich equations. It was observed that, the Langmuir isotherm slightly better fitted to the experimental data rather than that of Freundlich. In the adsorption experiments, the Gibbs free energy values, ΔG°, the enthalpy, ΔH°, and the entropy, ΔS° were also determined.

  9. The detection limit of imaging Raman spectroscopy for 2,4,6-TNT, 2,4-DNT, and RDX

    NASA Astrophysics Data System (ADS)

    Ceco, Ema; Nordberg, Markus; Ehlerding, Anneli; Östmark, Henric

    2012-10-01

    At the Swedish Defence Research Agency, FOI, Raman spectroscopy is used to detect explosives at stand-off distances. A technique based on imaging Raman spectroscopy has been shown to have the potential to detect trace amounts of explosives at stand-off distances. In this publication we provide limits of detection with the current imaging Raman setup for four different substances, cyclotrimethylenetrinitramine (RDX), 2,4-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT), and sulfur. The limits of detection for DNT and TNT were found to be about 0,5 μg while the lowest limit of detection was achieved for sulfur at 200 ng. The detection limit for RDX is 25,9 μg.

  10. Time?

    NASA Astrophysics Data System (ADS)

    Amoroso, Richard L.

    2013-09-01

    The concept of time in the `clockwork' Newtonian world was irrelevant; and has generally been ignored until recently by several generations of physicists since the implementation of quantum mechanics. We will set aside the utility of time as a property relating to physical calculations of events relating to a metrics line element or as an aspect of the transformation of a particles motion/interaction in a coordinate system or in relation to thermodynamics etc., i.e. we will discard all the usual uses of time as a concept used to circularly define physical parameters in terms of other physical parameters; concentrating instead on time as an aspect of the fundamental cosmic topology of our virtual reality especially as it inseparably relates to the nature and role of the observer in natural science.

  11. Photo-Fenton oxidation of phenol and organochlorides (2,4-DCP and 2,4-D) in aqueous alkaline medium with high chloride concentration.

    PubMed

    Luna, Airton J; Chiavone-Filho, Osvaldo; Machulek, Amilcar; de Moraes, José Ermírio F; Nascimento, Cláudio A O

    2012-11-30

    A highly concentrated aqueous saline-containing solution of phenol, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenol (2,4-DCP) was treated by the photo-Fenton process in a system composed of an annular reactor with a quartz immersion well and a medium-pressure mercury lamp (450 W). The study was conducted under special conditions to minimize the costs of acidification and neutralization, which are usual steps in this type of process. Photochemical reactions were carried out to investigate the influence of some process variables such as the initial concentration of Fe(2+) ([Fe(2+)](0)) from 1.0 up to 2.5 mM, the rate in mmol of H(2)O(2) fed into the system (FH(2)O(2);in) from 3.67 up to 7.33 mmol of H(2)O(2)/min during 120 min of reaction time, and the initial pH (pH(0)) from 3.0 up to 9.0 in the presence and absence of NaCl (60.0 g/L). Although the optimum pH for the photo-Fenton process is about 3.0, this particular system performed well in experimental conditions starting at alkaline and neutral pH. The results obtained here are promising for industrial applications, particularly in view of the high concentration of chloride, a known hydroxyl radical scavenger and the main oxidant present in photo-Fenton processes.

  12. Anaerobic biodegradation of 2,4-dichlorophenol in freshwater lake sediments at different temperatures

    SciTech Connect

    Kohring, G.W.; Rogers, J.E.; Wiegel, J.

    1989-02-01

    Anaerobic degradation of 2,4-dichlorophenol (2,4-DCP) between 5 and 72 degrees C was investigated. Anaerobic sediment slurries prepared from local freshwater pond sediments were partitioned into anaerobic tubes or serum vials, which then were incubated separately at the various temperatures. Reductive 2,4-DCP dechlorination occurred only in the temperature range between 5 and 50/degree/C, although methane was formed up to 60 degrees C. In sediment samples from two sites and at all tested temperatures from 5 to 50 degrees C, 2,4-DCP was transformed to 4-chlorophenol (4-CP). The 4-CP intermediate was subsequently degraded after an extended lag period in the temperature range from 15 to 40/degree/C. Adaptation periods for 2,4-DCP transformation decreased between 5 and 25/degree/C, were essentially constant between 25 and 35/degree/C, and increased in the tubes incubated at temperatures between 35 and 40/degree/C. The degradation rates increased exponentially between 15 and 30/degree/C, had a second peak at 35/degree/C, and decreased to about 5% of the peak activity by 40/degree/C. In tubes from one sediment sample, incubated at temperatures above 40/degree/C, an increase in the degradation rate was observed following the minimum at 40/degree/C. This suggests that at least two different organisms were involved in the transformation of 2,4-DCP to 4-CP. Storage of the original sediment slurries for 2 months at 12/degree/C resulted in increased adaptation times, but did not affect the degradation rates.

  13. Higher Education or Higher Skilling?

    ERIC Educational Resources Information Center

    Muller, Steven

    1974-01-01

    Higher education may return to education for a minority, an unlikely course; concentrate on higher skilling, the road we are on today; or restore general education, the most attractive possibility, which can be implemented by restoring basic education in literacy, history, human biology, and language. (JH)

  14. DEGRADATION OF THE CHLORINATED PHENOXYACETATE HERBICIDES 2,4-DICHLOROPHENOXYACETIC ACID AND 2,4,5- TRICHLOROPHENOXYACETIC BY PURE AND MIXED BACTERIAL CULTURES

    EPA Science Inventory

    Combined cell suspensions of the 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)-metabolizing organism Pseudomonas cepacia AC1100, and the 2,4-dichlorophenoxyacetic acid (2,4-D)-metabolizing organism Alcaligenes eutrophus JMP134 were shown to effectively degrade either of these compo...

  15. Preparation of crosslinked 1,2,4-oxadiazole polymer

    NASA Technical Reports Server (NTRS)

    Rosser, R. W.; Shalhoub, I. M.; Kwong, H. (Inventor)

    1981-01-01

    New crosslinked 1,2,4-oxadiazole elastomers were prepared by thermally condensing a monomer having the formula H2N(HON)C-R-Q, wherein Q is a triazine ring-forming group such as nitrile or amidine or a mixture of such group with amidoxime, or a mixture of said monomer with R C(NOH)NH2 sub 2 with R in these formulas standing for a bivalent organic radical. In the monomer charge, the overall proportions of amidoxime groups to triazine ring-forming groups varies depending on the extent of crosslinking desired in the final polymer.

  16. Structure of 2,4-Diaminopyrimidine - Theobromine Alternate Base Pairs

    NASA Technical Reports Server (NTRS)

    Gengeliczki, Zsolt; Callahan, Michael P.; Kabelac, Martin; Rijs, Anouk M.; deVries, Mattanjah S.

    2011-01-01

    We report the structure of clusters of 2,4-diaminopyrimidine with 3,7-dimethylxanthine (theobromine) in the gas phase determined by IR-UV double resonance spectroscopy in both the near-IR and mid-IR regions in combination with ab initio computations. These clusters represent potential alternate nucleobase pairs, geometrically equivalent to guanine-cytosine. We have found the four lowest energy structures, which include the Watson-Crick base pairing motif. This Watson-Crick structure has not been observed by resonant two-photon ionization (R2PI) in the gas phase for the canonical DNA base pairs.

  17. Electrochemical oxidation of 2,4,5-trichlorophenoxyacetic acid by metal-oxide-coated Ti electrodes.

    PubMed

    Maharana, Dusmant; Xu, Zesheng; Niu, Junfeng; Rao, Neti Nageswara

    2015-10-01

    Electrochemical oxidation of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) over metal-oxide-coated Ti anodes, i.e., Ti/SnO2-Sb/Ce-PbO2, Ti/SnO2-Sb and Ti/RuO2, was examined. The degradation efficiency of over 90% was attained at 20 min at different initial concentrations (0.5-20 mg L(-1)) and initial pH values (3.1-11.2). The degradation efficiencies of 2,4,5-T on Ti/SnO2-Sb/Ce-PbO2, Ti/SnO2-Sb and Ti/RuO2 anodes were higher than 99.9%, 97.2% and 91.5% at 30 min, respectively, and the respective total organic carbon removal ratios were 65.7%, 54.6% and 37.2%. The electrochemical degradation of 2,4,5-T in aqueous solution followed pseudo-first-order kinetics. The compounds, i.e., 2,5-dichlorohydroquinone and 2,5-dihydroxy-p-benzoquinone, have been identified as the main aromatic intermediates by liquid chromatography-mass spectrometry. The results showed that the energy efficiencies of 2,4,5-T (20 mg L(-1)) degradation with Ti/SnO2-Sb/Ce-PbO2 anode at the optimal current densities from 2 to 16 mA cm(-2) ranged from 8.21 to 18.73 kWh m(-3). PMID:25981800

  18. Use of hairy roots extracts for 2,4-DCP removal and toxicity evaluation by Lactuca sativa test.

    PubMed

    Angelini, Vanina A; Agostini, Elizabeth; Medina, María I; González, Paola S

    2014-02-01

    2,4-Dichlorophenol (2,4-DCP) is widely distributed in wastewaters discharged from several industries, and it is considered as a priority pollutant due to its high toxicity. In this study, the use of different peroxidase extracts for 2,4-DCP removal from aqueous solutions was investigated. Tobacco hairy roots (HRs), wild-type (WT), and double-transgenic (DT) for tomato basic peroxidases (TPX1 and TPX2) were used to obtain different peroxidase extracts: total peroxidases (TPx), soluble peroxidases (SPx), and peroxidases ionically bound to the cell wall (IBPx). All extracts derived from DT HRs exhibited higher peroxidase activity than those obtained from WT HRs. TPx and IBPx DT extracts showed the highest catalytic efficiency values. The optimal conditions for 2,4-DCP oxidation were pH 6.5, H2O2 0.5 mM, and 200 U mL(-1) of enzyme, for all extracts analyzed. Although both TPx extracts were able to oxidize different 2,4-DCP concentrations, the removal efficiency was higher for TPx DT. Polyethylene glycol addition slightly improved 2,4-DCP removal efficiency, and it showed some protective effect on TPx WT after 2,4-DCP oxidation. In addition, using Lactuca sativa test, a reduction of the toxicity of post removal solutions was observed, for both TPx extracts. The results demonstrate that TPx extracts from both tobacco HRs appear to be promising candidate for future applications in removing 2,4-DCP from wastewaters. This is particularly true considering that these peroxidase sources are associated with low costs and are readily available. However, TPx DT has increased peroxidase activity, catalytic efficiency, and higher removal efficiency than TPx WT, probably due to the expression of TPX1 and TPX2 isoenzymes.

  19. Kinetic Batch Soil Adsorption Studies of 2, 4-dinitroanisole (DNAN)

    NASA Astrophysics Data System (ADS)

    Arthur, J.; Mark, N. W.; Taylor, S.; Brusseau, M. L.; Dontsova, K.

    2014-12-01

    Currently the explosive 2, 4, 6- trinitrotoluene (TNT) is used as a main ingredient in munitions; however the compound has failed to meet sensitivity requirements. The replacement compound being tested is 2, 4-dinitroanisole (DNAN). DNAN is less sensitive to shock, high temperatures, and has good detonation characteristics. However, DNAN is more soluble than TNT, which can influence transport and fate behavior and thus bioavailability and exposure potential. DNAN has been shown to have some human and environmental toxicity. The objective of this study was to investigate the environmental fate of DNAN in soil, with a specific focus on sorption processes. Batch experiments were conducted using 11 soils collected from military installations located across the United States. The soils were characterized for pH, specific surface area, electrical conductivity, cation exchange capacity, and organic carbon content. Adsorption kinetic data determined at room temperature were fitted using the first order kinetic equation. Adsorption isotherms were fitted with linear and Freundlich isotherm equations. The magnitudes of the linear adsorption coefficients ranged from 0.6 to 6 cm3/g. Results indicated that the adsorption of DNAN is strongly dependent on the amount of organic carbon present in the soil.

  20. Two-stage biotransformation of 2,4,6-trinitrotoluene

    SciTech Connect

    VanderLoop, S.L.; Suidan, M.T.; Moteleb, M.A.; Maloney, S.W.

    1995-12-31

    TNT is the explosive most widely used by the military, but current technologies for treating munitions production wastewater are costly and produce a secondary waste, spent GAC. Bioremediation holds promise as a more effective and less costly treatment strategy. An anaerobic fluidized-bed granular activated carbon (GAC) bioreactor in series with an activated sludge reactor was used to treat 2,4,6-trinitrotoluene (TNT). A wastewater solution of 100 mg/L 2,4,6-TNT, as well as carbonate buffer and nutrient solutions, were fed to the anaerobic reactor. Ethanol and ammonia were supplied for microbial growth at 540 mg/L and 20 mg/L, respectively. The mixed anaerobic culture completely transformed the TNT to unknown products. Attempts to detect these products by gas chromatography (GC) and high-performance liquid chromatography (HPLC) were unsuccessful. The effluent from this reactor was treated further in an activated sludge system. The TNT transformation products were partially oxidized in the aerobic stage, resulting in recovery of 91% of the total influent nitrogen as ammonia, nitrate, and biomass. This corresponds to recovery of 82% of influent TNT nitrogen.

  1. Effect of herbicidal application of 2,4-dichlorophenoxyacetic acid in Arabidopsis.

    PubMed

    Raghavan, Chitra; Ong, Eng Kok; Dalling, Michael J; Stevenson, Trevor W

    2005-01-01

    The whole genome expression pattern of Arabidopsis in response to the auxinic herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was evaluated using the Affymetrix ATH1-121501 array. Arabidopsis plants were grown in vitro and were exposed to 1 mM 2,4-D for 1 h, after which time gene transcription levels were measured. In response to the treatment 148 genes showed increased levels of transcription and concurrently 85 genes showed decreased levels of transcript. Genes which showed significant change in transcription levels belonged to the following functional categories: transcription, metabolism, cellular communication and signal transduction, subcellular localisation, transport facilitation, protein fate, protein with binding function or cofactor requirement and regulation of/interaction with cellular environment. Interestingly 25.3% of the genes regulated by the treatment could not be classified into a known functional category. The data obtained from these experiments were used to assess the current model of auxinic herbicide action and indicated that 2,4-D not only modulates the expression of auxin, ethylene and abscisic acid (ABA) pathways but also regulates a wide variety of other cellular functions.

  2. Elucidation of two photon absorption of ethylenediaminium (2,4-dinitrophenolate) crystals

    NASA Astrophysics Data System (ADS)

    Indumathi, C.; Sabari Girisun, T. C.; Anitha, K.; Cecil Raj, S. Alfred

    2016-10-01

    Optical quality single crystals of ethylenediaminium (2,4-dinitrophenolate) [EDA(2,4)DNP] were grown by solvent evaporation method for optical limiting applications against intense ultrashot pulse lasers. Single crystal XRD showed that the material crystallizes in monoclinic system with centric space group P21/C. The crystal packing diagram was elucidated for the first time in literature and it revealed six hydrogen bonds played a very important role in stabilizing the structure. A bifurcated hydrogen bond was also observed between ethylenediamminium and dinitrophenolate ions. The formation of charge transfer complex during the reaction of ethylenediamine and 2,4-dinitrophenol was strongly evident through the vibrational spectroscopic studies. TG-DTA and DSC curves indicate that the material exhibited strong decomposition at 224 °C. Ground state absorption analysis showed that the grown crystals possess absorption maxima in UV region (270 nm, 346 nm) and wide optical transmittance window (480-1200 nm) in the entire visible and NIR region. Measurement of two photon absorption (2PA) and optical limiting response by Z-scan technique under nanosecond pulse excitation was reported. Hence EDA(2,4)DNP with high 2PA coefficient (0.79 ± 0.04 × 10-10 m/W) and low limiting threshold (2.40 ± 0.05 × 1012 W/m2) will be a potential candidate for optical limiting applications like eye and sensor protection against short pulse lasers that are well spread in human interactive sectors.

  3. Higher Education.

    ERIC Educational Resources Information Center

    Hendrickson, Robert M.

    This eighth chapter of "The Yearbook of School Law, 1986" summarizes and analyzes over 330 state and federal court cases litigated in 1985 in which institutions of higher education were involved. Among the topics examined were relationships between postsecondary institutions and various governmental agencies; discrimination in the employment of…

  4. Higher Education.

    ERIC Educational Resources Information Center

    Hendrickson, Robert M.; Gregory, Dennis E.

    Decisions made by federal and state courts during 1983 concerning higher education are reported in this chapter. Issues of employment and the treatment of students underlay the bulk of the litigation. Specific topics addressed in these and other cases included federal authority to enforce regulations against age discrimination and to revoke an…

  5. Higher Education.

    ERIC Educational Resources Information Center

    Hendrickson, Robert M.

    Litigation in 1987 was very brisk with an increase in the number of higher education cases reviewed. Cases discussed in this chapter are organized under four major topics: (1) intergovernmental relations; (2) employees, involving discrimination claims, tenured and nontenured faculty, collective bargaining and denial of employee benefits; (3)…

  6. Higher Education.

    ERIC Educational Resources Information Center

    Hendrickson, Robert M.; Finnegan, Dorothy E.

    The higher education case law in 1988 is extensive. Cases discussed in this chapter are organized under five major topics: (1) intergovernmental relations; (2) employees, involving discrimination claims, tenured and nontenured faculty, collective bargaining, and denial of employee benefits; (3) students, involving admissions, financial aid, First…

  7. Higher Learning.

    ERIC Educational Resources Information Center

    Bok, Derek

    Factors that distinguish the United States higher education system and its performance are considered, with attention to new developments, propsects for change, undergraduate education, and professional schools (especially law, business, and medicine). The way universities change the methods and content of their teaching in response to new…

  8. A 2*4 all optical decoder switch based on photonic crystal ring resonators

    NASA Astrophysics Data System (ADS)

    Alipour-Banaei, Hamed; Mehdizadeh, Farhad; Serajmohammadi, Somaye; Hassangholizadeh-Kashtiban, Mahdi

    2015-03-01

    Based on photonic crystal ring resonators and nonlinear Kerr effect in this paper, we proposed a 2*4 all optical decoder switch. Our proposed structure has two logic input ports and one bias input port. This decoder switch has four output ports. Via these two logic input ports, we control the bias signal to transfer toward which output port. We employed numerical methods such as plane wave expansion and finite difference time domain methods for analyzing the proposed structure.

  9. Cork Taint of Wines: Role of the Filamentous Fungi Isolated from Cork in the Formation of 2,4,6-Trichloroanisole by O Methylation of 2,4,6-Trichlorophenol

    PubMed Central

    Álvarez-Rodríguez, María Luisa; López-Ocaña, Laura; López-Coronado, José Miguel; Rodríguez, Enrique; Martínez, María Jesús; Larriba, Germán; Coque, Juan-José R.

