Science.gov

Sample records for 4-6 times higher

  1. 15 CFR 4.6 - Time limits and expedited processing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...; (ii) The loss of substantial due process rights; (iii) A matter of widespread and exceptional media interest involving questions about the Government's integrity which affect public confidence; or (iv) An...)(iv) of this section, if not a full-time member of the news media, must establish that he or she is...

  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. 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…

  5. 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;…

  6. 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 ...

  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. 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…

  9. 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

  10. 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

  11. 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…

  12. 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…

  13. 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…

  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. 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…

  16. 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…

  17. Real-Time N2O Gas Detection System for Agricultural Production Using a 4.6-μm-Band Laser Source Based on a Periodically Poled LiNbO3 Ridge Waveguide

    PubMed Central

    Tokura, Akio; Asobe, Masaki; Enbutsu, Koji; Yoshihara, Toshihiro; Hashida, Shin-nosuke; Takenouchi, Hirokazu

    2013-01-01

    This article describes a gas monitoring system for detecting nitrous oxide (N2O) gas using a compact mid-infrared laser source based on difference-frequency generation in a quasi-phase-matched LiNbO3 waveguide. We obtained a stable output power of 0.62 mW from a 4.6-μm-band continuous-wave laser source operating at room temperature. This laser source enabled us to detect atmospheric N2O gas at a concentration as low as 35 parts per billion. Using this laser source, we constructed a new real-time in-situ monitoring system for detecting N2O gas emitted from potted plants. A few weeks of monitoring with the developed detection system revealed a strong relationship between nitrogen fertilization and N2O emission. This system is promising for the in-situ long-term monitoring of N2O in agricultural production, and it is also applicable to the detection of other greenhouse gases. PMID:23921829

  18. 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…

  19. 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…

  20. 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.

  1. 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.

  2. 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.

  3. 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…

  4. 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.

  5. 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

  6. 2,3,4,6-Tetrachlorophenol

    Integrated Risk Information System (IRIS)

    2,3,4,6 - Tetrachlorophenol ; CASRN 58 - 90 - 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 Noncar

  7. A Dogrib History. Grade 4-6.

    ERIC Educational Resources Information Center

    Fraser, Tara

    A publication on the history and traditional lifestyle of the Dogrib Tribe of Canada's Northwest Territories is intended for use in grades 4-6. The text is illustrated with numerous drawings. Sections describe the caribou, spruce tree, muskox, fox, ducks and geese and their usefulness to Dogrib people. Activities covered are trading at the trading…

  8. Career Education: Grades 4-6.

    ERIC Educational Resources Information Center

    Cortland-Madison Board of Cooperative Educational Services, Cortland, NY.

    The third of a series of nine career education guides includes four social studies units for grades 4-6. Part one, famous Americans from Plymouth Rock to Tranquility Base, includes goals, objectives, skills to be taught or reviewed, lists of famous Americans in the fields of science and medicine, inventions, sports, religion, politics, literature,…

  9. 4-6 Computer Awareness. Interim Guide.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education, Winnipeg. Computer Services Branch.

    This guide was developed to assist teachers in achieving goals related to the development of computer awareness in students in grades 4-6 in the Canadian province of Manitoba. An overview of the program describes a set of basic concepts, skills, and attitudes relating to computer technology, and provides information on activities that can be used…

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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,"…

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. 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.

  4. Time-resolved in situ detection of CO in a shock tube using cavity-enhanced absorption spectroscopy with a quantum-cascade laser near 4.6 µm.

    PubMed

    Sun, Kai; Wang, Shengkai; Sur, Ritobrata; Chao, Xing; Jeffries, Jay B; Hanson, Ronald K

    2014-10-01

    Cavity-enhanced absorption spectroscopy (CEAS) using a mid-infrared DFB quantum-cascade laser is reported for sensitive time-resolved (10 μs) in situ CO measurements in a shock tube. Off-axis alignment and fast scanning of the laser wavelength were used to minimize coupling noise in a low-finesse cavity. An absorption gain factor of 91 was demonstrated, which enabled sub-ppm detection sensitivity for gas temperatures of 1000-2100K in a 15 cm diameter shock tube. This substantial improvement in detection sensitivity compared to conventional single-pass absorption measurements, shows great potential for the study of reaction pathways of high-temperature combustion kinetics mechanisms in shock tubes.

  5. 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)

  6. Czochralski growth and Faraday rotation properties of Tb9.33(SiO4)6O2 crystals

    NASA Astrophysics Data System (ADS)

    Chen, Xin; Gong, Zhongliang; Fu, Hao; Zhuang, Naifeng; Zhang, Wenhui; Xie, Xitong; Guo, Feiyun; Chen, Jianzhong

    2015-05-01

    Tb9.33(SiO4)6O2 crystals have been grown by the Czochralski technique for the first time for magneto-optical applications. Rietveld structure refinement of XRD data confirms that the compound crystallizes in the hexagonal system P63 / m, with oxyapatite structure. Transmittance spectra and the Faraday rotation have been investigated, which demonstrate that Tb9.33(SiO4)6O2 crystals show a higher visible transparency and a larger Faraday rotation than Tb3Ga5O12 crystals. Tb9.33(SiO4)6O2 is therefore a promising material in particular for new magneto-optical applications in the visible-near IR wavelength region.

  7. 16 CFR 4.6 - Cooperation with other agencies.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Cooperation with other agencies. 4.6 Section 4.6 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE MISCELLANEOUS RULES § 4.6 Cooperation with other agencies. It is the policy of the Commission to cooperate...

  8. 37 CFR 4.6 - Attorneys and Agents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Attorneys and Agents. 4.6 Section 4.6 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL COMPLAINTS REGARDING INVENTION PROMOTERS § 4.6 Attorneys and Agents. Complaints...

  9. 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.

  10. 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

  11. 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.…

  12. 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…

  13. 11 CFR 4.6 - Discretionary release of exempt records.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... the public interest and that the rights of third parties would not be prejudiced. ... 11 Federal Elections 1 2010-01-01 2010-01-01 false Discretionary release of exempt records. 4.6 Section 4.6 Federal Elections FEDERAL ELECTION COMMISSION PUBLIC RECORDS AND THE FREEDOM OF...

  14. 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.

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  19. 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

  20. 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).

  1. 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.

  2. 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…

  3. 17 CFR 275.206(4)-6 - Proxy voting.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Proxy voting. 275.206(4)-6...) RULES AND REGULATIONS, INVESTMENT ADVISERS ACT OF 1940 § 275.206(4)-6 Proxy voting. If you are an... section 206(4) of the Act (15 U.S.C. 80b-6(4)), for you to exercise voting authority with respect...

  4. 17 CFR 275.206(4)-6 - Proxy voting.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Proxy voting. 275.206(4)-6...) RULES AND REGULATIONS, INVESTMENT ADVISERS ACT OF 1940 § 275.206(4)-6 Proxy voting. If you are an... section 206(4) of the Act (15 U.S.C. 80b-6(4)), for you to exercise voting authority with respect...

  5. A PI 4. 6 peroxidase that specifically crosslinks extensin precursors

    SciTech Connect

    Upham, B.L; Alizadeh, H.; Ryan, K.J.; Lamport, D.T.A. )

    1991-05-01

    The primary cell wall is a microcomposite of cellulose, pectin, hemicellulose and protein. The warp-weft model of the primary cell wall hypothesize that extensin monomers are intermolecularly crosslinked orthogonal to the cellulose microfibril thus mechanically coupling the major load-bearing polymer: cellulose. Media of tomato cell cultures contains heat labile, peroxide dependent crosslinking activity, as determined by the rate of decrease in monomer concentration analyzed via Superose-6. Isoelectric focusing of tomato cell culture media indicated crosslinking was predominantly in the acidic peroxidase fraction (pI4.6). This peroxidase was partially purified by ultracentrifugation, DEAE-Trisacryl and HPLC-DEAE chromatography techniques resulting in a 90 fold purification and 45% yield. A second acidic peroxidase eluted from the HPLC-DEAE column had 25% of the crosslinking activity of the pI 4.6 peroxidase. Purified basic peroxidase had only 0.7% of the activity of the pI 4.6 peroxidase. The specific activity of the pI 4.6 peroxidase was 5,473 mg extensin crosslinked/min/mg peroxidase. The pI 4.6 peroxidase crosslinked the following extensins: tomato I and II, carrot, Ginkgo II and did not crosslink Ginkgo I, Douglas Fir, Maize, Asparagus I and II, and sugarbeet extensins as well as bovine serum albumin. Comparison of motifs common to extensins that are crosslinked by the pI 4.6 peroxidase may help identify the crosslink domain(s) of extension.

  6. 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

  7. 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,…

  8. 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…

  9. 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…

  10. 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…

  11. Pseudomonas sp. CL7 from Sludge Removed 2,3,4,6-Tetrachlorophenol in Vivo and in Vitro Condition.

    PubMed

    Karn, Santosh Kumar; Reddy, M Sudhakara; Chakrabarti, Swapan Kumar

    2016-04-01

    The present research focused on 2,3,4,6-Tetrachlorophenol (2,3,4,6-TeCP) mineralizing bacterium from the sludge of pulp and paper industry and identified as Pseudomonas sp. CL7 by 16s rRNA gene sequences analysis. This isolate degraded 2,3,4,6-TeCP as indicated by stoichiometric release of chloride and biomass formation. High pressure liquid chromatography (HPLC) analysis showed that Pseudomonas sp. (CL7) was able to mineralize a higher concentration of 2,3,4,6-TeCP (600 mg/l or 2.5 mM) than any previously reported 2,3,4,6-TeCP degrading bacteria. As the concentration of 2,3,4,6-TeCP increased from 50 (0.21 mM) to 600 mg/l (2.5 mM), the reduction in the cell growth was observed and the 2,3,4,6-TeCP degradation was more than 85% in all the concentrations in the present study. CL7 was able to remove 100% of 2,3,4,6-TeCP from the sludge (in Vitro condition) when supplemented with 100 mg/l (0.42 mM) of 2,3,4,6-TeCP and grown for two weeks. This study showed that CL7 can be used for bioremediation of 2,3,4,6-TeCP. PMID:27131053

  12. Isolation, characterization, and systematic significance of 2-pyrone-4,6-dicarboxylic acid in Rosaceae.

    PubMed

    Wilkes, S; Glasl, H

    2001-10-01

    2-Pyrone-4,6-dicarboxylic acid was isolated from Potentilla anserina. Until now this substance was only found in bacteria and not in higher plants. By sterile cultivation it was verified that this compound is genuine also in plants. In addition the systematic relevance of 2-pyrone-4,6-dicarboxylic acid within the Rosaceae was tested. The compound seems to be a chemotaxonomic marker for the Rosoideae sensu stricto proposed by Morgan et al. (Morgan, D.R., Soltis, D.E., Robertson, K.R., 1994. Systematic and evolutionary implications of rbcL sequence variation in Rosaceae. American Journal of Botany 81, 890-903).

  13. 11. DETAILS: CONCRETE SHEET PILING, CORNERS #4 & #6, DWG. ...

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

    11. DETAILS: CONCRETE SHEET PILING, CORNERS #4 & #6, DWG. NO. 11, 1-1/2" = 1 FT., FEB. 12, 1908, MADE BY E.C.L., APPROVED BY O.F. LACKEY - Baltimore Inner Harbor, Pier 5, South of Pratt Street between Market Place & Concord Street, Baltimore, Independent City, MD

  14. Health Promotion Activity Book for Grades 4-6.

    ERIC Educational Resources Information Center

    Ohio State Dept. of Health, Columbus.

    This book of activities is designed to supplement health lessons for students in grades 4-6. Some of the activities are quite simple and require very little instruction and direction, while others are more difficult and require careful explanation prior to completion. The level of difficulty of the activities is varied in order to create both…

  15. 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...

  16. 41 CFR 60-4.6 - Goals and timetables.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., in the Notice required by 41 CFR 60-4.2. Covered construction contractors performing construction... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Goals and timetables. 60... 4-CONSTRUCTION CONTRACTORS-AFFIRMATIVE ACTION REQUIREMENTS § 60-4.6 Goals and timetables....

  17. 4,6-Dinitro-o-cyclohexyl phenol

    Integrated Risk Information System (IRIS)

    4,6 - Dinitro - o - cyclohexyl phenol ; CASRN 131 - 89 - 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

  18. 4.6 Doses to Patients in Therapy

    NASA Astrophysics Data System (ADS)

    Noßke, D.; Mattsson, S.; Johansson, L.

    This document is part of Subvolume A 'Fundamentals and Data in Radiobiology, Radiation Biophysics, Dosimetry and Medical Radiological Protection' of Volume 7 'Medical Radiological Physics' of Landolt-Börnstein - Group VIII 'Advanced Materials and Technologies'. It contains the Section '4.6 Doses to Patients in Therapy' of the Chapter '4 Dosimetry in Nuclear Medicine Diagnosis and Therapy' with the contents:

  19. Learn about Seabirds. Teaching Packet, Grades 4-6.

    ERIC Educational Resources Information Center

    Fish and Wildlife Service (Dept. of Interior), Anchorage, AK.

    This teaching packet is designed to teach Alaskan students in grades 4-6 about Alaska's seabird populations, the worldwide significance of seabirds, and the environmental conditions to which seabirds are sensitive. The packet includes a curriculum guide (containing a teacher's background story and 12 teaching activities), a separately published…

  20. Science 4-6. Kentucky's Environmental Education Program.

    ERIC Educational Resources Information Center

    Kentucky State Dept. of Education, Frankfort. Div. of Program Development.

    This unit of instruction for grades 4-6 is one of a series of curriculum units referred to as the Interdisciplinary Unit. Its purpose is to allow the individual teacher to expose the students to many experiences, ideas, and applications based on their environment (Kentucky). Each lesson is built on two basic concepts, each to balance the other.…

  1. Council Minutes, February 4-6, 2011: Santa Monica, California

    ERIC Educational Resources Information Center

    Educational Researcher, 2011

    2011-01-01

    This article presents minutes of the American Educational Research Association's meetings held in Santa Monica, California, on February 4-6, 2011. President Kris D. Gutierrez led a discussion of the meeting dates for the summer Executive Board and Council meetings. It was agreed that members of Council will be polled to determine the best dates…

  2. Creating Sacred Places for Children in Grades 4-6.

    ERIC Educational Resources Information Center

    Fox, Sandra J.

    This guide attempts to help teachers of American Indian children in grades 4-6 provide a culturally relevant education that takes place in the regular classroom, includes content related to Indian students' lives, makes students proud, expands to other experiences, and enhances learning. Creating sacred places means responding appropriately to…

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. Onset of spermatogenesis is accelerated by gestational administration of 1,2,3,4,6,7-hexachlorinated naphthalene in male rat offspring.

    PubMed Central

    Omura, M; Masuda, Y; Hirata, M; Tanaka, A; Makita, Y; Ogata, R; Inoue, N

    2000-01-01

    We treated pregnant rats with 1 microg/kg body weight/day 1,2,3,4,6,7-hexachlorinated naphthalene (1,2,3,4,6,7-HxCN) on days 14-16 of gestation and examined the effects on the reproductive systems of their male offspring at various phases of sexual maturation. Sperm count in the cauda epididymidis did not change in 1,2,3,4,6, 7-HxCN-treated rats on postnatal day 89, the age of sexual maturity, but the sperm count in the cauda epididymidis did increase to approximately 180% of the control value on postnatal day 62. In addition, homogenization-resistant testicular spermatids increased to approximately 160% of the control value on postnatal day 48, and the percent of postmeiotic tubules increased to approximately 190% of the control value on postnatal day 31 in this group. These results indicate that the onset of spermatogenesis was accelerated in the 1,2,3,4,6,7-HxCN rats. Serum concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) had already reached the maximum level on postnatal day 31 in the 1,2,3,4,6, 7-HxCN group, suggesting that the onset of LH and FSH secretions from the pituitary gland was also accelerated and that this endocrine disruption was the cause of early onset of spermatogenesis in this group. In the fat of 1,2,3,4,6,7-HxCN-treated dams, 5.75+/-2.81 ppb 1,2,3,4,6,7-HxCN was detected when offspring were weaned. This concentration was 5-10 times higher than that found in human adipose tissue. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:10856028

  8. 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.

  9. 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…

  10. "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…

  11. 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…

  12. 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

  13. 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…

  14. 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

  15. Antimony(III) complexes with 2-amino-4,6-dimethoxypyrimidines: Synthesis, characterization and biological evaluation.

    PubMed

    Tunç, Turgay; Karacan, Mehmet Sayım; Ertabaklar, Hatice; Sarı, Musa; Karacan, Nurcan; Büyükgüngör, Orhan

    2015-12-01

    Novel pyrimidine compound bearing disulfide bridge, 5,5'-disulfanediylbis(2-amino-4,6-dimetoxypyrimidine) (3) was synthesized by reduction of 2-amino-4,6-dimethoxy-5-thiocyanatopyrimidine for the first time, and its structure was confirmed by X-ray crystallographic analysis. Novel binuclear antimony(III) compound of (3), {Sb[5,5'-disulfanediylbis(2-amino-4,6-dimetoxypyrimidine)]Cl3}2 (4) and mononuclear antimony(III) compounds, SbL2Cl3, [L: 2-amino-5-thiol-4,6-dimethoxy pyrimidine (2) and 2-amino-5-(1H-tetrazol-5-ylthio)-4,6-dimethoxypyrimidine (6)] were synthesized and characterized with the help of elemental analysis, molecular conductivity, FT-IR, (1)H-NMR and LC-MS techniques. The geometrical structures optimized by a DFT/B3LYP/LANL2DZ method of the compounds, indicated that monomeric compounds have square pyramidal shape. Both antileishmanial activity against Leishmania tropica promastigote and glutathione reductase inhibitory activity were determined in vitro. The results showed that (3) has the best biological activity. PMID:26427018

  16. Antimony(III) complexes with 2-amino-4,6-dimethoxypyrimidines: Synthesis, characterization and biological evaluation.

    PubMed

    Tunç, Turgay; Karacan, Mehmet Sayım; Ertabaklar, Hatice; Sarı, Musa; Karacan, Nurcan; Büyükgüngör, Orhan

    2015-12-01

    Novel pyrimidine compound bearing disulfide bridge, 5,5'-disulfanediylbis(2-amino-4,6-dimetoxypyrimidine) (3) was synthesized by reduction of 2-amino-4,6-dimethoxy-5-thiocyanatopyrimidine for the first time, and its structure was confirmed by X-ray crystallographic analysis. Novel binuclear antimony(III) compound of (3), {Sb[5,5'-disulfanediylbis(2-amino-4,6-dimetoxypyrimidine)]Cl3}2 (4) and mononuclear antimony(III) compounds, SbL2Cl3, [L: 2-amino-5-thiol-4,6-dimethoxy pyrimidine (2) and 2-amino-5-(1H-tetrazol-5-ylthio)-4,6-dimethoxypyrimidine (6)] were synthesized and characterized with the help of elemental analysis, molecular conductivity, FT-IR, (1)H-NMR and LC-MS techniques. The geometrical structures optimized by a DFT/B3LYP/LANL2DZ method of the compounds, indicated that monomeric compounds have square pyramidal shape. Both antileishmanial activity against Leishmania tropica promastigote and glutathione reductase inhibitory activity were determined in vitro. The results showed that (3) has the best biological activity.

  17. Inositol 1,3,4,6-tetrakisphosphate mobilizes calcium in Xenopus oocytes with high potency.

    PubMed Central

    Ivorra, I; Gigg, R; Irvine, R F; Parker, I

    1991-01-01

    Injection of Ins(1,3,4,6)P4 into Xenopus oocytes evoked Ca2(+)-dependent membrane currents with a potency 5-10 times less than Ins(1,4,5)P3, whereas Ins(1,3,4)P3 and Ins(1,3,4,5,6)P5 were almost ineffective. Responses to Ins(1,3,4,6)P4 arose through liberation of intracellular Ca2+ and through entry of extracellular Ca2+. These results, together with the observation that Ins(1,3,4,6)P4 facilitated responses to Ins(1,4,5)P3, suggests that both of these compounds may act on the same intracellular receptors. PMID:1991032

  18. 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…

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  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. Czochralski growth of Sr2Tb8(SiO4)6O2 crystals for visible-near IR magneto-optical applications

    NASA Astrophysics Data System (ADS)

    Chen, Xin; Zhang, Wenhui; Wan, Qiping; Guo, Feiyun; Zhuang, Naifeng; Fu, Hao; Xie, Xitong; Chen, Jianzhong

    2014-11-01

    Sr2Tb8(SiO4)6O2 crystals have been grown and investigated for the first time for magneto-optical applications. The X-ray powder diffraction confirms that the compound crystallizes in the hexagonal system, with a common oxyapatite structure. The as-grown crystal exhibits low thermal expansion anisotropy (αa/αc ≈ 1.1), and the hardness is about 5.0 Moh. The temperature dependence of the magnetic susceptibility indicated that the Sr2Tb8(SiO4)6O2 crystal exhibits paramagnetic behavior over the experimental temperature-range 2-300 K. The present investigations demonstrate that Sr2Tb8(SiO4)6O2 crystals show a higher visible transparency and a larger Faraday rotation than terbium gallium garnet (TGG) crystals. Sr2Tb8(SiO4)6O2 is therefore a very promising material in particular for new magneto-optical applications in the visible-near IR wavelength region.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

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

    SciTech Connect

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

    2013-02-08

    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.

  2. 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

  3. 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

  4. 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;…

  5. 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.

  6. 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.

  7. 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.

  8. 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…

  9. 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…

  10. 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

  11. 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

  12. CDK4/6 Inhibitor PD0332991 in Glioblastoma Treatment: Does It Have a Future?

    PubMed Central

    Schröder, Lisette B. W.; McDonald, Kerrie L.

    2015-01-01

    Glioblastoma is aggressive, highly infiltrating, and the most frequent malignant form of brain cancer. With a median survival time of only 14.6 months, when treated with the standard of care, it is essential to find new therapeutic options. A specific CDK4/6 inhibitor, PD0332991, obtained accelerated approval from the Food and Drug Administration for the treatment of patients with advanced estrogen receptor-positive and HER2-negative breast cancer. Common alterations in the cyclin D1-cyclin-dependent kinase 4/6-retinoblastoma 1 pathway in glioblastoma make PD0332991 also an interesting drug for the treatment of glioblastoma. Promising results in in vitro studies, where patient derived glioblastoma cell lines showed sensitivity to PD0332991, gave motive to start in vivo studies. Outcomes of these studies have been contrasting in terms of PD0332991 efficacy within the brain: more research is necessary to conclude whether CDK4/6 inhibitor can be beneficial in the treatment of glioblastoma. PMID:26649278

  13. Isolation of a recombinant desulfurizing 4,6-diproply dibenzothiophene in n-tetradecane.

    PubMed

    Noda, Ken-Ichi; Watanabe, Kimiko; Maruhashi, Kenji

    2003-01-01

    Rhodococcus erythropolis strain KA2-5-1 is unable to desulfurize 4,6-dipropyl dibenzothiophene (DBT) in the oil phase. The dsz desulfurization gene cluster from R. erythropolis strain KA2-5-1 was transferred into 22 rhodococcal and mycobacterial strains using a transposon-transposase complex. The recombinant strain MR65, from Mycobacterium sp. NCIMB10403, was able to grow on a minimal medium supplemented with 1.0 mM 4,6-dipropyl DBT in n-tetradecane (50%, v v ) as the sole sulfur source. Resting cells of recombinant strain MR65 could desulfurize 68 mg l- of sulfur in light gas oil (LGO) containing 126 mg sulfur l-. Strain MR65 had about 1.5-times the LGO desulfurization activity of R. erythropolis strain KA2-5-1. The application of a recombinant, which is able to utilize 4,6-dipropyl DBT in the oil phase, was effective in enhancing LGO biodesulfurization.

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. Monoclinic structure of hydroxylpyromorphite Pb10(PO4)6(OH)2 - hydroxylmimetite Pb10(AsO4)6(OH)2 solid solution series

    NASA Astrophysics Data System (ADS)

    Giera, Alicja; Manecki, Maciej; Borkiewicz, Olaf; Zelek, Sylwia; Rakovan, John; Bajda, Tomasz; Marchlewski, Tomasz

    2016-04-01

    Seven samples of hydroxyl analogues of pyromorphite-mimetite solid solutions series were synthesized from aqueous solutions at 80° C in a computer-controlled chemistate: 200 mL aqueous solutions of 0.05M Pb(NO3)2 and 0.03M KH2AsO4 and/or KH2PO4 were dosed with a 0.25 mL/min rate to a glass beaker, which initially contained 100 mL of distilled water. Constant pH of 8 was maintained using 2M KOH. The syntheses yielded homogeneous fine-grained white precipitates composition of which was close to theoretical Pb10[(PO4)6-x(AsO4)x](OH)2, where x = 0, 1, 2, 3, 4, 5, 6. High-resolution powder X-ray diffraction data were obtained in transmission geometry at the beamline 11-BM at the Advanced Photon Source (Argonne National Laboratory in Illinois, USA). The structure Rietveld refinements based on starting parameters of either hexagonal hydroxylpyromorphite or monoclinic mimetite-M were performed using GSAS+EXPGUI software. Apatite usually crystallizes in the hexagonal crystal system with the space group P63/m. For the first time, however, the lowering of the hexagonal to monoclinic crystal symmetry was observed in the hydroxyl variety of pyromorphite-mimetite solid solution series. This is indicated by better fitting of the modeled monoclinic structure to the experimental data. The same is not the case for analogous calcium hydroxylapatite series Ca5(PO4)3OH - Ca5(AsO4)3OH (Lee et al. 2009). Systematical linear increase of unit cell parameters is observed with As substitution from a=9.88, b=19.75, and c=7.43 for Pb10(PO4)6(OH)2 to a=10.23, b=20.32, and c=7.51 for Pb10(AsO4)6(OH)2. A strong pseudohexagonal character (γ ≈ 120° and b ≈ 2a) of the analyzed monoclinic phases was established. This work is partially funded by AGH research grant no 11.11.140.319 and partially by Polish NCN grant No 2011/01/M/ST10/06999. Lee Y.J., Stephens P.W., Tang Y., Li W., Philips B.L., Parise J.B., Reeder R.J., 2009. Arsenate substitution in hydroxylapatite: Structural characterization

  19. Monoclinic structure of hydroxylpyromorphite Pb10(PO4)6(OH)2 - hydroxylmimetite Pb10(AsO4)6(OH)2 solid solution series

    NASA Astrophysics Data System (ADS)

    Giera, Alicja; Manecki, Maciej; Borkiewicz, Olaf; Zelek, Sylwia; Rakovan, John; Bajda, Tomasz; Marchlewski, Tomasz

    2016-04-01

    Seven samples of hydroxyl analogues of pyromorphite-mimetite solid solutions series were synthesized from aqueous solutions at 80° C in a computer-controlled chemistate: 200 mL aqueous solutions of 0.05M Pb(NO3)2 and 0.03M KH2AsO4 and/or KH2PO4 were dosed with a 0.25 mL/min rate to a glass beaker, which initially contained 100 mL of distilled water. Constant pH of 8 was maintained using 2M KOH. The syntheses yielded homogeneous fine-grained white precipitates composition of which was close to theoretical Pb10[(PO4)6‑x(AsO4)x](OH)2, where x = 0, 1, 2, 3, 4, 5, 6. High-resolution powder X-ray diffraction data were obtained in transmission geometry at the beamline 11-BM at the Advanced Photon Source (Argonne National Laboratory in Illinois, USA). The structure Rietveld refinements based on starting parameters of either hexagonal hydroxylpyromorphite or monoclinic mimetite-M were performed using GSAS+EXPGUI software. Apatite usually crystallizes in the hexagonal crystal system with the space group P63/m. For the first time, however, the lowering of the hexagonal to monoclinic crystal symmetry was observed in the hydroxyl variety of pyromorphite-mimetite solid solution series. This is indicated by better fitting of the modeled monoclinic structure to the experimental data. The same is not the case for analogous calcium hydroxylapatite series Ca5(PO4)3OH - Ca5(AsO4)3OH (Lee et al. 2009). Systematical linear increase of unit cell parameters is observed with As substitution from a=9.88, b=19.75, and c=7.43 for Pb10(PO4)6(OH)2 to a=10.23, b=20.32, and c=7.51 for Pb10(AsO4)6(OH)2. A strong pseudohexagonal character (γ ≈ 120° and b ≈ 2a) of the analyzed monoclinic phases was established. This work is partially funded by AGH research grant no 11.11.140.319 and partially by Polish NCN grant No 2011/01/M/ST10/06999. Lee Y.J., Stephens P.W., Tang Y., Li W., Philips B.L., Parise J.B., Reeder R.J., 2009. Arsenate substitution in hydroxylapatite: Structural characterization

  20. 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.…

  1. 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…

  2. 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.

  3. 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

  4. 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…

  5. 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.…

  6. 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…

  7. 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…

  8. 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…

  9. 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,…

  10. 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…

  11. 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…

  12. 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…

  13. 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.

  14. 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…

  15. Epidemiology and aetiology of C4-6 disease.

    PubMed

    Bradbury, Andrew W

    2010-10-01

    Although our understanding of chronic venous insufficiency (CVI) has improved, many important questions remain unanswered. Ensuring that patients are appropriately referred for specialist assessment and then receive evidence-based, cost-effective treatment continues to be challenging. The lifetime of risk of chronic venous ulceration (CVU) is around 1% with approximately 10% ulcers being open at any one time. The incidence skin changes disease is about 10 times greater (10%). However, many of the studies upon which these estimates are based are old and/or methodologically flawed. There is reason to believe that the incidence, prevalence and characteristics of CVI/CVU may have changed considerably over the last 10-20 years and that future change is likely. Further cross-sectional and longitudinal epidemiological studies are required to establish the size and nature of the health-care need going forward in developed and increasingly developing countries. CVI culminating CVU is primarily the result of sustained ambulatory venous hypertension, which in turn arises from superficial and/or deep venous reflux with or without deep vein obstruction. However, there are many other elements to this complex condition, for example, microvascular dysfunction; calf muscle pump efficiency; dermal inflammation; disordered fibroblast function and matrix production; failure of epithelialization; congenital and acquired thrombophilia; malnutrition, obesity and diet; and bacterial colonization. None of the currently available treatment modalities is entirely satisfactory and novel therapies based upon a clearer understanding of the disease at the psychological, genetic, mechanical, microvascular and microscopic level are required.

  16. 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…

  17. 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

  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.

  19. Computational study of Cs immobilization in the apatites Ca10(PO4)6F2, Ca4La6(SiO4)6F2 and Ca2La8(SiO4)6O2

    NASA Astrophysics Data System (ADS)

    Chartier, Alain; Meis, Constantin; Gale, Julian D.

    2001-08-01

    Incorporation and lattice migration of cesium in three apatites fluorapatite Ca10(PO4)6F2, lanthanum-fluorobritholite Ca4La6(SiO4)6F2 and lanthanum-oxyapatite Ca2La8(SiO4)6O2 have been studied theoretically. The above apatites have been first optimized by applying the ab initio Hartree-Fock method using electron core pseudopotentials. Mulliken analysis has shown the calculated anion charges in the apatite tunnels to have formal values, thus establishing the presence of ionic bonds with cations at site II (6h), particularly in Ca2La8(SiO4)6O2. These results have been used for optimizing the corresponding interactions in the interatomic potential method employed in the following. Free energy calculations have shown the preferential site for Cs and La incorporation in the three apatites to be site I (4f) and site II (6h), respectively. The calculated activation energies for Cs migration offer evidence that cesium diffusion is mainly controlled by intersite (I<-->II) jumps to adjacent vacancies. Ca2La8(SiO4)6O2 proves to have the higher immobilization capacity, because of the high activation energies characterizing all the possible lattice diffusion mechanisms.

  20. 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…

  1. 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

  2. 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…

  3. 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…

  4. 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…

  5. Dose enhancement close to platinum implants for the 4, 6, and 10 MV stereotactic radiosurgery

    SciTech Connect

    Cheung, Joel Y.C.; Ng, Ben K.P.; Yu, K.N.

    2004-10-01

    Three photon interaction processes, namely, the photoelectric effect, Compton effect, and pair production, can occur when materials with high atomic numbers are irradiated by the high- and low-energy bremsstrahlung photons from a linear accelerator. A dose enhancement, due to the photoelectric effect and pair production, near targets with platinum implants (with a high atomic number) in radiosurgery cannot be predicted by the XKnife{sup reg} radiosurgery treatment planning system. In the present work, Monte Carlo simulations using PRESTA EGS4 were employed to investigate the resulting dose enhancements from 4, 6, and 10 MV energies commonly used in the stereotactic radiosurgery system. Dose enhancements from 32% to 68% were observed close to the platinum implant for the above energies when using a 12.5 mm collimator. Comparatively higher dose enhancements were observed when using smaller collimators. It was found that this dose enhancement increased with beam energy but decreased as beam size increased.

  6. 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

  7. 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

  8. Soil sorption and plant uptake of 2,4,6-trinitrotoluene

    SciTech Connect

    Pennington, J.C.

    1988-01-01

    Potential environmental hazards are posed by the presence of 2,4,6-trinitrotoluene (TNT) contamination in soils of US Army Ammunition Plants (AAPs). Adsorption and desorption studies were conducted on soil samples collected from 13 AAPs. TNT adsorption correlated most highly with cation exchange capacity, extractable iron, clay content, and percent organic carbon. Sequential desorption indicated that almost all of the adsorbed TNT was desorbed after three sequential desorption cycles. Plant uptake of TNT and two of its principal degradation products, 4-amino-2,6-dinitrotoluene (4ADNT) and 2-amino-4,6-dinitrotoluene (2ADNT), was also investigated. Results indicated that little TNT and 4ADNT, and no 2ADNT was absorbed by leafy portions of the test plant, yellow nutsedge (Cyperus esculentus). Plant uptake was greatest from 4ADNT-treated silts, an indication that 4ADNT is more readily mobilized into the plant than TNT or 2ANDT. Greater plant uptake from silt than from clay indicated that bioavailability is reduced in the clay. The reduction in bioavailability may be due to an increase in soil sorption of TNT and its degradation products over time.

  9. 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...

  10. Effect of lead on the sorption of 2,4,6-trichlorophenol on soil and peat.

    PubMed

    Pei, Zhi-Guo; Shan, Xiao-Quan; Liu, Tao; Xie, Ya-Ning; Wen, Bei; Zhang, Shuzhen; Khan, Shahamat U

    2007-06-01

    The effect of lead on the sorption of 2,4,6-trichlorophenol (2,4,6-TCP) on soil and peat was investigated using a batch equilibration method. Lead markedly diminished the sorption of 2,4,6-TCP, and 2,4,6-TCP had little effect on lead sorption. Peat was a more effective adsorbent for 2,4,6-TCP than soil. The desorption hysteresis of 2,4,6-TCP verified the presence of high-energy sorption sites. Mechanisms of lead suppression effect on the 2,4,6-TCP sorption included the following: Firstly, lead accelerated the aggregation of colloids, the aggregates covered the surface in part and shrunk the pore sizes of the adsorbents, hence decreased the sorption of 2,4,6-TCP. Secondly, X-ray absorption and Fourier transform infrared spectroscopy study suggested that lead competed with 2,4,6-TCP for carboxylic, phenolic and Si-OH groups of organic matter and clay minerals. Such competition was partly responsible for the overall suppression effect of lead on the sorption of 2,4,6-TCP.

  11. 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…

  12. 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…

  13. 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…

  14. 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.

  15. 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.

  16. Comparison of Physical Examination and Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography 4-6 Months After Radiotherapy to Assess Residual Head-and-Neck Cancer

    SciTech Connect

    Zundel, M. Tracy; Michel, Michelle A.; Schultz, Christopher J.; Maheshwari, Mohit; Wong, Stuart J.; Campbell, Bruce H.; Massey, Becky L.; Blumin, Joel; Wilson, J. Frank; Wang, Dian

    2011-12-01

    Purpose: To retrospectively compare fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and physical examination 4-6 months after radiotherapy for assessing residual head-and-neck cancer (HNC). Methods and Materials: From July 2002 through March 2006, 52 HNC patients underwent definitive radiotherapy or chemoradiotherapy. Categoric assessments of residual tumor by PET/CT and physical examination 4-6 months after therapy were correlated and compared with clinical outcomes. Pretreatment data, including tumor stage and primary site standardized uptake value, were also gathered retrospectively and correlated with clinical outcomes. Median follow-up time was 58 months. Results: Twenty-one patients had either locoregionally 'positive' (17 of 21) or 'equivocal' (4 of 21) PET/CT scans, whereas 31 patients had locoregionally negative scans. Four patients failed treatment and had biopsy-confirmed residual or recurrent local disease. All patients, including patients with locally suspicious scans or examinations who refused biopsies, were followed clinically for a minimum of 29 months after therapy, with no other cases of treatment failure detected during this time. No patient had residual nodal disease after therapy. Sensitivities of PET/CT vs. physical examination for early detection of treatment failure were 100% vs. 50%, whereas the specificities of the two modalities were 64.6% vs. 89.6%, respectively. Higher initial T stage and American Joint Commission on Cancer stage correlated with increased incidence of positive/equivocal PET/CT results and treatment failure. Maximal standardized uptake value was not predictive of any clinical outcome. Conclusions: A negative result on PET/CT obtained 4-6 months after radiotherapy is highly sensitive and correlates with successful locoregional control. Patients with negative scans may reasonably be spared invasive diagnostic procedures, such as biopsy and neck dissection, unless recurrent disease is suspected

  17. 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.

  18. Theoretical studies on 2-diazo-4,6-dinitrophenol derivatives aimed at finding superior propellants.

    PubMed

    Liu, Yan; Wang, Lianjun; Wang, Guixiang; Du, Hongchen; Gong, Xuedong

    2012-04-01

    In an attempt to find superior propellants, 2-diazo-4,6-dinitrophenol (DDNP) and its -NO(2), -NH(2), -CN, -NC, -ONO(2), and -NF(2) derivatives were studied at the B3LYP/6-311++G level of density functional theory (DFT). Sensitivity was evaluated using bond dissociation enthalpies (BDEs) and molecular surface electrostatic potentials. The C-NO(2) bond appears to be the trigger bond during the thermolysis process for these compounds, except for the -ONO(2) and -NF(2) derivatives. Electrostatic potential results show that electron-withdrawing substituents make the charge imbalance more anomalous, which may change the strength of the bond, especially the weakest trigger bond. Most of the DDNP derivatives have the impact sensitivities that are higher than that of DDNP, making them favorable for use as solid propellants in micro-rockets. The theoretical densities (ρ), heats of formation (HOFs), detonation energies (Q), detonation pressures (P), and detonation velocities (D) of the compounds were estimated. The effects of various substituent groups on ρ, HOF, Q, D, and P were investigated. Some derivatives exhibit perfect detonation properties. The calculated relative specific impulses (I (r,sp)) of all compounds except for -NH(2) derivatives were higher than that of DDNP, and also meet the requirements of propellants.

  19. Function of the Golgi-located phosphate transporter PHT4;6 is critical for senescence-associated processes in Arabidopsis

    PubMed Central

    Hassler, Sebastian; Jung, Benjamin; Lemke, Lilia; Novák, Ondřej; Strnad, Miroslav; Martinoia, Enrico; Neuhaus, H. Ekkehard

    2016-01-01

    The phosphate transporter PHT4;6 locates to the trans-Golgi compartment, and its impaired activity causes altered intracellular phosphate compartmentation, leading to low cytosolic Pi levels, a blockage of Golgi-related processes such as protein glycosylation and hemicellulose biosynthesis, and a dwarf phenotype. However, it was unclear whether altered Pi homeostasis in pht4;6 mutants causes further cellular problems, typically associated with limited phosphate availability. Here we report that pht4;6 mutants exhibit a markedly increased disposition to induce dark-induced senescence. In control experiments, in which pht4;6 mutants and wild-type plants developed similarly, we confirmed that accelerated dark-induced senescence in mutants is not a ‘pleiotropic’ process associated with the dwarf phenotype. In fact, accelerated dark-induced senescence in pht4;6 mutants correlates strongly with increased levels of toxic NH4 + and higher sensitivity to ammonium, which probably contribute to the inability of pht4;6 mutants to recover from dark treatment. Experiments with modified levels of either salicylic acid (SA) or trans-zeatin (tZ) demonstrate that altered concentrations of these compounds in pht4;6 plants act as major cellular mediators for dark-induced senescence. This conclusion gained further support from the notion that the expression of the pht4;6 gene is, in contrast to genes coding for major phosphate importers, substantially induced by tZ. Taken together, our findings point to a critical function of PHT4;6 to control cellular phosphate levels, in particular the cytosolic Pi availability, required to energize plant primary metabolism for proper plant development. Phosphate and its allocation mediated by PHT4;6 is critical to prevent onset of dark-induced senescence. PMID:27325894

  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. 45 CFR 4.6 - Materials related to petitions under the National Vaccine Injury Compensation Program.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Vaccine Injury Compensation Program. 4.6 Section 4.6 Public Welfare DEPARTMENT OF HEALTH AND HUMAN... Vaccine Injury Compensation Program. Notwithstanding the provisions of §§ 4.1, 4.2, and 4.3, service of..., shall be served upon the Director, Division of Vaccine Injury Compensation, Office of Special...

  3. 45 CFR 4.6 - Materials related to petitions under the National Vaccine Injury Compensation Program.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Vaccine Injury Compensation Program. 4.6 Section 4.6 Public Welfare Department of Health and Human... Vaccine Injury Compensation Program. Notwithstanding the provisions of §§ 4.1, 4.2, and 4.3, service of..., shall be served upon the Director, Division of Vaccine Injury Compensation, Office of Special...

  4. 45 CFR 4.6 - Materials related to petitions under the National Vaccine Injury Compensation Program.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Vaccine Injury Compensation Program. 4.6 Section 4.6 Public Welfare DEPARTMENT OF HEALTH AND HUMAN... Vaccine Injury Compensation Program. Notwithstanding the provisions of §§ 4.1, 4.2, and 4.3, service of..., shall be served upon the Director, Division of Vaccine Injury Compensation, Office of Special...

