WorldWideScience

Sample records for atrazine pc code

  1. HOTSPOT Health Physics codes for the PC

    Energy Technology Data Exchange (ETDEWEB)

    Homann, S.G.

    1994-03-01

    The HOTSPOT Health Physics codes were created to provide Health Physics personnel with a fast, field-portable calculation tool for evaluating accidents involving radioactive materials. HOTSPOT codes are a first-order approximation of the radiation effects associated with the atmospheric release of radioactive materials. HOTSPOT programs are reasonably accurate for a timely initial assessment. More importantly, HOTSPOT codes produce a consistent output for the same input assumptions and minimize the probability of errors associated with reading a graph incorrectly or scaling a universal nomogram during an emergency. The HOTSPOT codes are designed for short-term (less than 24 hours) release durations. Users requiring radiological release consequences for release scenarios over a longer time period, e.g., annual windrose data, are directed to such long-term models as CAPP88-PC (Parks, 1992). Users requiring more sophisticated modeling capabilities, e.g., complex terrain; multi-location real-time wind field data; etc., are directed to such capabilities as the Department of Energy`s ARAC computer codes (Sullivan, 1993). Four general programs -- Plume, Explosion, Fire, and Resuspension -- calculate a downwind assessment following the release of radioactive material resulting from a continuous or puff release, explosive release, fuel fire, or an area contamination event. Other programs deal with the release of plutonium, uranium, and tritium to expedite an initial assessment of accidents involving nuclear weapons. Additional programs estimate the dose commitment from the inhalation of any one of the radionuclides listed in the database of radionuclides; calibrate a radiation survey instrument for ground-survey measurements; and screen plutonium uptake in the lung (see FIDLER Calibration and LUNG Screening sections).

  2. New versions of VENTURE/PC, a multigroup, multidimensional diffusion-depletion code system

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, A.; Huria, H.C. (Univ. of Cincinnati, OH (United States))

    1990-01-01

    VENTURE/PC is a microcomputer version of the BOLD VENTURE code system developed over a period of years at Oak Ridge National Laboratory (ORNL). It is a very complete and flexible multigroup, multidimensional, diffusion-depletion code system, which was developed for the Idaho National Engineering Laboratory personal computer (PC) based reactor physics and radiation shielding analysis package. The major characteristics of the code system were reported previously. Since that time, new versions of the code system have been developed. These new versions were designed to speed the convergence process, simplify the input stream, and extend the code to the state-of-the-art 32-bit microcomputers. The 16-bit version of the code is distributed by the Radiation Shielding Information Center (RSIC) at ORNL. The code has received widespread usage.

  3. Identification and functional characterization of G6PC2 coding variants influencing glycemic traits define an effector transcript at the G6PC2-ABCB11 locus.

    Directory of Open Access Journals (Sweden)

    Anubha Mahajan

    2015-01-01

    Full Text Available Genome wide association studies (GWAS for fasting glucose (FG and insulin (FI have identified common variant signals which explain 4.8% and 1.2% of trait variance, respectively. It is hypothesized that low-frequency and rare variants could contribute substantially to unexplained genetic variance. To test this, we analyzed exome-array data from up to 33,231 non-diabetic individuals of European ancestry. We found exome-wide significant (P<5×10-7 evidence for two loci not previously highlighted by common variant GWAS: GLP1R (p.Ala316Thr, minor allele frequency (MAF=1.5% influencing FG levels, and URB2 (p.Glu594Val, MAF = 0.1% influencing FI levels. Coding variant associations can highlight potential effector genes at (non-coding GWAS signals. At the G6PC2/ABCB11 locus, we identified multiple coding variants in G6PC2 (p.Val219Leu, p.His177Tyr, and p.Tyr207Ser influencing FG levels, conditionally independent of each other and the non-coding GWAS signal. In vitro assays demonstrate that these associated coding alleles result in reduced protein abundance via proteasomal degradation, establishing G6PC2 as an effector gene at this locus. Reconciliation of single-variant associations and functional effects was only possible when haplotype phase was considered. In contrast to earlier reports suggesting that, paradoxically, glucose-raising alleles at this locus are protective against type 2 diabetes (T2D, the p.Val219Leu G6PC2 variant displayed a modest but directionally consistent association with T2D risk. Coding variant associations for glycemic traits in GWAS signals highlight PCSK1, RREB1, and ZHX3 as likely effector transcripts. These coding variant association signals do not have a major impact on the trait variance explained, but they do provide valuable biological insights.

  4. Identification and Functional Characterization of G6PC2 Coding Variants Influencing Glycemic Traits Define an Effector Transcript at the G6PC2-ABCB11 Locus

    Science.gov (United States)

    Mahajan, Anubha; Sim, Xueling; Ng, Hui Jin; Manning, Alisa; Rivas, Manuel A.; Highland, Heather M.; Locke, Adam E.; Grarup, Niels; Im, Hae Kyung; Cingolani, Pablo; Flannick, Jason; Fontanillas, Pierre; Fuchsberger, Christian; Gaulton, Kyle J.; Teslovich, Tanya M.; Rayner, N. William; Robertson, Neil R.; Beer, Nicola L.; Rundle, Jana K.; Bork-Jensen, Jette; Ladenvall, Claes; Blancher, Christine; Buck, David; Buck, Gemma; Burtt, Noël P.; Gabriel, Stacey; Gjesing, Anette P.; Groves, Christopher J.; Hollensted, Mette; Huyghe, Jeroen R.; Jackson, Anne U.; Jun, Goo; Justesen, Johanne Marie; Mangino, Massimo; Murphy, Jacquelyn; Neville, Matt; Onofrio, Robert; Small, Kerrin S.; Stringham, Heather M.; Syvänen, Ann-Christine; Trakalo, Joseph; Abecasis, Goncalo; Bell, Graeme I.; Blangero, John; Cox, Nancy J.; Duggirala, Ravindranath; Hanis, Craig L.; Seielstad, Mark; Wilson, James G.; Christensen, Cramer; Brandslund, Ivan; Rauramaa, Rainer; Surdulescu, Gabriela L.; Doney, Alex S. F.; Lannfelt, Lars; Linneberg, Allan; Isomaa, Bo; Tuomi, Tiinamaija; Jørgensen, Marit E.; Jørgensen, Torben; Kuusisto, Johanna; Uusitupa, Matti; Salomaa, Veikko; Spector, Timothy D.; Morris, Andrew D.; Palmer, Colin N. A.; Collins, Francis S.; Mohlke, Karen L.; Bergman, Richard N.; Ingelsson, Erik; Lind, Lars; Tuomilehto, Jaakko; Hansen, Torben; Watanabe, Richard M.; Prokopenko, Inga; Dupuis, Josee; Karpe, Fredrik; Groop, Leif; Laakso, Markku; Pedersen, Oluf; Florez, Jose C.; Morris, Andrew P.; Altshuler, David; Meigs, James B.; Boehnke, Michael; McCarthy, Mark I.; Lindgren, Cecilia M.; Gloyn, Anna L.

    2015-01-01

    Genome wide association studies (GWAS) for fasting glucose (FG) and insulin (FI) have identified common variant signals which explain 4.8% and 1.2% of trait variance, respectively. It is hypothesized that low-frequency and rare variants could contribute substantially to unexplained genetic variance. To test this, we analyzed exome-array data from up to 33,231 non-diabetic individuals of European ancestry. We found exome-wide significant (P<5×10-7) evidence for two loci not previously highlighted by common variant GWAS: GLP1R (p.Ala316Thr, minor allele frequency (MAF)=1.5%) influencing FG levels, and URB2 (p.Glu594Val, MAF = 0.1%) influencing FI levels. Coding variant associations can highlight potential effector genes at (non-coding) GWAS signals. At the G6PC2/ABCB11 locus, we identified multiple coding variants in G6PC2 (p.Val219Leu, p.His177Tyr, and p.Tyr207Ser) influencing FG levels, conditionally independent of each other and the non-coding GWAS signal. In vitro assays demonstrate that these associated coding alleles result in reduced protein abundance via proteasomal degradation, establishing G6PC2 as an effector gene at this locus. Reconciliation of single-variant associations and functional effects was only possible when haplotype phase was considered. In contrast to earlier reports suggesting that, paradoxically, glucose-raising alleles at this locus are protective against type 2 diabetes (T2D), the p.Val219Leu G6PC2 variant displayed a modest but directionally consistent association with T2D risk. Coding variant associations for glycemic traits in GWAS signals highlight PCSK1, RREB1, and ZHX3 as likely effector transcripts. These coding variant association signals do not have a major impact on the trait variance explained, but they do provide valuable biological insights. PMID:25625282

  5. Applying Hilbert spatial ordering code to partition massive spatial data in PC cluster system

    Science.gov (United States)

    Wang, Yongjie; Hong, Xinlan; Meng, Lingkui; Zhao, Chunyu

    2006-10-01

    In order to handle massive spatial data quickly and efficiently, a superior solution is to store and handle them in parallel spatial database management systems under the environment of PC cluster at present, and thus its spatial partitioning strategy of data needs solving first. Hilbert spatial ordering code based on Hilbert space-filling curve is an excellent linear mapping method, and gets wider and wider applications in processing spatial data. After studying Hilbert curve, this paper proposes a new and efficient algorithm for the generation of Hilbert code, and it has overcome drawbacks of the traditional algorithm. Then Hilbert code is applied to spatial partitioning with the method of cluster analysis, and a concrete method is given, which fully considers characteristics of spatial data, such as the aggregation of spatial data, reduces the time of disks accesses, and achieves better performance by experiments than the compulsory partitioning of ORACLE Spatial based on X coordinate values and (or) Y coordinate values in subsequent parallel processing of spatial data.

  6. Beta.-glucosidase coding sequences and protein from orpinomyces PC-2

    Science.gov (United States)

    Li, Xin-Liang; Ljungdahl, Lars G.; Chen, Huizhong; Ximenes, Eduardo A.

    2001-02-06

    Provided is a novel .beta.-glucosidase from Orpinomyces sp. PC2, nucleotide sequences encoding the mature protein and the precursor protein, and methods for recombinant production of this .beta.-glucosidase.

  7. Improvements in the Monte Carlo code for simulating 4πβ(PC)–γ coincidence system measurements

    Energy Technology Data Exchange (ETDEWEB)

    Dias, M.S., E-mail: msdias@ipen.br [Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000 São Paulo, SP (Brazil); Takeda, M.N. [Universidade Santo Amaro, UNISA Rua Prof. Enéas da Siqueira Neto 340, 04829-300 São Paulo, SP (Brazil); Toledo, F.; Brancaccio, F.; Tongu, M.L.O.; Koskinas, M.F. [Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000 São Paulo, SP (Brazil)

    2013-01-11

    A Monte Carlo simulation code known as ESQUEMA has been developed by the Nuclear Metrology Laboratory (Laboratório de Metrologia Nuclear—LMN) in the Nuclear and Energy Research Institute (Instituto de Pesquisas Energéticas e Nucleares—IPEN) to be used as a benchmark for radionuclide standardization. The early version of this code simulated only β−γ and ec−γ emitters with reasonably high electron and X-ray energies. To extend the code to include other radionuclides and enable the code to be applied to software coincidence counting systems, several improvements have been made and are presented in this work. -- Highlights: ► Improvements to the Monte Carlo code ESQUEMA are described. ► The experimental extrapolation curve was compared to Monte Carlo simulation. ► Eu-152 was standardized by 4π(PC)β-γ coincidence system and compared to Monte Carlo simulation. ► 4π proportional counter gamma-ray efficiency was calculated by MCNPX and compared with experiment. ► X-ray and positron decay emitters were included in the simulation.

  8. Development of environmental dose assessment system (EDAS) code of PC version

    Energy Technology Data Exchange (ETDEWEB)

    Taki, Mitsumasa; Kikuchi, Masamitsu; Kobayashi, Hideo; Yamaguchi, Takenori [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-05-01

    A computer code (EDAS) was developed to assess the public dose for the safety assessment to get the license of nuclear reactor operation. This code system is used for the safety analysis of public around the nuclear reactor in normal operation and severe accident. This code was revised and composed for personal computer user according to the Nuclear Safety Guidelines reflected the ICRP1990 recommendation. These guidelines are revised by Nuclear Safety Commission on March, 2001, which are 'Weather analysis guideline for the safety assessment of nuclear power reactor', 'Public dose around the facility assessment guideline corresponding to the objective value for nuclear power light water reactor' and 'Public dose assessment guideline for safety review of nuclear power light water reactor'. This code has been already opened for public user by JAERI, and English version code and user manual are also prepared. This English version code is helpful for international cooperation concerning the nuclear safety assessment with JAERI. (author)

  9. Ascorbic acid induced atrazine degradation.

    Science.gov (United States)

    Hou, Xiaojing; Huang, Xiaopeng; Ai, Zhihui; Zhao, Jincai; Zhang, Lizhi

    2017-04-05

    In this study, we systematically investigated the degradation efficiency and the degradation mechanism of atrazine in the presence of ascorbic acid at different pH values. Although atrazine could be degraded by ascorbic acid in a wide pH range from 4 to 12, its degradation under either acidic (pH≤4) or alkaline (pH≥12) condition was more efficient than under neutral condition (pH=7). This pH dependent atrazine degradation was related to the reactive characteristic of atrazine and the reductive activity of ascorbic acid. The ascorbic acid induced atrazine degradation pathways at different pH were investigated by comparing the atrazine degradation intermediates with liquid chromatography-mass spectrometry, high performance liquid chromatography and ion chromatography. It was found that more products were detected in presence of ascorbic acid at alkaline condition. The appearance of chloride ions confirmed the dechlorination of atrazine by ascorbic acid in the absence of molecular oxygen, while its dechlorination efficiency reached highest at pH 12. These results can shed light on the application of AA for the organic pollutant remediation. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Introduction of atrazine degrader to enhance rhizodegradation of atrazine

    Science.gov (United States)

    Introducing atrazine (ATR) degraders into riparian vegetative buffer strips (VBS) can be a promising bioremediation approach to accelerate the degradation of ATR and its degradation products deposited into VBS by surface runoff. A growth chamber study was conducted to investigated the synergistic ef...

  11. Atrazine retention and transport in soils.

    Science.gov (United States)

    Ma, L; Selim, H M

    1996-01-01

    No pesticide has been studied as extensively as atrazine. The study of atrazine has contributed to our general understanding of the behavior of pesticides in soils. New knowledge and concepts were evaluated, such as atrazine adsorption kinetics, desorption hysteresis, and preferential flow. Corresponding conceptual models were also proposed to explain the behavior of atrazine in soils. Atrazine adsorption-desorption is the major process affecting atrazine behavior in soils and is mainly affected by organic matter and soil pH. Atrazine in soils is subject to biological and chemical degradations. Hydroxyatrazine, the chemical degradation product, is more strongly adsorbed to soil than atrazine. Deethylatrazine and deisopropylatrazine, the major biological degradation products, are more mobile than atrazine. Hydrolysis of atrazine is soil-surface catalyzed and favored by low soil pH. The overall dissipation rate of atrazine was found to be pseudo first-order. Two distinct and different processes are involved in atrazine movement: slow transport through the soil matrix and rapid movement through macropores. The first process is controlled by adsorption kinetics and degradation reactions and can be well explained by models based on chemical heterogeneity, such as the two-site models and second-order models. The second flow process results from preferential flow through large pores and can be explained by physical nonequilibrium models such as the mobile-immobile and two-flow domain models. Because both processes coexist in atrazine transport, coupling of physical and chemical nonequilibrium models is often necessary and has shown promise in atrazine transport modeling. However, more efforts are needed in estimating model parameters and in developing management-oriented models.

  12. Melamine-based organoclay to sequester atrazine.

    Science.gov (United States)

    Neitsch, Susan L; McInnes, Kevin J; Senseman, Scott A; White, G Norman; Simanek, Eric E

    2006-07-01

    Sequestration of aqueous atrazine by organoclays prepared from the surfactant 6-piperazin-1-yl-N,N'-bis-(1,1,3,3-tetramethyl-butyl)-(1,3,5)triazine-2,4-diamine and Gonzales bentonite was assessed using 14C-labeled atrazine. Organoclays with varying ratios of surfactant to clay were evaluated with respect to their ability to sequester atrazine from an aqueous solution. Organoclays containing 100-200 g kg-1 surfactant on a total weight basis provided the most efficient adsorption of atrazine, with apparent KOC values exceeding 5000 l kg-1 at these loading fractions. Less than 12% of sequestered atrazine was released during four sequential day long washings, supporting our expectation that the majority of the reaction of atrazine with the surfactant lead to irreversible chemical bond formation through nucleophilic aromatic substitution.

  13. Atrazine removal in Danish anaerobic aquifers

    DEFF Research Database (Denmark)

    Pedersen, Philip Grinder; Arildskov, N.P.; Albrechtsen, Hans-Jørgen

    2002-01-01

    The pesticide atrazine (6-chloro-N-2-ethyl-N-4-isopropyl-1,3,5-triazine -2,4-diamine) was removed from the water phase in anaerobic laboratory batch incubations with sediment and groundwater from a number of Danish anaerobic aquifers, but not in incubations from aerobic aquifers. The removal...... process was abiotic since atrazine was also removed from microbially inhibited autoclaved and chloroform amended controls, although in controls amended with mercury, atrazine removal was slowed down. (ring-U-C-14)- atrazine amended samples showed no mineralization to (CO2)-C-14 or transformation...... to soluble degradation products, indicating that a slow sorption process was responsible for the atrazine removal. Approximately 20% of the applied C-14-atrazine was present in a non-extractable residual sediment bound fraction, indicating the slow sorption process to be in part irreversible...

  14. New aspects on atrazine biodegradation

    OpenAIRE

    Sene, Luciane; Converti, Attilio; Secchi, Geslaine Aparecida Ribeiro; Simão, Rita de Cássia Garcia

    2010-01-01

    The world practice of using agrochemicals for long periods, in an indiscriminated and abusive way, has been a concern of the authorities involved in public health and sustainability of the natural resources, as a consequence of environmental contamination. Agrochemicals refer to a broad range of insecticides, fungicides and herbicides, and among them stands out atrazine, a herbicide intensively used in sugarcane, corn and sorghum cultures, among others. Researches have demonstrated that atraz...

  15. New aspects on atrazine biodegradation

    Directory of Open Access Journals (Sweden)

    Luciane Sene

    2010-04-01

    Full Text Available The world practice of using agrochemicals for long periods, in an indiscriminated and abusive way, has been a concern of the authorities involved in public health and sustainability of the natural resources, as a consequence of environmental contamination. Agrochemicals refer to a broad range of insecticides, fungicides and herbicides, and among them stands out atrazine, a herbicide intensively used in sugarcane, corn and sorghum cultures, among others. Researches have demonstrated that atrazine has toxic effects in algae, aquatic plants, aquatic insects, fishes and mammals. Due to the toxicity and persistence of atrazine in the environment, the search of microbial strains capable of degrading it is fundamental to the development of bioremediation processes, as corrective tools to solve the current problems of the irrational use of agrochemicals. This review relates the main microbial aspects and research on atrazine degradation by isolated microbial species and microbial consortia, as well as approaches on the development of techniques for microbial removal of atrazine in natural environments.A prática mundial do uso de agroquímicos por períodos extensos, de maneira indiscriminada e abusiva, tem mobilizado as autoridades envolvidas em saúde pública e sustentabilidade de fontes naturais, como uma conseqüência da contaminação ambiental. Agroquímicos referem-se a uma ampla variedade de inseticidas, fungicidas e herbicidas, entre estes a atrazina, um herbicida intensivamente usado em culturas de cana-de-açúcar, milho, sorgo, entre outros. Pesquisadores têm demonstrado que a atrazina tem efeitos tóxicos em algas, plantas aquáticas, insetos aquáticos, peixes e mamíferos. Devido à toxicidade e à persistência da atrazina no ambiente, a busca de linhagens microbianas capazes de degradá-la é fundamental para o desenvolvimento de processos de biorremediação, com uma ferramenta corretiva para solucionar problemas decorridos do uso

  16. PC Pricer

    Data.gov (United States)

    U.S. Department of Health & Human Services — The PC Pricer is a tool used to estimate Medicare PPS payments. The final payment may not be precise to how payments are determined in the Medicare claims processing...

  17. Effect of Fluazifopbutyl and Atrazine/Metolachlor (Tank Mixed) for ...

    African Journals Online (AJOL)

    kg ai/ha (recommended rate). Atrazine/Metolachlor 1.5kg ai/ha(tank mixed), mixture of Atrazine/Metolachlor + Fluazifopbutyl at rate 1.0kg ai/ha + 1.75kg ai/ha, Atrazine/Metolachlor 2.5 kg ai/ha, Atrazine/Metolachlor 3.5 kg ai/ha, Manual weeding ...

  18. 76 FR 56754 - Petition Requesting Ban on Use and Production of Atrazine; Notice of Availability

    Science.gov (United States)

    2011-09-14

    ..., conservation, and wildlife organizations (NAICS code 813312). This listing is not intended to be exhaustive... concern for impacts on amphibians and other aquatic species as well as concern for potential risks to human health. Information on EPA's regulation of atrazine with regard to amphibians, ] aquatic...

  19. Concentrations of glyphosate and atrazine compounds in 100 Midwest United States streams in 2013

    Science.gov (United States)

    Mahler, Barbara J.; Van Metre, Peter C.; Burley, Thomas E.; Loftin, Keith A.; Meyer, Michael T.; Nowell, Lisa H.

    2016-01-01

    Temporal patterns in glyphosate and atrazine concentrations were measured weekly by the U.S. Geological Survey (USGS) during the 2013 growing season in 100 small streams in the Midwestern United States. Concentrations also were measured every 2 days at a subset of 8 of the sites, all located in Missouri. Glyphosate was detected more frequently in urban streams than in agricultural streams, and at concentrations similar to those in streams with high agricultural land use in the watershed. In contrast, atrazine was detected more frequently and at higher concentrations in agricultural streams than in urban streams. This data release provides watershed characteristics and 2013 glyphosate and atrazine compound concentrations used in the analysis presented in the journal article “Similarities and differences in temporal fluctuations in glyphosate and atrazine in small Midwestern streams (USA) during the 2013 growing season,” by BJ Mahler, PC Van Metre, TE Burley, KA Loftin, MT Meyer, and LH Nowell, http://dx.doi.org/10.1016/j.scitotenv.2016.10.236.

  20. Raster dataset showing the probability of detecting atrazine/desethyl-atrazine in ground water in Colorado, hydrogeomorphic regions included and atrazine use estimates not included.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is one of eight datasets produced by this study. Four of the datasets predict the probability of detecting atrazine and(or) desethyl-atrazine (a...

  1. Raster dataset showing the probability of detecting atrazine/desethyl-atrazine in ground water in Colorado, hydrogeomorphic regions and atrazine use estimates included.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is one of eight datasets produced by this study. Four of the datasets predict the probability of detecting atrazine and(or) desethyl-atrazine (a...

  2. Raster dataset showing the probability of detecting atrazine/desethyl-atrazine in ground water in Colorado, hydrogeomorphic regions and atrazine use estimates not included.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is one of eight datasets produced by this study. Four of the datasets predict the probability of detecting atrazine and(or) desethyl-atrazine (a...

  3. Raster dataset showing the probability of detecting atrazine/desethyl-atrazine in ground water in Colorado, hydrogeomorphic regions not included and atrazine use estimates included.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is one of eight datasets produced by this study. Four of the datasets predict the probability of detecting atrazine and(or) desethyl-atrazine (a...

  4. Microbial Utilization Of The Hydrocarbon Components Of Atrazine In ...

    African Journals Online (AJOL)

    Bacterial atrazine-degraders were: Micrococcus sp., Bacillus sp. Enterobacter Sp and Pseudomonas sp. while fungal atrazine-degraders were: Aspergillus fumigatus, A. niger, Penincillium sp and Fusarium sp. Keywords: Agriculture, Atrazine, Biodegradation, Herbicides, Sustainable development, Xenobiotic African Journal ...

  5. Determining potential for microbial atrazine degradation in agricultural drainage ditches.

    Science.gov (United States)

    Tyler, Heather L; Khalid, Sheza; Jackson, Colin R; Moore, Matthew T

    2013-01-01

    Passage of agricultural runoff through vegetated drainage ditches has been shown to reduce the amount of pesticides, such as atrazine, exiting out of agricultural watersheds. Previous studies have found that microbial communities in soil from fields treated with atrazine display enhanced rates of atrazine degradation. However, no studies have examined the potential for atrazine degradation in ditches used to drain these lands. The purpose of the current study was to determine the potential of the drainage ditch soil microbial community for atrazine degradation. Soil samples were collected from fields and adjacent drainage ditches and from nonagricultural land with no previous exposure to atrazine. Polymerase chain reaction analysis indicated widespread presence of atrazine degradation genes in fields and ditches. Potential for degradation was determined by following the decrease of atrazine in spiked soil samples over a 28-d incubation period. Greater than 95% of atrazine was degraded in field and ditch soils, whereas only 68.5 ± 1.3% was degraded in the nonagricultural control. Comparison with autoclaved soil samples indicated the primary mechanism of atrazine degradation in agricultural soils was microbially mediated, whereas its breakdown in nonagricultural soil appeared to be the byproduct of abiotic processes. Therefore, microbial communities in drainage ditch sediments have the potential to play a role in atrazine removal from agricultural runoff by breaking down atrazine deposited in sediments and limiting the amount of this herbicide carried into downstream ecosystems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  6. AMPS/PC - AUTOMATIC MANUFACTURING PROGRAMMING SYSTEM

    Science.gov (United States)

    Schroer, B. J.

    1994-01-01

    The AMPS/PC system is a simulation tool designed to aid the user in defining the specifications of a manufacturing environment and then automatically writing code for the target simulation language, GPSS/PC. The domain of problems that AMPS/PC can simulate are manufacturing assembly lines with subassembly lines and manufacturing cells. The user defines the problem domain by responding to the questions from the interface program. Based on the responses, the interface program creates an internal problem specification file. This file includes the manufacturing process network flow and the attributes for all stations, cells, and stock points. AMPS then uses the problem specification file as input for the automatic code generator program to produce a simulation program in the target language GPSS. The output of the generator program is the source code of the corresponding GPSS/PC simulation program. The system runs entirely on an IBM PC running PC DOS Version 2.0 or higher and is written in Turbo Pascal Version 4 requiring 640K memory and one 360K disk drive. To execute the GPSS program, the PC must have resident the GPSS/PC System Version 2.0 from Minuteman Software. The AMPS/PC program was developed in 1988.

  7. Surfactant-modified bentonite clays: preparation, characterization, and atrazine removal.

    Science.gov (United States)

    Dutta, Anirban; Singh, Neera

    2015-03-01

    Bentonite clay was modified using quaternary ammonium cations, viz. phenyltrimethylammonium (PTMA), hexadecyltrimethylammonium (HDTMA), trioctylmethylammonium (TOMA) [100 % of cation exchange capacity of clay], and stearylkonium (SK) [100 % (SK-I) and 250 % (SK-II) of cation exchange capacity of clay]. The organoclays were characterized using X-ray diffraction (XRD), infrared (IR) spectroscopy, and scanning electron microscopy (SEM). Atrazine adsorption on modified clays was studied using a batch method. Bentonite clay was a poor adsorbent of atrazine as 9.4 % adsorption was observed at 1 μg mL(-1) atrazine concentration. Modification of clay by PTMA cation did not improve atrazine adsorption capacity. However, atrazine adsorption in HDTMA-, TOMA-, and SK-bentonites varied between 49 and 72.4 % and data fitted well to the Freundlich adsorption isotherm (R > 0.96). Adsorption of atrazine in organoclays was nonlinear and slope (1/n) values were organoclays showed hysteresis and TOMA- and SK-I-bentonites were the best organoclays to retain the adsorbed atrazine. Organoclays showed better atrazine removal from wastewater than an aqueous solution. The synthesized organoclays may find application in soil and water decontamination and as a carrier for atrazine-controlled released formulations.

  8. Evaluation of Crops Sensitivity to Atrazine Soil Residual

    Directory of Open Access Journals (Sweden)

    E Izadi

    2012-02-01

    Full Text Available Abstract In order to study the sensitivity of 9 crops to atrazine soil residual, two separate experiments were conducted in field and greenhouse conditions. First experiment was conducted in a field with treated soil by atrazine based on split plot and the results evaluated in greenhouse conditions. Treatments in the field experiment included two organic manure application rates (0 and 50 t/ha as main plots and 2 atrazine application rates (2 and 4 kg/ha atrazine a.i. as sob plots. After corn harvesting soil was sampled at 0-15 cm surface layer in each plots in 15 points, after mixing the samples. Wheat, barley, sugar beet, pea, lens and colza planted in pots at greenhouse. Second experiment conducted in greenhouse conditions for evaluation of atrazine soil residual in completely randomized design. Treatments included atrazine soil residual concentrations (0, 0.2, 0.5, 1, 5, 10 and 15 mg/kg soil and crops included wheat, barley, sugar beet, pea, lens, rape, bean and tomato. Results showed that atrazine residue had no effect on crops growth in field experiment treated with atrazine. It seems that atrazine residue in filed soil is lower that its damage threshold for crops or maybe for its fast removal in field than in control conditions. But in bioassay experiment (greenhouse experiment crops response to atrazine residues were different. Results showed that onion and pea were most susceptible ant tolerant crops between studied species and based of ED50 parameter the other crops tolerance to total residue ranked as: pea< bean< lentil< sugar beet< tomato< barley< wheat< rape< onion. Keywords: Atrazine residue, Pea, Bean, Lentil, Sugar beet, Barley, Wheat, Rape, Tomato

  9. The Effect of Atrazine on Louisiana Gulf Coast Estuarine Phytoplankton.

    Science.gov (United States)

    Starr, Alexis V; Bargu, Sibel; Maiti, Kanchan; DeLaune, Ronald D

    2017-02-01

    Pesticides may enter water bodies in areas with a high proportion of agricultural land use through surface runoff, groundwater discharge, and erosion and thus negatively impact nontarget aquatic organisms. The herbicide atrazine is used extensively throughout the Midwest and enters the Mississippi River through surface runoff and groundwater discharge. The purpose of this study was to determine the extent of atrazine contamination in Louisiana's estuaries from Mississippi River water under different flow and nutrient regimes (spring and summer) and its effect on the biomass and oxygen production of the local phytoplankton community. The results showed that atrazine was consistently present in these systems at low levels. Microcosm experiments exposed to an atrazine-dilution series under low and high nutrient conditions to determine the phytoplankton stress response showed that high atrazine levels greatly decreased phytoplankton biomass and oxygen production. Phytoplankton exposed to low and moderate atrazine levels under high nutrient conditions were able to recover after an extended acclimation period. Communities grown under high nutrient conditions grew more rapidly and produced greater levels of oxygen than the low nutrient treatment groups, thus indicating that atrazine exposure may induce a greater stress response in phytoplankton communities under low-nutrient conditions. The native community also experienced a shift from more sensitive species, such as chlorophytes, to potentially more resilient species such as diatoms. The phytoplankton response to atrazine exposure at various concentrations can be especially important to greater trophic levels because their growth and abundance can determine the potential productivity of the entire ecosystem.

  10. Genotoxic Effect of Atrazine, Arsenic, Cadmium and Nitrate ...

    African Journals Online (AJOL)

    and human studies have suggested that Atrazine is a carcinogen and an endocrine disruptor with the ability to interfere with reproduction and development (Sass and Colangelo, 2006). In addition, several studies have reported that Atrazine at agricultural concentrations can induce genotoxicity in plants (Plewa et al., 1984).

  11. Reduced dosages of atrazine and narrow rows can provide ...

    African Journals Online (AJOL)

    An on-farm experiment was conducted in Zanyokwe irrigation scheme to investigate the effects of row spacing (45 and 90 cm) and atrazine dosage (33, 67 and 100% of the label recommended dosage) on weed density and biomass and on maize yield. Overall percent kill of weeds increased with increase in atrazine ...

  12. The effects of the herbicide atrazine on freshwater snails.

    Science.gov (United States)

    Gustafson, Kyle D; Belden, Jason B; Bolek, Matthew G

    2015-07-01

    Atrazine has been shown to affect freshwater snails from the subcellular to community level. However, most studies have used different snail species, methods, endpoints, and atrazine exposure concentrations, resulting in some conflicting results and limiting our understanding. The goal of this study was to address these concerns by (1) investigating the acute and chronic effects of atrazine on four species of freshwater snails (Biomphalaria glabrata, Helisoma trivolvis, Physa acuta, and Stagnicola elodes) using the same methods, endpoints, and concentrations, and (2) summarizing the current literature pertaining to the effects of atrazine on freshwater snails. We conducted a 48 h acute toxicity test with an atrazine concentration higher than what typically occurs in aquatic environments (1000 µg/L). Additionally, we exposed snails to environmentally relevant atrazine concentrations (0, 0.3, 3, and 30 µg/L) for 28 days and assessed snail survival, growth, and reproduction. We also summarized all known literature pertaining to atrazine effects on freshwater snails. The literature summary suggests snails are often affected by environmentally relevant atrazine concentrations at the subcellular and cellular levels. These effects are typically not transitive to effects on survival, growth, or reproduction at the same concentrations. Our acute exposures corroborate the general trend of no direct effect on snail populations as atrazine did not directly affect the survival of any of the four snail species. Similarly, environmentally relevant concentrations did not significantly affect the survival, growth, or reproduction of any snail species. These results indicate that, in the absence of other possible stressors, the direct effects of environmentally relevant atrazine concentrations may not be realized at the snail population level.

  13. atz gene expressions during atrazine degradation in the soil drilosphere.

    Science.gov (United States)

    Monard, C; Martin-Laurent, F; Devers-Lamrani, M; Lima, O; Vandenkoornhuyse, P; Binet, F

    2010-02-01

    One of the various ecosystemic services sustained by soil is pollutant degradation mediated by adapted soil bacteria. The pathways of atrazine biodegradation have been elucidated but in situ expression of the genes involved in atrazine degradation has yet to be demonstrated in soil. Expression of the atzA and atzD genes involved in atrazine dechlorination and s-triazine ring cleavage, respectively, was investigated during in situ degradation of atrazine in the soil drilosphere and bulked samples from two agricultural soils that differed in their ability to mineralize atrazine. Interestingly, expression of the atzA gene, although present in both soils, was not detected. Atrazine mineralization was greatest in Epoisses soil, where a larger pool of atzD mRNA was consistently measured 7 days after atrazine treatment, compared with Vezin soil (146 vs. 49 mRNA per 10(6)16S rRNA, respectively). Expression of the atzD gene varied along the degradation time course and was profoundly modified in soil bioturbated by earthworms. The atzD mRNA pool was the highest in the soil drilosphere (casts and burrow-linings) and it was significantly different in burrow-linings compared with bulk soil (e.g. 363 vs. 146 mRNA per 10(6)16S rRNA, 7 days after atrazine treatment in Epoisses soil). Thus, consistent differences in atrazine mineralization were demonstrated between the soil drilosphere and bulk soil. However, the impact of bioturbation on atrazine mineralization depended on soil type. Mineralization was enhanced in casts, compared with bulk soil, from Epoisses soil but in burrow-linings from Vezin soil. This study is the first to report the effects of soil bioturbation by earthworms on s-triazine ring cleavage and its spatial variability in soil.

  14. Biomimicry 1: PC.

    Science.gov (United States)

    Cumberland, D C; Gunn, J; Malik, N; Holt, C M

    1998-01-01

    The surface properties of stents can be modified by coating them, for example with a polymer. Phosphorylcoline (PC) is the major component of the outer layer of the cell membrane. The haemo- and biocompatibility of a PC-containing polymer is thus based on biomimicry, and has been confirmed by several experiments showing much reduced thrombogenicity of PC-coated surfaces, and porcine coronary artery implants showing no sign of adverse effect. Clinical experience with the PC-coated BiodivYsio appears favourable. The PC coating can be tailored for take up and controlled elution of various drugs for stent-based local delivery, a property which is being actively explored.

  15. Annual county atrazine use estimates for agriculture, 1992-2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains annual county-level estimates of total atrazine use on 16 agricultural crops and four agricultural land uses between 1992 and 2007. For each...

  16. Genotoxic Effect of Atrazine, Arsenic, Cadmium and Nitrate ...

    African Journals Online (AJOL)

    ATZ), Cadmium (Cd), Arsenic (As) and Nitrate (NO3) have both estrogenic activity and carcinogenic potential. Atrazine has clastogenic effects and may also act as tumor promoter as it induces the aromatase enzyme. Arsenic and Cadmium ...

  17. Atrazine exposure elicits copy number alterations in the zebrafish genome.

    Science.gov (United States)

    Wirbisky, Sara E; Freeman, Jennifer L

    2017-04-01

    Atrazine is an agricultural herbicide used throughout the Midwestern United States that frequently contaminates potable water supplies resulting in human exposure. Using the zebrafish model system, an embryonic atrazine exposure was previously reported to decrease spawning rates with an increase in progesterone and ovarian follicular atresia in adult females. In addition, alterations in genes associated with distinct molecular pathways of the endocrine system were observed in brain and gonad tissue of the adult females and males. Current hypotheses for mechanistic changes in the developmental origins of health and disease include genetic (e.g., copy number alterations) or epigenetic (e.g., DNA methylation) mechanisms. As such, in the current study we investigated whether an atrazine exposure would generate copy number alterations (CNAs) in the zebrafish genome. A zebrafish fibroblast cell line was used to limit detection to CNAs caused by the chemical exposure. First, cells were exposed to a range of atrazine concentrations and a crystal violet assay was completed, showing confluency decreased by ~60% at 46.3μM. Cells were then exposed to 0, 0.463, 4.63, or 46.3μM atrazine and array comparative genomic hybridization completed. Results showed 34, 21, and 44 CNAs in the 0.463, 4.63, and 46.3μM treatments, respectively. Furthermore, CNAs were associated with previously reported gene expression alterations in adult male and female zebrafish. This study demonstrates that atrazine exposure can generate CNAs that are linked to gene expression alterations observed in adult zebrafish exposed to atrazine during embryogenesis providing a mechanism of the developmental origins of atrazine endocrine disruption. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. A PC based thin film dosimeter system

    DEFF Research Database (Denmark)

    Miller, A.; Hargittai, P.; Kovacs, A.

    2000-01-01

    A dosimeter system based on the Riso B3 dosimeter film, an office scanner for use with PC and the associated software is presented. The scanned image is analyzed either with standard software (Paint Shop Pro 5 or Excel) functions or with the computer code "Scanalizer" that allows presentation...

  19. The PC graphics handbook

    CERN Document Server

    Sanchez, Julio

    2003-01-01

    Part I - Graphics Fundamentals PC GRAPHICS OVERVIEW History and Evolution Short History of PC Video PS/2 Video Systems SuperVGA Graphics Coprocessors and Accelerators Graphics Applications State-of-the-Art in PC Graphics 3D Application Programming Interfaces POLYGONAL MODELING Vector and Raster Data Coordinate Systems Modeling with Polygons IMAGE TRANSFORMATIONS Matrix-based Representations Matrix Arithmetic 3D Transformations PROGRAMMING MATRIX TRANSFORMATIONS Numeric Data in Matrix Form Array Processing PROJECTIONS AND RENDERING Perspective The Rendering Pipeline LIGHTING AND SHADING Lightin

  20. Retention and runoff losses of atrazine and metribuzin in soil.

    Science.gov (United States)

    Selim, H M

    2003-01-01

    Minimizing herbicide runoff and mobility in the soil and thus potential contamination of water resources is a national concern. Metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] and atrazine [2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine] dynamics in surface soils and in runoff waters were studied on six 0.2-ha sugarcane (Saccharum spp.) plots of a Commerce silt loam (fine-silty, mixed, superactive, nonacid, thermic Fluvaquentic Endoaquept) during three growing seasons under different best management practices. Metribuzin was applied in the spring as a postemergence herbicide and atrazine was applied following winter harvest. Both herbicides were applied on top of the sugarcane rows as 0.6- or 0.9-m band width application, or broadcast application, where the entire area was treated. Maximum effluent concentrations were measured from the broadcast treatment and ranged from 600 to 1100 microg L(-1) for atrazine and 250 to 450 microg L(-1) for metribuzin. Atrazine runoff losses were highest for the broadcast treatment (2.8-11% of that applied) and lowest for the 0.6-m band treatment (1.9-7.6%), with a similar trend for metribuzin losses. Measured extractable herbicides from the surface soil exhibited a sharp decrease with time and were well described with a simple first-order decay model. For atrazine, estimates for the decay rate (lambda) were higher than for metribuzin. Results based on laboratory adsorption-desorption (kinetic-batch) measurements were consistent with field observations. The distribution coefficients (Kd) for atrazine exhibited stronger retention over time in comparison with metribuzin on the Commerce soil. Moreover, discrepancies between adsorption isotherm and desorption indicated slower release and that hysteresis was more pronounced for atrazine compared with metribuzin.

  1. Toxicity and physical properties of atrazine and its degradation products: A literature survey

    Energy Technology Data Exchange (ETDEWEB)

    Pugh, K.C.

    1994-10-01

    The Tennessee Valley Authority`s Environmental Research Center has been developing a means of detoxifying atrazine waste waters using TiO{sub 2} photocatalysis. The toxicity and physical properties of atrazine and its degradation products will probably be required information in obtaining permits from the United States Environmental Protection Agency for the demonstration of any photocatalytic treatment of atrazine waste waters. The following report is a literature survey of the toxicological and physical properties of atrazine and its degradation products.

  2. Leo II PC

    Data.gov (United States)

    Kansas Data Access and Support Center — LEO II is a second-generation software system developed for use on the PC, which is designed to convert location references accurately between legal descriptions and...

  3. Phytotoxicity of atrazine, s-metolachlor and permethrin to Typha latifolia (Linneaus) germination and seedling growth

    Science.gov (United States)

    Phytotoxicity assessments were performed to compare responses of Typha latifolia (L.) seeds to atrazine (only) and atrazine + S-metolachlor exposure concentrations of 0.03, 0.3, 3, and 30 mg L-1, as well as permethrin exposure concentrations of 0.008, 0.08, 0.8, and 8 mg L-1. All atrazine + S-metol...

  4. Atrazine-resistant cytoplasmic male-sterile-nigra broccoli obtained by protoplast fusion between cytoplasmic male-sterile Brassica oleracea and atrazine-resistant Brassica campestris.

    Science.gov (United States)

    Christey, M C; Makaroff, C A; Earle, E D

    1991-12-01

    Protoplast fusion was used to combine the cytoplasmic traits of atrazine resistance and male sterility in Brassica oleracea var. italica (broccoli). Leaf protoplasts from broccoli with the petaloid B. nigra type of cytoplasmic male sterility were fused with hypocotyl protoplasts from an atrazine-resistant biotype of B. campestris var. oleifera cv Candle (oilseed rape). A total of 19 colonies regenerated shoots, all of which were broccolilike in phenotype, i.e., lacked trichomes. Four shoots, all from one colony, were atrazine resistant, surviving and growing in the presence of 25 μM atrazine. A leaf piece assay also confirmed that they were atrazine resistant. Molecular analysis showed that they contain chloroplasts from the atrazine-resistant B. campestris parent and mitochondria from the B. nigra parent. No recombination or rearrangement of the mitochondrial genomes in the fusion products was detected. These four plants and their progeny all showed the petaloid B. nigra type of male sterility.

  5. Evaluation of the capacity of the cyanobacterium Microcystis novacekii to remove atrazine from a culture medium.

    Science.gov (United States)

    Campos, Marcela M C; Faria, Vanessa H F; Teodoro, Taciane S; Barbosa, Francisco A R; Magalhães, Sérgia M S

    2013-01-01

    The bioaccumulation of atrazine and its toxicity were evaluated for the cyanobacterium Microcystis novacekii. Cyanobacterial cultures were grown in WC culture medium with atrazine at 50, 250 and 500 μg L(-1). After 96 hours of exposure, 27.2% of the atrazine had been removed from the culture supernatant. Spontaneous degradation was found to be insignificant (remove atrazine combined with its tolerance of the pesticide toxicity showed in this study makes it a potential biological resource for the restoration of contaminated surface waters. These findings support continued studies of the role of M. novacekii in the bioremediation of fresh water environments polluted by atrazine.

  6. Chemical modification and degradation of atrazine in Medicago sativa through multiple pathways.

    Science.gov (United States)

    Zhang, Jing Jing; Lu, Yi Chen; Yang, Hong

    2014-10-08

    Atrazine is a member of the triazine herbicide family intensively used to control weeds for crop production. In this study, atrazine residues and its degraded products in alfalfa (Medicago sativa) were characterized using UPLC-TOF-MS/MS. Most of atrazine absorbed in plants was found as chemically modified derivatives like deisopropylated atrazine (DIA), dehydrogenated atrazine (DHA), or methylated atrazine (MEA), and some atrazine derivatives were conjugated through different functional groups such as sugar, glutathione, and amino acids. Interestingly, the specific conjugates DHA+hGSH (homoglutathione) and MEA-HCl+hGSH in alfalfa were detected. These results suggest that atrazine in alfalfa can be degraded through different pathways. The increased activities of glycosyltransferase and glutathione S-transferase were determined to support the atrazine degradation models. The outcome of the work uncovered the detailed mechanism for the residual atrazine accumulation and degradation in alfalfa and will help to evaluate whether the crop is suitable to be cultivated in the atrazine-polluted soil.

  7. Building the perfect PC

    CERN Document Server

    Thompson, Robert Bruce

    2006-01-01

    This popular Build-It-Yourself (BIY) PC book covers everything you want to know about building your own system: Planning and picking out the right components, step-by-step instructions for assembling your perfect PC, and an insightful discussion of why you'd want to do it in the first place. Most big brand computers from HP, Dell and others use lower-quality components so they can meet their aggressive pricing targets. But component manufacturers also make high-quality parts that you can either purchase directly, or obtain through distributors and resellers. Consumers and corporations

  8. Beware the PC Police.

    Science.gov (United States)

    Cheney, Lynne V.

    1992-01-01

    Decries the prevalence of "racism,""sexual harassment," and "speciesism" labels applied to supposed violators of "political correctness" (PC). When freedom of speech on college campuses is held hostage to political correctness, K-12 education is bound to be affected. This new brand of McCarthyism cheapens…

  9. Bioavailability of organoclay formulations of atrazine in soil

    Science.gov (United States)

    Pesticide formulations based on organoclays have been proposed to prolong the efficacy and reduce the environmental impact of pesticides in soil. This research addressed the question of whether organoclay-based formulations of atrazine are irreversibly sorbed or are bioavailable for bacterial degrad...

  10. Lichen microalgae are sensitive to environmental concentrations of atrazine.

    Science.gov (United States)

    Traba, Helena Moreno; Domínguez-Morueco, Noelia; Barreno, Eva; Catalá, Myriam

    2017-04-03

    The identification of new organisms for environmental toxicology bioassays is currently a priority, since these tools are strongly limited by the ecological relevance of taxa used to study global change. Lichens are sensitive bioindicators of air quality and their microalgae are an untapped source for new low-cost miniaturized bioassays with ecological importance. In order to increase the availability of a wider range of taxa for bioassays, the sensitivity of two symbiotic lichen microalgae, Asterochloris erici and Trebouxia sp. TR9, to atrazine was evaluated. To achieve this goal, axenic cultures of these phycobionts in suspension were exposed to a range of environmental concentrations of the herbicide atrazine, a common water pollutant. Optical density and chlorophyll autofluorescence were used as endpoints of ecotoxicity and ecophysiology on cell suspensions. Results show that lichen microalgae show high sensitivity to very low doses of atrazine, being higher in Asterochloris erici than in Trebouxia sp. TR9. We conclude that environmental concentrations of atrazine could modify population dynamics probably through a shift in reproduction strategies of these organisms. This seminal work is a breakthrough in the use of lichen microalgae in the assessment of micropollution effects on biodiversity.

  11. Effect of atrazine (Herbicide) on blood parameters of common carp ...

    African Journals Online (AJOL)

    EJIRO

    could be used as an important tool for the assessment of pathological conditions of fish. Key words: Atrazine, acute toxicity, hematology, biochemical, Cyprinus carpio. INTRODUCTION. Due to rapid industrialization, application of synthetic fertilizers and use of various insecticides and pesticides, the natural water resources ...

  12. Effect of oral administration of sublethal concentration of atrazine on ...

    African Journals Online (AJOL)

    ... (p<0.05) total WBC counts all through the study, and group IV rats had significantly higher (p<0.05) lymphocytes and significantly lower (p<0.05) neutrophil on day 28 when compared with the control. Keywords: Albino rat, Rattus norvegicus, Atrazine, Haematology Animal Research International(2012) 9(2): 1572 – 1578 ...

  13. Postplanting sprays of dalapon and atrazine to aid conifer establishment.

    Science.gov (United States)

    Edward J. Dimock; Ernest B. Collard

    1981-01-01

    A mixture of dalapon and atrazine consistently controlled grasses of forbs better than either herbicide used alone. Sprayed over and around newly planted ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco), the mixture doubled tree survival...

  14. Polyelectrolytes Ability in Reducing Atrazine Concentration in Water : Surface Effects

    NARCIS (Netherlands)

    Mohd Amin, M.F.; Heijman, S.G.J.; Lopes, S.I.C.; Rietveld, L.C.

    2014-01-01

    This paper reports on the direct ability of two positively charged organic polyelectrolytes (natural-based and synthetic) to reduce the atrazine concentration in water. The adsorption study was set up using multiple glass vessels with different polymer dosing levels followed by ultrafiltration with

  15. Toxicity of three selected pesticides (Alachlor, Atrazine and Diuron ...

    African Journals Online (AJOL)

    The present study aimed to evaluate acute toxicity tests for three selected herbicides: Alachlor, Atrazine and Diuron using turbot flatfish. Larvae were more sensitive than turbot embryos to all pesticides. Median lethal concentrations of the selected pesticides during a 48 h and 96 h exposure for turbot embryos and larvae ...

  16. Dairy-manure derived biochar effectively sorbs lead and atrazine.

    Science.gov (United States)

    Cao, Xinde; Ma, Lena; Gao, Bin; Harris, Willie

    2009-05-01

    Biochar (BC) produced from agricultural crop residues has proven effective in sorbing organic contaminants. This study evaluated the ability of dairy-manure derived biochar to sorb heavy metal Pb and organic contaminant atrazine. Two biochar samples were prepared by heating dairy manure at low temperature of 200 degrees C (BC200) and 350 degrees C (BC350). The untreated manure (BC25) and a commercial activated C (AC) were included as controls. Sorption of Pb by biochar followed a dual Langmuir-Langmuir model, attributing to Pb precipitation (84-87%) and surface sorption (13-16%). Chemical speciation, X-ray diffraction, and infrared spectroscopy indicated that Pb was precipitated as beta-Pb9(PO4)6 in BC25 and BC200 treatment, and as Pb3(CO3)2(OH)2 in BC350. Lead sorption by AC obeyed a single Langmuir model, attributing mainly to surface sorption probably via coordination of Pb d-electron to C==C (pi-electron) and --0--Pb bonds. The biochar was 6 times more effective in Pb sorption than AC, with BC200 being the most effective (up to 680 mmol Pb kg(-1)). The biochar also effectively sorbed atrazine where atrazine was partitioned into its organic phase, whereas atrazine uptake by AC occurred via surface sorption. When Pb and atrazine coexisted, little competition occurred between the two for sorption on biochar, while strong competition was observed on AC. Results from this study indicated that dairy manure can be converted into value-added biochar as effective sorbent for metal and/or organic contaminants.

  17. Toxicity of atrazine and its bioaccumulation and biodegradation in a green microalga, Chlamydomonas mexicana.

    Science.gov (United States)

    Kabra, Akhil N; Ji, Min-Kyu; Choi, Jaewon; Kim, Jung Rae; Govindwar, Sanjay P; Jeon, Byong-Hun

    2014-11-01

    This study evaluated the toxicity of herbicide atrazine, along with its bioaccumulation and biodegradation in the green microalga Chlamydomonas mexicana. At low concentration (10 μg L(-1)), atrazine had no profound effect on the microalga, while higher concentrations (25, 50, and 100 μg L(-1)) imposed toxicity, leading to inhibition of cell growth and chlorophyll a accumulation by 22 %, 33 %, and 36 %, and 13 %, 24 %, and 27 %, respectively. Atrazine 96-h EC50 for C. mexicana was estimated to be 33 μg L(-1). Microalga showed a capability to accumulate atrazine in the cell and to biodegrade the cell-accumulated atrazine resulting in 14-36 % atrazine degradation at 10-100 μg L(-1). Increasing atrazine concentration decreased the total fatty acids (from 102 to 75 mg g(-1)) and increased the unsaturated fatty acid content in the microalga. Carbohydrate content increased gradually with the increase in atrazine concentration up to 15 %. This study shows that C. mexicana has the capability to degrade atrazine and can be employed for the remediation of atrazine-contaminated streams.

  18. Alginate immobilized enrichment culture for atrazine degradation in soil and water system.

    Science.gov (United States)

    Kumar, Anup; Nain, Lata; Singh, Neera

    2017-04-03

    An atrazine degrading enrichment culture, a consortium of bacteria of genus Bacillus along with Pseudomonas and Burkholderia, was immobilized in sodium alginate and was used to study atrazine degradation in mineral salts medium (MSM), soil and wastewater effluent. Sodium alginate immobilized consortium, when stored at room temperature (24 ± 5°C), was effective in degrading atrazine in MSM up to 90 days of storage. The survival of bacteria in alginate beads, based on colony formation unit (CFU) counts, suggested survival up to 90 days and population counts decreased to 1/5 th on 120 days. Comparison of atrazine degrading ability of the freely suspended enrichment culture and immobilized culture suggested that the immobilized culture took longer time for complete degradation of atrazine as a lag phase of 2 days was observed in the MSM inoculated with alginate immobilized culture. The free cells resulted in complete degradation of atrazine within 6 days, while immobilized cells took 10 days for 100% atrazine degradation. Further, immobilized cultures were able to degrade atrazine in soil and wastewater effluent. Alginate beads were stable and effective in degrading atrazine till 3rd transfer and disintegrated thereafter. The study suggested that immobilized enrichment culture, due to its better storage and application, can be used to degrade atrazine in soil water system.

  19. Relationship between uptake capacity and differential toxicity of the herbicide atrazine in selected microalgal species

    Energy Technology Data Exchange (ETDEWEB)

    Weiner, Jeannette A.; DeLorenzo, Marie E.; Fulton, Michael H

    2004-06-10

    Microalgal species vary in their sensitivity to the triazine herbicide, atrazine. This study examined both atrazine uptake and cellular characteristics of microalgae to determine if either can be used to predict algal sensitivity. Standard toxicity tests were performed on five microalgal species, each representing a different algal division or habitat. Test species listed in order of increasing sensitivity were: Isochrysis galbana, Dunaliella tertiolecta, Phaeodactylum tricornutum, Pseudokirchneriella subcapitata, and Synechococcus sp. Each species was exposed to {sup 14}C-atrazine at its growth rate EC{sub 50} concentration (44-91 {mu}g/L). At five time-points over 96 h, samples were filtered to collect algae and washed with unlabeled atrazine to displace labeled atrazine loosely absorbed to the cell surface. Radioactivity present on filters and in the growth medium was measured by liquid scintillation counting. Relationships between algal species-sensitivity to atrazine and compound uptake, cell dry weight, cell volume, and cell surface area were determined by linear regression analysis. Cell size measurements (based on dry weight, biovolume, and surface area) were significantly correlated with atrazine uptake (R{sup 2}>0.45, P-value < 0.05). There was a significant correlation between atrazine uptake and species-sensitivity to atrazine (R{sup 2}=0.5413, P-value = 0.0012). These results indicate that smaller cells with greater surface area to volume ratios will incorporate more atrazine, and in general, will be more sensitive to atrazine exposure. However, I. galbana, with small cell size and relatively high atrazine uptake was the least sensitive species tested. This species and others may have mechanisms to compensate for atrazine stress that make predicting responses of microalgal communities difficult.

  20. Evaluation of the side effects of poly(epsilon-caprolactone) nanocapsules containing atrazine towards maize plants

    Science.gov (United States)

    Oliveira, Halley; Stolf-Moreira, Renata; Martinez, Cláudia; Sousa, Gustavo; Grillo, Renato; de Jesus, Marcelo; Fraceto, Leonardo

    2015-10-01

    Poly(epsilon-caprolactone) (PCL) nanocapsules have been used as a carrier system for the herbicide atrazine, which is commonly applied to maize. We demonstrated previously that these atrazine containing polymeric nanocapsules were ten-fold more effective in the control of mustard plants (a target species), as compared to a commercial atrazine formulation. Since atrazine can have adverse effects on non-target crops, here we analyzed the effect of encapsulated atrazine on growth, physiological and oxidative stress parameters of soil-grown maize plants (Zea mays L.). One day after the post-emergence treatment with PCL nanocapsules containing atrazine (1 mg mL-1), maize plants presented 15 and 21 % decreases in maximum quantum yield of photosystem II and in net CO2 assimilation rate, respectively, as compared to water-sprayed plants. The same treatment led to a 1.8-fold increase in leaf lipid peroxidation in comparison with control plants. However, all of these parameters were unaffected four and eight days after the application of encapsulated atrazine. These results suggested that the negative effects of atrazine were transient, probably due to the ability of maize plants to detoxify the herbicide. When encapsulated atrazine was applied at a ten-fold lower concentration (0.1 mg mL-1), a dosage that is still effective for weed control, no effects were detected even shortly after application. Regardless of the herbicide concentration, neither pre- nor post-emergence treatment with the PCL nanocapsules carrying atrazine resulted in the development of any macroscopic symptoms in maize leaves, and there were no impacts on shoot growth. Additionally, no effects were observed when plants were sprayed with PCL nanocapsules without atrazine. Overall, these results suggested that the use of PCL nanocapsules containing atrazine did not lead to persistent side effects in maize plants, and that the technique could offer a safe tool for weed control without affecting crop growth.

  1. Evaluation of the side effects of poly(epsilon-caprolactone nanocapsules containing atrazine towards maize plants

    Directory of Open Access Journals (Sweden)

    Halley Caixeta Oliveira

    2015-10-01

    Full Text Available Poly(epsilon-caprolactone (PCL nanocapsules have been used as a carrier system for the herbicide atrazine, which is commonly applied to maize. We demonstrated previously that these atrazine containing polymeric nanocapsules were ten-fold more effective in the control of mustard plants (a target species, as compared to a commercial atrazine formulation. Since atrazine can have adverse effects on non-target crops, here we analyzed the effect of encapsulated atrazine on growth, physiological and oxidative stress parameters of soil-grown maize plants (Zea mays L.. One day after the post-emergence treatment with PCL nanocapsules containing atrazine (1 mg mL-1, maize plants presented 15 and 21 % decreases in maximum quantum yield of photosystem II and in net CO2 assimilation rate, respectively, as compared to water-sprayed plants. The same treatment led to a 1.8-fold increase in leaf lipid peroxidation in comparison with control plants. However, all of these parameters were unaffected four and eight days after the application of encapsulated atrazine. These results suggested that the negative effects of atrazine were transient, probably due to the ability of maize plants to detoxify the herbicide. When encapsulated atrazine was applied at a ten-fold lower concentration (0.1 mg mL-1, a dosage that is still effective for weed control, no effects were detected even shortly after application. Regardless of the herbicide concentration, neither pre- nor post-emergence treatment with the PCL nanocapsules carrying atrazine resulted in the development of any macroscopic symptoms in maize leaves, and there were no impacts on shoot growth. Additionally, no effects were observed when plants were sprayed with PCL nanocapsules without atrazine. Overall, these results suggested that the use of PCL nanocapsules containing atrazine did not lead to persistent side effects in maize plants, and that the technique could offer a safe tool for weed control without affecting

  2. Isolation and characterization of atrazine mineralizing Bacillus subtilis strain HB-6.

    Directory of Open Access Journals (Sweden)

    Jinhua Wang

    Full Text Available Atrazine is a widely used herbicide with great environmental concern due to its high potential to contaminate soil and waters. An atrazine-degrading bacterial strain HB-6 was isolated from industrial wastewater and the 16S rRNA gene sequencing identified HB-6 as a Bacillus subtilis. PCR assays indicated that HB-6 contained atrazine-degrading genes trzN, atzB and atzC. The strain HB-6 was capable of utilizing atrazine and cyanuric acid as a sole nitrogen source for growth and even cleaved the s-triazine ring and mineralized atrazine. The strain demonstrated a very high efficiency of atrazine biodegradation with a broad optimum pH and temperature ranges and could be enhanced by cooperating with other bacteria, suggesting its huge potential for remediation of atrazine-contaminated sites. To our knowledge, there are few Bacillus subtilis strains reported that can mineralize atrazine, therefore, the present work might provide some new insights on atrazine remediation.

  3. Phytoremediation potential of the novel atrazine tolerant Lolium multiflorum and studies on the mechanisms involved

    Energy Technology Data Exchange (ETDEWEB)

    Merini, Luciano J. [Catedra de Microbiologia Industrial y Biotecnologia, Universidad de Buenos Aires (Argentina); Bobillo, Cecilia [Servicio de Huellas Digitales Geneticas, Facultad de Farmacia y Bioquimica, Microbiologia Industrial y Biotecnologia, Universidad de Buenos Aires, Junin 956, BS As (Argentina); Cuadrado, Virginia [Catedra de Microbiologia Industrial y Biotecnologia, Universidad de Buenos Aires (Argentina); Corach, Daniel [Servicio de Huellas Digitales Geneticas, Facultad de Farmacia y Bioquimica, Microbiologia Industrial y Biotecnologia, Universidad de Buenos Aires, Junin 956, BS As (Argentina); Giulietti, Ana M., E-mail: agiule@ffyb.uba.a [Catedra de Microbiologia Industrial y Biotecnologia, Universidad de Buenos Aires (Argentina)

    2009-11-15

    Atrazine impact on human health and the environment have been extensively studied. Phytoremediation emerged as a low cost, environmental friendly biotechnological solution for atrazine pollution in soil and water. In vitro atrazine tolerance assays were performed and Lolium multiflorum was found as a novel tolerant species, able to germinate and grow in the presence of 1 mg kg{sup -1} of the herbicide. L. multiflorum presented 20% higher atrazine removal capacity than the natural attenuation, with high initial degradation rate in microcosms. The mechanisms involved in atrazine tolerance such as mutation in psbA gene, enzymatic detoxification via P{sub 450} or chemical hydrolysis through benzoxazinones were evaluated. It was demonstrated that atrazine tolerance is conferred by enhanced enzymatic detoxification via P{sub 450}. Due to its atrazine degradation capacity in soil and its agronomical properties, L. multiflorum is a candidate for designing phytoremediation strategies for atrazine contaminated agricultural soils, especially those involving run-off avoiding. - Finding of a novel atrazine-tolerant species, as a potential candidate for phytoremediating herbicide-contaminated agriculture soils and elucidation of the mechanisms involved in tolerance.

  4. FATE OF ATRAZINE IN THE AGRICULTURAL SOIL OF CORN FIELDS IN FARS PROVINCE OF IRAN

    Directory of Open Access Journals (Sweden)

    S. Nasseri ، M. Dehghani ، S. Amin ، K. Naddafi ، Z. Zamanian

    2009-10-01

    Full Text Available Atrazine, a herbicide widely used in corn production, is frequently detected as pesticide in water resources. In this research, four agricultural fields with a long history of atrazine application in Shiraz and its vicinity in Fars province of Iran, have been studied to determine the fate of atrazine through the passage of time. These four farms were cultivated under a crop rotation (corn-wheat during the past 10 years. Samples were collected from four soil profiles of 0-10, 10-20, 20-40, and 40-60 cm soil depth at different times. The time intervals for soil sampling started before atrazine application and continued until no atrazine was detected. According to the general linear model, there was no significant difference between atrazine residual concentrations and the soil moisture and depth (p≥0.05. But, significant difference between atrazine residual concentrations and the sampling regions was observed (p<0.001. Based on the data, atrazine leaching and dissipation rate in different soil profiles in the four sampling regions were high and significant. Therefore, there is a high risk of atrazine pollution in groundwater resources of the region.

  5. Atrazine and glyphosate dynamics in a lotic ecosystem: the common snapping turtle as a sentinel species.

    Science.gov (United States)

    Douros, Derrick L; Gaines, Karen F; Novak, James M

    2015-03-01

    Atrazine and glyphosate are two of the most common pesticides used in the US Midwest that impact water quality via runoff, and the common snapping turtle (Chelydra serpentina) is an excellent indicator species to monitor these pesticides especially in lotic systems. The goals of this study were to (1) quantify atrazine, the atrazine metabolite diaminochlorotriazine (DACT), and glyphosate burdens in common snapping turtle tissue from individuals collected within the Embarras River in Illinois; (2) quantify atrazine, DACT, and glyphosate loads in water from the aquatic habitats in which common snapping turtles reside; and (3) investigate tissue loads based on turtle morphology and habitat choice. Concentrations of atrazine, DACT, and glyphosate in tissue did not show any relationship with lake habitat, carapace length, width, or mass. Both atrazine and glyphosate tissue samples varied as a function of site (river vs. lake), but DACT did not. Atrazine and glyphosate concentrations in water samples showed a linear effect on distance from the reservoir spillway and a deviation from linearity. Water column concentrations of all three contaminants varied across capture sites, but atrazine water concentration did not influence DACT water concentration nor did it exhibit a site interaction. Water atrazine and glyphosate concentrations were greater than tissue concentrations, whereas DACT water and tissue concentrations did not differ. This study showed that turtles are useful in long-term pesticide monitoring, and because DACT as a metabolite is less sensitive to variation, it should be considered as a preferred biomarker for pesticide runoff.

  6. A PC Controlled Filter

    Directory of Open Access Journals (Sweden)

    M. Van Looy

    1998-12-01

    Full Text Available In this paper we present a switched capacitor filter design using the SC22324 1C, which is fitted with an E2PROM. It contains four digitally programmable switched-capacitor filter sections, in order to obtain different responses. The SC22324 also contains the on-chip RAM. We'd like to explain, how could the on-chip RAM controlled via a PC. In this way the chip may be used afterwards with a menu where the user may select the wanted parameters.

  7. Polyelectrolytes Ability in Reducing Atrazine Concentration in Water: Surface Effects

    Directory of Open Access Journals (Sweden)

    Mohamad Faiz Mohd Amin

    2014-01-01

    Full Text Available This paper reports on the direct ability of two positively charged organic polyelectrolytes (natural-based and synthetic to reduce the atrazine concentration in water. The adsorption study was set up using multiple glass vessels with different polymer dosing levels followed by ultrafiltration with a 1 kDa membrane. The addition of polymers exhibited a capability in reducing the atrazine concentration up to a maximum of 60% in surface-to-volume ratio experiments. In the beginning, the theoretical L-type of the isotherm of Giles’ classification was expected with an increase in the dosage of the polymer. However, in this study, the conventional type of isotherm was not observed. It was found that the adsorption of the cationic polymer on the negatively charged glass surface was necessary and influential for the removal of atrazine. Surface-to-volume ratio adsorption experiments were performed to elucidate the mechanisms and the polymer configuration. The glass surface area was determined to be a limiting parameter in the adsorption mechanism.

  8. Atrazine contamination in agricultural soils from the Yangtze River Delta of China and associated health risks.

    Science.gov (United States)

    Sun, J T; Pan, L L; Zhan, Yu; Tsang, Daniel C W; Zhu, L Z; Li, X D

    2017-04-01

    Atrazine is one of the most widely applied and persistent herbicides in the world. In view of limited information on the regional contamination of atrazine in soils in China, this study investigated the spatial distribution and environmental impacts of atrazine in agricultural soils collected from the Yangtze River Delta (YRD) as an illustrative analysis of rapidly developing regions in the country. The results showed that the concentrations of atrazine in the YRD agricultural soils ranged from <1.0 to 113 ng/g dry weight, with a mean of 5.7 ng/g, and a detection rate of 57.7 % in soils. Pesticide factory might be a major source for the elevated levels of atrazine in Zhejiang Province. The contamination of atrazine was closely associated with land use types. The concentrations and detection rates of atrazine were higher in corn fields and mulberry fields than in rice paddy fields. There was no significant difference in compositions of soil microbial phospholipids fatty acids among the areas with different atrazine levels. Positive relationship (R = 0.417, p < 0.05, n = 30) was observed between atrazine and total microbial biomass. However, other factors, such as soil type and land management practice, might have stronger influences on soil microbial communities. Human health risks via exposure to atrazine in soils were estimated according to the methods recommended by the US EPA. Atrazine by itself in all the soil samples imposed very low carcinogenic risks (<10-6) and minimal non-cancer risks (hazard index <1) to adults and children.

  9. Repairing and Upgrading Your PC

    CERN Document Server

    Thompson, Robert

    2009-01-01

    Repairing and Upgrading Your PC delivers start-to-finish instructions, simple enough for even the most inexperienced PC owner, for troubleshooting, repairing, and upgrading your computer. Written by hardware experts Robert Bruce Thompson and Barbara Fritchman Thompson, this book covers it all: how to troubleshoot a troublesome PC, how to identify which components make sense for an upgrade, and how to tear it all down and put it back together. This book shows how to repair and upgrade all of your PC's essential components.