    2002-01-01

    Cork taint is a musty or moldy off-odor in wine mainly caused by 2,4,6-trichloroanisole (2,4,6-TCA). We examined the role of 14 fungal strains isolated from cork samples in the production of 2,4,6-TCA by O methylation of 2,4,6-trichlorophenol (2,4,6-TCP). The fungal strains isolated belong to the genera Penicillium (four isolates); Trichoderma (two isolates); and Acremonium, Chrysonilia, Cladosporium, Fusarium, Mortierella, Mucor, Paecilomyces, and Verticillium (one isolate each). Eleven of these strains could produce 2,4,6-TCA when they were grown directly on cork in the presence of 2,4,6-TCP. The highest levels of bioconversion were carried out by the Trichoderma and Fusarium strains. One strain of Trichoderma longibrachiatum could also efficiently produce 2,4,6-TCA in liquid medium. However, no detectable levels of 2,4,6-TCA production by this strain could be detected on cork when putative precursors other than 2,4,6-TCP, including several anisoles, dichlorophenols, trichlorophenols, or other highly chlorinated compounds, were tested. Time course expression studies with liquid cultures showed that the formation of 2,4,6-TCA was not affected by a high concentration of glucose (2% or 111 mM) or by ammonium salts at concentrations up to 60 mM. In T. longibrachiatum the O methylation of 2,4,6-TCP was catalyzed by a mycelium-associated S-adenosyl-l-methionine (SAM)-dependent methyltransferase that was strongly induced by 2,4,6-TCP. The reaction was inhibited by S-adenosyl-l-homocysteine, an inhibitor of SAM-dependent methylation, suggesting that SAM is the natural methyl donor. These findings increase our understanding of the mechanism underlying the origin of 2,4,6-TCA on cork, which is poorly understood despite its great economic importance for the wine industry, and they could also help us improve our knowledge about the biodegradation and detoxification processes associated with chlorinated phenols. PMID:12450804

  10. Biological monitoring of isocyanates and related amines. IV. 2,4- and 2,6-toluenediamine in hydrolysed plasma and urine after test-chamber exposure of humans to 2,4- and 2,6-toluene diisocyanate.

    PubMed

    Brorson, T; Skarping, G; Sangö, C

    1991-01-01

    Two men were exposed to toluene diisocyanate (TDI) atmospheres at three different air concentrations (ca. 25, 50 and 70 micrograms/m3). The TDI atmospheres were generated by a gas-phase permeation method, and the exposures were performed in an 8-m3 stainless-steel test chamber. The effective exposure period was 4 h. The isomeric composition of the air in the test chamber was 30% 2,4-TDI and 70% 2,6-TDI. The concentration of TDI in air of the test chamber was determined by an HPLC method using the 9-(N-methyl-amino-methyl)-anthracene reagent and by a continuous-monitoring filter-tape instrument. Following the hydrolysis of plasma and urine, the related amines, 2,4-toluenediamine (2,4-TDA) and 2,6-toluenediamine (2,6-TDA), were determined as pentafluoropropionic anhydride (PFPA) derivatives by capillary gas chromatography using selected ion monitoring (SIM) in the electron-impact mode. In plasma, 2,4- and 2,6-TDA showed a rapid-phase elimination half-time of ca. 2-5 h, and that for the slow phase was greater than 6 days. A connection was observed between concentrations of 2,4- and 2,6-TDI in air and the levels of 2,4- and 2,6-TDA in plasma. The cumulated amount of 2,4-TDA excreted in the urine over 24 h was ca. 15%-19% of the estimated inhaled dose of 2,4-TDI, and that of 2,6-TDA was ca. 17%-23% of the inhaled dose of 2,6-TDI. A connection was found between the cumulated (24-h) urinary excretion of 2,4- and 2,6-TDA and the air concentration of 2,4- and 2,6-TDI in the test chamber.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1660449

  11. Powdered activated carbon adsorption of two fishy odorants in water: Trans,trans-2,4-heptadienal and trans,trans-2,4-decadienal.

    PubMed

    Li, Xin; Wang, Jun; Zhang, Xiaojian; Chen, Chao

    2015-06-01

    Powdered activated carbon (PAC) adsorption of two fishy odorants, trans,trans-2,4-heptadienal (HDE) and trans,trans-2,4-decadienal (DDE), was investigated. Both the pseudo first-order and the pseudo second-order kinetic models well described the kinetics curves, and DDE was more readily removed by PAC. In isotherm tests, both Freundlich and Modified Freundlich isotherms fitted the experimental data well. PAC exhibited a higher adsorption capacity for DDE than for HDE, which could be ascribed to the difference in their hydrophobicity. The calculated thermodynamic parameters (ΔG0, ΔH0, and ΔS0) indicated an exothermic and spontaneous adsorption process. PAC dosage, pH, and natural organic matter (NOM) presence were found to influence the adsorption process. With increasing PAC dosage, the pseudo first-order and pseudo second-order rate constants both increased. The value of pH had little influence on HDE or DDE molecules but altered the surface charge of PAC, and the maximum adsorption capacity occurred at pH9. The presence of NOM, especially the fraction with molecular weight less than 1k Dalton, hindered the adsorption. The study showed that preloaded NOM impaired the adsorption capacity of HDE or DDE more severely than simultaneously fed NOM did.

  12. Powdered activated carbon adsorption of two fishy odorants in water: Trans,trans-2,4-heptadienal and trans,trans-2,4-decadienal.

    PubMed

    Li, Xin; Wang, Jun; Zhang, Xiaojian; Chen, Chao

    2015-06-01

    Powdered activated carbon (PAC) adsorption of two fishy odorants, trans,trans-2,4-heptadienal (HDE) and trans,trans-2,4-decadienal (DDE), was investigated. Both the pseudo first-order and the pseudo second-order kinetic models well described the kinetics curves, and DDE was more readily removed by PAC. In isotherm tests, both Freundlich and Modified Freundlich isotherms fitted the experimental data well. PAC exhibited a higher adsorption capacity for DDE than for HDE, which could be ascribed to the difference in their hydrophobicity. The calculated thermodynamic parameters (ΔG0, ΔH0, and ΔS0) indicated an exothermic and spontaneous adsorption process. PAC dosage, pH, and natural organic matter (NOM) presence were found to influence the adsorption process. With increasing PAC dosage, the pseudo first-order and pseudo second-order rate constants both increased. The value of pH had little influence on HDE or DDE molecules but altered the surface charge of PAC, and the maximum adsorption capacity occurred at pH9. The presence of NOM, especially the fraction with molecular weight less than 1k Dalton, hindered the adsorption. The study showed that preloaded NOM impaired the adsorption capacity of HDE or DDE more severely than simultaneously fed NOM did. PMID:26040727

  13. Occurrence of earthy and musty odor compounds (geosmin, 2-methylisoborneol and 2,4,6-trichloroanisole) in biologically treated wastewater.

    PubMed

    Urase, T; Sasaki, Y

    2013-01-01

    The concentrations of earthy and musty odor compounds (2-methylisoborneol (2-MIB), geosmin and 2,4,6-trichloroanisole (TCA)) in treated wastewater were measured. Concentrations of 2,4,6-TCA (4.3-37.7 ng/L) and geosmin (3.7-42.2 ng/L) higher than their odor thresholds were detected for effluents from large-scale treatment plants. The effluent from a small-scale wastewater plant treating toilet and kitchen wastewater contained the target earthy and musty odor compounds below the odor thresholds. The ozonation applied as an advanced wastewater treatment process was considerably more effective for the removal of 2,4,6-TCA than for the removal of 2-MIB and geosmin. The measured concentrations of 2,4,6-TCA in river environments without the influence of large-scale wastewater effluents were less than the odor threshold.

  14. The 1,2,4-oxadiazole elastomers. [heat resistant polymers

    NASA Technical Reports Server (NTRS)

    Rosser, R. W.; Shalhoub, I. M.; Kwong, H. (Inventor)

    1981-01-01

    Crosslinked 1,2,4-oxadiazole elastomers were prepared either by thermally condensing a monomer having the formula HwN(HON)C-R-Q, wherein Q is a triazine ring forming group such as nitrile or amidine, or by a mixture of said monomer with RC(NOH)NH22, with R in these formulas standing for a bivalent organic radical containing fluorine, hydrogen, or trifluoromethyl. In the monomer charge, the overall proportions of amidoxime groups to triazine ring forming groups varies depending on the extent of crosslinking desired in the final polymer. The heat and chemical resistant elastomers disclosed can serve, for instance, as adhesives, caulking compounds, channel sealants, fuel tank liners.

  15. CIRCUIT2.4. 2-Stage Classification Modeling

    SciTech Connect

    Wilde, R.A.; Anderson, J.V.

    1987-12-01

    CIRCUIT2.4 is used to design optimum two-stage classification configurations and operating conditions for energy conservation. It permits simulation of five basic grinding-classification circuits, including one single-stage and four two-stage classification arrangements. Hydrocyclones, spiral classifiers, and sieve band screens can be simulated, and the user may choose the combination of devices for the flowsheet simulation. In addition, the user may select from four classification modeling methods to achieve the goals of a simulation project using the most familiar concepts. Circuit performance is modeled based on classification parameters or equipment operating conditions. A modular approach was taken in designing the program, which allows future addition of other models with relatively minor changes.

  16. Aerobic biotransformation and mineralization of 2,4,6-trinitrotoluene

    SciTech Connect

    Bae, B.H.; Autenrieth, R.L.; Bonner, J.S.

    1995-12-31

    Respirometric mineralization studies of 2,4,6-trinitrotoluene (TNT) were conducted with microorganisms isolated from a site contaminated with munitions waste in Illinois. Nine aerobic bacterial species were isolated under a carbon- and nitrogen-limited condition and tentatively identified as: one Pseudomonas species; one Enterobacter species; and seven Alcaligenes species. Experiments were performed using each of the nine organisms individually and with a consortium of all nine bacterial species. The aerobic microorganisms were cultured in a sterile nutrient solution with glucose and 20 mg/L TNT. Mineralization was determined using uniformly ring-labeled {sup 14}C-TNT in a respirometer that trapped the evolved CO{sub 2}. Biodegradation behavior was characterized based on oxygen consumption, distribution of {sup 14}C activity, and high-performance liquid chromatography (HPLC) analysis of TNT and its transformation products.

  17. Destruction of 2,4,6-trinitrotoluene by Fenton oxidation

    SciTech Connect

    Li, Z.M.; Comfort, S.D.; Shea, P.J.

    1997-03-01

    Past disposal practices at munitions production facilities have generated numerous acres of 2,4,6-trinitrotoluene (TNT)-contaminated soil. We determined the potential of the Fenton reagent (Fe{sup 2+} and H{sub 2}O{sub 2}) to remediate TNT contamination in water, aqueous extracts of contaminated soil, and soil-water slurries. The effects of H{sub 2}O{sub 2} and Fe{sup 2+} concentrations, solution pH, temperature, and initial TNT concentration on transformation and mineralization rates were evaluated. Treating an aqueous TNT solution (70 mg TNT L{sup -1}) with Fenton reagent (1% H{sub 2}O{sub 2}, 80 mg Fe{sup 2+} L{sup -1}) in the dark resulted in 100% destruction of TNT within 24 h. This coincided with 40% mineralization. Subsequent exposure to light resulted in >90% mineralization. We observed generation of 2,4,6-trinitrobenzoic acid and 1,3,5-trinitrobenzene within 15 min following Fenton oxidation of TNT. This indicates that initial TNT destruction likely occurs by methyl group oxidation and decarboxylation. Subsequent transformations involve nitro moiety removal with ring hydroxylation and cleavage, as evidenced by the stoichiometric recovery of TNT-nitrogen as NO{sub 3}{sup -} and production of oxalic acid as the primary C-containing end product. Upon exposure to light, Fe(II) was regenerated and the oxalate produced from 14C-TNT oxidation disappeared; this coincided with a decrease in solution {sup 14}C activity. Similar observations were made when {sup 14}C-oxalic acid was the starting substrate. Fenton oxidation was also effective in destroying TNT in aqueous extracts of contaminated soil and soil-water slurries. Experimental data provide evidence that the Fenton reagent can effectively remediate TNT-contaminated water and soil. 39 refs., 8 figs., 1 tab.

  18. Predictors of 2,4-dichlorophenoxyacetic acid exposure among herbicide applicators.

    PubMed

    Bhatti, Parveen; Blair, Aaron; Bell, Erin M; Rothman, Nathaniel; Lan, Qing; Barr, Dana B; Needham, Larry L; Portengen, Lutzen; Figgs, Larry W; Vermeulen, Roel

    2010-03-01

    To determine the major factors affecting the urinary levels of 2,4-dichlorophenoxyacetic acid (2,4-D) among county noxious weed applicators in Kansas, we used a regression technique that accounted for multiple days of exposure. We collected 136 12-h urine samples from 31 applicators during the course of two spraying seasons (April to August of 1994 and 1995). Using mixed-effects models, we constructed exposure models that related urinary 2,4-D measurements to weighted self-reported work activities from daily diaries collected over 5 to 7 days before the collection of the urine sample. Our primary weights were based on an earlier pharmacokinetic analysis of turf applicators; however, we examined a series of alternative weighting schemes to assess the impact of the specific weights and the number of days before urine sample collection that were considered. The derived models accounting for multiple days of exposure related to a single urine measurement seemed robust with regard to the exact weights, but less to the number of days considered; albeit the determinants from the primary model could be fitted with marginal losses of fit to the data from the other weighting schemes that considered a different numbers of days. In the primary model, the total time of all activities (spraying, mixing, other activities), spraying method, month of observation, application concentration, and wet gloves were significant determinants of urinary 2,4-D concentration and explained 16% of the between-worker variance and 23% of the within-worker variance of urinary 2,4-D levels. As a large proportion of the variance remained unexplained, further studies should be conducted to try to systematically assess other exposure determinants.

  19. Crystallization of lysozyme with (R)-, (S)- and (RS)-2-methyl-2, 4-pentanediol

    SciTech Connect

    Stauber, Mark; Jakoncic, Jean; Berger, Jacob; Karp, Jerome M.; Axelbaum, Ariel; Sastow, Dahniel; Buldyrev, Sergey V.; Hrnjez, Bruce J.; Asherie, Neer

    2015-03-01

    Crystallization of lysozyme with (R)-2-methyl-2, 4-pentanediol produces more ordered crystals and a higher resolution protein structure than crystallization with (S)-2-methyl-2, 4-pentanediol. The results suggest that chiral interactions with chiral additives are important in protein crystal formation. Chiral control of crystallization has ample precedent in the small-molecule world, but relatively little is known about the role of chirality in protein crystallization. In this study, lysozyme was crystallized in the presence of the chiral additive 2-methyl-2, 4-pentanediol (MPD) separately using the R and S enantiomers as well as with a racemic RS mixture. Crystals grown with (R)-MPD had the most order and produced the highest resolution protein structures. This result is consistent with the observation that in the crystals grown with (R)-MPD and (RS)-MPD the crystal contacts are made by (R)-MPD, demonstrating that there is preferential interaction between lysozyme and this enantiomer. These findings suggest that chiral interactions are important in protein crystallization.

  20. Synthesis and controlled release properties of 2,4-dichlorophenoxy acetate–zinc layered hydroxide nanohybrid

    SciTech Connect

    Bashi, Abbas M.; Hussein, Mohd Zobir; Zainal, Zulkarnain; Tichit, Didier

    2013-07-15

    Direct reaction of ZnO with 2,4-dichlorophenoxyacetic acid (24D) solutions of different concentrations allows obtaining new organic–inorganic nanohybrid materials formed by intercalation of 24D into interlayers of zinc layered hydroxide (ZLH). XRD patterns show a progressive evolution of the structure as 24D concentration increases. The nanohybrid obtained at higher 24D concentration (24D–ZLH(0.4)) reveals a well ordered layered structure with two different basal spacings at 25.2 Å and 24 Å. The FTIR spectrum showing the vibrations bands of the functional groups of 24D and of the ZLH confirms the intercalation. SEM images are in agreement with the structural evolution observed by XRD and reveal the ribbon morphology of the nanohybrids. The release studies of 24D showed a rapid release of 94% for the first 100 min governed by the pseudo-second order kinetic model. - Graphical abstract: The phenomenon indicates that the optical energy gap is enlarged with the increase of molar concentrations in 2,4-dichlorophenoxy acetate anion content into ZnO to create a ZLH–24D nanohybrid. - Highlights: • Nanohybrid was synthesized from 2,4-dichlorophenoxy acetate with-Zinc LHD, using wet chemistry. • Characterized using SEM, TEM, EDX, FTIR, XRD and TGA. • Ribbon-shaped 24D–Zn-layered hydroxide nanoparticles with (003) diffractions of 2.5 nm phase were synthesized.

  1. Determination of the primary molecular target of 1,2,4-triazole-ciprofloxacin hybrids.

    PubMed

    Plech, Tomasz; Kaproń, Barbara; Paneth, Agata; Kosikowska, Urszula; Malm, Anna; Strzelczyk, Aleksandra; Stączek, Paweł; Świątek, Łukasz; Rajtar, Barbara; Polz-Dacewicz, Małgorzata

    2015-01-01

    We have synthesized and examined the antibacterial activity, toxicity and affinity towards bacterial type II topoisomerases of a series of 1,2,4-triazole-ciprofloxacin hybrids. A number of these compounds displayed enhanced activity against Gram-positive and Gram-negative bacteria when compared to ciprofloxacin. The toxic concentrations of the obtained derivatives, evaluated on HEK-293 cells using MTT assay, were much higher than concentrations required to produce antibacterial effect. Finally, the results of enzymatic studies showed that the analyzed compounds demonstrated other preferences as regards primary and secondary molecular targets than ciprofloxacin. PMID:25859782

  2. Providing Higher Education in Post-Modern Times: What Do University Mission Statements Tell Us about What They Believe and Do?

    ERIC Educational Resources Information Center

    Ellis, Jennifer; Miller, Paul

    2014-01-01

    Higher education institutions (HEIs) are critical to the delivery of education for all in any nation state. What they believe and what they do are critical components to creating societal impact. But what they believe and do is not always clear. Using a derivative of SWIFT (Structured Word Identification and Frequency Totals), the authors examined…

  3. Understanding the Changing Faculty Workforce in Higher Education: A Comparison of Full-Time Non-Tenure Track and Tenure Line Experiences

    ERIC Educational Resources Information Center

    Ott, Molly; Cisneros, Jesus

    2015-01-01

    Non-tenure track faculty are a growing majority in American higher education, but research examining their work lives is limited. Moreover, the theoretical frameworks commonly used by scholars have been critiqued for reliance on ideologically charged assumptions. Using a conceptual model developed from Hackman and Oldham's (1980) Job…

  4. Technology, Time and Transition in Higher Education--Two Different Realities of Everyday "Facebook" Use in the First Year of University in the UK

    ERIC Educational Resources Information Center

    Stirling, Eve

    2016-01-01

    Within the range of websites and apps that are part of first-year undergraduates' digital environments, the social network site "Facebook" is perhaps the most popular and prominent. As such, the ubiquitous nature of "Facebook" in the higher education landscape has drawn much attention from scholars. Drawing on data from a…

  5. Assessing the Impact of a Statewide STEM Investment on K-12, Higher Education, and Business/Community STEM Awareness over Time

    ERIC Educational Resources Information Center

    Sondergeld, Toni A.; Johnson, Carla C.; Walten, Janet B.

