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Sample records for parathion pc code

  1. Parathion

    Integrated Risk Information System (IRIS)

    Parathion ; CASRN 56 - 38 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects

  2. Spent fuel pin temperature PC code

    SciTech Connect

    Fischer, L.E.

    1985-03-01

    During an annual outage, a Pressurized Water Reactor (PWR) may discharge 60 or more spent fuel bundles into its storage pool. Most early PWRs were built to store 3 to 5 years of spent fuel in their pools and are beginning to exceed their capacities. One method currently being developed and licensed for expanding spent fuel storage capabilities is the dry storage of spent fuel in large casks. To reduce the probability of gross failures of fuel cladding during dry storage in casks, the fuel pin temperatures must be shown to remain within acceptable limits. LLNL has developed, for the Nuclear Regulatory Commission, a personal computer (PC) code for calculating fuel pin temperatures on the IBM PC. The code uses the Wooton-Epstein Correlation to calculate the pin temperatures and has been benchmarked against test data. An iterative type of solution is used to calculate the fuel pin temperatures for specified heat fluxes and pin configurations. The PC code is useful in performing confirmatory analyses and comparing the results with those submitted by applicants applying for storage licenses. 5 references, 2 tables.

  3. HOTSPOT Health Physics codes for the PC

    SciTech Connect

    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).

  4. Methyl parathion

    Integrated Risk Information System (IRIS)

    Methyl parathion ; CASRN 298 - 00 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  5. VENTURE/PC manual: A multidimensional multigroup neutron diffusion code system

    SciTech Connect

    Shapiro, A.; Huria, H.C.; Cho, K.W. )

    1991-12-01

    VENTURE/PC is a recompilation of part of the Oak Ridge BOLD VENTURE code system, which will operate on an IBM PC or compatible computer. Neutron diffusion theory solutions are obtained for multidimensional, multigroup problems. This manual contains information associated with operating the code system. The purpose of the various modules used in the code system, and the input for these modules are discussed. The PC code structure is also given. Version 2 included several enhancements not given in the original version of the code. In particular, flux iterations can be done in core rather than by reading and writing to disk, for problems which allow sufficient memory for such in-core iterations. This speeds up the iteration process. Version 3 does not include any of the special processors used in the previous versions. These special processors utilized formatted input for various elements of the code system. All such input data is now entered through the Input Processor, which produces standard interface files for the various modules in the code system. In addition, a Standard Interface File Handbook is included in the documentation which is distributed with the code, to assist in developing the input for the Input Processor.

  6. VENTURE/PC manual: A multidimensional multigroup neutron diffusion code system. Version 3

    SciTech Connect

    Shapiro, A.; Huria, H.C.; Cho, K.W.

    1991-12-01

    VENTURE/PC is a recompilation of part of the Oak Ridge BOLD VENTURE code system, which will operate on an IBM PC or compatible computer. Neutron diffusion theory solutions are obtained for multidimensional, multigroup problems. This manual contains information associated with operating the code system. The purpose of the various modules used in the code system, and the input for these modules are discussed. The PC code structure is also given. Version 2 included several enhancements not given in the original version of the code. In particular, flux iterations can be done in core rather than by reading and writing to disk, for problems which allow sufficient memory for such in-core iterations. This speeds up the iteration process. Version 3 does not include any of the special processors used in the previous versions. These special processors utilized formatted input for various elements of the code system. All such input data is now entered through the Input Processor, which produces standard interface files for the various modules in the code system. In addition, a Standard Interface File Handbook is included in the documentation which is distributed with the code, to assist in developing the input for the Input Processor.

  7. Propulsion stability codes for liquid propellant propulsion systems developed for use on a PC computer

    NASA Technical Reports Server (NTRS)

    Doane, George B., III; Armstrong, Wilbur C.

    1991-01-01

    Research into component modeling and system synthesis leading to the analysis of the major types of propulsion system instabilities and the characterization of various components characteristics are presented. Last year, several programs designed to run on a PC were developed for Marshall Space Flight Center. These codes covered the low, intermediate, and high frequency modes of oscillation of a liquid rocket propulsion system. No graphics were built into these programs and only simple piping layouts were supported. This year's effort was to add run time graphics to the low and intermediate frequency codes, allow new types of piping elements (accumulators, pumps, and split pipes) in the low frequency code, and develop a new code for the PC to generate Nyquist plots.

  8. PC-based PCM (Pulse Code Modulation) telemetry data reduction system hardware

    SciTech Connect

    Simms, D.A.; Butterfield, C.P.

    1990-02-01

    The Solar Energy Research Institute's (SERI) Wind Research Program is using pulse code modulation (PCM) telemetry systems to study horizontal-axis wind turbines. SERI has developed a low-cost PC-based PCM data acquisition system to facilitate quick PCM data analysis in the field. The SERI PC-PCM system consists of AT-compatible hardware boards for decoding and combining PCM data streams and DOS software for control and management of data acquisition. Up to four boards can be installed in a single PC, providing the capability to combine data from four PCM streams direct to disk or memory. This paper describes the SERI PC-PCM system hardware, focusing on the practicality of PC-based PCM data reduction. A related paper highlights our comprehensive PCM data management software program which can be used in conjunction with this hardware to provide full quick-look'' data processing and display. The PC-PCM hardware boards support a subset of the Inter-Range Instrumentation Group (IRIG) PCM standard, designed to synchronize and decommutate NRZ or Bi-Phase L PCM streams in the range of 1 to 800 Kbits/sec at 8 to 12 bits per word and 2 to 64 words per frame. Multiple PCM streams (at various rates) can be combined and interleaved into a contiguous digital time series. Maximum data throughput depends on characteristics of the PC hardware, such as CPU rate and disk access speed. 7 refs., 6 figs., 4 tabs.

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

    PubMed Central

    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

  10. Reductive transformation of parathion and methyl parathion by Bacillus sp.

    PubMed

    Yang, Chao; Dong, Ming; Yuan, Yulan; Huang, Yao; Guo, Xinmin; Qiao, Chuanling

    2007-03-01

    Based on the results of phenotypic features, phylogenetic similarity of 16S rRNA gene sequences and BIOLOG test, a soil bacterium was identified as Bacillus sp. DM-1. Using either growing cells or a cell-free extract, it transformed parathion and methyl parathion to amino derivatives by reducing the nitro group. Pesticide transformation by a cell-free extract was specifically inhibited by three nitroreductase inhibitors, indicating the presence of nitroreductase activity. The nitroreductase activity was NAD(P)H-dependent, O(2)-insensitive, and exhibited the substrate specificity for parathion and methyl parathion. Reductive transformation significantly decreased the toxicity of pesticides.

  11. NUSTART: A PC code for NUclear STructure And Radiative Transition analysis and supplementation

    SciTech Connect

    Larsen, G.L.; Gardner, D.G.; Gardner, M.A.

    1990-10-01

    NUSTART is a computer program for the IBM PC/At. It is designed for use with the nuclear reaction cross-section code STAPLUS, which is a STAPRE-based CRAY computer code that is being developed at Lawrence Livermore National Laboratory. The NUSTART code was developed to handle large sets of discrete nuclear levels and the multipole transitions among these levels; it operates in three modes. The Data File Error Analysis mode analyzes an existing STAPLUS input file containing the levels and their multipole transition branches for a number of physics and/or typographical errors. The Interactive Data File Generation mode allows the user to create input files of discrete levels and their branching fractions in the format required by STAPLUS, even though the user enters the information in the (different) format used by many people in the nuclear structure field. In the Branching Fractions Calculations mode, the discrete nuclear level set is read, and the multipole transitions among the levels are computed under one of two possible assumptions: (1) the levels have no collective character, or (2) the levels are all rotational band heads. Only E1, M1, and E2 transitions are considered, and the respective strength functions may be constants or, in the case of E1 transitions, the strength function may be energy dependent. The first option is used for nuclei closed shells; the bandhead option may be used to vary the E1, M1, and E2 strengths for interband transitions. K-quantum number selection rules may be invoked if desired. 19 refs.

  12. Parathion Poisoning from Flannelette Sheets

    PubMed Central

    Anderson, L. S.; Warner, D. L.; Parker, J. E.; Bluman, N.; Page, B. D.

    1965-01-01

    Two small boys were admitted to the Lions Gate Hospital in coma and acute respiratory distress. They improved and the first boy was sent home; after two nights he was back in hospital in a worsened state. Poisoning with organic phosphate was suspected, and after investigation some flannelette sheets were taken from his home for testing. They proved to have been contaminated with parathion (“nerve gas”) in the hold of a ship sailing from Antwerp to Vancouver; the parathion had been offloaded in California. The remainder of the sheets were traced. The symptomatology and treatment of organic phosphate ester poisoning and the chemical testing of parathion are discussed. PMID:14272498

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

    DOEpatents

    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.

  14. Stability codes for a liquid rocket implemented for use on a PC

    NASA Astrophysics Data System (ADS)

    Armstrong, Wilbur; Doane, George C., III; Dean, Garvin

    1992-06-01

    The high frequency code has been made an interactive code using FORTRAN 5.0. The option to plot n-tau curves was added using the graphics routines of FORTRAN 5.0 and GRAFMATIC. The user is now able to run with input values non-dimensional (as in the original code) or dimensional. Input data may be modified from the keyboard. The low and intermediate frequency codes have been run through a set of variations. This will help the user to understand how the stability of a configuration will change if any of the input data changes.

  15. Parathion poisoning of Mississippi kites in Oklahoma

    USGS Publications Warehouse

    Franson, J. Christian

    1994-01-01

    Parathion(phosphorothioic acid O, O-diethyl O-[4-nitrophenyl] ester) is a broad spectrum organophosphorus insecticide, used on a variety of crops and occasionally for mosquito control, and is highly toxic to birds (Smith 1987). Intentional poisoning with parathion is reported to have killed more than 8000 red-winged blackbirds (Agelaius phoeniceus), common grackles (Quiscalus quiscula), brown-headed cowbirds (Molothrus ater) and European starlings (Sturnus vulgaris) in two separate instances (Stone et al. 1984). Use of parathion on wheat fields has resulted in the mortality of about 1600 Canada geese (Branta canadensis) and other waterfowl in one instance (White et al. 1982) and about 200 Canada geese in another (Flickinger et al. 1991). More than 200 laughing gulls (Larus atricilla) died near cotton fields treated with parathion (White et al. 1979). Secondary poisoning of raptors resulting from the consumption of prey exposed to parathion, has been reported experimentally and in the field. Stone et al. (1984) found two dead red-tailed hawks (Buteo jamaicensis), a Cooper's hawk (Accipiter cooperii) and an American kestrel (Falco sparverius) that had fed on blackbirds killed by parathion. One of four American kestrels died after being fed cricket frogs (Acris crepitans) that had been exposed to 10ppm parathion for 96 hr (Fleming et al. 1982). The Mississippi kite (Ictinia mississippensis) is highly insectivorous (Brown and Amadon 1968) and is thus subject to secondary poisoning resulting from consumption of insects exposed to pesticides. I report here an instance of secondary parathion poisoning in wild Mississippi kites.

  16. Chemodynamics of Methyl Parathion and Ethyl Parathion: Adsorption Models for Sustainable Agriculture

    PubMed Central

    Rafique, Uzaira; Balkhair, Khaled S.; Ashraf, Muhammad Aqeel

    2014-01-01

    The toxicity of organophosphate insecticides for nontarget organism has been the subject of extensive research for sustainable agriculture. Pakistan has banned the use of methyl/ethyl parathions, but they are still illegally used. The present study is an attempt to estimate the residual concentration and to suggest remedial solution of adsorption by different types of soils collected and characterized for physicochemical parameters. Sorption of pesticides in soil or other porous media is an important process regulating pesticide transport and degradation. The percentage removal of methyl parathion and ethyl parathion was determined through UV-Visible spectrophotometer at 276 nm and 277 nm, respectively. The results indicate that agricultural soil as compared to barren soil is more efficient adsorbent for both insecticides, at optimum batch condition of pH 7. The equilibrium between adsorbate and adsorbent was attained in 12 hours. Methyl parathion is removed more efficiently (by seven orders of magnitude) than ethyl parathion. It may be attributed to more available binding sites and less steric hindrance of methyl parathion. Adsorption kinetics indicates that a good correlation exists between distribution coefficient (Kd) and soil organic carbon. A general increase in Kd is noted with increase in induced concentration due to the formation of bound or aged residue. PMID:24689059

  17. Chemodynamics of methyl parathion and ethyl parathion: adsorption models for sustainable agriculture.

    PubMed

    Tabassum, Noshabah; Rafique, Uzaira; Balkhair, Khaled S; Ashraf, Muhammad Aqeel

    2014-01-01

    The toxicity of organophosphate insecticides for nontarget organism has been the subject of extensive research for sustainable agriculture. Pakistan has banned the use of methyl/ethyl parathions, but they are still illegally used. The present study is an attempt to estimate the residual concentration and to suggest remedial solution of adsorption by different types of soils collected and characterized for physicochemical parameters. Sorption of pesticides in soil or other porous media is an important process regulating pesticide transport and degradation. The percentage removal of methyl parathion and ethyl parathion was determined through UV-Visible spectrophotometer at 276 nm and 277 nm, respectively. The results indicate that agricultural soil as compared to barren soil is more efficient adsorbent for both insecticides, at optimum batch condition of pH 7. The equilibrium between adsorbate and adsorbent was attained in 12 hours. Methyl parathion is removed more efficiently (by seven orders of magnitude) than ethyl parathion. It may be attributed to more available binding sites and less steric hindrance of methyl parathion. Adsorption kinetics indicates that a good correlation exists between distribution coefficient (Kd) and soil organic carbon. A general increase in Kd is noted with increase in induced concentration due to the formation of bound or aged residue.

  18. Parathion alters incubation behavior of laughing gulls

    USGS Publications Warehouse

    White, D.H.; Mitchell, C.A.; Hill, E.F.

    1983-01-01

    One member of each pair of incubating laughing gulls at 9 nests was trapped, orally dosed with either 6 mg/kg parathion in corn oil or corn oil alone, and marked about the neck with red dye. Each nest was marked with a numbered stake and the treatment was recorded. A pilot study with captive laughing gulls had determined the proper dosage of parathion that would significantly inhibit their brain AChE activity (about 50% of normal) without overt signs of poisoning. After dosing, birds were released and the nests were observed for 2 1/2 days from a blind on the nesting island. The activities of the birds at each marked nest were recorded at 10-minute intervals. Results indicated that on the day of treatment there was no difference (P greater than 0.05, Chi-square test) in the proportion of time spent on the nest between treated and control birds. However, birds dosed with 6 mg/kg parathion spent significantly less time incubating on days 2 and 3 than did birds receiving only corn oil. By noon on the third day, sharing of nest duties between pair members in the treated group had approached normal, indicating recovery from parathion intoxication. These findings suggest that sublethal exposure of nesting birds to an organophosphate (OP) insecticide, such as parathion, may result in decreased nest attentiveness, thereby making the clutch more susceptible to predation or egg failure. Behavioral changes caused by sublethal OP exposure could be especially detrimental in avian species where only one pair member incubates or where both members are exposed in species sharing nest duties.

  19. Interactive toxicity of chlorpyrifos and parathion in neonatal rats: Role of esterases in exposure sequence-dependent toxicity

    SciTech Connect

    Kacham, R.; Karanth, S.; Baireddy, P.; Liu, J.; Pope, C. . E-mail: carey.pope@okstate.edu

    2006-01-15

    We previously reported that sequence of exposure to chlorpyrifos and parathion in adult rats can markedly influence toxic outcome. In the present study, we evaluated the interactive toxicity of chlorpyrifos (8 mg/kg, po) and parathion (0.5 mg/kg, po) in neonatal (7 days old) rats. Rats were exposed to the insecticides either concurrently or sequentially (separated by 4 h) and sacrificed at 4, 8, and 24 h after the first exposure for biochemical measurements (cholinesterase activity in brain, plasma, and diaphragm and carboxylesterase activity in plasma and liver). The concurrently-exposed group showed more cumulative lethality (15/24) than either of the sequential dosing groups. With sequential dosing, rats treated initially with chlorpyrifos prior to parathion (C/P) exhibited higher lethality (7/23) compared to those treated with parathion before chlorpyrifos (P/C; 1/24). At 8 h after initial dosing, brain cholinesterase inhibition was significantly greater in the C/P group (59%) compared to the P/C group (28%). Diaphragm and plasma cholinesterase activity also followed a relatively similar pattern of inhibition. Carboxylesterase inhibition in plasma and liver was relatively similar among the treatment groups across time-points. Similar sequence-dependent differences in brain cholinesterase inhibition were also noted with lower binary exposures to chlorpyrifos (2 mg/kg) and parathion (0.35 mg/kg). In vitro and ex vivo studies compared relative oxon detoxification of carboxylesterases (calcium-insensitive) and A-esterases (calcium-sensitive) in liver homogenates from untreated and insecticide pretreated rats. Using tissues from untreated rats, carboxylesterases detoxified both chlorpyrifos oxon and paraoxon, while A-esterases only detoxified chlorpyrifos oxon. With parathion pretreatment, A-esterases still detoxified chlorpyrifos oxon while liver from chlorpyrifos pretreated rats had little apparent effect on paraoxon. We conclude that while neonatal rats are less

  20. Methyl parathion hydrolase based nanocomposite biosensors for highly sensitive and selective determination of methyl parathion.

    PubMed

    Chen, Shizhen; Huang, Jing; Du, Dan; Li, Jinlin; Tu, Haiyang; Liu, Deli; Zhang, Aidong

    2011-07-15

    This article reports the fabrication of a nanocomposite biosensor for the sensitive and specific detection of methyl parathion. The nanocomposite sensing film was prepared via the formation of gold nanoparticles on silica particles, mixing with multiwall carbon nanotubes and subsequent covalent immobilization of methyl parathion hydrolase. The composite of the individual materials was finely tuned to offer the sensing film with high specific surface area and high conductivity. A significant synergistic effect of nanocomposites on the biosensor performance was observed in biosensing methyl parathion. The square wave voltammetric responses displayed well defined peaks, linearly proportional to the concentrations of methyl parathion in the range from 0.001 μg mL⁻¹ to 5.0 μg mL⁻¹ with a detection limit of 0.3 ng mL⁻¹. The application of this biosensor in the analysis of spiked garlic samples was also evaluated. The proposed protocol can be used as a platform for the simple and fast construction of biosensors with good performance for the determination of enzyme-specific electroactive species.

  1. Parathion utilization by bacterial symbionts in a chemostat.

    PubMed Central

    Daughton, C G; Hsieh, D P

    1977-01-01

    A continuous-culture device was used to select and enrich for microorganisms, from sewage and agricultural runoff, that were capable of using the organophosphorus insecticide parathion as a sole growth substrate. Parathion was dissimilated by the highly acclimated symbiotic activities of Pseudomonas stutzeri, which non-oxidatively and cometabolically hydrolyzed the parathion to ionic diethyl thiophosphate and p-nitrophenol, and P. aeruginosa, which utilized the p-nitrophenol as a sole carbon and energy source. Ionic diethyl thiophosphate was found to be inert to any transformations. Methyl parathion was dissimilated in an analogous way. The device functioned as a chemostat with parathion as the growth-limiting nutrient, and extraordinarily high dissimilation rates were attained for parathion (8 g/liter per day) and for p-nitrophenol (7 g/liter per day). This is the first report of parathion utilization by a defined microbial culture and by symbiotic microbial attack and of dissimilation of an organophosphorus pesticide in a chemostat. PMID:410368

  2. Covalent fabrication of methyl parathion hydrolase on gold nanoparticles modified carbon substrates for designing a methyl parathion biosensor.

    PubMed

    Liu, Guozhen; Guo, Wenqi; Yin, Zhang

    2014-03-15

    A biosensor based on AuNP modified GC electrodes has been developed for direct detection of methyl parathion. AuNP can be introduced to mixed monolayers of aryldiazonium salt modified GC electrodes by Au-C bonding through aryldiazonium salt chemistry, which provides a stable interface showing efficient electron transfer between biomolecules and electrodes. PEG molecules were introduced to the interface to resist non-specific protein adsorption. AuNP surfaces were further modified with 4-carboxyphenyl followed by covalent immobilization of methyl parathion hydrolase (MPH), a specific biocatalytic enzyme to methyl parathion. Exposure of this interface to methyl parathion resulted in a change in amperometric signal due to the MPH catalytic hydrolysis of methyl parathion producing electroactive compound 4-nitrophenol. This biosensor shows high selectivity, specificity, reproducibility and stability, and is functional for the detection of methyl parathion in real samples. The linear range for detection of methyl parathion is 0.2-100 ppb with a detection limit of 0.07 ppb in 0.1M phosphate buffer at pH 7.0.

  3. Genetic surface-display of methyl parathion hydrolase on Yarrowia lipolytica for removal of methyl parathion in water.

    PubMed

    Wang, Xing-Xing; Chi, Zhe; Ru, Shao-Guo; Chi, Zhen-Ming

    2012-09-01

    In this study, the mph gene encoding methyl parathion hydrolase from Pseudomonas sp. WBC-3 was expressed in Yarrowia lipolytica and the expressed methyl parathion hydrolase was displayed on cell surface of Y. lipolytica. The activity of methyl parathion hydrolase displayed on the yeast cells of the transformant Z51 was 59.5 U mg⁻¹ of cell dry cells (450.6 U per mL of the culture) in the presence of 5.0 mM of Co²⁺. The displayed methyl parathion hydrolase had the optimal pH of 9.5 and the optimal temperature of 40 °C, respectively and was stable in the pH range of 4.5-11 and up to 40 °C. The displayed methyl parathion hydrolase was also stimulated by Co²⁺, Cu²⁺, Ni²⁺ and Mn²⁺, and was not affected by Fe²⁺, Fe³⁺, Na⁺, K⁺, Ca²⁺ and Zn²⁺, but was inhibited by other cations tested. Under the optimal conditions (OD(600 nm) = 2.6, the substrate concentration = 100 mg L⁻¹ and 40 °C), 90.8 % of methyl parathion was hydrolyzed within 30 min. Under the similar conditions, 98.7, 97.0, 96.5 and 94.4 % of methyl parathion in tap water (pH 9.5), tap water (pH 6.8), seawater (pH 9.5) and natural seawater (pH 8.2) were hydrolyzed, respectively, suggesting that the methyl parathion hydrolase displayed on the yeast cells can effectively remove methyl parathion in water.

  4. A colorimetric assay for determination of methyl parathion using recombinant methyl parathion hydrolase.

    PubMed

    Anh, Dau Hung; Cheunrungsikul, Kritsananporn; Wichitwechkarn, Jesdawan; Surareungchai, Werasak

    2011-05-01

    A simple, rapid and sensitive colorimetric dipstick assay for the detection of the organophosphorous insecticide methyl parathion (MPT) residue in vegetables was developed. The assay was based on the hydrolysis of MPT by a recombinant methyl parathion hydrolase (recMPH), the encoding gene of which was isolated from Burkholderia cepacia, a soil bacterium indigenous to Thailand. This reaction generates protons leading to a change in pH that correlates with the amount of MPH present. Hence, the pH indicator bromothymol blue was used to monitor the MPH hydrolysis as the associated color changes can be observed by the naked eye. The recMPH was immobilized on a PVDF membrane to establish a dipstick assay format. The assays could detect MPT residues in spiked vegetable samples at the concentration of 1 mg/L without using analytical instrumentation. The test is reusable and stable for up to 3 months in the absence of any preservatives.

  5. External and internal exposure of wine growers spraying methyl parathion.

    PubMed

    Muttray, Axel; Bäcker, Gerhard; Jung, Detlev; Hill, Georg; Letzel, Stephan

    2006-04-10

    Organophosphates, used in agriculture, are readily absorbed through the skin. We investigated the relationship between dermal and inhalative methyl parathion exposure and the plasma levels. Twenty-three healthy wine growers sprayed the insecticide for 50 min. Fluorescent brilliant sulfoflavin was added to the spraying fluids and filter papers were fixed on the subjects. The filter papers were used to evaluate the amount of brilliant sulfoflavine on the unprotected skin fluorometrically. Inhalative exposure was measured with personal air sampler. Plasma concentrations of methyl parathion and its metabolite methyl paraoxon were determined with gas chromatography. Cholinesterase activity in serum and erythrocytes was measured before and after exposure. Some wine growers wore protective clothes, none protective gloves. Dermal exposure ranged up to 12,044 microg, inhalative to 22 microg. Maximum plasma concentration of methyl parathion was 12.1 microg/l. Methyl paraoxon was not detectable. Cholinesterase activity did not decrease. Dermal exposure correlated with the methyl parathion plasma level (Spearman's rho=0.72, p<0.001). In conclusion, dermal exposure exceeded inhalative exposure considerably. Measuring dermal deposition with the brilliant sulfoflavin technique may provide a good estimate of the internal load with methyl parathion. Preventive measures should be improved as toxic effects of repeated exposure to low doses of methyl parathion cannot be excluded.

  6. Biotransformation of the insecticide parathion by mouse brain.

    PubMed

    Soranno, T M; Sultatos, L G

    1992-01-01

    The acute toxicity of organothiophosphate insecticides like parathion results from their metabolic activation by cytochromes P450. The present study is directed towards the characterization of cytochrome-P450-dependent metabolism of parathion by various mouse brain regions. Intraperitoneal administration of [35S]parathion to mice led to covalently bound [35S]sulfur in various tissues, indicating their capacity to oxidatively desulfurate this insecticide. Liver contained the greatest amount of covalently bound sulfur, and brain the least. Among individual brain regions the olfactory bulb and hypothalamus possessed the highest levels of sulfur binding when expressed on a per milligram tissue basis. However, when expressed on a per brain region basis, sulfur binding was greatest within the cortex as a result of the large mass of this region, compared to the hypothalamus and olfactory bulb. Incubation of the 78,000 x g fraction of mouse brain with parathion resulted in formation of p-nitrophenol, although paraoxon could not be detected. However, given the current understanding of parathion metabolism by cytochromes P450, and given that paraoxon can rapidly disappear through phosphorylation of serine hydroxyl groups, it is reasonable to assume that at least some paraoxon was formed. Production of p-nitrophenol required NADPH and was inhibited by carbon monoxide. In vitro incubations of parathion with the 78,000 x g fraction of mouse brain indicated that the hypothalamus and olfactory bulb had the greatest capacity to produce p-nitrophenol. These results demonstrate that various mouse brain regions possess different capacities to metabolize parathion.

  7. DDE increased the toxicity of parathion to coturnix quail

    USGS Publications Warehouse

    Ludke, J.L.

    1977-01-01

    Adult male Japanese quail (Coturnix coturnix) were exposed to DDE or chlordane in the diet and subsequently dosed with parathion or paraoxon. Pretreatment with 5 or 50 ppm DDE in the diet for 12 weeks resulted in increased cholinesterase (ChE) activity in plasma, but not in the brain. Dietary concentrations of 5 and 50 ppm DDE caused increased susceptibility of quail that were challenged with parathion or paraoxon. The increased mortality resulting from DDE pretreatment was reflected in brain ChE inhibition. The synergistic action of DDE was apparent after 3 days of exposure to 50 ppm DDE and 1 week of exposure to 5 ppm DDE. Birds exposed for 3 weeks to 5 or 50 ppm DDE retained their DDE-potentiated sensitivity to parathion after 2 weeks on clean diet. Chlordane pretreatment resulted in decreased susceptibility (antagonism) to parathion, but not to paraoxon dosage. Implications of differing responses in ChE and mortality among controls, DDE-, and chlordane-pretreated birds after parathion or paraoxon dosage are discussed.

  8. Acute responses of American kestrels to methyl parathion and fenvalerate

    USGS Publications Warehouse

    Rattner, B.A.; Franson, J.C.

    1984-01-01

    Physiological and toxicological effects of p.o, methyl parathion (0.375-3.0 mg/kg) or fenvalerate (1000-4000 mg/kg) were examined over a 10 h period in American kestrels (Falco sparverius) maintained in thermoneutral (22?.C) and cold (-5?.C) environments. Methyl parathion was highly toxic (LD50=3.08 mg/kg, 95% confidence limits=2.29-4.l4 mg/kg, producing overt intoxication (abnormal posture, ataxia, paresis), dose-dependent inhibition (26-67%) of brain acetylcholinesterase activity, hyperglycemia, and elevated plasma corticosterone concentration. Transient but pronounced hypothermia was associated with plasma cholinesterase inhibition in excess of 50% (2 h after intubation), although this response was highly variable (plasma ChE inhibition vs. A cloacal temperature, r=-0.60). Fenvalerate, at doses far exceeding those encountered in the environment, caused mild intoxication (irregular head movement) and elevated plasma alanine aminotransferase activity, but did not alter cloacal temperature, plasma activities of CK, U-HBDH, and LDK, or concentrations of corticosterone, glucose, triiodothyronine, and uric acid. Cold exposure intensified methyl parathion toxicity, but did not affect that of fenvalerate. It would thus appear that the organophosphorus insecticide methyl parathion poses far greater hazard than the pyrethroid fenvalerate to raptorial birds.

  9. Interaction of ethanol and the organophosphorus insecticide parathion.

    PubMed

    O'Shaughnessy, J A; Sultatos, L G

    1995-11-27

    Phosphorothioate insecticides such as parathion (O,O-diethyl-O-p-nitrophenyl phosphorothioate) undergo P450-dependent oxidative desulfuration, leading to both activation and detoxification of these compounds. Consequently, alterations in P450-dependent oxidative desulfuration may affect the acute toxicities of these insecticides. In the present study, pretreatment of mice with 15% ethanol in the drinking water for 6 days antagonized the acute toxicity of parathion, but not its toxic metabolite paraoxon (O,O-diethyl-O-p-nitrophenyl phosphate), suggesting that ethanol affected the oxidative desulfuration of this insecticide. The presence of ethanol within hepatic microsomal incubations did not alter the P450-dependent formation of paraoxon (activation) and p-nitrophenol (detoxification), although p-nitrophenol levels were increased in the presence of ethanol as a result of inhibition of its biotransformation to 4-nitrocatechol by CYP2E1. Ethanol exposure reduced hepatic pyruvate levels, but had no effect on levels of lactate, isocitrate, alpha-ketoglutarate, and malate. Calculation of cytosolic NAD+/NADH and cytosolic NADP+/NADPH redox ratios did not reveal any detectable difference in redox state between control and ethanol-treated mice. Since ethanol did not alter directly the P450-dependent activation or detoxification of parathion, and did not decrease NADPH levels, ethanol's antagonism of the acute toxicity of parathion may result from reduced availability of O2.

  10. Accumulation, metabolism and toxicity of parathion in tadpoles

    SciTech Connect

    Hall, R.J. )

    1990-04-01

    Earlier work exposing tadpoles to organophosphorus pesticides indicated the great resistance of tadpoles of the bullfrog (Rana catesbeiana) to these chemicals and their surprising ability to accumulate parathion and fenthion from water. These qualities seemed to make them an ideal model with which to test a hypothesis advanced by Burke and Ferguson, who noted that parathion is more toxic to resistant mosquitofish in static water than in flowing water--a reversal of the pattern normally seen. They believed that highly toxic metabolite paraoxon was produced by the fish and that its buildup in static systems resulted in the unexpected mortality. Amphibians have been shown to produce paraoxon and to accumulate the parent compound parathion to levels that are potentially hazardous to other organisms. In the course of examining paraoxon production by tadpoles, it would also be possible to learn more about their patterns of parathion uptake and elimination. Retention of residues is also a matter of concern given the high levels observed in the earlier studies.

  11. Vitamin K3 (menadione) redox cycling inhibits cytochrome P450-mediated metabolism and inhibits parathion intoxication.

    PubMed

    Jan, Yi-Hua; Richardson, Jason R; Baker, Angela A; Mishin, Vladimir; Heck, Diane E; Laskin, Debra L; Laskin, Jeffrey D

    2015-10-01

    Parathion, a widely used organophosphate insecticide, is considered a high priority chemical threat. Parathion toxicity is dependent on its metabolism by the cytochrome P450 system to paraoxon (diethyl 4-nitrophenyl phosphate), a cytotoxic metabolite. As an effective inhibitor of cholinesterases, paraoxon causes the accumulation of acetylcholine in synapses and overstimulation of nicotinic and muscarinic cholinergic receptors, leading to characteristic signs of organophosphate poisoning. Inhibition of parathion metabolism to paraoxon represents a potential approach to counter parathion toxicity. Herein, we demonstrate that menadione (methyl-1,4-naphthoquinone, vitamin K3) is a potent inhibitor of cytochrome P450-mediated metabolism of parathion. Menadione is active in redox cycling, a reaction mediated by NADPH-cytochrome P450 reductase that preferentially uses electrons from NADPH at the expense of their supply to the P450s. Using human recombinant CYP 1A2, 2B6, 3A4 and human liver microsomes, menadione was found to inhibit the formation of paraoxon from parathion. Administration of menadione bisulfite (40mg/kg, ip) to rats also reduced parathion-induced inhibition of brain cholinesterase activity, as well as parathion-induced tremors and the progression of other signs and symptoms of parathion poisoning. These data suggest that redox cycling compounds, such as menadione, have the potential to effectively mitigate the toxicity of organophosphorus pesticides including parathion which require cytochrome P450-mediated activation.

  12. Protective effects of vitamins C and E against hepatotoxicity induced by methyl parathion in rats.

    PubMed

    Uzunhisarcikli, Meltem; Kalender, Yusuf

    2011-10-01

    Male rats were given vitamins C+E, methyl parathion, or both daily via gavage for seven weeks. Body weight was decreased while liver weight increased significantly at the end of fourth and seventh weeks in the methyl parathion- and methyl parathion plus vitamin-treated groups. Serum total protein, albumin, triglyceride, low density lipoprotein-cholesterol (VLDL-cholesterol) levels decreased, and serum alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl-transferase (GGT), lactate dehydrogenase (LDH), and total cholesterol levels increased significantly in the methyl parathion- and the methyl parathion plus vitamin-treated rats. There was a statistically significant difference for all biochemical parameters when the methyl parathion plus vitamin-treated group was compared with methyl parathion-treated group. In electron microscopic investigation, cytopathological alterations were observed in hepatocytes of the methyl parathion- and the methyl parathion plus vitamin-treated rats. As a result, methyl parathion-induced hepatotoxicity is reduced by vitamins C+E, but vitamins C+E did not provide complete protection.

  13. Isolation of Methyl Parathion-Degrading Strain M6 and Cloning of the Methyl Parathion Hydrolase Gene

    PubMed Central

    Zhongli, Cui; Shunpeng, Li; Guoping, Fu

    2001-01-01

    A degradative bacterium, M6, was isolated and presumptively identified as Plesiomonas sp. strain M6 was able to hydrolyze methyl parathion to p-nitrophenol. A novel organophosphate hydrolase gene designated mpd was selected from its genomic library prepared by shotgun cloning. The nucleotide sequence of the mpd gene was determined. The gene could be effectively expressed in Esherichia coli. PMID:11571204

  14. Hormonal responses and tolerance to cold of female quail following parathion ingestion

    USGS Publications Warehouse

    Rattner, B.A.; Sileo, L.; Scanes, C.G.

    1982-01-01

    Thirty-week-old female bobwhite quail (Colinus virginianus), maintained at 26 + 1?C, were provided diets containing 0,25, or 100 ppm parathion ad libitum. After 10 days, birds were exposed to mild cold (6 + 1?C) for 4,8, 12, 24, or 48 hr. Brain acetylcholinesterase activity was inhibited in a dose-dependent manner in birds receiving 25 and 100 ppm parathion. Body weight, egg production, and plasma luteinizing hormone and progesterone concentrations were reduced in birds receiving 100 ppm parathion compared with other groups. Cold exposure did not alter plasma corticosterone levels in the 0- and 25-ppm parathion groups, but a two- to five fold elevation of plasma corticosterone was observed in birds fed 100 ppm parathion. These findings indicate that (i) short-term ingestion of parathion can impair reproduction possibly by altering gonadotropin or steroid secretion, and (ii) tolerance to cold may be reduced following ingestion of this organophosphate.

  15. Poisoning of Canada geese in Texas by parathion sprayed for control of Russian wheat aphid

    USGS Publications Warehouse

    Flickinger, Edward L.; Juenger, Gary; Roffe, Thomas J.; Smith, Milton R.; Irwin, Roy J.

    1991-01-01

    Approximately 200 Canada geese (Branta canadensis) died at a playa lake in the Texas Panhandle shortly after a winter wheat field in the basin adjacent to the lake was treated with parathion to control newly invading Russian wheat aphids (Diuraphis noxia). No evidence of infectious disease was diagnosed during necropsies of geese. Brain ChE activities were depressed up to 77% below normal. Parathion residues in GI tract contents of geese ranged from 4 to 34 ppm. Based on this evidence, parathion was responsible for the goose mortalities. Parathion applications to winter wheat will undoubtedly increase if parathion is applied for control of both Russian wheat aphids and greenbugs (Schizaphis graminum). Geese may potentially be exposed to widespread applications of parathion from fall to spring, essentially their entire wintering period.

  16. Constitutive Androgen Receptor-Null Mice Are Sensitive to the Toxic Effects of Parathion: Association with Reduced Cytochrome P450-Mediated Parathion MetabolismS⃞

    PubMed Central

    Mota, Linda C.; Hernandez, Juan P.

    2010-01-01

    Constitutive androgen receptor (CAR) is activated by several chemicals and in turn regulates multiple detoxification genes. Our research demonstrates that parathion is one of the most potent, environmentally relevant CAR activators with an EC50 of 1.43 μM. Therefore, animal studies were conducted to determine whether CAR was activated by parathion in vivo. Surprisingly, CAR-null mice, but not wild-type (WT) mice, showed significant parathion-induced toxicity. However, parathion did not induce Cyp2b expression, suggesting that parathion is not a CAR activator in vivo, presumably because of its short half-life. CAR expression is also associated with the expression of several drug-metabolizing cytochromes P450 (P450). CAR-null mice demonstrate lower expression of Cyp2b9, Cyp2b10, Cyp2c29, and Cyp3a11 primarily, but not exclusively in males. Therefore, we incubated microsomes from untreated WT and CAR-null mice with parathion in the presence of esterase inhibitors to determine whether CAR-null mice show perturbed P450-mediated parathion metabolism compared with that in WT mice. The metabolism of parathion to paraoxon and p-nitrophenol (PNP) was reduced in CAR-null mice with male CAR-null mice showing reduced production of both paraoxon and PNP, and female CAR-null mice showing reduced production of only PNP. Overall, the data indicate that CAR-null mice metabolize parathion slower than WT mice. These results provide a potential mechanism for increased sensitivity of individuals with lower CAR activity such as newborns to parathion and potentially other chemicals due to decreased metabolic capacity. PMID:20573718

  17. Involvement of Oxidative Stress in Methyl Parathion and Parathion-Induced Toxicity and Genotoxicity to Human Liver Carcinoma (HepG2) Cells

    PubMed Central

    Edwards, Falicia L.; Yedjou, Clement G.; Tchounwou, Paul B.

    2013-01-01

    Methyl parathion (C8H10NO5PS) and parathion (C10H14NO5PS) are both organophosphate insecticides (OPI) widely used for household and agricultural applications. They are known for their ability to irreversibly inhibit acetylcholinesterase which often leads to a profound effect on the nervous system of exposed organisms. Many recently published studies have indicated that human exposure to OPI may be associated with neurologic, hematopoietic, cardiovascular, and reproductive adverse effects. Studies have also linked OPI exposure to a number of degenerative diseases including Parkinson's, Alzheimer's, and amyotrophic lateral sclerosis. Also, oxidative stress (OS) has been reported as a possible mechanism of OPI toxicity in humans. Hence, the aim of the present investigation was to use human liver carcinoma (HepG2) cells as a test model to evaluate the role of OS in methyl parathion- and parathion-induced toxicity. To achieve this goal, we performed the MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] assay for cell viability, lipid peroxidation assay for malondialdehyde (MDA) production, and Comet assay for DNA damage, respectively. Results from MTT assay indicated that methyl parathion and parathion gradually reduce the viability of HepG2 cells in a dose-dependent manner, showing 48 h-LD50 values of 26.20 mM and 23.58 mM, respectively. Lipid peroxidation assay resulted in a significant increase (p<0.05) of MDA level in methyl parathion- and parathion-treated HepG2 cells compared to controls, suggesting that OS plays a key role in OPI-induced toxicity. Comet assay indicated a significant increase in genotoxicity at higher concentrations of OPI exposure. Overall, we found that methyl-parathion is slightly less toxic than parathion to HepG2 cells. The cytotoxic effect of these OPI was found to be associated, at least in part, with oxidative cell/tissue damage. PMID:21544925

  18. Involvement of oxidative stress in methyl parathion and parathion-induced toxicity and genotoxicity to human liver carcinoma (HepG₂) cells.

    PubMed

    Edwards, Falicia L; Yedjou, Clement G; Tchounwou, Paul B

    2013-06-01

    Methyl parathion (C₈H₁₀NO₅PS) and parathion (C₁₀H14 NO₅PS) are both organophosphate insecticides (OPI) widely used for household and agricultural applications. They are known for their ability to irreversibly inhibit acetylcholinesterase which often leads to a profound effect on the nervous system of exposed organisms. Many recently published studies have indicated that human exposure to OPI may be associated with neurologic, hematopoietic, cardiovascular, and reproductive adverse effects. Studies have also linked OPI exposure to a number of degenerative diseases including Parkinson's, Alzheimer's, and amyotrophic lateral sclerosis. Also, oxidative stress (OS) has been reported as a possible mechanism of OPI toxicity in humans. Hence, the aim of the present investigation was to use human liver carcinoma (HepG₂) cells as a test model to evaluate the role of OS in methyl parathion- and parathion-induced toxicity. To achieve this goal, we performed the MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] assay for cell viability, lipid peroxidation assay for malondialdehyde (MDA) production, and Comet assay for DNA damage, respectively. Results from MTT assay indicated that methyl parathion and parathion gradually reduce the viability of HepG₂ cells in a dose-dependent manner, showing 48 h-LD₅₀ values of 26.20 mM and 23.58 mM, respectively. Lipid peroxidation assay resulted in a significant increase (P < 0.05) of MDA level in methyl parathion- and parathion-treated HepG₂ cells compared with controls, suggesting that OS plays a key role in OPI-induced toxicity. Comet assay indicated a significant increase in genotoxicity at higher concentrations of OPI exposure. Overall, we found that methyl-parathion is slightly less toxic than parathion to HepG₂ cells. The cytotoxic effect of these OPI was found to be associated, at least in part, with oxidative cell/tissue damage.

  19. Bioavailability of methyl parathion adsorbed on clay minerals and iron oxide.

    PubMed

    Cai, Peng; He, Xiaomin; Xue, Aifang; Chen, Hao; Huang, Qiaoyun; Yu, Jun; Rong, Xinming; Liang, Wei

    2011-01-30

    Adsorption, desorption and degradation by Pseudomonas putida of methyl parathion (O,O-dimethyl O-p-nitrophenyl phosphorothioate) on montmorillonite, kaolinite and goethite were studied. Metabolic activities of methyl parathion-degrading bacteria P. putida in the presence of minerals were also monitored by microcalorimetry to determine the degradation mechanism of methyl parathion. Montmorillonite presented higher adsorption capacity and affinity for methyl parathion than kaolinite and goethite. The percentage of degradation of methyl parathion adsorbed on minerals by P. putida was in the order of montmorillonite>kaolinite>goethite. The presence of minerals inhibited the exponential growth and the metabolic activity of P. putida. Among the examined minerals, goethite exhibited the greatest inhibitory effect on bacterial activity, while montmorillonite was the least depressing. The biodegradation of adsorbed methyl parathion by P. putida is apparently not controlled by the adsorption affinity of methyl parathion on minerals and may be mainly governed by the activity of the methyl parathion-degrading bacteria. The information obtained in this study is of fundamental significance for the understanding of the behavior of methyl parathion in soil environments.

  20. [Terahertz spectroscopic investigation of organophosphorus pesticide parathion-methyl].

    PubMed

    Yan, Zhi-Gang; Zheng, Song; Xie, Qiang-Jun; Zhou, Ze-Kui

    2009-10-01

    The present paper reports the theoretical and experimental vibrational spectra of organophosphorus pesticide parathion-methyl in the frequency range from 0.2 to 2.0 THz respectively. Under the room temperature and nitrogen conditions, the absorption peaks were found at 0.65, 1.33, 1.81 and 1.91 THz, and the average refractive index was 1.39 based on the terahertz time-domain spectroscopy (THz-TDS). In parallel with the experimental study, density functional theory (DFT) was applied to obtain the structure and vibrational frequencies of parathion-methyl in the terahertz region. The calculated results are in reasonable agreement with the experimental data. The absorption features are caused by the collective vibrational and torsional modes, and the different absorption peaks correspond to different vibrational modes.

  1. 75 FR 43981 - Methyl Parathion; Rescision of Previously Issued Order and Issuance of Revised Cancellation Order...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... stakeholders including environmental, human health, and agricultural advocates; the chemical industry... chemicals, and does not specifically refer to this cancellation action for methyl parathion. The second... Rice would like EPA to expedite a replacement chemical for methyl parathion, and would support...

  2. Abiotic degradation of methyl parathion by manganese dioxide: Kinetics and transformation pathway.

    PubMed

    Liao, Xiaoping; Zhang, Caixiang; Liu, Yuan; Luo, Yinwen; Wu, Sisi; Yuan, Songhu; Zhu, Zhenli

    2016-05-01

    Methyl parathion, a widely used insecticide around the world, has aroused gradually extensive concern of researchers due to its degradation product such as methyl paraoxon, with higher toxicity for mammals and more recalcitrant. Given the ubiquity of manganese dioxide (MnO2) in soils and aquatic sediments, the abiotic degradation of methyl parathion by α-MnO2 was investigated in batch experiments. It was found that methyl parathion was decomposed up to 90% by α-MnO2 in 30 h and the removal efficiency of methyl parathion depended strongly on the loading of α-MnO2 and pH value in the solution where the reactions followed pseudo-first-order model well. The coexisting metal ions (such as Ca(2+), Mg(2+) and Mn(2+)) weakened markedly the degradation of methyl parathion by α-MnO2. However, the effect of dissolved organic matter (HA-Na) on reaction rates presented two sides: to improve hydrolysis rate but deteriorate oxidation rate of methyl parathion. Based on the degradation products identified by gas chromatography-mass spectrometer (GC/MS) and liquid chromatography high-resolution mass spectrometer (LC/HRMS), both hydrolysis and oxidation processes were proposed to be two predominant reaction mechanisms contributing to methyl parathion degradation by α-MnO2. This study provided meaningful information to elucidate the abiotic dissipation of methyl parathion by manganese oxide minerals in the environment.

  3. Effects of methyl parathion on Chasmagnathus granulatus hepatopancreas: protective role of sesamol.

    PubMed

    Bianchini, Adalto; Monserrat, José Maria

    2007-05-01

    The protective role of sesamol, an inhibitor of the mixed function oxygenase (MFO) system, against histopathological effects of methyl parathion in the hepatopancreas of the estuarine crab, Chasmagnathus granulatus, was studied. Exposure (72 h) to a sublethal dose (0.05 mg/kg/day; 10% of 72 h-LD50) of injected methyl parathion increased the percentage of damaged hepatopancreatic tubules. Presence of melanin-like deposits in the connective tissue between hepatopancreatic tubules was also observed. Antioxidant enzyme activities (catalase and glutathione S-transferase) and lipid peroxidation (LPO) levels were also increased in hepatopancreas of crabs injected with methyl parathion. Pretreatment with sesamol (0.85 mg/kg/day) significantly protected against all these effects. These findings suggest that the hepatopancreatic damages induced by methyl parathion are due to LPO of hepatopancreatocytes membranes, as a consequence of the oxidative stress generated after methyl parathion oxidative biotransformation mediated by the MFO system.

  4. AMPS/PC - AUTOMATIC MANUFACTURING PROGRAMMING SYSTEM

    NASA Technical Reports Server (NTRS)

    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.

  5. Parathion degradation and its intermediate formation by Fenton process in neutral environment.

    PubMed

    Fan, Chihhao; Tsui, Lo; Liao, Ming-Chu

    2011-01-01

    The purpose of this study is to investigate parathion degradation by Fenton process in neutral environment. The initial parathion concentration for all the degradation experiments was 20 ppm. For hydrogen ion effect on Fenton degradation, the pH varied from 2 to 8 at the [H₂O₂] to [Fe²(+)] ratio of 2-2 mM, and the result showed pH 3 as the most effective environment for parathion degradation by Fenton process. Apparent degradation was also observed at pH 7. The subsequent analysis for parathion degradation was conducted at pH 7 because most environmental parathion exists in the neutral environment. Comparing the parathion degradation results at various Fenton dosages revealed that at Fe²(+) concentrations of 0.5, 1.0 and 1.5 mM, the Fenton reagent ratio ([H₂O₂]/[Fe²(+)]) for best-removing performance were found as 4, 3, and 2, resulting in the removal efficiencies of 19%, 48% and 36%, respectively. Further increase in Fe²(+) concentration did not cause any increase of the optimum Fenton reagent ratio for the best parathion removal. The result from LC-MS also indicated that hydroxyl radicals might attack the PS double bond, the single bonds connecting nitro-group, nitrophenol, or the single bond within ethyl groups of parathion molecules forming paraoxons, nitrophenols, nitrate/nitrite, thiophosphates, and other smaller molecules. Lastly, the parathion degradation by Fenton process at the presence of humic acids was investigated, and the results showed that the presence of 10 mg L⁻¹ of humic acids in the aqueous solution enhanced the parathion removal by Fenton process twice as much as that without the presence of humic acids.

  6. Modulation of parathion toxicity by glucose feeding: Is nitric oxide involved?

    SciTech Connect

    Liu Jing . E-mail: jing.pope@okstate.edu; Gupta, Ramesh C.; Goad, John T.; Karanth, Subramanya; Pope, Carey

    2007-03-15

    Glucose feeding can markedly exacerbate the toxicity of the anticholinesterase insecticide, parathion. We determined the effects of parathion on brain nitric oxide and its possible role in potentiation of toxicity by glucose feeding. Adult rats were given water or 15% glucose in water for 3 days and challenged with vehicle or parathion (18 mg/kg, s.c.) on day 4. Functional signs, plasma glucose and brain cholinesterase, citrulline (an indicator of nitric oxide production) and high-energy phosphates (HEPs) were measured 1-3 days after parathion. Glucose feeding exacerbated cholinergic toxicity. Parathion increased plasma glucose (15-33%) and decreased cortical cholinesterase activity (81-90%), with no significant differences between water and glucose treatment groups. In contrast, parathion increased brain regional citrulline (40-47%) and decreased HEPs (18-40%) in rats drinking water, with significantly greater changes in glucose-fed rats (248-363% increase and 31-61% decrease, respectively). We then studied the effects of inhibiting neuronal nitric oxide synthase (nNOS) by 7-nitroindazole (7NI, 30 mg/kg, i.p. x4) on parathion toxicity and its modulation by glucose feeding. Co-exposure to parathion and 7NI led to a marked increase in cholinergic signs of toxicity and lethality, regardless of glucose intake. Thus, glucose feeding enhanced the accumulation of brain nitric oxide following parathion exposure, but inhibition of nitric oxide synthesis was ineffective at counteracting increased parathion toxicity associated with glucose feeding. Evidence is therefore presented to suggest that nitric oxide may play both toxic and protective roles in cholinergic toxicity, and its precise contribution to modulation by glucose feeding requires further investigation.

  7. Removal of methyl parathion in water, by Dugesia dorotocephala.

    PubMed

    Amaya-Chávez, A; López-López, E; Galar-Martínez, M; Gómez-Oliván, L M; García-Fabila, M M

    2009-09-01

    The aim of this study was to determine the efficiency of Dugesia dorotocephala on Methyl parathion removal. An initial concentration of 1.25 microg mL(-1) of MeP was used to evaluate the removal capacity of planarian. A first-order removal kinetics was obtained with a disappearance rate constant (k(r)) of 0.49 days(-1) and 69% efficiency on contaminant removal. This is significantly different (p < 0.5) from the degradation occurring in control systems, leading us to conclude that D. dorotocephala effectively removes MeP from contaminated water.

  8. Toxicity of methyl parathion to bats: Mortality and coordination loss

    USGS Publications Warehouse

    Clark, D.R.

    1986-01-01

    The 24-h oral LD50 of methyl parathion (phosphorothioic acid O,O-dimethyl O-(4-nitrophenyl) ester) to little brown bats (Myotis lucifugus) (372 mg/kg) was 8.5 times the LD50 for mice (Mus musculus) (44 mg/kg). However, orally dosed mice either died or appeared behaviorally normal after 2 to 3 h, whereas many dosed bats, although alive at 24 h, could not right themselves when placed on their backs. The oral dose estimated to cause this loss of coordination in 50% of a sample of big brown bats (Eptesicus fuscus) was one-third or less the LD50 of this species. Cholinesterase activity depression in brains of little brown bats was similar whether dosage was oral or dermal. With death as the criterion, bats proved relatively insensitive to methyl parathion in 24-h tests, but considerations of the chemical's potential to cause coordination loss, leading to capture and death by predators, coupled with bats' naturally low reproductive rates, suggest possible injury to exposed bat populations.

  9. Burkholderia jiangsuensis sp. nov., a methyl parathion degrading bacterium, isolated from methyl parathion contaminated soil.

    PubMed

    Liu, Xu-Yun; Li, Chun-Xiu; Luo, Xiao-Jing; Lai, Qi-Liang; Xu, Jian-He

    2014-09-01

    A methyl parathion (MP) degrading bacterial strain, designated MP-1(T), was isolated from a waste land where pesticides were formerly manufactured in Jiangsu province, China. Polyphasic taxonomic studies showed that MP-1(T) is a Gram-stain-negative, non-spore-forming, rod-shaped and motile bacterium. The bacterium could grow at salinities of 0-1 % (w/v) and temperatures of 15-40 °C. Strain MP-1(T) could reduce nitrate to nitrite, utilize d-glucose and l-arabinose, but not produce indole, or hydrolyse gelatin. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that MP-1(T) belongs to the genus Burkholderia, showing highest sequence similarity to Burkholderia grimmiae DSM 25160(T) (98.5 %), and similar strains including Burkholderia zhejiangensis OP-1(T) (98.2 %), Burkholderia choica LMG 22940(T) (97.5 %), Burkholderia glathei DSM 50014(T) (97.4 %), Burkholderia terrestris LMG 22937(T) (97.2 %) and Burkholderia telluris LMG 22936(T) (97.0 %). In addition, the gyrB and recA gene segments of strain MP-1(T) exhibited less than 89.0 % and 95.1 % similarities with the most highly-related type strains indicated above. The G+C content of strain MP-1(T) was 62.6 mol%. The major isoprenoid quinone was ubiquinone Q-8. The predominant polar lipids comprised phosphatidyl ethanolamine, phosphatidyl glycerol, aminolipid and phospholipid. The principal fatty acids in strain MP-1(T) were C18 : 1ω7c/C18 : 1ω6c (23.3 %), C16 : 0 (16.8 %), cyclo-C17 : 0 (15.0 %), C16 : 1ω7c/C16 : 1ω6 (8.5 %), cyclo-C19 : 0ω8c (8.1 %), C16 : 1 iso I/C14 : 0 3-OH (5.7 %), C16 : 0 3-OH (5.6 %) and C16 : 02-OH (5.1 %). The DNA-DNA relatedness values between strain MP-1(T) and the three type strains (B. grimmiae DSM 25160(T), B. zhejiangensis OP-1(T) and B. glathei DSM 50014(T)) ranged from 24.6 % to 37.4 %. In accordance with phenotypic and genotypic characteristics, strain MP-1(T) represents a novel

  10. Biodegradation of methyl parathion and endosulfan using Pseudomonas aeruginosa and Trichoderma viridae.

    PubMed

    Senthilkumar, S; Anthonisamy, A; Arunkumar, S; Sivakumari, V

    2011-01-01

    Microorganisms play an important role in the bioconversion and total breakdown of pesticides in the environment. This study was conducted to assess the pesticide degradation (endosulfan and methyl parathion) ability of the bacteria and fungi (Pseudomonas aeruginosa and Trichoderma viridae). The screening test conducted to reveal the ability to degrade endosulfan and methyl parathion shows that Trichoderma viridae was effective compared to Pseudomonas aeruginosa. The pesticide degradation was estimated by optical density method. Methyl parathion was highly degraded compared to endosulfan. This study clearly proves that pesticides and their residue degradation can be accelerated by employing microbes which can be effectively utilized both as biocontrol agent and soil cleanser.

  11. Cellulases and coding sequences

    DOEpatents

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

    2001-02-20

    The present invention provides three fungal cellulases, their coding sequences, recombinant DNA molecules comprising the cellulase coding sequences, recombinant host cells and methods for producing same. The present cellulases are from Orpinomyces PC-2.

  12. Cellulases and coding sequences

    DOEpatents

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

    2001-01-01

    The present invention provides three fungal cellulases, their coding sequences, recombinant DNA molecules comprising the cellulase coding sequences, recombinant host cells and methods for producing same. The present cellulases are from Orpinomyces PC-2.

  13. Depression of plasma luteinizing hormone concentration in quail by the anticholinesterase insecticide parathion

    USGS Publications Warehouse

    Rattner, B.A.; Clarke, R.N.; Ottinger, M.A.

    1986-01-01

    To examine the effects of parathion on basal plasma luteinizing hormone (LH) concentration, male Japanese quail (Coturnix japonica) were orally intubated with 0, 5 or 10 mg/kg parathion and sacrificed after 4, 8 and 24 hr. At the 5 mg/kg dose, plasma LH levels were reduced at 4 and 8 hr, but returned to control values by 24 hr. Brain acetylcholinesterase activity was substantially reduced by 10 mg/kg parathion (52, 75 and 37% inhibition at 4, 8 and 24 hr, respectively) and plasma LH concentration remained depressed through the 24-hr period. These findings suggest that the organophosphorus insecticide parathion may alter plasma LH concentration in a manner which might impair reproductive activity, and provide indirect evidence for a cholinergic component in the regulation of LH secretion in quail.

  14. Spectrofluorimetric study of the interaction of methyl-parathion with fish serum albumin.

    PubMed

    Silva, Dilson; Cortez-Moreira, Madelayne; Bastos, Vera Lúcia Freire Cunha; Bastos, Jayme Cunha; Cortez, Célia Martins

    2010-09-01

    The interaction of methyl-parathion with the albumin of Piaractus mesopotamicus (Holmberg 1887) (= pacu), a fish species typical of Brazilian rivers, was studied and the results compared with known values for human and bovine albumin obtained in an earlier investigation. Methyl-parathion (O,O-dimethyl O-p-nitrophenyl phosphorothioate) is an organophosphorous pesticide still used in agriculture and fish farming in many countries. The fluorescence quenching technique with tryptophan as a natural probe was used to detect for the presence of methyl-parathion. Fluorescence can be mathematically expressed by the Stern-Volmer equation to calculate quenching constants, and changes in the behavior of Stern-Volmer curves at different temperatures indicate the nature of the mechanism causing the quenching. Our results indicate that methyl-parathion forms a complex with fish albumin. The estimated association constant is 9.73 x 103 (+/- 4.9 x 102) M(-1) at 25 degrees C.

  15. A model for linking the effects of parathion in soil to its degradation and bioavailability kinetics.

    PubMed

    Saffih-Hdadi, K; Bruckler, L; Lafolie, F; Barriuso, E

    2006-01-01

    Parathion is an insecticide of a group of highly toxic organophosphorus compounds. To investigate the dissipation and toxicological impact of parathion [O,O-diethyl O-(4-nitrophenyl) phosphorothioate] and its highly toxic metabolite, paraoxon, soil laboratory experiments were conducted in columns during a 19-d experiment under variably saturated conditions. Water and pesticide transport, sorption, and biodegradation of parathion were measured in three soil pools (soluble phase, weakly and strongly sorbed phases) using C-labeled pesticide. The effects of parathion and its metabolite on the mobility of soil nematodes were observed and then modeled with an effective variable, which combined pesticide concentration and time of application. Results showed that parathion was highly sorbed and slowly degraded to a mixture of metabolites. The parent compound and its metabolites remained located in the top 0.06-m soil layer. A kinetic model describing the sorption, biodegradation, and allocation into different soil pools of parathion and its metabolites was coupled with heat and water transport equations to predict the fate of parathion in soil. Simulated results were in agreement with experimental data, showing that the products remained in the upper soil layers even in the case of long-term (11-mo) simulation. The strongly sorbed fraction may be regarded as a pesticide reservoir that regularly provides pesticide to the weakly sorbed phase, and then, liquid phase, respectively. From both modeling and observations, no major toxicological damage of parathion and paraoxon to soil nematodes was found, although some effects on nematodes were possible, but at the soil surface only (0.01- and 0.02-m depth).

  16. Behavior of parathion in apple juice processed into cider and vinegar.

    PubMed

    Banna, A A; Kawar, N S

    1982-01-01

    Apple juice, fortified with 25 ppm (ug/g) of parathion, was processed into cider and vinegar. After the initial fermentation period of 12 days, the supernatant cider contained 7.4 ppm of parathion while the level in the sedimented lees was 88 ppm. Sorption to the sedimented matter was the main pathway for parathion residue reduction in the cider. Levels of aminoparathion and 4-nitrophenol, the only metabolites of parathion detected as confirmed by thin-layer chromatography, were 0.19 and 1.2 ppm, respectively, in the cider. The 56-day-old finished cider prior to bottling contained 2.2 ppm parathion, 0.15 ppm aminoparathion and 1.3 ppm 4-nitrophenol. Storage of the cider at 24, 12, 4 and -20 degrees C resulted in further reduction in the parathion levels. After one year, samples stored at 24 degrees C contained only 2.5% of the initial level added to the juice. Samples stored at the three other temperatures contained about 5% of the original level. Vinegar formed after 57 days of fermentation contained 5.1 ppm parathion, while the residue level in the lees was 76 ppm. Aminoparathion and 4-nitrophenol levels were 0.23 and 1.2 ppm, respectively in the vinegar. Storage of the vinegar at 24 degrees C for one year resulted in a gradual decline in the parathion level and at the end of the storage period, the remaining residue represented about 6% of the initial 24 ppm added to the juice.