  10. Response of ligninolytic macrofungi to the herbicide atrazine: dose-response bioassays

    Directory of Open Access Journals (Sweden)

    Wilberth Chan Cupul

    2014-12-01

    Full Text Available The effect of atrazine concentrations on mycelial growth and ligninolytic enzyme activities of eight native ligninolytic macrofungi isolated in Veracruz, México, were evaluated in a semi-solid culture medium. Inhibition of mycelial growth and growth rates were significantly affected (p = 0.05 by atrazine concentrations (468, 937, 1875, and 3750 mg/l. In accordance with the median effective concentration (EC50, Pleurotus sp. strain 1 proved to be the most tolerant isolate to atrazine (EC50 = 2281.0 mg/l, although its enzyme activity was not the highest. Pycnoporus sanguineus strain 2, Daedalea elegans and Trametes maxima showed high laccase activity (62.7, 31.9, 29.3 U mg/protein, respectively without atrazine (control; however, this activity significantly increased (p < 0.05 (to 191.1, 83.5 and 120.6 U mg/protein, respectively owing to the effect of atrazine (937 mg/l in the culture medium. Pleurotus sp. strain 2 and Cymatoderma elegans significantly increased (p < 0.05 their manganese peroxidase (MnP activities under atrazine stress at 468 mg/l. The isolates with high EC50 (Pleurotus sp. strain 1 and high enzymatic activity (P. sanguineus strain 2 and T. maxima could be considered for future studies on atrazine mycodegradation. Furthermore, this study confirms that atrazine can increase laccase and MnP activities in ligninolytic macrofungi.

  11. Effect of compost age and composition on the atrazine removal from solution

    Science.gov (United States)

    Tsui, L.; Roy, W.R.

    2007-01-01

    Compost samples from two composting facilities, the Urbana (Illinois) Landscape Recycling Center (ULRC) and Illinois State University (ISU), were selected to examine the effect of compost age on atrazine removal from solution. The ULRC samples were made from yard waste without an additional nitrogen source. The ISU samples were made from yard waste or sawdust with the addition of manure. The 6-month-old ULRC compost had the greater capacity to remove atrazine from solution, which we attributed to its greater organic carbon content. The addition of nitrate into ULRC compost could influence the extent of atrazine removal, but did not have a significant impact on atrazine removal when applied to ISU compost, probably because manure was added to the yard waste to produce the compost. For both ULRC and ISU samples, the presence of sodium azide inhibited atrazine removal, suggesting that microbial activity contributed to the atrazine removal. Metabolic analysis demonstrated that hydroxyatrazine was the major identified metabolite that accumulated in solution before significant ring mineralization could occur. When compared with the ISU compost, the ULRC compost sample had a greater capacity to remove atrazine from solution during the 120 days of study because of the larger humic acid content. The experimental results suggested that less-mature compost may be better suited for environmental applications such as removing atrazine from tile-drainage waters. ?? 2006 Elsevier B.V. All rights reserved.

  12. Atrazine exposure decreases the activity of DNMTs, global DNA methylation levels, and dnmt expression.

    Science.gov (United States)

    Wirbisky-Hershberger, Sara E; Sanchez, Oscar F; Horzmann, Katharine A; Thanki, Devang; Yuan, Chongli; Freeman, Jennifer L

    2017-11-01

    Atrazine, a herbicide used on agricultural crops is widely applied in the Midwestern United States as well as other areas of the globe. Atrazine frequently contaminates potable water supplies and is a suspected endocrine disrupting chemical. Previous studies have reported morphological, hormonal, and molecular alterations due to developmental and adulthood atrazine exposure; however, studies examining epigenetic alterations are limited. In this study, the effects of atrazine exposure on DNA methyltransferase (DNMT) activity and kinetics were evaluated. Global DNA methylation levels and dnmt expression in zebrafish larvae exposed to 0, 3, or 30 parts per billion (ppb) atrazine throughout embryogenesis was then assessed. Results indicate that atrazine significantly decreased the activity of maintenance DNMTs and that the inhibition mechanism can be described using non-competitive Michaelis-Menten kinetics. Furthermore, results show that an embryonic atrazine exposure decreases global methylation levels and the expression of dnmt4 and dnmt5. These findings indicate that atrazine exposure can decrease the expression and activity of DNMTs, leading to decreased DNA methylation levels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Embryo-larval exposure to atrazine reduces viability and alters oxidative stress parameters in Drosophila melanogaster.

    Science.gov (United States)

    Figueira, Fernanda Hernandes; Aguiar, Lais Mattos de; Rosa, Carlos Eduardo da

    2017-01-01

    The herbicide atrazine has been used worldwide with subsequent residual contamination of water and food, which may cause adverse effects on non-target organisms. Animal exposure to this herbicide may affect development, reproduction and energy metabolism. Here, the effects of atrazine regarding survival and redox metabolism were assessed in the fruit fly D. melanogaster exposed during embryonic and larval development. The embryos (newly fertilized eggs) were exposed to different atrazine concentrations (10μM and 100μM) in the diet until the adult fly emerged. Pupation and emergence rates, developmental time and sex ratio were determined as well as oxidative stress parameters and gene expression of the antioxidant defence system were evaluated in newly emerged male and female flies. Atrazine exposure reduced pupation and emergence rates in fruit flies without alterations to developmental time and sex ratio. Different redox imbalance patterns were observed between males and females exposed to atrazine. Atrazine caused an increase in oxidative damage, reactive oxygen species generation and antioxidant capacity and decreased thiol-containing molecules. Further, atrazine exposure altered the mRNA expression of antioxidant genes (keap1, sod, sod2, cat, irc, gss, gclm, gclc, trxt, trxr-1 and trxr-2). Reductions in fruit fly larval and pupal viability observed here are likely consequences of the oxidative stress induced by atrazine exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Effects of Funnelliformis mosseae inoculation on alleviating atrazine damage in Canna indica L. var. flava Roxb.

    Science.gov (United States)

    Dong, Jing; Wang, Li; Ma, Fang; Yang, Jixian; Zhang, Xue; Zhao, Ting; Qi, Shanshan

    2017-01-02

    Atrazine residue in the environment continually damages plants and therefore requires immediate attention and effective development of methods for its decontamination. The effects of Funnelliformis mosseae inoculation on growth and physiology in atrazine-treated Canna indica L. var. flava Roxb. were investigated. At atrazine concentrations up to 15 mg L-1, the growth of C. indica plants were negatively affected. Inoculation with F. mosseae alleviated the atrazine inhibition of plant growth and biomass. Furthermore, the chlorophyll content and root function increased under F. mosseae inoculation, and the oxidative stress of malondialdehyde, peroxidase, and superoxide dismutase activities induced by atrazine were also alleviated by F. mosseae inoculation. The removal rate of atrazine by untreated C. indica was significant, with removal rates of 20.5-55.3% by the end of a 14-day experiment; however, F. mosseae inoculation increased the removal rate to 35.6-75.1%. In conclusion, F. mosseae inoculation can alleviate the damage induced by atrazine in C. indica. Accordingly, C. indica inoculated with F. mosseae has excellent potential to be used in phytoremediation in habitats polluted by high atrazine concentrations.

  15. Atrazine and its metabolites degradation in mineral salts medium and soil using an enrichment culture.

    Science.gov (United States)

    Kumar, Anup; Singh, Neera

    2016-03-01

    An atrazine-degrading enrichment culture was used to study degradation of atrazine metabolites viz. hydroxyatrazine, deethylatrazine, and deisopropylatrazine in mineral salts medium. Results suggested that the enrichment culture was able to degrade only hydroxyatrazine, and it was used as the sole source of carbon and nitrogen. Hydroxyatrazine degradation slowed down when sucrose and/or ammonium hydrogen phosphate were supplemented as the additional sources of carbon and nitrogen, respectively. The enrichment culture could degrade high concentrations of atrazine (up to 110 μg/mL) in mineral salts medium, and neutral pH was optimum for atrazine degradation. Further, except in an acidic soil, enrichment culture was able to degrade atrazine in three soil types having different physico-chemical properties. Raising the pH of acidic soil to neutral or alkaline enabled the enrichment culture to degrade atrazine suggesting that acidic pH inhibited atrazine-degrading ability. The study suggested that the enrichment culture can be successfully utilized to achieve complete degradation of atrazine and its persistent metabolite hydroxyatrazine in the contaminated soil and water.

  16. Adsorption-desorption behavior of atrazine on agricultural soils in China.

    Science.gov (United States)

    Yue, Lin; Ge, ChengJun; Feng, Dan; Yu, Huamei; Deng, Hui; Fu, Bomin

    2017-07-01

    Adsorption and desorption are important processes that affect atrazine transport, transformation, and bioavailability in soils. In this study, the adsorption-desorption characteristics of atrazine in three soils (laterite, paddy soil and alluvial soil) were evaluated using the batch equilibrium method. The results showed that the kinetics of atrazine in soils was completed in two steps: a "fast" adsorption and a "slow" adsorption and could be well described by pseudo-second-order model. In addition, the adsorption equilibrium isotherms were nonlinear and were well fitted by Freundlich and Langmuir models. It was found that the adsorption data on laterite, and paddy soil were better fitted by the Freundlich model; as for alluvial soil, the Langmuir model described it better. The maximum atrazine sorption capacities ranked as follows: paddy soil>alluvial soil>laterite. Results of thermodynamic calculations indicated that atrazine adsorption on three tested soils was spontaneous and endothermic. The desorption data showed that negative hysteresis occurred. Furthermore, lower solution pH value was conducive to the adsorption of atrazine in soils. The atrazine adsorption in these three tested soils was controlled by physical adsorption, including partition and surface adsorption. At lower equilibrium concentration, the atrazine adsorption process in soils was dominated by surface adsorption; while with the increase of equilibrium concentration, partition was predominant. Copyright © 2016. Published by Elsevier B.V.

  17. 76 FR 1990 - Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350...

    Science.gov (United States)

    2011-01-12

    ... PC- 6 Aircraft Maintenance Manual (AMM) Chapter 5 limitations which have included the same repetitive... inspections, in the latest revision of the PC-6 AMM, the replacement procedures for the fittings were included... PC- 6 Aircraft Maintenance Manual (AMM) Chapter 5 limitations which have included the same repetitive...

  18. 75 FR 62005 - Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350...

    Science.gov (United States)

    2010-10-07

    ... PC- 6 Aircraft Maintenance Manual (AMM) Chapter 5 limitations which have included the same repetitive... inspections, in the latest revision of the PC-6 AMM, the replacement procedures for the fittings were included... PC- 6 Aircraft Maintenance Manual (AMM) Chapter 5 limitations which have included the same repetitive...

  19. Atrazine acts as an endocrine disrupter by inhibiting cAMP-specific phosphodiesterase-4

    Energy Technology Data Exchange (ETDEWEB)

    Kucka, Marek [Section on Cellular Signaling, Program in Developmental Neuroscience, NICHD, NIH, Bethesda, MD (United States); Pogrmic-Majkic, Kristina; Fa, Svetlana [Laboratory for Ecotoxicology, Department of Biology and Ecology, University of Novi Sad, Faculty of Sciences, 21000 Novi Sad (Serbia); Stojilkovic, Stanko S. [Section on Cellular Signaling, Program in Developmental Neuroscience, NICHD, NIH, Bethesda, MD (United States); Kovacevic, Radmila, E-mail: radmila.kovacevic@dbe.uns.ac.rs [Laboratory for Ecotoxicology, Department of Biology and Ecology, University of Novi Sad, Faculty of Sciences, 21000 Novi Sad (Serbia)

    2012-11-15

    Atrazine, one of the most commonly used herbicides worldwide, acts as an endocrine disruptor, but the mechanism of its action has not been characterized. In this study, we show that atrazine rapidly increases cAMP levels in cultured rat pituitary and testicular Leydig cells in a concentration-dependent manner, but less effectively than 3-isobutyl-1-methylxanthine, a competitive non-specific inhibitor of phosphodiesterases (PDEs). In forskolin (an activator of adenylyl cyclase)- and probenecid (an inhibitor of cyclic nucleotide transporters)-treated cells, but not in 3-isobutyl-1-methylxanthine-treated cells, atrazine further increased cAMP levels, indicating that inhibition of PDEs accounts for accumulation of cAMP. In contrast to cAMP, atrazine did not alter cGMP levels, further indicating that it inhibits cAMP-specific PDEs. Atrazine-induced changes in cAMP levels were sufficient to stimulate prolactin release in pituitary cells and androgen production in Leydig cells, indicating that it acts as an endocrine disrupter both in cells that secrete by exocytosis of prestored hormones and in cells that secrete by de novo hormone synthesis. Rolipram abolished the stimulatory effect of atrazine on cAMP release in both cell types, suggesting that it acts as an inhibitor of PDE4s, isoforms whose mRNA transcripts dominate in pituitary and Leydig cells together with mRNA for PDE8A. In contrast, immortalized lacto-somatotrophs showed low expression of these mRNA transcripts and several fold higher cAMP levels compared to normal pituitary cells, and atrazine was unable to further increase cAMP levels. These results indicate that atrazine acts as a general endocrine disrupter by inhibiting cAMP-specific PDE4s. -- Highlights: ► Atrazine stimulates cAMP accumulation in pituitary and Leydig cells. ► Atrazine also stimulates PRL and androgens secretion. ► Stimulatory effects of atrazine were abolished in cells with IBMX-inhibited PDEs. ► Atrazine specificity toward c

  20. Probability of detecting atrazine/desethyl-atrazine and elevated concentrations of nitrate (NO2+NO3-N) in ground water in the Idaho part of the upper Snake River basin

    Science.gov (United States)

    Rupert, Michael G.

    1998-01-01

    Draft Federal regulations may require that each State develop a State Pesticide Management Plan for the herbicides atrazine, alachlor, cyanazine, metolachlor, and simazine. This study developed maps that the Idaho State Department of Agriculture might use to predict the probability of detecting atrazine and desethyl-atrazine (a breakdown product of atrazine) in ground water in the Idaho part of the upper Snake River Basin. These maps can be incorporated in the State Pesticide Management Plan and help provide a sound hydrogeologic basis for atrazine management in the study area. Maps showing the probability of detecting atrazine/desethyl-atrazine in ground water were developed as follows: (1) Ground-water monitoring data were overlaid with hydrogeologic and anthropogenic data using a geographic information system to produce a data set in which each well had corresponding data on atrazine use, depth to ground water, geology, land use, precipitation, soils, and well depth. These data then were downloaded to a statistical software package for analysis by logistic regression. (2) Individual (univariate) relations between atrazine/desethyl-atrazine in ground water and atrazine use, depth to ground water, geology, land use, precipitation, soils, and well depth data were evaluated to identify those independent variables significantly related to atrazine/ desethyl-atrazine detections. (3) Several preliminary multivariate models with various combinations of independent variables were constructed. (4) The multivariate models which best predicted the presence of atrazine/desethyl-atrazine in ground water were selected. (5) The multivariate models were entered into the geographic information system and the probability maps were constructed. Two models which best predicted the presence of atrazine/desethyl-atrazine in ground water were selected; one with and one without atrazine use. Correlations of the predicted probabilities of atrazine/desethyl-atrazine in ground water with

  1. Seletividade de atrazine e nicosulfuron a Podisus nigrispinus (Heteroptera: Pentatomidae Selectivity of atrazin and nicosulfurom to Podisus nigrispinus (Heteroptera: Pentatomidae

    Directory of Open Access Journals (Sweden)

    C.W.G. Menezes

    2012-06-01

    Full Text Available O milho tem sido cultivado em duas safras anuais no Brasil e consumido por humanos e animais. O uso de herbicidas no controle de plantas daninhas nessa cultura pode comprometer o ambiente em função dos efeitos sobre organismos não alvos. O objetivo deste trabalho foi avaliar a seletividade de atrazine e nicosulfuron sobre o predador Podisus nigrispinus. Os tratamentos constaram da aplicação de atrazine, nicosulfuron e da mistura destes, em doses equivalentes à comercial, mais um tratamento controle à base de água. A solução com os herbicidas foi aspergida sobre ovos de dois dias de idade de P. nigrispinuse em cada um dos cinco estádios ninfais e fase adulta do inseto. A viabilidade dos ovos de P. nigrispinus diminuiu sob ação dos herbicidas, sem eles diferirem quanto ao tempo de eclosão. A sobrevivência de ninfas foi baixa sob ação dos herbicidas, sendo mais afetada negativamente sob ação da mistura destes. Para a aplicação em cada estádio, observou-se baixa sobrevivência de ninfas do primeiro ao terceiro estádio sob ação do herbicida atrazine, isolado ou em mistura, e até o segundo estádio para o nicosulfuron. Também ficou evidente em todos os demais estádios do inseto a menor seletividade à mistura dos herbicidas, em comparação ao efeito isolado. Conclui-se que ovos de P. nigrispinus são sensíveis aos herbicidas testados e que a aplicação na cultura do milho desses produtos poderá diminuir o controle biológico de pragas promovido por esse inseto.Corn is traditionally grown in two annual harvests in Brazil and consumed by humans and animals. The use of herbicides to control weeds in this crop may compromise the environment, affecting non-target organisms. The aim of this study was to evaluate the selectivity of atrazine and nicosulfuron on the predator Podisus nigrispinus Dallas, 1851 (Heteroptera: Pentatomidae. The treatments consisted of application of a combination of atrazine and nicosulfuron in doses

  2. Influência da cobertura morta no comportamento do herbicida atrazine Influence of the mulch on the behavior of atrazine

    Directory of Open Access Journals (Sweden)

    Donizeti A. Fornarolli

    1998-12-01

    Full Text Available A cobertura morta, oriunda da dessecação ou rolagem de plantas utilizadas para esta finalidade, faz parte do sistema de semeadura direta. Ao mesmo tempo que essa cobertura promove redução na densidade populacional das espécies invasoras, intercepta os herbicidas quando aplicados sobre sua superfície. Alguns autores têm sugerido aumentar as doses dos herbicidas, o que tem gerado polêmica sobre o assunto. Com o objetivo de estudar o comportamento do herbicida atrazine sobre cobertura morta, realizaram-se experimento de campo, bioensaios e análises cromatográficas de resíduos com esse herbicida, nas doses 0,0; 1,25; 2,50; 3,75 e 5,00 kg/ha do ingrediente ativo, aplicando-o em solo descoberto e sobre cobertura morta de palha de aveia preta, com 4,5 e 9,0 t/ha. Amostras de solo de 0 a 10 cm de profundidade foram coletadas após a aplicação, antes e depois de uma irrigação de 20 mm para uso em bioensaios e análises cromatográficas de resíduo. A irrigação foi realizada 24 horas após a aplicação do herbicida. Os resultados mostraram que, nas amostras de solo coletadas antes da irrigação, 85% de cada dose foi interceptada nos dois tratamentos com cobertura morta. A irrigação de 20 mm foi suficiente para lixiviar praticamente todo o herbicida da palha para o solo, não havendo diferença significativa com os teores encontrados em solo descoberto. A cobertura morta reduziu a população de Brachiaria plantaginea, única espécie presente no experimento, para 20 e 5 plantas/m2, respectivamente, nas coberturas com 4,5 e 9,0 t/ha de matéria seca, enquanto que em solo descoberto, a população da espécie foi de 700 plantas/m2. Os controles obtidos com as doses de 1,25 kg/ha, nas duas quantidades de palha estudadas, foram superiores ao controle obtido com a dose de 5,00 kg/ha em solo descoberto, indicando que a cobertura morta, por sí só, exerce bom controle de B. plantaginea. A ocorrência de chuva após a aplicação de atrazine

  3. Impact of atrazine prohibition on the sustainability of weed management in Wisconsin maize production.

    Science.gov (United States)

    Dong, Fengxia; Mitchell, Paul D; Davis, Vince M; Recker, Ross

    2017-02-01

    Controversy has surrounded atrazine owing to its susceptibility to leaching and run-off, with regular calls for a ban or restrictions on its use. In the context of a decreasing trend in the percentage of US maize using no-till since 2008, coinciding with the trend of glyphosate-resistant weeds becoming problematic in the Midwestern United States, we empirically examine how atrazine use restrictions have impacted the diversity of weed management practices used by Wisconsin maize farmers. Using survey data from farms inside and outside atrazine prohibition areas, we found that prohibiting atrazine did not directly impact tillage practices, but rather it increased the adoption of herbicide-resistant seed, which then increased adoption of conservation tillage systems. We also found that prohibiting atrazine and using herbicide-resistant seed reduced the number of herbicide sites of action used. The results indicate that prohibiting atrazine reduced the diversity of weed management practices, which increased the risk of herbicide resistance. Our concern is that a regulatory policy to address one issue (atrazine in groundwater) has induced farmer responses that increase problems with another issue (herbicide-resistant weeds) that longer term will contribute to water quality problems from increased soil erosion and offset the initial benefits. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  4. [Adsorption characteristics and mechanism of atrazine on three types of humic acid].

    Science.gov (United States)

    Chang, Chun-ying; Zheng, Yin-tian; Lü, Yi-zhong

    2010-10-01

    This study mainly researched the adsorption properties and adsorption mechanism of atrazine on three different types of humic acids: the black soil humic acid, the chestnut soil humic acid and the humic acid purchased. After the extraction of humic acid from the two different types of soil, the black soil and chestnut soil, adsorption experiments were carried out using the batch equilibrium techniques. Then FTIR and ESR spectral analysis methods were employed to explain the functional mechanism between atrazine and humic acid. The results showed that the sorption of humic acid on atazine was very fast at the beginning, then went to slower and finally came to equilibrium. The relationship between the amount of atrazine sorbed by the three humic acids and reaction time all fitted logarithmic and hyperbolic equations well. Adsorption isotherms of atrazine on the three humic acids all are L-type and in accordance with the linear model and the Freundlich model. Because of the different structure, there is significant difference between the adsorption isotherm of atrazine on purchased humic acid and extract humic acid. The interactions between humic acid and atrazine are mostly weak forces, such as the H-bond, proton transfer, charge transfer, van der Waals force and so on. In addition, ESR analysis proved that charge transfer exists between humic acid and atrazine during the process of adsorption.

  5. Integrated Approach to Mathematical Modelling of Atrazine Degradation in Different Reaction Systems

    Directory of Open Access Journals (Sweden)

    Marijan Bošnjak

    2010-01-01

    Full Text Available Based on the known approaches and published mathematical models, as well as on theoretical consideration using our experimental data, the integrated approach to mathematical modelling of atrazine biodegradation processes has been employed and sophisticated mathematical models for different reaction systems have been developed. The applicability of these models which take into account physical, chemical, biochemical and biological complexity of atrazine biodegradation was further analyzed in comparison with mathematical models describing simple consecutive reaction systems using first-order kinetics. Kinetics of atrazine degradation in liquid media and soil contaminated with atrazine at the temperatures of 10 and 30 °C was assessed and compared. Biodegradation experiments in liquid media were conducted at atrazine concentrations ranging from 0.14 to 25 mmol/L, while the experiments in soil were conducted at atrazine concentration of approx. 0.44 μmol/g. Computer simulations were applied to explain experimental results and test the adequacy of mathematical models. Detailed analysis of computer simulation data showed that the developed integrated mathematical models could be considered as the most convenient for describing kinetics of atrazine biotransformation in both liquid media and contaminated soil, although even simple mathematical models are suitable for explaining some experimental results, especially when evaluating the temperature effects on biodegradation efficacy of the applied mixed bacterial culture.

  6. Removal of atrazine in water by combination of activated carbon and dielectric barrier discharge

    Energy Technology Data Exchange (ETDEWEB)

    Vanraes, Patrick, E-mail: patrick.vanraes@ugent.be [Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Gent (Belgium); Willems, Gert; Nikiforov, Anton [Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Gent (Belgium); Surmont, Pieter; Lynen, Frederic [Separation Science Group, Department of Organic Chemistry, Ghent University, Krijgslaan 281 S4-bis, 9000 Gent (Belgium); Vandamme, Jeroen; Van Durme, Jim [Research Group Molecular Odor Chemistry, Department of Microbial and Molecular Systems (M2S), KU Leuven, Technology Campus, Gebroeders De Smetstraat 1, 9000 Gent (Belgium); Verheust, Yannick P.; Van Hulle, Stijn W.H.; Dumoulin, Ann [Department of Industrial Biological Sciences, Ghent University, Graaf Karel de Goedelaan 5, 8500 Kortrijk (Belgium); Leys, Christophe [Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Gent (Belgium)

    2015-12-15

    Highlights: • Increasing input power with a factor 3.5 leads to deeper atrazine oxidation without significantly changing energy yield of atrazine removal. • Chlorine containing oxidation by-products of first and later generations are detected with HPLC–MS analysis, in agreement with literature. • Desorption analysis shows lower atrazine concentration and higher by-product concentration on activated carbon textile after plasma treatment. • Comparison with plasma reactors described in literature for atrazine decomposition confirms relatively high energy efficiency of our reactor. - Abstract: Efficiency of modern wastewater treatment plants to remove or decompose persistent contaminants in low concentration is often insufficient to meet the demands imposed by governmental laws. Novel, efficient and cheap methods are required to address this global issue. We developed a new type of plasma reactor, in which atrazine decomposition by atmospheric dielectric barrier discharge (DBD) in dry air is combined with micropollutant adsorption on activated carbon textile and with extra bubbling of generated ozone. Investigation of reaction kinetics and by-product analysis shows that increasing input power with a factor 3.5 leads to deeper atrazine oxidation without significantly changing energy yield of atrazine removal. By-products of first and later generations are detected with HPLC–MS analysis in water and adsorbed on the activated carbon textile. Our reactor is compared in energy efficiency with reactors described in literature, showing that combination of plasma discharge with pollutant adsorption and ozone recycling is attractive for future applications of water treatment.

  7. Atrazine and metribuzin sorption in soils of the Argentinean humid pampas.

    Science.gov (United States)

    Daniel, Peter E; Bedmar, Francisco; Costa, José L; Aparicio, Virginia C

    2002-12-01

    Laboratory studies were conducted to determine the influence of surface and subsurface properties of three representative soils of the humid pampas of Argentina on atrazine and metribuzin sorption. Atrazine and metribuzin sorption isotherms were constructed for each soil at four depths. Sorption affinity of herbicides was approximated by the Freundlich constant (K(f)), distribution coefficient (Kd), and the normalized Kd based on organic carbon content (K(oc)). Multiple regression of the sorption constants against selected soil properties indicated that organic carbon content (OC) and silt were related positively and negatively, respectively, to atrazine K(f) coefficient (r2 = 0.93), while Kd coefficient of atrazine was related positively to organic carbon content and negatively to both silt and cation exchange capacity (CEC) (r2 = 0.96). For metribuzin, only organic matter content was related positively to Kr coefficient (r2 = 0.51). Lower K(f) values for atrazine were obtained for all soils with increasing depth, indicating lesser sorption at greater depths. Metribuzin sorption was quite similar across all depths. Sorption constant K(f) of atrazine ranged from 2.06 to 7.82, while metribuzin K(f) values ranged from 1.8 to 3.52 and were lower than atrazine for all soils and depths, indicating a greater leaching potential across the soil profile.

  8. Transcriptome analysis of Glomus mosseae/Medicago sativa mycorrhiza on atrazine stress.

    Science.gov (United States)

    Song, Fuqiang; Li, Jize; Fan, Xiaoxu; Zhang, Quan; Chang, Wei; Yang, Fengshan; Geng, Gui

    2016-02-02

    Arbuscular mycorrhizal fungi (AMF) protect host plants against diverse biotic and abiotic stresses, and promote biodegradation of various contaminants. In this study effect of Glomus mosseae/Medicago sativa mycorrhiza on atrazine degradation was investigated. It was observed that the atrazine degradation rates with any addition level in mycorrhizal treatments were all significantly higher than those in non-mycorrhizal treatments. When atrazine was applied at 20 mg kg(-1), the removal efficiency was up to 74.65%. Therefore, G. mosseae can be considered as ideal inhabitants of technical installations to facilitate phytoremediation. Furthermore, a total of 10.4 Gb was used for de novo transcriptome assembly, resulting in a comprehensive data set for the identification of genes corresponding to atrazine stress in the AM association. After comparative analysis with edgeR, a total of 2,060 differential expressed genes were identified, including 570 up-regulated genes and 1490 down-regulated genes. After excluding 'function unknown' and 'general function predictions only' genes, 172 up-regulated genes were obtained. The differentially expressed genes in AM association with and without atrazine stress were associated with molecular processes/other proteins, zinc finger protein, intracellular/extracellular enzymes, structural proteins, anti-stress/anti-disease protein, electron transport-related protein, and plant growth associated protein. Our results not only prove AMF has important ecological significance on atrazine degradation but also provide evidence for the molecular mechanisms of atrazine degradation by AMF.

  9. Antibody conjugated glycine doped polyaniline nanofilms as efficient biosensor for atrazine

    Science.gov (United States)

    Bhardwaj, Sanjeev K.; Sharma, Amit L.; Kim, Ki-Hyun; Deep, Akash

    2017-12-01

    Atrazine is an important member of triazine family of pesticides. The development of its detection methods gained great attention due to the potential health risks associated with its contamination in various media including water, soil, and food. The contamination of atrazine in drinking water beyond the legal permissible limit of EPA (e.g. 3 ng ml‑1) may cause various damages to living organisms (e.g. heart, urinary, and limb defects). In this research, we discuss the potential significance of a highly sensitive conductometric immunosensor for sensing the atrazine pesticide. To this end, electrochemical assembly of glycine doped polyaniline (PAni) nanofilms on silicon (Si) substrate was built and modified further with anti-atrazine antibodies. The herein developed immunosensor offered highly sensitive detection of atrazine with a low detection limit of 0.07 ng ml‑1. The proposed biosensor was simple in design with excellent performance in terms of its sensitivity, stability and specificity. Highlights •Glycine doped PAni nanofilms have been electropolymerized on Silicon substrates. •Functionality of the above thin films provides opportunity to develop an immunosensing platform. •Highly sensitive and specific detection of atrazine has been realized over a wide concentration range with a LOD of 0.07 ng ml‑1. Novelty statement Atrazine is a widely used pesticide in the agriculture sector. It is highly recommended to develop simple biosensing systems for enabling the prospect of routine monitoring. The present research for the first time proposes the design of a glycine doped PAni based simple and highly effective biosensor for the atrazine pesticide. The doping of glycine has easily generated functional groups on the nano-PAni material for further convenient immobilization of anti-atrazine antibodies. The proposed sensor can be highlighted with advantages like ease of fabrication, use of environment friendly functionalization agent, specificity

  10. [Effects of nitrogen and phosphorus fertilizer on atrazine degradation and detoxification by degrading strain HB-5].

    Science.gov (United States)

    Su, Jun; Zhu, Lu-Sheng; Li, Xu-Hua; Wang, Jun; Xie, Hui; Wang, Jin-Hua; Wang, Qi; Jia, Wen-Tao

    2010-10-01

    An atrazine-degrading strain HB-5 was used as a bacteria for biodegradation. Treatments of soil with nitrogen single, phosphate single and nitrogen phosphate together with HB-5 were carried out for degradation and eco-toxicity test; then, relationship between atrazine degradation rate and soil available nitrogen, available phosphorus were discussed. Atrazine residues were determined by HPLC; available nitrogen was determined with alkaline hydrolysis diffusion method; available phosphorus was determined with 0.5 mol/L-NaHCO3 extraction and molybdenum stibium anti-color method, and toxicity test was carried out with micronucleus test of Vicia faba root tip cells. The results showed that: After separately or together application, nitrogenous and phosphorous fertilizers could significantly accelerate atrazine degradation than soil with HB-5 only. On day 5, the order of atrazine degradation was ANP > AP > AN > A; 7 days later, no statistically significant differences were found between treatments. The available nitrogen and phosphorus level in soil reduced as the degradation rate increased in the soil. The soil of eco-toxicity test results indicated that the eco-toxicity significantly reduced with the degradation of atrazine by HB-5, and the eco-toxicity on treatments of soil with fertilizer were all below the treatments without fertilizer. On day 5, the order of eco-toxicity was ANP < AP < AN < A; 7 days later, all treatments were decreased in control levels. So, adjusting soil nutrient content could not only promote atrazine degradation in soil but also could reduce the soil eco-toxicity effects that atrazine caused. All these results could be keystone of atrazine pollution remediation in contaminated soil in the future.

  11. Sorption and distribution of aged atrazine residues in the drainage system of an outdoor lysimeter experiment

    Science.gov (United States)

    Jablonowski, N. D.; Schäffer, A.; Burauel, P.

    2009-04-01

    Even though the environmental impact of the herbicide atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] is a matter of controversy, it is still extensively applied for agricultural purposes. Particularly in the US, atrazine has been applied to approximately 70% of all corn acreages in the last 18 years. Atrazine is banned in the EU but its use is increasing in countries like China, Brazil and India. Therefore, the worldwide soil burden of this compound must be enormous. Atrazine has been found to be highly persistent in the environment and it has been suggested that it is moderately mobile in the soil profile. As a result, it is found in most groundwater aquifers and surface waters in agricultural areas in the US. Even in Germany, where it was prohibited in 1991, it is still found in groundwater wells below agriculturally used land where it was formerly applied. For a long-term outdoor lysimeter experiment with a disturbed soil column, a drainage system of fine gravel was originally embedded at the bottom of the lysimeter. In this drainage system, atrazine and its metabolite 2-hydroxy-atrazine were extracted as long as 22 years after the last atrazine application. Due to the radiolabelling, the spatial distribution of the atrazine residues can be evaluated in fractions like fine clay particles attached to the gravel or in the gravel itself. Approximately 2% of the total gravel consisted of carbonaceous, slag-like particles which might retain most of the atrazine and its residues. The latest data will be presented at the session.

  12. 75 FR 62002 - Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350...

    Science.gov (United States)

    2010-10-07

    ... Maintenance Manual (AMM) of PC-6 B2-H2 and B2-H4 models does not include a Chapter 04 in the Airworthiness Limitations Section (ALS). For PC-6 models other than B2-H2 and B2- H4, no ALS at all is included in the AMM. With the latest Revision 12 of the AMM, a new Chapter 04 has been introduced in the AMM for PC-6 B2-H2...

  13. 76 FR 5467 - Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350...

    Science.gov (United States)

    2011-02-01

    ... Maintenance Manual (AMM) of PC-6 B2-H2 and B2-H4 models does not include a Chapter 04 in the Airworthiness Limitations Section (ALS). For PC-6 models other than B2-H2 and B2- H4, no ALS at all is included in the AMM. With the latest Revision 12 of the AMM, a new Chapter 04 has been introduced in the AMM for PC-6 B2-H2...

  14. Phytotoxicity of atrazine, S-metolachlor, and permethrin to Typha latifolia (Linneaus) germination and seedling growth.

    Science.gov (United States)

    Moore, M T; Locke, M A

    2012-08-01

    Phytotoxicity assessments were performed to compare responses of Typha latifolia (L.) seeds to atrazine (only) and atrazine + S-metolachlor exposure concentrations of 0.03, 0.3, 3, and 30 mg L(-1), as well as permethrin exposure concentrations of 0.008, 0.08, 0.8, and 8 mg L(-1). All atrazine + S-metolachlor exposures resulted in significantly reduced radicle development (p latifolia seeds to pesticides commonly encountered in agricultural settings, as well as critical understanding and development of using T. latifolia in phytoremediation efforts for pesticide exposures.

  15. Degradation of the Pesticides Mecoprop and Atrazine in Unpolluted Sandy Aquifers

    DEFF Research Database (Denmark)

    Klint, Mikala; Arvin, Erik; Jensen, Bjørn K.

    1993-01-01

    The potential for biodegradation of the pesticides mecoprop ((+/-)-2-(4-chloro-2-methyl-phenoxy)propionic acid) and atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) in an aerobic aquifer was investigated in laboratory batch experiments. The experiments were performed with groundwater...... the aquifer. Atrazine was not degraded during an incubation period of 539 d in groundwater and 174 d in suspensions of groundwater and aquifer sediment. The addition of nutrients, primary substrates (acetate and naphthalene), and a pH or temperature increase had not effect on the recalcitrance of atrazine....

  16. Pathway Controlled Penetration (PcP)

    Energy Technology Data Exchange (ETDEWEB)

    Knight, Earl E. [Los Alamos National Laboratory; Rougier, Esteban [Los Alamos National Laboratory; Zubelewicz, Aleksander [Los Alamos National Laboratory

    2012-08-29

    The technical approach employs advanced computational simulation tools to demonstrate how current assets can destroy RWK-RFI-12-0001's HDBT, a tunnel complex with two portals built into the base of a granite mountain. The granite over layer is assumed to be 60 meters thick over both portals and 80 meters over the facility's mission space. Key S&T is the completed development of a highly innovative viscoplastic fracture material model, 3D parallel gas-fracture capabilities into FDEM, and a stochastic handling of the material properties. Phase I - Develop and validate code simulation tools: (1) develop, incorporate and validate AZ-Frac material model for granite; and (2) Develop and incorporate gas-driven-fracture modeling into LANL's FDEM MUNROU code; (3) Develop and incorporate stochastic features into FDEM modeling. Phase II - Conduct PcP analysis on above HDBT: (1) Acquire HDBT design data, develop simulation model; and (2) Evaluate and select most promising defeat alternative. Phase III - Deliver code, train Service target analysts, and conduct simulations against real world HDBTs. PcP uses advanced computer simulations to enhance HDBT functional defeat efforts. Newly developed material models that account for fractural energy coupled with the finite discrete element methodology (FDEM) will provide targeting packages that will create penetration avenues for current or future lethality options. This novel computational approach requires full 3D geologic and structure characterization as well as significant high performance computing capabilities. The goal is to distinctively alter the targeting paradigm by leveraging critical DoD assets along with insitu geologic strata. In other words, assets will utilize underground rock structure to their benefit by creating rubbilization zones that will allow pathway controlled penetration.

  17. Effects of Short Term Exposure of Atrazine on the Liver and Kidney of Normal and Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Dinesh Babu Jestadi

    2014-01-01

    Full Text Available The present study evaluates the effects of short term (15 days exposure of low dose (300 μg kg−1 of atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine on antioxidant status and markers of liver and kidney damage in normal (nondiabetic and diabetic male Wistar rats. Rats were divided into four groups: Group I as normal control, Group II as atrazine treated, Group III as diabetic control, and Group IV as atrazine treated diabetic rats. Atrazine administration resulted in increased MDA concentration as well as increased activities of SOD, CAT, and GPx in both liver and kidney of atrazine treated and atrazine treated diabetic rats. However, GSH level was decreased in both liver and kidney of atrazine treated and atrazine treated diabetic rats. Atrazine administration led to significant increase in liver damage biomarkers such as AST, ALT, and ALP as well as kidney damage biomarkers such as creatinine and urea in both normal and diabetic rats, but this increase was more pronounced in diabetic rats when compared to normal rats. In conclusion, the results of the present study demonstrate that short term exposure of atrazine at a dose of 300 μg kg−1 could potentially induce oxidative damage in liver and kidney of both normal and diabetic rats.

  18. Characterization of bacterial diversity in an atrazine degrading enrichment culture and degradation of atrazine, cyanuric acid and biuret in industrial wastewater.

    Science.gov (United States)

    Dutta, Anirban; Vasudevan, Venugopal; Nain, Lata; Singh, Neera

    2016-01-01

    An enrichment culture was used to study atrazine degradation in mineral salt medium (MSM) (T1), MSM+soil extract (1:1, v/v) (T2) and soil extract (T3). Results suggested that enrichment culture required soil extract to degrade atrazine, as after second sequential transfer only partial atrazine degradation was observed in T1 treatment while atrazine was completely degraded in T2 and T3 treatments even after fourth transfer. Culture independent polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique confirmed selective enrichment of genus Bacillus along with Pseudomonas and Burkholderia. Degradation of atrazine/metabolites in the industrial wastewater was studied at different initial concentrations of the contaminants [wastewater-water (v/v) ratio: T1, 1:9; T2, 2:8; T3, 3:7; T4, 5:5 and T5, undiluted effluent]. The initial concentrations of atrazine, cyanuric acid and biuret ranged between 5.32 and 53.92 µg mL(-1), 265.6 and 1805.2 µg mL(-1) and 1.85 and 16.12 µg mL(-1), respectively. The enrichment culture was able to completely degrade atrazine, cyanuric acid and biuret up to T4 treatment, while no appreciable degradation of contaminants was observed in the undiluted effluent (T5). Inability of enrichment culture to degrade atrazine/metabolites might be due to high concentrations of cyanuric acid. Therefore, a separate study on cyanuric acid degradation suggested: (i) no appreciable cyanuric acid degradation with accumulation of an unidentified metabolite in the medium where cyanuric acid was supplemented as the sole source of carbon and nitrogen; (ii) partial cyanuric acid degradation with accumulation of unidentified metabolite in the medium containing additional nitrogen source; and (iii) complete cyanuric acid degradation in the medium supplemented with an additional carbon source. This unidentified metabolite observed during cyanuric acid degradation and also detected in the enrichment culture inoculated wastewater samples

  19. Comparative transcriptomic responses to chronic cadmium, fluoranthene, and atrazine exposure in Lumbricus rubellus

    NARCIS (Netherlands)

    Svendsen, C.; Owen, J.; Kille, P.; Wren, J.; Jonker, M.J.; Headley, B.A.; Morgan, A.J.; Blaxter, M.; Stürzenbaum, S.R.; Hankard, P.K.; Lister, L.J.; Spurgeon, D.J.

    2008-01-01

    Transcriptional responses of a soil-dwelling organism (the earthworm Lumbricus rubellus) to three chemicals, cadmium (Cd), fluoranthene (FA), and atrazine (AZ), were measured following chronic exposure, with the aim of identifying the nature of any shared transcriptional response. Principal

  20. Molecular characterization of atrazine resistance in common ragweed (Ambrosia artemisiifolia L.).

    Science.gov (United States)

    Cseh, A; Cernak, I; Taller, J

    2009-01-01

    Common ragweed (Ambrosia artemisiifolia L.) is the most frequent weed in the Carpathian Basin and is spreading fast in other parts of Europe. In recent years, besides the wild type, a mutant genotype resistant to atrazine herbicides has evolved and is now widespread in many areas. The present study demonstrates that the atrazine resistance of ragweed is maternally inherited, and is caused by a point mutation in the psbA chloroplast gene. The promoter 5'-untranslated region and the open reading frame regions of the gene were analysed, and a homology search was performed. Both the atrazine-resistant and susceptible types of cpDNA were present in atrazine-resistant plants, while the mixed presence of both genotypes in the same plant, known as heteroplasmy, was not unequivocally detectable in susceptible plants.

  1. ICAN - INTEGRATED COMPOSITE ANALYZER (IBM PC VERSION)

    Science.gov (United States)

    Murthy, P. L.

    1994-01-01

    The Integrated Composite Analyzer (ICAN) is a computer program designed to carry out a comprehensive linear analysis of multilayered fiber composites. The analysis contains the essential features required to effectively design structural components made from fiber composites. ICAN includes the micromechanical design features of the Intraply Hybrid Composite Design (INHYD) program to predict ply level hygral, thermal, and mechanical properties. The laminate analysis features of the Multilayered Filamentary Composite Analysis (MFCA) program are included to account for interply layer effects. ICAN integrates these and additional features to provide a comprehensive analysis capability for composite structures. Additional features unique to ICAN include the following: 1) ply stress-strain influence coefficients, 2) microstresses and microstrain influence coefficients, 3) concentration factors around a circular hole, 4) calculation of probable delamination locations around a circular hole, 5) Poisson's ratio mismatch details near a straight edge, 6) free-edge stresses, 7) material card input for finite element analysis using NASTRAN (available separately from COSMIC) or MARC, 8) failure loads based on maximum stress criterion, and laminate failure stresses based on first-ply failures and fiber breakage criteria, 9) transverse shear stresses, normal and interlaminar stresses, and 10) durability/fatigue type analyses for thermal as well as mechanical cyclic loads. The code can currently assess degradation due to mechanical and thermal cyclic loads with or without a defect. ICAN includes a dedicated data bank of constituent material properties, and allows the user to build a database of material properties of commonly used fibers and matrices so the user need only specify code names for constituents. Input to ICAN includes constituent material properties (or code names), factors reflecting the fabrication process, and composite geometry. ICAN performs micromechanics

  2. Response of ligninolytic macrofungi to the herbicide atrazine: dose-response bioassays.

    Science.gov (United States)

    Cupul, Wilberth Chan; Abarca, Gabriela Heredia; Vázquez, Refugio Rodríguez; Salmones, Dulce; Hernández, Rigoberto Gaitán; Gutiérrez, Enrique Alarcón

    2014-01-01

    The effect of atrazine concentrations on mycelial growth and ligninolytic enzyme activities of eight native ligninolytic macrofungi isolated in Veracruz, México, were evaluated in a semi-solid culture medium. Inhibition of mycelial growth and growth rates were significantly affected (p=0.05) by atrazine concentrations (468, 937, 1875, and 3750 mg/l). In accordance with the median effective concentration (EC50), Pleurotus sp. strain 1 proved to be the most tolerant isolate to atrazine (EC50=2281.0 mg/l), although its enzyme activity was not the highest. Pycnoporus sanguineus strain 2, Daedalea elegans and Trametes maxima showed high laccase activity (62.7, 31.9, 29.3 U mg/protein, respectively) without atrazine (control); however, this activity significantly increased (p<0.05) (to 191.1, 83.5 and 120.6 U mg/protein, respectively) owing to the effect of atrazine (937 mg/l) in the culture medium. Pleurotus sp. strain 2 and Cymatoderma elegans significantly increased (p<0.05) their manganese peroxidase (MnP) activities under atrazine stress at 468 mg/l. The isolates with high EC50 (Pleurotus sp. strain 1) and high enzymatic activity (P. sanguineus strain 2 and T. maxima) could be considered for future studies on atrazine mycodegradation. Furthermore, this study confirms that atrazine can increase laccase and MnP activities in ligninolytic macrofungi. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España. All rights reserved.

  3. Theoretical study of the atrazine pesticide interaction with pyrophyllite and Ca(2+) -montmorillonite clay surfaces.

    Science.gov (United States)

    Belzunces, Bastien; Hoyau, Sophie; Benoit, Magali; Tarrat, Nathalie; Bessac, Fabienne

    2017-01-30

    Atrazine, a pesticide belonging to the s-triazine family, is one of the most employed pesticides. Due to its negative impact on the environment, it has been forbidden within the European Union since 2004 but remains abundant in soils. For these reasons, its behavior in soils and water at the atomic scale is of great interest. In this article, we have investigated, using DFT, the adsorption of atrazine onto two different clay surfaces: a pyrophyllite clay and an Mg-substituted clay named montmorillonite, with Ca(2+) compensating cations on its surface. The calculations show that the atrazine molecule is physisorbed on the pyrophyllite surface, evidencing the necessity to use dispersion-corrected computational methods. The adsorption energies of atrazine on montmorillonite are two to three times larger than on pyrophyllite, depending on the adsorption pattern. The computed adsorption energy is of about -30 kcal mol(-1) for the two most stable montmorillonite-atrazine studied isomers. For these complexes, the large adsorption energy is related to the strong interaction between the chlorine atom of the atrazine molecule and one of the Ca(2+) compensating cations of the clay surface. The structural modifications induced by the adsorption are localized: for the surface, close to substitutions and particularly below the Ca(2+) cations; in the molecule, around the chlorine atom when Ca(2+) interacts strongly with this basic site in a monodentate mode. This study shows the important role of the alkaline earth cations on the adsorption of atrazine on clays, suggesting that the atrazine pesticide retention will be significant in Ca(2+) -montmorillonite clays. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  4. Menstrual cycle characteristics and reproductive hormone levels in women exposed to atrazine in drinking water.

    Science.gov (United States)

    Cragin, Lori A; Kesner, James S; Bachand, Annette M; Barr, Dana Boyd; Meadows, Juliana W; Krieg, Edward F; Reif, John S

    2011-11-01

    Atrazine is the most commonly used herbicide in the U.S. and a wide-spread groundwater contaminant. Epidemiologic and laboratory evidence exists that atrazine disrupts reproductive health and hormone secretion. We examined the relationship between exposure to atrazine in drinking water and menstrual cycle function including reproductive hormone levels. Women 18-40 years old residing in agricultural communities where atrazine is used extensively (Illinois) and sparingly (Vermont) answered a questionnaire (n=102), maintained menstrual cycle diaries (n=67), and provided daily urine samples for analyses of luteinizing hormone (LH), and estradiol and progesterone metabolites (n=35). Markers of exposures included state of residence, atrazine and chlorotriazine concentrations in tap water, municipal water and urine, and estimated dose from water consumption. Women who lived in Illinois were more likely to report menstrual cycle length irregularity (odds ratio (OR)=4.69; 95% confidence interval (CI): 1.58-13.95) and more than 6 weeks between periods (OR=6.16; 95% CI: 1.29-29.38) than those who lived in Vermont. Consumption of >2 cups of unfiltered Illinois water daily was associated with increased risk of irregular periods (OR=5.73; 95% CI: 1.58-20.77). Estimated "dose" of atrazine and chlorotriazine from tap water was inversely related to mean mid-luteal estradiol metabolite. Atrazine "dose" from municipal concentrations was directly related to follicular phase length and inversely related to mean mid-luteal progesterone metabolite levels. We present preliminary evidence that atrazine exposure, at levels below the US EPA MCL, is associated with increased menstrual cycle irregularity, longer follicular phases, and decreased levels of menstrual cycle endocrine biomarkers of infertile ovulatory cycles. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Photocatalytic degradation of atrazine using TiO{sub 2}-impregnated mesh

    Energy Technology Data Exchange (ETDEWEB)

    Kiserow, D.J.; Pugh, K.C.

    1994-10-01

    TiO{sub 2} photocatalysis is investigated is a potential means for the disposal of pesticide rinsate waste at agrochemical dealerships. The focus is an evaluation of parameters that affect the rate and mechanism of atrazine degradation using formulated atrazine (ca. 20-25 ppm), TiO{sub 2} mesh, a high-pressure mercury-vapor lamp, and solar irradiation. The UV transmission of a variety of transparent materials was measured and atrazine photocatalysis was carried out using several materials as reactor covers. The pseudo-first-order rate constants were calculated and compared to determine which cover results in the most efficient atrazine degradation. A clear acrylic gave results nearly identical to Pyrex and was chosen for future photocatalytic experiments. UV intensity and photocatalytic rate were studied as a function of different numbers of layers of TiO{sub 2} mesh. It was found that five layers give the optimum rate of degradation without employing excess mesh. In order to assess the general effect of impurities present in water on the rate of atrazine degradation, water from five different sources was obtained and each sample was analyzed for purity and used to prepare aqueous atrazine for photocatalytic degradation. The results show that contaminants specific to different locations are likely to inhibit the rate of photocatalysis to different degrees. While working to maximize the rate of atrazine degradation, studies are concurrently in progress to elucidate the mechanism of degradation for the experimental conditions employed herein. Initial results indicate that the overall degradation of atrazine to the reported end product, cyanuric acid, occurs by two distinct pathways of similar importance.

  6. Summer cover crops reduce atrazine leaching to shallow groundwater in southern Florida.

    Science.gov (United States)

    Potter, Thomas L; Bosch, David D; Joo, Hyun; Schaffer, Bruce; Muñoz-Carpena, Rafael

    2007-01-01

    At Florida's southeastern tip, sweet corn (Zea Mays) is grown commercially during winter months. Most fields are treated with atrazine (6-chloro-N-ethyl-N'-[1-methylethyl]-1,3,5-triazine-2,4-diamine). Hydrogeologic conditions indicate a potential for shallow groundwater contamination. This was investigated by measuring the parent compound and three degradates--DEA (6-chloro-N-[1-methylethyl]-1,3,5-triazine-2,4-diamine), DIA (6-chloro-N-ethyl)-1,3,5-triazine-2,4-diamine, and HA (6-hydroxy-N-[1-methylethyl]-1,3,5-triazine-2,4-diamine)--in water samples collected beneath sweet corn plots treated annually with the herbicide. During the study, a potential mitigation measure (i.e., the use of a cover crop, Sunn Hemp [Crotalaria juncea L.], during summer fallow periods followed by chopping and turning the crop into soil before planting the next crop) was evaluated. Over 3.5 yr and production of four corn crops, groundwater monitoring indicated leaching of atrazine, DIA, and DEA, with DEA accounting for more than half of all residues in most samples. Predominance of DEA, which increased after the second atrazine application, was interpreted as an indication of rapid and extensive atrazine degradation in soil and indicated that an adapted community of atrazine degrading organisms had developed. A companion laboratory study found a sixfold increase in atrazine degradation rate in soil after three applications. Groundwater data also revealed that atrazine and degradates concentrations were significantly lower in samples collected beneath cover crop plots when compared with concentrations below fallow plots. Together, these findings demonstrated a relatively small although potentially significant risk for leaching of atrazine and its dealkylated degradates to groundwater and that the use of a cover crop like Sunn Hemp during summer months may be an effective mitigation measure.

  7. Environmental behavior and toxicity of herbicides atrazine and simazine

    Directory of Open Access Journals (Sweden)

    Ana Paula Barbosa do Carmo

    2013-04-01

    Full Text Available This article shows some environmental and toxicology aspects of triazine herbicides atrazine and simazine. These compounds are used to control weeds in sugar and corn crops. Despite being partially soluble, they can be detected in ground and surface water. Their mobility and biodegradation in the soil-water system can vary depending on the intrinsic characteristics of each matrice, such as organic matter content. Although considered slightly toxic, these herbicides have a strong ability to interfere in the nervous and endocrine systems of human and wild biota. The detoxification mechanisms are similar to other xenobiotics; however, little is known about the effects on human health caused by simazine. Therefore, the use of these compounds should be revised due to their environmental behavior and toxicological effects.

  8. Transfer Of Baffle Data Between Macintosh PC And APART

    Science.gov (United States)

    Wise, Timothy D.; Ely, Philip A.

    1989-04-01

    Opto-mechanical systems which are entered into APART for straylight analysis frequently start out as models on a mechanical drafting program such as ANVIL. A translator, described elsewhere, has been coded in FORTRAN which will create the commands for a program one input file in APART based on an existing mechanical model in ANVIL. Having established this link, it is desirable to transfer the resulting opto-mechanical model to a personal computer (PC) for the purpose of report generation. Even more interesting is the ability to modify this model on the PC or to originate a completely new model on the PC for uplink to ANVIL. Using the program CADMOVER, we have effected two way transfers between a VAX computer and an Apple MacIntosh computer. Examples of this activity are provided.

  9. Examining the joint toxicity of chlorpyrifos and atrazine in the aquatic species: Lepomis macrochirus, Pimephales promelas and Chironomus tentans

    Energy Technology Data Exchange (ETDEWEB)

    Tyler Mehler, W.; Schuler, Lance J. [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University at Carbondale, Carbondale, IL 62901-6511 (United States); Lydy, Michael J. [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University at Carbondale, Carbondale, IL 62901-6511 (United States)], E-mail: mlydy@siu.edu

    2008-03-15

    The joint toxicity of chlorpyrifos and atrazine was compared to that of chlorpyrifos alone to discern any greater than additive response using both acute toxicity testing and whole-body residue analysis. In addition, acetylcholinesterase (AChE) inhibition and biotransformation were investigated to evaluate the toxic mode of action of chlorpyrifos in the presence of atrazine. The joint toxicity of atrazine and chlorpyrifos exhibited no significant difference in Lepomis macrochirus compared to chlorpyrifos alone; while studies performed with Pimephales promelas and Chironomus tentans, did show significant differences. AChE activity and biotransformation showed no significant differences between the joint toxicity of atrazine and chlorpyrifos and that of chlorpyrifos alone. From the data collected, the combination of atrazine and chlorpyrifos pose little additional risk than that of chlorpyrifos alone to the tested fish species. - The joint toxicity between atrazine and chlorpyrifos caused greater than additive responses in invertebrates, but the interactions in vertebrates was less pronounced.

  10. Ageing of atrazine in manure amended soils assessed by bioavailability to Pseudomonas sp. strain ADP

    DEFF Research Database (Denmark)

    Glæsner, Nadia; Bælum, Jacob; Strobel, Bjarne W.

    2014-01-01

    Animal manure is applied to agricultural land in areas of high livestock production. In the present study, we evaluated ageing of atrazine in two topsoils with and without addition of manure and in one subsoil. Ageing was assessed as the bioavailability of atrazine to the atrazine mineralizing ba......-treated and untreated soil. The present study illustrates that not simply the organic carbon content influences adsorption and ageing of atrazine in soil but the origin and composition of organic matter plays an important role....... bacteria Pseudomonas sp. strain ADP. Throughout an ageing period of 90 days bioavailability was investigated at days 1, 10, 32, 60 and 90, where ~108 cells g−1 of the ADP strain was inoculated to the 14C-atrazine exposed soil and 14CO2 was collected over 7 days as a measure of mineralized atrazine. Even...... though the bioavailable residue decreased in all of the three soils as time proceeded, we found that ageing occurred faster in the topsoils rich in organic carbon than in subsoil. For one topsoil rich in organic carbon content, Simmelkær, we observed a higher degree of ageing when treated with manure...

  11. Plastic antibody based surface plasmon resonance nanosensors for selective atrazine detection.

    Science.gov (United States)

    Yılmaz, Erkut; Özgür, Erdoğan; Bereli, Nilay; Türkmen, Deniz; Denizli, Adil

    2017-04-01

    This study reports a surface plasmon resonance (SPR) based affinity sensor system with the use of molecular imprinted nanoparticles (plastic antibodies) to enhance the pesticide detection. Molecular imprinting based affinity sensor is prepared by the attachment of atrazine (chosen as model pesticide) imprinted nanoparticles onto the gold surface of SPR chip. Recognition element of the affinity sensor is polymerizable form of aspartic acid. The imprinted nanoparticles were characterized via FTIR and zeta-sizer measurements. SPR sensors are characterized with atomic force microscopy (AFM), scanning electron microscopy (SEM), Fourier transform infrared spectrophotometry (FTIR) and contact angle measurements. The imprinted nanoparticles showed more sensitivity to atrazine than the non-imprinted ones. Different concentrations of atrazine solutions are applied to SPR system to determine the adsorption kinetics. Langmuir adsorption model is found as the most suitable model for this affinity nanosensor system. In order to show the selectivity of the atrazine-imprinted nanoparticles, competitive adsorption of atrazine, simazine and amitrole is investigated. The results showed that the imprinted nanosensor has high selectivity and sensitivity for atrazine. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Effects of atrazine on growth and sex differentiation, in juveniles of the freshwater crayfish Cherax quadricarinatus.

    Science.gov (United States)

    Mac Loughlin, Camila; Canosa, Ivana S; Silveyra, Gabriela R; López Greco, Laura S; Rodríguez, Enrique M

    2016-09-01

    The effect of the herbicide atrazine was assayed in early juveniles of the redclaw crayfish Cherax quadricarinatus. Four cohorts of juveniles (a total of 280 animals) were exposed for 4 wk to each one of three atrazine concentrations (0.1, 0.5 and 2.5mg/L) or a control (0mg/L), from a commercial formulation having 90% of active principle. At the end of the exposure, no significant (p>0.05) differences in either mortality or molting were noted. However, the weight gain and the protein content of abdominal muscle decreased significantly (p<0.05) in the highest atrazine concentration as compared to control, indicating that atrazine acted as a relevant stressor, although at a concentration higher than those reported in the environment. Besides, the proportion of females increased progressively as the atrazine concentration increases, being significantly (p<0.05) higher than that of controls at the highest concentration assayed. Both macroscopic and histological analysis revealed a normal architecture of gonopores and gonads in both control and exposed animals. The obtained results strongly suggest that atrazine could be causing an endocrine disruption on the hormonal system responsible for the sexual differentiation of the studied species, increasing the proportion of female proportion without disturbing the gonad structure. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Enhanced biodegradation of atrazine by bacteria encapsulated in organically modified silica gels.

    Science.gov (United States)

    Benson, Joey J; Sakkos, Jonathan K; Radian, Adi; Wackett, Lawrence P; Aksan, Alptekin

    2018-01-15

    Biodegradation by cells encapsulated in silica gel is an economical and environmentally friendly method for the removal of toxic chemicals from the environment. In this work, recombinant E. coli expressing atrazine chlorohydrolase (AtzA) were encapsulated in organically modified silica (ORMOSIL) gels composed of TEOS, silica nanoparticles (SNPs), and either phenyltriethoxysilane (PTES) or methyltriethoxysilane (MTES). ORMOSIL gels adsorbed much higher amounts of atrazine than the hydrophilic TEOS gels. The highest amount of atrazine adsorbed by ORMOSIL gels was 48.91×10 -3 μmol/mlgel, compared to 8.71×10 -3 μmol/mlgel by the hydrophilic TEOS gels. Atrazine biodegradation rates were also higher in ORMOSIL gels than the TEOS gels, mainly due to co-localization of the hydrophobic substrate at high concentrations in close proximity of the encapsulated bacteria. A direct correlation between atrazine adsorption and biodegradation was observed unless biodegradation decreased due to severe phase separation. The optimized PTES and MTES gels had atrazine biodegradation rates of 0.041±0.003 and 0.047±0.004μmol/mlgel, respectively. These rates were approximately 80% higher than that measured in the TEOS gel. This study showed for the first time that optimized hydrophobic gel material design can be used to enhance both removal and biodegradation of hydrophobic chemicals. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Microbial changes linked to the accelerated degradation of the herbicide atrazine in a range of temperate soils.

    Science.gov (United States)

    Yale, R L; Sapp, M; Sinclair, C J; Moir, J W B

    2017-03-01

    Accelerated degradation is the increased breakdown of a pesticide upon its repeated application, which has consequences for the environmental fate of pesticides. The herbicide atrazine was repeatedly applied to soils previously untreated with s-triazines for >5 years. A single application of atrazine, at an agriculturally relevant concentration, was sufficient to induce its rapid dissipation. Soils, with a range of physico-chemical properties and agricultural histories, showed similar degradation kinetics, with the half-life of atrazine decreasing from an average of 25 days after the first application to degrading kinetics, which incorporated the exponential growth of atrazine-degrading organisms. Despite the similar rates of degradation, the repertoire of atrazine-degrading genes varied between soils. Only a small portion of the bacterial community had the capacity for atrazine degradation. Overall, the microbial community was not significantly affected by atrazine treatment. One soil, characterised by low pH, did not exhibit accelerated degradation, and atrazine-degrading genes were not detected. Neutralisation of this soil restored accelerated degradation and the atrazine-degrading genes became detectable. This illustrates the potential for accelerated degradation to manifest when conditions become favourable. Additionally, the occurrence of accelerated degradation under agriculturally relevant concentrations supports the consideration of the phenomena in environmental risk assessments.

  15. Atrazine removal from water by polycation-clay composites: effect of dissolved organic matter and comparison to activated carbon.

    Science.gov (United States)

    Zadaka, Dikla; Nir, Shlomo; Radian, Adi; Mishael, Yael G

    2009-02-01

    Atrazine removal from water by two polycations pre-adsorbed on montmorillonite was studied. Batch experiments demonstrated that the most suitable composite poly (4-vinylpyridine-co-styrene)-montmorillonite (PVP-co-S90%-mont.) removed 90-99% of atrazine (0.5-28 ppm) within 20-40 min at 0.367% w/w. Calculations employing Langmuir's equation could simulate and predict the kinetics and final extents of atrazine adsorption. Column filter experiments (columns 20x1.6 cm) which included 2g of the PVP-co-S90%-mont. composite mixed with excess sand removed 93-96% of atrazine (800 ppb) for the first 800 pore volumes, whereas the same amount of granular activated carbon (GAC) removed 83-75%. In the presence of dissolved organic matter (DOM; 3.7 ppm) the efficiency of the GAC filter to remove atrazine decreased significantly (68-52% removal), whereas the corresponding efficiency of the PVP-co-S90%-mont. filter was only slightly influenced by DOM. At lower atrazine concentration (7 ppb) the PVP-co-S90%-mont. filter reduced even after 3000 pore volumes the emerging atrazine concentration below 3 ppb (USEPA standard). In the case of the GAC filter the emerging atrazine concentration was between 2.4 and 5.3 microg/L even for the first 100 pore volumes. Thus, the PVP-co-S90%-mont. composite is a new efficient material for the removal of atrazine from water.

  16. Degradation of atrazine and several organophosphorus pesticides in oranges

    Energy Technology Data Exchange (ETDEWEB)

    Bouaid, A.; Martin-Esteban, A.; Fernandez, P.; Camara, C. [Madrid Univ., Madrid (Spain). Facultad de Ciencias Quimicas, Dept. de Quimica Analitica

    2001-02-01

    The degradation of atrazine and four organophosphorus pesticides (chloropyriphos, fenamiphos, methidathion and methyl-parathion) in oranges was studied. Oranges were immersed in a Milli-Q water solution spiked with 10 mg litre{sup -}1 of each pesticide for one day, allowing their adsorption on the orange peel. Then, the oranges were rinsed with Milli-Q water and left outdoors to expose them to natural ambient conditions for two weeks. In parallel, an aqueous solution containing 1 mg litre{sup -}1 of each pesticide was placed in a Pyrex flask, which was tightly closed, and exposed to the same ambient conditions. Both samples (orange peel and Milli-Q water) were analyzed periodically by gas chromatography coupled to a nitrogen phosphorus detector. The pesticide degradation in both samples could be described using a first-order degradation curve. Half-lives varied from 14.5 to more than 30 days in aqueous solution and from 2.3 to 4.1 days in oranges for organophosphorus pesticides, while those for atrazine were 3.1 days and 14.2 days, respectively. The presence of some organophosphorus degradation products in water samples after storage under the above conditions was confirmed by gas chromatography-mass spectrometry. [Italian] E' stata studiata la degradazione dell'atrazina e quattro pesticidi organofosforati (chlorpyriphos, fenamiphos, methidathion and methyl-parathion) nelle arance. Le arance sono state immerse, per un giorno, in una soluzione acquosa (Milli-Q) addizionata di 10 mg L di ciascun pesticida al fine di ottenerne l'assorbimento sulla biccia. Le arance sono state successivamente lavate con acqua Milli-Q e collocate all'esterno per esporle alle condizioni ambientali per due settimane. In parallelo si e' collocata, una soluzione acquosa contenente 1 mg L, in un matraccio di pirex chiuso ed esposto alle stesse condizioni ambientali. Entrambi i campioni (buccia d'arancia ed acqua Milli-Q) sono stati analizzati periodicamente

  17. 20 years of long-term atrazine monitoring in a shallow aquifer in western Germany.

    Science.gov (United States)

    Vonberg, David; Vanderborght, Jan; Cremer, Nils; Pütz, Thomas; Herbst, Michael; Vereecken, Harry

    2014-03-01

    Atrazine was banned in Germany in 1991 due to findings of atrazine concentrations in ground- and drinking waters exceeding threshold values. Monitoring of atrazine concentrations in the groundwater since then provides information about the resilience of the groundwater quality to changing agricultural practices. In this study, we present results of a monitoring campaign of atrazine concentrations in the Zwischenscholle aquifer. This phreatic aquifer is exposed to intensive agricultural land use and susceptible to contaminants due to a shallow water table. In total 60 observation wells (OWs) have been monitored since 1991, of which 15 are sampled monthly today. Descriptive statistics of monitoring data were derived using the "regression on order statistics" (ROS) data censoring approach, estimating values for nondetects. The monitoring data shows that even 20 years after the ban of atrazine, the groundwater concentrations of sampled OWs remain on a level close to the threshold value of 0.1 μg l(-1) without any considerable decrease. The spatial distribution of atrazine concentrations is highly heterogeneous with OWs exhibiting permanently concentrations above the regulatory threshold on the one hand and OWs were concentrations are mostly below the limit of quantification (LOQ) on the other hand. A deethylatrazine-to-atrazine ratio (DAR) was used to distinguish between diffuse - and point-source contamination, with a global mean value of 0.84 indicating mainly diffuse contamination. Principle Component Analysis (PCA) of the monitoring dataset demonstrated relationships between the metabolite desisopropylatrazine, which was found to be exclusively associated with the parent compound simazine but not with atrazine, and between deethylatrazine, atrazine, nitrate, and the specific electrical conductivity. These parameters indicate agricultural impacts on groundwater quality. The findings presented in this study point at the difficulty to estimate mean concentrations

  18. Detection and organization of atrazine-degrading genetic potential of seventeen bacterial isolates belonging to divergent taxa indicate a recent common origin of their catabolic functions

    DEFF Research Database (Denmark)

    El Azhari, Najoi

    2007-01-01

    A collection of 17 atrazine-degrading bacteria isolated from soils was studied to determine the composition of the atrazine-degrading genetic potential (i.e. trzN, trzD and atz) and the presence of IS1071. The characterization of seven new atrazine-degrading bacteria revealed for the first time...