  5. 45 CFR 4.6 - Materials related to petitions under the National Vaccine Injury Compensation Program.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Vaccine Injury Compensation Program. 4.6 Section 4.6 Public Welfare DEPARTMENT OF HEALTH AND HUMAN... Vaccine Injury Compensation Program. Notwithstanding the provisions of §§ 4.1, 4.2, and 4.3, service of..., shall be served upon the Director, Division of Vaccine Injury Compensation, Office of Special...

  6. 45 CFR 4.6 - Materials related to petitions under the National Vaccine Injury Compensation Program.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Vaccine Injury Compensation Program. 4.6 Section 4.6 Public Welfare DEPARTMENT OF HEALTH AND HUMAN... Vaccine Injury Compensation Program. Notwithstanding the provisions of §§ 4.1, 4.2, and 4.3, service of..., shall be served upon the Director, Division of Vaccine Injury Compensation, Office of Special...

  7. 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.

  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. 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.

  10. Assessing 2,4,6-trinitrotoluene (TNT)-contaminated soil using three different earthworm test methods.

    PubMed

    Schaefer, M

    2004-01-01

    Within the scope of a phytoremediation project, the toxicity of 2,4,6-trinitrotoluene (TNT) contaminated soil (and its toxic metabolites) on earthworms was assessed. In addition to the standard acute and reproduction tests (ISO 11268), an avoidance response test was applied. The test methods covered all important ecological relevant endpoints (acute, chronic, behavioral). At a concentration of 1142 mg/kg, TNT caused significant toxic effects in all test methods, but at lower test concentrations no significant acute or reproduction toxic effects could be observed. The avoidance response test, however, showed significant repellent effects at a concentration of 29 mg/kg TNT and therefore proved to be more sensitive than the other tests in this case. Results of the earthworm tests compared well with results of an ecotoxicological biotest battery. Thus, earthworm toxicity tests are useful tools for terrestrial risk assessment but require a hierarchy of test designs that differ in effect levels (behavior, sublethal, lethal). Whereas higher concentrations of a pollutant can easily be assessed with the acute test (which requires lethal concentrations to show an effect), contaminated soils with lower (sublethal) pollutant concentrations require more sensitive test methods such as reproduction or behavioral tests in their risk assessment.

  11. 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…

  12. Penta- and 2,4,6-tri-chlorophenol biodegradation during municipal solid waste anaerobic digestion.

    PubMed

    Limam, Intissar; Limam, Rim Driss; Mezni, Mohamed; Guenne, Angéline; Madigou, Céline; Driss, Mohamed Ridha; Bouchez, Théodore; Mazeas, Laurent

    2016-08-01

    In this study isotopic tracing using (13)C labelled pentachlorophenol (PCP) and 2,4,6-trichlorophenol (2,4,6-TCP) is proposed as a tool to distinguish the loss of PCP and 2,4,6-TCP due to biodegradation from other physical processes. This isotopic approach was applied to accurately assess in situ PCP and 2,4,6-TCP degradation under methanogenic conditions in several microcosms made up of household waste. These microcosms were incubated in anaerobic conditions at 35°C (mesophilic) and 55°C (thermophilic) without agitation. The volume of biogas produced (CH4 and CO2), was followed for a period of 130 days. At this stage of stable methanogenesis, (13)C6-PCP and (13)C6-2,4,6-TCP were introduced anaerobically in microcosms and its monitoring at mesophilic and thermophilic conditions was performed in parallel by gas chromatography mass spectrometry (GC-MS) and gas chromatography isotope-ratio mass spectrometry (GC-IRMS). This study proved the almost total dechlorination of bioavailable PCP and 2,4,6-TCP into 4-CP at 35°C. Nevertheless, high rate adsorption in particular materials of the two compounds was observed. Furthermore, Carbon-13 Nuclear Magnetic Resonance ((13)C-NMR) Spectroscopy analysis of (13)C labelled 2,4,6-TCP mesophilic incubations showed the partial mineralization of 4-CP at 35°C to acetate and then to HCO(3-). Consequently, NMR results confirm the biogas isotopic results indicating the mineralization of (13)C labelled 2,4,6-TCP into (13)C (CH4 and CO2). Concerning (13)C labelled PCP mesophilic incubations, the isotopic composition of the biogas still natural until the day 262. In contrast, no dechlorination was observed at 55°C. Thus PCP and 2,4,6-TCP were persistent in thermophilic conditions.

  13. Biodegradation of 2,4,6-tribromophenol during transport in fractured chalk.

    PubMed

    Arnon, Shai; Adar, Eilon; Ronen, Zeev; Nejidat, Ali; Yakirevich, Alexander; Nativ, Ronit

    2005-02-01

    The effect of physicochemical conditions (residence time, oxygen concentrations, and chalk characteristics) on the biodegradation of 2,4,6-tribromophenol (TBP) during transport was investigated in low-permeability fractured-chalk cores. Long-term (approximately 600 d) biodegradation experiments were conducted in two cores (approximately 21 cm diameter, 31 and 44 cm long, respectively), intersected by a natural fracture. TBP was used as a model contaminant and as the sole carbon source for aerobic microbial activity. Bacterial isolates were recovered and identified by both Biolog identification kit and 16S rDNA sequences from batch enrichment cultures. One of the strains, with 98% similarity (based on the 16S rDNA data) to Achromobacter xylosoxidans, was shown to have the ability to degrade TBP in the presence of chalk. The decrease in TBP concentration along the fracture due to biodegradation was not affected by reducing the residence time from 49 to 8 min. In contrast, adding oxygen to the water at the inlet and increasing the flow rates improved TBP removal. Although the matrix pore-size distribution limits microbial activity to the fracture void, the chalk appears to provide an excellent environment for biodegradation activity. Approximately 90% of TBP removal occurred within 10 cm of the TBP source, indicating that in-situ bioremediation can be used to remove organic contaminants in low-permeability fractured rocks if nutrient-delivery pathways within the aquifer are secured.

  14. Induction of apoptosis of 2,4',6-trihydroxybenzophenone in HT-29 colon carcinoma cell line.

    PubMed

    Lay, Ma Ma; Karsani, Saiful Anuar; Malek, Sri Nurestri Abd

    2014-01-01

    2,4',6-Trihydroxy-4-methoxybenzophenone was isolated from the ethyl acetate fraction of Phaleria macrocarpa (Scheff.) Boerl. fruits. It was found to inhibit cell proliferation in HT-29 human colon carcinoma cell line but caused little damage to WRL-68 normal human liver and MRC-5 normal human fibroblast lung cell lines. The compound was found to sharply affect the viability of HT-29 cells in a dose- and time-dependent manner. HT-29 cells treated with the compound showed morphological changes under microscopic examination such as cell shrinkage, membrane blebbing, DNA fragmentation, and the occurrence of apoptotic nuclei. The percentage of early apoptotic, late apoptotic, and dead or necrotic cells was determined by flow cytometry using annexin V-FTIC/PI staining. In addition, flow cytometry showed that, when the HT-29 cells were treated with 115 µM of the compound, it resulted in G0/G1 phase arrest in a time-dependent manner. Western blot revealed an upregulation of PUMA, Bak, Bcl-2, and Mcl-1 proteins suggesting that the compound induced apoptosis in HT-29 cells by regulating these proteins. PMID:24579081

  15. Photodissociation of 2, 4, 6-trinitrotoluene with a Nd:YAG laser at 532nm

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Shen, Ruiqi; Ye, Yinghua; Wu, Lizhi; Hu, Yan; Zhu, Peng

    2015-05-01

    2, 4, 6-Trinitrotoluene (TNT) belongs to the group of aromatic nitro compounds which have extended use in industrial applications, in particular as explosives or additives to explosives. Understanding the initial step of laser induced decomposition of common explosives is important to the reliability and safety of laser initiators and firing systems. Lasers coupled with mass spectrometer find wide application in photochemical studies for identification of different ions formed due to photoexcitation/ionization of molecules by laser. In this paper, a pulsed Nd: YAG (15ns, 532nm) laser was used for ionizating the condensed TNT sample, and the ions produced in the ionization process were detected by a time of flight mass spectrometer (TOFMS). The influence of laser fluence and the delay time to the decomposition was also studied. According to the assignment of both positive and negative ions, possible laser induced dissociation pathways were proposed. The results may tell much about the initiation process and the chemical reaction that may occur in TNT when exposed to laser pulse.

  16. On the common modulus attack into the LUC4,6 cryptosystem

    NASA Astrophysics Data System (ADS)

    Wong, Tze Jin; Said, Mohd Rushdan Md; Othman, Mohamed; Koo, Lee Feng

    2015-05-01

    The LUC4,6 cryptosystem is a system analogy with RSA cryptosystem and extended from LUC and LUC3 cryptosystems. The process of encryption and decryption are derived from the fourth order linear recurrence sequence and based on Lucas function. This paper reports an investigation into the common modulus attack on the LUC4,6 cryptosystem. In general, the common modulus attack will be succeeded if the sender sends the plaintext to two users used same RSA-modulus and both of encryption keys of them are relatively prime to each other. However, based on the characteristics of high order Lucas sequence, the LUC4,6 cryptosystem is unattackable

  17. Graphene-based electrochemical sensor for detection of 2,4,6-trinitrotoluene (TNT) in seawater: the comparison of single-, few-, and multilayer graphene nanoribbons and graphite microparticles.

    PubMed

    Goh, Madeline Shuhua; Pumera, Martin

    2011-01-01

    The detection of explosives in seawater is of great interest. We compared response single-, few-, and multilayer graphene nanoribbons and graphite microparticle-based electrodes toward the electrochemical reduction of 2,4,6-trinitrotoluene (TNT). We optimized parameters such as accumulation time, accumulation potential, and pH. We found that few-layer graphene exhibits about 20% enhanced signal for TNT after accumulation when compared to multilayer graphene nanoribbons. However, graphite microparticle-modified electrode provides higher sensitivity, and there was no significant difference in the performance of single-, few-, and multilayer graphene nanoribbons and graphite microparticles for the electrochemical detection of TNT. We established the limit of detection of TNT in untreated seawater at 1 μg/mL.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. Seminar on the Associated Schools: N'Djamena, Chad, 4-6 May 1982.

    ERIC Educational Resources Information Center

    International Understanding at School, 1982

    1982-01-01

    Recommendations of a seminar held in N'Djamena, Chad, from May 4-6, 1982, to support the activities of the Associated Schools project intended to promote international understanding and peace are described. (RM)

  3. COMPARISON OF BIOMARKERS IN WORKERS EXPOSED TO 2,4,6-TRINITROTOLUENE

    EPA Science Inventory

    2,4,6-Trinitrotoluene (TNT) is an important occupational and environmental pollutant. In TNT-exposed humans, the notable toxic manifestations have included aplastic anemia, toxic hepatitis, cataracts, hepatomegaly, and liver cancer. Therefore, we developed methods to biomonitor w...

  4. Desulfurization of 2,4,6,8-tetraethyl dibenzothiophene by recombinant Mycobacterium sp. strain MR65.

    PubMed

    Watanabe, Kimiko; Noda, Ken-ichi; Konishi, Jin; Maruhashi, Kenji

    2003-09-01

    Recombinant Mycobacterium sp. strain MR65 harboring dszABCD genes was used to desulfurize alkyl dibenzothiophenes (Cx-DBTs) in n-hexadecane. The specific desulfurization activity for 2,4,6,8-tetraethyl DBT (C8-DBT) by DszC enzyme was about twice that for 4,6-dipropyl DBT (C6-DBT). However, the degradation rate of 2,4,6,8-tetraethyl DBT in n-hexadecane by resting cells of strain MR65 was only about 40% of that of 4,6-dipropyl DBT. These results indicated that the desulfurization ability for Cx-DBTs by resting cells depends on carbon number substituted at positions 4 and 6 and that the rate-limiting step in the desulfurization reaction of highly alkylated Cx-DBTs is the transfer process from the oil phase into the cell.

  5. Spiro[2.4]hepta-4,6-dienes: synthesis and application in organic synthesis

    NASA Astrophysics Data System (ADS)

    Menchikov, L. G.; Nefedov, O. M.

    2016-03-01

    This review integrates and describes systematically the data in the field of spiro[2.4]hepta-4,6-dienes published in the past 15 years. The changes in the development of studies that took place during this period are noted. The methods for the synthesis, the reactivity details and key chemical transformations of spiro[2.4]hepta-4,6-dienes are considered, with the emphasis on applications of these compounds in organic synthesis. The bibliography includes 207 references.

  6. Inhibitory activities against rice pathogens of 8-hydroxy-2,4,6-octatriynamide from Agrocybe sp.

    PubMed

    Zheng, Yongbiao; Xu, Xiaoping; Wu, Yabin

    2016-03-01

    8-Hydroxy-2,4,6-octatriynamide, a natural polyacetylene with inhibitory activities against rice pathogens, was isolated from the liquid fermentation broth of strain Agrocybe sp. YB2005 during screening for new natural chemical agents to control rice pathogens. 8-hydroxy-2,4,6-octatriynamide was purified by consecutive chromatography over a Cl8 reversed phase silica gel, sephadex LH-20 and silica gel. The chemical structure of 8-hydroxy-2,4,6-octatriynamide was elucidated through spectroscopic analyses, including 1D- and 2D-NMR, ESI mass spectrometry and X-ray single crystal diffraction. Bioassays showed that 8-hydroxy-2,4,6-octatriynamide could significantly inhibit growth of Xanthomonas oryzae with an MIC of 53.1 μM in a 96-well plate and the growth of Rhizoctonia solani at 1.02 mM in a 24-well plate. When rice leaves were inoculated with Magnaporthe grisea and cultured in artificial nutrition liquid containing 0.34 mM 8-hydroxy-2,4,6-octatriynamide, no rice blast was observed. The present study implied that 8-hydroxy-2,4,6-octatriynamide could be a candidate agent against rice pathogens. PMID:26861586

  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. STS-113 Mission Highlights Resource Tape Flight Days 4-6 Tape: 2 of 4

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This video, Part 2 of 4, shows the activities of the crew of the Space Shuttle Endeavor on flight days 4-6 of STS-113. The crew consists of Commander Jim Wetherbee, Pilot Paul Lockhart, and Mission Specialists Michael Lopez-Alegria and John Herrington. On flight day 4, The P1 truss was transfered from Canadarm on Endeavour to Canadarm 2 on the ISS, and aligned with the S0 Truss for attachment. The mission specialists connected utility cables between the trusses on an extravehicular activity (EVA). Flight day 5 was Commander Wetherbee's 50th birthday, and the video includes a clip from The Tonight Show in which Jay Leno wishes him a happy birthday. Intravehicular activity on flight day 5 includes Peggy Whitsun of the outgoing Expedition 5 crew of the International Space Station (ISS) showing incoming Expedition 6 crew members Ken Bowersox and Don Pettit how to replace valves on the ISS CO2 removal system. The video also includes an interior tour of Endeavour and the ISS, and an brief exterior tour of the ISS. On flight day 6 Lopez-Alegria and Herrington attach a television antenna to the P1 truss, and are shown using a handcart on the truss several times. The video includes several Earth views, including one of the west coast of South America.

  9. UV-VIS spectroscopy of 2,4,6-trinitrotoluene-hydroxide reaction.

    PubMed

    Felt, Deborah R; Larson, Steven L; Valente, Edward J

    2002-10-01

    Contamination of groundwater, surface water and soil by explosives has occurred at military sites throughout the world as a result of manufacture of explosive compounds, assembly of munitions, and deployment of explosives containing devices. Due to the adverse effects of explosives on humans and other natural receptors, a low cost means of decontaminating these areas of contamination is needed. Base-induced transformation of explosives has shown promise as a rapid, low cost, and minimally resource-intensive technology for detoxifying explosives in soil and water. In order to understand the reaction mechanism, a reaction mixture of 2:1:1 (water:2,4,6-trinitrotoluene (TNT):1 N KOH) was analyzed by UV/VIS spectrometry from 190 to 1,100 nm. Time course measurements were conducted at 25, 20, 15, and 12 degrees C. A factor analysis program was used to analyze the spectral data. Principal component analysis indicated that six principal components explained the spectra to within experimental error, with four factors explaining the majority of the variance. Test spectral vectors for four components were developed, including TNT, two intermediates, and the final product, and were tested against the abstract vectors. Two possible reaction mechanisms were suggested and tested to explain the spectral data.

  10. Portable 4.6 Micrometers Laser Absorption Spectrometer for Carbon Monoxide Monitoring and Fire Detection

    NASA Technical Reports Server (NTRS)

    Briggs, Ryan M.; Frez, Clifford; Forouhar, Siamak; May, Randy D.; Ruff, Gary A.

    2013-01-01

    The air quality aboard manned spacecraft must be continuously monitored to ensure crew safety and identify equipment malfunctions. In particular, accurate real-time monitoring of carbon monoxide (CO) levels helps to prevent chronic exposure and can also provide early detection of combustion-related hazards. For long-duration missions, environmental monitoring grows in importance, but the mass and volume of monitoring instruments must be minimized. Furthermore, environmental analysis beyond low-Earth orbit must be performed in-situ, as sample return becomes impractical. Due to their small size, low power draw, and performance reliability, semiconductor-laser-based absorption spectrometers are viable candidates for this purpose. To reduce instrument form factor and complexity, the emission wavelength of the laser source should coincide with strong fundamental absorption lines of the target gases, which occur in the 3 to 5 micrometers wavelength range for most combustion products of interest, thereby reducing the absorption path length required for low-level concentration measurements. To address the needs of current and future NASA missions, we have developed a prototype absorption spectrometer using a semiconductor quantum cascade laser source operating near 4.6 micrometers that can be used to detect low concentrations of CO with a compact single-pass absorption cell. In this study, we present the design of the prototype instrument and report on measurements of CO emissions from the combustion of a variety of aerospace plastics.

  11. Chronic toxicity of 2,4,6-trinitrotoluene to a marine polychaete and an estuarine amphipod

    SciTech Connect

    Green, A.; Moore, D.; Farrar, D.

    1999-08-01

    The chronic toxicity of sediment-associated 2,4,6-trinitrotoluene (TNT) to the marine polychaete Neanthes arenaceodentata and the estuarine amphipod Leptocheirus plumulosus was evaluated. Test organisms were exposed to sediments spiked with radiolabeled TNT for 28 d, after which time the endpoints of mortality, growth, and reproduction (L. plumulosus only) were assayed and compared against the TNT tissue concentrations as well as the TNT sediment concentrations. Survival was significantly reduced at a tissue concentration of 61 {micro}g TNT/g wet wt tissue in N. arenaceodentata and L. plumulosus with enhancement (significant for N. arenaceodentata) occurring at the lower TNT concentrations. Growth was significantly reduced at the highest TNT exposure of 10.0 {micro}g TNT/g wet wt tissue in L. plumulosus. Reproduction was significantly reduced at a tissue concentration of 6.3 {micro}g TNT/g wet wt tissue in L. plumulosus. The results of this study demonstrate that both N. arenaceodentata and L. plumulosus are sensitive to the presence of sediment-associated TNT and that more information is needed about the toxicity of TNT to benthic fauna to facilitate risk assessment and management of TNT-contaminated sites.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. Biotransformation of 2,4,6-trinitrotoluene with Phanaerochaete chrysosporium in agitated cultures at pH 4. 5

    SciTech Connect

    Hawari, J.; Halasz, A.; Beaudet, S.; Paquet, L. . Biotechnology Research Inst.); Ampleman, G.; Thiboutot, S. . Defence Research Establishment Valcartier)

    1999-07-01

    The biotransformation of 2,4,6-trinitrotoluene (TNT) by Phanerochaete chrysosporium with molasses and citric acid at pH 4.5 was studied. In less than 2 weeks, TNT disappeared completely, but mineralization did not exceed 1%. A time study revealed the presence of several intermediates, marked by the initial formation of two monohydroxylaminodinitrotoluenes (2- and 4-HADNT) followed by their successive transformation to several other products, including monoaminodinitrotoluenes (ADNT). A group of nine acylated intermediates were also detected. They included 2-N-acetylamido-4,6-dinitrotoluene and its p isomer, 2-formylamido-4,6-dinitrotoluene and its p isomer (as acylated ADNT), 4-N-acetylamino-2-amino-6-nitrotoluene and 4-N-formylamido-2-amino-6-nitrotoluene (as acetylated DANT), 4-N-acetylhydroxy-2,6-dinitrotoluene and 4-N-acetoxy-2,6-dinitrotoluene (as acetylated HADNT), and finally 4-N-acetylamido-2-hydroxylamino-6-nitrotoluene. Furthermore, a fraction of HADNTs were found to rearrange to their corresponding phenolamines, while another group dimerized to azoxytoluenes which in turn transformed to azo compounds and eventually to the corresponding hydrazo derivatives. After 30 days, all of these metabolites, except traces of 4-ADNT and the hydrazo derivatives, disappeared, but mineralization did not exceed 10% even after the incubation period was increased to 120 days.

  18. 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.

  19. 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.

  20. Selective impact of CDK4/6 suppression on patient-derived models of pancreatic cancer

    PubMed Central

    Witkiewicz, Agnieszka K.; Borja, Nicholas A.; Franco, Jorge; Brody, Jonathan R.; Yeo, Charles J.; Mansour, John; Choti, Michael A.; McCue, Peter; Knudsen, Erik S.

    2015-01-01

    Pancreatic ductal adenocarcinoma (PDA) harbors an exceedingly poor prognosis, and is generally considered a therapy-recalcitrant disease due to poor response to conventional chemotherapy coupled with non-actionable genetic drivers (e.g. KRAS mutations). However, PDA frequently loses p16ink4a, thereby leading to deregulation of CDK4/6. Surprisingly, in established cell models and xenografts, CDK4/6 inhibition has a modest effect on proliferation and resistance develops rapidly. To determine if such weak response was an intrinsic feature of PDA, we developed primary tumor explants that maintain the tumor environment and recapitulate feuture of primary PDA. The CDK4/6 inhibitor PD-0332991 was highly efficient at suppressing proliferation in 14 of the 15 explants. In the single resistant explant, we identified the rare loss of the RB tumor suppressor as the basis for resistance. Patient-derived xenografts (PDXs) were developed in parallel, and unlike the xenografts emerging from established cell lines, the PDXs maintained the histoarchitecture of the primary tumor. These PDXs were highly sensitive to CDK4/6 inhibition, yielding a complete suppression of PDA proliferation. Together, these data indicate that primary PDA is sensitive to CDK4/6 inhibition, that specific biomarkers can delineate intrinsic resistance, and that established cell line models may not represent an adequate means for evaluating therapeutic sensitivities. PMID:26158861

  1. Selective impact of CDK4/6 suppression on patient-derived models of pancreatic cancer.

    PubMed

    Witkiewicz, Agnieszka K; Borja, Nicholas A; Franco, Jorge; Brody, Jonathan R; Yeo, Charles J; Mansour, John; Choti, Michael A; McCue, Peter; Knudsen, Erik S

    2015-06-30

    Pancreatic ductal adenocarcinoma (PDA) harbors an exceedingly poor prognosis, and is generally considered a therapy-recalcitrant disease due to poor response to conventional chemotherapy coupled with non-actionable genetic drivers (e.g. KRAS mutations). However, PDA frequently loses p16ink4a, thereby leading to deregulation of CDK4/6. Surprisingly, in established cell models and xenografts, CDK4/6 inhibition has a modest effect on proliferation and resistance develops rapidly. To determine if such weak response was an intrinsic feature of PDA, we developed primary tumor explants that maintain the tumor environment and recapitulate feuture of primary PDA. The CDK4/6 inhibitor PD-0332991 was highly efficient at suppressing proliferation in 14 of the 15 explants. In the single resistant explant, we identified the rare loss of the RB tumor suppressor as the basis for resistance. Patient-derived xenografts (PDXs) were developed in parallel, and unlike the xenografts emerging from established cell lines, the PDXs maintained the histoarchitecture of the primary tumor. These PDXs were highly sensitive to CDK4/6 inhibition, yielding a complete suppression of PDA proliferation. Together, these data indicate that primary PDA is sensitive to CDK4/6 inhibition, that specific biomarkers can delineate intrinsic resistance, and that established cell line models may not represent an adequate means for evaluating therapeutic sensitivities.

  2. Preparation of deuterium-labeled biotransformation products of 2,4,6-trinitrotoluene.

    PubMed

    Junk, Thomas; Carr, Jason A

    2013-06-15

    Methods for the preparation of deuterium-labeled analogs to six prominent biotransformation products of the explosive 2,4,6-trinitrotoluene were developed. These are useful as reference standards for stable isotope dilution techniques and for solid state (2)H NMR spectroscopic studies. Although syntheses for most of the target compounds in protiated form had been reported in the past, most of those were found to be poorly suited for the preparation of the deuterated materials. Selective reduction of [(2)H5]trinitrotoluene furnished [(2)H5]-4,6-dinitro-2-hydroxylaminotoluene, [(2)H5]-2,6-dinitro-4-hydroxylaminotoluene, [(2)H5]-2-amino-4,6-dinitrotoluene, and [(2)H5]-4-amino-2,6-dinitrotoluene. The syntheses of [(2)H10]-2,2'-azo-4,4',6,6'-tetranitrotoluene and [(2)H10]-4,4'-azo-2,2',6,6'-tetranitrotoluene were accomplished by selective oxidation of [(2)H5]-2-amino-4,6-dinitrotoluene and [(2)H5]-4-amino-2,6-dinitrotoluene, respectively.

  3. Vicarious nucleophilic substitution to prepare 1,3-diamino-2,4,6-trinitrobenzene or 1,3,5-triamino-2,4,6-trinitrobenzene

    DOEpatents

    Mitchell, Alexander R.; Pagoria, Philip F.; Schmidt, Robert D.

    1996-01-01

    The present invention relates to a process to produce 1,3-diamino-2,4,6-trinitrobenzene (DATB) or 1,3,5-triamino-2,4,6,-trinitrobenzene (TATB) by: (a) reacting at ambient pressure and a temperature of between about 0.degree. and 50.degree. C. for between about 0.1 and 24 hr, a trinitroaromatic compound of structure V: ##STR1## wherein X, Y, and Z are each independently selected from --H, or --NH.sub.2, with the proviso that at least 1 or 2 of X, Y, and Z are hydrogen, with an amount effective to produce DATB or TATB of 1,1,1-trialkylhydrazinium halide wherein alkyl is selected from methyl, ethyl, propyl or butyl and halide is selected from chloride, bromide or iodide. in the presence of a strong base selected from sodium butoxide, potassium butoxide, potassium propoxide, sodium propoxide, sodium ethoxide, potassium ethoxide, sodium methoxide, potassium methoxide, and combinations thereof; in a solvent selected from the group consisting of methanol, ethanol, propanol, butanol, dimethylsulphoxide, N-methylpyrrolidone, hexamethylphosphoramide, dimethylformide, dimethylacetamide and mixtures thereof, provided that when alcohols are present primarily DATB and picramide is formed; and (b) isolating the DATB or TATB produced. DATB and TATB are useful specialty explosives. TATB is also used for the preparation of benzenehexamine, a starting material for the synthesis of novel materials (optical imaging devices, liquid crystals, ferromagnetic compounds).

  4. Vicarious nucleophilic substitution to prepare 1,3-diamino-2,4,6-trinitrobenzene or 1,3,5-triamino-2,4,6-trinitrobenzene

    DOEpatents

    Mitchell, A.R.; Pagoria, P.F.; Schmidt, R.D.

    1996-10-29

    The present invention relates to a process to produce 1,3-diamino-2,4,6-trinitrobenzene (DATB) or 1,3,5-triamino-2,4,6,trinitrobenzene (TATB) by: (a) reacting at ambient pressure and a temperature of between about 0 and 50 C for between about 0.1 and 24 hr, a trinitroaromatic compound of the structure shown within where X, Y, and Z are each independently selected from --H, or --NH{sub 2}, with the proviso that at least 1 or 2 of X, Y, and Z are hydrogen, with an amount effective to produce DATB or TATB, or 1,1,1-trialkylhydrazinium halide wherein alkyl is selected from methyl, ethyl, propyl or butyl and halide is selected from chloride, bromide or iodide, in the presence of a strong base selected from sodium butoxide, potassium butoxide, potassium propoxide, sodium propoxide, sodium ethoxide, potassium ethoxide, sodium methoxide, potassium methoxide, and combinations thereof; in a solvent selected from the group consisting of methanol, ethanol, propanol, butanol, dimethylsulfoxide, N-methylpyrrolidone, hexamethylphosphoramide, dimethylformide, dimethylacetamide and mixtures thereof, provided that when alcohols are present primarily DATB and picramide is formed; and (b) isolating the DATB or TATB produced. DATB and TATB are useful specialty explosives. TATB is also used for the preparation of benzenehexamine, a starting material for the synthesis of novel materials (optical imaging devices, liquid crystals, ferromagnetic compounds).

  5. Design and calibration of pulsed vapor generators for 2,4,6-trinitrotoluene, cyclo-1,3,5-trimethylene-2,4,6-trinitramine, and pentaerythritol tetranitrate

    SciTech Connect

    Davies, J.P.; Blackwood, L.G.; Davis, S.G.; Goodrich, L.D.; Larson, R.A. )

    1993-11-01

    Computer-controlled pulsed explosive vapor generators for 2,4,6-trinitrotoluene (TNT), cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX), and pentaerythritol (PETN) were built and calibrated to support an independent validation and verification facility for explosive detection systems for the Federal Aviation Administration at the Idaho National Engineering Laboratory. The explosive vapor generators will be used as quantitative vapor standards to establish the lower limits of detection of explosive detection systems. The generators were constructed using pure explosive suspended on quartz beads which were then loaded into a stainless steel tube. The tube was coiled and placed into a temperature-controlled chamber. A carrier gas (ultrapure air) was passed through the coil to carry the explosive molecules. The generators are capable of delivering a pulse of varying explosive mass through the control of coil temperature, airflow rate, and pulse width. Preliminary calibrations have been completed in the picogram to nanogram range using an ion mobility spectrometer as the calibrating instrument. 8 refs., 5 figs., 6 tabs.

  6. 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

  7. Phase I study of palbociclib, a cyclin-dependent kinase 4/6 inhibitor, in Japanese patients.

    PubMed

    Tamura, Kenji; Mukai, Hirofumi; Naito, Yoichi; Yonemori, Kan; Kodaira, Makoto; Tanabe, Yuko; Yamamoto, Noboru; Osera, Shozo; Sasaki, Masaoki; Mori, Yuko; Hashigaki, Satoshi; Nagasawa, Takashi; Umeyama, Yoshiko; Yoshino, Takayuki

    2016-06-01

    This phase I study in Japanese patients evaluated the safety, pharmacokinetics, and preliminary efficacy of palbociclib, a highly selective and reversible oral cyclin-dependent kinase 4/6 inhibitor, as monotherapy for solid tumors (part 1) and combined with letrozole as first-line treatment of postmenopausal patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer (part 2). Part 1 evaluated palbociclib 100 and 125 mg once daily (3 weeks on/1 week off; n = 6 each group) to determine the maximum tolerated dose. Part 2 evaluated palbociclib maximum tolerated dose (125 mg) plus letrozole 2.5 mg (n = 6). The most common treatment-related adverse event was neutropenia (all grades/grade 3/4): 100 mg, 83%/67%; 125 mg, 67%/33%; and palbociclib plus letrozole, 100%/83%. Heavier pretreatment with chemotherapy may have resulted in higher neutropenia rates observed with the 100-mg dose. Palbociclib exposure was higher with 125 vs 100 mg (mean area under the plasma concentration-time curve over dosing interval [τ]: 1322 vs 547.5 ng·h/mL [single dose], 2838 vs 1276 ng·h/mL [multiple dose]; mean maximum plasma concentration: 104.1 vs 41.4 ng/mL [single dose], 185.5 vs 77.4 ng/mL [multiple dose]). Half-life was 23-26 h. No drug-drug interactions between palbociclib and letrozole occurred. Four patients had stable disease (≥24 weeks in one patient with rectal cancer [100 mg] and one with esophageal cancer [125 mg]) in part 1; two patients had partial response and two had stable disease (both ≥24 weeks) in part 2. Palbociclib at the 125-mg dose (schedule 3/1) was tolerated and is the recommended dose for monotherapy and letrozole combination therapy in Japanese patients. The trials are registered with www.ClinicalTrials.gov: A5481010 and NCT01684215.

  8. 2D analogues of the inverted hexagonal phase self-assembled from 4,6-dialkoxylated isophthalic acids at solid-liquid interfaces

    NASA Astrophysics Data System (ADS)

    Klymchenko, Andrey S.; Furukawa, Shuhei; Balandina, Tanya; Müllen, Klaus; van der Auweraer, Mark; de Feyter, Steven

    2010-09-01

    Self-assembly of organic molecules at solid-liquid interfaces is a route for developing novel functional materials on surfaces and modeling assembly phenomena in 3D. 5-Alkoxylated isophthalic acids (ISA) are known to self-assemble into two-dimensional (2D) lamellae at the interface between a surface of Au(111) or HOPG (highly oriented pyrolytic graphite) and a solvent. Presently, the self-assembly of 4,6-dialkoxylated isophthalic acid derivatives with variable alkyl chain length is investigated at Au(111)-water, Au(111)-tetradecane and HOPG-tetradecane interfaces with a particular focus on the first one. The main aspect of this study is to evaluate the role of the molecular geometry and different interactions in the 2D assembly of amphiphilic molecules. In contrast to 5-alkoxylated ISA, 4,6-dialkoxylated ISA derivatives self-assemble preferentially into arrays of cyclic pentameric/hexameric structures, which appear as 2D analogues of the inverted hexagonal phase of lipids. As a general trend, the derivatives bearing shorter alkyl chains show a higher level of ordering at Au(111)-liquid interfaces. In particular, at the Au(111)-water interface, the 4,6-diheptyloxy ISA derivative forms exclusively pentamers, which are arranged in a quasi-hexagonal lattice. Moreover, the cyclic pentameric features are not empty but host a single isophthalic acid residue which is found to be dynamic. Finally, the packing of the diheptyloxy derivative shows a distinct potential dependence: while at more negative potentials the pentameric arrangement is converted into lamellae, at more positive potentials a loosely packed zig-zag pattern is formed. The present results show that at different solid-liquid interfaces 4,6-dialkoxylated ISA derivatives tend to form cyclic structures that are 2D analogues of an inverted hexagonal phase, akin to lipids having two hydrophobic alkyl chains and a small polar head group. Moreover, the substrate potential at the Au(111)-water interface can tune the

  9. Therapeutic Targeting of the Cyclin D3:CDK4/6 Complex in T Cell Leukemia

    PubMed Central

    Sawai, Catherine; Freund, Jacquelyn; Oh, Philmo; Ndiaye-Lobry, Delphine; Bretz, Jamieson C.; Strikoudis, Alexandros; Genesca, Lali; Trimarchi, Thomas; Kelliher, Michelle A.; Clark, Marcus; Soulier, Jean; Chen-Kiang, Selina; Aifantis, Iannis

    2012-01-01

    SUMMARY D-type cyclins form complexes with cyclin dependent kinases (CDK4/6), and promote cell cycle progression. Although cyclin D functions appear largely tissue specific, we demonstrate that cyclin D3 has unique functions in lymphocyte development and cannot be replaced by cyclin D2, which is also expressed during blood differentiation. We show that only combined deletion of p27Kip1 and Rb is sufficient to rescue the development of Ccnd3−/− thymocytes. Furthermore, we show that a small molecule targeting the kinase function of cyclin D3:CDK4/6 inhibits both cell cycle entry in human T cell acute lymphoblastic leukemia (T-ALL) and disease progression in animal models of T-ALL. These studies identify unique functions for cyclin D3:CDK4/6 complexes and suggest potential therapeutic protocols for this devastating blood tumor. PMID:23079656

  10. 2,3,4,6-Tetrachlorophenyl esters as antiseptics for fibrous materials

    SciTech Connect

    Stepanenko, N.I.; Ryakhovskaya, A.I.; Romanenko, O.A.; Garifullina, K.R.

    1983-09-10

    Wastes containing tri- and tetrachlorobenzenes are obtained during production of di- and trichlorobenzenes. One way of utilizing these wastes is conversion into di- and trichlorophenols by saponification. Chlorination of a mixture of di- and trichlorophenols converts it into 2,3,4,6-tetrachlorophenol with high yields (95-96 wt. %). The uses of tetrachlorophenol are limited by its strong specific odor and volatility. The possibility of obtaining esters of 2,3,4,6-tetrachlorophenol and saturated aliphatic C/sub 2/-C/sub 12/ monocarboxylic acids, which have good antiseptic properties in relation to fibrous materials are described.

  11. Toxicological characterization of 2,4,6-trinitrotoluene, its transformation products, and two nitramine explosives.

    PubMed

    Neuwoehner, Judith; Schofer, Andrea; Erlenkaemper, Bibiane; Steinbach, Klaus; Hund-Rinke, T Kerstin; Eisentraeger, Adolf

    2007-06-01

    The soil and groundwater of former ordnance plants and their dumping sites have often been highly contaminated with the explosive 2,4,6-trinitrotoluene (2,4,6-TNT) leading to a potential hazard for humans and the environment. Further hazards can arise from metabolites of transformation, by-products of the manufacturing process, or incomplete combustion. This work examines the toxicity of polar nitro compounds relative to their parent compound 2,4,6-TNT using four different ecotoxicological bioassays (algae growth inhibition test, daphnids immobilization test, luminescence inhibition test, and cell growth inhibition test), three genotoxicological assays (umu test, NM2009 test, and SOS Chromotest), and the Ames fluctuation test for detection of mutagenicity. For this study, substances typical for certain steps of degradation/transformation of 2,4,6-TNT were chosen for investigation. This work determines that the parent compounds 2,4,6-TNT and 1,3,5-trinitrobenzene are the most toxic substances followed by 3,5-dinitrophenol, 3,5-dinitroaniline and 4-amino-2-nitrotoluene. Less toxic are the direct degradation products of 2,4,6-TNT like 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2-amino-4,6-dinitrotoluene, and 4-amino-2,6-dinitrotoluene. A weak toxic potential was observed for 2,4,6-trinitrobenzoic acid, 2,4-diamino-6-nitrotoluene, 2,4-dinitrotoluene-5-sulfonic acid, and 2,6-diamino-4-nitrotoluene. Octahydro-l,3,5,7-tetranitro-l,3,5,7-tetrazocine and hexahydro-1,3,5-trinitro-l,3,5-triazine show no hint of acute toxicity. Based on the results of this study, we recommend expanding future monitoring programs of not only the parent substances but also potential metabolites based on conditions at the contaminated sites and to use bioassays as tools for estimating the toxicological potential directly by testing environmental samples. Site-specific protocols should be developed. If hazardous substances are found in relevant concentrations, action should be taken to prevent

  12. Oxidation of the odorous compound 2,4,6-trichloroanisole by UV activated persulfate: Kinetics, products, and pathways.

    PubMed

    Luo, Congwei; Jiang, Jin; Ma, Jun; Pang, Suyan; Liu, Yongze; Song, Yang; Guan, Chaoting; Li, Juan; Jin, Yixin; Wu, Daoji

    2016-06-01

    The transformation efficiency and products of an odorous compound 2,4,6-trichloroanisole (TCA) at the wavelength of 254 nm in the presence of persulfate were investigated for the first time. The effects of water matrix (i.e., natural organic matter (NOM), pH, carbonate/bicarbonate (HCO3(-)/CO3(2-)), and chloride ions (Cl(-))) were evaluated. The second order rate constant of TCA reacting with sulfate radical (SO4(-)) was determined to be (3.72 ± 0.10) × 10(9) M(-1) s(-1). Increasing dosage of persulfate increased the observed pseudo-first-order rate constant for TCA degradation (kobs), and the contribution of SO4(-) to TCA degradation was much higher than that of HO at each experimental condition. Degradation rate of TCA decreased with pH increasing from 4.0 to 9.0, which could be explained by the lower radical scavenging effect of dihydrogen phosphate than hydrogen phosphate in acidic condition (pH < 6). NOM significantly decreased kobs due to the effects of radical scavenging and UV absorption with the former one being dominant. kobs decreased from 2.32 × 10(-3) s(-1) to 0.92 × 10(-3) s(-1) with the CO3(2-)/HCO3(-) concentration increased from 0.5 mM to 10 mM in the UV/persulfate process, while kobs slightly decreased from 2.54 × 10(-3) s(-1) in the absence of Cl(-) to 2.10 × 10(-3) s(-1) in the presence of 10 mM Cl(-). Most of these kinetic results could be described by a steady-state kinetic model. Furthermore, liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry at powerful precursor ion scan approach was used to selectively detect oxidation products of TCA. It was found that 2,4,6-trichorophenol (TCP) was the major oxidation product (i.e., the initial yield of TCP was above 90%). The second order rate constant between TCP and SO4(-) was estimated to be (4.16 ± 0.20) × 10(9) M(-1) s(-1). In addition, three products (i.e., 2,6-dichloro-1,4-benzoquinone and two aromatic ring-opening products

  13. 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.

  14. Spectral and photophysical studies of inclusion complexes of 2-amino-4,6-dimethyl pyrimidine with beta-cyclodextrin.

    PubMed

    El-Kemary, M A; El-Gezawy, H S; El-Baradie, H Y; Issa, R M

    2002-02-01

    The interaction of 2-amino-4,6-dimethyl pyrimidine (ADMP) with beta-cyclodextrin (beta-CD) has been studied by means of UV absorption, steady state and time resolved fluorescence techniques. Spectral characteristics, bandwidths and photophysical parameters indicating that ADMP experience two different environments in aqueous solutions: bulk water and 1:1 (ADMP:beta-CD) inclusion complexation. The size restriction of the upper rim of beta-CD partially include ADMP and prevent the possibility of formation of 1:2 complex. The effective polarity of the cyclodextrin cavity experienced by the induced ADMP is equivalent with the polarity of an 80:20 methanol-water mixture.