  17. Studies on the metabolism of diethyl 4-nitrophenyl phosphorothionate (parathion) in vitro.

    PubMed

    Neal, R A

    1967-04-01

    1. The metabolism of the phosphorothionate parathion in vitro was examined by using [(32)P]parathion and microsomes isolated from the livers of various animal species. 2. The major metabolic products of parathion in this system in vitro were identified as diethyl 4-nitrophenyl phosphate (paraoxon), diethyl hydrogen phosphate, diethyl hydrogen phosphorothionate and p-nitrophenol. 3. The reaction leading to the formation of diethyl hydrogen phosphorothionate and p-nitrophenol requires the same cofactors (NADPH and oxygen) required for metabolism of parathion to its active anti-acetylcholinesterase paraoxon. 4. The enzyme activity towards parathion per unit weight of liver is increased some 65-130% by pretreatment of male rats with phenobarbital and 3,4-benzopyrene. 5. The metabolism of parathion is inhibited by incubation in a nitrogen atmosphere and in an atmosphere containing carbon monoxide. Pure oxygen is also inhibitory. These results are discussed in terms of a deficiency of oxygen for maximal activity as well as the lability of some component of the system to oxidation.

  18. Graphene modified screen printed immunosensor for highly sensitive detection of parathion.

    PubMed

    Mehta, Jyotsana; Vinayak, Priya; Tuteja, Satish K; Chhabra, Varun A; Bhardwaj, Neha; Paul, A K; Kim, Ki-Hyun; Deep, Akash

    2016-09-15

    Due to indiscriminate use of pesticides, there is a growing need to develop sensors that can sensitively detect the trace amount of pesticides in food and water samples. Parathion, identified as an acetylcholinesterase inhibitor, had been one of the most widely used pesticides throughout the world. Symptoms of its poisoning are found to be diverse enough to include nausea, vomiting, diarrhea, muscle cramping/twitching, and shortness of breath. In this work, a graphene based impedimetric immunosensor has been fabricated and employed for highly sensitive and specific detection of parathion. The fabrication proceeded through the modification of the screen-printed carbon electrodes (SPE) with graphene sheets, followed by their functionalization with 2-aminobenzyl amine (2-ABA) via an electrochemical reaction. These amine functionalized graphene electrodes were then bio-interfaced with the anti-parathion antibodies. In the impedimetric mode, this biosensor detected parathion in a broad linear range, i.e. 0.1-1000ng/L with a very low limit of detection (52pg/L). It also showed high selectivity towards parathion in the presence of malathion, paraoxon, and fenitrothion. The viability of this biosensor was demonstrated by detecting parathion in real samples (e.g., tomato and carrot) and through cross-calibration against HPLC.

  19. Reduced glutathione attenuates liver injury induced by methyl parathion in rats.

    PubMed

    Jiang, Na; Lu, Lina; Wang, Tian; Zhang, Leiming; Xin, Wenyu; Fu, Fenghua

    2010-02-01

    The aim of this study was to investigate whether exogenous reduced glutathione (GSH) could protect liver injury induced by methyl parathion. Rats were allocated into four groups named as control, MP (methyl parathion poisoning), MP+GSH1 (methyl parathion poisoning treated with GSH 600 mg/kg), and MP+GSH2 (methyl parathion poisoning treated with GSH 1200 mg/kg). Each one of the last three groups was assigned into 6 h, 24 h, and 72 h sub-groups. The activities of acetylcholinesterase (AChE), glutamate pyruvate transaminase (GPT), and glutamic oxalacetic transaminase (GOT) in plasma, and superoxide dismutase (SOD) and glutathione peroxidase (GPx) in liver were assayed. The malondialdehyde (MDA) in liver was also determined. Histopathological changes in liver were observed. Results showed that AChE activity was significantly inhibited by methyl parathion and attenuated after GSH administered. GSH could relieve hepatocellular edema and fatty degeneration, and attenuate the increased activities of GPT and GOT. GSH treatment increased the SOD and GPx activities, but had no effect on the MDA level. These results indicated that GSH could attenuate liver injury induced by methyl parathion.

  20. Simultaneous detection of imidacloprid and parathion by the dual-labeled time-resolved fluoroimmunoassay.

    PubMed

    Shi, Haiyan; Sheng, Enze; Feng, Lu; Zhou, Liangliang; Hua, Xiude; Wang, Minghua

    2015-10-01

    A highly sensitive direct dual-labeled time-resolved fluoroimmunoassay (TRFIA) to detect parathion and imidacloprid simultaneously in food and environmental matrices was developed. Europium (Eu(3+)) and samarium (Sm(3+)) were used as fluorescent labels by coupling separately with L1-Ab and A1P1-Ab. Under optimal assay conditions, the half-maximal inhibition concentration (IC50) and limit of detection (LOD, IC10) were 10.87 and 0.025 μg/L for parathion and 7.08 and 0.028 μg/L for imidacloprid, respectively. The cross-reactivities (CR) were negligible except for methyl-parathion (42.4 %) and imidaclothiz (103.4 %). The average recoveries of imidacloprid ranged from 78.9 to 104.2 % in water, soil, rice, tomato, and Chinese cabbage with a relative standard deviation (RSD) of 2.4 to 11.6 %, and those of parathion were from 81.5 to 110.9 % with the RSD of 3.2 to 10.5 %. The results of TRFIA for the authentic samples were validated by comparison with gas chromatography (GC) analyses, and satisfactory correlations (parathion: R (2) = 0.9918; imidacloprid: R (2) = 0.9908) were obtained. The results indicate that the dual-labeled TRFIA is convenient and reliable to detect parathion and imidacloprid simultaneously in food and environmental matrices.

  1. Biomimicry 1: PC.

    PubMed

    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.

  2. Kinetics and mechanism of the degradation of methyl parathion in aqueous hydrogen sulfide solution: investigation of natural organic matter effects.

    PubMed

    Guo, Xiaofen; Jans, Urs

    2006-02-01

    The kinetics of the transformation of methyl parathion have been investigated in aqueous solution containing reduced sulfur species and small concentrations of natural organic matter (NOM) from different sources such as soil, river, and peat. It was shown that NOM mediates the degradation of methyl parathion in aqueous solutions containing hydrogen sulfide. After evaluating and quantifying the effect of the NOM concentration on the degradation kinetics of methyl parathion in the presence of hydrogen sulfide, it was found that the observed pseudo-first-order reaction rate constants (k(obs)) were proportional to NOM concentrations. The influence of pH on the degradation of methyl parathion in the aqueous solutions containing hydrogen sulfide and NOM has been studied. The rate of degradation of methyl parathion was strongly pH dependent. The results indicate k(obs) with a commercially available humic acid has a maximum value at approximately pH 8.3. Two main reaction mechanisms are identified to dominate the degradation of methyl parathion in aqueous solution containing hydrogen sulfide and NOM based on the products aminomethyl parathion and desmethyl methyl parathion. The two mechanisms are nitro-group reduction and nucleophilic attack at the methoxy-carbon. The reduction of the nitro-group is only observed in the presence of NOM. The results of this study form an important base for the evaluation and interpretation of transformation processes of methyl parathion in the environment.

  3. Scale-PC shielding analysis sequences

    SciTech Connect

    Bowman, S.M.

    1996-05-01

    The SCALE computational system is a modular code system for analyses of nuclear fuel facility and package designs. With the release of SCALE-PC Version 4.3, the radiation shielding analysis community now has the capability to execute the SCALE shielding analysis sequences contained in the control modules SAS1, SAS2, SAS3, and SAS4 on a MS- DOS personal computer (PC). In addition, SCALE-PC includes two new sequences, QADS and ORIGEN-ARP. The capabilities of each sequence are presented, along with example applications.

  4. Poster session ELIPGRID-PC

    SciTech Connect

    Davidson, J.R.

    1995-02-01

    ELIPGRID-PC, a new personal computer program, has been developed to provide easy access to Singer`s ELIPGRID algorithm for hot-spot detection probabilities. Three features of the program are the ability to determine: (1) the grid size required for specified conditions, (2) the smallest hot spot that can be sampled with a given probability, and (3) the approximate grid size resulting from specified conditions and sampling cost. ELIPGRID-PC also provides probability of detection versus cost data for graphing with spreadsheets or graphics software. The program has been successfully tested using Singer`s published ELIPGRID results. An apparent error in the published ELIPGRID code has been uncovered and an appropriate modification incorporated into the new program.

  5. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-10-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org.

  6. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-12-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org.

  7. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-11-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org.

  8. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2017-03-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org.

  9. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-07-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org.

  10. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-06-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org.

  11. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2017-02-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org.

  12. Monte Carlo tests of the ELIPGRID-PC algorithm

    SciTech Connect

    Davidson, J.R.

    1995-04-01

    The standard tool for calculating the probability of detecting pockets of contamination called hot spots has been the ELIPGRID computer code of Singer and Wickman. The ELIPGRID-PC program has recently made this algorithm available for an IBM{reg_sign} PC. However, no known independent validation of the ELIPGRID algorithm exists. This document describes a Monte Carlo simulation-based validation of a modified version of the ELIPGRID-PC code. The modified ELIPGRID-PC code is shown to match Monte Carlo-calculated hot-spot detection probabilities to within {plus_minus}0.5% for 319 out of 320 test cases. The one exception, a very thin elliptical hot spot located within a rectangular sampling grid, differed from the Monte Carlo-calculated probability by about 1%. These results provide confidence in the ability of the modified ELIPGRID-PC code to accurately predict hot-spot detection probabilities within an acceptable range of error.

  13. Enhancement of parathion toxicity to quail by heat and cold exposure

    USGS Publications Warehouse

    Rattner, B.A.; Becker, J.M.; Nakatsugawa, T.

    1987-01-01

    Effects of ambient temperature on the acute oral toxicity of parathion were investigated in Japanese quail (Coturnix japonica) maintained at thermoneutral temperature (26.degree. C) or exposed to elevated (37.degree. C) or reduced (4.degree. C) temperatures commonly encountered by free-ranging wild birds. Based upon estimates of the median lethal dosage, there was up to a two-fold enhancement of parathion toxicity in birds chronically exposed to heat or cold. Twenty-four hours after administration of a low dosage (4 mg/kg body wt, po), there was markedly greater cholinesterase inhibition in surviving heat-exposed quail compared with those reared at 26.degree. C (e.g., brain acetylcholinesterase depression of 42% versus 12%). There were no differences in hepatic activities of parathion oxidase, paraoxonase, or paraoxon deethylase which could account for greater toxicity to chronically heat-exposed birds. In contrast, 4 mg parathion/kg wt elicited less plasma cholinesterase inhibition in cold-exposed quail compared to thermoneutral controls (e.g., < 10% versus 48% depression after 24 hr). Increased liver weight and a doubling of paraoxonase activity may have been associated with greater tolerance to sublethal doses of parathion in chronically cold-exposed quail. These findings, together with limited field observations, indicate that the hazard associated with anticholinesterase exposure of wild birds is substantially influenced by environmental temperature.

  14. Bioconcentration and Acute Intoxication of Brazilian Freshwater Fishes by the Methyl Parathion Organophosphate Pesticide

    PubMed Central

    Bosco de Salles, João; Matos Lopes, Renato; de Salles, Cristiane M. C.; Cassano, Vicente P. F.; de Oliveira, Manildo Marcião; Cunha Bastos, Vera L. F.; Bastos, Jayme Cunha

    2015-01-01

    Three species of freshwater Brazilian fishes (pacu, Piaractus mesopotamicus; piavussu, Leporinus macrocephalus, and curimbatá, Prochilodus lineatus) were exposed to an acute dose of 5 ppm methyl parathion organophosphate pesticide. Three to five individuals per species were exposed, one at a time, to 40 liters tap water spiked with Folidol 600. Pesticide concentrations and cholinesterase (ChE) activities were evaluated in serum, liver, brain, heart, and muscle. The bioconcentration of methyl parathion was similar for all studied fishes. Brain tissue showed the highest pesticide concentration, reaching 80 ppm after exposure for 30 min to methyl parathion. Three to 5 hours of 5 ppm methyl parathion exposure provoked the death of all P. lineatus at 92% brain AChE inhibition, whereas fish from the other two species survived for up to 78 hours with less than 80% brain AChE inhibition. Our results indicate that acute toxic effects of methyl parathion to fish are correlated with brain AChE sensitivity to methyl paraoxon. PMID:26339593

  15. Effects on wildlife of ethyl and methyl parathion applied to California rice fields

    USGS Publications Warehouse

    Custer, T.W.; Hill, E.F.; Ohlendorf, H.M.

    1985-01-01

    Selected rice fields on the Sacramento National Wildlife Refuge Complex were aerially sprayed one time during May or June 1982 with either ethyl (0.11 kg Al/ha) or methyl (0.84 kg AI/ha) parathion for control of tadpole shrimp, Triops longicaudatus. No sick or dead vertebrate wildlife were found or adjacent to the treated rice fields after spraying. Specimens of the following birds and mammals were assayed for brain cholinesterase (ChE) activity to determine exposure to either form of parathion; house mouse, Mus musculus; black-tailed jackrabbit, Lepus californicus; mallard, Anas platyrhynchos; ring-necked pheasant, Phasianus colchicus; American coot, Fulica americana; and red-winged blackbird, Agelaius phoeniceus. Both mice and pheasants from methyl parathion-treated fields had overall mean ChE activities that were significantly (P < 0.05) inhibited compared with controls, and 7, 40, 54 and 57% of individual blackbirds, pheasant, mice, and coots, respectively, had inhibited brain ChE activities (i.e., less than -2 SD of control mean). Although no overall species effect was detected for ethyl parathoid treatment, pheasants (43%), coots (33%), and mice (37%) had significantly inhibited brain ChE activities. Neither of the parathion treatment appeared acutely hazardous to wildlife in or adjacent to rice fields, but sufficient information on potential hazards was obtained to warrant caution in use of these chemicals, especially methyl parathion, in rice fields.

  16. Effects of wildlife of ethyl and methyl parathion applied to California USA rice fields

    USGS Publications Warehouse

    Custer, T.W.; Hill, E.F.; Ohlendorf, H.M.

    1985-01-01

    Selected rice fields on the Sacramento National Wildlife Refuge Complex were aerially sprayed one time during May or June 1982 with either ethyl (0.11 kg Al/ha) or methyl (0.84 kg AI/ha) parathion for control of tadpole shrimp, Triops longicaudatus. No sick or dead vertebrate wildlife were found or adjacent to the treated rice fields after spraying. Specimens of the following birds and mammals were assayed for brain cholinesterase (ChE) activity to determine exposure to either form of parathion; house mouse, Mus musculus; black-tailed jackrabbit, Lepus californicus; mallard, Anas platyrhynchos; ring-necked pheasant, Phasianus colchicus; American coot, Fulica americana; and red-winged blackbird, Agelaius phoeniceus. Both mice and pheasants from methyl parathion-treated fields had overall mean ChE activities that were significantly (P < 0.05) inhibited compared with controls, and 7, 40, 54 and 57% of individual blackbirds, pheasant, mice, and coots, respectively, had inhibited brain ChE activities (i.e., less than -2 SD of control mean). Although no overall species effect was detected for ethyl parathoid treatment, pheasants (43%), coots (33%), and mice (37%) had significantly inhibited brain ChE activities. Neither of the parathion treatment appeared acutely hazardous to wildlife in or adjacent to rice fields, but sufficient information on potential hazards was obtained to warrant caution in use of these chemicals, especially methyl parathion, in rice fields.

  17. Bioconcentration and Acute Intoxication of Brazilian Freshwater Fishes by the Methyl Parathion Organophosphate Pesticide.

    PubMed

    de Salles, João Bosco; Lopes, Renato Matos; de Salles, Cristiane M C; Cassano, Vicente P F; de Oliveira, Manildo Marcião; Bastos, Vera L F Cunha; Bastos, Jayme Cunha

    2015-01-01

    Three species of freshwater Brazilian fishes (pacu, Piaractus mesopotamicus; piavussu, Leporinus macrocephalus, and curimbatá, Prochilodus lineatus) were exposed to an acute dose of 5 ppm methyl parathion organophosphate pesticide. Three to five individuals per species were exposed, one at a time, to 40 liters tap water spiked with Folidol 600. Pesticide concentrations and cholinesterase (ChE) activities were evaluated in serum, liver, brain, heart, and muscle. The bioconcentration of methyl parathion was similar for all studied fishes. Brain tissue showed the highest pesticide concentration, reaching 80 ppm after exposure for 30 min to methyl parathion. Three to 5 hours of 5 ppm methyl parathion exposure provoked the death of all P. lineatus at 92% brain AChE inhibition, whereas fish from the other two species survived for up to 78 hours with less than 80% brain AChE inhibition. Our results indicate that acute toxic effects of methyl parathion to fish are correlated with brain AChE sensitivity to methyl paraoxon.

  18. Effect of methyl parathion on nitrous oxide production: a laboratory study.

    PubMed

    Rojas-Oropeza, Marcelo; Fernández, Francisco J; Dendooven, Luc; Cabirol, Nathalie

    2012-03-01

    We investigated the diversity of a denitrifying gene (nirK) and the emission of CO(2) and N(2)O, in a "chinampa" soil contaminated with methyl parathion. Soil at 40% of water holding capacity was spiked with methyl parathion at four concentrations (i.e. 0, 0.7, 1.47 and 4.27 g kg(-1) dry soil), while emission of N(2)O and CO(2) and nirK diversity was determined after 0, 1, 14, 30, 60 and 90 days. The emission of N(2)O on a daily base and the cumulative emission of CO(2) was not affected by the different concentrations of methyl parathion applied to soil. The diversity of the nirK gene, determined by using temperature gradient gel electrophoresis (TGGE), decreased with increased methyl parathion application. It was found that methyl parathion had effect on the emissions of N(2)O and CO(2), and reduced the diversity of the nirK gene. Consequently, the reduced diversity of the nirK gene could affect the emission of N(2)O.

  19. A molecularly imprinted polymer based on functionalized multiwalled carbon nanotubes for the electrochemical detection of parathion-methyl.

    PubMed

    Zhang, Dan; Yu, Dajun; Zhao, Wenjie; Yang, Qinyan; Kajiura, Hisashi; Li, Yongming; Zhou, Tianshu; Shi, Guoyue

    2012-06-07

    A novel composite of vinyl group functionalized multiwalled carbon nanotubes (MWCNTs) molecularly imprinted polymer (MIP) was synthesized and applied as a molecular recognition element to construct an electrochemical sensor for parathion-methyl in this paper. The special molecular recognition properties of parathion-methyl mainly dominated by π-π, p-π interaction and hydrogen bonding formed among functional monomer, template and matrix. A series of electrochemical experiment results proved that the prepared material had good adsorption capacity and fast mass transfer rate to parathion-methyl. The good selectivity of the sensor allowed fine discrimination between parathion and paraoxon, which had similar structures to parathion-methyl. The response of the MIPs was linearly proportional to the concentration of parathion-methyl over the range of 2.0 × 10(-7) to 1.0 × 10(-5) mol L(-1) with a lower detection limit of 6.7 × 10(-8) mol L(-1) (S/N = 3). This sensor was also applied in the detection of parathion-methyl in pear and cucumber with average recoveries of between 94.9% and 106.2% (RSD < 5%) being obtained. The results mentioned above show that the novel electrochemical sensor is an ideal device for the real-time determination of parathion-methyl in real samples.

  20. Absence of circannual toxicity of parathion to starlings

    USGS Publications Warehouse

    Rattner, B.A.; Grue, C.E.

    1990-01-01

    Ambient temperature and season have been observed to influence the toxicity of several environmental pollutants in homeotherms. The circannual toxicity of ethyl parathion (EP) was examined in adult European starlings (Sturnus vulgaris). Groups of birds housed in outdoor pens received oral doses of EP (20-150 mg/kg body weight) in fall, winter, spring and summer (temperature range -3.3 to 36.7?C). The median lethal dosage (LD50), and brain and plasma cholinesterase inhibition, were found to be quite similar among seasons. There was some suggestion that EP may have been more toxic during hot weather (winter versus summer LD50 estimate [95% confidence interval]:160 [114-225] vs. 118 [102-136] mg/kg; P<0.10). In view of previous reports in which ambient temperature extremes and harsh weather have enhanced organophosphorus insecticide toxicity to birds, it is concluded that circannual toxicity studies should include measures of sensitivity (acute oral exposure) and vulnerability (dietary exposure) to better predict responses of free-ranging birds

  1. Methyl parathion in residential properties: relocation and decontamination methodology.

    PubMed Central

    Clark, J Milton; Bing-Canar, John; Renninger, Steve; Dollhopf, Ralph; El-Zein, Jason; Star, Dave; Zimmerman, Dea; Anisuzzaman, Abul; Boylan, Kathline; Tomaszewski, Terrence; Pearce, Ken; Yacovac, Rebecca; Erlwein, Bobby; Ward, John

    2002-01-01

    In November 1994 methyl parathion (MP), a restricted agricultural pesticide, was discovered to have been illegally sprayed within hundreds of residences in Lorain County, Ohio. Surface levels and air concentrations of MP revealed detectable levels of the pesticide 3 years after spraying. Because of the high toxicity of MP (lethal dose to 50% of rats tested [LD50] = 15 mg/kg) and long half-life indoors, risk-based relocation and decontamination criteria were created. Relocation criteria were derived based on levels of p-nitrophenol in urine, a metabolic byproduct of MP exposure. In Ohio, concentrations of MP on surfaces and in the air were also used to trigger relocations. The criteria applied in Ohio underwent refinement as cases of MP misuse were found in Mississippi and then in several other states. The MP investigation (1994-1997) was the largest pesticide misuse case in the nation, ultimately involving the sampling of 9,000 residences and the decontamination of 1,000 properties. This article describes the methodology used for relocation of residents and decontamination of properties having MP. PMID:12634141

  2. Analytical and toxicological studies of decomposition of insecticide parathion after gamma-irradiation and ozonation.

    PubMed

    Bojanowska-Czajka, Anna; Torun, Murat; Kciuk, Gabriel; Wachowicz, Mariusz; Ozbay, Dilek Solpan; Guven, Olgun; Bobrowski, Krzysztof; Trojanowicz, Marek

    2012-01-01

    The decomposition of the widely used organophosphorus pesticide parathion was carried out in aqueous solutions by the use of gamma-irradiation from a 60Co source or ozonation by means of an ozone generator, and by combined processes of ozonation and radiolysis. Factors affecting the parathion decomposition as well formation and decomposition of the main by-products, including irradiation dose, length of ozonation time, and presence of common scavengers, were investigated. The most efficient was found to be the gamma-irradiation process combined with a short ozonation period; about 1 kGy irradiation dose was sufficient to decompose the pesticide in 15 mg/L solutions. Chemical studies of the decomposition of parathion were accompanied by monitoring of toxicity changes of irradiated solutions with the Microtox test.

  3. Toxicity of parathion to captive European starlings (Sturnus vulgaris)-absence of seasonal effects

    USGS Publications Warehouse

    Rattner, B.A.; Grue, C.E.

    1990-01-01

    The effects of season on the toxicity of the prototypic organophosphorus insecticide parathion was evaluated using adult European starlings (Sturnus vulgaris) housed in outdoor pens. Groups of birds received oral doses of parathion in the fall, winter, spring and summer. Median lethal dosage, and brain and plasma cholinesterase inhibition, were found to be quite similar among seasons. Parathion may have been more toxic during hot weather (winter vs. summer LD50 estimate: 160 vs. 118 mg/kg; p < 0.1). In view of previous reports in which ambient temperature extremes and harsh weather have enhanced organophosphorus insecticide toxicity to birds, it is concluded that circannual toxicity studies should include measures of sensitivity (acute oral exposure) and vulnerability (dietary exposure) to better predict responses of free-ranging birds.

  4. Parathion accumulation in cricket frogs and its effect on American kestrels

    USGS Publications Warehouse

    Fleming, W.J.; de Chacin, H.; Pattee, O.H.; Lamont, T.G.

    1982-01-01

    Adult cricket frogs (Acris crepitans) were held individually for 96 h in static systems containing initial concentrations of either 0, 0.1, 1.0, or 10 ppm parathion in 10 ml water. Mortality of cricket frogs was directly related to the parathion concentration in the water. Frogs from the 1.0- and 10-ppm groups accumulated 0.08 and 4.6 ppm parathion, respectively. One of four American kestrels (Falco sparverius) fed frogs from the 10-ppm group died from organophosphate poisoning less than 3 h after consuming five frogs. Mortality did not occur in kestrels fed frogs from the other treatment groups, which represented more environmentally realistic levels of exposure.

  5. Toxicity of cadmium, lead, mercury and methyl parathion on Euchlanis dilatata Ehrenberg 1832 (Rotifera: Monogononta).

    PubMed

    Arias-Almeida, Juan Carlos; Rico-Martínez, Roberto

    2011-08-01

    Acute toxicity tests with Cd, Pb, Hg, and methyl parathion were developed to compare the sensitivity of the rotifer Euchlanis dilatata with other model organisms used in aquatic ecotoxicology. Cd was the most toxic chemical (LC50 = 14.8 μg L(-1)), while methyl parathion was the least toxic (LC50 = 864.2 μg L(-1)). E. dilatata was more sensitive that other rotifer species, particularly of the genera Brachionus and Lecane. However, E. dilatata was less sensitive to mercury and methyl parathion than the crustacean, Daphnia magna. The high sensitivity of E. dilatata suggests that it may be an adequate benthic model to use in toxicity assessments of metal-contaminated sediments.

  6. Probing the simulant behavior of PNPDPP toward parathion and paraoxon: a computational study.

    PubMed

    Khan, Abdul Shafeeuulla; Bandyopadhyay, Tusar; Ganguly, Bishwajit

    2012-04-01

    The extreme toxicity of organophosphorus nerve agents and pesticides mandates to employ models or simulants in place of the actual compounds in the laboratory. The importance of simulants is known, however, their efficacy for direct comparison with the toxic organophosphorus compounds is not well documented. We have examined the potential energy surfaces (PES) for the alkaline hydrolysis of pesticides like paraoxon (diethyl 4-nitrophenyl phosphate), parathion (O,O-diethyl O-4-nitrophenyl phosphorothioate) and PNPDPP (4-nitrophenyl diphenyl phosphate), a simulant with MP2/6-311+G*//B3LYP/6-311+G*+ΔG(solv) (HF/6-31+G*) level of theory. The effect of aqueous solvation was considered with the Integral Equation Formalism Polarizable Continuum Model (IEF-PCM). The alkaline hydrolysis of these organophosphorus compounds reveals that the reaction proceeds through the attack of hydroxide ion at the phosphorus center to form a pentacoordinate intermediate. The calculated free energies of activation for the alkaline hydrolysis of paraoxon and parathion are in good agreement with the available experimental activation free energies. The computed results show that the reaction profiles for the alkaline hydrolysis of paraoxon, parathion and PNPDPP are largely similar; however, the rate of hydrolysis of parathion may be higher than that of paraxon and PNPDPP. Such difference arises due to the less electrophilic nature of the phosphorus atom of parathion molecule as observed in the charge analysis study. The conceptual DFT analysis also showed the similar trend for the alkaline hydrolysis of paraoxon, parathion and PNPDPP with hydroxide anion. This computational study provides a quantitative support toward the use of PNPDPP as a simulant for organophosphorus compounds, which cannot be used directly for the laboratory purposes.

  7. Urinary paranitrophenol, a metabolite of methyl parathion, in Thai farmer and child populations.

    PubMed

    Panuwet, Parinya; Prapamontol, Tippawan; Chantara, Somporn; Thavornyuthikarn, Prasak; Bravo, Roberto; Restrepo, Paula; Walker, Robert D; Williams, Bryan L; Needham, Larry L; Barr, Dana B

    2009-10-01

    Human exposure to methyl parathion can be assessed by measuring the concentration of its metabolite paranitrophenol (PNP) in urine. Our biologic monitoring study in Chiang Mai, Thailand, measured PNP and dialkylphosphate metabolites (i.e., dimethylphosphate [DMP] and dimethylthiophosphate [DMTP]) of methyl parathion in urine samples collected from 136 farmers (age 20 to 65 years) and 306 school children (age 10 to 15 years) in 2006. Participants came from two topographically different areas: one was colder and mountainous, whereas the other was alluvial with climate fluctuations depending on the monsoon season. Both children and farmers were recruited from each area. Despite methyl parathion's prohibited use in agriculture in 2004, we detected PNP in >90% of all samples analyzed. We applied a nonparametric correlation test (PNP vs. DMP and DMTP) to determine whether the PNP found in most of the samples tested resulted from exposures to methyl parathion. DMP (Spearman's rho = 0.601 [p = 0.001] for farmers and Spearman's rho = 0.263 [p <0.001] for children) and DMTP (Spearman's rho = 0.296 [p = 0.003] for farmers and Spearman's rho = 0.304 [p<0.001] for children) were positively correlated with PNP, suggesting a common source for the three analytes, presumably methyl parathion or related environmental degradates. Although we found a modest correlation between the metabolites, our findings suggest that despite the prohibition, at least a portion (approximately 25% to 60%) of the PNP detected among farmers and children in Thailand may be attributed to exposure from continued methyl parathion use.

  8. Removal of chlorothalonil, methyl parathion and methamidophos from water by the Fenton reaction.

    PubMed

    Gutiérrez, R F; Santiesteban, A; Cruz-López, L; Bello-Mendoza, R

    2007-03-01

    The efficiency of a dark Fenton system (H2O2/Fe2+) to remove chlorothalonil from water, alone and in the presence of the organophosphorous pesticides methyl parathion and methamidophos, was evaluated. Here we show that the process is rapid and efficient. Nearly complete degradation of chlorothalonil and methyl parathion (98%) was observed in less than 10 min whereas methamidophos showed similar levels of efficiency only after 40 to 90 min. Formulating agents did not appear to impair the degradation of active ingredients. Interactions during the degradation of mixtures of the three pesticides only appeared to affect methamidophos degradation.

  9. Electrochemical fabrication of molecularly imprinted porous silicate film electrode for fast and selective response of methyl parathion.

    PubMed

    Tan, Xiaohong; Li, Buhai; Liew, Kongyong; Li, Chunya

    2010-10-15

    A methyl parathion-templated molecularly imprinted porous silicate thin film was electrodeposited onto a glassy carbon electrode using tetraethylorthosilicate sol as the silicon precursor and vinyltriethoxysilane as the functional monomer. The surface morphology and crystallinity of the imprinted film were characterized by scanning electron microscope and X-ray diffraction. The binding performance of the film with methyl parathion was examined with voltammetric techniques. The results show that the imprinted sol-gel film gives fast, sensitive and selective response to methyl parathion. The good selectivity of the film allows fine discriminations of methyl parathion from interferants, which including parathion, α-hydroxyl-4-nitrophenyl-dimethyl-phosphonate, p-nitrophenol and nitrobenzene. A linear range for methyl parathion determination was found from 1.0×10(-8) to 1.0×10(-5) mol l(-1) with an estimated detection limit of 8.9×10(-9) mol l(-1) (S/N=3). This imprinted sol-gel film electrode was proved to be a versatile sensing tool for the selective detection of methyl parathion in real samples.

  10. Purification and characterization of three parathion hydrolases from gram-negative bacterial strains.

    PubMed

    Mulbry, W W; Karns, J S

    1989-02-01

    Three unique parathion hydrolases were purified from gram-negative bacterial isolates and characterized. All three purified enzymes had roughly comparable affinities for ethyl parathion and had broad temperature optima at ca. 40 degrees C. The membrane-bound hydrolase of Flavobacterium sp. strain ATCC 27551 was composed of a single subunit of approximately 35,000 daltons (Da) and was inhibited by sulfhydryl reagents such as dithiothreitol (DTT) and by metal salts such as CuCl2. The cytosolic hydrolase of strain B-1 was composed of a single subunit of approximately 43,000 Da and was stimulated by DTT and inhibited by CuCl2. The membrane-bound hydrolase of strain SC was composed of four identical subunits of 67,000 Da and was inhibited by DTT and stimulated by CuCl2. The substrate ranges of the three enzymes also differed, as evidenced by their relative affinities for parathion and the related organophosphate insecticide O-ethyl-O-4-nitrophenyl phenylphosphonothioate (EPN). The B-1 hydrolase displayed equal affinity for both compounds, the Flavobacterium enzyme showed twofold-lower affinity for EPN than for parathion, and the SC hydrolase displayed no activity toward EPN. The range in characteristics of these three enzymes can be exploited in different waste disposal strategies.

  11. Purification and characterization of three parathion hydrolases from gram-negative bacterial strains.

    PubMed Central

    Mulbry, W W; Karns, J S

    1989-01-01

    Three unique parathion hydrolases were purified from gram-negative bacterial isolates and characterized. All three purified enzymes had roughly comparable affinities for ethyl parathion and had broad temperature optima at ca. 40 degrees C. The membrane-bound hydrolase of Flavobacterium sp. strain ATCC 27551 was composed of a single subunit of approximately 35,000 daltons (Da) and was inhibited by sulfhydryl reagents such as dithiothreitol (DTT) and by metal salts such as CuCl2. The cytosolic hydrolase of strain B-1 was composed of a single subunit of approximately 43,000 Da and was stimulated by DTT and inhibited by CuCl2. The membrane-bound hydrolase of strain SC was composed of four identical subunits of 67,000 Da and was inhibited by DTT and stimulated by CuCl2. The substrate ranges of the three enzymes also differed, as evidenced by their relative affinities for parathion and the related organophosphate insecticide O-ethyl-O-4-nitrophenyl phenylphosphonothioate (EPN). The B-1 hydrolase displayed equal affinity for both compounds, the Flavobacterium enzyme showed twofold-lower affinity for EPN than for parathion, and the SC hydrolase displayed no activity toward EPN. The range in characteristics of these three enzymes can be exploited in different waste disposal strategies. Images PMID:2541658

  12. Metal organic frameworks (MOFs) for degradation of nerve agent simulant parathion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parathion, a simulant of nerve agent VX, has been studied for degradation on Fe3+, Fe2+ and zerovalent iron supported on chitosan. Chitosan, a naturally occurring biopolymer derivative of chitin, is a very good adsorbent for many chemicals including metals. Chitosan is used as supporting biopolymer ...

  13. Metal organic frameworks (MOFs) for degrdation of nerve agent simulant parathion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parathion, a simulant of nerve agent VX, has been studied for degradation on Fe3+, Fe2+ and zerovalent iron supported on chitosan. Chitosan, a naturally occurring biopolymer derivative of chitin, is a very good adsorbent for many chemicals including metals. Chitosan is used as supporting biopolymer ...

  14. Microbial biosensor for detection of methyl parathion using screen printed carbon electrode and cyclic voltammetry.

    PubMed

    Kumar, Jitendra; D'Souza, S F

    2011-07-15

    Whole cells of recombinant Escherichia coli were immobilized on the screen printed carbon electrode (SPCE) using glutaraldehyde. Recombinant E. coli was having high periplasmic expression of organophosphorus hydrolase enzyme, which hydrolyzes the methyl parathion into two products, p-nitrophenol and dimethyl thiophosphoric acid. Cells immobilized SPCE was studied under SEM. Cells immobilized SPCE was associated with cyclic voltammetry and cyclic voltammograms were recorded before and after hydrolysis of methyl parathion. Detection was calibrated based on the relationship between the changes in the current observed at +0.1 V potential, because of redox behavior of the hydrolyzed product p-nitrophenol. As concentration of methyl parathion was increased the oxidation current also increased. Only 20 μl volume of the sample was required for analysis. Detection range of biosensor was calibrated between 2 and 80 μM of methyl parathion from the linear range of calibration plot. A single immobilized SPCE was reused for 32 reactions with retention of 80% of its initial enzyme activity.

  15. Electrochemical investigation of methyl parathion at gold-sodium dodecylbenzene sulfonate nanoparticles modified glassy carbon electrode.

    PubMed

    Li, Chunya; Wang, Zhengguo; Zhan, Guoqin

    2011-01-01

    A gold/sodium dodecylbenzene sulfonate nanoparticles modified glassy carbon electrode (nano-Au/SDBS/GCE) was electrochemically fabricated with a constant potential at -0.4V. The obtained nano-Au/SDBS/GCE was characterized with scanning electronic microscopy, X-ray photoelectron spectroscopy and electrochemical techniques. Electrochemical behaviors of methyl parathion at the nano-Au/SDBS/GCE were thoroughly investigated. Compared to the unmodified electrode, the peak current obviously increased and the oxidation peak potential negatively shifted. These changes indicated that the composite nanoparticles possess good electrocatalytic performance on the electrochemical reaction of methyl parathion. Experimental parameters such as deposition time, pH value and accumulation conditions were optimized. Under optimum conditions, the peak current corresponding to the oxidation of the hydroxylamine group was found in a good linear relationship with the methyl parathion concentration. In addition, a calibration curve with excellent linearity was obtained in the concentration range from 5.0×10(-7)molL(-1) to 1.0×10(-4)molL(-1) with an estimated detection limit of 8.6×10(-8)molL(-1) (S/N=3). The successful determination of methyl parathion in real samples demonstrated the usefulness and potential applications of this method.

  16. Removal of methyl parathion by cyanobacteria Microcystis novacekii under culture conditions.

    PubMed

    Fioravante, Isabela Araújo; Barbosa, Francisco Antônio Rodrigues; Augusti, Rodinei; Magalhães, Sérgia Maria Starling

    2010-06-01

    This study investigated the removal of methyl parathion by cyanobacteria Microcystis novacekii in culture conditions and evaluated toxicity in terms of EC(50) of the pesticide for the species. This is the first report on the removal and toxicity of methyl parathion for the species that is abundant and easily accessible in Brazilian lakes. The results have shown that Microcystis novacekii is capable of removing methyl parathion, an organophosphorus pesticide, from the culture medium with an extraction rate higher than 90%. Spontaneous degradation was not significant, which indicates a high efficiency level of biological removal. No metabolites of methyl parathion were detected in the culture medium at the concentration levels evaluated (0.10 to 2.00 mg/dm(3)). The mechanisms proposed to explain pesticide removal are bioaccumulation and mineralization. EC(50) for 72 h was 17.60 mg/dm(3), which is much higher than the usual concentrations in surface waters. This indicates that M. novacekii is highly tolerant of this pesticide and may represent an important bioremediation agent of contaminated environments.

  17. Effects of malathion, diazinon, and parathion on mallard embryo development and cholinesterase activity

    USGS Publications Warehouse

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

    1981-01-01

    The effects of external exposure of mallard (Anas platyrhynchos) eggs to malathion, diazinon, and parathion were examined using formulations and concentrations similar to field applications. Treatment with aqueous emulsion simulated exposure at the rate of 100 gal per acre (153 liters/hectare) with three to six different doses per compound with treatment at 3 and 8 days of embryonic development. Treatment with a nontoxic oil vehicle simulated exposure at the rate of 11 gal per acre (16.8 liters/hectare) with three to six different doses per compound. The order of embryotoxicity on a pounds-per-acre basis was parathion > diazinon > malathion with either vehicle. However, the potential hazard under conditions of up to five times the maximum field level of application was greater for malathion because of the high permissible level of application for malathion on certain crops. Parathion, the most embryotoxic of the three, had the most pronounced effects when an oil vehicle was used, as reflected by an LC50 of about 2 lb of active ingredient per acre, stunted growth, and a high frequency of malformations involving distortion of the axial skeleton, particularly in the cervical region. All three compounds resulted in significant depression of plasma and brain cholinesterase activity, but parathion caused the most depression throughout development, which was still apparent in hatchlings. Treatment with either distilled water or oil vehicle alone did not result in any of these effects seen with organophosphorous insecticides.

  18. 75 FR 78243 - Propionic Acid and Salts, Urea Sulfate, Methidathion, and Methyl Parathion; Registration Review...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-15

    ... AGENCY Propionic Acid and Salts, Urea Sulfate, Methidathion, and Methyl Parathion; Registration Review... pesticides propionic acid and salts, case no. 4078, urea sulfate, case no. 7213, methidathion, case no. 0034... pesticides in the table below--propionic acid and salts, case 4078, urea sulfate, case no. 7213,...

  19. Children's exposure to chlorpyrifos and parathion in an agricultural community in central Washington State.

    PubMed Central

    Fenske, Richard A; Lu, Chensheng; Barr, Dana; Needham, Larry

    2002-01-01

    We measured two diethyl organophosphorus (OP) pesticides--chlorpyrifos and parathion--in residences, and their metabolic by-products, in the urine of children 6 years old or younger in a central Washington State agricultural community. Exposures to two dimethyl OP pesticides (azinphos-methyl and phosmet) in this same population have been reported previously. We categorized children by parental occupation and by household proximity to pesticide-treated farmland. Median chlorpyrifos house dust concentrations were highest for the 49 applicator homes (0.4 microg/g), followed by the 12 farm-worker homes (0.3 microg/g) and the 14 nonagricultural reference homes (0.1 microg/g), and were statistically different (p < 0.001); we observed a similar pattern for parathion in house dust. Chlorpyrifos was measurable in the house dust of all homes, whereas we found parathion in only 41% of the homes. Twenty-four percent of the urine samples from study children had measurable 3,5,6-trichloro-2-pyridinol (TCPy) concentrations [limits of quantitation (LOQ) = 8 microg/L], and 7% had measurable 4-nitrophenol concentrations (LOQ = 9 microg/L). Child urinary metabolite concentrations did not differ across parental occupational classifications. Homes in close proximity (200 ft/60 m) to pesticide-treated farmland had higher chlorpyrifos (p = 0.01) and parathion (p = 0.014) house dust concentrations than did homes farther away, but this effect was not reflected in the urinary metabolite data. Use of OP pesticides in the garden was associated with an increase in TCPy concentrations in children's urine. Parathion concentrations in house dust decreased 10-fold from 1992 to 1995, consistent with the discontinued use of this product in the region in the early 1990s. PMID:12003762

  20. Mass spectrometric detection of CYP450 adducts following oxidative desulfuration of methyl parathion.

    PubMed

    Kyle, Patrick B; Smith, Stanley V; Baker, Rodney C; Kramer, Robert E

    2013-07-01

    Cytochrome P450 (CYP)-mediated desulfuration of methyl parathion results in mechanism-based inhibition of the enzyme. Although previous data suggest that reactive sulfur is released and binds to the apoprotein, the identities of neither the adduct(s) nor the affected amino acid(s) have been clearly determined. In this study, nanospray tandem mass spectroscopy was used to analyze peptide digests of CYP resolved by SDS-PAGE from liver microsomes of male rats following incubation in the absence or presence of methyl parathion. Oxidative desulfuration was confirmed by measurement of methyl paraoxon, and inhibition of specific CYP isozymes was determined by measurement of testosterone hydroxylation. Total CYP content was quantified spectrophotometrically. Incubation of microsomes with methyl parathion decreased CYP content by 58%. This effect was not associated with a comparable increase in absorbance at 420 nm, suggesting the displacement of heme from the apoprotein. Rates of testosterone 2β- and 6β-hydroxylation, respectively, were reduced to 8 and 2%, implicating CYP3A and CYP2C11 in the oxidative desulfuration of methyl parathion. Mass spectrometric analysis identified 96 amu adducts to cysteines 64 and 378 of CYP3A1. In addition, a peptide containing cysteine 433 that coordinates with heme was possibly modified as it was detected in control, but not methyl parathion samples. A comparison of rat CYP3A1 with human CYP3A4 suggests that cysteines 64 and 378 reside along the substrate channel, remote from the active site. Alteration of these residues might modulate substrate entry to the binding pocket of the enzyme.

  1. PC-FACS.

    PubMed

    Abernethy, Amy P

    2012-03-01

    PC-FACS (Fast Article Critical Summaries for Clinicians in Palliative Care), an electronic publication of the American Academy of Hospice and Palliative Medicine, provides palliative care clinicians with concise summaries of the most important findings from more than 50 medical and scientific journals. Each month, structured summaries and insightful commentaries on 6-10 articles help palliative care clinicians stay on top of the research that is critical to contemporary practice. PC-FACS is free to AAHPM members and members can earn up to 3 CME credits quarterly. Following are excerpts from recent issues, and comments from readers are welcomed at resources@aahpm.org.

  2. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2012-04-01

    PC-FACS (Fast Article Critical Summaries for Clinicians in Palliative Care), an electronic publication of the American Academy of Hospice and Palliative Medicine, provides palliative care clinicians with concise summaries of the most important findings from more than 50 medical and scientific journals. Each month, structured summaries and insightful commentaries on 6-10 articles help palliative care clinicians stay on top of the research that is critical to contemporary practice. PC-FACS is free to AAHPM members. Following are excerpts from recent issues, and comments from readers are welcomed at resources@aahpm.org.

  3. Oviposition and the plasma concentrations of LH, progesterone, and corticosterone in bobwhite quail (Colinus virginianus) fed parathion

    USGS Publications Warehouse

    Rattner, B.A.; Sileo, L.; Scanes, C.G.

    1982-01-01

    Bobwhite quail were fed concentrations of parathion (0,50, 100, 200 or 400 p.p.m.) for 10 days. Food intake, body weight change, brain acetylcholinesterase activity, egg production, and ovary weight were reduced in a dose-dependent manner. In a second experiment, birds were fed 0, 25 or 100 p.p.m. parathion or pair-fed control food to equate consumption in the 100 p.p.m. group. Egg production was not affected in birds fed 25 p.p.m. or in the pair-fed group, but the daily time of oviposition was more variable than in the control group. Cessation of egg production, inhibition of follicular development, and reduced plasma LH concentration were observed in birds fed 100 p.p.m. parathion. These findings indicate that exposure to parathion can impair reproduction, possibly by altering gonadotrophin secretion.

  4. The abiotic degradation of methyl parathion in anoxic sulfur-containing system mediated by natural organic matter.

    PubMed

    Liao, Xiaoping; Zhang, Caixiang; Wang, Yanxin; Tang, Mi

    2017-06-01

    Although the kinetics and transformation of methyl parathion have been investigated extensively, its abiotic degradation mechanism in anoxic sulfur-containing groundwater system is still not clear. In this work, the abiotic degradation of methyl parathion in anoxic sulfur-containing system mediated by natural organic matter (NOM) was investigated in batch experiments. It was found that the removal of methyl parathion (up to 80.7%) was greatly improved in sulfide containing NOM compared to those in sulfide alone (with 15.5%) and in NOM alone (almost negligible). Various sulfur species presented significant differences in behaviors methyl parathion degradation, but followed by the pseudo-first-order model well. No facilitated degradation of methyl parathion was observed in sulfite (SO3(2-)) or thiosulfate (S2O3(2-)) containing NOM such as anthraquinone. Although elemental sulfur (S(0)) and cysteine could further improve the degradation rate of methyl parahtion, their impacts was very limited. The removal efficiency of methyl parathion in anoxic sulfur-containing system were related remarkably with NOM concentration and solution pH. Based on the transformation products identified by gas chromatography-mass spectrometer (GC/MS) and liquid chromatography high resolution mass spectrometer (LC/HRMS), both the nitro group reduction and hydrolysis (SN@C) processes by sulfide (HS(-)) were further proved to be two predominant reaction mechanisms for the abiotic degradation of methyl parathion in anoxic sulfur-containing system. The results of this study help to understand the natural attenuation of methyl parathion under anoxic sulfide-containing groundwater system mediated by NOM.

  5. Differential pulse voltammetric determination of methyl parathion based on multiwalled carbon nanotubes-poly(acrylamide) nanocomposite film modified electrode.

    PubMed

    Zeng, Yanbo; Yu, Dajun; Yu, Yanyan; Zhou, Tianshu; Shi, Guoyue

    2012-05-30

    A sensitive electrochemical differential pulse voltammetry method was developed for detecting methyl parathion based on multiwalled carbon nanotubes-poly(acrylamide) (MWCNTs-PAAM) nanocomposite film modified glassy carbon electrode. The novel MWCNTs-PAAM nanocomposite, containing high content of amide groups, was synthesized by PAAM polymerizing at the vinyl group functionalized MWCNTs surface using free radical polymerization. The MWCNTs-PAAM nanocomposite was characterized by Fourier transform infrared spectroscopy, thermal gravimetric analysis and scanning electron microscopy. Electrochemical behavior and interference studies of MWCNTs-PAAM/GCE for methyl parathion were investigated. The experimental results demonstrated that the MWCNTs-PAAM/GCE exhibited a high adsorption and strong affinity toward methyl parathion compared with some metal ions and nitroaromatic compounds, which exist in environmental samples. The adsorbed amount of methyl parathion on the MWCNTs-PAAM/GCE approached the equilibrium value upon 5 min adsorption time. A linear calibration curve for methyl parathion was obtained in the concentration range from 5.0×10(-9) to 1.0×10(-5) mol L(-1), with a detection limit of 2.0×10(-9) mol L(-1). The MWCNTs-PAAM/GCE was proved to be a suitable sensing tool for the fast, sensitive and selective determination of methyl parathion in environmental water samples.

  6. Lichenase and coding sequences

    DOEpatents

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

    2000-08-15

    The present invention provides a fungal lichenase, i.e., an endo-1,3-1,4-.beta.-D-glucanohydrolase, its coding sequence, recombinant DNA molecules comprising the lichenase coding sequences, recombinant host cells and methods for producing same. The present lichenase is from Orpinomyces PC-2.

  7. Easy PC Astronomy

    NASA Astrophysics Data System (ADS)

    Duffett-Smith, Peter

    1996-11-01

    Easy PC Astronomy is the perfect book for everyone who wants to make easy and accurate astronomical calculations. The author supplies a simple but powerful script language called AstroScript on a disk, ready to use on any IBM PC-type computer. Equipped with this software, readers can compute complex but interesting astronomical results within minutes: from the time of moonrise or moonset anywhere in the world on any date, to the display of a lunar or solar eclipse on the computer screen--all within a few minutes of opening the book! The Sky Graphics feature of the software displays a detailed image of the sky as seen from any point on earth--at any time in the future or past--showing the constellations, planets, and a host of other features. Readers need no expert knowledge of astronomy, math or programming; the author provides full details of the calculations and formulas, which the reader can absorb or ignore as desired, and a comprehensive glossary of astronomical terms. Easy PC Astronomy is of immediate practical use to beginning and advanced amateur astronomers, students at all levels, science teachers, and research astronomers. Peter Duffett-Smith is at the Cavendish Laboratory of the University of Cambridge and is the author of Astronomy with Your Personal Computer (Cambridge University Press, 1990) and Practical Astronomy with Your Calculator (Cambridge University Press, 1989).

  8. Ethyl parathion in wetlands following aerial application to sunflowers in North Dakota

    USGS Publications Warehouse

    Tome, M.W.; Grue, C.E.; DeWeese, L.R.

    1991-01-01

    An operational aerial application of parathion to sunflower fields resulted in greater or equal spray deposit in wetlands adjacent to or surrounded by sunflower fields than in the sunflower fields. In another application, when the applicator attempted to avoid contamination of the wetlands, parathion still drifted into wetlands in detectable amounts; in 2 of 4 comparisons, spray deposit in wetlands and sunflower fields did not differ. Weather during both spray operations was ideal for North Dakota, Le., wind speeds <16 km/ hour, excellent visibility, and temperature <24 C. We review how spray droplet size, weather, terrain, and type of application equipment interact to determine the amount of drift from any application of pesticide. With this information, wildlife managers should be able to make decisions pertaining to insecticide applications that will minimize drift and reduce negative impacts to nontarget organisms

  9. Quantitative NIR-Raman analysis of methyl-parathion pesticide microdroplets on aluminum substrates.

    PubMed

    Sato-Berrú, R Ysacc; Medina-Valtierra, Jorge; Medina-Gutiérrez, Cirilo; Frausto-Reyes, Claudio

    2004-08-01

    The potential of Raman spectroscopy in the quantitative analysis of dilute organic contaminants on aluminum substrates is evidenced in this work. Methyl-parathion microdroplets, an organophosphorus pesticide, has been used as a probe for this purpose. The samples were analyzed on an aluminum foil, which is very easy to acquire and to adapt. Moreover, aluminum foil does not need a previous treatment. Linear and no-linear curves as a function of the concentration of methyl-parathion versus the Raman intensity of the 1345 and 1110 cm(-1) peaks were established by means of a simple mathematical expression. A comparison with calibration curves fits very well, allowing quantification at concentration levels as low as parts per million.

  10. Physical comparison of parathion hydrolase plasmids from Pseudomonas diminuta and Flavobacterium sp.

    PubMed

    Mulbry, W W; Kearney, P C; Nelson, J O; Karns, J S

    1987-09-01

    Restriction maps of two plasmids encoding parathion hydrolase have been determined. pPDL2 is a 39-kb plasmid harbored by Flavobacterium sp. (ATCC 27551), while pCMS1 is a 70-kb plasmid found in Pseudomonas diminuta (strain MG). Both plasmids previously have been shown to share homologous parathion hydrolase genes (termed opd for organophosphate degradation) as judged by DNA-DNA hybridization and restriction mapping. In the present study, we conducted DNA hybridization experiments using each of nine PstI restriction fragments from pCMS1 as probes against Flavobacterium plasmid DNA. The opd genes of both plasmids are located within a highly conserved region of approximately 5.1 kb. This region of homology extends approximately 2.6 kb upstream and 1.7 kb downstream from the opd genes. No homology between the two plasmids is evident outside of this region.

  11. Photolytic degradation of methyl-parathion and fenitrothion in ice and water: implications for cold environments.

    PubMed

    Weber, Jan; Kurková, Romana; Klánová, Jana; Klán, Petr; Halsall, Crispin J

    2009-12-01

    Here we investigate the photodegradation of structurally similar organophosphorus pesticides; methyl-parathion and fenitrothion in water (20 degrees C) and ice (-15 degrees C) under environmentally-relevant conditions with the aim of comparing these laboratory findings to limited field observations. Both compounds were found to be photolyzed more efficiently in ice than in aqueous solutions, with quantum yields of degradation being higher in ice than in water (fenitrothion > methyl-parathion). This rather surprising observation was attributed to the concentration effect caused by freezing the aqueous solutions. The major phototransformation products included the corresponding oxons (methyl-paraoxon and fenitroxon) and the nitrophenols (3-methyl-nitrophenol and nitrophenol) in both irradiated water and ice samples. The presence of oxons in ice following irradiation, demonstrates an additional formation mechanism of these toxicologically relevant compounds in cold environments, although further photodegradation of oxons in ice indicates that photochemistry of OPs might be an environmentally important sink in cold environments.

  12. The Effect of Parathion on Red Blood Cell Acetylcholinesterase in the Wistar Rat

    PubMed Central

    Bunya, Naofumi; Sawamoto, Keigo; Benoit, Hanif

    2016-01-01

    Organophosphorus (OP) pesticide poisoning is a significant problem worldwide. Research into new antidotes for these acetylcholinesterase inhibitors, and even optimal doses for current therapies, is hindered by a lack of standardized animal models. In this study, we sought to characterize the effects of the OP pesticide parathion on acetylcholinesterase in a Wistar rat model that included comprehensive medical care. Methods. Male Wistar rats were intubated and mechanically ventilated and then poisoned with between 20 mg/kg and 60 mg/kg of intravenous parathion. Upon developing signs of poisoning, the rats were treated with standard critical care, including atropine, pralidoxime chloride, and midazolam, for up to 48 hours. Acetylcholinesterase activity was determined serially for up to 8 days after poisoning. Results. At all doses of parathion, maximal depression of acetylcholinesterase occurred at 3 hours after poisoning. Acetylcholinesterase recovered to nearly 50% of baseline activity by day 4 in the 20 mg/kg cohort and by day 5 in the 40 and 60 mg/kg cohorts. At day 8, most rats' acetylcholinesterase had recovered to roughly 70% of baseline. These data should be useful in developing rodent models of acute OP pesticide poisoning. PMID:27418928

  13. Methyl parathion and fenvalerate toxicity in American kestrels: Acute physiological responses and effects of cold

    USGS Publications Warehouse

    Rattner, B.A.; Franson, J.C.

    1984-01-01

    Physiological and toxicological effects of p.o. methyl parathion (0.375-3.0 mg/kg) or fenvalerate (1000-4000 mg/kg) were examined over a 10-h period in American kestrels (Falco sparverius) maintained in thermoneutral (22?C) and cold (-5?C) environments. Methyl parathion was highly toxic (estimated median lethal dose of 3.08 mg/kg, 95% confidence limits of 2.29 -4.14 mg/kg), producing dose-dependent inhibition of brain and plasma cholinesterase activity, hyperglycemia, and elevated plasma corticosterone concentration. Brain and plasma cholinesterase inhibition in excess of 50% was associated with transient but pronounced hypothermia 2 h after intubation, although the magnitude of this response was yariable. Fenvalerate, at doses far exceeding those encountered in the environment, caused mild intoxication and elevated plasma alanine aminotransferase activity. Cold intensified methyl parathion toxicity, but did not affect that of fenvalerate. Thus, it would appear that organophosphorus insecticides pose far greater hazard than pyrethroids to raptorial birds.

  14. The effect of methyl parathion on susceptibility of bobwhite quail (Colinus virginianus) to domestic cat predation.

    PubMed

    Galindo, J C; Kendall, R J; Driver, C J; Lacher, T E

    1985-01-01

    Bobwhite quail (Colinus virginianus) that received either 0, 2, 4, or 8 mg/kg methyl parathion (O,O-dimethyl o-p-nitrophenyl phosphorothioate) treatment were investigated as to their susceptibility to predation by a cat (Felis domesticus) predator. Four hours after receiving methyl parathion (MP), physical activity levels were monitored in quail and included the number of seconds spent still, walking, running, or flying before and after a cat was introduced into an experimental arena. The cholinesterase (ChE) activity for each quail on experiment was determined. Quail that were captured exhibited significantly greater inhibition of brain ChE activity and spent significantly more time being still than noncaptured birds. Birds receiving MP at 8 mg/kg spent more seconds being still than those in other treatment groups and had ChE activity reduced to 42.8% of normal activity. There was a tendency for quail at increasing treatment levels to be more susceptible to capture by the cat predator. The neurological and behavioral effects of methyl parathion may have important ecological ramifications.

  15. Aminoparathion: a highly reactive metabolite of parathion. 1. Reactions with polyphenols and polyphenol oxidase.

    PubMed

    Rung, Bruno; Schwack, Wolfgang

    2005-11-16

    Spiking of tomato and apple fruits with parathion at different levels of about 1-4 mg/kg irradiation and under simulated sunlight conditions resulted in nearly complete photodegradation within 13 h, but extractable parathion degradation products could not be found in any case. However, after irradiation of an unrealistically spiked apple (134 mg/kg) different photoproducts including aminoparathion (AP) were detectable by HPLC, proving that the hitherto postulated photochemistry of parathion indeed takes place in the fruit cuticle environment. Besides the photoreduction pathway it was shown for the first time that AP is also easily formed by reduction of the primary photoproduct nitrosoparathion with thiols (cysteine, glutathione), while ascorbic acid only leaves hydroxylaminoparathion. In the presence of polyphenols, AP was effectively bound to quinone intermediates formed by both silver oxide and polyphenol oxidases. For pyrocatechol, a disubstituted o-quinone derivative could be isolated as a dark red addition product and structurally be elucidated. However, in the presence of caffeic acid, catechol, naringin, and quercetin, respectively, insoluble dark colored polymers precipitated within 48 h, while in the supernatants AP was not detectable any more. Polymer-bound and nonextractable AP was proven by transesterification with sodium ethoxide releasing O,O,O-triethyl thiophosphate which was determined by GC. Additionally, AP itself was a substrate for polyphenol oxidases, resulting in a quinone imine intermediate which in turn reacted with excessive AP yielding deep red colored di- and trimerization products.

  16. Graphene quantum dot modified screen printed immunosensor for the determination of parathion.

    PubMed

    Mehta, Jyotsana; Bhardwaj, Neha; Bhardwaj, Sanjeev K; Tuteja, Satish K; Vinayak, Priya; Paul, A K; Kim, Ki-Hyun; Deep, Akash

    2017-02-02

    The widespread use of pesticides has immense effect on increased crop productions. However, they are also responsible for posing detrimental health hazards and/or for contaminating the environment with chemical residues. A routine and an on-field detection of pesticide residues in different food, water, and soil samples has become a need of the hour for which biosensors can offer a viable alternative. The present work reports a functionalized graphene quantum dot (GQD) based screen printed electrochemical immunosensor for the detection of parathion. The application of GQDs has permitted the realization of a sensitive, robust, and reproducible sensor unlike those carried out earlier for the similar purposes. This immunosensor exhibited a dynamic linear response for parathion within the range of 0.01-10(6) ng/L with a very low detection limit of 46 pg/L. According to the analysis of potential interferences, the proposed sensor was specifically detecting parathion even in the presence of its metabolite, paraoxon. The investigations of the proposed sensing approach with respect to stability, response reproducibility, and regeneration have fully supported its potential practical applicability.

  17. Detection of parathion pesticide by quartz crystal microbalance functionalized with UV-activated antibodies.

    PubMed

    Funari, Riccardo; Della Ventura, Bartolomeo; Schiavo, Luigi; Esposito, Rosario; Altucci, Carlo; Velotta, Raffaele

    2013-07-02

    Photonic immobilization technique (PIT) has been used to develop an immunosensor for the detection of parathion. An antibody solution has been activated by breaking the disulfide bridge in the triad Trp/Cys-Cys through absorption of ultrashort UV laser pulses. The free thiol groups so produced interact with gold lamina making the antibody oriented upside, that is, with its variable parts exposed to the environment, thereby greatly increasing the detection efficiency. PIT has been applied to anchor polyclonal antiparathion antibodies to the gold electrode of a Quartz Crystal Microbalance (QCM) giving rise to very high detection sensitivity once the parathion is made heavier by complexion with BSA (bovine serum albumin), this latter step only required by the mass based transducer used in this case. The comparison of the sensor response with irradiated antibodies against different analytes shows that the high degree of antibody specificity is not affected by PIT nor is it by the complexion of parathion with BSA. These results pave the way to important applications in biosensing, since the widespread occurrence of the Trp/Cys-Cys residues triads in proteins make our procedure very general and effective to detect light analytes.

  18. Biodegradation of lindane, methyl parathion and carbofuran by various enriched bacterial isolates.

    PubMed

    Krishna, K Rama; Philip, Ligy

    2008-02-01

    In the present study, lindane (1,2,3,4,5,6-hexachlorocyclohexane), methyl parathion (O-dimethylO-(4-nitro-phenyl) phosphorothioate) and carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate) degradation potential of different enriched bacterial cultures were evaluated under various environmental conditions. Enriched cultures behaved differently with different pesticides. Degradation was more in a facultative anaerobic condition as compared to that in aerobic condition. A specific pesticide enriched culture showed maximum degradation of that pesticide irrespective of pesticides and environmental conditions. Lindane and endosulfan enriched cultures behaved almost similarly. Degradation of lindane by lindane enriched cultures was 75 +/- 3% in aerobic co-metabolic process whereas 78 +/- 5% of lindane degradation occurred in anaerobic co-metabolic process. Degradation of methyl parathion by methyl parathion enriched culture was 87 +/- 1% in facultative anaerobic condition. In almost all the cases, many intermediate metabolites were observed. However, many of these metabolites disappeared after 4-6 weeks of incubation. Mixed pesticide-enriched culture degraded all the three pesticides more effectively as compared to specific pesticide- enriched cultures. It can be inferred from the results that a bacterial consortium enriched with a mixture of all the possible pesticides that are present in the site seems to be a better option for the effective bioremediation of multi-pesticide contaminated site.