  19. Characterization of atrazine binding to dissolved organic matter of soil under different types of land use.

    Science.gov (United States)

    Zhu, Long-Ji; Zhao, Yue; Chen, Yan-Ni; Cui, Hong-Yang; Wei, Yu-Quan; Liu, Hai-Long; Chen, Xiao-Meng; Wei, Zi-Min

    2018-01-01

    Atrazine is widely used in agriculture. In this study, dissolved organic matter (DOM) from soils under four types of land use (forest (F), meadow (M), cropland (C) and wetland (W)) was used to investigate the binding characteristics of atrazine. Fluorescence excitation-emission matrix-parallel factor (EEM-PARAFAC) analysis, two-dimensional correlation spectroscopy (2D-COS) and Stern-Volmer model were combined to explore the complexation between DOM and atrazine. The EEM-PARAFAC indicated that DOM from different sources had different structures, and humic-like components had more obvious quenching effects than protein-like components. The Stern-Volmer model combined with correlation analysis showed that log K values of PARAFAC components had a significant correlation with the humification of DOM, especially for C3 component, and they were all in the same order as follows: meadow soil (5.68)>wetland soil (5.44)>cropland soil (5.35)>forest soil (5.04). The 2D-COS further confirmed that humic-like components firstly combined with atrazine followed by protein-like components. These findings suggest that DOM components can significantly influence the bioavailability, mobility and migration of atrazine in different land uses. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. GnRH Protein Levels in Atrazine-Treated Axolotls (Ambystoma mexicanum

    Directory of Open Access Journals (Sweden)

    Sarah Leupen

    2008-01-01

    Full Text Available Atrazine is the most widely used agricultural herbicide in the United States and a known endocrine disruptor. In amphibians, it has been shown to cause gonadal malformations, feminization of males, behavioral changes, and immune suppression; however, its mechanism ofaction is unknown. We hypothesized that atrazine reduces the production of gonadotropin releasing hormone (GnRH in the hypothalamus. Axolotls (Ambystoma mexicanum were exposed to atrazine, 10-8 M ß-estradiol-3-benzoate, or no treatment and were sacrificed at 6, 8, and 10 months of age. GnRH neurons were labeled using immunocytochemistry, and labeled neurons were then counted using confocal microscopy. Although no significant difference wasfound in the total number of GnRH neurons, ectopic GnRH expression was seen in some brains. A significant negative correlation was found between presence of ectopic GnRH and number of normal GnRH neurons. Atrazine-treated animals were more likely than control or estrogentreated animals to have ectopic GnRH expression. The data implicate a central site of action of atrazine.

  1. Degradation and sorption of fipronil and atrazine in Latossols with organic residues from sugarcane crop

    Directory of Open Access Journals (Sweden)

    Raquel de Oliveira Silva

    2016-07-01

    Full Text Available ABSTRACT: Organic residues from sugarcane crop and processing (vinasse, boiler ash, cake filter, and straw are commonly applied or left on the soil to enhance its fertility. However, they can influence pesticide degradation and sorption. The objective of this study was to assess the effect of adding these organic residues on the degradation and sorption of fipronil and atrazine in two soils of the State of Mato Grosso do Sul, MS, Brazil. The degradation experiment was carried out with laboratory-incubated (40 days; 28°C; 70% field capacity soils (0-10cm. The batch equilibration method was used to determine sorption. Fipronil (half-life values of 15-105 days showed to be more persistent than atrazine (7-17 days. Vinasse application to the soil favored fipronil and atrazine degradation, whereas cake filter application decreased the degradation rates for both pesticides. Values for sorption coefficients (Kd were determined for fipronil (5.1-13.2mL g-1 and atrazine (0.5-1.5mL g-1. Only straw and cake filter residues enhanced fipronil sorption when added to the soil, whereas all sugarcane residues increased atrazine sorption.

  2. Watershed regressions for pesticides (warp) models for predicting atrazine concentrations in Corn Belt streams

    Science.gov (United States)

    Stone, Wesley W.; Gilliom, Robert J.

    2012-01-01

    Watershed Regressions for Pesticides (WARP) models, previously developed for atrazine at the national scale, are improved for application to the United States (U.S.) Corn Belt region by developing region-specific models that include watershed characteristics that are influential in predicting atrazine concentration statistics within the Corn Belt. WARP models for the Corn Belt (WARP-CB) were developed for annual maximum moving-average (14-, 21-, 30-, 60-, and 90-day durations) and annual 95th-percentile atrazine concentrations in streams of the Corn Belt region. The WARP-CB models accounted for 53 to 62% of the variability in the various concentration statistics among the model-development sites. Model predictions were within a factor of 5 of the observed concentration statistic for over 90% of the model-development sites. The WARP-CB residuals and uncertainty are lower than those of the National WARP model for the same sites. Although atrazine-use intensity is the most important explanatory variable in the National WARP models, it is not a significant variable in the WARP-CB models. The WARP-CB models provide improved predictions for Corn Belt streams draining watersheds with atrazine-use intensities of 17 kg/km2 of watershed area or greater.

  3. Atrazine Molecular Imprinted Polymers: Comparative Analysis by Far-Infrared and Ultraviolet Induced Polymerization

    Science.gov (United States)

    Chen, Jun; Bai, Lian-Yang; Liu, Kun-Feng; Liu, Run-Qiang; Zhang, Yu-Ping

    2014-01-01

    Atrazine molecular imprinted polymers (MIPs) were comparatively synthesized using identical polymer formulation by far-infrared (FIR) radiation and ultraviolet (UV)-induced polymerization, respectively. Equilibrium binding experiments were carried out with the prepared MIPs; the results showed that MIPuv possessed specific binding to atrazine compared with their MIPFIR radiation counterparts. Scatchard plot’s of both MIPs indicated that the affinities of the binding sites in MIPs are heterogeneous and can be approximated by two dissociation-constants corresponding to the high-and low-affinity binding sites. Moreover, several common pesticides including atrazine, cyromazine, metamitron, simazine, ametryn, terbutryn were tested to determine their specificity, similar imprinting factor (IF) and different selectivity index (SI) for both MIPs. Physical characterization of the polymers revealed that the different polymerization methods led to slight differences in polymer structures and performance by scanning electron microscope (SEM), Fourier transform infrared absorption (FT-IR), and mercury analyzer (MA). Finally, both MIPs were used as selective sorbents for solid phase extraction (SPE) of atrazine from lake water, followed by high performance liquid chromatography (HPLC) analysis. Compared with commercial C18 SPE sorbent (86.4%–94.8%), higher recoveries of atrazine in spiked lake water were obtained in the range of 90.1%–97.1% and 94.4%–101.9%, for both MIPs, respectively. PMID:24398982

  4. ATRAZINE ADSORPTION-DESORPTION BEHAVIOR IN DAREHASALUIE KAVAR CORN FIELD SOIL

    Directory of Open Access Journals (Sweden)

    M. Dehghani, S. Nasseri, S. Amin, K. Naddafi, M. Yunesian, M. Taghavi and N. Maleki

    2005-10-01

    Full Text Available Adsorption desorption behaviors of widely applied atrazine soil were studied, employing a batch technique as a case study in Darehasaluie Kavar corn field in Fars Province in 2005. Samples were collected into 0 to 20 cm soil depth, where was cultivated under a crop rotation (corn-wheat during the past 10 years. Sorption kinetics exhibited two phenomena: an immediate rapid sorption (1.31 µg/g soil after 12 hours followed by a slow sorption process (1.37 µg/g soil after 24 hours. Desorption behavior of atrazine was similar to its adsorption, but at a very slower rate. Atrazine desorption efficiencies were much less effective and incomplete even after a long equilibration time (only 9.16% after 96 hours. The adsorption-desorption rate for most of the time was positively related to the amount of applied atrazine and the time required for equilibration (P<0.01. Desorption data exhibited hysteresis phenomena. Atrazine adsorption data described well according to Freundlich (r2=0.95, Langmuir (r2=0.82 and Temkin (r2=0.84 isotherms. However, the fit to Freundlich adsorption model in a non linear form (1/n <1 was closer than the others. Desorption isotherm could be well described by the Temkin (r2=0.96 and Freundlich (r2=0.92 isotherms, but the fit to Temkin model was closer than that of Freundlich.

  5. Environmentally realistic exposure to the herbicide atrazine alters some sexually selected traits in male guppies.

    Directory of Open Access Journals (Sweden)

    Kausalya Shenoy

    Full Text Available Male mating signals, including ornaments and courtship displays, and other sexually selected traits, like male-male aggression, are largely controlled by sex hormones. Environmental pollutants, notably endocrine disrupting compounds, can interfere with the proper functioning of hormones, thereby impacting the expression of hormonally regulated traits. Atrazine, one of the most widely used herbicides, can alter sex hormone levels in exposed animals. I tested the effects of environmentally relevant atrazine exposures on mating signals and behaviors in male guppies, a sexually dimorphic freshwater fish. Prolonged atrazine exposure reduced the expression of two honest signals: the area of orange spots (ornaments and the number of courtship displays performed. Atrazine exposure also reduced aggression towards competing males in the context of mate competition. In the wild, exposure levels vary among individuals because of differential distribution of the pollutants across habitats; hence, differently impacted males often compete for the same mates. Disrupted mating signals can reduce reproductive success as females avoid mating with perceptibly suboptimal males. Less aggressive males are at a competitive disadvantage and lose access to females. This study highlights the effects of atrazine on ecologically relevant mating signals and behaviors in exposed wildlife. Altered reproductive traits have important implications for population dynamics, evolutionary patterns, and conservation of wildlife species.

  6. Assessment of bacterial biodetoxification of herbicide atrazine using Aliivibrio fischeri cytotoxicity assay with prolonged contact time.

    Science.gov (United States)

    Háhn, Judit; Szoboszlay, Sándor; Tóth, Gergő; Kriszt, Balázs

    2017-07-01

    In our study, we determined and compared the atrazine-biodetoxification ability of 41 bacterial strains and 21 consortia created of those with over 50% degradation rate in pure cultures. Biodegradation capacity was measured with GC-MS. Detoxification was assessed based on the cytotoxic effect of end-products to Aliivibrio fischeri in chronic bioluminescence inhibition assay with 25 h contact time. Chronic A. fischeri assay adapted to a microplate, which is suitable for examine numerous residues simultaneously, also appeared to be significantly more sensitive to atrazine compared to the standard acute (30 min) test. Due to its sensitivity, the chronic assay could be a valuable tool to provide a more comprehensive view of the ecological risks of atrazine and other chemicals. Thirteen strains were able to degrade more than 50% of 50 ppm atrazine. Four of these belong to Rhodococcus aetherivorans, R. qingshengii, Serratia fonticola and Olivibacter oleidegradans which species' atrazine degrading ability has never been reported before. Four consortia degrading ability was more effective than that of the creating individual strains; moreover, their residues did not show cytotoxic effects to A. fischeri. However, in several cases, the degradation products of sole strains and consortia resulted in significant bioluminescence inhibition. Thus high biodegradation (>90%) does not certainly mean the reduction or cessation of toxicity highlighting the importance of the evaluation of biological effects of degradation residues to improve the efficiency and abate the ecological risks of bioremediation techniques.

  7. Atrazine Molecular Imprinted Polymers: Comparative Analysis by Far-Infrared and Ultraviolet Induced Polymerization

    Directory of Open Access Journals (Sweden)

    Jun Chen

    2014-01-01

    Full Text Available Atrazine molecular imprinted polymers (MIPs were comparatively synthesized using identical polymer formulation by far-infrared (FIR radiation and ultraviolet (UV-induced polymerization, respectively. Equilibrium binding experiments were carried out with the prepared MIPs; the results showed that MIPuv possessed specific binding to atrazine compared with their MIPFIR radiation counterparts. Scatchard plot’s of both MIPs indicated that the affinities of the binding sites in MIPs are heterogeneous and can be approximated by two dissociation-constants corresponding to the high- and low-affinity binding sites. Moreover, several common pesticides including atrazine, cyromazine, metamitron, simazine, ametryn, terbutryn were tested to determine their specificity, similar imprinting factor (IF and different selectivity index (SI for both MIPs. Physical characterization of the polymers revealed that the different polymerization methods led to slight differences in polymer structures and performance by scanning electron microscope (SEM, Fourier transform infrared absorption (FT-IR, and mercury analyzer (MA. Finally, both MIPs were used as selective sorbents for solid phase extraction (SPE of atrazine from lake water, followed by high performance liquid chromatography (HPLC analysis. Compared with commercial C18 SPE sorbent (86.4%–94.8%, higher recoveries of atrazine in spiked lake water were obtained in the range of 90.1%–97.1% and 94.4%–101.9%, for both MIPs, respectively.

  8. Understanding the Effects of Atrazine on Steroidogenesis in rat granulosa and H295R adrenal cortical carcinoma cells

    Science.gov (United States)

    Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) was introduced in the 1950s as a broad spectrum herbicide, and remains one of the most widely used herbicides in the United States. Several studies have suggested that atrazine modifies steroidogenesis and may disrupt r...

  9. Fate of the herbicide 14C-atrazine during sewage treatment on a lab-scale bioreactor

    Directory of Open Access Journals (Sweden)

    Jaime L. M. Oliveira

    2013-08-01

    Full Text Available Atrazine (2-chloro-4-(ethylamino-6-(isopropylamino-s-triazine is a persistent herbicide used on some crops and it has been found both in ground and surface water and drainage systems. This work studied the behaviour of atrazine during a sewage treatment process by activated sludge. The process was conducted on a laboratory scale using an under fed-batch system with a hydraulic retention time of 24 hours. After this period, the raw sewage (with atrazine was changed and another batch was begun (the sludge age was 7 days old. Radiolabel molecules (14C-atrazine were used for to trace their fate and to measure to the 14C-CO2 and the residues of atrazine were analysed by HPLC/UV. Initially about 50% of radioactivity was sorbed by the settled sludge but it was desorbed with successive additions of raw sewage without atrazine. The final balance of radioactivity showed that 98% of the atrazine was released into the treated effluent, probably without any biodegradation. Therefore, other organic micropollutants with similar characteristics to atrazine may behave a similar way.

  10. Atrazine Contamination and Potential Health Effects on Freshwater Mussel Uniandra contradens Living in Agricultural Catchment at Nan Province, Thailand

    Directory of Open Access Journals (Sweden)

    Tongchai Thitiphuree

    2013-01-01

    Full Text Available Seasonal cultivation in northern part of Thailand leads to widely uses of agrochemicals especially atrazine herbicide. To examine whether an intensive use of atrazine could lead to contamination in aquatic environment, sediment and water were collected from an agricultural catchment in Nan Province during 2010-2011 and subjected to analysis for atrazine by GC-MS. The results showed that detectable levels of atrazine were found in water (0.16 µg/ml and sediment (0.23 µg/g of the catchment. To monitor potential effects of atrazine on aquatic animals, a freshwater mussel Uniandra contradens was used as a sentinel species for bioaccumulation and potential health effects. Mussels collected from the catchment during 2010-2011 were subjected to analysis for atrazine residue in tissue and condition factor based on body weight and shell length. The results showed that detectable levels of atrazine were found in mussel tissue with the highest level (8.40  2.06 ng/g in late wet season when runoff from heavy rain was evidenced. Condition factor, an indicative of overall health, showed a significant negative correlation with atrazine residue in the tissue. This information could be used as part of the monitoring program for herbicide contamination and potential health effects in agricultural environment.

  11. Biomarker analysis of American toad (Anaxyrus americanus) and grey tree frog (Hyla versicolor) tadpoles following exposure to atrazine.

    Science.gov (United States)

    The objective of the current study was to use a biomarker-based approach to investigate the influence of atrazine exposure on American toad (Anaxyrus americanus) and grey tree frog (Hyla versicolor) tadpoles. Atrazine is one of the most frequently detected herbicides in environme...

  12. Assessing atrazine-induced toxicities in Bufo bufo gargarizans Cantor.

    Science.gov (United States)

    Sai, Linlin; Wu, Qingbo; Qu, Binpeng; Bo, Cunxiang; Yu, Gongchang; Jia, Qiang; Xie, Lin; Li, Yuezhong; Guo, Qiming; Ng, Jack C; Peng, Cheng

    2015-02-01

    Atrazine (AZ), a widely used herbicide has drawn attentions for its potential impacts on amphibians. This study aims to investigate the toxicity of AZ in Bufo bufo gargarizans Cantor (B. bufo gargarizans), a species of toad commonly found in China and countries in East Asia. We treated tadpoles with 0.1, 1, 10 and 100 μg/L AZ for 85 days and examined related parameters. The results showed that the mortality of the toads in the treatment group increased dramatically in a U-shaped dose-response relationship. The hindlimb extension and metamorphosis rate of the toads were significantly inhibited by AZ at 10 and 100 μg/L. Under the same condition, there were significant progressive changes in the testicular structures. Moreover, we found that AZ has no significant effects on growth, sex ratios, gonadal morphology, forelimb emergence and histology in the ovaries. Our results support the idea that environmental contaminants including AZ may be relevant to global amphibian decline.

  13. Agro-waste biosorbents: Effect of physico-chemical properties on atrazine and imidacloprid sorption.

    Science.gov (United States)

    Mandal, Abhishek; Singh, Neera; Nain, Lata

    2017-09-02

    Low cost agro-waste biosorbents namely eucalyptus bark (EB), corn cob (CC), bamboo chips (BC), rice straw (RS) and rice husk (RH) were characterized and used to study atrazine and imidacloprid sorption. Adsorption studies suggested that biosorbents greatly varied in their pesticide sorption behaviour. The EB was the best biosorbent to sorb both atrazine and imidacloprid with KF values of 169.9 and 85.71, respectively. The adsorption isotherm were nonlinear in nature with slope (1/n) values imidacloprid sorption parameter [KF.(1/n)] with the physicochemical properties of the biosorbents suggested that atrazine adsorption correlated significantly to the aromaticity, polarity, surface area, fractal dimension, lacunarity and relative C-O band intensity parameters of biosorbents. Probably, both physisorption and electrostatic interactions were responsible for the pesticide sorption. The eucalyptus bark can be exploited as low cost adsorbent for the removal of these pesticides as well as a component of on-farm biopurification systems.

  14. Effect of liquid cow manure on andisol properties and atrazine adsorption.

    Science.gov (United States)

    Briceño, Gabriela; Demanet, Rolando; de la Luz Mora, María; Palma, Graciela

    2008-01-01

    Application of animal manure amendments to agricultural soils is a common practice to improve soil fertility through the addition of essential plant nutrients. This practice may increase the potential for atrazine (2-chloro-4-ethylamino-6-isopropylamino-1, 3, 5-triazine) leaching due to competition for adsorption sites between the pesticide and dissolved organic carbon (DOC) added through manure. We evaluated the influence of liquid cow manure (LCM) application on soil properties, atrazine adsorption, and the physicochemical controlling mechanisms in an Andisol. The LCM was applied at rates equivalent to 0, 100,000, 200,000, and 300,000 L ha(-1), resulting in treatments S-0, S-100, S-200, and S-300, respectively. The LCM application increased DOC and pH of the soils immediately on addition, but pH returned to S-0 values 30 d after application. The LCM application did not modify atrazine adsorption with the two lowest application rates (S-100 and S-200), but atrazine adsorption was decreased in S-300 (K(f) = 0.96) compared with the control (S-0) (K(f) = 1.19), possibly due to the competitive adsorption of DOC with the pesticide. The Fourier-transformed infrared analysis showed that LCM increased aliphaticity and presence of N-containing groups and polysaccharide-like groups in amended soils; however, these properties did not modify the atrazine interaction in the studied amended soils. Interestingly the addition of DOC to soil at the high application rate (S-300) reduced atrazine adsorption in this rich OM Andisol despite the LCM not raising the concentration of stable organic matter. The application of high rates of liquid manure containing DOC incurs an increased risk of pesticide leaching.

  15. Potencial alelopático de 2-benzoxazolinona (boa e sua interação com atrazine no crescimento de plantas Allelopathic potential of 2-benzoxazolinone (boa and its interactions with atrazine on lant growth

    Directory of Open Access Journals (Sweden)

    Itamar F. Souza

    1994-01-01

    Full Text Available Dois experimentos de laboratório foram conduzidos na Universidade de South Dakota, Vemillion, SD, EUA, em 1990, para determinar os efeitos do ácido hidroxâmico benzoxazolinona (BOA, do herbicida atrazine e de suas misturas sobre o crescimento e teor de clorofila de lentilha dágua (Lemna minor. BOA na concentração de 0,5 mM foi aplicado em combinação com atrazine a 0,001 e 0,005 mM em caixas plásticas com 24 células de 2,5 ml, contendo 3 frondes de lentilha dágua em solução nutritiva. BOA e atrazine, aplicados isoladamente, inibiram o número, o peso sêco e o teor de clorofila. Atrazine apresentou uma maior ação inibitória que BOA. A combinação BOA (0,05 mM e atrazine à 0,001 mM foi antagonística. A inibição induzida pelo atrazine a 0,001 mM foi, em parte, neutralizada, porém, com a dose 0,005 mM a sua ação inibitória não foi alterada.Two laboratoy experiments were carried out at the University of South Dakota, Vermillion, SD, USA, in 1990, to determine the effects of hydroxamic acid benzoxazolinone (BOA, the herbicide atrazine, and a mixture there of on duckweed growth and its chlorophyll content. BOA at 0.5 mM concentration was applied in combination with atrazine at 0.001 and 0.005 mM in a 2.5 ml cell tissue cluster dish containing three fronds of duckweed in nutrient solution. Single applications of BOA and atrazine inhibited duckweed frond number, frond dry weight, and its chlorophyll content. Atrazine showed stronger inbibition effect than BOA. The combination BOA and atrazine at 0.001 mM was antagonistic where the inhibition induced by the herbicide was counteracted. Unlike atrazine at 0.00I mM, BOA added to atrazine at 0,005 mM did not counteract the inhibitio caused by the herbicide.

  16. Method for Estimating Annual Atrazine Use for Counties in the Conterminous United States, 1992-2007

    Science.gov (United States)

    Thelin, Gail P.; Stone, Wesley W.

    2010-01-01

    A method was developed to estimate annual atrazine use during 1992 to 2007 on sixteen crops and four agricultural land uses. For each year, atrazine use was estimated for all counties in the conterminous United States (except California) by combining (1) proprietary data from the Doane Marketing Research-Kynetec (DMRK) AgroTrak database on the mass of atrazine applied to agricultural crops, (2) county harvested crop acreage, by county, from the 1992, 1997, 2002, and 2007 Censuses of Agriculture, and (3) annual harvested crop acreage from National Agriculture Statistics Service (NASS) for non-Census years. DMRK estimates of pesticide use on individual crops were derived from surveys of major field crops and selected specialty crops in multicounty areas referred to as Crop Reporting Districts (CRD). The CRD-level atrazine-use estimates were disaggregated to obtain county-level application rates by dividing the mass (pounds) of pesticides applied to a crop by the acreage of that crop in the CRD to yield a rate per harvested acre. When atrazine-use estimates were not available for a CRD, crop, or year, an estimated rate was developed following a hierarchy of decision rules that checked first for the availability of a crop application rate from surveyed atrazine application rate(s) for adjacent CRDs for a specific year, and second, the rates from surveyed CRDs within for U.S. Department of Agriculture Farm Production Regions for a specific year or multiple years. The estimation method applied linear interpolation to estimate crop acreage for years when harvested acres for a crop and county were not reported in either the Census of Agriculture or the NASS database, but were reported by these data sources for other years for that crop and county. Data for atrazine use for the counties in California was obtained from farmers' reports of pesticide use collected and published by the California Department of Pesticide Regulation-Pesticide Use Reporting (DPR-PUR) because these

  17. Atrazine induced epigenetic transgenerational inheritance of disease, lean phenotype and sperm epimutation pathology biomarkers.

    Science.gov (United States)

    McBirney, Margaux; King, Stephanie E; Pappalardo, Michelle; Houser, Elizabeth; Unkefer, Margaret; Nilsson, Eric; Sadler-Riggleman, Ingrid; Beck, Daniel; Winchester, Paul; Skinner, Michael K

    2017-01-01

    Ancestral environmental exposures to a variety of environmental toxicants and other factors have been shown to promote the epigenetic transgenerational inheritance of adult onset disease. The current study examined the potential transgenerational actions of the herbicide atrazine. Atrazine is one of the most commonly used herbicides in the agricultural industry, in particular with corn and soy crops. Outbred gestating female rats were transiently exposed to a vehicle control or atrazine. The F1 generation offspring were bred to generate the F2 generation and then the F2 generation bred to generate the F3 generation. The F1, F2 and F3 generation control and atrazine lineage rats were aged and various pathologies investigated. The male sperm were collected to investigate DNA methylation differences between the control and atrazine lineage sperm. The F1 generation offspring (directly exposed as a fetus) did not develop disease, but weighed less compared to controls. The F2 generation (grand-offspring) was found to have increased frequency of testis disease and mammary tumors in males and females, early onset puberty in males, and decreased body weight in females compared to controls. The transgenerational F3 generation rats were found to have increased frequency of testis disease, early onset puberty in females, behavioral alterations (motor hyperactivity) and a lean phenotype in males and females. The frequency of multiple diseases was significantly higher in the transgenerational F3 generation atrazine lineage males and females. The transgenerational transmission of disease requires germline (egg or sperm) epigenetic alterations. The sperm differential DNA methylation regions (DMRs), termed epimutations, induced by atrazine were identified in the F1, F2 and F3 generations. Gene associations with the DMRs were identified. For the transgenerational F3 generation sperm, unique sets of DMRs (epimutations) were found to be associated with the lean phenotype or testis

  18. Analysis list: Pc [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pc Adult,Cell line,Embryo + dm3 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/targ...et/Pc.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Pc.5.tsv http://dbarchive.biosciencedbc.jp.../kyushu-u/dm3/target/Pc.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Pc.Adult.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/dm3/colo/Pc.Cell_line.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/dm3/colo/Pc.Embryo.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Adult.gml,http://dbarchive.bioscience

  19. SI PC104 Performance Test Report

    Energy Technology Data Exchange (ETDEWEB)

    Montelongo, S

    2005-12-16

    The Spectral Instruments (SI) PC104 systems associated with the SI-1000 CCD camera exhibited intermittent power problems during setup, test and operations which called for further evaluation and testing. The SI PC104 System is the interface between the SI-1000 CCD camera and its associated Diagnostic Controller (DC). As such, the SI PC104 must be a reliable, robust system capable of providing consistent performance in various configurations and operating conditions. This SI PC104 system consists of a stackable set of modules designed to meet the PC104+ Industry Standard. The SI PC104 System consists of a CPU module, SI Camera card, Media converter card, Video card and a I/O module. The root cause of power problems was identified as failing solder joints at the LEMO power connector attached to the SI Camera Card. The recommended solution was to provide power to the PC104 system via a PC104+ power supply module configured into the PC104 stack instead of thru the LEMO power connector. Test plans (2) were developed to test SI PC104 performance and identify any outstanding issues noted during extended operations. Test Plan 1 included performance and image acquisition tests. Test Plan 2 verified performance after implementing recommendations. Test Plan 2 also included verifying integrity of system files and driver installation after bootup. Each test plan was implemented to fully test against each set of problems noted. Test Plan presentations and Test Plan results are attached as appendices. Anticipated test results will show successful operation and reliable performance of the SI PC104 system receiving its power via a PC104 power supply module. A SI PC104 Usage Recommendation Memo will be sent out to the SI PC104 User Community. Recommendation memo(s) are attached as appendices.

  20. Data acquisition techniques using PC

    CERN Document Server

    Austerlitz, Howard

    1991-01-01

    Data Acquisition Techniques Using Personal Computers contains all the information required by a technical professional (engineer, scientist, technician) to implement a PC-based acquisition system. Including both basic tutorial information as well as some advanced topics, this work is suitable as a reference book for engineers or as a supplemental text for engineering students. It gives the reader enough understanding of the topics to implement a data acquisition system based on commercial products. A reader can alternatively learn how to custom build hardware or write his or her own software.

  1. The possible role of hydroxylation in the detoxification of atrazine in mature vetiver (Chrysopogon zizanioides Nash) grown in hydroponics.

    Science.gov (United States)

    Marcacci, Sylvie; Raventon, Muriel; Ravanel, Patrick; Schwitzguébel, Jean-Paul

    2005-01-01

    The resistance mechanism of vetiver (Chrysopogon zizanioides) to atrazine was investigated to evaluate its potential for phytoremediation of environment contaminated with the herbicide. Plants known to metabolise atrazine rely on hydroxylation mediated by benzoxazinones, conjugation catalyzed by glutathione-S-transferases and dealkylation probably mediated by cytochromes P450. All three possibilities were explored in mature vetiver grown in hydroponics during this research project. Here we report on the chemical role of benzoxazinones in the transformation of atrazine. Fresh vetiver roots and leaves were cut to extract and study their content in benzoxazinones known to hydroxylate atrazine, such as 2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one (DIBOA), 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA) and their mono- and di-glucosylated forms. Identification of benzoxazinones was performed by thin layer chromatography (TLC) and comparison of retention factors (Rf) and UV spectra with standards: although some products exhibited the same Rf as standards, UV spectra were different. Furthermore, in vitro hydroxylation of atrazine could not be detected in the presence of vetiver extracts. Finally, vetiver organs exposed to [14C]-atrazine did not produce any significant amount of hydroxylated products, such as hydroxyatrazine (HATR), hydroxy-deethylatrazine (HDEA), and hydroxy-deisopropylatrazine (HDIA). Altogether, these metabolic features suggest that hydroxylation was not a major metabolic pathway of atrazine in vetiver.

  2. Simultaneous removal of atrazine and copper using polyacrylic acid-functionalized magnetic ordered mesoporous carbon from water: adsorption mechanism

    Science.gov (United States)

    Zhou, Yaoyu; Zhang, Fengfeng; Tang, Lin; Zhang, Jiachao; Zeng, Guangming; Luo, Lin; Liu, Yuanyuan; Wang, Pei; Peng, Bo; Liu, Xiaocheng

    2017-03-01

    Highly efficient simultaneous removal of atrazine and Cu(II) was accomplished using synthesized polyacrylic acid-functionalized magnetic ordered mesoporous carbon (P-MMC) as compared to magnetic ordered mesoporous carbon (MMC) and ordered mesoporous carbon (OMC). The mutual effects and interactive mechanism of their adsorption onto P-MMC were investigated systematically by binary, preloading and thermodynamic adsorption procedures. In both binary and preloading systems, the adsorption of atrazine was inhibited to some extent by the presence of Cu(II) because of selective recognition and direct competition, but the presence of atrazine had negligible effect on Cu(II) desorption. With the coexistence of humic acid (0-20 mg L-1), both atrazine and Cu(II) sorption increased slightly in sole and binary systems. With the concentration of coexisting NaCl increasing from 0 to 100 mM, the adsorption capacity for Cu(II) slightly decreased, but as for atrazine adsorption, it decreased at first, and then increased slightly in sole and binary systems. P-MMC was applied to treat real environmental samples, and the sorption capacities for atrazine and Cu(II) in real samples were all more than 91.47% and 96.43% of those in lab ultrapure water, respectively. Finally, comprehensively considering the relatively good renewability and the superior behavior in the application to real water samples, P-MMC has potential in removal of atrazine, Cu(II) and possibly other persistent organic pollutants from wastewater.

  3. Effects of two ecological earthworm species on atrazine degradation performance and bacterial community structure in red soil.

    Science.gov (United States)

    Lin, Zhong; Zhen, Zhen; Ren, Lei; Yang, Jiewen; Luo, Chunling; Zhong, Laiyuan; Hu, Hanqiao; Liang, Yanqiu; Li, Yongtao; Zhang, Dayi

    2017-12-29

    Vermicomposting is an effective and environmentally friendly approach for eliminating soil organic contamination. Atrazine is one of the most commonly applied triazinic herbicides and frequently detected in agricultural soils. This study investigated the roles and mechanisms of two earthworm species (epigeic Eisenia foetida and endogeic Amynthas robustus) in microbial degradation of atrazine. Both earthworms accelerated atrazine degradation performance from 39.0% in sterile soils to 94.9%-95.7%, via neutralizing soil pH, consuming soil humus, altering bacterial community structure, enriching indigenous atrazine degraders and excreting the intestinal atrazine-degrading bacteria. Rhodoplanes and Kaistobacter were identified as soil indigenous degraders for atrazine mineralization and stimulated by both earthworm species. A. robustus excreted the intestinal Cupriavidus and Pseudomonas, whereas Flavobacterium was released by E. foetida. This study provides a comprehensive understanding of the distinct effects of two earthworm species on soil microbial community and atrazine degradation, offering technical supports to apply vermicomposting in effective soil bioremediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Probability of detecting atrazine/desethyl-atrazine and elevated concentrations of nitrate plus nitrate as nitrogen in ground water in the Idaho part of the western Snake River Plain

    Science.gov (United States)

    Donato, Mary M.

    2000-01-01

    As ground water continues to provide an ever-growing proportion of Idaho?s drinking water, concerns about the quality of that resource are increasing. Pesticides (most commonly, atrazine/desethyl-atrazine, hereafter referred to as atrazine) and nitrite plus nitrate as nitrogen (hereafter referred to as nitrate) have been detected in many aquifers in the State. To provide a sound hydrogeologic basis for atrazine and nitrate management in southern Idaho—the largest region of land and water use in the State—the U.S. Geological Survey produced maps showing the probability of detecting these contaminants in ground water in the upper Snake River Basin (published in a 1998 report) and the western Snake River Plain (published in this report). The atrazine probability map for the western Snake River Plain was constructed by overlaying ground-water quality data with hydrogeologic and anthropogenic data in a geographic information system (GIS). A data set was produced in which each well had corresponding information on land use, geology, precipitation, soil characteristics, regional depth to ground water, well depth, water level, and atrazine use. These data were analyzed by logistic regression using a statistical software package. Several preliminary multivariate models were developed and those that best predicted the detection of atrazine were selected. The multivariate models then were entered into a GIS and the probability maps were produced. Land use, precipitation, soil hydrologic group, and well depth were significantly correlated with atrazine detections in the western Snake River Plain. These variables also were important in the 1998 probability study of the upper Snake River Basin. The effectiveness of the probability models for atrazine might be improved if more detailed data were available for atrazine application. A preliminary atrazine probability map for the entire Snake River Plain in Idaho, based on a data set representing that region, also was produced

  5. Evaluation of the agronomic performance of atrazine-tolerant transgenic japonica rice parental lines for utilization in hybrid seed production.

    Directory of Open Access Journals (Sweden)

    Luhua Zhang

    Full Text Available Currently, the purity of hybrid seed is a crucial limiting factor when developing hybrid japonica rice (Oryza sativa L.. To chemically control hybrid seed purity, we transferred an improved atrazine chlorohydrolase gene (atzA from Pseudomonas ADP into hybrid japonica parental lines (two maintainers, one restorer, and Nipponbare, by using Agrobacterium-mediated transformation. We subsequently selected several transgenic lines from each genotype by using PCR, RT-PCR, and germination analysis. In the presence of the investigated atrazine concentrations, particularly 150 µM atrazine, almost all of the transgenic lines produced significantly larger seedlings, with similar or higher germination percentages, than did the respective controls. Although the seedlings of transgenic lines were taller and gained more root biomass compared to the respective control plants, their growth was nevertheless inhibited by atrazine treatment compared to that without treatment. When grown in soil containing 2 mg/kg or 5 mg/kg atrazine, the transgenic lines were taller, and had higher total chlorophyll contents than did the respective controls; moreover, three of the strongest transgenic lines completely recovered after 45 days of growth. After treatment with 2 mg/kg or 5 mg/kg of atrazine, the atrazine residue remaining in the soil was 2.9-7.0% or 0.8-8.7% respectively, for transgenic lines, and 44.0-59.2% or 28.1-30.8%, respectively, for control plants. Spraying plants at the vegetative growth stage with 0.15% atrazine effectively killed control plants, but not transgenic lines. Our results indicate that transgenic atzA rice plants show tolerance to atrazine, and may be used as parental lines in future hybrid seed production.

  6. Atrazine Triggers DNA Damage Response and Induces DNA Double-Strand Breaks in MCF-10A Cells

    Directory of Open Access Journals (Sweden)

    Peixin Huang

    2015-06-01

    Full Text Available Atrazine, a pre-emergent herbicide in the chloro-s-triazine family, has been widely used in crop lands and often detected in agriculture watersheds, which is considered as a potential threat to human health. Although atrazine and its metabolites showed an elevated incidence of mammary tumors in female Sprague–Dawley (SD rats, no molecular evidence was found relevant to its carcinogenesis in humans. This study aims to determine whether atrazine could induce the expression of DNA damage response-related proteins in normal human breast epithelial cells (MCF-10A and to examine the cytotoxicity of atrazine at a molecular level. Our results indicate that a short-term exposure of MCF-10A to an environmentally-detectable concentration of atrazine (0.1 µg/mL significantly increased the expression of tumor necrosis factor receptor-1 (TNFR1 and phosphorylated Rad17 in the cells. Atrazine treatment increased H2AX phosphorylation (γH2AX and the formation of γH2AX foci in the nuclei of MCF-10A cells. Atrazine also sequentially elevated DNA damage checkpoint proteins of ATM- and RAD3-related (ATR, ATRIP and phospho-Chk1, suggesting that atrazine could induce DNA double-strand breaks and trigger the DNA damage response ATR-Chk1 pathway in MCF-10A cells. Further investigations are needed to determine whether atrazine-triggered DNA double-strand breaks and DNA damage response ATR-Chk1 pathway occur in vivo.

  7. Environmental levels of atrazine and its degradation products impair survival skills and growth of red drum larvae.

    Science.gov (United States)

    del Carmen Alvarez, María; Fuiman, Lee A

    2005-09-10

    Red drum larvae (Sciaenops ocellatus) were exposed to environmentally realistic and sublethal levels of the herbicide atrazine (2-chloro-4-ethylamin-6-isopropylamino-S-triazine) to evaluate its effects on ecologically critical traits: growth, behavior, survival potential, and resting respiration rate. Settlement size larvae (7 mm total length) were given an acute exposure of atrazine at 0, 40, and 80 microg l(-1) for 4 days. Tests of 96 h survival confirmed that these naturally occurring concentrations were sublethal for red drum larvae. Growth, routine swimming, antipredator responses to artificial and actual predators, and resting respiration rate were monitored 1 and 3 days after onset of exposure. Atrazine exposure significantly reduced growth rate. Atrazine-exposed larvae also exhibited significantly higher routine swimming speeds, swam in more convoluted paths, and were hyperactive. Responses to artificial and actual predators were not affected by atrazine exposure nor were resting respiration rates. The higher rate of travel (86% higher in atrazine-treated larvae) resulted in higher predicted encounter rates with prey (up to 71%) and slow moving predators (up to 63%). However, hyperactivity and faster active swimming speeds of exposed larvae indicated that naturally occurring sublethal levels of atrazine will result in an elevated rate of energy utilization (doubling the total metabolic rate), which is likely to increase the risk of death by starvation. Moreover, atrazine effects on growth will prolong the larval period, which could reduce the juvenile population by as much as 24%. We conclude that environmentally realistic levels of atrazine induce behavioral and physiological effects on fish larvae that would compromise their survival expectations.

  8. Microscopic examination on cytological changes in Allium cepa and shift in phytoplankton population at different doses of Atrazine

    Science.gov (United States)

    Ghosh, Nabarun; Finger, Kristen; Usnick, Samantha; Rogers, William J.; Das, A. B.; Smith, Don W.

    2010-06-01

    Atrazine is a wide-range herbicide. For over 50 years, atrazine has been used as a selective broadleaf herbicide in many capacities, from pre-plant to pre-emergence to post-emergence, depending on the crop and application. Currently, 96% of all atrazine used is for commercial applications in fields for the control of broadleaf and grassy weeds in crops such as sorghum, corn, sugarcane, pineapple and for the control of undesirable weeds in rangeland. Many panhandle wells have also detected atrazine in samples taken. The concern for the public is the long-term effect of atrazine with its increasing popularity, and the impact on public health. We investigated the effect of different concentrations of atrazine on Allium cepa (onion), a standard plant test system. We established a control with the Allium bulbs grown on hydroponics culture. Varying concentrations of atrazine was used on the standard plant test system, Allium cepa grown hydroponically. The mitotic indices varied and with higher doses, we observed various chromosomal abnormalities including sticky bridges, early and late separations, and lag chromosomes with higher doses of treatments. In the second part of the experiment, 0.1ppb, 1ppb, 10ppb, and 100ppb concentrations of atrazine were applied to established phytoplankton cultures from the Lake Tanglewood, Texas. Study with a Sedgwick-Rafter counter, a BX-40 Olympus microscope with DP-70 camera revealed a gradual shift in the phytoplankton community from obligatory to facultative autotroph and finally to a parasitic planktonic community. This explains the periodic fish kill in the lakes after applications of atrazine in crop fields.

  9. Effects of nutrient pre-exposure on atrazine toxicity to Vallisneria americana Michx. (wild celery).

    Science.gov (United States)

    Dantin, Darrin D; Boustany, Ronald G; Lewis, Michael A; Jordan, Stephen J; Moss, Rebecca F; Michot, Thomas C

    2010-04-01

    Accelerated eutrophication is common to many freshwater and marine environments and often co-occurs with the presence of anthropogenic chemicals. However, the toxic effects of common chemical stressors such as herbicides in the presence of elevated nutrients are not well understood for most aquatic flora, particularly vascular species. To provide insight, field-collected Vallisneria americana Michx. (wild celery) were sequentially exposed to three nutrient concentrations for 3 months and then to nominal 11 and 110 microg L(-1) atrazine for 96 h. Nutrient concentrations (combined NH(4)(+), NO(2)(-), NO(3)(-), PO(4)(-)) were based on ambient concentrations in the St. Johns River (FL) and ranged from 0.013 to 0.668 mg L(-1). Nutrient pretreatment potentiated the toxicity of atrazine as determined by chlorophyll fluorescence activity. Electron transport rates (ETR) were significantly less (48-59%) for plants pretreated with low and ambient nutrient levels in the presence of an average of 107.5-128.1 microg L(-1) atrazine. Significant ETR reductions were also observed for plants exposed to an average of 11.4 microg L(-1) atrazine after exposure to nutrients three times the ambient concentration in the St. Johns River. The results indicate the importance of considering the presence of nutrients in chemical hazard assessments, particularly for phytotoxicants and nontarget vascular plants.

  10. Dynamic speciation analysis of atrazine in aqueous latex nanoparticle dispersions using solid phase microextraction (SPME)

    NARCIS (Netherlands)

    Benhabib, K.; Town, R.M.; Leeuwen, van H.P.

    2009-01-01

    Solid phase microextraction (SPME) is applied in the dynamic speciation analysis of the pesticide atrazine in an aqueous medium containing sorbing latex nanoparticles. It is found that the overall rate of extraction of the analyte is faster than in the absence of nanoparticles and governed by the

  11. Effects of the herbicide atrazine on Ambystoma tigrinum metamorphosis: duration, larval growth, and hormonal response

    Science.gov (United States)

    Larson, Diane L.; McDonald, Susan; Hamilton, Steven J.; Fivizzani, Albert J.; Newton, Wesley E.

    1998-01-01

    We exposed larval tiger salamanders (Ambystoma tigrinum) reared in the laboratory from eggs collected from a prairie wetland in North Dakota to three concentrations of atrazine (0, 75, and 250 i??g/L) in a static renewal test to determine the pesticide's effect on (1) plasma corticosterone and thyroxine concentrations, (2) larval size, and (3) days-to-stage at stages 2 and 4 of metamorphic climax. We found significant effects of atrazine on each of these response variables. Plasma thyroxine was elevated in both atrazine-exposed groups compared to the control group; plasma corticosterone was depressed in the 75 i??g/L treatment compared with both the control and 250 i??g/L treatment. Larvae exposed to 75 i??g/L atrazine reached stage 4 later, but at a size and weight comparable to the control group. By contrast, larvae in the 250 i??g/L treatment progressed to stage 4 at the same time but at a smaller size and lower weight than larvae in the control group. These results indicate that the herbicide has the potential to influence tiger salamander life history. We present a model consistent with our results, whereby corticosterone and thyroxine interact to regulate metamorphosis of tiger salamanders based on nutrient assimilation and adult fitness

  12. Effect of 2,4-D and atrazine when applied with glyphosate ripener

    Science.gov (United States)

    Management of late-season morningglory infestations in sugarcane is accomplished with aerial applications of the postemergence herbicides 2,4-D, dicamba, or atrazine. Likewise, the aerial application of glyphosate prior to harvest to improve stalk sucrose levels is a common practice for many Louisia...

  13. Introduction of biological agents into vegetative buffer to enhance rhizodegradation of atrazine

    Science.gov (United States)

    Introducing atrazine (ATR) degraders into riparian vegetative buffer strips (VBS) can be a promising bioremediation approach to accelerate the degradation of ATR and its degradation products deposited into VBS by surface runoff. A growth chamber study was conducted to investigated the synergistic ef...

  14. Implementation of Contour Vegetative Buffers for Mitigating of Atrazine in Ground Water

    Science.gov (United States)

    The efficacy of vegetative buffer strips (VBS) in intercepting herbicides from surface runoff is well established. However, effect of VBS on fate of the atrazine in ground water has not been widely studied. An established, well calibrated paired watershed consisting of 1) a corn-soybean/tree-grass ...

  15. Fate and risk of atrazine and sulfentrazone to nontarget species at an agriculture site.

    Science.gov (United States)

    Thorngren, Jordan L; Harwood, Amanda D; Murphy, Tracye M; Huff Hartz, Kara E; Fung, Courtney Y; Lydy, Michael J

    2017-05-01

    The present study evaluated the risk associated with the application and co-occurrence of 2 herbicides, atrazine and sulfentrazone, applied to a 32-ha corn and soybean rotational field. Field concentrations of the compounds were measured in soil, runoff water, and groundwater, with peak mean atrazine and sulfentrazone concentrations found in the soil (144 ng/g dry wt, and 318 ng/g dry wt, respectively). Individual and mixture laboratory bioassays were conducted to determine the effects of atrazine and sulfentrazone on the survival of Daphnia magna and Pimephales promelas, the germination of Lactuca sativa, and the growth of Pseudokirchneriella subcapita and Lemna minor. Pseudokirchneriella subcapita and L. minor were the most susceptible species tested, and the effects on growth of the herbicides in mixtures best fit an independent action model. Risk quotients and margin of safety of 10% (MOS10) values were used to estimate risk and were calculated using runoff water concentrations. The MOS10 values were more sensitive than risk quotients in estimating risk. The MOS10 value for sulfentrazone runoff water concentration effects on P. subcapita was 7.8, and for L. minor was 1.1, with MOS10 values < 1 indicating potential risk. Overall, the environmentally relevant concentrations fell below the effect concentrations; therefore, atrazine and sulfentrazone posed little to no risk to the nontarget species tested. Environ Toxicol Chem 2017;36:1301-1310. © 2016 SETAC. © 2016 SETAC.

  16. Immobilization of the white-rot fungus Anthracophyllum discolor to degrade the herbicide atrazine.

    Science.gov (United States)

    Elgueta, S; Santos, C; Lima, N; Diez, M C

    2016-12-01

    Herbicides cause environmental concerns because they are toxic and accumulate in the environment, food products and water supplies. There is a need to develop safe, efficient and economical methods to remove them from the environment, often by biodegradation. Atrazine is such herbicide. White-rot fungi have the ability to degrade herbicides of potential utility. This study formulated a novel pelletized support to immobilize the white-rot fungus Anthracophyllum discolor to improve its capability to degrade the atrazine using a biopurification system (BS). Different proportions of sawdust, starch, corn meal and flaxseed were used to generate three pelletized supports (F1, F2 and F3). In addition, immobilization with coated and uncoated pelletized supports (CPS and UPS, respectively) was assessed. UPS-F1 was determined as the most effective system as it provided high level of manganese peroxidase activity and fungal viability. The half-life (t1/2) of atrazine decreased from 14 to 6 days for the control and inoculated samples respectively. Inoculation with immobilized A. discolor produced an increase in the fungal taxa assessed by DGGE and on phenoloxidase activity determined. The treatment improves atrazine degradation and reduces migration to surface and groundwater.

  17. Evaluation of cytotoxic effects of atrazine and glyphosate herbicides on Biomphalaria glabrata snails

    Directory of Open Access Journals (Sweden)

    Mohamed H. Mona

    2013-03-01

    Full Text Available Biomphalaria glabrata snails were used as bio-indicators for freshwater, atrazine, and glyphosate herbicides. SDS–PAGE protein profiles of B. glabrata snails, isozyme analysis (α- and β-esterase, peroxidase and catalase and RAPD-PCR were used to detect the genotoxicity caused by the two tested herbicides. SDS–PAGE protein profiles showed bands with different molecular weights (53–220 and 1.82–12.5 KDa. The low molecular weight bands appeared in all treated groups except those exposed to 5 ppm glyphosate for 3 weeks. Isozyme analysis revealed three zones of activity (loci, in both α- and β-esterase. On the other hand, peroxidase and catalase showed one locus with different band intensities. Of six arbitrary 10-mer primers, only three primers gave detectable amplifications. A 500 bp band was generated by OPA-10 in all treated groups except in the control and in 5 and 10 ppm atrazine-exposed groups for 2 weeks. A diagnostic band with 400 bp was observed only in 10 ppm atrazine treated group for 3 weeks. Our results indicated that those atrazine and glyphosate herbicides may be considered to be highly genotoxicant agents.

  18. Effect of Biochar on Bioavailability of Atrazine and Metribuzin in Two Soils

    Science.gov (United States)

    Effect of Biochar on Bioavailability of Atrazine and Metribuzin in Two Soils Biochar is a fine-grained, carbon enriched product created when biomass (e.g. wood waste, manures) is burned at relatively low temperatures and under an anoxic atmosphere. Biochar is being added to soil help retain nutri...

  19. Biochar-supported reduced graphene oxide composite for adsorption and coadsorption of atrazine and lead ions

    Science.gov (United States)

    Zhang, Ying; Cao, Bo; Zhao, Lulu; Sun, Lili; Gao, Yan; Li, Jiaojiao; Yang, Fan

    2018-01-01

    To explore potential in application for simultaneous removal of atrazine and lead ions (Pd2+), the adsorption and coadsorption of atrazine and Pd2+ is evaluated onto a novel biochar-supported reduced graphene oxide composite (RGO-BC), which has been successfully developed via slow pyrolysis of graphene oxide (GO) pretreated corn straws. Structure and morphology analysis reveal that GO nanosheets are coated on the surface of biochar (BC) mainly through π-π interactions, notably, GO nanosheets after annealing reduction can basically retain the original morphology, meanwhile, the change of physico-chemical properties on the surface endow excellent adsorption capaities of 26.10 mg g-1 for Pb2+ and 67.55 mg g-1 for atrazine. A significant difference is in sorption of Pb2+ and atrazine on RGO-BC sample in both single- and binary-solute systems. The adsorption capacity of RGO-BC still remained above 54.58 mg g-1 after four times regeneration (81% adsorption capacity remained), demonstrating a promising candidate for the application of removal contaminant in the environment.

  20. Dissipation of atrazine, enrofloxacin, and sulfamethazine in wood chip bioreactors and impact on denitrification

    Science.gov (United States)

    Wood chip bioreactors are receiving increasing attention as a means of reducing nitrate in subsurface tile drainage systems. Agrochemicals in tile drainage water entering wood chip bioreactors can be retained or degraded and may impact denitrification. The degradation of 5 mg L-1 atrazine, enrofloxa...

  1. Evaluation of atrazine plus isoxaflutole (Atoll®) mixture for weed ...

    African Journals Online (AJOL)

    Field experiments were set up in three ecological zones of southwestern Nigeria to evaluate the effectiveness of Atoll® (atrazine + isoxaflutole), a new herbicide mixture, for weed control in maize. Crop i njury rating indicated pronounced phytotoxic effect on crops from 1.34 to 1.61 kg a.i. ha-1 Atoll in all locations. Acceptable ...

  2. Enhanced degradation and soil depth effects on the fate of atrazine and major metabolites in Colorado and Mississippi soils.

    Science.gov (United States)

    Krutz, L Jason; Shaner, Dale L; Zablotowicz, Robert M

    2010-01-01

    The aim of this report is to inform modelers of the differences in atrazine fate between s-triazine-adapted and nonadapted soils as a function of depth in the profile and to recommend atrazine and metabolite input values for pesticide process submodules. The objectives of this study were to estimate the atrazine-mineralizing bacterial population, cumulative atrazine mineralization, atrazine persistence, and metabolite (desethylatrazine [DEA], deisopropylatrazine [DIA], and hydroxyatrazine [HA]) formation and degradation in Colorado and Mississippi s-triazine-adapted and nonadapted soils at three depths (0-5, 5-15, and 15-30 cm). Regardless of depth, the AMBP and cumulative atrazine mineralization was at least 3.8-fold higher in s-triazine-adapted than nonadapted soils. Atrazine half-life (T1/2) values pooled over nonadapted soils and depths approximated historic estimates (T1/2 = 60 d). Atrazine persistence in all depths of s-triazine-adapted soils was at least fourfold lower than that of the nonadapted soil. Atrazine metabolite concentrations were lower in s-triazine-adapted than in nonadapted soil by 35 d after incubation regardless of depth. Results indicate that (i) reasonable fate and transport modeling of atrazine will require identifying if soils are adapted to s-triazine herbicides. For example, our data confirm the 60-d T1/2 for atrazine in nonadapted soils, but a default input value of 6 d for atrazine is required for s-triazine adapted soils. (ii) Literature estimates for DEA, DIA, and HA T1/2 values in nonadapted soils are 52, 36, and 60 d, respectively, whereas our analysis indicates that reasonable T1/2 values for s-triazine-adapted soils are 10 d for DEA, 8 d for DIA, and 6 d for HA. (iii) An estimate for the relative distribution of DIA, DEA, and HA produced in nonadapted soils is 18, 72, and 10% of parent, respectively. In s-triazine-adapted soils, the values were 6, 23, and 71% for DIA, DEA, and HA, respectively. The effects of soil adaptation on

  3. Impact of long-term wastewater irrigation on sorption and transport of atrazine in Mexican agricultural soils

    OpenAIRE

    Muller, K.; Duwig, Céline; Prado, B.; Siebe, C.; Hidalgo, C.; Etchevers, J.

    2012-01-01

    In the Mezquital Valley, Mexico, crops have been irrigated with untreated municipal wastewater for more than a century. Atrazine has been applied to maize and alfalfa grown in the area for weed control for 15 years. Our objectives were to analyse (i) how wastewater irrigation affects the filtering of atrazine, and (ii) if the length of irrigation has a significant impact. We compared atrazine sorption to Phaeozems that have been irrigated with raw wastewater for 35 (P35) and 85 (P85) years wi...

  4. Hypospadias and maternal exposure to atrazine via drinking water in the National Birth Defects Prevention study.

    Science.gov (United States)

    Winston, Jennifer J; Emch, Michael; Meyer, Robert E; Langlois, Peter; Weyer, Peter; Mosley, Bridget; Olshan, Andrew F; Band, Lawrence E; Luben, Thomas J

    2016-07-15

    Hypospadias is a relatively common birth defect affecting the male urinary tract. It has been suggested that exposure to endocrine disrupting chemicals might increase the risk of hypospadias by interrupting normal urethral development. Using data from the National Birth Defects Prevention Study, a population-based case-control study, we considered the role of maternal exposure to atrazine, a widely used herbicide and potential endocrine disruptor, via drinking water in the etiology of 2nd and 3rd degree hypospadias. We used data on 343 hypospadias cases and 1,422 male controls in North Carolina, Arkansas, Iowa, and Texas from 1998-2005. Using catchment level stream and groundwater contaminant models from the US Geological Survey, we estimated atrazine concentrations in public water supplies and in private wells. We assigned case and control mothers to public water supplies based on geocoded maternal address during the critical window of exposure for hypospadias (i.e., gestational weeks 6-16). Using maternal questionnaire data about water consumption and drinking water, we estimated a surrogate for total maternal consumption of atrazine via drinking water. We then included additional maternal covariates, including age, race/ethnicity, parity, and plurality, in logistic regression analyses to consider an association between atrazine and hypospadias. When controlling for maternal characteristics, any association between hypospadias and daily maternal atrazine exposure during the critical window of genitourinary development was found to be weak or null (odds ratio for atrazine in drinking water = 1. 00, 95 % CI = 0.97 to 1.03 per 0.04 μg/day increase; odds ratio for maternal consumption = 1.02, 95 % CI = 0.99 to 1.05; per 0.05 μg/day increase). While the association that we observed was weak, our results suggest that additional research into a possible association between atrazine and hypospadias occurrence, using a more sensitive exposure metric

  5. Removal of atrazine from water by low cost adsorbents derived from agricultural and industrial wastes.

    Science.gov (United States)

    Sharma, Rajendra Kumar; Kumar, Anoop; Joseph, P E

    2008-05-01

    In the present study six adsorbents viz. wood charcoal, fly ash, coconut charcoal, saw dust, coconut fiber and baggasse charcoal were studied for their capacity to remove atrazine from water. The removal efficiency of different adsorbents varied from 76.5% to 97.7% at 0.05 ppm concentration and 78.5% to 95.5% at 0.1 ppm concentration of atrazine solution, which was less than removal efficiency of activated charcoal reported as 98% for atrazine (Adams and Watson, J Environ Eng ASCE 39:327-330, 1996). Wood charcoal was a cheap (Rs 15 kg(-1)) and easily available material in house holds. Since wood charcoal was granular in nature, it could be used for the removal of atrazine from water to the extent of 95.5%-97.7%. Fly ash is a waste product of thermal plant containing 40%-50% silica, 20%-35% alumina, 12%-30% carbon and unburnt minerals having a high pH of 9-10. It is very cheap and abundant material and has comparatively good adsorption capacity. It was found that fly ash effectively removed about 84.1%-88.5% atrazine from water at 0.05 and 0.1 ppm levels. Coconut shell is also waste product. Therefore, both are inexpensive. The removal efficiency of atrazine from water was 92.4%-95.2% by coconut shell charcoal and 85.9%-86.3% by coconut fiber. Sawdust is generally used as domestic fuel and found everywhere. It is also very cheap (Re. 1 kg(-1)). Baggasse charcoal is a waste product of sugar mill and abundant material. Its cost is due to transport expense, which depends upon distance from the sugar mill. The removal efficiency of sawdust and baggasse charcoal was found 78.5-80.5 and 76.5-84.6, respectively. The efficacy of chemically treated adsorbents for the removal of atrazine from water is in the order: wood charcoal > coconut shell charcoal > fly ash > coconut fiber charcoal > baggasse charcoal > sawdust.

  6. Cyclone Codes

    OpenAIRE

    Schindelhauer, Christian; Jakoby, Andreas; Köhler, Sven

    2016-01-01

    We introduce Cyclone codes which are rateless erasure resilient codes. They combine Pair codes with Luby Transform (LT) codes by computing a code symbol from a random set of data symbols using bitwise XOR and cyclic shift operations. The number of data symbols is chosen according to the Robust Soliton distribution. XOR and cyclic shift operations establish a unitary commutative ring if data symbols have a length of $p-1$ bits, for some prime number $p$. We consider the graph given by code sym...

  7. Coding Partitions

    Directory of Open Access Journals (Sweden)

    Fabio Burderi

    2007-05-01

    Full Text Available Motivated by the study of decipherability conditions for codes weaker than Unique Decipherability (UD, we introduce the notion of coding partition. Such a notion generalizes that of UD code and, for codes that are not UD, allows to recover the ``unique decipherability" at the level of the classes of the partition. By tacking into account the natural order between the partitions, we define the characteristic partition of a code X as the finest coding partition of X. This leads to introduce the canonical decomposition of a code in at most one unambiguouscomponent and other (if any totally ambiguouscomponents. In the case the code is finite, we give an algorithm for computing its canonical partition. This, in particular, allows to decide whether a given partition of a finite code X is a coding partition. This last problem is then approached in the case the code is a rational set. We prove its decidability under the hypothesis that the partition contains a finite number of classes and each class is a rational set. Moreover we conjecture that the canonical partition satisfies such a hypothesis. Finally we consider also some relationships between coding partitions and varieties of codes.

  8. A comparative study of the modeled effects of atrazine on aquatic plant communities in midwestern streams.

    Science.gov (United States)

    Nair, Shyam K; Bartell, Steven M; Brain, Richard A

    2015-11-01

    Potential effects of atrazine on the nontarget aquatic plants characteristic of lower-order streams in the Midwestern United States were previously assessed using the Comprehensive Aquatic System Model (CASMATZ ). Another similar bioenergetics-based, mechanistic model, AQUATOX, was examined in the present study, with 3 objectives: 1) to develop an AQUATOX model simulation similar to the CASMATZ model reference simulation in describing temporal patterns of biomass production by modeled plant populations, 2) to examine the implications of the different approaches used by the models in deriving plant community-based levels of concern (LOCs) for atrazine, and 3) to determine the feasibility of implementing alternative ecological models to assess ecological impacts of atrazine on lower-order Midwestern streams. The results of the present comparative modeling study demonstrated that a similar reference simulation to that from the CASMATZ model could be developed using the AQUATOX model. It was also determined that development of LOCs and identification of streams with exposures in excess of the LOCs were feasible with the AQUATOX model. Compared with the CASMATZ model results, however, the AQUATOX model consistently produced higher estimates of LOCs and generated non-monotonic variations of atrazine effects with increasing exposures. The results of the present study suggest an opportunity for harmonizing the treatments of toxicity and toxicity parameter estimation in the CASMATZ and the AQUATOX models. Both models appear useful in characterizing the potential impacts of atrazine on nontarget aquatic plant populations in lower-order Midwestern streams. The present model comparison also suggests that, with appropriate parameterization, these process-based models can be used to assess the potential effects of other xenobiotics on stream ecosystems. © 2015 SETAC.

  9. Fish short-term reproduction assay with atrazine and the Japanese medaka (Oryzias latipes).

    Science.gov (United States)

    Hosmer, Alan J; Schneider, Suzanne Z; Anderson, Julie C; Knopper, Loren D; Brain, Richard A

    2017-09-01

    Breeding groups of Japanese medaka (Oryzias latipes) were exposed to atrazine at measured concentrations of 0.6, 5.5, and 53 μg/L for 35 d. Evaluated endpoints included survival, fecundity, fertility, growth (weight and length), behavior, secondary sex characteristics (anal fin papillae), gonad histopathology, and hepatic vitellogenin. No statistically significant effects of atrazine exposure on survival and growth of medaka were noted during the test, and mean survival was ≥97.5% in all treatment groups on day 35. No significant effects of atrazine exposure on reproduction were observed. The number of mean cumulative eggs produced in the negative control and the 0.6, 5.5, and 53 μg/L treatment groups was 7158, 6691, 6883, and 6856, respectively. The mean number of eggs per female reproductive day was 40.9, 38.2, 40.2, and 39.2, respectively. There were also no dose-dependent effects on mean anal fin papillae counts among male fish or expression of vtg-II in males or females. In addition, atrazine exposure was not related to the developmental stage of test fish, with testes stages ranging from 2 to 3 in all groups and ovaries ranging from stage 2 to 2.5. Overall, exposure to atrazine up to 53 µg/L for 35 d did not result in significant, treatment-related effects on measured endpoints related to survival, growth, or reproduction in Japanese medaka. Environ Toxicol Chem 2017;36:2327-2334. © 2017 SETAC. © 2017 SETAC.

  10. Multiple resistance to atrazine and imazethapyr in hairy beggarticks (Bidens pilosa

    Directory of Open Access Journals (Sweden)

    Hudson Kagueyama Takano

    Full Text Available ABSTRACT Resistance to herbicides is a serious threat to crop production worldwide, especially in agronomic crops and cereals. This research evaluated the possible occurrence of Bidens pilosa resistant to imazethapyr and atrazine in Brazil. The resistant biotype was collected from an area with a history of repeated application of photosystem II (PSII and ALS inhibitor herbicides. The susceptible biotype was collected from an area with no history of herbicide application. Resistance verification experiments were carried out in the greenhouse. The treatments were arranged in a 3 x 8 factorial scheme, where the first factor was populations [susceptible (S, parent resistant (PR, and resistant F1 (RF1]; and the second factor was herbicide dose (0, 375, 750, 1500, 3000, 6000, 12000 and 24000 g ha-1 for atrazine; or 0, 12.5, 25, 50, 100, 200, 400 and 800 g ha-1 for imazethapyr. The resistance factor to atrazine was 2.83 for PR and 5.55 for RF1. This population was more resistant to imazethapyr (>21-fold than it was to atrazine. The recommended maximum dose of the herbicides did not control this B. pilosa population adequately. The data support the claim that B. pilosa population from this field in Quarto Centenário, Parana is resistant to two herbicide modes of action - PSII inhibitor (i.e. atrazine and ALS inhibitor (i.e. imazethapyr. This is the first report of such case for this species, globally. Cross-resistance to other ALS inhibitors and other PS II inhibitors as well as the respective mechanisms of resistance to each herbicide are being investigated.

  11. Atrazine degradation by fungal co-culture enzyme extracts under different soil conditions.

    Science.gov (United States)

    Chan-Cupul, Wilberth; Heredia-Abarca, Gabriela; Rodríguez-Vázquez, Refugio

    2016-01-01

    This investigation was undertaken to determine the atrazine degradation by fungal enzyme extracts (FEEs) in a clay-loam soil microcosm contaminated at field application rate (5 μg g(-1)) and to study the influence of different soil microcosm conditions, including the effect of soil sterilization, water holding capacity, soil pH and type of FEEs used in atrazine degradation through a 2(4) factorial experimental design. The Trametes maxima-Paecilomyces carneus co-culture extract contained more laccase activity and hydrogen peroxide (H2O2) content (laccase = 18956.0 U mg protein(-1), H2O2 = 6.2 mg L(-1)) than the T. maxima monoculture extract (laccase = 12866.7 U mg protein(-1), H2O2 = 4.0 mg L(-1)). Both extracts were able to degrade atrazine at 100%; however, the T. maxima monoculture extract (0.32 h) achieved a lower half-degradation time than its co-culture with P. carneus (1.2 h). The FEE type (p = 0.03) and soil pH (p = 0.01) significantly affected atrazine degradation. The best degradation rate was achieved by the T. maxima monoculture extract in an acid soil (pH = 4.86). This study demonstrated that both the monoculture extracts of the native strain T. maxima and its co-culture with P. carneus can efficiently and quickly degrade atrazine in clay-loam soils.

  12. Study of the Bioremediation of Atrazine under Variable Carbon and Nitrogen Sources by Mixed Bacterial Consortium Isolated from Corn Field Soil in Fars Province of Iran

    Directory of Open Access Journals (Sweden)

    Mansooreh Dehghani

    2013-01-01

    Full Text Available Atrazine herbicide that is widely used in corn production is frequently detected in water resources. The main objectives of this research were focused on assessing the effects of carbon and nitrogen sources on atrazine biodegradation by mixed bacterial consortium and by evaluating the feasibility of using mixed bacterial consortium in soil culture. Shiraz corn field soil with a long history of atrazine application has been explored for their potential of atrazine biodegradation. The influence of different carbon compounds and the effect of nitrogen sources and a different pH (5.5–8.5 on atrazine removal efficiency by mixed bacterial consortium in liquid culture were investigated. Sodium citrate and sucrose had the highest atrazine biodegradation rate (87.22% among different carbon sources. Atrazine biodegradation rate decreased more quickly by the addition of urea (26.76% compared to ammonium nitrate. Based on the data obtained in this study, pH of 7.0 is optimum for atrazine biodegradation. After 30 days of incubation, the percent of atrazine reduction rates were significantly enhanced in the inoculated soils (60.5% as compared to uninoculated control soils (12% at the soil moisture content of 25%. In conclusion, bioaugmentation of soil with mixed bacterial consortium may enhance the rate of atrazine degradation in a highly polluted soil.

  13. Coding Class

    DEFF Research Database (Denmark)

    Ejsing-Duun, Stine; Hansbøl, Mikala

    Sammenfatning af de mest væsentlige pointer fra hovedrapporten: Dokumentation og evaluering af Coding Class......Sammenfatning af de mest væsentlige pointer fra hovedrapporten: Dokumentation og evaluering af Coding Class...

  14. code {poems}

    Directory of Open Access Journals (Sweden)

    Ishac Bertran

    2012-08-01

    Full Text Available "Exploring the potential of code to communicate at the level of poetry," the code­ {poems} project solicited submissions from code­writers in response to the notion of a poem, written in a software language which is semantically valid. These selections reveal the inner workings, constitutive elements, and styles of both a particular software and its authors.

  15. Channel coding techniques for wireless communications

    CERN Document Server

    Deergha Rao, K

    2015-01-01

    The book discusses modern channel coding techniques for wireless communications such as turbo codes, low-density parity check (LDPC) codes, space–time (ST) coding, RS (or Reed–Solomon) codes and convolutional codes. Many illustrative examples are included in each chapter for easy understanding of the coding techniques. The text is integrated with MATLAB-based programs to enhance the understanding of the subject’s underlying theories. It includes current topics of increasing importance such as turbo codes, LDPC codes, Luby transform (LT) codes, Raptor codes, and ST coding in detail, in addition to the traditional codes such as cyclic codes, BCH (or Bose–Chaudhuri–Hocquenghem) and RS codes and convolutional codes. Multiple-input and multiple-output (MIMO) communications is a multiple antenna technology, which is an effective method for high-speed or high-reliability wireless communications. PC-based MATLAB m-files for the illustrative examples are provided on the book page on Springer.com for free dow...

  16. Evaluation of flow injection analysis method with spectrophotometric detection for the determination of atrazine in soil extracts.

    Science.gov (United States)

    Martins, Elisandra C; Melo, Vander De F; Abate, Gilberto

    2016-09-01

    A method for determining atrazine in soil extracts was evaluated by flow injection analysis with spectrophotometric detection. The method is based on the reaction of atrazine with pyridine in an acid medium followed by the reaction with NaOH and sulfanilic acid. Several analytical conditions were previously studied and optimized. Under the best conditions of analysis, the limits of detection and quantification were 0.15 and 0.45 mg L(-1), respectively, for a linear response between 0.50 and 2.50 mg L(-1), and a sampling throughput of 21 determinations per hour. Using the standard addition method, the maximum relative standard deviation of 17% and recovery values between 80 and 100% were observed for three extracts from soil samples with different composition. The proposed method is simple, low-cost and easy to use, and can be employed for studies involving atrazine in soil samples or for screening of atrazine in soils.

  17. Isolation and characterization of a Pseudomonas aeruginosa from a virgin Brazilian Amazon region with potential to degrade atrazine.