    2016-01-01

    Despite monetary and educational investments in science, technology, engineering, and mathematics (STEM) being at record high levels, little attention has been devoted to generating a common understanding of STEM. In addition, working with business, K-12 schools, and/or institutions of higher education to establish a grassroots effort to help…

  6. Bimetallic Au-decorated Pd catalyst for the liquid phase hydrodechlorination of 2,4-dichlorophenol

    NASA Astrophysics Data System (ADS)

    Zhou, Juan; Chen, Huan; Chen, Quanyuan; Huang, Zhaolu

    2016-11-01

    Monometallic and bimetallic Pd-Au catalysts supported on multi-walled carbon nanotubes (CNTs) with varied Au cooperation amounts were prepared using the complexing-reduction method in the presence of tetrahydrofuran (THF). The liquid phase catalytic hydrodechlorination (HDC) of 2,4-dichlorophenol (2,4-DCP) was investigated over these bimetallic catalysts. The catalysts were characterized by N2 adsorption-desorption isotherms, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and H2 chemisorption. Characterization results showed that the co-reduction of Pd and Au mainly formed alloy-like structure. The bimetallic catalysts had smaller metal particles and larger numbers of exposed active site than that of monometallic catalysts. In addition, compared with Pd(1.7)/CNTs and Au(0.4)/CNTs, the binding energies of Pd 3d5/2 shifted to higher positions while that of Au 4f7/2 had negative shifts in the Pd-Au bimetallic catalysts, which can be ascribed to the electrons transferred from metal Pd to Au and the cationization of Pd particles was enhanced. Accordingly, the bimetallic Pd-Au particles with different Au contents in the catalysts exhibited varied synergistic effects for the catalytic HDC of 2,4-DCP, with Pd(1.8)Au(0.4)/CNTs having the highest catalytic activity. For the bimetallic catalysts, a disproportional increase of turnover frequency (TOF) was observed with increasing Au content due to the enhanced cationization of Pd particles. Moreover, the dechlorination of 2,4-DCP over the supported monometallic and bimetallic catalysts proceeded via both the stepwise and concerted pathway, and the concerted pathway became predominant with Au decoration amount in the catalyst.

  7. Decreased transpiration in poplar trees exposed to 2,4,6-trinitrotoluene

    SciTech Connect

    Thompson, P.L.; Ramer, L.A.; Guffey, A.P.; Schnoor, J.L.

    1998-01-01

    The improper handling of the toxic compound 2,4,6-trinitrotoluene (TNT) has led to the contamination of soil and groundwater, and the uptake of TNT by a variety of plants has been established. This article discusses the effects of various concentrations of the explosive 2,4,6-trinitrotoluene (TNT) on the transpiration of hybrid poplar trees growing in hydroponic media. Transpiration was measured daily by gravimetric means. The rapid removal of TNT from hydroponic solutions was a result of plant uptake and required a daily dosage of TNT to ensure a relatively constant exposure over time. Transpiration decreased with increasing TNT concentrations {ge}5 mg/L. Decreases in transpiration were accompanied by leaf chlorosis and abscission. A comparison between a laboratory study and a pilot-scale experiment showed good scale-up potential.

  8. Hydrolytic release of bound residues from composted soil contaminated with 2,4,6-trinitrotoluene

    SciTech Connect

    Thorne, P.G.; Leggett, D.C.

    1997-06-01

    The US Army is obligated to restore land previously contaminated with the explosive 2,4,6-trinitrotoluene (TNT). One remediation method that is being tried is composting. In this method, the soil to be treated is mixed with a readily decomposable source of organic carbon, which is usually a mixture of readily available organic material. Samples of composted soil were extracted with solvent, then hydrolyzed with acid or base. The concentrations of extractable, unbound 2,4,6-trinitrotoluene and its mono- and diamino metabolites fell rapidly after the first days of composting. Hydrolysis of the extracted residues released significant quantities of intact metabolites. The objectives of this work were to differentiate between bound and unbound explosives and their transformation products in composted soil, to investigate the time course of metabolite evolution and binding, and to evaluate various hydrolysis methods.

  9. Biodegradation of 2,4-dinitrotoluene by a Pseudomonas sp

    SciTech Connect

    Spanggord, R.J.; Mortelmans, K.E. ); Spain, J.C.; Nishino, S.F. )

    1991-11-01

    Previous studies of the biodegradation of nonpolar nitroaromatic compounds have suggested that microorganism can reduce the nitro groups but cannot cleave the aromatic ring. The authors report here the initial steps in a pathway for complete biodegradation of 2,4-dinitrotoluene (DNT) by a Pseudomonas sp. isolated from a four-member consortium enriched with DNT. The Pseudomonas sp. degraded DNT as the sole source of carbon and energy under aerobic conditions with stoichiometric release of nitrite. During induction of the enzymes required for growth on DNT, 4-methyl-5-nitrocatechol (MNC) accumulated transiently in the culture fluid when cells grown on acetate were transferred to medium containing DNT as the sole carbon and energy source. Conversion of DNT to MNC in the presence of {sup 18}O{sub 2} revealed the simultaneous incorporation of two atoms of molecular oxygen, which demonstrated that the reaction was catalyzed by a dioxygenase. Fully induced cells degraded MNC rapidly with stoichiometric release of nitrite. The results indicate an initial dioxygenase attack at the 4,5 position of DNT with the concomitant release of nitrite. Subsequent reactions lead to complete biodegradation and removal of the second nitro group as nitrite.

  10. 2,4-diacetylphloroglucinol alters plant root development.

    PubMed

    Brazelton, Jessica N; Pfeufer, Emily E; Sweat, Teresa A; Gardener, Brian B McSpadden; Coenen, Catharina

    2008-10-01

    Pseudomonas fluorescens isolates containing the phlD gene can protect crops from root pathogens, at least in part through production of the antibiotic 2,4-diacetylphloroglucinol (DAPG). However, the action mechanisms of DAPG are not fully understood, and effects of this antibiotic on host root systems have not been characterized in detail. DAPG inhibited primary root growth and stimulated lateral root production in tomato seedlings. Roots of the auxin-resistant diageotropica mutant of tomato demonstrated reduced DAPG sensitivity with regards to inhibition of primary root growth and induction of root branching. Additionally, applications of exogenous DAPG, at concentrations previously found in the rhizosphere of plants inoculated with DAPG-producing pseudomonads, inhibited the activation of an auxin-inducible GH3 promoter::luciferase reporter gene construct in transgenic tobacco hypocotyls. In this model system, supernatants of 17 phlD+ P. fluorescens isolates had inhibitory effects on luciferase activity similar to synthetic DAPG. In addition, a phlD() mutant strain, unable to produce DAPG, demonstrated delayed inhibitory effects compared with the parent wild-type strain. These results indicate that DAPG can alter crop root architecture by interacting with an auxin-dependent signaling pathway. PMID:18785830

  11. Water quality criteria for 2,4,6-trinitrotoluene.

    PubMed

    Ryon, M G; Ross, R H

    1990-04-01

    The occurrence of the munitions compound 2,4,6-trinitrotoluene (TNT) in groundwater and surface water surrounding U.S. Army ammunition plants may result in contamination of local drinking water supplies. TNT exerts its primary toxic effect in humans on the hematologic system and liver, but it is also known to cause gastrointestinal effects and cataracts. Health effects data were analyzed for TNT and although no controlled human studies exist concerning the acute or chronic toxic effects of exposure to TNT, sufficient animal toxicity data are available to derive an ambient water quality criterion for the protection of human health. This paper summarizes the available literature on metabolism and toxicity of TNT in humans and animals. Based on noncarcinogenic mammalian toxicity data, and following the methodologies of the U.S. Environmental Protection Agency, an ambient water quality criterion for the protection of human health of 135 micrograms/liter is proposed when consumption of both contaminated water and fish is anticipated. For drinking water alone, the proposed criterion is 140 micrograms/liter.

  12. User's guide for LTGSTD24 program, Version 2. 4

    SciTech Connect

    Hanlon, R.L.; Connell, L.M.

    1993-05-01

    On January 30, 1989, the US Department of Energy (DOE) promulgated an interim rule entitled [open quotes]Energy Conservation Voluntary Performance Standards for New Commercial and Multi-Family High Rise Residential Buildings; Mandatory for New Federal Buildings[close quotes] (10 CFR Part 435, Subpart A). These standards require federal agencies to design all future federal commercial and multifamily high-rise residential buildings in accordance with the standards, or demonstrate that their current requirements already meet or exceed the energy-efficiency requirements of the standards. Although these newly enacted standards do not regulate the design of non-federal buildings, the DOE recommends that all design professionals use the standards as guidelines for designing energy-conserving buildings. To encourage private sector use, the DOE published the standards in the January 30, 1989, Federal Register in the format typical of commercial standards. The Pacific Northwest Laboratory developed several computer programs for the DOE to make it easier for designers to comply with the standards. One of the programs, LTGSTD24 (Version 2.4), is detailed in this user's guide and is provided on the accompanying diskettes. The program will facilitate the designer's use of the standards dealing specifically with building lighting design. Using this program will greatly simplify the designer's task of performing the calculations needed to determine if a design complies with the standards.

  13. Solubility of 2,4,6-trinitrotoluene (TNT) in water

    SciTech Connect

    Ro, K.S.; Venugopal, A.; Adrian, D.D.; Constant, D.; Valsaraj, K.T.; Thibodeaux, L.J.; Qaisi, K.; Roy, D.

    1996-07-01

    Current literature values of 2,4,6-trinitrotoluene (TNT) solubility in water vary widely from 100 to 200 mg/L at room temperature. The authors investigated the effects of temperature and pH on the solubility of both reference TNT and field neat TNT obtained from the Alabama Army Ammunition Plant (AAAP), Childersburg, AL. The TNT solubility determined from this study was significantly lower than that of Taylor and Rinkenbach, which was cited by several reference chemical handbooks and articles. However, the values reported by the Merck Index and the Lange`s Handbook of Chemistry compared well with the authors` values. TNT solubility dropped rapidly as the pH increased. Three unknown HPLC peaks were observed at high pH, indicating a possibility of forming unknown transformation products. Both reference and field neat TNT solubility agreed well. A semiempirical solubility correlation was developed to predict the solubility of TNT at a temperature range from 6 C to 42 C.

  14. Tuning a 2.4-meter telescope... blindfolded

    NASA Astrophysics Data System (ADS)

    Lanclos, Kyle; Peck, Michael; Saylor, Michael; Kibrick, Robert I.; Allen, Steve L.

    2014-07-01

    Just as the 2.4 meter Automated Planet Finder (APF) commenced its final shakedown, three significant events occurred: uncontrolled telescope oscillations while tracking, liquidation of the telescope vendor's primary facility, and the expiration of the vendor warranty. Left with scant documentation, few external resources to draw upon, and limited direct local expertise, University of California Observatories (UCO) embarked on an initiative to stabilize the telescope control system at a minimal internal cost. This paper covers the problems encountered, our solutions, and the compromises made when the budget could not support a complete remedy. Specific topics include: measurement and alignment of linear encoder signals, and custom electronics developed to enable precise alignment of the read heads and adjustment of the interpolation electronics; the use of sensitive accelerometers to isolate and diagnose sources of vibration, and to provide immediate feedback on the stability of the servo tuning; procedures used to adjust the servo control loop, and the observable effects of parameter adjustments; assessment and validation of the performance on-sky.

  15. User's guide for ENVSTD24 program, Version 2. 4

    SciTech Connect

    Hanlon, R.L.; Connell, L.M.

    1993-05-01

    On January 30, 1989, the US Department of Energy (DOE) promulgated an interim rule entitled [open quotes]Energy Conservation Voluntary Performance Standards for New Commercial and Multi-Family High Rise Residential Buildings; Mandatory for New Federal Buildings[close quotes] (10 CFR Part 435, Subpart A). These standards require federal agencies to design all future federal commercial and multifamily high-rise residential buildings in accordance with the standards, or demonstrate that their current requirements already meet or exceed the energy-efficiency requirements of the standards. Although these newly enacted standards do not regulate the design of nonfederal buildings, the DOE recommends that all design professionals use the standards as guidelines for designing energy-conserving buildings. To encourage private sector use, the DOE published the standards in the January 30, 1989, Federal Register in the format typical of commercial standards. The Pacific Northwest Laboratory developed several computer programs for the DOE to make it easier for designers to comply with the standards. One of the programs, ENVSTD24 (Version 2.4), is detailed in this user's guide and is provided on the accompanying diskettes. The program will facilitate the designer's use of the standards dealing specifically with building envelope design. Using this program will greatly simplify the designer's task of performing the calculations needed to determine if a design complies with the standards.

  16. Phytotransformation of 2,4-dinitrotoluene in arabidopsis thaliana: toxicity, fate, and gene expression studies in vitro.

    PubMed

    Yoon, Jong M; Oliver, David J; Shanks, Jacqueline V

    2006-01-01

    Basic knowledge of the plant transformation pathways and toxicity of 2,4-dinitrotoluene (2,4-DNT) will assist in the design and assessment of a phytoremediation strategy. This study presents the toxicity and fate of 2,4-DNT and gene expression in response to 2,4-DNT exposure using the model plant Arabidopsis thaliana, an increasingly popular system for genetic and biochemical studies of phytotransformation of explosives. From the results of biomass and root growth assays for toxicity, 2,4-DNT was toxic to the plants at concentrations as low as 1 mg/L. In the uptake study, 95% of the initial 2,4-DNT was removed by 15-day-old seedlings from liquid media regardless of the initial 2,4-DNT concentrations while 30% accounted for the adsorption to the autoclaved plant materials. The mass balance was over 86% using [U-14C]2,4-DNT, and the mineralization by the plants was less than 1% under sterile conditions during 14 days of exposure. The percentage of the bound radioactivity increased from 49% to 72% of the radioactivity in the plants, suggesting transformed products of 2,4-DNT may be incorporated into plant tissues such as lignin and cellulose. Monoaminonitrotoluene isomers and unknown metabolites with short retention times were detected as transformed products of 2,4-DNT by the plants. Most (68%) of the radioactivity taken up by the plants was in the root tissues in nonsterile hydroponic cultures. Glutathione and expression of related genes (GSH1 and GSH2) in plants exposed to 2,4-DNT were 1.7-fold increased compared to untreated plants. Genes of a glutathione S-transferase and a cytochrome P450, which were induced by 2,4,6-trinitrotoluene exposure in previous studies, were upregulated by 10- and 8-fold, respectively. The application of phytoremediation and the development of transgenic plants for 2,4-DNT may be based on TNT phytotransformation pathway characteristics because of the similar fate and gene expression in plants. PMID:17137297

  17. Development of an immunoassay for determination of 2,4-dichlorophenoxyacetic acid (2,4-D) based upon the recombinant Fab fragment of 2,4-D specific antibody

    NASA Astrophysics Data System (ADS)

    Nguyen, Van C.; Nguyen, Thi D. T.; Dau, Hung A.; Tham, Thu N.; Quyen, Dinh T.; Bachmman, Till; Schmid, Rolf D.

    2001-09-01

    To develop an immunoassay and further an immunosensor for 2,4-D based upon recombinant antibody, the Fab fragments of 2,4-D specific antibody were expressed in E. coli. Western blotting analysis of the periplasmic cell fractions shown that under the non-reducing condition only a single protein band at a molecular mass of 45-kDa, corresponding to the whole Fab fragment was detected. Antigen binding activity for 2,4-D was found only in the extract of cells bearing the 2,4-D plasmid. An immunoassay based on the competitive reaction of 2,4-D and enzyme tracer with 2,4-D Fab fragments immobilized on micro titer plates via rabbit anti-mouse IgC was developed. Using this assay, 2,4-D could be detected at concentration range of 0.5 (mu) g/1 to 10(mu) g/1. The center point of the 2,4-D test was found at a concentration of 5 (mu) g/l. The assay was applied for detection of 2,4-D in spiked orange samples, resulting in recovery rate of 90 percent. The immunoassay could be applied to monitor human exposure to 2,4-D from contamination in fruit samples.

  18. Bonding in d9 complexes derived from EPR: Application to CuCl2-4, CuBr2-4, and CdCl2:Cu2+

    NASA Astrophysics Data System (ADS)

    Aramburu, J. A.; Moreno, M.

    1985-12-01

    In this work are reported the theoretical expressions for the [g], hyperfine, and superhyperfine (shf) tensors of a d9 square-planar complex within a molecular orbital (MO) scheme. These expressions include contributions arising from crystal field and charge transfer excitations calculated up to third and second order perturbations, respectively. This makes the present framework more general than those previously used. Through those expressions we have derived from the experimental EPR and optical data the MO coefficients corresponding to the valence b1g(x2-y2), b2g(xy), and eg(xz,yz) levels and also the core polarization contribution K to the hyperfine tensor for the systems CuCl2-4, CuBr2-4, and CdCl2:Cu2+. The 3d charge obtained for CuCl2-4 is equal to 0.61, 0.83, and 0.85 for the antibonding 3b1g, 2b2g, and 2eg levels, respectively. These figures are much closer to the Xα results by Bencini and Gatteschi [J. Am. Chem. Soc. 105, 5535 (1983)] than to those by Desjardins et al. [J. Am. Chem. Soc. 105, 4590 (1983)]. The σ and π covalency for CuBr2-4 are both higher than for CuCl2-4 in accord to the lower electronegativity for bromine. However, only for the antibonding 3b1g level of CuBr2-4 have we obtained an electronic charge lying mainly on ligands. The covalency of CdCl2:Cu2+ is smaller than that found for CuCl2-4, a fact associated to a higher metal-ligand distance for the former. Evidence of this statement are also given from the analysis of crystal-field spectra and isotropic shf constant. The values of K derived for CuCl2-4 (128.1×10-4 cm-1), CuBr2-4 (103.6×10-4 cm-1), and CdCl2:Cu2+ (123.9×10-4 cm-1) point out the dependence of K on the equatorial covalency but also on the existence of axial ligands. The [g] tensor of CuBr2-4 is dominated by the charge transfer contribution while the crystal field one is negative. Finally an analysis of the importance of each one of the involved contributions to the spin-Hamiltonian parameters is reported for the

  19. Determinants of the abilities to jump higher and shorten the contact time in a running 1-legged vertical jump in basketball.