  19. Kinetic-spectrophotometric determination of methyl parathion in water and vegetable samples.

    PubMed

    Tiwari, Neetu; Asthana, Anupama; Upadhyay, Kanchan

    2013-01-15

    A new selective and sensitive kinetic method has been developed for spectrophotometric determination of methyl parathion based on its inhibitory effect on the redox reaction between bromate and hydrochloric acid. The decolorization of neutral red by the reaction product was used to monitor the reaction spectrophotometrically at 530 nm by measuring the change in absorbance at the fixed time of 5 min after the initiation of the reaction. The variables affecting the rate of the reaction were investigated. Under the selected experimental conditions methyl parathion was determined in the range of 0.025-0.3 μg mL(-1). Sandell's sensitivity and molar absorptivity for the system were found to be 0.0004 μg cm(-2) and 6.5×10(5) L mol(-1) cm(-1) respectively. The proposed method was applied for the determination of methyl parathion in different vegetable and water samples with satisfactory results. The results were compared with those obtained by GC-MS, very similar values were found by the two methods.

  20. Comparative Effects of Parathion and Chlorpyrifos on Endocannabinoid and Endocannabinoid-Like Lipid Metabolites in Rat Striatum

    PubMed Central

    Liu, Jing; Parsons, Loren; Pope, Carey

    2015-01-01

    Parathion and chlorpyrifos are organophosphorus insecticides (OPs) that elicit acute toxicity by inhibiting acetylcholinesterase (AChE). The endocannabinoids (eCBs, N-arachidonoylethanolamine, AEA; 2-arachidonoylglycerol, 2AG) are endogenous neuromodulators that regulate presynaptic neurotransmitter release in neurons throughout the central and peripheral nervous systems. While substantial information is known about the eCBs, less is known about a number of endocannabinoid-like metabolites (eCBLs, e.g., N-palmitoylethanolamine, PEA; N-oleoylethanolamine, OEA). We report the comparative effects of parathion and chlorpyrifos on AChE and enzymes responsible for inactivation of the eCBs, fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), and changes in the eCBs AEA and 2AG and eCBLs PEA and OEA, in rat striatum. Adult, male rats were treated with vehicle (peanut oil, 2 ml/kg, sc), parathion (27 mg/kg) or chlorpyrifos (280 mg/kg) 6-7 days after surgical implantation of microdialysis cannulae into the right striatum, followed by microdialysis two or four days later. Additional rats were similarly treated and sacrificed for evaluation of tissue levels of eCBs and eCBLs. Dialysates and tissue extracts were analyzed by LC-MS/MS. AChE and FAAH were extensively inhibited at both time-points (85-96%), while MAGL activity was significantly but lesser affected (37-62% inhibition) by parathion and chlorpyrifos. Signs of toxicity were noted only in parathion-treated rats. In general, chlorpyrifos increased eCB levels while parathion had no or lesser effects. Early changes in extracellular AEA, 2AG and PEA levels were significantly different between parathion and chlorpyrifos exposures. Differential changes in extracellular and/or tissue levels of eCBs and eCBLs could potentially influence a number of signaling pathways and contribute to selective neurological changes following acute OP intoxications. PMID:26215119

  1. Comparative effects of parathion and chlorpyrifos on endocannabinoid and endocannabinoid-like lipid metabolites in rat striatum.

    PubMed

    Liu, Jing; Parsons, Loren; Pope, Carey

    2015-09-01

    Parathion and chlorpyrifos are organophosphorus insecticides (OPs) that elicit acute toxicity by inhibiting acetylcholinesterase (AChE). The endocannabinoids (eCBs, N-arachidonoylethanolamine, AEA; 2-arachidonoylglycerol, 2AG) are endogenous neuromodulators that regulate presynaptic neurotransmitter release in neurons throughout the central and peripheral nervous systems. While substantial information is known about the eCBs, less is known about a number of endocannabinoid-like metabolites (eCBLs, e.g., N-palmitoylethanolamine, PEA; N-oleoylethanolamine, OEA). We report the comparative effects of parathion and chlorpyrifos on AChE and enzymes responsible for inactivation of the eCBs, fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), and changes in the eCBs AEA and 2AG and eCBLs PEA and OEA, in rat striatum. Adult, male rats were treated with vehicle (peanut oil, 2 ml/kg, sc), parathion (27 mg/kg) or chlorpyrifos (280 mg/kg) 6-7 days after surgical implantation of microdialysis cannulae into the right striatum, followed by microdialysis two or four days later. Additional rats were similarly treated and sacrificed for evaluation of tissue levels of eCBs and eCBLs. Dialysates and tissue extracts were analyzed by LC-MS/MS. AChE and FAAH were extensively inhibited at both time-points (85-96%), while MAGL activity was significantly but lesser affected (37-62% inhibition) by parathion and chlorpyrifos. Signs of toxicity were noted only in parathion-treated rats. In general, chlorpyrifos increased eCB levels while parathion had no or lesser effects. Early changes in extracellular AEA, 2AG and PEA levels were significantly different between parathion and chlorpyrifos exposures. Differential changes in extracellular and/or tissue levels of eCBs and eCBLs could potentially influence a number of signaling pathways and contribute to selective neurological changes following acute OP intoxications.

  2. Plasmid-borne catabolism of methyl parathion and p-nitrophenol in Pseudomonas sp. strain WBC-3.

    PubMed

    Liu, Hong; Zhang, Jun-Jie; Wang, Su-Jun; Zhang, Xian-En; Zhou, Ning-Yi

    2005-09-09

    Pseudomonas sp. strain WBC-3 utilises methyl parathion (MP) or p-nitrophenol (PNP) as the sole source of carbon, nitrogen, and energy. A plasmid designated pZWL0 of approximately 70 kb in this strain was found to be responsible for MP and PNP degradation. This was based on the fact that the plasmid-cured strains showed PNP- MP- phenotype and the PNP+ MP+ phenotype could be conjugally transferred. We have also cloned a 3.4-kb HindIII fragment which exhibited methyl parathion hydrolase activity, which revealed a methyl parathion hydrolase (mph) gene whose DNA sequence is 99.5% identical to the recently identified mpd gene from Plesiomonas sp. M6 [C. Zhongli, L. Shunpeng, F. Guoping, Isolation of methyl parathion-degrading strain M6 and cloning of the methyl parathion hydrolase gene, Appl. Environ. Microbiol. 67 (2001) 4922-4925]. The mph gene was functionally expressed in Escherichia coli and the relative activities of the enzyme against different substrates were determined. The sequence alignment and phylogenetic analysis suggested that MPH and MPD evolved independently from other well-studied organophosphate hydrolases and may be originated from class B beta-lactamase family. Subsequently obtained a 6.5-kb KpnI and BamHI fragment containing the above HindIII fragment revealed that the mph gene was physically located in a typical transposon.

  3. Covalent Coupling of Organophosphorus Hydrolase Loaded Quantum Dots to Carbon Nanotube/Au Nanocomposite for Enhanced Detection of Methyl Parathion

    SciTech Connect

    Du, Dan; Chen, Wenjuan; Zhang, Weiying; Liu, Deli; Li, Haibing; Lin, Yuehe

    2010-02-15

    An amperometric biosensor for highly selective and sensitive determination of methyl parathion (MP) was developed based on dual signal amplification: (1) a large amount of introduced enzyme on the electrode surface and (2) synergistic effects of nanoparticles towards enzymatic catalysis. The fabrication process includes (1) electrochemical deposition of gold nanoparticles by a multi-potential step technique at multiwalled carbon nanotube (MWCNT) film pre-cast on a glassy carbon electrode and (2) immobilization of methyl parathion degrading enzyme (MPDE) onto a modified electrode through CdTe quantum dots (CdTe QDs) covalent attachment. The introduced MWCNT and gold nanoparticles significantly increased the surface area and exhibited synergistic effects towards enzymatic catalysis. CdTe QDs are further used as carriers to load a large amount of enzyme. As a result of these two important enhancement factors, the proposed biosensor exhibited extremely sensitive, perfectly selective, and rapid response to methyl parathion in the absence of a mediator.

  4. PC index and magnetic substorms

    NASA Astrophysics Data System (ADS)

    Troshichev, Oleg; Janzhura, Alexander; Sormakov, Dmitry; Podorozhkina, Nataly

    PC index is regarded as a proxy of the solar wind energy that entered into the magnetosphere as distinct from the AL and Dst indices, which are regarded as characteristics of the energy that realize in the magnetosphere in form of substorm and magnetic storms. This conclusion is based on results of analysis of relationships between the polar cap magnetic activity (PC-index) and parameters of the solar wind, on the one hand, relationships between changes of PC and development of magnetospheric substorms (AL-index) and magnetic storms (Dst-index), on the other hand. This paper describes in detail the following main results which demonstrate a strong connection between the behavior of PC and development of magnetic disturbances in the auroral zone: (1) magnetic substorms are preceded by the РС index growth (isolated and extended substorms) or long period of stationary PC (postponed substorms), (2) the substorm sudden onsets are definitely related to such PC signatures as leap and reverse, which are indicative of sharp increase of the PC growth rate, (3) substorms generally start to develop when the PC index exceeds the threshold level ~ 1.5±0.5 mV/m, irrespective of the substorm growth phase duration and type of substorm, (4) linear dependency of AL values on PC is typical of all substorm events irrespective of type and intensity of substorm.

  5. Kinetic analyses of the microsomal biotransformation of the phosphorothioate insecticides chlorpyrifos and parathion.

    PubMed

    Sultatos, L G; Murphy, S D

    1983-01-01

    Chlorpyrifos [0,0-diethyl-0-(3,5,6-trichloro-2-pyridyl) phosphorothioate] was metabolized to chlorpyrifos oxon [0,0-diethyl-0-(3,5,6-trichloro-2-pyridyl) phosphate] and to 3,5,6-trichloro-2-pyridinol by mouse hepatic microsomes. Formation of both chlorpyrifos oxon and 3,5,6-trichloro-2-pyridinol required NADPH, and was inhibited by carbon monoxide. Kinetic analyses using direct linear plots determined the appKm's for formation of chlorpyrifos oxon and 3,5,6-trichloro-2-pyridinol to be 20.9 +/- 3.3 microM and 16.1 +/- 3.4 microM respectively, while the appVmax's for the same reactions were 3.9 +/- 0.2 nmols/100 mg liver/min and 8.1 +/- 0.3 nmols/100 mg liver/min respectively. Incubation of parathion [0,0-diethyl-0-(4-nitrophenyl) phosphorothioate] with mouse hepatic microsomes produced paraoxon [0,0-diethyl-0-(4-nitrophenyl) phosphate] and p-nitrophenol. The appKm's for the formation of paraoxon and p-nitrophenol were 29.6 +/- 4.2 microM and 26.5 +/- 3.8 microM respectively, with appVmax's of 5.8 +/- 0.6 nmols/100 mg liver/min and 6.7 +/- 0.5 nmols/100 mg liver/min, respectively. Incubation of both parathion and chlorpyrifos at various concentrations with mouse hepatic microsomes resulted in inhibition of production of paraoxon, p-nitrophenol, chlorpyrifos oxon, and 3,5,6-trichloro-2-pyridinol, which was characteristic of mixed type inhibition. This complex kinetic behavior could arise as a result of competitive interactions of parathion and chlorpyrifos with multiple forms of microsomal cytochrome P-450.

  6. Cholinesterase inhibition of birds inhabiting wheat fields treated with methyl parathion and toxaphene

    USGS Publications Warehouse

    Niethammer, K.R.; Baskett, T.S.

    1983-01-01

    Red-winged blackbirds (Agelaius phoeniceus) and dickcissels (Spiza americana) inhabiting wheat fields treated with 0.67 kg AI/ha methyl parathion and 1.35 kg AI/ha toxaphene showed brain cholinesterase (ChE) inhibition compared with birds inhabiting untreated fields. Maximum inhibition occurred about five days after insecticide application. ChE activities again approached normal 10 days after treatment. ChE inhibition for dickcissels and red-winged blackbirds differed significantly (p<0.05); maximum inhibition for the former species was 74%, and for the latter, 40%. These differences could not be explained by the diets of the two species, as they were similar.

  7. A receptor binding assay applied to monitoring the neurotoxicity of parathion to Peromyscus after oral exposure

    USGS Publications Warehouse

    Jett, D.A.; Eldefrawi, A.T.; Eldefrawi, M.E.

    1993-01-01

    Many naturally occurring toxins, as well as pesticides, metals, and other compounds that occur in our environment from anthropogenic activities, stimulate or antagonize neuro-receptors to produce acute and/or chronic toxicities. Recent advances in laboratory instrumentation and the availability of a variety of radiolabeled ligands and type-specific drugs for numerous receptors make it possible to easily screen large numbers of samples and detect changes in sensitivity and density of receptor types and subtypes. A receptor binding assay for examining the chronic dietary toxicity of parathion will be used as a model to describe the methodology.

  8. Wanted: A Solid, Reliable PC

    ERIC Educational Resources Information Center

    Goldsborough, Reid

    2004-01-01

    This article discusses PC reliability, one of the most pressing issues regarding computers. Nearly a quarter century after the introduction of the first IBM PC and the outset of the personal computer revolution, PCs have largely become commodities, with little differentiating one brand from another in terms of capability and performance. Most of…

  9. NASA PC software evaluation project

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Kuan, Julie C.

    1986-01-01

    The USL NASA PC software evaluation project is intended to provide a structured framework for facilitating the development of quality NASA PC software products. The project will assist NASA PC development staff to understand the characteristics and functions of NASA PC software products. Based on the results of the project teams' evaluations and recommendations, users can judge the reliability, usability, acceptability, maintainability and customizability of all the PC software products. The objective here is to provide initial, high-level specifications and guidelines for NASA PC software evaluation. The primary tasks to be addressed in this project are as follows: to gain a strong understanding of what software evaluation entails and how to organize a structured software evaluation process; to define a structured methodology for conducting the software evaluation process; to develop a set of PC software evaluation criteria and evaluation rating scales; and to conduct PC software evaluations in accordance with the identified methodology. Communication Packages, Network System Software, Graphics Support Software, Environment Management Software, General Utilities. This report represents one of the 72 attachment reports to the University of Southwestern Louisiana's Final Report on NASA Grant NGT-19-010-900. Accordingly, appropriate care should be taken in using this report out of context of the full Final Report.

  10. Sonocatalytic degradation of methyl parathion in the presence of nanometer and ordinary anatase titanium dioxide catalysts and comparison of their sonocatalytic abilities.

    PubMed

    Wang, Jun; Pan, Zhijun; Zhang, Zhaohong; Zhang, Xiangdong; Wen, Fuyu; Ma, Teng; Jiang, Yuefeng; Wang, Lei; Xu, Liang; Kang, Pingli

    2006-09-01

    The degradation of methyl parathion (O,O-dimethyl-O-(4-nitrophenyl)-phosphorothioate) using anatase titanium dioxide (TiO(2)) powder as heterogeneous sonocatalysts is reported. The influences of reaction parameters such as the species of TiO(2) sonocatalysts, methyl parathion concentrations, TiO(2) adding amount, pH, ultrasonic intensity, ultrasonic frequency and temperature have been investigated and the optimal conditions for eliminating methyl parathion have been identified. The efficiencies of sonocatalytic degradation in both nanometer and ordinary anatase systems are compared and the results indicate that the sonocatalytic activity of nanometer anatase TiO(2) powder is better than that of ordinary anatase TiO(2) powder. The primary degradation and the total mineralization of methyl parathion have been monitored by high performance liquid chromatography (HPLC) and UV-vis spectra, respectively. Methyl parathion got destroyed to some extent in both nanometer and ordinary anatase systems under ultrasonic irradiation. The kinetics for the degradation process of methyl parathion follows the first-order reaction. The degradation ratio of methyl parathion surpassed 90% within 50min in the optimal experiment conditions.

  11. Parathion hydrolase specified by the Flavobacterium opd gene: relationship between the gene and protein.

    PubMed Central

    Mulbry, W W; Karns, J S

    1989-01-01

    The sequence of a 1,693-base-pair plasmid DNA fragment from Flavobacterium sp. strain ATCC 27551 containing the parathion hydrolase gene (opd) was determined. Within this sequence, there is only one open reading frame large enough to encode the 35,000-dalton membrane-associated hydrolase protein purified from Flavobacterium extracts. Amino-terminal sequence analysis of the purified Flavobacterium hydrolase demonstrated that serine is the amino-terminal residue of the hydrolase protein. The amino-terminal serine corresponds to a TCG codon located 87 base pairs downstream of the presumptive ATG initiation codon in the nucleotide sequence. The amino acid composition of the purified protein agrees well with that predicted from the nucleotide sequence, using serine as the amino-terminal residue. These data suggest that the parathion hydrolase protein is processed at its amino terminus in Flavobacterium sp. Construction in Escherichia coli of a lacZ-opd gene fusion in which the first 33 amino-terminal residues of opd were replaced by the first 5 residues of lacZ resulted in the production of an active hydrolase identical in molecular mass to the hydrolase isolated from Flavobacterium sp. E. coli cells containing the lacZ-opd fusion showed higher levels of hydrolase activity than did cells containing the parent plasmid. Images PMID:2556372

  12. Parathion hydrolase specified by the Flavobacterium opd gene: relationship between the gene and protein.

    PubMed

    Mulbry, W W; Karns, J S

    1989-12-01

    The sequence of a 1,693-base-pair plasmid DNA fragment from Flavobacterium sp. strain ATCC 27551 containing the parathion hydrolase gene (opd) was determined. Within this sequence, there is only one open reading frame large enough to encode the 35,000-dalton membrane-associated hydrolase protein purified from Flavobacterium extracts. Amino-terminal sequence analysis of the purified Flavobacterium hydrolase demonstrated that serine is the amino-terminal residue of the hydrolase protein. The amino-terminal serine corresponds to a TCG codon located 87 base pairs downstream of the presumptive ATG initiation codon in the nucleotide sequence. The amino acid composition of the purified protein agrees well with that predicted from the nucleotide sequence, using serine as the amino-terminal residue. These data suggest that the parathion hydrolase protein is processed at its amino terminus in Flavobacterium sp. Construction in Escherichia coli of a lacZ-opd gene fusion in which the first 33 amino-terminal residues of opd were replaced by the first 5 residues of lacZ resulted in the production of an active hydrolase identical in molecular mass to the hydrolase isolated from Flavobacterium sp. E. coli cells containing the lacZ-opd fusion showed higher levels of hydrolase activity than did cells containing the parent plasmid.

  13. Altering the substrate specificity of methyl parathion hydrolase with directed evolution.

    PubMed

    Ng, Tee-Kheang; Gahan, Lawrence R; Schenk, Gerhard; Ollis, David L

    2015-05-01

    Many organophosphates (OPs) are used as pesticides in agriculture. They pose a severe health hazard due to their inhibitory effect on acetylcholinesterase. Therefore, detoxification of water and soil contaminated by OPs is important. Metalloenzymes such as methyl parathion hydrolase (MPH) from Pseudomonas sp. WBC-3 hold great promise as bioremediators as they are able to hydrolyze a wide range of OPs. MPH is highly efficient towards methyl parathion (1 × 10(6) s(-1) M(-1)), but its activity towards other OPs is more modest. Thus, site saturation mutagenesis (SSM) and DNA shuffling were performed to find mutants with improved activities on ethyl paraxon (6.1 × 10(3) s(-1) M(-1)). SSM was performed on nine residues lining the active site. Several mutants with modest activity enhancement towards ethyl paraoxon were isolated and used as templates for DNA shuffling. Ultimately, 14 multiple-site mutants with enhanced activity were isolated. One mutant, R2F3, exhibited a nearly 100-fold increase in the kcat/Km value for ethyl paraoxon (5.9 × 10(5) s(-1) M(-1)). These studies highlight the 'plasticity' of the MPH active site that facilitates the fine-tuning of its active site towards specific substrates with only minor changes required. MPH is thus an ideal candidate for the development of an enzyme-based bioremediation system.

  14. Photochemical nitro-nitrite rearrangement in methyl parathion decay under tropical conditions.

    PubMed

    Araújo, Thiago M R; Canela, Maria C; Miranda, Paulo C M L

    2013-01-01

    This work presents a study of the abiotic degradation of commercially available methyl parathion in aqueous solution at two different concentrations (88 mg/L and 200 μg/L). The effects of solar irradiation and the presence of humic acids were evaluated and revealed a synergistic response between them. The half-life of methyl parathion ranged from 4.9 to 37 days, and the experimental data also show that photochemical processes were the most relevant in this case. The only byproduct found in samples submitted to shadowed conditions was 4-nitrophenol. On the other hand, 4-nitrophenol, methyl paraoxon and a new degradation product (O,O-dimethyl O-p-hydroxyphenyl phosphorothioate) were detected when the samples were exposed directly to sunlight. This newly identified compound was prepared in the laboratory by thiophosphorylation of hydroquinone, and coelution experiments with authentic samples provided unambiguous confirmation of the presence of O,O-dimethyl O-p-hydroxy phenylphosphorothioate in samples.

  15. [Construction of a stable genetically engineered microorganism for degrading HCH & methyl parathion and its characteristics].

    PubMed

    Lu, Peng; Hong, Yuan-Fan; Hong, Qing; Jiang, Xin; Li, Shun-Peng

    2008-07-01

    A GEM designated as BHC-A-mpd, capable of simultaneously degrading of methyl parathion (MP) and HCH was successfully constructed by random insertion of a methyl parathion hydrolase gene (mpd) into chromosome of a HCH-degrading strain BHC-A with the mini-Tn-transposon system. The growth and degrading characteristics of BHC-A-mpd was compared with the original strain BHC-A, and the result showed that there was no difference in this two aspects, A600 nm of BHC-A-mpd in LB medium could reach 2.5 in logarithmic period, which was the same as that of the original strain BHC-A.BHC-A-mpd showed the same HCH-degrading ability as BHC-A and could degrade 5 mg/L of gamma-HCH in 10 h. BHC-A-mpd showed high genetica stability and could degrade many kinds of organophosphorus pesticides. All these results indicated that BHC-A-mpd was a promising GEM in bioremediation of MP and HCH co-contaminated environment.

  16. ABCB1 and ABCC4 efflux transporters are involved in methyl parathion detoxification in ZFL cells.

    PubMed

    Nornberg, Bruna Félix; Batista, Carolina Reyes; Almeida, Daniela Volcan; Trindade, Gilma Santos; Marins, Luis Fernando

    2015-02-01

    The multi-xenobiotics resistance (MXR) mechanisms are the first line of defense against toxic substances in aquatic organisms and present great importance in the adaptation related to contaminated environments. Methyl parathion (MP) is a widely used organophosphate pesticide, which has been associated to various toxic effects in organisms. In the present work, we studied the main genes related to efflux transporters in zebrafish liver (ZFL) cells exposed to MP with and without an inhibitor of ABC transporters (verapamil). The results concerning transporters activity showed that the MXR mechanism is activated to detoxify from methyl parathion. The toxic effects of MP on ZFL cells were increased in the presence of the efflux transporter inhibitor, once cell viability was significantly decreased in co-exposure experiments. The combined exposure to MP and the inhibitor caused an increase in gene expression of P-gp1 (Abcb1) and MRP4 (Abcc4), suggesting that these transporters isoforms are associated with MP efflux. In general, the expression of genes related to the antioxidant defense system (ADS) was significantly increased in ZFL cells co-exposed to MP and verapamil. These data provide useful insights for better understanding of MP detoxification mechanism in fish hepatocytes.

  17. Isolation of a selected microbial consortium capable of degrading methyl parathion and p-nitrophenol from a contaminated soil site.

    PubMed

    Pino, Nancy J; Dominguez, Maria C; Penuela, Gustavo A

    2011-01-01

    A bacterial consortium with the ability to degrade methyl parathion and p-nitrophenol, using these compounds as the only carbon source, was obtained by selective enrichment in a medium with methyl parathion. Samples were taken from Moravia, Medellin; an area that is highly contaminated, owing to the fact that it was used as a garbage dump from 1974 to 1982. Acinetobacter sp, Pseudomonas putida, Bacillus sp, Pseudomonas aeruginosa Citrobacter freundii, Stenotrophomonas sp, Flavobacterium sp, Proteus vulgaris, Pseudomonas sp, Acinetobacter sp, Klebsiella sp and Proteus sp were the microorganisms identified within the consortium. In culture, the consortium was able to degrade 150 mg L⁻¹ of methyl-parathion and p-nitrophenol in 120 h, but after adding glucose or peptone to the culture, the time of degradation decreased to 24 h. In soil, the consortium was also able to degrade 150 mg L⁻¹ of methyl parathion in 120 h at different depths and also managed to decrease the toxicity.

  18. The interaction of methyl-parathion with serum and albumin of the neo-tropical fish Piaractus mesopotamicus.

    PubMed

    Silva, Dilson; Cortez-Moreira, Madelayne; Cunha Bastos, Vera L F; Cunha Bastos, Jayme; Martins Cortez, Célia

    2010-01-01

    The interaction of methyl-parathion with serum and albumin of pacu, Piaractus mesopotamicus, was studied, using the fluorescence quenching technique. Pacu is a neo-tropical fish specie inhabitant of rivers from western regions of Brazil. Methyl-parathion (O,O-dimethyl O-p-nitrophenyl phosphorothioate) is an organophosphorous pesticide still used in agriculture and fish farming in many countries. The quenching of fluorescence can be mathematically expressed by the Stern-Volmer equation to calculate quenching constants. Stern-Volmer curves analysis is able to give important information about the pesticide-albumin interaction. Our results showed that the serum quenching reached 10% when the molar ratio of pesticide/albumin was about 7:1 for the three temperatures of the experiment. For the pure albumin quenching of 10%, methyl-parathion concentrations were 6, 7 and 9 times higher than albumin at 20, 25 and 30 degrees C, respectively. The calculated Stern-Volmer constants at 25 degrees C were 9.73x10(3)(+/-4.9x10(2))M(-1) for serum and 9.20x10(3)(+/-2.0x10(2))M(-1) for albumin. It was observed that albumin quenching is the phenomenon contributing to the quenching of the pacu serum fluorescence for methyl-parathion concentration lower than 10microM, suggesting that the protein is the most important carrier for the pesticide in serum.

  19. Multivariate optimization of molecularly imprinted polymer solid-phase extraction applied to parathion determination in different water samples.

    PubMed

    Alizadeh, Taher; Ganjali, Mohammad Reza; Nourozi, Parviz; Zare, Mashaalah

    2009-04-13

    In this work a parathion selective molecularly imprinted polymer was synthesized and applied as a high selective adsorber material for parathion extraction and determination in aqueous samples. The method was based on the sorption of parathion in the MIP according to simple batch procedure, followed by desorption by using methanol and measurement with square wave voltammetry. Plackett-Burman and Box-Behnken designs were used for optimizing the solid-phase extraction, in order to enhance the recovery percent and improve the pre-concentration factor. By using the screening design, the effect of six various factors on the extraction recovery was investigated. These factors were: pH, stirring rate (rpm), sample volume (V(1)), eluent volume (V(2)), organic solvent content of the sample (org%) and extraction time (t). The response surface design was carried out considering three main factors of (V(2)), (V(1)) and (org%) which were found to be main effects. The mathematical model for the recovery percent was obtained as a function of the mentioned main effects. Finally the main effects were adjusted according to the defined desirability function. It was found that the recovery percents more than 95% could be easily obtained by using the optimized method. By using the experimental conditions, obtained in the optimization step, the method allowed parathion selective determination in the linear dynamic range of 0.20-467.4 microg L(-1), with detection limit of 49.0 ng L(-1) and R.S.D. of 5.7% (n=5). Parathion content of water samples were successfully analyzed when evaluating potentialities of the developed procedure.

  20. Neonatal Exposure to Parathion Alters Lipid Metabolism in Adulthood: Interactions with Dietary Fat Intake and Implications for Neurodevelopmental Deficits

    PubMed Central

    Lassiter, T. Leon; Ryde, Ian T.; Levin, Edward D.; Seidler, Frederic J.; Slotkin, Theodore A.

    2009-01-01

    Organophosphates are developmental neurotoxicants but recent evidence also points to metabolic dysfunction. We determined whether neonatal parathion exposure in rats has long-term effects on regulation of adipokines and lipid peroxidation. We also assessed the interaction of these effects with increased fat intake. Rats were given parathion on postnatal days 1–4 using doses (0.1 or 0.2 mg/kg/day) that straddle the threshold for barely detectable cholinesterase inhibition and the first signs of systemic toxicity. In adulthood, animals were either maintained on standard chow or switched to a high-fat diet for seven weeks. We assessed serum leptin and adiponectin, tumor necrosis factor-α (TNFα) in adipose tissues, and thiobarbituric acid reactive species (TBARS) in peripheral tissues and brain regions. Neonatal parathion exposure uncoupled serum leptin levels from their dependence on body weight, suppressed adiponectin and elevated TNFα in white adipose tissue. Some of the effects were offset by a high-fat diet. Parathion reduced TBARS in the adipose tissues, skeletal muscle and temporal/occipital cortex but not in heart, liver, kidney or frontal/parietal cortex; it elevated TBARS in the cerebellum; the high-fat diet again reversed many of the effects. Neonatal parathion exposure disrupts the regulation of adipokines that communicate metabolic status between adipose tissues and the brain, while also evoking an inflammatory adipose response. Our results are consistent with impaired fat utilization and prediabetes, as well as exposing a potential relationship between effects on fat metabolism and on synaptic function in the brain. PMID:19615431

  1. Evaluation of the susceptibility of the cultured shrimp Litopenaeus vannamei to vibriosis when orally exposed to the insecticide methyl parathion.

    PubMed

    Roque, A; Abad, S; Betancourt-Lozano, M; de la Parra, L M Garcia; Baird, D; Guerra-Flores, A L; Gomez-Gil, B

    2005-06-01

    The causes of disease in cultured shrimp are difficult to ascertain but there is evidence that disease is correlated with environmental factors. Crustaceans are particularly sensitive to insecticides due to their close phylogenetic relationship with insects. The objective of this study was to investigate whether there was an increased susceptibility of the shrimp Litopenaeus vannamei to Vibrio parahaemolyticus, when exposed to methyl parathion. The outline of the study was the following: An LC50 96 h was determined to methyl parathion orally offered to juvenile shrimp. Further experiments were carried out in order to determine a concentration that affected the shrimp (verified by measuring the acethylcholinesterase activity) while producing minimal mortalities. This sublethal concentration was used in a susceptibility experiment where methyl parathion was offered to shrimp which were later injected with V. parahaemolyticus in a dose expected to kill less than 15%. Probit analysis estimated a 96 h median lethal concentration (LC50) of 1.56 microg g(-1). Mortality and AChE activity showed a concentration-response relationship in the exposure treatments. The median inhibitory concentration (IC50) determined was 0.029 microg g(-1). These results suggested that a concentration of 0.1 microg g(-1) was appropriate for the bacteria-pesticide interaction test as it was able to elicit 11.1% mortality after 10 days of exposure, while producing an AChE inhibition of 57.12%. Cumulative mortalities were significantly increased (P<0.01) in the treatment that combined exposure to methyl parathion and V. parahaemolyticus (35.19%) in comparison with methyl parathion or V. parahaemolyticus alone (9.26% and 7.41%, respectively).

  2. Study of Degradation Kinetics of Parathion Methyl On Mixed Nanocrystalline Titania-Zirconium and Titania-Cerium Oxides

    NASA Astrophysics Data System (ADS)

    Kuráň, Pavel; Pšenička, Martin; Šťastný, Martin; Benkocká, Monika; Janoš, Pavel

    2016-10-01

    The unique surface properties of some nanocrystalline metal oxides and their application for removal of various toxic compounds were reported in early 1990s. Recently, a reliable method for the preparation of reactive cerium dioxide sorbent and its application for degradation of the organophosphate pesticides, such as parathion methyl, chlorpyrifos, dichlofenthion, fenchlorphos, and prothiofos, as well as of some chemical warfare agents-nerve gases soman and O-ethyl S-[2-(diisopropylamino) ethyl] methylphosphonothioate (VX) was published. This paper reports on the kinetics study of degradation of parathion methyl as a representative organophosphate on nanocrystalline metal oxides TiO2, ZrO2, CeO2 and their mixtures in different molar ratios of particular elements. The tested sorbents except of CeO2 were prepared by different methods (e.g. sol-gel, precipitation) in cooperation with Institute of Inorganic Chemistry (Rez, Czech Republic). The degradation kinetics of parathion methyl on tested sorbents was followed by HPLC equipped with diode array detector. The basic kinetics parameters (half-lives of parathion methyl degradation, rate constants of degradation product formation) were calculated for each sorbent from Weber-Morris equation of 1st order diffusion kinetic model. The results proved the ability of prepared sorbents to degrade parathion methyl under formation of 4-nitrophenol as the main degradation product. The most efficient sorbents were TiCe (2:8), TiCe (1:1), TiCe (0:1) (50-70 %) followed by TiZr (1:1), TiCe (8:2), TiZr (8:2), TiZr (2:8) (20-30%) and TiO2, ZrO2 (less than 5 %).

  3. ELIPGRID-PC: A PC program for calculating hot spot probabilities

    SciTech Connect

    Davidson, J.R.

    1994-10-01

    ELIPGRID-PC, a new personal computer program has been developed to provide easy access to Singer`s 1972 ELIPGRID algorithm for hot-spot detection probabilities. Three features of the program are the ability to determine: (1) the grid size required for specified conditions, (2) the smallest hot spot that can be sampled with a given probability, and (3) the approximate grid size resulting from specified conditions and sampling cost. ELIPGRID-PC also provides probability of hit versus cost data for graphing with spread-sheets or graphics software. The program has been successfully tested using Singer`s published ELIPGRID results. An apparent error in the original ELIPGRID code has been uncovered and an appropriate modification incorporated into the new program.

  4. 75 FR 62002 - Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-07

    ... Limitations Section (ALS). For PC-6 models other than B2-H2 and B2- H4, no ALS at all is included in the AMM... and B2-H4 models. For PC-6 models other than B2-H2 and B2-H4, a new ALS document has been implemented... Limitations Section (ALS). For PC-6 models other than B2-H2 and B2- H4, no ALS at all is included in the...

  5. 76 FR 5467 - Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-01

    ... Limitations Section (ALS). For PC-6 models other than B2-H2 and B2- H4, no ALS at all is included in the AMM... and B2-H4 models. For PC-6 models other than B2-H2 and B2-H4, a new ALS document has been implemented... Limitations Section (ALS). For PC-6 models other than B2-H2 and B2- H4, no ALS at all is included in the...

  6. Pathway Controlled Penetration (PcP)

    SciTech Connect

    Knight, Earl E.; Rougier, Esteban; Zubelewicz, Aleksander

    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.

  7. Competition of a parathion-hydrolyzing Flavobacterium with bacteria from ditch water in carbon-, nitrate- and phosphate-limited continuous cultures.

    PubMed

    Sprenger, Wander W; Dijkstra, Annereinou; Zwart, Gabriel J M; Agterveld, Miranda P; Noort, Paul C M; Parsons, John R

    2003-02-01

    Abstract The effect of competition for macroelements with bacteria from ditch water on the parathion-hydrolyzing Flavobacterium sp. ATCC 27551 (FB) was investigated within mixed continuous cultures under carbon-, nitrate- or phosphate-limited conditions. The high initial rate of parathion hydrolysis decreased rapidly in all cultures due to the loss of strain FB. Addition of 2-isopropyl-6-methyl-4-pyrimidinol (a selective source of carbon, nitrogen and energy for FB) to one nitrate- and carbon-limited chemostat caused a 20-fold increase in parathion-hydrolyzing activity compared to unamended control cultures and retention of FB. The presence of the parathion hydrolase-encoding gene could be demonstrated by a newly developed PCR detection method in all FB cultures during most of the cultivation period. These results suggest that competition effects cause the pesticide-degrading capacity of microbial communities depending on their frequency of exposure to the pesticide compounds.

  8. Toxicity of parathion on embryo and yolk-sac larvae of gilthead seabream (Sparus aurata l.): effects on survival, cholinesterase, and carboxylesterase activity.

    PubMed

    Arufe, M Isabel; Arellano, Juana M; Albendín, Gemma; Sarasquete, Carmen

    2010-12-01

    This study was conducted to examine the acute toxicity of the organophosphorus pesticide (OP) parathion on embryos and yolk-sac larvae of gilthead seabream (Sparus aurata), and to investigate the effects of this compound on cholinesterase and carboxylesterase activity of seabream larvae in the phase of endogenous feeding. The 72-h LC50 for yolk-sac larvae (0.523 mg L⁻¹) was about two-fold lower than the 48-h LC50 for embryos (1.005 mg L⁻¹). Parathion significantly inhibited the activity of ChE and CaE activity in yolk sac larvae but there were not significant differences in the sensitivity of both esterases to parathion as inferred by their 72-h IC50 values. Larvae exposed to parathion for 72 h showed a 70% inhibition of the whole body acetylcholinesterase at approximately the LC50.

  9. Accelerating the initial rate of hydrolysis of methyl parathion with laser excitation using monolayer protected 10 nm Au nanoparticles capped with a Cu(bpy) catalyst.

    PubMed

    Trammell, Scott A; Nita, Rafaela; Moore, Martin; Zabetakis, Dan; Chang, Eddie; Knight, D Andrew

    2012-04-28

    Using a low power green laser, we have demonstrated a rate acceleration of ~2-fold for the hydrolysis of methyl parathion by irradiating the plasmon absorption band of Au nanoparticles capped with a Cu(bpy) catalyst.

  10. USL/DBMS NASA/PC R and D project C programming standards

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Moreau, Dennis R.

    1984-01-01

    A set of programming standards intended to promote reliability, readability, and portability of C programs written for PC research and development projects is established. These standards must be adhered to except where reasons for deviation are clearly identified and approved by the PC team. Any approved deviation from these standards must also be clearly documented in the pertinent source code.

  11. Human hepatic cytochrome P450-specific metabolism of the organophosphorus pesticides methyl parathion and diazinon.

    PubMed

    Ellison, Corie A; Tian, Yuan; Knaak, James B; Kostyniak, Paul J; Olson, James R

    2012-01-01

    Organophosphorus pesticides (OPs) are a public health concern due to their worldwide use and documented human exposures. Phosphorothioate OPs are metabolized by cytochrome P450s (P450s) through either a dearylation reaction to form an inactive metabolite, or through a desulfuration reaction to form an active oxon metabolite, which is a potent cholinesterase inhibitor. This study investigated the rate of desulfuration (activation) and dearylation (detoxification) of methyl parathion and diazinon in human liver microsomes. In addition, recombinant human P450s were used to determine the P450-specific kinetic parameters (K(m) and V(max)) for each compound for future use in refining human physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) models of OP exposure. The primary enzymes involved in bioactivation of methyl parathion were CYP2B6 (K(m) = 1.25 μM; V(max) = 9.78 nmol · min(-1) · nmol P450(-1)), CYP2C19 (K(m) = 1.03 μM; V(max) = 4.67 nmol · min(-1) · nmol P450(-1)), and CYP1A2 (K(m) = 1.96 μM; V(max) = 5.14 nmol · min(-1) · nmol P450(-1)), and the bioactivation of diazinon was mediated primarily by CYP1A1 (K(m) = 3.05 μM; V(max) = 2.35 nmol · min(-1) · nmol P450(-1)), CYP2C19 (K(m) = 7.74 μM; V(max) = 4.14 nmol · min(-1) · nmol P450(-1)), and CYP2B6 (K(m) = 14.83 μM; V(max) = 5.44 nmol · min(-1) · nmol P450(-1)). P450-mediated detoxification of methyl parathion only occurred to a limited extent with CYP1A2 (K(m) = 16.8 μM; V(max) = 1.38 nmol · min(-1) · nmol P450(-1)) and 3A4 (K(m) = 104 μM; V(max) = 5.15 nmol · min(-1) · nmol P450(-1)), whereas the major enzyme involved in diazinon detoxification was CYP2C19 (K(m) = 5.04 μM; V(max) = 5.58 nmol · min(-1) · nmol P450(-1)). The OP- and P450-specific kinetic values will be helpful for future use in refining human PBPK/PD models of OP exposure.

  12. Evaluation of sublethal biomarkers in Litopenaeus vannamei on foodborne exposure to methyl parathion.

    PubMed

    Comoglio, L; Amin, O; Roque, A; Betancourt-Lozano, M; Anguas, D; Haro, B M

    2005-09-01

    Sublethal effects of foodborne exposure to methyl parathion (0.62 and 1.31 microg methyl parathion*g(-1) dry weight of food) on juveniles of Litopenaeus vannamei using integrated biochemical (acetylcholinesterase (AChE) and ATPases) and physiological (feeding rate (FR), egestion rate (ER), and hepatosomatic index (HI)) biomarkers were evaluated. The HI was significantly higher in controls than in pesticide treatments. The FR was significantly lower in controls than in pesticide treatments while no significant differences were detected in the ER. AChE activity was significantly higher in controls than in pesticide treatments (control = 0.11 +/- 0.02; solvent control = 0.11 +/- 0.03; 0.62 = 0.07 +/- 0.01; 1.31 = 0.08 +/- 0.02 microM*min(-1)*mgprotein(-1)). The total-ATPase activity was significantly lower in controls than in pesticide treatments (control=77.90+/-12.41; solvent control = 83.69 +/- 22.05; 0.62 = 110.03 +/- 22.17; 1.31 = 121.54 +/- 19.84 microM P(i)*h(-1)*mgprotein(-1)). The Mg(2+)-ATPase activity was significantly higher in treatments than in controls (control = 65.14+/-10.76; solvent control = 75.12 +/- 21.10; 0.62 = 100.53 +/- 20.97; 1.31 = 108.94 +/- 17.26 microM P(i)*h(-1)*mgprotein(-1)). Finally, the results obtained for the Na(+)/K(+)-ATPase activity were significantly higher in control and in 1.31 than in solvent control and in 0.62 (control = 14.06+/-2.63; solvent control=7.30 +/- 4.13; 0.62 = 7.60 +/- 3.81; 1.31 = 13.42 +/- 2.88 microM P(i)*h(-1)*mgprotein(-1)). The results in this study showed that pulse exposures to methyl parathion via food could elicit measurable effects on the marine shrimp L. vannamei, indicating that foodborne exposure can be a reliable toxicological procedure and, if combined with pulse exposures, could also simulate more realistic exposure scenarios.

  13. Human Hepatic Cytochrome P450-Specific Metabolism of the Organophosphorus Pesticides Methyl Parathion and Diazinon

    PubMed Central

    Tian, Yuan; Knaak, James B.; Kostyniak, Paul J.; Olson, James R.

    2012-01-01

    Organophosphorus pesticides (OPs) are a public health concern due to their worldwide use and documented human exposures. Phosphorothioate OPs are metabolized by cytochrome P450s (P450s) through either a dearylation reaction to form an inactive metabolite, or through a desulfuration reaction to form an active oxon metabolite, which is a potent cholinesterase inhibitor. This study investigated the rate of desulfuration (activation) and dearylation (detoxification) of methyl parathion and diazinon in human liver microsomes. In addition, recombinant human P450s were used to determine the P450-specific kinetic parameters (Km and Vmax) for each compound for future use in refining human physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) models of OP exposure. The primary enzymes involved in bioactivation of methyl parathion were CYP2B6 (Km = 1.25 μM; Vmax = 9.78 nmol · min−1 · nmol P450−1), CYP2C19 (Km = 1.03 μM; Vmax = 4.67 nmol · min−1 · nmol P450−1), and CYP1A2 (Km = 1.96 μM; Vmax = 5.14 nmol · min−1 · nmol P450−1), and the bioactivation of diazinon was mediated primarily by CYP1A1 (Km = 3.05 μM; Vmax = 2.35 nmol · min−1 · nmol P450−1), CYP2C19 (Km = 7.74 μM; Vmax = 4.14 nmol · min−1 · nmol P450−1), and CYP2B6 (Km = 14.83 μM; Vmax = 5.44 nmol · min−1 · nmol P450−1). P450-mediated detoxification of methyl parathion only occurred to a limited extent with CYP1A2 (Km = 16.8 μM; Vmax = 1.38 nmol · min−1 · nmol P450−1) and 3A4 (Km = 104 μM; Vmax = 5.15 nmol · min−1 · nmol P450−1), whereas the major enzyme involved in diazinon detoxification was CYP2C19 (Km = 5.04 μM; Vmax = 5.58 nmol · min−1 · nmol P450−1). The OP- and P450-specific kinetic values will be helpful for future use in refining human PBPK/PD models of OP exposure. PMID:21969518

  14. Studies on combined effects of organophosphates and heavy metals in birds. I. Plasma and brain cholinesterase in Coturnix quail fed methyl mercury and orally dosed with parathion

    USGS Publications Warehouse

    Dieter, M.P.; Ludke, J.L.

    1975-01-01

    We found that mercury potentiated the toxicity and biochemical effects of parathion. Male Coturnix quail (Coturnix coturnix japonica) were fed a sublethal concentration of morsodren (4 ppm as methyl mercury) for 18 weeks. This resulted in an accumulation of 21.0 ppm of mercury in the liver and 8.4 ppm in the carcass. Birds fed clean feed and those fed morsodren-treated feed were orally dosed with 2, 4, 6, 8,and 10 mg/kg parathion, and their 48-h survival times compared. The computed LD50 was 5.86mg/kg in birds not fed morsodren and 4.24 in those fed the heavy metal. When challenged with a sublethal, oral dose of parathion (1.0 mg/kg), morsodren-fed birds exhibited significantly greater inhibition of plasma and brain cholinesterase activity than controls dosed with parathion. Brain cholinesterase activity was inhibited 41% in morsodren-fed birds and 26in clean-fed birds dosed with parathion, which suggested that the increase in parathion toxicity in the presence of morsodren was directly related to the inhibitation of brain cholinesterase.

  15. Detoxification of methyl-parathion pesticide in aqueous solutions by electrochemical oxidation.

    PubMed

    Arapoglou, D; Vlyssides, A; Israilides, C; Zorpas, A; Karlis, P

    2003-03-17

    Commercial methyl-parathion (MeP) was detoxified using an electrochemical method that employed a Ti/Pt anode and stainless steel 304 as cathode. Sodium chloride was added as electrolyte and the mixture was passed through an electrolytic cell for 2 h. Due to the strong oxidizing potential of the produced chemicals, the organic pollutants were wet oxidized to carbon dioxide and water. A number of experiments were run at laboratory scale. Reductions of COD and BOD(5) were both over 80% and the mean energy consumption was 18-8 kWh per kg(-1) COD reduced (COD(r)). The degradation of MeP was more effective when the pH of the brine solution was in the acid range than when it was in the alkaline range. From the results it can be concluded that electrolysis could be used as an oxidation pre-treatment stage for detoxification of toxic wastes with MeP.

  16. Twofold role of calcined hydrotalcites in the degradation of methyl parathion pesticide

    PubMed Central

    Fetter, Geolar; Villafuerte-Castrejon, María Elena; Tejeda-Cruz, Adriana; Bosch, Pedro

    2011-01-01

    Summary Methyl parathion (MP) is a very toxic organophosphate pesticide used as a non-systematic insecticide and acaricide on many corps. As MP and its by-products are highly toxic, they have to be retained to avoid pollution of rivers and lakes. Highly efficient sorbents are hydrotalcites (HTs) (or anionic clays). We have correlated the degradation of an aqueous solution of MP at room temperature, with the basicity of the adsorbing materials. It was found that the metal composition of hydrotalcites determines both the surface electronic properties (basic or acidic) and the sorption capacity. Depending on the basic strength, some calcined hydrotalcites can catalyze the transformation of MP to p-nitrophenol (p-NP) and retain its by-products. Such a process has the advantage of being able to be carried out at room temperature and at the pH of the pesticide solution. PMID:21977419

  17. Twofold role of calcined hydrotalcites in the degradation of methyl parathion pesticide.

    PubMed

    Sampieri, Alvaro; Fetter, Geolar; Villafuerte-Castrejon, María Elena; Tejeda-Cruz, Adriana; Bosch, Pedro

    2011-01-01

    Methyl parathion (MP) is a very toxic organophosphate pesticide used as a non-systematic insecticide and acaricide on many corps. As MP and its by-products are highly toxic, they have to be retained to avoid pollution of rivers and lakes. Highly efficient sorbents are hydrotalcites (HTs) (or anionic clays). We have correlated the degradation of an aqueous solution of MP at room temperature, with the basicity of the adsorbing materials. It was found that the metal composition of hydrotalcites determines both the surface electronic properties (basic or acidic) and the sorption capacity. Depending on the basic strength, some calcined hydrotalcites can catalyze the transformation of MP to p-nitrophenol (p-NP) and retain its by-products. Such a process has the advantage of being able to be carried out at room temperature and at the pH of the pesticide solution.

  18. Reclassification of a parathione-degrading Flavobacterium sp. ATCC 27551 as Sphingobium fuliginis.

    PubMed

    Kawahara, Kazuyoshi; Tanaka, Atsushi; Yoon, Jaewoo; Yokota, Akira

    2010-06-01

    A parathione-degrading bacterium isolated from rice field in the Philippines, Flavobacterium sp. ATCC 27551 (Sethunathan and Yoshida, 1973, Can. J. Microbiol., 19, 873-875), was re-examined chemotaxonomically and phylogenetically. The strain contained 2-hydroxymyristic acid (2-OH 14 : 0), cis-vaccenic acid (18 : 1 omega7c), and palmitic acid (16 : 0) as major cellular fatty acids, two kinds of glycosphingolipids, and ubiquinone-10 as a sole quinone component. The G+C content of genomic DNA of the strain was 65.9 mol%. The phylogenetic analyses of the 16S rRNA gene indicated that the strain was included in the family Sphingomonadaceae, and most closely related to Sphingobium fuliginis (98.0% similarity) and Sphingobium herbicidovorans (97.3%). The strain showed similar physiological characteristics and a moderate value of DNA-DNA relatedness to S. fuliginis. These data suggested it reasonable to conclude that strain ATCC 27551 was identified as S. fuliginis.

  19. Improving the acidic stability of a methyl parathion hydrolase by changing basic residues to acidic residues.

    PubMed

    Huang, Lu; Wang, Ping; Tian, Jian; Jiang, Huachen; Wu, Ningfeng; Yang, Peilong; Yao, Bin; Fan, Yunliu

    2012-06-01

    The acidic stability of a methyl parathion hydrolase (Ochr-MPH) was improved by selectively changing basic amino acids to acidic ones. Mutation sites were selected based on the position-specific amino acid replacement probabilities (more than or equal to 0.2) and the entropy of each site (more than or equal to 0.8). Three mutants (K208E, K277D, and K208E/K277D) were more stable than the wild-type (WT). Their half-lives at pH 5.0 were 64, 68, 65 min, respectively, whereas that of WT was 39 min. The acidic stability of proteins may therefore be improved by changing selected basic amino acid residues to acidic ones.

  20. Differential expression profile of membrane proteins in zebrafish (Danio rerio) brain exposed to methyl parathion.

    PubMed

    Huang, Qing-Yu; Huang, He-Qing

    2011-09-01

    Methyl parathion (MP) is a widely used organophosphorus pesticide, which has been related to a broad spectrum of toxic effects on environmental organisms. The present study investigated the changes in the protein profile of enriched membrane fraction from zebrafish (Danio rerio) brain exposed to three concentrations (0.5, 1 and 2 mg/L) of MP. 2-DE revealed that the abundance of 21 protein spots was significantly changed by MP stress. By matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and database search, 16 protein spots were identified as membrane proteins, among which 8 were down-regulated, while 8 were up-regulated. These proteins are mainly involved in oxidative stress response, signal transduction, metabolism, protein synthesis and degradation, neuroplasticity and regeneration as well as synaptic transmission. These results may aid our understanding of the mechanism of MP-induced neurotoxicity and provide the possibility of the establishment of candidate biomarkers of MP.

  1. Purification and characterization of methyl parathion hydrolase from Burkholderia cepacia capable of degrading organophosphate insecticides.

    PubMed

    Ekkhunnatham, Anirut; Jongsareejit, Boonsri; Yamkunthong, Wanphen; Wichitwechkarn, Jesdawan

    2012-04-01

    Methyl parathion hydrolase (MPH) from a methyl parathion-degrading Burkholderia cepacia indigenous to Thailand was purified to apparent homogeneity by three steps of column chromatography using Resource S, Sephadex G100, and Octyl Sepharose 4FF columns. Its molecular mass was determined to be 35 kDa, and the pI to be 8.5. The recombinant plasmid pGT1, containing the MPH-encoding gene, mpdB, cloned into pGEX-4T-2 was over-expressed in Escherichia coli as GST-MPH fusion protein. The recombinant MPH was purified to homogeneity by a single step, using GSTPrep FF affinity column, with the molecular mass identical to that of the native enzyme. The purified enzyme had the specific activity of about 1,600 unit mg(-1) protein and the yield of about 75%, a 39-fold increase in recovery compared to that of the native enzyme. The optimal temperature and pH were 25°C and 9.0, respectively. The MPH was stable, with its activity unchanged for 48 h at 4°C, and reduced to 50% after 5 h and to 45% after 48 h at 25°C. The enzyme activity remained 80-90% after 8-15 h at pH 6-7. Cd(2+), Co(2+), and Zn(2+) ions at the concentration of 1 mM enhanced the activity; while sodium dodecyl sulfate (SDS), dithiothreitol (DTT) and ethylenediaminetetraacetate (EDTA) reduced it. The enzyme also showed cross reactivity with other insecticides within the organophosphate group, and the kinetic parameters for individual substrates were investigated. Since MPH from B. cepacia has wide potential applications in detoxification and detection of organophosphate compounds, this study provides important basis for its future use.

  2. Optimization of methyl parathion biodegradation and detoxification by cells in suspension or immobilized on tezontle expressing the opd gene.

    PubMed

    Abdel-Razek, Mohamed Abdel-Razek Saleh; Folch-Mallol, Jorge L; Perezgasga-Ciscomani, Lucía; Sánchez-Salinas, Enrique; Castrejón-Godínez, Maria L; Ortiz-Hernández, M Laura

    2013-01-01

    The goal of this study was to optimize methyl parathion (O,O-dimethyl-O-4-p-nitrophenyl phosphorothioate) degradation using a strain of Escherichia coli DH5α expressing the opd gene. Our results indicate that this strain had lower enzymatic activity compared to the Flavobacterium sp. ATCC 27551 strain from which the opd gene was derived. Both strains were assessed for their ability to degrade methyl parathion (MP) in a mineral salt medium with or without the addition of glucose either as suspended cells or immobilized on tezontle, a volcanic rock. MP was degraded by both strains with similar efficiencies, but immobilized cells degraded MP more efficiently than cells in suspension. However, the viability of E. coli cells was much higher than that of the Flavobacterium sp. We confirmed the decrease in toxicity from the treated effluents through acetylcholinesterase activity tests, indicating the potential of this method for the treatment of solutions containing MP.

  3. Superoxide dismutase, catalase and acetylcholinesterase: biomarkers for the joint effects of cadmium, zinc and methyl parathion contamination in water.

    PubMed

    Ling, XuePing; Zhang, YiHeng; Lu, YingHua; Huang, HeQing

    2011-10-01

    Heavy metals are known to reduce the activities of antioxidant enzymes (e.g. superoxide dismutase, catalase), while organophosphorous insecticides are known to inhibit the activity of the enzyme acetylcholinesterase. In this study, the activities of these three enzymes in zebrafish (Danio rerio) tissues were assessed to evaluate the consequences heavy metal and organophosphate contamination in aquatic systems. When the fish were contacted with water containing a single pollutant, superoxide dismutase activity was affected by the presence of Cd but not by methyl parathion or Zn. However, catalase and acetylcholinesterase activities were sensitive to all three pollutants. The combined treatment showed that the three enzymes could be chosen as biomarkers of joint pollution by both metals and organophosphate. Toxicity tests showed an antagonism interaction between methyl parathion and Cd or Zn, and the change of enzyme activities at 96 hours was in accordance with that.

  4. Effective antibodies immobilization and functionalized nanoparticles in a quartz-crystal microbalance-based immunosensor for the detection of parathion

    PubMed Central

    Della Ventura, Bartolomeo; Iannaccone, Marco; Funari, Riccardo; Pica Ciamarra, Massimo; Altucci, Carlo; Capparelli, Rosanna; Roperto, Sante; Velotta, Raffaele

    2017-01-01

    Background Biosensor-based detection provides a rapid and low-cost alternative to conventional analytical methods for revealing the presence of the contaminants in water as well as solid matrices. Although important to be detected, small analytes (few hundreds of Daltons) are an issue in biosensing since the signal they induce in the transducer, and specifically in a Quartz-Crystal Microbalance, is undetectable. A pesticide like parathion (M = 292 Da) is a typical example of contaminant for which a signal amplification procedure is desirable. Methods/Findings The ballasting of the analyte by gold nanoparticles has been already applied to heavy target as proteins or bacteria to improve the limit of detection. In this paper, we extend the application of such a method to small analytes by showing that once the working surface of a Quartz-Crystal Microbalance (QCM) has been properly functionalized, a limit of detection lower than 1 ppb is reached for parathion. The effective surface functionalization is achieved by immobilizing antibodies upright oriented on the QCM gold surface by a simple photochemical technique (Photonic Immobilization Technique, PIT) based on the UV irradiation of the antibodies, whereas a simple protocol provided by the manufacturer is applied to functionalize the gold nanoparticles. Thus, in a non-competitive approach, the small analyte is made detectable by weighing it down through a “sandwich protocol” with a second antibody tethered to heavy gold nanoparticles. The immunosensor has been proved to be effective against the parathion while showing no cross reaction when a mixture of compounds very similar to parathion is analyzed. Conclusion/Significance The immunosensor described in this paper can be easily applied to any small molecule for which polyclonal antibodies are available since both the functionalization procedure of the QCM probe surface and gold nanoparticle can be applied to any IgG, thereby making our device of general

  5. Identification of a plasmid-borne parathion hydrolase gene from Flavobacterium sp. by southern hybridization with opd from Pseudomonas diminuta.

    PubMed

    Mulbry, W W; Karns, J S; Kearney, P C; Nelson, J O; McDaniel, C S; Wild, J R

    1986-05-01

    Parathion hydrolases have been previously described for an American isolate of Pseudomonas diminuta and a Philippine isolate of Flavobacterium sp. (ATCC 27551). The gene which encodes the broad-spectrum organophosphate phosphotriesterase in P. diminuta has been shown by other investigators to be located on a 66-kilobase (kb) plasmid. The intact gene (opd, organophosphate-degrading gene) from this degradative plasmid was cloned into M13mp10 and found to express parathion hydrolase under control of the lac promoter in Escherichia coli. In Flavobacterium sp. strain ATCC 27551, a 43-kb plasmid was associated with the production of parathion hydrolase by curing experiments. The M13mp10-cloned fragment of the opd gene from P. diminuta was used to identify a homologous genetic region from Flavobacterium sp. strain ATCC 27551. Southern hybridization experiments demonstrated that a genetic region from the 43-kb Flavobacterium sp. plasmid possessed significant homology to the opd sequence. Similar hybridization did not occur with three other native Flavobacterium sp. plasmids (approximately 23, 27, and 51 kb) present within this strain or with genomic DNA from cured strains. Restriction mapping of various recombinant DNA molecules containing subcloned fragments of both opd plasmids revealed that the restriction maps of the two opd regions were similar, if not identical, for all restriction endonucleases tested thus far. In contrast, the restriction maps of the cloned plasmid sequences outside the opd regions were not similar. Thus, it appears that the two discrete bacterial plasmids from parathion-hydrolyzing soil bacteria possess a common but limited region of sequence homology within potentially nonhomologous plasmid structures.

  6. Identification of a plasmid-borne parathion hydrolase gene from Flavobacterium sp. by southern hybridization with opd from Pseudomonas diminuta.

    PubMed Central

    Mulbry, W W; Karns, J S; Kearney, P C; Nelson, J O; McDaniel, C S; Wild, J R

    1986-01-01

    Parathion hydrolases have been previously described for an American isolate of Pseudomonas diminuta and a Philippine isolate of Flavobacterium sp. (ATCC 27551). The gene which encodes the broad-spectrum organophosphate phosphotriesterase in P. diminuta has been shown by other investigators to be located on a 66-kilobase (kb) plasmid. The intact gene (opd, organophosphate-degrading gene) from this degradative plasmid was cloned into M13mp10 and found to express parathion hydrolase under control of the lac promoter in Escherichia coli. In Flavobacterium sp. strain ATCC 27551, a 43-kb plasmid was associated with the production of parathion hydrolase by curing experiments. The M13mp10-cloned fragment of the opd gene from P. diminuta was used to identify a homologous genetic region from Flavobacterium sp. strain ATCC 27551. Southern hybridization experiments demonstrated that a genetic region from the 43-kb Flavobacterium sp. plasmid possessed significant homology to the opd sequence. Similar hybridization did not occur with three other native Flavobacterium sp. plasmids (approximately 23, 27, and 51 kb) present within this strain or with genomic DNA from cured strains. Restriction mapping of various recombinant DNA molecules containing subcloned fragments of both opd plasmids revealed that the restriction maps of the two opd regions were similar, if not identical, for all restriction endonucleases tested thus far. In contrast, the restriction maps of the cloned plasmid sequences outside the opd regions were not similar. Thus, it appears that the two discrete bacterial plasmids from parathion-hydrolyzing soil bacteria possess a common but limited region of sequence homology within potentially nonhomologous plasmid structures. Images PMID:3015022

  7. D2PC sensitivity analysis

    SciTech Connect

    Lombardi, D.P.

    1992-08-01

    The Chemical Hazard Prediction Model (D2PC) developed by the US Army will play a critical role in the Chemical Stockpile Emergency Preparedness Program by predicting chemical agent transport and dispersion through the atmosphere after an accidental release. To aid in the analysis of the output calculated by D2PC, this sensitivity analysis was conducted to provide information on model response to a variety of input parameters. The sensitivity analysis focused on six accidental release scenarios involving chemical agents VX, GB, and HD (sulfur mustard). Two categories, corresponding to conservative most likely and worst case meteorological conditions, provided the reference for standard input values. D2PC displayed a wide variety of sensitivity to the various input parameters. The model displayed the greatest overall sensitivity to wind speed, mixing height, and breathing rate. For other input parameters, sensitivity was mixed but generally lower. Sensitivity varied not only with parameter, but also over the range of values input for a single parameter. This information on model response can provide useful data for interpreting D2PC output.

  8. Acute disturbance of calcium homeostasis in PC12 cells as a novel mechanism of action for (sub)micromolar concentrations of organophosphate insecticides.