    Science.gov (United States)

    Fernandes, Ana Flavia Tonelli; da Silva, Michelle Barbosa Partata; Martins, Vinicius Vicente; Miranda, Carlos Eduardo Saraiva; Stehling, Eliana Guedes

    2014-12-01

    The use of pesticides to increase agricultural production can result in the contamination of the environment, causing changes in the genetic structure of organisms and in the loss of biodiversity. This practice is also inducing changes in the rainforest ecosystem. In this work, a Pseudomonas aeruginosa isolated from a preservation soil area of the Brazilian Amazon Forest, without usage of any pesticide, was evaluated for its potential to degrade atrazine. This isolate presented all responsible genes (atzA, atzB, atzC, atzD, atzE, and atzF) for atrazine mineralization and demonstrated capacity to use atrazine as a nitrogen source, having achieved a reduction of 44 % of the initial concentration of atrazine after 24 h. These results confirm gene dispersion and/or a possible contamination of the area with the herbicide, which reinforces global concern of the increase and intensive use of pesticides worldwide.

  18. Impact of pH buffer capacity of sediment on dechlorination of atrazine using zero valent iron.

    Science.gov (United States)

    Kim, Geonha; Jeong, Woohyeok; Choe, Seunghee

    2007-01-01

    This research investigated the role of the pH buffer capacity of sediment on the dechlorination of atrazine using zero valent iron (ZVI). The buffer capacity of the sediment was quantified by batch experiments and estimated to be 5.0 cmol OH(-) . pH(-1). The sediments were spiked with atrazine at 7.25-36.23 mg kg(-1) (6.21 x 10(-7)-3.09 x 10(-6) mol atrazine . g(-1) sediment) for the batch experiments. The buffer capacity of the sediment maintained the sediment suspension at neutral pH, thereby enabling continuous dechlorination until the buffer capacity of the sediment was depleted. The pseudo-first order dechlorination constants were estimated to be in the range of 1.19 x 10(-2)-7.04 x 10(-2) d(-1) for the atrazine-spiked sediments.

  19. Assessment of selenium and atrazine exposure and effects to wildlife at the North Platte National Wildlife Refuge, Scottsbluff, Nebraska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This study evaluated selenium and atrazine exposure and effects to fish and wildlife at North Platte National Wildlife Refuge (Refuge) in Scotts Bluff County,...

  20. PC-based tele-audiometry.

    Science.gov (United States)

    Choi, Jong Min; Lee, Haet Bit; Park, Cheol Soo; Oh, Seung Ha; Park, Kwang Suk

    2007-10-01

    A personal computer (PC)-based audiometer was developed for interactive remote audiometry. This paper describes a tele-audiometric system and evaluates the performance of the device when compared with conventional face-to-face audiometry. The tele-audiometric system is fully PC-based. A sound card featuring a high-quality digital-to-analog converter is used as a pure-tone generator. The audiometric programs were developed based on Microsoft Windows in order to maximize usability. Audiologists and their subjects can use the tele-audiometry system as one would utilize any PC application. A calibration procedure has been applied for the standardization of sound levels in the remote system. The performance of this system was evaluated by comparing PC-based audiometry with the conventional clinical audiometry system for 37 subjects. Also, performance of the PC-based system was evaluated during use at a remote site. The PC-based audiometry system estimated the audiometric threshold with an error of less than 2.3 dBSPL. Only 10.7% of the results exhibited an error greater than 5 dBSPL during use at a remote site. The PC-based tele-audiomerty showed acceptable results for use at a remote site. This PC-based system can be used effectively and easily in many locations that have Internet access but no local audiologists.

  1. Effectiveness of Integrated Best Management Practices on Mitigation of Atrazine and Metolachlor in an Agricultural Lake Watershed.

    Science.gov (United States)

    Lizotte, Richard; Locke, Martin; Bingner, Ronald; Steinriede, R Wade; Smith, Sammie

    2017-04-01

    The study examined the influence of land-use (cropping patterns) and integrated agricultural best management practices (BMPs) on spring herbicide levels in an agricultural watershed. Atrazine and metolachlor were applied for weed control during spring of 1998-2002, 2005, and 2007-2013. Watershed-wide mass of applied herbicides ranged from 12.7 to 209.2 g atrazine and 10.9-302.2 g metolachlor with greatest application during 1998, 2009-2010 (atrazine) and 2007-2013 (metolachlor). Spring herbicide concentrations in Beasley Lake water ranged from below detection to 3.54 μg atrazine/L and 3.01 μg metolachlor/L. Multiple linear regression analyses with cropping patterns, BMPs, rainfall and time as independent variables, showed atrazine applications were associated with increases in cotton acreage and quail buffer, while metolachlor applications increased over time. Multiple linear regressions showed lake atrazine concentrations were associated with conservation tillage, rainfall, and corn, while lake metolachlor concentrations were associated with the cumulative metolachlor application and sediment retention pond installation.

  2. Atrazine alters expression of reproductive and stress genes in the developing hypothalamus of the snapping turtle, Chelydra serpentina.

    Science.gov (United States)

    Russart, Kathryn L G; Rhen, Turk

    2016-07-29

    Atrazine is an herbicide used to control broadleaf grasses and a suspected endocrine disrupting chemical. Snapping turtles lay eggs between late May and early June, which could lead to atrazine exposure via field runoff. Our goal was to determine whether a single exposure to 2ppb or 40ppb atrazine during embryogenesis could induce short- and long-term changes in gene expression within the hypothalamus of snapping turtles. We treated eggs with atrazine following sex determination and measured gene expression within the hypothalamus. We selected genes a priori for their role in the hypothalamus-pituitary-gonad or the hypothalamus-pituitary-adrenal axes of the endocrine system. We did not identify any changes in gene expression 24-h after treatment. However, at hatching AR, Kiss1R, and POMC expression was upregulated in both sexes, while expression of CYP19A1 and PDYN was increased in females. Six months after hatching, CYP19A1 and PRLH expression was increased in animals treated with 2ppb atrazine. Our study shows persistent changes in hypothalamic gene expression due to low-dose embryonic exposure to the herbicide atrazine with significant effects in both the HPG and HPA axes. Effects reported here appear to be conserved among vertebrates. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Sharing code.

    Science.gov (United States)

    Kubilius, Jonas

    2014-01-01

    Sharing code is becoming increasingly important in the wake of Open Science. In this review I describe and compare two popular code-sharing utilities, GitHub and Open Science Framework (OSF). GitHub is a mature, industry-standard tool but lacks focus towards researchers. In comparison, OSF offers a one-stop solution for researchers but a lot of functionality is still under development. I conclude by listing alternative lesser-known tools for code and materials sharing.

  4. Analog Coding.

    Science.gov (United States)

    CODING, ANALOG SYSTEMS), INFORMATION THEORY, DATA TRANSMISSION SYSTEMS , TRANSMITTER RECEIVERS, WHITE NOISE, PROBABILITY, ERRORS, PROBABILITY DENSITY FUNCTIONS, DIFFERENTIAL EQUATIONS, SET THEORY, COMPUTER PROGRAMS

  5. Involvement of ERK1/2 signaling pathway in atrazine action on FSH-stimulated LHR and CYP19A1 expression in rat granulosa cells

    Energy Technology Data Exchange (ETDEWEB)

    Fa, Svetlana; Pogrmic-Majkic, Kristina; Samardzija, Dragana; Glisic, Branka; Kaisarevic, Sonja; Kovacevic, Radmila; Andric, Nebojsa, E-mail: nebojsa.andric@dbe.uns.ac.rs

    2013-07-01

    Worldwide used herbicide atrazine is linked to reproductive dysfunction in females. In this study, we investigated the effects and the mechanism of atrazine action in the ovary using a primary culture of immature granulosa cells. In granulosa cells, follicle-stimulating hormone (FSH) activates both cyclic adenosine monophosphate (cAMP) and extracellular-regulated kinase 1/2 (ERK1/2) cascades, with cAMP pathway being more important for luteinizing hormone receptor (LHR) and aromatase (CYP19A1) mRNA expression. We report that 48 h after atrazine exposure the FSH-stimulated LHR and CYP19A1 mRNA expression and estradiol synthesis were decreased, with LHR mRNA being more sensitive to atrazine than CYP19A1 mRNA. Inadequate acquisition of LHR in the FSH-stimulated and atrazine-exposed granulosa cells renders human chorionic gonadotropin (hCG) ineffective to stimulate amphiregulin (Areg), epiregulin (Ereg), and progesterone receptor (Pgr) mRNA expression, suggesting anti-ovulatory effect of atrazine. To dissect the signaling cascade involved in atrazine action in granulosa cells, we used U0126, a pharmacological inhibitor of ERK1/2. U0126 prevents atrazine-induced decrease in LHR and CYP19A1 mRNA levels and estradiol production in the FSH-stimulated granulosa cells. ERK1/2 inactivation restores the ability of hCG to induce expression of the ovulatory genes in atrazine-exposed granulosa cells. Cell-based ELISA assay revealed that atrazine does not change the FSH-stimulated ERK1/2 phosphorylation in granulosa cells. The results from this study reveal that atrazine does not affect but requires ERK1/2 phosphorylation to cause decrease in the FSH-induced LHR and CYP19A1 mRNA levels and estradiol production in immature granulosa cells, thus compromising ovulation and female fertility. - Highlights: • Atrazine inhibits estradiol production in FSH-stimulated granulosa cells. • Atrazine inhibits LHR and Cyp19a1 mRNA expression in FSH-stimulated granulosa cells. • Atrazine

  6. BIOREMEDIATION PERSPECTIVES USING AUTOCHTHONOUS SPECIES OF Trichoderma sp. FOR DEGRADATION OF ATRAZINE IN AGRICULTURAL SOIL FROM THE TULANCINGO VALLEY, HIDALGO, MEXICO

    Directory of Open Access Journals (Sweden)

    Margarita Islas Pelcastre

    2013-08-01

    Full Text Available The objective of this study was to show an in vitro bioremediation methodology for atrazine-contaminated soils through the use of local strains of native fungi isolated from the Phaseolus vulgaris L rhizosphere present in cultivable soils as well as to evaluate its resistance and capacity for atrazine degradation. A Trichoderma sp. species was identified in three cultivable soils from the Tulancingo Hidalgo, México region (contaminated with and without atrazine, which resisted atrazine concentrations of 10,000 mg L-1.  Tests showed that the strain grows exponentially in atrazine-contaminated soil over a range of 105-106 CFU g-1 in 15 days using atrazine as the only carbon and nitrogen source, while the control and witress showed a decrease of 100-103 UFC g-1 in the same period of time. For the atrazine degradation experiments, a treatment of the application of Trichoderma (104 - 105 CFU mL-1 was applied to sterilized and non-sterilized soil contaminated with 500 mg Kg-1 of atrazine, evaluated at four time intervals (5, 10, 20 and 40 days. Statistical differences were found (α=0.050, Tukey among treatments with the fungi and the test days. The native Trichoderma strain degraded 89% of the atrazine in 40 days. It showed that it is viable and cultivable in soil bioremediation.

  7. PC floor systems for microelectronics manufacturing buildings

    Science.gov (United States)

    Hong, Kappyo; Lee, Seongsoo; Kwon, Yunhan; Chun, Homin; Cho, Kwangsu; Kim, Sijun

    2010-03-01

    Because a PC(Precast Concrete) system has to follow the transportation rules for transporting PC units and be designed to the specifications of the tools and equipment on site, designing long-span PC systems for microelectronics manufacturing facilities can be troublesome due to complications in transporting, lifting and handling the PC units. To resolve these problems that can occur in long span and heavy weight PC designs, this study proposes two types of long-span PC floor systems that practically use the traditional Gerber beam concept. In the proposed systems, long-span (17.4m) girders or beams are segmented into appropriate lengths using the Gerber system for easy delivery and lifting. Moreover, these systems provide the ability to optimally design massive units by controlling the location of hinge points. On the other hand, because continuous long-span girders or beams are segmented into the Gerber system's hinge points, these systems may generate structural stability problems during construction. Consequently, this study experimentally examines the structural performance of stress transfer mechanism in panel zones and the construction stability of PC units for columns and girders during assembly.

  8. Utilização de acetochlor e atrazine aplicados em mistura de tanque com dessecantes no sistema de plantio direto Reaction of the herbicides acetochlor and atrazine applied in tank mixtures with desiccants in no-till system

    Directory of Open Access Journals (Sweden)

    Benedito N. Rodrigues

    2000-08-01

    Full Text Available A mistura em tanque de herbicidas dessecantes com residuais tem sido utilizada com frequencia pelos agricultores no sistema de plantio direto. Sabe-se, no entanto, que alguns herbicidas residuais têm problemas de retenção na palha quando utilizados isoladamente em préemergência nesse sistema. O objetivo do presente trabalho, foi estudar o comportamento dos herbicidas residuais atrazine e acetochlor em mistura com dessecantes no manejo em plantio direto. Para tal, foi instalado um experimento em blocos ao acaso com parcelas subdivididas e quatro repetições. Os tratamentos, alocados na parcela, em número de nove, foram constituidos pelas seguintes misturas de herbicidas: 1 acetochlor + glyphosate; 2 acetochlor + glyphosate + 2,4D; 3 acetochlor + paraquat; 4 acetochlor + paraquat + 2,4D; 5 atrazine + glyphosate; 6 atrazine + glyphosate + 2,4D; 7 atrazine + paraquat; 8 atrazine + óleo vegetal; 9 testemunha não tratada. Os tratamentos da sub parcela, em número de dois, foram constituidos pelas modalidades de aplicação dos herbicidas na cobertura vegetal: 1 aplicação com a cobertura "em pé"; 2 aplicação com a cobertura "rolada". A cobertura vegetal de inverno era formada pela consorciação de aveia-preta + ervilhaca comum. Os resultados mostraram que o controle de Brachiaria plantaginea, Euphorbia heterophylla e Bidens pilosa foi melhor efetuado com os tratamentos onde entrou o atrazine. De maneira geral, o controle obtido na modalidade "em pé," foi melhor do que na modalidade "rolada," principalmente nos tratamentos com acetochlor. A análise cromatográfica de resíduos feita em amostras de solo retiradas do experimento antes e após uma chuva de 41mm ocorrida 24 horas após a aplicação dos tratamentos, mostrou que menos de 6 % do acetochlor aplicado foi detectado no solo, em ambas as modalidades de aplicação. Quanto ao atrazine, no entanto, mais de 78 % do total aplicado foi detectado no solo após a chuva na modalidade

  9. Potential of macrophytes for removing atrazine from aqueous solution Potencial de macrófitas para remoção de atrazine de solução aquosa

    Directory of Open Access Journals (Sweden)

    F.P Guimarães

    2011-01-01

    Full Text Available The potential of three macrophytes, Azolla caroliniana, Salvinia minima, and Lemna gibba was assessed in this study to select plants for use in environmental remediation contaminated with atrazine. Experiments were carried out in a greenhouse over six days in pots containing Hoagland 0.25 strength nutritive solution at the following atrazine concentrations: 0; 0.01; 0.1; 1.0; 10.0 mg L-1. Decrease in biomass accumulation was observed in the three macrophytes, as well as toxic effects evidenced by the symptomatology developed by the plants which caused their deaths. The chlorosis and necrosis allowed to observe in the plants the high sensitivity of the three species to the herbicide. Plants presented low potential for removal of atrazine in solution when exposed to low concentrations of the herbicide. However, at the 10.0 mg L-1 atrazine concentration, L. gibba and A. caroliniana showed potential to remove the herbicide from the solution (0.016 and 0.018 mg atrazine per fresh mass gram, respectively. This fact likely resulted from the processes of atrazine adsorption by the dead material. The percentage of atrazine removed from the solution by the plants decreased when the plants were exposed to high concentrations of the pollutant. Azolla caroliniana, S. minima, and L. gibba were not effective in removing the herbicide from solution. The use of these species to remedy aquatic environments was shown to be limited.Avaliou-se, neste estudo, o potencial de três macrófitas - Azolla caroliniana, Salvinia minima e Lemna gibba - com vistas à seleção de plantas para remediação de ambientes contaminados por atrazine. Foram realizados experimentos em casa de vegetação durante seis dias, em vasos contendo solução nutritiva Hoagland (0,25 de força iônica, nas seguintes concentrações de atrazine: 0; 0,01; 0,1; 1,0; e 10,0 mg L-1. A redução da biomassa acumulada pelas macrófitas foi observada, bem como os efeitos de toxidez evidenciados pela

  10. Regression models for estimating concentrations of atrazine plus deethylatrazine in shallow groundwater in agricultural areas of the United States.

    Science.gov (United States)

    Stackelberg, Paul E; Barbash, Jack E; Gilliom, Robert J; Stone, Wesley W; Wolock, David M

    2012-01-01

    Tobit regression models were developed to predict the summed concentration of atrazine [6-chloro--ethyl--(1-methylethyl)-1,3,5-triazine-2,4-diamine] and its degradate deethylatrazine [6-chloro--(1-methylethyl)-1,3,5,-triazine-2,4-diamine] (DEA) in shallow groundwater underlying agricultural settings across the conterminous United States. The models were developed from atrazine and DEA concentrations in samples from 1298 wells and explanatory variables that represent the source of atrazine and various aspects of the transport and fate of atrazine and DEA in the subsurface. One advantage of these newly developed models over previous national regression models is that they predict concentrations (rather than detection frequency), which can be compared with water quality benchmarks. Model results indicate that variability in the concentration of atrazine residues (atrazine plus DEA) in groundwater underlying agricultural areas is more strongly controlled by the history of atrazine use in relation to the timing of recharge (groundwater age) than by processes that control the dispersion, adsorption, or degradation of these compounds in the saturated zone. Current (1990s) atrazine use was found to be a weak explanatory variable, perhaps because it does not represent the use of atrazine at the time of recharge of the sampled groundwater and because the likelihood that these compounds will reach the water table is affected by other factors operating within the unsaturated zone, such as soil characteristics, artificial drainage, and water movement. Results show that only about 5% of agricultural areas have greater than a 10% probability of exceeding the USEPA maximum contaminant level of 3.0 μg L. These models are not developed for regulatory purposes but rather can be used to (i) identify areas of potential concern, (ii) provide conservative estimates of the concentrations of atrazine residues in deeper potential drinking water supplies, and (iii) set priorities among

  11. Do the Pc+ pentaquarks have strange siblings?

    Science.gov (United States)

    Lebed, Richard F.

    2015-12-01

    The recent LHCb discovery of states Pc+(4380 ), Pc+(4450 ), believed to be c c ¯u u d pentaquark resonances, begs the question of whether equivalent states with c c ¯→s s ¯ exist, and how they might be produced. The precise analogue to the Pc+ discovery channel Λb→J /ψ K-p , namely, Λc→ϕ π0p , is feasible for this study and indeed is less Cabibbo suppressed, although its limited phase space suggests that evidence of a s s ¯u u d resonance Ps+ would be confined to the kinematic end-point region.

  12. Macromolecular response of individual algal cells to nutrient and atrazine mixtures within biofilms.

    Science.gov (United States)

    Murdock, Justin N; Wetzel, David L

    2012-05-01

    Pollutant effects on biofilm physiology are difficult to assess due to differential susceptibility of species and difficulty separating individual species for analysis. Also, measuring whole assemblage responses such as metabolism can mask species-specific responses, as some species may decrease and others increase metabolic activity. Physiological responses can add information to compositional data, and may be a more sensitive indicator of effect. It is difficult, however, to separate individual species for biochemical analyses. Agricultural runoff often contains multiple pollutants that may alter algal assemblages in receiving waters. It is unclear how mixtures containing potential algal growth stimulators and inhibitors (e.g., nutrients and herbicides) alter algal assemblage structure and function. In research presented here, algal biofilms were exposed to nutrients, atrazine, and their mixtures, and assemblage-level structural and functional changes were measured. Synchrotron infrared microspectroscopy (IMS) was used to isolate the biochemical changes within individual cells from a dominant species of a green alga (Mougeotia sp.), a diatom (Navicula sp.), and a cyanobacterium (Hapalosiphon sp.). At the assemblage level, mixtures generally increased algal biovolume, decreased chlorophyll a, and had no effect on metabolism or ammonium uptake. Navicula had a strong negative response to atrazine initially, but later was more affected by nutrients. Hapalosiphon responded positively to both atrazine and nutrients, and Mougeotia did not exhibit any biochemical trends. Generally, biochemical changes in each species were similar to cells experiencing low stress conditions, with increased relative protein and decreased relative lipid. IMS provided direct evidence that individual species in a natural biofilm can have unique responses to atrazine, nutrients, and mixtures. Results suggest that the initial benthic community composition should have a strong influence on the

  13. Divergence coding for convolutional codes

    Directory of Open Access Journals (Sweden)

    Valery Zolotarev

    2017-01-01

    Full Text Available In the paper we propose a new coding/decoding on the divergence principle. A new divergent multithreshold decoder (MTD for convolutional self-orthogonal codes contains two threshold elements. The second threshold element decodes the code with the code distance one greater than for the first threshold element. Errorcorrecting possibility of the new MTD modification have been higher than traditional MTD. Simulation results show that the performance of the divergent schemes allow to approach area of its effective work to channel capacity approximately on 0,5 dB. Note that we include the enough effective Viterbi decoder instead of the first threshold element, the divergence principle can reach more. Index Terms — error-correcting coding, convolutional code, decoder, multithreshold decoder, Viterbi algorithm.

  14. Small-scale spatial variability of atrazine and dinoseb adsorption parameters in an alluvial soil.

    Science.gov (United States)

    Mermoud, A; Martins, J M F; Zhang, D; Favre, A C

    2008-01-01

    Soil sorption processes largely control the environmental fate of herbicides. Therefore, accuracy of sorption parameters is crucial for accurate prediction of herbicide mobility in agricultural soils. A combined experimental and statistical study was performed to investigate the small-scale spatial variability of sorption parameters for atrazine and dinoseb in soils and to establish the number of samples needed to provide a value of the distribution coefficient (K(d)) next to the mean, with a given precision. The study explored sorption properties of the two herbicides in subsurface samples collected from four pits distributed along a transect of an alluvial soil; two to four samples were taken at about 30 cm apart at each sampling location. When considering all the data, the distribution coefficients were found to be normally and log-normally distributed for atrazine and dinoseb, respectively; the CVs were relatively high (close to 50% for dinoseb and 40% for atrazine). When analyzed horizon by horizon, the data revealed distribution coefficients normally distributed for both herbicides, whatever the soil layer, with lower CVs. The K(d) values were shown to vary considerably between samples collected at very short distance (a few centimeters), suggesting that taking a single soil sample to determine sorption properties through batch experiments can lead to highly unrepresentative results and to poor sorption/mobility predictions.

  15. Reversible electrokinetic adsorption barriers for the removal of atrazine and oxyfluorfen from spiked soils.

    Science.gov (United States)

    Vieira Dos Santos, E; Sáez, C; Cañizares, P; Martínez-Huitle, C A; Rodrigo, M A

    2017-01-15

    This study demonstrates the application of reversible electrokinetic adsorption barrier (REKAB) technology to soils spiked with low-solubility pollutants. A permeable reactive barrier (PRB) of granular activated carbon (GAC) was placed between the anode and cathode of an electrokinetic (EK) soil remediation bench-scale setup with the aim of enhancing the removal of two low-solubility herbicides (atrazine and oxyfluorfen) using a surfactant solution (sodium dodecyl sulfate) as the flushing fluid. This innovative study focused on evaluating the interaction between the EK system and the GAC-PRB, attempting to obtain insights into the primary mechanisms involved. The obtained results highlighted the successful treatment of atrazine and oxyfluorfen in contaminated soils. The results obtained from the tests after 15days of treatment were compared with those obtained using the more conventional electrokinetic soil flushing (EKSF) technology, and very important differences were observed. Although both technologies are efficient for removing the herbicides from soils, REKAB outperforms EKSF. After the 15-day treatment tests, only approximately 10% of atrazine and oxyfluorfen remained in the soil, and adsorption onto the GAC bed was an important removal mechanism (15-17% of herbicide retained). The evaporation loses in REKAB were lower than those obtained in EKSF (45-50% compared to 60-65%). Copyright © 2016 Elsevier B.V. All rights reserved.

  16. The potential applications of using compost chars for removing the hydrophobic herbicide atrazine from solution

    Science.gov (United States)

    Tsui, L.; Roy, W.R.

    2008-01-01

    One commercial compost sample was pyrolyzed to produce chars as a sorbent for removing the herbicide atrazine from solution. The sorption behavior of compost-based char was compared with that of an activated carbon derived from corn stillage. When compost was pyrolyzed, the char yield was greater than 45% when heated under air, and 52% when heated under N2. In contrast, when the corn stillage was pyrolyzed under N2, the yield was only 22%. The N2-BET surface area of corn stillage activated carbon was 439 m2/g, which was much greater than the maximum compost char surface area of 72 m2/g. However, the sorption affinity of the compost char for dissolved atrazine was comparable to that of the corn stillage activated carbon. This similarity could have resulted from the initial organic waste being subjected to a relatively long period of thermal processes during composting, and thus, the compost was more thermally stable when compared with the raw materials. In addition, microorganisms transformed the organic wastes into amorphous humic substances, and thus, it was likely that the microporisity was enhanced. Although this micropore structure could not be detected by the N2-BET method, it was apparent in the atrazine sorption experiment. Overall, the experimental results suggested that the compost sample in current study was a relatively stable material thermally for producing char, and that it has the potential as a feed stock for making high-quality activated carbon. ?? 2007 Elsevier Ltd. All rights reserved.

  17. Development of a bacterial bioassay for atrazine and cyanuric acid detection

    Science.gov (United States)

    Hua, Anna; Gueuné, Hervé; Cregut, Mickaël; Thouand, Gérald; Durand, Marie-José

    2015-01-01

    The s-triazine herbicides are compounds which can disseminate into soils and water. Due to their toxic effects on living organisms, their concentrations in drinking water are legislated by WHO recommendations. Here we have developed for the first time, to the best of our knowledge, an alternative method for physicochemical quantification using two bioluminescent bacterial biosensors: E. coli SM003 for cyanuric acid detection and E. coli SM004 for both atrazine and cyanuric acid detection. The concentration of cyanuric acid detection for E. coli SM003 ranges from 7.83 μM to 2.89 mM, and for E. coli SM004 ranges from 0.22 to 15 μM. Moreover, atrazine detection by E. coli SM004 ranges from 1.08 to 15 μM. According to WHO recommendations, the cyanuric acid detection range is sensitive enough to discriminate between polluted and drinking water. Nevertheless, the detection of atrazine by E. coli SM004 is only applicable for high concentrations of contaminants. PMID:25852669

  18. Development of a bacterial bioassay for atrazine and cyanuric acid detection

    Directory of Open Access Journals (Sweden)

    Anna eHUA

    2015-03-01

    Full Text Available The s-triazine herbicides are compounds which can disseminate into soils and water. Due to their toxic effects on living organisms, their concentrations in drinking water are legislated by WHO recommendations. Here we have developed for the first time, to the best of our knowledge, an alternative method for physicochemical quantification using two bioluminescent bacterial biosensors: E. coli SM003 for cyanuric acid detection and E. coli SM004 for both atrazine and cyanuric acid detection. The concentration of cyanuric acid detection for E. coli SM003 ranges from 7.83 µM to 2.89 mM, and for E. coli SM004 ranges from 0.22 µM to 15 µM. Moreover, atrazine detection by E. coli SM004 ranges from 1.08 µM to 15 µM. According to WHO recommendations, the cyanuric acid detection range is sensitive enough to discriminate between polluted and drinking water. Nevertheless, the detection of atrazine by E. coli SM004 is only applicable for high concentrations of contaminants.

  19. Effect of dispersion on adsorption of atrazine by aqueous suspensions of fullerenes.

    Science.gov (United States)

    Gai, Ke; Shi, Baoyou; Yan, Xiaomin; Wang, Dongsheng

    2011-07-15

    With the widespread application of fullerenes, it is critical to assess their environmental behaviors and their impacts on the transport and bioavailability of organic contaminants. The effects of fullerene particle size, chemistry of the solution, and natural organic matter on the adsorption of atrazine by aqueous dispersions of fullerenes (C(60)) were investigated in this work. The results showed that the Polanyi-Manes model could fit the adsorption isotherms well. Smaller sizes of fullerene particles led to increased available sites and, consequently, enhanced the adsorption of atrazine on C(60). However, intensely dispersed C(60) systems might not possess suitably high adsorptive capacities due to surface chemistry change. Adsorption of atrazine by aqueous dispersions of C(60) increased with a decrease in the pH of the solution. Introduction of humic acid significantly reduced the size of the C(60) particles, and resulted in the increase of the adsorption amount. Fullerene materials, once released into the aquatic environment, are inclined to form aqueous suspensions with different degrees of dispersion, which would greatly affect the transport and fate of organic contaminants.

  20. Bioconcentration of atrazine and chlorophenols into roots and shoots of rice seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Su Yuhong [Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Chemistry Department, Xinjiang University, Urumqi 830046 (China); Zhu Yongguan [Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China)]. E-mail: ygzhu@mail.rcees.ac.cn

    2006-01-15

    Accumulation of o-chlorophenol (CP), 2,4-dichlorophenol (DCP), and atrazine (ATR), as single and mixed contaminants, from hydroponic solutions into roots and shoots of rice seedlings was studied following 48-h exposure of the plant roots. As single contaminants at low levels, the observed bioconcentration factors (BCFs) of CP and DCP with roots approximated the equilibrium values according to the partition-limited model. The BCF of atrazine with roots was about half the partition limit for unknown reasons. The BCFs of CP and ATR with shoots also approximated the partition limits, while the BCF for more lipophilic DCP with shoots was about half the estimated limit, due to insufficient water transport into plants for DCP. As mixed contaminants at low levels, the BCFs with both roots and shoots were comparable with those for the single contaminants; at high levels, the BCFs generally decreased because of the enhanced mixed-contaminant phytotoxicity, as manifested by the greatly reduced plant transpiration rate. - Uptakes of o-chlorophenol, 2,4-dichlorophenol, and atrazine at various levels from nutrient solution by roots and shoots of rice seedlings were investigated using a partition-limited model.

  1. Monitoring of atrazine in milk using a rapid tube-based ELISA and validation with HPLC.

    Science.gov (United States)

    Barchanska, Hanna; Jodo, Elzbieta; Price, Robert Graham; Baranowska, Irena; Abuknesha, Ramadan

    2012-06-01

    Although atrazine has been banned in the European Union since 2007 it still persists in soil from where it can enter the food chain. Milk-producing animals accumulate atrazine from contaminated feed and water and since large quantities of milk and milk products are consumed its quality should be constantly monitored. The objective of this investigation was to develop a simple tube ELISA procedure suitable for use in non-specialised laboratories and in the field. A polyclonal antibody raised in sheep and the hapten-gelatine conjugate was immobilised onto polystyrene tubes. This enables the colour produced to be read on a basic spectrophotometer. Milk samples were collected from three farms in different regions of Poland and diluted before immunoassay was performed. Samples were extracted with hexane-acetone for HPLC analysis. The amount of fat in the milk samples interferes with the dose response so it essential that the standards are prepared in the same samples matrix. A good correlation between 1% and 2% was found between the two methods in the analysis of real samples. However the ELISA procedure was more sensitive that the HPLC method since atrazine was detected in some samples by the ELISA but was not confirmed by the HPLC method. The study demonstrated that the simple antigen-coated tube assay provides a cost effective and valuable screening test that can be easily modified for direct use as a screening tool in the field. Copyright © 2012. Published by Elsevier Ltd.

  2. Mixed-mode sorption of hydroxylated atrazine degradation products to sell: A mechanism for bound residue

    Science.gov (United States)

    Lerch, R.N.; Thurman, E.M.; Kruger, E.L.

    1997-01-01

    This study tested the hypothesis that sorption of hydroxylated atrazine degradation products (HADPs: hydroxyatrazine, HA; deethylhydroxyatrazine, DEHA; and deisopropylhydroxyatrazine, DIHA) to soils occurs by mixed-mode binding resulting from two simultaneous mechanisms: (1) cation exchange and (2) hydrophobic interaction. The objective was to use liquid chromatography and soil extraction experiments to show that mixed-mode binding is the mechanism controlling HADP sorption to soils and is also a mechanism for bound residue. Overall, HADP binding to solid-phase extraction (SPE) sorbents occurred in the order: cation exchange >> octadecyl (C18) >> cyanopropyl. Binding to cation exchange SPE and to a high-performance liquid chromatograph octyl (C8) column showed evidence for mixed-mode binding. Comparison of soil extracted by 0.5 M KH2P04, pH 7.5, or 25% aqueous CH3CN showed that, for HA and DIHA, cation exchange was a more important binding mechanism to soils than hydrophobic interaction. Based on differences between several extractants, the extent of HADP mixed-mode binding to soil occurred in the following order: HA > DIHA > DEHA. Mixed-mode extraction recovered 42.8% of bound atrazine residues from aged soil, and 88% of this fraction was identified as HADPs. Thus, a significant portion of bound atrazine residues in soils is sorbed by the mixed-mode binding mechanisms.

  3. Speaking Code

    DEFF Research Database (Denmark)

    Cox, Geoff

    Speaking Code begins by invoking the “Hello World” convention used by programmers when learning a new language, helping to establish the interplay of text and code that runs through the book. Interweaving the voice of critical writing from the humanities with the tradition of computing and software...... development, Speaking Code unfolds an argument to undermine the distinctions between criticism and practice, and to emphasize the aesthetic and political aspects of software studies. Not reducible to its functional aspects, program code mirrors the instability inherent in the relationship of speech......; alternatives to mainstream development, from performances of the live-coding scene to the organizational forms of commons-based peer production; the democratic promise of social media and their paradoxical role in suppressing political expression; and the market’s emptying out of possibilities for free...

  4. Seasonal synchronicity of algal assemblages in three Midwestern agricultural streams having varying concentrations of atrazine, nutrients, and sediment.

    Science.gov (United States)

    Andrus, J Malia; Winter, Diane; Scanlan, Michael; Sullivan, Sean; Bollman, Wease; Waggoner, J B; Hosmer, Alan J; Brain, Richard A

    2013-08-01

    Numerous studies characterizing the potential effects of atrazine on algal assemblages have been conducted using micro- or mesocosms; however, few evaluations focused on in situ lotic algal communities, potentially confounding risk assessment conclusions. This exploratory study, conducted at several sites in the midwestern United States where atrazine is commonly used, presents in situ observations of native algal communities relative to atrazine exposure and other parameters. Planktonic and periphytic algae from three streams in three Midwestern states, having historically differing atrazine levels, were sampled over a 16-week period in 2011 encompassing atrazine applications and the summer algal growth period at each site. Changes in abundance, diversity, and composition of algal communities were placed in the context of hydrological, climatic, and water quality parameters (including components sometimes present in agricultural runoff) also collected during the study. Diatoms dominated communities at each of the three sites and periphyton was much more abundant than phytoplankton. As expected, significant variations in algal community and environmental parameters were observed between sites. However, correspondence analysis plots revealed that patterns of temporal variation in algal communities at each site and in periphyton or phytoplankton were dominated by seasonal environmental gradients. Significant concordance in these seasonal patterns was detected among sites and between phytoplankton and periphyton communities (via procrustes Protest analysis), suggesting synchronicity of algal communities across a regional scale. While atrazine concentrations generally exhibited seasonal trends at the study watersheds; no effects on algal abundance, diversity or assemblage structure were observed as a result of atrazine pulses. This lack of response may be due to exposure events of insufficient concentration or duration (consistent with previously reported results) or

  5. Fe@Fe2O3 promoted electrochemical mineralization of atrazine via a triazinon ring opening mechanism.

    Science.gov (United States)

    Ding, Xing; Wang, Shengyao; Shen, Wanqiu; Mu, Yi; Wang, Li; Chen, Hao; Zhang, Lizhi

    2017-04-01

    In this study, an electrochemical/electro-Fenton oxidation (EC/EF) system was designed to degrade atrazine, by utilizing boron-doped diamond (BDD) and Fe@Fe2O3 core-shell nanowires loaded active carbon fiber (Fe@Fe2O3/ACF) as the anode and the cathode, respectively. This EC/EF system exhibited much higher degradation rate, decholorination and mineralization efficiency of atrazine than the electrochemical (EC) and electrochemical/traditional electro-Fenton (EC/TEF) oxidation counterpart systems without Fe@Fe2O3 core-shell nanowires. Active species trapping experiment revealed that Fe@Fe2O3 could activate molecular oxygen to produce more OH through Fenton reaction, which favored the atrazine degradation. High performance liquid chromatography, high performance liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry were applied to probe the decomposition and mineralization of atrazine during this novel EC/EF process, which revealed that two intermediates of triazinons (the isomerization of hydroxylated atrazine) were generated during the electrochemical/electro-Fenton oxidation of atrazine in the presence of Fe@Fe2O3 core-shell nanowires. The experimental and theoretical calculation results suggested that atrazine might be degraded via a triazinon ring opening mechanism, while the presence of Fe@Fe2O3 notably accelerated the decholorination process, and produced more hydroxylated products to promote the generation of trazinons and the subsequent ring cleavage as well as the final complete mineralization. This work provides a deep insight into the triazine ring opening mechanism and the design of efficient electrochemical advanced oxidation technologies (EAOTs) for persistent organic pollutant removal. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Management and transmission of DICOM files using PC to PC multicasting methodology.

    Science.gov (United States)

    Kim, I K; Kwon, G B; Choi, W K; Cho, H; Kwak, Y S

    2001-01-01

    The PACS system built and used in hospitals nowadays has quite significant overload on its central server because of both treatment of very large data and full management of medical images. We suggest a distributed communication and management methodology using PC to PC multicasting strategy for efficient management of medical images produced by DICOM modalities. It is absolutely necessary for reducing strict degradation of PACS system due to large size of medical images and its very high transport rates. DICOM PC to PC component is composed a service manager to execute requested queries, a communication manager to take charge of file transmission, and a DICOM manager to manage stored data and system behavior. Each manager itself is a component to search for requested file by interaction or transmit the file to other PCs. Distributed management and transformation of medical information based on PC to PC multicasting methodology will enhance performance of central server and network capacity reducing overload on them.

  7. Effects of in ovo exposure of Imazalil and Atrazine on sexual differentiation in chick gonads

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, J.; Ikeda, M. [Univ. of Shizuoka, Shizuoka (Japan); Matsushita, S.; Iwasawa, T.; Ikeya, M. [Shizuoka Swine and Poultry Experiment Station, Kikugawa (Japan)

    2004-09-15

    numerous anti-fungal chemicals. These chemicals have shown to reversibly (although not necessarily competitively) inhibit aromatase activity in human placental microsomes. It is reported that imazalil and difenoconazole inhibit aromatase activity in human adrenocortical carcinoma cell line H295R. Atrazine is the most commonly used herbicide in the word. There are several reports about the adverse effects of atrazine exposure. Atrazine induced hermaphroditism in African clawed frogs and demasculinized the larynx in male frogs. Plasma testosterone concentration in male frogs was decreased by atrazine exposure, and plasma estradiol concentration in rats was increased by atrazine exposure. Atrazine also increased aromatase activity in human adrenocortical carcinoma cell line H295R by inducing aromatase mRNA. In this study, the effects of in ovo exposure to an aromatase-inhibiting chemical (imazalil) and an aromatase-activating chemical (atrazine) on the sexual differentiation of chick gonad were investigated.

  8. Coding Labour

    Directory of Open Access Journals (Sweden)

    Anthony McCosker

    2014-03-01

    Full Text Available As well as introducing the Coding Labour section, the authors explore the diffusion of code across the material contexts of everyday life, through the objects and tools of mediation, the systems and practices of cultural production and organisational management, and in the material conditions of labour. Taking code beyond computation and software, their specific focus is on the increasingly familiar connections between code and labour with a focus on the codification and modulation of affect through technologies and practices of management within the contemporary work organisation. In the grey literature of spreadsheets, minutes, workload models, email and the like they identify a violence of forms through which workplace affect, in its constant flux of crisis and ‘prodromal’ modes, is regulated and governed.

  9. Coding labour

    National Research Council Canada - National Science Library

    McCosker, Anthony; Milne, Esther

    2014-01-01

    ... software. Code encompasses the laws that regulate human affairs and the operation of capital, behavioural mores and accepted ways of acting, but it also defines the building blocks of life as DNA...

  10. Growth and protein metabolism in red drum (Sciaenops ocellatus) larvae exposed to environmental levels of atrazine and malathion.

    Science.gov (United States)

    McCarthy, Ian D; Fuiman, Lee A

    2008-07-30

    Contaminant exposure can affect development, growth, and behaviour of fish larvae, but its effect on rates of protein synthesis and protein degradation are not known. The aim of the present study was to examine the effects of a single pulsed dose aqueous exposure to environmentally realistic levels of two contaminants, atrazine (0, 40 and 80 microgl(-1)) and malathion (0, 1 and 10 microgl(-1)), on growth and protein synthesis in red drum (Sciaenops ocellatus) larvae. Growth was assessed in terms of increase in length, weight, and protein content over an 8-day period following exposure. Rates of protein synthesis were measured by the flooding dose technique 2, 4, and 8 days after initial exposure to each contaminant by bathing larvae in seawater containing L-[2,6-(3)H] phenylalanine. Exposure to atrazine had no effect on larval growth in length, but caused marginally significant declines in growth in weight (P=0.05) and protein content (P=0.06). However, protein synthesis rates were significantly higher for atrazine-exposed larvae on days 4 (P=0.04) and 8 (P=0.01), suggesting an increase in rates of protein degradation. On day 8, the efficiency with which synthesised proteins contributed to growth was significantly lower (P=0.04) in atrazine-exposed larvae. In contrast, malathion had no significant effects on growth in length or protein content, but there were significant decreases in growth in weight over 8 days. The only other significant effect of malathion was an increase in protein synthesis on day 2 for treated larvae relative to controls. Previous work [Alvarez, M.C., Fuiman, L.A., 2005. Environmental levels of atrazine and its degradation products impair survival skills and growth of red drum larvae. Aquat. Toxicol. 74, 229-241] reported hyperactivity and increased metabolic rate in larval red drum exposed to atrazine, indicating a clear energetic cost. Our results further emphasise the energetic cost of atrazine exposure through elevated rates of protein

  11. Simulation of branched serial first-order decay of atrazine and metabolites in adapted and nonadapted soils

    Science.gov (United States)

    Webb, Richard M.; Sandstrom, Mark W.; Jason L. Krutz,; Dale L. Shaner,

    2011-01-01

    In the present study a branched serial first-order decay (BSFOD) model is presented and used to derive transformation rates describing the decay of a common herbicide, atrazine, and its metabolites observed in unsaturated soils adapted to previous atrazine applications and in soils with no history of atrazine applications. Calibration of BSFOD models for soils throughout the country can reduce the uncertainty, relative to that of traditional models, in predicting the fate and transport of pesticides and their metabolites and thus support improved agricultural management schemes for reducing threats to the environment. Results from application of the BSFOD model to better understand the degradation of atrazine supports two previously reported conclusions: atrazine (6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine) and its primary metabolites are less persistent in adapted soils than in nonadapted soils; and hydroxyatrazine was the dominant primary metabolite in most of the soils tested. In addition, a method to simulate BSFOD in a one-dimensional solute-transport unsaturated zone model is also presented.

  12. Similarities and differences in occurrence and temporal fluctuations in glyphosate and atrazine in small Midwestern streams (USA) during the 2013 growing season

    Science.gov (United States)

    Mahler, Barbara J.; Van Metre, Peter C.; Burley, Thomas E.; Loftin, Keith A.; Meyer, Michael T.; Nowell, Lisa H.

    2017-01-01

    Glyphosate and atrazine are the most intensively used herbicides in the United States. Although there is abundant spatial and temporal information on atrazine occurrence at regional scales, there are far fewer data for glyphosate, and studies that compare the two herbicides are rare. We investigated temporal patterns in glyphosate and atrazine concentrations measured weekly during the 2013 growing season in 100 small streams in the Midwestern United States. Glyphosate was detected in 44% of samples (method reporting level 0.2 μg/L); atrazine was detected above a threshold of 0.2 μg/L in 54% of samples. Glyphosate was detected more frequently in 12 urban streams than in 88 agricultural streams, and at concentrations similar to those in streams with high agricultural land use (> 40% row crop) in the watershed. In contrast, atrazine was detected more frequently and at higher concentrations in agricultural streams than in urban streams. The maximum concentration of glyphosate measured at most urban sites exceeded the maximum atrazine concentration, whereas at agricultural sites the reverse was true. Measurement at a 2-day interval at 8 sites in northern Missouri revealed that transport of both herbicide compounds appeared to be controlled by spring flush, that peak concentration duration was brief, but that peaks in atrazine concentrations were of longer duration than those of glyphosate. The 2-day sampling also indicated that weekly sampling is unlikely to capture peak concentrations of glyphosate and atrazine.

  13. Molecularly imprinted polymer applied to the determination of the residual mass of atrazine and metabolites within an agricultural catchment (Brévilles, France).

    Science.gov (United States)

    Amalric, L; Mouvet, C; Pichon, V; Bristeau, S

    2008-10-10

    Atrazine, desethyl-atrazine and desisopropyl-atrazine have been measured in the soils of Brévilles watershed. Pressurised liquid extraction (PLE) technique was used for extraction followed by purification with terbutylazine molecularly imprinted polymers. This clean-up procedure allowed to remove interfering compounds from the sample extracts. Thus making easier the analyses by reversed phase liquid chromatography coupled with ion trap tandem mass spectrometry. This selective sample treatment for soil extracts allowed limit of quantification (LOQ) of 0.03 ng/g for atrazine and 0.05 ng/g for metabolites. The concentrations in soil samples ranged from 7.1 ng/g to water infiltrating with concentrations higher than the drinking water limit, 7 years after the last application of atrazine.

  14. Microbial adaption to a pesticide in agricultural soils: Accelerated degradation of 14C-atrazine in field soils from Brazil and Belgium

    Science.gov (United States)

    Jablonowski, Nicolai David; Martinazzo, Rosane; Hamacher, Georg; Accinelli, Cesare; Köppchen, Stephan; Langen, Ulrike; Linden, Andreas; Krause, Martina; Burauel, Peter

    2010-05-01

    An increasing demand for food, feed and bioenergy, and simultaneously a decline of arable land will require an intensive agricultural production including the use of pesticides. With an increasing use of pesticides the occurrence of an accelerated degradation potential has to be assessed. Atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] is one of the most widely used herbicides in the world. Even though its use was banned in several countries it is still widely used throughout America and the Asia-Pacific region. Atrazine is the most widely used herbicide in maize plantations in Brazil and the US. The use of atrazine in Belgium and all EU member states was banned in September 2004, with the permission to consume existing stocks until October 2005. Atrazine and its residues are still regularly detected in soil, ground and surface waters even years after its prohibition. Its persistence in soil and in association with organic particles might become crucial in terms of erosion due to climate and environmental changes. Due to its potential microbiological accessibility, the microbial mineralization of atrazine competes with chemical/physical interaction such as sorption and binding processes of the chemical molecule in the soil matrix. Binding or intrusion of the chemical on soil components results in a decrease of its accessibility for soil microbes, which does not necessarily exclude the molecule from environmental interactions. In the present study the accelerated atrazine degradation in agriculturally used soils was examined. Soil samples were collected from a Rhodic Ferralsol, Campinas do Sul, South Brazil, and Geric Ferralsol, Correntina, Northeastern Brazil. The sampling site of the Rhodic Ferralsol soil has been under crop rotation (soybean/wheat/maize/oat) since 1990. The Geric Ferralsol site has alternately been cultivated with maize and soybean since 2000. Both areas have been treated biennially with atrazine at recommended doses of 1.5 - 3

  15. Desain dan Implementasi Sistem Kendali CNC Router Menggunakan PC untuk Flame Cutting Machine

    Directory of Open Access Journals (Sweden)

    Roni Permana Saputra

    2012-03-01

    Full Text Available This paper focuses on design of router control systems based on computer numerical control (CNC using personal computer (PC implemented in flame cutting machine (FCM. NC-Code entered into the computer translated to be a command signal sent by the PC to a microcontroller to control the end effector’s movement alongthe X and Y axis simultaneously based on linear and circular interpolations calculation on the PC. This control system is implemented on FCM by connecting the output control of the microcontroller with the driver actuator of the FCM in the form of a DC motor. The obtained result is in the form of a CNC router control system prototype to be implemented in the FCM which is capable to perform linear interpolation and circular interpolation. 

  16. Speech coding

    Energy Technology Data Exchange (ETDEWEB)

    Ravishankar, C., Hughes Network Systems, Germantown, MD

    1998-05-08

    Speech is the predominant means of communication between human beings and since the invention of the telephone by Alexander Graham Bell in 1876, speech services have remained to be the core service in almost all telecommunication systems. Original analog methods of telephony had the disadvantage of speech signal getting corrupted by noise, cross-talk and distortion Long haul transmissions which use repeaters to compensate for the loss in signal strength on transmission links also increase the associated noise and distortion. On the other hand digital transmission is relatively immune to noise, cross-talk and distortion primarily because of the capability to faithfully regenerate digital signal at each repeater purely based on a binary decision. Hence end-to-end performance of the digital link essentially becomes independent of the length and operating frequency bands of the link Hence from a transmission point of view digital transmission has been the preferred approach due to its higher immunity to noise. The need to carry digital speech became extremely important from a service provision point of view as well. Modem requirements have introduced the need for robust, flexible and secure services that can carry a multitude of signal types (such as voice, data and video) without a fundamental change in infrastructure. Such a requirement could not have been easily met without the advent of digital transmission systems, thereby requiring speech to be coded digitally. The term Speech Coding is often referred to techniques that represent or code speech signals either directly as a waveform or as a set of parameters by analyzing the speech signal. In either case, the codes are transmitted to the distant end where speech is reconstructed or synthesized using the received set of codes. A more generic term that is applicable to these techniques that is often interchangeably used with speech coding is the term voice coding. This term is more generic in the sense that the

  17. Found a USB stick? Go and infect your PC!

    CERN Multimedia

    Computer Security Team

    2012-01-01

    Err. Wait. Please no! USB sticks are not innocent little things. They can quickly mutate into malicious nasty beasts! Just in the recent past, at least two physics experiments were suffering as their control and data acquisition PCs, respectively, were infected by USB sticks holding malicious code. A bit longer ago, a series of laptops were infected at a 2008 computing conference as an infected USB stick made its tour around. Bad luck for those who ran a Windows operating system and inserted that stick…   So, you found a USB stick in the cafeteria? Take care. If this were a lollipop, you wouldn’t just pick it up and lick it, would you? So beware of USB sticks whose origin or previous usage you don’t know. They might infect your PC once plugged in. In order to be on the safe side, accept and share only USB sticks whose owner you trust. Run up-to-date anti-virus software on your PC, make sure that its operating system is patched...

  18. Sorption of acetochlor, atrazine, 2,4-D, chlorotoluron, MCPA, and trifluralin in six soils from Slovakia.

    Science.gov (United States)

    Hiller, Edgar; Krascsenits, Zoltán; Cernanský, Slavomír

    2008-05-01

    Sorption of the herbicides (acetochlor, atrazine, 2,4-D: , chlorotoluron, MCPA and trifluralin) in their commercially available formulations was characterized on six agricultural soils from Slovakia. Weak acid herbicides (2,4-D: and MCPA) were the least sorbed, whereas weak base such as atrazine and nonionic herbicides were the most sorbed in the order: atrazine herbicides expressed as logKOW. The KF values positively correlated with soil organic carbon content for all herbicides. Moreover, all herbicides were the most sorbed by Vertisol with relatively high smectite clay content in proportion to organic carbon content. The KOC values for each herbicide showed a smaller variation among soils (excluding Vertisol) than the KF and were used to compare soil mobility potential of herbicides.

  19. Peak Pc Prediction in Conjunction Analysis: Conjunction Assessment Risk Analysis. Pc Behavior Prediction Models

    Science.gov (United States)

    Vallejo, J.J.; Hejduk, M.D.; Stamey, J. D.

    2015-01-01

    Satellite conjunction risk typically evaluated through the probability of collision (Pc). Considers both conjunction geometry and uncertainties in both state estimates. Conjunction events initially discovered through Joint Space Operations Center (JSpOC) screenings, usually seven days before Time of Closest Approach (TCA). However, JSpOC continues to track objects and issue conjunction updates. Changes in state estimate and reduced propagation time cause Pc to change as event develops. These changes a combination of potentially predictable development and unpredictable changes in state estimate covariance. Operationally useful datum: the peak Pc. If it can reasonably be inferred that the peak Pc value has passed, then risk assessment can be conducted against this peak value. If this value is below remediation level, then event intensity can be relaxed. Can the peak Pc location be reasonably predicted?

  20. DVD player for the PC environment

    Science.gov (United States)

    Horne, Caspar; Bheda, Hemant; Srivinasan, Partha

    1998-10-01

    The DVD read-only disk provides high quality storage of audio visual contents, and is especially suitable for the storage of movie contents. Stand-alone consumer playback devices are already available on the market, and wide-spread use of DVD ROM is expected for the PC market, as PC peripheral. In the PC environment, the majority of MPEG1 based layers, such as Video CD players, are software players. Performance of such players is indistinguishable from hardware-based players. However, DVD player that using software only remains a challenging task. To tackle this problem we will describe a DVD player that is based on a new architecture, that allows high quality playback of DVD material. The architecture allows software only playback, as well as hardware assisted DVD playback, while adding little to the total system cost.

  1. Effect of Cell-to-matrix Ratio in Polyvinyl Alcohol Immobilized Pure and Mixed Cultures on Atrazine Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Siripattanakul, Sumana [Chulalongkorn University, National Research Center for Environmental and Hazardous Waste Management (Thailand); Wirojanagud, Wanpen [Khon Kaen University, Department of Environmental Engineering and Research Center for Environmental and Hazardous Substance Management (Thailand); McEvoy, John [North Dakota State University, Department of Veterinary and Microbiological Sciences (United States); Khan, Eakalak [North Dakota State University, Department of Civil Engineering (United States)], E-mail: eakalak.khan@ndsu.edu

    2008-08-15

    Atrazine biodegradation by immobilized pure and mixed cultures was examined. A pure atrazine-degrading culture, Agrobacterium radiobacter J14a (J14a), and a mixed culture (MC), isolated from an atrazine-contaminated crop field, were immobilized using phosphorylated-polyvinyl alcohol (PPVA). An existing cell immobilization procedure was modified to enhance PPVA matrix stability. The results showed that the matrices remained mechanically and chemically stable after shaking with glass beads over 15 days under various salt solutions and pH values. The immobilization process had a slight effect on cell viability. With the aid of scanning electron microscopy, a suitable microstructure of PPVA matrices for cell entrapment was observed. There were two porous layers of spherical gel matrices, the outside having an encapsulation property and the inside containing numerous pores for bacteria to occupy. J14a and MC were immobilized at three cell-to-matrix ratios of 3.5, 6.7, and 20 mg dry cells/mL matrix. The atrazine biodegradation tests were conducted in an aerobic batch system, which was inoculated with cells at 2,000 mg/L. The tests were also conducted using free (non-immobilized) J14a and MC for comparative purpose. The cell-to-matrix ratio of 3.5 mg/mL provided the highest atrazine removal efficiency of 40-50% in 120 h for both J14a and MC. The free cell systems, for both cultures, presented much lower atrazine removal efficiencies compared to the immobilized cell systems at the same level of inoculation.

  2. Impact of long-term wastewater irrigation on sorption and transport of atrazine in Mexican agricultural soils.

    Science.gov (United States)

    Müller, K; Duwig, C; Prado, B; Siebe, C; Hidalgo, C; Etchevers, J

    2012-01-01

    In the Mezquital Valley, Mexico, crops have been irrigated with untreated municipal wastewater for more than a century. Atrazine has been applied to maize and alfalfa grown in the area for weed control for 15 years. Our objectives were to analyse (i) how wastewater irrigation affects the filtering of atrazine, and (ii) if the length of irrigation has a significant impact. We compared atrazine sorption to Phaeozems that have been irrigated with raw wastewater for 35 (P35) and 85 (P85) years with sorption to a non-irrigated (P0) Phaeozem soil under rainfed agriculture. The use of bromide as an inert water tracer in column experiments and the subsequent analysis of the tracers' breakthrough curves allowed the calibration of the hydrodynamic parameters of a two-site non equilibrium convection-dispersion model. The quality of the irrigation water significantly altered the soils' hydrodynamic properties (hydraulic conductivity, dispersivity and the size of pores that are hydraulically active). The impacts on soil chemical properties (total organic carbon content and pH) were not significant, while the sodium adsorption ratio was significantly increased. Sorption and desorption isotherms, determined in batch and column experiments, showed enhanced atrazine sorption and reduced and slower desorption in wastewater-irrigated soils. These effects increased with the length of irrigation. The intensified sorption-desorption hysteresis in wastewater-irrigated soils indicated that the soil organic matter developed in these soils had fewer high-energy, easily accessible sorption sites available, leading to lower and slower atrazine desorption rates. This study leads to the conclusion that wastewater irrigation decreases atrazine mobility in the Mezquital valley Phaeozems by decreasing the hydraulic conductivity and increasing the soil's sorption capacity.

  3. Photocatalytic oxidation of VOC, nitrogen oxide and atrazine using titanium dioxide modified with perovskite materials

    Science.gov (United States)

    Vajifdar, Kayzad Jimmy

    to meet the EPA's ever tightening emission standards and will give architects and town planners a new weapon in the fight against pollution in the foreseeable future. This chapter also shows the visible-light excited photocatalytic oxidation of NOx at different inlet NO concentration, space time, and relative humidity. The reaction products are studied with a NOx analyzer and ion chromatography from gas phase, catalyst and scrubber liquor. A possible mechanism is proposed. The oxidation products are NO 2, HNO2, and HNO3. The former can be captured in an adsorbent bed and recovered as nitric acid. Chapter 3 investigates the photocatalytic oxidation (PCO) of atrazine in aqueous solution under 9 W fluorescent light irradiation using four different types of photocatalysts: Degussa P-25 standard TiO2, Ecodevice BA-PW25, Nd-doped TiO2 prepared by sol-gel technique and TiO 2 modified with BaTiO3. With an initial atrazine concentration of 60 ppb, after PCO only two products remain in detectable levels. Up to 77% of decomposed atrazine becomes hydroxyatrazine, the major byproduct; the second product peak remains undefined. Both atrazine and hydroxyatrazine photodecompose following the first order rate equation, but the hydroxyatrazine photodecomposition rate is significantly slower than that of atrazine. Doping TiO2 with Nd+3/Ba+2 reduces the photodegradation time. The difference in the ionic radii of Ba+2 and Nd +3 as compared to Ti+4, and the oxygen affinities of Ba and Nd as compared to Ti are responsible for this effect. These differences help to promote electron trapping, thereby increasing the lifetime of the holes that are responsible for the oxidation of atrazine.

  4. Tablet PC Support of Students' Learning Styles

    Directory of Open Access Journals (Sweden)

    Shreya Kothaneth

    2012-12-01

    Full Text Available In the context of rapid technology development, it comes as no surprise that technology continues to impact the educational domain, challenging traditional teaching and learning styles. This study focuses on how students with different learning styles use instructional technology, and in particular, the tablet PC, to enhance their learning experience. The VARK model was chosen as our theoretical framework as we analyzed responses of an online survey, both from a quantitative and qualitative standpoint. Results indicate that if used correctly, the tablet PC can be used across different learning styles to enrich the educational experience.

  5. Effects of atrazine in fish, amphibians, and reptiles: an analysis based on quantitative weight of evidence.

    Science.gov (United States)

    Van Der Kraak, Glen J; Hosmer, Alan J; Hanson, Mark L; Kloas, Werner; Solomon, Keith R

    2014-12-01

    A quantitative weight of evidence (WoE) approach was developed to evaluate studies used for regulatory purposes, as well as those in the open literature, that report the effects of the herbicide atrazine on fish, amphibians, and reptiles. The methodology for WoE analysis incorporated a detailed assessment of the relevance of the responses observed to apical endpoints directly related to survival, growth, development, and reproduction, as well as the strength and appropriateness of the experimental methods employed. Numerical scores were assigned for strength and relevance. The means of the scores for relevance and strength were then used to summarize and weigh the evidence for atrazine contributing to ecologically significant responses in the organisms of interest. The summary was presented graphically in a two-dimensional graph which showed the distributions of all the reports for a response. Over 1290 individual responses from studies in 31 species of fish, 32 amphibians, and 8 reptiles were evaluated. Overall, the WoE showed that atrazine might affect biomarker-type responses, such as expression of genes and/or associated proteins, concentrations of hormones, and biochemical processes (e.g. induction of detoxification responses), at concentrations sometimes found in the environment. However, these effects were not translated to adverse outcomes in terms of apical endpoints. The WoE approach provided a quantitative, transparent, reproducible, and robust framework that can be used to assist the decision-making process when assessing environmental chemicals. In addition, the process allowed easy identification of uncertainty and inconsistency in observations, and thus clearly identified areas where future investigations can be best directed.

  6. Dissipation of atrazine, enrofloxacin, and sulfamethazine in wood chip bioreactors and impact on denitrification.

    Science.gov (United States)

    Ilhan, Z E; Ong, S K; Moorman, T B

    2011-01-01

    Wood chip bioreactors are receiving increasing attention as a means of reducing nitrate in subsurface tile drainage systems. Agrochemicals in tile drainage water entering wood chip bioreactors can be retained or degraded and may affect denitrification. The degradation of 5 mg L atrazine, enrofloxacin, and sulfamethazine under denitrifying conditions in wood chips from an in situ reactor was determined. The impact of these chemicals on denitrifying microorganisms was assessed using the denitrification potential assay, most probable number (MPN), and quantitative polymerase chain reaction targeting the gene of the denitrifiers. Initial half-lives for these chemicals in the aqueous phase were 0.98 d for atrazine, 0.17 d for enrofloxacin, and 6.2 d for sulfamethazine. Similar rates of disappearance in autoclaved and nonautoclaved wood chip solutions during the first 48 h suggested sorption was the dominant mechanism. The presence of atrazine did not impair denitrification potential, the MPN, or the copy number. The denitrifier MPN and copy number in sulfamethazine- and enrofloxacin-treated microcosms were less than the control within the first 5 d after chemical addition, whereas the denitrification potentials were not affected. However, after 45 d the denitrification rate, MPN and gene copy numbers for sulfamethazine and enrofloxacin were similar to that of the no-chemical control, indicating that acclimation of the denitrifier population to the antibiotic or reduced bioavailability over time allowed recovery of the denitrifier population. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  7. Tillage, intercrop, and controlled drainage-subirrigation influence atrazine, metribuzin, and metolachlor loss.

    Science.gov (United States)

    Gaynor, J D; Tan, C S; Drury, C F; Ng, H Y; Welacky, T W; van Wesenbeeck, I J

    2001-01-01

    Atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) and metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] have been found with increasing occurrence in rivers and streams. Their continued use will require changes in agricultural practices. We compared water quality from four crop-tillage treatments: (i) conventional moldboard plow (MB), (ii) MB with ryegrass (Lolium multiflorum Lam.) intercrop (IC), (iii) soil saver (SS), and (iv) SS + IC; and two drainage control treatments, drained (D) and controlled drainage-subirrigation (CDS). Atrazine (1.1 kg a.i. ha-1), metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazine-5(4H)-one] (0.5 kg a.i. ha-1), and metolachlor (1.68 kg a.i. ha-1) were applied preemergence in a band over seeded corn (Zea mays L.) rows. Herbicide concentration and losses were monitored from 1992 to spring 1995. Annual herbicide losses ranged from < 0.3 to 2.7% of application. Crop-tillage treatment influenced herbicide loss in 1992 but not in 1993 or 1994, whereas CDS affected partitioning of losses in most years. In 1992, SS + IC reduced herbicide loss in tile drains and surface runoff by 46 to 49% compared with MB. The intercrop reduced surface runoff, which reduced herbicide transport. Controlled drainage-subirrigation increased herbicide loss in surface runoff but decreased loss through tile drainage so that total herbicide loss did not differ between drainage treatments. Desethyl atrazine [6-chloro-N-(1-methylethyl)-1,3,5-triazine-2,4-diamine] comprised 7 to 39% of the total triazine loss.

  8. Mitigation of atrazine, S-metolachlor, and diazinon using common emergent aquatic vegetation.

    Science.gov (United States)

    Moore, Matthew T; Locke, Martin A; Kröger, Robert

    2017-06-01

    By the year 2050, the population of the United States is expected to reach over 418 million, while the global population will reach 9.6 billion. To provide safe food and fiber, agriculture must balance pesticide usage against impacts on natural resources. Challenges arise when storms cause runoff to be transported to aquatic receiving systems. Vegetated systems such as drainage ditches and constructed wetlands have been proposed as management practices to alleviate pesticide runoff. Twelve experimental mesocosms (1.3×0.71×0.61m) were filled with sediment and planted with a monoculture of one of three wetland plant species (Typha latifolia, Leersia oryzoides, and Sparganium americanum). Three mesocosms remained unvegetated to serve as controls. All mesocosms were amended with 9.2±0.8μg/L, 12±0.4μg/L, and 3.1±0.2μg/L of atrazine, metolachlor, and diazinon, respectively, over a 4hr hydraulic retention time to simulate storm runoff. Following the 4hr amendment, non-amended water was flushed through mesocosms for an additional 4hr. Outflow water samples were taken hourly from pre-amendment through 8hr, and again at 12, 24, 48, 72, and 168hr post-amendment. L. oryzoides and T. latifolia had mean atrazine, metolachlor, and diazinon retentions from 51%-55% for the first 4hr of the experiment. Aside from S. americanum and atrazine (25% retention), unvegetated controls had the lowest pesticide retention (17%-28%) of all compared mesocosms. While native aquatic vegetation shows promise for mitigation of pesticide runoff, further studies increasing the hydraulic retention time for improved efficiency should be examined. Copyright © 2016. Published by Elsevier B.V.

  9. The Aster code; Code Aster

    Energy Technology Data Exchange (ETDEWEB)

    Delbecq, J.M

    1999-07-01

    The Aster code is a 2D or 3D finite-element calculation code for structures developed by the R and D direction of Electricite de France (EdF). This dossier presents a complete overview of the characteristics and uses of the Aster code: introduction of version 4; the context of Aster (organisation of the code development, versions, systems and interfaces, development tools, quality assurance, independent validation); static mechanics (linear thermo-elasticity, Euler buckling, cables, Zarka-Casier method); non-linear mechanics (materials behaviour, big deformations, specific loads, unloading and loss of load proportionality indicators, global algorithm, contact and friction); rupture mechanics (G energy restitution level, restitution level in thermo-elasto-plasticity, 3D local energy restitution level, KI and KII stress intensity factors, calculation of limit loads for structures), specific treatments (fatigue, rupture, wear, error estimation); meshes and models (mesh generation, modeling, loads and boundary conditions, links between different modeling processes, resolution of linear systems, display of results etc..); vibration mechanics (modal and harmonic analysis, dynamics with shocks, direct transient dynamics, seismic analysis and aleatory dynamics, non-linear dynamics, dynamical sub-structuring); fluid-structure interactions (internal acoustics, mass, rigidity and damping); linear and non-linear thermal analysis; steels and metal industry (structure transformations); coupled problems (internal chaining, internal thermo-hydro-mechanical coupling, chaining with other codes); products and services. (J.S.)

  10. Fast detection of covert visuospatial attention using hybrid N2pc and SSVEP features

    Science.gov (United States)

    Xu, Minpeng; Wang, Yijun; Nakanishi, Masaki; Wang, Yu-Te; Qi, Hongzhi; Jung, Tzyy-Ping; Ming, Dong

    2016-12-01

    Objective. Detecting the shift of covert visuospatial attention (CVSA) is vital for gaze-independent brain-computer interfaces (BCIs), which might be the only communication approach for severely disabled patients who cannot move their eyes. Although previous studies had demonstrated that it is feasible to use CVSA-related electroencephalography (EEG) features to control a BCI system, the communication speed remains very low. This study aims to improve the speed and accuracy of CVSA detection by fusing EEG features of N2pc and steady-state visual evoked potential (SSVEP). Approach. A new paradigm was designed to code the left and right CVSA with the N2pc and SSVEP features, which were then decoded by a classification strategy based on canonical correlation analysis. Eleven subjects were recruited to perform an offline experiment in this study. Temporal waves, amplitudes, and topographies for brain responses related to N2pc and SSVEP were analyzed. The classification accuracy derived from the hybrid EEG features (SSVEP and N2pc) was compared with those using the single EEG features (SSVEP or N2pc). Main results. The N2pc could be significantly enhanced under certain conditions of SSVEP modulations. The hybrid EEG features achieved significantly higher accuracy than the single features. It obtained an average accuracy of 72.9% by using a data length of 400 ms after the attention shift. Moreover, the average accuracy reached ˜80% (peak values above 90%) when using 2 s long data. Significance. The results indicate that the combination of N2pc and SSVEP is effective for fast detection of CVSA. The proposed method could be a promising approach for implementing a gaze-independent BCI.

  11. Network Coding

    Indian Academy of Sciences (India)

    Network coding is a technique to increase the amount of information °ow in a network by mak- ing the key observation that information °ow is fundamentally different from commodity °ow. Whereas, under traditional methods of opera- tion of data networks, intermediate nodes are restricted to simply forwarding their incoming.