    PubMed

    Miura, Ken; Yamamoto, Masayoshi; Tamaki, Hiroyuki; Zushi, Koji

    2010-01-01

    This study was conducted to obtain useful information for developing training techniques for the running 1-legged vertical jump in basketball (lay-up shot jump). The ability to perform the lay-up shot jump and various basic jumps was measured by testing 19 male basketball players. The basic jumps consisted of the 1-legged repeated rebound jump, the 2-legged repeated rebound jump, and the countermovement jump. Jumping height, contact time, and jumping index (jumping height/contact time) were measured and calculated using a contact mat/computer system that recorded the contact and air times. The jumping index indicates power. No significant correlation existed between the jumping height and contact time of the lay-up shot jump, the 2 components of the lay-up shot jump index. As a result, jumping height and contact time were found to be mutually independent abilities. The relationships in contact time between the lay-up shot jump to the 1-legged repeated rebound jump and the 2-legged repeated rebound jump were correlated on the same significance levels (p < 0.05). A significant correlation for jumping height existed between the 1-legged repeated rebound jump and the lay-up shot jump (p < 0.05), although none existed for jumping height between the lay-up shot jump and both the 2-legged repeated rebound jump and countermovement jump. The lay-up shot index correlated more strongly to the 1-legged repeated rebound jump index (p < 0.01) when compared to the 2-legged repeated rebound jump index (p < 0.05). These results suggest that the 1-legged repeated rebound jump is effective in improving both contact time and jumping height in the lay-up shot jump.

  20. Oxidation of 2,4-dinitrophenol by hydrogen peroxide in the presence of basic oxygen furnace slag.

    PubMed

    Li, Y S; You, Y H; Lien, E T

    1999-11-01

    A treatment process was developed when basic oxygen furnace slag (BOF slag) and hydrogen peroxide were used to oxidize 2, 4-dinitrophenol from an aqueous solution. BOF slag, final waste slurry from steel making plants, contains about 12.5% by weight of ferrous oxide. In an acid solution, BOF slag can be dissociated to produce ferrous ions and react with hydrogen peroxide to produce hydroxyl radicals and oxidize 2,4-dinitrophenol. The results of the research demonstrated that the process had a significant capacity for oxidation of 2,4-dinitrophenol from the aqueous phase. Various factors critical to the oxidation of 2,4-dinitrophenol were studied, including hydrogen peroxide concentration, concentration of BOF slag, initial concentration of 2,4-dinitrophenol, and pH value of solution. Experimental results proved that 100 mg/L 2, 4-dinitrophenol and its oxidation intermediate could be totally decomposed within 60 min by 10 g/L BOF slag, 0.18 g/L hydrogen peroxide and pH 2.8 +/- 0.2. The optimum hydrogen peroxide concentration for degradation of 100 mg/L of 2,4-dinitrophenol is between 0.09 g/L and 0.18 g/L as 10 g/L BOF slag in the solution of pH 2.8 +/- 0.2. A hydrogen peroxide concentration higher than 0.18 g/L is disadvantageous to the oxidation process. The oxidation efficiency increased with the increase of BOF slag concentration at 0.18 g/L hydrogen peroxide dose. The best pH value of the solution is in the vicinity of 2.8. An oxidation reaction mechanism was proposed for predicting the concentration changes of 2, 4-dinitrophenol, ferrous ion, and hydrogen peroxide.http://link. springer-ny.com/link/service/journals/00244/bibs/37n4p427.++ +html

  1. Structural study of 2,4,6-triisopropylbenzenesulfonyl chloride

    SciTech Connect

    Laba, V. I. Sviridova, A. V.; Nesterov, V. N.

    2009-01-15

    The structure of 2,4,6-triisopropylbenzenesulfonyl chloride (TPSCl) (I) was studied by X-ray diffraction. Compound I is a highly selective condensing agent first suggested by Khorana for the formation of the C3'-C5' interribonucleotide linkage in the oligo- and polyribonucleotide synthesis. I crystals are orthorhombic. At -120 deg. C, the unit-cell parameters are a = 14.184(4) A, b = 11.344(5) A, c = 19.883(6) A, V = 3199(2) A{sup 3}, d{sub calc} = 1.257 g/cm{sup 3}, Z = 8, sp. gr. Pbca. Molecule I adopts a strongly flattened boat conformation with the carbon atoms C-SO{sub 2}Cl (C{sub 1}) and C-i-Pr (C4) of the benzene ring deviating from the bottom of the boat by 0.065(1) and 0.032(1) A, respectively. Molecule I is sterically overcrowded, resulting in an increase in the bond lengths and bond-angle distortions in the fragment containing the SO{sub 2}Cl group and two ortho-i-Pr groups. Nonbonded contacts that are present in the molecule can be considered weak intramolecular hydrogen bonds (for example, the (CH{sub 3}){sub 2}C-H-O=S bond). There is no rotation of the SO{sub 2}Cl, ortho-i-Pr, and CH{sub 3} groups. The above-mentioned facts are, apparently, responsible for the specific selectivity of TPSCl. New readily available sterically hindered arenesulfonyl chlorides were designed.

  2. 1,2,4-triazolium-cation-based energetic salts.

    PubMed

    Darwich, Chaza; Klapötke, Thomas M; Sabaté, Carles Miró

    2008-01-01

    3,4,5-Triamino-1,2,4-triazole (guanazine, 1) can be readily methylated with methyl iodide yielding methylguanazinium iodide (2). Salts containing the novel methylguanazinium cation with energetic anions were synthesised by metathesis reactions with silver azide (3), silver nitrate (4), silver perchlorate (5), sodium 5,5'-azotetrazolate (6), silver 5-nitrotetrazolate (7) and silver dinitramide (8), yielding a new family of heterocycle-based salts, which were fully characterised by analytical (mass spectrometry and elemental analysis) and spectroscopic methods (IR, Raman and NMR). In addition, the molecular structures of all compounds were confirmed by X-ray analysis, revealing extensive hydrogen-bonding in the solid state and densities between 1.399 (3) and 1.669 g cm(-3) (5). The hydrogen-bonded ring motifs are discussed in the formalism of graph-set analysis for hydrogen-bond patterns and compared to each other. Preliminary sensitivity testing of the crystalline compounds indicate surprisingly low sensitivities to both friction and impact, the highest friction and shock sensitivity being found for the perchlorate (5, 220 N) and the dinitramide (8, 20 J) salts, respectively. In addition, DSC analysis was used to assess the thermal stabilities of the compounds: 3-6 melt above 200 degrees C with concomitant decomposition, whereas 7 and 8 have clearly defined melting points at 162 and 129 degrees C, respectively, and with decomposition occurring about 30 degrees C above the melting point. Lastly all compounds have positive calculated heats of formation between 336 (4) and 4070 kJ kg(-1) (6) and calculated detonation velocities in the range between 8330 (7) and 8922 m s(-1) (6) making them of interest as new highly energetic materials with low sensitivity. PMID:18523937

  3. The Use of Quantile Regression to Forecast Higher Than Expected Respiratory Deaths in a Daily Time Series: A Study of New York City Data 1987-2000

    PubMed Central

    Soyiri, Ireneous N.; Reidpath, Daniel D.

    2013-01-01

    Forecasting higher than expected numbers of health events provides potentially valuable insights in its own right, and may contribute to health services management and syndromic surveillance. This study investigates the use of quantile regression to predict higher than expected respiratory deaths. Data taken from 70,830 deaths occurring in New York were used. Temporal, weather and air quality measures were fitted using quantile regression at the 90th-percentile with half the data (in-sample). Four QR models were fitted: an unconditional model predicting the 90th-percentile of deaths (Model 1), a seasonal / temporal (Model 2), a seasonal, temporal plus lags of weather and air quality (Model 3), and a seasonal, temporal model with 7-day moving averages of weather and air quality. Models were cross-validated with the out of sample data. Performance was measured as proportionate reduction in weighted sum of absolute deviations by a conditional, over unconditional models; i.e., the coefficient of determination (R1). The coefficient of determination showed an improvement over the unconditional model between 0.16 and 0.19. The greatest improvement in predictive and forecasting accuracy of daily mortality was associated with the inclusion of seasonal and temporal predictors (Model 2). No gains were made in the predictive models with the addition of weather and air quality predictors (Models 3 and 4). However, forecasting models that included weather and air quality predictors performed slightly better than the seasonal and temporal model alone (i.e., Model 3 > Model 4 > Model 2) This study provided a new approach to predict higher than expected numbers of respiratory related-deaths. The approach, while promising, has limitations and should be treated at this stage as a proof of concept. PMID:24147122

  4. The use of quantile regression to forecast higher than expected respiratory deaths in a daily time series: a study of New York City data 1987-2000.

    PubMed

    Soyiri, Ireneous N; Reidpath, Daniel D

    2013-01-01

    Forecasting higher than expected numbers of health events provides potentially valuable insights in its own right, and may contribute to health services management and syndromic surveillance. This study investigates the use of quantile regression to predict higher than expected respiratory deaths. Data taken from 70,830 deaths occurring in New York were used. Temporal, weather and air quality measures were fitted using quantile regression at the 90th-percentile with half the data (in-sample). Four QR models were fitted: an unconditional model predicting the 90th-percentile of deaths (Model 1), a seasonal/temporal (Model 2), a seasonal, temporal plus lags of weather and air quality (Model 3), and a seasonal, temporal model with 7-day moving averages of weather and air quality. Models were cross-validated with the out of sample data. Performance was measured as proportionate reduction in weighted sum of absolute deviations by a conditional, over unconditional models; i.e., the coefficient of determination (R1). The coefficient of determination showed an improvement over the unconditional model between 0.16 and 0.19. The greatest improvement in predictive and forecasting accuracy of daily mortality was associated with the inclusion of seasonal and temporal predictors (Model 2). No gains were made in the predictive models with the addition of weather and air quality predictors (Models 3 and 4). However, forecasting models that included weather and air quality predictors performed slightly better than the seasonal and temporal model alone (i.e., Model 3 > Model 4 > Model 2) This study provided a new approach to predict higher than expected numbers of respiratory related-deaths. The approach, while promising, has limitations and should be treated at this stage as a proof of concept.

  5. Herbicide 2,4-dichlorophenoxyacetic acid (2,4-D)-induced cytogenetic damage in human lymphocytes in vitro in presence of erythrocytes.

    PubMed

    Soloneski, Sonia; González, Norma V; Reigosa, Miguel A; Larramendy, Marcelo L

    2007-11-01

    The genotoxic effects of 2,4-D and its commercial derivative 2,4-D DMA were studied by measuring sister chromatid exchange (SCE), cell-cycle progression and mitotic index in human whole blood (WBC) and plasma leukocyte cultures (PLC). Concentrations of 10, 25, 50 and 100 microg herbicide/ml were used during 72 h. In WBC, a significant increase in SCE frequency was observed within the 10-50 microg 2,4-D/ml and 25-100 microg 2,4-D DMA/ml dose range. Contrarily, in PLC, none of the concentrations employed affected the SCEs frequency. A significant delay in cell proliferation was observed in WBC after treatments with 25 and 50 microg 2,4-D/ml and 50 and 100 microg 2,4-D DMA/ml. In PLC, only 100.0 microg 2,4-D/ml altered cell-cycle progression. For both chemicals, a progressive dose-related inhibition of mitotic activity was observed. The results demonstrated that the presence of erythrocytes in the culture system modulated the DNA and cellular damage inflicted by 2,4-D and 2,4-D DMA into human lymphocytes in vitro as well as both 2,4-D and 2,4-D DMA were more potent genotoxic agents in the presence of human red cells.

  6. Visual detection of 2,4,6-trinitrotolune by molecularly imprinted colloidal array photonic crystal.

    PubMed

    Lu, Wei; Asher, Sanford A; Meng, Zihui; Yan, Zequn; Xue, Min; Qiu, Lili; Yi, Da

    2016-10-01

    We developed a photonic crystal (PhC) sensor for the quantification of 2,4,6-trinitrotoluene (TNT) in solution. Monodisperse (210nm in diameter) molecularly imprinted colloidal particles (MICs) for TNT were prepared by the emulsion polymerization of methyl methacrylate and acrylamide in the presence of TNT as a template. The MICs were then self-assembled into close-packed opal PhC films. The adsorption capacity of the MICs for TNT was 64mg TNT/g. The diffraction from the PhC depended on the TNT concentration in a methanol/water (3/2, v/v) potassium dihydrogen phosphate buffer solution (pH=7.0, 30mM). The limit of detection (LOD) of the sensor was 1.03μg. The color of the molecularly imprinted colloidal array (MICA) changed from green to red with an 84nm diffraction red shift when the TNT concentration increased to 20mM. The sensor response time was 3min. The PhC sensor was selective for TNT compared to similar compounds such as 2,4,6-trinitrophenol, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2-nitromesitylene, 4-nitrotoluene, 2-nitrotoluene, 1,3-dinitrobenzene, methylbenzene, 4-nitrophenol, 2-nitroaniline, 3-aminophenol and 3-nitroaniline. The sensor showed high stability with little response change after three years storage. This sensor technology might be useful for the visual determination of TNT. PMID:27214001

  7. Degradation of 2,4,6-trinitrotoluene by P. aeruginosa and characterization of some metabolites

    PubMed Central

    Mercimek, Hatice Aysun; Dincer, Sadik; Guzeldag, Gulcihan; Ozsavli, Aysenur; Matyar, Fatih; Arkut, Afet; Kayis, Fikret; Ozdenefe, Melis Sumengen

    2015-01-01

    Degradation of 2,4,6-trinitrotoluene (TNT), a nitroaromatic explosive found in the soil and ground water, was investigated using Pseudomonas aeruginosa in in vitro experiments . Biodegradable abilitiy of this bacteria was performed with 50 and 75 mg L −1 TNT concentrations in a defined liquid medium for 96 h time period. Treatment of TNT in supernatant samples taken at 0, 6, 12, 24, 48, 72 and 96 h from agitated vessels was followed by reverse-phase high-performance liquid chromatography (HPLC). In cultures supplemented with 50 and 75 mgL −1 TNT, after 96 h of incubation 46% and 59% reduction were detected respectively. Two metabolites as degradation intermediates with nitrite release into the medium, 2,4-dinitrotoluene (2,4-DNT) and 4-aminodinitrotoluene (4-ADNT), were elucidated by thin layer chromatography (TLC) and gas chromatography-mass spectrometry (GC-MS). These findings clearly indicate that Pseudomonas aeruginosa can be used in bioremediation of TNT contaminated sites. PMID:26221094

  8. Degradation of 2,4,6-trinitrotoluene by P. aeruginosa and characterization of some metabolites.

    PubMed

    Mercimek, Hatice Aysun; Dincer, Sadik; Guzeldag, Gulcihan; Ozsavli, Aysenur; Matyar, Fatih; Arkut, Afet; Kayis, Fikret; Ozdenefe, Melis Sumengen

    2015-03-01

    Degradation of 2,4,6-trinitrotoluene (TNT), a nitroaromatic explosive found in the soil and ground water, was investigated using Pseudomonas aeruginosa in in vitro experiments . Biodegradable abilitiy of this bacteria was performed with 50 and 75 mg L (-1) TNT concentrations in a defined liquid medium for 96 h time period. Treatment of TNT in supernatant samples taken at 0, 6, 12, 24, 48, 72 and 96 h from agitated vessels was followed by reverse-phase high-performance liquid chromatography (HPLC). In cultures supplemented with 50 and 75 mgL (-1) TNT, after 96 h of incubation 46% and 59% reduction were detected respectively. Two metabolites as degradation intermediates with nitrite release into the medium, 2,4-dinitrotoluene (2,4-DNT) and 4-aminodinitrotoluene (4-ADNT), were elucidated by thin layer chromatography (TLC) and gas chromatography-mass spectrometry (GC-MS). These findings clearly indicate that Pseudomonas aeruginosa can be used in bioremediation of TNT contaminated sites.

  9. Preparation, Characterization and Intracellular Imaging of 2,4-Dichlorophenoxyacetic Acid Conjugated Gold Nanorods.

    PubMed

    Jia, Jin-Liang; Jin, Xiao-Yong; Liu, Qing-Le; Liang, Wen-Long; Lin, Miao-Shan; Xu, Han-Hong

    2016-05-01

    Visualizing the biodistribution of pesticides inside living cells is great importance for enhancing targeting of pesticides. Here we reported for the first time that gold nanorods (Au NRs) with size of 39.4 nm x 11.3 nm could be used as a fluorescent tracer to examine the distribution of a typical herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), in tobacco bright yellow 2 (BY-2) cells. The nanostructures of hybrid materials were analyzed by using Raman spectra and X-ray photoelectron spectroscopy (XPS), including spectra assignments and electronic property. These data revealed 2,4-D has successfully conjugated MP-Au NRs according to Raman and XPS. The biodistribution of the conjugates inside BY-2 cells was directly examined at 12 and 24 h by the two-photon microscopy. The intensity of two-photon luminescence (TPL) inside cells demonstrated that the conjugates could be localized and excluded by BY-2 cells. Thus, this labeling approach opens up new avenues to the facile and efficient labeling of pesticides.

  10. Preparation, Characterization and Intracellular Imaging of 2,4-Dichlorophenoxyacetic Acid Conjugated Gold Nanorods.

    PubMed

    Jia, Jin-Liang; Jin, Xiao-Yong; Liu, Qing-Le; Liang, Wen-Long; Lin, Miao-Shan; Xu, Han-Hong

    2016-05-01

    Visualizing the biodistribution of pesticides inside living cells is great importance for enhancing targeting of pesticides. Here we reported for the first time that gold nanorods (Au NRs) with size of 39.4 nm x 11.3 nm could be used as a fluorescent tracer to examine the distribution of a typical herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), in tobacco bright yellow 2 (BY-2) cells. The nanostructures of hybrid materials were analyzed by using Raman spectra and X-ray photoelectron spectroscopy (XPS), including spectra assignments and electronic property. These data revealed 2,4-D has successfully conjugated MP-Au NRs according to Raman and XPS. The biodistribution of the conjugates inside BY-2 cells was directly examined at 12 and 24 h by the two-photon microscopy. The intensity of two-photon luminescence (TPL) inside cells demonstrated that the conjugates could be localized and excluded by BY-2 cells. Thus, this labeling approach opens up new avenues to the facile and efficient labeling of pesticides. PMID:27483849

  11. Optimization of laccase mediated biodegradation of 2,4-dichlorophenol using genetic algorithm.

    PubMed

    Bhattacharya, S S; Karmakar, S; Banerjee, R

    2009-08-01

    The present investigation focuses on the development of an effective strategy to determine the optimum environmental conditions leading to the maximum rate of biodegradation of 2,4-DCP by coupling response surface methodology (RSM) with a developed genetic algorithm (GA) thereby ensuring minimum contact time. RSM is utilized to create an efficient analytical model for biodegradation of 2,4-DCP in terms of environmental parameters: pH, temperature, enzyme activity and time of incubation. For this purpose, a number of degradation experiments based on statistical three-level Box Behnken design methods were carried out. An effective response surface (RS) model is developed by carrying out experiments designed using the Box Behnken method. The RS model thus developed is further interfaced with the GA to optimize the degradation conditions for optimum degradation with minimum contact time. The GA increases the biodegradation conditions to >99% within a time period of 8h within the given range of experimental conditions. The conditions obtained from GA were verified experimentally.