    PubMed

    Meijer, Marieke; Hamers, Timo; Westerink, Remco H S

    2014-07-01

    Organophosphates (OPs) and carbamates are widely used insecticides that exert their neurotoxicity via inhibition of acetylcholine esterase (AChE) and subsequent overexcitation. OPs can induce additional neurotoxic effects at concentrations below those for inhibition of AChE, indicating other mechanisms of action are also involved. Since tight regulation of the intracellular calcium concentration ([Ca(2+)]i) is essential for proper neuronal development and function, effects of one carbamate (carbaryl) and two OPs (chlorpyrifos, parathion-ethyl) as well as their -oxon metabolites on [Ca(2+)]i were investigated. Effects of acute (20min) exposure to (mixtures of) insecticides on basal and depolarization-evoked [Ca(2+)]i were measured in fura-2-loaded PC12 cells using single-cell fluorescence microscopy. Acute exposure to chlorpyrifos and its metabolite chlorpyrifos-oxon (10μM) induced a modest increase in basal [Ca(2+)]i. More importantly, the tested OPs concentration-dependently inhibited depolarization-evoked [Ca(2+)]i. Chlorpyrifos already induced a ∼30% inhibition at 0.1μM and a 100% inhibition at 10μM (IC50=0.43μM), whereas parathion-ethyl inhibited the depolarization-evoked [Ca(2+)]i increase with ∼70% at 10μM. Interestingly, -oxon metabolites were more potent inhibitors of AChE, but were less potent inhibitors of depolarization-evoked [Ca(2+)]i compared to their parent compound (chlorpyrifos-oxon) or were even without effect (paraoxon-ethyl and -methyl). Similarly, acute exposure to carbaryl had no effect on [Ca(2+)]i. Exposure to mixtures of chlorpyrifos with its oxon-analog or with parathion-ethyl did not increase the degree of inhibition, indicating additivity does not apply. These data demonstrate that concentration-dependent inhibition of depolarization-evoked [Ca(2+)]i is a novel mechanism of action of (sub)micromolar concentrations of OPs that could partly underlie OP-induced neurotoxicity.

  9. Metabolism of carbaryl, chloropyrifos, DDT, and parathion in the European corn borer: effects of microsporidiosis on toxicity and detoxication

    SciTech Connect

    Tetreault, G.E.

    1985-01-01

    An investigation was conducted to examine the effects of microsporidiosis on an insect's response to insecticide intoxication. Healthy European corn borer, Ostrinia nubilalis, larvae and those heavily infected with the microsporidian pathogen, Nosema pyrausta, were bioassayed with ten insecticides. The compounds used were carbaryl, carbofuran, chlorophrifos, DDT, diazinon, fonofos, methomyl, parathion, permethrin, and terbufos. Third instar larvae were used for topical bioassays. The compounds carbaryl, carbofuran, chlorophrifos, methomyl and terbufos were found to be significantly more toxic to diseased insects than healthy insects at the 0.05 probability level. To examine the effect of Nosema pyrausta infection on the European corn borer's ability to detoxify insecticides, /sup 14/C ring-labeled carbaryl, chlorophrifos, DDT, and parathion were topically applied to fourth instar larvae. Qualitative differences between healthy and diseased insects were found in the metabolic pathways of carbaryl, DDT, and parathion. The degradative fate of chlorophrifos was the same in both groups. Quantitatively, each insecticide penetrated diseased larvae faster. This resulted in larger amounts of the applied dose of parent compound and metabolites being found in the feces from diseased insects. Conversely, healthy insects had more of these materials present in the body and associated with the cuticle.

  10. The interaction of the phosphorothioate insecticides chlorpyrifos and parathion and their oxygen analogues with bovine serum albumin.

    PubMed

    Sultatos, L G; Basker, K M; Shao, M; Murphy, S D

    1984-07-01

    The distribution and subsequent toxicity of hazardous chemicals can be influenced by their interactions with plasma proteins. In the present study reversible binding of the phosphorothioate insecticides chlorpyrifos and parathion to fatty acid-free bovine serum albumin (BSA) was examined using the technique of equilibrium dialysis. Computer analyses of the binding data revealed that chlorpyrifos and parathion each bound reversibly to a single class of binding sites on BSA, with apparent KD values of 3.4 +/- 0.1 and 11.1 +/- 0.3 microM, respectively. Additionally, the maximal number of binding sites for each insecticide per molecule of BSA was one. Displacement studies using both chlorpyrifos and parathion indicated that each was a competitive inhibitor of the other's binding, suggesting that they were bound to the same site. Incubation of chlorpyrifos oxon or paraoxon with a 1% solution of BSA resulted in limited, EDTA-insensitive formation of 3,5,6-trichloro-2-pyridinol or p-nitrophenol, respectively. Pretreatment of BSA with 5 mM paraoxon, chlorpyrifos oxon, or 1 mM diisopropylfluorophosphate did not alter this activity, suggesting that these reactions resulted from an esterase-like capacity of BSA, and not from phosphorylation of BSA by these oxons.

  11. Acute and chronic effects of parathion and 2,4 D on the oxygen consumption of Chasmagnathus granulata (Decapoda, Brachyura).

    PubMed

    Rodríguez, E M; Monserrat, J M

    1991-01-01

    The effect of two pesticides widely used in Argentina on the oxygen consumption of the estuarine crab Chasmagnathus granulata was studied. Constant pressure respirometers were employed to estimate the rate of oxygen consumption per weight unit of animals treated previously with each pesticide, both acute (96 h) and chronically (15 and 30 days). Crabs exposed to parathion -an organophosphorate insecticide that causes the inhibition of acetylcholinesterase- show an increase of oxygen consumption at 0.5 ppm under acute exposure, and at 10 ppb under a chronic one. On the other hand, crabs exposed to 2,4 D (an herbicide) did not show changes in their consumption after an acute exposure, but those exposed chronically did show an increase at low concentration (5 ppm) followed by a relative decrease at the highest concentration (50 ppm). The results obtained for parathion are in accordance with the abnormal cholinergic excitation that it may exert on crustacean nervous system. The effect of 2,4 D was consistent with its uncoupler action at respiratory chain level, at low concentrations, while a possible Krebs cycle enzymes inhibition might be occurring at higher concentrations of that pesticide, as in other crustacean species. The faster action of parathion, respect to 2,4 D, is explained by its neurotoxic nature.

  12. An approach for the quantitative consideration of genetic polymorphism data in chemical risk assessment: examples with warfarin and parathion.

    PubMed

    Gentry, P Robinan; Hack, C Eric; Haber, Lynne; Maier, Andrew; Clewell, Harvey J

    2002-11-01

    In recent years, a great deal of research has been conducted to identify genetic polymorphisms. One focus has been to characterize variability in metabolic enzyme systems that could impact internal doses of pharmaceuticals or environmental pollutants. Methods are needed for using this metabolic information to estimate the resulting variability in tissue doses associated with chemical exposure. We demonstrate here the use of physiologically based pharmacokinetic (PBPK) modeling in combination with Monte Carlo analysis to incorporate information on polymorphisms into the analysis of toxicokinetic variability. Warfarin and parathion were used as case studies to demonstrate this approach. Our results suggest that polymorphisms in the PON1 gene, that give rise to allelic variants of paraoxonase, which is involved in the metabolism of paraoxon (a metabolite of parathion), make only a minor contribution to the overall variability in paraoxon tissue dose, while polymorphisms in the CYP2C9 gene, which gives rise to allelic variants of the major metabolic enzyme for warfarin, account for a significant portion of the overall variability in (S)-warfarin tissue dose. These analyses were used to estimate chemical-specific adjustment factors (CSAFs) for the human variability in toxicokinetics for both parathion and warfarin. Implications of alternatives in the calculation of CSAFs are explored. Key decision points for applying the PBPK-Monte Carlo approach to evaluate toxicokinetic variability for other chemicals are also discussed.

  13. Covalent coupling of organophosphorus hydrolase loaded quantum dots to carbon nanotube/Au nanocomposite for enhanced detection of methyl parathion.

    PubMed

    Du, Dan; Chen, Wenjuan; Zhang, Weiying; Liu, Deli; Li, Haibing; Lin, Yuehe

    2010-02-15

    An amperometric biosensor for highly selective and sensitive determination of methyl parathion (MP) was developed based on dual-signal amplification: (1) a large amount of introduced enzyme on the electrode surface and (2) synergistic effects of nanoparticles towards enzymatic catalysis. The fabrication process includes (1) electrochemical deposition of gold nanoparticles by a multi-potential step technique at multiwalled carbon nanotube (MWCNT) film pre-cast on a glassy carbon electrode and (2) immobilization of methyl parathion degrading enzyme (MPDE) onto a modified electrode through CdTe quantum dots (CdTe QDs) covalent attachment. The introduced MWCNT and gold nanoparticles significantly increased the surface area and exhibited synergistic effects towards enzymatic catalysis. CdTe QDs are further used as carriers to load a large amount of enzyme. As a result of these two important enhancement factors, the proposed biosensor exhibited extremely sensitive, perfectly selective, and rapid response to methyl parathion in the absence of a mediator. The detection limit was 1.0 ng/mL. Moreover, since MPDE hydrolyzes pesticides containing the P-S bond, it showed high selectivity for detecting MP and many interfering compounds, such as carbamate pesticides. Other organophosphorous pesticides and oxygen-containing inorganic ions (SO(4)(2-), NO(3)(-)) did not interfere with the determination. The proposed MPDE biosensor presents good reproducibility and stability, and the MPDE is not poisoned by organophosphate pesticides. Unlike cholinesterase-based biosensor, the MPDE biosensor can be potentially reused and is suitable for continuous monitoring.

  14. An optical microbial biosensor for detection of methyl parathion using Sphingomonas sp. immobilized on microplate as a reusable biocomponent.

    PubMed

    Kumar, Jitendra; D'Souza, S F

    2010-12-15

    Organophosphorus pesticides such as methyl parathion have been widely used in the field of agriculture for insect pest control. These pesticides and their degradation products cause environmental pollution and ecological problem. With a view to monitor these pesticides biosensors are being developed. A bacterium Sphingomonas sp. from field soil has been isolated and identified in our laboratory that hydrolyzes the methyl parathion upto a chromophoric product, p-nitrophenol (PNP). PNP can be detected by electrochemical and colorimetric methods, which can be exploited to develop a biosensor for detection of the organophosphate pesticide. Whole cells of Sphingomonas bacteria were immobilized directly onto the surface of the wells of polystyrene microplates (96 wells) using glutaraldehyde as the cross-linker. SEM study confirmed the immobilization of Sphingomonas sp. Immobilized bacterial microplate was associated directly with the optical transducer, microplate reader. The microplate-based biosensor is having advantages as it has 96 reaction vessels and therefore it provides a convenient system for detecting multiple numbers of samples in a single platform. Detection range of the biosensor from the linear range was determined to be 4-80 μM methyl parathion. Cells-immobilized microplates were having reusability upto 75 reactions. Present study reports an innovative concept where the microplate can be used as immobilizing support for development of reusable microbial biocomponent.

  15. A simple and sensitive fluorescent sensor for methyl parathion based on L-tyrosine methyl ester functionalized carbon dots.

    PubMed

    Hou, Juying; Dong, Jing; Zhu, Haishuang; Teng, Xue; Ai, Shiyun; Mang, Minglin

    2015-06-15

    In this paper, a simple and sensitive fluorescent sensor for methyl parathion is developed based on L-tyrosine methyl ester functionalized carbon dots (Tyr-CDs) and tyrosinase system. The carbon dots are obtained by simple hydrothermal reaction using citric acid as carbon resource and L-tyrosine methyl ester as modification reagent. The carbon dots are characterized by transmission electron microscope, high resolution transmission electron microscopy, X-ray diffraction spectrum, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The carbon dots show strong and stable photoluminescence with a quantum yield of 3.8%. Tyrosinase can catalyze the oxidation of tyrosine methyl ester on the surface of carbon dots to corresponding quinone products, which can quench the fluorescence of carbon dots. When organophosphorus pesticides (OPs) are introduced in system, they can decrease the enzyme activity, thus decrease the fluorescence quenching rate. Methyl parathion, as a model of OPs, was detected. Experimental results show that the enzyme inhibition rate is proportional to the logarithm of the methyl parathion concentration in the range 1.0×10(-10)-1.0×10(-4) M with the detection limit (S/N=3) of 4.8×10(-11) M. This determination method shows a low detection limit, wide linear range, good selectivity and high reproducibility. This sensing system has been successfully used for the analysis of cabbage, milk and fruit juice samples.

  16. Effects of Exposure to Methyl Parathion on Egg Hatchability and Eggshell Chemical Composition in Podocnemis expansa (Testudines, Podocnemididae).

    PubMed

    Valdes, Sady Alexis Chavauty; Vieira, Lucélia Gonçalves; Ferreira, Caio Henrique; dos Santos Mendonça, Juliana; Ribeiro, Priscilla Rosa Queiroz; de Abreu Fernandes, Evandro; Santos, André Luiz Quagliatto

    2015-04-01

    Eggshell evaluation may serve as an indicator of the effect of substances released in the environment, which may change eggshell shape, size, structure, and/or chemical composition. Additionally, exposure may interfere with hatching rates in contaminated eggs. The objective of this study was to better understand how exposure to the insecticide methyl parathion interferes with chemical changes in eggshells of Podocnemis expansa throughout their artificial incubation, as well as with egg hatchability. A total of 343 P. expansa eggs were collected in a natural reproduction area for the species. These eggs were transferred to and artificially incubated in the Wild Animal Teaching and Research Laboratory at Universidade Federal de Uberlândia. On the first day of artificial incubation, 0, 35, 350, and 3500 ppb of methyl parathion were incorporated to the substrate. Eggs were collected every three days for chemical analysis of eggshells. Hatchability was evaluated as the number of hatchlings in each treatment, for the eggs that were not used in the chemical analysis. Student's T-test was used for data on eggshell chemical composition, and the Binomial Test for Two Proportions was used in the hatchability analysis, at a 5% significance level. It was observed that the incorporation of methyl parathion to the substrate on the first day of artificial incubation of P. expansa eggs reduced the levels of total fat in the shells throughout their incubation, besides reducing egg hatchability.

  17. Effect of ionising radiation on polyphenolic content and antioxidant potential of parathion-treated sage (Salvia officinalis) leaves.

    PubMed

    Ben Salem, Issam; Fekih, Sana; Sghaier, Haitham; Bousselmi, Mehrez; Saidi, Mouldi; Landoulsi, Ahmed; Fattouch, Sami

    2013-11-15

    The γ-irradiation effects on polyphenolic content and antioxidant capacity of parathion-pretreated leaves of Salvia officinalis plant were investigated. The analysis of phenolic extracts of sage without parathion showed that irradiation decreased polyphenolic content significantly (p<0.05) by 30% and 45% at 2 and 4kGy, respectively, compared to non-irradiated samples. The same trend was observed for the Trolox equivalent antioxidant capacity (TEAC), as assessed by the anionic DPPH and cationic ABTS radical-scavenging assays. The antioxidant potential decreased significantly (p<0.01) at 2 and 4kGy, by 11-20% and 40-44%, respectively. The results obtained with a pure chlorogenic acid solution confirmed the degradation of phenols; however, its TEAC was significantly (p<0.01) increased following irradiation. Degradation products of parathion formed by irradiation seem to protect against a decline of antioxidant capacity and reduce polyphenolic loss. Ionising radiation was found to be useful in breaking down pesticide residues without inducing significant losses in polyphenols.

  18. Comparative effects of parathion and chlorpyrifos on extracellular endocannabinoid levels in rat hippocampus: Influence on cholinergic toxicity

    SciTech Connect

    Liu, Jing; Parsons, Loren; Pope, Carey

    2013-11-01

    Parathion (PS) and chlorpyrifos (CPF) are organophosphorus insecticides (OPs) that elicit acute toxicity by inhibiting acetylcholinesterase (AChE). Endocannabinoids (eCBs, N-arachidonoylethanolamine, AEA; 2-arachidonoylglycerol, 2AG) can modulate neurotransmission by inhibiting neurotransmitter release. We proposed that differential inhibition of eCB-degrading enzymes (fatty acid amide hydrolase, FAAH, and monoacylglycerol lipase, MAGL) by PS and CPF leads to differences in extracellular eCB levels and toxicity. Microdialysis cannulae were implanted into hippocampus of adult male rats followed by treatment with vehicle (peanut oil, 2 ml/kg, sc), PS (27 mg/kg) or CPF (280 mg/kg) 6–7 days later. Signs of toxicity, AChE, FAAH and MAGL inhibition, and extracellular levels of AEA and 2AG were measured 2 and 4 days later. Signs were noted in PS-treated rats but not in controls or CPF-treated rats. Cholinesterase inhibition was extensive in hippocampus with PS (89–90%) and CPF (78–83%) exposure. FAAH activity was also markedly reduced (88–91%) by both OPs at both time-points. MAGL was inhibited by both OPs but to a lesser degree (35–50%). Increases in extracellular AEA levels were noted after either PS (about 2-fold) or CPF (about 3-fold) while lesser treatment-related 2-AG changes were noted. The cannabinoid CB1 receptor antagonist/inverse agonist AM251 (3 mg/kg, ip) had no influence on functional signs after CPF but markedly decreased toxicity in PS-treated rats. The results suggest that extracellular eCBs levels can be markedly elevated by both PS and CPF. CB1-mediated signaling appears to play a role in the acute toxicity of PS but the role of eCBs in CPF toxicity remains unclear. - Highlights: • Chlorpyrifos and parathion both extensively inhibited hippocampal cholinesterase. • Functional signs were only noted with parathion. • Chlorpyrifos and parathion increased hippocampal extracellular anandamide levels. • 2-Arachidonoylglycerol levels were

  19. Activation and degradation of the phosphorothionate insecticides parathion and EPN by rat brain.

    PubMed

    Forsyth, C S; Chambers, J E

    1989-05-15

    Cytochrome P-450-dependent monooxygenases are known to activate phosphorothionate insecticides to their oxon (phosphate) analogs by oxidative desulfuration. These activations produced potent anticholinesterases, decreasing the I50 values to rat brain acetylcholinesterase almost 1000-fold (from the 10(-5) M range to the 10(-8) M range). Since the usual cause of death in mammals from organophosphorus insecticide poisoning is respiratory failure resulting, in part, from a failure of the respiratory control center of the brain, we investigated the ability of rat brain to activate and subsequently degrade two phosphorothionate insecticides, parathion (diethyl 4-nitrophenyl phosphorothioate) and EPN (ethyl 4-nitrophenyl phenylphosphonothioate). Microsomes from specific regions (cerebral cortex, corpus striatum, cerebellum, and medulla/pons) of the brains of male and female rats and from liver were incubated with the phosphorothionate and an NADPH-generating system. Oxon production was quantified indirectly by the amount of inhibition resulting in an exogenous source of acetylcholinesterase added to the incubation mixture as an oxon trap. The microsomal activation specific activity was low for brain when compared to liver [0.23 to 0.44 and 5.1 to 12.0 nmol.min-1.(g tissue)-1 respectively]. The mitochondrial fraction of the brain possessed an activation activity for parathion similar to that of microsomes [about 0.35 nmol.min-1.(g tissue)-1 for each fraction], but mitochondrial activity was slightly greater than microsomal activity for EPN activation [0.53 to 0.58 and 0.23 to 0.47 nmole.min-1.(g tissue)-1]. Whole homogenates were tested for their ability to degrade paraoxon and EPN-oxon (ethyl 4-nitrophenyl phenylphosphonate), quantitated by 4-nitrophenol production. Specific activity for oxon degradation in liver was greater than that in brain [31 to 74 and 1.1 to 10.7 nmole.min-1.(g tissue)-1 respectively]. Overall, the brain and liver had about 1.5- to 12-fold higher

  20. Comparison of biosorption and phytoremediation of cadmium and methyl parathion, a case-study with live Lemna gibba and Lemna gibba powder.

    PubMed

    Halaimi, F Z; Kellali, Y; Couderchet, M; Semsari, S

    2014-07-01

    Heavy metals and pesticides can be adsorbed by several biomasses such as living or non-living aquatic plants. In this study adsorption properties of live Lemna gibba and Lemna gibba powder were investigated with regard to cadmium and methyl parathion (MP). Toxicity data (IC50) on live L. gibba indicated that the period of four days was adequate for phytoremediation. Initial adsorption studies showed that both adsorbents were capable of removing cadmium and methyl parathion. Cadmium and methyl parathion adsorption onto L. gibba powder was fast and equilibrium was attained within 120min. The adsorption data could be well interpreted by the Freundlich model. The KF were: 7.8963 (Cd(2+)/ live Lemna); 0.7300 (MP/live Lemna); 11.5813 (Cd(2+)/Lemna powder); 1.1852 (MP/Lemna powder) indicating that Cd(2+) was more efficiently removed by both biosorbents than MP. Adsorption kinetics for cadmium and methyl parathion in both systems and rate constants were determined for each contaminant. It was found that the overall adsorption process was best described by pseudo-second-order kinetics. Boyd model and external mass-transfer expression were tested. It was concluded that cadmium and methyl parathion sorption onto Lemna powder is governed by film diffusion.

  1. Polar Codes

    DTIC Science & Technology

    2014-12-01

    density parity check (LDPC) code, a Reed–Solomon code, and three convolutional codes. iii CONTENTS EXECUTIVE SUMMARY...the most common. Many civilian systems use low density parity check (LDPC) FEC codes, and the Navy is planning to use LDPC for some future systems...other forward error correction methods: a turbo code, a low density parity check (LDPC) code, a Reed–Solomon code, and three convolutional codes

  2. PC25{trademark} product and manufacturing experience

    SciTech Connect

    Hall, E.W.; Riley, W.C.; Sandelli, G.J.

    1996-12-31

    Product and manufacturing experience accumulated since the beginning of PC25. A production in 1991 provides a strong base of demonstration and experience for establishing future improvements to the PC25 power plant.

  3. Hydrolysis mechanism of methyl parathion evidenced by Q-Exactive mass spectrometry.

    PubMed

    Liu, Yuan; Zhang, Caixiang; Liao, Xiaoping; Luo, Yinwen; Wu, Sisi; Wang, Jianwei

    2015-12-01

    Organophosphorus pesticides (OPPs), a kind of widely used pesticides, are currently attracting great attention due to their adverse effects on human central nervous systems, particularly in children. Although the hydrolysis behavior of OPPs has been studied well, its hydrolysis mechanism remained controversial, especially at various pH conditions, partly due to their relatively complex structures and abundant moieties that were prone to be attacked by nucleophiles. The Q-Exactive mass spectrometer, part of those hybrid high-resolution mass spectrometers (HRMS), was used to determine hydrolysis products of methyl parathion (MP), a kind of OPPs in situ buffer aqueous solution with pH ranging from 1 to 13 in this study. Most of the complex hydrolysis products of MP were identified due to the high sensitivity and accuracy of HRMS. The results demonstrated that the hydrolysis rate and pathway of MP were strong pH dependent. With the increase of pH, the hydrolysis rate of MP increased, and two different reaction mechanisms were identified: SN (2)@P pathway dominated the hydrolysis process at high pH (e.g., pH ≥ 11) while SN (2)@C was the main behavior at low pH (e.g., pH ≤ 9). This study helps understand the hydrolysis mechanism of OPPs at various pH and extends the use of Q-Exactive mass spectrometry in identifying organic pollutants and their degradation products in environmental matrices.

  4. Probing the mechanisms for the selectivity and promiscuity of methyl parathion hydrolase

    PubMed Central

    Purg, Miha; Pabis, Anna; Baier, Florian; Tokuriki, Nobuhiko; Jackson, Colin

    2016-01-01

    Diverse organophosphate hydrolases have convergently evolved the ability to hydrolyse man-made organophosphates. Thus, these enzymes are attractive model systems for studying the factors shaping enzyme functional evolution. Methyl parathion hydrolase (MPH) is an enzyme from the metallo-β-lactamase superfamily, which hydrolyses a wide range of organophosphate, aryl ester and lactone substrates. In addition, MPH demonstrates metal-ion-dependent selectivity patterns. The origins of this remain unclear, but are linked to open questions about the more general role of metal ions in functional evolution and divergence within enzyme superfamilies. Here, we present detailed mechanistic studies of the paraoxonase and arylesterase activities of MPH complexed with five different transition metal ions, and demonstrate that the hydrolysis reactions proceed via similar pathways and transition states. However, while it is possible to discern a clear structural origin for the selectivity between different substrates, the selectivity between different metal ions appears to lie instead in the distinct electrostatic properties of the metal ions themselves, which causes subtle changes in transition state geometries and metal–metal distances at the transition state rather than significant structural changes in the active site. While subtle, these differences can be significant for shaping the metal-ion-dependent activity patterns observed for this enzyme. This article is part of the themed issue ‘Multiscale modelling at the physics–chemistry–biology interface’. PMID:27698033

  5. Alterations of protein profile in zebrafish liver cells exposed to methyl parathion: a membrane proteomics approach.

    PubMed

    Huang, Qingyu; Huang, He-Qing

    2012-03-01

    Methyl parathion (MP) is an extensively used organophosphorus pesticide, which has been associated with a wide spectrum of toxic effects on environmental organisms. The aim of this study is to investigate the alterations of membrane protein profiles in zebrafish liver (ZFL) cell line exposed to MP for 24 h using proteomic approaches. Two-dimensional gel electrophoresis revealed a total of 13 protein spots, whose expression levels were significantly altered by MP. These differential proteins were subjected to matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry analysis, and nine proteins were identified to be membrane proteins, among which seven were up-regulated, while two were down-regulated. In addition, the mRNA levels corresponding to these differential membrane proteins were further analyzed by quantitative real-time PCR. And the differential expression of arginase-2 was specially validated via Western blotting. Regarding the physiological functions, these proteins are involved in molecular chaperon, cytoskeleton system, cell metabolism, signal transduction, transport and hormone receptor respectively, suggesting the complexity of MP-mediated toxicity to ZFL cell. These data could provide useful insights for better understanding the hepatotoxic mechanisms of MP and develop novel protein biomarkers for effectively monitoring MP contamination level in aquatic environment.

  6. Direct synthesis of graphene-chitosan composite and its application as an enzymeless methyl parathion sensor.

    PubMed

    Yang, Shanli; Luo, Shenglian; Liu, Chengbin; Wei, Wanzhi

    2012-08-01

    This paper proposed a direct electrodeposition approach to synthesis of graphene-chitosan (GR-CS) composite onto glassy carbon electrode (GCE) under controlled potential. This direct electrodeposition approach for the construction of GR-based hybrid was environmentally friendly, which would not involve the chemical reduction of graphene oxide (GO) and therefore result in no further contamination. The whole procedure was simply and cost only several minutes. Moreover, Combining the advantages of GR (large surface-to-volume ratio and high conductivity) and CS (good biocompatibility and adsorption), the GR-CS composite could be highly efficient to capture OPs and used as solid phase extraction (SPE). The GR-CS/GCE was used to detect organophosphate pesticides (OPs), using methyl parathion (MP) as a model analyte. The significantly redox response of MP on the GR-CS/GCE was proved. The linear range was wide from 4.0 ng mL(-1) to 400 ng mL(-1), and a low detection limit of 0.8 ng mL(-1) for MP was achieved. Moreover, the proposed sensor exhibited high reproducibility, long-time storage stability and satisfactory anti-interference ability. The proposed GR-CS/GCE opens new opportunity for green, fast, simple, and sensitive analysis of OP compounds.

  7. Protective effect of sodium aescinate on lung injury induced by methyl parathion.

    PubMed

    Du, Yuan; Wang, Tian; Jiang, Na; Ren, Ru-Tong; Zhao, De-Lu; Li, Chong; Fu, Feng-Hua

    2011-10-01

    Methyl parathion (MP) is a high venenosus insecticide. It has been used in pest control of agriculture for several years. The present study is performed to investigate the protective effect of sodium aescinate (SA) on lung injury induced by MP. Forty male Sprague-Dawley rats are randomly divided into five groups, with 8 animals in each group: control group, MP administration group, MP plus SA at doses of 0.45 mg/kg, 0.9 mg/kg and 1.8 mg/kg groups. Acetylcholinesterase (AChE) activity and nitric oxide (NO) level in plasma, myeloperoxidase (MPO) activity, NO level, and antioxidative parameters in lung tissue are assayed. Histopathological examination of lung is also performed. The results show that SA has no effect on AChE. Treatment with SA decreases the activity of MPO in lung and the level of NO in plasma and lung. The level of malondialdehyde in lung is decreased after SA treatments. SA increases the activities of superoxide dismutase, glutathione peroxidase and the content of glutathione in lung. SA administration also ameliorates lung injury induced by MP. The findings indicate that SA could protect lung injury induced by MP and the mechanism of action is related to the anti-inflammatory and anti-oxidative effect of SA.

  8. Fluorescent transgenic zebrafish as a biosensor for growth-related effects of methyl parathion.

    PubMed

    Almeida, Daniela Volcan; Vaz, Bernardo; Azevedo Figueiredo, Márcio; Junior, Antonio Sergio Varela; Marins, Luis Fernando

    2014-07-01

    Transgenic fish models are potential alternative subjects in toxicological studies, since they can provide in vivo information on the deleterious effects of different substances. Here, we used a transgenic zebrafish (Danio rerio) lineage, which expresses a destabilized fluorescent protein (DsRED) driven by the myosin light chain promoter (Mylz2), in order to propose a new research tool for environmental biomonitoring. For validating the MYO-RED lineage, we exposed fish to the organophosphorated pesticide methyl parathion (MP). The effect of MP on fish growth was assessed by evaluating weight, length, condition factor and muscle fiber diameter. All factors suffered reduction at both tested concentrations (0.13μM and 13μM of MP). Similarly, fluorescence intensity decreased in a concentration-dependent manner, suggesting muscle protein catabolism. However, DsRED gene expression lowered only at the higher MP concentration. Results indicate that the MYO-RED transgenic zebrafish is an interesting model for detecting the growth-related effects of pollutants. Destabilized proteins such as reporter genes are apparently sensitive biomarkers, since effects were observed even at the lower, environmentally acceptable concentration. Therefore, this transgenic fish is a promising candidate model for sensitive, fast, and easy environmental monitoring.

  9. Selection of a whole-cell biocatalyst for methyl parathion biodegradation.

    PubMed

    Yang, Jijian; Liu, Ruihua; Jiang, Hong; Yang, Yao; Qiao, Chuanling

    2012-09-01

    Whole-cell biocatalyst has the potential to become a cost-effective alternative to conventional enzyme methods for solving ecological and energy issues. However, cytosolic-expressing biocatalyst systems are critically disadvantaged due to the low permeability of the cell membrane. To overcome substrate transport barrier, periplasmic secretion and surface display biocatalysts were developed by expressing signal peptides or anchor proteins in Escherichia coli. In this work, six carriers were compared in regard to whole-cell activity of methyl parathion hydrolase (MPH). Our results indicate that the surface display systems yielded one to three times whole-cell activity than the periplasmic secretion systems. Although periplasmic secretion systems showed generally more stable than surface display systems, surface display appeared more suitable for whole-cell biocatalyst. It should note that the applicability of the DsbA/PhoA/AIDA-I leader to MPH expression is shown here for the first time. In addition, the result provided a useful reference for other whole-cell biocatalyst selection.

  10. Interfacial interaction between methyl parathion-degrading bacteria and minerals is important in biodegradation.

    PubMed

    Zhao, Gang; Huang, Qiaoyun; Rong, Xingmin; Cai, Peng; Liang, Wei; Dai, Ke

    2014-02-01

    In the present study, the influence of kaolinite and goethite on microbial degradation of methyl parathion was investigated. We observed that the biodegradation process was improved by kaolinite and depressed by goethite. Calorimetric data further showed that the metabolic activities of degrading cells (Pseudomonas putida) were enhanced by the presence of kaolinite and depressed by the presence of goethite. A semipermeable membrane experiment was performed and results supported the above observations: the promotive effect of kaolinite and the inhibition of goethite for microbial degradation was not found when the bacteria was enclosed by semipermeable membrane and had no direct contact with these minerals, suggesting the important function of the contact of cellular surfaces with mineral particles. The relative larger particles of kaolinite were loosely attached to the bacteria. This attachment made the cells easy to use the sorbed substrate and then stimulated biodegradation. For goethite, small particles were tightly bound to bacterial cells and limited the acquisition of substrate and nutrients, thereby inhibiting biodegradation. These results indicated that interfacial interaction between bacterial cells and minerals significantly affected the biodegradation of pesticides.

  11. Determination of methyl parathion in water and its removal on zirconia using optical enzyme assay.

    PubMed

    Deshpande, Kanchanmala; Mishra, Rupesh K; Bhand, Sunil

    2011-07-01

    A simple, miniaturized microplate chemiluminescence assay for determination of methyl parathion (MP) was developed in 384-microwell plates. Zirconia (ZrO(2)) was added in microwell for adsorption of acetylcholinesterase (AChE). The developed assay is based on inhibition of AChE by MP. A good dynamic range 0.008-1,000 ng/mL was obtained for MP with limit of detection 0.008 ng/mL. Intrabatch and interbatch reproducibility for miniaturized assay was obtained with % RSD up to 3.07 and 5.66, respectively. In 384 well plate formats, 70 samples were simultaneously analyzed within 20 min with assay volume of 41.5 μL. The application of developed assay was extended for MP remediation. Column containing ZrO(2) was utilized for remediation where MP was selectively adsorbed. Under optimized condition, adsorption of MP on ZrO(2) was found to be 98-99% with 2-h contact time in real water samples. Adsorption of MP on ZrO(2) column followed by quantification using developed bioassay provides a novel approach to monitor remediation. The applicability of assay was successfully extended for determination of MP in water samples after removal through ZrO(2).

  12. Kinetic analysis of the hydrolysis of methyl parathion using citrate-stabilized 10 nm gold nanoparticles.

    PubMed

    Nita, Rafaela; Trammell, Scott A; Ellis, Gregory A; Moore, Martin H; Soto, Carissa M; Leary, Dagmar H; Fontana, Jake; Talebzadeh, Somayeh F; Knight, D Andrew

    2016-02-01

    "Ligand-free" citrate-stabilized 10 nm gold nanoparticles (AuNPs) promote the hydrolysis of the thiophosphate ester methyl parathion (MeP) on the surface of gold as a function of pH and two temperature values. At 50 °C, the active surface gold atoms show catalytic turnover ∼4 times after 8 h and little turnover of gold surface atoms at 25 °C with only 40% of the total atoms being active. From Michaelis-Menten analysis, k(cat) increases between pH 8 and 9 and decreases above pH 9. A global analysis of the spectral changes confirmed the stoichiometric reaction at 25 °C and the catalytic reaction at 50 °C and mass spectrometry confirmed the identity of p-nitrophenolate (PNP) product. Additional decomposition pathways involving oxidation and hydrolysis independent of the formation of PNP were also seen at 50 °C for both catalyzed and un-catalyzed reactions. This work represents the first kinetic analysis of ligand-free AuNP catalyzed hydrolysis of a thiophosphate ester.

  13. Improving the thermostability of a methyl parathion hydrolase by adding the ionic bond on protein surface.

    PubMed

    Su, Yidan; Tian, Jian; Wang, Ping; Chu, Xiaoyu; Liu, Guoan; Wu, Ningfeng; Fan, Yunliu

    2011-10-01

    The thermostability of the methyl parathion hydrolase (MPH_OCH) from Ochrobactrum sp. M231 was improved using site-directed mutagenesis. Two prolines (Pro76 and Pro78) located on the protein surface were selected for mutations after inspection of the sequence alignment of MPH_OCH and OPHC2, a thermostable organophosphorus hydrolase from Pseudomonas pseudoalcaligenes C2-1. The temperature of the double-point mutant (P76D/P78K) at which the mutant lost 50% of its activity (T50) was approximately 68 °C, which is higher than that of WT enzyme (64 °C), P76D (67 °C), and P78K (59 °C). Structural analysis of P76D/P78K indicated that the substituted residues (Asp76 and Lys78) could generate an ionic bond and increase the structural electrostatic energy, which could then increase the stability of the protein. These results also suggest that the thermal stability of proteins could be improved by adding the ionic bond on protein surface.

  14. Probing the mechanisms for the selectivity and promiscuity of methyl parathion hydrolase.

    PubMed

    Purg, Miha; Pabis, Anna; Baier, Florian; Tokuriki, Nobuhiko; Jackson, Colin; Kamerlin, Shina Caroline Lynn

    2016-11-13

    Diverse organophosphate hydrolases have convergently evolved the ability to hydrolyse man-made organophosphates. Thus, these enzymes are attractive model systems for studying the factors shaping enzyme functional evolution. Methyl parathion hydrolase (MPH) is an enzyme from the metallo-β-lactamase superfamily, which hydrolyses a wide range of organophosphate, aryl ester and lactone substrates. In addition, MPH demonstrates metal-ion-dependent selectivity patterns. The origins of this remain unclear, but are linked to open questions about the more general role of metal ions in functional evolution and divergence within enzyme superfamilies. Here, we present detailed mechanistic studies of the paraoxonase and arylesterase activities of MPH complexed with five different transition metal ions, and demonstrate that the hydrolysis reactions proceed via similar pathways and transition states. However, while it is possible to discern a clear structural origin for the selectivity between different substrates, the selectivity between different metal ions appears to lie instead in the distinct electrostatic properties of the metal ions themselves, which causes subtle changes in transition state geometries and metal-metal distances at the transition state rather than significant structural changes in the active site. While subtle, these differences can be significant for shaping the metal-ion-dependent activity patterns observed for this enzyme.This article is part of the themed issue 'Multiscale modelling at the physics-chemistry-biology interface'.

  15. METCAN-PC - METAL MATRIX COMPOSITE ANALYZER

    NASA Technical Reports Server (NTRS)

    Murthy, P. L.

    1994-01-01

    High temperature metal matrix composites offer great potential for use in advanced aerospace structural applications. The realization of this potential however, requires concurrent developments in (1) a technology base for fabricating high temperature metal matrix composite structural components, (2) experimental techniques for measuring their thermal and mechanical characteristics, and (3) computational methods to predict their behavior. METCAN (METal matrix Composite ANalyzer) is a computer program developed to predict this behavior. METCAN can be used to computationally simulate the non-linear behavior of high temperature metal matrix composites (HT-MMC), thus allowing the potential payoff for the specific application to be assessed. It provides a comprehensive analysis of composite thermal and mechanical performance. METCAN treats material nonlinearity at the constituent (fiber, matrix, and interphase) level, where the behavior of each constituent is modeled accounting for time-temperature-stress dependence. The composite properties are synthesized from the constituent instantaneous properties by making use of composite micromechanics and macromechanics. Factors which affect the behavior of the composite properties include the fabrication process variables, the fiber and matrix properties, the bonding between the fiber and matrix and/or the properties of the interphase between the fiber and matrix. The METCAN simulation is performed as point-wise analysis and produces composite properties which are readily incorporated into a finite element code to perform a global structural analysis. After the global structural analysis is performed, METCAN decomposes the composite properties back into the localized response at the various levels of the simulation. At this point the constituent properties are updated and the next iteration in the analysis is initiated. This cyclic procedure is referred to as the integrated approach to metal matrix composite analysis. METCAN-PC

  16. Sequential role of biosorption and biodegradation in rapid removal, degradation and utilization of methyl parathion as a phosphate source by a new cyanobacterial isolate Scytonema sp. BHUS-5.

    PubMed

    Tiwari, Balkrishna; Singh, Savita; Chakraborty, Sindhunath; Verma, Ekta; Mishra, Arun Kumar

    2017-03-20

    A new isolate of genus Scytonema distinct from its closest relative Scytonema hofmanni was found efficient in removal and degradation of organophosphorus pesticide methyl parathion (MP). The cyanobacterial isolate was also capable to utilize the phosphorous present in the methyl parathion following its degradation which was evident from the increase in growth (chlorophyll content), biomass, protein content and total phosphorous in comparison to cyanobacterium grown in phosphate deficient cultures. The rapid removal of MP by the cyanobacterium during initial 6 hours of incubation was defined by the pseudo second order of biosorption kinetics model, which has indicated the involvement of chemosorption in initial removal of pesticide. Further degradation of MP was also confirmed by the appearance of p-nitrophenol in the medium after 24 hour of incubation. Thus the cyanobacterial isolate of Scytonema sp. BHUS-5 seems to be a potential bioremediation agent for the removal of organophosphorus pesticide methyl parathion from the habitat.

  17. Characterization of a fenpropathrin-degrading strain and construction of a genetically engineered microorganism for simultaneous degradation of methyl parathion and fenpropathrin.

    PubMed

    Hong, Yuanfan; Zhou, Jin; Hong, Qing; Wang, Qian; Jiang, Jiandong; Li, Shunpeng

    2010-11-01

    A gram-negative fenpropathrin-degrading bacterial strain Sphingobium sp. JQL4-5 was isolated from the wastewater treatment sludge of an insecticide factory. Strain JQL4-5 showed the ability to degrade other pyrethroid insecticides, but it was not able to degrade methyl parathion. To enhance its degrading range of substrate, a methyl parathion hydrolase gene (mpd) was successfully introduced into the chromosome of strain JQL4-5 with a mini-Tn-transposon system. A genetically engineered microorganism (GEM) named JQL4-5-mpd resulted, which was capable of simultaneously degrading methyl parathion and fenpropathrin. Soil treatment results indicated that JQL4-5-mpd is a promising multifunctional bacterium in the bioremediation of multiple pesticide-contaminated environments.

  18. Comparative analyses of genotoxicity, oxidative stress and antioxidative defence system under exposure of methyl parathion and hexaconazole in barley (Hordeum vulgare L.).

    PubMed

    Dubey, Pragyan; Mishra, Amit Kumar; Singh, Ashok Kumar

    2015-12-01

    The present study aims to evaluate the comparative effects of methyl parathion and hexaconazole on genotoxicity, oxidative stress, antioxidative defence system and photosynthetic pigments in barley (Hordeum vulgare L. variety karan-16). The seeds were exposed with three different concentrations, i.e. 0.05, 0.1 and 0.5 % for 6 h after three pre-soaking durations 7, 17 and 27 h which represents G1, S and G2 phases of the cell cycle, respectively. Ethyl methane sulphonate, a well-known mutagenic agent and double distilled water, was used as positive and negative controls, respectively. The results indicate significant decrease in mitotic index with increasing concentrations of pesticides, and the extent was higher in methyl parathion. Chromosomal aberrations were found more frequent in methyl parathion than hexaconazole as compared to their respective controls. Treatment with the pesticides induced oxidative stress which was evident with higher contents of H2O2 and lipid peroxidation, and the increase was more prominent in methyl parathion. Contents of total phenolics were increased; however, soluble protein content showed a reverse trend. Among the enzymatic antioxidants, activities of superoxide dismutase and peroxidase were significantly up-regulated, and more increase was noticed in hexaconazole. Increments in total chlorophyll and carotenoid contents were observed up to 0.1 % but decreased at higher concentration (0.5 %), and the reductions were more prominent in methyl parathion than hexaconazole as compared to their respective controls. Methyl parathion treatment caused more damage in the plant cells of barley as compared to hexaconazole, which may be closely related to higher genotoxicity and oxidative stress.

  19. Clinical coding. Code breakers.

    PubMed

    Mathieson, Steve

    2005-02-24

    --The advent of payment by results has seen the role of the clinical coder pushed to the fore in England. --Examinations for a clinical coding qualification began in 1999. In 2004, approximately 200 people took the qualification. --Trusts are attracting people to the role by offering training from scratch or through modern apprenticeships.

  20. SI PC104 Performance Test Report

    SciTech Connect

    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.

  1. A rat mammary tumor model induced by the organophosphorous pesticides parathion and malathion, possibly through acetylcholinesterase inhibition.

    PubMed Central

    Cabello, G; Valenzuela, M; Vilaxa, A; Durán, V; Rudolph, I; Hrepic, N; Calaf, G

    2001-01-01

    Environmental chemicals may be involved in the etiology of breast cancers. Many studies have addressed the association between cancer in humans and agricultural pesticide exposure. Organophosphorous pesticides have been used extensively to control mosquito plagues. Parathion and malathion are organophosphorous pesticides extensively used to control a wide range of sucking and chewing pests of field crops, fruits, and vegetables. They have many structural similarities with naturally occurring compounds, and their primary target of action in insects is the nervous system; they inhibit the release of the enzyme acetylcholinesterase at the synaptic junction. Eserine, parathion, and malathion are cholinesterase inhibitors responsible for the hydrolysis of body choline esters, including acetylcholine at cholinergic synapses. Atropine, a parasympatholytic alkaloid, is used as an antidote to acetylcholinesterase inhibitors. The aim of this study was to examine whether pesticides were able to induce malignant transformation of the rat mammary gland and to determine whether alterations induced by these substances increase the cholinergic activation influencing such transformation. These results showed that eserine, parathion, and malathion increased cell proliferation of terminal end buds of the 44-day-old mammary gland of rats, followed by formation of 8.6, 14.3, and 24.3% of mammary carcinomas, respectively, after about 28 months. At the same time, acetylcholinesterase activity decreased in the serum of these animals from 9.78 +/- 0.78 U/mL in the control animals to 3.05 +/- 0.06 U/mL; 2.57 +/- 0.15 U/mL; and 3.88 +/- 0.44 U/mL in the eserine-, parathion-, and malathion-treated groups, respectively. However, atropine alone induced a significant (p < 0.05) decrease in the acetylcholinesterase activity from the control value of 9.78 +/- 0.78 to 4.38 +/- 0.10 for atropine alone, to 1.32 +/- 0.06 for atropine in combination with eserine, and 2.39 +/- 0.29 for atropine with

  2. Urinary excretion of metabolites following a single dermal dose of [14C]methyl parathion in pregnant rats.

    PubMed

    Abu-Qare, A W; Abou-Donia, M B

    2000-09-07

    The identification and kinetics of urinary excretion of metabolites of uniformly phenyl-labeled O,O-dimethyl O-4-nitrophenyl phosphorothioate ([14C]methyl parathion) were carried out following a single dermal dose of 10.0 mg (10 microCi)/kg in pregnant Sprague-Dawley rats at 14-18 days of gestation. Urine was collected at each time interval of 1, 2, 4, 12, 24, 48, 72, and 96 h after dosing. Total p-nitrophenol in the conjugated and non-conjugated metabolites was measured as a marker of methyl parathion exposure. Elimination of radioactivity in the urine was rapid. Of the total 14C urinary excretion, 30% of the dose was excreted within 4 h, while 50 and 90% of the dose were recovered in the urine by 24 and 96 h, respectively. Excretion rate of total radioactivity was 60 microgram methyl parathion equivalent/h (1.4 mg/day). By the end of the 96-h experiment, conjugated and non-conjugated metabolites accounted for 78.1 and 21.9%, respectively. Of the non-conjugated metabolites, p-nitrophenol and O,O-dimethyl O-4-nitrophenyl phosphate (methyl paraoxon) were identified by high performance liquid chromatography (HPLC) that accounted for 20%, and 1.9% of total urinary excretion, respectively. Appearance and disappearance rate constants of p-nitrophenol in urine were 0.12 and 0.048 microgram/h, respectively. Conjugated metabolites were classified as: glucuronides 12% of urinary excretion, sulfates 3%, hot sulfuric acid hydrolysable residues 47% and 16.1% remained as unidentified water soluble metabolites. Direct hot acid hydrolysis of urine yielded 49% of extractable 14C-radioactivity compared to 62% when hot acid hydrolysis followed the enzymatic hydrolysis. The presence of the conjugated metabolites as the major class of metabolites of the total excretion indicates that determining only unbound p-nitrophenol as a biological marker for methyl parathion exposure underestimates total urinary excretion of p-nitrophenol. Sequential enzymatic and acid hydrolyses of urine prior

  3. Effects of the organophosphorus pesticide Folisuper 600 (methyl parathion) on the heart function of bullfrog tadpoles, Lithobates catesbeianus (Shaw, 1802).

    PubMed

    Costa, M J; Ribeiro, L R; Salla, R F; Gamero, F U; Alves, L M L M; Silva-Zacarin, E C M

    2015-11-01

    The aim of this work was to evaluate whether the heart function of bullfrog tadpoles (25 Gosner stage) is affected by their acute exposure (48 h) to a sub-lethal concentration (10 µg.L-1) of the active principle of the organophosphorus pesticide Folisuper 600R (methyl parathion - MP). Our results demonstrated that MP causes not only a reduction in tadpoles' cardiac ventricular mass, resulting in a marked reduction in their cardiac twitch force, but also impairs their swimming performance, irrespective of increasing their heart rate. Together, these findings indicate that low and realistic concentration of MP have a negative impact on tadpoles' performance, jeopardizing their survival.

  4. In vitro dermal absorption of methyl salicylate, ethyl parathion, and malathion: first responder safety.

    PubMed

    Moody, Richard P; Akram, Mohammed; Dickson, Eva; Chu, Ih

    2007-06-01

    In vitro tests with fresh dermatomed (0.3 to 0.4 mm thick) female breast skin and one leg skin specimen were conducted in Bronaugh flow-through Teflon diffusion cells with three chemicals used to simulate chemical warfare agents: 14C-radiolabeled methyl salicylate (MES), ethyl parathion (PT), and malathion (MT), at three dose levels (2, 20, and 200 mM). Tests were conducted at a skin temperature of 29 degrees C using a brief 30-min exposure to the chemical and a 6.5-h receivor collection period. Rapid absorption of all three chemicals was observed, with MES absorbed about 10-fold faster than PT and MT. For MES, PT, and MT, respectively, there was 32%, 7%, and 12% absorption into the receivor solution (Hank's HEPES buffered saline with 4% bovine serum albumin [BSA], pH 7.4) at the low dose (2 mM), 17%, 2%, and 3% at the medium dose (20 mM), and 11%, 1%, and 1% at the high dose (200 mM) levels. Including the skin depot for MES, PT, and MT, respectively, there was 40%, 41%, and 21% (low dose), 26%, 16%, and 8% (medium dose), and 13%, 19%, and 10% (high does) absorption. Efficacy of skin soap washing conducted at the 30 min exposure time ranged from 31% to 86%, varying by chemical and dose level. Skin depot levels were highest for the relatively lipophilic PT. "Pseudo" skin permeability coefficient (K(p)) data declined with dose level, suggesting skin saturation had occurred. An in-depth comparison with literature data was conducted and risk assessment of first responder exposure was briefly considered.

  5. Genetic damage caused by methyl-parathion in mouse spermatozoa is related to oxidative stress

    SciTech Connect

    Pina-Guzman, B.; Solis-Heredia, M.J.; Rojas-Garcia, A.E.; Uriostegui-Acosta, M.; Quintanilla-Vega, B. . E-mail: mquintan@cinvestav.mx

    2006-10-15

    Organophosphorous (OP) pesticides are considered genotoxic mainly to somatic cells, but results are not conclusive. Few studies have reported OP alterations on sperm chromatin and DNA, and oxidative stress has been related to their toxicity. Sperm cells are very sensitive to oxidative damage which has been associated with reproductive dysfunctions. We evaluated the effects of methyl-parathion (Me-Pa; a widely used OP) on sperm DNA, exploring the sensitive stage(s) of spermatogenesis and the relationship with oxidative stress. Male mice (10-12-weeks old) were administered Me-Pa (3-20 mg/kg bw/i.p.) and euthanized at 7- or 28-days post-treatment. Mature spermatozoa were obtained and evaluated for chromatin structure through SCSA (Sperm Chromatin Structure Assay; DNA Fragmentation Index parameters: Mean DFI and DFI%) and chromomycin-A{sub 3} (CMA{sub 3})-staining, for DNA damage through in situ-nick translation (NT-positive) and for oxidative stress through lipid peroxidation (LPO; malondialdehyde production). At 7-days post-treatment (mature spermatozoa when Me-Pa exposure), dose-dependent alterations in chromatin structure (Mean DFI and CMA{sub 3}-staining) were observed, as well as increased DNA damage, from 2-5-fold in DFI% and NT-positive cells. Chromatin alterations and DNA damage were also observed at 28-days post-treatment (cells at meiosis at the time of exposure); suggesting that the damage induced in spermatocytes was not repaired. Positive correlations were observed between LPO and sperm DNA-related parameters. These data suggest that oxidative stress is related to Me-Pa alterations on sperm DNA integrity and cells at meiosis (28-days post-treatment) and epididymal maturation (7-days post-treatment) are Me-Pa targets. These findings suggest a potential risk of Me-Pa to the offspring after transmission.

  6. Methyl-parathion decreases sperm function and fertilization capacity after targeting spermatocytes and maturing spermatozoa

    SciTech Connect

    Pina-Guzman, Belem; Sanchez-Gutierrez, M.; Marchetti, Francesco; Hernandez-Ochoa, I.; Solis-Heredia, M.J .; Quintanilla-Vega, B.

    2009-05-03

    Paternal germline exposure to organophosphorous pesticides (OP) has been associated with reproductive failures and adverse effects in the offspring. Methyl parathion (Me-Pa), a worldwide-used OP, has reproductive adverse effects and is genotoxic to sperm. Oxidative damage has been involved in the genotoxic and reproductive effects of OP. The purpose of this study was to determine the effects of Me-Pa on spermatozoa function and ability to fertilize. Male mice were exposed to Me-Pa (20 mg/kg bw, i.p.) and spermatozoa from epididymis-vas deferens were collected at 7 or 28 days post-treatment (dpt) to assess the effects on maturing spermatozoa and spermatocytes, respectively. DNA damage was evaluated by nick translation (NT-positive cells) and SCSA (percentDFI); lipoperoxidation (LPO) by malondialdehyde production; sperm function by spontaneous- and induced-acrosome reactions (AR); mitochondrial membrane potential (MMP) by using the JC-1 flurochrome; and, fertilization ability by an in vitro assay and in vivo mating. Results showed alterations in DNA integrity (percentDFI and NT-positive cells) at 7 and 28 dpt, in addition to decreased sperm quality and a decrease in induced-AR; reduced MMP and LPO was observed only at 7 dpt. We found negative correlations between LPO and all sperm alterations. Altered sperm functional parameters were associated with reduced fertilization rates at both times, evaluated either in vitro or in vivo. These results show that Me-Pa exposure of maturing spermatozoa and spermatocytes affects many sperm functional parameters that result in a decreased fertilizing capacity. Oxidative stress seems to be a likely mechanism ofthe detrimental effects of Me-Pa in male germ cells.

  7. Methyl-parathion decreases sperm function and fertilization capacity after targeting spermatocytes and maturing spermatozoa.

    PubMed

    Piña-Guzmán, B; Sánchez-Gutiérrez, M; Marchetti, F; Hernández-Ochoa, I; Solís-Heredia, M J; Quintanilla-Vega, B

    2009-07-15

    Paternal germline exposure to organophosphorous pesticides (OP) has been associated with reproductive failures and adverse effects in the offspring. Methyl-parathion (Me-Pa), a worldwide-used OP, has reproductive adverse effects and is genotoxic to sperm, possibly via oxidative damage. This study investigated the stages of spermatogenesis susceptible to be targeted by Me-Pa exposure that impact on spermatozoa function and their ability to fertilize. Male mice were exposed to Me-Pa (20 mg/kg bw, i.p.) and spermatozoa from epididymis-vas deferens were collected at 7 or 28 days post-treatment (dpt) to assess the effects on maturing spermatozoa and spermatocytes, respectively. Spermatozoa were examined for DNA damage by nick translation (NT-positive cells) and SCSA (%DFI), lipoperoxidation (LPO) by malondialdehyde production, sperm function by spontaneous- and induced-acrosome reactions (AR), mitochondrial membrane potential (MMP) by using the JC-1 fluorochrome, and fertilization ability by an in vitro assay and in vivo mating. Alterations on DNA integrity (%DFI and NT-positive cells) in spermatozoa collected at 7 and 28 dpt, and decreases in sperm quality and induced-AR were observed; reduced MMP and LPO were observed at 7 dpt only. Negative correlations between LPO and sperm alterations were found. Altered sperm functional parameters evaluated either in vitro or in vivo were associated with reduced fertilization rates at both times. These results show that Me-Pa exposure of maturing spermatozoa and spermatocytes affects many sperm functional parameters that result in a decreased fertilizing capacity. Oxidative stress seems to be a likely mechanism of the detrimental effects of Me-Pa exposure in male germ cells.

  8. PC/104 Embedded IOCs at Jefferson Lab

    SciTech Connect

    Jianxun Yan, Trent Allison, Sue Witherspoon, Anthony Cuffe

    2009-10-01

    Jefferson Lab has developed embedded IOCs based on PC/104 single board computers (SBC) for low level control systems. The PC/104 IOCs run EPICS on top of the RTEMS operating system. Two types of control system configurations are used in different applications, PC/104 SBC with commercial PC/104 I/O cards and PC/104 SBC with custom designed FPGA-based boards. RTEMS was built with CEXP shell to run on the PC/104 SBC. CEXP shell provides the function of dynamic object loading, which is similar to the widely used VxWorks operating system. Standard software configurations were setup for PC/104 IOC application development to provide a familiar format for new projects as well as ease the conversion of applications from VME based IOCs to PC/104 IOCs. Many new projects at Jefferson Lab are going to employ PC/104 SBCs as IOCs and some applications have already been running them for accelerator operations. The PC/104 - RTEMS IOC provides a free open source Real-Time Operating System (RTOS), low cost/maintenance, easily installed/ configured, flexible, and reliable solution for accelerator control and 12GeV Upgrade projects.

  9. Biodegradation of methyl parathion and p-nitrophenol: evidence for the presence of a p-nitrophenol 2-hydroxylase in a Gram-negative Serratia sp. strain DS001.

    PubMed

    Pakala, Suresh B; Gorla, Purushotham; Pinjari, Aleem Basha; Krovidi, Ravi Kumar; Baru, Rajasekhar; Yanamandra, Mahesh; Merrick, Mike; Siddavattam, Dayananda

    2007-01-01

    A soil bacterium capable of utilizing methyl parathion as sole carbon and energy source was isolated by selective enrichment on minimal medium containing methyl parathion. The strain was identified as belonging to the genus Serratia based on a phylogram constructed using the complete sequence of the 16S rRNA. Serratia sp. strain DS001 utilized methyl parathion, p-nitrophenol, 4-nitrocatechol, and 1,2,4-benzenetriol as sole carbon and energy sources but could not grow using hydroquinone as a source of carbon. p-Nitrophenol and dimethylthiophosphoric acid were found to be the major degradation products of methyl parathion. Growth on p-nitrophenol led to release of stoichiometric amounts of nitrite and to the formation of 4-nitrocatechol and benzenetriol. When these catabolic intermediates of p-nitrophenol were added to resting cells of Serratia sp. strain DS001 oxygen consumption was detected whereas no oxygen consumption was apparent when hydroquinone was added to the resting cells suggesting that it is not part of the p-nitrophenol degradation pathway. Key enzymes involved in degradation of methyl parathion and in conversion of p-nitrophenol to 4-nitrocatechol, namely parathion hydrolase and p-nitrophenol hydroxylase component "A" were detected in the proteomes of the methyl parathion and p-nitrophenol grown cultures, respectively. These studies report for the first time the existence of a p-nitrophenol hydroxylase component "A", typically found in Gram-positive bacteria, in a Gram-negative strain of the genus Serratia.

  10. Removal of methyl parathion from artificial off-gas using a bioreactor containing a constructed microbial consortium.

    PubMed

    Li, Lin; Yang, Chao; Lan, Wensheng; Xie, Shan; Qiao, Chuanling; Liu, Junxin

    2008-03-15

    Methyl parathion (MP), a highly toxic organophosphorus pesticide, was widely used for agriculture crop protection. During the production of MP and the process of MP-containing wastewater treatment, MP can release into the atmosphere and will do great harm to adjacent communities. A consortium comprised of an engineered microorganism and a natural p-nitrophenol (PNP) degrader was assembled for complete mineralization of MP. We genetically engineered Escherichia coli BL21 (DE3) enabling the overexpression of methyl parathion hydrolase (MPH). In addition, we isolated Ochrobactrum sp. strain LL-1 that utilized PNP, a product of MP hydrolysis, as the sole carbon, nitrogen, and energy source. The coculture effectively hydrolyzed 0.2 mM MP and prevented the accumulation of PNP in suspended culture. A laboratory-scale bioreactor containing the dual-species consortium was developed for the treatment of artificial off-gas containing MP. The bioreactor maintained over 98% of average MP removal efficiency over a 75 day period, and PNP produced from hydrolysis of MP was degraded completely, indicating that complete mineralization of MP was achieved. The strategy of linking degrading consortium to a bioreactor may provide an alternative to physicochemical abatement technologies for the treatment of waste-gas streams containing MP as well as other PNP-substituted organophosphates.

  11. Potentiometric stripping analysis of methyl and ethyl parathion employing carbon nanoparticles and halloysite nanoclay modified carbon paste electrode.

    PubMed

    Sanghavi, Bankim J; Hirsch, Gary; Karna, Shashi P; Srivastava, Ashwini K

    2012-07-20

    Carbon nanoparticles (CNPs) and halloysite nanoclay (HNC) modified carbon paste electrode (HNC-CNP-CPE) was developed for the determination of methyl parathion (MP) and ethyl parathion (EP). The electrochemical behavior of these molecules was investigated employing cyclic voltammetry (CV), chronocoulometry (CC), electrochemical impedance spectroscopy (EIS) and potentiometric stripping analysis (PSA). After optimization of analytical conditions employing this electrode at pH 5.0 in acetate buffer (0.1 M), the peak currents were found to vary linearly with its concentration in the range of 1.55×10(-9) to 3.67×10(-6) M and 1.21×10(-9) to 4.92×10(-6) M for MP and EP, respectively. The detection limits (S/N=3) of 4.70×10(-10) M and 3.67×10(-10) M were obtained for MP and EP, respectively, using PSA. The prepared modified electrode showed several advantages such as simple preparation method, high sensitivity, very low detection limits and excellent reproducibility. The proposed method was employed for the determination of MP and EP in fruits, vegetables, water and soil samples.

  12. Genetically modified microorganism Spingomonas paucimobilis UT26 for simultaneously degradation of methyl-parathion and γ-hexachlorocyclohexane.

    PubMed

    Lan, Wen S; Lu, Ti K; Qin, Zhi F; Shi, Xiu J; Wang, Jin J; Hu, Yun F; Chen, Bin; Zhu, Yi H; Liu, Zheng

    2014-07-01

    Bioremediation of pesticide residues by bacteria is an efficient and environmentally friendly method to deal with environmental pollution. In this study, a genetically modified microorganism (GMM) named UT26XEGM was constructed by introducing a parathion hydrolase gene into an initially γ-hexachlorocyclohexane (γ-HCH) degrading bacterium Spingomonas paucimobilis UT26. In order to reduce its potential risk of gene escaping into the environment for the public concern on biosafety, a suicide system was also designed that did not interfere with the performance of the GMM until its physiological function was activated by specific signal. The system was designed with circuiting suicide cassettes consisting of killing genes gef and ecoRIR from Escherichia coli controlled by Pm promoter and the xylS gene. The cell viability and original degradation characteristics were not affected by the insertion of exogenous genes. The novel GMM was capable of degrading methyl-parathion and γ-HCH simultaneously. In laboratory scale testing, the recombinant bacteria were successfully applied to the bioremediation of mixed pesticide residues with the activity of self-destruction after 3-methylbenzoate induction.