  12. Coding Class

    DEFF Research Database (Denmark)

    Ejsing-Duun, Stine; Hansbøl, Mikala

    Denne rapport rummer evaluering og dokumentation af Coding Class projektet1. Coding Class projektet blev igangsat i skoleåret 2016/2017 af IT-Branchen i samarbejde med en række medlemsvirksomheder, Københavns kommune, Vejle Kommune, Styrelsen for IT- og Læring (STIL) og den frivillige forening...... Coding Pirates2. Rapporten er forfattet af Docent i digitale læringsressourcer og forskningskoordinator for forsknings- og udviklingsmiljøet Digitalisering i Skolen (DiS), Mikala Hansbøl, fra Institut for Skole og Læring ved Professionshøjskolen Metropol; og Lektor i læringsteknologi, interaktionsdesign......, design tænkning og design-pædagogik, Stine Ejsing-Duun fra Forskningslab: It og Læringsdesign (ILD-LAB) ved Institut for kommunikation og psykologi, Aalborg Universitet i København. Vi har fulgt og gennemført evaluering og dokumentation af Coding Class projektet i perioden november 2016 til maj 2017...

  13. Network Coding

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 7. Network Coding. K V Rashmi Nihar B Shah P Vijay Kumar. General Article Volume 15 Issue 7 July 2010 pp 604-621. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/015/07/0604-0621. Keywords.

  14. Expander Codes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 1. Expander Codes - The Sipser–Spielman Construction. Priti Shankar. General Article Volume 10 ... Author Affiliations. Priti Shankar1. Department of Computer Science and Automation, Indian Institute of Science Bangalore 560 012, India.

  15. Evaluation of cytotoxic effects of atrazine and glyphosate herbicides on Biomphalaria glabrata snails

    OpenAIRE

    Mona, Mohamed H.; Gaafar, Reda M.; Helal, Ibrahim B.; Omran, Nahla E.; Salama, Wesam M.

    2013-01-01

    Biomphalaria glabrata snails were used as bio-indicators for freshwater, atrazine, and glyphosate herbicides. SDS–PAGE protein profiles of B. glabrata snails, isozyme analysis (α- and β-esterase, peroxidase and catalase) and RAPD-PCR were used to detect the genotoxicity caused by the two tested herbicides. SDS–PAGE protein profiles showed bands with different molecular weights (53–220 and 1.82–12.5 KDa). The low molecular weight bands appeared in all treated groups except those exposed to 5 p...

  16. CLIPS - C LANGUAGE INTEGRATED PRODUCTION SYSTEM (IBM PC VERSION)

    Science.gov (United States)

    Riley, G.

    1994-01-01

    The C Language Integrated Production System, CLIPS, is a shell for developing expert systems. It is designed to allow artificial intelligence research, development, and delivery on conventional computers. The primary design goals for CLIPS are portability, efficiency, and functionality. For these reasons, the program is written in C. CLIPS meets or outperforms most micro- and minicomputer based artificial intelligence tools. CLIPS is a forward chaining rule-based language. The program contains an inference engine and a language syntax that provide a framework for the construction of an expert system. It also includes tools for debugging an application. CLIPS is based on the Rete algorithm, which enables very efficient pattern matching. The collection of conditions and actions to be taken if the conditions are met is constructed into a rule network. As facts are asserted either prior to or during a session, CLIPS pattern-matches the number of fields. Wildcards and variables are supported for both single and multiple fields. CLIPS syntax allows the inclusion of externally defined functions (outside functions which are written in a language other than CLIPS). CLIPS itself can be embedded in a program such that the expert system is available as a simple subroutine call. Advanced features found in CLIPS version 4.3 include an integrated microEMACS editor, the ability to generate C source code from a CLIPS rule base to produce a dedicated executable, binary load and save capabilities for CLIPS rule bases, and the utility program CRSV (Cross-Reference, Style, and Verification) designed to facilitate the development and maintenance of large rule bases. Five machine versions are available. Each machine version includes the source and the executable for that machine. The UNIX version includes the source and binaries for IBM RS/6000, Sun3 series, and Sun4 series computers. The UNIX, DEC VAX, and DEC RISC Workstation versions are line oriented. The PC version and the Macintosh

  17. Accounting, from rock to standards IBM PC

    OpenAIRE

    Hora, Michal

    2016-01-01

    This paper focuses on the historical evolution of computing tools from ancient antiquity to the personal computer, the IBM PC standard. It describes the first computing devices, the first mechanical calculating machines to store data. It has also captured the dramatic development of calculating machines in the second half of the twentieth century.

  18. Investigasi Serangan Malware Njrat Pada PC

    Directory of Open Access Journals (Sweden)

    Devi Rizky Septiani

    2016-12-01

    Full Text Available Malware merupakan salah satu bentuk dari kejahatan komputer yang terjadi pada sebuah sistem jaringan komputer, malware Njrat termasuk jenis Trojan horse. Trojan adalah salah satu jenis malware yang ikut berkembang di dalamnya, yang memungkinkan attacker masuk ke dalam sistem tanpa diketahui oleh pemilik. Penggunaan trojan saat ini lebih ke arah kejahatan dunia maya (cyber crime, salah satu dari malware yang sangat berbahaya karena besarnya dampak kerugian yang ditimbulkan, mulai dari pencurian data penting sampai mengubah hak akses pada PC korban. Sasaran terbanyak penybaran trojan adalah pengguna sistem operasi windows. Penyebaran trojan ini dilakukan dengan metode social engineering, yaitu teknik yang menggunakan kelemahan manusia, sehingga user tanpa curiga langsung mengeksekusi sebuah program yang tidak dikenal.  Aktivitas malware berkaitan erat dengan  performa PC dan juga aktifitas network pada system computer. Penelitian ini bertujuan untuk mengetahui cara kerja malware Njrat dan melakukan investigasi terhadap performa pada system computer. Metodologi yang digunakan dynamic analysis dengan melakukan analisa malware pada suatu sistem dan melihat aktivitas atau proses yang diaktifkan oleh malware tersebut. Dampak perubahan yang terjadi pada PC Target terlihat pada performa masing-masing PC yang telah disisipkan malware. Kata kunci            Malware, Njrat, System computer

  19. An Automation Interface for Kappa PC

    DEFF Research Database (Denmark)

    Hartvig, Susanne C

    1999-01-01

    The reports documents an automation interface for Kappa PC. The automation interface can be used to embed Kappa applications in 32-bit Windowsapplications.The interface includes functions for initialising Kappa, for loading an application, for settingvalues, for getting values, and for stopping...

  20. Brugervejledning til pc-programmet STLRAMME

    DEFF Research Database (Denmark)

    Buhelt, M.

    Pc-programmet STLRAMME supplerer SBI-anvisning 187, 'Simple stålrammebygninger. Dimensionering og udførelse'. Programmet kan anvendes til dimensionering af stålrammebygninger med andre mål end dem, der er medtaget i anvisningens tabeller; men det erstatter kun stålramme- og åsetabellerne, ikke an...

  1. Combined in utero and juvenile exposure of mice to arsenate and atrazine in drinking water modulates gene expression and clonogenicity of myeloid progenitors.

    Science.gov (United States)

    Cimino-Reale, Graziella; Ferrario, Daniele; Casati, Barbara; Brustio, Roberta; Diodovich, Cristina; Collotta, Angelo; Vahter, Marie; Gribaldo, Laura

    2008-07-30

    The effects of arsenate (As) and atrazine (Atr) on myeloid progenitors (colony-forming unit-granulocyte/macrophage, CFU-GM) cells derived from bone marrow were studied in male and female mice after combined in utero and juvenile exposure. Female adult mice were treated with arsenate in drinking water during gestation. Then, separate groups of males and females' offspring were exposed for 4 months to atrazine, to additional arsenate or to co-exposure of atrazine and arsenate together in drinking water. In male mice, arsenate and the combined exposure did not modulate the percentage of CFU-GM progenitors, whereas atrazine significantly decreases the clonogenicity of myeloid cells. In females, the percentage of CFU-GM significantly decreased after atrazine exposure did not change with arsenate treatment, but dramatically increased after the combined exposure. The expression of estrogen receptors alpha (ERalpha) and beta (ERbeta) in bone marrow cells was investigated, and an up-regulation of receptor beta was observed in both genders. A gene expression profile was generated using nylon membranes spotted with 1185 cancer-related genes. Results from microarrays indicate that atrazine alone did not stimulate the expression of any of the genes analysed in both male and female. Arsenic induced gene expression modulation only in female. Major significant changes on the gene expression resulted following the co-exposure to arsenic and atrazine in both male and female.

  2. Polar Codes

    Science.gov (United States)

    2014-12-01

    added by the decoder is K/ρ+Td. By the last assumption, Td and Te are both ≤ K/ρ, so the total latency added is between 2K/ρ and 4K /ρ. For example...better resolution near the decision point. Reference [12] showed that in decoding a (1024, 512) polar code, using 6-bit LLRs resulted in per- formance

  3. Acetylcholinesterase in honey bees (Apis mellifera) exposed to neonicotinoids, atrazine and glyphosate: laboratory and field experiments.

    Science.gov (United States)

    Boily, Monique; Sarrasin, Benoit; Deblois, Christian; Aras, Philippe; Chagnon, Madeleine

    2013-08-01

    In Québec, as observed globally, abnormally high honey bee mortality rates have been reported recently. Several potential contributing factors have been identified, and exposure to pesticides is of increasing concern. In maize fields, foraging bees are exposed to residual concentrations of insecticides such as neonicotinoids used for seed coating. Highly toxic to bees, neonicotinoids are also reported to increase AChE activity in other invertebrates exposed to sub-lethal doses. The purpose of this study was therefore to test if the honey bee's AChE activity could be altered by neonicotinoid compounds and to explore possible effects of other common products used in maize fields: atrazine and glyphosate. One week prior to pollen shedding, beehives were placed near three different field types: certified organically grown maize, conventionally grown maize or non-cultivated. At the same time, caged bees were exposed to increasing sub-lethal doses of neonicotinoid insecticides (imidacloprid and clothianidin) and herbicides (atrazine and glyphosate) under controlled conditions. While increased AChE activity was found in all fields after 2 weeks of exposure, bees close to conventional maize crops showed values higher than those in both organic maize fields and non-cultivated areas. In caged bees, AChE activity increased in response to neonicotinoids, and a slight decrease was observed by glyphosate. These results are discussed with regard to AChE activity as a potential biomarker of exposure for neonicotinoids.

  4. Banana peel as an adsorbent for removing atrazine and ametryne from waters.

    Science.gov (United States)

    Silva, Claudineia R; Gomes, Taciana F; Andrade, Graziela C R M; Monteiro, Sergio H; Dias, Ana C R; Zagatto, Elias A G; Tornisielo, Valdemar L

    2013-03-13

    The feasibility of using banana peel for removal of the pesticides atrazine and ametryne from river and treated waters has been demonstrated, allowing the design of an efficient, fast, and low-cost strategy for remediation of polluted waters. The conditions for removal of these pesticides in a laboratory scale were optimized as sample volume = 50 mL, banana mass = 3.0 g, stirring time = 40 min, and no pH adjustment necessary. KF(sor) values for atrazine and ametryne were evaluated as 35.8 and 54.1 μg g(-1) (μL mL(-1)) by using liquid scintillation spectrometry. Adsorption was also evaluated by LC-ESI-MS/MS. As quantification limits were 0.10 and 0.14 μg L(-1) for both pesticides, sample preconcentration was not needed. Linear analytical curves (up to 10 μg L(-1)), precise results (RSD 90% removal efficiency were attained for both pesticides. Water samples collected near an intensively cultivated area were adequately remedied.

  5. Atrazine biodegradation modulated by clays and clay/humic acid complexes

    Energy Technology Data Exchange (ETDEWEB)

    Besse-Hoggan, Pascale, E-mail: Pascale.Besse@univ-bpclermont.f [Laboratoire de Synthese et Etude de Systemes a Interet Biologique, UMR-CNRS 6504, Universite Blaise Pascal, 63177 Aubiere Cedex (France); Alekseeva, Tatiana [Institute of Physical, Chemical and Biological Problems of Soil Science, Russian Academy of Sciences, Pushchino, Moscow Region 142290 (Russian Federation); Laboratoire des Materiaux Inorganiques, UMR-CNRS 6002, Universite Blaise Pascal, 63177 Aubiere Cedex (France); Sancelme, Martine; Delort, Anne-Marie [Laboratoire de Synthese et Etude de Systemes a Interet Biologique, UMR-CNRS 6504, Universite Blaise Pascal, 63177 Aubiere Cedex (France); Forano, Claude [Laboratoire des Materiaux Inorganiques, UMR-CNRS 6002, Universite Blaise Pascal, 63177 Aubiere Cedex (France)

    2009-10-15

    The fate of pesticides in the environment is strongly related to the soil sorption processes that control not only their transfer but also their bioavailability. Cationic (Ca-bentonite) and anionic (Layered Double Hydroxide) clays behave towards the ionisable pesticide atrazine (AT) sorption with opposite tendencies: a noticeable sorption capacity for the first whereas the highly hydrophilic LDH showed no interactions with AT. These clays were modified with different humic acid (HA) contents. HA sorbed on the clay surface and increased AT interactions. The sorption effect on AT biodegradation and on its metabolite formation was studied with Pseudomonas sp. ADP. The biodegradation rate was greatly modulated by the material's sorption capacity and was clearly limited by the desorption rate. More surprisingly, it increased dramatically with LDH. Adsorption of bacterial cells on clay particles facilitates the degradation of non-sorbed chemical, and should be considered for predicting pesticide fate in the environment. - The biodegradation rate of atrazine was greatly modulated by adsorption of the pesticide and also bacterial cells on clay particles.

  6. Photolytic destruction of endocrine disruptor atrazine in aqueous solution under UV irradiation: Products and pathways

    Energy Technology Data Exchange (ETDEWEB)

    Chen Cheng [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Yang Shaogui, E-mail: yangdlut@126.com [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Guo Yaping [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Sun Cheng, E-mail: envidean@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Gu Chenggang [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Xu Bin [School of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai (China)

    2009-12-30

    The ultraviolet (UV) photolysis of atrazine in aqueous solution was investigated at wavelength of 254 nm in this study. This paper was mainly focused on the identification of atrazine degradation intermediates by HPLC-MS/MS and its degradation mechanisms. The photodegradation products included the following seven classes: dechloro-hydroxylated products, chloro-dealkylated products, dechloro-dealkylated products, alkylic-oxidated products, delamination-hydroxylated products, olefinic products, and dechloro-hydrogenated products which were never reported in direct photolytic process, 4-isopropylamino-6-ethylamino-s-triazine (IEST), 4,6-dihydroxy-s-triazine (OOST). The main degradation products were 2-hydroxy-4-acetamido-6-ethylamino-s-triazine (OIET), 2-chloro-4-isopropyl-amino-6-methylamino-s-triazine (CIMT), 2-chloro-4,6-divinylamino-s-triazine (CVVT), 2-chloro-4-ethylamino-6-amino-s-triazine(CEAT), 2-methoxy-4-isopropyl-amino-6-methylamino-s-triazine (OIMT), 2-hydroxy-4-acetamindo-6-ethylamino-s-triazine (ODET), etc. Finally, the possible degradation mechanism was also proposed here.

  7. New Technologys in Atrazine Removal from Environment with Emphasis on Biodegradation: A Review

    Directory of Open Access Journals (Sweden)

    Z Derakhshan

    2016-09-01

    Full Text Available Introduction:Considering the lack of agricultural lands and the loss of products by pests, utilization of pesticides like atrazine has increased. Due to low vapor pressure, high half-life, and high mobility, this herbicide results in pollution of different ecosystems. In regard with its toxicity, US Environmental Protection Agency has ranked atrazine in III class. Due to its potential capacity in polluting groundwater, it is highly significant. Methods: Many chemical and physical methods have been introduced to remove this herbicide from soil and water environments; however, these methods involve high expenses and cause the creation of other toxic products. Due to development of the science of interaction between man and nature, nowadays biological treatment is uniquely significant. Biological treatment is a process in which microorganisms are utilized to convert and decompose pollutants existing in the environment. Conclusion: Biodegradation is economically and environmentally the best approach to remove long-standing pollutants from the environment. Nowadays, genetic engineering extensively utilizes local or modified microorganisms in treating the environments polluted with pesticides. Finally, in order to further utilize this green technology, it is necessary to specify the soil properties and also conduct ecotoxicological studies in order to identify the capacity of local microorganisms of water and soil.

  8. Green Tea Protects Testes against Atrazine-induced Toxicity in Rat

    Directory of Open Access Journals (Sweden)

    Reza Kheirandish

    2017-06-01

    Full Text Available Background: Atrazine (ATZ is a common herbicide in agriculture for control of grass and broad-leaved weeds. It persists in the environment and causes reproductive problems in both human and animals. The present study was aimed at protective effect of green tea against ATZ toxicity in the reproductive system of male rats. Methods: The present study was performed in Veterinary School, Shahid Bahonar University of Kerman in 2016. ATZ and treatment groups received ATZ daily 200 mg/kg BW orally for 14 d. In addition, 0.2% methanolic green tea extract was administrated in the treatment group. Results: In histopathologic investigation, number of germinal layers reduced in the most seminiferous tubules in the ATZ group and spermatids were absence. Necrotic spermatocytes, spermatids, and spermatozoa were evident in the testicular tubules. In the morphometric measurements, tubular diameter, germinal epithelium height, and meiosis index decreased significantly. Conclusion: Green tea extract had reduced testicular toxicity of atrazine significantly. ATZ induces toxicity through oxidative damage and green tea extract can protect the testes due to antioxidant activity of its polyphenols especially flavonoids.

  9. Degradation rates of alachlor, atrazine and bentazone in the profiles of Polish Luvisols

    Science.gov (United States)

    Paszko, Tadeusz; Muszyński, Paweł

    2017-07-01

    The degradation rates of three herbicides (alachlor, atrazine, and bentazone) were examined according to OECD Guideline 307 in three profiles of grey-brown podzolic soil (Luvisol) in a laboratory experiment. The aim of the experiment was to determine herbicide degradation parameters and their relationships with soil properties. Degradation processes were effectively described by a first-order model. However, in some cases, the best results were produced by bi-phasic kinetics (hockey-stick and bi-exponential model). The degradation rates of the tested herbicides at 25°C and 40% maximum water holding capacity, established based on half-life values in the Ap horizon, increased in the following order: atrazine (32.6-42.8 days) < bentazone (3.4-16.6 days < alachlor (4.4-5.7 days). The correlation analysis and the Principal Component Analysis revealed significant positive correlations between the herbicide degradation rates and the organic matter content of soils. The depth-dependent degradation factors obtained for topsoil and two subsoil horizons (1: 0.42: 0.11 - based on average values, and 1: 0.31: 0.12 - based on median values) reflect the degradation abilities of Polish Luvisols. The values noted are soil-specific; therefore, they can also be applied to other pesticides in Polish Luvisols.

  10. Evaluated fate and effects of atrazine and lambda-cyhalothrin in vegetated and unvegetated microcosms.

    Science.gov (United States)

    Bouldin, J L; Farris, J L; Moore, M T; Smith, S; Stephens, W W; Cooper, C M

    2005-10-01

    Contaminants such as nutrients, metals, and pesticides can interact with constructed wetlands and existing drainage ditches used as agricultural best-management practices. Our research has shown that the presence of macrophytes and a hydrologic regime aid in the transfer and transformation of pesticides associated with agricultural runoff. This study consisted of application of both atrazine (triazine herbicide) and lambda-cyhalothrin (pyrethroid insecticide) to vegetated and unvegetated microcosms in order to measure the fate and effects of pesticides applied at suggested field application rates. Exposures focused on monocultures of Ludwigia peploides (water primrose) and Juncus effusus (soft rush). Pesticide sorption was evident through concentrations of atrazine and lambda-cyhalothrin in plant tissue as high as 2461.4 and 86.50 microg/kg, respectively. Toxicity was measured in water from unvegetated microcosms for 28 days and in Chironomus tentans (midge larvae) exposed to sediment collected from 3 h to 56 days in microcosms receiving the pesticide combination. The comparative survival of test organisms in this study suggests that effective mitigation of pesticides from runoff can depend on the macrophyte contact and vegetative attributes associated with ditches. (c) 2005 Wiley Periodicals, Inc.

  11. Phytotoxicity of atrazine, isoproturon, and diuron to submersed macrophytes in outdoor mesocosms

    Energy Technology Data Exchange (ETDEWEB)

    Knauert, Stefanie, E-mail: stefanie.knauert@basf.co [University of Basel, Department of Environmental Sciences, Hebelstrasse 1, 4056 Basel (Switzerland); Singer, Heinz; Hollender, Juliane [Eawag: Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Chemistry, Uberlandstrasse 133, 8600 Duebendorf (Switzerland); Knauer, Katja [University of Basel, Program Sustainability Research, Klingelbergstr. 50, 4056 Basel (Switzerland)

    2010-01-15

    The submersed macrophytes Elodea canadensis, Myriophyllum spicatum and Potamogeton lucens were constantly exposed over a five-week period to environmentally relevant concentrations of atrazine, isoproturon, diuron, and their mixture in outdoor mesocosms. Effects were evaluated investigating photosynthetic efficiency (PE) of the three macrophytes and growth of M. spicatum and E. canadensis. Adverse effects on PE were observed on days 2 and 5 after application. M. spicatum was found to be the more sensitive macrophyte. E. canadensis and P. lucens were less sensitive to atrazine, diuron and the mixture and insensitive to isoproturon. PE of M. spicatum was similarly affected by the single herbicides and the mixture demonstrating concentration addition. Growth of E. canadensis and M. spicatum was not reduced indicating that herbicide exposure did not impair plant development. Although PE measurements turned out to be a sensitive method to monitor PSII herbicides, plant growth remains the more relevant ecological endpoint in risk assessment. - Short-term effects on photosynthesis did not result in growth reduction of submerse macrophytes exposed to PSII inhibitors.

  12. Seasonal detection of atrazine and atzA in man-made waterways receiving agricultural runoff in a subtropical, semi-arid environment (Hidalgo County, Texas, USA).

    Science.gov (United States)

    Cortez, Ibdanelo; Vitek, Christopher J; Persans, Michael W; Lowe, Kristine L

    2017-02-01

    Atrazine is a widely-used herbicide that can impact non-target organisms in the environment but can be biologically degraded by several types of microorganisms. In this study, the gene atzA, which encodes for the initial step in bacterially-mediated atrazine degradation, was used as an indicator of atrazine pollution in agricultural canals located in Hidalgo County, Texas, USA. The concentration of atrazine and atzA were monitored once per month for 12 months during 2010-2011. Atrazine was measured using an enzyme-linked immunosorbent assay; atzA abundance was monitored using Quantitative Polymerase Chain Reaction (Q-PCR) analyses. Abundance of atrazine and atzA were compared with rainy versus dry months and during planting versus non-planting months. Results showed that atrazine levels varied from below detection to 0.43 ppb and were not influenced by precipitation or planting season. Concentrations of the gene atzA were significantly different in rainy versus dry months; during planting versus non-planting times of the year; and in the interaction of precipitation and planting season. The highest concentration of atzA, approx. 4.57 × 10 8 gene copies ml -1 , was detected in July 2010-a rainy, planting month in Hidalgo County, South Texas. However, atrazine was below detection during that month. We conclude that Q-PCR using atzA as an indicator gene is a potential method for monitoring low levels of atrazine pollution in environmental samples.

  13. Bioremediation model for atrazine contaminated agricultural soils using phytoremediation (using Phaseolus vulgaris L.) and a locally adapted microbial consortium.

    Science.gov (United States)

    Madariaga-Navarrete, Alfredo; Rodríguez-Pastrana, Blanca Rosa; Villagómez-Ibarra, José Roberto; Acevedo-Sandoval, Otilio Arturo; Perry, Gregory; Islas-Pelcastre, Margarita

    2017-06-03

    The objective of the present study was to examine a biological model under greenhouse conditions for the bioremediation of atrazine contaminated soils. The model consisted in a combination of phytoremediation (using Phaseolus vulgaris L.) and rhizopheric bio-augmentation using native Trichoderma sp., and Rhizobium sp. microorganisms that showed no inhibitory growth at 10,000 mg L(-1) of herbicide concentration. 33.3 mg of atrazine 50 g(-1) of soil of initial concentration was used and an initial inoculation of 1 × 10(9) UFC mL(-1) of Rhizobium sp. and 1 × 10(5) conidia mL(-1) of Trichoderma sp. were set. Four treatments were arranged: Bean + Trichoderma sp. (B+T); Bean + Rhizobium sp. (BR); Bean + Rhizobium sp. + Trichoderma sp. (B+R+T) and Bean (B). 25.51 mg of atrazine 50 g(-1) of soil (76.63%) was removed by the B+T treatment in 40 days (a = 0.050, Tukey). This last indicate that the proposed biological model and methodology developed is useful for atrazine contaminated bioremediation agricultural soils, which can contribute to reduce the effects of agrochemical abuse.

  14. Survival and precopulatory guarding behavior of Hyalella azteca (Amphipoda) exposed to nitrate in the presence of atrazine.

    Science.gov (United States)

    Pandey, Ram B; Adams, Ginny L; Warren, Laurie W

    2011-05-01

    Nitrate is one of the most commonly detected contaminants found in aquatic systems with other pesticides such as atrazine. The current study examined potential combined effects of nitrate and atrazine on adults of the freshwater amphipod Hyalella azteca, using survival and precopulatory guarding behavior as toxic endpoints. Although significant differences in acute toxicity with nitrate alone and in binary combination with atrazine (200 µg/L) in water-only tests were not consistently observed for each time point, potential biologically relevant trends in the data were observed. Posttest growth and behavioral observations (10-day period) conducted after 96-hour exposure suggested that atrazine and nitrate at these concentrations did not result in delayed effects on H. azteca. However, when test conditions were modified from standard toxicity tests by feeding amphipods, nitrate was found to be more toxic, with a reduction in median lethal concentration (LC50) values of approximately 80%. We also demonstrated that nitrate exhibits a dose-response effect on precopulatory guarding behavior of H. azteca, suggesting that reproductive effects may occur at environmentally relevant concentrations. Copyright © 2011 SETAC.

  15. Detailed positron annihilation lifetime spectroscopic investigation of atrazine imprinted polymers grafted onto PE/PP non-woven fabrics.

    Science.gov (United States)

    Söylemez, Meshude Akbulut; Güven, Olgun

    2018-01-01

    This study presents the preparation of molecularly imprinted matrices by using radiation-induced grafting technique onto polyethylene/polypropylene (PE/PP) non-woven fabrics. Atrazine imprinted polymers were grafted onto PE/PP non-woven fabrics through the use of methacrylic acid (MAA) and ethylene glycol dimethylacrylate (EGDMA) as the functional monomer and crosslinking agent, respectively. Grafted MIPs were characterized by attenuated total reflectance Fourier transform infra-red spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), elemental analysis, scanning electron microscopy (SEM), and positron annihilation lifetime spectroscopy (PALS). The average diameter of free volume holes was determined as 0.612 nm which correlates very well with the size of template molecule atrazine, 0.512 nm. Binding behaviors were investigated against various factors, such as concentration of template molecule, pH, and contact time. Furthermore, the specific selectivity of grafted MIP on non-woven fabric was studied by using other common triazine compounds, such as simazine and metribuzine which show structural similarities to atrazine. The specific binding values for atrazine, simazine, and metribuzine were determined as 40%, 2.5%, and 1.5%, respectively. Copyright © 2017 John Wiley & Sons, Ltd.

  16. Effects of an atrazine, metolachlor, and fipronil mixture on Hyalella azteca (Saussure) in a modified backwater wetland

    Science.gov (United States)

    We examined the toxicity mitigation efficiency of a hydrologically modified backwater wetland amended with a mixture of three pesticides, atrazine, metolachlor, and fipronil, using 96 h survival bioassays with Hyalella azteca. Significant H. azteca 96 h mortality occurred within the first two hours...

  17. A NEW APPROACH FOR CULTURING LEMNA MINOR (DUCKWEED) AND STANDARDIZED METHOD FOR USING ATRAZINE AS A REFERENCE TOXICANT

    Science.gov (United States)

    Lemna minor (Duckweed) is commonly used in aquatic toxicity investigations. Methods for culturing and testing with reference toxicants, such as atrazine, are somewhat variable among researchers. Our goal was to develop standardized methods of culturing and testing for use with L....

  18. Sorption mechanisms of phenanthrene, lindane, and atrazine with various humic acid fractions from a single soil sample.

    Science.gov (United States)

    Wang, Xilong; Guo, Xiaoying; Yang, Yu; Tao, Shu; Xing, Baoshan

    2011-03-15

    The sorption behavior of organic compounds (phenanthrene, lindane, and atrazine) to sequentially extracted humic acids and humin from a peat soil was examined. The elemental composition, XPS and (13)C NMR data of sorbents combined with sorption isotherm data of the tested compounds show that nonspecific interactions govern sorption of phenanthrene and lindane by humic substances. Their sorption is dependent on surface and bulk alkyl carbon contents of the sorbents, rather than aromatic carbon. Sorption of atrazine by these sorbents, however, is regulated by polar interactions (e.g., hydrogen bonding). Carboxylic and phenolic moieties are key components for H-bonding formation. Thermal analysis reveals that sorption of apolar (i.e., phenanthrene and lindane) and polar (i.e., atrazine) compounds by humic substances exhibit dissimilar relationships with condensation and thermal stability of sorption domains, emphasizing the major influence of domain spatial arrangement on sorption of organic compounds with distinct polarity. Results of pH-dependent sorption indicate that reduction in sorption of atrazine by the tested sorbents is more evident than phenanthrene with increasing pH, supporting the dependence of organic compound sorption on its polarity and structure. This study highlights the different interaction mechanisms of apolar and polar organic compounds with humic substances.

  19. Effects of endosulfan, thiamethoxam, and indoxacarb in combination with atrazine on multi-biomarkers in Gammarus kischineffensis.

    Science.gov (United States)

    Demirci, Özlem; Güven, Kemal; Asma, Dilek; Öğüt, Serdal; Uğurlu, Pelin

    2018-01-01

    Studies addressing the toxicity of pesticides towards non-target organisms focus on the median lethal concentration and biochemical response of individual pesticides. However, when determining environmental risks, it is important to test the combined effects of pesticides, such as insecticides and herbicides, which are frequently used together in agricultural areas. Here we aimed to investigate the toxic effects of the combined use of the herbicide atrazine and the insecticides, endosulfan, indoxacarb, and thiamethoxam on Gammarus kischineffensis. To do this, we tested the activities of oxidative stress, detoxification, and neurotoxicity biomarkers. Compared to atrazine alone, we detected higher glutathione-S-transferase, catalase and superoxide dismutase activities (oxidative stress biomarkers) when atrazine was combined with either endosulfan or indoxacarb. However, higher IBR values were determined in organisms where pesticide mixtures were used according to individual use. Based on these results, mixtures of atrazine and other pesticides may cause synergistic effects and may be evidence of increased toxicity and oxidative stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Pilot-scale treatment of atrazine production wastewater by UV/O3/ultrasound: Factor effects and system optimization.

    Science.gov (United States)

    Jing, Liang; Chen, Bing; Wen, Diya; Zheng, Jisi; Zhang, Baiyu

    2017-12-01

    This study shed light on removing atrazine from pesticide production wastewater using a pilot-scale UV/O 3 /ultrasound flow-through system. A significant quadratic polynomial prediction model with an adjusted R 2 of 0.90 was obtained from central composite design with response surface methodology. The optimal atrazine removal rate (97.68%) was obtained at the conditions of 75 W UV power, 10.75 g h -1 O 3 flow rate and 142.5 W ultrasound power. A Monte Carlo simulation aided artificial neural networks model was further developed to quantify the importance of O 3 flow rate (40%), UV power (30%) and ultrasound power (30%). Their individual and interaction effects were also discussed in terms of reaction kinetics. UV and ultrasound could both enhance the decomposition of O 3 and promote hydroxyl radical (OH·) formation. Nonetheless, the dose of O 3 was the dominant factor and must be optimized because excess O 3 can react with OH·, thereby reducing the rate of atrazine degradation. The presence of other organic compounds in the background matrix appreciably inhibited the degradation of atrazine, while the effects of Cl - , CO 3 2- and HCO 3 - were comparatively negligible. It was concluded that the optimization of system performance using response surface methodology and neural networks would be beneficial for scaling up the treatment by UV/O 3 /ultrasound at industrial level. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. RESPONSES OF MOLECULAR INDICATORS OF EXPOSURE IN MESOCOSMS: COMMON CARP (CYPRINUS CARPIO) EXPOSED TO THE HERBICIDES ALACHLOR AND ATRAZINE

    Science.gov (United States)

    Common carp (Cyprinus carpio) were treated in aquatic mesocosms with a single pulse of the herbicides atrazine or alachlor to study the bioavailability and biological activity of these herbicides using molecular indicators: Liver vitellogenin gene expression in male fish for estr...

  2. Characterization of pesticide sorption behaviour of slow pyrolysis biochars as low cost adsorbent for atrazine and imidacloprid removal.

    Science.gov (United States)

    Mandal, Abhishek; Singh, Neera; Purakayastha, T J

    2017-01-15

    Agri-wastes biochars viz. eucalyptus bark (EBBC), corn cob (CCBC), bamboo chips (BCBC), rice husk (RHBC) and rice straw (RSBC) and acid treated RSBC (T-RSBC), were characterized for their physico-chemical properties and sorption behaviour of atrazine and imidacloprid was studied. Kinetics study suggested that except atrazine adsorption on RSBC, which was best explained by the pseudo second order model, sorption of atrazine and imidacloprid on biochars was well explained by the modified Elovich model. Among the five normal biochars, the RSBC showed the maximum atrazine (37.5-70.7%) and imidacloprid (39.9-77.8%) sorption. The phosphoric acid treatment of RSBC further enhanced the sorption of both pesticides in T-RSBC. The Freundlich adsorption isotherms were highly nonlinear and percent adsorption decreased with increase in pesticide concentration in solution. Pesticide adsorption on biochars was affected by their aromaticity, polarity, pore diameter, pH and weak acid fraction. Thus, rice straw biochars have great potential for environmental implications and can be exploited as adsorbents for pesticide industry spewed waste water purification. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Experimental-design-guided approach for the removal of atrazine by sono-electrochemical-UV-chlorine techniques.

    Science.gov (United States)

    Pinto, Camila Ferreira; Antonelli, Raissa; de Araújo, Karla Santos; Fornazari, Ana Luiza de Toledo; Fernandes, David Maikel; Granato, Ana Claudia; Azevedo, Eduardo Bessa; Malpass, Geoffroy Roger Pointer

    2017-11-02

    The aim of the present study was to investigate the electrochemical formation of free chlorine species (HOCl/ClO(-)) and their subsequent use for the degradation of the pesticide atrazine. Initially, the process of electrochemical-free chlorine production was investigated using a bench-scale electrochemical flow-cell. The most significant variables (electrolyte concentration ([NaCl]) and inter-electrode gap) of the process were obtained using a 2(3) factorial design and the optimum process conditions (1.73 mol L(-1) and 0.56 cm) were determined by a central composite design. Following optimization of free chlorine production, three degradation techniques were investigated, individually and in combination, for atrazine degradation: electrochemical, photochemical and sonochemical. The method using the techniques in combination was denominated sono-photo-assisted electrochemical degradation. Constant current assays were performed and the sono-photo-assisted electrochemical process promoted more efficient removal of atrazine, achieving total organic carbon removal of ∼98% and removal of atrazine to levels below the detection limit (>99%) in under 30 min of treatment. Furthermore, the combination of three techniques displayed lower energy consumption, and phytotoxicity tests (Lactuca sativa) showed that there was no increase in toxicity.

  4. Organic matter in four Brazilian soil types: chemical composition and atrazine sorption; Materia organica em quatro tipos de solos brasileiros: composicao quimica e sorcao de atrazina

    Energy Technology Data Exchange (ETDEWEB)

    Dick, Deborah Pinheiro [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. de Quimica. Dept. de Fisico-quimica; Martinazzo, Rosane [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Faculdade de Agronomia. Dept. de Solos; Knicker, Heike [Technische Universitaet Muenchen, Freising (Germany). Lehrstuhl fuer Bodenkunde; Almeida, Paulo Sergio Gois [Centro de Ensino Superior de Rondonopolis, MT (Brazil)

    2010-07-01

    Soil organic matter is the main sorptive soil compartment for atrazine in soils, followed in a minor scale by the inorganic fraction. In this study, the soil organic matter quality and atrazine sorption were investigated in four different soil types. The pedogenic environment affected the humification and therefore the chemical composition of the organic matter. The organic matter contribution to atrazine sorption was larger (60-83%) than that of the inorganic fraction. The organic matter capacity in retaining the herbicide was favoured by a higher decomposition degree and a smaller carboxylic substitution of the aliphatic chains. (author)

  5. Convolutional-Code-Specific CRC Code Design

    OpenAIRE

    Lou, Chung-Yu; Daneshrad, Babak; Wesel, Richard D.

    2015-01-01

    Cyclic redundancy check (CRC) codes check if a codeword is correctly received. This paper presents an algorithm to design CRC codes that are optimized for the code-specific error behavior of a specified feedforward convolutional code. The algorithm utilizes two distinct approaches to computing undetected error probability of a CRC code used with a specific convolutional code. The first approach enumerates the error patterns of the convolutional code and tests if each of them is detectable. Th...

  6. Exposure to atrazine affects the expression of key genes in metabolic pathways integral to energy homeostasis in Xenopus laevis tadpoles

    Energy Technology Data Exchange (ETDEWEB)

    Zaya, Renee M., E-mail: renee.zaya@wmich.edu [Great Lakes Environmental and Molecular Sciences Center, Department of Biological Sciences, 3425 Wood Hall, Western Michigan University, 1903 West Michigan Avenue, Kalamazoo, MI 49008 (United States); Amini, Zakariya, E-mail: zakariya.amini@wmich.edu [Great Lakes Environmental and Molecular Sciences Center, Department of Biological Sciences, 3425 Wood Hall, Western Michigan University, 1903 West Michigan Avenue, Kalamazoo, MI 49008 (United States); Whitaker, Ashley S., E-mail: ashley.s.whitaker@wmich.edu [Great Lakes Environmental and Molecular Sciences Center, Department of Biological Sciences, 3425 Wood Hall, Western Michigan University, 1903 West Michigan Avenue, Kalamazoo, MI 49008 (United States); Ide, Charles F., E-mail: charles.ide@wmich.edu [Great Lakes Environmental and Molecular Sciences Center, Department of Biological Sciences, 3425 Wood Hall, Western Michigan University, 1903 West Michigan Avenue, Kalamazoo, MI 49008 (United States)

    2011-08-15

    In our laboratory, Xenopus laevis tadpoles exposed throughout development to 200 or 400 {mu}g/L atrazine, concentrations reported to periodically occur in puddles, vernal ponds and runoff soon after application, were smaller and had smaller fat bodies (the tadpole's lipid storage organ) than controls. It was hypothesized that these changes were due to atrazine-related perturbations of energy homeostasis. To investigate this hypothesis, selected metabolic responses to exposure at the transcriptional and biochemical levels in atrazine-exposed tadpoles were measured. DNA microarray technology was used to determine which metabolic pathways were affected after developmental exposure to 400 {mu}g/L atrazine. From these data, genes representative of the affected pathways were selected for assay using quantitative real time polymerase chain reaction (qRT-PCR) to measure changes in expression during a 2-week exposure to 400 {mu}g/L. Finally, ATP levels were measured from tadpoles both early in and at termination of exposure to 200 and 400 {mu}g/L. Microarray analysis revealed significant differential gene expression in metabolic pathways involved with energy homeostasis. Pathways with increased transcription were associated with the conversion of lipids and proteins into energy. Pathways with decreased transcription were associated with carbohydrate metabolism, fat storage, and protein synthesis. Using qRT-PCR, changes in gene expression indicative of an early stress response to atrazine were noted. Exposed tadpoles had significant decreases in acyl-CoA dehydrogenase (AD) and glucocorticoid receptor protein (GR) mRNA after 24 h of exposure, and near-significant (p = 0.07) increases in peroxisome proliferator-activated receptor {beta} (PPAR-{beta}) mRNA by 72 h. Decreases in AD suggested decreases in fatty acid {beta}-oxidation while decreases in GR may have been a receptor desensitization response to a glucocorticoid surge. Involvement of PPAR-{beta}, an energy

  7. Carbon and nitrogen isotope analysis of atrazine and desethylatrazine at sub-microgram per liter concentrations in groundwater.

    Science.gov (United States)

    Schreglmann, Kathrin; Hoeche, Martina; Steinbeiss, Sibylle; Reinnicke, Sandra; Elsner, Martin

    2013-03-01

    Environmental degradation of organic micropollutants is difficult to monitor due to their diffuse and ubiquitous input. Current approaches-concentration measurements over time, or daughter-to-parent compound ratios-may fall short, because they do not consider dilution, compound-specific sorption characteristics or alternative degradation pathways. Compound-specific isotope analysis (CSIA) offers an alternative approach based on evidence from isotope values. Until now, however, the relatively high limits for precise isotope analysis by gas chromatography-isotope ratio mass spectrometry (GC-IRMS) have impeded CSIA of sub-microgram-per-liter scale micropollutant concentrations in field samples. This study presents the first measurements of C and N isotope ratios of the herbicide atrazine and its metabolite desethylatrazine at concentrations of 100 to 1,000 ng/L in natural groundwater samples. Solid-phase extraction and preparative HPLC were tested and validated for preconcentration and cleanup of groundwater samples of up to 10 L without bias by isotope effects. Matrix interferences after solid-phase extraction could be greatly reduced by a preparative HPLC cleanup step prior to GC-IRMS analysis. Sensitivity was increased by a factor of 6 to 8 by changing the injection method from large-volume to cold-on-column injection on the GC-IRMS system. Carbon and nitrogen isotope values of field samples showed no obvious correlation with concentrations or desethylatrazine-to-atrazine ratios. Contrary to expectations, however, δ (13) C values of desethylatrazine were consistently less negative than those of atrazine from the same sites. Potentially, this line of evidence may contain information about further desethylatrazine degradation. In such a case, the common practice of using desethylatrazine-to-atrazine ratios would underestimate natural atrazine degradation.

  8. Differential metamorphosis alters the endocrine response in anuran larvae exposed to T{sub 3} and atrazine

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, Jennifer L. [University of Illinois, Department of Crop Sciences, 1201 W. Gregory Drive, 320 ERML, Urbana, IL 61801 (United States); Beccue, Nathan [University of Illinois, Department of Crop Sciences, 1201 W. Gregory Drive, 320 ERML, Urbana, IL 61801 (United States); Rayburn, A. Lane [University of Illinois, Department of Crop Sciences, 1201 W. Gregory Drive, 320 ERML, Urbana, IL 61801 (United States)]. E-mail: arayburn@uiuc.edu

    2005-11-10

    Pesticide chemical contamination is one of the suspected contributors of the amphibian population decline. The herbicide atrazine is one of the major surface water contaminants in the U.S. A previous study has shown that atrazine at concentrations as low as 100 parts per billion (ppb) increased the time to metamorphosis in Xenopus laevis tadpoles. However, questions remain as to the applicability of a study of a non-native species to a native organism. The possible effects of atrazine on developing Bufo americanus were explored. Atrazine at potentially (albeit high) environmental concentrations was found not to delay the metamorphosis of developing B. americanus tadpoles as observed in X. laevis. Several studies have indicated that atrazine affects thyroid hormones. Since thyroid hormones are critical in amphibian metamorphosis, B. americanus and X. laevis tadpoles were exposed to exogenous 3,5,3'-triiodothyronine (T{sub 3}). X. laevis were found to be more responsive to the effects of exogenous T{sub 3} compared to B. americanus, indicating that X. laevis may be more sensitive to endocrine active chemicals than B. americanus. In X. laevis, nuclear heterogeneity has been associated with metamorphosis. Flow cytometric analysis of the nuclei of normal metamorphing B. americanus indicates a decrease in the amount of thyroid mediated chromatin alterations relative to the nuclei of metamorphing X. laevis. Indications are that the differential response to endocrine disruption is due to the differential role of chromatin associated gene expression during metamorphosis of B. americanus versus X. laevis. A second native species, Hyla versicolor, was observed to have the X. laevis nuclear pattern with respect to metamorphosis. As such, sensitivity to endocrine disruption is hypothesized not to be limited to laboratory non-native species.

  9. Characterization of spectral responses of dissolved organic matter (DOM) for atrazine binding during the sorption process onto black soil.

    Science.gov (United States)

    Wang, Yifan; Zhang, Xinyuan; Zhang, Xing; Meng, Qingjuan; Gao, Fengjie; Zhang, Ying

    2017-08-01

    This study was aim to investigate the interaction between soil-derived dissolved organic matter (DOM) and atrazine as a kind of pesticides during the sorption process onto black soil. According to the experimental data, the adsorption capacity of Soil + DOM, Soil and DOM were 41.80, 31.45 and 9.35 mg kg(-1), separately, which indicated that DOM significantly enhanced the adsorption efficiency of atrazine by soil. Data implied that the pseudo-second-order kinetic equation could well explain the adsorption process. The adsorption isotherms (R(2) > 0.99) had a satisfactory fit in both Langmuir and Freundlich models. Three-dimensional excitation-emission matrix (3D-EEM), synchronous fluorescence, two-dimensional correlation spectroscopy (2D-COS) and Fourier transform infrared spectroscopy (FT-IR) were selected to analyze the interaction between DOM and atrazine. 3D-EEM showed that humic acid-like substances were the main component of DOM. The fluorescence of DOM samples were gradually quenched with the increased of atrazine concentrations. Synchronous fluorescence spectra showed that static fluorescence quenching was the main quenching process. 2D-COS indicated that the order of the spectral changes were as following: 336 nm > 282 nm. Furthermore, the fluorescence quenching of humic-like fraction occurred earlier than that of protein-like fraction under atrazine surroundings. FT-IR spectra indicated that main compositions of soil DOM include proteins, polysaccharides and humic substances. The findings of this study are significant to reveal DOM played an important role in the environmental fate of pesticides during sorption process onto black soil and also provide more useful information for understanding the interaction between DOM and pesticides by using spectral responses. Copyright © 2017. Published by Elsevier Ltd.

  10. PC12 differentiation on biopolymer nanostructures

    Science.gov (United States)

    Cecchini, Marco; Bumma, Giorgia; Serresi, Michela; Beltram, Fabio

    2007-12-01

    The study of nervous system regeneration and axonal outgrowth control are relevant in several research areas, like neurophysiology or biomedical engineering. Among the elements that control neuron dynamics, the host substrate topography is a key parameter in determining cell differentiation. We present time-lapse experiments to analyze the differentiation dynamics of PC12 cells on nanopatterned biocompatible substrates. 200 nm depth gratings were fabricated on tissue-culture polystyrene substrates by nanoimprint lithography; different linewidths and pitches were compared down to 500 nm and 1000 nm, respectively. PC12 cells were cultured on these substrates and, following NGF administration to the medium, body morphology, cell movement and neuritogenesis were monitored at different time periods. In addition to demonstrating guided differentiation, our studies show complex time variations in body morphology and axon length, and guided cell movement. We show unstable synaptic connections and cell-body polarization, and the competition between topographical guidance and cell-cell interactions.

  11. PC12 polarity on biopolymer nanogratings

    Energy Technology Data Exchange (ETDEWEB)

    Cecchini, M; Ferrari, A; Beltram, F [Scuola Normale Superiore and NEST-CNR-INFM, Pisa (Italy); Scuola Normale Superiore and Italian Institute of Technology, Pisa (Italy)], E-mail: m.cecchini@sns.it

    2008-03-15

    Cell differentiation properties are strongly entangled with the morphology and physical properties of the extracellular environment. A complete understanding of this interaction needs artificial scaffolds with controlled nano-/micro-topography. We induced specific topographies by nanoimprint lithography (NIL) on tissue culture polystyrene (TCPS) dishes substrates and, using light microscopy and high-magnification scanning-electron-microscopy, quantitatively compared the changes in PC12 differentiation phenotype induced by the periodicity of the nanopatterns. This analysis revealed that nanogratings reduce the number of neurites produced by PC12 cells upon treatment with NGF and that neuronal bipolarity correlated with an increased stretching of the cell body and a reduced length of the cell neuronal protrusions.

  12. Pc3 pulsations during variable IMF conditions

    Directory of Open Access Journals (Sweden)

    U. Villante

    1999-04-01

    Full Text Available Pc3 geomagnetic field fluctuations detected at low latitude (L'Aquila, Italy during the passage of a high velocity solar wind stream, characterized by variable interplanetary magnetic field conditions, are analyzed. Higher frequency resonant fluctuations and lower frequency phenomena are simultaneously observed; the intermittent appearance and the variable frequency of the longer period modes can be well interpreted in terms of the variable IMF elements; moreover their polarization characteristics are consistent with an origin related to external waves propagating in antisunward direction. A comparison with simultaneous observations performed at Terra Nova Bay (Antarctica provides additional evidence for a clear relationship between the IMF and Pc3 pulsations also at very high latitudes.Key words. Magnetospheric physics (MHD waves and instabilities; solar wind · magnetosphere interactions

  13. Pc3 pulsations during variable IMF conditions

    Directory of Open Access Journals (Sweden)

    U. Villante

    Full Text Available Pc3 geomagnetic field fluctuations detected at low latitude (L'Aquila, Italy during the passage of a high velocity solar wind stream, characterized by variable interplanetary magnetic field conditions, are analyzed. Higher frequency resonant fluctuations and lower frequency phenomena are simultaneously observed; the intermittent appearance and the variable frequency of the longer period modes can be well interpreted in terms of the variable IMF elements; moreover their polarization characteristics are consistent with an origin related to external waves propagating in antisunward direction. A comparison with simultaneous observations performed at Terra Nova Bay (Antarctica provides additional evidence for a clear relationship between the IMF and Pc3 pulsations also at very high latitudes.

    Key words. Magnetospheric physics (MHD waves and instabilities; solar wind · magnetosphere interactions

  14. PC Based wireless stepper motor control

    OpenAIRE

    Jamal, Omar; Khan, Shahnawaz; Abideen, Zainul

    2013-01-01

    This project is about making an embedded system in order to control different functionalities of a stepper motor. The main functions of this stepper motor are to control the speed and direction. The whole hardware consists of two parts. One is the transmitter side and the other side is the receiver side. The transmitter side consists of PC, Encoder, a microcontroller and RF (Radio Frequency) transmitter. On the receiver side there is an RF receiver, a decoder, a microcontroller, a motor drive...

  15. From concatenated codes to graph codes

    DEFF Research Database (Denmark)

    Justesen, Jørn; Høholdt, Tom

    2004-01-01

    We consider codes based on simple bipartite expander graphs. These codes may be seen as the first step leading from product type concatenated codes to more complex graph codes. We emphasize constructions of specific codes of realistic lengths, and study the details of decoding by message passing...

  16. Concatenated codes with convolutional inner codes

    DEFF Research Database (Denmark)

    Justesen, Jørn; Thommesen, Christian; Zyablov, Viktor

    1988-01-01

    The minimum distance of concatenated codes with Reed-Solomon outer codes and convolutional inner codes is studied. For suitable combinations of parameters the minimum distance can be lower-bounded by the product of the minimum distances of the inner and outer codes. For a randomized ensemble...... of concatenated codes a lower bound of the Gilbert-Varshamov type is proved...

  17. Data of evolutionary structure change: 1A54A-1PC3B [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1A54A-1PC3B 1A54 1PC3 A B --------EASLTGAGATFPAPVYAKWADTYQKET-GNK...Chain> 1PC3 B 1PC3...CA 355 LEU CA 306 GLY CA 308 GLY CA 333 1PC3... B 1PC3B TVDFPAVP...ne> ALA CA 404 ASN CA 326 1PC3

  18. 39 CFR 501.16 - PC postage payment methodology.

    Science.gov (United States)

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false PC postage payment methodology. 501.16 Section 501.16 Postal Service UNITED STATES POSTAL SERVICE POSTAGE PROGRAMS AUTHORIZATION TO MANUFACTURE AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS § 501.16 PC postage payment methodology. (a) The PC Postage customer is...

  19. A Discussion of Water Pollution in the United States and Mexico; with High School Laboratory Activities for Analysis of Lead, Atrazine, and Nitrate.

    Science.gov (United States)

    Kelter, Paul B.; Grundman, Julie; Hage, David S.; Carr, James D.; Castro-Acuna, Carlos Mauricio

    1997-01-01

    Presents discussions on sources, health impacts, methods of analysis as well as lengthy discussions of lead, nitrates, and atrazine as related to water pollution and the interdisciplinary nature of the modern chemistry curriculum. (DKM)

  20. Atrazine Does Not Induce Pica Behavior at Doses that Increase Hypothalamic-Pituitary-Adrenal Axis Activation and Cause Conditioned Taste Avoidance.

    Science.gov (United States)

    Previous work has shown that a single oral administration of atrazine (ATR), a chlorotriazine herbicide, induces dose-dependent increases in plasma adrenocorticotropic hormone (ACTH), serum corticosterone (CORT) and progesterone. The mechanism for these effects is unknown. To tes...

  1. Atrazine Concentrations in Stream Water and Streambed Sediment Pore Water in the St. Joseph and Galien River Basins, Michigan and Indiana, May 2001 - September 2003

    National Research Council Canada - National Science Library

    Duris, Joseph W; Reeves, Howard W; Kiesler, James L

    2004-01-01

    The U.S. Geological Survey (USGS) sampled multiple stream sites across the St. Joseph and Galien River Basins to detect and quantify the herbicide atrazine using a field enzyme-linked immunosorbent assay (ELISA) triazine test...

  2. Spatial and temporal variation of algal assemblages in six Midwest agricultural streams having varying levels of atrazine and other physicochemical attributes

    Energy Technology Data Exchange (ETDEWEB)

    Andrus, J. Malia, E-mail: andrusm@waterborne-env.com [Waterborne Environmental, Inc., 2001 South First Street, Suite 109, Champaign, IL 61820 (United States); Winter, Diane, E-mail: dwinter1@juno.com [Rhithron Associates, Inc., 33 Fort Missoula Rd., Missoula, MT 59804 (United States); Algal Analysis, LLC, Missoula, MT (United States); Scanlan, Michael, E-mail: mscanlan@maptech-inc.com [MapTech, Inc., 3154 State Street, Blacksburg, VA 24060 (United States); Sullivan, Sean, E-mail: ssullivan@rhithron.com [Rhithron Associates, Inc., 33 Fort Missoula Rd., Missoula, MT 59804 (United States); Bollman, Wease, E-mail: wbollman@rhithron.com [Rhithron Associates, Inc., 33 Fort Missoula Rd., Missoula, MT 59804 (United States); Waggoner, J.B., E-mail: jwaggoner@inovatia.com [Inovatia, Inc., 120 East Davis Street, Fayette, MO 65248 (United States); Hosmer, Alan J., E-mail: alan.hosmer@syngenta.com [Syngenta Crop Protection, LLC, 410 Swing Rd., Greensboro, NC 27419 (United States); Brain, Richard A., E-mail: richard.brain@syngenta.com [Syngenta Crop Protection, LLC, 410 Swing Rd., Greensboro, NC 27419 (United States)

    2015-02-01

    Potential effects of pesticides on stream algae occur alongside complex environmental influences; in situ studies examining these effects together are few, and have not typically controlled for collinearity of variables. We monitored the dynamics of periphyton, phytoplankton, and environmental factors including atrazine, and other water chemistry variables at 6 agricultural streams in the Midwest US from spring to summer of 2011 and 2012, and used variation partitioning of community models to determine the community inertia that is explained uniquely and/or jointly by atrazine and other environmental factors or groups of factors. Periphyton and phytoplankton assemblages were significantly structured by year, day of year, and site, and exhibited dynamic synchrony both between site–years and between periphyton and phytoplankton in the same site–year. The majority of inertia in the models (55.4% for periphyton, 68.4% for phytoplankton) was unexplained. The explained inertia in the models was predominantly shared (confounded) between variables and variable groups (13.3, 30.9%); the magnitude of inertia that was explained uniquely by variable groups (15.1, 18.3%) was of the order hydroclimate > chemistry > geography > atrazine for periphyton, and chemistry > hydroclimate > geography > atrazine for phytoplankton. The variables most influential to the assemblage structure included flow and velocity variables, and time since pulses above certain thresholds of nitrate + nitrite, total phosphorus, total suspended solids, and atrazine. Time since a ≥ 30 μg/L atrazine pulse uniquely explained more inertia than time since pulses ≥ 10 μg/L or daily or historic atrazine concentrations; this result is consistent with studies concluding that the effects of atrazine on algae typically only occur at ≥ 30 μg/L and are recovered from. - Highlights: • We monitored algal communities at 6 Midwest streams receiving atrazine in 2011 and 2012. • Partitioning of CCA models of

  3. Genetic algorithms with permutation coding for multiple sequence alignment.

    Science.gov (United States)

    Ben Othman, Mohamed Tahar; Abdel-Azim, Gamil

    2013-08-01

    Multiple sequence alignment (MSA) is one of the topics of bio informatics that has seriously been researched. It is known as NP-complete problem. It is also considered as one of the most important and daunting tasks in computational biology. Concerning this a wide number of heuristic algorithms have been proposed to find optimal alignment. Among these heuristic algorithms are genetic algorithms (GA). The GA has mainly two major weaknesses: it is time consuming and can cause local minima. One of the significant aspects in the GA process in MSA is to maximize the similarities between sequences by adding and shuffling the gaps of Solution Coding (SC). Several ways for SC have been introduced. One of them is the Permutation Coding (PC). We propose a hybrid algorithm based on genetic algorithms (GAs) with a PC and 2-opt algorithm. The PC helps to code the MSA solution which maximizes the gain of resources, reliability and diversity of GA. The use of the PC opens the area by applying all functions over permutations for MSA. Thus, we suggest an algorithm to calculate the scoring function for multiple alignments based on PC, which is used as fitness function. The time complexity of the GA is reduced by using this algorithm. Our GA is implemented with different selections strategies and different crossovers. The probability of crossover and mutation is set as one strategy. Relevant patents have been probed in the topic.

  4. IBM PC/IX operating system evaluation plan

    Science.gov (United States)

    Dominick, Wayne D. (Editor); Granier, Martin; Hall, Philip P.; Triantafyllopoulos, Spiros

    1984-01-01

    An evaluation plan for the IBM PC/IX Operating System designed for IBM PC/XT computers is discussed. The evaluation plan covers the areas of performance measurement and evaluation, software facilities available, man-machine interface considerations, networking, and the suitability of PC/IX as a development environment within the University of Southwestern Louisiana NASA PC Research and Development project. In order to compare and evaluate the PC/IX system, comparisons with other available UNIX-based systems are also included.

  5. Synthesis of high-purity phthalocyanines (pc): High intrinsic conductivities in the molecular conductors H[sub 2](pc)I and Ni(pc)I

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, J.A.; Murata, K.; Miller, D.C.; Stanton, J.L.; Broderick, W.E.; Hoffman, B.M.; Ibers, J.A. (Northwestern Univ., Evanston, IL (United States))

    1993-08-04

    The authors show that one can prepare M(pc)I crystals, M = [open quotes]H[sub 2][close quotes] and Ni, with remarkably improved charge-transport properties by carefully avoiding impurities in the preparation of the M(pc) precursors. The purest H[sub 2](pc) (<60 ppm free-radical impurities) was prepared by a melt method in quartz and Teflon vessels while very pure Ni(pc) (170-250 pm) could only be obtained by metalation of the pure H[sub 2](pc). Template syntheses of Ni(pc) result in impure material and are to be discouraged for applications requiring very pure M(pc) materials. H[sub 2](pc)I and Ni(pc)I synthesized from the high-purity precursors remain metallic down to ca. 3 K, a far lower temperature than ever before observed. At this temperature the conductivities exhibit maximum values that are ca. 30-fold greater than at room temperature, not 5-7-fold as seen before, with absolute values of [sigma] [approximately] (1-2) [times] 10[sup 4] [Omega][sup [minus]1] cm[sup [minus]1]. The study of a series of Ni(pc)I compounds prepared from Ni(pc) parent materials exhibiting a range of purity levels further shows a strong correlation between the charge-transport properties and the level of paramagnetic impurities in the macrocycle precursor. However, the maximum conductivity appears to saturate at the lowest impurity concentrations, which suggests that the behavior exhibited by the best materials prepared are representative for the first time of the limiting, intrinsic charge-transport properties of H[sub 2](pc)I and Ni(pc)I. A full structure report for H[sub 2](pc)I-1 is presented also. The structure consists of metal-over-metal stacks of partially oxidized H[sub 2](pc) groups surrounded by linear chains of triiodide anions. H[sub 2](pc)I crystallizes with two formula units in the tetragonal space group D[sub 4h][sup 2]-P4/mcc with a = 13.931 [angstrom], c = 6.411 [angstrom], and V = 1244.2 [angstrom][sup 3] (T = 108 K).

  6. Effect of fly ash amendment on metolachlor and atrazine degradation and microbial activity in two soils.

    Science.gov (United States)

    Ghosh, Rakesh Kumar; Singh, Neera; Singh, Shashi Bala

    2016-08-01

    The study reports the effect of Inderprastha (IP) and Badarpur (BP) fly ashes on degradation of metolachlor and atrazine in Inceptisol and Alfisol soils. Metolachlor dissipated at faster rate in Alfisol (t1/2 8.2-8.6 days) than in Inceptisol (t1/2 13.2-14.3 days). The fly ashes enhanced the persistence of metolachlor in both the soils; however, the extent of effect was more in Inceptisol (t1/2 16.6-33.8 days) than Alfisol (t1/2 8.4-12 days) and effect increased with fly ash dose. 2-Ethyl-6-methylacetanilide was detected as the only metabolite of metolachlor. Atrazine was more persistent in flooded soils (t1/2 10.8-20.3 days) than nonflooded soils (t1/2 3.7-12.6 days) and fly ash increased its persistence, but effect was more pronounced in the flooded Inceptisol (t1/2 23.7-31 days) and nonflooded Alfisol (t1/2 6.3-10.1 days). Increased herbicide sorption in the fly ash-amended soils might have contributed to the increased pesticide persistence. The IP fly ash inhibited microbial biomass carbon at 5 % amendment levels in both the soils, while BP fly ash slightly increased microbial biomass carbon (MBC) content. Dehydrogenase activity was inhibited by both fly ashes in both the soils with maximum inhibition observed in the IP fly ash-amended Alfisol. No significant effect of fly ash amendment was observed on the fluorescein diacetate activity.

  7. Silica gel-encapsulated AtzA biocatalyst for atrazine biodegradation.

    Science.gov (United States)

    Reátegui, Eduardo; Reynolds, Erik; Kasinkas, Lisa; Aggarwal, Amit; Sadowsky, Michael J; Aksan, Alptekin; Wackett, Lawrence P

    2012-10-01

    Encapsulation of recombinant Escherichia coli cells expressing a biocatalyst has the potential to produce stable, long-lasting enzyme activity that can be used for numerous applications. The current study describes the use of this technology with recombinant E. coli cells expressing the atrazine-dechlorinating enzyme AtzA in a silica/polymer porous gel. This novel recombinant enzyme-based method utilizes both adsorption and degradation to remove atrazine from water. A combination of silica nanoparticles (Ludox TM40), alkoxides, and an organic polymer was used to synthesize a porous gel. Gel curing temperatures of 23 or 45 °C were used either to maintain cell viability or to render the cells non-viable, respectively. The enzymatic activity of the encapsulated viable and non-viable cells was high and extremely stable over the time period analyzed. At room temperature, the encapsulated non-viable cells maintained a specific activity between (0.44 ± 0.06) μmol/g/min and (0.66 ± 0.12) μmol/g/min for up to 4 months, comparing well with free, viable cell-specific activities (0.61 ± 0.04 μmol/g/min). Gels cured at 45 °C had excellent structural rigidity and contained few viable cells, making these gels potentially compatible with water treatment facility applications. When encapsulated, non-viable cells were assayed at 4 °C, the activity increased threefold over free cells, potentially due to differences in lipid membranes as shown by FTIR spectroscopy and electron microscopy.

  8. Properties of biochar-amended soils and their sorption of imidacloprid, isoproturon, and atrazine.

    Science.gov (United States)

    Jin, Jie; Kang, Mingjie; Sun, Ke; Pan, Zezhen; Wu, Fengchang; Xing, Baoshan

    2016-04-15

    Biochars produced from rice straw, wheat straw and swine manure at 300, 450 and 600°C were added to soil at 1, 5, 10, or 20% levels to determine whether they would predictably reduce the pore water concentration of imidacloprid, isoproturon, and atrazine. The sorption capacity of the mixtures increased with increasing biochar amounts. The enhanced sorption capacity could be attributed to the increased organic carbon (OC) content and surface area (SA) as well as the decreased hydrophobicity. Biochar dominated the overall sorption when its content was above 5%. The OC contents of the mixtures with 10% and 20% biochar were generally lower than the predicted values. This implies possible interaction between soil components and biochar and/or the effect of biochar oxidation. For soils amended with biochars produced at 300°C, the N2 SA (N2-SA) values were underestimated. The predicted CO2 SA (CO2-SA) values of the mixtures at the biochar content of 10% and 20% were generally higher than the experimental values. Sorption of imidacloprid to the soils amended with biochar at 10% and 20% levels, excluding the soils amended with rice (SR300) and wheat (SW300) straw-derived biochar produced at 300°C, was lower than the predicted value. For SR300 and SW300, the intrinsic sorption capacity of biochar was enhanced by 1.3-5.6 times, depending on the biochar, solute concentration, and biochar dose. This study indicates that biochars would be helpful to stabilize the soil contaminated with imidacloprid, isoproturon, and atrazine, but the sorption capacity of the mixtures could exceed or fall short of predicted values without assuming a cross-effect between soil and biochar. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Runoff and drainage losses of atrazine, metribuzin, and metolachlor in three water management systems.

    Science.gov (United States)

    Gaynor, J D; Tan, C S; Drury, C F; Welacky, T W; Ng, H Y F; Reynolds, W D

    2002-01-01

    Rainfall can transport herbicides from agricultural land to surface waters, where they become an environmental concern. Tile drainage can benefit crop production by removing excess soil water but tile drainage may also aggravate herbicide and nutrient movement into surface waters. Water management of tile drains after planting may reduce tile drainage and thereby reduce herbicide losses to surface water. To test this hypothesis we calculated the loss of three herbicides from a field with three water management systems: free drainage (D), controlled drainage (CD), and controlled drainage with subsurface irrigation (CDS). The effect of water management systems on the dissipation of atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine), metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazine-5(4H)-one), and metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] in soil was also monitored. Less herbicide was lost by surface runoff from the D and CD treatments than from CDS. The CDS treatment increased surface runoff, which transported more herbicide than that from D or CD treatments. In one year, the time for metribuzin residue to dissipate to half its initial value was shorter for CDS (33 d) than for D (43 d) and CD (46 d). The half-life of atrazine and metolachlor were not affected by water management. Controlled drainage with subsurface irrigation may increase herbicide loss through increased surface runoff when excessive rain is received soon after herbicide application. However, increasing soil water content in CDS may decrease herbicide persistence, resulting in less residual herbicide available for aqueous transport.

  10. Temperature-dependent sensitivity of growth and photosynthesis of Scenedesmus obliquus, Navicula pelliculosa and two strains of Microcystis aeruginosa to the herbicide atrazine.

    Science.gov (United States)

    Chalifour, Annie; Juneau, Philippe

    2011-05-01

    The temperature-dependent sensitivities of two algal species and two strains of cyanobacteria to the photosynthesis-inhibiting herbicide atrazine were evaluated in order to understand how the interaction between acclimation temperature and herbicide will affect growth and photosynthesis of aquatic microorganisms. The green alga Scenedesmus obliquus, the diatom Navicula pelliculosa and a toxic and non-toxic strain of Microcystis aeruginosa were acclimated to three different temperatures (10, 15 and 25°C) and exposed to five concentrations of the herbicide atrazine (0-0.15μM) for 72h. Growth, photosynthetic yields, energy fluxes within photosystem II and pigment content were then measured as potential responses to each treatment. With the exception of N. pelliculosa, the toxicity of atrazine was higher when microorganisms were acclimated to lower temperatures. N. pelliculosa was not only the most tolerant to atrazine, but also had a similar sensitivity to this herbicide at every temperature. The observed differences in growth sensitivity to atrazine at low temperature are associated with the ability of algae and cyanobacteria to cope with high excitation pressure, by increasing its protective carotenoid content and non-photochemical energy dissipation. Our results demonstrate that future guidelines for the protection of aquatic life should consider water temperature as an important factor influencing the toxicity of atrazine to aquatic microorganisms. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  11. Installation and implementation of PC COSYMA; PC COSYMAn kaeyttoeoenotto ja soveltaminen

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, J. [VTT Energy, Espoo (Finland). Nuclear Energy

    1995-12-01

    COSYMA is a probabilistic reactor accident consequence assessment model developed in the 1980`s by the research institutes of the EC countries, primarily by NRPB and KfK. In 1993 a simplified version of the program was released to be implemented on a PC. In the study the PC COSYMA program was applied to calculate as the end points nuclide concentrations, doses received, numbers of health effects, areas affected by countermeasures and other results related to countermeasure strategies. Some results are compared with the results obtained by the ARANO program developed by VTT Energy (Technical Research Centre of Finland) to quarantee proper interpretation of the application. (15 refs.).

  12. PC-based car license plate reader

    Science.gov (United States)

    Hwang, Chung-Mu; Shu, Shyh-Yeong; Chen, Wen-Yu; Chen, Yie-Wern; Wen, Kuang-Pu

    1992-11-01

    A car license plate reader (CLPR) using fuzzy inference and neural network algorithm has been developed in Industrial Technology Research Institute (ITRI) and installed in highway toll stations to identify stolen cars. It takes an average of 0.7 seconds to recognize a car license plate by using a PC with 80486-50 CPU. The recognition rate of the system is about 97%. The techniques of CLPR include vehicle sensing, image grab control, optic pre- processing, lighting, and optic character recognition (OCR). The CLPR can be used in vehicle flow statistics, the checking of stolen vehicles, automatic charging systems in parking lots or garage management, and so on.