  12. Biodegradation of 2,4-dinitrophenol with laccase immobilized on nano-porous silica beads

    PubMed Central

    2013-01-01

    Many organic hazardous pollutants, including 2,4-dinitrophenol (2,4-DNP), which are water soluble, toxic, and not easily biodegradable make concerns for environmental pollution worldwide. In the present study, degradation of nitrophenols-contained effluents by using laccase immobilized on the nano-porous silica beads was evaluated. 2,4-DNP was selected as the main constituent of industrial effluents containing nitrophenols. The performance of the system was characterized as a function of pH, contact time, temperature, pollutant, and mediator concentrations. The laccase-silica beads were employed in a mixed-batch reactor to determine the degradation efficiency after 12 h of enzyme treatment. The obtained data showed that the immobilized laccase degraded more than 90% of 2,4-DNP within 12 h treatment. The immobilization process improved the activity and sustainability of laccase for degradation of the pollutant. Temperatures more than 50°C reduced the enzyme activity to about 60%. However, pH and the mediator concentration could not affect the enzyme activity. The degradation kinetic was in accordance with a Michaelis–Menten equation with Vmax and Km obtained as 0.25–0.38 μmoles/min and 0.13–0.017 mM, respectively. The stability of the immobilized enzyme was maintained for more than 85% of its initial activity after 30 days. Based on the results, it can be concluded that high resistibility and reusability of immobilized laccase on CPC-silica beads make it considerable choice for wastewater treatment. PMID:23547870

  13. 40 CFR 180.142 - 2,4-D; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false 2,4-D; tolerances for residues. 180..., plant regulator, and fungicide 2,4-D, including its metabolites and degradates, in or on the commodities... 2,4-D (2,4-dichlorophenoxyacetic acid), both free and conjugated, determined as the acid, in or...

  14. Biological Degradation of 2,4,6-Trinitrotoluene

    PubMed Central

    Esteve-Núñez, Abraham; Caballero, Antonio; Ramos, Juan L.

    2001-01-01

    Nitroaromatic compounds are xenobiotics that have found multiple applications in the synthesis of foams, pharmaceuticals, pesticides, and explosives. These compounds are toxic and recalcitrant and are degraded relatively slowly in the environment by microorganisms. 2,4,6-Trinitrotoluene (TNT) is the most widely used nitroaromatic compound. Certain strains of Pseudomonas and fungi can use TNT as a nitrogen source through the removal of nitrogen as nitrite from TNT under aerobic conditions and the further reduction of the released nitrite to ammonium, which is incorporated into carbon skeletons. Phanerochaete chrysosporium and other fungi mineralize TNT under ligninolytic conditions by converting it into reduced TNT intermediates, which are excreted to the external milieu, where they are substrates for ligninolytic enzymes. Most if not all aerobic microorganisms reduce TNT to the corresponding amino derivatives via the formation of nitroso and hydroxylamine intermediates. Condensation of the latter compounds yields highly recalcitrant azoxytetranitrotoluenes. Anaerobic microorganisms can also degrade TNT through different pathways. One pathway, found in Desulfovibrio and Clostridium, involves reduction of TNT to triaminotoluene; subsequent steps are still not known. Some Clostridium species may reduce TNT to hydroxylaminodinitrotoluenes, which are then further metabolized. Another pathway has been described in Pseudomonas sp. strain JLR11 and involves nitrite release and further reduction to ammonium, with almost 85% of the N-TNT incorporated as organic N in the cells. It was recently reported that in this strain TNT can serve as a final electron acceptor in respiratory chains and that the reduction of TNT is coupled to ATP synthesis. In this review we also discuss a number of biotechnological applications of bacteria and fungi, including slurry reactors, composting, and land farming, to remove TNT from polluted soils. These treatments have been designed to achieve

  15. Biological degradation of 2,4,6-trinitrotoluene.

    PubMed

    Esteve-Núñez, A; Caballero, A; Ramos, J L

    2001-09-01

    Nitroaromatic compounds are xenobiotics that have found multiple applications in the synthesis of foams, pharmaceuticals, pesticides, and explosives. These compounds are toxic and recalcitrant and are degraded relatively slowly in the environment by microorganisms. 2,4,6-Trinitrotoluene (TNT) is the most widely used nitroaromatic compound. Certain strains of Pseudomonas and fungi can use TNT as a nitrogen source through the removal of nitrogen as nitrite from TNT under aerobic conditions and the further reduction of the released nitrite to ammonium, which is incorporated into carbon skeletons. Phanerochaete chrysosporium and other fungi mineralize TNT under ligninolytic conditions by converting it into reduced TNT intermediates, which are excreted to the external milieu, where they are substrates for ligninolytic enzymes. Most if not all aerobic microorganisms reduce TNT to the corresponding amino derivatives via the formation of nitroso and hydroxylamine intermediates. Condensation of the latter compounds yields highly recalcitrant azoxytetranitrotoluenes. Anaerobic microorganisms can also degrade TNT through different pathways. One pathway, found in Desulfovibrio and Clostridium, involves reduction of TNT to triaminotoluene; subsequent steps are still not known. Some Clostridium species may reduce TNT to hydroxylaminodinitrotoluenes, which are then further metabolized. Another pathway has been described in Pseudomonas sp. strain JLR11 and involves nitrite release and further reduction to ammonium, with almost 85% of the N-TNT incorporated as organic N in the cells. It was recently reported that in this strain TNT can serve as a final electron acceptor in respiratory chains and that the reduction of TNT is coupled to ATP synthesis. In this review we also discuss a number of biotechnological applications of bacteria and fungi, including slurry reactors, composting, and land farming, to remove TNT from polluted soils. These treatments have been designed to achieve

  16. [Longer waiting time and higher mortality in older people with traumatic brain injuries. Mapping of emergency prehospital management and hospital management in Västerbotten].

    PubMed

    Holzmann, Martin; Bylund, Per O; Degerfält, Lisa; Carlsson, Axel C; Wändell, Per; Ruge, Toralph

    2015-01-01

    The main purpose was to study the prehospital and early intrahospital treatment of patients with traumatic brain injury (TBI) in the county of Västerbotten 2011-2012. In total, 162 patients were included. The main finding was that a large proportion of TBI patients were older men who fell in the same or from a different level. Older patients had higher mortality and had to wait longer for diagnostic imaging compared to younger patients. Furthermore, most patients were initially relatively unaffected by the injury and around 1/5 of the patients were transported to hospital by private transport. Finally, we observed that most patients were admitted to hospital and computer tomography scan of the head was performed within 4 hours. PMID:26440946

  17. [Longer waiting time and higher mortality in older people with traumatic brain injuries. Mapping of emergency prehospital management and hospital management in Västerbotten].

    PubMed

    Holzmann, Martin; Bylund, Per O; Degerfält, Lisa; Carlsson, Axel C; Wändell, Per; Ruge, Toralph

    2015-10-06

    The main purpose was to study the prehospital and early intrahospital treatment of patients with traumatic brain injury (TBI) in the county of Västerbotten 2011-2012. In total, 162 patients were included. The main finding was that a large proportion of TBI patients were older men who fell in the same or from a different level. Older patients had higher mortality and had to wait longer for diagnostic imaging compared to younger patients. Furthermore, most patients were initially relatively unaffected by the injury and around 1/5 of the patients were transported to hospital by private transport. Finally, we observed that most patients were admitted to hospital and computer tomography scan of the head was performed within 4 hours.

  18. Transient effects of 2,4-dichlorophenoxyacetic acid (2,4-D) exposure on some metabolic and free radical processes in goldfish white muscle.

    PubMed

    Kubrak, Olga I; Atamaniuk, Tetiana M; Husak, Viktor V; Lushchak, Volodymyr I

    2013-09-01

    This study aims to assess effects of 96 h goldfish exposure to 1, 10 and 100 mg/L of the herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), on metabolic indices and free radical process markers in white muscle of a commercial fish, the goldfish Carassius auratus L. Most oxidative stress markers and antioxidant enzymes were not affected at 2,4-D fish treatment. 2,4-D fish exposure induced the elevated levels of total (by 46% and 40%) and reduced (by 77% and 73%) glutathione in muscles of goldfish of 10 mg/L 2,4-D and recovery (after 100 mg/L of 2,4-D exposure) groups, respectively. However, in muscles of 100 mg/L 2,4-D exposed goldfish these parameters were depleted (by 47% and 64%). None of investigated parameters of protein and carbohydrate metabolisms changed in white muscles of 2,4-D exposed fish, with exception of lactate dehydrogenase activity, which was slightly (by 11-15%) elevated in muscles of goldfish exposed to 10-100 mg/L of 2,4-D, but also recovered. Thus, the short term exposure of goldfish to the selected concentrations of 2,4-D does not substantially affect their white muscle, suggesting the absence of any effect under the environmentally relevant concentrations. PMID:23806294

  19. Compounds 2,4,6-trinitrotoluene and 2,4-diamino-6-nitrotoluene: The absence of recA-dependent mutagenesis

    SciTech Connect

    Karamova, N.S.; Mynina, I.I.; Garaeva, G.G.

    1995-05-01

    The genotoxicity of 2,4,6-trinitrotoluene (2,4,6-TNT) and its amino derivative, 2,4-diamino-6-nitrotoluene (2,4-DA-6-NT), was studied using the Escherichia coli tester strain PQ37 in the SOS chromotest. The compound 2,4,6-TNT, without metabolic activation, virtually failed to induce an SOS effect in cells of the tester bacteria. Consequently, mutagenic activity of 2,4,6-TNT, which was shown earlier in the Ames test, does not depend on SOS mutagenesis. It was demonstrated that metabolic activation with the microsomal S9 human placenta fraction results in a threefold increase in the induction factor of the SOS effect caused by 2,4,6-TNT. The absence of the SOS-inducing activity of 2,4-DA-6-NT, regardless of the presence of a microsomal activating mixture, is shown. Thus, 2,4-DA-6-NT does not belong to metabolites of 2,4,6-TNT, responsible for the genotoxicity of this compound. 25 refs., 1 fig., 2 tabs.

  20. Transient effects of 2,4-dichlorophenoxyacetic acid (2,4-D) exposure on some metabolic and free radical processes in goldfish white muscle.

    PubMed

    Kubrak, Olga I; Atamaniuk, Tetiana M; Husak, Viktor V; Lushchak, Volodymyr I

    2013-09-01

    This study aims to assess effects of 96 h goldfish exposure to 1, 10 and 100 mg/L of the herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), on metabolic indices and free radical process markers in white muscle of a commercial fish, the goldfish Carassius auratus L. Most oxidative stress markers and antioxidant enzymes were not affected at 2,4-D fish treatment. 2,4-D fish exposure induced the elevated levels of total (by 46% and 40%) and reduced (by 77% and 73%) glutathione in muscles of goldfish of 10 mg/L 2,4-D and recovery (after 100 mg/L of 2,4-D exposure) groups, respectively. However, in muscles of 100 mg/L 2,4-D exposed goldfish these parameters were depleted (by 47% and 64%). None of investigated parameters of protein and carbohydrate metabolisms changed in white muscles of 2,4-D exposed fish, with exception of lactate dehydrogenase activity, which was slightly (by 11-15%) elevated in muscles of goldfish exposed to 10-100 mg/L of 2,4-D, but also recovered. Thus, the short term exposure of goldfish to the selected concentrations of 2,4-D does not substantially affect their white muscle, suggesting the absence of any effect under the environmentally relevant concentrations.

  1. Synthesis of 2,4,8,10-tetroxaspiro5,5undecane

    NASA Technical Reports Server (NTRS)

    Poshkus, A. C. (Inventor)

    1985-01-01

    Pentaerythritol is converted to its diformal, 2,4,8,10-tetroxaspirol5.5undecane, by heating it to a temperature within the range of about 110 to 150 C, for a period of up to 10 minutes, in the presence of a slight excess of paraformaldehyde and of a catalytic quantity of an acid catalyst such as sulfuric acid. The reaction may be carried out in two steps, by forming first the monoformal, then the diformal. In any case, total reaction time is about 10 minutes, and yield of diformal are greater than 90%. Previous processes require hours or days, and often, tedious operating procedures.

  2. Effect of 2,4-Thiazolidinedione on Limousin Cattle Growth and on Muscle and Adipose Tissue Metabolism

    PubMed Central

    Arévalo-Turrubiarte, M.; González-Dávalos, L.; Yabuta, A.; Garza, J. D.; Dávalos, J. L.; Mora, O.; Shimada, A.

    2012-01-01

    The main adipogenic transcription factor PPARγ possesses high affinity to 2,4-TZD, a member of the Thiazolidinedione family of insulin-sensitizing compounds used as adipogenic agents. We evaluated 2,4-TZD's effect on bovine growth and PPAR tissue expression. Seventeen Limousin bulls (18 month-old; 350 kg body weight (BW)) were assigned into 2 treatments: control and 2,4-TZD (8 mg/70 kg BW) and were fed until bulls reached 500 kg BW. They were weighed and their blood was sampled. DNA, RNA, and protein were determined in liver; skeletal muscle; subcutaneous (SC), omental, perirenal adipose tissues (AT) to determine protein synthesis rate and cellular size. Expression of PPAR mRNA was measured in liver and muscle (PPARα, -δ, and -γ) and SC adipose tissue (γ) by real-time PCR. No significant differences were found (P > 0.1) in weight gain, days on feed, and carcass quality. Muscle synthesis was greater in controls (P < 0.05); cell size was larger with 2,4-TZD (P < 0.05). PPARα, -δ, and -γ expressions with 2,4-TZD in liver were lower (P < 0.01) than in muscle. No differences were found for PPARγ mRNA expression in SCAT. The results suggest the potential use of 2,4-TZD in beef cattle diets, because it improves AT differentiation, liver, and muscle fatty acid oxidation that, therefore, might improve energy efficiency. PMID:23304114

  3. Oxidative stress and metabolic perturbations in Escherichia coli exposed to sublethal levels of 2,4-dichlorophenoxyacetic acid.

    PubMed

    Bhat, Supriya V; Booth, Sean C; Vantomme, Erik A N; Afroj, Shirin; Yost, Christopher K; Dahms, Tanya E S

    2015-09-01

    The chlorophenoxy herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is used extensively worldwide despite its known toxicity and our limited understanding of how it affects non-target organisms. Escherichia coli is a suitable model organism to investigate toxicity and adaptation mechanisms in bacteria exposed to xenobiotic chemicals. We developed a methodical platform that uses atomic force microscopy, metabolomics and biochemical assays to quantify the response of E. coli exposed to sublethal levels of 2,4-D. This herbicide induced a filamentous phenotype in E. coli BL21 and a similar phenotype was observed in a selection of genotypically diverse E. coli strains (A0, A1, B1, and D) isolated from the environment. The filamentous phenotype was observed at concentrations 1000 times below field levels and was reversible upon supplementation with polyamines. Cells treated with 2,4-D had more compliant envelopes, significantly remodeled surfaces that were rougher and altered vital metabolic pathways including oxidative phosphorylation, the ABC transport system, peptidoglycan biosynthesis, amino acid, nucleotide and sugar metabolism. Most of the observed effects could be attributed to oxidative stress, consistent with increases in reactive oxygen species as a function of 2,4-D exposure. This study provides direct evidence that 2,4-D at sublethal levels induces oxidative stress and identifies the associated metabolic changes in E. coli.

  4. Numerical approximation of higher-order time-fractional telegraph equation by using a combination of a geometric approach and method of line

    NASA Astrophysics Data System (ADS)

    Hashemi, M. S.; Baleanu, D.

    2016-07-01

    We propose a simple and accurate numerical scheme for solving the time fractional telegraph (TFT) equation within Caputo type fractional derivative. A fictitious coordinate ϑ is imposed onto the problem in order to transform the dependent variable u (x , t) into a new variable with an extra dimension. In the new space with the added fictitious dimension, a combination of method of line and group preserving scheme (GPS) is proposed to find the approximate solutions. This method preserves the geometric structure of the problem. Power and accuracy of this method has been illustrated through some examples of TFT equation.

  5. Biotransformation of 2,4,6-trinitrotoluene in Anabaena sp. cultures

    SciTech Connect

    Pavlostathis, S.G.; Jackson, G.H.

    1999-03-01

    The transformation of 2,4,6-trinitrotoluene (TNT) was investigated in cultures of the cyanobacterium Anabaena sp. by conducting a series of batch assays. 2,4,6-Trinitrotoluene was added to Anabaena sp. cultures in single and consecutive additions, at various initial concentrations, to determine its transformation kinetics, to identify products formed, to evaluate potential toxicity, and to determine the effect of light deprivation on the TNT transformation process. 2,4,6-Trinitrotoluene disappearance occurred only in the presence of Anabaena sp. cultures maintained under a normal 16-h photoperiod. Toxicity leading to culture chlorosis and death was observed in batch systems with an initial TNT concentration greater than 10 mg/L. A low rate and extent of TNT disappearance was observed in light-deprived cultures, which were inhibited even at low TNT concentrations. At pH values between 7.5 and 8.5, azoxy-tetranitrotoluene isomers were detected in both the culture medium and solvent extracts of biomass and accounted for only 20 and 4.4% of the initially added TNT moles, respectively. At a culture pH range between 5.6 and 5.9, achieved by aeration with a 5% CO{sub 2}/air mixture, hydroxylaminodinitrotoluene equimolar to the TNT addition was produced and then depleted from the culture medium with prolonged incubation. Although TNT reduction in Anabaena sp. cultures occurred, yielding low levels of azoxy-tetranitrotoluene isomers or hydroxylaminodinitrotoluene, uptake and other transformation reactions of TNT and/or its transformation products by Anabaena sp. may have taken place. Based on a less than 15% observed increase of biomass concentration over the relatively short incubation periods and by considering the mean biomass concentration constant, the TNT disappearance rate followed pseudo-first-order kinetics. The biomass carbon-normalized TNT disappearance rates in Anabaena sp. cultures were about three orders of magnitude higher than previously reported TNT

  6. Determining fate and transport parameters for nitroglycerine, 2,4-dinitrotoluine, and nitroguanidine in soils

    NASA Astrophysics Data System (ADS)

    Gosch, D. L.; Dontsova, K.; Chorover, J.; Ferré, T.; Taylor, S.