  13. Square wave voltammetric determination of methyl parathion using ZrO2-nanoparticles modified carbon paste electrode.

    PubMed

    Parham, H; Rahbar, N

    2010-05-15

    A carbon paste electrode is modified with ZrO(2)-nanoparticles and its application for square wave voltammetric (SWV) detection of methyl parathion, MP (organophosphate pesticide) is reported. The nano-ZrO(2) shows a strong affinity toward the phosphate group on methyl parathion molecules, which provides sensitivity and selectivity of the modified carbon paste electrode. Instrumental and chemical parameters influencing the voltammetric response are optimized for MP determination. Under optimum experimental conditions the peak current is linear to MP concentration over the range of 5.0-3000.0 ng mL(-1) with a correlation coefficient of 0.9992. The limit of detection (LOD) and limit of quantification (LOQ) for MP based on three and ten times the standard deviation of the blank (3S(b), 10S(b)) were 2.0 and 5.7 ng mL(-1) (n=20) for MP, respectively. The recovery values from quality control (QC) samples of water solutions containing low, middle and high concentrations of MP (50, 100 and 800 ng mL(-1)) were 98.0+/-2.3%, 92.5+/-4.9% and 97.6+/-2.8%, respectively. The electrode is successfully applied for the determination of MP in different water samples.

  14. A transposable class I composite transposon carrying mph (methyl parathion hydrolase) from Pseudomonas sp. strain WBC-3.

    PubMed

    Wei, Min; Zhang, Jun-Jie; Liu, Hong; Wang, Shu-Jun; Fu, He; Zhou, Ning-Yi

    2009-03-01

    Pseudomonas sp. strain WBC-3 utilizes methyl parathion (O,O-dimethyl O-p-nitrophenol phosphorothioate) or para-nitrophenol as the sole source of carbon, nitrogen and energy. A gene encoding methyl parathion hydrolase (MPH) had been characterized previously and found to be located on a typical class I composite transposon that comprised IS6100 (Tnmph). In this study, the transposability of this transposon was confirmed by transposition assays in two distinct mating-out systems. Tnmph was demonstrated to transpose efficiently in a random manner in Pseudomonas putida PaW340 by Southern blot and in Ralstonia sp. U2 by sequence analysis of the Tnmph insertion sites, both exhibiting MPH activity. The linkage of the mph-like gene with IS6100, together with the transposability of Tnmph, as well as its capability to transpose in other phylogenetically divergent bacterial species, suggest that Tnmph may contribute to the wide distribution of mph-like genes and the adaptation of bacteria to organophosphorus compounds.

  15. Improving the thermostability of methyl parathion hydrolase from Ochrobactrum sp. M231 using a computationally aided method.

    PubMed

    Tian, Jian; Wang, Ping; Huang, Lu; Chu, Xiaoyu; Wu, Ningfeng; Fan, Yunliu

    2013-04-01

    Good protein thermostability is very important for the protein application. In this report, we propose a strategy which contained a prediction method to select residues related to protein thermal stability, but not related to protein function, and an experiment method to screen the mutants with enhanced thermostability. The prediction strategy was based on the calculated site evolutionary entropy and unfolding free energy difference between the mutant and wild-type (WT) methyl parathion hydrolase enzyme from Ochrobactrum sp. M231 [Ochr-methyl parathion hydrolase (MPH)]. As a result, seven amino acid sites within Ochr-MPH were selected and used to construct seven saturation mutagenesis libraries. The results of screening these libraries indicated that six sites could result in mutated enzymes exhibiting better thermal stability than the WT enzyme. A stepwise evolutionary approach was designed to combine these selected mutants and a mutant with four point mutations (S274Q/T183E/K197L/S192M) was selected. The Tm and T50 of the mutant enzyme were 11.7 and 10.2 °C higher, respectively, than that of the WT enzyme. The success of this design methodology for Ochr-MPH suggests that it was an efficient strategy for enhancing protein thermostability and suitable for protein engineering.

  16. Removal of methyl parathion and tetrachlorvinphos by a bacterial consortium immobilized on tezontle-packed up-flow reactor.

    PubMed

    Yáñez-Ocampo, Gustavo; Sánchez-Salinas, Enrique; Ortiz-Hernández, M Laura

    2011-11-01

    A tezontle-packed up-flow reactor (TPUFR) with an immobilized bacterial consortium for biological treatment of methyl-parathion and tetrachlorvinphos was evaluated. These organophosphate pesticides are widely used in Mexico for insect and mite control, respectively. With the aim of developing a tool for pesticide biodegradation, four flow rates (0.936, 1.41, 2.19, and 3.51 l/h) and four hydraulic residence times (0.313, 0.206, 0.133, and 0.083 h) were evaluated in a TPUFR. In the bioreactor, with an operating time of 8 h and a flow of 0.936 l/h, we obtained 75% efficiency in the removal of methyl-parathion and tetrachlorvinphos. Their adsorptions in the volcanic rock were 9% and 6%, respectively. It was demonstrated that the removal of pesticides was due to the biological activity of the immobilized bacterial consortium. We confirmed the decrease in toxicity in the treated effluent from the bioreactor through the application of acute toxicity tests on Eisenia foetida. Immobilization of a bacterial consortium using tezontle as a support is innovative and an economical tool for the treatment of mixtures of organophosphorus pesticide residues.

  17. Rotordynamics on the PC: Further Capabilities of ARDS

    NASA Technical Reports Server (NTRS)

    Fleming, David P.

    1997-01-01

    Rotordynamics codes for personal computers are now becoming available. One of the most capable codes is Analysis of RotorDynamic Systems (ARDS) which uses the component mode synthesis method to analyze a system of up to 5 rotating shafts. ARDS was originally written for a mainframe computer but has been successfully ported to a PC; its basic capabilities for steady-state and transient analysis were reported in an earlier paper. Additional functions have now been added to the PC version of ARDS. These functions include: 1) Estimation of the peak response following blade loss without resorting to a full transient analysis; 2) Calculation of response sensitivity to input parameters; 3) Formulation of optimum rotor and damper designs to place critical speeds in desirable ranges or minimize bearing loads; 4) Production of Poincard plots so the presence of chaotic motion can be ascertained. ARDS produces printed and plotted output. The executable code uses the full array sizes of the mainframe version and fits on a high density floppy disc. Examples of all program capabilities are presented and discussed.

  18. Environmentally-friendly in situ plated bismuth-film electrode for the quantification of the endocrine disruptor parathion in skimmed milk.

    PubMed

    Gerent, Giles G; Spinelli, Almir

    2016-05-05

    An in situ bismuth-film electrode (BiFE) together with square-wave cathodic voltammetry (SWCV) was used to determine the concentration of the endocrine disruptor parathion in skimmed milk. The experimental conditions (deposition time, deposition potential and Bi (III) concentration) were optimized for the preparation of the BiFE. A glassy carbon electrode was used as the substrate. The selection of the chemical composition of the supporting electrolyte and the solution pH was aimed at improving the reduction of parathion at the BiFE surface. In addition, the parameters of the square-wave cathodic voltammetry were adjusted to improve the sensor performance. A cathodic current identified at -0.523 V increased linearly with the parathion concentration in the range of 0.2-2.0 μmol L(-1) (R=0.999). The sensitivity of the calibration curve obtained was 4.09 μA L μmol(-1), and the limits of detection (LOD) and quantification (LOQ) were 55.7 nmol L(-1) and 169.0 nmol L(-1), respectively. The performance of the sensor was tested using a sample of skimmed milk with parathion added. The same determination was carried out by UV-vis spectroscopy and the results obtained were used for the statistical evaluation of the data obtained.

  19. Development of surface imprinted core-shell nanoparticles and their application in a solid-phase dispersion extraction matrix for methyl parathion.

    PubMed

    Tan, Lei; Li, Weiming; Li, He; Tang, Youwen

    2014-04-04

    Applying molecular imprinting techniques to the surface of functionalized SiO2 allows the preparation of molecularly imprinted polymers (MIPs) with accessible, high affinity and surface exposed binding sites. This paper demonstrates a new strategy for producing such hybrid organic-inorganic surface imprinted silica nanoparticles for specific recognition of methyl parathion. The technique provides surface grafting imprinting in chloroform using amino modified silica nanoparticles as supports, acrylamide as the functional monomer, γ-methacryloxypropyl trimethoxy silane as the grafting agent, and methyl parathion as a template. The amino propyl functional monomer layer directs the selective occurrence of imprinting polymerization at the silica surface through copolymerization of grafting agents with functional monomers, but also acts as an assistive monomer to drive the template into the formed polymer shells to create effective recognition sites. The resulting MIPs-SiO2 nanoparticles display three-dimensional core-shell architectures and large surface areas. The molecularly imprinted shell provides recognition sites for methyl parathion, with the materials exhibiting excellent performance for selecting the template. Using MIPs-SiO2 nanoparticles as a matrix of solid-phase dispersion extraction sorbents, trace amounts of methyl parathion are selectivity extracted from pear and green vegetable samples while simultaneously eliminating matrix interferences, attaining recoveries of 84.7-94.4% for the samples.

  20. Neonatal parathion exposure and interactions with a high-fat diet in adulthood: Adenylyl cyclase-mediated cell signaling in heart, liver and cerebellum.

    PubMed

    Adigun, Abayomi A; Wrench, Nicola; Levin, Edward D; Seidler, Frederic J; Slotkin, Theodore A

    2010-04-05

    Organophosphates are developmental neurotoxicants but recent evidence points to additional adverse effects on metabolism and cardiovascular function. One common mechanism is disrupted cell signaling mediated through cyclic AMP, targeting neurohumoral receptors, G-proteins and adenylyl cyclase (AC) itself. Earlier, we showed that neonatal parathion evokes later upregulation of the hepatic AC pathway in adolescence but that the effect wanes by young adulthood; nevertheless metabolic changes resembling prediabetes persist. Here, we administered parathion to neonatal rats (postnatal days 1-4, 0.1 or 0.2 mg/kg/day), straddling the threshold for cholinesterase inhibition, but we extended the studies to much later, 5 months of age. In addition, we investigated whether metabolic challenge imposed by consuming a high-fat diet for 7 weeks would exacerbate neonatal parathion's effects. Parathion alone increased the expression or function of G(i), thus reducing AC responses to fluoride. Receptors controlling AC activity were also affected: beta-adrenergic receptors (betaARs) in skeletal muscle were increased, whereas those in the heart were decreased, and the latter also showed an elevation of m(2)-muscarinic acetylcholine receptors, which inhibit AC. The high-fat diet also induced changes in AC signaling, enhancing the hepatic AC response to glucagon while impairing the cardiac response to fluoride or forskolin, and suppressing betaARs and m(2)-muscarinic receptors; the only change in the cerebellum was a decrease in betaARs. Although there were no significant interactions between neonatal parathion exposure and a high-fat diet, their convergent effects on the same signaling cascade indicate that early OP exposure, separately or combination with dietary factors, may contribute to the worldwide increase in the incidence of obesity and diabetes.

  1. PC-based fault finder

    SciTech Connect

    Bengiamin, N.N. ); Jensen, C.A. . Electrical Engineering Dept. Otter Tail Power Co., Fergus Falls, MN . System Protection Group); McMahon, H. )

    1993-07-01

    Electric utilities are continually pressed to stay competitive while meeting the increasing demand of today's sophisticated customer. Advances in electron equipment and the improved array of electric driven devices are setting new standards for improved reliability and quality of service. Besides the specifications on voltage and frequency regulation and the permitted harmonic content, to name a few, the number and duration of service interruptions have a dramatic direct effect on the customer. Accurate fault locating reduces transmission line patrolling and is of particular significance in repairing long lines in rough terrain. Shortened outage times, reduced equipment degrading and stress on the system, fast restored service, and improved revenue are immediate outcomes of fast fault locating which insure minimum loss of system security. This article focuses on a PC-based (DOS) computer program that has unique features for identifying the type of fault and its location on overhead transmission/distribution lines. Balanced and unbalanced faults are identified and located accurately while accounting for changes in conductor sizes and network configuration. The presented concepts and methodologies have been spurred by Otter Tail Power's need for an accurate fault locating scheme to accommodate multiple feeders with mixed lone configurations. A case study based on a section of the Otter Tail network is presented to illustrate the features and capabilities of the developed software.

  2. Identification of mechanisms involved in the acute airway toxicity induced by parathion.

    PubMed

    Segura, P; Chávez, J; Montaño, L M; Vargas, M H; Delaunois, A; Carbajal, V; Gustin, P

    1999-12-01

    Organophosphates are still widely used worldwide and cause thousands of intoxications every year. In this work we investigated the mechanisms of parathion (Pth) airway toxicity, using biochemical and functional approaches. A plethysmographic technique for unrestrained guinea pigs was used to analyze Pth-induced modifications of airway mechanics and responsiveness to acetylcholine (ACh: 0.1-3.2 mg/ml, 2-min inhalation each dose). The isolated perfused rabbit lung preparation was used to study the acute effects of Pth on airway responsiveness to ACh (10(-8)-10(-3) M), histamine (10(-8)-10(-3) M) and substance P (10(-10)-10(-6) M), pulmonary acetylcholinesterase inhibition and cytochrome P450 (P450) activity, and their modifications with previous administration of Pth (1 mg/kg s.c. daily, 7 days). We found that: (1) In guinea pigs Pth (3.2-17 mg/kg i.p.) produced a dose-dependent increase in a lung resistance index (iRL), which was greatly reverted (approximately 50%) by salbutamol (2 mg/ml, 2-min inhalation, or 10 microg/kg i.p.). This salbutamol effect was transient (5-10 min), suggesting that this bronchodilator triggered additional obstructive mechanisms. (2) Pth increased the water content in lung parenchyma samples, but not in trachea or bronchi, and augmented the respiratory secretions measured through monosaccharide content in bronchoalveolar lavage. (3) The increase in iRL was greater in female animals, probably due to a higher P450 basal activity, and completely blocked by pharmacological inhibition of P450 with piperonyl butoxide (500 mg/kg i.p.). (4) In male guinea pigs a subclinical dose of Pth (10 mg/kg i.p.) induced airway hyperresponsiveness to ACh. In isolated perfused rabbit lung Pth (10(-6) M) produced airway hyperresponsiveness to ACh and histamine, the latter prevented by atropine (10(-5) M). (5) Repetitive exposure to subclinical doses (1 mg/kg s.c.) of Pth during 1 week caused approximately 80% inhibition of P450 activity in rabbits, which was

  3. Computation of USGS Soil UHS and Comparison to NEHRP and PC 1 Seismic Response

    SciTech Connect

    Lee, R.C.

    2000-04-26

    Recently, new site-specific seismic design response spectra were developed for Savannah River Site (SRS) performance category (PC) 1,2,3 and 4 structures, systems and components (SSCs) (WSRC, 1997, 1998) in accordance with DOE Standards. The lower performance categories (PC1 and PC2) site-specific design basis were not compatible with the response spectrum generated if building code guidelines were used (National Earthquake Hazard Reduction Program Recommended Provisions for Seismic Regulations for New Building, (NEHRP), 1997). These differences in criteria and approach should be documented and understood. Thus, Westinghouse Savannah River Company (WSRC) initiated this study to evaluate the difference between the building code hazard assessment (NEHRP) and the site-specific hazard evaluations used for SRS design.

  4. Ethical coding.

    PubMed

    Resnik, Barry I

    2009-01-01

    It is ethical, legal, and proper for a dermatologist to maximize income through proper coding of patient encounters and procedures. The overzealous physician can misinterpret reimbursement requirements or receive bad advice from other physicians and cross the line from aggressive coding to coding fraud. Several of the more common problem areas are discussed.

  5. Determination of Parathion and Carbaryl Pesticides in Water and Food Samples Using a Self Assembled Monolayer/Acetylcholinesterase Electrochemical Biosensor

    PubMed Central

    Pedrosa, Valber A.; Caetano, Josiane; Machado, Sergio A. S.; Bertotti, Mauro

    2008-01-01

    An acetylcholinesterase (AchE) based amperometric biosensor was developed by immobilisation of the enzyme onto a self assembled modified gold electrode. Cyclic voltammetric experiments performed with the SAM-AchE biosensor in phosphate buffer solutions (pH = 7.2) containing acetylthiocholine confirmed the formation of thiocholine and its electrochemical oxidation at Ep = 0.28 V vs Ag/AgCl. An indirect methodology involving the inhibition effect of parathion and carbaryl on the enzymatic reaction was developed and employed to measure both pesticides in spiked natural water and food samples without pre-treatment or pre-concentration steps. Values higher than 91-98.0% in recovery experiments indicated the feasibility of the proposed electroanalytical methodology to quantify both pesticides in water or food samples. HPLC measurements were also performed for comparison and confirmed the values measured amperometrically. PMID:27873775

  6. Impaired brain StAR and HSP70 gene expression in zebrafish exposed to Methyl-Parathion based insecticide.

    PubMed

    da Rosa, João Gabriel Santos; Koakoski, Gessi; Piato, Angelo L; Bogo, Maurício Reis; Bonan, Carla Denise; Barcellos, Leonardo José Gil

    2016-01-01

    Fish production ponds and natural water body areas located in close proximity to agricultural fields receive water with variable amounts of agrochemicals, and consequently, compounds that produce adverse effects may reach nontarget organisms. The aim of this study was to investigate whether waterborne methyl-parathion-based insecticide (MPBI) affected gene expression patterns of brain glucocorticoid receptor (GR), steroidogenic acute regulatory protein (StAR), and heat shock protein 70 (hsp70) in adult zebrafish (Danio rerio) exposed to this chemical for 96 h. Treated fish exposed to MPBI-contaminated water showed an inhibition of brain StAR and hsp70 gene expression. Data demonstrated that MPBI produced a decrease brain StAR and hsp70 gene expression.

  7. Simultaneous biodegradation of methyl parathion and carbofuran by a genetically engineered microorganism constructed by mini-Tn5 transposon.

    PubMed

    Jiang, Jiandong; Zhang, Ruifu; Li, Rong; Gu, Ji-Dong; Li, Shunpeng

    2007-08-01

    A genetically engineered microorganism (GEM) capable of simultaneous degrading methyl parathion (MP) and carbofuran was successfully constructed by random insertion of a methyl parathion hydrolase gene (mpd) into the chromosome of a carbofuran degrading Sphingomonas sp. CDS-1 with the mini-transposon system. The GEM constructed was relatively stable and cell viability and original degrading characteristic was not affected compared with the original recipient CDS-1. The effects of temperature, initial pH value, inoculum size and alternative carbon source on the biodegradation of MP and carbofuran were investigated. GEM cells could degrade MP and carbofuran efficiently in a relatively broad range of temperatures from 20 to 30 degrees C, initial pH values from 6.0 to 9.0, and with all initial inoculation cell densities (10(5)-10(7) CFU ml(-1)), even if alternative glucose existed. The optimal temperature and initial pH value for GEM cells to simultaneously degrade MP and carbofuran was at 30 degrees C and at pH 7.0. The removal of MP and carbofuran by GEM cells in sterile and non-sterile soil were also studied. In both soil samples, 50 mg kg(-1) MP and 25 mg kg(-1) carbofuran could be degraded to an undetectable level within 25 days even if there were indigenous microbial competition and carbon sources effect. In sterile soil, the biodegradation rates of MP and carbofuran were faster, and the decline of the inoculated GEM cells was slower compared with that in non-sterile soil. The GEM constructed in this study was potential useful for pesticides bioremediation in natural environment.

  8. DIGLIB. PC-DOS Graphics Subroutine Library

    SciTech Connect

    Burleson, R.R.

    1989-02-01

    DIGLIB is a collection of general graphics subroutines. It was designed to be small, reasonably fast, device-independent, and compatible with DEC-supplied operating systems for VAXes, PDP-11s, and LSI-11s, and the DOS operating system for IBM PCs and IBM-compatible machines. DIGLIB/PC runs on IBM PCs under PC-DOS or MS-DOS. The software is readily usable by casual programmers for two-dimensional plotting.

  9. Studies on combined effects of organophosphates or carbamates and morsodren in birds. II. Plasma and cholinesterase in quail fed morsodren and orally dosed with parathion or carbofuran

    USGS Publications Warehouse

    Dieter, M.P.; Ludke, J.L.

    1978-01-01

    The degree of interaction between mercury and cholinesterase inhibiting pesticides was determined by comparing enzyme responses to sublethal dosages of parathion or carbofuran in quail fed 0.05, 0.5, or 5.0 ppm morsodren for 18 weeks. A statistically significant interaction was defined as greater brain cholinesterase inhibition in morsodren-fed than in clean-fed birds following pesticide dosage. The tissue residues of mercury that accumulated before significant mercury-parathion interactions occurred were higher than levels that might be expected in natural populations, but significant mercury-carbofuran interactions occurred in birds that had only accumulated 1.0 ppm liver mercury. The results indicate that indiscriminate usage of cholinesterase inhibiting pesticides are dangerous, since natural populations of fish-eating birds oftentimes contain this magnitude of mercury.

  10. Sharing code.

    PubMed

    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.

  11. Neonatal Parathion Exposure and Interactions with a High-Fat Diet in Adulthood: Adenylyl Cyclase-Mediated Cell Signaling in Heart, Liver and Cerebellum

    PubMed Central

    Adigun, Abayomi A.; Wrench, Nicola; Levin, Edward D.; Seidler, Frederic J.; Slotkin, Theodore A.

    2010-01-01

    Organophosphates are developmental neurotoxicants but recent evidence points to additional adverse effects on metabolism and cardiovascular function. One common mechanism is disrupted cell signaling mediated through cyclic AMP, targeting neurohumoral receptors, G-proteins and adenylyl cyclase (AC) itself. Earlier, we showed that neonatal parathion evokes later upregulation of the hepatic AC pathway in adolescence but that the effect wanes by young adulthood; nevertheless metabolic changes resembling prediabetes persist. Here, we administered parathion to neonatal rats (postnatal days 1-4, 0.1 or 0.2 mg/kg/day), straddling the threshold for cholinesterase inhibition, but we extended the studies to much later, 5 months of age. In addition, we investigated whether metabolic challenge imposed by consuming a high-fat diet for 7 weeks would exacerbate neonatal parathion’s effects. Parathion alone increased the expression or function of Gi, thus reducing AC responses to fluoride. Receptors controlling AC activity were also affected: β-adrenergic receptors (βARs) in skeletal muscle were increased, whereas those in the heart were decreased, and the latter also showed an elevation of m2-muscarinic acetylcholine receptors, which inhibit AC. The high-fat diet also induced changes in AC signaling, enhancing the hepatic AC response to glucagon while impairing the cardiac response to fluoride or forskolin, and suppressing βARs and m2-muscarinic receptors; the only change in the cerebellum was a decrease in βARs. Although there were no significant interactions between neonatal parathion exposure and a high-fat diet, their convergent effects on the same signaling cascade indicate that early OP exposure, separately or combination with dietary factors, may contribute to the worldwide increase in the incidence of obesity and diabetes. PMID:20074626

  12. Determination of benomyl, diphenyl, o-phenylphenol, thiabendazole, chlorpyrifos, methidathion, and methyl parathion in oranges by solid-phase extraction, liquid chromatography, and gas chromatography.

    PubMed

    Yamazaki, Y; Ninomiya, T

    1999-01-01

    A simple and rapid method was developed for determination of benomyl, diphenyl (DP), o-phenylphenol (OPP), thiabendazole (TBZ), chlorpyrifos, methidathion, and methyl parathion in whole oranges. These compounds were extracted from a mixture of samples and anhydrous sodium acetate with ethyl acetate. The ethyl acetate extract was concentrated and cleaned up by passing through tandem solid-phase extraction columns consisting of anion-exchange and primary/secondary amine bonded silica. The eluate was concentrated and volume was adjusted with methanol for subsequent liquid chromatography (LC) and gas chromatography (GC). Benomyl (as methyl-2-benzimidazole carbamate, MBC), DP, OPP, and TBZ residues were determined by LC with fluorescence detection. Recoveries at 3 fortified levels (0.1, 1, and 10 micrograms/g) ranged from 63.9 to 97.4%, with coefficients of variation (CVs) of 1.6 to 15.5%. Limits of detection (LODs) were 0.01 microgram/g for DP, OPP, TBZ and 0.05 microgram/g for benomyl. Chlorpyrifos, methidathion, and methyl parathion residues were determined by GC with flame photometric detection. Recoveries ranged from 90.4 to 97.0%, with CVs of 2.1 to 5.9%. LODs were 0.005 microgram/g for chlorpyrifos and methyl parathion, and 0.01 microgram/g for methidathion.

  13. Parathion, a cholinesterase-inhibiting plaguicide induces changes in tertiary villi of placenta of women exposed: a scanning electron microscopy study.

    PubMed

    Levario-Carrillo, M; Feria-Velasco, A; De Celis, R; Ramos-Martínez, E; Córdova-Fierro, L; Solís, F J

    2001-01-01

    The objective of this work was to describe the anatomy of placentas from women who were at risk of exposure to parathion during their pregnancy, when examined with the light and scanning electron microscopes. Twenty term placentas were analyzed; 10 from women living in an agricultural area, who were at risk of exposure to parathion during their pregnancy, and 10 from women living in an urban area, not expressly exposed to pesticides. Each sample was examined with both light and scanning electron microscopes. Cholinesterase activity was significantly reduced in blood from women of the exposed group. In some placentas of women exposed to parathion, recent microinfarctions, microcalcifications and increased deposition of fibrinoid material were seen, along with a larger proportion of atypical characteristics of villi, such as bullous and balloon-like formations with nonhomogeneous surface, and other areas devoid of microvilli. These observations suggest that in chronic exposure to pesticides, the rate of atypical characteristics of placental villi increases, which could be related to changes in the fetus biology. In this study, one newborn from the exposed group showed intrauterine growth retardation and another one, some signs of hypoxia.

  14. Cloning of the organophosphorus pesticide hydrolase gene clusters of seven degradative bacteria isolated from a methyl parathion contaminated site and evidence of their horizontal gene transfer.

    PubMed

    Zhang, Ruifu; Cui, Zhongli; Zhang, Xiaozhou; Jiang, Jiandong; Gu, Ji-Dong; Li, Shunpeng

    2006-10-01

    Seven organophosphorus pesticide-degrading bacteria harboring the methyl parathion degrading (mpd) gene were isolated from a methyl parathion contaminated site. In this study, the 4.7 kb mpd gene cluster, conserved in all seven bacteria capable of degrading methyl parathion, was cloned and further analysis revealed that this cluster contained five ORFs and the mpd gene was associated with a mobile element, IS6100. In addition to mpd gene ORF and tnpA ORF, three other ORFs showed high homology to the permease component of ABC-type transport system, the general secretion pathway protein B, and the RNA polymerase sigma 70 factor, respectively. The mpd genes of these 7 strains were subcloned and expressed in E. coli, SDS-PAGE and zymogram analysis showed that two expression products of mpd genes in E. coli were found, but the one without signal peptide showed the hydrolytic activities. Our evidences collectively suggest that mpd gene cluster may be disseminated through horizontal gene transfer based on phylogenetic analysis of the cluster and their host bacterial strains, and comparisons of GC content of the cluster and respective host's chromosome.

  15. Construction of an engineered strain free of antibiotic resistance gene markers for simultaneous mineralization of methyl parathion and ortho-nitrophenol.

    PubMed

    Liu, Yan; Wei, Qing; Wang, Shu-Jun; Liu, Hong; Zhou, Ning-Yi

    2010-06-01

    Pseudomonas sp. strain NyZ402, a native soil organism that grows on para-nitrophenol (PNP), was genetically engineered for the simultaneous degradation of methyl parathion (MP) and ortho-nitrophenol (ONP) by integrating mph (methyl parathion hydrolase gene) from Pseudomonas sp. strain WBC-3 and onpAB (ONP 2-monooxygenase and ONP o-benzoquinone reductase genes) from Alcaligenes sp. strain NyZ215 into the genome of strain NyZ402. Methyl parathion hydrolase (MPH), ONP 2-monooxygenase (OnpA) and o-benzoquinone reductase (OnpB) were constitutively expressed in the engineered strain NyZ-MO. Strain NyZ-MO was free of exogenous antibiotic resistance gene markers and the introduced genes were genetically stable. Degradation experiments showed that strain NyZ-MO could utilize MP or ONP as the sole carbon and energy source, and mineralize 0.1 mM MP-0.1 mM ONP simultaneously. This method may serve as a useful strategy for the construction of engineered strains in the degradation of multiple environmental pollutants.

  16. The vital function of Fe3O4@Au nanocomposites for hydrolase biosensor design and its application in detection of methyl parathion.

    PubMed

    Zhao, Yuting; Zhang, Weiying; Lin, Yuehe; Du, Dan

    2013-02-07

    A nanocomposite of gold nanoparticles (AuNPs) decorating a magnetic Fe(3)O(4) core was synthesized using cysteamine (SH-NH(2)) as linker, and characterized by TEM, XPS, UV and electrochemistry. Then a hydrolase biosensor, based on self-assembly of methyl parathion hydrolase (MPH) on the Fe(3)O(4)@Au nanocomposite, was developed for sensitive and selective detection of the organophosphorus pesticide (OP) methyl parathion. The magnetic nanocomposite provides an easy way to construct the enzyme biosensor by simply exerting an external magnetic field, and also provides a simple way to renew the electrode surface by removing the magnet. Unlike inhibition-based enzyme biosensors, the hydrolase is not poisoned by OPs and thus is reusable for continuous measurement. AuNPs not only provide a large surface area, high loading efficiency and fast electron transfer, but also stabilize the enzyme through electrostatic interactions. The MPH biosensor shows rapid response and high selectivity for detection of methyl parathion, with a linear range from 0.5 to 1000 ng mL(-1) and a detection limit of 0.1 ng mL(-1). It also shows acceptable reproducibility and stability. The simplicity and ease of operation of the proposed method has great potential for on-site detection of P-S containing pesticides and provides a promising strategy to construct a robust biosensor.

  17. The Vital Function of Fe3O4@Au nanocomposites for Hydrolase Biosensor Design and Its Application in Detection of Methyl Parathion

    SciTech Connect

    Zhao, Yuting; Zhang, Weiying; Lin, Yuehe; Du, Dan

    2013-02-04

    A nanocomposite of gold nanoparticles (AuNPs) decorating a magnetic Fe3O4 core was synthesized using cysteamine (SH–NH2) as linker, and characterized by TEM, XPS, UV and electrochemistry. Then a hydrolase biosensor, based on self-assembly of methyl parathion hydrolase (MPH) on the Fe3O4@Au nanocomposite, was developed for sensitive and selective detection of the organophosphorus pesticide (OP) methyl parathion. The magnetic nanocomposite provides an easy way to construct the enzyme biosensor by simply exerting an external magnetic field, and also provides a simple way to renew the electrode surface by removing the magnet. Unlike inhibition-based enzyme biosensors, the hydrolase is not poisoned by OPs and thus is reusable for continuous measurement. AuNPs not only provide a large surface area, high loading efficiency and fast electron transfer, but also stabilize the enzyme through electrostatic interactions. The MPH biosensor shows rapid response and high selectivity for detection of methyl parathion, with a linear range from 0.5 to 1000 ng/mL and a detection limit of 0.1 ng/mL. It also shows acceptable reproducibility and stability. The simplicity and ease of operation of the proposed method has great potential for on-site detection of P–S containing pesticides and provides a promising strategy to construct a robust biosensor.

  18. Adapting PC104Plus for Space

    NASA Technical Reports Server (NTRS)

    Abbott, Larry; Cox, Gary; Nguyen, Hai

    2000-01-01

    This article addresses the issues associated with adapting the commercial PC104Plus standard and its associated architecture to the requirements of space applications. In general, space applications exhibit extreme constraints on power, weight, and volume. EMI and EMC are also issues of significant concern. Additionally, space applications have to survive high radiation environment. Finally, NASA is always concerned about achieving cost effective solutions that are compatible with safety and launch constraints. Weight and volume constraints are directly related to high launch cost. Power on the other hand is not only related to the high launch costs, but are related to the problem of dissipating the resulting heat once in space. The article addresses why PC104Plus is an appropriate solution for the weight and volume issues. The article also addresses what NASA did electrically to reduce power consumption and mechanically dissipate the associated heat in a microgravity and vacuum environment, and how these solutions allow NASA to integrate various sizes of ruggedized custom PC104 boards with COTS, PC104 complaint boards for space applications. In addition to the mechanical changes to deal with thermal dissipation NASA also made changes to minimize EMI. Finally, radiation issues are addressed as well as the architectural and testing solutions and the implications for use of COTS PC104Plus boards.

  19. Collaborative Simulation Grid: Multiscale Quantum-Mechanical/Classical Atomistic Simulations on Distributed PC Clusters in the US and Japan

    NASA Technical Reports Server (NTRS)

    Kikuchi, Hideaki; Kalia, Rajiv; Nakano, Aiichiro; Vashishta, Priya; Iyetomi, Hiroshi; Ogata, Shuji; Kouno, Takahisa; Shimojo, Fuyuki; Tsuruta, Kanji; Saini, Subhash; Biegel, Bryan (Technical Monitor)

    2002-01-01

    A multidisciplinary, collaborative simulation has been performed on a Grid of geographically distributed PC clusters. The multiscale simulation approach seamlessly combines i) atomistic simulation backed on the molecular dynamics (MD) method and ii) quantum mechanical (QM) calculation based on the density functional theory (DFT), so that accurate but less scalable computations are performed only where they are needed. The multiscale MD/QM simulation code has been Grid-enabled using i) a modular, additive hybridization scheme, ii) multiple QM clustering, and iii) computation/communication overlapping. The Gridified MD/QM simulation code has been used to study environmental effects of water molecules on fracture in silicon. A preliminary run of the code has achieved a parallel efficiency of 94% on 25 PCs distributed over 3 PC clusters in the US and Japan, and a larger test involving 154 processors on 5 distributed PC clusters is in progress.

  20. Down-regulation of muscarinic receptors and the m3 subtype in white-footed mice by dietary exposure to parathion

    USGS Publications Warehouse

    Jett, D.A.; Hill, E.F.; Fernando, J.C.; Eldefrawi, M.E.; Eldefrawi, A.T.

    1993-01-01

    The effect of ad libitum dietary exposure (as occurs in the field) to parathion for 14 d was investigated on the muscarinic acetylcholine receptor (mAChR) in brains and submaxillary glands of adults of a field species, the white-footed mouse Peromyscus leucopus. Immunoprecipitation using subtype selective antibodies revealed that the relative ratios of the m1-m5 mAChR subtypes in Peromyscus brain were similar to those in rat brain. There was little variability in acetylcholinesterase (AChE) activity in control mice brains but large variability in 39 exposed mice, resulting from differences in food ingestion and parathion metabolism. Accordingly, data on radioligand binding to mAChRs in each mouse brain were correlated with brain AChE activity in the same mouse, and AChE inhibition served as a biomarker of exposure reflecting in situ paraoxon concentrations. Exposure to parathion for 14 d reduced maximal binding (Bmax) of [3H]quinuclidinyl benzilate ([3H]QNB), [3H]-N-methylscopolamine ([3H]NMS), and [3H]-4-diphenylacetoxy-N-methylpiperidine methiodide ([3H]-4-DAMP) by up to approximately 58% without affecting receptor affinities for these ligands. Maximal reduction in Bmax of [3H]QNB and [3H]-4-DAMP binding occurred in mice with highest AChE inhibition, while equivalent maximal reduction in Bmax of [3H]NMS occurred in mice with only approximately 10% AChE inhibition, without further change at higher parathion doses. This is believed to be due to the hydrophilicity of [3H]NMS, which limits its accessibility to internalized desensitized receptors. In submaxillary glands (mAChRs are predominantly m3 subtype), there were significant dose-dependent reductions in [3H]QNB binding and m3 mRNA levels in exposed mice, revealed by Northern blot analyses. The reduction in m3 receptors is suggested to result mostly from reduced synthesis at the transcription level, rather than from translational or posttranslational events. The data suggest that down-regulation of mAChRs occurs

  1. Broad spectral sensitivity and improved efficiency in CuPc/Sub-Pc organic photovoltaic devices

    NASA Astrophysics Data System (ADS)

    Kumar, Hemant; Kumar, Pankaj; Bhardwaj, Ramil; Sharma, G. D.; Chand, Suresh; Jain, S. C.; Kumar, Vikram

    2009-01-01

    We demonstrate organic photovoltaic devices incorporating two donors, namely, copper phthalocyanine (CuPc) and boron sub-phthalocyanine chloride (Sub-Pc) in association with single acceptor fullerene (C60) with sensitivity extending across the visible solar spectrum. It has been found that the absorption in different spectral regions in CuPc and Sub-Pc results in efficient harvesting of incident light photons which leads to enhanced power conversion efficiency (η). An enhancement in η from 0.64%, in the device architecture indium-tin-oxide (ITO)/CuPc(20 nm)/C60(40 nm)/bathophenanthroline (BPhen) (8 nm)/Al(150 nm), to ~1.3% in the optimized device having a 2 nm layer of Sub-Pc in the geometry ITO/CuPc(18 nm)/Sub-Pc(2 nm)/C60 (40 nm)/BPhen (8 nm)/Al(150 nm) has been observed. This enhancement in η is dominantly attributed to the increment in short circuit current density (Jsc) due to efficient photon harvesting by incorporation of dual donors.

  2. The IBM PC at NASA Ames

    NASA Technical Reports Server (NTRS)

    Peredo, James P.

    1988-01-01

    Like many large companies, Ames relies very much on its computing power to get work done. And, like many other large companies, finding the IBM PC a reliable tool, Ames uses it for many of the same types of functions as other companies. Presentation and clarification needs demand much of graphics packages. Programming and text editing needs require simpler, more-powerful packages. The storage space needed by NASA's scientists and users for the monumental amounts of data that Ames needs to keep demand the best database packages that are large and easy to use. Availability to the Micom Switching Network combines the powers of the IBM PC with the capabilities of other computers and mainframes and allows users to communicate electronically. These four primary capabilities of the PC are vital to the needs of NASA's users and help to continue and support the vast amounts of work done by the NASA employees.

  3. CAP88-PC Version 4, an updated radionuclide NESHAPS model.

    PubMed

    Wood, Raymond; Stuenkel, David; Rosnick, Reid

    2013-08-01

    The latest version of the CAP88-PC computer model, Version 4, has many changes and improvements from previous versions. The most significant of these changes from a user perspective are the incorporation of age-dependent radionuclide dose and risk factors for ingestion and inhalation, the increase in the number of included radionuclides, and a change in the file management system used by the program. Other changes less visible to the user include new code architecture, incorporation of numerical solvers for the calculation of radioactive decay chains, including the ingrowth of decay products during air transport and ground surface deposition, enhanced error messages, updated on-line help, and a utility for migrating Version 3 datasets, wind files, and population files to Version 4. The modifications have produced a significant improvement in speed and stability for Version 4 relative to Version 3 and eliminated the solution approximations used in Version 3. The U.S. Environmental Protection Agency has implemented an extensive testing and documentation program for CAP88-PC Version 4 to address user concerns with past versions, resulting in enhanced documentation supporting compatibility with user software quality assurance programs.

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

    NASA Technical Reports Server (NTRS)

    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?

  5. Sharing code

    PubMed Central

    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. PMID:25165519

  6. User's guide to the Personal Computer version of the Biogenic Emissions Inventory System (PC-BEIS)

    SciTech Connect

    Pierce, T.E.; Baugues, K.A.

    1991-07-01

    The Personal Computer version of the Biogenic Emissions Inventory System (PC-BEIS) has been developed to allow users to estimate hourly emissions of biogenic non-methane hydrocarbon emissions for any county in the contiguous United States. PC-BEIS has been compiled using Microsoft FORTRAN and tested on IBM-compatible personal computers. The source code was written in ANSI FORTRAN 77 and should be transportable to most other computers. Emission rates depend on land use, leaf biomass, and emission factors. PC-BEIS also includes adjustments due to temperature and sunglight. A simple leaf energy balance module is included to allow more refined calculations of leaf temperature and sunlight through forest canopies. The user's guide briefly describes the technical background, provides an overview of computer aspects, and shows an example test case.

  7. Mathematics Instruction and the Tablet PC

    ERIC Educational Resources Information Center

    Fister, K. Renee; McCarthy, Maeve L.

    2008-01-01

    The use of tablet PCs in teaching is a relatively new phenomenon. A cross between a notebook computer and a personal digital assistant (PDA), the tablet PC has all of the features of a notebook with the additional capability that the screen can also be used for input. Tablet PCs are usually equipped with a stylus that allows the user to write on…

  8. Jargon that Computes: Today's PC Terminology.

    ERIC Educational Resources Information Center

    Crawford, Walt

    1997-01-01

    Discusses PC (personal computer) and telecommunications terminology in context: Integrated Services Digital Network (ISDN); Asymmetric Digital Subscriber Line (ADSL); cable modems; satellite downloads; T1 and T3 lines; magnitudes ("giga-,""nano-"); Central Processing Unit (CPU); Random Access Memory (RAM); Universal Serial Bus…

  9. Multitasking Operating Systems for the IBM PC.

    ERIC Educational Resources Information Center

    Owen, G. Scott

    1985-01-01

    The ability of a microcomputer to execute several programs at the same time is called "multitasking." The nature and use of one multitasking operating system Concurrent PC-DOS from Digital Research (the developers of the CP/M operating system) are discussed. (JN)

  10. Combating adverse selection in secondary PC markets.

    PubMed

    Hickey, Stewart W; Fitzpatrick, Colin

    2008-04-15

    Adverse selection is a significant contributor to market failure in secondary personal computer (PC) markets. Signaling can act as a potential solution to adverse selection and facilitate superior remarketing of second-hand PCs. Signaling is a means whereby usage information can be utilized to enhance consumer perception of both value and utility of used PCs and, therefore, promote lifetime extension for these systems. This can help mitigate a large portion of the environmental impact associated with PC system manufacture. In this paper, the computer buying and selling behavior of consumers is characterized via a survey of 270 Irish residential users. Results confirm the existence of adverse selection in the Irish market with 76% of potential buyers being unwilling to purchase and 45% of potential vendors being unwilling to sell a used PC. The so-called "closet affect" is also apparent with 78% of users storing their PC after use has ceased. Results also indicate that consumers place a higher emphasis on specifications when considering a second-hand purchase. This contradicts their application needs which are predominantly Internet and word-processing/spreadsheet/presentation applications, 88% and 60% respectively. Finally, a market solution utilizing self monitoring and reporting technology (SMART) sensors for the purpose of real time usage monitoring is proposed, that can change consumer attitudes with regard to second-hand computer equipment.

  11. PC Kiosk Trends in Rural India

    ERIC Educational Resources Information Center

    Toyama, Kentaro; Kiri, Karishma; Menon, Deepak; Sethi, Suneet; Pal, Joyojeet; Srinivasan, Janaki

    2006-01-01

    This article presents a series of preliminary, quantitative results on rural PC kiosks in India. An analysis of the data confirms many expected trends and correlations and shows that kiosks still face the challenge of sustainability as a business. This study is based on questionnaires presented to kiosk operators and customers of kiosks operated…

  12. Experience in setting up a PC cluster

    NASA Astrophysics Data System (ADS)

    Lin, Ganghua; Zhang, Mei

    2004-09-01

    In this paper we summary and present our thinking and experience in setting up a PC cluster, with a consideration that the described thinking and experience may be relevant to or useful for those who intend to buy a similar cluster in the near future.

  13. Stretch Your PC Dollars--Buy Clones.

    ERIC Educational Resources Information Center

    True, John

    1986-01-01

    Relates how the story of how San Francisco State University evaluated IBM PC look-alikes, considered some of the risks involved, and decided to purchase over 100 of them. Questions of compatibility, vendor longevity, support, and other risk management issues are discussed. (Author/MLW)

  14. Brain acetylcholinesterase activity recovery following acute methyl parathion intoxication in two feral rodent species: comparison to laboratory rodents

    SciTech Connect

    Roberts, D.K.; Silvey, N.J.; Bailey, E.M. Jr.

    1988-07-01

    Widespread use of organophosphorus insecticides (OPs) has produced both acute and chronic intoxication among nontarget organisms. Most such studies have included fish and birds as opposed to mammals. However, numerous OP toxicity studies have been conducted on laboratory rodents creating a temptation to apply this data to feral rodents. Chronic OP exposure has been reported to produce cholinergic adaptation which in turn lowers mortality rates following a subsequent acute anticholinesterase exposure. The relevance that these laboratory rodent studies have on feral rodents is subject to debate. Field studies involving OP exposure among nontarget feral mammals have produced contradictory results. Increased mortality as a result of repeated OP application has been reported. This observation may be of considerable importance to nontarget feral rodent populations due to the repetitive nature of OP application protocols. The ability of feral rodents to recover brain AChE activity (BAA) between OP application intervals undoubtedly promotes their survival. This study investigated and compared BAA recovery following acute oral methyl parathion intoxication among 2 feral rodent species and among 2 common laboratory rodent species.

  15. Entrapment of methyl parathion hydrolase in cross-linked poly(γ-glutamic acid)/gelatin hydrogel.

    PubMed

    Xie, Jianfei; Zhang, Huiwen; Li, Xu; Shi, Yuanliang

    2014-02-10

    Methyl parathion hydrolase (MPH) is an important enzyme in hydrolyzing toxic organophosphorus (OP) compounds. However, MPH is easily deactivated when subjected to extreme environmental conditions and is difficult to recover from the reaction system for reuse, thereby limiting its practical application. To address these shortcomings, we examined the entrapment of MPH in an environment-friendly, biocompatible and biodegradable cross-linked poly(γ-glutamic acid)/gelatin hydrogel. The cross-linked poly(γ-glutamic acid)/gelatin hydrogels were prepared with different gelatin/poly(γ-glutamic acid) mass ratios using water-soluble carbodiimide as the cross-linking agent. The MPH-entrapped cross-linked poly(γ-glutamic acid)/gelatin hydrogel (CPE-MPH) not only possessed improved thermostability, pH stability, and reusability but also exhibited enhanced efficiency in hydrolyzing OP compounds. Furthermore, CPE-MPH possesses high water-absorbing and water-retaining capabilities. We believe that the cross-linked poly(γ-glutamic acid)/gelatin hydrogels are an attractive carrier for the entrapment of diverse enzymes, affording a new approach for enzyme entrapment.

  16. Bioaccumulation of methyl parathion and its toxicology in several species of the freshwater community in Ignacio Ramirez dam in Mexico.

    PubMed

    De La Vega Salazar, M Y; Tabche, L M; García, C M

    1997-10-01

    Environmental contamination by pesticides, including the presence of chemical residues in aquatic wildlife, is a widespread ecological problem. Methyl parathion (MP), a widely used organophosphorate insecticide, is a potent neurotoxic in both vertebrates and invertebrates. The effect of a subchronic exposure to MP in aquatic organisms was evaluated in a natural ecosystem measuring acetyl cholinesterase (AChE) and gamma glutamil transpeptidase (GGT) activity. Two samples were conducted. Physicochemical characterization was done at each sampling time and organisms were collected. MP and metabolite 4-nitrophenol (4-NP) concentrations were measured in water sediment and organisms. The major differences in physical features between season were an increase of turbidity and salinity and depletion of dissolved oxygen in the rainy season. MP and 4-NP are bioconcentrated in organisms in response to environmental stress. MP concentration was measured in different size/age and reproductive stages separately. A significant concentration in reproductive tissues (plants)/unborn progeny (animals) was always found, and this can affect egg viability. The metabolite 4-NP is bioaccumulated and is toxic because it causes an increase of AChE activity. GGT activity was higher than that in controls. The increase in enzymatic activity provides a detoxification mechanism from chronic sublethal exposure, when hepatic glutation depletion occurs, and may be an indicator of liver damage.

  17. Improving the secretion of a methyl parathion hydrolase in Pichia pastoris by modifying its N-terminal sequence.

    PubMed

    Wang, Ping; Huang, Lu; Jiang, Hu; Tian, Jian; Chu, Xiaoyu; Wu, Ningfeng

    2014-01-01

    Pichia pastoris is commonly used to express and secrete target proteins, although not all recombinant proteins can be successfully produced. In this study, we used methyl parathion hydrolase (MPH) from Ochrobactrum sp. M231 as a model to study the importance of the N-terminus of the protein for its secretion. While MPH can be efficiently expressed intracellularly in P. pastoris, it is not secreted into the extracellular environment. Three MPH mutants (N66-MPH, D10-MPH, and N9-MPH) were constructed through modification of its N-terminus, and the secretion of each by P. pastoris was improved when compared to wild-type MPH. The level of secreted D10-MPH was increased to 0.21 U/mL, while that of N9-MPH was enhanced to 0.16 U/mL. Although N66-MPH was not enzymatically active, it was secreted efficiently, and was identified by SDS-PAGE. These results demonstrate that the secretion of heterologous proteins in P. pastoris may be improved by modifying their N-terminal structures.

  18. Photocatalytic degradation of commercial methyl parathion in aqueous suspension containing La-doped TiO2 nanoparticles.

    PubMed

    Chen, Hao; Shen, Min; Chen, Ruiwen; Dai, Ke; Peng, Tianyou

    2011-10-01

    The photocatalytic degradation of a commercial methyl parathion (MP) under UV irradiation was investigated in aqueous suspension containing lanthanum-doped mesoporous TiO2 nanoparticles (La/m-TiO2) as photocatalyst. The rate of photodecomposition of MP was measured using UV-Vis spectrophotometry, and its mineralization was followed using ion chromatography (IC). The identification of possible intermediate products was carried out using several powerful analytical techniques such as gas chromatography-pulsed flame photometric detector (GC-PFPD) and high performance liquid chromatography-mass spectroscopy (HPLC-MS). Under our conditions, complete disappearance of 20 mg/L of MP occurred within 2 h of illumination, whereas complete mineralization of MP was not achieved through IC analysis. There was a single intermediate product found in the research, which was identified to be methyl paraoxon, owing to the substitution of S by the O atom in the MP molecule. Based on the experimental facts, it is concluded that MP was mainly attacked not by OH radicals but photo-generated holes (h+), resulting from the good adsorption of MP on the catalyst surfaces due to the enhanced adsorption by La doping.

  19. Alteration of the kidney membrane proteome of Mizuhopecten yessoensis induced by low-level methyl parathion exposure.

    PubMed

    Huang, Xiang; Huang, He-Qing

    2012-06-15

    Methyl parathion (MP) is a widely used organophosphorus pesticide that causes severe health and environmental effects. We investigated the alteration of the proteomic profile in the membrane enriched fraction of the kidneys of the scallop Mizuhopecten yessoensis exposed to low-level MP. Gas chromatography analysis showed that MP residues were significantly accumulated in the kidneys and the digestive glands of the scallops. According to two-dimensional electrophoresis, 17 proteins were differentially modulated under MP exposure. The mRNA expressions of 12 differential proteins were analyzed using quantitative PCR, and 10 showed consistent alteration of mRNA level with that of protein expression level. Altered expressions of two proteins (mitochondrial processing peptidase and α-tubulin) were also examined using Western blotting, showing that the mitochondrial processing peptidase was down-regulated but α-tubulin remained unchanged in response to MP exposure. Subcellular locations of all the identified proteins that were predicted using bioinformatics tools indicate that few of them are permanently located in the membrane. The differentially expressed proteins are involved in several critical biological processes, and their relevance to human health has been illuminated. These data taken together have provided some novel insights into the chronic toxicity mechanism of MP and have suggested mitochondrial processing peptidase as a potential biomarker for human health and environmental monitoring.

  20. Methyl parathion imprinted polymer nanoshell coated on the magnetic nanocore for selective recognition and fast adsorption and separation in soils.

    PubMed

    Xu, Shiying; Guo, Changjuan; Li, Yongxian; Yu, Zerong; Wei, Chaohai; Tang, Youwen

    2014-01-15

    Core-shell magnetic methyl parathion (MP) imprinted polymers (Fe3O4@MPIPs) were fabricated by a layer-by-layer self-assembly process. In order to take full advantage of the synergistic effect of hydrogen-binding interactions and π-π accumulation between host and guest for molecular recognition, methacrylic acid and 4-vinyl pyridine were chosen as co-functional monomers and their optimal proportion were investigated. The core-shell and crystalline structure, morphology and magnetic properties of Fe3O4@MPIPs were characterized. The MP-imprinted nanoshell was almost uniform and about 100nm thick. Binding experiments demonstrated that Fe3O4@MPIPs possessed excellent binding properties, including high adsorption capacity and specific recognition, as well as fast adsorption kinetics and a fast phase separation rate. The equilibration adsorption capacity reached up to 9.1mg/g, which was 12 times higher than that of magnetic non-imprinted polymers, while adsorption reached equilibrium within 5min at a concentration of 0.2mmol/L. Furthermore, Fe3O4@MPIPs successfully provided selective separation and removal of MP in soils with a recovery and detection limit of 81.1-87.0% and 5.2ng/g, respectively.

  1. Oxidative Stress, Cytotoxicity, and Genotoxicity Induced by Methyl Parathion in Human Gingival Fibroblasts: Protective Role of Epigallocatechin-3-Gallate.

    PubMed

    Argentin, Gabriella; Divizia, Maurizio; Cicchetti, Rosadele

    2015-01-01

    Organophosphorous (OP) compounds are pesticides frequently released into the environment because of extensive use in agriculture. Among these, methyl parathion (mPT) recently received attention as a consequence of illegal use. The predominant route of human exposure to mPT is via inhalation, but inadvertent consumption of contaminated foods and water may also occur. The goal of this study was to investigate the in vitro effects of mPT on cells in the oral cavity and evaluate the potential protective role of epigallocathechin-3-gallate (EGCG) on these effects. Human gingival fibroblasts (HGF) were exposed to 10, 50, or 100 μ g/ml mPT for 24 h and assessed for oxidative stress, as evidenced by reactive generation of oxygen species (ROS), induction of apoptotic cell death, DNA damage (comet assay and cytochinesis-block micronucleus test), and nitric oxide (NO) production. The results showed that mPT produced significant oxidative stress, cytotoxicity, and genotoxicity and increased NO levels through stimulation of inducible NO synthase expression. Finally, data demonstrated that EGCG (10, 25, or 50 μ M) was able to inhibit the pesticide-induced effects on all parameters studied. Data indicate that cytotoxic and genotoxic effects may be associated with oxidative stress induced by mPT observed in HGF cultures and that EGCG plays a protective role via antioxidant activities.

  2. Biodegradation of methyl parathion and p-nitrophenol by a newly isolated Agrobacterium sp. strain Yw12.

    PubMed

    Wang, Shenghui; Zhang, Chen; Yan, Yanchun

    2012-02-01

    Strain Yw12, isolated from activated sludge, could completely degrade and utilize methyl parathion as the sole carbon, phosphorus and energy sources for growth in the basic salt media. It could also completely degrade and utilize p-nitrophenol as the sole carbon and energy sources for growth in the minimal salt media. Phenotypic features, physiological and biochemical characteristics, and phylogenetic analysis of 16S rRNA sequence showed that this strain belongs to the genus of Agrobacterium sp. Response surface methodology was used to optimize degradation conditions. Under its optimal degradation conditions, 50 mg l(-1) MP was completely degraded within 2 h by strain Yw12 and the degradation product PNP was also completely degraded within 6 h. Furthermore, strain Yw12 could also degrade phoxim, methamidophos, chlorpyrifos, carbofuran, deltamethrin and atrazine when provided as the sole carbon and energy sources. Enzymatic analysis revealed that the MP degrading enzyme of strain Yw12 is an intracellular enzyme and is expressed constitutively. These results indicated that strain Yw12 might be used as a potential and effective organophosphate pesticides degrader for bioremediation of contaminated sites.

  3. Burkholderia zhejiangensis sp. nov., a methyl-parathion-degrading bacterium isolated from a wastewater-treatment system.

    PubMed

    Lu, Peng; Zheng, Liu-Qiang; Sun, Jin-Jin; Liu, Hong-Ming; Li, Shun-Peng; Hong, Qing; Li, Wen-Jun

    2012-06-01

    The taxonomic status of a methyl-parathion-degrading strain, OP-1(T), isolated from a wastewater-treatment system in China, was determined using a polyphasic approach. The rod-shaped cells were Gram-staining-negative, non-spore-forming and non-motile. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel strain belonged to the genus Burkholderia, as it appeared closely related to Burkholderia glathei ATCC 29195(T) (97.4 % sequence similarity), Burkholderia sordidicola KCTC 12081(T) (96.5 %) and Burkholderia bryophila LMG 23644(T) (96.3 %). The major cellular fatty acids, C(16:0), C(17:0) cyclo and C(18:1)ω7c, were also similar to those found in established members of the genus Burkholderia. The genomic DNA G+C content of strain OP-1(T) was 59.4 mol%. The level of DNA-DNA relatedness between the novel strain and the closest recognized species, Burkholderia glathei ATCC 29195(T), was only 30 %. Based on the phenotypic, genotypic and phylogenetic evidence, strain OP-1(T) represents a novel species of the genus Burkholderia, for which the name Burkholderia zhejiangensis sp. nov. is proposed. The type strain is OP-1(T) ( = CCTCC AB 2010354(T) = KCTC 23300(T)).

  4. Biodegradation of methyl parathion by whole cells of marine-derived fungi Aspergillus sydowii and Penicillium decaturense.

    PubMed

    Alvarenga, Natália; Birolli, Willian G; Seleghim, Mirna H R; Porto, André L M

    2014-12-01

    Seven marine fungi strains (Aspergillus sydowii CBMAI 934, A. sydowii CBMAI 935, A. sydowii CBMAI 1241, Penicillium decaturense CBMAI 1234, Penicillium raistrickii CBMAI 931, P. raistrickii CBMAI 1235, and Trichoderma sp. CBMAI 932) were screened by their growth in the presence of methyl parathion (MP) in a solid culture medium. The strains with best growth were A. sydowii CBMAI 935 and P. decaturense CBMAI 1234. Biodegradation reactions were performed in 10, 20 and 30d in a malt extract liquid medium containing commercial MP and whole cells of A. sydowii CBMAI 935 and P. decaturense CBMAI 1234. In 20d, A. sydowii CBMAI 935 was able to degrade all pesticide, whereas P. decaturense CBMAI 1234 promoted a complete degradation in 30d. A. sydowii CBMAI 935 and P. decaturense CBMAI 1234 could degrade the product of the MP enzymatic hydrolysis, p-nitrophenol, on average of 51 and 40% respectively. Both strains used MP as a sole source of carbon and provided satisfactory results. Metabolites detected in the medium showed that the presumable reaction pathway occurred through the activation of MP to its more toxic form, methyl paraoxon, which was further degraded to p-nitrophenol.

  5. COMPPAP - COMPOSITE PLATE BUCKLING ANALYSIS PROGRAM (IBM PC VERSION)

    NASA Technical Reports Server (NTRS)

    Smith, J. P.

    1994-01-01

    The Composite Plate Buckling Analysis Program (COMPPAP) was written to help engineers determine buckling loads of orthotropic (or isotropic) irregularly shaped plates without requiring hand calculations from design curves or extensive finite element modeling. COMPPAP is a one element finite element program that utilizes high-order displacement functions. The high order of the displacement functions enables the user to produce results more accurate than traditional h-finite elements. This program uses these high-order displacement functions to perform a plane stress analysis of a general plate followed by a buckling calculation based on the stresses found in the plane stress solution. The current version assumes a flat plate (constant thickness) subject to a constant edge load (normal or shear) on one or more edges. COMPPAP uses the power method to find the eigenvalues of the buckling problem. The power method provides an efficient solution when only one eigenvalue is desired. Once the eigenvalue is found, the eigenvector, which corresponds to the plate buckling mode shape, results as a by-product. A positive feature of the power method is that the dominant eigenvalue is the first found, which is this case is the plate buckling load. The reported eigenvalue expresses a load factor to induce plate buckling. COMPPAP is written in ANSI FORTRAN 77. Two machine versions are available from COSMIC: a PC version (MSC-22428), which is for IBM PC 386 series and higher computers and compatibles running MS-DOS; and a UNIX version (MSC-22286). The distribution medium for both machine versions includes source code for both single and double precision versions of COMPPAP. The PC version includes source code which has been optimized for implementation within DOS memory constraints as well as sample executables for both the single and double precision versions of COMPPAP. The double precision versions of COMPPAP have been successfully implemented on an IBM PC 386 compatible running

  6. Wf/pc Cycle 1 Cal: Non-Sv PC Flats 1

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1990-12-01

    This program takes "uniform illuminated" pictures of the earth to obtain the "instrument signature" for flat field corrections. This proposal contains observations for all PC filters used by GOs and GTOs during Cycle 1 which were not included in the SV program. The camera - filter combinations done in this proposal are: PC: F368M,F588N,F631N,F648M,F875M,F1042M These are the PC flats which are not expected to saturate on the bright earth.