  15. Spectral and photophysical studies of inclusion complexes of 2-amino-4,6-dimethyl pyrimidine with β-cyclodextrin

    NASA Astrophysics Data System (ADS)

    El-Kemary, M. A.; El-Gezawy, H. S.; El-Baradie, H. Y.; Issa, R. M.

    2002-02-01

    The interaction of 2-amino-4,6-dimethyl pyrimidine (ADMP) with β-cyclodextrin (β-CD) has been studied by means of UV absorption, steady state and time resolved fluorescence techniques. Spectral characteristics, bandwidths and photophysical parameters indicating that ADMP experience two different environments in aqueous solutions: bulk water and 1:1 (ADMP:β-CD) inclusion complexation. The size restriction of the upper rim of β-CD partially include ADMP and prevent the possibility of formation of 1:2 complex. The effective polarity of the cyclodextrin cavity experienced by the induced ADMP is equivalent with the polarity of an 80:20 methanol-water mixture.

  16. A structure-activity study on the sucrose taste antagonist methyl 4,6-dichloro-4,6-dideoxy-alpha-D-galactopyranoside.

    PubMed

    Vlahopoulos, V; Jakinovich, W

    1986-09-01

    In order to assess the effect of the antagonist methyl 4,6-dichloro-4,6-dideoxy-alpha-D-galactopyranoside (MAD-diCl-Gal) upon the gerbil's chorda tympani sucrose taste response, we tested several concentrations of this compound, as well as single concentrations of closely related derivatives, and found that MAD-diCl-Gal was the most potent inhibitor tested. It appears that the inhibition mechanism is very specific. For example, we have found that 2 chlorine atoms at the C-4 and C-6 positions on the glucopyranoside ring are required for inhibition. In addition, with regard to the orientation of the chlorine atoms, the galacto derivative seems to be more potent than the gluco derivative. We have also found that the methyl glycoside is more potent than the free sugar. With regard to the orientation of the methyl group, MAD-diCl-Gal is more potent than its beta-anomer. (Because of this discovery of the methyl group enhancement and orientation effect, we shall discontinue using the acronym diCl-Gal and replace it with the more specific MAD-diCl-Gal.) Of particular significance is the fact that there appears to be a structure-activity relationship between the most active stimulants and inhibitors in that the requirement for an axial orientation at C-1 and the enhancement by the methyl group at that position are the same in both cases. These results suggest that both the stimulator and the antagonist are acting at the same receptor site.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3746425

  17. Biotransformation of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) by denitrifying Pseudomonas sp. strain FA1.

    PubMed

    Bhushan, Bharat; Paquet, Louise; Spain, Jim C; Hawari, Jalal

    2003-09-01

    The microbial and enzymatic degradation of a new energetic compound, 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), is not well understood. Fundamental knowledge about the mechanism of microbial degradation of CL-20 is essential to allow the prediction of its fate in the environment. In the present study, a CL-20-degrading denitrifying strain capable of utilizing CL-20 as the sole nitrogen source, Pseudomonas sp. strain FA1, was isolated from a garden soil. Studies with intact cells showed that aerobic conditions were required for bacterial growth and that anaerobic conditions enhanced CL-20 biotransformation. An enzyme(s) involved in the initial biotransformation of CL-20 was shown to be membrane associated and NADH dependent, and its expression was up-regulated about 2.2-fold in CL-20-induced cells. The rates of CL-20 biotransformation by the resting cells and the membrane-enzyme preparation were 3.2 +/- 0.1 nmol h(-1) mg of cell biomass(-1) and 11.5 +/- 0.4 nmol h(-1) mg of protein(-1), respectively, under anaerobic conditions. In the membrane-enzyme-catalyzed reactions, 2.3 nitrite ions (NO(2)(-)), 1.5 molecules of nitrous oxide (N(2)O), and 1.7 molecules of formic acid (HCOOH) were produced per reacted CL-20 molecule. The membrane-enzyme preparation reduced nitrite to nitrous oxide under anaerobic conditions. A comparative study of native enzymes, deflavoenzymes, and a reconstituted enzyme(s) and their subsequent inhibition by diphenyliodonium revealed that biotransformation of CL-20 is catalyzed by a membrane-associated flavoenzyme. The latter catalyzed an oxygen-sensitive one-electron transfer reaction that caused initial N denitration of CL-20. PMID:12957905

  18. Biotransformation of 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-Hexaazaisowurtzitane (CL-20) by Denitrifying Pseudomonas sp. Strain FA1

    PubMed Central

    Bhushan, Bharat; Paquet, Louise; Spain, Jim C.; Hawari, Jalal

    2003-01-01

    The microbial and enzymatic degradation of a new energetic compound, 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), is not well understood. Fundamental knowledge about the mechanism of microbial degradation of CL-20 is essential to allow the prediction of its fate in the environment. In the present study, a CL-20-degrading denitrifying strain capable of utilizing CL-20 as the sole nitrogen source, Pseudomonas sp. strain FA1, was isolated from a garden soil. Studies with intact cells showed that aerobic conditions were required for bacterial growth and that anaerobic conditions enhanced CL-20 biotransformation. An enzyme(s) involved in the initial biotransformation of CL-20 was shown to be membrane associated and NADH dependent, and its expression was up-regulated about 2.2-fold in CL-20-induced cells. The rates of CL-20 biotransformation by the resting cells and the membrane-enzyme preparation were 3.2 ± 0.1 nmol h−1 mg of cell biomass−1 and 11.5 ± 0.4 nmol h−1 mg of protein−1, respectively, under anaerobic conditions. In the membrane-enzyme-catalyzed reactions, 2.3 nitrite ions (NO2−), 1.5 molecules of nitrous oxide (N2O), and 1.7 molecules of formic acid (HCOOH) were produced per reacted CL-20 molecule. The membrane-enzyme preparation reduced nitrite to nitrous oxide under anaerobic conditions. A comparative study of native enzymes, deflavoenzymes, and a reconstituted enzyme(s) and their subsequent inhibition by diphenyliodonium revealed that biotransformation of CL-20 is catalyzed by a membrane-associated flavoenzyme. The latter catalyzed an oxygen-sensitive one-electron transfer reaction that caused initial N denitration of CL-20. PMID:12957905

  19. Planet Patrol. An Environmental Unit on Solid Waste Solutions for Grades 4-6.

    ERIC Educational Resources Information Center

    Procter and Gamble Educational Services, Cincinnati, OH.

    This classroom unit was developed for use in grades 4-6 to help teach the concept of solid waste management. The teacher's guide provides an overview of the issue of solid waste disposal, a description of government, industry, and consumer roles in resolving the solid waste issue, and four lessons involving sanitary landfills, the reduction of…

  20. PCE/K-10 Activities for Career Education, Grades 4-6.

    ERIC Educational Resources Information Center

    Portland Public Schools, OR. Area II Office.

    The Portland (Oregon) Public School Project Career Education (PCE) Activities for grades 4-6 is based on the city's overall Area 2 program goals for career education which proposed that children completing school should have sufficient knowledge and competencies to enter into a field of employment or an advanced training program in that field.…

  1. BIOTRANSFORMATION OF 2,4,6-TRINITROTOLUENE (TNT) BY A PLANT-ASSOCIATED FUNGUS FUSARIUM OXYSPORUM

    EPA Science Inventory

    The capability of a plant-associated fungus, Fusarium oxyvorum, to transform TNT in liquid cultures was investigated. TNT was transformed into 2-amino-4, 6-dinitrotoluene (2-A-DNT), 4-amino-2, 6-dinitrotoluene (4-A- DNT), and 2, 4-diamino-6-nitrotoluene (2, 4-DAT) via 2- and 4-hy...

  2. Federal Aviation Administration Aviation Education Teacher's Guide, [Grades] 4-6.

    ERIC Educational Resources Information Center

    Federal Aviation Administration (DOT), Washington, DC.

    This guide is one in a series of four resource guides specifically designed for those interested in aviation education. Activities and lessons that can be used in a variety of content areas and grade levels are featured. Grades 4-6 are the focus of this guide, which is organized under the broad topics of properties of air, lighter than air flight,…

  3. A Curriculum in Written Composition, 4-6: A Guide for Teaching.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. English Curriculum Study Center.

    This guide for teaching composition in grades 4-6 (1) objectives for a curriculum in written composition, (2) sequence charts which relate subject content for each grade to basic understandings about composition, (3) illustrative learning experiences, and (4) units for teaching specific skills. The units for each grade are "Structuring a…

  4. Isopropyl 2,3,4,6-tetra-O-acetyl-β-d-glucopyran­oside

    PubMed Central

    Mönch, Bettina; Emmerling, Franziska; Kraus, Werner; Becker, Roland; Nehls, Irene

    2013-01-01

    The title compound, C17H26O10, was formed by a Koenigs–Knorr reaction of 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl bromide and propan-2-ol. The central ring adopts a chair conformation. The crystal does not contain any significant inter­molecular inter­actions. PMID:23424447

  5. Teaching Writing in Grades 4-6 in Urban Schools in the Greater China Region

    ERIC Educational Resources Information Center

    Hsiang, Tien Ping; Graham, Steve

    2016-01-01

    A random sample of 1102 grade 4-6 Chinese language arts teachers in Beijing, Macao, and Taipei City were surveyed about their instructional writing practices. Seventy-eight percent (n = 857) of the teachers completed the survey. Teachers were generally positive about the usefulness of their college teacher preparation program. They slightly agreed…

  6. The Synthesis of 4,6,8-Trimethylazulene: An Organic Laboratory Experiment.

    ERIC Educational Resources Information Center

    Garst, Michael E.; And Others

    1983-01-01

    A two-stage synthesis of 4,6,8-trimethylazulene was developed for use in the undergraduate experiment, highlighting concepts not usually covered in the laboratory. The experiment requires purification procedures of chromatography and of sublimation and illustrates concepts of aromaticity, molecular orbital theory, and carbodium ion reactivity. (JN)

  7. 26 CFR 1.401(a)(4)-6 - Contributory defined benefit plans.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... § 1.401(a)(4)-6 Contributory defined benefit plans. (a) Introduction. This section provides rules... of § 1.401(a)(4)-1(b)(2). Paragraph (b) of this section provides rules for determining the amount of.... Paragraph (c) of this section provides the exclusive rules for determining whether a contributory DB...

  8. The Greatest Educational Change America Has Ever Seen, 2002: Lesson Plans for Grades 4-6.

    ERIC Educational Resources Information Center

    United States Mint (Dept. of Treasury), Washington, DC.

    This teacher's guide on the 50 state quarters emitted by the United States Mint includes 6 "teacher-friendly" lesson plans that fit easily into the curriculum for grades 4-6; reproducible student worksheets that coincide with each lesson; "fun" state facts and information on the new quarter designs; and USA map template with state outlines. These…

  9. The Greatest Educational Change America Has Ever Seen. [Teaching Guide]. Grades 4-6.

    ERIC Educational Resources Information Center

    United States Mint (Dept. of Treasury), Washington, DC.

    This teaching guide for grades 4-6 focuses on the 1999-2000 United States Mint 50 State Quarters Program, which includes new quarter designs for the following states: Delaware, Pennsylvania, New Jersey, Georgia, Connecticut, Massachusetts, Maryland, South Carolina, New Hampshire, and Virginia. The guide includes six lesson plans that fit easily…

  10. The Greatest Educational Change America Has Ever Seen, 2001: Lesson Plans for Grades 4-6.

    ERIC Educational Resources Information Center

    United States Mint (Dept. of Treasury), Washington, DC.

    This teacher's guide on the 50 state quarters produced by the United States Mint includes six lesson plans that fit easily into the social studies curriculum for grades 4-6. The lesson plans include reproducible student work pages that coincide with each lesson; state facts and information about the 2001 state quarter designs (New York, North…

  11. The Navajo Way of Life: A Resource Unit with Activities for Grades 4-6.

    ERIC Educational Resources Information Center

    Cordova, Dahlia

    A resource unit on the Navajo way of life, for grades 4-6, contains sections on Navajo history, art, and crafts, homes, music, poetry and games; Navajo and Pueblo cookery (including recipes); traditional Navajo dress, ceremony and legends; and successful Navajos, past and present. Sections include text, vocabulary words, drawings, maps, and…

  12. 43 CFR 2650.4-6 - National wildlife refuge system lands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false National wildlife refuge system lands... SELECTIONS Alaska Native Selections: Generally § 2650.4-6 National wildlife refuge system lands. (a) Every conveyance which includes lands within the national wildlife refuge system shall, as to such lands,...

  13. 43 CFR 2650.4-6 - National wildlife refuge system lands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false National wildlife refuge system lands... SELECTIONS Alaska Native Selections: Generally § 2650.4-6 National wildlife refuge system lands. (a) Every conveyance which includes lands within the national wildlife refuge system shall, as to such lands,...

  14. 43 CFR 2650.4-6 - National wildlife refuge system lands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false National wildlife refuge system lands... SELECTIONS Alaska Native Selections: Generally § 2650.4-6 National wildlife refuge system lands. (a) Every conveyance which includes lands within the national wildlife refuge system shall, as to such lands,...

  15. 43 CFR 2650.4-6 - National wildlife refuge system lands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false National wildlife refuge system lands... SELECTIONS Alaska Native Selections: Generally § 2650.4-6 National wildlife refuge system lands. (a) Every conveyance which includes lands within the national wildlife refuge system shall, as to such lands,...

  16. Toxics in My Home? You Bet! Curriculum on Household Toxics for Grades 4-6.

    ERIC Educational Resources Information Center

    Purin, Gina; And Others

    This curriculum consists of a one-week course of study designed to introduce students in grades 4-6 to (or increase their awareness of) toxic substances commonly found in the home. It includes an introduction/conceptual framework, four lessons, a unit evaluation, and appendices. Each lesson consists of a statement of purpose, objectives,…

  17. Explorations in Backyard Biology: Drawing on Nature in the Classroom, Grades 4-6.

    ERIC Educational Resources Information Center

    Raham, R. Gary

    This book is designed to guide students grades 4-6 in exploring new worlds of adventure in the life sciences. Students read short features on creatures as near as their own backyards, are invited to expand their interest with classroom and field activities, and are shown how to use drawing and writing skills to record their experiences in a…

  18. Kids, Crops, & Critters in the Classroom: An Agricultural Literacy Resource Guide for Grades 4-6.

    ERIC Educational Resources Information Center

    Illinois Farm Bureau, Bloomington.

    This resource guide provides teachers of grades 4-6 with ideas and materials to integrate agricultural concepts into classroom activities. The guide is organized into six categories: math, science, language arts, social studies, fine arts, and health/nutrition/safety. Each category contains 10 lessons organized in the following topic order:…

  19. Absorption, balance and metabolism of /sup 14/C-2, 4, 6-trichlorophenol in hydroponic tomato plants

    SciTech Connect

    Fragiadakis, A.; Sotiriou, N.; Korte, F.

    1981-12-01

    Most of the 2, 4, 6-TCP applied in the nutrient solution of the hydroculture test was volatilised; a proportion was absorbed by the developed plant roots and to a small extent isomerised. Significant portions of the non-extractable tomato plant residues were found in the isolated lignin and cellulose fractions.

  20. Teaching New Literacies in Grades 4-6: Resources for 21st-Century Classrooms

    ERIC Educational Resources Information Center

    Moss, Barbara, Ed.; Lapp, Diane, Ed.

    2009-01-01

    Upper-elementary students encounter a sometimes dizzying array of traditional and nontraditional texts both in and outside of the classroom. This practical handbook helps teachers in grades 4-6 harness the instructional potential of fiction, poetry, and plays; informational texts; graphic novels; digital storytelling; Web-based and multimodal…

  1. Living in Water. An Aquatic Science Curriculum for Grades 4-6. Second Edition.

    ERIC Educational Resources Information Center

    National Aquarium in Baltimore, MD. Dept. of Education.

    This document is a scientific study of water, aquatic environments and the plants and animals that live in water. It was written for grades 4-6 but many activities may also be of interest for use with older students. This curriculum covers both marine and freshwater habitats. Each of five sections addresses a question about water which is then…

  2. SAGE ANALYSIS OF TRANSCRIPTOME RESPONSES IN ARABIDOPSIS ROOTS EXPOSED TO 2,4,6-TRINITROTOLUENE

    EPA Science Inventory

    Serial Analysis of Gene Expression (SAGE) was used to profile transcript levels in Arabidopsis thaliana roots and assess their responses to 2,4,6-trinitrotoluene (TNT) exposure. SAGE libraries representing control and TNT-exposed seedling root transcripts were constructed, and ea...

  3. TOXICITY OF TETRYL (N-METHYL-N,2,4,6-TETRANITROANILINE) IN F344 RATS

    EPA Science Inventory

    The toxicity of tetryl (N-methyl-N,2,4,6-tetranitroaniline) in male and female F344 rats was evaluated after adminstration in the diet for 14 or 90 days. The 14-day study diet concentrations used were 0, 500, 1250, 2000, 2500, and 5000 ppm; the 90-day study diet concentrations we...

  4. Preparation of 1,3,5-triamo-2,4,6-trinitrobenzene of submicron particle size

    DOEpatents

    Rigdon, Lester P.; Moody, Gordon L.; McGuire, Raymond R.

    2001-05-01

    A method is disclosed for the preparation of very small particle size, relatively pure 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). Particles of TATB prepared according to the disclosed method are of submicron size and have a surface area in the range from about 3.8 to 27 square meters per gram.

  5. Preparation of 1,3,5-triamino-2,4,6-trinitrobenzene of submicron particle size

    DOEpatents

    Rigdon, Lester P.; Moody, Gordon L.; McGuire, Raymond R.

    2001-01-01

    A method is disclosed for the preparation of very small particle size, relatively pure 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). Particles of TATB prepared according to the disclosed method are of submicron size and have a surface area in the range from about 3.8 to 27 square meters per gram.

  6. Conserve & Renew. An Energy Education Activity Package for Grades 4-6.

    ERIC Educational Resources Information Center

    Tourtillot, Leeann

    This teaching guide contains a collection of energy education activities written and organized so that they might be used either as a unit on energy, or as individual activities to complement existing curricula in grades 4-6. The focus in on conservation and renewables. Most of 23 activities are designed as cooperative learning experiences and are…

  7. The Uncomplicated Elementary Career Education System for the "Real" Classroom. Career Capers for 4-6.

    ERIC Educational Resources Information Center

    Illinois State Office of Education, Springfield. Div. of Adult Vocational and Technical Education.

    Prepared by classroom teachers for the infusion of career education into existing curriculum, this notebook of student and teacher activities is designed for use with the monthly Factivities for grades 4-6 (CE 023 596). Each activity corresponds to one of the nine monthly topics: "me, myself, and I"; exploring the telephone book; transportation;…

  8. SOIL REDUCES 2,4,6-TRINITROTOLUENE BIOAVAILABILITY AND GENOTOXICITY IN VIVO

    EPA Science Inventory

    Soil Reduces 2,4,6- Trinitrotoluene Bioavailability and Genotoxicity In Vivo

    As chemicals age in soil, irreversible binding of chemical contaminants to organic components in the soil may occur, impacting the amount of chemical that is biologically available upon exp...

  9. Microbial transformation of 2,4,6-trinitrotoluene in aerobic soil columns

    SciTech Connect

    Bruns-Nagel, D.; Breitung, J.; Loew, E. von

    1996-07-01

    The explosive 2,4,6-trinitrotoluene (TNT) is a common contaminant of soil and groundwater at former muntion plants and their dumping sites. TNT is toxic to numerous organisms. This paper reports on an efficient aerobic circulating percolation reactor system for the microbial detoxification of TNT-contaminated soil. 36 refs., 4 figs., 1 tab.

  10. 42 CFR 4.6 - Reference, bibliographic, reproduction, and consultation services.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Reference, bibliographic, reproduction, and... SERVICES GENERAL PROVISIONS NATIONAL LIBRARY OF MEDICINE § 4.6 Reference, bibliographic, reproduction, and... request, reference, bibliographic, reproduction, and consultation services. Priority will be given...

  11. 42 CFR 4.6 - Reference, bibliographic, reproduction, and consultation services.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Reference, bibliographic, reproduction, and... SERVICES GENERAL PROVISIONS NATIONAL LIBRARY OF MEDICINE § 4.6 Reference, bibliographic, reproduction, and... request, reference, bibliographic, reproduction, and consultation services. Priority will be given...

  12. 42 CFR 4.6 - Reference, bibliographic, reproduction, and consultation services.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Reference, bibliographic, reproduction, and... SERVICES GENERAL PROVISIONS NATIONAL LIBRARY OF MEDICINE § 4.6 Reference, bibliographic, reproduction, and... request, reference, bibliographic, reproduction, and consultation services. Priority will be given...

  13. 42 CFR 4.6 - Reference, bibliographic, reproduction, and consultation services.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Reference, bibliographic, reproduction, and... SERVICES GENERAL PROVISIONS NATIONAL LIBRARY OF MEDICINE § 4.6 Reference, bibliographic, reproduction, and... request, reference, bibliographic, reproduction, and consultation services. Priority will be given...

  14. 42 CFR 4.6 - Reference, bibliographic, reproduction, and consultation services.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Reference, bibliographic, reproduction, and... SERVICES GENERAL PROVISIONS NATIONAL LIBRARY OF MEDICINE § 4.6 Reference, bibliographic, reproduction, and... request, reference, bibliographic, reproduction, and consultation services. Priority will be given...

  15. Texas School Survey of Substance Use among Students: Grades 4-6, 1998.

    ERIC Educational Resources Information Center

    Wallisch, Lynn S.; Liu, Liang Y.

    This booklet reports on the results of the 1998 Texas School Survey of Substance Use among Students: Grades 4-6. The statewide school survey monitors trends in substance use among public school students, identifies emerging problem areas, and serves as a basis of comparison for local school surveys which are conducted annually by various school…

  16. Synthesis and properties of radiopaque polymer hydrogels II: copolymers of 2,4,6-triiodophenyl- or N-(3-carboxy-2,4,6-triiodophenyl)- acrylamide and p-styrene sulfonate

    NASA Astrophysics Data System (ADS)

    Okamura, Masahiko; Yamanobe, Takeshi; Arai, Tomohiro; Uehara, Hiroki; Komoto, Tadashi; Hosoi, Seiichi; Kumazaki, Tatsuo

    2002-01-01

    In order to pursue a possibility of application of radiopaque polymer hydrogels to vascular embolization, studies were made on synthesis of iodine containing copolyanions and properties of their hydrogels with polycation via formation of polyion complexes (PIC). Acrylamide derivatives having triiodophenyl groups were synthesized and copolymerized with sodium styrene sulfonate (SS) under several conditions. It was found that N-(3-carboxy-2,4,6-triiodophenyl)-acrylamide (CIPA) and 2,4,6-triiodophenylacrylamide (TIPA) monomers are effectively copolymerized with SS, while N-allyl-2,3,5-triiodobenzamide (ATIBA) are hardly copolymerized. Hydrogels were prepared by mixing aqueous solutions of polyanions, i.e. the copolymers (PCIPA and PTIPA) and polyallylamine (PAAn). 13C NMR spectra of PCIPA/PAAn and PTIPA/PAAn hydrogels gave peaks for both polyanion and polycation. This means that there remained free anionic and cationic monomer units, which did not form ion pairs because of spatial hindrance. Time dependence of 1H T2 showed quick increment and plateau for PSS/PAAn and gradual increments for PCIPA/PAAn. Therefore, PIC containing the radiopaque copolymer retains the hydrogel state for a long time. Embolization was examined by injection of PCIPA/PAAn hydrogels into the vein of a removed porcine kidney as a preliminary test for transcatheter arterial embolization (TAE). X-ray radiograms of the embolized organ were reasonably explained based on the structure and mobility of hydrogels.

  17. 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…

  18. 17 CFR 4.6 - Exclusion for certain otherwise regulated persons from the definition of the term “commodity...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... otherwise regulated persons from the definition of the term âcommodity trading advisor.â 4.6 Section 4.6 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION COMMODITY POOL OPERATORS AND COMMODITY TRADING ADVISORS General Provisions, Definitions and Exemptions § 4.6 Exclusion for...

  19. Chemical studies of L chondrites. V: compositional patterns for 49 trace elements in 14 L4-6 and 7 LL4-6 falls

    NASA Astrophysics Data System (ADS)

    Friedrich, Jon M.; Wang, Ming-Sheng; Lipschutz, Michael E.

    2003-07-01

    To study compositional trends associated with open-system thermal metamorphism and shock-induced collisional breakup of L4-6 chondrite parent(s), we used inductively coupled plasma mass spectrometry and radiochemical neutron activation analysis to determine 49 trace elements in 62 falls. Trends for the 49 elements, especially of the 14 rare earth elements in 5 members of a putative L/LL group (Bjurböle, Cynthiana, Holbrook, Knyahinya, Sultanpur) and 9 additional L chondrites (Aïr, Aumieres, Bachmut, Forksville, Kandahar, Kiel, Milean, Narellan, Santa Isabel) differed markedly from those in the remaining normal 46 samples. Here, we report the data for the 14 L and putative L/LL chondrites and 7 LL (Appley Bridge, Athens, Bandong, Ensisheim, Mangwendi, Olivenza, Soko-Banja), analyzed to test the affinity of the putative L/LL suite to well-characterized LL chondrites. Compositional trends of the 14 atypical L chondrites (including Aïr's unique and possibly contaminated signature) and Mangwendi, an LL6 chondrite, indicate that each is compositionally unrepresentative of well-sampled, whole-rock chondrites. Indeed, half of the unrepresentative chondrites were ≤ 2-g samples. Compositionally, members of the putative L/LL chondrites demonstrate no affinities to normal LL chondrite falls. To establish compositional trends accompanying open-system, thermal episodes involving the L chondrite parent(s), we should ignore data for the 14 unrepresentative L chondrites reported here.

  20. 2,4,6-Triarylphosphinines versus 2,4,6-triarylpyridines: an investigation of the differences in reactivity between structurally related aromatic phosphorus and nitrogen heterocycles.

    PubMed

    Weemers, Jarno J M; Wiecko, Jelena; Pidko, Evgeny A; Weber, Manuela; Lutz, Martin; Müller, Christian

    2013-10-18

    The novel atropisomeric pyridine derivative rac-10 has been synthesized and structurally characterized. In contrast to its phosphorus analogue 3, axially chiral 10 has a considerably lower rotational barrier as estimated by DFT calculations. However, the presence of the two enantiomers could be confirmed by means of chiral analytical HPLC analysis and by protonation experiments with a chiral acid. Compound rac-10 could be further dehydrogenated by treatment with DDQ to the benzo(h)quinoline derivative rac-12. This conversion failed for the phosphorus analogue rac-3. Interestingly, although 2,4,6-triarylphosphinines undergo facile CH activation with [Cp*IrCl2 ]2 in the presence of NaOAc, this reaction does not proceed with the corresponding pyridine derivatives. On the other hand, the latter ones can be selectively ortho-metalated with Pd(OAc)2 , leading to acetate-bridged dimeric species, which could be unambiguously confirmed by means of X-ray crystal structure analysis. The treatment of phosphinines with Pd(OAc)2 led instead to the formation of the unusual cofacial oxidative coupling products 16 and 17, which consist of a phosphorus-containing cage structure. PMID:24123238

  1. Multiple Roles of Cyclin-Dependent Kinase 4/6 Inhibitors in Cancer Therapy

    PubMed Central

    Roberts, Patrick J.; Bisi, John E.; Strum, Jay C.; Combest, Austin J.; Darr, David B.; Usary, Jerry E.; Zamboni, William C.; Wong, Kwok-Kin; Perou, Charles M.

    2012-01-01

    Background Cyclin-dependent kinases (CDKs) regulate cell proliferation and coordinate the cell cycle checkpoint response to DNA damage. Although inhibitors with varying selectivity to specific CDK family members have been developed, selective CDK4/6 inhibitors have emerged as the most attractive antineoplastic agents because of the importance of CDK4/6 activity in regulating cell proliferation and the toxic effects associated with inhibition of other CDKs (eg, CDK1 and CDK2). Methods FVB/N wild-type mice (n = 13) were used to evaluate carboplatin-induced myelosuppression in bone marrow by complete blood cell counts after treatment with the CDK4/6 inhibitor PD0332991. Genetically engineered murine models of retinoblastoma (Rb)-competent (MMTV-c-neu) and Rb-incompetent (C3-TAg) breast cancer (n = 16 MMTV-c-neu mice in the carboplatin plus vehicle control group, n = 17 MMTV-c-neu mice in the carboplatin plus PD0332991 group, n = 17 C3-TAg mice in the carboplatin plus vehicle control group, and n = 14 C3-TAg mice in the carboplatin plus PD0332991 group) were used to investigate the antitumor activity of PD0332991 alone or in combination with chemotherapy. All statistical tests were two-sided. Results Coadministration of PD0332991 with carboplatin compared with carboplatin alone in FVB/N wild-type mice increased hematocrit (51.2% vs 33.5%, difference = 17.7%, 95% confidence interval [CI] = −26.7% to −8.6%, P < .001), platelet counts (1321 vs 758.5 thousand cells per μL, difference = 562.5 thousand cells per μL, 95% CI = −902.8 to −222.6, P = .002), myeloid cells (granulocytes and monocytes; 3.1 vs 1.6 thousand cells per μL, difference = 1.5 thousand cells per μL, 95% CI = −2.23 to −0.67, P < .001), and lymphocytes (7.9 vs 5.4 thousand cells per μL, difference = 2.5 thousand cells per μL, 95% CI = −4.75 to −0.18, P = .02). Daily administration of PD0332991 exhibited antitumor activity in MMTV-c-neu mice as a single agent. However, the combination of

  2. 2-Anilino-4,6-dimethyl­pyrimidinium chloro­acetate

    PubMed Central

    Li, Jia-Cheng; Qiu, Xue-Qing; Feng, Yu-Hong; Lin, Qiang

    2008-01-01

    In the crystal structure of the title compound, C12H14N3 +·C2H2ClO2 −, the chloro­acetate anion is linked to the N-(4,6-dimethyl­pyrimidin-2-yl)aniline cation by N—H⋯O hydrogen bonding. Within the cation, the pyrimidine ring is twisted with respect to the phenyl ring by a dihedral angle of 7.59 (4)°. PMID:21200879

  3. Reflectance spectra of mafic silicates and phyllosilicates from .6 to 4.6 microns

    NASA Technical Reports Server (NTRS)

    Roush, Ted L.; Singer, Robert B.; Mccord, Thomas B.

    1987-01-01

    The results of spectral measurements for mafic silicates are given. The study provided valuable spectral reflectance information about mafic silicates and phyllosilicates in the 2.5 to 4.6 micron wavelength region. It was shown that the reflectance of these materials is strongly affected by the presence of H2O and OH. Therefore, the identification of these absorbing species is greatly enhanced.

  4. Spot test for 1,3,5-triamino-2,4,6-trinitrobenzene, TATB

    DOEpatents

    Harris, Betty W.

    1986-01-01

    A simple, sensitive and specific spot test for 1,3,5-triamino-2,4,6-trinitrobenzene, TATB, is described. Upon the application of the composition of matter of the present invention to samples containing in excess of 0.1 mg of this explosive, a bright orange color results. Interfering species such as TNT and Tetryl can be removed by first treating the sample with a solvent which does not dissolve much of the TATB, but readily dissolves these explosives.

  5. Spot test for 1,3,5-triamino-2,4,6-trinitrobenzene, TATB

    DOEpatents

    Harris, B.W.

    1984-11-29

    A simple, sensitive and specific spot test for 1,3,5-triamino-2,4,6-trinitrobenzene, TATB, is described. Upon the application of the composition of matter of the subject invention to samples containing in excess of 0.1 mg of this explosive, a bright orange color results. Interfering species such as TNT and Tetryl can be removed by first treating the sample with a solvent which does not dissolve the TATB, but readily dissolves these interfering explosives.

  6. New double molybdate Na9Fe(MoO4)6: Synthesis, structure, properties

    NASA Astrophysics Data System (ADS)

    Savina, Aleksandra A.; Solodovnikov, Sergey F.; Basovich, Olga M.; Solodovnikova, Zoya A.; Belov, Dmitry A.; Pokholok, Konstantin V.; Gudkova, Irina A.; Stefanovich, Sergey Yu.; Lazoryak, Bogdan I.; Khaikina, Elena G.

    2013-09-01

    A new double molybdate Na9Fe(MoO4)6 was synthesized using solid state reactions and studied with X-ray powder diffraction, second harmonic generation (SHG) technique, differential scanning calorimetry, X-ray fluorescence analysis, Mössbauer and dielectric impedance spectroscopy. Single crystals of Na9Fe(MoO4)6 were obtained and its structure was solved (the space group R3¯, a=14.8264(2), c=19.2402(3) Å, V=3662.79(9) Å3, Z=6, R=0.0132). The structure is related to that of sodium ion conductor II-Na3Fe2(AsO4)3. The basic structure units are polyhedral clusters composed of central FeО6 octahedron sharing edges with three Na(1)О6 octahedra. The clusters share common vertices with bridging МоО4 tetrahedra to form an open 3D framework where the cavities are occupied by Na(2) and Na(3) atoms. The compound melts incongruently at 904.7±0.2 K. Arrhenius type temperature dependence of electric conductivity σ has been registered in solid state (σ=6.8×10-2 S сm-1 at 800 K), thus allowing considering Na9Fe(MoO4)6 as a new sodium ion conductor.

  7. Pharmacologic inhibition of cdk4/6 arrests the growth of glioblastoma multiforme intracranial xenografts

    PubMed Central

    Michaud, Karine; Solomon, David A.; Oermann, Eric; Kim, Jung-Sik; Zhong, Wei-Zhu; Prados, Michael D.; Ozawa, Tomoko; James, C. David; Waldman, Todd

    2010-01-01

    Activation of cyclin-dependent kinases 4 and 6 (cdk4/6) occurs in the majority of glioblastoma multiforme (GBM) tumors, and represents a promising molecular target for the development of small molecule inhibitors. In the current study we investigated the molecular determinants and in vivo response of diverse GBM cell lines and xenografts to PD-0332991, a cdk4/6 specific inhibitor. In vitro testing of PD-0332991 against a panel of GBM cell lines revealed a potent G1 cell cycle arrest and induction of senescence in each of 16 Rb-proficient cell lines regardless of other genetic lesions, whereas each of 5 cell lines with homozygous inactivation of Rb were completely resistant to treatment. shRNA depletion of Rb expression conferred resistance of GBM cells to PD-0332991, further demonstrating a requirement of Rb for sensitivity to cdk4/6 inhibition. PD-0332991 was found to efficiently cross the blood-brain barrier and proved highly effective in suppressing the growth of intracranial GBM xenograft tumors, including those that had recurred after initial therapy with temozolomide. Remarkably, no mice receiving PD-0332991 had significant disease progression or died while on therapy. Additionally, the combination of PD-0332991 and radiation therapy resulted in significantly increased survival benefit compared with either therapy alone. In total, our results support clinical trial evaluation of PD-0332991 against newly-diagnosed as well as recurrent GBM, and indicate that Rb status is the primary determinant of potential benefit from this therapy. PMID:20354191

  8. Potential of activated carbon to decrease 2,4,6-trinitrotoluene toxicity and accelerate soil decontamination.

    PubMed

    Vasilyeva, G K; Kreslavski, V D; Oh, B T; Shea, P J

    2001-05-01

    Activated carbon can be used to decrease 2,4,6-trinitrotoluene (TNT) toxicity and promote bioremediation of highly contaminated soil. Adding activated carbon at 0.25, 0.75, and 1.0% (w/w) to Sharpsburg soil contaminated with 500, 1,000, and 2,000 mg TNT/kg decreased concentrations of TNT and its transformation products in soil solution to 5 mg/L or less, resulting in low toxicity to corn plants (Zea mays L.) and soil microorganisms. As much as 50% of the added TNT was rapidly bound to the soil-activated carbon matrix. Simultaneous accumulation of 2,4,6-trinitrobenzaldehyde (TNBAld) indicated that the activated carbon promoted oxidation of TNT. Some of the TNBAld was further oxidized to 1,3,5-trinitrobenzene, followed by reduction to 3,5-dinitroaniline. Reversibly bound TNT was gradually transformed to 2-amino-4,6-dinitrotoluene and 4-amino-2,6-dinitrotoluene, and both were bound to the soil-activated carbon matrix. The transformation and binding of TNT to soil were further promoted by incorporating shredded corn plants after growing for 52 d in the activated carbon-amended soil. After 120 d, these amendments reduced extractable TNT and transformation products by 91% in soil containing 2,000 mg TNT/kg, compared to 55% in unamended soil. These results demonstrate the potential use of activated carbon in combination with plants to promote in situ bioremediation of soils highly contaminated with explosives.

  9. p18 inhibits reprogramming through inactivation of Cdk4/6

    PubMed Central

    Zhu, Shaohua; Cao, Jiani; Sun, Hongyan; Liu, Kun; Li, Yaqiong; Zhao, Tongbiao

    2016-01-01

    Pluripotent stem cells (PSCs), including embryonic and induced pluripotent stem cells (iPSCs), show atypical cell cycle regulation characterized by a high proliferation rate and a shorter G1 phase compared with somatic cells. The mechanisms by which somatic cells remodel their cell cycle to achieve the high proliferation rate of PSCs during reprogramming are unclear. Here we identify that the Ink4 protein p18, which is expressed at high levels in somatic cells but at low levels in PSCs, is a roadblock to successful reprogramming. Mild inhibition of p18 expression enhances reprogramming efficiency, while ectopic expression of p18 completely blocks reprogramming. Mechanistic studies show that expression of wild-type p18, but not a p18D68N mutant which cannot inhibit Cdk4/6, down-regulates expression of Cdk4/6 target genes involved in DNA synthesis (TK, TS, DHFR, PCNA) and cell cycle regulation (CDK1 and CCNA2) and thus inhibits reprogramming. These results indicate that p18 blocks reprogramming by targeting Cdk4/6-mediated cell cycle regulation. Taken together, our results define a novel pathway that inhibits somatic cell reprogramming, and provide a new target to enhance reprogramming efficiency. PMID:27484146

  10. 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…

  11. Broadband Yellowish-Green Emitting Ba4Gd3Na3(PO4)6F2:Eu(2+) Phosphor: Structure Refinement, Energy Transfer, and Thermal Stability.

    PubMed

    Fu, Xiaopeng; Lü, Wei; Jiao, Mengmeng; You, Hongpeng

    2016-06-20

    A series of Ba4Gd3Na3(PO4)6F2:Eu(2+) phosphors with a broad emitting band have been synthesized by a traditional solid state reaction. The crystal structural and photoluminescence properties of Ba4Gd3Na3(PO4)6F2:Eu(2+) are investigated. The different crystallographic sites of Eu(2+) in Ba4Gd3Na3(PO4)6F2:Eu(2+) phosphors have been verified by means of their photoluminescence (PL) properties and decay times. Energy transfer between Eu(2+) ions, analyzed by excitation, emission, and PL decay behavior, has been indicated to be a dipole-dipole mechanism. Moreover, the luminescence quantum yield as well as the thermal stability of the Ba4Gd3Na3(PO4)6F2:Eu(2+) phosphor have been investigated systematically. The as-prepared Ba4Gd3Na3(PO4)6F2:Eu(2+) phosphor can act as a promising candidate for n-UV convertible white LEDs. PMID:27249557

  12. Broadband Yellowish-Green Emitting Ba4Gd3Na3(PO4)6F2:Eu(2+) Phosphor: Structure Refinement, Energy Transfer, and Thermal Stability.

    PubMed

    Fu, Xiaopeng; Lü, Wei; Jiao, Mengmeng; You, Hongpeng

    2016-06-20

    A series of Ba4Gd3Na3(PO4)6F2:Eu(2+) phosphors with a broad emitting band have been synthesized by a traditional solid state reaction. The crystal structural and photoluminescence properties of Ba4Gd3Na3(PO4)6F2:Eu(2+) are investigated. The different crystallographic sites of Eu(2+) in Ba4Gd3Na3(PO4)6F2:Eu(2+) phosphors have been verified by means of their photoluminescence (PL) properties and decay times. Energy transfer between Eu(2+) ions, analyzed by excitation, emission, and PL decay behavior, has been indicated to be a dipole-dipole mechanism. Moreover, the luminescence quantum yield as well as the thermal stability of the Ba4Gd3Na3(PO4)6F2:Eu(2+) phosphor have been investigated systematically. The as-prepared Ba4Gd3Na3(PO4)6F2:Eu(2+) phosphor can act as a promising candidate for n-UV convertible white LEDs.

  13. Supercritical fluid extraction of 2,4,6-trinitrotoluene and 1,3,5-trinitrobenzene from soil

    SciTech Connect

    Wujcik, C.E.; Seiber, J.N.

    1996-07-01

    Optimization of a methanol-modified supercritical fluid extraction (SFE) technique using carbon dioxide has resulted in the effective recovery of 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitrobenzene (TNB) from spiked and native soils. Several parameters, including modifier concentration, temperature, density, and static and dynamic extraction time were varied independently to determine the effect of each on analyte recovery. The optimal SFE conditions are: 5% methanol, 150{degree}C, 7500 PSI, 5 minutes static extraction and 15 minutes dynamic extraction. Samples were analyzed by gas chromatography using electron-capture detection (ECD). SFE quantitatively recovered both TNT and TNB from the soil matrix in considerably less time than conventional Soxhlet extraction with ethyl acetate and sonication with acetonitrile. 12 refs., 4 figs., 5 tabs.

  14. 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.