  13. Securing your PC and protecting your privacy.

    Science.gov (United States)

    Schloman, Barbara F

    2004-10-22

    Working in a networked information environment brings new opportunities for getting and sharing information. Regrettably, these benefits of the Internet are challenged by forces that would interfere to satisfy their own profit or malevolent motives. Your networked computer can be infected by viruses, worms, or Trojan horses or infiltrated by spyware, adware, or pop-ups. Without being aware of the dangers and taking precautionary steps, your PC is susceptible to being compromised and your privacy invaded. This column will highlight some of the dangers and offer basic steps for securing your computer and protecting your privacy.

  14. Evaluation of FPGA to PC feedback loop

    Science.gov (United States)

    Linczuk, Pawel; Zabolotny, Wojciech M.; Wojenski, Andrzej; Krawczyk, Rafal D.; Pozniak, Krzysztof T.; Chernyshova, Maryna; Czarski, Tomasz; Gaska, Michal; Kasprowicz, Grzegorz; Kowalska-Strzeciwilk, Ewa; Malinowski, Karol

    2017-08-01

    The paper presents the evaluation study of the performance of the data transmission subsystem which can be used in High Energy Physics (HEP) and other High-Performance Computing (HPC) systems. The test environment consisted of Xilinx Artix-7 FPGA and server-grade PC connected via the PCIe 4xGen2 bus. The DMA engine was based on the Xilinx DMA for PCI Express Subsystem1 controlled by the modified Xilinx XDMA kernel driver.2 The research is focused on the influence of the system configuration on achievable throughput and latency of data transfer.

  15. Redefining Projections of Disease and Nonbattle Injury Patient Condition Code Distributions with Casualty Data from Operation Iraqi Freedom

    Science.gov (United States)

    2006-07-30

    Freedom-II PC Code Diagnoses by PC Clusters Male Female Respiratory Cluster 232 Allergic rhinitis all cases 0.27% 0.20% 233 Upper...to PC clusters was derived (see Table 11). For example, individual diagnoses that fell within the ICD-9 category of Infectious Diseases (e.g., food ...5.38% Gastrointestinal Cluster 243 Food poisoning all organisms disabling symptoms 0.25% 0.58% 244 Food poisoning all organisms moderate

  16. Verification of the CONPAS (CONtainment Performance Analysis System) code package

    Energy Technology Data Exchange (ETDEWEB)

    Kim, See Darl; Ahn, Kwang Il; Song, Yong Man; Choi, Young; Park, Soo Yong; Kim, Dong Ha; Jin, Young Ho

    1997-09-01

    CONPAS is a computer code package to integrate the numerical, graphical, and results-oriented aspects of Level 2 probabilistic safety assessment (PSA) for nuclear power plants under a PC window environment automatically. For the integrated analysis of Level 2 PSA, the code utilizes four distinct, but closely related modules: (1) ET Editor, (2) Computer, (3) Text Editor, and (4) Mechanistic Code Plotter. Compared with other existing computer codes for Level 2 PSA, and CONPAS code provides several advanced features: computational aspects including systematic uncertainty analysis, importance analysis, sensitivity analysis and data interpretation, reporting aspects including tabling and graphic as well as user-friendly interface. The computational performance of CONPAS has been verified through a Level 2 PSA to a reference plant. The results of the CONPAS code was compared with an existing level 2 PSA code (NUCAP+) and the comparison proves that CONPAS is appropriate for Level 2 PSA. (author). 9 refs., 8 tabs., 14 figs.

  17. Fundamentals of convolutional coding

    CERN Document Server

    Johannesson, Rolf

    2015-01-01

    Fundamentals of Convolutional Coding, Second Edition, regarded as a bible of convolutional coding brings you a clear and comprehensive discussion of the basic principles of this field * Two new chapters on low-density parity-check (LDPC) convolutional codes and iterative coding * Viterbi, BCJR, BEAST, list, and sequential decoding of convolutional codes * Distance properties of convolutional codes * Includes a downloadable solutions manual

  18. Atrazine and nitrate in drinking water and the risk of preterm delivery and low birth weight in four Midwestern states

    DEFF Research Database (Denmark)

    Stayner, Leslie Thomas; Almberg, Kirsten; Jones, Rachael

    2017-01-01

    Background: Atrazine and nitrate are common contaminants in water, and there is limited evidence that they are associated with adverse birth outcomes. The objective of this study was to examine whether atrazine and nitrate in water are associated with an increased risk of preterm delivery (PTD...... monitoring program (AMP). Counties with a population of >300,000 were eliminated from the analyses in order to avoid confounding by urbanicity. Monthly child's sex, race and Hispanic ethnicity specific data were obtained from the states for estimating rates of PTD (preterm (VPTD, ....04,1.36). Exposure to nitrate was significantly associated with an increased rate of VPTD (RR1 ppm=1.08, 95%CI=1.02,1.15) and VLBW (RR1 ppm=1.17, 95%CI=1.08,1.25) when well use was restricted to 20% and the exposure was averaged over 9 months prior to birth. Conclusion: The positive and negative findings from our...

  19. Effects of an atrazine, metolachlor and fipronil mixture on Hyalella azteca (Saussure) in a modified backwater wetland.

    Science.gov (United States)

    Lizotte, Richard E; Knight, Scott S; Shields, F Douglas; Bryant, Charles T

    2009-12-01

    We examined the toxicity mitigation efficiency of a hydrologically modified backwater wetland amended with a pesticide mixture of atrazine, metolachlor, and fipronil, using 96 h survival bioassays with Hyalella azteca. Significant H. azteca 96 h mortality occurred within the first 2 h of amendment at the upstream amendment site but not at any time at the downstream site. H. azteca survival varied spatially and temporally in conjunction with measured pesticide mixture concentrations. Hyalella azteca 96 h survival pesticide mixture effects concentrations ranges were 10.214–11.997, 5.822–6.658, 0.650–0.817, and 0.030–0.048 μg L−1 for atrazine, metolachlor, fipronil, and fipronil-sulfone, respectively.

  20. Sublethal effects of atrazine and glyphosate on life history traits of Aedes aegypti and Aedes albopictus (Diptera: Culicidae).

    Science.gov (United States)

    Bara, Jeffrey J; Montgomery, Allison; Muturi, Ephantus J

    2014-08-01

    Although exposure of mosquito larvae to agricultural chemicals such as herbicides is common and widespread, our understanding of how these chemicals affect mosquito ecology and behavior is limited. This study investigated how an environmentally relevant concentration of two herbicides, atrazine and glyphosate, affects mosquito life history traits. One hundred and fifty (150) first instar Aedes (Stegomyia) aegypti (L.) or Aedes (Stegomyia) albopictus (Skuse) larvae were reared in 1.6 L of live oak leaf (Quercus virginiana) infusion in the presence (5 mg/L) or absence (0 mg/L) of atrazine or glyphosate. The containers were monitored daily to determine the emergence rates, sex ratio, male and female emergence times, and female body size. Emergence rates of A. aegypti from atrazine treatment were significantly higher relative to either glyphosate or control treatments (A. aegypti: atrazine = 93 ± 6% (±95% CI), glyphosate = 82 ± 5%, control = 78 ± 5%), while emergence rates of A. albopictus in atrazine treatments were significantly higher than in glyphosate treatments but not in controls (A. albopictus: atrazine = 84 ± 5 %, glyphosate = 76 ± 4%, control = 78 ± 4%). For both mosquito species, a sex ratio distortion with male bias was observed in control and glyphosate treatments, but not in atrazine treatments (A. aegypti: atrazine = 0.90 ± 0.17 (±SE), glyphosate = 1.63 ± 0.21, control = 1.69 ± 0.26; A. albopictus: atrazine = 1.09 ± 0.08, glyphosate = 1.88 ± 0.12, control = 1.37 ± 0.11). Emergence times for both sexes of the two mosquito species were significantly longer in atrazine treatments compared to glyphosate or control treatments (A. aegypti: females: atrazine = 11.20 ± 0.50 (days ± 95 % CI), glyphosate = 9.71 ± 0.23, control = 9.87 ± 0.21; males: atrazine = 9.46 ± 0.27, glyphosate = 8.80 ± 0.25, control

  1. Development of Advanced In core Management Codes for Ulchin Unit 1, 2

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hee; Park, Moon Gyu [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1996-12-31

    As the first case of FRAMATOME`s plants, Ulchin Unit 1 Cycle 8 core was loaded with V5H fuel. Because of the heterogeneity in the axial enrichment of the V5H fuel, FRAMATOME`s 2-D in core management codes, CEDRIC-CARIN-ESTHER, are no longer valid to be used for in core management. In order to analyze Ulchin Unit 1 an 2 cores loaded with V5H fuel exactly, this study substituted them with WH`s In core-3D and Tote code. The previous IN CORE-Tote codes have been utilized on the HP workstation or the IBM mainframe which are not easily accessible by the site engineers and require the complicated manipulation in the computer network system. This study developed the PC-version of IN CORE-3D and Tote codes available in plants, including an interface code linking the data measured by the in core instrument system (RIC-KIT system) to IN CORE code. These codes reduce the time to manage in core and increase the economic benefits. We installed the developed codes in Ulchin Unit 1 and 2 and actually applied them to the core power distribution measurement performed during Cycle 8 power escalation tests. The results satisfied all limits of Technical Specification very well. The major contents of this study can be categorized as follows. 1. Analysis of the in core management codes. (a) Analysis of flux mapping system and measurement reduction algorithm. (b) Analysis of the methodology of in core management codes. 2. Development and verification of PC-version in core management codes. (a) Development of the measured-data processing code (C2I). (b) Development of PC-version IN CORE code. (c) Development of PC-version Tote code (d) Verification of the developed codes. 3. Application to core physics test of Ulchin until cycle 8. (a) Power distribution measurement at 75% and 100%. (author). 14 refs., figs., tabs.

  2. In vitro evolution of an atrazine-degrading population under cyanuric acid selection pressure: evidence for the selective loss of a 47 kb region on the plasmid ADP1 containing the atzA, B and C genes.

    Science.gov (United States)

    Changey, F; Devers-Lamrani, M; Rouard, N; Martin-Laurent, F

    2011-12-15

    The adaptation of microorganisms to pesticide biodegradation relies on the recruitment of catabolic genes by horizontal gene transfer and homologous recombination mediated by insertion sequences (IS). This environment-friendly function is maintained in the degrading population but it has a cost which could diminish its fitness. The loss of genes in the course of evolution being a major mechanism of ecological specialization, we mimicked evolution in vitro by sub-culturing the atrazine-degrading Pseudomonas sp. ADP in a liquid medium containing cyanuric acid as the sole source of nitrogen. After 120 generations, a new population evolved, which replaced the original one. This new population grew faster on cyanuric acid but showed a similar cyanuric acid degrading ability. Plasmid profiles and Southern blot analyses revealed the deletion of a 47 kb region from pADP1 containing the atzABC genes coding for the enzymes that turn atrazine into cyanuric acid. Long PCR and sequencing analyses revealed that this deletion resulted from a homologous recombination between two direct repeats of a 110-bp, identical to ISPps1 of Pseudomonas huttiensis, flanking the deleted 47 kb region. The loss of a region containing three functional genes constitutively expressed thereby constituting a genetic burden under cyanuric acid selection pressure was responsible for the gain in fitness of the new population. It highlights the IS-mediated plasticity of the pesticide-degrading potential and shows that IS not only favours the expansion of the degrading genetic potential thanks to dispersion and duplication events but also contribute to its reduction thanks to deletion events. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Vertical variation of atrazine mineralization capacity in soils Variación vertical de la capacidad de mineralización de atrazina en suelos

    Directory of Open Access Journals (Sweden)

    S. Hang

    2007-12-01

    Full Text Available The variation of atrazine mineralization capacity was investigated in two soil profiles selected with (adapted soil and without (non-adapted soil atrazine application history in Córdoba, Argentina. Atrazine evolution was characterized by balance of 14C-U-ring atrazine radioactivity between mineralized, extractable and non-extractable fractions by means of incubations under laboratory conditions in two soil situations: with dry heat treatment (T105 and without heat treatment (Control. The strong decrease of atrazine mineralization after microbial inactivation during all the incubation period in adapted soil suggests that the atrazine degraders were distributed throughout the entire adapted soil profile and were responsible for atrazine mineralization in subsurface horizons. In the non-adapted soil profile, the cometabolic process of mineralizing atrazine was corroborated. The atrazine mineralization capacity of subsurface horizons, where herbicide accumulation increases, should be considered and stimulated as a mechanism for the natural bioremediation of soils with frequent atrazine application.Se estudió la variación de la capacidad de mineralización de atrazina en dos suelos de la provincia de Córdoba, Argentina. Se seleccionaron dos perfiles de suelos con (suelo adaptado y sin (suelo no adaptado historia de aplicación de atrazina. La evolución de atrazina fue caracterizada mediante el balance de la radioactividad del 14C del anillo triazínico identificando las fracciones mineralizada, extractable y no extractable, durante incubaciones en condiciones de laboratorio con suelo tratado con calor (T105 y sin él (Control. La disminución de la capacidad de degradación de atrazina después de la inactivación microbiana y la limitada recuperación de esa capacidad observada en el perfil de suelo adaptado sugirió que los microorganismos degradadores de atrazina estarían distribuidos en todo el perfil siendo los responsables de la

  4. Cellular prion protein (PrPC) in the development of Merlin-deficient tumours.

    Science.gov (United States)

    Provenzano, L; Ryan, Y; Hilton, D A; Lyons-Rimmer, J; Dave, F; Maze, E A; Adams, C L; Rigby-Jones, R; Ammoun, S; Hanemann, C O

    2017-11-02

    Loss of function mutations in the neurofibromatosis Type 2 (NF2) gene, coding for a tumour suppressor, Merlin, cause multiple tumours of the nervous system such as schwannomas, meningiomas and ependymomas. These tumours may occur sporadically or as part of the hereditary condition neurofibromatosis Type 2 (NF2). Current treatment is confined to (radio) surgery and no targeted drug therapies exist. NF2 mutations and/or Merlin inactivation are also seen in other cancers including some mesothelioma, breast cancer, colorectal carcinoma, melanoma and glioblastoma. To study the relationship between Merlin deficiency and tumourigenesis, we have developed an in vitro model comprising human primary schwannoma cells, the most common Merlin-deficient tumour and the hallmark for NF2. Using this model, we show increased expression of cellular prion protein (PrPC) in schwannoma cells and tissues. In addition, a strong overexpression of PrPC is observed in human Merlin-deficient mesothelioma cell line TRA and in human Merlin-deficient meningiomas. PrPC contributes to increased proliferation, cell-matrix adhesion and survival in schwannoma cells acting via 37/67 kDa non-integrin laminin receptor (LR/37/67 kDa) and downstream ERK1/2, PI3K/AKT and FAK signalling pathways. PrPC protein is also strongly released from schwannoma cells via exosomes and as a free peptide suggesting that it may act in an autocrine and/or paracrine manner. We suggest that PrPC and its interactor, LR/37/67 kDa, could be potential therapeutic targets for schwannomas and other Merlin-deficient tumours.

  5. User`s guide and documentation manual for ``PC-Gel`` simulator

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Ming-Ming; Gao, Hong W.

    1993-10-01

    PC-GEL is a three-dimensional, three-phase (oil, water, and gas) permeability modification simulator developed by incorporating an in-situ gelation model into a black oil simulator (BOAST) for personal computer application. The features included in the simulator are: transport of each chemical species of the polymer/crosslinker system in porous media, gelation reaction kinetics of the polymer with crosslinking agents, rheology of the polymer and gel, inaccessible pore volume to macromolecules, adsorption of chemical species on rock surfaces, retention of gel on the rock matrix, and permeability reduction caused by the adsorption of polymer and gel. The in-situ gelation model and simulator were validated against data reported in the literature. The simulator PC-GEL is useful for simulating and optimizing any combination of primary production, waterflooding, polymer flooding, and permeability modification treatments. A general background of permeability modification using crosslinked polymer gels is given in Section I and the governing equations, mechanisms, and numerical solutions of PC-GEL are given in Section II. Steps for preparing an input data file with reservoir and gel-chemical transport data, and recurrent data are described in Sections III and IV, respectively. Example data inputs are enclosed after explanations of each input line to help the user prepare data files. Major items of the output files are reviewed in Section V. Finally, three sample problems for running PC-GEL are described in Section VI, and input files and part of the output files of these problems are listed in the appendices. For the user`s reference a copy of the source code of PC-GEL computer program is attached in Appendix A.

  6. Data of evolutionary structure change: 1A54A-1PC3A [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1A54A-1PC3A 1A54 1PC3 A A --------EASLTGAGATFPAPVYAKWADTYQKET-GNK...A 378 PHE CA 440 GLN CA 487 PHE CA 535 1PC3... A 1PC3A LYS CA 277 ASN CA 192 1PC3 A 1PC3A LSKQDPEGWGK

  7. Kinetic and isotherm error optimization studies for adsorption of atrazine and imidacloprid on bark of Eucalyptus tereticornis L.

    Science.gov (United States)

    Mandal, Abhishek; Singh, Neera

    2016-01-01

    The aim of this study was to establish the bark of Eucalyptus tereticornis L. (EB) as a low cost bio-adsorbent for the removal of imidacloprid and atrazine from aqueous medium. The pseudo-first-order (PFO), pseudo-second-order (PSO), Elovich and intra-particle diffusion (IPD) models were used to describe the kinetic data and rate constants were evaluated. Adsorption data was analysed using ten 2-, 3- and 4-parameter models viz. Freundlich, Jovanovic, Langmuir, Temkin, Koble-Corrigan, Redlich-Peterson, Sips, Toth, Radke-Prausnitz, and Fritz-Schluender isotherms. Six error functions were used to compute the best fit single component isotherm parameters by nonlinear regression analysis. The results showed that the sorption of atrazine was better explained by PSO model, whereas the sorption of imidacloprid followed the PFO kinetic model. Isotherm model optimization analysis suggested that the Freundlich along with Koble-Corrigan, Toth and Fritz-Schluender were the best models to predict atrazine and imidacloprid adsorption onto EB. Error analysis suggested that minimization of chi-square (χ(2)) error function provided the best determination of optimum parameter sets for all the isotherms.

  8. Atrazine selects for ichthyotoxic Prymnesium parvum, a possible explanation for golden algae blooms in lakes of Texas, USA.

    Science.gov (United States)

    Yates, Brian S; Rogers, William J

    2011-11-01

    Prymnesium parvum Carter is a mixotrophic haptophyte which, under certain environmental conditions, produces potent toxins responsible for fish kills around the world since the 1930s. Many P. parvum blooms have occurred in catchments where crop agriculture is a dominant land use; however, the effects of herbicides on bloom dynamics have not yet been investigated. Aquatic microbial communities containing P. parvum were subjected to two separate experiments involving the addition of either atrazine or glyphosate at varying concentrations. After 14, 21, and 28 days at 10 μg/l atrazine we observed that the relative abundance of P. parvum was significantly higher compared to the control. After 28 days, the relative abundance of P. parvum was approximately 53% higher in 10 μg/l atrazine compared to the control. Glyphosate exhibited no statistically-significant effect on the relative abundance of P. parvum. Inadequate characterization of the microbial community and uncertainty due to ecological and allelopathic effects of P. parvum made it difficult to establish strong relationships between herbicide sensitivity and nutritional mode. Large volumes of mobile and persistent herbicides with high toxicity to phytoplankton are used in cotton defoliation in Texas prior to the typical P. parvum pre-bloom period. These results have important implications for management, such as whether reduction in herbicide runoff could decrease the frequency and duration of P. parvum blooms in the future.

  9. Adsorption and catalytic hydrolysis of carbaryl and atrazine on pig manure-derived biochars: impact of structural properties of biochars.

    Science.gov (United States)

    Zhang, Peng; Sun, Hongwen; Yu, Li; Sun, Tieheng

    2013-01-15

    Biochars were produced from pig manure to elucidate the influence of biochars with high ash contents on the fate of pesticides. Adsorption and catalytic hydrolysis of carbaryl and atrazine on original biochars and deashed biochars were investigated. The two pesticides were substantially adsorbed by the biochars, with organic carbon normalized sorption coefficient (K(oc)) values of 10(2.65)-10(3.66) L/kg for carbaryl and 10(1.90)-10(3.57) L/kg for atrazine at C(e) of 0.5 mg/L. Hydrophobic effect alone could not explain the sorption, and several other processes including pore-filling and π-π electron donor-acceptor interactions were involved in pesticide adsorption. Adsorption increased greatly on the deashed biochar, indicating that some organic sorption sites in the original biochars were blocked or difficult to access due to their interactions with inorganic moiety. The pesticides were found to hydrolyze faster in the presence of biochars, and in the presence of biochar pyrolyzed at 700 °C, carbaryl and atrazine were decomposed by 71.8% and 27.9% in 12 h, respectively. The elevated solution pH was the main reason for the enhanced hydrolysis; however both the mineral surface and dissolved metal ions released from the biochars were confirmed to catalyze the hydrolysis. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Comparative sensitivity of five species of macrophytes and six species of algae to atrazine, metribuzin, alachlor, and metolachlor

    Science.gov (United States)

    Fairchild, James F.; Ruessler, Shane; Carlson, A. Ron

    1998-01-01

    This study determined the relative sensitivity of five species of aquatic macrophytes and six species of algae to four commonly used herbicides (atrazine, metribuzin, alachlor, and metolachlor). Toxicity tests consisted of 96-h (duckweed and algae) or 14-d (submerged macrophytes) static exposures. The triazine herbicides (atrazine and metribuzin) were significantly more toxic to aquatic plants than were the acetanilide herbicides (alachlor and metolachlor). Toxicity studies ranked metribuzin > atrazine > alachlor > metolachlor in decreasing order of overall toxicity to aquatic plants. Relative sensitivities of macrophytes to these herbicides decreased in the order of Ceratophyllum > Najas > Elodea > Lemna > Myriophyllum. Relative sensitivities of algae to herbicides decreased in the order of Selenastrum > Chlorella > Chlamydomonas > Microcystis > Scenedesmus > Anabaena. Algae and macrophytes were of similar overall sensitivities to herbicides. Data indicated that Selenastrum, a commonly tested green alga, was generally more sensitive compared to other plant species. Lemna minor, a commonly tested floating vascular plant, was of intermediate sensitivity, and was fivefold less sensitive than Ceratophyllum, which was the most sensitive species tested. The results indicated that no species was consistently most sensitive, and that a suite of aquatic plant test species may be needed to perform accurate risk assessments of herbicides.

  11. Characterization of biochars derived from agriculture wastes and their adsorptive removal of atrazine from aqueous solution: A comparative study.

    Science.gov (United States)

    Liu, Na; Charrua, Alberto Bento; Weng, Chih-Huang; Yuan, Xiaoling; Ding, Feng

    2015-12-01

    The physicochemical properties of biochars produced from soybeans (SBB), corn stalks (CSB), rice stalks (RSB), poultry manure (PMB), cattle manure (CMB), and pig manure (PgMB) and their adsorption characteristics of atrazine were investigated. The adsorption capacity increased with the increase of temperature and initial atrazine concentration. More atrazine was removed from basic solutions than acidic solutions, due to the effects of adsorption and hydrolysis. The Freundlich isotherm adsorption parameters indicated that the adsorption capacity decreased in the order SBB>RSB>CMB>CSB>PMB>PgMB, which is associated to the pore volume of biochars. The total pore volume and biochar pH were concluded to play important roles in determining the adsorption capacity, and they may have contributed to physical adsorption mechanisms dominating the overall adsorption process (the low activation energy for all of the biochars). Modified Freundlich and intraparticle diffusion models were used to describe the kinetics of the adsorption process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Effects of environmental concentrations of atrazine on hemocyte density and phagocytic activity in the pond snail Lymnaea stagnalis (Gastropoda, Pulmonata)

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Jacqueline; Lagadic, Laurent

    2004-01-01

    Immunotoxicological effects of environmentally relevant concentrations (10, 23, 50, 100 {mu}g/l) of atrazine were studied in Lymnaea stagnalis. Individual hemolymph sampling was performed at 0, 24, 48, 72, 96, 168, 336, 504 and 672 h during exposure. Every atrazine concentration induced a significant increase in the mean number of circulating hemocytes, without any concentration-response relation. A peak (1.6-fold increase) of hemocyte density was observed after 96 h of exposure. After 504 h, the number of hemocytes remained higher only in the snails exposed to the two highest concentrations. Granulocytes contributed most to the increase in hemocyte density in herbicide-exposed snails. Both short- (24 and 96 h) and long-term (504 h) exposures resulted in significant inhibition of hemocyte phagocytic activity upon E. coli. Over the long-term, phagocytosis recovered for the two lowest concentrations. After 504 h of exposure, every herbicide level resulted in a significant reduction of reactive oxygen species production in E. coli-stimulated hemocytes, which was not observed for short-term exposures. - Phagocytosis and oxidative burst of hemocytes may be a functional biomarker for atrazine effects on snails.

  13. A New Environmentally Safe Formulation and of Low Cost for Prolonged Release System of Atrazine and Diuron

    Directory of Open Access Journals (Sweden)

    Gracy karla da Rocha Cortes

    2017-07-01

    Full Text Available Diuron and atrazine were incorporated in new formulations developed with the purpose to improve herbicides action through release systems, as well as to reduce the environmental toxicity. A low cost formulation (ALG/ESC was obtained by combining sodium alginate (ALG with fish scales of the Piau fish (ESC from the Leporinus elongatus species. From the crosslinking of ALG/ESC with CaCl2, the formulation ALG/ESC-CaCl2 was obtained. For ALG/ESC-CaCl2, the results are successful, showing a prolonged release of 3.5 and 4.5 days for atrazine and diuron, respectively. Based on parameters of an empirical equation used to fit the herbicide release data, it appears that the release systems of diuron and atrazine from ALG/ESC-CaCl2 are by diffusion processes due to anomalous transport, which did not follow Fick’s laws of diffusion. DOI: http://dx.doi.org/10.17807/orbital.v9i3.994

  14. BioCode: two biologically compatible Algorithms for embedding data in non-coding and coding regions of DNA.

    Science.gov (United States)

    Haughton, David; Balado, Félix

    2013-04-09

    In recent times, the application of deoxyribonucleic acid (DNA) has diversified with the emergence of fields such as DNA computing and DNA data embedding. DNA data embedding, also known as DNA watermarking or DNA steganography, aims to develop robust algorithms for encoding non-genetic information in DNA. Inherently DNA is a digital medium whereby the nucleotide bases act as digital symbols, a fact which underpins all bioinformatics techniques, and which also makes trivial information encoding using DNA straightforward. However, the situation is more complex in methods which aim at embedding information in the genomes of living organisms. DNA is susceptible to mutations, which act as a noisy channel from the point of view of information encoded using DNA. This means that the DNA data embedding field is closely related to digital communications. Moreover it is a particularly unique digital communications area, because important biological constraints must be observed by all methods. Many DNA data embedding algorithms have been presented to date, all of which operate in one of two regions: non-coding DNA (ncDNA) or protein-coding DNA (pcDNA). This paper proposes two novel DNA data embedding algorithms jointly called BioCode, which operate in ncDNA and pcDNA, respectively, and which comply fully with stricter biological restrictions. Existing methods comply with some elementary biological constraints, such as preserving protein translation in pcDNA. However there exist further biological restrictions which no DNA data embedding methods to date account for. Observing these constraints is key to increasing the biocompatibility and in turn, the robustness of information encoded in DNA. The algorithms encode information in near optimal ways from a coding point of view, as we demonstrate by means of theoretical and empirical (in silico) analyses. Also, they are shown to encode information in a robust way, such that mutations have isolated effects. Furthermore, the

  15. Rapid detoxification via glutathione S-transferase (GST) conjugation confers a high level of atrazine resistance in Palmer amaranth (Amaranthus palmeri).

    Science.gov (United States)

    Nakka, Sridevi; Godar, Amar S; Thompson, Curtis R; Peterson, Dallas E; Jugulam, Mithila

    2017-11-01

    Palmer amaranth (Amaranthus palmeri) is an economically troublesome, aggressive and damaging weed that has evolved resistance to six herbicide modes of action including photosystem II (PS II) inhibitors such as atrazine. The objective of this study was to investigate the mechanism and inheritance of atrazine resistance in Palmer amaranth. A population of Palmer amaranth from Kansas (KSR) had a high level (160 - 198-fold more; SE ±21 - 26) of resistance to atrazine compared to the two known susceptible populations MSS and KSS, from Mississippi and Kansas, respectively. Sequence analysis of the chloroplastic psbA gene did not reveal any known mutations conferring resistance to PS II inhibitors, including the most common Ser264Gly substitution for triazine resistance. However, the KSR plants rapidly conjugated atrazine at least 24 times faster than MSS via glutathione S-transferase (GST) activity. Furthermore, genetic analyses of progeny generated from reciprocal crosses of KSR and MSS demonstrate that atrazine resistance in Palmer amaranth is a nuclear trait. Although triazine resistance in Palmer amaranth was reported more than 20 years ago in the USA, this is the first report elucidating the underlying mechanism of resistance to atrazine. The non-target-site based metabolic resistance to atrazine mediated by GST activity may predispose the Palmer amaranth populations to have resistance to other herbicide families, and the nuclear inheritance of the trait in this dioecious species further exacerbates the propensity for its rapid spread. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  16. A weight-of-evidence approach for deriving a level of concern for atrazine that is protective of aquatic plant communities.

    Science.gov (United States)

    Moore, Dwayne Rj; Greer, Colleen D; Manning, Gillian; Wooding, Katie; Beckett, Kerrie J; Brain, Richard A; Marshall, Gary

    2017-07-01

    Atrazine is a selective triazine herbicide widely used in the United States primarily for control of broadleaf weeds in corn and sorghum. In 2003, the US Environmental Protection Agency (USEPA) concluded that atrazine poses potential risks to sensitive aquatic species. Consequently, a surface water monitoring program was developed to assess whether measured levels of atrazine could impact aquatic plants in vulnerable watersheds. To facilitate evaluation of the monitoring data, the Agency needed to establish a level of concern (LOC) below which atrazine would not cause unacceptable adverse effects to aquatic plant communities. Several attempts at developing a community-level LOC have followed from USEPA but none have been formally accepted or endorsed by independent Scientific Advisory Panels. As part of registration review, the USEPA needs to revisit development of a community-level LOC for atrazine that will be protective of aquatic plant communities. This article reviews 4 methods that can or have been used for this purpose. Collectively, the methods take advantage of the large number of single species and mesocosm studies that have been conducted for aquatic plants exposed to atrazine. The Plant Assemblage Toxicity Index (PATI) and the Comprehensive Aquatic Systems Model for atrazine (CASM ATZ2 ) incorporate single-species toxicity data but are calibrated with micro- and mesocosm study results to calculate community-level LOCs. The Brock et al. scoring system relies exclusively on mesocosm studies. Single-species toxicity data were used in a modified version of the USEPA's Water Quality Criteria (WQC) method. The 60-day LOCs calculated using the 4 methods ranged from 19.6 to 26 µg/L. A weight-of-evidence assessment indicated that the CASM ATZ2 method was the most environmentally relevant and statistically reliable method. Using all 4 methods with weights based on method reliability, the weighted 60-day LOC was 23.6 µg/L. Integr Environ Assess Manag 2017

  17. Pachyonychia congenita with late onset (PC tarda

    Directory of Open Access Journals (Sweden)

    A Sravanthi

    2016-01-01

    Full Text Available Pachyonychia congenita is a rare type of ectodermal dysplasia further classified into 4 types. Cutaneous manifestations seen in most of the cases of Pachyonychia congenita include palmoplantar keratoderma, follicular hyperkeratosis, wedge shaped nails, oral leukokeratosis and woolly hair. A 25-year-old male presented to us with thickened nails and scanty scalp hair. On examination, we noticed hyperkeratotic plaques over both the soles, palmoplantar hyperhidrosis and yellowish discoloration, wedging with subungual hyperkeratosis of all the nails. Follicular hyperkeratotic papules and steatocystoma multiplex were also observed over the scalp and face. The patient had history of natal teeth and on dental examination, lower central incisors were absent. All cutaneous changes in our case had manifested first in the 2nd decade except for natal teeth. All the above features suggested the diagnosis of pachyonychia congenita with late onset (PC tarda, which is an infrequently reported rare variant.

  18. Tantalum (oxy)nitrides nanotube arrays for the degradation of atrazine in vis-Fenton-like process

    Energy Technology Data Exchange (ETDEWEB)

    Du, Yingxun, E-mail: yxdu@niglas.ac.cn [Nanjing Institute of Geography and Limnology, State Key Laboratory of Lake Science and Environment, Chinese Academy of Sciences, Nanjing 210008 (China); Zhao, Lu [Nanjing Institute of Geography and Limnology, State Key Laboratory of Lake Science and Environment, Chinese Academy of Sciences, Nanjing 210008 (China); Chang, Yuguang [School of Biochemical and Environmental Engineering, Nanjing Xiaozhuang Univeristy, Nanjing 211171 (China); Su, Yaling [Nanjing Institute of Geography and Limnology, State Key Laboratory of Lake Science and Environment, Chinese Academy of Sciences, Nanjing 210008 (China)

    2012-07-30

    Highlights: Black-Right-Pointing-Pointer Tantala nanotubes on a Ta foil were formed by anodization in a NH{sub 4}F-containing electrolyte. Black-Right-Pointing-Pointer Tantalum (oxy)nitrides nanotubes were active for Fe{sup 3+} reduction under visible light. Black-Right-Pointing-Pointer Atrazine degradation by {center_dot}OH was accelerated with tantalum (oxy)nitrides nanotubes. Black-Right-Pointing-Pointer Tantalum (oxy)nitrides nanotubes display stable performance for atrazine degradation. - Abstract: In order to overcome the limitation of the application of nanoparticles, tantalum (oxy)nitrides nanotube arrays on a Ta foil were synthesized and introduced in vis (visible light)-Fenton-like system to enhance the degradation of atrazine. At first, the anodization of tantalum foil in a mild electrolyte solution containing ethylene glycol and water (v:v = 2:1) plus 0.5 wt.% NH{sub 4}F produced tantala nanotubes with an average diameter of 30 nm and a length of approximately 1 {mu}m. Then the nitridation of tantala nanotube arrays resulted in the replacement of N atoms to O atoms to form tantalum (oxy)nitrides (TaON and Ta{sub 3}N{sub 5}), as testified by XRD and XPS analyses. The synthesized tantalum (oxy)nitrides nanotubes absorb well in the visible region up to 600 nm. Under visible light, tantalum (oxy)nitrides nanotube arrays were catalytically active for Fe{sup 3+} reduction. With tantalum (oxy)nitrides nanotube arrays, the degradation of atrazine and the formation of the intermediates in vis/Fe{sup 3+}/H{sub 2}O{sub 2} system were significantly accelerated. This was explained by the higher concentration of Fe{sup 2+} and thus the faster decomposition of H{sub 2}O{sub 2} with tantalum (oxy)nitrides nanotubes. In addition, tantalum (oxy)nitrides nanotubes exhibited stable performance during atrazine degradation for three runs. The good performance and stability of the tantalum (oxy)nitrides nanotubes film with the convenient separation, suggest that this film is

  19. Removal of atrazine and its by-products from water using electrochemical advanced oxidation processes.

    Science.gov (United States)

    Komtchou, Simon; Dirany, Ahmad; Drogui, Patrick; Robert, Didier; Lafrance, Pierre

    2017-11-15

    Atrazine (ATZ) is one of the most common pesticides detected in surface water in Quebec (Canada). The present study was mainly focused on the degradation of ATZ and its by-products using electrochemical advanced oxidation processes such as photo-electro-Fenton (PEF), electro-Fenton (EF) and anodic-oxidation with simultaneous H2O2 formation (AO - H2O2). The comparison of these processes showed that PEF process was found to be the most effective process in removing ATZ and its by-products from both synthetic solution (ATZ0 = 100 μg L(-1)) and real agricultural surface water enriched with ATZ (ATZ0 = 10 μg L(-1)). Different operating parameters, including wavelength of the light, pH, current density and the presence of natural organic matter (humic acids) were investigated for PEF process using boron-doped diamond (BDD) anode and graphite cathode. The current density and the wavelength of the light were the most important parameters in the ATZ degradation efficiency. The best operating conditions were recorded for the synthetic samples at a current density of 18.2 mA cm(-2), a pH of 3.0 and treatment time of 45 min. Results showed that atrazine-desethyl-desisopropyl (DEDIA) was the most important by-product recorded. More than 99% of ATZ oxidation was recorded after 15 min of treatment and all the concentrations of major by-products were less than the limit of detection after 45 min of treatment. The PEF process was also tested for real surface water contaminated by ATZ: i) with and without addition of iron; ii) without pH adjustment (pH ∼ 6.7) and with pH adjustment (pH ∼ 3.1). In spite of the presence of radical scavenger and iron complexation the PEF process was more effective to remove ATZ from real surface water when the pH value was adjusted near to 3.0. The ATZ removal was 96.0% with 0.01 mM of iron (kapp = 0.13 min(-1)) and 100% with 0.1 mM of iron (kapp = 0.17 min(-1)). Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Affine Grassmann codes

    DEFF Research Database (Denmark)

    Høholdt, Tom; Beelen, Peter; Ghorpade, Sudhir Ramakant

    2010-01-01

    We consider a new class of linear codes, called affine Grassmann codes. These can be viewed as a variant of generalized Reed-Muller codes and are closely related to Grassmann codes.We determine the length, dimension, and the minimum distance of any affine Grassmann code. Moreover, we show...

  1. Changes in Sensitivity to the Effects of Atrazine on the Luteinizing Hormone Surge in Female Sprague-Dawley Rats after Repeated Daily Doses: Correlation with Liver Enzyme Expression.

    Science.gov (United States)

    Breckenridge, Charles B; Foradori, Chad D; Sawhney Coder, Pragati; Simpkins, James W; Sielken, Robert L; Handa, Robert J

    2017-11-14

    Atrazine suppression of the LH surge slowly develops over time and peaks after 4 days; sensitivity to atrazine decreases after 8 or 14 days of dosing. Adaptation of the LH response was correlated with increased phase I and phase II liver enzyme activity/expression. The effect of atrazine on the LH surge was evaluated in female Sprague-Dawley rats administered 100 mg/kg/day atrazine by gavage for 1, 2, 3, or 4 consecutive days or 6.5, 50, or 100 mg/kg/day atrazine for 4, 8, or 14 days. No statistically significant effects of atrazine were seen on peak plasma LH or LH area under the curve (AUC) after one, two, or three doses of 100 mg/kg/day. Four daily doses of 50 or 100 mg/kg atrazine significantly reduced peak LH and LH AUCs, whereas 6.5 mg/kg/day had no effect. After 8 or 14 days of treatment, statistically significantly reduced peak LH and LH AUC were observed in the 100 mg/kg/day dose group, but not in the 6.5 or 50 mg/kg/day dose groups, although significantly reduced LH was observed in one sample 9 hr after lights-on in the 50 mg/kg/day dose group on day 14. The number of days of treatment required to achieve a significant suppression of the LH surge is consistent with the repeat-dose pharmacokinetics of the chlorotriazines. The apparent adaptation to the effect of atrazine on the LH surge after 8 or 14 days may be related to the induction of phase I or, more likely, phase II metabolism observed in this study after 8 days, or to a decreased sensitivity of the hypothalamic-pituitary-adrenal axis or an homeostatic adaption of the effect of atrazine on the LH surge mechanism. Birth Defects Research, 2017. © 2017 The Authors. Birth Defects Research Published by Wiley Periodicals, Inc. © 2017 The Authors. Birth Defects Research Published by Wiley Periodicals, Inc.

  2. Mixing of MnPc electronic states at the MnPc/Au(110) interface

    Science.gov (United States)

    Gargiani, Pierluigi; Lisi, Simone; Avvisati, Giulia; Mondelli, Pierluigi; Fatale, Sara; Betti, Maria Grazia

    2017-10-01

    Manganese-phthalocyanines form assembled chains with a variety of ordered super-structures, flat lying along the Au(110) reconstructed channels. The chains first give rise to a ×5 symmetry reconstruction, while further deposition of MnPc leads to a ×7 periodicity at the completion of the first single layer. A net polarization with the formation of an interface dipole is mainly due to the molecular π-states located on the macrocycles pyrrole rings, while the central metal ion induces a reduction in the polarization, whose amount is related to the Mn-Au interaction. The adsorption-induced interface polarization is compared to other 3d-metal phthalocyanines, to unravel the role of the central metal atom configuration in the interaction process of the d-states. The MnPc adsorption on Au(110) induces the re-hybridization of the electronic states localized on the central metal atom, promoting a charge redistribution of the molecular orbitals of the MnPc molecules. The molecule-substrate interaction is controlled by a symmetry-determined mixing between the electronic states, involving also the molecular empty orbitals with d character hybridized with the nitrogen atoms of the pyrrole ring, as deduced by photoemission and X-ray absorption spectroscopy exploiting light polarization. The symmetry-determined mixing between the electronic states of the Mn metal center and of the Au substrate induces a density of states close to the Fermi level for the ×5 phase.

  3. Influence of the pesticides glyphosate, chlorpyrifos and atrazine on growth parameters of nonochratoxigenic Aspergillus section Nigri strains isolated from agricultural soils.

    Science.gov (United States)

    Carranza, Cecilia S; Barberis, Carla L; Chiacchiera, Stella M; Magnoli, Carina E

    2014-01-01

    This investigation was undertake to determine the effect of glyphosate, chlorpyrifos and atrazine on the lag phase and growth rate of nonochratoxigenic A. niger aggregate strains growing on soil extract medium at -0.70, -2.78 and -7.06 MPa. Under certain conditions, the glyphosate concentrations used significantly increased micelial growth as compared to control. An increase of about 30% was observed for strain AN 251 using 5 and 20 mg L(-1) of glyphosate at -2.78 MPa. The strains behaved differently in the presence of the insecticide chlorpyrifos. A significant decrease in growth rate, compared to control, was observed for all strains except AN 251 at -2.78 MPa with 5 mg L(-1). This strain showed a significant increase in growth rate. With regard to atrazine, significant differences were observed only under some conditions compared to control. An increase in growth rate was observed for strain AN 251 at -2.78 MPa with 5 and 10 mg L(-1) of atrazine. By comparison, a reduction of 25% in growth rate was observed at -7.06 MPa and higher atrazine concentrations. This study shows that glyphosate, chlorpyrifos and atrazine affect the growth parameters of nonochratoxigenic A. niger aggregate strains under in vitro conditions.

  4. Augmenting atrazine and hexachlorobenzene degradation under different soil redox conditions in a bioelectrochemistry system and an analysis of the relevant microorganisms.

    Science.gov (United States)

    Wang, Hui; Cao, Xian; Li, Lei; Fang, Zhou; Li, Xianning

    2018-01-01

    Soil microbial fuel cells (MFCs) are a sustainable technology that degrades organic pollutants while generating electricity. However, there have been no detailed studies of the mechanisms of pollutant degradation in soil MFCs. In this study, the effects of external resistance and electrode effectiveness on atrazine and hexachlorobenzene (HCB) degradation were evaluated, the performance of soil MFCs in the degradation of these pollutants under different soil redox conditions was assessed, and the associated microorganisms in the anode were investigated. With an external resistance of 20Ω, the degradation efficiencies of atrazine and HCB were 95% and 78%, respectively. The degradation efficiency, degradation rate increased with decreasing external resistance, while the half-life decreased. There were different degradation trends for different pollutants under different soil redox conditions. The fastest degradation rate of atrazine was in the upper MFC section (aerobic), whereas that of HCB was in the lower MFC section (anaerobic). The results showed that electrode effectiveness played a significant role in pollution degradation. In addition, the microbial community analysis demonstrated that Proteobacteria, especially Deltaproteobacteria involved in current generation was extremely abundant (27.49%) on soil MFC anodes, although the percentage abundances of atrazine degrading Rhodocyclaceae (8.77%), Desulfitobacterium (0.64%), and HCB degrading Desulfuromonas (0.73%), were considerably lower. The results of the study suggested that soil MFCs can enhance the degradation of atrazine and HCB, and bioelectrochemical reduction was the main mechanism for the pollutants degradation. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Persistence of the biocide activity of atrazine in soils of the southeast of Buenos Aires Province Persistência do herbicida atrazine em solos do sudeste da Provincia de Buenos Aires

    Directory of Open Access Journals (Sweden)

    A.A. Delmonte

    1996-01-01

    Full Text Available Atrazine persistence in soils of the southeast of Buenos Aires Province, was studied by an oat bioassay. Atrazine doses of 0.58, 1.16, and 2.32 mg.g-1 dry soil weight (DSW were applied to pots containing soils from Balcaree, A. Gonzáles Chaves and San Cayetano sites, whose organic matter (OM content of soils were 5.70, 5.15, and 3,84%, respectively. Avena sativa cv. Millauquén plants were grownth in the pots under greenhouse conditions at different times after atrazine application. Shoots were evenly cut above the soil and dry weight determined as a measure of plant growth. Plants grown in non-sprayed soil were used as controls. Relative dry weight (RDW of shoots was calculated as percentage of control. Atrazine phytotoxicity was expressed in terms of 50 % plant growth reduction (GR50 in the soils under study. Herbicide persistence was expressed in terms of days after treatment (DAT needed for the plant to achieve 80% of RDW. Atrazine GR50 values of 0.30, 0.64, and 0.90 mg.g-1 DSW in soils from San Cayetano, Balcare and A.G. Chaves, were respectively obtained at 42 DAT. Herbicide persistences at the recommended dose (1.16 mg.g-1 were 100, 143, and 221 DAT for A.G. Chaves, Balcarce and San Cayetano soils, respectively. San Cayetano soil had both the lowest OM content and cation exchange capacity (CEC, as well as the highest pH, of all the soil studied here. These results were consistent with both the lowest GR50 and the highest persistence abtained for atrazine in this soil.O objetivo do presente trabalho foi estudar a persistência da atrazine em solos do sudoeste da Província de Buenos Aires, Argentina, por meio de bioensaio com aveia. Estudaram-se doses de atrazine de 0; 0,58; 1,16 e 2,32 mg.g-1 de solo seco (SS, os quais foram aplicados em vasos que continham solos de Balcarce, A. Gonzáles Chaves e San Cayetano. O conteúdo de matéria orgânica (MO dos solos foram 5,70; 5,15 e 3,84% para Balcarce, A. Gonzáles Chaves e San Cayetano

  6. Turbo Codes Extended with Outer BCH Code

    DEFF Research Database (Denmark)

    Andersen, Jakob Dahl

    1996-01-01

    The "error floor" observed in several simulations with the turbo codes is verified by calculation of an upper bound to the bit error rate for the ensemble of all interleavers. Also an easy way to calculate the weight enumerator used in this bound is presented. An extended coding scheme is propose...... including an outer BCH code correcting a few bit errors.......The "error floor" observed in several simulations with the turbo codes is verified by calculation of an upper bound to the bit error rate for the ensemble of all interleavers. Also an easy way to calculate the weight enumerator used in this bound is presented. An extended coding scheme is proposed...

  7. Rateless feedback codes

    DEFF Research Database (Denmark)

    Sørensen, Jesper Hemming; Koike-Akino, Toshiaki; Orlik, Philip

    2012-01-01

    This paper proposes a concept called rateless feedback coding. We redesign the existing LT and Raptor codes, by introducing new degree distributions for the case when a few feedback opportunities are available. We show that incorporating feedback to LT codes can significantly decrease both...... the coding overhead and the encoding/decoding complexity. Moreover, we show that, at the price of a slight increase in the coding overhead, linear complexity is achieved with Raptor feedback coding....

  8. Generalized concatenated quantum codes

    Science.gov (United States)

    Grassl, Markus; Shor, Peter; Smith, Graeme; Smolin, John; Zeng, Bei

    2009-05-01

    We discuss the concept of generalized concatenated quantum codes. This generalized concatenation method provides a systematical way for constructing good quantum codes, both stabilizer codes and nonadditive codes. Using this method, we construct families of single-error-correcting nonadditive quantum codes, in both binary and nonbinary cases, which not only outperform any stabilizer codes for finite block length but also asymptotically meet the quantum Hamming bound for large block length.

  9. Implementation of a General Finite Element Code on an IBM PC Compatible Microcomputer.

    Science.gov (United States)

    1984-09-01

    l-r,0 ?CC.’j\\ WR1TE(#,’( APA )k’ PRICESSIN:G 9BLCY’ v, BLO-C 1,17 APPENDIX E MEF PROGRAM LISTINGS 4 The orogram listings for MEF are provided belowe...2,-30) (Vi :), ,!=-i, D- 2030 FORMATO )’ fl).iX,7E12.5) 40) CONTINUE C---- READ NODE CARDS 50 READ (MI, 1020) (’AV() 14=!,L16) 164 1020 tX FORM NEQ 00

  10. Price Indexes for PC Database Software and the Value of Code Compatibility

    OpenAIRE

    Harhoff, Dietmar; Moch, Dietmar

    1996-01-01

    Changing product quality poses a challenge for the computation of price indexes, in particular in technologically advanced industries. We assess the differences between traditional and quality-corrected indexes by computing hedonic and matched-model price indexes for personal computer database software. Our database covers the price development in Germany from 1986 to 1994. Quality-adjusted software prices decline by 7.4 percent according to our hedonic index. Surprisingly, a matchedmodel ind...

  11. Sublethal effects of atrazine on embryo-larval development of Rhinella arenarum (Anura: Bufonidae).

    Science.gov (United States)

    Svartz, Gabriela V; Herkovits, Jorge; Pérez-Coll, Cristina S

    2012-05-01

    Atrazine (ATR), one of the most widely used herbicides in the world, affects not only target organisms but also the biota in general. Here, the teratogenic and neurotoxic effects of ATR on Rhinella arenarum (South American toad) embryos, and larvae were evaluated by means of standardized bioassays during acute and chronic exposures. The herbicide had a significant incidence of malformations, with a Teratogenic Index (TI) of 3.28. The main effects were delayed development, reduced body size, microcephaly, axial flexures, wavy tail and edema. In addition, delayed development, reduced development of forelimbs, and edema were recorded at metamorphosis stages. Scanning electron microscopy allowed observing different degrees of cellular dissociation and persistent cilliar cells in specific regions like the adhesive structure and tail fin. Results obtained by ATR 24 h pulse exposures at six developmental stages pointed out blastula as the most susceptible developmental stage both for immediate and delayed adverse effects. A noteworthy recovery capacity from acute toxic effects was recorded from the neural plate stage onwards. Regarding neurotoxic effects, abnormal, and erratic swimming and spasmodic contractions were recorded. Both the teratogenic and neurotoxic effects reported in this study demonstrate the importance of evaluating sublethal effects in non-target organisms as they could imply reduced fitness of individuals and eventually a population decline. The Hazard Quotients (HQ) for ATR ranged from 0.14 to 10.80, and the fact that some of these values are above USEPA's level of concern indicate that ATR is likely a risk to R. arenarum.

  12. Effects of Atrazine on the Development of Neural System of Zebrafish, Danio rerio

    Directory of Open Access Journals (Sweden)

    Hao Wang

    2015-01-01

    Full Text Available By comparative analysis of histomorphology and AChE activity, the changes of physiological and biochemical parameters were determined in zebrafish embryos and larvae dealt with atrazine (ATR at different concentrations (0.0001, 0.001, 0.01, 0.1, and 1 mg/L. This study showed that the development of the sarcomere and the arrangement of white muscle myofibers were affected by ATR significantly and the length of sarcomere shortened. Further analysis of the results showed that the AChE activity in juvenile fish which was treated with ATR was downregulated, which can indicate that the innervation efficiency to the muscle was impaired. Conversely, the AChE activity in zebrafish embryos which was treated with ATR was upregulated. A parallel phenomenon showed that embryonic primary sensory neurons (Rohon-Beard cells, principally expressing AChE in embryos, survived the physiological apoptosis. These phenomena demonstrated that the motor integration ability of the zebrafish was damaged by ATR which can disturb the development of sensory neurons and sarcomere and the innervations of muscle.

  13. In-situ atrazine biodegradation dynamics in wheat (Triticum) crops under variable hydrologic regime

    Science.gov (United States)

    la Cecilia, Daniele; Maggi, Federico

    2017-08-01

    A comprehensive biodegradation reaction network of atrazine (ATZ) and its 18 byproducts was coupled to the nitrogen cycle and integrated in a computational solver to assess the in-situ biodegradation effectiveness and leaching along a 5 m deep soil cultivated with wheat in West Wyalong, New South Wales, Australia. Biodegradation removed 97.7% of 2 kg/ha ATZ yearly applications in the root zone, but removal substantially decreased at increasing depths; dechlorination removed 79% of ATZ in aerobic conditions and 18% in anaerobic conditions, whereas deethylation and oxidation removed only 0.11% and 0.15% of ATZ, respectively. The residual Cl mass fraction in ATZ and 4 byproducts was 2.4% of the applied mass. ATZ half-life ranged from 150 to 247 days in the soil surface. ATZ reached 5 m soil depth within 200 years and its concentration increased from 1 ×10-6 to 4 ×10-6 mg/kgdry-soil over time. The correlation between ATZ specific biomass degradation affinity Φ0 and half-life t1/2, although relatively uncertain for both hydrolyzing and oxidizing bacteria, suggested that microorganisms with high Φ0 led to low ATZ t1/2. Greater ATZ applications were balanced by small nonlinear increments of ATZ biodegraded fraction within the root zone and therefore less ATZ leached into the shallow aquifer.

  14. Behavioral response and kinetics of terrestrial atrazine exposure in American toads (bufo americanus)

    Science.gov (United States)

    Storrs, Mendez S.I.; Tillitt, D.E.; Rittenhouse, T.A.G.; Semlitsch, R.D.

    2009-01-01

    Amphibians in terrestrial environments obtain water through a highly vascularized pelvic patch of skin. Chemicals can also be exchanged across this patch. Atrazine (ATZ), a widespread herbicide, continues to be a concern among amphibian ecologists based on potential exposure and toxicity. Few studies have examined its impact on the terrestrial juvenile or adult stages of toads. In the current study, we asked the following questions: (1) Will juvenile American toads (Bufo americanus) avoid soils contaminated with ATZ? (2) Can they absorb ATZ across the pelvic patch? (3) If so, how is it distributed among the organs and eventually eliminated? We conducted a behavioral choice test between control soil and soil dosed with ecologically relevant concentrations of ATZ. In addition, we examined the uptake, distribution, and elimination of water dosed with 14C-labeled ATZ. Our data demonstrate that toads do not avoid ATZ-laden soils. ATZ crossed the pelvic patch rapidly and reached an apparent equilibrium within 5 h. The majority of the radiolabeled ATZ ended up in the intestines, whereas the greatest concentrations were observed in the gall bladder. Thus, exposure of adult life stages of amphibians through direct uptake of ATZ from soils and runoff water should be considered in risk evaluations. ?? 2009 Springer Science+Business Media, LLC.

  15. Determination of Atrazine, Acetochlor, Clomazone, Pendimethalin and Oxyfluorfen in Soil by a Solid Phase Microextraction Method

    Directory of Open Access Journals (Sweden)

    Rada Đurović

    2008-01-01

    Full Text Available A solid phase microextraction (SPME method for simultaneous determination of atrazine, acetochlor, clomazone, pendimethalin and oxyfluorfen in soil samples was developed. The method is based on a combination of conventional liquid-solid procedure and a following SPME determination of the selected pesticides. Initially, various microextraction conditions, such as the fibre type, desorption temperature and time, extraction time and NaCl content, were investigated and optimized. Then, extraction efficiencies of severalsolvents (water, hexane, acetonitrile, acetone and methanol and the optimum number of extraction steps within the sample preparation step were optimized. According to the results obtained in these two sets of experiments, two successive extractions with methanol as the extraction solvent were the optimal sample preparation procedure, while the following conditions were found to be most efficient for SPME measurements: 100 μm PDMS fibre, desorption for 7 min at 2700C, 30 min extraction time and 5% NaCl content (w/v. Detection and quantification were done by gas chromatography-mass spectrometry(GC/MS. Relative standard deviation (RSD values for multiple analysis of soil samples fortified at 30 μg/kg of each pesticide were below 19%. Limits of detection (LOD for all the compounds studied were less than 2 μg/kg.

  16. Advanced video coding systems

    CERN Document Server

    Gao, Wen

    2015-01-01

    This comprehensive and accessible text/reference presents an overview of the state of the art in video coding technology. Specifically, the book introduces the tools of the AVS2 standard, describing how AVS2 can help to achieve a significant improvement in coding efficiency for future video networks and applications by incorporating smarter coding tools such as scene video coding. Topics and features: introduces the basic concepts in video coding, and presents a short history of video coding technology and standards; reviews the coding framework, main coding tools, and syntax structure of AV

  17. Coding for dummies

    CERN Document Server

    Abraham, Nikhil

    2015-01-01

    Hands-on exercises help you learn to code like a pro No coding experience is required for Coding For Dummies,your one-stop guide to building a foundation of knowledge inwriting computer code for web, application, and softwaredevelopment. It doesn't matter if you've dabbled in coding or neverwritten a line of code, this book guides you through the basics.Using foundational web development languages like HTML, CSS, andJavaScript, it explains in plain English how coding works and whyit's needed. Online exercises developed by Codecademy, a leading online codetraining site, help hone coding skill

  18. Characteristics of CoPc/CdS hybrid diode device

    Indian Academy of Sciences (India)

    Ag contact metal deposited on CoPc by e-beam evaporation and glass/ITO/CdS/ CoPc/Ag structures were fabricated. Rectification ratio, ideality factor, barrier height and junction parameters of the devices were determined. It is shown that device has diode characteristics with the ideality factor (n) of 4.8, rectification ratio of ...

  19. The response effect of pheochromocytoma (PC12) cell lines to ...

    African Journals Online (AJOL)

    The toxicity of oxidized multi-walled carbon nanotubes (o-MWCNTs) are of utmost concern and in most in-vitro studies conducted so far are on dendritic cell (DC) lines with limited data on PC12 cell lines. Objectives: We focused on the effect of o-MWCNTs in PC12 cells in vitro: a common model cell for neurotoxicity.

  20. Transforming PC Power Supplies into Smart Car Battery Conditioners

    Science.gov (United States)

    Rodriguez-Ascariz, J. M.; Boquete-Vazquez, L.

    2011-01-01

    This paper describes a laboratory project consisting of a PC power supply modification into an intelligent car-battery conditioner with both wireless and wired networking capabilities. Adding a microcontroller to an average PC power supply transforms it into a flexible, intelligent device that can be configured and that is suitable to keep car…

  1. PrPC from stem cells to cancer

    Directory of Open Access Journals (Sweden)

    Séverine eMartin-Lannerée

    2014-09-01

    Full Text Available The cellular prion protein PrPC was initially discovered as the normal counterpart of the pathological scrapie prion protein PrPSc, the main component of the infectious agent of Transmissible Spongiform Encephalopathies. While clues as to the physiological function of this ubiquitous protein were greatly anticipated from the development of knock-out animals, PrP-null mice turned out to be viable and to develop without major phenotypic abnormalities. Notwithstanding, the discovery that hematopoietic stem cells from PrP-null mice have impaired long-term repopulating potential has set the stage for investigating into the role of PrPC in stem cell biology. A wealth of data have now exemplified that PrPC is expressed in distinct types of stem cells and regulates their self-renewal as well as their differentiation potential. A role for PrPC in the fate restriction of embryonic stem cells has further been proposed. Paralleling these observations, an overexpression of PrPC has been documented in various types of tumours. In line with the contribution of PrPC to stemness and to the proliferation of cancer cells, PrPC was recently found to be enriched in subpopulations of tumour-initiating cells. In the present review, we summarize the current knowledge of the role played by PrPC in stem cell biology and discuss how the subversion of its function may contribute to cancer progression.

  2. Development Of A Multi-Channel Personal Computer (Pc) Based ...

    African Journals Online (AJOL)

    Development Of A Multi-Channel Personal Computer (Pc) Based Data Logger. ... Journal of Science and Technology (Ghana) ... PC (Personal Computer) based instrumentation is getting more attention because of three technological enhancements; increasing reliability of PCs, steadily decreasing cost of hard drive space ...

  3. Cytogenetic damage and induction of pro-oxidant state in human lymphocytes exposed in vitro to gliphosate, vinclozolin, atrazine, and DPX-E9636.

    Science.gov (United States)

    Lioi, M B; Scarfi, M R; Santoro, A; Barbieri, R; Zeni, O; Salvemini, F; Di Berardino, D; Ursini, M V

    1998-01-01

    We analyzed chromosome aberrations (CAs), sister chromatid exchanges (SCEs), mitotic index (MI), and glucose 6-phosphate dehydrogenase (G6PD) enzyme activity in human peripheral lymphocytes from three healthy donors exposed in vitro to different concentrations of gliphosate, vinclozolin, atrazine, and DPX-E9636. The pesticides gliphosate, vinclozolin, and atrazine have been studied in a broad range of genetic tests with predominantly conflicting or negative results, whereas little is known about the genotoxicity of DPX-E9636. In our experimental conditions, each chemical compound tested produced a dose-related increase in the percent of aberrant cells and an increase of SCE/cell. Furthermore, at the highest concentrations of vinclozolin, atrazine, and DPX-E9636, we observed a significant reduction of the mitotic index. The increase of G6PD activity in exposed lymphocyte cultures strongly indicated an induction of a pro-oxidant state of the cells as an initial response to pesticide exposure.

  4. Discussion on LDPC Codes and Uplink Coding

    Science.gov (United States)

    Andrews, Ken; Divsalar, Dariush; Dolinar, Sam; Moision, Bruce; Hamkins, Jon; Pollara, Fabrizio

    2007-01-01

    This slide presentation reviews the progress that the workgroup on Low-Density Parity-Check (LDPC) for space link coding. The workgroup is tasked with developing and recommending new error correcting codes for near-Earth, Lunar, and deep space applications. Included in the presentation is a summary of the technical progress of the workgroup. Charts that show the LDPC decoder sensitivity to symbol scaling errors are reviewed, as well as a chart showing the performance of several frame synchronizer algorithms compared to that of some good codes and LDPC decoder tests at ESTL. Also reviewed is a study on Coding, Modulation, and Link Protocol (CMLP), and the recommended codes. A design for the Pseudo-Randomizer with LDPC Decoder and CRC is also reviewed. A chart that summarizes the three proposed coding systems is also presented.

  5. Photovoltaic properties of SnCl{sub 2}Pc films and SnCl{sub 2}Pc/pentacene heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Lutsyk, P.; Vertsimakha, Ya. [Institute of Physics, National Academy of Sciences of Ukraine, Prosp. Nauky 46, 03028 Kyiv (Ukraine); Misiewicz, J.; Podhorodecki, A. [Institute of Physics, Wroclaw University of Technology, Wyb. S. Wyspianskiego 27, 50-370 Wroclaw (Poland)

    2007-01-05

    The optical and photovoltaic properties of dichlorotin phthalocyanine (SnCl{sub 2}Pc) films and SnCl{sub 2}Pc/pentacene (Pn) heterostructures (HS) have been studied. Weak bands at 1.35, 1.52 and 2.05eV have been found in absorption and modulated photoreflectance spectra of SnCl{sub 2}Pc films. These bands can be caused by the formation of charge transfer states. The low concentration of recombination centers of charge carriers has been formed on a free surface of SnCl{sub 2}Pc films. This concentration essentially decreases at air evacuation before vacuum deposition of a Pn layer. Therefore, interface with an insignificant recombination rate of charge carriers is formed for SnCl{sub 2}Pc/Pn HS. (author)

  6. PC-SEAPAK - ANALYSIS OF COASTAL ZONE COLOR SCANNER AND ADVANCED VERY HIGH RESOLUTION RADIOMETER DATA

    Science.gov (United States)

    Mcclain, C. R.

    1994-01-01

    incompatibilities between the MVP-AT image board and ZENITH computers. Also, the MVP-AT image board is not necessarily compatible with 486-based systems; users of 486-based systems should consult with Matrox about compatibility concerns. Other PC-SEAPAK requirements include a Microsoft mouse (serial version), 2Mb RAM, and 100Mb hard disk space. For data ingest and backup, 9-track tape, 8mm tape and optical disks are supported and recommended. PC-SEAPAK has been under development since 1988. Version 4.0 was updated in 1992, and is distributed without source code. It is available only as a set of 36 1.2Mb 5.25 inch IBM MS-DOS format diskettes. PC-SEAPAK is a copyrighted product with all copyright vested in the National Aeronautics and Space Administration. Phar Lap's DOS_Extender run-time version is integrated into several of the programs; therefore, the PC-SEAPAK programs may not be duplicated. Three of the distribution diskettes contain DOS_Extender files. One of the distribution diskettes contains Media Cybernetics' HALO88 font files, also licensed by NASA for dissemination but not duplication. IBM is a registered trademark of International Business Machines. MS-DOS is a registered trademark of Microsoft Corporation. HALO88 is a registered trademark of Media Cybernetics, but the product was discontinued in 1991.

  7. Locally orderless registration code

    DEFF Research Database (Denmark)

    2012-01-01

    This is code for the TPAMI paper "Locally Orderless Registration". The code requires intel threadding building blocks installed and is provided for 64 bit on mac, linux and windows.......This is code for the TPAMI paper "Locally Orderless Registration". The code requires intel threadding building blocks installed and is provided for 64 bit on mac, linux and windows....

  8. Algebraic geometric codes

    Science.gov (United States)

    Shahshahani, M.

    1991-01-01

    The performance characteristics are discussed of certain algebraic geometric codes. Algebraic geometric codes have good minimum distance properties. On many channels they outperform other comparable block codes; therefore, one would expect them eventually to replace some of the block codes used in communications systems. It is suggested that it is unlikely that they will become useful substitutes for the Reed-Solomon codes used by the Deep Space Network in the near future. However, they may be applicable to systems where the signal to noise ratio is sufficiently high so that block codes would be more suitable than convolutional or concatenated codes.

  9. Tantalum (oxy)nitrides nanotube arrays for the degradation of atrazine in vis-Fenton-like process.

    Science.gov (United States)

    Du, Yingxun; Zhao, Lu; Chang, Yuguang; Su, Yaling

    2012-07-30

    In order to overcome the limitation of the application of nanoparticles, tantalum (oxy)nitrides nanotube arrays on a Ta foil were synthesized and introduced in vis (visible light)-Fenton-like system to enhance the degradation of atrazine. At first, the anodization of tantalum foil in a mild electrolyte solution containing ethylene glycol and water (v:v=2:1) plus 0.5wt.% NH(4)F produced tantala nanotubes with an average diameter of 30nm and a length of approximately 1μm. Then the nitridation of tantala nanotube arrays resulted in the replacement of N atoms to O atoms to form tantalum (oxy)nitrides (TaON and Ta(3)N(5)), as testified by XRD and XPS analyses. The synthesized tantalum (oxy)nitrides nanotubes absorb well in the visible region up to 600nm. Under visible light, tantalum (oxy)nitrides nanotube arrays were catalytically active for Fe(3+) reduction. With tantalum (oxy)nitrides nanotube arrays, the degradation of atrazine and the formation of the intermediates in vis/Fe(3+)/H(2)O(2) system were significantly accelerated. This was explained by the higher concentration of Fe(2+) and thus the faster decomposition of H(2)O(2) with tantalum (oxy)nitrides nanotubes. In addition, tantalum (oxy)nitrides nanotubes exhibited stable performance during atrazine degradation for three runs. The good performance and stability of the tantalum (oxy)nitrides nanotubes film with the convenient separation, suggest that this film is a promising catalyst for vis-Fenton-like degradation. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Adsorption and catalytic hydrolysis of carbaryl and atrazine on pig manure-derived biochars: Impact of structural properties of biochars

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Peng, E-mail: phevos1983@yahoo.com.cn [MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Sun, Hongwen, E-mail: sunhongwen@nankai.edu.cn [MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Yu, Li [MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Sun, Tieheng [Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016 (China)

    2013-01-15

    Highlights: ► High ash content biochar can increase solution pH and released metal ions. ► Ash in biochar can combine pesticide through specific interactions. ► Composition and structure of biochar is favor for the hydrolysis of pesticides. -- Abstract: Biochars were produced from pig manure to elucidate the influence of biochars with high ash contents on the fate of pesticides. Adsorption and catalytic hydrolysis of carbaryl and atrazine on original biochars and deashed biochars were investigated. The two pesticides were substantially adsorbed by the biochars, with organic carbon normalized sorption coefficient (K{sub oc}) values of 10{sup 2.65}–10{sup 3.66} L/kg for carbaryl and 10{sup 1.90}–10{sup 3.57} L/kg for atrazine at C{sub e} of 0.5 mg/L. Hydrophobic effect alone could not explain the sorption, and several other processes including pore-filling and π–π electron donor–acceptor interactions were involved in pesticide adsorption. Adsorption increased greatly on the deashed biochar, indicating that some organic sorption sites in the original biochars were blocked or difficult to access due to their interactions with inorganic moiety. The pesticides were found to hydrolyze faster in the presence of biochars, and in the presence of biochar pyrolyzed at 700 °C, carbaryl and atrazine were decomposed by 71.8% and 27.9% in 12 h, respectively. The elevated solution pH was the main reason for the enhanced hydrolysis; however both the mineral surface and dissolved metal ions released from the biochars were confirmed to catalyze the hydrolysis.