    2010-12-01

    During military operations, a small fraction of propellant mass is not consumed during firing and is deposited onto the ground surface (Jenkins et al., 2006). Soluble propellant constituents can be released from particulate residues into the environment. Propellant constituents of interest for this study are nitroglycerine (NG), 2,4-dinitrotoluine (2,4-DNT), 2,6-dinitrotoluine (2,6-DNT), and nitroguanidine (NQ). The goal of this work is to determine fate and transport parameters for these constituents in three soils that represent a range of geographic locations and soil properties. This supports a companion study that looks at dissolution of NG, 2,4-DNT, 2,6-DNT, and NQ from fired and unfired solid propellant formulations and their transport in soils. The three soils selected for the study are Catlin silt loam (fine-silty, mixed, mesic, superactive Oxyaquic Argiudoll), Plymouth sandy loam (mesic, coated Typic Quartzipsamment), and Sassafras loam (fine loamy, siliceous, mesic Typic Hapudult). Two of these soils, Plymouth sandy loam and Sassafras loam, were collected on military installations. Linear adsorption coefficients and transformation rates of propellant constituents were determined in batch kinetic experiments. Soils were mixed with propellant constituent solutions (2 mg L-1) at 4:1 solution/soil mass ratio and equilibrated for 0, 1, 2, 6, 12, 24, 48, and 120 hr at which time samples were centrifuged and supernatant solutions were analyzed for target compounds by high performance liquid chromatography (HPLC) using U.S. EPA Method 8330b for NG, 2,4-DNT, and 2,6-DNT, and Walsh (1989) method for NQ. Adsorption and transformation of propellant constituents were determined from the decrease in solution concentration of these compounds. It was determined that all studied compounds were subjected to sorption by the solid phase and degradation. Catlin soil, with finer texture and high organic matter content, influenced solution concentration of NG, 2,4-DNT, 2,6-DNT

  7. Dechlorination of 2,4-dichlorophenoxyacetic acid by sodium carboxymethyl cellulose-stabilized Pd/Fe nanoparticles.

    PubMed

    Zhou, Hongyi; Han, Jian; Baig, Shams Ali; Xu, Xinhua

    2011-12-30

    This paper describes the synthesis of sodium carboxymethyl cellulose (CMC)-stabilized Pd/Fe nanoparticles and their applications to the dechlorination of 2,4-dichlorophenoxyacetic acid (2,4-D) under controlled laboratorial conditions. For this purpose batch mode experiments were conducted to understand the effects of CMC on the surface characteristics of Pd/Fe nanoparticles, optimum removal of 2,4-D and other surface interactions mechanism. Our experimental results demonstrated considerable enhancements in particle stability and chemical reactivity with the addition of CMC to Pd/Fe nanoparticles. Transmission electron microscopy (TEM) analysis indicated that CMC-stabilized Pd/Fe nanoparticles were well dispersed, and nanoparticles remained in suspension for days compared to non-stabilized Pd/Fe nanoparticles precipitated within minutes. The isoelectric point (IEP) of the nanoparticles shifted from pH 6.5 to 2.5, suggesting that CMC-stabilized Pd/Fe nanoparticles were negatively charged over a wider pH range. Our batch experiments demonstrated that CMC-stabilized Pd/Fe nanoparticles (0.6 g Fe L(-1)) were able to remove much higher levels of 2,4-D with only one intermediate 2-chlorophenoxyacetic acid (2-CPA) and the final organic product phenoxyacetic acid (PA), than non-stabilized Pd/Fe nanoparticles or microsized Pd/Fe particles. The removal percentage of 2,4-D increased from 10% to nearly 100% as the reaction pH decreased from 11.5 to 2.5. The optimal CMC/Fe mass ratio for the dechlorination of 2,4-D was determined to be 5/1, and the removal of 2,4-D was evidently hindered by an overdose of CMC.

  8. Benchmarks on automated system and software generation higher flexibility increased productivity and shorter time-to-market by ScaPable software

    NASA Astrophysics Data System (ADS)

    Gerlich, Rainer

    2002-07-01

    "ScaPable" is an acronym derived from "scalable" and "portable". The attribute "scalable" indicates that specific application software can automatically be built from scratch and verified without writing any statement in a programming language like C, thereby covering a large variety of embedded and/or distributed applications. The term "portable" addresses the capability to automatically port parts of such an application from one physical node to another one - the processor and operating system type may change - only requiring the names of the nodes, their processor type and operating system. This way the infrastructure of an embedded / distributed system can be built just by provision of literals and figures which define the system interaction, communication, topology and performance. Moreover, dedicated application software like needed for on-board command handling, data acquisition and processing, and telemetry handling can be built from generic templates. The generation time range from less than one second up to about twenty minutes on a PC/Linux platform (800 MHz). By this extremely short generation time risks can be identified early because the executable application is immediately available for validation. A rough estimation shows that one hour of automated system and software generation is equivalent to about 5 .. 50 man years. Currently, about 50% of a typical space embedded system can be covered by the available automated approach. However, the more it is applied, the more can be covered by automation. A system is constructed by applying a formal transformation to the few information as delivered by the user. This approach is not limited to the space domain, although the first industrial application was a space project. Quite different domains can take advantage of such principles of system construction. This paper explains the approach, compares it with other approaches, and provides figures on productivity, duration of system generation and reliability.

  9. Royal Ordnance 2.4 MJ multi-module capacitor bank

    SciTech Connect

    Augsburger, B.; Smith, B.; McNab, I.R.; Chen, Y.G.; Hewkin, D.; Vance, K.; Disley, C.

    1995-01-01

    Maxwell Laboratories Inc. has designed and manufactured a 2.4 MJ multi-module capacitor bank to be used for the investigation of ETC technologies. The system was installed and accepted at the Royal Ordnance (R.O.) Faldingworth facility during the fall of 1993. This paper will discuss the pulsed power system design and typical test data acquired during manufacturing testing. The 2.4 MJ system is comprised of eight independent 300 kJ modules with a dual operating voltage of 11 kV and 22 kV, both voltages capable of the full 300 kJ energy storage. The capacitor bank modularity provides the user with pulse shaping flexibility by allowing for time-sequence firing of the eight 300 kJ units. The 2.4 MJ system can be operated in 300 kJ increments, allowing the user to control the energy storage volume needed for laboratory type testing. Each 300 kJ module is a stand alone capacitor bank equipped with six Maxwell 11/22 kV 50 kJ capacitors, two parallel output switches (Maxwell Triggered Vacuum Switch, TVS-40), output inductor, trigger generator, energy dumping system, and Maxwell designed fiber optic control circuits. This system was tested to demonstrate the overall electrical performance and power profile flexibility into a resistive load. Data will be presented to show the capacitor bank current output pulse variations, both in single-shot and time-sequence operation. The data will show the advantages of such a capacitor bank for laboratory type experiments and future fieldable energy storage systems.

  10. Biodegradation of 2,4-dichlorophenol in the presence of volatile organic compounds in soils under different vegetation types.

    PubMed

    Rhodes, Angela H; Owen, Susan M; Semple, Kirk T

    2007-04-01

    It has been suggested that monoterpenes emitted within the soil profile, either by roots or by decaying biomass, may enhance the biodegradation of organic pollutants. The aim of this study was to evaluate the effect of biogenic volatile organic compounds (VOCs) on the catabolism of 2,4-dichlorophenol in soils. Soils were collected from areas surrounding monoterpene (woodland) and nonmonoterpene (grassland)-emitting vegetation types. Soils were spiked with [UL-14C] 2,4-dichlorophenol at 10 mg kg(-1) and amended with alpha-pinene, p-cymene or a mix of monoterpenes (alpha-pinene, limonene and p-cymene in 1:1:1 ratio). The effects of monoterpene addition on the catabolism of [UL-14C] 2,4-dichlorophenol to 14CO2 by indigenous soil microbial communities were assessed in freshly spiked and 4-week-aged soils. It was found that aged woodland soils exhibited a higher level of [UL-14C] 2,4-dichlorophenol degradation, which was subsequently enhanced by the addition of monoterpenes (P<0.001), with the VOC mix and alpha-pinene amendments showing increased [UL-14C] 2,4-dichlorophenol catabolism. This study supports claims that the addition of biogenic VOCs to soils enhances the degradation of xenobiotic contaminants. PMID:17391503

  11. Regulation and function of cytochrome c' in Rhodobacter sphaeroides 2.4.3.

    PubMed

    Choi, Peter S; Grigoryants, Vladimir M; Abruña, Hector D; Scholes, Charles P; Shapleigh, James P

    2005-06-01

    Cytochrome c' (Cyt c') is a c-type cytochrome with a pentacoordinate heme iron. The gene encoding this protein in Rhodobacter sphaeroides 2.4.3, designated cycP, was isolated and sequenced. Northern blot analysis and beta-galactosidase assays demonstrated that cycP transcription increased as oxygen levels decreased and was not repressed under denitrifying conditions as observed in another Rhodobacter species. CO difference spectra performed with extracts of cells grown under different conditions revealed that Cyt c' levels were highest during photosynthetic denitrifying growth conditions. The increase in Cyt c' under this condition was higher than would be predicted from transcriptional studies. Electron paramagnetic resonance analysis of whole cells demonstrated that Cyt c' binds NO during denitrification. Mass spectrometric analysis of nitrogen oxides produced by cells and purified protein did not indicate that Cyt c' has NO reductase activity. Taken together, these results suggest a model where Cyt c' in R. sphaeroides 2.4.3 may shuttle NO to the membrane, where it can be reduced.

  12. Toxicokinetic Model Development for the Insensitive Munitions Component 2,4-Dinitroanisole.

    PubMed

    Sweeney, Lisa M; Goodwin, Michelle R; Hulgan, Angela D; Gut, Chester P; Bannon, Desmond I

    2015-01-01

    The Armed Forces are developing new explosives that are less susceptible to unintentional detonation (insensitive munitions [IMX]). 2,4-Dinitroanisole (DNAN) is a component of IMX. Toxicokinetic data for DNAN are required to support interpretation of toxicology studies and refinement of dose estimates for human risk assessment. Male Sprague-Dawley rats were dosed by gavage (5, 20, or 80 mg DNAN/kg), and blood and tissue samples were analyzed to determine the levels of DNAN and its metabolite 2,4-dinitrophenol (DNP). These data and data from the literature were used to develop preliminary physiologically based pharmacokinetic (PBPK) models. The model simulations indicated saturable metabolism of DNAN in rats at higher tested doses. The PBPK model was extrapolated to estimate the toxicokinetics of DNAN and DNP in humans, allowing the estimation of human-equivalent no-effect levels of DNAN exposure from no-observed adverse effect levels determined in laboratory animals, which may guide the selection of exposure limits for DNAN.

  13. Selection and Validation of Reference Genes for Quantitative Real-Time Polymerase Chain Reaction Studies in Mossy Maze Polypore, Cerrena unicolor (Higher Basidiomycetes).

    PubMed

    Yang, Jie; Lin, Qi; Lin, Juan; Ye, Xiuyun

    2016-01-01

    With its ability to produce ligninolytic enzymes such as laccases, white-rot basidiomycete Cerrena unicolor, a medicinal mushroom, has great potential in biotechnology. Elucidation of the expression profiles of genes encoding ligninolytic enzymes are important for increasing their production. Quantitative real-time polymerase chain reaction (qPCR) is a powerful tool to study transcriptional regulation of genes of interest. To ensure accuracy and reliability of qPCR analysis of C. unicolor, expression levels of seven candidate reference genes were studied at different growth phases, under various induction conditions, and with a range of carbon/nitrogen ratios and carbon and nitrogen sources. The stability of the genes were analyzed with five statistical approaches, namely geNorm, NormFinder, BestKeeper, the ΔCt method, and RefFinder. Our results indicated that the selection of reference genes varied with sample sets. A combination of four reference genes (Cyt-c, ATP6, TEF1, and β-tubulin) were recommended for normalizing gene expression at different growth phases. GAPDH and Cyt-c were the appropriate reference genes under different induction conditions. ATP6 and TEF1 were most stable in fermentation media with various carbon/nitrogen ratios. In the fermentation media with various carbon or nitrogen sources, 18S rRNA and GAPDH were the references of choice. The present study represents the first validation analysis of reference genes in C. unicolor and serves as a foundation for its qPCR analysis. PMID:27279538

  14. Multidimensional profiling of CSF1R screening hits and inhibitors: assessing cellular activity, target residence time, and selectivity in a higher throughput way.

    PubMed

    Uitdehaag, Joost C M; Sünnen, Cecile M; van Doornmalen, Antoon M; de Rouw, Nikki; Oubrie, Arthur; Azevedo, Rita; Ziebell, Michael; Nickbarg, Elliott; Karstens, Willem-Jan; Ruygrok, Simone

    2011-10-01

    Over the past years, improvements in high-throughput screening (HTS) technology and compound libraries have resulted in a dramatic increase in the amounts of good-quality screening hits, and there is a growing need for follow-on hit profiling assays with medium throughput to further triage hits. Here the authors present such assays for the colony-stimulating factor 1 receptor (CSF1R, Fms), including tests for cellular activity and a homogeneous assay to measure affinity for inactive CSF1R. They also present a high-throughput assay to measure target residence time, which is based on competitive binding kinetics. To better fit k(off) rates, they present a modified mathematical model for competitive kinetics. In all assays, they profiled eight reference inhibitors (imatinib, sorafenib, sunitinib, tandutinib, dasatinib, GW2580, Ki20227, and J&J's pyrido[2,3-d]pyrimidin-5-one). Using the known biochemical selectivities of these inhibitors, which can be quantified using metrics such as the selectivity entropy, the authors have determined which assay readout best predicts hit selectivity. Their profiling shows surprisingly that imatinib has a preference for the active form of CSF1R and that Ki20227 has an unusually slow target dissociation rate. This confirms that follow-on hit profiling is essential to ensure that the best hits are selected for lead optimization.

  15. Natural selection for 2,4,5-trichlorophenoxyacetic acid mineralizing bacteria in agent orange contaminated soil.

    PubMed

    Rice, J F; Menn, F M; Hay, A G; Sanseverino, J; Sayler, G S

    2005-12-01

    Agent Orange contaminated soils were utilized in direct enrichment culture studies to isolate 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and 2,4-dichlorophenoxyacetic acid (2,4-D) mineralizing bacteria. Two bacterial cultures able to grow at the expense of 2,4,5-T and/or 2,4-D were isolated. The 2,4,5-T degrading culture was a mixed culture containing two bacteria, Burkholderia species strain JR7B2 and Burkholderia species strain JR7B3. JR7B3 was able to metabolize 2,4,5-T as the sole source of carbon and energy, and demonstrated the ability to affect metabolism of 2,4-D to a lesser degree. Strain JR7B3 was able to mineralize 2,4,5-T in pure culture and utilized 2,4,5-T in the presence of 0.01% yeast extract. Subsequent characterization of the 2,4-D degrading culture showed that one bacterium, Burkholderia species strain JRB1, was able to utilize 2,4-D as a sole carbon and energy source in pure culture. Polymerase chain reaction (PCR) experiments utilizing known genetic sequences from other 2,4-D and 2,4,5-T degrading bacteria demonstrated that these organisms contain gene sequences similar to tfdA, B, C, E, and R (Strain JRB1) and the tftA, C, and E genes (Strain JR7B3). Expression analysis confirmed that tftA, C, and E and tfdA, B, and C were transcribed during 2,4,5-T and 2,4-D dependent growth, respectively. The results indicate a strong selective pressure for 2,4,5-T utilizing strains under field condition. PMID:15865343

  16. Natural selection for 2,4,5-trichlorophenoxyacetic acid mineralizing bacteria in agent orange contaminated soil.

    PubMed

    Rice, J F; Menn, F M; Hay, A G; Sanseverino, J; Sayler, G S

    2005-12-01

    Agent Orange contaminated soils were utilized in direct enrichment culture studies to isolate 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and 2,4-dichlorophenoxyacetic acid (2,4-D) mineralizing bacteria. Two bacterial cultures able to grow at the expense of 2,4,5-T and/or 2,4-D were isolated. The 2,4,5-T degrading culture was a mixed culture containing two bacteria, Burkholderia species strain JR7B2 and Burkholderia species strain JR7B3. JR7B3 was able to metabolize 2,4,5-T as the sole source of carbon and energy, and demonstrated the ability to affect metabolism of 2,4-D to a lesser degree. Strain JR7B3 was able to mineralize 2,4,5-T in pure culture and utilized 2,4,5-T in the presence of 0.01% yeast extract. Subsequent characterization of the 2,4-D degrading culture showed that one bacterium, Burkholderia species strain JRB1, was able to utilize 2,4-D as a sole carbon and energy source in pure culture. Polymerase chain reaction (PCR) experiments utilizing known genetic sequences from other 2,4-D and 2,4,5-T degrading bacteria demonstrated that these organisms contain gene sequences similar to tfdA, B, C, E, and R (Strain JRB1) and the tftA, C, and E genes (Strain JR7B3). Expression analysis confirmed that tftA, C, and E and tfdA, B, and C were transcribed during 2,4,5-T and 2,4-D dependent growth, respectively. The results indicate a strong selective pressure for 2,4,5-T utilizing strains under field condition.

  17. Establishment of Immortalized BMP2/4 Double Knock-Out Osteoblastic Cells Is Essential for Study of Osteoblast Growth, Differentiation, and Osteogenesis.

    PubMed

    Wu, Li-An; Wang, Feng; Donly, Kevin J; Baker, Andrew; Wan, Chunyan; Luo, Daoshu; MacDougall, Mary; Chen, Shuo

    2016-06-01

    Bone morphogenetic proteins 2 and 4 (BMP2/4) are essential for osteoblast differentiation and osteogenesis. Generation of a BMP2/4 dual knock-out ((ko/ko)) osteoblastic cell line is a valuable asset for studying effects of BMP2/4 on skeletal development. In this study, our goal was to create immortalized mouse deleted BMP2/4 osteoblasts by infecting adenoviruses with Cre recombinase and green fluorescent protein genes into immortalized murine floxed BMP2/4 osteoblasts. Transduced BMP2/4(ko/ko) cells were verified by green immunofluorescence and PCR. BMP2/4(ko/ko) osteoblasts exhibited small size, slow cell proliferation rate and cell growth was arrested in G1 and G2 phases. Expression of bone-relate genes was reduced in the BMP2/4(ko/ko) cells, resulting in delay of cell differentiation and mineralization. Importantly, extracellular matrix remodeling was impaired in the BMP2/4(ko/ko) osteoblasts as reflected by decreased Mmp-2 and Mmp-9 expressions. Cell differentiation and mineralization were rescued by exogenous BMP2 and/or BMP4. Therefore, we for the first time described establishment of an immortalized deleted BMP2/4 osteoblast line useful for study of mechanisms in regulating osteoblast lineages. PMID:26595646

  18. Establishment of Immortalized BMP2/4 Double Knock-Out Osteoblastic Cells Is Essential for Study of Osteoblast Growth, Differentiation, and Osteogenesis.