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

    NASA Technical Reports Server (NTRS)

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Speech coding

    SciTech Connect

    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

  10. The vital function of Fe3O4@Au nanocomposites for hydrolase biosensor design and its application in detection of methyl parathion

    NASA Astrophysics Data System (ADS)

    Zhao, Yuting; Zhang, Weiying; Lin, Yuehe; Du, Dan

    2013-01-01

    A nanocomposite of gold nanoparticles (AuNPs) decorating a magnetic Fe3O4 core was synthesized using cysteamine (SH-NH2) as linker, and characterized by TEM, XPS, UV and electrochemistry. Then a hydrolase biosensor, based on self-assembly of methyl parathion hydrolase (MPH) on the Fe3O4@Au nanocomposite, was developed for sensitive and selective detection of the organophosphorus pesticide (OP) methyl parathion. The magnetic nanocomposite provides an easy way to construct the enzyme biosensor by simply exerting an external magnetic field, and also provides a simple way to renew the electrode surface by removing the magnet. Unlike inhibition-based enzyme biosensors, the hydrolase is not poisoned by OPs and thus is reusable for continuous measurement. AuNPs not only provide a large surface area, high loading efficiency and fast electron transfer, but also stabilize the enzyme through electrostatic interactions. The MPH biosensor shows rapid response and high selectivity for detection of methyl parathion, with a linear range from 0.5 to 1000 ng mL-1 and a detection limit of 0.1 ng mL-1. It also shows acceptable reproducibility and stability. The simplicity and ease of operation of the proposed method has great potential for on-site detection of P-S containing pesticides and provides a promising strategy to construct a robust biosensor.A nanocomposite of gold nanoparticles (AuNPs) decorating a magnetic Fe3O4 core was synthesized using cysteamine (SH-NH2) as linker, and characterized by TEM, XPS, UV and electrochemistry. Then a hydrolase biosensor, based on self-assembly of methyl parathion hydrolase (MPH) on the Fe3O4@Au nanocomposite, was developed for sensitive and selective detection of the organophosphorus pesticide (OP) methyl parathion. The magnetic nanocomposite provides an easy way to construct the enzyme biosensor by simply exerting an external magnetic field, and also provides a simple way to renew the electrode surface by removing the magnet. Unlike

  11. PC1/3, PC2 and PC5/6A are targeted to dense core secretory granules by a common mechanism.

    PubMed

    Dikeakos, Jimmy D; Mercure, Chantal; Lacombe, Marie-Josée; Seidah, Nabil G; Reudelhuber, Timothy L

    2007-08-01

    There are seven members of the proprotein convertase (PC) family of secreted serine proteases that cleave their substrates at basic amino acids, thereby activating a variety of hormones, growth factors, and viruses. PC1/3, PC2 and PC5/6A are the only members of the PC family that are targeted to dense core secretory granules, where they carry out the processing of proteins that are secreted from the cell in a regulated manner. Previous studies have identified alpha-helices in the C-termini of the PC1/3 and PC2 proteases that are required for this subcellular targeting. In the current study, we demonstrate that a predicted alpha-helix in the C-terminus of PC5/6A is also critical for the ability of this domain to target a heterologous protein to the regulated secretory pathway of mouse endocrine AtT-20 cells. Analysis of the subcellular distribution of fusion proteins containing the C-terminal domains of PC1/3, PC2 and PC5/6A confirmed that all three domains have the capacity to redirect a constitutively secreted protein to the granule-containing cytoplasmic extensions. Analysis of the predicted structures formed by these three granule-sorting helices shows a correlation between their granule-sorting efficiency and the clustering of hydrophobic amino acids in their granule-targeting helices.

  12. Methyl parathion inhibits the nuclear maturation, decreases the cytoplasmic quality in oocytes and alters the developmental potential of embryos of Swiss albino mice

    SciTech Connect

    Nair, Ramya; Singh, Vikram Jeet; Salian, Sujith Raj; Kalthur, Sneha Guruprasad; D'Souza, Antony Sylvan; Shetty, Pallavi K.; Mutalik, Srinivas; Kalthur, Guruprasad; Adiga, Satish Kumar

    2014-09-15

    Methyl parathion (MP) is one of the most commonly used and extremely toxic organophosphorous group of pesticide. A large number of studies in the literature suggest that it has adverse effects on the male reproductive system. However, there is limited information about its toxicity to the female reproductive system. In the present study we report the toxic effects of methyl parathion on the female reproductive system using Swiss albino mice as the experimental model. The female mice were administered orally with 5, 10 and 20 mg/kg of MP. One week later, the mice were superovulated with pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG) to study the quality of the oocytes, spindle organization, developmental potential of early embryos and the DNA integrity in blastocysts. MP exposure resulted in a non-significant decrease in the number of primordial follicles and increased DNA damage in granulosa cells. Though MP did not have any effect on the ovulation it had a significant inhibitory effect on the nuclear maturity of oocytes which was associated with spindle deformity. In addition, the oocytes had higher cytoplasmic abnormalities with depleted glutathione level. Even though it did not have any effect on the fertilization and blastocyst rate at lower doses, at 20 mg/kg MP it resulted in a significant decrease in blastocyst hatching, decrease in cell number and high DNA damage. While low body weight gain was observed in F1 generation from 5 mg/kg group, at higher dose, the body weight in F1 generation was marginally higher than control. Post-natal death in F1 generation was observed only in mice treated with 20 mg/kg MP. In conclusion, we report that MP has adverse effects on the oocyte quality, developmental potential of the embryo and reproductive outcome. - Highlights: • Methyl parathion induces severe cytoplasmic abnormalities in oocytes. • Inhibits nuclear maturation and spindle damage • Poor blastocyst quality and high DNA

  13. PC12 differentiation on biopolymer nanostructures

    NASA Astrophysics Data System (ADS)

    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.

  14. IBM PC enhances the world's future

    NASA Technical Reports Server (NTRS)

    Cox, Jozelle

    1988-01-01

    Although the purpose of this research is to illustrate the importance of computers to the public, particularly the IBM PC, present examinations will include computers developed before the IBM PC was brought into use. IBM, as well as other computing facilities, began serving the public years ago, and is continuing to find ways to enhance the existence of man. With new developments in supercomputers like the Cray-2, and the recent advances in artificial intelligence programming, the human race is gaining knowledge at a rapid pace. All have benefited from the development of computers in the world; not only have they brought new assets to life, but have made life more and more of a challenge everyday.

  15. A PC based fault diagnosis expert system

    NASA Technical Reports Server (NTRS)

    Marsh, Christopher A.

    1990-01-01

    The Integrated Status Assessment (ISA) prototype expert system performs system level fault diagnosis using rules and models created by the user. The ISA evolved from concepts to a stand-alone demonstration prototype using OPS5 on a LISP Machine. The LISP based prototype was rewritten in C and the C Language Integrated Production System (CLIPS) to run on a Personal Computer (PC) and a graphics workstation. The ISA prototype has been used to demonstrate fault diagnosis functions of Space Station Freedom's Operation Management System (OMS). This paper describes the development of the ISA prototype from early concepts to the current PC/workstation version used today and describes future areas of development for the prototype.

  16. QR Codes

    ERIC Educational Resources Information Center

    Lai, Hsin-Chih; Chang, Chun-Yen; Li, Wen-Shiane; Fan, Yu-Lin; Wu, Ying-Tien

    2013-01-01

    This study presents an m-learning method that incorporates Integrated Quick Response (QR) codes. This learning method not only achieves the objectives of outdoor education, but it also increases applications of Cognitive Theory of Multimedia Learning (CTML) (Mayer, 2001) in m-learning for practical use in a diverse range of outdoor locations. When…

  17. Virtual Reality at the PC Level

    NASA Technical Reports Server (NTRS)

    Dean, John

    1998-01-01

    The main objective of my research has been to incorporate virtual reality at the desktop level; i.e., create virtual reality software that can be run fairly inexpensively on standard PC's. The standard language used for virtual reality on PC's is VRML (Virtual Reality Modeling Language). It is a new language so it is still undergoing a lot of changes. VRML 1.0 came out only a couple years ago and VRML 2.0 came out around last September. VRML is an interpreted language that is run by a web browser plug-in. It is fairly flexible in terms of allowing you to create different shapes and animations. Before this summer, I knew very little about virtual reality and I did not know VRML at all. I learned the VRML language by reading two books and experimenting on a PC. The following topics are presented: CAD to VRML, VRML 1.0 to VRML 2.0, VRML authoring tools, VRML browsers, finding virtual reality applications, the AXAF project, the VRML generator program, web communities and future plans.

  18. Chlorpyrifos-, Diisopropylphosphorofluoridate-, and Parathion-Induced Behavioral and Oxidative Stress Effects: Are They Mediated by Analogous Mechanisms of Action?

    PubMed Central

    Sánchez-Santed, Fernando

    2013-01-01

    Exposure to organophosphates (OPs) can lead to cognitive deficits and oxidative damage. Little is known about the relationship between behavioral deficits and oxidative stress within the context of such exposures. Accordingly, the first experiment was carried out to address this issue. Male Wistar rats were administered 250mg/kg of chlorpyrifos (CPF), 1.5mg/kg of diisopropylphosphorofluoridate (DFP), or 15mg/kg of parathion (PTN). Spatial learning in the water maze task was evaluated, and F2-isoprostanes (F2-IsoPs) and prostaglandin (PGE2) were analyzed in the hippocampus. A second experiment was designed to determine the degree of inhibition of brain acetylcholinesterase (AChE) activity, both the soluble and particulate forms of the enzyme, and to assess changes in AChE gene expression given evidence on alternative splicing of the gene in response to OP exposures. In addition, brain acylpeptide hydrolase (APH) activity was evaluated as a second target for OP-mediated effects. In both experiments, rats were sacrificed at various points to determine the time course of OPs toxicity in relation to their mechanism of action. Results from the first experiment suggest cognitive and emotional deficits after OPs exposure, which could be due to, at least in part, increased F2-IsoPs levels. Results from the second experiment revealed inhibition of brain AChE and APH activity at various time points post OP exposure. In addition, we observed increased brain read-through splice variant AChE (AChE-R) mRNA levels after 48h PTN exposure. In conclusion, this study provides novel data on the relationship between cognitive alterations and oxidative stress, and the diverse mechanisms of action along a temporal axis in response to OP exposures in the rat. PMID:22986948

  19. Differential protein profile in zebrafish (Danio rerio) brain under the joint exposure of methyl parathion and cadmium.

    PubMed

    Ling, Xue-Ping; Lu, Ying-Hua; Huang, He-Qing

    2012-11-01

    As different chemicals, methyl parathion (MP) and cadmium (Cd) can induce neurotoxicity on the brain of aquatic ecosystems. This study aims to explore the differential expression proteins in the brain induced by their joint stress and their joint effects, which are poorly reported, and devotes finding novel biomarkers for monitoring their contamination in water and assessing their neurological effects. The bioaccumulation of MP and Cd in tissues after 96 h of exposure was first analyzed by GC and inductively coupled plasma-MS to provide insights into the interaction. Protein profile changes in the brains of the zebrafish (Danio rerio) exposed to MP and Cd were further investigated using the proteomic approach. The correlation of gene expression on the transcription level of mRNA and the translation level of protein was examined by real-time quantitative PCR and Western blotting analysis. It showed that Cd and MP have an interaction on their bioaccumulation, which suggests that their joint effect over 96 h might be antagonistic. Proteomics revealed that 22 protein spots changed their expression levels under stress, of which 16 proteins were identified using MS. These proteins were involved in oxidation/reduction, metabolism, energy production, receptor activity, and cytoskeleton assembly. Among them, five proteins with a remarkable abundance change are significantly suggested to play important roles in the joint effect. This work demonstrates that there exists an interaction between MP and Cd toxicities, which may aid in our understanding of the mechanism of neurotoxicity induced by joint stress. The results may also provide the possibility of the establishment of candidate biomarkers for monitoring MP and Cd contamination in water.

  20. Enhanced electrochemiluminescence employed for the selective detection of methyl parathion based on a zirconia nanoparticle film modified electrode.

    PubMed

    Zhou, Hankun; Gan, Ning; Hou, Jianguo; Li, Tianhua; Cao, Yuting

    2012-01-01

    A simple, rapid and sensitive electrochemiluminescence (ECL) sensor was proposed for direct measurements of methyl parathion (MP) based on the strong affinity of a nano zirconia particles (ZrO(2) NPs) modified film on the electrode to the phosphoric group. ZrO(2) NPs, which could provide a larger absorption area to immobilize organophosphorus, was firstly modified on the glassy carbon electrode surface to prepare the proposed ECL sensor (ZrO(2)/GC). Subsequently, the ZrO(2)/GC electrode was scanned from -0.8 to +0.6 V to obtain the background signal at 0.44 V in a luminol/KCl solution. Then, a certain concentration of MP was added to an aqueous solution for 240 s, which was absorbed onto the ZrO(2)/GC electrode surface. Moreover, the MP absorbed on the surface of the ZrO(2)/GC electrode enhanced the ECL signal of luminol in the luminol/KCl solution, which increased with the concentration of MP. As a result, a novel ECL sensor was obtained in a luminol/KCl solution. The MP was determined in the range of from 3.8 × 10(-11) to 3.8 × 10(-6) mol L(-1), with a low detection limit of 1.27 × 10(-11) mol L(-1) (S/N = 3). The proposed ECL sensor performance for MP detection will open a new field in the application of rapid and screen detection of ultra-trace amounts of organ phosphorus pesticides (OPs) of vegetables used in farm markets.

  1. Enhanced thermostability of methyl parathion hydrolase from Ochrobactrum sp. M231 by rational engineering of a glycine to proline mutation.

    PubMed

    Tian, Jian; Wang, Ping; Gao, Shan; Chu, Xiaoyu; Wu, Ningfeng; Fan, Yunliu

    2010-12-01

    Protein thermostability can be increased by some glycine to proline mutations in a target protein. However, not all glycine to proline mutations can improve protein thermostability, and this method is suitable only at carefully selected mutation sites that can accommodate structural stabilization. In this study, homology modeling and molecular dynamics simulations were used to select appropriate glycine to proline mutations to improve protein thermostability, and the effect of the selected mutations was proved by the experiments. The structure of methyl parathion hydrolase (MPH) from Ochrobactrum sp. M231 (Ochr-MPH) was constructed by homology modeling, and molecular dynamics simulations were performed on the modeled structure. A profile of the root mean square fluctuations of Ochr-MPH was calculated at the nanosecond timescale, and an eight-amino acid loop region (residues 186-193) was identified as having high conformational fluctuation. The two glycines nearest to this region were selected as mutation targets that might affect protein flexibility in the vicinity. The structures and conformational fluctuations of two single mutants (G194P and G198P) and one double mutant (G194P/G198P) were modeled and analyzed using molecular dynamics simulations. The results predicted that the mutant G194P had the decreased conformational fluctuation in the loop region and might increase the thermostability of Ochr-MPH. The thermostability and kinetic behavior of the wild-type and three mutant enzymes were measured. The results were consistent with the computational predictions, and the mutant G194P was found to have higher thermostability than the wild-type enzyme.

  2. 39 CFR 501.16 - PC postage payment methodology.

    Code of Federal Regulations, 2010 CFR

    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...

  3. The USL NASA PC R and D development environment standards

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Moreau, Dennis R.

    1984-01-01

    The development environment standards which have been established in order to control usage of the IBM PC/XT development systems and to prevent interference between projects being currently developed on the PC's are discussed. The standards address the following areas: scheduling PC resources; login/logout procedures; training; file naming conventions; hard disk organization; diskette care; backup procedures; and copying policies.

  4. Wf/pc Cycle 1 Calib: Non-Sv PC Flats 2

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1990-12-01

    This program takes "uniform illuminated" pictures of the earth to obtain the "instrument signature" for flat field corrections. This proposal series contains observations for all PC filters used by GOs and GTOs during Cycle 1 which were not included in the SV program. The camera - filter combinations done in this proposal are: PC: F569W, F606W, F675W, F725LP, F791W, F814W, F850LP (these are done in combination with F122M) These are the PC flats which are expected to saturate on the bright earth without a neutral density filter. The following observations are also included to permit correction for the F122M filter: F517N+F122M, F517N, F664N+F122M, F664N, F718M+F122M, F718M, F875M+F122M, F875M

  5. Development of a novel optical biosensor for detection of organophosphorus pesticides based on methyl parathion hydrolase immobilized by metal-chelate affinity.

    PubMed

    Lan, Wensheng; Chen, Guoping; Cui, Feng; Tan, Feng; Liu, Ran; Yushupujiang, Maolidan

    2012-01-01

    We have developed a novel optical biosensor device using recombinant methyl parathion hydrolase (MPH) enzyme immobilized on agarose by metal-chelate affinity to detect organophosphorus (OP) compounds with a nitrophenyl group. The biosensor principle is based on the optical measurement of the product of OP catalysis by MPH (p-nitrophenol). Briefly, MPH containing six sequential histidines (6 × His tag) at its N-terminal was bound to nitrilotriacetic acid (NTA) agarose with Ni ions, resulting in the flexible immobilization of the bio-reaction platform. The optical biosensing system consisted of two light-emitting diodes (LEDs) and one photodiode. The LED that emitted light at the wavelength of the maximum absorption for p-nitrophenol served as the signal light, while the other LED that showed no absorbance served as the reference light. The optical sensing system detected absorbance that was linearly correlated to methyl parathion (MP) concentration and the detection limit was estimated to be 4 μM. Sensor hysteresis was investigated and the results showed that at lower concentration range of MP the difference got from the opposite process curves was very small. With its easy immobilization of enzymes and simple design in structure, the system has the potential for development into a practical portable detector for field applications.

  6. IBM PC/IX operating system evaluation plan

    NASA Technical Reports Server (NTRS)

    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.

  7. Twostep-by-twostep PIRK-type PC methods with continuous output formulas

    NASA Astrophysics Data System (ADS)

    Cong, Nguyen Huu; Xuan, Le Ngoc

    2008-11-01

    This paper deals with parallel predictor-corrector (PC) iteration methods based on collocation Runge-Kutta (RK) corrector methods with continuous output formulas for solving nonstiff initial-value problems (IVPs) for systems of first-order differential equations. At nth step, the continuous output formulas are used not only for predicting the stage values in the PC iteration methods but also for calculating the step values at (n+2)th step. In this case, the integration processes can be proceeded twostep-by-twostep. The resulting twostep-by-twostep (TBT) parallel-iterated RK-type (PIRK-type) methods with continuous output formulas (twostep-by-twostep PIRKC methods or TBTPIRKC methods) give us a faster integration process. Fixed stepsize applications of these TBTPIRKC methods to a few widely-used test problems reveal that the new PC methods are much more efficient when compared with the well-known parallel-iterated RK methods (PIRK methods), parallel-iterated RK-type PC methods with continuous output formulas (PIRKC methods) and sequential explicit RK codes DOPRI5 and DOP853 available from the literature.

  8. The Local Population of White Dwarfs within 25 pc

    NASA Astrophysics Data System (ADS)

    Holberg, Jay B.; Oswalt, Terry D.; Sion, Edward M.

    2015-01-01

    We have extended the detailed survey of the local white dwarf population from 20 pc to 25 pc, effectively doubling the sample volume to now include 231 stars. The present 25 pc has an estimated completeness of 70% (the corresponding 20 pc sample is now 85% complete). The space density of white dwarfs remains at 4.8 ± 0.5 x 10-3 pc-3. There exists a curious excess of single stars in the sample 70% vs 30% in systems with one or more companions. A pronounced apparent deficiency remains between the eleven known Sirius-like systems present in the 20 pc sample and only a single such system presently known in the extended 25 pc sample. Also demonstrated, using explicit individual white dwarf cooling ages, is the feasibility of estimating the white dwarf birth rates over the last ~ 5 Gyr.This work is supported by NSF grant AST-1413537

  9. PC-based Multiple Information System Interface (PC/MISI) detailed design and implementation plan

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Hall, Philip P.

    1985-01-01

    The design plan for the personal computer multiple information system interface (PC/MISI) project is discussed. The document is intended to be used as a blueprint for the implementation of the system. Each component is described in the detail necessary to allow programmers to implement the system. A description of the system data flow and system file structures is given.

  10. THE ORIGIN OF OB CLUSTERS: FROM 10 pc TO 0.1 pc

    SciTech Connect

    Liu Hauyu Baobab; Wang Ke; Ho, Paul T. P.; Zhang Qizhou; Quintana-Lacaci, Guillermo; Li Zhiyun; Zhang Zhiyu E-mail: kwang@cfa.harvard.edu E-mail: quintana@iram.es E-mail: zl4h@virginia.edu

    2012-01-20

    We observe the 1.2 mm continuum emission around the OB cluster-forming region G10.6-0.4, using the MAMBO-2 bolometer array of the IRAM 30 m telescope and the Submillimeter Array (SMA). Comparison of the Spitzer 24 {mu}m and 8 {mu}m images with our 1.2 mm continuum maps reveal an ionization front of an H II region, the photon-dominated layer, and several 5 pc scale filaments that follow the outer edge of the photon-dominated layer. The filaments, which are resolved in the MAMBO-2 observations, show regularly spaced parsec-scale molecular clumps, embedded with a cluster of dense molecular cores as shown in the SMA 0.87 mm observations. Toward the center of the G10.6-0.4 region, the combined SMA+IRAM 30 m continuum image reveals several parsec-scale protrusions. They may continue down to within 0.1 pc of the geometric center of a dense 3 pc scale structure, where a 200 M{sub Sun} OB cluster resides. The observed filaments may facilitate mass accretion onto the central cluster-forming region in the presence of strong radiative and mechanical stellar feedback. Their filamentary geometry may also facilitate fragmentation. We did not detect any significant polarized emission at 0.87 mm in the inner 1 pc region with SMA.

  11. Remote estimation of phycocyanin (PC) for inland waters coupled with YSI PC fluorescence probe.

    PubMed

    Song, Kaishan; Li, Lin; Tedesco, Lenore; Clercin, Nicole; Hall, Bob; Li, Shuai; Shi, Kun; Liu, Dawei; Sun, Ying

    2013-08-01

    Nuisance cyanobacterial blooms degrade water resources through accelerated eutrophication, odor generation, and production of toxins that cause adverse effects on human health. Quick and effective methods for detecting cyanobacterial abundance in drinking water supplies are urgently needed to compliment conventional laboratory methods, which are costly and time consuming. Hyperspectral remote sensing can be an effective approach for rapid assessment of cyanobacterial blooms. Samples (n=250) were collected from five drinking water sources in central Indiana (CIN), USA, and South Australia (SA), which experience nuisance cyanobacterial blooms. In situ hyperspectral data were used to develop models by relating spectral signal with handheld fluorescence probe (YSI 6600 XLM-SV) measured phycocyanin (PC in cell/ml), a proxy pigment unique for indicating the presence of cyanobacteria. Three-band model (TBM), which is effective for chlorophyll-a estimates, was tuned to quantify cyanobacteria coupled with the PC probe measured cyanobacteria. As a comparison, two band model proposed by Simis et al. (Limnol Oceanogr, 50(11): 237-245, 2005; denoted as SM05) was paralleled to evaluate TBM model performance. Our observation revealed a high correlation between measured and estimated PC for SA dataset (R (2) =0.96; range: 534-20,200 cell/ml) and CIN dataset (R (2) =0.88; range: 1,300-44,500 cell/ml). The potential of this modeling approach for imagery data were assessed by simulated ESA/Centinel3/OLCI spectra, which also resulted in satisfactory performance with the TBM for both SA dataset (RMSE % =26.12) and CIN dataset (RMSE % =34.49). Close relationship between probe-measured PC and laboratory measured cyanobacteria biovolume was observed (R (2) =0.93, p<0.0001) for the CIN dataset, indicating a stable performance for PC probe. Based on our observation, field spectroscopic measurement coupled with PC probe measurements can provide quantitative cyanobacterial bloom

  12. (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8]/CuPc two-component bilayer heterojunction-based organic transistors with high ambipolar performance.

    PubMed

    Gao, Dameng; Zhang, Xia; Kong, Xia; Chen, Yanli; Jiang, Jianzhuang

    2015-02-04

    Organic thin film transistor (OTFT) devices fabricated by the solution-based QLS technique from a mixed (phthalocyaninato)(porphyrinato) europium complex (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8] exhibit air-stable ambipolar performance with mobilities of 6.0 × 10(-5) cm(2) V(-1) s(-)1 for holes and 1.4 × 10(-4) cm(2) V(-1) s(-1) for electrons, respectively. In good contrast, the two-component bilayer heterojunction thin film devices constructed by directly growing (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8] on vacuum deposited (VCD) CuPc film using solution based QLS method were revealed to show unprecedented ambipolar performance with carrier mobilities of 0.16 cm(2) V(-1) s(-1) for holes and 0.30 cm(2) V(-1) s(-1) for electrons. In addition to the intrinsic role of p-type organic semiconductor, the VCD CuPc film on the substrate also acts as a good template that induces significant improvement over the molecular ordering of triple-decker compound in the film. In particular, it results in the change in the aggregation mode of (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8] from J-type in the single-layer film to H-type in the bilayer film according to the UV-vis, XRD, and AFM observations.

  13. [Report on the VDÄPC Fellowship].

    PubMed

    Sarantopoulos, E

    2016-04-01

    "Orandum est ut sit mens sana in corpore sano" ("You should pray for a healthy mind in a healthy body"). This phrase is a shortened citation from the satirical work of the Roman poet Juvenal. It highlights the significant role of physical as well as mental health. Aesthetic ideals have existed since the Archaic age, but they are not necessarily the same in different continents. Being familiar with aesthetic ideals in different cultures might help to accommodate patients' needs and wishes in today's globalised world. Therefore, fellowship programs such as the program organised by the Association of German Aesthetic Plastic Surgeons ("VDÄPC") are very important for young plastic surgeons who are interested in improving their surgical skills and experience. After all, aesthetic surgery is a dynamic specialty, which requires aesthetic plastic surgeons to undergo continued medical education.

  14. Parallelized tree-code for clusters of personal computers

    NASA Astrophysics Data System (ADS)

    Viturro, H. R.; Carpintero, D. D.

    2000-02-01

    We present a tree-code for integrating the equations of the motion of collisionless systems, which has been fully parallelized and adapted to run in several PC-based processors simultaneously, using the well-known PVM message passing library software. SPH algorithms, not yet included, may be easily incorporated to the code. The code is written in ANSI C; it can be freely downloaded from a public ftp site. Simulations of collisions of galaxies are presented, with which the performance of the code is tested.

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

    SciTech Connect

    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.

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

    PubMed

    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.

  17. Error-correction coding

    NASA Technical Reports Server (NTRS)

    Hinds, Erold W. (Principal Investigator)

    1996-01-01

    This report describes the progress made towards the completion of a specific task on error-correcting coding. The proposed research consisted of investigating the use of modulation block codes as the inner code of a concatenated coding system in order to improve the overall space link communications performance. The study proposed to identify and analyze candidate codes that will complement the performance of the overall coding system which uses the interleaved RS (255,223) code as the outer code.

  18. Microcomputer Applications with PC LAN (Local Area Network) in Battleships.

    DTIC Science & Technology

    1988-12-01

    9 G. INTEL 80386 MICROPROCESSOR ARCHITECTURE 9 1. Cache Strategy 10 2. Memory Management 10 3. Multitasking 11 4. Software...shrinks, it becomes more clear that the traditional modes of battle planning and management are no longer practical. Many of these problems, like...Card in it. Each PC must run the PC Network program to manage its participation in the network. Each PC must have a cable to connect it to the

  19. Estimating Patient Condition Codes Using Data Mining Techniques

    DTIC Science & Technology

    2007-06-01

    Tissue Genitourinary Surgical Head Thorax Infectious/ Parasitic Upper Limbs Lower Limbs Dermatological Dental Nuclear, Biological, Chemical Patient Condition Categories ...rudimentary expert system with some medical knowledge rules. For instance, if blood was used, the injury was probably life threatening. • Expand to more...complex coding systems , like ICD-9 and ICD-10. This could be used for medical coding or for building a PC to ICD mapping. 15 Conclusion – Contact

  20. A finite element code for electric motor design

    NASA Technical Reports Server (NTRS)

    Campbell, C. Warren

    1994-01-01

    FEMOT is a finite element program for solving the nonlinear magnetostatic problem. This version uses nonlinear, Newton first order elements. The code can be used for electric motor design and analysis. FEMOT can be embedded within an optimization code that will vary nodal coordinates to optimize the motor design. The output from FEMOT can be used to determine motor back EMF, torque, cogging, and magnet saturation. It will run on a PC and will be available to anyone who wants to use it.

  1. Dynamic Forces in Spur Gears - Measurement, Prediction, and Code Validation

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.; Townsend, Dennis P.; Rebbechi, Brian; Lin, Hsiang Hsi

    1996-01-01

    Measured and computed values for dynamic loads in spur gears were compared to validate a new version of the NASA gear dynamics code DANST-PC. Strain gage data from six gear sets with different tooth profiles were processed to determine the dynamic forces acting between the gear teeth. Results demonstrate that the analysis code successfully simulates the dynamic behavior of the gears. Differences between analysis and experiment were less than 10 percent under most conditions.

  2. Electronic properties of CuPc and H2Pc: an experimental and theoretical study.

    PubMed

    Nardi, Marco Vittorio; Detto, Francesca; Aversa, Lucrezia; Verucchi, Roberto; Salviati, Giancarlo; Iannotta, Salvatore; Casarin, Maurizio

    2013-08-21

    Phthalocyanine (H2Pc) and its open-shell copper complex (CuPc) deposited on amorphous gold films have been studied by combining the outcomes of several synchrotron based spectroscopic tools (X-ray photoelectron spectroscopy, UV photoelectron spectroscopy and near-edge X-ray absorption fine structure, NEXAFS, spectroscopy) with those of density functional theory (DFT) calculations. The assignment of experimental evidence has been guided by the results of DFT numerical experiments carried out on isolated molecules. With specific reference to CuPc NEXAFS data collected at the N K-edge, they have been assigned by using the open-shell time-dependent DFT (TDDFT) in the framework of the zeroth order regular approximation (ZORA) scalar relativistic approach. The agreement between theory and experiment has been found to be satisfactory, thus indicating that the open-shell TDDFT (F. Wang and T. Ziegler, Mol. Phys., 2004, 102, 2585) may be used with some confidence to look into the X-ray absorption spectroscopy results pertinent to transition metal complexes. As far as the metal-ligand interaction is concerned, the combined use of NEXAFS spectroscopy and DFT outcomes ultimately testified the significant ionic contribution characterizing the bonding between the metal centre and the nitrogen atoms of the phthalocyanine coordinative pocket.

  3. Methyl parathion inhibits the nuclear maturation, decreases the cytoplasmic quality in oocytes and alters the developmental potential of embryos of Swiss albino mice.

    PubMed

    Nair, Ramya; Singh, Vikram Jeet; Salian, Sujith Raj; Kalthur, Sneha Guruprasad; D'Souza, Antony Sylvan; Shetty, Pallavi K; Mutalik, Srinivas; Kalthur, Guruprasad; Adiga, Satish Kumar

    2014-09-15

    Methyl parathion (MP) is one of the most commonly used and extremely toxic organophosphorous group of pesticide. A large number of studies in the literature suggest that it has adverse effects on the male reproductive system. However, there is limited information about its toxicity to the female reproductive system. In the present study we report the toxic effects of methyl parathion on the female reproductive system using Swiss albino mice as the experimental model. The female mice were administered orally with 5, 10 and 20mg/kg of MP. One week later, the mice were superovulated with pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG) to study the quality of the oocytes, spindle organization, developmental potential of early embryos and the DNA integrity in blastocysts. MP exposure resulted in a non-significant decrease in the number of primordial follicles and increased DNA damage in granulosa cells. Though MP did not have any effect on the ovulation it had a significant inhibitory effect on the nuclear maturity of oocytes which was associated with spindle deformity. In addition, the oocytes had higher cytoplasmic abnormalities with depleted glutathione level. Even though it did not have any effect on the fertilization and blastocyst rate at lower doses, at 20 mg/kg MP it resulted in a significant decrease in blastocyst hatching, decrease in cell number and high DNA damage. While low body weight gain was observed in F1 generation from 5mg/kg group, at higher dose, the body weight in F1 generation was marginally higher than control. Post-natal death in F1 generation was observed only in mice treated with 20mg/kg MP. In conclusion, we report that MP has adverse effects on the oocyte quality, developmental potential of the embryo and reproductive outcome.

  4. Inhibition of Prohormone Convertases PC1/3 and PC2 by 2,5-Dideoxystreptamine Derivatives

    PubMed Central

    Vivoli, Mirella; Caulfield, Thomas R.; Martínez-Mayorga, Karina; Johnson, Alan T.; Jiao, Guan-Sheng

    2012-01-01

    The prohormone convertases PC1/3 and PC2 are eukaryotic serine proteases involved in the proteolytic maturation of peptide hormone precursors and are implicated in a variety of pathological conditions, including obesity, diabetes, and neurodegenerative diseases. In this work, we screened 45 compounds obtained by derivatization of a 2,5-dideoxystreptamine scaffold with guanidinyl and aryl substitutions for convertase inhibition. We identified four promising PC1/3 competitive inhibitors and three PC2 inhibitors that exhibited various inhibition mechanisms (competitive, noncompetitive, and mixed), with sub- and low micromolar inhibitory potency against a fluorogenic substrate. Low micromolar concentrations of certain compounds blocked the processing of the physiological substrate proglucagon. The best PC2 inhibitor effectively inhibited glucagon synthesis, a known PC2-mediated process, in a pancreatic cell line; no cytotoxicity was observed. We also identified compounds that were able to stimulate both 87 kDa PC1/3 and PC2 activity, behavior related to the presence of aryl groups on the dideoxystreptamine scaffold. By contrast, inhibitory activity was associated with the presence of guanidinyl groups. Molecular modeling revealed interactions of the PC1/3 inhibitors with the active site that suggest structural modifications to further enhance potency. In support of kinetic data suggesting that PC2 inhibition probably occurs via an allosteric mechanism, we identified several possible allosteric binding sites using computational searches. It is noteworthy that one compound was found to both inhibit PC2 and stimulate PC1/3. Because glucagon acts in functional opposition to insulin in blood glucose homeostasis, blocking glucagon formation and enhancing proinsulin cleavage with a single compound could represent an attractive therapeutic approach in diabetes. PMID:22169851

  5. Quantification of PrPC in bovine peripheral tissues: Analysis in wild-type and PrPC-deficient cattle.

    PubMed

    Kobayashi, Shin-Ichi; Ano, Yasuhisa; Sakudo, Akikazu; Yukawa, Masayoshi; Sigiura, Katsuaki; Manabe, Noboru; Nakayama, Hiroyuki; Onodera, Takashi

    2009-01-01

    Cellular PrP (PrPC) is necessary for bovine spongiform encephalopathy (BSE) infection. The purpose of the present experiment was the quantification of PrPC in peripheral tissues to assess the risk of BSE infection from these tissues. The tissue distribution of PrPC was examined by a sandwich enzyme-linked immunosorbent assay (sELISA) and histochemical analysis. PrPC-deficient cows were used as a negative control. The sELISA revealed that the brain contained the highest PrPC content (10.7 µg/g tissue), while other organs/tissues harbored lower amounts, in decreasing order as follows: longissimus capitis muscle, iliocostalis thoracis muscle, splenius muscle, biceps femoris muscle, triceps brachii muscle, longissimus thoracis muscle, ileum, jejunum, duodenum, colon, cecum, apex linguae, omotransversarius muscle, posterior part of the corpus linguae, anterior part of the corpus linguae and radix linguae (5.2- to 31-fold less PrPC than the brain). In the tissue/organs of PrP-deficient cows, PrPC levels were under the limit of detection. Histochemical analysis showed that PrPC was expressed in nerve cells in intestinal tissues. The presence of PrPC in the bovine tongue, skeletal muscles and intestines raises the possibility of PrPSc accumulation in these tissues, indicating that these organs/tissues may serve as potential sources of BSE infection.

  6. Physical Properties of PC-PMMA Multilayers

    NASA Astrophysics Data System (ADS)

    Rahman, Arifur; Baer, Eric; Chipara, Alin Cristian; Vajtai, Robert; Ajayan, Pullickel M.; Hinthorne, James; Elamin, Ibrahim; Chipara, Mircea; Eric Baer Collaboration; Pullickel Ajayan Collaboration; Mircea Chipara Collaboration

    2015-03-01

    Multilayers of polycarbonate (PC) and polymethylmethacrylate (PMMA) have been obtained by the layer multiplying coextrusion method. Each sample (1024 layers, of equal thickness, with individual thickness between 10 and 200 nm) has been investigated at room temperature by Wide Angle X-Ray Scattering (WAXS) using a Bruker Discovery 8 spectrometer (Cu K α radiation), Raman spectroscopy (Bruker Senterra confocal Raman spectrometer operating at 785 nm), FTIR spectroscopy (Tensor 27 Bruker), and UV-Vis spectroscopy. Further details about the glass transition temperature in these samples have been obtained by Dynamical Mechanical Analysis, DMA, (TA Instruments Q800) at various frequencies in the range 1 to 100 Hz. Isothermal Differential Scanning Calorimetry, DSC, (TA Instruments Q200) was used to investigate the effect of the thickness of the polymeric film on the crystallization processes. Non-isothermal DSC measurements aimed at the identification and location of the main phase transitions (glass, crystallization, and melting) occurring in these multilayers. The effects of confinement on the phase transitions occurring in these multilayers are discussed in detail.

  7. Pc-Based Floating Point Imaging Workstation

    NASA Astrophysics Data System (ADS)

    Guzak, Chris J.; Pier, Richard M.; Chinn, Patty; Kim, Yongmin

    1989-07-01

    The medical, military, scientific and industrial communities have come to rely on imaging and computer graphics for solutions to many types of problems. Systems based on imaging technology are used to acquire and process images, and analyze and extract data from images that would otherwise be of little use. Images can be transformed and enhanced to reveal detail and meaning that would go undetected without imaging techniques. The success of imaging has increased the demand for faster and less expensive imaging systems and as these systems become available, more and more applications are discovered and more demands are made. From the designer's perspective the challenge to meet these demands forces him to attack the problem of imaging from a different perspective. The computing demands of imaging algorithms must be balanced against the desire for affordability and flexibility. Systems must be flexible and easy to use, ready for current applications but at the same time anticipating new, unthought of uses. Here at the University of Washington Image Processing Systems Lab (IPSL) we are focusing our attention on imaging and graphics systems that implement imaging algorithms for use in an interactive environment. We have developed a PC-based imaging workstation with the goal to provide powerful and flexible, floating point processing capabilities, along with graphics functions in an affordable package suitable for diverse environments and many applications.

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

    DTIC Science & Technology

    1984-09-01

    approximately 󈧨,000 [Ref. 2: p . 151. The cost of each of the systems used in this research is about the same, but there is 8 hardly a comparison in...lurin;~ NCuQM ThrrrY ie many’ -the 1 - IM nt s p s udo -dync ir c’ ’ma ryZ -n A, t i r l 1 ma Pq ita a UK X Cw ir 4. The solution of eigen value...architecture and instruction sets. Rao [Ref. 1: p . 2051 cites a ten fold improvement in execu- tion time for the Intel 8086 over the Intel 8080A while the

  9. Attention selection, distractor suppression and N2pc.

    PubMed

    Mazza, Veronica; Turatto, Massimo; Caramazza, Alfonso

    2009-01-01

    N2pc is generally interpreted as the electrocortical correlate of the distractor-suppression mechanisms through which attention selection takes place in humans. Here, we present data that challenge this common N2pc interpretation. In Experiment 1, multiple distractors induced greater N2pc amplitudes even when they facilitated target identification, despite the suppression account of the N2pc predicted the contrary; in Experiment 2, spatial proximity between target and distractors did not affect the N2pc amplitude, despite resulting in more interference in response times; in Experiment 3, heterogeneous distractors delayed response times but did not elicit a greater N2pc relative to homogeneous distractors again in contrast with what would have predicted the suppression hypothesis. These results do not support the notion that the N2pc unequivocally mirrors distractor-suppression processes. We propose that the N2pc indexes mechanisms involved in identifying and localizing relevant stimuli in the scene through enhancement of their features and not suppression of distractors.

  10. PC2 Ovotransferrin: Characterization and Alternative Immunotherapeutic Activity

    PubMed Central

    Chiurciu, Constantin; Chiurciu, Viorica; Oporanu, Mariana; Pătrașcu, Ionel Victor; Mihai, Iuliana; Tablică, Mădălina

    2017-01-01

    Characterization and evaluation of immunotherapeutic potential of ovotransferrin PC2 (OTf PC2) were performed in this study. The ovoprotein was obtained from egg white from hens immunized with bacterial antigens, pathogenic for humans. For the negative control samples, OTf was extracted from eggs collected from Specific Pathogen-Free (SPF) hens and purified by affinity chromatography on Protein G-agarose column with two eluting peaks: I, representing ovalbumin, and II, ovotransferrin. The final apo-OTf form was reached by successive precipitation with ammonium sulfate and citric acid and the holo-OTf form by saturating the apo-form with FeCl3. Multiple OTf PC2 samples were analyzed through Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) and, based on the molecular marker migration model, the ovotransferrin (76.5 kDa) and ovalbumin (45 kDa) were detected. The agglutination reaction exhibited statistically significant high specificity of the multiple OTf PC2, by reacting with the antigens used for hens' immunization. Following ELISA, it was established that OTf PC2 from hyperimmune eggs has specificity for all antigens; the antibody titer was high, indicating that OTf PC2 possesses immunological properties similar to immunoglobulin Y (Ig Y). This study suggests that OTf PC2 immunological activity may play a crucial role in the prevention and treatment of infections resistant to antibiotics and OTf PC2 can also act as a valuable nutraceutical.

  11. Chromosomal Distribution of PcG Proteins during Drosophila Development

    PubMed Central

    Nègre, Nicolas; Hennetin, Jérôme; Sun, Ling V; Lavrov, Sergey; Bellis, Michel; White, Kevin P

    2006-01-01

    Polycomb group (PcG) proteins are able to maintain the memory of silent transcriptional states of homeotic genes throughout development. In Drosophila, they form multimeric complexes that bind to specific DNA regulatory elements named PcG response elements (PREs). To date, few PREs have been identified and the chromosomal distribution of PcG proteins during development is unknown. We used chromatin immunoprecipitation (ChIP) with genomic tiling path microarrays to analyze the binding profile of the PcG proteins Polycomb (PC) and Polyhomeotic (PH) across 10 Mb of euchromatin. We also analyzed the distribution of GAGA factor (GAF), a sequence-specific DNA binding protein that is found at most previously identified PREs. Our data show that PC and PH often bind to clustered regions within large loci that encode transcription factors which play multiple roles in developmental patterning and in the regulation of cell proliferation. GAF co-localizes with PC and PH to a limited extent, suggesting that GAF is not a necessary component of chromatin at PREs. Finally, the chromosome-association profile of PC and PH changes during development, suggesting that the function of these proteins in the regulation of some of their target genes might be more dynamic than previously anticipated. PMID:16613483

  12. Hydrogen bonds in PC{sub 61}BM solids

    SciTech Connect

    Sheng, Chun-Qi; Li, Wen-Jie; Du, Ying-Ying; Chen, Guang-Hua; Chen, Zheng; Li, Hai-Yang; Li, Hong-Nian

    2015-09-15

    We have studied the hydrogen bonds in PC{sub 61}BM solids. Inter-molecular interaction is analyzed theoretically for the well-defined monoclinic (P2{sub 1}/n) structure. The results indicate that PC{sub 61}BM combines into C–H⋯O{sub d} bonded molecular chains, where O{sub d} denotes the doubly-bonded O atom of PC{sub 61}BM. The molecular chains are linked together by C–H⋯O{sub s} bonds, where O{sub s} denotes the singly-bonded O atom of PC{sub 61}BM. To reveal the consequences of hydrogen bond formation on the structural properties of PC{sub 61}BM solids (not limited to the monoclinic structure), we design and perform some experiments for annealed samples with the monoclinic (P2{sub 1}/n) PC{sub 61}BM as starting material. The experiments include differential scanning calorimetry, X-ray diffraction and infrared absorption measurements. Structural phase transitions are observed below the melting point. The C–H⋯O{sub d} bonds seem persisting in the altered structures. The inter-molecular hydrogen bonds can help to understand the phase separation in polymer/PC{sub 61}BM blends and may be responsible for the existence of liquid PC{sub 61}BM.

  13. PrPC from stem cells to cancer

    PubMed Central

    Martin-Lannerée, Séverine; Hirsch, Théo Z.; Hernandez-Rapp, Julia; Halliez, Sophie; Vilotte, Jean-Luc; Launay, Jean-Marie; Mouillet-Richard, Sophie

    2014-01-01

    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 knockout 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 tumors. 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 tumor-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. PMID:25364760

  14. Transforming PC Power Supplies into Smart Car Battery Conditioners

    ERIC Educational Resources Information Center

    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…

  15. PC/FRAM, Version 3.2 User Manual

    SciTech Connect

    Kelley, T.A.; Sampson, T.E.

    1999-02-23

    This manual describes the use of version 3.2 of the PC/FRAM plutonium isotopic analysis software developed in the Safeguards Science and Technology Group, NE-5, Nonproliferation and International Security Division Los Alamos National Laboratory. The software analyzes the gamma ray spectrum from plutonium-bearing items and determines the isotopic distribution of the plutonium 241Am content and concentration of other isotopes in the item. The software can also determine the isotopic distribution of uranium isotopes in items containing only uranium. The body of this manual descnies the generic version of the code. Special facility-specific enhancements, if they apply, will be described in the appendices. The information in this manual applies equally well to version 3.3, which has been licensed to ORTEC. The software can analyze data that is stored in a file on disk. It understands several storage formats including Canberra's S1OO format, ORTEC'S `chn' and `SPC' formats, and several ASCII text formats. The software can also control data acquisition using an MCA and then store the results in a file on disk for later analysis or analyze the spectrum directly after the acquisition. The software currently only supports the control of ORTEC MCB'S. Support for Canbema's Genie-2000 Spectroscopy Systems will be added in the future. Support for reading and writing CAM files will also be forthcoming. A versatile parameter fde database structure governs all facets of the data analysis. User editing of the parameter sets allows great flexibility in handling data with different isotopic distributions, interfering isotopes, and different acquisition parameters such as energy calibration, and detector type. This manual is intended for the system supervisor or the local user who is to be the resident expert. Excerpts from this manual may also be appropriate for the system operator who will routinely use the instrument.

  16. Stop PC-aids from spreading through your PC—An early warning system

    NASA Astrophysics Data System (ADS)

    Uniyal, Parashu R.; Manglik, A.

    1993-02-01

    A new software system is presented that runs in an IBM PC/DOS environment immediately after the booting up stage, and provides an effective early warning of an infection by a virus. The system identifies all the users of a PC by their names, passwords, and booking codes. An authentication program performs characteristic diagnostic tests for the presence of boot and file viruses in addition to ensuring that access is provided only to authorized users. A record of login-logout times and results of viral diagnostics is appended to a log file. If there was a viral infection during a user session, access is denied at the time of next login with a display of the report on the last session. Thus corrective measures are prompted not only on the infected fixed disk, but also on that unwary user's floppies. The system includes programs that facilitate recovery from infection by viruses that are unknown to existing commercial scanners and therapy programs at an installation. The system has been effective in keeping the size of the virus epidemic under control at an installation with a minimum sacrifice of the comforts that a PC/DOS combination offers.

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

    PubMed Central

    2013-01-01

    Background 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). Results 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. Conclusion 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

  18. PC viruses: How do they do that

    SciTech Connect

    Pichnarczyk, K.

    1992-07-01

    The topic of PC Viruses has been an issue for a number of years now. They've been reported in every major newspaper, tabloids, television and radio. People from all fields get viruses: government, private sector businesses, home computers, schools, computer software suppliers. A definition is proposed to introduce the virus phenomenon. Virus authors come from a variety of communities. Motives and ideologies of authors are discussed, and examples of viruses are offered. Also mentioned is the growing number of viruses developed, isolated, and never distributed to the public at large, but kept within the antivirus research community. Virus examples are offered as well. Viruses are distributed not only through bulletin boards and shareware, but also from areas previously assumed to be safe, including the threat of receiving a virus through a standard in-house function, such as an in-house hardware maintenance shop. Three categories of viruses are presented: File Infecter viruses, Boot Sector Infecters, and the new category of Directory Entry Infecter virus. Also discussed are crossover viruses, that is, viruses which utilize a variety of techniques to ensure survival. An explanation of what is occurring within every stage of various viruses is given. Replication strategies common to all three types is noted, mainly the two different replication strategies of memory resident infecters and active selection infecters. A detailed definition, description and application of a stealth virus is presented. Detection strategies are discussed as each topic in this section is completed; a high level schemata of the operation of various virus detection programs ispresented. Since most eradication today is done using virus detection/eradication software, this paper attempts to reveal the techniques used by these packages.Included in the paper is the topic of manual eradication.

  19. PC viruses: How do they do that?

    SciTech Connect

    Pichnarczyk, K.

    1992-07-01

    The topic of PC Viruses has been an issue for a number of years now. They`ve been reported in every major newspaper, tabloids, television and radio. People from all fields get viruses: government, private sector businesses, home computers, schools, computer software suppliers. A definition is proposed to introduce the virus phenomenon. Virus authors come from a variety of communities. Motives and ideologies of authors are discussed, and examples of viruses are offered. Also mentioned is the growing number of viruses developed, isolated, and never distributed to the public at large, but kept within the antivirus research community. Virus examples are offered as well. Viruses are distributed not only through bulletin boards and shareware, but also from areas previously assumed to be safe, including the threat of receiving a virus through a standard in-house function, such as an in-house hardware maintenance shop. Three categories of viruses are presented: File Infecter viruses, Boot Sector Infecters, and the new category of Directory Entry Infecter virus. Also discussed are crossover viruses, that is, viruses which utilize a variety of techniques to ensure survival. An explanation of what is occurring within every stage of various viruses is given. Replication strategies common to all three types is noted, mainly the two different replication strategies of memory resident infecters and active selection infecters. A detailed definition, description and application of a stealth virus is presented. Detection strategies are discussed as each topic in this section is completed; a high level schemata of the operation of various virus detection programs ispresented. Since most eradication today is done using virus detection/eradication software, this paper attempts to reveal the techniques used by these packages.Included in the paper is the topic of manual eradication.

  20. Run-09 pC polarimeter analysis

    SciTech Connect

    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).

  1. Diagnostic Coding for Epilepsy.

    PubMed

    Williams, Korwyn; Nuwer, Marc R; Buchhalter, Jeffrey R

    2016-02-01

    Accurate coding is an important function of neurologic practice. This contribution to Continuum is part of an ongoing series that presents helpful coding information along with examples related to the issue topic. Tips for diagnosis coding, Evaluation and Management coding, procedure coding, or a combination are presented, depending on which is most applicable to the subject area of the issue.

  2. Model Children's Code.

    ERIC Educational Resources Information Center

    New Mexico Univ., Albuquerque. American Indian Law Center.

    The Model Children's Code was developed to provide a legally correct model code that American Indian tribes can use to enact children's codes that fulfill their legal, cultural and economic needs. Code sections cover the court system, jurisdiction, juvenile offender procedures, minor-in-need-of-care, and termination. Almost every Code section is…

  3. Phylogeny of genetic codes and punctuation codes within genetic codes.

    PubMed

    Seligmann, Hervé

    2015-03-01

    Punctuation codons (starts, stops) delimit genes, reflect translation apparatus properties. Most codon reassignments involve punctuation. Here two complementary approaches classify natural genetic codes: (A) properties of amino acids assigned to codons (classical phylogeny), coding stops as X (A1, antitermination/suppressor tRNAs insert unknown residues), or as gaps (A2, no translation, classical stop); and (B) considering only punctuation status (start, stop and other codons coded as -1, 0 and 1 (B1); 0, -1 and 1 (B2, reflects ribosomal translational dynamics); and 1, -1, and 0 (B3, starts/stops as opposites)). All methods separate most mitochondrial codes from most nuclear codes; Gracilibacteria consistently cluster with metazoan mitochondria; mitochondria co-hosted with chloroplasts cluster with nuclear codes. Method A1 clusters the euplotid nuclear code with metazoan mitochondria; A2 separates euplotids from mitochondria. Firmicute bacteria Mycoplasma/Spiroplasma and Protozoan (and lower metazoan) mitochondria share codon-amino acid assignments. A1 clusters them with mitochondria, they cluster with the standard genetic code under A2: constraints on amino acid ambiguity versus punctuation-signaling produced the mitochondrial versus bacterial versions of this genetic code. Punctuation analysis B2 converges best with classical phylogenetic analyses, stressing the need for a unified theory of genetic code punctuation accounting for ribosomal constraints.

  4. PC/FRAM: New capabilities for the gamma-ray spectrometry measurement of plutonium isotopic composition

    SciTech Connect

    Sampson, T.E.; Kelley, T.A.; Cremers, T.L.; Konkel, T.R.; Friar, R.J.

    1995-10-01

    We describe the new capability of and.present measurement results from the PC/FRAM plutonium isotopic analysis code. This new code allows data acquisition from a single coaxial germanium detector and analysis over an energy range from 120 keV to above I MeV. For the first time we demonstrate a complete isotopic analysis using only gamma rays greater than 200 keV in energy. This new capability allows the measurement of the plutonium isotopic composition of items inside shielded or heavy-walled containers without having to remove the items from the container. This greatly enhances worker safety by reducing handling and the resultant radiation exposure. Another application allows international inspectors to verify the contents of items inside sealed, long-term storage containers that may not be opened for national security or treaty compliance reasons. We present measurement results for traditional planar germanium detectors as well as coaxial detectors measuring shielded and unshielded samples.

  5. A decrease of intracellular ATP is compensated by increased respiration and acidification at sub-lethal parathion concentrations in murine embryonic neuronal cells: measurements in metabolic cell-culture chips.

    PubMed

    Buehler, S M; Stubbe, M; Gimsa, U; Baumann, W; Gimsa, J

    2011-11-30

    We present a label-free in vitro method for testing the toxic potentials of chemical substances using primary neuronal cells. The cells were prepared from 16-day-old NMRI mouse embryos and cultured on silicon chips (www.bionas.de) under the influence of different parathion concentrations with sensors for respiration (Clark-type oxygen electrodes), acidification (pH-ISFETs) and cell adhesion (interdigitated electrode structures, IDES). After 12 days in vitro, the sensor readouts were simultaneously recorded for 350 min in the presence of parathion applying a serial 1:3 dilution. The parathion-dependent data was fitted by logistic functions. IC(50) values of approximately 105 μM, 65 μM, and 54 μM were found for respiration, acidification, and adhesion, respectively. An IC(50) value of approximately 36 μM was determined from the intracellular ATP-levels of cells, which were detected by an ATP-luminescence assay using micro-well plates. While the intracellular ATP level and cell adhesion showed no deviation from a simple logistic decay, increases of approximately 29% in the respiration and 15% in the acidification rates above the control values were found at low parathion concentrations, indicating hormesis. These increases could be fitted by a modified logistic function. We believe that the label-free, continuous, multi-parametric monitoring of cell-metabolic processes may have applications in systems-biology and biomedical research, as well as in environmental monitoring. The parallel characterization of IC(50) values and hormetic effects may provide new insights into the metabolic mechanisms of toxic challenges to the cell.

  6. Top ten inpatient palliative medicine billing and coding mistakes (and how to fix them this week).

    PubMed

    Jones, Christopher A; Bull, Janet; Acevedo, Jean; Kamal, Arif H

    2015-03-01

    Palliative care (PC) has undergone incredible growth in the last 10 years, having gained subspecialty status and penetration into 85% of hospitals over 300 beds. The comprehensive services provided by multiple members of the PC team combined with low reimbursement for nonprocedural medical care challenges all PC teams to operate with financial sustainability. Accurately and compliantly documenting and coding services provided to patients can help to maximize PC programs' revenues and limit operating subsidies received from health care systems or hospice programs. In this article we share common billing and coding mistakes made by our programs and colleagues while providing inpatient, consultative palliative care. Each mistake is explained and paired with a straightforward fix to enable compliant, efficient practice. This will allow clinicians to more accurately communicate to payers the complex care provided to inpatients by the PC team. This fuller picture of the complexity of care provided can increase reimbursements received by your PC program from payers. Understanding how to accurately document, code, and receive appropriate reimbursement will allow our field to continue to grow, broadening the reach of PC nationally to improve quality of life for all patients and families in need.

  7. ISTUM PC: industrial sector technology use model for the IBM-PC

    SciTech Connect

    Roop, J.M.; Kaplan, D.T.

    1984-09-01

    A project to improve and enhance the Industrial Sector Technology Use Model (ISTUM) was originated in the summer of 1983. The project had dix identifiable objectives: update the data base; improve run-time efficiency; revise the reference base case; conduct case studies; provide technical and promotional seminars; and organize a service bureau. This interim report describes which of these objectives have been met and which tasks remain to be completed. The most dramatic achievement has been in the area of run-time efficiency. From a model that required a large proportion of the total resources of a mainframe computer and a great deal of effort to operate, the current version of the model (ISTUM-PC) runs on an IBM Personal Computer. The reorganization required for the model to run on a PC has additional advantages: the modular programs are somewhat easier to understand and the data base is more accessible and easier to use. A simple description of the logic of the model is given in this report. To generate the necessary funds for completion of the model, a multiclient project is proposed. This project will extend the industry coverage to all the industrial sectors, including the construction of process flow models for chemicals and petroleum refining. The project will also calibrate this model to historical data and construct a base case and alternative scenarios. The model will be delivered to clients and training provided. 2 references, 4 figures, 3 tables.

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

    NASA Technical Reports Server (NTRS)

    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.

  9. Accumulate repeat accumulate codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative channel coding scheme called 'Accumulate Repeat Accumulate codes' (ARA). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes, thus belief propagation can be used for iterative decoding of ARA codes on a graph. The structure of encoder for this class can be viewed as precoded Repeat Accumulate (RA) code or as precoded Irregular Repeat Accumulate (IRA) code, where simply an accumulator is chosen as a precoder. Thus ARA codes have simple, and very fast encoder structure when they representing LDPC codes. Based on density evolution for LDPC codes through some examples for ARA codes, we show that for maximum variable node degree 5 a minimum bit SNR as low as 0.08 dB from channel capacity for rate 1/2 can be achieved as the block size goes to infinity. Thus based on fixed low maximum variable node degree, its threshold outperforms not only the RA and IRA codes but also the best known LDPC codes with the dame maximum node degree. Furthermore by puncturing the accumulators any desired high rate codes close to code rate 1 can be obtained with thresholds that stay close to the channel capacity thresholds uniformly. Iterative decoding simulation results are provided. The ARA codes also have projected graph or protograph representation that allows for high speed decoder implementation.

  10. Concatenated Coding Using Trellis-Coded Modulation

    NASA Technical Reports Server (NTRS)

    Thompson, Michael W.

    1997-01-01

    In the late seventies and early eighties a technique known as Trellis Coded Modulation (TCM) was developed for providing spectrally efficient error correction coding. Instead of adding redundant information in the form of parity bits, redundancy is added at the modulation stage thereby increasing bandwidth efficiency. A digital communications system can be designed to use bandwidth-efficient multilevel/phase modulation such as Amplitude Shift Keying (ASK), Phase Shift Keying (PSK), Differential Phase Shift Keying (DPSK) or Quadrature Amplitude Modulation (QAM). Performance gain can be achieved by increasing the number of signals over the corresponding uncoded system to compensate for the redundancy introduced by the code. A considerable amount of research and development has been devoted toward developing good TCM codes for severely bandlimited applications. More recently, the use of TCM for satellite and deep space communications applications has received increased attention. This report describes the general approach of using a concatenated coding scheme that features TCM and RS coding. Results have indicated that substantial (6-10 dB) performance gains can be achieved with this approach with comparatively little bandwidth expansion. Since all of the bandwidth expansion is due to the RS code we see that TCM based concatenated coding results in roughly 10-50% bandwidth expansion compared to 70-150% expansion for similar concatenated scheme which use convolution code. We stress that combined coding and modulation optimization is important for achieving performance gains while maintaining spectral efficiency.

  11. Coset Codes Viewed as Terminated Convolutional Codes

    NASA Technical Reports Server (NTRS)

    Fossorier, Marc P. C.; Lin, Shu

    1996-01-01

    In this paper, coset codes are considered as terminated convolutional codes. Based on this approach, three new general results are presented. First, it is shown that the iterative squaring construction can equivalently be defined from a convolutional code whose trellis terminates. This convolutional code determines a simple encoder for the coset code considered, and the state and branch labelings of the associated trellis diagram become straightforward. Also, from the generator matrix of the code in its convolutional code form, much information about the trade-off between the state connectivity and complexity at each section, and the parallel structure of the trellis, is directly available. Based on this generator matrix, it is shown that the parallel branches in the trellis diagram of the convolutional code represent the same coset code C(sub 1), of smaller dimension and shorter length. Utilizing this fact, a two-stage optimum trellis decoding method is devised. The first stage decodes C(sub 1), while the second stage decodes the associated convolutional code, using the branch metrics delivered by stage 1. Finally, a bidirectional decoding of each received block starting at both ends is presented. If about the same number of computations is required, this approach remains very attractive from a practical point of view as it roughly doubles the decoding speed. This fact is particularly interesting whenever the second half of the trellis is the mirror image of the first half, since the same decoder can be implemented for both parts.

  12. PC-SPES (PDQ®)—Health Professional Version

    Cancer.gov

    Expert-reviewed information summary about the use of PC-SPES as a treatment for prostate cancer. Note: The information in this summary is no longer being updated and is provided for reference purposes only.

  13. OCEAN-PC and a distributed network for ocean data

    NASA Technical Reports Server (NTRS)

    Mclain, Douglas R.

    1992-01-01

    The Intergovernmental Oceanographic Commission (IOC) wishes to develop an integrated software package for oceanographic data entry and access in developing countries. The software, called 'OCEAN-PC', would run on low cost PC microcomputers and would encourage and standardize: (1) entry of local ocean observations; (2) quality control of the local data; (3) merging local data with historical data; (4) improved display and analysis of the merged data; and (5) international data exchange. OCEAN-PC will link existing MS-DOS oceanographic programs and data sets with table-driven format conversions. Since many ocean data sets are now being distributed on optical discs (Compact Discs - Read Only Memory, CD-ROM, Mass et al. 1987), OCEAN-PC will emphasize access to CD-ROMs.

  14. PC-SPES (PDQ®)—Patient Version

    Cancer.gov

    Expert-reviewed information summary about the use of PC-SPES as a treatment for prostate cancer. Note: The information in this summary is no longer being updated and is provided for reference purposes only.

  15. Software Reviews. PC Software for Artificial Intelligence Applications.

    ERIC Educational Resources Information Center

    Epp, Helmut; And Others

    1988-01-01

    Contrasts artificial intelligence and conventional programming languages. Reviews Personal Consultant Plus, Smalltalk/V, and Nexpert Object, which are PC-based products inspired by problem-solving paradigms. Provides information on background and operation of each. (RT)

  16. Single-event upset in advanced PowerPC microprocessors

    NASA Technical Reports Server (NTRS)

    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.

  17. Discussion on LDPC Codes and Uplink Coding

    NASA Technical Reports Server (NTRS)

    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.

  18. AERO2S - SUBSONIC AERODYNAMIC ANALYSIS OF WINGS WITH LEADING- AND TRAILING-EDGE FLAPS IN COMBINATION WITH CANARD OR HORIZONTAL TAIL SURFACES (IBM PC VERSION)

    NASA Technical Reports Server (NTRS)

    Carlson, H. W.