  11. Monomial-like codes

    CERN Document Server

    Martinez-Moro, Edgar; Ozbudak, Ferruh; Szabo, Steve

    2010-01-01

    As a generalization of cyclic codes of length p^s over F_{p^a}, we study n-dimensional cyclic codes of length p^{s_1} X ... X p^{s_n} over F_{p^a} generated by a single "monomial". Namely, we study multi-variable cyclic codes of the form in F_{p^a}[x_1...x_n] / . We call such codes monomial-like codes. We show that these codes arise from the product of certain single variable codes and we determine their minimum Hamming distance. We determine the dual of monomial-like codes yielding a parity check matrix. We also present an alternative way of constructing a parity check matrix using the Hasse derivative. We study the weight hierarchy of certain monomial like codes. We simplify an expression that gives us the weight hierarchy of these codes.

  12. Run-09 pC polarimeter analysis

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, I.; Aschenauer, E.; Atoyan, G.; Bazilevsky, A.; Gill, R.; Huang, H.; Lee, S.; Li, X.; Makdisi, Y.; Morozov, B.; Nakagawa, I.; Svirida, D.; Zelenski, A.

    2010-08-01

    Analysis of PC polarimeter data at {radical}s = 200 and 500 GeV from Run9 is presented. Final polarization results, fill-by-fill, for blue and yellow beams, as to be used by RHIC experiments (in collisions) are released and collected in http://www4.rcf.bnl.gov/cnipol/pubdocs/Run09Offline/. Global relative systematic uncertainties {delta}P/P (to be considered as correlated from fill to fill) are 4.7% for 100 GeV beams, and 8.3% (12.1%) for blue (yellow) 250 GeV beams. For a product of two beam polarizations P{sub B} {center_dot} P{sub Y} (used in double spin asymmetry measurements) the relative uncertainty {delta}(P{sub B} {center_dot} P{sub Y})/(P{sub B} {center_dot} P{sub Y}) 8.8% for 100 GeV beams and 18.5% for 250 GeV beams. For the average between two beam polarization (P{sub B} + P{sub Y})/2 (used in single spin asymmetry measurements, when data from two polarized beams are combined) the relative uncertainty is 4.4% for 100 GeV beams and 9.2% for 250 GeV beams. Larger uncertainties for 250 GeV beams relate to significant rate related systematic effects experienced in the first part of Run9 (due to thicker targets used and smaller trans. beam size at higher beam energy).

  13. QR Codes 101

    Science.gov (United States)

    Crompton, Helen; LaFrance, Jason; van 't Hooft, Mark

    2012-01-01

    A QR (quick-response) code is a two-dimensional scannable code, similar in function to a traditional bar code that one might find on a product at the supermarket. The main difference between the two is that, while a traditional bar code can hold a maximum of only 20 digits, a QR code can hold up to 7,089 characters, so it can contain much more…

  14. Disentangling the near-infrared continuum spectral components of the inner 500 pc of Mrk 573: two-dimensional maps

    Science.gov (United States)

    Diniz, M. R.; Riffel, R. A.; Riffel, R.; Crenshaw, D. M.; Storchi-Bergmann, T.; Fischer, T. C.; Schmitt, H. R.; Kraemer, S. B.

    2017-08-01

    We present a near-infrared (near-IR) study of the spectral components of the continuum in the inner 500 × 500 pc2 of the nearby Seyfert galaxy Mrk 573 using adaptive optics near-IR integral field spectroscopy with the instrument near-infrared integral field spectrograph of the Gemini North Telescope at a spatial resolution of ˜50 pc. We performed spectral synthesis using the starlight code and constructed maps for the contributions of different age components of the stellar population: young (age ≤100 Myr), young-intermediate (100 age ≤ 700 Myr), intermediate-old (700 Myr age ≤ 2 Gyr) and old (age > 2 Gyr) to the near-IR K-band continuum, as well as their contribution to the total stellar mass. We found that the old stellar population is dominant within the inner 250 pc, while the intermediate-age components dominate the continuum at larger distances. A young stellar component contributes up to ˜20 per cent within the inner ˜70 pc, while hot dust emission and featureless continuum components are also necessary to fit the nuclear spectrum, contributing up to 20 per cent of the K-band flux there. The radial distribution of the different age components in the inner kiloparsec of Mrk 573 is similar to those obtained by our group for the Seyfert galaxies Mrk 1066, Mrk 1157 and NGC 1068 in previous works using a similar methodology. Young stellar populations (≤100 Myr) are seen in the inner 200-300 pc for all galaxies contributing with ≥20 per cent of the K-band flux, while the near-IR continuum is dominated by the contribution of intermediate-age stars (t = 100 Myr-2 Gyr) at larger distances. Older stellar populations dominate in the inner 250 pc.

  15. Hollow-Fibre-Supported Dispersive Liquid-Liquid Microextraction for Determination of Atrazine and Triclosan in Aqueous Samples

    OpenAIRE

    Letseka, Thabiso; George, Mosotho J.

    2017-01-01

    We report the application of the dispersive liquid-liquid microextraction coupled to hollow-fibre membrane-assisted liquid-phase microextraction and its application for extraction of atrazine and triclosan. Under optimum conditions, namely, 25 μL of a 1 : 4 chlorobenzene : ethyl acetate mixture dispersed in 1 mL of aqueous sample, 10% (m/v) NaCl, a magnetic stirrer speed at 600 rpm, and 10 minutes' extraction time with toluene-filled fibre as the acceptor phase, the method demonstrates suffic...

  16. Health risks resulting from contaminants transfers in soil-plants systems: case study of Atrazine in Lactuca sativa.

    Science.gov (United States)

    Mathieu, Camoin

    2015-04-01

    Food safety is presently at the center of great part of scientific and political debates. This represents a field of study in its own right of health risks, including ingestion by humans of hazardous biological, physical, chemical or radiological substances, from contaminated foods during different stages of production. Plant cultivation step is often one of the main sources of contamination, whether of voluntary (pesticide application) or accidental (nuclear, industrial waste, etc.) origin. As a result, the plants growth in an contaminated environment may increase the risk of transfer within the plant, and finally the exposure of humans. Furthermore, pesticides are among the main contaminants investigated in the frame of human health risks resulting from food intakes. However, most of these scientific works focus mainly on their occurrence and persistence in water bodies, and few of them are interested in soil/plants transfer. In this context, the understanding of the processes governing transfers of pesticides in plants is become a necessity, in particular to prevent human risks linked the ingestion of food produced in contaminated environments. This objective can be reached by studying the pollutants behavior in soils/plants transfers, and using various substances/plants couples. In our study, we selected a salad/pesticide couple as our experimental model. Atrazine was chosen as model contaminant because of its problematic presence in a large amount of environmental compartments, its physico-chemical properties and because of its long-term toxicity. Lactuca sativa has been selected as model plant because of its importance in French agriculture, and specifically in Languedoc-Roussillon. Salad has been cultivated in peats and irrigated with an atrazine spiked water solution (concentrations from 10 to 100 μg/L). Plant growth in such conditions has been compared to a growth in clean condition (irrigation with non spiked water). Measurements of atrazine contents in

  17. Atrazine in sub-acute exposure results in sperm DNA disintegrity and nuclear immaturity in rats

    Directory of Open Access Journals (Sweden)

    Rajab-Ali Sadrkhanloo

    2012-03-01

    Full Text Available This study was designed to evaluate the detrimental effect of atrazine (ATR on germinal epitheliums (GE cytoplasmic carbohydrate (CH and unsaturated fatty acids (UFA ratio and to clarify the effect of ATR on serum levels of FSH, LH, testosterone and inhibin-B (INH-B. The impact of ATR exposure on total antioxidant capacity (TAC, sperm DNA packing and integrity were also investigated. Seventy two Wistar rats were used. The rats in control group received vehicle and the animals in test groups received 100, 200 and 300 mg kg-1 BW of ATR orally on daily bases for 12, 24 and 48 days. In ATR-received groups the spermatogenesis cell were presented with dense reactive sites for lipidophilic staining associated with faint cytoplasmic CH accumulation. Dissociated germinal epithelium, negative tubular and repopulation indexes were manifested. The serum levels of testosterone, FSH, LH and INH-B decreased by 85% after 48 days exposure to high dose of ATR. TAC was reduced in a time- and dose-dependent manner. The sperm DNA damage was marked in animals which exposed to high dose of ATR (72.50 ± 2.25% and the percentage of nuclear immature sperm increased up to 83.40 ± 0.89%. In conclusion, ATR not only induced its detrimental effect on the endocrine function of the testes and pituitary gland but also affected the cytoplasmic CH ratio and consequently leads to inadequate energy supplement in spermatogenesis cells. Therefore the imbalanced oxidative stress occurs in testicular tissue, which in turn enhances the sperm DNA disintegrity and nuclear immaturity.

  18. Chronic exposure to the herbicide, atrazine, causes mitochondrial dysfunction and insulin resistance.

    Directory of Open Access Journals (Sweden)

    Soo Lim

    Full Text Available There is an apparent overlap between areas in the USA where the herbicide, atrazine (ATZ, is heavily used and obesity-prevalence maps of people with a BMI over 30. Given that herbicides act on photosystem II of the thylakoid membrane of chloroplasts, which have a functional structure similar to mitochondria, we investigated whether chronic exposure to low concentrations of ATZ might cause obesity or insulin resistance by damaging mitochondrial function. Sprague-Dawley rats (n = 48 were treated for 5 months with low concentrations (30 or 300 microg kg(-1 day(-1 of ATZ provided in drinking water. One group of animals was fed a regular diet for the entire period, and another group of animals was fed a high-fat diet (40% fat for 2 months after 3 months of regular diet. Various parameters of insulin resistance were measured. Morphology and functional activities of mitochondria were evaluated in tissues of ATZ-exposed animals and in isolated mitochondria. Chronic administration of ATZ decreased basal metabolic rate, and increased body weight, intra-abdominal fat and insulin resistance without changing food intake or physical activity level. A high-fat diet further exacerbated insulin resistance and obesity. Mitochondria in skeletal muscle and liver of ATZ-treated rats were swollen with disrupted cristae. ATZ blocked the activities of oxidative phosphorylation complexes I and III, resulting in decreased oxygen consumption. It also suppressed the insulin-mediated phosphorylation of Akt. These results suggest that long-term exposure to the herbicide ATZ might contribute to the development of insulin resistance and obesity, particularly where a high-fat diet is prevalent.

  19. Detoxification of Atrazine by Low Molecular Weight Thiols in Alfalfa (Medicago sativa).

    Science.gov (United States)

    Zhang, Jing Jing; Xu, Jiang Yan; Lu, Feng Fan; Jin, She Feng; Yang, Hong

    2017-10-16

    Low molecular weight (LMW) thiols in higher plants are a group of sulfur-rich nonprotein compounds and play primary and multiple roles in cellular redox homeostasis, enzyme activities, and xenobiotics detoxification. This study focused on identifying thiols-related protein genes from the legume alfalfa exposed to the herbicide atrazine (ATZ) residues in environment. Using high-throughput RNA-sequencing, a set of ATZ-responsive thiols-related protein genes highly up-regulated and differentially expressed in alfalfa was identified. Most of the differentially expressed genes (DEGs) were involved in regulation of biotic and abiotic stress responses. By analyzing the genes involved in thiols-mediated redox homeostasis, we found that many of them were thiols-synthetic enzymes such as γ-glutamylcysteine synthase (γECS), homoglutathione synthetase (hGSHS), and glutathione synthetase (GSHS). Using liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS), we further characterized a group of ATZ-thiols conjugates, which are the detoxified forms of ATZ in plants. Cysteine S-conjugate ATZ-HCl+Cys was the most important metabolite detected by MS. Several other ATZ-conjugates were also examined as ATZ-detoxified metabolites. Such results were validated by characterizing their analogs in rice. Our data showed that some conjugates under ATZ stress were detected in both plants, indicating that some detoxified mechanisms and pathways can be shared by the two plant species. Overall, these results indicate that LMW thiols play critical roles in detoxification of ATZ in the plants.

  20. A PC based seismic data transcription system

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Sang Yong; Chung, Bu Heung; Jang, Seong Hyung [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1997-12-01

    Old seismic data recorded on magnetic tapes is often difficult to read because of the tape sticking problem known as the `sticky syndrome`. It has to be transcribed to other suitable media using dedicated multiple systems during the whole project years. The first system requirement is the capability of reading gapless magnetic tape, which is peculiar to the old seismic data tapes. The second requirement would be the availability of storage devices with compact and huge capacity. The system must be cheap enough compared to the total cost of the data being transcribed. We introduce a PC based seismic data transcribing system. The system is equipped with an tape drive which can handle 800, 1600, 3200, and 6250 BPI densities. Well known storage devices such as 8mm Exabyte, 4mm DDS-2, and the SCSI CD recorder, are selected for the output devices. These output media should provide more durability, compactness, and portability than the original. Linux is chosen for the operating system. Unfortunately, the Linux, like other Unix systems, is subject to the limit in maximum i/o block size. The maximum block size of the SCSI tape driver is fixed to 32 KB, which is far less than the requirements in SEG-A, B, and C seismic tapes. A kernel patch is written to extend such a limit up to 2048 KB. Input and output programs are written to handle the tape data in variable block mode. A unique disk file format is designed to preserve the IBG(inter-block gap) within the disk copy. A utility program is also provided to manipulate the disk copy and to convert to SU(Seismic Unix) compatible SEG-Y file. Of the total two months of the transcription period, we spend most of the time in reading the sticky magnetic tapes. The seismic tapes had to be `baked` to dry out the moisture before reading. It took nine days to burn the all 85 diskettes. Writing two sets of 8mm Exabytes took only one day. It is considered that 8mm Exabyte can be the optimum output media for the main seismic data storage

  1. Eficácia de controle de plantas daninhas e toxicidade ao milho da mistura de foramsulfuron e Iodosulfuron isoladamente ou em associação com atrazine e/ou clorpirifós Weed control efficacy and corn toxicity of the foramsulfuron and iodosulfuron mixture, alone or combined with atrazine and/or chlorpyriphos

    Directory of Open Access Journals (Sweden)

    M.M. Trezzi

    2005-12-01

    Full Text Available Este trabalho constou de dois ensaios que avaliaram a toxicidade ao milho e a eficácia de controle de plantas daninhas dos herbicidas atrazine, da mistura foramsulfuron + iodosulfuron e do inseticida clorpirifós, isoladamente ou em mistura, aplicados em pósemergência. Utilizou-se o delineamento de blocos ao acaso com quatro repetições. No primeiro ensaio, todos os tratamentos foram capinados e constaram de: atrazine (3.000 g ha¹ de i.a.; atrazine + clorpirifós (3.000 + 225 g ha-1 de i.a.; atrazine + foramsulfuron + iodosulfuron + clorpirifós (2.250 + 15 + 1 + 225; 1.500 + 22,5 + 1,5 + 225; e 750 + 30 + 2 + 225 g ha-1 de i.a.; foramsulfuron + iodosulfuron (45 + 3 g ha-1 de i.a.; foramsulfuron + iodosulfuron + clorpirifós (45 + 3 + 225 g ha-1 de i.a.; e testemunha sem aplicação de herbicidas. Já no segundo ensaio foram utilizados todos os tratamentos anteriores, com exceção da mistura de todos os produtos nas doses de 750 + 30 + 2 + 225 g ha-1 de i.a., além dos respectivos tratamentos sem capina. Utilizou-se o cultivar de milho AG 3010 (híbrido duplo, superprecoce, tolerante a inibidores da ALS. Em 2002/2003, avaliou-se a toxicidade a milho e o rendimento, enquanto em 2003/2004 também foi avaliada a eficácia de controle de plantas daninhas. O uso de atrazine isoladamente ou em mistura com clorpirifós não gerou toxicidade às plantas de milho. A adição de clorpirifós à mistura foramsulfuron + iodosulfuron acentuou a injúria ao milho. A inclusão de atrazine simultaneamente à redução dos níveis de foramsulfuron + iodosulfuron permitiu reduzir em parte a injúria a plantas de milho, mantendo o controle de BRAPL e ampliando os níveis de controle de EPHHL.Two trials evaluated corn toxicity and weed control efficacy of the herbicides atrazine, foramsulfuron, and iodosulfuron and the insecticide chlorpyriphos applied at postemergence alone or in mixture. A randomized complete block design was used with four replications. In

  2. 2010 ME70 Workshop (PC1003, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The third leg of the 2010 SEAMAP Reeffish Survey, PC 1003, was originally scheduled as an experimental multibeam sonar workshop. However, on July 12, 2010, FSV...

  3. Software Defined Radio Datalink Implementation Using PC-Type Computers

    National Research Council Canada - National Science Library

    Zafeiropoulos, Georgios

    2003-01-01

    The objective of this thesis was to examine the feasibility of implementation and the performance of a Software Defined Radio datalink, using a common PC type host computer and a high level programming language...

  4. Single-event upset in advanced PowerPC microprocessors

    Science.gov (United States)

    Irom, F.; Swift, G. M.; Farmanesh, F.; Millward, D. G.

    2002-01-01

    Proton and heavy-ion single-event upset susceptibility has been measured for the MotorolaPowerPC7400. The results show that this advanced device has low upset susceptibility, despite the scaling and design advances.

  5. TIPONLINE Code Table

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Coded items are entered in the tiponline data entry program. The codes and their explanations are necessary in order to use the data

  6. Coding for optical channels

    CERN Document Server

    Djordjevic, Ivan; Vasic, Bane

    2010-01-01

    This unique book provides a coherent and comprehensive introduction to the fundamentals of optical communications, signal processing and coding for optical channels. It is the first to integrate the fundamentals of coding theory and optical communication.

  7. ATRAZINE DOES NOT INDUCE GASTROINTESTINAL DISCOMFORT (PICA) IN RATS AT DOSES THAT INCREASE HPA-AXIS ACTIVATION AND CAUSE CONDITIONED TASTE AVERSION.

    Science.gov (United States)

    Previous work has shown that a single oral administration of atrazine (ATR), a chlorotriazine herbicide, induces dose-dependent increases in plasma adrenocorticotropic hormone (ACTH) and serum corticosterone (CORT), with a NOEL equal to 5mg/kg. The mechanism for these effects ...

  8. ATRAZINE DOES NOT INDUCE GASTROINTESTINAL DISCOMFORT (PICA) IN RATS AT DOSES THAT INCREASE ACTH ANDCORTICOSTERONE RELEASE AND CAUSE CONDITIONED TASTE AVERSION.

    Science.gov (United States)

    Previous work has shown that a single oral administration of atrazine (ATR), a chlorotriazine herbicide, induces dose-dependent increases in plasma adrenocorticotropic hormone (ACTH) and serum corticosterone (CORT), with a LOEL of 12.5mg/kg. The mechanism for these effects is unk...

  9. Atrazine transport within a coastal zone in Southeastern Puerto Rico: a sensitivity analysis of an agricultural field model and riparian zone management model

    Science.gov (United States)

    Water quality models are used to predict effects of conservation practices to mitigate the transport of herbicides to water bodies. We used two models - the Agricultural Policy/Environmental eXtender (APEX) and the Riparian Ecosystem Management Model (REMM) to predict the movement of atrazine from ...

  10. Atrazine-induced elevation or attenuation of the LH surge in the ovariectomized, estrogen-primed female rat: role of adrenal progesterone

    Science.gov (United States)

    Multiple daily exposures to the herbicide atrazine have been reported to suppress the surge of luteinizing hormone (LH) in both cycling female rats and those that are ovariectomized (OVX) and exogenously primed with steroids. Additional studies have also found elevations in both ...

  11. Bidirectional impact of atrazine-induced elevations in progesterone (P4) on the LH surge in the ovariectomized, estradiol (E2)-primed rat

    Science.gov (United States)

    Multiple daily exposures to the herbicide atrazine (ATZ) have been reported to suppress the luteinizing hormone surge (LHS) in female rats. Exposure has also been found to elevate P4 concentrations, and an increase in P4 is known to have a different directional effect on LH depe...

  12. Bidirectional impact of atrazine-induced elvations in progesterone (P4) on the LH Surge in the ovariectomized (OVX), estradiol (E2)-primed rat

    Science.gov (United States)

    Multiple daily exposures to the herbicide atrazine (ATZ) have been reported to suppress the luteinizing hormone surge (LHS) in female rats. Exposure has also been found to elevate P4 concentrations, and an increase in P4 is known to have a different directional effect on LH depen...

  13. CoPc and CoPcF16 on gold: Site-specific charge-transfer processes

    Directory of Open Access Journals (Sweden)

    Fotini Petraki

    2014-04-01

    Full Text Available Interface properties of cobalt(II phthalocyanine (CoPc and cobalt(II hexadecafluoro-phthalocyanine (CoPcF16 to gold are investigated by photo-excited electron spectroscopies (X-ray photoemission spectroscopy (XPS, ultraviolet photoemission spectroscopy (UPS and X-ray excited Auger electron spectroscopy (XAES. It is shown that a bidirectional charge transfer determines the interface energetics for CoPc and CoPcF16 on Au. Combined XPS and XAES measurements allow for the separation of chemical shifts based on different local charges at the considered atom caused by polarization effects. This facilitates a detailed discussion of energetic shifts of core level spectra. The data allow the discussion of site-specific charge-transfer processes.

  14. Epitaxial growth and electronic properties of well ordered phthalocyanine heterojunctions MnPc/F{sub 16}CoPc

    Energy Technology Data Exchange (ETDEWEB)

    Lindner, Susi; Mahns, Benjamin; Treske, Uwe; Knupfer, Martin [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Vilkov, Oleg [Center for Physical Methods of Surface Investigation, St. Petersburg State University, Ulyanovskaya Str. 1, St. Petersburg 198504, Russia and Institute of Solid State Physics, University of Technology Dresden, Zellescher Weg 16, D-01062 Dresden (Germany); Haidu, Francisc; Fronk, Michael; Zahn, Dietrich R. T. [Physics Department/Semiconductor Physics, Chemnitz University of Technology, Reichenhainer Str. 70, D-09126 Chemnitz (Germany)

    2014-09-07

    We have prepared phthalocyanine heterojunctions out of MnPc and F{sub 16}CoPc, which were studied by means of X-ray absorption spectroscopy. This heterojunction is characterized by a charge transfer at the interface, resulting in charged MnPc{sup δ} {sup +} and F{sub 16}CoPc{sup δ} {sup −} species. Our data reveal that the molecules are well ordered and oriented parallel to the substrate surface. Furthermore, we demonstrate the filling of the Co 3d{sub z{sup 2}} orbital due to the charge transfer, which supports the explanation of the density functional theory, that the charge transfer is local and affects the metal centers only.

  15. Guest Foreword by Lord Phillips KG PC

    Directory of Open Access Journals (Sweden)

    Nicholas A. Phillips

    2012-04-01

    Full Text Available The Rt Hon The Lord Phillips of Worth Matravers KG PC, President of the Supreme Court of the United Kingdom of Great Britain and Northern Ireland Ambition and excellence. Those two words epitomize Qatar. Under the leadership of his Highness the Emir, this small State has set out to make an impact on the world that belies its size. Ambitious was the plan to have an international broadcasting station. Ambitious was the plan to build from scratch a Museum of Islamic Art. Ambitious was the bid – the successful bid to host the World Cup in 2022. Ambitious is the bid to stage the Olympic Games in 2020. Qatar not merely has ambitions, it realizes its ambitions. And when it does so it is not enough to say that the result is ‘world class’, for Qatar sets out to be a world leader in whatever it puts its hand to. Excellence is the norm. Al Jazeera has established itself as the broadcasting station of choice for many throughout the world. The Doha Museum of Islamic Art is recognized as being second to none. In addition, the scale and standard of development in Doha itself is setting new standards of excellence in the fields of architecture and civil engineering. Thus when Qatar focuses its energies on education and the law, high achievements are expected. I shall have the honour of helping to achieve those expectations when I succeed Lord Woolf as President of Qatar’s new and impressive Civil and Commercial Court. The College of Law at Qatar University is already achieving excellence in the field of legal education. So, naturally, all expect great things of this new International Review of Law and I am delighted to have been invited to welcome it by this foreword. The range of the first edition is both international and topical. Those countries that have experienced the turbulence of the Arab Spring are settling new constitutions, and other countries are bent on constitutional reform designed to avoid such turbulence. So an erudite article on

  16. ARC Code TI: ROC Curve Code Augmentation

    Data.gov (United States)

    National Aeronautics and Space Administration — ROC (Receiver Operating Characteristic) curve Code Augmentation was written by Rodney Martin and John Stutz at NASA Ames Research Center and is a modification of ROC...

  17. Gauge color codes

    DEFF Research Database (Denmark)

    Bombin Palomo, Hector

    2015-01-01

    Color codes are topological stabilizer codes with unusual transversality properties. Here I show that their group of transversal gates is optimal and only depends on the spatial dimension, not the local geometry. I also introduce a generalized, subsystem version of color codes. In 3D they allow...

  18. Refactoring test code

    NARCIS (Netherlands)

    A. van Deursen (Arie); L.M.F. Moonen (Leon); A. van den Bergh; G. Kok

    2001-01-01

    textabstractTwo key aspects of extreme programming (XP) are unit testing and merciless refactoring. Given the fact that the ideal test code / production code ratio approaches 1:1, it is not surprising that unit tests are being refactored. We found that refactoring test code is different from

  19. Effects of tillage and application rate on atrazine transport to subsurface drainage: Evaluation of RZWQM using a six-year field study

    Science.gov (United States)

    Malone, Robert W.; Nolan, Bernard T.; Ma, Liwang; Kanwar, Rameshwar S.; Pederson, Carl H.; Heilman, Philip

    2014-01-01

    Well tested agricultural system models can improve our understanding of the water quality effects of management practices under different conditions. The Root Zone Water Quality Model (RZWQM) has been tested under a variety of conditions. However, the current model's ability to simulate pesticide transport to subsurface drain flow over a long term period under different tillage systems and application rates is not clear. Therefore, we calibrated and tested RZWQM using six years of data from Nashua, Iowa. In this experiment, atrazine was spring applied at 2.8 (1990–1992) and 0.6 kg/ha/yr (1993–1995) to two 0.4 ha plots with different tillage (till and no-till). The observed and simulated average annual flow weighted atrazine concentrations (FWAC) in subsurface drain flow from the no-till plot were 3.7 and 3.2 μg/L, respectively for the period with high atrazine application rates, and 0.8 and 0.9 μg/L, respectively for the period with low application rates. The 1990–1992 observed average annual FWAC difference between the no-till and tilled plot was 2.4 μg/L while the simulated difference was 2.1 μg/L. These observed and simulated differences for 1993–1995 were 0.1 and 0.1 μg/L, respectively. The Nash–Sutcliffe model performance statistic (EF) for cumulative atrazine flux to subsurface drain flow was 0.93 for the no-till plot testing years (1993–1995), which is comparable to other recent model tests. The value of EF is 1.0 when simulated data perfectly match observed data. The order of selected parameter sensitivity for RZWQM simulated FWAC was atrazine partition coefficient > number of macropores > atrazine half life in soil > soil hydraulic conductivity. Simulations from 1990 to 1995 with four different atrazine application rates applied at a constant rate throughout the simulation period showed concentrations in drain flow for the no-till plot to be twice those of the tilled plot. The differences were more pronounced in the early

  20. The Procions` code; Le code Procions

    Energy Technology Data Exchange (ETDEWEB)

    Deck, D.; Samba, G.

    1994-12-19

    This paper presents a new code to simulate plasmas generated by inertial confinement. This multi-kinds kinetic code is done with no angular approximation concerning ions and will work in plan and spherical geometry. First, the physical model is presented, using Fokker-Plank. Then, the numerical model is introduced in order to solve the Fokker-Plank operator under the Rosenbluth form. At the end, several numerical tests are proposed. (TEC). 17 refs., 27 figs.

  1. Salinomycin Exerts Anticancer Effects on PC-3 Cells and PC-3-Derived Cancer Stem Cells In Vitro and In Vivo

    Directory of Open Access Journals (Sweden)

    Yunsheng Zhang

    2017-01-01

    Full Text Available Salinomycin is an antibiotic isolated from Streptomyces albus that selectively kills cancer stem cells (CSCs. However, the antitumor mechanism of salinomycin is unclear. This study investigated the chemotherapeutic efficacy of salinomycin in human prostate cancer PC-3 cells. We found that cytotoxicity of salinomycin to PC-3 cells was stronger than to nonmalignant prostate cell RWPE-1, and exposure to salinomycin induced G2/M phage arrest and apoptosis of PC-3 cells. A mechanistic study found salinomycin suppressed Wnt/β-catenin pathway to induce apoptosis of PC-3 cells. An in vivo experiment confirmed that salinomycin suppressed tumorigenesis in a NOD/SCID mice xenograft model generated from implanted PC-3 cells by inhibiting the Wnt/β-catenin pathway, since the total β-catenin protein level was reduced and the downstream target c-Myc level was significantly downregulated. We also showed that salinomycin, but not paclitaxel, triggered more apoptosis in aldehyde dehydrogenase- (ALDH- positive PC-3 cells, which were considered as the prostate cancer stem cells, suggesting that salinomycin may be a promising chemotherapeutic to target CSCs. In conclusion, this study suggests that salinomycin reduces resistance and relapse of prostate tumor by killing cancer cells as well as CSCs.

  2. Effects of hexazinone and atrazine on the physiology and endocrinology of smolt development in Atlantic salmon

    Science.gov (United States)

    Nieves-Puigdoller, K.; Bjornsson, Bjorn Thrandur; McCormick, S.D.

    2007-01-01

    Exposure to hexazinone (HEX) and atrazine (ATZ), highly mobile and widely used herbicides along rivers in the United States, is potentially harmful to Atlantic salmon, which have been listed as an endangered species. To determine the effects of these contaminants on smolt development, juvenile Atlantic salmon were exposed under flow-through conditions to 100 ??g l-1 HEX, 10 and 100 ??g l-1 ATZ in fresh water (FW) for 21 days at 10 ??C beginning in mid-April. Twelve fish per treatment were sampled in FW, following a 24 h seawater (SW) challenge and after growth for 3 months in SW. Exposure to 100 ??g l-1 HEX or 10 ??g l-1 ATZ caused no mortalities of smolts in FW or after SW challenge, while 9% of the fish exposed to 100 ??g l-1 ATZ died during exposure. Fish exposed to 100 ??g l-1 ATZ reduced feeding after 10 days of exposure and had an impaired growth rate in FW and during the first month in SW; compensatory growth occurred in the second and third month in SW. HEX and ATZ at 10 ??g l-1 exposure had no effect on plasma levels of cortisol, growth hormone (GH), insulin growth factor I (IGF-I), thyroxine (T4) and plasma 3,5,3???-triiodo-l-thyronine (T3), Cl-, Mg2+, Na+, Ca2+ in FW or after SW challenge. FW smolts exposed to 100 ??g l-1 ATZ had decreased plasma Cl-, Mg2+, Na+ and Ca2+ ions and increased cortisol. No effect on plasma levels of GH, IGF-I, T4 or T3 was found in FW smolts exposed to 100 ??g l-1 ATZ. Following SW challenge, fish previously exposed to 100 ??g l-1 ATZ had significant increases in hematocrit, plasma cortisol, Cl-, Mg2+, Na+, Ca2+ and a decrease in T4 and T3. It is concluded that under the conditions imposed in this study, HEX does not affect salinity tolerance of Atlantic salmon smolts, while ATZ causes ionoregulatory, growth and endocrine disturbance. ?? 2007 Elsevier B.V. All rights reserved.

  3. PC Tutor. Bericht uber ein PC-gestutzes Tutorensystem = PC Tutor. Report on a Tutoring System with Personal Computer. ZIFF Papiere 75.

    Science.gov (United States)

    Fritsch, Helmut

    A project was conducted to increase as well as to professionalize communication between tutors and learners in a West German university's distance education program by the use of personal computers. Two tutors worked on the systematic development of a PC-based correcting system. The goal, apart from developing general language skills in English,…

  4. On the Delay Characteristics for Point-to-Point links using Random Linear Network Coding with On-the-fly Coding Capabilities

    DEFF Research Database (Denmark)

    Tömösközi, Máté; Fitzek, Frank; Roetter, Daniel Enrique Lucani

    2014-01-01

    . This metric captures the elapsed time between (network) encoding RTP packets and completely decoding the packets in-order on the receiver side. Our solutions are implemented and evaluated on a point-to-point link between a Raspberry Pi device and a network (de)coding enabled software running on a regular PC...

  5. The materiality of Code

    DEFF Research Database (Denmark)

    Soon, Winnie

    2014-01-01

    , Twitter and Facebook). The focus is not to investigate the functionalities and efficiencies of the code, but to study and interpret the program level of code in order to trace the use of various technological methods such as third-party libraries and platforms’ interfaces. These are important...... to understand the socio-technical side of a changing network environment. Through the study of code, including but not limited to source code, technical specifications and other materials in relation to the artwork production, I would like to explore the materiality of code that goes beyond technical...

  6. Autophagy Regulates Colistin-Induced Apoptosis in PC-12 Cells

    Science.gov (United States)

    Zhang, Ling; Zhao, Yonghao; Ding, Wenjian; Jiang, Guozheng; Lu, Ziyin; Li, Li; Wang, Jinli

    2015-01-01

    Colistin is a cyclic cationic polypeptide antibiotic with activity against multidrug-resistant Gram-negative bacteria. Our recent study demonstrated that colistin induces apoptosis in primary chick cortex neurons and PC-12 cells. Although apoptosis and autophagy have different impacts on cell fate, there is a complex interaction between them. Autophagy plays an important role as a homeostasis regulator by removing excessive or unnecessary proteins and damaged organelles. The aim of the present study was to investigate the modulation of autophagy and apoptosis regulation in PC-12 cells in response to colistin treatment. PC-12 cells were exposed to colistin (125 to 250 μg/ml), and autophagy was detected by visualization of monodansylcadaverine (MDC)-labeled vacuoles, LC3 (microtubule-associated protein 1 light chain 3) immunofluorescence microscopic examination, and Western blotting. Apoptosis was measured by flow cytometry, Hoechst 33258 staining, and Western blotting. Autophagosomes were observed after treatment with colistin for 12 h, and the levels of LC3-II gene expression were determined; observation and protein levels both indicated that colistin induced a high level of autophagy. Colistin treatment also led to apoptosis in PC-12 cells, and the level of caspase-3 expression increased over the 24-h period. Pretreatment of cells with 3-methyladenine (3-MA) increased colistin toxicity in PC-12 cells remarkably. However, rapamycin treatment significantly increased the expression levels of LC3-II and beclin 1 and decreased the rate of apoptosis of PC-12 cells. Our results demonstrate that colistin induced autophagy and apoptosis in PC-12 cells and that the latter was affected by the regulation of autophagy. It is very likely that autophagy plays a protective role in the reduction of colistin-induced cytotoxicity in neurons. PMID:25645826

  7. NASA Lewis Steady-State Heat Pipe Code Architecture

    Science.gov (United States)

    Mi, Ye; Tower, Leonard K.

    2013-01-01

    NASA Glenn Research Center (GRC) has developed the LERCHP code. The PC-based LERCHP code can be used to predict the steady-state performance of heat pipes, including the determination of operating temperature and operating limits which might be encountered under specified conditions. The code contains a vapor flow algorithm which incorporates vapor compressibility and axially varying heat input. For the liquid flow in the wick, Darcy s formula is employed. Thermal boundary conditions and geometric structures can be defined through an interactive input interface. A variety of fluid and material options as well as user defined options can be chosen for the working fluid, wick, and pipe materials. This report documents the current effort at GRC to update the LERCHP code for operating in a Microsoft Windows (Microsoft Corporation) environment. A detailed analysis of the model is presented. The programming architecture for the numerical calculations is explained and flowcharts of the key subroutines are given

  8. DLLExternalCode

    Energy Technology Data Exchange (ETDEWEB)

    2014-05-14

    DLLExternalCode is the a general dynamic-link library (DLL) interface for linking GoldSim (www.goldsim.com) with external codes. The overall concept is to use GoldSim as top level modeling software with interfaces to external codes for specific calculations. The DLLExternalCode DLL that performs the linking function is designed to take a list of code inputs from GoldSim, create an input file for the external application, run the external code, and return a list of outputs, read from files created by the external application, back to GoldSim. Instructions for creating the input file, running the external code, and reading the output are contained in an instructions file that is read and interpreted by the DLL.

  9. Noisy Network Coding

    CERN Document Server

    Lim, Sung Hoon; Gamal, Abbas El; Chung, Sae-Young

    2010-01-01

    A noisy network coding scheme for sending multiple sources over a general noisy network is presented. For multi-source multicast networks, the scheme naturally extends both network coding over noiseless networks by Ahlswede, Cai, Li, and Yeung, and compress-forward coding for the relay channel by Cover and El Gamal to general discrete memoryless and Gaussian networks. The scheme also recovers as special cases the results on coding for wireless relay networks and deterministic networks by Avestimehr, Diggavi, and Tse, and coding for wireless erasure networks by Dana, Gowaikar, Palanki, Hassibi, and Effros. The scheme involves message repetition coding, relay signal compression, and simultaneous decoding. Unlike previous compress--forward schemes, where independent messages are sent over multiple blocks, the same message is sent multiple times using independent codebooks as in the network coding scheme for cyclic networks. Furthermore, the relays do not use Wyner--Ziv binning as in previous compress-forward sch...

  10. Empirically modelled Pc3 activity based on solar wind parameters

    Directory of Open Access Journals (Sweden)

    B. Heilig

    2010-09-01

    Full Text Available It is known that under certain solar wind (SW/interplanetary magnetic field (IMF conditions (e.g. high SW speed, low cone angle the occurrence of ground-level Pc3–4 pulsations is more likely. In this paper we demonstrate that in the event of anomalously low SW particle density, Pc3 activity is extremely low regardless of otherwise favourable SW speed and cone angle. We re-investigate the SW control of Pc3 pulsation activity through a statistical analysis and two empirical models with emphasis on the influence of SW density on Pc3 activity. We utilise SW and IMF measurements from the OMNI project and ground-based magnetometer measurements from the MM100 array to relate SW and IMF measurements to the occurrence of Pc3 activity. Multiple linear regression and artificial neural network models are used in iterative processes in order to identify sets of SW-based input parameters, which optimally reproduce a set of Pc3 activity data. The inclusion of SW density in the parameter set significantly improves the models. Not only the density itself, but other density related parameters, such as the dynamic pressure of the SW, or the standoff distance of the magnetopause work equally well in the model. The disappearance of Pc3s during low-density events can have at least four reasons according to the existing upstream wave theory: 1. Pausing the ion-cyclotron resonance that generates the upstream ultra low frequency waves in the absence of protons, 2. Weakening of the bow shock that implies less efficient reflection, 3. The SW becomes sub-Alfvénic and hence it is not able to sweep back the waves propagating upstream with the Alfvén-speed, and 4. The increase of the standoff distance of the magnetopause (and of the bow shock. Although the models cannot account for the lack of Pc3s during intervals when the SW density is extremely low, the resulting sets of optimal model inputs support the generation of mid latitude Pc3 activity predominantly through

  11. Método alternativo de avaliação da absorção de atrazine por plantas de Brachiaria plantaginea Alternative method for evaluation of atrazine asorption by Brachiaria plantaginea plants

    Directory of Open Access Journals (Sweden)

    C.D.G. Maciel

    2002-12-01

    Full Text Available Dois experimentos foram conduzidos em casa de vegetação da Universidade Estadual de Maringá-PR, objetivando desenvolver metodologia alternativa para avaliar a absorção foliar e radicular de herbicidas. O delineamento experimental utilizado foi o inteiramente casualizado com 11 e 5 tratamentos para os solos arenoso e argiloso, respectivamente, ambos os experimentos com quatro repetições, constituídos por plantas de B. plantaginea em dois estádios. O herbicida atrazine foi aplicado nas doses de 2,5 e 3,0 kg ha¹ em solos arenoso e argiloso, utilizando um pulverizador costal pressurizado por CO2. Os tratamentos foram constituídos por plantas protegidas com canudos plásticos em solo descoberto e plantas desprotegidas em solo coberto com papel-alumínio, associadas a condições de solo seco e úmido, ou em ambas as condições, acrescidas de irrigação de 20 mm apenas ao solo após aplicação. A absorção foliar da atrazine foi eficiente no controle de B. plantaginea com duas a três folhas em solo arenoso e argiloso, ao contrário do estádio de quatro a cinco folhas, onde houve necessidade de associar os efeitos da absorção foliar e radicular para se obter controle satisfatório. A irrigação de 20 mm ampliou o controle da absorção radicular de B. plantaginea em diferentes estádios de plantas, solo e umidade do solo. A metodologia apresentou-se viável como ferramenta alternativa para avaliação da absorção foliar e radicular de herbicidas, no controle de gramíneas em estádio inicial de desenvolvimento.Two trials were carried out at the Universidade Estadual de Maringá, PR-Brazil, to develop an alternative method to evaluate foliar and root absorption of herbicides. A random experimental design was arranged, with eleven or five treatments, for sandy or clay soils, respectively,both with four replicates. Atrazine was applied at rates of 2.5 or 3.0 kg ha-1 in sandy or clay soil samples, respectively, with a CO2-pressured

  12. A novel real-time control system for plasma cutting robot with xPC target

    Directory of Open Access Journals (Sweden)

    Mustafa Soylak

    2016-04-01

    Full Text Available In this article, a novel inexpensive controller system for plasma cutting robots built based on MATLAB xPC is presented. The plasma cutting robot model with 5 degrees of freedom is constructed in the MATLAB/Simulink of the host machine, where the code is generated by real-time workshop and downloaded on the target machine. Two different types of proportional–integral–derivative controllers are applied on the experimental robot manipulator for the real-time plasma cutting process’s trajectory control using this hardware system. First, the performance of a standard proportional–integral–derivative controller is evaluated on this manipulator. Then, a novel proportional–integral–derivative controller structure is used to control the system, and it is compared with a standard proportional–integral–derivative controller. This study shows that the control system for a plasma cutting robot can be established inexpensively, and MATLAB xPC and different controllers can be applied on this system. Moreover, the study concludes that the novel proportional–integral–derivative controller used in this study gives better results for plasma cutting robots than the standard proportional–integral–derivative controller.

  13. Towards one PC for systems with different security levels

    Science.gov (United States)

    Kleidermacher, David N.; Zimmer, Joerg

    Companies and organisations caring about the protection of critical data or critical systems have long struggled with the burden of maintaining separate computers. Commercial grade operating systems and virtualization solutions such as Windows, Linux, and VMware are unsuitable for security assurance to the high levels required for this kind of application sharing on a single PC platform. Custom solutions have failed to gain acceptance as cost containment pressures favour commercial, off-the-shelf (COTS) platforms. In addition, common PC hardware has had serious security limitations that prevent even a high assurance software solution from achieving the required domain separation. The hope for a truly high assurance, multi-level secure PC is coming closer to reality by virtue of recent innovations, both in software and hardware.

  14. Wind tunnel test on PC cable-stayed bridge; PC shachokyo no taifu seino shiken

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Y. [Kyushu Inst. of Technology, Kitakyushu (Japan). Faculty of Engineering

    1997-05-30

    This paper describes the wind tunnel test on a PC cable-stayed bridge. The aerodynamic force that acts on a building is represented by the drag that works in the wind direction, the lift that works perpendicularly to the wind direction, and the aerodynamic moment that causes rotation. In the measurement of wind load, a girder is partially extracted in the wind tunnel and set in a three-component balance, and the drag, lift, and aerodynamic moment are measured using a strain meter while blowing the wind. In a wind tunnel experiment, the similarity on Reynolds number, field number, rigidity, hydraulic force, structural attenuation, and reduced wind velocity is required. However, the wind velocity in the actual bridge uses the same air as that in an experiment. The similarity rule on the Reynolds is not thus satisfied. It is necessary to cause no self-excited vibration (galloping and flutter) as wind-resistant performance and suppress the eddy excitation to less than the allowable amplitude. Moreover, the three-dimensional experiment using an elastic model is conducted in addition to the two-dimensional experiment using a rigid model. In the three-dimensional experiment, various vibration modes that occur in the actual bridge appear. 12 refs., 15 figs.

  15. The Aesthetics of Coding

    DEFF Research Database (Denmark)

    Andersen, Christian Ulrik

    2007-01-01

    Computer art is often associated with computer-generated expressions (digitally manipulated audio/images in music, video, stage design, media facades, etc.). In recent computer art, however, the code-text itself – not the generated output – has become the artwork (Perl Poetry, ASCII Art, obfuscated...... code, etc.). The presentation relates this artistic fascination of code to a media critique expressed by Florian Cramer, claiming that the graphical interface represents a media separation (of text/code and image) causing alienation to the computer’s materiality. Cramer is thus the voice of a new ‘code...... avant-garde’. In line with Cramer, the artists Alex McLean and Adrian Ward (aka Slub) declare: “art-oriented programming needs to acknowledge the conditions of its own making – its poesis.” By analysing the Live Coding performances of Slub (where they program computer music live), the presentation...

  16. Opening up codings?

    DEFF Research Database (Denmark)

    Steensig, Jakob; Heinemann, Trine

    2015-01-01

    doing formal coding and when doing more “traditional” conversation analysis research based on collections. We are more wary, however, of the implication that coding-based research is the end result of a process that starts with qualitative investigations and ends with categories that can be coded......We welcome Tanya Stivers’s discussion (Stivers, 2015/this issue) of coding social interaction and find that her descriptions of the processes of coding open up important avenues for discussion, among other things of the precise ad hoc considerations that researchers need to bear in mind, both when....... Instead we propose that the promise of coding-based research lies in its ability to open up new qualitative questions....

  17. Overview of Code Verification

    Science.gov (United States)

    1983-01-01

    The verified code for the SIFT Executive is not the code that executes on the SIFT system as delivered. The running versions of the SIFT Executive contain optimizations and special code relating to the messy interface to the hardware broadcast interface and to packing of data to conserve space in the store of the BDX930 processors. The running code was in fact developed prior to and without consideration of any mechanical verification. This was regarded as necessary experimentation with the SIFT hardware and special purpose Pascal compiler. The Pascal code sections cover: the selection of a schedule from the global executive broadcast, scheduling, dispatching, three way voting, and error reporting actions of the SIFT Executive. Not included in these sections of Pascal code are: the global executive, five way voting, clock synchronization, interactive consistency, low level broadcasting, and program loading, initialization, and schedule construction.

  18. Feature of extradosed PC bridge and its design; Daihenshin keburu PC kyo no tokucho to sono sekkei

    Energy Technology Data Exchange (ETDEWEB)

    Komiya, M. [Japan Bridge and Structure Institute Inc., Tokyo (Japan)

    1997-03-31

    A PC bridge with the eccentricity of the external cable increased by protruding the deviated member to the outside of the beam for more effective use of the external cable is called a `PC bridge with tendons of large eccentricity.` The extradosed bridge of main beam/cable joint type is a PC bridge with the external cable arranged via a tower-shaped eccentric member provided at the intermediate support, and resembles morphologically a cable stayed bridge having a very low tower. There are two types of extradosed bridges, i.e. a type with concrete coated external cable (cable stayed slab bridge) and the other with non-coated external cable (external cable stayed bridge). Features, structural planning and designing of the general external cable stayed bridge are shown. The features are the possession of intermediate characteristics of those of the PC beam bridge and the PC cable stayed bridge from the viewpoints of structural property, workability, economic efficiency, and scenic property. Outline of the plan, selection of structural data, design of the external cable, and structural characteristics in the ultimate state are discussed. 19 refs., 18 figs., 15 tabs.

  19. Realizing broad-bandwidth visible wavelength photodiode based on solution-processed ZnPc/PC71BM dyad

    Science.gov (United States)

    Zafar, Qayyum; Fatima, Noshin; Karimov, Khasan S.; Ahmed, Muhammad M.; Sulaiman, Khaulah

    2017-02-01

    Herein, we demonstrate a solution-processed visible wavelength organic photodiode (OPD) using donor/acceptor dyad of zinc phthalocyanine (ZnPc) and [6,6]-phenyl-C71-butyric-acid methyl ester (PC71BM), respectively. The synergic absorption profiles of both ZnPc and PC71BM moieties have been exploited to realize broader (350 and 800 nm) and consistent absorption spectrum of the photoactive film. The optimum loading ratio (by volume) of D/A dyad has been estimated to be 1:0.8, via quenching phenomenon in ZnPc photoluminescence spectrum. The performance of the OPD has been evaluated by detecting the photocurrent density with respect to varied illumination levels (0-150 mW/cm2) of impinging light at different reverse bias conditions. Under identical reverse bias mode, the photocurrent density has shown significant upsurge as the incident intensity of light is increased; ultimately leading to the significantly higher responsivity (162.4 μA/W) of the fabricated diode. The light to dark current density ratio (Jph/Jd) of the device at 3 V reverse bias has been calculated to be ∼20.12. The transient photocurrent density response of the fabricated OPD has also been characterized at -4 V operational bias under switch ON/OFF illumination. The measured response and recovery time for the fabricated OPD are ∼200 and 300 ms, respectively.

  20. Physical and Mechanical Characteristics of Kevlar Fiber-Reinforced PC/ABS Composites

    OpenAIRE

    Kuljira Sujirote; Parkpoom Lorjai; Sarawut Rimdusit; Sunan Tiptipakorn

    2012-01-01

    In this research, the composites between polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) alloy and Kevlar fiber were prepared. The flexural and tensile properties of PC/ABS alloy and its composites were determined using a universal testing machine. The synergistic behavior of flexural modulus was observed for all regions of PC contents, while the synergism of flexural strength and tensile strength were found in some PC contents. It was found that the optimum weight ratio of PC:AB...

  1. The Optical Property of Core-Shell Nanosensors and Detection of Atrazine Based on Localized Surface Plasmon Resonance (LSPR Sensing

    Directory of Open Access Journals (Sweden)

    Shaobo Yang

    2014-07-01

    Full Text Available Three different nanosensors with core-shell structures were fabricated by molecular self-assembly and evaporation techniques. Such closely packed nanoparticles exhibit fine optical properties which are useful for biochemical sensing. The refractive index sensitivity (RIS of nanosensors was detected by varying the refractive index of the surrounding medium and the decay length of nanosensors was investigated using a layer-by-layer polyelectrolyte multilayer assembly. The results showed that the thickness of the Au shell plays an important role in determining the RIS and the decay length. A system based on localized surface plasmon resonances (LSPR sensing was constructed in our study. The core-shell nanosensors can detect 10 ng/mL atrazine solutions and are suitable for pesticide residue detection.

  2. The optical property of core-shell nanosensors and detection of atrazine based on localized surface plasmon resonance (LSPR) sensing.

    Science.gov (United States)

    Yang, Shaobo; Wu, Tengfei; Zhao, Xinhua; Li, Xingfei; Tan, Wenbin

    2014-07-23

    Three different nanosensors with core-shell structures were fabricated by molecular self-assembly and evaporation techniques. Such closely packed nanoparticles exhibit fine optical properties which are useful for biochemical sensing. The refractive index sensitivity (RIS) of nanosensors was detected by varying the refractive index of the surrounding medium and the decay length of nanosensors was investigated using a layer-by-layer polyelectrolyte multilayer assembly. The results showed that the thickness of the Au shell plays an important role in determining the RIS and the decay length. A system based on localized surface plasmon resonances (LSPR) sensing was constructed in our study. The core-shell nanosensors can detect 10 ng/mL atrazine solutions and are suitable for pesticide residue detection.

  3. Phonological coding during reading

    Science.gov (United States)

    Leinenger, Mallorie

    2014-01-01

    The exact role that phonological coding (the recoding of written, orthographic information into a sound based code) plays during silent reading has been extensively studied for more than a century. Despite the large body of research surrounding the topic, varying theories as to the time course and function of this recoding still exist. The present review synthesizes this body of research, addressing the topics of time course and function in tandem. The varying theories surrounding the function of phonological coding (e.g., that phonological codes aid lexical access, that phonological codes aid comprehension and bolster short-term memory, or that phonological codes are largely epiphenomenal in skilled readers) are first outlined, and the time courses that each maps onto (e.g., that phonological codes come online early (pre-lexical) or that phonological codes come online late (post-lexical)) are discussed. Next the research relevant to each of these proposed functions is reviewed, discussing the varying methodologies that have been used to investigate phonological coding (e.g., response time methods, reading while eyetracking or recording EEG and MEG, concurrent articulation) and highlighting the advantages and limitations of each with respect to the study of phonological coding. In response to the view that phonological coding is largely epiphenomenal in skilled readers, research on the use of phonological codes in prelingually, profoundly deaf readers is reviewed. Finally, implications for current models of word identification (activation-verification model (Van Order, 1987), dual-route model (e.g., Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001), parallel distributed processing model (Seidenberg & McClelland, 1989)) are discussed. PMID:25150679

  4. The aeroelastic code FLEXLAST

    Energy Technology Data Exchange (ETDEWEB)

    Visser, B. [Stork Product Eng., Amsterdam (Netherlands)

    1996-09-01

    To support the discussion on aeroelastic codes, a description of the code FLEXLAST was given and experiences within benchmarks and measurement programmes were summarized. The code FLEXLAST has been developed since 1982 at Stork Product Engineering (SPE). Since 1992 FLEXLAST has been used by Dutch industries for wind turbine and rotor design. Based on the comparison with measurements, it can be concluded that the main shortcomings of wind turbine modelling lie in the field of aerodynamics, wind field and wake modelling. (au)

  5. Identification and Functional Characterization of G6PC2 Coding Variants Influencing Glycemic Traits Define an Effector Transcript at the G6PC2-ABCB11 Locus

    OpenAIRE

    Anubha Mahajan; Xueling Sim; Hui Jin Ng; Alisa Manning; Rivas, Manuel A.; Highland, Heather M; Locke, Adam E.; Niels Grarup; Hae Kyung Im; Pablo Cingolani; Jason Flannick; Pierre Fontanillas; Christian Fuchsberger; Gaulton, Kyle J; Teslovich, Tanya M.

    2017-01-01

    Genome wide association studies (GWAS) for fasting glucose (FG) and insulin (FI) have identified common variant signals which explain 4.8% and 1.2% of trait variance, respectively. It is hypothesized that low-frequency and rare variants could contribute substantially to unexplained genetic variance. To test this, we analyzed exome-array data from up to 33,231 non-diabetic individuals of European ancestry. We found exome-wide significant (P<5×10-7) evidence for two loci not previously highl...

  6. The Local White Dwarf Population: The 25 pc Sample

    Science.gov (United States)

    Holberg, Jay B.; Sion, E. M.; Oswalt, T. D.

    2011-01-01

    Currently the most complete sample of white dwarf stars comes from the local white dwarf population within 20 pc, which is believed to be 80 percent complete. This sample contains some 132 degenerate stars. We hope to effectively double the number of known local white dwarfs by extending the sample boundary to 25 pc, while still maintaining a high level of completeness. We discuss plans for extending the local sample and some of the studies that will be possible with this enlarged population. This work was funded in part by NSF Grant AST-1008845.

  7. PC Based Linear Variable Differential Displacement Measurement Uses Optical Technique

    Directory of Open Access Journals (Sweden)

    Tapan Kumar MAITI

    2007-07-01

    Full Text Available PC based linear variable differential displacement (LVDD measurement with optical approach has been presented. The technique is a good blending of both hardware and software and is basically an alternative method of linear variable differential transformer (LVDT. A visual basic (VB programming is used for this PC based measurement. Here the voltage output and the displacement of the reflector can be studied and stored continuously. Theoretical predictions are supported by experimental results. This technique can be used for the measurement of some non-electrical parameters e.g. force, torque and liquid level etc.

  8. Data Communication PC/NaI-borehole probe (Hardware & Software)

    DEFF Research Database (Denmark)

    Madsen, Peter Buch

    Development of new hard- & software to a NaI borehole probe on a PC. Save data from the probe each 10'th sec, handle the data from the probe and make calculations every 10'th sec and show the results on the monitor.......Development of new hard- & software to a NaI borehole probe on a PC. Save data from the probe each 10'th sec, handle the data from the probe and make calculations every 10'th sec and show the results on the monitor....

  9. Generating code adapted for interlinking legacy scalar code and extended vector code

    Science.gov (United States)

    Gschwind, Michael K

    2013-06-04

    Mechanisms for intermixing code are provided. Source code is received for compilation using an extended Application Binary Interface (ABI) that extends a legacy ABI and uses a different register configuration than the legacy ABI. First compiled code is generated based on the source code, the first compiled code comprising code for accommodating the difference in register configurations used by the extended ABI and the legacy ABI. The first compiled code and second compiled code are intermixed to generate intermixed code, the second compiled code being compiled code that uses the legacy ABI. The intermixed code comprises at least one call instruction that is one of a call from the first compiled code to the second compiled code or a call from the second compiled code to the first compiled code. The code for accommodating the difference in register configurations is associated with the at least one call instruction.

  10. Decoding of Cyclic Codes,

    Science.gov (United States)

    INFORMATION THEORY, *DECODING), (* DATA TRANSMISSION SYSTEMS , DECODING), STATISTICAL ANALYSIS, STOCHASTIC PROCESSES, CODING, WHITE NOISE, NUMBER THEORY, CORRECTIONS, BINARY ARITHMETIC, SHIFT REGISTERS, CONTROL SYSTEMS, USSR

  11. ARC Code TI: ACCEPT

    Data.gov (United States)

    National Aeronautics and Space Administration — ACCEPT consists of an overall software infrastructure framework and two main software components. The software infrastructure framework consists of code written to...

  12. Diameter Perfect Lee Codes

    CERN Document Server

    Horak, Peter

    2011-01-01

    Lee codes have been intensively studied for more than 40 years. Interest in these codes has been triggered by the Golomb-Welch conjecture on the existence of perfect error-correcting Lee codes. In this paper we deal with the existence and enumeration of diameter perfect Lee codes. As main results we determine all q for which there exists a linear diameter-4 perfect Lee code of word length n over Z_{q}, and prove that for each n\\geq3 there are unaccountably many diameter-4 perfect Lee codes of word length n over Z. This is in a strict contrast with perfect error-correcting Lee codes of word length n over Z as there is a unique such code for n=3, and its is conjectured that this is always the case when 2n+1 is a prime. Diameter perfect Lee codes will be constructed by an algebraic construction that is based on a group homomorphism. This will allow us to design an efficient algorithm for their decoding.

  13. Expander chunked codes

    Science.gov (United States)

    Tang, Bin; Yang, Shenghao; Ye, Baoliu; Yin, Yitong; Lu, Sanglu

    2015-12-01

    Chunked codes are efficient random linear network coding (RLNC) schemes with low computational cost, where the input packets are encoded into small chunks (i.e., subsets of the coded packets). During the network transmission, RLNC is performed within each chunk. In this paper, we first introduce a simple transfer matrix model to characterize the transmission of chunks and derive some basic properties of the model to facilitate the performance analysis. We then focus on the design of overlapped chunked codes, a class of chunked codes whose chunks are non-disjoint subsets of input packets, which are of special interest since they can be encoded with negligible computational cost and in a causal fashion. We propose expander chunked (EC) codes, the first class of overlapped chunked codes that have an analyzable performance, where the construction of the chunks makes use of regular graphs. Numerical and simulation results show that in some practical settings, EC codes can achieve rates within 91 to 97 % of the optimum and outperform the state-of-the-art overlapped chunked codes significantly.

  14. QR codes for dummies

    CERN Document Server

    Waters, Joe

    2012-01-01

    Find out how to effectively create, use, and track QR codes QR (Quick Response) codes are popping up everywhere, and businesses are reaping the rewards. Get in on the action with the no-nonsense advice in this streamlined, portable guide. You'll find out how to get started, plan your strategy, and actually create the codes. Then you'll learn to link codes to mobile-friendly content, track your results, and develop ways to give your customers value that will keep them coming back. It's all presented in the straightforward style you've come to know and love, with a dash of humor thrown

  15. Atrazine degradation using chemical-free process of USUV: Analysis of the micro-heterogeneous environments and the degradation mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Xu, L.J., E-mail: xulijie827@gmail.com [Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Chu, W., E-mail: cewchu@polyu.edu.hk [Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Graham, Nigel, E-mail: n.graham@imperial.ac.uk [Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom)

    2014-06-30

    Graphical abstract: - Highlights: • Two chemical-free AOP processes are combined to enhance atrazine degradation. • ATZ degradation in sonophotolytic process was analyzed using a previous proposed model. • The micro-bubble/liquid heterogeneous environments in sonolytic processes were investigated. • The salt effects on different sonolytic processes were examined. • ATZ degradation mechanisms were investigated and pathways were proposed. - Abstract: The effectiveness of sonolysis (US), photolysis (UV), and sonophotolysis (USUV) for the degradation of atrazine (ATZ) was investigated. An untypical kinetics analysis was found useful to describe the combined process, which is compatible to pseudo first-order kinetics. The heterogeneous environments of two different ultrasounds (20 and 400 kHz) were evaluated. The heterogeneous distribution of ATZ in the ultrasonic solution was found critical in determining the reaction rates at different frequencies. The presence of NaCl would promote/inhibit the rates by the growth and decline of “salting out” effect and surface tension. The benefits of combining these two processes were for the first time investigated from the aspect of promoting the intermediates degradation which were resistant in individual processes. UV caused a rapid transformation of ATZ to 2-hydroxyatrazine (OIET), which was insensitive to UV irradiation; however, US and USUV were able to degrade OIET and other intermediates through • OH attack. On the other hand, UV irradiation also could promote radical generation via H{sub 2}O{sub 2} decomposition, thereby resulting in less accumulation of more hydrophilic intermediates, which are difficult to degradation in the US process. Reaction pathways for ATZ degradation by all three processes are proposed. USUV achieved the greatest degree of ATZ mineralization with more than 60% TOC removed, contributed solely by the oxidation of side chains. Ammeline was found to be the only end-product in both US

  16. New competitive dendrimer-based and highly selective immunosensor for determination of atrazine in environmental, feed and food samples: the importance of antibody selectivity for discrimination among related triazinic metabolites.

    Science.gov (United States)

    Giannetto, Marco; Umiltà, Eleonora; Careri, Maria

    2014-01-02

    A new voltammetric competitive immunosensor selective for atrazine, based on the immobilization of a conjugate atrazine-bovine serum albumine on a nanostructured gold substrate previously functionalized with poliamidoaminic dendrimers, was realized, characterized, and validated in different real samples of environmental and food concern. Response of the sensor was reliable, highly selective and suitable for the detection and quantification of atrazine at trace levels in complex matrices such as territorial waters, corn-cultivated soils, corn-containing poultry and bovine feeds and corn flakes for human use. Selectivity studies were focused on desethylatrazine, the principal metabolite generated by long-term microbiological degradation of atrazine, terbutylazine-2-hydroxy and simazine as potential interferents. The response of the developed immunosensor for atrazine was explored over the 10(-2)-10(3) ng mL(-1) range. Good sensitivity was proved, as limit of detection and limit of quantitation of 1.2 and 5 ng mL(-1), respectively, were estimated for atrazine. RSD values <5% over the entire explored range attested a good precision of the device. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Quality assessment of platelet concentrates prepared by platelet rich plasma-platelet concentrate, buffy coat poor-platelet concentrate (BC-PC and apheresis-PC methods

    Directory of Open Access Journals (Sweden)

    Singh Ravindra

    2009-01-01

    Full Text Available Background: Platelet rich plasma-platelet concentrate (PRP-PC, buffy coat poor-platelet concentrate (BC-PC, and apheresis-PC were prepared and their quality parameters were assessed. Study Design: In this study, the following platelet products were prepared: from random donor platelets (i platelet rich plasma - platelet concentrate (PRP-PC, and (ii buffy coat poor- platelet concentrate (BC-PC and (iii single donor platelets (apheresis-PC by different methods. Their quality was assessed using the following parameters: swirling, volume of the platelet concentrate, platelet count, WBC count and pH. Results: A total of 146 platelet concentrates (64 of PRP-PC, 62 of BC-PC and 20 of apheresis-PC were enrolled in this study. The mean volume of PRP-PC, BC-PC and apheresis-PC was 62.30±22.68 ml, 68.81±22.95 ml and 214.05±9.91 ml and ranged from 22-135 ml, 32-133 ml and 200-251 ml respectively. The mean platelet count of PRP-PC, BC-PC and apheresis-PC was 7.6±2.97 x 1010/unit, 7.3±2.98 x 1010/unit and 4.13±1.32 x 1011/unit and ranged from 3.2-16.2 x 1010/unit, 0.6-16.4 x 1010/unit and 1.22-8.9 x 1011/unit respectively. The mean WBC count in PRP-PC (n = 10, BC-PC (n = 10 and apheresis-PC (n = 6 units was 4.05±0.48 x 107/unit, 2.08±0.39 x 107/unit and 4.8±0.8 x 106/unit and ranged from 3.4 -4.77 x 107/unit, 1.6-2.7 x 107/unit and 3.2 - 5.2 x 106/unit respectively. A total of 26 units were analyzed for pH changes. Out of these units, 10 each were PRP-PC and BC-PC and 6 units were apheresis-PC. Their mean pH was 6.7±0.26 (mean±SD and ranged from 6.5 - 7.0 and no difference was observed among all three types of platelet concentrate. Conclusion: PRP-PC and BC-PC units were comparable in terms of swirling, platelet count per unit and pH. As expected, we found WBC contamination to be less in BC-PC than PRP-PC units. Variation in volume was more in BC-PC than PRP-PC units and this suggests that further standardization is required for preparation of BC-PC

  18. On {\\sigma}-LCD codes

    OpenAIRE

    Carlet, Claude; Mesnager, Sihem; Tang, Chunming; Qi, Yanfeng

    2017-01-01

    Linear complementary pairs (LCP) of codes play an important role in armoring implementations against side-channel attacks and fault injection attacks. One of the most common ways to construct LCP of codes is to use Euclidean linear complementary dual (LCD) codes. In this paper, we first introduce the concept of linear codes with $\\sigma$ complementary dual ($\\sigma$-LCD), which includes known Euclidean LCD codes, Hermitian LCD codes, and Galois LCD codes. As Euclidean LCD codes, $\\sigma$-LCD ...

  19. New developments in the Saphire computer codes

    Energy Technology Data Exchange (ETDEWEB)

    Russell, K.D.; Wood, S.T.; Kvarfordt, K.J. [Idaho Engineering Lab., Idaho Falls, ID (United States)] [and others

    1996-03-01

    The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a suite of computer programs that were developed to create and analyze a probabilistic risk assessment (PRA) of a nuclear power plant. Many recent enhancements to this suite of codes have been made. This presentation will provide an overview of these features and capabilities. The presentation will include a discussion of the new GEM module. This module greatly reduces and simplifies the work necessary to use the SAPHIRE code in event assessment applications. An overview of the features provided in the new Windows version will also be provided. This version is a full Windows 32-bit implementation and offers many new and exciting features. [A separate computer demonstration was held to allow interested participants to get a preview of these features.] The new capabilities that have been added since version 5.0 will be covered. Some of these major new features include the ability to store an unlimited number of basic events, gates, systems, sequences, etc.; the addition of improved reporting capabilities to allow the user to generate and {open_quotes}scroll{close_quotes} through custom reports; the addition of multi-variable importance measures; and the simplification of the user interface. Although originally designed as a PRA Level 1 suite of codes, capabilities have recently been added to SAPHIRE to allow the user to apply the code in Level 2 analyses. These features will be discussed in detail during the presentation. The modifications and capabilities added to this version of SAPHIRE significantly extend the code in many important areas. Together, these extensions represent a major step forward in PC-based risk analysis tools. This presentation provides a current up-to-date status of these important PRA analysis tools.

  20. Orpinomyces cellulase celf protein and coding sequences

    Science.gov (United States)

    Li, Xin-Liang; Chen, Huizhong; Ljungdahl, Lars G.

    2000-09-05

    A cDNA (1,520 bp), designated celF, consisting of an open reading frame (ORF) encoding a polypeptide (CelF) of 432 amino acids was isolated from a cDNA library of the anaerobic rumen fungus Orpinomyces PC-2 constructed in Escherichia coli. Analysis of the deduced amino acid sequence showed that starting from the N-terminus, CelF consists of a signal peptide, a cellulose binding domain (CBD) followed by an extremely Asn-rich linker region which separate the CBD and the catalytic domains. The latter is located at the C-terminus. The catalytic domain of CelF is highly homologous to CelA and CelC of Orpinomyces PC-2, to CelA of Neocallimastix patriciarum and also to cellobiohydrolase IIs (CBHIIs) from aerobic fungi. However, Like CelA of Neocallimastix patriciarum, CelF does not have the noncatalytic repeated peptide domain (NCRPD) found in CelA and CelC from the same organism. The recombinant protein CelF hydrolyzes cellooligosaccharides in the pattern of CBHII, yielding only cellobiose as product with cellotetraose as the substrate. The genomic celF is interrupted by a 111 bp intron, located within the region coding for the CBD. The intron of the celF has features in common with genes from aerobic filamentous fungi.

  1. Molecular cloning and expression of prohormone convertases PC1 and PC2 in the pituitary gland of the bullfrog, Rana catesbeiana.