    PubMed

    Wu, Li-An; Wang, Feng; Donly, Kevin J; Baker, Andrew; Wan, Chunyan; Luo, Daoshu; MacDougall, Mary; Chen, Shuo

    2016-06-01

    Bone morphogenetic proteins 2 and 4 (BMP2/4) are essential for osteoblast differentiation and osteogenesis. Generation of a BMP2/4 dual knock-out ((ko/ko)) osteoblastic cell line is a valuable asset for studying effects of BMP2/4 on skeletal development. In this study, our goal was to create immortalized mouse deleted BMP2/4 osteoblasts by infecting adenoviruses with Cre recombinase and green fluorescent protein genes into immortalized murine floxed BMP2/4 osteoblasts. Transduced BMP2/4(ko/ko) cells were verified by green immunofluorescence and PCR. BMP2/4(ko/ko) osteoblasts exhibited small size, slow cell proliferation rate and cell growth was arrested in G1 and G2 phases. Expression of bone-relate genes was reduced in the BMP2/4(ko/ko) cells, resulting in delay of cell differentiation and mineralization. Importantly, extracellular matrix remodeling was impaired in the BMP2/4(ko/ko) osteoblasts as reflected by decreased Mmp-2 and Mmp-9 expressions. Cell differentiation and mineralization were rescued by exogenous BMP2 and/or BMP4. Therefore, we for the first time described establishment of an immortalized deleted BMP2/4 osteoblast line useful for study of mechanisms in regulating osteoblast lineages.

  19. Establishment of Immortalized BMP2/4 Double Knock‐Out Osteoblastic Cells Is Essential for Study of Osteoblast Growth, Differentiation, and Osteogenesis

    PubMed Central

    Wu, Li‐An; Wang, Feng; Donly, Kevin J.; Baker, Andrew; Wan, Chunyan; Luo, Daoshu; MacDougall, Mary

    2015-01-01

    Bone morphogenetic proteins 2 and 4 (BMP2/4) are essential for osteoblast differentiation and osteogenesis. Generation of a BMP2/4 dual knock‐out (ko/ko) osteoblastic cell line is a valuable asset for studying effects of BMP2/4 on skeletal development. In this study, our goal was to create immortalized mouse deleted BMP2/4 osteoblasts by infecting adenoviruses with Cre recombinase and green fluorescent protein genes into immortalized murine floxed BMP2/4 osteoblasts. Transduced BMP2/4ko/ko cells were verified by green immunofluorescence and PCR. BMP2/4ko/ko osteoblasts exhibited small size, slow cell proliferation rate and cell growth was arrested in G1 and G2 phases. Expression of bone‐relate genes was reduced in the BMP2/4ko/ko cells, resulting in delay of cell differentiation and mineralization. Importantly, extracellular matrix remodeling was impaired in the BMP2/4ko/ko osteoblasts as reflected by decreased Mmp‐2 and Mmp‐9 expressions. Cell differentiation and mineralization were rescued by exogenous BMP2 and/or BMP4. Therefore, we for the first time described establishment of an immortalized deleted BMP2/4 osteoblast line useful for study of mechanisms in regulating osteoblast lineages. J. Cell. Physiol. 231: 1189–1198, 2016. © 2015 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc. PMID:26595646

  20. TaSnRK2.4, an SNF1-type serine/threonine protein kinase of wheat (Triticum aestivum L.), confers enhanced multistress tolerance in Arabidopsis

    PubMed Central

    Mao, Xinguo; Zhang, Hongying; Tian, Shanjun; Chang, Xiaoping; Jing, Ruilian

    2010-01-01

    Osmotic stresses such as drought, salinity, and cold are major environmental factors that limit agricultural productivity worldwide. Protein phosphorylation/dephosphorylation are major signalling events induced by osmotic stress in higher plants. Sucrose non-fermenting 1-related protein kinase2 family members play essential roles in response to hyperosmotic stresses in Arabidopsis, rice, and maize. In this study, the function of TaSnRK2.4 in drought, salt, and freezing stresses in Arabidopsis was characterized. A translational fusion protein of TaSnRK2.4 with green fluorescent protein showed subcellular localization in the cell membrane, cytoplasm, and nucleus. To examine the role of TaSnRK2.4 under various environmental stresses, transgenic Arabidopsis plants overexpressing wheat TaSnRK2.4 under control of the cauliflower mosaic virus 35S promoter were generated. Overexpression of TaSnRK2.4 resulted in delayed seedling establishment, longer primary roots, and higher yield under normal growing conditions. Transgenic Arabidopsis overexpressing TaSnRK2.4 had enhanced tolerance to drought, salt, and freezing stresses, which were simultaneously supported by physiological results, including decreased rate of water loss, enhanced higher relative water content, strengthened cell membrane stability, improved photosynthesis potential, and significantly increased osmotic potential. The results show that TaSnRK2.4 is involved in the regulation of enhanced osmotic potential, growth, and development under both normal and stress conditions, and imply that TaSnRK2.4 is a multifunctional regulatory factor in Arabidopsis. Since the overexpression of TaSnRK2.4 can significantly strengthen tolerance to drought, salt, and freezing stresses and does not retard the growth of transgenic Arabidopsis plants under well-watered conditions, TaSnRK2.4 could be utilized in transgenic breeding to improve abiotic stresses in crops. PMID:20022921

  1. Aqueous atmospheric chemistry: formation of 2,4-dinitrophenol upon nitration of 2-nitrophenol and 4-nitrophenol in solution.

    PubMed

    Vione, Davide; Maurino, Valter; Minero, Claudio; Pelizzetti, Ezio

    2005-10-15

    Field studies have shown that the powerful phytotoxic agent 2,4-dinitrophenol is very likely to form in the atmospheric aqueous phase upon nitration of 2-nitrophenol or 4-nitrophenol. However, until now, the nitration pathway and the relative importance of the two mononitrophenols as sources of 2,4-dinitrophenol were not known. The present study shows that 2,4-dinitrophenol formation from mononitrophenols can take place upon photolysis and photooxidation of nitrite/nitrous acid (NO2-/HONO) and that nitrogen dioxide plays a key role in the process. A possible pathway might be the reaction between light-excited mononitrophenols (both 2- and 4-isomers) and nitrogen dioxide, in the presence of oxygen. As an alternative, nitration might involve *NO3 + *NO2. Possible sources of nitrogen dioxide in the atmospheric aqueous phase are dissolution from the gas phase and oxidation of NO2-. In the latter case, however, it is necessary that NO2- oxidation is faster than the oxidation of mononitrophenols. This would happen, for instance, in the presence of hematite under irradiation. Radiation absorption and scattering by hematite would also inhibit the direct photolysis of nitrophenols. The formation rate and the yield of 2,4-dinitrophenol are slightly higher when starting from 2-nitrophenol than those from 4-nitrophenol, but they are compensated by the higher concentration of 4-nitrophenol in the atmospheric aqueous phase.

  2. Synthesis, antifungal activities and molecular docking studies of novel 2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl dithiocarbamates.

    PubMed

    Zou, Yan; Yu, Shichong; Li, Renwu; Zhao, Qingjie; Li, Xiang; Wu, Maocheng; Huang, Ting; Chai, Xiaoxun; Hu, Honggang; Wu, Qiuye

    2014-03-01

    A series of 2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl dithiocarbamates as new analogs of fluconazole were synthesized and their antifungal activities were evaluated. Among these compounds, 2a-f and 3a-q exhibited higher activities than fluconazole against nearly all fungi tested except Aspergillus fumigatus. Noticeably, the in vitro biological activities of 2b, 3a, 3c, 3h-k, and 3o-q against Candida species were much better than those of fluconazole and ketoconazole. Also, 2a-d, 3a-d, 3e-f, 3h-k, 3p and 3q showed higher activities against A. fumi than fluconazole. Computational docking experiments indicated that the inhibition of CYP51 involved a coordination bond with iron of the heme group, the hydrophilic H-bonding region, the hydrophobic region, and the narrow hydrophobic cleft. PMID:24487187

  3. AN ENZYME LINKED IMMUNOSORBENT ASSAY (ELISA) METHOD FOR THE URINARY BIOMONITORING OF 2,4-DICHLOROPHRENOCYACETIC ACID (2,4-D)

    EPA Science Inventory

    An enzyme-linked immunosorbent assay (ELISA) method was developed to quantitatively measure 2,4-dichlorophenoyacetic acid (2,4-D) in human urine. Samples were diluted (1:5) with phosphate-buffered saline, 0.05% Tween 20, with 0.02% sodium azide, and analyzed by a 96-microwekk pl...

  4. Effects of prenatal exposure to 2,4-D/2,4,5-T mixture on postnatal changes in rat brain glutamate, GABA protein, and nucleic acid levels

    SciTech Connect

    Mohammad, F.K.; Omer, V.E.V.

    1988-02-01

    The opportunity of maternal exposure to various chemicals in the work place and the general environments have increased, and the fetus and neonate may be at greater risk than the adult. However, the embryotoxic and teratogenic effects of the chlorinated phenoxy herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), the main chemicals in Agent Orange, are well documented only in laboratory animals. The brain of the developing fetus is vulnerable to the toxic effects of the phenoxy herbicides which readily cross the placental barrier and distribute into fetal tissues, including brain. Although the neurochemical basis for the behavioral teratogenicity of the phenoxy herbicides is not know, it was recently reported that non-teratogenic doses of a 1:1 mixture of 2,4-D and 2,4,5-T delayed the ontogeny of dopamine and serotonin in the brain of the developing rate. This communication provides further descriptive information about the ontogeny of rat brain nucleic acid, protein, glutamate and ..gamma..-aminobutyrate (GABA) following in utero exposure to non-teratogenic levels of a 1:1 mixture of 2,4-D/2,4,5-T.

  5. Photo-Fenton degradation of phenol, 2,4-dichlorophenoxyacetic acid and 2,4-dichlorophenol mixture in saline solution using a falling-film solar reactor.

    PubMed

    Luna, Airton J; Nascimento, Cláudio A O; Foletto, Edson Luiz; Moraes, José E F; Chiavone-Filhoe, Osvaldo

    2014-01-01

    In this work, a saline aqueous solution of phenol, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenol (2,4-DCP) was treated by the photo-Fenton process in a falling-film solar reactor. The influence of the parameters such as initial pH (5-7), initial concentration of Fe2+ (1-2.5mM) and rate of H202 addition (1.87-3.74mmol min-1) was investigated. The efficiency of photodegradation was determined from the removal of dissolved organic carbon (DOC), described by the species degradation of phenol, 2,4-D and 2,4-DCP. Response surface methodology was employed to assess the effects of the variables investigated, i.e. [Fe2+], [H202] and pH, in the photo-Fenton process with solar irradiation. The results reveal that the variables' initial concentration of Fe2+ and H202 presents predominant effect on pollutants' degradation in terms of DOC removal, while pH showed no influence. Under the most adequate experimental conditions, about 85% DOC removal was obtained in 180 min by using a reaction system employed here, and total removal of phenol, 2,4- and 2,4-DCP mixture in about 30min.

  6. Effect of 2,4-Dichlorophenoxyacetic Acid (2,4-D) on PCDD/F Emissions from Open Burning of Biomass

    EPA Science Inventory

    Use of pesticides prior to agricultural burning and overspray onto forests and grasslands prior to fires has been cited as a cause of halogenated organic compound emissions from biomass combustion. Some pesticides such as 2,4-dichlorophenoxyacetic acid (2,4-D) are used in conside...

  7. Construction, expression, and characterization of a single-chain variable fragment antibody against 2,4-dichlorophenoxyacetic acid in the hemolymph of silkworm larvae.

    PubMed

    Sakamoto, Seiichi; Pongkitwitoon, Benyakan; Nakamura, Seiko; Sasaki-Tabata, Kaori; Tanizaki, Yusuke; Maenaka, Katsumi; Tanaka, Hiroyuki; Morimoto, Satoshi

    2011-07-01

    A single-chain variable fragment antibody against herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D-scFv) has been successfully expressed in the hemolymph of silkworm larvae using a rapid Bombyx mori nucleopolyhedrovirus (BmNPV) bacmid DNA system. Variable heavy- and light-chain domains were cloned directly from the cDNA of the hybridoma cell line 2C4 and assembled together with flexible peptide linker (Gly(4)Ser)(3) between two domains. The yield of functional 2,4-D-scFv after purification was 640 μg per 30 ml of hemolymph, which is equivalent to 21.3 mg per liter of hemolymph. The characterization of 2,4-D-scFv using an indirect competitive enzyme-linked immunosorbent assay (icELISA) revealed that it has wide cross-reactivities against 2,4,5-trichlorophenoxyacetic acid (65.5%), 2,4-dichlorophenol (47.9%), and 2,4-dichlorobenzoic acid (26.0%), making it possible to apply 2,4-D-scFv to icELISA for detecting/determining 2,4-D and its metabolites. Judging from its cost and time requirements and its ease of handling, this BmNPV bacmid DNA expression system is more useful for expressing functional scFv than bacterial systems, which frequently require costly and time-consuming refolding.

  8. 2,4-D and IAA Amino Acid Conjugates Show Distinct Metabolism in Arabidopsis

    PubMed Central

    Eyer, Luděk; Vain, Thomas; Pařízková, Barbora; Oklestkova, Jana; Barbez, Elke; Kozubíková, Hana; Pospíšil, Tomáš; Wierzbicka, Roksana; Kleine-Vehn, Jürgen; Fránek, Milan; Strnad, Miroslav; Robert, Stéphanie

    2016-01-01

    The herbicide 2,4-D exhibits an auxinic activity and therefore can be used as a synthetic and traceable analog to study auxin-related responses. Here we identified that not only exogenous 2,4-D but also its amide-linked metabolite 2,4-D-Glu displayed an inhibitory effect on plant growth via the TIR1/AFB auxin-mediated signaling pathway. To further investigate 2,4-D metabolite conversion, identity and activity, we have developed a novel purification procedure based on the combination of ion exchange and immuno-specific sorbents combined with a sensitive liquid chromatography-mass spectrometry method. In 2,4-D treated samples, 2,4-D-Glu and 2,4-D-Asp were detected at 100-fold lower concentrations compared to 2,4-D levels, showing that 2,4-D can be metabolized in the plant. Moreover, 2,4-D-Asp and 2,4-D-Glu were identified as reversible forms of 2,4-D homeostasis that can be converted to free 2,4-D. This work paves the way to new studies of auxin action in plant development. PMID:27434212

  9. 2,4-Dichlorophenoxyacetic acid metabolism in transgenic tolerant cotton (Gossypium hirsutum).

    PubMed

    Laurent, F; Debrauwer, L; Rathahao, E; Scalla, R

    2000-11-01

    The metabolic fate of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in leaves of transgenic 2,4-D-tolerant cotton (Gossypium hirsutum), which is obtained by transfer of the tfdA gene from the bacterium Alcaligenes eutrophus. The tdfA gene codes for a dioxygenase catalyzing the degradation of 2,4-D to 2, 4-dichlorophenol (2,4-DCP). [phenyl-(14)C]-2,4-D was administered by petiolar absorption followed by an 18 h water chase or converted to the isopropyl ester and sprayed onto the leaf surface; the leaves were harvested 48 h later. The herbicide was degraded to 2,4-DCP by the bacterial enzyme expressed in the plants. 2,4-DCP was rapidly converted to more polar metabolites and was never found in detectable amounts. Metabolite structures were deduced from enzymatic hydrolysis studies and mass spectrometric analyses. The first metabolite was the glucoside conjugate of 2,4-DCP (2, 4-DCP-beta-O-glucoside). The major terminal metabolites were two more complex glucosides: 2,4-DCP-(6-O-malonyl)glucoside and 2, 4-DCP-(6-O-sulfate)glucoside.

  10. 2,4-D and IAA Amino Acid Conjugates Show Distinct Metabolism in Arabidopsis.

    PubMed

    Eyer, Luděk; Vain, Thomas; Pařízková, Barbora; Oklestkova, Jana; Barbez, Elke; Kozubíková, Hana; Pospíšil, Tomáš; Wierzbicka, Roksana; Kleine-Vehn, Jürgen; Fránek, Milan; Strnad, Miroslav; Robert, Stéphanie; Novak, Ondrej

    2016-01-01

    The herbicide 2,4-D exhibits an auxinic activity and therefore can be used as a synthetic and traceable analog to study auxin-related responses. Here we identified that not only exogenous 2,4-D but also its amide-linked metabolite 2,4-D-Glu displayed an inhibitory effect on plant growth via the TIR1/AFB auxin-mediated signaling pathway. To further investigate 2,4-D metabolite conversion, identity and activity, we have developed a novel purification procedure based on the combination of ion exchange and immuno-specific sorbents combined with a sensitive liquid chromatography-mass spectrometry method. In 2,4-D treated samples, 2,4-D-Glu and 2,4-D-Asp were detected at 100-fold lower concentrations compared to 2,4-D levels, showing that 2,4-D can be metabolized in the plant. Moreover, 2,4-D-Asp and 2,4-D-Glu were identified as reversible forms of 2,4-D homeostasis that can be converted to free 2,4-D. This work paves the way to new studies of auxin action in plant development. PMID:27434212

  11. BIOTRANSFORMATION OF 2,4,6-TRINITROTOLUENE IN A CONTINUOUS-FLOW ANABAENA SP. SYSTEM. (R825513C013)

    EPA Science Inventory

    Reductive transformation of 2,4,6-trinitrotoluene (TNT) was observed in a continuous-flow system of Anabaena sp. operated for 33 d with a 5.7 d hydraulic retention time and a range of influent TNT concentrations of 1–58 mg/l. The TNT removal effici...

  12. Biodegradation of IMX-101 explosive formulation constituents: 2,4-dinitroanisole (DNAN), 3-nitro-1,2,4-triazol-5-one (NTO), and nitroguanidine.

    PubMed

    Richard, Thomas; Weidhaas, Jennifer

    2014-09-15

    Defense agencies are increasingly using insensitive munitions (IM) in place of explosives such as 2,4,6-trinitrotoluene. In this study simultaneous aerobic degradation of the IMX-101 formulation constituents 2,4-dinitroanisole (DNAN), 3-nitro-1,2,4-triazol-5-one (NTO), and nitroguanidine (NQ) was observed and degradation products were examined. Degradation products over four days of incubation included: nitrourea, 1,2-dihydro-3H-1,2,4-triazol-3-one, and 2,4-dinitrophenol. The enrichment culture maximum specific growth rate of 0.12h(-1) and half saturation constant of 288 mg L(-1) during degradation of IMX-101 as a sole nitrogen source suggest that enrichment culture growth kinetics may closely relate to those of other explosive and nitroaromatic compounds.