    1994-01-01

    necessary only to add an identification record and the namelist data that are to be changed from the previous run. This code was originally developed in 1989 in FORTRAN V on a CDC 6000 computer system, and was later ported to an MS-DOS environment. Both versions are available from COSMIC. There are only a few differences between the PC version (LAR-14458) and CDC version (LAR-14178) of AERO2S distributed by COSMIC. The CDC version has one main source code file while the PC version has two files which are easier to edit and compile on a PC. The PC version does not require a FORTRAN compiler which supports NAMELIST because a special INPUT subroutine has been added. The CDC version includes two MODIFY decks which can be used to improve the code and prevent the possibility of some infrequently occurring errors while PC-version users will have to make these code changes manually. The PC version includes an executable which was generated with the Ryan McFarland/FORTRAN compiler and requires 253K RAM and an 80x87 math co-processor. Using this executable, the sample case requires about four hours to execute on an 8MHz AT-class microcomputer with a co-processor. The source code conforms to the FORTRAN 77 standard except that it uses variables longer than six characters. With two minor modifications, the PC version should be portable to any computer with a FORTRAN compiler and sufficient memory. The CDC version of AERO2S is available in CDC NOS Internal format on a 9-track 1600 BPI magnetic tape. The PC version is available on a set of two 5.25 inch 360K MS-DOS format diskettes. IBM AT is a registered trademark of International Business Machines. MS-DOS is a registered trademark of Microsoft Corporation. CDC is a registered trademark of Control Data Corporation. NOS is a trademark of Control Data Corporation.

  19. Bar Codes for Libraries.

    ERIC Educational Resources Information Center

    Rahn, Erwin

    1984-01-01

    Discusses the evolution of standards for bar codes (series of printed lines and spaces that represent numbers, symbols, and/or letters of alphabet) and describes the two types most frequently adopted by libraries--Code-A-Bar and CODE 39. Format of the codes is illustrated. Six references and definitions of terminology are appended. (EJS)

  20. Manually operated coded switch

    DOEpatents

    Barnette, Jon H.

    1978-01-01

    The disclosure relates to a manually operated recodable coded switch in which a code may be inserted, tried and used to actuate a lever controlling an external device. After attempting a code, the switch's code wheels must be returned to their zero positions before another try is made.

  1. A PC-Windows-Based program for geostatistical modeling application

    SciTech Connect

    Wu, G.G.; Yang, A.P.

    1994-12-31

    This paper describes a technically advanced, user-friendly, PC-Windows{sup TM} based reservoir simulation tool (SIMTOOLS) that allows construction of realistic reservoir models using a geostatistical approach. This PC-Windows based product has three application tools: Digitizing, mapping, and geostatistics. It has been designed primarily to enable reservoir engineers to apply the geostatistical gridding technique in mapping and reservoir simulation practices.

  2. Wf/pc Cycle 3 Calibration: Rapid Internal Monitor

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1992-06-01

    This test is to take repeated internal flats to test for contamination buildup on the optical surfaces or the reappearance of QEH. Part 1: INTFLATS in F555W are obtained every 4 days in both WFC and PC to check for measles or daisies and to monitor scattered light. Part 2: Sequential INTFLATS in F439W with PC are obtained every 7 days to check for QEH.

  3. Wf/pc Cycle 2 Calibration: Rapid Internal Monitor

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1991-07-01

    This test is to take repeated internal flats to test for contamination buildup on the optical surfaces or the reappearance of QEH. Part 1: INTFLATS in F555W are obtained every 4 days in both WFC and PC to check for measles or daisies and to monitor scattered light. Part 2: Sequential INTFLATS in F439W with PC are obtained every 7 days to check for QEH.

  4. Wf/pc Cycle 1 Calibration: Rapid Internal Monitor

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1990-12-01

    This test is to take repeated internal flats to test for contamination buildup on the optical surfaces or the reappearance of QEH. Part 1: INTFLATS in F555W are obtained every 4 days in both WFC and PC to check for measles or daisies and to monitor scattered light. Part 2: Sequential INTFLATS in F439W with PC are obtained every 7 days to check for QEH.

  5. Unraveling the neuroprotective mechanisms of PrPC in excitotoxicity

    PubMed Central

    Llorens, Franc; del Río, José Antonio

    2012-01-01

    Knowledge of the natural roles of cellular prion protein (PrPC) is essential to an understanding of the molecular basis of prion pathologies. This GPI-anchored protein has been described in synaptic contacts, and loss of its synaptic function in complex systems may contribute to the synaptic loss and neuronal degeneration observed in prionopathy. In addition, Prnp knockout mice show enhanced susceptibility to several excitotoxic insults, GABAA receptor-mediated fast inhibition was weakened, LTP was modified and cellular stress increased. Although little is known about how PrPC exerts its function at the synapse or the downstream events leading to PrPC-mediated neuroprotection against excitotoxic insults, PrPC has recently been reported to interact with two glutamate receptor subunits (NR2D and GluR6/7). In both cases the presence of PrPC blocks the neurotoxicity induced by NMDA and Kainate respectively. Furthermore, signals for seizure and neuronal cell death in response to Kainate in Prnp knockout mouse are associated with JNK3 activity, through enhancing the interaction of GluR6 with PSD-95. In combination with previous data, these results shed light on the molecular mechanisms behind the role of PrPC in excitotoxicity. Future experimental approaches are suggested and discussed. PMID:22437735

  6. Photodynamic therapy with Pc 4 induces apoptosis of Candida albicans.

    PubMed

    Lam, Minh; Jou, Paul C; Lattif, Ali A; Lee, Yoojin; Malbasa, Christi L; Mukherjee, Pranab K; Oleinick, Nancy L; Ghannoum, Mahmoud A; Cooper, Kevin D; Baron, Elma D

    2011-01-01

    The high prevalence of drug resistance necessitates the development of novel antifungal agents against infections caused by opportunistic fungal pathogens, such as Candida albicans. Elucidation of apoptosis in yeast-like fungi may provide a basis for future therapies. In mammalian cells, photodynamic therapy (PDT) has been demonstrated to generate reactive oxygen species, leading to immediate oxidative modifications of biological molecules and resulting in apoptotic cell death. In this report, we assess the in vitro cytotoxicity and mechanism of PDT, using the photosensitizer Pc 4, in planktonic C. albicans. Confocal image analysis confirmed that Pc 4 localizes to cytosolic organelles, including mitochondria. A colony formation assay showed that 1.0 μM Pc 4 followed by light at 2.0 J cm(-2) reduced cell survival by 4 logs. XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxyanilide) assay revealed that Pc 4-PDT impaired fungal metabolic activity, which was confirmed using the FUN-1 (2-chloro-4-[2,3-dihydro-3-methyl-(benzo-1,3-thiazol-2-yl)-methylidene]-1-phenylquinolinium iodide) fluorescence probe. Furthermore, we observed changes in nuclear morphology characteristic of apoptosis, which were substantiated by increased externalization of phosphatidylserine and DNA fragmentation following Pc 4-PDT. These data indicate that Pc 4-PDT can induce apoptosis in C. albicans. Therefore, a better understanding of the process will be helpful, as PDT may become a useful treatment option for candidiasis.

  7. QR Codes 101

    ERIC Educational Resources Information Center

    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…

  8. ARA type protograph codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush (Inventor); Abbasfar, Aliazam (Inventor); Jones, Christopher R. (Inventor); Dolinar, Samuel J. (Inventor); Thorpe, Jeremy C. (Inventor); Andrews, Kenneth S. (Inventor); Yao, Kung (Inventor)

    2008-01-01

    An apparatus and method for encoding low-density parity check codes. Together with a repeater, an interleaver and an accumulator, the apparatus comprises a precoder, thus forming accumulate-repeat-accumulate (ARA codes). Protographs representing various types of ARA codes, including AR3A, AR4A and ARJA codes, are described. High performance is obtained when compared to the performance of current repeat-accumulate (RA) or irregular-repeat-accumulate (IRA) codes.

  9. Epitaxial growth and electronic properties of well ordered phthalocyanine heterojunctions MnPc/F{sub 16}CoPc

    SciTech Connect

    Lindner, Susi; Mahns, Benjamin; Treske, Uwe; Knupfer, Martin; Vilkov, Oleg; Haidu, Francisc; Fronk, Michael; Zahn, Dietrich R. T.

    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.

  10. PC Tutor. Bericht uber ein PC-gestutzes Tutorensystem = PC Tutor. Report on a Tutoring System with Personal Computer. ZIFF Papiere 75.

    ERIC Educational Resources Information Center

    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,…

  11. Simultaneous Determination of Parathion, Malathion, Diazinon, and Pirimiphos Methyl in Dried Medicinal Plants Using Solid-Phase Microextraction Fibre Coated with Single-Walled Carbon Nanotubes

    PubMed Central

    Ahmadkhaniha, Reza; Samadi, Nasrin; Salimi, Mona; Sarkhail, Parisa; Rastkari, Noushin

    2012-01-01

    A reliable and sensitive headspace solid-phase microextraction gas chromatography-mass spectrometry method for simultaneous determination of different organophosphorus pesticides in dried medicinal plant samples is described. The analytes were extracted by single-walled carbon nanotubes as a new solid-phase microextraction adsorbent. The developed method showed good performance. For diazinon and pirimiphos methyl calibration, curves were linear (r2 ≥ 0.993) over the concentration ranges from 1.5 to 300 ng g−1, and the limit of detection at signal-to-noise ratio of 3 was 0.3 ng g−1. For parathion and malathion, the linear range and limit of detection were 2.5–300 (r2 ≥ 0.991) and 0.5 ng g−1, respectively. In addition, a comparative study between the single-walled carbon nanotubes and a commercial polydimethylsiloxane fibre for the determination of target analytes was carried out. Single-walled carbon nanotubes fibre showed higher extraction capacity, better thermal stability (over 350°C), and longer lifespan (over 250 times) than the commercial polydimethylsiloxane fibre. The developed method was successfully applied to determine target organophosphorus pesticides in real samples. PMID:22645439

  12. Extrapolating laboratory avian toxicity data to free-living birds: Comparison of the toxicity of parathion to captive and free-living European starlings

    USGS Publications Warehouse

    Grue, C.E.; Rattner, B.A.; Bunck, C.M.

    1993-01-01

    In 1985 and 1986, we captured nesting wild female European starlings with young 8-10 days of age. Birds were weighted, banded, and given one of four dosages of the OP insecticide parathion (50, 72, 104 or 150 mg/kg dissolved in corn oil) or pure corn-oil (control). and their young weighed. Nest boxes (7- 12/treatment) were observed and young re-weighed 2-3 days postdose to determine presence/absence of the females. If necessary, males were captured and fate of young used to confirm female response. Brain ChE inhibition in dosed birds (based on a pilot study) was 55-74%. EC50's (failure to return to nest box) for the females was 74 mg/kg in 1985 and 92 mg/kg in 1986. Confidence limit (95%) for these estimates overlapped LD50's for captive female starlings dosed with the OP in spring and early summer 1987 (136, 128 mg/kg, respectively). Results suggest that responses of captive and free-living birds to potentially lethal concentrations of OP's are similar, despite the additional stresses in the wild.

  13. An optical microplate biosensor for the detection of methyl parathion pesticide using a biohybrid of Sphingomonas sp. cells-silica nanoparticles.

    PubMed

    Mishra, Archana; Kumar, Jitendra; Melo, Jose Savio

    2017-01-15

    The previously developed Sphingomonas sp. based optical microplate biosensor for methyl parathion (MP) was good as it detected multiple samples but had poor stability and low sensitivity. The present study aims to overcome these limitations. Silica nanoparticles (Si NP) were thus functionalized with polyethyleneimine (PEI) and the functionalized silica nanoparticles ((f)Si NP) were then integrated with Sphingomonas sp. cells. The process was optimized for hydrolysis of MP into p-nitrophenol (PNP). Integration of (f)Si NP with cells was confirmed by FT-IR analysis. Biohybrid of Sphingomonas sp.-(f)Si NP was immobilized on the wells of microplate and associated directly with the optical transducer of microplate reader. Immobilized biohybrid of Sphingomonas sp.-(f)Si NP was characterized using SEM. A detection range of 0.1-1ppm MP was achieved from the linear range of calibration plot. After integration with (f)Si NP the storage stability of biohybrid was enhanced ten times from 18 to 180 days. This study proves that after interaction of cells with (f)Si NP, improved the sensitivity and stability of the biosensor. Spiked samples were also analyzed and correlated using this biohybrid based biosensor.

  14. Genetically engineered Pseudomonas putida X3 strain and its potential ability to bioremediate soil microcosms contaminated with methyl parathion and cadmium.

    PubMed

    Zhang, Rong; Xu, Xingjian; Chen, Wenli; Huang, Qiaoyun

    2016-02-01

    A multifunctional Pseudomonas putida X3 strain was successfully engineered by introducing methyl parathion (MP)-degrading gene and enhanced green fluorescent protein (EGFP) gene in P. putida X4 (CCTCC: 209319). In liquid cultures, the engineered X3 strain utilized MP as sole carbon source for growth and degraded 100 mg L(-1) of MP within 24 h; however, this strain did not further metabolize p-nitrophenol (PNP), an intermediate metabolite of MP. No discrepancy in minimum inhibitory concentrations (MICs) to cadmium (Cd), copper (Cu), zinc (Zn), and cobalt (Co) was observed between the engineered X3 strain and its host strain. The inoculated X3 strain accelerated MP degradation in different polluted soil microcosms with 100 mg MP kg(-1) dry soil and/or 5 mg Cd kg(-1) dry soil; MP was completely eliminated within 40 h. However, the presence of Cd in the early stage of remediation slightly delayed MP degradation. The application of X3 strain in Cd-contaminated soil strongly affected the distribution of Cd fractions and immobilized Cd by reducing bioavailable Cd concentrations with lower soluble/exchangeable Cd and organic-bound Cd. The inoculated X3 strain also colonized and proliferated in various contaminated microcosms. Our results suggested that the engineered X3 strain is a potential bioremediation agent showing competitive advantage in complex contaminated environments.

  15. Analysis of bacteria degradation products of methyl parathion by liquid chromatography/electrospray time-of-flight mass spectrometry and gas chromatography/mass spectrometry.

    PubMed

    Liu, Jie; Wang, Ling; Zheng, Li; Wang, Xiaoru; Lee, Frank S C

    2006-12-29

    The biodegradation of the organophosphorus insecticide methyl parathion (MP) in aqueous environment by bacteria isolated from river sediment has been studied. Two species of bacteria which show strong MP degradation ability are identified as Shewanella and Vibrio parahaemolyticus. The biodegradation of MP proceeded rapidly with the formation of a series of intermediate products, which were analyzed using a combination of GC/MS and HPLC/ESI-TOFMS techniques. The major products tentatively identified include a series of reduced products of MP. Results demonstrate that the coupling of TOFMS to HPLC enhances further the capability of LC-MS in the identification of polar organic species in complex environmental samples. Degradation pathways leading to the formation of these products are proposed which involves first the reduction of nitro to amino group in MP, followed by combination with some intrinsic matters of bacteria. The mechanism and products from biodegradation are quite different from those of photocatalytic process for which the main intermediates included methyl paraoxon and 4-nitrophenol.

  16. Efficient entropy coding for scalable video coding

    NASA Astrophysics Data System (ADS)

    Choi, Woong Il; Yang, Jungyoup; Jeon, Byeungwoo

    2005-10-01

    The standardization for the scalable extension of H.264 has called for additional functionality based on H.264 standard to support the combined spatio-temporal and SNR scalability. For the entropy coding of H.264 scalable extension, Context-based Adaptive Binary Arithmetic Coding (CABAC) scheme is considered so far. In this paper, we present a new context modeling scheme by using inter layer correlation between the syntax elements. As a result, it improves coding efficiency of entropy coding in H.264 scalable extension. In simulation results of applying the proposed scheme to encoding the syntax element mb_type, it is shown that improvement in coding efficiency of the proposed method is up to 16% in terms of bit saving due to estimation of more adequate probability model.

  17. Polycomb group protein gene silencing, non-coding RNA, stem cells, and cancer.

    PubMed

    Gieni, Randall S; Hendzel, Michael J

    2009-10-01

    Epigenetic programming is an important facet of biology, controlling gene expression patterns and the choice between developmental pathways. The Polycomb group proteins (PcGs) silence gene expression, allowing cells to both acquire and maintain identity. PcG silencing is important for stemness, X chromosome inactivation (XCI), genomic imprinting, and the abnormally silenced genes in cancers. Stem and cancer cells commonly share gene expression patterns, regulatory mechanisms, and signalling pathways. Many microRNA species have oncogenic or tumor suppressor activity, and disruptions in these networks are common in cancer; however, long non-coding (nc)RNA species are also important. Many of these directly guide PcG deposition and gene silencing at the HOX locus, during XCI, and in examples of genomic imprinting. Since inappropriate HOX expression and loss of genomic imprinting are hallmarks of cancer, disruption of long ncRNA-mediated PcG silencing likely has a role in oncogenesis. Aberrant silencing of coding and non-coding loci is critical for both the genesis and progression of cancers. In addition, PcGs are commonly abnormally overexpressed years prior to cancer pathology, making early PcG targeted therapy an option to reverse tumor formation, someday replacing the blunt instrument of eradication in the cancer therapy arsenal.

  18. GABAA receptor-mediated feedforward and feedback inhibition differentially modulate the gain and the neural code transformation in hippocampal CA1 pyramidal cells.

    PubMed

    Jang, Hyun Jae; Park, Kyerl; Lee, Jaedong; Kim, Hyuncheol; Han, Kyu Hun; Kwag, Jeehyun

    2015-12-01

    Diverse variety of hippocampal interneurons exists in the CA1 area, which provides either feedforward (FF) or feedback (FB) inhibition to CA1 pyramidal cell (PC). However, how the two different inhibitory network architectures modulate the computational mode of CA1 PC is unknown. By investigating the CA3 PC rate-driven input-output function of CA1 PC using in vitro electrophysiology, in vitro-simulation of inhibitory network, and in silico computational modeling, we demonstrated for the first time that GABAA receptor-mediated FF and FB inhibition differentially modulate the gain, the spike precision, the neural code transformation and the information capacity of CA1 PC. Recruitment of FF inhibition buffered the CA1 PC spikes to theta-frequency regardless of the input frequency, abolishing the gain and making CA1 PC insensitive to its inputs. Instead, temporal variability of the CA1 PC spikes was increased, promoting the rate-to-temporal code transformation to enhance the information capacity of CA1 PC. In contrast, the recruitment of FB inhibition sub-linearly transformed the input rate to spike output rate with high gain and low spike temporal variability, promoting the rate-to-rate code transformation. These results suggest that GABAA receptor-mediated FF and FB inhibitory circuits could serve as network mechanisms for differentially modulating the gain of CA1 PC, allowing CA1 PC to switch between different computational modes using rate and temporal codes ad hoc. Such switch will allow CA1 PC to efficiently respond to spatio-temporally dynamic inputs and expand its computational capacity during different behavioral and neuromodulatory states in vivo.

  19. Ternary phase diagram of dipalmitoyl-PC/dilauroyl-PC/cholesterol: nanoscopic domain formation driven by cholesterol.

    PubMed Central

    Feigenson, G W; Buboltz, J T

    2001-01-01

    A ternary phase diagram is proposed for the hydrated lamellar lipid mixture dipalmitoylphosphatidylcholine/dilauroylphosphatidylcholine/cholesterol (DPPC/DLPC/cholesterol) at room temperature. The entire composition space has been thoroughly mapped by complementary experimental techniques, revealing interesting phase behavior that has not been previously described. Confocal fluorescence microscopy shows a regime of coexisting DPPC-rich ordered and DLPC-rich fluid lamellar phases, having an upper boundary at apparently constant cholesterol mole fraction chi(chol) approximately 0.16. Fluorescence resonance energy transfer experiments confirm the identification and extent of this two-phase regime and, furthermore, reveal a 1-phase regime between chi(chol) approximately 0.16 and 0.25, consisting of ordered and fluid nanoscopic domains. Dipyrene-PC excimer/monomer measurements confirm the new regime between chi(chol) approximately 0.16 and 0.25 and also show that rigidly ordered phases seem to disappear around chi(chol) approximately 0.25. This study should be considered as a step toward a more complete understanding of lateral heterogeneity within biomembranes. Cholesterol may play a role in domain separation on the nanometer scale. PMID:11371452

  20. TOUGH+ v1.5 Core Code

    SciTech Connect

    Moridis, George J.

    2015-08-27

    TOUGH+ v1.5 is a numerical code for the simulation of multi-phase, multi-component flow and transport of mass and heat through porous and fractured media, and represents the third update of the code since its first release [Moridis et al., 2008]. TOUGH+ is a successor to the TOUGH2 [Pruess et al., 1991; 2012] family of codes for multi-component, multiphase fluid and heat flow developed at the Lawrence Berkeley National Laboratory. It is written in standard FORTRAN 95/2003, and can be run on any computational platform (workstations, PC, Macintosh). TOUGH+ v1.5 employs dynamic memory allocation, thus minimizing storage requirements. It has a completely modular structure, follows the tenets of Object-Oriented Programming (OOP), and involves the advanced features of FORTRAN 95/2003, i.e., modules, derived data types, the use of pointers, lists and trees, data encapsulation, defined operators and assignments, operator extension and overloading, use of generic procedures, and maximum use of the powerful intrinsic vector and matrix processing operations. TOUGH+ v1.5 is the core code for its family of applications, i.e., the part of the code that is common to all its applications. It provides a description of the underlying physics and thermodynamics of non-isothermal flow, of the mathematical and numerical approaches, as well as a detailed explanation of the general (common to all applications) input requirements, options, capabilities and output specifications. The core code cannot run by itself: it needs to be coupled with the code for the specific TOUGH+ application option that describes a particular type of problem. The additional input requirements specific to a particular TOUGH+ application options and related illustrative examples can be found in the corresponding User’s Manual.

  1. Association study between CAG trinucleotide repeats in the PCQAP gene (PC2 glutamine/Q-rich-associated protein) and schizophrenia.

    PubMed

    De Luca, Alessandro; Conti, Emanuela; Grifone, Nicoletta; Amati, Francesca; Spalletta, Gianfranco; Caltagirone, Carlo; Bonaviri, Giuseppina; Pasini, Augusto; Gennarelli, Massimo; Stefano, Bignotti; Berti, Lucia; Mittler, Gerhard; Meisterernst, Michael; Dallapiccola, Bruno; Novelli, Giuseppe

    2003-01-01

    Schizophrenia or schizoaffective disorders are quite common features in patients with DiGeorge/velocardiofacial syndrome (DGS/VCFS) as a result of hemizygosity of chromosome 22q11.2. We evaluated the PCQAP gene, which maps within the DGS/VCFS interval, as a potential candidate for schizophrenia susceptibility. PCQAP encodes for a subunit of the large multiprotein complex PC2, which exhibits a coactivator function in RNA polymerase II mediated transcription. Using a case-control study, we searched association between schizophrenia and the intragenic coding trinucleotide polymorphism. The distribution of the CAG repeat alleles was significantly different between patients and controls with the Mann-Whitney test (z = -2.5694, P = 0.0051; schizophrenics: n = 378, W = 161,002.5, Mean rank = 425.9325; controls: n = 444, W = 177,250.5, Mean rank = 399.2128). This result may indicate a possible involvement of the multiprotein complex PC2 in schizophrenia susceptibility.

  2. Honesty and Honor Codes.

    ERIC Educational Resources Information Center

    McCabe, Donald; Trevino, Linda Klebe

    2002-01-01

    Explores the rise in student cheating and evidence that students cheat less often at schools with an honor code. Discusses effective use of such codes and creation of a peer culture that condemns dishonesty. (EV)

  3. QR Code Mania!

    ERIC Educational Resources Information Center

    Shumack, Kellie A.; Reilly, Erin; Chamberlain, Nik

    2013-01-01

    space, has error-correction capacity, and can be read from any direction. These codes are used in manufacturing, shipping, and marketing, as well as in education. QR codes can be created to produce…

  4. DIANE multiparticle transport code

    NASA Astrophysics Data System (ADS)

    Caillaud, M.; Lemaire, S.; Ménard, S.; Rathouit, P.; Ribes, J. C.; Riz, D.

    2014-06-01

    DIANE is the general Monte Carlo code developed at CEA-DAM. DIANE is a 3D multiparticle multigroup code. DIANE includes automated biasing techniques and is optimized for massive parallel calculations.

  5. Demonstration of a PC 25 Fuel Cell in Russia

    SciTech Connect

    John C. Trocciola; Thomas N. Pompa; Linda S. Boyd

    2004-09-01

    This project involved the installation of a 200kW PC25C{trademark} phosphoric-acid fuel cell power plant at Orgenergogaz, a Gazprom industrial site in Russia. In April 1997, a PC25C{trademark} was sold by ONSI Corporation to Orgenergogaz, a subsidiary of the Russian company ''Gazprom''. Due to instabilities in the Russian financial markets, at that time, the unit was never installed and started by Orgenergogaz. In October of 2001 International Fuel Cells (IFC), now known as UTC Fuel Cells (UTCFC), received a financial assistance award from the United States Department of Energy (DOE) entitled ''Demonstration of PC 25 Fuel Cell in Russia''. Three major tasks were part of this award: the inspection of the proposed site and system, start-up assistance, and installation and operation of the powerplant.

  6. Aspartame-induced apoptosis in PC12 cells.

    PubMed

    Horio, Yukari; Sun, Yongkun; Liu, Chuang; Saito, Takeshi; Kurasaki, Masaaki

    2014-01-01

    Aspartame is an artificial sweetner added to many low-calorie foods. The safety of aspartame remains controversial even though there are many studies on its risks. In this study, to understand the physiological effects of trace amounts of artificial sweetners on cells, the effects of aspartame on apoptosis were investigated using a PC12 cell system. In addition, the mechanism of apoptosis induced by aspartame in PC12 cells and effects on apoptotic factors such as cytochrome c, apoptosis-inducing factor, and caspase family proteins were studied by Western blotting and RT-PCR. Aspartame-induced apoptosis in PC12 cells in a dose-dependent manner. In addition, aspartame exposure increased the expressions of caspases 8 and 9, and cytochrome c. These results indicate that aspartame induces apoptosis mainly via mitochondrial pathway involved in apoptosis due to oxigen toxicity.

  7. Expression of dystrophin Dp71 during PC12 cell differentiation.

    PubMed

    Cisneros, B; Rendon, A; Genty, V; Aranda, G; Marquez, F; Mornet, D; Montañez, C

    1996-08-02

    The expression of dystrophin-protein 71 (Dp71) was investigated during nerve growth factor (NGF) induced differentiation of PC12 cells. A semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) assay was designed to measure Dp71 mRNA, whereas the Dp71 protein amount was evaluated by immunoblot analysis using an anti-dystrophin monoclonal antibody. Comparison with control cultures showed that Dp71 mRNA and protein levels increased in parallel with NGF treatment peaking with increments of 60% and 1.4 times, respectively. The upregulation of Dp71 expression during PC12 cells differentiation point at PC12 cells as a suitable model for studying the function of Dp71 in neuronal cells.

  8. Modelling of Pc5 pulsation structure in the magnetosphere

    NASA Astrophysics Data System (ADS)

    Walker, A. D. M.

    1980-03-01

    Magnetohydrodynamic resonance theory is used to model the structure of the magnetospheric and ionospheric electric and magnetic fields associated with Pc5 geomagnetic pulsations. In this paper the variation of the fields across the invariant latitude of the resonance are computed. The results are combined with calculations of the variation along a field line to map the fields down to the ionosphere. In one case the results are compared with measurements obtained by the STARE auroral radar and show good agreement. The relationship between the width of the resonance region and ionospheric height-integrated Pedersen conductivity is computed and it is shown how auroral radar measurements of Pc5 oscillations could be used to determine ionospheric height-integrated Pedersen conductivity. It is pointed out that from these calculations it would be possible to identify the field line on which a satellite was located by comparing a Pc5 pulsation observed by the satellite, and the same pulsation observed by STARE.

  9. PC-1D installation manual and user's guide

    SciTech Connect

    Basore, P.A.

    1991-05-01

    PC-1D is a software package for personal computers that uses finite-element analysis to solve the fully-coupled two-carrier semiconductor transport equations in one dimension. This program is particularly useful for analyzing the performance of optoelectronic devices such as solar cells, but can be applied to any bipolar device whose carrier flows are primarily one-dimensional. This User's Guide provides the information necessary to install PC-1D, define a problem for solution, solve the problem, and examine the results. Example problems are presented which illustrate these steps. The physical models and numerical methods utilized are presented in detail. This document supports version 3.1 of PC-1D, which incorporates faster numerical algorithms with better convergence properties than previous versions of the program. 51 refs., 17 figs., 5 tabs.

  10. Tablet PC as a mobil PACS terminal using wireless LAN

    NASA Astrophysics Data System (ADS)

    Tsao, Bo-Shen; Ching, Yu-Tai; Lee, Wen-Jeng; Chen, Shyh-Jye; Chang, Chia-Hung; Chen, Chien-Jung; Yen, York; Lee, Yuan-Ten

    2003-05-01

    A PACS mobile terminal has applications in ward round, emergency room and remote teleradiology consultation. Personal Digital Assistants (PDAs) have the highest mobility and are used for many medical applications. However, their roles are limited in the field of radiology due to small screen size. In this study, we built a wireless PACS terminal using a hand-held tablet-PC. A tablet PC (X-pilot, LEO systems, Taiwan) running the WinCE operating systems was used as our mobile PACS terminal. This device is equipped with 800×600 resolution 10.4 inch TFT monitor. The network connection between the tablet PC and the server was linked via wireless LAN (IEEE 802.11b).

  11. EMF wire code research

    SciTech Connect

    Jones, T.

    1993-11-01

    This paper examines the results of previous wire code research to determines the relationship with childhood cancer, wire codes and electromagnetic fields. The paper suggests that, in the original Savitz study, biases toward producing a false positive association between high wire codes and childhood cancer were created by the selection procedure.

  12. Universal Noiseless Coding Subroutines

    NASA Technical Reports Server (NTRS)

    Schlutsmeyer, A. P.; Rice, R. F.

    1986-01-01

    Software package consists of FORTRAN subroutines that perform universal noiseless coding and decoding of integer and binary data strings. Purpose of this type of coding to achieve data compression in sense that coded data represents original data perfectly (noiselessly) while taking fewer bits to do so. Routines universal because they apply to virtually any "real-world" data source.

  13. Mapping Local Codes to Read Codes.

    PubMed

    Bonney, Wilfred; Galloway, James; Hall, Christopher; Ghattas, Mikhail; Tramma, Leandro; Nind, Thomas; Donnelly, Louise; Jefferson, Emily; Doney, Alexander

    2017-01-01

    Background & Objectives: Legacy laboratory test codes make it difficult to use clinical datasets for meaningful translational research, where populations are followed for disease risk and outcomes over many years. The Health Informatics Centre (HIC) at the University of Dundee hosts continuous biochemistry data from the clinical laboratories in Tayside and Fife dating back as far as 1987. However, the HIC-managed biochemistry dataset is coupled with incoherent sample types and unstandardised legacy local test codes, which increases the complexity of using the dataset for reasonable population health outcomes. The objective of this study was to map the legacy local test codes to the Scottish 5-byte Version 2 Read Codes using biochemistry data extracted from the repository of the Scottish Care Information (SCI) Store.

  14. Realizing broad-bandwidth visible wavelength photodiode based on solution-processed ZnPc/PC71BM dyad

    NASA Astrophysics Data System (ADS)

    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.

  15. Initial results in the development of a reporter cell line for toxicology studies at gene expression level: activation of the electrophile-responsive element by copper and methyl parathion.

    PubMed

    Almeida, Daniela Volcan; Trindade, Gilma Santos; Geracitano, Laura A; Barros, Daniela Martí; Monserrat, José Maria; Marins, Luis Fernando

    2008-07-01

    Induction of many genes encoding detoxifying enzymes and antioxidant proteins is mediated through a common mechanism, which is controlled by electrophile-responsive elements (EpRE) within the regulatory region of those genes. Copper and methyl parathion are environmental pollutants known to induce the expression of EpRE-mediated genes. In order to evaluate the molecular response triggered by these pollutants, a stable cell line was produced, which carries a transgene comprised of the green fluorescent protein (GFP) reporter gene under transcriptional control of the mouse glutathione-S-transferase (gst1) electrophile-responsive element fused to the mouse metallothionein (mt1) minimal promoter. The rat HTC hepatoma cells were transfected with the EpREmt-GFP construct and successfully selected with G418 antibiotic. EpREmt-GFP HTC cells were treated with 0.002 mg L(-1), 0.02 mg L(-1), 0.2 mg L(-1) and 2 mg L(-1) copper sulfate and 0.001 mg L(-1), 0.01 mg L(-1), 0.1 mg L(-1) and 1 mg L(-1) methyl parathion for 48 h. GFP expression was directly quantified in living cells using a microplate fluorimeter. GFP expression was significantly increased in higher concentrations of both pollutants, showing a 1.80- and 2.58-fold induction of GFP at 2mg copper L(-1) and 1mg methyl parathion L(-1), respectively (p<0.01). The results obtained in the present study demonstrate that the EpREmt-GFP HTC cell line can be an interesting model for further development for the study of the cellular response to aquatic pollutants as well as a new tool for environmental monitoring at the molecular level.

  16. Measure of 1/f noise using the sound card of a PC

    NASA Astrophysics Data System (ADS)

    Carlà, Marcello

    2016-04-01

    An experimental setup is described to measure 1/f noise (pink noise) in conductors using a PC equipped with a sound card functioning as a spectrum analyzer. A simple auxiliary analog electronic circuit with three operational amplifiers has been assembled to yield the required amplification, to match the sound card signal levels, and to implement a bridge configuration to improve dynamical range. Test experiments and data analysis have been conducted using commonly available software, together with some custom scripts and C code. The whole setup is technically accessible and economical for both the high school and undergraduate levels. Results are reported for pink noise of vintage carbon resistors spanning seven frequency decades, from 1 mHz to 10 kHz.

  17. Integrated Refractive Effects Prediction System (IREPS) User’s Manual. Revision PC-2.0

    DTIC Science & Technology

    1990-08-01

    COUERED BY U.S. PATENT 4,125,893 Naval Ocean Systems Center Code 543 San Diego, CA 92152-500 Con: 619-553-1428 AU: 553-1428 Fax: 619-553-1417 email; 543...PC-2.0 product to the automode recipe. CUST7flER.1 t D)el Ins: FI-1He F5-Enu F6-Sunru Fl- Couer FO-Loss Fl-Saue f Exit FZ-Exit W10 Saue f3-Frint F9-Toq...Diaqrams .m. F5-Enu COVER FOR SFS-AA F6-Sumrq OVER FOR APS-XX TR/hA ALT 1000 FT F7- Couer REMARK FO-Loss REMARK * Loss Diaqrams LOSS FOR SPS-AA RE/TA ALT

  18. Dynamic Analysis of Spur Gear Transmissions (DANST). PC Version 3.00 User Manual

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.; Lin, Hsiang Hsi; Delgado, Irebert R.

    1996-01-01

    DANST is a FORTRAN computer program for static and dynamic analysis of spur gear systems. The program can be used for parametric studies to predict the static transmission error, dynamic load, tooth bending stress and other properties of spur gears as they are influenced by operating speed, torque, stiffness, damping, inertia, and tooth profile. DANST performs geometric modeling and dynamic analysis for low- or high-contact-ratio spur gears. DANST can simulate gear systems with contact ratios ranging from one to three. It was designed to be easy to use and it is extensively documented in several previous reports and by comments in the source code. This report describes installing and using a new PC version of DANST, covers input data requirements and presents examples.

  19. Run-08 pC polarization analysis - October 16, 2008

    SciTech Connect

    Dharmawardane,V.; Bazilevsky,A.; Bunce, G.; Gill, R.; Huang, H.; Makdisi, Y.; Nakagawa, I.; Morozov, B.; Okada, H.; Sivertz, M.; Zelenski, A.; Alekseev, I.; Svirida, D.

    2009-03-01

    In this note we will discuss the analysis of RHIC run 08 pC data that were collected during February 14 - March 10, 2008. An analysis method that is similar to Run 05 and Run 06 was adopted for Run 08 analysis (except few minor changes, which are described below). A detailed analysis note and a NIM article that describe the pC analysis procedure (for run 05 and run 06) can be found elsewhere. In brief, the analysis consists of calibrating the detectors, determining energy corrections ('dead layers'), determining good runs and extracting the polarization from data.

  20. PC-Based Applications Programming on the SRS Control System.

    NASA Astrophysics Data System (ADS)

    Martlew, Brian; Owen, Hywel; Pugh, Martin; Rawlinson, Bill; Smith, Susan

    1997-05-01

    The CERN PC-based ISOLDE control system has been installed at the SRS electron storage ring at Daresbury Laboratory. The use of Windows NT for the control consoles together with PC and VME front-end computers running under several operating systems has resulted in a flexible and reliable system for accelerator control. The implementation and philosophy of control application programs, based around a suite of Microsoft Visual Basic and Excel programs, is described. In particular, the use of Excel to provide adaptable programs online allows rapid generation of new control functions; orbit correction and servoing at the application level are described as examples of this.

  1. Effect of morphine on PC12 cells with molecular radar

    NASA Astrophysics Data System (ADS)

    Shi, Chen; Yu, Xiaoli; Lu, Jiuyi; Zhang, Chunyang; Jin, Lei; Ma, Hui; Zhang, Dacheng; Chen, Die Yan

    2000-10-01

    Molecular Radar (MR) is a new method to detect biological processes in living cells at the level of molecular, it is also the newest means to get intracellular information. In this paper we study the effect of morphine on PC12 cells using MR. The results show that the effect of morphine on PC12 cells is time- and concentration-dependent. Morphine treating for short time induces the increase and fluctuation of intracellular (CA2+), while morphine treating for long time induces chromatin condensation, loss of mitochondria membrane potential apoptosis.

  2. PC Windows finite element modeling of landfill gas flow

    SciTech Connect

    Mull, S.R.; Lang, R.J.; Vigil, S.A.; Cota, H.

    1996-09-01

    A two dimensional demonstration program, GAS, has been developed for the solution of landfill gas (LFG) flow problems on a personal computer (PC). The program combines a Windows{trademark} graphical user interface, object oriented programming (OOP) techniques, and finite element modeling (FEM) to demonstrate the practicality of performing LFG flow modeling on the PC. GAS is demonstrated on a sample LFG problem consisting of a landfill, one gas extraction well, the landfill liner, cap, and surrounding soil. Analyses of the program results are performed for successively finer grid resolutions. Element flux imbalance, execution time, and required memory are characterized as a function of grid resolution.

  3. Wf/pc Cycle 1 Calibration: Internal Delta Flats

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1990-12-01

    This calibration takes internal flats periodically to permit the repair of external (earth-target) flat fields changed by pixel dependent QE changes which occur whenever the WF/PC is decontaminated. Note that the internal flat lamp is also useful with relatively wide filters in the red. This obtains intflats for: WFC: F439W, F547M, F555W, F622W, F702W, F785LP PC: F439W, F547M, F555W, F622W, F702W, F718M, F785LP

  4. Software Certification - Coding, Code, and Coders

    NASA Technical Reports Server (NTRS)

    Havelund, Klaus; Holzmann, Gerard J.

    2011-01-01

    We describe a certification approach for software development that has been adopted at our organization. JPL develops robotic spacecraft for the exploration of the solar system. The flight software that controls these spacecraft is considered to be mission critical. We argue that the goal of a software certification process cannot be the development of "perfect" software, i.e., software that can be formally proven to be correct under all imaginable and unimaginable circumstances. More realistically, the goal is to guarantee a software development process that is conducted by knowledgeable engineers, who follow generally accepted procedures to control known risks, while meeting agreed upon standards of workmanship. We target three specific issues that must be addressed in such a certification procedure: the coding process, the code that is developed, and the skills of the coders. The coding process is driven by standards (e.g., a coding standard) and tools. The code is mechanically checked against the standard with the help of state-of-the-art static source code analyzers. The coders, finally, are certified in on-site training courses that include formal exams.

  5. Immunocytochemical localization of prohormone convertases PC1 and PC2 in the anuran pituitary gland: subcellular localization in corticotrope and melanotrope cells.

    PubMed

    Kurabuchi, S; Tanaka, S

    1997-06-01

    Specific antisera against mammalian prohormone convertases PC1 and PC2 have been used to examine, light-immunocytochemically, the distribution of these enzymes in the pituitary gland of five different species of anuran amphibians (Rana catesbeiana, Bufo japonicus formosus, Xenopus laevis, Rana brevipoda porosa, and Buergeria japonica). A differential pattern of immunoreactivity of PC1 and PC2 was found among these species. Only PC1 was found in the corticotrope cells of the pars distalis in R. catesbeiana, B. japonicus formosus, and X. laevis. Only PC2 was observed in these cells in B. japonica, whereas both PC1 and PC2 were present in these cells in R. brevipoda porosa. PC2 immunoreactivity was always observed in melanotrope cells in the pars intermedia of all of the species, but it coexisted with PC1 immunoreactivity only in R. catesbeiana and X. laevis. The nerve fibers and terminals in the pars nervosa in all of the species were intensely immunopositive with both PC1 and PC2 antibodies. Immunoelectron microscopy on B. japonicus formosus and B. japonica, by means of double-labeling with gold particles of different sizes, revealed that almost all the adrenocorticotropin-positive secretory granules in the corticotrope cells and alpha-melanophore-stimulating-hormone-positive secretory granules in the melanotrope cells were also labeled with either PC1 or PC2 antibodies. This study suggests that PC1 and PC2 are involved in the intracellular proteolytic cleavage of proopiomelanocortin in amphibian pituitary glands, a situation similar to that proposed for mammals.

  6. XSOR codes users manual

    SciTech Connect

    Jow, Hong-Nian; Murfin, W.B.; Johnson, J.D.

    1993-11-01

    This report describes the source term estimation codes, XSORs. The codes are written for three pressurized water reactors (Surry, Sequoyah, and Zion) and two boiling water reactors (Peach Bottom and Grand Gulf). The ensemble of codes has been named ``XSOR``. The purpose of XSOR codes is to estimate the source terms which would be released to the atmosphere in severe accidents. A source term includes the release fractions of several radionuclide groups, the timing and duration of releases, the rates of energy release, and the elevation of releases. The codes have been developed by Sandia National Laboratories for the US Nuclear Regulatory Commission (NRC) in support of the NUREG-1150 program. The XSOR codes are fast running parametric codes and are used as surrogates for detailed mechanistic codes. The XSOR codes also provide the capability to explore the phenomena and their uncertainty which are not currently modeled by the mechanistic codes. The uncertainty distributions of input parameters may be used by an. XSOR code to estimate the uncertainty of source terms.

  7. User's guide to the Personal Computer Version of the Biogenic Emissions Inventory System (PC-BEIS). Final report, June 1989-December 1990

    SciTech Connect

    Pierce, T.

    1991-01-01

    The Personal Computer Version of the Biogenic Emissions Inventory System (PC-BEIS) has been developed to allow users to estimate hourly emissions of biogenic non-methane hydrocarbon emissions for any county in the contiguous United States. PC-BEIS has been compiled using Microsoft FORTRAN and tested on IBM-compatible personal computers. The source code was written in ANSI FORTRAN 77 and should be transportable to most other computers. Emission rates depend on land use, leaf biomass, and emission factors. PC-BEIS also includes adjustments due to temperature and sunlight. A simple leaf energy balance module is included to allow more refined calculations of leaf temperature and sunlight through forest canopies. The user's guide briefly describes the technical background, provides an overview of computer aspects, and shows an example test case.

  8. Processing and intracellular localization of rice stripe virus Pc2 protein in insect cells

    SciTech Connect

    Zhao, Shuling; Zhang, Gaozhan; Dai, Xuejuan; Hou, Yanling; Li, Min; Liang, Jiansheng; Liang, Changyong

    2012-08-01

    Rice stripe virus (RSV) belongs to the genus Tenuivirus and its genome consists of four single-stranded RNAs encoding seven proteins. Here, we have analyzed the processing and membrane association of Pc2 encoded by vcRNA2 in insect cells. The enhanced green fluorescent protein (eGFP) was fused to the Pc2 and used for the detection of Pc2 fusion proteins. The results showed that Pc2 was cleaved to produce two proteins named Pc2-N and Pc2-C. When expressed alone, either Pc2-N or Pc2-C could transport to the Endoplasmic reticulum (ER) membranes independently. Further mutagenesis studies revealed that Pc2 contained three ER-targeting domains. The results led us to propose a model for the topology of the Pc2 in which an internal signal peptide immediately followed a cleavage site, and two transmembrane regions are contained.

  9. DLLExternalCode

    SciTech Connect

    Greg Flach, Frank Smith

    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.

  10. Defeating the coding monsters.

    PubMed

    Colt, Ross

    2007-02-01

    Accuracy in coding is rapidly becoming a required skill for military health care providers. Clinic staffing, equipment purchase decisions, and even reimbursement will soon be based on the coding data that we provide. Learning the complicated myriad of rules to code accurately can seem overwhelming. However, the majority of clinic visits in a typical outpatient clinic generally fall into two major evaluation and management codes, 99213 and 99214. If health care providers can learn the rules required to code a 99214 visit, then this will provide a 90% solution that can enable them to accurately code the majority of their clinic visits. This article demonstrates a step-by-step method to code a 99214 visit, by viewing each of the three requirements as a monster to be defeated.

  11. Fabrication of high efficiency compact 90° bend waveguide by using a dielectric 2D-PC structure

    NASA Astrophysics Data System (ADS)

    Stomeo, Tiziana; Bergamo, Roberto; Martiradonna, Luigi; Cingolani, Roberto; De Vittorio, Massimo; D'Orazio, Antonella; Marrocco, Valeria

    2005-07-01

    In this paper we propose the design and the fabrication of 90° bend ridge waveguide (WG) assisted by a two-dimensional photonic crystal (2D-PC). 2D-PCs act as efficient mirrors along the boundaries of the bend ridge thus reducing the in-plane losses. The ridge waveguide consists of a 3 μm x 0.75 μm titanium dioxide core on a silica bottom cladding. The 2D-PC structure surrounding the bend waveguide is composed of a triangular array of circular dielectric pillars having a height of 0.75 μm. The titanium dioxide waveguiding core layer is covered with PMMA in order to create a quasi-symmetric structure. A photonic band gap centered around 1.3 μm is obtained by a PC radius r = 0.33a and lattice period a = 0.450 μm. The design of the whole structure is subsequently optimized by using a 3D Finite Difference Time Domain based computer code. The ridge waveguide assisted by a 2D-PC has been fabricated by using electron beam lithography and reactive ion etching. For the pattern transfer we have used about 50 nm thin layer Cr metal etch mask obtained by means of a lift-off technique based on the use of bi-layer resist (PMMA/MMA). The presence of the 2D-PC around the bend waveguide leads to a sharp increase of the transmission efficiency around 1.3 μm for curvature radius of 2.5 μm. The bend transmission results to be in the range between 0.76 and 0.85 when the thickness of the ridge WG and of the 2D-PC pillars is between 0.75 and 1.3 μm. This value is more than twice with respect to the bend waveguide without 2D-PC.

  12. NASA Lewis Steady-State Heat Pipe Code Architecture

    NASA Technical Reports Server (NTRS)

    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

  13. A code for calculating intrabeam scattering and beam lifetime

    SciTech Connect

    Kim, C.H.

    1997-05-01

    Beam emittances in a circular accelerator with a high beam intensity are strongly affected by the small angle intrabeam Coulomb scattering. In the computer simulation model the authors present here they used three coupled nonlinear differential equations to describe the evolution of the emittances in the transverse and the longitudinal planes. These equations include terms which take into account the intra-beam scattering, adiabatic damping, microwave instabilities, synchrotron damping, and quantum excitations. A code is generated to solve the equations numerically and incorporated into a FORTRAN code library. Circular high intensity physics routines are included in the library such as intrabeam scattering, Touschek scattering, and the bunch lengthening effect of higher harmonic cavities. The code runs presently in the PC environment. Description of the code and some examples are presented.

  14. Alkali metal ion catalysis and inhibition in nucleophilic displacement reactions at phosphorus centers: ethyl and methyl paraoxon and ethyl and methyl parathion.

    PubMed

    Um, Ik-Hwan; Shin, Young-Hee; Lee, Seung-Eun; Yang, Kiyull; Buncel, Erwin

    2008-02-01

    We report on the ethanolysis of the P=O and P=S compounds ethyl and methyl paraoxon (1a and 1b) and ethyl and methyl parathion (2a and 2b). Plots of spectrophotometrically measured rate constants, kobsd versus [MOEt], the alkali ethoxide concentration, show distinct upward and downward curvatures, pointing to the importance of ion-pairing phenomena and a differential reactivity of free ions and ion pairs. Three types of reactivity and selectivity patterns have been discerned: (1) For the P=O compounds 1a and 1b, LiOEt > NaOEt > KOEt > EtO-; (2) for the P=S compound 2a, KOEt > EtO- > NaOEt > LiOEt; (3) for P=S, 2b, 18C6-crown-complexed KOEt > KOEt = EtO(-) > NaOEt > LiOEt. These selectivity patterns are characteristic of both catalysis and inhibition by alkali-metal cations depending on the nature of the electrophilic center, P=O vs P=S, and the metal cation. Ground-state (GS) vs transition-state (TS) stabilization energies shed light on the catalytic and inhibitory tendencies. The unprecedented catalytic behavior of crowned-K(+) for the reaction of 2b is noteworthy. Modeling reveals an extreme steric interaction for the reaction of 2a with crowned-K(+), which is responsible for the absence of catalysis in this system. Overall, P=O exhibits greater reactivity than P=S, increasing from 50- to 60-fold with free EtO(-) and up to 2000-fold with LiOEt, reflecting an intrinsic P=O vs P=S reactivity difference (thio effect). The origin of reactivity and selectivity differences in these systems is discussed on the basis of competing electrostatic effects and solvational requirements as function of anionic electric field strength and cation size (Eisenman's theory).

  15. PC Board Layout and Electronic Drafting with CAD. Teacher Edition.

    ERIC Educational Resources Information Center

    Bryson, Jimmy

    This teacher's guide contains 11 units of instruction for a course on computer electronics and computer-assisted drafting (CAD) using a personal computer (PC). The course covers the following topics: introduction to electronic drafting with CAD; CAD system and software; basic electronic theory; component identification; basic integrated circuit…

  16. Audio Podcasting in a Tablet PC-Enhanced Biochemistry Course

    ERIC Educational Resources Information Center

    Lyles, Heather; Robertson, Brian; Mangino, Michael; Cox, James R.

    2007-01-01

    This report describes the effects of making audio podcasts of all lectures in a large, basic biochemistry course promptly available to students. The audio podcasts complement a previously described approach in which a tablet PC is used to annotate PowerPoint slides with digital ink to produce electronic notes that can be archived. The fundamentals…

  17. Using a PC as a Frequency Meter or a Counter.

    ERIC Educational Resources Information Center

    Sartori, J.; And Others

    1995-01-01

    Describes hardware that enables the use of an IBM PC microcomputer as a frequency meter or a counter by using the parallel printer port. Eliminates the 16-bit time-day counter through the use of an external time base that can be conveniently set depending on the desired frequency range. (JRH)

  18. Teaching Mathematics in the PC Lab--The Students' Viewpoints

    ERIC Educational Resources Information Center

    Schmidt, Karsten; Kohler, Anke

    2013-01-01

    The Matrix Algebra portion of the intermediate mathematics course at the Schmalkalden University Faculty of Business and Economics has been moved from a traditional classroom setting to a technology-based setting in the PC lab. A Computer Algebra System license was acquired that also allows its use on the students' own PCs. A survey was carried…

  19. A PC-based Workstation for Robotic Discectomy

    NASA Technical Reports Server (NTRS)

    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.

  20. An Apple for Your IBM PC--The Quadlink Board.

    ERIC Educational Resources Information Center

    Owen, G. Scott

    1984-01-01

    Describes nature and installation of the QUADLINK board which allows Apple software to be run on IBM PC microcomputers. Although programs tested ran without problems, users should test their own programs since there are some copy protection schemes that can baffle the board. (JN)

  1. What's Under Your PC's 'Hood': A Primer for Today's Machines.

    ERIC Educational Resources Information Center

    Chen, Li; Mills, Joyce White

    2002-01-01

    Explains how to decide what type of computer to buy for a small academic library, based on software requirements, staff and patron use, and PC technology. Topics include the central processing unit; types of memory; storage devices; ports; multimedia capabilities; modems; operating systems; and monitors. (LRW)

  2. Electronic States of IC60BA and PC71BM

    NASA Astrophysics Data System (ADS)

    Sheng, Chun-Qi; Wang, Peng; Shen, Ying; Li, Wen-Jie; Zhang, Wen-Hua; Zhu, Jun-Fa; Lai, Guo-Qiao; Li, Hong-Nian

    2013-11-01

    We investigate the electronic states of IC60BA and PC71BM using first-principles calculations and photoelectron spectroscopy (PES) measurements. The energy level structures for all possible isomers are reported and compared with those of C60, C70 and PC61BM. The attachment of the side chains can raise the LUMO energies and decrease the HOMO-LUMO gaps, and thus helps to increase the power-conversion efficiency of bulk heterojunction solar cells. In the PES studies, we prepared IC60BA and PC71BM films on Si:H(111) substrates to construct adsorbate/substrate interfaces describable with the integer charge-transfer (ICT) model. Successful measurements then revealed that one of the most important material properties for an electron acceptor, the energy of the negative integer charge-transfer state (EICT-), is 4.31 eV below the vacuum level for PC71BM. The EICT- of IC60BA is smaller than 4.14 eV.

  3. Wf/pc Cycle 2 Calib: Single Chip UV Calibration

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1991-07-01

    THIS PROGRAM CALIBRATES THE QE OF THE WFC AND PC IN THE ULTRAVIOLET (F194W, F230W, AND F284W). This calibration is done using exposures of a UV flux standard star. This program is intended for use only following a UV decontamination.

  4. Wf/pc Cycle 1 Calib: 4-CHIP UV Calibration

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1990-12-01

    THIS PROGRAM CALIBRATES THE QE OF THE WFC AND PC IN THE ULTRAVIOLET (F194W, F230W, AND F284W). This calibration is done for each CCD detector using exposures of a UV flux standard star. This program is intended for use only during a UV campaign.

  5. 39 CFR 501.16 - PC postage payment methodology.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... examination of its PC Postage system and any other applications and technology infrastructure that may have a... organization uses another service organization (sub-service provider), Postal Service Management should... contribution of the sub-service organization's processes and controls in the achievement of the Postal...

  6. 39 CFR 501.16 - PC postage payment methodology.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... examination of its PC Postage system and any other applications and technology infrastructure that may have a... organization uses another service organization (sub-service provider), Postal Service Management should... contribution of the sub-service organization's processes and controls in the achievement of the Postal...

  7. 39 CFR 501.16 - PC postage payment methodology.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... examination of its PC Postage system and any other applications and technology infrastructure that may have a... uses another service organization (sub-service provider), Postal Service management should consider the... of the sub-service organization's processes and controls in the achievement of the Postal...

  8. Multi-Purpose, Multi-Reservoir Simulation on a PC

    DTIC Science & Technology

    1988-08-01

    The methodology and difficulties in converting a large, general purpose, mainframe, batch oriented computer program (for reservoir simulation ) to...work effectively in the PC environment are described in this paper. A brief overview of the present capabilities of the general purpose reservoir ... simulation program (HEC-5), that works on mainframe and MS DOS compatible computers, is also presented. Keywords: Simulation, Personal computer, Reservior

  9. PC-CUBE: A Personal Computer Based Hypercube

    NASA Technical Reports Server (NTRS)

    Ho, Alex; Fox, Geoffrey; Walker, David; Snyder, Scott; Chang, Douglas; Chen, Stanley; Breaden, Matt; Cole, Terry

    1988-01-01

    PC-CUBE is an ensemble of IBM PCs or close compatibles connected in the hypercube topology with ordinary computer cables. Communication occurs at the rate of 115.2 K-band via the RS-232 serial links. Available for PC-CUBE is the Crystalline Operating System III (CrOS III), Mercury Operating System, CUBIX and PLOTIX which are parallel I/O and graphics libraries. A CrOS performance monitor was developed to facilitate the measurement of communication and computation time of a program and their effects on performance. Also available are CXLISP, a parallel version of the XLISP interpreter; GRAFIX, some graphics routines for the EGA and CGA; and a general execution profiler for determining execution time spent by program subroutines. PC-CUBE provides a programming environment similar to all hypercube systems running CrOS III, Mercury and CUBIX. In addition, every node (personal computer) has its own graphics display monitor and storage devices. These allow data to be displayed or stored at every processor, which has much instructional value and enables easier debugging of applications. Some application programs which are taken from the book Solving Problems on Concurrent Processors (Fox 88) were implemented with graphics enhancement on PC-CUBE. The applications range from solving the Mandelbrot set, Laplace equation, wave equation, long range force interaction, to WaTor, an ecological simulation.

  10. Wf/pc Cycle 1 CALIBRATION:UV Flats 1

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1990-12-01

    This program takes "uniform illuminated" pictures of the earth to obtain the "instrument signature" for flat field corrections for the UV filters. The camera - filter combinations done in this proposal are: WFC: F194W, F230W, F284W PC: F194W, F230W, F284W This calibration should be part of each UV campaign.

  11. Deciding when It's Time to Buy a New PC

    ERIC Educational Resources Information Center

    Goldsborough, Reid

    2004-01-01

    How to best decide when it's time to replace your PC, whether at home or at work, is always tricky. Spending on computers can make you more productive, but it's money you otherwise cannot spend, invest or save, and faster systems always await you in the future. What is clear is that the computer industry really wants you to buy, and the computer…

  12. 36. View of preset counter (PC) console and tracking console ...

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

    36. View of preset counter (PC) console and tracking console on right, located in MWOC facility in transmitter building no. 102. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  13. PC vs. Mac--Which Way Should You Go?

    ERIC Educational Resources Information Center

    Wodarz, Nan

    1997-01-01

    Outlines the factors in hardware, software, and administration to consider in developing specifications for choosing a computer operating system. Compares Microsoft Windows 95/NT that runs on PC/Intel-based systems and System 7.5 that runs on the Apple-based systems. Lists reasons why the Microsoft platform clearly stands above the Apple platform.…

  14. Privacy Impact Assessment for the PC Label System

    EPA Pesticide Factsheets

    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

  15. LERC-SLAM - THE NASA LEWIS RESEARCH CENTER SATELLITE LINK ATTENUATION MODEL PROGRAM (IBM PC VERSION)

    NASA Technical Reports Server (NTRS)

    Manning, R. M.

    1994-01-01

    antenna required to establish a link with the satellite, the statistical parameters that characterize the rainrate process at the terminal site, the length of the propagation path within the potential rain region, and its projected length onto the local horizontal. The IBM PC version of LeRC-SLAM (LEW-14979) is written in Microsoft QuickBASIC for an IBM PC compatible computer with a monitor and printer capable of supporting an 80-column format. The IBM PC version is available on a 5.25 inch MS-DOS format diskette. The program requires about 30K RAM. The source code and executable are included. The Macintosh version of LeRC-SLAM (LEW-14977) is written in Microsoft Basic, Binary (b) v2.00 for Macintosh II series computers running MacOS. This version requires 400K RAM and is available on a 3.5 inch 800K Macintosh format diskette, which includes source code only. The Macintosh version was developed in 1987 and the IBM PC version was developed in 1989. IBM PC is a trademark of International Business Machines. MS-DOS is a registered trademark of Microsoft Corporation. Macintosh is a registered trademark of Apple Computer, Inc.

  16. Induction of cytoprotective autophagy in PC-12 cells by cadmium

    SciTech Connect

    Wang, Qiwen; Zhu, Jiaqiao; Zhang, Kangbao; Jiang, Chenyang; Wang, Yi; Yuan, Yan; Bian, Jianchun; Liu, Xuezhong; Gu, Jianhong; Liu, Zongping

    2013-08-16

    Highlights: •Cadmium can promote early upregulation of autophagy in PC-12 cells. •Autophagy precedes apoptosis in cadmium-treated PC-12 cells. •Cadmium-induced autophagy is cytoprotective in PC-12 cells. •Class III PI3K/beclin-1/Bcl-2 signaling pathway plays a positive role in cadmium-triggered autophagy. -- Abstract: Laboratory data have demonstrated that cadmium (Cd) may induce neuronal apoptosis. However, little is known about the role of autophagy in neurons. In this study, cell viability decreased in a dose- and time-dependent manner after treatment with Cd in PC-12 cells. As cells were exposed to Cd, the levels of LC3-II proteins became elevated, specific punctate distribution of endogenous LC3-II increased, and numerous autophagosomes appeared, which suggest that Cd induced a high level of autophagy. In the late stages of autophagy, an increase in the apoptosis ratio was observed. Likewise, pre-treatment with chloroquine (an autophagic inhibitor) and rapamycin (an autophagic inducer) resulted in an increased and decreased percentage of apoptosis in contrast to other Cd-treated groups, respectively. The results indicate that autophagy delayed apoptosis in Cd-treated PC-12 cells. Furthermore, co-treatment of cells with chloroquine reduced autophagy and cell activity. However, rapamycin had an opposite effect on autophagy and cell activity. Moreover, class III PI3 K/beclin-1/Bcl-2 signaling pathways served a function in Cd-induced autophagy. The findings suggest that Cd can induce cytoprotective autophagy by activating class III PI3 K/beclin-1/Bcl-2 signaling pathways. In sum, this study strongly suggests that autophagy may serve a positive function in the reduction of Cd-induced cytotoxicity.

  17. IPEG- IMPROVED PRICE ESTIMATION GUIDELINES (IBM PC VERSION)

    NASA Technical Reports Server (NTRS)

    Aster, R. W.

    1994-01-01

    The Improved Price Estimation Guidelines, IPEG, program provides a simple yet accurate estimate of the price of a manufactured product. IPEG facilitates sensitivity studies of price estimates at considerably less expense than would be incurred by using the Standard Assembly-line Manufacturing Industry Simulation, SAMIS, program (COSMIC program NPO-16032). A difference of less than one percent between the IPEG and SAMIS price estimates has been observed with realistic test cases. However, the IPEG simplification of SAMIS allows the analyst with limited time and computing resources to perform a greater number of sensitivity studies than with SAMIS. Although IPEG was developed for the photovoltaics industry, it is readily adaptable to any standard assembly line type of manufacturing industry. IPEG estimates the annual production price per unit. The input data includes cost of equipment, space, labor, materials, supplies, and utilities. Production on an industry wide basis or a process wide basis can be simulated. Once the IPEG input file is prepared, the original price is estimated and sensitivity studies may be performed. The IPEG user selects a sensitivity variable and a set of values. IPEG will compute a price estimate and a variety of other cost parameters for every specified value of the sensitivity variable. IPEG is designed as an interactive system and prompts the user for all required information and offers a variety of output options. The IPEG/PC program is written in TURBO PASCAL for interactive execution on an IBM PC computer under DOS 2.0 or above with at least 64K of memory. The IBM PC color display and color graphics adapter are needed to use the plotting capabilities in IPEG/PC. IPEG/PC was developed in 1984. The original IPEG program is written in SIMSCRIPT II.5 for interactive execution and has been implemented on an IBM 370 series computer with a central memory requirement of approximately 300K of 8 bit bytes. The original IPEG was developed in 1980.