  15. A Call to Action on New England's Innovation Economy: Will Business and Higher Education Answer This Time?

    ERIC Educational Resources Information Center

    Guenther, William

    2003-01-01

    Mass Insight Corp, a public policy and communications firm that organizes public-private initiatives to support economic growth in Massachusetts, recently issued a new report, titled "An Economy at Risk," making the case for a Massachusetts economic development strategy organized around higher education and science and technology. Massachusetts,…

  16. Universities' Autonomy in Times of Changing Higher Education Governance: A Study of the Swiss Academic Labour Market

    ERIC Educational Resources Information Center

    Baschung, Lukas; Goastellec, Gaele; Leresche, Jean-Philippe

    2011-01-01

    Although eternally debated, the issue of autonomy in higher education is rarely analysed in its complexity. To address this issue, this article uses an analytical matrix which combines the distinction between substantive and procedural autonomy and the distinction between HEI governing bodies, academic professions and individual academics. This…

  17. Breaking the Mold: New Approaches for Higher Education in Tough Economic Times. Complete to Compete Briefing Paper

    ERIC Educational Resources Information Center

    Carey, Kevin

    2011-01-01

    Human capital is the key to economic development. Without highly-skilled workers, states and territories cannot attract the productive businesses they need. That makes higher education a key element of any governor's growth strategy. But many public colleges and universities are struggling to produce more graduates. Overall graduation rates often…

  18. Quality after the Cuts? Higher Education Practitioners' Accounts of Systemic Challenges to Teaching Quality in Times of "Austerity"

    ERIC Educational Resources Information Center

    Feigenbaum, Anna; Iqani, Mehita

    2015-01-01

    What are the ramifications of current changes in the higher education landscape in the UK for the ways in which teaching staff perceive their teaching practices? What impact are funding cuts, increases in student fees and the concomitant increased workloads having on faculty morale? How might this influence "quality cultures" in teaching…

  19. Australian Higher Education Leaders in Times of Change: The Role of Pro Vice-Chancellor and Deputy Vice-Chancellor

    ERIC Educational Resources Information Center

    Scott, Geoff; Bell, Sharon; Coates, Hamish; Grebennikov, Leonid

    2010-01-01

    This paper discusses responses provided by 31 Pro Vice-Chancellors (PVCs) and Deputy Vice-Chancellors (DVCs) who were part of a larger study of more than 500 higher education leaders in roles ranging from DVC to head of programme in 20 Australian universities. Using both quantitative and qualitative data the paper gives an insider's perspective on…

  20. A Lesson of Lost Political Capital in Public Higher Education: Leadership Challenges in a Time of Needed Organizational Change

    ERIC Educational Resources Information Center

    Hilton, Mark; Jacobson, Rod

    2012-01-01

    All higher education institutions are struggling with a rapidly changing market and financial landscape. Here is a management-centered analysis of what happened when a college president, recognizing the need to make a radical adaptation to those changes, tried moving a campus community to a new organizational model, without collegial consensus,…

  1. Applying the Modality Principle to Real-Time Feedback and the Acquisition of Higher-Order Cognitive Skills

    ERIC Educational Resources Information Center

    Fiorella, Logan; Vogel-Walcutt, Jennifer J.; Schatz, Sae

    2012-01-01

    Effectively presenting complex material is a crucial component of instructional design within simulation-based training (SBT) environments. One approach to facilitate the acquisition of higher-order knowledge is to embed instructional strategies within the systems themselves. Currently, however, there are few established guidelines to inform…

  2. A Time of Quiet Activism: Research, Practice, and Policy in American Women's Higher Education, 1945-1965

    ERIC Educational Resources Information Center

    Eisenmann, Linda

    2005-01-01

    This article reflects on three narratives that affected American women's participation in higher education during the first twenty years after World War II. In hindsight, the educators of the 1950s and early 1960s may seem gratuitously meek and self-effacing. In comparison to later efforts, their activism can appear unnecessarily limited and too…

  3. Unprecedented Times in the Professionalisation and State Regulation of Counselling and Psychotherapy: The Role of the Higher Education Institute

    ERIC Educational Resources Information Center

    Murphy, David

    2011-01-01

    This article considers a number of issues facing those involved in counselling and psychotherapy training within United Kingdom Higher Education Institutes. It is proposed that the increasing professionalisation of counselling and psychotherapy has significant implications for lecturers and trainers. The article will explore the tension between…

  4. Just-in-Time Research: A Call to Arms for Research into Mobile Technologies in Higher Education

    ERIC Educational Resources Information Center

    Byrne-Davis, Lucie; Dexter, Hilary; Hart, Jo; Cappelli, Tim; Byrne, Ged; Sampson, Ian; Mooney, Jane; Lumsden, Colin

    2015-01-01

    Mobile technologies are becoming commonplace in society and in education. In higher education, it is crucial to understand the impact of constant access to information on the development of the knowledge and competence of the learner. This study reports on a series of four surveys completed by UK-based medical students (n = 443) who received…

  5. Funding System of Full-Time Higher Education and Technical Efficiency: Case of the University of Ljubljana

    ERIC Educational Resources Information Center

    Tajnikar, Maks; Debevec, Jasmina

    2008-01-01

    The present paper tackles the issue of the higher education funding system in Slovenia. Its main attribute is that institutions are classified into study groups according to their fields of education, and funds granted by the state are based on their weights or study group factors (SGF). Analysis conducted using data envelopment analysis tested…

  6. 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.…

  7. 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"…

  8. 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…

  9. CDK4/6 inhibition induces epithelial cell cycle arrest and ameliorates acute kidney injury

    PubMed Central

    DiRocco, Derek P.; Bisi, John; Roberts, Patrick; Strum, Jay; Wong, Kwok-Kin; Sharpless, Norman

    2013-01-01

    Acute kidney injury (AKI) is common and urgently requires new preventative therapies. Expression of a cyclin-dependent kinase (CDK) inhibitor transgene protects against AKI, suggesting that manipulating the tubular epithelial cell cycle may be a viable therapeutic strategy. Broad spectrum small molecule CDK inhibitors are protective in some kidney injury models, but these have toxicities and epithelial proliferation is eventually required for renal repair. Here, we tested a well-tolerated, novel and specific small molecule inhibitor of CDK4 and CDK6, PD 0332991, to investigate the effects of transient cell cycle inhibition on epithelial survival in vitro and kidney injury in vivo. We report that CDK4/6 inhibition induced G0/G1 cycle arrest in cultured human renal proximal tubule cells (hRPTC) at baseline and after injury. Induction of transient G0/G1 cycle arrest through CDK4/6 inhibition protected hRPTC from DNA damage and caspase 3/7 activation following exposure to the nephrotoxins cisplatin, etoposide, and antimycin A. In vivo, mice treated with PD 0332991 before ischemia-reperfusion injury (IRI) exhibited dramatically reduced epithelial progression through S phase 24 h after IRI. Despite reduced epithelial proliferation, PD 0332991 ameliorated kidney injury as reflected by improved serum creatinine and blood urea nitrogen levels 24 h after injury. Inflammatory markers and macrophage infiltration were significantly decreased in injured kidneys 3 days following IRI. These results indicate that induction of proximal tubule cell cycle arrest with specific CDK4/6 inhibitors, or “pharmacological quiescence,” represents a novel strategy to prevent AKI. PMID:24338822

  10. Reduction of the explosive 2,4,6-trinitrotoluene by enzymes from aquatic sediments

    SciTech Connect

    Beelen, P. van; Burris, D.R.

    1995-12-01

    Enzymes were extracted from aquatic sediments. Some of these enzymes reduced 2,4,6-trinitrotoluene (TNT) with nicotinamide adenosine dinucleotide phosphate (NADPH) as an electron donor under aerobic conditions. The origin of these enzymes was not clear as the enzymes were extracted from a sediment containing plant roots and microorganisms. Aquatic plants were determined to e a source of TNT-reducing enzymes. Chemical reduction was not a rate-limiting process in the assays as the enzymatic activity was inhibited by heating or the addition of proteases. Enzymatic activity in the extracts was further characterized. Partial purifications of enzymes from the sediment extracts shows that several proteins capable of reducing NT with NADPH were present. The enzymes did not require flavins and preferred NADPH over NADH as the electron donor. The pH optimum for the stability of the enzymes was near neutral, and the temperature optimum was in the 37 to 45 C range. Addition of dithiothreitol improved the stability of the enzymes. The enzymes reduced 2,4,6-trinitrotoluene to 2-amino-4,6-dinitrotoluene, 4-amino-2,6-dinitrotoluene, 2,4-diamino-6-nitrotoluene, and 2,6-diamino-4-nitrotoluene under aerobic conditions with NADPH. When used as a starting substrate, the aminodinitrotoluenes were not reduced by the enzymes. It might be possible that the hydroxylaminodinitrotoluenes are reduced to di[hydroxylamine]nitrotoluenes prior to the formation of the diaminonitrotoluenes. Sediments from 11 surface water bodies were examined for the presence of TNT-reducing enzymes, and 10 were found to have activity. These enzymes appear to be ubiquitous and are present in both freshwater and saltwater sediments. Reduction of TNT by sediment enzymes can be a significant environmental fate process for TNT in aquatic systems.

  11. CDK4/6 inhibition induces epithelial cell cycle arrest and ameliorates acute kidney injury.

    PubMed

    DiRocco, Derek P; Bisi, John; Roberts, Patrick; Strum, Jay; Wong, Kwok-Kin; Sharpless, Norman; Humphreys, Benjamin D

    2014-02-15

    Acute kidney injury (AKI) is common and urgently requires new preventative therapies. Expression of a cyclin-dependent kinase (CDK) inhibitor transgene protects against AKI, suggesting that manipulating the tubular epithelial cell cycle may be a viable therapeutic strategy. Broad spectrum small molecule CDK inhibitors are protective in some kidney injury models, but these have toxicities and epithelial proliferation is eventually required for renal repair. Here, we tested a well-tolerated, novel and specific small molecule inhibitor of CDK4 and CDK6, PD 0332991, to investigate the effects of transient cell cycle inhibition on epithelial survival in vitro and kidney injury in vivo. We report that CDK4/6 inhibition induced G0/G1 cycle arrest in cultured human renal proximal tubule cells (hRPTC) at baseline and after injury. Induction of transient G0/G1 cycle arrest through CDK4/6 inhibition protected hRPTC from DNA damage and caspase 3/7 activation following exposure to the nephrotoxins cisplatin, etoposide, and antimycin A. In vivo, mice treated with PD 0332991 before ischemia-reperfusion injury (IRI) exhibited dramatically reduced epithelial progression through S phase 24 h after IRI. Despite reduced epithelial proliferation, PD 0332991 ameliorated kidney injury as reflected by improved serum creatinine and blood urea nitrogen levels 24 h after injury. Inflammatory markers and macrophage infiltration were significantly decreased in injured kidneys 3 days following IRI. These results indicate that induction of proximal tubule cell cycle arrest with specific CDK4/6 inhibitors, or "pharmacological quiescence," represents a novel strategy to prevent AKI.

  12. Microbial Transformation of 2,4,6-Trinitrotoluene in Aerobic Soil Columns

    PubMed Central

    Bruns-Nagel, D.; Breitung, J.; von Low, E.; Steinbach, K.; Gorontzy, T.; Kahl, M.; Blotevogel, K.; Gemsa, D.

    1996-01-01

    2,4,6-Trinitrotoluene (TNT)-contaminated soil material of a former TNT production plant was percolated aerobically in soil columns. Nineteen days of percolation with a potassium phosphate buffer supplemented with glucose or glucose plus ammonium sulfate caused an over 90% decline in the amount of extractable nitroaromatics in soils containing 70 to 2,100 mg of TNT per kg (dry weight). In the percolation solution, a complete elimination of TNT was achieved. Mutagenicity and soil toxicity were significantly reduced by the percolation process. 4-N-Acetylamino-2-amino-6-nitrotoluene was generated in soil and percolation fluid as a labile TNT metabolite. PMID:16535369

  13. UV photolysis for enhanced phenol biodegradation in the presence of 2,4,6-trichlorophenol (TCP).

    PubMed

    Song, Jiaxiu; Wang, Wenbing; Li, Rongjie; Zhu, Jun; Zhang, Yongming; Liu, Rui; Rittmann, Bruce E

    2016-02-01

    A bacterial strain isolated from activated sludge and identified as Bacillus amyloliquefaciens could biodegrade phenol, but 2,4,6-trichlorophenol (TCP) inhibited phenol biodegradation and biomass growth. UV photolysis converted TCP into dichlorocatechol, monochlorophenol, and dichlorophenol, and this relieved inhibition by TCP. Phenol-removal and biomass-growth rates were significantly accelerated after UV photolysis: the monod maximum specific growth rate (μ(max)) increased by 9% after TCP photolysis, and the half-maximum-rate concentration (K(S)) decreased by 36%. Thus, the major benefit of UV photolysis in this case was to transform TCP into a set of much-less-inhibitory products.

  14. Chemical stability of molten 2,4,6-trinitrotoluene at high pressure

    NASA Astrophysics Data System (ADS)

    Dattelbaum, Dana M.; Chellappa, Raja S.; Bowden, Patrick R.; Coe, Joshua D.; Margevicius, Madeline A.

    2014-01-01

    2,4,6-trinitrotoluene (TNT) is a molecular explosive that exhibits chemical stability in the molten phase at ambient pressure. A combination of visual, spectroscopic, and structural (x-ray diffraction) methods coupled to high pressure, resistively heated diamond anvil cells was used to determine the melt and decomposition boundaries to >15 GPa. The chemical stability of molten TNT was found to be limited, existing in a small domain of pressure-temperature conditions below 2 GPa. Decomposition dominates the phase diagram at high temperatures beyond 6 GPa. From the calculated bulk temperature rise, we conclude that it is unlikely that TNT melts on its principal Hugoniot.

  15. Comparison of water quality criteria and health advisories for 2,4,6-trinitrotoluene

    SciTech Connect

    Ross, R.H.; Hartley, W.R. )

    1990-04-01

    The U.S. Environmental Protection Agency (USEPA) has recently recommended health advisories (HAs) for 2,4,6-trinitrotoluene (TNT). The purpose of this brief article is to present these values so that the reader can compare them with the water quality criteria that have been proposed in another article. In that article, a water quality criterion of 140 micrograms/liter for TNT in drinking water was proposed, and in the present article the methodology by which USEPA calculated a lifetime HA of 2 micrograms/liter is presented. The reasons why the water quality criterion and the HA differ are discussed.

  16. Factors affecting 2,4,6-trinitrotoluene degradation in contaminated soil

    SciTech Connect

    Bradley, P.M.; Chapelle, F.H.

    1995-12-31

    Recent microcosm studies at an inactive ordnance works at Weldon Spring, Missouri indicated that the indigenous microorganisms are capable of complete transformation oaf 2,4,6-trinitrotoluene (TNT) within approximately 22 days. However, the continuing presence of TNT at the Weldon Spring site suggests that some combination of environmental factors is inhibiting microbial degradation at the site. This paper briefly summarizes the results of investigations of the effects of carbon substrate availability, soil moisture content, TNT concentration, and oxygen condition on TNT degradation by the microorganisms indigenous to Weldon Spring.

  17. Crystal structure of 2,4,6-triisopropyl-2',5'-dimethoxybiphenyl

    NASA Astrophysics Data System (ADS)

    Sharma, N.; Prashanth, T.; Lakshmi Ranganatha, V.; Ara Khanum, S.; Kant, R.; Gupta, V. K.

    2015-12-01

    The title compound, 2,4,6-triisopropyl-2',5'-dimethoxybiphenyl was synthesized from 1-choloro-2.5-dimethoxy benzene, 1,3,5-triisopropylbenzene boronic acid and potassium phosphate in the presence of lead acetate as a catalyst and toluene as a solvent. Its crystal structure is determined by X-ray structure analysis. The crystals are the orthorhombic, a = 12.3281(4), b = 17.4235(5), c = 19.6550(6) Å, Z = 8, sp. gr. Pbca. R = 0.0603 for 2494 observed reflections.

  18. Toxicity and mutagenicity of 2,4,-6-trinitrotoluene and its microbial metabolites.

    PubMed Central

    Won, W D; DiSalvo, L H; Ng, J

    1976-01-01

    TNT (2,4,6-trinitrotoluene) of explosive grade is highly toxic to marine forms that included fresh water unicellular green algae (Selenastrum capricornutum), tidepool copepods (Tigriopus californicus), and oyster larvae (Crassostrea gigas), and mutagenic to Salmonella typhimurium. On the basis of mutagenic assays carried out with a set of histidine-requiring strains of the bacterium, TNT was detected as a frameshift mutagen that significantly accelerates the reversion rate of a frameshift tester, TA-98. In contrast, the major microbial metabolites of TNT appeared to be nontoxic and nonmutagenic. Images PMID:773306

  19. The use of amino compounds for binding 2,4,6-trinitrotoluene in water.

    PubMed

    Fant, F; De Sloovere, A; Matthijsen, K; Marlé, C; el Fantroussi, S; Verstraete, W

    2001-01-01

    Sites polluted with 2,4,6-trinitrotoluene (TNT) constitute a worldwide problem. In this work, chemical reactions for binding TNT to amino-compounds are proposed as an initial step for developing new remediation techniques to clean-up groundwater and soils contaminated with TNT. Indeed, addition of aniline and an amino acid-like cysteine caused a decrease in free TNT of 86% and 68-100%, respectively. Using 13C-NMR spectroscopy, it was shown that TNT chemically forms a Meisenheimer complex with cysteine and aniline in 1/1 (by vol.) H2O/d6-acetone.

  20. 2,4,6,8-Tetrachlorodibenzothiophene in the Newark Bay Estuary: the likely source and reaction pathways.

    PubMed

    Parette, Robert; Pearson, Wendy N

    2014-09-01

    Historic industrial activity along the Newark Bay Estuary has resulted in pollution from a number of contaminants; one of which is 2,4,6,8-tetrachlorodibenzothiophene (2,4,6,8-TCDT), a unique chemical contaminant whose origins have not been adequately explained. This research demonstrates that the probable source of 2,4,6,8-TCDT was the chlorination of phenol produced via the sulfonation method. Thiophenol, the major impurity in this type of phenol, was likely converted to 2,4,6,8-TCDT through one or more pathways during the production of 2,4-dichlorophenol, 2,4-dichlorophenoxyacetic acid (2,4-D), or 2,4,6-trichlorophenol. From a mass balance standpoint, production of these chemicals at an industrial plant along the Passaic River could account for the 2,4,6,8-TCDT in the Newark Bay Estuary. PMID:24997913

  1. 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

  2. Shock induced sub-detonation chemical reactions in 1,3,5-triamino-2,4,6-trinitrobenzene

    NASA Astrophysics Data System (ADS)

    Östmark, Henric

    1996-05-01

    The technique of combining slapper ignition with fast (12 μs/scan) time-of-flight mass spectroscopy has been used for studying the early shock-induced decomposition of TATB (1,3,5-triamino-2,4,6-trinitrobenzene). By varying the slapper energy, and hence the shock intensity, it was possible to vary the degree of reaction from a weak detonation to full detonation. As the slapper energy was lowered, several larger mass fragments were detected, e.g. m/z 242. This indicates that it is possible to detect early decomposition products using this technique. The same set of experiments was also conducted on isotopically labelled TATB (TATB-15N6) where the corresponding peak occurred at m/z 248. From this it was concluded that the peak resulted from a shock-induced elimination of oxygen, and hence that the early decomposition is a conversion of a nitro group to a nitroso group.

  3. Smartphone-based portable biosensing system using impedance measurement with printed electrodes for 2,4,6-trinitrotoluene (TNT) detection.

    PubMed

    Zhang, Diming; Jiang, Jing; Chen, Junye; Zhang, Qian; Lu, Yanli; Yao, Yao; Li, Shuang; Logan Liu, Gang; Liu, Qingjun

    2015-08-15

    Rapid, sensitive, selective and portable detection of 2,4,6-trinitrotoluene (TNT) is in high demand for public safety and environmental monitoring. In this study, we reported a smartphone-based system using impedance monitoring for TNT detection. The screen-printed electrodes modified with TNT-specific peptides were used as disposable a biosensor to produce impedance responses to TNT. The responses could be monitored by a hand-held device and send out to smartphone through Bluetooth. Then, the smartphone was used to display TNT responses in real time and report concentration finally. In the measurement, the system was demonstrated to detect TNT at concentration as low as 10(-6) M and distinguish TNT versus different chemicals in high specificity. Thus, the smartphone-based biosensing platform provided a convenient and efficient approach to design portable instruments for chemical detections such as TNT recognition.

  4. TOVS observation of a Stratospheric cooling during the CHEOPS 3 campaign: February 4-6, 1990, over Scandinavia

    SciTech Connect

    Claud, C.; Ovarlez, J.; Chedin, A.; Scott, N.A. )

    1993-04-20

    The authors report on further analysis of a stratospheric cooling event observed by CHEOPS 3 during February 4-6, 1990 over Scandinavia. The CHEOPS 3 observational program provided a large set of data regarding atmospheric conditions in the Arctic polar region which are of use in addressing the question of ozone depletion in the northern hemisphere. A large temperature excursion was observed in this period by the CHEOPS data, and the authors have applied a new inversion to TOVS observations of this same period to attempt to confirm this observation. Such a large excursion would allow the formation of polar stratospheric clouds. They were able to model the general cooling pattern seen by the CHEOPS 3 observations, but not the large temperature dip, and offer an alternative explanation of the accompanying dip in ozone column densities observed over Europe at this time.

  5. Proton radii of {sup 4,6,8}He isotopes from high-precision nucleon-nucleon interactions

    SciTech Connect

    Caurier, E.; Navratil, P.

    2006-02-15

    Recently, precision laser spectroscopy on {sup 6}He atoms determined accurately the isotope shift between {sup 4}He and {sup 6}He and, consequently, the charge radius of {sup 6}He. A similar experiment for {sup 8}He is under way. We have performed large-scale ab initio calculations for {sup 4,6,8}He isotopes using high-precision nucleon-nucleon (NN) interactions within the no-core shell model (NCSM) approach. With the CD-Bonn 2000 NN potential we found point-proton root-mean-square (rms) radii of {sup 4}He and {sup 6}He 1.45(1) fm and 1.89(4), respectively, in agreement with experiment and predict the {sup 8}He point-proton rms radius to be 1.88(6) fm. At the same time, our calculations show that the recently developed nonlocal INOY NN potential gives binding energies closer to experiment, but underestimates the charge radii.

  6. Some Fresh Indications of the Solar Origin of 4-6-YEAR Oscillation of the Earth's Rotation Parameters

    NASA Astrophysics Data System (ADS)

    Djurovic, D.; Paquet, P.

    The variations of universal times difference UT1-TAI and Earth's rotation instantaneous pole coordinates (X,Y) are studied in the frequency range of 3 - 8 yr-1 as a function of the solar activity. It is found that power spectrum concentrations C1 and C2 are common to solar activity indicators and Earth's rotation parameters (ERP). The linear correlation between them is also not a fortuitous one. Accordingly, by the results of this study the hypothesis of Djurovic and Paquet (1996; 1999) that the primary cause of 4-6 year oscillation lies in solar irradiance is confirmed. Between several mechanisms responsible for the ERP variations as the most probable are considered the variations of solar irradiance spectral structure (especially large in its UV range) and variations of intensity of cosmic X-rays reaching the Earth's surface.

  7. Proton Radii of 4,6,8He Isotopes from High-Precision Nucleon-Nucleon Interactions

    SciTech Connect

    Caurier, E; Navratil, P

    2005-11-16

    Recently, precision laser spectroscopy on {sup 6}He atoms determined accurately the isotope shift between {sup 4}He and {sup 6}He and, consequently, the charge radius of {sup 6}He. A similar experiment for {sup 8}He is under way. We have performed large-scale ab initio calculations for {sup 4,6,8}He isotopes using high-precision nucleon-nucleon (NN) interactions within the no-core shell model (NCSM) approach. With the CD-Bonn 2000 NN potential we found point-proton root-mean-square (rms) radii of {sup 4}He and {sup 6}He 1.45(1) fm and 1.89(4), respectively, in agreement with experiment and predict the {sup 8}He point proton rms radius to be 1.88(6) fm. At the same time, our calculations show that the recently developed nonlocal INOY NN potential gives binding energies closer to experiment, but underestimates the charge radii.

  8. Dosimetric shield evaluation with tungsten sheet in 4, 6, and 9MeV electron beams.

    PubMed

    Fujimoto, Takahiro; Monzen, Hajime; Nakata, Manabu; Okada, Takashi; Yano, Shinsuke; Takakura, Toru; Kuwahara, Junichi; Sasaki, Makoto; Higashimura, Kyoji; Hiraoka, Masahiro

    2014-11-01

    In electron radiotherapy, shielding material is required to attenuate beam and scatter. A newly introduced shielding material, tungsten functional paper (TFP), has been anticipated to become a very useful device that is lead-free, light, flexible, and easily processed, containing very fine tungsten powder at as much as 80% by weight. The purpose of this study was to investigate the dosimetric changes due to TFP shielding for electron beams. TFP (thickness 0-15mm) was placed on water or a water-equivalent phantom. Percentage depth ionization and transmission were measured for 4, 6, and 9MeV electron beams. Off-center ratio was also measured using film dosimetry at depth of dose maximum under similar conditions. Then, beam profiles and transmission with two shielding materials, TFP and lead, were evaluated. Reductions of 95% by using TFP at 0.5cm depth occurred at 4, 9, and 15mm with 4, 6, and 9MeV electron beams, respectively. It is found that the dose tend to increase at the field edge shaped with TFP, which might be influenced by the thickness. TFP has several unique features and is very promising as a useful tool for radiation protection for electron beams, among others.

  9. Concentrations of organochlorine pesticides and 2,4,6-trichloroanisole in cork bark.

    PubMed

    Olivella, M Àngels; Caixach, Josep; Planas, Carles; Oliveras, Anna; Jové, Patrícia

    2012-02-01

    Organochlorine pesticides are persistent lipophilic organic pollutants and tend to accumulate in growing plants. During growth, cork is in contact with the open air for long periods (9-12 years). Owing to the previous widespread use of organochlorine pesticides and their high persistence in the environment, there is a risk that residues of such pesticides may be present in cork. In this study, the concentrations of 14 organochlorine pesticides-all of which are indicators of environmental pollution-were analyzed in cork bark samples from three regions in Spain and one in Portugal. In addition, the concentrations of 2,4,6-trichlorophenol (TCP) and 2,4,6-trichloroanisole (TCA) were also analyzed. Our results show only very low concentrations of lindane, γ-HCH (<2.6 ng g(-1)) and its byproducts α-HCH (<3.5 ng g(-1)) and β-HCH (<0.6 ng g(-1)). Among the DDT and its metabolites, only two were found: p,p'-DDT was found in a cork sample from Extremadura (0.1 ng g(-1)) and p,p'-DDE was present at a maximum concentration of 2.9 ng g(-1) in a cork sample from Castile-La Mancha. However, all concentrations were well below the legal limit established by Regulation (EC) No. 396/2005 (10 ng g(-1) in foodstuffs). We can conclude, therefore, that the cork samples we studied complied with food safety standards.

  10. Growth and characterization of a new nonlinear optical organic crystal: 2,4,6-Trimethylacetanilide

    NASA Astrophysics Data System (ADS)

    Upadhyaya, V.; Prabhu, Sharada G.

    2015-09-01

    A new nonlinear optical organic material, 2,4,6-trimethylacetanilide (246TMAA), also known as N-[2,4,6- trimethylphenyl]acetamide, has been synthesized and grown as a single crystal by the slow evaporation technique by organic solvents. The grown crystals have been characterized by morphology study. The crystals are prismatic. Surface examination shows granular dendritic pattern in optical micrograph. The Scanning Electron Micrograph shows the layered growth of the crystal. The Differential Scanning Calorimeter plot shows no phase change until melting point (219°C). The density of the crystals is 1.1g/cc and the crystals are soft. The crystals are transparent in the visible region and in the ultra-violet region till 280 nm. 246TMAA crystallizes with 2 molecules in a monoclinic unit cell in the noncentrosymmetric point group m, space group Pn. Refractive indices of this optically biaxial crystal along the three crystallophysical axes have been measured at 633 nm. The optical second harmonic generation efficiency of the crystal at 1064 nm is about half that of the urea crystal, measured by powder method using Nd:YAG laser. The results show that the 246TMAA crystal can efficiently be used for up-conversion of infrared radiation into visible green light. The powder X-ray diffraction spectrum of the crystal has been obtained.

  11. Oxidative degradation of 2,4,6-trinitrotoluene by ozone in an electrohydraulic discharge reactor

    SciTech Connect

    Lang, P.S.; Ching, W.K.; Willberg, D.M.; Hoffmann, M.R.

    1998-10-15

    The electrohydraulic discharge process in the presence of ozone has been used to investigate the rapid degradation and mineralization of aqueous 2,4,6-trinitrotoluene (TNT) solutions that were directly exposed to high-energy electrical discharges between two submerged electrodes. The 165 {micro}M solutions of TNT were completely mineralized over the course of 300 electrical discharges of 7 kJ each. The kinetics of TNT degradation were investigated as a function of the aqueous-phase ozone concentration, pH, discharge energy, and electrode gas length. The rate of TNT degradation increases with an increase in aqueous-phase ozone concentration of up to 150 {micro}M, an increase in pH from 3.0 to 7.9, an increase in discharge energy from 5.5 to 9 kJ, and a decrease in the electrode gap length from 10 to 6 mm. The rapid rates of mineralization are attributed to the action of UV light in the reactor chamber on O{sub 3} to produce a high flux of hydroxyl radicals per discharge. The primary reaction intermediates were 2,4,6-trinitrobenzaldehyde and trinitrobenzene.

  12. 2,4,6-Trinitrotoluene reduction by carbon monoxide dehydrogenase from Clostridium thermoaceticum

    SciTech Connect

    Huang, S.; Lindahl, P.A.; Wang, C.; Bennett, G.N.; Rudolph, F.B.; Hughes, J.B.

    2000-03-01

    Purified CO dehydrogenase (CODH) from Clostridium thermoaceticum catalyzed the transformation of 2,4,6-trinitrotoluene (TNT). The intermediates and reduced products of TNT transformation were separated and appear to be identical to the compounds formed by C. acetobutylicum, namely, 2-hydroxylamino-4,6-dinitrotoluene (2 HA46DNT), 4-hydroxylamino-2,6-dinitrotoluene (4HA26DNT), 2,4-dihydroxylamino-6-nitrotoluene (24DHANT), and the Bamberger rearrangement product of 2,4-dihydroxylamino-6-nitrotoluene. In the presence of saturating CO, CODH catalyzed the conversion of TNT to two monohydroxylamino derivatives (2HA46DNT and 4HA26DNT), with 4HA26DNT as the dominant isomer. These derivatives were then converted to 24DHANT, which slowly converted to the Bamberger rearrangement product. Apparent K{sub m} and k{sub cat} values of TNT reduction were 165 {+-} 43 {micro}M for TNT and 400 {+-} 94 s{sup {minus}1}, respectively. Cyanide, an inhibitor for the CO/CO{sub 2} oxidation/reduction activity of CODH, inhibited the TNT degradation activity of CODH.

  13. Phytodetoxification of the environmental pollutant and explosive 2,4,6-trinitrotoluene.

    PubMed

    Rylott, Elizabeth L; Gunning, Vanda; Tzafestas, Kyriakos; Sparrow, Helen; Johnston, Emily J; Brentnall, Andrew S; Potts, Jennifer R; Bruce, Neil C

    2015-01-01

    Our recent study highlights the role of 2 glutathione transferases (GSTs) in the detoxification of the environmental pollutant, 2,4,6-trinitrotoluene (TNT) in Arabidopsis thaliana. TNT is toxic and highly resistant to biodegradation in the environment, raising both health and environmental concerns. Two GSTs, GST-U24 and GST-U25, are upregulated in response to TNT treatment, and expressed predominantly in the root tissues; the site of TNT location following uptake. Plants overexpressing GST-U24 and GST-U25 exhibited significantly enhanced ability to withstand and detoxify TNT, and remove TNT from contaminated soil. Analysis of the catalytic activities of these 2 enzymes revealed that they form 3 TNT-glutathionyl products. Of particular interest is 2-glutathionyl-4,6-dinitrotoluene as this represents a potentially favorable step toward subsequent degradation and mineralization of TNT. We demonstrate how GSTs fit into what is already known about pathways for TNT detoxification, and discuss the short and longer-term fate of TNT conjugates in planta.

  14. Determination of hemoglobin adducts in workers exposed to 2,4, 6-trinitrotoluene.

    PubMed

    Sabbioni, G; Wei, J; Liu, Y Y

    1996-07-12

    2,4,6-Trinitrotoluene (TNT) is an important occupational and environmental pollutant. TNT can be taken up through the skin and by inhalation. It is therefore essential to have fast and reliable methods to monitor human exposure. In rat experiments, it has been shown that TNT binds covalently to blood proteins and to tissue proteins. Hemoglobin (Hb) adducts of TNT are markers for the internal dose and possibly for the toxic effects of TNT, e.g. cataracts. In the present paper we introduce a new efficient method to quantify Hb adducts of TNT. Precipitated Hb was hydrolyzed with base in the presence of the surrogate internal standard 3,5-dinitroaniline (35DNA). The released 2-amino-4,6-dinitrotoluene (2ADNT) and 4-amino-2,6-dinitrotoluene (4ADNT) were quantified against 35DNA by gas chromatography-mass spectrometry with negative-ion chemical ionization. Hb of 50 workers and controls from a Chinese munition factory were investigated. The Hb adduct levels ranged from 3.7 to 522 ng for 4ADNT and from 0 to 14.7 ng for 2ADNT per gram of Hb. However, in control samples from Germany no Hb adducts of 4ADNT or 2ADNT could be found.

  15. Dosimetric shield evaluation with tungsten sheet in 4, 6, and 9MeV electron beams.

    PubMed

    Fujimoto, Takahiro; Monzen, Hajime; Nakata, Manabu; Okada, Takashi; Yano, Shinsuke; Takakura, Toru; Kuwahara, Junichi; Sasaki, Makoto; Higashimura, Kyoji; Hiraoka, Masahiro

    2014-11-01

    In electron radiotherapy, shielding material is required to attenuate beam and scatter. A newly introduced shielding material, tungsten functional paper (TFP), has been anticipated to become a very useful device that is lead-free, light, flexible, and easily processed, containing very fine tungsten powder at as much as 80% by weight. The purpose of this study was to investigate the dosimetric changes due to TFP shielding for electron beams. TFP (thickness 0-15mm) was placed on water or a water-equivalent phantom. Percentage depth ionization and transmission were measured for 4, 6, and 9MeV electron beams. Off-center ratio was also measured using film dosimetry at depth of dose maximum under similar conditions. Then, beam profiles and transmission with two shielding materials, TFP and lead, were evaluated. Reductions of 95% by using TFP at 0.5cm depth occurred at 4, 9, and 15mm with 4, 6, and 9MeV electron beams, respectively. It is found that the dose tend to increase at the field edge shaped with TFP, which might be influenced by the thickness. TFP has several unique features and is very promising as a useful tool for radiation protection for electron beams, among others. PMID:24953537

  16. CDK4/6 inhibitor suppresses gastric cancer with CDKN2A mutation

    PubMed Central

    Huang, Shiliang; Ye, Hua; Guo, Wenying; Dong, Xianwen; Wu, Nali; Zhang, Xie; Huang, Zhigang

    2015-01-01

    Aim: Gastric cancer is a major health problem and current treatment lacks lasting effect. Targeted therapy for gastric cancer with specific genetic background is in urgent need. Methods: We have studied The Cancer Genomic Atlas (TCGA) and The Genomics of Drug Sensitivity in Cancer (GDSC) databases to reveal genes with high frequency of mutation and possible sensitive compound against such gene mutation. In vitro studies were conducted to validate the in silico findings. Results: CDKN2A is frequently mutated in gastric cancer, revealed in TCGA database. CDK4/6 inhibitor PD-0332991 was sensitive in cancer cells with CDKN2A mutation, revealed in GDSC database. In vitro studies showed that PD-0332991 could selectively inhibit proliferation of gastric cancer cell with CDKN2A mutation. PD-0332991 could also inhibit cell invasion, migration, and colony formation of gastric cancer cell with CDKN2A mutation. PD-0332991 induced cell cycle arrest but not apoptosis. PD-0332991 inhibited xenograft gastric cancer mouse model. Conclusion: Gastric cancer with CDKN2A mutation is sensitive to CDK4/6 inhibitor. PD-0332991 is a potential therapeutic agent for gastric cancer. PMID:26380006

  17. Synthesis and crystal structure of Na4Ni7(AsO4)6

    PubMed Central

    David, Rénald

    2016-01-01

    The title compound, tetra­sodium hepta­nickel hexa­arsenate, was obtained by ceramic synthesis and crystallizes in the monoclinic space group C2/m. The asymmetric unit contains seven Ni atoms of which two have site symmetry 2/m and three site symmetry 2, four As atoms of which two have site symmetry m and two site symmetry 2, three Na atoms of which two have site symmetry 2, and fifteen O atoms of which four have site symmetry m. The structure of Na4Ni7(AsO4)6 is made of layers of Ni octa­hedra and As tetra­hedra assembled in sheets parallel to the bc plane. These layers are inter­connected by corner-sharing between NiO6 octa­hedra and AsO4 tetra­hedra. This linkage creates tunnels running along the c axis in which the Na atoms are located. This arrangement is similar to the one observed in Na4Ni7(PO4)6, but the layers of the two compounds are slightly different because of the disorder of one of the Ni sites in the structure of the title compound. PMID:27308006

  18. Spectral properties of new N, N'-bis-alkyl-1,4,6,8-naphthalenediimide complexes

    NASA Astrophysics Data System (ADS)

    Refat, M. S.; Grabchev, I.; Chovelon, J.-M.; Ivanova, G.

    2006-05-01

    The photophysical properties of two N, N'-bis-alkyl-1,4,6,8-naphthalenediimide (DCN1 and DCN2) have been studied in chloroform and N, N-dimethylformamide solvents. The ability of DCN2 in N, N-dimethylformamide to detect metal cations have been monitored by the fluorescence emission spectroscopy. It has been shown that the fluorescent intensity is very sensitive to the concentration of Fe 3+ cations. The reaction of iodine with N, N'-bis-alkyl-1,4,6,8-naphthalenediimide in chloroform solution have been investigated by spectrophotometric method. The results indicate the formation of two CT-complexes [(DCN1)I] +·I 3- and [(DCN2)I] +·I 3- at donor:acceptor molar ratio of 1:2. The [(DCN1)I] +·I 3- shows the characteristic absorptions of I 3- ion at 290 and 360 nm while the charge-transfer transition of [(DCN2)I] +·I 3- occurs at 310 nm. Three characteristic bands at the far infrared region in each iodine complex are observed around 135, 105 and 85 cm -1 due to νas (I-I), νs (I-I) and δ (I 3-), respectively with C2v symmetry. The values of the complex formation constant, K, and the absorptivity, ɛ have been calculated.

  19. Emission switching of 4,6-diphenylpyrimidones: solvent and solid state effects.

    PubMed

    Adjaye-Mensah, Edward; Gonzalez, Walter G; Bussé, David R; Captain, Burjor; Miksovska, Jaroslava; Wilson, James N

    2012-08-30

    The photophysics of 1-ethyl-4,6-bis(4-methoxyphenyl)-2(1H)-pyrimidone (1) and 1-ethyl-4,6-bis(4-(dimethylamino)phenyl)-2(1H)-pyrimidone (2) were investigated to determine the mechanisms of emission switching in response to protonation. UV-vis and steady state emission spectroscopy of the protonated and unprotonated forms across a range of solvents reveal the polarity dependence of the vertical excitation energies. Emission lifetimes and quantum yields show the solvent dependency of the excited states. Emission enhancements were observed in polyethylene glycol solutions and in the solid state (both thin film and single crystal), demonstrating the role of intramolecular rotation in thermal relaxation of the excited states. TD-DFT calculations provide insights into the excited state geometries and the role of intramolecular charge transfer. The collected data show that emission of diphenylpyrimidones can be modulated by four factors, including the identity of the electron-donating auxochrome, protonation state, solvent polarity, and viscosity. PMID:22856457

  20. 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…

  1. 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…

  2. 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:…

  3. 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…

  4. Preparation of 1,3,5-triamino-2,4,6-trinitrobenzene from 3,5-dichloroanisole

    SciTech Connect

    Ott, Donald G.; Benziger, Theodore M.

    1991-01-01

    Preparation of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) from 3,5-dichloroanisole. Nitration of 3,5-dichloroanisole under relatively mild conditions gave 3,5-dichloro-2,4,6-trinitroanisole in high yield and purity. Ammonolysis of this latter compound gave the desired TATB. Another route to TATB was through the treatment of the 3,5-dichloro-2,4,6-trinitroanisole with thionyl chloride and dimethylformamide to yield 1,3,5-trichloro-2,4,6-trinitrobenzene. Ammonolysis of this product produced TATB.

  5. Preparation of 1,3,5-triamino-2,4,6-trinitrobenzene from 3,5-dichloranisole

    SciTech Connect

    Oh, D.G.; Benziger, T.M.

    1990-08-28

    This patent describes the preparation of 1,3,5-triamino-2,4,6- trinitrobenzene (TATB) from 2,5-dichloroanisole. Nitration of 3,5- dichloroanisole under relatively mild conditions gave 3,5-dichloro-2,4,6- trinitroanisole in high yield and purity. Ammonolysis of this latter compound gave the desired TATB. Another route to TATB was through the treatment of the 3,5-dichloro-2,4,6-trinitroanisole with thionyl chloride and dimethylformamide to yield 1,3,5-trichloro-2,4,6- trinitrobenzene. Ammonolysis of this product produced TATB.

  6. Preparation of 1,3,5-triamino-2,4,6-trinitrobenzene from 3,5-dichloroanisole

    SciTech Connect

    Ott, D.G.; Benziger, T.M.

    1991-03-05

    Preparation of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) from 3,5-dichloroanisole is described. Nitration of 3,5-dichloroanisole under relatively mild conditions gave 3,5-dichloro-2,4,6-trinitroanisole in high yield and purity. Ammonolysis of this latter compound gave the desired TATB. Another route to TATB was through the treatment of the 3,5-dichloro-2,4,6-trinitroanisole with thionyl chloride and dimethylformamide to yield 1,3,5-trichloro-2,4,6-trinitrobenzene. Ammonolysis of this product produced TATB. 8 figures.

  7. Preparation of 1,3,5-triamino-2,4,6-trinitrobenzene from 3,5-dichloranisole

    SciTech Connect

    Ott, Donald G.; Benziger, Theodore M.