  13. Internationalization of Chinese Higher Education

    ERIC Educational Resources Information Center

    Chen, Linhan; Huang, Danyan

    2013-01-01

    This paper probes into the development of internationalization of higher education in China from ancient times to modern times, including the emergence of international connections in Chinese higher education and the subsequent development of such connections, the further development of internationalization of Chinese higher education, and the…

  14. Study on 3D surfactant assisted electrokinetic remediation of 1,2,4-trichlorobenzene in low permeability soil

    NASA Astrophysics Data System (ADS)

    Qiao, W.; Ye, S.; Wu, J.

    2014-12-01

    Electrickinetic(EK) is a promising remediation technology because of its capability to remediate soils with low permeability. It has been used for heavy metals and organic pollutant(OPs) contaminated soils. As the most OPs are poor solubility and strong sorption capacity, combined EK technology is usually used, for example, EK combined with surfactants. Numerous combined EK tests are done in one-dimension(1D) column, however, it is proved that there is a big gap between 1D tests and field application. The objectives of this study are to investigate the remediation efficiency and EK behavior of 1,2,4-trichlorobenzene(1,2,4-TCB) contaminated clay enhanced by surfactants in a three-dimension reactor with 28cm length×15cm width×16cm height. 1,2,4-TCB was one of the main contaminants at a field site in Nanjing, China, where the polluted soils are clay. Soil filled in EK cell was divided into six layers in depth, and each layer was divided into six parts in length and three parts in width. There were 108 specimens in total which realized 3D monitoring the effects of EK. Triton X-100(Exp1) and Tween80(Exp2) dissolved in NaCO3/NaHCO3 buffer respectively, were used as the anode purging solution. The distributions of soil pH and water content showed that the buffer was sufficient to neutralize H+ produced at anode and the direction of electroosmotic flow(EOF) remained constant. Exp2 generated a higher EOF than Exp1, but remediation efficiencies were not satisfactory so far. The concentration of 1,2,4-TCB in soil reached a peak and nadir in the normalized distances of 0.75 and 0.9 from cathode after 5 days, respectively. The 1,2,4-TCB concentration in the peak was almost twice as much as the initial concentration. It suggested that 1,2,4-TCB was desorbed from soil by surfactants and was transported from anode to cathode by EOF, which proved the capability of EK with surfactants to move 1,2,4-TCB in clay. The concentration of 1,2,4-TCB in the normalized distances of 0

  15. Kdo-(2 --> 8)-Kdo-(2 --> 4)-Kdo but not Kdo-(2 --> 4)-Kdo-(2 --> 4)-Kdo is an acceptor for transfer of L-glycero-alpha-D-manno-heptose by Escherichia coli heptosyltransferase I (WaaC).

    PubMed

    Gronow, Sabine; Lindner, Buko; Brade, Helmut; Müller-Loennies, Sven

    2009-02-01

    Early steps in the biosynthesis of lipopolysaccharide (LPS) involve the transfer of 3-deoxy-alpha-D-manno-oct-2-ulopyranosonic acid (Kdo) to lipid A. Whereas Kdo transferases (WaaA) of Escherichia coli generate a (2 --> 4)-linked Kdo disaccharide, Chlamydiae contain tri- or tetra-functional WaaA generating oligosaccharides with (2 --> 8)- and (2 --> 4)-linkages between Kdo. It has been suggested that the transfer of L-glycero-alpha-D-manno-heptose (Hep) to Kdo by an E. coli WaaC may not be possible in the presence of (2 --> 8)-linked Kdo. E. coli double-mutants deficient in heptosyltransferases I (waaC) and II (waaF) and expressing waaA of Chlamydiae instead of their own, make Chlamydia-type Kdo oligosaccharides which are attached to an E. coli lipid A. Using such strains expressing waaA of Chlamydophila pneumoniae, Chlamydophila psittaci, or Chlamydia trachomatis, we have studied the effect of E. coli waaC gene expression on LPS structure. Structural analyses revealed the formation of two novel oligosaccharides Hep-(1 --> 5)[Kdo-(2 --> 4)]-Kdo and Hep-(1 --> 5)[Kdo-(2 --> 8)-Kdo-(2 --> 4)]-Kdo showing that Hep is transferred in the presence of (2 --> 8)-linked Kdo. Surprisingly, the transfer of Hep onto Kdo-(2 --> 4)-Kdo-(2 --> 4)-Kdo did not occur, despite the fact that Hep-(1 --> 5)[Kdo-(2 --> 4)-Kdo-(2 --> 4)]-Kdo is found in nature as a partial structure of E. coli LPS. The premature end of the biosynthesis and incorporation of Hep into the LPS indicated that WaaC had access to the substrate before Kdo transfer was completed. We have observed differences between WaaA of C. trachomatis, C. pneumoniae and C. psittaci which indicate mechanistic differences between these Kdo transferases.

  16. New 1,2,4-triazole-based azo-azomethine dyes. Part I: Synthesis, characterization and spectroscopic studies

    NASA Astrophysics Data System (ADS)

    Khanmohammadi, Hamid; Erfantalab, Malihe

    2012-02-01

    Four new 1,2,4-triazole-based azo-azomethine dyes were synthesized via condensation of 3,5-diamino-1,2,4-triazole with azo-coupled o-vanillin precursors. The prepared dyes were characterized by IR, UV-vis and 1H NMR spectroscopic methods as well as elemental analyses. Thermal properties of the prepared dyes were examined by thermogravimetric analysis. Results indicated that the framework of the dyes was stable up to 225 °C. Also, the influence of various factors including time and mixed DMSO/EtOH solution on UV-vis spectra of the dyes were investigated.

  17. 41 CFR 301-2.4 - For what travel expenses am I responsible?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false For what travel expenses am I responsible? 301-2.4 Section 301-2.4 Public Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL ALLOWANCES INTRODUCTION 2-GENERAL RULES § 301-2.4 For...

  18. 10 CFR 960.3-2-2-4 - The environmental assessment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false The environmental assessment. 960.3-2-2-4 Section 960.3-2-2-4 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-4 The environmental...

  19. A SIMPLE ASSAY FOR 2,4-DICHLOROPHENOXYACETIC ACID USING COATED TEST-STRIPS

    EPA Science Inventory

    Immunoassay test strips utilizing ascending chromatography has been devised for the detection of 2.4-dichlorophenoxyacetic acid (2,4-D). This test requires no instrumentation, inexpensive reagents and relies on the application of antibodies to 2,4-D adsorbed onto colloidal gol...

  20. ELECTROCHEMICALLY DEPOSITED POLYMER-COATED GOLD ELECTRODES SELECTIVE FOR 2,4-DICHLOROPHENOXYACETIC ACID

    EPA Science Inventory

    Electropolymerized membranes on gold electrodes doped with 2,4-dichlorophenoxyacetic acid (2,4-D) were prepared from a solution containing resorcinol, o-phenylenediamine and 2,4-D. Fourier Transform Infrared (FTIR) spectroscopy was used to evaluate the incorporation and interact...

  1. Liver Toxicity of Munition Compounds 2,4-and 2,6- and Technical Grade Dinitrotoluene

    EPA Science Inventory

    Munitions compounds 2,4-dinitrotoluene (2,4-DNT) and 2,6-dinitrotoluene (2,6-DNT) are the two most common of the six isomers of dinitrotoluene (DNT). Technical grade dinitrotoluene (tgDNT) is a mixture of the six DNT isomers and is comprised of 76% 2,4-DNT and 19% 2,6-DNT with t...

  2. 10 CFR 960.3-2-2-4 - The environmental assessment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false The environmental assessment. 960.3-2-2-4 Section 960.3-2-2-4 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-4 The environmental...

  3. 10 CFR 960.3-2-2-4 - The environmental assessment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false The environmental assessment. 960.3-2-2-4 Section 960.3-2-2-4 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-4 The environmental...

  4. 10 CFR 960.3-2-2-4 - The environmental assessment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false The environmental assessment. 960.3-2-2-4 Section 960.3-2-2-4 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-4 The environmental...

  5. 10 CFR 960.3-2-2-4 - The environmental assessment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false The environmental assessment. 960.3-2-2-4 Section 960.3-2-2-4 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-4 The environmental...

  6. 41 CFR 301-2.4 - For what travel expenses am I responsible?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 4 2011-07-01 2011-07-01 false For what travel expenses am I responsible? 301-2.4 Section 301-2.4 Public Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL ALLOWANCES INTRODUCTION 2-GENERAL RULES § 301-2.4 For...

  7. 9 CFR 2.4 - Non-interference with APHIS officials.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Non-interference with APHIS officials. 2.4 Section 2.4 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Licensing § 2.4 Non-interference with APHIS officials....

  8. 9 CFR 2.4 - Non-interference with APHIS officials.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Non-interference with APHIS officials. 2.4 Section 2.4 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Licensing § 2.4 Non-interference with APHIS officials....

  9. 9 CFR 2.4 - Non-interference with APHIS officials.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Non-interference with APHIS officials. 2.4 Section 2.4 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Licensing § 2.4 Non-interference with APHIS officials....

  10. 9 CFR 2.4 - Non-interference with APHIS officials.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Non-interference with APHIS officials. 2.4 Section 2.4 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Licensing § 2.4 Non-interference with APHIS officials....

  11. 9 CFR 2.4 - Non-interference with APHIS officials.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Non-interference with APHIS officials. 2.4 Section 2.4 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Licensing § 2.4 Non-interference with APHIS officials....

  12. 40 CFR 721.10117 - Heteromonocyclo-beta-(2,4-dichlorophenyl) -1-propanol (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Heteromonocyclo-beta-(2,4... Significant New Uses for Specific Chemical Substances § 721.10117 Heteromonocyclo-beta-(2,4-dichlorophenyl) -1... substance identified generically as heteromonocyclo-beta-(2,4-dichlorophenyl) -1-propanol (PMN P-04-776)...

  13. 40 CFR 721.10117 - Heteromonocyclo-beta-(2,4-dichlorophenyl) -1-propanol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Heteromonocyclo-beta-(2,4... Significant New Uses for Specific Chemical Substances § 721.10117 Heteromonocyclo-beta-(2,4-dichlorophenyl) -1... substance identified generically as heteromonocyclo-beta-(2,4-dichlorophenyl) -1-propanol (PMN P-04-776)...

  14. Toxicological responses of red-backed salamanders (Plethodon cinereus) to subchronic soil exposures of 2,4-dinitrotoluene.

    PubMed

    Johnson, Mark S; Suski, Jamie; Bazar, Matthew A

    2007-06-01

    Dinitrotoluenes are used as propellants and in explosives by the military and as such have been found at relatively high concentrations in the soil. To determine whether concentrations of 2,4-dinitrotoluene (2,4-DNT) in soil are toxic to amphibians, 100 red-backed salamanders (Plethodon cinereus) were exposed to either 1500, 800, 200, 75 or 0mg 2,4-DNT/kg soil for 28 days and evaluated for indicators of toxicity. Concentrations of 2,4-DNT were less than targets and varied with time. Most salamanders exposed to concentrations exceeding 1050 mg/kg died or were moribund within the first week. Salamanders exposed to soil concentrations exceeding 345 mg/kg lost >6% of their body mass though no mortality occurred. Overt effects included a reduction in feed consumption and an increase in bucco-pharyngeal oscillations in salamanders. These results suggest that only high soil concentrations of 2,4-DNT have the potential to cause overtly toxic effects in terrestrial salamanders.

  15. Relationship between the 2.4-km run and multistage shuttle run test performance in military personnel.

    PubMed

    Wilkinson, David M; Blacker, Sam D; Richmond, Victoria L; Rayson, Mark P; Bilzon, James L J

    2014-02-01

    In the United Kingdom, all branches of the armed forces use 2.4-km run time and/or the 20-m multistage shuttle run test (MSRT) to assess the aerobic fitness of their personnel. This study quantified the relationship between these two tests in 156 army recruits and officer cadets (100 men and 56 women) to ensure equivalence in the required aerobic fitness standards. The 2.4-km run was performed on surfaced roads and tracks around the training establishment and the MSRT in a gymnasium. Ordinary least product regression was used to describe the relationship between average 2.4-km running speed (km · h(-1)) and the total number of shuttles completed on the U.K. version of the MSRT (r = 0.91, p < 0.01), showing MSRT shuttles = (9.708×2.4-km run speed) - 52.56, with a standard error of prediction of approximately 8 shuttles or 0.8 km · h(-1). The British Army 2.4-km run biannual fitness assessment standard for young men of 10:30 min:s equates to a MSRT score of 82 shuttles (level 10 and 1 shuttle) and for young women of 13:00 min:s equates to 56 shuttles (level 7 and 6 shuttles), with a standard error of estimate of approximately 8 shuttles. PMID:24491618

  16. Adsorption and photodegradation kinetics of herbicide 2,4,5-trichlorophenoxyacetic acid with MgFeTi layered double hydroxides.

    PubMed

    Nguyen, Thi Kim Phuong; Beak, Min-wook; Huy, Bui The; Lee, Yong-Ill

    2016-03-01

    The calcined layered double hydroxides (cLDHs) Ti-doped and undoped MgFe for this study were prepared by co-precipitation method followed by calcination at 500 °C. The as-prepared samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer Emmett Teller (BET) and UV-Vis diffuse reflectance spectrum (DRS) techniques and tested for adsorption and photodegradation (including photocatalytic and photo-Fenton-like) of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in aqueous solutions under visible light irradiation. In the range of studied operating conditions, the as-prepared samples exhibited excellent photo-Fenton-like activity, leading to more than 80-95% degradation of 2,4,5-T at initial concentration of 100 mg L(-1) with 4 g calcined LDHs per liter, was accomplished in 360 min, while 2,4,5-T half-life time was as short as 99-182 min. The kinetics of adsorption and photodegradation of 2,4,5-T were also discussed. These results offered a green, low cost and high efficiency photocatalyst for environmental remediation.

  17. Rapid adsorption of 2,4-dichlorophenoxyacetic acid by iron oxide nanoparticles-doped carboxylic ordered mesoporous carbon.

    PubMed

    Tang, Lin; Zhang, Sheng; Zeng, Guang-Ming; Zhang, Yi; Yang, Gui-De; Chen, Jun; Wang, Jing-Jing; Wang, Jia-Jia; Zhou, Yao-Yu; Deng, Yao-Cheng

    2015-05-01

    The ordered mesoporous carbon composite functionalized with carboxylate groups and iron oxide nanoparticles (Fe/OMC) was successfully prepared and used to adsorb 2,4-dichlorophenoxyacetic acid (2,4-D) from wastewater. The resultant adsorbent possessed high degree of order, large specific surface area and pore volume, and good magnetic properties. The increase in initial pollutant concentration and contact time would make the adsorption capacity increase, but the pH and temperature are inversely proportional to 2,4-D uptake. The equilibrium of adsorption was reached within 120 min, and the equilibrated adsorption capacity increased from 99.38 to 310.78 mg/g with the increase of initial concentration of 2,4-D from 100 to 500 mg/L. Notablely, the adsorption capacity reached 97% of the maximum within the first 5 min. The kinetics and isotherm study showed that the pseudo-second-order kinetic and Langmuir isotherm models could well fit the adsorption data. These results indicate that Fe/OMC has a good potential for the rapid adsorption of 2,4-D and prevention of its further diffusion.

  18. 2,4-Dichlorophenoxyacetic acid (2,4-D) degradation promoted by nanoparticulate zerovalent iron (nZVI) in aerobic suspensions.

    PubMed

    Correia de Velosa, Adriana; Pupo Nogueira, Raquel F

    2013-05-30

    Reactive species generated by Fe(0) oxidation promoted by O2 (catalyzed or not by ligands) are able to degrade contaminant compounds like the herbicide 2,4-dichlorophenoxyacetic acid. The degradation of 2,4-D was influenced by the concentrations of zero valent iron (ZVI) and different ligands, as well as by pH. In the absence of ligands, the highest 2,4-D degradation rate was obtained at pH 3, while the highest percentage degradation (50%) was achieved at pH 5 after 120 min of reaction. Among the ligands studied (DTPA, EDTA, glycine, oxalate, and citrate), only ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) significantly enhanced oxidation of 2,4-D. This increase in oxidation was observed at all pH values tested (including neutral to alkaline conditions), indicating the feasibility of the technique for treatment of contaminated water. In the presence of EDTA, the oxidation rate was greater at pH 3 than at pH 5 or 7. Increasing the EDTA concentration increased the rate and percentage of 2,4-D degradation, however increasing the Fe(0) concentration resulted in the opposite behavior. It was found that degradation of EDTA and 2,4-D occurred simultaneously, and that the new methodology avoided any 2,4-D removal by adsorption/coprecipitation.

  19. Moisturizing lotions can increase transdermal absorption of the herbicide 2,4-dichlorophenoxacetic acid across hairless mouse skin.

    PubMed

    Brand, R M; Charron, A R; Sandler, V L; Jendrzejewski, J L

    2007-01-01

    Moisturizing lotions can be an effective treatment for occupationally induced dry skin. These compounds are designed to be hygroscopic and retain water to keep the stratum corneum hydrated, while at the same time enhancing the horny layer to prevent increases in transepidermal water loss (TEWL). Skin hydration levels, however, are known to influence barrier properties. The purpose of this work was to compare skin moisture levels induced by four commercially available moisturizing lotions with their capacity as transdermal penetration enhancers using the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) as a model chemical. Further, the effect of moisturizing the skin after washing with sodium lauryl sulfate (SLS) on transdermal absorption was determined. Skin moisture levels were also measured noninvasively and were correlated to penetration enhancement. Hairless mouse skin was pretreated with commercially available moisturizing lotions either with or without SLS washing and in vitro permeability studies were performed with the herbicide 2,4-D. The data demonstrate that pretreatment with three of the four lotions tested increased the transdermal absorption of 2,4-D as evidenced by cumulative penetration or faster lag times (p < 0.05). Skin moisture levels correlated with the penetration enhancement capabilities of the lotion. Washing the skin with 5% SDS increased the transdermal absorption of 2,4-D (p < 0.05) and application of moisturizing lotions increased the absorption further. In summary moisturizing lotions may influence transdermal penetration of the skin, with the more effective moisturizers having a greater effect on 2,4-D absorption.

  20. Women in Higher Education.

    ERIC Educational Resources Information Center

    Pifer, Alan

    Women have traditionally been discriminated against in higher education in both the attainment of degrees and in employment after earning degrees. It has been felt that women are not as capable, reliable, or effective as men in administrative and classroom situations. Statistics show that even at the present time women are underemployed and…