  18. CLIPS - C LANGUAGE INTEGRATED PRODUCTION SYSTEM (IBM PC VERSION WITH CLIPSITS)

    NASA Technical Reports Server (NTRS)

    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

  19. Mechanical code comparator

    DOEpatents

    Peter, Frank J.; Dalton, Larry J.; Plummer, David W.

    2002-01-01

    A new class of mechanical code comparators is described which have broad potential for application in safety, surety, and security applications. These devices can be implemented as micro-scale electromechanical systems that isolate a secure or otherwise controlled device until an access code is entered. This access code is converted into a series of mechanical inputs to the mechanical code comparator, which compares the access code to a pre-input combination, entered previously into the mechanical code comparator by an operator at the system security control point. These devices provide extremely high levels of robust security. Being totally mechanical in operation, an access control system properly based on such devices cannot be circumvented by software attack alone.

  20. More box codes

    NASA Technical Reports Server (NTRS)

    Solomon, G.

    1992-01-01

    A new investigation shows that, starting from the BCH (21,15;3) code represented as a 7 x 3 matrix and adding a row and column to add even parity, one obtains an 8 x 4 matrix (32,15;8) code. An additional dimension is obtained by specifying odd parity on the rows and even parity on the columns, i.e., adjoining to the 8 x 4 matrix, the matrix, which is zero except for the fourth column (of all ones). Furthermore, any seven rows and three columns will form the BCH (21,15;3) code. This box code has the same weight structure as the quadratic residue and BCH codes of the same dimensions. Whether there exists an algebraic isomorphism to either code is as yet unknown.

  1. Surface-type nonvolatile electric memory elements based on organic-on-organic CuPc-H2Pc heterojunction

    NASA Astrophysics Data System (ADS)

    Khasan, S. Karimov; Zubair, Ahmad; Farid, Touati; Mahroof-Tahir, M.; M. Muqeet, Rehman; S. Zameer, Abbas

    2015-11-01

    A novel surface-type nonvolatile electric memory elements based on organic semiconductors CuPc and H2Pc are fabricated by vacuum deposition of the CuPc and H2Pc films on preliminary deposited metallic (Ag and Cu) electrodes. The gap between Ag and Cu electrodes is 30-40 μm. For the current-voltage (I-V) characteristics the memory effect, switching effect, and negative differential resistance regions are observed. The switching mechanism is attributed to the electric-field-induced charge transfer. As a result the device switches from a low to a high-conductivity state and then back to a low conductivity state if the opposite polarity voltage is applied. The ratio of resistance at the high resistance state to that at the low resistance state is equal to 120-150. Under the switching condition, the electric current increases ˜ 80-100 times. A comparison between the forward and reverse I-V characteristics shows the presence of rectifying behavior. Project supported by the GIK Institute of Engineering Science and Technology, Pakistan and Physical Technical Institute of Academy of Sciences of Tajikistan.

  2. Chromosomal assignment of the genes for proprotein convertases PC4, PC5, and PACE 4 in mouse and human.

    PubMed

    Mbikay, M; Seidah, N G; Chrétien, M; Simpson, E M

    1995-03-01

    The genes for three subtilisin/kexin-like proprotein convertases, PC4, PC5, and PACE4, were mapped in the mouse by RFLP analysis of a DNA panel from a (C57BL/6JEi x SPRET/Ei)F1 x SPRET/Ei backcross. The chromosomal locations of the human homologs were determined by Southern blot analysis of a DNA panel from human-rodent somatic cell hybrids, most of which contained a single human chromosome each. The gene for PC4 (Pcsk4 locus) mapped to mouse chromosome 10, close to the Adn (adipsin, a serine protease) locus and near the Amh (anti-müllerian hormone) locus; in human, the gene was localized to chromosome 19. The gene for PC5 (Pcsk5 locus) mapped to mouse chromosome 19 close to the Lpc1 (lipocortin-1) locus and, in human, was localized to chromosome 9. The gene for PACE4 (Pcsk6 locus) mapped to mouse chromosome 7, at a distance of 13 cM from the Pcsk3 locus, which specifies furin, another member of this family of enzymes previously mapped to this chromosome. This is in concordance with the known close proximity of these two loci in the homologous region on human chromosome 15q25-qter. Pcsk3 and Pcsk6 mapped to a region of mouse chromosome 7 that has been associated cytogenetically with postnatal lethality in maternal disomy, suggesting that these genes might be candidates for imprinting.

  3. Generating code adapted for interlinking legacy scalar code and extended vector code

    DOEpatents

    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.

  4. Industrial Computer Codes

    NASA Technical Reports Server (NTRS)

    Shapiro, Wilbur

    1996-01-01

    This is an overview of new and updated industrial codes for seal design and testing. GCYLT (gas cylindrical seals -- turbulent), SPIRALI (spiral-groove seals -- incompressible), KTK (knife to knife) Labyrinth Seal Code, and DYSEAL (dynamic seal analysis) are covered. CGYLT uses G-factors for Poiseuille and Couette turbulence coefficients. SPIRALI is updated to include turbulence and inertia, but maintains the narrow groove theory. KTK labyrinth seal code handles straight or stepped seals. And DYSEAL provides dynamics for the seal geometry.

  5. Phonological coding during reading

    PubMed Central

    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

  6. CARES/PC - CERAMICS ANALYSIS AND RELIABILITY EVALUATION OF STRUCTURES

    NASA Technical Reports Server (NTRS)

    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

  7. METHANE de-NOX for Utility PC Boilers

    SciTech Connect

    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

  8. Tokamak Systems Code

    SciTech Connect

    Reid, R.L.; Barrett, R.J.; Brown, T.G.; Gorker, G.E.; Hooper, R.J.; Kalsi, S.S.; Metzler, D.H.; Peng, Y.K.M.; Roth, K.E.; Spampinato, P.T.

    1985-03-01

    The FEDC Tokamak Systems Code calculates tokamak performance, cost, and configuration as a function of plasma engineering parameters. This version of the code models experimental tokamaks. It does not currently consider tokamak configurations that generate electrical power or incorporate breeding blankets. The code has a modular (or subroutine) structure to allow independent modeling for each major tokamak component or system. A primary benefit of modularization is that a component module may be updated without disturbing the remainder of the systems code as long as the imput to or output from the module remains unchanged.

  9. Topological subsystem codes

    SciTech Connect

    Bombin, H.

    2010-03-15

    We introduce a family of two-dimensional (2D) topological subsystem quantum error-correcting codes. The gauge group is generated by two-local Pauli operators, so that two-local measurements are enough to recover the error syndrome. We study the computational power of code deformation in these codes and show that boundaries cannot be introduced in the usual way. In addition, we give a general mapping connecting suitable classical statistical mechanical models to optimal error correction in subsystem stabilizer codes that suffer from depolarizing noise.

  10. FAA Smoke Transport Code

    SciTech Connect

    Domino, Stefan; Luketa-Hanlin, Anay; Gallegos, Carlos

    2006-10-27

    FAA Smoke Transport Code, a physics-based Computational Fluid Dynamics tool, which couples heat, mass, and momentum transfer, has been developed to provide information on smoke transport in cargo compartments with various geometries and flight conditions. The software package contains a graphical user interface for specification of geometry and boundary conditions, analysis module for solving the governing equations, and a post-processing tool. The current code was produced by making substantial improvements and additions to a code obtained from a university. The original code was able to compute steady, uniform, isothermal turbulent pressurization. In addition, a preprocessor and postprocessor were added to arrive at the current software package.

  11. Transonic airfoil codes

    NASA Technical Reports Server (NTRS)

    Garabedian, P. R.

    1979-01-01

    Computer codes for the design and analysis of transonic airfoils are considered. The design code relies on the method of complex characteristics in the hodograph plane to construct shockless airfoil. The analysis code uses artificial viscosity to calculate flows with weak shock waves at off-design conditions. Comparisons with experiments show that an excellent simulation of two dimensional wind tunnel tests is obtained. The codes have been widely adopted by the aircraft industry as a tool for the development of supercritical wing technology.

  12. Thionate versus Oxon: comparison of stability, uptake, and cell toxicity of ((14)CH(3)O)(2)-labeled methyl parathion and methyl paraoxon with SH-SY5Y cells.

    PubMed

    Bharate, Sandip B; Prins, John M; George, Kathleen M; Thompson, Charles M

    2010-07-28

    The stability, hydrolysis, and uptake of the organophosphates methyl parathion and methyl paraoxon were investigated in SH-SY5Y cells. The stabilities of ((14)CH(3)O)(2)-methyl parathion ((14)C-MPS) and ((14)CH(3)O)(2)-methyl paraoxon ((14)C-MPO) at 1 microM in culture media had similar half-lives of 91.7 and 101.9 h, respectively. However, 100 microM MPO caused >95% cytotoxicity at 24 h, whereas 100 microM MPS caused 4-5% cytotoxicity at 24 h ( approximately 60% cytotoxicity at 48 h). Greater radioactivity was detected inside cells treated with MPO as compared to MPS, although >80% of the total MPO uptake was primarily dimethyl phosphate (DMP). Maximum uptake was reached after 48 h of (14)C-MPS or (14)C-MPO exposure with total uptakes of 1.19 and 1.76 nM/10(6) cells for MPS and MPO, respectively. The amounts of MPS and MPO detected in the cytosol after 48 h of exposure time were 0.54 and 0.37 nM/10(6) cells, respectively.

  13. The secretory proprotein convertases furin, PC5, and PC7 activate VEGF-C to induce tumorigenesis

    PubMed Central

    Siegfried, Geraldine; Basak, Ajoy; Cromlish, James A.; Benjannet, Suzanne; Marcinkiewicz, Jadwiga; Chrétien, Michel; Seidah, Nabil G.; Khatib, Abdel-Majid

    2003-01-01

    The secretory factor VEGF-C has been directly implicated in various physiological processes during embryogenesis and human cancers. However, the importance of the conversion of its precursor proVEGF-C to mature VEGF-C in tumorigenesis, and vessel formation and the identity of the protease(s) that regulate these processes is/are not known. The intracellular processing of proVEGF-C that occurs within the dibasic motif HSIIRR227SL suggests the involvement of the proprotein convertases (PCs) in this process. In addition, furin and VEGF-C were found to be coordinately expressed in adult mouse tissues. Cotransfection of the furin-deficient colon carcinoma cell line LoVo with proVEGF-C and different PC members revealed that furin, PC5, and PC7 are candidate VEGF-C convertases. This finding is consistent with the in vitro digestions of an internally quenched synthetic fluorogenic peptide mimicking the cleavage site of proVEGF-C (220Q-VHSIIRR↓SLP230). The processing of proVEGF-C is blocked by the inhibitory prosegments of furin, PC5, and PACE4, as well as by furin-motif variants of α2-macroglobulin and α1-antitrypsin. Subcutaneous injection of CHO cells stably expressing VEGF-C into nude mice enhanced angiogenesis and lymphangiogenesis, but not tumor growth. In contrast, expression of proVEGF-C obtained following mutation of the cleavage site (HSIIRR227SL to HSIISS227SL) inhibits angiogenesis and lymphangiogenesis as well as tumor growth. Our findings demonstrate the processing of proVEGF-C by PCs and highlight the potential use of PC inhibitors as agents for inhibiting malignancies induced by VEGF-C. PMID:12782675

  14. Establishment and characterization of methylmercury-resistant PC12 cell line.

    PubMed Central

    Miura, K; Clarkson, T W; Ikeda, K; Naganuma, A; Imura, N

    1994-01-01

    Methylmercury (MeHg)-resistant sublines of rat pheochromocytoma (PC12) cells were isolated by repeated exposure to stepwise increased concentrations of MeHg. One of the sublines (PC12/TM) showed an 8- to 10-fold increase in resistance to MeHg compared with parent PC12 cells on the basis of the concentration required for 50% inhibition (IC50) of growth. PC12/TM cells accumulated smaller amounts of MeHg than parent PC12 cells. This reduction in MeHg accumulation in PC12/TM cells resulted from slow uptake and rapid efflux. The intracellular glutathione (GSH) level in PC12/TM cells was four times higher than that of PC12 cells. Pretreatment of PC12/TM cells with buthionine sulfoximine, which decreased the GSH level to that of the parent PC12 cells, increased the sensitivity of PC12/TM cells to MeHg. A close correlation between the MeHg accumulation and MeHg sensitivity was found among seven sublines of PC12 cells and parent PC12 cell line. The GSH level in PC12 sublines was also correlated with their sensitivity to MeHg. PMID:7843125

  15. CLIPS 6.0 - C LANGUAGE INTEGRATED PRODUCTION SYSTEM, VERSION 6.0 (IBM PC VERSION)

    NASA Technical Reports Server (NTRS)

    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

  16. Calculation of Weibull strength parameters, Batdorf flaw density constants and related statistical quantities using PC-CARES

    NASA Technical Reports Server (NTRS)

    Szatmary, Steven A.; Gyekenyesi, John P.; Nemeth, Noel N.

    1990-01-01

    This manual describes the operation and theory of the PC-CARES (Personal Computer-Ceramic Analysis and Reliability Evaluation of Structures) computer program for the IBM PC and compatibles running PC-DOS/MS-DOR OR IBM/MS-OS/2 (version 1.1 or higher) operating systems. The primary purpose of this code is to estimate Weibull material strength parameters, the Batdorf crack density coefficient, and other related statistical quantities. Included in the manual is the description of the calculation of shape and scale parameters of the two-parameter Weibull distribution using the least-squares analysis and maximum likelihood methods for volume- and surface-flaw-induced fracture in ceramics with complete and censored samples. The methods for detecting outliers and for calculating the Kolmogorov-Smirnov and the Anderson-Darling goodness-of-fit statistics and 90 percent confidence bands about the Weibull line, as well as the techniques for calculating the Batdorf flaw-density constants are also described.

  17. The use of synthetic oligonucleotides with universal templates for rapid DNA sequencing: results with staphylococcal replicon pC221.

    PubMed

    Brenner, D G; Shaw, W V

    1985-02-01

    A rapid sequencing strategy has been devised and applied to determine the complete nucleotide sequence (4555 bp) of Staphylococcus aureus plasmid pC221. The entire replicon was cloned into phage M13mp8 in both orientations to provide 'universal templates' for primed DNA synthesis from internally-sited oligonucleotide primers. The latter were synthesized by a modification of a recently described paper disc method which employs phosphotriester chemistry. Less than 4 weeks was required for the synthesis of the required primers and for the sequencing experiments. Plasmid pC221 bears a substrate-inducible chloramphenicol acetyltransferase (CAT) gene that shares much homology with its counterparts in pC194 (S. aureus) and the chromosomal cat-86 gene of Bacillus pumilus, both in coding regions and upstream sequences believed to be involved in the induction phenomenon. A second plasmid-specified protein, REP D, has an 81% identity in the REP C polypeptide that has been shown to be essential for the replication of staphylococcal plasmid pT181. The 5' flanking region of rep D shows striking similarities with its counterpart in rep C that determines copy number and incompatibility. The nucleotide sequence reveals two additional and overlapping open reading frames that may specify proteins that play roles in plasmid relaxation and transfer.

  18. MMap: Fast Billion-Scale Graph Computation on a PC via Memory Mapping

    PubMed Central

    Lin, Zhiyuan; Kahng, Minsuk; Sabrin, Kaeser Md.; Chau, Duen Horng (Polo); Lee, Ho; Kang, U

    2015-01-01

    Graph computation approaches such as GraphChi and TurboGraph recently demonstrated that a single PC can perform efficient computation on billion-node graphs. To achieve high speed and scalability, they often need sophisticated data structures and memory management strategies. We propose a minimalist approach that forgoes such requirements, by leveraging the fundamental memory mapping (MMap) capability found on operating systems. We contribute: (1) a new insight that MMap is a viable technique for creating fast and scalable graph algorithms that surpasses some of the best techniques; (2) the design and implementation of popular graph algorithms for billion-scale graphs with little code, thanks to memory mapping; (3) extensive experiments on real graphs, including the 6.6 billion edge YahooWeb graph, and show that this new approach is significantly faster or comparable to the highly-optimized methods (e.g., 9.5× faster than GraphChi for computing PageRank on 1.47B edge Twitter graph). We believe our work provides a new direction in the design and development of scalable algorithms. Our packaged code is available at http://poloclub.gatech.edu/mmap/. PMID:25866846

  19. The laser linewidth effect on the image quality of phase coded synthetic aperture ladar

    NASA Astrophysics Data System (ADS)

    Cai, Guangyu; Hou, Peipei; Ma, Xiaoping; Sun, Jianfeng; Zhang, Ning; Li, Guangyuan; Zhang, Guo; Liu, Liren

    2015-12-01

    The phase coded (PC) waveform in synthetic aperture ladar (SAL) outperforms linear frequency modulated (LFM) signal in lower side lobe, shorter pulse duration and making the rigid control of the chirp starting point in every pulse unnecessary. Inherited from radar PC waveform and strip map SAL, the backscattered signal of a point target in PC SAL was listed and the two dimensional match filtering algorithm was introduced to focus a point image. As an inherent property of laser, linewidth is always detrimental to coherent ladar imaging. With the widely adopted laser linewidth model, the effect of laser linewidth on SAL image quality was theoretically analyzed and examined via Monte Carlo simulation. The research gives us a clear view of how to select linewidth parameters in the future PC SAL systems.

  20. Code to generate random identifiers and select QA/QC samples

    USGS Publications Warehouse

    Mehnert, Edward

    1992-01-01

    SAMPLID is a PC-based, FORTRAN-77 code which generates unique numbers for identification of samples, selection of QA/QC samples, and generation of labels. These procedures are tedious, but using a computer code such as SAMPLID can increase efficiency and reduce or eliminate errors and bias. The algorithm, used in SAMPLID, for generation of pseudorandom numbers is free of statistical flaws present in commonly available algorithms.

  1. New developments in the Saphire computer codes

    SciTech Connect

    Russell, K.D.; Wood, S.T.; Kvarfordt, K.J.

    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.

  2. Fast Coding Unit Encoding Mechanism for Low Complexity Video Coding

    PubMed Central

    Wu, Yueying; Jia, Kebin; Gao, Guandong

    2016-01-01

    In high efficiency video coding (HEVC), coding tree contributes to excellent compression performance. However, coding tree brings extremely high computational complexity. Innovative works for improving coding tree to further reduce encoding time are stated in this paper. A novel low complexity coding tree mechanism is proposed for HEVC fast coding unit (CU) encoding. Firstly, this paper makes an in-depth study of the relationship among CU distribution, quantization parameter (QP) and content change (CC). Secondly, a CU coding tree probability model is proposed for modeling and predicting CU distribution. Eventually, a CU coding tree probability update is proposed, aiming to address probabilistic model distortion problems caused by CC. Experimental results show that the proposed low complexity CU coding tree mechanism significantly reduces encoding time by 27% for lossy coding and 42% for visually lossless coding and lossless coding. The proposed low complexity CU coding tree mechanism devotes to improving coding performance under various application conditions. PMID:26999741

  3. Fast Coding Unit Encoding Mechanism for Low Complexity Video Coding.

    PubMed

    Gao, Yuan; Liu, Pengyu; Wu, Yueying; Jia, Kebin; Gao, Guandong

    2016-01-01

    In high efficiency video coding (HEVC), coding tree contributes to excellent compression performance. However, coding tree brings extremely high computational complexity. Innovative works for improving coding tree to further reduce encoding time are stated in this paper. A novel low complexity coding tree mechanism is proposed for HEVC fast coding unit (CU) encoding. Firstly, this paper makes an in-depth study of the relationship among CU distribution, quantization parameter (QP) and content change (CC). Secondly, a CU coding tree probability model is proposed for modeling and predicting CU distribution. Eventually, a CU coding tree probability update is proposed, aiming to address probabilistic model distortion problems caused by CC. Experimental results show that the proposed low complexity CU coding tree mechanism significantly reduces encoding time by 27% for lossy coding and 42% for visually lossless coding and lossless coding. The proposed low complexity CU coding tree mechanism devotes to improving coding performance under various application conditions.

  4. Dress Codes for Teachers?

    ERIC Educational Resources Information Center

    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…

  5. Legacy Code Modernization

    NASA Technical Reports Server (NTRS)

    Hribar, Michelle R.; Frumkin, Michael; Jin, Haoqiang; Waheed, Abdul; Yan, Jerry; Saini, Subhash (Technical Monitor)

    1998-01-01

    Over the past decade, high performance computing has evolved rapidly; systems based on commodity microprocessors have been introduced in quick succession from at least seven vendors/families. Porting codes to every new architecture is a difficult problem; in particular, here at NASA, there are many large CFD applications that are very costly to port to new machines by hand. The LCM ("Legacy Code Modernization") Project is the development of an integrated parallelization environment (IPE) which performs the automated mapping of legacy CFD (Fortran) applications to state-of-the-art high performance computers. While most projects to port codes focus on the parallelization of the code, we consider porting to be an iterative process consisting of several steps: 1) code cleanup, 2) serial optimization,3) parallelization, 4) performance monitoring and visualization, 5) intelligent tools for automated tuning using performance prediction and 6) machine specific optimization. The approach for building this parallelization environment is to build the components for each of the steps simultaneously and then integrate them together. The demonstration will exhibit our latest research in building this environment: 1. Parallelizing tools and compiler evaluation. 2. Code cleanup and serial optimization using automated scripts 3. Development of a code generator for performance prediction 4. Automated partitioning 5. Automated insertion of directives. These demonstrations will exhibit the effectiveness of an automated approach for all the steps involved with porting and tuning a legacy code application for a new architecture.

  6. Synthesizing Certified Code

    NASA Technical Reports Server (NTRS)

    Whalen, Michael; Schumann, Johann; Fischer, Bernd

    2002-01-01

    Code certification is a lightweight approach to demonstrate software quality on a formal level. Its basic idea is to require producers to provide formal proofs that their code satisfies certain quality properties. These proofs serve as certificates which can be checked independently. Since code certification uses the same underlying technology as program verification, it also requires many detailed annotations (e.g., loop invariants) to make the proofs possible. However, manually adding theses annotations to the code is time-consuming and error-prone. We address this problem by combining code certification with automatic program synthesis. We propose an approach to generate simultaneously, from a high-level specification, code and all annotations required to certify generated code. Here, we describe a certification extension of AUTOBAYES, a synthesis tool which automatically generates complex data analysis programs from compact specifications. AUTOBAYES contains sufficient high-level domain knowledge to generate detailed annotations. This allows us to use a general-purpose verification condition generator to produce a set of proof obligations in first-order logic. The obligations are then discharged using the automated theorem E-SETHEO. We demonstrate our approach by certifying operator safety for a generated iterative data classification program without manual annotation of the code.

  7. Coding Acoustic Metasurfaces.

    PubMed

    Xie, Boyang; Tang, Kun; Cheng, Hua; Liu, Zhengyou; Chen, Shuqi; Tian, Jianguo

    2017-02-01

    Coding acoustic metasurfaces can combine simple logical bits to acquire sophisticated functions in wave control. The acoustic logical bits can achieve a phase difference of exactly π and a perfect match of the amplitudes for the transmitted waves. By programming the coding sequences, acoustic metasurfaces with various functions, including creating peculiar antenna patterns and waves focusing, have been demonstrated.

  8. Computerized mega code recording.

    PubMed

    Burt, T W; Bock, H C

    1988-04-01

    A system has been developed to facilitate recording of advanced cardiac life support mega code testing scenarios. By scanning a paper "keyboard" using a bar code wand attached to a portable microcomputer, the person assigned to record the scenario can easily generate an accurate, complete, timed, and typewritten record of the given situations and the obtained responses.

  9. Pseudonoise code tracking loop

    NASA Technical Reports Server (NTRS)

    Laflame, D. T. (Inventor)

    1980-01-01

    A delay-locked loop is presented for tracking a pseudonoise (PN) reference code in an incoming communication signal. The loop is less sensitive to gain imbalances, which can otherwise introduce timing errors in the PN reference code formed by the loop.

  10. Flexible missile autopilot design studies with PC-MATLAB/386

    NASA Technical Reports Server (NTRS)

    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.

  11. Intraocular pressure following ECCE, phacoemulsification, and PC-IOL implantation.

    PubMed

    Kooner, K S; Cooksey, J C; Perry, P; Zimmerman, T J

    1988-09-01

    Abnormal intraocular pressure (IOP), either transient or permanent, may follow extracapsular cataract extraction (ECCE) with phacoemulsification (PE) and posterior chamber intraocular lens (PC-IOL) implantation. We retrospectively studied IOP measurements at different intervals post ECCE and PE in 242 eyes of 211 patients: 105 males, 106 females, 198 Caucasians and 13 blacks. Elevated IOP (greater than 23 mm Hg) was observed in 20 eyes (8.2%). Only two patients (0.8%) had persistent (greater than 3 months) IOP elevation and needed antiglaucoma therapy. Six more eyes (2.5%), however, developed glaucoma after 1 year. Hence, the incidence of secondary pseudophakic glaucoma at the conclusion of this study was 3.3%. No patient required laser or other mechanical surgery for IOP control. ECCE and PE with PC-IOL does not appear to adversely affect IOP. Patients, however, must be followed closely, as some may develop glaucoma months after surgery.

  12. Implementation of WASP-III on an IBM PC

    SciTech Connect

    Buehring, W.A.; Huber, C.C.; Hamilton, B.P.

    1985-01-01

    Argonne National Laboratory (ANL) is currently developing a microcomputer-based energy planning package entitled ENergy and Power Evaluation Program (ENPEP). As presently constructed, ENPEP consists of six analytic modules that can be run sequentially or independently: (1) macroeconomic analysis, (2) energy demand forecasting, (3) integrated energy demand/supply analysis, (4) electric load forecasting, (5) expansion planning for electrical generating systems, and (6) impacts of alternative supply systems. The Wien Automatic System Planning Package (WASP-III) is the fifth module of ENPEP and forms the heart of the ENPEP analytic capability. The experience in converting WASP-III to the IBM PC is reviewed and some recommendations for good performance on the PC are given. Finally, a few suggestions are presented for WASP improvements from the point of view of the user of the personal computer version of WASP.

  13. Magnetospheric filter effect for Pc 3 Alfven mode waves

    NASA Technical Reports Server (NTRS)

    Zhang, X.; Comfort, R. H.; Gallagher, D. L.; Green, J. L.; Musielak, Z. E.; Moore, T. E.

    1995-01-01

    We present a ray-tracing study of the propagation of Pc 3 Alfven mode waves originating at the dayside magnetopause. This study reveals interesting features of magnetospheric filter effect for these waves. Pc 3 Alfven mode waves cannot penetrate to low Earth altitudes unless the wave frequency is below approximately 30 mHz. Configurations of the dispersion curves and the refractive index show that the gyroresonance and pseudo-cutoff introduced by the heavy ion O(+) block the waves. When the O(+) concentration is removed from the plasma composition, the barriers caused by the O(+) no longer exist, and waves with much higher frequencies than 30 mHz can penetrate to low altitudes. The result that the 30 mHz or lower frequency Alfven waves can be guided to low altitudes agrees with ground-based power spectrum observation at high altitudes.

  14. Magnetospheric filter effect for Pc 3 Alfven mode waves

    NASA Technical Reports Server (NTRS)

    Zhang, X.; Comfort, R. H.; Gallagher, D. L.; Green, J. L.; Musielak, Z. E.; Moore, T. E.

    1994-01-01

    We present a ray-tracing study of the propagation of Pc 3 Alfven mode waves originating at the dayside magnetopause. This study reveals interesting features of a magnetospheric filter effect for these waves. Pc 3 Alfven mode waves cannot penetrate to low Earth altitudes unless the wave frequency is below approximately 30 mHz. Configurations of the dispersion curves and the refractive index show that the gyroresonance and pseudo-cutoff introduced by the heavy ion O(+) block the waves. When the O(+) concentration is removed from the plasma composition, the barriers caused by the O(+) no longer exist, and waves with much higher frequencies than 30 mHz can penetrate to low altitudes. The result that the 30 mHz or lower frequency Alfven waves can be guided to low altitudes agrees with ground-based power spectrum observations at high latitudes.

  15. Structure of pentaquarks Pc+ in the chiral quark model

    NASA Astrophysics Data System (ADS)

    Yang, Gang; Ping, Jialun; Wang, Fan

    2017-01-01

    The recent experimental results of the LHCb Collaboration suggested the existence of pentaquark states with a charmonium. To understand the structure of the states, a dynamical calculation of 5-quark systems with quantum numbers I JP=1/2 (1/2 )±,1/2 (3/2 )±and1/2 (5/2 )±is performed in the framework of the chiral quark model with the help of the Gaussian expansion method. The results show that there are several negative parity resonance states while all of the positive parity states are the scattering states. The Pc(4380 ) state is suggested to be the pentaquark state of Σc*D ¯. Although the energy of ΣcD ¯* is very close to the mass of Pc(4450 ), the inconsistent parity prevents the assignment. The calculated distances between quarks confirm the molecular nature of the states.

  16. Dystrophin Dp71 in PC12 cell adhesion

    PubMed Central

    Enríquez-Aragón, Jose Arturo; Cerna-Cortés, Joel; Bermúdez de León, Mario; García-Sierra, Francisco; González, Everardo; Mornet, Dominique; Cisneros, Bulmaro

    2005-01-01

    Previously, we reported that PC12 cells with decreased Dp71 expression (antisense-Dp71 cells) display deficient nerve-growth-factor-induced neurite outgrowth. In this study, we show that disturbed neurite outgrowth of antisense-Dp71 cells is accompanied by decreased adhesion activity on laminin, collagen and fibronectin. In wild-type cells, the immunostaining of Dp71 and _1-integrin overlaps in the basal area contacting the substrate, but staining of both proteins decrease in the antisense-Dp71 cells. Morphology of antisense-Dp71 cells at the electron microscopic level is characterized by the lack of filopodia, cellular projections involved in adhesion. Our findings suggest that Dp71 is required for the efficient PC12 cell attachment to b1-integrin-dependent substrata and that decreased adhesion activity of the anti-sense-Dp71 cells could determine their deficiency to extend neurites. PMID:15706226

  17. Tablet PC Enabled Body Sensor System for Rural Telehealth Applications

    PubMed Central

    Panicker, Nitha V.; Kumar, A. Sukesh

    2016-01-01

    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. PMID:26884757

  18. Practical Pocket PC Application w/Biometric Security

    NASA Technical Reports Server (NTRS)

    Logan, Julian

    2004-01-01

    I work in the Flight Software Engineering Branch, where we provide design and development of embedded real-time software applications for flight and supporting ground systems to support the NASA Aeronautics and Space Programs. In addition, this branch evaluates, develops and implements new technologies for embedded real-time systems, and maintains a laboratory for applications of embedded technology. The majority of microchips that are used in modern society have been programmed using embedded technology. These small chips can be found in microwaves, calculators, home security systems, cell phones and more. My assignment this summer entails working with an iPAQ HP 5500 Pocket PC. This top-of-the-line hand-held device is one of the first mobile PC's to introduce biometric security capabilities. Biometric security, in this case a fingerprint authentication system, is on the edge of technology as far as securing information. The benefits of fingerprint authentication are enormous. The most significant of them are that it is extremely difficult to reproduce someone else's fingerprint, and it is equally difficult to lose or forget your own fingerprint as opposed to a password or pin number. One of my goals for this summer is to integrate this technology with another Pocket PC application. The second task for the summer is to develop a simple application that provides an Astronaut EVA (Extravehicular Activity) Log Book capability. The Astronaut EVA Log Book is what an astronaut would use to report the status of field missions, crew physical health, successes, future plans, etc. My goal is to develop a user interface into which these data fields can be entered and stored. The applications that I am developing are created using eMbedded Visual C++ 4.0 with the Pocket PC 2003 Software Development Kit provided by Microsoft.

  19. The PC Dugout Micro-Mainframe Integration System: PAX Implementation

    DTIC Science & Technology

    1991-05-01

    System Mainframe Implementation Language PC Implementation Language Communications Package and File Transfer Protocol Requirements 5 DUGOUT DESIGN...remember any commands or language syntax. In some cases users are asked to answer a few simple, nontechnical prompts. To download or upload files, a...problem. The database management systems Focus and Structured Query Language /Data System (SQL/DS) successfully circumvent this restriction in the PAX VM/CMS

  20. Falling PC Solitaire Cards: An Open-Inquiry Approach

    ERIC Educational Resources Information Center

    Gonzalez-Espada, Wilson J.

    2012-01-01

    Many of us have played the PC Solitaire game that comes as standard software in many computers. Although I am not a great player, occasionally I win a game or two. The game celebrates my accomplishment by pushing the cards forward, one at a time, falling gracefully in what appears to look like a parabolic path in a drag-free environment. One day,…

  1. The photodynamic antibacterial effects of silicon phthalocyanine (Pc) 4.

    PubMed

    Dimaano, Matthew L; Rozario, Chantal; Nerandzic, Michelle M; Donskey, Curtis J; Lam, Minh; Baron, Elma D

    2015-04-08

    The emergence of antibiotic-resistant strains in facultative anaerobic Gram-positive coccal bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), is a global health issue. Typically, MRSA strains are found associated with institutions like hospitals but recent data suggest that they are becoming more prevalent in community-acquired infections. It is thought that the incidence and prevalence of bacterial infections will continue to increase as (a) more frequent use of broad-spectrum antibiotics and immunosuppressive medications; (b) increased number of invasive medical procedures; and (c) higher incidence of neutropenia and HIV infections. Therefore, more optimal treatments, such as photodynamic therapy (PDT), are warranted. PDT requires the interaction of light, a photosensitizing agent, and molecular oxygen to induce cytotoxic effects. In this study, we investigated the efficacy and characterized the mechanism of cytotoxicity induced by photodynamic therapy sensitized by silicon phthalocyanine (Pc) 4 on (a) methicillin-sensitive Staphylococcus aureus (MSSA) (ATCC 25923); (b) community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) (ATCC 43300); and (c) hospital acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) (PFGE type 300). Our data include confocal image analysis, which confirmed that Pc 4 is taken up by all S. aureus strains, and viable cell recovery assay, which showed that concentrations as low as 1.0 μM Pc 4 incubated for 3 h at 37 °C followed by light at 2.0 J/cm2 can reduce cell survival by 2-5 logs. These results are encouraging, but before PDT can be utilized as an alternative treatment for eradicating resistant strains, we must first characterize the mechanism of cell death that Pc 4-based PDT employs in eliminating these pathogens.

  2. The Photodynamic Antibacterial Effects of Silicon Phthalocyanine (Pc) 4

    PubMed Central

    Dimaano, Matthew L.; Rozario, Chantal; Nerandzic, Michelle M.; Donskey, Curtis J.; Lam, Minh; Baron, Elma D.

    2015-01-01

    The emergence of antibiotic-resistant strains in facultative anaerobic Gram-positive coccal bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), is a global health issue. Typically, MRSA strains are found associated with institutions like hospitals but recent data suggest that they are becoming more prevalent in community-acquired infections. It is thought that the incidence and prevalence of bacterial infections will continue to increase as (a) more frequent use of broad-spectrum antibiotics and immunosuppressive medications; (b) increased number of invasive medical procedures; and (c) higher incidence of neutropenia and HIV infections. Therefore, more optimal treatments, such as photodynamic therapy (PDT), are warranted. PDT requires the interaction of light, a photosensitizing agent, and molecular oxygen to induce cytotoxic effects. In this study, we investigated the efficacy and characterized the mechanism of cytotoxicity induced by photodynamic therapy sensitized by silicon phthalocyanine (Pc) 4 on (a) methicillin-sensitive Staphylococcus aureus (MSSA) (ATCC 25923); (b) community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) (ATCC 43300); and (c) hospital acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) (PFGE type 300). Our data include confocal image analysis, which confirmed that Pc 4 is taken up by all S. aureus strains, and viable cell recovery assay, which showed that concentrations as low as 1.0 μM Pc 4 incubated for 3 h at 37 °C followed by light at 2.0 J/cm2 can reduce cell survival by 2–5 logs. These results are encouraging, but before PDT can be utilized as an alternative treatment for eradicating resistant strains, we must first characterize the mechanism of cell death that Pc 4-based PDT employs in eliminating these pathogens. PMID:25856680

  3. Evolving genetic code

    PubMed Central

    OHAMA, Takeshi; INAGAKI, Yuji; BESSHO, Yoshitaka; OSAWA, Syozo

    2008-01-01

    In 1985, we reported that a bacterium, Mycoplasma capricolum, used a deviant genetic code, namely UGA, a “universal” stop codon, was read as tryptophan. This finding, together with the deviant nuclear genetic codes in not a few organisms and a number of mitochondria, shows that the genetic code is not universal, and is in a state of evolution. To account for the changes in codon meanings, we proposed the codon capture theory stating that all the code changes are non-disruptive without accompanied changes of amino acid sequences of proteins. Supporting evidence for the theory is presented in this review. A possible evolutionary process from the ancient to the present-day genetic code is also discussed. PMID:18941287

  4. Combustion chamber analysis code

    NASA Technical Reports Server (NTRS)

    Przekwas, A. J.; Lai, Y. G.; Krishnan, A.; Avva, R. K.; Giridharan, M. G.

    1993-01-01

    A three-dimensional, time dependent, Favre averaged, finite volume Navier-Stokes code has been developed to model compressible and incompressible flows (with and without chemical reactions) in liquid rocket engines. The code has a non-staggered formulation with generalized body-fitted-coordinates (BFC) capability. Higher order differencing methodologies such as MUSCL and Osher-Chakravarthy schemes are available. Turbulent flows can be modeled using any of the five turbulent models present in the code. A two-phase, two-liquid, Lagrangian spray model has been incorporated into the code. Chemical equilibrium and finite rate reaction models are available to model chemically reacting flows. The discrete ordinate method is used to model effects of thermal radiation. The code has been validated extensively against benchmark experimental data and has been applied to model flows in several propulsion system components of the SSME and the STME.

  5. LACEwING: A New Moving Group Analysis Code

    NASA Astrophysics Data System (ADS)

    Riedel, Adric R.; Blunt, Sarah C.; Lambrides, Erini L.; Rice, Emily L.; Cruz, Kelle L.; Faherty, Jacqueline K.

    2017-03-01

    We present a new nearby young moving group (NYMG) kinematic membership analysis code, LocAting Constituent mEmbers In Nearby Groups (LACEwING), a new Catalog of Suspected Nearby Young Stars, a new list of bona fide members of moving groups, and a kinematic traceback code. LACEwING is a convergence-style algorithm with carefully vetted membership statistics based on a large numerical simulation of the Solar Neighborhood. Given spatial and kinematic information on stars, LACEwING calculates membership probabilities in 13 NYMGs and three open clusters within 100 pc. In addition to describing the inputs, methods, and products of the code, we provide comparisons of LACEwING to other popular kinematic moving group membership identification codes. As a proof of concept, we use LACEwING to reconsider the membership of 930 stellar systems in the Solar Neighborhood (within 100 pc) that have reported measurable lithium equivalent widths. We quantify the evidence in support of a population of young stars not attached to any NYMGs, which is a possible sign of new as-yet-undiscovered groups or of a field population of young stars.

  6. Kinetics of alpha-PcCu --> beta-PcCu isothermal conversion in air and thermal behavior of beta-PcCu from in situ real-time laboratory parallel-beam X-ray powder diffraction.

    PubMed

    Ballirano, Paolo; Caminiti, Ruggero

    2009-07-09

    The kinetics of the alpha-PcCu --> beta-PcCu conversion in air has been followed, under isothermal conditions, in situ real-time in the 423-443 K temperature range. Data have been fitted following the JMAK model. The reaction order of the kinetics at 423 K is consistent with a diffusion controlled, deceleratory nucleation rate process for 2D laminar particles, whereas at higher temperatures it is consistent with a phase boundary controlled, deceleratory nucleation rate process for 2D laminar particles. At 423 K, the overall transformation mechanism implies three steps: growth of the alpha-PcCu phase, disordering of adjacent columns of molecules of phthalocyanine, and nucleation and growth of the beta-PcCu phase. The calculated empirical activation energy is of 187 kJ/mol significantly greater than that for the alpha-PcCo --> beta-PcCo conversion. This fact seems to support the reported different structures of alpha-PcCo and alpha-PcCu. Investigation of the thermal behavior of beta-PcCu indicates a strongly anisotropic thermal expansion that follows the alpha(c) > alpha(a) approximately = alpha(b) trend. Moreover, the beta angle decreases with increasing temperature. Such anisotropy is consistent with the geometry of the very weak N3...H3 hydrogen bond which acts mainly along the c axis.

  7. Design and research of retrofitting PC boiler into CFB boiler

    SciTech Connect

    Chen, H.P.; Lu, J.D.; Huang, L.; Liu, H.; Lin, Z.; Liu, D.C.

    1997-12-31

    In China, there are a large number of aged pulverized coal (PC) boilers at aging utility power plants. Many of them are beyond their reasonable working life or in a condition of unreliable operation, low combustion efficiency, and serious air pollution. It is very important and urgent to retrofit the aged PC boilers, and repower the aging utility power plants in China. Circulating fluidized bed (CFB) boilers have been developed rapidly, and paid great attention to in China. There are many striking advantages to retrofit an aged boiler with a CFB boiler. The retrofitting is suitable to meet the needs of effective utilization of low-grade coal, reducing SO{sub 2} and NO{sub x} emissions and repowering an aging power plant. The cost is much lower than that of building a new CFB unit. The National Laboratory of Coal Combustion (NLCC) has always paid great attention to studying and developing CFB combustion technology in connection with Chinese national conditions, and has evolved distinguishing technology features of its own. This paper introduces a new design concept of retrofitting PC boiler into Pi ({Pi}-shaped) CFB boiler with downward exhaust cyclone, and relevant research work and results of design and calculation.

  8. Electronic transitions and band offsets in C60:SubPc and C60:MgPc on MoO3 studied by modulated surface photovoltage spectroscopy

    NASA Astrophysics Data System (ADS)

    Fengler, S.; Dittrich, Th.; Rusu, M.

    2015-07-01

    Electronic transitions at interfaces between MoO3 layers and organic layers of C60, SubPc, MgPc, and nano-composite layers of SubPc:C60 and MgPc:C60 have been studied by modulated surface photovoltage (SPV) spectroscopy. For all systems, time dependent and modulated SPV signals pointed to dissociation of excitons at the MoO3/organic layer interfaces with a separation of holes towards MoO3. The highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gaps (EHL) of C60, SubPc, and MgPc and the effective EHL of SubPc:C60 and MgPc:C60 were measured. The offsets between the LUMO (ΔEL) or HOMO (ΔEH) bands were obtained with high precision and amounted to 0.33 or 0.73 eV for SubPc:C60, respectively, and to -0.33 or 0.67 eV for MgPc:C60, respectively. Exponential tails below EHL and most pronounced sub-bandgap transitions were characterized and ascribed to disorder and transitions from HOMO bands to unoccupied defect states.

  9. Stimulation at Desert Peak -modeling with the coupled THM code FEHM

    SciTech Connect

    kelkar, sharad

    2013-04-30

    Numerical modeling of the 2011 shear stimulation at the Desert Peak well 27-15. This submission contains the FEHM executable code for a 64-bit PC Windows-7 machine, and the input and output files for the results presented in the included paper from ARMA-213 meeting.

  10. pRNAm-PC: Predicting N(6)-methyladenosine sites in RNA sequences via physical-chemical properties.

    PubMed

    Liu, Zi; Xiao, Xuan; Yu, Dong-Jun; Jia, Jianhua; Qiu, Wang-Ren; Chou, Kuo-Chen

    2016-03-15

    Just like PTM or PTLM (post-translational modification) in proteins, PTCM (post-transcriptional modification) in RNA plays very important roles in biological processes. Occurring at adenine (A) with the genetic code motif (GAC), N(6)-methyldenosine (m(6)A) is one of the most common and abundant PTCMs in RNA found in viruses and most eukaryotes. Given an uncharacterized RNA sequence containing many GAC motifs, which of them can be methylated, and which cannot? It is important for both basic research and drug development to address this problem. Particularly with the avalanche of RNA sequences generated in the postgenomic age, it is highly demanded to develop computational methods for timely identifying the N(6)-methyldenosine sites in RNA. Here we propose a new predictor called pRNAm-PC, in which RNA sequence samples are expressed by a novel mode of pseudo dinucleotide composition (PseDNC) whose components were derived from a physical-chemical matrix via a series of auto-covariance and cross covariance transformations. It was observed via a rigorous jackknife test that, in comparison with the existing predictor for the same purpose, pRNAm-PC achieved remarkably higher success rates in both overall accuracy and stability, indicating that the new predictor will become a useful high-throughput tool for identifying methylation sites in RNA, and that the novel approach can also be used to study many other RNA-related problems and conduct genome analysis. A user-friendly Web server for pRNAm-PC has been established at http://www.jci-bioinfo.cn/pRNAm-PC, by which users can easily get their desired results without needing to go through the mathematical details.

  11. Orpinomyces cellulase celf protein and coding sequences

    DOEpatents

    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.

  12. Static and Dynamic Energetic Disorders in the C60, PC61BM, C70, and PC71BM Fullerenes.

    PubMed

    Tummala, Naga Rajesh; Zheng, Zilong; Aziz, Saadullah G; Coropceanu, Veaceslav; Brédas, Jean-Luc

    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.

  13. Pyramid image codes

    NASA Technical Reports Server (NTRS)

    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.

  14. Report number codes

    SciTech Connect

    Nelson, R.N.

    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.

  15. Embedded foveation image coding.

    PubMed

    Wang, Z; Bovik, A C

    2001-01-01

    The human visual system (HVS) is highly space-variant in sampling, coding, processing, and understanding. The spatial resolution of the HVS is highest around the point of fixation (foveation point) and decreases rapidly with increasing eccentricity. By taking advantage of this fact, it is possible to remove considerable high-frequency information redundancy from the peripheral regions and still reconstruct a perceptually good quality image. Great success has been obtained previously by a class of embedded wavelet image coding algorithms, such as the embedded zerotree wavelet (EZW) and the set partitioning in hierarchical trees (SPIHT) algorithms. Embedded wavelet coding not only provides very good compression performance, but also has the property that the bitstream can be truncated at any point and still be decoded to recreate a reasonably good quality image. In this paper, we propose an embedded foveation image coding (EFIC) algorithm, which orders the encoded bitstream to optimize foveated visual quality at arbitrary bit-rates. A foveation-based image quality metric, namely, foveated wavelet image quality index (FWQI), plays an important role in the EFIC system. We also developed a modified SPIHT algorithm to improve the coding efficiency. Experiments show that EFIC integrates foveation filtering with foveated image coding and demonstrates very good coding performance and scalability in terms of foveated image quality measurement.

  16. An overview of the evaluation plan for PC/MISI: PC-based Multiple Information System Interface

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Lim, Bee Lee; Hall, Philip P.

    1985-01-01

    An initial evaluation plan for the personal computer multiple information system interface (PC/MISI) project is discussed. The document is intend to be used as a blueprint for the evaluation of this system. Each objective of the design project is discussed along with the evaluation parameters and methodology to be used in the evaluation of the implementation's achievement of those objectives. The potential of the system for research activities related to more general aspects of information retrieval is also discussed.

  17. Is the Metallic Phosphorus Carbide (β0-PC) Monolayer Stable? An Answer from a Theoretical Perspective.

    PubMed

    Rajbanshi, Biplab; Sarkar, Pranab

    2017-02-16

    Phosphorus carbide (PC) has been the subject of major research efforts in recent years. In this regard, very recently, a stoichiometric metallic phosphorus carbide (β0-PC) monolayer has been proposed as locally stable with one lone nonbonding electron in each C atom. Therefore, the ambiguity of coexistence of a nonbonding electron with metallic properties for β0-PC is reported and hence deserves further explanation. Herein, using first-principles calculations, we have explored the stability and electronic properties of β0-PC to resolve this ambiguity. The metallic behavior of β0-PC is explained on the basis of electron delocalization involving P and C atoms along a zigzag chain of β0-PC. We have also explored the possibility of getting a β0-PC monolayer via homogeneous doping of C (P) into phosphorene (graphene) and layer exfoliation of 3D bulk PC with β-InS-like structure, which has been experimentally synthesized.

  18. Characterization of μ-oxo-(BsubPc)2 in Multiple Organic Photovoltaic Device Architectures: Comparing against and Combining with Cl-BsubPc.

    PubMed

    Castrucci, Jeffrey S; Garner, Richard K; Dang, Jeremy D; Thibau, Emmanuel; Lu, Zheng-Hong; Bender, Timothy P

    2016-09-21

    We demonstrate the first application of a unique boron subphthalocyanine (BsubPc) derivative, the oxygen bridged dimer μ-oxo-(BsubPc)2, as a multifunctional material within planar heterojunction organic photovoltaic (OPV) devices. We first explored the pairing of μ-oxo-(BsubPc)2 with well-known electron accepting and electron donating materials to explore its basic functionality. These preliminary device structures and metrics indicated that μ-oxo-(BsubPc)2 is best applied as an electron donating material when used in simple bilayer structures, as it yielded comparable OPV device efficiencies to that of the more well-established and highly optimized chloro-boron subphthalocyanine (Cl-BsubPc) OPV device structures. Thereafter we established that the HOMO/LUMO energy levels of μ-oxo-(BsubPc)2 are well-placed to apply it as a bifunctional donor/acceptor interlayer material in both energy and charge cascade OPV device architectures. Within this context, we found that μ-oxo-(BsubPc)2 was particularly effective in a charge cascade device as an interlayer between Cl-BsubPc and C70. We finally found evidence of an alloying-like effect for devices with mixed electron donor layers of (Cl-BsubPc) and μ-oxo-(BsubPc)2, achieved through co-deposition. The overarching conclusion is therefore that μ-oxo-(BsubPc)2 has the ability to improve the performance of Cl-BsubPc OPV devices and is a multifunctional material worthy of further study.

  19. The USL NASA PC R and D project: General specifications of objectives

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor)

    1984-01-01

    Given here are the general specifications of the objectives of the University of Southwestern Louisiana Data Base Management System (USL/DBMS) NASA PC R and D Project, a project initiated to address future R and D issues related to PC-based processing environments acquired pursuant to the NASA contract work; namely, the IBM PC/XT systems.

  20. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cutaneous carbon dioxide (PcCO2) monitor. 868.2480... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a noninvasive...

  1. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cutaneous carbon dioxide (PcCO2) monitor. 868.2480... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a noninvasive...

  2. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO 2) monitor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cutaneous carbon dioxide (PcCO 2) monitor. 868... SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO 2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a...

  3. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cutaneous carbon dioxide (PcCO2) monitor. 868.2480... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a noninvasive...

  4. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO 2) monitor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cutaneous carbon dioxide (PcCO 2) monitor. 868... SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO 2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a...

  5. 21 CFR 868.2500 - Cutaneous oxygen (PcO2) monitor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cutaneous oxygen (PcO2) monitor. 868.2500 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2500 Cutaneous oxygen (PcO2) monitor. (a) Identification. A cutaneous oxygen (PcO2) monitor is a noninvasive, heated sensor (e.g.,...

  6. 21 CFR 868.2500 - Cutaneous oxygen (PcO 2) monitor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cutaneous oxygen (PcO 2) monitor. 868.2500 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2500 Cutaneous oxygen (PcO 2) monitor. (a) Identification. A cutaneous oxygen (PcO2) monitor is a noninvasive, heated sensor (e.g.,...

  7. 21 CFR 868.2500 - Cutaneous oxygen (PcO2) monitor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cutaneous oxygen (PcO2) monitor. 868.2500 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2500 Cutaneous oxygen (PcO2) monitor. (a) Identification. A cutaneous oxygen (PcO2) monitor is a noninvasive, heated sensor (e.g.,...

  8. 21 CFR 868.2500 - Cutaneous oxygen (PcO 2) monitor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cutaneous oxygen (PcO 2) monitor. 868.2500 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2500 Cutaneous oxygen (PcO 2) monitor. (a) Identification. A cutaneous oxygen (PcO2) monitor is a noninvasive, heated sensor (e.g.,...

  9. 21 CFR 868.2500 - Cutaneous oxygen (PcO2) monitor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cutaneous oxygen (PcO2) monitor. 868.2500 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2500 Cutaneous oxygen (PcO2) monitor. (a) Identification. A cutaneous oxygen (PcO2) monitor is a noninvasive, heated sensor (e.g.,...

  10. Code Disentanglement: Initial Plan

    SciTech Connect

    Wohlbier, John Greaton; Kelley, Timothy M.; Rockefeller, Gabriel M.; Calef, Matthew Thomas

    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.

  11. Compressible Astrophysics Simulation Code

    SciTech Connect

    Howell, L.; Singer, M.

    2007-07-18

    This is an astrophysics simulation code involving a radiation diffusion module developed at LLNL coupled to compressible hydrodynamics and adaptive mesh infrastructure developed at LBNL. One intended application is to neutrino diffusion in core collapse supernovae.

  12. Activated T cells exhibit increased uptake of silicon phthalocyanine Pc 4 and increased susceptibility to Pc 4-photodynamic therapy-mediated cell death.

    PubMed

    Soler, David C; Ohtola, Jennifer; Sugiyama, Hideaki; Rodriguez, Myriam E; Han, Ling; Oleinick, Nancy L; Lam, Minh; Baron, Elma D; Cooper, Kevin D; McCormick, Thomas S

    2016-06-08

    Photodynamic therapy (PDT) is an emerging treatment for malignant and inflammatory dermal disorders. Photoirradiation of the silicon phthalocyanine (Pc) 4 photosensitizer with red light generates singlet oxygen and other reactive oxygen species to induce cell death. We previously reported that Pc 4-PDT elicited cell death in lymphoid-derived (Jurkat) and epithelial-derived (A431) cell lines in vitro, and furthermore that Jurkat cells were more sensitive than A431 cells to treatment. In this study, we examined the effectiveness of Pc 4-PDT on primary human CD3(+) T cells in vitro. Fluorometric analyses of lysed T cells confirmed the dose-dependent uptake of Pc 4 in non-stimulated and stimulated T cells. Flow cytometric analyses measuring annexin V and propidium iodide (PI) demonstrated a dose-dependent increase of T cell apoptosis (6.6-59.9%) at Pc 4 doses ranging from 0-300 nM. Following T cell stimulation through the T cell receptor using a combination of anti-CD3 and anti-CD28 antibodies, activated T cells exhibited increased susceptibility to Pc 4-PDT-induced apoptosis (10.6-81.2%) as determined by Pc 4 fluorescence in each cell, in both non-stimulated and stimulated T cells, Pc 4 uptake increased with Pc 4 dose up to 300 nM as assessed by flow cytometry. The mean fluorescence intensity (MFI) of Pc 4 uptake measured in stimulated T cells was significantly increased over the uptake of resting T cells at each dose of Pc 4 tested (50, 100, 150 and 300 nM, p < 0.001 between 50 and 150 nM, n = 8). Treg uptake was diminished relative to other T cells. Cutaneous T cell lymphoma (CTCL) T cells appeared to take up somewhat more Pc 4 than normal resting T cells at 100 and 150 nm Pc 4. Confocal imaging revealed that Pc 4 localized in cytoplasmic organelles, with approximately half of the Pc 4 co-localized with mitochondria in T cells. Thus, Pc 4-PDT exerts an enhanced apoptotic effect on activated CD3(+) T cells that may be exploited in targeting T cell-mediated skin

  13. Comparison of CAP88 PC Ver. 3.0 and MAXDOSE dose assessment models involving co-located stack releases at the Savannah River site.

    PubMed

    Farfán, Eduardo; Jannik, G Timothy; Lee, Patricia; Powell, Aaron

    2013-08-01

    The Savannah River National Laboratory's Environmental Dosimetry Group performs dosimetry assessments for Savannah River Site (SRS) radionuclide air emissions utilizing the Clean Air Act Assessment Package-1988 (CAP88) code (CAP88 PC Ver. 3.0) and the MAXDOSE-SR Ver. 2011 code, which is an SRS-specific version of the Nuclear Regulatory Commission's MAXIGASP code. CAP88 PC and MAXDOSE-SR are used at SRS for demonstrating compliance with Environmental Protection Agency dose standards for radionuclide emissions to the atmosphere and Department of Energy Order 458.1 dose standards, respectively. During a routine comparison of these two assessment models, it was discovered that CAP88 PC Ver. 3.0 was not producing the expected results when using multiple co-located stacks in a single run. Specifically, if the stack heights are considered separately, the results for several radionuclides (but not all) differ from the combined run [i.e., 1 + 2 does not equal (1+2)]. Additionally, when two or more stack heights are considered in a run, the results depend on the order of the selected stack heights. For example, for a two stack-height run of 0 meter and 61 m input produces different results from a 61 m and 0 m input run. This study presents a comparison of CAP88 PC Ver. 3.0 and MAXDOSE-SR Ver. 2011 based on SRS input data and on two-stack release scenarios. The selected radionuclides for this study included gases/vapors (H, C, Kr, and I) and particulates (Sr, Cs, Pu, and Am) commonly encountered at SRS.

  14. Seals Flow Code Development

    NASA Technical Reports Server (NTRS)

    1991-01-01

    In recognition of a deficiency in the current modeling capability for seals, an effort was established by NASA to develop verified computational fluid dynamic concepts, codes, and analyses for seals. The objectives were to develop advanced concepts for the design and analysis of seals, to effectively disseminate the information to potential users by way of annual workshops, and to provide experimental verification for the models and codes under a wide range of operating conditions.

  15. Interactive computer code for dynamic and soil structure interaction analysis

    SciTech Connect

    Mulliken, J.S.

    1995-12-01

    A new interactive computer code is presented in this paper for dynamic and soil-structure interaction (SSI) analyses. The computer program FETA (Finite Element Transient Analysis) is a self contained interactive graphics environment for IBM-PC`s that is used for the development of structural and soil models as well as post-processing dynamic analysis output. Full 3-D isometric views of the soil-structure system, animation of displacements, frequency and time domain responses at nodes, and response spectra are all graphically available simply by pointing and clicking with a mouse. FETA`s finite element solver performs 2-D and 3-D frequency and time domain soil-structure interaction analyses. The solver can be directly accessed from the graphical interface on a PC, or run on a number of other computer platforms.

  16. Robust Nonlinear Neural Codes

    NASA Astrophysics Data System (ADS)

    Yang, Qianli; Pitkow, Xaq

    2015-03-01

    Most interesting natural sensory stimuli are encoded in the brain in a form that can only be decoded nonlinearly. But despite being a core function of the brain, nonlinear population codes are rarely studied and poorly understood. Interestingly, the few existing models of nonlinear codes are inconsistent with known architectural features of the brain. In particular, these codes have information content that scales with the size of the cortical population, even if that violates the data processing inequality by exceeding the amount of information entering the sensory system. Here we provide a valid theory of nonlinear population codes by generalizing recent work on information-limiting correlations in linear population codes. Although these generalized, nonlinear information-limiting correlations bound the performance of any decoder, they also make decoding more robust to suboptimal computation, allowing many suboptimal decoders to achieve nearly the same efficiency as an optimal decoder. Although these correlations are extremely difficult to measure directly, particularly for nonlinear codes, we provide a simple, practical test by which one can use choice-related activity in small populations of neurons to determine whether decoding is suboptimal or optimal and limited by correlated noise. We conclude by describing an example computation in the vestibular system where this theory applies. QY and XP was supported by a grant from the McNair foundation.

  17. Ionospheric signatures of cusp latitude Pc 3 pulsations

    SciTech Connect

    Engebretson, M.J.; Anderson, B.J. ); Cahill, L.J. Jr. ); Arnoldy, R.L. ); Rosenberg, T.J. ); Carpenter, D.L. ); Gail, W.B. ); Eather, R.H. )

    1990-03-01

    The authors have compared search coil magnetometer, riometer, photometer, and ELF-VLF receiver data obtained at South Pole Station and McMurdo, Antarctica, during selected days in March and April 1986. Narrow-band magnetic pulsations in the Pc 3 period range are observed simultaneously at both stations in the dayside sector during times of low interplanetary magnetic field (IMF) cone angle, but are considerably stronger at South Pole, which is located at a latitude near the nominal foot point of the daysie cusp/cleft region. Pulsations in auroral light a 427.8 nm wavelength are often observed with magnetic pulsations at South Pole, but such optical pulsations are not observed at McMurdo. When Pc 3 pulsations are present, they exhibit nearly identical frequencies, proportional to the magnitude of the IMF, in magnetometer, photometer, and ELF-VLF receiver signals at South Pole Station and in magnetometer signals at McMurdo. Singals from the 30-MHz riometer at South Pole are modulated in concert with the magnetic and optical variations during periods of broadband pulsation activity, but no riometer variations are noted during periods of narrow-band activity. Because riometers are sensitive to electrons of auroral energies (several keV and above), while the 427.8-nm photometer is sensitive to precipitation with much lower energies, they interpret these observatons as showing that precipitating magnetosheathlike electrons (with energies {le} 1 keV) at nominal dayside cleft latitudes are at times modulated with frequencies similar to those of upstream waves. They suggest that these particles may play an important role, via modification of ionospheric currents and conductivities, in the transmission of upstream wave signals into the magnetosphere and in the generation of dayside high-latitude Pc 3 pulsations.

  18. A versatile, PC-based gamma ray monitor.

    PubMed

    Drndarevic, V; Jevtic, N

    2008-01-01

    This paper describes a new computer-based gamma ray monitor for laboratory and field measurements. The monitor consists of a universal peripheral device, and GM counter gamma ray probe, connected via USB to the PC. The peripheral device is generic; in addition to the GM probe, it accepts sensors for spectrometric measurements as well as sensors for the measurement of other environmental parameters. Owing to its low-power consumption, it is used with laptop or palmtop computer, as a portable field measurement instrument. The proposed solution has advantages over conventional instrument: (1) open architecture; (2) user-defined functions and (3) easy network connection.

  19. Wf/pc Cycle 2 Calib: Measles Monitor

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1991-07-01

    This program takes "uniform illuminated" pictures of the earth to monitor the measles effect observed in WFPC observations. The goals of this program are: 1. Look for changes in measle numbers/characteristics 2. Have before/after images in place for decontaminations. This program will also build up a high quality flat field. The observations are done only with PC with a frequency of once every two weeks. The sequence (during a single earth occultation) is: F517N+OPEN, F517N+F122M, F517N+OPEN

  20. Wf/pc Cycle 1 CALIB:RECIPROCITY Monitor

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    1990-12-01

    This program takes "uniform illuminated" pictures of the earth to monitor the "reciprocity" effect observed in earth calib observations. The goals of this program are: 1. Watch for discrete changes in this behavior 2. Look for long term variability 3. Have before/after checks in place for decontaminations safings, or UVflood. This program will also build up a high quality flat field. The observations are done only with PC with a frequency of once every week. The sequence (during a single earth occultation) is: F517N+OPEN, F517N+F122M, F517N+OPEN