    1990-01-01

    Preparation of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) from 3,5-dichloroanisole. Nitration of 3,5-dichloroanisole under relatively mild conditions gave 3,5-dichloro-2,4,6-trinitroanisole in high yield and purity. Ammonolysis of this latter compound gave the desired TATB. Another route to TATB was through the treatment of the 3,5-dichloro-2,4,6-trinitroanisole with thionyl chloride and dimethylformamide to yield 1,3,5-trichloro-2,4,6-trinitrobenzene. Ammonolysis of this product produced TATB.

  8. Acyclic Nucleoside Bisphosphonates: Synthesis and Properties of Chiral 2-Amino-4,6-bis[(phosphonomethoxy)alkoxy]pyrimidines

    PubMed Central

    Doláková, Petra; Dračínský, Martin; Masojídková, Milena; Šolínová, Veronika; Kašička, Václav; Holý, Antonín

    2009-01-01

    2-Amino-4,6-bis[(phosphonomethoxy)alkoxy]pyrimidines bearing two equal or different achiral or chiral phosphonoalkoxy chains have been prepared either by aromatic nucleophilic substitution of 2-amino-4,6-dichloropyrimidine or by alkylation of 4,6-dihydroxy-2-(methylsulfanyl)pyrimidine with appropriate phosphonate–bearing building block. Alkylation of 4,6-dihydroxy-2-(methylsulfanyl)pyrimidine proved to be the method of choice for efficient preparation of variety of bisphosphonates. The enantiomerical purity of selected compounds was determined by capillary electrophoresis. Antiviral activity of bisphosphonates is discussed. PMID:18992968

  9. Deformation-induced ω phase in modified Ti-29Nb-13Ta-4.6Zr alloy by Cr addition.

    PubMed

    Li, Qiang; Niinomi, Mitsuo; Hieda, Junko; Nakai, Masaaki; Cho, Ken

    2013-08-01

    For spinal-fixation applications, implants should have a high Young's modulus to reduce springback during operations, though a low Young's modulus is required to prevent stress shielding for patients after surgeries. In the present study, Ti-29Nb-13Ta-4.6Zr alloy (TNTZ) with a low Young's modulus was modified by adding Cr to obtain a higher deformation-induced Young's modulus in order to satisfy these contradictory requirements. Two newly designed alloys, TNTZ-8Ti-2Cr and TNTZ-16Ti-4Cr, possess more stable β phases than TNTZ. These alloys consist of single β phases and exhibit relatively low Young's moduli of <65GPa after solution treatment. However, after cold rolling, they exhibit higher Young's moduli owing to a deformation-induced ω-phase transformation. These modified TNTZ alloys show significantly less springback than the original TNTZ alloy based on tensile and bending loading-unloading tests. Thus, the Cr-added TNTZ alloys are beneficial for spinal-fixation applications. PMID:23624220

  10. Development of a microwave assisted extraction method for the analysis of 2,4,6-trichloroanisole in cork stoppers by SIDA-SBSE-GC-MS.

    PubMed

    Vestner, Jochen; Fritsch, Stefanie; Rauhut, Doris

    2010-02-15

    The aim of this research work was focused on the replacement of the time-consuming soaking of cork stoppers which is mainly used as screening method for cork lots in connection with sensory analysis and/or analytical methods to detect releasable 2,4,6-trichloroanisole (TCA) of natural cork stoppers. Releasable TCA from whole cork stoppers was analysed with the application of a microwave assisted extraction method (MAE) in combination with stir bar sorptive extraction (SBSE). The soaking of corks (SOAK) was used as a reference method to optimise MAE parameters. Cork lots of different quality and TCA contamination levels were used to adapt MAE. Pre-tests indicated that an MAE at 40 degrees C for 120 min with 90 min of cooling time are suitable conditions to avoid an over-extraction of TCA of low and medium tainted cork stoppers in comparison to SOAK. These MAE parameters allow the measuring of almost the same amounts of releasable TCA as with the application of the soaking procedure in the relevant range (<25 ng L(-1) releasable TCA from one cork) to evaluate the TCA level of cork stoppers. Stable isotope dilution assay (SIDA) was applied to optimise quantification of the released TCA with deuterium-labelled TCA (TCA-d(5)) using a time-saving GC-MS technique in single ion monitoring (SIM) mode. The developed MAE method allows the measuring of releasable TCA from the whole cork stopper under improved conditions and in connection with a low use of solvent and a higher sample throughput.

  11. Elastic Properties of 4-6 nm-thick Glassy Carbon Thin Films

    NASA Astrophysics Data System (ADS)

    Manoharan, M. P.; Lee, H.; Rajagopalan, R.; Foley, H. C.; Haque, M. A.

    2010-01-01

    Glassy carbon is a disordered, nanoporous form of carbon with superior thermal and chemical stability in extreme environments. Freestanding glassy carbon specimens with 4-6 nm thickness and 0.5 nm average pore size were synthesized and fabricated from polyfurfuryl alcohol precursors. Elastic properties of the specimens were measured in situ inside a scanning electron microscope using a custom-built micro-electro-mechanical system. The Young’s modulus, fracture stress and strain values were measured to be about 62 GPa, 870 MPa and 1.3%, respectively; showing strong size effects compared to a modulus value of 30 GPa at the bulk scale. This size effect is explained on the basis of the increased significance of surface elastic properties at the nanometer length-scale.

  12. The 21st LH Gray Conference (June 4-6, 2008)

    SciTech Connect

    C. M. L. West; Martin, C. J.; Sutton, D. G.; Wright, E. G.

    2009-01-12

    The 21st LH Gray Conference, organised by the LH Gray Trust with the Society for Radiological Protection, brought together international experts in radiobiology, epidemiology and risk assessment, and scientists involved in diagnostic and therapeutic radiation exposure. The meeting - held in Edinburgh, Scotland 4-6 June 2008 - aimed to raise awareness, educate and share knowledge of important issues in radiation protection. A distinguished group of speakers discussed topics which included: non-targeted effects of radiation, exposure to high natural background radiation, non-cancer effects in Japanese bomb survivors, lessons learnt from Chernobyl, radiation in the workplace, biokinetic modelling, uncertainties in risk estimation, issues in diagnostic medical exposures, lessons leant from the polonium-210 incidence and how the radiobiology-radiation oncology community is needed to help society prepare for potential future acts of radiation terrorism. The conference highlighted the importance, relevance and topicality of radiobiology today.

  13. Phonological development in 4-6-year-old moderately hearing impaired children.

    PubMed

    Huttunen, K H

    2001-01-01

    The acquisition of clear phonological rules is of utmost importance for a child when he/she is learning to decode and convey meanings using spoken language. Fifteen Finnish-speaking children, five normally hearing (NH) 3-year-olds and 10 moderately hearing impaired (HId) 4-6-year-olds were studied here. Speech samples consisting of 62 words were collected from each child during a picture naming task. Frequent phonetic (articulation) errors together with normal (but delayed) and deviant phonological processes of HId children were found in this study. The frequency and quality of the processes seemed to be related more to the grade of HI than, for example, the age of the child. Implications for speech therapy are briefly discussed.

  14. A Versatile Synthesis of 1,3,5-Triamino-2,4,6-Trinitrobenzene (TATB)

    SciTech Connect

    Mitchell, A R; Pagoria, P F; Schmidt, R D; Coburn, M D; Lee, G S; Hsu, P C

    2006-04-06

    A safe and versatile synthesis of high-purity 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) based on vicarious nucleophilic substitution (VNS) chemistry has now been achieved. The starting material can be selected from a variety of inexpensive nitroarenes obtained from commercial suppliers (4-nitroaniline, picric acid) or U.S. stockpiles (ammonium picrate, TNT). The use of picric acid and ammonium picrate (Explosive D) is preferred as both compounds are directly converted to picramide in the presence of ammonium salts (diammonium hydrogen phosphate, ammonium carbamate) in sulfolane at elevated temperature. The picramide resulting from this process is directly converted to TATB using an optimized VNS reaction employing inexpensive hydroxylamine as the nucleophilic aminating reagent. A crucial element in our synthesis is a novel and efficient purification of TATB.

  15. Clinical Development of the CDK4/6 Inhibitors Ribociclib and Abemaciclib in Breast Cancer.

    PubMed

    Barroso-Sousa, Romualdo; Shapiro, Geoffrey I; Tolaney, Sara M

    2016-06-01

    Clinical and preclinical data support a significant role for inhibitors of the cyclin-dependent kinases (CDKs) 4 and 6 in the treatment of patients with breast cancer. Recently, based on data showing improvement in progression-free survival, the use of palbociclib (Ibrance; Pfizer, Inc.) in combination with endocrine agents was approved to treat patients with hormone receptor-positive advanced disease. Importantly, 2 other CDK4/6 inhibitors, abemaciclib (LY2835219; Lilly) and ribociclib (LEE011; Novartis), are in the late stage of clinical development. In this review, we will focus on clinical data on these 2 new drugs, highlighting their differences compared to palbociclib in terms of single-agent activity, central nervous system penetration, and common adverse events. In addition, we will present the ongoing clinical trials and discuss future directions in the field. PMID:27493615

  16. The high-pressure phase behavior and compressibility of 2,4,6-trinitrotoluene

    SciTech Connect

    Stevens, Lewis L.; Velisavljevic, Nenad; Hooks, Daniel E.; Dattelbaum, Dana M.

    2008-10-24

    The phase stability and isothermal compression behavior of 2,4,6-trinitrotoluene (TNT) have been established to 26.5 GPa using angle-dispersive x-ray diffraction. P-V isotherms derived from the high-pressure x-ray spectra displayed a slight density hysteresis around 4.0 GPa and a sharp discontinuity at - 20.0 GPa. The latter transition is ascribed to a monoclinic-to-orthorhombic first-order phase transition in TNT. The conversion of the isothermal P-V data to the shock velocity-particle velocity plane revealed a deviation from linearity at low u{sub p}, a cusp associated with the phase transition at high u{sub p}, and general agreement with the wealth of unreacted Hugoniot data on TNT.

  17. Reduction of 2,4,6-trinitrotoluene by Clostridium acetobutylicum through hydroxylamino-nitrotoluene intermediates

    SciTech Connect

    Hughes, J.B.; Wang, C.Y.; Bhadra, R.; Richardson, A.; Bennett, G.N.; Rudolph, F.B.

    1998-03-01

    Studies were conducted to isolate and identify intermediates of 2,4,6-trinitrotoluene (TNT) transformation by Clostridium acetobutylicum and to quantify their concentrations in active whole cell cultures. Only two intermediates of TNT reduction were detected in cell cultures and were identified as 4-hydroxylamino-2,6-dinitrotoluene and 2,4-dihydroxylamino-6-nitrotoluene. Structures were confirmed with {sup 1}H-NMR, {sup 13}C-NMR, and desorption chemical ionization mass spectroscopy. When cells were suspended in a non-growth saline medium, both hydroxylamine forms accumulated. In media capable of supporting cell growth, the 2,4-dihydroxylamino-6-nitrotoluene accumulated with concentrations of 4-hydroxylamino-2,6-dinitrotoluene remaining near detection limits. Studies using purified 2,4-dihydroxylamino-6-nitrotoluene confirmed that its biotransformation rate in active cultures greatly exceeded abiotic decomposition in aqueous medium.

  18. Toxicity assessment and biodegradation potential of water-soluble sludge containing 2,4,6-trinitrotoluene.

    PubMed

    Nehrenheim, E; Muter, O; Odlare, M; Rodriguez, A; Cepurnieks, G; Bartkevics, V

    2013-01-01

    The water-soluble phase of trinitrotoluene-containing sludge (SLP) was characterized with regard to trinitrotoluene (TNT) concentration, ecotoxicity, and a model biodegradation experiment as evaluation criteria for further development of appropriate treatment technologies. SLP contained 67.8 mg TNT/l. The results of germination and root-elongation tests indicated that SLP had a species-specific phytotoxic effect. The results of a 21 day degradation experiment demonstrated TNT conversion to 4-amino-2,6-DNT and 2-amino-4,6-DNT, with a simultaneous reduction in the total concentration of nitroaromatics. Addition of inoculum stimulated the TNT degradation process. The presence of the sludge solid phase inhibited microbial activity. Measurement of microbial enzyme activity was used to assess changes in the microbial community during the biodegradation process.

  19. The high-pressure phase stability of 2,4,6-trinitrotoluene (TNT)

    NASA Astrophysics Data System (ADS)

    Bowden, P. R.; Chellappa, R. S.; Dattelbaum, D. M.; Manner, V. W.; Mack, N. H.; Liu, Z.

    2014-05-01

    2,4,6-trinitrotoluene (TNT) is a widely used explosive that is relatively insensitive to initiation by shock loading. While the detonation properties of TNT have been extensively reported, the high pressure-temperature (P-T) stability of TNT has not been investigated in detail. At ambient conditions, TNT crystallizes in a monoclinic lattice (space group P21/a), and our previous X-ray diffraction (XRD) measurements at room temperature suggested a phase transition to orthorhombic (space group Pca21) at ~20 GPa. In this work, we have performed in-situ synchrotron XRD and vibrational spectroscopy measurements along the room temperature isotherm to investigate phase stabilities up to 18 GPa. While our Raman spectroscopy measurements indicate spectral changes at ~2 GPa, careful XRD measurements reveal that the monoclinic phase persists up to 10 GPa.

  20. Chemical stability of molten 2,4,6-trinitrotoluene at high pressure

    SciTech Connect

    Dattelbaum, Dana M. Chellappa, Raja S.; Bowden, Patrick R.; Coe, Joshua D.; Margevicius, Madeline A.

    2014-01-13

    2,4,6-trinitrotoluene (TNT) is a molecular explosive that exhibits chemical stability in the molten phase at ambient pressure. A combination of visual, spectroscopic, and structural (x-ray diffraction) methods coupled to high pressure, resistively heated diamond anvil cells was used to determine the melt and decomposition boundaries to >15 GPa. The chemical stability of molten TNT was found to be limited, existing in a small domain of pressure-temperature conditions below 2 GPa. Decomposition dominates the phase diagram at high temperatures beyond 6 GPa. From the calculated bulk temperature rise, we conclude that it is unlikely that TNT melts on its principal Hugoniot.

  1. Sediment mediated reduction and sorption of 2,4,6-trinitrotoluene and resulting reaction products

    SciTech Connect

    Elovitz, M.S.; Weber, E.J.

    1995-12-01

    The reductive transformation of 2,4,6-trinitrotoluene (TNT) to aromatic amines and the consequent fate of these products in sediment-water systems were studied. Pathway elucidation and mass balance analyses of the reduction of TNT in oxic and anoxic sediment-water systems indicated that the fate of TNT was highly dependent on the redox status of the system. Reduction of TNT to aminodinitrotoluene and subsequently to diaminonitrotoluene products appeared to have both biotic and abiotic components. Reduction was rapid under anoxic, methanogenic conditions, but was significantly slower under oxic conditions. Subsequent sorption of the diaminonitrotoluene products was rapid under oxic conditions and resulted in nearly complete, irreversible retention by the sediment phase. In contrast, under anoxic conditions, the rapidly formed diaminonitrotoluene compounds displayed little affinity for the sediment phase. Instead, the diaminonitrotoluenes were further transformed to products that also showed little capacity for sorption.

  2. Bioremediation of 2,4,6-trinitrotoluene-contaminated soils by two different aerated compost systems.

    PubMed

    Breitung, J; Bruns-Nagel, D; Steinbach, K; Kaminski, L; Gemsa, D; von Löw, E

    1996-02-01

    Two composting systems were compared on a laboratory scale as a bioremediation technology for degradation or immobilization of 2,4,6-trinitrotoluene (TNT) in contaminated soils. The first compost was aerated from the beginning whereas the second compost was only aerated after an anaerobic prephase of 65 days. In the first compost system the TNT concentration declined rapidly by 92% but, at the end, TNT could be partially recovered. During the anaerobic prephase of the second compost system, TNT was almost completely converted to aminodinitrotoluenes, which during the subsequent aeration almost entirely disappeared. In addition, the second compost generated less toxic material than the first one as confirmed by inhibition of bioluminescence of Vibrio fischeri. These data show that microbiological TNT-degradation systems can be successfully designed which are prerequisite for an efficient bioremediation of contaminated soils.

  3. Bioslurry treatment for soils contaminated with very high concentrations of 2,4,6-trinitrophenylmethylnitramine (tetryl).

    PubMed

    Fuller, Mark E; Kruczek, Jessica; Schuster, Rachel L; Sheehan, Pamela L; Arienti, Per M

    2003-06-27

    Past and current DoD activities have resulted in the contamination of soil, sediment and groundwater with various explosive compounds. This research was undertaken to determine the effectiveness of a soil bioslurry process for remediation of soil with very high concentrations of 2,4,6-trinitrophenylmethylnitramine (tetryl). A 99.9% reduction in tetryl concentrations (from 100,000 to below 100 mg/kg) was achieved in 180 to 200 days. A variety of process modifications (i.e. addition of fertilizer, microbial biomass, purging with nitrogen, etc.) that were performed during the course of the experiment did not increase the tetryl biodegradation rate beyond the rates of degradation without modifications. Subsequent batches of soil added as a 25% (v/v) replacement of the slurry were also degraded. These results indicate the potential for this process to remediate highly contaminated soils at many former and current ammunition manufacturing sites.

  4. Selective CDK4/6 inhibition with tumor responses by PD0332991 in patients with mantle cell lymphoma.

    PubMed

    Leonard, John P; LaCasce, Ann S; Smith, Mitchell R; Noy, Ariela; Chirieac, Lucian R; Rodig, Scott J; Yu, Jian Q; Vallabhajosula, Shankar; Schoder, Heiko; English, Patricia; Neuberg, Donna S; Martin, Peter; Millenson, Michael M; Ely, Scott A; Courtney, Rachel; Shaik, Naveed; Wilner, Keith D; Randolph, Sophia; Van den Abbeele, Annick D; Chen-Kiang, Selina Y; Yap, Jeffrey T; Shapiro, Geoffrey I

    2012-05-17

    Mantle cell lymphoma (MCL) carries an unfavorable prognosis and requires new treatment strategies. The associated t(11:14) translocation results in enhanced cyclin D1 expression and cyclin D1-dependent kinase activity to promote cell-cycle progression. A pharmacodynamic study of the selective CDK4/6 inhibitor PD0332991 was conducted in 17 patients with relapsed disease, using 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) and 3-deoxy-3[(18)F]fluorothymidine (FLT) positron emission tomography (PET) to study tumor metabolism and proliferation, respectively, in concert with pre- and on-treatment lymph node biopsies to assess retinoblastoma protein (Rb) phosphorylation and markers of proliferation and apoptosis. Substantial reductions in the summed FLT-PET maximal standard uptake value (SUV(max)), as well as in Rb phosphorylation and Ki-67 expression, occurred after 3 weeks in most patients, with significant correlations among these end points. Five patients achieved progression-free survival time of > 1 year (range, 14.9-30.1+ months), with 1 complete and 2 partial responses (18% objective response rate; 90% confidence interval, 5%-40%). These patients demonstrated > 70%, > 90%, and ≥ 87.5% reductions in summed FLT SUV(max) and expression of phospho-Rb and Ki67, respectively, parameters necessary but not sufficient for long-term disease control. The results of the present study confirm CDK4/6 inhibition by PD0332991 at a well-tolerated dose and schedule and suggest clinical benefit in a subset of MCL patients. This study is registered at www.clinicaltrials.gov under identifier NCT00420056.

  5. Rhodococcus percolatus sp. nov., a bacterium degrading 2,4,6-trichlorophenol.

    PubMed

    Briglia, M; Rainey, F A; Stackebrandt, E; Schraa, G; Salkinoja-Salonen, M S

    1996-01-01

    A bacterial strain that was able to mineralize 2,4,6-trichlorophenol was isolated from a chlorophenol-fed percolator and was identified as a member of the genus Rhodococcus on the basis of chemotaxonomic characteristics and 16S RNA phylogenetic inference data. This organism (strain MBS1T [T = type strain]) exhibited a typical irregular rod-coccus cycle, and the cells had fimbria-like structures on their surfaces. The diagnostic cell wall amino acid was meso-diaminopimelic acid, and the sugars were arabinose and galactose; the mycolic acids contained 46 to 54 carbon atoms. The main menaquinone was MK-8(H2), and MK-9(H2) was a minor component. The cellular phospholipids were phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositolmannoside, phosphatidylglycerol, and diphosphatidylglycerol. Tuberculostearic acid was present. The whole-cell fatty acids were straight-chain acids with 14 to 18 C atoms. The G+C content of the DNA was 67.4 mol%. This organism grew on sucrose, pyruvate, and 2,4,6-trichlorophenol, and it oxidized a large number of carbon compounds, including catechol, 3-hydroxyphenylacetic acid, and phenol. It also exhibited beta-galactosidase, urease, and 2-acetyl-lactate decarboxylase activities. On a phylogenetic tree that was based on 16S ribosomal DNA gene sequences strain MBS1T was found among the rhodococci on an independent branch. On the basis of the chemotaxonomic and phenotypic characteristics of strain MBS1T and its phylogenetic position we suggest that this bacterium should be placed in a new species, Rhodococcus percolatus; the specific epithet was chosen because the organism was isolated by using an enriched percolator. The type strain is strain MBS1. PMID:8573500

  6. Genotoxicity and potential carcinogenicity of 2,4,6-TNT trinitrotoluene: structural and toxicological considerations.

    PubMed

    Bolt, Hermann M; Degen, Gisela H; Dorn, Susanne B; Plöttner, Sabine; Harth, Volker

    2006-01-01

    Environmental contamination with 2,4,6-TNT (trinitrotoluene) represents a worldwide problem. Concern for carcinogenicity can be derived from chemically related compounds, especially the dinitrotoluenes. In the metabolism of TNT, the reductive routes are preponderant. The main urinary metabolites of TNT are 4-amino-2,6-dinitrotoluene and 2-amino-4,6-dinitrotoluene. In humans exposed to TNT, the formation of hemoglobin adducts of the amino-dinitrotoluenes is in general concordance with the ratio of urinary excretion. The variations in quantities of excreted metabolites among the different occupational cohorts studied are likely explained by the different routes of exposure to TNT, including dermal uptake. Most studies show that urinary excretion of the amino-dinitrotoluenes (4-amino-dinitrotoluene plus 2-amino-dinitrotoluene) in a range of 1 to 10 mg L(-1) (5-50 microM) are not uncommon--for instance in persons employed with the disposal of military waste. Trinitotoluene is mutagenic in Salmonella typhimurium strains TA98 and TA100, with and without exogenous metabolic activation. Mutagenic activity has been found in urine from workers who were occupationally exposed to TNT. An unpublished 2-year study was reported in 1984 by the IIT Research Institute, Chicago, IL. Fischer 344 rats were fed diets containing 0.4, 2.0, 10, or 50 mg/kg TNT per day. In the urinary bladder, hyperplasia (12 of 47 animals p < .01) and carcinoma (11 of 47 animals, p < .05) were observed at significant levels in high-dose (50 mg kg(-1)) females and in one or two females, respectively, at 10 mg kg(-1). Taking all the available evidence together, the appropriate precautions should be taken.

  7. 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

  8. 44 CFR 4.6 - What procedures apply to the selection of programs and activities under these regulations?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 44 Emergency Management and Assistance 1 2013-10-01 2013-10-01 false What procedures apply to the selection of programs and activities under these regulations? 4.6 Section 4.6 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY GENERAL...

  9. 44 CFR 4.6 - What procedures apply to the selection of programs and activities under these regulations?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 44 Emergency Management and Assistance 1 2014-10-01 2014-10-01 false What procedures apply to the selection of programs and activities under these regulations? 4.6 Section 4.6 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY GENERAL...

  10. 44 CFR 4.6 - What procedures apply to the selection of programs and activities under these regulations?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true What procedures apply to the selection of programs and activities under these regulations? 4.6 Section 4.6 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY GENERAL...

  11. 44 CFR 4.6 - What procedures apply to the selection of programs and activities under these regulations?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 44 Emergency Management and Assistance 1 2011-10-01 2011-10-01 false What procedures apply to the selection of programs and activities under these regulations? 4.6 Section 4.6 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY GENERAL...

  12. SEDIMENT-MEDIATED REDUCTION OF 2,4,6-TRINITROTOLUENE AND FATE OF THE RESULTING AROMATIC (POLY)AMINES

    EPA Science Inventory

    2,4,6-Trinitrotoluene is a major surface and subsurface contaminant found at numerous munitions production and storage facilities. The reductive transformation of 2,4,6-trinitrotoluene (TNT) to aromatic (poly)amines and the consequent fate of these products were studied in anaer...

  13. Thermal processing of acidified foods with pH 4.1 to pH 4.6

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shelf-stable acidified foods with a pH at or below 4.6 must be processed to achieve a 5-log reduction for vegetative bacterial pathogens. Published research does not exist to adequately support the Food and Drug Administration process filings for products with pH 4.1–4.6 or to define critical limits...

  14. Design of a novel Cu₂O/TiO₂/carbon aerogel electrode and its efficient electrosorption-assisted visible light photocatalytic degradation of 2,4,6-trichlorophenol.

    PubMed

    Wang, Yabo; Zhang, Ya-Nan; Zhao, Guohua; Tian, Hongyi; Shi, Huijie; Zhou, Tianchen

    2012-08-01

    Cu(2)O/TiO(2) heterojunction photocatalyst is built on carbon aerogel (CA) substrate with good adsorption properties by sol impregnation and seed-mediated synthesis approach. The Cu(2)O/TiO(2)/CA electrode has excellent electrosorptive and high efficient photocatalytic properties. Its morphology and surface chemical composition are characterized with SEM, TEM, X-ray diffraction (XRD) and Raman spectra. The UV-vis diffuse reflectance spectra show that the optical absorption edge for Cu(2)O/TiO(2)/CA appears at 636 nm. Under visible-light (λ > 420 nm) irradiation, the photocurrent density increment on Cu(2)O/TiO(2)/CA is 60 times of that on Cu(2)O/TiO(2)/FTO. The electrochemical characteristic is investigated with electrochemical impedance spectrum (EIS). The Cu(2)O/TiO(2)/CA electrode is further applied in the electrosorptive photodegradation of the 2,4,6-trichlorophenol (2,4,6-TCP) wastewater. The result shows that the removal ratio of 2,4,6-TCP in 5.5 h on Cu(2)O/TiO(2)/CA is 96.3% and the TOC removal is 91.3%. The intermediates generated in the degradation process are analyzed by GC-MS and HPLC. The possible mechanism of visible light photocatalytic degradation of 2,4,6-TCP on Cu(2)O/TiO(2)/CA is also studied. PMID:22780307

  15. Degradation of 2,4,6-Trichlorophenol Using Hydrogen Peroxide Catalyzed by Nanoscale Zero-Valent Iron Supported on Ion Exchange Resin.

    PubMed

    Tai, Chao; She, Jiaping; Yin, Yongguang; Zhao, Tongqian; Wu, Li

    2016-06-01

    Nanoscale zero-valent iron (NZVI) supported on ion exchange resin was prepared and characterized by scanning electron microscope and energy dispersive spectroscopy, with a simple model developed for describing the catalyst. The degradation of 2,4,6-trichlorophenol (2,4,6-TCP) by hydrogen peroxide using NZVI supported on ion exchange resin as the catalyst, was studied. The results showed that 2,4,6-TCP with a concentration of 1 mmol L(-1) could be well degraded into low molecule weight organic acids in two hours. The optimized condition was as follows: pH, 3.0; temperature, 35 degrees C; catalyst dosage, 1.5 g; and hydrogen peroxide, 0.16 mmol L(-1). The catalyst has good reusability, with no catalytic efficiency decreasing even after ten times recycles. A possible mechanism of 2,4,6-TCP degradation was proposed, based on the products indentified by GC-MS after derived using trimethylsulfonium hydroxide. PMID:27427643

  16. 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…

  17. 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…

  18. 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.

  19. 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.

  20. Tolerance to, and uptake and degradation of 2,4,6-trinitrotoluene (TNT) are enhanced by the expression of a bacterial nitroreductase gene in Arabidopsis thaliana.

    PubMed

    Kurumata, Mami; Takahashi, Misa; Sakamotoa, Atsushi; Ramos, Juan L; Nepovim, Ales; Vanek, Tomas; Hirata, Toshifumi; Morikawa, Hiromichi

    2005-01-01

    Arabidopsis thaliana was transformed with a gene encoding a nitroreductase (NTR, E.C.1.6.99.7) with activity against a wide range of nitroaromatic compounds. The gene was transferred from Escherichia coli by an Agrobacterium-mediated in planta method. The obtained seeds were sowed to produce T1 plants, and they were assayed for the integration of the transgene in the plant genome. Transgenic plants that were positive with the PCR analysis were self-pollinated to produce T2 generation plants. Seven lines obtained were assayed for the NTR activity. While the non-transformed wild-type plants showed no detectable NTR activity, the enzyme activity of the transgenic plant lines was approx. 20 times higher. Using the line with the highest NTR activity, the phytoremediation characteristics of plants against 2,4,6-trinitrotoluene (TNT) was investigated. While the wild-type plants did not grow in the presence of 0.1 mM TNT, the transgenic plants grew almost normally in this condition. The uptake of TNT by seedlings of transgenic plants increased by 7 to 8 times when theywere floated on TNT solution. HPLC analysis showed that the peak due to TNT taken upinto plant body was much smaller in the transgenic plants as compared with that of the wild type, and that a number of peaks attributable to the degradation products of TNT, including 4-amino-2,6-dinitrotoluene, were detected in the extract from the transgenic plants. This indicates that the expression of bacterial NTR improved the capability of plants to degrade TNT. PMID:15948595

  1. 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

  2. The role of nutrients in the biodegradation of 2,4,6-trinitrotoluene in liquid and soil.

    PubMed

    Muter, Olga; Potapova, Katrina; Limane, Baiba; Sproge, Kristine; Jakobsone, Ida; Cepurnieks, Guntis; Bartkevics, Vadims

    2012-05-15

    The widely used explosive 2,4,6-trinitrotoluene (TNT) has residues that are potentially explosive, toxic, and mutagenic. TNT and other explosives can be degraded by microorganisms; however, biostimulation is needed for process efficiency. To investigate the effectiveness of using biostimulation to degrade TNT, we added varying concentrations of a nutrient amendment consisting of inorganic salts, plant extracts, and molasses to soil and liquid media. For the inoculum we used a consortium of bacteria AM 06 that had exhibited the ability to degrade TNT and which had been previously isolated from explosives-contaminated soils. Phylogenetically, the clones clustered into seven different genera: Klebsiella, Raoultella, Serratia, Stenotrophomonas, Pseudoxanthomonas, Achromobacter and Pseudomonas. The addition of AM 06 consortium to a liquid environment along with 100% nutrient amendment decreased the amount of TNT (and its degradation products) by up to 90% after 14 days incubation. At the total amount of TNT was less than 100 mg/l, the concentration of TNT did not influence the amount of sugar consumed by the bacteria consortium. In soil media, the TNT degradation process was dependent on the concentration of nutrient amendment added. At higher initial concentrations of TNT (500 mg/kg), bioaugmentation (i.e., addition of bacteria inoculum) had a demonstrated effect, especially when nutrient concentrations of 50% and 100% were added to the soil. Findings of this study could further the understanding of the TNT biodegradation processes in water and soil and provide for optimization of the technological conditions for bioremediation.

  3. The Effects of SPARK Physical Education Program on Fundamental Motor Skills in 4-6 Year-Old Children

    PubMed Central

    Mostafavi, Reza; Ziaee, Vahid; Akbari, Hakimeh; Haji-Hosseini, Samaneh

    2013-01-01

    Objective The purpose of this study was to investigate the effect of SPARK Physical Education (PE) program on fundamental motor skills in 4-6 year children. SPARK (Sports, Play, and Active Recreation for Kids) is an evidence based PE program designed in order to promote the lifelong wellbeing. Methods In total, 90 children aged 4 to 6 years were selected randomly. The children were allocated into 3 groups with separate PE programs: 1-SPARK, 2-Gymnastics and 3-Routine activity. Using the Test of Gross Motor Development (TGMD-2), a pretest was done in all groups. Afterwards, SPARK and Gym PE programs were performed for 8 weeks and 3 sessions each week. The third group used to do the routine physical education program in their daycare. After 8 weeks (24 sessions), the post tests were done for all groups with the same scoring system as the pretest. Findings The results showed that the SPARK program had a higher efficacy on the promotion of the fundamental motor skills comparing to the routine physical education programs or gymnastics PE group. Conclusion SPARK can be used as an appropriate alternative in order to promote the children's motor skills. PMID:23724186

  4. Discovery and preliminary SAR of 5-arylidene-2,2-dimethyl-1,3-dioxane- 4,6-diones as platelet aggregation inhibitors.

    PubMed

    El Maatougui, Abdelaziz; Azuaje, Jhonny; Coelho, Alberto; Cano, Ernesto; Yañez, Matilde; López, Carmen; Yaziji, Vicente; Carbajales, Carlos; Sotelo, Eddy

    2012-08-01

    We herein document the discovery of 5-arylidene-2,2-dimethyl-1,3-dioxane-4,6-diones as a novel family of platelet aggregation inhibitors. The preliminary optimization study enabled us to establish the most salient features of the structure-activity relationships in this series as well as to identify novel derivatives that are upto 60 times more potent than the hit structure 1 and slightly superior to the reference drug Milrinone. PMID:22272691

  5. Discovery and preliminary SAR of 5-arylidene-2,2-dimethyl-1,3-dioxane- 4,6-diones as platelet aggregation inhibitors.

    PubMed

    El Maatougui, Abdelaziz; Azuaje, Jhonny; Coelho, Alberto; Cano, Ernesto; Yañez, Matilde; López, Carmen; Yaziji, Vicente; Carbajales, Carlos; Sotelo, Eddy

    2012-08-01

    We herein document the discovery of 5-arylidene-2,2-dimethyl-1,3-dioxane-4,6-diones as a novel family of platelet aggregation inhibitors. The preliminary optimization study enabled us to establish the most salient features of the structure-activity relationships in this series as well as to identify novel derivatives that are upto 60 times more potent than the hit structure 1 and slightly superior to the reference drug Milrinone.

  6. CDK4/6 inhibition provides a potent adjunct to Her2-targeted therapies in preclinical breast cancer models

    PubMed Central

    Witkiewicz, Agnieszka K.; Cox, Derek; Knudsen, Erik S.

    2014-01-01

    In spite of the efficacy of Her2-targeted therapies, recurrence and progression remain a challenge for treatment of Her2 positive breast cancer. CDK4/6 controls pathway downstream of Her2, Inhibition of these kinases could represent an important therapeutic approach to augment the effectiveness of standard therapies. In models of acquired resistance to Her2-targeted therapies, Cyclin D1 was inappropriately activated and CDK4/6 inhibition was effective at blocking proliferation by targeting this common pathway associated with resistance. These data were recapitulated in Her2 positive xenografts. Furthermore, in a series of 35 primary breast tumor explants, treatment with PD-0332991 resulted in a greater than 4-fold suppression of the Ki67. The effects of CDK4/6 inhibition were dependent on an intact RB-pathway, and consonantly, loss of RB and high-levels of p16 were associated with resistance to CDK4/6 inhibition. Combination studies illustrated that CDK4/6 inhibition is cooperative with multiple Her2-targeted agents and provides a complementary mechanism of action to T-DM1 to efficiently suppresses the proliferation of residual Her2-positive tumor cell populations that survive T-DM1. Together, these data indicate CDK4/6 is a viable therapeutic target that functions downstream of Her2, and tissue based markers are available to direct rational utilization of CDK4/6 inhibitors in combination with Her2-targeted agents. PMID:25221644

  7. Metabolic re-programming of pancreatic cancer mediated by CDK4/6 inhibition elicits unique vulnerabilities

    PubMed Central

    Franco, Jorge; Balaji, Uthra; Freinkman, Elizaveta; Witkiewicz, Agnieszka K.; Knudsen, Erik S.

    2016-01-01

    Due to loss of p16ink4a in pancreatic ductal adenocarcinoma (PDA), pharmacological suppression of CDK4/6 could represent a potent target for treatment. In PDA models CDK4/6 inhibition had variable effect on cell cycle, but yielded accumulation of ATP and mitochondria. Pharmacological CDK4/6 inhibitors induce cyclin D1 protein levels; however, RB activation was required and sufficient for mitochondrial accumulation. CDK4/6 inhibition stimulated glycolytic and oxidative metabolism and was associated with an increase in mTORC1 activity. MTOR and MEK inhibitors potently cooperate with CDK4/6 inhibition in eliciting cell cycle exit. However, MTOR inhibition fully suppressed metabolism and yielded apoptosis and suppression of tumor growth. The metabolic state mediated by CDK4/6 inhibition increases mitochondrial number and ROS. Concordantly, the suppression of ROS scavenging or BCL2-antagonists cooperated with CDK4/6 inhibition. Together, these data define the impact of therapeutics on PDA metabolism and provide strategies for converting cytostatic response to tumor cell killing. PMID:26804906

  8. The possible reduction pathways of 2,4,6-trinitrotoluene (TNT) by sulfide under simulated anaerobic conditions.

    PubMed

    Qiao, Hua; Feng, Hua-jun; Liu, Shao-ying; Wang, Chao-jun; Zhang, Yuan; Gao, Yan-ni; Li, Wen-bing; Yao, Jun; Wang, Mei-zhen; Shen, Dong-sheng

    2011-01-01

    To predict the final fate of 2,4,6-trinitrotoluene (TNT) and its intermediates in an anaerobic fermentative solution containing reduced sulfur species and to provide a basis for the adoption of remediation methods, we investigated the pathways of TNT (TNT(0) = 50 mg/L) reduction by Na(2)S at 30 ± 1 °C in an acetic acid-sodium bicarbonate buffer. Liquid chromatography/mass spectrometry (LC/MS) was used to identify TNT metabolites at different reaction times. The law of growth and decline of TNT and its metabolites was determined with time. The LC/MS result, combined with the physicochemical characteristics of related products and information from the literature, indicated possible TNT conversion pathways. Sulfide can initiate both nitroreduction and denitration of TNT simultaneously. Nitroreduction led to the accumulation of primary intermediates 4-hydroxylaminodinitrotoluene and 4-aminodinitrotoluene, whereas denitration resulted in the production of unidentified substances with molecular weight less than that of TNT. Also, polyreaction between the above intermediates formed many unidentified substances. Humification was concluded to be the best choice for remediation of TNT-contaminated soil and water due to the formation of intermediates with stable, intact aromatic systems. However, the denitration pathway of TNT offered the possibility of mineralization. PMID:22170844

  9. Enhanced Raman spectroscopy of 2,4,6-TNT in anatase and rutile titania nanocrystals

    NASA Astrophysics Data System (ADS)

    De La Cruz-Montoya, Edwin; Jeréz, Jaqueline I.; Balaguera-Gelves, Marcia; Luna-Pineda, Tatiana; Castro, Miguel E.; Hernández-Rivera, Samuel P.

    2006-05-01

    The majority of explosives found in antipersonnel and antitank landmines contain 2,4,6-trinitrotoluene (TNT). Chemical sensing of landmines and Improvised Explosive Devices (IED) requires detecting the chemical signatures of the explosive components in these devices. Nanotechnology is ideally suited to needs in microsensors development by providing new materials and methods that can be employed for trace explosive detection. This work is focused on modification of nano-scaled colloids of titanium dioxide (Titania: anatase, rutile and brookite) and thin layer of the oxides as substrates for use in Enhanced Raman Scattering (ERS) spectroscopy. Ultrafine particles have been generated by hydrothermally treating the sol-gel derived hydrous oxides. ERS spectra of nanocrystalline anatase Titania samples prepared with different average sizes: 38 nm (without acid), 24 nm (without acid) and 7 nm (with HCl). Bulk phase (commercial) and KBr were also used to prepare mixtures with TNT to look for Enhanced Raman Effect of the nitroaromatic explosive on the test surfaces. The studies clearly indicated that the anatase crystal size affects the enhancement of the TNT Raman signal. This enhancement was highest for the samples with Titania average crystal size of 7 nm.

  10. Prevalence of Sleep Disorders Among Children 4 - 6 Years Old in Tehran Province, Iran

    PubMed Central

    Ozgoli, Giti; Sheikhan, Zohre; Soleimani, Farin; Nasiri, Malihe; Amiri, Saba

    2016-01-01

    Background Sleep patterns may change over a person’s lifetime; however, the quantity and quality of sleep always depend on individual factors such as age, sex, and psychological and environmental factors. In children, sleep is as important as development. Quantitative sleep problems related to sleep onset and qualitative sleep disorders such as frequent awakenings may lead to insufficient sleep. Objectives This study aimed to assess the prevalence of sleep disorders among children 4 - 6 years old attending the health centers of Shahid Beheshti University of Medical Sciences, Tehran, Iran, in 2013. Patients and Methods This was a cross-sectional study on 400 children selected using a multistage sampling method. Data were collected by interviews. The questionnaire included two sections: a demographic section with questions about the demographic characteristics of the children and parents and a children’s sleep habit questionnaire (CSHQ). Data were analyzed by SPSS 16 and different statistical tests were used (P < 0.05). Results The mean age of the children was 64.27 ± 9.3 months. The prevalence of sleep disorders was 36.25%. Sleep disorders were significantly associated with age, height, body mass index, residence of children, father’s occupation, mother’s diseases, father’s drug abuse, and parents’ marital status (P < 0.05). Conclusions Sleep disorders in children threaten growth and development, and are dangerous for their health. Sleep disorders should be considered in the differential diagnosis of children’s learning and behavioral problems. PMID:27651942

  11. A CDK4/6-Dependent Epigenetic Mechanism Protects Cancer Cells from PML-induced Senescence.

    PubMed

    Acevedo, Mariana; Vernier, Mathieu; Mignacca, Lian; Lessard, Frédéric; Huot, Geneviève; Moiseeva, Olga; Bourdeau, Véronique; Ferbeyre, Gerardo

    2016-06-01

    Promyelocytic leukemia (PML) plays a tumor suppressive role by inducing cellular senescence in response to oncogenic stress. However, tumor cell lines fail to engage in complete senescence upon PML activation. In this study, we investigated the mechanisms underlying resistance to PML-induced senescence. Here, we report that activation of the cyclin-dependent kinases CDK4 and CDK6 are essential and sufficient to impair senescence induced by PML expression. Disrupting CDK function by RNA interference or pharmacological inhibition restored senescence in tumor cells and diminished their tumorigenic potential in mouse xenograft models. Complete senescence correlated with an increase in autophagy, repression of E2F target genes, and an gene expression signature of blocked DNA methylation. Accordingly, treatment of tumor cells with inhibitors of DNA methylation reversed resistance to PML-induced senescence. Further, CDK inhibition with palbociclib promoted autophagy-dependent degradation of the DNA methyltransferase DNMT1. Lastly, we found that CDK4 interacted with and phosphorylated DNMT1 in vitro, suggesting that CDK activity is required for its stabilization. Taken together, our findings highlight a potentially valuable feature of CDK4/6 inhibitors as epigenetic modulators to facilitate activation of senescence programs in tumor cells. Cancer Res; 76(11); 3252-64. ©2016 AACR.