    Science.gov (United States)

    Yaoi, Yuichi; Suzuki, Masakazu; Tomura, Hideaki; Kikuyama, Sakae; Tanaka, Shigeyasu

    2003-09-01

    We cloned cDNAs encoding PC1 and PC2 from a cDNA library constructed for the anterior pituitary gland of the bullfrog (Rana catesbeiana) and sequenced them. The bullfrog PC1 cDNA consisted of 2972 base pairs (bp) with an open reading frame of 2208 bp and encoded a protein of 736 amino acids, including a putative signal peptide of 26 amino acids. The protein showed a high homology to R. ridibunda PC1 (95.1%) and mammalian PC1 (72.6%). The bullfrog PC2 cDNA consisted of 2242 bp with an open reading frame of 1914 bp and encoded a protein of 638 amino acids, including a putative signal peptide of 23 amino acids. This protein showed a high homology to R. ridibunda PC2 (95.5%) and mammalian PC2 (84.8%). The catalytic triad of serine proteinases of the subtilisin family was found at Asp-168, His-209, and Ser-383 in the PC1 protein and at Asp-167, His-208, and Ser-384 in the PC2 protein. In situ hybridization staining revealed that PC2 mRNA was detected in corticotrope cells of the tadpoles, but not in those of the adults. In the adult, only PC1 mRNA was detected in the pars distalis but both PC1 and PC2 mRNAs were detected in the pars intermedia. The data also showed that PC1 mRNA was expressed in gonadotrope cells.

  2. Charge transfer at F{sub 16}CoPc and CoPc interfaces to Au

    Energy Technology Data Exchange (ETDEWEB)

    Lindner, Susi; Treske, Uwe; Grobosch, Mandy; Knupfer, Martin [IFW Dresden (Germany)

    2011-12-15

    We analyze the electronic properties of the interfaces between cobalt phthalocyanine (CoPc), as well as fluorinated cobalt phthalocyanine (F{sub 16}CoPc), and an Au(100) single-crystal using X-ray photoemission spectroscopy and valence band ultraviolet photoemission spectroscopy. Our data demonstrate that for the monolayers of both materials a charge transfer occurs from the substrate to the center of the organic molecules resulting in a central Co(I) ion. This leads to the conclusion that this effect essentially is fluorination- and ligand-independent. (orig.)

  3. Application of sPC-SAFT and group contribution sPC-SAFT to polymer systems-Capabilities and limitations

    DEFF Research Database (Denmark)

    Tihic, Amra; von Solms, Nicolas; Michelsen, Michael Locht

    2009-01-01

    PC-SAFT model, with and without GC. The reported results contribute to a better understanding of the applicability of the sPC-SAFT model to binary polymer mixtures, and identify both models as good predictive tools for several industrial applications. Limitations are also identified and discussed....... predictive capability of the model demonstrates satisfactory description of the fluid behaviour of several polymer systems, including both vapour-liquid equilibria and liquid-liquid equilibria. This work continues the systematic study on phase behaviour of polymer systems with the two versions of the s...

  4. Scrum Code Camps

    DEFF Research Database (Denmark)

    Pries-Heje, Jan; Pries-Heje, Lene; Dahlgaard, Bente

    2013-01-01

    is required. In this paper we present the design of such a new approach, the Scrum Code Camp, which can be used to assess agile team capability in a transparent and consistent way. A design science research approach is used to analyze properties of two instances of the Scrum Code Camp where seven agile teams...

  5. Error Correcting Codes

    Indian Academy of Sciences (India)

    be fixed to define codes over such domains). New decoding schemes that take advantage of such connections can be devised. These may soon show up in a technique called code division multiple access (CDMA) which is proposed as a basis for digital cellular communication. CDMA provides a facility for many users to ...

  6. Codes of Conduct

    Science.gov (United States)

    Million, June

    2004-01-01

    Most schools have a code of conduct, pledge, or behavioral standards, set by the district or school board with the school community. In this article, the author features some schools that created a new vision of instilling code of conducts to students based on work quality, respect, safety and courtesy. She suggests that communicating the code…

  7. Error Correcting Codes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 3. Error Correcting Codes - Reed Solomon Codes. Priti Shankar. Series Article Volume 2 Issue 3 March 1997 pp 33-47. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/002/03/0033-0047 ...

  8. Code Generation = A* + BURS

    NARCIS (Netherlands)

    Nymeyer, Albert; Katoen, Joost P.; Westra, Ymte; Alblas, H.; Gyimóthy, Tibor

    1996-01-01

    A system called BURS that is based on term rewrite systems and a search algorithm A* are combined to produce a code generator that generates optimal code. The theory underlying BURS is re-developed, formalised and explained in this work. The search algorithm uses a cost heuristic that is derived

  9. Dress Codes for Teachers?

    Science.gov (United States)

    Million, June

    2004-01-01

    In this article, the author discusses an e-mail survey of principals from across the country regarding whether or not their school had a formal staff dress code. The results indicate that most did not have a formal dress code, but agreed that professional dress for teachers was not only necessary, but showed respect for the school and had a…

  10. Informal control code logic

    NARCIS (Netherlands)

    Bergstra, J.A.

    2010-01-01

    General definitions as well as rules of reasoning regarding control code production, distribution, deployment, and usage are described. The role of testing, trust, confidence and risk analysis is considered. A rationale for control code testing is sought and found for the case of safety critical

  11. Interleaved Product LDPC Codes

    OpenAIRE

    Baldi, Marco; Cancellieri, Giovanni; Chiaraluce, Franco

    2011-01-01

    Product LDPC codes take advantage of LDPC decoding algorithms and the high minimum distance of product codes. We propose to add suitable interleavers to improve the waterfall performance of LDPC decoding. Interleaving also reduces the number of low weight codewords, that gives a further advantage in the error floor region.

  12. Nuremberg code turns 60

    OpenAIRE

    Thieren, Michel; Mauron, Alexandre

    2007-01-01

    This month marks sixty years since the Nuremberg code – the basic text of modern medical ethics – was issued. The principles in this code were articulated in the context of the Nuremberg trials in 1947. We would like to use this anniversary to examine its ability to address the ethical challenges of our time.

  13. Error Correcting Codes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 1. Error Correcting Codes The Hamming Codes. Priti Shankar. Series Article Volume 2 Issue 1 January ... Author Affiliations. Priti Shankar1. Department of Computer Science and Automation, Indian Institute of Science, Bangalore 560 012, India ...

  14. CLIPS - C LANGUAGE INTEGRATED PRODUCTION SYSTEM (IBM PC VERSION WITH CLIPSITS)

    Science.gov (United States)

    Riley, , .

    1994-01-01

    The C Language Integrated Production System, CLIPS, is a shell for developing expert systems. It is designed to allow artificial intelligence research, development, and delivery on conventional computers. The primary design goals for CLIPS are portability, efficiency, and functionality. For these reasons, the program is written in C. CLIPS meets or outperforms most micro- and minicomputer based artificial intelligence tools. CLIPS is a forward chaining rule-based language. The program contains an inference engine and a language syntax that provide a framework for the construction of an expert system. It also includes tools for debugging an application. CLIPS is based on the Rete algorithm, which enables very efficient pattern matching. The collection of conditions and actions to be taken if the conditions are met is constructed into a rule network. As facts are asserted either prior to or during a session, CLIPS pattern-matches the number of fields. Wildcards and variables are supported for both single and multiple fields. CLIPS syntax allows the inclusion of externally defined functions (outside functions which are written in a language other than CLIPS). CLIPS itself can be embedded in a program such that the expert system is available as a simple subroutine call. Advanced features found in CLIPS version 4.3 include an integrated microEMACS editor, the ability to generate C source code from a CLIPS rule base to produce a dedicated executable, binary load and save capabilities for CLIPS rule bases, and the utility program CRSV (Cross-Reference, Style, and Verification) designed to facilitate the development and maintenance of large rule bases. Five machine versions are available. Each machine version includes the source and the executable for that machine. The UNIX version includes the source and binaries for IBM RS/6000, Sun3 series, and Sun4 series computers. The UNIX, DEC VAX, and DEC RISC Workstation versions are line oriented. The PC version and the Macintosh

  15. PC Based Display for Sonar Applications: A Design Experience

    OpenAIRE

    G. Miny; Anney Morris; M.A. Jayendran; A. Unnikrishnan

    1994-01-01

    An attempt was made to standardise the hardware and the software used for the sonar display systems. The idea of standardise hardware suggested itself in using an IBM-compatible PC AT which configures with an Intel 80386 CPU and a standard VGA display adapter card. The software consists of Intel assembly procedures embedded in a PASCAL (turbo 4.0) environment.

  16. Porphyrin-phthalocyanine nanorods (P-PcNR) formed by ...

    African Journals Online (AJOL)

    ... tetra {2,(3)-(2-mercaptopyridine) phthalocyaninato}(MTSPyPc). The transmission electron microscope (TEM) images of the colloid suspension of the aggregate confirmed formation of nanorods while their electron spectra showed that the molecules formed J-aggregation. Keywords: Porphyrin, Phthalocyanine, Nanorods, ...

  17. Level of personal computer (PC) tablet penetration among ...

    African Journals Online (AJOL)

    This study was designed to find out level of Personal Computer (PC) tablet penetration among undergraduate students of university of Ilorin, Ilorin, Nigeria. Random sampling technique was adopted to select 200 students from selected Faculties in University of Ilorin. The questionnaire were administered, collected and ...

  18. Comparison between a newly developed PC-based Doppler ...

    African Journals Online (AJOL)

    Objectives. To determine the accuracy of the resistance index (RI) of flow velocity waveforms of the umbilical artery measured using a newly developed PC-based continuous wave Doppler device (Umbiflow) with regard to systematic and random variations when compared with a commercial standard (Vasoflow). Design.

  19. Privacy Impact Assessment for the PC Label System

    Science.gov (United States)

    The PC Label System collects contact information for individuals with an interest in EPA's Region 1. Learn how this data will be collected in the system, how it will be used, access to the data, the purpose of data collection, and record retention policies

  20. Mathematics Programming on the Apple II and IBM PC.

    Science.gov (United States)

    Myers, Roy E.; Schneider, David I.

    1987-01-01

    Details the features of BASIC used in mathematics programming and provides the information needed to translate between the Apple II and IBM PC computers. Discusses inputing a user-defined function, setting scroll windows, displaying subscripts and exponents, variable names, mathematical characters and special symbols. (TW)

  1. A PC-based Workstation for Robotic Discectomy

    Science.gov (United States)

    Casadei, C.; Fiorini, P.; Martelli, S.; Montanari, M.; Morri, A.

    1998-01-01

    Ths paper describes a PC-based controller for robot-assisted minimally invasive surgery. The development is motivated by the need of reducing the exposure of operating room personnel to X-rays during surgical procedures such as percutanrous discectomy.

  2. Photodynamic inactivation of Candida albicans by BAM-SiPc.

    Science.gov (United States)

    So, Cheung-Wai; Tsang, Paul W K; Lo, Pui-Chi; Seneviratne, C J; Samaranayake, Lakshman P; Fong, Wing-Ping

    2010-05-01

    Photodynamic therapy is a treatment that combines the use of three non-toxic components, viz. photosensitiser, light and oxygen to cause localised oxidative photodamage. In the present study, the antifungal effect of the photosensitiser, BAM-SiPc, an unsymmetrical bisamino phthalocyanine, was investigated. BAM-SiPc was effective in photo-inactivating Candida albicans in a dose-dependent manner. The cell viability as determined by the clonogenic assay was reduced to c. 10% at 0.02 micromol l(-1) BAM-SiPc with a total fluence of 12 J cm(-2) at a cell density of 10(7) cells ml(-1). A short incubation time of 5-15 min was sufficient to allow the photosensitiser to exert its optimal antifungal activity. Microscopical analysis showed that BAM-SiPc was effectively internalised by the fungal cells. Photodynamic treatment led to an increase in the intracellular reactive oxygen species level and disturbed the membrane integrity of the fungal cells.

  3. Evaluation Codes from an Affine Veriety Code Perspective

    DEFF Research Database (Denmark)

    Geil, Hans Olav

    2008-01-01

    Evaluation codes (also called order domain codes) are traditionally introduced as generalized one-point geometric Goppa codes. In the present paper we will give a new point of view on evaluation codes by introducing them instead as particular nice examples of affine variety codes. Our study...... . . . . . . . . . . . . . . . . . . . . . . . 171 4.9 Codes form order domains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 4.10 One-point geometric Goppa codes . . . . . . . . . . . . . . . . . . . . . . . . 176 4.11 Bibliographical Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 References...

  4. Quantum Synchronizable Codes From Quadratic Residue Codes and Their Supercodes

    OpenAIRE

    Xie, Yixuan; Yuan, Jinhong; Fujiwara, Yuichiro

    2014-01-01

    Quantum synchronizable codes are quantum error-correcting codes designed to correct the effects of both quantum noise and block synchronization errors. While it is known that quantum synchronizable codes can be constructed from cyclic codes that satisfy special properties, only a few classes of cyclic codes have been proved to give promising quantum synchronizable codes. In this paper, using quadratic residue codes and their supercodes, we give a simple construction for quantum synchronizable...

  5. Improved classical and quantum random access codes

    Science.gov (United States)

    Liabøtrø, O.

    2017-05-01

    A (quantum) random access code ((Q)RAC) is a scheme that encodes n bits into m (qu)bits such that any of the n bits can be recovered with a worst case probability p >1/2 . We generalize (Q)RACs to a scheme encoding n d -levels into m (quantum) d -levels such that any d -level can be recovered with the probability for every wrong outcome value being less than 1/d . We construct explicit solutions for all n ≤d/2m-1 d -1 . For d =2 , the constructions coincide with those previously known. We show that the (Q)RACs are d -parity oblivious, generalizing ordinary parity obliviousness. We further investigate optimization of the success probabilities. For d =2 , we use the measure operators of the previously best-known solutions, but improve the encoding states to give a higher success probability. We conjecture that for maximal (n =4m-1 ,m ,p ) QRACs, p =1/2 {1 +[(√{3}+1)m-1 ] -1} is possible, and show that it is an upper bound for the measure operators that we use. We then compare (n ,m ,pq) QRACs with classical (n ,2 m ,pc) RACs. We can always find pq≥pc , but the classical code gives information about every input bit simultaneously, while the QRAC only gives information about a subset. For several different (n ,2 ,p ) QRACs, we see the same trade-off, as the best p values are obtained when the number of bits that can be obtained simultaneously is as small as possible. The trade-off is connected to parity obliviousness, since high certainty information about several bits can be used to calculate probabilities for parities of subsets.

  6. Application of poly(epsilon-caprolactone) nanoparticles containing atrazine herbicide as an alternative technique to control weeds and reduce damage to the environment.

    Science.gov (United States)

    Pereira, Anderson E S; Grillo, Renato; Mello, Nathalie F S; Rosa, Andre H; Fraceto, Leonardo F

    2014-03-15

    Nanoparticles of poly(epsilon-caprolactone) containing the herbicide atrazine were prepared, characterized, and evaluated in terms of their herbicidal activity and genotoxicity. The stability of the nanoparticles was evaluated over a period of three months, considering the variables: size, polydispersion index, pH, and encapsulation efficiency. Tests on plants were performed with target (Brassica sp.) and non-target (Zea mays) organisms, and the nanoparticle formulations were shown to be effective for the control of the target species. Experiments using soil columns revealed that the use of nanoparticles reduced the mobility of atrazine in the soil. Application of the Allium cepa chromosome aberration assay demonstrated that the nanoparticle systems were able to reduce the genotoxicity of the herbicide. The formulations developed offer a useful means of controlling agricultural weeds, while at the same time reducing the risk of harm to the environment and human health. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. The Redox-Active Chromium Phthalocyanine System: Isolation of Five Oxidation States from Pc(4-) Cr(I) to Pc(2-) Cr(III).

    Science.gov (United States)

    Zhou, Wen; Thompson, John R; Leznoff, Clifford C; Leznoff, Daniel B

    2017-02-16

    The preparation and structural characterization of a series of chromium phthalocyanine complexes with multiple metal and ring oxidation states were achieved using PcCr(II) (1) (Pc=phthalocyanine) or PcCr(II) (THF)2 (1⋅THF2 ) as starting materials. The reaction of soluble 1⋅THF2 with Br2 or I2 gave the PcCr(III) halide complexes PcCrX(THF) (X=I/I3 , Br; 3, 4, respectively). Treatment of 1 with 0.5 equivalent of PhIO or air generated the dinuclear [PcCr(THF)]2 (μ-O) (5), whereas the addition of one equivalent of AgSbF6 to 1 resulted in oxidation to THF-solvated octahedral [PcCr(III) (THF)2 ]SbF6 (6). The reduction of 1 with three sequential equivalents of KEt3 BH resulted in the isolation of [K(DME)4 ][Pc(3-) Cr(II) ] (7), [K(DME)4 ]2 [Pc(4-) Cr(II) ] (8) and [K6 (DME)4 ][Pc(4-) Cr(I) ]2 (9), respectively. The reduced products are deep purple in colour, with visible absorption maxima between 500-580 nm. The ring-reduced complexes 7 and 8 are monomeric, whereas 9 is a 1D chain of dinuclear [PcCr]2 units with intercalated K(+) cations and supported by Cr-Cr interactions of 2.988(2) Å. Addition of four equivalents of KC8 resulted in the demetallated product PcK2 (DME)4 (10), which has a 1D chain structure. The isolation and structural characterization of new PcCr complexes spanning five oxidation states, including rare examples of crystalline reduced Pc-ring species emphasizes the broad redox activity and stability of phthalocyanine-based complexes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Persistence of acetochlor, atrazine, and S-metolachlor in surface and subsurface horizons of 2 typic argiudolls under no-tillage.

    Science.gov (United States)

    Bedmar, Francisco; Gimenez, Daniel; Costa, José Luis; Daniel, Peter E

    2017-11-01

    Variations in soil properties with depth strongly influence the degradation and persistence of herbicides, underlining the importance of studying these processes in soil horizons with distinctively different properties. The persistence of the herbicides acetochlor, atrazine, and S-metolachlor was measured in samples of the A, B, and C horizons of 2 Typic Argiudolls from Argentina under no-till management. The soils studied differed in soil organic carbon (OC) content, pH, particle size distribution, and structure. Quantification of herbicides in soil was done through high-performance liquid chromatography with diode array detector. There were interactions of herbicide × horizon (p < 0.01) that resulted in degradation rates (k) of all herbicides decreasing, and their corresponding dissipation half-life (DT50) values increasing, with soil depth. Herbicide persistence across all soils and horizons ranged from 15 to 73 d for acetochlor, 13 to 29 d for atrazine, and 82 to 141 d for S-metolachlor, which had significantly (p < 0.01) greater persistence than atrazine and acetochlor. The DT50 values of herbicides were negatively correlated with the contents of OC (correlation coefficients ranging from -0.496 to -0.773), phosphorus (-0.427 to -0.564), and nitrogen-nitrate (-0.507 to -0.662), and with microbial activity (-0.454 to -0.687) and the adsorption coefficient (-0.530 to -0.595); DT50s were positively correlated with pH (0.366 to 0.648). Adsorption was likely the most influential process in determining persistence of these herbicides in surface and subsurface horizons. The present study can potentially improve the prediction of the fate of acetochlor, atrazine, and S-metolachlor in soils because it includes much needed information on the degradation of the herbicides in subsurface horizons. Environ Toxicol Chem 2017;36:3065-3073. © 2017 SETAC. © 2017 SETAC.

  9. Fast algal eco-toxicity assessment: Influence of light intensity and exposure time on Chlorella vulgaris inhibition by atrazine and DCMU.

    Science.gov (United States)

    Camuel, Alexandre; Guieysse, Benoit; Alcántara, Cynthia; Béchet, Quentin

    2017-06-01

    In order to develop a rapid assay suitable for algal eco-toxicity assessments under conditions representative of natural ecosystems, this study evaluated the short-term (Chlorella vulgaris was exposed to these herbicides under 'standard' low light intensity (as prescribed by OECD201 guideline), the 20min-EC50 values recorded via oxygen productivity (atrazine: 1.32±0.07μM; DCMU: 0.31±0.005μM) were similar the 96-h EC50 recorded via algal growth (atrazine: 0.56μM; DCMU: 0.41μM), and within the range of values reported in the literature. 20min-EC50 values increased by factors of 3.0 and 2.1 for atrazine and DCMU, respectively, when light intensity increased from 60 to 1400μmolm-2s-1 of photosynthetically active radiation, or PAR. Further investigation showed that exposure time significantly also impacted the sensitivity of C. vulgaris under high light intensity (>840μmolm-2s-1 as PAR) as the EC50 for atrazine and DCMU decreased by up to 6.2 and 2.1 folds, respectively, after 50min of exposure at a light irradiance of 1400μmolm-2s-1 as PAR. This decrease was particularly marked at high light intensities and low algae concentrations and is explained by the herbicide disruption of the electron transfer chain triggering photo-inhibition at high light intensities. Eco-toxicity assessments aiming to understand the potential impact of toxic compounds on natural ecosystems should therefore be performed over sufficient exposure times (>20min for C. vulgaris) and under light intensities relevant to these ecosystems. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Pyramid image codes

    Science.gov (United States)

    Watson, Andrew B.

    1990-01-01

    All vision systems, both human and machine, transform the spatial image into a coded representation. Particular codes may be optimized for efficiency or to extract useful image features. Researchers explored image codes based on primary visual cortex in man and other primates. Understanding these codes will advance the art in image coding, autonomous vision, and computational human factors. In cortex, imagery is coded by features that vary in size, orientation, and position. Researchers have devised a mathematical model of this transformation, called the Hexagonal oriented Orthogonal quadrature Pyramid (HOP). In a pyramid code, features are segregated by size into layers, with fewer features in the layers devoted to large features. Pyramid schemes provide scale invariance, and are useful for coarse-to-fine searching and for progressive transmission of images. The HOP Pyramid is novel in three respects: (1) it uses a hexagonal pixel lattice, (2) it uses oriented features, and (3) it accurately models most of the prominent aspects of primary visual cortex. The transform uses seven basic features (kernels), which may be regarded as three oriented edges, three oriented bars, and one non-oriented blob. Application of these kernels to non-overlapping seven-pixel neighborhoods yields six oriented, high-pass pyramid layers, and one low-pass (blob) layer.

  11. Report number codes

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, R.N. (ed.)

    1985-05-01

    This publication lists all report number codes processed by the Office of Scientific and Technical Information. The report codes are substantially based on the American National Standards Institute, Standard Technical Report Number (STRN)-Format and Creation Z39.23-1983. The Standard Technical Report Number (STRN) provides one of the primary methods of identifying a specific technical report. The STRN consists of two parts: The report code and the sequential number. The report code identifies the issuing organization, a specific program, or a type of document. The sequential number, which is assigned in sequence by each report issuing entity, is not included in this publication. Part I of this compilation is alphabetized by report codes followed by issuing installations. Part II lists the issuing organization followed by the assigned report code(s). In both Parts I and II, the names of issuing organizations appear for the most part in the form used at the time the reports were issued. However, for some of the more prolific installations which have had name changes, all entries have been merged under the current name.

  12. Biodegradation of {sup 14} C-atrazine under outdoor conditions; Biodegradacao de {sup 14} C-atrazina em condicoes semi controladas

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Brigida Pimentel Villar de

    1997-10-01

    Uniformly {sup 14} C-ring labeled atrazine (5 L/ha) was applied to a Typical Hapludox Brazilian Soil sample which was incubated under outdoor conditions. Sample of 200 g (dry weight base) of fresh soil were distributed in Erlenmeyer flasks and the moisture was adjusted for 2/3 rds of the soil field capacity. The flasks were then buried in the Lysimeter Station when they were incubated. The experiment started jointly with a corn planting. The {sup 14} C O{sub 2} was analyzed every 15 day, during a period of 150 days. The desorbed, extracted and bound residues were analyzed. The extracted soil was fractionated and the residues in the humin, fulvic and humic acids were determined. At the end of the incubation period (150 days), the {sup 14} CO{sub 2} evolved reached up to 36% of the total applied activity, the bound residues were detected in about the same (34%) during the inoculation period, and were distributed in the fractions of fulvic acids (29,91%), humic acids (6,83%) and humin (63,26%). The metabolites formed in the desorbed residues and in the extracted residues were determined using thin layer chromatography with {sup 14} C-detector. After 150 days incubation, desorbed soil residues were identified as atrazine (52,72%), hydroxiatrazine (44%) and desisopropilatrazine (3,28%). The extractable residues contained atrazine (79,29%), hydroxiatrazine (16,22%), desisopropilatrazine (2,25%) and desetylatrazine (2,24%). (author)

  13. Rapid selective accelerated solvent extraction and simultaneous determination of herbicide atrazine and its metabolites in fruit by ultra high performance liquid chromatography.

    Science.gov (United States)

    Jia, Licong; Su, Ming; Wu, Xingqiang; Sun, Hanwen

    2016-12-01

    A selective accelerated solvent extraction procedure achieved one step extraction and cleanup for analysis of herbicide atrazine and its metabolites in fruit. Using a BEH C18 analytical column and the gradient mode with 2 mM ammonium acetate aqueous solution/acetonitrile as a mobile phase achieved effective chromatographic separation of the five analytes within 4 min. The calibration curves were linear over two orders of magnitude of concentration with correlation coefficients (r) of 0.9996-0.9999. The method limit of quantification was 1, 2, 1.5, 3, and 2 μg/kg for atrazine, desethylatrazine, desisopropylatrazine, desethyldesisopropylatrazine, and hydroxyatrazine, respectively, in the case of atrazine it is at least two orders of magnitude lower than the maximum residue limit (0.25 mg/kg). The intra-day and inter-day precisions of the five analytes were in the range of 2.1-3.5 and 3.1-4.8 %, respectively. The recoveries of the five analytes at three spiked levels varied from 85.9 to 107% with a relative standard deviation of 1.8-4.9% for pear and apple samples. The ultra high performance liquid chromatography with diode array detection method was proved to be fast, inexpensive, selective, sensitive, and accurate for the quantification of the analytes in pear and apple samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Monod kinetics rather than a first-order degradation model explains atrazine fate in soil mini-columns: Implications for pesticide fate modelling

    Energy Technology Data Exchange (ETDEWEB)

    Cheyns, K., E-mail: Karlien.Cheyns@ees.kuleuven.b [Division soil and water management, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee (Belgium); Mertens, J.; Diels, J.; Smolders, E.; Springael, D. [Division soil and water management, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee (Belgium)

    2010-05-15

    Pesticide transport models commonly assume first-order pesticide degradation kinetics for describing reactive transport in soil. This assumption was assessed in mini-column studies with associated batch degradation tests. Soil mini-columns were irrigated with atrazine in two intermittent steps of about 30 days separated by 161 days application of artificial rain water. Atrazine concentration in the effluent peaked to that of the influent concentration after initial break-through but sharply decreased while influx was sustained, suggesting a degradation lag phase. The same pattern was displayed in the second step but peak height and percentage of atrazine recovered in the effluent were lower. A Monod model with biomass decay was successfully calibrated to this data. The model was successfully evaluated against batch degradation data and mini-column experiments at lower flow rate. The study suggested that first-order degradation models may underestimate risk of pesticide leaching if the pesticide degradation potential needs amplification during degradation. - Population dynamics of pesticide degrading population should be taken into account when predictions of pesticide fate are made to avoid underestimation of pesticide break-through towards groundwater.

  15. Monod kinetics rather than a first-order degradation model explains atrazine fate in soil mini-columns: implications for pesticide fate modelling.

    Science.gov (United States)

    Cheyns, K; Mertens, J; Diels, J; Smolders, E; Springael, D

    2010-05-01

    Pesticide transport models commonly assume first-order pesticide degradation kinetics for describing reactive transport in soil. This assumption was assessed in mini-column studies with associated batch degradation tests. Soil mini-columns were irrigated with atrazine in two intermittent steps of about 30 days separated by 161 days application of artificial rain water. Atrazine concentration in the effluent peaked to that of the influent concentration after initial break-through but sharply decreased while influx was sustained, suggesting a degradation lag phase. The same pattern was displayed in the second step but peak height and percentage of atrazine recovered in the effluent were lower. A Monod model with biomass decay was successfully calibrated to this data. The model was successfully evaluated against batch degradation data and mini-column experiments at lower flow rate. The study suggested that first-order degradation models may underestimate risk of pesticide leaching if the pesticide degradation potential needs amplification during degradation. Copyright 2010 Elsevier Ltd. All rights reserved.

  16. CLIPS 6.0 - C LANGUAGE INTEGRATED PRODUCTION SYSTEM, VERSION 6.0 (IBM PC VERSION)

    Science.gov (United States)

    Donnell, B.

    1994-01-01

    COOL (that is, a rule can pattern match on objects created using COOL). CLIPS 6.0 provides the capability to define functions, overloaded functions, and global variables interactively. In addition, CLIPS can be embedded within procedural code, called as a subroutine, and integrated with languages such as C, FORTRAN and Ada. CLIPS can be easily extended by a user through the use of several well-defined protocols. CLIPS provides several delivery options for programs including the ability to generate stand alone executables or to load programs from text or binary files. CLIPS 6.0 provides support for the modular development and execution of knowledge bases with the defmodule construct. CLIPS modules allow a set of constructs to be grouped together such that explicit control can be maintained over restricting the access of the constructs by other modules. This type of control is similar to global and local scoping used in languages such as C or Ada. By restricting access to deftemplate and defclass constructs, modules can function as blackboards, permitting only certain facts and instances to be seen by other modules. Modules are also used by rules to provide execution control. The CRSV (Cross-Reference, Style, and Verification) utility included with previous version of CLIPS is no longer supported. The capabilities provided by this tool are now available directly within CLIPS 6.0 to aid in the development, debugging, and verification of large rule bases. COSMIC offers four distribution versions of CLIPS 6.0: UNIX (MSC-22433), VMS (MSC-22434), MACINTOSH (MSC-22429), and IBM PC (MSC-22430). Executable files, source code, utilities, documentation, and examples are included on the program media. All distribution versions include identical source code for the command line version of CLIPS 6.0. This source code should compile on any platform with an ANSI C compiler. Each distribution version of CLIPS 6.0, except that for the Macintosh platform, includes an executable for the

  17. Cryptography cracking codes

    CERN Document Server

    2014-01-01

    While cracking a code might seem like something few of us would encounter in our daily lives, it is actually far more prevalent than we may realize. Anyone who has had personal information taken because of a hacked email account can understand the need for cryptography and the importance of encryption-essentially the need to code information to keep it safe. This detailed volume examines the logic and science behind various ciphers, their real world uses, how codes can be broken, and the use of technology in this oft-overlooked field.

  18. Quantum coding theorems

    Science.gov (United States)

    Holevo, A. S.

    1998-12-01

    ContentsI. IntroductionII. General considerations § 1. Quantum communication channel § 2. Entropy bound and channel capacity § 3. Formulation of the quantum coding theorem. Weak conversionIII. Proof of the direct statement of the coding theorem § 1. Channels with pure signal states § 2. Reliability function § 3. Quantum binary channel § 4. Case of arbitrary states with bounded entropyIV. c-q channels with input constraints § 1. Coding theorem § 2. Gauss channel with one degree of freedom § 3. Classical signal on quantum background noise Bibliography

  19. Summary of product characteristics (SmPC)--study on utilization of information presented in SmPC by different groups of physicians.

    Science.gov (United States)

    Dzioba, Łukasz; Stańczak, Andrzej

    2012-01-01

    Cross-sectional survey study was done, investigating whether information included in SmPC (changing often due to safety reasons) is actually used, properly used or not used at all by cardiologists, GP's (general practitioners), internists and internal diseases physicians. Conducting readability test of Patient Information Leaflet, required by European Commission improved utilization of medical information included in it by European patients. Since there was no such requirement on Summary of Product Characteristics (SmPC), we examined utilization of information presented in Summary of Product Characteristics by physicians. Investigated were six drugs used in antiplatelet therapies, ATC (Anatomical, Therapeutic Chemical classification system) code B01AC. A random sample of 800 physicians took part in the study. They were physicians (300 cardiologists and 300 GP's) chosen from The Polish Chamber of Physicians and Dentists (PCPD) database interviewed using regular mail and 200 physicians interrogated during the XV International Congress of Polish Cardiac Society.Physicians. They were asked to complete a questionnaire consisting of 20 questions (13 concerning active substances, 6 general questions and one open question "Indicate the best way of receiving safety information"). Questions were constructed on the basis on new safety information included in actualized SmPC after submission of Periodic Safety Update Reports (PSURs) for medicinal products concerned. The overall response rate was 16.5% (132 filled in of 800 questionnaires). Of the respondents there were 65 and 67 from group I (cardiologists) and group II (GP's, internists and internal diseases), respectively. Eligible questionnaires (85) were obtained during the Congress (64.4%). Only 47 were received via regular mail (35.6%). Most correct answers were noted for clopidogrel and ASA (acetylsalicylic acid). 72.98% and 72.73%, respectively. The less known substance appeared eptifibatide, only 34.47% of answers

  20. METHANE de-NOX for Utility PC Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Bruce Bryan; Serguei Nester; Joseph Rabovitser; Stan Wohadlo

    2005-09-30

    The overall project objective is the development and validation of an innovative combustion system, based on a novel coal preheating concept prior to combustion, that can reduce NO{sub x} emissions to 0.15 lb/million Btu or less on utility pulverized coal (PC) boilers. This NO{sub x} reduction should be achieved without loss of boiler efficiency or operating stability, and at more than 25% lower levelized cost than state-of-the-art SCR technology. A further objective is to ready technology for full-scale commercial deployment to meet the market demand for NO{sub x} reduction technologies. Over half of the electric power generated in the U.S. is produced by coal combustion, and more than 80% of these units utilize PC combustion technology. Conventional measures for NOx reduction in PC combustion processes rely on combustion and post-combustion modifications. A variety of combustion-based NO{sub x} reduction technologies are in use today, including low-NO{sub x} burners (LNBs), flue gas recirculation (FGR), air staging, and natural gas or other fuel reburning. Selective non-catalytic reduction (SNCR) and selective catalytic reduction (SCR) are post-combustion techniques. NO{sub x} reduction effectiveness from these technologies ranges from 30 to 60% and up to 90-93% for SCR. Typically, older wall-fired PC burner units produce NO{sub x} emissions in the range of 0.8-1.6 lb/million Btu. Low-NO{sub x} burner systems, using combinations of fuel staging within the burner and air staging by introduction of overfire air in the boiler, can reduce NO{sub x} emissions by 50-60%. This approach alone is not sufficient to meet the desired 0.15 lb/million Btu NO{sub x} standard with a range of coals and boiler loads. Furthermore, the heavy reliance on overfire air can lead to increased slagging and corrosion in furnaces, particularly with higher-sulfur coals, when LNBs are operated at sub-stoichiometric conditions to reduce fuel-derived NOx in the flame. Therefore, it is desirable

  1. CARES/PC - CERAMICS ANALYSIS AND RELIABILITY EVALUATION OF STRUCTURES

    Science.gov (United States)

    Szatmary, S. A.

    1994-01-01

    The beneficial properties of structural ceramics include their high-temperature strength, light weight, hardness, and corrosion and oxidation resistance. For advanced heat engines, ceramics have demonstrated functional abilities at temperatures well beyond the operational limits of metals. This is offset by the fact that ceramic materials tend to be brittle. When a load is applied, their lack of significant plastic deformation causes the material to crack at microscopic flaws, destroying the component. CARES/PC performs statistical analysis of data obtained from the fracture of simple, uniaxial tensile or flexural specimens and estimates the Weibull and Batdorf material parameters from this data. CARES/PC is a subset of the program CARES (COSMIC program number LEW-15168) which calculates the fast-fracture reliability or failure probability of ceramic components utilizing the Batdorf and Weibull models to describe the effects of multi-axial stress states on material strength. CARES additionally requires that the ceramic structure be modeled by a finite element program such as MSC/NASTRAN or ANSYS. The more limited CARES/PC does not perform fast-fracture reliability estimation of components. CARES/PC estimates ceramic material properties from uniaxial tensile or from three- and four-point bend bar data. In general, the parameters are obtained from the fracture stresses of many specimens (30 or more are recommended) whose geometry and loading configurations are held constant. Parameter estimation can be performed for single or multiple failure modes by using the least-squares analysis or the maximum likelihood method. Kolmogorov-Smirnov and Anderson-Darling goodness-of-fit tests measure the accuracy of the hypothesis that the fracture data comes from a population with a distribution specified by the estimated Weibull parameters. Ninety-percent confidence intervals on the Weibull parameters and the unbiased value of the shape parameter for complete samples are provided

  2. Fulcrum Network Codes

    DEFF Research Database (Denmark)

    2015-01-01

    Fulcrum network codes, which are a network coding framework, achieve three objectives: (i) to reduce the overhead per coded packet to almost 1 bit per source packet; (ii) to operate the network using only low field size operations at intermediate nodes, dramatically reducing complexity...... in the network; and (iii) to deliver an end-to-end performance that is close to that of a high field size network coding system for high-end receivers while simultaneously catering to low-end ones that can only decode in a lower field size. Sources may encode using a high field size expansion to increase...... the number of dimensions seen by the network using a linear mapping. Receivers can tradeoff computational effort with network delay, decoding in the high field size, the low field size, or a combination thereof....

  3. VT ZIP Code Areas

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) A ZIP Code Tabulation Area (ZCTA) is a statistical geographic entity that approximates the delivery area for a U.S. Postal Service five-digit...

  4. Bandwidth efficient coding

    CERN Document Server

    Anderson, John B

    2017-01-01

    Bandwidth Efficient Coding addresses the major challenge in communication engineering today: how to communicate more bits of information in the same radio spectrum. Energy and bandwidth are needed to transmit bits, and bandwidth affects capacity the most. Methods have been developed that are ten times as energy efficient at a given bandwidth consumption as simple methods. These employ signals with very complex patterns and are called "coding" solutions. The book begins with classical theory before introducing new techniques that combine older methods of error correction coding and radio transmission in order to create narrowband methods that are as efficient in both spectrum and energy as nature allows. Other topics covered include modulation techniques such as CPM, coded QAM and pulse design.

  5. OCA Code Enforcement

    Data.gov (United States)

    Montgomery County of Maryland — The Office of the County Attorney (OCA) processes Code Violation Citations issued by County agencies. The citations can be viewed by issued department, issued date...

  6. Coded Random Access

    DEFF Research Database (Denmark)

    Paolini, Enrico; Stefanovic, Cedomir; Liva, Gianluigi

    2015-01-01

    , in which the structure of the access protocol can be mapped to a structure of an erasure-correcting code defined on graph. This opens the possibility to use coding theory and tools for designing efficient random access protocols, offering markedly better performance than ALOHA. Several instances of coded......The rise of machine-to-machine communications has rekindled the interest in random access protocols as a support for a massive number of uncoordinatedly transmitting devices. The legacy ALOHA approach is developed under a collision model, where slots containing collided packets are considered...... as waste. However, if the common receiver (e.g., base station) is capable to store the collision slots and use them in a transmission recovery process based on successive interference cancellation, the design space for access protocols is radically expanded. We present the paradigm of coded random access...

  7. Code Disentanglement: Initial Plan

    Energy Technology Data Exchange (ETDEWEB)

    Wohlbier, John Greaton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kelley, Timothy M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rockefeller, Gabriel M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Calef, Matthew Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-27

    The first step to making more ambitious changes in the EAP code base is to disentangle the code into a set of independent, levelized packages. We define a package as a collection of code, most often across a set of files, that provides a defined set of functionality; a package a) can be built and tested as an entity and b) fits within an overall levelization design. Each package contributes one or more libraries, or an application that uses the other libraries. A package set is levelized if the relationships between packages form a directed, acyclic graph and each package uses only packages at lower levels of the diagram (in Fortran this relationship is often describable by the use relationship between modules). Independent packages permit independent- and therefore parallel|development. The packages form separable units for the purposes of development and testing. This is a proven path for enabling finer-grained changes to a complex code.

  8. The fast code

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, L.N.; Wilson, R.E. [Oregon State Univ., Dept. of Mechanical Engineering, Corvallis, OR (United States)

    1996-09-01

    The FAST Code which is capable of determining structural loads on a flexible, teetering, horizontal axis wind turbine is described and comparisons of calculated loads with test data are given at two wind speeds for the ESI-80. The FAST Code models a two-bladed HAWT with degrees of freedom for blade bending, teeter, drive train flexibility, yaw, and windwise and crosswind tower motion. The code allows blade dimensions, stiffnesses, and weights to differ and models tower shadow, wind shear, and turbulence. Additionally, dynamic stall is included as are delta-3 and an underslung rotor. Load comparisons are made with ESI-80 test data in the form of power spectral density, rainflow counting, occurrence histograms, and azimuth averaged bin plots. It is concluded that agreement between the FAST Code and test results is good. (au)

  9. Coded Splitting Tree Protocols

    DEFF Research Database (Denmark)

    Sørensen, Jesper Hemming; Stefanovic, Cedomir; Popovski, Petar

    2013-01-01

    This paper presents a novel approach to multiple access control called coded splitting tree protocol. The approach builds on the known tree splitting protocols, code structure and successive interference cancellation (SIC). Several instances of the tree splitting protocol are initiated, each...... as possible. Evaluations show that the proposed protocol provides considerable gains over the standard tree splitting protocol applying SIC. The improvement comes at the expense of an increased feedback and receiver complexity....

  10. Code de conduite

    International Development Research Centre (IDRC) Digital Library (Canada)

    irocca

    son point de vue, dans un esprit d'accueil et de respect. NOTRE CODE DE CONDUITE. Le CRDI s'engage à adopter un comportement conforme aux normes d'éthique les plus strictes dans toutes ses activités. Le Code de conduite reflète notre mission, notre philosophie en matière d'emploi et les résultats des discussions ...

  11. On alleviation of atrazine and imidacloprid contamination from single component aqueous systems using rice straw biochars: An Optimization Study

    Science.gov (United States)

    Mandal, Abhishek; Singh, Neera

    2017-04-01

    Contamination of surface and ground water by pesticides from agricultural runoff and industrial discharge is one of the main causes of aqueous contaminations world over. Adsorption of pesticide on adsorbents is considered as the most feasible approach of decontamination. Biochar, agricultural waste derived highly aromatic substance produced after pyrolysis and carbonification of biomass have exhibited good adsorption capacity for pesticides and can be used to develop on-site bio-purification systems for organic contaminant removal from polluted waters. Normal (RSBC) and phosphoric acid treated (T-RSBC) rice straw biochars were characterized for their physico-chemical properties. The yield parameters of biochar suggested higher biomass-biochar conversion ratio for the rice biochar. T-RSBC (pH=6.93) was neutral whereas RSBC was alkaline in nature. The cation exchange capacity (CEC) of the biochars were quite high. Elemental analysis (C, H, N, O) of biochars suggested a higher total carbon content (47.7-49.5%) and degree of aromaticity (H/C 0.62-0.63) indicating increased stability of biochars than the parent feedstocks. Polarity increased when T-RSBC (O/C 0.416) was synthesized from RSBC (O/C 0.410). The surface area, pore volume and micropore volume of the biochars, calculated using BET N2 adsorption method, suggested that RSBC was the most porous biochar (220.2 m2 g-1) amongst the two studied. IR, SEM and XRD analysis of biochars suggested the presence of inorganic minerals, carbonates, aromatic moieties and carboxylic groups. Zeta potential measurement indicated that biochars' surfaces carried negative charges while Boehm titration results suggested abundant presence of surface acidic functional groups on both the biochars. Fairly good atrazine and imidacloprid removal were shown by RSBC (KFads,Atrz = 1363; KFads,Imida =1706) and T-RSBC (KFads,Atrz=2716; KFads,Imida= 3140). Results obtained by fitting the atrazine and imidacloprid adsorption data to the Freundlich

  12. Open Coding Descriptions

    Directory of Open Access Journals (Sweden)

    Barney G. Glaser, PhD, Hon PhD

    2016-12-01

    Full Text Available Open coding is a big source of descriptions that must be managed and controlled when doing GT research. The goal of generating a GT is to generate an emergent set of concepts and their properties that fit and work with relevancy to be integrated into a theory. To achieve this goal, the researcher begins his research with open coding, that is coding all his data in every possible way. The consequence of this open coding is a multitude of descriptions for possible concepts that often do not fit in the emerging theory. Thus in this case the researcher ends up with many irrelevant descriptions for concepts that do not apply. To dwell on descriptions for inapplicable concepts ruins the GT theory as it starts. It is hard to stop. Confusion easily sets in. Switching the study to a QDA is a simple rescue. Rigorous focusing on emerging concepts is vital before being lost in open coding descriptions. It is important, no matter how interesting the description may become. Once a core is possible, selective coding can start which will help control against being lost in multiple descriptions.

  13. Estimation of placental and lactational transfer and tissue distribution of atrazine and its main metabolites in rodent dams, fetuses, and neonates with physiologically based pharmacokinetic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Zhoumeng [Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (United States); Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602 (United States); Fisher, Jeffrey W. [Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079 (United States); Wang, Ran [Center for Environmental Health Sciences, Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762 (United States); Institute of Food Safety, Jiangsu Academy of Agricultural Sciences, Nanjing 210014 (China); Ross, Matthew K. [Center for Environmental Health Sciences, Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762 (United States); Filipov, Nikolay M., E-mail: filipov@uga.edu [Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (United States); Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602 (United States)

    2013-11-15

    Atrazine (ATR) is a widely used chlorotriazine herbicide, a ubiquitous environmental contaminant, and a potential developmental toxicant. To quantitatively evaluate placental/lactational transfer and fetal/neonatal tissue dosimetry of ATR and its major metabolites, physiologically based pharmacokinetic models were developed for rat dams, fetuses and neonates. These models were calibrated using pharmacokinetic data from rat dams repeatedly exposed (oral gavage; 5 mg/kg) to ATR followed by model evaluation against other available rat data. Model simulations corresponded well to the majority of available experimental data and suggest that: (1) the fetus is exposed to both ATR and its major metabolite didealkylatrazine (DACT) at levels similar to maternal plasma levels, (2) the neonate is exposed mostly to DACT at levels two-thirds lower than maternal plasma or fetal levels, while lactational exposure to ATR is minimal, and (3) gestational carryover of DACT greatly affects its neonatal dosimetry up until mid-lactation. To test the model's cross-species extrapolation capability, a pharmacokinetic study was conducted with pregnant C57BL/6 mice exposed (oral gavage; 5 mg/kg) to ATR from gestational day 12 to 18. By using mouse-specific parameters, the model predictions fitted well with the measured data, including placental ATR/DACT levels. However, fetal concentrations of DACT were overestimated by the model (10-fold). This overestimation suggests that only around 10% of the DACT that reaches the fetus is tissue-bound. These rodent models could be used in fetal/neonatal tissue dosimetry predictions to help design/interpret early life toxicity/pharmacokinetic studies with ATR and as a foundation for scaling to humans. - Highlights: • We developed PBPK models for atrazine in rat dams, fetuses, and neonates. • We conducted pharmacokinetic (PK) study with atrazine in pregnant mice. • Model predictions were in good agreement with experimental rat and mouse PK data

  14. Tablet PC Enabled Body Sensor System for Rural Telehealth Applications

    Directory of Open Access Journals (Sweden)

    Nitha V. Panicker

    2016-01-01

    Full Text Available Telehealth systems benefit from the rapid growth of mobile communication technology for measuring physiological signals. Development and validation of a tablet PC enabled noninvasive body sensor system for rural telehealth application are discussed in this paper. This system includes real time continuous collection of physiological parameters (blood pressure, pulse rate, and temperature and fall detection of a patient with the help of a body sensor unit and wireless transmission of the acquired information to a tablet PC handled by the medical staff in a Primary Health Center (PHC. Abnormal conditions are automatically identified and alert messages are given to the medical officer in real time. Clinical validation is performed in a real environment and found to be successful. Bland-Altman analysis is carried out to validate the wrist blood pressure sensor used. The system works well for all measurements.

  15. Performance Evaluation of a Multipurpose Bare PC Gateway

    DEFF Research Database (Denmark)

    Tsetse, Anthony; Appiah-Kubi, Patrick; Loukili, Alae

    2015-01-01

    . Different solutions (6to4 tunneling, IVI translation, NAT64, DNS64 etc.), have being proposed but these are all standalone systems. In this paper we discuss the design,implementation and performance evaluation of a multipurpose Bare PC Gateway which incorporates Network Address translation (NAT), 6to4...... tunneling and IVI translation in a single “box” using Bare Machine Computing Paradigm. Experimental testing of the designed system shows our single point integrated system performs well using various measurement metrics as throughput, response time, connection time, jitter etc. in a LAN environment. Our...... results indicate a relatively better performance (18%-45%) of the Bare PC gateway compared to a Linux gateway (running the functionalities as standalone systems). We believe the proposed solution could easily scale to wide area networks and also provide a cost efficient solution...

  16. Flexible missile autopilot design studies with PC-MATLAB/386

    Science.gov (United States)

    Ruth, Michael J.

    1989-01-01

    Development of a responsive, high-bandwidth missile autopilot for airframes which have structural modes of unusually low frequency presents a challenging design task. Such systems are viable candidates for modern, state-space control design methods. The PC-MATLAB interactive software package provides an environment well-suited to the development of candidate linear control laws for flexible missile autopilots. The strengths of MATLAB include: (1) exceptionally high speed (MATLAB's version for 80386-based PC's offers benchmarks approaching minicomputer and mainframe performance); (2) ability to handle large design models of several hundred degrees of freedom, if necessary; and (3) broad extensibility through user-defined functions. To characterize MATLAB capabilities, a simplified design example is presented. This involves interactive definition of an observer-based state-space compensator for a flexible missile autopilot design task. MATLAB capabilities and limitations, in the context of this design task, are then summarized.

  17. PC analysis of stochastic differential equations driven by Wiener noise

    KAUST Repository

    Le Maitre, Olivier

    2015-03-01

    A polynomial chaos (PC) analysis with stochastic expansion coefficients is proposed for stochastic differential equations driven by additive or multiplicative Wiener noise. It is shown that for this setting, a Galerkin formalism naturally leads to the definition of a hierarchy of stochastic differential equations governing the evolution of the PC modes. Under the mild assumption that the Wiener and uncertain parameters can be treated as independent random variables, it is also shown that the Galerkin formalism naturally separates parametric uncertainty and stochastic forcing dependences. This enables us to perform an orthogonal decomposition of the process variance, and consequently identify contributions arising from the uncertainty in parameters, the stochastic forcing, and a coupled term. Insight gained from this decomposition is illustrated in light of implementation to simplified linear and non-linear problems; the case of a stochastic bifurcation is also considered.

  18. Metal Detector By Using PIC Microcontroller Interfacing With PC

    Directory of Open Access Journals (Sweden)

    Yin Min Theint

    2015-06-01

    Full Text Available Abstract This system proposes metal detector by using PIC microcontroller interfacing with PC. The system uses PIC microcontroller as the main controller whether the detected metal is ferrous metal or non-ferrous metal. Among various types of metal sensors and various types of metal detecting technologies concentric type induction coil sensor and VLF very low frequency metal detecting technology are used in this system. This system consists of two configurations Hardware configuration and Software configuration. The hardware components include induction coil sensors which senses the frequency changes of metal a PIC microcontroller personal computer PC buzzer light emitting diode LED and webcam. The software configuration includes a program controller interface. PIC MikroCprogramming language is used to implement the control system. This control system is based on the PIC 16F887 microcontroller.This system is mainly used in mining and high security places such as airport plaza shopping mall and governmental buildings.

  19. Pocket PC-based portable gamma-ray spectrometer

    Directory of Open Access Journals (Sweden)

    Kamontip Ploykrachang

    2011-04-01

    Full Text Available A portable gamma-ray spectrometer based on a Pocket PC has been developed. A 12-bit pipeline analog-to-digitalconverter (ADC associated with an implemented pulse height histogram function on field programmable gate array (FPGAoperating at 15 MHz is employed for pulse height analysis from built-in pulse amplifier. The system, which interfaces withthe Pocket PC via an enhanced RS-232 serial port under the microcontroller facilitation, is utilized for spectrum acquisition,display and analysis. The pulse height analysis capability of the system was tested and it was found that the ADC integralnonlinearity of ±0.45% was obtained with the throughput rate at 160 kcps. The overall system performance was tested usinga PIN photodiode-CsI(Tl crystal coupled scintillation detector and gamma standard radioactive sources of Cs-137 andCo-60. Low cost and the compact system size as a result of the implemented logical function are also discussed.

  20. DIFFERENTIAL MODULATION OF CATECHOLAMINES BY CHLOROTRIAZINE HERBICIDES IN PHEOCHROMOCYTOMA (PC12) CELLS IN VITRO

    Science.gov (United States)

    Differential modulation of catecholamines by chlorotriazine herbicides in pheochromocytoma (PC12) cells in vitro.Das PC, McElroy WK, Cooper RL.Curriculum in Toxicology, University of North Carolina, Chapel Hill 27599, USA.Epidemiological, wildlife, and lab...

  1. Efficient Techniques for Formal Verification of PowerPC 750 Executables Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We will develop an efficient tool for formal verification of PowerPC 750 executables. The PowerPC 750 architecture is used in the radiation-hardened RAD750...

  2. Development of educational PC software for visually impaired children

    OpenAIRE

    Holá, Klára

    2010-01-01

    The diploma work is focused on development of educational PC software dedicated to visually impaired children. It is intended for junior school-aged children with visual abilities in category of middle and high level of low vision and also for children with disorders of binocular vision. The intention of this sotware is education of visually impaired children especially in domain of knowledge about the world of animals. It also helps children to reeducate their vision abilities.

  3. MicroPCPC: A comprehensive resource for predicting and comparing plant microRNAs

    Directory of Open Access Journals (Sweden)

    Wichadakul Duangdao

    2009-08-01

    Full Text Available Abstract Background Plant microRNA (miRNA has an important role in controlling gene regulation in various biological processes such as cell development, signal transduction, and environmental responses. While information on plant miRNAs and their targets is widely available, accessible online plant miRNA resources are limited; most of them are intended for economically important crops or plant model organisms. With abundant sequence data of numerous plants in public databases such as NCBI and PlantGDB, the identification of their miRNAs and targets would benefit researchers as a central resource for the comparative studies of plant miRNAs. Results MicroPCPC is an online plant miRNA resource resulted from large-scale Expressed Sequence Tag (EST analysis. It consists of 4,006 potential miRNA candidates in 128 families of 125 plant species and 2,995 proteins (4,953 EST sequences potentially targeted by 78 families of miRNA candidates. In addition, it is incorporated with 1,727 previously reported plant mature miRNA sequences from miRBase. The μPC enables users to compare stored mature or precursor miRNAs and user-supplied sequences among plant species. The search utility allows users to investigate the predicted miRNAs and miRNA targets in detail via various search options such as miRNA family and plant species. To enhance the database usage, the prediction utility provides interactive steps for determining a miRNA or miRNA targets from an input nucleotide sequence and links the prediction results to their homologs in the μPC. Conclusion The μPC constitutes the first online resource that enables users to comprehensively compare and predict plant miRNAs and their targets. It imparts a basis for further research on revealing miRNA conservation, function, and evolution across plant species and classification. The μPC is available at http://www.biotec.or.th/isl/micropc.

  4. HUDU: The Hanford Unified Dose Utility computer code

    Energy Technology Data Exchange (ETDEWEB)

    Scherpelz, R.I.

    1991-02-01

    The Hanford Unified Dose Utility (HUDU) computer program was developed to provide rapid initial assessment of radiological emergency situations. The HUDU code uses a straight-line Gaussian atmospheric dispersion model to estimate the transport of radionuclides released from an accident site. For dose points on the plume centerline, it calculates internal doses due to inhalation and external doses due to exposure to the plume. The program incorporates a number of features unique to the Hanford Site (operated by the US Department of Energy), including a library of source terms derived from various facilities' safety analysis reports. The HUDU code was designed to run on an IBM-PC or compatible personal computer. The user interface was designed for fast and easy operation with minimal user training. The theoretical basis and mathematical models used in the HUDU computer code are described, as are the computer code itself and the data libraries used. Detailed instructions for operating the code are also included. Appendices to the report contain descriptions of the program modules, listings of HUDU's data library, and descriptions of the verification tests that were run as part of the code development. 14 refs., 19 figs., 2 tabs.

  5. Virtual reality exposure therapy: 150-degree screen to desktop PC.

    Science.gov (United States)

    Tichon, Jennifer; Banks, Jasmine

    2006-08-01

    Virtual reality exposure therapy (VRET) developed using immersive or semi-immersive virtual environments present a usability problem for practitioners. To meet practitioner requirements for lower cost and portability VRET programs must often be ported onto desktop environments such as the personal computer (PC). However, success of VRET has been shown to be linked to presence, and the environment's ability to evoke the same reactions and emotions as a real experience. It is generally accepted that high-end virtual environments (VEs) are more immersive than desktop PCs, but level of immersion does not always predict level of presence. This paper reports on the impact on presence of porting a therapeutic VR application for schizophrenia from the initial research environment of a semi-immersive curved screen to PC. Presence in these two environments is measured both introspectively and across a number of causal factors thought to underlie the experience of presence. Results show that the VR exposure program successfully made users feel they were "present" in both platforms. While the desktop PC achieved higher scores on presence across causal factors participants reported they felt more present in the curved screen environment. While comparison of the two groups was statistically significant for the PQ but not for the IPQ, subjective reports of experiences in the environments should be considered in future research as the success of VRET relies heavily on the emotional response of patients to the therapeutic program.

  6. The 200-pc molecular cylinder in the Galactic Centre

    Science.gov (United States)

    Sofue, Yoshiaki

    2017-09-01

    Analysing the 3D structure of the molecular gas distribution in the central 200-pc region of the Galaxy, we show that the expanding molecular ring (EMR, also known as the parallelogram) and the central molecular zone (CMZ) exhibit quite different distributions and kinematics. The EMR composes a bipolar vertical cylinder with the total length as long as ˜170 pc and shows large non-circular velocities. On the contrary, the CMZ is distributed in a nearly rigid-body rotating ring and arms tightly concentrated near the galactic plane with full thickness less than ˜30 pc. Furthermore, the mass and density ratios of the EMR to CMZ are as small as ˜0.13 and 0.04, respectively. We discuss the origins of the EMR and CMZ based on the bar and explosion models. We suggest that the EMR's large vertical extent can be explained by a cylindrical shock wave model driven by an explosive activity in the Galactic Centre.

  7. Some new ternary linear codes

    Directory of Open Access Journals (Sweden)

    Rumen Daskalov

    2017-07-01

    Full Text Available Let an $[n,k,d]_q$ code be a linear code of length $n$, dimension $k$ and minimum Hamming distance $d$ over $GF(q$. One of the most important problems in coding theory is to construct codes with optimal minimum distances. In this paper 22 new ternary linear codes are presented. Two of them are optimal. All new codes improve the respective lower bounds in [11].

  8. File list: His.Lng.20.AllAg.PC-9 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Lng.20.AllAg.PC-9 hg19 Histone Lung PC-9 SRX815736,SRX815737,SRX815738,SRX12936...76,SRX815739,SRX1293674,SRX1293677,SRX1293675 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.Lng.20.AllAg.PC-9.bed ...

  9. File list: ALL.Lng.05.AllAg.PC-9 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Lng.05.AllAg.PC-9 hg19 All antigens Lung PC-9 SRX1293676,SRX815738,SRX815739,SR...X815737,SRX815736,SRX1293674,SRX1293677,SRX1293675 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Lng.05.AllAg.PC-9.bed ...

  10. Multi-satellite study of the excitation of Pc3 and Pc4-5 ULF waves and their penetration across the plasmapause during the 2003 Halloween superstorm

    Directory of Open Access Journals (Sweden)

    G. Balasis

    2015-10-01

    Full Text Available We use multi-satellite and ground-based magnetic data to investigate the concurrent characteristics of Pc3 (22–100 mHz and Pc4-5 (1–22 mHz ultra-low-frequency (ULF waves on the 31 October 2003 during the Halloween magnetic superstorm. ULF waves are seen in the Earth's magnetosphere, topside ionosphere, and Earth's surface, enabling an examination of their propagation characteristics. We employ a time–frequency analysis technique and examine data from when the Cluster and CHAMP spacecraft were in good local time (LT conjunction near the dayside noon–midnight meridian. We find clear evidence of the excitation of both Pc3 and Pc4-5 waves, but more significantly we find a clear separation in the L shell of occurrence of the Pc4-5 and Pc3 waves in the equatorial inner magnetosphere, separated by the density gradients at the plasmapause boundary layer. A key finding of the wavelet spectral analysis of data collected from the Geotail, Cluster, and CHAMP spacecraft and the CARISMA and GIMA magnetometer networks was a remarkably clear transition of the waves' frequency into dominance in a higher-frequency regime within the Pc3 range. Analysis of the local field line resonance frequency suggests that the separation of the Pc4-5 and Pc3 emissions across the plasmapause is consistent with the structure of the inhomogeneous field line resonance Alfvén continuum. The Pc4-5 waves are consistent with direct excitation by the solar wind in the plasma trough, as well as Pc3 wave absorption in the plasmasphere following excitation by upstream waves originating at the bow shock in the local noon sector. However, despite good solar wind coverage, our study was not able to unambiguously identify a clear explanation for the sharp universal time (UT onset of the discrete frequency and large-amplitude Pc3 wave power.

  11. Multi-satellite study of the excitation of Pc3 and Pc4-5 ULF waves and their penetration across the plasmapause during the 2003 Halloween superstorm

    Science.gov (United States)

    Balasis, G.; Daglis, I. A.; Mann, I. R.; Papadimitriou, C.; Zesta, E.; Georgiou, M.; Haagmans, R.; Tsinganos, K.

    2015-10-01

    We use multi-satellite and ground-based magnetic data to investigate the concurrent characteristics of Pc3 (22-100 mHz) and Pc4-5 (1-22 mHz) ultra-low-frequency (ULF) waves on the 31 October 2003 during the Halloween magnetic superstorm. ULF waves are seen in the Earth's magnetosphere, topside ionosphere, and Earth's surface, enabling an examination of their propagation characteristics. We employ a time-frequency analysis technique and examine data from when the Cluster and CHAMP spacecraft were in good local time (LT) conjunction near the dayside noon-midnight meridian. We find clear evidence of the excitation of both Pc3 and Pc4-5 waves, but more significantly we find a clear separation in the L shell of occurrence of the Pc4-5 and Pc3 waves in the equatorial inner magnetosphere, separated by the density gradients at the plasmapause boundary layer. A key finding of the wavelet spectral analysis of data collected from the Geotail, Cluster, and CHAMP spacecraft and the CARISMA and GIMA magnetometer networks was a remarkably clear transition of the waves' frequency into dominance in a higher-frequency regime within the Pc3 range. Analysis of the local field line resonance frequency suggests that the separation of the Pc4-5 and Pc3 emissions across the plasmapause is consistent with the structure of the inhomogeneous field line resonance Alfvén continuum. The Pc4-5 waves are consistent with direct excitation by the solar wind in the plasma trough, as well as Pc3 wave absorption in the plasmasphere following excitation by upstream waves originating at the bow shock in the local noon sector. However, despite good solar wind coverage, our study was not able to unambiguously identify a clear explanation for the sharp universal time (UT) onset of the discrete frequency and large-amplitude Pc3 wave power.

  12. Ellipsometric study of the optical transitions of PC{sub 60}BM and PC{sub 70}BM thin films

    Energy Technology Data Exchange (ETDEWEB)

    Bencheikh Aboura, Fatima, E-mail: fatima.bencheikh-aboura@im2np.fr; Duché, D.; Simon, J.J.; Escoubas, L.

    2015-04-01

    Highlights: • We determine the optical properties of two fullerene derivatives using ellipsometry. • Multisample analysis is applied to verify the uniqueness of the model. • The energy position of the oscillators used are compared with ones present in the parent molecules. - Abstract: Spectroscopic ellipsometry is used to determine the optical properties and to extract electronic transitions of PC{sub 60}BM and PC{sub 70}BM thin films in the UV–Visible range. By means of a sum of Gaussian oscillators, the imaginary parts of dielectric functions of both materials are modeled. The physical meaning of each model is checked by comparing the energy position of the oscillators with known optical transitions of the C{sub 60} and C{sub 70} molecules as revealed in literature by others techniques. It is shown that spectroscopic ellipsometry is a powerful technique to investigate the electronic structure of pi-conjugated molecules.

  13. Static and Dynamic Energetic Disorders in the C 60 , PC 61 BM, C 70 , and PC 71 BM Fullerenes

    KAUST Repository

    Tummala, Naga Rajesh

    2015-09-17

    We use a combination of molecular dynamics simulations and density functional theory calculations to investigate the energetic disorder in fullerene systems. We show that the energetic disorder evaluated from an ensemble average contains contributions of both static origin (time-independent, due to loose packing) and dynamic origin (time-dependent, due to electron-vibration interactions). In order to differentiate between these two contributions, we compare the results obtained from an ensemble average approach with those derived from a time average approach. It is found that in both amorphous C60 and C70 bulk systems, the degrees of static and dynamic disorder are comparable, while in the amorphous PC61BM and PC71BM systems, static disorder is about twice as large as dynamic disorder. © 2015 American Chemical Society.

  14. Code blue: seizures.

    Science.gov (United States)

    Hoerth, Matthew T; Drazkowski, Joseph F; Noe, Katherine H; Sirven, Joseph I

    2011-06-01

    Eyewitnesses frequently perceive seizures as life threatening. If an event occurs on the hospital premises, a "code blue" can be called which consumes considerable resources. The purpose of this study was to determine the frequency and characteristics of code blue calls for seizures and seizure mimickers. A retrospective review of a code blue log from 2001 through 2008 identified 50 seizure-like events, representing 5.3% of all codes. Twenty-eight (54%) occurred in inpatients; the other 22 (44%) events involved visitors or employees on the hospital premises. Eighty-six percent of the events were epileptic seizures. Seizure mimickers, particularly psychogenic nonepileptic seizures, were more common in the nonhospitalized group. Only five (17.9%) inpatients had a known diagnosis of epilepsy, compared with 17 (77.3%) of the nonhospitalized patients. This retrospective survey provides insights into how code blues are called on hospitalized versus nonhospitalized patients for seizure-like events. Copyright © 2011. Published by Elsevier Inc.

  15. Error coding simulations

    Science.gov (United States)

    Noble, Viveca K.

    1993-11-01

    There are various elements such as radio frequency interference (RFI) which may induce errors in data being transmitted via a satellite communication link. When a transmission is affected by interference or other error-causing elements, the transmitted data becomes indecipherable. It becomes necessary to implement techniques to recover from these disturbances. The objective of this research is to develop software which simulates error control circuits and evaluate the performance of these modules in various bit error rate environments. The results of the evaluation provide the engineer with information which helps determine the optimal error control scheme. The Consultative Committee for Space Data Systems (CCSDS) recommends the use of Reed-Solomon (RS) and convolutional encoders and Viterbi and RS decoders for error correction. The use of forward error correction techniques greatly reduces the received signal to noise needed for a certain desired bit error rate. The use of concatenated coding, e.g. inner convolutional code and outer RS code, provides even greater coding gain. The 16-bit cyclic redundancy check (CRC) code is recommended by CCSDS for error detection.

  16. Twisted Reed-Solomon Codes

    DEFF Research Database (Denmark)

    Beelen, Peter; Puchinger, Sven; Rosenkilde ne Nielsen, Johan

    2017-01-01

    We present a new general construction of MDS codes over a finite field Fq. We describe two explicit subclasses which contain new MDS codes of length at least q/2 for all values of q ≥ 11. Moreover, we show that most of the new codes are not equivalent to a Reed-Solomon code.......We present a new general construction of MDS codes over a finite field Fq. We describe two explicit subclasses which contain new MDS codes of length at least q/2 for all values of q ≥ 11. Moreover, we show that most of the new codes are not equivalent to a Reed-Solomon code....

  17. Optical coding theory with Prime

    CERN Document Server

    Kwong, Wing C

    2013-01-01

    Although several books cover the coding theory of wireless communications and the hardware technologies and coding techniques of optical CDMA, no book has been specifically dedicated to optical coding theory-until now. Written by renowned authorities in the field, Optical Coding Theory with Prime gathers together in one volume the fundamentals and developments of optical coding theory, with a focus on families of prime codes, supplemented with several families of non-prime codes. The book also explores potential applications to coding-based optical systems and networks. Learn How to Construct

  18. Manufacturer Identification Code (MID) - ACE

    Data.gov (United States)

    Department of Homeland Security — The ACE Manufacturer Identification Code (MID) application is used to track and control identifications codes for manufacturers. A manufacturer is identified on an...

  19. Algebraic and stochastic coding theory

    CERN Document Server

    Kythe, Dave K

    2012-01-01

    Using a simple yet rigorous approach, Algebraic and Stochastic Coding Theory makes the subject of coding theory easy to understand for readers with a thorough knowledge of digital arithmetic, Boolean and modern algebra, and probability theory. It explains the underlying principles of coding theory and offers a clear, detailed description of each code. More advanced readers will appreciate its coverage of recent developments in coding theory and stochastic processes. After a brief review of coding history and Boolean algebra, the book introduces linear codes, including Hamming and Golay codes.

  20. Speech coding code- excited linear prediction

    CERN Document Server

    Bäckström, Tom

    2017-01-01

    This book provides scientific understanding of the most central techniques used in speech coding both for advanced students as well as professionals with a background in speech audio and or digital signal processing. It provides a clear connection between the whys hows and whats thus enabling a clear view of the necessity purpose and solutions provided by various tools as well as their strengths and weaknesses in each respect Equivalently this book sheds light on the following perspectives for each technology presented Objective What do we want to achieve and especially why is this goal important Resource Information What information is available and how can it be useful and Resource Platform What kind of platforms are we working with and what are their capabilities restrictions This includes computational memory and acoustic properties and the transmission capacity of devices used. The book goes on to address Solutions Which solutions have been proposed and how can they be used to reach the stated goals and ...