  12. Treatment of 2,4,6-trinitrotoluene (TNT) red water by vacuum distillation.

    PubMed

    Zhao, Quanlin; Ye, Zhengfang; Zhang, Mohe

    2010-08-01

    2,4,6-Trinitrotoluene (TNT) red water from Chinese explosive industry was treated by vacuum distillation. The water quality before and after distillation was evaluated using high performance liquid chromatograph, UV-vis spectroscopy, Gas Chromatography/Mass Spectroscopy (GC/MS) and other physical and chemical analyses. The acute toxicity of TNT red water and its distillate was evaluated by determining the luminescence inhibition of Vibrio qinghaiensis sp. Nov. The results showed that the parameters except pH of the distillate met the criterion specified by the Chinese discharge standard for water pollutants from ordnance industry. Distillation removed chemical oxygen demand almost completely and the chrominance was reduced from 100,000 degrees to 17 degrees . The concentrations of 2,4-dinitrotoluene-3-sulfonate and 2,4-dinitrotoluene-5-sulfonate decreased from 20 x 10(3) and 31 x 10(3)mg L(-1) to 1.3 and 1.8 mg L(-1), respectively. GC/MS results showed that most of the organic components of TNT red water can be removed by distillation. The acute toxicity of water sample after distillation reduced 96%, compared with that of unprocessed TNT red water.

  13. Dual-goal facilitation in Wason's 2-4-6 task: what mediates successful rule discovery?

    PubMed

    Gale, Maggie; Ball, Linden J

    2006-05-01

    The standard 2-4-6 task requires discovery of a single rule and produces success rates of about 20%, whereas the dual-goal (DG) version requests discovery of two complementary rules and elevates success to over 60%. The experiment examined two explanations of DG superiority: Evans' (1989) positivity-bias account, and Wharton, Cheng, and Wickens' (1993) goal-complementarity theory. Two DG conditions were employed that varied the linguistic labelling of rules (either positively labelled Dax vs. Med, or mixed-valence "fits" vs. "does not fit"). Solution-success results supported the goal-complementarity theory since facilitation arose in both DG conditions relative to single-goal tasks, irrespective of the linguistic labelling of hypotheses. DG instructions also altered quantitative and qualitative aspects of hypothesis-testing behaviour, and analyses revealed the novel result that the production of at least a single descending triple mediates between DG instructions and task success. We propose that the identification of an appropriate contrast class that delimits the scope of complementary rules may be facilitated through the generation of a descending instance. Overall, our findings can best be accommodated by Oaksford and Chater's (1994) iterative counterfactual model of hypotheses testing, which can readily subsume key elements of the goal-complementarity theory. PMID:16608752

  14. Transformation of 2,4,6-trinitrotoluene by the aquatic plant Myriophyllum spicatum

    SciTech Connect

    Pavlostathis, S.G.; Comstock, K.K.; Jacobson, M.E.; Saunders, F.M.

    1998-11-01

    The ability of the aquatic plant Eurasian Watermilfoil (Myriophyllum spicatum) to transform 2,4,6-trinitrotoluene (TNT) was investigated in a series of batch assays. The TNT was added to plant cultures in single and multiple consecutive additions, at various initial concentrations, to determine its transformation kinetics, identify products formed, evaluate phytotoxic effects, and to determine the effect of light deprivation on the TNT transformation process. Rapid disappearance of TNT from the plant culture media was observed. The TNT disappearance rate was a function of both plant and TNT concentration (i.e., followed mixed, second-order kinetics). The TNT transformation occurred only in the presence of plants and was inhibited by the addition of sodium azide. Phytotoxicity leading to plant chlorosis was observed in batch plant cultures with an initial TNT concentration above 5.9 {micro}M. Reductive transformation of TNT to aminodinitrotoluenes and lower levels of hydroxylaminodinitrotoluene and diaminonitrotoluenes detected in the plant culture media accounted for less than 10 to 20% of the total TNT mass added. Extraction of plant material at the end of batch incubations when all TNT was depleted from the media yielded low levels of TNT and aminodinitrotoluenes and accounted for only 3.4% of the initially added TNT mass. Light deprivation decreased both the rate and extent of the reductive transformation of TNT.

  15. Two new polytypes of 2,4,6-tri­bromo­benzo­nitrile

    PubMed Central

    Britton, Doyle; Noland, Wayland E.; Tritch, Kenneth J.

    2016-01-01

    Three polymorphs of 2,4,6-tri­bromo­benzo­nitrile (RCN), C7H2Br3N, two of which are novel and one of which is a redetermination of the original structure first determined by Carter & Britton [(1972). Acta Cryst. B28, 945–950] are found to be polytypic. Each has a layer structure which differs only in the stacking of the layers. Each layer is composed of mol­ecules associated through C N⋯Br contacts which form R 2 2(10) rings. Two such rings are associated with each N atom; one with each ortho-Br atom. No new polytypes of 1,3,5-tri­bromo-2-iso­cyano­benzene (RNC) were found but a re-determination of the original structure by Carter et al. [(1977). Cryst. Struct. Commun. 6, 543–548] is presented. RNC was found to be isostructural with one of the novel polytypes of RCN. Unit cells were determined for 23 RCN samples and 11 RNC samples. Polytypes could not be distinguished based on crystal habits. In all four structures, each mol­ecule of the asymmetric unit lies across a mirror plane. PMID:26958382

  16. Aerobic biodegradation of 2,4,6-trinitrotoluene (TNT) by Bacillus cereus isolated from contaminated soil.

    PubMed

    Mercimek, H Aysun; Dincer, Sadık; Guzeldag, Gulcihan; Ozsavli, Aysenur; Matyar, Fatih

    2013-10-01

    In this study, biological degradation of 2,4,6-trinitrotoluene (TNT) which is very highly toxic environmentally and an explosive in nitroaromatic character was researched in minimal medium by Bacillus cereus isolated from North Atlantic Treaty Organization (NATO) TNT-contaminated soils. In contrast to most previous studies, the capability of this bacteria to transform in liquid medium containing TNT was investigated. During degradation, treatment of TNT was followed by high-performance liquid chromatography (HPLC) and achievement of degradation was calculated as percentage. At an initial concentration of 50 and 75 mg L(-1), TNT was degraded respectively 68 % and 77 % in 96 h. It transformed into 2,4-dinitrotoluene and 4-aminodinitrotoluene derivates, which could be detected as intermediate metabolites by using thin-layer chromatography and gas chromatography-mass spectrometry analyses. Release of nitrite and nitrate ions were searched by spectrophotometric analyses. Depending upon Meisenheimer complex, while nitrite production was observed, nitrate was detected in none of the cultures. Results of our study propose which environmental pollutant can be removed by using microorganisms that are indigenous to the contaminated site. PMID:23715804

  17. Integrated photocatalytic-biological reactor for accelerated 2,4,6-trichlorophenol degradation and mineralization.

    PubMed

    Zhang, Yongming; Sun, Xia; Chen, Lujun; Rittmann, Bruce E

    2012-02-01

    An integrated photocatalytic-biological reactor (IPBR) was used for accelerated degradation and mineralization of 2,4,6-trichlorophenol (TCP) through simultaneous, intimate coupling of photocatalysis and biodegradation in one reactor. Intimate coupling was realized by circulating the IPBR's liquid contents between a TiO(2) film on mat glass illuminated by UV light and honeycomb ceramics as biofilm carriers. Three protocols-photocatalysis alone (P), biodegradation alone (B), and integrated photocatalysis and biodegradation (photobiodegradation, P&B)-were used for degradation of different initial TCP concentrations. Intimately coupled P&B also was compared with sequential P and B. TCP removal by intimately coupled P&B was faster than that by P and B alone or sequentially coupled P and B. Because photocatalysis relieved TCP inhibition to biodegradation by decreasing its concentration, TCP biodegradation could become more important over the full batch P&B experiments. When phenol, an easy biodegradable compounds, was added to TCP in order to promote TCP mineralization by means of secondary utilization, P&B was superior to P and B in terms of mineralization of TCP, giving 95% removal of chemical oxygen demand. Cl(-) was only partially released during P experiments (24%), and this corresponded to its poor mineralization in P experiments (32%). Thus, intimately coupled P&B in the IPBR made it possible obtain the best features of each: rapid photocatalytic transformation in parallel with mineralization of photocatalytic products.

  18. Influence of dietary 2,4,6-trinitrotoluene exposure in the northern bobwhite (Colinus virginianus).

    PubMed

    Gogal, Robert M; Johnson, Mark S; Larsen, Calvert T; Prater, Mary R; Duncan, Robert B; Ward, Daniel L; Holladay, Steven D

    2002-01-01

    The risk to wildlife from exposure to the explosive, 2,4,6-trinitrotoluene (TNT) has been a concern at numerous military installations where it has been found in the soil. To date, no published data are available describing effects of TNT exposure in an avian species. Subchronic dietary exposure to TNT was therefore evaluated in a species of management concern at military installations, the northern bobwhite (Colinus virginianus). Adult male and female quail (n = 5/sex/dose) were given commercial feed containing 3,000, 1,500, 750, and 100 mg/kg TNT for 90 d following the determination of an acute lethal dose and a 14-d range finding study. Dietary TNT intake caused a dose-dependent decrease in total red blood cell counts, packed cell volume, total plasma protein, blood prolymphocytes, and blood lymphocytes. An increased trend in late apoptotic/necrotic blood leukocytic cells was also observed in TNT-exposed birds, as was hemosiderosis in the liver. With the exception of hemosiderosis, these trends were statistically significant yet of questionable biological significance. Since treatment-related responses in this preliminary study were variable, a conservative interpretation is suggested. However, since these treatments had concentrations that were a log-fold or more than doses in similar studies using mammals, these data suggest that northern bobwhite are less sensitive to oral exposures of TNT than mammals.

  19. The high pressure-temperature phase behavior of 2,4,6-trinitrotoluene (TNT)

    NASA Astrophysics Data System (ADS)

    Bowden, Patrick; Chellappa, Raja; Dattelbaum, Dana; Manner, Virginia; Mack, Nathan; Liu, Zhenxian

    2013-06-01

    2,4,6-trinitrotoluene (TNT) is a widely used explosive that is relatively insensitive to initiation by shock loading. While the detonation properties of TNT have been extensively reported, the high pressure-temperature (P - T) stability of TNT has not been investigated in detail. In addition, there are no studies that have determined the effects of pressure on the stability of the liquid phase. At ambient conditions, TNT crystallizes in a monoclinic lattice (space group P21 / a) , and our previous x-ray diffraction (XRD) measurements at room temperature suggested a phase transition to orthorhombic (space group Pca21) at ~20 GPa. In this work, we have performed in situ synchrotron XRD and vibrational spectroscopy measurements at various P - T conditions along isothermal and isobaric pathways to confirm previously reported phase transitions, and investigate phase stabilities up to 30 GPa and 500°C. Using all the available data, we have established the first comprehensive high P - T phase diagram of TNT, including the melting line as a function of pressure. While our synchrotron IR and Raman spectroscopy measurements indicate spectral changes at ~2 GPa, careful XRD measurements (hydrostatic, He medium and non-hydrostatic) reveal that the monoclinic phase is likely stable up to 20 GPa. We will present a self-consistent P - V - T equation of state derived from the reported structural and vibrational data.

  20. Aerobic biodegradation of 2,4,6-trinitrotoluene (TNT) by Bacillus cereus isolated from contaminated soil.

    PubMed

    Mercimek, H Aysun; Dincer, Sadık; Guzeldag, Gulcihan; Ozsavli, Aysenur; Matyar, Fatih

    2013-10-01

    In this study, biological degradation of 2,4,6-trinitrotoluene (TNT) which is very highly toxic environmentally and an explosive in nitroaromatic character was researched in minimal medium by Bacillus cereus isolated from North Atlantic Treaty Organization (NATO) TNT-contaminated soils. In contrast to most previous studies, the capability of this bacteria to transform in liquid medium containing TNT was investigated. During degradation, treatment of TNT was followed by high-performance liquid chromatography (HPLC) and achievement of degradation was calculated as percentage. At an initial concentration of 50 and 75 mg L(-1), TNT was degraded respectively 68 % and 77 % in 96 h. It transformed into 2,4-dinitrotoluene and 4-aminodinitrotoluene derivates, which could be detected as intermediate metabolites by using thin-layer chromatography and gas chromatography-mass spectrometry analyses. Release of nitrite and nitrate ions were searched by spectrophotometric analyses. Depending upon Meisenheimer complex, while nitrite production was observed, nitrate was detected in none of the cultures. Results of our study propose which environmental pollutant can be removed by using microorganisms that are indigenous to the contaminated site.

  1. Effect of ferrihydrite on 2,4,6-trinitrotoluene biotransformation by an aerobic yeast.

    PubMed

    Khilyas, Irina V; Ziganshin, Ayrat M; Pannier, Andy J; Gerlach, Robin

    2013-09-01

    This study investigated the impact of ferrihydrite on the pathway and rate of 2,4,6-trinitrotoluene (TNT) transformation by Yarrowia lipolytica AN-L15. The presence of ferrihydrite in the culture medium decreased the rate of TNT biotransformation but resulted in the accumulation of the same TNT metabolites as in the absence of ferrihydrite, albeit at slightly different concentrations. Transformation products observed included aromatic ring reduction products, such as hydride-Meisenheimer complexes, and nitro group reduction products, such as hydroxylamino- and amino-dinitrotoluenes. Independently of the presence of ferrihydrite the subsequent degradation of the hydride complex(es) resulted in the release of nitrite followed by its conversion to nitrate and nitric oxide at the low pH values observed during yeast cultivation. Nitric oxide generation was ascertained by electron spin resonance spectroscopy. In addition, increased Fe(3+)-reduction was observed in the presence of TNT and Y. lipolytica. This study demonstrates that in the presence of yeast cells, TNT-hydride complexes were formed at approximately the same level as in the presence of ferrihydrite, opening up the possibility of aromatic ring cleavage, instead of promoting the production of potentially toxic nitro group reduction products in the presence of iron minerals.

  2. Irreversible binding of biologically reduced 2,4,6-trinitrotoluene to soil

    SciTech Connect

    Achtnich, C.; Sieglen, U.; Knackmuss, H.J.; Lenke, H.

    1999-11-01

    To analyze the fate of 2,4,6-trinitrotoluene (TNT) and its reduction products, a TNT-contaminated soil was spiked with [ring-UL-{sup 14}C]TNT and treated in a laboratory slurry reactor. During an anaerobic/aerobic treatment, the total radioactivity measured in the supernatant and methanolic soil extracts decreased to 2%. The decrease corresponded to an increase of strongly bound radioactivity to the soil. Throughout the whole treatment process, mineralization of TNT was not observed. During the reductive process, unidentified polar substances increased to a maximum amount of 23.2% of the total radioactivity on the day after the start of the experiment. After the end of the anaerobic phase, still 9.7% of the radioactivity was found in this fraction. Only during the aerobic phase did the polar substances disappear completely. The irreversible character of the binding of the reduced metabolites of TNT to the soil was indicated by the failure of desorption even under rigorous and long-term extraction conditions. A significant release of radioactivity could be measured only by using high concentrations of HCl or EDTA. However, in none of the extracts were TNT or any reduced metabolites detected by HPLC and {sup 14}C-radiocounting. Size-exclusion chromatography of humic acids extracted from the treated soil indicated that the metabolites of TNT were evenly bound to the complete range of molecular size of the humic acids.

  3. Enhanced sensitivity of explosives in the Condensed Phase: 2,4,6-trinitrotoluene as a model

    NASA Astrophysics Data System (ADS)

    Zeiri, Yehuda; Furman, David; Dubnikova, Faina; Rom, Naomi; Hirshberg, Barak; Zybin, Sergey; Goddard, William A., , III; Kosloff, Ronnie

    2013-06-01

    This study is based on the results of Molecular Dynamics (MD) employing a reactive force field (ReaxFF) and electronic structure (DFT) calculations of 2,4,6-trinitrotoluene (TNT) decomposition and high temperatures and pressures. The sensitivity to decomposition shows a marked increase for the condense phase as compared with single molecule. The simulations suggest that bimolecular processes dominate the initial stages of decomposition. The DFT calculations used to explore the role of bimolecular pathways. These pathways are responsible to the ~23 kcal/mol reduction in the barrier height that lead to the enhanced sensitivity. These pathways involve (1) an H atom transfer between two neighboring TNT molecules in from the aromatic ring of one to one of the nitro groups of the other. The loss of the H atom promotes breaking the adjacent C-NO2, and (2) the H atom transfer to the NO2 leads subsequently to the formation of HONO and NO products. The thermal decomposition process was followed using the MD simulations for 400 ps to reach the final stable decomposition products. In addition to stable gas products, we obtained carbon clusters formed by the agglomeration of aromatic rings. The TNT decomposition mechanism is compared to that of other explosives.

  4. Transformation of 2,4,6-trinitrotoluene (TNT) by Raoultella terrigena.

    PubMed

    Claus, H; Bausinger, T; Lehmler, I; Perret, N; Fels, G; Dehner, U; Preuss, J; König, H

    2007-02-01

    Manufacture of nitroorganic explosives generates toxic wastes leading to contamination of soils and waters, especially groundwater. For that reason bacteria living in environments highly contaminated with 2,4,6-trinitrotoluene (TNT) and other nitroorganic compounds were investigated for their capacity for TNT degradation. One isolate, Raoultella terrigena strain HB, removed TNT at concentrations between 10 and 100 mg l(-1) completely from culture supernatants under optimum aerobic conditions within several hours. Only low concentrations of nutrient supplements were needed for the cometabolic transformation process. Radioactivity measurements with ring-labelled (14)C-TNT detected about 10-20% of the initial radioactivity in the culture supernatant and the residual 80-90% as water-insoluble organic compounds in the cellular pellet. HPLC analysis identified aminodinitrotoluenes (2-ADNT, 4-ADNT) and diaminonitrotoluenes (2,4-DANT) as the metabolites which remained soluble in the culture medium and azoxy-dimers as the main products in the cell extracts. Hence, the new isolate could be useful for the removal of TNT from contaminated waters.

  5. Initial reductive reactions in aerobic microbial metabolism of 2,4,6-trinitrotoluene.

    PubMed

    Vorbeck, C; Lenke, H; Fischer, P; Spain, J C; Knackmuss, H J

    1998-01-01

    Because of its high electron deficiency, initial microbial transformations of 2,4,6-trinitrotoluene (TNT) are characterized by reductive rather than oxidation reactions. The reduction of the nitro groups seems to be the dominating mechanism, whereas hydrogenation of the aromatic ring, as described for picric acid, appears to be of minor importance. Thus, two bacterial strains enriched with TNT as a sole source of nitrogen under aerobic conditions, a gram-negative strain called TNT-8 and a gram-positive strain called TNT-32, carried out nitro-group reduction. In contrast, both a picric acid-utilizing Rhodococcus erythropolis strain, HL PM-1, and a 4-nitrotoluene-utilizing Mycobacterium sp. strain, HL 4-NT-1, possessed reductive enzyme systems, which catalyze ring hydrogenation, i.e., the addition of a hydride ion to the aromatic ring of TNT. The hydride-Meisenheimer complex thus formed (H-TNT) was further converted to a yellow metabolite, which by electrospray mass and nuclear magnetic resonance spectral analyses was established as the protonated dihydride-Meisenheimer complex of TNT (2H-TNT). Formation of hydride complexes could not be identified with the TNT-enriched strains TNT-8 and TNT-32, or with Pseudomonas sp. clone A (2NT), for which such a mechanism has been proposed. Correspondingly, reductive denitration of TNT did not occur.

  6. Sonochemical synthesis of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB)

    SciTech Connect

    Lee, Kien-Yin

    1996-05-01

    The synthesis of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) from trichlorotrinitrobenzene (TCTNB) in toluene and ammonium hydroxide solution under the influence of ultrasonic waves was investigated. When the two-phase reaction mixture was irradiated with high intensity ultrasound at ambient temperature, fine-particle TATB (FP-TATB) was produced. This sonochemically produced TATB powder is lemon color in appearance and was analyzed to have the same explosive properties as reported in the literature. That is, it is insensitive to impact stimuli, and thermally stable. The median particle diameter of FP-TATB was calculated to be around 14 {mu}m, and the powder can be pressed to a density of 1.82 g/cm{sup 3} without a binder. The amination process is simple and requires neither the monitoring of the ammonia gas pressure nor the controlling of the reaction temperature during amination reaction, and we anticipate no problem in large scale production of FP-TATB.

  7. SAGE Analysis of Transcriptome Responses in Arabidopsis Roots Exposed to 2,4,6-Trinitrotoluene1

    PubMed Central

    Ekman, Drew R.; Lorenz, W. Walter; Przybyla, Alan E.; Wolfe, N. Lee; Dean, Jeffrey F.D.

    2003-01-01

    Serial analysis of gene expression was used to profile transcript levels in Arabidopsis roots and assess their responses to 2,4,6-trinitrotoluene (TNT) exposure. SAGE libraries representing control and TNT-exposed seedling root transcripts were constructed, and each was sequenced to a depth of roughly 32,000 tags. More than 19,000 unique tags were identified overall. The second most highly induced tag (27-fold increase) represented a glutathione S-transferase. Cytochrome P450 enzymes, as well as an ABC transporter and a probable nitroreductase, were highly induced by TNT exposure. Analyses also revealed an oxidative stress response upon TNT exposure. Although some increases were anticipated in light of current models for xenobiotic metabolism in plants, evidence for unsuspected conjugation pathways was also noted. Identifying transcriptome-level responses to TNT exposure will better define the metabolic pathways plants use to detoxify this xenobiotic compound, which should help improve phytoremediation strategies directed at TNT and other nitroaromatic compounds. PMID:14551330

  8. Prevalence of Sleep Disorders Among Children 4 - 6 Years Old in Tehran Province, Iran

    PubMed Central

    Ozgoli, Giti; Sheikhan, Zohre; Soleimani, Farin; Nasiri, Malihe; Amiri, Saba

    2016-01-01

    Background Sleep patterns may change over a person’s lifetime; however, the quantity and quality of sleep always depend on individual factors such as age, sex, and psychological and environmental factors. In children, sleep is as important as development. Quantitative sleep problems related to sleep onset and qualitative sleep disorders such as frequent awakenings may lead to insufficient sleep. Objectives This study aimed to assess the prevalence of sleep disorders among children 4 - 6 years old attending the health centers of Shahid Beheshti University of Medical Sciences, Tehran, Iran, in 2013. Patients and Methods This was a cross-sectional study on 400 children selected using a multistage sampling method. Data were collected by interviews. The questionnaire included two sections: a demographic section with questions about the demographic characteristics of the children and parents and a children’s sleep habit questionnaire (CSHQ). Data were analyzed by SPSS 16 and different statistical tests were used (P < 0.05). Results The mean age of the children was 64.27 ± 9.3 months. The prevalence of sleep disorders was 36.25%. Sleep disorders were significantly associated with age, height, body mass index, residence of children, father’s occupation, mother’s diseases, father’s drug abuse, and parents’ marital status (P < 0.05). Conclusions Sleep disorders in children threaten growth and development, and are dangerous for their health. Sleep disorders should be considered in the differential diagnosis of children’s learning and behavioral problems.

  9. Large magnetic field effect on the radical pair generated from the photo-induced electron transfer from skatole to 2,4,6-triphenyl pyrilium tetrafluoroborate in aqueous SDS micellar medium

    NASA Astrophysics Data System (ADS)

    Haldar, Mintu; Chowdhury, Mihir

    2000-03-01

    The effect of external magnetic field on the spin evolution of the radical pair (RP) generated from photo-induced electron transfer from skatole to 2,4,6-triphenyl pyrilium tetrafluoroborate in aqueous SDS micellar medium has been investigated. The yield of escape radicals gradually increases with increasing field and ultimately reaches saturation. The yield of escaped radicals at saturating fields is almost four times the corresponding zero-field value. At low fields the magnetic field dependence of the escape yield is ascribed to HFI-Zeeman competition and at relatively higher fields, to the relaxation mechanism induced by anisotropic HFI [δ(hfi)]. A saturation in MFE is observed at high fields, which is a consequence of the competition between the spin-rephasing process and the fast escape process.

  10. Nutritional status survey of children with autism and typically developing children aged 4-6 years in Heilongjiang Province, China.

    PubMed

    Sun, Caihong; Xia, Wei; Zhao, Yan; Li, Nannan; Zhao, Dong; Wu, Lijie

    2013-01-01

    Autism is a neurodevelopmental disability that may affect nutritional management of children with autism. This study aimed to compare the nutritional status of children with autism with that of typically developing children (aged 4-6 years) in China. Nutritional status was assessed by means of nutritional data, anthropometric data, biochemical assessment, physical examination for nutrient deficiencies and providing a questionnaire to parents. A total of fifty-three children with autism and fifty-three typically developing children were enrolled in this study. The parents were asked to complete the questionnaire regarding the eating behaviour and gastrointestinal symptoms of their children. They were also asked to provide a 3 d food diary. Children with autism exhibited several abnormalities in terms of eating behaviour and gastrointestinal symptoms. The levels of vitamins A and B6, Zn and Ca intakes were <80 % of the dietary reference intakes in both groups. In addition, the proportions of vitamin C and Ca intake deficiencies in the autism group were significantly higher than those in the control group. Serum Zn level was less than the normal reference range in both the groups. Serum Ca, vitamin A and folate levels in children with autism were significantly lower when compared with children without autism. According to the anthropometric data, the mean BMI, weight-for-height Z-score (Z WH) and BMI for age Z-score (Z BMIA) of children with autism were significantly higher than those of the typically developing children. Thus, nutritional inadequacies were observed in children with autism and typically developing children in China, which were, however, more pronounced among children with autism.

  11. cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5-d]imidazole (BCHMX), its properties and initiation reactivity.

    PubMed

    Klasovitý, Dusan; Zeman, Svatopluk; Růzicka, Ales; Jungová, Marcela; Rohác, Michal

    2009-05-30

    Using the (15)N NMR chemical shifts of nitrogen atoms in nitramino groups of cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5-d]imidazole (bicyclo-HMX or BCHMX) and additional 10 nitramines, we have assessed its reactivity in detonation, under the influence of impact, and by action of electric spark. It is stated that the thermal stability of BCHMX is higher than that of 1,3,5-trinitro-1,3,5-triazinane (RDX). The longest NN bond in the BCHMX molecule (1.412(4)A) is the cause for its higher impact reactivity, which is at the level of that of penterythritol tetranitrate (PETN). In the experimentally determined detonation velocity, BCMX can be slightly better performing than RDX. From the standpoint of friction sensitivity, BCHMX is similar to 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX). Attention was also focused on the solubility-temperature dependence of BCHMX in acetone, acetonitrile, ethyl acetate, dimethyl sulfoxide, tetrahydrofurane, and nitromethane. X-ray crystallographic study of BCHMX (C(4)H(6)N(8)O(8), M(r)=294.17), has been carried out at the temperature of 150K with the following results: a=8.5430(8), b=6.9480(6), c=8.7780(8)A, alpha=90.0(7) degrees , beta=102.452(11) degrees , gamma=90.0(9) degrees , V=508.777(8)A(3), Z=2, D(x)=1.920 g cm(-3), lambda(Mo Ka)=0.71073A, micro=0.169 cm(-1), F(000)=856, final R=0.0414 for 1254 independent observed reflections. In the BCHMX crystal there were found more short contacts in the molecular crystal of BCHMX data of Gilardi creating extensive supramolecular architecture.

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

    PubMed

    Api, A M; San, R H

    1999-10-29

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

  13. Photoluminescence properties of Eu(3+)/ Sm(3+) activated CaZr4(PO4)6 phosphors.

    PubMed

    Nair, Govind B; Dhoble, S J

    2016-09-01

    Solid state reaction method was employed for the synthesis of a series of CaZr4(PO4)6: Eu(3+)/Sm(3+) phosphors. The red-emitting CaZr4(PO4)6:Eu(3+) phosphors can be efficiently excited at 396 nm and thereby, exhibit a strong red luminescence predominantly corresponding to the electric dipole transition at 615 nm. Under 405 nm excitation, CaZr4(PO4)6:Sm(3+) phosphors display orange emission with color temperatures approximately around 2200 K. The acquired results reveal that CaZr4(PO4)6: RE(3+) (RE = Eu, Sm) phosphors could be potential candidates for red and orange emitting phosphor, respectively, for UV/blue-pump LEDs. PMID:27411525

  14. Photoluminescence properties of Eu(3+)/ Sm(3+) activated CaZr4(PO4)6 phosphors.

    PubMed

    Nair, Govind B; Dhoble, S J

    2016-09-01

    Solid state reaction method was employed for the synthesis of a series of CaZr4(PO4)6: Eu(3+)/Sm(3+) phosphors. The red-emitting CaZr4(PO4)6:Eu(3+) phosphors can be efficiently excited at 396 nm and thereby, exhibit a strong red luminescence predominantly corresponding to the electric dipole transition at 615 nm. Under 405 nm excitation, CaZr4(PO4)6:Sm(3+) phosphors display orange emission with color temperatures approximately around 2200 K. The acquired results reveal that CaZr4(PO4)6: RE(3+) (RE = Eu, Sm) phosphors could be potential candidates for red and orange emitting phosphor, respectively, for UV/blue-pump LEDs.

  15. Quantum mechanical and experimental analyses of TNT metabolite 2-hydroxylamino-4,6-dinitrotoluene

    NASA Astrophysics Data System (ADS)

    Junk, Thomas; Liu, Yuemin; Li, Zhong; Perkins, Richard; Liu, Yucheng

    2015-01-01

    In this study, a combined quantum mechanical and experimental analyses were performed to investigate crystal structure of the immediate degradation product of TNT, 2-hydroxylamino-4,6-dinitrotoluene (2-HADNT) and to reveal its important chemical properties. Leakage of 2-HADNT has caused serious environmental pollution and therefore raises widespread concerns. In the quantum mechanical analysis, the B3LYP/6-311+G**, B3LYP/aug-c-pVDZ, M06HF/aug-cc-pVDZ, and MP2/aug-cc-pVDZ methods were employed for geometrical optimization and single point calculations of chemical properties of the compound. Such properties include highest unoccupied molecular orbitals (HOMO) - lowest occupied molecular orbitals (LUMO) separation, dipole moment, atomization energy, and vibrational frequencies. Experimental analysis and validation showed that the energy minimized structures acquired from the quantum mechanical analysis were very similar to those obtained by X-ray crystallography. The 6-NO2 groups twist out of plane with respect to the benzene ring in both the crystallographic and energy minimized structures. The 4-NO2 group exhibits co-planarity with the phenyl ring in both the crystallographic and energy minimized structures as well. Unlike TNT, however, the energy barrier to orthogonal conformation is only 3.8 kcal/mol. In addition, considerable discrepancies between results obtained from the MP2 and B3LYP methods were observed, which suggest that it has to be very careful when applying B3LYP method to study such class of compounds. Through this study, a more accurate description of the chemical properties of dispersion-dominated aromatic systems was acquired. The chemical properties found from this study can help researchers to better understand the compound of 2-HADNT and to develop effective management plans for such compound so as to minimize its impact on the environment.

  16. Biodegradation of TNT (2,4,6-trinitrotoluene) by Phanerochaete chrysosporium.

    PubMed Central

    Fernando, T; Bumpus, J A; Aust, S D

    1990-01-01

    Extensive biodegradation of TNT (2,4,6-trinitrotoluene) by the white rot fungus Phanerochaete chrysosporium was observed. At an initial concentration of 1.3 mg/liter, 35.4 +/- 3.6% of the [14C]TNT was degraded to 14CO2 in 18 days. The addition of glucose 12 days after the addition of TNT did not stimulate mineralization, and, after 18 days of incubation with TNT only, about 3.3% of the initial TNT could be recovered. Mineralization of [14C]TNT adsorbed on soil was also examined. Ground corncobs served as the nutrient for slow but sustained degradation of [14C]TNT to 14CO2 such that 6.3 +/- 0.6% of the [14C]TNT initially present was converted to 14CO2 during the 30-day incubation period. Mass balance analysis of liquid cultures and of soil-corncob cultures revealed that polar [14C]TNT metabolites are formed in both systems, and high-performance liquid chromatography analyses revealed that less than 5% of the radioactivity remained as undegraded [14C]TNT following incubation with the fungus in soil or liquid cultures. When the concentration of TNT in cultures (both liquid and soil) was adjusted to contamination levels that might be found in the environment, i.e., 10,000 mg/kg in soil and 100 mg/liter in water, mineralization studies showed that 18.4 +/- 2.9% and 19.6 +/- 3.5% of the initial TNT was converted to 14CO2 in 90 days in soil and liquid cultures, respectively. In both cases (90 days in water at 100 mg/liter and in soil at 10,000 mg/kg) approximately 85% of the TNT was degraded. These results suggest that this fungus may be useful for the decontamination of sites in the environment contaminated with TNT. PMID:2383008

  17. Measurements of coronal Faraday rotation at 4.6 R {sub ☉}

    SciTech Connect

    Kooi, Jason E.; Fischer, Patrick D.; Buffo, Jacob J.; Spangler, Steven R.

    2014-03-20

    Many competing models for the coronal heating and acceleration mechanisms of the high-speed solar wind depend on the solar magnetic field and plasma structure in the corona within heliocentric distances of 5 R {sub ☉}. We report on sensitive Very Large Array (VLA) full-polarization observations made in 2011 August, at 5.0 and 6.1 GHz (each with a bandwidth of 128 MHz) of the radio galaxy 3C 228 through the solar corona at heliocentric distances of 4.6-5.0 R {sub ☉}. Observations at 5.0 GHz permit measurements deeper in the corona than previous VLA observations at 1.4 and 1.7 GHz. These Faraday rotation observations provide unique information on the magnetic field in this region of the corona. The measured Faraday rotation on this day was lower than our a priori expectations, but we have successfully modeled the measurement in terms of observed properties of the corona on the day of observation. Our data on 3C 228 provide two lines of sight (separated by 46'', 33,000 km in the corona). We detected three periods during which there appeared to be a difference in the Faraday rotation measure between these two closely spaced lines of sight. These measurements (termed differential Faraday rotation) yield an estimate of 2.6-4.1 GA for coronal currents. Our data also allow us to impose upper limits on rotation measure fluctuations caused by coronal waves; the observed upper limits were 3.3 and 6.4 rad m{sup –2} along the two lines of sight. The implications of these results for Joule heating and wave heating are briefly discussed.

  18. Degradation products of 2,4,6-Trinitrotoluene by a microbial consortia

    SciTech Connect

    Ortiz, O.; Parker, C.; Bender, J.

    1995-12-01

    Remediation of contaminated soils can be accomplished using microbial species. Of particular interest is the remediation of explosive contaminated soils. A microbial consortia has been developed which removes TNT by an unexplained mechanism. Our goal is to understand the degradation of TNT by this microbial mat. Constructed mats have been generated in our laboratory by enriching water with ensiled grass and adding specific microbial components for organic degradation. Microbial mats are natural mixed microbial communities dominated by cyanobacterias (blue-green algae). In this research, degradation products of TNT have been identified using GC/MS. Ninety-seven percent of TNT (1000 mg/L), was removed in < 1 day by floating mats placed over TNT-contaminated water in quiescent ponds. Metabolites of TNT, 2, 4-Dinitro-6 amminotoluene and 2-Nitro-4,6 diaminotoluene has been observed after 1 day of mat treatment. A mechanism is postulated for this degradation showing that two of the nitro groups of the TNT molecule are being reduced to amino groups systematically. Anoxic zones in the mat, containing sulfur-reducing bacteria, may account for the reduction of TNT. GC/MS shows significant decreases in metabolite concentrations in 4-7 days, indicating continued degradation of TNT. It has been found by toxicity assays that these metabolites appeared to be nontoxic and nonmutagenic. These results suggest that floating microbial mats may be useful for the decontamination of sites in the environment contaminated with TNT. Further studies using {sup 13}C TNT will focus on the fate of the carbon, to determine the intermediates products prior to transformations into hydrocarbons or utilization by the bacteria consortia.

  19. 2,4,6-Trichlorophenol mediated increases in extracellular peroxidase activity in three species of Lemnaceae.

    PubMed

    Biswas, Dilip K; Scannell, Gillian; Akhmetov, Nurlan; Fitzpatrick, Dara; Jansen, Marcel A K

    2010-11-01

    Chlorinated phenols, or chlorophenols, are persistent priority pollutants that are widespread in the environment. Class III peroxidases are well-characterised plant enzymes that can catalyse the oxidative dechlorination of chlorophenols. Expression of these enzymes by plants is commonly associated with plant stress, therefore limiting scope for phytoremediation. In this study, we have quantitatively compared peroxidase activity and phytotoxicity as a function of 2,4,6-trichlorophenol (TCP) concentration in three species of Lemnaceae; Lemna minor, Lemna gibba and Landoltia punctata. Effects of TCP on the growth rates of the three species differed considerably with L. punctata being the most tolerant species. TCP also affected photosynthetic parameters, causing a decrease in open photosystem II reaction centres (qP) and, in L. punctata only, a decrease in non-photochemical quenching (qN). In parallel, TCP exposure resulted in increased peroxidase activity in all three species. Peroxidase activity in L. minor and L. gibba displayed an inverse relationship with biomass accumulation, i.e. the more growth reduction the more peroxidase activity. In contrast, induction of peroxidase activity in L. punctata was bi-phasic, with a TCP-induced activity peak at concentrations that had no major effect on growth, and further induction under phytotoxic concentrations. The mechanism by which L. punctata recognises and responds to low concentrations of an anthropogenic compound, in the absence of wide-ranging stress, remains enigmatic. However, we conclude that this "window" of peroxidase production in the absence of major growth inhibition offers potential for the development of sustainable, peroxidise-mediated phytoremediation systems. PMID:20810175

  20. Magnetic Stratigraphy and Relative Paleointensity from IODP Site U1313 from 2.4-6 Ma

    NASA Astrophysics Data System (ADS)

    Evans, H. F.; Acton, G. D.; Guyodo, Y.; Channell, J. E.; Ohno, M.; Kanamatsu, T.

    2006-12-01

    IODP Expedition 306 to the North Atlantic drilled three sites in the Spring of 2005 including Site U1313 which is a re-occupation of DSDP Site 607. A complete spliced composite section was obtained down to 300 mcd (meters composite depth) from 4 holes drilled at the site. U-channel samples were collected for the upper ~280 meters of the section. The 2.4-6 Ma interval has produced a magnetic reversal stratigraphy that defines all the subchrons of the Gauss and Gilbert chrons. The Gauss and Gilbert chrons are ~ 45 meters and ~100 meters thick respectively and have mean sedimentation rates of 4.5 cm/kyr. The sediments carry a weak low- coercivity magnetization most likely carried by magnetite. In the upper part of the section (0-130 mcd) the sediments show a cyclic alternation between nannofossil oozes and silty-clay nannofossil ooze. The light nannofossil oozes represent interglacials while the darker silty clay nannofossil oozes represent the glacials. The sediment in the lower part of the section (130-300 mcd) consists of white nannofossil oozes. The volume magnetic susceptibility, although very weak when measured on the u-channel samples, is reproducible as demonstrated by replicate measurements. Natural gamma data collected shipboard on the whole core and magnetic susceptibility from u-channel samples can be correlated to a benthic oxygen isotope stack. The resulting age model based on this correlation and the reversal chronology is applied to the normalized remanence record between 2.4 and 4 Ma. Three relative paleointensity proxies have been calculated: NRM/ARM, NRM/IRM and the slope of NRM/ARM-acquisition. Consistency among the three proxies and acceptable correlation to Pacific records of the same age implies that the site has yielded useful a paleointensity record for the Gauss and Gilbert chrons.

  1. Bioremediation of 2,4,6-trinitrotoluene by bacterial nitroreductase expressing transgenic aspen.

    PubMed

    Van Dillewijn, Pieter; Couselo, José L; Corredoira, Elena; Delgado, Antonio; Wittich, Rolf-Michael; Ballester, Antonio; Ramos, Juan L

    2008-10-01

    Trees belonging to the genus Populus are often used for phytoremediation due to their deep root formation, fast growth and high transpiration rates. Here, we study the capacity of transgenic hybrid aspen (Populus tremula x tremuloides var. Etropole) which expresses the bacterial nitroreductase gene, pnrA, to tolerate and take-up greater amounts of the toxic and recalcitrant explosive, 2,4,6-trinitrotoluene (TNT) from contaminated waters and soil. Transgenic aspen tolerate up to 57 mg TNT/L in hydroponic media and more than 1000 mg TNT/ kg soil, whereas the parental aspen could not endure in hydroponic culture with more than 11 mg TNT/L or soil with more than 500 mg TNT/kg. Likewise, the phytotoxicological limit for transgenic plants to a constant concentration of TNT was 20 mg TNT/L while wild-type plants only tolerated 10 mg TNT/L. Transgenic plants also showed improved uptake of TNT over wild-type plants when the original TNT concentration was above 35 mg TNT/L in liquid media or 750 mg TNT/kg in soil. Assays with 13C-labeled TNT show rapid adsorption of TNT to the root surface followed by a slower entrance rate into the plant. Most of the 13C-carbon from the labeled TNT taken up bythe plant (> 95%) remains in the root with little translocation to the stem. Altogether, transgenic aspen expressing pnrA are highly interesting for phytoremediation applications on contaminated soil and underground aquifers. PMID:18939578

  2. Fate and metabolism of [15N]2,4,6-trinitrotoluene in soil.

    PubMed

    Weiss, Martin; Geyer, Roland; Russow, Rolf; Richnow, Hans H; Kästner, Matthias

    2004-08-01

    The fates of the labels from [14C] and [15N] trinitrotoluene were analyzed in bioreactors under aerobic conditions in soil treated by a fungal bioremediation process with Stropharia rugosoannulata and in control soil. Up to 17.5% of the 15N label had a different fate than the 14C label. Three N-mineralization processes were identified in detailed experiments with [15N]TNT. About 2% of the 15N label was found as NO3- and NH4+, showing simultaneous processes of direct TNT denitration (I) and reduction with cleavage of the amino groups (II). The enrichment of NO2-/NO3- (up to 7.5 atom% 15N abundance) indicates the formation of Meisenheimer complexes with a denitration of [15N]TNT. A 1.4% of the label was found distributed between N2O and N2. However, the 15N enrichment of the N2O (up to 38 atom%) demonstrated that both N atoms were generated from the labeled TNT and clearly indicates a novel formation process (III). We propose, as an explanation, the generation of N2O by cleavage from condensed azoxy metabolites. In addition, 1.7% of the 15N label was detected as biogenic amino acids in the wheat straw containing the fungus. Overall, 60 to 85% of the applied [15N]TNT was degraded and 52 to 64% was found as nonextractable residues in the soil matrix. Three percent was detected as 2-amino-4,6-dinitrotoluene and 4-amino-2,6-dinitrotoluene.

  3. Sensitive electrochemical immunoassay for 2,4,6-trinitrotoluene based on functionalized silica nanoparticle labels

    SciTech Connect

    Wang, Jun; Liu, Guodong; Wu, Hong; Lin, Yuehe

    2008-03-03

    We present a poly(guanine)-functionalized silica nanoparticle (NP) label-based electrochemical immunoassay for sensitively detecting 2,4,6-trinitrotoluene (TNT). This immunoassay takes advantage of magnetic bead–based platform for competitive displacement immunoreactions and separation, and use electroactive nanoparticles as labels for signal amplification. For this assay, anti-TNT-coated magnetic beads interacted with TNT analog-conjugated poly(guanine)-silica NPs and formed analog-anti-TNT immunocomplexes on magnetic beads. The immunocomplexes coated magnetic beads were exposed to TNT samples, which resulted in displacing the analog conjugated poly(guanine) silica NPs into solution by TNT. In contrast, there are no guanine residues releasing into the solution in the absence of TNT. The reaction solution was then separated from the magnetic beads and transferred to the electrode surface for electrochemical measurements of guanine oxidation with Ru(bpy)32+ as mediator. The sensitivity of this TNT assay was greatly enhanced through dual signal amplifications: 1) a large amount of guanine residues on silica nanoparticles is introduced into the test solution by displacement immunoreactions and 2) a Ru(bpy)32+-induced guanine catalytic oxidation further enhances the electrochemical signal. Some experimental parameters for the nanoparticle label-based electrochemical immunoassay were studied and the performance of this assay was evaluated. The method is found to be very sensitive and the detection limit of this assay is ~ 0.1 ng mL-1 TNT. The electrochemical immunoassay based on the poly[guanine]-functionalized silica NP label offers a new approach for sensitive detection of explosives.

  4. Gas phase detection of explosives such as 2,4,6-trinitrotoluene by molecularly imprinted polymers.

    PubMed

    Bunte, Gudrun; Hürttlen, Jürgen; Pontius, Heike; Hartlieb, Kerstin; Krause, Horst

    2007-05-15

    Fast, reliable and inexpensive analytical techniques for trace detection of explosive components are in high demand. Our approach is to develop specific sensor coating materials based on molecularly imprinted polymers (MIPs). Despite the known inhibition of radical polymerisations by nitro groups and the known shrinkage of the polymer lattice during/after drying we were able to synthesize particulate MIPs by suspension polymerisation as well as thin MIP coatings by direct surface polymerisation on quartz crystal microbalances (QCM). The best method to purify the porous beads was Soxhlet extraction followed by supercritical carbon dioxide extraction (SFE with sc-CO2) at mild conditions (150 bar, 50 degrees C). At least a removal of >99.7% of the template was achieved. Performance tests of TNT imprinted polymer beads showed that acrylamide (AA) and more pronounced also methacrylic acid (MAA) possessed an enhanced adsorption tendency for gaseous TNT. An adsorption of 2,4-DNT, dinitrotoluene, by these MIPs was not detected. Using 2,4-DNT as template and methacrylamide, MAAM, a positive imprint effect for gaseous 2,4-DNT was achieved with no measurable cross-sensitivity for 2,4,6-TNT. The thin MIP coatings directly synthesized on the QCMs showed thicknesses of 20 to up to 500 nm. Preliminary screening experiments were performed for five different monomers and three different solvents (acetonitrile, chloroform and dimethylformamide). Best adsorption properties for TNT vapour until now showed a PAA-MIP synthesized with chloroform. Direct measurements of the mass attachment, respectively frequency decrease of the coated QCMs during vapour treatment showed a TNT-uptake of about 150 pg per microg MIP per hour. Results look worthy for further studies.

  5. Identification and modulatory activity assessment of 2-hydroxy-3,4,6-trimethoxyacetophenone isolated from croton anisodontus müll. Arg.(euphorbiaceae).

    PubMed

    Oliveira, Maria T A; Teixeira, Alexandre M R; Coutinho, Henrique D M; Menezes, Irwin R A; Sena, Diniz M; Santos, Hélcio S; de Mesquita, Bruna M; Albuquerque, Maria R J R; Bandeira, Paulo N; Braz-Filho, Raimundo

    2014-05-01

    The n-hexane extract of the stem bark of Croton anisodontus yielded 2-hydroxy-3,4,6-trimethoxyacetophenone, a well-known substance, but isolated from this species for the first time. The antimicrobial and modulatory activities of the compound towards Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, C. krusei and C. tropicalis strains were assessed. Antibiotics such as amikacin, gentamicin and neomycin were used in a sub-inhibitory concentration. Significant activity was observed towards P. aeruginosa and S. aureus 358, with p < 0.001 in association with amikacin. The present results place C anisodontus as an alternative source of 2-hydroxy-3,4,6-trimethoxyacetophenone with antibacterial potential.

  6. Application of Novel Amino-Functionalized NZVI@SiO2 Nanoparticles to Enhance Anaerobic Granular Sludge Removal of 2,4,6-Trichlorophenol

    PubMed Central

    Guan, Zeyu; Wan, Jinquan; Ma, Yongwen; Wang, Yan; Shu, Yajie

    2015-01-01

    A novel amino-functionalized silica-coated nanoscale zerovalent iron (NZVI@SiO2-NH2) was successfully synthesized by using one-step liquid-phase method with the surface functionalization of nanoscale zerovalent iron (NZVI) to enhance degradation of chlorinated organic contaminants from anaerobic microbial system. NZVI@SiO2-NH2 nanoparticles were synthesized under optimal conditions with the uniform core-shell structure (80–100 nm), high loading of amino functionality (~0.9 wt%), and relatively large specific surface area (126.3 m2/g). The result demonstrated that well-dispersed NZVI@SiO2-NH2 nanoparticle with nFe0-core and amino-functional silicon shell can effectively remove 2,4,6-trichlorophenol (2,4,6-TCP) in the neutral condition, much higher than that of NZVI. Besides, the surface-modified nanoparticles (NZVI@SiO2-NH2) in anaerobic granule sludge system also showed a positive effect to promote anaerobic biodechlorination system. More than 94.6% of 2,4,6-TCP was removed from the combined NZVI@SiO2-NH2-anaerobic granular sludge system during the anaerobic dechlorination processes. Moreover, adding the appropriate concentration of NZVI@SiO2-NH2 in anaerobic granular sludge treatment system can decrease the toxicity of 2,4,6-TCP to anaerobic microorganisms and improved the cumulative amount of methane production and electron transport system activity. The results from this study clearly demonstrated that the NZVI@SiO2-NH2/anaerobic granular sludge system could become an effective and promising technology for the removal of chlorophenols in industrial wastewater. PMID:26060427

  7. Application of Novel Amino-Functionalized NZVI@SiO2 Nanoparticles to Enhance Anaerobic Granular Sludge Removal of 2,4,6-Trichlorophenol.

    PubMed

    Guan, Zeyu; Wan, Jinquan; Ma, Yongwen; Wang, Yan; Shu, Yajie

    2015-01-01

    A novel amino-functionalized silica-coated nanoscale zerovalent iron (NZVI@SiO2-NH2) was successfully synthesized by using one-step liquid-phase method with the surface functionalization of nanoscale zerovalent iron (NZVI) to enhance degradation of chlorinated organic contaminants from anaerobic microbial system. NZVI@SiO2-NH2 nanoparticles were synthesized under optimal conditions with the uniform core-shell structure (80-100 nm), high loading of amino functionality (~0.9 wt%), and relatively large specific surface area (126.3 m(2)/g). The result demonstrated that well-dispersed NZVI@SiO2-NH2 nanoparticle with nFe(0)-core and amino-functional silicon shell can effectively remove 2,4,6-trichlorophenol (2,4,6-TCP) in the neutral condition, much higher than that of NZVI. Besides, the surface-modified nanoparticles (NZVI@SiO2-NH2) in anaerobic granule sludge system also showed a positive effect to promote anaerobic biodechlorination system. More than 94.6% of 2,4,6-TCP was removed from the combined NZVI@SiO2-NH2-anaerobic granular sludge system during the anaerobic dechlorination processes. Moreover, adding the appropriate concentration of NZVI@SiO2-NH2 in anaerobic granular sludge treatment system can decrease the toxicity of 2,4,6-TCP to anaerobic microorganisms and improved the cumulative amount of methane production and electron transport system activity. The results from this study clearly demonstrated that the NZVI@SiO2-NH2/anaerobic granular sludge system could become an effective and promising technology for the removal of chlorophenols in industrial wastewater.

  8. Synthesis and evaluation of a radioiodinated 4,6-diaryl-3-cyano-2-pyridinone derivative as a survivin targeting SPECT probe for tumor imaging.

    PubMed

    Fuchigami, Takeshi; Mizoguchi, Tatsuya; Ishikawa, Natsumi; Haratake, Mamoru; Yoshida, Sakura; Magata, Yasuhiro; Nakayama, Morio

    2016-02-01

    Survivin is overexpressed in most of the cancerous tissues but not in terminally differentiated normal tissues, making it an attractive target for diagnosis and therapy of various types of cancers. In this study, we aimed to develop 4,6-diaryl-3-cyano-2-pyridinone (DCP) derivatives, as novel cancer imaging probes that target survivin. Chloro and iodo analogs of DCP (CDCP and IDCP, respectively) were successfully synthesized by using a previously unreported carbon monoxide-free procedure. IDCP exhibited a slightly higher binding affinity for recombinant human survivin (Kd=34 nM) than that of CDCP (Kd=44 nM). Fluorescence staining indicated that both CDCP and IDCP showed high signals in MDA-MB-231 cells with high levels of survivin expression. Significantly low fluorescent signals were observed in MCF-10A cells, which showed low levels of survivin expression. [(125)I]IDCP was synthesized for the application of IDCP to single photon emission computed tomography (SPECT) imaging. Quantitative in vitro binding of [(125)I]IDCP in cell cultures showed results consistent to those observed after fluorescent staining. In vivo biodistribution studies in tumor-bearing mice demonstrated that the tumor uptake of [(125)I]IDCP increased gradually with time and was 0.65% injected dose per gram (% ID/g) at 180 min. The maximum tumor/blood and tumor/muscle ratio at 60 min were 0.87 and 2.27, respectively, indicating inadequate [(125)I]IDCP accumulation in tumors necessary for in vivo imaging. Although further structural modifications are necessary to improve pharmacokinetic properties of IDCP, this study demonstrates the feasibility of using the DCP backbone as a scaffold for the development of survivin-targeting tumor imaging probes. PMID:26733475

  9. Extraction-less, rapid assay for the direct detection of 2,4,6-trichloroanisole (TCA) in cork samples.

    PubMed

    Apostolou, Theofylaktos; Pascual, Nuria; Marco, M-Pilar; Moschos, Anastassios; Petropoulos, Anastassios; Kaltsas, Grigoris; Kintzios, Spyridon

    2014-07-01

    2,4,6-trichloroanisole (TCA), the cork taint molecule, has been the target of several analytical approaches over the few past years. In spite of the development of highly efficient and sensitive tools for its detection, ranging from advanced chromatography to biosensor-based techniques, a practical breakthrough for routine cork screening purposes has not yet been realized, in part due to the requirement of a lengthy extraction of TCA in organic solvents, mostly 12% ethanol and the high detectability required. In the present report, we present a modification of a previously reported biosensor system based on the measurement of the electric response of cultured fibroblast cells membrane-engineered with the pAb78 TCA-specific antibody. Samples were prepared by macerating cork tissue and mixing it directly with the cellular biorecognition elements, without any intervening extraction process. By using this novel approach, we were able to detect TCA in just five minutes at extremely low concentrations (down to 0.2 ppt). The novel biosensor offers a number of practical benefits, including a very considerable reduction in the total assay time by one day, and a full portability, enabling its direct employment for on-site, high throughput screening of cork in the field and production facilities, without requiring any type of supporting infrastructure.

  10. Identification, Biosynthesis, and Function of 1,3,4,6-Hexanetetracarboxylic Acid in Methanobacterium thermoautotrophicum ΔH

    PubMed Central

    Gorkovenko, Alexander; Roberts, Mary F.; White, Robert H.

    1994-01-01

    An unusual compound, 1,3,4,6-hexanetetracarboxylic acid, was identified by 1H and 13C two-dimensional nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry as one of the major components of the small-molecule pool in Methanobacterium thermoautotrophicum ΔH under optimal conditions of cell growth. Incorporation of 13C- and 2H-labeled acetates was consistent with the biosynthesis of this tetracarboxylic acid from α-ketoglutarate, two molecules of acetyl-coenzyme A, and one molecule of CO2, as established for the tetracarboxylic acid moiety of methanofuran. 13CO2 pulse- 12CO2 chase methodology was used to establish the turnover rate for this compound. In contrast to the two other major solutes in this bacterium, cyclic 2,3-diphosphoglycerate and glutamate, which are key metabolic intermediates, this free tetracarboxylic acid was metabolically inactive, with a half-life that exceeded the cell doubling time. Hence, this molecular pool cannot serve as a metabolic intermediate in cell biosynthesis. The functional role of free tetracarboxylate as a conservative part of a system that maintains high positive internal osmotic pressure in this bacterium is proposed. PMID:16349232

  11. Shock induced sub-detonation chemical reactions in 1,3,5-triamino-2,4,6-trinitrobenzene

    SciTech Connect

    Oestmark, H.

    1996-05-01

    The technique of combining slapper ignition with fast (12 {mu}s/scan) time-of-flight mass spectroscopy has been used for studying the early shock-induced decomposition of TATB (1,3,5-triamino-2,4,6-trinitrobenzene). By varying the slapper energy, and hence the shock intensity, it was possible to vary the degree of reaction from a weak detonation to full detonation. As the slapper energy was lowered, several larger mass fragments were detected, e.g. m/z242. This indicates that it is possible to detect early decomposition products using this technique. The same set of experiments was also conducted on isotopically labelled TATB (TATB{minus}{sup 15}N{sub 6}) where the corresponding peak occurred at m/z248. From this it was concluded that the peak resulted from a shock-induced elimination of oxygen, and hence that the early decomposition is a conversion of a nitro group to a nitroso group. {copyright} {ital 1996 American Institute of Physics.}

  12. 2,4,6-trinitrophenyl-amino acid derivatives as spectrophotometric reagents for sulfur dioxide. [Using sodium sulfite

    SciTech Connect

    Al-Hajjaji, M.A.

    1984-01-01

    A spectrophotometric method for sulfur dioxide determination was explored on the basis of its complexation with TNP-amino acid derivatives forming an orange colored 1:1 complex with an increase in absorbance at 420 nm. TNP-glycine, TNP-threonine, TNP-serine and TNP-histidine (TNP-(2,4,6-trinitrophenyl-)) were investigated. The color development was instantaneous and the absorbance remained unchanged even after 24 h of mixing when kept in the dark. Linear calibration graphs (0-5 x 10/sup -5/M sulfite ions) were obtained at optimal reaction conditions of 7 x 10/sup -5/M TNP-amino acid and pH 8.0 phosphate buffer (0.05 M). The investigation of the effect of several diverse ions revealed an interference by sulfide and mercury ions at concentration levels of 10/sup -4/M. The standard deviation of determining 3 x 10/sup -5/M sulfite solution (10 times) was 1.474 x 10/sup -7/M. 22 references, 2 figures, 1 table.

  13. The renaissance of 2,4,6-tris(2-pyrimidyl)-1,3,5-triazine (TPymT) coordination chemistry.

    PubMed

    Safin, Damir A; Frost, Jamie M; Murugesu, Muralee

    2015-12-21

    In this perspective we report on recently accumulated data on the synthesis and coordination chemistry of 2,4,6-tris(2-pyrimidyl)-1,3,5-triazine (TPymT). Although a highly attractive ligand, owing to the presence of three fused terpyridine-like coordination pockets, the coordination chemistry of TPymT has something of a chequered past. This can principally be attributed to the hydrolysis of the ligand, which readily occurs under mild conditions. Thus, after first being synthesised in 1959 it had only been used a handful of times to synthesise coordination compounds until we began reinvestigating its chemistry in early 2013. Despite the significant challenges associated with its use, our work over the past two years has demonstrated that coordination chemistry with TPymT is indeed possible. Herein, we describe an overview of this body of work as it stands, and discuss its potential impact in a variety of areas including porous materials, catalysis and crystal engineering.

  14. Structural Studies of FlaA1 from Helicobacter Pylori Reveal the Mechanism for Inverting 4,6-dehydratase Activity

    SciTech Connect

    Ishiyama,N.; Creuzenet, C.; Miller, W.; Demendi, M.; Anderson, E.; Harauz, G.; Lam, J.; Berghuis, A.

    2006-01-01

    FlaA1 from the human pathogen Helicobacter pylori is an enzyme involved in saccharide biosynthesis that has been shown to be essential for pathogenicity. Here we present five crystal structures of FlaA1 in the presence of substrate, inhibitors, and bound cofactor, with resolutions ranging from 2.8 to 1.9 {angstrom}. These structures reveal that the enzyme is a novel member of the short-chain dehydrogenase/reductase superfamily. Additional electron microscopy studies show the enzyme to possess a hexameric doughnut-shaped quaternary structure. NMR analyses of 'real time' enzyme-substrate reactions indicate that FlaA1 is a UDP-GlcNAc-inverting 4,6-dehydratase, suggesting that the enzyme catalyzes the first step in the biosynthetic pathway of a pseudaminic acid derivative, which is implicated in protein glycosylation. Guided by evidence from site-directed mutagenesis and computational simulations, a three-step reaction mechanism is proposed that involves Lys-133 functioning as both a catalytic acid and base.

  15. Adsorption of 2,4,6-trinitrotoluene and 4-amino-2,6-dinitrotoluene in two soil environments

    SciTech Connect

    Wood, A.J.; Tiller, C.L.

    1996-10-01

    Soil contamination by 2,4,6-trinitrotoluene (TNT) and its byproducts is common among Army Ammunition Plants (AAPs). The purpose of this research is to quantify the behavior of TNT in the Alabama AAP soil environment. Uncontaminated soil collected from two different depths at the site was used, one with relatively high organic content and one with low organic content. Adsorption kinetic tests for both TNT and a primary biotransformation byproduct 4-amino-2,6-dinitrotoluene (4A26DNT), alone and in combination, were performed and adsorption isotherms were developed. Results indicate a faster rate of adsorption for 4A26DNT than for TNT, as well as a larger extent of adsorption when the two compounds are both present. As expected, incubation time was shown to affect the extent of adsorption as well as the extractability and transformation of TNT. Large differences in kinetic patterns were obtained for each soil. Isotherm shape was similar for both soils, however extent of adsorption differed by several orders of magnitude.

  16. Surfactant-enhanced bioremediation of soil contaminated with 2,4,6-trinitrotoluene in soil slurry reactors

    SciTech Connect

    Boopathy, R.; Manning, J.

    1999-01-01

    The addition of food-grade surfactants could improve the use of native soil bacteria to biodegrade explosives-contaminated soil under co-metabolic conditions by enhancing the rates of explosives` desorption from soil, thus increasing the bioavailability of explosives for microbial degradation. The objective of this study is to decrease residence time in the reactor, thereby increasing output and reducing cleanup costs. In this study, Tween 80 (monooleate) served not only as a surfactant but also as the carbon substrate for soil microorganisms. Four 2-L soil slurry reactors were operated in batch mode with soil containing 2,4,6-trinitrotoluene (TNT). Results indicated that TNT was removed in all reactors except the control (no added carbon source). The reactor enriched with surfactant and molasses performed better than reactors with either molasses or surfactant alone. The TNT and its metabolite, 4-amino-2,6-dinitrotoluene, were removed faster in the reactor with surfactant plus molasses than in the reactor with molasses alone as carbon source. A radiolabeling study of the mass balance of TNT in the slurry reactors showed substantial mineralization of TNT to carbon dioxide.

  17. Large-Scale Synthesis of Crystalline 1,2,3,4,6,7-Hexa-O-acetyl-l-glycero-α-d-manno-heptopyranose

    PubMed Central

    Stanetty, Christian; Baxendale, Ian R

    2015-01-01

    The higher-carbon sugar l-glycero-d-manno-heptose is a major constituent of the inner core region of the lipopolysaccharide (LPS) of many Gram-negative bacteria. All preparative routes used to date require multiple steps, and scalability has been rarely addressed. Here a highly practical synthesis of crystalline 1,2,3,4,6,7-hexa-O-acetyl-l-glycero-α-d-manno-heptopyranose by a simple four-step sequence starting from l-lyxose is disclosed. Only two recrystallisations are required and the process was demonstrated on a >100 mmol scale, yielding 41 g of the target compound. PMID:26097405

  18. Biodegradation of TNT (2,4,6-Trinitrotoluene) by Phanerochaete chrysosporium

    SciTech Connect

    Fernando, T.; Bumpus, J.A.; Aust, S.D. )

    1990-06-01

    Extensive biodegradation of TNT (2,4,6-trinitrotoluene) by the white rot fungus Phanerochaete chrysosporium was observed. At an initial concentration of 1.3 mg/liter, 35.4 {plus minus} 3.6% of the ({sup 14}C)TNT was degraded to {sup 14}CO{sub 2} in 18 days. The addition of glucose 12 days after the addition of TNT did not stimulate mineralization, and, after 18 days of incubation with TNT only, about 3.3% of the initial TNT could be recovered. Mineralization of ({sup 14}C)TNT absorbed on soil was also examined. Ground corncobs served as the nutrient for slow but sustained degradation of ({sup 14}C)TNT to {sup 14}CO{sub 2} such that 6.3 {plus minus} 0.6% of the ({sup 14}C)TNT initially present was converted to {sup 14}CO{sub 2} during the 30-day incubation period. Mass balance analysis of liquid cultures and of soil-corncob cultures revealed that polar ({sup 14}C)TNT metabolites are formed in both systems, and high-performance liquid chromatography analyses revealed that less then 5% of the radioactivity remained as undegraded ({sup 14}C)TNT following incubation with the fungus in soil and liquid cultures. When the concentration of TNT in cultures (both liquid and soil) was adjusted to contamination levels that might be found in the environment, i.e., 10,000 mg/kg in soil and 100 mg/liter in water, mineralization studies showed that 18.4 {plus minus} 2.9% and 19.6 {plus minus} 3.5% of the initial TNT was converted to {sup 14}CO{sub 2} in 90 days in soil and liquid cultures, respectively. In both cases (90 days in water at 100 mg/liter and in soil at 10,000 mg/kg) approximately 85% of the TNT was degraded. These results suggest that this fungus may be useful for the decontamination of sites in the environment contaminated with TNT.

  19. Toxicity and bioaccumulation of 2,4,6-trinitrotoluene in fathead minnow (Pimephales promelas).

    PubMed

    Yoo, Leslie J; Lotufo, Guilherme R; Gibson, Alfreda B; Steevens, Jeffery A; Sims, Jerre G

    2006-12-01

    Few studies have determined the toxicity and bioaccumulation potential of explosive compounds in freshwater fish. In the present study, fathead minnow (Pimephales promelas) were exposed to a range of 2,4,6-trinitrotoluene (TNT) concentrations (0.44-44 micromol/L [0.1-10 mg/L] and 4.4-22.0 micromol/L [1.0-5.0 mg/L] in 4- and 10-d experiments, respectively). Median lethal concentrations of 11.93 micromol/L (2.7 mg/L; 95% confidence limit [CL], 10.29-13.83 micromol/L) and 9.68 micromol/L (2.20 mg/L; 95% CL, 9.17-10.22 micromol/L) were calculated in the 4- and 10-d experiments, respectively, and median lethal body residue of 101.0 micromol/kg (95% CL, 86.0-118.7 micromol/kg) was calculated in 4-d experiments. To study bioaccumulation, fish were exposed to 4.4 micromol/L (1 mg/L) of TNT for 12 h. Rapid bioaccumulation of TNT occurred within the first 10 min of exposure (ku = 30.4 L/kg/ h). Elimination of sigmaTNT (molar sum of TNT and degradation products 2- and 4-aminodinitrotoluenes) was fast, with an elimination rate (ke) of 2.24/h and a short half-life (0.31 h). The bioconcentration factors determined using 6-h mean tissue and water concentrations of sigmaTNT were 8.40 and 4.68 L/kg for the uptake experiment and the uptake portion of the elimination experiments, respectively. To determine the target organ for TNT in fish, juvenile fathead minnow were exposed to 2.2 micromol/L (0.5 mg/L) of [14C]TNT for 10 d. Radiolabeled compounds primarily bioaccumulated in the visceral tissues and spleen in comparison to gill, brain, muscle, and remainder tissue groups. The present study demonstrates the low bioaccumulation potential and rapid uptake of TNT in the fathead minnow.

  20. 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.

  1. 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.

  2. 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.

  3. Structural properties, vibrational spectra and surface-enhanced Raman scattering of 2,4,6-trichloro- and tribromoanilines: A comparative study

    NASA Astrophysics Data System (ADS)

    Haruna, Kabiru; Saleh, Tawfik A.; Al Thagfi, Jameel; Al-Saadi, Abdulaziz A.

    2016-10-01

    A comparative electronic and spectroscopic analysis of 2,4,6-trichloroaniline (TCA) and 2,4,6-tribromoaniline (TBA) was carried out by theoretical and experimental techniques. The NH2 inversion barrier in TCA and TBA molecules was predicted to be three times less than that in aniline and 2,4,6-trifluoroaniline. The size of the halogen substituents in the ortho positions is shown by density functional theory to play an important role in determining the electronic and structural properties of the amino group in the investigated haloaniline derivatives. A thorough interpretation of the infrared and Raman spectra has been performed on the basis of the observed and calculated infrared and Raman spectra as well as calculated potential energy distribution values. In addition, the SERS spectra for both trihaloanilines were successfully collected up to a concentration of 10-6 M using aged hydroxylamine-reduced silver colloid as an active substrate for TCA and TBA. SERS intensities of several peaks were found to linearly change with concentration allowing quantitative analyses of TCA and TBA. A relatively stronger interaction in the case of TBA-silver colloids is predicted compared to the TCA analogue.

  4. Thermal stability of the anionic sigma complexes of 2,4,6-trinitroanisole with the methylates of the alkaline-earth metals

    SciTech Connect

    Glaz, A.I.; Soldatova, T.A.; Golopolosova, T.V.; Gitis, S.S.

    1987-09-10

    The study of the stability of the 1,1-dimethoxy-2,4,6-trinitrocyclohexadienates of the alkali metals when they are heated in air showed that their temperature of decomposition and the heat effect of the process are dependent on the nature of the cation. Our study centered on the thermal decomposition of the products resulting from the addition of the methylates of calcium, strontium, and barium to 2,4,6-trinitroanisole. For a quantitative assessment of the process we used the combined methods of differential-thermal analysis and differential thermogravimetry. The anionic sigma-complexes of 2,4,6-trinitroanisole with the methylates of the alkaline-earth metals decompose on heating into the corresponding picrates; at the same time, when one passes from the calcium slat to the strontium and barium salts the decomposition temperature and the heat effect of the process show a drop which is linked to the structure both of the complexes and of the picrates forming therefrom.

  5. Evolution of the Vertebrate Pax4/6 Class of Genes with Focus on Its Novel Member, the Pax10 Gene

    PubMed Central

    Feiner, Nathalie; Meyer, Axel; Kuraku, Shigehiro

    2014-01-01

    The members of the paired box (Pax) family regulate key developmental pathways in many metazoans as tissue-specific transcription factors. Vertebrate genomes typically possess nine Pax genes (Pax1–9), which are derived from four proto-Pax genes in the vertebrate ancestor that were later expanded through the so-called two-round (2R) whole-genome duplication. A recent study proposed that pax6a genes of a subset of teleost fishes (namely, acanthopterygians) are remnants of a paralog generated in the 2R genome duplication, to be renamed pax6.3, and reported one more group of vertebrate Pax genes (Pax6.2), most closely related to the Pax4/6 class. We propose to designate this new member Pax10 instead and reconstruct the evolutionary history of the Pax4/6/10 class with solid phylogenetic evidence. Our synteny analysis showed that Pax4, -6, and -10 originated in the 2R genome duplications early in vertebrate evolution. The phylogenetic analyses of relationships between teleost pax6a and other Pax4, -6, and -10 genes, however, do not support the proposed hypothesis of an ancient origin of the acanthopterygian pax6a genes in the 2R genome duplication. Instead, we confirmed the traditional scenario that the acanthopterygian pax6a is derived from the more recent teleost-specific genome duplication. Notably, Pax6 is present in all vertebrates surveyed to date, whereas Pax4 and -10 were lost multiple times in independent vertebrate lineages, likely because of their restricted expression patterns: Among Pax6-positive domains, Pax10 has retained expression in the adult retina alone, which we documented through in situ hybridization and quantitative reverse transcription polymerase chain reaction experiments on zebrafish, Xenopus, and anole lizard. PMID:24951566

  6. Evolution of the vertebrate Pax4/6 class of genes with focus on its novel member, the Pax10 gene.

    PubMed

    Feiner, Nathalie; Meyer, Axel; Kuraku, Shigehiro

    2014-07-01

    The members of the paired box (Pax) family regulate key developmental pathways in many metazoans as tissue-specific transcription factors. Vertebrate genomes typically possess nine Pax genes (Pax1-9), which are derived from four proto-Pax genes in the vertebrate ancestor that were later expanded through the so-called two-round (2R) whole-genome duplication. A recent study proposed that pax6a genes of a subset of teleost fishes (namely, acanthopterygians) are remnants of a paralog generated in the 2R genome duplication, to be renamed pax6.3, and reported one more group of vertebrate Pax genes (Pax6.2), most closely related to the Pax4/6 class. We propose to designate this new member Pax10 instead and reconstruct the evolutionary history of the Pax4/6/10 class with solid phylogenetic evidence. Our synteny analysis showed that Pax4, -6, and -10 originated in the 2R genome duplications early in vertebrate evolution. The phylogenetic analyses of relationships between teleost pax6a and other Pax4, -6, and -10 genes, however, do not support the proposed hypothesis of an ancient origin of the acanthopterygian pax6a genes in the 2R genome duplication. Instead, we confirmed the traditional scenario that the acanthopterygian pax6a is derived from the more recent teleost-specific genome duplication. Notably, Pax6 is present in all vertebrates surveyed to date, whereas Pax4 and -10 were lost multiple times in independent vertebrate lineages, likely because of their restricted expression patterns: Among Pax6-positive domains, Pax10 has retained expression in the adult retina alone, which we documented through in situ hybridization and quantitative reverse transcription polymerase chain reaction experiments on zebrafish, Xenopus, and anole lizard. PMID:24951566

  7. 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.

  8. Proteoglycans contain a 4.6 A repeat in muscular dystrophy corneas: x-ray diffraction evidence.

    PubMed Central

    Quantock, A J; Klintworth, G K; Schanzlin, D J; Capel, M S; Lenz, M E; Thonar, E J

    1996-01-01

    Synchrotron x-ray diffraction patterns from macular corneal dystrophy (MCD) corneas contain an unusual reflection that arises because of an undefined ultrastructure with a periodic repeat in the region of 4.6 A. In this study, we compared with wide-angle x-ray diffraction patterns obtained from four normal human corneas and four MCD corneas. Moreover, portions of two of the MCD corneas were pretreated with a specific glycosidase to shed light on the origin of the 4.6 A reflection. None of the normal corneas produced an x-ray reflection in the region of 4.6 A, whereas all four of the MCD corneas did (MCD type I at 4.65 A and 4.63 A, MCD type II at 4.63 A and 4.67 A). This reflection was diminished after incubation of the MCD tissues with either chondroitinase ABC or N-glycanase. The findings indicate that glycosaminoglycans or proteoglycans contribute to the unusual MCD x-ray reflection and hence most likely contain a periodic 4.6 A ultrastructure. Furthermore, the results imply that periodic 4.6 A MCD ultrastructures reside in either intact, unsulfated lumican molecules and regions of the CS/DS-containing molecules or in a region of a hybrid macromolecular aggregate formed by the interaction of the two molecules. PMID:8785355

  9. Metabolic study of androsta-1,4,6-triene-3,17-dione in horses using liquid chromatography/high resolution mass spectrometry.

    PubMed

    Kwok, Wai Him; Leung, Gary N W; Wan, Terence S M; Curl, Peter; Schiff, Peter J

    2015-08-01

    Androsta-1,4,6-triene-3,17-dione (ATD) is an irreversible steroidal aromatase inhibitor and is marketed as a supplement. It has been reported to effectively reduce estrogen biosynthesis and significantly increase the levels of endogenous steroids such as dihydrotestosterone and testosterone in human. ATD abuses have been reported in human sports. Its metabolism in human has been studied, and the in vitro metabolic study of ATD in horses has been reported, however, little is known about its biotransformation and elimination in horses. This paper describes the in vitro and in vivo metabolism studies of ATD in horses, with an objective of identifying the target metabolites with the longest detection time for controlling ATD abuse. In vitro metabolism studies of ATD were performed using homogenized horse liver. ATD was found to be extensively metabolized, and its metabolites could not be easily characterized by gas chromatography/mass spectrometry (GC/MS) due to insufficient sensitivity. Liquid chromatography/high resolution mass spectrometry (LC/HRMS) was therefore employed for the identification of in vitro metabolites. The major biotransformations observed were combinations of reduction of the olefin groups and/or the keto group at either C3 or C17 position. In addition, mono-hydroxylation in the D-ring was observed along with reduction of the olefin groups and/or the keto group at C17 position. Fourteen in vitro metabolites, including two epimers of androsta-1,4,6-trien-17-ol-3-one (M1a, M1b), androsta-4,6-diene-3,17-dione (M2), boldione (M3), androsta-4,6-diene-17β-ol-3-one (M4), androsta-4,6-diene-3-ol-17-one (M5), boldenone and epi-boldenone (M6a, M6b), four stereoisomers of hydroxylated androsta-1,4,6-trien-17-ol-3-one (M7a to M7d), and two epimers of androsta-1,4-diene-16α,17-diol (M8a, M8b), were identified. The identities of all metabolites, except M1a, M5, M7a to M7d, were confirmed by matching with authentic reference standards using LC/HRMS. For the in

  10. MEISENHEIMER COMPLEX BETWEEN 2,4,6-TRINITROTOLUENE AND 3-AMINOPROPYLTRIETHOXYSILANE AND ITS USE FOR A PAPER-BASED SENSOR

    PubMed Central

    Hughes, Shantelle; Dasary, Samuel S. R.; Begum, Salma; Williams, Nya; Yu, Hongtao

    2015-01-01

    2,4,6-Trinitrotoluene (TNT) forms a red-colored Meisenheimer complex with 3-aminopropyltrenthoxysilane (APTES) both in solution and on solid phase. The TNT-APTES complex is unique since it forms yellow-colored complexes with 2,4,6-trinitrophenol and 4-nitrophenol, and no complex with 2,4-dinitrotoluene. The absorption spectrum of TNT-APTES has two absorption bands at 530 and 650 nm, while APTES complexes with 2,4,6-trinitrophenol and 4-nitrophenol have absorption maxima at around 420 nm, and no absorption change for 2,4-dinitrotoluene. The TNT-APTES complex facilitates the exchange of the TNT-CH3 proton/deuteron with solvent molecules. The red color of TNT-APTES is immediately visible at 1 µM of TNT. PMID:26380171

  11. 2,2-Dimethyl-5-[(2-nitro-anilino)methyl-idene]-1,3-dioxane-4,6-dione.

    PubMed

    He, Yu-Xin; Wu, Jin-Wei; Tong, Rong-Sheng; Shi, Jian-You

    2011-05-01

    The crystal of the title compound, C(13)H(12)N(2)O(6), contains a bifurcated intra-molecular hydrogen bond between the N-H group and one of the O atoms from both the nitro group and the dioxane-4,6-dione moiety. In addition, mol-ecules are linked by a series of inter-molecular C-H⋯O secondary inter-actions. The dihedral angles between the benzene ring and the nitro group and the conjugated part of the dioxane-4,6-dione moiety are 19.1 (2) and 17.89 (7)°, respectively. PMID:21754514

  12. Efficient desymmetrization of 4,6-di-O-benzyl-myo-inositol by Lipozyme TL-IM.

    PubMed

    Vasconcelos, Marcela G; Briggs, Raissa H C; Aguiar, Lucia C S; Freire, Denise M G; Simas, Alessandro B C

    2014-03-11

    The enantioselective enzymatic desymmetrization of 4,6-di-O-benzyl-myo-inositol, a myo-inositol derivative, was effectively catalyzed by Thermomyces lanuginosus lipase (TL-IM). The product 1D-1-O-acetyl-4,6-di-O-benzyl-myo-inositol, a useful precursor to inositol phosphates, was obtained in excellent yield and enantiomeric excess. Through the investigation of the effects of solvent, biocatalyst load, and temperature, a more economical procedure resulted. The feasibility of biocatalyst reuse was also shown.

  13. Federal Emergency Management Information System (FEMIS) Bill of Materials (BOM) for FEMIS Version 1.4.6

    SciTech Connect

    Homer, B.J., Johnson, D.M.; Wood, B.M.; Stoops, L.R.; Fangman, P.M.; Johnson, R.L.; Loveall, R.M.; Millard, W.D.; Johnson, S.M.; Downing, T.R.

    1999-03-12

    This document describes the hardware and software required for the Federal Emergency Management Information System version 1.4.6 (FEMIS{copyright} v1.4.6). FEMIS is designed for a single Chemical Stockpile Emergency Preparedness Program (CSEPP) site that has multiple Emergency Operations Centers (EOCs). Each EOC has personal computers (PCs) that emergency planners and operations personnel use to do their jobs. These PCs are connected via a local area network (LAN) to servers that provide EOC-wide services. Each EOC is interconnected to other EOCS via a Wide Area Network (WAN).

  14. Bibliographie annotee 4-6--Francais langue seconde-immersion: Selection d'ouvrages de la litterature jeunesse. Supplement 2001 (Annotated Bibliography 4-6--French as a Second Language-Immersion: Selection of Works from Children's Literature. Supplement 2001).

    ERIC Educational Resources Information Center

    Alberta Learning, Edmonton. Direction de l'education francaise.

    The document comprises 42 inserts to be included in the List of Books (4-6) for French as a Second Language (Immersion)--a selection of works of youth literature--published by Alberta Learning in 2000. Thirty-seven of the items appeal to the world of imagination and esthetics, and five items are of an informative nature. An appendix, entitled "How…

  15. 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

  16. 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

  17. Primary role of cytochrome P450 2B6 in the oxidative metabolism of 2,2',4,4',6-pentabromodiphenyl ether (BDE-100) to hydroxylated BDEs.

    PubMed

    Gross, Michael S; Butryn, Deena M; McGarrigle, Barbara P; Aga, Diana S; Olson, James R

    2015-04-20

    Human exposure to polybrominated diphenyl ethers (PBDEs) through various routes poses deleterious health effects. PBDEs are biotransformed into hydroxylated metabolites (OH-BDEs) via cytochrome P450s (P450s), which may add to their neurotoxic effects. This study characterizes the in vitro metabolism of 2,2',4,4',6-pentabromodiphenyl ether (BDE-100), one of the most abundant PBDE congeners found in humans, by recombinant human P450s and pooled human liver microsomes (HLMs). Ten recombinant P450s were individually incubated with BDE-100 to monitor P450-specific metabolism. P450 2B6 was found to be the predominant enzyme responsible for nearly all formation of six mono-OH-pentaBDE and two di-OH-pentaBDE metabolites. Four metabolites were identified as 3-hydroxy-2,2',4,4',6-pentabromodiphenyl ether (3-OH-BDE-100), 5'-hydroxy-2,2',4,4',6-pentabromodiphenyl ether (5'-OH-BDE-100), 6'-hydroxy-2,2',4,4',6-pentabromodiphenyl ether (6'-OH-BDE-100), and 4'-hydroxy-2,2',4,5',6-pentabromodiphenyl ether (4'-OH-BDE-103) through use of reference standards. The two remaining mono-OH-pentaBDE metabolites were hypothesized using mass spectral fragmentation characteristics of derivatized OH-BDEs, which allowed prediction of an ortho-OH-pentaBDE and a para-OH-pentaBDE positional isomer. Additional information based on theoretical boiling point calculations using COnductor-like Screening MOdel for Realistic Solvents (COSMO-RS) and experimental chromatographic retention times were used to identify the hypothesized metabolites as 2'-hydroxy-2,3',4,4',6-pentabromodiphenyl ether (2'-OH-BDE-119) and 4-hydroxy-2,2',4',5,6-pentabromodiphenyl ether (4-OH-BDE-91), respectively. Kinetic studies of BDE-100 metabolism using P450 2B6 and HLMs revealed Km values ranging from 4.9 to 7.0 μM and 6-10 μM, respectively, suggesting a high affinity toward the formation of OH-BDEs. Compared to the metabolism of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) and 2,2',4,4',5-pentabromodiphenyl ether (BDE-99

  18. The Greatest Educational Change America Has Ever Seen, 2003: Lesson Plans for Grades 4-6.

    ERIC Educational Resources Information Center

    United States Mint (Dept. of Treasury), Washington, DC.

    The United States Mint 50 State Quarters Program launched a 10-year initiative in 1999, commemorating each of the nation's states in the order they were admitted into the Union. Approximately every 10 weeks (5 times a year) through 2008, a new limited-edition quarter that displays an individual state's design is released into general circulation.…

  19. Gendered Patterns in High Achievement in Mathematics for Grades 4, 6, and 8

    ERIC Educational Resources Information Center

    Falvey, Laura J.

    2012-01-01

    The issue of underrepresentation of women in science, technology, engineering, and mathematics (STEM) careers is especially important to the future of the United States in current times when STEM careers play an increasingly important role in the global economy (Toulmin & Groome, 2007; United States Department of Labor, 2007). The pool of…

  20. Biotransformation of the explosives 2,4,6-trinitrotoluene and 1,3,5-triaza 1,3,5-trinitrocyclohexane by Clostridium bifermentans

    SciTech Connect

    Regan, K.M.; Crawford, R.L.

    1994-12-31

    A strain of Clostridium bifermentans isolated from a munitions-supplemented enrichment was able to remove both TNT (2,4,6-trinitrotoluene) and RDX (1,3,5-triaza 1,3,5-trinitrocyclohexane) from its growth media. Biotransformations of TNT and RDX by cometabolism in a nutrient rich medium reduced the removal time from several days to a few hours, as compared to a nutrient limited medium. Redox potential (Eh) of the media had important effects on the biological and abiological transformations of the munition compounds.

  1. Factors affecting microbial 2,4,6-trinitrotoluene mineralization in contaminated soil

    USGS Publications Warehouse

    Bradley, P.M.; Chapelle, F.H.

    1995-01-01

    The influence of selected environmental factors on microbial TNT mineralization in soils collected from a TNT-contaminated site at Weldon Spring, MO, was examined using uniformly ring-labeled [14C]TNT. Microbial TNT mineralization was significantly inhibited by the addition of cellobiose and syringate. This response suggests that the indigenous microorganisms are capable of metabolizing TNT but preferentially utilize less recalcitrant substrates when available. The observed inhibition of TNT mineralization by TNT concentrations higher than 100 ??mol/kg of soil and by dry soil conditions suggests that toxic inhibition of microbial activity at high TNT concentrations and the periodic drying of these soils have contributed to the long-term persistence of TNT at Weldon Spring. In comparison to aerobic microcosms, mineralization was inhibited in anaerobic microcosms and in microcosms with a headspace of air amended with oxygen, suggesting that a mosaic of aerobic and anaerobic conditions may optimize TNT degradation at this site.

  2. [2, 4, 6-Trichlorophenol Mineralization Promoted by Anaerobic Reductive Dechlorination of Acclimated Sludge and Extracellular Respiration Dechlorination Pathway].

    PubMed

    Song, Jia-xiu; Li, Ling; Sheng, Fan-fan; Guo, Cui-xiang; Zhang, Yong-ming; Li, Zu-yuan; Wang, Tian-li

    2015-10-01

    In anaerobic conditions, the acclimation of activated sludge was studied with sodium lactate as the electron donor and 2,4,6-trichlorophenol as the electron acceptor. Metabolic characteristics of dechlorination were the focus of this study. The result showed highly efficient dechlorination on 2, 4, 6-trichlorophenol that the conversion rate reached to 100% in 9 - 24 h when initial concentrations of sodium lactate and 2,4, 6-trichlorophenol were 20 mmol x L(-1) and 40 - 80 μmol x L(-1), respectively. The intermediate product 2,4-dichlorophenol was found in low concentration (< 4.22 μmol x L(-1)). And 4-chlorophenol and phenol were the main products. Ortho chlorophenol (2, 4, 6-trichlorophenol, 2, 4-dichlorophenol) can be converted rapidly by acclimated sludge, while the further conversion of 4-chlorophenol and phenol was limited. The residues of anaerobic metabolism were degraded by aerobic sludge, among which 4-chlorophenol (initial concentration of 33 mol x L(-1)) removal rate was up to 100% under aerobic conditions. The acclimated bacteria can rapidly transfer Fe(III) and humus (AQDS) into reductive Fe(II) and AQH2DS which indicated that the dissimilatory iron reducing bacteria was enriched in the acclimated sludge. The electron mediator [Fe(III) and AQDS] significantly accelerated the dechlorination rate. The acclimated sludge could perform extracellular respiration dechlorination with electron mediators.

  3. Structural, Magnetic, and Optical Properties of A3V4(PO4)6 (A = Mg, Mn, Fe, Co, Ni).

    PubMed

    Porter, Spencer H; Xiong, Jie; Avdeev, Maxim; Merz, David; Woodward, Patrick M; Huang, Zhenguo

    2016-06-20

    Combined synchrotron and neutron powder diffraction indicates that A3V4(PO4)6 (A = Mg, Mn, Fe, Co, Ni) compounds crystallize with triclinic P1̅ symmetry. Lattice parameters expand as expected with successive increases in the ionic radius of the A(2+) ion. Cation disorder on the octahedral sites increases as the ionic radii of A(2+) ion decreases. Direct-current magnetic susceptibility measurements indicate that all compounds with magnetic A(2+) ions order anti-ferromagnetically with transition temperatures ranging from 12 to 15 K. Effective magnetic moments for A3V4(PO4)6 (A = Mg, Mn, Fe, Co, Ni) are 5.16, 11.04, 10.08, 9.76, and 7.96 μB per formula unit, respectively, in line with calculated values for high-spin transition metal ions. With the exception of Co3V4(PO4)6 the ultraviolet-visible spectra are dominated by d-d transitions of the V(3+) ions. The striking emerald green color of Co3V4(PO4)6 arises from the combined effects of d-d transitions involving both V(3+) and Co(2+). PMID:27227553

  4. Our Changing Land: Stone Mountain State Park. An Environmental Education Learning Experience Designed for Grades 4-6.

    ERIC Educational Resources Information Center

    Trivette, Larry

    Stone Mountain State Park's environmental education learning experience, Our Changing Land, introduces the student to the geology of the Blue Ridge Mountains, with emphasis on Stone Mountain, through a series of hands-on activities. The learning experience is designed for grades 4-6 and meets curriculum objectives of the standard course of study…

  5. 5-(4-Fluoro-benzyl-idene)-2,2-dimethyl-1,3-dioxane-4,6-dione.

    PubMed

    Zeng, Wu-Lan

    2010-01-01

    The title compound, C(13)H(11)FO(4), was prepared by the reaction of 2,2-dimethyl-1,3-dioxane-4,6-dione and 4-fluoro-benz-alde-hyde in ethanol. The 1,3-dioxane ring adopts an envelope conformation. The crystal structure is stabilized by weak inter-molecular C-H⋯O hydrogen bonds. PMID:21588707

  6. 2,2-Dimethyl-5-[(pyridin-2-yl-amino)-methyl-idene]-1,3-dioxane-4,6-dione.

    PubMed

    Shi, Jian-You; Li, Jin-Qi; Tong, Rong-Sheng; Lin, He; Lu, Chen

    2011-01-01

    In the title compound, C(12)H(12)N(2)O(4), the dihedral angle between the pyridine and enamine planes is 3.5 (3)°, while the angle between the dioxanedione (seven atoms) and enamine planes is 4.6 (3)°. The dioxane ring approximates an envelope conformation. PMID:21522947

  7. The relation between oral hygiene skills and the prevalence of dental caries among 4 - 6-year-old children.

    PubMed

    Razmienė, Jaunė; Vanagas, Giedrius; Bendoraitienė, Eglė; Vyšniauskaitė, Aurelija

    2011-01-01

    AIM OF THE STUDY. To evaluate the tooth brushing skills and the prevalence of dental caries as well as its intensity in relation to oral hygiene skills among 4 - 6-year-old children. MATERIAL AND METHODS. The cross-sectional study was performed from November 16, 2009 to January 12, 2010. 235 children (4 - 6-year old) were randomly selected from kindergartens in Plungė and Jonava in Lithuania. The results of study were registered in the special forms prepared in accordance with the recommendations of WHO. Parents of the children were asked to fill in the questionnaires. RESULTS. The results of the study show that 91% (Plungė) and 90% (Jonava) of 4 - 6-year-old children have caries in their primary teeth. The prevalence of caries is different in relation to age: 78.7% of 4-year-old children, 97.3% of 5-year-old children, and 95.3% of 6-year-old children. The intensity of caries is as follows: 4.9 (SN=±4.9), 7.5 (SN=±4.5), and 8.2 (SN=±4.7). CONCLUSIONS. There is the high prevalence of caries, particularly of not treated forms, among 4 - 6-year-old children. The oral hygiene index is just satisfactory.

  8. Tracks the Sand. Jockey's Ridge State Park: An Environmental Education Learning Experience Designed for Grades 4-6.

    ERIC Educational Resources Information Center

    Crutchfield, Fran

    This learning packet, one in a group of eight, was developed by the Jockey's Ridge State Park in North Carolina for Grades 4-6 to learn about animal adaptation and behavior in the dune environment. Loose-leaf pages are presented in 10 sections that contain: (1) introductions to the North Carolina State Park System, the Jockey Ridge State Park, the…

  9. Do Children See the "Danger" in "Dangerous"? Grade 4, 6, and 8 Children's Reading of Morphologically Complex Words

    ERIC Educational Resources Information Center

    Deacon, S. Helene; Whalen, Rachel; Kirby, John R.

    2011-01-01

    We examined whether Grade 4, 6, and 8 children access the base form when reading morphologically complex words. We asked children to read words varying systematically in the frequency of the surface and base forms and in the transparency of the base form. At all grade levels, children were faster at reading derived words with high rather than low…

  10. Strand I - Physical Health; Dental Health for Grades 4-6. Special Edition for Evaluation and Discussion.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Curriculum Development Center.

    This is a curriculum guide for teaching dental health for grades 4-6. Each topic area is outlined under the headings of: (1) reference; (2) major understandings and fundamental concepts; (3) suggested teaching aids and learning activities; and (4) supplementary information for teachers. Main topics include: (1) growth and development of teeth; (2)…

  11. Design and Validation of a Photographic Expressive Persian Grammar Test for Children Aged 4-6 Years

    ERIC Educational Resources Information Center

    Haresabadi, Fatemeh; Ebadi, Abbas; Shirazi, Tahereh Sima; Dastjerdi Kazemi, Mehdi

    2016-01-01

    Syntax has a high importance among linguistic parameters, and syntax-related problems are the most common in language disorders. Therefore, the present study aimed to design a Photographic Expressive Persian Grammar Test for Iranian children in the age group of 4-6 years and to determine its validity and reliability. First, the target…

  12. 40 CFR 721.8965 - 1H-Pyrole-2, 5-dione, 1-(2,4,6-tribromophenyl)-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.8965 1H-Pyrole-2, 5-dione, 1-(2,4,6-tribromophenyl)-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as...

  13. Small Schools Mathematics Curriculum, 4-6: Reading, Language Arts, Mathematics, Science, Social Studies. Scope, Objectives, Activities, Resources, Monitoring Procedures.

    ERIC Educational Resources Information Center

    Hartl, David, Ed.; And Others

    The Washington grade 4-6 mathematics curriculum is organized according to the Small Schools Materials format which lists the sequence of learning objectives related to a specific curriculum area, recommends a teaching and mastery grade placement, and identifies activities, monitoring procedures and possible resources used in teaching to the…

  14. The Effects of Psychomotor Skills Instruction on Attitude toward Singing and General Music among Students in Grades 4-6.

    ERIC Educational Resources Information Center

    Phillips, Kenneth H.; Aitchison, Randall E.

    1998-01-01

    Investigates the relationship of psychomotor skills instruction on student attitudes in grades 4-6 towards singing and general music instruction. Finds females have more positive attitudes, interest declines as grade-level increases, group vocal instruction may produce more positive attitudes, and a positive relationship between liking to sing in…

  15. Grade 4-6 Student Conceptions and Utilization of Informal and Formal Variable Representations across Mathematically Equivalent Tasks

    ERIC Educational Resources Information Center

    Switzer, Matt

    2011-01-01

    This study reports how 24 grade 4-6 students in one elementary and middle school interpreted formal and informal representations of variables. While interpretations for variables represented as letters (e.g., x and y) have been well established for students in algebra classes and beyond, little research into elementary school students'…

  16. Leave It to Beaver. Merchants Millpond State Park: An Environmental Education Learning Experience Designed for Grades 4-6.

    ERIC Educational Resources Information Center

    Williams, Floyd K.

    This learning packet, one in a group of eight, was developed by the Merchants Millpond State Park in North Carolina to teach students in grades 4-6 about the habitat and lifestyle of the beaver. Loose-leaf pages are presented in nine sections that contain: (1) introductions to the North Carolina State Parks System, the Merchants Millpond State…

  17. Absorption, tissue distribution, and elimination of residues after 2,4,6-trinitro[14C]toluene administration to sheep

    Technology Transfer Automated Retrieval System (TEKTRAN)

    2,4,6-Trinitrotoluene (TNT) is a persistent contaminant present in high concentrations of some industrial and military sites. Traditional biological bioremediation techniques typically rely on the immobilization of TNT reduction products rather than on TNT mineralization. We hypothesized that sheep ...

  18. Distribution and residues of orally administered 2,4,6-trinitro[14C]toluene in ruminating sheep.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    2,4,6-Trinitrotoluene (TNT) is a persistent contaminant of some military and industrial soils. The purpose of this study was to determine the fate of 14C-TNT in ruminating sheep. Animals were dosed with 35.5 mg each of dietary unlabelled TNT for 21 consecutive d. On d 22 sheep were orally dosed with...

  19. Draft Genome Sequence of Pseudomonas putida JLR11, a Facultative Anaerobic 2,4,6-Trinitrotoluene Biotransforming Bacterium.

    PubMed

    Pascual, Javier; Udaondo, Zulema; Molina, Lazaro; Segura, Ana; Esteve-Núñez, Abraham; Caballero, Antonio; Duque, Estrella; Ramos, Juan Luis; van Dillewijn, Pieter

    2015-09-03

    We report the draft genome sequence of Pseudomonas putida JLR11, a facultative anaerobic bacterium that has been studied in detail for its capacity to use the explosive 2,4,6-trinitrotoluene (TNT) as a nitrogen source. The sequence confirms the mechanisms used by this versatile strain to reduce and assimilate nitrogen from TNT.

  20. Draft Genome Sequence of Pseudomonas putida JLR11, a Facultative Anaerobic 2,4,6-Trinitrotoluene Biotransforming Bacterium

    PubMed Central

    Pascual, Javier; Udaondo, Zulema; Molina, Lazaro; Segura, Ana; Esteve-Núñez, Abraham; Caballero, Antonio; Duque, Estrella; Ramos, Juan Luis

    2015-01-01

    We report the draft genome sequence of Pseudomonas putida JLR11, a facultative anaerobic bacterium that has been studied in detail for its capacity to use the explosive 2,4,6-trinitrotoluene (TNT) as a nitrogen source. The sequence confirms the mechanisms used by this versatile strain to reduce and assimilate nitrogen from TNT. PMID:26337875

  1. Identification of a hydride-Meisenheimer complex as a metabolite of 2,4,6-trinitrotoluene by a Mycobacterium strain.

    PubMed

    Vorbeck, C; Lenke, H; Fischer, P; Knackmuss, H J

    1994-02-01

    A bacterial strain, Mycobacterium sp. strain HL 4-NT-1, enriched with 4-nitrotoluene as its sole source of nitrogen, was able to metabolize 2,4,6-trinitrotoluene under aerobic conditions. The dark red-brown metabolite, which accumulated in the culture fluid, was identified as a hydride-Meisenheimer complex by comparison with an authentic synthetic sample.

  2. [2, 4, 6-Trichlorophenol Mineralization Promoted by Anaerobic Reductive Dechlorination of Acclimated Sludge and Extracellular Respiration Dechlorination Pathway].

    PubMed

    Song, Jia-xiu; Li, Ling; Sheng, Fan-fan; Guo, Cui-xiang; Zhang, Yong-ming; Li, Zu-yuan; Wang, Tian-li

    2015-10-01

    In anaerobic conditions, the acclimation of activated sludge was studied with sodium lactate as the electron donor and 2,4,6-trichlorophenol as the electron acceptor. Metabolic characteristics of dechlorination were the focus of this study. The result showed highly efficient dechlorination on 2, 4, 6-trichlorophenol that the conversion rate reached to 100% in 9 - 24 h when initial concentrations of sodium lactate and 2,4, 6-trichlorophenol were 20 mmol x L(-1) and 40 - 80 μmol x L(-1), respectively. The intermediate product 2,4-dichlorophenol was found in low concentration (< 4.22 μmol x L(-1)). And 4-chlorophenol and phenol were the main products. Ortho chlorophenol (2, 4, 6-trichlorophenol, 2, 4-dichlorophenol) can be converted rapidly by acclimated sludge, while the further conversion of 4-chlorophenol and phenol was limited. The residues of anaerobic metabolism were degraded by aerobic sludge, among which 4-chlorophenol (initial concentration of 33 mol x L(-1)) removal rate was up to 100% under aerobic conditions. The acclimated bacteria can rapidly transfer Fe(III) and humus (AQDS) into reductive Fe(II) and AQH2DS which indicated that the dissimilatory iron reducing bacteria was enriched in the acclimated sludge. The electron mediator [Fe(III) and AQDS] significantly accelerated the dechlorination rate. The acclimated sludge could perform extracellular respiration dechlorination with electron mediators. PMID:26841610

  3. Testing the Waters. Duke Power State Park: An Environmental Education Learning Experience Designed for Grades 4-6.

    ERIC Educational Resources Information Center

    Rhinehart, William C.; Beazley, Lea J.

    This learning packet, one in a group of eight, was developed by the Duke Power State Park in North Carolina for Grades 4-6 to learn to identify macroinvertebrates found in Lake Norman. Loose-leaf pages are presented in nine sections that contain: (1) introductions to the North Carolina State Park System, the Duke Power State Park, the park's…

  4. Does the Animal Fun program improve motor performance in children aged 4-6 years?

    PubMed

    Piek, J P; McLaren, S; Kane, R; Jensen, L; Dender, A; Roberts, C; Rooney, R; Packer, T; Straker, L

    2013-10-01

    The Animal Fun program was designed to enhance the motor ability of young children by imitating the movements of animals in a fun, inclusive setting. The efficacy of this program was investigated through a randomized controlled trial using a multivariate nested cohort design. Pre-intervention scores were recorded for 511 children aged 4.83 years to 6.17 years (M=5.42 years, SD=3.58 months). Six control and six intervention schools were compared 6 months later following the intervention, and then again at 18 months after the initial testing when the children were in their first school year. Changes in motor performance were examined using the Bruininks-Oseretsky Test of Motor Proficiency short form. Data were analyzed using multi-level-mixed effects linear regression. A significant Condition×Time interaction was found, F(2,1219)=3.35, p=.035, demonstrating that only the intervention group showed an improvement in motor ability. A significant Sex×Time interaction was also found, F(2,1219)=3.84, p=.022, with boys improving over time, but not girls. These findings have important implications for the efficacy of early intervention of motor skills and understanding the differences in motor performance between boys and girls. PMID:23186610

  5. Effect of several analogs of 2,4,6-triphenyldioxane-1,3 on constitutive androstane receptor activation.

    PubMed

    Pustylnyak, Vladimir; Yarushkin, Andrei; Kachaylo, Ekaterina; Slynko, Nikolai; Lyakhovich, Vyacheslav; Gulyaeva, Lyudmila

    2011-07-15

    2,4,6-Triphenyldioxane-1,3 (TPD) is a highly effective species-specific inducer of CYP2В in rats. Several analogs of TPD were synthesized to verify a hypothesis that minor changes in the inducer structure can cause changes in induction abilities (R=H, cisTPD and transTPD; R=N(CH(3))(2), transpDMA; R=NO(2), transpNO(2); R=F, transpF; R=OCH(3), transpMeO). Five of six compounds were able to activate CAR in rat liver. Results of Western-blot and ChIP showed that cisTPD and transTPD, transpDMA, transpNO(2), transpF treatment stimulated nuclear accumulation of CAR and evoked CAR receptor PBREM-binding activity in rat liver. cisTPD, transTPD, transpDMA, transpNO(2) and transpF administration significantly increased total CYP content (1.3-2.5 fold) and the level of PROD (12-20 fold), CYP2B specific activity, whereas transpMeO did not have any effects. Western blot and real-time RT-PCR showed that the increase of PROD in liver is related to the high content of CYP2B proteins and paralleled the increase of CYP2B1 (10-43 fold) and CYP2B2 (8-26 fold) mRNAs. At the same time content of CYP2B proteins and CYP2B1 and CYP2B2 mRNA levels were unchanged in rat liver after transpMeO treatment. The dose-response studies have shown that cisTPD, transpDMA, transpF and transpNO(2) have similar potency, and transTPD is less potent derivative. Moreover, it is likely transTPD act as a partial CAR activator. Thus, our results provide evidence to support the conclusion that the differences of TPD analogs ability to activate CYP2B gene expression can be explained by various interactions with CAR. PMID:21453690

  6. Biochronometry; Proceedings of the Symposium, Friday Harbor, Wash., September 4-6, 1969.

    NASA Technical Reports Server (NTRS)

    Menaker, M.

    1971-01-01

    Topics discussed include circadian activity rhythms in birds and man, variation of circadian rhythms in monkeys, resetting of circadian eclosion rhythm in fruitflies, the effectiveness of mathematical models of circadian rhythms, the influence of ac electric fields on circadian rhythms in man, the relation between changes in the metabolic rate and circadian periodicity of the resistance of pocket mice to ionizing radiation, the relation between circadian organization and the photoperiodic time measurement in moths, the circadian rhythm of optic nerve potentials in the isolated eye of the sea hare, phasing of circadian temperature rhythms in the pocket mouse by specific spectral regions, the phase-shifting effect of light on circadian rhymicity in the fruifly, hormonal control of circadian rhythms in the fruitfly, metabolically controlled temperature compensation in the circadian rhythm of algae, and circadian rhythms in the chloroplasts of algae. Individual items are abstracted in this issue.

  7. Adsorption of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) on a soil organic matter. A DFT M05 computational study.

    PubMed

    Sviatenko, Liudmyla K; Gorb, Leonid; Shukla, Manoj K; Seiter, Jennifer M; Leszczynska, Danuta; Leszczynski, Jerzy

    2016-04-01

    Adsorption of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) by soil organic matter considering the Leonardite Humic Acid (LHA) model at the M05/tzvp level of Density Functional Theory (DFT) applying cluster approximation has been investigated. Different orientations of CL-20 toward LHA surface were examined. It was found that deprotonation of LHA is required to obtain stable complexes with CL-20. Hydrogen bonds between CL-20 and deprotonated LHA were analyzed applying the atoms in molecules (AIM) theory. An attachment or removal of an electron with respect to the complex does not have significant effect on mutual orientation of the adsorbent in complexes. It was shown that adsorbed CL-20 does not undergo redox transformation and, therefore, adsorption on soil organic matter may be responsible for decrease of the degradation rate of CL-20 in soil.

  8. Adsorption of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) on a soil organic matter. A DFT M05 computational study.

    PubMed

    Sviatenko, Liudmyla K; Gorb, Leonid; Shukla, Manoj K; Seiter, Jennifer M; Leszczynska, Danuta; Leszczynski, Jerzy

    2016-04-01

    Adsorption of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) by soil organic matter considering the Leonardite Humic Acid (LHA) model at the M05/tzvp level of Density Functional Theory (DFT) applying cluster approximation has been investigated. Different orientations of CL-20 toward LHA surface were examined. It was found that deprotonation of LHA is required to obtain stable complexes with CL-20. Hydrogen bonds between CL-20 and deprotonated LHA were analyzed applying the atoms in molecules (AIM) theory. An attachment or removal of an electron with respect to the complex does not have significant effect on mutual orientation of the adsorbent in complexes. It was shown that adsorbed CL-20 does not undergo redox transformation and, therefore, adsorption on soil organic matter may be responsible for decrease of the degradation rate of CL-20 in soil. PMID:26814703

  9. The behaviour of incompatible elements during hydrous melting of metasomatized peridotite at 4-6 GPa and 1000 °C-1200 °C

    NASA Astrophysics Data System (ADS)

    Kessel, R.; Fumagalli, P.; Pettke, T.

    2015-11-01

    Trace element behavior during hydrous melting of a metasomatized garnet-peridotite was examined at pressures of 4-6 GPa and temperatures of 1000 °C-1200 °C, conditions appropriate for fluid penetrating the mantle wedge atop the subducting slab. Experiments were performed in a rocking multi-anvil apparatus using a diamond-trap setup. The compositions of the fluid and melt phases were measured using the cryogenic LA-ICP-MS technique. The water-saturated solidus of the K-lherzolite composition is located between 900 °C and 1000 °C at 4 GPa and between 1000 °C and 1100 °C at 5 and 6 GPa. The partition coefficients between fluid or melt and clinopyroxene reveal an asymmetric MREE trough with a minimum at Dy. The clinopyroxene in equilibrium with aqueous fluids is characterized by DUfluid-cpx > DThfluid-cpx while DUmelt-cpx tends to be similar to DThmelt-cpx. The partition coefficients between fluid or melt and garnet reveal very strong light to heavy REE fractionation, DLa/DLu from 95 (hydrous melt) to 1600 (aqueous fluid). The LILE are highly incompatible with partition coefficients > 50. The behavior of HFSE are decoupled, with DZr,Hf close to 1 while DNb,Ta > 10. Garnet is characterized by DUmelt/fluid-garnet < DThmelt/fluid-garnet. A comparison of our experimental partitioning results for trivalent cations as well as the results from the literature and the calculations carried out using the lattice strain model adapted to the presence of water in the bulk system indicates that H2O in the fluid or melt phase has a prominent effect on trace element partitioning. Garnet in mantle rocks in equilibrium with an aqueous fluid is characterized by significantly higher Do(3 +) for REE in the X site of the garnet compared with the partitioning values of the optimal cation in garnet in equilibrium with hydrous melts. Our data show for the first time that the change in the nature of the mobile phase (fluid vs. melt) does affect the affinities of trace elements into the

  10. Extremely sensitive and selective antibodies against the explosive 2,4,6-trinitrotoluene by rational design of a structurally optimized hapten.

    PubMed

    Ramin, Steffen; Weller, Michael G

    2012-02-01

    Antibodies are a promising tool for the fast and selective trace detection of explosives. Unfortunately, the production of high-quality antibodies is not trivial and often expensive. Therefore, excellent antibodies are a rare and limiting resource in fields such as biosensing, environmental analysis, diagnostics, cancer therapy, and proteomics. Here, we report the synthesis, bioconjugation, and application of the structurally optimized hapten 6-(2,4,6-trinitro)-phenylhexanoic acid to improve the selectivity and sensitivity of antibodies for the detection of one of the most important explosives, trinitrotoluene. With a conjugate of bovine serum albumin and a highly purified N-hydroxy-succinimide (NHS)-activated hapten, two rabbits were immunized to obtain polyclonal antibodies. The immunization process was monitored by enzyme-linked immunosorbent assay to gain information about the progress of antibody titer and affinity. Finally, the polyclonal antibodies reached an affinity constant of (5.1 ± 0.6) × 10(9) l/mol (rabbit R1) and (2.3 ± 0.2) × 10(9) l/mol (rabbit R2). The respective assays show a minimum test midpoint (IC(50) value) of 0.1 ± 0.01 µg/l (R1) and 0.2 ± 0.02 µg/l (R2) and a working range of 0.005 to 150 µg/l (R1) and 0.007 to 200 µg/l (R2), which corresponds to more than four orders of magnitude for both. This is quite remarkable for a competitive immunoassay, which is often believed to have a narrow dynamic range. The limit of detection was calculated to 0.6 ng/l (R1) and 1.5 ng/l (R2), which is up to 100 times improvement in relation to the assay of Zeck et al. (1999) on the basis of a monoclonal antibody. The excellent selectivity of the polyclonal antibodies was comprehensively examined by determining the cross-reactivity to common explosives and other nitroaromatics including nitro musk components. The widely held belief that polyclonal antibodies generally display higher cross-reactivities than monoclonals could be disproved.

  11. Transition from steady to unsteady Plinian eruption column: the VEI 5, 4.6 ka Fogo A Plinian eruption, São Miguel, Azores

    NASA Astrophysics Data System (ADS)

    Pensa, Alessandra; Cas, Raymond; Giordano, Guido; Porreca, Massimiliano; Wallenstein, Nicolau

    2015-10-01

    The 4.6 ka Fogo A trachytic Plinian eruption on São Miguel Island, Azores, Portugal, is composed by four main phases: 1) Initial phreatomagmatic activity which emplaced thin surge deposits with accretionary lapilli; 2) fully buoyant steady Plinian activity which generated a prominent trachytic basal fall-out deposit; 3) partial collapsing activity, which led to the emplacement of two trachytic-trachydacitic intra-plinian ignimbrites (pink and black ignimbrites) and associated surge deposits, inter-stratified within two fall-out deposits; 4) vent widening and fully collapsing activity which caused the emplacement of the climactic brown trachydacitic ignimbrite. The deposits of these four main phases have been organised into three members FGA1, FGA2 and FGA3, sub-divided into 15 stratigraphic or emplacement units. The fluctuations from a steady to unsteady Plinian eruption column parallel the change in composition of the magma from trachytic to trachydacitic. Although minimal, the change in composition resulted in a marked change in colour of the juvenile clasts from white at the base (first phase) to pink and light-dark grey banded and black (second and third phases) and to dark brown (fourth phase). Density analysis of juvenile clasts revealed that the change in composition did not significantly affect the density of the juvenile pumice pyroclasts, the vesicularity of which increases from 70% to 85% up through the sequence. The pink and the black intra-plinian ignimbrites were emplaced only, within the narrow paleo-valleys of the southern flank with maximum thicknesses of 9 m and 5 m respectively, transitioning onto adjacent topographic highs where thin veneer surge layers were deposited. The fall-out deposits inter-bedded between the ignimbrites lack basal reverse grading, indicating that the eruption column continued to be sustained during the partial collapses generating the intra-plinian ignimbrites. The climactic dark brown ignimbrite was emplaced radially

  12. Cyclic voltammetry: a tool to quantify 2,4,6-trichloroanisole in aqueous samples from cork planks boiling industrial process.

    PubMed

    Peres, António M; Freitas, Patrícia; Dias, Luís G; Sousa, Mara E B C; Castro, Luís M; Veloso, Ana C A

    2013-12-15

    Chloroanisoles, namely 2,4,6-trichloroanisole, are pointed out as the primary responsible of the development of musty off-flavours in bottled wine, due to their migration from cork stoppers, which results in huge economical losses for wine industry. A prevention step is the detection of these compounds in cork planks before stoppers are produced. Mass spectrometry gas chromatography is the reference method used although it is far beyond economical possibilities of the majority of cork stoppers producers. In this work, a portable cyclic voltammetry approach was used to detect 2,4,6-trichloroanisole extracted from natural cork planks to the aqueous phase during the cork boiling industrial treatment process. Analyses were carried out under ambient conditions, in less than 15 min with a low use of solvent and without any sample pre-treatment. The proposed technique had detection (0.31±0.01 ng/L) and quantification (0.95±0.05 ng/L) limits lower than the human threshold detection level. For blank solutions, without 2,4,6-trichloroanisole addition, a concentration in the order of the quantification limit was estimated (1.0±0.2 ng/L), which confirms the satisfactory performance of the proposed methodology. For aqueous samples from the industrial cork planks boiling procedure, intra-day repeatabilities were lower than 3%, respectively. Also, 2,4,6-trichloroanisole contents in the aqueous samples determined by this novel approach were in good agreement with those obtained by GC-MS (correlation coefficient equal to 0.98), confirming the satisfactory accuracy of the proposed methodology. So, since this novel approach is a fast, low-cost, portable and user-friendly method, it can be an alternative and helpful tool for in-situ industrial applications, allowing accurate detection of releasable 2,4,6-trichloroanisole in an earlier phase of cork stoppers production, which may allow implementing more effective cork treatments to reduce or avoid future 2,4,6-trichloroanisole

  13. CDK4/6 inhibitor PD 0332991 sensitizes acute myeloid leukemia to cytarabine-mediated cytotoxicity

    PubMed Central

    Yang, Chenyi; Boyson, Cynthia A.; Di Liberto, Maurizio; Huang, Xiangao; Hannah, Jeffrey; Dorn, David C.; Moore, Malcolm AS; Chen-Kiang, Selina; Zhou, Pengbo

    2015-01-01

    Cyclin-dependent kinase (CDK)4 and CDK6 are frequently overexpressed or hyperactivated in human cancers. Targeting CDK4/CDK6 in combination with cytotoxic killing therefore represents a rational approach to cancer therapy. By selective inhibition of CDK4/CDK6 with PD 0332991, which leads to early G1 arrest and synchronous S phase entry upon release of the G1 block, we have developed a novel strategy to prime acute myeloid leukemia (AML) cells for cytotoxic killing by cytarabine (Ara-C). This sensitization is achieved in part through enrichment of S-phase cells, which maximizes the AML populations for Ara-C incorporation into replicating DNA to elicit DNA damage. Moreover, PD 0332991 trigged apoptosis of AML cells through inhibition of the homeobox (HOX)A9 oncogene expression, reducing the transcription of its target PIM1. Reduced PIM1 synthesis attenuates PIM1-mediated phosphorylation of the pro-apoptotic BAD and activates BAD-dependent apoptosis. In vivo, timely inhibition of CDK4/CDK6 by PD 0332991 and release profoundly suppresses tumor growth in response to reduced doses of Ara-C in a xenograft AML model. Collectively, these data suggest selective and reversible inhibition of CDK4/CDK6 as an effective means to enhance Ara-C killing of AML cells at reduced doses, which has implications for the treatment of elderly AML patients who are unable to tolerate high dose Ara-C therapy. PMID:25744718

  14. Task 4.6 -- Biodesulfurization. Semi-annual report, January 1--June 30, 1995

    SciTech Connect

    Olson, E.S.

    1995-12-31

    The main focus in this task is the application of desulfurization enzymes to remove sulfur from crude oil, diesel fuel, or resid precursors for needle cokes. The most important question to be answered is how to utilize the Rhodococcus desulfurization complex in a nonaqueous solvent or medium, such as the oil itself. Successful application of nonaqueous enzymology to this problem will involve finding ways to stabilize the active conformations of the enzymes and provide for easy recovery of the enzymes, perhaps in an immobilized-enzyme packed-bed reactor. Understanding the desulfurization activity will require that they determine the regulatory and mechanistic properties of the enzymes. In the previous period, methods were developed for recovering larger amounts of the metabolic intermediates that would at the same time preserve all the labeling from oxygen isotopes by preventing exchange and avoiding displacement during derivatization for the gas chromatography/mass spectroscopy analysis. In this period, methods were investigated for conversion of the sulfonate and the sulfite trapped on the resin to alkyl derivatives that could by analyzed by GC/MS and GC/Fourier transform infrared to determine the oxygen isotopic labeling. This information is needed to complete the understanding of the last steps occurring in the complex desulfurization system in the bacterium. The methods employed included treatment with diazomethane and trimethyloxonium tetrafluoroborate.

  15. Uptake of 2,4,6-Trinitrotoluene (TNT) by Vetiver grass (Vetiviera ziznoides L.) -- Preliminary results from a hydroponic study

    NASA Astrophysics Data System (ADS)

    Shakya, K. M.; Sarkar, D.; Datta, R.; Makris, K.; Pachanoor, D.

    2006-05-01

    2,4,6-Trinitrotoluene(TNT) is a potent mutagen and a Group C human carcinogen that has been widely used to produce munitions and explosives. As a result, vast areas that have been previously used as military ranges, munition burning and open detonation sites have been heavily contaminated with TNT. Conventional remedial activities in such contaminated sites commonly rely on methods such as incineration, land filling and soil composting. Phytoremediation offers a cost-effective solution, utilizing plants to phytoextract TNT from the contaminated soil. We propose the use of vetiver grass (Vetiveria zizanoides) to remove TNT from such contaminated soils. Vetiver is a fast-growing and adaptive grass, enabling its use in TNT-contaminated sites in a wide variety of soil types and climate. We also hypothesized that TNT removal by vetiver grass will be enhanced by utilizing a chaotropic agent (urea) to alter rhizosphere/root hair chemical environment. The objectives of this preliminary hydroponic study were: i) to investigate the effectiveness of vetiver grass in removing TNT from solution, and ii) to evaluate the use of a common agrochemical (urea) in enhancing TNT removal by vetiver grass. Vetiver plants were grown in a hydroponic system with five different TNT concentrations (0, 5, 10, 25, and 50 mg TNT L-1) and three urea concentrations (0, 0.01 and 0.1%). A plant density of 10 g L-1 and three replicate vessels per treatment were used. Aliquots were collected at several time intervals up to 192 hour, and were analyzed for TNT with HPLC. Results showed that vetiver was able to remove TNT from hydroponic solutions. The overall magnitude and kinetics of TNT removal by vetiver grass was enhanced in the presence of urea. TNT removal kinetics depended on TNT and urea initial concentrations, suggestive of second-order kinetic reactions. Preliminary results are encouraging, but in need for verification using more detailed studies involving TNT-contaminated soils. Ongoing

  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. Selective detection of 2,4,6-trinitrophenol based on a fluorescent nanoscale bis(8-hydroxyquinoline) metal complex.

    PubMed

    Lv, Xiao-Jun; Qi, Liang; Gao, Xiang-Yu; Wang, Huan; Huo, Yuan; Zhang, Zhi-Qi

    2016-04-01

    The reliable and accurate detection of explosives such as 2,4,6-trinitrophenol (TNP) and 2,4,6-trinitrotoluene (TNT) is in high demand for homeland security and public safety. Although extremely high sensitivity towards TNT has been demonstrated, detection of TNP remains a challenge. In this work, a fluorescent nanoscale complex composed of bis(8-hydroxyquinoline) and Al(3+) ions has been prepared, characterized and applied in detection of TNP. This complex exhibits the ability to sense the nitro explosive TNP via a fluorescence quenching mechanism with high selectivity. A simple paper test system for the rapid monitoring of TNP was also investigated. The results show that Bhq-Al is a quite ideal sensing material for trace-level detection of TNP. PMID:26838414

  18. Design, synthesis, and evaluation of 4,6-diaminonicotinamide derivatives as novel and potent immunomodulators targeting JAK3.

    PubMed

    Nakajima, Yutaka; Aoyama, Naohiro; Takahashi, Fumie; Sasaki, Hiroshi; Hatanaka, Keiko; Moritomo, Ayako; Inami, Masamichi; Ito, Misato; Nakamura, Koji; Nakamori, Fumihiro; Inoue, Takayuki; Shirakami, Shohei

    2016-10-01

    In organ transplantation, T cell-mediated immune responses play a key role in the rejection of allografts. Janus kinase 3 (JAK3) is specifically expressed in hematopoietic cells and associated with regulation of T cell development via interleukin-2 signaling pathway. Here, we designed novel 4,6-diaminonicotinamide derivatives as immunomodulators targeting JAK3 for prevention of transplant rejection. Our optimization of C4- and C6-substituents and docking calculations to JAK3 protein confirmed that the 4,6-diaminonicotinamide scaffold resulted in potent inhibition of JAK3. We also investigated avoidance of human ether-a-go-go related gene (hERG) inhibitory activity. Selected compound 28 in combination with tacrolimus prevented allograft rejection in a rat heterotopic cardiac transplantation model. PMID:27544589

  19. Quenching of triplet benzophenone by 2,4,6-tri-tert-butylphenol and formation of its phenoxy radical

    SciTech Connect

    Kajii, Y.; Fujita, M.; Hiratsuka, H.; Obi, K.; Mori, Y.; Tanaka, I.

    1987-05-21

    Quenching of triplet benzophenone in benzene by 2,4,6-tri-tert-butylphenol is studied by the nanosecond laser flash photolysis. The quenching rate constant of triplet benzophenone has been determined to be 6.2 x 10/sup 8/ M/sup -1/ s/sup -1/, which is slightly smaller than the diffusion-controlled limit. The quenching reaction produces benzophenone ketyl and 2,4,6-tri-tert-butylphenoxy radicals simultaneously. The transient spectrum of the latter radical shows characteristic structured bands around 400 nm and a broad absorption between 600 and 700 nm. The extinction coefficient at the peak lambda/sub max/ = 670 nm of red absorption has been estimated to be 1200 M/sup -1/ cm/sup -1/.

  20. 5-(3,4-Dimethyl-benzyl-idene)-2,2-dimethyl-1,3-dioxane-4,6-dione.

    PubMed

    Zeng, Wu-Lan

    2011-06-01

    The title compound, C(15)H(16)O(4), was prepared by the reaction of 2,2-dimethyl-1,3-dioxane-4,6-dione and 3,4-dimethyl-benzaldehyde in ethanol. The 1,3-dioxane ring exhibits an envelope conformation. In the crystal, mol-ecules are linked by weak inter-molecular C-H⋯O hydrogen bonds, forming chains parallel to the b axis. PMID:21754745